Physical laws are the most carefully intertwined network of mutually supporting principles I know of. Things that you might think would be completely unrelated to each other turn out to be tied together in subtle and remarkable ways. This is the beauty of the field, the poetry and the mystery. And like all beautiful, poetic and mysterious things, physics is also extremely useful. It enriches the life of the person who understands it in myriad ways, and even people who don't understand it get the benefits of its secondary uses, such as designing more fuel-efficient transport, better aircraft, and the like.
It's worth noting, however, that until very recently the role of physics in invention was rather small. Until the Second World War, in fact, it was almost negliable, except in the sense of crudely guiding empirical investigations. The Wright brothers, for example, were mechanics, not physicists, and a great deal of their work was based on the results from the wind-tunnel they invented, not on theoretical understanding, although the theory of their day would have provided some guidance. A deep understanding of the physics of flight wasn't developed until well after people were flying.
The contribution of physics to technology has been two-fold: one to suggest avenues of approach, as E=mc^2 suggested that transmution of matter into energy was possible, and stimulated the invetigation of nuclear power and weapons, and the other to help understand and refine existing technology, to discover the general principles underlying the empirical truths. Until recently--say the last fifty years--the contribution of physics was almost exclusively of the latter kind, and that is still its dominant role.
This is travelling far afield from the course of my argument, but it provides some needed insight and besides, its fun to talk about. The deep, apparently unexpected connections between different areas of physics have, I think, a common, over-arching principle, that unites all of physical law. The principle is the general invariance of unknowability. There are certain things that "Man Was Not Meant To Know", and physical law is finely tuned to make sure that woman can't know them either. That is, there are certain things that are--that must be--unknowable to everyone, absolutely, in princple. If they weren't, then the wheels would fall off the universe.
There are things that exist in some as-yet-to-be-defined sense, but that are--that must be--unknowable. The difference between indistinguishable particles is like this--the particles are different, we know this because there are more than one of them, they aren't the same particle; but there is no way of knowing what the difference is. We know this, as I will eventually explain, because we know the number of states available to some systems of particles.
What do I mean when I say the wheels would fall off the universe if these things were knowable? Not known--it's hard to emphasize this enough--but knowable. I'm not asking some sophmoronic question about whether the moon is still there when nobody looks--I'm asking, "What are the constraints on the nature of any object when no one can look." And the "can" here is not the "can" of logical possibility, but the much stronger "can" of physical possibility.
I'm getting far ahead of myself here, but what the heck. Consider all these incoherent claims a promisory note that can be redeemed for future explication.
When I say the wheels would fall off the universe, I mean that existence--the sort of existence necessary for human life--depends on these things being unknowable. Kant correctly pointed out that there were a bunch of conditions that the universe had to fulfill to make knowledge possible. His vast mistake, which spells the death of his program, was to assume that those conditions were products of the nature of consciousness, and that we could not know if the universe violated them. Violations simply would be beyond our ken.
As it turns out, and this is one of the long-term points of this argument, John Bell showed that we can know that the universe violates Kant's constraints--the physics of human experience does not seem to be all the physics there is. While experimental violations of Bell's theorem show a dramatic and obvious violation of Kant's constraints, the results came as no great surprise to a lot of people (I wasn't one of them--they surprised the hell out of me) and in particular I think that had Heisenberg lived to see them he would have said, "Well, yes, this is what is implicit in the theory."
What I am, eventually, going to argue for here is that Kant's conditions on knowlege--notably causality, but also temporality and spatiality--are not conditions of consciousness as such, but conditions on the universe that must be fulfilled if conscious beings are going to evolve there. Consciousness--knowing--does depend on Kant's conditions being fulfilled. But it turns out that they are fulfilled by the physics of the world of experience, and that we can and do know that there is a larger frame that holds this world where Kant's conditions are violated. We can't know very much about that larger frame, simply because creating the conditions required for knowing about it would making knowing--to say nothing of living--impossible.
This is what I mean when I say the wheels would fall off the universe if any of the unknowables hidden by the veil of the uncertainty principle were revealed: the things that would have to be true for that to happen would make knowing impossible, because they would violate Kant's conditions on knowing, which I think are, at least roughly, correct.
