### Happy Flat Earth day!

As I write this, it is still March 14 where I am, which is of course celebrated by many as pi day.

The popular media in their explanations of the significance of pi, often presents it as being the ratio of the circumference to the diameter of a circle. This is claimed to apply to circles of any size, whether they be the size of atoms or galaxies, or anything in between. Not only is this almost always presented without any caveats, it's even emphasized to be universally true.

Let's take a look what this really means. First, we need to define what a circle is, and it's simply the set of all points in a two-dimensional space that are an equal distance from some centre. Twice that distance is of course the diameter. If you take a piece of rope and tie one end down, pull the rope taut, then walk around keeping it taut, the rope guides you along a circle, eventually leading you back to the point you started at.

Twice the length of rope is of course the diameter. So, how far did you walk?

If your answer, as all the pi day hype celebrates, is pi times the diameter, then you've just passed the admission test for the flat earth society!

Ask a round-earther this question, and they may hand you a rope that reaches from Santa's Workshop to Singapore. By the time you're done walking, you would have supposedly walked (plus swam where you couldn't walk... and yes, the rope floats) a circumference four times the length of the rope, or twice the diameter. But of course we're told over and over the circumference is pi times the diameter not twice, so clearly something's wrong with the round-earthers, right?

It must be a conspiracy.

Now excuse me while I go celebrate the day by eating a pie. From McDonald's.

The popular media in their explanations of the significance of pi, often presents it as being the ratio of the circumference to the diameter of a circle. This is claimed to apply to circles of any size, whether they be the size of atoms or galaxies, or anything in between. Not only is this almost always presented without any caveats, it's even emphasized to be universally true.

Let's take a look what this really means. First, we need to define what a circle is, and it's simply the set of all points in a two-dimensional space that are an equal distance from some centre. Twice that distance is of course the diameter. If you take a piece of rope and tie one end down, pull the rope taut, then walk around keeping it taut, the rope guides you along a circle, eventually leading you back to the point you started at.

Twice the length of rope is of course the diameter. So, how far did you walk?

If your answer, as all the pi day hype celebrates, is pi times the diameter, then you've just passed the admission test for the flat earth society!

Ask a round-earther this question, and they may hand you a rope that reaches from Santa's Workshop to Singapore. By the time you're done walking, you would have supposedly walked (plus swam where you couldn't walk... and yes, the rope floats) a circumference four times the length of the rope, or twice the diameter. But of course we're told over and over the circumference is pi times the diameter not twice, so clearly something's wrong with the round-earthers, right?

It must be a conspiracy.

Now excuse me while I go celebrate the day by eating a pie. From McDonald's.