Motionless waves

September 16, 2014 8:06 PM

Recently, when flying over islands, I've noticed that the waves on the seashore appear to be motionless from cruising altitude. That is, you can see the white foam on the beach but it seems to be frozen in place and not ebbing/returning. Is there a name for this visual effect?
posted by orrnyereg to Science & Nature (2 answers total)

The waves are constantly moving, crashing and ebbing on top of each other to the point where you can't tell one from another, and being far away and moving yourself only enhances the effect.

In a way, you're seeing a flicker fusion effect. One wave is "drawing" white, and another wave "draws" more white, and so on and so on.
posted by Cool Papa Bell at 10:03 PM on September 16, 2014

Yes, this is basically a long-distance stroboscopic effect. A bit closer and you might get linear version of a wagon wheel effect, although I think the rate of change would be too slow.
posted by Happy Dave at 6:35 AM on September 17, 2014