Presented by Einstein, cosmologists and physicists that I've had conversations with, popularisers of science like Brian Cox, university physics books (some of which make debunked claims about certain experiments proving there is no aether), the people who run physics forums and their squads of attack dogs, etc. I'm talking about the real world situation with SR as it is presented universally. My sister gave up physics in disgust after being taught the SR voodoo at university and went down a different path. On my relativity page, I link to a folder that contains a PM conversation at the top physics forum, and that represents how things actually are - there's an army of enforcers pumping out SR dogma and refusing to allow anyone to frame things through LET in any way, shape or form.Steve3007 wrote: ↑September 9th, 2018, 7:12 pmPresented by whom? I learnt it as part of a general physics education from various textbooks and lectures. Your repeated mis-representations of Relativity do not match the sources of that education. If you're saying that it has also been mis-represented by other people as well as you, that doesn't really change anything.David Cooper wrote:I'm attacking SR as it's presented...
Time: is time a concept or a physical force and can we prove the arrow of time
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
The speed of light relative to the apparatus in a specific direction doesn't change when light bounces off a mirror - it just conforms to the speed of light relative to the apparatus for its current direction. By the way though, if you were to use your experiment to crunch the numbers for different speeds of light relative to the apparatus, you would have to get things right with the final mirror by working out its contracted and effective angle in order to work out where the beam should hit the wall - otherwise you'd calculate that it would hit different points on the wall for different speeds. That means that you can't actually have done it unless you accidentally made some mistake that happened to cancel out the error, so if you still have your working for it, it would be worth looking at it to see how that didn't show up at the time.Halc wrote: ↑September 9th, 2018, 9:12 pmMy amateur experiment with the mirrors had no speed of light relative to the apparatus since the value changed with every mirror used. It seems a pretty meaningless thing to want to measure, when a simple subtraction of known values, (not measured by the apparatus), would do.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
David Cooper wrote:(C) Does the red light pass through that material at a higher speed relative to it than the blue light does?
Steve3007 wrote:No. Unlike for question A, we are now no longer talking about the time taken for the light to pass through the whole ring of material...
I have no way to know what question was intended; only what question was actually asked. I have answered precisely the question that was actually asked and, in that and the previous post, gone into quite a lot of detail to explain how that question can be answered by explaining what it means to measure speed.David Cooper wrote:...you haven't answered the question that was intended...
Yes, and I explained how you measure the instantaneous speed of light. When you do that, by placing two detectors infinitesimally close together, you measure the speed of the light to be c in both directions. I have also explained why the two detectors have to be infinitesimally close together.David Cooper wrote:We are talking about the red light (the clockwise-moving light) moving through/past the material of the ring as a whole relative to that material piece by piece at closest approach.
No. Frames of reference do not talk, assert or misrepresent. They are used by observers to make measurements. As I've said, those measurements of the instantaneous speed of light, measured in the way that I have described, measure a value of c in both directions.David Cooper wrote:Which means that they assert that the speed of light relative to objects asserted to be stationary in that frame is c in all directions...
Frames of reference do not talk, assert or misrepresent. They are used by observers to make measurements.David Cooper wrote:...and yet we know that some of the material in the ring cannot have light moving past it in all directions at c, so some frames are necessarily misrepresenting reality.
Please read at least the introduction to a text on Special Relativity.David Cooper wrote:My argument has no reliance upon Maxwell's Equations at all. They simply have no relevance to it as the only thing they're going to do is conform to all the theories being discussed.
I see. Thank you. What measurement or set of measurements tells you when something is true?David Cooper wrote:"Equally valid" is the relevant wording, and it includes the idea of being equally true - otherwise they are not equally valid.
David Cooper wrote:The claim that all frames are equally valid is part of the mathematics.
Steve3007 wrote:Please show me the part of the mathematics that contains this claim.
No. I am not playing a game. You stated that something is part of some mathematics. I asked you which part of mathematics you are referring to in that statement. Do you know what mathematics you are referring to?David Cooper wrote:ou are playing the same old game of trying to split off the claims that aren't expressed as mathematics to pretend that they are not part of SR...
