Nothing is colder. Not liquid helium, not hell (when it freezes over), not revenge served on a dish, and not even Frosty the Snowman (made from that special Christmas snow) - Nothing is colder than absolute zero. And what a great two word combination: Absolute Zero. It just curls off your tongue like mist on a morning pond.
So what is it? Well, absolute zero is a theoretical temperature. It is the temperature a substance would reach if it could actually obtain zero thermal energy. That is to say - no energy whatsoever. And that’s even less energy than I have when I first enter my work cubicle Monday mornings. The utter absence of energy.
Now as we know, temperature is a measure of molecular agitation. The higher the agitation, or the velocity of a substance’s molecules, the higher the temperature. So absolute zero would be the total non-movement of a substance’s molecules. This total non-movement, or absolute zero, is used as a fixed point in absolute temperature scales. It is 0 K (how far I jog every day), -459.67 F (my best grade in high school English) or -273.15 C depending on what scale you want to use.
But any way you measure it - absolute zero is frikin cold. Too cold for us to actually relate to in our relatively warm and cozy lives, including the lives of those crazy explorers to the Earth’s poles or the even crazier people who chop holes in frozen lakes and jump in for sport.
And now you may well ask - has any substance ever reached absolute zero? Not that we know of. The coldest temperature ever recorded was two-billionth of a degree above absolute zero. That is ( two times ten to the minus nine) degrees Kelvin. Close, but no frosty, unlit cigar. It was reached by the Low Temperature Laboratory team in the Helsinki University of Technology, Finland in October of 1989.
October 1989. The precise time I started my cubicle job. Coincidence or cosmic absolute?
Nothing is colder.
Nothing at all.