Redshift z

[coldcreation]

All de Sitter models have a constant curvature greater then 0. I don't see how this could model anything other then an exponentially growing universe.

-Will

 

To assume that curvature is synonimous with expansion is an aberration. Why should curvature equal instabillity? A universe with 0 curvature is impossible by any standards. De Sitter had shown that even an empty universe would show curvature. That did not mean that it had to expand. Einstein explains the problem of curvature well enough for everyone to understand. Read GR. You might also want to check out Kosmos by de Sitter.

[coldcreation]

ColdC, what are your opinions of Joao Magueijo's VSL theories? In his theories, especially the later work with Lee Smolin, a flat universe with the possiblity for varying speeds of expansion is the natural outcome of inflation (if I have read it correctly).

 

Got a link? Off handedly I would dismiss the above argument as a desperate attempt to save inflation in the wake of detrimental evidence from distant SN that show the universe not to be flat. The varying speeds were supposed to be deceleration due to gravity (due to the nonzero mass energy density, called omega) not acceleration (attributed to a dark force). Look at the original inflation calculations.

[Tormod]

Hm...links. The book is available, it was written in 2003.

 

Amazon.co.uk: Faster Than the Speed of Light: The Story of a Scientific Speculation: Joao Magueijo: Books http://www.amazon.co.uk/exec/obidos/ASIN/0099428083/

 

A paper by Magueijo and Smolin:

General Relativity and Quantum Cosmology, abstract - Gravity's Rainbow

http://xxx.lanl.gov/abs/gr-qc/0305055

 

It contains references to further works.

[Tormod]

The day new physics will no longer be needed will be when an ultimate theory is found that explains all observations and experiments without the need of fudge factors. What's so sad about that.

 

What basis do you have to assume there can even be a theory of everything?

 

Recall Tormod, 'new physics' is a term use for artificially introduced things such as dark matter, dark energy, false vacuums, extra dimensions etc. Are you saying that real physics would not function properly without such artifice, and that we should continue to pursue wacked-out ideas in the hopes of perpetuating some creative drive that might one day, hundreds of years from now, lead to a theory of everything that really explains nothing?

 

"Artificially introduced"... :wave: You keep ridiculing that which you don't like. Modern physics must be a nightmare for you, CC.

[C1ay]

...'new physics' is a term use for artificially introduced things such as dark matter

Are you suggesting there is no dark matter?

[Southtown]

What basis do you have to assume there can even be a theory of everything?

Because everything is an integral part of everything else. And nothing is seperable into a solitary existence.

[Tormod]

Because everything is an integral part of everything else. And nothing is seperable into a solitary existence.

 

And this is proven how? Can you prove that the universe does not constitute a "solitary existence"?

[Southtown]

And this is proven how? Can you prove that the universe does not constitute a "solitary existence"?

I thought hypotheses were supposed to be proven wrong.

[Erasmus00]

To assume that curvature is synonimous with expansion is an aberration. Why should curvature equal instabillity? A universe with 0 curvature is impossible by any standards. De Sitter had shown that even an empty universe would show curvature. That did not mean that it had to expand. Einstein explains the problem of curvature well enough for everyone to understand. Read GR. You might also want to check out Kosmos by de Sitter.

 

I'm not equating curvature with expansion. However, GR shows that spacetimes with constant positive curvature have space volumes that grow exponentially with increasing time.

-Will

[Tormod]

I thought hypotheses were supposed to be proven wrong.

 

Hypothesis: "There are many universes."

 

Prove it wrong.

[coldcreation]

Are you suggesting there is no dark matter?

 

I suggest there is no exotic non-baryonic dark matter of the kind though to make up a huge portion of the mass density of the universe. There is obviously dark matter composed of brown dwarfs, rocks, comets, dust hydrogen atoms, molecules, etc.

 

There is no dark energy either, of the kind thought to drive expansion to an ever increasing acceleratory frenzy.

 

Neither are needed, both are artificial and both constitute new physics, i.e., there is no physics that can explain either or.

 

ColdC

[Erasmus00]

There is no dark energy either, of the kind thought to drive expansion to an ever increasing acceleratory frenzy.

 

But don't you advocate a non-zero cosmological constant? It has been suggested that "dark energy" could just be a non-zero constant.

-Will

[coldcreation]

What basis do you have to assume there can even be a theory of everything?

 

"Artificially introduced"... :rant: You keep ridiculing that which you don't like. Modern physics must be a nightmare for you, CC.

 

Hi hi hi, your funny Tormod. You know I love cosmology, nature and physics. Otherwise I wouldn't write about it so much, and I certainly wouldn't condem modern cosmology. The reason I do crtique so drastically modern cosmology is precisely because it has vacated almost all natural explanation, most physical possibilities from its doctrine. Before the invention of the big bang cosmology was headed in a different direction. The deviation brought about by bbc added a man-made factor to nature that (is no nightmare) is not surprising given that what is trying to be understood is something outside nature by definition. What else can be done than to invent even more absudities.

 

Actually the problem reminds me of the history of art. With time t contemporary art has gone through abstraction, conceptualism, minimalism, pop, etc. Now it has become (for better or worse) a free-for-all, where shock plays an important role.

 

Your reference to Magueijo for example is a good one. His book 'Faster than the Speed of Light' has an ultra provocative title. It is meant to stir up interest, to rile the hardliners, to sell. He known damm well there are no superluminal particles, ultrarelativistic jets of plasma or anything else that can attain light speed, let alone surpass it.

