8 Theories - PREFACE It is surprising and a bit daunting to have 19 people sign up for this course already! This u3a course was motivated by Raymond Hall, but he let me organise and present it. For years he has been pressing physics books on me when we meet for Taree Club Band rehearsals. It had been 50 years since I did a degree in physics and since then we have had black holes, many new particles, new ideas of cosmology, and even gravity waves which were regarded as too weak to ever detect when I was at Uni. Although quantum mechanics was discussed, ideas of reality were downplayed and the Schroedinger equation was regarded as an imponderable mathematical trick. I failed physics 2! I was dragged back to revisit physics as part of an electronics degree and found solid state physics 3 interesting. Since then the interpretations of physical reality have continued to vary. Einstein died failing to disprove Quantum Mechanics in spite of clever "reductio ad absurdum" constructions like the EPR paradox. The continuing attack on QM led to more mysteries such as Bells non locality assumption. The other thing that has happened since I studied physics is that the "zoo" of fundamental particles is looking worse than the Periodic table of elements in 1750. There are patterns there, but the best theory to explain them is the problematic String theory with its invisible dimensions and ambiguous formulation. The book "Quantum Reality" by Nick Herbert finally provoked me to present this course. It bravely faces the dissolving borders between philosophy, physics and theories of mind. I will bring a wheelbarrow load of other books to the course as well - a sort of temporary lending library. The form of the course that I envisage is two short lectures in each session with big diagrams up front and handout notes. These will be followed by Q&A sessions with answers by me or anybody in the class who can do better. Due to Covid 19 restrictions you will have to bring your own refreshments, But I hope the course will be interesting afternoon tea entertainment. ******************************************************************** 8 theories of reality - TIMELINE session1, 10/02/2021 They say "In the beginning was the word" and one thought experiment of mine is of a child marooned on a desert island with no language - what theories of reality would be possible? I suspect continuity of objects, up/down/NSEW, sinking/floating, falling, hot/cold, tides, rain, wind etc. Along with theories of reality has been the fellow travellers of language and mathematics. There have been many theories of reality, from a flat earth with turtles all the way down, to flat earth with celestial spheres, to earth wind fire, water theories, and many creation myths. Heaven was regarded as part of reality and even the underworld by many cultures. But with the Renaissance came a drawing together and systemetising of parts of the world under "laws" and "rules" of optics, geometry, astronomy, chemistry, and biology. These laws seemed to offer a level of truth that did not bow down to power, tradition, intuition and "common sense". Religion fought this march of experimentation over gate keepers of holy books, but had to gradually had to retreat into the interpretation of many texts as metaphor parable, or magic. God of course still had a place as the creator of these newly discovered laws of science. Copernicus, Gallileo, Michelangelo, etc showed theories of reality that were shocking but beautiful. The power of simple physical generalisations to explain, predict and simplify led to an increasing agreement about reality. A classic example is Newtons laws of motion (F=ma), and gravity (F=Gxm1xm2/r2) which reduced to simple mathematics such imponderables as planetary motion, tides, and of course the design of guns! The sacrifice of intuition regarding a flat earth was well worth it. We still have some who have the idea of a flat earth as part of their reality but not many, and they happily use GPS to get around on it! Science marched on through the 1700's and 1800's with triumph after triumph, often hard won and requiring dedicated and brilliant people who often came to bad ends. The pattern of investigation was driven by an urge to simplify and unify things which appeared chaotic and different. The motion of the planets became easy to predict and even "understand". Chemistry became described by the extremely useful Periodic Table and the efforts of alchemists to turn lead into gold were doused. Electricity and magnetism were unified by the very poetic equations of Maxwell who went on to recognise that light was made of electric and magnetic fields and only a special case of radio waves, heat radiation and Xrays. The magical fluid that described heat turned out to be the contagious entropy of vibrations and not really distinct