Uncommon Descent Serving The Intelligent Design Community

Brownian Motion, Reynolds Number, Supersonic Flight, and the Danger of Mindless Extrapolation

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At very small scales, the disturbances caused by the random motion of molecules in a liquid is called Brownian motion. This is why bacterial flagella must spin at such high RsPM (Revolutions Per Minute, not Revolution Per Minutes). They must overcome the random motion of the particles in their watery environment. The propeller on the back of a motor boat does not have to deal with Brownian motion.

In fluid dynamics there is Reynolds number, with which we must deal in aerospace R&D. What this basically says is that we cannot make small models of an aircraft flying at low altitudes and extrapolate this to large aircraft flying at high altitudes, or vice versa.

The leading edge of an aircraft wing produces a compression wave that travels at the speed of sound. This gives the air molecules time to diverge and flow around the wing. At the speed of sound, all the rules change. The innocent air molecules are struck by the wing structure with no warning, and the fluid properties of the air become much more solid-like. This can cause catastrophic results, such as the control surfaces (e.g., ailerons) acting like the trim tabs do on the ailerons, warping the wings and causing control reversal due to aeroelastic effects. This caused many deaths during the early days of the exploration of supersonic flight.

The bottom line concerning Darwinism is this: The mindless extrapolation of bacterial antibiotic resistance to explain all of life’s complexity, information content, and virtually everything else, is just plain stupid and has nothing to do with science. Experience has demonstrated that nothing in the well-understood, mathematically modeled physical sciences can be extrapolated forever without the rules changing, often quickly and without warning.

Comments
Well folks I hope you don`t mind a green thumb giving a stab at what I feel has got a touch of feminine confusion for me anyway.I hope you are trying to go faster,farther,safer and cheaper.If not,will try when know for sure.In your Brownian Motion,the flow design ahead of propeller or intake is not equal to or balanced all the time with the designs you have used so far.The designs needed to over come these concerns don`t sound too complicated yet.I have not studied flying that I know of but neither have I of many other not supposed to knows either.Reynolds Number-Have to change drag and resistance design and extrapolation of air will be less.Too much drag and push.The plane design and propeller design has to change.Front of wingshave to be designed for air flow through-not around.Taking everything away is not always stupid.One has to cross the line of balanced to know where it is.One has to do what one has to do til one learns.A lot of blame seems to be emphasized on over extrapolation. Sounds as if some are wanting to land as soon as they are in the air.About a year ago I spent some all nighters doodling with a compass/pencil and ruler sketching wind mill blades that could be propeller blades as well and air sleek rough plane designs and had forgotten about them until now.Now I understand why.Hope you were only fishing so far.Dr. Time
January 8, 2009
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I'm not sure what Brownian motion has to do with the working RPM of flagella. Brownian motion can be informally defined as the random oscillations of microscopic solid particles suspended in a liquid which are typically discernible to the eye, and are driven by aggregate thermal motion of the liquid molecules. Not sure what suspended microscopic solid particles have to do with flagella or boat propellers.groovamos
January 4, 2009
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If criteria 1-3 apply to all designed matter I really wonder how you guys can beleave in free will?
I would say criteria 1-3 apply only in specific scenarios- For example what Gil was responding to. And BTW Gil- it wasn't mindless extrapolation of bacterial resistance- I would say that was well planned, ie designed. Bait-n-switch is as old of a tactic as there is. Why do you think that the NCSE does NOT tell people that that "evolution" is not being debated, rather the debate is about A) Origins and B) Mechanisms? THAT is by DESIGN! It is all to manipulate the psychology of the mob. Get people to think that 1) ID = Creation and 2) Creation = fixation of species, and the rest is easy. It doesn't matter if it is all a big lie. Without the media outlets to correct that lie the mob will never know about it. Heck who needs science when all you really need is a propaganda machine like the NCSE?Joseph
January 3, 2009
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1) The algorithm is designed with foreknowledge of a goal. 2) The code is designed and optimized by computer programmers. 3) The hardware on which the code runs is designed. 4) The intermediate goals are predefined and contrived to be within the reach of the search strategy at every step. The intermediate goals are also given scores to evaluate the closeness to the goal numerically.
If criteria 1-3 apply to all designed matter I really wonder how you guys can beleave in free will?sparc
January 2, 2009
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Haven’t evolutionary strategies been successfully employed in fluid dynamics? The "evolutionary strategies" to which you refer are simple trial-and-error algorithms that have a well-defined goal, and carefully crafted code that supplies well-defined heuristics which ensure that successive approximations to the goal can be reached with the computational resources in a reasonable amount of time. This is the exact antithesis of the Darwinian mechanism in biology at every step: 1) The algorithm is designed with foreknowledge of a goal. 2) The code is designed and optimized by computer programmers. 3) The hardware on which the code runs is designed. 4) The intermediate goals are predefined and contrived to be within the reach of the search strategy at every step. The intermediate goals are also given scores to evaluate the closeness to the goal numerically. This has absolutely nothing to do with "evolution" in a Darwinian sense. It's basically a variation on hill-climbing search algorithms.GilDodgen
January 2, 2009
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Haven't evolutionary strategies been successfully employed in fluid dynamics? Unfortunately, I currently don't have access to Ingo Rechenberg's article "Case studies in evolutionary experimentation and computation" (Computer Methods in Applied Mechanics and Engineering Volume 186, Issues 2-4, 9 June 2000, Pages 125-140). However, you will find examples on his homepage (http://www.bionik.tu-berlin.de/institut/xstart.htm).sparc
January 2, 2009
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Gil, I believe that the real reason that physicists, chemists and engineers must validate their extrapolations, but biologists get to extrapolate without having to prove it is that the worlds of physics, chemistry and engineering have proven succeptible to a raft of naturalistic theories, where biology can only find one. Any new theory that a biologist would put forward which is naturalistic would be given full ear. The fundimental challenge that the ID community offers is that we are requiring a paradyme change. The closest that physics has come to needing a paradyme change has been with the big bang. The bang faced fierce resistance until a couple of naturalistic theories (big crunch, and multiverse) allowed the big bang to be viewed within a naturalistic context -- who cares how poorly.bFast
January 2, 2009
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This is yet another area in which Darwinian theory is given a free pass that is not tolerated in any other science: unverified extrapolation. In the physical sciences things don’t work at large scales like they do at small scales, or at high speeds like they do at low speeds, or at low viscosity like they do at high viscosity. Essentially nothing can be extrapolated forever as an explanation. Only in Darwinian theory is it acceptable to talk about finch beak variation, dog breeding, and insect pesticide resistance, and then claim with full assurance that these phenomena can be extrapolated to explain the origin of everything in biology. And the bizarre thing is that these theorists are almost never called on this unsubstantiated extrapolation, even by their colleagues in the hard sciences. If a physicist, chemist, or engineer engaged in this kind thing he would be challenged immediately to provide empirical evidence that the extrapolation was justified. Of course, those who make such challenges in real scientific disciplines need not fear losing their jobs or reputations, as do those who challenge the Darwinists.GilDodgen
January 2, 2009
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Very well put.William Wallace
January 2, 2009
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