Known physics defeated by simple puzzle?
in [Relativity]
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From: Sue... on 5 Apr 2010 07:10 On Apr 5, 1:19 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > news:b0d31ce6-409d-4e59-9940-e3b780c70a95(a)k19g2000yqn.googlegroups.com... > On Apr 4, 8:26 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > >news:8185f44e-a0bb-4c3d-906e-117c1616aaf6(a)q15g2000yqj.googlegroups.com.... > > On Apr 4, 10:28 am, "Peter Webb" > > > > > or whether the relativistic speeds cause a sort of > > > > lensing effect (i.e. like putting a prism in front of one's eyes, the > > > > "contraction" affects only the person with the prism in front of their > > > > eyes) that makes everything *appear* contracted, but there is actually > > > > no measurable change at all in the rest of the universe. > > > ================== > > > > No, its not an optical illusion, for the 8 billionth time. > > > > The travelling twin really is younger. > > > > The ladder really does fit inside the barn. > > > In spite of recent cautions not to appeal to authority, > > I think you will find some important contributors > > to Einstein's relativity are diametrically opposed > > to you view. > > > ________________________________________ > > OK, name one physicist who believes that the travelling twin would not > > return younger. > ==================== > Nearly all and you just snipped the reason why. > > _____________________________________ > Name one. "A man who carries a cat by the tail learns something he can learn in no other way." --Mark Twain << [C.S.] Unnikrishnans arguments suggest that the resolution of the twin paradox as presented by the relativists is devoid of any rationality. He is in favour of the re- jection of the STR, which is however not unique. Many others also equally share the same conviction with Unnikrishnan. Grøn2 has tried to counter Unnikrishnan with the consideration of the STR. But, unfortunately, he has evaded the central question relating to the problem. We may now clarify here the central question of the twin paradox in the fol- lowing simple examples. (a) The STR predicts that the lifespan of radioactive particles increases with velocity, which has been verified by ex- periments when the observer with his measuring apparatus is at rest on the sur- face of the earth and the radioactive particles moves with respect to it. To establish the validity of the STR, Grøn has to show that similar results are confirmed by ex- periments when the radioactive particles are stationary while the observer with his measuring apparatus steadily moves. In the absence of such a clear-cut experi- ment, Grøns analysis is meaningless. (b) Similarly, the STR predicts trans- verse Doppler effect (time-dilation effect) for steadily moving radiating dipoles. To establish the validity of the STR, similar results should be confirmed by experi- ments when the radiating dipoles are at rest on earth, while the observer moves steadily. We expect that experiments with latest techniques will not detect any of these phenomena when the radiating dipoles are at rest on earth, while the observer with his measuring apparatus moves. However, we maintain that physics should be based on the available experi- mental data and not on data which could never be verified, nor on data which are expected to be verified later. Therefore, Grøns discussion is a matter of philoso- phy, not of physics. Time dilation could easily be ex- plained from classical electrodynamics as the natural increment of the period of an electromagnetic event due to motion, time remaining the same to all observers according to classical physics. The gist of this explanation is given below. When a radiating electric dipole moves steadily on earth, the electric and the in- duced magnetic fields inside the dipole change according to the classical elec- trodynamics of Heaviside and, thereby, all electrodynamic phenomena inside the steadily moving dipole also change, which at once destroys the relativistic time- dilation concept.>> --KABERI HAZRA On the resolutions of the twin paradox www.ias.ac.in/currsci/sep252008/706.pdf ==================================== C. S. UNNIKRISHNAN Gravitation Group, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India e-mail: un... =============== Sue...
