In scores of science fiction stories, hapless adventurers find themselves unwittingly introduced to the vacuum of space without proper protection. There is often an alarming cacophony of screams and gasps as the increasingly bloated humans writhe and spasm. Their exposed veins and eyeballs soon bulge in what is clearly a disagreeable manner. The ill-fated adventurers rapidly swell like over-inflated balloons, ultimately bursting in a gruesome spray of blood. As is true with many subjects, this representation in popular culture does not reflect the reality of exposure to outer space. Ever since humanity first began to probe outside of our protective atmosphere, a number of live organisms have been exposed to vacuum, both deliberately and otherwise. By combining these experiences with our knowledge of outer space, scientists have a pretty clear idea of what would happen if an unprotected human slipped into the cold, airless void.

In the 1960s, as technology was bringing the prospect of manned spaceflight into reality, engineers recognized the importance of determining the amount of time astronauts would have to react to integrity breaches such as a damaged spacecraft or punctured space-suits. To that end, NASA constructed an assortment of large altitude chambers to mimic the hostile environments found at varying distances above the Earth, accounting for factors such as air pressure, temperature, and radiation. Adventurous volunteers were subjected to simulations of the conditions found several miles up, and a handful of animal tests were conducted with even lower pressures.

Using the data from these experiments and their knowledge of outer space, scientists were able to make some reasonable conclusions about how the human body would respond to sudden depressurization. A series of accidents over the years proved most of their extrapolations to be accurate. In 1965, in a space-suit test gone awry, a technician in an altitude chamber was exposed to a hard vacuum. The defective suit was unable to hold pressure, and the man collapsed after fourteen seconds. He regained consciousness shortly after the chamber was repressurized, and he was uninjured. In a later incident, another technician spent four minutes trapped at low pressure by a malfunctioning altitude chamber. He lost consciousness and began to turn blue, but escaped death when one of the managers kicked in one of the machine’s glass gauges, allowing air to seep into the chamber.

“…the orbital module was normally separated by 12 pyrotechnic devices which were supposed to fire sequentially, but they incorrectly fired simultaneously, and this caused a ball joint in the capsule’s pressure equalization valve to unseat, allowing air to escape. The valve normally opens at low altitude to equalize cabin air pressure to the outside air pressure. This caused the cabin to lose all its atmosphere in about 30 seconds while still at a height of 168 km. In seconds, Patsayev realized the problem and unstrapped from his seat to try and cover the valve inlet and shut off the valve but there was little time left. It would take 60 seconds to shut off the valve manually and Patsayev managed to half close it before passing out. Dobrovolsky and Volkov were virtually powerless to help since they were strapped in their seats, with little room to move in the small capsule and no real way to assist Patsayev. The men died shortly after passing out. […] The rest of the descent was normal and the capsule landed at 2:17 AM. The recovery forces located the capsule and opened the hatch only to find the cosmonauts motionless in their seats. On first glance they appeared to be asleep, but closer examination showed why there was no normal communication from the capsule during descent.”

When the human body is suddenly exposed to the vacuum of space, a number of injuries begin to occur immediately. Though they are relatively minor at first, they accumulate rapidly into a life-threatening combination. The first effect is the expansion of gases within the lungs and digestive tract due to the reduction of external pressure. A victim of explosive decompression greatly increases their chances of survival simply by exhaling within the first few seconds, otherwise death is likely to occur once the lungs rupture and spill bubbles of air into the circulatory system. Such a life-saving exhalation might be due to a shout of surprise, though it would naturally go unheard where there is no air to carry it.

In the absence of atmospheric pressure water will spontaneously convert into vapor, which would cause the moisture in a victim’s mouth and eyes to quickly boil away. The same effect would cause water in the muscles and soft tissues of the body to evaporate, prompting some parts of the body to swell to twice their usual size after a few moments. This bloating may result in some superficial bruising due to broken capillaries, but it would not be sufficient to break the skin.

A NASA altitude chamberWithin seconds the reduced pressure would cause the nitrogen which is dissolved in the blood to form gaseous bubbles, a painful condition known to divers as “the bends.” Direct exposure to the sun’s ultraviolet radiation would also cause a severe sunburn to any unprotected skin. Heat does not transfer out of the body very rapidly in the absence of a medium such as air or water, so freezing to death is not an immediate risk in outer space despite the extreme cold.

