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Does Special Relativity contain contradictions?

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Tamminen
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Joined: April 19th, 2016, 2:53 pm

Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 2nd, 2018, 1:23 pm

Halc wrote:
October 2nd, 2018, 12:22 pm
Tamminen wrote:
October 2nd, 2018, 12:00 pm
I know all this. What I mean is this: There are these 3 events: (1) the clock in D ticking for 10 years, (2) the clock in T1 ticking for 5 years and (3) the clock in D ticking for 2.5 years.
None of those are events. The 3 events are the D clock reading 10, the T clock reading 5, and the D clock reading 2.5. A 4th event is D clock at 17.5, and 5th event at D reading 20. Those other events have come up. No frame is necessary to specify those events. Not sure if you meant this.
All these events are real. Event 2 is simultaneous with event 1 for D, but not for T1. I just called this 'asymmetry', which was perhaps a misleading expression. 'Asynchrony of clocks' might be better?
But events 2 and 3 are simultaneous in frame T1, so the symmetry is back. Events 2 and 4 are simultaneous in T2, and the same separation as the prior case, so even more symmetrical.
Yes, events are ordered differently in different frames. Relativity is very up front about that. It is symmetrical (else you'd be able to determine the preferred frame), but asynchronous, sure.
I think we have no disagreement, only a small confusion about the term 'symmetry'. I used it in the way it is used in logic, you had physics in mind.

Tamminen
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Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 2nd, 2018, 5:02 pm

Tamminen wrote:
October 2nd, 2018, 1:23 pm
I think we have no disagreement, only a small confusion about the term 'symmetry'. I used it in the way it is used in logic, you had physics in mind.
To clarify this: simultaneity is not a symmetric relation in the logical sense of aRb, because if a is simultaneous with b, b is not necessarily simultaneous with a. Physics has another meaning for the term with all kinds of symmetries in the Standard Model for instance.

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Halc
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Re: Does Special Relativity contain contradictions?

Post by Halc » October 2nd, 2018, 5:11 pm

Tamminen wrote:
October 2nd, 2018, 5:02 pm
Tamminen wrote:
October 2nd, 2018, 1:23 pm
I think we have no disagreement, only a small confusion about the term 'symmetry'. I used it in the way it is used in logic, you had physics in mind.
To clarify this: simultaneity is not a symmetric relation in the logical sense of aRb, because if a is simultaneous with b, b is not necessarily simultaneous with a.
Yes it is.

David Cooper
Posts: 224
Joined: April 30th, 2018, 4:51 pm

Re: Does Special Relativity contain contradictions?

