[X] My Assistant

[Guest_BruceMoomaw_*]

Let's not forget that you'll come down with one hell of a case of hypothermia, given that the average surface temperature on Mars is -56 deg C -- and that you'll also come down with one hell of a case of sunburn even given Mars' greater distance from the Sun, since it has no ozone layer. Fun all around. Clearly Martian Streaking will be one of the major sports of the future Solar System-wide civilization.

[Rem31]

How long takes it before i die ,when i step on Mars without a pressuresuit? Is it painfull? And what about bloodboiling? I think that the blood in the body is going to boil when stepped (unprotected) on Mars. Can you explain this?

[Bob Shaw]

Let's not forget that you'll come down with one hell of a case of hypothermia, given that the average surface temperature on Mars is -56 deg C -- and that you'll also come down with one hell of a case of sunburn even given Mars' greater distance from the Sun, since it has no ozone layer. Fun all around. Clearly Martian Streaking will be one of the major sports of the future Solar System-wide civilization.

Bruce:

No, hypothermia won't be a problem - look at the fun and games that silly boys get up to at the south pole on Earth. You're talking about a few seconds of exposure in an environment where heat transfer is all about radiation (no wind to chill you) and, in any case, hypothermia is all about core body temperatures!

As for the UV... ...would 30 seconds worth of exposure burn you, especially if you'd splashed factor 20 sun blocker all over you?

I'd be more concerned about an allergic reaction to Martian dust, to be honest!

I *do* like the idea of Martian streaking, though. Or Lunar Streaking. Sorta puts a whole new light on how the unmanned spaceflight community should respond to the triumphal opening (by President-for-Life Dubya IV) of the 'Neil 'n' Buzz' theme park in 2069...

Oh, I'm gonna have nightmares now...

Bob Shaw

[Guest_BruceMoomaw_*]

How long takes it before i die ,when i step on Mars without a pressuresuit? Is it painfull? And what about bloodboiling? I think that the blood in the body is going to boil when stepped (unprotected) on Mars. Can you explain this?

No, your blood won't boil -- Arthur C. Clarke laid that cliche to rest in a story called "Take A Deep Breath" all the way back in the mid-1950s (which was later used as the basis for David Bowman's spacesuit-less return to his ship's airlock in "2001"). And as early as 1964, the Air Force did some vacuum chamber experiments on chimps (naturally) establishing that they could survive as long as 1-2 minutes in a vacuum without serious brain damage. (No word on how many chimps they killed or maimed while learning this.) But, while your blood certainly won't boil, it is fatal after a very short time -- and I imagine it's pretty painful.

Bruce:


I *do* like the idea of Martian streaking, though. Or Lunar Streaking. Sorta puts a whole new light on how the unmanned spaceflight community should respond to the triumphal opening (by President-for-Life Dubya IV) of the 'Neil 'n' Buzz' theme park in 2069...

Oh, I'm gonna have nightmares now...

Bob Shaw

Yes, particularly if I'm in them.

[Rem31]

Bruce:

No, hypothermia won't be a problem - look at the fun and games that silly boys get up to at the south pole on Earth. You're talking about a few seconds of exposure in an environment where heat transfer is all about radiation (no wind to chill you) and, in any case, hypothermia is all about core body temperatures!

As for the UV... ...would 30 seconds worth of exposure burn you, especially if you'd splashed factor 20 sun blocker all over you?

I'd be more concerned about an allergic reaction to Martian dust, to be honest!

I *do* like the idea of Martian streaking, though. Or Lunar Streaking. Sorta puts a whole new light on how the unmanned spaceflight community should respond to the triumphal opening (by President-for-Life Dubya IV) of the 'Neil 'n' Buzz' theme park in 2069...

Oh, I'm gonna have nightmares now...

Bob Shaw

But why are the apollo astronauts on the Moon not Sunburned? Strange that you get Sunburned on Mars in 30 seconds ,but on the Moon the astronauts where not getting Sunburned. Can you explain this?

