Astronomy 1021 Lecture Notes - Lecture 24: Cyanoacrylate, Nuclear Fission, Nuclear Reaction

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

The sun is an amazing source of power: the su(cid:374)"s total po(cid:449)er output called luminosity is huge, about 3. 8 x. 1026 watts: in perspective, if we could so(cid:373)eho(cid:449) (cid:272)apture a(cid:374)d store 2 se(cid:272)o(cid:374)d"s (cid:449)orth of the u(cid:374)"s lu(cid:373)i(cid:374)osit(cid:455), it (cid:272)ould po(cid:449)er us for thousa(cid:374)ds of (cid:455)ears. Science showed the sun would keep shining steadily for about 25 million years, but then we found out the earth is much older than that. Einstein finds the crucial piece of the puzzle: with ei(cid:374)stei(cid:374)"s fa(cid:373)ous e = mc2 formula from 1905 there was some outlook, energy has mass, and lots of it. And there is plenty stored in atoms: suppose you could somehow convert 1 kg of matter completely into energy in about a second, then you would generate about 100,000 trillion (1027) watts. E=mc2 contains the answer: 1 helium nucleus is lighter than 4 hydrogens, (cid:449)ith ei(cid:374)stei(cid:374)"s fa(cid:373)ous for(cid:373)ula, it (cid:271)e(cid:272)a(cid:373)e (cid:272)lear that i(cid:374) pri(cid:374)(cid:272)iple, the.