The great cosmic discovery - II

Prof H Nandakumar Sarma *

The discovery of microwave background radiation, neutron star, pulsar; trying to understand the cosmic forces, the discovery of anisotropy of cosmic microwave background radiation, the discovery of Higgs boson ( God’s particle ), the detection of gravitational wave and black hole etc are some of the exciting moments in the understanding of the universe. In this series, we trace some of the great cosmic discovery made from the beginning of the 20th century to the present day.

Among the great scientists of all times, few stand out as affecting man’s understanding of the very structure of the universe and his place in it. Galileo Galilei and Sir Isaac Newton were two such giants of science. Albert Einstein, in our own time, has achieved a placed of similar stature.

Born in Ulm, Germany in 1879, there was little in his childhood that portended the outstanding heights he would achieve. He was quite shy and was seldom accepted in the games of his fellows.

At school he did poorly, and dislike the study of languages. Albert read books on natural science, geometry and other areas of mathematics and mastered them in the quiet of his own study. His knowledge of mathematics far exceeded the learning of his teachers in the German schools.

The universe of Newton ticked on without a hitch for about two hundred years. Any time before 1905 in Berne, not two hundred yards from the ancient clock tower, a young man came to live and then time and light first began to go awry.

This young man was Albert Einstein. By that time he was married and had two children to support. Einstein was appointed as clerk in the Swiss Patent Office on 16th June 1902. He was selected as a technical expert.

The work involved spending eight ­hours on a stool, pouring over technical data. He had to discover what was unique in the invention for which the patent had been filed Later he would call it a ‘cobbler’s jobs’.

While at the Patent Office he wrote his formula for success
A{success)= X(work) +Y(Play) + Z(keep your mouth shut)

In 1905 while still working at the Patent Office, Einstein dazzled the world of science when dashed off research papers on Special Theory of Relativity and Photoelectric Effect.

To Newton, time and space formed an absolute framework, within which the material events of the world ran their course in imperturbable order. Einstein proved that time is a variable; a fourth dimension to be added to the three commonly accepted three dimensions of space.

Time is dependent upon the motion or speed If one could travel away from the earth at the speed of light, time would come to a stop for him. Einstein’s theory even changed the concept of the ruler as a fixed measuring rod.

Another important point in Einstein's theory of relativity is the mass of a body also depends upon its speed As the object moves faster its mass increases. Einstein’s theories were found to be amazingly accurate when put to the test of practical experimentation.

The special theory of relativity challenges common sense or our perception of reality. There is no absolute space and absolute time. Some of the highlights of special theory of relativity are:

Moving clock runs slower as observed by stationary observer. Therefore there is an increase of lifetime of unstable particle at high velocity. A moving rod appears to shrink in the direction of motion. There is an increase of mass of particle with increase in velocity.

The above consequences of the special theory of relativity had been verified by various experiments. The fourth which is a continuation of the special theory of relativity signifies the relation between mass and energy and laid the foundation of nuclear energy.

So, the paper is not just about light or as its title says, The Electrodynamics of Moving Bodies. It goes on the same year to a postscript saying energy and mass are equivalent
E = mc2
where E is the energy, m is the mass and c is the speed of light in vacuum.

It is remarkable that the first account of relativity should instantly entail a practical and devastating prediction for atomic physics. To Einstein, that comes from a profound insight into the processes of nature herself, but particularly into the relations between man, knowledge and nature.

In 1915 Einstein published his General Theory of Relativity ( GTR ). Some of the important implications of GTR are : the bending of light by gravitational field can lead to gravitational lensing, gravitational red shift of light, the existence of black hole, the existence gravitational wave etc.

The gravitational field near the sun would cause a glancing ray of light to bend inwards-like a distortion of space. Einstein’s prediction was confirmed during the eclipse on 29 May 1919 by two expeditions sent by the Royal Society, London to Brazil and west coast of Africa.

In 1921 he was awarded the Noble Prize in Physics, not for his theory of relativity or his theory of the conversion of mass to energy, but for his explanation of how and why special metals emit electrons after light falls on their surfaces; the laws of photoelectric effect and its explanation.

In 1924 Satyendra Nath Bose from Dacca University (in what was the India), wrote to Einstein asking for his help in getting a paper published Bose had already sent to the Philosophical Magazine, where it has been turned down. Paper showed how Planck’s distribution law for photons could be derived from first principles.

Duly impressed, Einstein translated it into German and the paper was, published in 1924 in Zeitscherift Physik. Thus was born the concept of ‘Bose­ Einstein’ statistics for quanta (‘bosons’) carrying integer value of spin. There is no limit to the number of bosons that can simultaneously occupy one quantum state-at low enough temperature-Bose-Einstein condensation will take place.

Einstein laboured for the last quarter century of his life to Unified Field Theory. The purpose of a Unified Field Theory is to construct a bridge between electromagnetic force and gravitational force.

Believing in the harmony and uniformity of space, Einstein looked for a single edifice of physical laws to encompass both the phenomena of atom and phenomena of outer space. Ultimately the features of the universe distilled down to a few basic quantities- space, time, matter, energy, and gravitation. Einstein’s Unified Field Theory sought to culminate and climax this coalescing process.

In December 1931, Charlie Chaplin invited Albert Einstein, who was touring America, to attend the premier of City Lights. As the two men emerged from the hall after the show in Los Angeles, the physicist was astonished by the scene on the street.

A huge traffic stopping crowd was there to wave at them. No stranger to adulation himself, Einstein, however, was not prepared for this and looked Charlie Chaplin quizzically. “They cheer me because they understand me, and they cheer you because they do not understand you”, Chaplin told Einstein.

On April 12, 1955, Einstein paid a visit to the Institute for Advanced Study, Princeton. His assistant asked him if everything was comfortable. His reply was prophetic, “Everything is comfortable. I am not”. He died three days later.

In a life time Einstein joined light to time, and time to space; energy to matter, matter to space, and space to gravitation.