Why is the universe expanding (read entire question please)?

Question

Scientist say in a few million eons from now, the expansion of the universe is so great, that the distance between atoms will be light years. Now scientists blame this on a thing called dark matter expanding. I disagree. Could it be possible that some parts of the universe may contain more mass and be pulling more of the universe towards it, warping space and pulling it further away from other clumps of great mass that generate great amounts of gravity. Sorta like how pepper clumps in groups on the surface of water and pulls other specks from other clumps. This make sense? if yes, do you agree or disagree? Why?

What I mean is it possible that one galaxy or various other massive objects is stretching the fabric of space towards it and gathering more mass and pulling the fabric of space even further, thus making appear it is expanding when in reality the shape is merely changing?

Answer 1

Interesting idea, but unfortunately it's not supported by current observational data (microwave, infrared, gravitational, etc.)

Think of the expanding universe like a loaf of raisin bread you put in the oven to bake.
As it bakes, the dough in between the raisins rises and spreads all the raisins apart from each other.
To any raisin, all the other raisins are moving away from it.

Now think of the galaxies and galaxy clusters like those raisins.
The universe is expanding and is dragging all the matter (ordinary and dark) along with it, making it spread out simply because there is more space in between the large structures (like galaxies and clusters).

The universe isn't like the normal things we think of and experience every day - it's fundamentally a different structure and design than the small stuff we encounter.

Answer 2

Yes and Not...
Some parts of the Universe contain more matter. Those parts are the Galaxies. And the galaxies are pulling the space as you know. But inside the galaxies, the space and the mass have an equilibrium, due to the rotation of the galaxy, so the average distance between the atoms or the stars in a galaxy won't change.

We are inside a Galaxy, and all the universe outside the local galaxies group is expanding. There are a math function to estimate the average speed for the galaxies (Hubble constant [wiki]). The expansion is the same in any direction, so it would not be a local or partial (as you suggest) expansion.

What the astronomers don't know is if the expansion would be for ever or if the universe could start a contraction phase in a far future. The expansion rate seems to be reducing but we need more accurate data to know the future...
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Patrick (see below) told me the universe will expand forever. Maybe... the new-for-me dark energy would be the cause but as I have read, the dark energy is an hypothesis, and the Hubble factor seems to be reducing :► " A value for q measured from standard candle observations of Type Ia supernovae, which was determined in 1998 to be negative, surprised many astronomers with the implication that the expansion of the universe is currently "accelerating" (although the Hubble factor is still decreasing with time; see the articles on dark energy and the Lambda-CDM model)."

How the Hubble factor is decreasing and the expansion is accelerating ? ? ?

Answer 3

In some sense what you describe does happen: galaxies and clusters of galaxies attract each other together, with the most massive regions getting more massive and the least massive regions getting less massive. However this is separate and distinct from the expansion of the universe.

We know the universe is expanding from the fact that all galaxies and clusters of galaxies (with the exception of those fairly close to our own Milky Way such as Andronmeda) are moving away from us, which we can tell via Doppler shift (the principle behind radar guns). Moreover, in relatively recent times, this expansion has been observed to be increasing with speed, that is accelerating. The explanation for this has been attributed to something called Dark Energy which basically no one knows anything about (except that it causes the universe's expansion to accelerate).

Now, against the possibility that this accelerated expansion is some illusion caused by some chance arrangement of mass in our neighborhood is that we observe the expansion to be the same in all directions (it's isotropic, isotropic being a fancy word for "same in all directions"). But to the extent we understand the laws of nature (e.g. physics), nothing can travel faster than the speed of light, not even information. So if we observe the universe expanding in a certain way in one direction, and in the opposite direction we see exactly the same thing, there's no way for these two parts of the universe to have communicated and agreed upon a certain expansion. The expansion has to be something that's the same everywhere because there hasn't been enough time for distant parts of the universe to arrange otherwise.

Additionally, we think we understand the distribution of matter in the universe (in a statistical manner) to some extent, and what we think we know isn't consistent with something which could mimic the expansion of the universe all over the sky. And all this isn't to say that we don't see things being moved around a lot. A lot of the galaxies near us (along with the Milky Way) are all slowly moving in one direction under the influence of a large mass. This is something like what it sounds like you're proposing, except that it only changes how the expansion of the universe looks in one direction (the direction of motion).

