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 28th April 2012, 09:07 AM #121 Michael C Graduate Poster     Join Date: Apr 2007 Location: N 49° 52' 3" E 8° 40' 21" Posts: 1,852 Originally Posted by keyfeatures You broke the eggs, not me. So you are suggesting that, for example, "12 minutes" is an adequate definition of the change between the two states? No, I never sugggested anything of the kind. I can tell you that the time it took to effect the change was approximately 2 minutes, but I do not have a unit to quantify the change itself: that's what I'm asking you to provide. Quote: Okay, what are you using to measure this "well-defined period of time". I've already explained that the thing that is measured is not the same as the thing used to measure it. I cannot pick up a piece of time to measure time any more than I can pick up a piece of distance to measure distance.
 28th April 2012, 09:34 AM #122 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by anglolawyer Thanks to both Farsight and Merton. Interesting stuff. Farsight's link threw up this: Eek! And then this: I guess the fact the universe can be wound up (like a clock) doesn't break any laws because the energy for the winding up must have come from outside the system? Whoa! Don't get sucked into theology. We just don't know how the universe began, and stuff like "somebody wound it up" is just a turtles all the way down non-answer because what they don't say is who wound up the winder. Sorry if I put up a link that took you down that road. Originally Posted by anglolawyer I will do that ... In fact, I just did and he looks like my kind of guy. Thanks. He gets into to very speculative stuff, and you should be sceptical. Celebrity physicists sometimes give turtles all the way down non-answers too. Aw, I'll spit it out: sometimes they peddle woo.
 28th April 2012, 10:06 AM #123 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by keyfeatures Vibrations within vibrations. Also, the path integral (if considered a real physical event) must be averaged in part from the superluminal. Is c a meanie? I don't think so. The path integral is there because waves are "extended entities". For example a seismic wave propagating from A to B isn't restricted to a straight line drawn between those two points. That line might mark out maximum intensity, but if you're a mile to the North of the line you still feel the ground vibrating. Originally Posted by keyfeatures So what has been used to calibrate this "very consistent quantity" of time? MichaelC: it's the motion of light, or if you prefer, the motion of electromagnetic phenomena. The NIST clock, which is used to define the second, uses microwaves. These are emitted by the hyperfine transition, which is an electromagnetic spin-flip. Stretch an elastic band between your finger and thumb, and stick a short pencil through it, then swing the pencil over and let go. It's something like that. In the old days before relativity they used to use some other kind of motion. A year is how "long" it takes the Earth to move round the sun. A day is how long it takes the Earth to spin once. It always comes back to motion one way or another. Originally Posted by solinvictus According to modern physics, you're wrong. Time is a dimension almost exactly like those of space. And indeed, everything you're saying applies just as well to space as it does to time (unsurprisingly). Until you address that, it's hard to take your opinions seriously. You're talking out of your hat. If you don't believe me, get up out of your chair, and hop back a metre. Easy peasy. Now hop back a second. Hey, what's the problem? Everything you're saying applies just as well to space as it does to time? No it doesn't. So please, spare us the hard to take your opinions seriously. All: space isn't the same as time, and it isn't the same as nothing. It sustains waves and fields, and it has its inherent vacuum energy. Have a look at Einstein's 1920 Leyden Address and he's talking about it as if it's "elastic stuff". Here's an excerpt: "This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that “empty space” in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials gμν), has, I think, finally disposed of the view that space is physically empty".
 28th April 2012, 11:04 AM #124 Kwalish Kid Critical Thinker   Join Date: Feb 2010 Posts: 379 Originally Posted by Farsight You're talking out of your hat. If you don't believe me, get up out of your chair, and hop back a metre. Easy peasy. Now hop back a second. Hey, what's the problem? Everything you're saying applies just as well to space as it does to time? No it doesn't. So please, spare us the hard to take your opinions seriously. Stop ignoring everything done in rigorous physics and the things that people actually post. In actual physics, people record the time that things happen. They assign coordinates to space and coordinates to time. Additionally, measuring the distance between objects also requires that we take motion into account just like measuring time, so any argument that there is no time because we have to measure motion equally applies to space. Quote: All: space isn't the same as time, and it isn't the same as nothing. It sustains waves and fields, and it has its inherent vacuum energy. Have a look at Einstein's 1920 Leyden Address and he's talking about it as if it's "elastic stuff". Here's an excerpt: "This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that “empty space” in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials gμν), has, I think, finally disposed of the view that space is physically empty". Here's a quotation from that website, "This address has been frequently misunderstood as positing that a return of the ether theory." Farsight willfully ignores this claim, willfully avoids learning the actually theory of Einstein along with its mathematics, and almost always distorts physics. He likes this particular quotation from Einstein, but again he shows his complete ignorance of the theory: these "ten functions" that Einstein talks about are spacetime functions, functions over an amalgamation of space and time represented as a tensor, not functions over space with or without a separate time variable.
