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the antikythera device

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ppint. at pplay

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May 14, 2013, 4:27:03 AM5/14/13
to
- hi; in article,
<qPqdnQ4FgM62VgzM...@posted.internetamerica>,
"in another place"
gordon...@burditt.org "Gordon Burditt" enquired:

>> The other day I was reading a review of "Beyond the Sea Gate of the
>> Scholar Pirates of Sarskoe", an excellent short story by Garth
>> Williams. It's a nautical tale, but the reviewer pointed out,
>> correctly I think, that predicting tides would be impossible in
>> a world with three moons. Apparently this bothered the reviewer.
>> http://en.wikipedia.org/wiki/N-body_problem
>
>How would you feel about the possibility (in the real world) of a
>mechanical computer from about 2,000 years ago used to predict
>eclipses and various astronomical events? Granted, the Earth, Sun,
>Moon and various planets don't interact as strongly as three moons
>would, but predicting eclipses takes a lot more accuracy than
>predicting tides.
>
>It's well before Newton. There are questions about how they could
>fashion gears accurately enough. It also seems to require a lot
>more astronomical knowledge than people of that time are given
>credit for by modern historians.
>
>PBS NOVA describes such a device found on a Greek ship in an episode
>called "Ancient Computer". It wasn't recovered intact so there may
>be a lot more that it could do, or functions we haven't figured out yet.

- the innards of the antikythera device have been investi-
gated and a working copy made: iiuc it worked better, once
what had at first been presumed inaccurately made (or worn
down) parts in the original, and modelled more precisely,
were modified to more accurately reproduce the degrees of
freedom possessed by the original parts. and a method of
cutting and shaping gear wheels and their teeth to the re-
quired accuracy that was within the technical and technol-
ogical abilities of late classical greek metal-working has
also been demonstrated. observations by the naked eye of
the planets out to saturn had been made with sufficient acc-
uracy and over sufficient length of time for their, the sun
and the moon's motion to've been predictable also: i believe
a plausible explanation of how the device came to have ended
up in the shipwreck with which it is associated has also
been made, and a stab at identifying who may have designed it.

- and all without the invocation of ancient spacemen or gods!

- love, a ppint. as suspects only the absence of glass [a]
prevented the inclusion of the galilean satellites & uranus

[a] - and possibly of earwigs, or a particular hero earwig - ?

n.b. cross-posted, with follow-up currently set to a.b.t-h

[drop the "v", and change the "f" to a "g", to email or cc.]
--
"sunspots are important because scientists now know
they can affect the british climate."
- horizon: global weirding, bbc4, 20:35 bst (19:35 gmt) 2/4/13









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ppint. at pplay

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May 18, 2013, 1:31:01 PM5/18/13
to
- hi; in article, <20130514205709....@firedrake.org>,
firedrake r. <roger+ab...@nospam.firedrake.org> observed:
> "ppint. at pplay" wrote:
>> - love, a ppint. as suspects only the absence of glass [a]
>> prevented the inclusion of the galilean satellites & uranus
>
>No point in trying to predict the motion of moons if they're going to
>get batted around by dragons every few months.

- i've come across dragon dice, of course: does this mean
dragons're also adept at 3-4D pool, billiards and snooker?
>
>(Ancient dragons being of course much more plausible than ancient
>astronauts.)

- ancient dragons are indeed very plausible - according to
some stories, dragons were the first creatures to learn how
to use language to confuse and deliberately deceive...

- love, a ppint. uncertain as to the wisdom contained herein
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j...@cix.compulink.co.uk

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May 19, 2013, 1:39:47 PM5/19/13
to
In article <20130519111555....@firedrake.org>,
roger+ab...@nospam.firedrake.org (Roger Bell_West) wrote:

> I'm afraid it's simpler than that: I make things up. It is very
> difficult for a dragon to tell a lie, because the universe shifts
> around to make it truth.

Presumably if two dragons have incompatible ideas, they realise when the
changes start to conflict, and they'll decide on a solution? Otherwise
one fears it would get somewhat tiring for them to keep changing things
back-and-forth.

--
John Dallman, village zombie and fish-and-chip-cart operator.
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ppint. at pplay

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May 19, 2013, 4:32:27 PM5/19/13
to
- hi; in article, <20130519185331....@firedrake.org>,
firefrake r <roger+ab...@nospam.firedrake.org> expanded:
> j...@cix.compulink.co.uk wrote:
>>Presumably if two dragons have incompatible ideas, they realise when the
>>changes start to conflict, and they'll decide on a solution? Otherwise
>>one fears it would get somewhat tiring for them to keep changing things
>>back-and-forth.
>
>Either that or one of them explains to the other that it

- the other ?

> doesn't hold that idea any more.
>
>(See also Niven's solution to the problem of time travel.)

- the solution with, or without, chocolate ?

- (emwltk & all that)

- love, ppint.
[drop the "v", and change the "f" to a "g", to email or cc.]
--
"in a well-governed country, poverty is something to be ashamed of;
in a poorly-governed country, wealth is something to be ashamed of."
- attrib. confucius [ref. needed for quote]
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ppint. at pplay

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May 20, 2013, 1:06:29 AM5/20/13
to
- hi; in article, <20130519223340....@firedrake.org>,
firedrake r <roger+ab...@nospam.firedrake.org> explained:
> "ppint. at pplay" wrote:
>> firefrake r <roger+ab...@nospam.firedrake.org> expanded:
> ^
>I have been a friedrake before now...

- woops! apologies; at least i didn't also omit the second "r"...
>
>>>Either that or one of them explains to the other that it
>> - the other ?
>
>The others, if you prefer.

- took me quite a while to construe this response: i
hadn't realised that my question was ambiguous...

>(I am mildly distracted by a Visiting Hound.)

