“It wouldn’t happen that way in real life.” One of the most annoying habits of people really into the “sci” of sci-fi is nitpicking scientific inaccuracies in movies. The truth is, some things just make movies better, even if they are wrong.
What would Star Wars be without the sounds of an epic battle in space where there should be no sound? But there are plenty of other examples where things are wrong and it would have been just as easy to get them right — the direction of space debris in the movie Gravity, for example. But what about the age-old trope of explosive decompression? Some movies show gross body parts flying everywhere. Others show distressed space travelers surviving in space for at least brief periods.
It turns out, dropping pressure from one atmosphere to near zero is not really good for you as you might expect. But it isn’t enough to just make you pop like some meat balloon. You are much more likely to die from a pulmonary embolism or simple suffocation. But you are a meat balloon if you experience a much greater change in pressure. How do we know? It isn’t theoretical. These things have happened in real life.
In 1966, NASA spacesuit technician Jim LeBlanc found out about the first problem the hard way. Wearing a Gemini space suit, he entered a vacuum chamber and had an accidental pressure hose disconnect. Within 10 seconds, the pressure in his suit went from 3.8 PSI to nearly zero.
LeBlanc reported he could feel saliva boiling off his tongue before he passed out. The fact that he could report this should tell you that it all ended well. Instead of the normal thirty minute repress sequence, engineers restored air to the chamber in 87 seconds, although he got emergency oxygen 25 seconds later. Outside of an earache, he was fine. He stayed conscious for 14 seconds.
Explosion
So does that mean exploding people are just a movie phenomena? Not quite. It just takes a bigger pressure differential. A drilling rig, the Byford Dolphin, had an accident in 1983. Five crew died and a sixth was seriously injured.
The platform was drilling in the Frigg gas field in the North Sea. Four divers were in two connected chambers at a pressure of 9 atmospheres. One of the chambers also connected to a diving bell. The bell used a clamp to isolate it from the chambers. However, the clamp was opened too early which caused the 9 atmosphere pressure rush to the 1 atmosphere bell.
The bell was blown away and the victims suffered a variety of effects ranging from their circulatory systems jamming up with suddenly insoluble fats to violent decompression that left internal body parts as far as 30 feet away.
Newer rigs have more safety systems and interlocks to prevent things like this from happening. Officially, the cause was human error, although there are those who believe it was faulty equipment to blame. After 26 years, the families of the victims did receive a settlement from the Norwegian government.
Space
So surviving a few minutes of vacuum like Dave Bowman did in 2001: A Space Oddessy is probably more realistic than Arnold Schwarzenegger exploding in Total Recall. However, it wouldn’t be pleasant. In the 1960s, the Air Force did decompress a group of chimpanzees with only one fatality — an older chimp with other health problems.
It is a rare space movie that gets everything right. Explosions look different than you’d expect, spaceships don’t constantly accelerate while their engines are running, There’s a host of other issues that affect most movies.
However, Gravity might be the hardest to swallow with a very old lieutenant in command of the Space Shuttle. It might not be science, but it is still hard to imagine you could turn 50, be in command of the shuttle, and still be only a lieutenant. Of course, seeing Sandra Bullock shimmy out of a space suit looking picture perfect is worth at least a giggle. Between the sweaty nature of being cooped up in one, and the reality of the built-in toilet system, real-life space suits are just gross.
But, hey! It is just a movie.
“The bell was blown away and the victims suffered a variety of effects ranging from their circulatory systems jamming up with suddenly insoluble fats to violent decompression that left internal body parts as far a 30 feet away.”
Big chambers then?
Ouuuch. Wikipedia has a gruesomly detailed description of the accident (which happened on deck, during decompression, so sufficient room to throw body parts all the way across the platform): https://en.wikipedia.org/wiki/Byford_Dolphin#Diving_bell_accident
Well if you truly want to make the death penalty a deterrent just broadcast executions in decompressing high pressure chambers. Yuck!
It would be more humane, since explosive decompression works faster than lethal injections, hanging, or electrocution. Your brains become porridge faster than the pain signals can travel up the spinal cord.
OMG. That Wikipedia entry was gruesome reading.
No, their body parts were launched outside the chamber at high speed.
So the chamber ruptured ?
“Hellevik, being exposed to the highest pressure gradient and in the process of moving to secure the inner door, was forced through the 60 centimetres (24 in) diameter opening…”
From:
https://en.wikipedia.org/wiki/Byford_Dolphin
“..including bisection of his thoracoabdominal cavity, which resulted in expulsion of all of the internal organs of his chest and abdomen..”
“..were projected some distance, one section being found 10 metres (30 ft) vertically above the exterior pressure door..”
