Definition

In addition to this, you need to know more about it.

Astronomy is the science of observing stars , seeking to explain their origin , their evolution , as well as their physical and chemical properties . With more than 5,000 years of history, the origins of astronomy go back beyond Antiquity in prehistoric religious practices . Astronomy is one of the few sciences where amateurs still play an active role. It is practiced as a hobby by a large audience of amateur astronomers . Astronomy is considered to be the oldest of the sciences. Archeology indeed reveals that certain extinct civilizations of the Bronze Age , and perhaps of the Neolithic , already had knowledge of astronomy. They had understood the periodic character of the equinoxes and undoubtedly their relation with the cycle of the seasons, they also knew how to recognize certain constellations . Modern astronomy owes its development to that of mathematics since ancient Greece and to the invention of observation instruments at the end of the Middle Ages . If astronomy is practiced for several centuries alongside astrology , the Age of Enlightenment and the rediscovery of Greek thought saw the emergence of the distinction between reason and faith , so that astrology is no longer practiced by astronomers .

In addition to this, you need to know more about it.

Invention

In addition to this, you need to know more about it.

The invention of astronomy dates back to the Chaldean civilization. In its early days, astronomy was simply the observation and prediction of the movement of celestial objects visible to the naked eye.

These different civilizations bequeathed many contributions and discoveries .

In addition to this, you need to know more about it.

Advances in knowledge

In addition to this, you need to know more about it.

During the Renaissance , Copernicus proposed a heliocentric model of the Solar System having many points in common with the thesis of Nasir ad-Din at-Tusi , with the De revolutionibus published in 1543 after his death.

Almost a century later, this idea is defended, extended and corrected by Galileo and Kepler . Galileo imagines an astronomical telescope , drawing inspiration from the work of the Dutch Hans Lippershey (whose telescope only magnified three times and distorted objects), to improve his observations. Relying on very precise observations of observations made by the great astronomer Tycho Brahe , Kepler is the first to imagine a system of laws governing the details of the movement of the planets around the Sun, but is not able to formulate a theory going beyond the simple description presented in its laws .

It is Isaac Newton who, by describing gravitation by his laws of motion, finally allows a theoretical explanation to be given to the motion of the planets. He also invented the reflector telescope , which improved observations.

The shift from the geocentric model of Ptolemy to the heliocentric model with Copernicus / Galileo / Newton is described by the philosopher of science Thomas Samuel Kuhn as a scientific revolution .

The stars are discovered to be very distant objects: the closest star in the Solar System , Proxima Centauri , is more than four light years away .

In addition to this, you need to know more about it.

Evolution

In addition to this, you need to know more about it.

With the introduction of spectroscopy , it is shown that they are similar to the sun , but in a wide range of temperature , mass and size. The existence of our Galaxy , as a distinct set of stars, is not proven until the beginning of the 20th century due to the existence of other galaxies .

Shortly after, we discover the expansion of the universe , a consequence of Hubble 's law , establishing a relationship between the speed at which other galaxies move away from the Solar System and their distance.

Cosmology made great progress during the 20th century , in particular with the Big Bang theory, widely supported by astronomy and physics, such as cosmological thermal radiation (or fossil radiation), and the various theories of nucleosynthesis explaining abundance chemical elements and their isotopes .

In the last decades of the twentieth century , the appearance of radio telescopes , radio astronomy , and computer processing means, allowed new types of experiments on distant celestial bodies , by spectroscopic analysis of the emission lines emitted by atoms. and their different isotopes during quantum jumps , and transmitted through space by electromagnetic waves .

In addition to this, you need to know more about it.