Flying Circus of Physics for May 2013

The May stories at the main FCP site include examples of very large and energetic bathtub-type vortexes that form over drains. One draining vortex was responsible for emptying a lake into an underlying salt mine, consuming several barges in the process. Another story deals with one of my fascinations (or perhaps one of my shear fears): very deep holes, ones in which I would fall almost forever. In the videos stones are dropped into the holes, thus allowing us to approximate the depth by the time of fall. In one hole, we hear a stone land 11 seconds after it was released, giving a depth of about 450 meters. But in another hole, we hear the stone land 35 seconds after it was released, giving a depth of about 3.2 kilometers. That really kicked up my nightmares. There is also a story about exploding manholes, including a video of one explosion in which a heavy manhole cover is launched as a high-speed projectile.

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