Or bats? Not necessarily by instinct, but at least in principle by the mechanics of their wings?
(And not in the vacuum of space, mind you. Just zero gravity)
Note: neither a physicist or biologist. So take my answer with a big bag o' salt.
My feeling is that yes, the mechanics of avian flight would function in low/zero g so long as there is air to produce lift force. However, an animal used to gravity that attempts to fly in zero g would almost certainly become massively disoriented, and I doubt that in practice it would make it very far (though, of course, it can't fall, so there's that!).
In principle, yes. The thing is, without gravity to act in "one" dimension to pull them towards the Earth, the gliding mechanism that most flying creatures would use to get around would not be effective and you'd find a bird flapping its wings constantly to maneuver. That being said, it'd give them the option of moving against the air rather than resorting to pushing and pulling on things like humans would. They might employ a sort of "flap and tuck" motion to provide propulsion and then minimize their profile.
Thanks to you both.
Pretty much what Horse said. In a zero-G volume of air it would probably be akin to underwater, where everything has neutral buoyancy. You'd need to get your movement from displacing the medium itself. Squid jets, flapping wings/fins.
A really good source for something like that is a series of books by Karl Schroeder, the Virga series (Sun of Suns, Queen of Cadensce, etc) where people inhabit a dyson bubble filled with atmosphere but no artificial gravity.
The mechanics for aerodynamic locomotion in freefall (or zero-g) would drastically differ from what is required on earth. In fact, airflow over a wing in freefall would result in a bird actually moving "up" relative to its body arrangement. That said, a bird would either a) be totally out of control or b) be able to move without shoving off of things in zero-g, depending on whether or not it has adapted to its new environment. My feeling is that most birds would flail around wildly and not really go anywhere; they'd probably just spin out of control or lazily drift in random directions. You might get that one weird bird that "gets it" and learns how to control which direction it drifts. Birds born into zero-g would grow up learning and adapting to their environment and probably have more control.
The above statement is made based on a general knowledge of physics and strong suspicions of how animals would adapt to alien environments. It should not be taken as fact in any way and is easily disputable.
In zero-G, even penguins can fly.
I actually wonder if penguins would be able to fly better than other birds in zero-g: might it be more like swimming than flying?
Quote from: Steerpike
I actually wonder if penguins would be able to fly better than other birds in zero-g: might it be more like swimming than flying?
It would probably be very similar, except where air as a medium provides less drag than water, they might end up making much more frequent wing movements to control direction.
To me the issue isn't gravity, rather atmosphere. If you have no gravity, you have no atmosphere. Its the resistance of atmosphere against your flying limbs that allow flight - gravity is certainly a part of that, but only in how gravity affects the atmosphere, and thus affecting your ability to fly. In zero-G you can jump and possibly leave the planet altogether, but no amount of flapping your wings or undulating your body is going to affect the flight or alter your path if there is no gravity present (and thus no atmosphere).
Quote from: Gamer PrintshopIf you have no gravity, you have no atmosphere.
You have atmosphere if you have something to contain it, like a spaceship or magic force field or whatever. And besides, the original post expressly stated that vacuum wasn't the concern.
You guys kill me. To the Googles!
https://www.youtube.com/watch?v=w4sZ3qe6PiI
That's the "vomit comet" so I'd say it's a miracle they're able to orient at all. Quick searching indicates common knowledge is birds are crafty little jerks and would probably be able to adjust to 0-g if not in a plane doing loop-de-loops, but the video definitely provides experimental evidence that they're mobile. ^_^
Quote from: sparkletwist
Quote from: Gamer PrintshopIf you have no gravity, you have no atmosphere.
You have atmosphere if you have something to contain it, like a spaceship or magic force field or whatever. And besides, the original post expressly stated that vacuum wasn't the concern.
True, but I was considering planets with our without gravity in my post, not so much contained enviroments of zero-G.
Quote from: Gamer Printshop
Quote from: sparkletwist
Quote from: Gamer PrintshopIf you have no gravity, you have no atmosphere.
You have atmosphere if you have something to contain it, like a spaceship or magic force field or whatever. And besides, the original post expressly stated that vacuum wasn't the concern.
True, but I was considering planets with our without gravity in my post, not so much contained enviroments of zero-G.
The problem is that the planet, by nature being a massive object, generates a gravitational field. If it doesn't have any significant gravitational field then it has no mass and is not a planet.
EDIT: It also seems as though brain has essentially ended the discussion with his video find. Good work!
I was thinking about the elemental plane of air and the astral plane, in 3ED&D. They are supposed to have "subjective directional gravity" but I find that boring and lame, so I was wondering how creatures would get around if the planes were largely devoid of gravity. There would also be magically produced gravity, but such effects would be very constrained.
Now I'm trying to imagine zero g vehicles, like some kind of gigantic-oar-propelled submarines, only oars spend half their motion outside the medium and that doesn't exactly work in the sky.
Maybe something like:
/->/->/
_<-_<-_
Where the panel extends perpendicular to the body and moves backward, then folds back to the surface and returns to its forward position. Several such panels would be arrayed in parallel and alternate.
"Ultratech" magical travel exists as well, but I'm focusing more on how the unwashed masses would get around.
QuoteNow I'm trying to imagine zero g vehicles, like some kind of gigantic-oar-propelled submarines, only oars spend half their motion outside the medium and that doesn't exactly work in the sky.
They could flap up and down. "Does ornithopting work in zero-g" is literally the discussion we are having right now. ^_^ Think davinci flying machine-looking things?
(Whether or not you could make an our with a large enough cross section to be efficient enough to be worth doing, and how light the vessel would have to be, these things I don't know--but imagining things like this (http://www.jeremybriggs.org/images/da-vinci-flying-machine.gif) flapping through the astral plane makes me happy?)
Hmm... this (http://4.bp.blogspot.com/-bjx3LB1nnAs/Th-csEICgFI/AAAAAAAAAMU/U7X7Bcf380c/s400/Martian_Airship.jpg) is what I'm imagining you could have, at least as far as a flappy oar was concerned.