Please consult the Principle of Relativity and consider what it says. I've already showed you where you can find it.David Cooper wrote:It is if you take the claims generated from different frames to be equally true.
Frames of reference do not talk. They are used by observers to make measurements. Time is the thing that is measured by clocks. Given that obvious fact, consider an observer at position C (carrying a clock, of course). He receives pulses of light from his clock. He decides to call the time between each of those pulses "a second". For every 1 pulse of light he receives from his own clock he receives 2 from the clock at A and 3 from the clock at B. In this context what do you mean, in terms of something that can be measured, by the expression "at the same time"?David Cooper wrote:If you are standing at any location at all and one frame is telling you that clock A is ticking faster than clock B while another frame is telling you that clock B is ticking faster than clock A, how is that not at the same time? These contradictory claims are being generated at the same time at the same place.
Unfortunately simply asserting that will not make it true. I have referred you to sources of information about Special Relativity, in book and internet form, that demonstrate that you have mis-represented it. Your chance to make your assertion true comes if you refer me to a reputable source (not just something that someone down the pub, or in a chatroom, told you) which confirms what you have said about what Special Relativity proposes.David Cooper wrote:This is an example of you telling me I'm wrong when I'm the one who's right (and it keeps happening that way)
No I have not. Please quote the specific place where I said this.David Cooper wrote:You have effectively just told me the a single time is not the same time as itself!
No they do not. Read an introduction to any form of Relativity.David Cooper wrote:An infinite number of frames make contradictory claims (claims can be generated from them) at the same point in space at the same time - absolutely simultaneous according to the rules of any theory of relativity...
Yes it was, in the sentence in which you used it.David Cooper wrote:...but you say "at the same time" is a misuse of language in this context!
You have demonstrated no errors on my part. I have shown you, in black and white, as plainly as it is possible to do, how you have mis-represented the Special Theory of Relativity. I have pointed you to a textbook. I can lead a horse to water but it is beyond my powers to make it drink.David Cooper wrote:You keep trying to make out that I lack competence on the basis of irrelevant gaps in my knowledge, but just stop for a moment and ask yourself why you keep making such huge errors.
No we do not.David Cooper wrote:You are just sticking your head in the sand now. We have different frames making rival assertions...
Is that how you find out what all physics theories are proposing? By asking a random selection of people? Here's a thought: Before chatting about it with people why not read an introductory textbook about it? Just the introduction. Just the basic ideas. Did I mention this before?David Cooper wrote:Practically each person I've discussed SR with has a radically different idea of what SR is, so I go by the most common factors rather than taking any of the extreme views as gospel.
Pleasse, please, please prove me wrong when I told you in this post...David Cooper wrote:I'm attacking SR as SR is presented practically everywhere.
viewtopic.php?p=319412#p319412
...what the basic postulate of Special Relativity is. Show me one part of this "practically everywhere" place that shows me to be wrong in my assessment of the basic, basic first things that the Theory of Special Relativity says.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
Yes, It became a recognized principle around that time, but I don't think either of them first expressed it. As soon as there was any proposal that the Earth was not stationary at the center of the universe, this principle is required. Before that, one might express that one is walking South along the deck of a boat that is sailing North. I'm not sure something like POR was invoked to assure that it was alright to say both points of view were valid.
Einstein definitely had the relational reference when he said it. I don't find it implicit that speed is a property of a thing, because if it was, it couldn't be two values at once.In my view, the claim "everything is both stationary and moving at the same time" is incorrect (regardless of who said it) because it incorrectly implicitly states that "stationary" and "moving" are properties of single, individual objects ("every-thing").
Anyway, David claims that Einstein said that, and he apparently did use those words, but it doesn't come from the published works that make up the theory of relativity.
Sure. Even LET make preferred speed a relation to the local ether, not a property of an object itself.It is part of the definition of the terms "stationary" and "moving" that they are not.
I would have said between the thing with the speed and a frame, which doesn't necessarily need an object that is stationary within it. It does need some object against which the frame can be defined, but the speed of our first object need not necessarily be the speed relative to that object. The second object needs to be a different one because "X is moving in frames where it is moving" is meaningless. It conveys no information.They are properties of the change in the spatial relationship between two objects with respect to time.
