https://matteocampagna.com/en/registry/equipment/air-damping-arrow-oscillation Changes to this claim in Matteo Campagna's evidence registry: its status, its year-by-year history, revisions of the page. en-gb https://matteocampagna.com/en/registry/equipment/air-damping-arrow-oscillationThe measurement comes from a single Japanese group, which set A/C/E arrows oscillating while suspended in a magnetic suspension wind tunnel, at 16 metres per second with an amplitude of half a degree and a frequency of 5 hertz. The damping coefficient comes out negative, so the air would tend to amplify the oscillation rather than kill it, but it is so small, a term of the order of one millionth, that the authors leave it out of their calculations. The result was published twice, in 2015 and 2016, with two types of vane, but these are the same tests and they count once. In the same work, though, the flight calculation made without that term shows the oscillation dying away anyway, almost entirely in the vertical plane, and in the model the only forces at work apart from weight are those of the air; a 2025 simulation links the fading to the moment that realigns the arrow with the flow and to the movement of the centre of pressure. An Australian model from 2011, checked against paper tests, had reached the same point from another direction: in flight the oscillation about the centre of mass dies away with a time constant of about 0.34 seconds, and what decides it is mainly the lift of the fletching. The reading is therefore a narrow one: what is negligible is the damping term measured in the tunnel, not the effect of the air on the oscillation in flight, which works another way. There is no independent measurement of the damping term in a tunnel.claim:smorzamento-aerodinamico-trascurabile:revision:2026-05-09:2Sat, 09 May 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/air-damping-arrow-oscillationclaim:smorzamento-aerodinamico-trascurabile:new_claim:2026-03-26:riportatoThu, 26 Mar 2026 08:00:00 GMT