This first thing that Kills a human in Space?

[Zdenka]

Sorry I can't find any information on this.. Never mind the how, but if one were to suddenly find themselves floating naked in the vacuum of space what would be the thing that will kill them first?

Would it be:
* Plummeting Temperature
* Lack of oxygen
* Pressure (or lack of it)
* Radiation
* Fear

I'm guessing temperature since it's extremely cold in space, but my friend says pressure (wtf?!)

 

[Vanadium 50]

As opposed to the second thing that kills a human in space?

 

[Zdenka]

but you can only die once!

 

[Dadface]

You only live twice,
or so it seems,

I think it's pressure...the blood will boil.

Thats probably rubbish.Perhaps an experiment is called for.

 

[Zdenka]

Blood would boil? You mean chill, because it's going to be freezing.

 

[Dadface]

But cooling wouldn't be instantaneous and boiling point reduces with pressure.

 

[moose]

Lack of oxygen would kill you.

 

[Dadface]

Lack of oxygen would kill you.

But how quickly?I just tried an experiment by taking a really high jump in the garden and i am happy to report that I am alive and kicking and as handsome as ever.

 

[Zdenka]

Lack of oxygen would kill you.

A human being can live for 5 minutes without oxygen but at minus 275 degrees Celsius, I think they'd become brittle far sooner than that.

 

[russ_watters]

A human being can live for 5 minutes without oxygen but at minus 275 degrees Celsius, I think they'd become brittle far sooner than that.

Without a medium to carry away heat, cooling doesn't happen very fast.

 

[maze]

A human being can live for 5 minutes without oxygen but at minus 275 degrees Celsius, I think they'd become brittle far sooner than that.

But there are no air particles to conduct or convect away heat, so the only mechanism of cooling would be via radiation (which is slow). Theres also the possibility of adiabatic cooling due to the expansion of your body's volume, but I don't think that would be significant.

 

[Dadface]

<< post edited slightly by berkeman >>
Zdenka have you tried approaching NASA?

 

[HallsofIvy]

After googling on "NASA" "survival in space" I got this from our own dear Scientific American:
http://www.sciam.com/article.cfm?id=survival-in-space-unprotected-possible
Warning: there are descripitions of rather distressing experiments on animals.

They seem to think that internal rupturing from loss of pressure would kill you first.

 

[humanino]

It depends on how fast you establish "vacuum". If it were instantaneous, you would definitely expand, tearing tissues apart. Have you never felt pressure change in your ears ?

edit
The article indeed says that you would not "burst apart". Interesting...

 

[Astronuc]

After googling on "NASA" "survival in space" I got this from our own dear Scientific American:
http://www.sciam.com/article.cfm?id=survival-in-space-unprotected-possible
Warning: there are descripitions of rather distressing experiments on animals.

They seem to think that internal rupturing from loss of pressure would kill you first.

Safe to say the cerebral edema (not to mention the complete loss of all organ function) and loss of oxygen would result in rapid death. Unconsciouness would precede death.

 

[turbo]

Here is an article on that very subject. I don't know how accurate it is, but it seems well -written.

http://www.damninteresting.com/?p=741#more-741

The article references this scholarly article on the medical effects of explosive decompression.

http://www.geoffreylandis.com/ebullism.html

 

[TVP45]

Without a medium to carry away heat, cooling doesn't happen very fast.

I'd suggest The Amazing Madame Zelda using a 1 yard wheelbarrow.

 

[Topher925]

My money is on getting ran over by a satellite.

 

[mheslep]

The article references this scholarly article on the medical effects of explosive decompression.

http://www.geoffreylandis.com/ebullism.html

Clarke got it about right in 2001. You would survive about a ninety seconds, you wouldn't explode, you would remain conscious for about ten seconds.

I have always wondered about Bowman's explosive decompression stunt. I don't expect Myth Busters will be attempting to verify this one with a human show host.

 

[mheslep]

My money is on getting ran over by a satellite.

Or a piece of one:

Space Station Evacuated Due to "Red" Debris Threat

http://news.nationalgeographic.com/news/2009/03/090312-space-station-evacuate.html

 

[Jimmy Snyder]

Starvation? I don't think there's any food out there. And even if there is, there's no wine to go with it.

 

[mbisCool]

Your eyes would dry up a little quickly!

 

[lubuntu]

Wow you guys missed the most obvious one, everyone knows it will be aliens, I'm betting on Klingons or Kzinti.

 

[Astronuc]

One forgot 'boredom' on the list in the OP. There's almost nothing in space, and interesting places are rather far away.

Is one planning a trip soon?

