Research into whether an empty beer bottle will do more damage to a human head than a full one took the 2009 igNobel Peace Prize, the second year in a row that it has gone to Switzerland. Stephan Bolliger of the University of Bern, Switzerland accepted the prize at the awards ceremony 1 October in the US.

and this year's other winners are....

Literature: the Irish Police for writing 50 speeding tickets to the most prolific offender in the country, Prawo Jazdy, whose name in Polish means "drivers licence".

Medicine: to Donald Unger, of Thousand Oaks, California, USA for research into the possible origins of arthritis by cracking the knuckles of his left hand for 60 years, but never the knuckles of his right hand.

Mathematics: to Gideon Gono, Governor of the Reserve Bank of Zimbabwe, for demonstrating that even common people can get used to the idea of dealing with a wide range of numbers, from the very small 1 cent coin to the extremely large Zim$ 100,000,000,000,000 (100 trillion) banknote.

Veterinary medicine: Catherine Douglas and Peter Rowlinson of Newcastle University, UK, for showing that cows with names give more milk than cows that are nameless.

Biology: Fumiaki Taguchi, Song Guofu and Zhang Guanglei of Kitasato University Graduate School of Medical Sciences in Sagamihara, Japan, for demonstrating that kitchen refuse can be reduced more than 90% in mass by using bacteria extracted from the faeces of giant pandas.

Physics: Katherine K Whitcome of the University of Cincinnati, Daniel E Lieberman of Harvard University and Liza J. Shapiro of the University of Texas, all in the US, for analytically determining why pregnant women do not tip over.

Chemistry: Javier Morales, Miguel Apatiga and Victor M Castano of Universidad Nacional Autonoma in Mexico, for creating diamonds from tequila.

Public Health: Elena N Bodnar, Raphael C Lee, and Sandra Marijan of Chicago, US, for inventing a bra that can be quickly converted into a pair of gas masks - one for the wearer and one to be given to a needy bystander.