3 ms·
For one, observers inside the event horizon can still observe each other. From the point of view of an observer falling into a black hole, nothing unusual happe
by layer8 1y ago
For one, observers inside the event horizon can still observe each other. From the point of view of an observer falling into a black hole, nothing unusual happens when they cross the event horizon. They still observe stuff falling in with them in the same way as before (assuming a large enough black hole so that the local curvature is negligible).
If Hawking radiation is real, it might also expose information from inside the black hole, possibly solving the information paradox. In that sense, the inside of a black hole would still be “observable” from the outside in the QM sense. But since we don’t know how quantum gravity works, that is an open question.
- agent327 1y agoHow can that be true? Inside the event horizon, there is only one direction: down. If light cannot escape, how can it happily bounce around, reflect on something, then reach your eyes? How could signals from your feet (say) even reach your brain, assuming a feet-first entry into the black hole?
- layer8 1y agoWhen you cross the event horizon, you’re falling at close to the speed of light, relative to the event horizon. But due to relativity, light bouncing off the falling objects still propagates at light speed in all directions relative to the falling objects (including the falling observer). That light can’t move outwards, due to being inside the event horizon, and accelerates towards the singularity, but the observer accelerates to the singularity faster, relative to light being reflected outwards. The falling rest frame accelerates towards the singularity, but within that accelerating rest frame, light behaves normally between objects in that frame (assuming a large enough black hole so that the differences in radial distance between the objects is negligible). Consider two cars driving on a highway at the same speed. If one of the cars decelerates, it appears to be moving backwards relative to the other car, while still continuing to move forward relative to the road. It’s similar for light and an observer falling towards the singularity. They both fall towards the singularity, but light being reflected backwards will fall a bit slower, thus appearing to move backwards relative to the observer, even though the light still moves forward toward the singularity.
- thunderbong 1y agoVery well explained. Thank you