Evidence for Universe Expansion Found

Yahoo (AP) ^ | 3/16/2006 | MATT CRENSON

[The_Victor]

Physicists announced Thursday that they now have the smoking gun that shows the universe went through extremely rapid expansion in the moments after the big bang, growing from the size of a marble to a volume larger than all of observable space in less than a trillion-trillionth of a second.

The discovery — which involves an analysis of variations in the brightness of microwave radiation — is the first direct evidence to support the two-decade-old theory that the universe went through what is called inflation.

It also helps explain how matter eventually clumped together into planets, stars and galaxies in a universe that began as a remarkably smooth, superhot soup.

"It's giving us our first clues about how inflation took place," said Michael Turner, assistant director for mathematics and physical sciences at the National Science Foundation. "This is absolutely amazing."

Brian Greene, a Columbia University physicist, said: "The observations are spectacular and the conclusions are stunning."

Researchers found the evidence for inflation by looking at a faint glow that permeates the universe. That glow, known as the cosmic microwave background, was produced when the universe was about 300,000 years old — long after inflation had done its work.

But just as a fossil tells a paleontologist about long-extinct life, the pattern of light in the cosmic microwave background offers clues about what came before it. Of specific interest to physicists are subtle brightness variations that give images of the microwave background a lumpy appearance.

Physicists presented new measurements of those variations during a news conference at Princeton University. The measurements were made by a spaceborne instrument called the Wilkinson Microwave Anistropy Probe, or WMAP, launched by NASA in 2001.

Earlier studies of WMAP data have determined that the universe is 13.7 billion years old, give or take a few hundred thousand years. WMAP also measured variations in the cosmic microwave background so huge that they stretch across the entire sky. Those earlier observations are strong indicators of inflation, but no smoking gun, said Turner, who was not involved in the research.

The new analysis looked at variations in the microwave background over smaller patches of sky — only billions of light-years across, instead of hundreds of billions.

Without inflation, the brightness variations over small patches of the sky would be the same as those observed over larger areas of the heavens. But the researchers found considerable differences in the brightness variations.

"The data favors inflation," said Charles Bennett, a Johns Hopkins University physicist who announced the discovery. He was joined by two Princeton colleagues, Lyman Page and David Spergel, who also contributed to the research.

Bennett added: "It amazes me that we can say anything at all about what transpired in the first trillionth of a second of the universe."

The physicists said small lumps in the microwave background began during inflation. Those lumps eventually coalesced into stars, galaxies and planets.

The measurements are scheduled to be published in a future issue of the Astrophysical Journal.

[js1138]

Perhaps Heaviside has become more widely known due to the Andrew Lloyd Webber song Journey to the Heaviside Layer in the musical Cats , based on the poems of T S Eliot:-

Up up up past the Russell hotel
Up up up to the Heaviside layer

Link

that journey has a one way ticket.

[VadeRetro]

... on a whimper.

BANG!!!

[Les_Miserables]

So.. is the speed of light a constant or not? (and was it always so?)

[RadioAstronomer]

So.. is the speed of light a constant or not? (and was it always so?)

Yes! and Yes!

[VadeRetro]

What he said.

[Southack]

"Not only did Heaviside predict gravity waves, he also shows that a gravity wave moving at a finite speed (i.e. moving at the speed of light) would have no measurable affect on our orbit..."

Indeed. And Here he also points out that "so far as I can see from the above considerations, are small perturbations due to the variation of the force of gravity in different directions, and to the auxiliary force. Of course, there will be numerous minor perturbations If variations of the force of the size considered above are too small to lead to observable perturbations of motion, then the striking conclusion is that the speed of gravity may even be the same as that of light. If they are observable, then, if existent, they should turn up, but if non-existent then the speed of gravity should be greater."

...not bad for 1893.

[Les_Miserables]

Is it true from our point of observation or is it an assumption or is there definitive proof residual in the universe?

[longshadow]

The latest, most accurate data is depicted here:

The older, less accurate data is shown in red. The more accurate data are shown in blue, plus the data point in black.

Note that the error bars of blue and black data points all straddle the line denoting the change in the Fine Structure Constant, alpha, being equal to zero.

The Fine Structure constant, alpha, includes terms representing the speed of light and the charge of an electron. Ergo, if the speed of light has changed during the history of the Universe, it should manifest itself as a change in alpha, as observed at various redshift distances corresponding to earlier eras in the history of the Universe.

This data, published in December 2005, is compatible with there having been no change at all in alpha, and hence the speed of light, over cosmological time scales.

[Les_Miserables]

This has been a great thread and I will hate to see it pass.
For us uninitiated buffs it has been challenging, informative, confusing and enlightening. It makes me wonder a bit what my life would have been like had I followed my EE degree with graduate studies in physics instead of business. I expect though with my limited insight I made the right financial decision after all. Having said that, and appropriately admitted my lack of insight (but amazement nevertheless) into the realm of quantum physics, I am puzzled by a constant that is expressed in space dimension and time but must have preceeded both (and both of which are variables?) since it seems here at least that space and time were both "created" (or determined) immediately post the BANG.

Anyway it seems that there is some debate on the "constancy" of the Fine Structure Constant so I'll reserve judgement I guess. Clearly I'm not equiped to debate only inquire and it will not change the taste of my chocolate pie. In that I take no small comfort. FSC is also an enigma to me since it must have emerged after "c" as it seems to depend on the electron which was unavailable at T-0... would seem to make is a questionable yardstick for "c"..oh well there is much I'm not equipped to understand..Thanks to all for an enlightening thread.

BTW, I asked the question about "c" in the first place because I wondered what rules would be turned on their heads if for example "c" was infinite at T-0 and 0 at T-max. (approached the asymtotes). It would have helped me rationalize how all matter could expand from a marble to fill the universe uniformly in 10^-35 secs..(and where "t=c" near the origin). I also understand it would help bridge the gap between Einstein and Bohr but I'm not sure why. My wife tells me I should worry about the gas bill. I will do that right after the chocolate pie. Thanks guys.

Oh. longshadow, can you give me a ref for the chart on FSC? I'd like to read that piece of work. (hoping its a web link since my scientific subscriptions are as sparse as the local library on these topics) Damn this is fun!

[longshadow]

.... can you give me a ref for the chart on FSC?

Right click on the chart:

http://www.astro.ucla.edu/~wright/Dalpha-2005sm.gif

There's a small amount of verbiage, with a link to the original study, a short ways down the page HERE:

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

[Les_Miserables]

Hey, thanks. I'll check it out.