Total Recall: Does Mars make your eyes and tongue explode?

Factual Questions
1

Watching a rerun yesterday of Total Recall. The scene at the end where Bad Guy Number 1 suffers thru about 5 minutes of excruciating pain before his eyes, tongue and skin explode got me thinking.

I was under the impression that this kind of thing happens in a vacuum. Mars is not a vacuum. In fact a human can survive on the planet with a breathing mask and warm clothes. No need for a complete VACC suite like the Moon.

So, in Total Recall, would the bad guy, Arnie and his girlfriend instantly die from the sub-zero temperature? Or would their eyes/skin eventually exploded as depicted?

2

Mars isn’t a vacuum, but it isn’t a thick atmosphere either. I think the pressures involved are much closer to a vacuum than Earth is. So a human body’s reaction would probably be similar to its reaction in a vacuum. Not sure if that includes exploding eyes and tongues, however.

3

Mars’ surface atmospheric pressure is about 1/100th that of Earth’s. That would be a vacuum of about 29.6" compared to interplanetary space at 29.9" of vacuum. Mars is close enough to vacuum for many purposes. That said, the exact effects of hard vacuum on the human body are not well-understood, though they would certainly be much less dramatic than the movies. Any organs with no air in them are not going to expand, such as the eyes and tongue, so there goes that idea.

4

I thought that was the lamest part of the movie. Their eyes bulge out and then go back in, and they are no worse for wear?

5

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

6

Not only does Mars not do it, neither does a Total Vacuum. Arthur C. Clarke made a point of this around the time that 2001: A Space Odyssey came out, because Dave Bowman goes out of his space pod without his helmet in that flick, of course. Clarke had already used the idea a few times before in his novel Earthlight and one or two short stories.Kubrick’s film demonstrated that going out in a vacuum, and without sound, could be very dramatic and visually arresting while still being scientifically accurate.

Unfortunately, other filmmakers think that noise in space and exploding heads in vacuum are visually arresting and cinematically impressive, so we have the scenes in Total Recall and Outland. Martin Caidin (a test pilot, who should know better) got it wrong in his book Four Came Back. I think Pierre Boulle had a body explode in Garden on the Moon, too.

Well, in the case of Total Recall I can make a good case that all the Martian scenes are really dreams or semi-implanted memories (certainly the first sequence, where Arnold breaks his face plate, is a dream), so it doesn’t “really” happen in Total Recall.
It’s still bad science. See Clark’s essay in his book The View from Serendip.

7

Cecil

8

Not only does Mars not do it, neither does a Total Vacuum. Arthur C. Clarke made a point of this around the time that 2001: A Space Odyssey came out, because Dave Bowman goes out of his space pod without his helmet in that flick, of course. Clarke had already used the idea a few times before in his novel Earthlight and one or two short stories.Kubrick’s film demonstrated that going out in a vacuum, and without sound, could be very dramatic and visually arresting while still being scientifically accurate.

Unfortunately, other filmmakers think that noise in space and exploding heads in vacuum are visually arresting and cinematically impressive, so we have the scenes in Total Recall and Outland. Martin Caidin (a test pilot, who should know better) got it wrong in his book Four Came Back. I think Pierre Boulle had a body explode in Garden on the Moon, too.

Well, in the case of Total Recall I can make a good case that all the Martian scenes are really dreams or semi-implanted memories (certainly the first sequence, where Arnold breaks his face plate, is a dream), so it doesn’t “really” happen in Total Recall.
It’s still bad science. See Clark’s essay in his book The View from Serendip.

9

But a mistake in the movie is when Dave holds his breath. True that one could survive a few minutes but not hold one’s breath.

10

But your tongue has blood in it, and blood has dissolved gasses which form bubbles if the pressures low enough, right? Isn’t that how the bends works? I’m not refuting the “no explosions” hypothesis…

11

Bubbles would form in your tongue, eyes, or wherever else if the vapor pressure of water at body temperature was greater than the pressure inside that body part. In the vacuum of space or the almost-vacuum of the Martian atmosphere, water would spontaneously bubble - boil, that is. But it only takes a little pressure to stop it.

