the fates of collapsed star cores INITIAL MASS

the fates of collapsed star cores? ? ? INITIAL MASS units of solar mass ~>2 DEATH THROES COLLAPSED CORE mass object radius PRESSURE SOURCE red giant, nova < 1. 4 m� white dwarf* earth electron degeneracy white dwarf supernova I ~6000 km a carbon bomb ~>3 massive supernova II 1. 4 -3 m� neutron star** ~20 km neutron degeneracy iron bomb Boston ~10 massive supernova II big bang ~>3 m� black hole radius m Schwarzschild 1 m� 3 km 10 m� 30 km mearth mini black hole 1 cm none *1. 4 m๏ is Chandrasekhar mass, electrons travelling at c **“Landau” mass, neutrons going at c melectron/mneutron = 1/2000 = rneutron star/rwhite dwarf is the density of a black hole infinite?

escape from earth, 11 km/sec (here to Rt. 128 in a sec); from moon, 2. 4 km/sec Escape Velocity from Black Hole = c Initial Kinetic Energy = Final Gravitational Potential Energy ½ mass (velocityescape)2 = G mass M r shrink earth to radius = 1 cm radius (keeping mass the same), light could not escape an earth mass marble shrink our sun to 3 km radius, escape velocity = c… no escape from the BU campus-sized black hole …r is the Schwarzschild radius…the event horizon …cannot know what is inside…info cannot escape

If our Sun shrank to a black hole, we feel nothing…gravity different only near & inside event horizon charges & spin carried in, but otherwise we have no further contact with matter that disappears orbits inside same as outside it, circles, ellipses, hyperbola Black holes don’t suck! only stretch very local space since so small, hardest thing to fall into

tidal forces near event horizon …lethal stretch to humans if ~ < 3 Schwarzschild radii from 3 MSun black hole, 5 km tidal forces gentler near a supermassive black hole …due to much bigger radius

Do black holes last forever? Virtual Particles near a Black Hole Particles pairs produced near black holes… if one member of a virtual pair falls into the black hole energy to transform virtual particle to real particle comes out of black hole’s mass

Hawking Radiation his conjecture: this real particle production would cause black holes to “evaporate” over time only “orphaned” subatomic particles left over