It seems there is a gap in the causal chain a bit. The sun is a good place for fusion because it is so hot, but it is so hot because of fusion. What is that extra component needed to start the thing?

Is this correct?

The shear amount of mass that just makes up the sun is enough to cause that much pressure and heat to begin with because of the immense gravity having a role. If the sun were some significant amount less massive, it just wouldn't cut it.

Sounds rather quaint describing the sun using units like "Fahrenheit" and "cords". I guess they were talking about 19th century astronomers, so it makes sense.

>> ^GeeSussFreeK:
It seems there is a gap in the causal chain a bit. The sun is a good place for fusion because it is so hot, but it is so hot because of fusion. What is that extra component needed to start the thing?


Crach course in the origin of the solar system:

The whole solar system started off as just a huge gas cloud, which slowly collapsed in on itself due to gravity. When you compress a gas, the temperature rises as explained by the first law of thermodynamics. Thus, when the gas cloud was compressed enough due to gravity, it became hot and dense enough in the center to start off fusion. The immense radiation caused by the nuclear reactions then blew all the matter around the center outwards in the solar system, revealing the Sun in the center. Lighter elements like hydrogen and helium were blown farther away than heavier stuff like metal and rocks. This is why the small rock planets like Mercury, Venus, Earth and Mars orbit quite close to the Sun, while the big gas giants Jupiter, Saturn, Uranus and Neptune orbit further away.

>> ^Pooterius:
Sounds rather quaint describing the sun using units like "Fahrenheit" and "cords". I guess they were talking about 19th century astronomers, so it makes sense.


I rather think it is because the producers of the program come from a country where they have not yet gone over to the metric system. 19th century astronomers used the CGS system, not Fahrenheit and cords.

This is just way too dumbed down. "Not only is the sun the largest star in our solar system, it's the only one!" WTF

Is this correct?

The shear amount of mass that just makes up the sun is enough to cause that much pressure and heat to begin with because of the immense gravity having a role. If the sun were some significant amount less massive, it just wouldn't cut it.

Yep, that's correct. At the very core there are protons of hydrogen running around and in order for the sun to shine they need to get close enough together to fuse. (this nuclear fusion is the first step in the Proton - Proton chain reaction that converts hydrogen to helium). Since protons are positively charged they repel each other, so you need a lot of gravity to force them together, i.e. bigger sun. (They are repelled by the electromagnetic force and need to get close enough together that the strong nuclear force can take over and fuse them.)

Interestingly enough, the sun still isn't large enough to force them together, but it gets them close enough that quantum tunneling can take effect.

Look this stuff up and get into it. It's very rewarding and you'll be able to explain it to your kids.

Come on, Enzoblue, share with the class about quantum tunneling!

*spacy *fire

Adding video to channels (Fire, Spacy) - requested by ant.