Interesting example of Aliasing

Aliasing occurs when your measurement frequency is not fast enough to accurately capture the measured event. In general, you want your measurement device to be one order of magnitude faster than the event being measured.

From Wikipedia: accessed January 9th 2011
"In signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable (or aliases of one another) when sampled. It also refers to the distortion or artifact that results when the signal reconstructed from samples is different from the original continuous signal."