For about ten full seconds– a long time to be loitering in space without protection– an average human would be rather uncomfortable, but they would still have their wits about them. Depending on the nature of the decompression, this may give a victim sufficient time to take measures to save their own life. But this period of “useful consciousness” would wane as the effects of brain asphyxiation begin to set in. In the absence of air pressure the gas exchange of the lungs works in reverse, dumping oxygen out of the blood and accelerating the oxygen-starved state known as hypoxia. After about ten seconds a victim will experience loss of vision and impaired judgement, and the cooling effect of evaporation will lower the temperature in the victim’s mouth and nose to near-freezing. Unconsciousness and convulsions would follow several seconds later, and a blue discoloration of the skin called cyanosis would become evident.

At this point the victim would be floating in a blue, bloated, unresponsive stupor, but their brain would remain undamaged and their heart would continue to beat. If pressurized oxygen is administered within about one and a half minutes, a person in such a state is likely make a complete recovery with only minor injuries, though the hypoxia-induced blindness may not pass for some time. Without intervention in those first ninety seconds, the blood pressure would fall sufficiently that the blood itself would begin to boil, and the heart would stop beating. There are no recorded instances of successful resuscitation beyond that threshold.

Though an unprotected human would not long survive in the clutches of outer space, it is remarkable that survival times can be measured in minutes rather than seconds, and that one could endure such an inhospitable environment for almost two minutes without suffering any irreversible damage. The human body is indeed a resilient machine.



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So, if you're ever have a bad day in space; remember to use the best sunscreen available. So when your suit rips or you have an itchy nose and take off your helmet, then remember; Exhale and hope someone has pressurized oxygen in their back pocket.

It's amazing how resiliant the human machine is, instead of seconds of living in the vacuum of space, you instead have a couple minutes.

Edit

I used the entire text, as there was no where to really break it and also get the reasoning from the topic title. You don't skimp out on facts~

What you've quoted is essentially true.
No, human beings won't "explode" when exposed to vacuum. Dramatizations of this concept are woefully incorrect.

However, sunscreen and sunburn potential are the least of one's problems in exposure to vacuum.
You have the same amount of time to live as you would in any anoxic situation, however, the effects of vacuum accelerate certain things, like unconsciousness, which will occur within 8 to 12 seconds upon complete exposure to vacuum.

Letting the air out of one's lungs is essential to avoiding serious damage to the very soft and tender tissues of the lungs. The tendency to inhale deeply and hold one's breath, which seems rather natural, will most assuredly cause some serious damage to the lungs, even if you can manage to get re-pressurized within a short amount of time.

If an astronuat lost all pressure while in space, he would have to be moved into a pressurized atmosphere within a matter of a couple minutes in order to have a chance. And, have a chance he or she would in such a case. But resisting the vacuum by holding the breath would, even if someone was there to get you repressurized in a few minutes, would result in some serious problems.


Decompression involves a loss of consciousness within a matter of seconds, and permanent brain damage results within a matter of perhaps 4 minutes. There are other physiological effects which occur, of course, most of which can be recovered from. But, 4 minutes without oxygen is enough for most people to expire. They'll be unconscious for the vast majority of that time, but they will expire.

They key is not only pressurized oxygen. It's restoring the pressure of the body itself.

The air within your lungs would expand at an enormous rate, rupturing your lungs - which is the only way that you'd literally explode from the inside out.

That's true to an extent. But exploding implies an immediate rupture, a violent event. That is not what happens. I will agree that the effects are quick, but to describe it as an explosion is a little bit of a stretch....

One of the few science fiction films to get this right is 2001 A Space Odyssey. The helmetless Dave Bowman manages to transfer from a pod to the airlock in the few seconds he has before he passes out. Being written by Arthur C. Clarke ensured that this film was far closer to fact than we see in most Hollywood sci-fi.

We were told in school that the human body would implode. You learn something new everyday.

What about the temperature in vacuum, how does the freezing conditions affect the human body?

