On April 25, 2002, SCIENCE published a research paper online in its online journal, SCIENCEXPRESS [10.1126/science 1070462]. The research paper is entitled *A Cyclic Model of the Universe,* by Paul J. Steinhardt(1) and Neil Turok(2). SCIENCE has followed through by making it the focus for its present issue of 24 May 2002.

When I first read the research paper I thought that it was perhaps too controversial for SCIENCE to be willing to publish in print. But SCIENCE has surprised me by placing the topic as the illustration on the cover of its 24 MAY 2002 issue, not only having the Research Article published in this issue, but also including a number of other articles explaining it to people who are not in the fields of Astrophysics or Cosmology.

The research (which is entirely the result of a large, interesting cosmological computer program) is controversial in that it rules out the Big Bang (with all of the difficult problems associated with it, such as a beginning) and the Big Crunch, and proposes an oscillating universe which goes through expanding and collapsing phases ad infinitum. Search for it in your public library. If it does not turn up there, I would think that all university science libraries would include SCIENCE on its list of scholarly periodicals.

Anyway, SCIENCE surprised me by making it the focus of its present issue of 24 May 02. I shall be interested in the professional scientific reaction to it. However, the subscribers to SCIENCE have already had a chance to examine the research article.

If you are interested, find it in a science library. Perhaps your public library has a subscription to SCIENCE. It might take a few weeks to reach the magazine racks in the library. I read it online, but it sometimes takes a couple of weeks for the print version to reach my mailbox.

Anyway, this issue (24 MAY 02) of SCIENCE ought to raise a lot of interesting mail (letters to the editors of SCIENCE) in the coming weeks.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Actually, Paul Steinhardt just gave a talk at Fermilab a few weeks ago on the Cyclic Universe. It does solve some of the current problems with the big bang and actually requires dark energy. Dark energy is sort of tacked onto the big bang to explain current observations.

It also keeps entropy increasing from one universe to the next, so there is never a decreasing entropy problem.

It has definitely been receiving some attention in the theoretical astrophysics community.

Rob

Hale_Bopp (Rob):

Thank you for the good information about the Steinhardt and Turok article. I had wondered how the accelerating universe would fit into this scenario and am comforted to know that it applies here. I hope that there will be some observational method for determining this theory outside of a computer program. I, myself, like theories to have some basis in the real universe (such as the CMBR was seen as a remnant of the Big Bang). I always enjoy finding out new ideas, but I like more than a theoretical basis for understanding them.

I am not a scientist, so I shall certainly let the scientists battle over this without my two cents worth of ignorance interfering.

Thank you for the information. It is exciting. SCIENCE must think well about it. If it is valid, this will throw a lot of loving ideas out the windows and into the trash bins.

Probably I will remain stuck in the middle between two great ideas. Quite a predicament. I hope I do not get *squished*!

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

This model was discussed on NPR on Science Friday, 05-17-02. Unfortunately I missed the part where the method of testing the theory was discussed. I really wanted to know how you could test for something so strange as a parallel universe. I'll have to read more about this.

If you missed it, you can listen to the Science Friday discussion of the cyclic universe here.

http://search.npr.org/cf/cmn/cmnpd01...7/2002&PrgID=5

I missed it and plan to check it out today!

Rob

beskeptical and Hale_Bopp:

Thank you for the information and/or the link to the audio. It cut out on the player part of the way through, so I did not hear the complete program.

I have the articles and research papers in SCIENCE online for 24 May 2002 and will read further about this interesting topic.

However, just like the other scenarios, most of the story is long into the future and at present all we can view is the accelerated expansion. I have always liked theory linked to observation. Computer programming is fine, so long as it can show something which can be partially checked.

Incidentally, for a long time I thought that we lived in a repeating universe of Big Bangs and Big Crunches (but that universe had a deceleration which we do not have as yet. We used to think that there was a deceleration, but the Supernova Cosmology Project and the High-Z Supernova Search Team changed that in the NATURE Letter of 1-1-98 and SCIENCE awarded the Accelerating Universe the Discovery of the Year in its issue of 12-18-98.

