Relativity and simple algebra II

Discussion in 'Alternative Theories' started by ralfcis, Feb 6, 2021.

  1. James R Just this guy, you know? Staff Member

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    ralfcis:

    Here is an interesting "Loedel diagram" that you posted in post #49:

    Here, your "Loedel lines" connect the "proper times" in Bob's and Alice's frames for the twin paradox scenario.

    Now, I notice that up until t=t'=4, the Loedel lines are all parallel. They just connect points that have the same numerical value for t and t'.

    But after Alice turns around at t'=4, the Loedel lines continuously tilt over, until Alice and Bob meet up again at t=10 (t'=8).

    Could you please show me how you have calculated one of those "intermediate" Loedel lines?

    For example, there is a Loedel line connecting t=6 to t'=5. Those are not times of "equal proper time" or anything like that, so why are those two coordinates connected? Can you please show me your calculation?

    We could pick any of the other points. For example, t=8 is connected to t'=6, and t=9 is connected to t'=7. But why? How? Where's the maths that shows which t values needs to connect to which t' value?

    Also, I take it that you are claiming that, for example, t=6 is "Loedel simultaneous" with t'=5 and that t=8 is "Loedel simultaneous" with t'=7. How is that shown mathematically?

    I realise I've probably asked the same question twice. This should be easy enough to answer, I suppose.
     
    Last edited: Feb 25, 2021
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  3. ralfcis Registered Senior Member

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    Sure the math's in the diagram in post #48. Look at the return line .6c. There are thin 1/3c lines intersecting that return velocity at times 6, 5.5, 5, 4.5. This is the bulk of my math and takes scads of math pages to explain. It shows how Alice ages slower in proper time than Bob during the imbalance of velocity and how that permanent age difference is established long before the two co-locate. But you'll have to wait for that full disclosure or go to my former forum and read it there.

    You won't find anything like this in SR because SR forbids the mathematical investigation of how permanent age difference progresses before co-location of the clocks because perm age diff can only exist during colocation by definition. This math took years to develop.
     
    Last edited: Feb 25, 2021
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  5. James R Just this guy, you know? Staff Member

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    ralfcis:

    Reading your responses in posts #217-219, I think one thing we need to be clear about is the difference between the time that a specified event occurs somewhere in a reference frame (as measured on one of that frame's synchronised clocks which is essentially at the location of the event) and the time that a specific observer located elsewhere in that frame sees light from that event. Obviously, those aren't the same thing, because in the second case the time will depend on two pieces of information: when the event happened in that frame, and how long it would take light to travel from that event's location to the location of the observer.

    Special relativity is formulated to described the time that events actually occur in different reference frames. A reference frame is kind of a "bird's eye view" of space and time in a particular frame, which allows us to "instantly" record the times and locations of events in that frame. In practical terms, you can imagine an infinity of observers, with each one located near a particular "grid point" in the coordinates of the reference frame, who writes down the time of every event that occurs at that grid point, based on the reading on the clock located at that grid point.

    For this to be useful, we need some way to guarantee that the clocks at all grid points are synchronised in the particular frame. That is the point of the Einstein synchronisation method.

    As a matter of practicality, no single observer at one grid point in a reference frame can ever have an instantaneous view of the whole of spacetime. At best, if they want to know about some event that is happening "now" but at some distance away from them, they will need to wait to receive information in the form of a light signal from the location of that distant event. But in all the scenarios we're discussing here, all the infinity of observers on the grid can gather their own information about events, and we can assume they can all come together with their notebook records at some later time to compare notes at a single location. That "comparing of notes" is what allows us, after the events have concluded, to draw a Minkowski diagram showing all relevant events and the time they occurred in that frame. But the diagram itself shows us the locations and times of the events, unaffected by any signalling delays.
    ----

    In the twin paradox example, you have at various points talked about a "velocity imbalance" that occurs when Alice turns around. Your point is that Bob, sitting on Earth, can't know that Alice turned around until light has has sufficient time to travel to him from the location where Alice turned around. So, you say that Alice knows she turned around long before Bob knows.

