Make a wish: these elegant forms show what happens beneath the surface of water when a coin-shaped disk falls (or, in this case, is pulled by the attached vertical rod) into it. A vase-like cavity opens up behind the disk, which then collapses into an hourglass shape, from the neck of which the air is pushed out in a jet moving at supersonic speed.
Image of the month
A tiny, supersonic water jet
July 21, 2010
Make a wish: these elegant forms show what happens beneath the surface of water when a coin-shaped disk falls (or, in this case, is pulled by the attached vertical rod) into it. A vase-like cavity opens up behind the disk, which then collapses into an hourglass shape, from the neck of which the air is pushed out in a jet moving at supersonic speed.
