• Benjamin Levy

The kilo is dead! Long live the kilo!

A change will take place on May 20th that will be incredibly dramatic and absolutely inconsequential for most people. The way we define a kilogram will change.

For most of us, this will have precisely ZERO impact on our lives. You will still weigh the same and the change does not mean that you don’t need to lose those two or three extra kilos you’re carrying around.

So, if for most practical purposes there’ll be no change, why is this important?

A story is attributed to Bertrand Russell that once he gave a lecture on the nature of the universe. Basic stuff: the Earth is a sphere orbiting the Sun (flat earthers, you can leave now), and we’re all part of the Milky Way galaxy and so on. At the end of the lecture someone in the audience challenged Russell, telling him that this was all rubbish and that the Earth was a flat disc sitting on the back of a giant turtle. To this the scientist asked what was the turtle sitting on and the response he received lives on as the meme that won’t die:

It’s turtles all the way down!

"It's turtles all the way down."

Until today, we had a turtles problem with the kilo. You probably defined a kilo as one notch on your bathroom scale. Congratulations, you found your first turtle. But what is that notch based on? Probably on some sort of calibration machine back at the factory that houses a chunk of metal that weighs, wait for it, a kilo! So, more turtles. And what is that kilo based on, another different kilo at some lab, that in turn is based on yet another chunk of metal held at your country’s authority for weights and measures, and so on and so forth until we get to THE turtle. An exquisitely machined chunk of metal housed under several glass isolation hoods in a climate controlled vault in Paris.

Under this scheme if that turtle changes in mass then the worldwide definition of a kilo changes as well. And since that original kilo must be used sometimes to calibrate other “kilos” it will be handled and exposed to changes in temperature and so on and so forth. For people that like precision this is an intolerable state of affairs.

Planck this is kilo, kilo, Planck.

There is something in physics called the Planck constant. It’s a measure of how the tiniest bits of matter release energy in quanta. Nothing is smaller than that and also, it’s a constant. It literally does not change.

So if there were turtles in reality, this one would be the one at the very heart of reality.

When combined with length and time we are able to use the Planck constant as the bedrock to define what a kilogram of mass is. But since we already have a kilogram around,what they did is define the Planck constant as a truly tiny portion of a kilogram. And by tiny I mean that the number is a zero followed by 33 zeros after the decimal point. after the decimal point.

You are wondering what all of this has to do with innovation. Well, too redefine what the Planck constant is first you have to measure it. Just how do you imagine that one goes about measuring the tiniest thing in the universe? Literally the tiniest thing in the universe.

Carefully as it turns out. And you’d need to invent all kinds of very fancy, very precise equipment and in the process advance science and engineering in ways that we cannot imagine now. So, stay tuned.

Ant-man in the Quantum Realm

There is, of course, another way to look at this whole Planck business. It is entirely possible that I might just be a huge fan of science on the one hand and of Ant-Man on the other. So that when Scott Lang takes the Avengers to the “quantum realm” to save the universe, he’s talking about going somewhere smaller than the quanta emitted in the Planck constant.

It turns out that to defeat Thanos you need to break the laws of the universe and I’m ok with that too.

Turtles all the way down

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