Cosmology: The Origin and Evolution of the Universe

Defn: Astronomical Unit: Average orbital radius of Earth Kepler’s Three Laws of Planetary Motion. Elliptical Orbits. Radius vector of planet sweeps out equal periods in equal times. P2 = a3. Geometrical Properties of Elliptical Orbits. r + r’ = 2a = constant (1-1) by defn of ellipse. b2 = a2 - a2e2 = a2(1-e2) (1-2) from Pythagorean theorem ................
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