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.
There is an empty space between atoms Atoms are completely solid Atoms have no internal structure Each atom (of a different substance) is different in size, weight and shape. Timeline: 180 0âs Scientist: John Dalton John Dalton was the first to adapt Democritusâ theory into the first modern atomic model. JOHN DALTONâS ATOMIC MODEL: 1. All matter consists of tiny particles called atoms 2.