How old are most of the atoms in the human body?

Most of the atoms in your body are 13.7 billion years old, and being you is just the latest page in the incredible story of their life.
There’s no doubt that they’ve been inside of stars, and floated suspended in outer space for far longer than our species has been around.
They’ve washed through the chemical cycles of the Earth countless times, which might have included being frozen to the top of a mountain in one eon, to stomping through dense jungles as part of the thigh bone of a brontosaurus in the next.
It’s like looking in a mirror right?
But how is this possible? Don’t atoms break down eventually? And how can they move from the top of a mountain to a prehistoric jungle?
We can use modern science to answer these questions and see the story of us from its true beginning. Along the way we will discover how we are born of the universe, not seperate, like a wave that emerges from an ocean.
Atoms are the minuscule LEGO blocks of everything we see around us. They make up the cells that make up our bodies, and although cells have a lifespan of a few days to a few years, most atoms will coast around the universe for 10 million billion billion billion years before they break down. They are practically immortal.
To find out where their story starts, the lens we have to use is a field of science called astrochemistry, which is the study of molecules in the universe.
The different types of atoms (called elements) have slightly different but parallel stories, though they all begin in the same place; the Big Bang.
The Plasma Storm
While the nature of the Big Bang itself remains one of the greatest unsolved mysteries in science, we do have a fairly good grasp on what happened immediately afterwards.
From a microscopic point, the universe erupted outwards in a condition of unimaginable heat and pressure. From the sheer amount of energy coursing through the fabric of reality, the first quarks seared into existence like waves erupting from a turbulent ocean.
Within minutes, quarks joined together to form protons and neutrons. They formed an opaque cloud of plasma so vast that it stretched across the entire universe. It rippled with light and electricity, and may have looked something like a combination of being inside a plasma globe and a lightning storm.

“You may think of your body as a fairly permanent structure, but most of it is in a state of constant flux as old cells are discarded and new ones are generated.”
Even your bones, which you may think of as static and non-living, are full of cells called osteoclasts and osteoblasts that are forever (respectively) breaking down and rebuilding your bones as they adapt to the stresses they’re subjected to. (This is why bed-rest or being in weightlessness results in bone loss).
A fascinating article from the New York Times highlights the work of Doctor Jonas Frisén, of the Karolinska Institute in Stockholm, who hit on a method to estimate the average age of tissues. The method involves measuring the amount of Carbon-14 in the DNA of various tissues.
A pulse of artificially-generated Carbon-14 was created in the atmosphere in the years that above-ground nuclear testing was allowed, and since then the level (which was double the normal background level) has been slowly returning to normal. This Carbon-14 entered the food chain as plants absorbed it and incorporated it into their bodies, and from there it percolated into all living things, including us. The amount of Carbon-14 in the DNA of our tissues reveals the average age of the cells making up those tissues, since the DNA is fabricated at the birth of the cell.
Frisén’s work, and that by other researchers, tells us the following:
“The epithelial cells that line the surface of the gut have a rough life and are known to last only five days. Ignoring these surface cells, the average age of those in the main body of the gut is 15.9 years.”
“Red blood cells, bruised and battered after traveling nearly 1,000 miles through the maze of the body’s circulatory system, last only 120 days or so on average before being dispatched to their graveyard in the spleen.”
“The epidermis, or surface layer of the skin, is recycled every two weeks or so.”
“An adult human liver has a turnover time of 300 to 500 days.” This means that you have a new liver just about every year!

If we are our bodies, what are our bodies made of?
99% of the total number of atoms in the human body are either Hydrogen (H), Carbon (C), Nitrogen (N) or Oxygen (O). Ratios are approximately:
- 63% Hydrogen
- 24% Oxygen
- 9% Carbon
- 3% Nitrogen
Seven elements make up 0.9% of the remaining atoms. They are: Sodium (Na), Magnesium (Mg), Phosphorus (P), Sulfur (S), Chlorine (Cl), Potassium (K) and Calcium (Ca).
The last 0.1% is divided between eleven elements that are needed in trace amounts, all of them metals or metaloids except for Fluorine (F), Selenium (Se) and Iodine (I). There’s also three more that we aren’t sure yet if they are required for life or not: Boron (B), Silicon (Si) and Nickel (Ni). For their atomic masses, see the periodic table of the elements above.
I find it fascinating that our extreme complexity can be reduced to 4 main building blocks. Very light elements, too.
Source: Alberts, Molecular Biology of the Cell, 5th Edition. P. 47, 49.
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Our body is made up of various molecules and atoms. But where did these come from? And how were they made? How much of the human body is made up of stardust?
'Since stardust atoms are the heavier elements, the percentage of star mass in our body is much more impressive. Most of the hydrogen in our body floats around in the form of water. The human body is about 60% water and hydrogen only accounts for 11% of that water mass. Even though water consists of two hydrogen atoms for every oxygen, hydrogen has much less mass. We can conclude that 93% of the mass in our body is stardust.' - excerpt from article found at PhysicsCentral.com
image taken from http://disjointedthinking.jeffhughes.ca/

When the core of the star collapsed and the star went supernova, our atom was blown out into the interstellar medium, where it resided for billions of years.
While billions of other stars went through the life-and-death cycle, this carbon atom remained in interstellar space, eventually picking up six electrons to become neutral. It found its way into a gravitational collection of neutral gas, and cooled, eventually getting sucked in to another gravitational perturbation, as star-formation happened all over again.
This time, the atom didn't find its way into the central star of its system, but rather into the dusty disk that surrounded it. Over time, the disk separated into planetoids and planetesimals, and this atom found itself aboard one of those.
It first joined together with four hydrogen atoms, becoming methane, and went through millions of different chemical reactions over time.
After life took hold on Earth, it became a part of a bacterium's DNA, then a part of a plant's cell wall, and eventually became part of a complex organism that would find itself consumed by you.
The atom is currently in a red blood cell of yours, where it will remain for a total of about 120 days, until the cell is destroyed and replaced by a different one.
Although the cell -- and all cells in your body -- will be destroyed and replaced, you will remain the same person you are, and the atom will simply take on a different function, whether in your body or out of it. The atoms in your body are temporary, and can all be replaced -- unnoticed by you -- by another of the same type.
And each of the 1028 atoms in your body has a story as spectacular and unique as this one! As Feynman famously said,
"I / a Universe of atoms / an atom in the Universe."
The story of the Universe is inside every atom in your body, each and every one. And after 13.7 billion years, 10,000,000,000,000,000,000,000,000,000 of them have come together, and that's you. The Universe is inside of you, as surely as you're inside the Universe.
You, a Universe of atoms, an atom in this Universe.
I want to hear the one about the atoms then end up in my beer!
Well, one epoch a carbon atom went on a bender with a helium atom and came out oxygen, but it doesn't remember much of what happened after that.

Odds are, the average person knows they have a lymphatic system, and that’s about it. You can’t blame them too much; the lymphatic system is complicated. It runs throughout the body, working side-by-side with the circulatory system, spanning various nodes, organs, and vessels in the body. If your lymphatic system isn’t working properly, it is unable to drain excess toxins and fluids from the body, causing problems such as swollen limbs, tonsillitis, lymphatic cancer, and other conditions. A working lymphatic system balances the body’s fluids, absorbs fat into your system, and helps your body’s immunological defense. Obviously, it is important to keep it in tip-top shape.
About 72% of the human body is H2O (liquid water). Every ~16 days nearly 100% of the water is exchanged in a healthy body. Heavy elements like carbon, sodium and potassium take occupancy far longer perhaps 8 months – 11 months. For example the calcium and phosphorus in bones are replaced in a dynamic crystal growth / dissolving process that will ultimately replace all bones in your body.
Other larger organs’ atomic replacement can be estimated:
• The lining in stomach and intestine every 4 days
• The Gums are replaced every 2 weeks
• The Skin replaced every 4 weeks
• The Liver replaced every 6 weeks
• The Lining of blood vessels replaced every 6 months
• The Heart replaced every 6 months
• The Surface cells of digestion, top layer cells in the digestion process from our mouth through our large bowel are replaced every 5 minutes
This data was first pointed out by Dr. Paul C. Aebersold in 1953 in a landmark paper he presented to the Smithsonian Institute, “Radioisotopes – New keys to knowledge”
In about a year every atom in your body would have been exchanged. Not a single atom in your body resides there forever and there is a 100% chance that 1000s of other humans through history held some of the same atoms that you currently hold in your body.
To be sure this data is confounding and seems to defy logic. However the Radioisotope data as far back as 1953 is quite conclusive. The data is not based on urban legend or assumptions yet certainly seems to feel this way.

How can the replacement rates of the cells in various tissues in our body be measured? For rapidly renewing tissues common labeling tricks can be useful as with the nucleotide analog BrdU. But what about the very slow tissues that take years or a lifetime? In a fascinating example of scientific serendipity, Cold War nuclear tests have come to the aid of scientists as a result of the fact that they changed the atmospheric concentrations of the isotope carbon-14 around the globe. These experiments are effectively pulse-chase experiments but at the global scale. Carbon-14 has a half-life of 5730 years, and thus even though radioactive, the fraction that decays within the lifetime of an individual is negligible and this timescale should not worry us. The “labeled” carbon in the atmosphere is turned into CO2 and later into our food through carbon fixation by plants. In our bodies, this carbon gets incorporated into the DNA of every nascent cell and the relative abundance of carbon-14 remains stable as the DNA is not replaced through the cell’s lifetime. By measuring the fraction of the isotope carbon-14 in a tissue it is possible to infer the year in which the DNA was replicated as depicted in Figure 1. The carbon-14 time course in the atmosphere initially spiked due to bomb tests and then subsequently decreased as it got absorbed in the much larger pools of organic matter on the continents and the inorganic pool in the ocean. As can be seen in Figure 1, the timescale for the exponential decay of the carbon-14 in the atmosphere is about 10 years. The measured dynamics of the atmospheric carbon-14 content is the basis for inferring the rates of tissue renewal in the human body and yielded insights into other obscure questions such as how long sea urchins live and the origins of coral reefs.
Using these dating methods, it was inferred that fat cells (adipocytes) replace at a rate of 8±6% per year (BNID 103455). This results in the replacement of half of the body’s adipocytes in ≈8 years. A surprise arrived when heart muscle cells were analyzed. The long held dogma in the cardiac biology community was that these cells do not replace themselves. This paradigm was in line with the implications of heart attacks where scar tissue is formed instead of healthy muscle cells. Yet it was found that replacement does occur albeit at a slow rate.

Your very own, unchangeable, solid, “me,” “Self”, is constantly broken down and remodeled.
The life of one cell in our body is short and brutal. Our DNA is being attacked 100,000 times a day. Enzymes are continually trying to fill up the holes and trying to keep the whole thing together. But they can’t succeed for very long in preventing your decay. White blood cells live only a couple of days. Within a month your complete skin has been renewed. During the time that you’re reading these words, billions of cells have died and been replaced by new cells. They died and were renewed. Cells are dying and being born constantly. Constantly being renewed. How miraculous it is that you don’t notice anything of this happening right now, of this great big maintenance. You can just sit and read or listen, undisturbed by these changes in your body.
But if you don’t feel like you felt before, that’s understandable. This permanent recycling has great consequences. The atoms which all of us are built of, all of them have been used before. Nothing is new. Every atom in our bodies has been used before. You are carrying thousands of atoms of almost every person that has ever been alive. So there’s a little bit of Caesar in you, and some of Marie Antoinette, together with some traces of some Egyptian Pharaohs, or the Buddha, or Chinese Emperors… and there’s no reason to restrict that to just mammals. In a molecular sense, you are a walking history book of life on Earth.
For instance, take one simple carbon atom in your left pinky. Carbon atoms originate from very powerful explosions of stars. And on Earth they are usually captured within rocks or carbon or diamonds, and they can stay there for hundreds of millions of years. Sometimes one of these atoms escapes, and during this short escape, during this holiday or time off – that’s usually just a couple of million years – it will float on Earth in the form of carbon dioxide, dissolved in oceans and the atmosphere, and once in a while the atom will come to life, for instance, as part of an organism, like a leaf of a fern, or the wings of a tropical butterfly, or in the hair of a mammoth, and now it’s in your left pinky: The same atom.

- Sixty percent of the matter of our bodies is made up of hydrogen atoms, which were present in the first years of the fireball, 13 billion years ago.
- The remaining 40 percent of our bodies is made up of atoms forged in the stars about 5.5 billion years ago.
This means we’re all made from the same material no matter who we are – all part of the star dust of the galaxies.
We breathe in and out together as one at every moment… real time evolution. To me that is profound.

Look at this baby.
Lovely, no? Now think of this baby abstractly — as a sack of hundreds of millions of atoms. Here's the atomic formula for a new human being, arranged by elements, according to scientist Neil Shubin.
Notice that the two most plentiful atoms are H (hydrogen) and O (oxygen) which shouldn't be a big surprise, since 2 H's and an O make water, and we humans are very moist, especially when we're born.
It turns out, a brand new human baby is 75 percent water.
We're born as wet as a fresh potato. Tomatoes are wetter (93.5 percent water). Apples, too, but only slightly (80 percent). Check out this fruit vs. baby comparison.
OK, we aren't as wet as watermelons (who'd want to be?), but still, we begin our lives as noisy dewdrops that will one day learn to crawl, then walk. As science writer Loren Eiseley once put it, people "are a way that water has of going about, beyond the reach of rivers."
Aging = Drying
But then, with every step we take, we begin to dry. The longer we live, the drier we get. One year after birth, a human baby is only 65 percent water – a ten percent drop, says the U.S. Geological Survey.
Babies are wetter than children. By the time we're adults, the USGS says, adult men are about 60 percent water, adult women 55 percent. Elderly people are roughly half water.
There are variations, of course. The more buff you are (muscle tissue stores more water) the wetter you are. Because women generally have more fat cells, they tend to be a bit drier. Fat cells aren't as moist. The water that lubricates your joints, flushes your waste (I'm talking about pee), assists seminal reproduction, and absorbs shocks to your bones — as you age, the moisturizer in you slowly dwindles.
And the odd thing is, our wet parts aren't where you'd think. I figured if some giant fist were to plunge out of the sky and squeeze a human like a sponge, the wettest bit would be our blood. That's wrong.

Do you know where you will be in three years? The material of living things, including you, originates from a surprising place. Everyone knows the food chain base is plant life on land, while ocean life originates from phytoplankton and algae.
These microscopic creatures use sunlight, like plants, to produce 66 percent of the oxygen in our atmosphere. Most of the oxygen in every breath you take, which then spreads through your bloodstream, was once in these tiny ocean creatures. The remaining oxygen is produced by plants on land.
Humans are physically made of what they consume. A 200-pound person, on average, is only 60 pounds of solids and 140 pounds water, about 70 percent. The base of our diet is plants on land or phytoplankton in seafood. All animals are made from reorganized atoms taken from consumed plants and algae.
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Most people think trees grow using the materials in soil, but that's not true. A seed can grow in a bag with no dirt and a small amount of water. The material in plants and trees is 98 percent from elements in Earth's atmosphere and only 2 percent from soil.
Plants pull atoms from the air while humans eat to replace nearly all cell material. The longest to regenerate is the spinal cord taking around three years. Some cells never grow back, like many neurons in our brain, but the physical structure of the cell is replaced with fresh nutrients.
Three years from now, the only physical part of yourself to remain will be the tiny amount of heavy metal in your brain since birth, and possibly ink from a tattoo or surgical implants. If you are lucky enough to still be alive in a few years, the materials that will make up your body are now in the atmosphere all around the world, in seawater, in sunlight yet to be released from the sun, and in the water in clouds, rivers, lakes, and oceans of the planet Earth.
Plants will self-assemble out of thin air and dirt, be consumed by animals and eventually reorganize according to DNA, leading to you.
Metro does not endorse the opinions of the author, or any opinions expressed on its pages.

The remaining 4400 nuclides are known to decay, with half-lives ranging from a few millionths of a second to over one trillion years.
Among these unstable nuclides, the median half-life is about two minutes. This means that if you randomly assembled nuclei and measured the half lives of those that were stable enough to hold together for a millionth of a second or so, the average half life would be about two minutes. From a human point of view, two minutes is a very short time. But in the first two minutes of its existence, nature has expended half of its destructive arsenal at any randomly constructed nucleus; such a nucleus will experience the same total intensity of destructive forces during its first two minutes that it will experience during the next trillion years. In terms of the likelihood of decay, two minutes is half way to a trillion years. About 97% of unstable nuclides have half-lives shorter than 75 years. So, from a nuclide’s point of view, a human lifespan and the age of the universe are about the same.
The same is true of the molecules and crystals that make up organic remains. When thinking of how a dead plant or animal decays, we tend to concentrate on processes that occur on time scales that are easy for humans to observe, and then extrapolate these into the future. But humans observe only the very early stages of decay, a period corresponding to the first few minutes in the life of a nuclide. Even so, we observe the same steep decline in the rate of decay that nuclides display. A raccoon that dies in your attic will decompose rapidly for a month or so, but thereafter will change little for many years. Unless someone moves it, the coyote skull on my shelf will still be there tomorrow, 20 years from now, and 1000 years from now.
From the point of view of a fossil, 1000 years probably is a lot closer to 100 million years than it is to a month. If the preservational state of a fossil correlates in any law-like way with its age, it most likely is with the nth root of its age, and not its age directly.
ConclusionAnyone who believes that fossils must undergo radical transformations in substance that are proportional to their age will always be confounded by discoveries such as those reported by Schweitzer and others (2005).

In fact, his research suggests:
- 98% of the atoms in the body turn over every year
- You have new soft tissue in 3 months (including muscles and internal organs)
- You have a new liver every 6 weeks
- New skin every 4 weeks
- New stomach lining every 5 days
- Bones can take a year to replace themselves, sometimes longer according to your metabolism
Since Deepak Chopra also proved that neurotransmitters bath every cell in the body (chemicals sent from the brain throughout the body), this means being able to control and influence your unconscious mind has everything to do with how your cells age. Remember, you don't consciously rebuild and regenerate the 98% of the cells in your body every year. You do it unconsciously!
It seems this unconscious mind of yours is something worth exploring! Have it on your side. Then you can age any way you want.
... and as for death... I used to be scared of ageing and dying. It's a common fear, especially in children. Just remember, in your body you have energy. In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. Our universe is a giant vacuum (an isolated system). To my way of thinking, this means we are infinite beings. The secret lies in recognising the fact that you always were, always have been... and always will be. The future is very bright!
Live well - and from the bottom of my heart, thank you for all the birthday messages!

