How is the Universe able to expand faster than light?

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Offline chris

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We think that the early Universe expanded very rapidly - known as rapid inflation - exceeding the speed of light, which the expansion of the Universe today continues to do.

How is this compatible with light being the fastest thing in the Universe?

Chris
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Offline lightarrow

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How is the Universe able to expand faster than light?
« Reply #1 on: 06/03/2009 14:52:42 »
Because it doesn't expand in space.

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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #2 on: 06/03/2009 15:07:11 »
Because it doesn't expand in space.
Do you mean that space expands, but the light in that space doesn't expand with it? I have trouble getting hold of the expanding space concept. For example, as space expands, do stars become farther apart? Do galaxies become farther apart? Is the expansion uniform everywhere? Do the more distant galaxies seem to expand more rapidly simply because there is more expanding space between us and them?

It hurts my brain just thinking about it. I kinda hope someone comes up with a better explanation for the apparent expansion.

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #3 on: 06/03/2009 15:36:20 »
A very tricky question indeed :)

There is no real relation at all, and that's why 'inflation' is introduced as a explanation.

If you were standing on a very high mountain at night time and first looked to your left and then to your right, you would notice that the starry sky would look 'the same'. The galaxies as well as the stars would seem like 'mirrored' in both directions, with the same type of displacement in 'space'.

When you take those two 'looks', remembering that the universe is said to be 13.7 billion years old, any direction you choose to look, then your combined age will be two times that, right. So you, by sight, have now 'ftl' encompassed 27.4 billions years:) But the light that comes to you from any direction have only been able to travel at most 13,7 billion years, not 27.4 billion.

If the Universe is limited by lights speed 'c', which we count in light years, then why is it that those two observations you made is so extremly 'similar' in matter of size and distribution of heavenly bodies? It have been given a name now btw.
It's called 'The Cosmological Principle'.

It's like they are 'mirror images' of each other?
But there is no way light or gravity could have 'communicated' any 'information' between them as both travel at 'c'?? And 'Information' as written here should be seen as 'any sort of physical interaction'.

So why would our universe be 'homogeneous' in appearance?
We have the uncertainty principle in QM stating that "increasing the accuracy of measurement of one observable quantity increases the uncertainty with which another conjugate quantity may be known". looking at it that way, how can everything be the 'same' as the 'conjugate quantity's' here is those two realities to the right and left of you on that mountaintop, not ever being able to 'exchange any information' as light haven't yet reached both sides. And, then there is the fact that 'CMB' the cosmic microwave background radiation is almost precisely the same temperature everywhere, about 2.725 K.

There is another problem too. That's called the 'flatness problem'.
It questions how the average density parameter can be of the order of 1?

The 'density parameter' is related to the ratio of the amount of matter in the universe and the amount needed to stop expansion. "The standard big-bang theory suggests that once this parameter deviates even slightly from 1 it very quickly approaches an asymptotic value far away from 1 for open or closed universes." Another explanation would be that when the universe is at '1' the current density of the universe is very close to its critical value at which space is perfectly flat.

A density parameter between 0 and 1 would mean an open universe that would continue expanding forever and a density parameter of 1 would mean a flat universe in which expansion slows but never truly stops. Would it be greater than 1 it would mean a closed universe. A density parameter of 5 for example would mean that the Universe should be younger than its oldest rocks:)

So how come it's at 1?

"According to Einstein's field equations of general relativity, the structure of spacetime is affected by the presence of matter and energy. On small scales space appears flat – as does the surface of the Earth if one looks at a small area.

On large scales however, space is bent by the gravitational effect of matter. Since relativity indicates that matter and energy are equivalent, this effect is also produced by the presence of energy (such as light and other electromagnetic radiation) in addition to matter.

The amount of bending (or curvature) of the universe depends on the density of matter/energy present."

We can measure this by looking at how light 'bends' around massive objects like stars giving us an idea of the current density. We can also use the Cosmic Microwave Background (CMB) and the relative frequencys of Type-Ia supernovae at different distances from Earth as measurements.

"Data from the Wilkinson Microwave Anisotropy Probe (measuring CMB anisotropies) combined with that from the Sloan Digital Sky Survey (observing Ia supernovae) constrain Ω0 to be 1 within 1%"

"Indeed, a very small departure of Ω from 1 in the early universe would have been magnified during billions of years of expansion to create a current density very far from critical. In the case of an overdensity (ρ > ρc) this would lead to a universe so dense it would collapse into a Big Crunch in a few years or less; in the case of an underdensity (ρ < ρc) it would expand so quickly and become so sparse it would soon seem essentially empty, and gravity would not be strong enough by comparison to cause matter to collapse and form galaxies. In either case the universe would contain no complex structures such as galaxies, stars, planets and people."

