Talk:Accelerating expansion of the universe

Hm. This is a bit out of my field, but isn't inflation theory another possible model for the accelerating universe phenomenon? -- April

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Yes, but that's included in non-zero cosmological constant (which presumably caused inflation).

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Wrong, sorry. The present non-zero cosmological constant/quintessence can be thought of as a form of inflation, but it probably has no relation to the inflationary scenarios (they are not theories, because they are too vague!). The inflationary scenarios generally talk about inflation when the Universe was about 10^(-33) seconds old, long before the microwave background epoch.

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See the special edition of
Scientific American, Volume 12, Number 2
Title: The Once and Future Cosmos
It is readable, detailed, and current.
Randal Leavitt 00:40 Oct 13, 2002 (UTC)

Acceleration

Does anybody know what is the value of the acceleration of Hubble's constant in terms of dH/dt. There is an obscure relativistic effect that partly simulates the accelerated expansion of space. For our universe this simulated part would be of order of 2x10^-36/s/s. I wonder how close this theoretical value is to the observed one. If close enough it might mean that the whole acceleration is just an illusion produced by subtleties of Einsteinian gravitation. Jim 20:41, 13 Jul 2004 (UTC)

I'm not sure. It should be relatively trivial to get from Friedmann's equation (or rather a derivative of it) given Omega_m of .3 and Omega_lambda of .7 I think. You could always give it a go yourself and see how it comes out. Otherwise I'd suggest tracking down the original Type 1a supernova paper that suggested an accelerating universe. EddEdmondson 20:02, 14 Jul 2004 (UTC)

I wrote to Ned Wright about it and he gave me the value of $(dH/dt)/H_{0}^{2}$ in terms of $\Omega _{m}$, $\Omega _{\Lambda }$ which comes out as -0.45. It might mean that the whole acceleration is an illusion since the theoretical Einsteinian prediction of the effect is -1/2 (11% off) and the accuracy of $H_{0}^{2}$ alone is 8%. Jim 16:56, 13 December 2006 (UTC)

Expanded

I think that this article could stand to be... Expanded. Mr. Billion 06:10, 5 Mar 2005 (UTC)

I recently expanded the dark energy article. They are nearly the same topic. --Joke137 15:55, 5 Mar 2005 (UTC)

Redirect to dark energy?

I would like to directed this page to the dark energy article. The only information on this page which isn't in the general review in dark energy is the stuff about zero point and eternal intelligence, which might as well go into the pages that are being referred to. I think pages like ultimate fate of the universe, cosmological constant or quintessence (physics) could be useful as independent pages, but I can't really see anything going in here that wouldn't belong either in dark energy or a more specialized page on cosmology with Type Ia supernovae. --Joke137 18:11, 7 Mar 2005 (UTC)

Negative pressure

As a layman i have to ask what is negative pressure? Does it have anything to do with gravitational repulsive material? -- Orionix 00:56, 10 Mar 2005 (UTC)

It has everyting to do with it. See cosmic inflation.--Michael C. Price ^talk 08:14, 8 December 2006 (UTC)

Inflation, then decceleration, THEN acceleration

A recently-verified fact that is often ignored is that the universe was deccelerating by gravitational attraction up until about 5 billion years ago. This was preceded, in theory, by a period of rapid expansion called 'inflation', and followed by the current acceleration caused by the 'funny energy' in space. Thus the expansion of the universe goes through three radically different epochs: 1. A fraction of a second of rapid acceleration immediately after the Big Bang. This inflation is the small epoch of expansion that lasted from 10^-43 seconds to 10^-35 seconds after the Big Bang, and caused space to expand faster than the speed of light, 2. A period of about 10 billion years of decceleration by gravitational attraction before matter was dilute enough to be dominated by the antigravitational effect of the 'dark energy', 3. The current epoch of about 5 billion years in which 'dark energy' rules over gravitational attraction. In this third period, the 'dark energy' creates an outward push called 'negative pressure' much like the air in blowing up a balloon. See my book http://empyreanquest.com/science/cr/cosmrep.htm Cosmic Acceleration: Hounding The White Whale of Cosmology free online. Philip Petersen, PhD

Arrogantly, (since I have no training in this field) I say that even if there was not a big bang, space would still be here. Space is', just as God is', and in my opinion space was not created by a big bang but merely the "field" in which the bang banged. The cosmologiocal constant and space and God and ether was and always will be there or.......HERE.

