AST101H1 Lecture Notes - Lecture 10: Neutrino, Photon, Photosphere

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Eryan Apsnler, Michael Reid

Document Summary

E = mc^2 can also work in reverse. Energy can be converted into mass under certain conditions. In a billion years, earth will be uninhabitable due to a 10% increase in the sun"s energy (heat) output. Potential problem: chances of all 4 protons in a hydrogen-helium fusion colliding simultaneously is very slim. 2 hydrogen particles collide simultaneously rather than 4. Fusion only occurs at the sun"s core because the core is the only place hot enough for fusion to occur. Amount of fuel in the sun will sustain the fusion process there for 10 billion years. Such fuel reserves are already halfway depleted. Proton-proton (pp) chain"s proof of existence is the existence of neutrinos. Neutrinos are tiny sub-atomic particles that go through almost anything, travelling at the speed of light. There is an experiment to discover the exact number of neutrinos. Send a 50,000 tonne tank of water 1 km underground. Wait for a flash of light to occur.