https://openstax.org/books/college-physics-2e/pages/27-2-huygenss-principle-diffraction
27.2 Huygens's Principle: Diffraction - College Physics 2e | OpenStax
Figure 27.4 shows how a transverse wave looks as viewed from above and from the side. A light wave can be imagined to propagate like this, although we d...
huygens s principle27 2college physicsdiffraction2e