Hexafluorid.

pretty sure it's some guys with some fishing wire and too much time on their hands.

I dunno, I think the "pouring" air thing kinda tipped me off.

Spell it correctly.

What they have is Sulfur hexafluoride. It's 5.11 times as dense as air. It's non toxic, although it's byproducts can be extremely dangerous.

Another interesting point is that inhaling this gas will make your voice sound deeper. Sound does not travel as fast in this medium. Helium can transmit sound very rapidly, hence making your voice squeaky.

If my not entirely rudimentary knowledge of chemistry serves me right it's not just "hexafluoride", the fluorine (or more correctly fluoride ions) has to be bonded to a central atom, such as sulfur for instance (which has the required amount of free spaces, i.e. six, to bond to make a hexafluoride) thusly making sulfur hexafluoride. Odorless, non-toxic and non-flammable.

The density is indeed much much denser than regular oxygen (or even the mixture of mainly oxygen and nitrogen that we call "air"). Oxygen has a density of 1.429 g/L, nitrogen of 1.251 g/L and sulfur hexafluoride a density of 6.13 g/L.

Tellurium would work instead of sulfur as well (making tellurium hexafluoride), however that variant is highly toxic and would not be applicable in a situation such as in the video. Xenon or uranium would also work in making hexafluorides, however both creates a crystalline compound instead of a gas.

No fishing wire, just clever chemistry.

Haha, damn, I took too long in typing and making sure I got my facts straight. Good one Russell, glad to see I wasn't barking up the entirely wrong tree anyway.

It's spelled correctly in German.

This gas has an important medical use. I think they use this gas to refill the eye when they fix detached retinas (they have to suck out the internal contents of the eye to do this operation). Cool eh?

@CP I know right. I'm suprised that "spell it correctly" is still in his own post.

All of what Russel says is true, but it is important to note that while non-toxic, the fact that it is heavier than air means the risk of suffocation is much greater.
Think about it; when you breath out with helium, it all rushes out as soon as you open your lungs. With this, it will sink to the bottom of your lungs, and may not be breathed out for quite some time (the deepest you can breath out is around 70%).

So, if you breathe this stuff in, a good way to get it out is by hanging upside-down with your mouth open?

David, the article explains that the tank is filled with a gas that is more dense than air. When the hand in the video is "pouring air" into the boat, it's actually pouring the more dense gas into the boat. The boat is then unable to float on the gas any longer. No big mystery.

Wow, that david guy must be mentally challenged.

This is the same gas that was in the circuit interrupter that failed in the 500,000volt (phase-phase, delta) substation arc video. It sees extensive use in the electrical industry as an insulating gas. Its neat stuff, but alas expensive and ozone depleting.

http://www.panickker.net/article6.htm

That Dave guy must have some serious mental challenging going on b/w the extra chromosomes in his brain.

I like how when he scoops up some hexafluorid, it makes the boat move like waves are hitting it, as the hexafluorid moves to fill in the scooped up part. Very neat experiment.

I am not so sure one's voice goes squeaky because sounds travels faster in Helium. If that was the case, the sound waves would slow down back to normal speed when moving into air before reaching the listener's ears. The reason is probably more related to the amount of mass inside the lungs. Just like a thicker string has a lower pitch than a thiner one (all other things being equal).

The gas is often called SF6...

Marcelo, it doesn't really have to do with the lungs but rather the vocal cords. The helium being less of less density than regular enables the vocal cords to actually vibrate faster, i.e. in a higher pitch, than normal. Just like sulfur hexafluoride is more dense and enables the vocal cords to vibrate slower, with more bass.

Sulfur Hexafluoride, SF6, has a global warming potential that is 22,200 times greater than Carbon Dioxide. It's a little scary to see a whole tank of it like that.
http://www.eia.doe.gov/oiaf/1605/gwp.html

all technical information aside, I think the coolest point of all is that you can actually see the where the layer of Sulfur hexafluoride and air meet.. there is a faint greyish layer in the shadow just before they release the foil tray.. you can see it slightly as they scoup the Sulfur hexafluoride into the tray..

