The phrase “Social Distancing” is the new normal in our present national challenge. Science tells us to keep six feet of distance between people until the fury has passed. In the U.S., Myanmar, and Liberia, we use “feet” everyday, because “feet” is a customary name of length measurement. However, in the rest of the world, where the unit “feet” is unknown, science is telling people to keep two “meters” apart.

I pray you are well and the angel of illness passes over your house. For my monthly epistle, here, I figured since life is slowing down for a few weeks, and we want to keep our minds sharp at home, we can have a chat about the world’s metric system. If you have a scorn or fear for metric but you want a little primer, then I’m offering a tutorial here. If not, then you’ll throw out my offer in 0.2 nanoseconds. I’m not here to preach we should overthrow the customary system of inches, feet, and pounds. Actually they work fine in our culture and there is no need to change. I just want you to have confidence when you see metric in your everyday world at the doctor’s office or grocery store. America is becoming bilingual, like it or not. With my tutorial, you will know the basic concepts. Just learn what you need.

We start with a review of three concepts you already know: dimensions, measurements, and units. Dimensions are ways to understand and describe the natural world when we try to explain length, time, mass (weight), volume, time and others. Another word for length is distance, so “social distance” we understand as the dimension of length, even before we talk about the amount of that distance.

Second, we want a measurement of that dimension to describe how much of that dimension we are talking about. “Six feet” is a measurement because it has a numerical component and it has a name that everyone understands. A measurement is really a numerical comparison of a dimension to a known standard that everyone understands.

Third, the name of the measurement is called a unit. Units are the “social” component of “social distance” because the speaker and the hearer know what the unit means. In our culture, everyone knows the customary unit of feet. It works, and there is no need to change that custom. The “six” is the amount, and “feet” is the unit; together “six feet” is called the measurement of the distance between people this spring.

These customary units developed when people used their body dimensions to explain comparisons using length, mass, and volume. It was the norm, and everyone understood. The British had hundreds of units that have now fallen away. We pragmatic Americans simply use what works. We all know an ounce of prevention is worth a pound of cure.

However, as more precise measurements were required during the ascension of science, French scientists devised a system of measurement based on factors of ten: 10, 100, and 1000. It simplified conversions and descriptions among the world’s languages. Scientists guessed the circumference around the earth and came up with one forty-millionth of the distance and called it a “meter” which means “measure.” That measurement, today, is about 39 inches (a yard stick plus about three inches). The system is called the metric system and dates to April 1795.

Here are basic metric units: for length, the meter; for mass (weight), the gram; for volume, the liter. There are other dimensions, but we’ll stay with these. These are names that, once learned, become social science language. These names are becoming more common every day. The other day I was in the doctor’s office and my height was recorded as 187 centimeters (cm) (6 ft. 2 in.) and my mass (weight) was 93 kilograms (kg) (205 pounds). At the grocery store, the twelve ounce beverage can has the label 354.9 milliliters (mL) underneath the amount of ounces.

The last topic, here, about the metric system are the prefixes in front of the units. You already know the prefixes from your computers: A thousand kilo-bytes equal 1 mega-byte; 1000 “mega-bytes” equal 1 giga-byte; 1000 giga-bytes equal I tera-byte. These are just conversions based on 1000 and they can be applied to the dimensions of length, mass, volume, and more. It’s easy. In length, one thousand meters are called a “kilometer.” Sometimes you hear about kilometers on highways. Ten kilometers is about six miles. In mass, one thousand grams are called a “kilogram” (at the doctors office), and in volume, one thousand liters is called a kiloliter. So, the prefix “kilo” is used in front of all metric dimensional base units to indicate one thousand of those units.

The same concept applies to smaller prefixes. You have heard of millimeters of mercury (mm of Hg) (air pressure in weather), milligrams of prescription medicine, and milliliters of soda pop. The prefix “milli” means one one-thousandth of the base unit. A dime is one millimeter thick, which means one thousand dimes stacked up would be one meter tall. That’s one hundred dollars, but who’s counting?

Now, how small is the coronavirus? One hundred nanometers, on average. Here are two more prefixes in the dimension of length: micrometer and nanometer. A millimeter is made up of one thousand micrometers, and a micrometer is made up of one thousand nanometers. Therefore, one million nanometers describes the width of a millimeter, a dime. The average diameter of the coronavirus is 100 nanometers. It is so small 10,000 of them in a group would be smaller than a grain of sand.

Such is the small, sinister enemy we are up against. Corona has no conscience; it seeks to reproduce and move on, leaving destroyed cells behind. We are in this fight together. We obey local civil and medical authorities because twenty-eight grams of prevention is worth 454 grams of cure. Thanks to the folks on the front lines of care.

The world is taking measure of our character as we balance public health versus economic need for work. Meanwhile we keep our minds sharp. We teach our children and grandchildren not to waste time. I hope this tutorial has helped pass the time. Keep your distance, but keep in touch.

John D. Griffith is a retired military chaplain and Christian Church minister and a graduate of the United States Guard Academy. He taught high school math and science at Great River Christian school for seven years, and presently serves in the Des Moines County Community Emergency Response Team (CERT). John also enjoys tutoring students and helping youth achieve their full potential.