Concept of deBroglie

[allyz1F]

Why does the deBroglie equation not apply to light? This may be a very general question but I wrote explicitly in my notes “equation works for any particle with momentum, but does not apply to light” and I am unsure as to why that is.

[Esin Gumustekin 2J]

The deBroglie equation only applies to objects with mass since the equation is h/p (p=mv). Light does not have mass and thus you can not apply the deBroglie equation to it. Instead to find the wavelength of light you would use c=(wavelength)v or E=hc/wavelength.

Hope this helps!

[Karan Singh Lecture 3]

Its because light has no mass. Hopefully this helped.

[Akshay Anand]

De Broglie only applies to "objects with mass." Therefore, when determining the wavelength of an electron at a certain velocity, you would use De Broglie. However, since light has no mass, this equation can't apply.