 28th April 2012, 01:03 PM #125 ynot Illuminator     Join Date: Jan 2006 Location: New Zealand Posts: 4,646 Originally Posted by Michael C In fact I don't even know of an accepted way to quantify "change". Originally Posted by Michael C Yes, that's the definition of a second of time. It's one very specific change which is used for defining time because we have observed that the time taken for these transitions is a very consistent quantity. Originally Posted by Michael C . I can tell you that the time it took to effect the change was approximately 2 minutes, but I do not have a unit to quantify the change itself . . . __________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 28th April 2012 at 02:15 PM.
 28th April 2012, 01:33 PM #126 RobDegraves Muse   Join Date: Mar 2009 Posts: 787 Quote: Here's a quotation from that website, "This address has been frequently misunderstood as positing that a return of the ether theory." Farsight willfully ignores this claim, willfully avoids learning the actually theory of Einstein along with its mathematics, and almost always distorts physics. He likes this particular quotation from Einstein, but again he shows his complete ignorance of the theory: these "ten functions" that Einstein talks about are spacetime functions, functions over an amalgamation of space and time represented as a tensor, not functions over space with or without a separate time variable. Interesting. I love Einstein, but I am constantly aghast as to how often he is misinterpreted in order to justify specific unscientific ideas. I think he would share my disgust at the practice.
 28th April 2012, 01:48 PM #127 ynot Illuminator     Join Date: Jan 2006 Location: New Zealand Posts: 4,646 IMO . . . Without motion time is no more than an abstract concept. Without “stuff” distance is no more than an abstract concept __________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.
 28th April 2012, 03:46 PM #128 Perpetual Student Illuminator     Join Date: Jul 2008 Location: USA Posts: 3,707 Originally Posted by ynot IMO . . . Without motion time is no more than an abstract concept. Without “stuff” distance is no more than an abstract concept I'm not sure I understand your argument here. An empty universe is just that -- empty. No time; no space, no matter. The ideas of time and space are the consequence of a changing and moving universe, so time and space are concepts devised by man to deal with the universe as we experience it. In modern times, we have been able to define these concepts to the precise levels needed to do science in order to develop tools with great predictive power -- like Newton's Maxwell's and Einstein's theories. Saying that motion is more fundamental may be a fun philosophic idea, but it does not seem to bring anything to the table to improve our understanding about how the universe works. Am I missing your point? __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 28th April 2012, 03:49 PM #129 Perpetual Student Illuminator     Join Date: Jul 2008 Location: USA Posts: 3,707 Originally Posted by Kwalish Kid Stop ignoring everything done in rigorous physics and the things that people actually post. In actual physics, people record the time that things happen. They assign coordinates to space and coordinates to time. Additionally, measuring the distance between objects also requires that we take motion into account just like measuring time, so any argument that there is no time because we have to measure motion equally applies to space. Here's a quotation from that website, "This address has been frequently misunderstood as positing that a return of the ether theory." Farsight willfully ignores this claim, willfully avoids learning the actually theory of Einstein along with its mathematics, and almost always distorts physics. He likes this particular quotation from Einstein, but again he shows his complete ignorance of the theory: these "ten functions" that Einstein talks about are spacetime functions, functions over an amalgamation of space and time represented as a tensor, not functions over space with or without a separate time variable. Farsight has some kind of homespun personal make-believe physics that has little to do with real science -- it's merely a game. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 28th April 2012, 04:29 PM #130 ynot Illuminator     Join Date: Jan 2006 Location: New Zealand Posts: 4,646 Originally Posted by Perpetual Student I'm not sure I understand your argument here. An empty universe is just that -- empty. No time; no space, no matter. The ideas of time and space are the consequence of a changing and moving universe, so time and space are concepts devised by man to deal with the universe as we experience it. In modern times, we have been able to define these concepts to the precise levels needed to do science in order to develop tools with great predictive power -- like Newton's Maxwell's and Einstein's theories. Saying that motion is more fundamental may be a fun philosophic idea, but it does not seem to bring anything to the table to improve our understanding about how the universe works. Am I missing your point? Some are claiming that time exists independently of motion and that motion is merely used to measure time. Some are claiming that distance exists independently of “stuff” and that “stuff” is merely used to measure distance. If these claims were true then a Universe without motion and “stuff” would still contain time and distance. __________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 28th April 2012 at 04:48 PM.
