# I Beyond space and time

1. Jul 11, 2016

### momo666

Is there anything in all of physics about objects "beyond" or "outside" space and time?

Do black holes qualify for such a description? What about the hypothetical Big Bang Singularity?

2. Jul 11, 2016

### newjerseyrunner

I suppose you could take some multiverse concepts this way. There are also far off parts of the universe that we are not causally connected to. Black holes I would not give this description, as they are physical objects in the universe. Their space is warped to the extreme, but they get pulled with gravity, they experience entropy (we think,) and they will eventually die (we think.) The big bang singularity was not a point in the universe, it is the universe, just way way way denser.

3. Jul 11, 2016

### rootone

The big bang singularity idea is just that extrapolating backwards from what we can see now, the universe must have a beginning.
As opposed to being eternal and overall being in a 'steady state' .
There is no evidence I know of suggesting that the latter is true, but plenty supporting the first.
'Singularity' is another way for saying 'the math stops making sense here and we don't really know what happened'
A mathematical singularity does not describe a physical object, it describes conditions which we currently don't understand, (although ideas abound, bouncing universe, various kinds of recycling universe, A universe with 28 dimensions, ...)

At one point I Iiked the idea that what goes in to black holes is the same thing we see as the big bang, but apparently that doesn't work because these two singularities have different qualities, one is a time-like singularity and the other is 'spacelike', and apples are not oranges.

Last edited: Jul 11, 2016
4. Jul 12, 2016

### jbriggs444

Yes, the big bang singularity was not a point in the universe. But the part about way way denser is rubbish.

If you graph the function $f(x) = \frac{1}{x^2}$, you will see a pole in the middle where the function diverges toward infinity. The place where x=0 is not "the whole graph, just way way way taller and narrower". It is simply not part of the graph.

5. Jul 12, 2016

### momo666

Can you explain that in more layman terms?

6. Jul 12, 2016

### Chronos

This is most easily conceptualized within the context of set theory. A set can be any collection of numbers desired, and either continuous [include all values between designated boundary values], or discontinuous [restricted to only include values that meet designated criteria, such as only numbers divisible by two]. A set is infinite if it includes an unlimited number of members, regardless of whether it is continuous or discontinuous. The universe is an infinite set in that it is continuous between the interval of t>0 and t=now. There is no value for t that has ever existed in our universe that is not a member of this set. In theory, there are future and past values for t that fall outside the boundary values, but, they are not acknowledged as part of our universe. Cosmologists generally agree our universe is undefined at t=0.

7. Jul 12, 2016

### newjerseyrunner

The universe evolves. Evolution changes the previous state into the current state. At t = 0, there was no previous state.

8. Jul 13, 2016

### jbriggs444

There is no point where t=0. That falls outside the range that we consider to be part of the Universe. See what Chronos said in #6 above.