History of Radio Telescopes - Essay Example

Running head: History of Radio Telescopes Student’s Name Institution Course Professor Date Introduction Over the last few decades, research done on radio astronomy shows that it has progressed and exploded into something that was never thought of despite of its slightly relaxed early stages. In fact, these new development in the field of astronomy have completely changed the way the universe is understood. Now, with fast improvement in technology, the universe is yet to be discovered in greater ways. As a matter of fact, these few coming decades are really going to be very interesting especially to the astronomers and the scientists. Development of single dish radio telescopes The History Of telescopes dates back to over 100 years ago. Born In 1905, Karl Jansky while working in a telephone company called Bell Laboratories in 1931, he built a radio antenna to find out why there was too much static on long distance telephone calls. The antenna was an array of dipoles and reflectors that had been designed to receive short wave radio signals at a frequency of 20.5MHz. It was erected on a turntable that gave it an ability to rotate in any direction hence the name Jansky’s merry-go-round. It had a diameter of approximately 100 feet (30 meters) and stood 20 feet (6 meters) tall. By rotating the antenna using four ford model-T tire, the exact direction of the receiver interfering radio source (static) could be identified. A small shed on the side of the antenna had an analog pen-and –paper recording system (Robertson, 1992) It was after recording signals from all directions for several months that Jansky finally categorized them into three forms of static nearby thunderstorms, distant thunderstorms and faint steady hiss of unknown origin. Jansky eventually discovered that the “faint hiss “was actually repeated on an intervals of 23 hours and 56 minutes. This period is the length of an astrominical sidereal day; that is the time it takes any stationery object located on the celestial sphere to return to the same location in the sky. Jansky therefore suspected that the hiss originated well beyond the Earth’s atmosphere, and by making comparison on his observations with optical astronomical maps, Jansky made a conclusion that the radiation from the Milky Way Galaxy was strongest in the direction of the centre of the galaxy in the constellation of the Sagittarius. Jansky wrote a report after his research which Grote Reber used to constructed his radio telescope (Sullivain, 2005). An amateur radio operator, Grote Reber became one of the founders of what was to become known as radio astronomy after he built the first parabolic ”dish “ radio telescope that measured (9 meters in diameter in his backyard in Illinois in 1937.He played a key role in repeating Karl Guthe Jansky’s project, but some how worked at higher frequencies, and he proceeded to conduct the first sky survey at very high radio frequencies ( Sullivain, 2005). Since then, radio telescopes have witnessed one of the first raising advancements. The examples below show very clearly how this field has been growing over the last few decades. The Lovell Telescope with 250 foot in Jodrell bank, England, was finished in 1957 and it became the first large steerable dish and it was popular for detecting sputnik. The length of the central tower that provided support to the feed at the prime focus was only about 30% of the reflector diameter. The parkes Telescope was constructed almost the same time as the Green Bank foot telescope, but it has a fabulous alt-az shape and is still in use, with multibeam receivers making HI and pulsar surveys of the southern sky, a very simple and less expensive was build immediately the 140 telescope in Green Bank underwent construction delay. It was a mobile telescope able to move in elevation along the southern line but in azimuth. It could observe sources over a wide variety of declinations, but only in a very short distance. The prime-focus feeds could shift slightly in the east west direction to track a source for some minutes while they remained within the focal ellipsoid. The surface of the 300-foot telescope was an open mesh that was made up of square holes of almost 6mm on a side; this was to reduce both the weight, as well as, the wind loading (Christiansen, 1987). Arecibo radio telescope situated in Arecibo Puerto RICO is the biggest filled-aperture telescope on the globe; its 10001ft dish is properly secured in the ground. The antenna beam is steerable (by means of a moving receiver) within about 20 degrees of the zenith. It is also the world’s largest planetary radar (Robertson, 1992). Advantages of interferometer 1 With the use interferometer, radio astronomers are able to achieve high angular resolution. The resolving power of this device is set by distance between its components, rather than its components 2 Interferometer is basically sensitive to small isolated sources rather than extended sources and background radiation. Plus, it is also somewhat insensitive to disturbance 3 An interferometer which comes with horizontal baseline is not actually affected by the plane-parallel component of atmospheric refraction that in many cases would delay signals reaching the two telescopes at the same time. 4 Interferometer has the ability to determine the positions of compact radio sources with accuracy Major discoveries that was possible after detection of radio waves from waves from space and how they changed understanding of the universe Quite a number of findings on radio astronomy field have been made several years after the discovery of radio waves. These discoveries have in many ways changed the way people have viewed the universe for years. Discussed below are seen discoveries that have changed and revolutionized the way people used to think about the universe. Radio telescopes, for sure, have made the universe to be understood much better (Robertson, 1992 pg. 87). One of the discoveries was by Harod Ewen, at Havard. This was actually the distinct occurrence signal produced by a massive quantities of atoms specifically hydrogen atoms; this hydrogen atoms that covered the entire space amid the stars. This discovery was totally distinct from extra-terrestrial signals that Reber and Jansky observed. The kind emissions generated by the deceleration or acceleration of charged electrons were wideband. (Sullivain, 2005) The cause of bulky emission of radiation has been seen to thermal sizzling substances or in other cases because of magnetic field motions that have circular shapes. At one thousand four hundred and twenty one Megahertz which is a wavelength of twenty one centimeters, a distinct occurrence radiation generated by hydrogen atoms happens as a result of an electron existing inside the atom swiftly changes spin axis’ direction. Basing on theoretical grounds, Hedrick van De Hulst, a Dutch astronomer predicted the presence of such kind of radiation in the year 1944. In the year 1951, Edwen’s discovered similar emission. This finding was in fact put into use in planning the organization of the Milky Way, our