Module 5:
 Nuclear Fusion: heat that is so strong nuclei can merge to form new elements (2 hydrogen’s form
a helium)
o Light in stars is generated by a thermonuclear furnace in the Core
o 15 million K, 100x the density of water, 2 million bar pressure
 Special Relativity: deals with objects moving at very high, but uniform speeds
o Presented by Einstein in 1905
o About inertial reference frames when the relative speed is approaching the speed of light
o Postulate 1: the laws of physics are the same in all inertial reference frames and are the
same everywhere in the universe
 The structure of the Sun: 6 Layers (CCPCRC)
o Corona (1-2Mill K) X-Rays
o Chromosphere (10,000 K) UV Rays
o Photosphere (6,000 K) Sunlight
o Convection Zone (700,00 K)
o Radiation Zone (3.5Mill K)
o Core (15Mill K)
o Sun is comprised of 92% H, 8%He, 0.6% O, and 0.3% C
 Getting Energy out of the Sun: All energy emerges through the Photosphere
o Made through fusion in the Core, photons take 100,000 years or more to reach surface
o Energy comes from converting matter directly into energy through atomic reactions
 Sunspots: often bigger than one or two earths
o Helped scientists discover that the sun was rotating