[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
starship-design: [Fwd: Spider-web sensor reveals a flat universe]
Well, folks, Earth may not be flat, but the universe apparently is. I'm
not sure what this means, but it's pretty cool.
JPLNews@jpl.nasa.gov wrote:
> MEDIA RELATIONS OFFICE
> JET PROPULSION LABORATORY
> CALIFORNIA INSTITUTE OF TECHNOLOGY
> NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
> PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
> http://www.jpl.nasa.gov
>
> Contact: Michelle Viotti (818) 354-8774
>
> FOR IMMEDIATE RELEASE April 26, 2000
>
> SPIDER-WEB SENSOR REVEALS A FLAT UNIVERSE
>
> Inspired by the elegant efficiency of spider webs,
> researchers at NASA's Jet Propulsion Laboratory (JPL), Pasadena,
> Calif., have designed a tiny, web-shaped sensor that maps faint
> structures in the early universe, reinforcing theories that the
> cosmos is flat in its geometry.
>
> (A NASA news release describing the overall results may be found
> at ftp://ftp.hq.nasa.gov/pub/pao/pressrel/2000/00-067.txt .)
>
> Carried on an internationally sponsored balloon experiment
> called BOOMERANG (Balloon Observations of Millimetric
> Extragalactic Radiation and Geophysics), the dime-sized sensor
> known as a "micromesh bolometer" is a prime example of NASA's
> success in developing miniaturized, high-performance technologies
> for space missions.
>
> "Just as spiders spin their webs with the least amount of
> silk possible, we were able to eliminate 99 percent of the
> material used by conventional bolometers," said Dr. James Bock,
> who led in the detector's development at JPL's Microdevices
> Laboratory. "The supporting material for our detector even has
> the same thickness as a strand in a spider's web -- about one
> micron thick, or one hundred times finer than a human hair."
>
> Using advanced micro-machining techniques, each section of
> the sensor's web was designed to be smaller than the millimeter
> wavelength of radiation streaming in from the cosmic microwave
> background. Created when the first atoms formed in the early
> universe, the cosmic microwave background has cooled a thousand
> times from its original temperature -- comparable to the hot
> surface of the Sun -- to the cold, faint radiation seen today.
>
> While the cosmic microwave background is almost perfectly
> uniform in all directions, the sensitivity of JPL's bolometer
> allows scientists to capture temperature variations of only 100-
> millionths of a degree (0.0001 C) in just a few seconds of
> observing time.
>
> "That's sensitive enough to detect the heat given off by a
> coffee maker all the way from the Moon," said Bock.
>
> By measuring one small patch of sky after another over
> several days of observation, the bolometers plot a map of the
> cosmic background radiation, providing a snapshot of the universe
> when the radiation formed about 300,000 years after the Big Bang.
> At this time, regions with a higher density of matter and energy
> left a record in the background radiation. Wherever dense
> regions existed, they left a faint imprint of slightly higher
> temperatures. These fluctuations in the background serve as a
> kind of fingerprint, allowing scientists to discriminate between
> theories of cosmic development.
>
> With the bolometer's high level of sensitivity, the
> BOOMERANG project was able to reveal density patterns in the
> young universe that are consistent with an inflationary theory of
> cosmic development. This theory proposes that, in the first
> moments after the Big Bang, the universe went through a period of
> extreme, exponential inflation. The theory further predicts a
> "flat" geometry for the universe, because the immense stretching
> of space during an inflationary period would have removed any
> initially strong curvature in the smaller and denser early
> universe.
>
> "Think of it this way," explains Bock. "If we were to
> balance on a large ball, we would certainly feel the curvature
> beneath our feet. Expand that ball to the size of the Earth, and
> we experience that space as flat. Now think about blowing up
> that ball to a cosmic scale, and you can imagine how inflation
> would vastly flatten the visible universe."
>
> To test cosmic development theories even further, future JPL
> bolometers will fly on the European Space Agency's Far Infrared
> and Submillimetre Telescope (FIRST) and Planck missions, both
> scheduled for launch in 2007. Using bolometers with 10 times
> higher performance, Planck is expected to provide the definitive
> map of variations in the cosmic microwave background, while FIRST
> will survey some of the earliest galaxies. In the meantime,
> scientists will be studying the BOOMERANG map over the next few
> years to gain a better understanding of the nature and
> composition of matter in the universe.
>
> The BOOMERANG results were obtained through a balloon
> experiment in 1998 that carried JPL's bolometer in a sensitive
> receiver 36 kilometers (23 miles) above the atmosphere in
> Antarctica. Because Antarctica provides 24-hour sunlight and
> winds that blow in a circular pattern around the continent, the
> balloon experiment was able to maintain continuous measurements
> over a 10-1/2 day period.
>
> The scientific results will be published in the April 27
> issue of Nature. Information on the BOOMERANG project can be
> found at http://www.physics.ucsb.edu/~boomerang and
> http://oberon.roma1.infn.it/boomerang . For images of JPL's
> micromesh bolometer and its results, see
> http://www.jpl.nasa.gov/pictures/boomerang .
>
> The BOOMERANG Project was led by Dr. Andrew Lange of the
> California Institute of Technology and by Dr. Paolo DeBernardis
> of the University of Rome La Sapienza. Primary funding for
> BOOMERANG was provided by the National Science Foundation and
> NASA in the United States; the Italian Space Agency, the Italian
> Antarctic Research Programme and the University of Rome La
> Sapienza in Italy; and the Particle Physics and Astronomy
> Research Council in the United Kingdom. The Department of
> Energy's National Energy Research Supercomputing Center provided
> high-level computer analysis of the data.
>
> The Microdevices Laboratory is a state-of-the-art research
> and technology-development facility in the Center for Space
> Microelectronics Technology at JPL. Funding for the micromesh
> bolometer came from JPL's Technology and Applications Programs
> Directorate. JPL is managed by Caltech on behalf of NASA.
>
> #####
> 4/26/00 MV
> #00-40
>
> ---------------------------------------------------------------
> You are subscribed to JPL's news mailing list. To unsubscribe,
> please send an e-mail to JPLNews@jpl.nasa.gov and in the body
> of the message include the following line.
>
> unsubscribe news
>
> Please do not reply to this e-mail.
> For help, send a message to listmaster@www.jpl.nasa.gov.