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Christoph Schiller
MOTION MOUNTAIN
the adventure of physics – vol.vi
the strand model –
a speculation on unification
www.motionmountain.net
Christoph Schiller
Motion Mountain
The Adventure of Physics
Volume VI
The Strand Model –
A Speculation on Unification
Edition 25.34, available as free pdf at
www.motionmountain.net
Editio vicesima quinta.
Proprietas scriptoris © Chrestophori Schiller
primo anno Olympiadis trigesimae.
Omnia proprietatis iura reservantur et vindicantur.
Imitatio prohibita sine auctoris permissione.
Non licet pecuniam expetere pro aliqua, quae
partem horum verborum continet; liber
pro omnibus semper gratuitus erat et manet.
Twenty-fifth edition.
Copyright © 2012 by Christoph Schiller,
the first year of the 30th Olympiad.
This pdf file is licensed under the Creative Commons
Attribution-Noncommercial-No Derivative Works 3.0 Germany
Licence, whose full text can be found on the website
creativecommons.org/licenses/by-nc-nd/3.0/de,
with the additional restriction that reproduction, distribution and use,
in whole or in part, in any product or service, be it
commercial or not, is not allowed without the written consent of
the copyright owner. The pdf file was and remains free for everybody
to read, store and print for personal use, and to distribute
electronically, but only in unmodified form and at no charge.
To Britta, Esther and Justus Aaron
τῷ ἐμοὶ δαὶμονι
Die Menschen stärken, die Sachen klären.
PREFACE
This book is written for anybody who is intensely curious about nature and motion. Have
you ever asked: Why do people, animals, things, images and empty space move? The
answer leads to many adventures, and this book presents one of the best of them: the
search for a precise, unified and final description of all motion.
The wish to describe all motion is a large endeavour. Fortunately, this large endeavour
can be structured in the simple diagram shown in Figure 1. The final and unified description of motion, the topic of this book, corresponds to the highest point in the diagram.
Searching for this final and unified description is an old quest. In the following, I briefly
summarize its history and then present an intriguing, though speculative solution to the
riddle.
The search for the final, unified description of motion is a story of many surprises.
For example, twentieth-century research has shown that there is a smallest distance in
nature. Research has also shown that matter cannot be distinguished from empty space
at those small distances. A last surprise dates from this century: particles and space are
best described as made of strands, instead of little spheres or points. The present text
explains how to reach these unexpected conclusions. In particular, quantum field theory,
the standard model of particle physics, general relativity and cosmology are shown to
follow from strands. The three gauge interactions, the three particle generations and the
three dimensions of space turn out to be due to strands. In fact, all the open questions
of twentieth-century physics about the foundations of motion, all the millennium issues,
can be solved with the help of strands.
The strand model, as presented in this text, is an unexpected result from a threefold
aim that I have pursued since 1990, in the five previous volumes of this series: to present
the basics of motion in a way that is up to date, captivating and simple. In retrospect,
the aim for maximum simplicity has been central in deducing this speculation. While
the previous volumes introduced, in an entertaining way, the established parts of physics,
this volume presents, in the same entertaining and playful way, a speculation about unification. Nothing in this volume is established knowledge – yet. The text is the original
presentation of the topic.
The search for a final theory is one of the great adventures of life: it leads to the limits
of thought. The search overthrows our thinking habits about nature. A change in thinking habits can produce fear, often hidden by anger. But by overcoming our fears we gain
strength and serenity. Changing thinking habits thus requires courage, but it also produces intense and beautiful emotions. Enjoy them!
Munich, 11 December 2012.
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
8 preface
Galilean physics, heat and electricity
Adventures: sport, music, sailing, cooking,
describing beauty and understanding its origin
(vol. I), using electricity, light and computers,
understanding the brain and people (vol. III).
Special relativity
Adventures: light,
magnetism, length
contraction, time
dilation and
E0 = mc2 (vol. II).
Quantum theory
Adventures: death,
reproduction, biology,
chemistry, evolution,
enjoying colours and
art, all high-tech
business, medicine
(vol. IV and V).
