My last “first” college entry of this semester – Science A-22: Chance, Necessity, and Order. This was a philosophy of science class as well as a conceptual introduction to 20th century physics. So not the typical “Physics for Poets” class, with non- or low-math versions of basic topics in physics. In that sense, different from Ec 10 which I took the same term, which is more of basic concepts but without the heavy math.
This course looked like an interesting way to fulfill my Science A requirement (physical as opposed to life science). Professor Layzer (yes, great name for this class) also taught in alternate terms another course called Space, Time, and Motion, which for some reason I can’t remember is what I wanted to take. I’m glad I ended up with this one. The title of the course hinted at questions of free will and determinism which at the time were interesting to me religiously, and still are though in a different way. This class was also taught much more through small sections and weekly short papers, rather than big lectures and a few high stakes exams and long papers.
I’m reviewing this after having perused most of the readings in the sourcebook the past year or two, as my daughter has also been studying physics in college. Also I just remember that Professor Layzer was a great writer, and most of the readings I remember were from the draft of his book, so I have liked perusing his chapters from time to time over the years.
Here are a few things that strike me from the first few weeks; definitely not a summary of those weeks.
I wrote a paper early on about scientific description vs. explanation. My point seemed to be that the goal of science is or should be to describe, and that unlike in the social sciences, the best “explanation” is actually a really complete description. Otherwise explanation comes from outside, and injects the explainer’s vantage point; the more that is or needs to be “explained”, the less good the underlying objective description must be.
Another topic that seemed to be a focus was discreteness vs. continuity, or discreteness vs. probability. Classic physics was about the interaction of discrete items, even at the atomic level such as it was understood – even early Greek scientists posited that at the most microscopic level would be some kind of indivisible “ball.” Causality is related to discreteness – this thing hits that thing with a direction and an energy, and then they each move after in certain ways as a result.
I’m also wondering – this is me now, not me then – whether discreteness is actually a difficulty for causality. I picked up a metaphysics textbook of my daughters (forgive me if I mentioned this before) and read about causality, and one thing I took away was that causality fits continuity, the fluid transition or transfer from one thing or state to another. The “jump” from one discrete thing to another, or of motion or energy from one discrete thing to another, is a kind of discontinuity, and maybe that’s problematic for the “flow” of causality?
This is also me now, not sophomore me: at first the quantum discoveries about electrons having specific energy levels was consistent with the idea of light photons having discreteness. I think?
But eventually at the very microscopic level it was discovered that there is no fundamental discrete particle, bounded in space at a specific time. Not just that we can’t observe this, due to limitations on our instruments — but because that’s not the nature of the “thing.” It’s probabilities all the way down; there is no way to freeze time and say “this is what the universe looks like in this instant.” That’s what broke Einstein.
I know that I periodically ask my daughter what a force “is”, or what energy “is” — like is it a property of a thing that then gets transferred to another thing. She explains (I think) that according to Einstein, what Newton called force is just an artifact of the way things affect the shape of time-space, so all things are just “falling” or “following”, not being driven by some external thing in addition to their own matter and/or energy.
One session we had was about the conservation of energy, and whether it makes sense to speak about that as a “law” when we don’t have a good definition of what energy is. Could it be that we are arguing in a circular way – whatever the property is which is conserved, we just call that “energy”, and if something seems to be disappearing or showing up, we fiddle with the label? One thing the law does, though, is generate predictions which hold true. The antineutrino was discovered after the law “demanded” that it exist. So on the one hand energy looks more and more like a mathematical rather than a “physical” reality, but on the other its properties seem to be “real.”
Another interesting note I saw: since one way of looking at energy is as different ways to describe a capacity to change, nothing in the universe is ever truly static.
The question of quantum probabilistic-ness (?) is up to now in the course one source of indeterminacy in the universe. The next thing is the concept of entropy in thermodynamics, and the complementary scientific notion of order. Order is a property of “macrostates”, which are statistical clusters. A “macrostate” with certain properties can be instantiated by a number of different “microstates.” So every cup of water looks like every cup of water, even though in two cups of water the microscopic arrangement of every single molecule might not be exactly the same. Order is a property of macrostates. The question is: is that order a “real” thing or just a subjective imposition by the (human?) observer again? I think I’m understanding that according to thermodynamics, order is also “real”, in that entropy is measurable and entropy can be compared between two systems or two times.
Also there is the question of the direction or “arrow” of time. At the microscopic level, any reaction or interaction looks just as scientifically possible in one direction as the other – if you saw a “videotape” of a specific interaction at a small enough level, you couldn’t tell if it was being run forward or backward. In that sense, time is not a property of the microscopic. Yet at more aggregated levels, clearly a closed system can only change in one way and not the other, by scientific laws.
So that’s all fascinating, and the question I think Professor Layzer posed by this point is whether what we experience as freedom or chance is actually a product of microscopic indeterminacy or not.
I was tickled by the fact that the quantum theory of light was for Planck a convenient mathematical tool only – he imagined these “oscillators” stuck to emitters of blackbody radiation to make his correct observations and calculations work. Even though they had continuous or wave qualities consistent with prior theories of light as waves, Planck posited that they were sort of programmed to only work at specific frequencies. For Einstein (and I guess others around the same time) the quantum theory of light as particle-like was real, with tremendous implications.
I’m also intrigued now in a way I’m sure I wasn’t originally by the parallels between quantum theory and relativity in physics, and Adam Smith’s economics. Both were ways of describing the world that were not just refinements of what we can observe, more cultivated ways of seeing what we normally see and describing categories and relationships with more nuance. Both were at the time of their origins equally strange, as fundamental descriptions (not interpretations) that jumped off from brand-new starting points, that centered something far from the realm of everyday experience and that in fact distrust the human observer as a center point.
I will say that a couple things in the notes, particularly around microstates and macrostates, aren’t as clear to me now as I thought they were then. Maybe they weren’t so clear then either; I read my papers and they seem to be coming close to but not entirely nailing certain concepts. I can see myself straining. Which is great! College should be a time when you reach and sometimes don’t get it, without being rapped on the knuckles too much. It’s still important to know the difference between getting it and not, but if you don’t take intellectual chances you limit yourself. I see that during this semester, I’m experiencing a lot of something I know I didn’t much in high school, which is a level of not-getting-it and being able to live with that, to strive but also not to beat myself up too much when I fell short and others around me seemed to have a better hold on something.
Leave a Reply