    There's nothing wrong with that, but in the Minkowski diagram we can read off the actual time, in Bob's frame, that Alice turned around, not just the (later) time when Bob (sitting at x=0) found out that she turned around. In fact, if Bob had a continuous video feed signal from Alice, he could simply subtract off the light travel time from the time he watched her turn around, to deduce the time that Alice actually turned around. He'd have to know, independently, how far away from him she was when she turned around, of course, but that's not a problem. We can assume space is filled with rulers that Bob can use to measure distances.

    You have said that at certain times Alice says she is travelling towards Bob, while Bob says she is travelling away from him, and similar comments, so that they don't always "agree" on their relative velocity. I say that's wrong. If we look along any one of Bob's lines of simultaneity (not "Loedel" lines, but actual lines of simultaneity for Bob), then whenever Alice was travelling towards Bob, in Bob's frame, Alice would agree that she was travelling towards Bob. The same thing applies if we use Alice's lines of simultaneity, in her frame.

    There is no "time lag" in which the relative velocity changes for one of the two observers but not the other. Not when we use actual notions of simultaneity.

    I can understand how your "Loedel simultaneity" concept might be confusing you, on this point.
     
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  7. ralfcis Registered Senior Member

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    Show me what you're putting into my mouth. Those perspective times from Bob to Alice during the velocity imbalance mean nothing because Bob has no way to know whether Alice has kept on going at .6c or made an infinite number of changes after 3ly separation. How do you figure Bob can in any way determine that? Because you see a line with a forced time stamp on it to infinity? Does he somehow get his info through entanglement or telepathy? Think about what you're saying and how physics works. The information gets delayed by light speed. You somehow believe if you had a line of sync'd satellites all the way to the sun that that would somehow relay a message in advance that the earth is immediately doomed if the sun went out.

    You act like I have no coordinates because I don't use Lorentz transforms. This is not a thread about SR which you keep pushing as the only humanly imaginable solution, this thread is about relativity and algebra. I'm not the one confused. Where, specifically are you having problems understanding.
     
  8. James R Just this guy, you know? Staff Member

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    ralfcis:

    A few comments on your post #217:
    I don't agree with you that there is ever a "relative velocity imbalance period", frame jump or not. Not if we use ordinary notions of simultaneity (i.e. two events happening at the same time, in a particular frame). You're only having this problem because you're insisting on using the imaginary notion of "proper time simultaneity", which is a physically meaningless concept.

    You have two frames. You just choose to draw a diagram for only one of those two frames.

    It's just like that. You translate time coordinates using your "main equation", which is really just the SR equation for the spacetime invariant length. You use SR's Lorentz factor to scale your time axes. Every time you use $\gamma$, you're borrowing from SR.

    What are the coordinates x and t, if not spacetime coordinates? And what is t', if not a time coordinate for a different frame?

    All time dilation is "perspective time dilation". The word "perspective" isn't really required. You can just call it "time dilation".

    Okay. I'm interested to see how it does that, mathematically. That was my question from a previous post.

    Okay. I'll be interested to see how you calculate that "migration".

    No. That's not a requirement. If I draw a MD showing my worldline sitting in my chair in front of the computer, and the worldline of the door a few metres away from me, starting from "now", those worldlines will be parallel, until one of us moves.

    Yes it can. That's no problem. You can draw a MD showing Alice heading away from Bob for a certain distance and then stopping relative to Bob. Alice's worldline, in Bob's frame, will be a sloped line that becomes vertical at the instant that Alice stops moving relative to Bob.

    I don't understand what you're saying, there.

    SR doesn't require "clock co-location".

    No. Proper time (time measured by a clock in the frame where the clock is stationary) is never observed to speed up or slow down.

    I don't know why you think SR has any such "rule".

    That's all a bit muddled.

