




Date: Mon, 02 May 1994 00:13:36 -0300 (ADT)
From: MJNAUGHTON@amherst.edu
Subject: cyberspace region

tom stamm suggests "we" participate in the RGZ as the "Cyberspace Region".
I have no fundamental objection, but I echo Tonto when informed by the Lone
Ranger that "We are surrounded by Indians" -- "What to you mean, 'we', white
man?"
Such participation requires someone to do it - do I hear a volunteer?
Mike "No, my hand is NOT raised!" Naughton





Date: Mon, 2 May 94 04:38:36 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Weddings again...

Hello again !
        This coming Autumn I'm going to be my brother's best
man at his wedding. I was through at his place in Edinburgh
this weekend (got very drunk last night...we decided to have
the stag night in Dublin. You can tell when things are getting
out of hand when the stag night's in a different country :o)
... anyway, this afternoon I was standing outside an ice cream
shop with the bride to be, and there was a big display of
wedding stuff, including favours (do they say the same thing
in the US? I mean the little bags of sweets the bride hands out)
Anyway, she said she was going to have to wrap up loads of
sweets like that & she'd probably ask me for a hand , so I
suggested origami ones like at Japanese weddings, and she
seemed quite taken with the idea.
        So: any suggestions on what to make ? I'll need to make
about 200 of whatever it is, preferably a selection of small
animals which can hold the sweets. What is the traditional way
to do this in Japan anyway ?
        BTW: No way am I making 1000 cranes. :o)

        Ever curious,
               Baz.





Date: Mon, 2 May 94 04:42:37 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Re: On the Mathematics of Flat Origamis

I made a booboo in the last letter - never try folds in your head
without trying paper too: reverse folds dont produce chains which
are all the same type of fold along their length. They, too,
produce chains which alternate and can terminate inside the square,
but only at the end of another chain of his type, as with
squash folds.
        Tom: you reference 'Origami Science & Technology' in
your paper: I assume that's the stuff from the conference
proceedings that you were sent from Japan. At the time I think
you said you were only sent this paper. Did you end up getting
the whole volume? What else is in it?

        I've been volunteered to give an informal lunchtime
talk here by one of my flatmates. (So what if I do share a
flat with two other nuclear physicists? They're practically
the only women in the department!)...she originally put me
down to give one on 'The relationship between George Formby
and Queen Nefertiti', but it looks like I'm going to get asked
anyway, and I thought it would be fun to talk on this stuff -
teach them all how to make frogs at the start, then this along
with the old New Scientist stuff, finishing by getting people

        Cheers,
               Baz.





Date: Mon, 2 May 94 05:34:37 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: folding fujimoto's flat origamis-help

Does anyone know how to fold them... or want to try.

I have his book which is in Japanese.

There are pictures of some of the neatest origami I've seen, and
partial crease patterns that apparently are enough to show how to
fold the origami. I can't visualize making them without having
much greater dexterity.

The origamis are sheets of repeated patterns. The sheets appear
to be of a translucent material so that the origami is shaded
darker where there are several layers. They are something like
tessellations.

Rona





Date: Mon, 2 May 94 07:17:54 ADT
From: "M.J.van.Gelder" <M.J.van.Gelder@rc.rug.nl>
Subject: Re: origami book for the blind

Rona,

I have seen this book at our convention in Holland tendays ago.

m>Just got a BOS newsletter and they review a book on origami for
m>blind people. I don't know if the diagrams are raised or if
m>the directions are in braille.
m>
m>Has anyone seen this book?

The diagrams are raised, including the crease lines and arrows. It looks
and feels (!) nice. Only the page numbers are in braille. The accompanying
text is on a compact cassette. I think it is only in Dutch at the moment.

Maarten van Gelder                   M.J.van.Gelder@RC.RUG.NL
Lichtboei 210                        Rekencentrum Rijksuniversiteit RuG
9732 JK  Groningen                   Groningen
Holland                              Holland





Date: Mon, 2 May 94 08:06:37 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: origami books for libraries

Martin,
   The origami book for the blind sounds like a really good idea.

   I would like to encourage people to try to get more origami books
in libraries. This one sounds like it's an easy sell. I don't know
what you all are planning to do with your collections, but giving
them to libraries is tax deductible.
   All this past year I was working on starting a collection in our
college library. I had a donor in mind who didn't come through, so
I've been going the local route and the grant route. When I finally
thought hard about it I lined up enough possibilities for a sizable
collection. I'm aiming to be  a significant regional study collections
primarily for our students and regional teachers. So far, I've gotten
$300 worth of books ordered by the library. That's about 30, which
is more than our local bookstores or public library have. (It would
have probably been more cost effective to donate my books.) I've got
a very solid chance at another $1500 next fall and an excellent chance
at another $2000 after that. Sounds like a lot of money for books, but
by library standards, they keep telling me it's modest, which means
it's not that hard to get. It should cover most all of the materials
that foca sells, plus most books in print(sold in US?) plus library
overhead. Nothing was really a hard sell. Continguous space was
the biggest problem.
     Does anyone know of a large publically accessible origami
collection?

 Rona





Date: Mon, 2 May 94 10:53:31 ADT
From: Soylent Green <rhudson@yorkcol.edu>
Subject: Bird Boat

I think it was in one of Kawai's little books.. a swan container that could
hold small candies.. made out of white, it would be striking..

Rob

"Tread Softly, Grasshopper; The Buffalo is Slow, but the Earth is Patient"





Date: Mon, 2 May 94 11:06:31 ADT
From: sea@umcc.umich.edu (Steve Arlow)
Subject: Re: Weddings again...

>  [...Discussion of wedding favors...]
>       So: any suggestions on what to make ? I'll need to make
> about 200 of whatever it is, preferably a selection of small
> animals which can hold the sweets. What is the traditional way
> to do this in Japan anyway ?

