Physics & Reasoning
(An Ongoing Tract)
Subroto Roy DRAFT 14.10.2017
0. Since Philosophy of Economics (Routledge 1989) I have tentatively applied similar methods of reasoning to diplomacy, politics, psychology, religion, literature; now an exploration into physics.
Chapter 1 “This is where we got to”
Chapter 2 Telescopes & Oxygen
Chapter 3 Facts, Hypotheses, and Guesses
Chapter 1 “This is where we got to”
1.1. The purpose of physics has been, and remains, twofold: improve the self knowledge of our species, & enhance and affirm life by technology. In the last 200 years physics and other sciences have been massively successful at doing both.
1.2. Quantum Mechanics or other seemingly complex baffling aspects of physics today are ultimately theories of reasonable human belief & action; what it is we *ought to* or *may* believe given the current state of evidence; the significance of physical theories has to do with their applications to technology, what they do for us…
1.3. Other species of flora & fauna each have their own comprehension of Nature for purposes of survival, growth & reproduction; none yet is as articulate or systematic as homo sapiens. We teach our Science at our schools and universities too. Some other hominid or other future intelligence may find us extinct in their archaeology and wish to comprehend our Science for their purposes.
1.4. Science is a human creation, for our purposes. And the purpose ultimately is not one of using mathematics to paint landscapes of an imaginary eternal platonist Heaven “somewhere”, “out there”. The purpose of physics is practical: enhance and affirm life. Both Einstein and his Quantum Mechanics critics may have tried to be platonist landscape painters, an impossibility.
1.5. Our state of knowledge at a given time is the answer to the question: What is it most reasonable to believe on the basis of current evidence about light mass energy time motion space particles fields..? An efficient attitude to physics may be one of creating, as it were, a time capsule every day for a future intelligence which finds us extinct the next day, ie tomorrow. We say to them: “This is where we got to”.
1.6. Notice that to tell a future intelligence “This is where we got to” isn’t to say “We wrote equations depicting physical reality really *really* seems to look like this to us” (the platonist’s mistake). The purpose of any science is to improve the self-knowledge of homo sapiens (the creators of all known science) and enhance and affirm life on earth through technology. The purpose isn’t to try to paint mathematical landscapes in an invisible eternal platonist Heaven.
1.7. When we can reasonably imagine a world before human beings existed it’s reasonable to imagine a world where we are extinct too. We have received this world with the knowledge and wisdom of our ancestors about it, in books photos art etc; we may be required to do the same for the future.
1.8. When we are extinct we may or may not be discovered in the archaeology of a future intelligence who may be other hominids or something else. My proposal is physics be done with a daily attitude of informing such a future intelligence “This is where we got to”…
1.9. “This is where we got to” is a dynamic state…changing every day with our changing knowledge of light mass energy space time particles fields etc.
1.10. “This is where we got to” includes our certain knowledge from Aristarchus, Copernicus and others that our little solar system is heliocentric…
1.11. “This is where we got to” includes our experience of geometry, of Earth’s curvature when we “can see ships vanish behind the horizon’s edge” tho’ we “cannot put our heads out of the universe to see its curvature” (Freudenthal).
1.12. We are as confident about the solar system being heliocentric and the surface of the Earth being curved as GE Moore was when he declared he knew he had one hand and another, saying he was certain the Earth had existed for long before he was born and would continue afterwards, that he had always been on or never far from the surface of the Earth, etc.
1.13. “This is where we got to” includes our multitudes of current or inherited puzzles, dead ends, controversies…it’s a complex living open discussion…
1.14. That “This is where we got to” is a correct normative goal for physics may even be capable of proof.
1.15. If we can reasonably imagine a world spinning on its axis before homo sapiens evolved, we can do the same of when homo sapiens is extinct…Ask: What is the status of arithmetic geometry or chemistry, let aside music or literature, in those worlds without humans?
1.16. Do truths of arithmetic geometry or chemistry, eg carbon’s atomic weight is 12, remain whether or not there are or will be or have been humans…?