 28th April 2012, 04:52 PM #131 Perpetual Student Illuminator     Join Date: Jul 2008 Location: USA Posts: 3,707 Originally Posted by ynot Some are claiming that time exists independently of motion and that motion is merely used to measure time. Some are claiming that distance exists independently of “stuff” and that “stuff” is merely used to measure distance. If this were so then a Universe without motion and “stuff” would still contain time and distance. According to current cosmological thinking, space, time, matter and energy all came into existence 13.75 or so billion years ago. A universe missing any of those elements does not seem to have much meaning. What would time and space mean in an otherwise empty universe? This seems to be like one of those meaningless questions like whether there is sound if no one is there to hear it. I think these are mere linguistic ambiguities with no real scientific substance -- so it's my inclination to dismiss such questions as not being questions at all. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 28th April 2012, 05:21 PM #132 Kwalish Kid Critical Thinker   Join Date: Feb 2010 Posts: 379 Originally Posted by Perpetual Student According to current cosmological thinking, space, time, matter and energy all came into existence 13.75 or so billion years ago. No, this is not current cosmological thinking and it is important to be clear on this. Current cosmological thinking is that we can't describe the universe past a point about 13.75 or so billion years ago. There are a number of speculations, but they are not representative of a consensus scientific position. However, those that claim that there actually is time and that it is a dimension do not necessarily claim that it has some kind of independent existence outside of any existing thing. Time is part of descriptions of movement--particularly acceleration--and of physical processes that do not necessarily involve movement like particle decay. In order to describe what a force is or what a deviation from free motion is, we need to have some definition of time. We cannot pretend that one thing is somehow prior to the other.
 28th April 2012, 05:35 PM #133 ynot Illuminator     Join Date: Jan 2006 Location: New Zealand Posts: 4,646 Originally Posted by Perpetual Student According to current cosmological thinking, space, time, matter and energy all came into existence 13.75 or so billion years ago. So current cosmological thinking supports creation as in something from nothing? If so then I don't support current cosmological thinking. Originally Posted by Perpetual Student A universe missing any of those elements does not seem to have much meaning. What would time and space mean in an otherwise empty universe? This seems to be like one of those meaningless questions like whether there is sound if no one is there to hear it. I think these are mere linguistic ambiguities with no real scientific substance -- so it's my inclination to dismiss such questions as not being questions at all. It's not a matter of "meaning" (hardly "real scientific substance") it a matter of actual existence. Do they or don't they? Please explain what the meaning of the Universe is. __________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.
 28th April 2012, 11:19 PM #134 Michael C Graduate Poster     Join Date: Apr 2007 Location: N 49° 52' 3" E 8° 40' 21" Posts: 1,852 Originally Posted by ynot Without “stuff” distance is no more than an abstract concept How much "stuff" is there between the Earth and the Sun?
 28th April 2012, 11:55 PM #135 ynot Illuminator     Join Date: Jan 2006 Location: New Zealand Posts: 4,646 Originally Posted by Michael C How much "stuff" is there between the Earth and the Sun? It's choc-a-block full of non-material stuff. From time to time there's also some material stuff like a couple of planets, a moon, asteroids, a Space Station, etc. There's also the possibilty of dark matter and anti-matter to consider. Space is empty like a room with no furniture or fittngs is empty. Do you think that there is absolutely nothing between the Earth and Sun? Wonder why we can't travel to the moon or planets in nothing time then? __________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 29th April 2012 at 12:34 AM.
 29th April 2012, 05:01 AM #136 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 ETA: well said ynot. Originally Posted by Kwalish Kid Stop ignoring everything done in rigorous physics and the things that people actually post. I'm not. I'm being rigorous. It isn't rigorous to say clocks measure the flow of time or that we travel through time at the rate of one second per second. Or that space and time are on an equal footing. They aren't. You can't hop back a second. And there's a minus sign on the t term in the Lorentz interval expression $ds^2 = -dt^2 + dx^2 + dy^2 + dz^2$. It's negative because clocks clock up motion. The interval is invariant because when I sit here with my parallel-mirror light clock whilst you go on an out-and-back trip with yours, the light moves the same amount between the events of our departure and rendezvous. Originally Posted by Kwalish Kid In actual physics, people record the time that things happen. They assign coordinates to space and coordinates to time. Additionally, measuring the distance between objects also requires that we take motion into account just like measuring time, so any argument that there is no time because we have to measure motion equally applies to space. Who's arguing that there is no time? Not me. All I'm saying is that it's an emergent phenomena, like heat, only it's a cumulative measure of motion rather than an average. Originally Posted by Kwalish Kid Here's a quotation from that website, "This address has been frequently misunderstood as positing that a return of the ether theory." Farsight willfully ignores this claim, willfully avoids learning the actually theory of Einstein along with its mathematics, and almost always distorts physics. He likes this particular quotation from Einstein, but again he shows his complete ignorance of the theory: these "ten functions" that Einstein talks about are spacetime functions, functions over an amalgamation of space and time represented as a tensor, not functions over space with or without a separate time variable. I'm not wilfully ignoring anything. You're the one doing that. Now go and read what Einstein actually said: "Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it." It doesn't blow or flow like the old luminiferous aether. Go and read some of the gravitational aether papers on arXiv too. But you won't, will you? You'll just wilfully ignore them. Last edited by Farsight; 29th April 2012 at 05:10 AM.