So both  of those phenomena need an explanation and there is where 'Inflation' comes in. "Currently, inflation is the only theory that explains why the observable Universe is both homogeneous and causally connected. During inflation the Universe expanded a factor of 10^54, so that our horizon now only sees a small piece of what was the total Universe from the Big Bang."

And all of this goes into (with the later seen 'expansion') why our universe can be 'bigger' than it 'age' 13.7 billions year. There are different numbers for its possible size, but this wiki http://en.wikipedia.org/wiki/Observable_universe gives it as about 93 billion light-years.

So that's how I understand we have come to the idea of 'inflation'.


--------

It's like a very big puzzle, and to get the real 'volume' of it you will need to look at redshift too.

Here is an alternative view of it :)
http://metaresearch.org/cosmology/DidTheUniverseHaveABeginning.asp
« Last Edit: 06/03/2009 20:08:47 by yor_on »
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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #4 on: 06/03/2009 17:28:51 »
That is a very interesting paper yor_on; it is a little dated; it seems to be about 20 years old.

The one thing I find most difficult to explain in opposition the the BB theory is the time dilation observed in type 1A supernovas. But I used to do experiments at Bell Labs, and I remember how difficult it was to arrive at any outcome that was not in agreement with prevailing thought. When the outcome agreed, the experiment was over quickly and reported. When the outcome didn't agree, the experiment lasted much longer, and sometimes didn't get reported at all.

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #5 on: 06/03/2009 17:55:46 »
Sorry Vern :)
I read it and I liked it.
And I should have looked on the sources perhaps, I definitely missed the 'best of' date here.

I introduced it hoping for a discussion though.
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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #6 on: 06/03/2009 18:36:34 »
It was interesting as I said. It didn't have the latest 1A supernova studies in it and these, if they are real, are very damning to ideas trying to avoid the expanding universe concept.

This is the sentence that dated the material:
Quote from: the link
In 1993, another supernova was seen in a galaxy at redshift z = 0.43. Details of an analysis of those observations are eagerly awaited.
« Last Edit: 06/03/2009 18:40:44 by Vern »

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #7 on: 06/03/2009 18:42:43 »
So do you have a good link to those studies?
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Offline swansont

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How is the Universe able to expand faster than light?
« Reply #8 on: 06/03/2009 18:59:22 »
We think that the early Universe expanded very rapidly - known as rapid inflation - exceeding the speed of light, which the expansion of the Universe today continues to do.

How is this compatible with light being the fastest thing in the Universe?

Chris

c is the speed limit of motion through flat space (i.e. where special relativity applies).  The expansion of space itself is not motion through space, and is not constrained by this limit.  Nothing overtakes the photon, though — it still wins the race.

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Offline lightarrow

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How is the Universe able to expand faster than light?
« Reply #9 on: 06/03/2009 20:00:54 »
Because it doesn't expand in space.
Do you mean that space expands, but the light in that space doesn't expand with it?
What do you mean? Light moves *in* the space while space doesn't.
Quote
I have trouble getting hold of the expanding space concept.
We are talking of the behaviour of the entire universe and you pretend to have these concepts as clear as the billiards' physics?  [:)]
Quote
For example, as space expands, do stars become farther apart? Do galaxies become farther apart?
Yes.
Quote
Is the expansion uniform everywhere?
Don't know.
Quote
Do the more distant galaxies seem to expand more rapidly simply because there is more expanding space between us and them?
It seems so, but surely, one day we'll find some little deviations from this rule and so we will have to look for another model of the universe... [:)]

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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #10 on: 06/03/2009 20:16:32 »
You display your usual brilliance lightarrow [:)] The thing I was trying to understand is: The expanding space contains photons whose wavelengths occupy spacial areas. How can the wavelength not increase as space expands?

We know the wavelength of light does increase with distance, but we attribute that to the Doppler effect.

Edit: Maybe space is expanding and the stuff in it is just going along for the free ride, and not really moving away through space. But if that is true, should we not be able to see that same effect within our own galaxy; after all, it is about a hundred thousand light years across.
« Last Edit: 07/03/2009 02:58:43 by Vern »

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #11 on: 06/03/2009 21:41:40 »
Hmm reading you Vern I got to admit that this also puzzles me. If we by expanding assume that a point in space either somehow becomes more points (Plank sized or:) or that this 'point' just expands doesn't really matters. The question will still be how the wave keeps its 'spatial' form in space. But that is only if we see that wave as something consisting of a entity having a physical locality in space and moving in it the same way 'matter' does.

If the propagation is a 'vibration'  oscillating vertically, touching 'points' in spacetime, and just 'seemingly' traveling a 'real' 3D path in spacetime then the question becomes moot. So that would be a favorite choice for me if it is so. That idea may wreck havoc with a lot of other ideas though :)

I wonder how such an idea could be expressed in a two slit experiment for example?
And why light would follow spacetime's geodesics if so?
 
