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Raft to the Future
November 6, 2006 4:32 AM   Subscribe

Raft to the Future: An article about the weirdness of physical models of the universe, how that weirdness correlates to the inherent incompleteness of mathematical systems, and how time itself can emerge at the fringes of these incomplete models.
posted by knave (46 comments total) 4 users marked this as a favorite

 
I can't even understand the FPP description; you expect me to understand the article?
posted by zardoz at 5:08 AM on November 6, 2006


Cute idea, but it depends fatally (it seems to me) on scare-words like "strange" and "weird" that have no actual scientific content. And this bit is so dumb it makes me doubt the parts I don't really understand:

We're used to casually naming numbers like three or pi. Unfortunately, almost all the quantities in between such familiar numbers can't be named or described, because it would take an unbounded amount of effort just to refer to them.


Dude, the reason we can "casually name" pi is that we named it pi. We can do the same with any "quantity in between" you want named. Pick a number, any number: 2.123456789123456789...? I dub it "Moe." Presto, we can talk about pi, three, and Moe! What was your point again?
posted by languagehat at 5:17 AM on November 6, 2006


That was pretty interesting.
posted by Bugbread at 5:19 AM on November 6, 2006


I've been thinking about this, albeit on a much more basic level: if reality arises from math (and math isn't merely post-hoc descriptive), and math is incomplete, wouldn't there be certain aspects (or places, or times) of reality that are incomplete, or inconsistent, or discontiuous, glitches in the matrix, as it where?
posted by signal at 5:23 AM on November 6, 2006


Actually, it's a little deeper than that. You can prove that the set of numbers which are computable (that is, able to be approximated by a computer to arbitrary accuracy) is fundamentally smaller than the real numbers. Numbers like pi, e, 3, and the solution to any equation you can ever possibly write down are all small compared to number of numbers in between them. There are more numbers that one can't figure out any way to describe than there are numbers that one can.
posted by Schismatic at 5:26 AM on November 6, 2006


languagehat: "Dude, the reason we can "casually name" pi is that we named it pi. We can do the same with any "quantity in between" you want named. Pick a number, any number: 2.123456789123456789...? I dub it "Moe." Presto, we can talk about pi, three, and Moe!"

I think he understands that, and it isn't really a contradiction of his argument. Note that he says "named or described". Moe is an easily described number (I'm no mathematician, so I'll use English instead: "Write a 2, then a decimal, then the numbers 1 through 9 in order, and repeat that 1 through 9 string forever"). So it's casually describable. Pi is also casually describable: "the ratio of a circle's circumference to its diameter in Euclidean geometry". You can't casually describe an example of a number that isn't casually describable, because that's a logical impossibility.

I don't think it's a cornerstone of his argument either way, but nothing in that bit on pi jumped out at me as being remarkably illogical.
posted by Bugbread at 5:27 AM on November 6, 2006


Hm. OK, that makes sense, and I withdraw that portion of my complaint. I still think his heavy reliance on "weird" is deeply suspicious.
posted by languagehat at 5:51 AM on November 6, 2006


I love the way mathemagicians spin research grants out of nothingness, rather than wasting their time with all that "practical" stuff.
posted by imperium at 6:06 AM on November 6, 2006


This bemuses me. There's something about connecting our continually extending knowledge of mathematics to a continuing progress of time that just doesn't seem right, especially considering that the laws of physics seem to be pretty static and not progressing. But there's really not enough detail in the article to understand it.

Also, although he's working with a man who knows what he's talking about, his own bio doesn't inspire me with confidence if he's planning on coming up with a fundamental theory of reality.

And I wish there was some sort of Godwin's Law that applied to this:
'The universe—or God, if you like'
posted by edd at 6:18 AM on November 6, 2006


Reality is complete, but we don't have a math that works yet. We have some problems with units, for one thing. Also, that whole relativity thing is a load of horse ----.
posted by ewkpates at 6:39 AM on November 6, 2006


Also, that whole relativity thing is a load of horse ----.
posted by ewkpates at 8:39 AM CST on November 6



....


Perhaps you could be a bit more specific?
posted by lazaruslong at 6:42 AM on November 6, 2006


Weird (hehe).

I was just browsing through a website on Process Physics (link), which 'start[s] from the premise that the limits to logic, which are implied by Gödel's incompleteness theorems, mean that any attempt to model reality via a formal system is doomed to failure.'