O.o
So the issues weren’t so much from the pressure drop as being launched through a hole? Can’t say it’s an article I really want to read and keep my lunch down at the moment, but sounds like injuries may not have been ‘purely pressure related’ which involved exploding body parts.
Have read the article on the wikipedia (and yes, a really lamentably accident) and the only part I could find there for the effects of decompression were “large amounts of fat in large arteries and veins and in the cardiac chambers”, cause of which is suggested as “the rapid bubble formation in the blood (that) denatured the lipoprotein complexes, rendering the lipids insoluble”. So yeah, the causes of deaths was linked to secondary effects of decompression and of course, the ejection of 9 atmospheres through a small area. more akin to being near a explosion. None of those effects would be what one see in the media about explosive decompression in space.
It was a combination of extremely quick decompression and of being shot out of a large air cannon of a sort.
As I understand it was caused by an error in operation sequence of equipment that lacked a working safety interlock mechanism. That door should have not been possible to unlock before others were securely locked.
THAT is a disturbing sentence to read.
Oh, don’t use Gravity as an example. There was so much bad science in that movie you could make a movie about it. Including the debris scene. It was just wrong. I’m pretty sure there are articles out there about it.
I remember being completely confused in the theater about why she didn’t just bound back to the spacecraft when she reached the end of the tether that she was hanging on to. I just couldn’t figure out what was supposed to be going on.
I remember the whole theater having a muted sarcastic chuckle at the end where she got caught up in the seaweeds after landing. Talk about stretching the point.
I’ve heard from a real astronaut about that.. To start with it takes 48 hours to prepare a space walk. An emergency repair at the ISS was done with a 24-hour prep & suit up. To contain the pressure, the suits are /really/ hard to move in. After a space walk with any real work, you return bloodied with flesh wounds and nerve damage from using arms, hands, legs. You’d need a fairly strong physique to start with.
“After a space walk with any real work, you return bloodied with flesh wounds and nerve damage from using arms, hands, legs. You’d need a fairly strong physique to start with.”
After piloting or operating the operators potentially might not return and can return dead. Not just from suicide missions.
More reason I have always thought from my earliest memories of air and space operations… Why don’t we remote control and/or use robots to do that work?
Because it is slow, expensive and the robots capable of doing that kind of repair/maintenance reliably don’t exist? Also most of the hardware has been designed for humans to operate and maintain, not for robots – and making a robot that can make use of that is highly non-trivial. Look up the failed Robonaut project if you want to see why.
Doing this stuff by remote control is only slightly easier – the problem is not the “brains” of the operation but the poor dexterity and reliability of the robots along with the inevitable lag due to the radio link. If your life support is down the last thing you want is to have to first troubleshoot and fix a robot so that you can go out and repair whatever is required.
Human flexibility and dexterity together with the Mk 1 eyeball sensor package and Mk 1 brain controller is very difficult to surpass when you are this constrained.
“Because it is slow, expensive and the robots capable of doing that kind of repair/maintenance reliably don’t exist?”
I think they can exist… they’re just not implemented to that capacity and reliability (and other validation requirements). Hundreds of thousands already implement for unsafe and unhealthy work conditions in industry. Come on… you can buy in.
I agree… some operations having programmable or remote controllable systems with an equivalent field of view and vision systems as well as other sensor systems that a pilot or astronaut has is a gap that can be more critically assessed and I am observing the technology is coming to market… though not in the compact size reliable lifecycle operation specification capabilities.
Sure, latency is an issue… I’m sure there are ways to mitigate… that speed of light limit and baud rate.
Amazing, how remote control’ed full scale aircraft were around in the 1930’s and refined with vision systems in the 1940’s.
Now anyone can purchase a drone and robot and even launch a satellite into space if they really really want to. I think there are cost effective systems capabilities with the investment to further the vision of space travel to be more feasible versus cover stories for other funds operations. AI and other robotic implementation are better off the planet too for developing those environments IMO… since that will help keep people busier in healthier and safer ways on the planet earth. The social dynamic cycles are a different beast however.
Dextre already exists and there are other more cost effective than the space shuttle and lab system capabilities I’m confident that can be implemented in the future.
http://www.asc-csa.gc.ca/eng/iss/dextre/default.asp
Here is some other information that I think is a step forward to a safer, healthier and more value added future in space:
http://www.thespacereview.com/article/3548/1
https://er.jsc.nasa.gov/seh/robots_in_space.htm
Seems underwater development is another area of opportunity also leaving me wonder how many amateur submarines there are out there and underwater robots.
* Spoiler alert! Do not read this comment any further if you enjoy space helmets in movies. *
There is one thing that I cannot ‘un-notice’: the /inside/ of every space helmet is perfectly illuminated. Example: top of page.
For a movie that makes a lot of sense because you can see the face, human, alien or Golden Retriever. For a useful helmet it might make more sense to keep the inside dark and illuminate the outside.
There is no other way to show the face of the actor in spacesuit than to illuminate it with some lights. The movie studio pays lots of money for that face to be in that helmet, so it must be seen. Also bunch of faceless people would make movie a bit more creepy for some…
See also: motorcycle helmets in movies.
I think Bowman only had a few seconds. At low pressure, oxygen diffuses OUT of the lungs very rapidly and and you have 5 to 15 seconds to take action before unconsciousness. There are examples from rapid loss of pressure in aircraft. Pilots can not reach the oxygen mask beside their seat in time. You can recover from longer, but with oxygen leaving much faster than usual, recovery is less likely.
– Yeah – said he was conscious for 15 seconds – was that including the 10 seconds it took to depressurize the suit through the hole, or after? – if including depressurize, he only made it seconds at ~0 psia.
The fictional Bowman was prepared and could have hyperventilated in preparation. For pilots, there’s a delay in figuring out what the problem is or there are a lot of other distractions, such as the sudden formation of a fog bank in the cockpit.
“spaceships don’t constantly accelerate while their engines are running”
Really? How do you manage that?
If a reaction drive is running, there must definitely be a change in velocity… ∆v is acceleration I do believe
The point was that movies like Star Wars show the ships with their engines running the whole time, yet they travel at a constant rate of speed (until they veer into the side of the trench on the Death Star).
In a movie, there’s no way for you to know whether they’re at a constant speed or not.
Erm… check their speed against their surroundings, like the giant death start with nice regular markings?
The engines could just be idling to generate power while venting exhaust at low pressure. Then the pilot hits the TURBO BOOST button and three C02 bottles spew vapor out the back of the model Viper. ;)
Context is everything. I’m saying in the movies that happens all the time not in real life.
A little more related to space… with some SR-71 action and great narrative:
https://www.youtube.com/watch?v=nRyIGTkcmII
I thought there was a high altitude balloon accident… though may be thinking images from something related to aliens and the more real causation for the look due to accident(s). For now, swollen right hand incident and some excellent details on the high altitude jumps, in particular Colonel Joseph W. Kittinger II:
https://news.nationalgeographic.com/news/2012/10/121008-joseph-kittinger-felix-baumgartner-skydive-science/
https://www.youtube.com/watch?v=Y2Wferg4o7A
Not finding the alien head images I recall seeing years ago (I keep thinking they were balloon or some test pilots with swollen head injuries or something like that). I did find this and am wondering where is the Navy documentation relating to human experiments underwater is since I wasn’t exposed to since they were more deviants around us?:
https://www.youtube.com/watch?v=DQgq0R77pxU
“Son, what would you like to be when you grow up?”
“I wanna be a crash test dummy!”
People say that sort of stuff, like that there would be no sound in space, because they don’t understand either what sound is, or what space is. It is a patently ridiculous statement.
Does “space” lack gases? Or are they merely thin? Merely thin. Thin enough that audio vibrations don’t usually bump into their neighbors. But that usually isn’t the same as always; whenever you have a localized increase in gases, you’ll have sound transmission.
Lets says somebody is doing an EVA, and their helmet suddenly pops off. Where does the gas go? Does it just vanish? No, but unfortunately for this person it also doesn’t stay put. It expands. And it continues expanding. So the person is yelling, “ahhhhhhhhhhhhhhhhh!” as the air escapes. The air molecules aren’t vibrating against each other to transmit sound, but they are individually vibrating, and that includes the sound of the scream. And they’re expanding. See, that is a big different than the pundits in the “that’s impwosssibul” crowd miss; on Earth the air is mostly sitting in place, so if the neighbors don’t vibrate, there is no transmission of sound. But in space, any released gasses expand; they accelerate on their own, it is the default thing that any gas is going to do. So any released gas is flying away from the source, and potentially vibrating with any sound it picked up while the density was still high enough. As that shell of gas is expanding, individual particles collide with the nearby space craft that was the source of the EVA. Before that collision, the gas continues vibrating with the sound of the scream because there is nothing else damping the vibration. When the collision happens, that vibration is transmitted into the ship. You could possibly hear the scream; you’d potentially find it frequency-shifted onto a wide variety of instruments, too.
And it gets worse with explosions; if you ask a simple question like, “wait, what is an explosion, anyways?” You might get a definition like:
“An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases.” (wikipedia)
What happens to those gases? Right, as above, they expand. In a space battle scene, if you fire an explosive at another ship and it hits, there will be one shell of gases expanding from the explosive, and if you destroyed the other ship, its life support gasses will also be expanding. You’ll hear each of those events as its gas shell hits your hull.
So pedants, please, learn you some sciency stuff, and stop complaining that explosions don’t make a sound in space. That isn’t true, and it isn’t what the scenes get wrong. The correct complaint is, “that isn’t what explosions sound like in space, or when!”
