From Peter Slessenger, Reading, Berkshire, UK
The thought experiment designed by Eugene Wigner describes a friend in a closed room who knows the state of a quantum particle, whereas the author doesn't. An analogous real-world experience is sending a letter to New Scientist, or some other equally august organ.
I know I've sent it off, and I get a reply to acknowledge receipt. But the wave function of whether my epistle is actually printed doesn't collapse (for me) until I open subsequent issues and see if it is indeed there.
