Q1-In hugyen's principle of wave theory why the waves are move in forward direction not in backward direction means they move forward as a new source why not in backward direction?

Question

Ans- I think that waves move in forward direction sir i know that only so please give me a perfect answer with proof if any

Answer 1

Negative wavelets.
The original Huygens Principle does not clearly account for the wave direction. The important point is that the wavelet phase must be considered. However, the diagram below shows that additional negative wavelets easily solve this problem. The use of black and white wavelets proves to be preferable.

Regular traveling waves cannot travel backward.
The wavelets are well separated forward but they cancel backward.
THIS IS FROM:
http://www.rhythmodynamics.com/Gabriel_LaFreniere/sa_Huygens.htm