Date: Tue, 27 Sep 2005 21:32:10 +0200

Author: Urs Lauterburg

Subject: Re: H-O-Bang ?

Post:

Dale and other Tap-lers who helped me with the H-O-bang,

.....so far so good. I have not gotten the hydrogen to try it out yet
but I will. Dale, how do you make the 2/3 hydrogen, 1/3 oxygen ratio?
Just by looking at the ballon's volume and estimating? What do you
fill first?H?O? Does it matter?

Every kind of advices and comments make me more confident with this
undertaking. I think I stay with the candle on a stick for ignition.
We do the shooting of a red balloon inside a green one with a green
power laser when we talk about absorption of electromagnetic waves.

Thank you guy for your mails to this and regards

Urs


>Urs,
>
>We do this all the time.....not a real problem. You can use 12 inch
>diameter (30cm) balloons without any real problems EXCEPT you don't
>want to do this under a smoke or heat detector that will trigger a
>fire alarm.
>We just use a candle on the end of a 2 meter ruler to ignite the
>balloon. It is very impressive to ignite the hydrogen balloon in the
>dark. Another version is to use a balloon that is in the shape of
>the Hindenburg for the hydrogen.
>We've never had any problems with static discharge. Even if you get
>this it happens on the outside of the balloon where the gas is not
>present.
>For the hydrogen-oxygen balloon just fill it in the approximate
>proportion of 2/3 hydrogen, 1/3 oxygen. Even if you are off by
>quite a bit in this proportion, you will not be able to tell unless
>you are very experienced and know what to look for, because the
>explosion will overshadow everything else for most people. See:
>http://faraday.physics.uiowa.edu/chem/5B30.92.htm for a picture of
>out setup. In this picture, it is the lower balloons we are
>igniting. The upper balloons are only used to hold the lower
>balloons in position above the bench. We ignite the balloons in
>order from right to left. On the right is a helium balloon, so that
>people can see what just the balloon popping sounds like. The next
>balloon is the hydrogen balloon. The third from the right is a
>balloon filled with oxygen, which pops just like the helium balloon
>because there is no flammable fuel which it can react with. Also
>note that this balloon hangs down as oxygen is heavier than normal
>atmosphere. The balloon on the far left is the hydrogen-oxygen
>balloon. When you set this one off, make sure you are wearing eye
>and ear protection. Also, inform your audience to cover their ears
>and open their mouth ( to equilize the pressure on both sides of the
>ear drum).
>
>Let me know if you need more info.
>
>Later,
>Dale Stille
>U of Iowa
>
>
>
>
> On Fri, 23 Sep 2005, Urs Lauterburg wrote:
>
>> Dear Taplers,
>>
>> We have not done this so far because it is more a chemical
>>reaction but now some of our younger, less peaceful professors
>>wants to show the hydrogen-oxygen reaction by filling a ballon and
>>ignite it later, very much like the large hydrogen ballon shown at
>>the physics monster show in SLC.
>>
>> Now I assume it will be alright to buy a flask of hydrogen, then
>>fill a ballon (of course without smoking at the same time) and
>>later ignite it with a candle on a long stick. Before actually
>>doing it I want to ask you guys for comments on the necessary
>>safety measures to perform this without any harm or damage. I would
>>also like to know how large the ballon should be blown up. Has
>>somebody ever experienced an accidental ignition form a discharge
>>of a static voltage? As we know rubbing a ballon can easily produce
>>a large potential. I do intend to survive this experiment.
>>
>> Any comments are most welcome....
>>
>> Wish you a good weekend
>>
>> Urs
>>
>> Urs Lauterburg
>> Physics demonstrator
>> Physikalisches Institut
>> University of Bern
>> Switzerland
>>
>>
From urs.lauterburg@phim.unibe.ch Tue Sep 27 15:58:34 2005

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