Who is Aristarchus of Samos? What is he famous for? You will find answers to these and other questions in the article. Aristarchus of Samos is an ancient Greek astronomer. He is a philosopher and mathematician of the 3rd century BC. e. Aristarchus developed a scientific technology for finding the distances to the Moon and the Sun and their sizes, and also for the first time proposed a heliocentric world system.
Biography
What is the biography of Aristarchus of Samos? There is very little information about his life, like about most other astronomers of antiquity. It is known that he was born on the island of Samos. His exact years of life are unknown. Literature usually indicates the period 310 BC. e. - 230 BC e., which is established on the basis of indirect information.
Ptolemy claimed that Aristarchus in 280 BC. e. watched the solstice. This evidence is the only authoritative date in the astronomer's biography. Aristarchus studied with an outstanding philosopher, a representativethe peripatetic school of Strato of Lampascus. Historians suggest that for a long time Aristarchus worked at the Hellenistic scientific center in Alexandria.
When the heliocentric system of the world was put forward by Aristarchus of Samos, he was accused of atheism. No one knows what this accusation led to.
Buildings of Aristarchus
What discoveries did Aristarchus of Samos make? Archimedes in his work "Psammit" provides brief data on the astronomical system of Aristarchus, which was presented in a work that has not come down to us. Like Ptolemy, Aristarchus believed that the movements of the planets, the Moon and the Earth, take place inside the sphere of immovable stars, which, according to Aristarchus, is motionless, like the Sun, located in its center.
He claimed that the Earth moves in a circle, in the middle of which the Sun is located. The constructions of Aristarchus are the highest achievement of the heliocentric doctrine. It was their courage that brought on the author the accusation of apostasy, as we discussed above, and he was forced to leave Athens. The only small work of the great astronomer "On the distances and sizes of the Moon and the Sun", which was first published in Oxford in the original language in 1688, has survived.
World order
What is interesting about the views of Aristarchus of Samos? When they study the history of the development of mankind's views on the structure of the Universe and the place of the Earth in this structure, they always remember the name of this ancient Greek scientist. Like Aristotle, he gavepreference for the spherical structure of the universe. However, unlike Aristotle, he did not put the Earth at the center of the universal movement in a circle (like Aristotle), but the Sun.
In the light of current knowledge about the world, we can say that among the ancient Greek researchers, Aristarchus came closest to the real picture of the organization of the world. Nevertheless, the structure of the world he proposed did not become popular in the scientific community of that time.
Heliocentric construction of the world
What is the heliocentric construction of the world (heliocentrism)? This is the view that the Sun is the celestial central body around which the earth and other planets revolve. It is the opposite of the geocentric construction of the world. Heliocentrism appeared in antiquity, but became popular only in the 16th-17th centuries.
In the heliocentric construction, the Earth is represented as rotating around its own axis (the revolution is completed in one sidereal day) and at the same time - around the Sun (the revolution is performed in one sidereal year). The result of the first movement is the visible rotation of the celestial sphere, the result of the second is the annual movement of the Sun along the ecliptic among the stars. Relative to the stars, the Sun is considered immovable.
Geocentrism is the belief that the Earth is the center of the universe. This world construct was the dominant theory throughout Europe, ancient Greece and elsewhere for centuries. In the 16th century, the heliocentric construction of the world began to gain prominence asthe industry evolved in order to get more arguments in its favor. The priority of Aristarchus in its creation was recognized by the Copernicans Kepler and Galileo.
On the distances and magnitudes of the Moon and the Sun
So, you already know that Aristarchus of Samos believed that the center of the Universe is the Sun. Consider his well-known work "On the distances and magnitudes of the Moon and the Sun", in which he tries to establish the distance to these celestial bodies and their parameters. Ancient scholars of Greece spoke on these topics more than once. So, Anaxagoras of Klazomen argued that the Sun is larger than the Peloponnese in parameters.
