June 23, 2005

IRREDUCIBLE (via Robert Schwartz):

'A Different Universe': You Are More Important Than a Quark (KEAY DAVIDSON, 6/19/05, NY Times)

EVERY child knows how to learn what makes a toy work: bust it open. In that sense, we're all born reductionists, whose philosophy holds that anything can be explained by breaking it into its component parts. By analyzing them, one discovers how the parts act together to produce larger phenomena. If you crack open a windup clock, you can examine its gears to see what makes it tick.

Some people resent reductionism because it sweeps away many mysteries. Behind spooky phenomena, reductionists have shown, are the ordinary ticktocks of nature's machinery, the concealed ropes and pulleys of cosmic-scale Penn and Teller tricks. Indeed, reductionism has reinforced the old philosophical suspicion that there is something vaguely unreal about ''reality'': as the Greek philosopher Democritus said, it's all just atoms and the void. To a hyper-reductionist, the invisibly small microworld is more ''real'' than everything else. Bigger objects -- cats, toasters, people, the sun, galactic superclusters -- are just second-order consequences. The atoms or quarks or leptons (or ''strings,'' if you follow the latest trendy theories) are what count, while you and I are just ephemera.

It's a disillusioning view, but so far it has yielded undeniable benefits. By breaking matter into atoms, subatomic particles and subatomic forces, and by disassembling living organisms into such discrete elements as cells, genes, enzymes and so forth, scientists have learned much about how nature works, and how we can make it do our bidding.

Inevitably, reductionism has been overused. Not everything can be reduced to cosmic nuts and bolts. In the emerging sciences of the 21st century, many researchers are dusting off an old saying: ''The whole is more than the sum of its parts.''

A recent example: many molecular biologists once thought the chemical information stored on DNA coded for the full complexity of living organisms. But a few years ago, the Human Genome Project revealed people have far too few genes (not many more than a roundworm) to account for the kaleidoscopic complexity of the human body. By itself, it appears, DNA cannot explain it any more than you can infer the United States Constitution from the traffic laws of Topeka. Somehow, biologists propose, higher-level ''organizational'' or ''emergent'' principles switch on at larger sizes, such as on the scale of proteins.

Even physicists, wizards of the nonliving realm, are talking about emergent properties. Their change of heart is not easy, though, as Robert B. Laughlin, who received a Nobel Prize in Physics, shows us in his important, brain-tickling new book, ''A Different Universe.'' [...]

Talk of emergence makes many scientists nervous. The word, after all, has been co-opted by all kinds of people who have bowdlerized it, along with once precise terms like ''holistic'' and ''paradigm,'' for trivial purposes. More pertinent, emergence seems to defy common sense, just as the notion of the sphericity of the earth once did. There are no emergent principles in money, for example: 100 million pennies equals $1 million, not an emergent $2 million. To our primate brains, the whole is the sum of its parts. But when I once griped about the counterintuitiveness of quantum physics, a scientist at the University of Illinois replied dryly, ''Common sense is a poor guide to the nature of reality.''

Laughlin's thesis is intriguing, if not completely persuasive. I can't help wondering if hard-core reductionists will eventually explain emergent phenomena in reductionist terms; they've pulled rabbits out of hats before. Still, his thesis reminds us of the great value of something most physicists assume they can live without: philosophy. Behind the seemingly concrete principles, practices and instruments of any laboratory, there are certain philosophical assumptions, often unexamined. In the 19th century physicists were hypnotized by the myth of the cosmic ether, an invisible medium through which light rippled, as waves ripple across a pond. In 1905, Albert Einstein, then a young patent clerk, awakened them. Likewise, Laughlin says, physicists face a philosophical ''crisis'' over emergence, ''a confrontation between reductionist and emergent principles that continues today.'' In the history of science, philosophical crises often precede scientific revolutions.

This year is the 100th anniversary of Einstein's revolution. In Laughlin's view, another physics revolution is coming. He mocks speculations in the 1990's about an imminent end of science: ''We live not at the end of discovery but at the end of Reductionism, a time in which the false ideology of human mastery of all things through microscopics is being swept away by events and reason.'' To invoke a familiar metaphor, physicists have fruitfully spent the last century trying to map every twig, acorn and bird's nest in the trees. Now it's time to step back and see the forest.


I've never understood how people could believe in an infinitely large universe/existence but also in a basic particle. Mustn't each particle we discover be made up of smaller ones ad infinitum?

Posted by Orrin Judd at June 23, 2005 8:33 AM
Comments

If you are a reductionist, it's particles all the way down.

Posted by: Ed Bush at June 23, 2005 10:03 AM

Seems that 'must' is a strange word to be using about the universe, given our current level of understanding...

