Whilst researching anti-gravity I came across a story I had read some time ago and it started me thinking;

Expanding Universe

An idea came to mind that may have little to back it up, but I just wondered what others thought of it.

We have heard about the mysterious "anti-gravity" like force that fuels the expansion of the universe, but I realised that there may be another explanation which does away with the need for a new force.

This is the idea that came to mind;

Well thats where I am going with the thoughts anyway. You may prefer to discuss the article, or steer the subject in a slightly different direction either way the expanding universe is an interesting topic.

Jeff

p.s. I was in two minds as to which section to put this post in. As I have posted it here we should restrict replies to more mainstream science/astronomy.

<font size=-1>[ This Message was edited by: Phobos on 2001-11-01 06:45 ]</font>

Gravity waves, should they exist, will indeed be doppler shifted from an object which is in motion in space-time.

Since gravity waves are more akin to sound waves than they are to EM radiation, they will interfere more easily and produce more diffraction, diffusion, etc.

Antigravity, however, is something of speculation here. Maybe it works like sound and just gets shifted more and more but still has the same effect regardless of frequency. Maybe the medium in which the waves propogate, the fabric of space-time, attenuates them more at certain frequencies.

Perhaps this could tie in with inflation somewhere along the line.

__________________
"We want a few mad people now. See where the sane ones have landed us!" - George Bernard Shaw

This is in response to an earlier post. For some reason, I was unable to reproduce the question. I have not learned the magic required. Anyway, here is my answer to a portion of an earlier now mysterious post in this thread about the accelerated expansion of the universe:

This anti-gravity may be the result of *virtual particles*, incessantly coming into and out of existence in space, thereby producing an expansion of the Universe. The action of these *virtual particles* has been observed in Particle Physics experiments at CERN and at FERMILAB, and at the Linear Accelerator in California, etc. This energy has been variously designated: *Lambda* (after Einstein's *Greatest Blunder*), *Quintessence*, and *Dark Energy*. Sooner or later, one of these may become the name of this mysterious energy which is accelerating the expansion of the space between large galactic clusters. It is the space which is accelerating in its expansion, and is not matter which is expanding. That is, the so-called *empty space* is not empty, after all.

There is a wonderful videotape from NOVA called *The Runaway Universe* which details the history of this discovery with the discoverers shown at work at various astronomical installations (telescopes).

There was an article in the 18 December 1998 issue of SCIENCE, by James Glanz, with SCIENCE selecting this as the *Discovery of the Year* for 1998. The original article appeared in NATURE (LETTERS) in the 1 January 1998 issue, as *Discovery of a supernova explosion at half the age of the Universe*, by S. PERLMUTTER, et al., of the Supernova Cosmology Project.

There have been many astronomers and astrophysicists working on this, beginning with two opposing groups: Supernova Cosmology Project and High-Z Supernova Search Team (High-Z SN Search Team). Michael Turner, et al., at the University of Chicago foresaw this occurrence in his theories. Saul Perlmutter, Brian Schmidt, and Alexei Filippenko were foremost as leaders in this research.

I think this is one of the most important findings in Cosmology of all time. But, I am prejudiced. It is a favorite of mine. I love to see scientific theories change radically when driven by new measurements and experiments.

ljbrs [img]/phpBB/images/smiles/icon_biggrin.gif[/img] [img]/phpBB/images/smiles/icon_biggrin.gif[/img] [img]/phpBB/images/smiles/icon_biggrin.gif[/img] Whee!

<font size=-1>[ This Message was edited by: ljbrs on 2001-11-25 20:23 ]</font>

<font size=-1>[ This Message was edited by: ljbrs on 2001-11-27 20:39 ]</font>