Known physics defeated by simple puzzle?
in [Relativity]
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From: PD on 8 Apr 2010 09:53 On Apr 7, 10:00 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 7 Apr, 23:18, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 7, 5:09 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 7 Apr, 16:59, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 6, 7:27 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > On 6 Apr, 19:44, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Apr 5, 10:03 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > > > You still haven't answered why 'fitting' must be absolute > > > > > > > > Because of the obviousness of the concept. A thing cannot fit and at > > > > > > > the same time not fit, because there is a logical contradiction in the > > > > > > > meaning of those words. And nor can the state be subjective for each > > > > > > > observer, otherwise that isn't materialism (and it isn't causal > > > > > > > either). Or to repeat my earlier analogy, you can't hit a person over > > > > > > > the head with a hammer, and merely daze him *at the same time as* > > > > > > > cracking his skull wide open. > > > > > > > This business about a thing fitting and not fitting being a > > > > > > contradiction... > > > > > > > A penny on the armrest of a plane is at rest in one reference frame > > > > > > and not at rest in another reference frame. Is it not obvious to you > > > > > > that there is a logical contradiction in those claims? > > > > > > No, because *everyone* agrees about how the penny is moving with > > > > > respect to any other object. > > > > > But motion is not defined with respect to another object. It is > > > > defined with respect to a coordinate system, a reference frame. > > > > Then perhaps therein lies the problem. Ultimately, all "reference > > > frames" ultimately anchor to real objects, > > > This is not true. > > I think it is insofar as we're describing physical reality, and not > just talking about geometry on paper. > > > > but "reference frames" are > > > not a physical entities in themselves. As I've said, I have a > > > practical turn of mind, so I'm always careful to understand how > > > abstract concepts relate to something real. > > > This should not lead you to therefore insist that reference frames by > > definition anchor to real objects, whether you want that to be the > > case for practical sensibilities or not. > > I'm *all* about practical sensibilities. This does not give you the right to redefine terms as you wish. I've given you links that discuss the meaning of those terms as they are used in physics. I really don't care that you wish to redefine them so that they seem more practically oriented to you. > > > > > > > > > How does the > > > > > > penny change from being at rest in one frame to not being at rest in > > > > > > another frame, without there being some physical interaction with the > > > > > > penny to cause that change? > > > > > > Because it *doesn't* change from being "at rest" to "not at rest".. > > > > > There is no "change" at all. Both the man on the plane, and the man on > > > > > the ground, agree that the penny is stationary relative to the flyer, > > > > > and moving relative to the man on the ground. The penny does not > > > > > "change" from being stationary to moving. What changes is the object > > > > > to which you are making reference. > > > > > I'm not making reference to any object. The motion of an object is > > > > with regard to a coordinate system, a reference frame. This is basic, > > > > high school physics. > > > > As above. A "reference frame" is still a reference object > > > (linguistically). > > > No, it is not. A reference frame -- again a physics jargon term -- has > > a very clear meaning tha you can look up to correct or augment your > > pedestrian understanding of that word in everyday speech.http://en.wikipedia.org/wiki/Frame_of_referencehttp://www.answers.com... > > That page seemed to be consistent with my understanding. In any event, > I don't think there's anything worth arguing over here - for all > practical purposes, I understand what a frame is. > > > > And what we really mean by "reference frame" is that > > > certain real objects have defined mathematical values for their > > > properties (like defining certain objects to be at rest, and facing a > > > certain direction), and the values of all other objects are calculated > > > in relation to that. > > > > But certainly, there is no need to make reference to a "frame" in > > > order to calculate a "relative speed" between two objects. > > > Yes, there is. > > Is there? (And I'm assuming we're disregarding SR). I'm talking about