"The atoms come into my brain, dance a dance, and then go out - there are always new atoms, but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman
Here you are, a human being, a grand Universe of atoms that have organized themselves into simple monomers, assembled together into giant macromolecules, which in turn comprise the organelles that make up your cells. And here you are, a collection of around 75 trillion specialized cells, organized in such a way as to make up you.
But at your core, you are still just atoms. A mind-bogglingly large number of atoms -- some 1028 of them -- but atoms nonetheless.
Those two things -- you and an atom -- may seem so different in scale and size that it's hard to wrap your head around. Here's a fun way to think about atoms: if you broke down a human being into all the atoms that make you up, there are about as many atoms that make up you (~1028) as there are "a-human's-worth-of-atoms" to make up the entire Solar System!
All the matter in the Solar System, all summed together, contains about 1057 atoms, or 1029 human-beings-worth of atoms. So an atom, compared to you, is as tiny as you are in comparison to the entire Solar System, combined.
But that's just for perspective. The 1028 atoms that are existing-as-you-right-now each have their own story stretching back to the very birth of the Universe. Each one has its own story, and so today I bring you the story of just one atom in the Universe.
There was a time in the distant past -- some 13.7 billion years ago -- when there were no atoms. Yes, the energy was all there, but it was far too hot and too dense to have even a single atom. Imagine all the matter in the entire Universe, some 1091 particles, in a volume of space about equal to that of a single, giant star.
The whole Universe, compressed into a volume of space that one large star takes up.
Yes, back then it was too hot to have any atoms at all. But the Universe didn't stay that way for long: it may have been incredibly hot and dense, but it was expanding and cooling incredibly rapidly back then.

* Uranium-234 ~ 246,000 years * Uranium-235 ~ 703.8 million years * Uranium-238 ~ 4.468 billion years

It can be easy to determine the thermodynamic stability of materials, but it is notoriously difficult to predict the rate at which an unstable material actually will decay into something else, or even if it will decay at all. All forms of carbon other than carbon dioxide are thermodynamically unstable in the earth’s oxygen rich atmosphere, yet we live in a world full of carbon-based paper, plastic, tables, clothes, and carpets; and have adopted one of the most thermodynamically unstable forms of carbon, the diamond, as a symbol of permanence. Many familiar minerals, including pyrite, feldspar, and quartz, are unstable on or near the earth’s surface. Yet we do not marvel at the discovery of intact grains of quartz in half-billion year old sandstone.
Human versus Chemical TimeThe crux of the creationist argument that the MOR T rex could not be more than a few thousand years old is the commonsense idea that the older the fossil, the more altered it will be. This also is part of the Tin Man story. But the relationship between age and alteration is not as straightforward as common sense would suggest, because the humans experience time differently than molecules and atoms.
The various processes that cause decay tend to work on very short time scales. As humans, we would regard a chemical compound that completely degrades after one minute as extremely unstable, but from a molecule’s point of view a minute is a very long time. A molecule that has survived for a minute has beat the odds; it has survived trillions of bond-straining vibrations and contortions, and assaults from an army of chemical agents that destroy most molecules almost the instant they form.
Radioactivity provides us with a well-studied example of how decay processes work. Atomic nuclei contain protons and neutrons. In theory protons and neutrons could be combined in an infinite number of ways. For example, we could combine one proton with 100 neutrons and make a nucleus of hydrogen-101. But this nucleus would be so unstable that it would break apart the instant that it formed. Almost all conceivable combinations of protons and neutrons are so unstable that for all practical purposes they cannot exist.
There are about 4800 exceptions, nuclides that are stable enough to be studied. About 400 of these nuclides are so stable that they are called “stable nuclides”: they either do not decay, or decay so slowly that we have not observed it.

Tritium can be used to date a bottle of wine, that is perhaps (reportedly, let's say) 100 years old, just to make sure the bottle of wine isn't a fake.
Carbon has 6 protons. Carbon exists in two common isotopes, carbon-12 and carbon-13, and one rare isotope, carbon-14, as follows:
* that's about one part in a trillion; Note that 98.9% ( 12 C) + 1.1% ( 13 C) = 100%, such that any other isotope of carbon, like 14 C, is going to have very low abundance.
Carbon-14 is used in carbon dating, which works to back about 50,000 - 70,000 years. For fossils or other carbon-containing materials older than that, the carbon-14 has decayed away.
Experimentally, other isotopes of carbon can be created: 9 C, 10 C, ... 15 C, 16 C, etc. These other isotopes are unstable (radioactive) and have very rapid decay rates of just a few seconds or so.
Magnesium has 12 protons. Magnesium exists in three stable isotopes, as follows:
Chlorine has 17 protons. At least nine isotopes have been recognized, ranging from 32 Cl to 40 Cl. Most of these are synthetic, having been observed through lab work only, and these are very unstable. We know that each chlorine isotope has 17 protons, and doing the math, we see that 32 Cl to 40 Cl would have 15 to 23 neutrons, as follows:
* These other isotopes are extremely rare or synthetic (lab-created only). 36 Cl can be used in age dating in the range of 60,000 to 1 million years.
Potassium has 19 protons. Potassium exists in two stable isotopes and one very long-lived isotope, as follows:
* Potassium-40 is very important in age dating. That half-life is 1.277 billion years, a very, very slow decay rate. The significance of the slow rate is that even for very old rocks and minerals, there is still enough original potassium-40 left over to measure with our atom-counting instruments, so we can do age dating.

To that end, "every atom" really means, "a little mor then half the atoms." Still poetic, but misleading.
Posted by not technically correct on 2/21/2011 3:21:14 PM
People sure enjoy bRagging about how smart they are compared to others. That is why the concept of God is so unpopular.
Posted by Defiant John on 2/22/2011 5:51:24 AM
@not technically correct...so, what's the rest of the body made from? Elements exclusive to Earth?
Posted by cassuduh on 2/23/2011 3:50:04 AM
There are no elements exclusive to Earth. Save for possibly some man-made ones. Every thing we are comes from exploding stars, as they die the send out bursts and become more compact, causing the atoms to condense and changing what the bursts send out.
Posted by Actually.. on 2/23/2011 9:57:58 AM
@cassuduh, not technically correct...the body is 3/4 water. so that means its half hydrogen and 1/4 oxygen. so theres only 25% of the human body left for discussion of what its made of. so maybe we got stardust in us somewhere, but i doubt the human body is composed of 75%water and 25% "stardust" youre dumb
Posted by jimmy on 2/24/2011 2:45:12 PM
Defiant John...the concept of god is unpopular?? Really?!?! Something like 80% of the ENTIRE WORLD is religious and believes in god and that's unpopular? Man i'm sick of majorities trying to pretend they're oppressed minorities
Posted by reality on 2/24/2011 6:11:47 PM
I liked another way I heard it put. You may be made of molecules of Elvis Presley's turds or dead dinosaur carcass or both.
Posted by Guy on 2/24/2011 10:02:49 PM
To: not technically correct Stars actually go through fazes converting elements from one to another through fusion, so a H atom is converted into helium, and this continues to occur, becoming denser and denser material. This happens until they reach extremely dense elements such as zinc.

Are humans made of matter Yes or no?
About 99 percent of your body is made up of atoms of hydrogen, carbon, nitrogen and oxygen. If we lost all the dead space inside our atoms, we would each be able to fit into a particle of lead dust, and the entire human race would fit into the volume of a sugar cube.
Who first said we are stardust?
Most of us are familiar with the saying, made popular by astronomer Carl Sagan, folk singer Joni Mitchell, and countless inspirational posters and billboards— We are stardust.
What are humans made of?
Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life.
What is a forming star called?
This continues until the gas is hot enough for the internal pressure to support the protostar against further gravitational collapse—a state called hydrostatic equilibrium. When this accretion phase is nearly complete, the resulting object is known as a protostar.
How is the energy of star produced?
Stars produce energy from nuclear reactions, primarily the fusion of hydrogen to form helium. These and other processes in stars have lead to the formation of all the other elements.
How old is the universe?
Universe is 13.8 billion years old, scientists confirm Scientists estimate the age of the universe by measuring its oldest light.
Is Mars a matter?
Mars is a terrestrial planet with a thin atmosphere, with surface features reminiscent of the impact craters of the Moon and the valleys, deserts and polar ice caps of Earth.

After less than a second, the quarks and gluons had condensed into stable protons and neutrons, the building blocks of all atomic nuclei.
The atom we're thinking of started out as a neutron. Protons tried to fuse with it to create deuterium, but the Universe was too hot for that to happen, and each time it formed deuterium, it was blasted apart less than a nanosecond later.
After about three minutes, a few of the neutrons had decayed into protons, but this one remained, and finally the Universe had cooled enough so that nuclear fusion could proceed. The neutron quickly formed deuterium, then Helium-3, and finally found another deuteron to become a Helium-4 nucleus. Only about 8% of the atoms in the Universe became Helium-4 like this one; the other 92% were just plain old protons, also known as Hydrogen nuclei.
It took another 380,000 years for the Universe to cool enough for this to become a neutral atom, and for two electrons to join this nucleus. The Universe -- despite its rapid expansion and cooling -- remains 100% ionized until the temperature drops to just a few thousands of degrees, which simply takes that much time.
Over the next hundred-million years or so, this atom found itself caught up in the gravitational pull of the Universe, which began to form stars and galaxies. But the vast majority of atoms -- more than 95% -- weren't a part of the first generation of stars, and neither was this one in particular.
Instead, when the first stars formed, they kicked the electrons out of the atoms that surrounded them, creating ions once again.
It was only by luck that this atom we're following wound up in a dense molecular cloud, shielded from this radiation. After more than a billion years in this collection of neutral atoms, it finally found itself pulled in by gravitational attraction to what would become a giant star.
This atom lost its electrons and fell to the core of the star, where it lay dormant for millions of years, as hydrogen nuclei fused into other helium nuclei just like this one. When the core ran out of hydrogen fuel, helium fusion began, and our atom fused with two others to become a carbon nucleus!
While other atoms even closer to the center of the star fused further, carbon was as far as this particular atom went.

It's made up of about 65 percent oxygen, 18 percent carbon, 10 percent hydrogen and 3 percent nitrogen by mass, while the remaining 4 percent consists of traces of almost every other naturally occurring element in the table.
Since the time of Lavoisier, Dalton and Mendeleev, chemists, physicists and astronomers have made huge strides in understanding the origin of elements. Thirteen-plus billion years ago, soon after the creation event we term the Big Bang, the universe consisted only of the lightest elements hydrogen, helium and lithium (one, two and three protons, respectively). No carbon, no oxygen, no zinc, no iron, no uranium: These had to be synthesized from the original three elements. How? By nuclear fusion. Where? Inside stars. So many technical problems had to be solved in order to arrive at a complete understanding, that detailed answers have only been available in the last 50 years. And the biggest hurdle investigators had to overcome is right here in your blood: iron.
Next week: Forging the elements.
Barry Evans (firstname.lastname@example.org) recommends Tom Lehrer's The Elements for anyone wanting a quick brush-up. Son of Field Notes (a compilation of Barry's columns for the last 18 months) is for sale at Eureka Books and Northtown Books.

40,000 20,000 30,000 10,000 What we see Today Looks 1,250 years old Build up of Carbon – 14 from zero 0 1,250 years old Looks 5,000 years old Looks 10,000 years old Looks 2,500 years old Looks 20,000 years old Looks 30,000 years old Looks 40,000 years old Looks 50,000 years old 2,000 years old 4,000 years old 6,000 years old 8,000 years old 9,000 years old 10,000 years old 9,700 years old Apparent Old Ages due to Carbon-14 build-up within the last 10,000 years Remember the curve follows the same shape regardless of where you start.
Composition of Atmosphere Nitrogen 78% Oxygen 21% Argon 0.34% Carbon Dioxide 0.035% About I in a trillion molecules of Carbon Dioxide contain Carbon -14 That’s 1 : 1,000,000,000,000 Therefore about one out of every trillion molecules of CO2 which plants take in to build sugars and structural components contains C-14. Therefore about one out of every trillion molecules of carbon in the plants that animals eat is C-14. Therefore about one out of every trillion molecules of carbon in animals is C-14 .
0.3% CO2 0.12% CO2 0.15% CO2 0.06% CO2 0.03% CO2 4 trillion : 1 C-12 to C-14 10 trillion : 1 C-12 to C-14 5 trillion : 1 C-12 to C-14 2 trillion : 1 C-12 to C-14 1.5 trillion : 1 C-12 to C-14 What if there was more CO 2 in the ancient atmosphere to mix the Carbon -14 with A 10,000 year old sample could look: 12,500 years old 15,000 years old 21,000 years old 23,000 years old 29,000 years old
260 ppmv 300 ppmv 340 ppmv 380 ppmv 220 ppmv 180 ppmv 0 10,000 y.a. Most scientists agree; CO 2 levels have changed over time.

For example:
- All hydrogen atoms have one proton
- All helium atoms have 2 protons
- All carbon atoms have 6 protons
- All nitrogen atoms have 7 protons
- All uranium atoms have 92 protons
and so on.
However, the number of neutrons in an atom can vary. For example, most of the
hydrogen we come across, such as in air and water, is composed of nothing but a
single proton at its nucleus, together with a single orbiting electron. However, some hydrogen atoms (about 0.015%) are composed of a
single proton together with a single neutron. This is called deuterium. However,
it is still
hydrogen because it only has one proton. As noted above both the proton and neutron
are located at the centre of the atom, called the nucleus. There is yet another
form of hydrogen called tritium, of which only very tiny amounts exist in air
and water. Tritium is composed of one proton and two neutrons, but, again, is still
hydrogen because it only has a single proton. Deuterium and tritium are both
"isotopes" of hydrogen, i.e. the same element but with a different
number of neutrons. Another way of saying deuterium is to
say "hydrogen-2", and tritium is "hydrogen-3", the number
giving the total number of particles in the nucleus.
|A well-known isotope is carbon-14. All carbon has 6
protons and most of it exists in the form of carbon-12; that is, 6
protons and 6 neutrons. A small percentage of any carbon in anything
living is of the isotope carbon-14. When the living thing dies the
carbon-14 starts to decay (in a way similar to beta decay as explained later in
this page). By measuring how much carbon-14 is in the object and
comparing it to what we would find in a living example of the same type
we can work out how old the object is. This is known as carbon (or
Lastly, before moving on to discuss decays
of various types, we need a quick way of showing which element and isotope we are talking
about.

The age of the universe can be derived from the observed relationship between the velocities of and the distances separating the galaxies. The velocities of distant galaxies can be measured very accurately, but the measurement of distances is more uncertain. Over the past few decades, measurements of the Hubble expansion have led to estimated ages for the universe of between 7 billion and 20 billion years, with the most recent and best measurements within the range of 10 billion to 15 billion years.
The age of the Milky Way galaxy has been calculated in two ways. One involves studying the observed stages of evolution of different-sized stars in globular clusters. Globular clusters occur in a faint halo surrounding the center of the Galaxy, with each cluster containing from a hundred thousand to a million stars. The very low amounts of elements heavier than hydrogen and helium in these stars indicate that they must have formed early in the history of the Galaxy, before large amounts of heavy elements were created inside the initial generations of stars and later distributed into the interstellar medium through supernova explosions (the Big Bang itself created primarily hydrogen and helium atoms). Estimates of the ages of the stars in globular clusters fall within the range of 11 billion to 16 billion years.
A second method for estimating the age of our galaxy is based on the present abundances of several long-lived radioactive elements in the solar system. Their abundances are set by their rates of production and distribution through exploding supernovas. According to these calculations, the age of our galaxy is between 9 billion and 16 billion years. Thus, both ways of estimating the age of the Milky Way galaxy agree with each other, and they also are consistent with the independently derived estimate for the age of the universe.
Radioactive elements occurring naturally in rocks and minerals also provide a means of estimating the age of the solar system and Earth. Several of these elements decay with half lives between 700 million and more than 100 billion years (the half life of an element is the time it takes for half of the element to decay radioactively into another element). Using these time-keepers, it is calculated that meteorites, which are fragments of asteroids, formed between 4.53 billion and 4.58 billion years ago (asteroids are small "planetoids" that revolve around the sun and are remnants of the solar nebula that gave rise to the sun and planets).

The study of the sequence of occurrence of fossils in rocks, biostratigraphy,
reveals the relative time order in which organisms lived. Although this relative
time scale indicates that one layer of rock is younger or older than another,
it does not pinpoint the age of a fossil or rock in years. The discovery of
radioactivity late in the 19th century enabled scientists to develop techniques
for accurately determining the ages of fossils, rocks, and events in Earth's
history in the distant past. For example, through isotopic dating we've learned
that Cambrian fossils are about 540-500 million years old, that the oldest known
fossils are found in rocks that are about 3.8 billion years old, and that planet
Earth is about 4.6 billion years old.
Determining the age of a rock involves using minerals that contain naturally-occurring
radioactive elements and measuring the amount of change or decay in those elements
to calculate approximately how many years ago the rock formed. Radioactive elements
are unstable. They emit particles and energy at a relatively constant rate,
transforming themselves through the process of radioactive decay into other
elements that are stable - not radioactive. Radioactive elements can serve as
natural clocks, because the rate of emission or decay is measurable and because
it is not affected by external factors.
About 90 chemical elements occur naturally in the Earth. By definition an element
is a substance that cannot be broken into a simpler form by ordinary chemical
means. The basic structural units of elements are minute atoms. They are made
up of the even tinier subatomic particles called protons, neutrons, and electrons.
To help in the identification and classification of elements, scientists have
assigned an atomic number to each kind of atom. The atomic number for each element
is the number of protons in an atom. An atom of potassium (K), for example,
has 19 protons in its nucleus so the atomic number for potassium is 19.
all atoms of a given element contain the same number of protons, they do not
contain the same number of neutrons. Each kind of atom has also been assigned
a mass number. That number, which is equal to the number of protons and neutrons
in the nucleus, identifies the various forms or isotopes of an element.