Quantum
theory with gravity
Adventures: bouncing
neutrons, under-
standing tree
growth (vol. V).
Final, unified description of
motion
Adventures: understanding
motion, intense joy with
thinking, calculating
couplings and
masses, catching
a glimpse
of bliss
(vol. VI).
G c h, e, k
PHYSICS:
Describing motion
with the least action principle.
Quantum field theory
Adventures: building
accelerators, understanding quarks, stars,
bombs and the basis of
life, matter, radiation
(vol. V).
How do
everyday,
fast and large
things move?
How do small
things move?
What are things?
Why does motion
occur? What are
space, time and
quantum particles?
General relativity
Adventures: the
night sky, measuring curved space,
exploring black
holes and the
universe, space
and time (vol. II).
Classical gravity
Adventures:
climbing, skiing,
space travel,
the wonders of
astronomy and
geology (vol. I).
FIGURE 1 A complete map of physics: the connections are defined by the speed of light c, the
gravitational constant G, the Planck constant h, the Boltzmann constant k and the elementary charge e.
Using this file
Text in green, as found in many marginal notes, marks a link that can be clicked in a pdf
reader. Such green links are either bibliographic references, footnotes, cross references
to other pages, challenge solutions, or pointers to websites.
Solutions and hints for challenges are given in the appendix. Challenges are classified
as research level (r), difficult (d), standard student level (s) and easy (e). Challenges for
which no solution has yet been included in the book are marked (ny).
This sixth volume of the Motion Mountain series has been typeset in a way that printing the file in black and white gives the smallest possible reduction in reading pleasure.
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
preface 9
Feedback and support
This text is and will remain free to download from the internet. I would be delighted to
receive an email from you at [email protected], especially on the following issues:
Challenge 1 s — What was missing or hard to follow and should be clarified?
— What should be corrected?
In order to simplify annotations, the pdf file allows adding yellow sticker notes in
Adobe Reader. Alternatively, you can provide feedback on www.motionmountain.net/
wiki. Help on the specific points listed on the www.motionmountain.net/help.html web
page would be particularly welcome. All feedback will be used to improve the next edition. On behalf of all readers, thank you in advance for your input. For a particularly
useful contribution you will be mentioned – if you want – in the acknowledgements,
receive a reward, or both.
Your donation to the charitable, tax-exempt non-profit organisation that produces,
translates and publishes this book series is welcome! For details, see the web page www.
motionmountain.net/donation.html. If you want, your name will be included in the
sponsor list. Thank you in advance for your help, on behalf of all readers across the world.
A paper edition of this book, printed on demand and delivered by mail to any address, can be ordered at www.lulu.com/spotlight/motionmountain. But above all, enjoy
the reading!
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
Contents
16 1 From millennium physics to unification
Against a final theory 19 • What went wrong in the past 20 • How to find the final
theory of motion 21
24 2Physics in limit statements
24 Simplifying physics as much as possible
Everyday, or Galilean, physics in one statement 24 • Special relativity in one statement 25 • Quantum theory in one statement 26 • Thermodynamics in one statement 27 • General relativity in one statement 28 • Deducing general relativity 29
• Deducing universal gravitation 32 • The size of physical systems in general relativity 32 • A mechanical analogy for the maximum force 33
33 Planck limits for all physical observables
Physics, mathematics and simplicity 35 • Limits to space, time and size 35 • Mass
and energy limits 36 • Virtual particles – a new definition 37 • Curiosities and fun
challenges about Planck limits 37
41 Cosmological limits for all physical observables
Size and energy dependence 42 • Angular momentum and action 42 • Speed 43
• Force, power and luminosity 43 • The strange charm of the entropy bound 44
• Curiosities and fun challenges about system-dependent limits to observables 45
• Cosmology in one statement 47 • The cosmological limits to observables 47
• Limits to measurement precision and their challenge to thought 48 • No real
numbers 48 • Vacuum and mass: two sides of the same coin 49 • Measurement
precision and the existence of sets 49
50 Summary on limits in nature
52 3 General relativity versus quantum theory
The contradictions 53 • The origin of the contradictions 54 • The domain of contradictions: Planck scales 55 • Resolving the contradictions 57 • The origin of
points 57 • Summary on the clash between the two theories 58
59 4 Does mat ter differ from vacuum?
