Antikythera-mekanismen

Antikythera-mekanismen.

Antikythera-mekanismen er en analog computer fra Oldtidens Grækenland, der er blevet beskrevet som det første eksempel på en sådan anordning,[1][2][3][4][5][6][7][8][9][4][10] som er blevet brugt til at forudse astronomiske positioner, formørkelser til brug i kalender og astrologiske formål flere årtier ud i fremtiden.[11][12][13] Den kunne også bruges til at følge den fire-årige cyklus for atletiske sportsgrene meget lig en olympiade, cyklussen for Antikkens olympiske lege.[14][15][16]

Artefaktets mekaniske diagram.

Artefaktet blev hentet op fra havet i 1901 og arkæologen Valerios Stais identificerede at den indeholdt tandhjul den 17. maj 1902,[17] blandt de vraggenstande, som blev hentet fra Antikythera-vraget ud for kysten ved den græske ø Antikythera.[18][19] Man antager at instrumentet er blevet designet og fremstillet af græske videnskabsfolk, og det er blevet dateret til enten 87 f.v.t.[20] eller mellem 150 og 100 f.v.t.[11] eller til 250 f.v.t.[21][22] eller inden for en generation før skibsvraget, som er blevet dateret til omkring 50-60 f.v.t.[23][24]

Anordningen, der sad i en trækasse på 34 cm × 18 cm × 9 cm, blev fundet i ét stykke og senere separeret i tre større fragmenter, der nu er opdelt i 82 separate fragmenter efter de er blevet konserveret. Fire af disse fragtmenter indeholdt tandhjul, mens der er fundet inskriptioner på mange andre.[25][26] Det største gear er omkring 14 cm i diameter og havde oprindeligt 223 tænder.[27]

Det er en kompleks urværk-mekanisme, som består af mindste 30 bronzetandhjul. Et hold forskere ledet af Mike Edmunds og Tony Freeth fra Cardiff University brugte moderne computerrøntgen-tomografi og overfladescanning i høj opløsning for at få billeder af fragmenterne inde i den knuste mekanisme, og for at kunne læse de udviskede inskriptioner, der oprindeligt har dækket kassen, som mekanismen har været monteret i.

Kortlægning af mekanismen indikerer, at den har haft 37 tandhjul, hvilket har gjort det muligt at følge Solen og Månens bevægelse igennem dyrekredsen, og at man har kunne forudse både sol- og måneformørkelser, og sågar har kunne modellere Månens irregulære bane, hvor månens hastighed er højere i dens apsis. Disse bevægelser blev studeret i det andet århundrede f.v.t. af astronomen Hipparchus fra Rhodos, og det er blevet foreslået, at han er blevet konsulteret under konstruktionen af maskinen.[28]

Viden om denne teknologi blev tabt på et tidspunkt i senantikken. Lignende teknologiske værker optræder i middelalderen i Det Byzantinske Rige og den Muslimske verden, men værker af samme kompleksitet optræder ikke før udviklingen af mekaniske astronomiske ure i Europa i 1300-tallet.[29] Alle de kendte fragmenter fra Antikythera-mekanismen bliver i dag opbevaret på det arkæologiske museum i Athen sammen med flere rekonstruktioner af mekanismen, der demonstrerer hvordan den kan have fungeret.[30]

Rekonstruktioner

Moderne rekonstruktion.

Mekanismen er rekonstrueret talrige gange og viser, at den virkede. I 2010 i lego.[31]

Rekonstruktionerne underbygger antikkens tekster. Cicero skrev i det 1. århundrede f.Kr., at "vores ven Poseidonios for nylig har konstrueret et instrument, som ved hver omdrejning, kan vise solens, månens og de fem planeters bevægelse". Sådanne apparater nævnes også andre steder og støtter formodningen om, at der i antikken var en græsk tradition for kompleks mekanisk teknologi, som senere blev overleveret via den arabiske verden.

Igangværende forskning

Antikythera-mekanismen bliver studeret under The Antikythera Mechanism Research Project,[32] som er et fælles forskningsprogram mellem Cardiff University, the National and Kapodistrian University of Athens, the Aristotle University of Thessaloniki, the National Archaeological Museum of Athens, X-Tek Systems UK[33] og Hewlett-Packard USA, finansieret af Leverhulme Trust og the Cultural Foundation of the National Bank of Greece.

