I have an idea. when you have a compression wave, any amount of amplitude is an imbalance right? so the waves amplitude will always be accelerating towards the origin. Now due to the symmetrical properties of such changes in amplitude, the average value will be zero. So anyway, here is my idea. If i take a photo of an area of water, say on a lake, with a long light exposure, vertically aiming down onto the waters surface. Should i be able to see to the bottom? I mean the critical angle for the waters refraction index is created by the incidence ray from the camera for a shorter time than when the angle of refraction is minimal, so theoretically this should work right? Spiritually speaking of course