1.17. A human creation like Da Vinci’s Cartoon still has meaning after Da Vinci or other humans are gone, but had none before he created it…
1.18. Even the atomic weight of carbon being 12 is not a permanent truth independent of whether there are humans… it’s just a human discovery of a fact…
1.19. Suppose homo sapiens had become extinct before Copernicus, while still believing in the Ptolomaic geocentric solar system….a new intelligence discovering us in its archaeology may have said, Oh look homo sapiens believed in Ptolemy…they didn’t know any better….
1.20. Similarly a future intelligence discovering us as we are today in its archaeology may yet say, Oh look homo sapiens believed carbon’s atomic weight to be 12…Oh look they believed in Planck’s constant, Einstein’s equations, Heisenberg’s electron…
1.21. Carbon’s atomic weight being 12, Planck’s constant, Einstein’s equations, Heisenberg’s electron share something with Ptolomaic astronomy. Namely, these represent the state of human knowledge at a given time, the present, just as Ptolemy’s geocentric solar system did once until it was superceded…
1.22. The best we can leave behind are human creations and discoveries… it is the state of our own human knowledge, not eternal truths independent of our having ever existed… not paintings of landscapes in an eternal Heaven. A new intelligence discovering us might say looking at Da Vinci’s Cartoon, Isn’t that nice?, or at Einstein.. Those were clever insights…
1.23. A new intelligence discovering us may not have accomplished as much as homo sapiens did, just that they are living and we were not…better a live dog than a dead lion, DH Lawrence quoted somewhere…
1.24. Bambrough publicly asked Russell in 1948 if it made a difference if humans as a species perished before their time. If we are destined to be extinct in x years does it matter if we perish by y<x ? Russell dodged the question. I’ve said yes it does matter because we don’t produce the Da Vinci, Einstein work we may have done between y and x. My answer is yes it does matter if humankind perishes at y < x as the good (or net good) we would have produced between y and x never gets created. A future intelligence would find less about us in their archaeology if we perished before our time.
Chapter 2 Telescopes & Oxygen
2.1. Homo sapiens has been very resourceful & ingenious to create as much Science as we have done despite our completely trivial physical size and significance in the solar system.
2.2. Human lifespans have grown with intelligence & civilization to three or four score years, yet summing all human life from ancient times to the present amounts to near zero duration & mass in the life of the Earth or solar system.
2.3. Despite our momentary lives on Earth and complete lack of physical consequence beyond Earth, humankind has managed to comprehend much in recent times about the vast solar system and beyond.
2.4. Eg the Sun is 8 light minutes distant from us with a central temperature of some 20 million degrees, a giant star billions of light years distant may have a temperature of a thousand million degrees. Uranus is 160, Neptune 250, Pluto 327 light minutes distant from us. Alpha Centauri the nearest star to our Sun is 4.35 light years distant, a mere 25.7 thousand billion miles…Etc.
2.5. The magnitudes are unimaginable (or mindboggling) compared to our infinitesimal human experience. Time in billions of years, distance in billions of trillions of miles, temperatures in billions of degrees. In the 1960s, the Palomar telescope was receiving light that had left its source a billion years ago.. a billion light years distant…
2.6. By way of actions beyond Earth, the best humankind can do is get to our own moon & back, send probes that take human lifetimes to Mars or Venus or even Jupiter & Saturn, send out radio signals beyond that, peer as best we can from a space station or with the Hubble and other telescopes.
2.7. Jupiter Saturn Uranus Neptune are so large cold and distant from the Sun their atmospheres have hydrogen and helium which hasn’t been allowed to escape. Mercury is so little and close to the Sun it has no atmosphere at all.
2.8. Venus despite its nice name has an atmosphere high in methane & ammonia: no vacationing there for humans, or Mars…both have abominably high surface pressures! Venus & Mars have nitrogen and carbon dioxide. But only our Earth has precious oxygen in our atmosphere…
2.9. Free molecules of oxygen exist only in the atmosphere of Earth… Our special atmosphere keeps us alive — perhaps *only* us alive in the Universe.
2.10. “The world is mainly a vast leaf-colony, growing on and forming a leafy soil, not a mere mineral mass, and we live not by the jingling of our coins, but by the fullness of our harvests. This is a green world, with animals comparatively few and small, and all dependent upon the leaves. By leaves we live.” So noted Patrick Geddes (1854-1932), polymath and friend, admirer, biographer of JC Bose (1858-1937) inventor of radio and pioneer of plant physiology.
