Albert Einstein (1879-1955) was a German, Jewish mathematician and physicist. He is best known for his theory of special relativity, his mass energy equation (E=MC2) and his translation of Planck’s notion that light is emitted in quanta to photons.
Einstein’s special relativity theory reconciled mechanics to electromagnetism and his general relativity theory improved on Newton’s gravitation theory.
Einstein made other contributions to physics but his special and general relativity and studies on light are considered his seminal contributions to science.
Upon leaving college, Einstein worked at a Zurich Patents’ office. While there he had time to study what was dear to his hearth, light and gravitation, and in 1905 published four papers that have changed the world.
The first paper showed that light is in particles, photons. This idea was originated by Max Planck. The idea seemed to contradict the then current idea that light was in waves. Later observers eventually reconciled the particular and wave functions of light; at present it is accepted that light has wave-particle duality (Quantum Mechanics).
The second paper proved the atomic theory by showing random movements of small objects.
The third paper dealt with electromagnetism and introduced Einstein’s special relativity theory. It showed that the observed seeming independence of the speed of light from the observer’s stand point is not quiet so. It pointed out that space-time of moving objects slows down and contracts relative to the frame of the observer. This paper also refuted James Clerk Maxell’s postulation that there needs to be a luminiferous aether to act as a medium for electromagnetism to travel through space.
The forth paper pointed out the equivalence of matter and energy; it showed how matter could be converted to energy (hence the famous E=MC2 equation).
Einstein later wrote a paper on general relativity. This 1915 paper points out that gravitation is a distortion of space-time by matter, affecting the inertial motion of matter.
Einstein explained why the sky is blue, attributing it to the effect of accumulated scattered molecules of light in the atmosphere.
For his special and general relativity work and on the particular nature of light, Einstein was awarded the 1921 Nobel Prize in physics.
Thereafter, he collaborated with other physicists, such as Neils Bohr, in expanding our understanding of quantum mechanics.
He devoted the final years of his life trying to construct a mathematical unified theory of everything, a theory that unifies the four known forces of nature: electromagnetic, gravitational, strong and weak nuclear forces. He did not succeed. Some are still pursuing that Holy Grail.
Super strings hypothesis made a flash in that direction and is at the moment in limbo.
It should be noted that Einstein did not quite accept Bohr’s interpretation of quantum mechanics, especially its probabilistic view of the behavior of particles. If Bohr and Heisenberg’s indeterminacy hypotheses were correct, it seemed to Einstein that the universe is a random place without any kind of order to it, and he would rather believe that there is some sort of order and designer of that order (God, though not the Christian God, perhaps, Spinoza’s pantheistic God). God does not play dice, Einstein observed.
Einstein helped to persuade President Franklyn Delano Roosevelt to embark on building atomic bombs, in light of Hitler’s efforts in that direction. The Manhattan Project produced the first nuclear weapons, those dropped on Nagasaki and Hiroshima.
Einstein made seminal contributions to physics and arguably changed the face of physics since Isaac Newton.
Whether his contribution is more than those of quantum mechanics, such as Planck, Rutherford, Bohr, Heisenberg, Pauli and Schrodinger, remains to be seen. What is evident is that in popular imagination Einstein is the picture of genius.
Albert Einstein. On the Electrodynamics of Moving Bodies. (1905)
Albert Einstein. On a Heuristic Viewpoint Concerning the Production and Transformation of Matter. (1905)
Albert Einstein. On the Motion- Required by the Molecular Kinetic Theory of Heat-of Small Particles Suspended in a Stationary Liquid. (1905)
Albert Einstein. Does the Inertia of a Body Depend Upon Its Energy Content. (1905).
(These four papers constitute Einstein’s so-called Annus Mirabilis, the four papers that changed the face of science.)