Posted on 03/16/2006 11:31:54 AM PST by 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.
Arrrgggg.... Clearly flawed in your mind only.
I think the answer is 42.
The context is the equation in this case. The Hubble constant is a constant in a very specific relation, the slope of this line:
That's it. Nothing else. Anyone that says otherwise is feeding you a line.
I found it 'upsetting' at first, until I learned to understand it a little better. (I'm not an expert at this stuff - Radio Astronomer is probably a better bet - I've had one grad level course in G.R. and a lot of particle physics, but that's about it.)
Apparently, in the inflationary model, there can be regions located outside our own observable 'bubble' as a result of the inflationary epoch, traveling away from us at (an apparent) 'faster' than light, but since we are forever causally disconnected from those regions, it doesn't really matter. Relativity's limit still holds from any observable point.
(One day, I'll understand this better myself, I hope.)
Ummm.... You may want to do just a wee bit more research prior to posting this stuff anymore.
Just a suggestion.
Do the math:
H_0=71(km/s)/megaparsec
d= 1 AU = 4 * 10^-12 Megaparsecs
v=128 *10 ^-12 km/s=1.28 *10^-10 km/s
that's a pretty small effect at that distance, and the effect of gravity pretty effectively overwhelms it.
However, local regions bound by gravity, do not exhibit H.
That can always be done. One just sticks on an "extra" dimension. Sort of like combining electromagnetism and gravity into a 5 or 6 dimensional system. It's not very interesting because there's still no coupling between the systems. If one sticks a Fifth Dimension for the universise to "expand" into, it adds nothing to the actual physics. This contrasts with using time as a fourth dimension in relativity theory where new, observable physics results.
It's not wrong, it's just not particularly useful.
I always thought that's because the effect was so small no one would notice. Huh, I just double checked, and you are right. Thanks. You learn something new everyday!
Interesting read:
http://en.wikipedia.org/wiki/Robertson-Walker_metric
I have to dash to work. :-(
Sigh.
:-)
Indeed. Even at galactic scales. :-)
At this point in the thread, I figured sci-fi fantasy interjection was appropriate.
But there you go getting us back on sound scientific footing. I'll bet this thread goes for another hundred posts as the attempt is made to defend previous fantasies. ;)
Actually, I was thinking of it in terms of quantization of space. Yes, I know it's theoretical, but the checkerboard analogy is more in tune with that than making the squares bigger. If you make the squares bigger, then there is still the same number of squares between pieces. In checkers, you can have only one square per piece so adding squares is analogos to adding space, but the squares would have to be homogeneously added. The hard part for many people to get their heads around is that distance is measured in space, but it is not a measurement of space.
Yes, I would agree that that is true. However, even if the expansion was going on, we couldn't detect it.
Are you sure? It may give a common coordinate system to make the math easier.
If I measure positions on the Earth with lat/lon, I get funny coordinate singularities (North and South poles), but if I use quaternions (extra dimension) there are no singularity issues.
How long before we get to the "it's only a theory," argument?
That's for amateurs. The recommended challenge is: "Where you there?"
my-subatomic-particles-were placemarker
Do you suppose that an attempt by someone to observe the singularity could have caused the Big Bang?
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