Biography on Christian Andreas Doppler & The Doppler Effect - Term Paper Example

Biography on Christian Andreas Doppler and The Doppler Effect Christian Andreas Doppler was a world renowned physicist. He was born in 1803 in Salzburg, Austria. He came from a relatively well off stonemasonry family and as was the tradition, he was expected to take over the family’s freemasonic business. When he turned 19 years of age, he was not so sure about what he wanted to pursue in college, so his parents recommended that he join the Vienna Polytechnic Institute to pursue Math. 3 years later, in 1923, Doppler graduated from the Polytechnic and enrolled at the University of Vienna, to pursue further studies in Math, astronomy and mechanics. He hoped to become a Math teacher after his studies (Gill, 1965). He started teaching temporarily at the University of Vienna after two years at at the University. It was at this time that he published his first four mathematics papers. For several years, he tried to apply for a permanent teaching position in various schools, universities and colleges (Maulik, 2005). All this while he was supporting himself by working as a bookkeeper at a local cotton spinning mill. Life became too hard for him as he was not getting the permanent job he wanted, so he decided to pack and go look for better pastures in America (Kinsella and Pertoff, 2004). However, just before he left, he received a job offer in Prague at the Technical Secondary School. However, he soon found himself bored and yearning for something that was more exciting than elementary mathematics. He therefore applied for a job as a teacher of higher mathematics. In the meantime, he did not let his mathematical skills rust away. He ensured that his mathematics skills were always sharp by doing part time work at the Vienna Polytechnic Institute (Coman, 2004). Doppler did not have to wait for long before a major job opportunity presented itself to him. While working as a part timer at the Vienna Polytechnic, the position of Geometry and Mathematics Professor became vacant and he applied for it, confident that he would get the job. Getting the job, however, was not as smooth a ride as Doppler had hoped it would be. He had to fight off competition from several other top contenders (Baxter, Allan and Morley, 1999). This situation affected him and he began to experience poor health. The strain of teaching added to his health woes. Soon his students were complaining about his tests which they said were too unfair and harsh. He eventually asked for sick leave, and it is during this time of rest that Doppler presented on of his most famous papers. The title for the paper itself was: “on the Colored Light of the Double Stars and Certain Other Stars of the Heavens”. He presented this paper in Prague, at the Royal Bohemian Society (Kinsella and Pertoff, 2004). In this paper he came up with a theory that stated that the waves of light and sound normally change if the wave source moves or if the wave’s observer moves. To test his new theory, Doppler arranged for a trumpeter to play the same note while standing on a moving train for duration of two days. There were some trained musicians on hand to record any difference in the sound. At first, nobody was convinced that Doppler’s theory was feasible. Many critics argued against his theory, but he did not let their pessimism discourage him. He published a second and much better version of his theory and this earned him much respect from the science world (Gill, 1965). Doppler was elected to become an ordinary member of the Vienna based Imperial Academy of Sciences in 1848. He also got an honorary doctorate from the University of Prague in the same year (Kinsella and Pertoff, 2004). In 1850, the Institute of Physics at the University of Vienna was created. By this time Doppler was 47 years old and he became the first director in the Institute. This gave him an opportunity to lecture on and present his light and sound wave theories to wider audiences. Despite having finally gotten the job that he had always dreamed of, his health continued to deteriorate. This forced him to move to move to warmer Vienna in 1852. His health did not improve, and he died in 1853 aged 50 (Maulik, 2005). Christian Doppler contributed a lot to the science of magnetism, electricity, optics as well astronomy. However, perhaps his greatest achievement was his invention of ultrasonagraphy. He discovered the shift of frequency as pertaining to light. He published his theories on light frequency on the paper that he presented at the Royal Bohemian Society in 1842. In 1955, the first ultrasound vascular application was published in Japan by Satomura. There has been much advancement on the ultrasound technology since it was first formulated by Doppler (Coman, 2004). Ultrasonagraphy has become the main non-invasive assessment method for heart and blood vessels. The Doppler Effect Doppler’s discovery about shift of light became known as the Doppler Effect. The Doppler Effect is a principle which relates to both sound and light as longitudinal waves in the matter and ether respectively (Baxter, Allan and Morley, 1999). Although Doppler was wrong at first about his theory of light being a longitudinal wave, he corrected this mistake and perfected his principles on the shift of light and sound in a later paper in 1846. In this version of his theories, Doppler considered the motion of the observer and that of the source (Kinsella and Pertoff, 2004). Doppler made his discoveries during the 19th