Humble Pi: A Comedy of Maths Errors

by Matt Parker

The Celsius scale began around the same time, with Swedish astronomer Anders Celsius, except he counted the wrong way. Celsius started with zero as the boiling point of water at normal atmospheric pressure then counted up as the temperature went down, with water eventually freezing at 100°C. Meanwhile, other people went with the more popular convention of starting with zero at water’s freezing point and counting up to a hundred as its boiling point, and then they all argued over who had the idea first. There was no clear winner as to whose idea it was, but the unit itself caught on and was give the neutral name Centigrade. Celsius had the last laugh, however, when the name Centigrade clashed with a unit for measuring angles (a centigrade, or gradian, is one four-hundredth of a circle) so, in 1948, it was named after him after all. Celsius is now used almost universally to measure temperature, except seemingly in a few countries which still use Fahrenheit, like Belize, Myanmar, the US and a decent section of the English population who are ‘too old to change now’ (even though the UK has tried to be metric for about half a century).