1. VII Kosmisch ¥

2. Anaxagoras (499 - 428) To every great there exists a greater. Empedokle (483 - 425) The universe is three times as large as the system earth-moon. Demokrit (460 - 375) Milky way consists of many stars. The universe has no center Aristotele (384 - 322) The earth is tiny compared to the universe. The earth is in the center of the universe. The earth is a sphere. When sailing to south always new stars appear.

3. Aristarch of Samos (310 - 230) First proponent of the heliocentric system Determined the ratio of distances to moon and sun. Angle measured: 87°  cos 87° = 1 : 19 Improved by Kepler: 89°51'  1 : 380

4. Eratosthenes (276 - 194) Born in Cyrene (today Schahhat, Libyen) 240: third chairman of the Museion Educator of the crown prince Very universal scholar. Invented the leap day. Produced the first astronomical maps with over 600 stars. Sieve of Eratosthenes

5. Determined the circumference of earth Alexandria (31°) Well diggers in Syene (= Assuan, 24°) Result: 41000 km improved in 1670: 39800 km correct: 40009 km (over the poles)

6. Claudius Ptolemaios (85 - 165) Worked in Alexandria Fair skin, small feet, red birtmark At chin, black beard ??? Geocentric system

7. Nicole d‘Oresme (1320 -1382) Heliocentric system Jean Buridan (1295 - 1358) Prof. at Univ. Paris Thought like Oresme Buridan‘s donkey, two heaps of hay.

8. Nicolaus Copernikus (1473 - 1543) 1510: The foundations of his heliocentric system. 1543: De revolutionibus orbium coelestium

9. Thomas Digges (1546 - 1595) 1576: Infinite World But there can be no movement of infinity and of an infinite body, and therefore no diurnal revolution of that vastest Primum mobile.

10. William Gilbert (1544 - 1603) De mundo nostro sublunari (1651)

11. Heinrich Olbers (1758 - 1840) Astronomer and physician at Bremen Olbers‘ paradox: Why is heaven dark at night? Solid angle of a star ~ A/r 2 Number of stars in spherical shell ~ r 2  r Solid angle covered by stars of a shell ~ A  r r

12. Expansion of the universe started 13,7  10 9 years ago age = 4,3  10 17 s Vesto Slipher (1875 - 1969) 36 of 41 galaxies move off of us. Edwin Hubble (1889 - 1953) 1929: Expansion of the universe: Hubble-constant Finite universe with Doppler-redshift

13. George Gamow (1904 - 1968) 1949: predicted cosmic background radiation left over from the big bang Arno Penzias (  1933) Robert Woodrow Wilson (  1936) 1965: Discovery of cosmic background radiation

14. 2,7 K Maximum has = 1,1 mm 375 photons / cm 3

15. Radius of the universum = 46.5  10 9 lightyears Volume of the universum = 10 80 m 3 10 80 atoms 10 88 photons 10 80 m 3 / (10 -95 m) 3  less than 10 365 elementary cells