    It sounds like, in that scenario, Alice and Bob never come to relative rest, so they can't meaningfully compare their "permanent age difference".

    It also sounds like Charlie comes to rest with respect to Bob at some point, but you haven't given any information on where Charlie started or how old he was at any particular time in any particular frame.

    I have no problem with people travelling past each other at constant velocity and handing across clock data to one another. If you want to analyse a specific scenario of that kind numerically, we can do that.

    Certainly, it's a mistake if you think SR can't cope with that sort of thing.
    In the twin paradox, Alice's acceleration (turn around) certainly results in an asymmetry between hers and Bob's ages. Is that what you're asking?

    The asymmetry due to the acceleration of Alice (but not Bob)? Yes, that's the cause of the "permanent age difference".
     
    Last edited: Feb 25, 2021
  9. ralfcis Registered Senior Member

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    I've answered these questions, not my problem if you can't accept the answers and want to make this thread about SR. I will continue on from page 7 for previously unanswered questions and then I will continue with the topic of this thread for the next 2 years. Maybe you'll gain some insight over this time period.


    ZZZZZZZZZZ bed time.
     
  10. James R Just this guy, you know? Staff Member

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    Reply to #218:

    The time axis of Bob's frame is the vertical axis of the graph. The "velocity line" you refer to is the time axis of Alice's frame, or Alice's worldline in Bob's frame. Obviously, plotting Alice's worldline in Bob's coordinates does not affect Bob's length units. Alice, of course, has her own length units, but for some reason you don't like drawing Alice's space axis; you only like drawing her time axis.

    Well, shucks. That sounds a lot like a length contraction effect at work, there. Fancy that.

    It doesn't matter if you don't choose to consider lengths in Alice's frame. They don't go away just because you choose to ignore them.

    I'll wait to find out how you calculate the gradual increase in the slope of your Loedel lines.

    The "instantaneous" part is only due to the assumption that Alice accelerates instantaneously. In reality, Alice could not have infinite acceleration, so the "swinging" of her notion of simultaneity would happen more slowly.

    The other stuff, about Alice perceiving Bob's future, etc., is muddled. We're talking about the particular set of events that Alice considers to be simultaneous in her frame, at any given time. Bob's frame is separate from that, and Bob's perception, as an observer in that frame, will obviously differ from Alice's.

    In terms of what Alice would see if she looked over at Bob during the turnaround, she would see Bob's clocks ticking much faster than her own, for a time. After the turnaround, Bob's clocks would appear, once again, to be ticking slower than hers, as before. On the other hand, what Bob would see, watching Alice's clocks as she turned around, would be her clocks ticking much slower than his, during the turn. In other words, for him, it would look like she was sort of "frozen in time" for a period of time at the turnaround point.

    Interesting. Earlier you were recommending Greene's videos for learning relativity. Now you seem to think he's full of errors.

    In principle, I could show you. If I used the Rindler metric, I doubt you'd understand the explanation. Alternatively, I could use an integral technique, but that would involve calculus. Either way, it would involve a fair bit of work for me, with minimal chance of useful payoff, as far as I can tell.

    Proper time is in no way absolute.

    Even in the twin paradox scenario, Alice's proper time on the "outward" journey is different from her proper time on the "return" journey, because she accelerated in between those two parts of the journey. Her clocks, to her, appear to tick away merrily at their usual rate, throughout, of course. Alice was in two different frames of reference (two different states of motion) relative to Bob, for the outward and return journeys.

    A more accurate thing to note is that all observers, in whatever frame, agree that Bob remained in an inertial frame of reference at all times, while Alice spent some time in non-inertial frames.

    See one of my recent previous posts for a discussion of light signalling delays and the times that events actually occur. There is never a need to "instantaneously establish" things. We can keep records and refer to them later.

    Yes there is. That would just be the regular notion of present simultaneity. (We're assuming, I suppose, that the Sun just mysteriously vanishes - here one minute, gone the next.)

