A droplet of dye was dropped into a small vortex to create this photo. Aaron Cannon and his lab mates sent this to me. Great work Aaron et al. They commented “We (my lab partner and I) took this picture for a lab in ME 363, Instrumentation. The movie that this picture came from, was taken by a high speed camera, and is of dye being dropped into a beaker of water as the water is being mixed. The vortex is so lopsided because we were using a bolt as the stir bar. Unfortunately the dye had already been mixed in the water for some time. It is something simple, but we thought that it was pretty cool.”

Jordan Johnson sent me this photo a couple of days ago.  He said “This was in Richland, WA, 2007. Snow was unusual for that town.  The snow was super light and fluffy, so when my missionary companion blew on it, it formed the little shock wave you can see.”  I don’t know if these are necessarily shock waves, but you can see the velocity front.  Thanks Jordan

Harris writes again: when I was washing my car I noticed how the water was moving out from the jet after it hit the surface of the car. I believe at this point I had applied the wax rinse and therefore you can see a lot of beading occurring. What I thought was more interesting is that in the still image you can see that the water is not flowing away in a solid stream on the window, which is something that I would assume.

Harris writes: When I was washing the dishes, water entered a measuring cup and created a cone of water exiting the cup. I tired different flow rates and for this effect to happen it actually required a certain amount of water flowing into the cup. I tried to use a larger measuring cup but I could not replicate the results and the cup just filled up with water.

This phenomenon is magnificently explained in several papers, here is a start Link and photographed here and here.

Buoyancy or leftovers. -Ryan

Oil on water. -Ryan

Diffusion of syrup vanilla in water. -Ryan

Coanda effect -Ryan

Hydrophobic tomato leaf. -Ryan

A single drop of water creates a convex hemisphere when placed on a surface. The geometry of the hemisphere and the transparency of the water causes light to bend, just like light bends through a magnifying glass. This image shows how a drop of water on a glass surface can magnify text in this manner. -Bryan