250 Words on the Metric System

[NOTE: I scheduled this to run the week after the election some time ago because I figured something lighter than politics would be nice no matter which way it turned out. Today, I think that’s truer than ever.]

I’ve always admired the metric system, but didn’t feel entirely comfortable with it until I became a chemist and used it routinely. It is an objectively superior scheme of weights and measures with, in my opinion, one exception.

The strength of metric isn’t just how everything’s divisible by ten, although that’s convenient. Its real beauty is how it links length, volume and mass at its foundation.

One cubic centimeter of water—that is, 1 x 1 x 1 cm or 1 cc, a bit smaller than a sugar cube—equals 1 milliliter of volume and 1 gram of mass.

From that seed, everything blooms.

One liter of water measures 10 x 10 x 10 cm and weighs, by definition, 1 kilogram. Want to know how much your bucket of water weighs? Measure its volume. Want to know its volume? Measure its weight.

So elegant!

The one metric measurement I dislike is the Celsius temperature scale. Unlike the other metric measurements, it has no connection to length, mass or volume (nor could it). A scale defined by the freezing and boiling points of water is no more logical or useful than any other.

Also, the difference in temperature measured by one degree Celsius is equal to nearly two degrees Fahrenheit, meaning Fahrenheit has almost twice the precision of Celsius. For example, both 69 and 70 Fahrenheit round off to 21 Celsius, but I can feel the difference between 69 and 70. Fahrenheit is a scalpel while Celsius is a chainsaw.

Enjoy!