AST 2002 Chapter Notes - Chapter 11: Photosphere, Helioseismology, Photon
Document Summary
The sun shines because of energy generated by nuclear fusion. This fusion occurs under the extreme temperatures and densities found deep in the. The sun makes energy by combining, or fusing, two or more small nuclei into a larger one. The 15 (cid:373)illio(cid:374) k plas(cid:373)a i(cid:374) the sola(cid:396) (cid:272)o(cid:396)e is like a (cid:862)soup(cid:863) of hot gas full of (cid:271)a(cid:396)e, positi(cid:448)ely charged atomic nuclei (and negatively charged electrons) whizzing about at extremely high speeds. Some of these nuclei are on high-speed collision courses with each other. Electromagnetic forces usually deflect the nuclei, preventing collisions. If nuclei collide with sufficient energy they can stick together (fuse) to form a heavier nucleus. Strong force- binds protons and neutrons together in atomic nuclei; only force in nature that can overcome the electromagnetic repulsion between two positively charged nuclei. It overpowers the electromagnetic force over very small distances, but is insignificant when the distances between particles exceed the typical sizes of atomic nuclei.
