If you tap the top of a coffee cup with a spoon you will notice that the sound strongly depends on the where you tap. Knowing the cup geometry one can predict the frequency spectrum of the emitted sound when tapping at different points. Consider now the inverse problem and find an experimental technique to reconstruct the cup geometry from the emitted sound. What is the minimal knowledge about the cup geometry needed to make the problem solvable? https://youtu.be/MfzNJE4CK_s?t=333