Post by David Cooper » October 2nd, 2018, 5:44 pm

Steve3007 wrote:
October 1st, 2018, 11:54 pm
I'm not really interested in discussing this in terms of model numbers.
That's why you keep making mistakes - you fail to separate out the incompatible models that have been mixed together by the establishment in order to pretend they have a working model. They don't have one though - the best they've got is a block that they cannot generate in a rational way and within which there is no action at all.
For clocks C1 and C2 the experiments are identical because in all experiments they move, relative to each other, in the same way. That's a really simple and obvious fact. There are no contradictions in it. I think the underlying reason why you keep on seeing contradictions where none exist is because you simply refuse to accept that physics is an empirical subject, that statements in physics are only meaningful if they can be related to something that can be measured, that the movements of objects are only meaningful relative to another object and that the tick rate of a clock is only meaningful relative to another clock. Your statements fail to take this into account over and over and over again. The most recent posts of yours, to which I am replying here, will demonstrate this apparent blind spot of yours yet again.
You're simply blind to manifest contradictions because you've been done over by a powerful mind virus, just like religious people who lose the ability to reason.
There is no such thing as an event meshing failure in physics. As I said earlier, that stems from your misuse of the concept of a 4D spacetime graph and the concept of a worldline, and your weird notion (on your website) that these 4D spacetime graphs have to be "built" like some kind of Lego model.
A magic block that was never generated in order of causation is not physics, but pure fantasy. If you're going to have a block universe, you need to grow it in order of causation in order for causality to be real. The models in sets 1, 2 and 3 follow proposed means of doing so, and one of those proposals is that time runs, but never runs slow - that automatically gives you the event-meshing failures in set 1, but your lot play games by mixing incompatible models to try to avoid the unavoidable consequences of trying to run time in that way. None of them have the honesty to admit what happens when they try to run a model with running clocks where none run slow - they find the event-meshing failures, and then they delete their code and pretend it never happened. That's why the only simulation you'll find anywhere on the Web that shows event-meshing failures is mine. If you want to show me I'm wrong, you need to write a program to simulate the same simple event that my simulation covers and show how you avoid event-meshing failures while generating the block. You won't manage it because it's impossible.
I don't know for sure what you mean by "the speed of light relative to the arena", but I presume you mean the speed of light from any light source as measured against the starting-line reference frame. That speed is measured to be constant. The speed of light, as measured against any reference frame is constant regardless of the movement of the light source relative to that reference frame.
Whenever you change frame, you change the speed of light relative to the arena and its content. If you start with the arena's frame and an object at rest in it, when you switch to a frame moving at 0.99c relative to the arena, you now assert that the speed of light relative to that same object as 0.01c in one direction and 1.99c in the opposite direction. If you consider both frames to be telling the truth about the reality as to how fast light is moving relative to the object (i.e. the underlying reality), you have the following contradictions: 1 = 0.01, and 1 = 1.99. (By extension, you also have 0.01 = 1.99.) Those are contradictions that any normal person would recognise, but you've been hypnotised into not being capable of seeing them. If you don't consider both frames to be telling the truth about the underlying reality though, then you accept that they are merely telling you how things appear, in which case you should be free to consider the underlying reality and to wonder what's really going on there. You're stuck though in a place where you are governed by dogma (which you've been programmed to deny) because your ability to reason independently has been destroyed. Maybe religious genes are involved too.
Your problem is that you persist in thinking that if clock X measures the tick signals from clock Y as slower than its own, then clock Y must measure the tick signals from clock X as faster than its own. It doesn't. They each measure the other's as slower. This problem seems to me to stem from your apparent inability to get used to the fact that we have to talk about things in terms of how they can be measured, as stated at the beginning of this post.
You're grasping at straws, inventing errors on my part that don't exist. I'm fully aware that both clocks measure each other as running slow while they're moving relative to each other. What matters is that when they're reunited, one of them finds out that its measurements were misleading because it's recorded less time than the other clock. I know you don't like different models being mentioned, but I have to keep mentioning them to try to help you understand that you aren't allowed to mix incompatible models to crate fake "fixes" for problems that have no solution. The static eternal block models don't run time but rely on magical creation. The models that run time without clocks running slow always create event-meshing failures. In this discussion of contradictions though, we are focused solely on models with running time where some clocks run slow, and the clock that makes two legs of a trip to the one leg of another clock where they start together and are reunited at the end always runs slow on average compared to the other clock. That is the starting point for the analysis, and it severely restricts the possibilities as to what happened to enable that clock to run slow.
for all the details of the relative speeds of clocks 1, 2, 3 and 4. The relative tick rates that each pair of clocks measures depends on those 2 clocks' relative speeds. Nothing else. You can add in as many other clocks as you like, and have them moving around as you like. Adding new clocks doesn't suddenly change the relative tick rates measured between existing clocks. Think about the simple logic of that for a moment.
Of course it doesn't, but when you change frame, you often change key hidden details as to which clock is ticking more quickly than which, and that's where you make your error time and time again. You're blind to it though because you've been taught that this illegal move is legal. It is legal in set zero models because there is no running time there, but it is not legal in set 2 and 3 models. Every time you change frame, you fool yourself.
If both of these experiments are identical, then clock 3 is ticking faster than clock 4 and clock 4 is ticking faster than clock 3, but that's a mathematical impossibility.
I think your failure to appreciate that tick rates are things that are actually measured by comparing pairs of clocks stems from your attachment to some form of universal time, and failure to realize that time is what is measured by a clock. That's my theory anyway. It is the only reason I can think of for your statements.
The failure is all yours, and it comes from powerful brainwashing which has left you incapable of judging what's going on. I've never yet encountered anyone in your position who can be deprogrammed though, which means that you're probably never going to understand your error.
Your assertions do not agree with observed reality.
Fact A: the clock that did two legs ran slow. That's an observed reality - it's the best measurement we have. Fact B: it is mathematically impossible for that clock to have run slower than the stay-at-home clock on average without ticking slower than the stay-at-home clock on one or other of those legs. Fact C: This leads to the conditional truth: if Lorentz's clock ran slower than mine on the first leg, then (when the reverse experiment is carried out at the same time in which Einstein's clock accompanies Lorentz's on the first leg but keeps going (when Lorentz turns back) is later caught by yours when you're racing after it after hanging out with me for a while when L and E set out) we know that your clock ticked faster than Einstein's while you were waiting with me. That is for rational people an undeniable asymmetry. This conditional truth means exactly what it says, and no amount of establishment voodoo can override it.
And that means changing the speed of light relative to the system for each leg, leading to a complete misunderstanding of what's going on.
The speed of light is measured to be the same by all observers. There is no contradiction in that.
There's a ruddy great contradiction there every time you change frame, but you've been hypnotised into not seeing that. This is why I see the establishment as a religious cult. You have been rendered incapable of understanding some of the most basic things in real physics.
The apparent speed of light relative to them in each case is c. The actual speed of light relative to them may be different for each.
I don't know what you mean by "the actual speed of light". If you're not talking about something that can be measured you're not doing physics.
No - I'm doing physics, while you're inadvertently doing witchcraft instead. You're allowing yourself to be misled by measurements made using different frames which you naively take at face value. The existence of the underlying reality is revealed by a clock running slow after going on a journey and returning. It runs slow on average, but you switch frame between making measurements and believe that it's always running at full speed while all other clocks are magically running slower unless they're co-moving with yours. You are incapable of recognising the mathematical necessity for your clock to run slower than the stay-at-home clock on at least one of the two legs of your trip, and that's sad. I don't know how so many people are so susceptible to such brainwashing, but it is so common that it is very much the norm. Perhaps it's something genetic that predisposes people to become victims of this, because we've had enormous numbers of people being killed for going against religious authorities for thousands of years - the more rational ones were the ones who were taken out.
They both measure each other to be slower. This is an empirical fact. See above. I'm not playing any games. I'm sticking to what is measured. i.e. doing physics.
You're doing religion - not physics. If you were doing physics you would recognise that the only reliable measurement you make in all this is the one that shows unambiguously that your clock ticked more slowly on average than the stay-at-home clock, but you assert the superiority of the other measurements which conflict with that.
You're playing an irrational game where you change the speed of light relative to the system in order to pretend that experiments 1 and 3 are the same, but they aren't the same.
When you refer to "the system" which observer are you referring to?
I'm referring to the arena in which one of the clocks is at rest throughout all the action.
The speed of light is c as measured by all observers. In all 3 experiments clocks 1 and 2 move at the same speed relative to each other in the first leg and then clock 2 changes reference frames. In all 3 experiments clocks 3 and 4 move at the same speed relative to each other throughout. Throughout it all, all clocks measure the speed of light relative to themselves as c. These are simply the facts.
The fact is that if the speed of light is c in all directions relative to one clock, it cannot be c relative to any clock that is moving relative to that first clock, but you deny this basic fact, and as soon as you do that, you abandon physics in favour of magic.
I don't see the point in adding all these extra people. They're covered by various already existing clocks in the existing 3 experiments. So we've added nothing new. Therefore I see no possibility of any new insights from this. But let's go on and see.
The point is exactly as I stated earlier. If my clock is ticking faster than Lorentz's during the first leg of his trip, your clock is ticking faster than Einstein's on the fist leg of your trip. Alternatively, If your clock is ticking more slowly than Einstein's on the first leg of your trip, then my clock is ticking more slowly than Lorentz's on the first leg of his trip. Either way, its asymmetrical. You are incapable of accepting these mathematical necessities, and that's why you're doing religion rather than physics.
There are five rational possibilities for this when we're testing set 2 and 3 models, as I set out earlier. Those options are:-

