Expanding universe theory

bogwalrus

Can someone please have a look at this theory for me.

I'm going to explain it in my own way.

The universe and all it's matter is expanding uniformly and at a
relative speed to eachother. This meaning all the atoms in your head
are expanding away from eachother but relative to the universe so that
your head does not grow before your eyes.

If I was to explain the above another way.

If we lived 100 billion years into the future to find ourselves living normal lives
we would be 100 times larger than what we would have been back in the earlier smaller universe, it's just that we would not notice it. But where would physics come into play here? I read that the beings living in the future larger universe would experience delays in their thoughts due to the fact that the energy travelling from one part of the brain to the other would take a longer length of time etc.

I suppose what is being said is that all matter is expanding including us. It is like when you draw a person on the surface of a balloon and blow it up.

Is this a recognised fact of the universe?

If so, what are it's implications with relation to gravity and other parts of physics.

Could this uniform expansion be the reason for the space between atoms?

Gurgle

bogwalrus wrote: »

The universe and all it's matter is expanding uniformly and at a relative speed to eachother. This meaning all the atoms in your head are expanding away from eachother but relative to the universe so that your head does not grow before your eyes

Don't think so.
The molecules in solid matter (e.g. your head) are held together by EM forces. Atomic bonds aren't expanding with the universe.

Xios

I heard a theory that the universe was not accelerating in speed, but that time was slowing down or leaking out of our universe, giving us the sense that everything is speeding up. But that's kind of off topic, as it only concerns the rate of expansion, not the fact that there is or isn't expansion happening.

bogwalrus

Gurgle wrote: »

Don't think so.
The molecules in solid matter (e.g. your head) are held together by EM forces. Atomic bonds aren't expanding with the universe.

they may not be expanding but stretching possibly? as in the distance between the matter (i.e, atoms) is greater but not noticeable due to its relation with the whole universe.

You would not be able to empirically measure the difference but possibly infer the effect through some other physical phenomena.

It kinda makes sense to me that in an expanding universe everything in the universe is in some way connected with the expansion of that universe. Glued to the fabric of space. So why cant the matter expand evenly and in a proportionate way as the universe expands?


Another way of thinking around this is through graphic design.

If you blow up an image of Mariotm you will have alot of pixels in its area. If you shrink it you will have less. But lets say that each pixel is an atom. How do the atoms in the blown up picture differentiate from the ones in the smaller picture. It is the same image afterall just in different states/sizes.

There should probably be a mention of fractals here.

Gurgle

bogwalrus wrote: »

It kinda makes sense to me that in an expanding universe everything in the universe is in some way connected with the expansion of that universe. Glued to the fabric of space. So why cant the matter expand evenly and in a proportionate way as the universe expands?

In that case, we wouldn't be able to detect the universe getting bigger. The scale of everything increasing at the same rate would appear perfectly static.

As it is, we can see that galaxies are moving away from each other.

Morbert

The forces and particle interactions are enough to overcome the minute expansion of space that takes place around us. But if the rate of expansion increases sufficiently, we would indeed be ripped apart. As would our individual atoms.

Remember that the expansion of space does not imply the expansion of everything. The size of an electron, for example, would not expand with space, nor would chemical bonds.

Morbert

bogwalrus wrote: »

If you blow up an image of Mariotm you will have alot of pixels in its area. If you shrink it you will have less. But lets say that each pixel is an atom. How do the atoms in the blown up picture differentiate from the ones in the smaller picture. It is the same image afterall just in different states/sizes.

Imagine if Mario could be enlarged, but the size of the pixels couldn't be.

bogwalrus

Morbert wrote: »

Remember that the expansion of space does not imply the expansion of everything. The size of an electron, for example, would not expand with space, nor would chemical bonds.

This is what i was wondering. the theory implies that as the universe expands the fabric of space time and all matter gets stretched. If space is considered a fabric this would pretty much happen would it not? Or does space and time just get created as the universe expands into nothingness?

bogwalrus

Gurgle wrote: »

In that case, we wouldn't be able to detect the universe getting bigger. The scale of everything increasing at the same rate would appear perfectly static.

As it is, we can see that galaxies are moving away from each other.

I see what you mean. The galaxies that are moving away from eachother is measured by red shift yes?

