A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
|
From: PD on 1 Mar 2010 11:12 On Feb 28, 2:37 am, Ste <ste_ro...(a)hotmail.com> wrote: > 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. And so law is a religion? And medicine is a religion? Not in my understanding of the word religion. > Music > and architecture can undoubtedly be put to ideological uses, and are > invariably informed by the predominant ideology. That's not what I asked. Is architecture a religion? > I'm not so sure about > plumbing however. It seems to satisfy the same criteria by which you were calling science a religion. > > > 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. You said that plumbing and architecture make no claims about the fundamental nature of the universe, implying that this somehow excuses them where physics should not be. > > > 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. Then you'll have to be precise about your meaning of the word "religion" and therefore how it is that science satisfies it. > > > > > > > > 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. Exactly. > 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). In a manner that is so loose that it does not distinguish itself from other models. Thereby being useless. Part of the value of a scientific theory is that it lends the ability to make predictions with remarkable *precision* about the outcome to be expected from certain circumstances. It is this value that allows those principles to be turned over to engineers for the construction of practical devices. I'm sure you can see where a model that is qualitatively appealing for the "everyman" to understand what is going on in some loose sense, would be completely useless for this purpose. What I'm telling you is that scientific theories offer BOTH precision for practical deployment AND physical intuition (though that might conflict with some preconceived notions drawn from limited experience). > > > > > > > > > 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. And again, your imagination is somewhat limited. The aim of the physicist is to find ways that theories can be tested WITHOUT demanding that 99% of the world economy be devoted to the test. So far, scientists have been able to do that, generating experimental designs that are considered value-returners on the investment, and which make clear distinctions between models. > > > > 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. Not really. It just takes considerable imagination and careful effort. You'd be amazed what information can be gleaned. > > > > > > > > > > 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. I disagree. You seem to be asking for proof that a particular mode of investigation is obviously (to everyone) the best mode of investigation for that domain. You also seem to have it in your head that science conveys the claim that it has accomplished that. It hasn't and it makes no such claim. Democracy cannot be *proven* beyond doubt to be the best sociopolitical system for humans, nor is it rational to demand that it do so. Same goes for any system of justice that you choose, and for any economic strategy. This is not to be taken as a failure of those systems to justify themselves in their own terms. You seem to have an expectation of science that it "prove itself" where no other avenue of knowledge-gathering is expected to do the same. Why is that? > 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. In that case, I'm certainly glad that you've decided to investigate it more seriously. Now you can dispense with your previously unexamined trust, and you can find out more clearly what basis of trust you should hold, based on better information about how science works and why it believes what it believes. However, the implicit challenge "convince me" is going to go unsatisfied, as science bears no responsibility for that whatsoever, any more than any other field is expected to.
From: PD on 1 Mar 2010 11:25 On Feb 28, 11:08 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 28 Feb, 07:07, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > On 27 Feb, 15:44, PD <thedraperfam...(a)gmail.com> wrote: > > > > 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. > > Not true. > > > 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. > > Well I was replying to Paul. > > > 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. > > String theory is *not* falsifiable. That's correct, in its present form. That's why it's not really a theory yet. > Dark matter is resistent to > falsification, because it "does not interact except through gravity > and inertia". This turns out to be a wrong statement, and I don't know where you got it. CDMS is an example of an experiment that is designed to falsify (or verify) dark matter by looking for nongravitational, noninertial signatures. > Both Newton and Galileo were falsified a number of times > by their contemporaries, and they were forced to revise (of course, > this was before Popper). I don't understand how this makes the output of Newton and Galileo unfalsifiable. You've just demonstrate that their initial attempts WERE falsifiable, as is the revised model which survived them. > We've dealt with evolution elsewhere. > Rational choice theory is either falsified when it makes express > claims as to what people want, or it becomes unfalsifiable when it > makes no express claim as to what people want.
From: PD on 1 Mar 2010 11:27 On Feb 28, 11:29 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 28 Feb, 16:33, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > On Feb 28, 1:54 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > 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 are correct about E1 and E2 being simultaneous to all observers on > > the line despite their motion relative to other observers on the > > line. The statement about spatially seperated events is about > > seperation along the axis of travel. In the train experient A and B > > are on the tracks, which we call the x axis. You have E1 and E2 off > > to the sides of the tracks on the y axis, which isn't normally > > considered in the train experiment. > > This is called "revisionism", Bruce. The statement was not "about > seperation along the axis of travel". It was about "what is > simultaneous in one frame is not simultaneous in another" And I concede the point that the statement so simply stated is incorrect. >, and "Ste, > you are an idiot who knows nothing about SR". > > Apparently, both statements have been falsified. Hehehe. Next!
From: PD on 1 Mar 2010 11:28 On Feb 28, 11:33 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 28 Feb, 17:20, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > On Feb 27, 8:42 am, Jerry <Cephalobus_alie...(a)comcast.net> wrote: > > > > You should give Ste a specific book recommendation: > > > > Spacetime Physics, by Taylor and Wheeler > > > > The second edition can generally be picked up used for about $25. > > > The first edition is frequently found on eBay with a "Buy it now" > > > price of $5 to $10. > > > [...] > > > IMO that book stinks for explaining SR. It presents the math but > > doesn't provide the underlying reason for the math. > > Haha! And these pillocks wonder why I won't go out and spend a grand > in money and 6 months of time, working through their extensive reading > lists! Ah, so you're looking for a reference that is GUARANTEED by universal acclamation to satisfy your learning needs? > > > Another thing I don't like is their constant repetition of how things > > aren't what we expect because we aren't used to dealing with the > > speeds involved. That's BS. > > Yes, I get a bit tired of that even on this newsgroup.
From: mpalenik on 1 Mar 2010 12:14
On Mar 1, 8:51 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > >> > Stop making me laugh Peter. I have surely forgotten more about > >> > evolution than you'll ever know, because you typify arrogance and > >> > closed-mindedness. > > >> I laughed when you first said what you thought evolution was about. > > >> You said it explained the origon of life (amongst other things). > > >> Evolution says nothing about that at all. > > > Guffaw! "Evolution says nothing about the origin of life at all". I > > wonder if Dirk van de Moortel would like that one for his "immortal > > fumbles" page. > > Interesting that you have forgotten more about evolution than I will ever > know, because I can't actually recall Darwin's theory of evolution as saying > anything at all about the origins of life. > > What do you think it says about the origins of life, exactly? > > (See. Like I said. You know even less about evolution than you do about SR.) Peter, here you go: http://en.wikipedia.org/wiki/Abiogenesis =/= evolution "In the natural sciences, abiogenesis (pronounced /eɪËbaɪ.ɵËdÊÉnɨsɪs/, ay-BYE-oh-JEN-É-siss) or biopoesis is the theory of how life on Earth could have arisen from inanimate matter. It should not be confused with evolution,. . ." |