As well as introduce the question of what it then would exist in except what we can observe. But then again, it seems to my unsophisticated mind not unlike the concept of 'distance' which also seems possible to take under scrutiny, even though we use it at a daily basis without hesitation :) But I'm not swearing by any of those ideas, I just kind of like them ::)) I think, I hope...


--
well, I do hope I do at times.
Ah, think that is:)

----
" If we imagine the wave profile as a solid rigid entity sliding to the right, then obviously the phase velocity is the ordinary speed with which the actual physical parts are moving. However, we could also imagine the quantity "A" as the position along a transverse space axis, and a sequence of tiny massive particles along the x axis, each oscillating vertically in accord with A0 cos(kx - wt). In this case the wave pattern propagates to the right with phase velocity vp, just as before, and yet no material particle has any lateral motion at all. This illustrates that the phase of a traveling wave form may or may not correspond to a particular physical entity. It's entirely possible for a wave to "precess" through a sequence of material entities, none of which is moving in the direction of the wave. In a sense this is similar to the phenomenon of aliasing in signal processing. What we perceive as a coherent wave may in fact be simply a sequence of causally disjoint processes (like the individual spring-mass systems) that happen to be aligned spatially and temporally, either by chance or design, so that their combined behavior exhibits a wavelike pattern, even though there is no actual propagation of energy or information along the sequence. "

Yeah I know :) I like this one
http://www.mathpages.com/HOME/kmath210/kmath210.htm
« Last Edit: 06/03/2009 22:41:03 by yor_on »
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Offline chris

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How is the Universe able to expand faster than light?
« Reply #12 on: 06/03/2009 22:31:14 »
What is interesting to me is that as space i.e. the Universe expands it makes / creates more space which, in turn, makes / creates more dark energy. Therefore, if the thing that is making space is expanding more quickly than light travels, then whatever makes dark energy is also moveing faster than light, presumably...?
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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #13 on: 06/03/2009 22:40:56 »
So do you have a good link to those studies?

This is to Berkley's 1997ff report. It is offered in support of the Big Bang theory. However, they say this supernova blasted forth 11.3 billion years ago. If the life cycle of stars is ten to twenty billion years, how did this thing have time to form since the big bang? Keep in mind that a supernova can not be a first generation star. It burns carbon which can only come from a used up star that lived out its life and died in a blast of its own.

Quote from: the link
With a redshift (or z) of about 1.7, says Nugent, "supernova 1997ff is some 11.3 billion years old, much older -- and much fainter -- than the previous record of z equals 1.2, which corresponds to an age of about 9.8 billion years old." He adds that a supernova at redshift 1.7 "is too far away to have been visible from the surface of the Earth. Only a space-based telescope could have found it."
« Last Edit: 06/03/2009 23:07:53 by Vern »

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Offline JP

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How is the Universe able to expand faster than light?
« Reply #14 on: 06/03/2009 22:54:31 »
We know the wavelength of light does increase with distance, but we attribute that to the Doppler effect.

Actually, it's due to the expansion of the universe: http://en.wikipedia.org/wiki/Redshift#Expansion_of_space

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #15 on: 06/03/2009 22:59:50 »
Jesus Chris:)
I considered my ideas to be rather 'far out':)
Now you tell me that we have 'dark energy' moving FTL, sort of:)

But, why not, if we have an expanding 'empty' space 'containing' a large potential energy, then perhaps dark energy is a property of those minuscule 'rifts' that is created as space expands. Perhaps they could be a equivalent to 'virtual particles' creating a 'mass effect' while hiding under HUP (Heisenbergs uncertainty princiole).

If dark energy was 'moving' as you suggested, wouldn't that be noticeable for us?
« Last Edit: 06/03/2009 23:16:06 by yor_on »
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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #16 on: 06/03/2009 23:05:07 »
Quote from: the link
The most distant objects exhibit larger redshifts corresponding to the Hubble flow of the universe. The largest observed redshift, corresponding to the greatest distance and furthest back in time, is that of the cosmic microwave background radiation; the numerical value of its redshift is about z = 1089 (z = 0 corresponds to present time), and it shows the state of the Universe about 13.7 billion years ago, and 379,000 years after the initial moments of the Big Bang.[50]

This brings up the curiosity; how do we determine the red shift of the CMBR? It is dark-body radiation. What frequencies would one consider if it is just a very narrow band of frequencies?
« Last Edit: 06/03/2009 23:08:51 by Vern »

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #17 on: 06/03/2009 23:08:16 »
We know the wavelength of light does increase with distance, but we attribute that to the Doppler effect.

Actually, it's due to the expansion of the universe: http://en.wikipedia.org/wiki/Redshift#Expansion_of_space


Does that mean that all observed redshift already gave been recalculated and adjusted for this phenomena, or is this a theory without experimental grounding?