From: Inertial on 5 Apr 2010 07:19 "Sue..." <suzysewnshow(a)yahoo.com.au> wrote in message news:ed04e40a-c559-480f-872c-bc14932105b4(a)z6g2000yqz.googlegroups.com... > On Apr 5, 1:19 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: >> "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message >> >> news:b0d31ce6-409d-4e59-9940-e3b780c70a95(a)k19g2000yqn.googlegroups.com... >> On Apr 4, 8:26 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> >> wrote: >> >> >> >> > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message >> >> >news:8185f44e-a0bb-4c3d-906e-117c1616aaf6(a)q15g2000yqj.googlegroups.com... >> > On Apr 4, 10:28 am, "Peter Webb" >> >> > > > or whether the relativistic speeds cause a sort of >> > > > lensing effect (i.e. like putting a prism in front of one's eyes, >> > > > the >> > > > "contraction" affects only the person with the prism in front of >> > > > their >> > > > eyes) that makes everything *appear* contracted, but there is >> > > > actually >> > > > no measurable change at all in the rest of the universe. >> >> > ================== >> >> > > No, its not an optical illusion, for the 8 billionth time. >> >> > > The travelling twin really is younger. >> >> > > The ladder really does fit inside the barn. >> >> > In spite of recent cautions not to appeal to authority, >> > I think you will find some important contributors >> > to Einstein's relativity are diametrically opposed >> > to you view. >> >> > ________________________________________ >> > OK, name one physicist who believes that the travelling twin would not >> > return younger. >> > > ==================== >> Nearly all and you just snipped the reason why. >> >> _____________________________________ >> Name one. > > > "A man who carries a cat by the tail learns something > he can learn in no other way." > --Mark Twain > > > << [C.S.] Unnikrishnan�s arguments suggest > that the resolution of the twin paradox as > presented by the relativists is devoid of > any rationality. He is in favour of the re- > jection of the STR, which is however not > unique. Many others also equally share > the same conviction with Unnikrishnan. > Gr�n2 has tried to counter Unnikrishnan > with the consideration of the STR. But, > unfortunately, he has evaded the central > question relating to the problem. > We may now clarify here the central > question of the twin paradox in the fol- > lowing simple examples. > (a) The STR predicts that the lifespan > of radioactive particles increases with > velocity, which has been verified by ex- > periments when the observer with his > measuring apparatus is at rest on the sur- > face of the earth and the radioactive particles > moves with respect to it. To establish the > validity of the STR, Gr�n has to show > that similar results are confirmed by ex- > periments when the radioactive particles > are stationary while the observer with his > measuring apparatus steadily moves. In > the absence of such a clear-cut experi- > ment, Gr�n�s analysis is meaningless. > (b) Similarly, the STR predicts trans- > verse Doppler effect (time-dilation effect) > for steadily moving radiating dipoles. To > establish the validity of the STR, similar > results should be confirmed by experi- > ments when the radiating dipoles are at > rest on earth, while the observer moves > steadily. > We expect that experiments with latest > techniques will not detect any of these > phenomena when the radiating dipoles > are at rest on earth, while the observer > with his measuring apparatus moves. > However, we maintain that physics > should be based on the available experi- > mental data and not on data which could > never be verified, nor on data which are > expected to be verified later. Therefore, > Gr�n�s discussion is a matter of philoso- > phy, not of physics. > �Time dilation� could easily be ex- > plained from classical electrodynamics > as the natural increment of the period of > an electromagnetic event due to motion, > time remaining the same to all observers > according to classical physics. The gist > of this explanation is given below. > When a radiating electric dipole moves > steadily on earth, the electric and the in- > duced magnetic fields inside the dipole > change according to the classical elec- > trodynamics of Heaviside and, thereby, > all electrodynamic phenomena inside the > steadily moving dipole also change, which > at once destroys the relativistic time- > dilation concept.>> > --KABERI HAZRA > On the resolutions of the twin paradox > www.ias.ac.in/currsci/sep252008/706.pdf > > > ==================================== > > C. S. UNNIKRISHNAN > Gravitation Group, > Tata Institute of Fundamental Research, > Homi Bhabha Road, > Mumbai 400 005, India > e-mail: un... > > > =============== > > Sue... An aetherist.
