Cold? There is no such thing!

Our today's contribution from the column:
Did you know?
There is no such thing as cold!
You think, according to the date of publication, it's April fools?
We take this funny stuff seriously!
According to their definition Physicists in thermodynamics don't know cold, but only heat.
Heat is a form of energy and is sometimes present in large and sometimes only in very small quantities.

A common temperature classification in most of Europe, named after the Swedish astronomer Anders Celsius, is based on water, whose phase transition from solid to liquid is at zero degrees C, and which has its boiling point at 100, more or less accurately, depending on the boundary conditions.
Daniel Gabriel Fahrenheit, on the other hand, chose "his" lower fixed point (= 0 °F) according to the lowest temperature measured up to that time, which he was able to generate in Gdansk / Danzig, where he was born, which corresponds to -17.78 °C.
So that's not particularly warm, but it could be even less warm.
That's why physicists use a scale that owes its name to a Lord Kelvin, in which "zero Kelvin" marks the absolute zero point of temperature and thus knows no minus minus, no negative values.
Even "less warm" than zero Kelvin or -273.15 °C or -459.67 °F is physically impossible.
After all, temperature changes in Kelvin equal to those in Celsius, the value remains the same.
With Fahrenheit, you have to do the math, that is, take the value times nine, divide by five, and then add 32 to that.

The concept of "cold" as the opposite or relative absence of heat nevertheless exists in technical terminology. "king of cold" Carl von Linde introduced the first successful refrigeration machine to the market.
And in the case of heat pumps, which are based on the same physical principles, fortunately, there are systems that, if necessary, allow the heat pump to do its work ni esrever edom , and then chill a building, that is, to produce there what actually does not exist: Cold.