Back in Cégep, in a physics class, we had a problem from the textbook assigned as homework. The question was whether turning a flashlight on and off would allow a stranded astronaut to get back to his space ship. Once all the numbers were crunched, it turned out that the answer was “no”. So the poor astronaut probably died out there.
This is the same textbook that had Tarzan rescuing Jane by swinging them on a vine over a pit of hungry crocodiles, and once we did the math, we discover that the vine breaks and they cannot make it across the ravine.
There was also the beer mug being slid along a bar top and the drunk’s reaction time wasn’t fast enough to grab the mug, so it falls to the floor and breaks.
That’s nothing. One of the physics professors here has a friendly rivalry with one of the engineering profs… Not a page goes by in the physics prof’s problem book that the engineer doesn’t fall to his death or get eaten by a grizzly or crash an experimental rocket sled or suffer some other such gory fate, and I understand that the engineer uses the physicist in a similar way in his classes.
But now your talking about a liquid gas mixture which would have more density. Plus, if the water hasn’t been boiled, then you have a whole day of “momentum” coming out of several orifices.
If I found myself untethered from my spacecraft in deep space, I’d immediately lose whatever suitable reaction mass I had. Maybe astronauts are better trained in that regard. “In the event of an emergency, seal all openings first.”
Yes, but the book I was talking about was published! Still, those problem sets sound pretty funny!
I also once had a calculus prof discus probability with a Russian Roulette game; one bullet, six chambers. As he’s setting up the problem, his wife, Mary, another prof, knocks at the door and takes him aside to ask/tell him something, and he comes back in looking a little exasperated. He continues the problem set-up, and asks “what is the probability that Mary “wins” the game by finding the bullet?”
AFAIK, they are still together 10+ years later, amazingly.
Quite correct.
Nobel prize winner Richard Feynman did some experiments on this while at college. He showed (long before space travel) that urination is under muscular control, and is NOT dependent on gravity.
O.K. let’s take this a step further. Since it is universally known that farts are flammable here on earth how would adding a strategically placed igniter (i.e. like those in bbq grills) to the flatulence vent influence the suit’s anal propulsive properties? :eek:
Without an oxygen source, it won’t do anything. On the other hand, I don’t see anything that could go wrong with hooking an oxygen source to your rectum and igniting it. Nothing at all could go wrong.
If an astronaut, say, had only j-u-s-t missed a grip, and needed a nudge to reach the cable (for example, in Mission to Mars, where everybody was going to be in a ship in a few minutes anyway and Tim Robbins was only inches away from the rope), I can imagine the last desperate attempt being to basically stab a hole in the suit to vent, and pursing (as well as modern suits can allow) the hole enough to increase the gas escaping velocity.
Definitely better get into atmosphere quick, and definitely definitely don’t want a Bad Guy to puncture your suit in the opposite direction, leaving you to pinwheel.
It is almost certainly the case, that if you were holding in a fart, that would be released as well. And that could be detected by distant alien astronomers and almost certainly interpreted as life.
Which only confirms my suspicion that we need to complement our extrasolar planet survey with Smell-O-Scope results.
And yet, all is not lost, because as Santo Rugger so astutely points out, the effect of additional farts is cumulative!
Suppose the astronaut had enjoyed the freeze-dried Mexican Fiesta Pak just before the spacewalk, and was tooting at the rate of one fart per minute. That’s a lot, but I’ve had gas attacks that were worse.
After one hour, given your assumptions, the astronaut would have traveled 250,000 micrometres, or a quarter of a meter! A second hour, even without any further tooting, would cover another half-meter via momentum alone.
Granted, that’s a lot of flatulence to travel a short distance, but it might be the difference between life and death!
What is more important, the mass of the reaction mass or it’s exhaust velocity? Say an astronaut was trapped in the center of a huge open space in a vacuum and he took off his clothes which have a mass of 3 Lbs. He starts to swing the clothes in a circle as fast as he can and lets go. I assume he will move in the opposite direction of the clothes at some velocity, yes? If he just gently pushed the clothes away his delta-V would be much, much less, correct?
I have actually done preliminary experiments in microgravity to determine if Diet Coke & Mentos could be used as an emergency rocket.
My intuition is that the actual mentos effect wouldn’t help much because of the lack of convection in zero-g, but obviously uncapping a 2-liter bottle of Diet Coke in a vacuum is going to result in some propulsive ejection effects. I’d have to do some serious calculation to figure out if it would be more effective than just throwing the sealed bottle in the opposite direction.
I’d WAG it’d depend on your throwing arm, but as long as you’re not doping up on Bane level steroids opening the coke would give you more thrust. You’d not only have the pop carbon fizzing out but you’d have the liquid boiling.
And thats a great lead-in for the incomparable Poul Anderson novella, “The Makeshift Rocket” (Ace Double F-139 b/w Anderson’s “Un-Man and Other Novellas”).
Here’s the blurb:
I’m a klutz at physics, so cant speak directly to the situation, but I have read since that old hard SF Poul had it worked out in a plausible manner. It’s a fun read, too.