From: Peter Webb on 5 Apr 2010 09:54 "Sue..." <suzysewnshow(a)yahoo.com.au> wrote in message news:ed04e40a-c559-480f-872c-bc14932105b4(a)z6g2000yqz.googlegroups.com... On Apr 5, 1:19 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > news:b0d31ce6-409d-4e59-9940-e3b780c70a95(a)k19g2000yqn.googlegroups.com... > On Apr 4, 8:26 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > >news:8185f44e-a0bb-4c3d-906e-117c1616aaf6(a)q15g2000yqj.googlegroups.com... > > On Apr 4, 10:28 am, "Peter Webb" > > > > > or whether the relativistic speeds cause a sort of > > > > lensing effect (i.e. like putting a prism in front of one's eyes, > > > > the > > > > "contraction" affects only the person with the prism in front of > > > > their > > > > eyes) that makes everything *appear* contracted, but there is > > > > actually > > > > no measurable change at all in the rest of the universe. > > > ================== > > > > No, its not an optical illusion, for the 8 billionth time. > > > > The travelling twin really is younger. > > > > The ladder really does fit inside the barn. > > > In spite of recent cautions not to appeal to authority, > > I think you will find some important contributors > > to Einstein's relativity are diametrically opposed > > to you view. > > > ________________________________________ > > OK, name one physicist who believes that the travelling twin would not > > return younger. > ==================== > Nearly all and you just snipped the reason why. > > _____________________________________ > Name one. "A man who carries a cat by the tail learns something he can learn in no other way." --Mark Twain << [C.S.] Unnikrishnan�s arguments suggest that the resolution of the twin paradox ... ________________________________ I might point out that neither Unnikrishna or Gron argue that the travelling twin would not be younger. On the contrary, they accept this is true, but provide different explanations for it. You will not find a single physicist who believes that the travelling twin will not return younger, as this has been directly tested on many occasions. It is an observed fact. Hence I repeat my challenge: "OK, name one physicist who believes that the travelling twin would not return younger."
From: Ste on 5 Apr 2010 11:46 On 5 Apr, 01:38, "Inertial" <relativ...(a)rest.com> wrote: > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > Incidentally, this book (which was a link from Wikipedia) confirms my > > statement that GR is how the paradox was apparently resolved (at least > > by Einstein and a few others): > >http://books.google.com/books?id=vuTXBPvswOwC&pg=PA165#v=onepage&q=&f... > > You CAN use GR .. which is a superset of SR. But SR 'solves' it as well As I say, that's not how I understand it, and the written evidence elsewhere (for example, in the link I've just provided) suggests that even Einstein clearly felt that GR was necessary to explain it. At the very least, you can see that I'm subject to contradictory evidence here, and you can understand why I don't take your statement here at face value. > >> > but > >> > as I understand it, you need GR to account for acceleration (in other > >> > words, it's outside the scope of this discussion). > > >> Wrong .. you've had that told to you many times. SR handles acceleration > >> just fine > > > As I say, the information I have suggests that GR is necessary to > > account for the (absolute) acceleration, > > That is wrong > > > whereas SR treats > > acceleration merely as a change of relative velocity > > It is a change in velocity Yes, but do you mean a relative change of velocity or (shall we say) an "absolute" change of velocity? Remember, relative velocity can change without absolute acceleration. Indeed, a bullet that flies past your ear undergoes a dramatic change of relative velocity to you as it passes (it approaches and then recedes), but neither you or the bullet undergo any application of force to cause that relative change of velocity > > (which may or may > > not involve "real" acceleration - the kind that would be registered on > > an accelerometer). > > If it is acceleration, it would register on an accelerometer > > You are making distinctions where there are none No I'm not. Clearly relative velocities can change with or without an application of force - as I understand the twins paradox, it is the application of force to the travelling twin that causes the asymmetry of aging. > >> >> The ladder really does fit inside the barn. > > >> > But then it must fit inside the barn from *all* frames, > > >> Why? > > > Because "fitting" and "not fitting" are two mutually exclusive states. > > You haven't answered the question I think I have. I've insisted that the two states are mutually exclusive, and I've elaborated on it below. > >> It doesn't have the same speed in all frames. It doesn't have the > >> same momentum in all frames. It doesn't have the same kinetic energy in > >> all > >> frames. Why must it have the same length? > > > Because the notion of "speed", "energy" and "momentum" are all > > inherently relative concepts. > > As are length and duration I don't see how length can be inherently relative (although its appearance certainly can be, as I illustrated in a previous post). > > If I hit someone over the head with a > > hammer, then the force applied to the skull depends on the relative > > speed of the hammer and the skull. But