# surface tension

### Bath-Time Fluid Dynamics

SteelyKid's every-so-often bath was last night, and as always, she was fascinated by scooping up water in a hexagonal cup thing that's part of one of her bath toys, and watching it drain out. Which is completely understandable-- not just because she's a baby, but because there's a bunch of physics at work, here. I realize this is trampling on Rhett's territory, but I made a little video showing the physics part (in the sink, not the tub, because I don't want to have the pay the therapy bills that would come from posting video of SteelyKid in the tub): The explanation is laid out in the video…

### Surface Tension vs. Floating

Check out this video demo: So, that is just plain water. If I am careful, I can make that thin aluminum disk stay on the surface of the water. This is not the same as floating in Archimedes principle. It is different. This is staying on the surface because of surface tension. Bouyancy I think my best explanation of buoyancy was in the post about MythBusters floating a lead balloon. But, basically for buoyancy there is an upward force from the water on the thing that is floating. If I want to explain this in terms of the particle model of a gas or fluid, I could say that the particles in…

### Weekend Diversion: Walking on Water!

Clearly, neither the man nor the bull below is headed for anything good in their attempt to walk on water, and for that matter, neither is this poor, bristling cat, but what about this reptile? Unbelievably, this lizard actually can walk on water! And without using any surface tension tricks like insects do, either. No, whereas a human puts his foot into the water and sinks, this lizard has a very low mass and a very large surface area on his feet, allowing him to "run" on water as long as he moves quickly enough. For this lizard, that's about 10 miles-per-hour. As opposed to a human, who…

### Kitchen Science: Magic Milk

tags: magic milk, surface tension, physics, streaming video This is a really interesting video that shows a fun science experiment that you can do in your kitchen using all that extra milk that you have hanging around in the refrigerator -- this is especially good entertainment when the conquering hoards of relatives' kids have invaded your home for the holidays [1:14]