• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Death in space

Outland, if I remember right, with Sean Connery. People more or less exploded.

I don't really understand why the water wouldn't start to boil. I can't believe there wouldn't be room for expansion of the blood to the point that some of the water vapor became gas, and then I would think it would be all over.
 
Michael Redman said:
Outland, if I remember right, with Sean Connery. People more or less exploded.

I don't really understand why the water wouldn't start to boil. I can't believe there wouldn't be room for expansion of the blood to the point that some of the water vapor became gas, and then I would think it would be all over.
Click to expand...

Because your circulatory system is remarkably good at maintaining pressure and repairing leaks. This is why you have this magical property called "blood pressure" and you don't bleed to death when you get a cut. If your blood pressure is maintained, your blood will not boil. ;)
 
A blood pressure of 120/80 mmHg is equivilent to 2.32/1.55 psi above ambient pressure. I wouldn't think that the vessels' ability to withstand normal blood pressure has any bearing on whether they can withstand boilding blood after a 14 psi drop in ambient pressure.
 
Michael Redman said:
A blood pressure of 120/80 mmHg is equivilent to 2.32/1.55 psi above ambient pressure. I wouldn't think that the vessels' ability to withstand normal blood pressure has any bearing on whether they can withstand boilding blood after a 14 psi drop in ambient pressure.
Click to expand...

This is getting tiresome.

1) It isn't a 14 PSI drop in pressure. If you're in a spacecraft, you're probably breathing pure oxygen at 3 to 4 PSI.

2) The Air Force put actual people into actual vacuums. Their blood didn't boil; their lungs didn't explode; their eyeballs didn't pop out. They even exposed them to explosive decompression, and those things didn't happen in those cases, either. Just which part of this is so terribly difficult to understand? It's been tried. It doesn't happen. We call this "reality." Whether you like it or not.
 
I was just speculating about the boiling blood. I mean, I looked up the correct vapor pressure, but other than that, I don't really know anything about it. If it was actually tried, then of course whatever happened is what happens.
 
In physics recently we were treated to the spectacle of a glass of water in a vacuum chamber. It wasn't the best vacuum ever, but I think the pressure got pretty low (not pressure gauge). The water did not boil, I noticed, but the dissolved oxygen and other gasses in the water did nucleate as bubbles along the sides of the glass. We never tested, but I'm pretty sure that just a little heat would have boiled the water easily. There was quite a bit of condensation on the inside of the vacuum chamber, so I imagine that if you were under a lot of solar radiation and in a vacuum, you might be in trouble.

I decided I could probably survive at least a little while in a vacuum, but that I probably wouldn't want to. I'm also fairly sure that I won't have to deal with this contingency in the near future. I suppose I'd have bigger things to worry about then.

I wonder if birds, thanks to their siginificantly different lung design would do better/worse in a vacuum.
 
neutrino_cannon said:
In physics recently we were treated to the spectacle of a glass of water in a vacuum chamber. It wasn't the best vacuum ever, but I think the pressure got pretty low (not pressure gauge). The water did not boil, I noticed, but the dissolved oxygen and other gasses in the water did nucleate as bubbles along the sides of the glass.
Click to expand...

In regards to blood, don't forget the property of boiling point elevation. Blood has other 'stuff' dissolved in it, therefore, it's boiling point will be higher than that of water.
 
Blood has other 'stuff' dissolved in it, therefore, it's boiling point will be higher than that of water.
Click to expand...
Don't you mean lower than water?
 
epepke said:
2) The Air Force put actual people into actual vacuums. Their blood didn't boil; their lungs didn't explode; their eyeballs didn't pop out. They even exposed them to explosive decompression, and those things didn't happen in those cases, either. Just which part of this is so terribly difficult to understand? It's been tried. It doesn't happen. We call this "reality." Whether you like it or not.
Click to expand...
I was not aware of that. I missed your previous post. Can you provide a link discussing air force tests on humans? I think that would be quite interesting.

Please forgive my ignorance, and the horrible offense it appears to have caused you.
 
I believe NASA stopped using pure oxygen atmospheres afterr the Apollo 1 fire.
 
Michael Redman said:
I was not aware of that. I missed your previous post. Can you provide a link discussing air force tests on humans? I think that would be quite interesting.

Please forgive my ignorance, and the horrible offense it appears to have caused you.
Click to expand...

This has me curious too. Reading the referenced post, as posted, makes me think those Air Force guys are real bastards!

Plus, (please don't call me names for asking this) wouldn't such exposure cause, at the very least, a body-wide hickey?

If not, why not?
 
The more stuff that's dissolved in water, the higher the boiling point
Click to expand...
OK thanks, so where did I get this idea that adding salt to water would make it boil faster? Old wive's tale?
 
Capsid said:
OK thanks, so where did I get this idea that adding salt to water would make it boil faster? Old wive's tale?
Click to expand...

Most people think that adding salt to water makes it boil faster. It actually raises the boiling point, thereby, making the food cook at a higher temperature, thereby cooking it faster. I think that's the logic, anway. My wife explained it to me once. I'll bet that Alton Brown has already given a better explaination for it on one of his episodes.

edited to add:

Ah, here we are: http://www.saltinstitute.org/29.html

"Salt added to water makes the water boil at a higher temperature, thus reducing cooking time. (It does not make the water boil faster.)"
 
You must log in or register to reply here.

Back
Top Bottom