Apparatets undersøgelse forudsatte, at den ikke blev flyttet fra museet, så Hewlett-Packard[34] byggede en 8 tons tung 3D røntgen-scanner omkring mekanismen, kaldet "PTM Dome". Billederne bliver processeret ved at anvende 400kV microfocus computerised tomography.[35]

I juni 2006 blev det annonceret,[36] at man havde fundet 2.000 tegn. Det meste af den græske tekst (95%) har kunnet aflæses. Den leverer et stærkt vidnesbyrd om, at Antikythera-mekanismen må være en astronomicomputer.[37]

Dens kompleksitet er ude af trit med tidligere antagelser om de gamle grækeres tekniske formåen.[38] En teori, som i øjeblikket undersøges er, at Antikythera-mekanismen blev lavet i akademiet grundlagt af den stoiske filosof Poseidonios på den græske ø Rhodos.

Se også

Referencer

  1. ^ Bill Manaris; Andrew R. Brown (19. maj 2014). Making Music with Computers: Creative Programming in Python. CRC Press. s. 4. ISBN 978-1-4822-2221-0. The Antikythera Mechanism-The First Known Computer
  2. ^ Ken Steiglitz (5. februar 2019). The Discrete Charm of the Machine: Why the World Became Digital. Princeton University Press. s. 108. ISBN 978-0-691-18417-3. The Antkythera Mechanism [The first computer worthy of the name...]
  3. ^ Alexander Jones (2017). A Portable Cosmos: Revealing the Antikythera Mechanism, Scientific Wonder of the Ancient World. Oxford University Press. s. 25. ISBN 978-0-19-973934-9. [In the first detailed description of the device in 1903, Perklis Rediadis's] lasting contribution was not to be the identification of the Mechanism as a mechanical counterpart of the astrolabe, which turned out to be wrong, but the general idea that the gears functioned as a device for calculating quantitative data by means of moving parts—that is, an analog computer.
  4. ^ a b Swedin, Eric G.; Ferro, David L. (24. oktober 2007). Computers: The Life Story of a Technology. JHU Press. s. 1. ISBN 978-0-8018-8774-1. Hentet 28. maj 2013. It was a mechanical computer for calculating lunar, solar, and stellar calendars.
  5. ^ Edwin D. Reilly (2003). Milestones in Computer Science and Information Technology. Greenwood Publishing Group. s. 11. ISBN 978-1-57356-521-9.
  6. ^ Dimitris G. Angelakis (2006). Quantum Information Processing: From Theory to Experiment. IOS Press. s. 5. ISBN 978-1-58603-611-9.
  7. ^ Daniel Brunner; Miguel C. Soriano; Guy Van der Sande (8. juli 2019). Photonic Reservoir Computing: Optical Recurrent Neural Networks. De Gruyter. s. 1. ISBN 978-3-11-058349-6.
  8. ^ "Project overview". The Antikythera Mechanism Research Project. Arkiveret fra originalen 21. februar 2011. Hentet 1. juli 2007. The Antikythera Mechanism is now understood to be dedicated to astronomical phenomena and operates as a complex mechanical 'computer' which tracks the cycles of the Solar System.
  9. ^ Seaman, Bill; Rössler, Otto E. (1. januar 2011). Neosentience: The Benevolence Engine. Intellect Books. s. 111. ISBN 978-1-84150-404-9. Hentet 28. maj 2013. Mike G. Edmunds and colleagues used imaging and high-resolution X-ray tomography to study fragments of the Antikythera Mechanism, a bronze mechanical analog computer thought to calculate astronomical positions
  10. ^ Paphitis, Nicholas (30. november 2006). "Experts: Fragments an Ancient Computer". Washington Post. Imagine tossing a top-notch laptop into the sea, leaving scientists from a foreign culture to scratch their heads over its corroded remains centuries later. A Roman shipmaster inadvertently did something just like it 2,000 years ago off southern Greece, experts said late Thursday.
  11. ^ a b Freeth, Tony; Bitsakis, Yanis; Moussas, Xenophon; Seiradakis, John. H.; Tselikas, A.; Mangou, H.; Zafeiropoulou, M.; Hadland, R.; et al. (30. november 2006). "Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism" (PDF). Nature. 444 (7119): 587-91. Bibcode:2006Natur.444..587F. doi:10.1038/nature05357. PMID 17136087. Hentet 20. maj 2014.
  12. ^ Freeth, Tony; Jones, Alexander (2012). "The Cosmos in the Antikythera Mechanism". Institute for the Study of the Ancient World. Hentet 19. maj 2014. {{cite journal}}: Cite journal kræver |journal= (hjælp)
  13. ^ Pinotsis, A. D. (30. august 2007). "The Antikythera mechanism: who was its creator and what was its use and purpose?". Astronomical and Astrophysical Transactions. 26 (4-5): 211-226. Bibcode:2007A&AT...26..211P. doi:10.1080/10556790601136925.
  14. ^ Freeth, Tony; Jones, Alexander; Steele, John M.; Bitsakis, Yanis (31. juli 2008). "Calendars with Olympiad display and eclipse prediction on the Antikythera Mechanism" (PDF). Nature. 454 (7204): 614-7. Bibcode:2008Natur.454..614F. doi:10.1038/nature07130. PMID 18668103. Hentet 20. maj 2014.
  15. ^ Kaplan, Sarah (14 June 2016). "The World's Oldest Computer Is Still Revealing Its Secrets", The Washington Post. Retrieved 16 June 2016.