Posted by: b at June 23, 2005 10:29 AM

Mr. Judd;

Because there is a "smallest" length, the Planck Length. On the other hand, the search for a grand unified theory of physics is in effect a search for the bottom layer of particles. One notes that as we've broken hadrons in to smaller particles (quarks) and those in to even smaller ones (strings), leptons (such as the electron) have remained undivided. So we've likely reached at least part of the bottom.

I agree with the author that "emergent phenomenon" has been abused basically the same way as post-modernism. The latter does have interesting things to say about reality and our percerption of it, but it went wrong when it was taken as an explanation instead of tool.

On the other hand, I disagree that the information for higher levels isn't embedded in the lower ones. The law analogy for DNA is exactly backwards – one can't deduce the traffic laws for Topeka from the US Constitution, the latter being a better analog for DNA. Laws for emergent phenomenon are simlpy more compact representations the more fundamental properties. Such phenomenon are hard for us to predict but that's just an artifact of our limited processing capabilities. It's not clear that a sufficiently capable intellect (e.g., God) couldn't work it all out ahead of time. Heck, I do that all the time in my job, just on slightly smaller scale :-).

Posted by: Annoying Old Guy at June 23, 2005 10:54 AM

> There are no emergent principles in money

Charles Dickens: "Annual income twenty, annual expenditure nineteen-and-a-half,
result happiness. Annual income twenty, annual expenditure twenty-and-a-half,
result misery."

Emergence is all about interactions.

Posted by: Bob Hawkins at June 23, 2005 11:38 AM

Ed Bush -

Turtles.

Posted by: ghostcat at June 23, 2005 11:40 AM

What's half a Planck Length?

Posted by: oj at June 23, 2005 1:03 PM

As an historical aside -- it was the Michelson-Morley experiment which disproved the existence of the aether, not Einstein.

Posted by: jd watson at June 23, 2005 1:11 PM

The same as a Planck length divided by zero. Neither means anything.

Posted by: joe shropshire at June 23, 2005 1:22 PM

I think it's a mistake to try to draw conclusions about the specific contents or structure of the universe from abstract philosophical principles. Philosophy always gets into trouble when it tries to deduce the way the universe "must" be.

The way to learn about the universe is to go out and study it. Don't try to infer it from your armchair.

Posted by: Kyle Haight at June 23, 2005 1:44 PM

Now I remember why I didn't like physics.

Posted by: erp at June 23, 2005 2:14 PM

The Planck length, just like a black hole singularity, is merely an attempt to quantize our ignorance. Current theories don't apply on all physical scales, so until some new theory comes along we'll just have to do with making up terms to avoid saying "I dunno."

Posted by: b at June 23, 2005 2:24 PM

Kyle:

The opposite is true.

Posted by: oj at June 23, 2005 2:34 PM

Mr. Judd;

Half a Planck Length is a specific distance. But we do not know of any physical action (even in theory) which can distinguish between a Planck Length and half a Planck Length. At that scale distance is irrelevant.

The Planck Length is effectively the "grain size" of physical reality.

b;

Unlike black holes, which are just a side effect of general relativity, the Planck Length is fundamental to quantum physics. One can create physical theories that do not permit the formation of black holes (and there are astrophysicists who do so), one can't have quantum physics without some sort of Planck Length. Quantum physics makes reality fuzzy which necessarily creates a minimum length which is lost in the fuzz.

P.S. In deference to erp, I won't discuss Planck Time.

Posted by: Annoying Old Guy at June 23, 2005 2:57 PM

AOG:

So it does indeed paqrticulate further, we just can't m,easure it so it doesn't matter? As previouslu quarks, atoms, etc. didn't matter. You're getting as subjective as Harry in your dotage.

Posted by: oj at June 23, 2005 3:05 PM

AOG: Sheesh. There is no such thing as a singularity! If your mathematical equations give you divisions by 0, say, when you're trying to describe something in the universe, it just means your math does not apply to the scenario you're trying to model, NOT that your theory "permits" the formation of black holes.

Ditto for quantum theory. I have little doubt that in 100 years physics will be based on a currently unknown formulation that makes all the same predictions at the scales which we now have applicable theories for, and probably smaller (as we all know quantum gravity is required for), and no one will use a "wave function" to do calculations except for the intellectual descendents of the same strange types who nowadays use slide rules--more of a curiousity than anything else.

Posted by: b at June 23, 2005 3:22 PM

b:

The paradigm always awaits the next shift.

Posted by: oj at June 23, 2005 3:57 PM

Mr. Judd;

The particles can't measure it either. Our ability to do so or not is irrelevant. We don't know if things particulate further than quarks.

b;

Actual black holes are still speculative and there's reason to believe they'll evaporate before the singularity forms (ask yourself – from the point of view of a flat space observer, how long does it take matter to fall across the event horizon? How long does it take the black hole to evaporate? So which one happens first?). So, it may well be that the divisions by zero don't describe anything in the universe. It's not my point that my view here is correct, merely that's it's plausible and therefore space time singularities aren't fundamental to general relativity.

