This very well written and fascinating article explores the problem of time in physics—-specifically, the question of whether time and its passing are ultimately “real” and in what sense they are real, which turns out actually be a metaphysical question (a question about the nature of existence that encompasses physical science but is larger than science alone) , or at least one underwritten by metaphysical assumptions and with metaphysical implications. When Physicists, reflecting on the deep nature of time rather than just its function as a physical-mathematical dynamic, sometimes confront this issue, it becomes metaphysically problematic.
The big questions physicists ask along these lines ask are whether 1) the question and concept even make sense (can we even measure or quantify something as we malleable and tenuous as time seems to be?) and 2) there are there discernible physical ways to determine what it is and/or what it does. The article states:
“When it comes to the question of existence, physics is very simple and straightforward about what it considers to be a satisfactory answer.
* Can you measure it?
* Can you quantify it?
* Can you define it in a mathematically self-consistent way?
* Is it, itself, an observable quantity, and do other observables depend on it in an inextricable way?”
With this definition of “existence” (reality) as a standard, the article then examines some well-known developments and debates in the history of theoretical physics that have turned on the reality and nature of time. It looks at things like Einstein’s special/general theories of relativity, which relativized time in terms of forces like relative position, momentum, and mass, and it illustrates how this kind of relativity still affirms the basic (albeit now transformed) reality of time. It also addresses the relevance of universal entropy via the 2nd law of thermodynamics (the inexorable decrease of energy and order in all physical systems—including the universe at large) and how this phenomenon is popularly thought to be the cause of time’s asymmetry (why it travels in only one direction—from past to future— instead of the other way or in neither direction at all). This has raised the question of whether time and its mysterious asymmetry is the cause of entropy, or whether entropy caused time as an emergent property. The article concludes that Despite the complex and problematic nature of this debate however, the above definition of existence- reality is satisfied and time remains fundamentally “real”.
While I find this perspective from current physics on the nature and reality of time to be very illuminating, it also leaves me wondering about even deeper questions regarding the nature and reality of physics and of science itself. Scientific Realism is the school of thought that views scientific knowledge of reality as a mirror image of reality itself. Analogous in this way to Biblical Literalism (which claims that Biblical descriptions of reality are true literally), Scientific Realism claims that scientific concepts about reality are true literally. “Antirealism” regarding scientific knowledge, in contradistinction, holds that scientific concepts —like all others, in religion, literature, art,metaphysics etc.—are merely metaphors, symbols or models of the actual reality they stand-for or signify. Scientific descriptions of reality are like literature , history, religion, art, and myth in trying to describe the infinite richness and depth of experience and reality with ideas, concepts and images whose objective veracity is constrained by the limitations of the very ideas, images, and concepts we use to describe them
The realist/ antirealist debate re:science , physics, and time in particular, was (largely)central to the famous debate between Einstein and philosopher Henry Bergson in the second decade of the twentieth century. Einstein (whose “block universe” conception of time held that all times exist simultaneously in an unchanging eternal mathematical symmetry and the asymmetric time of ordinary experience is just a result of flawed human perception) was, ironically,a scientific realist who argued that this physical description of time is literally true. Bergson argued that time just describes a dynamic vital experience whose nature depends on the experiential and conceptual context from which it arises
While I’m not completely averse to the idea of scientific realism myself, I tend to (if I understand his position,that is) concur with the kind of antirealism advocated by Bergson: Scientific conceptions of time —or any other phenomenon— are ‘real’ to the extent that they give us clarity regarding the aspects of reality for which scientific knowledge and the scientific method (as defined in the second paragraph of this discussion above) is suitable for describing . This circular conception of knowledge is true of all other depictions of reality as well. However when science attempts to exceed this epistemic limit and claim that its knowledge is LITERALLY real, then it is no longer making scientific claims about physical reality , but is instead making METAphysical claims about objectively ‘pure’ reality-in-itself (which —ideally—falls within the purview philosophy, not science). So the scientific investigation of whether, or to what extent, time may or may not be real, should be appreciated as an investigation into the nature of SCIENTIFIC reality, rather than “reality’ in itself….perhaps St. Augustine said it best: “What is time then? If nobody asks me, I know; but if I were desirous to explain it to one that should ask me, plainly I do not know.”
