The error that jolts you out of WSOD...

[Cryptoengineer]

I just finished listening to a reading of Silverberg's 'Hawksbill
Station' on Escape Pod. I think I started it once, decades ago, but
didn't finish it.

The main plot McGuffin (this is revealed in the opening pages, so no
spoiler warning), is a penal colony '1 billion years' in the past, to
which the prisoners are irreversibly sent via a one-way time machine.

The problem is that there are trilobites and brachiopods, creatures
that didn't exist until a bit more than 500 million years ago.

Silverberg could have said '500M YA', and absolutely nothing in the
story would change. But everytime I heard 'billion', it bugged me. A
lot.

pt

[Dan Goodman]

In Connie Willis's short story "Just Like the Ones We Used to Know,"
it's snowing around Christmas in cities all over the world -- including
Honolulu. At a conference of experts, character says -"It never snows
in Hawaii."

It does snow in Hawaii; though only at very high altitudes. An expert
would not say that.


--
Dan Goodman

[Robert Carnegie]

The history revealed in Douglas Adams'
_Life, the Universe, and Everything_
is IIRC twenty billion years old,
in a universe broadly similar to the
present day. But the universe in fact
is less than 15 billion years old.

[Robert Carnegie]

It's probably just what it says in the
brochure, and close enough for government
work. And it discourages the criminals
from figuring that all they have to do is
survive for 500 million years and they've
escaped.

Historically our estimates of the age of
the Earth have usually pitched low.
But presumably any reference book would
give you estimated dates when trilobites
lived - and that they only lived in water,
I think.

It also was reckoned that there were no
fossils at all, or almost none, before
the "Cambrian explosion". I suppose you
could believe that critters were around but
weren't getting fossilised for some reason,
such as being warned of impending death by
their trilobite-sense and escaping.

[Robert Carnegie]

Bob Shaw's _The Ragged Astronauts_ has some
nice bits about the culture in the story
inventing, I think, algebra, but then
totally annoys me by having someone explain
that in that universe, pi equals three.

Pi is fundamental in mathematics, and it
can't have another value.

Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
or something like that.
You can't change /that!/

In other pi news, Star Trek book _Memory Prime_
has a compter that worked out pi as a repeating
decimal (in which case it would be just an
improper fraction, which it isn't), and at
the end of Carl Sagan's _Contact_, the reader
(but not yet the characters) is informed of
the discovery in pi of a message from God.

Well, God isn't allowed to change pi, either.
(Even though the bible also incorporates an
apparent belief at the time that pi is 3 -
at least for government work...)

[Jaimie Vandenbergh]

On Thu, 07 Jun 2012 22:11:11 -0500, Dan Goodman <dsg...@iphouse.com>
wrote:

>In Connie Willis's short story "Just Like the Ones We Used to Know,"
>it's snowing around Christmas in cities all over the world -- including
>Honolulu. At a conference of experts, character says -"It never snows
>in Hawaii."
>
>It does snow in Hawaii; though only at very high altitudes. An expert
>would not say that.

I'd be more worried about "all over the world" - including Melbourne
and Auckland?

Cheers - Jaimie
--
I like my coffee how I like my women... frothing.

[Jaimie Vandenbergh]

On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie
<rja.ca...@excite.com> wrote:

>Pi is fundamental in mathematics, and it
>can't have another value.
>
>Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>or something like that.
>You can't change /that!/

Pi is the ratio of a circle's circumference to its radius - sequences
like the above are interesting but not meaningful in physical terms,
and at worst are just numerology. See http://xkcd.com/1047/ for lots
more.

The reason it's noted as 3 in _The Ragged Astronauts_ is to indicate
that "physics is different here in StoryWorld". Which clearly it would
have to be, what with the spacegoing wooden ships and whatnot.

Cheers - Jaimie
--
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HELO spammers.org
250 mail.sessile.org
MAIL FROM:<scum...@spammers.org>
550 you have four minutes to say goodbye to your family

[William F. Adams]

Actually, the approximation of the value of Pi in the Bible is quite
good _if one takes into account the thickness of the vessel_:

http://www.purplemath.com/modules/bibleval.htm

a fellow art school student made a full-size replica of the vessel in
question.

For me, one such error would be Jack Vance's characterization of
hickory as not being good for making (archery) bows out of (in his
Lyonesse Trilogy) --- it is a true bow wood and has been used as such
by pretty much every culture which had access to it.

William

[Anthony Nance]

Jaimie Vandenbergh <jai...@sometimes.sessile.org> wrote:
> On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie
> <rja.ca...@excite.com> wrote:
>
>>Pi is fundamental in mathematics, and it
>>can't have another value.
>>
>>Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>>or something like that.
>>You can't change /that!/
>
> Pi is the ratio of a circle's circumference to its radius - sequences
> like the above are interesting but not meaningful in physical terms,
> and at worst are just numerology. See http://xkcd.com/1047/ for lots
> more.

OT for the thread, but speaking of comics and pi, here's one
I saw yesterday:
http://www.gocomics.com/getfuzzy/2012/06/07

Tony

[Howard Brazee]

On Fri, 8 Jun 2012 05:49:19 -0700 (PDT), "William F. Adams"
<will...@aol.com> wrote:

>
>Actually, the approximation of the value of Pi in the Bible is quite
>good _if one takes into account the thickness of the vessel_:
>
>http://www.purplemath.com/modules/bibleval.htm
>
>a fellow art school student made a full-size replica of the vessel in
>question.

Certainly there is nothing wrong with the description that people base
that silly conclusion. (There are plenty of more effective examples
to show problems in the Bible). And also - pi = 3, to 1 significant
digit, and having the appropriate number of significant digits
matters.

--
"In no part of the constitution is more wisdom to be found,
than in the clause which confides the question of war or peace
to the legislature, and not to the executive department."

- James Madison

[Gary R. Schmidt]

On 8/06/2012 10:16 PM, Jaimie Vandenbergh wrote:
> On Thu, 07 Jun 2012 22:11:11 -0500, Dan Goodman<dsg...@iphouse.com>
> wrote:
>
>> In Connie Willis's short story "Just Like the Ones We Used to Know,"
>> it's snowing around Christmas in cities all over the world -- including
>> Honolulu. At a conference of experts, character says -"It never snows
>> in Hawaii."
>>
>> It does snow in Hawaii; though only at very high altitudes. An expert
>> would not say that.
>
> I'd be more worried about "all over the world" - including Melbourne
> and Auckland?

It *has* snowed in Melbourne, Victoria, Australia, on Christmas Day -
admittedly in the Dandenong Ranges, part of the hills that form the cup
valley sort-of thing that surrounds Melbourne, but they are usually
considered part of Greater Melbourne.

Cheers,
Gary B-)

--
When men talk to their friends, they insult each other.
They don't really mean it.
When women talk to their friends, they compliment each other.
They don't mean it either.

[Dorothy J Heydt]

In article <bf78ffda-bb54-4182...@googlegroups.com>,

Robert Carnegie <rja.ca...@excite.com> wrote:
>
>Pi is fundamental in mathematics, and it
>can't have another value.

In mathematics, yes. And for really close work. But for rough
estimates, pi is sufficiently approximate to 3. If you're an
engineer.
>
.... which it isn't), and at

>the end of Carl Sagan's _Contact_, the reader
>(but not yet the characters) is informed of
>the discovery in pi of a message from God.
>
>Well, God isn't allowed to change pi, either.

God *doesn't* change pi. He merely encoded it in such a way that
if you take it far enough, the numbers way south of the decimal
point draw a circle.

The astonishing thing is that Sagan is willing to write God into
a story at all.

>(Even though the bible also incorporates an
>apparent belief at the time that pi is 3 -
>at least for government work...)

It's an *approximation.* The context, whose _ipsissima verba_
I'm not going to look up at six-thirty in the morning, is that
while building the Temple, Solomon commissions some Phoenician
bronzeworkers to built a big vat (I don't know what its purpose
was), thirty "cubits" (~= ells, which ~= eighteen inches) across
and having thirty ornamental bosses around its perimeter, each a
cubit apart.

I betcha the Phoenician craftsmen knew the value of pi to some
improper fraction or another, but it wasn't really necessary in
the case of that project. Build the molds, cast the bronze for
the big vat, cast the bosses, attach them around the perimeter at
good-enough-for-government-work equal distance, deliver the thing
and collect their pay. Nowhere does the word "exactly" or
anything like it appear.

--
Dorothy J. Heydt
Vallejo, California
djheydt at gmail dot com
Should you wish to email me, you'd better use the gmail edress.
Kithrup's all spammy and hotmail's been hacked.
the thirty bosses,

[Joe Pfeiffer]

Jaimie Vandenbergh <jai...@sometimes.sessile.org> writes:

> On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie
> <rja.ca...@excite.com> wrote:
>
>>Pi is fundamental in mathematics, and it
>>can't have another value.
>>
>>Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>>or something like that.
>>You can't change /that!/
>
> Pi is the ratio of a circle's circumference to its radius - sequences
> like the above are interesting but not meaningful in physical terms,
> and at worst are just numerology. See http://xkcd.com/1047/ for lots
> more.

Ummm, no. the xkcd examples are approximations. The series above does
converge to exactly pi. And I'm not quite sure how a series that is
derived from trigonometric definitions can be "not meaningful" in
physical terms.

[Joseph Nebus]

In <M5Axo...@kithrup.com> djh...@kithrup.com (Dorothy J Heydt) writes:

>In article <bf78ffda-bb54-4182...@googlegroups.com>,
>Robert Carnegie <rja.ca...@excite.com> wrote:

>.... which it isn't), and at
>>the end of Carl Sagan's _Contact_, the reader
>>(but not yet the characters) is informed of
>>the discovery in pi of a message from God.
>>
>>Well, God isn't allowed to change pi, either.

>God *doesn't* change pi. He merely encoded it in such a way that
>if you take it far enough, the numbers way south of the decimal
>point draw a circle.

>The astonishing thing is that Sagan is willing to write God into
>a story at all.

Point of order. Sagan calls it up as the wormhole aliens giving
an example of something which fills them with wonder. And as candidates
for wonder go, it's a pretty good one, because a message hidden in pi
--- in the tiny handful of digits which can possibly ever be calculated
in the finite resources that non-God entities can access, I should point
out --- then:

1. Can't be deliberately put in there; logic does not work
that way.

2. Can't be just coincidence; probability does not work that
way.

3. Can't be hoaxed; monitoring does not work that way. (That
is, some super-peeping entity can't watch everything everyone does and
fiddle with the results so that the digits-of-pi calculation has the
message hidden in it; that's equivalent to solving the halting problem.)

