bascule Posted April 18, 2006 Share Posted April 18, 2006 http://news-info.wustl.edu/tips/page/normal/6845.html While working on their model — a network of interconnected pendulums, or "oscillators" — the researchers noticed that when driven by ordered forces the various pendulums behaved chaotically and swung out of sync like a group of intoxicated synchronized swimmers. This was unexpected — shouldn't synchronized forces yield synchronized pendulums? But then came the real surprise: When they introduced disorder — forces were applied at random to each oscillator — the system became ordered and synchronized. "The thing that is counterintuitive is that when you introduce disorder into the system — when the [forces on the pendulums] act at random — the chaos that was present before disappears and there is order," said Sebastian F. Brandt, Washington University physics graduate student in Arts & Sciences and lead author of the study, which appeared in the January 2006 edition of Physical Review Letters. *boggle* Link to comment Share on other sites More sharing options...
ecoli Posted April 18, 2006 Share Posted April 18, 2006 hardly suprizing... I've always laughed when people define chaos as disorder. Link to comment Share on other sites More sharing options...
insane_alien Posted April 18, 2006 Share Posted April 18, 2006 Explains how i can find stuff so easily in the chaos of my room. i notes for a carpet just now. Link to comment Share on other sites More sharing options...
GutZ Posted April 18, 2006 Share Posted April 18, 2006 Yeah, I know very little about physics, but intuitively (hate that word) seems correct. That's where I get confused with this, because is it really chaotic? Disorder and chaos are totally different things right? I mean if the world changed to a chaotic state vs a disordered state life wouldn't exist right? Anyways, intuitively isn't that the purpose of energy and such, or what it does naturally? I can't really find the words to explain myself here. Essentially though that seems right to me, I see it if it was the other way around life wouldnt exist (Energy, matter, time, and space) Link to comment Share on other sites More sharing options...
Alpha-137 Posted April 22, 2006 Share Posted April 22, 2006 The only chaos in the physics of Nature is when we do not understand all of Nature’s forces a work at that given time. Alpha-137:) Link to comment Share on other sites More sharing options...
insane_alien Posted April 22, 2006 Share Posted April 22, 2006 yes we do. gravity, electromagnetic, weak nuclear and strong nuclear. thats all the force there is. Link to comment Share on other sites More sharing options...
Cloud Posted April 25, 2006 Share Posted April 25, 2006 yes we do. gravity, electromagnetic, weak nuclear and strong nuclear. thats all the force there is. You have 4 types of force there. If I was to exert a force - lets say a straight punch. Would this fall under gravity? Could it be electromagetic? Link to comment Share on other sites More sharing options...
Klaynos Posted April 25, 2006 Share Posted April 25, 2006 You have 4 types of force there. If I was to exert a force - lets say a straight punch. Would this fall under gravity? Could it be electromagetic? The contact will be repultion of the outer electron shells, so electromagnetic. Those are the 4 fundemental forces... Link to comment Share on other sites More sharing options...
Cloud Posted April 25, 2006 Share Posted April 25, 2006 Thanks for clearing that up. I knew it was one of them two. I think it was the "centre of gravity" thing that martial artists endorse which confused me. Link to comment Share on other sites More sharing options...
Gilded Posted May 16, 2006 Share Posted May 16, 2006 Does the Casimir effect fall under any of those four? Link to comment Share on other sites More sharing options...
Severian Posted May 16, 2006 Share Posted May 16, 2006 Yes. The Casimir effect is mainly (quantum) electromagnetism. Link to comment Share on other sites More sharing options...
Rocket Man Posted June 4, 2006 Share Posted June 4, 2006 fractals are a pretty good example, there is chaos, but in the case of manelbrot, there are continuous bands surrounding other continuous bands this can be called a form of order a good book on the topic is "Chaos" by James Gleik. also, there is a recursive formula which creates a chaotic pattern when one of the input variables is higher than 3.5 or so, F(x) = a*x*(1-x) where a is the input constant and x starts out 0<x<1 i havent been able to get a contunuous sequence above 6 though. i have seen a dot diagram of it, at certain levels of a, x will settle into only a few possible values. if you program it, give it time to settle before taking an output also, the initial value of x is important, when it goes negatve, it wont come back. introducing a random element into a random system and getting order out? sounds like an infinite-number-of-monkeys moment. deserves some thought. Link to comment Share on other sites More sharing options...
Locrian Posted June 6, 2006 Share Posted June 6, 2006 yes we do. gravity, electromagnetic, weak nuclear and strong nuclear. thats all the force there is. Pop quiz! Which one of those four is responsible for the accelerating expansion of the universe? (Hint: none of the above) Link to comment Share on other sites More sharing options...