My point really is that matter at the micro level not the macro level is where the stretching is occurring, un- noticeable. matter at macro level can move around but the atoms in that are stretching relative to the universe's expansion.

pretty much hitting a wall with this now, i doubt anything more interesting can come from this theory other than what has been said.

Morbert

bogwalrus wrote: »

This is what i was wondering. the theory implies that as the universe expands the fabric of space time and all matter gets stretched. If space is considered a fabric this would pretty much happen would it not? Or does space and time just get created as the universe expands into nothingness?

It is somewhat counter-intuitive, but the universe does not need something to expand into. General relativity describes space and time as components of the gravitational field. So while we're normally used to thinking of particles and forces as embedded in a background of space and time, we now have to think of spacetime as a background independent physical field itself, not embedded in anything.

And yes, while it might seem that matter should be stretched, we have to remember that matter is not continuous, and is comprised of particles (at least according to the standard model) and these particles and the forces between them are not stretched. So if expansion does get rapid enough to affect us on our scale (as opposed to just intergalactic distance scales it affects now) then the results will be disastrous. We would be ripped apart, like a big Mario made of tiny pixels.

del88

Is it possible that the universe is still under the influence of the big bang....a bit like a bullet from a gun ...it accelerates from a stationary position for the first second or two before resistance in air starts to slow it down.......the further away the galaxies the more time it's had to to be accelerated from the big bang ....why wouldn't they still be accelerating...makes sense to be:rolleyes:

rccaulfield

Its something i never questioned so thanks for that! I somehow imagined that the expansion was happening in the vacuum of space and not in the matter on planets etc! Can you find out the speed atoms should be expanding here on earth from the speed the galaxies are distancing themselves from each other?- the further apart they are that is!

Xios

Here's a thought, imagine a box of steel chains. The box is gradually gettin bigger. As it does, it pulls the chains along with the new growth, moving them along. Now we can move those chains around, but we cannot make the any longer or shorter, they stay the same size, only the box changes. So to the chains the box is getting bigger and to the box the chains are getting smaller.

So perhaps the universe is not expanding, but matter is shrinking :eek: (i don't think this though)

Podge_irl

Gurgle wrote: »

In that case, we wouldn't be able to detect the universe getting bigger. The scale of everything increasing at the same rate would appear perfectly static.

Light still redshifts in such a scenario.

Gurgle

Podge_irl wrote: »

Light still redshifts in such a scenario.

But would it....
If the light's wavelength was increasing at the same rate as the universal expansion, wouldn't the relative size of the wavelength remain static?

Gurgle

del88 wrote: »

Is it possible that the universe is still under the influence of the big bang....a bit like a bullet from a gun ...it accelerates from a stationary position for the first second or two before resistance in air starts to slow it down.......the further away the galaxies the more time it's had to to be accelerated from the big bang ....why wouldn't they still be accelerating...makes sense to be:rolleyes:

Yep, that was the standard model until not too long ago.

The universe however has decided to be uncooperative and continues to accelerate rather than expanding at a steady rate or starting to slow down.

This has lead to the reimagining of 'The Ether' in the form of 'Dark Energy'.
A placeholder magic force that may or may not exist but is needed to fill the gaps in the maths/physics.

Anonymo

Bogwalrus, I think the problem with the way you're thinking about this is to do with the issue of what are clumps of matter. The universe has been shown to expand using things like redshifting of supernovae, etc. Now the issue you propose is whether this means everything is expanding. If what you suggest were correct, i.e. matter is expanding then the forces that bind atoms together and so on would be weakening. Gravity is a much weaker force than electromagnetism or the strong (or weak) forces so clearly matter cannot be expanding. What is happening? Well clumps of matter such as galaxies are said to have virialised (another word for clumped). The virialisation radius is the same in time (more or less) so what happens in an expanding universe is that virialised masses move apart (you can think of a virialised mass as a point on the surface of a balloon - as you inflate the balloon two of these points move further apart).

If you're somewhat familiar with general relativity another way to think of this problem is: The expansion of the universe is to do with a global distance measure. Locally spacetime looks flat (Minkowski) and it is only in the global context that tidal forces become important. The problem with bogwalrus question is the application of a global metric problem to a local metric.

Hope this helps.

bogwalrus

thats spot on anonymo. Thanks for that information. gradually getting my head around general relativity