If there's no atmosphere in space shielding from particles, why is not dangerous for spaceships/humans?
Some time ago I was thinking about this. We know that space is almost matter-free, and also is plenty of particles and objects orbiting around all planets and sattellites. If objects orbit around ...
My text says that Aristarchus (310 BC – ~230 BC) measured the "angle subtended by the Earth-Moon distance at the Sun" ($\theta$ in the figure below) to establish the relative Earth-Moon and Earth-Sun ...