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Topic: Cosmic background radiation


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In the News (Thu 23 May 19)

  
  Blackbody Radiation
A uniform background radiation in the microwave region of the spectrum is observed in all directions in the sky.
The discovery of the 3K microwave background radiation was one of the crucial steps leading to the calculation of the standard "Big Bang" model of cosmology, its role being that of providing estimates of relative populations of particles and photons.
The scale of the fluctuations is larger than the horizon at the time the background radiation was emitted, indicating that the fluctuations are primordial, dating from a time before the separation of radiation and matter, the transparency point.
hyperphysics.phy-astr.gsu.edu /hbase/bkg3k.html   (947 words)

  
 The Cosmic Background Radiation
The cosmic background radiation (sometimes called the CBR), is the afterglow of the big bang, cooled to a faint whisper in the microwave spectrum by the expansion of the Universe for 15 billion years (which causes the radiation originally produced in the big bang to redshift to longer wavelengths).
As shown in the adjacent intensity map of the background radiation in different directions taken by the Differential Microwave Radiometer on NASA's COBE satellite, it is not completely uniform, though it is very nearly so (Ref).
The highly isotropic nature of the cosmic background radiation indicates that the early stages of the Universe were almost completely uniform.
csep10.phys.utk.edu /astr162/lect/cosmology/cbr.html   (660 words)

  
  Cosmic microwave background radiation
The Cosmic Microwave Background Radiation is a form of electromagnetic radiation that fills the whole of the universe.
The CBR was predicted by George Gamow, Ralph Alpher, and Robert Hermann in the 1940s and was accidentally discovered in the 1964 by Penzias and Wilson, who received a Nobel Prize for this discovery.
Of these experiments, the Cosmic Background Explorer (COBE) satellite that was flown in 1989-1996 is probably the most famous and which made the first detection of the large scale anisotropies (other than the dipole).
www.infomutt.com /c/co/cosmic_microwave_background_radiation.html   (683 words)

  
  PlanetPhysics: cosmic microwave background radiation   (Site not responding. Last check: )
The cosmic microwave background was predicted by George Gamow, Ralph Alpher, and Robert Herman in 1948.
The interpretation of the cosmic microwave background was a controversial issue in the 1960s with some proponents of the steady state theory arguing that the microwave background was the result of scattered starlight from distant galaxies.
The period after the emission of the cosmic microwave background and before the observation of the first stars is semi-humorously referred to by cosmologists as the dark age, and is a period which is under intense study by astronomers (See 21 centimeter radiation).
planetphysics.org /encyclopedia/CosmicMicrowaveBackgroundRadiation.html   (3304 words)

  
 Cosmic microwave background radiation
The Cosmic Microwave Background Radiation is a form of electromagnetic radiation that fills the whole of the universe.
This radiation is regarded as the best available evidence of the Big Bang theory -- it gives a snapshot of the Universe when the temperature dropped enough to allow electrons and protons to form hydrogen atoms, thus making the universe transparent to radiation.
The CBR was predicted by George Gamow, Ralph Alpher, and Robert Hermann in the 1940s and was accidentally discovered in the 1950s by Penzias and Wilson, who received a Nobel Prize for this discovery.
www.ebroadcast.com.au /lookup/encyclopedia/cm/CMB.html   (464 words)

  
 Cosmic Background Radiation
The origin of this radiation depends on the region of the spectrum that we are observing.
Certainly the most famous component is the Cosmic microwave background radiation, a remainder of the epoch when the universe, still hot, became transparent for the first time to radiation.
There is also background radiation in the infrared, x-rays, etc., with different causes; most of these are ultimately attributable to unresolved individual sources.
www.ebroadcast.com.au /lookup/encyclopedia/co/Cosmic_background_radiation.html   (110 words)

  
 Research at KICP: Cosmic Background Radiations
Since this radiation was emitted at a specific time in the history of the expansion of the Universe it carries with it the signatures of the structure of the Universe at that epoch.
The radiation we receive from this population of protogalxies is further redshifted as it travels to us and is observable by telescopes at sub-mm wavelengths.
The Cosmic Infrared Background Radiation (CIB) is the integrated light from all such dust in the line-of-sight and not from protogalaxies at a specific redshift (unlike the CMB radiation).
cfcp.uchicago.edu /research/cosmicradiation   (823 words)

  
 COSMIC MICROWAVE BACKGROUND RADIATION.
A background radiation is also expected in a zero origin universe, but certainly not for the same reasons.
Background radiation curves can then be plotted within the parameters of, infinite background emissions of zero energy (1 x 0), and zero background emission in the present (0 x 1).
Because the dipole is taking the same picture of the cosmic background as the monopole, by default it has the same spectrum as the monopole.
members.optusnet.com.au /~maxkeon/cmbr.html   (1840 words)

