Oldest light shows universe grew fast, researchers say [inflationary cosmology gets a big boost]

Houston Chronicle (www.chron.com) ^ | March 17, 2006 | Dennis O'Brien

[snarks_when_bored]

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March 17, 2006, 12:51AM

Oldest light shows universe grew fast, researchers say

First stars arose 400 million years after big bang, not 200 million years, as once thought

By DENNIS O'BRIEN

Baltimore Sun

Scientists examining the oldest light in the universe say they've found clear evidence that matter expanded at an almost inconceivable rate after the big bang, creating conditions that led to the formation of the first stars.

Light from the big bang's afterglow shows that the universe grew from the size of a marble to an astronomical size in just a trillionth of a second after its birth 13.7 billion years ago, researchers from Johns Hopkins and Princeton universities said.

Readings from a NASA probe also show that the earliest stars formed about 400 million years after the big bang — not 200 million years afterward, as the research team once thought.

"With this new data, theories about the early universe have just taken their first exam, and they passed with flying colors," said David Spergel, a Princeton astrophysicist and co-author of the findings published Thursday.

The results are based on readings from the Wilkinson Microwave Anisotropy Probe, a robotic instrument with two telescopes that sweeps the sky every six months in an orbit a million miles from Earth.

Light from the probe also has confirmed a theory that the universe is made up mostly of dark energy, a mysterious force that continues to cause the universe's expansion, said Johns Hopkins astrophysicist Charles Bennett, the probe's principal investigator.

"This light is just invaluable. It's really the only fossil we have from that time," Bennett said.

Inflationary theorists argue that at the time of the big bang, the universe was at first microscopic. But three events changed things: fluctuations in temperature, bursts that transformed energy into matter and a rapid expansion of the universe that ultimately enabled stars and galaxies to form.

By polarizing and filtering out light from the earliest stars, the researchers were able to uncover evidence of those inflationary moments — fluctuations in brightness of the light scattered around the big bang's afterglow. "It amazes me that we can say anything about the first trillionth of a second of the universe, but we can," Bennett said.

The researchers say the findings also confirm that only 4 percent of the universe is composed of the familiar atoms that make up what we see around us.

Another 22 percent is dark matter — a gravitational force made up of cold particles — and 74 percent is dark energy, a force that appears to be causing the universe to expand.

Experts say the findings will help scientists for years as they try to unravel mysteries about the early universe.

[RightWhale]

This piece of news is getting wide publication, many articles, many threads. No doubt many minds are tripping out on this information if it is new to them. However, it seems to be confirmation of Guth's inflation hypothesis rather than a new model.

[snarks_when_bored]

Oh, yes, I thought my title made that clear. It's inflationary cosmology that's helped by this new WMAP data, but not Guth's version only, as it appears. For now, there's still room for Steinhardt's 'ekpyrotic' ideas and Linde's 'eternal chaotic' ideas.

Guth is said to have been walking around with a big smile on his face for the last day or so. Clearly, he's in line for a Nobel prize in Physics. I wouldn't bet against him.

[RightWhale]

I favor a vastly enhanced version of Steinhardt's model. Guth kicked it all off no doubt, but there are far more powerful possibilities starting from that idea and shifting perspective.

[Doctor Stochastic]

What would you call the place where the marble-sized universe was located?
Everywhere.

What were its physical properties?
Very dense.

Do we say that an infinitely large space containing nothing, a total vacuum, was then and has since been filled by a universe of objects ranging from galaxies to sub-atomic particles?
No. Space is what is expanding.

[RightWhale]

Do we say that an infinitely large space containing nothing, a total vacuum, was then and has since been filled

That is not in any of the major mathematical models. What is in the models is that the universe, when it was microscopic and now when it is too big to imagine very well, was complete in itself: no outside to expand into.

[snarks_when_bored]

Veneziano's article (see AntiGuv's link in Post #73) contains a bit of discussion of Steinhardt's views. If you haven't read it, it's a fine article, albeit a couple of years old.