A single gas molecule in a vacuum does not vibrate, it moves according to Newton’s laws of motion: unless acted on by gravity, an electric field, or a magnetic field, it moves in a straight line.
Vibration (Brownian motion) of a molecule in a gas is caused by molecules bouncing off each other. A sudden release of gas in a vacuum results in the gas becoming thin quickly; within a few feet there isn’t a high enough density of molecules for there to be a significant amount of bouncing – not enough to have Brownian motion, let alone the massive correlated varying motion we’d call “sound”.
We have to consider terminology in regards to relative and absolute… I guess is the way to detail. Basically… a lower pressure environment or a perfect vacuum with zero pressure.
https://en.wikipedia.org/wiki/Vacuum#Measurement
You’re gonna need a time function there; don’t just wave your hands and pretend the gases go from having neighbors to not having neighbors, because “space.”
When your suit pops, yeah, the sound won’t last long; aka far. But nearby objects, like the ship you’re servicing, aren’t far. When the released gas hits the ship, it isn’t yet as diluted as you say.
It gets worse because not only is there not a sudden transition in this case, quantum mechanics suggests none of the transitions in anything are that neat or clean, everything is fuzzy at the edges.
No, gases don’t go from “having neighbors to not having neighbors, because “space.””, and there’s no need to handwave anything “quantum” into the argument. This is simple vacuum physics.
The mean free path increases so quickly with dropping pressure, there’s very quickly virtually no interaction between the molecules hence no “sound”. If you have, say, 1 liter of air in your helmet surrounding your head, the pressure of that air will have dropped to 1mbar when the expanding shock wave reaches 1m. Mean free path is already ~0.1mm at 1mbar. Compare that to the size of an air molecule, ~0.5nm. At ambient, the mean free path is of order 100nm, ie the molecules hit one another after maybe 200 molecule diameters.
There’s just not much interaction going on between the molecules any more, they basically fly ballistically outwards.
The wave you get this way is a shock wave basically an explosion.
(This is one of the classic ways to experimentally generate a shock wave, Google shock tube).
If that shockwave hits something, *that* can generate sound (see my other answer below)
Agree. “The air molecules aren’t vibrating against each other to transmit sound, but they are individually vibrating, and that includes the sound of the scream.”
It doesn’t work that way. Gases don’t work that way.
Never before has anyone written so much, and said so little.
Wait. You say “because they don’t understand either what sound is” and then “The air molecules aren’t vibrating against each other to transmit sound, but they are individually vibrating”?
Sorry, but I’m not sure *you* fully understand what sound is. While molecules do vibrate individually (read up on molecular vibration eg on Wikipedia: interesting stuff about chemistry and spectroscopy), this has nothing at all to do with sound.
Sound in gas is not vibration of molecules, but a pressure wave.
Where you’re right is that since pressure waves in gas are sound, an explosion in space *can* indeed make a sound: when the shell of expanding gas hits your spaceship’s hull or your spacesuit’s helmet, it causes a vibration, similar to the membrane of a microphone. This vibration in turn can cause a pressure wave in the air in your spaceship or helmet or whatever, which you can hear as sound.
Depending on the various pressures, stiffnesses, and speeds, the impedance mismatch can be pretty drastic though, so in most situations probably not much makes it through.
Btw, [Cody’s Lab] has a neat video in which he explodes a fire cracker in a vacuum chamber. Not quite representative (fire cracker is in contact with the walls, exclusive gases fill chamber to non-negligible pressure), but pretty neat anyway.
Cody’s Lab does have a great video on the subject. I think it was a blasting cap from his mine.
I do agree it isn’t actually “sound” in between being released, and when it is transmitting vibrations to your hull. But while that contact is happening, it is sound; eg, when you hear it, that part is the sound. And you will hear it, if you’re close enough and listening to your hull vibrations.
The impedance mismatch is why it is probably the communications person who hears it phase-shifted as the gas hits various instruments.
I guess the point is that within your hull, you will hear the bang from the shockwave hitting your hull, but you will not hear the “aaahhh” from the guy in the explosively decompressing spacesuit. His voice does not create a sound wave superimposed on the shockwave.
(Pretty much by definition, as shockwaves are supersonic)
While browsig around after treading this post I stumbled into:
“Do not attempt to give food, drinks or medical supplies to occupants”
Really made me think of a zoo :)
https://upload.wikimedia.org/wikipedia/commons/d/d4/Hyperbaric_escape_module_20151203_133659.jpg
My great uncle, Nick Piantanida, died from similar effects during an attempted high-altitude balloon jump back in the 60’s. ESPN did a great documentary about it called Angry Sky. I believe it’s on NetFlix.