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Quick question that I was just hoping to get some clarification on. Current theories state that the universe is expanding; with those planets farther away moving away from us at a faster rate.

Is it truly that the universe is expanding or could it be a result of us being "pulled" towards the black hole at the center of our universe while being whipped around in a vortex?

Due to angular momentum its not a direct free fall towards the black hole but orbiting around it. It would account for the reason why the only planets not seemingly moving away from us are in our direct vicinity. I'm sure there is some fault in this logic, and hope those more knowledgeable than I can clarify.

Qmechanic
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Bret
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2 Answers2

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First of all, the Universe isn't expanding according to "current theories". It is an observational fact.

Second, there is no center of the Universe. Space was created, and started expanding. This expansion pulls everything away from each other. Galaxies lie approximately still in space, but space is expanding. This means that no matter where you are located in space, you see all the other stuff recede from you.

An often-used analogy is a balloon with ants on the surface. The ants' world is the surface of the balloon. In this 2D analogy of a 3D Universe, there is no up or down, only left, right, forward, and backward. When you inflate the balloon, every ant will see all the other ants move away, even though none are actually moving across the surface.

Similarly, we see all galaxies move away from us, no matter if we look north or south. If your scenario were true, we would move in a certain direction. If this motion were on small scales (the black hole were nearby), then if galaxies in, say, the northern hemisphere were receding, galaxies in the southern hemisphere would be approaching. If it happened on much larger scales and all galaxies were moving in the same direction, we would see no apparent motion of the other galaxies.

Thus, your scenario — while in principle not physically impossible — is inconsistent with observations.

pela
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First of all, there is NO centre in the universe.

I know it's not a good analogy, but think of the universe as the surface of a balloon. Forget the interior, we're only looking at 2 dimensions, whereas the real universe has 3 of them. Put some ink dots on the balloon, which represent galaxies (note: NOT planets).

Now inflate that balloon. You'll see that every dot moves away from every other dot, yet there is no centre to the expansion. The further 2 dots are apart, the faster they're moving away from each other. The same kind of thing happens in the universe - but in 3 dimensions, not 4. No galaxy can claim to be the centre, every one moves away from every other. The separation speeds is determined by the distance between them, as stated in Hubble's law:$$v = H_0D$$ where $H_0$ is the Hubble constant. Recent measurements set it at about $68 km/s$ per megaparsec, or about $224 km/s$ per million light-years distance. Hence it really only becomes important when we are talking about distances of tens of millions of light-years, or more.

You will not see the expansion within a galaxy, or even within a cluster of galaxies, as the internal gravity is stronger than the expansion force. And you will certainly not see it within a planetary system.

Of course, if black energy keeps hold, in the really distant future (trillions of years) even planets may be ripped apart. But we need not worry about just yet!

hdhondt
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