Arno Penzias and Robert Wilson - Bell Labs, Holmdel, NJ Arno Penzias and Robert Wilson Bell Labs, Holmdel, NJ More The Large Horn Antenna and the Discovery of Cosmic Microwave Background Radiation As part of the APS historic sites initiative, on December 9, 2008, APS Vice-President Curtis Callan presented a plaque to Bell Labs to commemorate the discovery of the Cosmic Microwave Background Radiation (CMB) that provided evidence for the Big Bang. Bell Labs radio astronomers Arno Penzias and Robert Wilson were using a large horn antenna in 1964 and 1965 to map signals from the Milky Way, when they serendipitously discovered the CMB. As written in the citation, "This unexpected discovery, offering strong evidence that the universe began with the Big Bang, ushered in experimental cosmology." Penzias and Wilson shared the Nobel Prize in Physics in 1978 in honor of their findings. The CMB is "noise" leftover from the creation of the Universe. The microwave radiation is only 3 degrees above Absolute Zero or -270 degrees C, 1 and is uniformly perceptible from all directions.

Its presence demonstrates that that our universe began in an extremely hot and violent explosion, called the Big Bang, 13.7 billion years ago. In 1960, Bell Labs built a 20-foot horn-shaped antenna in Holmdel, NJ to be used with an early satellite system called Echo. The intention was to collect and amplify radio signals to send them across long distances, but within a few years, another satellite was launched and Echo became obsolete. 2 With the antenna no longer tied to commercial applications, it was now free for research. Penzias and Wilson jumped at the chance to use it to analyze radio signals from the spaces between galaxies. 3 But when they began to employ it, they encountered a persistent "noise" of microwaves that came from every direction. If they were to conduct experiments with the antenna, they would have to find a way to remove the static. Penzias and Wilson tested everything they could think of to rule out the source of the radiation racket. They knew it wasn’t radiation from the Milky Way or extraterrestrial radio sources. They pointed the antenna towards New York City to rule out "urban interference", and did analysis to dismiss possible military testing from their list.

4 Then they found droppings of pigeons nesting in the antenna. They cleaned out the mess and tried removing the birds and discouraging them from roosting, but they kept flying back. "To get rid of them, we finally found the most humane thing was to get a shot gun…and at very close range [we] just killed them instantly. It’s not something I’m happy about, but that seemed like the only way out of our dilemma," said Penzias. 5 "And so the pigeons left with a smaller bang, but the noise remained, coming from every direction." 6 At the same time, the two astronomers learned that Princeton University physicist Robert Dicke had predicted that if the Big Bang had occurred, there would be low level radiation found throughout the universe. Dicke was about to design an experiment to test this hypothesis when he was contacted by Penzias. Upon hearing of Penzias’ and Wilson’s discovery, Dicke turned to his laboratory colleagues and said "well boys, we’ve been scooped." 7 Although both groups published their results in Astrophysical Journal Letters, only Penzias and Wilson received the Nobel Prize for the discovery of the CMB.

The horn antenna was designated a National Historic Landmark in 1990. Its significance in fostering a new appreciation for the field of cosmology and a better understanding of our origins can be summed up by the following: "Scientists have labeled the discovery [of the CMB] the greatest scientific discovery of the 20th century." 8 ©2009, Alaina G. Levine BBC - Universe - Arno Penzias and Robert Wilson (pictures, video, facts & news) Arno Penzias and Robert Wilson Arno Penzias and Robert Wilson Arno Penzias and Robert Wilson In the mid-1960s, Arno Penzias and Robert Wilson detected leftover, cooled down radiation from early in the Universe's history by carefully scanning the sky with a device called the Holmdel Horn Antenna . Their discovery was of huge importance to cosmology and won them the Nobel prize. This cosmic microwave background radiation was later mapped in greater detail by NASA's Cosmic Background Explorer (COBE) mission in the early 1990s and the Wilkinson Microwave Anisotropy Probe (WMAP), launched in 2001.

Image: Arno Penzias (left) and Robert Wilson in 1978 outside the Holmdel horn antenna (credit: Physics Today Collection/AIP/SPL) Watch and listen to clips from past programmes TV clips [2] Cosmic microwave background radiation discovered Scientists map the early Universe. The astronomers Arno Penzias and Robert Wilson discovered the cosmic microwave background (CMB) radiation by chance in the mid-1960s while using the Holmdel Horn Antenna in New Jersey to map the sky. The CMB was later mapped with satellites, including the WMAP probe. The Holmdel Horn Antenna Arno Penzias talks about detecting ancient cosmic radiation. Arno Penzias describes observations (made with Robert Wilson) using the Holmdel Horn Antenna. These observations would later be identified as the cosmic microwave background radiation (CMB). About Arno Penzias and Robert Wilson The accidental discovery of cosmic microwave background radiation in 1964 is a major development in modern physical cosmology.

