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Francois
2005-Jan-21, 03:17 PM
According to many articles and documentaries it is possible to detect microwave radiation (and other types?) from shortly after the Big Bang. I was wondering how this is possible - did the matter that spawned planet Earth travel so much faster than the speed of light to reach it's current positioin in time to allow the birth of life so that humans could catch the incoming radiation? Or am I missing something?

Svemir
2005-Jan-24, 07:45 AM
This is a question that really is unanswered by BB theorists.
It's logical. It's beautiful. It reveals a big discrepancy in a BB model.
According to the BBT, light-photons were free from ca. 300.000 y. "after" Big Bang.
Since Universes' rate/speed of expansion is not c and actually in a patched model is not even constant, using the idea of the very same model of the Univers that has curvature we come to the conclusion that light must be bended from the boundaries of the Univers (regardles of it having boundaries).
The other possibility is that light just stays and accumulates there, close to the boundary.
Following that logic some astronomers began to look after the paterns in the sky, because the light from the first galaxies should be bended (or travelled the entire univers) and we should see the same picture in different directions.
http://www.mathsci.appstate.edu/~sjg/class.../universe3.html (http://www.mathsci.appstate.edu/~sjg/class/1010/wc/geom/universe3.html)
http://www.cs.appstate.edu/~sjg/class/1010...initespace.html (http://www.cs.appstate.edu/~sjg/class/1010/wc/geom/finitespace.html)

antoniseb
2005-Jan-24, 02:36 PM
Originally posted by Francois@Jan 21 2005, 03:17 PM
did the matter that spawned planet Earth travel so much faster than the speed of light to reach it's current positioin in time to allow the birth of life so that humans could catch the incoming radiation?
There was a period of time when the universe somehow got to be very large in a very short time [usually referred to as the "Inflation Era"]. It is safe to say we do not know the cause or physics that made inflation possible, and in fact if there's some other explanation that describes the phenomena discovered, it will be embraced, but so far none do. Inflation was over in what would seem to us to be an instant.

Following the inflation era was the era of cosmological expansion we observe now, with the laws of physics as we know them now, including no violation of the speed of light.

GOURDHEAD
2005-Jan-24, 03:07 PM
The material quoted below is excerpted from the links provided.


There are infinitely many possible topologies for a finite hyperbolic three-dimensional universe. Their rich structure is still the subject of intense research and the classification is still an open problem today. One example, discovered by Jeff Weeks, may be constructed by identifying pairs of faces of an 18-sided polyhedron. How can one generate a large set of the infinite possibilities?



The first bucket is at rest relative to distant galaxies, so its surface remains flat.* The second bucket spins relative to those galaxies, so its surface is concave. If there were no distant galaxies, there would be no reason to prefer one reference frame over the other. The surface in both buckets would have to remain flat, and therefore the water would require no centripetal force to keep it rotating. In short, it would have no inertia. Mach inferred that the amount of inertia a body experiences is proportional to the total amount of matter in the universe. An infinite universe would cause infinite inertia. Nothing could ever move.

In addition to Mach's argument, there is preliminary work in quantum cosmology, which attempts to describe how the universe emerged spontaneously from the void. Some such theories predict that a low-volume universe is more probable than a high-volume one. An infinite universe would have zero probability of coming into existence [see "Quantum Cosmology and the Creation of the Universe," by Jonathan J. Halliwell; Scientific American, December 1991]. Loosely speaking, its energy would be infinite, and no quantum fluctuation could muster such a sum. If the BB caused spacetime to come into existence, there was no void pre-BB.

At rest with respect to distant galaxies is difficult to demonstrate or even argue. Both buckets are spinning on the surface of the Earth which is revolving around the sun which is revolving (not free of sinusoidal variations with respect to the MW's equator) around the center of the MW, which is performing some motion through the local group etc., etc.,

But if the universe only aproaches an infinite size, then its probability of coming into existence only approaches zero. How could we ever discern the difference. Once you employ a quantum fluctuation to get one AMU, what constrains the process to generate less than an unbounded number of them. Let's just fiat it into existence commensurate with all these other epicycles.

