Known physics defeated by simple puzzle?
in [Relativity]
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From: PD on 7 Apr 2010 18:08 On Apr 7, 4:57 pm, Ste <ste_ro...(a)hotmail.com> wrote: > On 7 Apr, 16:57, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 6, 7:12 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > We've had this one before Paul. No experiment of this kind (i.e. > > > trying to confine objects moving at relativistic speeds) has ever been > > > performed. I even gave sources last time for this statement. > > > That is simply not true. At RHIC, for example, where nucleus-nucleus > > collisions are done, the density of the quarks and gluons goes up > > precisely because of this Lorentz contraction. The nucleus is > > "squashed" and the density goes up. This is essential to both the > > design and the operation of this multimillion dollar facility. > > > Furthermore, secondary particle emission from particle collisions have > > been done in both fixed target and collider facilities. Under both > > circumstances, relativity predicts the uniform distribution of those > > secondaries according to a variable called rapidity. In experiments, > > calorimeters are then arranged around the collision point and > > segmented in regular rapidity bins. Naturally, because the two > > experiments are viewing the same collisions from two different > > reference frames, the length binning for equal rapidity bins is > > considerably different, precisely because of Lorentz contraction. > > Thus, the distribution by rapidity, as shown by the particle deposits > > in the calorimeter, is an indirect but definitive check on Lorentz > > contraction. Experimentally, the match-up is exquisite. > > > It's unfortunate that your web references are not accurate on this > > score, and have led you to the impression that Lorentz contraction is > > all hypothetical and without experimental support. I will just > > attribute this to the lack of depth of experimental information you've > > been able to lay your hands on. > > I really don't understand enough about how these machines work, and > almost certainly never will, so it's pointless me attempting to > reconcile what you say. All I will repeat is that a number of > scientific sources, including a number of published scientific papers, > have insisted that there has been no direct measurement of a physical > length contraction. "Direct" is perhaps the key word. It is unfortunate that those papers led you to the conclusion that it has not been experimentally verified at all. I take no responsibility for confusion on your part that stems from the limited selection of material you choose to read. > And indeed, whether there is experimental evidence > or not, I still have not heard any compelling *explanation* for how > two objects could each physically contract to a smaller size relative > to the other. The definition of length is completely reliant on establishing simultaneity. Since simultaneity is frame-dependent, it is no wonder that length is frame-dependent. > > > > But as I've said previously, even if this *is* what we would "see", > > > seeing is not necessarily believing. > > > And this is what I'm telling you is a bad policy in science. If > > experiment comes in conflict with common sense -- that is, if what you > > see is in conflict with what you understand -- then it is common sense > > that should properly give way. I understand fully that you say you > > just don't operate that way, and don't see why you should have to. > > That's just absurd Paul. Insofar as you're contradicting that "seeing > is not necessarily believing", your prescriptions would be a recipe > for the trite regurgitation of observations, without any deeper > understanding at all. If all we ever had to do in science was observe, > and not interpret, then one wonders why it has taken so long to get > this far. You have always maintained that there are always multiple interpretations, multiple explanations that would apply to the same set of data. While this may be so in some limited sense, it is the burden of the proposer of an interpretation to demonstrate that it is the case with his own, complete with quantitative support. Furthermore, it has ALWAYS been the case that there can be isolated a place where two different interpretations make DIFFERENT predictions about what will be observed under certain circumstances. That, then, is the place where the next experimental test is focused. This is GUARANTEED to eliminate one or the other of the interpretations, and this is how scientific progress is made.
From: Ste on 7 Apr 2010 18:09 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, 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. > > > 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). 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. And the point is that, those relative speeds between any two objects are the same in all frames, even though the speed of any one object relative to the frame is not.
From: PD on 7 Apr 2010 18:18 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. > 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. > > > > > 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_reference http://www.answers.com/topic/frame-of-reference > 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. 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 the > point is that, those relative speeds between any two objects are the > same in all frames, even though the speed of any one object relative > to the frame is not.
From: Sue... on 7 Apr 2010 18:29 On Apr 7, 6:18 pm, 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. > > > 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. Remember... You have given up LET for SR so rulers are not dependent on inertial frames. Minkowski Space http://www.bartleby.com/173/17.html I can tape a metre stick to a gun barrel and that is a proper clock. K.E. = 1/2 mv^2 The hijackers of the world would be interested to hear from you which inertial frame most slows the clock and weakens the lawmam's bullet. > > > > > > > > > > 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/topic/frame-of-reference > > > 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. 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 the > > point is that, those relative speeds between any two objects are the > > same in all frames, even though the speed of any one object relative > > to the frame is not. > >
From: paparios on 7 Apr 2010 19:13
On 7 abr, 17:39, Ste <ste_ro...(a)hotmail.com> wrote: > On 7 Apr, 20:57, "papar...(a)gmail.com" <papar...(a)gmail.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". > For sure you do not know what real is in physics. > > We all understand > > that. You don't know what you are talking about and it shows. > > When you build a model of the world such as Special Relativity, you > > consider some building blocks (the two postulates) and continue from > > there. You are really not interested in following that route, > > You're right. I'm not interested in merely reasoning from the first > principles of a particular theory, and then dusting off my hands and > patting myself on the back. > > I'm interested in seeing how this theory actually applies to the real > world, and how the conclusions of the theory are to be interpreted in > practice. For example, how "length contraction" is to be explained as > a matter of practical reality, and not just accepted at face value > "because the theory predicts it". > Again that is whining without any reason but you unwillingness to learn how the model was developed. We do not have time to teach you that and, besides, this is not the best media to teach. I recommend you the first 20 pages of the second volume of Landau and Lifshitz (The Classical Theory of Fields) which goes from A to Z with the minimum possible of mathematics requirements. > Like I said, the equations of audio Doppler predict that the received > frequency will change depending on your velocity to the source. But it > does not *explain* why this happens, and nor does it state whether the > source frequency changes or not. All it describes is what you will > observe, without *any* physical explanation at all. One must look > *beyond* the mere maths of audio Doppler, in order to *physically > explain* the effect. > On the contrary, the mathematical model on that case does explain what IT IS OBSERVED IN NATURE. You don't ask why the Earth, together with the rest of the planets, move in a determined direction and not in the opposite direction. Classical mechanics models are good enough to explain the observation and make possible to move around the Solar system. > > and you > > are just picking some so called "paradoxes" or in your language > > "puzzles" to try to attack the model. > > The truth is that I'm not "attacking" SR - in the sense of saying that > it is inapplicable to reality. I'm actually arguing about *how* it > applies to reality. Actually is quite clear, after over 2000 posts, in these nonsenses of yours, that you do not really understand most of the language of science. So talking with you is like talking with a person speaking in another language and, since you are not willing to even use the terminology (which implies studying way beyond you level of expertise) this whole exercise is useless. Miguel Rios |