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1. how fast does [a black hole] grow?

2. By what means is light unable to escape a black hole?

I've been reading "the edge of space" and I am having some trouble wrapping my brain around the details of the event horizon.

1. how fast does it grow? Is that growth based on the mass already inside the black hole or does it only grow when new matter gets sucked in.

Does light have mass ...

Quote1. how fast does [a black hole] grow?The radius of a black hole is proportional to its mass.If the mass stays the same, the radius stays the same (no growth).If matter and/or energy falls into a black hole, it's mass grows, and its radius grows.Quote2. By what means is light unable to escape a black hole?Similar to the Doppler shift (imagine a fire engine siren passing you on the street), there is a ...sorry, you cannot view external links. To see them, please REGISTER or LOGIN (how fast it spins).The best of our current theories break down at the event horizon - all we can say is what we expect as we approach the event horizon.

As far as I know you won't find a (proper, or rest) mass for light, unless you use a equivalence to mass.

Ok, 'mov' format is it? You wouldn't happen to have a *.pdf discussing it?

Have no problem with light having a momentum Pete, neither with having a energy. It's the idea of rest mass I'm wondering about there.

Seems we might mean the same thing though, which is why I asked if you happened to have a pdf presenting Alan Guth's definition of a mass.

..when it comes to the definition of energy able to generate stuff defined as having a rest mass though?...

Let E represent the total energy and K the kinetic energy of the particle, m0 represent the rest energy E0. Then E0 = m0c2. Then E = K + E0

Quote from: Pete Let E represent the total energy and K the kinetic energy of the particle, m0 represent the rest energy E0. Then E0 = m0c2. Then E = K + E0 The whole quote makes sense, but I’m not clear about the bit I underlined.

Let E represent the total energy and K the kinetic energy of the particle, m_{0} represent the rest mass and E_{0} = m_{0}c^{2} the rest energy.