Astronaut demos drinking coffee in space
Why Physics Stack Exchange recommends it
Physics Stack Exchange answerers point people to it as a concrete demonstration of surface tension and capillary action behaving differently in freefall.
Recommended by 0 people across 0 different months, 2012 to 2017.
What it is
A short clip from collectSPACE in which astronaut Don Pettit, aboard space shuttle Endeavour during STS-126, demonstrates a homemade zero-gravity coffee cup. The cup uses its shape and capillary action so the drink creeps along the walls toward the drinker's mouth. It is a quick, hands-on microgravity demo narrated by Pettit.
Cited in 1 Wikipedia article, including Donald Pettit.
What people said
Cites Cees Timmerman · 2012-10 · Physics Stack Exchange · on “Spinning bucket of water in zero gravity”
Going by this space coffee cup video, surface tension would keep the water in the bucket: [this video] Absent of pressure and temperature (pressure by molecules), the water would boil off and freeze [LINK] .
Cites fibonatic · 2013-12 · Physics Stack Exchange · on “Ink in a pen on an artificial satellite”
A space traveler on an artificial satellite will be in freefall around the planet it is orbiting. So the ink will not experience any acceleration relative to the pen due to the planets gravity. On earth the ink gets sucked up by the pen due to capillary action, but is counteracted by gravity. While in orbit the full "force" of capillary action can be used to suck up ink into the pen. A nice demonstration of this is a special designed coffee cup [this video] onboard of the ISS.
Cites Selena Ballerina · 2017-01 · Physics Stack Exchange · on “Effect of acceleration on rise of liquid in capillary”
No, the effect is quite the opposite. See Don Petit's Explanation of Space Coffee Cups [this video] for a graphic demonstation. You answer this simply by replacing $g$, in the relevant equations ( e.g. the Young-Laplace [LINK] or Capillary Equation [LINK] with a value modified to account for the additional inertial forces from the frame's downward acceleration. In particular, if the frame is in freefall, $g$ becomes nought - the capillary equation then tells us that fluids will rise arbitrarily high in columns. What this means is that there is nothing - or very little - to balance the forces of adhesion between fluids, and the fluids crawl everywhere in wild ways. In fact, this principle is used