Although predicted by earlier theoretical work around 1950, it was first discovered accidentally by American radio astronomers Arno Penzias and Robert Woodrow Wilson as they experimented with the Holmdel Horn Antenna. The discovery was important evidence for a hot early Universe (big bang theory) and was evidence against the rival steady state theory. In 1978, Penzias and Wilson were awarded the Nobel Prize for Physics for their joint discovery. A Science Odyssey: People and Discoveries: Penzias and Wilson discover cosmic microwave radiation Penzias and Wilson discover cosmic microwave radiation 1965 Photo: Holmdel satellite antenna Bell Labs built a giant antenna in Holmdel, New Jersey, in 1960. It was part of a very early satellite transmission system called Echo. By collecting and amplifying weak radio signals bounced off large metallic balloons high in the atmosphere, it could send signals across long distances. Within a few years, the Telstar satellite was launched. It had built-in transponders and made the Echo system obsolete. Meanwhile, two employees of Bell Labs had had their eye on the antenna. Arno Penzias (b.

1933), a German-born radio astronomer, joined Bell Labs in 1958. He had done his PhD on using masers (microwave amplification by stimulated emission of radiation) to amplify and measure radio signals from the spaces between galaxies. He knew the Holmdel antenna would also make a great radio telescope and was dying to use it to continue his observations, but he pursued other research while the antenna was booked for commercial use. Another radio astronomer came to Bell Labs in 1962 with the same idea. Robert Wilson (b. 1936) had also used masers to amplify weak signals in mapping radio signals from the Milky Way. The launch of Telstar in 1962 gave both researchers what they wanted: the Holmdel antenna was freed up for pure research. When they began to use it as a telescope they found there was a background "noise" (like static in a radio). This annoyance was a uniform signal in the microwave range, seeming to come from all directions. Everyone assumed it came from the telescope itself, which was not unusual. It hadn't interfered with the Echo system but Penzias and Wilson had to get rid of it to make the observations they planned.

They checked everything to rule out the source of the excess radiation. They pointed the antenna right at New York City -- it wasn't urban interference. It wasn't radiation from our galaxy or extraterrestrial radio sources. It wasn't even the pigeons living in the big, horn-shaped antenna. Penzias and Wilson kicked them out and swept out all their droppings. The source remained the same through four seasons, so it couldn't have come from the solar system or even from a 1962 above-ground nuclear test, because in a year that fallout would have shown a decrease. They had to conclude it was not the machine and it was not random noise causing the radiation. Penzias and Wilson began looking for theoretical explanations. Around the same time, Robert Dicke (1916�1997) at nearby Princeton University had been pursuing theories about the big bang. He had elaborated on existing theory to suggest that if there had been a big bang , the residue of the explosion should by now take the form of a low-level background radiation throughout the universe. Dicke was looking for evidence of this theory when Penzias and Wilson got in touch with his lab.

He shared his theoretical work with them, even as he resignedly said to his fellow-researchers, "We've been scooped." Ironically, Robert Wilson had been trained in steady state theory (which suggested the universe was without beginning or end, unlike big bang theory), and he felt uncomfortable with the big bang explanation of their radio noise. When he and Penzias jointly published their research with Dicke, the Bell Lab researchers stuck to "just the facts" -- simply reporting their recorded observations. It is ironic, too, that many researchers -- both theoretical and experimental -- had stumbled on this phenomenon before, but either discounted it or never put it all together. This was partly because, as Steven Weinberg wrote, "in the 1950s, the study of the early universe was widely regarded as not the sort of thing to which a respectable scientist would devote his time." Since Penzias, Wilson, and Dicke's work, all that has changed. The measurement of cosmic background radiation (as the Holmdel telescope's noise is now called), combined with Edwin Hubble 's much earlier finding that the galaxies are rushing away, makes a strong case for the big bang.

By the mid 1970s, astronomers called it "the standard model." Arno Penzias and Robert Wilson received the Nobel Prize in physics in 1978. Why Cosmic Background Radiation Demonstrates the Universe Had a Beginning | Cold Case Christianity Why Cosmic Background Radiation Demonstrates the Universe Had a Beginning PDF In 1964, two American physicists and radio astronomers, Arno Penzias and Robert Wilson, made an important discovery. They were unable to eliminate the radio signal “noise” from their large antenna at the Bell Telephone Laboratories in New Jersey, regardless of where in the universe they tried to point their instrument. They consulted with colleagues to determine the cause of this noise. Another physicist suggested the noise might not be coming from the antenna at all. Instead they might be detecting the residual background radiation caused when the universe first came into being. Penzias and Wilson proved this to be correct, winning a Nobel Prize for their discovery in 1978. Numerous additional experiments and observations have since established the existence of cosmic background radiation, including data from the Cosmic Background Explorer satellite launched in 1989, and the Planck space observatory launched in 2009.

