February 8, 2012
Dance of the Droplets
Editor’s Note: Don Pettit demonstrates some weird physics onboard the space station for the Physics Central educational site.
Editor’s Note: Don Pettit demonstrates some weird physics onboard the space station for the Physics Central educational site.
Oh! What a lovely sight!…
Comment by Othella Vreugd — February 9, 2012 @ 12:11 pm
Don didn’t mention it, but the individual orbits decay very rapidly due to the air drag the droplets experience.
It’s interesting that their major axes also precess very rapidly. I don’t understand it but I presume it’s also caused by air drag on the droplet. A decaying satellite orbit doesn’t exhibit this kind of precession, presumably because the exponential decrease of atmospheric density with altitude limits the drag to perigee, circularizing the orbit before it finally decays. Here the air is uniformly dense around the needle so the drag is a function only of velocity, and somehow that causes the orbit to precess within its plane.
where the atmospheric density decreases exponentially with altitude, so if the orbit is initially elliptical it will rapidly circularize before it decays.
Her where here it is a constant.
Comment by Phil — February 10, 2012 @ 2:50 am
this was so fascinating, it is almost musical…design or chaos?
Comment by Linda Clark — February 11, 2012 @ 6:15 pm
Amazing! And very interesting. Thanks for sharing !
Comment by Celia perigord — February 13, 2012 @ 11:21 am