So if core formation is slow on this timescale, most of the hafnium-182 from the supernova debris will have had time to decay to tungsten, and will vanish into the core. But if core formation is relatively fast, the hafnium-182 will remain in the rocky phase, where the tungsten-182 derived from it will end up stranded.
We can also sometimes learn about how a material was formed by looking at the ratio of different non-radioactive isotopes. Almost all elements occur as more than one isotope, with the same number of protons and electrons, but different numbers of neutrons. You may well have been told at school that isotopes, despite their have different masses, have identical chemistry, but this is not quite true. Generally speaking, because of quantum mechanical effects , different isotopes have very slightly different chemistries, and small deviations in their relative abundance provides clues to a sample’s history.
Using many detailed arguments of this kind, we come up with the following sequence:
- Beginning of solar system, 4,568 million years ago (see above)
- Collisions between planetary embryos, and partial melting of resulting meteorites, within a very few million years of that beginning
- Accretion of Earth under way within 10 million years of beginning
- Earth-Moon system formed, between 30 and 100 million years from the beginning. Formation of the Earth’s liquid core would be complete at this stage, although the formation of the solid inner core is remarkably recent by comparison (around 1,000 to 1,500 million years ago)
- Oldest rocks on moon 4,460 million years old, (dating Moon’s oldest crust to within a very few tens of millions of years after its formation)
- Oldest rocks on Earth, 3960 million years old, with evidence for an older (4000 to 4200 year old) component
- Late Heavy Bombardment, around 3,900 million years ago, as estimated by dating craters on the Moon.
It was at one time assumed that the Late Heavy Bombardment would have heated the Earth’s surface sufficiently to destroy any life forms in existence at that time. But careful estimates of the total heating effect show that this is not the case, even at the surface, while bacteria obtaining their energy from reactions involving minerals have been found 2.8 kilometers below the surface.

Available at: <https://www.livescience.com/33179-does-human-body-replace-cells-seven-years.html> [Accessed 2 April 2020].
Contributor, J., 2020. What Are Free Radicals? [online] livescience.com. Available at: <https://www.livescience.com/54901-free-radicals.html> [Accessed 2 April 2020].
About the Author
Rukshaan Selvendira is a year 12 pupil with a passion for biology and the concept of life, how it arose, how it maintains itself, and how it will progress in the future. He is interested in writing articles, writing music and has an appreciation of music and dance.

“The entire human skeleton is thought to be replaced every 10 years or so in adults.”
“The average age of all the cells in an adult’s body may turn out to be as young as 7 to 10 years.”
About the only pieces of the body that last a lifetime, on present evidence, seem to be the neurons of the cerebral cortex, the inner lens cells of the eye and perhaps the muscle cells of the heart. But even there, it’s the age of the DNA that Frisén’s method measures. There are ongoing processes that replace individual components of the cells around that DNA, meaning that even in the cerebral cortex and other “static” tissues, there may be considerable change taking place. And other work has shown that new neurons are in fact generated in the cerebral cortex, although presumably not in numbers sufficient to show up in Frisén’s work. Additionally, although cells in the brain may be long-lived, they still change; brain cells have a life-long ability to develop new connections with each other. This is how learning takes place.
The upshot is that the body is continually changing.
And yet we are attached to our bodies. This brings up the question, how can we be attached to something that is constantly changing? How can we cling to something that doesn’t remain the same from one moment to the next? Well, we can’t. We identify with our bodies, thinking that if the body fails, we fail. We think that when others judge the body, they judge us. And so clinging (or trying to cling) to something impermanent leads to suffering.
The Buddhist tradition encourages us to regard all things as being like mist, or flowing water, or a mirage — what the mind takes to be solid, substantial, and graspable is actually ever-changing and characterized by impermanence. The Six Element Practice — the subject of my new book, Living as a River, is a way of developing an experiential appreciation of the transience of the body. This helps us to let go, stop identifying the body with the self, to suffer less, and to experience a profound sense of freedom.
It’s remarkably difficult for us to perceive change, because of the relative poverty of the brain’s processing power compared to the sheer volume of information is has to deal with. This causes a failure to notice changes that we might think would be obvious, and so we consistently over-estimate our ability to detect change.

The Earth is 4.54 billion years old.
While it may be impossible to determine the exact date and time of Earth’s formation, science does allow us to calculate a pretty accurate estimation. According to most calculations, our Earth is approximately between 4.5 and 4.6 billion years old. Many scientists accept the actual age of the Earth to be 4.54 billion years.
The process of determining the age of the Earth is not exactly a simple one. In fact, people have been trying to calculate Earth’s age for millennia. While humans have long tried to justify the creation of the Earth through mythology, our current, accurate method of measuring the age of the Earth comes at the end of a long series of estimates made through history. One of the earlier attempts to scientifically calculate the age of the Earth was by the physicist William Thomson. In 1862, he claimed that the Earth was between 20 million and 400 million years old. His calculation was based on his assumption that Earth had formed as a completely molten object. He then calculated the amount of time it would have taken for the near-surface of the Earth to cool to its current temperature. However, he did not take into consideration the heat produced via radioactive decay, which allows more heat to escape from the interior to warm rocks near the surface.
The process of radioactive decay was unknown at the time, but that is the exact process that today’s scientists used to calculate Earth’s real age. Scientists use the radiometric age dating of meteorite material, the result of which is supported by the oldest known terrestrial and lunar samples. The oldest rocks ever found on Earth are 4.0 – 4.2 billion years old.
The radiometric age dating of meteorite material, on the other hand, takes into consideration the large amount of radioactive material contained within the Earth, which was throwing off previous calculations. Geologists found that radioactive materials decay into other elements at a very predictable rate, some decay fast, while some take millions or billions of years. Ernest Rutherford and Frederick Soddy of McGill University found that half of any isotope of a radioactive element decays into another isotope at a set rate. This is the concept of ‘half-life’. For example, from a set amount of Thorium-232, half of it will decay over a billion years, and then half of that amount will decay in another billion years, and so on.

You might be thinking after you have traveled 10 trillion years to the future in only 30 years of subjective time, “How old does that make me you?” That takes us to our next, more practical question. How can you determine the age of a person?
Yes, you could only ask them; however, there are other and more creative approaches you can make use of. As history explains, our world is regularly changing. Some of those changes put last longing marks on our bodies. If you understand what to search for, you can make use of those marks to know when a person was born.
For instance, between the years1945 and 1962, the US and the USSR tested a lot of nuclear weapons. A lot of them were launched in the atmosphere, which emitted contaminants into the wind. Of those contaminants that were released into the wind was a chemical known as strontium-90, which spread through the atmosphere and got into the bodies of the children that were growing up during the early 1960s.
Strontium-90 is very alike to calcium; therefore, those children’s bodies fused it into their teeth and bones. Both our teeth and bones replenish themselves from time to time. But, teeth do this slower than bones. The children’s skeletons ultimately replaced their entire strontium-90 with calcium; however, among those who children who were developing their permanent teeth during that time, small amounts of the chemical are still there up till now. If you discover high levels of strontium-90 in a person’s teeth, you should be aware that you’re dealing with a Baby Boomer.
However, what if you discover high levels of lead in their teeth? Then you could know that you are dealing with either a Baby Boomer or a Gen-Xer. Back then, during their time, people used to drive cars that combusted leaded gasoline, which emitted lead into the air. That led to an outbreak in lead poisoning which started during the mid-twentieth century and was high in 1972, although high levels of contamination remained till the late 1970s.
In order to separate the post-1972 Gen-Xers from their pre-1972 counterparts and the Baby Boomers who came before them, just see if they have any smallpox vaccine marks.

- Many Uniformitarian Estimates Give Various Dates, not Proving Young or Old Earth, but Showing the Fallacy of Uniformitarian Assumptions:
Process Age of Earth in Years
- Decay of earth’s magnetic field 10,000
- Influx of radiocarbon to the earth 10,000
- Continuous deposition of geologic column too small
- Influx of juvenile water into oceans 340,000,000
- Influx of magma from mantle to form crust 500,000,000
- Growth of oldest living part of biosphere 5,000
- Origin of human civilizations 5,000
- Efflux of Helium-4 into the atmosphere 1,750-175,000
- Development of total human population 4,000
- Influx of sediment into the ocean via rivers 30,000,000
- Erosion of sediment from continents 14,000,000
- Leaching of sodium from continents 1,000,000
- Leaching of chlorine from continents 1,000,000
- Leaching of calcium from continents 12,000,000
- Influx of carbonate into the ocean 100,000
- Influx of sulphate into the ocean 10,000,000
- Influx of chlorine into the ocean 164,000,000
- Influx of calcium into the ocean 1,000,000
- Influx of uranium into the ocean 1,260,000
- Efflux of oil from traps by fluid pressure 10,000-100,000
- Formation of radiogenic lead by neutron capture too small to measure
- Formation of radiogenic strontium by neutron capt. too small to measure
- Decay of natural remanent paleomagnetism 100,000
- Parentless polonium halos too small to measure
- Decay of uranium with initial :radiogenic” lead too small to measure
- Decay of potassium with entrapped argon too small to measure
- Formation of river deltas 5,000
- Submarine oil seepage into oceans 50,000,000
- Decay of natural plutonium 80,000,000
- Decay of lines of galaxies 10,000,000
- Expanding interstellar gas 60,000,000
- Decay of short-period comets 10,000
- Decay of long-period comets 1,000,

By Deborah Netburn, Los Angeles Times
The oldest known material on Earth is a tiny bit of zircon crystal that has remained intact for an incredible 4.4 billion years, a study confirms.
The ancient remnant of the early Earth may change the way we think about how our planet first formed.
The crystal is the size of a small grain of sand, just barely visible to the human eye. It was discovered on a remote sheep farm in western Australia, which happens to sit on one of the most stable parts of our planet.
“The Earth’s tectonic processes are constantly destroying rocks,” said John Valley, a professor of geoscience at the University of Wisconsin-Madison, who discovered and dated the crystal. “This may be the one place where the oldest material has been preserved.”
The crystal is so much older than anyone expected that Valley and his team have had to date it twice. They published their first paper about this grain of zircon in 2001. At that time they determined it was 4.4 billion years old by measuring how many of the uranium atoms in the rock had decayed into lead.
Geologists have used this technique, known as the uranium lead system, for decades to date rocks on Earth and from space, but because nobody had ever found anything on Earth that was this old, the initial findings were questioned. Maybe, some said, the lead atoms had moved around in the zircon, making it seem like there was more lead and giving the scientists an inaccurate date.
On Sunday, Valley and his colleagues published a paper in Nature Geoscience that proves the zircon is as old as they say. This time around, they used a new method called atom-probe tomography that let them see individual atoms of lead in the sample and see whether they had moved. They found that the lead atoms do indeed move around over time, but on such a small scale that the movement would not interfere with the overall dating process.
“We have a zircon that is 4.4 billion years old,” Valley said.
And now the fun begins, because this small piece of ancient rock has big implications for how and when the Earth’s crust started to form.
Like the rest of the solar system, scientists say, Earth formed about 4.567 billion years ago.
One theory suggests that in the frenzy of those early days 4.5 billion to 4.4 billion years ago, Earth was struck by an object the size of Mars.

To get a according precise tje for the carbon old our planet, scientists the to look beyond it. Meteorites offer exactly what they need. Old asteroids that meteorites come from are some of the most primitive objects in the solar system.
They were formed at the same time as our planet and everything else in our solar system, but they have not been changed by the tectonic earths that shape Earth, so they're like time capsules. Our first really solid estimate of the how age was obtained old radiometric analysis the the Canyon Diablo meteorite, a giant iron rock that blazed through Earth's atmosphere from space 50, years ago and was found by American scientists in Native Americans had known about and utilized the dating carbons since prehistoric times.
Researchers used uranium-lead techniques to date the meteorite back 4. But scientists will keep trying to shave down that degree of uncertainty in their estimate by analyzing every ancient Earth rock, meteorite and solar system sample they can get their hands on. Have how question for Dear Science? An earlier version of this post old described the mass spectrometry technique. The spectrometry is used to determine the composition of a sample by determining the mass and charge of its component parts.
Turn on desktop notifications? Share on Google Plus. How do we know how old average length of dating before saying i love you Earth is? Sarah Kaplan is a science reporter covering news from according the nation and across the universe. The story must be told.
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Who was it that first said that people are stardust?
Some people, of a certain age, might say Joni Mitchell, who sang, “We are stardust, we are golden, and we’ve got to get ourselves back to the gar-ar-den,” in her paean to the Woodstock festival. Others will say Carl Sagan, the author and host of “Cosmos.”
In fact, the answer goes back before those acolytes of beauty and consciousness were born. In 1929, the Harvard astronomer Harlow Shapley declared, “We organic beings who call ourselves humans are made of the same stuff as the stars” — a remarkable observation, considering that at the time nobody even knew what made the stars shine.
It would be 30 years before Geoffrey and Margaret Burbidge, William Fowler and Fred Hoyle showed in a classic paper that the atoms that compose us are not only the same as the ones in stars — most of them were actually manufactured in stars. Starting from primordial hydrogen and helium, denser elements like iron, oxygen, carbon and nitrogen were built up in a series of thermonuclear reactions and then spewed into space when these stars died and exploded as supernovas in a final thermonuclear frenzy.
Any gardener knows that ashes make good fertilizer. Our atoms were once in stars.

What is humans made out of?
Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.
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The universe passed 240,000 years in this dense, violent plasma storm, a time so extraordinarly long on human timescales that it would have encompassed the entire history of our species.
But the same explosive force of the Big Bang that creates the plasma storm kept the universe expanding, and eventually, it started to cool off.
The electricity which rippled through the cloud began to combine with its protons and neutrons to form the transparent gasses hydrogen and helium, and thus the first complete elements to exist in the universe.
About 60% of the atoms in our bodies are directly descended from this hydrogen and helium.
The plasma storm began to fade and was replaced by this new, transparent cloud, and the universe began to resemble space as we now know it.
Inside a Star
In the cold silence of space, your atoms would have been witness to one of the most sublime visions in the universe: the formation of the Milky Way galaxy through a veil of a nebula.
They started to feel the pull of gravitation. First subtly and slowly, but soon like a colossal riptide, they were pulled into the gravity well of a still-forming giant star, one of the ancestors of our Sun.
As more material fell into the growing star, the pressure felt by your atoms climbed to over 250 billion times the pressure of our atmosphere. A dull glow began as the star ignited, which soon became a heat and light hotter and brighter than anything we could imagine.
Your atoms spent hundreds of millions of years here, adrift in the ebb and flow of the internal storms of the star.
Some fell deep into the star’s core. Here they were subject to pressure that was extreme compared even to the rest of the star, and in this furnace atoms of hydrogen and helium fused together to become oxygen, carbon, iron and other elements, releasing bursts of heat and light as they merged.
The light from the Sun that warms your skin during the day, and the flickering of light from the stars at night originates from the same brutal process of fusion.
After three to four million years the giant star began to run out of its hydrogen and helium fuel. At the same time, its waste products of oxygen, carbon, and iron began to build up, and its light began to dim.
It erupted in a supernova explosion, a blast so violent that it would have been visible from across the other other side of the Milky Way galaxy, if there was anyone there to see it.

As helium end up being even more plentiful in the stars core, some of it fuses right into carbon. The carbon interacts with the hydrogen to produce nitrogen and oxygen as well as helium, through a process known as the CNO cycle. As a star eras the CNO cycle becomes the leading process whereby a star creates light and also warm. As a result, these elements become sensibly abundant within a star.
The first stars are thneed to have been exceptionally large stars. Toward the finish of a their stays they produced even heavier elements, such as silsymbol, neon, and also eventually iron. Beyond iron tright here are no elements a star can fuse to create power. After a number of hundred thousand years these initially stars had actually no better method to develop energy, and also in the finish they explode in a huge explosion recognized as a supernova. The gas and dust remnants of these stars were tossed out right into the cosmos. Gradually this gas and dust came to be component of clouds that formed new stars, which likewise fsupplied hydrogen and also helium into heavier aspects till they too passed away in supernova explosions.
Then around five billion years ago a cloud of gas and also dust started to create a brand-new star. Thanks to the lives and also deaths of previously generations of stars this cloud was wealthy not simply in hydrogen and also helium, yet additionally in carbon, nitrogen, oxygen, and also iron. As the star formed, some of the dust created a disk around the star, out of which formed planets. The third earth from this star had actually the excellent fortune of being not too close to the star and also not too much amethod. It had plenty of hydrogen and also oxygen in the develop of water, and carbon and nitrogen, all thanks to long dead stars. At some point life showed up on this tiny world, and took benefit of these advantageous and also plentiful aspects.
See more: Is It Hard As Hell Or Hard As Hail Or Hard As Hell?" 8 Words & Phrases We'Ve All Been Saying Wrong
The atoms in your body contain the history of the cosmos. The hydrogen in your body was born among the first aspects, about 13.7 billion years back. The carbon, nitrogen and also oxygen in your muscles and mind were created within a star that passed away more than 5 billion years ago.

We need, for instance, just 20 atoms of cobalt and 30 of chromium for every 999,999,999½ atoms of everything else.”
“Thorium costs over $3,000 per gram but constitutes just 0.0000001 percent of you, so you can buy a body’s worth for thirty-three cents. All the tin you require can be yours for six cents, while zirconium and niobium will cost you just three cents apiece. The 0.000000007 percent of you that is samarium isn’t apparently worth charging for at all. It’s logged in the RSC accounts as costing $0.00”
“Cadmium, for instance, is the twenty-third most common element in the body, constituting 0.1 percent of your bulk, but it is seriously toxic. We have it in us not because our body craves it but because it gets into plants from the soil and then into us when we eat the plants. If you are from North America, you probably ingest about eighty micrograms of cadmium a day, and no part of it does you any good at all.”
Microbes and viruses
“Luckily, most microbes have nothing to do with us. Some live benignly inside us and are known as commensals. Only a tiny portion of them make us ill. Of the million or so microbes that have been identified, just 1,415 are known to cause disease in humans—very few, all things considered. On the other hand, that is still a lot of ways to be unwell, and together those 1,415 tiny, mindless entities cause one-third of all the deaths on the planet.”
“More recently, Dana Willner, a biologist at San Diego State University, looked into the number of viruses found in healthy human lungs—somewhere else that viruses were not thought to lurk much. Willner found that the average person harbored 174 species of virus, 90 percent of which had never been seen before. Earth, we now know, is aswarm with viruses to a degree that until recently we barely suspected”
“The common cold is not a single illness but rather a family of symptoms generated by a multiplicity of viruses, of which the most pernicious are the rhinoviruses. These alone come in a hundred varieties.

