Category: Wave Particle Duality

So light is a particle, right? But wait! What about diffraction and interference? Didn’t Foucault show that the speed of light in air and water needed to explain diffraction disagree with experimental data if we assume that light is a stream of particles (Figure 7)? And isn’t interference supposed to be the obvious signature of…

cTo observe the Compton Effect we need a source of high-energy photons and a suitable spectrometer to observe the frequency shift in photons as they recoil. The source of short-wavelength photons is not much of a problem—a 137Cs source produces photons at a wavelength λ = 1.88 × 10−12 m. Actually, the more common unit for expressing…

We saw the importance of the concept of quantization as a way of solving a large number of problems with which classical physics had struggled without success. Quantization certainly suggested that light—as Einstein had proposed in 1905—is a stream of particles. However, many physicists refused to take quantization as more than an elegant mathematical trick…