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Author Topic: Did the universe expand quicker than the speed of light?  (Read 10557 times)

john

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john asked the Naked Scientists:
   According to stephen hawking and other prolific theoretical physcicists, the
planck wall is 10 to the 43rd power seconds(minus) after the initial "explosion. that is obviously a mind boggling short amount of time. it takes
light longer to cross the length of a proton. they then postulate that within
trillionth's of a second,the universe as we know it,including all matter, expanded from about the size of a grapefruit to approximately the
diameter of our current solar system.

my question is this. how could matter within this "big bang" grapefruit expand to the width of our solar system within trillionths of a second as this would EXTREMELY violate the speed limit of the universe, namely, the speed of light?

186200 miles a second is fast indeed,but they are postulating that matter during the first trillion billionths of a second during the birth of the universe,matter was traveling at billions of times the speed of light. how is this possible?
What do you think?


 

Offline Soul Surfer

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Did the universe expand quicker than the speed of light?
« Reply #1 on: 27/01/2009 10:38:09 »
I agree that this extremely fast expansion seems difficult to visualise and against the rules but it is space itself that is expanding as the universe expands from the big bang until now.  The expansion of space itself does not require anything to move faster than the speed of light.

The simplest way of visualising this is to think of there being individual "particles" of space an under certain conditions these particles can interact and effectively create another particle of space from the energy they contain.

The latest thinking and modelling of the gravitational equations suggests that the universe was probably contracting before it expanded it probably had contracted to the extent that the conditions suddenly changed to allow more space to be created and hence the big bang.

I have my own opinions on the detail of how this might happen but they are not part of standard theory and so only presented inn the new theories area under the topic of evolutionary cosmology.  Although this area is due for an update because I have found some new information
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #2 on: 27/01/2009 11:22:22 »
As someone said; things just keep getting weirder and weirder. That's probably how folks felt just before they discarded the notion that the earth was the center of the universe. We know that the size of the universe is too big to have been formed within current physical laws. If your faith is powerful enough, you can just say, well, current physics only applies in current times.

But then, if we discard physics like that, lots of things we think we know might not be as we think they are :)
« Last Edit: 27/01/2009 11:57:36 by Vern »
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #3 on: 27/01/2009 11:29:17 »
Quote from: Soul Serfer
I agree that this extremely fast expansion seems difficult to visualise and against the rules but it is space itself that is expanding as the universe expands from the big bang until now.  The expansion of space itself does not require anything to move faster than the speed of light.
I know that this is the current thinking; but I was wondering how it is that we expand space without expanding time with it. Light is still limited to c within the expanded space. Now we even need space to expand faster than the speed of light. I think the system is about to break down:)
 

Offline LeeE

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Did the universe expand quicker than the speed of light?
« Reply #4 on: 27/01/2009 13:13:37 »
The light-speed restriction only applies to matter or energy, not to space itself, which is neither matter nor energy.  Also, I understand that at this phase of the BB there wasn't any matter; it wasn't created until after the cosmic expansion phase.

Even now though, matter and energy at the opposite sides of the observable universe is receding from each other at > 'c'.  This isn't due to the matter and energy moving through space though, but once again, because space itself is expanding and carrying the matter and energy with it.

If we imagined that there was a maximum speed that boats could travel on water, then if the water was in a lake, with no flow, nothing could travel faster than the maximum water speed.  However, if the water is in a river and has it's own flow then the maximum water speed could be exceeded with reference to the river bank, but not with respect to other boats.
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #5 on: 27/01/2009 13:30:25 »
Yes; I understand the concept LeeE. But I think the concept is becoming so complex that it may break. If you think of light as ageing such that its energy decreases with time in a non linear fashion, you can explain observations without stretching space.
 

Offline LeeE

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« Reply #6 on: 27/01/2009 14:22:23 »
What is complex about it?  It's a really simple concept.  Also, it's not a work-in-progress but is already complete.  As such, how can it become more complex and then break, through some undefined mechanism, as a consequence?

The idea of light aging, once again, by an as yet unidentified mechanism, sounds not only more complex to me, but is also incomplete and will remain so until a plausible mechanism for the aging is found.  Right now, it's not an explanation of what happens based upon the available evidence; it's just an idea.
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #7 on: 27/01/2009 15:12:19 »
Tired light just seems more natural to me than the simple concept of expanding space; but that is what is accepted and I certainly can't create an alternative.
 