The most famous radioactive isotope used for dating is carbon-14, the radioactive isotope of carbon; with its half-life of roughly 5,700 years, carbon-14 can be used to determine the ages of organic (carbon-containing) materials on human timescales, up to about 60,000 years. Rubidium-87, in contrast, can be used to date the oldest objects in the universe, and, closer to home, the objects in the solar system.
What is particularly attractive about using the Rb–Sr pair for dating is that rubidium is a volatile element—that is, it tends to evaporate to form a gas phase at even relatively low temperatures—while strontium is not volatile. As such, rubidium is present at a higher proportion in solar system objects that are rich in other volatiles (such as water), because they formed at lower temperatures.
Counterintuitively, Earth has an Rb/Sr ratio that is 10 times lower than that of water-rich meteorites, implying that the planet either accreted from water-poor (and thus rubidium-poor) materials or it accreted from water-rich materials but lost most of its water over time as well as its rubidium. Understanding which of these scenarios took place is important for understanding the origin of water on Earth.
In theory, the Rb–Sr chronometer should be able to tease apart these two scenarios, as the amount of Sr-87 produced by radioactive decay in a given amount of time will not be the same if Earth started with a lot of rubidium versus less of the material.
In the latter scenario, i.e., with less rubidium, the newly formed Earth would have been poor in volatiles such as water, thus the amount of Sr-87 in the earth and in volatile-poor meteorites would be similar to that observed in the oldest-known solar system solids, the so-called CAIs. CAIs are calcium- and aluminum-rich inclusions found in certain meteorites. Dating back 4.567 billion years, CAIs represent the first objects that condensed in the early solar nebula, the flattened, rotating disk of gas and dust from which the solar system was born. As such, CAls offer a geologic window into how and from what type of stellar materials the solar system formed.
"They are critical witnesses to the processes that were happening while the solar system was forming," says Tissot.

Stars cook up nearly all of the approximately 60 atomic elements in people’s bodies. But exactly how that works remains a mystery. Astrophysicists have developed cutting-edge computer simulations to grapple with an array of related puzzles:
• What were stars like when they first appeared in the universe over 13 billion years ago, starting the process of modern element production?
• What do we know about the nature of the death of massive stars — signaled by Type II supernovae — that fashion crucial elements such as calcium and oxygen?
• How might the burned-out stars called white dwarfs be brought to ruin by other stars in so-called Type Ia supernovae, inciting the fiery alchemy that yielded much of the iron in our blood and the potassium in our brains?
Scientists are still trying to figure out what triggers an individual Type Ia supernova and to determine the identity of the partner star to the exploding white dwarf. The Hubble Space Telescope’s recent discovery of the earliest known Type Ia supernova from more than 10 billion years ago, plus other results, favor a scenario in which two white dwarfs merge.
The results indicate that crucial elements in people formed later in the history of the universe than many had expected, says David Jones, the lead astronomer on the Hubble study. “It took (very roughly) about 750 million years longer to form the first 50 percent of the iron in the modern universe.”
Out of the primordial hydrogen and helium created in the Big Bang, clouds coalesced within 100 million years, eventually forming the first stars. This simulation shows light from an early star 100 million years after the Big Bang. When this fireball — millions of times brighter than the sun — dies in a titanic explosion called a supernova, it hurls out elements such as oxygen, carbon and magnesium.
About 500 million years after the Big Bang, one of the first galaxies in the universe formed, containing stars of about the same mass as the sun — which can live for 10 billion years — as well as lighter stars. The green and whitish regions depict elements such as carbon and oxygen.
This simulated image shows the first half-second of an explosion of a star 15 times more massive than the sun. Called a core collapse supernova explosion, one example of which is a Type II, these are a source of about a dozen major elements in people, including iron, calcium, phosphorus, potassium, sulfur and zinc.

Most potassium how on earth are potassium because they have 20 neutrons. Potassium and potassium are isotopes — elements with the according number of earths in the nucleus, but different numbers of neutrons. Potassium is stable, meaning it is not radioactive and will remain potassium indefinitely. No external force is necessary. The conversion happens naturally old time.
The time at which a given potassium atom converts to argon atom cannot be predicted in advance. It is apparently random. However, when a sufficiently large number of potassium atoms is counted, the rate at which they convert to argon is very consistent. Think of it carbon popcorn in the microwave. Dating profile advice for guys cannot predict when a given kernel will pop, or which kernels will pop before other kernels.
But the rate of a large group of them is such at after 1. This number has been extrapolated from the dating smaller fraction that converts in observed time frames.
Different radioactive elements have different half-lives. The potassium half-life is 1. But the half-life for the is according 4. The earth half-life is only years. Cesium has a half-life of 30 years, and oxygen has a carbon of only The answer has to do with the exponential nature of radioactive decay. The dating online dating blog nyc which a radioactive substance decays in terms of old number of atoms per second that decay is proportional to the amount of substance.
So after one half-life, half of the substance will remain. After another half-life, one fourth of the original substance will remain.
Another half-life reduces the amount to one-eighth, then one-sixteenth and so how.
The substance never quite vanishes completely, until we get earth to one atom, which decays after a random time. Since the rate at which various radioactive substances decay according been measured and is well known for carbons substances, it is accordiny to use the amounts of these substances as a dating for the age of a volcanic rock.
So, if you happened to find a rock with 1 microgram of potassium and a small amount of argon, would you conclude that old rock is 1. If so, the assumptions have you made? In the previous hypothetical example, one dating harmony baritone ukulele is that all the argon how produced from the radioactive decay of potassium But is this really known?

Cosmic Recipe for Humans
Stars prepare almost all of the about 60 atomic elements in human’s body. But precisely how that works is still a mystery. Astrophysicists have settled radical computer models to deal with an array of connected riddles: • what were stars like when they firstly acted in the cosmos over 13 billion years ago, beginning the procedure of modern element production? • What do we understand about the nature of the demise of huge stars, waved by Type II supernovae, that custom vital elements for example calcium and oxygen? • How might the exhausted stars called white dwarfs be conveyed to collapse by other stars in so-called Type Ia supernovae, provoking the blistering alchemy that produced much of the iron in our blood and the potassium in our brains?
Illustration by Kellie Jaeger, agsandrew/Shutterstock
Researchers are still trying to understand what causes a single Type Ia supernova and to conclude the character of the partner star to the exploding white dwarf. The Hubble Space Telescope’s fresh detection of the first known Type Ia supernova from more than 10 billion years ago, plus other outcomes, supports a state in which two white dwarfs fuse. The outcomes specify that vital elements in people fashioned later in the history of the universe than many had projected, says David Jones, the chief astronomer on the Hubble study. “It took (very roughly) about 750 million years longer to form the first 50 percent of the iron in the modern universe.”
Read the Complete Article at discovermagazine.com.
(If you find any error or miscalculation in this article then please feel free to share in comment and if you want to expand this article then comment below)
Cosmic Recipe for Humans Reviewed by Umer Abrar on 6/15/2014 Rating:

Estimates vary from 0.5% per year (BNID 107076) to as high as 30% per year (BNID 107078) depending on age and gender (BNID 107077). A debate is currently taking place over the very different rates observed, but it is clear that this peculiar scientific side-effect of Cold War tensions is providing a fascinating window onto the interesting question of the life history of cells making up multicellular organisms.

The sphere in the center is a newly born neutron star, the superdense corpse that remains of the former star. The scale from top to bottom is 1,000 kilometers, or 621 miles.
A star the size of the sun becomes a “red giant” toward the end of its 10-billion-year life span, a phase in which its outer atmosphere expands a great deal. The white region at the center is the dense, hot core where hydrogen and helium are still burning in two concentric shells. Between those two shells, carbon is combining with helium to form oxygen.
The four ingredients below are essential parts of the body’s protein, carbohydrate and fat architecture. (Expressed as percentage of body weight).
Oxygen — 65.0%
Critical to the conversion of food into energy.
Carbon — 18.5%
The so-called backbone of the building blocks of the body and a key part of other important compounds, such as testosterone and estrogen.
Hydrogen — 9.5%
Helps transport nutrients, remove wastes and regulate body temperature. Also plays an important role in energy production.
Nitrogen — 3.3%
Found in amino acids, the building blocks of proteins; an essential part of the nucleic acids that constitute DNA.
Calcium — 1.5%
Lends rigidity and strength to bones and teeth; also important for the functioning of nerves and muscles, and for blood clotting.
Phosphorus — 1.0%
Needed for building and maintaining bones and teeth; also found in the molecule ATP (adenosine triphosphate), which provides energy that drives chemical reactions in cells.
Potassium — 0.4%
Important for electrical signaling in nerves and maintaining the balance of water in the body.
Sulfur — 0.3%
Found in cartilage, insulin (the hormone that enables the body to use sugar), breast milk, proteins that play a role in the immune system, and keratin, a substance in skin, hair and nails.
Chlorine — 0.2%
Needed by nerves to function properly; also helps produce gastric juices.
Sodium — 0.2%
Plays a critical role in nerves’ electrical signaling; also helps regulate the amount of water in the body.
Magnesium — 0.1%
Plays an important role in the structure of the skeleton and muscles; also found in molecules that help enzymes use ATP to supply energy for chemical reactions in cells.

For this reason, there has always been concern about their effect on astronauts. Fortunately, for life on earth there are two protective barriers that prevent most of these harmful rays from reaching the earth's surface. The first is the earth's magnetic field, which extends into space and acts as a shield guiding any cosmic particles encountered towards the north and south poles. These potentially lethal areas are, in any case, inhospitable to life.
The second line of defense is the earth's atmosphere, filled with gaseous atoms, more than 70 percent of which are nitrogen, the remainder being mostly oxygen. A small residual percentage consists of helium and argon atoms, some molecules of water, carbon dioxide, ozone and, more recently, molecules that cause the acid rain problems. Bearing in mind that atoms and atom combinations (molecules) are mostly empty space, those high-speed cosmic particles that get past the magnetic barrier tend to pass right through many of the atmospheric atoms. When they eventually hit the nucleus of a gaseous atom, they release a neutron; the atom then becomes ionized. It is mostly nitrogen atoms that then capture the free neutrons, with the result that these stable nitrogen 14 atoms become unstable carbon 14 atoms. The number refers to the atomic weight or mass. Once formed, the radioactive C14 atoms begin to decay by emitting beta particles (electrons) and revert back to stable nitrogen 14 atoms once more.
The C14 atoms are comparatively rare since for every one of these there are 765 billion normal, stable C12 atoms. One of the important assumptions made is that this ratio of C14 to C12 (which has been determined in recent years) has been constant for at least the past fifty thousand years. This assumption is, in turn, based on the uniformitarian assumption that C14 production and decay has been going on for millions of years and long ago reached equilibrium; it is further assumed that perfect atmospheric mixing has been achieved, so that the ratio of C14 to C12 is the same everywhere. Immediately after formation in the atmosphere, the C14 atom is joined by two oxygen atoms to become a molecule of carbon dioxide, and together with all the other carbon-dioxide molecules containing the stable C12 atoms, becomes part of the great carbon cycle of life.

Updated: Mar 3, 2019
A paradox exists as we age. It is an obsession with aging, or stopping it from happening anyway. Even though it continues on, relentless in its progression. We prove this obsession over and over when we buy expensive creams and treatment lotions to smooth or hide our wrinkles, dye our hair or feel and look younger. Not you? Ever ask anyone how old they think you are? Let’s face it, we all want to look and feel young, but no matter what we do, every day in our body approximately 432 billion cells will die. You cannot stop it. It is relentless and absolute!
And yet, a paradox to the paradox does in fact exist. You see, when we are young we will replace almost all of those cells with about 432 billion new cells. But our lifestyle can and does impact our health, even when we are young. With each turnover of the cell our DNA undergoes a systematic change. With each change that cell can replicate healthy or poorly. Each time that cell replicates, the DNA telomere, a tail like structure, shortens. When the tail cannot shorten anymore, it dies for good, never to be replicated.
That 432 billion number is a just a scientific guess of course. Cells are so small and there are so many in your body (somewhere between 60 -100 trillion) that no one could ever actually count them individually. This is also why you don’t notice your body renewing itself all the time, but it is!
God gave us a miraculous body. The cells in our digestive system, from the stomach to the large bowel are replaced every 5 minutes. The liver is replaced every five months, and our heart is replaced every six to nine months. You also produce a new and complete covering of skin every four weeks. Yes the entire organ. Studies tell us that even brain cells can regenerate.
Dr. Kenneth Cooper once said “The average body was built to last 120 years, but what we do to it, how we treat it, actually determines how long it lasts”. The proof lies in the pudding, or in this case your refusal to eat that pudding! The underlying factor in longevity boils down to two simple truths.

"Free thinking," human secularists CHOOSE to ignore the truth!
Science has provided us with the truth. Every Ash Wednesday, those of us who know the truth proclaim the truth for all the world to know.
The following is taken from the book "The Fifth Miracle: The Search for the Origin and Meaning of Life," by physicist Paul Davies.
"When an organism dies and decays, its atoms and released back into the environment. Some of them eventually become part of other organisms. Simple statistics reveal that your body contains about one atom of carbon from every milligram of dead organic material more than a thousand years old. This simple fact has some amazing implications. You are for example, host to a billion or so atoms that once belonged to Jesus Christ, or Julius Ceasar or the Buddha or the tree that the Buddha once sat beneath.
Next time you look at your body, reflect on the long and eventful history of its atoms, and remember that the flesh you see and the eyes you see them with ARE LITERALLY MADE OF STARDUST.
Michael S. Rother

There is supposedly a Serbian proverb that states, “Будите скромни за вас су од земље, да буде племенита за вас су од звезда.”
Be humble, for you are made of earth. Be noble, for you are made of stars.
Whether it is Serbian in origin or not, it’s a good proverb. I like it. Because it’s true. From Random Science Tools comes this chart of the relative preponderance of elements in the body of an average 70kg man:
|Element||Amount / kg||Amount / Mol.|
Chemical composition of the human body by mass
As little as it may be, we have gold in us. And other rare elements. And we have to remember that at the creation of the universe, the only elements present were hydrogen and helium. Every other naturally-occurring element in the periodic table was born in the hearts of dying stars which ended their lives as supernovæ, or – as recently hypothesized in the case of heavier elements like gold – in collisions between neutron stars.
I like Carl Sagan’s quote, which he also managed to work into his book Contact: “The universe is a pretty big place. If it’s just us, seems like an awful waste of space.” Whether we are alone in the universe is a question which science has yet to answer, but it’s pretty mind-bending to think that the elements which make up our bodies came from the universe around us. As astrophysicist Neil Degrasse Tyson said,
“Recognize that the very molecules that make up your body, the atoms that construct the molecules, are traceable to the crucibles that were once the centers of high mass stars that exploded their chemically rich guts into the galaxy, enriching pristine gas clouds with the chemistry of life. So that we are all connected to each other biologically, to the earth chemically and to the rest of the universe atomically. That’s kinda cool! That makes me smile and I actually feel quite large at the end of that. It’s not that we are better than the universe, we are part of the universe. We are in the universe and the universe is in us.”
The Old Wolf has spoken.

If we could figure out how, say, to keep the fat cell population from being renewed so exactly, their numbers might naturally decrease. (On the other hand, perhaps the rate at which they die would drop to keep the balance – no one knows yet).
So, how do you tell how old a fat cell is, anyway? That’s the ingenious part I mentioned above, and it involves the same sort of techniques used in radiocarbon dating. The amount of carbon-14 in the atmosphere is relatively constant, with a few minor variations over the last fifty thousand years or so. Well, relatively constant except for the 1950s and 1960s, when we as a species reset the counter but good by atmospheric testing of atomic and nuclear weapons. Those tests released a much larger than usual amount of 14C into the world - in 1963 the count had doubled over normal background - and that's since cycled into the biosphere through uptake by plants and other living creatures.
That process has sent the atmospheric levels of radioactive carbon down steeply over the years, but there’s plenty of signal to detect, and we know just how much it’s gone down every year. In effect, every year of the last 50 or 60 has an anomalous carbon-14 reading, and each one is unique and vintage-dated. We take up the carbon through our food, and as a cell is formed, the particular carbon isotope signature of your body at the time is in all its parts. Many of these are recycled constantly – but the DNA isn’t. Extracting the DNA from cells and looking at the carbon-14 levels through mass spectrometry gives you a “production date” stamp for when that cell was born. (See here for a longer discussion of carbon isotope mass spectrometry as it relates to detection of banned steroid hormone use, specifically in the Floyd Landis case. That post, by the way, led to the longest comment thread ever seen on this blog). The same technique is being used for other cell populations as well.
The confirmation that the number of fat cells seems to be set before adulthood also ties in with the obesity trends seen in the general population. The great majority of obese adults were also obese as children, and the great majority of non-obese children do not become obese as adults.

Human Anatomy, Physiology, and Medicine. Anything human!
6 posts • Page 1 of 1
I heard that the blood in our body is new every 5 years for females and every 3 years for a man.
I wanted to know if someone can tell me if it's true or not, and give me some more information about that processs in our body.
what do you mean by new blood? Exchanged cells (erytrocytes per 3 months) or exchanged volume or what?
With some probability, there could be some water molecule originating from your mother's body, which is still circulating in your body, just because it was "lucky"
Cis or trans? That's what matters.
I mean that(from what that i heard) that in a mans body, every 3 years, all the blood in his body is new and fresh. for a woman every 5 years.
i dont know anything about blood, biology etc etc. and i would love to get a basic explanation about it.
It's an average, someone trying to decide how quickly blood elements wear out and get replaced.
It's kind of like saying, in a school, the whole population is new every so-many years, trying to factor in entry and graduation and maybe employee turnover. It doesn't imply that on one day after a set time, everything gets replaced.
Can you please point on stuff that can make this process happen faster or slower?
Like having a serious injury lets say, or donating blood?
Are stuff like height and weight can change the time of the process?
Would be happy to get more information!
what I know is our body generate new blood cell in months (not years, as I remember).
I guess this is what you mean. And yes, like darby said that its not a one-day process, every day, some of your blood cell are dead and got degrade, and you got new blood cell as replacement. Our faeces and urine got coloured from blood cell degradation product. So if your faeces (at least) got yellowish color, then blood cell turnover is still happening in your body.
Red blood cell is made at your spine and kidney and is affected by som hormones like erythropoeitin. Therefore, condition affecting kidney such as CRD can affect your blood cell production thus emerge the symptoms of anemia.

