Astronomers use the principle of parallax to measure distances to the closer stars. Here, the term parallax is the semi-angle of inclination between two sight-lines to the star, as observed when the Earth is on opposite sides of the Sun in its orbit.
Ernest Rutherford discovered that atoms contain mostly empty space, with his gold foil experiment. Bhor discovered that the electrons are not randomly placed around the nucleu â¦ s.
Atom History Timeline Erwin Schrodinger John Dalton - Designed symbols to show how atoms combine to form other substances Ernest Rutherford - Discovery of the Nucleus! - Found that an atom is made up mainly of empty space J.J Thompson/Discovery Of Electrons - Thomson determined the charge to mass ratio (e/m) of an electron equaled 1.759 x 108 C/g through experiments he did with gas discharge tubes (Cathode Ray Tube Experiment) Democritus - Believed that the universe was made of tiny âindivisibleâ particles