4. Is there anyway.

And if that isn't something really, truly amazing, that this
thing which can't be deliberate, can't be accidental, and can't be faked,
is there anyway --- well, what *is* amazing?

--
http://nebusresearch.wordpress.com/ Joseph Nebus
Current Entry: A Third Thought About Falling http://wp.me/p1RYhY-gD
------------------------------------------------------------------------------

[Joseph Nebus]

In <M5Axo...@kithrup.com> djh...@kithrup.com (Dorothy J Heydt) writes:

>In article <bf78ffda-bb54-4182...@googlegroups.com>,
>Robert Carnegie <rja.ca...@excite.com> wrote:

>>(Even though the bible also incorporates an
>>apparent belief at the time that pi is 3 -
>>at least for government work...)

[ ... ]

>I betcha the Phoenician craftsmen knew the value of pi to some
>improper fraction or another, but it wasn't really necessary in
>the case of that project. Build the molds, cast the bronze for
>the big vat, cast the bosses, attach them around the perimeter at
>good-enough-for-government-work equal distance, deliver the thing
>and collect their pay. Nowhere does the word "exactly" or
>anything like it appear.

Yeah, but this (tired) bit is a fair jab to use against
Biblical Literalists, since if you're trying to argue that every word
in the Bible means precisely and exactly what it says, then this is a
pretty clear case where what it precisely says is wrong. If you're
willing to fiddle with the language and imagine an ``about'' or an
``approximately'' or accept that it's all an approximation, fine, but
the literalist rules exclude that, and that's why people go on way too
long about way too small a thing.

[Ernest Dotson]

On Jun 8, 5:38 am, Robert Carnegie <rja.carne...@excite.com> wrote:
> Well, God isn't allowed to change pi, either.
> (Even though the bible also incorporates an
> apparent belief at the time that pi is 3 -
> at least for government work...)

In fairness, one can reasonably argue that that was a significant
figure issue.

[Joseph Nebus]

In <83089ccf-8d4a-4a1d...@b21g2000yqn.googlegroups.com> Cryptoengineer <pete...@gmail.com> writes:

>I just finished listening to a reading of Silverberg's 'Hawksbill
>Station' on Escape Pod. I think I started it once, decades ago, but
>didn't finish it.

>The main plot McGuffin (this is revealed in the opening pages, so no
>spoiler warning), is a penal colony '1 billion years' in the past, to
>which the prisoners are irreversibly sent via a one-way time machine.

The absolutely most petty one that bugs me is from an alternate
history --- it must have appeared in _Alternate Presidents_ --- in which
Aaron Burr takes the Presidency in 1800. It's presented, in part, with
the 'nonfiction' documents surrounding his life as President, and one of
those bits concerns a bit of verse written about the War of 1807, when
the United States takes Canada from the British. It includes a rewrite
of 'The Battle of New Orleans' for the altered setting.

But the song was written by James Morris, best history teacher
ever, sometime between 1936 and 1958 (I can't find a more specific time).
It's not quite a ``dinosaurs never become extinct and Richard Nixon is
president'' problem but it's the same category.

(Even more petty, though, is that the tune Morris used *was* a
traditional tune commemorating Jackson's victory in New Orleans, so it
would be at least as plausible that someone in the alternate timeline
would compose something sounding like it, and someone else might make
words to fit it. I can't find where the tune originates without making
an effort, though, so forget that. Obviously if the tune predates 1800
then there's no objection to it surviving in the alternate timeline.)

[Dorothy J Heydt]

In article <jqt692$l1j$3...@reader1.panix.com>,

Joseph Nebus <nebusj-@-rpi-.edu> wrote:
>In <M5Axo...@kithrup.com> djh...@kithrup.com (Dorothy J Heydt) writes:
>
>>In article <bf78ffda-bb54-4182...@googlegroups.com>,
>>Robert Carnegie <rja.ca...@excite.com> wrote:
>
>>>(Even though the bible also incorporates an
>>>apparent belief at the time that pi is 3 -
>>>at least for government work...)
>
>[ ... ]
>>I betcha the Phoenician craftsmen knew the value of pi to some
>>improper fraction or another, but it wasn't really necessary in
>>the case of that project. Build the molds, cast the bronze for
>>the big vat, cast the bosses, attach them around the perimeter at
>>good-enough-for-government-work equal distance, deliver the thing
>>and collect their pay. Nowhere does the word "exactly" or
>>anything like it appear.
>
> Yeah, but this (tired) bit is a fair jab to use against
>Biblical Literalists, since if you're trying to argue that every word
>in the Bible means precisely and exactly what it says, then this is a
>pretty clear case where what it precisely says is wrong.

Let me recast that for you. If you claim that what the Bible
says (in translation, yet!) is precise, then you're wrong.

But it doesn't say "precisely." It's a translation of a text
written in Hebrew by somebody who didn't know enough math to
calculate even an approximate value of pi, but who saw the
finished product, was told that it was thirty cubits across (and
could eyeball that that figure was more or less right) and could
hold up his forearm between two of the bosses and observe that
that was about a cubit too. Remember the cubit is the length of
somebody's forearm. A translation, what's more, made by a team
of translators (if we're talking about the King James, as fundies
frequently do) who didn't know how to calculate the value of pi
either.

If you're
>willing to fiddle with the language and imagine an ``about'' or an
>``approximately'' or accept that it's all an approximation, fine, but
>the literalist rules exclude that, and that's why people go on way too
>long about way too small a thing.

And pointing this out is useful. I'm only saying that the text
as given *doesn't* say "exactly" or "precisely" or any synonym
I'm familiar with.

[Dorothy J Heydt]

In article <jqt7ho$3sp$1...@reader1.panix.com>,

Have you read any of Patricia Wrede's Frontier Magic books? Two
volumes in a projected trilogy are already out:

Thirteenth Child
Across the Great Barrier

The third volume, The Far West, comes out in August or thereabouts.

Alt-hist with magic, set in the United States of Columbia, the
Civil War took place in about 1840, some of the Presidents were
the same as in OTL, others different, and there's a magical
barrier running along the [Missisippi] River to keep out the
ferocious wildlife, both magical (steam dragons, Medusa lizards)
and non- (mammoths, terror birds), that inhabit the western half
of the continent. Lewis and Clarke set out on their expedition
and were never heard from again.

Here's a video clip about it. Notice the flag.

http://vimeo.com/22205398

[David Dyer-Bennet]

nebusj-@-rpi-.edu (Joseph Nebus) writes:

> In <M5Axo...@kithrup.com> djh...@kithrup.com (Dorothy J Heydt) writes:
>
>>In article <bf78ffda-bb54-4182...@googlegroups.com>,
>>Robert Carnegie <rja.ca...@excite.com> wrote:
>
>>.... which it isn't), and at
>>>the end of Carl Sagan's _Contact_, the reader
>>>(but not yet the characters) is informed of
>>>the discovery in pi of a message from God.
>>>
>>>Well, God isn't allowed to change pi, either.
>
>>God *doesn't* change pi. He merely encoded it in such a way that
>>if you take it far enough, the numbers way south of the decimal
>>point draw a circle.
>
>>The astonishing thing is that Sagan is willing to write God into
>>a story at all.
>
> Point of order. Sagan calls it up as the wormhole aliens giving
> an example of something which fills them with wonder. And as candidates
> for wonder go, it's a pretty good one, because a message hidden in pi
> --- in the tiny handful of digits which can possibly ever be calculated
> in the finite resources that non-God entities can access, I should point
> out --- then:
>
> 1. Can't be deliberately put in there; logic does not work
> that way.

Not convincing.

> 2. Can't be just coincidence; probability does not work that
> way.

Actively wrong, so far as I can see.
--
David Dyer-Bennet, dd...@dd-b.net; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info

[Cryptoengineer]

That, actually, is excusable. The date for the Big Bang was tied down
relatively recently. Silverberg, otoh, should have known that there
was no large multicellular life, let alone trilobites, 1B YA.

I'll excuse his not knowing that oxygen levels were so low 1B YA that
people would immediately asphyxiate.

pt

[Michael Stemper]

In article <0ar3t7ttq6v4umd4o...@4ax.com>, Jaimie Vandenbergh <jai...@sometimes.sessile.org> writes:
>On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie <rja.ca...@excite.com> wrote:

>>Pi is fundamental in mathematics, and it
>>can't have another value.
>>
>>Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>>or something like that.
>>You can't change /that!/
>
>Pi is the ratio of a circle's circumference to its radius -

That's backwards. The right way to say that is "In Euclidean space, the
ratio of a circle's circumference to its diameter is Pi."

> sequences
>like the above are interesting but not meaningful in physical terms,

Although math can sometimes be applied to physical phenomena, physical
terms don't control math.

>The reason it's noted as 3 in _The Ragged Astronauts_

The ratio of the circumference of a circle to its diameter might have
been 3, but that doesn't affect the value of Pi.

> is to indicate
>that "physics is different here in StoryWorld".

Question to any mathematicians who are lurking, especially geometers:

Is it possible to have a space in which C/d is uniformly 3? Would you
need a different metric function, or could a space be shaped this way?

(I'm trying to figure out what the definition of "length of the
circumference in the taxicab metric would be, and failing.)

--
Michael F. Stemper
#include <Standard_Disclaimer>
Life's too important to take seriously.

[Michael Stemper]

In article <ylfkhaul...@dd-b.net>, David Dyer-Bennet <dd...@dd-b.net> writes:
>nebusj-@-rpi-.edu (Joseph Nebus) writes:
>> In <M5Axo...@kithrup.com> djh...@kithrup.com (Dorothy J Heydt) writes:

[_Contact_]

>>>God *doesn't* change pi. He merely encoded it in such a way that
>>>if you take it far enough, the numbers way south of the decimal
>>>point draw a circle.
>>
>>>The astonishing thing is that Sagan is willing to write God into
>>>a story at all.
>>
>> Point of order. Sagan calls it up as the wormhole aliens giving
>> an example of something which fills them with wonder. And as candidates
>> for wonder go, it's a pretty good one, because a message hidden in pi
>> --- in the tiny handful of digits which can possibly ever be calculated
>> in the finite resources that non-God entities can access, I should point
>> out --- then:
>>
>> 1. Can't be deliberately put in there; logic does not work
>> that way.
>
>Not convincing.
>
>> 2. Can't be just coincidence; probability does not work that
>> way.
>
>Actively wrong, so far as I can see.

If Pi is actually normal (base ten), wouldn't its decimal representation
have infinitely many pictures of circles? And trailers for the real Star
Wars prequel movies?