from sound, except in frequency and spectrum. When properly described by heroes like Carnot we saw the development of efficient steam engines and (for the most part!) the dropping of efforts to build perpetual motion machines. There are still the Carnot deniers unfortunately who think physics should work in the way they think the economy does, ie that money makes money. The upshot of these highly unifying theories of physics was the invention of useful technologies that stoked (literally) the wealth of the industrial revolution, and also facilitated the exploitation of colonies. Each of these great unifications not only shocked the common sense of the time, but also drove the expansion of mathematics needed to describe these unifications. For example the unification of algebra and geometry forced Pythagoras into contemplating the answer to the question "what number multiplied by itself = 2 ?" The unification of the heavens and earthly machines forced Newton to invoke Calculus with its functions defined as infinite limits. The unification of electricity and magnetism required differential equations in vector spaces and imponderables like what number multiplied by itself = -1? There is always the suspicion that theories are being driven by pretty maths and that jargon is obscuring meaning. ************ By 1900 Lord Kelvin is supposed to have advised students against studying physics becasue it was "all done except for some better measurements of constants". The next twenty years would dislodge that hubris. It was not the theory of relativity that did the damage, as this theory was like the great breakthough theories of the past that required a gulp of intuition swallowing and the learning of difficult mathematics, but as a prize delivered simplification. In this case gravitational mass and inertial mass were unified. Also that pesky Micheson Morley experiment was explained. It is hard to understand that as recently as 1900 the atomic theory of matter was not considered respectable, and people were criticised for going too far in their papers by suggesting that atoms were more than a mathematical abstraction to facilitate calculations in chemical reactions etc. Strong hints like fixed combining ratios were considered possibly as misdirections. I remember as a student at Taree High School that the theory of continental drift was considered "poetic". And of course my great uncle who worked in the Redhead mine and saw fossilised plants was told by church luminaries that these records were put there by god to test his faith ... The world is only 5000 years old. ***************************************** But the evidence that dragged the world view towards matter being made of particles mounted from many directions: * the enormously successful kinetic theory of gasses that envisaged molecules as flying around at hundreds of Km/hr and bouncing off each other and the walls of containers. * Brownian motion- you can actually see pollen grains in water being buffeted around by random collisions * the discovery of the electron, driven out of metal and flying around like a bullet until it hits something * the photoelectric effect: that these electrons can be driven out of a metal by light with energy not relateed to the brightness of the light but its colour! * And the light that comes from a red hot iron has a colour spectrum that can only be explained by assuming it to be made of emissions from many small sources and only in specific energies. Bohr hypothesised an atom in which an electron resides for some reason in only particular states. He had no reason to explain this except that it gave the observed results. This was the beginning of the quantum revolution. That was the start of the 8 theories, or even more possibly. **************************************************** SESSION 1 REVISION The key points I tried to make in session 1: 1/: The renaissance brought a restive spirit and a willingness to put accepted and intuitive ideas to experimental test. This led to surprising and effective new theories. 2/: Brilliant theorists developed ways of bringing apparently different phenomena under the same roof. Heat, motion, gravity, magnetism, electricity, chemistry, optics, sound, etc. 3/: Increasingly precise language was developed to draft these theories, such as the word "entropy" and the mathematics of calculus. 4/: Just when Physics was "all worked out", clouds appeared on the horizon. Things we considered continuous like light turned out to be quantised. Things we considered to be indivisible and perfectly defined entities like electrons turned out to behave like waves sometimes. The perfect clockwork of a deterministic universe "out there" was shown to be probabalistic and observer dependent. 