  16. ^ Paul Iversen, "The Calendar on the Antikythera Mechanism and the Corinthian Family of Calendars, Hesperia 86 (2017): 130 and note 4.
  17. ^ Palazzo, Chiara (17. maj 2017). "What is the Antikythera Mechanism? How was this ancient 'computer' discovered?". The Telegraph. Hentet 10. juni 2017.
  18. ^ Alexander Jones, A Portable Cosmos, Oxford: Oxford University Press, pp. 10–11.
  19. ^ Price, Derek de Solla (1974). "Gears from the Greeks. The Antikythera Mechanism: A Calendar Computer from ca. 80 B. C.". Transactions of the American Philosophical SocietySerier . 64 (7): 1-70. doi:10.2307/1006146. JSTOR 1006146.
  20. ^ Price, Derek de Solla (1974). "Gears from the Greeks. The Antikythera Mechanism: A Calendar Computer from ca. 80 BC" Transactions of the American Philosophical Society, New Series. 64 (7): 19
  21. ^ Carman, Christián C.; Evans, James (15. november 2014). "On the epoch of the Antikythera mechanism and its eclipse predictor". Archive for History of Exact Sciences. 68 (6): 693-774. doi:10.1007/s00407-014-0145-5.
  22. ^ Markoff, John (24. november 2014). "On the Trail of an Ancient Mystery - Solving the Riddles of an Early Astronomical Calculator". The New York Times. Hentet 25. november 2014.
  23. ^ Paul Iversen, "The Calendar on the Antikythera Mechanism and the Corinthian Family of Calendars," Hesperia 86 (2017): 182–183.
  24. ^ Alexander Jones, A Portable Cosmos, Oxford: Oxford University Press, pp. 93, 157-60, 233-46.
  25. ^ "Decoding The Antikythera Mechanism - Investigation of An Ancient Astronomical Calculator". Bibliotecapleyades.net. Hentet 13. november 2012.
  26. ^ Vetenskapens värld: Bronsklumpen som kan förutsäga framtiden. SVT. 17 October 2012. Arkiveret 20. oktober 2012 hos Wayback Machine
  27. ^ Freeth, Tony (2006). "Decoding the Antikythera Mechanism: Supplementary Notes 2" (PDF). Nature. 444 (7119): 587-91. Bibcode:2006Natur.444..587F. doi:10.1038/nature05357. PMID 17136087. Hentet 20. maj 2014.
  28. ^ Sample, Ian. "Mysteries of computer from 65 BC are solved". The Guardian. "This device is extraordinary, the only thing of its kind," said Professor Edmunds. "The astronomy is exactly right ... in terms of historic and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa." and "One of the remaining mysteries is why the Greek technology invented for the machine seemed to disappear."
  29. ^ Marchant, Jo (30. november 2006). "In search of lost time". Nature. 444 (7119): 534-538. Bibcode:2006Natur.444..534M. doi:10.1038/444534a. PMID 17136067.
  30. ^ "The Antikythera Mechanism at the National Archaeological Museum" Arkiveret 21. februar 2017 hos Wayback Machine. Retrieved 8 August 2015.
  31. ^ youtube.com: Lego Antikythera Mechanism
  32. ^ "The Antikythera Mechanism Research Project". Arkiveret fra originalen 5. oktober 2012. Hentet 8. juni 2006.
  33. ^ "X-Tek Systems UK". Arkiveret fra originalen 27. juni 2006. Hentet 8. juni 2006.
  34. ^ "research team". Arkiveret fra originalen 30. august 2012. Hentet 8. juni 2006.
  35. ^ "400kV microfocus computerised tomography". Arkiveret fra originalen 18. juni 2006. Hentet 8. juni 2006.
  36. ^ General Science : June 06, 2006: Researchers find hidden Greek text on 'world's oldest astronomy computer' Citat: "..."Part of the text on the machine, over 1,000 characters, had already been deciphered, but we have succeeded in doubling this total," said physician Yiannis Bitsakis..."We have now deciphered 95 percent of the text," he told AFP. .."
  37. ^ Nature 444, 587-591 (30 November 2006): Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism Citat: "...The mechanism predicted lunar and solar eclipses on the basis of Babylonian arithmetic-progression cycles. The inscriptions support suggestions of mechanical display of planetary positions, now lost..."
  38. ^ 24 November 2010, nature.com: Ancient astronomy: Mechanical inspiration Citat: "...If correct, this interpretation suggests that the astronomy encoded in the mechanism's gearwork does not represent state-of-the-art Greek theories after all. It is Babylonian through and through...Evans argues that even the clearly epicyclic gearing of the Moon display may model Babylonian arithmetic, not Greek geometry. The amplitude of the variation encoded by the pin-and-slot mechanism is larger than that used by Hipparchus in his eccentric model, he points out, and is closer to the amplitude used in the lunar algorithms of the Babylonians...There is little evidence for who came up with the idea of epicycles, although it is often ascribed to third-century-BC Greek geometer Apollonius of Perga. Intriguingly, gears and epicycles seem to have arisen at about the same time, with gears perhaps a little earlier. Also in the third century BC..."

