What happens when an object approaches an event horizon?

In summary, the "picture" is that an event horizon is dependent on a frame of reference, and that when an object crosses the event horizon, its view from the reference frame changes. According to the video, this can lead to an indefinite position for the object.
  • #1
.Scott
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My question is: Is my picture of what happens as something approaches an event horizon accurate - and are there any citations describing it?

I got my "picture" from a PBS broadcast several years ago. It was since mentioned in these forums, but I haven't been able to find an explicit mention of it in the literature accepted by this forum.

The picture is this: First, an event horizon is dependent on a frame of reference. One object "Bob" can enter the event horizon of the reference frame of another object "Alice". I've seen what Bob sees described as "No Drama" - he simply sees his watch cross through some particular time, say noon, as he crosses the horizon.

On the other hand, red shift and other effects prevent Alice from "seeing" much at all. But the events as described from her reference frame would be:
1) Bob's watch never reaches noon and Bob never reaches the event horizon. In Alice's universe, Bob's time slows almost to a stop.
2) Because of this "time freeze" and HUP, Bob's location cannot remain definite - and he begins to spread out over the event horizon.

It's that last point that I'm having trouble with. When I try to find citable papers on how the issues resolved the bet (at least in the minds of Preskill and Hawkings), I find "Euclidean path integrals" with no mention of this "popular" explanation.

Still, it makes sense that Bob cannot remain both stationary in time and fixed in space from Alice's reference frame. So I expect that Bob would take on an indefinite position - again, in Alice's reference frame.

So what is the real scoop?
 
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  • #2
Stanford U's Susskind on the development of the Holographic Principle 55 minutes.
 
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Likes .Scott
  • #3
So, don't miss Susskinds jeremiad on erroneous take-aways from difficult analogies.
 
  • #4
From my work computer, I cannot view that video - but "thanks", I'm pretty sure what the content would be and I'll view it later.

Is that a citable source according to these forum rules? I have two reasons for asking. First is that I replied to a post describing this effect and was told it was misinformation. Second, it seems to bear on the "firestorm" that is currently being described as occurring behind the event horizon - and I don't want to walk into that question without being sure on this point.
 
  • #5
Doug Huffman said:
So, don't miss Susskinds jeremiad on erroneous take-aways from difficult analogies.
I won't. Especially since I am tempted to make some potentially erroneous take-aways.
 
  • #6
Doug Huffman said:
Stanford U's Susskind on the development of the Holographic Principle 55 minutes.
That video made quick mention of Heisenberg Uncertainty Principle, but not at all in the way I had seen it presented before. In the earlier video, Alice had a chance to spread out. In this case, she simply fried. I think what happens is both.

What was really interesting about the video was Suskind's terse description of how Alice's view of Alice compares to Bob's view of Alice. It is simply that both are views of the same event from different reference frames.

This leads directly into my question about the black hole firewall - which I will post in another thread.
 
  • #7
You are mixing quantum mechanics and gravity, which is something we don't know how to do.
 
  • #8
Khashishi said:
You are mixing quantum mechanics and gravity, which is something we don't know how to do.
We'll have to struggle with it.
 

Related to What happens when an object approaches an event horizon?

1. What is the HUP at an Event Horizon?

The HUP, or Heisenberg's Uncertainty Principle, is a fundamental principle of quantum mechanics that states that it is impossible to simultaneously know the exact position and momentum of a particle. This principle also applies to objects near an event horizon, which is the boundary around a black hole where the gravitational pull is so strong that not even light can escape.

2. How does the HUP affect objects at an Event Horizon?

The HUP at an event horizon means that the uncertainty in an object's position and momentum becomes extremely large. This is because the intense gravitational pull near the event horizon causes the object's position and momentum to change rapidly and unpredictably.

3. Can the HUP be observed at an Event Horizon?

No, the HUP cannot be directly observed at an event horizon because it is a principle that applies to the quantum world. However, its effects can be observed indirectly through the behavior of particles and objects near the event horizon.

4. How does the HUP affect our understanding of black holes?

The HUP plays a crucial role in our understanding of black holes. It helps explain why black holes have a defined size, as the HUP prevents the particles near the event horizon from collapsing into a single point. It also contributes to the concept of Hawking radiation, which is the radiation emitted by black holes due to the uncertainty of particles near the event horizon.

5. Are there any exceptions to the HUP at an Event Horizon?

There are no known exceptions to the HUP at an event horizon. This principle is a fundamental aspect of quantum mechanics and applies to all particles and objects, including those near a black hole's event horizon.

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