  
 PhysicsCentral: Catch a Cosmic Microwave: New Findings
A trio of findings about cosmic background radiation may help explain why matter is irregularly distributed throughout the universe with the observed “large-scale structure” of galactic super-clusters.
Today's cosmic background radiation is a faint "echo" of the much more intense radiation that filled the universe several hundred thousand years after the Big Bang/inflation event when it had cooled just enough to permit ordinary (electrically neutral) matter to form.
The tiny hot and cold patches observed in the cosmic background radiation are not only the fading echoes of that awesome music of creation, they also suggest why stars and galaxies are arrayed as they are across the cosmos.
www.physicscentral.com /action/2001/microwave-cosmic.html   (998 words)

  
 COBE - Cosmic Background Explorer
NASA's COBE (Cosmic Bakground Explorer) satellite was developed to measure the diffuxe infrared and cosmic microwave background radiation from the early Universe to the limits set by our astrophysical environment.
These anisotropies are interpreted as imprints of the seeds that eventually grew under the influence of gravity to galaxies, clusters of galaxies, and clusters of clusters of galaxies.
FIRAS has shown that the cosmic microwave background spectrum matches that of a flbody of temperature 2.726K with a precision of 0.03% of the peak intensity over a wavelength range 0.1 to 5 mm.
aether.lbl.gov /www/projects/cobe   (520 words)

  
 Cosmic microwave background radiation Summary
Cosmic background radiation is a relic of one of these cosmological transitions, and it remains the best evidence to verify the big bang theory.
The cosmic microwave background is isotropic to roughly one part in 100,000: the root mean square variations are only 18 µK. The Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the NASA COsmic Background Explorer (COBE) satellite has carefully measured the spectrum of the cosmic microwave background.
The cosmic microwave background was predicted by George Gamow, Ralph Alpher, and Robert Hermann in 1948.
www.bookrags.com /Cosmic_microwave_background_radiation   (5849 words)

  
 Cosmic Microwave Background Radiation   (Site not responding. Last check: )
In addition to this cosmic microwave background radiation, the early universe was filled with hot hydrogen gas with a density of about 1000 atoms per cubic centimeter (a teaspoon is roughly 3 cubic centimeters).
The behavior of cosmic microwave background photons moving through the early universe is analogous to the propagation of optical light through the Earth's atmosphere.
Cosmologists studying the cosmic microwave background radiation can look through much of the universe back to when it was opaque: a view back to 500,000 years after the Big Bang.
vista.lbl.gov /~barnett/universe.adventure/cbr.htm   (901 words)

  
 Cosmology
The uniformity of the background radiation is evidence for the cosmological principle.
This background radiation is interpreted to be the relic of the early universe.
Notice that the background appears completely uniform at a temperature of 2.728 K. The colors for the temperatures range from blue for 2.724 K to red for 2.732 K. The double-lobe pattern shows the doppler effect from the motion of the Sun with respect to the background radiation.
www.astronomynotes.com /cosmolgy/s5.htm   (1289 words)

  
 Big Bang Theory - Origin of Universe - 0rig.in
The Big Bang theory predicted the existence of the cosmic microwave background radiation or CMB which is composed of photons emitted during baryogenesis.
Their discovery provided substantial confirmation of the general CMB predictions—the radiation was found to be isotropic and consistent with a flbody spectrum of about 3 K —and it pitched the balance of opinion in favor of the Big Bang hypothesis.
Using the Big Bang model it is possible to calculate the concentration of helium-4, helium-3, deuterium and lithium-7 in the Universe as ratios to the amount of ordinary hydrogen, H. All the abundances depend on a single parameter, the ratio of photons to baryons.
www.0rig.in /cosmology/big_bang_theory.htm   (4780 words)

  
 Cosmic Microwave Background Radiation
Cosmic Microwave Background Radiation (CMBR) is a messenger from this soup.
Primer matter was immersed in radiation (gamma rays, X rays, light) and they were constantly in interaction with those particles, then the universe get cool enough as for forming the atoms, and the radiation didn't interact again.
Figure: Radiation chart from shortly after big Bang, x axis corresponds to the frequency of the radiation, and the vertical axis to the intensity.
library.thinkquest.org /C0114565/content.php?id=191   (366 words)

  
 CBR96
The relic Cosmic Background Radiation (CBR) carries information on the physical conditions prevailing during the early phases of cosmic expansion, and thus represents an invaluable tool for reconstructing the general history of the Universe, and for the construction of a detailed model of galaxy formation.
These two lectures are intended to introduce some of the observational techniques used to study the cosmic microwave background radiation (CBR), to list some recent observational results, especially on CBR anisotropies, and to examine the implications of these results for cosmology and theories of astrophysical structure formation.
The Cosmic Microwave Background Radiation - Introduction to the CMBR in terms of intensity and anisotropy (DTa/DT) spectrum, foregrounds, measurement and brief history of early observations ending with a summary of the knowledge as of early 1992.
astro.u-strasbg.fr /cbr96.html   (1738 words)

