The CBI observed the cosmic microwave background, a snapshop of the universe at 300,000 years old.
Posted on 05/24/2002 8:20:10 AM PDT by callisto
Physicists from the Universities of Cambridge and Manchester and the Instituto de Astrofisica de Canarias in Tenerife have released the first results of new high-precision observations of the relic radiation from the Big Bang, often called the cosmic microwave background or CMB. These observations have been made with a novel radio telescope called the Very Small Array (VSA) situated on the Mount Teide in Tenerife. The images show the beginnings of the formation of structure in the early Universe. From the properties of the image, scientists can obtain vital information on just what happened in the early universe and distinguish between competing cosmological theories.
Radiation from the Big Bang fireball has been travelling across the universe, cooling as space expands. Today, we see the faint relic radiation in all directions on the sky at a temperature of just 3 degrees centigrade above absolute zero, giving a picture of the universe when it was less than one 50,000th of its present age. Because galaxies must have formed out of the primeval fireball, astrophysicists have predicted that they will have left imprints in the radiation. Across the sky, there should be tiny variations in the temperature of the relic radiation. However, these ripples are very weak---only one 10,000th of a degree C.
During its first year of operation the VSA has observed three patches of sky, each some 8 x 8 degrees across. It can see detail down to one third of a degree, well matched to the typical size of interesting temperature variations. The VSA has 14 aerials, each somewhat akin to a satellite TV dish but only 15 cm across. The signals from each aerial are combined, forming an interferometric array - a technique pioneered by Cambridge physicists. The array is able to filter out unwanted terrestrial and atmospheric radiation allowing the the extremely faint CMB sky signal common to all the aerials to be detected. This approach allows high precision observations to be made at modest cost - the capital cost of the VSA was 2.6 million GBP. The performance of the VSA also results from using advanced receivers built at Manchester University and from the outstanding atmospheric conditions at the 2.4 km high Teide Observatory on Tenerife. The VSA can therefore measure specific, individual structures in the relic radiation with great precision.
A small number of other experiments have made similar observations. The different experiments work in different ways and face different challenges and sources of error; a key advantage of this diversity is that if their results agree, one can be confident that they are correct. One special strength of the VSA is that it is an interferometer array; another is that it is able to robustly remove the contaminating radiation from radiogalaxies and quasars that lie between us and the CMB relic radiation. The VSA results provide amazing confirmation of the current picture of the Universe.
The VSA observations of the CMB released today reveal the following properties of our Universe:
1) The curvature of space is close to zero -- we live in a spatially 'flat' universe.
2) The material in the universe is dominated by dark matter.
3) There is direct evidence for 'vacuum dark energy' which is currently not well understood, but is causing the universe to accelerate.
4) There are multiple peaks in the CMB power spectrum. This is direct evidence that all the structure in the universe today is due to microscopic quantum-mechanical fluctuations, inflated to astronomical size in the very early universe.
Astronomers operating from a remote plateau in the Chilean desert have produced the most detailed images ever made of the oldest light emitted by the universe, providing independent confirmation of controversial theories about the origin of matter and energy.
Pushing the limits of available technology, the Cosmic Background Imager (CBI) funded by the National Science Foundation (NSF) and California Institute of Technology (Caltech) detected minute variations in the cosmic microwave background, the radiation that has traveled to Earth over almost 14 billion years. A map of the fluctuations shows the first tentative seeds of matter and energy that would later evolve into clusters of hundreds of galaxies.
The measurements also provide independent evidence for the long-debated theory of inflation, which states that the universe underwent a violent expansion in its first micro-moments. After about 300,000 years it cooled enough to allow the seeds of matter to form and became "transparent," allowing light to pass through. CBI observed remnants of that early radiation. The data are also helping scientists learn more about the repulsive force called "dark energy" that appears to defy gravity and force the universe to accelerate at an ever-increasing pace.
"This is basic research at its finest and most exciting," said NSF Director Rita Colwell. "Each new image of the early universe refines our model of how it all began. Just as the universe grows and spreads, humankind's knowledge of our own origins continues to expand, thanks to the technical expertise and patient persistence of scientists such as these."