[Sea Wasp (Ryk E. Spoor)]

On 6/8/12 1:15 PM, Michael Stemper wrote:
> In article<0ar3t7ttq6v4umd4o...@4ax.com>, Jaimie Vandenbergh<jai...@sometimes.sessile.org> writes:
>> On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie<rja.ca...@excite.com> wrote:
>
>>> Pi is fundamental in mathematics, and it
>>> can't have another value.
>>>
>>> Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>>> or something like that.
>>> You can't change /that!/
>>
>> Pi is the ratio of a circle's circumference to its radius -
>
> That's backwards.

That's so for formal mathematics, but that's not the way it's taught in
all the schools I've been in or have had any direct experience of (below
college level): pi is defined for the class as the ratio of diameter to
circumference, and all the mathematics are described as ways to get more
precise values for pi than by just taking a tape measure out.

So whenever this comes up, the fact is that the groups of people
talking are arguing using two different definitions, and BOTH groups
think the other guy's definition is the secondary one.



--
Sea Wasp
/^\
;;;
Website: http://www.grandcentralarena.com Blog:
http://seawasp.livejournal.com

[Jaimie Vandenbergh]

Looks like the membership of the maths club is more popular with the
nitpickers here!

Cheers - Jaimie
--
Sent from my VAX 11/780

[Dan Goodman]

On 06/08/2012 07:16 AM, Jaimie Vandenbergh wrote:
> On Thu, 07 Jun 2012 22:11:11 -0500, Dan Goodman<dsg...@iphouse.com>
> wrote:
>
>> In Connie Willis's short story "Just Like the Ones We Used to Know,"
>> it's snowing around Christmas in cities all over the world -- including
>> Honolulu. At a conference of experts, character says -"It never snows
>> in Hawaii."
>>
>> It does snow in Hawaii; though only at very high altitudes. An expert
>> would not say that.
>
> I'd be more worried about "all over the world" - including Melbourne
> and Auckland?

Yes. The story is fantasy.

--
Dan Goodman

[Jaimie Vandenbergh]

On Fri, 8 Jun 2012 17:15:40 +0000 (UTC), mste...@walkabout.empros.com
(Michael Stemper) wrote:

>In article <0ar3t7ttq6v4umd4o...@4ax.com>, Jaimie Vandenbergh <jai...@sometimes.sessile.org> writes:
>>
>> sequences
>>like the above are interesting but not meaningful in physical terms,
>
>Although math can sometimes be applied to physical phenomena, physical
>terms don't control math.

Yes? We were talking about pi being 3 in _The Ragged Astronauts_, and
thus an empirical physical observation. You're going at it from the
maths side, which is inappropriate since in Shaw's storyworld _our_ pi
at 3.141etc would not be at all connected to circles.

>>The reason it's noted as 3 in _The Ragged Astronauts_
>
>The ratio of the circumference of a circle to its diameter might have
>been 3, but that doesn't affect the value of Pi.

See, you even say that but aren't catching what that means:

>> is to indicate
>>that "physics is different here in StoryWorld".

Physics, not maths.

>Question to any mathematicians who are lurking, especially geometers:
>
>Is it possible to have a space in which C/d is uniformly 3? Would you
>need a different metric function, or could a space be shaped this way?

I couldn't see any way, but I'm a simpleton in geometry these days.

Cheers - Jaimie
--
The glass, being topologically equivalent to a finite flat sheet, can be
neither "full" nor "empty" : it may or may not have some beer balanced
on it. - Oldbloke, urs

[Jaimie Vandenbergh]

On Fri, 08 Jun 2012 12:38:31 -0500, Dan Goodman <dsg...@iphouse.com>

wrote:

>On 06/08/2012 07:16 AM, Jaimie Vandenbergh wrote:
>> On Thu, 07 Jun 2012 22:11:11 -0500, Dan Goodman<dsg...@iphouse.com>
>> wrote:
>>
>>> In Connie Willis's short story "Just Like the Ones We Used to Know,"
>>> it's snowing around Christmas in cities all over the world -- including
>>> Honolulu. At a conference of experts, character says -"It never snows
>>> in Hawaii."
>>>
>>> It does snow in Hawaii; though only at very high altitudes. An expert
>>> would not say that.
>>
>> I'd be more worried about "all over the world" - including Melbourne
>> and Auckland?
>
>Yes. The story is fantasy.

That's okay then - it wouldn't trip my WSOD in that case, because
magic.

Cheers - Jaimie
--
#include "clue.h"

[Ted Nolan <tednolan>]

In article <bf78ffda-bb54-4182...@googlegroups.com>,
Robert Carnegie <rja.ca...@excite.com> wrote:

Presumably He couldn't change the message and keep the universe the same
afterwards, but I don't see why the fundamental constants of the universe
couldn't be set once to desired values at boot-time.

There's a funny moment in the Liaden book _Crystal Dragon_. The heroes
are transporting rag-tag shiploads of reluctant refugee/colonists
out of a Universe where space is being decrystalized by hostiles and being
guided by a dying genius mathematician. At one point he says something
like "Wait! We have to offset all our calibrations by as close to this
as you can get '3.1415926...'" and it's clear the number means nothing
to any of the crew.
--
------
columbiaclosings.com
What's not in Columbia anymore..

[Anthony Nance]

Michael Stemper <mste...@walkabout.empros.com> wrote:
> In article <0ar3t7ttq6v4umd4o...@4ax.com>, Jaimie Vandenbergh <jai...@sometimes.sessile.org> writes:
>>On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie <rja.ca...@excite.com> wrote:
>
>>>Pi is fundamental in mathematics, and it
>>>can't have another value.
>>>
>>>Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>>>or something like that.
>>>You can't change /that!/
>>
>>Pi is the ratio of a circle's circumference to its radius -
>
> That's backwards. The right way to say that is "In Euclidean space, the
> ratio of a circle's circumference to its diameter is Pi."
>
>> sequences
>>like the above are interesting but not meaningful in physical terms,
>
> Although math can sometimes be applied to physical phenomena, physical
> terms don't control math.
>
>>The reason it's noted as 3 in _The Ragged Astronauts_
>
> The ratio of the circumference of a circle to its diameter might have
> been 3, but that doesn't affect the value of Pi.
>
>> is to indicate
>>that "physics is different here in StoryWorld".
>
> Question to any mathematicians who are lurking, especially geometers:
>
> Is it possible to have a space in which C/d is uniformly 3?

It's been a good long while, but I don't think so. At least, iirc,
only in elliptical geometry is C/d < pi , and in elliptical geometry,
C = 2*pi*sin(r) . Since d = 2*r , we're not going to be able
to get a constant value for C/d .

I'm very happy to be corrected and/or learn more, of course.
- Tony

[david.sh...@ymail.com]

On Jun 8, 1:15 pm, mstem...@walkabout.empros.com (Michael Stemper)
wrote:

> Is it possible to have a space in which C/d is uniformly 3? Would you
> need a different metric function, or could a space be shaped this way?
>
> (I'm trying to figure out what the definition of "length of the
> circumference in the taxicab metric would be, and failing.)

Not exactly a mathematician here, but ...

A metric function should be able to be characterized by
its unit ball, B, the set of points at distance 1 from a center.
I think this needs to be centrally symmetric and convex.

A curve has length, according to this metric, equal to
the limit as r goes to 0 of r times the number of balls of radius
r/2 required to cover the curve. ( A generalization of this
formula applies to fractals, where we have to raise one
of the occurances of r to some power to get a non-zero,
finite limit. )

If I understand correctly, the taxicab metric between points (a,b) and
(c,d)
is |a-c| + |b-d|. The corresponding unit ball is a square with sides
of Euclidean length square_root(2), rotated by 45 degrees. That is,
the set of points (x,y) so that |x|+|y| <= 1. According to my
definition of the length of a curve, the circumference of this
unit ball has length 8, and the diameter is 2. So C/d = 4.

If we choose the metric whose unit ball is a regular hexagon,
each of the six sides has length 1, so C=6, d = 2, and C/d=3.

Based on this tiny sample, I would conjecture that, for unit balls
which are regular n-gons, C/d is greater than pi if n = 0 modulo 4,
and C/d is less than pi if n = 2 modulo 4.

(n odd gives non-centrally symmetric polygons, which are not allowed.)

- David

[Joseph Nebus]

If pi is normal --- which is the way I'd bet too --- then, yes,
its decimal representation --- in fact, its representation in any base
--- is going to have every conceivable message encoded in every possible
way within it. Now, kindly pay attention.

Those messages will be somewhere within the infinitely many
digits of pi. However, no entity which exists will ever, *ever*, have
access to all the infinitely many digits of pi. This is important.
No matter how long we spend looking, we will have only a finite subset
of pi's digits.

The chance of *any* message being *somewhere* in Pi is likely
1. But the chance of *any* message being *somewhere* in the *finite
sample of digits of Pi we will ever be able to access* is much less
than 1. The longer the message is, the closer that probability gets
to zero.

Please pay attention to that. The claim about probability is
not that it is impossible the message is in Pi, but that it is very
unlikely to be in the truncated version of Pi that we will ever be able
to work with. If you don't believe me, then, take the ASCII codes for
any line of Shakespeare you like and go looking for them on any page
listing the first brazillion digits of Pi. See how many phrases you
have to go to, and how short they have to get, before you find them.
*That* is the probability of interest.

And note that according to _Contact_, this improbably unlikely
message is found not just in one base, or two bases, but in *every*
base representation for which it's sought. So not only is it an
incredibly unlikely event, but, that improbability is raised to an
incredible power. The probability of the subset of digits in Pi that
can be accessed, in *every* base, having this circle encoded in it, is
arbitrarily close to zero. And if you don't like how close to zero it
is, throw in the probability that this message is in Accessible Pi in
*another* base, and the chance that it's there collapses below whatever
threshold for 'could possibly exist' you have.

[Anthony Nance]

If anyone ever proves pi is normal, then it also contains the equivalent
of every finite message, including "ip otni dedoc gnieb egassem emos fo
aedi eht desu nagaS eveileb t'nac I". [1]

Tony
[1] I started to respond to this when I realized I had read something
like this before. Turns out it was me, saying it here in Feb 2008,
and I am guilty of quoting myself above. Mea culpa.

[david.sh...@ymail.com]

On Jun 8, 2:20 pm, david.shallcr...@ymail.com wrote:
>
> A curve has length, according to this metric, equal to
> the limit as r goes to 0 of r times the number of balls of radius
> r/2 required to cover the curve.  ( A generalization of this
> formula applies to fractals, where we have to raise one
> of the occurances of r to some power to get a non-zero,
> finite limit. )

I should add that you are allowed translations of the balls,
but not rotations. That is, you can slide the balls around,
but must keep their orientations fixed.

