Huygens Principle

Christian Huygens (1629-1695), in the late 17th century, proposed a method of wavefront representation, where each point of a wavefront behaves as a new source of elementary waves, which propagate beyond the region already hit by the original wave and as often as it. This idea is known as the Huygens Principle.

For a given instant, each wavefront point behaves as a source of Huygens elementary waves.

From this principle, it is possible to conclude that in a homogeneous environment and with the same physical characteristics in all its extension, the wavefront moves maintaining its shape, as long as there are no obstacles.