Francois
2005-Jan-24, 04:52 PM
Originally posted by antoniseb@Jan 24 2005, 04:36 PM
There was a period of time when the universe somehow got to be very large in a very short time [usually referred to as the "Inflation Era"]. It is safe to say we do not know the cause or physics that made inflation possible, and in fact if there's some other explanation that describes the phenomena discovered, it will be embraced, but so far none do. Inflation was over in what would seem to us to be an instant.

Following the inflation era was the era of cosmological expansion we observe now, with the laws of physics as we know them now, including no violation of the speed of light.
Yes, I have read about Inflation Theory, and its ramifications are quite interesting. Now that you've mentioned it, I suddenly started to wonder about it. It's quite strange that scientists would actually accept a theory such as Inflation Theory that basically introduces an element of magic (unknown physics other than what we experience today). This is unlike normal science where everything should be explained through reasoning about observations - eliminating explanations using magic or devine creation.

Even if Inflation Theory and its unknown physics holds to be valid, then I think that my question is still unresolved by it. At the instant just after inflation was completed, all matter in our universe was in plasma form, not true? From that point onwards, radiation was emmitted in all directions. After a while things started to cool down and stars were formed. I don't see then how we can then observe that radiation from way back then.

The bending of light at the universe boundaries might provide a suitable explanation, but I have not checked it out yet. It does, however, seem to me that some fanciful conjuring might be involved.

Until someone can provide more insight, I would like to pose a further question: has the Big Bang Theory and its spin-offs such as Inflation Theory ever been used to explain anything for which we can find practical use? If not, is it then not just a big waste of time? I would guess that we might even be wrong in assuming there *is* an origin for the universe.

antoniseb
2005-Jan-24, 05:03 PM
Originally posted by Francois@Jan 24 2005, 04:52 PM
At the instant just after inflation was completed, all matter in our universe was in plasma form, not true?
You could call it plasma, but it was vastly more energetic than a plasma. It is likely that there were still free quarks and other particles that are never seen anymore, because they are too massive and decay in to short a time; perhaps the supersymmetric family that might have been the ancestors of the hypothesized "Neutralino" that could be a main component of the Cold Dark Matter we observe gravitationally.

Concerning inflation, it explains what we see, even if we do not understand why. Some day, we will have an explanation for it, but I think for the next century or so, we are still just collecting facts. Not having all the facts does not mean that inflation shouldn't be suggested. It just means we are refining what we know about something mysterious. This IS science as it should be. If we already knew the details, it would be engineering.

peassens
2005-Jan-25, 10:38 AM
Originally posted by Francois+Jan 24 2005, 04:52 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Francois @ Jan 24 2005, 04:52 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-antoniseb@Jan 24 2005, 04:36 PM
There was a period of time when the universe somehow got to be very large in a very short time [usually referred to as the "Inflation Era"]. It is safe to say we do not know the cause or physics that made inflation possible, and in fact if there&#39;s some other explanation that describes the phenomena discovered, it will be embraced, but so far none do. Inflation was over in what would seem to us to be an instant.

Following the inflation era was the era of cosmological expansion we observe now, with the laws of physics as we know them now, including no violation of the speed of light.
Yes, I have read about Inflation Theory, and its ramifications are quite interesting. Now that you&#39;ve mentioned it, I suddenly started to wonder about it. It&#39;s quite strange that scientists would actually accept a theory such as Inflation Theory that basically introduces an element of magic (unknown physics other than what we experience today). This is unlike normal science where everything should be explained through reasoning about observations - eliminating explanations using magic or devine creation.

Even if Inflation Theory and its unknown physics holds to be valid, then I think that my question is still unresolved by it. At the instant just after inflation was completed, all matter in our universe was in plasma form, not true? From that point onwards, radiation was emmitted in all directions. After a while things started to cool down and stars were formed. I don&#39;t see then how we can then observe that radiation from way back then.

The bending of light at the universe boundaries might provide a suitable explanation, but I have not checked it out yet. It does, however, seem to me that some fanciful conjuring might be involved.

Until someone can provide more insight, I would like to pose a further question: has the Big Bang Theory and its spin-offs such as Inflation Theory ever been used to explain anything for which we can find practical use? If not, is it then not just a big waste of time? I would guess that we might even be wrong in assuming there *is* an origin for the universe.


