The significance of these findings and theories was not fully appreciated at the time. A few years later in 1910, Ernest Rutherford did a ground-breaking experiment. Following the classical physics model, these electrons should have been small particles orbiting the nucleus in the same way as the planets orbit the sun, steadily losing energy until they fell on to the nucleus in other words, the atom should have been unstable. Again it was a rejection of the classical model, three years later, by Niels Bohr, that helped solve the problem. Bohr argued that the electrons must move in fixed orbits until deflected by the absorption or emission of a unit of energy.
Atoms emit radiation after various external signals and only at specific wave lengths.
Each of these photons is created when an activated atom or molecule passes to its normal or basic state. The concepts of classical physics could successfully explain many of the events of daily life, but it couldn t explain events on the subatomic level. Actually in order to explain the observations being made, the whole way in which physical events had been understood required fundamental revision by wholly new methods. This was achieved by Werner Heisenberg, a 24 year-old physicist described by his teachers as a person who dealt with the essence of a subject rather than getting bogged down in detail, a person with powerful concentration and ambition. Perhaps the success of this young mind can be explained by the critical perspective he developed through reading the works of great men such as Kant and Plato, which was later supported with sound knowledge he got from great physicists.