I really didn't intended to undergo this particular excursion today--I'd thought to talk about heat, which I will try to get to tomorrow. The thoughts that provoked this little rant have to do with various traditional unknowables in thermodynamics--the physics of heat--such as the impossibility of constructing Maxwell's Demon, which I think are somehow related to the other unknowables I'm writing about here.
The strongest form of the Law of Causality I've come up with is:
The added strength of the "only" is required to capture the invertability of the law: not only do things do what they do because of the way they are, we can know the way they are by knowing what they do. If things other than what they are can cause things to act as they do, then we could not know what they are by simply knowing what they do, and because all we can know is what things do, then if we are to know what they are we must use this strongest form of the law. Without it, we have no warrant for infering identity from action.
It's important that there are no alternative means of infering identity. That is, I've assumed that all we can know is what things do, and therefore aspects of a thing's identity that do not influence its actions in time and space are unknowable. This does not mean, however, that they don't exist, and this is part of the point of the argument I've been developing under "Physics".
You'll note that I've introduced "time and space" in the above description of action. This is important, for this is what it means to act--it means to change over time in a way that is somehow spatial in character, at least to the extent that we can say, "some entity at this point in space is now different than it was". This is something about which I will have more to say later.
While giving in to a persistent cold last night I watched Outland, the late '70's outer-space Western with Sean Connery. It's an entertaining film, playing on the motifs of the classic Western (not a genre I'm much taken with) and playing off the anti-heroic feelings of the time.
Heroism was not in vogue when I was growing up. "War hero" in particular was more likely to be used as an ironic epithet aimed at some purported American baby-killer who had served in Vietnam than to refer to the children who died at Vimy Ridge or Pashendale or storming Juno. My generation got the better part of that particular bargain, and my children will grow up knowing Wilfred Owen rather than John McRae.
But heroism, for all that it has routinely been used to manipulate people--mostly men--into dying willingly in droves, is a good thing. It's all a matter of what you think is heroic, and I realize now that I had the benefit of a few heroic individuals, mostly teachers, growing up, without whom I'd've never reached very far beyond my unprepossessing beginnings.
The question O'Neil--Connery's character--gets asked repeatedly in Outland is: "What are you trying to prove?" and what he's trying to prove is that heroism is possible. He's trying to prove that even a loser like him can aspire to be something more.
In doing so, he convinces two others to try as well, and one of them dies in the attempt. That's part of what heroism is: putting your life into what you do. The reason why heroism is important is that's what we all do: we put our lives into what we do, into the choices we make. Every day, every hour, every minute, we lose a little bit of our lives. Heroism is daring to spend that time the best way we know how, to commit ourselves to choosing our own course, rather than just drifting along with the currents of time. It's hard--though far from impossible, as many excellent examples attest--to dramatize that sort of thing, so we get the tightly plotted heroic drama instead, where the hero faces a problem that's simply packaged and finite.
It's unrealistic as hell, but that's not the point; the point is to remind us that our choices, our lives, day in and day out, matter. The point is that the person we have to make a difference to is us, not anyone else. And if we drift along aimlessly we betray the best within us.
Looking through one of my stacks of things I haven't got around to reading yet, I came across a collection of romances in Middle English yesterday, and after a brief perusal am glad I only paid $5 for the book. Most early English poetry is not that good--Beowulf stands out for that very reason. The romance is not really a very natural English form, and heroic couplets are really not my cup of tea. I might give "Havelock the Dane" a try some rainy day, but this stuff was mostly written for recitation at feasts where the audience could be counted on to be mostly drunk and probably more interested in swiving the serving wenches than following the plot, and it shows.
I've had Fagles Iliad lying around for a year or so, and think this might be the time to dive into it. I was disappointed by his Odyssey, particularly because I had very high expectations--his translation of Agammenon is so good that I honestly don't know how to praise it sufficiently. The power and rhythm of the language is overwhelming, and yet it never loses its subtlety. It's a frivolous comparison, but it reminds me of a production of Evita in which the chorus was a military drill team, who marched and stamped to the music, intertwining the simplist, repetitive rhythms with the more subtle rhythms of the melody (being Evita, of course, the melody wasn't much more subtle, but I said the comparison was frivolous, didn't I?)