hydrogen or helium filled innertubes

Factual Questions
1

I am certain most will feel this question is entirely without merit and pure fluff but I am genuinely interested.
How much lighter would I feel if I squeezed myself into the middle of a truck tire innertube that was filled with hydrogen or helium? Would I be able to jump higher than before? Just get sore armpits from the inflated rubber pressing against my underarms? I know that I would not fly away. This is something I would like to do in the coming springtime and would like to know what I could expect from the experience.

2

You wouldn’t be able to jump any higher because the force that is holding you down is gravity. Just because you enclose yourself in a membrane filled with a light gas, does not mean that gravity will stop “pulling” you down with the same force. The only way to decrease the effect of gravity is to rise further aboove the earth’s surface.

3

Air, mostly N[sub]2[/sub], weighs about 0.8 grams/liter at standard temperature and pressure (STP). Hydrogen weighs about 0.09 grams/liter under the same conditions. An innertube filled with hydrogen would thus be 0.71 grams/liter lighter than an air filled tube. At 4 liters per gallon and ~5 gallons for a good size innertube, that works out to a decreased weight of about 14 grams for the lighter tube.

4

It might work if the inner tube is light enough. I don’t have the numbers to calculate it off hand, but the bouyancy you would get is equal to the weight of the volume of air the inner tube occupies, minus the weight of the inner tube and the volume of hydrogen inside it. The problem is that inner tubes are designed for high pressures, so the rubber is likely to be so heavy you would not get any lift from it.

5

While gravity will still affect you, the idea (it seems) is that the boyancy of the innertube would help counter it some. But unless the innertube is floating all on its own in the first place you’ll only make yourself heavier.

6

Ha! I first read the OP that way too! I thought he was climbing inside the inner tube. Obviously, (note the armpit comment), he’s only going to be inside the inner tube center. Like wearing a hula hoop.

7

In practical terms I don’t think a typical car or truck tire innertube’s worth of helium will be enough to counteract the weight of the relatively thick rubber wall of the innertube. Your net weight would likely be more. You need a lot (volumewise) of helium or hydrogen to get any substantial lift and the thing holding it has to be lighter than the volume of gas it encloses.

8

With the data given by Squink it seems one liter of hidrogen in air would have a buoyancy of about 0.71 grams/liter. For a man who weighs about 85 Kg you would need about 120,000 liters (32000 gallons). Clearly an inner tube will give you zero buoyancy as the tube weighs more than the buoyancy of the gas inside. The inner tube idea is just silly and that is why balloons were invented.

I recall that guy who went up in a lawnchair tethered to weather ballons. How many balloons did he have and how much gas?

9

Wasn’t that regular helium balloons, sailor, like you can get in supermarkets? I think I saw it on tv the other day. I’ll search.
Peace,
mangeorge

10

According to this article, he used 45 weather balloons. They appear to be roughly six feet in diameter, so each one would have about 85 cubic feet of helium and lift about six pounds. If you had eight or ten strapped to you you could jump a lot higher than normal (I don’t know how to calculate exactly how much higher).

Eric

11

No, you’re right. Forty-two six foot weather balloons. Witness;
lawn chair larry

12

Larry used weather balloons

Even if you filled your inner tubes with Hydrogen or Helium gave you some initial bouncing benefit, the fact that the gas would quickly leak through the rubber and leave you with a flat tire would impede your bouncing ability.

13

So I see.
I’d swear I saw some guy (on tv) in a lawn chair lifted by a bunch of regular helium balloons. They weren’t in staggered groups like Larry’s, but in one long bundle. It was on videotape. Larry’s trip wasn’t.
Don’t do it, raisinbread. Our society no longer appreciates oddballs. :frowning:

14

Aw phooey.

15

If you wish to pursue this experiment and follow in the steps of Lawn Chair Larry, please use helium. In addition to letting you do munchkin improv, it is a relatively safe gas. When considering hydrogen, recall May 6,1937 in Lakehurst, NJ-Hindenburg.

16

We just went over this on the board, but the Hindenburg disaster was not a hydrogen explosion. What happened was that the envelope caught fire, which is not surprising in retrospect, considering that it was coated with what amounts to rocket fuel. The hydrogen contributed only negligably to the explosion.

17

It will have the reverse effect. I think you want to use the bouyancy of hydrogen to feel lighter. But you will feel heavier in an atmosphere of hydrogen than in an atmosphere of air(because buoyancy is the difference in densities of you and the surrounding).

So if you want to feel lighter - get into water or even higher density liquids.

18

andy_fl, he’s not getting into the inner tube, he’s…nevermind.

Chronos, the root cause of the Hindenburg not withstanding, hydrogen is extremely explosive. I’ve seen an ordinary balloon of hydrogen ignited, about thirty feet away, and I was amazed at the concussion. I don’t know what would cause a spark to set it off–but helium is easier to get anyway, isn’t it?

19
      • Hydrogen, helium, nitrogen, oxygen, CO2 and argon are available on-hand at any decent welding shop, they aren’t difficult to get at all. Welding shops also often serve as outlets for other scientific gases such as those used for constructing neon lighting.
  • “Explosion” is a slippery term.
    …
    Regardless of that, oxygen and hydrogen are used to gas-weld aluminum. The mix burns very faint blue at about 5400 degrees F, where oxyacetylene burns at 6300 degrees. The hydrogen would have been difficult to see burning under the circumstances, much less from grainy B&W film decades later. As I heard, the Hindy was coated with acetone/oil-based varnish (which certainly is flammable) but the hydrogen didn’t exactly help slow things down in the “burning” department.
    ~
20
      • A bunch of helium balloons could make you feel “lighter”. Could be fun to play with for a day, but I dunno if I’d have the nads to tie enough on to fly away (–I live too close to a military base to be flying around without official permission).
        ~