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Path: utzoo!decvax!tektronix!tekcrl!tekirl!donch
From: donch@tekirl.UUCP
Newsgroups: net.misc,net.sci
Subject: Re: Helium Balloons
Message-ID: <246@tekirl.UUCP>
Date: Fri, 17-Oct-86 18:55:17 EDT
Article-I.D.: tekirl.246
Posted: Fri Oct 17 18:55:17 1986
Date-Received: Sat, 18-Oct-86 07:13:40 EDT
References: <520@zen.BERKELEY.EDU>
Distribution: na
Organization: Tektronix Inc., Beaverton, Or.
Lines: 19

In article <520@zen.BERKELEY.EDU>, mikel@cory.Berkeley.EDU (Mike Liang) writes:
> [POP!]
> 
> I just opened up my dead helium ballon of two days to breath in and speak like
> like Donald Duck today and it didn't work.  Does the helium mutate or diffuse
> out of the balloon and regular air diffuse in or what?
> 

Helium will diffuse through ANYTHING!  It is a very small molecule (it comes
in twos--He2) and is almost impossible to keep in or out of things.  In high
vacuum work, helium is the standard media used for leak checking, largely 
because of its incredible mobility.

So, yeah, it just leaked out of your balloon, but not through any hole you
or anyone else made (unless the fill hole was tied in a knot instead of
sealed or heat-fused.)

Don Chitwood
Tektronix, Inc.