Designers of a bra that turns into gas masks and a team who found that named cows produce more milk were among the winners of the 2009 Ig Nobel prizes.
The aim of the awards is to honour achievements that "first make people laugh and then make them think".
The peace prize went to a Swiss research team who determined whether it is better to be hit over the head with a full or empty bottle of beer.
The full list of winners:
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.
Peace: Stephan Bolliger, Steffen Ross, Lars Oesterhelweg, Michael Thali and Beat Kneubuehl of the University of Bern, Switzerland, for determining whether it is better to be smashed over the head with a full bottle of beer or with an empty bottle.
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.
Medicine: Donald L Unger of Thousand Oaks, California, US, for investigating a possible cause of arthritis of the fingers, by diligently cracking the knuckles of his left hand but not his right hand every day for more than 60 years.
Economics: The directors, executives, and auditors of four Icelandic banks for demonstrating that tiny banks can be rapidly transformed into huge banks, and vice versa (and for demonstrating that similar things can be done to an entire national economy).
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.
Literature: Ireland's police service for writing and presenting more than 50 traffic tickets to the most frequent driving offender in the country - Prawo Jazdy - whose name in Polish means "Driving Licence".
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.
Mathematics: Gideon Gono, governor of Zimbabwe's Reserve Bank, for giving people a simple, everyday way to cope with a wide range of numbers by having his bank print notes with denominations ranging from one cent to one hundred trillion dollars.
Hat tip: Simon B