In the article 'Is Reality A Side Effect Of Randomness?' that superficially explaines the theory, I came upon the quotes

'[The] theory [of Process Physics] has taken the principle of intrinsic randomness or incompressibility and applied it to reality. [...] The endless recombination of this random, undetectable "information" has a startling effect - structures start to appear in the web of connections. [...] [and] as a result of residual "faults" or "kinks" in the connections, quantum matter is emergent.' (near the bottom of the linked page, direct link to PDF).

I don't fully grasp Process Physics and the Raft article is a bit too simplified to make any direct connections, but I had the feeling these two things might have something in common and wanted to throw it into the discussion.

On preview: I think there are many people that qould disagree with you on that, ewkpates. The radical constructivists, for example.
posted by Glow Bucket at 6:44 AM on November 6, 2006


that should be would, not qould.
posted by Glow Bucket at 6:46 AM on November 6, 2006


wasting their time with all that "practical" stuff

An engineer, a mathematician, and a physicist are staying in three adjoining cabins at a decrepit old motel.

First the engineer's coffee maker catches fire on the bathroom vanity. He smells the smoke, wakes up, unplugs it, throws it out the window, and goes back to sleep.

Later that night the physicist smells smoke too. He wakes up and sees that a cigarette butt has set the trash can on fire. He says to himself, "Hmm. How does one put out a fire? One can reduce the temperature of the fuel below the flash point, isolate the burning material from oxygen, or both. This could be accomplished by applying water." So he picks up the trash can, puts it in the shower stall, turns on the water, and, when the fire is out, goes back to sleep.

The mathematician, of course, has been watching all this out the window. So later, when he finds that his pipe ashes have set the bedsheet on fire, he is not in the least taken aback. He immediately sees that the problem reduces to one that has already been solved and goes back to sleep.

more here

posted by bashos_frog at 6:47 AM on November 6, 2006 [1 favorite]


This article sounds like the author came up with what he thought was a really cool model of the universe while stoned. Unlesss his model can be incorporated into existing theories to give testable predictions, it's useless.

The only thing that kept me from dismissing it outright is the mention that he's working on this idea with Lee Smolin. The question is, does Lee know he's working on this idea too?
posted by justkevin at 6:49 AM on November 6, 2006


No offense, but this article was crap. It was just one big stupid metaphore. Someone reading the article learns nothing.

Crap science writing at it's worst.
posted by Paris Hilton at 6:50 AM on November 6, 2006


There is a lot of hand-waving and dodgy bits that seem rather out of place in so bold an article, culminating in the stunningly superfluous sentance, "'The universe—or God, if you like".

Curiously, the article is written by Jaron Lanier, who wrote the previously discussed controversial essay on 'Digital Maoism', which I and others were very critical of, notably for a lack of logical cohension and similar hand-waving.

I wonder if there is really any point proposing an explanation of the universe via relativity, loop quantum gravity and incompleteness in such a tiny amount of words, lacking anything remotely techincal.

That said, I don't have anything like the background to judge the technical merit of the article, but I do find this kind of over the top language in a scientific article discourages taking it seriously (though the Smolin fellow appears to know what he is talking about).
posted by MetaMonkey at 7:00 AM on November 6, 2006


On non-preview: what everyone else said.

The only thing that kept me from dismissing it outright is the mention that he's working on this idea with Lee Smolin. The question is, does Lee know he's working on this idea too?

I thought the same thing, my google search could pull up nothing connecting the two other than in unrelated matters, and Lanier writing about Smolin's work.
posted by MetaMonkey at 7:03 AM on November 6, 2006


Quite possibly a load of bunk. M Theory, depends on string theory, but is string theory even science?

An amusing debate. That reminds me a little of the recent discussion fizzling out here presently. They don't quite start telling each to fuck off, so you may not find it worth the bother, gave me a giggle though. This is about as snarky as it gets:

Hmm... "new predictions". Is that how this new terminology you have invented goes?

Whoa there cowboys..!

Both links contain Peter Woit of Columbia University.
posted by econous at 7:10 AM on November 6, 2006


Smolin NS article via jaronlanier.com.
posted by edd at 7:25 AM on November 6, 2006


Quite possibly a load of bunk. M Theory, depends on string theory, but is string theory even science?

