Erwin Schrödinger, born in Vienna in 1887, won the Nobel Prize for Physics in 1933 for an equation of wave mechanics which was fundamental to modern quantum theory.
In the hypothetical experiment devised in 1935, a cat is placed in a sealed box along with a radioactive sample, a Geiger counter and a bottle of poison. If the Geiger counter detects that the radioactive material has decayed, it will trigger the smashing of the bottle of poison and the cat will be killed.
The experiment was designed to illustrate the flaws of the ‘Copenhagen interpretation’ of quantum mechanics, which states that a particle exists in all states at once until observed. If the Copenhagen interpretation suggests the radioactive material can have simultaneously decayed and not decayed in the sealed environment, then it follows the cat too is both alive and dead until the box is opened.
Common sense tells us this is not the case, and Schrödinger used this to highlight the limits of the Copenhagen interpretation when applied to practical situations. The cat is actually either dead or alive, whether or not it has been observed.
“[It] prevents us from so naively accepting as valid a "blurred model" for representing reality,” Schrödinger wrote. “In itself, this would not embody anything unclear or contradictory.” Schrödinger’s Cat has been used to illustrate the differences between emerging theories in quantum mechanics, by testing how they would approach the experiment.
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For example, the ‘many worlds interpretation’, developed in the 1950s, would argue that when the box is opened, the observer and dead-and-alive cat split into two realities, in one of which the observer sees a dead cat and the other an alive one.
Work produced by Schrödinger and Einstein created "crisis of objectivity" is also connected to the realization that rationality, so prized from the Enlightenment through the era of the logical positivists, does not serve as a sufficient restraint on the technology unleashed by scientific knowledge. "In the eighteenth century, people had faith that the rationality of the scientist would in a way take the place of ethics, and give us values," philosopher Michael Friedman says. "But the destructive uses of science--for example, the use of technology in warfare--show us that it doesn't work that way. There's nothing inherent in science that forces it to be used for good ends, and in fact, the powers of technology can destroy the world. After all, it was Einstein's well-known formula, E = mc2 , that made it possible to develop atomic weapons."