Shrink Ray

"Amy: How can we be in here? How do we fit?

Rory: Miniaturisation ray.

Amy: How would you know that?

Rory: Well, there was a ray, and then we were miniaturised."

- Doctor Who

Examples in various media of a ray (a portable gun or a fixed installation) which can be used to shrink things (or, in some cases, alternately to expand things, probably by reversing the beam polarity). Has been subjected to Science Marches On and is a Discredited Trope; examples that do appear these days are more or less humorous.

Most (not necessarily all) such are usually typified by one or more of the following:
 * 1) The shrunk object doesn't need to be unshrunk; this happens automatically (indeed, it can't be prevented).
 * 2) The further something is shrunk, the less time it remains shrunk.
 * 3) The mass of the object changes in proportion to the size change (well, to be pedantic, in proportion to the cube of the size change).
 * 4) Shrunk objects are more fragile than objects which are naturally of that size; this was handwaved in Fantastic Voyage as being because shrunk objects have loads of miniature atoms crammed into the space normally occupied by one atom.
 * 5) Shrunk/expanded items, even living creatures, continue to function as normal. (As anyone who's read Haldane's famous essay "On Being the Right Size", about the Square-Cube Law, knows, this is unrealistic; any living creature changed in size by more than a small extent would die in short order, due to being the wrong size for its shape.)

See also Incredible Shrinking Man, No Conservation of Mass, Shapeshifter Baggage.

Advertising

 * A commercial for Ratchet and Clank Size Matters shows a bunch of guys using one of these in the woods so that one of them can shrink and sneak into the girls' tent. Unfortunately, they didn't take the owls into consideration...

Anime and Manga

 * One of the recurring gadgets in Doraemon is a "Small Light". A flashlight-like shrink ray which shrinks any object and person down and does wear out eventually as seen in one movie. There's also a "Big Light" which does the opposite.

Comic Books

 * In Silver Age DC Comics, Superman had one that could be used to allow people to enter the bottled city of Kandor (which was originally shrunk by Brainiac using a shrink ray).
 * Pym Particles in the Marvel Universe, which can shrink and grow things. Discovered by Hank Pym, used to turn himself into Ant Man, Giant Man, Golaith and other characters.
 * In All Fall Down, the Order of Despots has one on the Moon, and threaten to shrink the Earth with it. It comes up again later as a possible solution to a Colony Drop-sized asteroid.
 * 1980's British Starblazer. The Matter Condensor could shrink a cargo to a fraction of its normal size, enabling a small freighter to carry much more. Upon arrival the process was reversed.

Film

 * Honey I Shrunk the Kids hits two of the above points — the mass of everything that's shrunk is reduced, and living creatures function perfectly normally. On the other hand, everything that's shrunk has to be manually unshrunk by the same machine, and they're no more fragile than at normal size.
 * Note that non-shrunken characters do take care to never touch the shrunken ones.
 * Fantastic Voyage features a submarine crewed by surgeons which is sent into a scientist's brain to destroy a blood clot from the inside.
 * Despicable Me has Gru plotting to use a shrink ray to steal the moon.
 * Mars Attacks!: The Martian leader uses one on General Decker, then squashes the general under his boot.
 * Attack of the Puppet People: The puppet people don't actually attack. They've been shrunk by a puppeteer.
 * Once Upon a Spy: The Big Bad has a device that can fire a beam that shrinks large objects (like an aircraft carrier) down to the size of toys. He ends up being shrunk by his own device.
 * Not a ray, but The Devil Doll featured a shrinkage-inducing chemical process that reduced people or animals to the size of toys. Could be the Ur Example, from 1936.
 * Willy Wonka and The Chocolate Factory. The Wonkavision TV camera that shrinks both a giant candy bar and Mike Teevee