AgreeSo the sentence makes a category error. if that sentence said "everything is both stationary and moving at the same time with respect to the aether" then it would not make that category error. But it would contain a logical contradiction. Neither POR nor SR say that.
I hear yaThe sentence "Albert Einstein's theory of relativity says that it is impossible to work out whether anything is really moving or not" is, in my view, the worst one in the passage that I quoted, because it is the most obviously factually incorrect one. Movement is a well defined empirically measurable quantity. There is no theory of physics which states that it is impossible to measure it. It might be possible to forgive these inaccuracies if David didn't then go on the spread them through everything he subsequently says.
I have been taking the stance that SR is about those more advanced things (the implications of fixed light speed). POR (not just SR) asserted what you just quoted, but David interprets that principle as "All inertial reference frames correctly reflect reality" which is an entirely different statement and one which conflicts with his personal interpretation of the geometry of the universe.Anyway, my main aim here, for now, is a simple one. It is to get David Cooper to read enough about Special Relativity to understand what it means when it proposes: "All the laws of physics are the same in all inertial reference frames", and why it proposes that. Never mind the speed of light for now. All his talk about more advanced things, such as the Sagnac effect, are pointless until he's done that.
By all means focus on the trivial stuff. We' seem to have spent pages working out that we agree that light moves at speeds other than c relative to objects in frames where the objects are moving, when that is pretty obvious without having to invoke a fancy example like the Sagnac effect.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
I said it is implicit in the sentence "every-thing is both stationary and moving at the same time". That is why I said that the sentence contains a category error.Halc wrote: I don't find it implicit that speed is a property of a thing, because if it was, it couldn't be two values at once.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
I'm absolutely not focusing on the trivial stuff. I don't regard the foundations of a house to be trivial. I think they're necessary before considering the roof.Halc wrote:By all means focus on the trivial stuff.
As I've tried to point out to David in the clearest way that I possibly can, he has misunderstood and misrepresented the first postulate of Special Relativity - before it gets to any considerations of the constancy of the speed of light. And that basic misunderstanding - those faulty foundations - run through everything he says. Astonishingly, it now seems to be turning out that he hasn't checked the basics of what it says from any sources other than random people he's chatted to. And from that, he seeks to spread his misunderstanding to others. That's why I think it's so important for him to be willing to actually read at least a short, simple text on the subject.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
This question in isolation lacks a frame definition. I had answered yes to this question, but only with a qualification that it was the frame of the axis of rotation being used. The material is moving at a constant speed in that frame.David Cooper wrote: ↑September 11th, 2018, 5:23 pm (C) Does the red light pass through that material at a higher speed relative to it than the blue light does?
Try as I might, I cannot parse this train wreck of a sentence. The first part talks about the ring as a whole, but the second part talks about one small piece of it, and asks how the red light moving through the whole relative to the piece? It just doesn't parse.We are talking about the red light (the clockwise-moving light) moving through/past the material of the ring as a whole relative to that material piece by piece at closest approach.
If you're asking in terms of the frame of the piece, both beams move at c in opposite directions relative to the material that is momentarily stationary in that frame, but the sentence above doesn't really convey that.
Your arguments have been at times based on this language choice of frames making assertions, rather than on theories making assertions about frames. So this is very much a valid point Steve is making. Frames don't assert things. You manipulate meaning with all these conveniences you presume. Say it correctly when your correctness is being questioned, which it very much is.Statements can be generated from frames by following the rules about how frames work, so all such statements can be described as assertions made by those frames. This is a convenient way of reducing something long-winded to something compact and clear.Frames of reference don't talk.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
Another contradition.David Cooper wrote: ↑September 11th, 2018, 6:08 pm Practically each person I've discussed SR with has a radically different idea of what SR is
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I'm attacking SR as SR is presented practically everywhere.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
viewtopic.php?p=319310#p319310David Cooper wrote:Presented by Einstein, cosmologists and physicists that I've had conversations with, popularisers of science like Brian Cox, university physics books...
viewtopic.php?p=319412#p319412
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
Indeed it varies a lot, but the same end result comes out of each frame's analysis of this, showing one lot of light to have passed all the material at a higher speed relative to it than the other lot of light. In some frames, the speed of both lots of light relative to the material can actually be measured as <c rather than having one lot being measured at >c relative to the material, but that still proves that the speed of light relative to some of the material must be <c in some directions, and by extension that the speed of light relative to that material in the opposite direction must be >c.
