Saturday, February 07, 2009

The Shadow of Schrödinger

Roy Simpson writes to me as follows:

The key questions here are twofold:

(a) Did Schrödinger's cat bring in voles?

(b) Will Shadow meet the same fate as Schrödinger's cat?

I answer as follows.

(a) Schrödinger's cat was confined in a 3D infinite square well, and had zero amplitude to be anywhere where voles tend to hang out. Shadow's Ψ function tends to diffuse towards voles ... and therein lies the difference!

(b) Schrödinger's cat was in a superposition of states, while Shadow prefers to be in his lowest energy stationary state. More technically, we should call it the duvet state.

One interesting attribute Shadow shares with other cats is a violation of Bohr's correspondence principle. As I go down the stairs first thing in the morning, Shadow exhibits profound non-locality in its position, managing simultaneously to be in front of me, behind me, and under my feet!