Tuesday, December 18, 2007

I'm the Law in This Town

The Science Times has an article up entitled "Laws of Nature, Source Unknown". It is about physical laws and the questions about their existence.

It's the standard popular level article about physics: quotes from Einstein and Feynman, ideas thrown around about string theory and multiverses, all that and more.

It does mention the recent kerfuffle surrounding the Paul Davies op-ed (which, if you were unaware, that op-ed has produced a lot of responses), in which Davies argues that science is grounded in faith that the universe is orderly. I think that's hogwash, but I won't get into that now; see the numerous responses above for commentary.

I solicit your comments on "Laws of Nature". I'm conflicted a bit. Read the article and tell me what you think.


Blake Stacey said...

I have the ill-formed idea that the way in which Nature is "orderly", the (so to speak) character of physical law, does not mesh with any everyday meaning of "order", and instead can only be approached the hard way, by spending a lot of time studying the science. My notion of "order" is informed by many concepts, from symmetry principles and group theory to Kolmogorov complexity. Because this understanding of "order" is the result of centuries of experimental and theoretical inquiry, trying to address it with pre-scientific tools is like trying to play Icelandic post-rock on a Neolithic bone flute.

Ben said...

"Anton Zeilinger, a physicist and quantum trickster at the University of Vienna, and a fan of Dr. Wheeler’s idea, has speculated that reality is ultimately composed of information. He said recently that he suspected the universe was fundamentally unpredictable.

I love this idea of intrinsic randomness much for the same reason that I love the idea of natural selection in biology, because it and only it ensures that every possibility will be tried, every circumstance tested, every niche inhabited, every escape hatch explored. It’s a prescription for novelty, and what more could you ask for if you want to hatch a fecund universe?"

I think it is reasoning like this that bothers me the most. Philosophy of science can sometimes be too emotional. As a scientist, it is important not to throw the most support at the idea that feels right. There is something to be said for intuition. but when it comes to the ultimate nature of our reality, the only way we are going to be able to approach the truth is through careful, emotionless science. That being said, I do not think that there is anything wrong with having a favorite theory or having one that you think would be the most philosophically satisfying. For me, I think it would be if our universe was just another blip in a sea of others just like it. If we could show that our universe could arise from natural laws that we can find while sitting here on our pale blue dot, then I think we could be more confident in the law we have already established. However, if that does not happen to be the case, I will happily follow the evidence wherever it leads.

At the moment, I think it is safe to say that the universe we can see is highly ordered and predictable. Maybe I'm crazy, but it seems like we do a pretty good job at modeling everything we see. Sure there are unsolved problems, but they do not seem infinitely out of reach.

I do love the famous Einstein quote though. It is quite amazing that we can know anything about the universe at all.

Blake Stacey said...

Is it, though?

If the world were so wild that even experiments which only probed the grossest features of physical phenomena did not have predictable outcomes, then could beings with reason and durable memories even exist? Could anything like life arise, reproduce and evolve?

That's an "anthropic" argument, of course, so season with salt appropriately. When you put them up against technical details, anthropic arguments start to flail and make unhappy noises. For example, why is proton decay suppressed by twenty orders of magnitude beyond what would be necessary for life on Earth? And what about those extra generations of particles — who ordered them?

One can argue that if science were really, really hard, then life itself would be impossible, and therefore we wouldn't be here to fret about science. However, to explore this conundrum more fully, we have to have an understanding of what it means to say that the Universe is "ordered". All too often, this is merely thrown into a discussion as a banal debate-stopper: science is possible, so the Universe is orderly, so the whole thing was made by Jesus, Amen. But what content does this invocation of "order" truly have? What would it mean for the Universe to be a little less ordered, or a little more predictable?

Ben said...

Oh I do agree that the fact we are here at all and are able to investigate our surroundings implies some sort of order. If there were neither rhyme nor reason to physics, I think stars and planets let alone life would be very unlikely. I just consider myself lucky to exist at all.

Flavin said...

Blake: I have the ill-formed idea that the way in which Nature is "orderly", [...] does not mesh with any everyday meaning of "order", and instead can only be approached the hard way, by spending a lot of time studying the science.

What do you mean by "order," if not the conventional usage?

I linked this page in the article, so forgive me if you've already read it. This response to the Davies op-ed applies equally well, I think, to this discussion of law and order (no pun intended) in the universe. A pertinent quote: We describe [universal] structure in terms of laws. Sure, we assume that the universe has a structure, for without that assumption we cannot gather knowledge [...] but the description of laws is just a provisional summary of what we now know. Just as there is no Fidoness other than the dog standing in front of you, there is no "lawfulness" out there in the universe, just a structured world.

Blake Stacey said...

Does the conventional meaning of "order" include the idea that outcomes of experiments are random, but that the probabilities of those random outcomes are governed by elegant mathematics? Does it include a clause for simple laws generating complex phenomena? What about the puzzle of some laws (Newtonian mechanics) reproducing themselves as you make larger assemblages of particles, while other laws (e.g., quantum mechanics) fail to do so?

I'm not trying to ask rhetorical questions here. I just think that the term "order" covers a broad territory, and has connotations which do not map onto physical law, if you take your connotations from the everyday knowledge base, and then reason about them in a verbal way.

Flavin said...

I think you're right. I think what we as scientists mean by "order" or "orderly" does not mean "5b: a regular or harmonious arrangement <the order of nature>" from Merriam-Webster.

At least for me, when I think of order, I just mean a certain predictability or repeatability. And I think that takes us back to the original NYT article in the following way: nature is predictable in innumerable different ways, some of which are reliable enough and can be written down succinctly enough for us to call them "laws." The article asks, whence come these laws? It's not asking if there is order and what is the nature of the order, because the article presupposes that these laws exist and can be found.

And that is where I disagree with the article. As in the last comment I made, I posit that natural laws don't have any meaning beyond what we give them. The universe just works, we describe that working by laws, but those laws aren't anything other than our description. The NYT article is slanted towards the view that the laws we see have a special status as the universal control algorithm or something, while I think that is bollocks.