Having trouble understanding how We are made from a supernova?

[nukeman]

Having trouble understanding how "We" are made from a supernova?

Ok, I may not be understanding this right, so maybe someone can shove me in the right direction.

Without getting into the mechanics of a supernova, we are remnants (carbon and what not) from a supernova, so in a way, the matter we are comprised of is from a star? Is that correct? As per the quote from Neil Tyson "We are in the universe and the universe is in us"

1) If that is correct, can someone maybe tell me in more detail how that is possible?

2) I would think that this earth, and the elements on this earth, including the ones that make up "us", would be from the big bang, not a supernova event ?

Thanks. Sorry if this is a silly question.

 

[fillipeano]

The elements that we are made up of are created from a supernova.

When giant stars run out of hydrogen to fuse in their core, they begin to fuse helium and heavier elements until it hits iron. Since nuclear fusion cannot continue with iron, gravity collapses the star, and all of these elements are spewed out into space in a supernova explosion. From this supernova came about our star, and everything around it (including Earth).
The big bang was an event that lead to the expansion of space, time, and matter. Technically you can say that everything came from the big bang, since that's what started it all. But I don't like being technical all the time (:

Hope that helped!

 

[Arch2008]

About 380,000 years after the Big Bang, the universe had cooled enough for atoms to form. These atoms were of the elements hydrogen, helium and a little lithium. Huge stars formed from these elements. The heat a star produces fuses lighter elements into heavier ones, like silicon, oxygen and carbon. Finally, when the core fuses to nickel, the nickel rapidly decays to iron and the fusion stops. The outer layers collapse onto the core and reverberate, tearing the star apart. The heat of this explosion fuses the rest of the elements we know. These travel through space until they coalesce into planets and other things, like us.

 

[Ken G]

2) I would think that this earth, and the elements on this earth, including the ones that make up "us", would be from the big bang, not a supernova event ?

What you may be missing is called the "5/8 bottleneck," which is that by the vagaries of nuclear physics, there are no stable nuclei with 5 or 8 nucleons (protons and neutrons). That might not seem like a big deal, but the Big Bang is very good at making hydrogen (1 nucleon) and helium (4 nucleons), but to get other things, it needs to bash these together and fuse into either 5 or 8 nucleons. Since such nuclei fall apart right away, the Big Bang doesn't get any further (there's a very little lithium with 7 nucleons and berillium with 9, but not enough to do anything with).

So how do stars get past the 5/8 bottleneck and give us everything else? The solution that stars find, that the Big Bang does not, is super high densities in their cores. The Big Bang has high density too, at some point, but the temperature is too high when the densities are that large, and the nuclei get shattered by super-high energy collisions at those temperatures. In stars, the density can be high at a much more conducive temperature for fusing heavy elements, say a few hundred million K. High density gets past the bottleneck by allowing collisions of 3 nuclei all at once, so before the binary collisions fall apart, the third nucleus comes in and let's you get something stable, particularly 3 He -> C (the "triple alpha" process). That's why stars make carbon, and oxygen, and everything else too.

By the way, carbon is not just made in supernovae. Low-mass stars are much more prevalent in number than the high-mass stars that go supernova, and low-mass stars evolve into a phase called an "asymptotic red giant". In this phase, the stars loses a bunch of mass, and some of the carbon that the star fused gets included in the wind. I believe that's quite an important source of carbon, but the exact amount is not known.

 

[nukeman]

Great, thanks so much for all the info!

 

[Radrook]

Hydrogen from which the first generation-stars formed emerged during the particle and coalesence stages of universal evolution and not from from supernovas. These first generation stars provided the material for the formation of second generation stars by going supernova.

 

[Nik_2213]

If I've understood the wiki on Metallicity... (YMMV)
http://en.wikipedia.org/wiki/Metallicity
...then we're third-generation star stuff.

 

[94JZA80]

it should be noted, based on the title of your thread, that we, human beings, are not specifically made from supernovas. while supernovas do create many heavy elements, the majority of stuff we're mad of wasn't created in them. rather carbon, hydrogen, oxygen, and the various other elements that compose a majority of the molecules that compose us humans were made inside of stars before they actually went supernova. we are more so remnants of the thermonuclear fusion that occurred during stars' lifetimes much more than we are remnants of the thermonuclear fusion that occurred during their deaths. that being said, the lighter elements produced during a star's lifetime would not be spread about the universe were it not for supernovae.

 

[Arvid]

That great as far as it goes. What I don't understand is how these various elements get into biological beings. Is carbon gathered while the cells are dividing during pregnancy? We shed skin and replace skin cells constantly, do these cells receive elements from the "ether"?

biologically challenged physics minor, so keep it simple, please.