I do not count computer programs as observation, so I am a real old fogey. However, I will keep the subject open for further explanation.

SCIENCE for 24 May 2002 certainly gave it the *full treatment* and I will let the real cosmologists (both theoretical and observational) tell me what it is all about. At least, it is a wonderful surprise.

I feel a little sorry for the folks whose research and life work has gone down the drain (if only temporarily).

Thanks again, both of you.

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(Armchair cosmologist since 3 years of age.)

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Well, truth be told, no one really knows proof positive for sure what the history of the universe is. The Big Bang, though the most widely accepted theory, is still a theory. That leaves room for growth, improvements, and maybe even new interpretations of the data as more data is discovereda nd processed. That's what makes science so much fun - you get to redefine conventional knowledge [img]/phpBB/images/smiles/icon_biggrin.gif[/img] !

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"As I lay beneath the Southern Cross, the stars tell more than I could" . . . David Meece

Truth be told, but theories in science are *Big Stuff* and are right up there at the top to explain the Laws of Science. There is nothing higher in science to go than to formulate and prove theories from the given observations. The Big Bang is VERY BIG STUFF. I think that the new Brane inspired theory of the Universe is mostly based on computer simulations and hopefully a lot of it relates to observations (as I have read it does). It is nice to have a new game in town but it is hardly going to supplant the Big Bang easily. There are a lot of steps to be made before that happens.

I happen to like Superstring Theory and M Theory which is an extension of Superstring Theory. I have attended symposiums about M Theory.

But the Big Bang is going to be a difficult theory to supplant.

Science does not involve itself with *Proof Positive* about anything. Proofs are steps toward making theories. Science does not go further than theories. Laws are the discovered information and facts out there in the World and in the Universe to be observed and from which the wonderful scientific theories are formed.

The Big Bang has a lot of observational support, so I do not think that it will hit the dust bin of science easily.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Emphasis added

You seem to have made the common layman's mistake of confusing "theory" with "hypothesis".
When a layman says "I have a theory", he means "this is my guess".
To a scientist, this is known as a "hypothesis". A theory is a hypothesis that has been tested against the known data and has:
1) Been shown to explain the data.
and
2) Make testable predictions about future observations.

In short, a theory is much more than a SWAG*

*Scientific Wild @$$ Guess

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When all is said and done - sit down and shut up!

<font size=-1>[ This Message was edited by: Kaptain K on 2002-05-30 00:10 ]</font>

Kaptain K:

The following was written by nebularain and not by me.

Quote:
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The Big Bang, though the most widely accepted theory, is still a theory.

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I was quoting from a post by *nebularain* at the beginning of my own post in question and was making certain that *still a theory* was in no way verging on the Creationist *only a theory* statements, because theories, in fact, are big stuff in science. Actually, the term Big Bang or big bang, if you prefer is not a scientific term but a popular term, because it hardly describes the beginning of the universe (as associated with the name *Big Bang*). I have read in a number of places that the Big Bang was neither big nor a bang. What the Big Bang is called is not even a *big deal* with me.

Whatever you wish to call it, theory or hypothesis, the Big Bang (or big bang) has been the main cosmological idea going around which attempts to describe the beginning of our universe. This new idea will be interesting to watch develop.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

ljbrs,

I was replying to nebularain. I am quite certain that you know the difference between theory and hypothesis.

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

When you reply with quote, the BB software inserts a line (I made it in bold, above) that includes the author as well as the date and time. That avoids some of the confusion.

Kaptain K:

Of course! It must have been quite late and my brain was turning to mush. My presbyopia does not help (3 sets of reading glasses for 3 types of situation - computer at work, computer at home, regular reading). I cannot read easily with bifocals. Using them at a computer is beyond the pale!

