So often, when I'm

• watching TV;
• using my remote control to change TV channels or volume;
• using my computer;
• passing through a store-door opened electro-mechanically for me,

I whisper, "Thanks, Al!". I mean Albert Einstein (x-y), whose photo-electron effect formula taught engineers how to control all of these "slaves".

Physicists knew that light shining on metal in a vacuum tube could release electrons that flowed in a current to do work. But they long puzzled over the photo-electronic properties:

• At fixed frequency of light, the current (number of electrons knocked out of the metal) depended upon the intensity of the light -- a result explanable by the accepted wave theory of light.
• But, associated with each frequency was a threshold below which no current flower (no electrons knocked out), no matter what the intensity -- a result only explained by the Planck theory of quantization of energy.

This formula, involving the work-function for a given frequency, made it possible to control the flow of electrons through a vacuum tube onto a phosphorescent screen to create a TV or computer image. "Programmed" light from a remote control device so that it controlled the TV as to "channel", volume of sound, etc. Cause a broken light stream to allow a door to open.

These and other similar functions would require millions of human slaves to perform complementary work.

Thanks, Al, for giving us these electronic slaves and sparing the human ones!