xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) Thanks, imatfaal. In the OP I had thought that two different points at the same angular velocity, where the travellers can see each other, creates an impossible situation. However; this thread is now at the stage where some reasons are being given to explain the nature of a relative time-dilation. Namely; change in frequency of wave vector. No, it does NOT create an "impossible situation" since this is exactly the situation solved in the case of GPS. Actually, GPS solves an even more complicated situation, where there is difference in the angular speed between the two "travelers" as you call them. GPS works EVEN when there is radial motion between the two travelers. I'll ask you one more time: do you have GPS in your car? If you do, does it work? This is certainly not my intention. You can prove that this is the case by answering the two questions I asked you. Edited July 28, 2014 by xyzt Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 No, it does NOT create an "impossible situation" since this is exactly the situation solved in the case of GPS. Actually, GPS solves an even more complicated situation, where there is difference in the angular speed between the two "travelers" as you call them. GPS works EVEN when there is radial motion between the two travelers. I'll ask you one more time: do you have GPS in your car? If you do, does it work? No, I don't think it is. In GPS the clock is changed on the satellite, but the signal frequency is not the clock frequency, and the question is about the signal frequency. We know the signal changes because of the Pound-Rebka experiment, and similar ones that followed. Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) No, I don't think it is. In GPS the clock is changed on the satellite, but the signal frequency is not the clock frequency, and the question is about the signal frequency. This is false, the clock frequency is changed at launch to be 1,000000000000006 the clock frequency on the ground based GPS devices. For an exact description, see here. "The first two terms in Eq. (54) give rise to the “factory frequency offset”, which is applied to GPS clocks before launch in order to make them beat at a rate equal to that of reference clocks on earth’s surface. The last term in Eq. (54) is very small when the orbit eccentricity is small; when integrated over time these terms give rise to the so-called “” effect or “eccentricity effect”. In most of the following discussion we shall assume that eccentricity is very small." We know the signal changes because of the Pound-Rebka experiment, and similar ones that followed. This part is correct. The GPS explanation is a superset of the Pound-Rebka explanation. There is only difference in gravitational potential and radial motion in the PR experiment. There is no difference in angular velocity. Edited July 28, 2014 by xyzt Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 This is false, the clock frequency is changed at launch to be 1,000000000000006 the clock frequency on the ground based GPS devices. Perhaps you could re-read what I wrote, and tell me what is wrong? This agrees with it. Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 Perhaps you could re-read what I wrote, and tell me what is wrong? This agrees with it. Contrary to your claim, the frequency of the clock on the satellite IS changed. It is preset at launch. Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 Contrary to your claim, the frequency of the clock on the satellite IS changed. It is preset at launch. How is that contrary to my statement that the satellite's clock is changed? Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) How is that contrary to my statement that the satellite's clock is changed? I misread your sentence, I missed that you have a period between "No, I don't think it is". and "In..... Anyways, there is no substantial difference between GPS and PR. In GPS, the frequency is altered at launch precisely in order to avoid the transmission of the frequency of the satellite clock to ground because this would require some very complicated processing by the ground-based device and would drive the price through the roof. So, in effect, GPS is a superset of PR, they are not different experiments. Edited July 28, 2014 by xyzt Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) The fact is that I don't know everything about physics or I wouldn't be asking questions. When I wrote "impossible situation" I wrote it from the perspective of not knowing that the frequency of information might dilate. Actually I'm still not sure what's going with the time dilation as no one seems interested in addressing my questions! With regards to GPS,.. No I don't have it in my car unless I launch it on my hand phone. To be interrogated asking if I have GPS or not is very ridiculous indeed. I'm not an expert but understand that a position can be found from the timing differences of at least three satellites. Any arguments you might having about a GPS device being able to track a change in the GPS signal's frequency should be brought into the OP, imho. Anyway; if the device can track such a change then how can the crystal sync to the satt signal with consistancy ? (Don't answer... really off topic and don't wish to discuss A-Sync or such matters) It's all very well saying "it works just like GPS" but reality is not an electronic device. I'd sincerly like to ask: Does time-dilation occur because of A or B ? (new simple example; time-dilation occurs at a point which is rotating, at an angular velocity, around a central reference clock)... A. space-time has remained unchanged. Light (frequency) has changed.B. space-time has changed. Light frequncy has remained unchanged. It might be the wrong question but at this time it's all I'm capable of asking. Please don't insult me or accuse me of spreading crackpot theories. THANK YOU. Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 With regards to GPS,.. No I don't have it in my car unless I launch it on my hand phone. To be interrogated asking if I have GPS or not is very ridiculous indeed. I'm not an expert but understand that a position can be found from the timing differences of at least three satellites. Any arguments you might having about a GPS device being able to track a change in the GPS signal's frequency should be brought into the OP, imho. No, your question is answered precisely by the GPS functionality. Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 I'd sincerly like to ask: Does time-dilation occur because of A or B ? (new simple example; time-dilation occurs at a point which is rotating, at an angular velocity, around a central reference clock)... A. space-time has remained unchanged. Light (frequency) has changed. B. space-time has changed. Light frequncy has remained unchanged. The frequency you measure depends on your frame. It's not one or the other, it's both. Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) OK, so if I got a laser and spun it round and observed the beam; the colour of the light would be even across the radius. But if I put a light into a length of fibre cable, beaming from the centre, and then sensed the freq at the other (rotating) end with a reading device & also recorded the freq at the rotating end... ...Is the received freq the same as the sent freq ? No, your question is answered precisely by the GPS functionality. I don't see how the above question, relating to space-time, is answered by pining down a vector in space based upon triangulation from three known stationary bodies. This is very bizarre. Do you wish to go onto to explaining Lorentz triangulation already to someone who doesn't even understand something very basic about the universe he finds himself in ? Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) OK, so if I got a laser and spun it round and observed the beam; the colour of the light would be even across the radius. But if I put a light into a length of fibre cable, beaming from the centre, and then sensed the freq at the other (rotating) end with a reading device & also recorded the freq at the rotating end... ...Is the received freq the same as the sent freq ? No, it is not. Janus explained this to you in words. I explained it with words AND math. In the general formula: [math]\displaystyle \frac{f_1}{f_2}= \sqrt{\frac{1-r_s/r_2-\frac{(v_2/c)^2}{1-r_s/r_2}-(\frac{r_2 \omega_2}{c})^2}{1-r_s/r_1-\frac{(v_1/c)^2}{1-r_s/r_1}-(\frac{r_1 \omega_1}{c})^2}}[/math] if you ignore the gravitational effect, you need to make [math]r_s=0[/math] If there is no radial movement between source and receiver, you need to make [math]v_1=v_2=0[/math]. When you do that you get: [math]\displaystyle \frac{f_1}{f_2}= \sqrt{\frac{1-(\frac{r_2 \omega_2}{c})^2}{1-(\frac{r_1 \omega_1}{c})^2}}[/math] Edited July 28, 2014 by xyzt 2 Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) 1. Send light from central point down fibre cable which is on axial rotation. 2. End of fibre contains mirror which reflects light onto ceiling. 3. There is a ring of sensors on celling which can detect light. 4. Let's say we rotate cable for 1 year. We know that the "front end" of the rotational end is 1 week into future space-time compared to our (central) present space-time. 5. We then stop the rotating and wait. After 1 week will there be light sensed by our equipment on ceiling ? Answer is NO ( I think) because any "future" events should have already happened because we are running "slow" compared to the brisk pace of the mirrorring end. So what information do the sensors on the celling receive as we perform the experiment ? If you tell me that the sensors on the celling receive light of another colour then I call you all crackpots, deal ? Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) 4. Let's say we rotate cable for 1 year. We know that the "front end" of the rotational end is 1 week into future space-time compared to our (central) present space-time. Err, no. The "front end", has a total proper elapsed time of [math]\tau_1=\int_0^T {\sqrt{1-(\frac{r_1 \omega}{c}})^2 dt}=T \sqrt{1-(\frac{r_1 \omega}{c}})^2[/math]. Here [math]T=1yr[/math] The "back end", has a total proper elapsed time of [math]\tau_2=T \sqrt{1-(\frac{r_2 \omega}{c}})^2[/math]. Since [math]r_1>r_2[/math] it follows that [math]\tau_1<\tau_2[/math], so your claim is FALSE. So "we know" that you are making erroneous statements, easily disproved by correct application of physics. Edited July 28, 2014 by xyzt Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) By "Front end" I meant time and not the rotating end. Since it follows that , so your claim is FALSE. Yes, I already wrote: After 1 week will there be light sensed by our equipment on ceiling ?Answer is NO ( I think) because any "future" events should have already happened because we are running "slow" compared to the brisk pace of the mirrorring end. I think we agree. it's just the language which has caused a hiccup. So "we know" that you are making erroneous statements, easily disproved by correct application of physics. No I'm not. I said that there would be no information yet to come "in the future" and that all information has already occured. I then pose a question like this "where is the information and how can we sense it"? If you can't discuss these matters without resorting to erroneous attacks because you didn't read the entire post, and mistook two words out of context, then perhaps this thread is not for you. Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) By "Front end" I meant time and not the rotating end. Yes, I already wrote: I think we agree. it's just the language which has caused a hiccup. No I'm not. I said that there would be no information yet to come "in the future" and that all information has already occured. Your first statement (the one I redlined earlier) was incorrect. You are trying to make it look as you agree with me. Your second statement (the one in blue) makes no sense whatsoever. So, no, we do not agree. Edited July 28, 2014 by xyzt Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) You can't say it (red highlighted statement) was incorrect if you didn't understand it as I meant to convey it. You have the free will to ask for clarification but you choose not to do so. So, no, we do not agree. Do you think there is information which has not already occured which exists in the future ? If NO then I do think we basically agree. Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 OK, so if I got a laser and spun it round and observed the beam; the colour of the light would be even across the radius. No. The frequency would vary with the radius. The experiment has been done with gammas emitted from a central stationary source and an absorber on a ring. The resonance shifts if the ring is spinning, i.e. the gammas are at a different frequency. The amount of the shift depends on the linear speed, which for a constant angular speed, varies with r. http://blogs.scienceforums.net/swansont/archives/date/2009/02/10 I think the experiment I'm referring to is the last one listed Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) No. The frequency would vary with the radius. In a free space? The example given was independent of any end to end contained transmission enclosure or medium such as polymer glass substrate with reflective wall. Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 In a free space? The example given was independent of any end to end contained transmission enclosure or medium such as polymer glass substrate with reflective wall. Yes, free space transmission. I have included details in my previous post; I was editing while you posted this Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 (edited) Your example is not the same as mine. Yes, free space transmission. I have included details in my previous post; I was editing while you posted this it's not free space transmission as per my example as you have mass doing some detection which is distorting space-time because of its velocity... My example was detection by looking with your eyes... not with a rotating mass. Edited July 28, 2014 by radicalsymmetry Link to comment Share on other sites More sharing options...
swansont Posted July 28, 2014 Share Posted July 28, 2014 Your example is not the same as mine. it's not free space transmission as per my example as you have mass doing some detection which is distorting space-time because of its velocity... My example was detection by looking with your eyes... not with a rotating mass. I didn't realize that your eyes were massless. For the rest of us, the situation is analogous. Link to comment Share on other sites More sharing options...
radicalsymmetry Posted July 28, 2014 Author Share Posted July 28, 2014 I didn't realize that your eyes were massless. For the rest of us, the situation is analogous. I accept your reply for what it is. Link to comment Share on other sites More sharing options...
xyzt Posted July 28, 2014 Share Posted July 28, 2014 (edited) You can't say it (red highlighted statement) was incorrect if you didn't understand it as I meant to convey it. I understood perfectly, your statement is incorrect. Both the redlined one and the bluelined one. Edited July 28, 2014 by xyzt Link to comment Share on other sites More sharing options...
imatfaal Posted July 29, 2014 Share Posted July 29, 2014 ! Moderator Note radicalsymmetry - I have moved this thread to speculations. I no longer believe you are labouring under a misconception but rather that you are looking to challenge agreed science. A refusal to concede you have made an error or that a point has been answered does not sit well with rational science or any quest for learning. Do not respond within the thread to this moderation. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now