String theory is mathematics, one that may lead to a model which describes our universe. Finding a mathematical model that underlies everything we know about the universe is useful, even if it ends up not being testable. Newton, Liebnitz, those guys weren’t doing "science" by those standards. They were looking for a beautiful model of the world.
posted by Paris Hilton at 8:19 AM on November 6, 2006


String theorists really, desperately want to come up with predictions. They just haven't figured out the math (yet). They do start with many presumptions that reflect our current knowledge of natural law. Rather than saying that they're doing math, or they're not doing science, I'd describe it as "doing science in slow motion" ---it's going to take awhile to get to the hard predictions.

Also, this article was pretty bad. In addition to the previously harped-on "The universe—or God, if you like", the mention of time as "emergent" gets my dander up. Working in the field of complex systems makes it apparent that the word "emergent" is like a magic word. Oh, time is emergent? Mystery solved!

Finally, relativity is NOT a load of horse shit. I can understand why you'd think that it is, given how poor the pop-sci explanations of it are. All I can say is, you don't disagree with relativity, you only disagree with the (inaccurate) image of it that you have in your mind.
posted by Humanzee at 8:26 AM on November 6, 2006


Heres an interesting critical reaction to Smolin's theory and NS article.
posted by MetaMonkey at 8:28 AM on November 6, 2006


Well as a scientist with a strong background in physics, I was intrigued by the first page anyway. Page 2 sounded like a load of bollocks to me, but my familiarity with advanced theoretical mathematics is spotty at best, so perhaps one needs to be more familiar to really understand this. Which seems unlikely to me since it's in Discover magazine. Discover is like the red headed step child of scientific journals. You have Science and Nature, then Scientific American which is mainstream and readable, and then Discover which is so basic and diluted that people wouldn't have need to read it if our education system wasn't so crappy. So the real question is this: There's an article in Discover that I don't understand, how can this be? Must be bollocks.
posted by Farengast at 8:39 AM on November 6, 2006 [1 favorite]


Paris Hilton: Maybe I should have left it at the 'is it science' bit. Although I'm left wondering at the utility of it if it's not testable. Can there be any practical application for it in that case? I hope we end up the more than an elegant model.
posted by econous at 8:47 AM on November 6, 2006


Paris Hilton: Maybe I should have left it at the 'is it science' bit. Although I'm left wondering at the utility of it if it's not testable. Can there be any practical application for it in that case? I hope we end up the more than an elegant model.

Well I don't know, I would certanly not call myself an expert in it. But look, this is the comparison they made:

The latest Cosmic Log column on msnbc.com concerns Lawrence Krauss’s new book Hiding in the Mirror and the author asked Krauss a question I'm expecting that physicists will be hearing more and more often as time goes on: "Why is string theory science but intelligent design isn't?"

In other words, how is it not like ID. Well let me tell you how it's not, it's not a deliberate fraud perpetrated in order to fool scientifically illiterate people believing that all of science is a conspiracy. ID isn't just not science it's anti-science, deliberately created to destroy knowledge and reduce our trust in the ability of science in general.

The problem with string theory is that it isn't complete. People are still working on the math, once the math is done then you can do the tests.

It’s like building a supercollider. The actual building of the supercollider isn’t "science" but once its done you can start with the 'scientific' stuff.
posted by Paris Hilton at 9:02 AM on November 6, 2006


Related previous post.
posted by weapons-grade pandemonium at 9:08 AM on November 6, 2006


Wow, MetaMonkey's link is great.
posted by Humanzee at 9:16 AM on November 6, 2006


Paris Hilton : "Well let me tell you how it's not, it's not a deliberate fraud perpetrated in order to fool scientifically illiterate people believing that all of science is a conspiracy."

Damn IDers, trying to convince people that gravity and the doppler effect are part of the conspiracy! Keep your hands away from the concept of light refraction, you bastards!
posted by Bugbread at 9:28 AM on November 6, 2006


String theory needs some kind of experimental validation, but that doesn't mean one should dismiss it entirely. As I recall, Bohr's work on the structure of atoms was (initially) largely unsupported by hard data; it was, however, an elegant solution that fit observations. Subsequent research modified Bohr's model, the essence of which turned out to be quite correct.

