KBCraig on June 01, 2010, 03:58:22 am
If you shoot a 20 gauge slug out of a 12 gauge barrel...how fast does the slug exit the barrel?
How fast does a shotgun slug exit a barrel ??  That would depend on the weight of the slug and the powder charge. 

Welcome to the forum, jfrdl. Perhaps you missed it, but the question was a 20 Gauge slug, out of a 12 Gauge barrel. That is, with no wadding or seal, similar rto what happened in this arc of Terra.

Sean Roach on June 01, 2010, 07:14:10 am
He got it.  He glitched on the wadding, but he got it.

SandySandfort on June 01, 2010, 10:44:44 am
Ok, Radiation aside.  Being one mile up and that the moon is 1/5 earth gravity.  Would not  the out rush of atmosphere from the tower propel Normans body beyond escape velocity of the moon.  Thus propelling Norman into a elliptic orbit around the moon ?

The moon's surface gravity is 0.165 4 g, but that nothing to do with escape velocity which is a function of the depth of the gravity well. From the surface of the moon, the escape velocity is 2.38 km/s (7,808 ft/s), which is a lot faster than a bullet. Even on little Ceres, most bullets could not exceed escape velocity under normal circumstances. In an upcoming arc, a particular gun could only achieve escape velocity when fired eastward near the equator.

  And even if he did fall to the surface wouldn’t he be dead seconds after exit thru the window from the vacuum of space ?

How long can you hold your breath? Vacuum is deadly, but mostly it's the anoxia that kills you. You don't explode or anything.

  Not to mention that his body would have been frozen in the “44” seconds of “free fall”.  So the impact would leave a sizable crater and Norman would be smashed into a lot of small chunks ???

Vacuum is the perfect insulation. To lose heat, you have to radiate it away, primarily as infrared. Ain't gonna happen in 44 seconds. Norman would lose essentially zero heat during his fall. So "SPLAAAT!" would be the appropriate comic F/X.

Brugle on June 01, 2010, 10:59:15 am
  And even if he did fall to the surface wouldn’t he be dead seconds after exit thru the window from the vacuum of space ?

How long can you hold your breath? Vacuum is deadly, but mostly it's the anoxia that kills you. You don't explode or anything.

At least one SF story about surviving a short time in vacuum (out one air lock, in another) had the recommendation to try to breathe out (for those few seconds) to prevent damage (not necessarily explosion) from air pressure in the lungs.  Was that a bad recommendation?

I'm pretty sure that the recommendation to keep the eyes closed (to prevent the surface of the eyes from boiling and freezing) was a good one.

ZeissIkon on June 01, 2010, 05:08:57 pm
Well, okay, first, you can also lose heat in vacuum from evaporation (same way you lost most of your heat in Earth-normal conditions).  This was the principle behind the old SF standby, the skinsuit or skin tight suit: evaporation of sweat (and wasn't Norman pretty sweaty in that last frame before the window blew out?) cools the body; in fact, in vacuum, water can boil off the surface of a drop fast enough to freeze the remaining drop before it all evaporates.  Norman likely had a case of mild skin frostbite before he hit the regolith.

Second, "The Colors of Space" was probably the story Brugle refers to, though most of us had seen Dave Poole brave momentary vacuum exposure in the movie version of "2001: A Space Odyssey" long before the former story was written.  In fact, Normal was probably unconscious before he hit bottom (44 seconds is a long time in vacuum -- and holding your breath is not only inadvisable, it's impossible, your glottis isn't up to retaining around 100 MPa), but the other major problem he'd have had by that point (and  what would be racing simple anoxia for the honor of killing him) is a very, very bad case of gas emboli throughout his circulatory system -- effectively, an instant ischemic stroke brought on by fizzy blood.

SandySandfort on June 01, 2010, 05:21:31 pm
At least one SF story about surviving a short time in vacuum (out one air lock, in another) had the recommendation to try to breathe out (for those few seconds) to prevent damage (not necessarily explosion) from air pressure in the lungs.  Was that a bad recommendation?

I may be wrong, but that sounds crazy. Do you really want your lungs turned inside out and shoved out your mouth? (Okay, that may be a bit of an exaggeration, but a collapsed lung seems like a given unless you hold your breath in.)

I'm pretty sure that the recommendation to keep the eyes closed (to prevent the surface of the eyes from boiling and freezing) was a good one.

I read somewhere that constantly blinking your eyes keeps your peepers moist, but does not much increase the danger of boiling or freezing. Plus, of course, you get to see where you are going.

ZeissIkon on June 01, 2010, 07:30:16 pm
At least one SF story about surviving a short time in vacuum (out one air lock, in another) had the recommendation to try to breathe out (for those few seconds) to prevent damage (not necessarily explosion) from air pressure in the lungs.  Was that a bad recommendation?

I may be wrong, but that sounds crazy. Do you really want your lungs turned inside out and shoved out your mouth? (Okay, that may be a bit of an exaggeration, but a collapsed lung seems like a given unless you hold your breath in.)

