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Offline Alan McDougall

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The horizon problem of the universe
« on: 17/11/2008 17:15:23 »
Hi,

1 The horizon problem

OUR universe appears to be unfathomably uniform. Look across space from one edge of the visible universe to the other, and you'll see that the microwave background radiation filling the cosmos is at the same temperature everywhere. That may not seem surprising until you consider that the two edges are nearly 28 billion light years apart and our universe is only 14 billion years old.

Nothing can travel faster than the speed of light, so there is no way heat radiation could have travelled between the two horizons to even out the hot and cold spots created in the big bang and leave the thermal equilibrium we see now.
This "horizon problem" is a big headache for cosmologists, so big that they have come up with some pretty wild solutions. "Inflation", for example.


 

Offline Soul Surfer

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The horizon problem of the universe
« Reply #1 on: 17/11/2008 19:22:44 »
Quantum theory suggests that in some way the universe is simultaneously very large AND very small.  The real answer could be some sort of scale independant theory involving both real and imaginary dimensions.  This could also solve a lot of quantum paradoxes.  It could also open a range of possibilities way beyond some of the wildest science fiction but I expect that quantum censorship and information theory limitations will return us to reality.  In some way microwave engineers are already familiar with the problem.  The phase velocity of waves in a waveguide is in general faster than the velocity of light and approaches infinity as the waveguide nears its cut off frequency however it is never possible to transmit any information using pphase velocity just as it is not possible to transmit information faster than light by using entangled photons.
 

Offline LeeE

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The horizon problem of the universe
« Reply #2 on: 17/11/2008 19:38:35 »
I think you'll find that the universe is thought be to at least 93 billion light-years across, even though it's only ~14 billion years old, because of it's expansion.

The issue with evening out the hot and cold spots only really occurs if it is assumed that the universe had hot and cold spots until some time after the BB and that entropy did not exist until that point.  You can only really apply temperature to matter, but as soon as it started forming, and while the universe was still very small, I would expect entropy to start having an effect - that is, as soon as you had matter thermal differences would start equalising.
 

Offline Alan McDougall

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The horizon problem of the universe
« Reply #3 on: 18/11/2008 09:15:57 »
Lee,

Quote
I think you'll find that the universe is thought be to at least 93 billion light-years across, even though it's only ~14 billion years old, because of it's expansion.

That would make the problem more difficult would it not?.

Entropy is a huge complex unresolved subject on its own, maybe you could start a thread about it. I think I have put in my quota

Who knows the universe might extent outward into infinity

Alan
 

Offline LeeE

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The horizon problem of the universe
« Reply #4 on: 18/11/2008 18:43:46 »
The universe being even bigger than you thought wouldn't make much of a difference if it was already smooth when it was small.
 

Offline Physics Dilettante

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The horizon problem of the universe
« Reply #5 on: 20/11/2008 01:10:45 »
the microwave background radiation filling the cosmos is at the same temperature everywhere.
I thought COBE measurements showed some years ago that there are minor temperature fluctuations in the CMB. Have I misunderstood?
 

Offline LeeE

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The horizon problem of the universe
« Reply #6 on: 20/11/2008 01:24:33 »
I don't think you've misunderstood - there are fluctuations in the CMBR but they're much smaller than some people think they should be.
 

Offline Alan McDougall

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The horizon problem of the universe
« Reply #7 on: 20/11/2008 07:35:16 »
The questions people ask me all the time, if the universe is everything and it is expanding, then into what is it expanding?.

The reply by astrophysicists is "into nothing"!. This is most unsatisfactory and they go away more confused than before.

There is a postulation , that outside of the spacetime fabric of the universe is absolute nothing, a vacuum in the absolute that is infinite in every direction and the universe is encapsulated in an energy like expanding bubble into this primordial, primevil absolute dark nothingness. To me that does not seem to be a such silly idea, in a way it makes sense

Although I admit it is not good physics

Alan
 

Offline Alan McDougall

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The horizon problem of the universe
« Reply #8 on: 20/11/2008 09:48:50 »
Here is another interesting view of the universe and its edge, if it has an edge


http://discovermagazine.com/2008/dec/10-sciences-alternative-to-an-intelligent-creator



If we assume that the Cosmic Background Radiation has a more or less globular bubble form, forming the boundary of our own material universe inside the multiverse, than Andrei Lindes computer simulation of the multiverse has depicted too much universes. See:




http://discovermagazine.com/2008/dec/10-sciences-alternative-to-an-intelligent-creator

If our universe is more or less globular or pear/egg shaped the we should speak of a raspberry or blackberry multiverse, see:
http://bigbang-entanglement.blogspot.com/2007/03/backreaction-lee-smolins-trouble-with.html

http://bp2.blogger.com/_ArDoWzECXSo/RvLKsAmCAII/AAAAAAAAARQ/i9nsuQnCvDw/s1600-h/CMB+WMAP+5x+multiverse_0002.jpg
 

Offline Soul Surfer

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The horizon problem of the universe
« Reply #9 on: 20/11/2008 18:39:32 »
As we are indulging ourselves with a bit of speculation about the actual shape of the universe can I now add my own personal opinions.