[James Silverton]

By the way, the ratio of circumference to radius is 2PI
--
Jim Silverton (Potomac, MD)

Extraneous "not" in Reply To.

[lal_truckee]

On 6/7/12 7:55 PM, Cryptoengineer wrote:
> The problem is that there are trilobites and brachiopods, creatures
> that didn't exist until a bit more than 500 million years ago.

Did they exist in 1 billion BCE in 1967?

[James Nicoll]

In article <jqtjdr$bm6$1...@dont-email.me>,

I have this dim memory that Silverberg had a major revision of the geological
time table as a passing plot point in that book.
--
http://www.livejournal.com/users/james_nicoll
http://www.cafepress.com/jdnicoll (For all your "The problem with
defending the English language [...]" T-shirt, cup and tote-bag needs)

[lal_truckee]

On 6/8/12 10:15 AM, Michael Stemper wrote:

> Is it possible to have a space in which C/d is uniformly 3?

Flatland on a sphere.

[lal_truckee]

On 6/8/12 11:04 AM, Ted Nolan <tednolan> wrote:
> Presumably He couldn't change the message and keep the universe the same
> afterwards, but I don't see why the fundamental constants of the universe
> couldn't be set once to desired values at boot-time.

Pi (and e) are not "fundamental constants of the universe" in the way
you're thinking. They exist independent of the universe.

[Marcus L. Rowland]

In message
<83089ccf-8d4a-4a1d...@b21g2000yqn.googlegroups.com>,

Cryptoengineer <pete...@gmail.com> writes
>I just finished listening to a reading of Silverberg's 'Hawksbill
>Station' on Escape Pod. I think I started it once, decades ago, but
>didn't finish it.
>
>The main plot McGuffin (this is revealed in the opening pages, so no
>spoiler warning), is a penal colony '1 billion years' in the past, to
>which the prisoners are irreversibly sent via a one-way time machine.
>

>The problem is that there are trilobites and brachiopods, creatures
>that didn't exist until a bit more than 500 million years ago.
>

>Silverberg could have said '500M YA', and absolutely nothing in the
>story would change. But everytime I heard 'billion', it bugged me. A
>lot.
>
>pt

I've mentioned this here before, I think, but it's a good example of how
to wreck WSOD.

There's a scene in Iain M. Banks' _Surface Detail_ in which a character
chucks a gold coin into a pool of mercury, and it bobs back up to the
surface gleaming its pure gold colour.

Except that many years ago I accidentally got mercury on my gold watch,
and it instantly did what mercury always does in contact with gold -
reacts with the gold to form a grey and not particularly shiny gold /
mercury amalgam, similar to the stuff some tooth fillings are made of.
So I immediately knew that there was something wrong.

What I missed, until someone pointed it out in RASFW, is that gold is
DENSER than mercury, so it should have sunk and stayed sunk anyway.

Part of the trouble was that the book is in part about virtual reality,
so I kept expecting the pool to turn out to be in a virtual setting. And
it kept on being stubbornly in the real world of the book.

I asked Iain about this a couple of years ago, it turns out he didn't
realise that mercury is less dense because it has a higher atomic
number, which I suppose is an easy mistake to make.

There was a weird one on Jo Walton's old web site, a description of
timekeeping in the world of her fantasy novel _Tooth and Claw_ which
unfortunately fell down if you looked at it too closely; and since I was
writing the RPG I did have to look. If taken as written it made the day
about 67 hours and the year about 1.5 earth years, and seasonal extremes
that would have been more or less intolerable for the humans that also
exist in that world, let alone cold-blooded dragons.

I ended up writing a spreadsheet template in which you could vary all of
the factors mentioned in the description; we ended up re-defining the
way their second was measured to halve its duration, which made the day
33 hours 20 minutes and the year 0.76 Earth years - still a bit weird,
but a lot less extreme than the original.
--
Marcus L. Rowland www.forgottenfutures.com
www.forgottenfutures.org
www.forgottenfutures.co.uk
Forgotten Futures - The Scientific Romance Role Playing Game
Diana: Warrior Princess & Elvis: The Legendary Tours
The Original Flatland Role Playing Game

[Michael Stemper]

I don't think that's true. Let's assume a perfectly spherical Earth, and
draw the loci of all points at varying distances from the North Pole.

As long as our radius is only a few feet or meters, C/d is going to be
so close to Pi as to not make no never mind.

When we use the distance from the North Pole to Minneapolis (45 N) as
our radius, we get a diameter of E/4 (where E is the length of the equator),
but a circumference of E/sqrt(2), giving C/d = 2*sqrt(2). [1]

When we use the distance from the North Pole to the Equator as our
radius, we get a diameter of E/2, and a circumference of E, giving
C/d = 2.

As the radius increases from E/4 towards E/2, C/d shrinks towards zero,
because the circles get smaller as the radius and diameter increase.


[1] Somebody please confirm or correct this one.

[David Dyer-Bennet]

Yes.

But we don't know if it is.

For that matter, lower bars than "normal" still leave that at least
possible.

What's going on in my head is wondering just how the digits of the
decimal representation of an irrational number compare to *random*
sequences. Clearly the digits of pi are NOT random in at least one
sense -- there's the actual value of pi, and every other sequence of
digits. But my out-dated intuition is saying they probably *do* look
like random sequences in most ways; and to the extent that's true, yeah,
we'd expect to find any finite sequence in there somewhere.

[Konrad Gaertner]

Joseph Nebus wrote:
>
> The chance of *any* message being *somewhere* in Pi is likely
> 1. But the chance of *any* message being *somewhere* in the *finite
> sample of digits of Pi we will ever be able to access* is much less
> than 1. The longer the message is, the closer that probability gets
> to zero.

You realise this sounds exactly like creationist arguments against
spontanious creation of life.

> Please pay attention to that. The claim about probability is
> not that it is impossible the message is in Pi, but that it is very
> unlikely to be in the truncated version of Pi that we will ever be able
> to work with. If you don't believe me, then, take the ASCII codes for
> any line of Shakespeare you like and go looking for them on any page
> listing the first brazillion digits of Pi. See how many phrases you
> have to go to, and how short they have to get, before you find them.
> *That* is the probability of interest.

One of the previous times we had this argument, someone linked to a
website that would search for arbitrary strings in the base-256
expansion of pi. It didn't have to look too far to find my name.

> And note that according to _Contact_, this improbably unlikely
> message is found not just in one base, or two bases, but in *every*
> base representation for which it's sought.

I haven't read the book, but from past discussions I thought it was
only found in base-11.


--
Konrad Gaertner - - - - - - - - - - - - email: kgae...@tx.rr.com
http://kgbooklog.livejournal.com/
"I don't mind hidden depths but I insist that there be a surface."
-- James Nicoll

[David Dyer-Bennet]

nebusj-@-rpi-.edu (Joseph Nebus) writes:

> In <jqtc57$kc0$3...@dont-email.me> mste...@walkabout.empros.com (Michael Stemper) writes:
>
>>In article <ylfkhaul...@dd-b.net>, David Dyer-Bennet <dd...@dd-b.net> writes:
>>>nebusj-@-rpi-.edu (Joseph Nebus) writes:
>
>>>> 2. Can't be just coincidence; probability does not work that
>>>> way.
>>>
>>>Actively wrong, so far as I can see.
>
>>If Pi is actually normal (base ten), wouldn't its decimal representation
>>have infinitely many pictures of circles? And trailers for the real Star
>>Wars prequel movies?
>
> If pi is normal --- which is the way I'd bet too --- then, yes,
> its decimal representation --- in fact, its representation in any base
> --- is going to have every conceivable message encoded in every possible
> way within it. Now, kindly pay attention.

I don't believe being normal in one base implies being normal in all
others; there's a term, "absolutely normal", for numbers that are normal
in all bases. (This may, however, be one of those cases where we simply
haven't been able to prove it yet.)

> Those messages will be somewhere within the infinitely many
> digits of pi. However, no entity which exists will ever, *ever*, have
> access to all the infinitely many digits of pi. This is important.
> No matter how long we spend looking, we will have only a finite subset
> of pi's digits.

Very true.

> The chance of *any* message being *somewhere* in Pi is likely
> 1. But the chance of *any* message being *somewhere* in the *finite
> sample of digits of Pi we will ever be able to access* is much less
> than 1. The longer the message is, the closer that probability gets
> to zero.

Also very true.

As an approximation, consider the monkeys with typewriters,
vs. Shakespeare (the digits of pi are not, of course, random, so it's
not an exat match). We can calculate the number of characters they'd
have to produce to give a 50:50 chance of one complete Shakespeare play
being in them somewhere, and it is...large.

> Please pay attention to that. The claim about probability is
> not that it is impossible the message is in Pi, but that it is very
> unlikely to be in the truncated version of Pi that we will ever be able
> to work with. If you don't believe me, then, take the ASCII codes for
> any line of Shakespeare you like and go looking for them on any page
> listing the first brazillion digits of Pi. See how many phrases you
> have to go to, and how short they have to get, before you find them.
> *That* is the probability of interest.

No monkeys, but I see you also thought of Shakespeare.

> And note that according to _Contact_, this improbably unlikely
> message is found not just in one base, or two bases, but in *every*
> base representation for which it's sought. So not only is it an
> incredibly unlikely event, but, that improbability is raised to an
> incredible power. The probability of the subset of digits in Pi that
> can be accessed, in *every* base, having this circle encoded in it, is
> arbitrarily close to zero. And if you don't like how close to zero it
> is, throw in the probability that this message is in Accessible Pi in
> *another* base, and the chance that it's there collapses below whatever
> threshold for 'could possibly exist' you have.

Yeah, but...divine power. Omniscience. Omnipotence.

[David Dyer-Bennet]

Jaimie Vandenbergh <jai...@sometimes.sessile.org> writes:

> On Fri, 08 Jun 2012 13:23:17 -0400, "Sea Wasp (Ryk E. Spoor)"
> <sea...@sgeinc.invalid.com> wrote:
>
>>On 6/8/12 1:15 PM, Michael Stemper wrote:
>>> In article<0ar3t7ttq6v4umd4o...@4ax.com>, Jaimie Vandenbergh<jai...@sometimes.sessile.org> writes:
>>>> On Fri, 8 Jun 2012 03:38:55 -0700 (PDT), Robert Carnegie<rja.ca...@excite.com> wrote:
>>>
>>>>> Pi is fundamental in mathematics, and it
>>>>> can't have another value.
>>>>>
>>>>> Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
>>>>> or something like that.
>>>>> You can't change /that!/
>>>>
>>>> Pi is the ratio of a circle's circumference to its radius -
>>>
>>> That's backwards.
>>
>> That's so for formal mathematics, but that's not the way it's taught in
>>all the schools I've been in or have had any direct experience of (below
>>college level): pi is defined for the class as the ratio of diameter to
>>circumference, and all the mathematics are described as ways to get more
>>precise values for pi than by just taking a tape measure out.
>>
>> So whenever this comes up, the fact is that the groups of people
>>talking are arguing using two different definitions, and BOTH groups
>>think the other guy's definition is the secondary one.
>
> Looks like the membership of the maths club is more popular with the
> nitpickers here!

