Galileo was born in Pisa in 1564 (the year Michelangelo died) and died in Arcetri in 1642 (the year Newton was born). Dedse 1597 he was a convinced Copernican. In 1604 he studied a nova star that had appeared in the constellation Ophiucus. In 1610 he published the “Sidereus nuntius” where he described all the discoveries made with a telescope of about 20 magnifications built by him. The data obtained served him to confirm the Copernican system. Nobody like him knew how to outline the philosophical problems of the new science. His conflicts with the dominant ideology: the Church and Aristotelianism, culminated in 1932, the year of the publication of “The Two Maximum Systems of the World” and in the process to which he was subjected by the Inquisition for his Copernican ideas . He can be considered as one of the creators of the new science

Galileo’s telescope

Galileo himself describes in “Sidereus Nuntius” (1610) how he built his first telescope: “Based on the doctrine of refraction, I first prepared a lead tube, at the ends of which I placed two lenses, both flat in one of their faces, while, in the other, one of the lenses was convex and the other concave. ‘ With this primitive telescope, Galileo became the main propagandist of the Copernican system, since, on the one hand, he demolishes some theses of Aristotelianism, such as the perfection and immutability of the heavens and, on the other, his empirical discoveries they have an explanation in a Copernican Universe.

Drawings of the surface of the Moon

Thanks to his telescope, Galileo discovered that “the Moon is not covered by a smooth and polished surface, but, like the face of the Earth, is full of large protrusions, deep gaps and fruitlessness” . This discovery falsified the traditional belief that the heavenly bodies were perfectly spherical. The drawing of the Moon is in Galileo’s “Sidereus Nuntius”

.The Medicean stars

One of the most spectacular discoveries that Galileo made with his telescope was that of the satellites of Jupiter, which he named “Medicean stars” (Medicea sidera) in honor of the Florentine Medici. This discovery was of great importance to give credence to the Copernican system. Galileo himself said: “There are four stars in the sky that move around Jupiter like Venus and Mercury do around the Sun.” Sunspots With the discovery of sunspots, Galileo deals another blow to the traditional immutability of the sky. On the other hand, this discovery shows us the scientific ambiguity of the seventeenth century. With its greatness and its miseries, because it seems that Kepler was the first to discover sunspots by accident. However, it was the Chinese who, free from Aristotelian prejudices, had already discovered them centuries age Contemporary with Galileo, the Jesuit P. Critoph Scheiner observed in 1611 the spots of the Sun with Galileo’s telescope

The phases of VENUS

The phases of Venus, predicted by Copernicus and discovered by Galileo thanks to
his telescope, they supposed a refutation of the Ptolemaic system while they were
explained by the Copernican system.
In the Ptolemaic system an observer from Earth could not see more than the
first crescent of the illuminated face of Venus. In the Copernican system you can
see almost the entire illuminated face of Venus at the moment when it is about to
pass behind the Sun or at the moment when it just did. Since in this
moment is when it is farthest from the Earth, that is why it looks the most

Isaac Newton

He was born in Woolsthorpe (Lincolnshire) in 1642 and died in London in 1727. He was a student and professor at Trinity College, Cambridge. The first 35 years of his life were the most creative, because he formulated the binomial theorem, discovered the calculus of fluxions (infinitesimal analysis), built the first reflecting telescope, discovered the nature of white light, and understood the universal character of light. gravitational attraction. For many historians of science he is the greatest scientist of all time. An unpleasant, ambitious, moody man, he was of the Royal Society and director of the Mint. He created the new physics and closed the Copernican revolution with his law of universal gravitation, giving it a physical basis. His most important works are: “Philosophiae Naturalis Principia Mathematica” (1687) and “Optics” (1704).

Newton’s reflecting telescope

Newton built the first reflecting telescope in 1671. 5 cm. diameter and
15 cm. long, could magnify objects in the same way as a telescope
ordinary of the time 180 cm.
Newton’s reflecting telescope is a sample of the advances of the theory (Optics of
Newton) and science’s need for a technologically advanced instrument.

Satellites as projectiles

Newton explained the movement of planets and satellites as if they were huge projectiles launched at such a great speed that they never fell on the surface of the Earth and thus always revolved around it. In “De Systemate Mundi” (1666) Newton explained the figure thus: “If we examine the motion of the projectiles we will understand. It is easy for the planets to stay in their orbits thanks to centripetal forces (…). If we now imagine bodies thrown in parallel directions towards an increasingly higher horizon, 5, 10, 100, 1000 or more miles or as several semi-diameters from the Earth then those bodies, according to their different speeds and different forces of gravity according to their altitudes, they describe curves concentric to the Earth or differently eccentric and they will continue rotating in the sky with these same trajectories as the planets do in their orbits ».