2.11. Oxygen from plant photosynthesis is the source of life on Earth. Thence TW Schultz quoted the Mayers: “Few scientists think of agriculture as the chief, or the model science. Many indeed do not consider it a science at all. Yet it was the first science – Mother of all science; it remains the science which makes human life possible”. Farming before physics. Photosynthesis before farming. “By leaves we live”. No human life without food or free oxygen molecules in the atmosphere.
2.12. Eugen Glueckauf “The Composition of Atmospheric Air” in Compendium of Meteorology TF Malone (ed) 1951 reported the composition of Earth’s lower atmosphere as Nitrogen 78.084, Oxygen 20.946, Argon 0.934, Carbon dioxide 0.033 adding to 99.997% plus trace gases… An increase from 0.033 was predicted at 2-3% per decade of CO2 due to the “rapid burning of the Earth’s reserves of organic fossil fuels…though the data are not entirely conclusive”, noting “there is considerable local variation of CO2 due to localized sources and sinks”…
2.13. In “Atmospheric Composition” in Fundamentals of Physical Geography, 2nd Edn 2006 we’re told by M. Pidwirny the composition is Nitrogen 78.08 Oxygen 20.95 Argon 0.93 Carbon dioxide 0.036. Presumably meteorological data exist on the composition of the atmosphere measured every year at many points of the Earth.
2.14. DH Lawrence claimed “the novel is a greater invention than someone’s telescope”… a curious enigmatic statement. Anna Karenina a greater invention than the Hubble telescope, or even Galileo’s? Phooey…!?
2.15. But there’s this paradox too: since the time of Faraday, humankind has made astounding technological & economic progress due to applications of physics: electric power, internal combustion engines, electronics, satellites, telecommunications, pharmaceuticals, etc. Still we are completely impotent outside Earth’s atmosphere and orbit!
2.16. Both paradoxes may have the same solution. Physics is so brilliant on and about life at home on Earth and so powerless beyond Earth because physics itself depends on life, food, leaves, on precious oxygen. Lawrence is saying human life is more important to us than what happens on Alpha Centauri or Saturn.
2.17 We think there has to be other intelligent life in the Universe because we know it to be unimaginably vast. But it is not impossible we are alone. As far as we know, we are alone. Everything has been in subtle equilibria for photosynthesis and life here to have arisen…Yes there’s the genius of James Lovelock too giving us the “Gaia hypothesis”.
2.18 If we are alone (as is my surmise) the responsibility to preserve our knowledge for when we are extinct is vast…Little sweet Mother Earth ruled over by the hominid homo sapiens may be the centre of not just this small solar system but the Universe itself.
Chapter 3 Facts, Hypotheses, and Guesses
3.1. A scientific fact is something for which the evidence is overwhelming, to deny which would be naive or foolish or unreasonable.
3.2. Two central facts of physics established over the centuries are the heliocentric solar system & the spherical Earth (its curved surface).
3.3. Other scientific facts we certainly know today include that we inhale oxygen needed for our metabolism and exhale carbon dioxide as a waste, that oxygen enters & carbon dioxide exits through the lungs, that both are transported everywhere in our mammalian bodies by the blood pumped by the heart, and so on.
3.4. It is best to keep quite small the number of such illustrations of certain scientific knowledge for reason of Rutherford’s Common Man: “An alleged scientific discovery has no merit unless it can be explained to a barmaid”. What the barmaid and Rutherford share is rationality, reasonableness, comprehension, language. Perhaps pubs in college towns should supply bartenders to witness doctoral viva voces in science and everything else…
3.5. Chapter 6 of my 1989 Philosophy of Economics is titled “Expertise & Democracy”. It doesn’t say the Common Man should judge quality but that the road for the Common Man to do so should be open. The road to judge whether an advance has been made, a contribution to knowledge, new facts established, should be open to everyone including Rutherford’s barmaid.
