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by John Richards

Oh, how we all love certainty!

Ignorance is not bliss, it’s scary. The old adage has it wrong.  We need to know whether this snake, which we have never seen before, is poisonous or can be cooked and eaten. Doubt is discomforting.

The trouble is, we have never found anything in nature that is absolutely certain and we have been unable to make anything absolute. What do I mean?

Well, in science, we have something called ‘Absolute Zero’ temperature. Let me explain, heat is actually the vibration of particles. Hotter means more vibration, cooler means less. The idea is if we can cool everything down so far that the vibration stops, then that must be the lowest possible temperature. We can calculate it and have named it zero degrees Kelvin, after the great Scottish scientist (it’s equivalent to minus 273 degrees Celsius or Centigrade).

So, where is this coldest of all possible cold? It’s not space. Space is not uniform, but the average temperature is 3 degrees Kelvin; we call it the Cosmic Microwave Background Radiation, but that’s a story for another time. So, if it’s not ‘out-there’, can we make it here on Earth?

The answer is ‘no’, but not for lack of trying. NASA has a facility which investigates this extreme cold by actually trying to remove all the particles that might vibrate and producing a total vacuum. They spend a week pumping and refrigerating a chamber which has eight foot thick walls and still can’t get to ‘absolute’ zero (or absolute nothingness), although we can do rather better than space.

Absoluteness, certainty by another name, remains just a concept. It’s an idea that we can conceptualize in our brains. Inside our craniums, in the ‘Conceptual Realm’, anything is imaginable, including Humpty Dumpty. That’s very useful for making models, for making equations which closely match observations and enable us to understand nature better, but it’s not the same thing as the Natural Realm itself. It’s like a map, and it’s different from the territory.

We don’t even have absolute truth. To be absolutely true, a proposition must always be true and, in a universe that contains time, there is no always except, of course, in our heads. How long would be enough for some claim to be absolutely true? A century? A day? An hour? A second? You get the picture…

Relativity rules, ok!

Get used to it.