Erwin SchroedingerAustrian physicist with strong philosophical and poetical tendencies; he is best known as the founder of the wave equation of quantum mechanics, which is expressed beautifully as
(ih/2π)(∂Ψ/∂t) = HΨ.
The equation was presented and developed in a series of papers in Annalen der Physik in 1926. The physicists of Copenhagen did not like Schroedinger's idea; when Schroedinger visited Copenhagen, Bohr kept arguing with him several days, even at Schroedinger's bedside when the latter got ill by catching a cold.
Later, in 1935, he presented sharply a basic problem for interpreting quantum mechanics, in terms of "Schroedinger's Cat". The indeterminacy of a micro-state can be amplified by inserting an appropriate physical device, so that we can obtain a "mixed state" so to speak of "live or dead" of a poor cat confined to a box; but of course, when we see the cat, it is either alive or dead. Then what is the state of the cat when we do not open the box and still do not see its state? This became one of the favorite examples for illustrating the problems quantum mechanics poses.
[In what state is the cat, when the wave function has not collapsed by observation?]
Later, Schroedinger contributed to the development of molecular biology, by his book What is Life? written during the war in Dublin.