5/: The two slit experiment, demonstrated, showed that somehow a particle of light becomes a wave when it goes through two possible paths, and then become a particle again when detected in a position subject to a probability formula, not a mechanistic prediction. SESSION 2 will begin with one of the clouds on the horizon - the way hot things radiate light. How Plank was dragged screaming to the idea of an atom, and the quantisation of light. Then followed the surprising explanation of chemistry , spectroscopy, and the advent of the highly usetting Heisenburg Uncertainty principle. The first theory of reality will depend on this. ********************************************* u3a session #2 8 Theories of Reality 24th/Feb 2021 1:30 pm REVISION: Class reaction to the main points of last session This will be a difficult session, but we will get to three of the theories of reality. The development of quantum theory became a time of imponderables, ad hoc rules, animosities. While starting the quantum story Einstein dragged his feet and tried to unpick the theory the rest of his life. It is 1900 and more clouds gather on the horizon of science. Professor Plank, happy with his theory of entropy applied to gases and heat, tried to explain the empirical law that described the colours given off by hot objects. This was the age of the electric lightbulb of course. Plank found that the current formula was slightly wrong and had no theoretical basis! He invented a better formula that worked but could find no sensible derivation of it. In desperation he eventually went to his adversary Boltzman (who had a scandalous belief in atoms) and eventually had to posit the existence of oscillators containing electrons that were "quantised" in the sense that they could only oscillate at preferred energy levels of hf, 2hf, 3hf where h was the famous constant we call Planks Constant which appears all over quantum physics. The idea of the atom was gradually getting more accepted and a telling experiment by Rutherford had particles which mostly went straight through a gold foil being occasionally deflected, and even bouncing straight back! The only interpretation was that the atom was mostly empty space and the part that reflected his heavy particles was only about 1/10,000 the size of the atom. So the electron seemed to roam around throughout the atom and the the positive nucleus just sat in the middle. This was a mystery as if the electron was in orbit, then it would radiate light in a big way as all circling electrons do (eg as in a mobile phone transmitter). Bohr made the very productive suggestion that for some reason only particular orbits were allowed and these were prevented from radiating. This fitted in with Planks quantised oscillators. A very satisfying outcome of this is that a surprising explanation appeared for the mysterious way different gases can be stimulated to emit coloured light (eg the yellow sodium light, the green/blue mercury light). Moreover these colours were specific lines, not a continuous rainbow when seen through a prism. The light from Hydrogen had even been examined by Balmer who came up with a formula predicting the sequence of colours. Prince De Broglie now rides in from left field. His poetic idea was that if light seemed to have a particle/wave nature then maybe other things do also. And Heisenburg came up with his very indigestible formula which looks like a typical measurement error equation; precision in momentum x precision in position > h. While his derivation was a "disturbance" concept - very little things are going to be upset by the light you use to measure where they are - he went on to claim that greater accuracy in reality than his formula was unknowable, or even non-existent. This is the copenhagen theory 1 & 2 of reality. There are various ways of approaching the Uncertainty Principle but they all agree. The idea that the world is not a beautiful clockwork, but more like a dice game has lots of implications like the end of causuality. The difference between Copenhagen 1 & 2 is whether what happens at a quantum level is non-existent or just unknowable. "Shut up and calculate" seems to be the take-away. Outcomes are all that matter from any quantum event and the odds are able to be worked out. This all relates to the wave nature of particles where constraining a wave to limits places other measurements more vague. This "wavy" state of particles was wonderfully formalised by Shrodinger with his very wonderful equation. It posits the existence of a wavefunction that exist in space and time and which allows superposition - these matter waves can go through each other, and interfere with themselves as in the two slit experiment. But even the maths of this famous equation is hard to interpret. the solutions are difficult to solve and yeild time and space descriptions of matter that are dependent on the situation, and smeared out, and