Giocare a ping-pong nello Spazio. Non con una pallina, con l’acqua

6 Ottobre 2017

In questo video – datato XXXX – l’astronauta della Nasa, Scott Kelly, mostra come giocare ping-pong in assenza di gravità, a bordo della stazione spaziale internazionale. Bastano un po’ d’acqua e due palette di materiale idrorepellente…

Il commento originale al video: «NASA astronaut Scott Kelly, who marked day 300 of a historic year in space on Jan. 21, 2016, shows off another fascinating feature of life in microgravity. Kelly used two paddles with hydrophobic, or water repellant, features to pass a sphere of water back and forth. Scientists use the microgravity environment of the space station to advance scientific knowledge in Earth, space, physical, and biological sciences that otherwise wouldn’t be possible down here on the planet. The paddles are polycarbonate laser etched so that the surfaces are actually arrays of 300 micrometer posts (0.3mm). The surfaces were then spray coated with a Teflon coat. The combined effects of surface roughness and non-wettability produce a super-hydrophobic surface capable of preventing water adhesion in dynamic processes. The larger the drop, the less force it takes to break it up. The smaller the drop, the harder you can hit it. Scott is demonstrating about a 4 mL drop (over 100 times larger than a rain drop)»