Question

Discuss Einstein and Planck's collaborative work on the photoelectric effect and their differing views about whether science research is removed from social and political forces.

Answer 1

Classical physics was unable to explain the threshold frequency, which is the frequency of light at which electrons are emitted from the surface of a metal. It predicted that energy from light would be absorbed over time until an electron had sufficient energy to leave the surface of the metal. Einstein used Planck’s theory and the concept that photons carried energy to explain the photoelectric effect. Einstein assumed that light existed as photons, each with an energy equal to E = h f and that the number of photons

determined the light intensity. Photons with the highest energy correspond to the highest frequency, and an electron would not be emitted from a metal surface unless the photons

possessed energy equal to or greater than the energy needed to overcome the energy holding the electron on the metal surface. The energy required to release the electron from the surface was called the work function, W. Einstein was able to combine the photon energy with the work function and the KE of the emitted electrons in the equation h f = EKmax + W

During the wars Planck's views on the independence of science was strong. He argued that science should be an independent pursuit of knowledge, not controlled by the needs of the state or industry. At the beginning of WWI, Einstein was the peaceful while Planck was urging the scientific community to support the war effort. In contrast, at the beginning of WWII, Planck was resisting the militarisation of scientific research while Einstein argued for scientists to aid the military in development of nuclear weapons.