General

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

shackleford — Thu, 29 Nov 2012 03:42:02 GMT

Consumariat:

Living things are adapted to specific range of wavelength of the light (which happens to overlap with the range of the Sun - strange, huh?

Not that strange really. Just natural selection.

Smells like circular reasoning to me!

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Consumariat — Wed, 28 Nov 2012 21:08:20 GMT

Sorry, I was trying to be sarcastic for no reason :)

Haha. Sorry, I considered that maybe you were being sarcastic, but I wasn't sure. The interwebs are rubbish with communicating subtly. Someone needs to invent a sarcasm smilie.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Andris Birkmanis — Wed, 28 Nov 2012 20:18:16 GMT

Sorry, I was trying to be sarcastic for no reason :)

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Consumariat — Wed, 28 Nov 2012 20:07:07 GMT

Living things are adapted to specific range of wavelength of the light (which happens to overlap with the range of the Sun - strange, huh?

Not that strange really. Just natural selection.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

limitgov — Wed, 28 Nov 2012 18:51:16 GMT

"BTW, may I suggest Wikipedia?"

No....no you may not.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Andris Birkmanis — Wed, 28 Nov 2012 17:26:22 GMT

Living things are adapted to specific range of wavelength of the light (which happens to overlap with the range of the Sun - strange, huh?). So yes, any light will do, provided it is in the correct range (e.g., pure red will be probably bad for both plants and sunbathing).

BTW, may I suggest Wikipedia? I heard they have more articles than these humble forums ;)

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

limitgov — Wed, 28 Nov 2012 16:24:42 GMT

so, for some reason, the energy released by hydrogen fusing together is required for plants to live? and helps us make vitamin d?

or will any light do those things?

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Lady Saiga — Tue, 27 Nov 2012 21:43:48 GMT

Our star will not supernova. It is not the right type of star for that. It will become a red giant, then a nebula. Its core will remain the longest, as a white dwarf.

The core of the Sun is by now more than half helium, by the way. The heat it releases is energy, not fire, which transfers slowly up through the various layers and is finally released as photons.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Andris Birkmanis — Tue, 27 Nov 2012 21:23:02 GMT

So, fire is possible without oxygen?

Yes, fluorine is a good example of non-oxygen oxidizer.

But not inside a star, the conditions are too harsh for any chemistry, so to speak.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Anenome — Tue, 27 Nov 2012 20:38:46 GMT

limitgov:

"It's not fire. That's a chemical reaction. The sun is powered by fusion which is a nuclear reaction. Yes, the sun contains enough hydrogen to sustain itself. Consider the volume of the sun and the mass of plasma contained therein."

I see. So, the sun is basically a huge ball of hydrogen? A giant ball, with enough hydrogen to last billions of years?

The sun is a giant ball of mainly hydrogen, yes.

limitgov:
Wouldn't the heat from the fusion, light the hydrogen on fire?

Fire is a chemical reaction known as oxidation, meaning it is the combination of oxygen with something. Oxygen is very reactive, thus why fire is so common.

Fire puts out heat and light, so does the sun, which is why we liken the sun to fire. However, there's no fire in the sun in the sense of oxidation happening. There's very little oxygen.

The main reaction is two hydrogen nuclei ramming together because of gravity and heat and fusing into a helium nucleus. This fusion releases mass amounts of energy, which come to us as heat and light from the sun. Eventually enough helium can get in the core to begin producing lithium, carbon, oxygen, and ultimately iron, in a process known as stellar nucleosynthesis. (Although oxygen is produced, it would never be able to oxidate anything, a star is simply too hot to allow compounds to exist.)

When the star has created large amounts of iron, it starts to hit a wall. Iron is very hard to fuse into heavier elements, and when it does it's apparently an extremely violent reaction.

Eventually, enough iron builds up in the core that the star explodes in a supernova. The resulting explosion, if you can imagine an explosion taking literally years to progress, creates all the heavier elements known to exist.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

limitgov — Tue, 27 Nov 2012 20:03:43 GMT

"That's a big "if", as other oxidizers are possible."

So, fire is possible without oxygen?

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Jon Irenicus — Tue, 27 Nov 2012 19:20:27 GMT

I think it's time the Sun paid its fair share.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Andris Birkmanis — Tue, 27 Nov 2012 17:58:35 GMT

That's a big "if", as other oxidizers are possible.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

Autolykos — Tue, 27 Nov 2012 17:46:54 GMT

If fire requires oxygen by definition, then it follows that fire is impossible without oxygen.

Re: Sun Burns 600 Million Tons of Hydrogen Every Second?

limitgov — Tue, 27 Nov 2012 17:28:38 GMT

"No, not at all. Fire is an oxidation reaction. Where's the oxygen in a huge ball of hydrogen?"

Hmmm. So, there can be zero fire without oxygen?