Now to this article - there is a bit of "handwaving", but this is not a peer-reviewed journal; it's a consumer-level science mag. If Discover published the mathematical underpinnings of this concept, many an intelligent eye would glaze over, because there just aren't that many people that can follow the conversation at that level.
posted by Mister_A at 9:43 AM on November 6, 2006


The problem occurs when those of us who've invested the time necessary to understand general relativity and quantum field theory read this stuff and can't follow his ideas. Then it becomes clear that most likely he's talking out of his ass. He gives it away in the final act with the universe=God crap.

This is a serious problem with pop-sci, especially in physics. Sure, you have to get rid of equations, and that poses a problem, but I think it's vital to remove the equations without replacing them with lies. Some authors can do this, some can't. I think Brian Greene is good at this, Steven Hawking is TERRIBLE. When I read his stuff (almost never, now) it takes me forever to figure out what the hell he's talking about. Half the time he's on crack (reversal of the thermodynamic arrow of time) and the rest of the time he's thrown in stuff that simply doesn't belong in there (like his "imaginary time", which is simply a bad description of a math trick used to solve certain equations). The Steven Hawking approach appears to be dominant, because it's weird and sounds deep, and sells books. If you read something and think "that guy was toking when he wrote that", then it's probably bad pop-sci. If the author invests a lot of time trying to convince you that the subject matter is strange and incomprehensible, it's definitely bad pop-sci ---the goal of science writing should be to bring as much clarity and understanding as possible, not to muddy the waters.
posted by Humanzee at 10:22 AM on November 6, 2006


No philosophical problems here for us neoplatonists, this view is essentially what was discussed thousands of years ago. The super-symmetric object which contains the possibilities of math is the One apprehended by Intellect (as the Greeks meant it) and the incompleteness of math arises from the fact that no finite formal system can possibly reflect the infinite symmetries of the One. The progressive Realization of the One is what brings about the illusion of time.

(props for the "process physics" mention!)

But yeah, this would have made a better blog post than pop-sci article, there's no chance the average NS reader will get more than titillating fuzzies from it.
posted by sonofsamiam at 10:45 AM on November 6, 2006


His network metaphor is a bit strange. Network addressing makes no sense one we start talking about millions of rafts? Ahem, Jaron, let me introduce you to the Internet.

In any event, it seems to me that his hypothesis fails in that he is conflating a model of reality for reality itself. But then I'm an amateur, and a rusty one at that.
posted by moonbiter at 10:47 AM on November 6, 2006


All that aside, this got me thinking about some interesting questions, like "What the hell is math, anyway?" I always thought of math as a low-res model of the physical (or "real") universe; now I'm wondering if I've got it backwards...
posted by Mister_A at 11:34 AM on November 6, 2006


The Discover article seems facile. Maybe there's content to back it up, but the way it skips steps of reasoning reminds me of that Sidney Harris cartoon. Perhaps he should be more explicit in step 2.

It's a huge leap to go from "formal systems are incomplete" to "one will always need more laws of physics."

The counterpart to Godel's unprovable truths in physics may be such things as the n-body problem for n=3 or more. Perhaps some questions such as: "will Pluto ever leave the Solar System?" do not have computable answers, but that shouldn't require amending Newton's laws.

I'm not sure if the n-body problem quite qualifies, but the unprovable statements in Godel and Turing all have "there exists" or "for all" grouped over an infinite set like the natural numbers or possible programs with certain inputs and outputs.

Most relations between Godel and physics are crackpot, but John Baez endorses this particular mathematical formulation of Godelian incompleteness in terms of Heisenberg uncertainty. I haven't read it yet though.
posted by Schmucko at 12:35 PM on November 6, 2006


“it depends fatally (it seems to me) on scare-words like "strange" and "weird" that have no actual scientific content.”

By all scientific measures the Debigulator has a quantifiable hyperbolic topology weirdness factor of .03 on the Frink scale, mw-hey.

(I’ve always liked the tongue in cheek version of the universe = God argument - because of the ultimate implications and negation of imposed meaning (from the non-theistic pov)....dunno where he’s going here tho.)
posted by Smedleyman at 12:41 PM on November 6, 2006


We have some problems with units, for one thing.

Only in the US, Liberia and Myanmar.
posted by spazzm at 1:34 PM on November 6, 2006


Schmucko: I've read that preprint a few times since it came out; there's nothing crackpot in it.
posted by sonofsamiam at 1:36 PM on November 6, 2006


The problem occurs when those of us who've invested the time necessary to understand general relativity and quantum field theory read this stuff and can't follow his ideas. Then it becomes clear that most likely he's talking out of his ass. He gives it away in the final act with the universe=God crap.

