In 1714, the Dutchman Warren Hite developed the Fahrenheit scale. He set the temperature at which a certain concentration of brine was solidified to 0 °F, the temperature at which the pure water was solidified to 32 °F, and the temperature at which the standard atmospheric pressure boiled was set to 212 °F, the middle is divided into 180 equal parts, each aliquot represents 1 degree, this is the Fahrenheit temperature scale, denoted by the symbol F, which is the Fahrenheit temperature
The Celsius temperature scale is the two fixed points of the temperature scale with the boiling point of water (the equilibrium temperature between water and water vapor at standard atmospheric pressure) being 100 degrees and the freezing point (the equilibrium temperature between ice and air saturated with water at standard atmospheric pressure) is zero. The difference in height between the boiling point of water and the point of freezing is divided into 100 grids, and 1 grid corresponds to 1 degree.
The difference between the two temperature scales is that the temperature variation per unit length is different, and the definition of the initial temperature of the same thing is different.
Celsius = (Fahrenheit – 32) ÷ 1.8 = (-40-32) / 1.8 = -40 degrees Celsius, so it is the same, this temperature is special