[/b][/quote]
The Big Bang is not based on facts. Some people in Physics and Astronomy belive in &#39;t as in a religion &#33;...

In about hundred years they will laugh at us &#33;..

antoniseb
2005-Jan-25, 04:03 PM
Originally posted by Riverfront@Jan 25 2005, 10:38 AM
The Big Bang is not based on facts. Some people in Physics and Astronomy belive in &#39;t as in a religion
That&#39;s kind of a strong statement. Is the existence and observed nature of the CMB not a fact? Is the red-shift-distance relationship not a fact? Is the chemical evolution of the galaxies not a fact? is the maximum age of any known star or cluster not a fact?

I think you don&#39;t actually mean this, and you&#39;re just trying to stir up some trouble.

peassens
2005-Jan-26, 08:59 AM
Originally posted by antoniseb+Jan 25 2005, 04:03 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (antoniseb @ Jan 25 2005, 04:03 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Riverfront@Jan 25 2005, 10:38 AM
The Big Bang is not based on facts. Some people in Physics and Astronomy belive in &#39;t as in a religion
That&#39;s kind of a strong statement. Is the existence and observed nature of the CMB not a fact? Is the red-shift-distance relationship not a fact? Is the chemical evolution of the galaxies not a fact? is the maximum age of any known star or cluster not a fact?

I think you don&#39;t actually mean this, and you&#39;re just trying to stir up some trouble. [/b][/quote]
Not all points are facts &#33;.. And certainly not the Big Bang, Inflation, Red shift distance..
Personally i can only underwright your point about Chemical evolution in certain ways.

What i mean to say is with the tools we have at the moment (Einstein and Planck) we can only speculate what&#39;s really happening in the Universe, maybe we are seeing far less of the universe (13 light years ???) then where thinking at this point in time. At the beginning of the 20 th century Astronomers and Physicists thought they had seen it all.

But thit they really ?.... no they didn&#39;t...

antoniseb
2005-Jan-26, 01:02 PM
Originally posted by Riverfront@Jan 26 2005, 08:59 AM
maybe we are seeing far less of the universe (13 light years ???) then where thinking at this point in time.
I&#39;m assuming you meant 13 billion light years here.

My point is that the Big Bang IS based on facts. While there may be more facts out there which haven&#39;t been observed yet, and which may change some of our model, the current model is based on facts. Redshift-distance BTW, is a fact. Big Bang & Inflation are part of the model based on facts, but not themselves facts.

peassens
2005-Jan-26, 01:19 PM
Originally posted by antoniseb+Jan 26 2005, 01:02 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (antoniseb @ Jan 26 2005, 01:02 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Riverfront@Jan 26 2005, 08:59 AM
maybe we are seeing far less of the universe (13 light years ???) then where thinking at this point in time.
I&#39;m assuming you meant 13 billion light years here.

My point is that the Big Bang IS based on facts. While there may be more facts out there which haven&#39;t been observed yet, and which may change some of our model, the current model is based on facts. Redshift-distance BTW, is a fact. Big Bang & Inflation are part of the model based on facts, but not themselves facts.


I assume 13 billion light years, yes.

Big Bang & Inflation are part of the model based on facts, but not themselves facts.

Precise that&#39;s what i mean.
The one thing i like best about Physics Astronomy, that it leave&#39;s space for open minds and different interpatations. There is much to reveal and much more to prove in Physics and Astronomy.

(sorry English is not my mother language)


[/b][/quote]
I assume 13 billion light years, yes.

Big Bang & Inflation are part of the model based on facts, but not themselves facts.

Precise that&#39;s what i mean.
The one thing i like best about Physics Astronomy, that it leave&#39;s space for open minds and different interpatations. There is much to reveal and much more to prove in Physics and Astronomy.

(sorry English is not my mother language)

antoniseb
2005-Jan-26, 03:03 PM
Originally posted by Riverfront@Jan 26 2005, 01:19 PM
Big Bang & Inflation are part of the model based on facts, but not themselves facts.
Precise that&#39;s what i mean. (sorry English is not my mother language)
No apology needed on the language.
Your original post said the Big Bang was not based on facts. Now, however, we agree. The Big Bang and inflation are not facts, but it are based on facts.