# A quick question from a layman about folding space time

1. Jan 19, 2014

### Kargo

I was just doing some thinking about the folding of space time. I have seen a demonstration that a piece of paper is folded in two and a hole is poked through the two layers. Are there any negative consequences and if so what are the consequences of folding space time, and what are the consequences of poking a hole in it? Forgive me for my ignorance in physics, but when I have a question I found that it is best to go to the most qualified source for the answer. I am not, by any means, a physicist. Thank you ahead of time for your thoughts and hypothesis.

2. Jan 19, 2014

### tiny-tim

Hello Kargo! Welcome to PF!
Yes, that's the standard picture of a "wormhole" …

a short-cut between two points in space which are a long distance apart.

Some people speculate that when a black hole is formed, and things literally disappear into the singularity, they reappear somewhere else in the universe in a sort of "white hole".

But nothing is folded … the diagram shows the space folded only so as to get it all on the same page!

3. Jan 19, 2014

### ChrisVer

I don't get the question that much...
putting a hole in the folded one, means that you change the topology of it.

what also do you mean what's the consequences of folding it? Nothing really. The folding happens over a symmetry (eg conformal symmetry), so either you work on the 1st or the 2nd space, you can go between each other without a problem. Now if you change/drop out pieces of one of the space, then I am not sure if you can go back to your initial without a problem (what about the points around the holes? you can't find a neighborhood around them that can be mapped in a neighborhood of the other). If someone can correct my idea if it's wrong.......

4. Jan 19, 2014

### Kargo

Thanks Tim for clearing up the whole folding thing, I will google wormhole.

5. Jan 19, 2014

### Kargo

I apologize for my ignorance on this subject. What I was trying to find out is what if any catastrophic effect might happen?