The Wave!

The wave is a common thing to do at baseball games-- people stand up and wave their arm and yell in a pattern around the stadium so it looks like a wave is going through the crowd. Physicists like it because they study electromagnetic waves. The wavelength (lambda) is the distance from trough to trough (or peak to peak). The velocity (m/s) is wavelength (m) * frequency (Hz= s^-1). The equation of a wave is sinusoidal: x=Acos(2*pi*f*t), where A is the amplitude (height from midline to peak or trough), f is frequency, t is time, and x is distance along the x axis.

The green bird is the Phillies' mascot, the Phillie Phanatic.