Collisions of columnar waves of equal and unequal force
Four labelled cases of waves that rebound, penetrate or bend on impact
Four labelled notes, each with its own marginal figure, treat what happens when columnar waves meet. When semi-columnar waves strike only up to the middle (a b, c, d c), the struck half rebounds and rides over the part that did not strike. When two columnar waves of equal size and power strike head-on entirely (f g, h, i K), they return wholly backward with no penetration of one into the other. When the waves are unequal (n m, o p) they break their 'law': the greater does not bend and the lesser merges into it. And when equal waves are born at different times (a b, c d) their collisions are unequal in force, so the course of the second bends before that of the first.
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Partial impact: the struck half rebounds and rides over (a b, c, d c)
Columnar waves that strike but do not cut each other as far as the middle: the half that strikes rebounds backward and passes over the part that does not strike.
Equal head-on impact: full rebound, no penetration (f g, h, i K)
When two columnar waves strike each other entirely with equal size and power, they return wholly backward without any penetration of one into the other.
Unequal waves break their law: the lesser merges (n m, o p)
But if the columnar waves are of unequal size, the greater and the lesser do not keep their law, because the greater does not bend and the lesser unites with that greater.
Waves born at different times collide unequally (a b, c d)
If the birth of the equal waves is earlier for one than the other, their collisions will not be made with equal powers, so the course of the second bends before that of the first.