And to answer a concern of freedomisbetter, the reason the Hubble factor is decreasing in value is that in addition to containing information about how fast the universe is expanding, it also has information about how large the universe is. For instance, if the rate of expansion of the universe were to be the same when the universe is twice as large as it is today as it is now, then the Hubble factor would be half of what it is today when the universe is twice as large. Another issue is that the accelerated expansion is a fairly recent phenomena in the history of the universe, and so the acceleration has not yet come to dominate the Hubble factor yet.

Answer 4

>Now scientists blame this on a thing called dark matter expanding.

That is not correct. Dark matter is a mysterious form of matter which, although it does not emit electromagnetic radiation, still interacts gravitationally in the normal way. It is used as an explanation for the discrepancy between the spin rates and masses of galaxies. What is forcing the Universe to accelerate in its expansion is not dark matter but rather dark energy, something even more mysterious than dark matter in that it not only does not emit electromagnetic radiation, it also seems to have 'negative gravity' in that it forces other things away from it. It would appear that dark energy is something that arises naturally out of the underlying space of our universe, and that it does not clump together like normal matter and dark matter do.

>I disagree. Could it be possible that some parts of the universe may contain more mass and be pulling more of the universe towards it, warping space and pulling it further away from other clumps of great mass that generate great amounts of gravity. Sorta like how pepper clumps in groups on the surface of water and pulls other specks from other clumps. This make sense?

Of course! Such areas have been found, and they are what we call galaxies and galaxy clusters. At least for the time being, galaxies are able to hold themselves together for a very long time because their gravity counteracts the relatively small amount of dark energy inside them. Dark energy only prevails on a large scale, when you take the vast quantities of empty intergalactic space into account.

It is unlikely, however, that any larger kind of clumping than galaxy clusters exists, or that if it does it is the explanation for the acceleration of the expansion of the Universe. The Universe's own history tells us that this is almost certainly not the case.

Answer 5

Well...unfortunately your idea isn't true. For one, the expanding force is known as Dark Energy. Dark Energy and Dark Matter are actually two very different things, and shouldn't be confused with each other.

Now, yes the universe is expanding, but that doesn't mean that everything is expanding. The electro-magnetic forces holding the atoms in our bodies overpower the expansion, so we won't stretch out. SImilarly, the gravitational forces of planets, stars, and even galaxies are so strong that they will remain in tact.

Rather, it is the fabric of space time itself which is expanding...the space between galaxies.

Finally, what the person said above me is incorrect. Right now, we do know that the universe will expand forever as opposed to contract again. Dark Energy is making it so the universe isn't just expanding, but ACCELERATING! Which means, unless the force can somehow switch from expansion to contraction, the universe will 'die' as a very cold, dark place, and will never contract again.

Answer 6

*twists head to try and understand and ends up forming the shape you describe*

The universe is expanding because of simple momentum left over from the Big Bang.

And your theory could be possible, yes, I mean, we really know nothing about anything. All that we go on right now is the most popular theories. It could be possible that NONE of the existing theories are correct.

I'm just a simple nerd, but it makes as much sense as a lot of other stuff out there. I don't have enough knowledge (yet) to agree or disagree, but I will say that your theory makes perfect sense to me after I warped my head and brain to understand it. :P

Answer 7

First, i could prefer to show out that no one incredibly knows, my guesses are purely that, however the complete universe became into created via the vast bang, meaning that there became into purely one little factor and it exploded. this capacity that we are nonetheless increasing, some thing that became into shot at us with slightly extra stress could hit us, yet that may no longer likely. the factor is that the vast bang exploded quite the two and that i think of that we are going farther faraway from different universes, no longer getting closer. some thing that should pastime you is that there is a theory available (do no longer inquire from me the call) that announces that factor is per how briskly we (the galaxy) is moving and that finally, we (the galaxy) will decelerate and end and time will start up moving backwards. there is yet another theory that what's now going on has already got here approximately and that it's going to proceed going on. i did no longer incredibly get it previously each and every thing, so I won't blame you in case you do no longer.

Answer 8

Sorry, but your theory doesn't make any sense. All matter is moving farther apart from all other matter. Your idea would require a lot of matter to be moving closer together, but the opposite is happening.

Answer 9

This is a fact, the expanding universe is a theory, not a fact.