    No. The "subjective perspective" you're thinking about there is the one where we have to wait for light signals to reach us in order to get information about events that have happened "elsewhere". SR is mostly concerned with events in spacetime - i.e. with the times that events actually happen, rather than the times when some particular observer somewhere becomes "subjectively aware" of a distant event happening.

    Try to be clear about what you're talking about.

    If the Sun vanishes right now, then it will really vanish right now. I won't be aware that it has vanished until I see darkness 8.5 minutes from now, but that is irrelevant to the fact that the Sun is actually vanishing now.

    A few days ago, the Perseverence rover landed on Mars. Controllers at NASA watched nervously as it completed its last 10 minutes of entry into the atmosphere followed by the landing, then applauded when they knew it had landed safely. But there is 20 minute light delay between Mars and Earth, so while they were all nervously wondering whether it had landed safely, in fact the rover had already been sitting on the Martian surface for 10 minutes or so.

    It would be silly to say that the rover had not really landed until we, on Earth, saw it land. We're aware of the signalling delay, so we can just backtrack the times of events on Mars by 20 minutes, to work out when they actually happened.

    I don't know what "different results" you might be referring to, so I can't really comment.
     
  11. James R Just this guy, you know? Staff Member

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    Reply to #219/220:

    The Doppler shift, in relativity, is partly due to "ordinary" wave effects (as are seen in the non-relativistic Doppler shift formulas) and partly due to time dilation between the "source" and "receiver" reference frames. If it was a simple matter of signalling delays, as you assert, then the non-relativistic formulae would apply, but they don't. We have to take (Einstein's) relativity into account to derive the correct Doppler shift.

    Correct.

    You speak as if there is just one "reality" whenever you use the term "in reality". But relativity is all about what happens in different frames of reference, which are all equally-valid "realities".

    The idea of a "clock rate through time" is a myth - maybe one you picked up from reading Epstein.

    Your statements are not problematic, provided that we understand your "normal clock rate" to just mean the proper time recorded by a clock, or something like that.

    Okay. Obviously that isn't clear from your graphs, but it's not a problem in any way.

    Their relative velocities are always "in balance", in either of their respective frames, at any given time in a single frame. You're just confused because you think you can meaningfully compare proper times in different frames, for spatially separated observers.

    Well, this is interesting. You're denying something that is clearly derivable from the graph that you plotted.

    This is a pretty major point of disagreement. Don't you think that you should explain what is wrong with what I wrote, there, rather than just asserting I'm wrong?

    SR uses well-defined reference frames with rulers and synchronised clocks.

    "Perspective reality" is the reality you live with every day of your life. If you want to call that "boring", I guess that's up to you.

    Alice's so-called "proper velocity", measured in Bob's frame of reference, is $\gamma v$.

    As I explained, that uses Bob's rulers and Alice's clocks. Fundamentally, though, it is a velocity that Bob measures. Without specifying that it's Alice's proper velocity in Bob's frame, the term is meaningless. Alice's "proper velocity" in some other frame will be different from what it is in Bob's frame. In Alice's own frame, her "proper velocity" is zero, of course.

    Essentially, when you measure Alice's "proper velocity", you're always choosing somebody's rulers to measure it with. It's a frame-dependent quantity.

    No. You're confused, again. If I'm standing a mile away from you, you can't know what I'm doing now until - at the earliest - a light signal has had time to travel from me to you. But that doesn't mean that I'm not doing what I'm doing now. Your current lack of knowledge about what I'm doing now doesn't change the fact of what's happening right now where I am.

    Also, knowing that you're a mile away from me, you can take any light signals you get from me and backtrack to work out exactly how long before you received those signals the events actually happened, showing the information in the signals.

    No. Our clocks keep right on ticking, in sync, even though we're separated (assuming we're at relative rest). There's no delay to "reality". There's only a signalling delay related to your capacity to gather information about distant events. While you're waiting for the signal, reality "over there" moves right ahead without you.

