Johannes-Kepler

“We find, therefore, under this orderly arrangement, a wonderful symmetry in the universe, and a definite relation of harmony in the motion and magnitude of the orbs, of a kind that is not possible to obtain in any other way.”
-Johannes Kepler, 1619.

Image credit: Kevin Shearer (instagram: k.d.s.photography)

Johannes Kepler - Geometrical Harmonies in the Perfect Solids, “Harmonices Mundi”, 1619.

Kepler was convinced “that the geometrical things have provided the Creator with the model for decorating the whole world”. In Harmony, he attempted to explain the proportions of the natural world - particularly the astronomical and astrological aspects - in terms of music. The central set of “harmonies” was the Musica Universalis or “Music of the Spheres”.

Kepler began by exploring regular polygons and regular solids, including the figures that would come to be known as Kepler’s solids.
Harmony resulted from the tones made by the souls of heavenly bodies - and in the case of astrology, the interaction between those tones and human souls. In the final portion of the work, Kepler dealt with planetary motions, especially relationships between orbital velocity and orbital distance from the Sun. Similar relationships had been used by other astronomers, but Kepler treated them much more precisely and attached new physical significance to them.

Isaac Newton assumed an inverse square law for gravitation and considered two incompressible perfect spheres with nothing else in the universe. This allowed him to compute the orbits of the planets to tolerable precision. Deviations from these predictions taught us new things: unexpected changes in the orbit of Uranus led to the discovery of Neptune, the anomalous precession of the perihelion of Mercury’s orbit became one of the major proofs of general relativity. We now have far more sophisticated models of gravity than Newton’s, and are working on refining them further.

But you can also tell this story another way. Newtonian orbits gave rise to the idea of a clockwork universe, which turned out to be deeply misleading. In the actual solar system, tidal forces and the influence of other planets on orbits mean that orbits are constantly changing. The solar system does appear to be reasonably stable, but for an entirely different reason than the one suggested by the simplified two-body problem. The adoption of important ideas was delayed due to over-rigid Newtonian thinking.

Obviously Newtonian gravity was a tremendous intellectual advance, and probably a necessary step to further progress in physics. So it is good that some people think this way. But it is also good that some people thought other ways and were willing to come out of left field with inconsistent ideas rather than working on refining existing models. Intellectual history is filled with advances that came about because someone insisted stubbornly that inconvenient observations were correct, and other advances that came about because someone had the courage and insight to ignore observations.

—  Aaron Brown

The image of Galileo Galilei has been inflated like a dirigible airship that floats above the early modern period obscuring the efforts and achievements of all the other scientists, his shadow only being broken by the light of that other g-d of science Isaac Newton. Unfortunately this image is total bullsh__ and its propagation leads to a major distortion in our understanding of the historical development of science. […]

Central to this image of Galileo is his supposed uniqueness; through his ‘once in human existence genius’ he single-handedly created modern science, the scientific method, observational astronomy and physics. This view is … only possible if one totally ignores his contemporaries. Of these Johannes Kepler, Thomas Harriot, Christoph Scheiner, William Gilbert, Christoph Clavius, Francoise Vieta, Isaac Beeckman and Simon Stevin are all scientists who are on a level with Galileo both from their abilities and also from their scientific achievements and contributions.

…David Fabricius, Harriot, Simon Marius, Christoph Scheiner and another boat load of so called minor figures [do not get the credit they deserve.] […]

Galileo … is supposed to have been the first to note that bodies of unequal weight fall at the same speed in a vacuum when in fact this was first noted by Simon Stevin. […]

In truth Galileo was canonised by the Catholic Church! The inflation of his image was a result of Galileo being declared the main scientific martyr in the greatest myth of the history of science, the totally fictitious ‘War Against Science’. Galileo’s inflated image is largely a product of the 19th century and the perception that he had been sacrificed on the altar of religion.

—  Thony Christie