- *g* - my only visitor in _years_ has been one of
next-doors' cats, who occasionally checks on how this
particular corner of his territory is getting on...

(before they put a cat-flap into their back door, he
also used sometimes to beg shelter of an extra-cold
night; but not, for mere rain - even if torrential.)

>>>(See also Niven's solution to the problem of time travel.)
>> - the solution with, or without, chocolate ?
>
>That was more a problem of space travel, really. I was thinking of
>http://www.isfdb.org/cgi-bin/title.cgi?115991 .

- i'll look up which story that is later today, once
the library^W "local links" opens (arachne's stopped
working on i-m-t, since ramboost.exe suddenly found
it impossible to configure itself, so i can't web-
wander from home).

- love, a ppint. as isn't greatly reassured by any
purported solution that excludes chocolate...
[drop the "v", and change the "f" to a "g", to email or cc.]
--
Vat girls - the missing piece to the puzzle of Utopia.
- "quadibloc" (j savard @ecn.dot.ab.dot.ca) on rasfwr
(09:08:03 -0700) 16:08:03 gmt 14/8/10 (8/14/10 for merkins)
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ppint. at pplay

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May 21, 2013, 11:40:27 AM5/21/13
to
- hi; in article, <20130520165139....@firedrake.org>,
firedrake r <roger+ab...@nospam.firedrake.org> elaborated:
> "ppint. at pplay" wrote:
>> - i'll look up which story that is later today, once
>> the library^W "local links" opens (arachne's stopped
>> working on i-m-t, since ramboost.exe suddenly found
>> it impossible to configure itself, so i can't web-
>> wander from home).
>
>Sorry.

- 's ok: you'd no way of knowing (and i can grab web files
with this gremnos/ka9q; it's just that people've developed
a habit of incorporating eleventy-seven ginormous gifs and
suchlike on every web page which, whilst it may be pretty
in 14,401,028 colours on 75" monitors, take entire oodles
of time to download on dial-up via wet - or dry - string.)

>"Exercise in Speculation: The Theory and Practice of Time Travel",
>as collected in "All the Myriad Ways".

- ah, yes. _that_ one. i thought an august firedrake (r.)
might've been more likely to relate to one (or more) of the
svetz stories - "there's a werewolf in my time-machine",
perhaps - or the ostrich story...

>Specifically the theory that if time travel is possible and permits
>of changing the past, it will never be invented. Logic, summarised:
>If it's possible, somebody will do it.

- ", sooner or later..." - but there is only a probability,
higher or lower, of this occurring: if, in an infinite uni-
verse, all variations _necessarily_ occur, then eventually
that of the infinite universe never having occurred must
arise...
<snip>
>If there _is_ historical inertia, the simplest way for the past to be
>protected from interference is for time machines to stop working permanently.

- would this be tantamount to declaring ftl communication
forever impossible?

- love, a ppint. as can't help but wonder
[drop the "v", and change the "f" to a "g", to email or cc.]
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ppint. at pplay

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May 22, 2013, 11:52:58 AM5/22/13
to
- hi; in article, <20130522120143....@firedrake.org>,
<roger+abth201305@.firedrake.org> "firedrake r" feelingcitated:
> "ppint. at pplay" wrote:
>> - 's ok: you'd no way of knowing (and i can grab web files
>> with this gremnos/ka9q; it's just that people've developed
>> a habit of incorporating eleventy-seven ginormous gifs and
>> suchlike on every web page which, whilst it may be pretty
>> in 14,401,028 colours on 75" monitors, take entire oodles
>> of time to download on dial-up via wet - or dry - string.)
>
>You no longer have a text-based browser available? Shame. I like
>elinks.

- i've never met; i _may_ still have a text-based
browser one of the hard drives, somewhere downstairs -
but i've no idea which. (i may still have snewstune,
too, whose absence i've mostly worked around, for one
useful function, but do still miss, for another.)

>As it happens isfdb.org was having a bad day anyway.

- yes. the llinks broadbanded boxes couldn't get
through in an hour. well, in fifty-eight minutes.

>> - ah, yes. _that_ one. i thought an august firedrake (r.)
>> might've been more likely to relate to one (or more) of the
>> svetz stories - "there's a werewolf in my time-machine",
>> perhaps - or the ostrich story...
>
>Poor thing. It just didn't fly high enough.

- and i don't think it realised that it _couldn't_.
>
>>>Specifically the theory that if time travel is possible and permits
>>>of changing the past, it will never be invented. Logic, summarised:
>>>If it's possible, somebody will do it.
>> - ", sooner or later..." - but there is only a probability,
>> higher or lower, of this occurring: if, in an infinite uni-
>> verse, all variations _necessarily_ occur, then eventually
>> that of the infinite universe never having occurred must
>> arise...
>
>If nobody ever does it, it's functionally equivalent to a universe in
>which it can't be done.

- not necessarily; it may merely be one of the infinite
number of real universes, in which everything possible
does/has/will occur[ed]. (um, brion bayard & timelines?)

>><snip>
>>>If there _is_ historical inertia, the simplest way for the past to be
>>>protected from interference is for time machines to stop working permanently.
>> - would this be tantamount to declaring ftl communication
> forever impossible?
>
>"We _like_ causality. We've got _used_ to it."

- i'm certainly _happier_ with it - but i'm in no position
to insist upon it, if the universe i'm in chooses otherwise...

>Probably. I tend to say "Novikov" and run away.

- spin-paired electrons, can be _how_ far apart? - ?

- emwltk & all that - _many_ em...

- love, ppint.
[drop the "v", and change the "f" to a "g", to email or cc.]
--
"Earth occupies about one-half a degree in two dimensions."
- the real dick eney on rec.arts.sf.fandom, 10/5/2005 (5/10/2005 for merkins)
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