Wave Motion Tuning Fork

A specific kind of Energy Weapon consisting of two or more prongs separated by an empty space. The blast from this type of weapon is generated within the space or fired through it, often heralded by crackling streams of energy zipping between the prongs as the weapon charges.

How the energy being charged does not simply disperse into the air is never really touched upon, although, one can expect a Hand Wave along the lines of a magnet did it. Suffice to say, the audience shouldn't even feel compelled to question this logic, because it looks really freaking awesome. And when you're that awed, things like reality just aren't important.

Some times a regular, less powerful weapon may be able to open up into one of these for a truly staggering blast, which is where this trope gets its name.

Note that while most magnetic acceleration weapons (railguns) have this kind of structure internally, they do not count. This trope is for energy or gas firing weapons... which could actually be something called a "plasma armature railgun" that's more interested in a plasma beam than using hot plasma to accelerate a projectile...

Examples of Wave Motion Tuning Fork include:

The larger energy weapons in the Macross series (and by extension Robotech) are of this design. Some of the ships of the titular class even used the arms of a Humongous Mecha mode as "prongs".
- The Trope Codifier was the original Super Dimension Fortress Macross itself , whose bow separated to form its Wave Motion Gun.
  - The Zentraedi ship-mounted smaller cannon also had a sort of baby-version of this look to them.
- Macross Frontier gives us a private military version of the SDF called the Macross Quarter. About 1/4 the size of Battle Frontier, she carries a Heavy Quantum Cannon. This tri-prong, splitting weapon of mass destruction is new in the pantheon of Macross wonder weapons that, though not as powerful as Battle Frontier's Wave Motion Gun, it still has enough power to take out a Vajra battle ship half, even a little more it's own size. The beams cycle down the the "rail-gun" structure and seem to "twist" into a single beam when fired.
- Also in Macross Frontier, we have one of the most advanced VF, the VF-27 Lucifer, with a smaller version of the Heavy Quantum Cannon. The gun splits into a dual-prong energy "rail-gun" that takes a cue from its bigger brother armed on the Quarter. While not as obviously powerful, it can take out a medium sized Vajra with one shot.
  - The second movie gave the YF-29 Durandal, which has one similar to the VF-27's, only it opens vertically instead of horizontally.
    - The Quantam Cannons used in Frontier deviate from the original trope. Inside of firing a beam from between the prongs, each prong fires its own beam which then converges together into a spiraling beam.
Armored Core 2 has a dual Arm Cannon version as a Shout-Out, but the effect is less like a Wave Motion Gun and more like a barrage of plasma bolts.
In Fafner in the Azure: Dead Agressor and its prequel movie, a number of the energy weapons exhibit this feature, being swords that split down the middle to fire energy blasts. The practical purpose of this feature is shown by the separating halves of the blade creating a hole in an enemy's force field through which a shot can be fired.
Raising Heart does this. The explanation is simple.
- Bureau L-class spaceships also have a tuning fork structure on the prow, and once the Asura gets upgraded with the Arc-en-Ciel...
Done a number of times in the various Gundam series:
- The Nu Gundam's Fin Funnels work this way, and can also generate a beam shield as needed.
- Tallgeese III's megacannon, which has variable power modes. In maximum output mode, the form that uses the Tuning Fork, its power output is roughly equal to Wing Zero's Twin Buster Rifle, but It Only Works Once; afterwards Tallgeese is drained of power and needs assistance to get back to functional.
- Gundam Virtue's GN Bazooka (pictured) would split and extend for its Full Burst Mode. Later on, the Gadessa sported a three-barrelled variant that could separate the barrels to form a weapon of this type.
  - so is Virtue's later generation, Seravee Gundam, which can launch an Energy Ball.
The Covenant Plasma Rifle and Plasma Pistol, and the Brute Plasma Rifle from the Halo series. As might be expected, their workings have raised quite a bit of speculation but one of the more prominent ones is that the prongs supercharge air molecules between them and accelerate the resulting plasma out with a magnetic field. Better to just play the game.
- The "Seldom explained" bit is justified in that the Covenant have looted the remains of the extinct Forerunner civilization for their technology. The Covenant don't understand how it works because they believe the items to be of holy origin (they worship the Forerunner as gods.) The Humans don't understand how it works because they're not anywhere near advanced enough to have anything like it.
