What principle did Fresnel use to explain diffraction?
Newton's laws
Huygens's principle
Einstein's theory
Bohr's model
Answer
Fresnel used Huygens's principle of secondary waves and Young's principle of interference to explain diffraction by straight edges. This led to the first satisfactory wave-based explanation of rectilinear propagation.
Shedding Light on Augustin-Jean Fresnel: The Brilliant Mind Behind Modern Optics