    There's nothing artificial about it. The clocks everywhere in the reference frame all display the same time and tick at the same rate, in sync. What's artificial about that?

    Essentially, you're trying to claim that it is impossible to have a synchronised time standard. And yet, there you are, sitting in a time zone somewhere on Earth, with a time that is precisely offset relative to Universal Time (or Greenwich Mean Time), kept by atomic clocks at various locations on Earth, which are all synchronised with one another using, essentially, Einstein's sync method.

    If this timekeeping system didn't work - or was impossible, as you claim - then all kinds of technologies would immediately fail.
     
  12. James R Just this guy, you know? Staff Member

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    So, you have no simple equation for calculating the corresponding t' value for a given t value, in the twin paradox scenario?

    You have to do it graphically, somehow?
     
  13. James R Just this guy, you know? Staff Member

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    Reply to post #224:

    Lines of simultaneity tell us what is happening "now", for either of the two observers (Bob and Alice), with each of them obviously having a different idea of what "now" is (i.e. which set of spacetime events is happening simultaneously "now").

    You're still hung up on matters of signalling delays.

    In a previous post, I discussed in some detail the times when Bob received signals, and therefore knowledge, about Alice turning around. But Bob's knowledge of when Alice turned around doesn't in any way affect when Alice turned around. It was her choice as to when to turn around. Bob finds out about her choice later on, but so what? He can subtract off the signal travel time and backtrack to find the actual time, in his frame, that Alice turned around, if he wants to do that.

    We agree that information available at any given spatial coordinate at any given time is restricted by signalling delays (finite speed of light).

    If you think I have at any point advocated instantaneous transmission of information from one point in space to another, then you have a serious misconception about what I've been saying.
    No. I don't believe that. Please read the post above, where I discussed that example in depth, along with a similar one involving the Mars rover.

    No. I act like you're using three coordinates: one space and one time for Bob, and one time for Alice. At the same time, you're blind to Alice's space coordinate, apparently.

    I agree you don't use Lorentz transformations. At this point in our discussion, I'm not sure you understand what they do.

    You have claimed repeatedly that you only use one reference frame, but clearly you use two separate time coordinates for Bob and Alice, which means two different clocks, at least. In fact, from a formal point of view, you conceptually need a whole set of clocks and rulers to even drawn your "Bob" diagram (MD or "Loedel diagram", whatever you want to call it).

    It has to be about SR, because essentially your "alternative theory" is just a borrowed and slightly mangled version of SR.

    If you really had an alternative theory of relativity, you could present your coordinate transformation equations, or at the very least make a concise list of the actual axioms of your theory. Instead, the best you could manage was a long and muddled set of assumptions about this and that, not obviously tied together by any coherent ideas.

    I think that, at this point in our conversation, I have a very good understanding of your views. Mostly, I'm now trying to show you where you're going wrong. Helpfully, I'm also trying to introduce you to some concise definitions and concepts from SR, so you will hopefully come out with a better understanding of that theory than you currently have.
     
  14. ralfcis Registered Senior Member

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    Yes you should see if your understanding of relativity correlates with his. Yes this thread is about pointing out errors and fixing them but you have to be aware of what needs fixing in the first place. Do you still find this paradoxical after this explanation? I'm just scanning your responses and cherry picking for low hanging fruit. Umm, lowest hanging fruit.
     
    Last edited: Feb 25, 2021
  15. ralfcis Registered Senior Member

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    Maybe to the uninitiated. There seems to be confusion on this forum between numbers and things. Just because things may have the same numbers doesn't mean they're the same things. As I said applying Y to coordinate length as opposed to coordinate time isn't the same thing as actual physical length contraction. In fact, if the SR formula for time dilation is t=Yt' and for length contraction is x'=Yx then my equation uses x=Yx' which is not length contraction. Oh math, always getting in the way of philosophical arguments.
     