 

Guth, Hawking, Linde, Steinhardt...they are all artists, with inventions that go way beyong the natural. That is ok though. It is creative. Man should never supress creativity, unless it goes beyond the bounds of creativity (if indeed there are any), into the realm of destruction. This happens all too often. In my opinion bbc is destruction. Nothing complex could have emerged from a collosal explosion some 14 .7 Gyrs ago but crude convection currents and charred remains of whatever is was that exploded. That, no one will ever know, because by definition, like god, it remains forever hidden behind a distasteful, synthetic event horizon. That is what I rebel against.

 

I am sure it is possible to construct an ultimate theory without all the artifice. I know it is possible. Cold Creation is one of those theories that vacates all the useless contraptions so common in physics today, or should I say new physics.

 

good day,

 

Coldcreation

[Tormod]

Your reference to Magueijo for example is a good one. His book 'Faster than the Speed of Light' has an ultra provocative title. It is meant to stir up interest, to rile the hardliners, to sell. He known damm well there are no superluminal particles, ultrarelativistic jets of plasma or anything else that can attain light speed, let alone surpass it.

 

You should read it if you haven't. It is incredible provocative, not only in it's title (which is actually wrong - what he writes about is a varying c, especially during the planck epoch where he suggests that a "high-speed" light solves many of the cosmological problems).

 

But his attacks on other scientists and the British educational system in general makes it a great read. :rant: .

[coldcreation]

But don't you advocate a non-zero cosmological constant? It has been suggested that "dark energy" could just be a non-zero constant.

-Will

 

Good question E...00. In fact I've never directly advocated a value for lambda. I certainly have never suggested it was nonzero. For the record: Lambda equals zero. It is not a parameter, i.e., it cannot equal anything but zero.

 

Actually this is more apt for the Cosmological Constant: A New Law thread. Maybe I'll open it up again. I had been waiting for someone to ask that question before answering it.

 

It equal zero, yes, but that is not all. Lambda still needs to be identified. elucidated, described, justified, exposed. As a physical mechanism, property or phenomenon it should definitely be layed out in plain view. Never before has that been done convincingly. Eddington had come close. So too had others, Einstein included. But each time the attempt was made some stumbling block presented itself. Then with the advent of the SN Type Ia (1998) redshift observations it took on another hue, one that no longer resembled anything we could put our fingers on, one that no longer held physics responsible for its actions.

 

The beauty is that conventional physics is sufficient to lay bare lambda once and for all...

 

ColdC

[BlameTheEx]

There is no 'outside' the universe. If a meteorite came knocking on your front door that was older than the universe it would meen that your creation theory was lacking.

Not necessarily. As I have tried to point out, it could be evidence that our universe has, or at least had, communication with another universe. Just because our 3 dimensions of space apparently belongs to our universe alone doesn't eliminate the possibility (This is not saying that other universes don't have 3 dimensions of space, just that they are independent from our universe's dimensions of space). It might be true now, but not at the point of creation. Then again, perhaps our universe shares other dimensions with external universes. Transfer of matter or energy would still be possible, just not to a defined location.

 

Proof (almost) of the big bang is based on redshift as a Doppler effect, CMB as a relic soup, and abundance of light isotopes. None of these constitute a morsel of proof (or evidence) in favor of bb cosmology.

I can agree on the lack of proof, but we will just have to disagree regarding evidence. There is some evidence, it just isn't good enough. BB cosmology is at least in the running.

 

It would be pleasing to see just one prediction of bb cosmology turn out to be correct, just one. I still await its arrival..

And i would also like to see the predictions of any of the alternative theories turn out to be correct. We all live in hope.

 

As far as the Abbe Lemaitre...tell any layperson that knows little or nothing about cosmology that a priest invented the big bang and see what knid of response you get...

It has never been my habit to judge the validity of theories that way. Is it yours?

 

The universe itself is not proof that a creation event occurred. That sounds like creationism to me. It sounds like you read to much Hawking.

True, but it is evidence. In principle, and presuming there was a creation, our understanding of our universe should eliminate possibilities for creation because they don't lead to what we know of the universe. As example our knowledge of geology puts a lower limit on the age of the Earth, and hence the Universe. In principle a sufficiently thorough understanding of our universe might reduce the number of plausible creation theories to one.

[Tormod]

It would be pleasing to see just one prediction of bb cosmology turn out to be correct, just one. I still await its arrival.

 

Believe nothing you read and only half of what you see...

 

See, that is why it's pretty fruitless to discuss anything with you, cc. You disregard what is considered proof because you do not accept that it may be. You act as if BB theory is some kind of deity which we must not have any faith in. But it is merely a scientific theory, and does not need to be treated like anything else.

 

So stop pretending that BB theory is pure hogwash. It may *turn out to be*, but until evidence is offered that better explain what we see, BB is the flavor of the decade.

 

The currently accepted and confirmed predictions of BB cosmology are:

 

1) Background radiation (which you blatantly disregard but have not yet shown any proof for, AFAIK)

 

2) Expanding universe (predicted in the 20ies by Friedman, confirmed by Hubble)

 

3) Abundance of light matter (The production of elements during the very early periods)

 

All three have been confirmed and thus support BB theory. Yet they can all be falsified at some point. And all introduce further issues.