  
 Temperature of the Cosmic Background Radiation
Going through different sources, I found the cosmic background radiataion varies from 2.7 K to 3 K. After further study, I believe the cosmic background radiation should be around 2.7 K because the texts that state this value give more accurate and detailed information than other texts.
All of my research sources agree that the cosmic background radiation must have been thermalized when the universe was denser and hotter than it is now.
To test these prediction, Antoinette Songaila of the Institute for Astronomy in Hawaii and her co-workers measured the temperature of the background radiation at a time corresponding to 4 billion years after the Big Bang.
hypertextbook.com /facts/1997/SilinYang.shtml   (506 words)

  
 Temperature of the Cosmic Background Radiation
Going through different sources, I found the cosmic background radiataion varies from 2.7 K to 3 K. After further study, I believe the cosmic background radiation should be around 2.7 K because the texts that state this value give more accurate and detailed information than other texts.
All of my research sources agree that the cosmic background radiation must have been thermalized when the universe was denser and hotter than it is now.
To test these prediction, Antoinette Songaila of the Institute for Astronomy in Hawaii and her co-workers measured the temperature of the background radiation at a time corresponding to 4 billion years after the Big Bang.
www.hypertextbook.com /facts/1997/SilinYang.shtml   (506 words)

  
 Radiation Technologies, Inc. Background and Qualifications
Radiation Technologies, Inc. (RTI) is a woman-owned small business that provides research, development and professional services to government, university, and industry customers.
Radiation Technologies specializes in design, fabrication and fielding of specialized systems for data acquisition where the application requirements are not well met by existing commercial systems.
Radiation Technologies often works with partners who provide subsystems and components which are integrated with additional electronics and software into a complete data acquisition system.
www.radiationtechnologies.com /background.html   (522 words)

  
 AllRefer.com - cosmic background radiation Information
Faint microwave radiation that penetrates space throughout the universe, postulated to be a residual effect of the Big Bang.
Cosmic background radiation was first detected in 1965 by US physicists Arno Penzias and Robert Wilson, who in 1978 shared the Nobel Prize for Physics for their discovery.
In 1992 the US Cosmic Background Explorer satellite detected slight ‘ripples’ in the strength of cosmic background radiation that are believed to mark the first stage in the formation of galaxies.
www.allrefer.com /cosmic-background-radiation   (239 words)

  
 Research: Cosmic X-Ray Background Radiation
The cosmic X-ray background (XRB), like the cosmic microwave background (CMB), is radiation which originates at high redshift and has an extremely uniform distribution of intensity across the sky, which is to say it is extremely isotropic.
CMB radiation is a `relic' from a time when the Universe was hot and dense enough for baryonic matter (made of protons, neutrons, and electrons) and radiation to exist in a state of thermal equilibrium with each other.
AGN are the best candidates for the source of the X-ray background because at low redshift (nearby), where there are fewer of them and they are bright enough for us to examine their individual high-energy spectra in detail, we see that they produce radiation which is almost as hard as the X-ray background itself.
www.astro.uiuc.edu /~pmricker/research/xrb   (858 words)

  
 WMAP Cosmology 101: Cosmic Microwave Background
The existence of the CMB radiation was first predicted by George Gamow in 1948, and by Ralph Alpher and Robert Herman in 1950.
Today, the CMB radiation is very cold, only 2.725° above absolute zero, thus this radiation shines primarily in the microwave portion of the electromagnetic spectrum, and is invisible to the naked eye.
In addition to this cosmic microwave background radiation, the early universe was filled with hot hydrogen gas with a density of about 1000 atoms per cubic centimeter.
map.gsfc.nasa.gov /m_uni/uni_101bbtest3.html   (1150 words)

  
 SPACE.com -- NASA Satellite to Probe Big Bang
During its two-year mission, it would map the temperature of the background radiation at points across the sky to an accuracy of a millionth of one degree, with resolution some 30 times higher than that of the COBE craft.
The background radiation varies very slightly in temperature depending on where in the sky it comes from.
The hotter radiation reflects the size and density of the regions that gave birth to galaxies.
www.space.com /scienceastronomy/solarsystem/cosmic_background_000524.html   (1083 words)

  
 The Cosmic Microwave Background
Arno Penzias and Robert Wilson detected a background "noise" in the microwave range of the electromagnetic spectrum.
Some people think of the big bang in terms of the explosion of dynamite in which radiation travels faster than the matter (the stick of dynamite) and escapes it; however, radiation created from the big bang is quite different.
Until the observation of the cosmic microwave background by Penzias and Wilson, the only observational evidence of a big bang was the red shift (See The Doppler Effect) observed by Edwin Hubble.
library.thinkquest.org /27930/cosmic_background.htm   (863 words)

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