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NAMA Machine d'Anticythère 6.jpg
Forfatter/Opretter: No machine-readable author provided. Marsyas assumed (based on copyright claims)., Licens: CC BY 2.5
Replica of the Antikythera Instrument: Based on the research of Professor Derek de Solla Price, in collaboration with the National Scientific Research Center "Demokritos" and physicist CH Karakalos who carried out the x-ray tomography of the original. This mechanism has been rebuilt to show the likely operation of the original. Price built a rectangular box of 33 cm X 17 cm X 10 cm with protective plates bearing Greek inscriptions of planets and operational information. The mechanism is a complex set of 32 gears of various sizes, turning at different speeds. The mechanism was offered by Prof. Price to the National Museum in 1980 and remains the reference for the study of the original despite the fact that its construction has been subject to much criticism. National archaeological museum, Athens, number BE 109/1980.
Antikythera mechanism.svg
This is an SVG version of the schematic for the Antikythera mechanism based on the file:Meccanismo_di_Antikytera.jpg
NAMA Machine d'Anticythère 1.jpg
Forfatter/Opretter: No machine-readable author provided. Marsyas assumed (based on copyright claims)., Licens: CC BY 2.5
Main w:en:Antikythera mechanism fragment (fragment A). The mechanism consists of a complex system of 30 wheels and plates with inscriptions relating to signs of the zodiac, months, eclipses and pan-Hellenic games. The study of the fragments suggests that this was a kind of astrolabe. The interpretation now generally accepted dates back to studies by Professor w:en:Derek de Solla Price, who was the first to suggest that the mechanism is a machine to calculate the solar and lunar calendar, that is to say, an ingenious machine to determine the time based on the movements of the sun and moon, their relationship (eclipses) and the movements of other stars and planets known at that time. Later research by the Antikythera Mechanism Research Project and scholar Michael Wright has added to and improved upon Price's work.
The mechanism was probably built by a mechanical engineer of the school of Posidonius in Rhodes. Cicero, who visited the island in 79/78 B.C. reported that such devices were indeed designed by the Stoic philosopher Posidonius of Apamea. The design of the Antikythera mechanism appears to follow the tradition of Archimedes' planetarium, and may be related to sundials. His modus operandi is based on the use of gears. The machine is dated around 89 B.C. and comes from the wreck found off the island of Antikythera. National Archaeological Museum, Athens, No. 15987.