Well, duh! :-)

And, historically, the physical definition came first, yes? The
mathematical connection to other things, and the independent
mathematical definition, arose later.

[Robert Carnegie]

On Friday, June 8, 2012 7:22:29 PM UTC+1, Anthony Nance wrote:

> Michael Stemper <mste...@walkabout.empros.com> wrote:
> > If Pi is actually normal (base ten), wouldn't its decimal representation
> > have infinitely many pictures of circles? And trailers for the real Star
> > Wars prequel movies?
>
>
> If anyone ever proves pi is normal, then it also contains the equivalent
> of every finite message, including "ip otni dedoc gnieb egassem emos fo
> aedi eht desu nagaS eveileb t'nac I". [1]
>
> Tony
> [1] I started to respond to this when I realized I had read something
> like this before. Turns out it was me, saying it here in Feb 2008,
> and I am guilty of quoting myself above. Mea culpa.

Google is your wife.

[Robert Carnegie]

It's the same pi, so it doesn't matter.

In non-Euclidean geometry, you may have
"circles" whose circumference-to-diameter
ratio is always less than pi, or is always
more than pi, but pi typically will be
the limit in one direction.

Supposedly, God doesn't lie, so he can't lie
to us about or in the value of pi. The only
thing that he can choose is how many fingers
we have, which is the basis of our counting up
to ten, maybe.

And anyway the Sagan message (which is
fictional) is "O". I'm willing to
contemplate "The Lord's Prayer", but I
draw the line at a single letter.

Meanwhile, another mathematical wonder
number, e, is approximately 2.71828182846.
Notice anything there? God being a little
more obvious this time, Robert jests.

[Robert Carnegie]

On Friday, June 8, 2012 3:02:59 PM UTC+1, Dorothy J Heydt wrote:
> In article <bf78ffda-bb54-4182...@googlegroups.com>,

> Robert Carnegie <rja.ca...@excite.com> wrote:
> >
> >Pi is fundamental in mathematics, and it
> >can't have another value.
>

> In mathematics, yes. And for really close work. But for rough
> estimates, pi is sufficiently approximate to 3. If you're an
> engineer.
> >
> .... which it isn't), and at

> >the end of Carl Sagan's _Contact_, the reader
> >(but not yet the characters) is informed of
> >the discovery in pi of a message from God.
> >
> >Well, God isn't allowed to change pi, either.
>

> God *doesn't* change pi. He merely encoded it in such a way that
> if you take it far enough, the numbers way south of the decimal
> point draw a circle.
>
> The astonishing thing is that Sagan is willing to write God into
> a story at all.
>

> >(Even though the bible also incorporates an
> >apparent belief at the time that pi is 3 -
> >at least for government work...)
>

> It's an *approximation.* The context, whose _ipsissima verba_
> I'm not going to look up at six-thirty in the morning, is that
> while building the Temple, Solomon commissions some Phoenician
> bronzeworkers to built a big vat (I don't know what its purpose
> was), thirty "cubits" (~= ells, which ~= eighteen inches) across
> and having thirty ornamental bosses around its perimeter, each a
> cubit apart.
>
> I betcha the Phoenician craftsmen knew the value of pi to some
> improper fraction or another, but it wasn't really necessary in
> the case of that project. Build the molds, cast the bronze for
> the big vat, cast the bosses, attach them around the perimeter at
> good-enough-for-government-work equal distance, deliver the thing
> and collect their pay. Nowhere does the word "exactly" or
> anything like it appear.

Nor "Thirty-one-and-a-half". I don't want to
sound obsessed with this, the damn thing may
have been oval, but on the other hand I don't
think that temples and such are usually built
"close enough for government work".

All of the numbers of things in the bible,
such as Hittites, are round numbers. And are
probably made up. New Testament too, you don't
get Jesus feeding the 5,013 do you.
(Some tellings and translations do say "about
5,000". Some do not.)

[Howard Brazee]

On Fri, 8 Jun 2012 16:12:50 -0700 (PDT), Robert Carnegie
<rja.ca...@excite.com> wrote:

>Supposedly, God doesn't lie, so he can't lie
>to us about or in the value of pi. The only
>thing that he can choose is how many fingers
>we have, which is the basis of our counting up
>to ten, maybe.

Does the Bible say He doesn't lie? Does it say He can't lie?

--
"In no part of the constitution is more wisdom to be found,
than in the clause which confides the question of war or peace
to the legislature, and not to the executive department."

- James Madison

[Robert Carnegie]

On Saturday, June 9, 2012 12:35:08 AM UTC+1, Howard Brazee wrote:
> On Fri, 8 Jun 2012 16:12:50 -0700 (PDT), Robert Carnegie
> <rja.ca...@excite.com> wrote:
>
> >Supposedly, God doesn't lie, so he can't lie
> >to us about or in the value of pi. The only
> >thing that he can choose is how many fingers
> >we have, which is the basis of our counting up
> >to ten, maybe.
>
> Does the Bible say He doesn't lie? Does it
> say He can't lie?

It does. But I figured it made more sense to
say that he chooses not to lie.

[Robert Bannister]

On 8/06/12 11:11 AM, Dan Goodman wrote:

> On 06/07/2012 09:55 PM, Cryptoengineer wrote:
>> I just finished listening to a reading of Silverberg's 'Hawksbill
>> Station' on Escape Pod. I think I started it once, decades ago, but
>> didn't finish it.
>>
>> The main plot McGuffin (this is revealed in the opening pages, so no
>> spoiler warning), is a penal colony '1 billion years' in the past, to
>> which the prisoners are irreversibly sent via a one-way time machine.
>>
>> The problem is that there are trilobites and brachiopods, creatures
>> that didn't exist until a bit more than 500 million years ago.
>>
>> Silverberg could have said '500M YA', and absolutely nothing in the
>> story would change. But everytime I heard 'billion', it bugged me. A
>> lot.
>

> In Connie Willis's short story "Just Like the Ones We Used to Know,"
> it's snowing around Christmas in cities all over the world -- including
> Honolulu. At a conference of experts, character says -"It never snows in
> Hawaii."
>
> It does snow in Hawaii; though only at very high altitudes. An expert
> would not say that.

An expert wouldn't say "all over the world" either, unless the world has
suddenly lost its southern hemisphere and most of the tropics.


--
Robert Bannister

[Dan Goodman]

In the story, it IS snowing in cities ALL OVER THE WORLD.

It's a fantasy story.


--
Dan Goodman

[David DeLaney]

Jaimie Vandenbergh <jai...@sometimes.sessile.org> wrote:
>Robert Carnegie <rja.ca...@excite.com> wrote:
>>Pi is fundamental in mathematics, and it can't have another value.
>>

>>Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ... or something like that.
>>You can't change /that!/
>

>Pi is the ratio of a circle's circumference to its radius - sequences
>like the above are interesting but not meaningful in physical terms,
>and at worst are just numerology. See http://xkcd.com/1047/ for lots more.

Right. We don't know WHY mathematics fits the physical universe so closely
(to such a degree that we keep finding instances in physics where purely
theoretical pieces of math are suddenly useful and accurate). We just know
it does. It's certainly possible for there to be universes where circumference
over diameter was three, though the first thought of "a positively-curved
space of uniform radius" doesn't work.

>The reason it's noted as 3 in _The Ragged Astronauts_ is to indicate
>that "physics is different here in StoryWorld". Which clearly it would
>have to be, what with the spacegoing wooden ships and whatnot.

Dave "see also Melissa Scott: 5/12 of Heaven etc." DeLaney
--
\/David DeLaney posting from d...@vic.com "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.

[David DeLaney]

Michael Stemper <mste...@walkabout.empros.com> wrote:
>(I'm trying to figure out what the definition of "length of the
>circumference in the taxicab metric would be, and failing.)

That's easy, really - in taxicab pi equals 4, because circles are effectively
square.

Dave "no, it makes sense in context, I _promise_" DeLaney

[David DeLaney]

You'd think so maybe, but look again: on a sphere, pi changes in value as
your circle gets bigger or smaller. The largest circle on a sphere has pi = 2,
and the limit as they get infinitesimal is back up to our \pi again.

Dave

[David DeLaney]

Joseph Nebus <nebusj-@-rpi-.edu> wrote:
> Those messages will be somewhere within the infinitely many
>digits of pi. However, no entity which exists will ever, *ever*, have
>access to all the infinitely many digits of pi. This is important.
>No matter how long we spend looking, we will have only a finite subset
>of pi's digits.

Psst: no _finite_ entity which exists.

(ObSF: Rudy Rucker, _White Light_.)

[Robert A. Woodward]

In article <tdb9a9-...@paranoia.mcleod-schmidt.id.au>,
"Gary R. Schmidt" <grsc...@acm.org> wrote:

> On 8/06/2012 10:16 PM, Jaimie Vandenbergh wrote:

> > On Thu, 07 Jun 2012 22:11:11 -0500, Dan Goodman<dsg...@iphouse.com>
> > wrote:
> >
> >> In Connie Willis's short story "Just Like the Ones We Used to Know,"
> >> it's snowing around Christmas in cities all over the world -- including
> >> Honolulu. At a conference of experts, character says -"It never snows
> >> in Hawaii."
> >>
> >> It does snow in Hawaii; though only at very high altitudes. An expert
> >> would not say that.
> >

> > I'd be more worried about "all over the world" - including Melbourne
> > and Auckland?
>
> It *has* snowed in Melbourne, Victoria, Australia, on Christmas Day -
> admittedly in the Dandenong Ranges, part of the hills that form the cup
> valley sort-of thing that surrounds Melbourne, but they are usually
> considered part of Greater Melbourne.
>

I have seen snow in August, in Stratford, Ontario. Wasn't very much
snow and it melted very quickly, but it was August, at less than
400 meters elevation and at less than 45 degrees latitude.

