https://matteocampagna.com/en/registry/equipment/archers-paradox-arrow-flexes 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/archers-paradox-arrow-flexesThe shaft does flex as it leaves the bow, and that is no longer an inference from the laboratory. High-speed films of 16 world-level archers show the string driving the nock 13 mm towards the body in just over five milliseconds, after which the shaft straightens again before it passes the riser. The pressure button, the lateral support the arrow rests against at full draw, lets go of it within 8 ms, while the string releases it only at 14.6 ms: by the time the tail reaches the riser the arrow is no longer resting on anything and passes without touching it. Films of a Polish national-team archer, twenty years earlier, give the same picture, and an accelerometer mounted on the bow of an Italian national-team archer describes the same sequence from the other end, that is from the force the shaft unloads into the bow. No study in the bibliography points the other way, and on the bench the arrow flexes even when a machine does the shooting, so the flexing is not a fault of the release. Two independent models also give the condition for the shaft to pass without touching: it has to complete a full cycle of vibration while still on the string, and that depends on spine. Two limits remain: the shaft snaking around the riser without touching it is predicted by the models rather than filmed, and the figures hold for the finger release, since with a compound bow and a mechanical release the flexing drops to a few millimetres.claim:paradosso-arciere-flessione:revision:2026-10-15:4Thu, 15 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/archers-paradox-arrow-flexes#storiaThe flexible arrow model is applied to the vertical plane and finds flexing about ten times smaller than in the horizontal; in the paper test with a shooting machine, from 0.8 to 12 metres, point and vanes pass less than a millimetre apart vertically. It confirms that the paradox is played out in the horizontal plane, the plane of the riser, and the status stays corroborated.claim:paradosso-arciere-flessione:history_entry:2026-10-14:2013Wed, 14 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/archers-paradox-arrow-flexes#storiaA review chapter by the author of the 1997 model sets the calculated flexing against the flexing filmed in 1990 once more, up to the moment the nock passes the grip, and the agreement is still graphical. No new measurements arrive, and nobody has yet measured the flexing on more than one archer: reported.claim:paradosso-arciere-flessione:history_entry:2026-10-14:2007Wed, 14 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/archers-paradox-arrow-flexes#storiaA model treating the shaft as a vibrating beam, pushed by the string and held by the button, reproduces the shapes filmed on the Polish archer, and at ten and twelve milliseconds reproduces them better than the model that came with them: the arrow bends three times before the nock passes the button, and the last bend helps the vanes clear the bow. It leaves the string just as the nock crosses back over the plane of the bow, and a weaker shaft ends up against the button. The comparison with the films is by eye only, and the measurement is still that of one archer: reported.claim:paradosso-arciere-flessione:history_entry:2026-10-14:1997Wed, 14 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/archers-paradox-arrow-flexes#storiaAutomatic analysis of high-speed images puts a figure on the flexing that survives into flight, about seventy-five hertz on X10 shafts shot by a robot. Context that confirms, without shifting the status.claim:paradosso-arciere-flessione:status_change:2026-10-12:corroboratoMon, 12 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/archers-paradox-arrow-flexesclaim:paradosso-arciere-flessione:new_claim:2026-10-10:riportatoSat, 10 Oct 2026 08:00:00 GMT