(A) My clock ticked more quickly than Lorentz's clock on both legs of his trip.
(B) My clock ticked more quickly than Lorentz's on the first leg and his ticked at the same rate as mine on the second leg.
(C) My clock ticked at the same rate as Lorentz's on the first leg and more quickly than his on the second leg.
(D) My clock ticked more quickly than Lorentz's on the first leg and more slowly than his on the second leg.
(E) My clock ticked more slowly than Lorentz's on the first leg and more quickly than his on the second leg.
None of the above options are valid because none of them refer to what is measured by observers travelling with each clock.
You are simply rejecting logical reasoning (which is part of mathematics). In doing so, you are showing yourself to be plain irrational, just as religious people do when they reject reasoning. All the above options are valid possibilities and they all come from the only reliable measurement made, which is the one that showed a clock has undeniably run slow. You want to reject that measurement in favour of the inferior measurements of apparent relative ticking speeds which we know conflict with the underlying reality.
Ditto.
Again, just flat rejection of reason. That's what it all comes down to - you aren't rational. You're part of an establishment which is really just a church posing as a branch of science.
Einstein's and Lorentz's clocks were ticking at the same rate as each other during the first leg, and my clock and yours were ticking at the same rate as each other during the first leg too. Logic dictates the following asymmetric things:-

