May
12th
2018
Thought experiment #1: Rainbow in a box · 5:10pm May 12th, 2018
So I had a question I can’t substantiate a good answer for. Let’s try posing it to a wider audience.
Here’s my thought experiment:
- Take Rainbow Dash. Get her to wear a saddle. If she complains, offer a Daring Do book.
- Attach 8 steel cables to said saddle.
- Make a hermetically sealed, empty (save for air) acrylic glass cube at least three Rainbows long, weighing, say, about the same as Rarity. Or at least, as much as Rarity admits she weighs.
- Place Rainbow inside said box and attach each cable to the corners of the cube from the inside, so that Rainbow is perfectly fixed in relation to the box.
- Ask Rainbow to fly as fast as she can. If she isn’t doing this on her own yet because she wants to get away from you as fast as possible.
Will the box fly or not? To clarify, Rainbow will obviously have the option of using inertia to move the box by flailing inside, but that’s not what I’m wondering about. Will she be able to keep it in the air?
What we do know:
- Rainbow can lift the box if she can grab it – it weighs the same as Rarity or less, and we know she can lift Rarity and perform high-G turns while holding her. There’s no doubt that were the box suspended on one cable beneath her saddle, she’d fly it anywhere.
- Rainbow can fly with just one wing and perform other aerobatic tricks that would be impossible if the function of the wings was purely aerodynamic, so it being hermetically sealed does not necessarily prevent her from flying.
The answer, therefore, depends on your ideas on how magic works in Equestria, but here’s the thing: Unless the magic of three tribes is fundamentally different, it should have bearing on how the other tribes’ magic behaves in relation to the same box.
So, any takers?
Hm, interesting question!
...It seems like it'd be something that'd vary with universe, though. And I'm not currently thinking of evidence from any particular one for it. Still, a potentially useful question to ask for worldbuilding.
Being in the box, she shouldn't be able to lift the box (since when she flaps her wings, the air actually pushes the box downwards and other physics stuff). But this being Equestria, she'll probably fly since she doesn't know she shouldn't be able to (this is probably kinda like Pinkie Pie works).
4858903
Canon offers no direct evidence, so there’s no doubt that different fanfic universes would give different answers, and it would mostly depend on how magic interacts with the box (rather than air) – and by extension, other solids.
Which is why I say answering this hypothetical would be important for other tribes as well.
I'm assuming that the box isn't anchored to anything. Conventional physics suggests to me that Rainbow's going to cause all sorts of chaos to the air inside by flapping around in her attempt at escape, and while the box might not fly, there's a pretty good chance it would wind up tumbling around due to the disturbances inside. Sort of like if you put an angry badger in a box (not that I've ever tried this).
Having said that, I do think that they have some sort of flight magic, since their aerodynamics suck, and their wings are far too small to actually lift them (assuming an Earth-like atmosphere). So if they use some sort of short-range teleportation magic for thrust (kind of like what Kris mentions in The Maretian for their FTL drive) then the box would move. Possibly not in any particularly controlled manner, since the air currents inside would be quite chaotic, and it would probably take a while for Rainbow to figure them out well enough to control the box.
I also seem to recall that that came up in Arrow 18: Misson Logs, when Rainbow was trying to fly in 0g. She could, but had trouble controlling herself (this is true of birds, as well).
(Cats also can't fly in 0g, but that's not really germane)
My gut says that the box would move, more or less in the direction Rainbow wanted to go, although its flight would be somewhat chaotic due to her flapping her wings inside.
I also think that her solution to getting out of the box would be smashing into the ground at a high rate of speed, pulling up at the very last second: if it works to demolish a barn, it ought to work to open a box.
Also, I'll just leave this here:
--Silver Glow's Journal
I guess I see a two possible outcomes.
There’s also definitely some kind of magic that lets pegasi keep chariots and carts perfectly level while flying or even hovering. I wonder if that would help with this specific setup—or interfere because that magic force can’t distinguish between an object around the flying pony and an object behind the flying pony.
4858917
That really goes without saying, so if that confuses you, let us amend the question to “Will Rainbow be able to keep the box in the air and avoid touching the ground?”
Mmmm… No, they definitely do not.
vignette.wikia.nocookie.net/mlp/images/5/5e/The_Pegasi_movers%27_truck_S1E15.png/revision/latest?cb=20110920165833
q.v. Feeling Pinkie Keen
If pegasi used any manner of teleportation to move, I’m pretty sure this scene would be outright impossible. Negating gravity in some way is an option – however, if pegasi negate gravity on themselves and their carts, but the actual flight is accomplished aerodynamically, the box wouldn’t fly, but Applejack could, in turn, kick the box with Rainbow out of the atmosphere entirely.
