Someone uses a magnifying glass or similar optical instrument to concentrate sunlight to kill, burn, or melt something. This may take a few different forms.
Children at play may experiment with using setting fires or killing small insects with a magnifying glass. At times this may be used to demonstrate that the child is an Enfant Terrible, or (in works written from the perspective of the insect) that Humans Are Cthulhu. On the other hand, sometimes children who do this are just portrayed as scientifically curious.
In some cases, a larger lens may be used as an Improvised Weapon. Many attempts at this both fictional and real are inspired by the story that the ancient Greek scientist and engineer Archimedes used this sort of contrivance to destroy a Roman fleet during the 214-212 BCE Siege of Syracuse. Supposedly, he focused the rays of the sun using an array of polished shields, mirrors, or lenses. (Sadly, MythBusters tested this example of the trope three times and found it less-than-effective.)
This trope may seem fairly modern but it's in fact Older Than Feudalism. In Aristophanes' ancient Greek comedy The Clouds, the gods use a set of mirrors or lenses to ignite the Olympic Torch (a smaller device traditionally lights the torch for the running in modern days).
Also this is Truth in Television. It works, but not as quickly as usually depicted.
- Used by Nova Shenron in Dragon Ball GT. He summons a giant lens and use it to fire an extremely hot sunbeam.
- In Bodacious Space Pirates, the Odette II is being fired upon by a pirate ship using optical targeting. Marika reconfigures the solar sails to reflect Tau Ceti's sunlight directly onto the pirate ship, blinding their spotter and heating the hull. She stops just short of melting the ship.
- Mobile Suit Gundam has the Solar System, a superweapon wielded by The Federation that is a scaled-up version of the old Archimedes "Death Ray". In this case it's somewhat more plausible, because the array consists of four million mirrors, each the size of a small building, and they're all aimed by computers. Mobile Suit Gundam 0083: Stardust Memory introduces the Solar System II, which is much more efficient thanks to better materials and targeting software, meaning it can achieve the same destructive power with only 408,000 mirrors.
- The Red Stone of Aja from JoJo's Bizarre Adventure: Battle Tendency has this effect. Putting it up-to a light source will cause it to reflect the light a million times and emit it out the opposite side as laser. This can also be used to power up the Stone Mask to turn a Pillar Man into the Ultimate Lifeform. The Stone is also able to amplify the Ripple, since it's basically solar energy.
- Caeser Zeppeli uses this trope with bubbles to reflect light from outside a castle to the inside at Wamuu.
- An unintentional version happens in Jo Jos Bizarre Adventure Diamond Is Unbreakable, where Rohan leaves a magnifying glass on a newspaper and ends up starting a fire that does quite a bit of damage to his house. He ends up blaming Josuke for it because they were gambling at the time and Rohan was so fixated on finding out how Josuke was cheating that he didn't notice the fire until a third party pointed it out.
- Golden Wind has a sequence where the protagonists use this for a Jack Bauer Interrogation, using a pair of glasses to focus the sun's rays right on his eyeball. And then they mock him by dancing in front of him.
- A filler villain in Naruto had the ability to create a giant lens to fry people with.
- Nichijou; in one scene, Mai and Mio ask Yuuko if they can borrow her eraser. Yuuko has them guess which hand she has the eraser in, and after a few missteps Mai pulls out a magnifying glass to burn the back of Yuuko's hand, which she promptly declares as cheating.
- Dr. Stone deconstructs the idea during the Tournament Arc. Chrome ends up faced off against Magma and has no hope of winning in a straight fight, so he uses a pair of glasses that were left on the arena floor to try and light Magma's clothes on fire. It takes a massive string of contrivances to work — since eyeglass lenses are concave, Chrome has to fill them with his own sweat and tears to create a convex lens, then hold absolutely still to keep from disturbing the surface of the water. Likewise Magma needs to be held in place for 60 seconds, so Gen claims that he cast a spell that will make Magma's heart explode if he moves a muscle, adding that he can only maintain the spell for one minute. The plan works perfectly because Magma buys the bluff completely and because Chrome's dedication to saving the woman he loves allows him to stay stock-still and keep the water "lens" from breaking.
- In Pleasant Goat and Big Big Wolf: Joys of Seasons episode 1, Wolffy tries to use a magnifying glass to light his cannon after the goats use water guns to extinguish his lighter. It suddenly becomes night before he can get it to work.
- Bill Engvall talks about what a great day it was when you discovered you could do this as a kid ("You got to be God!"). Then he goes on to talk about when he was doing this and saw an ant on his arm...