  16. ralfcis Registered Senior Member

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    So you're saying
    \((ct')^2 - x'^2= (ct)^2 - x^2 \) is the same thing as
    \((ct')^2 = (ct)^2 - x^2 \)
    Yes, similar letters and numbers so they must be the same thing. I don't know where you get your algebra from because if you reduce the top equation doesn't it become
    \((ct')^2 = (ct)^2 - x^2 +x'^2 \).
    Maybe you can take a few posts to teach me where I went wrong because they don't look the same to me. Just like Yv and v don't look the same to me.

    It's really counter productive to the purpose of this thread to take your statements apart. However, many of your questions are good the first time around so I will continue answering them. Are there any non-philosophers who could participate? Just teasin' ya James, keep up the good work.
     
    Last edited: Feb 25, 2021
  17. ralfcis Registered Senior Member

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    Ok here's an example to showcase how my math can show the progression of permanent age difference due to velocity change and duration of velocity imbalance and how SR can't even calculate it. Alice blasts off at 3/5c, at 1 ly changes her velocity to 4/5c and at 2 ly changes it back to 3/5c never returning to Bob. She's done 3 instantaneous accelerations ( including the one at the start) and SR always claims acceleration's the magic cause of permanent age difference so what's SR's answer? People here deny there has to be co-location of clocks to get a valid answer so I'd love to see someone come up with an answer using SR's math. C'mon experts show me you can do it. I know I can with my math but let me see if my answer agrees with yours. None of you, even if you resuscitate Einstein himself, will get a determinate answer to this question because SR would mathematically self-destruct if it allowed one.
     
  18. James R Just this guy, you know? Staff Member

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    In what respect?

    Why do you care whether I agree with Brian Greene about relativity? Do you care whether I agree with him in every detail, or are you just asking about my overall agreement, or something?

    He's an expert in his field. From what I've read of his, I have no major objections to anything he has written. I'm concerned that string theories and the like are, at present, pretty much untested, so that they are very speculative, even though there's a huge volume of mathematics behind them now. But that doesn't mean I disagree with them.

    If you want to know how well or badly my understanding of relativity correlates with Greene's, you will need to ask me something specific about his views.

    That's part of the problem here. From my point of you, it is because you don't have a good understanding of what relativity is doing that some of your interpretations of its results are wrong.

    Well, you're not doing the maths right, there, exactly. First, you need to be careful as to whether your equations are transforming lengths (i.e. distance intervals) or positions (coordinates in space). Next, you need to be very careful about the relativity of simultaneity in the two frames you're transforming the "length" between. Lastly, and perhaps most importantly, you need to be aware of which frame of the two is measuring the "rest length" ("proper length") of whatever object it is that you're looking at. If you get that wrong, then you'll often get the transformation around the wrong way, too, like you did here.

    Yes. I've posted this many times. If you put $x'=0$, then the first equation reduces to the second, as a "special case".

    The second one is the one you always use. For example, in the twin paradox, it is fine to put Alice at $x'=0$ and leave that as a fixed location in her frame of reference. Usefully, we can then set the clocks in Bob's and Alice's frames to $t=t'=0$ when $x=x'=0$, so that Bob and Alice both have spatial coordinates of zero when their respective clocks read zero time.

    While it is useful to set $x'=0$ in some of your examples, it is not necessary to do that. It's just a choice you make. Obviously, the spatial origin (the point where x=0 or x'=0) in any reference frame is arbitrary.

    Yes, and when $x'=0$, that reduces to what you call your "main equation".

    Does this post clear things up for you? I mean, I've already explained this to you in about 10 previous posts. This one is just a bit more explicit, so I hope it really drives home the point this time.

    They aren't the same. We've already discussed that, too. v is Alice's velocity, measured using Bob's clocks and rulers; Yv is Alice's velocity, measured using Bob's rulers and Alice's clocks.

    We are in agreement on this, aren't we?
    You haven't been specific enough about the question you want answered.