expressed as a complex number at each point in space. For those that dont know a lot of maths, this means that there is a spooky invisible quantity everywhere. If you square the value of this wavefunction at every point you get rid of the complex numbers and get the "probabability of existence" of the particle at that point. Yes, tenuous. But the description of what happens spat out by this maths is correct! As an example, it describes how an electron can sit in an atom in different states and if you invoke the Pauli exclusion principle it can yeild the Periodic Table of Chemistry! No mean unification. My feeble demonstration of the ambiguous state of matter with the two slit experiment undersells the scale of the problem with particle/wave ambiguity. Can I repeat it with drama thus: 10 Billion years ago in a star that probably does not still exist, a photon (particle of light) emerged from an atom in the corona of a star. Eventually it appears as a wave at Earth and "decides" to land on a supercooled light receptor in a telescope, suffering red shift, gravitational lensing, and manages to shift an electron into a conduction band. Nick describes the quantum collapse as from a thing as big as the earth to a single atom in an instant. The theory of the electron was very much that it was a particle. Old fashioned TV screens shot electrons at the screen through screens that achieved colours based on the idea that electrons shot in straight lines from the electron guns. I plan to demonstrate this in class and show that the electrons are behaving as charged bullets by torturing a CRT with a supermagnet. But interference experiments can be constructed to show that an electron has a wave nature. It was first noticed when 55ev electrons were shot at a crystal of nickel, the distance between atoms forming a interference grating. Note that in my TV screen the electrons are going VERY fast, accelerated by 15Kv, 1/100 the spped of light. No wonder they go like bullets. *********************************************************************** u3a session #3 8 Theories of Reality 10th March 2021 1:30 pm The last session developed the idea of a "wave function", well described mathematically, but hard to imagine. It successfully explains many things, such as the behaviour of electrons in atoms and the interference effects such as the two slit experiment. By way of revision we can consider a dramatic example of this formulation of matter by describing the strange telescope at Narrabri which measures the apparent size of stars, not just their brightness. It is not possible to do this with an ordinary telescope because except for the sun they all just look like points of light. Even the sun is surprisingly only half a degree accross. The nearest star is nearly a million times further away. The way the Stellar Interferomenter works is by having two big convcave mirrors on two railway carts that can move apart up to 100 metres, yet have their focus on the same star and the phase of the light correlated so as to reveal an interference pattern when one wavefunction intercepts both detectors. A photon can of course only end up in one of the detectors, but the interference pattern affects where it lands. By moving the mirrors apart the size of the wavefunction can be measured. This is inversely related to the apparent size of the star. Betelgeuse is a red giant and its wavefunction is only 4 metres accross. Zeta Orionis sends wavefunctions over 100 metres in size. This is predictable from Heisenburgs uncertainty principle that says photons in such a narrow beam must have very closely defined momentum, but thus poorly defined position. Surprisingly the thickness of the arriving wave is only microns. As Nick Herbert says, photons from such distant sources are very big flat pancakes! EPR! For years after the formulation of Quantum Mechanics, and the elegant expression by Schrodinger, Einstein and a few others had niggling worries about it. There were only probabalistic outcomes predicted, and there was this strange business of a wave suddenly turning into a particle when measured. How was Heisenburgs Uncertainty Principle to be understood; were accurate attributes of a particle not existing, not measureable, or chosen at point of measurement by the particle depending on what was being measured? Einstein liked saying God does not play dice (actually how can she, being omnificent!) He was seen by the Copenhagen school as too slow to accept the wonderful predictions of quantum mechanics and to forget its counterintuitive nature. It was pointed out that Einsteins general relativity was extrememly counterintuitive. He simply quipped that a good joke should not be told twice ...! But Einstein disturbed the Physics community with a paradox: If two particles come from one quantum event they have to be equal and