FT267


The myth

Austrian physicist Erwin Schrödinger (1887–1961) proved that a cat in a box could be both alive and dead at the same time. This, in turn, proves that quantum physics is a load of nonsense peddled by madmen.


The “truth”

The reason the alive-and-dead cat sounds ridiculous is because it was meant to. Schrödinger’s 1935 thought experiment was intended to show what he considered to be the absurdity of a particular interpret­ation of quantum mechanics. He imagined shutting a live cat in a box containing what he called a “diabolical mechanism”, which, depending on an event that can’t be predicted, would either kill or not kill the animal. If the theory accepted by most of his colleagues were taken to its logical conclusion, the cat would at some point be neither wholly alive nor wholly dead – and would only become either alive or dead at the moment that an observer looked inside the box. This, Schrödinger pointed out, was just plain silly, and therefore the theory must be incomplete. But Schrödinger is – like countless satirists before and since – a victim of his own success. Generations of theoretical physicists have proposed resolutions to his paradox, while popular culture continues to take it at face value. Erwin may (or may not) be spinning in his grave.


Sources

Jim Al-Khalili: Quantum, Weidenfeld, 2003
JP McEvoy & Oscar Zarate: Quantum Theory For Beginners, Icon, 1996


Disclaimer

The great thing about not understanding quantum theory is knowing that this puts you in the company of Nobel-winning physicists; although it’s probably fair to say that they don’t understand it rather better than I don’t understand it. Anyone able to clarify the matter of the imaginary cat is welcome to do so via the letters page.