Q.How will you prove that Earth itself is spinning?

The observation. Watching the night sky continuously for several hours (or using long-exposure photography) shows every star appears to trace a slow circular arc across the sky, all centred on one particular, nearly-stationary point.

The pole star. That fixed centre point is occupied by the pole star (Polaris), which happens to sit almost exactly above the Earth's own axis of rotation -- so, as the Earth spins, Polaris's position in the sky barely changes at all, while every other star appears to sweep around it in a circle over the course of the night. …