Albert Michelson (1852 – 1931)
After a while, they sailed to the western shore and reached California. By 1849, California had acquired the reputation of the promised land of gold. Albert’s father, Samuel Michelson owned a small dry-fruit shop in Cleaver’s country. Albert received primary education in the local school. For high school, he was sent to San Francisco. He was a bright student. Besides mathematics and science, he was well-versed in handling mechanical devices. For his adroitness, he was given charge of the scientific equipment in the school laboratory. He was paid $ 3 per month for his work.
Thereafter, he concentrated on the colours seen in a soap bubble. He studied the refraction in the surface area of the bubble. He explained that if the layer of soap film has half the wavelength of light, the two waves do not interfere and hence, do not get destroyed. Sir Isaac Newton too had studied the studied the colours in bubble. But he did not believe in the arguments regarding the wavelength of light, so could not put forth any explanation for it.
A mystery that puzzled scientists then was whether light waves need a medium to travel like sound waves. How does light travel from the Sun to the Earth? Scientists thought of a substance called ether, but were not sure about it. Michelson and his assistant Morley performed the experiment to test the ether hypothesis. At that time Michelson was professor of physics at the school of Applied Sciences in Cleveland. He later moved to Clarke University and in 1892 joined Chicago University as professor of physics and head of the department. Here, he could concentrate more on research, as his lectures were limited. He was a great disciplinarian. He always assessed his findings. Probably this could be the reason he could not mix freely with his students like Einstein or Fleming. But he had a tender heart and music was his only hobby. He was a good violinist and taught violin to two of his six children from two marriages.
The world of science always held Michelson in high esteem. Several institutions honoured him. He was honoured with the Nobel Prize for Physics in 1907, the first American to receive the award. Eleven universities all over the world conferred on him honorary doctorates. London’s Royal Society awarded him the Rumford Medal. He was also honoured with the Grand Prize in Paris and Exposition Prize in Rome. In 1892, the International Bureau for Weights and Measurements in Paris honoured him by awarding him an honorary Membership.
In 1926, Michelson performed a new experiment to measure the speed of light. In this experiment too he used Foucault’s principle of revolving mirrors. For this a special centre was set up on Mount Wilson in California. Exactly 22 miles, i.e. about 35 kms away on Mt San Antonio, another mirror was placed. Then light waves were sent from Mt Wilson. At the same time mirrors started revolving. The light wave traveled to Mt San Antonio, got reflected from the revolving mirrors and returned to Mt Wilson. During this period the mirror had completed a sixth of its revolution. Thus, he once again proved his technique to measure the speed of light. Michelson worked till his last breath. This great scientist died due to brain hemorrhage at the age of 79 on May 9, 1931.