If (A) --> not (F), not (G), not (H), not (I).
Therefore if (A) --> (J).

If (B) --> not (F), not (G), not (H), not (I).
Therefore if (B) --> (J).

If (C) --> not (F), not (G), not (I), not (J).
Therefore if (C) --> (H).

if (D) --> not (F), not (G), not (H), not (I).
Therefore if (D) --> (J).

If (E) --> not (H), not (J).
Therefore if (E) --> (F) or (G) or (I).
All irrelevant because all options are invalid. See above.
None of it's irrelevant. All of it's correct (and any competent mathematician will tell you so), but you simply don't respect reason at all. Like religious people, you claim to be rational while making a mockery of reason and mathematics.
As I said earlier, I'm not interested in model numbers.
That's because you rely on being slapdash and on incompatible-model mixing in order to hide your errors from yourself. It's clear that you've gone as far as you can with this though - your thinking is firmly locked. You aren't seeking truth here at all - all you're doing is digging in to defend establishment errors. The funny thing is though, many of the people at the top of the establishment actually agree that these contradictions exist in set 2 models and they are happy to accept that they are broken - they stick to defending the static block model instead.

The other thing that clearly invalidates the set 2 models is the unhappening-and-rehappening-of-events issue as you change frame. You trip up on that too. An event happens at point B while you're at point A, but some frames tell you it's happened and other frames tell you it hasn't happened yet. You believe all of them. To hide the idiocy of your position, you complain that frames don't speak so they don't tell anyone anything, but that's all diversion - frame C analysis produces data that claims the event at B has happened, but frame D analysis produces data that claims the event at B has yet to happen. They can't both be right. And I'm standing at point B, fully aware at one moment when the event had yet to happen, you were getting information from frame C telling you that it has happened AND/OR that at another moment after the event had happened, you were getting information from frame D telling you that it hadn't happened yet. Even when you're fed directly with this contradictory information from rival frames, you still can't see any contradictions! Relativity makes monkeys of many people who imagine that they understand it because they've been taught by the baboons with the brightest backsides, trained to reject the much better intuitive understanding of relativity that they had before their education ever began.