 

[turbo]

One forgot 'boredom' on the list in the OP. There's almost nothing in space, and interesting places are rather far away.

Is one planning a trip soon?

Out in hard vacuum with no space-suit? I doubt that boredom would be much of a problem.

 

[mheslep]

Starvation? I don't think there's any food out there. And even if there is, there's no wine to go with it.

Wow. Remind me to get out of your way when in route to a meal.

 

[Ivan Seeking]

Was Dave's reentry to the station in the movie 2001 possible?

I tried to find a clip but the only one spotted ends right at the critical scene. Basically what happens is that Dave just holds his breath. IIRC, he enables the explosive bolts on his space pod, which blows him into an external entry chamber of the station. At that point he manages to get a door open and move inside the station within a few seconds. He then enables air pressure to the entry containment area.

 

[mheslep]

Was Dave's reentry to the station in the movie 2001 possible?

Very plausible per the link posted earlier, which says you'd have 9-10s before losing consciousness. Bowman did it ~within that time frame, so AC Clarke wrote it correctly.
http://www.geoffreylandis.com/ebullism.html

 

[mheslep]

Appropriate sound clip to attach to locked threads.
http://www.entertonement.com/clips/36481/No-further-purpose-Goodbye

 

[lisab]

Appropriate sound clip to attach to locked threads.
http://www.entertonement.com/clips/36481/No-further-purpose-Goodbye

 

[DaveC426913]

Was Dave's reentry to the station in the movie 2001 possible?

I tried to find a clip but the only one spotted ends right at the critical scene. Basically what happens is that Dave just holds his breath.

Two things wrong with the scene:

1] The pod should have rocketed away in the oppoisite direction.
2] If he actually held his breath (as opposed to letting it all out), then he would have died within the hour from ruptured pleura and alveoli.

 

[mheslep]

Two things wrong with the scene:

1] The pod should have rocketed away in the oppoisite direction.

IIRC he used the pod arms to lock onto some part of the spacecraft .[/QUOTE]

 

[Mk]

*sigh*
Where's Evo? I swear she posts this link in every one of these threads:
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

How long can a human live unprotected in space?

If you don't try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.

Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after ten seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes, you're dying. The limits are not really known.

You do not explode and your blood does not boil because of the containing effect of your skin and circulatory system. You do not instantly freeze because, although the space environment is typically very cold, heat does not transfer away from a body quickly. Loss of consciousness occurs only after the body has depleted the supply of oxygen in the blood. If your skin is exposed to direct sunlight without any protection from its intense ultraviolet radiation, you can get a very bad sunburn.

 

[mgb_phys]

You are though likely to be unconscious in seconds. In a vacuum your lungs work very efficiently in reverse and suck oxygen out of your blood stream.
At 35,000ft (typical altitude for a passenger plane) you have 5-10seconds of consciousness which is why the FAA require pilots to wear oxygen masks above 25,000ft if they are the alone on the flight deck.

 

[TheStatutoryApe]

2] If he actually held his breath (as opposed to letting it all out), then he would have died within the hour from ruptured pleura and alveoli.

I was suprised once when watching a terribly cheesy unrealistic scifi cartoon that they actually got this bit right.

 

[lisab]

But what about the last thing that will kill you in space? I'm guessing...polonium poisoning.

 

[TheStatutoryApe]

But what about the last thing that will kill you in space? I'm guessing...polonium poisoning.

A shark maybe? ;-p

 

[EvanWhaha]

The things that could "Kill Humans In Space" are
1 lack of oxygen or no oxygen
2 blood boiling
3 maybe falling into the sun and you burn up into tiny bits of ashes
4 a alien

 

[Zdenka]

Thanks for the responses, guys! they have been a delightful read. I think an Alien would be one of the last things to be worried about when floating in space! What about getting cancer from the sun's radiation? I think I'd be bringing sunblock on my next trip to the ISS! ;D

 

[sylas]

Also interesting... a few bloggers had fun with this a while back... there is a quiz which let's you calculate how long YOU would live in the vacuum of space.

Warning. This quiz is apparently sponsored by people who want you to read their advertisements, and so you may have to look at an ad of some kind before going to your quiz results. After submitting my quiz answers, I was sent to a page soliciting signups for some social network. Simply clicked on "proceed to quiz results", and I get the answer. Seems harmless, but there you go. If you don't mind such ads, the quiz is at http://www.oneplusyou.com/q/v/space_vacuum.

I'd live, apparently, for 1 minute 23 seconds. The answer comes with an encouraging description of how you can expect to experience those last seconds, according to the quiz author.