Bill Engvall: Let me tell you something: you burn your arm with a magnifying glass, you're on your own. You can't even tell your mom, because she gives that face like, "Oh...he is that stupid."
- Adam Strange of the DC Universe fought one of these on a gigantic scale as a Monster of the Week in his Strange Adventures appearances. He does so again in Batman: The Brave and the Bold but with Batman and Aquaman's help.
- In one old (1960s/1970s) Green Lantern comic, the villain used a giant flying magnifying glass as a weapon to burn his opponents. He used time travel to acquire it.
- In the Tintin book Prisoners of the Sun, that's how the Incas plan to light the fire that will burn the protagonists at the stake.
- When Lobo got The Mask, he went on a galaxy-shaking rampage of random violence, at one point doing this to people of some unfortunate planet.
- In one issue of Marvel Adventures Spider-Man, Doctor Doom builds a flying ring base whose center is actually a giant magnifying glass. However, he doesn't unleash it at once, instead opening its shutters slowly and making everyone suffer from increased heat. Spidey's able to stop him, though.
- This is the supervillian's plan, coupled with a reagent that reacts to filtered light, in the Batman comic Messiah of the Crimson Sun.
- The early Thorgal story "The Fall of Brek Zarith" has the current lord of the titular fortress destroy half an invading Viking fleet with Archimedes-inspired mirrors.
- In a Superman story, Superman is feeling sick and uses giant magnifying glasses to focus the suns rays onto him. Since he's powered by the sun, it gives him a needed boost of energy.
- In Watchmen, one of the souvenirs in the Minutemen's clubhouse is "Moloch's Solar Mirror Weapon". It's not seen in use until one of the prequel comics.
- A Calvin and Hobbes strip had Stupendous Man use a giant magnifying glass from an observatory telescope in order to fry Calvin's school off the map. Of course, since it was all in Calvin's imagination, his Mom doesn't believe him when he says that the school got fried, and has him do his math homework.
- The Far Side: Two ants are on their hill, one of them saying "Now I'm starting to feel kinda warm!" while looming over them is the shadow of a kid with a magnifying glass.
- FoxTrot: One strip has Jason seemingly roasting ants with a magnifying glass and them eating them to gross Paige out. It turns out they were really just raisins.
- Antz. Used for an Independence Day spoof when a mysterious round object floats overhead ("It's beautiful!"), then a deathray-like beam shoots down causing the insects to burst into flames. Turns out the anthill is located in a public park where a kid is using a magnifying glass.
- In Ice Age 4: Continental Drift, Sid's little brother Marshall uses a piece of clear ice in this manner to burn an ant hill. We then pull back to see Sid's Granny doing the same thing to Marshall's head.
- In Toy Story, Sid burns Woody's forehead with a magnifying glass while "interrogating" him. It serves as a Chekhov's Gun, as it gives Woody the idea of using Buzz's helmet to light the rocket that takes them back to Andy.
- Alvin and the Chipmunks: Chipwrecked: To start a campfire, Simon demonstrates this by using his glasses as a magnifying glass to concentrate the energy from the sun. When Jeanette comments on it being impressive, Simon, distracted, accidentally redirects the beam to his foot!
Simon: HOT! HOT! HOT! (limps around the beach and jumps into the ocean, then sighs in relief) Ah...
- The Archimedes Death Ray variant of this trope is shown in Cabiria, starting with a scene where Archimedes experiments with mirrors in his lab, followed by a big action setpiece in which his mirrors set fire to the Roman fleet.
- Die Another Day's Kill Sat was essentially this, being one large mirror with a center focusing array to concentrate the light into a single, extremely hot beam.
- In Goodnight Mommy, Elias is shown burning the wall with a magnifying glass. Later, he uses it to torture the mother.
- Jules Verne was big on this.
- Dr. Clawbonnie used a lens made of ice to start a fire in Captain Hatteras.
- Cyrus Smith McGyvered a water-filled lens from two watch glasses in The Mysterious Island, as the castaways initially had no other means of starting the fire.
- In Codex Alera, a group of Knights Aeris windcrafters who can manipulate air for flight or as a lens, among other things under orders of main character Tavi work together to create a quarter-mile wide magnifying glass that focuses its light down to another windcrafter who redirects it as a solar-powered Death Ray.
- A pair of lenses from a telescope are used by the castaways to start a fire in The Coral Island.
- Discworld: In Small Gods, the Omnian fleet that attacks Ephebe is set ablaze by the rays from a massive mirror in a tower in the harbor. This is a direct reference to the ancient legend of Archimedes' "heat ray" in the siege of Syracuse.
- Mentioned in The Dresden Files in Changes, with rays of sunlight hot enough to melt metal.
