Why did Erwin Schrödinger choose a cat?

I’ll keep this short because it is not very interesting. Erwin Schrödinger was an Austrian Nobel Prize winning physicist. He is best known for what I will call a “theoretical experiment” concerning a cat.The experiment is also described as a “thought experiment”.

The experiment is news worthy because in celebration of Schrödinger’s birthday Google changed their fancy image on their search page to one that represented Schrödinger’s Cat. He would have been 126 years of age. Schrödinger  was born on 12 August 1887 and died on 4 January 1961.

This is the Google artwork:

Schrödinger’s Cat in the artwork is a tabby cat coming out of a box.

The experiment called “Schrödinger’s Cat” is almost impossible to describe unless you are a quantum physicist with a brain the size of a house so like other websites I’ll take the easy option and quote the man himself:

“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.”

“It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation.

That prevents us from so naively accepting as valid a “blurred model” for representing reality. In itself, it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks.”

Got it? No, nor me. Well, I have discovered that when Schrödinger was working as a Fellow at Oxford University in 1933 he lived with two women and his cat, Milton! Great. He kept a cat called Milton. His living arrangements were frowned upon by the university. I think they were referring to the two women, not his cat.

Schrödinger left Oxford and went to Princeton University in America. I have no idea what happened to Milton. I have a sneaking feeling that he stayed behind to be looked after by his women friends.

So in answer to the question in the title, he chose a cat because he had a cat companion. The experiment was rather gruesome though.