Noshi.  They are described in about every third Origami book.
Your occidental guests will likely not recognize them, though.

 ---> Hey lemur-boy, this .sig's for you! <---  | Steve Arlow, Yorick Software
 "Your simian countenance suggests a heritage   | 39336 Polo Club Dr. #103
  unusually rich in species diversity."         | Farmington Hills, MI 48335
         -- Calvin (Bill Watterson)       :)    | sea@umcc.umich.edu





Date: Mon, 2 May 94 11:23:24 ADT
From: "Nigel Pottle, T-L, Erin Woods Elementary" <NPOTTLE@cbe.ab.ca>
Subject: Re: Butterfly bomb

I'm sorry your librarian was not able to locate the info on the Gross book.
You can let her know that the bibliographic info is:
Gross, Gay Merrill. The Art of Origami. 1993. Friedman Group, New York.
The Friedman Group address is Michael Friedman Publishing Group, Inc,
15 West 26 Street, New York, N.Y. 10010

Nigel Pottle (new to the list, and hello. I'm a librarian.





Date: Mon, 2 May 94 13:04:09 ADT
From: mkfire@aol.com
Subject: Origami thank you notes

My 12 year old daughter just had a birthday party and received lots of
wonderful gifts.  Since she and I love origami we thought it would be fun to
write thankyou notes using origami in some way.

We need a model that is kind of simple(cause we need to fold a number of
them) yet elegant.  Any suggestions of specific models or books to check
out???

Thanks for any ideas,
Marsha





Date: Mon, 2 May 94 13:23:46 ADT
From: Charlotte <CSTEFFAN@CMS.CC.WAYNE.EDU>
Subject: Re: origami books for libraries

Rona - As I mentioned in a past note, I'm a cataloger at Wayne State University
 libraries. When I got interested in origami, I checked to see what we had in
the libraries here, and at Detroit Public, Main Branch. We had relatively lit-
tle and Detroit Public had a modest collection. When I went to actually GET the
 books, not one of ours was on the shelves (and none were checked out) and DPL
fared a little better. I don't know about your part of the world but from our
collections, I know that certain types of materials have a very short shelf-
life: pop-up books, erotic art, sex manuals, anything on C and now I would add,
 origami books. I think this may be partially by their nature and partially be-
cause some of the best seem to go out of print and when people want them, they
take them. I'd be interested in knowing how your collection fares; are you at a
small college? Libraries book funds have generally suffered drastically over
the last number of years and I think for most, origami books would be hard to
justify against other needs. I wish you luck with your grant proposal and if
you do find a good origami collection, I think many of us would like to know
about it, especially if they will interlibrary loan.
                                         Charlotte





Date: Mon, 2 May 94 15:41:36 ADT
From: barber@sugar.neosoft.com (Alex Barber)
Subject: Cyber/Net Regional Group

>Rona suggested we identify ourselves as a "regional group".  I don't know
>what all the ramifications are, but I' sure of at least two things:
>a) we'll be invited to send a representative to a "regional group break-
>fast" organized by Paul Kruger
>b) we'll be "invited" to contribute to his "regional group" newsletter/
>idea-swap.
>(Note: I'm not saying this is BAD, I'm just saying this will happen!)  Caveat
>Folder!
>  By the way, I LIKE the idea of identifying ourselves with "OLO" on our name
>badges (since I, for one, am TERRIBLE with names!)
>Mike "I like to fold, but I have limited enthusiasm for TALKING about folding"
>Naughton

Since I used to be in FOLD, an origami zine w/ Paul Kruger (sp?), I
wouldn't mind volunteering to stop by the regional meeting breakfast.  It
might be easier for me since he and I have met before at previous
conventions and through the zine.

Alex Barber

barber@sugar.neosoft.com

I will not be pushed, filed, stamped, indexed, briefed, debriefed or
numbered.  My life is my own.





Date: Mon, 2 May 94 15:54:46 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Re: On the Mathematics of Flat Origamis

More thoughts...
        Tom, on page 4 of your paper you state:
'Not only is Theorem 3.2 necessary for a flat origami, it is sufficient
as well. This surprising fact implies that whether or not a set of
lines can be used to make a (locally) flat origami depends only on the
angles about each vertex, not on the arrangement of mountain or valley folds'

(Theorem 3.2 is the one Kasahara calls Kawasaki's theorem, the alternate
angles must add up to 180 degrees.)

The statement is true up until the last comma. I realised this when I
was thinking about global flatness, I tried to classify the different
kinds of rips you can get. One, which is a global problem, is folding
too deeply into a pocket; another is the local problem of attempting to
reverse fold too far, e.g. with this pattern:
       /m
      /
v ---<---m
      \
       \m

Which satisfies both m-v=2 and the angle condition, but cannot be folded.
Kawasaki's theorem is necessary and sufficient for an edge colouring
to exist; 'm-v= +/- 2' is a necessary property of such a colouring.
To proceed as I described in my previous letter, to prove global flatness
by constructing  fold sequence, we must be able to prove that a
_particular_ colouring _and_ordering_ of folds is flat.
        The rest of this letter describes an algorithm I thought up
this morning to determine if a particular colouring is legal; ordering
is more difficult, I'll come on to that at the end.
        To create a sufficiency condition, one way to approach the problem
is to prove that certain special cases are foldable, then show that
all diagrams can be decomposed into these cases if they are foldable; this
is what I did, and it proved useful.
        Consider a sequence of folds around a vertex. All such sequences
break down into sequences of the form:
1) ...mvmvmvmvmvmvm... (alternating)
2) ...mmmmmmmmmmmmm... (of one type: alternatively ...vvvvv...)

We apply reducing processes on sequences of each type in turn:
1) mvm -> m, vmv -> v, i.e.

