- #1
Gio83
- 6
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Hi everyone,
I'm not aware if a similar question has already been posed, so if this is the case I apologize and I beg you to redirect me to the relevant discussion.
In the context of General Relativity, the Schwarzschild solution in the frame of reference of an observer at fixed distance from the origin (call him A) possesses the well known event horizon (EH).
Such EH is a boundary of the spacetime for observer A.
Another observer B, freely falling towards the origin, will not be aware of any boundary because in its reference frame there is no horizon (EH is in fact a "removable singularity" of the metric).
Returning to the point of view of A, he observes B falling towards the EH, registering his clock speed (with the aid of light flashes every second, as usual) on his way down and he notes that B's clock speed is slowing down with a rate that indicates that it will take an infinite amount of time for B to reach the radius of EH.
Long story short: from the point of view of A, will B ever cross the horizon?
And: given the relation that links the radius of the EH with the mass beyond it, how can a black hole grow (from the point of view of a distant fixed observer) if everything will fall behind the EH only for t→∞ ?
Best regards
I'm not aware if a similar question has already been posed, so if this is the case I apologize and I beg you to redirect me to the relevant discussion.
In the context of General Relativity, the Schwarzschild solution in the frame of reference of an observer at fixed distance from the origin (call him A) possesses the well known event horizon (EH).
Such EH is a boundary of the spacetime for observer A.
Another observer B, freely falling towards the origin, will not be aware of any boundary because in its reference frame there is no horizon (EH is in fact a "removable singularity" of the metric).
Returning to the point of view of A, he observes B falling towards the EH, registering his clock speed (with the aid of light flashes every second, as usual) on his way down and he notes that B's clock speed is slowing down with a rate that indicates that it will take an infinite amount of time for B to reach the radius of EH.
Long story short: from the point of view of A, will B ever cross the horizon?
And: given the relation that links the radius of the EH with the mass beyond it, how can a black hole grow (from the point of view of a distant fixed observer) if everything will fall behind the EH only for t→∞ ?
Best regards