Universe only appears to be expanding.

[Grajek]

Has anyone ever given serious thought that the universe only appears to be expanding because most, if not all, galaxies have a black hole in the center sucking the galaxy into it? If you have X amount of galaxies basically being sucked into the black hole at their centers would it not look like each galaxy is moving away from each other thus appearing to have the cumulative affect of an expanding universe?. Given the limited detail provided with telescopes at a galaxy 10 billion light years away could we even determine that the red or blue shift of a galaxy is due to the galaxy shrinking or moving away from ours? Not to mention what we see is only a 10 billion year old snap shot.

Just wondering(out loud).

 

[DaveC426913]

Has anyone ever given serious thought that the universe only appears to be expanding because most, if not all, galaxies have a black hole in the center sucking the galaxy into it? If you have X amount of galaxies basically being sucked into the black hole at their centers would it not look like each galaxy is moving away from each other thus appearing to have the cumulative affect of an expanding universe?.

Yes it's been proposed. And immediately rejected. The simple geometry just does not result in that observed effect.

 

[John232]

The problem with this idea is that the black holes at the center of galaxies are not pulling everything in the galaxy in it at once, but keeps the stars in the galaxy in orbit together. So then the black hole acts like our sun in the solar system and then these galaxies are moveing away from each other, if that gives you a better picture of the universe.

 

[Grajek]

That does give me a better visual, thanks.

How long can the stars maintain an orbit around the black hole, ball park, before they fall out of orbit and into the black hole.

Thanks again for the explanation.

-Grajek

The problem with this idea is that the black holes at the center of galaxies are not pulling everything in the galaxy in it at once, but keeps the stars in the galaxy in orbit together. So then the black hole acts like our sun in the solar system and then these galaxies are moveing away from each other, if that gives you a better picture of the universe.

 

[russ_watters]

If your idea were correct, the far side of a galaxy would be blue shifted and the red and blue shift would vary with the distance from the center. In short, it would look nothing like what we observe.

How long can the stars maintain an orbit around the black hole, ball park, before they fall out of orbit and into the black hole.

More or less forever.

 

[Plebeian]

How long can the stars maintain an orbit around the black hole, ball park, before they fall out of orbit and into the black hole.

How long will the Earth orbit around the sun before it falls out of orbit and into the sun?

 

[DaveC426913]

How long will the Earth orbit around the sun before it falls out of orbit and into the sun?

Russ put it eloquently: More or less forever.

Bodies don't "fall out of orbit" without good reason.

Then again, a good reason is going to visit us in about 5 billion years. The sun will go all Red Giant on our a$$, expanding in radius until it engulfs Earth in its orbit, and possibly Mars too.

That'll render the idea of "Earth orbiting the sun" kind of ... quaint.

 

[Imax]

The universe only appears to be expanding?

I’ve wondered about that one. If we live in a closed manifold, then some of the images from galaxies are not new galaxies. They would be light reflections of galaxies as they existed billions of years ago.

 

[PhanthomJay]

Then again, a good reason is going to visit us in about 5 billion years. The sun will go all Red Giant on our a$$, expanding in radius until it engulfs Earth in its orbit, and possibly Mars too.

I read quite some time ago that scientists were seriously considering a way, as the sun expands, to move Earth into Jupiter's orbit to avoid the 'heat death' of Earth. True or False?

 

[DaveC426913]

I read quite some time ago that scientists were seriously considering a way, as the sun expands, to move Earth into Jupiter's orbit to avoid the 'heat death' of Earth. True or False?

I think the word 'seriously' must be examined carefully.

 

[xx.jason.xx]

What of the idea that we happen to be in a universal 'void', and the only reason that it appears the universe is expanding is that our observable universe is surrounded by a denser pocket of space?

The only problem is it is essentially unfalsifiable at this point, as we cannot even see the universe outside of our own little pocket.

 

[Chronos]

Er, fantasy.