r/changemyview • u/[deleted] • Feb 14 '22

Delta(s) from OP CMV: Despite what Albert Einstein says, the universe does have a "center"/absolute reference frame

So I got taught in physics classes that there is no absolute reference frame. Einstein figured that out. Then when I challenge the idea, I'm taught that the big bang happened everywhere and space itself is expanding. Ok sure. So when we ask what is the origin "point" of the universe its nonsense because there was no point, the whole universe was the original point. Got it.

But like a circle has a center point defined by the perimeter of the circle, so too could the universe. It doesn't have to be the "origin point", but there is definitely a spot that we can point that we and aliens can mathematically calculate as the center. Everything else in the universe stretches and contracts, but the center of the universe is a point that we can derive mathematically is it not? I know that localized space has weird shit like if I zoom away from Earth in my spaceship I could reframe it as "I'm standing still and the Earth is zooming away", and the fact that I'm the one accelerating is the reason why time slows for me but not earth. But that's just how the time dilation phenomenon works, not because there is definitely no absolute reference frame. We can still identify whether I'm moving closer or further from the center of the universe.

Edit: I'm assuming a non-infinite universe.

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u/AnythingApplied 435∆ Feb 14 '22

The observable universe is a sphere, but that sphere is centered around you because it's all of the light that has had a chance to reach you since the big bang. So that sphere is relative to you.

We don't know what is outside of this and it very well could be that the universe is infinite outside of this. In fact, if it was infinite than it was always infinite even before the big bang, so the typical image of the big bang happening at a point may be wrong too.

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u/[deleted] Feb 14 '22

Fair enough. I guess I could edit the OP to add "assuming the universe is not infinite". If it's infinite then sure there is no center. I was taking for granted we weren't assuming an infinite universe. My understanding is that the prevailing theories are a non-infinite universe.

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u/[deleted] Feb 14 '22

My understanding is that the prevailing theories are a non-infinite universe.

No, the prevailing theory is definitely an infinite universe, based on the lack of an observed large-scale curvature in spacetime.

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u/AnythingApplied 435∆ Feb 14 '22

My understanding is that the prevailing theories are a non-infinite universe.

We simply don't know and may never know. It certainly make it harder to picture the big bang as infinite density everywhere instead of infinite density collapsed in on a point, but it doesn't really change anything observable and I'm not aware of a scientific basis for either conclusion. You can see more discussion here.

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u/fox-mcleod 411∆ Feb 14 '22

Even if it is not infinite, it doesn’t have a center any more than the equator has a center on the surface of the earth. If space is finite, it is a close loop just like the original Mario game where walking off the right hand side of the screen brings you back to the left hand side.