Thirteenth-century theory described self-amplification of wind instruments

Evidence

When in wind instruments air escapes abruptly and violently [from the lips or reed], it collides with the tubular walls of these instruments, retraces its path, thrusts the air that it meets and receives impulses in return, pushing and being pushed back; spinning there in spiral fashion, from rebound to rebound under the force of the compressions and dilatations, it produces the notes, as they have said. — Eric J. Heller, Why You Hear What You Hear- An…, 530

Categorization

• QUESTION: Is Ṣafī al-Dīn’s ‘spiral fashion’ description an early intuition of turbulence/vorticity in the airstream, or just imagery? Worth chasing.
• SEED: Angle for an essay: the pre-modern acoustical intuitions of instrument makers and theorists that modern physics only later formalized.