Farewell to instants of time 59 • Farewell to points in space 61 • The generalized
indeterminacy principle 63 • Farewell to space-time continuity 63 • Farewell
to dimensionality 66 • Farewell to the space-time manifold 66 • Farewell to observables, symmetries and measurements 67 • Can space-time be a lattice? 68 •
A glimpse of quantum geometry 69 • Farewell to point particles 70 • Farewell
to particle properties 71 • A mass limit for elementary particles 72 • Farewell to
massive particles – and to massless vacuum 73 • Matter and vacuum are indistinguishable 75 • Curiosities and fun challenges on Planck scales 76 • Common
constituents 80 • Experimental predictions 81 • Summary on particles and
vacuum 82
84 5 What is the difference between the universe and nothing?
Cosmological scales 84 • Maximum time 85 • Does the universe have a definite
age? 85 • How precise can age measurements be? 86 • Does time exist? 87
• What is the error in the measurement of the age of the universe? 88 • Maximum length 92 • Is the universe really a big place? 92 • The boundary of space
– is the sky a surface? 94 • Does the universe have initial conditions? 94 • Does
the universe contain particles and stars? 95 • Does the universe contain masses
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
contents 11
and objects? 96 • Do symmetries exist in nature? 97 • Does the universe have a
boundary? 98 • Is the universe a set? – Again 99 • Curiosities and fun challenges
about the universe 100 • Hilbert’s sixth problem settled 102 • The perfect
physics book 102 • Does the universe make sense? 103 • Abandoning sets and
discreteness eliminates contradictions 104 • Extremal scales and open questions
in physics 104 • Is extremal identity a principle of nature? 105 • Summary on the
universe 106 • A physical aphorism 107
108 6 The shape of points – extension in nature
109 The size and shape of elementary particles
Do boxes exist? 109 • Can the Greeks help? – The limitations of knives 109 • Are
cross sections finite? 110 • Can we take a photograph of a point? 111 • What is
the shape of an electron? 112 • Is the shape of an electron fixed? 113 • Summary
of the first argument for extension 114
114 The shape of points in vacuum
Measuring the void 116 • What is the maximum number of particles that fit inside
a piece of vacuum? 116 • Summary of the second argument for extension 116
117 The large, the small and their connection
Is small large? 117 • Unification and total symmetry 118 • Summary of the third
argument for extension 119
120 Does nature have parts?
Does the universe contain anything? 122 • An amoeba 122 • Summary of the
fourth argument for extension 123
123 The entropy of black holes
Summary of the fifth argument for extension 125
125 Exchanging space points or particles at Planck scales
Summary of the sixth argument for extension 126
126 The meaning of spin
Summary of the seventh argument for extension 128
128 Curiosities and fun challenges about extension
Gender preferences in physics 129
130 Checks of extension
Current research based on extended constituents 131 • Superstrings – extension
and a web of dualities 132 • Why superstrings and supermembranes are so appealing 132 • Why the mathematics of strings is so difficult 133 • Testing strings:
couplings and masses 134 • The status of the string conjecture 134 • Summary
on extension in nature 135
138 7 The basis of the strand model
Requirements for a final theory 138 • Introducing strands 140 • From strands to
modern physics 142 • Vacuum 146 • Observables and limits 147 • Particles and
fields 148 • Curiosities and fun challenges about strands 149 • Do strands unify?
