Show HN: Pi Explained Visually

I was recently thinking about defining things vs explaining them. When you're trying to understand something, I think it's easier to use a story like approach. "If you take the line making a circle (or circumference if you already know that one) and measure its length. Then you take the diameter…"

Once you know something, it's easier to shift that knowledge into a definition. "the ratio of a circle's diameter to its circumference." It's more concise and is more usable to tell subsequent stories and make subsequent definitions.

I think this might be a common mistake when explaining things. When we understand something, it's kind of stored as a stack of definitions. "Ratio between diameter and circumference" assumes the learner knows ratio, diameter and circumference. If they don't, the tendency is to build up their definitions. "Ratio is __. circumference is __. pi is__…" But definitions take a bit more effort to plug into your brain.

I think there's a programming paradigm analogy though I'm not quite fluent enough in the concepts to be confident about it. To venture.. a declarative programming's "Case Where" expression is more difficult to grasp than procedural "if then" if you're not familiar with conditionals in general.

I think this is why encyclopedias can be hard to understand. They kind of define things.

The best way I've seen pi explained visually is pi-unrolled.gif: https://commons.m.wikimedia.org/wiki/File:Pi-unrolled-720.gi...

Another approach: http://betterexplained.com/articles/prehistoric-calculus-dis...

This would be a great resource for an advanced second grader.

There are just definitons. Not interesting at all.