Excuses, excuses!

Incidentally, SCIENCE for 24 May 2002 was in my mailbox tonight! It is loaded with all kinds of articles about the research discussed in this thread. The Research Article has been repeated for readers who do not have a subscription (which includes online viewing). There go my rest periods, including sleep, perhaps!

I will take it all in gradually. It will be there online and in the paper form for a long time. It is summertime and getting out to my astronomy club's observatory is of first importance. Cosmology can wait. Perhaps by the time I get to the point where I begin to understand it, there may be other new theories to take its place.

Sorry about being jumpy about *a theory* references to science. I should have known that you, most particularly, knew when something was being quoted in a post. Perhaps it is a female trait I should watch more closely to keep it from rearing its stupid head.

Now to put my DUNCE CAP back on properly. I think that it is rather attractive...

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Grapes of Wrath:

[Quote]
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Quote:
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On 2002-05-31 00:24, Kaptain K wrote:
I was replying to nebularain.

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When you reply with quote, the BB software inserts a line (I made it in bold, above) that includes the author as well as the date and time. That avoids some of the confusion.

Thanks. Incidentally, I am glad that I started this thread. Some of my favorite writers have responded (the ones interested in real science and who know a lot more about it than I do). I always enjoy such posts.

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You can see that I like smilies...

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Sorry - I didn't mean to come off sounding like that. [img]/phpBB/images/smiles/icon_eek.gif[/img] [img]/phpBB/images/smiles/icon_redface.gif[/img]

I do know the difference between a hypothesis and a theory, and I do know how substantial theories are in science. (I have a bachelor's degree in biology, after all.) Neither was I trying to bash the "Big Bang" theory, nor would I try - cosmology still confuses me too much to try to argue its points! I just know from things I have read that the "Big Bang" doesn't answer everything (at least the "skeptics" are saying that; I don't know if the "believers" are saying that), and if that is true, then that leaves room for alterations, whether it be in the theory or in our understanding of the theory or in our understanding of the ancient universe or something else. I had read a book last summer titled "Scientific Blunders" (sorry, I forgot the author's name). One of the major causes of some of these blunders was to hold too fast to an interpretation of how things are despite any inconsisitencies it may have or how strong the contradictory evidence was. Just look at how many things we believe differently now than we believed twenty years ago. I have come to learn through my studies that until all the questions are answered, it is wise not to hold too tight to a theory as if it were law lest you come out looking like a fool, as many in the past have done. We are taught, after all, to say, "The experiment supports the hypothesis," not "The experiment proves the hypothesis." That is what I meant.

If future discoveries further support the "Big Bang" theory - great. If it becomes less supported, or something else becomes more supported - great, too. We've learned things in the process of questioning and discovering. Isn't that the goal? (I just hope someone can discover a way to explain it all in a way that doesn't leave me feeling more confused!)

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"As I lay beneath the Southern Cross, the stars tell more than I could" . . . David Meece

Scientific theories all are transitory (including in biology). There is no such thing as a scientific fact. However, variations on the Big Bang (as it was named by its most famous detractor, the late Fred Hoyle) is still the main theory in Cosmology. Then again, new observations lead to new explanations for the differences. Can you imagine what would happen to science if nothing new came to drive out old ideas? There would be no scientific jobs, for one, except those which would catalog the discoveries of the past. New discoveries make for new science. These new ideas are attempting to account for some rather recent discoveries (such as the accelerating universe).

I, myself, not being a scientist, do not attempt to make science. I will let the scientists fight it out among themselves without my input. So I avoid *fringe* science, unless it is analyzed by a respected scientist (such as Ned Wright of UCLA at his well-known Cosmology Tutorial):

http://www.astro.ucla.edu/~wright/cosmolog.htm

He takes on a number of questionable ideas at this site in addition to explaining many other new ideas coming into the field. I wonder what he is going to do with this new *Brane* cosmological theory. It was just printed in the 24 May 2002 issue, along with many explanatory articles. If either SCIENCE or NATURE takes it seriously, I do so also.