David Cooper
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Re: Does Special Relativity contain contradictions?

Post by David Cooper » October 2nd, 2018, 7:17 pm

Steve3007 wrote:
October 2nd, 2018, 12:01 am
The speed of light is observed to be c relative to all observers, as measure by them. This does not lead to contradictions. It leads to the Lorentz transformations which describe the way that length, time and velocity is measured by various observers.
You're simply denying the existence of relative speeds of light to objects as anything other than c - you only accept the speed of light relative to an object when the object's at rest in the frame used for making the measurement. That is a highly selective rejection of physics. Your position is ludicrous.
Yes - it generates contradictions. By reversing the roles between clocks 3 and 4, you end up asserting that clock 3 is ticking faster than clock 4 in one experiment, and that clock 4 is ticking faster than clock 3 in the other...
No. That assertion is not made. See various previous posts. Note the references to measurement in those posts.
That assertion absolutely is made. You want to use one frame for one case and a different frame for the other case even though there are two pairs of co-moving players involved (who are also side by side) whose clocks must be ticking at the same rate as that of their companion. Because you refuse to use a single frame for the analysis, you end up claiming that D>L and E>S even though we know for certain that D=S and L=E. (Ticking rates during the first leg: D = My clock, L = Lorentz's clock, E = Einstein's clock, S = your clock.) Your mathematical skills are absolutely woeful.
When both experiments are done simultaneously, as in the newest version (with Einstein and Lorentz helping out), your lovely trick results in clock 3 ticking faster than clock 4 while clock 4 ticks faster than clock 3, and it results in our clocks and their clocks not ticking at the same rate as each other while they are side by side and co-moving. That's the contradictions that come out of the set 2 model idiocy.
No it doesn't. For details, look up an analysis of the "twin paradox".
I have a better understanding of the twins "paradox" than the people miseducating the public about it. We're dealing here with my "double-twins non-paradox" thought experiment where the contradictions and asymmetries show up clearly, so there's nothing to be gained from anyone referring to your inferior experiment. You change frame to analyse the S and E part of it separately from the D and L part, but D and S are co-moving during the first leg and L and E are co-moving during the first leg too, so your analysis is borked, generating the utterly moronic claim that D>L and E>S during the first leg even though we know that D=S and L=E.
They'll side with me rather than you, because your way generates contradictions.
Obviously I disagree.
Well, they most certainly don't.
Since you're now appealing to the judgement of others (competent mathematicians), which of them have sided with you so far? As a starter, I'll cite Bertrand Russell on my team. I've gathered that he was a pretty competent mathematician. I suspect that you will now commit the "No True Scotsman" fallacy. But let's see.
I was suggesting to you that you consult a mathematician and run this past him/her, then get his/her agreement for you to post his/her name along with an endorsement of D>L and E>S and D=S and L=E. None of them will give you permission to make them look so stupid. Are you claiming that Bertrand Russell endorses D>L and E>S and D=S and L=E?

They don't accelerate, so I don't have to do any such thing. You are all over the place here, trashing the laws both of physics and mathematics.
For the above quote, just to be absolutely clear, I've included the passage of mine to which it was a reply. This is because, as shown later in this post, you seem so confused as to whether or not you agree with me that the assessment as to whether a clock ticks at a constant rate is only meaningful by comparison with another clock. Look at the above comment of mine and your reply to it.
We have two clocks being compared to each other and you object to that on the basis that you can only make such a comparison by comparing a clock to another clock. You seem to have lost the plot entirely.
As I said, the statement "Clock X ticks at a constant rate throughout" is only meaningful if you specify what other clock you're comparing it to. The only way that you can assess the rate at which a clock is ticking is by comparing it to another clock. If you disagree, describe to me a way to measure the tick rate of a clock without referring to another clock.

