>[!abstract] >A friend of British philosopher and logician Ludwig Wittgenstein once saw him staring at the sky. > >When prompted why, Wittgenstein asked back: “Tell me, why did people use to think that the Sun went round the Earth, rather than that the Earth was rotating?” > >To which the friend replied, “Well, obviously, because it just looks that way. The Sun looks like it goes around the Earth.” > >Wittgenstein paused for a moment before responding, “Well, what would it have looked like if it was just the Earth rotating?”. >[!related] >- **North** (upstream): [[Heliocentrism]] >- **West** (similar): — >- **East** (different): — >- **South** (downstream): —