Crookes Radiometer Spins in Light

Vanes spin faster in bright light. Ask students to predict what will happen. Move radiometer between dim and bright light. Key idea: Temperature differences around vanes and gas molecules create radiometric forces. Ask: Is light pushing the black side directly? Safety and cleanup: Glass toy teacher-handled. https://www.google.com/search?q=%22Crookes+Radiometer+Spins+in+Light%22+science+demonstration+experiment