The Antikythera mechanism (/ˌæntɪkɪˈθɪərə/ AN-tih-kih-THEER-ə) 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 which was similar to an Olympiad, the cycle of the ancient Olympic Games.
While the device itself may have struggled with inaccuracies due to the triangular teeth being hand-made, the calculations used and the technology implemented to create the elliptical paths of the planets and retrograde motion of the Moon and Mars by using a clockwork-type gear train with the addition of a pin-and-slot epicyclic mechanism predated that of the first known clocks found in antiquity in Medieval Europe by more than 1000 years. Archimedes' development of the approximate value of pi and his theory of centres of gravity, along with the steps he made towards developing the calculus, all suggest that the Greeks had access to more than enough mathematical knowledge beyond that of just Babylonian algebra in order to be able to model the elliptical nature of planetary motion.
Cicero's De re publica (54-51 BC), a first century BC philosophical dialogue, mentions two machines that some modern authors consider as some kind of planetarium or orrery, predicting the movements of the Sun, the Moon, and the five planets known at that time. They were both built by Archimedes and brought to Rome by the Roman general Marcus Claudius Marcellus after the death of Archimedes at the siege of Syracuse in 212 BC. Marcellus had great respect for Archimedes and one of these machines was the only item he kept from the siege (the second was placed in the Temple of Virtue). The device was kept as a family heirloom, and Cicero has Philus (one of the participants in a conversation that Cicero imagined had taken place in a villa belonging to Scipio Aemilianus in the year 129 BC) saying that Gaius Sulpicius Gallus (consul with Marcellus's nephew in 166 BC, and credited by Pliny the Elder as the first Roman to have written a book explaining solar and lunar eclipses) gave both a "learned explanation" and a working demonstration of the device.
I had often heard this celestial globe or sphere mentioned on account of the great fame of Archimedes. Its appearance, however, did not seem to me particularly striking. There is another, more elegant in form, and more generally known, moulded 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, by his sublime science, the composition of this machine, I felt that the Sicilian geometrician must have possessed a genius superior to any thing we usually conceive to belong to our nature. Gallus assured us, that the solid and compact globe, was a very ancient invention, and that the first model of it had been presented by Thales of Miletus. That afterwards Eudoxus of Cnidus, a disciple of Plato, had traced on its surface the stars that appear in the sky, and that many years subsequent, borrowing from Eudoxus this beautiful design and representation, Aratus had illustrated them in his verses, not by any science of astronomy, but the ornament of poetic description. He added, that the figure of the sphere, 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.When Gallus moved this globe, it showed the relationship of the Moon with the Sun, and there were exactly the same number of turns on the bronze device as the number of days in the real globe of the sky. Thus it showed the same eclipse of the Sun as in the globe [of the sky], as well as showing the Moon entering the area of the Earth's shadow when the Sun is in line ... [missing text] [i.e. It showed both solar and lunar eclipses.]
But what the sponge divers found was anything but usual: the pieces of a device of sorts, consisting of thirty bronze gears and dozens of smaller parts and fragments encrusted with rust and corrosion. What has become known as the Antikythera Mechanism was a mystery even to the curators who put it on display in the archaeological museum in Athens.
The inscription turned out to be a kind of user's manual, enabling the team to determine that the thirty hand-cut bronze gears and dials (originally housed in a wooden frame) formed an analog computer most likely used to plot the orbits of the planets, predict eclipses, and affix the date for the quadrennial Olympic games. The inscriptions include the names of the planets and the signs of the zodiac, plus the word Ispania, the oldest known text reference to Spain. Based on the form of the Greek letters on the device, Moussas estimated it was constructed during the first half of the first century BC, making it what is now thought of as the earliest known computer.
In the university, Atanasoff started to make various experiments with vacuum tubes and radio signals as well as various electronic devices and was really determined to develop an advanced computing machine. In the mean time he was promoted to an associate-professor in physics and mathematics.
