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Author Topic: Very basic cosmology question  (Read 35970 times)

Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #50 on: 17/05/2005 00:01:50 »
When you say "non-moving", non-moving relative to what? Surely everything in the universe is in motion.

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Offline chimera

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Re: Very basic cosmology question
« Reply #51 on: 17/05/2005 20:51:29 »
'Non-moving' by comparison - relativistic speeds, where GR excels. Quantum Mechanics is better at describing things at the particle end.

The other abbrevs are RP (Roger Penrose) and SH (Stephen Hawking) btw, one of whom I greatly admire... :)

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Offline daveshorts

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Re: Very basic cosmology question
« Reply #52 on: 17/05/2005 21:29:18 »
Something which just occured to me as an interesting idea was what would happen if near the beginning of the universe there were more dimensions and they all curled up sort of in the inflation phase...

<begin unqualified and probably incoherent babble>

I wonder if a collapsing dimension could somehow dump lots of energy into the other dimensions as it were... sort of what happens if you stand on a balloon (that doesn't burst)... you loose a dimension and grow lots in the other two.

If you think of how gravity works if all the dimensions were closed but some smaller than the others - say we have a fourth dimension called w which is the small one

everything would be closer together in the w dimension than in the other ones so the mass would all tend fall towards itself along the w dimension more than teh other 3. when two objects got close to each other they would orbit round each other and fly apart in a random direction - often in the x,y, or z directions - so overall you would be converting potential energy in the w direction and converting it into kinetic energy in the x, y and z directions...  

so the w direction would collapse into a small loop and everything would suddenly accelerate in the x,y and z directions... would this appear to us afterwards as inflation?

apart from anything else if it happened really late it would screw up the assumptions about the brightness of a light source as intensity wouldn't go as 1/r^2 any more. I think it would screw up a lot more than this including orbits as there are no stable orbits in more than 3 dimensions, so it would have to have happened before the universe went transparent...

Maybe I should have gone to some of the optional cosmology courses and then I could talk more convincingly or see more of the great big holes in this... ho hummm
« Last Edit: 17/05/2005 21:29:48 by daveshorts »
 

Offline chimera

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Re: Very basic cosmology question
« Reply #53 on: 17/05/2005 22:16:04 »
Interesting idea, could explain where the extra dimensions in string theory 'go to'.

On an equal tangent: you know what set me off thinking that if you try to unravel space backwards, stuff does not fit, and you have to start thinking how it sort of breaks down from a 'rational' number of dimensions? Our number system, which you could see as a 'representation' of how we count reality, has similar problems. I could show you very simple rules in numbers, that break down as you approach zero, or long before that, near three actually you can say things suddenly work out differently than 'before'. Also think primes. When I was young both 1 and 2 were considered primes, with 1 as a kind of obligatory odd duck, and 2 as the only even prime, making it unique. Nowadays primes start at 3. Easier on the rules... that single simple shift speaks volumes, though. There is something distinctly strange going on at that cusp.

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Offline chimera

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Re: Very basic cosmology question
« Reply #54 on: 17/05/2005 22:46:50 »
Here's one example where you see the simplest of rules go very linear - above three, that is.

http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cgi?Anum=A076505

That's only one example, mind you. And they cannot always be explained because the 'numbers are too small' or 'don't fit' or whatever. It's like a spiral suddenly twisting differently, more tightly.

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Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #55 on: 18/05/2005 12:39:29 »
OK, I follow that "Hello" thing but I'm not sure I understand the significance of it.

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Offline chimera

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Re: Very basic cosmology question
« Reply #56 on: 18/05/2005 18:18:59 »
Short answer: if you do statistics, your population cannot be too small. Likewise, for certain phenomena to occur at all, you need a basic framework of particles/forces in place. If you keep taking away stuff, at specific points you see the rules change. Shapes and configurations can be equally important, there appears to a minimum in necessary complexity.

Now what daveshorts is trying to do is similar to what I'm researching: see what happens with the rules in different situations.

To give you a better, but harder to grasp, example of how rules change in different 'areas' in number theory, here's Robin's theorem, which states that below 5041 our neat number system does something totally peculiar:

http://mathworld.wolfram.com/RobinsTheorem.html

now interestingly, 5040 is a number already acknowledged by Plato to be very special, and its neighbour 5041 is interesting not only because it's 71*71, but also because it ties in with how many cannonballs you can stack in a minumum space.

This is completely different what goes on above 5041, btw. This is of interest to a lot of people because of its possible implications not only in all kinds of prime number theories etc, but also in cryptography. They want to know if this 'hickup' in number theory has any cousins 'out there' in higher number regions, where their calcs could screw up bigtime, and predictions/theorems like the Goldbach suddenly would no longer hold.

Where it all comes togethere is that the series I gave you and other, more important ones agree and to a certain extent not only confirm, but help to better explain  the behaviour of quarks in QCD and how they combine to create mesons.