- Piggy's glasses are used to start fires in Lord of the Flies. Only farsighted lenses can do that, and Piggy is one of the few boys who look past the moment.
- Alice, being a specialist in light magic, uses a spell to this effect in The Magicians. It's not very practical however—she was using it not long before sunset, and, after nothing the "lens" was a mile long, it still took her quite a long time just to burn through a door.
- In the Stephen King short story Mile 81, Pete Simmons uses this to set fire to the human eating monster car, effectively driving it off.
- In One Hundred Years of Solitude, gypsies put a pile of dry hay in the middle of the street and set it on fire with a gigantic magnifying glass. This makes José Arcadio Buendía think that it can be used as as a weapon of war.
- Used for a Bait-and-Switch in the drabble Research Project 12B by Richard Cassidy in which an apparent Mad Scientist Tested on Humans plot turns out to be a sadistic kid with a magnifying glass frying ants.
- Septimus Heap: Jenna used a magnifying glass she had stolen earlier to reflect the light onto and burn Simon's face. While being on a flying dragon.
- In the short story "A Slight Case of Sunstroke" by Arthur C. Clarke a soccer crazy Central American country loses to a hated rival which bribed the referee. They get revenge when the home crowd fans suddenly focus their metal-backed programmes on the referee, who is incinerated from the reflected sunlight.
- Star Wars Legends: Occurs in Wedge's Gamble. As part of a lunatic plan to take down the city-planet Coruscant's orbital shields, thus rendering it vulnerable to invasion, the Rogues require a massive thunderstorm (to take out the power grid). To get one, they settle on vaporizing all the water in a reservoir by redirecting and refocusing an orbital satellite. Used as intended, the satellite focuses sunlight on portions of Imperial City to make the temperature more livable. Used as unintended, it vaporizes the target reservoir and all in a matter of seconds.
- Using a magnifying glass to kill ants is listed as one of the misdeeds of Bruno the Spoiled Brat in The Witches.
- Most wilderness-survival shows, like Dual Survival or Survivorman, will demonstrate this method of fire-starting at least once.
- 3rd Rock from the Sun:
Dick: This afternoon I tried to borrow Mary's magnifying glass. You know, to burn some ants.
Sally: Of course, go on.
Dick: So anyway, she's like, "No, you'll break it!" And I'm all, "I will not!" And she's like, "It's mine, you can't have it!" So we had this huge fight. Finally, she let me borrow it... when she wasn't looking.
Sally: Let me guess, you broke it.
Dick: Yes! A particularly large queen burst into flames and I got scared and dropped it on the sidewalk.
- In 1000 Ways to Die, a jerk builds a giant version of one and uses it to destroy objects for his own amusement and he also tricks people into sticking their hands into the beam. He meets his end when he tries to cook a can of beans with it. The can explodes in his face, causing him to thrash around until he falls in the path of the beam, which quickly burns through his head.
- Lil' Bat tries to fry some ants this way in a cartoon segment of The Aquabats! Super Show!. The ants retaliate by eating him.
- Batman (1966): Catwoman once put Batman and Robin in a Death Trap that worked this way.
- In the last scene of the two part season 8 CSI: NY opener, the perp, a serial arsonist/killer does a version of this with his glasses and a book he was reading.
- Doctor Who:
- An episode of The Little Rascals involved Porky and Buckwheat having a bunch of firecrackers. Spanky and Alfalfa "confiscated" them by posing as a G-Man. Spanky tried to set off the firecrackers with a magnifying glass, but the school bell rang. Alfalfa took the firecrackers and stuck them in his back pocket - and Porky picked up the magnifying glass. During class, Alfalfa is called on to recite "The Charge of the Light Brigade", and this is when Porky uses the magnifying glass to set off the firecrackers.
- As noted above, MythBusters tested the Archimedes Death Ray three times (2004, 2006, and 2010) and all three times busted the myth, finding it impossible to focus light from shore mirrors well enough to set fire to a wooden ship. (Aside from the giant-lens-as-Death Ray myth, the show also tested whether it's possible to light fires with lenses made out of shaped ice or the polished bottoms of soda cans.)
Jamie: Our death ray doesn't seem to be working right. I'm standing right in it, and I'm not dead yet.
- In the Red Dwarf episode "Demons and Angels" when Lister denies that Evil!Lister is part of him, Evil!Kryten says "He's the little boy who, on a hot summer's day, held a magnifying glass to his best friend's neck and watched him burn."