In what way am I "trashing the laws both of physics and mathematics" by pointing out this obvious fact to you? Are you sure you actually read the passage which you quoted and replied to here?
The bit about you trashing physics and mathematics actually refers to a whole stack of things you'd said in the post in question, but it does include your comment that came immediately before it too. An unaccelerated clock in deep space will tick at a constant rate, and you don't need another clock to tell you that.
That illegal move doesn't become any less illegal by making it over and over again.
Please precisely specify the "illegal move" to which you are referring. Is it illegal to view the experiment with respect to various different reference frames?
The frame switch is an illegal move because it changes the physics. If you're going to analyse something properly, you need to stick to a single frame for the whole analysis instead of changing the rules along the way.
You are cheating by changing the speed of light relative to the clocks, and changing the one which is regarded as moving.
As stated numerous times before I am not changing the speed of light.
You are changing the speed of light relative to the objects in the experiment.
It is the same as measured by all observers.
What those fools measure is irrelevant if they're stupid enough to believe that they're measuring a speed that they didn't bias into their measurements from the start. All they can work out from their experiments is the speed of light - not the speed of light relative to them. If they believe they can, they are utterly incompetent.
We have two clocks ticking at constant rates relative to each other as they move at a constant speed relative to each other.
So you admit that the only way to measure the tick rate of a clock is by comparing it to another clock?
I've told you from the start that we're comparing the ticking rates of two clocks. I don't know why you have such difficulty understanding that.
Are you also "trashing the laws both of physics and mathematics" as you accused me of doing when I said the same thing?
I was objecting to your objection to a whole host of correct things.
Or are you saying here that "we have two clocks ticking at constant rates relative to each other" but we don't need to compare them with each other in order to decide whether we deem them to be ticking at a constant rate?
No - we have two clocks ticking at potentially different constant rates and we can compare them with each other. Each clock imagines itself to be ticking faster than the other when it looks at the data in which it's considered to be at rest while the other clock is considered to be moving, but when the clocks are reunited, part of the truth is revealed, showing that one of the clocks ran slower then the other during at least one leg of its trip.
In the absence of acceleration, you know it's constant,...
You just know it's constant do you?
That is the standard position in physics, so I don't know why you're objecting to it.
So now you're apparently back to saying that you can know a clock is ticking at a constant rate without comparing it to another clock! You're all over the place!
You're the one who's squirming about all over the place - we've been through all this before. If an alien is twiddling a knob that speeds up or slows down the ticking of that unaccelerating clock, the results of experiments consistently show us that the alien always does the same thing to all the other clocks to hide his intervention from us, so we can always treat such a clock as if it is ticking at a constant rate because that alien is pretty determined not to be caught out.
First, when I point out that the constancy of a clock's ticking is only meaningful by measuring it against another clock, you say I'm "trashing the laws both of physics and mathematics". Then you appear to agree with me. Now you're flip-flopping back again. Which is it? In your view, how do you find out if a clock is ticking at a constant rate?
The only flip-flopping going on is in your head with your braincells desperately trying to find you a way out of the hole you've dug yourself into. I've pointed out that you don't need another clock to compare an unaccelerated clock (sitting in deep space) with because its ticking rate will be constant, but I also never relied on that because at all times I've been comparing two clocks against each other. Your inability to see that is quite staggering, but it explains a lot about how it is that you're so susceptible to mind viruses. You can barely reason at all.
...but we happen to have another clock to compare it with at all times which is also ticking at a constant rate, so there's no problem, until you make an illegal move by changing frame.
"Which is also ticking at a constant rate"? As measured by what? The other clock! Don't you see this simple, obvious logic?!?
That's my whole point, darling - we're comparing two clocks with each other. Each is comparing itself with the other.
I disagree that the animations on your web page do this.
It is as good as an identical scenario - the speeds of travel are high, but we never specified them here. One planet is mine, the other planet is Einstein. Lorentz owns the rocket that travels with Einstein's planet for a while and then returns to me, and the other rocket that stays with me for a while before rushes off after Einstein's planet is yours. It is surprising that you don't recognise the equivalence.
viewtopic.php?p=320779#p320779
We have two clocks being compared with each other, so I don't understand how you have such difficulty recognising the clocks there.
OK, so now you're back to agreeing with me when I said that the only way to measure the tick rate of one clock is to compare it with another clock - the thing that you referred to as "trashing the laws both of physics and mathematics"!
You've more than twisted what I said. I've said all the way through that they're being compared with each other. I had many things in mind when I said you were trashing the laws of physics and mathematics, but the trigger there was that you objected to my claims that clocks 3 and 4 are ticking at constant rates throughout - we know that they must be even without comparing them with each other. There is no need to measure them to know that. I made no comment there whatsoever about measuring them. Let me remind you of the quote to help you understand what you've just mangled:-
that when you say such things as "Clock 3 ticks at a constant rate throughout" and "clock 4 ticks at a different constant rate throughout" you have to specify which other clock you're measuring them against and the reference frame against which you're making those measurements.
They don't accelerate, so I don't have to do any such thing. You are all over the place here, trashing the laws both of physics and mathematics.
I don't have to do any such thing there because we know that the clocks are both ticking at constant rates without having to measure them. It so happens that we are measuring them though by comparing them with each other. That doesn't negate the fact that we don't need to measure them against each other to know that they are ticking at constant rates.

