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 III 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? Information about his life, as well as about most other astronomers of antiquity, is very small. It is known that he was born on the island of Samos. His years of life are not exactly known. In the literature usually indicate 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 biography of an astronomer. Aristarchus studied under the eminent philosopher, a representative of the peripatetic school of Straton from Lampaska. 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.
The construction of Aristarchus
What discoveries did Aristarchus of Samos make? Archimedes in his essay Psammit reports brief data on the astronomical system of Aristarchus, which was set out in an essay that did not reach us. Like Ptolemy, Aristarchus believed that the movements of the planets, the Moon and the Earth, occur within the sphere of immovable stars, which, according to the notions of 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 construction of Aristarchus is the highest achievement of the heliocentric doctrine. It was their courage in the author that led to the accusation of apostasy, which we discussed above, and he was forced to leave Athens. The only small-scale 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 been preserved.
World order
What are the views of Aristarchus of Samos interesting? When they study the history of the development of the views of mankind on the construction of the Universe and on the place of the Earth in this construction, they always remember the name of this ancient Greek scientist. Like Aristotle, he preferred the spherical structure of the universe. However, unlike Aristotle, he did not put the Earth at the center of 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 design 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 XVI-XVII centuries.
In the heliocentric design, the Earth is represented by spinning around its own axis (the revolution takes place in one star day) and at the same time around the Sun (the revolution takes place in one star year). The result of the first movement is the visible revolution of the celestial sphere, the result of the second is the annual movement of the Sun along the ecliptic among stars. Regarding the stars, the Sun is considered immovable.
Geocentrism is the belief that the center of the universe is the earth. This world construct was the dominant theory throughout Europe, in ancient Greece and other countries for centuries. In the 16th century, the heliocentric construction of the world began to gain fame, as the industry developed 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 famous work "On the distances and sizes of the Moon and the Sun", in which he tries to establish the distance to these celestial bodies and their parameters. Ancient Greek scholars on these topics have repeatedly spoken out. So, Anaxagoras from Clazomen claimed that the Sun was larger than the Peloponnese in terms of 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 by astronomers, but simply invented. But Aristarchus of Samos used a scientific method based on the observation of lunar and solar eclipses and lunar phases.
His formulations are based on the hypothesis that the moon takes light from the sun and looks like a ball. From which it follows that if the moon is placed in quadrature, that is, is cut in half, then the angle of the sun - moon - earth is straight.
Now the angle between the Sun and the Moon is measured α and, having “solved” a right-angled triangle, we can establish the ratio of the distances from the Moon to the Earth. According to the measurements of Aristarchus, α = 87 °. As a result, it turns out that the Sun is almost 19 times farther than the Moon. In antiquity, trigonometric functions did not exist yet. Therefore, to calculate this distance, he used very complicated calculations, described in detail in the essay under consideration.
Further, Aristarchus of Samos drew some data on the eclipses of the Sun. 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 that the Sun is larger than the Moon so many times, how many times further, 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 relationship of the parameters of the Moon and the Sun to the magnitude of the Earth. This time he drew an 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 orbit of the moon, the width of the cone of this is twice as large as 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 smaller than the Earth's radius, which is almost identical to the correct value (0.273 radius Earth).
The scientist downplayed the distance to the Sun by about 20 times. In general, his method was quite imperfect, unstable to errors. But this was the only way available in antiquity. Also, contrary to the name of his work, Aristarchus does not calculate the distance from the Sun to the Moon, although he could have done it easily, knowing their linear and angular parameters.
The work of Aristarchus has great historical significance: it was from him that astronomers began to study the “third coordinate”, during which the scale of the Universe, the Path of the Milky and Solar System were revealed.
Calendar improvement
You already know the years of the life of Aristarchus of Samos. He was a great man. So, Aristarchus influenced the updating of the calendar. Censorin (writer of the 3rd century A.D.) indicated that Aristarchus set the duration of the year to 365 days.
In addition, the great scientist introduced a calendar span of 2434 years. Many historians claim that this period 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 the first astronomer in chronology for whom two different values of the length of the year are 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 the recreation of the Vatican lists according to Rawlins is true, then the distinction between sidereal and tropical years was first determined by Aristarchus, who should be considered the detector of precession.
Other work
It is known that Aristarchus is the creator of trigonometry. According to Vitruvius, he modernized a sundial (he also invented a flat sundial). In addition, Aristarchus studied optics. He thought that the color of objects appears when light falls on them, that is, that colors do not have color in the dark.
Many believe that he set experiments to identify the resolving susceptibility of the human eye.
Meaning and memory
Contemporaries understood that the works of Aristarchus were of outstanding importance. His name was always called among the famous mathematicians of Hellas. The work "On the distances and sizes of the Moon and the Sun", written by his student or him, was included in the obligatory list of works that needed to be studied by novice astronomers in ancient Greece. His work was widely quoted by Archimedes, whom everyone considered the brilliant scientists of Hellas (in the surviving works of Archimedes, the name Aristarchus is more common than the name of any other scientist).
In honor of Aristarchus, an asteroid (3999, Aristarchus), a lunar crater, and also an airport in his homeland, the island of Samos, were named.