* Every single episode of Inspector Gadget contains some variation on the line "If I can just reverse the polarity... There, I got it!"
* Similarly, the cast of Mystery Science Theater 3000 once attempted to shake an alien monster off the satellite with a polarity-reversal maneuver; theirs involved an actual car battery and jumper cables. Also, the alien liked it.
* IQ in the James Bond Jr cartoon also reverses the polarity all the time. He once took control of the badguy's helicopter with a simple remote control and some polarity reversal.
* It also happened in The Real Ghostbusters all the time, and probably plenty of other cartoons where people tinker with electronics.
o A particularly memorable Real Ghostbusters example occurs when some ghosts get their hands on a proton pack -- the standard Ghostbuster weapon -- and try exacting some revenge. With the Ghostbusters busy elsewhere, it falls to the Ghostbusters' secretary Janine to corral the ghosts. She does this by using tools at hand and no formal technical training whatsoever to reverse a second proton pack's polarity so it will neutralize the ghost's weapon. Then, with a small twist of a screwdriver, she re-reverses the polarity and uses the pack to capture the disarmed ghosts.
o In an episode of Extreme Ghostbusters, the team was faced with a ghost that multiplied whenever the proton packs were used against it. They overcame this by converting them into electron packs.
* A popular filk song, "The USS We Make Shit Up" by Voltaire, about the Star Trek series contains a similar line: "Bounce the graviton particle beam / Off the main deflector dish / That's the way we do things, lad / We're making shit up as we wish..."
o In the Star Trek The Original Series episode "That Which Survives", Spock orders Scotty to reverse the polarity of a "magnetic probe". Scotty's incredulous, "reverse polarity?!" is not only Narmtastic, but qualifies as the Trope Namer.
o In Star Trek The Original Series, Spock once did this by "cross-circuiting to B". Same thing.
o On Star Trek The Next Generation, Geordi could make the Enterprise do anything by "routing [some piece of Techno Babble] through the main deflector array".
+ Which almost makes sense, the main deflector array being the largest single antenna on the entire ship. Creative "techno babble", indeed!
o According to the d6 RPG sourcebooks, reversing the polarity in different ways on the main deflector array can create a low power phaser, force someone out of warp, and allow you to basically do ANYTHING you could think of. The Main Deflector Array; Swiss Army Knife of the Federation.
o Wesley Crusher, from the same series, is famous for reversing the polarity on every damn thing.
o Subversion: In "The Samaritan Snare", Geordi subverts this while captured by the Pakleds, who have ordered him to arm them with photon torpedoes or die. He stalls his captors with technobabble until the Enterprise picks up on his plan to vent harmless hydrogen at the Pakled ship. He tells the Pakleds that the Enterprise has disarmed them with its "Crimson Force Field" and they surrender.
o Subversion: In the Star Trek Voyager episode "Drone", Janeway and Seven of Nine thought they could fry a Borg tractor beam by reversing the polarity of Voyager's phaser banks; it looked on-screen like it was about to work, and instead their own phaser array was knocked out.
+ It should be said, however, that Voyager uses this trope like a tentacle demon would a Japanese schoolgirl. However, most of its incarnations feature a "Deflector Pulse" of some sort.
* Used to defeat energy-eating giant square stompy robot in Kurt Neumann's 1957 Sci Fi film Kronos, Destroyer of the Universe.
* The CSI New York Season 1 finale had someone actually "reverse the polarity".
* Justice League episode "Secret Origins": Batman saves the day by "reversing the ion charge" on an alien ship. (This also appeared on the first episode of Challenge of the Superfriends, and very similarly.)
* In episode 17 of the Sakura Taisen TV series, Kohran puzzles over how to make Iris' kohbu properly handle her vast spirit energies, and comes up with an idea that, among other things, reverses the flow of her spirit energy through the regulator crystal.
* In Austin Powers in Goldmember, the tractor beam used by Goldmember and Dr. Evil to pull an asteroid to Earth has "Do not reverse polarity" written on a low-tech-looking panel. When Dr. Evil, having turned good, does reverse the polarity, the beam destroys the asteroid instead of sending it to Earth.
* Subverted in Runaways: Victor Mancha (who is being held captive by the aforementioned group) attempts to escape by threatening Gertrude York with a remote that has had its "polarity reversed". The other Runaways scoff at the idea.
Gertrude: Relax, people. He's a powerless kid holding a remote control.
Victor: I... I flipped this thing's vibranium battery when you weren't looking. If I press one button while the polarity is reversed, it... it won't be pretty.
Molly: Yeah, right. Even I know he's tricking, and I dropped out of the fourth grade.
* Doctor Who, as mentioned above. After a long time of deliberately not using the phrase, the Tenth Doctor has started saying it as an occasional Continuity Nod.
The Doctor: "Really shouldn't take that long to reverse the polarity. Must be out of practice."
o "Doomsday" is one particular example.
o Doctor Who also provides a rare example of polarity reversal not working. When Nyssa and Tegan are rapidly aged every time the Doctor tried to take off the ship in Mawdryn Undead due to... something or other, the Fifth Doctor attempts to reverse the polarity of the neutron flow. This only causes them to de-age into children. Try not to think about it.
o Lampshaded nicely in one of the radio series, The Ghosts of N-Space, in which the Brigadier jokingly suggests that the Doctor "Reverse the polarity of the neutron flow", to which the Doctor replies that the Brig knows as well as he does that the phrase is meaningless.
