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.
It is common to see this line: atoms are mostly empty space. That line appears inadequate and misleading. Atoms are ultimately made up of electrons and quarks. Electrons and quarks are by definition 'point particles', meaning they have no spatial extent. So there is nothing there that takes up space. Wouldn't it be more accurate to state something like 'atoms have mass and electrical fields but there is nothing there that takes up space', or, in the spirit of the 'mostly empty space' line to say 'atoms are nothing but empty space'.