Considering how carriages attached to flying pegasi behave - I'm pretty sure that their flight at least partially magical. So I think that box fly. Maybe pretty bad, unsteady and chaotic - but RD would be able to lift the box.
4858921
4858928
Chariots are probably the strongest argument that says the box should fly, if only because we know that pegasi are able to stop in the air with a chariot – it happens in Feeling Pinkie Keen twice, and one of the two cases is definitely well before Twilight gets hit in the head with an anvil, so we can’t even dismiss it as a hallucination. And from Three’s a Crowd we know that these chariots don’t even require wheels, so the magic should also apply to a box.
At the same time, if the flight is aerodynamic, but keeping aloft is accomplished through negating gravity on both the pegasus and the chariot, the box would be weightless, but still wouldn’t fly…
4858926
Based on my own headcanon and what we've seen in the episodes, I think yes. I probably wasn't all that clear in my first post.
I think that using simply conventional physics (warning: I'm a Theatre major), the box would, at best, tumble; however, using pony physics it would fly. And I think that Rainbow with practice could keep the box in the air and avoid touching the ground with it. We learned in the Poison Joke episode that she couldn't fly right with her wings upside down, but she could fly. And, as I recall, it wasn't a case of just smashing into the ground; rather, she had trouble steering. Maybe sort of like the bicycle with the backwards handle? Like, she's got lots of practice flying one way, but learning a new way isn't impossible. [I think that if you somehow put a bird's wings on backwards it could never fly, no matter how hard it tried, but I don't know enough about flight to say that with certainty.]
I mean, the problem here is we're talking about magic and there is no scientifically agreed-upon lingo. I can't remember Kris' explanation exactly, but the idea was that the ship was teleporting fractions of an inch, very frequently (or something like that). And I mention teleportation simply because it's something that we know ponies can do. Also I'm just sort of thinking on this as I type it out, so it's probably going to be a little bit rambly.
If it's just gravity negation, they'd presumably hover just fine (and perhaps they can turn it on and off at will, so that they don't float away when they're on the ground and jump if they don't want to). But that would do nothing about air resistance when they fly.
I learned way back in the day playing around with Microsoft Flight Simulator that if you turn off air resistance entirely (and a few other physics modifications) the airplane more or less turns into a tumbleweed, so you've got to have some or else there's no purpose for the wings at all. If they're steering with their wings--which I think they are, to an extent--there has to be some sort of air resistance but they also have to be overcoming it as well to be moving forwards. So maybe they've got some built-in magical system that makes them go forward a little bit (teleportation) when they make a single flap of the wings the right way. Bank or angle their wings, and they go to the left or the right--it's a curving path. Kind of like they've got a under-tail mounted thruster, really. For hovering, they change their wing angle and maybe are actually sort of flapping backwards to counteract their 'normal' forward movement.
It would have to be, to an extent, a conscious thing, or else there would have been no need for RD to rescue the falling Wonderbolts; they would have just stopped falling. But it also has to work when they sleep, or else cloudhouses would be really impractical. Barring magic from the clouds, of course.
I think that these properties can transmit to whatever the pegasus is physically touching, hence being able to keep a cart levitated or hold on to a piano or whatever, which then turns into a mundane object when a pegasus lets go of it.
4858928
I believe that items attached to pegasi act as though they have no moment arm and pegasi fly through repulsor lifts in their wings. Thus wing motion is largely disconnected from the actual effects of the wings. This explains why RD can have very slow wing beats and still hover in place.
So to answer the question: The box would not fly.
Okay, let's break it down.
1. Pegasi have shown the ability:
(a) to walk on or clouds
(b) to move and manipulate clouds
(c) to form clouds into a material able to hold solid matter
(d) to lift vehicles to which they're attached
(e) to process an unknown material referred to as "rainbows"
(f) to generate lift in excess of what their wings should be capable, evincing what appears to be natural buoyancy
(g) to generate lift with motion that should not have that result, such as single-wing flying
(h) to generate motion in excess of what their wings should be capable, in a way that appears to break conservation of momentum
(i) to generate, through flying, a movement of air sufficient (in numbers) to generate a tornado able to lift water into the air
(j) to withstand substantial physical impact
(k) to effect a release of magical energy into the surrounding area, at the same time as a shift in direction (a "sonic rainboom")
2. While many flying and gliding creatures in the real world are lighter than their terrestrial relatives, due to thinner or more hollow bones, we've regularly seen ponies survive crashes with no injury, and pegasi are no exception
3. I think the evidence is overwhelming that there's some other effect in play than the lift generated by wings acting in air. As depicted, pegasi appear to be both naturally buoyant and able to exert greater force than should be possible.
