horn antenna

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The test route linked New York with Boston, via eight microwave towers, some built from concrete blocks and others from steel girders, most located on hillsides (or in some cases on tall urban buildings), topped by special horn-shaped antennas, vaguely resembling megaphones, which had been invented at Bell Labs largely under the direction of Harald Friis, the head of Bell Labs’ Holmdel, New Jersey, research office.22 Usually, two horn-shaped antennas on the towers would receive calls; a repeater apparatus inside the tower would amplify them; and then two other horn-shaped antennas, facing the opposite way, would instantly relay them to the next tower in the phone link. The height of these towers was crucial: Transmissions by microwaves traveled in straight lines and required a clear line of sight.

For about $230,000, Jakes’s Echo crew purchased a huge dish antenna, sixty feet in diameter, that would transmit signals to the orbiting satellite—signals that the balloon would reflect to a ground site being built in tandem by the engineers at the Jet Propulsion Laboratory in Goldstone, California, just south of Death Valley. The Echo team, meanwhile, had also designed and requisitioned an immense horn antenna (the cost was about $128,000) resembling a kind of huge empty tobacco pipe, which would receive signals sent from the Jet Propulsion station in California as they bounced off the orbiting satellite.20 It was, in essence, a simple two-way conversation, but one made possible through an immensely complex electronic infrastructure on each edge of the continent. The horn antenna on Crawford Hill would be “steerable.” That is to say, it would be mounted on a circular track so that it could swivel according to the predicted path of the satellite. Near the base of the horn antenna, the Echo team would install the supercooled maser that would amplify the faint signals. It was true, to a large extent, that the satellite project was about technology.

The traveling wave tube, now moving out of its development stage, could likewise be valuable, since it could amplify a multitude of telephone or television channels simultaneously. Much of the challenge in creating satellite communications lay not in the satellites themselves but in building an adequate system for transmitting and receiving signals from the ground, as well as a system for tracking the satellite as it moved across the sky. In this regard, a third existing technology appeared vital. It was the horn antenna, which had been designed by Bell Labs’ Harald Friis at the rural Holmdel lab in southern New Jersey. Horn antennas were already a crucial component in microwave towers across the country: They allowed for the reception of signals in a focused manner that greatly reduced surrounding noise and interference. There was no reason to think they couldn’t be adapted for satellite communications. By late 1956, about two years after Pierce’s talk at Princeton, some other necessary elements for his idea had sprung into existence.

pages: 492 words: 149,259

Big Bang by Simon Singh

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Albert Einstein, Albert Michelson, All science is either physics or stamp collecting, Andrew Wiles, anthropic principle, Arthur Eddington, Astronomia nova, Brownian motion, carbon-based life, Cepheid variable, Chance favours the prepared mind, Commentariolus, Copley Medal, cosmic abundance, cosmic microwave background, cosmological constant, cosmological principle, dark matter, Dava Sobel, Defenestration of Prague, discovery of penicillin, Dmitri Mendeleev, Edmond Halley, Edward Charles Pickering, Eratosthenes, Ernest Rutherford, Erwin Freundlich, Fellow of the Royal Society, fudge factor, Hans Lippershey, Harlow Shapley and Heber Curtis, Harvard Computers: women astronomers, Henri Poincaré, horn antenna, if you see hoof prints, think horses—not zebras, Index librorum prohibitorum, invention of the telescope, Isaac Newton, John von Neumann, Karl Jansky, Louis Daguerre, Louis Pasteur, luminiferous ether, Magellanic Cloud, Murray Gell-Mann, music of the spheres, Olbers’ paradox, On the Revolutions of the Heavenly Spheres, Paul Erdős, retrograde motion, Richard Feynman, Richard Feynman, scientific mainstream, Simon Singh, Solar eclipse in 1919, Stephen Hawking, the scientific method, Thomas Kuhn: the structure of scientific revolutions, unbiased observer, V2 rocket, Wilhelm Olbers, William of Occam

Wilson was partly attracted to Bell Labs because of its 6-metre horn radio antenna sited at nearby Crawford Hill, shown in Figure 96. This was originally designed to detect signals from the innovative Echo balloon satellite, which had been launched in 1960. Echo had been squeezed into a 66-centimetre sphere for launching into orbit, but once in space it was inflated into a giant silver globe, 30 metres in diameter, which was capable of passively bouncing signals between an Earth-based transmitter and receiver. However, government intervention in this sector of the communications industry persuaded AT&T to withdraw from the Echo project for economic reasons, leaving the horn antenna free to be transformed into a radio telescope. The horn antenna was doubly suited for radio astronomy: it was largely shielded from local radio interference, and its size meant that it could locate the source of celestial radio signals with good accuracy.

