Arnold’s tongue fascination continues. It’s known as stick-slip oscillation and just like the name says, it’s extremely useful in studies of friction.
Think: stopping your car on a road with an unknown film on it. Is the film water? Is it oil? Is it some kind of random goo?
What about the brakes themselves? Are they wet? Will they grip or will they slip? If they slip, they aren’t stopping you.
What makes a door squeak? stick-slip music. Throw some WD-40 in there (alcohol + mineral oil basically – the mineral spirits help get the mineral oil deep into the cracks and then evaporate, leaving just the mineral oil behind) – and the squeaking music stops.
My ongoing fascination with the ‘gap’ (between chaos and order, music and noise (there’s no such thing as noise) and silence, continues).