2006-Oct-10, 01:00 AM
As a tribute to John Mather and George Smoot, the two leaders of the
Cosmic Microwave Background Explorer (COBE) satellite science team,
and winners of this year's Nobel Prize for Physics, we head back to
the beginning of everything... ...
Read the full blog entry (http://www.astronomycast.com/cosmology/the-big-bang-and-cosmic-microwave-background/)
2006-Oct-13, 12:52 PM
an interesting podcast - but naturally very generalised - perhaps if you get the chance do a follow-up (ie podcast 5, the industrial strength version for nerds), you could go into more detail about the events leading up to the last scattering surface; it would answer a lot questions that seem to recur on the forum.
Nothing too scary; just the simple history and mainstream views - Hawkings proposal of a blackhole, GUT theories, Andrei Lind/Andrei Sakharov antimatter/matter, symmetry breaking, inflation, etc...
2006-Oct-13, 02:33 PM
Our next podcast is going to continue on with the Big Bang, and explain additional lines of evidence to support the theory. If we have time, we'll include a few additional variants on the theory, but we'll probably tackle those for future shows. I'd rather have a whole show on inflation, and handle it properly.
2006-Oct-25, 07:36 AM
Please be skeptic if you must but these are solely alternative views, perhaps it won't be disregarded.
"Big Bang" Theory
Copyright © John Dobson
You have to have at least graduated high school to believe in the
"Big Bang" Theory, because in high school three things happen:
First, you're persuaded the impossible is possible,
Then you become persuaded the possible is probable,
Finally you become persuaded the probable is certain.
It takes at least 3 years for this.
Children will never buy everything came from nothing.
A Brief History Of Cosmology
Copyright © 2002 John Dobson
How scientists, ancient and modern, have viewed the Universe
Newton had a cosmological problem introduced by combining his universal gravitation with his inverse square law. In order to avoid infinite gravitational problems, Newton's Universe had to be finite in an infinite ocean of space. That is, it had to have a center. But that contradicts the cosmological principle that the Universe should look the same from any position.
Then the astronomer Seeliger pointed out that the Universe could still be infinite if we allow that over very large distances the gravitational attraction between bodies falls off more rapidly with distance than with Newton's inverse square law. (This suggestion of Seeliger's is the famous cosmological term Einstein used and later regretted.)
In order to preserve the notion that "there exists an average density of matter in the whole of space which is everywhere the same and different from zero," and to preserve the notion "that the magnitude of space is independent of time," Einstein introduced Seeliger's cosmological term, "...a term which was not required by the theory as such nor did it seem natural from a theoretical point of view."
Then, in the 1920s, the Russian mathematician Alexander Friedman pointed out that we could still have an infinite Universe, with an average density different from zero, and yet get rid of Seeliger's cosmological term if we allow that the magnitude of space might not be independent of time, that is, if we allow that space might expand.
This predicted expansion, which was confirmed observationally by Hubble and others, implied both an "origin" and a "creation" for the Universe, and gave rise to the Big Bang models. But how could the Universe come out of nothing. What drives the expansion? And why should the Universe expand at the escape velocity? And there was even some doubt that the Universe could be older than the stars.
In the 1940's Bondi, Gold and Hoyle, in England, pointed out that we could get rid of the "origin" problem if we allow that creation is continuous, that is, that hydrogen is created throughout the Universe at a rate to match the expansion.
That gave rise to the Steady State models, which hold to the perfect cosmological principle, that the Universe should look the same not only from any place but also at any time. But where does the "new hydrogen" come from? And from where do we get the 3K microwave background radiation discovered by Penzias and Wilson which the proponents of the Big Bang took as the clinching evidence for their model?
Although the Steady State models got rid of the "origin" problem, they did not get rid of the "creation" problem. But we can get rid of the "creation" problem as well as the "origin" problem by allowing that the particles might recycle from the border of the observable Universe imposed by the observed expansion. (Actually, it is the redshift itself that imposes the border, rather than our interpretation that the redshift is due to an expansion.)
Since the spectral lines of the radiation coming from very near that border appear gravely redshifted, it follows that, as seen by us, the particles giving rise to that radiation are of very low energy and very low mass. And that low mass has two very interesting consequences.
First: Since radiation going through a field of low mass particles will be thermalized to 3K by being so often picked up and reradiated, we have a possible alternative explanation for the observed microwave background radiation discovered by Penzias and Wilson, and interpreted by some as the "echo" of the Big Bang.
Second: If the mass of the particles is low, their momentum, and therefore our necessary uncertainty in that momentum, will also be low. But, by Heisenberg's uncertainty principle, if our uncertainty in the momentum approaches zero at that border, our uncertainty in the position of the particles there must approach totality. And that allows the particles to recycle from the border. (Also, as the mass of the particles goes down, their electrical size must increase, rendering the formation of atoms and molecules less likely.)