The ABC computer was the first electronic digital computing device. It was designed with a specific purpose, to solve systems of simultaneous up to 29 linear equations. The machine exact operation was to accept two linear equations at a time with up to 29 variables and a constant, using this data it could eliminate one of the variables. Following this way, the machine could continue by eliminating each time one variable, until the entire system of equations was solved.
"John Atanasoff met John Mauchly at the December 1940 meeting of the American Association for the Advancement of Science in Philadelphia, where Mauchly was demonstrating his "harmonic analyzer". This was an analog calculator for analysis of weather data. Atanasoff told Mauchly about his new digital device and invited him to see it. Also during the Philadelphia trip, Atanasoff and Berry visited the patent office in Washington, where their research assured them that their concepts were new. A January 15, 1941 story in the Des Moines Register announced the ABC as "an electrical computing machine" with more than 300 vacuum tubes that would "compute complicated algebraic equations. In June 1941 Mauchly visited Atanasoff in Ames, Iowa to see the ABC. During his four day visit as Atanasoff's houseguest, Mauchly thoroughly discussed the prototype ABC, examined it, and reviewed Atanasoff's design manuscript in detail. Up to this time Mauchly had not proposed a digital computer. In September 1942 Atanasoff left Iowa State for a wartime assignment as Chief of the Acoustic Division with the Naval Ordnance Laboratory (NOL) in Washington D.C. He entrusted his patent application for the ABC to Iowa State College administrators. It was never filed. Mauchly visited Atanasoff multiple times in Washington during 1943 and discussed Atanasoff's computing theories, but did not mention that he was working on a computer project himself until early 1944. (Mollenhoff, p. 62-66). John Mauchly and J. Presper Eckert's construction of ENIAC, the first general purpose electronic computer, during 1943-1946 was to lead to a legal dispute two decades later over who was the actual inventor of the computer.
The first mobile device that incorporated both communication and computing features was the Blackberry, which was introduced in 2002.5 After the Blackberry was brought to market, other handheld mobile devices were introduced. Perhaps most notably, in January 2007, Apple launched the first-generation iPhone.5 Subsequently, smartphones that run the Google Android operating system were introduced in October 2008.5 Because of the intuitive touch-screen user interfaces and advanced features and capabilities that the iPhone and Android smartphones offer, ownership of mobile devices has increased rapidly.12 In April 2010, Apple introduced a new innovation, the iPad tablet computer, which because of ease of use, portability, and a comparatively large screen was yet another transformative computing tool.5 The iPad ignited the tablet computer market.9 Tablets that run the Google Android operating system (Samsung Galaxy and others) were launched later that year, making the use of these mobile devices even more widespread.5
Without a doubt, medicine is one of the disciplines that has been profoundly affected by the availability of mobile devices.4 This is evident in many surveys of HCPs that reveal a high ownership rate of these tools, which HCPs use in both clinical practice and education.2 Smartphones and tablets have even replaced desktop systems as the preferred computing devices for HCPs who need fast access to information at the point of care.9
Although the vast majority of the computers that we know about today were created within the past 100 years, human ingenuity dates back further than many of us can likely imagine. To help put this in perspective, here are the 10 oldest known computers. In the event of later models which were introduced by the same manufacturer, some models were taken off of this list to allow for a more diverse group of machines.
If you are new to the history of computers, some of the below systems will blow your mind. The oldest computer in known history is actually a lot more ancient than most of us would have previously imagined. Just keep in mind that many different exact dates and models, along with their inventors may have also been lost in history.
James Thomson, brother of Lord Kelvin, invented the mechanicalwheel-and-disc integrator that became the foundation of analogcomputation (Thomson ). The two brothers constructed a device forcomputing the integral of the product of two given functions, andKelvin described (although did not construct) general-purpose analogmachines for integrating linear differential equations of any order andfor solving simultaneous linear equations. Kelvin's most successfulanalog computer was his tide predicting machine, which remained in useat the port of Liverpool until the 1960s. Mechanical analog devicesbased on the wheel-and-disc integrator were in use during World War Ifor gunnery calculations. Following the war, the design of theintegrator was considerably improved by Hannibal Ford (Ford ). 2b1af7f3a8