 29th April 2012, 05:04 AM #137 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by RobDegraves I love Einstein, but I am constantly aghast as to how often he is misinterpreted in order to justify specific unscientific ideas. I think he would share my disgust at the practice. Ditto. We get all sorts of nonsense, such as the possibility of time travel, the universe rotating around a top that isn't really spinning, space falling inwards in a gravitational field, and so on. Total woo. Originally Posted by Perpetual Student Saying that motion is more fundamental may be a fun philosophic idea, but it does not seem to bring anything to the table to improve our understanding about how the universe works. Am I missing your point? You are. Once you understand this, you understand gravity. Then electromagnetism, then other things too. It's like dominoes. Originally Posted by Perpetual Student Farsight has some kind of homespun personal make-believe physics that has little to do with real science -- it's merely a game. No it isn't. I've read the original Einstein, you should try it sometime. Then you'll find out who's peddling make-believe physics. Last edited by Farsight; 29th April 2012 at 05:09 AM.
 29th April 2012, 06:02 AM #138 RobDegraves Muse   Join Date: Mar 2009 Posts: 787 Quote: No it isn't. I've read the original Einstein, you should try it sometime. Then you'll find out who's peddling make-believe physics. So have I, and likely so have a number of people who post here. It's not impressive unless you understood it... which obviously you have not. More to the point, you cannot take one thing he said in isolation without considering the rest. You can also not take just Einstein and ignore the rest of the world of physics. Quote: I'm not. I'm being rigorous. It isn't rigorous to say clocks measure the flow of time or that we travel through time at the rate of one second per second. Or that space and time are on an equal footing. They aren't. You can't hop back a second And... you don't have negative space in reality either. Everything you say about time applies to space as well. Yet both exist. Quote: Ditto. We get all sorts of nonsense, such as the possibility of time travel, the universe rotating around a top that isn't really spinning, space falling inwards in a gravitational field, and so on. Total woo. Hmmm.... we also get all sorts of nonsense like time doesn't exist, Farsight understands gravity and electromagnetism better than anyone else, etc. Total woo. PS... you do get the difference between assertion and proof don't you? If you understand these things so much better than everyone else in the world of physics, I am shocked that we don't see your name in peer reviewed publications. Well.. not that shocked. Last edited by RobDegraves; 29th April 2012 at 06:06 AM.
 29th April 2012, 06:14 AM #139 Tubbythin Illuminator   Join Date: Mar 2008 Posts: 3,206 Originally Posted by RobDegraves PS... you do get the difference between assertion and proof don't you? If you understand these things so much better than everyone else in the world of physics, I am shocked that we don't see your name in peer reviewed publications. Well.. not that shocked. Don't you know that Farsight is the victim of the global suppression of TRUE physics. I mean, don't you know that's what peer review is all about isn't it?
 29th April 2012, 07:05 AM #140 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by RobDegraves So have I, and likely so have a number of people who post here. It's not impressive unless you understood it... which obviously you have not. I understand it, you don't. If you did, you wouldn't labour under the illusion that the possibility of time travel hinges on causality. That's pop-science garbage, the sort of nonsense promoted by celebrity "physicists" peddling woo like time travel and the multiverse. Originally Posted by RobDegraves More to the point, you cannot take one thing he said in isolation without considering the rest. You can also not take just Einstein and ignore the rest of the world of physics. I don't. And I'm forever giving references to the rest of the world of physics. I give more and better references than anybody else here. Originally Posted by RobDegraves And... you don't have negative space in reality either. It isn't negative time. Let's try again. The expression for a spacetime interval in flat Minkowski spacetime is this: $ds^2 = -dt^2 + dx^2 + dy^2 + dz^2$ It's related to Pythagoras' theorem, used in the Simple inference of time dilation due to relative velocity. We've got two parallel-mirror light clocks, one in front of us, the other travelling out-and-back. We see the light moving like this ǁ in the local clock and like this /\ in the moving clock. Treat one side of the angled path as a right-angled triangle and the hypotenuse is the lightpath where c=1 in natural units, the base is the speed v as a fraction of c, and the height gives the Lorentz factor γ = 1/√(1-v²/c²). If the moving mirror is going at .99c the Lorentz factor is 1/√(1-0.99²/1²) = 1/√(1-0.98) = 1/√0.2 = 1/0.142 = 7. So there's a sevenfold time dilation. And get this: there's no literal time flowing in these clocks, just light moving back and forth between the mirrors. The invariant interval between the start and end events of our gedankenexperiment is because the two light-path lengths are the same. It's that simple. Macroscopic motion comes at the cost of a reduced local rate of motion. Hence the minus in front of the t. It's like Pythagoras' theorem a² = b² + c² because you work out the height of the triangle via b² = -c² + a². Originally Posted by RobDegraves Everything you say about time applies to space as well. Space and time are different. You can move through space. You can't move through time. Because it's derived from motion through space. Originally Posted by RobDegraves Yet both exist. I said time exists. It exists like heat exists. That's an emergent phenomenom too. Originally Posted by RobDegraves Hmmm.... we also get all sorts of nonsense like time doesn't exist, Farsight understands gravity and electromagnetism better than anyone else, etc. Total woo. PS... you do get the difference between assertion and proof don't you? If you understand these things so much better than everyone else in the world of physics, I am shocked that we don't see your name in peer reviewed publications. Well.. not that shocked. Whatever happened to sincere discussion and counterargument? I think it's rather sad that people buy into mystery and woo because they don't understand the physics. And even sadder when somebody explains it, but they just aren't listening. They prefer to cling to their mystery and woo, so they sling mud instead.
