Interference occurs when two waves combine, resulting in constructive interference when their peaks align, which can happen if one wave travels a path that differs by a full wavelength. Destructive interference occurs when the path difference is half a wavelength, causing the peak of one wave to cancel out the trough of another. The computations for these phenomena rely on applying specific equations to the geometry of the wave interactions. Understanding these principles is essential for grasping the concepts of interference, diffraction, and diffraction grading. Mastery of these calculations will clarify the material presented in physics textbooks.