/       /
\  ->  /
/      \
\       \
(because of the shape of this diagram, I call this process 'sigma reduction')

2) mvv -> v, vvm -> v, mmv -> m, vmm -> m.
We only reduce in this case when the outermost fold of the 'pair' has an
angle greater than or equal to the inner one. To see what this means,
draw the edges of an mmmmmm.... sequence where the angle monotonically
decreases. You will quickly realise that it must be followed by a vvv...
sequence where the angle monotonically increases (after we have reduced
internal sequences, this is a double spiral).
This process looks like:

________ \        __________
       v\ \m  ->  __________> m
  ______/ /
m<_______/

...so I call it 'spiral reduction'.

Repeatedly sigma- and spiral- reduce until only two folds are left:
the 'spare two' in m-v=2. sigma-sequences can always be folded flat;
spiral sequences may rip through each other if the angles are wrong.
- that's how we detect unfoldable sequences. Note that the end product
of all this will be a pocket which can no longer be unfolded; the sum
of the angles is no longer 360 degrees.

        I missed out above how to figure out the angles of the segments
you reduce to; that's because I just spotted a problem in sigma-reduction,
when it looks like:
/     ... this, the sequence can't be reduced. I have to require that
\     one of the outer segments is larger than its neighbouring
 \    inner segment. I'm not sure right now if this is general.
 /
/
\
I'll figure this out later...(I hope)

On ordering: just as Kawasaki's thm said 'there is a colouring' - the proof
being the demonstration of just such a colouring, this method says 'there
is an ordering', and effectively constructs it (reduction is like glueing
flaps of paper together so that they are in a fixed order). This looks
to be even harder to extend to a global context because the implied ordering
at each vertex may be different, for the same polygons.(I say that off the top
of my head - as with everything else, I may be wrong).
        This is all a bit useless from a mathematical viewpoint, I'd guess;
but this stuff would be easy to do with a computer representation. It may
not even be original, but I've never seen it before.

        Cheers,
               Baz.





Date: Mon, 2 May 94 16:33:38 ADT
From: hull@cs.uri.edu (Tom Hull)
Subject: Folding Fujimoto's wild stuff

Rona, I think I have that book too. Mine has flat "pattern" origami,
as well as lots of 3-D "pattern" origami. There's also some stuff
on using modular origami to teach students about the structure of
molecules. Does this sound like the same book?

All I can suggest is to be VERY VERY patient with Fujimoto's folds.
In my book, he only gives the crease pattern and you have to figure
out the rest. It is do-able, but first you have to figure out which
lines are mountains and which are valleys.

Pre-creasing the paper into a grid helps too. Although sometimes this
grid needs to be a grid of squares, while other times it needs to be a grid
of equilateral triangles. The latter can be hard to do acurately (but I
gives instructions on how to do this in the beginning of the diagrams
for Bob Neal's Tesselating Fish in _Origami, Plain and Simple_ (yes!
another plug for my book!)).

Hope that helps.

--------------- Tom "Woebegone" Hull





Date: Mon, 2 May 94 17:26:26 ADT
From: hull@cs.uri.edu (Tom Hull)
Subject: Re: On the mathematics of Flat Origamis

Hey Baz! I'm glad someone is having fun with my paper! Cool Beans!

> "I would suggest a solution based on what we really do: find the
> class of folds which preserve flatness"

I didn't like this approach (from a mathematical viewpoint) because
it doesn't account for the possibility of "truely impossible folds".
That is, crease patterns which are technically foldable, but for which
no folding sequence exists. I don't see any reason why such beasts
SHOULDN'T exist, and if they do I'd like to be able to examine them
with an origami-math model.

> This has probably been old hat to Tom & Joseph, I'd guess

Don't count on it! I never pursued your line of thought when I was writing
my paper, and who knows? I like your sigma and spiral reductions. They
may prove useful.

For example, to overcome the problem posed at the end of my paper
(how to keep track of when multiple flaps will rip through each other)
I was thinking that it'd be nice to know how many different mountain-valley
assignments (what Baz calls "crease colorings") are there for a given
set of flat origami crease lines? This is a combinatorial problem, and
the little attention I've given it has convinced me that it's not an easy one!
For example, some crease patterns only admitt a few possible valid
mountain-valley assignments, while others admitt lots! (The waterbomb
base is an example of one that admitts lots of different mountain-valley
assignments).

Anyway, Baz's reduction ideas might help get at the nature of this
combinatorial problem. BUT I'm not convinced yet that if the reduction
is foldable, then the original crease-pattern was foldable! (Admittedly,
I just read his posting a few minutes ago, and haven't given it much
thought.) I wanna proof!

>Tom - does current research go much further
> than the stuff in your paper ? Also, what journals should I be looking
> in if I wanted to see origami maths ? I don't even know which
> section it would come under in the Mathematical Review.

My paper is the extent of the research that I've done (so far). And as
far as I know, there is hardly anyone doing this kind of research.
Robert Lang is doing some stuff, but his approach is much more analytical
(he likes to think of a origami fold as a continuous function from
the square [0,1]x[0,1] into R^3, and uses some advanced calculus) and
the questions he asks are more from a designer/engineering perspective.
He just wants to know how to make the folds work, not WHY they work.

The only other mathematician that I know of whose research mirrors mine
is Toshikazu Kawasaki, although I'm sure there must be other Japanese
mathematicians doing this too. So look up Kawasaki in the Mathematical
Review!

As far as a MR math classification number, I have no clue.

> you reference 'Origami Science & Technology' in your paper...

I wrote to Kawasaki, and he sent me copies of his papers in these
Proceedings. One is on mountain/valley crease relationships (where he
proves Kawasaki's Theorem) and the other is on "Higher dimensional
origamis". The latter is pretty wacked, and I'll describe it later if
anyone's interested.

