Prologue
Don’t Be Afraid
“I think I can safely say”: See R. P. Feynman (1965), The Character of Physical Law, MIT Press, 123.
Chapter 2
The Courageous Formulation
Austere Quantum Mechanics
“Shut up and calculate”: See N. D. Mermin (2004), “Could Feynman Have Said This?” Physics Today 57, 5, 10.
Chapter 3
Why Would Anybody Think This?
How Quantum Mechanics Came to Be
“six impossible things”: L. Carroll (1872), Through the Looking Glass and What Alice Found There, Dover, 47.
“Sweet is by convention”: Quoted in H. C. Von Baeyer (2003), Information: The New Language of Science, Weidenfeld & Nicolson, 12.
“very revolutionary”: Quoted in R. P. Crease and A. S. Goldhaber (2014), The Quantum Moment: How Planck, Bohr, Einstein, and Heisenberg Taught Us to Love Uncertainty, W. W. Norton & Company, 38.
“There appears to me one grave difficulty”: Quoted in H. Kragh (2012), “Rutherford, Radioactivity, and the Atomic Nucleus,” https://arxiv.org/abs/1202.0954.
“had written a crazy paper”: Quoted in A. Pais (1991), Niels Bohr’s Times, in Physics, Philosophy, and Polity, Clarendon Press, 278.
“A veritable sorcerer’s calculation”: Quoted in J. Bernstein (2011), “A Quantum Story,” The Institute Letter, Institute for Advanced Study, Princeton.
“I don’t like it”: Quoted in J. Gribbin (1984), In Search of Schrödinger’s Cat: Quantum Physics and Reality, Bantam Books, v.
Chapter 4
What Cannot Be Known, Because It Does Not Exist
Uncertainty and Complementarity
For more on the double-slit experiment, see A. Ananthaswamy (2018), Through Two Doors at Once: The Elegant Experiment That Captures the Enigma of Our Quantum Reality, Dutton.
Chapter 5
Entangled Up in Blue
Wave Functions of Many Parts
A. Einstein, B. Podolsky, and N. Rosen (1935), “Can Quantum-Mechanical Description of Reality Be Considered Complete?” Physical Review 47, 777.
For general insight into Bell’s theorem and its relationship to EPR and Bohmian mechanics, see T. Maudlin (2014), “What Bell Did,” Journal of Physics A 47, 424010.
“secular press”: Quoted in W. Isaacson (2007), Einstein: His Life and Universe, Simon & Schuster, 450.
D. Rauch et al. (2018), “Cosmic Bell Test Using Random Measurement Settings from High-Redshift Quasars,” Physical Review Letters 121, 080403.
Chapter 6
Splitting the Universe
Decoherence and Parallel Worlds
A good biography of Hugh Everett is P. Byrne (2010), The Many Worlds of Hugh Everett III: Multiple Universes, Mutual Assured Destruction, and the Meltdown of a Nuclear Family, Oxford University Press. Quotes in this chapter are largely from this book and A. Becker (2018), What Is Real?, Basic Books.
Everett’s original paper (long and short versions) and various commentaries can be found in B. S. DeWitt and N. Graham (1973), The Many Worlds Interpretation of Quantum Mechanics, Princeton University Press.
“Nothing has done more to convince me”: Quoted in A. Becker (2018), What Is Real?, Basic Books, 127.
H. D. Zeh (1970), “On the Interpretation of Measurements in Quantum Theory,” Foundations of Physics 1, 69.
“The Copenhagen Interpretation is hopelessly incomplete”: Quoted in P. Byrne (2010), 141.
“Split?”: Quoted in P. Byrne (2010), 139.
“Lest the discussion of my paper die”: Quoted in P. Byrne (2010), 171.
“doomed from the beginning”: Quoted in A. Becker (2018), 136.
“I can’t resist asking”: Quoted in P. Byrne (2010), 176.
“I realize that there is a certain value”: M. O. Everett (2007), Things the Grandchildren Should Know, Little, Brown, 235.
Chapter 7
Order and Randomness
Where Probability Comes From
“Why do people say”: Quoted in G.E.M. Anscombe (1959), An Introduction to Wittgenstein’s Tractatus, Hutchinson University Library, 151.