Those rules are essentially calculations - bookkeeping if you will. Lie groups, su(3) etc and how crystals are built up are all related, simply because similar rules apply.

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Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #57 on: 18/05/2005 21:27:34 »
I'm aware of the low population rule. Have you come across "Life" on a computer? I think that illustrates the point quite well.
As for Robins & Goldbach - erm... I want my mummy!

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Offline gsmollin

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Re: Very basic cosmology question
« Reply #58 on: 19/05/2005 02:16:17 »
Here it is! It's been coded in Java! John Conway's Game of Life.

http://www.bitstorm.org/gameoflife/

I still remember that Scientific American article. Was that really 1970? I programmed it in FORTRAN and BASIC, and ran it on timesharing mainframes and S100 bus microcomputers. Damn, that's making me feel old.
 

Offline chimera

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Re: Very basic cosmology question
« Reply #59 on: 19/05/2005 19:39:29 »
Game of Life is different in the sense the rules stay the same no matter what size the population, although you could program that different.

My point is just that the opposites of primes, the Highly Composite Numbers (those with the most divisors) are spitting images in their behaviour and composition compared to how particles are built up under different circumstances (combinatorics again), and there are striking similarities how the 'rules' collapse, or break down depending on where you are...

Especially if you find out that these numbers come with '3' at heart (Niven Harshad numbers), like the number of quarks in particles, and that they propagate in a 24-fold cycle (always), which happens to be the number of possible mesons you can make - the building blocks of all matter.

To put it in a nutshell: with high numbers (read: a lot of particles), things behave differently than if you go towards 1 (a singularity of sorts, too). And the way these series break down is maybe capable of teaching us a trick or two without having to smash atoms, because at heart the same thing happens.



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« Last Edit: 19/05/2005 19:44:57 by chimera »
 

Offline pope

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Re: Very basic cosmology question
« Reply #60 on: 19/05/2005 23:16:28 »
the energy comes from the earths core
 

Offline daveshorts

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Re: Very basic cosmology question
« Reply #61 on: 20/05/2005 00:32:40 »
Ok.... urr was this supposed to be posted here?
 

Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #62 on: 20/05/2005 12:10:05 »
quote:
Originally posted by chimera

Especially if you find out that these numbers come with '3' at heart (Niven Harshad numbers), like the number of quarks in particles, and that they propagate in a 24-fold cycle (always), which happens to be the number of possible mesons you can make - the building blocks of all matter.

To put it in a nutshell: with high numbers (read: a lot of particles), things behave differently than if you go towards 1 (a singularity of sorts, too). And the way these series break down is maybe capable of teaching us a trick or two without having to smash atoms, because at heart the same thing happens.



So are you saying that numbers & sequences of numbers determine how particles behave? Or that the behaviour of particles somehow determines maths? That sounds very Qaballistic (ancient Judaic teaching is that numbers are the basis of creation & everything has a numeric value. The way these values interact to produce other values is the very key to creation, life & an understanding of God).

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Offline chimera

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Re: Very basic cosmology question
« Reply #63 on: 20/05/2005 13:15:50 »
No, not determine, as much have parallel behaviour with how particles act. Not as strange as it sounds, because we use all kinds of metaphors be they prisms, pieces of cardboard with holes to see which hole the light goes trough to make stripes, and ultimately the computer as super-abacus that allows you to take simple calculations a lot further, and put them in nice graphs that look more like plants than anything to do with numbers, or anything else.

Quabbalists would probably freak out from using Clifford algebra, where a times b does not equal b times a (i.e. is non-commutative), fractals, Lie groups, shapes that exist only in 4 dimensions, and the sheer domain of numbers that are involved. 858899288969751 is a unique number for instance, but to find out it's the only Carmichael under 10^16 that's 15 modulo 24 really takes a computer, I think, although you can even check that result with your ordinary 32-bit desktop calculator. You won't find any others, though. Pretty strange, that.

So basically, you look for surprises in places where there should be no such surprises and compare the differences with other regions. My 'galaxies' of numbers are no more or less real than the 'real' galaxies which you only can see on film, btw - they're too dim for the naked eye. Most people don't realise they only know those nice swirlies from pictures, and can never find them looking up, even on the clearest of nights. You have to lock a camera into looking at the same spot for a very long time to pick them up.

Never heard anybody complain about that, either :)

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Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #64 on: 20/05/2005 19:09:33 »
Rob - I'm still don't see the significance of some of the maths you're talking about. When you say that "858899288969751 is a unique number for instance, but to find out it's the only Carmichael under 10^16 that's 15 modulo 24", not being a mathematician, I don't see what's so unusual about that. To my mind, saying that 4 is the only square of a whole number < 3 is just the same.
I think I'd better butt out of this post because obviously it's all about esoteric maths & I haven't a hope in hell of understanding it. But thanks for trying
 

Offline chimera

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Re: Very basic cosmology question
« Reply #65 on: 20/05/2005 19:39:54 »
It's not so important, just a curious side-effect of something that IS of relevance, but indeed, let's drop it.