Literature

 * In Animorphs, the ant-sized Helmacrons use a shrink ray to shrink the Animorphs down to their size.
 * Captain Underpants has the Shrinky-Pig 2000, invented by Professor Poopypants. He also invented the Goosy-Grow 4000.
 * The Stainless Steel Rat For President has Jim diGriz and his team carry items of miniaturised equipment, plus a shrinker/expander. Features only the "mass change" item above.
 * The Size Spies by Jan Needle features a shrink ray created by an eccentric inventor, then stolen from its inventor.
 * The Harry Potter books feature the spell "Reducio", which has this effect. Not to be confused with "Reducto" which causes them to explode instead.
 * In L'Homme Élastique by Jacques Spitz, a scientist invents a nearly realistic version: it shows shrunk (or enlarged) beings live just as well as regular ones, but at least it acknowledges the problem and tries to Hand Wave it. Notably, mass is conserved, and the scientist gains the attention of the Army when he shows that miniaturized soldiers are tiny, hyperdense juggernauts.

Live Action TV

 * Sid and Marty Krofft Productions had an episodic kids' show called Dr. Shrinker in The Seventies, in which five or six people were shrunk down to less than six inches.
 * Doctor Who:
 * The Master was armed in many of his appearances with a ray gun called the Tissue Compression Eliminator, which simultaneously killed the target and shrank the corpse down to a convenient-to-dispose-of size. It kept the rule about shrunk objects having less mass, but mostly averted the one about living creatures surviving the process.
 * "The Invisible Enemy" includes a Fantastic Voyage Plot (using a shrink ray based on the same technology as lets the TARDIS be bigger on the inside, allowing a bit of handwaving about the issues of shrinking living things).
 * "The Armageddon Factor", by the same writers, had another shrink ray based on the same technology, built by a Time Lord friend of the Doctor's so the two of them could shrink down and hitch a lift into the villain's base.
 * Lampshaded in "Let's Kill Hitler". The episode featured a robot that can shrink people and transport them inside itself. When Amy and Rory are captured, Rory explains that they were hit by a "miniaturisation ray" because "Well, there was a ray, and then we were miniaturized."
 * The Avengers episode "Mission...Highly Improbable" has a device that sends out a ray that shrinks objects or people down to the size of toys.
 * An episode of Eureka featured a ray designed to shrink small inanimate objects by shunting most of their mass to an alternate dimension. Only... it was miscalibrated, and accidentally shrunk the entire town. Humans thus shrunk were still capable of functioning normally, other than being unusually hungry.
 * The Farscape episode "I Shrink Therefore I Am" included several members of Moya's crew being shrunk down by bounty hunters and then stored in small canisters within their armour, but otherwise unharmed. The criticisms of this trope were lampshaded when Sikozu attempted to deny it'd happened by explaining why it was impossible, and Rygel pointed out that it had happened even if she couldn't understand how.

Tabletop RPG

 * GURPS Supers. The Shrinking power can be given the advantage Affects Others, allowing it to act as this.
 * The supplement Supertemps. The hero Nucleus' nanosuit can generate a shrink field that affects other living beings.
 * Champions. When the power Shrinking is given the advantage Usable On Others it works as one of these.

Video Games

 * In the ZX Spectrum game "The Incredible Shrinking Fireman", the titular character, whilst fighting a blaze at a factory, accidentally gets zapped by a shrink ray and must find a way to expand back to full size.
 * Duke Nukem 3D has one that shrinks your enemies for a short time. You then have to step on them, or they return to their original size. There's a one point where you can aim at a mirror and shrink yourself to pass through a small hole into a room full of power ups. There's also at least two points involving wall-mounted shrink rays which Duke has to use to pass through a tiny hole and thereby finish the level, and one of the new enemies in the fourth episode of the Atomic Edition has a shrink ray as one of its weapons.
 * One type of Kanoka disk in Bionicle has the ability to shrink the target.
 * The Purple Tentacle in Day of the Tentacle invented one of these, and used it on the heroes while chasing them. They finally convince him to take out his anger on Dr. Fred instead, but the ray is reflected on his medical headband onto Purple, and that's how they manage to defeat him.
 * Command and Conquer Red Alert 3: The Strong Homogenous Residual-Interactive Neutron Kinetic beam of the allied Cryocopter.
 * The unmodified de-noodlizer in Parappa the Rapper 2 can shrink or enlarge characters (including Parappa) when a certain character presses the button on its remote control, even with help from the Guru Ant, of course.

