celsius

[food_techie]

What is the diference between celsius and centigrade? What is centigrade and why are both words sometimes used? Do they mean the same thing?

[Hammer]

They are the same. Water freezes at 0 deg and boils at 100 deg. Centrigrade derives its name from the fact that there are 100 degrees between the melting and boiling points of water, Celsius is the bloke that invented it.

(insert discussion about altitudes, pressures, the fact that freezing point used to be 100 and boiling point 0, etc etc here)

[jake-the-peg]

I thought this had been asked recently but I can't find it so maybe I'm going mad.

Celsius is based on the triple point of water which is the unique combination of temperature and pressure where solid, liquid and gas co-exist - this helps in calibration of sensitive devices as you don't have to worry about what "atmospheric pressure" and as the difference is a fraction of a degree they're interchangable in everyday life.

There's a nice explanation here:

http://www.sizes.com/units/temperature_centigrade.htm

[food_techie]

Thanks for your answers.

[kempie]

Technically any metric unit could be described as 'centigrade' therefore using Celsius for temperature does away with any possible confusion.

[jonskinner]

http://www.infoplease.com/ce6/sci/A0811058.html

Try this website. Fromy my knowledge they're one and the same thing. seems to say that above as well.

[JohnDTC]

the celsius scale in practical terms is the same as the centigrade scale (which is a term not used in science anymore to avoid confusion). However, the celsius scale is derived from the absolute temperature scale, as the temperature in kelvin -273 (-273.15 to be exact).

the older centigrade scale was derived from the ice-point of water, which is less accurate for various reasons, than the triple point method used to determine the kelvin scale -from which the modern celsius scale is ultimately derived. the kelvin scale is also the standard temperature scale used in most physics equations.