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In (real) Explosive Decompression, if a pressure vessel's structure were to be compromised, all of the gas held inside would rush out until a state of equilibrium has been achieved (if this pressure vessel were in space, this would effectively mean all the gas would be blown out). Keep in mind that there's only 14psi between 1 atmosphere and vacuum. It would take a very large hole to produce actual explosive decompression. Consider an automobile tire at twice that pressure differential; if it gets a hole in it, the air leaks out. It does not explosively decompress unless the structure of the tire fails completely (e.g. if it is overheated).

Not so in TV science fiction. If explosive decompression were to occur, a constant wind will appear and attempt to blow the entire contents out into space, and will only cease once the hole has been closed. This may even occur for several minutes, even if in real life the hole is big enough to allow all air to escape in a matter of seconds. And of course, the wind will always be just strong enough to make people's clothes flutter, but just weak enough not to actually blow them over -- unless they have the unfortunate chance of being the bad guy or a Red Shirt, that is.

However, sometimes this trope is justified. When a hole is created in a realistically sized space station (~1 mile diameter), it would take about 19 windy minutes to achieve equilibrium (with the remaining air and the windspeed both decreasing exponentially, of course) - at least if the builders failed to put in any airtight doors with which to seal the breached area.

The "remaining air" fact is also neglected in sci-fi. As the air leaks out, the air pressure inside decreases. The inside should become increasingly impossible for a human to operate in long before all the air is out.

Examples of Continuous Decompression include:


Anime and Manga

  • The Gundam franchise uses this a lot. Sometimes it's justified (an Island 3 space colony holds around 1,600 cubic kilometers of air), and sometimes it's less so (Mobile Suit Gundam The 08th MS Team has a room in a Magellan-class battleship decompressing for a ridiculous amount of time).
    • Usually, the really worrisome holes in colonies are caused by mobile suits' nuclear reactors exploding[1]; some later machines use an adhesive spray to seal up smaller holes, and in Mobile Suit Gundam F91 the bad guys have developed a weapon specifically to avoid causing a reactor detonation.

Film

  • Star Trek Nemesis, when the Enterprise's bridge is blown open.
  • Naturally, Galaxy Quest had to have this trope.
    • Strangely enough, it was ALMOST justified: the room was being decompressed as a form of torture. The wind actually died down as the pressure started dropping too low, although it was going too slowly to cause THAT much wind, and didn't kick up again until they broke the seal into the still-pressurized hallway.
    • There's also the part where the rock monster trashed a pack of the bad guys and ended it with busting clear through the wall of the ship; you see an external shot with a bunch of stuff flying off after them but no sign of that particular hallway afterward, so it's hard to tell if it's subverted or played straight.
  • Both Alien Resurrection and Goldfinger use a variant of this trope, where incredibly big people/aliens are blown out of incredibly small holes.
    • It may be actually possible to perform this, as this video of a crab being sucked entirely through a hole many times smaller than itself demonstrates. Also related, the Myth Busters squeezing a meat dummy into a diver helmet merely by removing its internal air pressure. Scary, scary stuff that may provide a basis for this in reality, though movies a frequently known to exaggerate those well beyond realism.
    • In the original novel for Goldfinger, James Bond deliberately caused it (while in the film is an accident), supposedly having been inspired by a real-life event.
  • During a Dream Sequence in Apollo 13, the door on the capsule opens during transit to the moon. The astronauts cling to the capsule against the wind for much longer than it would take to let all of the air out. (But then, it was a nightmare).
  • A pressure dome on Mars breaks in Total Recall and the resulting storm is enough to pick people up and fling them through the hole. Even Arnold Schwarzenegger has to cling to a railing as if he was inside a tornado. But then, somehow, he gets up and runs out a door just before it closes. (Remember that this is the movie where people's eyes bug out of their heads after exposure to Mars' very thin atmosphere -- an effect that can be reversed with no harm done).
    • But, then again, It was ALL a dream. Or Was It a Dream?
    • Actually, there was a sequence with at least three blast doors covering over the entire facade that had blown out, with the turbulence noticeably decreasing as each one slammed home. The people inside the dome weren't able to move until most of the doors had slammed into place, and Quaid was lucky enough to have been already close to the last one.
  • An inversion and aversion can be found in The Abyss. When an entire windshield of a minisub at the bottom of the ocean cracks as it uncontrollably descends into the abyss it implodes immediately. When there is a small crack in the hull of another minisub at its normal operating depth, it slowly fills with water, albeit higher than the level of the crack.
    • It continues filling to a higher level than the crack because it won't stop filling until the air left inside the sub is at the same pressure as the water -- i.e., a few hundred atmospheres.
      • But the air is already at the same pressure as the seawater outside--the drilling rig is under the same high pressure, hence the use of the "moon pool" for coming and going. It's why Lindsey and the soldiers took eight hours to equalize pressure before leaving the sub.
  • After Crow breaches the hull in the pre-movie segment of Mystery Science Theater 3000 The Movie, the entire room starts uncontrollably decompressing until Tom Servo is sucked into the hole - and is just wide enough to plug it up, as it so happens. Immediately after, Mike pulls him out and casually puts Crow's WWI helmet over the hole.
  • Snakes on a Plane: When Agent Flynn shoots out a window, the compression is powerful enough to destroy part of the wall, and lasts long enough to suck every single snake out of the plane.
  • The sci-fi B-Movie Missile to The Moon ends with the Lady Land society being destroyed this way.