 

[marcus]

That great as far as it goes. What I don't understand is how these various elements get into biological beings. Is carbon gathered while the cells are dividing during pregnancy? We shed skin and replace skin cells constantly, do these cells receive elements from the "ether"?

biologically challenged physics minor, so keep it simple, please.

How are you on picturing a "carbon cycle"? Carbon atoms keep getting recycled. For example some wood burns, or decays, or gets eaten by a termite and metabolized---and the end result of that is a C atom goes into the atmosphere as CO2.

Then a plant absorbs the CO2 and some water and with the help of sunlight it strips off the Oxygen and combines the C with some H (from the water) to produce a carbohydrate, like sugar or cellulose, or a hydrocarbon, like olive oil.

And maybe you take some of those plant leaves and make a salad and metabolize the carbon and breathe it out as CO2 into the air again. Or some other animal or fungus or bacterium does the job.

So all the carbon atoms in the biosphere have been recycled innumerable times, basically with the help of sunlight and water, through green plants and algae.
===============================

Sure, they originally came from the core of some star, but that was a long time ago. They had to be cooked in a star, out of hydrogen. Because the big bang did not make carbon---and other heavier elements like that. So some star had to make the carbon out of hydrogen by fusion. And then the star had to explode. And the gas and dust had to re-condense into stars again, and they had to cook the stuff some more. This had to happen several times before you could have planets condensing with a good assortment of chemical elements.

But that was a long time ago. The atoms in us, the vast majority of them anyway, did not come directly from a star---they've been here on Earth for ages, going thru many many chemical cycles. And geological cycles.

I was puzzled by your question, and thought it was remotely possible you knew all this already and were just asking in a playful spirit (about getting carbon from the "ether") but decided to give a straight answer just in case there was some sincere confusion.

 

[Arvid]

Thanks for your reply. OK, the carbon cycle is clear, but I must not breathe out all of the ingested C as my cells are made up of C. Does a C atom get moved to a newly created cell? Once a baby is born it must ingest enormous numbers of carbon atoms to grow so much. All of the elements needed for development and later for cell replacement must be ingested. Then where are the missing C atoms. The life on the planet has increased 100s fold over the last 4.5 billion years. I really can't quite put it together. When a plant decays is all the sequestered C returned to the environment? Does a tree provide a zero net decrease in carbon once it has decayed? Are we dealing with a fixed number of C atoms? How do we have increased amounts of CO2, global warming, if the number of carbon atoms is essentially fixed. I can't image that the planet receives much in the way of a percent increase from space on a daily basis.

 

[Drakkith]

Thanks for your reply. OK, the carbon cycle is clear, but I must not breathe out all of the ingested C as my cells are made up of C. Does a C atom get moved to a newly created cell? Once a baby is born it must ingest enormous numbers of carbon atoms to grow so much. All of the elements needed for development and later for cell replacement must be ingested. Then where are the missing C atoms. The life on the planet has increased 100s fold over the last 4.5 billion years. I really can't quite put it together. When a plant decays is all the sequestered C returned to the environment? Does a tree provide a zero net decrease in carbon once it has decayed? Are we dealing with a fixed number of C atoms? How do we have increased amounts of CO2, global warming, if the number of carbon atoms is essentially fixed. I can't image that the planet receives much in the way of a percent increase from space on a daily basis.

When something dies it's atoms are recycled into the environment to be used again. All of the carbon atoms that were here 4 billion years ago are still here today. There are no more and no fewer of them. (Other than extremely tiny amounts from meteorites and such over the years)

Burning fossil fuels increases CO2 in the atmosphere by bonding the carbon in the fuel with oxygen in the atmosphere. There is only a finite amount of fossil fuels in the Earth, and every time we burn some it is permanently gone.

 

[PatrickPowers]

Thanks for your reply. OK, the carbon cycle is clear, but I must not breathe out all of the ingested C as my cells are made up of C. Does a C atom get moved to a newly created cell? Once a baby is born it must ingest enormous numbers of carbon atoms to grow so much. All of the elements needed for development and later for cell replacement must be ingested. Then where are the missing C atoms. The life on the planet has increased 100s fold over the last 4.5 billion years. I really can't quite put it together. When a plant decays is all the sequestered C returned to the environment? Does a tree provide a zero net decrease in carbon once it has decayed? Are we dealing with a fixed number of C atoms? How do we have increased amounts of CO2, global warming, if the number of carbon atoms is essentially fixed. I can't image that the planet receives much in the way of a percent increase from space on a daily basis.

When a plant decays is all the sequestered C returned to the environment? Does a tree provide a zero net decrease in carbon once it has decayed? Are we dealing with a fixed number of C atoms?

Yes yes yes. The C in the ecosystem is increasing due to the burning of hydrocarbons from the interior of the earth.