Thanks for posting this para - that is fascinating!
quote:
Originally posted by wrightd: I know that. What this person was saying was the possiblity of civilizations before all that, before land creatures, before the cephalapods and earlier life. Civilization so old it predates the fossils known as the beginning of multi-cell life on earth.
You'd have to dismiss almost all of the generally agreed upon geologic history of the Earth to be able to make this possible.
You only have integrity once. - imprezaguy02
June 01, 2023, 08:56 AM
parabellum
A 2011 presentation at Gresham College in London.
Of particular significance in this presentation is the 23:10 mark of the video, where the presenter points out a contemporary historical reference to Archimedes and the device.
From Cicero, 1st Century BC:
quote:
"The invention of Archimedes deserved special admiration because he had thought out a way to represent accurately by a single device for turning the globe those various and divergent movements with their different rates of speed."
June 01, 2023, 11:06 AM
flashguy
Around 11 minutes in she has a display in which it says 48 / 16 = 4, and this "fact" is repeated in several other formulae. Excuse me, but isn't 48 / 16 = 3? And no one in the hall mentioned it?
flashguy
Texan by choice, not accident of birth
June 01, 2023, 11:48 AM
kkina
quote:
Originally posted by flashguy: Around 11 minutes in she has a display in which it says 48 / 16 = 4, and this "fact" is repeated in several other formulae. Excuse me, but isn't 48 / 16 = 3? And no one in the hall mentioned it?
flashguy
@10:37 someone calls her on it, which she acknowledges. It actually doesn't affect the main points of the presentation.
Originally posted by flashguy: Around 11 minutes in she has a display in which it says 48 / 16 = 4, and this "fact" is repeated in several other formulae. Excuse me, but isn't 48 / 16 = 3? And no one in the hall mentioned it?
flashguy
@10:37 someone calls her on it, which she acknowledges. It actually doesn't affect the main points of the presentation.
I couldn't hear that person well. I agree that it isn't a negation of the process, but it is a distraction.
flashguy
Texan by choice, not accident of birth
June 01, 2023, 08:09 PM
StorminNormin
Para, thanks for posting this! I am watching it now and this is amazing. Also awesome that the website has 120 other PBS Nova episodes I want to watch!
NRA Benefactor Life Member
June 01, 2023, 08:36 PM
parabellum
Well, serendipity. This was posted just this evening on youtube. So far, I've scanned through it and watched portions of it totalling about 10 minutes. Looks to be well worth the time investment.
"Dr. Tony Freeth is a founding member of the Antikythera Mechanism Research Project and an Honorary Senior Research Associate at University College, London. He holds degrees in Mathematics from Cambridge University (UK) and Bristol University (UK). His work on the Antikythera Mechanism has been published in Nature (Freeth et al, Nature 2006 and Freeth et al, Nature 2008) as well as other prominent journals."
Towards the end of the video, he talks about how the calculations output by this computer were possible to perform manually by its ancient users, using trigonometry, but the calculations for determining, say, the exact position of the planet Mars on a certain date six months on, were quite time consuming, whereas the Antikythera Mechanism would provide an answer in one minute.
June 02, 2023, 08:23 AM
trapper189
It's a fascinating piece of machinery, but is it really a computer?
Other than complication, it's no different than a mechanical clock. It's essentially a collection of clocks attached to one crank. Each clock has a fixed function. Nobody would say f(x)=2x is a computer.
June 02, 2023, 08:31 AM
parabellum
Think of it however you want.
June 02, 2023, 08:18 PM
parabellum
Doing a bit of research on the Cicero quote, I found it in his De Re Publica (On the Republic) which was written by Cicero between 54 and 51 BC.
Keeping in mind this is a translation which differs from the one cited in the Jo Marchant/Gresham College lecture above, and that Cicero likely had never seen the device, Cicero refers to it as a globe. He also indicates similar but less complex devices had been built by others before Archimedes' model, and the suggestion is that the concept and the technology used by Archimedes was built upon this foundation.
"Then Philus said: I am not about to bring you anything new, or anything which has been thought over or discovered by me myself. But I recollect that Caius Sulpicius Gallus, who was a man of profound learning, as you are aware, when this same thing was reported to have taken place in his time, while he was staying in the house of Marcus Marcellus, who had been his colleague in the consulship, asked to see a celestial globe which Marcellus’s grandfather had saved after the capture of Syracuse from that magnificent and opulent city, without bringing to his own home any other memorial out of so great a booty; which I had often heard mentioned on account of the great fame of Archimedes; but its appearance, however, did not seem to me particularly striking. For that other is more elegant in form, and more generally known, which was made by the same Archimedes, and deposited by the same Marcellus in the Temple of Virtue at Rome. But as soon as Gallus had begun to explain, in a most scientific manner, the principle of this machine, I felt that the Sicilian geometrician must have possessed a genius superior to anything we usually conceive to belong to our nature. For Gallus assured us that that other solid and compact globe was a very ancient invention, and that the first model had been originally made by Thales of Miletus. That afterward Eudoxus of Cnidus, a disciple of Plato, had traced on its surface the stars that appear in the sky, and that many years subsequently, borrowing from Eudoxus this beautiful design and representation, Aratus had illustrated it in his verses, not by any science of astronomy, but by the ornament of poetic description. He added that the figure of the globe, which displayed the motions of the sun and moon, and the five planets, or wandering stars, could not be represented by the primitive solid globe; and that in this the invention of Archimedes was admirable, because he had calculated how a single revolution should maintain unequal and diversified progressions in dissimilar motions. In fact, when Gallus moved this globe, we observed that the moon succeeded the sun by as many turns of the wheel in the machine as days in the heavens. From whence it resulted that the progress of the sun was marked as in the heavens, and that the moon touched the point where she is obscured by the earth’s shadow at the instant the sun appears opposite." - Marcus Tullius Cicero, De Re Publica, Book I, XIV
So, tracing this device back to its first execution- if Cicero is to be believed- "For Gallus assured us that that other solid and compact globe was a very ancient invention, and that the first model had been originally made by Thales of Miletus."