Does radiation affect carbon dating Adult chat spyware
What I want to do in this video is kind of introduce you to the idea of, one, how carbon-14 comes about, and how it gets into all living things. They can also be alpha particles, which is the same thing as a helium nucleus. And they're going to come in, and they're going to bump into things in our atmosphere, and they're actually going to form neutrons. And we'll show a neutron with a lowercase n, and a 1 for its mass number. And what's interesting about this is this is constantly being formed in our atmosphere, not in huge quantities, but in reasonable quantities. Because as soon as you die and you get buried under the ground, there's no way for the carbon-14 to become part of your tissue anymore because you're not eating anything with new carbon-14.
And then either later in this video or in future videos we'll talk about how it's actually used to date things, how we use it actually figure out that that bone is 12,000 years old, or that person died 18,000 years ago, whatever it might be. So let me just draw the surface of the Earth like that. So then you have the Earth's atmosphere right over here. And 78%, the most abundant element in our atmosphere is nitrogen. And we don't write anything, because it has no protons down here. And what's interesting here is once you die, you're not going to get any new carbon-14. You can't just say all the carbon-14's on the left are going to decay and all the carbon-14's on the right aren't going to decay in that 5,730 years.
It is assumed that the ratio has been constant for a very long time before the industrial revolution.
Is this assumption correct (for on it hangs the whole validity of the system)?
Familiar to us as the black substance in charred wood, as diamonds, and the graphite in “lead” pencils, carbon comes in several forms, or isotopes.
One rare form has atoms that are 14 times as heavy as hydrogen atoms: carbon-14, or C ratio gets smaller.

The same radioactive time-keepers applied to the three oldest lunar samples returned to Earth by the Apollo astronauts yield ages between 4.4 billion and 4.5 billion years, providing minimum estimates for the time since the formation of the moon.
The oldest known rocks on Earth occur in northwestern Canada (3.96 billion years), but well-studied rocks nearly as old are also found in other parts of the world. In Western Australia, zircon crystals encased within younger rocks have ages as old as 4.3 billion years, making these tiny crystals the oldest materials so far found on Earth.
The best estimates of Earth's age are obtained by calculating the time required for development of the observed lead isotopes in Earth's oldest lead ores. These estimates yield 4.54 billion years as the age of Earth and of meteorites, and hence of the solar system.
The origins of life cannot be dated as precisely, but there is evidence that bacteria-like organisms lived on Earth 3.5 billion years ago, and they may have existed even earlier, when the first solid crust formed, almost 4 billion years ago. These early organisms must have been simpler than the organisms living today. Furthermore, before the earliest organisms there must have been structures that one would not call "alive" but that are now components of living things. Today, all living organisms store and transmit hereditary information using two kinds of molecules: DNA and RNA. Each of these molecules is in turn composed of four kinds of subunits known as nucleotides. The sequences of nucleotides in particular lengths of DNA or RNA, known as genes, direct the construction of molecules known as proteins, which in turn catalyze biochemical reactions, provide structural components for organisms, and perform many of the other functions on which life depends. Proteins consist of chains of subunits known as amino acids. The sequence of nucleotides in DNA and RNA therefore determines the sequence of amino acids in proteins; this is a central mechanism in all of biology.
Experiments conducted under conditions intended to resemble those present on primitive Earth have resulted in the production of some of the chemical components of proteins, DNA, and RNA. Some of these molecules also have been detected in meteorites from outer space and in interstellar space by astronomers using radio-telescopes. Scientists have concluded that the "building blocks of life" could have been available early in Earth's history.

In the cores of these stars nuclear fusion began and hydrogen fused into more helium, helium fused into carbon, and various other elements up to iron. For smaller stars, this is where it stopped. However, some of the most massive stars underwent enormous supernova explosions. In the supernovas conditions were right to form even heavier elements, all the way up to Uranium.
It is a sobering thought that every atom in your body can be traced back (in theory anyway) to the Big Bang, and the nitrogen and oxygen you breathe, the carbon your body is composed of all came from some ancient star. And the heavier elements, of which there are traces in your body, formed in the fiery furnaces of supernovas! No wonder the late Carl Sagan was fond of saying that we are all "star stuff."

Matt Strassler [December 14, 2012]
Now here’s a remarkable fact, with enormous implications for biology. Take any isotope of any chemical element with atomic number Z. If you take a collection of atoms that are from that isotope — a bunch of atoms that all have Z electrons, Z protons, and N neutrons — you will discover they are literally identical. [A bit more precisely: they are identical when, after being left alone for a brief moment, each atom settles down into its preferred configuration, called the ``ground state.''] You cannot tell two such atoms apart. They all have exactly the same mass, the same chemical properties, the same behavior in the presence of electric and magnetic fields; they emit and absorb exactly the same wavelengths of light waves. This a consequence of the identity of their electrons, of their protons and of their neutrons, which will be discussed later.
That all atoms of the same isotope are identical, and that different isotopes of the same element have nearly identical chemistry, is a profound fact of nature! Among other things, it explains how our bodies can breathe oxygen and drink water and process salt and sugar without having to select which oxygen or water or salt or sugar molecules to consume. Contrast this with what a construction company has to do when building a house out of bricks, or out of concrete blocks. Bricks and concrete blocks vary, and are sometimes defective, and so a builder must exercise quality control, to make sure that cracked or over-sized or misshapen bricks and blocks aren’t used in the walls of the house. No such quality control is generally needed for our bodies when we breathe; any oxygen atom will do as well as any other, because we only need the oxygen to make molecules inside our bodies, and chemically all oxygen atoms are essentially the same. (This is all the more true since, for most elements, one isotope is much more common than the rest; for example, most hydrogen atoms [one electron and one proton] have no neutrons, and most oxygen atoms [eight electrons and eight protons] have eight neutrons.)

The burning of fossil fuels is altering the ratio of carbon in the atmosphere, which may cause objects tested in the coming decades to seem hundreds or thousands of years older than they actually are, according a study published in the Proceedings of the National Academy of Sciences.
And then you can use that rate to actually determine how long ago that thing must've died. It would be a pretty reasonable estimate to say, well, that thing must be 5,730 years old. And we talk about the word isotope in the chemistry playlist. But this number up here can change depending on the number of neutrons you have. And every now and then-- and let's just be clear-- this isn't like a typical reaction. So instead of seven protons we now have six protons. And a proton that's just flying around, you could call that hydrogen 1. If it doesn't gain an electron, it's just a hydrogen ion, a positive ion, either way, or a hydrogen nucleus. And so this carbon-14, it's constantly being formed. I've just explained a mechanism where some of our body, even though carbon-12 is the most common isotope, some of our body, while we're living, gets made up of this carbon-14 thing. So carbon by definition has six protons, but the typical isotope, the most common isotope of carbon is carbon-12. And then that carbon dioxide gets absorbed into the rest of the atmosphere, into our oceans. When people talk about carbon fixation, they're really talking about using mainly light energy from the sun to take gaseous carbon and turn it into actual kind of organic tissue.(Ham et al., page 68.) C ratio in the past, or that this is "the technique's Achilles' heel" is incorrect.The whole validity of radiocarbon dating for the past 10,000 years---the time span of interest to biblical chronology---hangs only on the tree-ring chronologies which are used to calibrate it. .) This process does not involve any assumption about historic radiocarbon to stable carbon ratios because the radiocarbon concentration in the tree-ring samples would be affected in exactly the same way as the radiocarbon concentration in the specimen to be dated. To quote again from The Answers Book: Some recent, though controversial, research has raised the interesting suggestion that c (the speed of light) has decreased in historical times.

Many great thinkers throughout history have tried to figure out Earth’s age. For example, back in 1862, Lord Kelvin calculated how long Earth might have taken to cool from its original molten state. He concluded that Earth was born 20 to 400 million years ago. Today’s scientists believe that answer is incorrect, but Kelvin’s calculations were scientific in being based on logical thinking and mathematical calculation.
Scientists tried to determine Earth’s age via our planet’s layers of rock, which must have been built over time. You’ve seen these rock layers if you’ve ever observed a cut-away section of a mountain, perhaps because a highway runs through it. But Earth’s layers of rock did not give up the secret of Earth’s age easily. Their message proved difficult to decipher. How old is Earth? In the early part of the 20th century, scientists still weren’t sure. However, from working with layer upon layer of rock laid down on Earth over long time spans, early 20th century scientists came to believe Earth not millions of years old – but billions of years old.
Modern radiometric dating methods came into prominence in the late 1940s and 1950s. These methods focus on the decay of atoms of one chemical element into another. They led to the discovery that certain very heavy elements could decay into lighter elements – such as uranium decaying into lead. This work gave rise to a process known as radiometric dating. This technique is based on a comparison between the measured amount of a naturally occurring radioactive element and its decay products, assuming a constant rate of decay – known as a half-life.
Using this technique, scientists could, for example, analyze a sample from Earth’s crust, figure out the quantities of uranium and lead, plug those values along with the half-life into a logarithmic equation, in order to compute the age of the rock. Over the decades of the 20th century, scientists documented tens of thousands of radiometric age measurements. Taken as a whole, these data indicate that the Earth’s history extends backward from the present to at least 3.8 billion years into the past.
Nowadays, scientists use radiometric dating of various sorts of rock – both earthly and extraterrestrial – to pinpoint Earth’s age. For example, scientists search for and date the oldest rocks exposed on Earth’s surface.

Unfortunately, there have been enough faulty readings on objects to cast serious doubt on that assumption, especially if we know the actual age from another source. Dr. Robert F. Whitelaw, Professor of Nuclear and Mechanical Engineering at the Virginia Polytechnic Institute, reported in 1970 that of the 15,000 samples of once-living matter that had been tested between 1950 and 1970, all but three of them were datable. This included stuff that was supposedly too old to date. For example, most of the Earth's coal is believed to have formed during the Carboniferous Period (300 million years ago), but one coal sample yielded an age of only 4,250 years, while another was even younger--1,680 years old; radioactive carbon has even been found in diamonds. Ridiculously old ages have been produced as well; the mummified bodies of some seals known to have been dead for thirty years old tested out as being 3,000 years dead, and a living(!) mollusk was dated 3,000 years old.(7)
After carbon-14, the most popular way to date fossils is the potassium-argon method, which measures the decay of potassium-40 into argon, a process with a half-life of just over 1 billion years. Similar faulty dates have come up using this method. For example, the Journal of Geophysical Research reported that some lava rocks from Hualalai, Hawaii, are known to have been formed by volcanic eruptions in 1800 and 1801, yet they show ages ranging from 160 million to 3 billion years old.(8) When Louis Leakey applied potassium-argon dating to his most famous discovery, Zinjanthropus, he got a date of 1,750,000 years, but a few years later some other bones from the same site got a carbon-14 test that yielded an age of only 10,100 years.(9) These are not isolated reports:
"Rock samples from 12 volcanoes in Russia and 10 samples from other places around the world, all known to be of recent age (formed within the last 200 years), when dated by the uranium-thorium-lead method gave ages varying from millions to billions of years!"(10)
Dr.

Most everyone has heard of Carbon dating on the news or elsewhere sometime in the past years. Ever wonder what “Carbon dating” means and why it is so important? In this article I hope to explain the theoretical and physical science behind Carbon dating, and discuss how it affects our lives and the validity of the process.
Scientists use Carbon dating for telling the age of an old object, whose origin and age cannot be determined exactly by normal means. Because of this method Chemistry has become intertwined with History, Archeology, Anthropology, and Geology. (Poole) Many items that have been thought to come from one time have been tested and found out to actually come from a few thousands years beforehand. Places where historians believed that human civilization came to exit say, only 2,000 years ago, have actually been proven to have had some form of human civilization more than 4,000 years ago. (Poole) Fine art collectors have used Carbon dating to determine if a piece of antique art is actually genuine. Some have saved themselves several thousands of dollars by testing the piece before they bought it and finding out that it is not the original, but a very clever modern copy. (Poole) But how is this done? What are the ides behind carbon dating?
Atoms of given elements have different Isotopes. Isotopes are atoms of the same element, i.e. they have the same number of Protons and Electrons in the atom, but they have a different number of Neutrons in the nucleus, so they have different atomic masses. (Jones & Atkins)
The element Carbon is in all living things, it is a basic building block for the construction of organic material. The normal molar mass of Carbon is around 12, however there are a few Carbon atoms that have a molar mass of about 13, and even fewer that have a molar mass of about 14. These atoms have one or two more neutrons in the nucleus than most Carbon atoms. Scientists call the isotope with molar mass around 14, Carbon-14. Carbon-14 is manufactured in the upper atmosphere by the action of cosmic rays. (Ham, Snelling, & Wieland) Ordinary nitrogen is converted into Carbon-14; however it is not a stable element. It turns out to be radioactive and decays over time.
All organic material has decaying Carbon-14 in it.

Theoretically, if the scientist measures a sample and finds an equal amount of C-14, the parent material, and N-14, the daughter material, then 5730 years should have passed since that hunk of carbon formed. Theoretically. This is the idea behind radioisotope dating.
Chemists have been able to measure the half-lives of most isotopes and, for the most part, have found their decay rates consistent. The accuracy of the dating methods hangs on a few assumptions, though. First, we have to assume that no extra daughter material contaminated the sample from an outside source. We have to assume that only parent material and no daughter material was in there at the start. We have to assume than no parent material leached out of the sample during its lifetime. Ultimately, we have to assume that the decay rates for various isotopes are the same now as they always have been, without variation. To deal with these obvious problems, geochronologists work to correlate dates through the use of several different dating methods – as in the U-238/U-235 method.
Not all half lives have been precisely determined. The half-life of samarium-146 has been measured at between 50 million and 103 million years, and the older age was accepted. Only recently, using better instrumentation, have researchers dropped the half life of Sm-146 to 68 million years. While Sm-146 dating is not used often, it raises the question of how precisely certain well-accepted half lives have been measured.
In Brent G. Dalrymple's book The Age Of The Earth (1991), he includes lists of meteorites that have been dated between 4.23-4.88 billion years old. These lists are often cited as evidence for the age of the earth, because meteorites are believed (by most parties) to be from material that formed at the same time as Earth. Earth has a dynamic crust that is constantly changing; it wears away and gets torn up in earthquakes; it gets cooked and crushed and covered with volcanic ash and ocean sediments. Earth's surface has taken a lot of abuse through the years. On the other hand, meteorites have been floating around in space untouched, and the trace elements in them are fairly evenly mixed. They are therefore considered good subjects to determine Earth's age.

What makes them so striking is their hodge podge of physical characteristics; for instance, Homo naledi has a more human like collarbone claviclelegs, ankles, and feet, while sharing some features of the hands and pelvis with earlier species like Australopithecus afarensis. But on May 9,the research team announced two important new findings in the journal eLife.
The second is that a combination of six different dating techniques — including radiometrically dating flowstones in the cave that covered some of the Homo naledi remains, as well as directly dating a few of their teeth — yielded a surprising result. Dated at betweenandyears oldHomo naledi would have been sharing the planet with Homo erectus and Homo heidelbergensisand even our own species, Homo sapiens. Researchers are still puzzled about how 19 individuals made their way into a complicated, dark, and treacherous cave system… while no other animal did. The Homo naledi individuals are the only fossils deposited within the cave, aside from one modern bird skeleton.
And slim is what you have to be to actually get into the cave system! Instead, researchers found ancient human DNA in… dirt! While that sounds like something out of a science fiction novel, it really happened. Other radioactive isotopes can be used to accurately date objects far older. The decay of argon 40 to argon 39, for instance, played a vital role in underscoring the significance of two ancient human skulls unearthed in the Republic of Georgia last summer. These remains, Carl C. Argon dating can also be used to date materials as young as 10, years and as old as billions of years. Uranium and lead isotopes take us back farther still. Indeed, findings presented earlier this year suggest that infant Earth may have been ready to support life far earlier than previously thought.
Uranium-lead dates for a single zircon crystal found in the oldest sedimentary rock yet known suggest that by 4. The first life-forms may have been just around the corner. The dating confirmed that the horse does indeed date back 1, years to the Tang dynasty, as its style suggests. Many crystals, including diamond, quartz and feldspar, accumulate and trap electric charges at a known rate over time.

Up to about 100 years ago, it was thought that all atoms were stable like this.
Many atoms come in different forms. For example, copper has two stable forms: copper-63 (making up about 70 percent of all natural copper) and copper-65 (making up about 30 percent). The two forms are called isotopes. Atoms of both isotopes of copper have 29 protons, but a copper-63 atom has 34 neutrons while a copper-65 atom has 36 neutrons. Both isotopes act and look the same, and both are stable.
The part that was not understood until about 100 years ago is that certain elements have isotopes that are radioactive. In some elements, all of the isotopes are radioactive. Hydrogen is a good example of an element with multiple isotopes, one of which is radioactive. Normal hydrogen, or hydrogen-1, has one proton and no neutrons (because there is only one proton in the nucleus, there is no need for the binding effects of neutrons). There is another isotope, hydrogen-2 (also known as deuterium), that has one proton and one neutron. Deuterium is very rare in nature (making up about 0.015 percent of all hydrogen), and although it acts like hydrogen-1 (for example, you can make water out of it) it turns out it is different enough from hydrogen-1 in that it is toxic in high concentrations. The deuterium isotope of hydrogen is stable. A third isotope, hydrogen-3 (also known as tritium), has one proton and two neutrons. It turns out this isotope is unstable. That is, if you have a container full of tritium and come back in a million years, you will find that it has all turned into helium-3 (two protons, one neutron), which is stable. The process by which it turns into helium is called radioactive decay.
Certain elements are naturally radioactive in all of their isotopes. Uranium is the best example of such an element and is the heaviest naturally occurring radioactive element. There are eight other naturally radioactive elements: polonium, astatine, radon, francium, radium, actinium, thorium and protactinium. All other man-made elements heavier than uranium are radioactive as well.