Offline nepcon81876

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Did the universe expand quicker than the speed of light?
« Reply #8 on: 27/01/2009 18:21:12 »
thank's for the reply's.after reading your thoughts and doing some more investigating(i am infinitly fascinated w/ space/time mechanics,quantum mechanics etc etc,even tho i was a horrible math student)i can conceptualize space expanding faster than the speed of light since outside of the "space" that is expanding,is nothing(?). i picture an egg expanding in all directions at once,with no limit to the speed of the expansion of the "eggs shell" outward,since outside the egg,there are no applicable laws of physics,arbitrary or not. but within the egg itself, the "yolk" or matter,particles,everything etc... has a limit as to what it can do since it is contained within the "shell".perhaps their are some basic,fundamental flaws in our theories of space/time which will be revealed in the future.like,if space is expanding,WHAT is it expanding to?or in?if their is no space beyond space,what exactly or where are we expanding into?Non-Space? Non-Sense?the proverbial "THEY" say that at the point of singularity,all of our agreed upon laws of physics break down,and cannot/willnot explain what happenned at time 0. trillionsth of a second after "time zero" suddenly they apply.i dont know. maybe since their is no gravitational equations to deal with out side of the "shell",speed does not apply.or even possibly speed does not exist at all as an observable/measurable quanity.(?)and what about tachyons? if i remember correctly,i read some where that they do indeed travel faster than light.i agree with you about the universe contracting first,the BIG CRUNCH.i think it is an endless cycle of expansion until the oringinal enrgy of the "bang" runs out,then all matter begins falling back in on itself due to mass/gravitational mechanics,until the whole thing reaches critical mass,the singlularity,and like a nuclear weapon whose mass/matter whatever is crunched hard and fast enough(light speed?)explodes out ward once again.over and over and over ad nauseum.but then again their's that whole static/non-static universe deal which i admit i know very little about exept whether or not the velocity of expansion outweighs the mass/gravitational properties of the universe and it will keep expanding infinitly until the night sky is eventually just empty of any visible objects.unless we can still see the light of something trillions and trillions of light years away(assuming we sre here to see it).not sure which side of the static/non-static unverse side of the fence i sit on.or all this string theory stuff.bottom line for me i guess is,if their was a big bang,if it is cyclic or just happened once and we are all just floating away from each other for all eternity,before space and time and everything,where the hell did whatever happened come from?everyone tring to figure out what exactly happened at the point of the bing bang,weve got it down to what<googleplex of a second after? thats great>but about time-0.is that where religion and creationism comes in?Because "GOD" is un-quantifiable?any way,my e-mail is gnomosao@hotmail.com,and besides FULL TILT on-line poker,talking about this sh1t is endlessly entertaining to me.again,thanks 4 your comments,hope they keep coming. i tend to ramble and jump around alot,so thanks 4 yuor patience. peace
JOHN.
« Last Edit: 27/01/2009 19:18:14 by nepcon81876 »
 

Offline DoctorBeaver

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Did the universe expand quicker than the speed of light?
« Reply #9 on: 27/01/2009 22:48:28 »
We know that the size of the universe is too big to have been formed within current physical laws.

Not quite. It's the homogeneity of the universe that prompted the inflationary theory that gives rise to estimates of the universe being larger than we can see. We don't know that it's that big.
« Last Edit: 27/01/2009 22:50:22 by DoctorBeaver »
 

Offline syhprum

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Did the universe expand quicker than the speed of light?
« Reply #10 on: 27/01/2009 23:10:42 »
One often sees this figure quoted that the original universe was the size of a grapefruit, would this correspond to the mass of the universe compressed to Planck density ?
 

Offline DoctorBeaver

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Did the universe expand quicker than the speed of light?
« Reply #11 on: 27/01/2009 23:14:37 »
syhprum - I've often wondered if there is an ultimate density rather than infinite density. Loop Quantum Gravity seems to suggest that.
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #12 on: 27/01/2009 23:24:49 »
We know that the size of the universe is too big to have been formed within current physical laws.

Not quite. It's the homogeneity of the universe that prompted the inflationary theory that gives rise to estimates of the universe being larger than we can see. We don't know that it's that big.
Absolutely true; but it we use that criteria there are many other more fundamental things that we don't know for certain. That would probably include just about everything we think we know. I think it was Will Rogers who said:
Quote
It's not so much that we just don't know, it is that we know so much that just ain't so.
« Last Edit: 27/01/2009 23:29:12 by Vern »
 

Offline DoctorBeaver

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« Reply #13 on: 27/01/2009 23:30:52 »
Was he paraphrasing Artemus Ward? “It ain’t so much the things we don’t know that get us into trouble. It’s the things we know that just ain’t so”

Quote
Absolutely true; but it we use that criteria there are many other more fundamental things that we don't know for certain. That would probably include just about everything we think we know

Agreed up to a point. There are certainly some things that we don't know for certain, the size of the universe being just 1 example.
« Last Edit: 27/01/2009 23:32:41 by DoctorBeaver »
 

Offline yor_on

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Did the universe expand quicker than the speed of light?
« Reply #14 on: 28/01/2009 00:12:54 »
I'm exercising my 'petidea' now.

If you allow for time to be bound to spacetime with a arrow macroscopically.
But allow it to behave differently when being in a quantum mechanical state.

What hinders that quark gluon soup from inflate in 'indefinite' time?
Meaning that time might have been anything between null and going both forward and backward at that point
Coordinate systems are what we define, in them we define a vector.
But you can also define only a vector (speed and direction) not bothering with the coordinate system.