“fatness measure”: D. Z. Albert (2015), After Physics, Harvard University Press, 169.
W. H. Zurek (2005), “Probabilities from Entanglement, Born’s Rule from Envariance,” Physical Review A 71, 052105.
C. T. Sebens and S. M. Carroll (2016), “Self-Locating Uncertainty and the Origin of Probability in Everettian Quantum Mechanics,” British Journal for the Philosophy of Science 69, 25.
D. Deutsch (1999), “Quantum Theory of Probability and Decisions,” Proceedings of the Royal Society of London A455, 3129.
For a comprehensive review of the decision-theoretic approach to the Born rule, see D. Wallace (2012), The Emergent Multiverse.
Does This Ontological Commitment Make Me Look Fat?
A Socratic Dialogue on Quantum Puzzles
“mistaken and even a vicious”: K. Popper (1967), “Quantum Mechanics Without the Observer,” in M. Bunge (ed.), Quantum Theory and Reality. Studies in the Foundations Methodology and Philosophy of Science, vol. 2, Springer, 12.
“a completely objective discussion”: K. Popper (1982), Quantum Theory and the Schism in Physics, Routledge, 89.
For more on entropy and the arrow of time, see S. M. Carroll (2010), From Eternity to Here: The Quest for the Ultimate Theory of Time, Dutton.
“Asking how many worlds”: D. Wallace (2012), The Emergent Multiverse, 102.
“Despite the unrivaled empirical success”: D. Deutsch (1996), “Comment on Lock-wood,” British Journal for the Philosophy of Science 47, 222.
Chapter 9
Other Ways
Alternatives to Many-Worlds
“clearly being assigned”: Quoted in A. Becker (2018), What Is Real?, Basic Books, 213.
“If we cannot disprove Bohm”: Quoted in A. Becker (2018), 90.
“the paper is completely senseless”: Quoted in A. Becker (2018), 199.
“Everett phone”: J. Polchinski (1991), “Weinberg’s Nonlinear Quantum Mechanics and the Einstein-Podolsky-Rosen Paradox,” Physical Review Letters 66, 397.
For more on hidden-variable and dynamical-collapse models, see T. Maudlin (2019), Philosophy of Physics: Quantum Theory, Princeton.
R. Penrose (1989), The Emperor’s New Mind: Concerning Computers, Minds, and the Laws of Physics, Oxford.
“the Einstein-Podolsky-Rosen paradox is resolved”: J. S. Bell (1966), “On the Problem of Hidden-Variables in Quantum Mechanics,” Reviews of Modern Physics 38, 447.
“a superfluous ideological superstructure,” and “artificial metaphysics”: Quoted in W. Myrvold (2003), “On Some Early Objections to Bohm’s Theory,” International Studies in the Philosophy of Science 17, 7.
H. C. Von Baeyer (2016), QBism: The Future of Quantum Physics, Harvard.
“There is indeed” and “QBism regards”: N. D. Mermin (2018), “Making Better Sense of Quantum Mechanics,” Reports on Progress in Physics 82, 012002.
C. A. Fuchs (2017), “On Participatory Realism,” in I. Durham and D. Rickles, eds., Information and Interaction, Springer.
“The Everett interpretation (insofar as it is philosophically acceptable)”: D. Wallace (2018), “On the Plurality of Quantum Theories: Quantum Theory as a Framework, and Its Implications for the Quantum Measurement Problem,” in S. French and J. Saatsi, eds., Scientific Realism and the Quantum, Oxford.
Chapter 10
The Human Side
Living and Thinking in a Quantum Universe
M. Tegmark (1998), “The Interpretation of Quantum Mechanics: Many Worlds or Many Words?” Fortschrift Physik 46, 855.
R. Nozick (1974), Anarchy, State, and Utopia, Basic Books, 41.
“All that quantum mechanics purports to provide”: E. P. Wigner (1961), “Remarks on the Mind-Body Problem,” in I. J. Good, The Scientist Speculates, Heinemann.
Chapter 11
Why Is There Space?