Just remember that numbers pop up in the weirdest of places:

here's how to calculate pi by throwing a needle repeatedly over a few lines drawn on a table...:

http://www.mste.uiuc.edu/reese/buffon/buffon.html



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Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #66 on: 21/05/2005 23:25:48 »
Now that pi thing has really melted my brain!

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Offline chimera

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Re: Very basic cosmology question
« Reply #67 on: 22/05/2005 10:59:12 »
Careful with the cotton-tips, then. :)

Back to the topic: howcome we can only see 12 billion years of light.

Strangely, as I mentioned in another topic, there are structures withIN that area that by all accounts have to be older than that, by quite a margin: 80 billion years for super-clusters to form as they are now.

Maybe gsmollin would like to take a shot at that one? Can't say I've heard any really good explanations for that yet, and would make the whole original question slightly silly, wouldn't you agree?



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« Last Edit: 22/05/2005 10:59:42 by chimera »
 

Offline daveshorts

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Re: Very basic cosmology question
« Reply #68 on: 22/05/2005 11:38:13 »
I think the reason that there is a limit to how far we can see is that before 12 billion years ago the universe was a plasma so was opaque to light - the light released by all the hydrogen atoms catching electrons at the end of this period forms the microwave background radiation. (greatly red shifted for UV to microwave)

I would have thought that the estimates of the age of super clusters were pretty dodgy as cosmologists are working on very little solid data and don't entirely understand the physics yet.
 

Offline chimera

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Re: Very basic cosmology question
« Reply #69 on: 22/05/2005 12:40:18 »
quote:
Originally posted by daveshorts

I would have thought that the estimates of the age of super clusters were pretty dodgy as cosmologists are working on very little solid data and don't entirely understand the physics yet.



Well, I wouldn't call the results of 5000 galaxies 'very little solid data' and it's true the physics isn't yet known, 80 billion years is a conservative possibility.

The entire pattern stretches across a quarter of a diameter of the observable universe, a distance of over seven billion light-years. At the known expansion speeds both current and past that would add up to a 150 billion range figure.

keywords: supercluster, Tully, Fischer, Great Wall



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Offline daveshorts

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Re: Very basic cosmology question
« Reply #70 on: 22/05/2005 16:25:50 »
Maybe it is because I am more of a solid state type of person I find the number of layers of calculations that are enevitable in cosmology... worrying. Basically a very small change in the physics, or even in their data would radically change their conclusions.

I don't know anything about this particular example, but data from 5000 galaxies could be rubbish, depending on what the error bars are, how sensitive their model is to the data, how good their model is etc etc.

essentially you may be right or not - I don't trust cosmology enough to get worked up about its results...
 

Offline gsmollin

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Re: Very basic cosmology question
« Reply #71 on: 22/05/2005 23:35:47 »
These numbers have always been at issue, so this is no news. The first expansion numbers for the universe put its age at less than the earth's. Cosmology is not an exact science. The steady state proponents have been quoting those big numbers for about 50 years to discredit the big bang theory. This problem falls under "details". There are fatter fish to fry. As the more fundamental problems get good answers, the rate of organization of superclusters will fall out. I think the answer will be that the organization of the supercluster is primordial. We are seeing an imprint of a structure that formed in the first instant.
 

Offline chimera

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Re: Very basic cosmology question
« Reply #72 on: 23/05/2005 20:07:46 »
If it's primordial, then why does the process seem to be speeding up, one could ask oneself.

Found this quite recent link that explains why neither dark-matter or the newer dark-energy theories are quite capable of getting to grasps with the phenomenon:


http://universe-review.ca/F03-supercluster.htm#fluctuations

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[typo]
« Last Edit: 23/05/2005 21:31:43 by chimera »
 

Offline DoctorBeaver

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Re: Very basic cosmology question
« Reply #73 on: 23/05/2005 21:00:39 »
There's some quite interesting stuff on that link: but i'll need to read it through a few times to really get a grasp of it.
 

Offline chimera

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Re: Very basic cosmology question
« Reply #74 on: 23/05/2005 21:43:12 »
Yeah, as I said, just came across that one, pretty new. Think they use some Java menu or so, and I've got that turned off just now, but also check out the main page, it's pretty extensive:

http://universe-review.ca/

Oh, and I see they've now mapped over 3 million galaxies, not the measly 5000 local ones.

Correction - that's several weeks down the reading drain. That's a lot of goodies.  :)

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« Last Edit: 23/05/2005 21:46:51 by chimera »
 

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Re: Very basic cosmology question
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