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  • So, I live in Montana and it's winter right now and it's cold and in February

  • walk outside and looks like this.

  • And sometimes I just wish that i lived on Mercury, yeah that looks nice.

  • So, the Sun is awesome whatever you're doing right now you're only able to do

  • because of the Sun. Because the Sun gives us its heat, and its light which makes

  • photosynthesis happen, which makes all of the food that you eat. You might as

  • well know how it works. The Sun is really nothing more than a giant massive

  • nuclear explosion that just keeps on exploding, and exploding, exploding,

  • exploding. So, the Sun was formed about 4.5 billion years ago the same way that

  • all other stars form: there was a bunch of gas in the Universe and some of the

  • gas started clumping together because of gravity, the more that that

  • gas clumped together the more gas wanted to be there and come together so hard

  • that eventually two atoms of hydrogen fused together into helium producing

  • huge amount of energy and that started off a chain reaction that became the

  • power of our Sun. So, now at its corewhere all the, you know, real interesting

  • action happensthe temperature there is about 27 million degrees Fahrenheit.

  • From there it takes about a hundred and seventy thousand years for that energy

  • to reach the surface of the Sun. By that time it's cold to a balmy 10,000 degrees.

  • Often you'll hear people say: "They're going to make this as hot as the surface

  • of the Sun", and it's important to note the surface of the Sun not that hot

  • compared to 27 million degrees.

  • Other examples of hydrogen fusion that you're probably familiar with the do not

  • occur on the Sun include the Tsar Bomba: the most powerful nuclear weapon ever

  • detonated. It was detonated in the Soviet Union in 1961, of the way

  • that fusion bombs work. As they actually have basically a bunch of fission bombs

  • going off that wants to create enough pressure to make the hydrogen atoms fuse

  • just the fission bombs that made this our bomb go off was equivalent to 50

  • megatons of TNTthe amount of stuff that was fused in the Tsar Bomba was about... that big.

  • By contrast the area of the Sun where fusion is happening is about the size of

  • 240,000 Earth, so if the Sun were to blow up all at oncelike the Tsar Bomba did

  • it would basically melt everybody's faces off from here to Alpha Centauri. So

  • the Sun and the Tsar Bomba are basically the same thing on different scales.

  • Question is: why doesn't the Sun blow up all at once? Lucky for us, some naturally

  • controls its pressure and its temperature and its fusion rate in the

  • kind of natural thermostat. Basically, when the enormous heat and explosive

  • energy in the corn make it expand, the core becomes less dense which makes the

  • fusion rate slowed down and then gravity pulls the core back in, and starts all

  • over again and that's just the way the Sun rolls.

  • That's not to say that some stars don't blow their water all at once or at least

  • a lot faster. Our Sun happens to be a G-type star, which is a tasteful middle

  • of the road kind of mass for a star. As it happens the less massive star has the

  • dimmer it is the redder it is

  • and the longer lived it is. Team red dwarf, for example, can take trillions of years to burn out.

  • While one of those big, blue O-type stars can burn through its entire allowance of

  • hydrogen and like 1 million years.

  • So, our Sun is doing pretty good. It looks like it's got another 4.5 billion years or so before it

  • you knowsputters out. How good old Sun... I miss it.

  • Thanks for watching and learning during this SciShow dose. If you wanna have

  • more of this you could subscribe at youtube.com/scishow. What else is going on?

  • Oh, yeah, you can hook up as a lot of Facebook and Twitter. If you have any

  • questions or ideas and ,of course, down in the YouTube comments below.

So, I live in Montana and it's winter right now and it's cold and in February

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Sun VS. Atomic Bomb

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    joey joey に公開 2021 年 05 月 11 日
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