I remember that in 24 hours, the volume of a latex balloon filled with
He would decrease by about one half.
You could ballpark the permeability from some hand calculations knowing
the above, and buying a balloon to measure the uninflated membrane
thickness and calculate the thickness from blowing it up to about 10 -
13 inches in diameter.
YOu might estimate the pressure from other means, but it is surely less
than something like 2 atmospheres.
However, there is nothing like searching real reference books from the
rubber industry instead of googling. Or, as has been suggested,
contacting (even by phone, for heaven's sake) people working in the
For a lot of things, Google just won't work because nobody will put up
all the data for no fee and little reward for doing so. Free data is
worth the same as free advice, for the same reasons.
Actually, the reason for the request is to compare data obtained
experimentally with independent sources. In this experiment students
are given a He filled balloon & are required to determine the
permeability of He in the balloon's membrane by measurements over
It is close to one atmosphere and depends on the degree of inflation.
Graduate students doing this experiment take the pressure variation
with balloon inflation into account. It doesn't make much difference.
Graduate students have also explored the variation of permeability's
variation with "stretch".
No question about that.
I disagree. I believe that it is possible to have good data freely
I think that NIST or a similar agency should be responsible for
publishing all data obtained through federally funded programs. While
such data is publically available in principle it is not available in
The marginal cost of such publishing would be small and the benefits
to society would be large.
You said "Free data is worth the same as free advice, for the same
The data I refer to was obtained at relatively high cost to society
and should be availible to those who paid for it in the first place.
Further, I argue that while out-of-copyright data is distributable
there is little such data actually available. The difficulty here is
that the intended finite time period of copyright protections are
being destroyed in the interest of protecting commercial interests in
trivialities like Mickey Mouse images.
I hope that someday you learn what copyright means.
Data itself isn't usually copyrighted.
The data in the telephone book is not copyrighted, but the arrangement
of the data on the page is covered by copyright.
You can have data be proprietary.
But it is hard to publish data in any form and still complain that it is
So, your comments about "public domain" data do not appear to be
consistent with current law and practice.
You can extract data from tables of the "Handbook of ......." and freely
use it or publish it. You cannot physically copy the table and republish
it... without permission. You could reformat it(the data in the phone
book), as many several different publishers reformat the data in
telephone books, in areas like mine served by three different telephone
"The Handbook of ....." doesn't own the data of the hundreds or
thousands of individual researchers who conducted the labor to establish
or measure the data.
Perhaps you are inflicting incorrect views of data and copyright on your
Your comments are helpful.
I hope the following clarifies my thoughts on this topic.
The original intent of the copyright laws is clear; an author's rights
to a particular expression should be protected for a finite time
period after which that expression passes into the public domain.
I would like to see free public access to out-of-copyright materials
like whole tables of data and figures like phase diagrams. Examples I
can think of include images of some tables of data from the 1920
edition of the CRC Handbook of Chemistry and Physics or images of
individual phase diagrams published in the 1920s.
Cosmetic rearrangement of data tables to avoid copyright protections
seems disingenuous to me. While merely retyping a table in a different
font or changing column spacing might be sufficient to satisfy a
judge, the purpose of the effort was get around the copyright
protection, not to create an original expression. The modified
expression is clearly intended to be a derivative work.
Perhaps an argument can be made that placing a scanned image of a
phase diagram on a publically accessible website is a sufficiently
significant alteration of the original expression to be considered an
original work. Can we successfully claim that enabling electronic
accessibility to the data is a sufficent modification of the
expression to warrant release from existing copyrights? Probably not.
Imagine that I make a machine that scans a phase diagram from a
printed page, then vectorizes that data and publishes it on a website.
Would or should this be OK from a copyright standpoint?
How far do I have to go in modifying the expression of a factual data
collection to be legal or ethical?
The age of a particular expression is much easier question to answer.
I believe the continual legislative extensions to the period of
copyrights which are in effect granting permanent copyrights will
ultimately harm society by permanently frustrating access to data
which happens to be part of a collection.
The thing about data is that it's not expression, it's facts. You can
no more copyright the fact that water boils at 100deg C and freezes at
0deg C (a very simple example of a data table) than you could copyright
the fact that WWII started in 1942.
Going back to the telephone book example from another poster, one of the
baby-bells did attempt to assert copyright over the data in the white
and yellow pages against competing phone books and reverse phone books.
In court it was shown that the competitors were simply scanning the
baby-bell's phone books and OCRing the data into a database to generate
their phone books, mistakes, omissions, and all. The baby-bells lost, no
copyright on data.
If speaking of US involvement, Pearl Harbor was bombed on Dec 7, 1941 and
war was declared the following week. Germany actually got their
declaration in first. But the war actually began in 1939 with the
invasion of Poland.
The big thing in 1942 was our navy trouncing the Japanese fleet at
Midway. Some say that was the real turning point for the Japanese could
never mount a seriously credible naval threat in the Pacific afterwards
email@example.com (dave martin) wrote in message
Just a little comment about the extensions to copyright.
While Disney ( for example ) certainly benefited from the recent
extension, and may well have lobbied for it, that wasn't actually the
In our interconnected modern world it seems and seemed logical that
copyright protection should be standardised across countries. The US
and most of Europe were at 50 years after the creator's death ( and
companies had slightly different rules ). Germany however was at 70
years. When the EU, as part of the Single European Market project
standardised copyright protections, it went to the German standard :
That then led to the US following suit.
As I say above, while big corporations may have benefited, it was
actually the spread of international trade and the WWW that led to the
move to standardise.
There is also one of the odder stories from the UK Parliament. When
the bill to standardise came to the House of Lords, one of the " Noble
Members " ( I think it was Baroness Trumpington, a rather splendid
woman now sadly departed. Think of one of Bertie Wooster's more
terrifying Aunts.) reminded the House that the copyright for Peter Pan
was actually held by Great Ormond Street Hospital for Children (
having been left to it in JM Barrie's will ). It had run out under the
50 year rule, and would be reinstated under the 70 year one. But it
would then run out again shortly.
She thought that this was quite clearly a bad idea, and so suggested
that Peter Pan alone should have permanent copyright : and included in
the speech that " As everyone knows when a child says they don't
believe a fairy dies, and it is necessary for us to clap to keep that
fairy alive. So I would ask the Noble Members who support this
amendment to clap their approval " ( Languid drawls of " Hear Hear "
and mass clapping. )
The amendment passed of course.
I saw in the news a few days ago somewhere that a new film of Peter
Pan is held up because the Producers do not want to pay Great Ormond
St : and while this permanent copyright only covers the Uk, they still
want to distribute the film there when made.
Not a lot to do with materials in the above . Sorry.
The quick and dirty way around copyright is to set up web space in a country
that does not respect copyright laws thought a like minded local and post
what ever you wish by sending it to him one CDROM and having him put it up
on the web page. That method would not leave any tracks.
You could probably get away with renting the web space yourself and posting
from here but there would by a trail to follow that lawyers could use to
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