A short excursion into the physics of the early 20th century: It was thought that the energy of a light beam was proportional to the light intensity. If you irradiate a metal plate with light, you can increase the light intensity as you like, you do not get electrons released from the metal, unless the light has at least a certain frequency. Einstein came to the hypothesis that:
Only one single sharp knife ...
Only one single sharp knife ...
Only one single sharp knife ...
A short excursion into the physics of the early 20th century: It was thought that the energy of a light beam was proportional to the light intensity. If you irradiate a metal plate with light, you can increase the light intensity as you like, you do not get electrons released from the metal, unless the light has at least a certain frequency. Einstein came to the hypothesis that: