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Would this floating idea be plausable? Answered

Basically, I was thinking in my sleep as I usually do. I thought about how less dense things float on top of more dense things. And this got me thinking towards this:

Are there any gases that are more dense than the human body?

If so, we could float on this particular gas (with gas masks or oxygen tanks of course). This also led me to think about:

Are there any liquids which are lighter than air? We could have a swimming pool of sorts that floats on the ceiling.

All we would need is the right chemical. Any scientists out there?

(I know it is unlikely as states of matter generally mean that in terms of density, Solid>liquid>gas.


There's always indoor skydiving, which uses a giant fan to keep you in the air, which I recommend you try (much safer than regular skydiving). Although it's similar, it's not quite the same. A gas that's more dense than a human currently doesn't exist (not to say it won't!).

Humans have a density that fluctuates around 1, similar to water, and the heaviest (Known) stable gas is Tungsten Hexafuoride, while 11 times heavier than air, it is corrosive and is nowhere near dense enough to support a human. Also, you would face the same issue with a liquid that is lighter than air, it would most certainly be MUCH less dense than the human body as it is unable to float even air, though there is a liquid much lighter than air (10^13 times actually) it will not float humans. However there are some liquids that you are (almost) able to stand on, liquid Mercury comes to mind, able to float iron as water can float styrofoam, a full grown man (if he can balance himself) can stand on Mercury and sink no more than a few inches (If he can avoid ingesting the toxic metal.) The closest thing you would find to a "floating" swimming pool is ferrofluid suspended in a magnetic field, ferrofluid will support a human being, but only if it is kept perfectly suspended in a magnetic field, or it will come crashing down to the floor taking anything suspended in it along for the ride.

A floating swimming pool or levitation gas is an interesting idea, but impossible by todays technologies.

That would be AWESOME if there was one! I would love it! Then again... You think about floating on gas and all this scientify stuff when you go to sleep? I just think how tired I am and I just fall asleep. Lol


8 years ago

Put simply, no, you can't. You can with some liquids though (as Lemonie said), and if the air is moving "up" at the right speed (like one of those vertical wind tunnels).

And by-the-way, the states of matter are Solid>Liquid>Gas>Plasma, or when referring to chemicals Aqueous is one too (basically just dissolved in water)

Aqueous isn't really a state of matter as my chemistry teacher knows it. It's irrelevant anyway :P

Meh, according to the gcse examining board it is.

Gases and liquids are both fluids, if you get fluid denser than yourself it's a liquid. Similarly, fluids lighter than air are gases.


 air is a mixture of gases and there are many gases heavier than air

There aren't any gases "heavier" than a person though.


 yes i agree with you there there is not a gas lighter than any solid THOUGH
it is possible for somethings net weight to be less than a solid even if it contains a solid ex. a ballon its net weight is less than air so it floats

In Las Vegas and at the CityWalk Universal here in Los Angeles there are a couple of installations that sort achieve the affect that you are looking for. They have embedded a high power fan in the floor, and enclosed it in a cylinder shaped room. When this fan is turned on and a person assume a sky diving like position they are Levitated on a column of air. The Hollywood installation is better because the system was constructed entirely of Plexiglas. The views inside and out are incredible.

Check out this link here.


Come to Hollywood and we'll make your dreams come true.

we do float on two gases. its just that they are very thick and under pressure.

The human body has the same density (close enough!) as water, 1 g/cm3, or 1 kg/L (that's how the units were defined).  All gases have the same molar volume, 22.4 L/mol, or a molar density of 4.46 x 10-2 mol/L.  To convert from moles to grams, just use the atomic or molecular weight (hydrogen is 1 g/mol, water is 18 g/mol, and so on). 

Let W be the molecular weight of the hypothetical gas you are seeking.  You need a density of more than 1 kg/L to float in such a gas.  So you want W*(4.46e-2)>1000, or W > 22,400.  Moelcules with weights in the tens of kilodaltons (in molecular biology, the "dalton" is the name for g/mol) are proteins, RNA, DNA, and so forth. 

I don't think you're going to find a gas of protein molecules anywhere near room temperature, and I don't think you want to try floating in a gas at 500 or 1000F.

Liquids and solids have effectlvely the same density, determined purely by the intermolecular spacing, which is about the same as the molecular size.  So the arithmetic argument above, turned in reverse, gets you the same result.

No, there are no gases in which you could float, and no, there are no liquids at STP which are less dense than air.

wow, ur smart. im just learning about this in science class :P

:-D  I'm sort of smart.  I've also been a professional physicist for the past 15 years, and hve both my undergraduate degree and Ph.D. in physics.  So I've just had a lot more time to learn this stuff, and to know the right terminology to use when searching for information.

Great that you're learning about this stuff!  I sure hope you enjoy it, and good luck!


8 years ago

As far as I know, there are no gases that are denser than liquids or solids.  The best you can get is moving the gas at a certain volume and speed, so that things "float" on the gas.  Think skydiving simulator.  ;)

But I'll leave that up to the scientists to confirm...

Well, there probably can be, but not at STP (I don't think 22.4 kDa macromolecules would vaporise at room temperature).  See my dimensional analysis below.

You've got it backwards. You'd need a gas that was more dense than the human body in order to float on it. Such a thing does not exist.

True. In any case, the only way I know of to make gases denser is to change them into liquids, which sort of defeats the purpose.

Have you ever heard of the Neutral Buoyancy Laboratory (NBL) ?

Anyway, my intuition says that it is going to be difficult to find a liquid or gas which is both more dense than the human body, and also breathable.  Although I have read of such ideas for a "breathable liquid"

As far as I know this liquid breathing stuff is still science fiction, as briefly seen in that movie, "The Abyss".

So I think some kind of wearable breathing apparatus is going to be necessary, and that brings the discussion back to SCUBA diving, and the NBL.