ASTRON 2B03 Lecture Notes - Gravitational Redshift, Schwarzschild Radius, Supernova Remnant
25 Sep 2013
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Document Summary
Low mass stars fusion stops when a carbon core is formed. High-mass stars can fuse elements up to iron. End product: neutron star or black hole. Pressure (coming from nuclear reactions) outwards, stabilizing with equal amount of gravity coming in. If pressure outweighs gravity, star gets bigger. All heavy elements came from supernovae (gold, lead). If you squeezed earth into a tiny volume (1cm) -> the escape velocity would be greater than the speed of light and would result in a black hole. All the different escape velocities -> none close to the speed of light. Every object has a critical value under which it becomes a black hole -> the schwarzschild radius. We call it a surface but its more like a barrier: nothing within the s radius can ever come out. Singularity a point of infinite density. Anything that falls in doesn"t come back in. Gravitational force changes as you go inside a spherical object.
