## How Can It Get Colder Than Zero?

The problem is people regularly think 20&#176F is twice as warm as 10&#176F! Everything we’re taught about math says it should be, but it’s not.

When I went to sleep last night it was 4&#176. We ended up bottoming out at around -4&#176. It was extremely cold, though the numbers are misleading or at least overstate the case.

Sit down. I hate to tell you this. There’s really little scientific significance to 0&#176 Fahrenheit! It was just a very cold temperature which could be produced reasonably consistently with the tools available 400 years ago. It is not where temperature stops!

From Wikipedia: According to an article Fahrenheit wrote in 1724, he based his scale on two reference points of temperature. The zero point is determined by placing the thermometer in brine: he used a mixture of ice, water, and ammonium chloride, a salt. This is a frigorific mixture which automatically stabilizes its temperature at 0 °F.

The second point, 100 degrees, was the level of the liquid in the thermometer when held in the mouth or under the armpit of his wife.

The problem is people regularly think 20&#176F is twice as warm as 10&#176F! Everything we’re taught about math says it should be, but it’s not.

There is an absolute point where the downward scale of temperature stops. It’s called “absolute zero” and it corresponds to -459.67&#176 Fahrenheit, -273.15&#176 Centigrade or 0&#176 Kelvin. At that temperature all molecular motion ceases!

Absolute zero doesn’t naturally exist though scientists have managed to approach it. They’ve never reached it. It’s possible they never will.

Last night we weren’t even close!