Quote:
Originally Posted by cosmocrazy
So would we be able to experience the gravitational effect yet not see the visual effect i.e if we were close enough to witness a star being sucked into a black hole we could detect the increased gravity from the now more dense black-hole but the star seems not to have been sucked in yet?
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Well, if light can't get to you, then changes in gravity can't either. In GR, gravity propagates at the speed of light.
Note I said "changes in". What is the external field of a spherical mass M confined to radius 2R vs that of one at radius R? It's the same. As mass falls in a black hole, it leaves behind the additional gravity so to speak. All those events that increase the gravitational field the external observer perceives occur before it crosses the horizon.
In this coordinate view, fretting about what happens inside the horizon is meaningless. Events inside never occur. So how can you worry about effects of events that never occur?
That's how it is as far as causal effects go.
-Richard