Wave-particle duality is a historical concept and states that light can behave both as a [[wave]] and as a particle ([[photon]]). While light behaves like a wave in the [[Double Slit Experiment|double-slit experiment]], experiments such as the [[Photo-electric Effect|photoelectric effect]] suggest that it is a particle. ![[particle_wave_duality.excalidraw.light.svg]] Interestingly, this seeming contradiction is not only observed with massless [[Photon|photon]], but also with [[Electron|electrons]]. While we usually think of them as massive, small particles, in [[Davisson-Germer Experiment|experiment]], we can observe diffraction and interference effects. This suggests that electrons can also behave like a wave. This observation was formalized by De Broglie in his PhD thesis with the [[De Broglie Wavelength|De Broglie wavelength]]. These initially contradictory results are explained by [[quantum mechanics]]. Both [[Electron|electrons]] and [[Photon|photons]] are governed by quantum mechanics and the different behavior depending on the experimental setting is explained in this one theory. >[!read]- Further Reading >- [[Wave]] >- [[Light]] >- [[Electromagnetism]] >- [[De Broglie Wavelength]] >- [[Electron]] >[!ref]- References > L. D. Broglie, Recherches sur la théorie des Quanta, Ann. Phys. **10**, 3 (1925).