Understanding Black Holes: Perspectives and Questions

In summary, the conversation discusses the different perspectives of a hovering and free falling observer near a black hole. The hovering observer would see the external universe evolve at a fast rate, while the free falling observer would see it slow down. This is due to the effects of gravity on light. The falling observer would also not be able to see inside the black hole, as light cannot escape it. It is also suggested that the event horizon may store light from all objects that have fallen into the black hole, allowing the falling observer to see them instantaneously.
  • #1
Thunderclap
3
0
I want to clarify some stuff about black holes and have some questions:

1) From the perspective of a hovering near the event horizon observer an external universe evolve at very fast rate. But from the perspective of a free falling observer an external universe slows down. Correct?
2) If (1) is correct, the next question is Why actually the free faller would see an external universe slowing down?
3) The falling observer would never see what is inside a black hole since light can’t escape it. So all he could be able to see in front is contracting “black spot” all the way towards singularity. Am I correct?
4) Is light from all of objects that fell into a black hole stored on its event horizon? So the falling observer would see instantaneously all these objects at the EH?

Hope someone can clarify it for me.
 
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  • #2
1) I believe this is correct.
2) The best clock there is, is light and whether it is red shifted or blue shifted. The hovering observer would see light gaining energy as it approaches the event horizon so it would be blue shifted. A free falling observer however would see objects behind him seem to move farther and farther behind him*. The light reflected off objects that appear to be moving away from him would be red shifted.

* If you drop two objects one after the other, to each object, the other will appear to be moving away from it because the first object is already moving away when the second object is released.

3) and 4) I will leave to others.
 

1. What is a black hole?

A black hole is a region in space where the gravitational pull is so strong that nothing, including light, can escape from it. It is formed when a massive star dies and collapses under its own gravity.

2. How big are black holes?

Black holes can range in size from a few miles to billions of times the mass of our sun. The size of a black hole is determined by its mass, with larger masses resulting in larger black holes.

3. What happens if you fall into a black hole?

If you were to fall into a black hole, you would experience a phenomenon called spaghettification, where the gravitational pull of the black hole would stretch and compress your body until you eventually reach the singularity at the center. At this point, the laws of physics break down and we do not know what would happen.

4. Can black holes move?

Yes, black holes can move and are actually constantly in motion. They can be pulled and pushed by the gravitational forces of other objects, and they also have their own rotation.

5. Are black holes dangerous?

Black holes are not inherently dangerous to us as they are located far away from Earth and the chances of encountering one are extremely low. However, if we were to get too close to a black hole, the intense gravitational pull could have dangerous effects on our bodies and technology.

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