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.
In what year did Rutherford demonstrate that the atom is mostly empty space with a small positively. charged nucleus containing most of the mass and low mass negatively charged particles orbiting. this nucleus. He was also credited with naming alpha and beta radiation/particles.