I did on the other forum, but I also made it clear that any frame will do.You never specified a frame.
The only need of the sectors is to force the ring to be measured on the right basis, banning the result that I want to show from it from being hidden by averaging it away by including relative speeds between the light and other parts of the ring away from where it currently is.Now that you have, the ring need not be divided up. Each one of them yields the same delta-speed value for the red beam and a different one for the blue beam, but dividing up is necessary to express the varying delta-velocity value around the ring.
(Remember too that this whole thought experiment is only needed to show people that the rules of frames work the way I say they do on one crucial point - that you aren't allowed to pass off frame B measurements of the speed of light relative to objects at rest in frame B as frame A measurements. That's all it's for, so there shouldn't be any need to spend a lot of time exploring it if you aren't guilty of that crime. It's only needed when dealing with people who cheat.)
I bring up the contraction issue just so that people can see that length contraction has been taken into account and that it doesn't break the argument. It's also useful to have the emitter/detector end up at the same side of the ring as it started on at a point when both lots of light arrive back at it simultaneously so that there's no complication in frames where that makes a difference to the lengths of individual cases of the light going from emitter/detector to emitter/detector - that can vary considerably, but all the variation cancels out on average at times when the two lots of light return simultaneously with the emitter/detector back on the side of the ring it started from.That's fast. You have a ring dilation of 4/5 to contend with. Either the ring got smaller or you will need to add more material to it. Maybe it doesn't matter. Either way, the one beam hits the detector 4 times as often as the other, same as what Newton says.
No - there's no frame switch there. The ring is rotating in the frame we're using, and the sectors are going round with it.Now you're switching frames mid-example. One frame has become 100 of them now, despite your lack of use of the plural.Yes - each sector is moving through the frame that we're using, and light always moves at c through this frame, as the rules demand.
I'm not using the local frames of the sectors at all - I'm merely using these sectors to prevent the measurement being made on a different basis where the speed of light relative to the material of the ring at any moment is averaged for all the material of the ring rather than just the material of the sector in which the light is at that time.But I see in the rest of this post that you don't do anything with these little measurements. You just sort of let it drop, so I don't so the point in bringing it up in the first place. Yes, these little local frames have both beams moving at c through the momentarily stationary material.
The way SR is disproved is the way that all the models that are recognised as SR have faults which invalidate them, and Sagnac/MGP's role is in providing proof that my thought experiment is valid, which in turn proves that frames work by the rules I claim of them, which proves that SR generates contradictions which invalidate some models of it (while the remaining SR models are invalidated in other ways). Of course people may make incorrect guesses as to where I was going with the claim, but that's fun because it triggers them to go on the attack, giving me the opportunity to show that my claim (which is not the claim they may have misinterpreted it as) is correct. I do that a lot on forums, tempting people with things that look like easy targets to shoot down, and then I show that what I said stands.That wording carried an implication that the effect was some sort of falsification of SR since it doesn't predict it, that it perhaps denies this relative speed of two moving things at > c. ...
There's no straw man there - there's no point in pretending there's a speed of light involved if it reduces all paths to zero length. There is only a speed of light in 3D models.If I parse this statement correctly, that is the straw man that steve is talking about.The reference to it not being Minkowski Spacetime is there simply because if you use that you're dealing with different models where light has no speed because it reduces all paths to zero length.
It doesn't have to - all frames are simultaneous where you are, and they are making contradictory claims about what's going on elsewhere. Those contradictions are made at a single moment in time at a single location (here), and it doesn't matter what's going on elsewhere other than that whatever might be going on at any other location has to be one thing or another thing and not both at once. The claims about what's going on at other locations are claims tied to now, here, and they contradict each other about what's currently going on there. If one claim's true, the other (which contradicts it) is necessarily false.The 3D interpretation of SR makes no assertions that events in a moving frame are simultaneous with the current time.