^Space is cold, but you need to remember that it's a vacuum. Your body loses most of its heat through conduction with the air molecules around you (they "leech" the heat from your body). In space you're only going to be losing heat through radiation which is a fairly slow process. You're going to be dead from the other effects before you freeze.

Because of the lack of pressure, any exposed liquids (saliva, sweat etc.) would boil from your skin. To add to the problems of the oxygen in your lungs expanding, I would imagine that the pressure gradient would force your blood to lose its gases at the lungs.

The thing people forget when talking about the vacuum of space is that the difference in pressure from the human norm is only one atmosphere. Divers regularly experience much greater pressure gradients.

I was taught that the definition of explosion was a large amount of high temperature gas escaping exponentially within a few seconds.

Yep, all the air in your lung would expand and rupture your lungs.The natural responce would be to tak a big gulp of air, full lungs would the undoing of the astronaut.

Waspie, there was one fallacy there.
Although it rather magically portrayed things in very accurate fashion, and Boman would've been at the edge of consciousness by the time he re-pressed that airlock, tat big sucking gasp of air and the forceful holding he did prior to blowing the hatch was a sure ticket to lung damage that probably would've left him coughing up blood and in considerable pain...

No, space has no temperature (nothing to be hot or cold). Your body might feel cool to the touch because water on or in the skin the water will evaporate.

I dunno but I was always under the impression that you would implode rather than explode. I don't know though, it is just a thought. All these thoughts, jeez.

Peace,

-T

Try to visualize it by looking at what happens to a high altitude balloon as it ascends into lower pressures in the high atmosphere.
The balloon expands to a great size...because the pressure outside of it is lower than the pressure inside it.

Space does have a temperature, roughly 2.7 Kelvin. People just sometimes find it hard to understand the differences in heat transfer (Radiation/Conduction) etc.

The answer so far imply that you'd little more than

1) PVC gimp suit - to hold you together
2) several layers of tin foil (anti-radiation stuff)
3) an old fashioned divers helmet (though the pressures would be reversed and not as severe)
4) some decent oxygen/air tanks
5) a cool set of sunglasses

......and you'd be fine, just take a roll of duct tape if you accidentally rip your rubber gear.

bit sweaty though...

et voila,

http://www.fi.edu/pieces/hiley/images/phot...t-mercury7a.jpg

though the suit looks a little bulkier in this pic,

http://www.sti.nasa.gov/tto/Spinoff2006/im...8-017_img_6.jpg

if anything you could argue (possibly) thats its safer than diving - no need to decompress or special air mixtures (I think....)

I'm not quite sure what you're getting at here...but:

They are different suits...much different.





Uh, no you couldn't argue that.
In spaceflight EVA, you do need to decompress, for hours, prebreathing all night to prepare for the endeavor. Further, a hole in your wetsuit ain't gonna cause you a really bad day at 300 feet down. In space, a hole in your spacesuit could cause you a really bad day in about 15 seconds in vacuum.

Yes, that is what happens to everything in space. The sun is continually imploding. If it were to explode which may have happened before, that would cause another 'big bang.'

The Sun isn't imploding, it's being pulled in on itself by gravity, but this is balanced by the outwards pressure of the hot gas. An equilibrium point is reached which is why it stays a constant size (during this moment of it's life at least).

Things don't just implode because they're in space, I don't know where anyone got that idea from...

I think in space you have equal pressure on all sides according to the mass. Gravity is external. What about the talk of a star dying and forming a black hole?

The level of ignorance of any kind of scientific knowledge displayed by your posts is astounding...


Cz

Aaaahhhh...




gregg...look.


In space you have no pressure on any side of you. It's a vacuum. That means, no pressure. It doesn't matter what your mass is.

Take a balloon, and put it inside of a vacuum chamber (most high school science labs have on of these things...at least they used to back in the "old days"). As they suck the air out of it, the baloon, rather naturally, EXPANDS!

Think of a human as sort of a really complicated balloon, with all sorts of some what sealed systems...you'll get the picture.


Think about it!
Why do you think we enclose all those EVA astronauts in pressurized suits before they leave the ISS on the way outside? If they didn't have those suits and they went out into vacuum...well, poof!...so to speak...a very bad sort of "exploding" kind of experience...

I CAN SEE PERFECTLY WELL! THE NEXT TIME YOU GO OUT FOR A SPACEWALK, LET ME KNOW SO I CAN GET SOME INFO FROM YOU!!!!!!!!!

There you go. Look gregg, NO HANDS!

OK, gregg, done my spacewalk.

What would you like to know???!

i'm surprized that nobody remembers the experiments of one Joseph Mengele. ( the angel of death )
and a little bit of history. the united states started feeding the germans after ww2 on an agreement for all the scientists and their work.
Wernher von Braun was the head of the V2 project and under his orders put hundreds of people to death ( worked them to death, some of the worst jobs he prefferd to use children for their small hands ) but i am getting off topic.

any how Joseph Mengele did the vacume experiments on living people. subject placed in vacume chamber and subjected to conditions to cause death. there by making the first dicoveries at how resiliant the human being really is.

never forget that these 2 nazis did all the ground work for the space race, and all of their experiments were done at the cost of human lives. ( by means of torture )

Joseph Mengele, look into his work. you might be surprized.

You would implode at great depth.

And so forth. In my town, they put down strays with a vacuum type euthanasia. It is easier on personnel, for one thing. It is not fun, but it helps folks deal tolerably with too many small animals.

I am caring for my sister's cat, and it takes a lot of patience. Fortitude and patience.

As for the history and science of atmospherics, I don't know exactly how the science grew.

But, I did suspect that in WWII, the allies put in cabin pressurization to maintain the safety of some aircrews.




June 1944. Shown is the rear pressurized cabin of a B-29, equipped with four bunks to give crew members a chance for rest on a long mission. This was an important factor in combating flight fatigue.

Don't want to forget this-

Philip Drinker (December 12, 1894. Haverford, Pennsylvania). Industrial hygienist who invented the first widely used iron lung in 1928 with Louis Agassiz Shaw.

After graduating from Princeton in 1915, Philip Drinker trained as a chemical engineer at Lehigh for two years. Drinker was hired to teach industrial illumination and ventilation at Harvard Medical School and soon joined his brother Cecil and colleagues Alice Hamilton and David L. Edsall on the faculty of the nascent Harvard School of Public Health in 1921.

The first iron lung was used on October 12, 1928, at Children's Hospital, Boston, Massachusetts, in a child unconscious from respiratory failure; her dramatic recovery, within seconds of being placed within the chamber, did much to popularize the "Drinker Respirator." Wiki

In other words-



Cite

Very interesting I always wondered about those sci fi movies...

Please can you explain the boiling bit? (blood and such...)


Thanks,
Star

This is turning into an interesting topic...

THe iron lung only works in the way it does (IMO) because when there is <atmosperic pressure (1 Bar-ish) in the iron lung - the persons lungs expand like a balloon due to the higher pressure outside the lung.

When the lung pressurises, the reverse occurs.

With there being a vacuum (for all intents and purposes, ignoring the odd atoms of gases) - there is nothing to exert pressure on the lungs - the air can't be 'pushed' out as such (via the cavity in which the lungs are contained being compressed) - however there would be a pressure difference over the lung/chest walls, so it depends on the chest walls ability to contain the pressure, ie how well are people built? After that - how well can a person 'hold their breath'.



other might do this better. Going through all the usual, highly regarded sources (ie wiki...)

think the question may be best approached by broadening the question.

Liquids - they have boiling points and freezing points. When a liquid is heated, it may eventually reach its boiling point - and thereafter vapourise. At lower atmospheric pressures - the boiling point is lowered, therefore it will boil when it hits the temperature.

[b]BUT/b] (out on a limb here)

boiling is the means of the liquid getting rid of excessive heat which is being continually applied to it (forget the chemistry/physics off my head) - but as soon as you remove the heat - it pretty well stops boiling. ie
4 deg c - water is a liquid
95 de c - water is still a liquid, albeit quite hot - with some steam.

ie - shove it over its boiling point - it suddenly turns into a boiling mass.

Onto people - humans (I assume) have some degree of elasticity in their skin - but air is only really present in the lungs etc - so how much will people really expand in space? Because the more the body expands, the pressure inside will lower - however a human is 37 deg c - so water within the body can only boil when the pressure within the body drops to such a level that its boiling point drops below 37 deg C.

http://en.wikipedia.org/wiki/Boiling_point

You'll notice they've helpfully left water off the graph.

