"Master, you used the term 'Eratosthenes proof' [164], what did you mean by that?"
"Well, if you 'suppose' you are on a globe and you design a system for measuring its diameter, the actual finding of 'a' value, a diameter, need not be strictest proof for your theory, but it certainly makes your sphericalogy into a giant likelihood. This is what Eratosthenes did. Knowing that on a certain date (a Solstice), a certain collumn threw no shadow, or a certain well had its bottom lit up in Assuan (roughly 23 degrees North) and at noon. All he had to do was to measure the angle of the Sun's rays at noon, some distance to the North of Assuan, at Alexandria, where the 'noon' was approximately the same. Then it was possible to calculate how many times the circumference of the Earth was this distance, namely the same as the number of times the 360 degrees agreed with the angle found. A flat Earth would not have given a value at all. It is fundamental for ideation, for Think, first to have a hunch, a theory AND then test it. It makes the difference between unproven-, untested-, untried-, superstition and quite a good theory." [164]