Posted by: Annoying Old Guy at June 23, 2005 4:23 PM

AOG:

Of course we do--but we also know we can't measure further...yet...

Posted by: oj at June 23, 2005 4:29 PM

Try ever.

Posted by: joe shropshire at June 23, 2005 4:37 PM

ah, solipsism, the plague of the rationalist.

Posted by: oj at June 23, 2005 4:41 PM

No, that's not solipsism, any more than it's solipsism for you to confidently predict that we'll be able to keep discovering new subdivisions in matter for the next ten thousand years, simply because we have been able to for the last 300 or so. It's just a prediction.

Posted by: joe shropshire at June 23, 2005 5:14 PM

We know everything that will ever be known. Book it, eh?

Posted by: oj at June 23, 2005 5:26 PM

Not at all. However, we are measuring distance as finely as we'll ever measure it. Book that.

Posted by: joe shropshire at June 23, 2005 5:46 PM

You got it Mercator!

Posted by: oj at June 23, 2005 5:52 PM

"I disagree that the information for higher levels isn't embedded in the lower ones. The law analogy for DNA is exactly backwards one can't deduce the traffic laws for Topeka from the US Constitution, the latter being a better analog for DNA. Laws for emergent phenomenon are simlpy more compact representations the more fundamental properties."

I disagree. there is nothing in DNA that tells us how the mind works. The DNA is a set of instructions that tell the cellular construtors how to build a brain. The mind results from a complex interaction between the brain and the enviroment, and impounds far more information than the DNA could possibely carry.

Posted by: Robert Schwartz at June 23, 2005 5:59 PM

Who, aside from religionists, believes in an infinitely large universe?

Posted by: Harry Eagar at June 23, 2005 8:46 PM

You think this universe all there is or ever has been? That's a tad too harryistic even for you.

Posted by: oj at June 23, 2005 9:09 PM

Who, aside from religionists, believes in an infinitely large universe?

Cosmologists, Harry! Infinitude's all their latest rage, unless of course I'm missing some important distinction between an accelerating universe and an infinite one. Are you trying to tell us you know when Time Comes to an End? Quick, get Ratzinger on the line!

Posted by: joe shropshire at June 24, 2005 12:40 AM

joe: No, the accelerating universe does not mean that the universe is infinitely large, it means that the expansion will go on infinitely long and therefore the eventual size is unbounded, i.e. infinitely large. Since as far as we know there was a start point, the expansion hasn't been going on forever. Imagine if I give you a dollar today and give you twice as much on each subsequent day as the previous (i.e., I accelerate the rate at which I give you money). There is no limit to how much money I will ever give you, but at any point in time you do have some well defined amount of money. Capiche?

Posted by: b at June 24, 2005 11:13 AM

What I just said, b: lim (t -> ∞ ) r = ∞. Unless Harry's got a fortune cookie in his overcoat with the universe's end date on it.

Posted by: joe shropshire at June 24, 2005 11:35 AM

joe:

Harry can see the horizon, so existence is finite.

Posted by: oj at June 24, 2005 11:40 AM

b:

How did it start?

Posted by: oj at June 24, 2005 11:58 AM

joe: That's not what infinitely large means. If you could freeze time, it would not take you infinitely long to traverse the entire size of the universe. Just because the universe will be bigger tomorrow than it is today and so on forever doesn't make it infinitely large.

Posted by: b at June 24, 2005 12:09 PM

oj: You've read the Book.

Posted by: b at June 24, 2005 12:13 PM

b:

So time is infinitely large.

Posted by: oj at June 24, 2005 12:18 PM

oj: Assuming the currently accepted model of the accelerating expansion is fully correct. It should be, considering it's been established for nearly a decade.

As was mentioned yesterday, there's far more to know than we know...

Posted by: b at June 24, 2005 12:32 PM

expansion begs the question.

Posted by: oj at June 24, 2005 1:07 PM

b: the only thing "infinite" can mean to us moderns is "increasing without bound" (nice explanation, by the way.) Any other definition is just woolly-headedness, of the sort oj is permitted to indulge in but Harry is not. You're right of course that at present (in fact at any time t0) the universe has a finite radius r0; if it is accelerating, though, for any r > r0 there will be a t1 > t0 such that r1 > r. I'd say that's infinite enough by the rules we rationalists set for ourselves.

oj: whether time is in fact infinite is an open question. Time's arrow points along the entropy gradient, but in the very distant future, say 10 to the 1000 years from now, it may not be possible to measure one. By that time the universe will have decayed to such a uniformly cold, dark, thin state ( no stars, no galaxies, in fact no protons or electrons, just a soup of neutrinos and the odd byproduct of their unimaginably rare interactions) that time's arrow may not point in any discernable direction. So Harry may eventually get off the hook, but not for a good long while yet.