It reminds me of a device I saw in the Frederiksborg Castle near Copenhagen, Denmark. It's called the Gottorp Celestial Globe with Internal Orrery or "Sphaera Copernicana". Here are a few photos of it:
The Sphaera Copernicana had a diameter of 1.34 m and an overall height of 2.40 m. It rested on a wooden base case that concealed a powerful spring-driven clockwork, which could run for eight days. Chimes occurred at hourly and quarter-hourly intervals, 24 motions in the armillary sphere were also driven by this device. The main drive shaft ran vertically from the centre of the clockwork through the whole armillary sphere. The shaft could be disengaged to drive the armillary sphere manually for demonstration purposes.
At the centre of the armillary sphere a brass sphere represented the Sun. Surrounding it were brass rings supported on rollers, which represented the orbits of the then known planets (Mercury, Venus, Earth, Mars, Jupiter and Saturn). The planets were represented by small silver figures that held their respective planet symbols in their hands. They revolved around the brass sphere at the same intervals as the real planets orbited the Sun. Sophisticated gearing ensured the correct transmission from the vertical drive shaft to the orbit ring. The position of each planet could be adjusted manually.
Exceptionally, the Earth orbit carried not a silver figure, but a miniature armillary sphere with spheres for Earth and Moon. The Earth rotates daily around an axis inclined to point to the celestial pole. The Moon orbits Earth in 27.3 days and displays its phases. A small dial on the miniature armillary sphere displays the time of day.
It was created in the early 1700s and was moved to the Frderiksborg Castle in 1872. It has been repaired several times and is functional.
This is a 1974 paper from the American Philosophical Society, downloadable.
June 04, 2023, 11:01 AM
ScreamingCockatoo
quote:
Originally posted by trapper189: It's a fascinating piece of machinery, but is it really a computer?
Other than complication, it's no different than a mechanical clock. It's essentially a collection of clocks attached to one crank. Each clock has a fixed function. Nobody would say f(x)=2x is a computer.
It is a computer. It can be programmed to give the results of the instruction set entered.
It's pre programmed albeit mechanically, to show the position of celestrial bodies at any given date.
The guidance computers on the Apollo were hardwired(woven) with instructions, yet it's still a computer. Using electrical impulses instead of gears. All with preset commands.
Anyone who thinks the Greeks were primitive in their use of mathematics and engineering is way off the mark. They just hadn't developed high precision tools yet.
He who fights with monsters might take care lest he thereby become a monster.
June 04, 2023, 10:34 PM
JohnO
Really great and enjoyable Nova episode.
In 1920 the "Clark Models" were shown at the world's fair. They purported to demonstrate the state of the art in mechanical apparatus.
Pretty humorous to see that 2100 years earlier much of this was old hat, plus some pretty cool math and astronomy.
Para thanks for sharing.
John
June 11, 2023, 12:34 PM
parabellum
Here are a couple of real goodies. First is a link to a downloadable book by Alexander Jones: A Portable Cosmos
I'm really surprised to find this available for free.
Secondly is a lecture at Stamford by Dr Tony Freeth, the gent we see and hear at the beginning of the Nova documentary in the first post in this thread and this is a quite remarkable lecture which illustrates the sheer genius of this device. Go to the 58 minute mark and you will see that the Antikythera Mechanism has a differential gearing system designed to compensate for the apparent variance in the speed of the Moon's orbit, which is due to its elliptical shape. As Dr. Freeth points out, the Greeks didn't understand elliptical orbits, but the shape of the Moon's orbit made the Moon appear to go faster or slower at times and is all-encompassed in a 9 year cycle. The creator of the device incorporated a gearing system to allow for calculation of all this and as Freeth, says, it's truly astonishing- shocking, even.
Freeth also speculates in great detail on the creator of the device and when it was created. Really great stuff.
Baltic2008_343 by David Casteel, on Flickr (overall view)
Baltic2008_347 by David Casteel, on Flickr (some of the gears) 
Baltic2008_346 by David Casteel, on Flickr (some of the gears) 
Baltic2008_348 by David Casteel, on Flickr (some of the gears) 