Using a 555 calculator, he designed a clock circuit that would run at 11.99 Hz ... enough to interface this with an oscillator, an IR LED, or a laser for long-range control.

[Danko]’s minimal circuit is about as small as possible for the DIP version of the venerable 555 chip. The BOM is stripped to the bone: just the chip, three resistors, a capacitor, and an LED.