The Sun's Energy Source

If nuclear fusion is occuring in the sun, why doesn't it blow up like an H-bomb?

The key to answering this puzzle is in the nature of the collision process that starts the proton-proton chain.

It is so unlikely that two protons will collide in just the right way to produce deuterium that the fusion process proceeds at a very slow controlled rate.

How does it produce enough power to account for the sun's enormous energy output?

• There are so incredibly many protons in the sun that at any given time the small fraction of them participating in the proton-proton chain is still a very large number.
• In fact, as you saw earlier, 100 trillion trillion trillion helium nuclei are being formed in the core every second.
• These helium nuclei are the final product of the proton-proton chain.