Locrian Posted June 6, 2006 Share Posted June 6, 2006 You have 4 types of force there. If I was to exert a force - lets say a straight punch. Would this fall under gravity? Could it be electromagetic? I'm stirring up trouble here' date=' but... Don't buy this kind of reductionism. Or at least don't pay for it. If you take those four fundamental forces and all the fundamental particles, you can't predict the properties of just about anything, and certainly not the properties of materials you need. Of course, you can't do [i']without[/i] them either, but my point is that merely boiling everything down to its constituents (reductionism) is ineffective. This may be because it is wrong, and there exist emergent phenomena that must be taken into account. Or it may just be that it is just not useful. Either way, keep in mind that our world is full of vast numbers of interesting phenomena, and that filing them away into a few categories is scientifically untenable. Link to comment Share on other sites More sharing options...
Rocket Man Posted June 7, 2006 Share Posted June 7, 2006 I'm stirring up trouble here' date=' but... Don't buy this kind of reductionism. Or at least don't pay for it. If you take those four fundamental forces and all the fundamental particles, you can't predict the properties of just about anything, and certainly not the properties of materials you need. Of course, you can't do [i']without[/i] them either, but my point is that merely boiling everything down to its constituents (reductionism) is ineffective. This may be because it is wrong, and there exist emergent phenomena that must be taken into account. Or it may just be that it is just not useful. Either way, keep in mind that our world is full of vast numbers of interesting phenomena, and that filing them away into a few categories is scientifically untenable. reductionism... (x^2)^0.5 = x? i hate that kind of thing. (equals the absolute value of x if x begins as a real number) Link to comment Share on other sites More sharing options...
JaKiri Posted June 7, 2006 Share Posted June 7, 2006 Don't buy this kind of reductionism. It's only reductionism in the sense that there are only four forces which have any evidence for them. DAMN THAT EVIDENCE. If you take those four fundamental forces and all the fundamental particles, you can't predict the properties of just about anything, and certainly not the properties of materials you need. Well, you can't predict (for example) the form my table takes if you try to work up from the atomic level, but that's more due to our limit of being able to solve the wave equation. Our limit to work with the incredible number of fixed and random variables that exist in this kind of thing. Of course, you can't do without[/i'] them either, but my point is that merely boiling everything down to its constituents (reductionism) is ineffective. Ineffective in what sense? This may be because it is wrong, and there exist emergent phenomena that must be taken into account. Then create experiments to document them. Just saying "science sucks and is wrong" isn't productive in the slightest. Or it may just be that it is just not useful. The model of forces we have seems perfectly useful, from the point of view of, say, modelling how an atom or molecule works, or how they interact, or indeed anything we can in fact measure. If it didn't have some predictive power and didn't agree with observation we wouldn't be using it. Either way, keep in mind that our world is full of vast numbers of interesting phenomena, and that filing them away into a few categories is scientifically untenable. Untenable, eh? "Describing the observeable universe as a finite number of possible types of interactions between a finite number of possible types of particles has not been shown to be inconsistent with empirical evidence and has been useful in predicting various things." Seems perfectly tenable to me. Link to comment Share on other sites More sharing options...
JaKiri Posted June 7, 2006 Share Posted June 7, 2006 reductionism...(x^2)^0.5 = x? i hate that kind of thing. (equals the absolute value of x if x begins as a real number) ±x, actually. http://en.wikipedia.org/wiki/Reductionism for Reductionism. Link to comment Share on other sites More sharing options...
Rocket Man Posted June 7, 2006 Share Posted June 7, 2006 ±x, actually. i said absolute value because (x^2)^.5 only give positive values. it does equal ±x, but |x| is more accurate. Link to comment Share on other sites More sharing options...
JaKiri Posted June 7, 2006 Share Posted June 7, 2006 i said absolute value because (x^2)^.5 only give positive values. What? |(x^2)^½| gives only positive values, (x^2)^½ = ±x. it does equal ±x, but |x| is more accurate. Again, what? Ignoring that I have no idea what you're talking about, ±x gives more information than |x| and so would be more "accurate" by any useful definition of accurate. For example, SQRT(25) = ±5. This has described both possible outcomes. SQRT(25) = |5| is wrong, as |5| = 5 and SQRT(25) = -5 (in one of the two cases) |SQRT(25)| = 5, but it is impossible to tell whether that 5, without the modulus, would be +5, -5 or ±5. Now, if this is you trying to mock reductionism for including less information and being wrong, fine. Go back and make it clearer. If not, then see above. Link to comment Share on other sites More sharing options...
