7/11/2023 0 Comments Cosmic background![]() Dicke shared his theoretical work with the Bell Labs researchers, even as he resignedly admitted to his Princeton colleagues, "We've been scooped." He visited Bell Labs and confirmed that the mysterious radio signal was indeed the cosmic background radiation - proof of the Big Bang. Dicke had begun looking for evidence to support his theory when Penzias and Wilson got in touch with his laboratory. 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. So Penzias and Wilson began looking for theoretical explanations. Yet still the background radiation remained. Nor was it radiation from our galaxy or extraterrestrial radio sources.įinally, 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. ![]() They pointed the antenna at New York City and found it wasn't due to urban interference. Penzias and Wilson checked everything they could think of to rule out the source of the excess radiation. The noise was a uniform signal in the microwave range (with a wavelength of 7.35 centimeters), and seemed to come from all directions. However, when Penzias and Wilson reduced their data, they found an annoying background "noise", like static in a radio, that interfered with their observations. 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. 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. Everything in the universe had emerged from this incredibly dense and hot state in a cataclysmic explosion called "the Big Bang."īell 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. ![]() 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. The more controversial theory sought to incorporate Edwin Hubble's discovery in 1929 that galaxies are moving away from one another at remarkable speeds. One was the Steady State Theory, which held that the universe was homogenous in space and time and would remain so forever. In the 1950s there were essentially two theories about the origin of the universe. Their momentous discovery made it possible to obtain information about cosmic processes that took place about 14 billion 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. 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). ![]() Sometimes the most stunning scientific discoveries are the least expected, and occur more by serendipity than by intent. June 1963: Discovery of the Cosmic Microwave Background
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