For many scientists, this discovery solidified their belief the universe had a beginning . An illustration may be helpful. I served for three years on our SWAT unit, and during that time, we were repeatedly asked to flush out barricaded suspects. We employed a “flashbang” grenade in nearly all these SWAT entries. These are designed, of course, to “flash” and “bang”; they make a lot of noise, light and heat. We typically threw a grenade in the room where the suspect was barricaded (usually through a window). When the grenade hit the ground, it exploded violently, lighting the room, deafening the suspect, and filling the space with debris and heat. In that instant, as the suspect was distracted, our team came in from the opposite corner. Flashbangs are excellent distraction devices because they leave a lingering impact in the space where they are deployed. Illustrations from God’s Crime Scene In a similar way, if the universe leapt into existence, expanding from a state of tremendous heat, density and expansion, we should expect find evidence of lingering impact. The cosmic background radiation is the residual evidence of this cosmic “flashbang.” The pervasive radiation testifies to the extreme environment at the earliest moments of the universe.

Of course the Cosmic Background radiation, in and of itself, doesn’t demonstrate conclusively the universe had a beginning. But when this single piece of evidence is assembled with other important pieces of evidence I’ve described in God’s Crime Scene , the cumulative case is overwhelming: Why Cosmic Background Radiation Demonstrates the Universe Had a Beginning by J Warner Wallace In 1964, two American physicists and radio astronomers, Arno Penzias and Robert Wilson, made an important discovery. They were unable to eliminate the radio signal “noise” from their large antenna at the Bell Telephone Laboratories in New Jersey, regardless of where in the universe they tried to point their instrument. They consulted with colleagues to determine the cause of this noise. Another physicist suggested the noise might not be coming from the antenna at all. Instead they might be detecting the residual background radiation caused when the universe first came into being. Penzias and Wilson proved this to be correct, winning a Nobel Prize for their discovery in 1978. Numerous additional experiments and observations have since established the existence of cosmic background radiation, including data from the Cosmic Background Explorer satellite launched in 1989, and the Planck space observatory launched in 2009.

For many scientists, this discovery solidified their belief the universe had a beginning . An illustration may be helpful. I served for three years on our SWAT unit, and during that time, we were repeatedly asked to flush out barricaded suspects. We employed a “flashbang” grenade in nearly all these SWAT entries. These are designed, of course, to “flash” and “bang”; they make a lot of noise, light and heat. We typically threw a grenade in the room where the suspect was barricaded (usually through a window). When the grenade hit the ground, it exploded violently, lighting the room, deafening the suspect, and filling the space with debris and heat. In that instant, as the suspect was distracted, our team came in from the opposite corner. Flashbangs are excellent distraction devices because they leave a lingering impact in the space where they are deployed. In a similar way, if the universe leapt into existence, expanding from a state of tremendous heat, density and expansion, we should expect find evidence of lingering impact.

The cosmic background radiation is the residual evidence of this cosmic “flashbang.” The pervasive radiation testifies to the extreme environment at the earliest moments of the universe… FOLLOW THE LINK BELOW TO READ THE FULL ARTICLE >>> National Park Service: Astronomy and Astrophysics (Horn Antenna) Astronomy and Astrophysics Horn Antenna  Holmdel, New Jersey. Horn Antenna, circa 1960. Horn Antenna (Horn Reflector Antenna) Location: National Register: science, NHL: science, Subtheme: physical science, Facet: astronomy Builder: Mr. A. B. Crawford DESCRIPTION The Horn Antenna at Bell Telephone Laboratories in Holmdel, New Jersey, was constructed in 1959 to support Project Echo--the National Aeronautics and Space Administration's passive communications satellite project. [ 1 ] The antenna is 50 feet in length with a radiating aperture of 20 x 20 feet and is made of aluminum. The antenna's elevation wheel is 30 feet in diameter and supports the weight of the structure by means of rollers mounted on a base frame. All axial or thrust loads are taken by a large ball bearing at the apex end of the horn.

The horn continues through this bearing into the equipment cab. The ability to locate receiver equipment at the apex of the horn, thus eliminating the noise contribution of a connecting line, is an important feature of the antenna. A radiometer for measuring the intensity of radiant energy is found in the equipment cab. The triangular base frame of the antenna is made from structural steel. It rotates on wheels about a center pintle ball bearing on a track 30 feet in diameter. The track consists of stress-relieved, planed steel plates which are individually adjusted to produce a track flat to about 1/64 inch. The faces of the wheels are cone-shaped to minimize sliding friction. A tangential force of 100 pounds is sufficient to start the antenna in motion. To permit the antenna beam to be directed to any part of the sky, the antenna is mounted with the axis of the horn horizontal. Rotation about this axis affords tracking in elevation while the entire assembly is rotated about a vertical axis for tracking in the azimuth. With the exception of the steel base frame, which was made by a local steel company, the antenna was fabricated and assembled by the Holmdel Laboratory shops under the direction of Mr. H. W.

