An orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model. It may also represent the relative sizes of these bodies; however, since accurate scaling is often not practical due to the actual large ratio differences, a subdued approximation may be used instead. The Greeks had working planetaria, but the first that was a planetarium of the modern era was produced c. 1712 by John Rowley. He named it orrery for Charles Boyle, 4th Earl of Orrery. The plaque on it reads "Orrery invented by Graham 1700 improved by Rowley and presented by him to John [sic] Earl of Orrery after whom it was named by at the suggestion of Richard Steele."
The Antikythera mechanism is an Ancient Greek hand-powered orrery, described as the oldest known example of an analogue computer used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games similar to an Olympiad, the cycle of the ancient Olympic Games.
A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others. A common use of differentials is in motor vehicles, to allow the wheels at each end of a drive axle to rotate at different speeds while cornering. Other uses include clocks and analogue computers. Differentials can also provide a gear ratio between the input and output shafts. For example, many differentials in motor vehicles provide a gearing reduction by having fewer teeth on the pinion than the ring gear.
Derek John de Solla Price was a British physicist, historian of science, and information scientist. He was known for his investigation of the Antikythera mechanism, an ancient Greek planetary computer, and for quantitative studies on scientific publications, which led to his being described as the "Herald of scientometrics".
Meton of Athens was a Greek mathematician, astronomer, geometer, and engineer who lived in Athens in the 5th century BC. He is best known for calculations involving the eponymous 19-year Metonic cycle, which he introduced in 432 BC into the lunisolar Attic calendar. Euphronios says that Colonus was Meton's deme.
Diane Rehm is an American journalist and the host of Diane Rehm: On My Mind podcast, produced at WAMU, which is licensed to American University in Washington, D.C.. She also hosts a monthly book club series, Diane Rehm Book Club, at WAMU. Rehm is the former American public radio talk show host of The Diane Rehm Show, which was distributed nationally and internationally by National Public Radio. The show was produced at WAMU.
Callippus was a Greek astronomer and mathematician.
Antikythera or Anticythera, known in antiquity as Aigilia (Αἰγιλία), is a Greek island lying on the edge of the Aegean Sea, between Crete and Peloponnese. Since the 2011 local government reform, it is part of the municipality of Kythira island.
Allan George Bromley was an Australian historian of computing who became a world authority on many aspects of early computing and was one of the most avid collectors of mechanical calculators.
The Antikythera wreck is a Roman-era shipwreck dating from the second quarter of the first century BC.
An astrarium, also called a planetarium, is a medieval astronomical clock made in the 14th century by Italian engineer and astronomer Giovanni Dondi dell'Orologio. The Astrarium was modeled after the solar system and, in addition to counting time and representing calendar dates and holidays, showed how the planets moved around the celestial sphere in one timepiece. This was its main task, in comparison with the astronomical clock, the main task of which is the actual reading of time. A complex mechanism, it combined the functions of a modern planetarium, clock, and calendar into a singular constructive device. Devices that perform this function were known to have been created prior to the design of Dondi, though relatively little is known about them. It is occasionally erroneously claimed by the details of some sources that the Astrarium was the first mechanical device showing the movements of the planets.
The Antikythera Ephebe, registered as Bronze statue of a youth in the museum collections, is a Greek bronze statue of a young man of languorous grace that was found in 1900 by sponge-divers in the area of the ancient Antikythera shipwreck off the island of Antikythera, Greece. It was the first of the series of Greek bronze sculptures that the Aegean and Mediterranean yielded up in the twentieth century which have fundamentally altered the modern view of ancient Greek sculpture. The wreck site, which is dated about 70–60 BC, also yielded the Antikythera mechanism, a characterful head of a Stoic philosopher, and a hoard of coins. The coins included a disproportionate quantity of Pergamene cistophoric tetradrachms and Ephesian coins, leading scholars to surmise that it had begun its journey on the Ionian coast, perhaps at Ephesus; none of its recovered cargo has been identified as from mainland Greece.
Ancient Discoveries is a television series that premiered on December 21, 2003, on the History Channel. The program focused on ancient technologies. The show's theme was that many inventions which are thought to be modern have ancient roots or in some cases may have been lost and then reinvented. The program was a follow-up to a special originally broadcast in 2005 which focused on technologies from the Ancient Roman era such as the Antikythera mechanism and inventors such as Heron of Alexandria. Episodes of the regular series expanded to cover other areas such as Egypt, China and East Asia, and the Islamic world.
The concept of engineering has existed since ancient times as humans devised fundamental inventions such as the pulley, lever, and wheel. Each of these inventions is consistent with the modern definition of engineering, exploiting basic mechanical principles to develop useful tools and objects.
Michael T. Wright, FSA is a former curator of mechanical engineering at the Science Museum and later at Imperial College in London, England. He is known for his analysis of the original fragments of the Antikythera mechanism and for the reconstruction of this Ancient Greek brass mechanism.
Jo Marchant is a freelance journalist specializing in science and history. After gaining a BSc in genetics from Leicester University and a PhD in microbiology she became a science writer, and is the author of Decoding the Heavens, an exploration of the history and significance of the Antikythera mechanism, The Shadow King: The Bizarre Afterlife of King Tut's Mummy and Cure: A Journey Into the Science of Mind Over Body(shortlisted for the Royal Society Insight Investment Science Book Prize 2016). A former editor of the science journal Nature and opinion editor at New Scientist magazine in London, she has written for The Guardian and The Economist.
Rehm is a surname, and may refer to:
Adolf Wilhelm was an Austrian classical philologist and epigrapher.
Mike (Michael) Edmunds FAS FInstP FLSW is a British astrophysicist, known for his research on the interpretation of the chemical composition of the Universe and the origin of interstellar dust.
John Seiradakis was a Greek astronomer and professor emeritus at the Department of Physics of the Aristotle University of Thessaloniki. He is best known for his contributions in the understanding of radio pulsars, the Galactic Center and archaeoastronomy. Since the early 2000s he was heavily involved in the decoding of the Antikythera mechanism. He was a founding member of the Hellenic Astronomical Society, the European Astronomical Society and the International Olympiad on Astronomy and Astrophysics (IOAA).