Haken's Hand Cannon opens up like this during his Limit Break in Super Robot Wars OG Saga: Endless Frontier Notable in that the actual barrel of the pistol remains between the prongs.
Tau railguns in Warhammer 40,000 look like this, but normal pulse weapons have a case around the rails.
In Super Robot Wars Advance, the Ash Saver's Halberd Launcher is a Personal Trooper version of this, firing a main beam and several side beams at the target.
Digimon has two of these: Beelzemon's gun opens in such a manner before firing, and the lion head design on Lowemon's chest can do a fairly unusual version of it (the mouth opens, and a sphere of black energy swirls into existence between the jaws. A yellow beam is then fired from deep inside the mouth, through the black sphere, and the enemy is struck with a black-and-yellow blast. It looks a lot cooler than it sounds.)
The Van and Aerotank (and presumably the dumbed out Van Leader) enemies in Phantasy Star II have a variation on this: the large, vertical "slab" in front rotates 90 degrees, opens sideways, a crackling of energy is seen inside, and it launches an energy blast.
The Lightning Gun from Quake and Quake III Arena.
The Oratorio #8 Kill Sat in Eureka Seven.
The nose of the Vic Viper from Gradius is shaped like this, and is even used as such in some art/adaptations.
The wing-mounted beam cannons from the Knight Sabers' gunship in Bubblegum Crash!
D'Argo's qualta sword from Farscape is a fairly well-justified example; it's a normal sword most of the time, but he can open it up, forming a gun of roughly this configuration; there's a barrel at the back end, and the "prongs" don't seem to do anything when it's a gun; seeing as they're the sword blade, they're still fairly useful.
Homeworld makes good use of this:
- Homeworld and Homeworld: Cataclysm: the Taiidani Sajuuk Cor Ion Frigate has a forward-mounted ion cannon that sports not two but four accelerator units around its axis.
- Homeworld 2: the Sajuuk actually inverts this trope in that the weapon is composed of two angular trenches running across the sides of the entire ship and the vertical fork on the front which is only the muzzle. When the weapon fires, a golden-orange energy stream fills the trenches from the rear to the front; when the stream reaches the fork, anything that happens to be less than ten kilometres in front of it is dead.
The Artemis from My-HiME uses this for its main weapon
In MARDEK 2, the Dracelon boss monster has one as a claw. The two prongs also open out to 180° when it uses its Lightning Storm attack.
As mentioned on the Wave Motion Gun page, Larry Niven's 1985 novel "Ringworld Engineers" presents an early version of this trope in the Wunderland Treatymaker, a Kill Sat just short of Death Star class. It fired a parallel pair of beams—one to suppress the negative charge on sub-atomic particles such as electrons, while the other suppressed the positive charge on particles like protons. Between them they generated an incredible electrical potential, and in turn enough electrical current to melt and then vaporize rock. The only time it was used on a planet, the result of dragging its beams across the planet's surface resulted in a canyon twenty miles across and twelve miles deep, and nearly two hundred long.
The mass relays from Mass Effect fit the "tuning fork" description, even though they're not weapons. Though given their importance to pan-galactic travel, they could be considered a delivery system. And they are an important component in the Reapers' cycle of destruction.
- On the other hand, they could fit this trope completely if used to deliver a nuke to destroy the mass relay on the other end. While relays are ridiculously tough, if one does go up the result is quite spectacular.
Megatron's first transmetal form in Beast Wars has him equipped with a two-pronged arm cannon. That glows purple.
The Bullet Hell arcade game Cyvern has the green dragon, who fires the beam from prongs on its wings.
In later Virtual On games, the Temjin exhibits this, with its beam rifle's barrel splitting open to allow it to fire a supercharged shot. Given that the rifle is not only also its sword, but a flying surfboard too, this raises one or two questions about the weapon designers in that game...
In a much smaller scale, the Street Hawk motorcycle's nose-mounted laser.
The GUTS Wing 2 planes from Ultraman Tiga and Ultraman Dyna.
An unused concept sketch for a Transformers/G.I. Joe crossover was of Megatron with an alternated move of a Cobra Helicopter/tank. The vehicle's three rotors formed a Shoulder Cannon in robot mode.
A Miracle of Science: Benjamin's railgun is a (large) pistol-sized example. The Martian Cadence Lance is also fired from between two prongs, though they form a notch in a semicircle rather than being linear rails.
Warp Rifles in UFO: Aftershock.
Trinity Blood: When Abel cranks the Crusnik up to 80%, his wings act as one of these. It is awesome.
The D-Rex boss in Mega Man X has a weapon like this.
The railgun that blasts apart Devastator in Transformers: Revenge of the Fallen fires from a two-pronged turret.