J Thomas on June 12, 2011, 09:13:28 am
Some time ago we had a long discussion about how to arrange cups etc in nul-g or in microgravity. It was topic drift in some other topic and I didn't find it with a quick search.

I stumbled upon some actual evidence about this.

http://www.youtube.com/watch?v=7obLT4s2-HA&feature=fvwrel
http://www.youtube.com/watch?v=Oz36sApgMMo&feature=related
http://www.youtube.com/watch?v=pk7LcugO3zg&feature=related
http://www.youtube.com/watch?v=Fg1RMEIP6i4

Why does it work? Water has high surface tension. So water won't splatter into tiny droplets unless it gets considerable force.

So water tends to stay in cups. And a cup with a sharp crease, or a hydrophilic strip, will get water creeping up that narrow band.

Things that looked like they'd be big problems from a priori thinking, appear not to be much of a concern at all. I predict that if you do spill water in ways that make lots of little splashes, you do have a problem -- each tiny droplet will tend to continue until it hits some solid surface, and there it will tend to spread out or bead up depending on the surface, or if it hits hard enough it might bounce and split into smaller droplets. So you'll be cleaning your water off every surface and not just one floor. Worse than on terra, but still not a big deal unless you have something that can suffer water damage, like electrical stuff etc.

It makes sense to me that you don't want to use drinking mugs. Even with a special rim to divert the liquid back into the cup, you are accelerating all the liquid every time. If you instead have some tubing running from the cup to your mouth, you can just move as much as you want while the container stays in one place, its liquid bubble gradually getting smaller as you drink. Or there might be a design with a sort of jigger that lets you shake a cup and get one swallow of liquid out each time, that you will expertly aim toward your mouth. There's room for ingenuity, and there could be fads etc as new solutions come up. It isn't a big problem, it's a little problem.

If you do want something like a coffee mug, you could probably learn to use one. It starts out sitting on a table in microgravity. You pick it up, and halfway toward where it's going you flip it over and gradually slow it down. As it passes your mouth you divert one swallow. Then you use the reverse procedure to get it back to the table, and by angling the mug just right relative to the direction of motion you can convert much of the forward momentum into spin, which dies down as the cup rests on the table. Or just move slowly enough that surface tension keeps the water in the mug. With practice it would look natural, but newbies would not be able to do it at all. With practice, you could do it perfectly while drunk.
« Last Edit: June 12, 2011, 10:13:49 am by J Thomas »

deliberatus on July 10, 2011, 09:24:11 pm
i get the i,mpression that the physics of the situation in z G or microgravity is that carbonated beaverages are not a very good idea.
Now, are they TOTALLY out of the question, or merely problematical?

Killydd on July 11, 2011, 07:44:16 am
Carbonation shouldn't be much of an additional problem.  After all, the bubbles inside won't rise to the surface and pop the way they do under gravity.  If you open a can of pop here, it doesn't expand much unless you shake it up, and presumably people would learn to be quite careful about not shaking their champagne or soda before opening it.  Over time more bubbles developing would expand it, but people raised in low g would either make sure the container is large enough or drink it quickly enough to keep that from being  a problem.  Then again, surface tension would still keep it in one piece normally.  0ooOf course, drinking from straws might very well be so much simpler that a simple desire to not spill things as easily would keep us using bags of drinks in space.

Tucci78 on July 11, 2011, 07:59:01 am
Fuhgeddaboud drinking in space. That's a solved problem, and has been since the early '60s.  Where the 11 July strip fails is in the depiction of cooking in space.

All those kids are floating in microgravity around the cooking set-up, right? Okay. What happens when such free-floating cuisine artistes try to do something to anything on their work platform?

Action, meet reaction.

Experience in microgravity thus far has shown that one of the key priorities for any operator is to get anchored.  Floatiness looks real cool, but it makes doing stuff iffy at best, and impossible most of the time.

I'd expect to see each of those cooks wearing something like a weightlifter's belt or a rigger's harness, tethered to the work platform on either side by something like bungee cords (gonna be a whole helluva lot of bungee cords needed in the Asteroid Belt) so that when they use their muscles on anything they're preparing, they don't wind up shoving themselves away from the cooking platform.

Oh, yeah. They're in microgravity. Why maintain an "up-and-down" orientation in that chamber, or at that work station?  If there's so much room, better it were set up as a big box or tube so that people can work in the interior and the exterior simultaneously.
"I is a great believer in peaceful settlements," Jik-jik assured him. "Ain't nobody as peaceful as a dead trouble-maker."
-- Keith Laumer, Retief's War (1966)

Apollo-Soyuz on July 11, 2011, 07:25:16 pm
They've had specialized coke and pepsi dispensers for the shuttle mission, (IIRC they work like an easy-cheese can does), but I read that the bubbles are not handled well in the stomach in microgravity.

https://secure.wikimedia.org/wikipedia/en/wiki/Space_food#Processing

i get the i,mpression that the physics of the situation in z G or microgravity is that carbonated beaverages are not a very good idea.
Now, are they TOTALLY out of the question, or merely problematical?