My Science School

Many of the everyday mechanisms  we take for granted, such as automatic lighting of street lamps as daylight fades, how the elevator doors remain open when there is someone in the way, the device that regulates printer toner, and breathalyser tests- all of these use photoelectric cells that are based on Einstein’s theories.

Photoelectric cells, originally used to detect light, used a vacuum tube containing a cathode (to emit electrons) and an anode (to gather the resulting current). Modern versions of these “phototubes” have advanced to semiconductor-based photodiodes. These find applications in solar cells and fibre optics telecommunications.

Photomultiplier tubes are a variation of the phototube. Devices like solar panels that turn light into electricity are possible because of the photoelectric effect.

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Wall Street in New York is the home of the New York Stock Exchange. An army of mathematicians are employed there to analyze and predict the stock price variations. Their employers can potentially earn millions of dollars based on their predictions about which way the prices will jump.

Mathematicians however say that stock markets follow a random walk. This means that unless some spectacular event occurs, the prices have the same chances of decreasing and increasing at the end of any day. If patterns do exist, they will be elusive and difficult to find, which is why financial mathematicians are paid huge sums.

Some of the intricate mathematics used for stock market analyses can be traced back to Einstein. He developed the fluctuation-dissipation   theorem to explain the random movement of particles found in liquids or gases.

This movement called ‘Brownian motion’ was first observed by the Scottish biologist Robert Brown. Brownian motion is highly similar to the price fluctuations seen in stock markets. The similarity was observed in 1970 and since then it has been used on Wall Street. Einstein’s paper on Brownian motion is still used as the basis for certain stock market predictions.

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Einstein’s General Theory of Relativity has predominantly found applications in astronomy through gravity waves, big bangs and black holes. One of its rather unexpected applications was in the multi-billion-dollar industry centred around the Global Positioning System (GPS).

All GPS navigators including Google Maps work by measuring the distance from one point on Earth to one of the satellites orbiting our planet. Though GPS was originally developed with military use in mind, it has since become an inherent part of everyday life.

GPS is based on a collection of 24 satellites, each carrying a precise atomic clock. A hand-held GPS receiver which detects radio emissions from any satellite overhead can find the latitude, longitude and altitude with accuracy up to 15 metres and local time to 50 billionths of a second. The clocks on satellites are ahead of those on Earth by 38,000 nanoseconds. The reason for this is explained by the General Theory of Relativity. Though it may appear as an inconsequential amount of time, if these nanoseconds are not taken into account, GPS systems would be highly inaccurate.

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Despite publishing four ground-breaking scientific papers in 1905 and earning his doctorate, Einstein still had difficulty finding a teaching job. He finally became a lecturer at the University of Berne in 1908. He received more opportunities in academia as his reputation as a theoretical physicist grew.

A year after joining the University of Berne he became an associate professor of physics at the University of Zurich. In 1911, he became a full professor at the University of Prague but returned after a year as a full professor to Zurich. The highlight of his academic career was when he became a professor at the University of Berlin and a member of the Prussian Academy of Sciences.

He had also been the Director of the Kaiser Wilhelm Institute for Physics. Einstein earned the salary of a professor without any teaching duties at the University of Berlin. As a result, he could pursue his research full time. He remained in the University of Berlin until the early 1930s.

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Einstein received a paper from Indian scientist Satyendra Nath Bose in 1924. The paper was on a new perspective: to think of light as a gas filled with indistinguishable particles. Einstein recognized the relevance of the paper. He translated it to German and submitted it on behalf of Bose to the famous journal Zeitschrift fur Physik. Bose went to Europe and worked with Einstein at the X-ray and crystallography laboratories there.

Einstein worked with Bose to extend his idea to atoms and they predicted a new state of matter which came to be called the Bose-Einstein Condensate. A Bose-Einstein Condensate is a dense collection of particles with integer spin known as Bosons.

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Einstein was primarily in pursuit of a universal field theory after the General Theory of Relativity. He engaged in a series of unsuccessful attempts to further generalize the theory of gravitation in order to unify and simplify the fundamental laws of physics, in particular, gravitation and electromagnetism.

This ‘theory of everything’ was supposed to refute the quantum theory. Though he published a paper in 1929 which supposedly had such a theory, Einstein himself had to acknowledge the errors in his argument.

Einstein remained in the cocoon of his research, largely ignoring other developments in physics and quantum theory. He however, did a few collaborations with the Indian scientist Satyendra Nath Bose, the Austrian Erwin Schrodinger and his Hungarian former student Leo Szilard.

In the 1930s he worked together with Russian physicist Boris Podolsky and the Israeli physicist Nathan Rosen. Nevertheless, his search for the ‘theory of everything’ and his distrust of the quantum theory consumed him in his later years.

Einstein had also made contributions to the development of the quantum theory. The concept of light quanta (photons) was used by him in 1905 to explain the Photoelectric Effect and to develop the quantum theory of specific heat.

Despite playing a main role in its development, Einstein regarded the quantum theory only as a temporarily useful structure.

His efforts were primarily in formulating the unified field theory which he believed would turn out to be the reason behind quantization of energy and charge. He felt that the quantum theory lacked the simplicity and beauty befitting a rational interpretation of the universe.

He engaged in a series of private debates with physicist Niels Bohr about the validity of the quantum theory later on. The 1920s witnessed his prolonged public debates with Niels Bohr and Werner Heisenberg over quantum mechanics. Einstein was rather lukewarm about the quantum theory even from a philosophical standpoint, saying in 1926 that he was convinced God does not throw dice. However, Bohr showed the ambiguities in Einstein’s reasoning.

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The Nobel Prize in Physics 1921 was awarded to Albert Einstein “for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect.”

Albert Einstein received his Nobel Prize one year later, in 1922. During the selection process in 1921, the Nobel Committee for Physics decided that none of the year’s nominations met the criteria as outlined in the will of Alfred Nobel. According to the Nobel Foundation’s statutes, the Nobel Prize can in such a case be reserved until the following year, and this statute was then applied. Albert Einstein therefore received his Nobel Prize for 1921 one year later, in 1922.

However, Einstein did not attend his prize giving. Though he was informed that he was to receive the prize, he continued with a lecture tour of Japan.

Einstein has published four papers on the general theory of relativity. In the third paper, he used general relativity to explain why Mercury’s closest point to the Sun (its perihelion) is erratic.

Gravitational influence of the Sun and other planets was not sufficient explanation for this movement. Some even went as far as to suggest in the 19th century that a new planet, Vulcan, orbiting close to the Sun was the reason! But this was disproved as Einstein succeeded in calculating the shift in Mercury’s perihelion using the general theory of relativity.

The theory not only explained previously unexplained phenomena, it could even predict events that have not occurred yet. In 1919, the theory was validated again when Sir Arthur Eddington, secretary of the Royal Astronomical Society of London travelled to the island of Principe off the coast of West Africa. There, he had the perfect view of the Sun during a total eclipse.

The light emitted from a certain strand was measured and it was found that the light was deflected, or bent, by just the amount that Einstein had predicted. Einstein’s fame skyrocketed after this.