My guess is that the universe is most likely to be toroidal with the hole in the toroid very large indeed ie like a hosepipe connected end to end we can only see a tiny part of the circumference of the hosepipe so on the whole it looks flat.

The reason for this is that we are inside a black hole that is rotating in three dimensions a bit like a smoke ring.

The reason why the physical laws are conducive to complexity and life is due to the fact that, like life itself the physical laws, have evolved as the universe cooled down to enable complexity partly because complex recycling processes are favoured as the temperature falls and the uncertainty in behaviour decreases. and partly because we were "seeded" by a black hole forming in a complex universe similar to our own.

Black holes in our universe are one way gateways to other universes that are forming in similar ways to our own and have a similar "size" to our own. This is because the process is essentially scale invariant outside of our universe is an indefinite number of other universes (its turtles all the way down!) So the overall total universe is a constant foam structure of nested black holes extending indefinitely in all dimensions

Getting down to basics space and time consists of a number of complex (probably hypercomplex) dimensions so when a black hole coolapses the space dimensions collapse into time and the time dimensions expand to become space.

All this I think is fully compatible with current scientific thinking relativity cosmology and string theory etc but I am not sure that it can ever be proved.

Looking at the classical relatavistic collapse of a black hole inside its event horizon will I believe reveal hints to this and how we might prove it.
« Last Edit: 20/11/2008 18:46:33 by Soul Surfer »
 

Offline Alan McDougall

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The horizon problem of the universe
« Reply #10 on: 20/11/2008 20:29:31 »
Soul Surfer

Quote
The reason for this is that we are inside a black hole that is rotating in three dimensions a bit like a smoke ring.

The reason why the physical laws are conducive to complexity and life is due to the fact that, like life itself the physical laws, have evolved as the universe cooled down to enable complexity partly because complex recycling processes are favoured as the temperature falls and the uncertainty in behaviour decreases. and partly because we were "seeded" by a black hole forming in a complex universe similar to our own.

Black holes in our universe are one way gateways to other universes that are forming in similar ways to our own and have a similar "size" to our own. This is because the process is essentially scale invariant outside of our universe is an indefinite number of other universes (its turtles all the way down!) So the overall total universe is a constant foam structure of nested black holes extending indefinitely in all dimensions

This is very interesting SS I have also thought that our universe might be a colossal black spewing out and forming our universe.

Black holes might also form less complex univeres, hostile to life, some only existing for a pico second nd less and others eternal and infinite but dark barren an cold. The fundamental constants and even the mathemathics might differ, I once suggested that in another universe "pi" could be exatly "3" and not 3...........? 

And this made me think, could our universe be the opposite in that it is the result of a "White Hole"

I would also like to divert a little and ask how does entropy work in a black hole. How hot is a black hole and can it "reverse entropy" and draw energy into itself from the cold of our universe

Alan
 

Offline Soul Surfer

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The horizon problem of the universe
« Reply #11 on: 20/11/2008 23:01:36 »
Alan A black hole is a black hole and nothing comes out of it other than hawking radiation that is its nature it's what goes on in the "infinite space" that is inside it that is critical and we can never ever see that in the same way we can never ever see outside our own universe in fact we can probably only see a tiny part of that!  It is not possible to answer the middle of your questions because you are not thinking in the right way.  What you are describing is a far to simple and "mystical" approach.  You need to get right down in there with the physics and maths.  I suggest that you read Roger Penrose's book "The road to reality" try to understand it, and think again.

As far as entropy is concerned I am suggesting that it is the interchange between space and time dimensions effectively turning the universe inside out as it collapses through the event horizon that allows entropy to continue increasing without limit and creates this scale invariance.

