The particles were thrown out on the wave front of the explosion, and they split further, spontaneously.
The student will note that for the sake of greater precision we here say wave front instead of wave.
A mirror, M, intended to reflect the light straight back must be set normal to the ray, not tangential to the wave front.
The two men climbed slowly up the slope that had been the wave front of molten rock.
|wave front |
The set of points in space reached by a wave or vibration at the same instant as the wave travels through a medium. Wave fronts generally form a continuous line or surface. The lines formed by crests of ripples on a pond, for example, correspond to curved wave fronts.