The scientific unit of beauty is the millihelen, defined as the amount of beauty required to launch one ship.
(The argument is that, if Helen of Troy had a face that launched 1,000 ships, a millihelen must be enough for one.)
The word is generally believed to have been coined by the science fiction author Isaac Asimov, though some give the credit to the Cambridge mathematician W.A.H. Rushton.
According to research at the Polytechnic University of Hong Kong, the best measurement of a woman's attractiveness is given by taking her volume in cubic metres and dividing it by the square of her height.
Sadly the researchers did not give any conversion formula between this measurement and the result in millihelens.
King Philip the Fair of France (1268-1314) had such high standards of beauty that he made skin diseases a punishable offence.
The first International Beauty Contest was held in Folkestone on 14 August 1908.
In 2006, when Miss Israel winner Yael Nezri was called up for national service in the Israeli army, she was exempted from carrying a rifle because it was liable to bruise her beauty queen legs.