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.
Subatomic Particles The rather steady increase of atomic masses through the periodic table was explained when physicists managed to split atoms into three component particles. The exploration of atomic structure began in 1911, when Ernest Rutherford, a New Zealander who worked in Canada and England, discovered that atoms had a dense central nucleus that contained positively charged particles, which he named protons.