Antikythera mechanism

This work analyzes the phase correlation of the three lunar cycles and the Saros/Exeligmos cycle, after the study of the chapter "About Exeligmos" in "Introduction to the Phenomena" by Geminus. The main result is that each Exeligmos/Saros Cycle began on specific, rare dates directly related to a specific phase of the three lunar cycles. The Annular Solar eclipse on December 22 th 178BC belonging to Saros series 58, marks the start of the "Prominent Saros Cycle Apokatastasis", analyzed in this paper. After the analysis of the two Parapegma plates position on Antikythera Mechanism Front plate, the date of Winter Solstice/December 23 rd 178BC could be considered as the probable date of the start of the Mechanism Metonic dial. This date is directly correlated to the Exeligmos/Saros specific dates. During these two neighboring dates, the religious festival of Isia was celebrated in Egypt and the Hellenistic Greece. The correlation of these results, lead to the calculation of the initial calibration date/pointers position which is ideal, functional and representative for the specific design of the Antikythera Mechanism.

Decoding the Antikythera Mechanism: Mystery of the Ancient World provides a detailed look at The Antikythera Mechanism, an Ancient Greek mechanical device described as the “oldest example of an analogue computer”. The chapters delve into the discovery of the Antikythera Mechanism, its mechanism of action, and its importance today. The book was written under the guidance of Dr. Austin Mardon, recipient of the Order of Canada.

The unplaced Fragment D of the Antikythera Mechanism with an unknown operation was a mystery since the beginning of its discovery. The gear-r1, which was detected on the Fragment radiographies by C. Karakalos, is preserved in excellent condition, but this was not enough to correlate it to the existing gear trainings of the Mechanism. The suggestion that this gear could be a part of the hypothetical planet indication gearing is still a hypothesis since no mechanical evidence has been preserved. After the analysis of AMRP tomographies of Fragment D and its mechanical characteristics revealed that it could be part of the Draconic gearing. Although the Draconic cycle was well known during the Mechanism’s era as represents the fourth Lunar cycle, it seems that it is missing from the Antikythera Mechanism. The study of Fragment D was supported by the bronze reconstruction of the Draconic gearing by the authors. The adaptation of the Draconic gearing on the Antikythera Mechanism improves its functionality and gives answers on several questions.

After a careful examination of the Antikythera Mechanism CT scans from AMRP, we designed and constructed the mechanical parts that are visible on the scans. We then reconstructed two functional models of the Antikythera mechanism and in this paper we present the observations and the conclusions drawn from their use. The use of these models helped us to understand how the mechanism worked and provided answers in questions regarding the presence and the use of some parts.

The word 'Geocentric' comes from the Greek word Γεωκεντρικό which is a compound word composed from two words: "γεω" means Earth and "κεντρικό" means centric. Geocentric aspect, appears for the first time in ancient Greece. Pythagoras had formulated the geocentric system with the Earth at the center of the Universe surrounded by the orbiting planets with Sun included. Later Greek ancient astronomers, trying to explain the weird planetary motion in the sky, introduced the epicyclic theory. 3 This theory states that the geocentric planetary motion could be considered as a combination of circular motions. Today this idea is quite sensible if we consider that the geocentric motion could be perceived as synthesis of two independent motions; one is the rotation of the planet around the Sun and the other is the apparent rotation of the Sun around the Earth. Someone could say that the heliocentric motion is hidden inside the geocentric planetary path as one of two superimposed motions. This logical conclusion is supported by F. Hoyle Hoyle (1975) who states "We know that the difference between a heliocentric theory and a geocentric theory is one of relative motion only, and that such a difference has no physical significance." In other words Geocentrism isn't completely wrong excluding only the arbitrary claim that the Earth is fixed and immobile at the center of the Universe. Geocentrism lasted many years until Nicolaus Copernicus at the middle of 15th century, proposed the he-liocentric system by transferring the reference origin from Earth to Sun. Although Copernican model was capable explaining the geocentric orbits of planets with negligible eccentricity, it failed to give a convincing explanation in cases of planets with considerable eccentricity like Mars. The lack of symmetry in Mar's trajectory led Kepler to discover that planet's orbits weren't circular, as it was already believed, but elliptical. According to (Evans, 1998, p.431) Kepler said "I therefore once again think it to have happened by divine arrangement, that I arrived at the same time in which he was intent upon Mars, whose motions provide the only possible access to the hidden secrets of astronomy, without which we would remain forever ignorant of those secrets." In this article we are trying to simulate the process followed by Kepler, studying the apparent geocentric Mar's orbit which triggered him to discover elliptical planetary orbits. The relation between heliocentrism and geocentrism is highlighted during this study. Besides, this aspect is mentioned by David R. Topper...But this fact is then sometimes generalized to positing that geocentrism and Heliocentrism are equivalent, that they are the same geometrically or mathematically or even exactly the same; in a phrase, there is an isomorphism between them... Topper (2007) The methodology which was used, in the whole process, relies on mathematical modeling. This approach is based mainly on dynamic position change over time, which the interactive mathematic software GeoGebra can generously provide. The end of this historical approach shows that the heliocentric view was revealed throughout a geocentric model, proving the equivalence of these two different aspects. Finally the theoretical numerical results of this study seem to be in full agreement with the astronomical records of that era with minimal discrepancies.

