CSI and Design

From the word "unnecessary." In the context of theory, "unnecessary" = "untestable."

says who?

Says the definition of what scientific theories are.Ok, look, why don't you try to come up with the definition of a scientific theory, paying particular attention to the qualities such a construct has.And then, when you have those, examine them and try to see what qualities an entity unnecessary to that theory might posess.This message has been edited by crashfrog, 06-07-2004 07:20 AM

uh, scientific theories are often used to explain things not directly testable.for instance, general relativity states that matter warps spacetime. now, we have no way to actually test this, but it makes predictions all of which we can test.the fact that spacetime can be distorted is untestable in itself, yet ultimately essential to relativity.newtonian mechanics relies on only things strictly testable, and is generally easier to use in most cases, i agree, but it's not always exactly right, and relativity was accepted as more accurate than newtonian mechanics although not entirely invalidating newtonian calculus.i would make an assertion about the testability of string theory, but i don't know anything on the matter.

Theories must be testable. Otherwise they're not theories. That's a well-established principle of scientific methodology.Maybe you don't understand my point. The point of the principle or parsimony is that, given a choice between two theories:a) Atoms are comprised of electrons, neutrons, and protons;orb) Atoms are comprised of electrons, neutrons, protons, and nanoscopic, invisible, undetectable ninjas that have no effect on anything;we choose A because it has the least irrelevant, unnecessary, untestable entities. That's the principle of parsimony. You don't run with the theory with the chocolate sprinkles when the plain ol' theory works exactly as well.It's not clear to me what part of the principle of parsimony you reject, or why you don't think this is a valid part of the scientific methodology. Can you elucidate?

gladly.when we have two theories, and one says"a) Atoms are comprised of electrons, neutrons, and protons;"and the other"b) Atoms are comprised of electrons, neutrons, protons, and nanoscopic, invisible, undetectable things called quarks which may or may not exist at a given moment of time"occam's chooses the first one.given the third choice, "atoms exist and form molecules, but are not subdivisible" that choice would be more admissable were it not for the fact that we can break atoms in accelerators and whatnot.do you see what i'm getting at? "untestable" changes. "insignificant" changes. we don't throw out the lorentz contraction equations (or deny their existance) because it's irrelevent to anything under about half the speed of light, we just ignore it for the purposes of that particular problem.sometimes, though, the equation with more variables can be true.

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uh, scientific theories are often used to explain things not directly testable.
for instance, general relativity states that matter warps spacetime. now, we have no way to actually test this, but it makes predictions all of which we can test.

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I disagree with you here, Arachno. This has been tested using a ground based and plane based atomic clocks. Since the plane was farther away from the gravity well of the earth (ie mass), it's clock ran faster than the ground based atomic clock. It is directly measurable.

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i would make an assertion about the testability of string theory, but i don't know anything on the matter.

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This may hit closer to the mark. However, string theory does make predictions that could be tested in the future (although my knowledge of string theory isn't that great either). Saying that string theory is a provisional theory is an understatement at best, but it can help guide research in the future.

well, yes, i suppose i am in error there then.however, the point was that occam's razor is not a valuable test in establishing the veracity of a theory or law, only evidence can really do that. it is only useful for determining uses of various competing theories.no rational person would use lorentz equations of over v1+v2 or v1-v2 equations to establish the speed of a baseball thrown from moving car, but that does not make the newtonian equations "more right." ultimately, the lorentz ones are, it's just that certain variables become so tiny as to be essentially useless to outcome of the equation, and so there is no point doing huge calculations when arithmetic comes acceptably close.but that does not make lorentz wrong.

I see you getting at a situation where you don't seem to be able to detect the difference between things we can't detect because we don't have the right instruments, or they aren't sensitive enough; and the things that we can't detect because they are, by definition, undetectable.Occam's Razor doesn't slice away the Lorentz contractions because those effects are testable, or would be if our instruments were sensitive enough. It does slice away invisible, ethereal microscopic ninjas because, by definition, there's no instrument that could ever detect them. Who said anything about true? Occam's Razor isn't a statement about what is true. It's a statement about how we construct scientific models.This message has been edited by crashfrog, 06-08-2004 12:57 AM

train a leaves philadelphia headed for new york going 60 miles an hour.train b leaves new york headed for philadelphia going 40 miles an hour.at what time do they pass or collide?and would you use the lorentz contraction equations for this problem? yes, and since we can't go relativist speeds currently, how do contruct models like the part of relativity governed by lorentz?

Is there no effect from contraction whatsoever? Or is there just so little effect that it can't be detected by our instruments?Do you see what I mean when I say that you don't seem to be too careful about keeping track of the difference?BTW what did you mean when you said that we can't go at relativistic speeds? Obviously we're able to - how else do you think we were able to experimentally confirm features of relativity?This message has been edited by crashfrog, 06-09-2004 01:17 AM

option b.not that they're much different, really, especially since untestability is cirterion you listed. if it can't be detected, it's untestable. whether it's the lorentz contraction, or invisible ninjas.i did some calculations in high school for a paper on relativity, using maple. we had to reprogram the bit on significant digits just to get it to show up. i think it was about 40 places in for speeds in the thousands of miles per hour. but i forget.but occam's point was to eliminate such trivial variables, who said "pluralitas non est ponenda sine neccesitate"since there's no need to calculate 40 places of decimals for train trips and not, why have extra stuff? he's not saying anything about untestability, just NECCESITY. and the definition of that is subject to change. well, we can go fast enough to measure time dilation, but i don't think anyone's ever measured the lorentz contraction, and uh, the two major ways features of relativity were tested were precise measurement of the precession of mercury, and observing the way stars of known positions "moved" with the presence of the sun in the sky (during an eclipse).

So then there is a difference, a concievably testable effect from these variables, and so Occam's Razor doesn't apply. What's confusing about that? Those variables aren't trivial, because they have an effect. Variables that would never, under any circumstances, have an effect are removed bu Occam's Razor.You can toss out variables that don't affect anything within your significant digits, but it's not Occam's Razor that's letting you do that. It's a recognition that your model is going to be inaccurate, but not so much that you'll suffer any practical results.But even if you don't agree, we do agree on one thing - we go with the model with the least number of insignificant or outright irrelevant details. So what's the hold-up, here? The half-lives and decay rates of rapidly moving particles are also experimental proof of the time-dialation features of relativity.

There seems to be some mixing up of general and special relativity in these discussions. I guess it's just a nit but the precession of the orbit of mercury and the "movement" of stars is GR. The time dilation due to relativistic speeds is special relavity.

Ye Gods! I just checked the topic. My alter ego contributed to the off topic stuff.Let's keep it to the named topic please.