The only way to remove the contradictions is to accept an absolute frame, but 99.9% of the people out there in the real world who push SR will tell you that it's banned outright in SR.That such frames are valid or not I suppose depends on one's definition of valid. I've seen you use the phrase 'corresponding to reality', so no, those other frames do not correspond to the ordering of events in reality. The 3D interpretation requires two things: A preferred frame (which GR has, so it is actually pretty hard to avoid), and a preferred moment, which not even LET asserts. The 3D model simply asserts that physics works unchanged in these other frames.
It's not a straw man when that's exactly how they behave - even when the object is moving through the frame they're using, they still assert that the real speed of light relative to that object is c in all directions and that the measurements of its speed relative to that object in the current frame cannot be regarded as valid because whenever you try to measure the speed of light relative to you you determine it to be c. That is the game they play time and time again almost everywhere. That is the reality of what is being pushed relentlessly on forums by hordes of people who've been taught SR in universities and who have become house trolls on physics forums, often backed with moderator status.Straw man. This is false in any frame where said object is not stationary. If they say this, they're implying the frame where the object is stationary, as I have previously assumed you've been doing when leaving frame references off your statements like you did just there.People typically assert that the speed of light relative to object A is c in all directions
Well, there's a major education task that needs to be done to put people right, because you're a very rare example of someone who gets that point right.Again, only relative to that different frame, not to object B, and only that light will be measured thus in that frame.and then they switch frame to assert that the speed of light relative to object B is c in all directions
Of course I know what a reference frame is - the whole point is that I keep having to deal with SR enforcers who don't understand how they work, and it's a hell of a job trying to convince them that they work the way that you and I agree that they work.Do you even know what a reference frame is? It is a relative reference, not an objective one. Any statement about frames is a relative one.and they insist on the frame B claim about the speed of light relative to object B being the correct one for frame A too while rejecting frame A's measurement for the speed of light relative to object B.
Indeed - that is not a contradiction at all. It only becomes a contradiction in cases where a clock is claimed to be ticking faster than another clock that is claimed to be ticking faster than the first and when both are asserted to be true, or where an event is claimed to have happened by one frame and claimed not to have happened yet by another and when both claims are asserted to be true. And it doesn't matter if you claim a theory doesn't make such assertions about two contradictory things being true (even though that dogma is strongly attached to it) - the truth of the claims has to be considered regardless, and when they force an absolute frame to be accepted, that reality should be accepted and acknowledged, while all the mis-educators should be told in no uncertain terms that they need to disown SR's metaphysics (the irrational dogma) and stop trying to force it on everyone. I see a major mismatch between the real world in which the dogma is pushed relentlessly and the way you're presenting SR.It simply is not contradictory for me to be stationary relative to my laptop here yet be moving relative to a bird flying by, but you seem to be asserting exactly that here. I make no claim about actual objective speed of anything when saying those things.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
It does if the apparatus is moving. The mirror changes the direction of the beam. We were considering the thing in a frame where it was going at .866c, so with light defected into the direction of travel, the beam was only outrunning the machine at .134c in that frame, and the return light came back with a delta-speed of 1.866c. That's a big change in relative speed.David Cooper wrote: ↑September 11th, 2018, 6:28 pm The speed of light relative to the apparatus in a specific direction doesn't change when light bounces off a mirror
Yes, we did all that in the post discussing the details. If it hits somewhere else, you know you did it wrong. I never computed effective angles. I was unaware of the technique. I just did a Lorentz transformation on the stationary depiction of the setup.By the way though, if you were to use your experiment to crunch the numbers for different speeds of light relative to the apparatus, you would have to get things right with the final mirror by working out its contracted and effective angle in order to work out where the beam should hit the wall - otherwise you'd calculate that it would hit different points on the wall for different speeds.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
That is unfortunate - other people interpreted it the way it was intended (which misled me into thinking the wording was adequate), but I apologise for it not being clear enough for you.Steve3007 wrote: ↑September 11th, 2018, 7:04 pmI have no way to know what question was intended; only what question was actually asked. I have answered precisely the question that was actually asked and, in that and the previous post, gone into quite a lot of detail to explain how that question can be answered by explaining what it means to measure speed.