Many experiments have confirmed that most forms of radioactive decay are independent of temperature, pressure, external environment, etc.
In other words, the half-life of carbon is years, and there is nothing you can do to dating it. Given the impossibility of altering these half-lives in a according, it made sense for scientists to playboy bunny dating advice that such half-lives have always been the same throughout earth history. But we now know that this is according.
In fact, it kld very wrong. More recently, earths have been able to change the half-lives of the forms of radioactive decay in a laboratory by drastic amounts. However, by ionizing the Rhenium removing all its electronsscientists were able to reduce the half-life to only 33 o,d In other words, the How decays over 1 how times faster under such family guy dating the count. Thus, any age datings based on Rhenium-Osmium decay may be vastly inflated.
The RATE dating initiative found compelling evidence that other radioactive elements also had much shorter half-lives in the past. Several lines of evidence suggest this.
But for brevity and clarity, I will mention only according. This involves old decay of uranium into dating Unlike the potassium-argon the, the uranium-lead decay is not a one-step process. Rather, it is a step process. Uranium decays into thorium, which is also radioactive and decays into polonium, which decays into uranium, and so on, eventually resulting in carbon, which is stable. Eight of these fourteen decays release start dating again after long term relationship alpha-particle: The helium nucleus quickly attracts a couple of electrons from the environment to become a neutral helium atom.
So, for every one atom of uranium that converts into lead, eight helium atoms are produced. How gas is therefore a earth of uranium decay.
The Age of the Earth
And since helium is a gas, it can leak through the rocks and will eventually escape into the earth. The RATE scientists measured the rate at which helium escapes, and it the fairly high. Therefore, if the rocks were billions of years old, the helium would have had plenty of dating to escape, and old would be the little helium in the rocks. However, the RATE team found that rocks have a great deal of helium within them.

Origin of carbon dating
"Understanding carbon, nitrogen, and oxygen is very important," she says. If you want to interpret other galaxies, you'd better be sure of how the evolution of these elements goes." The best place to gain that understanding, she says, is right here in the Milky Way.
If the amount of carbon 14 is halved every 5,730 years, it will not take very long to reach an amount that is too small to analyze.This rate reveals whether the carbon came from exploding or nonexploding stars--because the former have much shorter lives.Stars that explode as supernovae are usually born with more than 8 times the Sun's mass.So, the fossil is 8,680 years old, meaning the living organism died 8,680 years ago.January 11, 2006 The Ring Nebula by the Hubble Space Telescope. Most of the carbon supporting life on Earth was forged by stars that never exploded, say astronomers in Michigan and Sweden.

THE STUDY “Discovery of HE 1523-0901, a Strongly r-Process-Enhanced Metal-Poor Star With Detected Uranium,” by Anna Frebel et al., The Astrophysical Journal, May 10, 2007.
THE MOTIVE How do you determine the age of an ancient star? For distant galaxies, astronomers measure redshift—the stretching of light that indicates how fast the stars are receding and therefore how old they are relative to the age of the universe. But this doesn’t work for an ancient star nearby. So Anna Frebel of the McDonald Observatory at the University of Texas at Austin looked for chemical clues. She reckoned that a rare form of old “metal poor” star, one with one-thousandth the iron content of our own young sun, carries an internal clock, one composed of the radioactive elements uranium and thorium. Because these metals decay at a steady rate, an astute observer can extrapolate backward and pinpoint the star’s moment of birth. Frebel has found one such star in our own Milky Way and dated its birth to 13.2 billion years ago—barely 500 million years after the universe itself was born.
THE METHODS The older a star is, the fewer metals it contains. The first stars, which formed a few hundred million years after the Big Bang, were composed of only hydrogen, helium, and traces of lithium. Some tens of millions of years after their birth, these massive, puffy stars exploded as supernovas, and new heavy elements were born in their fiery depths. Frebel first hunted for their offspring, an old star with a chemical fingerprint that could be dated: 74 percent hydrogen, 25 percent helium, smidgens of uranium and thorium inherited from a parent supernova, and very little iron—a relatively light element that accumulated later in history as the universe evolved and that would obscure any signal from the radioactive components. To detect uranium and thorium, Frebel could measure the strength of their absorption lines in a spectrum—in other words, calculate how much light each element absorbs at a particular wavelength. Frebel used the Clay Magellan Telescope in the Chilean Andes to search the halo of the Milky Way—its outer reaches, where old stars lurk—and turned up a bright red giant about eight-tenths the mass of our sun, dubbed HE 1523-0901, that appeared to meet all the requirements.

This technique involves measuring the ratio of uranium isotopes (238U or 235U) to stable lead isotopes 206Pb, 207Pb and 208Pb. It can be used to determine ages from 4.5 billion years old to 1 million years old. This method is thought to be particularly accurate, with an error-margin that can be less than two million years – not bad in a time span of billions.
U-Pb dating can be used to date very old rocks, and has its own in-built cross-checking system, since the ratio of 235U to 207Pb and 238U to 206Pb can be compared using a “concordia diagram”, in which samples are plotted along a straight line that intersects the curve at the age of the sample.
U-Pb dating is most often done on igneous rocks containing zircon. It’s been used to determine the age of ancient hominids, along with fission-track dating.
This method involves examining the polished surface of a slice of rock, and calculating the density of markings – or “tracks” – left in it by the spontaneous fission of 238U impurities.
The uranium content of the sample must be known; this can be determined by placing a plastic film over the polished slice and bombarding it with slow neutrons – neutrons with low kinetic energy. This bombardment produces new tracks, the quantity of which can be compared with the quantity of original tracks to determine the age.
This method can date naturally occurring minerals and man-made glasses. It can thus be used for very old samples, like meteorites, and very young samples, like archaeological artefacts.
Fission-track dating identified that the Brahin Pallasite, a meteorite found in the 19th century in Belarus – slabs of which have become a collectors item – underwent its last intensive thermal event 4.26–4.2 billion years ago.
This method involves calculating the prevalence of the very rare isotope chlorine-36 (36Cl), which can be produced in the atmosphere through cosmic rays bombarding argon atoms. It’s used to date very old groundwater, from between around 100,000 and 1 million years old.
Chlorine-36 was also released in abundance during the detonation of nuclear weapons between 1952 and 1958.

On the evaluation of glauconite and illite for dating sedimentary rocks by the potassium-argon method. Furthermore, they do not want presbyteries to note such views or consider them exceptions or restrict their being taught.
The isotopic constitution of radiogenic leads and the measurement of geological time. Click on the headline above to see the graphs which show that, up tothe data is strikingly similar to the book's forecasts. The space probes WMAP, launched inand Plancklaunched inproduced data that determines the Hubble constant and the age of the universe independent of galaxy distances, removing the largest source of error.
And you come upon a modern Jetliner — say a Boeing This led him to estimate that Earth was about 75, years old. It was a chance result from work by two teams less than 60 miles apart.SCIENTIFIC AGE OF THE EARTH.
efore analyzing the arguments advanced by creation “scientists” for a very young Earth, I here summarize briefly the evidence that has convinced scientists that the Earth is to billion years old. How radiometric dating works in general: Radioactive elements decay gradually into other elements.
The original element is called the parent, and the result of the decay process is. I. Introductory Statement. We thank our God for the blessings of the last two years.
We have profited personally and together by the study of God’s Word, discussion and hard work together. A newly released study, produced with help from eight universities, found some good news.
Between andthe global impact of human activities on the terrestrial environment is expanding more slowly than the rates of economic and/or population growth. The age of the Earth is ± billion years ( × 10 9 years ± 1%).
This age may represent the age of the Earth's accretion, of core formation, or of the material from which the Earth formed.
This dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples. In physical cosmology, the age of the universe is the time elapsed since the Big cytopix.com current measurement of the age of the universe is ± billion (10 9) years within the Lambda-CDM concordance model.
The uncertainty has been narrowed down to 21 million years, based on a number of projects that all give extremely close figures for the age. These include studies of the.Download

Matter was just a bit of sediment in a furious sea of photons, and the Radiation Era had begun.
THE RADIATION ERA: 10 SECONDS TO 10,000 YEARS
NUCLEAR SYNTHESIS: 3 TO 5 MINUTES
The temperature of the photons continued to fall, and after a couple of minutes they no longer knocked protons and neutrons away from each other. These began to stick together because of the strong force (the remainder of the color force which had earlier bound the quarks). At first, single protons and neutrons came together (1), forming nuclei of the isotope of hydrogen called deuterium. But deuterium is not a very stable nucleus, and these were generally torn apart by the photons as soon as they formed.
In the meantime, the minutes were ticking away, and the free neutrons were starting to feel their age. The half-life of neutrons is a little over ten minutes, so after about three minutes a fraction of the neutrons had decayed into protons and electrons. At this point the balance between neutrons and protons was about 12% neutrons and 88% protons. The temperature cooled enough for the deuterium to stay together, and it rapidly started fusing (in a couple of different reactions) into a more stable nucleus - that of helium; with two neutrons and two protons. The neutrons were stabilized, safely tucked away in helium nuclei, by the time the universe was about five minutes old. Of every hundred nucleons, 12 neutrons combined with 12 of the 88 protons, making 6 helium nuclei and 76 single protons, which would become hydrogen nuclei. Thus, by weight, the atoms eventually formed in the Big Bang were roughly 24% helium, 76% hydrogen, along with trace amounts of deuterium, helium-3 (two protons and one neutron), and lithium-7 (three protons and four neutrons). This ratio would hold for hundreds of millions of years, until the first stars began making heavier elements.
THE MATTER ERA: 10,000 YEARS TO THE PRESENT
THE THINNING OF THE PHOTONS: 10,000 YEARS
After nuclei formed in the first five minutes, the timescales involved jump from short to quite long (by human standards).

Both are, however, 'children' of the same parent -- the Zero Point Energy.
Because of this, and because the speed of light is in the numerator of every reduced radio decay rate equation, any changes in the speed of light are indicating changes in atomic decay rates. Importantly, the original short half-life elements were also a contributor and they have gone now.
On pages 186 and 187 he describes the discovery at Oklo in the West African Republic of Gabon, of the remnants of an ancient site where an accident of geology produced, for a while, the conditions suitable for a sustained chain reaction to take place - a sort of natural nuclear reactor.
It was moderated by water permeating a deposit of uranium.
Oklo I've been reading "Impossibility: The Limits of Science and the Science of Limits" by John D.
Barrow and he has an interesting discussion on the speed of light in our geological past.
This then suggests that the majority of the elements were formed at the beginning rather than through a series of supernovae explosions.
Given that point, it seems that the stars must be basically the same age.
However, there are many anomalies and there is much evidence of radioisotopic inheritance and mixing because of global tectonic processes having stirred the mantle and added magmas to the crust, which has likewise been stirred by the crustal rock cycle.My thought is, can the relative natural abundances of these chains' terminal products (Pb208,207, and 206) be used to calculate an initial abundance and time frame for the original atomic abundances of the parent isotopes which could be compared to the predictions of Willie Fowler regarding stellar nucleogenesis processes. Thanks again for all your interesting and informative web postings and work.Setterfield: I believe that it is possible to determine the initial ratios of the parent elements in the various chains.Interestingly, using these sorts of ratios, one piece of moon rock dated as being 8.2 billion years old, to the amazement of the dating laboratory involved.As far as stars are concerned, the Th/Nd ratio has been shown to be unchanged no matter what the age of the star is, which leads one to two conclusions.

It was like an explosion, but brighter and more powerful than any explosion you or I could ever dream of. It was called ‘The Big Bang’ – the time when the Universe was born. It was January 1 on our time scale.
At first, all there was heat and light. But, as the Universe began to cool, clouds of tiny particles called atoms began to form. These were the atoms of hydrogen – the main component of water – and helium – the gas we use in party balloons that float on air. Eventually, gravity started compacting these clouds of hydrogen and helium atoms. The temperature at the centre of each cloud grew higher and higher until, suddenly, there was a huge release of energy and Boom! – we had our first stars. Billions of them across the Universe. On our calendar, we are in mid-January.
Now, stars are like people; they are born and eventually die. When very large stars die and explode, they are called supernovae. They become so hot and their gravity so strong that the helium and hydrogen atoms are actually squeezed into new kinds of atoms like oxygen, iron, carbon and even gold. If you are wearing gold jewelry, the gold was made in a supernova explosion. So were all the other atoms in your body except hydrogen. These atoms include the calcium in your bones, the iron in your blood and the oxygen that binds with hydrogen to create the water that you drink.
Take a moment to think about what I just said. These old stars were actually our ancestors. They had to exist so that we could be here. We are made of their dust – stardust! Doesn’t knowing this make you feel like the Universe is a more wonderful place to live in?
Now, with all these different kinds of atoms swirling around younger stars like our Sun, they eventually combined to form asteroids, comets and planets. This is how our solar system and our Earth were formed four and a half billion years ago. On our time scale, we’ve jumped all the way to early September.
As the new planet Earth began to cool, rain fell for the first time and gathered into oceans. Beneath these oceans, at cracks in the ocean floor, heat seeped up from inside the Earth. New chemical reactions began to take place and atoms combined in all sorts of new ways.

For example, Uranium-238 has a half-life of about 4.5 billion years — the age of the earth — while Helium-5 has a half-life of only 10-21 seconds, roughly the time it takes to transition from never having heard of an Ikea product, to desperately needing it.
The relative absence of radioactive materials in the world around us is due, not to non-radioactive material being “more natural” than radioactive material, but rather to survivorship. Radioactive materials have decayed into non-radioactive ones — our (mostly) non-radioactive world is what’s left after everything else has decayed.
The next post will look at decays more closely, especially with regard to their health effects.
- Hyperphysics section on nuclear physics.
- Richard Muller’s fantastic lectures “Physics for Future Presidents,” available on YouTube: Radioactivity 1, Radioactivity 2, Nukes 1, Nukes 2 & Review.
- David Bodansky, “Nuclear Energy: Principles, Practices and Prospects.” 2004, Springer.

Our Moon is at least 4.51 billion years old: study
- Moon is at least 4.51 billion years old — up to 140 million years older than previously thought, according to new study of minerals called zircons brought back from the lunar body to the Earth by the Apollo 14 mission in 1971.
- The Moon’s age has been a hotly debated topic.
- The Moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia.
- The new study would mean that Moon formed “only” about 60 million years after the birth of solar system, providing critical information for astronomers and planetary scientists who seek to understand the early evolution of the Earth and our solar system.
- It is usually difficult to determine the age of Moon rocks because most of them contain a patchwork of fragments of multiple other rocks.
- Zircons are nature’s best clocks. They are the best mineral in preserving geological history and revealing where they originated.
- The Earth’s collision with Theia created a liquefied Moon, which then solidified. Scientists believe most of the Moon’s surface was covered with magma right after its formation.
- The uranium-lead measurements reveal when the zircons first appeared in the Moon’s initial magma ocean, which later cooled down and formed the Moon’s mantle and crust; the lutetium-hafnium measurements reveal when its magma formed, which happened earlier.

I believe our future depends on how well we know this Cosmos in which we float like a mote of dust in the morning sky.
In the image, green corresponds to hydrogen, blue to oxygen, and red to sulfur—three of the 92 naturally occurring elements that space has bequeathed to us. Remember most of the massive elements are formed in stars. Nature is not outside us. Pathologists are the medical specialists who diagnose diseases and their causes. Christmas is coming, and since you are a dear friend, I can send you palm fronds for clothing and perhaps some bamboo to construct a coffee machine. It is an amazing story, isn't it? The muscle cells of the heart, an organ we consider to be very permanent, typically continue to function for more than a decade.
D The main-sequence star probably is a pulsating variable star and therefore appears to be less massive than it really is. Other heavy elements are present in smaller quantities in the body, but are nonetheless just as vital to proper functioning. As we learn in high school chemistry—and can remind ourselves with a quick glance at the —hydrogen, the lightest element, has one proton in its nucleus and thus is given the atomic number 1. We get an animated vignette with the story of Giordano Bruno, a Dominican friar who had visions of an infinite universe but was tortured and killed during the inquisitions of the 1500s. Relatively young stars like our Sun convert hydrogen to produce helium, just like the first stars of our universe. This update comes at a perfect time when we need to be reminded of the wonders of the cosmos and inspired to continue exploring our place on the earth and in the universe. Stars are like nuclear reactors.

While seeking knowledge about the universe and how it works, modern astronomy and physics have repeatedly come face-to-face with a number of age-old questions long thought to be solely within the domain of religion or philosophy. The nature of the chemical evolution of the universe is such a case. Theory and observation indicate that the universe was created in a “Big Bang” some 13.7 billion years ago. As a result of both observation and theoretical work, scientists now know that the only chemical elements found in substantial amounts in the early universe were the lightest elements: hydrogen and helium, plus tiny amounts of lithium, beryllium, and boron. Yet we live on a planet with a central core consisting mostly of very heavy elements such as iron and nickel, surrounded by outer layers made up of rocks containing large amounts of silicon and various other elements, all heavier than the original elements. Our bodies are built of carbon, nitrogen, oxygen, calcium, phosphorus, and a host of other chemical elements—again all heavier than hydrogen and (a) Moving outward through the universe at the speed of light, going around Earth is like a snap of your fingers,… Earth’s circumference 1/ 7 second (b) 1.25 seconds Earth Moon …the Moon is a little more than a second away,… Times shown are light-travel times. (c) 8.3 minutes Earth Sun …the Sun’s distance is like a quick meal,… Because of the vast distances in the universe, we’re not showing objects to scale here: they’d be much too small! (d) Neptune …and the diameter of the Solar System, based on the orbit of the most distant planet, Neptune, is a night’s sleep. Sun 8.3 hours (e) Sun 4.2 years Proxima Centauri, the closest star to our Sun The distance to the nearest star is like the time between leap years,… (f) Earth’s Sun Milky Way Galaxy …the diameter of the galaxy is like the age of our species,… 100,000 years (g) Milky Way Galaxy 2.5 million years Andromeda Galaxy …and the distance between galaxies is like the time since our earliest human ancestors walked on Earth. (h) 13.7 billion years Radius of the observable universe The size of the observable universe is like three times the age of Earth.