The reason you keep going off on these diversions again displays the difficulties you have in reasoning - you can't compartmentalise anything properly, so there's no hope of you doing any rigorous analysis. You are a hopeless case, but then so are most people out there. The world is in a mess precisely because most people are so hopeless at reasoning.

Steve3007
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Location: UK

Re: Does Special Relativity contain contradictions?

Post by Steve3007 » October 3rd, 2018, 2:42 am

Hi again David.

One of the things I've noticed about your long posts (such as your most recent two) which quote individual parts from my posts and then (ostensibly) reply to those parts is that they don't focus on those parts to which they are ostensibly replying. Hence, the apparent strangeness of your "trashing the laws both of physics and mathematics" criticism which appeared to me to be a reply to an obvious truth uttered by me. For my part, when I break your posts down into individual parts and quote those parts, my reply beneath the quote is to that quote. It's not a general reply to various unspecified things you've said before, although obviously I'm aware of other things that you've said and bear them in mind. Call me an old fashioned Reductionist if you like!

Obviously another thing that's noticeable is that you spend a huge amount of your time simply telling me what an idiot I am - how I'm parroting dogma, following a cult, terrible at maths and physics, incapable of logical reasoning etc etc.

So to save you having to spend more of your time telling me what an idiot I am (which, me being an idiot, isn't going to get through my thick skull), and how terrible I am at maths, physics and logic, all over again, for now I'll stick to one simple identifiable physical claim that you've made. I'd like us (if you're willing) to try to examine it carefully. Then we might finally be able to get it into my thick head what an idiot I truly am! And therefore, by extension, what idiots almost all of the rest of the philosophy-of-physics-discussing community, with the single exception of yourself, are. Although we may have to apply the principle of relativity to the concept of idiocy (just joking). Anyway, let's see.

It is this:

---
David Cooper wrote:An unaccelerated clock in deep space will tick at a constant rate, and you don't need another clock to tell you that.
---

OK, first of all I'd like you to tell me precisely and unambiguously what you mean by the term "constant rate" here. And I'd like you to tell me how you know that this clock you've mentioned here is ticking at this constant rate - I mean the method by which you arrive at that knowledge.

Here are my thoughts:

I presume that your definition of the term "constant rate", in this context, is something like: "the ticks from the clock each have the same period of time between them and that period of time never varies." Yes?

I suspect you will say that this clock is ticking at a constant rate by definition. i.e. you will claim that it is part of the definitions of the terms in the above-quoted statement. In other words, the above quoted statement will be claimed to be true by definition of the terms in it. Similar to the statement "1 + 1 = 2" (or any other tautology). This must be the claim that you will make, because any appeal to empirical evidence would require you to tell me what you propose to measure. And you're claiming that no measurements are required to validate or invalidate the above-quoted claim. In other words, you're claiming that it is a tautology, like all of the statements in pure mathematics or like such statements as: "All mortals will eventually die."