Western Animation
"I'll make you fun-sized!"
 * Hanna-Barbera
 * In Micro Ventures, a segment on The Banana Splits show, Professor Carter and his two teenagers use a shrinking machine to reduce themselves and their dune buggy to miniature size and explore a Mouse World.
 * Superfriends 1973/74 episode "Gulliver's Gigantic Goof''. The villain Dr. Hiram Gulliver uses one on the Superfriends.
 * Space Ghost episode "The Evil Collector". The title villain uses a "minibeam" on Space Ghost, Jan and Jace.
 * Birdman episode "The Ant Ape". Dr. Claw tries to use his Ultra Diminishing Ray pistol on Birdman but hits the Ant Ape instead.
 * In a Simpsons Treehouse of Horror episode, the tiny people that Lisa grew made a "debigulator" which shrank Lisa down to their size so she could visit their world. Their world's version of Professor Frink found the concept of a "rebigulator" to be rediculous.
 * On The Penguins of Madagascar, Kowalski mentions that they are 700 years from perfecting a shrink ray (712 after Skipper destroys the prototype). In a later episode, Kowalski has a working shrink ray, but although the results are shown, you never actually see him use it.
 * Naturally, Dexter of ~Dexter's Laboratory~ has one, and in one occasion he uses it to shrink himself and spy on Dee Dee.
 * Phineas and Ferb do this twice. Once shrinking themselves in a submarine that ends up in Candace, and again later shrinking along with friends to play hide and seek inside.
 * Gerry Anderson's lesser-known (and last) Supermarionation series The Secret Service features a shrink ray that Father Unwin uses to shrink secret agent Matthew to two feet tall. This allows Matthew to infiltrate the enemy's hideouts and learn their plans (allowing the 2-foot tall marionette to appear in full-size sets, occasionally hiding from full-size human arms and legs, or pets). It can also be used to literally bring the enemy down to size.
 * SpongeBob SquarePants featured the shrink ray twice:
 * Once when SpongeBob accidentally shrinks the entire town with Mermaidman's Utility Belt.
 * Once in a Fantastic Voyage Plot involving Squidward swallowing his reed.
 * In the Kim Possible episode "Rufus vs. Commodore Puddles", Dr Draken planned to use one to infiltrate Area 51. It ended up enlarging his dog instead.
 * The Venture Brothers utilizes Dr. Jonas Venture's shrink ray several times. It first appeared in the Magic Versus Science competition between Dr. Venture and Dr. Orpheus to see who could successfully shrink someone. (They both fail.) In another episode, it was used to shrink SPHINX's submarine so it could be used in a Fantastic Voyage Plot.
 * One of the many features of The Magic School Bus. Ms. Frizzle also has a portable version, called the "Porta-Shrinker".
 * In the Cartoon Network Groovies episode "Dee Dee and Dexter" (Dexter's Laboratory anime style), Dexter uses a pistol-like device to shrink Dee Dee.
 * One is used on The Herculoids in the episode "Tiny World Of Terror."
 * This is Reducto's villain schtick in Harvey Birdman.


 * Filmation The New Adventures of Superman episodes
 * "Superman Meets Brainiac". Braniac uses a pistol-shaped device to shrink circus animals to tiny size so he can steal them.
 * "APE Strikes Again". Braniac uses his device to shrink a scientist and Perry White.
 * "The Return of Brainiac". Braniac shrinks Jimmy Olson, Lois Lane and Superman.
 * "Brainiac's Bubbles". Dr. Hekla (?), Brainac's master, tries to use on on Superman but fails.
 * "The Cage of Glass". Brainiac shrinks an entire town for the purpose of repopulating the planet Mega.
 * In the Eek the Cat episode "Honey, I Shrunk the Cat", Elmo the elk invented one so he can shrink a watermelon. But he accidentally shrinks both Eek and Sharky (who crash into the melon) instead.
 * The 1968-69 Filmation Fantastic Voyage cartoon was based on the 1966 film. It had a large facility with three large devices generating energy beams that shrank the flying submarine Voyager and its crew.