Pegasus Magic

So I've been watching season 1 with a friend recently. He'd shy away from calling himself a brony because of the implications, but he's definitely a fan of the show. We worked up to "Sonic Rainboom" and spent a while discussing the nature of the titular event. Well, mostly it was me explaining my long-winded theories. I've decided to write those down, since it's unlikely I'll be able to go over these ideas so extensively within a fic.

I will first off provide an explanation for magic that is compatible with show canon, even if not directly supported, and in fitting with my own works. I will then extend this definition of magic to non-unicorns. Finally, we will discuss the specific case of the Sonic Rainboom. Note that I shall operate entirely from within the canon of the show and avoid making excuses based off of the fallibility of the source material.

Firstly, most followers will understand my concept of magic from Spark, much as I loathe the piece itself. The ideas I put forth in it, however, I still mostly support. Magic to me is a primal form of energy located on a separate "plane". For those unfamiliar, a plane can be thought of in a geometric sense. It can be described by a set of equations (the physics of the plane), and can be infinite in size and still possible to move off of. Only certain things (geometrically, points or lines) can exist in a given plane, and are determined by the relevant equations of the plane. The analogy breaks down somewhat in interplanar interactions, in which case we can revise said analogy so that planes are more like geometric surfaces. Two surfaces can intersect in complex ways, and can even be locally manipulated to cause an intersection, though this requires modification of equations. Surfaces, and planes, can even be "patchwork", where different equations apply in different locations.

The point of this is that the performing of magic is something of an energy transfer between planes. It is a forced intersect so that things on one plane can play by a different set of rules/equations. And these are where spells come from. A unicorn's spell is the introduction of a new set of rules for physics. This can cause effects such as levitation, transmutation, growth, alteration, etcetera. The exact effect can be attributed to exactly how the fields involved are manipulated, what universal laws are overwritten. The glow of magic I will say is a side effect of this disruption, because it fits in with my next important point; the horn as a catalyst for magic.

Obviously accessing this plane of magic would not be trivial. Despite the surfaces analogy, "space" between planes doesn't make sense and instead planes could be thought as all existing next to one another (though I have no theories about ordering of planes and whether direct access would always be possible; that is something I've given no thought since currently, only 2 planes of existence are relevant) and separated by a barrier of sorts. This barrier could just be where the planes end, or more likely it is some sort of entity in of itself, perhaps a type of energy or even miniature plane that keeps planes separate. My point for this is that there is an energy requirement for plane interaction. We have seen that spellcasting requires energy, and the more pronounced the spell's effect the more energy it takes (as an aside, this explains the ubiquity of levitation, as gravity is an exceptionally weak force and probably takes only very limited access to the plane of magic to achieve). The reason for this is admittedly not self-evident from my proposed scheme, but it is self-consistent. It must be possible to, in a way, tug the plane of magic (locally) into what we'll call the mundane plane. This supposes a kind of non-magical manipulation, but I don't consider that to be ruled out. To me gravity provides a perfect analogy. The existence of mass causes a warping of spacetime, a manipulation of the fabric of the universe (or, as we care about, the plane). The existence of energy, perhaps specifically a kind of energy biological life produces, could produce a similar effect. "Life energy", for short, though I do not mean for it to sound mystical - energy can take all sorts of forms from electrical to heat. Perhaps the form found in neurological functions would do nicely. The horn is thus a logical way of producing magic, one that makes sense from an evolutionary standpoint. In the way that a black hole produces such a sharp warp of gravity our understanding of physics break down, but much less drastically, the horn focuses the relevant energy to enough of a point that the warping of the plane causes it to intersect the plane of magic. As stated earlier, a more pronounced effect would require a larger intersection with the plane of magic, so a "pinhole" tear in the barrier could produce levitation, whereas a much larger gap would allow the transmutation of a rock into a hat or such. As for the specifics of the spell, I would imagine the warping could be customized to great extent by specific regulation of focus and energy levels within the horn. The relatively limited magic of most unicorns becomes apparent in the internal structure of the horn developing according to what specific patterns of energy modulation it is required to perform; like the difference in musculature of a marathon runner and a sprinter. A unicorn like Twilight would have to, likely through a combination of genetics and training, produce a more generalized internal structure that allows her to perform a variety of spells, much like those few people who through meditation and training can control their bodies so precisely.

With this in mind, we can extend the use of magic beyond unicorns. The existence of pegasus magic is evident foremost by the spell-like abilities of their kind, such as the ability to treat clouds as solid objects, a feat we know for a fact can be reproduced via a spell (Twilight, in "Sonic Rainboom" finds a spell to let non-pegasus ponies walk on clouds). Furthermore pegasus flight only makes sense if magic is introduced into the equation; even with hollow bones and low body fat, a pony of that size would be no more able to fly than a human flapping their arms. However, if wings were something like less-developed horns, specialized to partially neutralize gravity or produce additional lift, then flight makes sense. The lack of a glow can be attributed to the low and diffuse level of planar manipulation that occurs. Beyond that, effects at increased speeds such as the unique trails pegasus ponies can leave (Dash's rainbow, one of the Wonderbolts' leaving behind lightning-filled clouds) can be explained as side effects of the increased magical output. Variation in ability is as sensible as it is for unicorns, the result of genes and training, and things like Fluttershy's cart in "Feeling Pinkie Keen" can be explained as not enchanted, which by common sense would be an extremely resource-expensive achievement, but as a pegasus "spell".

With all this in mind the Sonic Rainboom is barely worth mentioning. I believe it actually has no relation to breaking the sound barrier, though it could be. What is actually happening, to get a little less formal, is that Dash is tearing this interplanar barrier a new one. The horn of a unicorn focuses their life energy to cause a localized, and conscious planar intersection. Dash, however, is producing such a build up of energy as she attempts to produce more and more propulsion per wing-stroke that she is causing a massive planar intersect with her entire body as the focal point. The only specific manipulation is intrinsic; for Rainbow Dash it manifests as a wave of rainbow energy, but it could be for Spitfire that a similar feat would produce fire, or so on. The shockwave effect is natural from the sudden influx of magical energy, but because it is Dash herself causing this planar interaction, the effect follows her, becoming stable after the initial rush of energy (it is likely that a local equilibrium is reached, explaining why she produces one shockwave) to produce the lasting rainbow trail observed.

As a final thought, this suggests that non-unicorn magic will be subtler because any accesses to the plane of magic by non-unicorns would be gentler, more gradual instead of a sudden energy spike - the difference between dipping your toe in the water before easing in, and doing a cannonball. It does not imply that it necessarily has to be an active spell either, as there can be light interactions between planes (two planes barely interacting, or interacting at points where the barrier is thin because, like two geometric planes, perhaps their equations meet up). Physical feats are more likely since non-unicorns have no apparent way to focus their life energy, but it is possible that there exists some way to do so, even if it is for some specialized effect like the pegasus wing.