---

Or you mean that we don't have to change anything, we just in-cooperate 'expansion' in our current cosmological redshift, sorry I meant 'Doppler effect redshifts ' as 'cosmological' seems to be taken now by this new theory, without needing to change any parameters what so ever?

Didn't the 'expansion' move faster than light after a certain 'distance'?
If that is true we can't really say how big our universe is, can we?
As more and more light will be 'quenched' as space 'grows' faster than light.



« Last Edit: 06/03/2009 23:30:14 by yor_on »
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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #18 on: 06/03/2009 23:57:45 »
This wrecks havoc with my new idea :)
If light is redshifted due both to the expansion and the Doppler redshift.
I knew that we had an accelerating expansion but I did not know that we had it incorporated in the redshift seen. What experiments have we done for distinguishing between Doppler redshift versus 'cosmological redshift'?
Is it even possible to construct such an experiment??

-------
But if I get it right this 'cosmological redshift' still , even if incorporated in 'redshift' as seen generally, is a theory? As I can't find any experimental evidence?

Although the accelerating expansion is corroborated by separate sources as "the cosmic microwave background, gravitational lensing, age of the universe and large scale structure, as well as improved measurements of the supernovae according to http://en.wikipedia.org/wiki/Cosmic_acceleration.

Or am I wrong?


« Last Edit: 07/03/2009 00:15:11 by yor_on »
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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #19 on: 07/03/2009 00:02:42 »
I think they're going with all cosmological red shift, no Doppler. Remember, this all depends upon the thing, whatever it is, that we call space, having the property of elasticity. If suddenly we discover that space-time is actually inelastic, we will be back to Doppler.
« Last Edit: 07/03/2009 00:09:34 by Vern »

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #20 on: 07/03/2009 00:19:46 »
There's no need for spacetime to be inelastic for Doppler redshift to be correct and cosmological redshift to be wrong Vern :) Just accept that light don't travel same as matter do in spacetime :)
I really like that idea, and i absolutely refuse to leave my new 'child' out in the cold...

So, prove me wrong ::))

---

Maybe I will feel different tomorrow though.
:)
« Last Edit: 07/03/2009 00:22:32 by yor_on »
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Offline Vern

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How is the Universe able to expand faster than light?
« Reply #21 on: 07/03/2009 01:32:26 »
I can see a real problem though. We assign a portion of the red shift to cosmological expansion, then we assign a portion to Doppler effect; how do we determine how much to assign to each phenomenon?

It seems that the way the cosmological red shift is explained, it demands to take all of the red shift and leave none for Doppler. [:)] It reminds me of the government.

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Offline lightarrow

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How is the Universe able to expand faster than light?
« Reply #22 on: 07/03/2009 02:52:30 »
What is interesting to me is that as space i.e. the Universe expands it makes / creates more space which, in turn, makes / creates more dark energy.
Chris, do you have any link to papers/documents discussing this fact, that is the creation of more dark enenergy as Universe expands?

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Offline JP

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How is the Universe able to expand faster than light?
« Reply #23 on: 07/03/2009 04:17:39 »
Lightarrow, I went hunting for sources on dark energy being linked to "how much" space there is, and I came up with a couple links:

http://en.wikipedia.org/wiki/Dark_energy#Cosmological_constant
http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/dark_energy.html

It sounds like dark energy is tied to the idea of the cosmological constant, and also to the idea of vacuum energy.  The more vacuum you have, the more dark energy there is. Strangely, according to these links, the vacuum energy predicted by particle physics is way way too high for the visible cosmological constant.  So there's obviously something we don't understand yet.

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Offline JP

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How is the Universe able to expand faster than light?
« Reply #24 on: 07/03/2009 04:23:18 »
I can see a real problem though. We assign a portion of the red shift to cosmological expansion, then we assign a portion to Doppler effect; how do we determine how much to assign to each phenomenon?

It seems that the way the cosmological red shift is explained, it demands to take all of the red shift and leave none for Doppler. [:)] It reminds me of the government.

There's a pretty good theory that predicts how fast the universe is expanding, and how fast distant objects should appear to be moving away from us as a result of that expansion: i.e. it predicts the Hubble/expansion redshift.  On top of this general expansion, things can also be moving locally, which would introduce a regular Doppler shift.  I'm not sure how astronomers assign causes for their shifts, but I'm guessing there's a lot of detailed analysis that goes into it.  For example, a star in orbit very far away from us will be red shifted due to its distance, but on top of that it will have an oscillating Doppler shift depending on its orbit: it will be bluer when its moving towards us in its orbit and redder when moving away.
« Last Edit: 07/03/2009 04:26:34 by jpetruccelli »