- In Salute Your Shorts, Sponge and Donkeylips have to perform a task of starting a fire without using matches. After a while of rubbing sticks together, nothing appears to be working. Z.Z. then stops by, revealing she has a solution. Since matches couldn't be used, she takes off Sponge's glasses and uses them to start the fire.
- In an episode of the Shazam live-action TV series, Captain Marvel creates a lens out of sand by rubbing the sand very fast, in order to focus the sun on something.
- In the Brad Paisley song "Anything Like Me", the narrator imagines what his son will be like in the future, and says what said son will do if he's anything like his father. Among the activities listed is trying to melt a Tonka truck with a magnifying glass.
- The video for Soundgarden's "Black Hole Sun" features a couple of little boys frying bugs this way, only to have the tables turned on them.
- In Mage: The Ascension, one of the marauders (insane chaos mages) was rumoured to use a magnifying glass from a cereal box as a magic tool for his energy attacks.
- One Dungeons & Dragons supplement of amusing traps included a breastplate with a massive gem in the center that radiated magic. It did nothing while in the dungeon, but upon being struck by sunlight, it immediately focused an intense beam of concentrated light into the chest of the wearer, causing massive amounts of damage.
- The Dungeons & Dragons 3E adventure "The Eye of the Sun" centers around a magical artifact that acts as one of these. It's used by a cult of lizardfolk to burn a village down.
- The Mutants & Masterminds adventure "High Noon", part of the Lame Mage Evil Genius adventures, Dr. Null post-humously launches a doomsday device that deploys a cloud of small nanotechnology crystals that float around and focus beams of indiscriminate destruction from the sun's rays to destroy major cities.
- Warhammer has two war engines based on the focusing of solar magic with lenses and crystals. The Empire has the Luminark of Hysh, which uses an array of eight giant lenses to focus a mote of light magic into the ravenously destructive Solheim's Bolt of Illumination spell. The Lizardmen, meanwhile, have the Solar Engine - a giant faceted crystal held in a retaining harness that produces a similar burning death ray effect.
- Invoked in Shadow of the Comet for a Solve the Soup Cans puzzle. Basically, the hero is stuck in a lighthouse, and cultists are bashing at the door. Here, he finds a pair of wings and a candle. Using the magnifying glass in the inventory, he melts the candle to add wax to the wings. Guess what you do with the wings.
- In the text adventure Dragonsworld, Amsel signals an airship by using his magnifying glass to ignite a pile of leaves.
- In Crossfire, "magnifying glass" is a somewhat useful (increases Dexterity when held) Joke Item — a weapon with minimum damage and ant slaying property. Works even underground.
- In RTS Army Men games, this appears as a super weapon in some games. Due to the fact that all units are either little plastic men or (rarely) bugs, it works fairly well.
- In the Rise of Rome expansion to Age of Empires, there is a scenario that places you in control of the ancient Romans invading the Greek city of Syracuse. Surrounding the city's seacoast are several towers that shoot beams of light that set your ships on fire, referring to Archimedes and his heat ray.
- Appears as one of Penny's microgames in WarioWare: Smooth Moves. (BURN!)
- In 'The Incredible Machine'' magnifying glasses are used to set things on fire. With a flashlight.
- The lens from a broken telescope provides one of several ways for Mina to start fires in Return to Mysterious Island.
- In Gruntz, any Gruntz using the magnifying glass spy kit Toolz will use this as their attack.
- The Magnifying Grass from Plants vs. Zombies 2. It uses your sun to fire very powerful shots of light, and its Plant Food upgrade causes it to fire a concentrated beam that deals heavy damage over time and burns up zombies it kills.
- The level 11 quest in Kingdom of Loathing has you assembling the Staff of Ed and bringing it to a small pyramid in the desert with a scale model of the Seaside Town in it, under the impression that it will be a Sundial Waypoint and show you where the Holy MacGuffin is buried. What actually happens, though, is that the focused sunbeam sets the model on fire, revealing a trapdoor — the MacGuffin is inside the pyramid. The "Actually Ed the Undying" challenge path reveals that it's made of matchheads.
- One level in Age of Empires has Archimedes design mirror towers that are represented in-game as shooting lasers.
- In Girl Genius the heliolux airfleet, part of the Wulfenbach Empire's forces, has weaponized the interaction of magnifying lenses and sunlight on a large scale and uses their lenses to set people and towns on fire and "melt people into little puddles." The Jägers prevent them from participating in the assault on Mechanicsburg.
- In Adventures of the Gummi Bears, one of the ancient inventions built by their ancestors was a signal machine called the Gummiscope, which was also capable of generating a devastating beam that could burn practically anything. While the Gummis tried to use it to contact the Great Gummis overseas, Igthorn intended to use it to conqueror Dunwyn. Knowing that the scope was too powerful for anyone to be in control of, the Gummis destroy it by tearing out its supports with a flood.
