Post reply

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.

Note: this post will not display until it's been approved by a moderator.

Name:
Email:
Subject:
Message icon:

shortcuts: hit alt+s to submit/post or alt+p to preview

Please read the rules before you post!


Topic Summary

Posted by: Sematary
« on: February 11, 2014, 01:17:40 AM »

Quote from: MarcAFK on February 11, 2014, 01:02:01 AM
Lets just imagine you had really good sunscreen on, or skin that absorbed all UV, and that you survived the vacuum, perhaps you have an air tank, I'm wondering how long you could survive from a heat perspective, another question would be what happens to your skin with long term exposure to vacuum. Judging from what I've seen from exposure to vacuum I imagine you might get burst blood vessels and internal bleeding. As a kid I had a tennis ball which had been cut in half, it made an extremely good suction cup which when applied to various areas of exposed skin for several minutes left a rather severe bruise, I recall reading somewhere that long term exposure to vacuum based sexual appliances causes injury, but I don't recall the exact details. I kinda imagine it might be similar to the damage caused by attempting to pop a pimple/blackhead/remove a spinter/tick by squeezing, eventually the pressure actually breaks the skin causing bleeding.
I don't know if that has been studied to be honest. Burst capillaries would happen, they happen in the eyes pretty quickly. Anything else doesn't seem to have been studied because those two suppositions are huge/unrealistic.
Posted by: MarcAFK
« on: February 11, 2014, 01:02:01 AM »

Lets just imagine you had really good sunscreen on, or skin that absorbed all UV, and that you survived the vacuum, perhaps you have an air tank, I'm wondering how long you could survive from a heat perspective, another question would be what happens to your skin with long term exposure to vacuum. Judging from what I've seen from exposure to vacuum I imagine you might get burst blood vessels and internal bleeding. As a kid I had a tennis ball which had been cut in half, it made an extremely good suction cup which when applied to various areas of exposed skin for several minutes left a rather severe bruise, I recall reading somewhere that long term exposure to vacuum based sexual appliances causes injury, but I don't recall the exact details. I kinda imagine it might be similar to the damage caused by attempting to pop a pimple/blackhead/remove a spinter/tick by squeezing, eventually the pressure actually breaks the skin causing bleeding.
Posted by: Sematary
« on: February 11, 2014, 12:45:24 AM »

Quote from: Rod-Serling on February 11, 2014, 12:18:11 AM
The biggest problem with life developing in space, in my humble uneducated opinion, would be the lack of particle interaction.

Photosynthesis as we know it requires Carbon Dioxide and water, both of which are quite rare in space. Might there be such a bacteria on the surface of a comet? Sure, I would buy that, but in the raw vacuum of space it's hard to get the right amount of the right materials together in order for such a organism to form, or reproduce.

But I'm no scientist.
Comets are probably the most likely place for life in space to develop, several terrestrial species have been proven to be able to live for short periods of time, usually months, in comet like conditions including hard vacuum. Any life would have to be in system which is very dense, for space at least, and as I understand the density of particles in system there are areas that could support life but its such an incredibly remote possibility that its not worth looking into right now.

Quote from: MarcAFK on February 11, 2014, 12:31:09 AM
There was a comment on that video about freezing in space, I had to reply that personally I thought not only would you not fereze from the lack of conduction through your skin, but you might even overheat from your own waste heat, I remember in winter getting very hot as a result of too much insulation from blankets, I was wondering what percentage of waste body heat is lost as radiation and how much is lost through contact with air, I'm pretty sure conduction is the most important one.
Also I would assume that if you didn't die instantly if you were in the sun you would actually cook since you would get almost 1400 watts per square meter which is basically half as much as a kettle, Rough estimate would be since a kettle takes 2 minute to boil half a litre, It might take 10 hours to bring your body to 100 degrees, how does that compare to the heat that would be lost through convection?
From watching several videos, including ones put out by NASA, as I understand it you live rather fine for the first 10-30 seconds and then pass out and die 2-3 minutes later. Never heard anything about overheating. If you are in the sun you get the worst imaginable sunburn. Its not IR that you have to worry about its the UV which is so much harsher than even the highest parts of Earth.
Posted by: MarcAFK
« on: February 11, 2014, 12:31:09 AM »

There was a comment on that video about freezing in space, I had to reply that personally I thought not only would you not fereze from the lack of conduction through your skin, but you might even overheat from your own waste heat, I remember in winter getting very hot as a result of too much insulation from blankets, I was wondering what percentage of waste body heat is lost as radiation and how much is lost through contact with air, I'm pretty sure conduction is the most important one.
Also I would assume that if you didn't die instantly if you were in the sun you would actually cook since you would get almost 1400 watts per square meter which is basically half as much as a kettle, Rough estimate would be since a kettle takes 2 minute to boil half a litre, It might take 10 hours to bring your body to 100 degrees, how does that compare to the heat that would be lost through convection?
Posted by: Rod-Serling
« on: February 11, 2014, 12:18:11 AM »

The biggest problem with life developing in space, in my humble uneducated opinion, would be the lack of particle interaction.