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Offline Chemistry4me

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How is the Universe able to expand faster than light?
« Reply #25 on: 07/03/2009 04:47:52 »
What is interesting to me is that as space i.e. the Universe expands it makes / creates more space which, in turn, makes / creates more dark energy.
Chris, do you have any link to papers/documents discussing this fact, that is the creation of more dark enenergy as Universe expands?
He did do an interview:

Dark Matter And The Big Bang

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Offline lightarrow

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How is the Universe able to expand faster than light?
« Reply #26 on: 07/03/2009 09:09:25 »
What is interesting to me is that as space i.e. the Universe expands it makes / creates more space which, in turn, makes / creates more dark energy.
Chris, do you have any link to papers/documents discussing this fact, that is the creation of more dark enenergy as Universe expands?
He did do an interview:

Dark Matter And The Big Bang
I've read it but I sincerely haven't found the part where the professor says that more dark energy is created as universe expands.

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Offline yor_on

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How is the Universe able to expand faster than light?
« Reply #27 on: 07/03/2009 10:51:07 »
Well, first of all, a theory that's not backed by experiments is nothing but a theory, or wouldn't it be more correct to call such an idea a hypothesis? Yep I'm cranky here.

So whether there is a 'cosmological redhift' or not I do not know, but just because a believer have formulated it in a wiki does not make it a fact. Sorry guys, show me the experiments supporting it and I will change my tune though:)

As for dark energy rushing away.
I still think we should be noticing it looking at distant objects. There should be relativistic effects, that is if you don't suggest all dark matter to be rushing away FTL in which case no 'gravitational ripples' ever would reach us, as I understands it. and in that case we would never know, would we?

I must admit that I've always found this strange idea of 'expansion' working only on 'space' a little hard to stomach. There are so many  strange ideas surrounding it that it to me gets very near magic. The idea that it somehow know how to separate space outside of matter from space inside matter, which it has to do if we want to say that only space expands.

There is a alternative view in where it's more about clocks ticking :)
In that idea you will find that what we call expansion is a direct result of "our estimates of volume are too small and our estimates of time are too slow." But then again, there is a lot of people that want to believe differently but if we believe in the idea of Occam's razor perhaps we should listen to him? See for yourself. And Vern, I just know you will like it:) http://www.newscientist.com/article/mg19726461.600-dark-energy-may-just-be-a-cosmic-illusion.html?page=1

------------

What I'm saying here is all about expansion, not about inflation which was a totally different aspect.

--

Ah, another thing that throws me of a little is the idea of it being an accelerating effect.
You see no matter how we look on light, between two frames it will express itself as always coming at 'c', either red or blue shifted, but at all times at 'c'¨. But in this expanding place our universe is thought to be we first of all took away all 'particle properties' of this photon it seems. I mean, how else do you believe it to be 'red shifted'? So we took away one of the most important properties to make our new theory.
---
Thinking about it again. Perhaps we can keep the 'particle aspect to the photon.
And then that argument falls away:)
But the rest still stands.

-------------

Let us place this 'wave' at a 'real' 3D point in spacetime, and then say, in a dark and mysterious voice...

- Behold disciples, how Spacetime grows :)

Now we have to assume that this 'expansion' is equable in all directions, if we don't we will get problems as we then would get both red and blue shift for the photons, ah sorry, wave and, as seen from our frame naturally, with velocity's at times reaching past 'c'. So I will presume that this expansion is equable.

Place your wave of choice at that point... and see it die.
It won't work, sorry, nada,, no no no...
 
As every point in 'space is thought to expand around this point we looked at, in a continuous manner, this wave won't be able to go any where, Every point of it inside spacetime will be directly and continuously redshifted until it is 'quenched' it seems to me :) A easy way to visualize it is to think of every point in spacetime as having mysterious minuscule 'space-balloons' hidden inside it.

When spacetime 'expands' it is those 'space-balloons' inflating and your wave will suddenly be inside them, but inside that first 'space-balloon' you will find it to come ever more 'space-balloons' inflating themselves as your 'spacetime' expands. So as a wave it don't seem to stand a chance, but seen as a 'particle' you might be able to argue that it's not influenced by this constantly 'expanding space'? Perhaps, but I don't see how you can keep any type of 'duality' intact here?

The point I make here is that this wave not only will redshift.
It will also instantly 'disintegrate/diffuse' in all 'directions' simultaneously, if this is correct.

Ah well, I've always loved magic, so, who will refute it :)

--------

The only way it makes some sense to me would be if I saw those 'photons' as particles it seems. Then you will have them more and more 'spread out' in spacetime at this 'expansion', forever(?) isolated in a constantly growing space. That as we then 'delimit' the photon if seeing a 'particle' instead of treating it as a wave.
« Last Edit: 07/03/2009 14:07:10 by yor_on »
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Offline Vern

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« Reply #28 on: 07/03/2009 12:37:31 »
We think a lot alike yor_on; poor you [:)] But you lost me in your balloon model. I have never liked the idea of dark energy, dark matter if it is of the exotic unknown kind, or expanding universe; dark matter would fit in my mind okay if it were simply dark ordinary matter.