all observers agree about the > > force of the impact between the hammer and the skull - in other words, > > I do not crack his skull wide open according to some observers, and > > merely daze him according to others. > > And that is the same in SR .. either something happens or it doesn't Indeed, so the ladder either fits or it doesn't! You can't say "it fits according to some observers", because that is absurd as saying "he was merely dazed according to some observers". > > The same is true of this ladder problem. If the ladder contracts, then > > it will fit in the barn, and if it doesn't contract then it won't fit > > - but it cannot contract at the same time as not contracting, or fit > > at the same time as not fitting. > > Wrong > > > However, it can *appear* to do so by careful timing of the doors and > > careful placement of the observer, and so naturally I'm saying to > > myself "this must be what you mean". > > No .. it really fits. You really need to understand the scenario before > drawing conclusions from it I do understand the scenario. It is explained by the apparent timing of the doors. > >> > including the > >> > rest frame of the ladder. And I know that is not what SR predicts. > > >> But you are insisting that only things that are frame independent are > >> real > >> (which rules out a large amount of what we measure and work with in > >> physics). > > > No, I'm insisting that observations/changes can have a "real" basis, > > or an "apparent" basis, at least for the purposes of this argument . > > So velocity, momentum etc do not have a real basis, according to your logic I didn't say that. > > And indeed, a lot of the things you may be working with and measuring > > in physics are "apparent" and not "real". And I will state the > > definition of "apparent": "appearing as such but not necessarily so". > > So velocity, momentum etc do not have a real basis, according to your logic I didn't say that. > > So when we talk of "clocks slowing down", we need to be clear about > > whether we're talking about the clock *appearing* to slow down (but > > continuing to tick at the normal rate), or whether it is *really* > > slowed down. (More on this below.) > > Depends on what you mean by 'real'. Your usage is problematic, as you are > excluding a wealth of things that are considered 'real' by reasonable people > and physics The problem, once again, is that this discussion is degenerating into a discussion between philosophers who share no common language. > >> So if you stand on the the highway and a car travelling at 100km/h runs > >> into > >> you, you don't need to worry, because it isn't really travelling fast > >> (velocity isn't real by your standard), and doesn't really have a large > >> amount of momentum and kinetic energy (momentum and kinetic energy isn't > >> real by your standard) that it imparts into you and your death isn't > >> real. > > > But I will be apparently dead. ;) > > So you die from apparent causes and not real ones. No, I was just joking, as indicated by wink and the follow-on "seriously though"... > > Seriously though, I didn't say velocity was "not real", > > Yes .. you did .. when you said something is only real if it is the same for > all observers Yes, indeed. And the hammer hits the skull with the same velocity, the same force, and with the same effect, according to all observers. I really don't see what is difficult about this. > > but it is a > > relative concept (that is, it is an interaction of two objects, not a > > property of one object; and it is still invariant across all frames, > > in that the car hits the person with the same force, and the same > > effect, no matter where you look at it from). > > Just like a pole fitting in a barn .. that is an interaction of two objects Well, you can either think of the property of "fitting" as a property of one object (i.e. the entire ladder and barn setup). Or, you can think of it as an interaction between two objects that all observers agree about (and which is not relative, like the skull-cracking scenario). There is no room, as it were, in physics to talk about an interaction between two objects that all observers don't agree on. > > Also, I'd be interested to return to a discussion > > I'm sure you would, as your current postition on 'real' has been shown as > rather silly. Because as I told you, I didn't want to get into a philosopher's discussion about the precise meaning of the words. I wanted to work with what I see as their common sense and everyday, if slightly vague, meaning, and actually get some meaningful communication between us. > > about my "speaking > > clock" - I had previously said that it ticked loudly, but let's make > > it even more easy to imagine by saying that it consists of just black > > box with an audio speaker, and it "speaks" the time out loud every > > second. Do you not accept that the faster you move away from the > > speaking clock, the slower the clock appears to go? > > That's an audio illusion (or optical if you are reading the time) due to > delays in signal. > > That is NOT what happens in SR when we say clocks are measured as running > slow. Well, do you accept that this is at least *one* of the causes of why a clock will appear to run slow? > You really need to understand what SR actually says before making > conclusions about it. That's what we're trying to do here.
