[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/manhattanproject_2752.jpg]]
[[caption-width-right:350:Apocalypse 1986? A boy and his homemade atomic bomb. Built for the science fair. Seriously.]]

A 1986 thriller with liberal dashes of BlackComedy and GallowsHumor plus just a touch of [[MohsScaleOfScienceFictionHardness hard science fiction]]. Belongs to the same genre as ''WarGames'', as both films feature bright high school kids who almost single-handedly cause an international nuclear crisis. Although less high-spirited and possibly more {{Anvilicious}} than ''WarGames'', ''TheManhattanProject'' is still good fun.

Paul Stephens (Christopher Collett) is a TeenGenius and HighSchoolHustler from Ithaca, New York (best known as being the home of [[IvyLeague Cornell University]]). His divorced mother (Jill Eikenberry) starts dating nuclear scientist Dr. John Mathewson (John Lithgow), who runs the lab at "Medatomics", ostensibly doing research in nuclear medicine. The Medatomics lab, however, is just a cover story for Mathewson's real work, which is refining plutonium to previously unheard-of purities for use in nuclear weapons.

Paul decides to steal plutonium from [[TheGovernment the lab]] and use it to build an atomic bomb, partly to Make A Point, but mostly Because He Can. Paul thinks, correctly, that he has the most epic Science Fair project ever, and enters it in a Science Fair in NewYorkCity. When Dr. Mathewson and the U.S. Army figure out what Paul is up to, they are not impressed.

Features Creator/JohnLithgow playing a good guy during his "serious" period, and a young [[SexAndTheCity Cynthia Nixon]] as the hero's girlfriend Jenny.
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Tropes:

* BlatantLies: Dr. Mathewson's claim that the "green stuff" is actually just Americium-241. Paul figures out pretty quickly that it's actually plutonium, and that "Medatomics" is not really doing research in nuclear medicine.
* BrainlessBeauty[=/=]DecoyDamsel: the act Jenny puts on as she distracts the security guards with a self-inflicted flat tire while he pulls off his plutonium theft caper. Throughout the rest of the movie, however, she's actually quite sharp.
* TheCaper: The plutonium theft is played thus.
* CaliforniaDoubling: Averted. The film is set in Ithaca, New York, which is in the middle of UsefulNotes/NewYorkState about halfway between NewYorkCity and Buffalo. While not filmed in Ithaca itself, it was still filmed largely in Upstate New York.
* CasualDangerDialog: Dr. Mathewson when the bomb [[spoiler: suddenly begins counting down to detonation]].
-->'''Dr. Mathewson''': Gentleman, we've got a little...wrinkle here.
* ChildProdigy: A teenage boy is smart enough to break into a top secret nuclear production facility, steal plutonium and build an atomic bomb.
* [[ChekhovsGun Chekhov's]] [[FrickinLaserBeams Frickin' Laser Beam]]: The Medatomics lab uses one to purify plutonium. Dr. Mathewson uses it to impress Paul by having it cut through a steel plate. Later, Paul uses it to cut a small hole in the wall to help him smuggle out the plutonium.
* CouldntFindALighter: John Lithgow lights a cigar with a laser that is strong enough to cut through steel and concrete.
* DawsonCasting: Averted here. Most of the high school students we see are old enough to drive and are taking physics, which implies that they are probably at least 16 years old. Pretty much every actor in the film who plays a high school student (including Christopher Collett and Cynthia Nixon) was under 20 years old at the time of filming.
* DeadpanSnarker: Both Paul and Dr. Mathewson have their moments.
* DisappearedDad: Paul's dad left his family and is now in Saudi Arabia. Paul is understandably somewhat bitter: "I guess he didn't like being married anymore. Actually he's a brilliant architect; he's just kind of a shit in his personal life."
* ExactTimeToFailure: Double subverted near the end of the movie - the homemade atomic bomb is accidentally armed and its display is turned on. It starts counting at 999 hours, so at first no one's worried about disarming it in time... until Paul realizes his timing mechanism isn't perfect and will speed up the clock as it goes on. The double subversion comes into play when he and Dr. Mathewson eventually remember that the degradation will follow a perfect exponential curve, so they can calculate exactly how long it will take the timer to reach zero. (Which is much, much sooner than they'd like.)
* GallowsHumor: A lot of it near the end while they try to disarm the bomb.
** "I wouldn't bump it around like that if I were you. It might decide to fire just for spite."
** "Are you telling me I'm going to die because some asshole didn't bring a pair of pliers?"
** "Anyone want to make a bet?"
* TheGovernment: Most notably the U.S. Army, the FBI, and the Department of Energy.
* HardWorkMontage: Near the middle of the film, where slices of everyday life for Paul are intercut with him studying book after book on nuclear physics and building the bomb over a period of about four weeks.
* HighSchoolHustler: Paul
* [[ICantBelieveImSayingThis I Can't Believe I'm Saying This]]: Paul to Jenny in the hotel hosting the science fair.
-->'''Paul''': I never thought I'd say this to anybody, but I've got to go get the atomic bomb out of the car.
* InstantDeathBullet: A sniper claims he can do this to both Paul and Dr. Mathewson if need be.
* InsufferableGenius: Paul could very well be the posterchild for this.
* IntrepidReporter: Jenny is a would-be one. She's writing a story on Paul's building of the atomic bomb and wants to send it to ''Rolling Stone'' for publication.
* ItWasHereISwear: The atomic bomb in the trunk of the car.
* IvyLeague: The film is set in Ithaca, New York, the home of Cornell University. Although the school is never shown in the film, Paul mentions that his father used to be a professor of architecture there.
* JerkAss: Paul, maybe.
* JustEatGilligan: Since the military knew that Paul had the bomb with him at the science fair, they should've been able to locate it just by sending agents out around the hotel armed with Geiger counters (especially since Paul didn't realize how pure the plutonium was, it would've been firing off a LOT of free particles).
* KarmaHoudini: Paul, he attempts to commit nuclear terrorism and gets away with it scot free. At worst, he may be grounded by his mother.
* KeepingSecretsSucks: By the end of the film, [[spoiler: Dr. Mathewson has come around to this point of view, and plans to publish his work on purifying plutonium.]]
* NoNameGiven / WhoIsThisGuyAgain: Actor [[SixFeetUnder Richard Jenkins]] receives billing only as "Radiation Controls Officer - Medatomic Labs". The character actually does have a name: Miles Wilson. Each part of his name, however, is only said once, and even then said in different parts of the movie. He is never actually referred to in the film as "the Radiation Controls Officer".
* NotSoDifferent: Dr. Mathewson's actions toward Paul implies that the boy reminds him a lot of himself when he was younger.