 29th April 2012, 07:28 AM #141 Tubbythin Illuminator   Join Date: Mar 2008 Posts: 3,206 Originally Posted by Farsight I don't. And I'm forever giving references to the rest of the world of physics. I give more and better references than anybody else here. You references are frequently a google page of search results. Do you think that constitutes great refereeing?
 29th April 2012, 07:39 AM #142 RobDegraves Muse   Join Date: Mar 2009 Posts: 787 Quote: I understand it, you don't. If you did, you wouldn't labour under the illusion that the possibility of time travel hinges on causality. That's pop-science garbage, the sort of nonsense promoted by celebrity "physicists" peddling woo like time travel and the multiverse. Quote: I don't. And I'm forever giving references to the rest of the world of physics. I give more and better references than anybody else here. Quote: Space and time are different. You can move through space. You can't move through time. Because it's derived from motion through space. Quote: Whatever happened to sincere discussion and counterargument? I think it's rather sad that people buy into mystery and woo because they don't understand the physics. And even sadder when somebody explains it, but they just aren't listening. They prefer to cling to their mystery and woo, so they sling mud instead. You still don't get the difference between assertion and proof do you? For that matter, you don't seem to get the irony lurking behind your assertions. Quote: It isn't negative time. Let's try again. The expression for a spacetime interval in flat Minkowski spacetime is this: I didn't say negative time. Try actually reading. Time and space are both ways to measure the world. They both have a similar existence and you don't see that whatever you say about time also applies to space. You don't normally get a reversal of time (ie time travel) in the same way that you don't normally get negative space. What you really don't get is the whole idea, brought up by Einstein, that by combining space and time into a single manifold, it does a better job at explaining and predicting physical processes than any other theory. If you had a better theory, I would expect you to publish it properly... not just come here and repeat your simplistic theory over and over again. For example, you have yet to explain time dilation in a coherent way. I know that you think you have... but that's a different matter altogether. What you intend to accomplish is beyond me. In all the threads I have seen you post, you purvey endless woo, from cold fusion to time isn't real, to whatever else you are selling. It's boring and repetitive. Try some real research sometime.
 29th April 2012, 08:05 AM #143 keyfeatures Critical Thinker     Join Date: Feb 2012 Location: My head Posts: 420 A quick skim quickly reveals those posts with content and those that are just appeal to authority and ad hom. I'm enjoying the former. Last edited by keyfeatures; 29th April 2012 at 08:06 AM.
 29th April 2012, 08:51 AM #144 Kwalish Kid Critical Thinker   Join Date: Feb 2010 Posts: 379 Originally Posted by Farsight ETA: well said ynot. I'm not. I'm being rigorous. It isn't rigorous to say clocks measure the flow of time or that we travel through time at the rate of one second per second. It is a strawman argument to say that this is the content of physics. We all know that you are ignorant of the content of physics because you keep getting things wrong again and again. It is important to point these things out to the youngsters. In physics, a claim is made about the velocity of a body relative to other bodies or to some standard. The same is said about acceleration. These are also used in defining forces, e.g., in measuring the force acting on a body that is causing it to deviate from free (fall) motion. We have to have some way of saying what free (fall) motion is and this requires that we have some definition of time for that motion. You are saying that one standard of time for motion is correct. But you fail to produce this standard. Quote: Or that space and time are on an equal footing. They aren't. You can't hop back a second. And there's a minus sign on the t term in the Lorentz interval expression $ds^2 = -dt^2 + dx^2 + dy^2 + dz^2$. It's negative because clocks clock up motion. The interval is invariant because when I sit here with my parallel-mirror light clock whilst you go on an out-and-back trip with yours, the light moves the same amount between the events of our departure and rendezvous. Again, you fail to produce this standard. Against what are you measuring motion? You are saying that there is some absolute reference frame when you cannot provide one and that is not how physics is done. How are you measuring $-dt^2$ when according to you there is no actual change in time. If you would like to replace that equation with something else, as those who argue about the nature of heat do, then you should do so. Quote: Who's arguing that there is no time? Not me. All I'm saying is that it's an emergent phenomena, like heat, only it's a cumulative measure of motion rather than an average. And you need to show your work, mathematically. Quote: I'm not wilfully ignoring anything. Yes, you are clearly ignoring the caveats on the website that you are citing. You are also ignoring the caveats Einstein said. Your cherry-picking may impress those who do no research, but it clearly fails as soon as someone starts reading. Quote: It doesn't blow or flow like the old luminiferous aether. Go and read some of the gravitational aether papers on arXiv too. But you won't, will you? You'll just wilfully ignore them. I actually interact regularly with the author of one of those papers. The work of that author in no way supports your claims. Since you can't be bothered to even cherry-pick from those papers, I assume that you realize that.