Emergence and Locality
I talk more about emergence (and the Core Theory) in S. M. Carroll (2016), The Big Picture: On the Origins of Life, Meaning, and the Universe Itself, Dutton.
“I think my father”: James Hartle (2016), personal communication.
Chapter 12
A World of Vibrations
Quantum Field Theory
“It is inconceivable that inanimate brute matter should”: I. Newton (2004), Newton: Philosophical Writings, ed. A. Janiak, Cambridge, 136.
P.C.W. Davies (1984), “Particles Do Not Exist,” in B. S. DeWitt, ed., Quantum Theory of Gravity: Essays in Honor of the 60th Birthday of Bryce DeWitt, Adam Hilger.
Breathing in Empty Space
Finding Gravity within Quantum Mechanics
For more on the implications and limitations of locality, see G. Musser (2015), Spooky Action at a Distance: The Phenomenon That Reimagines Space and Time—and What It Means for Black Holes, the Big Bang, and Theories of Everything, Farrar, Straus and Giroux.
“I use more brain grease”: A. Einstein, quoted by Otto Stern (1962), interview with T. S. Kuhn, Niels Bohr Library & Archives, American Institute of Physics, https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4904.
“Perhaps the success of the Heisenberg method”: A. Einstein (1936), “Physics and Reality,” reprinted in A. Einstein (1956), Out of My Later Years, Citadel Press.
T. Jacobson (1995), “Thermodynamics of Space-Time: The Einstein Equation of State,” Physical Review Letters 75, 1260.
T. Padmanabhan (2010), “Thermodynamical Aspects of Gravity: New Insights,” Reports on Progress in Physics 73, 046901.
E. P. Verlinde (2011), “On the Origin of Gravity and the Laws of Newton,” Journal of High Energy Physics 1104, 29.
J. S. Cotler, G. R. Penington, and D. H. Ranard (2019), “Locality from the Spectrum,” Communications in Mathematical Physics, https://doi.org/10.1007/s00220-019-03376-w.
J. Maldacena and L. Susskind (2013), “Cool Horizons for Entangled Black Holes,” Fortschritte der Physik 61, 781.
C. Cao, S. M. Carroll, and S. Michalakis (2017), “Space from Hilbert Space: Recovering Geometry from Bulk Entanglement,” Physical Review D 95, 024031.
C. Cao and S. M. Carroll (2018), “Bulk Entanglement Gravity Without a Boundary: Towards Finding Einstein’s Equation in Hilbert Space,” Physical Review D 97, 086003.
T. Banks and W. Fischler (2001), “An Holographic Cosmology,” https://arxiv.org/abs/hep-th/0111142.
S. B. Giddings (2018), “Quantum-First Gravity,” Foundations of Physics 49, 177.
D. N. Page and W. K. Wootters (1983). “Evolution Without Evolution: Dynamics Described by Stationary Observables,” Physical Review D 27, 2885.
Beyond Space and Time
Holography, Black Holes, and the Limits of Locality
Holography, complementarity, and black hole information are discussed in L. Susskind (2008), The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, Back Bay Books.
A. Almheiri, D. Marolf, J. Polchinski, and J. Sully (2013), “Black Holes: Complementarity or Firewalls?” Journal of High Energy Physics 1302, 062.
J. Maldacena (1997), “The Large-N Limit of Superconformal Field Theories and Supergravity,” International Journal of Theoretical Physics 38, 1113.
S. Ryu and T. Takayanagi (2006), “Holographic Derivation of Entanglement Entropy from AdS/CFT,” Physical Review Letters 96, 181602.
B. Swingle (2009), “Entanglement Renormalization and Holography,” Physical Review D 86, 065007.
M. Van Raamsdonk (2010), “Building Up Spacetime with Quantum Entanglement,” General Relativity and Gravitation 42, 2323.
Epilogue
Everything Is Quantum
“A wonder of this kind”: A. Einstein (1949), Autobiographical Notes, Open Court Publishing, 9.
Appendix
The Story of Virtual Particles
For more on Feynman diagrams, see R. P. Feynman (1985), QED: The Strange Theory of Light and Matter, Princeton University Press.