This question already has an answer here:
Huygens principle says every point of wavefront emit wavelet in all directions. Then why does a back ward wave not exist? Can any expert tell real answer? On different sites I get different and contradictory answer.
I am asking question from my class 12 book. It says " Huygens argued that the amplitude of the secondary wavelets is maximum in forward direction and zero in the backward direction; by making this adhoc assumption, Huygens could explain the absence of backwave. However, this adhoc assumption is not satisfactory and the absence of the backwave is really justified from more rigorous wave theory."
What justification is given by wave theory?
answer explained by Marty green on Is Wikipedia wrong about Huygens-Fresnel Principle?
is different from answer given by Acuriousmind on
Which is correct?