Creative decompression

[shawnhcorey]

Originally Posted by Dangerious P. Cats

It's common in fiction to use decompression to suck things out airlocks into space...

I'm sorry but vacuums don't suck, black holes do. The correct terminology is: It's common in fiction to use decompression to blow things out airlocks into space...

[fictionfan]

I think that if you have artificial gravity you are better off using that.

Cush, distract.

[RyanW]

Originally Posted by Crakkerjakk

Same. This also explains why in the future everyone is always traipsing around in spandex bodysuits. I treat the suits as basically long underwear everyone is always wearing, with most people wearing something light with lots of pockets on top of it for modesty.

Wearing something over the space suit does make it a little harder to notice tears. In a counterpressure suit instead of a gas pressure suit, a small tear isn't as disastrous for a brief exposure to vacuum, however.

Originally Posted by shawnhcorey

I'm sorry but vacuums don't suck, black holes do.

Black holes don't exactly suck. They have gravity, but no more than a star of similar mass at the same distance. It's just that since it is so small, that distance can be very small. Anything near the "surface" will need exceptionally high speed to escape and experience large tidal forces.

[Crakkerjakk]

Originally Posted by RyanW

Wearing something over the space suit does make it a little harder to notice tears. In a counterpressure suit instead of a gas pressure suit, a small tear isn't as disastrous for a brief exposure to vacuum, however.

Hell, a tear probably won't even leak, just gives you a blood blister on that spot. You're only pressurizing the helmet with air. Besides, in all the sci-fi I run you have smart fibers that report tears with diagnostics. We almost have stuff like that now for next-gen military uniforms, I feel it's right at home in pretty much any sci-fi.

[Snoman314]

Originally Posted by Dangerious P. Cats

It's common in fiction to use decompression to suck things out airlocks into space, obviously in a less-realistic settings this would be fine to replicate but I'm wondeirng if it could be done in a more realistic setting.

Decompression could be categorised in three ways: Gradual, rapid and explosive.
Gradual decompression is going to set off pressure alarms etc, and unprotected personnel are going to start getting hypoxia etc.
Rapid decompression effects that are likely to be significant include: decompression fog, bends/hypoxia/ebullism/loss of conciousness etc for unprotected personnel, maybe some wind for a short time.
Explosive decompression is called that because the escaping air is like a bomb going off. A little like being hit by a shockwave, loose objects will get pushed around, but only for a fraction of a second, 0.5 seconds at most. This may be enough to blow you out if you're right next to the airlock door or whatever, but the force drops off very quickly over both time and distance. If there are any constrictions in the airflow, there my be other points that experience explosive force, but the more chokepoints there are, the more likely the decompression will instead simply be rapid, not explosive. The key point being, that its all over in a moment, not like the constant blowing gale you see in the movies.

[Phoenix_Dragon]

Decompression rates really depend on the size of the hole and the volume being vacated. I found a formula here: http://www.geoffreylandis.com/vacuum.html which looks to give a good, simple guideline for such things.

For an example, if the compartment is about 1000 cubic meters of open space, and you open a door into space, you'll drop 90% of your pressure in just over 8 seconds. That's about a ton of air going through that door, or a bit over 100 kilos per second. Anyone standing near the door probably gets pushed around a fair bit, though since they'd only be blocking a small part of that, I wouldn't expect them to get thrown out the airlock most likely. Someone standing -in- the doorway might be in the way of as much as half that air in total, which would be dangerous, but they may be able to hold on if they're lucky. Someone at the other end of the room would probably barely feel the wind's push (So yay, he just has to deal with all the other fun effects of explosive decompression).

(Assuming the formulas are correct, of course)

[DemiBenson]

Originally Posted by shawnhcorey

Sliding doors are harder to seal. Also, they use swinging hatches on submarines to seal off a compartment if there's flooding and those hatches have to withstand more than one atmosphere.

Submarines have special circumstances:

• access is not via airlock (they only open doors on the surface, so no pressure differential)
• very limited space and non-mechanized doors (neither of which are typical of generic sci-fi spaceships)
• no regularly-traversed internal airlocks, only compartmentalization for damage control purposes
• flooded compartments are always at higher pressure than non-flooded
• an emergency doctrine that amounts to "seal off damaged compartments from the core, and rescues will be at zero pressure differential"