Indeed, most radio astronomers would have ignored the problem and embarked on their survey. Penzias and Wilson, however, were determined to conduct the most sensitive survey possible, so they immediately set about trying to locate the source of the noise and, if possible, reduce it or remove it completely. Figure 96 Robert Wilson (left) and Arno Penzias posing in front of Bell Laboratories’ horn antenna at Crawford Hill, New Jersey. This radio telescope is essentially a giant glorified radio receiver. Its aperture is 6 metres square and the monitoring equipment is housed in a hut at the apex of the cone. Noise sources can be broadly split into two types. First, there is extraneous noise, which is caused by some entity beyond the radio telescope, such as a major city on the horizon or some nearby electrical equipment.

Exactly the same problem arises with your domestic radio: even if the broadcaster has a strong signal, it can be degraded by noise generated by your radio’s amplifier, speaker or wiring. Penzias and Wilson checked every single element of their radio telescope, looking for dodgy contacts, sloppy wiring, faulty electronics, misalignments in the receiver, and so on. Even joints that already seemed to be okay were patched up with aluminium tape just to be sure. At one point, attention focused on a pair of pigeons that had nested inside the horn antenna. Penzias and Wilson thought that the ‘white dielectric material’ deposited by the pigeons and smeared on the horn might be the cause of the noise. So they trapped the birds, placed them in a mail van and had them released 50 kilometres away at the Bell Labs site in Whippanny, New Jersey. They scrubbed the antenna until it was bright and shiny, but alas the pigeons obeyed their homing instinct, flew back to the telescope’s horn and started depositing white dielectric material all over again.


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Crimson footprints separate them from the corpse of their blood-spattered baby. All 18 nutshell dioramas are displayed at the Maryland Medical Examiner’s Office. The gory tableaus are still studied by detectives in training. 900 West Baltimore Street, Baltimore. 39.289109 76.632637 Tiny forensic dollhouses train detectives to solve crimes. NEW JERSEY Holmdel Horn Antenna HOLMDEL In 1965, Arno Penzias and Robert Wilson accidentally discovered one of the greatest secrets of the universe. The radio astronomers were using the Bell Labs horn antenna to scan for radio waves being bounced off NASA communications satellites. To Penzias’s and Wilson’s annoyance, an ever-present low hum interfered with their data collection. They checked their equipment, shooed away some pigeons that had been nesting in the antenna, and listened again. Still the hum persisted.

Still the hum persisted. The noise was not coming from the antenna, or anywhere in New Jersey, or anywhere on earth. It came from the universe itself. Penzias and Wilson had just stumbled upon cosmic microwave background. Penzias’s and Wilson’s discovery provided the first observational evidence that the universe began with a Big Bang. The discovery earned them a Nobel Prize in Physics. The decommissioned horn antenna they used for their explosive discovery is now a National Historic Landmark. Holmdel Road and Longview Drive, Holmdel. 40.390760 74.184652 Once the pigeons were shooed away, scientists were able to detect the faint echoes of the Big Bang. Northlandz FLEMINGTON Over 8 miles (13 km) of miniature train tracks run through this building, making it the largest model train layout in the world.