Aside from this, I don't have any of the other articles from these
Proceedings (but Kawasaki's are on page 200+, so this must be quite
a volume!). Kawasaki also sent me some of his other papers, but they're
all in Japanese! (Except one, "Crystalligraphic Flat Origamis", which
I described in detail about 2 years ago here. Look in the archives.)
So once again I ask, CAN ANYONE READ JAPANESE?

Also, if Baz or anyone else wants to "use my stuff" in a talk or paper or
whatever, that's fine with me. Just give me credit and try to spread
my paper around to as many interested parties as possible!!

Incidentally, I've been on a 2-month origami-math research hiatus, since
I've been taking my PhD comprehensive exams (which are over now! Yeay!!!).
As soon as my life approaches a near-equiibrium like state, I hope
to hop on the saddle again. Thanks Baz, though, for the ideas!

---------------- Tom "munchkins never die!" Hull





Date: Mon, 2 May 94 17:34:10 ADT
From: lavin@MIT.EDU
Subject: Re: Origami thank you notes

I've seen quite a few samples of origami-note-paper scattered in
various books; many of them involve (warning -- purist alert!)
rectangular paper, half of which is folded into a model, with the
other half being used for the writing.  I can look through my books
tonight at home and some titles tomorrow.

Some are pretty simple -- one that comes to mind has a small sailboat,
kind of like the Friends' logo, at one corner.  And there are some
really cool "noshi" (that's a ceremonial small gift wrapper) patterns
that have the traditional crane folded into them.  I don't know if
that's too complicated for your project, though.

Anne R. LaVin       |"Say, Pooh, why aren't YOU busy?" I said.|  \|/ ____ \|/
lavin@mit.edu       |"Because it's a nice day," said Pooh.    |   @~/ ,. \~@
(617) 253-0115      |"Yes, but---"                            |  /_( \__/ )_\
Information Systems |"Why ruin it?" he said.                  |     \__U_/

          (Hitchiker's guy courtesy jittlov@gumby.cs.caltech.edu)





Date: Mon, 2 May 94 17:55:52 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: Re: origami books for libraries

Charlotte,
Thanks for the info about shelf life. Does making the collection non circulating

significantly increase shelf life?

Re: justifying origami books
Our school does teacher training, in particular in the Math and Ed depts.
Origami is pretty established in these areas. At least in math ed, at
the last National Council of Teachers of Math annual meeting there wer
six talks on origami. I think simple origami is accepted and teachers
are receptive to more of it, and an easier learning curve.

We also do in-service teacher training. I'm hoping to put some sort
of core course in with origami, and the library books support all
of these activities.  Also, independent study courses are supported
by the library collections.

I've heard of schools in NYCity being interested in offering origami
courses for teachers but not being able to find people to teach.

Community service is another angle that the school is beginning to
support again, as a small criteria for promotion. This translates
into a student decorated origami Christmas tree to me.

Research is another angle. Last year I got an internal research grant
to complete work on my origami polyhedra book among other things.

People are being supportive and willing to give institutional support
to origami activities, so I'm going to try until it's apparent that
I can't get any further.

The most compelling justification for money is to support courses.

Re: collections of origami books
I'll let you in on a little known collection that I visited in 1979.
It was in a special room in one of the libraries at Stanford University.
The collection was a gift of the estate of a Father McNaul and it occupied
maybe 8 shelves. I can't remember how I learned of it, but I used to
spend a lot of time at the Origami Center at Lillian Oppenheimers and
I must have read about it in her papers. Well at that time, the collection
hadn't been expanded since the time of the gift and I think I needed a
letter from Lillian to get me permission to look at the books. I've never
heard anyone mention this collection since, although at the time I knew
people at Stanford that were very interested in origami, even they had
not heard of the collection.
    I sort of remember being allowed to xerox some things, but I was
mostly interested in geometrics, and I don't remember finding anything
spectacular.
     I think maybe there was correspondence among some folders from
the 60's.

Rona





Date: Mon, 2 May 94 18:13:00 ADT
From: mkfire@aol.com
Subject: Re: Origami thank you notes

Ann
It would be great if you would look through your books for something that
could be used for a thank you note.  Let me know.  What does all the
punctuation that you used mean??? I only know :).   Where can I find out
about all the other composed "graphics".

Thanks for the info.
Marsha





Date: Mon, 2 May 94 18:47:34 ADT
From: Charlotte <CSTEFFAN@CMS.CC.WAYNE.EDU>
Subject: Re: origami books for libraries

Wayne has a big education school but I can't say I know much about math ed.
I catalog the children's books for the collection and the reason we have a
large collection of those is for teacher training. Our book funds have remained
 pretty good and if the Education School wanted origami books, they could get
them ordered without much problem. Hard to say why they don't. I would expect
big collections at the large public libraries (like Detroit Public) but they
haven't been funded as well as they should be recently either.
The Stanford collection sounds fascinating. I'll have to see if I can turn up
anything about that but maybe Stanford wants to keep it a secret. Thanks for
the information.
        Charlotte





Date: Mon, 2 May 94 19:17:41 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Re: On the mathematics of Flat Origamis

You wanna proof? I gotta da proof!

Well, actually I don't. But here's why I think a reduction is a
legal fold...as a diagram. You should be able to see from this
why there is a problem when the middle section is too big.
(I should really explain that these pictures look at the intersection
of the fold with a plane...lengths of lines relate to size of
angles about the vertex)
\                  \
 \/\                \
    \/\       ->     \
       \  /           \  /
        \/             \/
via sigma reduction. As I said at the end of the letter, it's like gluing
flaps together to make the deepest pocket possible out of the sequence.
Now consider what happens at the end of the sequence: either the paper
folds back on itself - into the pocket -or folds out the way, continuing
the steps. Anything that can be tucked into any of the smaller pockets
can be tucked into this deeper pocket. Again, I said I was _imposing_
an ordering to the folds: one which I 'know' to work.

