Category Scientist & Invensions

When and how the fist steam engines were built?

The invention of the steam engine during the eighteenth century had a fundamental effect on man’s progress. Some earlier forms of this machine had appeared during the previous century. The most famous were those of papin whose work provided a great stimulus for research into steam.

Papin built a boat with steam operated paddles, but builders of sailing boats were hostile to this new craft and papin could not make much progress with it. However, he had proved what a powerful force steam could be in locomotion. Thomas newcomen built a steam engine in 1705. It began to be used for pumping water out of mines about six years later, and by 1725 the engine was widely used in collieries. It continued in use for many years although it was not very efficient and worked slowly. It was James watt (1736-1819) who examined all the previous efforts and perfected them into a steam engine that worked fast and efficiently. For this engine watt invented a steam condenser that was separate from the cylinder which worked the piston.

The steam engine had a sensational success and proved itself enormously useful, especially in factories where it replaced machines that had previously been worked by water or animal power. It was eventually used as a locomotive to pull wagons.

 

Picture Credit : Google

By whom the electric light bulb was born and how?

Thomas Edison had discovered in his experiments that there were certain bodies through which electric power flowed more easily. He called these good conductors and other bodies that resisted the flow of electric power he called bad conductors. When electricity tried to travel along a bad conductor the latter would resist so much that it glowed until became white-hot.

A carbon filament, for example, gave out a good deal of light; but the light did not last very long because the carbon would soon burn itself up as it was in contact with the oxygen in the air.

Edison then carried out an experiment inside a glass bulb from which he had removed all the air. This time the light of the glowing filament lasted much longer and the fist electric light bulb was born.

Carbon filaments have now been replaced by tungsten wire as its high melting point, low rate of evaporation and low electrical consumption make it most suitable for use in light bulbs. A further improvement has been the introduction of an inert gas in to the bulb. This was at first nitrogen but is now a mixture of 88 per cent argon and 12 per cent nitrogen.

 

Picture Credit : Google

Are laser devices inspired by Einstein’s Theory of Stimulated Emission?

You might have come across laser pointers while attending a seminar or conference, or perhaps used it to play with your cat or dog. In the sixty years since physicists demonstrated the first laboratory prototype of a laser in 1960, it has been put to use in numerous ways from barcode readers to systems for hair removal.

The technology behind laser devices is based on Einstein’s Theory of Stimulated Emission. This theory came a year after the discovery of general relativity. Einstein imagined a bunch of atoms bathed in light. He had earlier discovered that atoms sitting in their lowest energy state can absorb photons and jump to a higher energy state. Similarly, higher energy atoms can emit photons and fall back to lower energies.

After sufficient time passes, the system attains equilibrium. Based on this assumption, he developed an equation that can be used to calculate what the radiation from such a system would look like. Unfortunately, Einstein’s calculations differed from the laboratory results. It was obvious that a key piece of the whole puzzle was missing.

Einstein resolved this by guessing that photons like to march in step. This would mean that the presence of a bunch of photons going in the same direction will increase the probability of a high-energy atom emitting another photon in that direction. Einstein labelled this process stimulated emission. He was able to rectify the disparity between his calculations and the observations by including this in his equations.

A laser is a device to harness this phenomenon. It excites a bunch of atoms with light or electrical energy. The photons released as a result are channelled precisely in one direction. Lasers are used in delicate surgery or industrial processes that require precision.

Picture Credit : Google

Why is it said that Albert Einstein had even contributed to the daily functioning of Wall Street?

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.

Picture Credit : Google

Does GPS primarily use the General Theory of Relativity?

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.

Picture Credit : Google

In which universities did Einstein serve as a professor till the 1930s?

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.

Picture Credit : Google

Suggested Posts