home galaxy. The southern part of the sky, on a cloudless dark night can be seen, this is definitely an indication of Milky-Way being a planar; also it could be a compacted structure such as saucer. Finding and elucidation of dissimilar radiation generated by sun was the second finding. Every fresh finding of the creation appears to be violent, multifaceted, and turbulent and not as it was previously thought. Paul Wild, radio physicist from Australia led a team that carried out the organization and physical examination of cosmological radio bursts; their discoveries meant a lot to the science of astrophysics and in fact it shown the atmospheric convolutions of the sun (Smith, 2013). It helped to understand when the solar surface temperature was 6000 Kelvin; the atmosphere’s outer part temperature was one million. In Carnegie foundation, Washington, Bernard Burk and Kenneth Frankline accidentally discovered the third finding; they found out in 1955 that there was noise originating from the planet Jupiter, something that no one expected. Over the years, this responsiveness has continued in a more thorough examination and exploration of the solar structure or system by space craft. In 1955 the 1st communication between the moon and the Jupiter magnetic field occurred at around twenty Mega Hertz which generated the chorus or repetition of the radio waves according to Smith (2013). The fourth discovery that played a key role when it came to the study of the universe is the quasi-stellar objects discovery. The original finding was made between the year 1961 and the year 1963. Cambridge University carried out a radio sky survey investigation that showed it as a radio source. This was a two hundred and seventy three object revealed in this survey, thus bearing the name 3c273 (Robertson, 1992 pg. 234). Radio telescopes, at this point, had no influential spatial and determining power. It therefore became very challenging to conclude that radio object might actually be found and examined using optical Hazard. Cyril Hazard, however, became successful when he decided to use CSIRO radio telescope, his success came as a result of lunar oscillations series to accurately determine the position for 3c273( the moon actually obscured the source) . Maartin Scmdt, a Palomar in his early years as an observatory stargazer was in a position to scrutinize 273 thoroughly. The first analysis showed it to resemble a star, but the other conclusions was against it; the speed regulation emanating from the spectral lines of Doppler shift appeared to specify that it laid two thousand million light years away. With such a distance, the MC273 power output is 10 IO watts both with the smallest size; this is a clear indication of gigantic energy usage. This is the same as using the entire power from the sun every month. In 1983, at siding spring, Australian observers made some discoveries using the Australian telescope and the Parkes radio telescope (Robertson, 1992). It was found out that a quasar 2000-3300 was predicted to be about 20,000,000,000 light years. Thus, this object is the only object in the entire universe which is moving away so fast; its velocity is at 92 % of light. The 5th vital happening is one that is believed to be the ultimate finding that any astrophysicist has yet to provide to the human race. This will ever be the finding of the massive assortment of the molecules which are all over the intercellular space. The way that hydrogen atoms were discovered is the same way that these molecules dispersed all over the intercellular space were discovered. This was by distinct but dissimilar shadowy occurrences they emit as they go through some change. It has been seen that all the molecules that have been discovered have different spectral signatures; thus these signatures can be used to identify them. In the year 1963, hydroxyl radical (OH) was the 1st intercellular molecule to be discovered and from that day incredible varieties of organic as well as inorganic molecules have been found to exist (Robertson, 1992 pg. 323 and 329). Monish University in Australia produced a very active team who carried out the entire exploration. The molecules that they found comprise of hydrogen cyanide, carbon monoxide and hydrogen sulphide. Research shows that a solitary frequency radioactivity produced by hydrogen atoms take place at around one thousand four hundred and twenty one Megahertz which is a wavelength of about twenty one centimeters; at this point the electron existing inside the atom has been seen to hastily flip the course of its ‘spin axis’. In the year 1944, a Dutch astronomer called Hedrick Van De Hulst, argued in his findings that there is existence of such radioactivity. The great finding of Ewen’s research was of similar emission (in 1951). This discoveries became the basis in mapping the configuration of our home galaxy, normally referred to as the Milky Way. Due to these findings the southern part of the sky on a very dark and cloudless night can be seen; these discovery therefore is a complete evidence that shows that Milky Way without any doubt is a planar (Christiansen, 1987). The sixth discovery in relation to radio astronomy actually earned the inventors the Nobel Prize in relation to physics field; this particular award happened in the year 1978. This discovery came into existence at course of simultaneous research that were much unrelated in nature as seen in Jansky’s discovery. It became more of coincidence when Robert Wilson and Arno Penzias while working in a Laboratory at Bell Telephone Company which happens to the exact location where Jansky’s discovery. Penzias and Wilson while working in that laboratory made a discovery, but that was after they carried out a thorough experimentation. Their experimentation was to show that the sky is completely covered by a background microwave radioactivity, therefore proving the fact that the space has a general temperature of about three degrees beyond complete zero. The importance of this discovery was not realized early enough but later it happened to be the most crucial in relation to assumptions about where the universe originated from. The discovery provided quite a number of evidence that favored the big bang philosophy (Benneth and Shostak, 2011). References Benneth & Shostak.2011. Life in the Universe 3rd edition, Pearson/Addison Wesley Benneth D. & Voit.2001. The Cosmic Perspective 7th edition, Pearson/ Addison Wesley Burke, F. B. & Smith, F. G. 2010 An introduction to radio astronomy, Third edition, Cambridge University Press Christiansen, N. & Hogbom, J. 1985, Radio Telescopes, Cambridge University press: Cambridge Christiansen, W. & Hogbom, J.1987. Radio Telescopes 2nd Edition Robertson, P.1992. Beyond Southern Skies; Radio astronomy and the parkes telescope Rohlfs, k. & Wilson, L.2006, Tools of Radio Astronomy, Springer: Berlin Smith, G. F.2013. Unseen Cosmos, Oxford University Press Sullivain W.2005. The early years of radio astronomy; Reflections fifty years after Jansky’s discovery. Cambridge University Press Swenson, W. G. 1980 An amateur Telescope, Parchart Publishing House Read More