Certainly there would be no galaxies or visible creation without a bang, but space would still exist. The exasperating question arises of : "Well, if there was nothing to experience or exist in space and no one to experience it, how do we know space was there prior to the bang? It would be impossible to measure space without any contents but space would still exist, MERELY AS SUBJECT, SINCE NO OTHER SUBJECT WOULD BE THERE TO SEE IT AS AN OBJECT. This question is a paralell to the other very silly question of "if a tree falls in the woods and no-one hears it?... did it make a sound?" ...and... the even sillier postulated answer given by the so-called "wise and educated" of "No, it did not". How absurdly preposterous by anyone posessing of common sense! Although it made no resonation in the ear of the dummy who provided the ill-accepted answer ... I am sure it made a sound in the ear of the innocent and simple-minded, little woodpecker who made his nest there.

In fact, space, being infinite, is not measurable... by the very definition, only opne object to another. But space is not an object. It is merely subject. Singularity, (since we are in need of a word to represent the time before a 3-D creation and the condition within a black hole) was the existence at that time before the big bang, YES...but space was already here and space has to be infinite in all directions. Obviously, the reason is this: If there was a boundary to space...then what is beyond the boundary? And...any boundary that may be there would be permeated with the cosmological constant AND/OR ether, being one in the same.

I correlate all this cosmology with my own finite understanding of an infinite being...i.e. God. Not the jealous God of the Bible but that Omniscient, Omnipresent and Omnipotent God. Ether, or the cosmological constant is "His" very body and/or mind and what we percieve is "His" thoughts/creations from "His" infinite mind which creates merely from thinking it (whatever it is) into being... and it is done immediately. His omnipresence is apparent in the fact of the cosmological constant which is everywhere, not only between objects in space but within and outside the creation as well.

When I was young, that term was "ether"... not ether like what is sniffed to wake up the unconcious but ether as in that ungraspable thing that is in everything but not contained by it. Ether is the mind or body of God in which all things exist.

I never hear the term "ether" used any more. I do not know why not. It is much easier to say than cosmological constant and therefor comprehension easier.

Instinctively yours.

66.56.17.250 21:32, 3 March 2007 (UTC)

Relativity, Blue-Shift & Redshift

All mass is simply a ratio of Potential Kinetic Energy..

Electromagnetic waves are possible via the exchanges from these two states.

Blue-Shifted Electromagnetic waves are compressed waves. Red-Shifted Electromagnetic waves are the opposite..

Now if each and every Galaxy is a compression point, then each and every galaxy would seem to us to consist with an event horizon and or extremely Blue-Shifted Mass, Oh AND there is our proper source for Gravity..

Now should we be able to observe a mass approach this event horizon we would perceive the mass to be compressed and slow down the closer it nears the event horizon, all mass is Blue-Shifted..

What is interesting is if we were on this mass our observations towards the other direction away from the Black-Hole, the distances would be increasing, and whats more along with this distancing, all mass would seem to increase and whats more to accelerate!

Now before you move on to overlook this.. Consider the speed of light "electromagnetic waves" in a NEAR Vacuum to the speed of light in a solid and or MASS that consists of a higher ratio of Potential energy over Kinetic energy..

The Whole Universe IS NOT EXPANDING, but rather only a portion of it so there is no violations in any physical laws. — Preceding unsigned comment added by 59.101.181.97 (talk • contribs) 17:07, 20 December 2007