--
Robert Woodward <robe...@drizzle.com>
<http://www.drizzle.com/~robertaw>

[tphile2]

On Jun 7, 9:55 pm, Cryptoengineer <petert...@gmail.com> wrote:
> I just finished listening to a reading of Silverberg's 'Hawksbill
> Station' on Escape Pod. I think I started it once, decades ago, but
> didn't finish it.
>
> The main plot McGuffin (this is revealed in the opening pages, so no
> spoiler warning), is a penal colony '1 billion years' in the past, to
> which the prisoners are irreversibly sent via a one-way time machine.
>
> The problem is that there are trilobites and brachiopods, creatures
> that didn't exist until a bit more than 500 million years ago.
>
> Silverberg could have said '500M YA', and absolutely nothing in the
> story would change. But everytime I heard 'billion', it bugged me. A
> lot.
>

> pt

I had the same problem watching Ridley Scotts new movie Prometheus.
When you are astronauts making first contact on an alien planet and
alien structure with everything alien and unknown, you DON'T take off
your space helmet regardless if the air is breathable. You have no
idea what you are getting exposed too. Regardless if your suit and
defenses are ineffective.etc. Also something cute can be very
deadly. Also the bridge and everything else should be manned and
watched around the clock. and thats just for starters.

[ppint. at pplay]

- hi; in article, <slrnjt5bu...@gatekeeper.vic.com>,
d...@gatekeeper.vic.com "David DeLaney" observed:

> lal_truckee <lal_t...@yahoo.com> wrote:
>> Michael Stemper wrote:

>>>Is it possible to have a space in which C/d is uniformly 3?
>>
>>Flatland on a sphere.
>
>You'd think so maybe, but look again: on a sphere, pi changes in value as
>your circle gets bigger or smaller. The largest circle on a sphere has pi
>= 2, and the limit as they get infinitesimal is back up to our \pi again.

- reflect a hyperbola below the x-axis, and then rotate the
result about the y-axis to form a solid of a circular cross-
section when viewed along the y axis. employ francis sandow
to build a world of this form in orbit about a suitable star
of similar form. you have now achieved:

- a] _Inverted World_ (or a close facsimile thereof)

- b] a surface upon which the relationship between a circle
and its diameter is about as weird as i can currently
imagine - and highly unlikely to equal 3.1415...

- i don't know whether the value of pi would remain constant
upon such a surface, but i shouldn't be surprised if it did.

- and it does, bend space in that fashion [a], and guess the
name of at least one of your parents' male siblings (real,
virtual or imaginary).

- love, ppint.
[drop the "v", and change the "f" to a "g", to email or cc.]

[a] - minor practical detail left as an exercise for the reader
--
"One's mind, once stretched by a new idea,
never regains its original dimensions."
- Oliver Wendell Holmes

[Jack Tingle]

On 6/9/2012 4:12 AM, tphile2 wrote:

> I had the same problem watching Ridley Scotts new movie Prometheus.
> When you are astronauts making first contact on an alien planet and
> alien structure with everything alien and unknown, you DON'T take off
> your space helmet regardless if the air is breathable. You have no
> idea what you are getting exposed too. Regardless if your suit and
> defenses are ineffective.etc. Also something cute can be very
> deadly. Also the bridge and everything else should be manned and
> watched around the clock. and thats just for starters.

80% of all sci-fi stories collapse if someone actually reads and follows
the "Space Traveler Handy Survival Checklist" instead of winging it.

"...And then the funky egg opened and tried to insert itself into the
lungs of the robotic manipulator arm. Ripley triggered the incineration
function on the isolation chamber, and the weird bug-like egg-carrier
shriveled and died. "Well, that's an odd one," she said, and they broke
for lunch."

Lousy sci-fi story. And probably too short to make much money on.

Make that 95% of all "Star Trek: Enterprise" stories.

Regards,
Jack Tingle

[Scott Fluhrer]

"Robert Carnegie" <rja.ca...@excite.com> wrote in message
news:16442322-2b0b-448e...@googlegroups.com...
> The history revealed in Douglas Adams'
> _Life, the Universe, and Everything_
> is IIRC twenty billion years old,
> in a universe broadly similar to the
> present day. But the universe in fact
> is less than 15 billion years old.

That is, indeed, a disappointing error in a work that is otherwise known as
diamond-hard SF...

--
poncho

[David DeLaney]

ppint. at pplay <v$af$pp...@i-m-t.demon.co.uk> wrote:
> d...@gatekeeper.vic.com "David DeLaney" observed:

>>You'd think so maybe, but look again: on a sphere, pi changes in value as
>>your circle gets bigger or smaller. The largest circle on a sphere has pi
>>= 2, and the limit as they get infinitesimal is back up to our \pi again.
>
> - reflect a hyperbola below the x-axis, and then rotate the
> result about the y-axis to form a solid of a circular cross-
> section when viewed along the y axis. employ francis sandow
> to build a world of this form in orbit about a suitable star
> of similar form. you have now achieved:
>
> - a] _Inverted World_ (or a close facsimile thereof)
>
> - b] a surface upon which the relationship between a circle
> and its diameter is about as weird as i can currently
> imagine - and highly unlikely to equal 3.1415...
>
> - i don't know whether the value of pi would remain constant
> upon such a surface, but i shouldn't be surprised if it did.

Doesn't; you're attempting to build a solid of constant negative curvature,
and getting as close as one can get embedded in 3-d space. This _also_ has
the feature that very very small circles see the surface as Flat and have
pi about equal to \pi. Larger circles have pi > \pi because they've got more
circumference than they should for a given diameter; it never gets DOWN to
3 on this kind of thing.

Both this and the sphere suffer from _having_ a constant curvature, from which
you can extract a length (inverse curvature ["Four circles to the kissing come,
the smaller are the benter; the bend is just the inverse of the distance from
the center..."]). Features inscribed on the surface have different properties
at different sizes partly because there IS this length to compare things to.

[Walter Bushell]

In article <ylfkehpp...@dd-b.net>,

David Dyer-Bennet <dd...@dd-b.net> wrote:

> I don't believe being normal in one base implies being normal in all
> others; there's a term, "absolutely normal", for numbers that are normal
> in all bases. (This may, however, be one of those cases where we simply
> haven't been able to prove it yet.)

I would think normal in one base would imply normal in all bases on
intuitive grounds, but if not, I would fall back to normal in some
bases and not in others is a set of measure zero.

--
This space unintentionally left blank.

[tphile2]

Sure that is easy to say if WSoD is strict but some strikes can be
allowed. It's just that there is a limit when there are too many or
if they are too major. I had a lot more but did not want to say so
as to avoid spoilers. When you see the movie, you should see what I
mean.
However I think the production design of the Prometheus and some other
sets are awe inspiring and will get the blue ray when it comes out.
but its storytelling that counts most and where WSoD succeeds or fails

[Stephen Harker]

As long as it is not "in all cities all over the world" it can be
---
quite accurate. For some "in cities all over the world" merely
requires more than one city that are geographically separated. For
most people it would require considerably more than one, but how many?
Possibly 100 cities in the northern hemisphere would be adequate.

Beyond that, the southern hemisphere is not out of bounds. I recall
people telling me that it snowed at Christmas Eve one year in the
1970s in Queanbeyan (just outside Canberra). I would image that there
are cities in southern New Zealand or South America that would be
plausible candidates; reasonable altitude and unusual weather
conditions would be likely requisites.

--
Stephen Harker s.ha...@adfa.edu.au
PEMS http://sjharker.customer.netspace.net.au/
UNSW@ADFA

[Dan Goodman]

To repeat: It's a given of the story that, due to magic or an
equivalent, it is snowing in cities ALL OVER THE WORLD. Including
cities where snow wouldn't fall (without magic) unless there was the
sudden onset of another ice age; and ones where an ice age wouldn't be
enough.

The story is fantasy, so I gave that a pass.

--
Dan Goodman

[Brian M. Scott]

On Fri, 08 Jun 2012 22:26:37 -0400, David DeLaney
<d...@gatekeeper.vic.com> wrote in
<news:slrnjt5bq...@gatekeeper.vic.com> in
rec.arts.sf.written:

> Michael Stemper <mste...@walkabout.empros.com> wrote:

>>(I'm trying to figure out what the definition of "length of the
>>circumference in the taxicab metric would be, and failing.)

> That's easy, really - in taxicab pi equals 4, because
> circles are effectively square.

And in that metric pi *are* square.

Brian

[Brian M. Scott]

On Fri, 08 Jun 2012 16:30:09 -0500, David Dyer-Bennet
<dd...@dd-b.net> wrote in <news:ylfkehpp...@dd-b.net> in
rec.arts.sf.written:

[...]

> I don't believe being normal in one base implies being normal in all

> others; [...]

It doesn't. Let N(r) be the set of numbers normal in base
r. In 1960 Wolfgang Schmidt proved that N(r)=N(s) iff
ln(r)/ln(s) is rational, i.e., iff there are integers m and
n such that r^m =s^n. If r and s are distinct primes this
is clearly not the case.

He even showed that if ln(r)/ln(s) is irrational, there are
2^omega numbers normal in base r whose digits in base s
aren't even uniformly distributed.

Brian

[Robert Carnegie]

On Saturday, June 9, 2012 2:01:17 PM UTC+1, jack tingle wrote:
> On 6/9/2012 4:12 AM, tphile2 wrote:
>
> > I had the same problem watching Ridley Scotts new movie Prometheus.
> > When you are astronauts making first contact on an alien planet and
> > alien structure with everything alien and unknown, you DON'T take off
> > your space helmet regardless if the air is breathable. You have no
> > idea what you are getting exposed too. Regardless if your suit and
> > defenses are ineffective.etc. Also something cute can be very
> > deadly. Also the bridge and everything else should be manned and
> > watched around the clock. and thats just for starters.
>
> 80% of all sci-fi stories collapse if someone actually reads and follows
> the "Space Traveler Handy Survival Checklist" instead of winging it.
>
> "...And then the funky egg opened and tried to insert itself into the
> lungs of the robotic manipulator arm. Ripley triggered the incineration
> function on the isolation chamber, and the weird bug-like egg-carrier
> shriveled and died. "Well, that's an odd one," she said, and they broke
> for lunch."

It is a culture that doesn't like to risk
expensive robots on work that can be done
by replaceable humans, and actually wants
to collect live Aliens to put to use.
So, the crew are bait / grow-bags.
Except for you-know-who.

[Stephen Harker]

Quite possibly. But in the bit I saw quoted there is nothing to
require that interpretation. I admit I missed the original post which
may have given more information. But the words quoted don't require
such an interpretation.

