I have been introduced to a logic puzzle that was supposedly written by Albert Einstein. The version I originally read came from the Brain-Fun website. The story that goes along with the puzzle is that Einstein claimed only 2% of the population would be able to solve it. Some of the other people reading the […]

# Miscellany

## Signal Decomposition Using Farge Wavelet Method

Wavelet analysis is becoming ever more popular in plasma and fusion research, though the methods have been known and applied in other fields (such as image processing and the monitoring of electrical power systems) for some time. In 2006 the following paper detailed a method for separating a time signal into its coherent and noise […]

## Mean Free Path of Air

There is a simple approximation for the mean free path, λmfp, of particles in air at room temperature (T = 25 oC) given by, where λmfp is in units of centimeters and the pressure, P, is in units of Torr. While this is a commonly used approximation, it is not clear how it is derived. […]