When I first heard of sulfur hexafluoride I thought it had to be kind of nasty - it is a sulfur (VI) compound with a bunch of halogens attached (it looks if you added some water, you'd end up with dangerous HF and H2SO4!). However, like so many fluorous compounds, it is surprisingly lackadaisical; the stuff is a nontoxic, inert rock (the related SF5Cl, S2F10, and SF4 are all nasties and will totally throw some sulfrous-fluorous death your way).
What's more important, though, is that it's really dense. Plus - not only is it safe, it's safe enough to breathe! And if you breathe it you sound like a kid playing with a voice changer. Even Leno agrees!
- Log in to post comments
Breathing heavy gas is extraordinarly dangerous. If you get a good lungful it settles in your alveoli and you drown unless somebody turns you upside down. RSF5 are marvelous oxidants for aluminum and magnesium powders. Even dispersed teflon affords a party.
SF6 is a Greenhouse gas. As with all things Enviro-whiner, ignore that. Safe electrical transformers today are much more valuable than a tenebrous 100 years hence. Wouldn't we all be fools if Enviro-privations were...
Asteroid 99942 Apophis (2004 MN4) is 320 meters in diameter, masses 4.6x10^10 kg, and enjoys a 323.587 day solar orbit. It buzzes Earth threatening 1480 megatons from 12.59 km/sec (mv^2)/2 impact. On 13 Friday 2029 Apophis will pass within projected 22,500 miles of the surface. The next snuggle is 13 Friday 2036 and that cannot be calculated from extant data.
It's not as complex a molecule as sulfur hexafluoride, but plain old carbon dioxide will affect the pitch of sounds passing through it. I'm a trumpet player, and I often enjoy a beer or four while performing. On rare occasions, I find myself burping just as I play a note. When that happens, my pitch drops anywhere from a quarter tone (50 cents) to a half tone (100 cents).
I told my non-wind-instrument playing cohort about this, and they didn't believe me. Soon enough, I burped in midmelody, and after the tune, I said, "Did you hear that place where I suddenly went a half-step flat and then gradually came back up to pitch?"
"Yeah, what was that?"
"Carbon dioxide! I burped."
"Really? I thought you were playing the blues."
http://yarchive.net/med/helium_breathe.html
Probably not that dire.
But yeah, don't try it at home. Even if Wal-Mart is running a "lead balloon" special on SF6.
I understand that Wal-Mart is running a yellow-light special on Na vapor for the whole month!
Mmm... Smells like .
Fill a balloon with SF6, and oxygen will diffuse into the balloon more easily than SF6 will diffuse out. The balloon inflates and, eventually, explodes.
I just can't decompartmentalize my mind like that - inject the stuff into a vacuum chamber, ignite a plasma, and you can etch silicon, quartz (SiO2) and a few metals with it. Having done that myself a couple of times I tend to unconsciously place it among the nasty acid stuff, and be overly cautious around it.
Maybe caution is a work hazard. :-P
Actually, hp, SF6 and CO2 aren't changing the pitch of sound passing through them. What's happening is that because the velocity of sound in those gases is different than in air, the relationship of wavelength to frequency is altered from what it is in an air medium. Since the resonances of your horn (and also of the vocal tract, in the case of the video) are determined by wavelength, their center frequencies are shifted- downwards if the velocity of sound is lower than that in air, upwards if it is higher. This in turn alters the pitch of the note you're blowing, or of the primary formants of your voice if you're speaking.
Thanks, Ktesibos -- I knew it was more complex than that, but I'd forgotten the mechanics of it.