# Center of the Universe

1. Oct 7, 2007

### Alidow

Okay this may seem like a simple question and may not appear relevant, but bare with me please.

We have been having a discussion in the office about an objects state in time and space. e.g. even though the cup on my desk hasn't moved for two days, it isn't ever in the same place and never will be (relative to the centre of the universe).

If we assume the centre of the universe is where the big bang erm...happened, and we assume we know the speed at which we are moving away from the center of the big pop.

What would happen if we were to move towards the center of the universe at the exact speed that we were moving away from it? Would be achieve total still ness (I don't mean on an atomic level)? What affect might this have this have on space time?

2. Oct 7, 2007

### Ich

Try to formulate you question again under three assumptions:
1. There is no center of the universe
2. The Big Bang happened everywhere
3. Nature doesn't care about absolute speed

3. Oct 7, 2007

### DaveC426913

Yes, as Ich points out, there is no centre of the universe - or more accurately, everywhere is the centre.

I'll use the venerable balloon analogy.

Consider ants living in the 2-dimensional surface of a balloon. They perceive up, down, left and right, but they have no concept of in/out.

The ants are all standing shoulder to shoulder on the balloon's tiny surface. Suddenly, the balloon expands to 100x its former size. Every ant sees its neighbour move away from it proportionally, until they are all 100x father away. Every ant thinks it is at the centre - and not moving at all - while all the other ants moved away from it.

Which one is right? They all are.

4. Jul 10, 2010

### Quantum-lept

These people do not think there is a center to the universe, due to certain assumptions. How they arrive at this i do not understand, though i do understand some of the analogies concerning the universe as described by their mathematical models. But, most of it does not make any sense, though it all may be correct.

As for your question about reversing direction and moving at a speed equal to what you were....Until a center is calculated, and that would be from an edge, what you purpose would be impossible to do. And i doubt that your mass would affect space/time very much..(:..i guess that you would see the universe pretty much as you did, until you traveled for several million years...(:

5. Jul 10, 2010

### Fredrik

Staff Emeritus
There are probably hundreds of these threads already. These are a few that I contributed to: 1 2 3 4

6. Jul 10, 2010

### ZikZak

Not without dinner and flowers.

Others have discussed with you the fact that there is no such place as "the center of the universe." Aside from that, it is a very important concept in physics that there is no difference between uniform motion and what you call "stillness," or rest. There is no such thing as a state of absolute rest; i.e. space does not have any little special signposts stuck in it against which you can measure your absolute speed. You can only measure your speed relative to other bodies in space, and no matter what that speed comes out to be, objects in your spacecraft will still all behave exactly the way they do when you are at rest, or any other speed, relative to those bodies.

In other words, there is no experimental way to determine whether you are "totally still" or not: all experiments on board your spacecraft yield identical results, regardless of your state of uniform motion. This important principle is called the "Principle of Relativity."

7. Jul 10, 2010

### BruceG

But nature does care about absolute acceleration.
So you could choose some galaxy or galaxy cluster which is not accelerating (i.e. is in an inertial frame) to be the centre of the universe. Then you could try moving in a spaceship so that you keep a fixed distance from it. To do this precisely you would have to keep accelerating a bit to correct for changes in the rate of universal expansion. So you would be moving in a non-inertial frame which in principle you would feel.

8. Jul 10, 2010

### Staff: Mentor

This thread is 3 years old.

Locked.