[Robert Carnegie]

On Sunday, June 10, 2012 9:21:23 AM UTC+1, Stephen Harker wrote:

> Dan Goodman <dsg...@iphouse.com> writes:
>
> > To repeat: It's a given of the story that, due to magic or an
> > equivalent, it is snowing in cities ALL OVER THE WORLD. Including
> > cities where snow wouldn't fall (without magic) unless there was the
> > sudden onset of another ice age; and ones where an ice age wouldn't be
> > enough.
>
> Quite possibly. But in the bit I saw quoted there is nothing to
> require that interpretation. I admit I missed the original post which
> may have given more information. But the words quoted don't require
> such an interpretation.

But this /is/ newsgroup rec.arts.sf.written ...

If we discuss a story about, say, an astronaut,
it's unlikely to be factual.

It might be Astronaut Barbie in the case when
the doll comes with Glow-in-the-dark moon rocks.
I assume that moon rock doesn't usually glow in
the dark, or the moon wouldn't have phases...

[Gerry Quinn]

In article <slrnjt5bn...@gatekeeper.vic.com>,
d...@gatekeeper.vic.com says...

> Right. We don't know WHY mathematics fits the physical universe so closely
> (to such a degree that we keep finding instances in physics where purely
> theoretical pieces of math are suddenly useful and accurate).

We don't. We keep inventing *models* that use bits of math we didn't
use before. Our models are mathematical, so obviously mathematics fits
them - but the models are not the physical universe.

For example, Newtonian gravity and general relativity are models that
use quite different maths. Newton invented a new sort of maths for his
models, and later it was a surprise to many when the sort of maths used
for general relativity turned out useful. But both are only approximate
models for gravity, not gravity itself. Maths fits our models for
gravity - we've no reason to suppose that it fits gravity.

- Gerry Quinn

[Robert Carnegie]

Well, our models fit with observations, and
better than "approximately". Give-or-take
that pesky dark matter, dark energy, business.
And that relativity and quantum mechanics are
written in different languages.

Actually, I believe maths is only our model of
maths. Numbers, if they are real things, are
distinct from our ideas of numbers.

[Walter Bushell]

In article <1uwbkcc3klw8b$.j8hp1us...@40tude.net>,

Shows I haven't been reading the research.

[tphile2]

Astronaut Barbie? Now THAT is a WSoD Jolt.

What's next?
Pak Protector Barbie?
Barsoom Princess Barbie?
Jedi Master Barbie?
Barbie Heterodyne and her Jager Barbies?
Predator Barbie?
Space Jockey Barbie and Prometheus Ken?
Kzinti Barbie?
Admiral Barbie Harrington?
Barbie Vorkosigan?
My Big Fat Barbie Wedding?

[Brett Dunbar]

In message
<44b3d769-153c-45f1...@h10g2000yqn.googlegroups.com>,
tphile2 <tph...@cableone.net> writes

>On Jun 10, 6:15 am, Robert Carnegie <rja.carne...@excite.com> wrote:
>> It might be Astronaut Barbie in the case when
>> the doll comes with Glow-in-the-dark moon rocks.
>> I assume that moon rock doesn't usually glow in
>> the dark, or the moon wouldn't have phases...
>
>Astronaut Barbie? Now THAT is a WSoD Jolt.

The glow-in-the-dark moon rocks mean that would be the 1994 Astronaut,
Barbie, commemorating the 25th anniversary of Apollo 11, as opposed to
the 1965 or 1985 versions.
--
Great Internet Mersenne Prime Search http://www.mersenne.org/prime.htm
Livejournal http://brett-dunbar.livejournal.com/
Brett Dunbar

[Robert Carnegie]

On Sunday, June 10, 2012 10:26:22 PM UTC+1, Brett Dunbar wrote:
> In message
> <44b3d769-153c-45f1...@h10g2000yqn.googlegroups.com>,
> tphile2 <tph...@cableone.net> writes
> >On Jun 10, 6:15 am, Robert Carnegie <rja.carne...@excite.com> wrote:
> >> It might be Astronaut Barbie in the case when
> >> the doll comes with Glow-in-the-dark moon rocks.
> >> I assume that moon rock doesn't usually glow in
> >> the dark, or the moon wouldn't have phases...
> >
> >Astronaut Barbie? Now THAT is a WSoD Jolt.
>
> The glow-in-the-dark moon rocks mean that would be the 1994 Astronaut,
> Barbie, commemorating the 25th anniversary of Apollo 11, as opposed to
> the 1965 or 1985 versions.

I knew that! ...What?

[Robert Carnegie]

Is anyone else experiencing an almost entirely
new desire to be a collector... if not a
completist, no...

Redshirt Barbie, except that you'd need
to buy a new doll each week - you could
re-use the costume, though, usually.
(Bloodstains, plasma burns, Horta slime...)

I suppose that Barbierella was possibly part
inspired by Barbie in the first place?

(Wikipedia explains, "During a trip to Europe
in 1956 with her children Barbara and Kenneth,
Ruth Handler came across a German toy doll
called Bild Lilli", who was a comic-strip
character in Die Bild-Zeitung ["The Illustrated
News", approximately].)

The Talented Nostromo Warrant Officer Barbie
might sell... to one character from a
Terry Pratchett novel series, anyway. Big fan.

Which brings us to Nosbarbieratu, and
Metropobarbielis... hmm, is this still working?

But it's film-centric...

Foundation Barbie is to practise make-up on.

Slan Barbie has actual unrealistic hair!

The Dunwich Barbie... not many takers, I suspect.

[David DeLaney]

tphile2 <tph...@cableone.net> wrote:
>Astronaut Barbie? Now THAT is a WSoD Jolt.
>
>What's next?
>Pak Protector Barbie?

>Barbie Heterodyne and her Jager Barbies?

>Barbie Vorkosigan?

...ADD TO CART

Dave "and/or CWIDDER" DeLaney

[David DeLaney]

On Sun, 10 Jun 2012 15:44:50 +0100, Gerry Quinn <ger...@gmail.com> wrote:
>d...@gatekeeper.vic.com says...
>> Right. We don't know WHY mathematics fits the physical universe so closely
>> (to such a degree that we keep finding instances in physics where purely
>> theoretical pieces of math are suddenly useful and accurate).
>
>We don't. We keep inventing *models* that use bits of math we didn't
>use before. Our models are mathematical, so obviously mathematics fits
>them - but the models are not the physical universe.

Right - but the models that are being invented and used in physics are being
done so to BECAUSE they fit the physical universe in one way or another. So
let me expand the above to "we keep finding instances in the modelling of
the physical universe with mathematics where purely theoretical pieces of
math are suddenly useful and give accurate modelling".

>For example, Newtonian gravity and general relativity are models that
>use quite different maths. Newton invented a new sort of maths for his
>models, and later it was a surprise to many when the sort of maths used
>for general relativity turned out useful. But both are only approximate
>models for gravity, not gravity itself. Maths fits our models for
>gravity - we've no reason to suppose that it fits gravity.

No, but we've excellent reasons to suppose that the models are fitting the
physical observations of what we call 'gravity', in various ways. Of course
we don't know what the UrStuff of the Universe _is_, or why it works - we just
have these lying physical senses to work with, all going into a jellylump that
_interprets_ them as various things Out There. But we've got some mental
and mathematical models that give answers that are really really consistent
with what we sense the measurements we think we're making give.

Dave

[Greg Goss]

tphile2 <tph...@cableone.net> wrote:

>On Jun 10, 6:15�am, Robert Carnegie <rja.carne...@excite.com> wrote:

>> It might be Astronaut Barbie in the case when
>> the doll comes with Glow-in-the-dark moon rocks.
>> I assume that moon rock doesn't usually glow in
>> the dark, or the moon wouldn't have phases...
>
>Astronaut Barbie? Now THAT is a WSoD Jolt.

You must be a different generation than I was. I remember all sorts
of barbies in high-status career choices, including the astronaut.

Have they gone back to the basic photo-model-only career?
--
I used to own a mind like a steel trap.
Perhaps if I'd specified a brass one, it
wouldn't have rusted like this.

[tphile2]

On Jun 10, 7:35 pm, Greg Goss <go...@gossg.org> wrote:

I grew up with real astronauts like Major Matt Mason and his crew
along with NASA. NOT the fashionista wannabes like Barbie that says
the clothes make the person

[David Johnston]

On 6/10/2012 6:35 PM, Greg Goss wrote:
> tphile2<tph...@cableone.net> wrote:
>
>> On Jun 10, 6:15 am, Robert Carnegie<rja.carne...@excite.com> wrote:
>
>>> It might be Astronaut Barbie in the case when
>>> the doll comes with Glow-in-the-dark moon rocks.
>>> I assume that moon rock doesn't usually glow in
>>> the dark, or the moon wouldn't have phases...
>>
>> Astronaut Barbie? Now THAT is a WSoD Jolt.
>
> You must be a different generation than I was. I remember all sorts
> of barbies in high-status career choices, including the astronaut.
>
> Have they gone back to the basic photo-model-only career?

Based on the last advertisements I saw, Barbie has exciting careers as
kindergarten teacher and cook.

[Robert Carnegie]

According to Wikipedia, Barbie was in the
space programme before Matt Mason was.

Barbie evidently is a polymath.

<http://en.wikipedia.org/wiki/Christa_McAuliffe>
is a name that I'd forgotten, having somehow
mentally substituted
<http://en.wikipedia.org/wiki/Sally_Ride>
who has a resume of more scientific qualifications
and fewer terrible accidental deaths, but
who seems to have decided to quit flying on
Space Shuttles after they started blowing up,
and instead, to do something about that,
from the ground.

[Michael Stemper]

In article <ylfkipf1...@dd-b.net>, David Dyer-Bennet <dd...@dd-b.net> writes:
>mste...@walkabout.empros.com (Michael Stemper) writes:

>> If Pi is actually normal (base ten), wouldn't its decimal representation
>> have infinitely many pictures of circles? And trailers for the real Star
>> Wars prequel movies?
>
>Yes.
>
>But we don't know if it is.

Hence the wording, "if Pi is actually normal".

--
Michael F. Stemper
#include <Standard_Disclaimer>
Life's too important to take seriously.

[Robert Carnegie]

On Monday, June 11, 2012 1:43:17 PM UTC+1, Michael Stemper wrote:
> In article <ylfkipf1...@dd-b.net>, David Dyer-Bennet <dd...@dd-b.net> writes:
> >mste...@walkabout.empros.com (Michael Stemper) writes:
>
> >> If Pi is actually normal (base ten), wouldn't its decimal representation
> >> have infinitely many pictures of circles? And trailers for the real Star
> >> Wars prequel movies?
> >
> >Yes.
> >
> >But we don't know if it is.
>
> Hence the wording, "if Pi is actually normal".