– The millennium list of open issues 150 • Are strands final? – On generalizations
and modifications 152 • Why strands? – Simplicity 154 • Why strands? – The
fundamental circularity of physics 155 • Funnels – an equivalent alternative to
strands 158 • Summary on the fundamental principle of the strand model – and
on continuity 158
160 8 Quantum theory of matter deduced from strands
Strands, vacuum and particles 160 • The belt trick, rotation and spin 1/2 162 • An
aside: the belt trick saves lives 165 • Fermions, spin and statistics 166 • Bosons,
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
12 contents
spin and statistics 167 • Tangle functions: blurred tangles 168 • Details on fluctuations and averages 170 • Tangle functions are wave functions 170 • Deducing the
Schrödinger equation from tangles 175 • Mass from tangles 178 • Potentials 178 •
Quantum interference from tangles 179 • Deducing the Pauli equation from tangles 180 • Rotating arrows and path integrals 182 • Measurements and wave function collapse 182 • Many-particle states and entanglement 184 • Mixed states 187 •
The dimensionality of space-time 187 • Operators and the Heisenberg picture 188
• Hidden variables and the Kochen–Specker theorem 189 • Lagrangians and the
principle of least action 189 • Special relativity: the vacuum 191 • Special relativity: the invariant limit speed 191 • Dirac’s equation deduced from tangles 193 •
Visualizing spinors and Dirac’s equation using tangles 196 • Quantum mechanics
vs. quantum field theory 198 • A flashback: settling three paradoxes of Galilean
physics 199 • Fun challenges about quantum theory 199 • Summary on quantum theory of matter: millennium issues and experimental predictions 201
203 9 Gauge interactions deduced from strands
Interactions and phase change 203 • Tail deformations versus core deformations 204
207 Electrodynamics and the first Reidemeister move
Strands and the twist, the first Reidemeister move 207 • Can photons decay or
disappear? 208 • Electric charge 209 • Challenge: What knot invariant is electric
charge? 210 • Electric and magnetic fields and potentials 210 • The Lagrangian of
the electromagnetic field 212 • U(1) gauge invariance induced by twists 212 • U(1)
gauge interactions induced by twists 214 • The Lagrangian of QED 215 • Feynman
diagrams and renormalization 215 • Maxwell’s equations 218 • Curiosities and fun
challenges about QED 220 • Summary on QED and experimental predictions 221
223 The weak nuclear interaction and the second Reidemeister move
Strands, pokes and SU(2) 224 • Weak charge and parity violation 225 • Weak
bosons 227 • The Lagrangian of the unbroken SU(2) gauge interaction 228 •
SU(2) breaking 228 • The electroweak Lagrangian 230 • The weak Feynman diagrams 231 • Fun challenges and curiosities about the weak interaction 231 • Summary on the weak interaction and experimental predictions 233
235 The strong nuclear interaction and the third Reidemeister move
Strands and the slide, the third Reidemeister move 235 • From slides to SU(3) 236
• Open challenge: Find a better argument for the gluon tangle 240 • The gluon
Lagrangian 240 • Colour charge 241 • Properties of the strong interaction 243 •
The Lagrangian of QCD 243 • Renormalization of the strong interaction 243 • Curiosities and fun challenges about SU(3) 244 • Summary on the strong interaction
and experimental predictions 244
246 Summary on millennium issues: gauge interactions
Prediction about the number of interactions 246 • Unification of interactions 246
• Predictions about grand unification and supersymmetry 247 • No new observable gravity effects in particle physics 247 • The status of our quest 248
249 10 General relativity deduced from strands
Flat space, special relativity and its limitations 249 • Classical gravitation 250
• Deducing universal gravitation from black hole properties 251 • Summary on
universal gravitation from strands 252 • Curved space 253 • Horizons and black
holes 254 • Is there something behind a horizon? 255 • Energy of black hole horizons 255 • The nature of black holes 256 • Entropy of horizons 256 • Temperature,
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
contents 13
radiation and evaporation of black holes 258 • Black hole limits 259 • Curvature
around black holes 260 • The field equations of general relativity 261 • Equations
from no equation 262 • The Hilbert action of general relativity 263 • Space-time
foam 263 • Gravitons and gravitational waves 263 • Open challenge: Improve the
argument for the graviton tangle 264 • Other defects in vacuum 264 • Torsion,
curiosities and challenges about general relativity 265 • Predictions of the strand
model about general relativity 268
269 Cosmology
