If the temperature today is zero degrees and tomorrow the temperature is going to be twice as warm, how warm will it be?
The Fahrenheit and Celsius temperature scales are “relative” temperature scales, in that they are both relative to a couple of specific temperatures, namely the freezing and boiling points of water.
Let’s make the question a little more specific: “What is the temperature if it’s twice as warm as 0 degrees Celsius (the freezing point of water)?”
To answer this question we need to convert this Celsius temperature to an “absolute” temperature scale, a scale with no negative temperatures. We’ll use the Kelvin scale. 0 degrees Kelvin is the point at which all motion in matter stops; it is known as “absolute zero”. No temperature can exist that is lower than 0 degrees Kelvin. The formula to convert from Celsius to Kelvin temperature is:
K = C + 273.15
Where K is the Kelvin temperature and C is the Celsius temperature.
So 0 degrees Celsius is equal to 273.15 degrees Kelvin. We can double this number to get 546.30, the temperature that is twice as warm as 0 degrees Celsius. We can then subtract 273.15 from our answer to convert it back to the Celsius scale.
The temperature is 273.15 degrees Celsius when it is twice as warm as 0 degrees Celsius.