how nature works. If what you mean by "calculate a relative speed" you intend to produce a result that corresponds to something measurably verifiable, then yes, you do need to include reference to a frame, because a measurable relative speed (or to use a more carefully defined physics term, closing speed) is frame- dependent. Now, if you wish to say, "I can certainly calculate anything I want, regardless whether it has any relevance to anything measurable, and I can certainly choose to do so in a way that is frame- independent," then you are certainly free to do that, just as you are free to suppose everlasting souls and the presence of angels. It's just that there's no scientific interest in doing so. > > > And it turns out that the relative speed between two > > objects as *measured* in different reference frames, is frame- > > dependent. Observationally. Whether you think this is nonsense or not. > > And of course, I do think that. Then you should be encouraged to do some measurements. Again, the fundamental issue is that you seem to insist on believing in the unverifiable reality of certain things because those things make sense to you. And you are more willing to believe in those things than you are in statements that are contrary but confirmed by measurement. As long as you do that, then you are simply favoring faith over evidence, and that has nothing to do with science. PD
From: PD on 8 Apr 2010 10:02 On Apr 7, 10:21 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 8 Apr, 02:39, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 7, 8:21 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 7 Apr, 22:45, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 7, 4:24 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > But you still don't get it. "Fitting" is not a relationship between > > > > > obsever and ladder. It is a relationship between ladder and barn. Why > > > > > on Earth would the observer's presence and circumstances affect the > > > > > fitting of these two objects, that are totally independent of the > > > > > observer? > > > > > To help you understand this, I'd like for you to give me a very > > > > precise definition of what you mean when you say that one object A > > > > will "fit" inside object B, when A and B are relatively moving. > > > > Depending on the quality of your definition, I may probe it with some > > > > additional questions and scenarios to see if it works. > > > > It's relatively straightforward. "Fitting" is when the ladder is of > > > such length that it would be possible to close both doors on the barn, > > > and for the ladder to be contained completely inside. > > > Remember the ladder is moving relative to the barn. > > How does one determine that the ladder is contained completely inside, > > exactly? > > By shutting the doors at the same time, of course. Yes, indeed, this is a crucial ingredient. And of course if the doors were not shut at the same time, then we would not say that the first object fit inside the second object, would we, even though otherwise the observations would be the same? That is, if the front of the ladder were inside the barn (having verified that it passed through one but not the other door) when one door was shut, and the back of the ladder were inside the barn (by the same verification) when the other door was shut, this would be no indication that the ladder fit inside the barn, right? Especially if the doors were not shut at the same time. So, jumping to the chase, if in one reference frame, it is established that the doors were shut at the same time, then the definition of "fitting" inside the barn would have been met, and the ladder would have fit inside the barn in that frame. If in another reference frame, it is established that the doors were not shut at the same time, then the definition of "fitting" inside the barn would not have been met, and the ladder would not have fit inside the barn in that frame. So, you see, it is entirely possible -- and indeed we would be forced to this conclusion -- that the ladder fits in the barn (by virtue of your own definition) in one frame and does not fit in the barn in another frame, provided that we can establish that the timing of the doors being shut depends on the frame. > > > For example, I could shut one door and open it, while the front of the > > ladder is inside the barn, and then I could walk around to the back of > > the barn and shut the other door, while the back of the ladder is > > inside the barn. But by that time, the front of the ladder may have > > struck the first door. Is it still true that the ladder fits inside > > the barn? > > Indeed you could do this, but this would not prove that the ladder > "fitted".