opposite by conservation of angular momentum, energy etc. If you measure one then you must know exactly what the other one's properties are! Even if it flies for years before being measured it will seem to prove that it had attributes all along, rather than making them up at the point of measurement. Moreover it knows which attribute was measured in its partner, even though communication was impossible. He claimed in his paper that Quantum Mechanics must be incomplete. Bohr countered with a rather wordy and opaque "explanation" of the EPR paradox along the line that both particles were really one waveform and the measurement of either was part of the experimental setup. The thing was regarded as metaphysics in any case - untestable. The famous Von Neuman had written a proof that no hidden variable (extention to QM) was possible. EPR stands for Einstein Podolsky & Rosen. Part of the dismissal of the the paradox was because Podolsky and Rosen were both of low status in the Physics community and seen as being used by Einstein to make trouble. One from southern Russia and one from Brooklyn! It was not till 1952 when Bohm, thrown out of USA by the Committee on Unamerican Activities worked on a hidden variable theory that particles were always particles, and guided by a real "pilot" field that told them were to go. There was no idea how to test this until a shocking and again largely ignored proof in an unfashionable journal was produced by John Stewart Bell, an upstart from Belfast. He pointed out in 1965 that there was a way to experimentally test whether particles had attributes before they were measured. The proof seemed little more than a card trick or a thought experiment. It still seemed all a lot of metaphysics and philosophy until John Clauser, getting no support from Columbia moved to Berkley where there was equipment which could actually do the experiment. In 1972 he published his result. Quantum Mechanics was right, Einstein was wrong. Not the result he expected. Not only do particles not know what their attributes are until measurement, but they must refer at superluminal speed to their entangled twin before presenting their attributes!!! This result remains disputed to this day, even though better and better experiments continue to confirm it. Even WIKI says this information is challenged! There is quite a history of physicists hating non-local influences. Newton called mysterious non local connections "so great an absurdity" (though he was pretty quiet on his own magical force, gravity). It all sounds like Voodoo, Homeopathy, and the idea of contagious magic is big in Wicker. Surprisingly the spooky instantaneous action at a distance makes little diference to the 8 Theories! *The Copenhagen views simply say what is the problem? *The #3 theory is almost happy about it. *In Everetts many world reality you cant even prove Bells Theorem. *If you are going to trash Boolean logic then you might not be able to prove Bells theorem, but the theory depends on measurement so you have to tear down a lot of quantum mechanics. *Neorealism takes a hit as it has to build a theory of these superluminal fields. * Not only is psychokinesis implied by this theory but now instantaneous universe wide control! * Possibly consistent. FASTER THAN LIGHT SIGNALLING This apparent secret instant knowledge between widely separated particles surprisingly does not permit signals to be sent. The reason is that both detectors see a random sequence of results. Even if one detector reversed all results in the other, how would it know? You cant decode a random string of data without a key, and how would you get that? One random string is indistinguishable from another. So you can SEND messages faster than light, but nobody can understand them! AFTERTHOUGHT: Bells Theorem is a Reductio ad Absurdum proof because he starts with simple axioms and gets a contradiction. The best candidate for error in his assumptions is locality. There is a long history of such proofs, some valid and some not. Zenos paradox for example is not valid because it assumes an infinite sequence cant converge. Another famous one is Godels theorem about well formed questions in mathematics that are true but cant be proved to be, in a finite process. This all brings up the infamous Rumsfeld speech about known unknowns, and unknown unknowns. GOODBYE Thanks for your support of this rather information packed course. Hopefully you will be now more across the gigantic shift in world view that Quantum Theory has brought. It gives a foundation to understanding things as diverse as Cosmology, Global Warming, Solar panels, Computers, Cell chemistry, Fibre Optics, ... Quantum Theory is not just important for being the basis of a third of the worlds economy, but in this world of spin and conspiracy theories it is so important to look at