And that isn't the measurement being asked for.Yes, and I explained how you measure the instantaneous speed of light. When you do that, by placing two detectors infinitesimally close together, you measure the speed of the light to be c in both directions. I have also explained why the two detectors have to be infinitesimally close together.David Cooper wrote:We are talking about the red light (the clockwise-moving light) moving through/past the material of the ring as a whole relative to that material piece by piece at closest approach.
I have already made if fully clear what I mean when I talk about frames making claims, so stop playing this stupid game of pretending you don't know that it's short for a lengthy description which would double the length of every post if I had to keep using that instead. The claims are generated from frames by applying frame rules, and in each case they are the only valid claim that can be generated from that frame about a specific point. It is absolutely unacceptable for you to keep objecting to my usage of that wording when it has been fully explained and is fully correct. If a frame shows the speed of light in a particular direction being >c, it is thus an assertion of that frame that the speed of light in that direction relative to that object is >c. It is ridiculous that you keep objecting to this.No. Frames of reference do not talk, assert or misrepresent. They are used by observers to make measurements. As I've said, those measurements of the instantaneous speed of light, measured in the way that I have described, measure a value of c in both directions.
And when observers make their measurements, they are forced to produce claims for the frame.Frames of reference do not talk, assert or misrepresent. They are used by observers to make measurements....and yet we know that some of the material in the ring cannot have light moving past it in all directions at c, so some frames are necessarily misrepresenting reality.
Show me a point where my argument is broken by using by Maxwell's Equations. They are irrelevant to it.Please read at least the introduction to a text on Special Relativity.My argument has no reliance upon Maxwell's Equations at all. They simply have no relevance to it as the only thing they're going to do is conform to all the theories being discussed.
Any that tell you when something is true, but that's irrelevant to the issue here - what counts is two contradictory things (contradictory in that they cannot map to the same underlying reality) cannot both be true.I see. Thank you. What measurement or set of measurements tells you when something is true?"Equally valid" is the relevant wording, and it includes the idea of being equally true - otherwise they are not equally valid.
It's in the dogma that's glued to the theory.No. I am not playing a game. You stated that something is part of some mathematics. I asked you which part of mathematics you are referring to in that statement. Do you know what mathematics you are referring to?
The Principle of Relativity doesn't negate the dogma that's glued to the theory. What you're trying to do is disown the dogma and pretend it has nothing to do with SR, but the rest of the world doesn't know that.Please consult the Principle of Relativity and consider what it says. I've already showed you where you can find it.
That's a dud argument. You lose every time you make it.Frames of reference do not talk.If you are standing at any location at all and one frame is telling you that clock A is ticking faster than clock B while another frame is telling you that clock B is ticking faster than clock A, how is that not at the same time? These contradictory claims are being generated at the same time at the same place.
If you use one frame of reference and it tells you that a clock is ticking slower than another clock, and then you use a different frame of reference and it tells you the opposite, they are telling you contradictory things at the same time.Time is the thing that is measured by clocks. Given that obvious fact, consider an observer at position C (carrying a clock, of course). He receives pulses of light from his clock. He decides to call the time between each of those pulses "a second". For every 1 pulse of light he receives from his own clock he receives 2 from the clock at A and 3 from the clock at B. In this context what do you mean, in terms of something that can be measured, by the expression "at the same time"?
It doesn't have to make it true because it already is true.Unfortunately simply asserting that will not make it true.This is an example of you telling me I'm wrong when I'm the one who's right (and it keeps happening that way)
I'm going by things that a lot of professional physicists have asserted. But again, I remind you that regardless of how much you try to disown the dogma that's attached to SR, what I'm saying is valid - the contradictions disprove the models that generate them and force you to move to other models if you don't want to be irrational, and those other models demand either that you accept an absolute frame or the addition of another type of time.I have referred you to sources of information about Special Relativity, in book and internet form, that demonstrate that you have mis-represented it. Your chance to make your assertion true comes if you refer me to a reputable source (not just something that someone down the pub, or in a chatroom, told you) which confirms what you have said about what Special Relativity proposes.
