Question: time relative to the position in the universe?

1. Mar 28, 2005

|imbiQ

My first post here so please go easy if this in the wrong place...

But I have a question which I think I know the answer too but need verification.

Situation: if there were 2 earths of same Mass and Gravity but one is at the centre of the universe (next to creation point-empty) and one was at the outer edge of universe (lots of space matter) time would be the same on both worlds.

Premise: Time is determined by the gravity and speed of light constant not the 'location' or how much other matter is closer to it.

So my question is : if you were on an earth next to a black hole (lets just say you could survive) would time grind nearly to a halt?

2. Mar 28, 2005

SpaceTiger

Staff Emeritus
We don't think there's any center to the universe. I'm not sure what you mean by "time would be the same". If they were at rest with respect to one another, then they wouldn't measure any time dilation. If the earths were identical, I don't think they'd experience any gravitational time dilation either.

Everything would seem normal to you, but from the point of view of an outside observer, your time would have slowed down considerably, depending on how close you were to the event horizon.

3. Mar 28, 2005

|imbiQ

OK to be more specific Centre of the Universe would be the point of the Big Bang occurrence.

Yes the second part is an objective (removed from the earths) view of time - then you would be viewing the two earths from a equidistant point.

Is the latest theory that at the event horizon time would stop all together? i cant remember..

4. Mar 28, 2005

SpaceTiger

Staff Emeritus
In space, there is no point of the big bang occurence. If you imagine inflating a balloon from an infinitely small size (a two-dimensional analogy to the expansion of the universe), what point on the surface of the balloon would you call the center? The answer is that there is none. In other words, the big bang happened everywhere.

If by point of the big bang you mean the point in spacetime, then in theory, it would experience an infinite time dilation relative to any other point, though I doubt this is possible in practice.

If you're standing at a distant point and observing both earths, then they'll both have an equal gravitational time dilation relative to you (assuming you mean people on the surface).

Yes, but only from an outside point of view. From the point of view of the person falling in, all is normal.