 29th April 2012, 08:54 AM #145 RobDegraves Muse   Join Date: Mar 2009 Posts: 787 @keyfeatures Quote: A quick skim quickly reveals those posts with content and those that are just appeal to authority and ad hom. I'm enjoying the former. If that is a poorly veiled reference to my posts... Appeal to authority... Quote: The appeal to authority may take several forms. As a statistical syllogism, it will have the following basic structure:[1] Most of what authority a has to say on subject matter S is correct. a says p about S. Therefore, p is correct. The strength of this argument depends upon two factors:[1][2] The authority is a legitimate expert on the subject. A consensus exists among legitimate experts on the matter under discussion. These conditions may also simply be incorporated into the structure of the argument itself, in which case the form may look like this:[2] X holds that A is true X is a legitimate expert on the subject. The consensus of experts agrees with X. Therefore, there's a presumption that A is true. Fallacious appeals to authority Fallacious arguments from authority often are the result of failing to meet at least one of the two conditions from the previous section Unfortunately for you, in this case an appeal to authority is valid. The vast majority (if not all) of legitimate physicists would disagree with Farsight. In addition, the subject is complex enough to warrant looking at what experts are saying rather than make up our own theories based on a lack of proper understanding of the subject matter. Just as I would not want to see Farsight operating as a surgeon, I would not expect his word alone to carry in a complex subject like relativity without some evidence that he has an advanced understanding of the subject. So far that has not happened. PS... having just read Kwalish Kid's post, it seems obvious that his knowledge of physics is better than Farsight's or mine. It is significant that I have yet to see Farsight respond substantially to his posts. I would be interested in seeing that. Last edited by RobDegraves; 29th April 2012 at 08:58 AM.
 29th April 2012, 09:12 AM #147 Perpetual Student Illuminator     Join Date: Jul 2008 Location: USA Posts: 3,707 Originally Posted by Kwalish Kid No, this is not current cosmological thinking and it is important to be clear on this. Current cosmological thinking is that we can't describe the universe past a point about 13.75 or so billion years ago. There are a number of speculations, but they are not representative of a consensus scientific position. Yes, I did overstate the case. Nevertheless, there are quite a few cosmologists who would agree with the statement that time, space, matter and energy began 13.75 or so billion years ago. Quote: However, those that claim that there actually is time and that it is a dimension do not necessarily claim that it has some kind of independent existence outside of any existing thing. Time is part of descriptions of movement--particularly acceleration--and of physical processes that do not necessarily involve movement like particle decay. In order to describe what a force is or what a deviation from free motion is, we need to have some definition of time. We cannot pretend that one thing is somehow prior to the other. Yes. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 29th April 2012, 02:52 PM #148 ynot Illuminator     Join Date: Jan 2006 Location: New Zealand Posts: 4,646 Originally Posted by Michael C How much "stuff" is there between the Earth and the Sun? Originally Posted by ynot Do you think that there is absolutely nothing between the Earth and Sun? I answered your question. Now it's your turn . . . __________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.
 29th April 2012, 04:32 PM #149 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by RobDegraves I didn't say negative time. Try actually reading. I read what you said. You also said everything you say about time applies to space as well so I explained the Lorentz interval for you, and why the t term was negative... Originally Posted by RobDegraves Time and space are both ways to measure the world. They both have a similar existence and you don't see that whatever you say about time also applies to space. ...but you still insist that time and space are on an equal footing? They aren't. Originally Posted by RobDegraves You don't normally get a reversal of time (ie time travel) in the same way that you don't normally get negative space. That's nothing to do with it. You have freedom of motion in the space dimensions. You have no such freedom of motion in the time dimension. Originally Posted by RobDegraves What you really don't get is the whole idea, brought up by Einstein, that by combining space and time into a single manifold, it does a better job at explaining and predicting physical processes than any other theory. If you had a better theory, I would expect you to publish it properly... not just come here and repeat your simplistic theory over and over again. I get it. I really get it. And the thing I got first was that it was Minkowski who combined space and time into a single manifold. Originally Posted by RobDegraves For example, you have yet to explain time dilation in a coherent way. I know that you think you have... but that's a different matter altogether. What you intend to accomplish is beyond me. In all the threads I have seen you post, you purvey endless woo, from cold fusion to time isn't real, to whatever else you are selling. It's boring and repetitive. Try some real research sometime. LOL.