Spirals: these are more difficult to draw! I'm beginning to be aware of
problems with this reduction too (urk). It's difficult to see this reduction,
because most 'real' spirals in models have other things in them; the
point is that we only reduce a spiral once we remove the other things:
I can't see there being much argument with every fold being either a sigma
or a spiral, since that's the case for all the triples -
mmm,mmv,mvv,vmm,vvm,vvv are spirals,
mvm,vmv are sigmas.
Anyway, what does spriral reduction 'mean' ? Here's a picture of an
object inside a spiral:

a_________________
b________________ \
c_______________ \ \
                \ \ \
      __________/ / /
    e/ d_________/ /
     \____________/
The layer bd is trapped. The reduction does this:
a_________________
b________________ \
       d_________> >
c_________________/

Anything which would fit in the small spiral ac would fit in this
equivalent pocket. Since the rips can't occur in the alternating
sigma sections, if they exist they must be here; check that the angles
in the spiral ac worked.
        The thing to notice here is that the spiral pocket can't
be any deeper than the outermost layer. The problem I just spotted
is the position of e in the first diagram; what happens if it lies to
the left of a, c? Problems, problems...

        The combinatorial nature of the colourings is a major headache:
I got stuck with a PhD project that turned out to be NP - in both time
and storage. Complete dead end. These ideas may give you some leverage,
but really they're intended for when you _know_ how it's to be coloured,
and want to check that this is ok - which is how a origami program
like OriGo might work.

As for truly impossible folds: this is connected (from a practical point
of view) with the combinatoric thing, and a question I asked before.
Try folding a corner to a point 1/Pi across the square. See? you need
a ruler. Now, this may not be 'impossible' from the point of view of the
mathematician with one in his back pocket, but if we stick to bisections
and lining things up, we can only fold to points whose co-ordinates
aren't transcendental. (what's the word for this? I forget). The limit
on the position of vertices give the idea of an 'n-th order' origami,
whose vertex co-ordinates come from an nth order (polynomial) equation.
The neat thing with these points is that we can put a limit on the number
of folds that it could _possibly_ take to form that origami; Brute force
enumeration of a few orders ought to be enough to find your kind of
'impossible' fold if it exists...along this vein, I keep meaning to
sit down and write out the proof of Haga's theorem, which is going to
be involved in this somewhere.

        Any chance of getting copies of what Robert's doing posted ?

               klaatu burada nikto,
                     Baz.





Date: Mon, 2 May 94 22:03:15 ADT
From: SPARKER@U.WASHINGTON.EDU
Subject: Weddings and Cranes

Why does everyone seem to think that folding a 1000 cranes is such a chore
for a wedding?  It really doesn't take that much time and its a gift like
no other.  Cranes make great party favors too.  There's a "Crane-shaped
receptacle" in "Colorful Origami" by Toyokai Kawai (it's one of those really
small books).  I think all origamists should bite the bullet and fold 1000
cranes.  You can always donate them to a local charity or peace celebration.

Just my two cents worth.

Sue "Tsuru" Parker
sparker@u.washington.edu





Date: Mon, 2 May 94 22:43:48 ADT
From: Shmuel Weidberg <shmuel@io.org>
Subject: Re: Weddings and Cranes

On Mon, 2 May 1994 SPARKER@U.WASHINGTON.EDU wrote:

>
> Why does everyone seem to think that folding a 1000 cranes is such a chore
> for a wedding?  It really doesn't take that much time and its a gift like
> no other.  Cranes make great party favors too.  There's a "Crane-shaped
> receptacle" in "Colorful Origami" by Toyokai Kawai (it's one of those really
> small books).  I think all origamists should bite the bullet and fold 1000
> cranes.  You can always donate them to a local charity or peace celebration.
>
> Just my two cents worth.
>
> Sue "Tsuru" Parker
> sparker@u.washington.edu
>
Have you done it yet? How long did it take you? :)

--------Shmuel Weidberg, Toronto, Ontario-------------------------
If you think you might know somebody who knows me, drop me a line.





Date: Tue, 3 May 94 03:30:49 ADT
From: jadr@oce.nl (J. Adriaanse)
Subject: Re: origami book for the blind

Maarten van Gelder wrote:

>Rona,
>
>I have seen this book at our convention in Holland tendays ago.
>
>m>Just got a BOS newsletter and they review a book on origami for
>m>blind people. I don't know if the diagrams are raised or if
>m>the directions are in braille.
>m>
>m>Has anyone seen this book?
>
>The diagrams are raised, including the crease lines and arrows. It looks
>and feels (!) nice. Only the page numbers are in braille. The accompanying
>text is on a compact cassette. I think it is only in Dutch at the moment.
>
>
>Maarten van Gelder                   M.J.van.Gelder@RC.RUG.NL
>Lichtboei 210                        Rekencentrum Rijksuniversiteit RuG
>9732 JK  Groningen                   Groningen
>Holland                              Holland
>

The book was made by Elsje van der Ploeg and Hilly Jongsma, both from Holland.

They did an enormous job to get everything right. The pictures were folded
from wet (but not too wet) very rough sandpaper, the lines are pieces of
wire glued to the surface. Then they put sheets of a special kind of plastic
over the whole thing, melted the plastic a bit and vacuumed underneath. That
way the plastic took the shape of the paper and wires. When cooled down,
this plastic stays in shape, so the actual book consists of sheets of
plastic. You can feel the roughness of the sandpaper (which stands for 'color').

The drawings are in yellow and red for the benefit of people who can still
see a little. It was very difficult to get the lines of the drawing in the
right spot on the plastic.