I'm pretty sure that the recommendation to keep the eyes closed (to prevent the surface of the eyes from boiling and freezing) was a good one.

I read somewhere that constantly blinking your eyes keeps your peepers moist, but does not much increase the danger of boiling or freezing. Plus, of course, you get to see where you are going.

As I understand it, the major danger from trying to hold your breath is the same as if you were to stick a compressed air hose in your mouth: it takes only about 3 psi (20 MPa) to start bursting alveoli in large numbers -- large enough numbers to add up to a huge risk of an air embolism leading to stroke or death.  Fortunately, your glottis can only retain about 2/3 of that pressure (so a sneeze doesn't kill you -- usually -- if you try to contain it), and your epiglottis even less, so unless you clamp your mouth and nose shut (which is bad news for your eyes, see below), you won't do much damage that way.  I wonder about collapsing lungs; that would require there be some volume of fluid to compress the lungs, an unless you're hemorrhaging into your chest cavity, that fluid volume isn't available without some external pressure (for instance, pushing the abdominal organs up against the diaphragm).  Still, probably best would be to exhale until the pressure in the lungs is about the same as blood pressure (120 mm Hg for a healthy diastole is equivalent to almost 2.5 psi, around 17 MPa) -- which, as it happens, is about what the glottis is capable of retaining in any case.

As for blinking, the story I referenced above had the characters (and all space-going folks) hypnotically conditioned to reverse their usual blink pattern during a vacuum survival situation -- that is, flick the eyes open for a fraction of a second every second or two, moving by visual memory between "reverse blinks", so as to avoid doing sufficient damage to the eyeballs to survive as a blind man.  I don't know that any actual testing has been done on what's better, but if you need to see to survive, you might well prefer to survive with vision damage than to die trying to save your eyes.  FWIW, the cornea can actually freeze without major damage, as long as the fluid behind it (which is as salty as blood, so freezes at around -1.5º C) doesn't also freeze -- this is known from arctic/antarctic expeditions in which people actually have frostbitten their eyeballs.  At least you don't have to worry about your internal pressure blowing your eyeballs out of their sockets; your blood pressure (which is, effectively the internal pressure in your entire body) isn't enough to do that, by about a factor of four.

Honestly, based on what I've read, the human body is remarkably well designed to survive short exposures to vacuum -- the eardrums are probably the most vulnerable part, and a pair of ruptured tympani won't kill you.  Of course, that won't help you when you fall a mile to the lunar surface without benefit or either a pressure suit or a maneuvering unit capable of landing you softly...

Brugle on June 01, 2010, 08:02:36 pm
Second, "The Colors of Space" was probably the story Brugle refers to,
the story I referenced above had the characters (and all space-going folks) hypnotically conditioned to reverse their usual blink pattern during a vacuum survival situation
Well, I remember the people being "normal" humans, but my memory could be corrupted.  Also, I quickly skimmed The Colors of Space (at Project Gutenberg) and didn't find a bunch of people who were exposed to space for a short time.  Is there such a scene?

Thanks for describing some effects of vacuum on the human body.  Very interesting.

Added: maybe I have the wrong "The Colors of Space", since that story (by Bradley) was apparently published about 5 years before "2001: A Space Odyssey" was released.
« Last Edit: June 01, 2010, 08:08:19 pm by Brugle »

wdg3rd on June 01, 2010, 11:33:32 pm
Second, "The Colors of Space" was probably the story Brugle refers to,
the story I referenced above had the characters (and all space-going folks) hypnotically conditioned to reverse their usual blink pattern during a vacuum survival situation
Well, I remember the people being "normal" humans, but my memory could be corrupted.  Also, I quickly skimmed The Colors of Space (at Project Gutenberg) and didn't find a bunch of people who were exposed to space for a short time.  Is there such a scene?

Thanks for describing some effects of vacuum on the human body.  Very interesting.

Added: maybe I have the wrong "The Colors of Space", since that story (by Bradley) was apparently published about 5 years before "2001: A Space Odyssey" was released.

Clarke's story on the subject, "Take a Deep Breath" was published in 1957 when I was two years old.  MZB's story was rather later and definitely not related -- some consider it an offshoot of her Darkover series (taking place elsewhere in the Terran Imperium -- and as far as I know it's still under copyright and shouldn't be at Gutenberg).

If I'm going through vacuum (hopefully briefly) I'll exhale (and not clench my asshole -- a fart in a spacesuit isn't fun, but I'd rather not have my intestines explode) to avoid serious pressure on the inside.  The bit of air in the lungs is trivial (unless you wait until anoxia has already set in, in which case it's probably too late anyway).  Yeah, it's a whole-body hickey (I think that Clarke's story was republished under the alternate title (possibly in a Playboy Books anthology in the early 70s) because of that likely effect.  I know they did at least two collections of Clarke stories, and I know damned well that a number of stories there had major changes , both in title and text, from other published versions.  But I don't have those books anymore (as Poor Richard said once," Three Removes Equal One Fire", and I've moved a lot more than three times since my teens).

