The man who tried to explain some of the enigmas behind quantum mechanics has earned a Google Doogle.
Born on August 12, 1887, physicist Erwin Schrödinger won the 1933 Nobel prize in physics for his contributions to the often bewildering area of wave mechanics. But Schrödinger is probably best known for his weaving a tale about a theoretical cat in an attempt to describe the paradox of quantum physics.
The subject of a hypothetical experiment, Schrödinger's Cat finds itself cooped up in a box along with a small bit of radioactive material, a Geiger counter, and a flask of acid. If one of the atoms in the radioactive substance decays, a chain reaction is set off that releases the acid, thus killing the cat. But if the decay does not occur over a certain period of time, the cat lives.
Further interpretation of the experiment involves the observer. Until the box is opened, the observer doesn't know whether the cat is alive or dead, meaning theoretically that both states exist at the same time.
As Schrödinger himself described the experiment:
A cat is penned up in a steel chamber, along with the following device (which must be secured against direct interference by the cat): in a Geiger counter, there is a tiny bit of radioactive substance, so small, that perhaps in the course of the hour one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges and through a relay releases a hammer that shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The psi-function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal parts.
Schrödinger's poor cat experiment is typically used today as an example of the apparent contradictions in quantum mechanics. Just don't try it at home.