Re: Heisenberg uncertainty principle for macroscopic objects

[Leigh Palmer <palmer@SFU.CA>]

> Well, without worrying about any of the niceties, the de Broglie
> wavelength of the elephant is surely extremely short

...and meaningless. The niceties are *very* important. Just because
you can plug the mass and velocity of an elephant into a formula
you should not conclude that you have inferred something physically
relevant by doing so. While buckyballs can be made to interfere
with one another or with themselves, elephants cannot. To do so an
elephant would have to remain in a coherent quantum state for a
period of duration at least as great as its length divided by the
speed of light.

We are always railing against the tendency of our students to take
any formula that seems to have the correct symbols and then to plug
in the data given (often with no attention paid to dimensions) to
obtain a numerical answer. That's just what you instantiate if you
perform this silly calculation.

It may be "fun" to do so, but don't do it, unless you disclaim the
result's meaning immediately afterward.

Leigh (the killjoy curmudgeon)