3.6. Many people have not thought about the flatness or curvature of Earth’s surface, nor know about their own respiration & metabolism. (The easiest way to improve a nation’s health incidentally, may be by greater general understanding of the science of respiration, metabolism etc.) Many people especially in India & China endorse a geocentric solar system today when they act as they do believing in astrology’s horoscopes. (Astrology could be only a trivial pastime, or at least we have to hope so as believers may include those purporting to science!) Russell cynically said “Many people would sooner die than think, in fact they do”.
3.7. Other facts can be deduced or conjectured from central facts like heliocentrism. Eddington noted we are transported by the Earth & Sun: the Earth as our vehicle we travel at 20 miles per second around the Sun which in turn carries us at 12 miles a second through the galactic system, which carries us at 250 miles a second amid the spiral nebulae…
3.8. Eddington’s 1927 Gifford lectures *The Nature of Physical Reality* had a laudable if unsuccessful aim of expressing in words Electromagnetism, Relativity, Entropy, Gravitation, Quantum Theory, all the new physics! A member of the audience asked about relativity “You must find the journey between Cambridge & Edinburgh tiring. I can understand the fatigue if you travel to Edinburgh but why are you tired if Edinburgh travels to you?”. Physics isn’t without its humour. Eddington had to reply, “If motion could tire, we ought to be dead tired” referring to our carriage by the Earth, Sun, galaxies.
3.9. Beyond relatively few central facts, physics has uncountable multitudes of “surmised facts” consisting of hypotheses & conjectures, guesses & speculations.
3.10. Boundaries between facts and hypotheses or between hypotheses and guesses need not be hard and fast or dogmatically precise… We can always ask in a given case, is this a known accepted fact or a surmise or just an informed guess, what is the situation? Earth’s curved surface or the heliocentric solar system are established facts; Eddington’s calculations of speeds at which we travel thru galaxies are less so.
3.11. Between hypotheses and guesses the boundaries may be imprecise again but with a broad difference: With guesses there is no known empirical or even conceptual test available or possible, with hypotheses some test giving a yes/no answer may be possible.
3.12 At least 1/3 of all stars is a “double” or two stars together with no planets, reports Eddington from the important research of his colleague JH Jeans. Jeans concluded double star formation to be typical, formation of a solar system to be “a freak”. Jeans’s theory of our solar system’s formation is that a thousand million years ago another star passed not far from what became the planet Neptune, this star passing by caused “big protruberances” of the Sun, big enough for the formation of the planets by eruption from the Sun.
3.13. JH Jeans’s description of how another star once passed by our Sun causing it to disgorge the planets of the solar system is a guess or speculation which can’t be empirically tested.
3.14. Yet Jeans’s guess is reasonable & comprehensible, following as it does a line of reasoning from less uncertain facts. As such it is more plausible than if we instead guessed the planets emerged because the Sun sneezed like a human.
3.15. Jeans and Eddington concluded the chances of planets arising from any star are remote. Compound that with the chances of water, photosynthesis, oxygen, life arising, and the likelihood of a Da Vinci elsewhere in the Universe becomes remoter still. Humankind may be alone (is my surmise)!
3.16. A contemporary view from Helen Klus is “There may be millions of other planets in our galaxy that contain life”. If so Jeans and Eddington were wrong, and I too to believe them.
3.17. Popper proposed we try to falsify our guesses and findings to come to know what is scientific truth at a given time, that we adopt a critical attitude to our own and others’ scientific claims. Everything we think we know we seek to re-examine critically if we are to progress with and advance our knowledge.
3.18. Jeans conjectures a star passed by causing the Sun to disgorge planets a 1000 million years ago? Popper says look at the reasoning and facts again.
3.19. A youngster is sceptical seeing a ship disappear over the horizon. Good. Bring him/her back the next day & the next, to see more ships doing the same… But how do we know the ships aren’t just falling off the edge? the child asks… Excellent question… Let’s take a helicopter, chase after it. Or imagine we do so notionally if we can’t afford one. “We haven’t got the money, so we’ll have to think” (Rutherford). Ok, says the child, I accept the Earth’s surface seems curved in this region, but how can we tell it is so everywhere? To Jules Verne!
