The structure of scientific inference

Abstract

Natural philosophy was a term that applied to the study of all things in Nature: deductions based on philosophical arguments on how Nature worked. Envision someone in Aristotle's time picking up a heavy rock and a pebble on a beach. It takes more effort to lift the heavier rock than the pebble. Would not a similar difference work in reverse, when the two were dropped from the same height? Should not the heavier rock fall to the Earth faster than the pebble? There was no need to test a conclusion that was obtained from pure logic, and the ancient Greeks did no experiments to prove their logically drawn conclusions. Things in the heavens were perfect and pure because that is where the gods resided; things on Earth were considered to be imperfect because that is where the humans lived.Classical physics began during the Renaissance Period when Galileo pointed the telescope to the heavens to reveal imperfections in structure and Newton showed through mathematics that the Laws of Nature applied to both the heavens and the Earth. Equations made predictions on the motions of celestial objects that proved true. In his essay "A Philosophical Essay on Probabilities" Pierre Simon Laplace went so far as to propose a demon that, if given the coordinates and momenta of everything in the Universe, could predict the future as well as reproduce the past. The philosophical view of cause-and-effect was used as an argument to support the religious view of predestination, such as in Calvinism. Michael Faraday and James Clerk Maxwell extended classical physics to include electromagnetism. The beginning of the "new physics" was in 1900 when Max Planck explained the density profile of black body radiation by assuming the vibration energy of the atoms in a solid was quantized.In 1905, Einstein introduced wave–particle duality for light and special relativity with the mass–energy equivalency, E = mc2. All matter is condensed energy with both wave and particle properties. The Universe is composed of probability waves, manifested in the Schrödinger equation. Local cause-and-effect became a probability outcome. The quantum world of modern science reinstated free will. Einstein's Theory of General Relativity changed our views about space and time. The curved trajectories of objects interacting with each other as they moved through flat Euclidean space were now described as objects moving is a straight line through curved space with the degree of curvature determined by the masses of the other objects.The paradigm shifts from natural philosophy, to classical physics, to the "new" physics did not travel on a smooth road paved with gold and platinum with cheering crowds on both sides of the road. The journey was like running the gauntlet in ancient days, with jeering crowds of religious and political antagonists with sharp-edged objects to suppress the advancement. What was at stake was the influence of religion and politics on natural philosophy to the influence of the "new" science on religious views and political decisions.How and why did the philosophical views of the Universe change from those of the Greek philosophers to those of the new science? To better understand that, the road was not smooth in the task to grasp the secrets of the Universe, the experiences of a select group of contributors are described in limited detail, along with the significance of these events. What were the individual encounters of barriers set up by political struggles, religious dogma and ideology, and superstitious beliefs? This discourse ends with commentaries on the interpretation of equations and present day philosophy of science.