From: Sue... on 5 Apr 2010 12:06
On Apr 5, 9:54 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > news:ed04e40a-c559-480f-872c-bc14932105b4(a)z6g2000yqz.googlegroups.com... > On Apr 5, 1:19 am, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > wrote: > > > > > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > >news:b0d31ce6-409d-4e59-9940-e3b780c70a95(a)k19g2000yqn.googlegroups.com.... > > On Apr 4, 8:26 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > wrote: > > > > "Sue..." <suzysewns...(a)yahoo.com.au> wrote in message > > > >news:8185f44e-a0bb-4c3d-906e-117c1616aaf6(a)q15g2000yqj.googlegroups.com.... > > > On Apr 4, 10:28 am, "Peter Webb" > > > > > > or whether the relativistic speeds cause a sort of > > > > > lensing effect (i.e. like putting a prism in front of one's eyes, > > > > > the > > > > > "contraction" affects only the person with the prism in front of > > > > > their > > > > > eyes) that makes everything *appear* contracted, but there is > > > > > actually > > > > > no measurable change at all in the rest of the universe. > > > > ================== > > > > > No, its not an optical illusion, for the 8 billionth time. > > > > > The travelling twin really is younger. > > > > > The ladder really does fit inside the barn. > > > > In spite of recent cautions not to appeal to authority, > > > I think you will find some important contributors > > > to Einstein's relativity are diametrically opposed > > > to you view. > > > > ________________________________________ > > > OK, name one physicist who believes that the travelling twin would not > > > return younger. > > ==================== > > > Nearly all and you just snipped the reason why. > > > _____________________________________ > > Name one. > > "A man who carries a cat by the tail learns something > he can learn in no other way." > --Mark Twain > > << [C.S.] Unnikrishnans arguments suggest > that the resolution of the twin paradox ... > > ________________________________ > I might point out that neither Unnikrishna or Gron argue that the travelling > twin would not be younger. On the contrary, they accept this is true, but > provide different explanations for it. > > You will not find a single physicist who believes that the travelling twin > will not return younger, as this has been directly tested on many occasions. > It is an observed fact. > > Hence I repeat my challenge: "OK, name one physicist who believes that the > travelling twin would not return younger." Scientists don't state their "beliefs". They work with experimental evidence and the evidence that would support your position is faulty. Consider a course in remedial reading. << [C.S.] Unnikrishnans arguments suggest that the resolution of the twin paradox as presented by the relativists is devoid of any rationality. He is in favour of the re- jection of the STR, which is however not unique. Many others also equally share the same conviction with Unnikrishnan. Grøn2 has tried to counter Unnikrishnan with the consideration of the STR. But, unfortunately, he has evaded the central question relating to the problem. We may now clarify here the central question of the twin paradox in the fol- lowing simple examples. (a) The STR predicts that the lifespan of radioactive particles increases with velocity, which has been verified by ex- periments when the observer with his measuring apparatus is at rest on the sur- face of the earth and the radioactive particles moves with respect to it. To establish the validity of the STR, Grøn has to show that similar results are confirmed by ex- periments when the radioactive particles are stationary while the observer with his measuring apparatus steadily moves. In the absence of such a clear-cut experi- ment, Grøns analysis is meaningless. (b) Similarly, the STR predicts trans- verse Doppler effect (time-dilation effect) for steadily moving radiating dipoles. To establish the validity of the STR, similar results should be confirmed by experi- ments when the radiating dipoles are at rest on earth, while the observer moves steadily. We expect that experiments with latest techniques will not detect any of these phenomena when the radiating dipoles are at rest on earth, while the observer with his measuring apparatus moves. However, we maintain that physics should be based on the available experi- mental data and not on data which could never be verified, nor on data which are expected to be verified later. Therefore, Grøns discussion is a matter of philoso- phy, not of physics. Time dilation could easily be ex- plained from classical electrodynamics as the natural increment of the period of an electromagnetic event due to motion, time remaining the same to all observers according to classical physics. The gist of this explanation is given below. When a radiating electric dipole moves steadily on earth, the electric and the in- duced magnetic fields inside the dipole change according to the classical elec- trodynamics of Heaviside and, thereby, all electrodynamic phenomena inside the steadily moving dipole also change, which at once destroys the relativistic time- dilation concept.>> --KABERI HAZRA On the resolutions of the twin paradox http://www.ias.ac.in/currsci/sep252008/706.pdf ==================================== C. S. UNNIKRISHNAN Gravitation Group, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India e-mail: un... =============== Sue... |