Séance Séminaire

Séminaire de Probabilités et Statistique

lundi 26 mars 2007 à 10:30 - Amphi Saint Priest (près du LIRMM)

Persi Diaconis (Univ Stanford USA, Univ Nice et CNRS)

"Dynamical Bias in a Coin Flip"

I will show how in joint work with Richard Montgomery and Susan Holmes, we analyzed the natural process of flipping a coin which is caught in the hand. We prove that vigorously-flipped coins are biased to come up the same way they started. The amount of bias depends on a single parameter, the angle between the normal to the coin and the angular momentum vector. Measurements of this parameter based on high-speed photography are reported. For natural flips, the chance of coming up as started is about .51. Pour l'accès, cliquer ici