Anderson, who also collaborated on the design. Assistance in the design was also given by Messrs. R. O'Regan and S. A. Darby. Construction of the antenna was completed under the direction of Mr. A. B. Crawford from Freehold, New Jersey. When not in use, the antenna azimuth sprocket drive is disengaged, thus permitting the structure to "weathervane" and seek a position of minimum wind resistance. The antenna was designed to withstand winds of 100 miles per hour and the entire structure weighs 18 tons. The Horn Antenna combines several ideal characteristics it is extremely broad-band, has calculable aperture efficiency, and the back and sidelobes are so minimal that scarcely any thermal energy is picked up from the ground. Consequently it is an ideal radio telescope for accurate measurements of low levels of weak background radiation. A plastic clapboarded utility shed 10 x 20 feet, with two windows, a double door and a sheet metal roof, is found next to the Horn Antenna. This structure houses equipment and controls for the Horn Antenna and is included in this nomination.

SUMMARY The Horn Antenna, at the Bell Telephone Laboratories in Holmdel, New Jersey, is significant because of its association with the research work of two radio astronomers, Dr. Arno A. Penzias and Dr. Robert A. Wilson. In 1965 while using the Horn Antenna, Penzias and Wilson stumbled on the microwave background radiation that permeates the universe. Cosmologists quickly realized that Penzias and Wilson had made the most important discovery in modern astronomy since Edwin Hubble demonstrated in the 1920s that the universe was expanding. This discovery provided the evidence that confirmed George Gamow's and Abbe Georges Lemaitre's "Big Bang" theory of the creation of the universe and forever changed the science of cosmology--the study of the history of the universe--from a field for unlimited theoretical speculation into a subject disciplined by direct observation. In 1978 Penzias and Wilson received the Nobel Prize for Physics for their momentous discovery. [ 2 ] HISTORY "We live in an ocean of whispers left over from our eruptive creation, physicist George Gamow and his colleagues had said.

Nobody was listening." [ 3 ] By the middle of the 20th century cosmologists concerned with the creation of the universe had evolved two leading theories to explain their views. Some astronomers supported the steady-state theory of creation, which stated that the universe has always existed and will continue to survive without noticeable change. Others believed in the "Big Bang" theory of creation which taught that the universe is the glowing debris of a huge fireball that was created in a massive explosion about 16 billion years ago. No one knew for sure which theory was correct. At Holmdel, New Jersey, in 1964 Dr. Arno Penzias and Dr. Robert Wilson were experimenting with a supersensitive, 20-foot horn-shaped antenna originally built to detect radio waves bounced off Echo balloon satellites. To measure faint radio waves from the Telstar communications satellite, they had to eliminate all recognizable interference from their receiver. They removed the effects of radar and radio broadcasting, and suppressed interference from the heart in the receiver itself by cooling it with liquid helium to -269°C, only 4° above absolute zero--the temperature at which all motion in atoms and molecules stops.

[ 4 ] When Penzias and Wilson reduced their data they found a low, steady, mysterious noise that persisted in their receiver. This residual noise was 100 times more intense than they had expected, was evenly spread over the sky, and was present day and night. They were certain that the radiation they detected on a wavelength of 7.35 centimeters did not come from the Earth, the Sun, or our Galaxy. After thoroughly checking their equipment, the noise remained. Both men concluded that this noise was coming from outside our own galaxy--although they were not aware of any radio source that would account for it. At that same time, Robert H. Dicke, Jim Peebles, and David Wilkenson, astrophysicists at Princeton University, just 40 miles away, were preparing to search for microwave radiation in this region of the spectrum. Dicke and his colleagues reasoned that the "Big Bang" must have scattered not only the matter that condensed into galaxies but also must have released a tremendous blast of radiation. With the proper instrumentation, this radiation should be detectable.

When a friend told Penzias about a preprint paper he had seen by Jim Peebles on the possibility of finding radiation left over from a fireball that filled the universe at the beginning of its existence, Penzias and Wilson began to realize the significance of their discovery. The characteristics of the radiation detected by Penzias and Wilson fit exactly the radiation predicted by Robert H. Dicke and his colleagues at Princeton University. Penzias called Dicke at Princeton, who immediately sent him a copy of the still-unpublished Peebles paper. Penzias read the paper and called Dicke again and invited him to Bell Labs to look at the Horn Antenna and listen to the background noise. Dicke, Penzias, and Wilson visited the antenna and immediately recognized the significance of their discovery--they had stumbled on to the "embers" of creation predicted by their Princeton colleagues. To avoid potential conflict, they decided to publish their results jointly. Two notes were rushed to the Astrophysical Journal Letters. In the first, Dicke and his associates outlined the importance of cosmic background radiation as substantiation of the Big Bang Theory.

