ignore poll please ... couldn't find the post button.

What a n00b!
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What an utter n00b!
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Total Members Voted: 1

BMeph on August 24, 2010, 09:38:30 am

If suitable zippers could be put on the suit in sufficient quantity without compromising its airtight seal, though, taking it off would become trivial.

Ah. Add belts to the suit. Belts that are tightened with turnbuckles, in order to achieve the necessary level of tension in the suit fabric for it to apply the needed pressure - thereby achieving the design shape of the suit, at which point the zippers could be closed.
While I was working on Kwajalein as an ALSE (Aviation Life Support Equipment) tech., one of the ballistic missile tests shot at us used an RB-57 as a sensor platform. The crew of said aircraft had to wear, in effect, space suits because of the altitude at which they flew. Since their support team used my shop to do their maintenance, I got 'checked out' on doing a spacesuit pre-flight inspection. (Suits were made by David Clark, BTW.) The suits were sized using laces and sealed with zippers.

Dealing with the LOX was a bit of a pain in the rear.

I'm hoping that's just a turn of phrase, and not a literal reference to the...er, access port.

dough560 on August 28, 2010, 02:51:18 am
Many readers don't know the difference between fiction based on the hard sciences or fantasy.  Those who aren't sure which is which, are too lazy to think their way through.

J Thomas on August 28, 2010, 08:22:09 am
Many readers don't know the difference between fiction based on the hard sciences or fantasy.  Those who aren't sure which is which, are too lazy to think their way through.

The trouble is that the distinction has gotten way, way blurred.

Hard science fiction from the 1930's is not hard science fiction any more.
Most hard science fiction from the 1950's is not hard science fiction any more.
A whole lot of hard science fiction from the 1970's is not hard science fiction any more.

What's hard science fiction now? Should all the stories be limited to very slow travel in one solar system, plus possibly ruinously-expensive slow generation ships headed to nearby stars? Or will we say "wormholes" and use that to make it hard science fiction? Or throw in something about FTL drives?

Quantum mechanics does not make intuitive sense. So physics no longer makes intuitive sense. If somebody says something that makes no sense, it could be true. Vice versa, when Townes first got the idea for the maser, various prestigious physicists told him it was impossible because of quantum mechanics. After he did it, they figured out their mistakes and saw that it fit quantum mechanics after all.

I found that various things in probability theory are kind of unintuitive. It's easy to make some simple slip and think you're measuring one thing when really you're measuring something else. The Monty Hall problem is one example -- you get different results depending on minor difference in the way the problem is stated, and usually those details are left unstated. And quantum mechanics is heavily polluted with probabilities. So, does Bell's theorem have the unintuitive results that people want to say it does? Maybe. Maybe not. You can use it in a story and in ten years it might be like you used phlogiston or copy-choice.

Or look at the BlackLight Power guys. Revolutionary stuff if it's right. But they look like scam artists. How would you find out if it's right? Experimental results, which have not yet been done by anybody who isn't in their employ and who isn't being sued for saying it doesn't work. Is it hard science fiction if you use their results?

Hard science fiction is mostly a social phenomenon. It's science fiction that fits the preconceptions of guys who got an engineering degree 20 to 40 years ago.

terry_freeman on August 28, 2010, 10:01:51 am
Hard SF need not be 100% reliable science - in fact, it often does have elements of speculation, such as travel through wormholes or other means of FTL travel. However, it should not permitted to degenerate to the level of "anything can happen, it's all magic and incantations" - which characterizes much of the thud and blunder school.

Once in a while, writers are surprised to discover their speculations becoming reality. Asimov wrote The Last Question in 1956, which predicted the miniaturization of computers - over very long time scales. Heinlein wrote about the use of vast libraries of computerized information, which must seem familiar to any user of google, wolfram alpha and wikipedia today.

http://www.wolframalpha.com/input/?i=price+of+gold

SandySandfort on August 28, 2010, 05:57:24 pm
Hate to interrupt Star Wars: The Troll Wars, with information about the original topic, but this info is very cool, very authoritative. These two sites discuss the effects of explosive decompression:

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

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

KBCraig on August 30, 2010, 01:25:00 am
Thanks for the links, Sandy. The data on time to unconsciousness seems counterintuitive, since the blood is still oxygenated and flowing, at least unless or until something interferes with the flow, or the oxygen in the blood supply is depleted.

The data seems perfectly in line with what we teach about responding to choke holds, though: once the blood supply to the brain is blocked, you have about 10 seconds to restore it, or you're toast.

Grashtel on September 01, 2010, 03:10:58 am
Thanks for the links, Sandy. The data on time to unconsciousness seems counterintuitive, since the blood is still oxygenated and flowing, at least unless or until something interferes with the flow, or the oxygen in the blood supply is depleted.
The thing is that the blood going to the brain is no longer oxygenated .  Once the lungs are "filled" with vacuum they pull the oxygen out of the blood passing through them (passive gas exchange works equally well either way) which then goes straight to the brain.

Sio on September 01, 2010, 09:24:13 am
He knows what pocket the comm is in, right?  Where the pocket opens?  Do they have patch kits for their suits, to repair minor damage?

