More evidence against flat earth: star trails

This is a follow-up to my post How we can know the earth is a ball without relying on modern science or traveling long distances?. It is well-known and easily observable by the naked eye (even by a single individual if they use modern travel) that the stars appear to rotate counterclockwise in the Northern…

A casual intro to topics in relativity

Special relativity is a theory of motion developed primarily by Albert Einstein in the early 20th century. Its precursor was Galilean relativity, which basically states that velocities are relative. One of the key features special relativity is the speed of light c being a constant. This means its speed is not relative, and this has…