Johannes Kepler - Blog Posts
“If you read the history of the development of chemistry and particularly of physics, you will see that even such exact natural sciences could not, and still cannot, avoid basing their thought systems on certain hypotheses. In classical physics, up to the end of the 18th century, one of the working hypotheses, arrived at either unconsciously or half-consciously, was that space had three dimensions, an idea which was never questioned. The fact was always accepted, and perspective drawings of physical events, diagrams, or experiments, were always in accordance with that theory. Only when this theory is abandoned does one wonder how such a thing could ever have been believed. How did one come by such an idea? Why were we so caught that nobody ever doubted or even discussed the matter? It was accepted as a self-evident fact, but what was at the root of it? Johannes Kepler, one of the fathers of modern or classic physics, said that naturally space must have three dimensions because of the Trinity! So our readiness to believe that space has three dimensions is a more recent offspring of the Christian trinitarian idea.”
— Marie-Louise von Franz, Alchemy: An Introduction to the Symbolism and the Psychology
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer, and astrologer.
Kepler is a key figure in the 17th-century scientific revolution. He is best known for his laws of planetary motion, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. These works also provided one of the foundations for Isaac Newton’s theory of universal gravitation.
In astronomy, Kepler’s laws of planetary motion are three scientific laws describing the motion of planets around the Sun.
The orbit of a planet is an ellipse with the Sun at one of the two foci.
A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.
The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit.
Most planetary orbits are nearly circular, and careful observation and calculation are required in order to establish that they are not perfectly circular. Calculations of the orbit of Mars, whose published values are somewhat suspect, indicated an elliptical orbit. From this, Johannes Kepler inferred that other bodies in the Solar System, including those farther away from the Sun, also have elliptical orbits.
Kepler’s work (published between 1609 and 1619) improved the heliocentric theory of Nicolaus Copernicus, explaining how the planets’ speeds varied, and using elliptical orbits rather than circular orbits with epicycles.
Isaac Newton showed in 1687 that relationships like Kepler’s would apply in the Solar System to a good approximation, as a consequence of his own laws of motion and law of universal gravitation.
Johannes Kepler
Kepler’s laws of planetary motion
"I used to measure the heavens; now I shall measure the shadows of the earth. Although my soul was from heaven, the shadow of my body lies here."
-Johannes Kepler-