The finiteness of the universe 269 • The big bang 271 • The cosmological
constant 272 • The value of the matter density 273 • Open challenge: Are the
conventional energy and matter densities correct? 274 • The topology of the universe 274 • Predictions of the strand model about cosmology 274 • Summary on
millennium issues: relativity and cosmology 275
277 11 The particle spectrum deduced from strands
Particles and quantum numbers from tangles 277
279 Particles made of one strand
Unknotted curves 279 • Gauge bosons 280 • Complicated knots 281 • Closed
tangles: knots 282 • Summary on tangles made of one strand 282
282 Particles made of two strands
Quarks 284 • Quark generations 286 • The graviton 287 • Glueballs 287 • The
mass gap problem and the Clay Mathematics Institute 288 • A puzzle 289 • Summary on two-stranded tangles 289
289 Particles made of three strands
Leptons 290 • Open challenge: Find better arguments for the lepton tangles 292 •
The Higgs boson – in 2009 292 • The Higgs boson – summer 2012 update 294 •
Quark-antiquark mesons 295 • Meson form factors 297 • Meson masses, excited
mesons and quark confinement 299 • CP violation in mesons 300 • Other threestranded tangles and glueballs 302 • Summary on three-stranded tangles 302
302 Tangles of four and more strands
Baryons 303 • Tetraquarks and exotic mesons 303 • Other tangles made of four
or more strands 305 • Summary on tangles made of four or more strands 307
308 Fun challenges and curiosities about particle tangles
Motion through the vacuum – and the speed of light 309
313 Summary on millennium issues and predictions about particles
Predictions about dark matter and the LHC 314
315 12Part icle propert ies deduced from strands
315 The masses of the elementary particles
General properties of particle mass values 316 • Boson mass ratios and the weak
mixing angle 316 • Quark mass ratios 318 • Lepton mass ratios 320 • Mass ratios across particle families 321 • Predictions about absolute mass values and the
mass hierarchy 322 • Open issue: calculate masses ab initio 324 • Summary on
elementary particle masses and millennium issues 325
326 Mixing angles
Quark mixing 326 • A challenge 328 • CP-violation in quarks 328 • Neutrino
mixing 328 • CP-violation in neutrinos 329 • Open challenge: Calculate mixing
angles and phases ab initio 330 • Summary on mixing angles and the millennium
list 330
331 Coupling constants and unification
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
14 contents
Strands imply unification 333 • General expectations about coupling constants 333
• First hint: charge quantization and topological writhe 334 • Second hint: the
energy dependence of physical quantities 335 • Third hint: the running of the coupling constants at low energy 335 • Fourth hint: predictions at low energy, independent of particle content 336 • The running of the coupling constants near Planck
energy 337 • On estimating the fine structure constant from knot shapes 337 •
Fifth hint: 3d-writhe 338 • Sixth hint: torsion 339 • Seventh hint: linking number 339 • Eighth hint: estimating the fine structure constant from phase effects 339
• Ninth hint: a calculation approach for two coupling constants 340 • Open challenge: Calculate coupling constants ab initio 340 • Summary on coupling constants and millennium issues 341
342 The final summary on the millennium issues
343 Experimental predictions of the strand model
346 13 The top of Motion Mountain
346 Our path to the top
Everyday life: the rule of infinity 346 • Relativity and quantum theory: the absence
of infinity 347 • Unification: the absence of finitude 349
350 New sights
The beauty of strands 350 • Can the strand model be generalized? 351 • What
is nature? 352 • Quantum theory and the nature of matter 353 • Cosmology 353
• Musings about unification and strands 354 • The elimination of induction 358
• What is still hidden? 359
359 A return path: je rêve, donc je suis
361 What is motion?
363 Postface
364 a Knot geometry
367 Challenge hints and solutions
371 Bibliography
392 Credits
Acknowledgments 392 • Film credits 392 • Image credits 393
394 Name index
400 Subject index
Motion Mountain – The Adventure of Physics pdf file available free of charge at www.motionmountain.net Copyright © Christoph Schiller June 1990–December 2012
The Strand Model –
A Speculation on
Unification
Where, through the combination of
quantum mechanics and general relativity,
the top of Motion Mountain is reached,
and it is discovered
that vacuum is indistinguishable from matter,
that there is little difference between the large and the small,
that nature can be described by strands,
that particles can be modelled as tangles,
that interactions appear naturally,
and that a complete description of motion is possible.