Incidentally, our being confused by a theory does not make it incorrect. It only means that we have a lot of study ahead of us. I leave the decisions up to the scientists. Peer review will decide everything.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

It not only 'leaves room' for alterations, it demands it. Made a post on the old BABB about the "Ekpyrotic Universe" just a little over a year ago. (Do me get any points for that?) Was so excited by it's potential, just couldn't wait till the heavies here, the ones that really understood the ramifications, waded into it. Didn't really get much of a response, and even made a couple more feeble attempts of baiting them, before me gave up. Well, duh.., those guys at the time, were astronomers, not cosmologist. What BB is this, again? They tended to be more pragmatic, physical proof types of scientists, than theorist, in their search for reality.
From that Brane Storm, we have now moved to the Cyclic Model of the Universe. Pretty fast for a theory, that could upset and replace, the accepted model of cosmology for the past forty or more, years, the big bang theory. And like a Phoenix, a new and improved "Steady State" model for this universe, that we find ourselves within, rises. Which believe was the estabished theory, the Big Bang theory usurped. The scientic method is self-correcting, that is it's wonder and strength. Still it is exciting to witness the possibility of such a major upheaval within the ivory towers. [img]/phpBB/images/smiles/icon_cool.gif[/img]

NubiWan:

The new theory has yet to run the gauntlet of the community of Astrophysicists and Cosmologists. I will wait for peer review to run its slow course before I will be an unqualified believer. The Brane universe incorporates the accelerating universe which has been substantiated by observation by the Supernova Cosmology Project and the High-z SN Search Team, so there is one plus in its favor. It makes use of dark matter and dark energy in a way that was not considered before. However, there is no possibility of observation of this new type of universe outside of computer programs. This does not make it wrong. This only makes it as yet unconfirmed by the peers in the scientific community.

It is an interesting theory. I wish it well. However, I am certainly not a *peer* and will not be among the judges.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Non-peer to non-peer, "possibility" is the operative word, here. [img]/phpBB/images/smiles/icon_wink.gif[/img]

NubiWan:

Non-peer to non-peer I will leave all of this up to the *peers* to fight it out among themselves. Sometimes it is more fun being a spectator than a participant. You do not need to suffer from embarrassment if and when your *wonderful theory* falls flat on its face. (I am not here saying that this theory is going to suffer that flattened-face ending.)

I enjoy watching the show from a polite distance.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.

Andrei Linde (who originated chaotic inflation theory) has been very critical of the cyclic model. He has a new paper which is a very interesting read. Although I originally thought he was being overly protective of his own theory, he makes some excellent points in this new paper.

He points out that the cyclic model has had to be revised a number of times already to fix problems that have been pointed by himself and others. He says that it has been changed to incorporate inflation, but that the model is still flawed. He offers a "fix" for the cyclic model and then basically dismisses it as a needless complication to the chaotic inflation model.

You can get a feel for what he thinks about the cyclic model from this quote in the paper.
I would be very interested in any comments that any of you might have.

Inflationary Theory versus Ekpyrotic/Cyclic Scenario



<font size=-1>[ This Message was edited by: rsa on 2002-06-05 10:08 ]</font>

So far, I have noticed no mention of the cyclic theory in NATURE, so perhaps it is too early to tell how the scientific world will think about it. I have this problem with the rebound. If all of the matter has turned into elementary particles and/or energy, how is it possible to have a repeat performance? I am not a cosmologist, but I would be interested in what happens when brane meets brane for the repeat performance.

I will be interested in watching this theory and its authors, Steinhardt and Turok, fight it out in the scientific community.

It is such fun to find new ideas being presented in the legitimate journals. Of course, Andre Linde's ideas are very much respected in the scientific community.

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"There is in the universe neither center nor circumference." Giordano Bruno Born 1548. Torched 1600.