Shut down suit pressure, or turn it way low.  Ignore the warning hooters.  Cut a small incision right over the pocket seal-rip or whatever.  Quickly fish out the comm, while the the other brother stands with a patch hovering ready over the cut.  Once the comm is out, slap on the patch.  Apply a bigger one over THAT patch.  Wait the necessary couple of minutes for the patch to cure, living on what's left of your suit air (it all wouldn't have gone out that little cut in that short time, just like a bullet hole in a plane doesn't depressurize the whole craft, that's a myth).  Then increase it slowly while watching the patch.  If it leaks, slap on more sealant.  If not, raise pressure to normal, connect your comm to your suit, and start yelling for help.  I doubt you'd die or suffer major injury from a small incision, that's why they have patch kits.  Otherwise, a small bit of damage would be instant death, and they wouldn't bother to have them, they'd be pointless.  I think, worst case, he'd have a hickey right under the incision, but I doubt he'd have that, since there'd be fabric between vacuum and the skin.

J Thomas on September 01, 2010, 02:43:36 pm
Quickly fish out the comm, while the the other brother stands with a patch hovering ready over the cut.  Once the comm is out, slap on the patch.

I wondered about this approach. What do you get once you have the comm out in vacuum?

If you have an arrangement to do morse code with it then you can send a signal with your fingers. If you can type on the comm with a spacesuit on, then you can send text messages. If you need to talk into a microphone then getting the comm out of the suit is only half the problem. You have to put it back inside the helmet....

Sio on September 02, 2010, 09:32:33 am
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You have to put it back inside the helmet....

You don't have to get it into the helmet unless it's a voice comm that can only be used with a microphone.  Silly arrangement for a comm to be used in space, where you spend a large percentage of your time in vacuum, where your voice is useless, and you can't get anything near your mouth.  It'd be a poor design, something only a groundhog would carry.   Besides, this is a tanglenet comm, something that does voice, video, and computer net communications. It's more of a smartphone/iPad/modem than a walkie-talkie, if I get the concept right, and as such, it'd have multiple interface methods.  One such would be to plug it into different inputs, such as a video source, alternate microphones, comms, or computers to interface them to the Tanglenet.  It'd likely have something like a USB connector on it to do this, something fairly standardized.  Being able to plug the tanglenet comm into their suit comm from the outside would only make logical sense -- it would be the engineering feature that would make it usable to people who spend significant time in vacuum.

These people, unlike the bureaucrats from Earth, do not strike me as being illogical or stupid about space engineering practices.  And you don't get many second chances with the latter, so the dumb ones would get weeded out, and you'd end up with the smart engineering practices.  Mind you, that doesn't preclude being lazy or lacking foresight and simply forgetting to put the gadget in an outside suit pocket, or having the extra gold grams to buy a suit that has it as a built-in feature in the first place, or having it as a built in occipital implant system that you can't ever be without.  In those cases, hindsight is 20/20, and if you live long enough, you correct them.

Even my Earthly tri-band amateur radio handie-talkie has the necessary jacks for the mike and speaker to be routed elsewhere.  It could be plugged into a spacesuit without much trouble, if one had the necessary cable, and the suit had a matching jack.  For that matter, even my Android cell phone could be routed to a spacesuit through a remote cable.  What do you think a headset jack is FOR?  I'll grant, though, that neither one is space-hardened, though similar handie-talkies ARE used on the ISS on a regular basis, they typically are not exposed to vacuum and probably would not survive the experience.

J Thomas on September 02, 2010, 09:56:34 am
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You have to put it back inside the helmet....

You don't have to get it into the helmet unless it's a voice comm that can only be used with a microphone.

Sure, and there's no particular reason to put it inside a spacesuit where it isn't available. Or better to have a jack there too, so you can use it while it's inside your suit. And wouldn't it make sense to have a spacesuit design that lets you pull your arm out of the sleeve and scratch your back? Then you could do anything with stuff that's inside the suit that you can do by feel.

If it's useful in vacuum then maybe it's a mistake to make it inaccessible in the first place. I guess it could go either way.

Oneil on September 04, 2010, 03:57:48 pm
It looks obvious opening a suit was a bad idea, low pressure or not, re-patch kit close at hand and luck on the brothers side.  Fact is, Ernie would have to loose all pressure in the contained atmosphere of the closed circuit re-breather system.  I didn't see a huge backpack PLSS hanging off of them with extra Liquid Oxygen to make up lost volume repressurizing a suit and still expect to have four more hours duration to await rescue.  So Ernie would be sacrificing himself to save Bert, even if help could be called to fly immediately.

And it looks like Bert answered the question on how they could talk thru the comm unit had they had gotten it out of the suit on page 513.

More fun on the survival without suit debate.. 
http://en.wikipedia.org/wiki/Space_suit#Exposure_to_space_without_a_spacesuit



KBCraig on September 07, 2010, 03:15:37 am
Thanks for the links, Sandy. The data on time to unconsciousness seems counterintuitive, since the blood is still oxygenated and flowing, at least unless or until something interferes with the flow, or the oxygen in the blood supply is depleted.
The thing is that the blood going to the brain is no longer oxygenated .  Once the lungs are "filled" with vacuum they pull the oxygen out of the blood passing through them (passive gas exchange works equally well either way) which then goes straight to the brain.

Excellent, and logical, explanation. Thank you.

 

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