"We have seen, for the first time, the seeds that gave rise to clusters of galaxies, thus putting theories of galaxy formation on a firm observational footing," said team leader Anthony Readhead of Caltech. "These unique high-resolution observations provide a new set of critical tests of cosmology, and provide new and independent evidence that the universe is flat and is dominated by dark matter and dark energy."
The CBI observed the cosmic microwave background, a snapshop of the universe at 300,000 years old.
Credit: CBI/Caltech/NSF
The CBI consists of 13 radio antennas located on a plateau at 5,080 meters (16,700 feet) in Chile's Atacama Desert.
Credit: CBI/Caltech/NSF
Readhead, with Caltech colleagues Steve Padin and Timothy Pearson and others from Canada, Chile and the United States, generated the finest measurements to date of the cosmic microwave background. Cosmic microwave background (CMB) is a record of the first photons that escaped from the rapidly cooling, coalescing universe about 300,000 years after the cosmic explosion known as the Big Bang that is commonly believed to have given birth to the universe.
Data from the CBI on temperature distributions in the CMB support a modification of the Big Bang theory; that modification is called inflation theory. Inflation states that the hot plasma of the initial universe underwent an extreme and rapid expansion in its first 10 -32 second. The variations in temperature measured by the CBI are as small as 10 millionths of a degree.
By plotting the peaks of temperature distribution, the scientists showed that the precise CBI data are entirely consistent with inflation and confirm earlier findings by other scientists. In April 2000, an international team of cosmologists led by Caltech's Andrew Lange announced the first compelling evidence that the universe is flat-that is, its geometry is such that parallel lines will neither converge or diverge. Lange's team observed at a different frequency from CBI, using a high-altitude balloon flown over Antarctica.
Since then, two other teams -- using independent methods -- have revealed their analyses of the very faint variations in temperature among the cosmic microwaves. The four instruments have conducted precise measurements of parameters that cosmologists have long used to describe the early universe. Each set of data has offered new clues to the form of the embryonic plasma and has drawn scientists closer to definitive answers. NSF has supported the work of all four teams and their instruments, some of them for more than 15 years.
Five papers on the CBI data were submitted today to the Astrophysical Journal for publication.
The CBI consists of 13 interferometers mounted on a 6-meter-diameter platform, operating at frequencies from 26 GHz to 36 GHz. Located in the driest desert in the world -- the Atacama -- CBI takes advantage of the low humidity at an altitude of 5,080 meters (16,700 feet). NSF has supported the CBI research since 1995. The National Council of Science and Technology of Chile provided the CBI site.
-NSF-
For more information and images, see: http://www.nsf.gov/od/lpa/news/advance/pr0241_images.htm and http://www.astro.caltech.edu/~tjp/CBI/
Happy reading!
I usually stop reading right about there. There wasn't any big bang.
The rest of your life should teach you very little.
Alan Guth's book "The Inflationary Universe" explains the necessity for "flatness" fairly clearly. If this universe weren't nearly perfectly flat, we wouldn't be here. It might be that nothing would be here.
TIME CUBE .
The Earth is Not Moving!.
Earth Orbits? Moon Landings? A Fraud! .
Flat Earth Society Homepage! .
Christian Answers Network.
Creationists' Cartoons .
Institute for Creation Research.
The Current State of Creation Astronomy.
Answers In Genesis .
THE MOON: A Propaganda Hoax .
CRANK DOT NET.
[The universe is flat; so is my girlfriend. Coincidence?]
As a theistic evolutionist, I agree with you that God created the heavens and the earth, and that that is the "bottom line." Unlike some others, though, I don't think God wants us to stop there; he gave us brains for a reason. I am fascinated by studies such as this, which give us a glimpse into how God created the heavens and the earth.
For your sake, I hope she doesn't lurk here. (I'll bet that, when she's around, you describe her as "willowy.")
The correct term, consistent with our understanding of the universe, is "cosmic."
But don't you find that a little, well, sketchy? Presumably He could have decreed a different universe, in which case, His exact decree would have been worded differently.
So therefore you're necessarily hiding a great deal of verbiage in those ellipses. Since the book of Nature is far longer than the book of Genesis, He must have given us an abridged version. (I'm agnostic on this issue of whether that was to save papyrus or our attention spans.) So if we want to know what he really said, we have to read the book of Nature to find out. But then, there's really no point in opening the cover if we aren't prepared to accept what we read there.
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