Now if the particles can recycle, by tunneling, from the border of the observable Universe, we can get rid of the "creation" problem as well as the "origin" problem.
Is there any observational evidence that material is thus recycling from the border? There is. The Hubble Space Telescope supplied evidence that there are some nine or more clouds of hydrogen between the quasar 3C273 and ourselves. And it is difficult to believe that such clouds could have survived for some fifteen thousand million years without condensing into something we could see. Measurements with the Hubble Space, Telescope also indicate that there is more than enough hydrogen in the great inter galactic voids to make all the known galaxies. And finally, the slowing down of the expansion rate predicted by the Big Bang has not been confirmed.
John L. Dobson
Is there anything which this recycling model predicts? There is. It predicts that the Universe must be built on frustration or it couldn't go on like this. (This is a steady state model.)
The streams and rivers are trying to get to the center of the Earth, but the rocks are in the way, and the streams get frustrated. The rocks are trying to get to the center of the Earth, but the iron of the Earth's core is in the way, and the rocks get frustrated. The iron is trying to fall into the Sun, but its inertia gets in the way, and it coasts around the Sun. The Sun is trying to fall into the center of the Galaxy, but its inertia gets in the way. The Galaxy is trying to merge with all the rest of the matter in the observable Universe, but the cosmological expansion gets in the way. And the cosmological expansion is trying to reduce the density of the observational Universe, but the recycling is in the way.
If it could be shown that the Universe is not built thus on frustration so that it could go on like this, all steady state models would be dead.
John L. Dobson
October 10, 2002
Of course, there is still the question as to why we see hydrogen falling together by gravity to galaxies and stars. Why hydrogen? Where does the gravity come from, and the inertia, and the electrical charge?
That problem was handled by some ancient physicists whose word for the Universe was Jagat, The changing. But they were smart enough to see that since change is seen against the changeless, there must be something underlying the changing Universe that is not in space and time, and therefore undivided, infinite, and changeless. There question then was: "How do we see change?" And they said, "It can only be by mistake." So they studied mistakes, and they said that if one mistakes a rope for a snake, the length and diameter of the rope must show in the snake. That is, the undivided, the infinite and the changeless must show in our physics. That might explain gravity, electricity, and inertia. But why, if we see a duality or a plurality, doesn't the undividedness show through and shut it down? Perhaps it is because we see an electrical duality within a gravitational plurality, and they keep each other up. This wouldn't be interesting, of course, if it didn't show up this way in our physics, but it does.
The undividedness can close down the duality of the electron and the positron, because neither of them is wound up on the gravitational plurality. But it cannot close down the duality of the electron and the proton in the hydrogen atom, in spite of the enormous electrical attraction between them. That's because the proton is tied into the gravitational plurality whereas the electron is not. (That's Heisenberg's uncertainty principle.) And particles with a half unit of spin (Fermi particles) cannot occupy the same energy state and collapse the neutron starts. (That's Pauli's Verbot.)
Those ancient physicists saw that this Universe is made out of energy which they saw as the underlying existence showing through. Although they failed to mention nuclear energy, they listed five forms of energy perceivable by our five senses, gravity with the ear (the saccule), kinetic energy with the skin (as temperature), radiation with the eye, and electricity and magnetism with the tongue and the nose (salty and sour are electrical sensations, and the nose reads molecular structures tied together by magnetic bonds). They even saw the identity of mass and energy, which we didn't get from Einstein till 1905. Mileva Einstein was a close friend of Nikola Tesla who got that idea from Swami Vivekananda, and he got it from the Sanskrit language. All this is built into that language, and anyone could have seen it. Why me? I am not a Sanskrit scholar by any stretch of the imagination; however, I have been exposed to Sanskrit over most of the last century.
If the changeless didn't show through in our physics, we wouldn't have inertia. If the infinite didn't show through, we wouldn't have electricity. And if the undivided didn't show through, we wouldn't have gravity and the attraction between opposites. Also, if the duality didn't keep up the plurality, we wouldn't have the atomic table. And if the plurality didn't keep up the duality, we wouldn't have atoms at all. That's how I see it.
John L. Dobson
October 11, 2002
2006-Nov-18, 07:38 PM
Megan and I loved this show. We ran through nearly half a pack of construction paper drawing out ideas, but no ground breaking ideas came through. :D
BTW Dr. Gay don't worry about explain this to an 8 year old. Explaining these shows is my job, and we have a blast doing. :lol:
2007-May-22, 01:03 AM
On the little image for this show it made it look like the expansion phase lasted
about 400,000 years and appears to have finished with a universe already
pretty large comparatively on the graphic
But I was not sure I understood it.
As per the graphic - The inflation lasted 400,000 years ?
Was the inflation at the speed of light ?
So the early universe was 400,000 light years in size ? ( small ? )
2007-May-29, 07:28 PM
In the creationist community I have heard the Big Bang as being "An explosion in a print shop"
Is this an over simplification or a total misunderstanding of the Big Bang theory?
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