Just a quick reminder that the equinox (autumn if you’re in the southern hemisphere, spring if you’re in the north) happens on 20 March in the Americas, and 21 March in the rest of the world. That’s the day you can help me to measure the size of the Earth, by doing a simple measurement!
See my post on Eratosthenes’ measurement for details!
Since it’s going to come up a lot and be a potential point of discussion on pretty much every post I make here, I’ve written a page (linked in the sidebar navigation) on The nature of proof. It discusses the semantics of what we mean by “proof” in a scientific context.
TL;DR: Each proof I post isn’t meant to be stand-alone, irrefutable, ironclad evidence of absolute truth that the Earth is a globe. What they are, are experiments and observations that are consistent with a spherical Earth, and more or less inconsistent with a straightforward Flat Earth model. You might be able to make them fit a Flat Earth model with some ad-hoc tweaking or conspiracy theories – but overall the spherical Earth model is a much simpler explanation.