* OedipusComplex: There are a few jokes about this between Paul and his mother. Jenny even suggests this as Paul's motivation to be distrustful of Mathewson.
* ProductPlacement: Alberto's [=VO5=] shampoo, which looks suspiciously like the liquid in which the highly purified plutonium is kept. Also, to a lesser extent, Duracell batteries.
** And the remote-controlled car used to smuggle the plutonium out of the building, which is clearly labeled as a model of a Subaru Brat.
* PunchClockVillain: The FBI Agent who says to Paul, "Sorry about before, kid. Nothing personal. Just doing my job." This is the same guy who was moments from shooting him in the head.
* ReluctantMadScientist: Possibly Dr. Mathewson. He enjoys the challenge of purifying plutonium for its own sake, and does not seem to have an issue with his work being used to develop increasingly powerful nuclear weapons. Later on, Lt. Col. Conroy forces him to face the cold moral and ethical realities and responsibilities of what he does for a living.
* RefugeInAudacity: Paul plans to unveil a fully working home-made 70 kiloton nuclear bomb at a New York science fair and win first prize. He doesn't expect any interference from the authorities whatsoever. Even when he's caught by government agents, he acts like it's a social call.
-->'''Paul''': Hi Dr. Mathewson!
-->'''Mathewson''': Paul, what the hell are you doing?
-->'''Paul''': Well I thought we might start with some kissing and then move into the fancy stuff.
** Even after Paul is caught and is discussing his options with Mathewson, he says he will give the bomb to the government only after he wins the science fair with it, and he expects them to agree.
* ScienceFair: Paul says he's going to submit a project about raising a generation of hamsters in the dark to see if it improves their hearing. It's just a cover story for the real project--his atomic bomb. It's at the "45th National Science Fair" where Dr. Mathewson and TheGovernment catch up to him.
* ShoutOut: A few of them to the real Manhattan Project, specifically the Trinity nuclear test:
** At one point in the film, a timer reads 7:16:45. The Trinity test occurred on July 16, 1945.
** Following the Trinity test, Manhattan Project scientist Kenneth Bainbridge said to colleague Robert Oppenheimer, "Now we are all sons of bitches." This quote is alluded to twice late in the film.
-->'''Lt. Col. Conroy''': (to Dr. Mathewson) "You are what you are, doctor: a son of a bitch just like the rest of us. Now for God's sake take some responsibility and do what has to be done!"
-->'''Dr. Mathewson''': (to Lt. Col. Conroy and his team) "Hold it, gentlemen. Fellow sons of bitches, we're all what we are, right? So here's ''my'' responsible act..."
** When Lt. Col. Conroy is struggling to unscrew the cap to get the core out, Dr. Mathewson remarks, "That's funny. The same thing happened at the Trinity test 40 years ago. The core got stuck halfway in while they were trying to insert it."
** Right before settling a WireDilemma, Mathewson asks, "Anyone want to make a bet?" In a real-life incident of GallowsHumor at the Trinity test, a number of scientists wagered on exactly how powerful the explosion would be. Wagers ranged from a dud, to 18 kilotons (the winning wager by physicist I. I. Rabi), to destruction of the entire state of New Mexico, to ignition of the atmosphere and the incineration of the entire surface of the Earth.
** There are also Shout Outs to two other movies dealing with the threat of nuclear weapons:
*** ''Film/TheDayTheEarthStoodStill1951'' (the 1951 original) is playing on the TV while Paul and Jenny are planning the plutonium theft.
*** When Paul figures out that Dr. Mathewson helps build nuclear weapons, he starts referring to the scientist as "Film/DrStrangelove" behind his back.
* SpiritualSuccessor: Arguably to WarGames.
* TailorMadePrison: Invoked by Mathewson as the potential consequences of Paul's pet project.
-->'''Mathewson''': They don't care how old you are, how cute you are. They're gorillas; they can ''hurt'' you. Don't you get it? You try to tough it out with them, they'll lock you in a room somewhere and ''throw away the room.''
* TeachersPet: Roland, which is presumably why Paul makes him the ButtMonkey of the nitrogen triiodide prank.
* TeenGenius: Definitely Paul. Maybe Roland. Likely the four geeks at the science fair, too.
* TimeBomb: Paul's atomic bomb has a digital timer.
* TooCleverByHalf: Both Paul and Mathewson are guilty of this. Paul for building a nuke without thinking too deeply about the consequences of his project, and Mathewson for being too busy being proud of his plutonium production process to think of the wider ramifications of his work.
* TruthSerum: The military administers some to Paul to "help him remember" after the ItWasHereISwear incident.
* VillainProtagonist: Paul is a kid who thinks pranking others with explosives and being a nuclear terrorist to get his way is the way he should do things.
* WireDilemma: Subverted; when disarming the bomb, Paul's design necessitates severing all six wires simultaneously, since the other five could set off their triggering charges prematurely if they tried to do it one at a time.
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