the known knowns that so few people know about! ************************************************************************** APPENDIX 1: These books were made availiable at the 8 theories course. They vary from readable to impossible. HERBERT N Quantum Reality Anchor Books, Random House 1987 KUMAR M QUANTUM Icon Books Ltd 2009 AL-KHALILI J QUANTUM A guide for the perplexed Orion House 2004 GREEN B The Fabric of the Cosmos Penguin Books 2005 COLLIER P A Most Incomprehensible Thing Incomprehensible Books 2012 BERNACCHI G Tensors Made Easy http://www.lulu.com 2019 LIDDLE A & LOVEDAY J Oxford Companion to Cosmology Oxford Paperbook Reference 2009 COX B & FORSHAW J The Quantumm Universe: Everything That Can Happen Does Happen Penguin Books 2012 RESNICK R & HALLIDAY D PHYSICS John Wiley & Sons Inc. 1960 SIMMONS G.F. Introduction to Topology and Modern Analysis McGraw-Hill Book Company Inc. 1963 HANSEN C.J. & KAWALER S.D Stellar Interiors Springer-Verlag 1994 GRIBBIN J. In Search of Schrodingers Cat Black Swan reprinted 2012 WILLIAMS R. Ockham's Razor ABC 1991 SINGH S. Big Bang Harper Perennial 2004 WILLIAMSON R. CROWELL R. & TROTTER H. Calculus of Vector Functions Prentice Hall 1968 ESCHER M.C. The Graphic Work of M.C. Escher Oldbourne London 1970 ROSENBLUM B. & KUTTNER F Quantum Enigma Duckworth & Co 2011 ORZEL C. How to Teach Quantum Physics to your Dog Oneworld Publications 2011 BAGGOTT J. The Quantum Story Oxford University Press 2011 SUSSKIND L. The Cosmic Landscape Black Bay Books 2006 PENROSE R. Fashion Faith & Fantasy Princeton University Press 2016 MENDELSON B. Introduction to Topology Blackie & Son limited 1963 ******************************************* APPENDIX 2: EXPERIMENTAL GEAR for Youngs 2 slit experiment a laser pointer from Officeworks and a smoked peice of glass and a blob of bluetack. For Brownian Motion a botle of turps with a couple of drops of Silver Frost. It had to be real enamel, not acryllic spray can. Illuminated with the same laser pointer. Magnetic field visualisation was with NeFeB motor magnets and an old B&W cathode ray tube. Electric field visualisation was with discharge sparks from a mosquito wand. Ray tried to get a photoelectric effect demonstration with a UV water purifier but it was very wet weather and he could not get the voltage. The whiteboard in GGA was useful for diagrams of incidental questions , such as regarding Maxwells demon, string theory, The Flipchart commentary was good in that time was not wasted in class with writing. The photos appear in a following file. APPENDIX 3 MUSIC ...Galaxy song by Monty Python Whenever life gets you down Mrs. Brown And things seem hard or tough And people are stupid, obnoxious or daft And you feel that you've had quite enough... Just, remember that you're standing on a planet that's evolving And revolving at nine hundred miles an hour That's orbiting at nineteen miles a second, so it's reckoned A sun that is the source of all our power The sun, and you and me, and all the stars that we can see Are moving at a million miles a day In an outer spiral arm at forty thousand miles an hour Of the galaxy we call the Milky Way Our galaxy itself, contains a hundred billion stars It's a hundred thousand light years side-to-side It bulges in the middle, sixteen thousand light years thick But out by us its just three thousand light years wide We're thirty thousand light years from galactic central point We go round every two hundred million years And our galaxy is only one of millions of billions In this amazing and expanding universe The universe itself keeps on expanding and expanding In all of the directions it can whiz As fast as it can go, the speed of light you know Twelve million miles a minute and that's the fastest speed there is Woodstock by Joni Mitchell I came upon a child of God He was walking along the road And I asked him where are you going And this he told me I'm going on down to Yasgur's farm I'm going to join in a rock 'n' roll band I'm going to camp out on the land I'm going to try an' get my soul free We are stardust We are golden And we've got to get ourselves Back to the garden Then can I walk beside you I have come here to lose the smog And I feel to be a cog in something turning Well maybe it is just the time of year Or maybe it's the time of man I don't know who I am But you know life is for learning We are stardust We are golden And we've got to get ourselves Back to the garden By the time we got to Woodstock We were half a million strong And everywhere there was song and celebration And I dreamed I saw the bombers Riding shotgun in the sky And they were turning into butterflies Above our nation We are stardust Billion year old carbon We are golden Caught in the devil's bargain And we've got to get ourselves back to the garden. ****************************************************