The September stories at the main Flying Circus of Physics web site: (1) Vortex rings, from the smoke rings of a hookah smoker to the vortex rings shot from air cannons, powerful enough to knock down a brick wall. (2) Making music form those rude flatulence sounds produced with two hands or with one hand and an armpit. (3) Pub trick of the month: Making a coin rattle on top a beer bottle with touching the coin or bottle. (4) The bright spot (Poisson spot) that appears at the center of the shadow of a solid ball. (5) My old article about how to make things disappear like the Cheshire cat in Alice’s Adventures in Wonderland.

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