A coordinate system is what we find natural when viewing spacetime.
It has a long tradition macroscopically, first the map, then the vector.

But what if there was no coordinate system at that 'point'
And what if it is this indeterminate 'point' then somehow 'split itself up' into an immense lot of points.
Only being able to create what we call 'space' with 'direction' and 'distance'.
As well as 'times arrow' after or under the 'time' we started to get 'matter'?

Then what we define as coordinates is only definable to 'spacetime'.
And spacetime is a result of 'matter creation'.

If you look at how closely 'matter', 'gravity', 'time' and 'distance' are coordinated, it seems very hard to lift any of them out by itself.

We by tradition sees them as 'isolated' things, just as we expect our 'map' to define the velocity.
Giving it a 'meaning' in spacetime.

But to me they are as a 'whole', treated that way you need to look to what really differs in our universe.
There are some things I find truly fascinating.
One is the idea of fractals and chaos mathematics.
Another is macroscopic phenomena as compare to quantum mechanics.

It is very hard for me to see how we get to the phenomena of 'matter' from QM.
But what we do know is that they differ.

I don't agree to time being events (yet:) and I see it all 'gravity' and 'space' (3D) plus times arrow as a direct result from there being matter creation.

We do have a coordinate system macroscopically, it is defined by times arrow and our other three dimensions.

We also have a thing representing energy that we call light.
As far as I know it's the only QM phenomena that we can register by our own un-augmented senses
It is bound to 'c' in our spacetime and follows gravity's geodesics.

So if by definition we accept that motion, gravity, distances and time only is 'relations' giving different results, depending of what frame of reference you are defining yourself and others from then our questions about inflation, as it to me seems to be a quantum mechanic phenomena, loses its 'validity'.

I don't think it ever will be answered from that perspective, inflations 'solution' belongs to QM:s 'rules'.
And there we find all sorts of strange things, entanglement, quantum teleportation, frozen light, etc:)





« Last Edit: 28/01/2009 00:21:23 by yor_on »
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #15 on: 28/01/2009 00:13:22 »
Quote from: DoctorBever
Was he paraphrasing Artemus Ward? ďIt ainít so much the things we donít know that get us into trouble. Itís the things we know that just ainít soĒ
Maybe so; I had never seen the Artemus Ward saying. Will Rogers was an American comic of the 20's.
 

Offline Vern

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Did the universe expand quicker than the speed of light?
« Reply #16 on: 28/01/2009 00:20:37 »
yor_on; I will study that post of yours some more in the morning; I've gone over it three times now and I still don't get a clear picture. I know there is some good stuff there having to do with time and space and I would like to understand it.
 

Offline DoctorBeaver

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Did the universe expand quicker than the speed of light?
« Reply #17 on: 28/01/2009 00:22:50 »
Artemus Ward (real name Charles Farrar Browne) was an American humourist born in 1834.
 

Offline DoctorBeaver

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« Reply #18 on: 28/01/2009 00:23:04 »
yor_on; I will study that post of yours some more in the morning; I've gone over it three times now and I still don't get a clear picture. I know there is some good stuff there having to do with time and space and I would like to understand it.

Same here
 

Offline yor_on

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Did the universe expand quicker than the speed of light?
« Reply #19 on: 28/01/2009 00:25:31 »
It's not complicated.
It just states that 'time' to me behaves differently QM wise:)
And that when 'isolating' forces to see them 'better' we are missing the 'picture'::))

and that's why I really really would like to understand what makes 'matter'.


 

Offline A Davis

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Did the universe expand quicker than the speed of light?
« Reply #20 on: 28/01/2009 00:49:59 »
Quote the idea of light ageing by an unknown mechanism. There is such a mechanism, if a photon from a distant galaxy moves in a curved path it will lose energy didn't Einstien say space is curved.
 

Offline DoctorBeaver

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Did the universe expand quicker than the speed of light?
« Reply #21 on: 28/01/2009 00:52:02 »
Some boffin has theorised that the speed of light has slowed since the Big Bang. Can't think of his name now.
 

Offline A Davis

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Did the universe expand quicker than the speed of light?
« Reply #22 on: 28/01/2009 00:58:01 »
Why would it slow free space shouldn't change.
 

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« Last Edit: 28/01/2009 01:08:02 by DoctorBeaver »
 

Offline A Davis

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Did the universe expand quicker than the speed of light?
« Reply #24 on: 28/01/2009 01:37:39 »
Thinking about it, it may be true the excess radiation would change epsilon'r and mu'r and the speed of light would be faster at the beginnig and slow down after the expansion, but I don't see how this would effect the  path of a photon today the universe must have settled down by now, if not one would be able to measure a change in the background radiation the universe would get colder.
 

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Did the universe expand quicker than the speed of light?
« Reply #24 on: 28/01/2009 01:37:39 »

 

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