century, at a time when the development of train networks was spreading at a fast rate. Doppler observed the phenomenon that the sound of a train’s pipe sound much higher while approaching than after it had passed by. He realized that this phenomenon was an effect of the nature of waves whereby, sound waves of oncoming objects tend to be compressed. He explained that this compression was due to the difference between the speed of moving and non-moving entity (Kinsella and Pertoff, 2004). This compression caused the preceptor to receive more waves per the standard time. This is what caused higher tone and higher frequency. However, the preceptor received fewer waves after the object had passed since there was no compression through the speed difference. That is why the preceptor perceived lower tone at lower frequency (Baxter, Allan and Morley, 1999). Doppler’s discoveries gave rise to the technology of ultrasound as we know it today. In 1955, Yasuhara Nimura and Shigeo Satomura of the Institute of Scientific and industrial Research, Japan used ultrasound for the study of motion in the cardiac valves and in peripheral blood vessel pulsations (Schuster, 2005). By using an echocardiogram and the Doppler radar, one can easily assess blood flow direction (Hiebl and Musso, 2007). The same mechanism can be used to determine the velocity blood at any one given moment. A group of American Scientists, led by R. Rushmer used ultrasound to measure transcutaneous continous-waveflows. They also pioneered spectoral analysis in extracranial and peripheral brain vessels in 1958 (Gill, 1965). The technique used in measuring blood flow velocity can also be applied to other medical fields such as obstetric ultrasonography, medical ultrasonography and neurology. Ultra sound imaging is a common feature in many hospitals today (Coman, 2004). It is performed by observing the pattern produced by emitting a pulse. The pulse reflection depends mainly on the difference in impedance between the two tissue structures. The velocity tissue sound is normally constant, therefore it does not affect the time between the pulse emission and reception of reflected signal, which is mainly determined by the distance. Since the distance is relative, the structures will reflect differing amounts of emitted energy, which will be shown as varying amplitudes (Maulik, 2005). During a normal Doppler ultrasound, some gel is normally applied on the patient’s skin to act as sound wave conductor. A transducer is then moved over the specific area that is being tested. The resulting sound waves are then used to create images of tissues and organs. It has been used in hospitals around the world to diagnose a wide range of medical complications (Hiebl and Musso, 2007). Doppler ultrasound is applied in many hospital settings to measure sound waves when diagnosing blood flow and circulation related conditions (Baxter, Allan and Morley, 1999). The technology is used to measure the speed of blood flow, thus it can accurately be used to indicate any circulatory problems. It is also quite easy to find blood clots using Doppler’s ultrasound, which can also be used to locate narrowed arteries, blocked vessels or even plaque build up (Kinsella and Pertoff, 2004). There are different types of Doppler ultrasound: color Doppler, pulsed Doppler and power Doppler. The color Doppler technique is used to estimate a vessel’s flow velocity by way of color coding the information. The direction of blood flow towards or away from the transducer is normally assigned the color blue or red. Pulsed Doppler technique makes it possible to position the sampling volume in a vessel as visualized on a grey scale image. This technique displays a graphical presentation of the different blood velocities within he sampling volume vis a vis time. The power Doppler technique depicts the power or amplitude of Doppler signals as opposed to the normal frequency shift. This makes it possible for the technician to detect a wider range of shifts, which leads to enhanced visualizations of small vessels (Baxter, Allan and Morley, 1999). Doppler ultrasound is the most common type of ultrasound used in hospitals and laboratories around the world. This is because the technique comes with the benefit of being less invasive than other similar techniques (Hiebl and Musso, 2007). Since it is performed outside of the body, it is a painless procedure, with minimal discomfort. There are very few risks associated with the use of Doppler ultrasound due to its non-invasive nature (Schuster, 2005). It is convenient for detecting serious and not so serious condition on patients’ bodies (Kinsella and Pertoff, 2004). References Baxter, G.M., Allan, P. and Morley, P. (1999). Clinical diagnostic ultrasound. Hoboken, NJ: Wiley-Blackwell Coman, I.M. (2004). Christian Andreas Doppler – The man and his legacy. European Journal of Echocardiography, Vol. 6, No. 1, pp. 7-10 Gill, T.P. (1965). The Doppler Effect: An introduction to the theory of the effect. Boston, Mass: Logos Press Hiebl, E. and Musso, M. (2007). Christian Doppler: Life work, principle and applications: Proceedings of the commemorative Symposia in 2003, Satzburg, Prague, Vienna, Venice. New York: Living Edition. Kinsella, J. and Pertoff, M. (2004). Doppler Effect. London: Salt Publishing Maulik, D. (2005). Doppler ultrasound in obstretics and gynaecology. Basel, Switzerland: Birkhauser. Schuster, P. (2005). Moving the stars: Christian Doppler, his life, his works and principle, and the world after. New York: Living Edition Read More