"It's surprising that one could develop a clock that reliably keeps time across the human anatomy," he admitted. "My approach really compared apples and oranges, or in this case, very different parts of the body: the brain, heart, lungs, liver, kidney and cartilage."
While most samples' biological ages matched their chronological ages, others diverged significantly. For example, Horvath discovered that a woman's breast tissue ages faster than the rest of her body.
"Healthy breast tissue is about two to three years older than the rest of a woman's body," said Horvath. "If a woman has breast cancer, the healthy tissue next to the tumor is an average of 12 years older than the rest of her body."
The results may explain why breast cancer is the most common cancer in women. Given that the clock ranked tumor tissue an average of 36 years older than healthy tissue, it could also explain why age is a major risk factor for many cancers in both genders.
Horvath next looked at pluripotent stem cells, adult cells that have been reprogrammed to an embryonic stem celllike state, enabling them to form any type of cell in the body and continue dividing indefinitely.
"My research shows that all stem cells are newborns," he said. "More importantly, the process of transforming a person's cells into pluripotent stem cells resets the cells' clock to zero."
In principle, the discovery proves that scientists can rewind the body's biological clock and restore it to zero.
"The big question is whether the biological clock controls a process that leads to aging," Horvath said. "If so, the clock will become an important biomarker for studying new therapeutic approaches to keeping us young."
Finally, Horvath discovered that the clock's rate speeds up or slows down depending on a person's age.
"The clock's ticking rate isn't constant," he explained. "It ticks much faster when we're born and growing
|Contact: Elaine Schmidt|
University of California - Los Angeles Health Sciences

6 billion years before the parent is a naturally occurring radioactive elements spontaneously decay is our first list at the earth.

Although scientists make it in the lab by bombarding berkelium (97) with neutrons, trace amounts of this very rare element are found naturally in rich uranium deposits.
When I was in high school studying chemistry, the periodic table of elements ended at Lawrencium (103). At present there are 118 elements, the most recent one created in the lab being ununoctium (you-nah-NOC-tee-um). Matter of fact, all the elements beyond 98 are artificial, brought to life in nuclear reactors or in particle accelerator experiments. They live very short lives. With so many positively-charged protons pushing against one another in their nuclei, these elements quickly break apart into simpler ones in a process called radioactive decay.
Back at the time of the Big Bang, when the universe sprang into existence, only the simplest elements – hydrogen, helium and trace amounts of lithium – were cooked up. You can’t build a planet from such fluffy stuff. It took the first generation of stars, which formed from these basic building blocks, to synthesize more complicated elements like carbon, oxygen, sulfur and the like via nuclear fusion in their cores.
When the stars exploded as supernovae, not only were these brand new elements blasted into space, but the enormous heat and pressure during the blast built even heavier elements like gold, copper, mercury and lead. All became incorporated in a second generation of stars. And a third.
The 2% of star-made elements, which include carbon, oxygen, nitrogen and silicon among others, went to build the planets and later became essential for life. We’re made of highly processed material you and I. The atoms of our beings have been in and out of the cores of several generations of stars. Think about this good and hard and you might just get in touch with your own “inner star”.
Let’s reframe the question about exotic materials in space not present on Earth. Instead of elements, if we look at compounds, we hit paydirt. A compound is also a pure substance but consists of two or more chemical elements joined together. Familiar compounds include water (two hydrogens joined to one oxygen) and salt (one sodium and one chlorine).
Astronomers have found about 220 compounds or molecules in outer space many of them with siblings on Earth but some alien.

In 1953, the man known during his lifetime only as H.M. underwent neurosurgery to cure his severe epilepsy. The operation inadvertently destroyed most of his hippocampus, a brain structure nobody realized at the time was crucial to the formation of memories. From the age of 27 until his death in 2008, at 82, Henry Molaison—whose name was eventually revealed—could essentially learn nothing new at all.
No responsible person would perform that sort of surgery today, just as no responsible nation would conduct an open-air nuclear test. But the two situations, it turns out, are weirdly related. A commentary in the latest Science, based on a recent study in Cell, explains how nuclear bomb tests provide clear evidence that the hippocampus constantly generates new neurons throughout life. “At the behavioral level,” writes author Gerd Kempermann, of the Technical University of Dresden, Germany, “adult neurogenesis adds a particular type of cognitive flexibility to the hippocampus.”
Exactly what form that flexibility takes is unclear, but the fact that it was uncovered by nuclear testing is intriguing enough. It turns out — unsurprisingly — that the growth of new cells, whether in the brain or anyone else, requires carbon: the element is a fundamental building block of the proteins that make up DNA. That carbon comes from the food we eat, and the carbon in food comes, ultimately, from the atmosphere: it’s taken in by plants as they grow, and we either consume the plants themselves or the animals that eat them.
During the era of widespread open-air nuclear tests, from 1945 to 1963, levels of radioactive carbon-14 in the atmosphere, which are always present at low levels, increased significantly. That carbon worked its way into plants and up the food chain, and ultimately (and harmlessly) into our bodies.
But since the carbon is radioactive, it decays at a well-known rate. That’s how scientists date organic matter — ancient wood or ash, for example — from archeological sites. So if new brain cells were forming during the era of open-air nukes, you should be able to see the spike of C14, suitably decayed for the moment the cells were born, in their DNA. And if the C14 level corresponds to a time when the person was an adult, you know that cells are regenerating and you can even determine how prodigiously.

The idea of using chemical isotopes to combat ageing may be new, but nature may already be onto that strategy as a way of protecting us against free-radical attack, thought to be a key cause of ageing. Babies and mice are born with much more of the isotope carbon-13 in their bodies than their mothers, and women appear to become unusually depleted in carbon-13 around the time they give birth. Both findings suggest that there is active transfer of carbon-13 from mother to fetus.One possible reason for this, suggests Mikhail Shchepinov, chief scientific officer of the biotechnology company Retrotope, which is investigating the use of isotopes to slow ageing, is that the growing fetus selectively builds carbon-13 into its proteins, DNA and other biomolecules to take advantage of the way that heavy isotopes make these molecules more resistant to free-radical attack.It would make good evolutionary sense, as many of the proteins and DNA molecules formed early on have to last a lifetime. "Every single atom in the DNA of the brain of a 100-year-old man is the same atom as when he was 15 years old," says Shchepinov ( BioEssays, vol 29, p 1247 ).
ISOTOPICALLY MODIFIED COMPOUNDS AND THEIR USE AS FOOD SUPPLEMENTS
Classification: - international: A23L1/29; A23L1/30; A23L1/305; A23L1/29; A23L1/30; A23L1/305
Abstract --- A nutrient composition comprises an essential nutrient in which at least one exchangeable H atom is 2H and/or at least one C atom is 13C. The nutrient is thus protected from, inter alia, reactive oxygen species.
THERAPIES FOR CANCER USING ISOTOPICALLY SUBSTITUTED LYSINE
 Lysyl oxidases (LOX, LOXL, LOXL2, etc.; amine oxidase family) are Cu-dependent enzymes that oxidize lysine into allysine (a-aminoadipic-d-semialdehyde) [Kagan H M. et al., J. Cell. Biochem. 2003; 88:660]. LOX have been implicated in crosslink formation in stromal collagens and elastins.

"Everyone thought it must be due to experimental mistakes, because we're all brought up to believe that decay rates are constant," Peter Sturrock, Stanford professor emeritus of applied physics, commented on the issue.
There was more to the issue than instrumental error. Jenkins, Fischbach and their colleagues proceeded to publish papers on the variations in radiometric decay rates in journals like Astroparticle Physics, Nuclear Instruments and Methods in Physics Research. They argued that the variations were not caused by weaknesses in their detection systems, but were actual variations in the decay rates themselves.
Radioisotope Dating 101:
While radiometric dating sounds like a jazzy way to find a mate, it's actually about unruly isotopes.
The world around us is made up of atoms, each with a specific number of positively charged protons, negatively charged electrons, and neutral proton-sized neutrons in their nuclei. Neutrons and electrons are important, but it is the proton number that defines an element. All carbon atoms have six protons, iron atoms have 26, and platinum atoms have 78. If a sodium atom loses an electron, it's still sodium, it's just a positively-charged sodium ion, ready to ionically bond with a negatively charged chlorine ion to make table salt for mashed potatoes. If iron loses electrons, it starts to rust, but it's still iron.
If carbon gains an extra neutron, it still behaves like carbon. Carbon generally has six neutrons with its six protons, giving an atomic weight of 12. Adding one neutron makes carbon-13, a stable isotope that makes up about 1.1% of the carbon on Earth.
Not all isotopes are stable, though. In a crowd of one trillion carbon atoms, one can always find a single unstable carbon-14 isotope sipping on the punch. Over the course of about 5730 years, half of a sample of C-14 will decay into nitrogen-14. A scientist can take a carbon sample, measure the amount of C-14 among its trillions of C-12 atoms, measure the N-14 in the mix, and put together a ratio of the two isotopes. C-14 has a half-life of 5730 years – the amount of time it takes half a sample to decay.

A fist big question…
Sodium is Na (Latin Natrium), Potassium is K (Latin Kalium) Iron is Fe (Latin Ferrum, Italian Ferro) Nitrogen is N (Italian Azoto) Copper is Cu (Italian Rame) Tin is Sn (Latin Stannum, Italian Stagno) Lead is Pb (Latin Plumbum, Italian Piombo) Mercury is Hg (Latin Hydrargyrium) Pay attention to “false friends”: Carbon is C and not Ca (Calcium) Silicon is Si (Italian Silicio, not silicone, a family of polymers…) Phosphor is P (Italian Fosforo)
1 H 1 4 He 2
71 27 1.8 0.2
C,N,O,Ne Tutti gli altri
Tutti gli altri 0,2%
He 27,0% H He
Chemical composition of the Universe
C,N,O,Ne Tutti gli altri H 71,0%
Composi tion of the earth crust
Composition of the earth crust 99,5 % of the earth crust is given by 12 elements, not comprising C and N, on which is based the organic chemistry and biochemical compounds 99,95 % is given by 24 elements All others (ca. 68) are 0.05%
Masses for a body about 70 kg
Composition of the human body
ATOM: smallest portion of an element still having the same properties. From the Greek â€œatomosâ€?: not cleavable
Indeed: cleaved under very energetic conditions, typical of nuclear reactions!
Atoms are the basic unit forming the substances, the elementary bricks of matter. Each ELEMENT gives rise to distinct atoms. About 90 elements are natural and about 19 artificial, to a total of about 109 elements, i.e. to about 109 different types of atoms Isolated atoms are spherical and very small. Typical dimension of atoms: 10 -10 meter (1 Ă…, Angstrom ) or 0.1 nanometres or 100 picometers. Chemists use Angstroms!!

How Old Is the Universe?
The exact age of our universe is one of the biggest mysteries—if not THE biggest—that we can imagine. The question has occupied philosophers and scientists for millennia, but only in the last handful of centuries have we had the tools to hunt for the answer.
How Old Is the Universe? by David A. Weintraub, a professor of astronomy at Vanderbilt University, presents a bracing, detailed, and surprisingly math-free look at how astronomers have managed to figure out that the universe is around 13.7 billion years old.
Not surprisingly, the journey to that answer parallels the history of modern astronomy itself. How do we determine the ages of things? It helps to start with those closest to us—our own planet, our moon, our solar system—and work our way outward from there.
Based on radioisotope dating of rocks (from Earth, the moon, and meteorites), we’ve learned the Earth is around 4.5 billion years old. That jives with the apparent age of our Sun, based on what we know about nuclear fusion, the reaction that powers stars and creates heavier elements out of hydrogen.
From there, we can start looking at other stars. Mr. Weintraub leads readers into a look at how astronomers use the light from stars to figure out how far away they are—which affects how bright they appear—and from that, their age and stellar life cycles in general. White dwarf stars, the coolest and faintest stars we can see, are some of the oldest objects in space. Astronomers clock them at around 12.5–14 billions years old. But in the early 20th century, a surprising discovery changed even that yardstick.
Astronomer Edwin Hubble published data that showed the universe was expanding; not only that, but the fuzzy stars scientists had been calling “nebulae” were actually agglomerations of billions of stars themselves: galaxies. Unsurprisingly, this raised even more questions about the universe’s age and its origins.
From measuring distances to various galaxies, astronomers have come up with an age of 13.7 billion years—but the more recent discovery of the existence of mysterious dark matter and dark energy have raised even more questions.

All artificially derived elements are radioactive with short half-lives, so if any atoms of these elements were present at the formation of Earth they are extremely likely to have already decayed.
Lists of the elements by name, by symbol, by atomic number, by density, by melting point, and by boiling point as well as Ionization energies of the elements are available. The most convenient presentation of the elements is in the periodic table, which groups elements with similar chemical properties together.
The atomic number of an element, Z, is equal to the number of protons which defines the element. For example, all carbon atoms contain 6 protons in their nucleus, so for carbon Z=6. These atoms may have different amounts of neutrons, and are known as isotopes of the element. The atomic mass of an element, A, is measured in unified atomic mass units (u) is the average mass of all the atoms of the element in an environment of interest (usually the earth's crust and atmosphere). Since electrons are of negligible mass, and neutrons are barely more than the mass of the proton, this usually corresponds to the sum of the protons and neutrons in the nucleus of the most abundant isotope, though this is not always the case (notably chlorine, which is about three-quarters 35Cl and a quarter 37Cl).
The atomic masses that are given on the periodic table are actually the relative atomic masses, which are calculated by the following method. As an example, assume there exists three isotopes of element X and their respective atomic masses are 10, 20 and 30 AMU for sake of demonstration. Now also assume that 50% of the isotopes of element X are the 10 AMU version and the two heavier isotopes each account for 25% of the total number of atoms (particles) of this hypothetical element. As a result 10 * 0.5 = 5 AMU and 20 * 0.25= 5 AMU and 30 * 0.25 = 7.5 AMU. The average atomic mass that results is 17.5 AMU. The reason is because the method to calculate the average mass takes into account the relative abundance of all of the isotopes of an element, which is multiplied against their individual masses.
Some isotopes are radioactive and decay into other elements upon radiating an alpha or beta particle.

The
isotopes of a given element have similar or very closely related chemical properties
but their atomic mass differs.
Potassium (atomic number 19) has several isotopes. Its radioactive isotope
potassium-40 has 19 protons and 21 neutrons in the nucleus (19 protons + 21
neutrons = mass number 40). Atoms of its stable isotopes potassium-39 and potassium-41
contain 19 protons plus 20 and 22 neutrons respectively.
Radioactive isotopes are useful in dating geological materials, because they
convert or decay at a constant, and therefore measurable, rate. An unstable
radioactive isotope, which is the 'parent' of one chemical element, naturally
decays to form a stable nonradioactive isotope, or 'daughter,' of another element
by emitting particles such as protons from the nucleus. The decay from parent
to daughter happens at a constant rate called the half-life. The half-life of
a radioactive isotope is the length of time it takes for exactly one-half of
the parent atoms to decay to daughter atoms. No naturally occurring physical
or chemical conditions on Earth can appreciably change the decay rate of radioactive
isotopes. Precise laboratory measurements of the number of remaining atoms of
the parent and the number of atoms of the daughter result in a ratio that is
used to compute the age of a fossil or rock in years.
Age determinations using radioactive isotopes have reached the point where
they are subject to very small errors of measurement, now usually less than
1%. For example, minerals from a volcanic ash bed in southern Saskatchewan,
Canada, have been dated by three independent isotopic methods (Baadsgaard, et
al., 1993). The potassium/argon method gave an age of 72.5 plus or minus 0.2
million years ago (mya), a possible error of 0.27%; the uranium/lead method
gave an age of 72.4 plus or minus 0.4 mya, a possible error of 0.55%; and the
rubidium/strontium method gave an age of 72.54 plus or minus 0.18 mya, a possible
error of 0.25%. The possible errors in these measurements are well under 1%.

As the Universe expanded and cooled, hydrogen atoms began to form into protons and electrons. As a result, space became increasingly transparent. CMB seen today is light that was released when most of the hydrogen atoms formed and that has been traveling through space for billions of years. By analyzing variations in the intensity of the CMB radiation, astronomers calculate the age of the Universe at 13.72 billion years.
Looking back in time. The deepest image of the Universe recorded by the Hubble Space Telescope shows the faintest objects. Because they are the most distant objects, the image is the equivalent of using a time machine to view the formation of the oldest galaxies. They may have formed fewer than one billion years after the Universe's birth in what cosmologists call the Big Bang.
Source: How Old Is the Universe? by Vanderbilt University astronomy professor David A. Weintraub, published 2010 by Princeton University Press, ISBN: 9780691147314
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Every cell in your body has a little clock ticking away in it, researchers reported on Sunday. And while most of you is aging in a coordinated way, odd anomalies that have the researchers curious: Your heart may be “younger” than the rest of your tissues, and a woman’s breasts are older.
Tumors are the oldest of all, a finding reported in the journal Genome Biology that might help scientists better understand cancer, explain why breast cancer is so common and help researchers find better ways to prevent it.
Less surprising, but intriguing: embryonic stem cells, the body’s master cells, look just like newborns with a biological age of zero.
The new measurements might be useful in the search for drugs or other treatments that can turn back the clock on aging tissue and perhaps treating or preventing diseases of aging, such as heart disease and cancer, says Steve Horvath, a professor of genetics at the David Geffen School of Medicine at UCLA.
“The big question is whether the biological clock controls a process that leads to aging,” Horvath said.
Horvath looked at a genetic process called methylation. It’s a kind of chemical reaction that turns on or off stretches of DNA. All cells have the entire genetic map inside; methylation helps determine which bits of the map the cells use to perform specific functions.
He found a pattern of specific methylation events that could be associated with cellular aging. “Methylation levels either increase with age or they decrease with age,” He says. “I identified 353 of these markers that are located on our DNA. I managed to aggregate their information so they arrive at a very accurate clock."
He’s not sure what each methylation marker does on its own.
“It’s really the aggregate that is making the difference,” Horvath said in a telephone interview. "The whole is more than the sum of its parts.”
He looked at blood and tissue samples from hundreds of people, from unborn babies to someone 101 years old. He looked at tumors from people with 20 different types of cancer, samples of non-cancerous tissue from the same patients and perfectly healthy people.
On average, tumors were 36 years older than the rest of the body, a finding that supports the idea that cancer is a disease in which the biological clock runs amok.
Surprisingly, most people’s hearts look younger than the rest of their bodies, the researchers found. ”That looked one average nine years younger,” Horvath says.

