# Black hole singularty definable In 3D space?

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1. Jan 18, 2016

### nospoon2016

Since the center of a black hole is defined as a singularity and space-time collapses at that point (assumption) is it possible to define this point in 3D coordinates? In other words, is it possible that our universe can not be described as a 3D space but rather as a space with 2.99... dimensions?

2. Jan 18, 2016

### phinds

You are making the mistake of thinking that "singularity" is physical. It is not. In the context of physics "singularity" generally mean "the place where the math mode gives non-physical results and thus does not actually tells us what is going on".

3. Jan 18, 2016

### nospoon2016

I wondered about this because the following is stated on https://en.wikipedia.org/wiki/Gravitational_singularity : "The laws of normal spacetime could not exist within a singularity" and therefore this suggest there is no coordinate system defined at that point/region, or if you like no 'normal' coordinate system. If so such region simply cannot be defined in our known 3 dimensions then our universe is not fully definable in 3D.

4. Jan 18, 2016

### Chalnoth

Well, no. It just means you have to draw a little circle around that point, say, "Here be dragons!" and then never try to infer anything about the universe by using what goes on inside that point. We would need a more accurate theory of gravity to say what does happen inside that region.

5. Jan 18, 2016

### phinds

no, it does not suggest anything, really, because that would be making the same mistake you are making of taking "singularity" to be physical. As Chalnoth has also now pointed out to you, you cannot legitimately do that.