If Huygens Principle states that every point on a wave acts as a source of secondary wavelets, then:
Is the new wavefront formed by the interference of these secondary wavelets?
If so, then how can a light source have uniform intensity if there is constructive and destructive interference happening during the light's propagation? (See image)
(Note: This image was downloaded from the internet. The yellow boxed portions, the black arrows that point to it and the write- up near the arrows illustrate my doubt. The rest of the write- up came along with the downloaded image.)
That is, in both cases, the waves interfere. But, in the propagation of a plane wavefront (according to Huygens Principle), the resultant wave (formed by the interference of secondary wavelets) has uniform intensity. Whereas, the intensity of the resultant wave in the image on the right, is not uniform. Why?