A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: Ste on 28 Feb 2010 02:05 On 27 Feb, 15:58, PD <thedraperfam...(a)gmail.com> wrote: > On Feb 26, 6:59 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > There's a variety of things one can do (and are done). > > > 1) Explore other candidates, though at a level that is commensurate > > > with risk-benefit analysis of the effort involved. > > > 2) Continue to do other tests of this model vs other models to see > > > where the 5% might lead (to either opening it up to 40% or closing it > > > to 98%, say) > > > 3) Let the community by itself determine organically which volunteers > > > from the community will plumb the 5% doubt. > > > 4) Design a bunch of devices that are based on a 95% assurance that > > > the principles of that model are correct, again weighing risk vs > > > benefit on the chance this is a mistake. > > > That's fair enough in abstract. But the question is still who pursues > > which avenue, and what subjective perception they have of the > > likelihood of a particular theory being correct. > > Yes, and that is done by self-selection. In the community of > scientists, the presumption is that open questions will be addressed > by someone eventually. And there is reward in the community for that > adventurism. The assessment of the risk vs benefit of the adventurism > is made individually. Indeed. But it is then a sociological question, to ask which scientific questions are answered and which are not, and why.
From: Peter Webb on 28 Feb 2010 02:07 "Ste" <ste_rose0(a)hotmail.com> wrote in message news:859fe48e-4473-4e46-ab5d-16cf91687eac(a)z11g2000yqz.googlegroups.com... On 27 Feb, 15:44, PD <thedraperfam...(a)gmail.com> wrote: > On Feb 26, 6:34 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > The fact that this conceptual model in a raw form > > > > can permit predictions that are so permissive as to make almost no > > > > prediction at all, does not mean they are not an essential component > > > > to scientific enquiry and advance. > > > > No testable predictions = not science. Possibly philosophy, possibly > > > fiction, possibly drug induced free association speech, possibly > > > gibberish, > > > possibly an incredibly profound insight into human emotions, possibly > > > masturbation. But not science. Science makes testable predictions. > > > (Note > > > that this is a necessary but not sufficient condition. Astrology also > > > makes > > > predictions, just very poorly). > > > I think you're attributing an absurd definition to "science". Paul > > Draper probably had a more tenable argument when he said that string > > theorists are scientists doing science, but that they do not yet have > > a "scientific theory". But I know from talking to him that he > > attributes a very contorted meaning to the phrase "scientific theory", > > that would condemn a lot of scientific knowledge, both historical and > > current, as being "unscientific". > > Examples, please. In physics I would raise the same old example: string theory . But there are certainly more. We have things like "dark matter". Or even Newton. Or Galileo. And more broadly, in biology we have evolution, and in economics, rational choice theory. __________________________________ All of these things are falsifiable, or they are not scientific theories. I don't know much about string theory, but the rest are certainly falsifiable. Newton's theory was in fact falsified by observation. In another part of the thread, I gave you half a dozen ways evolution could have been falsified. All managed to fail your previously stated requirement of a "scientific theory", which (amongst other things) is being falsifiable (in a practical rather than just notional sense), not ad-hoc, and predicting observations that are not already accounted for. _______________________________ I didn't state any of these requirements other than it was falsifiable. All of those theories are, at least as I understand them, with the proviso I know zero about string theory and not a lot about some of the others. I have already demonstrated how many of them in fact could be falsified.
From: Peter Webb on 28 Feb 2010 02:45 I'm confused, because I thought we previously agreed that two observers travelling along the same axis, maintaining equidistance from both events at all times, would both report each event as simultaneous with the other event. And moreover, if they not only both maintained equidistance from both events, but if they maintained a separation which was equal for both observers (which, if both observers are moving relative to each other, requires either a collision course between observers, or travel in diametrically opposite directions), then there is no question that the signals are received simultaneously. Illustration: E1 -------- E2 The line represents the line between events E1 and E2, along which the observers may move while always reporting both events to be simultaneous. _________________________________ You still don't get it. You can say two events appeared to simultaneous or "were" simultaneous in *some* inertial reference frame. That does *not* mean they appeared simultaneous or "were" simultaneous in some *other* reference frame. The concept that is lost is "absolute simultaneity", not "simultaneity within a particular reference frame".
