When NASA astronaut Dan Burbank left Earth for the International Space Station as part of Expedition 30 last November, he took along some knitting needles, but not for making a space sweater. The mission's commander brought them to make a point — quite literally — about what static electrical charges can do in zero gravity. As it turns out, they make for a captivating web video.
In this clip, part of a series called Science off the Sphere created by NASA and the American Physical Society, Burbank uses a piece of paper to statically charge three different knitting needles made from nylon, Teflon, and polyethylene. He then releases tiny (6-7mm) droplets of water near the needles using a syringe with a Teflon tip. The droplets, also possessing a charge, head for the needles and enter into an orbit around them, corkscrewing up and down their cylindrical shape, unable to escape the pull.
Eventually, the droplets collide with the needles, sticking to their surface while retaining a spherical shape. Burbank uses the different needles to illustrate the various behaviors he can make the droplets exhibit in the video. Also, by varying the flow of water out of the syringe, he's able to create large droplets and tiny ones, which he describes as looking "like flies at a picnic back in Houston."
While it might look like goofing off, demonstrations like this help show the sort of actual experiments only possible in the zero-gravity environment of the ISS that serve to further improve our understanding of the physical world.
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