In a second note, jointly signed by Penzias and Wilson titled, "A Measurement of Excess Antenna Temperature at 4080 Megacycles per Second," they noted the existence of the residual background noise and attributed a possible explanation to that given by Dicke in his companion letter. Harvard physicist Edward Purcell read this announcement and concluded that "It just may be the most important thing anybody has ever seen." [ 5 ] Astronomer Robert Jastrow echoed this conclusion by stating that Penzias and Wilson ". . . made one of the greatest discoveries in 500 years of modern astronomy." [ 6 ] In 1978, Dr. Arno Penzias and Dr. Robert Wilson were awarded the Nobel Prize for Physics for their joint discovery. FOOTNOTES 1. The descriptive material for this section was taken from the following sources: J.S. Hey, The Evolution of Radio Astronomy (New York: Neale Watson Academic Publications, Inc., 1973), pp. 98-99. A.B. Crawford, D. C. Hogg, and L. E.

Hunt, "Project Echo: A Horn Antenna for Space Communication," Bell System Technical Journal (July 1961), pp. 1095-1099. 2. Marcus Chown, "A cosmic relic in three degrees," New Scientist, September 29, 1988, pp. 51-52. Richard Learner, Astronomy Through the Telescope (New York: Van Nostrand Reinhold Company, 1981), p. 154. 3. Timothy Ferris, The Red Limit: The Search for the Edge of the Universe, (New York: Quill Press, 1983), p. 141. 4. Herbert Friedman, The Amazing Universe (Washington, DC: National Geographic Society, 1975), p 166-167. 5. Ferris, op. cit., 151. 6. Robert Jastrow, God and the Astronomers (New York: W. W. Norton & Company, Inc., 1978), p. 20. BIBLIOGRAPHY Aaronson, Steve.

"The Light of Creation: An Interview with Arno A. Penzias and Robert W. Wilson." Bell Laboratories Record. January 1979, pp. 12-18. Abell, George O. Exploration of the Universe. 4th ed., Philadelphia: Saunders College Publishing, 1982. Asimov, Isaac. Asimov's Biographical Encyclopedia of Science and Technology. 2nd ed., New York: Doubleday & Company, Inc., 1982. Bernstein, Jeremy. Three Degree Above Zero: Bell Labs in the Information Age. New York: Charles Scribner's Sons, 1984. Chown, Marcus. "A cosmic relic in three degrees," New Scientist, September 29, 1988, pp. 51-55. Crawford, A.B. , D.C. Hogg and L.E. Hunt. "Project Echo: A Horn-Reflector Antenna for Space Communication," The Bell System Technical Journal, July 961, pp. 1095-1099. Disney, Michael. The Hidden Universe. New York: Macmillan Publishing Company, 1984.

Ferris, Timothy. The Red Limit: The Search for the Edge of the Universe. 2nd ed., New York: Quill Press, 1978. Friedman, Herbert. The Amazing Universe. Washington, DC: National Geographic Society, 1975. Hey, J.S. The Evolution of Radio Astronomy. New York: Neale Watson Academic Publications, Inc., 1973. Jastrow, Robert. God and the Astronomers. New York : W. W. Norton & Company, Inc., 1978. Kirby-Smith, H.T. U.S. Observatories: A Directory and Travel. Guide. New York: Van Nostrand Reinhold Company, 1976. Learner, Richard. Astronomy Through the Telescope. New York: Van Nostrand Reinhold Company, 1981. Penzias, A.A., and R. W. Wilson. "A Measurement of the Flux Density of CAS A At 4080 Mc/s," Astrophysical Journal Letters, May 1965, pp. 1149-1154.

PHOTOGRAPHS (click on the above photographs for a more detailed view) NEXT The Discovery of the Cosmic Microwave Background The Discovery of the Cosmic Microwave Background Sponsored by The Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, Inc. Aug 18 2014 Image Credit: Igor Zh/Shutterstock.com An accidental discovery by Robert Wilson and Arno Penzias in 1964 changed the entire landscape of cosmology and established the concept of a big bang as a keystone in our understanding of how the universe came into existence. Steady State vs Big Bang Throughout the 1940s and 1950s, cosmologists had been involved in a debate regarding the origin of the universe. By the start of the 1960s, the two most popular cosmological models in this scientific field were the Steady State theory and the Big Bang theory. The Steady State model, which was championed by the English astronomer Sir Fred Hoyle, postulated that the universe obeyed the perfect cosmological principle. This meant that the universe was both homogeneous and isotropic in space and time when observed on sufficiently large enough scales.

This theory also hypothesised that the universe had always existed and would continue to do so without much change. In stark contrast, the Big Bang theory suggested that the universe had been formed fractions of a second after a huge explosion which happened billions of years ago. The concept of the ‘primeval atom’, which was used as the basis of the big bang theory as we know it, was first proposed by the Belgian astronomer and physicist, Georges Lemaître. This concept was then advocated and developed into a fully formed theory, in part by the Russian cosmologist George Gamow. Image Credit: Designua/Shutterstock.com The Big Bang’s Smoking Gun In 1964 two American radio astronomers, Robert Wilson and Arno Penzias, were working at the Bell Labs in Holmdel, using the Horn Antenna to map signals across the Milky Way. The Holmdel Horn Antenna was a highly sensitive instrument originally built to detect faint radio waves, which had been deflected off of satellites. In order for the antenna to work properly, all “noisey” interference, such as radio waves, radar and heat, had to be completely eliminated.

