I haven’t had much of a chance to get things done Monday; that day was rougher and more hectic than I thought it would be. But I did get some more physics reading done.
That piece of physics, or rather philosophy of physics, relates to yesterday’s post about how people’s conceptions of reality can affect their moral beliefs. Consider the block time interpretation of temporality in relativity physics. Here’s basically how it works. Intuitively, people tend to think of time as a continuously becoming present that is calcified into a past as it progresses into a yet-to-be-determined future. The present is all that really exists; the future isn’t here yet and the past is gone.
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| Whenever relativity theory is discussed, Albert Einstein is the most obvious choice for a picture. But I went with Arthur Eddington because he was so important in advocating special and general relativity theory to the world. Plus, David Tennant played him in the movie. |
This is all reduced to bollocks in the context of special relativity. When position in time depends on relative motion of one reference frame compared to another, along with position in space, events that are simultaneous in one frame of reference occur at different times in another. A moment in the future of one person can occur in the past of another. Event E occurs in the past of person A, the future of person B, and the present of person C, solely because of how A, B, and C are moving relative to each other and the event E. In order to map these relations properly, we have to represent time mathematically in the same way as space. All points in the dimension of time, all events, all planes of relative simultaneity, can be laid out as a spatial dimension. There is no distinguishing an absolute past from present from future. There is no now, no gone, and no not-yet. There are only the relative order of events and the catalogue of possible relations among those events. The events themselves all exist in their particular order, and frames of references move through this order at varying paces relative to other frames of reference. The universe is a set, four-dimensional block where no divergence from any given path is possible. That’s the ontological element of this perspective.
I sometimes wonder why philosophers continue to think of the naturalistic fallacy as an unquestionable truth when this whole problem speaks to the complex relationship of our ontological and moral philosophies. Because this is just the modern version of the old problem of freedom and causal determinism. The problem used to be phrased in terms of clockwork determination of the mechanisms of the universe. Given that all movements have a cause, there are no uncaused movements. A free action must have no cause but the action itself. Given that a person can only be responsible for actions without external causes, the only free movements must be cause-less. But all movements have causes, therefore there are no free actions. So no one is truly morally responsible for their actions. Mark Chapman and John Lennon carry no reason for blame or praise; they simply move according to the causes that determine them.
The problem is, of course, more complicated and detailed in its philosophical history than this paragraph, as a problem will when it’s centuries old. But relativity theory’s block time concept changes where the determination of all movement lies. The old clockwork image discussed causation. The new block image discusses the structure of events in spacetime itself. But they amount to the same: all movement is pre-determined. Chapman and Lennon move through their paths in spacetime, divergence from those paths are impossible, and so praise and blame are equally illegitimately applied to both. Moral judgment itself is meaningless in a fully determined universe.
There have been many attempts to solve this problem. I myself don’t think it’s a real problem for several very complex reasons I don’t have time to go into right now, mostly my theories of what are the genuine implications of the fundamental laws of the universe being statistical and probabilistic in nature. But that’s beside the point.
The point is that the problem of freedom and determinism is an ontological issue with clear implications for moral reasoning. Whenever someone cavalierly whips out the naturalistic fallacy as a knock-down argument against someone linking ontological and moral domains of thinking, that person should consider the freedom-determinism problem and what it means for a conception of reality to be morally meaningful.
I'm not following your account of past, present and future in special relativity. The spacetime interval is invariant, and the sign of the interval determines whether the interval is timelike or spacelike. Causal relationships are only possible between events separated by timelike intervals. Thus each event has a past and future, defined by timelike separations, and an elsewhere defined by spacelike separations. The time order of events separated by spacelike intervals is not absolute, but this is of no physical significance as the two events can have no causal relationship with each other.
ReplyDeleteAt least, until someone invents faster than light travel, at which point all bets are off...
Hell, I knew I shouldn't have skipped over interval talk. I was mostly just aiming to reach the philosophical implications (determinism by existence of all events in spacetime v. determinism by causal necessity) and moved too fast.
DeleteThe truly radical movement in Einstein's relativity was the new concept of interval, that distance in space and distance in time aren't categorically different. Come to think of it, that's a much easier way to explain the basics of my approach to the implications of the block time concept outside straight philosophical ontology.
Leaving relativity aside for the moment, it may be interesting/fruitful to consider the Hamiltonian formulation of mechanics, which replaces the Newtonian formulation of evolution of a system in time from given initial conditions with the solution of the global system given its boundary conditions. This has the advantage that, unlike relativity, it straightforwardly carries over into quantum mechanics, in the form of Feynman's path integral approach.
DeleteI hadn't come across that notion before, Iain, and thank you very very much. I'll put that on the list of things I should look into, as it seems its fundamental concepts could apply to a lot of my different projects.
DeleteJust read the latest Relative Dimensions post too, and it's another excellent essay.
Very kind, thank you. I can't immediately think of where one would find any great discussion of the philosophical side of Hamiltonian mechanics (the physics are in any standard classical mechanics textbook), but if I come across something I'll let you know.
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