 29th April 2012, 05:38 PM #150 Kwalish Kid Critical Thinker   Join Date: Feb 2010 Posts: 379 Originally Posted by Farsight I read what you said. You also said everything you say about time applies to space as well so I explained the Lorentz interval for you, and why the t term was negative... That you think that this is relevant to his comment doesn't make you look very bright. He was making a response to a set of specific comments. The burden is on you to show how the interval is relevant to these initial comments. Quote: That's nothing to do with it. You have freedom of motion in the space dimensions. You have no such freedom of motion in the time dimension. Except that we clearly do, since we are free to describe part of our motion in whatever reference frame we wish, so we can call a different amount of our motion as motion through time. This is pretty basic relativity theory.
 29th April 2012, 05:48 PM #151 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by Robdegraves PS... having just read Kwalish Kid's post, it seems obvious that his knowledge of physics is better than Farsight's or mine. It is significant that I have yet to see Farsight respond substantially to his posts. You're fooling nobody. I give substantial responses. Here's another one: * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Originally Posted by Kwalish Kid It is a strawman argument to say that this is the content of physics. We all know that you are ignorant of the content of physics because you keep getting things wrong again and again. It is important to point these things out to the youngsters. No physics there. Moving on... Originally Posted by Kwalish Kid In physics, a claim is made about the velocity of a body relative to other bodies or to some standard. The same is said about acceleration. These are also used in defining forces, e.g., in measuring the force acting on a body that is causing it to deviate from free (fall) motion. We have to have some way of saying what free (fall) motion is and this requires that we have some definition of time for that motion. This is a digression plus a circular argument that ignores natural units as per my post #140. The Lorentz factor γ = 1/√(1-v²/c²) employs natural units, wherein c=1 and v is a fraction of c. We work out time dilation as for example 1/√(1-0.99²/1²) = 1/√(1-0.98) = 1/√0.2 = 1/0.142 = 7. And yet there's no t in the expression. Score one to me. Originally Posted by Kwalish Kid You are saying that one standard of time for motion is correct. But you fail to produce this standard. Kwalish Kid hasn't been paying attention. I produced the standard in post #63 concerning the NIST definition of the second. In the NIST fountain Caesium clock, hyperfine transitions emit microwaves with a "resonant frequency". But frequency is measured in Hertz, which is cycles per second, and the second isn't defined yet. So frequency goes out of the window. We're counting incoming microwave peaks, and when we get to 9,192,631,770, we say that's a second. Like the metre it's defined using the motion of light. Score two to me. Originally Posted by Kwalish Kid Again, you fail to produce this standard. Against what are you measuring motion? You are saying that there is some absolute reference frame when you cannot provide one and that is not how physics is done. Definitely not paying attention. I explained this on the Terra revolving round Sol thread. I said the CMBR allows us to gauge our motion through the universe. It doesn't provide an "absolute reference frame" in that inside a black box you can't tell whether you're moving. But all you have to do is look out the window and then you can. The universe is as absolute as it gets, motion is relative, but when it's relative to the universe, that's the end of the line. Score three to me. Originally Posted by Kwalish Kid How are you measuring $-dt^2$ when according to you there is no actual change in time. If you would like to replace that equation with something else, as those who argue about the nature of heat do, then you should do so. Total straw man, I never said or suggested that there's no actual change in time. Score four to me. Originally Posted by Kwalish Kid And you need to show your work, mathematically. I did, in post #140 where I explained the Lorentz factor γ = 1/√(1-v²/c²) and showed how it's based on Pythagoras' Theorem. Simple stuff. Score five to me. Originally Posted by Kwalish Kid Yes, you are clearly ignoring the caveats on the website that you are citing. You are also ignoring the caveats Einstein said. Your cherry-picking may impress those who do no research, but it clearly fails as soon as someone starts reading. This is a physics-free jibe that attempts to persuade the reader to dismiss what Einstein said on the specious grounds of "cherry picking". And fails miserably. I'll take a point for that, because if there's one thing I don't like it's people dismissing Einstein and encouraging others to do so. Score six to me. Originally Posted by Kwalish Kid I actually interact regularly with the author of one of those papers. The work of that author in no way supports your claims. Since you can't be bothered to even cherry-pick from those papers, I assume that you realize that. Yawn. Another physics-free ad hominem. the fact remains that there are plenty of papers on gravitational aether. And since I give lots of regference whilst Kwalish Kid gives none, I'll take another point. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Originally Posted by Robdegraves I would be interested in seeing that. See above. Seven nil. I wiped the floor with the guy. Only doubtless you will try to pretend otherwise.
 29th April 2012, 06:00 PM #152 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by Kwalish Kid That you think that this is relevant to his comment doesn't make you look very bright. He was making a response to a set of specific comments. The burden is on you to show how the interval is relevant to these initial comments. I've responded to his comments. If he seeks a further reponse or clarification he only has to ask, and I'll be only to glad to give it. Originally Posted by Kwalish Kid Except that we clearly do, since we are free to describe part of our motion in whatever reference frame we wish, so we can call a different amount of our motion as motion through time. Except that we clearly don't. You have no freedom of motion in the time dimension. If you did, you could hop back a second. Or take a trip to the middle of next week. And guess what? You can't. And should you take a fast round trip and come back, you don't arrive in my past. You merely experience less local motion because of your macroscopic motion. It's that simple. There's no time flowing between those parallel-mirrors. Just light moving. Originally Posted by Kwalish Kid This is pretty basic relativity theory. Yawn. You don't understand basic relativity theory at all. Not a bit. And I'm going to bed.