From: PD on 8 Apr 2010 10:10 On Apr 7, 10:32 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 8 Apr, 02:41, PD <thedraperfam...(a)gmail.com> wrote: > > > On Apr 7, 8:21 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 7 Apr, 22:45, PD <thedraperfam...(a)gmail.com> wrote: > > > > > But it does. Closing velocity is also frame dependent. > > > > Suppose you have objects A and B, and you have observers Jack (at rest > > > > relative to A), Larry (at rest relative to B), Mary (moving relative > > > > to both A and B such that A and B have equal speeds relative to Mary), > > > > and Nancy (moving relative to A, B, and Mary). > > > > I must admit I've no clear picture at all about this scenario. > > > Try making a sketch. > > No, what I meant was that there isn't sufficient information for me to > confidently build a mental sketch. You don't describe how anything is > moving relative to anything else, or where anything is positioned > relative to anything else. I did indeed, but you are having difficulty parsing it. If it helps, I will make it concrete for you. Objects A and B are receding from each other at some relative speed v. (Or approaching, but for the sake of concreteness, we choose receding.) Jack is spaced some distance from A but is moving along with it, so that B is receding from Jack but A is neither receding or approaching. Larry is spaced some distance from B but is moving along with it, so that A is receding from Larry but B is neither receding or approaching. Mary is positioned so she is always midway between A and B, so that both are receding from her. Nancy is receding from Mary in the same direction as B but not as fast as B, so that A and B are both receding from Nancy but asymmetrically. What is true is that Jack, Mary, and Nancy will all disagree on the speed of A relative to B. Jack and Larry will agree. This is confirmed by experiment. > And there are six (linguistic) objects in > total positioned and moving in non-specified ways, and also it is not > clear whether the observers should participate as real objects, or > merely oversee as God-observers. Of course, I could make assumptions > about these things, but if it comes to a disagreement, I don't want to > be arguing over a scenario of which there is no shared comprehension. > > > > > Then what will be true > > > > is that the closing speeds between A and B will have the same answers > > > > for Jack and Larry, but that number will be different than the closing > > > > speed between A and B according to Mary, and all of those different > > > > than the one according to Nancy. > > > > No, I reject this. The closing speed between A and B is universal, no > > > matter how the observers move around relative to A and/or B. > > > I don't care whether you reject it or not. It is experimentally the > > case, according to measurements. By what right do you say that > > something is true, despite being counter to measurements? We're back > > to unconfirmable solipsism if you so insist. > > The accusation is that the observations are being misinterpreted, not > that I'm simply pretending the observations don't exist. It's awfully difficult to misinterpret the numerical value of a measurement and whether it agrees with the numerical value of another measurement.
From: PD on 8 Apr 2010 10:18 On Apr 7, 10:43 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 8 Apr, 02:47, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 7, 8:40 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > I doubt that after writing "It cannot fit and not fit at the same > > > > > > time" you really understand this gedanken at all. > > > > > > It depends what you mean by "understand". If you mean "have grasped > > > > > its tenets, and can reason the conclusion from those tenets", then I > > > > > understand it totally. If you mean "accept that length contraction > > > > > really occurs", then the answer is no. And I suspect at this point the > > > > > real problem is not my lack of understanding of the paradox, but your > > > > > lack of understanding of what I mean by "real". > > > > > Real is what can be verified by a measurement. > > > > No it isn't. This is a fundamental difference between us. I dare say > > > there are lots of things that cannot be verified by measurement, but > > > only by inference from other measurements. > > > Not that are of scientific interest, no. > > It certainly *ought* to be of scientific interest. It ought to be of scientific interest that there are lots of things that cannot be verified by experiment but inferred from other measurements? No, I don't think so. That would apply to angels and demons. No, thank you. > > > > > If you believe that reality has certain traits but that those traits > > > > are unverifiable through measurement, because the measurement is > > > > always obscured, then one has to ask on what basis you would believe > > > > reality has those traits in the first place. > > > > Indeed, you would have to ask that. > > > Yes, and appropriately so. I notice you snipped the next line, which I > > here repeat: > > =============================== > > If you then say, "Because > > it makes sense to me that it would," then you have simply slipped into > > subjective solipsism that is divorced from scientific investigation. > > =============================== > > And so there we are. > > Yes. I was simply saying that you are entitled to ask on what basis I > hold that reality has certain traits, and I must be willing to explain > why I hold that. This we agree on, surely? Yes.
