All the fancy measuring devices used in science are based on two Stone Age technologies

Humans are animals That measures things. Contact us Homo minsura. We are hardwired to quantify, and for thousands of years we have been inventing new ways to do so. For anything you can think of, there’s a device to measure it — from sphygmomanometers to fluorescence spectrophotometers. Of course nowhere is this more true than in science. Well, science and baseball.

Physicists build models to explain how the world works. It may be an equation such as the ideal gas law: PV = nRT. This tells us, for example, that if you double the temperature of the gas (T), and all other factors are equal, the pressure of the gas (P) will double. But to know if the model is legitimate, or at least useful, we need to get some real-world values ​​and validate the equation. Modeling and measurement, measurement and modeling – that’s science in a nutshell.

Of course, today we have some great tools for this. But I’ll let you in on a little secret: With all our wonderful tools, measurement is still based on either comparison or counting. In this sense, not much has changed since Noah built his ark from a sheet of specifications with cubits, that is, the length of a human forearm from the elbow to the tip of the finger. Let me show you what I mean.

Length measurement

I’ll start with a measurement that everyone has used at some point: length or distance. It seems simple, right? If you want to know the length of a pencil, place it next to the ruler. There, 18.7 cm. (Yes, in science we are on Which side of the ruler.)

Photo: Rhett Allen

What you’re doing here is comparing the length of the pencil and the length of the ruler side by side. (Of course, this raises another issue: How do you know if the ruler you bought online is accurate? That’s a whole other discussion about standards. We can save that for another day.)

The most bizarre comparison of all was made in 1958 when a group of MIT students set out to find the length of a bridge over the Charles River. They had the shortest member of their group, Oliver Smoot (5′ 7′, or 170 centimeters), repeatedly lie down, marking the sidewalk with chalk, along the path, and found the bridge to be 364.4 smoots, “give or take an ear.”

(You can’t make this stuff up: Smoot became president of the American National Standards Institute and later the International Standards Organization. Smoot’s definition was revised in 2015, when photographic evidence revealed that his stature had diminished by 3 centimeters at age 75.)

However, measuring length or distance by comparison turns out to be the most common method used in analog devices.

Other distance measurements

For example, what about time? One of the oldest devices for measuring time is the sundial, which in its familiar form was invented by the ancient Greeks. It has a triangular blade called a hour handA flat dial with numbers around the perimeter of the watch.

Photo: Rhett Allen