Magic Balls

Magic Balls

Uri Lachish, Rehovoth

Left: Styrofoam ball.
Right: Ball's right coated with white paint; ball's left roughened with sanding paper

Electric bulb.                                     Enclosure for the bulb.

Left: Tennis ball
Right: Frosted plastic table-tennis ball. The right side is coated with white paint.


All the photos are flashed in the dark with a phone camera.

The full moon and the full earth, the "blue marble".


  1. Kopal, "An Introduction to the Study of the Moon", (Springer, 1966), p. 330
  2. Michael K. Shepard, "Introduction to Planetary Photometry", Contemporary Physics, 59(1):1-1 · October 2017, (Cambridge, 2017)
  3. Akkermans, E.; P. E. Wolf; R. Maynard; "Coherent Backscattering of Light by Disordered Media: Analysis of the Peak Line Shape". Physical Review Letters. 56 (14): 1471–1474 (1986)
  4. Diffuse reflection
  5. Coherent backscattering
  6. Oren–Nayar reflectance model

On the net: February 2022


                           One ball, a thousand theories. Seven balls even better.