    For example, you might ask something like:
    At time t=?? in Bob's frame, how much time has elapsed on Alice's clocks?​
    or
    When Alice is at a distance of x=?? from Bob (measured in Bob's frame), how much time has elapsed on Bob's and Alice's clocks?
    Tell me what you want answered, and I'll try to give you an answer.

    You need to ask a determinate question before anybody can give you a determinate answer.
     
  19. ralfcis Registered Senior Member

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    Ok you made some very good points and I was way too cocky and I need to go into a lot more detailed explanation.
     
  20. Q-reeus Banned Valued Senior Member

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    ralfcis, I will assume the following two claims quoted below still hold as of p12:

    1: p1 #6 last part: "My math also shows time does not slow in time dilation, it has to do with relativity of simultaneity depending on when the stop watches are started from each perspective. This is just a math exercise, philosophy can be debated but math can't be, it's either right or wrong."

    2: p1 #8 line 9: "Can you please give a specific example of the permanent slowing of time and show your calculations of that. What effect does a permanent slowing of time have on the rest of the universe?"

    I could go on citing but refuse to plow through all of 12 pages of typically loooong posts back and forth. The sort of thing that bores me to tears and indicates discussion has long degenerated into a circular arguing impasse. Which reminds that a word search shows circular motion hasn't been mentioned so far. Let's do that now.
    Observer A motionless in some inertial frame is situated anywhere along the rotation axis of observer B located at fixed radius r orthogonal to it's rotation axis, in a centrifuge circulating at constant angular speed ω, hence constant relative speed relative to A, of |v| = .
    One way of looking at the case is as per first green ticked answer here:
    https://physics.stackexchange.com/q...vistic-circular-motion-in-invariant-spacetime
    It clearly translates to a constant time dilation factor such that as determined by A in the inertial frame of A, B's clock ticks slower than A's clock according to
    dt' = dt/γ - (1),
    with stock standard SR γ = 1/√(1-|v|²/c²), dt' the time interval determined by B after say one complete orbit, and dt the time interval determined by A also for one complete orbit of B.
    The same result obtains by noting A is traveling further through time in it's inertial frame relative to B that as determined also in that frame is traveling further through space thus has less left over for its time component. B must age slower than A according to the usual invariant SR interval.
    Clock readings diverge at an accumulating constant rate. The differing clock rates for circular motion are thus clearly nonreciprocal thus 'absolute' not 'illusory' in contrast to the reciprocal case of constant rectilinear relative motion. This example provides an answer to the first of your questions in 2 above. The second question there is imo moot. And as per p684 in http://www.lightandmatter.com/lmn.pdf, there has long been adequate experimental proof of nonreciprocal time dilation for physical objects in circular motion.

    Your claim in 1 above is therefore also invalidated since nonsimultaneity even if present could at best only add a small and fixed net time differential during startup and/or slowdown. As motion of B is at all times orthogonal to A, nonsimultaneity is entirely absent.

    You further claim iirc that Lorentz length contraction is not real just illusory. Then how do you explain magnetic attraction between two coaxial circular conduction currents circulating in the same sense i.e. both clockwise or anticlockwise? In an inertial frame where both loop currents are stationary, conservation of conduction charge number constrains the situation such that net linear positive lattice charge density equals net linear negative conduction charge density everywhere around both loops. SR requires that situation to fail in the local proper frame of a conduction charge in either loop, where lattice charge density in either loop is locally contracted along the direction of local relative velocity, while conduction charge density is locally lower. As a consequence of that charge density imbalance moving charges are electrically attracted to the other loop. Back in the inertial frame, the attraction is attributed to magnetic Lorentz forces F = qv × B, where B is the locally impinging magnetic field generated by the other loop current. The case is examined pp 689-692 in the article previously linked to: http://www.lightandmatter.com/lmn.pdf
    If length contraction is as you claim not real, how then does your version of relativity explains that situation.