Posted by: joe shropshire at June 24, 2005 1:50 PM

joe;

increasing begs the question

Posted by: oj at June 24, 2005 2:08 PM

oj: no, it makes it possible to give the question a definite answer. Like it or not, in this age we define things by how we measure things. If to you that reduces an irreducible mystery, sorry. We keep you around to worry about irreducible mysteries so we don't have to.

Posted by: joe shropshire at June 24, 2005 2:51 PM

joe:

yes, impose enough restrictions and you can answer anything any way you want to. You stop discussing reality though.

Posted by: oj at June 24, 2005 3:11 PM

oj: imposing no restrictions at all has the same effect, no? You don't strike me as a Blakean mystic.

Posted by: joe shropshire at June 24, 2005 4:09 PM

There are no restrictions in reality.

Posted by: oj at June 24, 2005 4:42 PM

If it has a boundary now, it is not infinite now.

No matter how much more it expands, it will always have a boundary. So it will always be not infinite.

That's for space.

For time, no matter how many seconds elapse, an infinity of additional seconds stretches out ahead, unelapsed.

So time is not infinite, either.

Sheesh. The mathematics of infinity is over a hundred years old. It's like you guys never heard of it. Which is probably the case.

Posted by: Harry Eagar at June 24, 2005 6:27 PM

Ah, Harry, so self-absorbed, you can only imagine forward, since you're here for it, never backwards, since it didn't involve you.

Posted by: oj at June 24, 2005 8:27 PM

If it has a boundary now, it is not infinite now...

Of course visible space has a finite radius now (10 billion light years, right?) I said that twice myself. And I was most explicit, right from the get-go, that I was dragging future expansion into the discussion. Which I consider more than appropriate, seeing as how you're defining "the universe" in such a way as to facilitate one of your usual pleasantries about religion. Next time try being polite. Which brings us to:

an infinity of additional seconds stretches out ahead. So time is not infinite, either

I'm pretty sure you'd like to have that one back, Harry, particularly in light of your chest-thumping about math. oj's question ("so time is infinite?") wasn't just talking about time already elapsed since time zero. Another reason to try civility: you're more likely to RTFQ and less likely to make stupid mistakes like that.

Posted by: joe shropshire at June 24, 2005 9:08 PM

joe:

No, he isn't. It's a harrycentric universe so he'll always be merely amusing.

Posted by: oj at June 24, 2005 9:18 PM

Until they tick off, the unelapsed seconds are merely imaginary, they have no existence, so cannot count as part of the universe. There is no guarantee that they will tick off, either.

In fact, when I was a Christian we were taught that comes a time when they do stop.

As long as more seconds can be imagined than have ticked off (always the case), then time can never be infinite.

This is just elementary Cantor set theory.


Posted by: Harry Eagar at June 25, 2005 12:49 AM

What fun! The future is wholly imaginary, the past wholly real? That's feeble on every imaginable ground, Harry. (We'll get to Cantor in a minute.) Epistemologically, it's true that we can't experience the future directly, only imagine it. But it's just as true that we can't experience the past directly, only remember it; or for cosmological timescales, draw inferences about it from our present state. Ontologically, yours is one position with two competitors (presentism and block theory) in a philosophical dispute dating back to Zeno (500 BC?) which has no resolution in sight. Physically it's dubious: with the exception of the weak force the physics you know is symmetric with respect to time. And Stephen Hawking ( "One can think of ordinary, real, time as a horizontal line. On the left, one has the past, and on the right, the future...") doesn't agree with you. So knock it off and quit being such a crank. When we say time, we mean to include past, present and future in the ordinary immemorial way. You can, if you please, mark that off as a succession of seconds, which renders time into a countable (aleph-null) infinity; or if you prefer the real number line you can mark it off as aleph-one. So much for Cantor.

Posted by: joe shropshire at June 25, 2005 3:07 AM

Harry:

But an infinite number have already ticked off. It is of course your faith that you live within a fixed set that makes you so lovably silly to behold.

Posted by: oj at June 25, 2005 7:46 AM

He's perfectly welcome to infer that there was a time zero. He's not welcome to reduce the entire idea of time to "time already elapsed" and then prance around as though he'd done something clever.

Posted by: joe shropshire at June 25, 2005 12:12 PM
« NO WONDER THEY LOST THEIR EMPIRE: | Main | KEEP SENDING THEM, WE'LL MAKE MORE: »