What is time? This book explores the hypothesis that time is discrete rather than continuous. Time is an enigma, so we should expect some metaphysics and philosophy to creep into the discussion. Our inclination is to avoid those disciplines as much as possible, so let us deal with them right now. Metaphysics and philosophy deal with statements and conjectures that cannot be empirically validated. In those disciplines there are constant references to absolutes such as existence, good and bad, and suchlike without further qualification, as if everyone accepted them as meaningful concepts. Absolutes are the key things we wish to avoid. For the record, we define an absolute statement as one that is considered to be true regardless of any caveats or criteria, i.e., context-free. In contrast, a contextual statement has a truth value that is meaningful only relative to its particular context. The idea that physical truth can be contextual is an unfamiliar and uncomfortable one to physicists conditioned to believe that the laws of physics transcend the context of observation because they can be empirically validated. In fact, that is a circular line of reasoning. Every experiment is defined by its own context and experimentalists have to work hard to create that context: the search for the Higgs particle at the Large Hadron Collider did not happen overnight.
What is time? This book explores the hypothesis that time is discrete rather than continuous. Time is an enigma, so we should expect some metaphysics and philosophy to creep into the discussion. Our inclination is to avoid those disciplines as much as possible, so let us deal with them right now. Metaphysics and philosophy deal with statements and conjectures that cannot be empirically validated. In those disciplines there are constant references to absolutes such as existence, good and bad, and suchlike without further qualification, as if everyone accepted them as meaningful concepts. Absolutes are the key things we wish to avoid. For the record, we define an absolute statement as one that is considered to be true regardless of any caveats or criteria, i.e., context-free. In contrast, a contextual statement has a truth value that is meaningful only relative to its particular context. The idea that physical truth can be contextual is an unfamiliar and uncomfortable one to physicists conditioned to believe that the laws of physics transcend the context of observation because they can be empirically validated. In fact, that is a circular line of reasoning. Every experiment is defined by its own context and experimentalists have to work hard to create that context: the search for the Higgs particle at the Large Hadron Collider did not happen overnight.
ENERAL philosophy claims to be the critical subject which lays down for all of us what we may be allowed to think, and yet it has played no part whatever in the great revolutions of human thought of the present century-those connected with relativity and the quantum theory. It might have been expected that the scientists would have been constantly consulting the philosophers as to the legitimacy of their various speculations, but nothing of the kind has happened. Since no one can dispense with some sort of metaphysic, each scientist has made one for himself, and no doubt they contain many crudities, but it would seem that a deep interest in metaphysic is a disadvantage rather than an advantage to the physicist-at least I have the impression that those of my friends who are most inclined to speculate on the ultimate things appear to be the ones whose scientific work is most hampered by doing so. Now I propose to risk a similar indiscretion. I want to embody in it the practical philosophy of a physicist, and I do not mean it as an attack on the pure philosophers, who are very reasonable people, only chargeable with the minor offence of not having made me want to read their books! I had better begin by stating shortly the ideas I intend to discuss. There is a notable contrast between the way we think about things and the way we think we ought to think about them.
Scientists have been debating the meaning of quantum mechanics for over a century. This book for graduate students and researchers gets to the root of the problem; the contextual nature of empirical truth, the laws of observation and how these impact on our understanding of quantum physics. Bridging the gap between non-relativistic quantum mechanics and quantum field theory, this novel approach to quantum mechanics extends the standard formalism to cover the observer and their apparatus. The author demystifies some of the aspects of quantum mechanics that have traditionally been regarded as extraordinary, such as wave-particle duality and quantum superposition, by emphasizing the scientific principles rather than the mathematical modelling involved. Including key experiments and worked examples throughout to encourage the reader to focus on empirically sound concepts, this book avoids metaphysical speculation and also alerts the reader to the use of computer algebra to explore quantum experiments of virtually limitless complexity.
There are several (general) philosophy of physics textbooks on the market.1 An
obvious question to ask at the outset then is: Why another one? In his “Some
Philosophical Aspects of Particle Physics”, Michael Redhead bemoans the common practice of philosophers of science of dealing with examples “which are no
longer of current research interest in science” ((1980), p. 279). This practice is
still common even among many philosophers of physics, and, for the most part,
the available textbooks continue to engage in this practice. Generally, one finds a
little spacetime, a little statistical mechanics, and a little quantum theory. Now,
these are of course the ‘pillars’ of modern physics, so it is what we should expect
to be covered in any textbook on the philosophy of physics worth its salt (and,
indeed, they are well represented in this book). However, the issues that are
dealt with are usually very old fashioned and very limited in scope: ‘spacetime’
means ‘the twins paradox’ (and possibly conventionalism); ‘statistical mechanics’
means ‘time asymmetry’; and ‘quantum theory’ means ‘the measurement problem’. Redhead is surely right that this leads physicists to “regard philosophy of
science as somewhat irrelevant”. Rightly so, too, if this were in fact representative of much of what actually goes on in philosophy of physics. However, the
state of play as represented in philosophy of physics and (some) philosophy of
science journals shows a very different level of engagement, with philosophers
of physics investigating the frontiers of scientific research. This disparity (or the
impression of such) is the raison d’eˆtre for the book you are now reading. The result is an introductory textbook covering those portions of philosophy of physics
research that other textbooks fail to cover, or cover only very briefly or very
simplistically. The three pillars of modern physics-relativity, quantum theory
and statistical mechanics-are still represented, then, but from a more advanced
and contemporary perspective.
