7 ms·
No. You can imagine the fabric of space being dragged into the black hole faster than the speed of light. Since nothing within spacetime can move faster than th
by ealloc 14y ago
No. You can imagine the fabric of space being dragged into the black hole faster than the speed of light. Since nothing within spacetime can move faster than that, no signals can ever leave the event horizon.
It's like a swimmer going over a waterfall. The water is like spacetime being dragged towards the black hole, and the swimmer is an object moving within spacetime. If the waterfall is falling faster than the person can possibly swim, the person can never get back up the waterfall.
For more info on this "river model" of spacetime, see:
http://jila.colorado.edu/~ajsh/insidebh/waterfall.html http://jila.colorado.edu/~ajsh/insidebh/waterfall.html
http://arxiv.org/abs/gr-qc/0411060 http://arxiv.org/abs/gr-qc/0411060
Relatedly: Since spacetime can "flow" faster than the speed of light, you might think this allows FTL travel. Indeed, this idea is called the "Alcubierre drive".
- omegant 14y agoThank you I think this is the most graphic explanation. Then a mass suspended close to the event horizont would be in fact traveling very fast related to the space time inmediately arround and therefore increasing its mass acordingly. Is that right? Could it be possible to use this as a way to extract energy from the blackhole? Or more exacly from the space-time falling into the blackhole? Kind of river mill. (please forgive this naive questions!)