I said: "The contradiction only appears if you assert that clock A is ticking more rapidly than clock B and that clock B is ticking more rapidly than clock A at the same time."No I have not. Please quote the specific place where I said this.You have effectively just told me the a single time is not the same time as itself!
You replied: "That assertion is not made and the expression "at the same time", in the context of that sentence, is a misuse of language. This is an example of you mis-translating the Theory of Relativity, as I mentioned previously. You have therefore not collected all the knowledge necessary for the argument."
Do you imagine that the clocks exist successively and never overlap temporally? They both exist at the same time, and both of them are ticking. One of them may be ticking faster than the other, but if so, the latter is not ticking faster than the former too. At any moment in time during the overlap of existence between these two clocks, statements can be made about the rate of their ticking relative to each other at the same time. One frame of reference is continually claiming that clock A is ticking faster than clock B, and another frame of reference is continually claiming that clock B is ticking faster than clock A, and these frames can go on making those claims for years. At any moment in time during those years, those claims are being made by those frames (at the same time).
Wrong yet again. What I said is correct. An infinite number of frames exist at any point at every moment, and none of them agree on the speed of light relative to an object in all directions. None.No they do not. Read an introduction to any form of Relativity.David Cooper wrote:An infinite number of frames make contradictory claims (claims can be generated from them) at the same point in space at the same time - absolutely simultaneous according to the rules of any theory of relativity...
You're just repeating the error. See above.Yes it was, in the sentence in which you used it....but you say "at the same time" is a misuse of language in this context!
You're making errors over and over again!You have demonstrated no errors on my part.David Cooper wrote:You keep trying to make out that I lack competence on the basis of irrelevant gaps in my knowledge, but just stop for a moment and ask yourself why you keep making such huge errors.
You are completely ignoring the dogma that's tied to the theory. As I keep saying though, that's fine - I'm happy if you want to get rid of it. There's a world out there that needs cleaning up, because the dogma dominates it.I have shown you, in black and white, as plainly as it is possible to do, how you have mis-represented the Special Theory of Relativity. I have pointed you to a textbook. I can lead a horse to water but it is beyond my powers to make it drink.
We ruddy well do. Every time you go into denial over it, you drag the dogma straight back into play because you reveal that you haven't really disowned it at all. You actively cling to the ridiculous toleration of contradictions.No we do not.You are just sticking your head in the sand now. We have different frames making rival assertions...
I remind you that the above followed on from this exchange:-
And there's absolutely no misrepresentation of it on my part - these contradictions exist whether SR acknowledges them or not (and whether the dogma is accepted or denied), and they invalidate some of the models. If you want to settle this point to the satisfaction of both of us, it's simple. Just tell me whether you think mode 2 models (3D and 4D versions including block and non-block versions) are valid or invalid and then it'll be crystal clear whether the dogma is in or out. If you reckon they're still valid, then you're clearly tied to all the dogma that you claim isn't SR. If you reckon they're invalid, then we've made some real progress in eliminating some key SR models, and that's precisely what my argument is designed to do - it forces people to abandon the witchcraft and whittle things down to the viable.The above is a mis-representation of the accounts of ST and TT, similar in form to your earlier mis-representationEither way though, these observations produce contradictions and both accounts cannot be correct (that ST's clock is now ticking faster than TT's clock and that TT's clock is now ticking faster than ST's clock at the same time). It's really straightforward stuff and I can't see why you have so much difficulty with it.
I judge by all the sources, including the textbooks.Is that how you find out what all physics theories are proposing? By asking a random selection of people? Here's a thought: Before chatting about it with people why not read an introductory textbook about it? Just the introduction. Just the basic ideas. Did I mention this before?David Cooper wrote:Practically each person I've discussed SR with has a radically different idea of what SR is, so I go by the most common factors rather than taking any of the extreme views as gospel.
You simply don't describe reality. The dogma is so all-pervasive that it's ridiculous to pretend that it isn't there. It's influence on you is clear too from the way you refuse to see manifest contradictions.Pleasse, please, please prove me wrong when I told you in this post...I'm attacking SR as SR is presented practically everywhere.