I think I remember that the water has a vapor pressure of 2% of an atmosphere at body temperature. That’d be 0.3 psi or 10 inches water column. It’d be easy to contain such a pressure even in soft body tissues, though you might get some bubbles. Perhaps foaming in the circulatory system - what I understand the bends is - would be a problem. But getting back into pressurization would stop the process.

I think the 2001 movie scene looks correct. I guess further that the biggest problems for somebody doing what Dave did would be:

  1. Popping of the ears if the tubes weren’t open.
  2. Injury to the respiratory system if one reflexively tried to stop the sudden exhalation.
  3. The bends, more or less according to how long one went out for.
  4. The mother of all sinus headaches if one were congested.
  5. Some pretty sudden gas pains and farting depending on how much gas was in there to begin with.
12

Your tissues are always at a higher pressure than the outside atmosphere. This is actually important im the biomechanics of breathing, fluid balance in terminal capillaries, etc. Any serious physiology text will explain why.

You only need 47.1 mmHg of pressure to counteract the vaporization of water at body temperature. If you have a fairly impermeable surface membrane, like skin or mucous membrane (saliva is an specific fluid created by glands, the actualy permeation fo water in the pink mucosa is small and slow) then Martian surface atmospheric pressures of 53.2-64.6 mmHg would be more than enough to prevent boiling. You would have more problems with dissolved gases bubbling out, but even a relatively small amount of that will equalize the pressure.

That’s why deep sea divers who acclimate to several atmospheres of pressure and suddenly decompress (e.g. return to the surface or have a catastrophic failure in a decompression tank) look pretty normal when they get the bends. Their eyes don’t bug, their tongues don’t swell, etc. – and they are experiencing a far higher pressure differential – sea water is much denser than air, so a diver experiences roughly 1 atmosphere of overpressure for every 10m of depth. A deep diver may be acclimated to many tens of atmospheres of pressure. If dropping to 1 atm doesn’t make them bug out, the Martian atmosphere is nothing

13

If you want a reasonably accurate portrayal of what happens to somebody on the surface of Mars with a (partially) unpressurized suit, read Greg Bear’s Moving Mars.

14

I hate to say this, but…do you have a cite for that?

Ranchoth
(…Besides a certain Babylon 5 episode. Though it was a good episode, at that.)

15

None whatsoever. I should of prefaced that by saying thats what I think will happen based on sci-fi books I’ve read. Thats why I seek the wisdom of the Straight Dope.

So, essentially, in situation like Total Recall, the cold would of killed Arnie before any kind of suffucation occured. And the exploding body parts would really have been the bends?

Thanks all.

16

I believe that Kim Stanley Robinson’s Mars Trilogy (a fantastic read, IMO) also deals with the issue in a pretty accurate and scientific manner.

17

Breathing would be a very real problem.

According to NASA’s “educational” site on Mars, the Martian atmosphere is 95.32% carbon dioxide, and only .013% Oxygen. Since that site also lists Mars air pressure as 8 millibar (6 mmHg) [1] compared to Earth’s (1000 millibars = 760 mmHg). This is a tiny fraction of a sparse atmosphere.

On Earth: 21% O2 * 760 mmHg = 160 mmHg of oxygen
On Mars: 0.013% * 6 mmHg = .00078 mmHg

Hemoglobin, the oxygen carrying molecule in blood, is more than just a simple carrier. It’s affinity for oxygen (it has 4 interacting binding sites) is actually higher in low metabolism, high oxygen environments like the lungs, and lower in more acid, CO2 rich, oxygen depleted environments like metabolically active muscle or tissues. In stead of carrying oxygen like a train carrying boxes, it’s like one of those coal cars tha tactually swivels and dumps its coal over the side where needed.

