Butterflies, Motion, and the Relativity of Space — Part I

Galileo Galilei described an interesting situation, which possibly helped him develop his idea of  spacetime.   In brief, abbreviated (and slightly modified) form it goes something like this:  “Imagine you are in the main cabin below decks on some large ship, and having with you some  butterflies (in a bottle)…Let the ship proceed with any speed, […]