The text is, as Maarten said, on a compact cassette. They made the Dutch
version first and John Smith (of BOS) helped a lot with translating into
English. Other languages are possible if need be. Playtime is one hour. You
do not need to stop the cassette all the time, it plays music in 'folding time'.

The book is dedicated to Saburo Kase, a blind Japanese folder. Elsje told me
that he sees with his fingers, in a whole different way than we do. For
instance, by feeling he can imagine all sides of an folded object at once,
where we can only look from one angle at a time!

The price is some $70. Each book has to be made from the original models...

If you are interested, write to:

Uitgeverij Interval
attn: Jacqueline Kuipers
de Vlotkampweg 77
6545 AE Nijmegen
THE NETHERLANDS

Greetings,
Sjaak Adriaanse





Date: Tue, 3 May 94 11:45:29 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: Re: origami books for libraries

Charlotte,
    Well, I don't understand why there aren't more origami books in
libraries either. If anyone has an idea of how to make the whole
system start moving in this direction I'd like to hear it.
    It seems like a chicken and egg problem. Teachers buy books
from bookstores that carry books that teachers want to buy.
As I mentioned before, Dale Seymour and Key Curriculum Press and
Janson Publications(?) have started carrying a few origami books
the past year or so, which indicates an increased demand from the
education community to me. Also, Key Curriculum Press offers
geometry institutes for teachers that have an origami component,
that is better than nothing, but too small in my opinion. The
institutes are offered out of UC Berkeley and carry some kind
of credit. Key Curriculum Press also offers a book called
Patty Paper Geometry, which is geometry constructions from
squares of translucent paper. They sell the patty paper too.
It seems like a good price, around $5 for 1000, yes a thousand,
sheets. It might be good for some origami models. I was going
to mention it to the foca business committee.

Rona





Date: Tue, 3 May 94 12:12:04 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Re: On the mathematics of Flat Origamis

I have a most remarkable proof (for which there is no
room in this margin) that if spirals can be reduced
then _all_ sigmas can be reduced. The trouble is, I don't
think spirals _can_ all be reduced. The trick is that at
some point you must connect up the edges at the start and
finish, so that it goes all the way around the vertex.The
one irreducible sigma turns out to require a reducible
sequence along with it to be connected,ie every sequence
with an irreducible sigma can be reduced.
        The irreducible spiral fold, is,however, perfectly
legal. I do have some ideas to get around this, but nothing
works so far.

               cheers,
                     Baz.





Date: Tue, 3 May 94 12:48:31 ADT
From: lavin@MIT.EDU
Subject: Re: Origami thank you notes

I've found two books (I suspect that there are others, but a quick
search yeilded enough interesting stuff) that had origami folded into
notepaper in an integral way, as opposed to sticking a folded model
onto a piece of notepaper (which is fun, too.  :)

They are:

"Living Origami" (in English) by Takuji Sugimura
 (ISBN 4-586-54041-9 C0176)

        notepaper with:
        - giraffe
        - waterbird
        - elephant (this one's pretty abstract)
        - plump crane (this is a crane with the really fat
                     body and short head and neck)
        - dog

"Origami Fantasy" (in Japanese) by Takuji Sugimura
 (ISBN 4-586-50777-2 C0176)

        notepapter with:
        - steamship
        - sailboat
        - catamaran
        - flower (sort of morning-glory like)
        - samurai helmet

Both are published by Hoikusha Publishing Company, and are part of
their "Color Books" series (the very small-format books with plastic
covers.)

I like both the books quite a bit.  They're an interesting example of
the folk-art-ish side of origami (use of non-square paper, some
cutting, etc.)  Some of the models are pretty abstract, in the way
some of the "traditional" origami abstracts things, if that makes any
sense.  And some are really quite elegant.  There's a wonderful model
of a camel lying down in "Origami Fantasy" which is very abstract (it
has no legs at all!) but manages to convey camel-ness really well.

Anne R. LaVin       |"Say, Pooh, why aren't YOU busy?" I said.|  \|/ ____ \|/
lavin@mit.edu       |"Because it's a nice day," said Pooh.    |   @~/ ,. \~@
(617) 253-0115      |"Yes, but---"                            |  /_( \__/ )_\
Information Systems |"Why ruin it?" he said.                  |     \__U_/

          (Hitchiker's guy courtesy jittlov@gumby.cs.caltech.edu)





Date: Tue, 3 May 94 14:26:13 ADT
From: LHODSDON@smith.smith.edu
Subject: 100 cranes

Perhaps I brought some curse down on my house, but I gave a gift of
850 or so cranes--they took me about two months of folding while I
watched television in the evening.  I knew I couldn't finish because
school started, so I strung and gave as a gift those that I finished.
No one cared that there weren't _really_ a thousand.

I've seen truly lovely mobiles of ~100 cranes -- very nice though perhaps
without quite the same symbolism.

-Lisa
lhodsdon@smith.smith.edu





Date: Tue, 3 May 94 19:48:52 ADT
From: SPARKER@U.WASHINGTON.EDU
Subject: Re: Weddings and Cranes

Yes I have folded 1000 cranes, at least 10 times.  If I just do it consistently
while watching TV at night, I can do 100 a night.  That's about 4 hours of
work.  I don't usually have that consistency, so figure 50 per night and
that's 20 nights.  A little planning and you're there.  School would tend to
get in the way of this.  All day concerts, like Lollapalooza, are great for
folding many birds and so are long plane flights.  These are also opportunities
to show others a traditional fold.

Sue
sparker@u.washington.edu





Date: Tue, 3 May 94 21:17:30 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: 2nd RFD:rec.crafts.paper (newsgroup)

(2nd RFD)
Proposed by:    Brian Ewins <gapv64@udcf.gla.ac.uk>

Group name:     rec.crafts.paper
Distribution:   world-wide
Summary:        A newsgroup for the discussion of various paper
                related crafts.