[Bob Shaw]

But why are the apollo astronauts on the Moon not Sunburned? Strange that you get Sunburned on Mars in 30 seconds ,but on the Moon the astronauts where not getting Sunburned. Can you explain this?

Bruce and I have been discussing the prospects for (brief) Martian surface activity *without* spacesuits. He went so far as to bring up the subject of doing it without underwear, which got me started on sun cream.

The Apollo guys had underwear, as well as those big white things, with the helmets.

Bob Shaw

[Rem31]

No, your blood won't boil -- Arthur C. Clarke laid that cliche to rest in a story called "Take A Deep Breath" all the way back in the mid-1950s (which was later used as the basis for David Bowman's spacesuit-less return to his ship's airlock in "2001"). And as early as 1964, the Air Force did some vacuum chamber experiments on chimps (naturally) establishing that they could survive as long as 1-2 minutes in a vacuum without serious brain damage. (No word on how many chimps they killed or maimed while learning this.) But, while your blood certainly won't boil, it is fatal after a very short time -- and I imagine it's pretty painful.
Yes, particularly if I'm in them.

Why is it that your blood is not going to boil? Water is boiling too by the low pressure on Mars?

[Bob Shaw]

Why is it that your blood is not going to boil? Water is boiling too by the low pressure on Mars?

Because your blood is inside your body. Water will certainly evaporate from exposed skin, and any moist parts of the human body will tend to dry up, but in the short term there's more than enough water inside you to replace any that's lost at the surface.

People just don't go POP! when exposed to zero pressure, though they certainly don't survive for very long. They don't die at once, though, which gives rise to all sorts of fun and games (in theory).

Bob Shaw

[ljk4-1]

No, your blood won't boil -- Arthur C. Clarke laid that cliche to rest in a story called "Take A Deep Breath" all the way back in the mid-1950s (which was later used as the basis for David Bowman's spacesuit-less return to his ship's airlock in "2001"). And as early as 1964, the Air Force did some vacuum chamber experiments on chimps (naturally) establishing that they could survive as long as 1-2 minutes in a vacuum without serious brain damage. (No word on how many chimps they killed or maimed while learning this.) But, while your blood certainly won't boil, it is fatal after a very short time -- and I imagine it's pretty painful.
Yes, particularly if I'm in them.

Speaking of Mr. Clarke, he also wrote a story not too long ago about an
actual running race on the Moon. The main character wore a skin-tight
suit so that he could run faster.

Knowing how ACC tries to be as scientificially and technically accurate as
possible, does anyone who has the story handy have the details on how it
was made and how it kept the occupant pressurized? Thanks.

[Guest_BruceMoomaw_*]

Why is it that your blood is not going to boil? Water is boiling too by the low pressure on Mars?

Actually, water does NOT boil dramatically on Mars -- in fact, Mars' air pressure, low though it is, is very close to the level at which water CAN remain stable in liquid form on the surface. The University of Arkansas' Derek Sears, in fact, has been running some experiments recently to find out just how fast it WOULD evaporate on Mars, and has found that it evaporates at a rate as low as just a few millimeters per minute -- and slower than that if it's briny. (Another study has located a few low-altitude parts of Mars' surface on which water can actually stay liquid on Mars' surface for weeks at a time, before seasonal temperature changes make it either freeze or evaporate.)

The fact that Mars' air pressure is so close to the so-called "triple point" at which liquid water can exist may not be coincidence. One theory suggests that, just as Earth has a natural "carbonate thermostat" process that tends to keep its surface temperature in the range at which liquid water can exist, Mars may have a natural "carbonate air pressure regulator" -- that is, if its remaining low-intensity volcanoes belch out enough new CO2 to raise its air pressure to the point at which liquid water can exist, that liquid water tends to make some of the CO2 react with subsurface minerals and turn into carbonates, lowering the air pressure back to the threshold level again until more CO2 leaks out of the volcanoes. This theory, however, is still uncertain -- it may really BE coincidence.

