Okay, so something I really want to know is how do we know the circumference of the Earth?
And not just today: Granted, I don't know that either, but historically when we didn't have the science that we have today, like, how did we know.
To get to the bottom of this Joss and I are going to recreate an ancient calculation from our two distant points on the globe.
This calculation was first attempted thousands of years ago, and they got impressively close, maybe within a few percentage points.
But here at Howtown, we want to get way more precise than that.
We want to know how modern scientists got to this exact number.
And while we're at it, why is it so close to an even 40,000 km?
To answer these questions, we have to confront a fact that's frustrated people for centuries.
The Earth isn't actually a sphere.
The first good estimate of Earth size came from the guy credited with creating this map, Eratosthenes.
