Arnd Leike of the University of Munich was awarded the 2002 Ig Noble Physics prize for demonstrating that beer froth obeys the mathematical Law of Exponential Decay. [Reference “Demonstration of the Exponential Decay Law Using Beer Froth,” Arnd Leike, *European Journal of Physics*, vol. 23, January 2002, pp. 21-26.]

Since then, investigations into the decay of beer froth have continued – and one experimental research project in particular has challenged the idea that it decays exponentially. A team from the Institut für Angewandte und Physikalische Chemie–Arbeitsgruppe Chemische Synergetik, Universität Bremen, Germany, “call in question the results presented by Leike”, saying that :

“

It is our finding that the foam volume does not shrink simple exponentiallybut in terms of higher order according to the equation lnV(t) = a−bt −ct2.5 (3.1). The term ct2.5 describes the reorganisation of the bubble arrangements which will lead to an Apollonian gasket of bubbles. [our emphasis]”

in *Discrete Dynamics in Nature and Society, *Volume 2006, pp. 1–35, by S. SAUERBREI, E. C. Haß, AND P. J. PLATH.