Peters, 20 Ruins of the MV Plassey, 14 Sacred City of Caral-Supe, 405 Santa Claus, 297 Sewell, 397 Spreepark, 45 Steetley Magnesite, 5 Steinart Hall, 372 Suakin, 194 Sunken City, 281 Umatilla Chemical Depot, 292 Uranium City, 264 Val-Jalbert Ghost Town, 274 Varosha Beach Resort, 51 White City Ruins, 281 see also Lost Cities and Towns SCIENCE MUSEUMS AND EXPERIMENTS Alchemy Museum, 78 American Computer Museum, 313 Birthplace of Tesla Museum and Memorial Center, 77 Boomeria, 287 California Science Center, 281 Centennial Bulb, 286 Dymaxion Chronofile, 279 Edison’s Last Breath, 328 Electronic Museum, 80 Ether Dome, 372 Gottfried Knoche’s Mummy Lab, 411 Griffith Observatory’s Tesla Coil, 281 Hessdalen AMS, 107 Holmdel Horn Antenna, 356 IceCube Research Station, 447 Instituto Butantan, 394 Integratron, 279 Mapimí Silent Zone, 417 Marconi National Historic Site, 268 Mark I, 372 Moore Lab of Zoology, 281 Musée des Arts et Métiers, 37 Nikola Tesla Museum, 94 Phone Booth on a Roof, 322 Pitch Drop Experiment, 232 Quiet Zone, 366 Reed College Research Reactor, 291 Sound Garden, 294 Wilhelm Reich Museum, 370 World’s Quietest Room, 329 SELF-BUILT CASTLES Bishop Castle, 298 Cano’s Castle, 299 Château Laroche, 333 Coral Castle, 299 Don Justo’s Self-Built Cathedral, 68 Moussa Castle, 120 Mystery Castle, 299 Palais Idéal, 38 Rubel Castle, 299 Solomon’s Castle, 299 Taródi Vár Castle, 80 Tower of Eben-Ezer, 30 STRANGE ARCHITECTURE Abita Mystery House, 346 Abuja Airplane House, 203 Amargosa Opera House and Hotel, 284–285 Arcosanti, 297 Arctic architecture, 262–263 Ateneo Grand Splendid, 383 Atomium, 30 Aurora Ice Museum, 377 Binoculars Building, 281 Blackfriars Playhouse, 351 Bob Baker Marionette Theater, 281 Bok Tower Gardens, 342 Boswell Embalming Bottle House, 260 Boulders of Monsanto, 66 Bridge to Nowhere, 243 Britannia Panopticon Music Hall, 20 Bruno Weber Skulpturenpark, 72 Carriolu Miniature Village, 40 Chan, 405 Chand Baori Stepwell, 132 Cigar Band House, 65 Clown Motel, 300 Concrete Parthenon, 351 Dans le Noir, 37 Discovery Hut, 447 Drottningholms Palace Theater, 110 Dunmore Pineapple, 20 Free Spirit Spheres, 259 Gbadolite, 207 Gold Pyramid House, 322 Greatstone Sound Mirrors, 8 Hobbiton, 240 House of Balls, 329 House of Evgeny Smolik, 92 House of Plastic Bottles, 386 House on the Rock, 334 Igloolik Research Station, 263 Infinite Corridor (MIThenge), 372 Karl Junker House, 45 Kowloon Walled City Park, 151 Kremsmunster Observatory, 25 Kruševo Makedonium, 83 Kyaiktiyo Balancing Pagoda, 177 Loretto Chapel Stairs, 305 Lumilinna Snow Castle, 102 Magic Mountain Hotel, 397 Maison Picassiette, 33 McElroy Octagon House, 287 Mini Taj Mahal, 128 Minimundus, 25 Mistake House, 321 La Mona, 418 Moonhole, 442 Mudhif Houses, 116 Nakasuk School, 263 Naucalpan, 417 New Lucky Restaurant, 132 Newgrange Mound, 15 Nördlingen, 41 Painted Village, 85 Palacio Barolo, 385 Paper House, 373 Passetto di Borgo, 58 Ponte City Apartments, 216 Pope Leo’s Bathroom, 57 President’s Room, 118 Quinta da Regaliera, 67 Radio City Music Hall’s Secret Apartment, 359 Rundetårn, 100 Ryugyong Hotel, 164–165 Salar de Uyuni, 388 Sam Kee Building, 258 Santa’s Workshop, 104 727 Fuselage Home, 421 Shackleton’s Hut, 449 Skellig Michael, 15 Solar Power Towers, 70 Solomon’s Castle, 299 Stiltsville, 340 Swallow’s Nest, 98 Tash Rabat, 