https://www2.math.upenn.edu/~kazdan/425S11/Drum-Gordon-Webb.pdf https://www2.math.upenn.edu/~kazdan/425S11/Drum-Gordon-Webb.... is a great paper on hearing the

https://www2.math.upenn.edu/~kazdan/425S11/Drum-Gordon-Webb.pdf https://www2.math.upenn.edu/~kazdan/425S11/Drum-Gordon-Webb.... is a great paper on hearing the shape of a drum Life at Low Reynolds Number makes you think of things which arent visible but move :https://www.damtp.cam.ac.uk/user/gold/pdfs/purcell.pdf https://www.damtp.cam.ac.uk/user/gold/pdfs/purcell.pdf There are more but lets see if the above two work for you first