3.20. The vast bulk of physical facts may be surmises midway between guesses/speculations on one hand, and known central facts on the other. This bulk of surmised facts I describe as hypotheses/conjectures open to hypothesis testing: offering yes/no results to empirical or even just conceptual experiments…
3.21. Heisenberg’s “thought experiment” led to his declaring we can know the location or velocity of a particle as precisely as we want but not both together at the same time… Heisenberg’s superb *Principles* is the exemplary doctoral thesis of the star pupil of Sommerfeld… You describe one two three four extant empirical experiments that you say everyone finds puzzling, inadequately explained, anomalous…You provide your criticism of the existing theory or theories used in these experiments, then propose a theory to replace them…Then you discuss possible criticisms and extensions of the theory you’ve newly offered. Then apply it to reexamining the original empirical experiments. Finally you place in an appendix the “Mathematical Apparatus” you’ve used, mathematics in its place as the servant not master of physics.
3.22. Heisenberg admits with utmost honesty after all his new theory that most of the empirical experiments remain explicable classically!
[GEMoore: “You aren’t denying the electron exists, you’re saying we can’t tell where it is.”
Heisenberg: “Exactly so! (Well, almost!)”.]
3.23 Eddington suggested a “thought experiment” of an empty vessel with a sliding door halfway: in the left half is air; the closed right half is a vacuum; opening the sliding door causes the air molecules to diffuse thru the vessel, hitting each other & the walls randomly, never again congregating back to the initial left side. Eddington used it to show increasing entropy, “the running down of the Universe”, a “loss” in the initial “organization” of the molecules..
3.24. Complicated experiments on a hard subject were those of Clauser, and later Aspect, seeking to test Bell’s theorem in the contest between Einstein and the Quantum Mechanics of the “Copenhagen School”. The latter “won”, for the time being at least. But Popper’s scientific method would require them and everyone else to think again! Try to refute your own findings! Was Bell’s theory adequate? Were the Clauser and Aspect experiments adequate?
3.25. John Wisdom gave a deliberately easy empirical experiment with a yes/no answer: a room seems empty, nothing to see feel hear smell taste in it. A declares “It’s empty”, B declares “It’s not”, throws a lighted match in it, there’s an explosion. “Gas” says B….
3.26. Empirical questions should be nice enough to provide us a binary choice of answers: Yes/No; True/False; or, if we like, probability ≈ 1 probability ≈ 0. Until a binary choice is available the question is not purely empirical but still theoretical. John Wisdom was keen to argue that even *after* all facts, all empirical results, are in, there may still not be a conclusion until we have *reflected* about all that’s before us.
3.27 Other than probability ≈ 1, probability ≈ 0, the only probability number of interest is the halfway point 0.5, which is, as it were a point of “Ignorance” or “Indifference”, an *unstable* point which must move either towards 1 or towards 0, ie towards certain knowledge in one direction or other.
3.28. I suggest physics define
probability ≈ 1 as our *rational degree of belief* in the heliocentric solar system,
probability ≈ 0 as its contrary….
Or we can normalize with probability ≈ 0 as the Earth being flat, probability ≈ 1 its contrary.
3.29. JH Jeans’ surmised description of the formation of the solar system (of how another star once passed by our Sun causing it to disgorge the planets) is a guess we may place at probability = 0.5.
3.30. My proposal is, in other words, that we calibrate our rational degrees of belief by certainty eg heliocentrism prob ≈ 1, by JH Jeans’s Guess prob =0.5, and a lower limit of certainty again prob ≈ 0 eg the Earth being flat.
3.31. Certain knowledge prob ≈ 1 is not “absolute knowledge” prob = 1. Our slogan remains “This is where we got to”. It is not *logically* impossible Copernicus & everyone got it wrong… Before Copernicus, Ptolemy was certain knowledge. What can be certain knowledge in one era may be expected to change as evidence advances with time.
3.32. Calibrating with certainty prob ≈ 1, a Guess prob=0.5, a lower limit of certainty again prob≈0, every other case must be compared and contrasted to these three in turn. Moving from a Guess at probability 0.5 positively towards certain knowledge prob ≈ 1 or negatively towards certain knowledge prob ≈ 0 is the process of hypothesis testing given improving evidence. Our confidence in our belief increases away from 0.5 towards 1, or decreases away from 0.5 towards 0… call it positive, negative confidence respectively.
