We know that

"In the center of a black hole is a gravitational singularity, a one-dimensional point which contains a huge mass in an infinitely small space, where density and gravity become infinite and space-time curves infinitely, and where the laws of physics as we know them cease to operate."

So where does this mass go? A measure of how much matter is there in a object is called mass right? so how does that matter stays in a 1-D space?

We know that matter occupy space so how?

Edit: My question is about how can a singularity exists not about singularity itself.

  • 2
    $\begingroup$ This is still an open question. So, there is no right answer at the moment. One thing to keep in mind, mathematical singularity from the model does not mean that it is really a physical point. $\endgroup$ Sep 28 '18 at 13:42
  • $\begingroup$ @KornpobBhirombhakdi from this question i see that it's our mathematical equations that misbehaves that's why its infinite. So why can't we just step into the reality instead of paper? $\endgroup$
    – weegee
    Sep 28 '18 at 15:37
  • $\begingroup$ @StephenG i mean to ask how can singularity exists by stating basic terms of physics and matter not about singularity. $\endgroup$
    – weegee
    Sep 28 '18 at 18:36
  • $\begingroup$ I think the problem is also nobody knows the reality. $\endgroup$ Sep 29 '18 at 15:05

The notion of "centre of the black hole" is misleading. It treats the spacetime in and around the black hole as if it were normal flat spacetime, with no gravitational distortion. In fact the spacetime is highly curved. So curved, in fact, that "space" behaves more like "time". Instead of "where is the singularity" you should ask "when is the singularity."

The answer to this question is always "in the future". There are no singularities in our past. This is significant, since when we say "there is a pen on the table" we mean that the pen was there a few nano-seconds ago, because of the time light takes to reach us. Everything that we say "exists" actually exists in our past. Singularities are a "when" that have a "before" but don't have an "after". Nothing can have a singularity in its past, because there is no future after the singularity.

So in this sense, singularities don't exist. We can't study them because they are always in the future (due to the extreme bending of spacetime). If we fall into a black hole we will (rapidly) reach the singularity but there is no way to report back about it, since the singularity is surrounded by an event horizon. Some of us may (if we are unlucky) fall into a black hole. For these people the singularity is in their future. But it is not possible for a singularity to be observed, as it can never be in the past of any timeline.

So a black hole behaves "as if" all the mass was concentrated in one point. But don't think of the singularity as a "thing" in the centre of the black hole, but think of it as a "when", and always remember "this is weird, and analogies and metaphor are never a complete explanation".

  • $\begingroup$ That a possible philosophical position, known as subjective idealism, or immaterialism (ask on philosophy.se but off topic here) $\endgroup$
    – James K
    Sep 28 '18 at 18:23
  • $\begingroup$ You are trying to say that everything we do or say is already happened, and yes it's true. Time acts strange in space and in blackholes. So how come the question has to do something with time and about when and already how the singularity happened? @James K $\endgroup$
    – weegee
    Sep 28 '18 at 18:25
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    $\begingroup$ No, I explictly say the opposite. Inside the black hole, spacetime is warped, the singularity isn't in anyone's past it is only in the future. It has not already happened on anyone's time line. In a fundamental and real sense no singularity has ever happened. $\endgroup$
    – James K
    Sep 28 '18 at 18:28
  • $\begingroup$ I'd doubt that @James K the thing that is in the future means it is bound to happen sometime, and after that sometime it becomes the past $\endgroup$
    – weegee
    Sep 28 '18 at 18:33
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    $\begingroup$ But this is the point, there is nothing after the singularity most points in time have a before and after, but a black hole singularity is a "when" which has a "before" but no "after". And, yes, this is weird. From far away, a black hole acts like a newtonian gravitaional mass concentrated at one point. Up close, things are weird. I've edited... $\endgroup$
    – James K
    Sep 28 '18 at 18:46

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