It's crap Crap, wank, mental masturbation, garbage garbage garbage.
posted by Paris Hilton at 5:16 PM on November 6, 2006


moonbiter:

His network metaphor is a bit strange. Network addressing makes no sense one we start talking about millions of rafts?

I think the idea of the raft metaphor is trying to describe how one moves from a discrete (i.e. quantum) system with few rafts to a continuous (i.e. relativistic) system with infinitely many rafts. Mathematically, I think he is describing the process of dequantization (I swear I'm not making this up) whereby one takes operators on a quantum system and produces functions on the phase space of the associated relativistic system.

The point is that the transition is from discrete to continuous. If each raft is a point in space, it makes more sense to describe position based on distance than by labelling each point with a name. So the internet is a bad example, because it's still a finite, discrete system.
posted by number9dream at 5:26 PM on November 6, 2006


number9dream:

More specifically I think he's trying to describe spin networks. It's not a bad metaphor.

The problem is to describe directions in space entirely in a relational way. If you have two quantum mechanical systems with a certain amount of spin each, when you put them together are they going to find they are spinning in opposite directions, the same direction, at right angles, etc.?

Roger Penrose a long time ago (60s?) came up with probability rules for combining 2 dimensional spin networks that gave the same answers you'd get for combining particles with quantum mechanical spin in real 3 dimensional space.

So a theory of space directions was built up from how separate systems orient themselves in a relative way.

Then these spin networks turned out to have a fundamental role in Loop Quantum Gravity (they are the basis states of space.)

I'm partial to the creative thinking that seems to go in the LQG community but this Discover "Raft" essay seemed a bit... untethered.
posted by Schmucko at 6:46 PM on November 6, 2006


"His network metaphor is a bit strange. Network addressing makes no sense one we start talking about millions of rafts? Ahem, Jaron, let me introduce you to the Internet."

It's all tubes!

On a philosophical level, this has some interesting connotations for rationally-based systems (which is most of what the political systems of the west post-Enlightenment are), given that the rational systems assume that there are constant and unchanging natural laws that are consistent and can be apprehended.

But by the time I was finished with the article, all I could think of was that there didn't seem to be any real insight or evidence behind a huge handwavey metaphor.
And granted, I don't understand the math when written as math, but I do generally understand mathematical and physical concepts, and there didn't seem to be a lot there. Like, I kept thinking "That's interesting... Can you prove anything?"
Oh, and it's always weak in the lead to state that the audience won't understand the concept.
posted by klangklangston at 8:38 PM on November 6, 2006


And can anyone gimme a quick layman's version of the n-body problem?
posted by klangklangston at 8:40 PM on November 6, 2006


I found the article raised some interesting questions to think about next time I get high. I hope that future generations can look back on our primitive attempts to know "what time is" and laugh at us because the answer is so basic to them. Then they'll get back in their time machines and go hang out with Jesus and Einstein some more.
posted by aliasless at 9:36 PM on November 6, 2006


I'd assumed the article was written for non-scientists. Putting things in layman's terms almost always requires wonky metaphors. So, being a non-scientist who appreciates being spoon-fed metaphors for things I don't have the background to fully comprehend, I guess I don't see why this article ruffled everyone's feathers so badly.

All that aside, I kept thinking of Badiou's attempt to re-orient philosophy by proclaiming that ontology is mathematics.
posted by treepour at 9:42 PM on November 6, 2006


The reason why this is a crock is because it's based upon the notion that mathematics is "real", a part of the physical universe, like a Platonic Form or something. Math isn't "real", it's just a tool we use.

For example, in most commonly-used versions of arithmetic, dividing by zero yields an unintelligible result. But that doesn't cause some corresponding unintelligibility in the physical universe. There isn't some trans-dimensional warp or temporal loop that's created because you can't divide be zero in the arithmetic that we use to build mathematical models in the scrience of physics.

Now that fact does cause problems in the models themselves - a motivating factor in the investigation of string theory is that, if elementary particles are really points in space, the elementary forces, which all operate on inverse-distance laws, would approach infinity as distance approaches zero.

But problems in the models don't cause problems in reality itself, it just means that the models are inadequate - that we aren't as smart as we think.
posted by XMLicious at 5:24 AM on November 7, 2006


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