137 Teatro Amazonas, 395 Tower of Eben-Ezer, 30 Trick Fountains of Hellbrunn Palace, 28 Upside-Down House, 83 Venetian Palace Diorama, 372 Watts Tower, 281 Wilson’s Stone Igloo, 447 Winchester Mystery House, 279 Wishbones of McSorley’s Old Ale House, 359 Wuppertal Suspension Railway, 46 see also Pyramids; Self-built Castles, Towers, and Homes STRANGE FLORA AND FAUNA Abu Dhabi Falcon Hospital, 123 Adak National Forest, 378 African Dream Root, 393 Archie the Giant Squid, 12–13 blue-ringed octopus, 228 box jellyfish, 228 Chocolate Hills, 178 coastal taipan, 229 Cochrane Polar Bear Habitat, 273 Colossal Squid, 244 Dzanga Bai, 206 eye worm, 154 Firefly Squid of Toyama Bay, 156–157 Franklin Park Zoo Bear Pens, 372 Grant Museum of Zoology, 10 Guinea worms, 154 gympie gympie, 229 hemlock, 4 Huachuma, 392 Huberta the Hippo, 216 Iboga, 393 Impaled Stork, 47 Jellyfish Lake, 248 Jigokudani Park, 160 Knight’s Spider Web Farm, 375 lake monsters, 368–369 Litchfield Termite Mounds, 234 loa loa, 154 Maasai Ostrich Farm, 210 Manú National Park, 405 Monarch Butterfly Biosphere Reserve, 417 Musk Ox Farm, 377 Narcisse Snake Orgy, 261 Pablo Escobar’s Hippos, 399 Pangolin Rehabilitation Center, 169 Pitcher Plants of Kinabalu, 176 Rat King, 38 Sacred Crocodile Pond, 199 Salvia divinorum, 392 Seneca White Deer, 360 Skunk Ape Research Headquarters, 341 Sloth Sanctuary, 422 Socotra Island, 124 stonefish, 228 Swimming Pigs, 426 Sydney funnel-web spider, 229 Synchronized Fireflies of Kampung Kuantan, 176 tapeworms, 154 Thousand-Year Rose, 44 Three-Century Labyrinth, 65 Tortoises of Aldabra, 222 Ueno Zoo Escaped Animal Drill, 155 University of Florida Bat Houses, 340 Vallée de Mai, 221 Victoria Amazonica, 395 Wallabies of Lambay, 17 Wichita Mountains Buffalo Herd, 317 Zoological Museum at Vietnam National University, 184 Zoological Museum (Bologna), 52 Zoological Museum (Cluj-Napoca), 86 see also Trees STRANGE TOWNS AND CITIES Auroville, 132 Castellfollit de la Roca, 70 Ciudad Mitad del Mundo, 402 Colonia Tovar, 410 Darra Adam Khel, 140 Dwarf Empire, 146 Fordlândia, 395 Fucking, Austria, 25 Ganvie, 196 Garbage City, 188 Giethoorn, 64 Hallstatt, 150 Kampong Ayer, 168 Kijong-dong, 163 Kingdom of Women, 146 Nova Cidade de Kilamba, 213 Oyotunji African Village, 350 PhinDeli Town, 318 Setenil de las Bodegas, 70 Villa Baviera, 397 Vulcan, 257 Walled City of Shibam, 124 Whittier, Alaska, 377 SUPERNATURAL Badlands Guardian, 258 Betty and Barney Hill Archive, 374 Cassadaga, 342 Child-Eater of Bern, 73 Devil’s Footprint, 41 Devils’ Museum, 83 Devil’s Tramping Ground, 348 Fairy Circles, 215 Gurdon Light, 339 Hook & Ladder 8, 359 International Cryptozoology Museum, 367 Lily Dale Assembly, 360 Marree Man, 234 Mary King’s Close, 20 Mumtaz Begum, 140 Musée de la Magic, 37 Museo de las Brujas, 70 Museum of Witchcraft and Magic, 7 Oregon Vortex, 289 Robert the Doll, 342 TAXIDERMY Agriculture Museum of Budapest, 81 August von Spiess Museum of Hunting, 87 Deyrolle Taxidermy, 34 Grip the Raven, 364 TEMPLES, CHURCHES, AND MONASTERIES Angelus Temple, 281 Astronomical Clock of Besançon Cathedral, 33 Beer Bottle Temple, 183 Cao Dai Holy See, 184 Cathedral of Junk, 308 Cathedral of Our Lady of the Angels, 281 Chained Books of Hereford Cathedral, 5 Chapel Oak, 33 Chapel of the Snows, 447 Chicago Temple, 320 Church of St.