So in that sense, I did like the article you linked. They are not quite there yet but they may be on to something.

Quote from: yor_on link above
But how can the distribution of matter account for the apparent accelerated expansion? The most promising model so far has been put forward by David Wiltshire, a physicist at the University of Canterbury in New Zealand (Physical Review Letters, vol 99, p 251101). Wiltshire has shown that by combining Buchert's equations with some strange quirks of general relativity he can explain the supernova observations without resorting to dark energy (New Journal of Physics, vol 9, p 377).

Quote from: yor_on
The only way it makes some sense to me would be if I saw those 'photons' as particles it seems. Then you will have them more and more 'spread out' in spacetime at this 'expansion', forever(?) isolated in a constantly growing space. That as we then 'delimit' the photon if seeing a 'particle' instead of treating it as a wave.

We might could use the Kemp model for a photon. In that model, the observation of the particle is the maxima of the wave point. The field surrounding the point is of the same substance as the point but at less amplitude. Any action imparted by a photon will most probably take place very close to the point but has a diminishing probability to take place at a distance from the point. 
Quote from: Kemp's paper
In this paper it will be shown that there is an electromagnetic saturation constant in nature. Maxwell’s equations will be evaluated to derive this constant. It will also be shown that electric and magnetic change is quantized in nature. This is realized when Maxwell’s displacement current is viewed as the actual photon of energy. The constant charge for and electromagnetic wave is shown to be the curvature of space around its electric amplitude and equivalent to Planck’s constant. A mathematical derivative for frequency is established and a photon model is introduced. Also, Maxwell’s equations are modified to incorporate single photons and the quantum phenomenon.
« Last Edit: 07/03/2009 12:47:47 by Vern »

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Offline yor_on

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« Reply #29 on: 07/03/2009 13:10:48 »
Vern I was arguing it from the point of it happening.
That's not the same as me beliving it for a fact.
The mysterious space-balloons is the nearest analogue I could think of.
If spacetime expands that gotta be rather near to how it does it as the space will grow 3-dimensionally in all directions simultaneously, and as all new 'points' as soon as they are 'here', will become the 'breeding ground' for new 'points' growing, it 'never' stops.
Another way to look at those 'points' might be as a multitude of fountains constantly 'spurting' out new 'points in space', but I like my space-balloons best , biased yep:)
Or can you see another way for those new 'points' to 'materialize?

They need to have a 'size' those points to be able to expand spacetime.
And so will that wave need to have.
If one would like to see those waves as only being influenced in one direction then I would expect waves to be one-dimensional, and that would make them 'brothers' and 'sisters' to strings :)

--
Ok so you read it, the piece of 'expanding' too?

« Last Edit: 07/03/2009 13:43:56 by yor_on »
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Offline Vern

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« Reply #30 on: 07/03/2009 14:03:51 »
You can visualize kemp's saturated wave points as a three dimensional bell curve projecting upward followed by a duplicate bell curve pointing downward. The projected areas represent the amplitude of the electric and magnetic field. If photons existed as such, they would be observed as points even though they would always exist as electromagnetic amplitude fluctuations. In other words, they could only be observed as particles, but they could only exist as waves.

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« Reply #31 on: 07/03/2009 14:14:41 »
So how would that fit in a two slit experiment where you are testing for 'particles' not waves?

-------
He is interesting
And it seems as he have worked on his paper quite a while.
What did you mean by a 'three dimensional bell curve'?
That it would express itself as a 'particle'?
« Last Edit: 07/03/2009 15:09:52 by yor_on »
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« Reply #32 on: 07/03/2009 16:37:58 »
This is the interview with Brian Schmidt, from the Australian National University, who co-won the Gruber prize for his work on the expanding Universe.

It was he who said that the more space you make the more dark energy you make - because space has energy attached to it, and that's what's fuelling the accelerating Universe.

http://www.thenakedscientists.com/HTML/content/interviews/interview/829/

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« Reply #33 on: 07/03/2009 17:46:12 »
Interesting interview Chris; Brian pretty well follows the expansion theory except that I had never before seen the idea that dark energy comes from the the expanded space.
Quote from: yor_on
He is interesting
And it seems as he have worked on his paper quite a while.
What did you mean by a 'three dimensional bell curve'?
That it would express itself as a 'particle'?

I'll look for a graphic of the concept. If I can't find one I'll write a little C program to create one. It is basically just two saturated points with amplitude following a sine curve both in the direction of motion and perpendicular to the direction of motion. This forms a three dimensional bump like a pointy tit [:)] one following the other and one pointing up and the other pointing down.