    Please don't respond with any 'but what about....' side-tracking questions. Take some time out to think through the above.
     
  21. ralfcis Registered Senior Member

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    I'll respond to this now since it's easy. I've been hearing whispers of this argument that it's absolute proof for length contraction and recently came across a video about it. But I then found a better video:



    Here's the original video I commented on in another forum:



    My analysis ended with proving this phenomenon can be explained using time only without having to consider length contraction. I hope this answers your question because I just skimmed your question and if this answer doesn't apply I'll look closer into it.
    Some of my questions were specifically addressed. We`d have to go through each scenario (I count about 4) and I promised I wouldn`t do any physics until Dec. I`ll try my best to sneak. The main problem is terminology. Relativity sucks at defining its terms. It refuses to do so and the definitions that you squeeze out of experts (spurts) are ridiculously stupid and well guarded because they're so stupid.



    So first off, what does the guy define as charge? There's no way a magnet is electrically charged with some right handed electrical charge called magnetism. So his example of a current in a wire deflecting a magnet is confusing and irrelevant. Using a cat as a positively charged piece of fluff is also confusing. Is he saying the moving fluff ball being repulsed is the same as a stationary magnet being repulsed? That makes zero sense unless there's something basic I don't understand here. I guess a moving electrical charge generates a magnetic field and that generates the magnetic repulsion from one perspective and electrostatic repulsion that looks the same in another perspective. The analysis of a stationary magnet or fluff ball is irrelevant. The fluff ball must be moving relative to the protons like the electrons are. Is that what I'm missing?



    I hope everyone understands that "length contraction" is due to the relativity of simultaneity of when the clocks of two different frames measure the start and end times of events from their perspective. Since the start and end times are coordinate points, it's ridiculous to equate the duration between those points as some sort of physical length. To say there is actual physical length contraction outside of this definition is having 2 separate definitions for length contraction in relativity. So bringing physical charge density into the discussion is not totally accurate (see below). So let's just tackle these points so we're both talking about the same meaning when we use terms.



    PS. The spacing of the protons doesn't change in either perspective. What changes is that more proton (1.000000001 proton) is simultaneously (using fluff ball clocks) within the same section of wire between two electrons (like the pole in the barn example). More proton charge spends the same time between the electrons according to the fluff ball perspective. It's not a spacing thing but a time thing which makes it look like a increase in physical charge density. Yes I made a mistake in that the fluff ball moving with the electrons is equivalent to the fluff ball and electrons stationary perspective with the protons moving but not equivalent to the fluff ball and protons stationary with only the electrons moving. The last one is equivalent to the protons and fluff ball moving while the electrons are stationary. Thanks Popeye for catching that. I guess if you agree with what I wrote then you did answer my questions. Still no such thing as physical length contraction.
     
    Last edited: Feb 26, 2021
  22. ralfcis Registered Senior Member

    Messages:
    421
    I don't agree with Einstein's definition of the insanity of endless repetition. Sometimes there's a break in the logjam that allows progress. Yes i wanted to write out all my math uninterrupted before the discussion started but this way may be even better for me (but not for the readers). I must address the assumptions that readers have about SR while explaining my new ideas. I thought they were just a continuation of SR but they are completely foreign to it. Without length contraction, there is no SR yet I can explain everything using only Yv not t/Y or Yx (or x/Y depending on perspective).
     
  23. Q-reeus Banned Valued Senior Member

    Messages:
    4,695
    The two You Tube vids you linked to obviously agree with my last example in #237. I doubt any progress will be made, but re your tackling just my second example, how can 'more positive charges exist between two electrons' mean anything other than local length contraction of the positive charge lattice? Especially given we are talking about circular loop currents? And btw there is simultaneously a dilation of negative charge density occurring. All in the proper frame of a moving charge of course.

    And why have you dodged answering the first example of constant circular motion of observer B? Do you accept constantly accumulating differential aging between A and B? Answering in the affirmative your first question in quote 2 at start of #237.
     

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