CHANGES:
The name has been changed from rec.crafts.paper.misc, to
rec.crafts.paper, after discussion.

JUSTIFICATION:

Currently, there exists a mailing list on the net (origami-l@nstn.ns.ca)
for the discussion of origami. There is also an ftp archive of models,
and several discussion groups on various BBS's on this and other
related topics.
        The origami list, currently the main area of discussion, has
grown rapidly, generating a high volume of mail, and has begun to
fragment, with unrelated discussions taking place simultaneously,
a clear indication that the list has grown beyond its remit, and that
a constituency exists for the proposed group.
        This RFD is intended to make users aware that there will
shortly be a vote, but also is intended to allow discussion of the
name of the group, and its charter. The change to the name proposed
is to reflect the view that we do not expect the imminent break up
of this group into further groups.

CHARTER:

The proposed group will provide a forum for the discussion of allarts and
     crafts involving paper, both the methods and materials.
These include, but are not limited to:

*origami        (paper folding)
*kirigami       (paper cutting)
*paper making
*paper sculpture
*papier mache
*related computer software.

This message is being distributed to the following places:
USENET groups:
        news.announce.newgroups
        rec.crafts.misc
        rec.arts.misc
        soc.culture.japan
And the mailing list:
        origami-l@nstn.ns.ca
Followups should be sent to news.groups (this should happen automatically)
or, if you are subscribed, to the list.

**********************************************************************

NOTE

This RFD is being issued in concordance with the guidelines set in the
"How to create a new usenet newsgroup" FAQ regularly posted to
news.announce.newgroups.  Please refer to this article if you have any
questions about the newsgroup creation.

Unless the discussion indicates a need to resubmit a new RFD, the CFV
will be posted approximately three to four weeks after the posting of
this RFD. It will be co-ordinated by a Usenet Volunteer Votetaker
(a neutral third party).

*********************************************************************

Brian Ewins,
Dept of Physics & Astronomy,
University of Glasgow,
Glasgow G12 8QQ





Date: Tue, 3 May 94 23:09:05 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: patty paper

In a previous post I mentioned patty paper. Well someone asked me about
it so I actually opened my package which says the paper is 6x6 squares.

It seems a good weight for folding BUT it's not exactly square! It's
about 1/4 inch off which to me seems unsuitable for folding. I don't
know if it's just the batch that I got, but I'm going to complain.

I wonder how close to square paper has to be to be called square?

Rona





Date: Wed, 4 May 94 00:37:01 ADT
From: Shmuel Weidberg <shmuel@io.org>
Subject: Proposed Newsgroup

How will we go about voting and what exactly will we be voting for?
Supposing the voting works out when will the newsgroup start posting and
who will administrate it?

--------Shmuel Weidberg, Toronto, Ontario-------------------------
If you think you might know somebody who knows me, drop me a line.





Date: Wed, 4 May 94 01:26:40 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Re: Proposed Newsgroup

|
| How will we go about voting and what exactly will we be voting for?
| Supposing the voting works out when will the newsgroup start posting and
| who will administrate it?
|
There will be a letter marked CFV:rec.crafts.paper. This contains an
explanation of how a vote gets passed. There is a box in this letter
in which you type 'YES' or 'NO'. Votes are either counted automatically
(if the 'bot program recognizes the voting card) or counted by the
neutral third party, the 'UVV' who you send your vote to: again
this is all explained on the CFV form. What is voted on is one or more
of the following:
creation of a named newsgroup which is unmoderated;
creation of a named newsgroup with a _named_moderator_
deletion of a newsgroup.
The 'name' aspect of this also includes the charter (ie you can have
two alternate charters proposed for the same group name)
Votes are _not_ transferable between different propositions in the usual
method; but the UVV's have recently begun to gear up for some form
of STV.
        If it passes, the newsgroup will start posting about 14 days later
(I think less). If it is unmoderated, as proposed, _no_one_ administrates.
The vote is to convince the various sysadmins that there is demand for the
group, since only the big 7 (comp,sci,rec,soc,talk,news,misc) are widely
distributed.
        You will have 30 days in which to vote.
        I would guess it would be _unusual_ to say the least (stupid
also springs to mind) to actually propose two very similar but mutually
exclusive propositions in the same vote; such as two names for the
same charter, since this would split the vote and almost certainly
prevent the proposing of that group again for the next 6 months. That's
why the RFD exists; hopefully a proposal is bashed out which a majority
already clearly supports.
        alt.* groups require no votes, which is why they have a rash
of empty groups (some just of letters, most of content) and variable
distribution.
        It has been suggested that we will be susceptible to various
plagues if we are unmoderated: e.g.
'Green Card' style advertising,
'Make-money-fast' chain letters,
Kibo posts (Kibo greps all of the news, and cross posts to any groups
which mention him. Many alt.braincells are fans of this and do it too)
... The first two only become a problem when people _reply_ to them -
as all replies are cross posted too ! The correct response is to complain
 to the person in question's sysadmin.
        Similarly, Kibo is mainly a problem if he or his minions are
replied to.
        The major consideration from my point of view, is that moderated
groups are _much_ harder to get past a vote; the choice of moderator
and the very idea of moderation is _always_ controversial.

ObOrigamiStuff: I was looking up Abstracts today, thought I'd check for
origami at the same time; turns out many papers with origami in the
title are really on microsurgery...I'd like Lang's Cuckoo Clock for my
rhinoplasty ... not!

| --------Shmuel Weidberg, Toronto, Ontario-------------------------
| If you think you might know somebody who knows me, drop me a line.
|
               Cheers,
                     Baz.