Literature

  • Played quite realistically in the Robert A. Heinlein book Farmer in the Sky. During the trip to Ganymede, a bit of space junk penetrates the hull of the Mayflower in the dorm compartment where the protagonist and twenty other boys happen to be staying. The hole is explicitly only the size of his fist, and after the automatic failsafes seal off the compartment (locking the boys into the decompressing room), he's able to plug it with one of their foam-rubber pillows.
  • In Conspiracies, a gateway into another dimension opens up in a basement and starts sucking in everything around it, air included. The effects are portrayed realistically, right up to a character shackled near the gateway feeling his eardrums suffer as the air pressure drops, then recover when the windows break and new air is drawn into the cellar.

Live Action TV

  • Star Trek is a big offender of this, especially in the modern series.
    • But averted in an episode of Star Trek the Next Generation: when Geordi and Dr. Crusher depressurize a cargo bay to (a) put out a plasma fire and (b) get rid of some hazardous material, the wind lasted only a very short time. After that, the trick was repressurizing the bay before they passed out from anoxia.
      • Although Dr. Crusher gave horrible advice by telling Geordi to hold his breath. In reality, holding your breath in vacuum would rupture your lungs. The right advice is to hyperventilate in advance to superoxygenate your bloodstream, then exhale fully when decompression occurs.
    • Star Trek Deep Space Nine did something similar in "Covenant". Dukat opens an airlock to kill a Bajoran woman. While the decompression lasts far long that it should for a roughly 3 cubic meter room, it does cut off before the door finishes opening, leaving her to suffocate on the floor.
    • In Star Trek Enterprise, TNG's magic force field that lets ships go through but not air has not been invented, so when a bad guy takes his leave while Archer is still in the shuttle bay, he must deal with this. However, more realistically than most examples (including other Star Trek examples), the fact that there's less and less air and pressure in the open shuttle bay every second is very much a problem.
  • Averted in Battlestar Galactica Reimagined, where explosive decompression actually behaves like it should.
  • Not averted in Ron Moore's pilot movie Virtuality, though -- in fact, this is one of the worst examples of all. A character is caught inside a small airlock when the outer hatch opens, and is buffeted by a huge torrent of wind for a couple of minutes before the other characters can shut the door. Where was all the replacement air coming from???
  • Happens in the 1970s Doctor Who story The Mutants.
    • And in an earlier Who story The Moonbase, which also features the subtrope of characters struggling to seal the hole as the air rushes out. One fan actually did the calculations to see how long it should have actually taken for decompression to happen. The results were something on the order of a few seconds. The scene in the episode lasted much longer, obviously.
    • In the Doctor Who story Enlightenment, Turlough is locked in a small chamber when the protective force field is deactivated letting the air escape to space. It takes several minutes for the doctor to find Turlough, during which time it is still slowly evacuating though the hole is quite large and the room is quite small. Ironically it is also an example of Explosive Decompression, since when Turlough is rescued, he says "I would have exploded in the vacuum of space."
  • When a plane is ripped opened in the third season of Heroes, air is continually sucked out of the plane until it crashes about ten minutes later. (Probably due to the turbulence from the incredible windspeed outside the craft.)

Video Games

  • Opening an airlock in Dead Space will cause a few seconds of windy turbulence (That's not how airlocks work!) but later an entire deck has its atmosphere vented into space with a minimum of fuss.
    • While It can be understandable that internal doors to damaged sections might leak air, this also happens with doors designed to lead into space.The fact that Isaac and Kendra are hacking the doors and the damage to the ship might explain some things.
    • There are fragile windows in Dead Space 2 that when broken will suck enemies out into space and Isaac will be dragged along....before being crushed by a door closing.
  • The Halo series averts this, with the games depicting airlocks cycling realistically, and the books at least not mentioning a wind when decompression is involved.
  • The final challenge in Conkers Bad Fur Day features Conker in a life-or-death battle with a xenomorph-like alien on a spaceship (long story). Near the start of the fight, Conker has to blow the airlock, producing a constant state of decompression as air keeps rushing out. This decompression lasts the entire battle, no matter how long it takes (and even if you pull it off quickly, it's still more than a bit absurd), and has to use said decompression to throw the alien out. The ship's onboard computer helpfully reminds him of this fact.
  • Justified in in Portal 2. When Chell opens a portal on the moon, there is a continuous decompression effect until the portal is shut. Spaceships and the like may have a limited volume of air, but this portal has to equalize the pressure of an entire planetary atmosphere. Sucking away this much air takes lots of time.
  • Averted in Space Station 13, which has a relatively realistic atmospheric model (which, of course, is almost never used).

Webcomics

Western Animation

  • Futurama was probably parodying Star Trek when they did this.

Notes

  1. as seen in the first episodes of Mobile Suit Gundam and Gundam Unicorn, with Amuro slicing a Zaku in half and Marida blasting a Jegan with her funnels respectively
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