Kepler's laws of planetary motion formula_16 The area enclosed by the elliptical orbit is formula_17 So the period formula_18 satisfies and the mean motion of the planet around the Sun satisfies This captures the relationship between the distance of planets from the Sun, and their orbital periods. Kepler enunciated in 1619 this third law in a laborious attempt to determine what he viewed as the "music of the spheres" according to precise laws, and express it in terms of musical notation. So it was known as the "harmonic law". Using Newton's Law of gravitation (published 1687), this relation can be found in the case of
Three Laws of Robotics settlers on new Spacer worlds may lead to the robots seeing themselves as the true humans, and deciding to keep the worlds for themselves rather than allow the Spacers to settle there. "—That Thou Art Mindful of Him", which Asimov intended to be the "ultimate" probe into the Laws' subtleties, finally uses the Three Laws to conjure up the very "Frankenstein" scenario they were invented to prevent. It takes as its concept the growing development of robots that mimic non-human living things and given programs that mimic simple animal behaviours which do not require the Three Laws. The presence of