4. There's also plenty of evidence, both primary and secondary, that the abilities of all the pony tribes are seen to fall under the descriptor of "magic" in their culture. This covers the various abilities of pegasi listed above, and we can safely assume that flight falls under it as well. The show has yet to codify what "magic" is though, and in particular whether the word is used to refer to a specific physical mechanism or simply all such abilities, whatever their nature
5. This does not safely imply any of the following:
(a) pegasus flight, buoyancy, weather control, cloud walking/cloud forming, etc all stem from the same source
(b) these abilities stem from the same source as unicorn, earth pony and other forms of magic
(c) the effect generating lift does not require use of wings
(d) the effect generating lift does not act on the air around a pegasus
6. Presuming as little departure from the laws of physics as we currently understand them as possible, it seems likely that the following basic laws are ultimately obeyed:
(a) conservation of energy
(b) conservation of momentum
(c) total increase of entropy over time
7. The combination of 1(i) and 6(b) implies that the effect generating pegasus flight operates, at least in part, through interaction with the surrounding air. We have no direct way of establishing the scale of this interaction, ie whether it stretches some distance from their body or is restricted to wing surfaces.
Given the above, I would therefore not expect Rainbow Dash to be able to lift a sealed box that contains her.
4858967
Yes. My objection to teleportation is that it involves disappearing in one location – entirely – and appearing in another location. However, if this doesn’t involve negation of acceleration due to gravity, a pegasus with a cart would instantly explode upon landing, due to having accumulated enough momentum to smash clear through the planet and come out on the other side.
And if it does involve negation of acceleration due to gravity, teleportation becomes entirely unnecessary, the effect can be accomplished by that alone.
Why are you thinking of teleportation when acquiring forward momentum through magical means can be accomplished in a huge number of ways, anyway?
Here’s another thing to keep in mind: Rainbow’s lines in Newbie Dash only make sense if pegasi at least can fly like fixed wing aircraft, i.e. have an aerodynamically meaningful tail assembly we don’t see.
As has been noted, it could go either way. Lacking a convenient pegasus to test it, I'm going to have to be part of the "depends on the universe" camp.
4858984
So what would it be in your universe?
4858928
Funnily enough, if I recall correctly, the pegasus attached to a cart also doesn't behave normally:
derpicdn.net/img/view/2014/4/5/592961__safe_edit_edited+screencap_screencap_royal+guard_spike_twilight+sparkle_friendship+is+magic_animated_chariot_guards_scroll_that+friggen+eagle.gif
I mean, for some reason they're waving their legs as if they were running. I thought it was just a S1 weirdness, but there are more scenes like that. Maybe it's some magic supposed to convince the cart that it's still on the ground or something.
4858917
Actually, I'm not sure if the wings do anything with air around them at all. I mean, Sleepless in Ponyville has a scene with Rainbow Dash hovering around the campfire. The fire is perfectly still all the time, even though it should "lie down" on the ground whenever she flaps her wings. Though maybe it's just animators not thinking things through.
On a side note, non-magical explanation for pegasus wings being too small (as well as the fact that in Once Upon a Zeppelin the balloon is way too small to lift that big-ass gondola off the ground, not to mention muscle-powered helicopters being easy to use): whatever planet Equestria is on, it has a much lower gravity than Earth.
4858986
Whatever made for the best story
4858989
They have always been doing that. There is only one exception, during Luna Eclipsed, when they don’t move their legs while they’re diving sharply down, and look more like they’re braking with all four legs – but the chariot is pulled by chains in that particular case, so the entire chain seems to behave like a single solid.
Notice also that the cart wheels, if present, will always be turning while they are moving horizontally.
The major plot point in Top Bolt is that Sky Stinger is not able to reach the acceleration he claims without Vapor Trail giving him a push with her wings, but we don’t know if this works through air as a medium or purely through magic as a medium. We do know that everyone refers to this as “a gust of wind”, but that could mean anything.
Doesn’t work: Free-fall of numerous objects which are not pegasi results in ~1g, give or take 0.1. It would be instantly noticeable to us if it were otherwise, all the animation would feel “wrong.”
