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Explore the evolution of astronomy leading up to Johannes Kepler, his revolutionary contributions, and lasting legacy. Dive into ancient Greek astronomy, Ptolemaic system, Copernican revolution, and Kepler’s Three Laws of Planetary Motion.
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FINAL FILE Slide 1 Slides for use on “The Space Show” The show on November 22 is about the brilliant 17th century astronomer and mathematician Johannes Kepler. But Kepler needs to be understood in the context of what came before him. So the first few slides are concerned with giving a brief history of astronomy up to his time, starting with the ancient Greeks.
Slide 2: The Celestial Sphere, to which all the stars were meant to be attached.
Slide 4: The motion of Mars (relative to the background of stars) during 2009 & 2010
Slide 5: The suggestion of Apollonius for explaining planetary motion
Slide 6: Ptolemy’s adjustments to try to line up theory with observation The Ptolemaic System
Slide 7: An illustration from the “Nuremberg Chronicle”, published in 1493 (Reproduced by kind permission of the Syndics of Cambridge University Library (Inc 0.A.7.2[888])
Nicolaus Copernicus: 1473 -1543 Slide 8: Explanation of retrograde motion of the planets
Slide 9: Tycho Brahe’s compromise system. It maintained a stationary Earth, but gave many of the advantages of simplicity and internal logic of the Copernican system I am grateful to Wikipedia for this much clearer version of Tycho’s original diagram.
Slide 10: Part of the Holy Roman Empire in 1600 (now southern Germany, Austria & the Czech Republic)
Johannes Kepler, 1571 - 1630 Slide 11: Three different portraits of Kepler. Probably the middle one is the most accurate.
Slide 12: The house in Weil der Stadt where Kepler was born, now a Kepler museum, and the statue of Kepler in the the main square, a short distance from the house.
Slide 14: If two concentric circles are drawn, in which one has twice the radius of the other, then an equilateral triangle will fit exactly between them: so this triangle would fit neatly between the orbits of Jupiter and Saturn.
Slide 16: Kepler’s completely erroneous model of the Solar System, in which the orbits of the planets (represented by spheres) are separated by shapes such as the cube and the tetrahedron.
Slide 17: The first two of Kepler’s Three Laws of Planetary Motion 1. The planets travel round the Sun in ellipses (not circles), with the Sun at one focus of the ellipse. (1609) 2. They sweep out equal areas in equal times. (1609)
Slide 18: explanation of how glasses correct short & long sight Concave
Slide 19: An observational difference between the Ptolemaic (Earth-centered) & Copernican (Sun-centered) world views
Slide 23: Kepler’s legacy 1. One of the first Copernicans. Three laws of planetary motion – and the first to suggest that the planets were controlled by a force emanating from the Sun. In optics: (a) explanation of why lenses correct short & long sight; (b) realisation that the image on the retina is upside down; (c) discovery of inverse square law for light intensity. 3. First explanation of why the Moon appears red during a total lunar eclipse 4. Wrote the first relatively modern science fiction story 5. One of the first to suggest that tides were caused by the Moon 6. Responsible for the design of the modern refracting telescope 7. Guesses that later turned out by chance to be right: (a) there might be a planet between Mars & Jupiter (b) Mars might have two moons (c) Jupiter might have a Great Red Spot
You are here Slide 24
Slide 25 50 billion years in a supersonic plane
Slide 26: The Hubble Ultra Deep Field Credit: NASA, ESA, H Teplitz & M Rafelski, A Koekemoer, R Windhorst, Z Levay.
Slide 27 500 years ago Now