pages: 279 words: 75,527

Collider by Paul Halpern

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Rather than starting again, He crafted an alternative solution: “And God said: ‘Let there be Hoyle’ . . . and told him to make heavy elements in any way he pleased.”3 Despite its failure to explain synthesis of higher elements, the Big Bang theory has proven a monumentally successful description of the genesis of the universe. A critical confirmation of the theory came in 1965 when Arno Penzias and Robert W. Wilson pointed a horn antenna into space and discovered a constant radio hiss in all directions with a temperature of around three degrees above absolute zero (the lower limit of temperature). After learning of these results, Princeton physicist Robert Dicke demonstrated that its distribution and temperature were consistent with expectations for a hot early universe expanding and cooling down over time. In the 1990s and 2000s, designated satellites, called the COBE (Cosmic Background Explorer) and the WMAP (Wilkinson Microwave Anisotropy Probe), mapped out the fine details of the cosmic background radiation and demonstrated that its temperature profile, though largely uniform, was pocked with slightly hotter and colder spots—signs that the early universe harbored embryonic structures that would grow up into stars, galaxies, and other astronomical formations.

pages: 420 words: 119,928


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If the cosmic microwave background is fluctuating this much, we should be able to see it with our own eyes.” “What are you talking about? The wavelength of the cosmic microwave background is seven centimeters. That’s five orders of magnitude longer than the wavelength of visible light. How can we possibly see it?” “Using 3K glasses.” “Three-K glasses?” “It’s a sort of science toy we made for the Capital Planetarium. With our current level of technology, we could take the six-meter horn antenna used by Penzias and Wilson almost half a century ago to discover the cosmic microwave background and miniaturize it to the size of a pair of glasses. Then we added a converter in the glasses to compress the detected radiation by five orders of magnitude so that seven-centimeter waves are turned into visible red light. This way, visitors can put on the glasses at night and observe the cosmic microwave background on their own.

pages: 412 words: 122,952

Day We Found the Universe by Marcia Bartusiak

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Albert Einstein, Albert Michelson, Arthur Eddington, California gold rush, Cepheid variable, Copley Medal, cosmic microwave background, cosmological constant, Edmond Halley, Edward Charles Pickering, Fellow of the Royal Society, fudge factor, Harlow Shapley and Heber Curtis, Harvard Computers: women astronomers, horn antenna, invention of the telescope, Isaac Newton, Louis Pasteur, Magellanic Cloud, Occam's razor, Pluto: dwarf planet, Solar eclipse in 1919, William of Occam

The Royal Astronomical Society presented its highest award, the Gold Medal, to him in 1933, with its president, Frederick Stratton, amusingly announcing that “if cosmogonists to-day have to deal with a Universe that is expanding in fact as well as in fancy, at a rate which offers them special difficulties, a great part of the initial blame must be borne by our medallist.” In many ways, Slipher's accomplishment resembled that of Arno Penzias and Robert Wilson several decades later. In 1964 the two Bell Laboratory researchers were calibrating a massive horn-shaped antenna in New Jersey in preparation for some radio astronomy observations and registered an unexpected cosmic radio noise wherever they looked on the sky, spending months trying to discover its source. Just as Slipher revealed a remarkable phenomenon that took others time to fully interpret, so too did Penzias and Wilson need fellow astronomers to tell them what they had found, that they had been listening to the faint reverberation of the Big Bang all along.