People on Twitter are currently posting a video of a group playing what appears to be a wet version of Jenga, which is causing some interesting physics to circulate on the Internet. Competitors take turns adding a drop of water to an already overflowing cup in this game. The water rises with each nervous drop, making it appear inconceivable that another drop will not bust the tiny, physics-induced dam that appears to exist at the river’s edge. Why isn’t it leaking sooner? Surface tension is the reason behind this.
TENSION ON THE SURFACE OF AN OVERFLOWING SURFACE, if you fill a glass of water to the brim at home and start dropping coins in it, you’ll quickly see that the volume of water can “overflow” without spilling. This is due to the fact that water molecules are attracted to one another, producing a (although weak) link that allows them to defy gravity for a short period of time. Water’s stickiness is perhaps best exhibited in space, where astronauts must deal with leaks that occasionally spew Flubber-like blobs of fluid into their living quarters.
The similar effect nearly killed Italian astronaut Luca Parmitano in orbit in 2013, when a glob of water built up inside his suit during a spacewalk. The blob developed for 23 minutes until it started making menacing moves toward his nose and mouth, but Parmitano was able to reach inside the space station and correct the situation. Back on Earth, the attraction of water molecules is strong, but it is not unaffected by gravity. As shown in the video above, breaking the surface tension and sending the extra fluid pouring over the glass is only a matter of time in “Water Jenga.” So, the next time you’re stuck with nothing but a glass of water and two cups, why not try Water Jenga?
Among all the possible ways to die in space — shapeshifting aliens, robots that lose their minds and try to kill you, potato chips flying into the console, etc. – drowning is certainly the last thing on anyone’s mind. Yet, during a spacewalk outside the International Space Station in July 2013, astronaut Luca Parmitano found himself in just that situation (ISS). Parmitano went on a six-hour Extravehicular Activity (EVA) when he detected water accumulating inside his helmet, in one of the most perilous occurrences in spacewalk history. He informed NASA of the problem, but they were unaware of the gravity of the situation at the time.