
9 Amazing Science Gadgets - peter_d_sherman
https://www.youtube.com/watch?v=DC4uU_157oo
======
peter_d_sherman
The first gadget is by far the most important; it shows wave motion in two
dimensions, at a 90 degree angle, the first is vertical and shows
compression/expansion of the various wave constituent parts.

The other is horizontal, and shows the apparency of wave motion.

Observation: It should be possible to create spiral waves in space, using both
principles...

