A telescope is a device that makes it possible to view distant and faint objects as though they were near (Telescope, 2009). The discovery of the telescope and subsequent improvement in technology has gone a long way to transforming the way we view the universe. Telescope helps in viewing distant planets, stars, and heavenly bodies. To understand the mechanisms of operation of a radio telescope, it is important to initiate by taking a look at its discovery as well as the events that potentially led to the discovery. The essay will take a look at how the discovery and improvement in telescope have transformed our view of the universe.
In the early part of the 20th - century, scientists did not know that radio waves can also come from non-terrestrial sources. This was why the discovery of radio astronomy took them aback (Telescope, 2009). Karl Jansky, in the early 1930s, was the first to discover single-dish radio astronomy. Karl Jansky is a Bell Laboratories scientist, and he was trying to find out the source of noise showing up in his receiver at 20 MHz region of the radio spectrum, radio astronomy was accidentally discovered. (Fredsti ., n.d; Telescope, 2009).In order to search out the source of the noise, Jansky built an antenna and with it he found out that the source was extraterrestrial. Jansky published his work in the NY Times of May 5, 1933, but it did not meet acceptance by the astronomers of the day (Bout. 2010).
However, the work of Reber brought radio telescopes to limelight. Fascinated by Karl Jansky’s work, Grote Reber an electrical engineer, proceeded to do more research. However, he believed that that the signal came from a thermal source that is a very hot object. Therefore, he believed that it should be more easily detected at higher frequency. Rather than employing the 20 MHz used by Jansky, Reber determined to use 3300 MHz, a frequency that was not obtainable in his day (Fredsti S.J., n.d; Bout P.V, 2010).
Reber used his resources and materials without sponsorship and built the first single dish radio telescope in 1937. Reber’s radio telescope is about 31 ft in diameter, and since he was not able to achieve the 3300 MHz speculation, he was able to achieve it at a 160 MHz. According to Bout (2010), Reber " mapped the sky in 1943 and published the results in the Astronomical Journal in 1944.”.
After the early days of the discovery of radio telescope, the advancement of technology in this field led to the discovery of interferometer. Interferometers are radio telescopes that can be used in combining signals from different telescopes in various locations together into one image. In this case, the resulting image would look as though it was obtained from a single giant telescope (Telescope, 2009). An interferometer could consist of two antennas separated by about 7.5 meters in the east-west direction (Abshier, 2007). An interferometer has a lot of advantages over a single dish radio telescope, and the advantage includes: Firstly, an interferometer is sensitive to small isolated sources instead of extended sources and background radiation. Secondly, it is also sensitive to continuous interferences. In addition, interferometers can be used in distinguishing the separation of closely paired and bright objects like double stars. It is a very important optical instrument which astronomers speculate that can be used in viewing distant planets that have not yet been discovered. Creating a very sharp and bright image is a great edge which interferometers have over single dish radio telescope. As a matter of fact, the image must be bright enough in order to give a clear representation of the object in space.
Interferometer can be used in the measurement of small displacement, changes in the refractive index and surface irregularity (Xia et al., 2015). They are most widely employed in sciences and the industry. In addition, they can be used in forming continuous wave Fourier transform spectroscopy in order to analyze light that contains characteristics of emissions and absorption regarding the a material. The principle of superposition of light is the principle on which the optical interferometer is founded (Telescope, 2009; Xia et al., 2015). Of course, there are different kinds of interferometer but each kind of the device functions on the same basic principle of the superposition of light.
The detection of radio waves opened up room for countless numbers of other discoveries (Webb, 2010). This is because of the immense significance of radio waves in the development of devices today. Radio waves are widely employed in optical instruments, electronic devices, smartphones and countless numbers of devices. More so, our view and conception of the universe has been changed with the detection of radio waves and subsequent discoveries. In fact, the world would have still been myopic if radio waves have not been discovered (Maggio, n.d;W ebb, 2010).
Optical telescopes are quite limited when compared to radio telescopes. Radio telescopes assist astronomers in viewing objects that cannot be seen with optical telescopes. More so, the largest radio telescope, the Arecibo telescope in Arecibo, Puerto Rico, has been enormously employed in viewing distant objects in our universe (Hillas, 2013).