[RightWhale]

Steinhardt et al. got partway there. Odds are they are moving even farther along their isoclines even now but need to give the turntable a sharp rap.

[edsheppa]

Well could you ask the guy who built it why he made me late on for an important meeting last Wednesday?

Think of it as an original sin.

[edsheppa]

cosmologists don't seem to speak of time as also having expanded along with space (indeed, it's not clear what that might mean).

One way to think of it, by analogy with the spatial dimensions of spacetime is that time got "big." A universe w/o inflation would exist for a virtually infinitesimal amount of time before collapsing. Our universe, according to the latest and greatest evidence, may last forever.

[longshadow]

from one of the technical papers that goes with the new data; here's the "money shot":

9. Conclusions

The standard model of cosmology has survived another rigorous set of tests. The errors on the WMAP data at large ℓ are now three times smaller and there has been significant improvements in other cosmological measurements. Despite the overwhelming force of the data, the model continues to thrive. The data are so constraining that there is little room for significant modifications of the basic CDM model. The combination of WMAP measurements and other astronomical measurements place significant limits on the geometry of the universe, the nature of dark energy, and even neutrino properties. While allowing for a running spectral index slightly improves the fit to the WMAP data, the improvement in the fit is not significant enough to require a new parameter.

source:

Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology/>

Hopefully, somebody here can translate the geek-speak details in the paper into something a layman can comprehend.

[longshadow]

Sean Carroll has detailed comments:

That's an excellent summary! GLad you provided the link to it; it helps grasp the signifiance of these results.

[Physicist]

Hopefully, somebody here can translate the geek-speak details in the paper into something a layman can comprehend.

LOL, all 92 pages might take a while.

This paper stands as a refutation to anybody who says there's no value in unmanned space missions. This one mission has completely realigned our understanding of the universe, and done it with solid fact. Many ships of faith and fancy will rip their bellies open on this hard rock of truth.

But then, that's what the science-haters feared most about these missions.

[Paulus Invictus]

I'm trying hard to get my mind around that concept, but still don't know where the original, soft-ball sized object/particle came from before it exploded into space. What's the theory? Socrates said, "I only know that I know nothing," and he was right. Neither do we.

[RightWhale]

There may be something misleading about that diagram. Inflation moved the grid itself, but expansion is moving the objects against the grid. Seems like two different processes.

[longshadow]

LOL, all 92 pages might take a while.

That was but one reason why I only skimmed it, and then skipped straight to "CONCLUSIONS" when looking for something from it to post here.

This paper stands as a refutation to anybody who says there's no value in unmanned space missions. This one mission has completely realigned our understanding of the universe, and done it with solid fact. Many ships of faith and fancy will rip their bellies open on this hard rock of truth.

But then, that's what the science-haters feared most about these missions.

Nicely stated. Inflationary Cosmology wins another round. Speaking of which, I think the article goes into details of how several alternative models do stacking up against the evidence (I think I even saw a mention of MOND, though it might only have been for comic relief). If you get the chance to review that section of the paper, could you give the lay people here a "score card summary" on exactly which alternative cosmologies got gutted by the latest WMAP data and analysis?

[RightWingAtheist]

A good simplification of the WMAP results; it's too bad Carroll is a knee-jerk liberal airhead when it comes to politics and economics (he attacked Larry Summers' comments about women in science by saying they were so stupid, that only an economist would make them, while nodding his head when Krugman claimed conservatives are too stupid to be scientists, saying that all good academics are liberal by nature). Here's Lubos Motl's take on the data

[righttackle44]

"And, boy, was there ever light!"

True. True. True.

[BeHoldAPaleHorse]

Would you want to stand next to the marble-sized universe, if you could be assured of escaping to a safe distance before detonation?

Stand WAY back, there, sonny boy!

The last thing heard before the Big Bang: "Hold muh beer and watch this!"

[ExGeeEye]

Pardon my density...

Space is what is expanding.

Into what?

[RightWhale]

Into what?

Many of our problems come from asking one more question when it is best to stop while we still have some idea where we are.