However, after removing the obvious sources of interference, the researchers still noticed a faint, persistent and ever-present noise emanating from every direction. It was not coming from a planet, the sun, or anywhere else in the Milky Way. As a result, the Wilson and Penzias could only logically conclude that the noise was originating from outside of our galaxy. Meanwhile at nearby Princeton, the astrophysicists Jim Peebles, Robert Dicke and David Wilkinson were trying to detect microwave radiation. They predicted that the Big Bang explosion would have strewn both matter and radiation out across the newly formed universe and were ready to build an experiment to try test their hypothesis. The radiation detected by Wilson and Penzias perfectly matched with the predictions made by Peebles, Dicke and Wilkinson. The cosmic microwave background radiation was dubbed a signature of the Big Bang event or its “smoking gun”. A Bigger Bang The discovery of the cosmic microwave background gave Penzias and Wilson the Nobel Prize in Physics in 1978 and is regarded as a hallmark moment in modern physical cosmology, validating the efficacy of the Big Bang Theory.

Since its discovery, the cosmic microwave background has been a basic pillar of the cosmological model and continues to provide insights into the makeup of the universe. The observable universe, made up of stars, planets and galaxies, comprises of less than 5% of the universe's total mass. The universe is believed to be mostly comprised of dark energy, a mysterious force driving the expansion of our universe at an ever-increasing rate. The next largest component is dark matter, which is believed to account for a large amount of the invisible mass in the universe. Although dark energy and dark matter are still not fully understood, cosmic microwave background observations have become powerful tools for cosmologists to study the mysterious forces which are at work in the universe. References and Further Reading Cosmic Anniversary: 'Big Bang Echo' Discovered 50 Years Ago Today Cosmic Anniversary: 'Big Bang Echo' Discovered 50 Years Ago Today By Mike Wall, Senior Writer | May 20, 2014 07:08am ET MORE Two Cosmic Microwave Background anomalies hinted at by the Planck observatory's predecessor, NASA's WMAP, are confirmed in new high-precision data revealed on March 21, 2013.

In this image, the two anomalous regions have been enhanced with red and blue shading to make them more clearly visible. Credit: ESA and the Planck Collaboration Humanity's understanding of the universe took a giant leap forward 50 years ago today. On May 20, 1964, American radio astronomers Robert Wilson and Arno Penzias discovered the cosmic microwave background radiation (CMB), the ancient light that began saturating the universe 380,000 years after its creation. And they did so pretty much by accident. Bell Labs' Holmdale Horn Antenna in New Jersey picked up an odd buzzing sound that came from all parts of the sky at all times. The noise puzzled Wilson and Penzias, who did their best to eliminate all possible sources of interference, even removing some pigeons that were nesting in the antenna. [ CMB: Big Bang Relic Explained (Infographic) ] "When we first heard that inexplicable 'hum,' we didn’t understand its significance, and we never dreamed it would be connected to the origins of the universe ," Penzias said in a statement.

"It wasn’t until we exhausted every possible explanation for the sound's origin that we realized we had stumbled upon something big." And it was indeed big. Penzias and Wilson had spotted the CMB, the predicted thermal echo of the universe's explosive birth. The landmark find put the Big Bang theory on solid ground, suggesting that the cosmos did indeed grow from a tiny seed — a single point — about 13.8 billion years ago. The two radio astronomers won the 1978 Nobel Prize in physics for their work, sharing the award with Soviet scientist Pyotr Kapitsa. The Cosmic Microwave Background (CMB) radiation tells us the age and composition of the universe and raises new questions that must be answered. See how the Cosmic Microwave Background works and can be detected here . Credit: Karl Tate, SPACE.com Infographics Artist Ancient light The CMB is the oldest light in the universe , dating from the first epoch in which photons could travel freely. Shortly after the Big Bang, the cosmos was a seething-hot, opaque fog of plasma and energy; things changed about 380,000 years later, when temperatures dropped enough for electrically neutral atoms to form, and the universe became transparent.

The CMB is markedly uniform, lending support to the theory of cosmic inflation, which posits that the universe expanded much faster than the speed of light just a few tiny fractions of a second after the Big Bang. "Why the cosmic microwave background temperature is the same at different spots in the sky would be a mystery if it was not for inflation saying, well, our whole sky came from this tiny region," Charles Bennett of Johns Hopkins University in Baltimore told Space.com last year. Bennett is principal investigator of NASA's CMB-mapping Wilkinson Microwave Anisotropy Probe (WMAP), which launched in 2001 and stopped gathering data in 2010. But the CMB also contains tiny temperature variations, which signify areas of different densities. These density fluctuations were the seeds that eventually gave rise to stars, galaxies and all the other structure that we observe in the universe today, researchers say. Scientists have extracted a great deal of information from the CMB over the years. In March, for example, a team of astronomers announced that they had found evidence of primordial gravitational waves in the CMB — a discovery that, if confirmed, provides a long-sought "smoking gun" for the theory of cosmic inflation.