Rocket Man Posted June 7, 2006 Share Posted June 7, 2006 for what values of x can you get negative numbers from (x^2)^½ ? aside from (x.SQRT(-1)) note the qualifier for real numbers the squared term makes the answer positive. in solving for x you would use ±x, but im talking about simplifying the equation yet keeping continuity. Link to comment Share on other sites More sharing options...
JaKiri Posted June 7, 2006 Share Posted June 7, 2006 for what values of x can you get negative numbers from (x^2)^½ ? Any. Squaring something is a many to one function, square rooting something is a one to many function. The square root of 5 squared is ±5; one's not just the inverse of the other. also make sure you balance two sides of your equationsSQRT(5) = 2.24 (2 DP) I used SQRT(5^2) at first, and I lost the ^2 at some point. I did, however, edit it to SQRT(25) some 10 minutes before you posted. Link to comment Share on other sites More sharing options...
Rocket Man Posted June 7, 2006 Share Posted June 7, 2006 Any. Squaring something is a many to one function, square rooting something is a one to many function. The square root of 5 squared is ±5; one's not just the inverse of the other. specify a negative number. it comes out positive. squaring any real number gives a positive result, the square root of a positive number gives a positive result. if you still think otherwise, start a thread in mathematics. however, taking the square root first will provide a negative number via i. i've done a lot of work on index laws, and "not just being the inverse of the other" is exactly my point. you cant simplify something unless there are EXACT inverse functions used ^2 is not the exact inverse of ^0.5 so it should not be simplified as such. I used SQRT(5^2) at first' date=' and I lost the ^2 at some point. I did, however, edit it to SQRT(25) some 10 minutes before you posted.[/quote'] when my post went through, it was still 5. the refresh button may help. my point is, reductionism can be taken too far and often is. it should be used in moderation and all possibilities thouroughly checked. Link to comment Share on other sites More sharing options...
Locrian Posted June 7, 2006 Share Posted June 7, 2006 It's only reductionism in the sense that there are only four forces which have any evidence for them. DAMN THAT EVIDENCE. That's so weird it's hard to respond to. First off, as I noted above, there's evidence for more than four. Secondly, it's still reductionism either way. Well, you can't predict (for example) the form my table takes if you try to work up from the atomic level, but that's more due to our limit of being able to solve the wave equation. Ineffective in what sense? Um, in the sense that you can't use it to solve most problems. For the reasons you stated above. This pair of responses of yours suggests to me that you don't understand what I'm discussing here. Just saying "science sucks and is wrong" isn't productive in the slightest. I never said anywhere that science sucks or is wrong. I'm posting this from my office in a scientific lab. I do work in materials science, and my education is in physics. These opinions I'm expressing here are based both on previously published work (including nobel winners such as Robert Laughlin) as well as my own experience. Nowhere in your post do you really respond to the meat of my argument. I think (though I could be wrong) this is because you are unfamiliar with the subject matter. If there are specific questions I can answer for you I'd be happy to do so. Link to comment Share on other sites More sharing options...
Locrian Posted June 7, 2006 Share Posted June 7, 2006 http://www.pnas.org/cgi/reprint/97/1/28.pdf The emergent physical phenomena regulated by higher orga-n izing principles have a propert y, namely their insensitivit y to microscopics, that is directly relevant to the broad question of what is knowable in the deepest sense of the term. The low- energ y excit ation spectr um of a conventional superc onductor, for example, is completely generic and is characterized by a handful of parameters that may be deter mined experiment ally but cannot, in general, be computed f rom first principles. Now don't get me wrong, Laughlin tends to have a "I've won a nobel prize, I can act batshit crazy" attitude sometimes. But he's always felt this way, and the number of people who agree with him is growing. As an experimentalist, I couldn't care less whether emergent phenomena exist or it is simply a matter of our inability to compute problems using first principles. Either way, reducing a problem I'm facing too far, all the way to its constituents, is a monstrous waste of my time. People learning about physics should have many points of view on this issue, and they are typically only given one. Link to comment Share on other sites More sharing options...
JaKiri Posted June 7, 2006 Share Posted June 7, 2006 Nowhere in your post do you really respond to the meat of my argument. I don't, really. I like to attack arguments in, occasionally stupid, different ways to see if they hold up, or rather, to see how the person proposing this thing I don't know much about holds up. It's been a reasonably successful method of learning about new things; if someone can't hold their position and give evidence in the face of an attack, then it's not really worth learning about. Obviously this works better in an academic environment, when people are more likely to know a fair bit about their subject area, but you seem a fairly intelligent chap. Link to comment Share on other sites More sharing options...
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