What do Cats, Boxes, Schrodinger's Cat, and The Big Bang Theory Have in Common?
I just Googled cat in the box. I was looking for what I’m always looking for: pictures of fluffy kitties in fun cardboard boxes. What I got was a physics lesson.
Naturally, as a lover of cats in boxes, I was intrigued. Cats, boxes, and quantum physics? I must know more.
Many of us took physics in high school. High school physics is the kind of physics that explains why, when you toss a tiny rubber ball to your cat to play with her, it bounces. Quantum physics is not that kind of physics.
Quantum physics explains all the stuff that classic physics does not, like how light can be turned into electricity. Quantum physics deals with the tiniest things, subatomic particles, which behave in wacky ways. Physicists use mathematics to determine the likelihood that a subatomic particle is behaving in a particular way at a given point.
The Copenhagen Interpretation is an idea that a bunch of really smart physicists (including Albert Einstein) came up with that posits that – all mathematical calculations aside – until you can actually see for yourself where these crazy subatomic particles are, they must be thought to be simultaneously there and not there. What????
Physicist Erwin Schrödinger thought this was absolutely nuts. And to make a point about how absolutely nuts he thought the Copenhagen Interpretation was, he devised a “thought experiment” to point out the silliness of the idea.
A thought experiment is not a real experiment. Schrödinger’s thought experiment involved putting a cat in a metal box with some radioactive material, some poison gas, and a hammer.
Nobody, not Schrödinger, not anybody else, really put a real cat in a metal box with poison. No cats actually died in the name of quantum physics.
Schrödinger’s thought experiment involves a complicated made-up procedure in which the cat in the metal box could, at the end of the imaginary hour-long experiment, be just as easily dead as alive. Schrödinger says that the Cophenhagen Interpretation would suggest that until somebody opens the door to the metal box and sees the condition of the cat for himself, the cat is both dead AND alive. Sounds absurd, especially to a non-quantum physicist like me.
Still, it was a thought-provoking idea that got swept into popular culture. Writers such as Neil Gaiman in American Gods, and Terry Pratchett in Lords and Ladies, and John Green and David Levithan in Will Grayson, Will Grayson, made reference to the experiment. Numerous references can also be found in film (Repo Men to A Serious Man) and video games (Rock Band to BioShock 2).
Schrödinger’s Cat is a recurring theme in a very popular TV show, The Big Bang Theory. Character Sheldon initially uses it to explain to Penny that until she tries out a relationship with Leonard there is no way to know whether it will be good or bad (alive or dead). When Penny and Leonard finally kiss on their date she concludes, “The cat’s alive!”
I don’t know about your household, but the cats in our boxes are most definitely alive: playful, silly, and as outrageous as always. Oh, and completely unconcerned with quantum physics, just the way they should be.