Photosynthesis as we know it requires Carbon Dioxide and water, both of which are quite rare in space. Might there be such a bacteria on the surface of a comet? Sure, I would buy that, but in the raw vacuum of space it's hard to get the right amount of the right materials together in order for such a organism to form, or reproduce.

But I'm no scientist.
Posted by: Sematary
« on: February 10, 2014, 07:34:53 PM »

Quote from: Theodidactus on February 10, 2014, 07:27:37 PM
Crichton had the right idea: if there's life IN outer space, it's most likely extraordinarily small.
I agree with that completely. They would also most likely be close to cyanobacteria if they are native to space. Anaerobic photosynthesizers.
Posted by: Theodidactus
« on: February 10, 2014, 07:27:37 PM »

Crichton had the right idea: if there's life IN outer space, it's most likely extraordinarily small.
Posted by: Rich.h
« on: February 10, 2014, 02:51:51 PM »

Nice topic with some enlightening information. One thing that became more and more apparent in this thread is that space really isn't all that hostile to life. Now I don't mean to suggest it is all happy up there but considering some of the conditions we have here on earth such as inside a volcano etc then the vacuum of space seems almost balmy with the correct physiological adaptations.

Taking into account the sheer number of creatures that actively thrive down in the deep oceans at geothermal vents, I am somewhat hopeful there could be some form of life that could survive the rigors of space too. Star trek space squids anyone?
Posted by: Triato
« on: February 10, 2014, 10:36:16 AM »

http://www.youtube.com/watch?v=pm6df_SExVw There is also another explanation in the vsauce channel. They made a pair of mistakes that they latter corrected if I remember right.
Posted by: Sloshmonger
« on: December 20, 2013, 01:15:40 PM »

Never get off the boat!
Posted by: Bremen
« on: December 07, 2013, 11:30:39 PM »

For what it's worth, the freezing from vacuum exposure isn't because space is cold (while technically it is cold, there's so little there it can't steal much heat) but because liquids like sweat/spit/blood/whatever the name is for liquid in your eyes and such flash boil causing rapid cooling. It would be a very bad thing, and probably cause all sorts of harm, but I can't imagine it would kill you before all the other more immediate problems did.
Posted by: Theodidactus
« on: December 01, 2013, 11:05:57 PM »

Quote from: Dvorhagen on December 01, 2013, 11:30:46 AM
My understanding is that the main hazard of being exposed to space is suffocation. 

It depends on what you mean by "suffocation". You can't actually hold your breath out there, at least, I don't think so. As I understand it, Your blood will rapidly lose its oxygen even if you're tightly closing your throat.

Quote

The point is just that anoxia would kill you long before either cold or vacuum would.


I think so. Just very quickly, less than a minute.

if you're interested, I've posted a link to the pubmed citaiton of the primary article I used in my own research on this. I can post a .pdf of the study when I get back to my home computer.

Posted by: Geoffroypi
« on: December 01, 2013, 03:16:13 PM »

 ;D





Conclusion :

Bad guys explode in pain .
Good guys freeze instantly .


If i remember well, nasa website provides a good and reliable source of  informations about that subject, in case Maltay (very good) explanation isn't enough .
Posted by: Maltay
« on: December 01, 2013, 02:56:04 PM »

Please keep in mind you really only need to worry about gas.  The human body is primarily based on water or liquids close to water.  Water at 1 ATM is about as uncompressed as water gets without a phase change.  This is why I can SCUBA dive to 99 feet at 4 ATM and only need to worry about gas equalization through my eustachian tubes.  Going from 1 to 0 ATM very quickly would probably cause more than just a lung embolism.  Any gas in cavities, like in your sinuses, would expand.  Some spots, like your sinuses, are not so bad as you can exhale quickly and hope for the best.  Other spots, like tiny cavities of air in your tissues and joints, are potentially a big issue.  In general, expect a slightly swollen appearance.  However, also expect embolisms scattered throughout your body where your tissue tore from escaping gas.  Think of these more like internal injuries than anything else.  In general, your skin can take more of a beating than the tissues separating one organ from another.  These injuries may not be evident if just looking at the body, but the person would probably have had internal hemorrhaging.
Posted by: Dvorhagen
« on: December 01, 2013, 02:48:52 PM »

There would certainly be inflammation, swelling, and burst blood vessels, and you certainly wouldn't want to be exposed to space for very long.  I'm just saying it wouldn't be nearly as bad as movies, etc. , depict it.  More on the order of bleeding eardrums, bloodshot eyes, and reddened skin than of bursting eyeballs and instant embolisms. 

The point is just that anoxia would kill you long before either cold or vacuum would.