Such discoveries continue to impress Wilson. "It's amazing to me that people can dig something out that's a tenth of a part per million of the cosmic background, especially given a lot of foreground that might get in the way," he told Space.com in March. "And I guess my real thought is how much has come out of what can be seen in the cosmic background radiation," he added. "The real signature we saw was that it was absolutely constant, and now the tiny variations in it have turned out to hold a wealth of information." [ Cosmic Inflation and Gravitational Waves: Complete Coverage ] Celebrating the discovery Bell Labs is hosting a 50th anniversary celebration today at its Holmdale facility, which Penzias and Wilson — who are now 81 and 78 years old, respectively — will attend, as will Bell Labs president and CTO Marcus Weldon. During the event, Bell Labs — the research arm of Paris-based company Alcatel-Lucent — will also announce the Bell Labs Prize, a competition that gives scientists around the globe the chance to introduce to the world their ideas in the fields of information and communications technology.

The challenge offers a grand prize of $100,000; second prize is worth $50,000 and third $25,000. Winners may also get the chance to develop their ideas at Bell Labs, company representatives said. "I think it is fitting that today, as we honor and celebrate this incredible, Nobel Prize-winning achievement by Arno and Bob, we are launching a program intended to inspire world-changing discoveries and innovations by young researchers that may one day walk in their footsteps," Weldon said. "The Bell Labs Prize is intended to recognize innovators with the ability and vision to challenge the common assumptions, and find ways to revolutionize the way we live, work, communicate, collaborate and connect with each other and our digital world," he added. The deadline to enter the Bell Labs Prize is July 15. You can learn more about the competition here: Follow Mike Wall on Twitter @michaeldwall and Google+ . Follow us @Spacedotcom , Facebook or Google+ . Originally published on Space.com . Editor's Recommendations BBC - Universe - Cosmic microwave background radiation CMB (pictures, video, facts & news) Cosmic microwave background radiation discovered Scientists map the early Universe.

The astronomers Arno Penzias and Robert Wilson discovered the cosmic microwave background (CMB) radiation by chance in the mid-1960s while using the Holmdel Horn Antenna in New Jersey to map the sky. The CMB was later mapped with satellites, including the WMAP probe. About Cosmic microwave background radiation (CMB) The cosmic microwave background (CMB) is the thermal radiation left over from the time of recombination in Big Bang cosmology. In older literature, the CMB is also variously known as cosmic microwave background radiation (CMBR) or "relic radiation". The CMB is a cosmic background radiation that is fundamental to observational cosmology because it is the oldest light in the universe, dating to the epoch of recombination. With a traditional optical telescope, the space between stars and galaxies (the background) is completely dark. However, a sufficiently sensitive radio telescope shows a faint background glow, almost isotropic, that is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum.

The accidental discovery of the CMB in 1964 by American radio astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s, and earned the discoverers the 1978 Nobel Prize. The CMB is well explained as radiation left over from an early stage in the development of the universe, and its discovery is considered a landmark test of the Big Bang model of the universe. When the universe was young, before the formation of stars and planets, it was denser, much hotter, and filled with a uniform glow from a white-hot fog of hydrogen plasma. As the universe expanded, both the plasma and the radiation filling it grew cooler. When the universe cooled enough, protons and electrons combined to form neutral hydrogen atoms. These atoms could no longer absorb the thermal radiation, and so the universe became transparent instead of being an opaque fog.Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch, and the event shortly afterwards when photons started to travel freely through space rather than constantly being scattered by electrons and protons in plasma is referred to as photon decoupling.

The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time (and wavelength is inversely proportional to energy according to Planck's relation). This is the source of the alternative term relic radiation. The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling. Precise measurements of the CMB are critical to cosmology, since any proposed model of the universe must explain this radiation. The CMB has a thermal black body spectrum at a temperature of 7000272548000000000♠2.72548±0.00057 K. The spectral radiance dEν/dν peaks at 160.23 GHz, in the microwave range of frequencies.

(Alternatively, if spectral radiance is defined as dEλ/dλ, then the peak wavelength is 1.063 mm.) The glow is very nearly uniform in all directions, but the tiny residual variations show a very specific pattern, the same as that expected of a fairly uniformly distributed hot gas that has expanded to the current size of the universe. In particular, the spectral radiance at different angles of observation in the sky contains small anisotropies, or irregularities, which vary with the size of the region examined. They have been measured in detail, and match what would be expected if small thermal variations, generated by quantum fluctuations of matter in a very tiny space, had expanded to the size of the observable universe we see today. This is a very active field of study, with scientists seeking both better data (for example, the Planck spacecraft) and better interpretations of the initial conditions of expansion. Although many different processes might produce the general form of a black body spectrum, no model other than the Big Bang has yet explained the fluctuations. As a result, most cosmologists consider the Big Bang model of the universe to be the best explanation for the CMB.