* The original 80s Transformers movie: Being pursued by Heatseeking Missiles, the fleeing heroes reverse polarities, which apparently causes a sorta energy beam to appear beneath their spaceship. The trope is then subverted because, despite the missiles flying straight through said beam, it has absolutely no effect whatsoever.
o : I think it hada bit of an effect - the missiles didn't actually blow up the ship (sorta exploded in front of it).
* The 2007 Ocean's 13 had Brad Pitt dismissing Don Cheadle's technobabble by saying, "Becomes magnetized, reverse polarization, I know."
* If the characters are hacking, then they reroute the encryptions instead.
o The South Park Movie does this.
* Robert A. Heinlein's novel The Sixth Column features two kinds of Reverse Polarity used with the book's race-specific-Death Ray. The first way turns it in to a health-ray (don't think too hard about that), and the second way lets you use it on non-Asians (I Am Not Making This Up, this is a book about a ray-gun that only kills Asians).
o It was also a story where Asians had invaded and conquered the country of the guys making the ray guns, so you can see what their incentive was to build the thing.
* This troper remembers some Disaster Movie where protagonists had literally reversed the polarity of Earth to prevent the massive doomsday from increased lightning activity over the planet.
o The Core, perhaps?
* The 'Fantastic Four'' movie
* Real Life example- Cars equipped with daytime running lights can be converted to standard lighting (i.e. you can drive with the lights off) by disconnecting the relay. That's it. The headlight switch still works for when you want the lights on.
o This troper wishes he knew that when he was trying the 'jump-start' his car from a Volvo!
* A video game example, in Freedom Force vs. the Third Reich for PC, Sky King is trapped on the other side of a chasm. Bullet, from the future, mentions that in one of Sky King's comic books, he reversed to polarity on his neutrino pack, allowing him to fly (previously his jetpack was too heavy). The current Sky King does this and manages to overcome the pit. Of course, the whole Freedom Force series is about as tropey as a series can be.
* A musical example is in Bob Carlton's -- sorry, William Shakespeare's -- Return to the Forbidden Planet. Before the show starts, the 'crew' or ensemble members walk out and instruct the audience in standard safety procedures for their flight (air masks will deploy from ceiling, use of cell phones will cause the ship to explode, etc.) and end with teaching the audience how to Reverse Polarity themselves -- only for an emergency situation, which is highly unlikely, nigh impossible -- by putting their hands on their heads and twisting their torsos and heads to and fro. In Act II, of course, polarity needs to be reversed ("But it's not logical!" "Damn your logic! I've got lives to save!") and the audience has to help.
o As an added bonus, at the end of the show, as the crew and captain prepare to launch back to Earth (singing Born to Be Wild, of course), crew members announce that all is well by calling "Iambics functioning, Pentameters locked in, Hyperboles all off the scale!" and "R.S.C. jettisoned," injokes all relating to Shakespeare's text, a conceit of language, and the Royal Shakespeare Company, respectively.
o Many of the posters (and T-shirts) for the show consist of a warning sign saying "WARNING: Do not reverse polarity!", and the playbill warns of the dangers of polarity reversal in space. Note that it is never actually specified what the polarity is reversed on, just that polarity in general is reversed - which makes the joke even more tongue-in-cheek...
* Space Cases: Catalina is having some trouble with the concept from her textbook. "Reverse the polarity of the neutron flow? What's that all about?" Aren't Shout Outs fun?
* Batman the Movie (1966): "If I could just... reverse the polarity... send out waves... of super-energy!" Highly effective on torpedoes until... "Confound it! The battery is dead!"
* In the 1952 British film The Sound Barrier. the hero solved the problem of controlling a supersonic airplane by reversing the flight controls. To increase lift, for example, he pushed the stick forward instead of back as would be expected. The movie does not state whether this also held true for the engine: would you apply more throttle if you wanted less forward thrust? In any case, Major General Chuck Yeager, the man who was actually the first to fly an airplane faster than sound, was asked about this and stated that any such method would result in the pilot's death. (In reality, the problem of lack of control in the transonic range was solved in a straightforward manner by creating much larger control surfaces.)
* In the Kim Possible episode "Clean Slate", reversing the polarity on a memory-enhancement device causes it to erase Kim Possible's memories.
* At least, Narbonic's Genre Savvy Dave Davenport knows he's appealing to the Theory Of Narrative Causality: "Sometimes it helps, for some reason?".
* Video Game: It turns this is the way to reconnect Clockwerk's body in Sly 2.
* In The Tick Vs Reno, Nevada, Arthur is asked to reverse the polarity on a fish magnet. He finds two cables, blue and red, and a box with two similar a big label saying "Observe Correct Polarity. Use AC current", and two coloured sockets. Arthur puts the cables in the wrong sockets, which seems to work, despite the obvious AC current issue.
* In the original Spy Kids film, the heroes force a Heel Face Turn of the titular Spy Kids robots by reversing their alignment polarity. He does this by inverting the binary code. While it probably would stop the robots from attacking, they would be more likely to crash then turn good. Of course, you can Never Say Die in a kids film, so...
* If you pay attention you'll notice that in Young Frankenstein, reversing the polarity is the secret to re-animating dead flesh.
* This once happened in Pokemon when Team Rocket tried to get hold of two Luvdisk, and then reverse the polarity to get rid of all of the love in the world.
* Paul Chuckle is always using this in Chucklevision. At one point he reverses the polarity of a uv light (which helps plants grow) to shrink his brother Barry.
http://tvtropes.org/pmwiki/pmw...p/Main/ReversePolarity