Tony Stark designed and developed an arc reactor in a cave. Did he already have a design of an arc reactor in mind?

  • If yes then why didn't he invent it before he was kidnapped?
  • If no then how come he could design and produce it in such a short time span?
  • 1
    You know that saying, necessity is the mother of invention? Apply that here. Inventor types and creative geniuses can have spurts of hyper insightful and productive runs in short periods of time. He was perfectly happy making weapons selling to the highest bidder until the need for survival kicked in. And yes..at the end of the day, it's still just a comic book movie. But...Look up E-cat, E-cat X, Andrea Rossi, and LENR and you'll actually come across some possibly plausible (hopefully) impending tech that could resemble Stark's Arc Reactor in the coming years.
    – user59280
    Commented Jan 14, 2016 at 3:35
  • Because he is brilliant??
    – HBhatia
    Commented Jan 14, 2016 at 4:30
  • This isn't long enough for a full answer, and I don't have sources, but I think the answers missed something. In the scene where Tony is being tortured, it shows quick flashes of things that he is thinking of while they are dunking his head in water. One of those is the arc reactor. I think Tony figured out that he could do it while he was being tortured, and agreed to "make weapons for them" so he could use the new idea to get himself out of there.
    – Cody
    Commented Aug 2, 2017 at 18:30

3 Answers 3


Short answer:

Not likely. He managed to recreate a technology without blueprints, schematics, or a clean room, made completely of spare parts and miniaturized a technology to one ten thousandths, of it actual size AND make it produce the energy output of a small nuclear reactor. Oh yes, did I mention he did it in under a week? See: Phlebotinum

Longer Answer

  • You cannot take this stuff seriously. This is one of those comic things where a willing suspension of belief is an absolute requirement.

  • It is completely impossible for him to have created his personal arc reactor under those conditions. The idea of Tony Stark, as a character, is that he is genius personified. In the Marvel Universe, he is one of the most inventive, creative and adaptive humans alive.

  • The arc reactor had existed for at least 30 years, as Obidiah Stane reminds Tony, as a publicity stunt, nothing more. It was not energy effective, implying it cost as much in energy to run it as it produced.

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  • You must also remember, this story is an adaptation of the original Iron Man story where he did not create the Arc Reactor, he just created the basic Iron Man Armor. That armor ran on batteries. In its heyday, it would have been considered a fantastic device (being honest, even today, the first comic version of the Iron Man prototype would be a game changer.)

enter image description here

The very first Iron Man armor. Grey, dull, and ran on battery power. It's initial power? It deflected bullets.

  • And such as it is when something is adapted for movies, the adaptation always tries to exceed the original. Given its immense size, power requirements and up to this point inability to be a break-even proposition on energy, it would have been nothing more than a pretty science project in Stark's book.

  • So in this one, Tony will, somehow, create an energy source, faster, stronger, better, cleaner and ten thousand times smaller, than anything ever seen before from the stone knives and bearskins lying around a terrorists camp in some Third World Nation (filled with his weapons) and in addition to the miracle of the Iron Man Armor, he will also create the world's first pocket-sized tokamak fusion reactor.

enter image description here

This is a real tokomak fusion reactor. It is an immense thing, far larger than even the arc reactor (show above)

  • You are not supposed to take it seriously and wonder why he never created this before, you are supposed to be in awe of him creating it under such adverse conditions, while shrapnel is approaching his heart, while terrorists are terrorizing him, and he doesn't even have access to a clean room.
  • 7
    I'd upvote, but I'd have to dock points for not using the phrase "In a CAVE with a BOX OF SCRAPS"... Commented Oct 25, 2013 at 5:43
  • It took me a minute to remember why that phrase was relevant. Stane was screaming that, wasn't he? I will find the relevant quotation and include it somewhere. Where is my Iron Man DVD? Damn kids... Commented Oct 25, 2013 at 20:43
  • Here's the link Commented Oct 26, 2013 at 11:33

The underlying arc reactor technology existed before the events of the film, you can see the large-scale version within the Stark building of the first film and it plays a part in the final battle. Stane describes it as a 'sop to the hippies' or something along those lines, with an implication that it is too expensive to be of practical use.

Stark's genius (in this case) was in somehow miniaturising the technology, which seems to have made it more practical. Since his company had already made a building-sized arc reactor, and he is the driving intellectual force behind his company, it seems very likely that he was already aware of the underlying principles of the thing and that he made some kind of creative leap while in the cave with a box of scraps that allowed him to improve the process.

  • Nice, but if he was already aware of the principles then why not a single try to create it is shown before he is made captive?
    – user18957
    Commented Oct 24, 2013 at 12:27
  • 12
    Tony Stark is... not the most focused of individuals. I think it comes down to him not having any motivation to work on the problem until the events of the first film.
    – evilsoup
    Commented Oct 24, 2013 at 12:30
  • 6
    @user18957 "but if he was already aware of the principles then why not a single try to create it is shown before he is made captive?" I'm aware of the principles and all the know-how to create lots of things that I just don't have the time or need to. Stark Industries was primarily a weapons manufacturer, a clean power supply was hardly a priority for him. Before his imprisonment, he had no specific need to create a miniaturized reactor.
    – phantom42
    Commented Oct 24, 2013 at 12:49

@user18957: Tony's genius was to minituarise the arc reactor running at Stark Industries. The 2nd installment of series shows that the original (and successful) arc reactor was prepared by his dad, Howard stark, in collaboration with the Russian physicist Anton. hope this provides a satisfactory answer to your query. :)

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