The Antikythera Mechanism is the oldest known advanced scientific instrument. Without doubt, it is the oldest known analogue computer made with gears and the first known Mechanical Universe and probably Planetarium. Not only was an astronomical instrument suitable for observations, but it also served as a climatological and meteorological device. Certainly, such devices were in use as educational instruments in Antiquity and possibly operated as a cartographic tool. Made by Greek scientists with appropriate knowledge of astronomy, mathematics, physics, engineering and metallurgy, the bronze geared device enabled the constructor to perform specific calculations with gear trains and the user to find the position of celestial bodies in the sky. It was constructed during the Hellenistic period, probably around 150 to 100 BC. The Antikythera Mechanism depicts the position of the Sun, the Moon (its phase), predicts eclipses and shows when the Greek Crown Games should occur: the Olympics, the Pythian, the Isthmian, the Nemean, the Naan, some of the very important festivities that enable the common person to keep the time in a functional calendar very useful in agricultural, fishing and hunting.

The Antikythera Mechanism is the most extraordinary example of Greek technological development and expertise known from antiquity. This amazing piece of geared technology could best be described as a complex mechanical computer dated to the second century before Christ which tracks and predicts various cycles of the Sun and the Moon. One of the major questions concerning the mechanism that has puzzled scholars for over one century now is whether the motions of the planets were also predicted by the device. Though many clues have been discovered, no direct evidence has been found in the surviving fragments of the Antikythera Mechanism. This article describes our work in analyzing the various possibilities for a planetary extension. Different ways in which the positions of the planets could have been represented on the mechanism are explored and we focus on one of these ways on the basis of actual computer reconstructions.

Time has always held a fascination for human beings, who have attempted to relate to it and to make sense of it, constructing and deconstructing it through its various prisms, since time cannot be experienced in an unmediated way. This book answers the needs of a growing community of scholars and readers who are interested in this interaction. It offers a series of innovative studies by both senior and younger experts on various aspects of the construction of time in antiquity. Some articles in this book contain visual material published for the first time, while other studies update the field with new theories or apply new approaches to relevant sources. Within the study of antiquity, the book covers the disciplines of Classics and Ancient History, Assyriology, Egyptology, Ancient Judaism, and Early Christianity, with thematic contributions on rituals, festivals, astronomy, calendars, medicine, art, and narrative.

Contents:
1. Introduction Lutz Doering and Jonathan Ben-Dov
2 Time and natural law in Jewish-Hellenistic writings Jonathan Ben-Dov
3. Calendars, politics, and power relations in the Roman Empire Sacha Stern
4. Doubling religion in the Augustan Age: shaping time for an empire Jörg Rüpke
5. Real and constructed time in Babylonian astral medicine John Steele
6. The intellectual background of the Antikythera mechanism Robert Hannah
7. Divine figurations of time in Ancient Egypt Alexandra von Lieven
8. The moon and the power of time reckoning in Ancient Mesopotamia Lorenzo Verderame
9. Toward a phenomenology of time in ancient Greek art SeungJung Kim
10. Women's bodies as metaphors for time in biblical, second temple, and rabbinic literature Sarit Kattan Gribetz
11. The beginning of sabbath and festivals in ancient Jewish sources Lutz Doering
12. Seasoning the bible and biblifying time through fixed liturgical reading systems (lectionaries) Daniel Stökl Ben Ezra
13. The Roman ember days of September and the Jewish New Year Robert Hayward
14. Celebrations and the abstention from celebrations of sacred time in Early Christianity Clemens Leonhard.

The present study aims to investigate the astronomical calendar-dial display of the Antikythera Mechanism Front Plate. The design, position and role of the Zodiac ring, are investigated and discussed. Special photographs taken from the ancient prototype, give us new information about the design and operation of the front dial. From these new findings about the Zodiac ring, we conclude that the user of the mechanism was able to easily perform astronomical calculations at any selected time - of past or future date. Based on the new findings during ‘’The Functional Reconstruction of Antikythera Mechanism Project’’ (FRAMe), we reconstructed the new bronze front plate and we placed it in our functional model of the Antikythera Mechanism.