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Offline DoctorBeaver

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« Reply #34 on: 07/03/2009 22:52:51 »
What is interesting to me is that as space i.e. the Universe expands it makes / creates more space which, in turn, makes / creates more dark energy. Therefore, if the thing that is making space is expanding more quickly than light travels, then whatever makes dark energy is also moveing faster than light, presumably...?

That doesn't necessarily follow. Space is not moving, it is expanding. There is no "thing" moving at all.

Space is not expanding faster than light. To use an analogy I used in another thread, imagine a length of elastic with dots on it. Hold it by both ends and stretch it. The dots will move apart but they do not move on the elastic; they move with it. Each dot is moving away from its neighbour at the same rate, but dots further apart are moving away from each other at a greater rate.

Applying this to the universe you can see that no 2 adjacent points are moving away from each other very fast. However, as with the elastic, points further apart are moving away from each other faster. The further apart they are, they faster they are moving apart as there is more expanding space between them. Each point in space is being expanded at the same rate, but the effect is cumulative. If 2 points are far enough apart then their recession from each other can exceed the speed of light even though those points are not actually moving in space.

Thinking about how this may affect a photon other than by Doppler effects, I don't see that it does. The photon itself is not affected by expansion; it is just the medium through which it is travelling (space) that is affected. All it means is that there are more points in space for the photon to travel through. The further a photon travels, the more points in space it must travel through. Isn't that precisely what causes the Doppler effect? Whether the distant light source is moving, or it is just the space in between that is expanding, the overall effect would be the same.
« Last Edit: 07/03/2009 23:01:11 by DoctorBeaver »
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« Reply #35 on: 07/03/2009 23:10:07 »

I must admit that I've always found this strange idea of 'expansion' working only on 'space' a little hard to stomach. There are so many  strange ideas surrounding it that it to me gets very near magic. The idea that it somehow know how to separate space outside of matter from space inside matter, which it has to do if we want to say that only space expands.


As far as I am aware, dark energy does indeed exist inside matter but gravitational and other forces are holding it in check. This is also the basis of the Big Rip theory.

The Big Rip theory says that inside matter space is expanding at an ever increasing rate but that the other forces are stronger and are holding it back. Eventually, however, the pressure of that expansion will be enough to overcome the other forces. Not only will it overcome the force of gravity and cause stars and galaxies to come apart, but it will act even down to the quark level and cause protons & neutrons to also come apart. All that will be left will be a quark-gluon soup in a universe that is still expanding ever faster.
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Offline Vern

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« Reply #36 on: 08/03/2009 00:17:53 »
That scenario doesn't seem like a place where I would want to live. Maybe if we describe it differently it may become so.

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« Reply #37 on: 08/03/2009 02:24:03 »
Because it doesn't expand in space.


Do you mean that space expands, but the light in that space doesn't expand with it? I have trouble getting hold of the expanding space concept. For example, as space expands, do stars become farther apart? Do galaxies become farther apart? Is the expansion uniform everywhere? Do the more distant galaxies seem to expand more rapidly simply because there is more expanding space between us and them?

It hurts my brain just thinking about it. I kinda hope someone comes up with a better explanation for the apparent expansion.
Actually there is a simple expirement to do to answer your questions.  What you do is have a rubber band tube or something that stretches like a rubber band but in straight not circular. Put something like marbles with wholes in them and put them spread out on the rubber band and then measure the distance now. After measuring stretch the rubberband and the marbles should start to grow apart . you actually dont have to measure if you don't want to.

Light is the fastest thing in Space except for space itself. Space is the only exception to light i learned this on an episode of the univers.  There is a theory out there though that space is not expanding but it is so big that light has yet to still touch some of it and that we are only seeing so many years of light being shined on.

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Offline Astronomer_FB

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« Reply #38 on: 08/03/2009 02:27:29 »
If the universe is expanding doesn't that mean it is fighting all the forces and if it expands so far that it starts to lose the "fight" with gravity and magneic fields, will it collapse and slingshot back to it's beggining size and shape whatever it may be?

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Offline JP

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« Reply #39 on: 08/03/2009 05:08:31 »
Thinking about how this may affect a photon other than by Doppler effects, I don't see that it does. The photon itself is not affected by expansion; it is just the medium through which it is travelling (space) that is affected. All it means is that there are more points in space for the photon to travel through. The further a photon travels, the more points in space it must travel through. Isn't that precisely what causes the Doppler effect? Whether the distant light source is moving, or it is just the space in between that is expanding, the overall effect would be the same.

I think the major difference in practice is that the Doppler shift is calculated from actual velocities (and therefore objects can't be moving apart at greater than the speed of light).  The redshift due to the universe's expansion isn't bounded by this, as distant enough objects can be moving apart at greater than the speed of light.  The two are kept separate probably because physicists like to think of velocities within the universe as distinct from the expansion of the universe, but the effect will be similar, as you say.

