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Re: Re: Re: Something New To Look For.

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Posted by Alexander on January 24, 2001 23:58:18 UTC

BH=black hole (common in the literature), hf=E - energy of photon with color (frequency) f, hf/c^2 - energy of photon in units of mass. Ef... is a typo, it should be If...

Gravity effects light in the same manner it effects any other motion: bends trajectory down. So near Earth the shape of small part of light beam is parabolic, as a trajectory of any other free-falling object (and whole beam is hyperbolic due to 1/r^2 Newton gravity law far from Earth, so it bends toward Earth passing by). Because when light falls down it can not accelerate (velocity should always be c), then it gains energy (i.e., color - becomes blue shifted), and vice versa - if it descends it loses energy (color) and becomes red, infrared, radiored, etc. If the gavity is strong enough, photon may lose all its energy and ceases to exist. But this energy is not lost, it becomes energy of gravity (i.e., mass of gravitating body increases by hf/c^2 kilogram).

BH appears to be static for us, because from our point of view processes at event horizon slow down to a halt. But if you happen to fall into black hole, you will see that stuff is still passing inside via event horizon (for you it will not then be seen as event horizon).

So it all depends on point of view (reference system).

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