3.33. A person applies for a job, he’s at 0.5, doesn’t know if he will get it…As evidence improves his confidence moves positively towards 1 or negatively towards 0. The initial Ignorance point 0.5 is unstable: it’s as if the 0.5 point belongs to Leibniz and movement in directions positive to 1 or negative to 0 both belong to Bayes.
3.34. We may have the rudiments of the probability theory that eluded Keynes Ramsey de Finetti Good etc…who may have at different stages in different ways confused objective and subjective. (In turn, Quantum Mechanics theorists, not having time to investigate probability themselves, may have confused themselves with the dogmas of probability theorists!)
3.35. Ramsey said we bet all the time in life: we go to the railway station betting the train will depart…or we would have stayed home… In my terms we go to the railway station betting the train will depart because we place the probability above our JH Jeans Guess of 0.5, below the probability of heliocentrism ≈ 1
3.36. Two commuters place a probability 0.9 each day of the train departing; one day A doesn’t turn up, B does & finds the train doesn’t run. B asks A the next day, she says yes my son told me the train wasn’t going to run because there’d been a mishap down the line so I stayed home. A’s assessment of the evidence had changed due to the new information hence her rational degree of belief, her probability, changed too… In Bayesian terms, A’s “prior probability” 0.9 the train would run crashed to a “posterior probability” ≈ 0 based on her son’s information.
3.37 From the Ignorance point 0.5 we act in one direction as prob -> 1, we act in the opposite direction as prob -> 0. Our confidence in our belief increases away from 0.5 towards 1, or away from 0.5 towards 0… positive or negative confidence.
Alternatively, the 0.5 point is a point of Ignorance, 1 and 0 are the points of Rational Belief and Rational Disbelief respectively….
Alternatively, probability 1 is T in “truth tables”, probability 0 is F…. 0.5 is, say, I for Ignorance or Indifference, an unstable point, moving with learning towards either T or F.
Rational Belief______Ignorance_______Rational Disbelief
Probability ≈ 1 = 0.5 ≈ 0
True T Ignorance I False F
We rationally believe in heliocentrism, rationally disbelieve the Earth is flat, & we guess JH Jeans’ theory of planet formation is correct. Once we have three such points, every other case of belief/disbelief that arises for anyone may be compared & contrasted with each of these
3.38 The 0.5 Guess point is the unstable one of “insufficient evidence”; moving in either direction increases evidence with hypothesis testing. Moving from a Guess at prob 0.5 positively towards certain knowledge prob ≈ 1 or negatively towards certain knowledge prob ≈ 0 is the process of hypothesis testing given improving evidence. “It is wrong in all cases to believe on insufficient evidence…” said Clifford. (Clifford, dead at 33 in 1879, the same year Einstein is born, anticipated Einstein on gravitation by a generation, and Einstein knew it in his Berne years.)
3.39 Games of chance like rolling dice or choosing a card from a shuffled pack are artificial human contrivances to simulate states of ignorance.
In my terms, a 6-sided fair die before it is rolled would be represented by a six element vector (0.5, 0.5, 0.5, 0.5, 0.5, 0.5); its possible outcomes are the rows of a 6×6 identity or unit matrix (1,0,0,0,0,0), (0,1,0,0,0,0), (0,0,1,0,0,0), (0,0,0,1,0,0), (0,0,0,0,1,0), (0,0,0,0,0,1).
With 52 cards, obviously if we know the initial order & how precisely it is shuffled (say in slow motion by a machine) we know the new order. Our ignorance is deliberately contrived in a pack of cards to create randomness & chance for amusement; it may be a mistake to think nature is like that.
In a randomly shuffled pack, what is the top card is in my terms a 52 dimensional vector of (0.5) s, 52 possible results by a 52 dimensional identity or unit matrix.
The 0.5 would still represent the halfway between 1 and 0 in each case but otherwise = 1/6 is an ex ante “probability” in case of the die, 1/52 in case of the cards.
3.40 Einstein saying (if he did) of Quantum Mechanics “God does not roll dice” may have just meant to say: “Don’t confuse our contrived games of chance for our real ignorance of Nature…!”. Max Born, Heisenberg and others may have tossed in prevalent probability ideas/dogmas without having the time to think them all through…