Yes. Note the reply to Philip II of Macedon:
<http://en.wikipedia.org/wiki/Laconic_phrase>
aka _The Spartans' Joke Book In Its Entirety_.

[Michael Stemper]

In article <acaf297c-362a-4ec9...@v9g2000vbc.googlegroups.com>, david.sh...@ymail.com writes:
>On Jun 8, 1:15=A0pm, mstem...@walkabout.empros.com (Michael Stemper) wrote:

>> Is it possible to have a space in which C/d is uniformly 3? Would you
>> need a different metric function, or could a space be shaped this way?

>>
>> (I'm trying to figure out what the definition of "length of the
>> circumference in the taxicab metric would be, and failing.)
>

>Not exactly a mathematician here, but ...
>
>A metric function should be able to be characterized by
>its unit ball, B, the set of points at distance 1 from a center.

So far, so good.

>I think this needs to be centrally symmetric and convex.

For all metric functions? I think not:
<http://mathworld.wolfram.com/FrenchMetroMetric.html>
<http://mathworld.wolfram.com/DiscreteMetric.html>

>A curve has length, according to this metric, equal to
>the limit as r goes to 0 of r times the number of balls of radius
>r/2 required to cover the curve.

I'll have to mull this over.

>If I understand correctly, the taxicab metric between points (a,b) and
>(c,d) is |a-c| + |b-d|.

Yes.

> The corresponding unit ball is a square with sides
>of Euclidean length square_root(2), rotated by 45 degrees. That is,
>the set of points (x,y) so that |x|+|y| <=3D 1.

Yup.

>If we choose the metric whose unit ball is a regular hexagon,
>each of the six sides has length 1, so C=3D6, d =3D 2, and C/d=3D3.

I haven't heard of this one. Does it have a name? Are there metric
functions corresponding to all regular n-gons? The following part
implies it.

>Based on this tiny sample, I would conjecture that, for unit balls
>which are regular n-gons, C/d is greater than pi if n =3D 0 modulo 4,
>and C/d is less than pi if n =3D 2 modulo 4.
>
>(n odd gives non-centrally symmetric polygons, which are not allowed.)

[Michael Stemper]

ObSFW: "The Feeling of Power", in which a new discovery allows humans
to replace expensive computers in guided missles.

[Michael Stemper]

In article <44b3d769-153c-45f1...@h10g2000yqn.googlegroups.com>, tphile2 <tph...@cableone.net> writes:

>On Jun 10, 6:15=A0am, Robert Carnegie <rja.carne...@excite.com> wrote:
>> On Sunday, June 10, 2012 9:21:23 AM UTC+1, Stephen Harker wrote:

>> > may have given more information. =A0But the words quoted don't require

>> > such an interpretation.
>>
>> But this /is/ newsgroup rec.arts.sf.written ...
>>
>> If we discuss a story about, say, an astronaut,
>> it's unlikely to be factual.
>>
>> It might be Astronaut Barbie in the case when
>> the doll comes with Glow-in-the-dark moon rocks.
>> I assume that moon rock doesn't usually glow in
>> the dark, or the moon wouldn't have phases...
>
>Astronaut Barbie? Now THAT is a WSoD Jolt.
>
>What's next?

"The Barbie Murders", I believe.

>Pak Protector Barbie?
[snip]
>Barbie Vorkosigan?

Reaching cross-thread, how about _Barbie Zombies_?

[Ernest Dotson]

On Jun 10, 7:35 pm, Greg Goss <go...@gossg.org> wrote:

> tphile2 <tphi...@cableone.net> wrote:
> >On Jun 10, 6:15 am, Robert Carnegie <rja.carne...@excite.com> wrote:
> >> It might be Astronaut Barbie in the case when
> >> the doll comes with Glow-in-the-dark moon rocks.
> >> I assume that moon rock doesn't usually glow in
> >> the dark, or the moon wouldn't have phases...
>
> >Astronaut Barbie?  Now THAT is a WSoD Jolt.
>
> You must be a different generation than I was.  I remember all sorts
> of barbies in high-status career choices, including the astronaut.
>
> Have they gone back to the basic photo-model-only career?

I got my niece a Computer Engineer Barbie for Christmas just this last
year.

[Bill Snyder]

How do you tell? Does she have a pocket protector?

--
Bill Snyder [This space unintentionally left blank]

[Ernest Dotson]

Here:

http://www.amazon.com/Barbie-Can-Computer-Engineer-Doll/dp/B0042ESG9W

[Greg Goss]

From the comments:

>"BARBIE USES LINUX!! There's a freaking Tux Penguin on her shelf!"

I'm not sure if Momma knows who Tux is, but it sounds like the kid
does.

[david.sh...@ymail.com]

On Jun 11, 12:43 pm, mstem...@walkabout.empros.com (Michael Stemper)
wrote:

> In article <acaf297c-362a-4ec9-8b89-d23a86ebd...@v9g2000vbc.googlegroups.com>, david.shallcr...@ymail.com writes:
> >A metric function should be able to be characterized by
> >its unit ball, B, the set of points at distance 1 from a center.
>
> So far, so good.
>
> >I think this needs to be centrally symmetric and convex.
>
> For all metric functions? I think not:
> <http://mathworld.wolfram.com/FrenchMetroMetric.html>
> <http://mathworld.wolfram.com/DiscreteMetric.html>

I was thinking about vector norms, which can
be characterized by their unit balls, which
are centrally symmetric and convex.
I think they also have to be closed, bounded,
and with a non-empty interior, in the finite-dimensional
case.

For bystanders, a vector norm is a real-valued function ||.||
such that
0) 0 <= ||x||
1) ||ax|| = |a| ||x|| for scalar a and vector x;
2) ||x + y|| <= ||x|| + ||y||; and
3) ||x|| = 0 implies x = 0
Its unit ball B is the set { x: ||x|| <= 1 }

For any x in B, we know ||-x|| = |-1| ||x|| = ||x|| <= 1,
so -x is also in B. (central symmetry)
For x, y in B, and 0 <= a <= 1, we know
|| ax + (1-a)y || <= |a| ||x|| + |1-a| || y|| <= a + (1-a) = 1,
so ax + (1-a) x in B. (convexity)

For such a B, we can define ||x|| = inf { a: (1/a)x in B, a >0 },
and we could derive (0), (1) and (2).
I needed B to have a non-empty interior to be sure this function
is finite, that is, that the infimum is over a non-empty set.
I needed B to be bounded to be sure (3) holds.

> >If we choose the metric whose unit ball is a regular hexagon,

> >each of the six sides has length 1, so C= 6, d = 2, and C/d= 3.

>
> I haven't heard of this one. Does it have a name? Are there metric
> functions corresponding to all regular n-gons?

I don't know of a standard name. It's the gamer's hex-grid metric.
(Does anyone still play tabletop games on a hex grid?}
There are vector norms, and therefore metric functions, corresponding
to all centrally symmetric polygons, but I haven't heard of any
names other than for 4-gons. The vector norm construction doesn't
work for n-gons for odd n.

- David

[david.sh...@ymail.com]

On Jun 10, 3:30 pm, tphile2 <tphi...@cableone.net> wrote:
> What's next?
...

> Barbie Heterodyne and her Jager Barbies?

Klaus Barbie?

[Tim McDaniel]

In article <jr58j2$m0i$3...@dont-email.me>,

Michael Stemper <michael...@gmail.com> wrote:
>In article <44b3d769-153c-45f1...@h10g2000yqn.googlegroups.com>, tphile2
><tph...@cableone.net> writes:

>>Pak Protector Barbie?

I went "HA!" out loud at that. I really shouldn't read Usenet at an
open-plan office.

>Reaching cross-thread, how about _Barbie Zombies_?

They *haven't* done Vampire Barbie yet, covered in glitter or no?

--
Tim McDaniel, tm...@panix.com

[Moriarty]

On Jun 8, 8:38 pm, Robert Carnegie <rja.carne...@excite.com> wrote:
> Bob Shaw's _The Ragged Astronauts_ has some
> nice bits about the culture in the story
> inventing, I think, algebra, but then
> totally annoys me by having someone explain
> that in that universe, pi equals three.
>
> Pi is fundamental in mathematics, and it
> can't have another value.
>
> Pi/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - ...
> or something like that.
> You can't change /that!/
>
> In other pi news, Star Trek book _Memory Prime_
> has a compter that worked out pi as a repeating
> decimal (in which case it would be just an
> improper fraction, which it isn't), and at
> the end of Carl Sagan's _Contact_, the reader
> (but not yet the characters) is informed of
> the discovery in pi of a message from God.
>
> Well, God isn't allowed to change pi, either.
> (Even though the bible also incorporates an
> apparent belief at the time that pi is 3 -
> at least for government work...)

Pi changed values in Greg Bear's _Eon_ too. Early in Eon, one of the
characters has a pi-meter and tells a companion that pi is a little
low. I just shrugged it off as "it's SF involving weird geometry".

-Moriarty

[Moriarty]

On Jun 11, 8:37 am, Robert Carnegie <rja.carne...@excite.com> wrote:

<snip>

> The Dunwich Barbie... not many takers, I suspect.

http://www.thelovecraftsman.com/2012/05/behold-cthulhu-barbie.html

-Moriarty

[Mad Hamish]

On Fri, 08 Jun 2012 13:16:34 +0100, Jaimie Vandenbergh
<jai...@sometimes.sessile.org> wrote:

>On Thu, 07 Jun 2012 22:11:11 -0500, Dan Goodman <dsg...@iphouse.com>
>wrote:
>
>>In Connie Willis's short story "Just Like the Ones We Used to Know,"
>>it's snowing around Christmas in cities all over the world -- including
>>Honolulu. At a conference of experts, character says -"It never snows
>>in Hawaii."
>>
>>It does snow in Hawaii; though only at very high altitudes. An expert
>>would not say that.
>
>I'd be more worried about "all over the world" - including Melbourne
>and Auckland?
>
I've seen snow fall in Hobart, tasmania on Christmas day (it didn't
settle but it did fall)
--
"Hope is replaced by fear and dreams by survival, most of us get by."
Stuart Adamson 1958-2001

Mad Hamish
Hamish Laws
newsunsp...@iinet.unspamme.net.au

[David DeLaney]

Tim McDaniel <tm...@panix.com> wrote:
>>tphile2 <tph...@cableone.net> writes:
>>>Pak Protector Barbie?
>
>I went "HA!" out loud at that. I really shouldn't read Usenet at an
>open-plan office.

Note that here she'd have a REASON to have nonrepresentational genitalia...