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Offline DoctorBeaver

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« Reply #40 on: 08/03/2009 09:50:57 »
Quote
The two are kept separate probably because physicists like to think of velocities within the universe as distinct from the expansion of the universe, but the effect will be similar, as you say.

You mean I was right!? Sort of? Ish? Kinda?
« Last Edit: 08/03/2009 09:54:00 by DoctorBeaver »
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Offline Vern

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« Reply #41 on: 08/03/2009 21:04:03 »
Quote from: yor_on
He is interesting
And it seems as he have worked on his paper quite a while.
What did you mean by a 'three dimensional bell curve'?
That it would express itself as a 'particle'?
Here's that graphic I said I would make for you. It is a little distorted and not exactly right but maybe you can get the drift of it.

The surrounding grid represents the field; the displacement from the normal plane represents electric and magnetic amplitude; one polarity up; the other polarity down; it doesn't matter which.

The point I was trying to make is that with this model, you see both a particle and a wave.



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« Reply #42 on: 09/03/2009 10:05:43 »
planet size will not expand anymore, but the galaxy or asteroid it does. We knows only our universe or the 9 planets. Then NASA discovered the newest planet which is planet Nibiru or Planet Eris it was not align the 9 planets and no direction.. What if the newest planet will collide the other planet. We dont know what will happen to be but it is possible the collision of the planets. We knows already that planet Nibiru has no direction, it was far from our universe then went near to planet pluto and planet Jupiter. Planet Nibiru has no direction and no alignment of rings.

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Offline DoctorBeaver

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« Reply #43 on: 09/03/2009 11:05:15 »
planet size will not expand anymore, but the galaxy or asteroid it does. We knows only our universe or the 9 planets. Then NASA discovered the newest planet which is planet Nibiru or Planet Eris it was not align the 9 planets and no direction.. What if the newest planet will collide the other planet. We dont know what will happen to be but it is possible the collision of the planets. We knows already that planet Nibiru has no direction, it was far from our universe then went near to planet pluto and planet Jupiter. Planet Nibiru has no direction and no alignment of rings.

OK, if you say so. Now would you care to explain how it is relevant to the expansion of the universe and the Red Shift?
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Offline DoctorBeaver

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« Reply #44 on: 09/03/2009 11:08:36 »
Don - that's a nice graphic but I'm not sure I understand exactly what it's meant to represent. I can see the wave but which part of the graphic is the particle?
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Offline Vern

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« Reply #45 on: 09/03/2009 12:41:39 »
Don - that's a nice graphic but I'm not sure I understand exactly what it's meant to represent. I can see the wave but which part of the graphic is the particle?
The points up and down represent the positive and negative electromagnetic amplitude swings, which occur sinusoidally but extend outwardly in amplitude as the inverse squared. When I applied the outward extension, the sine wave was distorted, so the graphic isn't quite correct.

The centre of the bumps up and down are saturated electrically and magnetically. By saturated I mean the maximum possible that space can support. The transition from the flat plane to the top of the bump interacts as if it is a particle. The spacial area around the peak-amplitude bumps interact as if it is a wave.

Here's another copy for quick reference.

« Last Edit: 09/03/2009 12:44:24 by Vern »

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Offline yor_on

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« Reply #46 on: 09/03/2009 13:22:02 »
Nice image Vern.
You seem to be quite handy with C
(more than one way:)

This 'saturation maximum' of a photon that you are referring too.
Is that how you see it acting as a 'particle' then?

And would 'matter' then be constituted of 'saturation maxima' bound together, how?

-------

To me it seems that you can't differ between the expansion pace's redshift, if it's there, and Doppler redshift?
It will be a guess, however educated it might be.

Or?



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« Reply #47 on: 09/03/2009 13:37:16 »
Vern - I apologise for having credited Don with that graphic instead of you.

Thank you for the explanation. I think I understand.
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Offline Vern

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« Reply #48 on: 09/03/2009 13:46:02 »
Quote from: yor_on
This 'saturation maximum' of a photon that you are referring too.
Is that how you see it acting as a 'particle' then?
Yes; I thought of the saturated points as appearing to be particles; however; Dr. Kemp convinced me that it was the transition from zero amplitude to the maximum amplitude that would interact as a particle. According to Kemp, mass is electromagnetic change. So it is the change that makes the difference. The saturated amplitude simply gives us the quantum phenomena.

The state of energy called matter would be composed of these things locked in resonant patterns.
« Last Edit: 09/03/2009 13:49:33 by Vern »

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Offline Vern

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« Reply #49 on: 09/03/2009 13:47:17 »
Vern - I apologise for having credited Don with that graphic instead of you.

Thank you for the explanation. I think I understand.
Hey; no problem; I'm sure Don_1 could have done it; but I suspect Don_1 has a different view of the composition of matter. [:)]
« Last Edit: 09/03/2009 13:50:39 by Vern »