I have a friend that is a Phd candidate at the University of Utah. He teaches physics/math/cosmology at the state prison from time to time. He says that inmates

I have a friend that is a Phd candidate at the University of Utah. He teaches physics/math/cosmology at the state prison from time to time. He says that inmates are far-and-away the best audiences he has ever taught to! They are a "captive" audience! Couldn't resist :)