The discussion centers around the nature of the event horizon of a black hole, specifically addressing the curvature of space, the behavior of matter approaching the horizon, and the implications of general relativity in this context. The scope includes theoretical aspects and conceptual clarifications related to black hole physics.
Participants generally disagree on several key points regarding the nature of the event horizon, the behavior of matter near it, and the interpretation of general relativity. No consensus is reached on these issues.
Limitations include unclear definitions of terms like "speed" in curved spacetime, and unresolved interpretations of general relativity as they apply to black holes.
No it is not.Steve1954 said:At the event horizon of a black hole, the curvature of space is infinite.
No it is not. You need to be careful with what you mean by this. The event horizon locally moves at the speed of light, but this is because it is a null surface. It is the event horizon that locally moves at the speed of light relative to all observers. Any observers will have a relative speed below the speed of light.Steve1954 said:Matter falling in therefore becomes accelerated to the speed of light.
Steve1954 said:Comments please
As noted by Orodruin, no it is not. Curvature goes to infinity at the singularity, not the event horizon.Steve1954 said:At the event horizon of a black hole, the curvature of space is infinite.
This isn't correct. The event horizon is an outgoing null surface, so a local description of a horizon crossing is that the horizon crosses you at the speed of light. But this doesn't mean you are doing the speed of light anymore than the fact that light passes you at the speed of light means you are doing the speed of light.Steve1954 said:Matter falling in therefore becomes accelerated to the speed of light.
Although you see this in a lot of popsci sources, it's quite misleading phrased this way. It's better to say that it's impossible to describe something with mass traveling at the speed of light in a coherent way. The "infinite energy" comes from trying to apply the formula for kinetic energy of a massive body to a situation where it is not valid.Steve1954 said:General relativity says infinite energy need to accelerate mass to the speed of light.
You seem to mean proper acceleration here, e.g. acceleration by a rocket. But in the context you are mentioning objects are passing the event horizon in free fall.Steve1954 said:General relativity says infinite energy need to accelerate mass to the speed of light. Comments please
Steve1954 said:Comments please