Question: time relative to the position in the universe?

AI Thread Summary
Time is influenced by gravity and the speed of light, not by location in the universe. Two identical Earths, one at the center and one at the edge of the universe, would experience the same passage of time if at rest relative to each other. Near a black hole, time appears to slow down significantly for an outside observer, but remains normal for someone close to the event horizon. The concept of a center of the universe is misleading, as the Big Bang occurred everywhere, not at a single point. At the event horizon, time theoretically stops from an external perspective, while an infalling observer would not perceive any change.
|imbiQ
Messages
2
Reaction score
0
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 Earth's 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?
 
Physics news on Phys.org
|imbiQ said:
Situation: if there were 2 Earth's 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.

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 Earth's were identical, I don't think they'd experience any gravitational time dilation either.


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?

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.
 
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 Earth's) view of time - then you would be viewing the two Earth's from a equidistant point.

Is the latest theory that at the event horizon time would stop all together? i can't remember..
 
|imbiQ said:
OK to be more specific Centre of the Universe would be the point of the Big Bang occurrence.

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.


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

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


Is the latest theory that at the event horizon time would stop all together? i can't remember..

Yes, but only from an outside point of view. From the point of view of the person falling in, all is normal.
 
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
Back
Top