- In an Adventure Time Ad Bumper, Ice King is trying to burn a giant ant. He then aims the magnifying glass at Finn, yelling, "You want some of this?"
- In Futurama episode "Crimes of the Hot", Prof. Wernstrom's plan to stop global warming is a giant mirror that reflects excess light away from the Earth. Then a small piece of space debris knocks it askew, and a beam of concentrated light slices through the city.
- An episode of Goof Troop ended with Max wearing glasses. The sun comes out and he practically weaponizes them.
- The Grim Adventures of Billy & Mandy pilot has Mandy melting Billy's toys with a magnifying glass.
- An episode of Inspector Gadget featured a computer-controlled space station with a giant magnifying lens which was used as a weapon until the Hal-like computer which was in control decided to destroy the lens to prevent it from being used for evil.
- The title character of Johnny Bravo does this in one episode, however, his real goal was to use the light from the ants to burn a hole in the sun.
- Ned's Newt: "I really shouldn't be wearing my magnifying-glass-hat now, should I?"
- The New Adventures of Superman: In "Seeds of Disaster", Supes uses the lens from an observatory telescope to focus the sun's rays to incinerate the alien seed pods.
- In one Oggy and the Cockroaches episode, the roaches attempt to toast Oggy with one, except that in lieu of a magnifying glass they use a bunch of solar panels (which Oggy installed) as a mirror.
- In The Perils of Penelope Pitstop episode "Hair-Raising Harness Race", while Penelope is trapped in a shed filled with explosives, the Hooded Claw has the Ant Hill Mob bound with a rope and hanging from a tree limb. A magnifying glass is set so that the sun's rays will burn the rope and send the mob plummeting into a deep chasm.
- In a Robot Chicken sketch a boy has his magnifying glass out to burn ants and laughs. God then hits him with a lightning bolt and laughs.
- The Simpsons:
- "Marge vs. the Monorail": After it all, we hear a voiceover from Marge.
And that was the only folly the people of Springfield ever embarked upon. Except for the Popsicle stick skyscraper. And the 50-foot magnifying glass. [the sun focused through the magnifying glass sets the Popsicle stick skyscraper on fire] And that escalator to nowhere.
- Bart burning a toy soldier◊
- Subverted in "Das Bus", when the children are stranded on an island. Nelson takes Milhouse's glasses to use for starting a campfire, suggesting this trope. He raises them up to the sun for a brief moment, before bashing a piece of flint against them. To Nelson's credit, it works.
- "Marge vs. the Monorail": After it all, we hear a voiceover from Marge.
- In The Smurfs episode "The Smurf Fire Brigade", Papa Smurf accidentally leaves his magnifying glass on the table outside before going into his house to take a nap. The magnifying glass focuses the sun's rays to start burning a spot onto the table until eventually the whole top of the table catches on fire. Lazy smells smoke and realizes he's in a dangerous spot, so he crawls out and yells fire, catching the attention of Papa Smurf and all the other Smurfs. Quickly a Smurf brings a bucket of water to the table to put out the fire, making all the Smurfs cheer.
- Star Wars Resistance: In "Dangerous Business", Kaz, trapped in a cargo crate that is about to be dropped into the ocean, uses a lens to focus the beam of a welding torch to make it powerful enough to cut through the door.
- The Tick had an inverted version of this, with evil giant ants that planned to deliver Karmic Deaths to all of humanity via one gigantic magnifying glass.
- One of the ideas of the "Strategic Defense Initiative" program was to combine orbital relay mirrors and directed-energy weapons into a Kill Sat effect similar to Archimedes' legendary mirrors, but much bigger.
- During the late 1770s, Antoine Lavoisiernote used a large glass lens (filled with alcohol for better refraction) to melt iron and attempt to melt platinum at short range. With some bit of improvement, The Napoleonic Wars might have been fought with laser-like solar guns - if some revolutionaries hadn't executed Lavoisier under the charge of treason.
- This is roughly how Concentrated Solar Power systems work: use mirrors to focus a lot of sunlight into a small area, use the resulting heat/high temperatures to generate electricity.
- One of Those Wacky Nazis' insane wunderwaffen projects was a contrivance known as the Sonnengehwer ("Sun Gun"), a gigantic orbital reflector array made of metallic sodium that would be used to incinerate enemy cities. Obviously, it never got off the ground.
- In 2013, a London building's curved exterior backfired when it turned out that sunlight reflected off the curved side could concentrate with enough heat to warp the metal of cars parked on the street.