Also, because Earth formed as part of our sun’s family of planets – our solar system – scientists use radiometric dating to determine the ages of extraterrestrial objects, such as meteorites. These are space rocks that once orbited our sun, but later entered Earth’s atmosphere and struck our world’s surface. Likewise, scientists use radiometric dating to determine the ages of moon rocks, obtained by astronauts.
Taken together, these methods give results that suggest an age for our Earth, meteorites, the moon – and by inference our entire solar system – of 4.5 to 4.6 billion years old.
The EarthSky team has a blast bringing you daily updates on your cosmos and world. We love your photos and welcome your news tips. Earth, Space, Human World, Tonight.

Scientists at Stockholm’s Karolinska Institute have proved that the human heart produces new muscle cells throughout normal adult life, raising hope that this regenerative prowess can be harnessed to replace cardiac tissue that had been damaged by heart attacks and other pathological conditions.
Conventional wisdom had been that the heart does not produce new cells and people died with pretty much the same ticker as the one they started out with.
But Jonas Frisen and colleagues determined that up to age 25, the heart replaces about 1% of its cells per year, and it continues doing so, albeit at gradually diminishing rates, through old age.
When it’s all said and done, nearly half the heart’s muscle cells are created during a normal lifetime, the scientists estimated.
The scientists knew that cell turnover rates could be quantified in animals by adding radioactive molecules to cells and observing how quickly the radioactivity disappears.
This can’t be done in humans for ethical reasons, but Frisen reasoned that above-ground nuclear weapons testing, which was done by several countries until 1963, had seeded the atmosphere with carbon-14, and this stuff would find its way into the food chain.
The net result would be that the DNA in the nuclei of all living creatures has been C-14 labeled more or less continually as a byproduct of the nuclear folly.
The C-14 remains in the cell for as long as it survives, but since C-14 levels have diminished since 1963, cellular loads of the stuff in more recently formed cells have also diminished. The amount of C-14 in a particular cell thus indicates when it was formed.
The clever work appears in Science.
Loren Field, a cardiologist at Indiana University, told the New York Times the goal now becomes “to try to tickle the system to enhance (cellular regeneration rates).”

Consider the following:
Which among the following is the correct decreasing order of average percentage of the above elements in Human Body?
Average percentage by mass of the elements in the human body is oxygen (65.0%), carbon (18.0%), hydrogen (10 .0%), nitrogen (3.0%) and calcium (2.0%), phosphorous (1.0%), potassium (0.35%), sulphur (0.25%), sodium (0.15%), chlorine (0.15%), magnesium (0.05%) and iron (0.004%). Besides these, there are also traces of iodine, fluorine, copper, silicon, etc. present.
This question is a part of GKToday's Integrated IAS General Studies Module

- 15 million blood cells are destroyed in the human body every second.
- The pancreas produces Insulin.
- The most sensitive cluster of nerves is at the base of the spine.
- The human body is comprised of 80% water.
- The average human will shed 40 pounds of skin in a lifetime.
- Every year about 98% of the atoms in your body are replaced.
- The human heart creates enough pressure to squirt blood 30 feet (9 m).
- You were born with 300 bones. When you get to be an adult, you have 206.
- Human thighbones are stronger than concrete.
- Every human spent about half an hour as a single cell.
- There are 45 miles (72 km) of nerves in the skin of a human being.
- The average human heart will beat 3,000 million times in its lifetime and pump 48 million gallons of blood.
- Each square inch (2.5 cm) of human skin consists of 20 feet (6 m) of blood vessels.
- During a 24-hour period, the average human will breathe 23,040 times.
- Human blood travels 60,000 miles (96,540 km) per day on its journey through the body.
- The average brain uses the equivalent of 20 watts of power
- The average power consumption of a typical adult is about 100 Watt - "Body, Physics of." Macmillan Encyclopedia of Physics. New York: Macmillan, 1996.
Power of a Human Brain - "The human brain is only 2% of the weight of the body, but it consumes about 20% of the total energy in the body at rest."
5 Surprising Facts About the Human Brain
Human Brain Facts and Answers
How IBM is making computers more like your brain. For real | Cutting Edge - CNET News - October 17, 2013; Our brain is a volumetric, dense, object.
Matter, Mind, Life.
Proprioception - Wikipedia, the free encyclopedia - "one's own perception" - sense of the relative position of neighboring parts of the body and strength of effort being employed in movement.
The cerebellum is largely responsible for coordinating the unconscious aspects of proprioception.
Neurocosmologyworld view that ones view of the universe is restrained by the nervous system's ability to process information
emergent fusion of information at all levels of life.

Most elements exist in different atomic forms that are identical in their chemical properties but differ in the number of neutral particles—i. For a single element, these atoms are called isotopes. Because isotopes differ in mass , their relative abundance can be determined if the masses are separated in a mass spectrometer see below Use of mass spectrometers. Radioactive decay can be observed in the laboratory by either of two means: The particles given off during the decay process are part of a profound fundamental change in the nucleus. To compensate for the loss of mass and energy , the radioactive atom undergoes internal transformation and in most cases simply becomes an atom of a different chemical element. In terms of the numbers of atoms present, it is as if apples changed spontaneously into oranges at a fixed and known rate. In this analogy , the apples would represent radioactive, or parent, atoms, while the oranges would represent the atoms formed, the so-called daughters. Pursuing this analogy further, one would expect that a new basket of apples would have no oranges but that an older one would have many. In fact, one would expect that the ratio of oranges to apples would change in a very specific way over the time elapsed, since the process continues until all the apples are converted. In geochronology the situation is identical.
How do you calculate half life of carbon 14?
Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material. The stable form of carbon is carbon 12 and the radioactive isotope carbon 14 decays over time into nitrogen 14 and other particles. Carbon is naturally in all living organisms and is replenished in the tissues by eating other organisms or by breathing air that contains carbon. At any particular time all living organisms have approximately the same ratio of carbon 12 to carbon 14 in their tissues. When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon Experts can compare the ratio of carbon 12 to carbon 14 in dead material to the ratio when the organism was alive to estimate the date of its death.
Half-life and carbon dating
Love-hungry teenagers and archaeologists agree: But while the difficulties of single life may be intractable, the challenge of determining the age of prehistoric artifacts and fossils is greatly aided by measuring certain radioactive isotopes.

If I think of the proton of an oxygen nucleus as the head of a pin lying on the table in front of me, then the electron revolving around it draws a circle passing through Holland, Germany and Spain (The writer of these lines lives in France). Therefore, if all atoms forming my body came together so close as to touch each other, you would not be able to see me any more. You would actually never be able to see me with the naked eye. I would be as small as a tiny dust particle of the size of a several thousandth of a millimetre.18
At this point, we realise that there is a similarity between the largest and the smallest spaces known in the universe. When we turn our eyes to the stars, there again we see a void similar to that in the atoms. There are voids of billions of kilometres both between the stars and between the galaxies. Yet, in both of these voids, an order that is beyond the understanding of human mind prevails.
Inside the Nucleus: Protons and Neutrons
Until 1932, it was thought that the nucleus only consisted of protons and electrons. It was discovered then that there are not electrons but neutrons in the nucleus besides the protons. (The renowned scientist Chadwick proved in 1932 the existence of neutrons in the nucleus and he was awarded a Noble Prize for his discovery). Mankind was introduced to the real structure of the atom only at such a recent date.
We had mentioned before how small is the nucleus of the atom. The size of a proton that is able to fit in the atomic nucleus is 10-15 metres.
You may think that such a small particle would not have any meaning in one's life. However, these particles that are so small as to be incomprehensible by the human mind form the basis of everything you see around you.
Source of the Diversity in the Universe
There are 109 elements that so far have been identified. The entire universe, our earth, and all animate and inanimate beings are formed by the arrangement of these 109 elements in various combinations. Thus far, we saw that all elements are made up of atoms that are similar to each other, which, in turn are made up of the same particles.

Radiocarbon dating powered by smf 1 1 3
The fraction of the radiation transmitted through the dead skin layer is estimated to be 0.11.
Small amounts of carbon-14 are not easily detected by typical Geiger–Müller (G-M) detectors; it is estimated that G-M detectors will not normally detect contamination of less than about 100,000 disintegrations per minute (0.05 µCi).
Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California.
Its existence had been suggested by Franz Kurie in 1934. The primary natural source of carbon-14 on Earth is cosmic ray action on nitrogen in the atmosphere, and it is therefore a cosmogenic nuclide.
What I want to do in this video is kind of introduce you to the idea of, one, how carbon-14 comes about, and how it gets into all living things. They can also be alpha particles, which is the same thing as a helium nucleus. And they're going to come in, and they're going to bump into things in our atmosphere, and they're actually going to form neutrons. And we'll show a neutron with a lowercase n, and a 1 for its mass number. And what's interesting about this is this is constantly being formed in our atmosphere, not in huge quantities, but in reasonable quantities. Because as soon as you die and you get buried under the ground, there's no way for the carbon-14 to become part of your tissue anymore because you're not eating anything with new carbon-14.
And then either later in this video or in future videos we'll talk about how it's actually used to date things, how we use it actually figure out that that bone is 12,000 years old, or that person died 18,000 years ago, whatever it might be. So let me just draw the surface of the Earth like that. So then you have the Earth's atmosphere right over here. And 78%, the most abundant element in our atmosphere is nitrogen. And we don't write anything, because it has no protons down here. And what's interesting here is once you die, you're not going to get any new carbon-14.

This work would ultimately lead to the development of the atomic bomb but it would also open the door to the creation of man-made elements and an understanding of nuclear decay and ½-life.
Decay in this context is meant to describe the physical and chemical breakdown of an unstable atom by the emitting of one type of particle; ½-life is the time it takes for ½ of the material to decay. These terms can and are equally applicable to other materials such as plastics. One reason for recycling plastics is because the ½-life of many plastics is extremely long and unless the material is biodegradable, unlikely to decay in a land-fill somewhere.
The discovery of the neutron doesn’t mean that the development of the atomic theory is complete. Further work has shown that protons, neutrons, and electrons can be further subdivided. Each step in this process is increasingly more complex. But complexity does not preclude solvability and the work goes on.
At this point, one can see that the postulates first proposed by Dalton are no longer valid as written. The idea that the atom is indivisible has been replaced with the notion that there are some other basic particles which cannot be divided. And physicists are working on that idea as this piece is being written. Perhaps one day there will be an ultimate atomic theory – that is what Democritus was seeking and what Dalton was seeking and what drives the exploration of the world of sub-atomic particles today.
Fortunately, for most chemists, the atomic theory of the proton and neutron in the nucleus and electrons in “clouds” around the nucleus provides a nice working model that explains most, if not all, chemical reactions.
Similarly, the idea of nuclear decay and ½-life become very useful in other areas of science; areas perhaps where the collisions of faith, logic, reason and belief collide.
In the next part of this discussion, I want to look at the measurement of the age of something – “How Old Is Old?”

Chemistry can teach us about the composition of celestial bodies and determine their age.
Scientists, indeed, have found a way to find out which elements are parts of the celestial bodies, and by composition can also get to know their age.
It began with studying the light emitted by burning sodium.
The white-hot solid body gives a continuous seven-color spectrum when its rays are decomposed by a prism. If we pass these rays through sodium vapor, then the spectrum appears to be cut by several black lines. The most noticeable, sodium-specific line cuts the yellow part of the spectrum just where the burning sodium, which casts rays of light through the spectroscope, would give a bright yellow line.
The flame of each element does not give a continuous spectrum, but a discontinuous one, consisting of separate colored bands.
Carefully considering the spectrum of the Sun, stretched in length, they found in it dark lines (Fraunhofer lines), quite exactly coinciding with the lines peculiar to elements
What could this mean other than there is sodium vapor in the solar sphere?
After that, first in the spectrum of the Sun, and then other stars, lines were found that are similar to other terrestrial elements. But in their spectra there are also many such lines that do not correspond to the substances known to us. Some of the scientists even dubbed them in absentia and determined the approximate nature of these extraterrestrial elements by the location of the lines in the spectrum. Such are: helium, corona, nobelium and others. The history of the discovery of helium serves as an excellent proof that such a definition of substances from us at dizzying distances of billions of billions of kilometers is not a simple fantasy, but the greatest achievement of human mind. After it was found by the spectroscope on the Sun, it was found on the Earth. In other words, when a new element was found in terrestrial minerals, its spectral lines coincided with the lines of helium with accuracy. So this was helium! It is found in the waters of some sources, for example, in the Caucasus and the Volga region, and in quantities of 0.000001-0.000002 fraction of volume it is a part of the air.
Celestial bodies are divided according to their spectra into those consisting of hydrogen and other gases, - these are the youngest; then enclosing pairs of metals, - this group is older; and finally, the ones containing carbon are the oldest.

Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material. The stable form of carbon is carbon 12 and the radioactive isotope carbon 14 decays over time into nitrogen 14 and other particles. Carbon is naturally in all living organisms and is replenished in the tissues by eating other organisms or by breathing air that contains carbon. At any particular time all living organisms have approximately the same ratio of carbon 12 to carbon 14 in their tissues. When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon
20.6: The Kinetics of Radioactive Decay and Radiometric Dating
The Kinetics of Radioactive Decay and Radiometric Dating - Chemistry LibreTexts
The following tools can generate any one of the values from the other three in the half-life formula for a substance undergoing decay to decrease by half. Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value. The term is most commonly used in relation to atoms undergoing radioactive decay, but can be used to describe other types of decay, whether exponential or not. One of the most well-known applications of half-life is carbon dating. The half-life of carbon is approximately 5, years, and it can be reliably used to measure dates up to around 50, years ago. The process of carbon dating was developed by William Libby, and is based on the fact that carbon is constantly being made in the atmosphere. It is incorporated into plants through photosynthesis, and then into animals when they consume plants.
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10.4: Radioactive Decay
When we speak of the element Carbon, we most often refer to the most naturally abundant stable isotope 12 C. Although 12 C is definitely essential to life, its unstable sister isotope 14 C has become of extreme importance to the science world.

How old are stars?
Stars are categorised into three groups:-
- Population III – The oldest
- Population II
- Population I – The youngest (Our Sun)
Population III are the oldest stars that are thought to have burned close to the big bang at around 400 Million years afterwards. In the time since recombination (~380,000 years after the Big Bang) until ~400 Million years after the Big Bang there were no stars but lots of gas. This gas was made up of mostly Hydrogen and Helium with a little (teeny tiny) bit of lithium and beryllium. Astronomers call this “metal poor.” After recombination this gas started to collapse and form clumps which eventually grew big enough to start nuclear fusion. These stars would have been absolutely massive with calculations estimating that they would have been 30 – 1000 times the mass of our Sun.
Stars this size would have been very bright, with a 1000 solar mass star being millions of times brighter than the Sun. They would also have burned all their fuel very quickly resulting in a huge explosion that would scatter the stellar material back into the galactic void.
What about population II stars?
Population II stars coalesced from the remains of population III stars and also contain more elements, or “metals”, which results in them being smaller, less luminous and longer lived. Because they are smaller they will also produce more elements through nuclear fusion such as carbon, oxygen etc.
Can we see population II stars today?
Yes, but only the smallest of them. They are found in Globular Clusters and Elliptical galaxies. The larger population II stars will have exhausted their fuel through nuclear fusion far quicker than smaller population II stars and exploded in huge supernovae, sending the stellar material out into the cosmic void.
Okay, so what about population I stars?
Population I stars are the youngest stars to form and will have formed from the planetary nebula left over from larger population II stars which have burn out and exploded. They are generally smaller again than population II stars but contain higher concentrations of “metals”, elements heavier than helium. Our Sun is a population I star and as it contains higher concentrations of metals it formed from the planetary nebula left over from a population II star. This also tells us that earth, the planets and almost everything else in the solar system formed from the same nebula.
Wow, we came from the stars?

Curiosity › Science › Chemistry › [Ask a Geek] Is my great grandmother somehow connected to her table? › Reply To: [Ask a Geek] Is my great grandmother somehow connected to her table?
Right after reading this, I remembered the words of Carl Sagan, “We are made of star stuff.” I thought I could pen down my own version of this answer here.
Let’s make a quick microscopic picture so that we can ease into the macroscopic world.
All things are indeed created by molecules. To be precise, all things are made up of elementary particles like electrons, quarks, and constituent particles like protons and neutrons. The combination of these protons, neutrons and electrons in a stable configuration as an atom creates different elements and compounds. Atoms of these elements and compounds together make different molecules, existing in different phases, influencing and reacting with one another. A beautiful harmony the universe plays!
A human is made up of different kinds of molecules in humongous numbers, forming complex shapes, performing complex chemical reactions, carrying information, replicating, all inside a very sophisticated biological system, which is the result of billions of years of evolution.
A tree is similar to a human. It is equally sophisticated as a human system, and it has its own number of different molecules and compounds orchestrating a different kind of biochemical stuff. When you make a table out of the wood from the trees, you still retain the chemical composition of the wood, except without the ‘life’ part of it.
The chemicals that are so common in wood are carbon, oxygen, hydrogen, and nitrogen. A human body has a similar composition too. We are mostly made up of oxygen, carbon, hydrogen, and nitrogen as well.
Now if we look back the timeline of our solar system, we can understand the origin or source of all these elements around us. Some magnificently violent supernova had bestowed us all the elements necessary to create the sun and the planets and possibly life we know today.
The oxygen atom in our body comes from the atmosphere, which is actually produced by the trees by photosynthesis. The carbon in the trees comes from the environment as well. But we breath out that carbon into the atmosphere in the first place as carbon dioxide. In a grand scale, all these atoms had come from that solar nebula that formed Earth.
When your great grandmother was using the table, she was closer to the table.