An extended metaphor shining light on the problem of having to use humans in groups to agree on things that eventually need to be coded into a formal system.
Do you know about pi (π)? π is the ratio of a circle's circumference to its diameter. This ratio is the same for any circle. Pi is a neat little number most kids learn about in school. People have known about it for thousands of years, ever since we started drawing circles and doing math with them.
Here's a fun game: ask a friend what pi is. Some people will say "3". Many have learned that π is the ratio 22/7. Still others, probably the kids who think they're smart, will say "3.14". If you were to ever ask me, ever since I was a little kid, I'd tell you that it is "3.141592863". That's because I tend to be a pretentious jerk who found things like this impressive, but I only learned that about myself as I got older. At the time, I thought it was pretty cool to know that many digits. I have many friends that know π out to 10, 50, even 100 or more digits. What can I say? We usually had no problem picking up the girls at parties. It's a gift.
π is what's called an irrational number. Technically irrational numbers are those numbers which are not rational. (Mathematicians get paid for saying such things!) Rational numbers can be expressed as p/q, like 4/1, 2/3, or 19/28. You can also express any rational number as a couple of fractions banged together with an arithmetic operator, like 1/2 + 1/4, or 33/17 * 3/17, because math. If you can't express a number as a ratio of numbers, or a combination of ratios, then by definition it's not rational. It's still a number, or course, and it still exists on the number line. So where is it?