Looking at a creek on a Sunday stroll, and seeing lots and lots of concepts from hydrodynamics class.
For example below, you see waves radiating from each of the ducks. And you see interference of waves from all those ducks.
What happens if the ducks bring their waves closer?
At some point, all those waves from the ducks are going to hit the weir in the picture below.
And there, they are going to somehow react to the flow field caused by the changes in topography.
And you can spot so many different phenomena: Standing waves, hydraulic jumps, and lots more!
Watch the movie below to see the whole thing even better!
Btw, you might remember this spot, I have talked about standing waves from right there before. Interestingly, the wave pattern in the other post looks really different, probably due to different water levels or changes in topography (maybe someone threw in rocks or they did some construction work on the weir?). But it is still just as fascinating as last time :-)
And for those of you who like to see a “making of”: