Model the effect of the atmosphere
and/or interstellar medium on star light by directing the laser
beam over a hot plate onto a screen. The fluctuating refractive
index of the moving hot air will cause the spot of light on the screen
to move around. Use the beam expander to model light from a
planet for which, with its larger diameter, the twinkling is less
apparent.
A small aperture beyond the hot
plate can be used to represent the eye's iris, and a large aperture a
telescope objective.
