Apple Seismology

Here is a cool 'Quick Study' about "apple seismology".

Quoting the article's lead: Just as an earthquake’s seismic waves reveal properties of Earth’s interior, elastic surface waves on an apple can tell us about what’s going on inside the fruit.

This research may be a contender for an Ig Nobel prize.

Update: Apple seismology was discussed originally in a 1973 mathematical modeling paper by J.R. Cooke and Richard Rand. (This paper is cited in the Physics Today article above.)