Yeah, Clarke may have been a major socialist (and perhaps a pedophile by some rumors), but he did write some damed fine stuff.  "A Meeting with Medusa" probably started me on my hobby of designing LTA transportation systems.

I know NASA did some tests with chimps who survived a couple of minutes in vacuum.  (They weren't allowed to test astronaut candidates to destruction, now it's illegal to test chimpanzees even halfway there).
Ward Griffiths        wdg3rd@aol.com

Men will never be free until the last king is strangled with the entrails of the last priest.  --  Denis Diderot

Brugle on June 02, 2010, 10:27:51 am
Clarke's story on the subject, "Take a Deep Breath" was published in 1957
I started reading SF (from my older sister's bookcase) a couple of years after that.  I'd guess that is the story I remember.

Rocketman on June 02, 2010, 02:14:55 pm
When the television show "Moonbase Alpha" was on there was a comic book based on it that showed the character played by Martin Landau in one of the "eagle" shuttles that had accidently struck a small nuclear mine put in place by a very small race who were the size of a human thumb.  It badly damaged the shuttle and created a hole big enough to suck Landau out of the ship.  He managed to find his helmet and put it in place before succumbing to lack of oxygen.  I always thought that if it were a matter of maybe six or seven seconds a person could survive in vacuum provided that a sun was close enough to provide warmth.

sams on June 02, 2010, 05:19:42 pm
If you shoot a 20 gauge slug out of a 12 gauge barrel...how fast does the slug exit the barrel?
Remember also, Norm managed to hold on for a bit, so assuming the air was partially depleted by the time he lost his grip, he'd have less velocity leaving that window.

And hey.  Asphyxiated, frozen to death.  Bludgeoned to death by his own fall.  Shattered into myriad pieces on impact.  The little tinpot would-be dictator/repeat rapist still died an unpleasant death.

Also, I thought the moon had 1/7th gravity.



Your assertion are quite good, but a little torture of the laws of phisics is no crime in the pursuit of artistic perfect ... think of star trek, star wars, fire fly, Smallville etc

Quote
And hey.  Asphyxiated, frozen to death.  Bludgeoned to death by his own fall.  Shattered into myriad pieces on impact.  The little tinpot would-be dictator/repeat rapist still died an unpleasant death.

you forgot roasted once the eclipse set out and direct sun light get him to 150 degrees in 5 sec ;D

ZeissIkon on June 02, 2010, 06:12:23 pm
Added: maybe I have the wrong "The Colors of Space", since that story (by Bradley) was apparently published about 5 years before "2001: A Space Odyssey" was released.

Sorry, I think the actual title was "All the Colors of Space" -- it was one of a series published in Analog in (IIRC) the 1980s, involving zero-point energy propulsion, degenerate matter or neutronium as a gravitational compensator for high acceleration (allowing constant boost travel within the Solar System at up to 100 G while passengers and crew experienced just the usual 1 G), and a couple ongoing characters (one of whom, in fine SF tradition, was a socially inept genius; the other was a corporate troubleshooter and the genius' keeper).  It's been a long time since I read the stories, I don't recall the author, and I don't know if they were ever collected.  Unfortunately, Google can't find the title for me, and Analog's online index is down for renovation, it says.

When the television show "Moonbase Alpha" was on there was a comic book based on it that showed the character played by Martin Landau in one of the "eagle" shuttles that had accidently struck a small nuclear mine put in place by a very small race who were the size of a human thumb.  It badly damaged the shuttle and created a hole big enough to suck Landau out of the ship.  He managed to find his helmet and put it in place before succumbing to lack of oxygen.  I always thought that if it were a matter of maybe six or seven seconds a person could survive in vacuum provided that a sun was close enough to provide warmth.

Go back a little further, there was a vacuum exposure scene in the British "UFO!" series -- nothing spectacular about it, as the decompression was gradual and the exposed character just lost consciousness for a few seconds before rescuers arrived.

Rocketman on June 03, 2010, 09:13:00 am
Made a slight mistake on my last post.  I believe that the name of the TV show was "Space 1999" and the location was moonbase alpha.  My bad.  ;D

wdg3rd on June 04, 2010, 01:27:10 pm

Sorry, I think the actual title was "All the Colors of Space" -- it was one of a series published in Analog in (IIRC) the 1980s, involving zero-point energy propulsion, degenerate matter or neutronium as a gravitational compensator for high acceleration (allowing constant boost travel within the Solar System at up to 100 G while passengers and crew experienced just the usual 1 G), and a couple ongoing characters (one of whom, in fine SF tradition, was a socially inept genius; the other was a corporate troubleshooter and the genius' keeper).  It's been a long time since I read the stories, I don't recall the author, and I don't know if they were ever collected.  Unfortunately, Google can't find the title for me, and Analog's online index is down for renovation, it says.


Charles Sheffield.  One of his McAndrew stories.

Ward Griffiths        wdg3rd@aol.com

Men will never be free until the last king is strangled with the entrails of the last priest.  --  Denis Diderot