Another interesting property of water (scratching my head here) is hydrogen bonds - these are weak electro something or other bonds which keep the molecules attracted to one another (I think) - when water 'freezes' the molecules go into funny 'rings' - the hydrogen bonds increase the space between the molecules - reducing its density- and hence the solid (ice) floats.

In most other things in nature - the solid goes down (being denser), the liquid floats - however the reverse occurs in water.

going to bed.....

feel free to ridicule......

"THe iron lung only works in the way it does (IMO) because when there is <atmosperic pressure (1 Bar-ish) in the iron lung - the persons lungs expand like a balloon due to the higher pressure outside the lung.

When the lung pressurises, the reverse occurs."


The point of the Drinker Respirator is to illustrate for positive, constructive, and comparitive purposes as to the state of scientific and practical engineering know-how in the United States, as early as 1923.

I think your understanding of history is a little influenced...

Von Braun put people to death?
I think a little more investigation is in order.




Von Braun was a nazi because he had to be.
He was also imprisoned by the SS because he was steadfast in his wish to speak of space exploration rather than designing weapons delivery systems. He also made comments in inappropriate places regarding the German's progress in the war, which he knew was not too good.

You might be interested to know that Mengele had nothing to do with space exploration...he was a war criminal and a whack job, and that Von Braun ran from the Nazi's in 1945 (knowing full well that Hitler was toast) with a death squad persuing him, and surrendered to the Americans as soon as he could find them. It was a good choice, for him, and for us.

Von Braun was a naturalized American citizen, and was the key to our successes in space exploration.

History is sometimes important to understand!

the boiling point of water decreases with a decrease in pressure.
at sea level ( 1 bar ) the boiling point of water is 100C, but at the top of mount everest the boiling point is somwhere around 40C.
you cant make a cup of coffee on mount everest.
the lower the pressure, the lower the tempurature for boiling to occure.
does anyone remember when the space shuttle ejected their waste water and it froze before it was completely out?
they had to wait for it to sublimate ( go from solid to gass )
in space the boiling point of water is below its freezing point.

Perhaps you could relate this to the concept of humans exploding in space?

OHHH... Ok that makes sense now!

Thanks so much for that explaination.. (Seems I need to brush up on my science )

MID I was trying to understand why blood and liquids boiled in space (as per previous posts) but now I get it...

humans are mostly water.
so each cell being a little water bag, as long as the bag does not break, then there would be a chance.
it does after all take time for matter to give up energy. but at the least there would be frostbite on the extremities.
lungs exploding would be less of a concern then your eyes poping out of your head.
your lungs are surounded by a rib cage ( surprizingly strong ) whereas your eyes are open to the elements.
and being bags of mostly water, well they might explode, or freeze. depending on weather or not you were facing the sun or not ( the incedent with the shuttle, the ejected the water on the shade side )

the lungs on the other hand, not only having a cage around them ( not that it would be comfortable ) would be able to hold the pressure differance. not much different then blowing up a really tough balloon ( the whole thing about strong men blowing up water bottels has to do with the strenght of their abs, and this is one of the places pressure would try to escape ) other places that the air would try to escape, eustachian tube ( air passage way that allows you to equalize pressure in your ears ) and the lacrimal canals, ( where your tears drain out of your eyes ) but that all depends on how you hold your breath. plugging nose and holding your mouth shut would allow these passages to be open and a subsequent loss of pressure ( and very painfull i would imagine ) as opposed to trying to hold your breath by the closing of your epiglotis, or other parts of the back of your throat, would seem to be the better way to try and hold your breath.
but either way your eyeballs are still relativly unprotected, and a part of the brain, so the pain that it would cause would really give you the urge to scream. in which case you are totaly hooped.
but i don't think you would explode. thermal dynamics just wouldn't support it. to much that has to boil all at once. pressure in the body ( on a celular level ) has to escape, and the body holds heat, as well as generates its own. boiling away from the outside in, hmm there is a concept in pain.

this is kinda fun, speculation on gruesom ways to die.