However, .00078 mmHg is far less oxygen than your tissues, and Hemoglobin is still a passive transport (e.g. train cars can’t ‘magnetically’ pull coal up out of the mine, the coal has to flow downhill into them), and its cooperativity curve says that it basically wouldn’t bind any Oxygen at such a low partial pressure.This would only get worse as the lungs themselves started suffocating (becoming acidic and oxygen starved) and therefore decrease hemoglobin’s affinity [trying to force it to dump oxygen it doesn’t have - which would interfere withits ability to pick up oxygen]

There are other serious complications in breathing the Martian atmosphere. For example, Mars has 95.32% carbon dioxide (vs 0.0314% on Earth) This would decrease hemoglobin’s affinity for oxygen (impeding it’s ability to load up on oxygen) and carbon dioxide is our primary repiratory drive (i.e. our brain senses the level of CO[sub]2[/sub], not O[sub]2[/sub], to decide if it needs to breath harder, so you’d gasp like a goldfish) and our primary pH buffer; too much CO[sub]2[/sub] throws off blood pH

Worse, the level of carbon monoxide (.007%) is half the level of oxygen. Carbon monoxide is a potent toxin that binds hemoglobin more readily [and more firmly] than oxygen does. It also has other undesirable physiological effects. This level of carbon monoxide would be steadily toxic in our own oxygen rich atmosphere. On Mars, it’s ruthlessly deadly.

A good science fiction novel may posit a back pack “concentrator” that scavenges the oxygen from the Martian atmosphere to feed an airtight face mask (simple, bulky and inefficent concentrators are already common: people who need supplemental oxygen at home often use them at home instead of tanks). However, less good SF often assumes that “everything can be miniaturized”, but the facemask is necessary to keep out undesired gases,a nd There’s no getting around the fact that you need to suck in over 7500 liters of oxygen to get 1 liter of oxygen. You can’t ‘miniaturize’ that kind of airflow.

Water may not boil in your blood, but it’s still a huge problem for breathing Martian air. Mars water vapor pressure is 0.03% * 6 mmHg = .0018 mmHg. Humans have problems breathing for long periods at a relative humidity of 4% or more, but Mars is 1000x drier! Your lings sinuses and throat would dry out badly, as well as bleeding precious body water into the thirsty Martian atmosphere. To counteract that, you backpack oxygen scavenger would either need a supply of expendable water for humidification, or some sort of water extraction and recycling device [Long duration divers often lose 8-10 lbs in a single work session: compressed air tanks are also very dry air]

1. Erratum: That site’s figure for Martian air pressure (8 millibars = 6 mmHg) is one decimal point lower than the site I used in my last post. If the lower figure is correct, Martian pressure wouldn’t, by itself, be enough to prevent blood boiing and all that, but it still shouldn’t be a problem, between internal pressure sources like blood pressure, and pressure retention by the structural strength of your connective tissue (think of your skin as a tight pair of spandex jeans)

18

you would need 200 millibars of oxygen to operate well; the atmosphere is 8 millibars, so an unpressurised facemask would just leak;
so you need a pressure suit just to get enough oxygen in your body. The high pressure differential of gas between your body and the atmosphere would be too painful to tolerate without pressurisation;
so you need to increase Martian atmospheric pressure about twentyfold just to be able to use unpressurised breating equipment.

That represents a lot of deliberate cometary impacts.

19

2001 has no mistakes, only imperfections.

20

KP you did your homework, and it was enlightening. Don’t forget however that like Earth, Mars has variations in topography. I seem to remember (no cite available unfortunately) that someone had assigned a “sea level” of sorts in which if you went any higher, the vapor pressure within your lungs would exceed that of the atmosphere and you suffocate like a fish.

Sort of a hijack–I’m not sure what the lowest point on Mars is (a la Death Valley in western hemisphere or the Dead Sea in the east), but I suppose that if the region were hospitable in other ways, it stands to reason that this would be the area where one would place the first manned outpost.