e played a key role in repeating Karl Guthe Jansky’s project, but some how worked at higher frequencies, and he proceeded to conduct the first sky survey at very high radio frequencies ( Sullivain, 2005). Since then, radio telescopes have witnessed one of the first raising advancements. The examples below show very clearly how this field has been growing over the last few decades. The Lovell Telescope with 250 foot in Jodrell bank, England, was finished in 1957 and it became the first large steerable dish and it was popular for detecting sputnik.

The length of the central tower that provided support to the feed at the prime focus was only about 30% of the reflector diameter. The parkes Telescope was constructed almost the same time as the Green Bank foot telescope, but it has a fabulous alt-az shape and is still in use, with multibeam receivers making HI and pulsar surveys of the southern sky, a very simple and less expensive was build immediately the 140 telescope in Green Bank underwent construction delay. It was a mobile telescope able to move in elevation along the southern line but in azimuth.

It could observe sources over a wide variety of declinations, but only in a very short distance. The prime-focus feeds could shift slightly in the east west direction to track a source for some minutes while they remained within the focal ellipsoid. The surface of the 300-foot telescope was an open mesh that was made up of square holes of almost 6mm on a side; this was to reduce both the weight, as well as, the wind loading (Christiansen, 1987). Arecibo radio telescope situated in Arecibo Puerto RICO is the biggest filled-aperture telescope on the globe; its 10001ft dish is properly secured in the ground.

The antenna beam is steerable (by means of a moving receiver) within about 20 degrees of the zenith. It is also the world’s largest planetary radar (Robertson, 1992). Advantages of interferometer 1 With the use interferometer, radio astronomers are able to achieve high angular resolution. The resolving power of this device is set by distance between its components, rather than its components 2 Interferometer is basically sensitive to small isolated sources rather than extended sources and background radiation.

Plus, it is also somewhat insensitive to disturbance 3 An interferometer which comes with horizontal baseline is not actually affected by the plane-parallel component of atmospheric refraction that in many cases would delay signals reaching the two telescopes at the same time. 4 Interferometer has the ability to determine the positions of compact radio sources with accuracy Major discoveries that was possible after detection of radio waves from waves from space and how they changed understanding of the universe Quite a number of findings on radio astronomy field have been made several years after the discovery of radio waves.

These discoveries have in many ways changed the way people have viewed the universe for years. Discussed below are seen discoveries that have changed and revolutionized the way people used to think about the universe. Radio telescopes, for sure, have made the universe to be understood much better (Robertson, 1992 pg. 87). One of the discoveries was by Harod Ewen, at Havard. This was actually the distinct occurrence signal produced by a massive quantities of atoms specifically hydrogen atoms; this hydrogen atoms that covered the entire space amid the stars.

This discovery was totally distinct from extra-terrestrial signals that Reber and Jansky observed. The kind emissions generated by the deceleration or acceleration of charged electrons were wideband. (Sullivain, 2005) The cause of bulky emission of radiation has been seen to thermal sizzling substances or in other cases because of magnetic field motions that have circular shapes. At one thousand four hundred and twenty one Megahertz which is a wavelength of twenty one centimeters, a distinct occurrence radiation generated by hydrogen atoms happens as a result of an electron existing inside the atom swiftly changes spin axis’ direction.

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