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Outer Space has a Smell
repapetilto writes "ISS Science Officer Don Pettit reports in his journal that outer space gives off a smell best described as "a rather pleasant sweet metallic sensation." Kind of odd considering smell is supposed to be due to volatilized chemical compounds."
Are you sure? I think this calls for an empirical test. Stick your head out the window and check.
I knew it!
http://www.gotfuturama.com/Information/Encyc-21-SmellOScope/
No, I think he means explode. You cant implode if there's negative outside pressure.
No explosions, according to Cecil: http://www.straightdope.com/classics/a3_147.html
You'd even have a few seconds of useful consciousness to take a whiff and stick your head back in!
While it's intellectually fanciful to believe this is the "smell of outer space", what this guy is smelling is the odor of the compressed air used to re-pressurize the airlock, or more exactly, the smell of the inside of the metalic containers and pumps for the storage of the compressed air which the air picked up when contained under pressure before being introduced into the airlock. Take a whiff of compressed air from an air compressor or air tank... hmm, smells like space (apparently).
Ozone, to me, has a distinctly un-sweet smell. I mean, stick your head over a photo-copier going at full speed and you get ozone. I can't stand the stuff for any length of time, really.
I also arc-weld, and do all sorts of other welding, and I think the sweet smell you noticed is much more likely vaporization of the flux, filler rod, and base material, surface contaminants (or any combination of the above) than it is to be of ozone, because those are produced in much higher quantities than ozone, and here's why: One of the main purposes the flux on the rod serves is to banish oxygen and other atmospheric gasses from the arc area when it vaporizes, creating a gaseous shield. If you were getting enough oxygen into the arc to produce a large quantity of ozone, something was way, way, WAY wrong, because it's also letting a huge amount of nitrogen and CO2 into the mix, and your welds would be so brittle it would not be funny.
From my understanding, ozone is produced while SMAW welding, but only in peripheral amounts, and as I understand it, the chief cause of this is the high intensity ultraviolet light busting up the oxygen molecules the surrounding atmosphere. Of course, if anyone knows more about this, I'm willing to be enlightened.
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There's no such thing as negative pressure, just like there's no such thing as negative temperature or volume either...
It's an operational definition referring to the relationship between the relative pressures of a system and its surroundings (usually atmospheric pressure). Never heard of negative volume.