Science toys – Richard Jones

    • Richard Jones gave an entertaining demonstration of a number of physics toys.

These comprised:

  • Crookes’ radiometeran apparent perpetual motion machine, but actually dependent on radiant energy. Originally designed by Crookes to demonstrate differential radiation pressure between black & silvered surfaces, it actually rotates in the opposite direction because dominant effect is differential heating of residual air molecules on each side of a vane (

Crookes radiometer

  • Optical corner reflectorhow to see yourself as others see you!

  • Spinning hard-boiled & fresh eggseffect of internal fluid rotation on angular momentum

  • Super-magnet: picking up spent match, also demonstrating diamagnetism using a grape torsion balance

  • Donald Rintoul also demonstrated a Stirling engine which he had brought along, and which could be driven by placing over a cup of hot water, or even using hand heat.