My personal theory is that magic provides buoyancy and control, while wings provide thrust, which offers a potential explanation for why Bulk Biceps can fly but Scootaloo can't. Therefore, she still wouldn't be able to move the box unless she managed to produce enough thrust to blast a hole in it- which, since she can fly at supersonic speeds at ground level entirely under her own power, isn't unreasonable to imagine.
That is, she wouldn't be able to propel it forward like normal. She could potentially control the atmosphere inside well enough to turn it into a reaction wheel, and use that to gain at least some control over it. While reaction wheels are generally only used on spacecraft (and at that, generally only on spacecraft that have some particular reason for not being able to use thrusters and don't have things like people that move around inside them. Their most notable use is on telescopes like Hubble and Kepler) where they can only control attitude, the fact that there's air around the box could allow her to use aerodynamics to move the box. It would be a hideously inefficient and awkward way of moving, but it's more than nothing.
Y'all are over thinking this. Here's my headcanon: Magic exists everywhere as an aether of sorts, and when pegasi flap their magical wings, they're pushing against this aether. The box wouldn't fly because the magic would swirl around inside just like air would.
4858989
The animators definitely have forgotten details like that before. In “The Last Roundup”, when AJ powers the cherry conveyor belt by running inside the giant hamster wheel, her regular running animation plays—which has her mane and tail blowing backwards, even though in this scene there’s no wind and she isn’t moving forwards.
At some point, you gotta say some parts are just animation errors, or you’ll go insane trying to make a theory that accommodates every detail.
4858967
From what I recall on my attempts to build an ornithopter, bird wings actually move in a very slight figure-eight rather than a true upstroke/downstroke, changing their angle of attack to minimize drag on the upstroke and maximize lift on the downstroke. From this, and assuming pegasi flap their wings in a manner similar to birds on Earth, it's reasonable to say that flying upside-down would confuse Rainbow's perception of where the angle of attack 'should be', thus screwing up her flight patterns.
Per the question as a whole, everyone seems to be missing (or at least, has moved on from without stating) that pegasi might just be significantly lighter than what we expect, allowing their proportionally smaller wings to generate enough lift all on their own to cause them to fly. While this doesn't account for her being able to fly with a single wing, nor is it explicitly shown in canon (to my knowledge), I would also note this interesting little tidbit from Read it And Weep:
78.media.tumblr.com/28db0df98c225308b96d55615cddd262/tumblr_p8mtakHEKj1t4jo74o1_540.png
Rainbow's wing not only is missing a joint compared to average avian articulation, it's got additional bones extending to the wingtips. This might just be an artistic feature by the animators, but I find it interesting that they wouldn't just show the bone break and leave it at that (unless such would not accurately convey to the viewers that this was Rainbow's wing, and not say, her leg). Compare to a radiograph of a hawk's wing:
todaysveterinarypractice.navc.com/wp-content/uploads/2014/09/Figure-3B.Hawk_.leftwing.radiograph2.jpg
No bones in the wing itself, and three bones instead of just two for the front. It might just be that the third joint is hidden by the animation, as it's rather close to the body and we don't see any traces of the rest of Rainbow's wing, but it's hard to say. I've wondered what this might mean for Rainbow's acrobatic ability - being not only able to change her angle of attack, but presumably (through her 'wing bones') being able to change the cross-section of her wing along its length in three different locations. I know that most birds on Earth can modify this via the means of muscles, but I'm unsure what introducing solid bones would do beyond providing a form of batten or support struts along the wings.
4859034
Yeah. Even in today episode, Rainbow Dash doesn't ruffle AJ's mane when flying around her, but once she flies past her, AJ's mane is blown.
4858995
Aether, maybe?
4859038
Birds in our world are pretty lean and have hollow bones, and that’s how they reduce their weight enough to make flight possible. As 4858976 touched on, pegasi don’t appear any thinner than other other ponies on average (granted, that could just be “cartoon resolution”). And they can recover from high-speed crashes like they’re no big deal, which would seem to be evidence against pegasi having hollow bones. If pegasi are lighter than other ponies, I think they’d have to do it by exotic means.
Suddenly I’m reminded of Laurent Faust’s sarcastic tweets that pegasi can fly because their bodies naturally produce helium.
When Rainbow got zapped by lightning in “Newbie Dash”, her skeleton was briefly visible, and she had bones in her feathers there, too. So I like to think feather bones are an actual feature of pegasus anatomy and not just a visual gag.
Is Luna/Nightmare Moon ever shown flying on the moon by flapping her wings? If so, that would suggest the magic of flight is decoupled from the movement of air, suggesting that the Rainbow Dash in a box could actually fly.
