Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2023 July 23 [2]An old and corroded mechanism is shown fronted by a large wheel. The mechanism has patches of tan and brown color but it is mostly green. Please see the explanation for more detailed information. The Antikythera Mechanism Image Credit & [3]License: [4]Marsyas, [5]Wikipedia Explanation: It does what? No one knew that 2,000 years ago, the technology existed to build such a device. The [6]Antikythera mechanism, pictured, is now widely regarded as the [7]first [8]computer. Found at the bottom of the sea aboard a decaying [9]Greek ship, its complexity prompted decades of study, and even today some of its functions likely [10]remain unknown. [11]X-ray images of the device, however, have confirmed that a main function of its numerous clock-like [12]wheels and gears is to create a portable, hand-cranked, Earth-centered, [13]orrery of the sky, predicting future star and planet locations as well as [14]lunar and [15]solar eclipses. The corroded core of the [16]Antikythera mechanism's largest gear is featured, spanning about 13 centimeters, while the [17]entire mechanism was 33 centimeters high, making it similar in size to a large book. Recently, [18]modern computer modeling of missing components is allowing for the creation of a more complete replica of this [19]surprising ancient machine. Tomorrow's picture: rainbow meteor __________________________________________________________________ [20]< | [21]Archive | [22]Submissions | [23]Index | [24]Search | [25]Calendar | [26]RSS | [27]Education | [28]About APOD | [29]Discuss | [30]> __________________________________________________________________ Authors & editors: [31]Robert Nemiroff ([32]MTU) & [33]Jerry Bonnell ([34]UMCP) NASA Official: Phillip Newman [35]Specific rights apply. [36]NASA Web Privacy Policy and Important Notices A service of: [37]ASD at [38]NASA / [39]GSFC, [40]NASA Science Activation & [41]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2307/antikythera_wikipedia_960.jpg 3. https://creativecommons.org/licenses/by-sa/3.0/deed.en 4. https://commons.wikimedia.org/wiki/User:Marsyas 5. https://commons.wikimedia.org/wiki/File:NAMA_Machine_d'Anticythère_1.jpg 6. https://en.wikipedia.org/wiki/Antikythera_mechanism 7. https://en.wikipedia.org/wiki/Computer#Pre-20th_century 8. https://www.smithsonianmag.com/history/decoding-antikythera-mechanism-first-computer-180953979/ 9. https://en.wikipedia.org/wiki/Greece 10. https://cdn.shopify.com/s/files/1/0530/4500/2416/articles/confused-dog-featured-126785.jpg 11. https://science.nasa.gov/ems/11_xrays 12. https://youtu.be/RLPVCJjTNgk 13. https://youtu.be/tmNuG15cqNw?t=410 14. https://apod.nasa.gov/apod/ap190120.html 15. https://apod.nasa.gov/apod/ap170912.html 16. http://www.antikythera-mechanism.gr/ 17. https://youtu.be/UpLcnAIpVRA 18. https://www.nature.com/articles/s41598-021-84310-w 19. https://www.bbc.com/news/science-environment-56377567 20. https://apod.nasa.gov/apod/ap230722.html 21. https://apod.nasa.gov/apod/archivepix.html 22. https://apod.nasa.gov/apod/lib/apsubmit2015.html 23. https://apod.nasa.gov/apod/lib/aptree.html 24. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 25. https://apod.nasa.gov/apod/calendar/allyears.html 26. https://apod.nasa.gov/apod.rss 27. https://apod.nasa.gov/apod/lib/edlinks.html 28. https://apod.nasa.gov/apod/lib/about_apod.html 29. https://asterisk.apod.com/discuss_apod.php?date=230723 30. https://apod.nasa.gov/apod/ap230724.html 31. http://www.phy.mtu.edu/faculty/Nemiroff.html 32. http://www.phy.mtu.edu/ 33. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 34. http://www.astro.umd.edu/ 35. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 36. https://www.nasa.gov/about/highlights/HP_Privacy.html 37. https://astrophysics.gsfc.nasa.gov/ 38. https://www.nasa.gov/ 39. https://www.nasa.gov/centers/goddard/ 40. https://science.nasa.gov/learners 41. http://www.mtu.edu/