Hello,
the de Broglie relation says: wavelength= h/p (h=Planck const, p=momentum)....means: Lightwaves with a certain wavelength have a momentum. Then waves should set free an electron (photoeffect).
This conclusion was proven wrong. Why exactly is this so?
Regards
Lothar
Hello, Lothar. According to standard comprehensive description in some phenomena the light is a particle in other ones the light is a wave. Photoeffect is an example of first type phenomena. Einstein supposed that light is absorbed by portions and this statement in fact allow to explain photoeffect.
Let's consider the electron as a wave. But the wave is an oscilattion which is goes ahead in space. Something unlimited. Even if we take mean value in a period of time this result does not explain the red border of the photoeffect, for example.
The photoeffect happens immediately after the light hits the metal. If it was a wave there are calculations showing this would happen in hours.
Dear Ilian, Dear Alexander,
Ilian states, that there are calculations showin that the dissipation of energy transmitted by a wave needs a long time.
Let me modify the wording of my question:
what was the reason for Einstein to exclude waves from being responsible for the photo-effect.
Lothar
Dear Lothar, I don't know what Einstein thought. But there are experimental facts, which are also known as the laws of photo-effect. 1. Photo-current is proportional to the intensity of light. 2. Speed of photo-electrons is proportional to the light frequency. 3. There is red border of photo-effect (threshold frequency). How to explain these laws using the waves concept?
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