ALBERT EINSTEIN ( 1879 - 1955 )

ALBERT EINSTEIN ( 1879 - 1955 ) Einstein, one of the greatest physicists of all time, was born in Ulm, Germany. In 1905, he  published three path breaking papers. In the first paper, he  introduced the notation of light quanta ( now called photons) and used it to explain the features of photoelectric effect. In second paper, he developed a theory of Brownian motion, confirmed experimentally a few years later and provided a convincing evidence of the atomic picture of matter. The third paper gave birth to the special theory of relativity. In 1916, he  published the general theory of relativity. Some of Einstein,s most significant later contribution's are: the notion of stimulated emission introduced in an alternative derivation of Planck's black body radiation law, static model of the universe which started modern cosmology, quantum statistics of a gas of massive bosons, and a critical analysis of the foundations of quantum mechanics. In 1921, he was awarded the Nobel Prize in physics for his contribution to theoretical physics and the photoelectric effect. 

THOMAS YOUNG ( 1773 - 1829 )

THOMAS YOUNG ( 1773 - 1829 ) English physicist, physician and Egyptologist. Young worked on a wide variety of scientific problems, ranging from the structure of the eye and mechanism of vision to the decipherment of the Rosetta stone. He revived the wave theory of light and recognised that interference phenomena provide proof of the wave properties of light.

CHRISTIAAN HUYGENS ( 1629-1695 )

CHRISTIAAN HUYGENS ( 1629-1695 ) Dutch physicist, astronomer, mathematician and the founder of the wave theory of light. His book, Treatise on light, makes fascinating reading even today. He brilliantly explained the double refraction shown by the mineral calcite in this work in addition to reflection and refraction. He was the first to analyse circular and simple harmonic motion and designed and built improved clocks and telescopes. He discovered the true geometry of Saturn's rings.