Astronomy - question about the sun...

[ASC1951]

It burns hydrogen and then helium and so on. You can burn carbon, nitrogen, oxygen, neon and all sorts. It's just our sun isn't very big.

IIRC you need a very big star - a supernova, in fact - to create some of the trace elements in our bodies. I am comforted by the thought that we are entirely generated in the insides of stars and eventually end up there again - reincarnation on a truly epic timescale.

And is it true that all the lithium in our universe was created in the first few seconds after the Big Bang?

 

[dellzeqq]

And is it true that all the lithium in our universe was created in the first few seconds after the Big Bang?

dunno, but if Californians keep on taking the stuff we're going to have to make some more!

 

[Maz]

I'll paraphrase Marinho's reply for you Maz.

You're too stupid to understand

Ain't that a fact!

 

[Camrider]

And is it true that all the lithium in our universe was created in the first few seconds after the Big Bang?

The answer is probably no. Lithium is created in young stars but it is unstable at the high temperatures found in most stars so is subsequently destroyed by collisions with protons creating 2 He atoms in the process. In very cool stars like brown dwarfs lithium is formed and maintained so some new lithium is created but all the lithium available to us on Earth was almost certainly synthesised during the big bang.

 

[swee'pea99]

A friend sent me a very interesting link about this sort of thing, for anyone who finds that sort of thing interesting, after I mentioned someone telling me that if the entire universe was scaled down in proportion to the point where the sun was 1mm across, the next nearest star to us would be 18 miles away.

 

[subaqua]

Yeah, as others have said, the sun isn't burning in the same way as would happen if you lit a flask of hydrogen. It's basically a nuclear fusion reactor with hydrogen as its fuel, which it converts into heavier elements (mostly helium) by fusing hydrogen atoms together. When that happens, there is a bit of energy left over, which is radiated as heat and light. (obviously it's all a bit more complicated than that, but that's the basic idea)

Interestingly, if you had an environment of 100% hydrogen, you wouldn't be able to ignite it, as you need oxygen for that kind of reaction. There's a moon (of Jupiter, I think, but I'm a bit hazy) where the atmosphere is mainly methane, but you wouldn't be able to light it as there is little or no oxygen there.

methane has a limited %age band where combustion in oxygen will take place. above or below this concentration it just wont combust

 

[Maz]

I would love to know more about astronomy, but it's a bit over my head

You need to go to night classes.