« Last Edit: 20/11/2008 23:22:55 by Soul Surfer »
 

Offline Alan McDougall

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The horizon problem of the universe
« Reply #12 on: 21/11/2008 08:32:43 »
Soul Surfer

Quote
As far as entropy is concerned I am suggesting that it is the interchange between space and time dimensions effectively turning the universe inside out as it collapses through the event horizon that allows entropy to continue increasing without limit and creates this scale invariance
.

This does not make sense to me, does your postulation suggest a sort of infinitely high state of entropy. If yes where is the infinite energy coming from the drive this infinite machine?

Quote
What you are describing is a far to simple and "mystical" approach.  You need to get right down in there with the physics and maths.  I suggest that you read Roger Penrose's book "The road to reality" try to understand it, and think again

By describing what  I describe by being "far to simple" I find myself in the company of huge intellects like Albert Einstein , he said we should always look at reality through the eyes and questions of a child and try to build on that. his his using of his imagination by "imagining he was riding on a beam of light,is just what I  you and I are doing in this thread.

I can smother the forum with mathematical proofs and suggestions, but there are others on the forum that do not have your level of mathematical insight and they will quickly loose interest and go elsewhere

I have read Roger Pensores books and many others by scientist of equal stature and some disagree with him, he does not have the only take on reality , who knows maybe mine might be more accurate he nevertheless is a remarkable person

Alan

Also no one has been into a black hole and come back to let us what is on the other side. In that I am getting right down to physics and maths and I have never suggested any mystical component on this debate
 

Offline Soul Surfer

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The horizon problem of the universe
« Reply #13 on: 21/11/2008 10:01:43 »
OK here's a bit more of the background thinking without equations

IF  you have read "The road to reality" (which I very much doubt by many of the things you say because it is essentially a mathematics textbook and few questionable theories are presented) you should understand a bit about complex and hypercomplex numbers.  These are vital in understanding the cyclic energy changes in Maxwells equations that describe electromagnetic wave propagation.

Matter also has wavelike properties that can be described in terms of complex numbers and this forms an important part of the mathematics of Quantum theory

The string theorists visualise a universe with many more dimensions than we see  these are seen as being wrapped up very small dimensions (again described using complex numbers)  Complex numbers are one of the best ways of getting rid of nasty infinities in equations when numbers in the denominators of fractions go to zero.

Many theorists describe the universe in terms of information theory.  one of the important properties of information theory is a measure called  time-bandwidth product.  You should also be familiar with Fourier transforms in this context.

This shows that as one thing collapses towards zero another thing is forced to expand.

Now the problem with black holes is that  in our world we see things collapsing to become very small but the energy is getting more and more concentrated and this effectively forces some of the dimensions that have effectively been collapsed to expand and become new space and time dimensions and the process continues.

As for energy one of the weird facts about quantum theory it suggests that if you look at the very small the energy available in the vacuum is almost infinite.
« Last Edit: 21/11/2008 10:09:03 by Soul Surfer »
 

Offline Alan McDougall

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« Reply #14 on: 21/11/2008 10:25:36 »
Soul Surfer,

I did not say that I had read the book by Penrose, I might have, but I have read many articles by this informed physicist

Getting back to entropy, what is the entropic state of a proton?

Alan
 

Offline Alan McDougall

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« Reply #15 on: 21/11/2008 10:53:48 »
Soul Surfer,

Respectfully

Quote
Many theorists describe the universe in terms of information theory.  one of the important properties of information theory is a measure called  time-bandwidth product.  You should also be familiar with Fourier transforms in this context.

This shows that as one thing collapses towards zero another thing is forced to expand

To try and define your argument, are you suggesting that for lack of a better word "Existence' recycles and cycles its self, sort of dying and given new existences perhaps as you stated in new more complex/less universes. Sort of seeded by a black hole giving life to another universe in an everlasting continual process of life and death of universes into the infinite macro  down into the infinitesimal quart realms

Like a seed (black hole) giving existence to a new tree (universe). The next tree (universe) seeded by (black hole) from this a new more complex or slightly changed tree is created and so on recycling energy forever into eternity "Tree =universe, Seed =black hole"
 
Or do you think the universe is a Steady State infinite eternal Universe Fred Hoyle ? I am asking this so that we can debate from the same platform?



Alan
 

Offline Soul Surfer

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The horizon problem of the universe
« Reply #16 on: 21/11/2008 20:12:13 »
Yes BOTH of those Ideas are about right as broad descriptions

It is not the steady state universe as proposed by Fed Hoyle this is because at the time he proposed it. we did not have the knowledge or insight to propose what I am proposing.  It is however logically and philosophically the same thing. It is just that our universe is an evolving tiny part of a continually evolving multiverse that is always substantially the same without beginning or end or scale.