But all these judgments were not scientifically substantiated: the parameters of the Moon and the Sun and the distances were not calculated on the basis of any observations of astronomers, but simply invented. But Aristarchus of Samos used a scientific method based on the observation of lunar and solar eclipses and lunar phases.
Its formulations are based on the hypothesis that the Moon receives light from the Sun and looks like a ball. From which it follows that if the Moon is placed in a quadrature, that is, cut in half, then the angle Sun - Moon - Earth is right.
Now the angle between the Sun and the Moon α is measured, and by “solving” a right-angled triangle, you can set the ratio of the distances from the Moon to the Earth. According to Aristarchus' measurements, α=87°. As a result, it turns out that the Sun is almost 19 times farther than the Moon. There were no trigonometric functions in antiquity. Therefore, to calculate this distance, he used very intricate calculations, in detaildescribed in the essay we are considering.
Next, Aristarchus of Samos drew some data on solar eclipses. He clearly imagined that they happen when the Moon blocks the Sun from us. Therefore, he indicated that the angular parameters of these luminaries in the sky are approximately identical. It follows from this that the Sun is as many times larger than the Moon as it is farther away, that is (according to Aristarchus) the ratio of the radii of the Moon and the Sun is approximately equal to 20.
Then Aristarchus tried to measure the ratio of the parameters of the Moon and the Sun to the size of the Earth. This time he drew on the analysis of lunar eclipses. He knew that they occur when the moon is in the cone of the earth's shadow. He determined that in the zone of the Moon's orbit, the width of this cone is twice the diameter of the Moon. Further, Aristarchus concluded that the ratio of the radii of the Earth and the Sun is less than 43 to 6, but more than 19 to 3. He also estimated the radius of the Moon: it is almost three times less than the earth's radius, which is almost identical to the correct value (0, 273 Earth radii).
The scientist underestimated the distance to the Sun by about 20 times. In general, his method was rather imperfect, unstable to errors. But this was the only way available in antiquity. Also, contrary to the title of his work, Aristarchus does not calculate the distance from the Sun to the Moon, although he could easily do this, knowing their linear and angular parameters.
The work of Aristarchus is of great historical significance: it was from him that astronomers began to study the “third coordinate”, during which the scales of the Universe, the PathMilky and solar system.
Calendar improvements
You already know the years of life of Aristarchus of Samos. He was a great man. So, Aristarchus influenced the updating of the calendar. The Censorinus (3rd century AD writer) pointed out that Aristarchus set the length of the year at 365 days.
Besides, the great scientist put into use a calendar span of 2434 years. Many historians argue that this interval was a derivative of a several times larger cycle of 4868 years, which is called the "Great Year of Aristarchus."
In the Vatican lists, Aristarchus is chronologically the first astronomer for whom two different values of the length of the year were created. These two types of year (sidereal and tropical) are not equal to each other due to the precession of the earth's axis, in accordance with the traditional opinion discovered by Hipparchus a century and a half after Aristarchus.
If Rawlins' reconstruction of the Vatican lists is correct, then the distinction between sidereal and tropical years was first identified by Aristarchus, who should be considered the precession detector.
Other works
It is known that Aristarchus is the creator of trigonometry. He, according to Vitruvius, modernized the solar clock (he also invented a solar flat clock). In addition, Aristarchus studied optics. He thought that the color of objects appears when light falls on them, that is, that paints have no color in the dark.
Many believe that he experimented onidentifying the resolving susceptibility of the human eye.
Meaning and memory
Contemporaries understood that the works of Aristarchus were of outstanding importance. His name has always been named among the famous mathematicians of Hellas. The work "On the distances and magnitudes of the Moon and the Sun", written by his student or by him, was included in the mandatory list of works that had to be studied by novice astronomers in ancient Greece. His works were widely quoted by Archimedes, who was considered by all to be the brilliant scientist of Hellas (in the surviving works of Archimedes, the name of Aristarchus occurs more often than the name of any other scientist).
An asteroid (3999, Aristarchus), a lunar crater, and an air hub on his homeland, the island of Samos, were named in honor of Aristarchus.
