History of the Astronomy Students of 4ºA - ESO Madrid - Spain

Astronomy Astronomy, the law of the stars, is the science that treats the study of the celestial bodies, its movements and the phenomena related to them. All the civilizations have had contact with them. It is the oldest science. People have felt fascination for the sky. They have deified the Stars, The Sun and the Moon. They have tried to measure the time and to have a calendar: DAY: Rotation of the Earth. MONTH: Cycle of the Moon. YEAR: Translation of the Earth around the Sun.

Stonehenge (Salisbury, UK, 3000 a.C.) First European Astronomical observatory ?

Egipcian Astronomy 4000 b.c. The year lasted 365 days: 12 months of 30 days, and 5 more days called epagomenos. The year lasted 365 days: 12 months of 30 days, and 5 more days called epagomenos. Calendar with 3 seasons of 4 months each: Flood, winter and summer. Calendar with 3 seasons of 4 months each: Flood, winter and summer. Gyzeh Pyramid aligned with the Pole Star: its shadow marks the beginning of the seasons. Gyzeh Pyramid aligned with the Pole Star: its shadow marks the beginning of the seasons.

The Babylonians b.c. ZIGURATS. Meteorological observatories.. Name of the constellations: the Zodiac.. Movement of the planets.. Average length between two equal Moon’s phases: days

Aristoteles b.C.. Greek philosopher and scientific.. The Earth is not flat; it’s a sphere, that is why the stars seem to change its height in the horizon.. The Earth is the centre of the Universe and the celestial bodies are fixed on a number of spheres moved by a “divine force”.

Aristarco of Samos 320 b.c. He is the first one who upholds the “Heliocentric theory”: the Sun is the centre of The Universe. He anticipated Copernicus in 18 centuries. He measured the distance Earth-Sun using the parallax method. The Moon diameter is 20/57 of the Earth’s. The distance from the Moon to the Earth is 79 times the radius of the Earth (actually it is 60).

Erastotenes Cirene,276 aC-Alejandría, 194 b.C.. Father of the Geodesy.. Diameter of the Earth: distance Alejandría-Siena, (Asuán): 5000 stadiums (x 160mts)= 800Km Circunf: 800x360/7,2=40000 Km  Radius=6362 Km

Claudius Ptolomeo a.d.. Almagesto, 13 tomes: Summary of all astronomic knowledge of the Greek civilization.. Geocentrism: The Earth, motionless (inmobile), is the centre of the Universe. Everything revolves around it. The moon and the planets have circular-epycycle orbits around a central point, that revolves around the Earth. (Theory of the circles above circles). This explains the different brightness of the celestial objects and the retrograde movement of the planets.

Ptolomeo a.d. PTOLOMAICUS’ SYSTEM

Nicolas Copernicus Torun, Poland, Founder of the modern astronomy for his heliocentric theory: - The Sun is the centre of the Universe and, Mercury, Venus, Earth and The Moon, Mars, Jupiter and Saturn, revolve around it. - The stars stay fixed and they don’t orbit around the Sun. - The Earth has movements: daily rotation, annual translation and annual inclination of its axis. - The retrograde movement of the planets is due to the movement of the Earth.. His work De revolitionibus orbium coelestium ( ) was published when he died, in 1543.

Nicolas Copernicus Torun, Poland, COPERNICANUS’ SYSTEM

Johannes KEPLER Germany, Johannes KEPLER Germany, One of the main figures of the scientific and astronomic revolution.. He formulated the three laws of the planetary movements: 3 rd. Law: the relation of the squares of the ellipses. 2 nd. Law: the planets trail on 1 st. Law: the planets move in equal areas in equal times. orbital periods and the cubes of the biggest semiaxis is constant.

Galileus Galilei (Pisa, Italy, ) Galileus Galilei (Pisa, Italy, ). He discovered the sunspots.. He pointed at the sky with the first telescope (refractor).. He was the first one in watching the Saturn rings.. He discovered the Jupiter satellites.. He discovered that Venus has got phases.. He watched the mountains on the Moon. He was the first in using the scientific method.

ISAAC NEWTON England, Physicist, philosopher, mathematician, inventor.  Gravitational Law:  3 laws of the dynamics: icF=ma  Optics: nature and spectrum of the light.  Newtonian telescope (reflector).  Integral and differential calculus.

XVIII and XIX centuries The great boom of the Astronomy  The Discovery of Uranus (1789) and Neptune (1846).  Cosmology is born (study of the structure of the Universe).  Photography appears (1822) and the spectral analysis (Fraunhofer): Astrophysics is born.  Discovery of the Martian canals (false) by Schiaparelli in Wilhelm Herschel’ telescope

XVIII and XI8X centuries Wilhelm HERSCHEL’ telescope in Madrid In 1800 Herschel built a large teles- cope, a bit smaller than the one he had in England, which is installed in the Royal Observatory of Madrid. Nowadays only the original lens (made of metal) is preserved.

Heber Doust Curtis Virginia, USA, He was famous for his studies about the nebular spinals, that are regions of the interstellar space formed by gases. He had a great debate with Shapley about the dimensions of our galaxy. There are some other galaxies outside ours. Trifida nebular (M20)

Edwin Powell Hubble Missouri, USA, He classified the galaxies. He showed the expansion of the Universe measuring the displacement towards the red between distant galaxies. The Milky Way is not the centre of the Universe. What had to happen for the galaxies began to move away?  BIG BANG