Date: Wed, 4 May 94 07:14:09 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: Re: Proposed Newsgroup

How much traffic do you think the new newsgroup will have?

Will this list stay in place as an alternative... maybe being
'mirrored' on the new list.
Are individuals allowed to subscribe to the new newsgroup or do
you have to access it through a reader.

Rona





Date: Wed, 4 May 94 07:25:18 ADT
From: Bruce Stephens <bruce@liverpool.ac.uk>
Subject: Re: Proposed Newsgroup

> How much traffic do you think the new newsgroup will have?

My guess is enough to justify one; I honestly don't know in absolute
terms.

> Will this list stay in place as an alternative... maybe being
> 'mirrored' on the new list.

That's up to the owner and participants of the list.  Because of the
more general nature of the newsgroup, it's likely that it won't be
mirrored.  On the other hand, rec.arts.dance has a clever gateway to a
ballroom mailing list: all mailing list messages get sent to the
newsgroup, and all articles from the newsgroup which have certain
keywords in them get sent to the mailing list; perhaps we could do
something similar with our situation?

> Are individuals allowed to subscribe to the new newsgroup or do
> you have to access it through a reader.

If you mean can somebody that doesn't get USENET access the newsgroup
as a mailing list, then that depends on somebody setting up a mailing
list.  I'm told there are no technical problems doing that---it's easy
to do---but I can't offer to do it.

> Rona

Bruce                   Institute of Advanced Scientific Computation
bruce@liverpool.ac.uk   University of Liverpool





Date: Wed, 4 May 94 07:41:50 ADT
From: "A.G.BATEMAN" <A.G.Bateman@newcastle.ac.uk>
Subject: Re: Robert Harbin.

David Lister (B.O.S president) informs me that the publishers of the
Harbin books will not republish Origami 2,3 or 4 as they don't fit in
with their ' Teach Yourself' series. There was some discussion about
publishing a book of the best of Origami 2,3 and 4 but I have not
heard any more news.

                                         Alex Bateman

Technical doesn't mean difficult





Date: Wed, 4 May 94 07:56:44 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Re: Proposed Newsgroup

We could have this in the vote, ie
'do we have a two-way mirror ?'
Or: just vote on it within the list. The traffic on the new group
will probably be _double_ what it is here; if not immediately,
then probably soon after. This is just a wild guess, really, but
there will be a much higher profile for the group, and other interests
(such as those mentioned in the charter) will want to be discussed.
This might make it really bad for those left on the list, if its mirrored.
For those on the group, the new traffic will not be a problem since
you can skip it easily. I think the group will be voted for one day;
if not this time, the next, or the next, because the number of people on
the list will continue to grow.

               Baz.





Date: Wed, 4 May 94 07:59:24 ADT
From: Brian Ewins <gapv64@udcf.gla.ac.uk>
Subject: Lang article

I just found Robert Lang's Christmas 89 New Scientist article-
WOW! He explains in (enough) detail his technical folding
method, and it has pics of some models including the Black
Forest Cuckoo clock. I was totally gobsmacked: this is even more
incredible than I had been led to believe! Read! Read!
(Now I've _got_ to buy his book)

I found some of the other cited origami articles as well, notably
'paper folding, digit patterns and Groups of Arithmetic Fractals'.
This is essentially 'Dragon' curves (you know those paisley pattern
fractals ? Not the coloured Julia set ones, the black-and-white ones)
It's actually very closely related to the gubbins I was spouting
about sigma and spiral reductions...except that my stuff does
variable angle segments about a vertex, this paper would imply using
equal-angle segments, but can say more about them. All of its 'folds'
are at 90 degrees instead of 180: draw some cyclic patterns of edges
which turn like this and you'll see the kind of fractals I mean.

I also found the Applied Optics ref...on folding computer networks.
This is _bizarre_. (actually, it falls within the remit of my thesis
and I may be able to cite it!). Essentially, you can replace a grid
of a network by one column, and appropriate delay lines, and this
provides an algorithm for doing it. I guess this is particularly
essential in optical computing: someone I know worked in a room
which was filled by an optical nand gate, so the less components
you have to build the better, and delay lines are easy.
(the refs mentioned are in old mail: archive 23 or 24 I think, I
can't check right now because my machines crippled. Look for PACS)

        Cheers,
               Baz.





Date: Wed, 4 May 94 08:05:37 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: Re: Proposed Newsgroup

I'd be for this new group if I knew I could subscribe to it via a
mailing list...which evidently requires someone setting one up.
I might be willing to do this if I knew what was involved and
how much maintenance it took and if it required resouces on my
computer.

Accessing information via USENET is much less convenient to me
than the current system. I would also have to try to convince
some people to make the group available to our system.

I imagine that there are people on the list without access to
USENET. I can use it remotely at another school. But our school
didn't have it accessible to the general population until last
fall.

Rona





Date: Wed, 4 May 94 08:10:56 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: Re: Robert Harbin.

Alex,
    Tell us about the 'Teach Yourself' series, of origami books?
I don't think I've heard of them.

Rona





Date: Wed, 4 May 94 08:14:45 ADT
From: GURKEWITZ@WCSUB.CTSTATEU.EDU
Subject: origami fractal article by Donald Knuth

There was a reference to folding a dragon curve and other fractal
folds worked on by none other than very famous computer science
professor and mathematician Donald Knuth in an old BOS newletter,
maybe numbered between 100 and 115.

Does anyone know how to do this or remember the reference.

Rona





Date: Wed, 4 May 94 10:59:50 ADT
From: Soylent Green <rhudson@yorkcol.edu>
Subject: Arnold Rimmer

Alex:

Is the BOS's president's name REALLY David Lister?  I seem to remember a large,
red mining ship bearing a passenger by that name on the telly..