Note that, like the tardis, a black hole is bigger on the inside than the outside because by its nature you can never see its walls.

Your question on entropy is not sensible. Entropy is a property of a large number of interacting elements not a property of a single particle somewhere in space.  (even though a proton is a slightly composite object consisting of three bound quarks)
 

Offline Alan McDougall

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« Reply #17 on: 21/11/2008 20:31:14 »
Soul Surfer


Quote
Your question on entropy is not sensible. Entropy is a property of a large number of interacting elements not a property of a single particle somewhere in space.  (even though a proton is a slightly composite object consisting of three bound quarks

Oh!! yes it is sensible and the energy entropic state of the atom was just what the "Los Alamos Manhattan" scientists had to resolve to create the first fission nuclear bomb

Look it up if you like

But I now know something about your theory and you could be correct

Alan
 

Offline Alan McDougall

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« Reply #18 on: 22/11/2008 07:40:43 »
Soul Surfer,


Reading your posts again leads me to ask you, do you think that size or scale has no real meaning in the grand order of reality. Thus you have universes going down smaller and smaller even near infinitely and the same on an upward scale universe into a greater superuniverse etc.

Thus when we state the unimaginable size of our own universe we are speaking subjectively and relatively

Our universe thus might just be a quantum speck in an unimaginably larger universe and this larger universe only a speck in a much larger universe.

Thus relativity holds true in scale, time and dimensions

Like Russian dolls

Alan
 

Offline DoctorBeaver

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« Reply #19 on: 23/11/2008 13:22:05 »
Quote
If we assume that the Cosmic Background Radiation has a more or less globular bubble form, forming the boundary of our own material universe inside the multiverse

The CMBR is not the boundary of our universe. It marks the epoch of the Last Scattering when radiation & matter de-coupled; coincident with the formation of hydrogen atoms. Prior to that point the universe was a plasma that was too dense for photons to move through. The Last Scattering occurred 300,000 years after the Big Bang; so the universe is considerably larger than the CMBR limit.

Points on the CMBR that are more than 2o apart were not in causal contact prior to the Last Scattering. This means that any fluctuations seen on that scale must have been present in the primordial plasma prior to the Last Scattering.

(I know this has jumped back a way in the thread but I thought it worth mentioning even at this late juncture)
« Last Edit: 23/11/2008 13:33:15 by DoctorBeaver »
 

Offline Alan McDougall

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« Reply #20 on: 23/11/2008 21:24:47 »
DocB,

CMBR is pervades the universe, sort of fog filling all space time

Am I correct?

Alan
 

Offline DoctorBeaver

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« Reply #21 on: 23/11/2008 21:47:01 »
It reaches us from all directions.

I was replying to the assertion that it marks the edge of our universe.
 

Offline Soul Surfer

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« Reply #22 on: 23/11/2008 22:50:20 »
The cosmic microwave background defines the edge of the optically visible universe because before then the universe was opaque. So that distance tells us nothing about the actual physical size of the universe its just as far as we gan see.  Nutrinos and gravitiational waves could in theory panetrate considerably further if we could detect and identify a background ratiation component in these signals.  however it would be very difficult to detect and prove.
 

Offline Soul Surfer

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The horizon problem of the universe
« Reply #23 on: 23/11/2008 23:01:07 »

Oh!! yes it is sensible and the energy entropic state of the atom was just what the "Los Alamos Manhattan" scientists had to resolve to create the first fission nuclear bomb

Look it up if you like


Could you please give me the reference where you learned this.  Please note your original question referred to a single proton  not a uranium atom which is quite a complex structure with quite a lot of potential internal states.  An isolated proton does not have this complexity.

Tho talk about the entropy of an isolated system of particles it is necessary to  know the number of particles the amount of space they occupy potential ststes they may occupy within that space and the reasons why (iter atomic forces etc) they may occupy one configuration rather than another.
 

Offline DoctorBeaver

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« Reply #24 on: 23/11/2008 23:14:21 »
The cosmic microwave background defines the edge of the optically visible universe because before then the universe was opaque. So that distance tells us nothing about the actual physical size of the universe its just as far as we gan see.  Nutrinos and gravitiational waves could in theory panetrate considerably further if we could detect and identify a background ratiation component in these signals.  however it would be very difficult to detect and prove.

Quite so; but the assertion I was replying to was that the CMBR marks the edge of "our material universe", which it does not.
 

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