 29th April 2012, 11:42 PM #155 keyfeatures Critical Thinker     Join Date: Feb 2012 Location: My head Posts: 420 This is an interesting pitch for the TSA. The plausibility of the TSA first principles are tested by coupling to fundamental matter. Yang–Mills theory works. I criticize the original form of the TSA since I find that tacit assumptions remain and Dirac fields are not permitted. However, comparison with Kuchaˇr’s hypersurface formalism allows me to argue that all the known fundamental matter fields can be incorporated into the TSA. The spacetime picture appears to possess more kinematics than strictly necessary for building Lagrangians for physically-realized fundamental matter fields. I debate whether space may be regarded as primary rather than spacetime. The emergence (or not) of the Special Relativity Principles and 4-d General Covariance in the various TSA alternatives is investigated, as is the Equivalence Principle, and the Problem of Time in Quantum Gravity. Last edited by keyfeatures; 29th April 2012 at 11:46 PM.
 30th April 2012, 02:16 AM #156 Tubbythin Illuminator   Join Date: Mar 2008 Posts: 3,206 Originally Posted by Farsight The Lorentz factor γ = 1/√(1-v²/c²) employs natural units, wherein c=1 and v is a fraction of c. We work out time dilation as for example 1/√(1-0.99²/1²) = 1/√(1-0.98) = 1/√0.2 = 1/0.142 = 7. You can use any relevant way of measuring speed that you like in the Lorentz factor. Natural units, m/s, miles/hour, mm/day, furlongs/fortnight. As long as you use the same units for v and c you'll get the same answer. That's because γ is dimensionless.
 30th April 2012, 02:20 AM #157 Michael C Graduate Poster     Join Date: Apr 2007 Location: N 49° 52' 3" E 8° 40' 21" Posts: 1,852 Originally Posted by ynot I answered your question. Now it's your turn . . . No, you didn't actually answer my question. My question was: Originally Posted by Michael C How much "stuff" is there between the Earth and the Sun? You gave an answer that listed some of the things that you consider to be "stuff", but didn't answer my question of "how much?": Originally Posted by ynot It's choc-a-block full of non-material stuff. From time to time there's also some material stuff like a couple of planets, a moon, asteroids, a Space Station, etc. There's also the possibilty of dark matter and anti-matter to consider. The reason I asked you this question is this: you stated that "distance" owes its existence to "stuff", so I'd like you to clarify what you mean by "stuff" and give a way of quantifying it. The question for you is still open: how much "stuff" do you consider to be between the Earth and the Sun? Note that, in order to state how much there is of something, you need to specify a number and a unit. As to your question to me: Quote: Do you think that there is absolutely nothing between the Earth and Sun? The answer is "no".
 30th April 2012, 02:27 AM #158 keyfeatures Critical Thinker     Join Date: Feb 2012 Location: My head Posts: 420 Originally Posted by Michael C The question for you is still open: how much "stuff" do you consider to be between the Earth and the Sun? Note that, in order to state how much there is of something, you need to specify a number and a unit. Well everyone knows it's 25.74 million drumboids, or approximately 42 zoundscruths.
 30th April 2012, 02:38 AM #159 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by RobDegraves That's a lot of posts to respond to... stamina is the least of farsight's problems. That is not unusual with cranks... Your response is abusive with minimal physics content. All: please note that JREF suffers something like a "creationist naysayer" problem when it comes to physics. Some people with scant understanding dismiss evidence and explanation and refuse to enter into sincere discussion. Instead they spoil interesting threads with mudslinging. You soon get to know who they are. I can only urge you to give them the attention they deserve.
 30th April 2012, 02:48 AM #160 Farsight Suspended   Join Date: Mar 2008 Location: Poole, UK Posts: 1,957 Originally Posted by keyfeatures This is an interesting pitch for the TSA. The plausibility of the TSA first principles are tested by coupling to fundamental matter. Yang–Mills theory works. I criticize the original form of the TSA since I find that tacit assumptions remain and Dirac fields are not permitted. However, comparison with Kuchaˇr’s hypersurface formalism allows me to argue that all the known fundamental matter fields can be incorporated into the TSA. The spacetime picture appears to possess more kinematics than strictly necessary for building Lagrangians for physically-realized fundamental matter fields. I debate whether space may be regarded as primary rather than spacetime. The emergence (or not) of the Special Relativity Principles and 4-d General Covariance in the various TSA alternatives is investigated, as is the Equivalence Principle, and the Problem of Time in Quantum Gravity. Looks interesting, keyfeatures, thanks, I'll check it out.

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