The high degree of uniformity throughout the observable universe and its faint but measured anisotropy lend strong support for the Big Bang model in general and the ΛCDM ("Lambda Cold Dark Matter") model in particular. Moreover, the fluctuations are coherent on angular scales that are larger than the apparent cosmological horizon at recombination. Either such coherence is acausally fine-tuned, or cosmic inflation occurred. This Month in Physics History This Month in Physics History More June 1963: Discovery of the Cosmic Microwave Background Sometimes the most stunning scientific discoveries are the least expected, and occur more by serendipity than by intent. Take the case of Bell Labs physicists Arno Penzias and Robert Wilson, who set out to map radio signals from the Milky Way and wound up being the first to measure the cosmic background radiation (CMB). Their momentous discovery made it possible to obtain information about cosmic processes that took place about 16 million years ago, and forever changed the science of cosmology, transforming it from a specialty of a select few astronomers to a "respectable" branch of physics almost overnight. In the 1950s there were essentially two theories about the origin of the universe.

One was the Steady State Theory, which held that the universe was homogenous in space and time and would remain so forever . The more controversial theory sought to incorporate Edwin Hubble's discovery in 1929 that galaxies are moving away from one another at remarkable speeds. A handful of physicists led by George Gamow argued that the separation between galaxies must have been smaller in the past, which meant that at some point the universe had once been infinitely dense. Everything in the universe had emerged from this incredibly dense and hot state in a cataclysmic explosion called "the Big Bang." Bell Labs had built a giant, 20-foot horn-shaped antenna in Holmdel, NJ in 1960 as part of a very early satellite transmission system called Echo, but the launch of the Teslar satellite a few years later made the Echo system obsolete for its intended commercial application. Penzias and Wilson seized the opportunity to use the antenna as a radio telescope to amplify and measure radio signals from the spaces between galaxies. To do so, they had to eliminate all recognizable interference from their receiver, removing the effects of radar and radio broadcasting and suppressing interference from the heart of the receiver itself by cooling it with liquid helium.

However, when Penzias and Wilson reduced their data, they found an annoying background "noise", like static in a radio, that interfered with their observations. The noise was a uniform signal in the microwave range (with a wavelength of 7.35 centimeters), and seemed to come from all directions. Penzias and Wilson checked everything they could think of to rule out the source of the excess radiation. They pointed the antenna at New York City and found it wasn't due to urban interference. Nor was it radiation from our galaxy or extraterrestrial radio sources. Finally, they decided the problem might be due to the droppings from pigeons roosting in the horn-shaped antenna, contrived a pigeon trap to oust the birds, and spent hours removing pigeon dung from the contraption. [Ivan Kaminow, a colleague of Penzias during the latter's early days at Bell Labs, once joked that Penzias and Wilson "looked for dung but found gold, which is just opposite of the experience of most of us."] Yet still the background radiation remained. So Penzias and Wilson began looking for theoretical explanations.

Around the same time, Princeton University physicist Robert Dicke theorized that if the universe was created according to the Big Bang theory, a low-level background radiation at around 3 degrees Kelvin would exist throughout the universe. Dicke had begun looking for evidence to support his theory when Penzias and Wilson got in touch with his laboratory. He visited Bell Labs and confirmed that the mysterious radio signal was indeed the cosmic background radiation — proof of the Big Bang. Dicke shared his theoretical work with the Bell Labs researchers, even as he resignedly admitted to his Princeton colleagues, "We've been scooped." The two groups published their results at the same time in Astrophysical Journal Letters. Penzias and Wilson received the Nobel prize in physics in 1978 for their serendipitous discovery of the CMB. More than three decades later, NASA sent the Cosmic Microwave Background Explorer (COBE) satellite into orbit to investigate the CMB in great detail, producing the first detailed map analyzing the small irregularities, or "ripples", in the microwave background. The giant radio antenna at Holmdel was designated a National Historic Landmark in 1990. Even the lowly pigeon trap has found its way into posterity.

It is now one of the key artifacts on permanent display in Washington, DC, part of a new exhibit at the Smithsonian Institute's National Air & Space Museum that debuted in September 2001, entitled, "Exploring the Universe." And Penzias and Wilson went down in scientific history for a momentous discovery that opened a window into the early universe, enabling astronomers and physicists to see the initial conditions from which the beauty of the present-day cosmos emerged. ©1995 - 2017, AMERICAN PHYSICAL SOCIETY APS encourages the redistribution of the materials included in this newspaper provided that attribution to the source is noted and the materials are not truncated or changed. Editor: Alan Chodos

Question: What important discovery was made in 1964 by radio astronomers Arno Penzias and Robert Wilson?
Answer: Cosmic microwave background radiation