Econerd, the amount they have there, or even compressed in the tank, shouldn't be so much in the greater perspective, especially if we consider how much cars and factories spew out of carbon dioxide every day all around the world. Drop in the ocean if anything.

If I'm not mistaken, this is the same gas used to demonstrate how light aerogel is. That was what, 4 or 5 years ago?

SF6 is one of the gases generally used in electrical substations as a circuit breaker.

Couldn´t we pour the gas in a concrete riverbed, and then have vehicles hovering on top of it like flying cars?

Hehe, awesome stuff. Definitely appealed to my chemistry geek. I need to ask my professors for more info on similar gases now :D
Sadly we couldn't float much more on it than a foil boat as it's just not dense enough. As for the comment of seeing a tank of it, you've got a tank maybe 0.5m x 0.3 x 0.3. Volume wise, that's not even approaching a mole of the substance, let alone anything that could cause environmental damage. Sure if every home had a small tinfoil boat bobbing in a tank of SF6, maybe we could worry. Until then, that car parked outside is a bigger danger to the environment.

Several years ago, Jay Leno demonstrated the voice lowering characteristics of SF6. He sounded like Barry White after inhaling the stuff. In order to get it out of his lungs, he bent over and coughed a few times. He doesn't seem to be any worse for the experience.

Dear All,
Amazing. Can somebdy enlighten me as to where more Experimmental Demos of this sort could be found in the Net?

Hexaflorid is a correct spelling, if you are in Germany or anywhere east of there.

@Jake Yea. You, Me and CP all brought it up so the post was fixed.

http://www.youtube.com/watch?v=hbrDwxZ6LSQ
german hiphop guys using hex-flor...

Another thing about SF6 (Sulfur Hexaflouride) is that it is an oxygen displacer, so whatever you do, don't breathe it in and try the stupid voice tricks like with Helium. It's very dangerous!!!

Hey, I'm a teacher. Several of my students brought this video to my attention, showing the interesting clip on you-tube. It is cool. I'm sure chemistry teachers could have a field day with this one. However, I do have two concerns: 1. Is this gas readily available? 2. And, just how dangerous is this gas when inhaled--perhaps repeatedly?

According to Google,SF6 is also linked with Wikipedia. Could someone please add a post, blog, public service announcement, disclaimer etc., describing the possible dangers of inhaling this gas for kicks? Certainly, Nearly everyone at some point has goofed around with a helium balloon at a birthday party, but repeated use could be quite deadly. On a lighter note, how dangerous could it be? I mean Jay Leno used it--maybe it settled in his chin :)

We use SF6 for our linebackers in the field....We've always treated it as a dangerous gas. Here I am seeing and hearing of at least 2 people inhaling it. Definitely need more health information about it. Way neato trick with the boat. Don't know if my boss will let me fill up an aquarium with it tho....that shit ain't cheap. -J- West TX

Jay and I had fun, it's not dangerous if you don't breathe it repeatedly and you don't have to bend down to exhale it I've found. Just breathing exchanges the gases well enough. I do it at least twice a month in my show,
cheers,
David
P.S. Only use the very pure sf6, and don't use balloons without washing them inside and out, the manufacturers put some nasty powder in them to protect the rubber, you do not want to inhale it.

SF6 is used as an insulating (arc quencher0 in high voltage switchgear. It should not be allowed to be purged into open atmospere. It is a greenhouse gas that takes approximately 3000 years to decay. We need to be very careful with this stuff!

Best example I've seen of helium vs. sulphur hexaflouride.

http://www.youtube.com/watch?v=XjCmwuGKR6g

definately neatorama!

SF6 is used in sound detonation in the window industry. They will blend the nobel gases (Argon or Krypton usually) with SF6 to help lessen sound transmission.

Another cool experiment to do would be to fill the bottom half of the with SF6 and the top half with helium. Then if you put a small balloon filled with regular air, it would sink through the helium but would float on the SF6, it would be suspended half way.

Just wait till David Blaine gets a hold of this one.

Great information. I haven't heard before of this gas. I like the video! Thanks

Wow thats neato! The gas you describe and is shown of the video, i've never seen before.