… and someone is there to hear it, does it make a sound?
It does not, according to the high authority of Aristotle: “not all bodies can by impact on one another produce sound; impact on wool makes no sound, while the impact on bronze or any body which is smooth and hollow does” (De Anima, II.8).
Last night at a dinner party, the students in my De Anima seminar had the occasion to test that claim. Admittedly, the experiment was fraught with complications, which made its interpretation obscure. Instead of wool, we had the long fluffy hair sheared from my faithful golden doodle, Lulu: Was Aristotle’s claim meant to cover dog fleece as much as sheep fleece? That hair, too, had been slightly matted when I clipped it off, and afterwards it had been stored in a plastic bag for weeks (since I had absentmindedly forgotten to carry out the experiment, week after week), resulting in potentially even more matting, from the heat and residual moisture: So would the consequent clumpiness of the hair vitiate the results?
We carefully recorded (on an iPhone) the experiment: see the video below. Some observers claimed to have heard the “wool” producing a sound; others claimed that there was no sounding at all.
As the Magister presiding over the dispute, I saved both Aristotle’s authority and the appearances by means of an apt distinction: “the wool in the respect in which it was wool,” I declared, “indeed made no sound, but in the respect in which it was a clump, it sounded.”