There's no point in trying to claim that that's all there is to SR - the dogma is superglued to it, and if you, someone who claims the dogma isn't anything to do with SR, are determined to ignore contradictions and want to pretend that mode 2 models are viable, then you demonstrate that you've either secretly bought into all the dogma and you're not being honest about it or you're blissfully unaware of how much it has influenced you.viewtopic.php?p=319412#p319412
...what the basic postulate of Special Relativity is. Show me one part of this "practically everywhere" place that shows me to be wrong in my assessment of the basic, basic first things that the Theory of Special Relativity says.
- Halc
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
This seems like it cannot work. What possible purpose can be served by this infinitesimal proximity? Why not put the detectors a kilometer apart (or use separate clocks a billion km apart like they did with the earliest measurements? Putting them close just means you need insanely accurate timings to measure the short duration, and you still need to assume a frame to sync the detection events either way.Steve3007 wrote: ↑September 11th, 2018, 7:04 pm Yes, and I explained how you measure the instantaneous speed of light. When you do that, by placing two detectors infinitesimally close together, you measure the speed of the light to be c in both directions. I have also explained why the two detectors have to be infinitesimally close together.
I think I missed the post where you described this in more detail. You're clearly referencing an earlier post.
- Halc
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
Poor wording, my bad. Foundational is much better.
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Re: Time: is time a concept or a physical force and can we prove the arrow of time
I think this is one the problems with this kind of forum in which everyone adds posts at a different rate. If you make a point in one post that relies on things that you said in previous post, somebody reading just the later post doesn't know what you're talking about.Halc wrote:This seems like it cannot work. What possible purpose can be served by this infinitesimal proximity?
I started with a s dicussion about the concept of limits, here:
viewtopic.php?p=319267#p319267
In a nutshell, my point is this: When you discuss the Sagnac Effect with David from the point of view of an observer stationary WRT a non-rotating inertial reference frame, only considering measurements made WRT that frame, you are right to point out that it can be visualized using classical physics. Measured by that reference frame, the path lengths for the two beams of light are different, so it's hardly surprising that the detector indicates to you that the two beams finish their journeys at different times.
I think this can be seen most clearly if we replace the fibre optic cable with mirrors placed regularly around the circle's circumference and then allow the number of mirrors to increase. In the limit, we have a rotating cylindrical mirror with an emitter/detector fixed to its inner surface. But a moment's thought about that setup shows that the effect would be identical if the cylinder wasn't rotating and the emitter/detector was simply moving round inside it. Or if the cylinder was rotating at any arbitrary speed. In all cases, any measurement of the speed of light using that stationary reference frame will yield c relative to the observer. The point that David seems not to recognize is that it is the speed of light as measured by a non-accelerating observer that is constant. Clearly, from that observer's point of view, we could spin that cylinder at any speed we like, including zero, and it wouldn't affect this result. It's the rotational speed of the emitter/detector that counts.
Where Special Relativity comes in, and where my discussion of infinitesimal's comes in, is when we consider the speed of light from the point of view of an observer riding around that circular path - either sitting on the fibre optic cable or sliding around the inside of that cylindrical mirror at the same speed as the emitter/detector. That observer is accelerating towards the centre of the circle so is non-inertial but what I was trying to show in my previous posts is that in the limit of him measuring the speed of light over a section which is very small compared to the entire circumference of the circle, he still measures the speed of light as c in both directions. As I said in the earlier posts, the Michelson–Morley type experiments actually replicates this scenario to a reasonable degree of accuracy if we consider the Earth's orbit around the Sun to be the circle and the measurements of light speed in the experiment to be over a distance which is very small compared to the circumference of the circle.
The reason I invoked the measurement of light speed by an observer riding round the circle is because that is what a literal reading of this question demands:
Given that the way we know the speed of something is by actually measuring it, asking for the speed of light "relative to the material" can, as far I can see, only sensibly mean embedding two detectors in the material. But if we now consider our original emitter/detector riding around the circle, the path of the light that it is measuring is clearly not small compared to the circumference. It is the circumference. So the instantaneous inertial reference frame argument can't be applied. The instantaneous local speed of light is not being measured.(C) Does the red light pass through that material at a higher speed relative to it than the blue light does?
If you think I've got anything wrong here, let me know! It is most certainly possible.
(Note: WRT means "with respect to")
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