Wednesday, May 17, 2006

An intuitive explanation of uncertainty principles

In his talk today on diabolical points (which arise as conical intersections in, for example, crossings of atomic energy levels), Sir Michael Berry had reason to briefly give an intuition explanation of uncertainity. The physical problem in question had to do with a situation in which approximating a wave by a ray (that is, doing semiclassics) does not let one address a certain phenomen in optics. A ray is infinitely thin, and for the phenomenon in question, it is essential to consider the oscillations and spread of the wave. One has an uncertainty principle in terms of measuring angular spread versus another quantity (which may have been amplitude). To help us understand things intuitively, Berry told us about how his mother was a dresser and that at the time women wore coarsets. He then proceeded with an uncertainty principle involving "squeezing." I was extremely amused, although I won't be giving this example in any quantum mechanics courses I teach.

Other stuff:

I had a picture of me taken in front of a Freemason lodge (where the Masons run free just like the buffalo).

My plane from Atlanta was delayed for an hour. The Delta people assured us that the plane had "no physical problems," so I can only assume that it's problems were emotional.

My mind is telling me that there is one more thing I forgot to mention, but it's not occurring to me now, so I'll blog about it later if it comes to mind.

No comments: