A History of Physics as an Exercise in Philosophy E J Post Copyright © 1997 by E J Post 2 PREFACE Religions are known to become rigid and despotic when the icons of religion are beginning to replace the teachings in order of importance. In a similar manner some formulas and equations of physics have been assuming an icon-like position for the physical sciences. It raises questions whether there are mathematical icons that are now unduly dominating the scene in physics with the possibility of holding back the exploratory spirit. Since the latter has always been physics' badge of honor, this essay calls on the help of history and philosophy to pinpoint possible onsets of early rigidity wherever they may have occurred. Unfortunately, many physicists have been imbued with ideas that it is exactly philosophy that is in need of such help. The origin of such suspicion goes back millennia. Early philosophers had regrettably misguided their contemporaries about the value of physical experimentation. Ever since the discipline has paid for this attitude of early arrogance For a long time physics has been able to steer clear of a similar arro- gance in their discipline until the beginning of this century. When quantum physics came along, the pitfalls of 'exclusivism' became too numerous and the shield of self defense assumed an unintended edge of arrogance. Physicists began congregating in the legendary land of Hans Anderson under the inspiring guidance Nils Bohr. Rarely had scientists encountered so many new things in so short a time. Faced with the daunting task of sorting out an inebriating avalanche of new perspectives, they started giving known words new meanings in physics. Examples are: nonclassical probability, absolute a priori uncer- tainty, particle-wave duality etc.. Einstein supposedly was quoted as having referred to their activity as an epistemological orgy. If he really said this, his sense of physical reality was superb as usual, even if the word "epistemology" had been mildly misused. The early phases of epistemology, to which Einstein presumably referred, are now known as "ontologies." Mario Bunge calls it "the furni- ture of the world." We know there is good and bad furniture and last, but not least, furniture should harmonize with its intended environment. It is an irony of life that, as philosophy in the early days, now physics stumbled into its own trap of arrogance. If physics made some questionable ontological choices, this booklet may refer to them as rare brands of very durable Copenhagen furniture, yet beautiful in their own right. The problem has been more one of fitting rooms, tables and chairs together and less one of discarding furniture items, because in a short time the house of physics had been changing in a very dramatic fashion. To the extent possible, these pages attempt a 'nontechnical account' of modern physics' facts and sins. In practice this means, there are very few 3 formulas in this book to prevent icons from dominating the scene. If that is a shortcoming, let a more extensive discussion of formalisms make up for it. The result is a subject presentation which, in an optimistic sense, might be said to be reaching from preschool to beyond university. Since Kant's Critique of Pure Reason had philosophy confessing to its sins, followed by a penance long ago, physics is now invited to do the same by confessing to its arrogance. The court of public opinion has sufficient grounds to consider charging the physics profession with: (1) abandoning a royal road to quantization. (2) inadequate consideration of alternatives to Copenhagen views. (3) intimidating rather than convincing others of what are believed to be right choices. Since mathematics is a discipline without which much of physics could not be, the last chapter discusses some parallel developments between the two. A moderate measure of mathematical rigor and down-to- earth philosophy go a long way in helping physics home in on common corrective measures that can disentangle situations where physics may have gone overboard amidst an abundance of too much new in too little time. Pondering the very valuable help rendered by Christine Brunak and Ruth Jackson in the process of proofing the text, it still puzzles and despairs me as to why this subject matter has either something akin to pulling teeth or tends to bring people to the brink of nervous breakdown. E J Post Westchester CA, Sept. '97 4 TABLE OF CONTENTS PREAMBLE ABOUT PHILOSOPHY............................................................................1 Outline of Philosophy Branches ..........................................................................4 THE EMPIRIC SOURCES OF INFORMATION...........................................................10 Archimedes' Principle ..........................................................................................10 The Ptolemaic-Copernican Evolution..................................................................11 Snell's Law of Optical Refraction ........................................................................11 Olaf Roemer's Finite Speed of Light....................................................................12 Empiric Ingredients of the Laws of Dynamics.....................................................13 The Cavendish Experiment..................................................................................14 The Work-Heat Equivalent ..................................................................................14 The Discovery of "Brownian" Motion.................................................................15 The Observation of Crystal Symmetries ..............................................................15 Dalton, the Gas Laws and the New Chemistry ....................................................16 New Perspectives in Optics .................................................................................18 Fundamental Empirics of Electromagnetism.......................................................18 Empirics of the Laws of Heat Radiation..............................................................20 A Survey of Twentieth Century Empiricism .......................................................21 PHENOMENOLOGY .....................................................................................................26 Rigid Body Dynamics ..........................................................................................28 Fluid Mechanics...................................................................................................29 Elastic Media .......................................................................................................30 Lagrangean and Hamiltonian Methods ................................................................31 The Science of Thermodynamics.........................................................................33 The Emergence of Spacetime Descriptions .........................................................34 The Phenomenology of Electricity and Magnetism.............................................35 The Theorems of Local-Global Field Relations...................................................38 Formalism Choices for Global Assessment.........................................................41 Standard Formalisms for Local Exploration........................................................46 Classification of Crystals, the Point Groups ........................................................49 Crystal Physics.....................................................................................................50 Cause and Effect Relations ..................................................................................53 ONTOLOGIES ................................................................................................................54 From Democritus' Atoms to Dalton's and Avogadro's New Chemistry.............................................................................................................55 An Avalanche of Quantum Propositions .............................................................56 Ensemble Implications of Schroedinger's Recipe................................................60 Quantum Electro-Dynamics QED........................................................................62 Brownian Motion.................................................................................................64 Crystal Classification, The Space Groups............................................................64 Remaining Ontologies .........................................................................................65 EPISTEMOLOGY...........................................................................................................67 Some Epistemic High Points ...............................................................................68 5 The Epistemic Puzzle of Particle and Wave........................................................70 Assessing Phenomenological Pathways...............................................................71 Copenhagen..........................................................................................................75 Helium Spectrum and Heisenberg Exchange Force.............................................83 MATHEMATICS ............................................................................................................87 Introduction..........................................................................................................87 The Mathematical Field Concepts