The telescope was used in viewing the mercury’s orbit. This helped Gordon Pettengil to develop a theory with respect to the rotation of Mercury. Not only this but also the study of Mercury and the planet at large helped scientists and astronomers to understand more about the planets and their rotation round the sun. Furthermore, the telescope was used for asteroid imaging. Of course, scientists had been able to view asteroids for a long time before the development of radio telescopes but with radio telescopes, asteroid imaging became possible (Sava et al., 2014). This simply implies ability to view and represent how the asteroids look like. Another important discovery made with the Arecibo telescope is binary pulsars. A binary pulsar is a pulsar having a white dwarf or a neutron star close by which more round the pulsar so as to balance the mass and the gravitational direction of the pulsar (Webb, 2010). Millisecond or "recycled" pulsars can also be viewed with the telescope. These are neutron stars that have very fast rotational period. They were first discovered in 1983 with the aid of radio telescopes. Prebiotic molecules in a starburst up to 250 million light-years away from the earth were discovered in 2008 with the aid of the Arecibo telescope (Buckley, 2001). The discovery of organic molecules gave a hint that there could be the presence of life in other planets and even in other solar systems (Maggio, n.d).
Other kinds of telescopes have been discovered including infrared, ultraviolent, x-ray, gamma-ray telescopes and so forth. The launch of Japan’s Space Observatory Program satellite in 1997 improved the radio astronomy program which was known as Very Long Baseline Interferometer (VLBI), and this created a radio telescope bigger than the Earth. With the aid of the satellite and a combination of up to 40 Earth-based radio telescope, a radio image of about three times clearer than images viewed before became possible. (Mirzoyan, 2014; Mirzoyan, 2013; Telescope, 2009)
Our understanding of the universe has been immensely improved with the development and advancement of radio telescope. Astronomers have been able to visit other parts of the planets and even install satellites in the space with the understanding of the universe. In addition, a number of heavenly bodies and planets have been discovered. More so, scientists can now predict events with great certainty and accuracy. Such events include eclipse of the sun, eclipse of the moon and so forth. The discovery and advancement in telescopes and astronomy allow scientists to make complex calculations with respect to the universe
Advancement in telescopes helped us to understand the magnetic features of the universe. Radio telescopes can be used in studying magnetic fields in the ISM, galaxies, and AGN (Vallée, 2004). Garrett (2007) pointed out that the universe comes towards us when we go deeper in the radio. More so, radio interferometers can be used in detecting and imaging resolved gravitational lens phenomena because of their high resolution. When radio telescopes are magnified, they become more capable for detecting cosmologically distant star-forming galaxies. A number of researches and upgrades are being carried out to develop radio telescopes in the future. According to Garrett M. (2007), intensive activity is going on in this field on many telescopes such as EVLA, e-MERLIN, e-VLBI and many more. Besides the upgrades, a number of telescopes are currently being constructed (Shepherd et al., 2013).
Today, we are all enjoying the beauty of the internet, mobile communication and so forth, but these would have been impossible without the discovery of radio waves and radio telescopes. Moreover, further advances in this field such as the Very Long Baseline Array can be employed into a number of useful applications. (Su et al., 2003; Burgwal et al., 2011). Nanotechnology is also expected to have a great impact in the development of modern radio telescopes. For instance, the square kilometer array-nano-Jy high-resolution astronomy which is the international radio telescope for the 21st century, is a global project to design and build a new generation radio telescope at meter to centimeter wavelength. Nanotechnology can be employed in enhancing the development radio telescopes in the future. It is important to note that the development in radio waves and electromagnetism paved a way to the recent discovery in the field of telescope and astronomy. Scientists like James Clerk Maxwell, Oliver Heaviside, Willard Gibbs, Heinrich Hertz, Max Planck, Albert Einstein, Louis de Broglie, Erwin Schrodinger and many others set the pace for the development of the principles of radio telescope by Jansky in the early 20th century. (Shepherd et al., 2013).
In short, the development of single dish radio telescope is an interesting one. It began with the work done by scientists such as James Clerk Maxwell, Heinrich Hertz, Max Planck, Albert Einstein and so forth set the pace to the development of radio telescope. Radio astronomy has greatly advanced since the detection and development of radio telescope. Optical telescopes are quite limited when compared to radio telescope because radio telescope can be used in viewing objects that cannot be viewed with optical telescopes. In the recent times, a lot of advances have been made in radio telescope such advances includes the development of the radio interferometer, very long baseline array and countless numbers of other interesting technologies.
This paper takes a look at the discovery of single dish radio telescope and radio astronomy in general. It also evaluated how radio astronomy and radio telescope has advanced every year. In addition, the applications of radio astronomy were discussed including how it has greatly transformed how we view the universe. Astronomers are now able to achieve mind-blowing feats with tremendous and profound results as a result of radio telescopes. The National Aeronautics and Space Administration (NASA) is a body that handles nonmilitary programs in the exploration and scientific study of space. Radio telescope and its advancement have great usefulness to NASA studies.
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