4859375
Considering that this was only ever shown in secondary canon, and when it was, everypony else was breathing on the moon, it’s inconclusive: It’s much more likely that the moon just maintains an atmosphere.
4858976
You skipped the hints of physics implied by "angle of attack" in flight school, but then, "their understanding is wrong" is less of an epistemological drop than "what we are presented is not evidence".
I was very much expecting liquid rainbows to crop up somehow.
Or, on reading, asking whence a rainboom would originate, if Rainbox Dash performed one.
Personally, I feel like pegasus flight (confirmed as magic in Season 4) works by subconsciously manipulating airflow around one's self. Theoretically, a pegasus that can CONSCIOUSLY control this power would be able to fly without using their wings. However, the box is airtight. Assuming she can only manipulate the air around her own body (and not around the box), she wouldn't be able to make it fly.
HOWEVER: the show also displays a large amount of cartoon physics (though most instances are either directly from a Pie family member or bag-of-holding style appearing/disappearing props). Because of these cartoon physics being present, it's THEORETICALLY possible for the cube to fly IF it follows rules like the Rule of Funny or the Rule of Cool.
4859038
Yeah, or for that matter simple muscle memory would be doing the wrong thing . . . there's an experiment on Smarter Every Day where he tries to ride a backwards bicycle, and utterly fails at it. Then with a year of practice, he manages to mostly unlearn how to ride a normal bicycle.
IIRC, you're supposed to do the same kind of thing while rowing, to minimize drag on the oars, and therefore extra work.
While of course we have no canon evidence to say for sure, I'd imagine that pegasi flap their wings similarly to birds in order to fly. Unless it's purely magical flight, and then why do they even need wings?
The atmosphere could also be significantly more dense than ours, which would have a similar effect, at least in terms of wing surface area required to sustain flight.
Also, totally zombie posting.
4873786
Mostly. It’s complicated. If that was the case with no other factors, it would be impossible to fly with your wings upside down, which Rainbow Dash in particular does often, and it would likewise be impossible to fly, and more importantly, remain aloft while stationary with one wing folded. Rainbow, as well as occasionally other pegasi, do this disturbingly often.
It’s some strange combination of purely magical flight, bird-style-flight and surprisingly, fixed wing aircraft flight. The latter is particularly revealed by Rainbow spouting tidbits of flight theory in Newbie Dash, which only apply to fixed wing aircraft. It comes up in other episodes as well.
The exact way these three completely dissimilar modes of flight merge into actual pegasus flight is what makes the above thought experiment interesting, because the way it goes depends on where they meet exactly, and canon does not offer enough evidence to conclude which it is reliably. But if you’re working on a story where pegasus flight is involved in any kind of serious detail, it is important to decide how exactly it works in your particular Equestria.
Not really. Like gravity, we would notice significant changes in pressure very quickly if they existed.
What do you mean “zombie,” I’m still here.
4874033
You know, it's funny but I tend to block that out of my memory. But we have seen that (and wing-hands, too).
I tend to do a combo of bird-like and magic providing an assist to make up for the overly stumpy wings. That, and I ignore any particular bits of canon that probably aren't biologically feasible (like wing-hands). I also tend to not be too specific in what the balance is, because otherwise someone smarter than me will correct me.
But would they? I mean, if Equestria had a denser atmosphere than Earth, would that be obvious from what we see in the show?
I just meant in terms of replying something like two weeks late (had a lot of tabs open, in my defense). Isn't that what the kids these days call it?
4875238
Liquids, for one, would behave very differently if the pressure was different enough to affect flight so much.
The particular term you’re looking for is “necroposting,” I think. Which is frowned upon on forums, where threads typically get sorted by last-posted-into by default. Which is why you can typically find any number of threads rehashing the same thing over and over.
Blogs occasionally just turn off commenting on old posts, because this is often abused for SEO spam, but in general commenting on old blog posts is not a problem otherwise.
4875478
Would they? I know that liquids in a pipe under pressure act a lot differently than fluids in the wild, but if everything is at that pressure, how much difference does it make? My dumb Theatre major self wants to know.
Ah! That's it. I knew it had something to do with things being dead.
4875827
For one, every boiling temperature and every flash point would be different. Which would visibly affect anything that smokes, burns, boils, cooks… and clouds, which would be unable to stay vapor.
4876093
Alright, I can accept that answer.
Having said that, clouds in MLP don't work like IRL clouds.
4876432
Clouds don’t, but vapors and smokes tend to work as they should.
4858910
So, like a Warhammer 40k Ork, it works because they believe it'll work.