Scientists have been debating the meaning of quantum mechanics for more than a century. This book for graduate students and researchers gets to the root of the problem: how the contextual nature of empirical truth and the laws of observation impact on our understanding of quantum physics. Bridging the gap between non-relativistic quantum mechanics and quantum field theory, this novel approach to quantum mechanics extends the standard formalism to cover the observer and their apparatus. The author demystifies some of the aspects of quantum mechanics that have traditionally been regarded as extraordinary, such as wave-particle duality and quantum superposition, emphasizing the scientific principles rather than the mathematical modelling. Including key experiments and worked examples throughout, the author encourages the reader to focus on empirically sound concepts and avoid metaphysical speculation. Originally released in 2017, this title has been reissued as an Open Access publication on Cambridge Core.
Time – what it is and its nature – has from the beginning held mysteries for layman, philosopher, and physicist alike. Periodic phenomena from motions of heavenly bodies and pendulums to quantal atomic clocks provide the means to measure time intervals, and Newton’s absolute time is a background flow against which classical and non-relativistic quantum physics is played out. While internally consistent, these two fields of physics are incompatible with the requirement of treating space and time on an equal footing. Quantum field theories provide the answer, as both treated as parameters, physics residing instead in the states and operators. But even in classical physics and quantum mechanics, time-independent descriptions provide an alternative to an explicitly time-dependent one. These, including a general method of approach called invariant imbedding, are discussed as alternative representations of an underlying reality that is the concern of physics.
Reviewed by: Untying the Gordian Knot: Process, Reality, and Context by Timothy Eastman Dan Dombrowski EASTMAN, Timothy. Untying the Gordian Knot: Process, Reality, and Context. New York: Lexington Books, 2020. 344 pp. Cloth, $120.00; eBook, $45.00 The title of this book reminds one of David Ray Griffin’s 1998 study, Unsnarling the World Knot: Consciousness, Freedom, and the Mind-Body Problem. Both books rely on process philosophy to respond to seemingly insoluble problems (called the “world-knot” by Arthur Schopenhauer) created in the wake of early modern dualism, which led to late modern mechanism once the ghost in the machine was exorcised. One significant difference is that Eastman is a prominent physicist who tries to untie the knots created by deterministic views of the natural world, in contrast to Griffin’s more philosophical and theological approach. The knots in question can be untied only by thinking creatively in new ways, Eastman thinks. Eastman calls his approach the “Logoi framework,” which rejects Niels Bohr’s Copenhagen Interpretation and the assumption that indeterminacy effects are mostly assigned to epistemic limitations while fundamental reality is set aside. Eastman also spends a good deal of time challenging the assumption that the real is nothing but the actual in that reality includes, he thinks, both actualizations and possibilities. That is, Eastman argues against mechanism, determinism, and “actualism.” This last sort of opposition, in turn, leads Eastman to defend not merely Boolean logic but also a non-Boolean order of potentials. Eastman criticizes various “theories of everything” and conceptions of “multiverses” that ironically continue nominalism and metaphysically parsimonious, reductionist, deflationary ontologies. In some ways he is continuing where Henri Bergson left off in his debates with Albert Einstein in 1922. By focusing exclusively on objective measurement, Bergson thought that Einstein had neglected important contextual issues. In contrast to Einstein’s deterministic outlook, Bergson (along with Eastman) argues that the future is open and indeterminate. There is no warrant for “scientism” to overrule experience. That is, it is a mistake, Eastman thinks, to hold that there are preexistent laws that result in strict entailments from causes to effects and to hold that effects are, for all practical purposes, contained in their causes. Physicists themselves undermine the metaphysical claim that the real is merely the actual in that their research presupposes as well the region of the potential; this “hardcore actualism” is bad physics by ignoring [End Page 144] altogether the reality of potentiae. The “scientism” that Eastman opposes is thus problematic because of its actualism, its assumption that reality is fully captured by quantitative laws of entailment, its reliance on dyadic relations alone (in contrast to the Peircian triadic scheme favored by Eastman), its commitment to the causal closure of the physical, and its mechanism. Eastman’s own positive process alternative involves the claim that all reality is characterized by res extensa, res qualia, and potentiae. This positive alternative makes us realize that classical mechanics is not a neutral designator in that it tends to carry with it metaphysical assumptions, including a type of substantialism in tension with a processual approach. Many or most practicing scientists do not pay much attention to the fact that nominalism and realism imply metaphysical claims, as do actualism and determinism. Although Werner Heisenberg argued several decades ago for the importance of potentiae, he was only minimally influential in the community of physicists, who unwittingly had metaphysical commitments that they were not willing to abandon. Although Eastman’s own approach is encyclopedic in the sense that he seemingly cites every author who deals with the topics he is interested in, his own distinctive approach is clear in the midst of the citations. Most notably, Eastman takes Alfred North Whitehead’s diachronic approach very seriously in his own interpretation of the results that physicists have offered. One of the reasons for Eastman’s skepticism regarding what are often called “possible worlds” is that defenders of these often offer nothing other than acutalized possibles, rather than ontic possibiliae. Eastman’s own area of expertise is plasma physics, which puts him in an enviable position to defend the common process argument against the concept of absolute nothingness. There is no such thing as...