And while water really does boil in the lunar vacuum, it's been pointed out -- by Arthur C. Clarke and others -- that the human body's skin and internal mucous membranes are really a pretty good pressure seal; internal gas leaks out of the human body fairly slowly even in a vacuum. Thus a vacuum will knock you unconscious in a few seconds -- and kill you in a minute or so -- but the internal pressure will never leak out of your body fast enough for the water in your blood to actually boil.

[Guest_BruceMoomaw_*]

Derek Sears' recent findings on the rate of liquid-water evaporation on Mars can be found at
http://www.lpi.usra.edu/meetings/lpsc2004/pdf/2112.pdf
http://www.lpi.usra.edu/meetings/lpsc2004/pdf/2159.pdf

I was wrong in saying that he reported evaporation rates of "a few millimeters per minute" -- it was actually just 1-2 mm PER HOUR. As I say, Mars is teetering on the very brink of having air pressure high enough for liquid water to exist stably there at the right temperature -- and, according to Robert Haberle, there are a few low-altitude places where seasonal temperature conditions do allow it to exist for weeks at a time: http://www.agu.org/pubs/crossref/2001/2000JE001360.shtml

[dvandorn]

I'd be more concerned about an allergic reaction to Martian dust, to be honest!

With all of those powerful oxidants (perhaps peroxides) so ubiquitous in Martian soils, I'm wondering what will happen the first time some of that dust hits the mucous membranes of a human being's nose and mouth.

At any rate, with all those sulphates around, the dust will likely stink to high heaven. If you want to colonize Mars, you better be able to get used to the smell of rotten eggs...

-the other Doug

[Bob Shaw]

I think a lot of the fluff around about water boiling away on the surface of Mars, or people's blood boiling if exposed to zero pressure, goes back to two things: bad early science-fiction, and that photograph (taken at Holloman AFB?) of the guy in the pressure suit in the evacuated chamber, holding a beaker of water which is furiously boiling. Right or wrong, those are the cultural memes which have infected us!

Bob Shaw

[paxdan]

Speaking of Mr. Clarke, he also wrote a story not too long ago about an
actual running race on the Moon. The main character wore a skin-tight
suit so that he could run faster.

Knowing how ACC tries to be as scientificially and technically accurate as
possible, does anyone who has the story handy have the details on how it
was made and how it kept the occupant pressurized? Thanks.

The story was "the hammer of god" and the character was 'Robert Singh'

it is a skin suit with a bubble helmet designed only for use at night... from p46.

'sheathed in two body-tight garments - one active, one passive. the inner one made of cotton, enclosed him from neck to ankle, and carried a closely packed network of narrow, porous tubes, to carry away perspiration and excess heat. Over that was the tough but extremely flexiable protective outer suit, made of a rubber like material, and fastened by a ring-seal to a helmet."

he gets frost bitten feet and is beaten at the last by Robert Steel (a robot).

Don't forget that the ultimate culmination of Kim Steanley Robinson's Mars Terraform epic -- after "Blue Mars" -- is the collection of short stories that might be called "White Mars", in which the process goes wrong and refreezes the planet (albeit with a thick atmosphere this time). At the end of that book, they're still trying to figure out how to straighten out the mess again.

The collection of short stories by KSR is called 'The Martians'. The culmination of that is a short called 'Purple Mars' in which the terraforming has been successfull.

'White Mars' was written by Brian Aldiss in collabaration with Roger Penrose and was very much a retort to KSR's mega terraforming.


Gregory Benford's "The Matian Race" contains a section where a character runs from a ruptured greenhouse to a Hab in Martian conditions. It was a highlight of the book.

[mcaplinger]

The collection of short stories by KSR is called 'The Martians'.

It's also not necessarily connected to the Mars trilogy. The novella "Green Mars" which is collected in THE MARTIANS is in something of an alternate universe from that of the trilogy, according to KSR.