From: Ste on 28 Feb 2010 03:37 On 27 Feb, 16:10, PD <thedraperfam...(a)gmail.com> wrote: > On Feb 26, 7:15 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > On 26 Feb, 18:14, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Feb 25, 10:47 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > You have then questioned why you should adopt the scientific metric > > > for "working". And the answer is, you don't have to. It's just that > > > when you decline, you're no longer doing science. > > > But this lends credibility to my assertion in the first place, which > > is that science is a religion. > > No more than the practice of law, medicine, music, architecture, or > plumbing, as we've discussed. Practitioners of law and medicine are undoubtedly ideological. Music and architecture can undoubtedly be put to ideological uses, and are invariably informed by the predominant ideology. I'm not so sure about plumbing however. > You've said those are different because the stakes are somehow higher > with science. I also disputed that. Did I say that? I don't recall saying that, and if I did say it I can only imagine it was said in a different context. > Just because there is an agreed-upon methodology by the collective > that practices in the discipline does not warrant that discipline > being called a religion, at least as I understand the meaning of > "religion". There is more to religion than an "agreed-upon methodology", but there is more to the practice of science than this, too. > > > > Indeed, you have utterly failed to point out any contradiction yet, > > > > all you have done is constrain the behaviour of gravity tighter than > > > > what is otherwise possible in the conceptual understanding that I > > > > have, and as such amounts to "added detail" and leads to further > > > > accuracy, rather than requiring a fundamental conceptual overhaul. > > > > I *have* pointed out the contradiction. Gravity that falls off > > > linearly with distance is incompatible with elliptical orbits. What is > > > true is that I have not demonstrated this enough to you that your are > > > convinced that it is a contradiction. That is different. That is a > > > *teaching* task. I don't know that I owe it to you to *convince* you > > > of anything, though I may be inclined to point to a fact or two that > > > might spur YOUR OWN investigation into why that statement is true. > > > I'm afraid I don't accept this Paul. It's not a contradiction, because > > my model didn't make any firm statement in the first place as to the > > quantity of fall-off. > > Hedging your bets? There is a difference between saying, "My model > says there is a fall-off but isn't certain what the fall-off is" and, > "My model is perfectly consistent with a linear fall-off". The former > statement is correct but renders the model useless because it provides > practically no information other than what could be painted on a comic- > strip panel. The latter statement makes a stronger claim but leads > immediately to a contradiction. > > Your choice, then. Either a statement that is so vague that is useless > but unfalsifiable, or a statement that is testable and wrong. I think I was quite clear from the outset that the statement was vague almost to the point of uselessness. But it is not totally unfalsifiable, because it could be falsified by the observation that gravity increases as the separation grows (bearing in mind the proviso that I gave to Peter about the behaviour of an aggregation of particles). Of course, the value of the conceptual model is not in making accurate quantitative predictions, but in providing a basic conceptual foundation upon which further knowledge can be placed (and giving meaning to that further knowledge, which would be meaningless without the conceptual foundation). > > > > > And that's a case of constraining the observation to ONE experiment. > > > > > The two models of the nature of the coin would have other > > > > > implications, OTHER THAN just continuing the coin-toss experiment, > > > > > that would lead to a clearer experimental distinction. The coin-toss > > > > > experiment is experiment E1 that does not clearly distinguish between > > > > > models B and C. So? Now you have to find the place where they make > > > > > clearly distinguishable predictions, and design an experiment E2 that > > > > > will make that discrimination. > > > > > Sometimes that's just not possible. Particularly if the only way the > > > > coin can be tested is by tossing. > > > > I'm sorry, but it's the object of science to FIND the other ways to > > > test a claim. > > > But you've got to accept that sometimes there may be no other > > realistic way of testing. > > WHY? Because, for example, the people of the world are not willing to pay 99% tax for a particle accelerator that circumnavigates the earth, and the hundreds of nuclear power stations going like the clappers that may be required to run the accelerator. Of course I'm being extreme, but the point is that one cannot just say "well science will find a way" to any question of testing. While it is undoubtedly an aim of science to test any claim, some claims are practically, even if not theoretically, untestable. > > There's no point just saying "well science > > must find a way", because in some cases either theory or material > > circumstances may simply rule out any other kind of test. > > No so far. Observing things outside of the "human scale" is very difficult. > > > > > > One example is the lip-service paid to doubt and uncertainty, whereas > > > > > > I can give you Mark who holds that a theory with 95% confidence should > > > > > > not just be accepted by most people, but all people. > > > > > > I don't hold the same conviction about this that he does. People > > > > > CHOOSE what they believe and they CHOOSE the methods by which they > > > > > become convinced of what they should believe. If you CHOOSE NOT to > > > > > adopt the scientific method, that's your prerogative, but it just > > > > > marks what you DO choose to do instead as something other than > > > > > science. Poetry perhaps. > > > > > There are many interesting answers in asking what causes a choice. But > > > > besides that, I think your definition of the scientific method is > > > > completely wrong. As Kuhn puts it (I was just flicking through the > > > > book again), the scientific method has only "pedagogic utility" and > > > > "abstract plausibility". > > > > And now you presume that Kuhn's position is either authoritative, or > > > that scientists would endorse it. > > > No, I'm simply having to draw on authority to rebut your just-so > > statements about the views of physicists collectively, which indeed is > > the very argument you invoke again, by implicitly saying "ah, well > > physicists reject Kuhn's view of science...". > > And here we arrive at an impasse, wherein I say that science is what > the practitioners of science say it is, and you say that science is > what an outside sociologist of scientists says it is. At this point, I > see no point in belaboring it. One can always be absolute about the matter, and say "physics is what I say it is", but that doesn't meaningfully describe the practice of science. And Kuhn wasn't an "outside sociologist". > It is a difference in choice of > authority, and that is a personal decision just as much as CHOOSING to > believe in the value of the scientific method is. "Choice" is always the last refuge of people who have a position that they've failed to justify in its own terms. My old man calls me a conservative (he's always been violently Marxist, although less so now he's on a good pension), but even he saw the funny side the first time he was forced to justify his beliefs in terms of a bald affirmation of his own choice of first principles. > Now that we've concluded that portion of the discussion, I'm wondering > whether you are interested in learning anything about what *science* > says about nature, and in particular how *science* can explain the > relativistic aspects of nature, as investigated by science? > > After all, you came here asking questions about how any of that could > make any sense. And it was plain that you came to this group to ask > *scientists* that question when you could not find a satisfying answer > in the poorly selected materials you had availed yourself of. I see no > value in you asking *scientists* for an explanation, when you offer > the preamble that, fundamentally, you don't trust what scientists > would have to say on the matter. In truth I did have a certain amount of implicit trust in physics before I learned anything about the subject. I got a shock when I actually decided to learn anything about it.
From: Don Stockbauer on 28 Feb 2010 07:02
A constant speed of light in all reference frames? Surely you can't be serious Of course I'm serious. And don't call me "Surely". The new, fresh ones are the best. |