Northwestern Physics Demos                                 Go back to Thermodynamics 
DCS# 4D30.10NWU# H30Location:    6 D 1
title: Radiation Pressure Pinwheel
aka: Crookes Radiometer

  Place a radiometer in front of an incadescent lamp to show spinning from un-even heating of the vanes of the radiometer.

   Which way should it spin?
    What happens if an IR filter is placed between the lamp and the radiometer?
     What happens if a very cold object is brought near the radiomter?
pix of lamp and radiometer