From: NoEinstein on 8 Apr 2010 11:19
On Feb 14, 3:42 pm, Ste <ste_ro...(a)hotmail.com> wrote: > Dear Ste: Of course they don't! One source is having the velocity of its light increased to be: V = v + c; while the other is having the velocity of its light REDUCED to be V = v - c. Those two will never match. Read some of the following to better understand my New Physics. NoEinstein Where Angels Fear to Fall http://groups.google.com/group/sci.physics/browse_frm/thread/8152ef3e... Last Nails in Einstein's Coffin http://groups.google.com/group/sci.physics.relativity/browse_frm/thre... Pop Quiz for Science Buffs! http://groups.google.com/group/sci.physics/browse_frm/thread/43f6f316... An Einstein Disproof for Dummies http://groups.google.com/group/sci.physics/browse_thread/thread/f7a63... Another look at Einstein http://groups.google.com/group/sci.physics/browse_frm/thread/41670721... Three Problems for Math and Science http://groups.google.com/group/sci.physics/browse_thread/thread/bb07f30aab43c49c?hl=en Matter from Thin Air http://groups.google.com/group/sci.physics/browse_thread/thread/ee4fe3946dfc0c31/1f1872476bc6ca90?hl=en#1f1872476bc6ca90 Curing Einsteins Disease http://groups.google.com/group/sci.physics/browse_thread/thread/4ff9e866e0d87562/f5f848ad8aba67da?hl=en#f5f848ad8aba67da Replicating NoEinsteins Invalidation of M-M (at sci.math) http://groups.google.com/group/sci.math/browse_thread/thread/d9f9852639d5d9e1/dcb2a1511b7b2603?hl=en&lnk=st&q=#dcb2a1511b7b2603 Cleaning Away Einsteins Mishmash http://groups.google.com/group/sci.physics/browse_thread/thread/5d847a9cb50de7f0/739aef0aee462d26?hl=en&lnk=st&q=#739aef0aee462d26 Dropping Einstein Like a Stone http://groups.google.com/group/sci.physics/browse_thread/thread/989e16c59967db2b?hl=en# Plotting the Curves of Coriolis, Einstein, and NoEinstein (is Copyrighted.) http://groups.google.com/group/sci.physics/browse_thread/thread/713f8a62f17f8274?hl=en# Are Jews Destroying Objectivity in Science? http://groups.google.com/group/sci.physics/browse_thread/thread/d4cbe8182fae7008/b93ba4268d0f33e0?hl=en&lnk=st&q=#b93ba4268d0f33e0 The Gravity of Masses Doesnt Bend Light. http://groups.google.com/group/sci.physics/browse_thread/thread/efb99ab95e498420/cd29d832240f404d?hl=en#cd29d832240f404d KE = 1/2mv^2 is disproved in new falling object impact test. http://groups.google.com/group/sci.physics/browse_thread/thread/51a85ff75de414c2?hl=en&q= Light rays dont travel on ballistic curves. http://groups.google.com/group/sci.physics/browse_thread/thread/c3d7a4e9937ab73e/c7d941d2b2e80002?hl=en#c7d941d2b2e80002 A BLACK HOLE MYTH GETS BUSTED: http://groups.google.com/group/sci.physics/browse_thread/thread/a170212ca4c36218?hl=en# SR Ignored the Significance of the = Sign http://groups.google.com/group/sci.physics/browse_thread/thread/562477d4848ea45a/92bccf5550412817?hl=en#92bccf5550412817 Eleaticus confirms that SR has been destroyed! http://groups.google.com/group/sci.math/browse_thread/thread/c3cdedf38e749bfd/0451e93207ee475a?hl=en#0451e93207ee475a NoEinstein Finds Yet Another Reason Why SR Bites-the-Dust! http://groups.google.com/group/sci.physics/browse_thread/thread/a3a12d4d732435f2/737ef57bf0ed3849?hl=en#737ef57bf0ed3849 NoEinstein Gives the History & Rationale for Disproving Einstein http://groups.google.com/group/sci.physics/browse_thread/thread/81046d3d070cffe4/f1d7fbe994f569f7?hl=en#f1d7fbe994f569f7 There is no "pull" of gravity, only the PUSH of flowing ether! http://groups.google.com/group/sci.physics/browse_thread/thread/a8c26d2eb535ab8/efdbea7b0272072f?hl=en& > > No takers for this simple question then? > > Consider this setup: > > S1 D2 > > D1 S2 > > We've got sources S1 and S2, paired with detectors D1 and D2. They're > all mechanically connected, so that a movement in one of them > produces > a movement in all the others - in other words, their relative > distances are always maintained. Each source is transmitting a > regular > pulse of light to its counterpart detector (so S1 is transmitting to > D1, etc.), and both sources are transmitting simultaneously with each > other. > > Now, we calculate that a pulse has just been emitted from both > sources, and we suddenly accelerate the whole setup "upwards" (i.e. > relative to how it's oriented on the page now) to near the speed of > light, and we complete this acceleration before the signals reach > either detector. > > Now, do both detectors *still* receive their signals simultaneously, > or does one receive its signal before the other? And are the signals > identical, or do they suffer from Doppler shifting, etc? |