This reminds me of something I observed with water. If you get a thin, smooth, and clear (no air bubbles) stream of water coming out of a faucet, you can put your finger into the stream and it will cause a disruption of the smooth flow of water up to an inch above your finger. It's subtle and you might have to look at it in the right lighting to notice. I guess it's not too surprising since the speed of sound through water is faster than the water is falling, so the waves are able to propagate up the falling stream.
> The ripples reduce the tension around the thumb, allowing the thumb to drop quickly, before the rear of the band reaches it.
I don't think you need ripples for this...? The tension on your thumb is plenty capable of pulling it out of the way of the oncoming rubber band. I assumed this was just part of elemental rubber band shooting technique.
I love that the article explains why it doesn't strike the thumb. Sometimes I am not fast enough and it does hit my thumb, which is why I opt for the method where you wind it around your thumb to create a trigger.
