Where Does The Sun Get Its Energy?

The sun has been producing light for about five billion years but where does all its energy come from? The most common idea is that the sun is burning gas - like a giant fireball in the sky. If this were true, the sun would have gone out long ago. So how is the sun actually fuelling itself? It is converting its own mass into energy. By combining protons (the nucleus of hydrogen) into helium, it squeezes some mass into energy - 4.3 billion kg per second. It is Einstein's famous E=mc^2 which gives us the quantitative relationship between mass and energy, where c is the speed of light.

[TheGreatRakatan]

I feel really bad for Derek. In all of these videos he's trying to educate people, but his comment section is just a bunch of people claiming to know things while simultaneously insulting people who don't. 

It is usually these same people who never contribute to science because they are so confident in their knowledge that they don't accept the knowledge that they don't have.

[bsettle]

"It's one of those things you think you know, but actually have no idea" - NAILED IT! The entire purpose behind his videos....

[Wankhedewarriors]

Those high-school boys were surely the backbenchers and the bunkers.

[PKAnibbles]

Even after 10 years, still a fantastic video. The fact that Derek did his PhD on how to best explain physics to the masses really shows in this video. Wonderful channel, deserves all the recognition it has.

[veritasium]

Right - the water coming out of the balls represents mass, that was being converted to energy, which would be released in the form of gamma rays, which bounce around inside the sun for a long time being transformed into more photons of longer wavelengths before being radiated from the surface of the sun as mostly visible light.

[skydivekrazy]

You have an excellent way of explaining science. Thank you.

[hansolo]

everyone watching this was probably shouting ''ITS FUSION!''

[doofynetgraouw]

I just loved the idea of merging two balls full of water to illustrate the energy release ! That was brilliant ! This concept is so difficult to get, and anyone got it right just from this illustration. Great job !

[CoPlay]

I'll be the first one to admit that I don't know the answer to most of the video questions/topics he releases, but I find this stuff fascinating. I knew the sun wasn't a big ball of fire, but I didn't know exactly what it was, so that's probably along the lines of the answer I would have given if confronted on the street.

[rtel]

i'm impressed that when those two girls threw the protons at each other they actually connected

[viharcontractor]

Alien : We found life!!
Someone : E equals sun
Alien : Nevermind, Moving on.

[Uiru]

Everyone seems to be Albert Einstein in this comments section.

[utl]

I just watched the video again, and realized that it is a really good video on explaining some beautiful science.

[dax]

These people are really kind of adorable, getting interested in things they don't know. you can't think of them as ignorant, not when they're so curious and thinking so hard.

[sanjeetsinghk]

I love that Derek is doing one simple but awesome thing, he's making people believe that science is cool.

[spacestayshon]

"Is that energy?" "Sick!!" Lol

[abhishiktaganguly]

Thanks a ton! You actually explained a very complicated phenomenon in the easiest possible manner. I never understood how hydrogen atoms could fuse to give helium...but now the entire concept is crystal clear to me..

[LeeMaitland]

I noticed that you didn't mention gravity, the mass of the stuff in the sun is the reason for such strong gravity which fuses the protons and neutrons together, overcoming their repulsion. Granted, what causes the heat and light is fusion, but what causes the fusion is really just mass and gravity. Great video though as always, it's a shame that more people are not engaged in the sciences.

[unifiedcodetheory]

"Some kind of chemical reaction" was actually the most accurate answer out of all of them.

[SureshKumar-bikv]

I love the way in which he explained nuclear is you, Veritasium❤