Here's mine.
Boat wakes...
Now some of you may know I have a bit of a marine background, but it *isn't* in fluid dynamics.. so my knowledge of just how the wake concept works is a bit.. shallow. (Geddit!?)
But I always wonder in awe, as I watch a little boat putter by in a calm marina, and then watch the multiple wavefronts spread out behind it, for hundreds (if not thousands) of metres, and also watch those same waves gently but firmly lift up huge pontoons, seemingly expending enormous amounts of energy as they get moved up and down... And all that power/energy came from a tiny chunk of aluminium, powered by a 5 horse Evinrude..???? Nah, not possible.

Actually, I do sorta understand the mechanics of it all, but it just looks *wrong*!!! Does anyone know how to explain it all, but in a way that my subconscious, rather than my conscious, will finally accept?
Oh, and for those who need a picture, scroll down to the bottom of this page....
http://www.egamiimage.ca/home.html
As it's a cool shot imo, I hope no-one minds me giving his website a free plug..!
Oh, and I also have a big problem with the much loved concept of infinity, but I shall leave that for another day...
∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞ ∞