Agree?

OK. I dispute that it is such a tautology.

Here's my take:

As I've said many times before, time is the thing that is measured by clocks. There is no other way to define time. But what is a clock? It's a device for measuring time isn't it? Ooops! We have a perfectly circular pair of definitions of the terms "time" and "clock". What to do?

The only answer is to define general abstract concepts in terms of individual physical examples (much as we do with the laws of physics). As with the definitions of many things in life, the way to define a clock is to point to lots of clocks and say:

"An 'ideal' clock is that property which all of those things (those 'real' clocks) have in common, and time is that thing which is measured by this idealized clock.".

Plato might call it "the form of the clock" (but let's not go there for now).

So what do all clocks have in common? What is this property that we might call clocky-ness? They keep doing the same action over and over again. In other words, they tick. But the only way that we can decide whether each of those ticks is coming at us with the same period of time between each one is to compare them to the ticks of another clock. You may recall that I've explained this to you before by referring to the clock on my wall:
Steve3007 wrote:What do you mean by "ticked at a constant rate"? Relative to what? The only way I can assess whether any clock is ticking at a constant rate is by comparing that clock's ticks with those of another clock which I deem to be ticking at a constant rate. As I sit here and look up at the clock on my wall, I deem the second hand of that clock to be ticking at a constant rate. How? By comparing it to my own internal sense of time - my biological clock. Or by comparing it to some other clock. How else would I make that judgement?
viewtopic.php?p=320538#p320538
(You did reply at the time, but your reply appeared to misunderstand what I was saying here, and I let it drop.)

We cannot even know what the term "constant rate" means, except by reference to other clocks. If we try to think that we do, we just end up with circular definitions that never leave the realm of the abstract:

Constant rate = the ticks from the clock each have the same period of time between them and that period of time never varies.

How do we know that the period of time between each pair of ticks is the same?

We can measure it.

What with?

A clock, of course.

What clock shall we use?

A clock whose ticks come at a constant rate.

---

David, to avoid circular definitions that are doomed to remain forever in the realm of the entirely abstract we have to accept that all of our abstract concepts, including the concept of an ideal clock that ticks at a constant rate, are only rendered physically meaningful when seen as general inductively arrived-at abstractions from specific observed examples. That's science. That's how the laws of physics are arrived at. That is how the concept of a clock is defined in physics. If there were only one clock in the entire universe and all other clocks were absent (including my own biologically-programmed 'clock') then it would be meaningless to call it a clock. There would be no concept whatsoever of its ticks coming at regular time intervals. There would be no way to know whether they were.



Please carefully read the above and think about it for a bit.

Thank you.

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Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 3rd, 2018, 4:02 am

Steve3007 wrote:
October 2nd, 2018, 9:13 am
I also found this article about gravitational time dilation and the equivalence principle:

https://thecuriousastronomer.wordpress. ... elativity/

It seems to show that time dilation occurs between the top and bottom ends of an accelerating rocket. Intriguing.
To apply the equivalence principle, isn't this the same as the situation where the rocket is standing on the ground and a clock at the bottom runs slower than the clock at a top because of the difference in gravity?

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Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 3rd, 2018, 4:38 am

Halc wrote:
October 2nd, 2018, 5:11 pm
Tamminen wrote:
October 2nd, 2018, 5:02 pm

To clarify this: simultaneity is not a symmetric relation in the logical sense of aRb, because if a is simultaneous with b, b is not necessarily simultaneous with a.
Yes it is.
If Bob and John are brothers, the relation of brotherhood is symmetric between them. This means that Bob is John's brother and John is Bob's brother for both Bob's and John's point of view. It is not enough to say that the symmetry is true only for Bob for instance, because in that case John could be pure imagination. We are speaking of real persons.

The same with the reference frames. The reading of 10 in frame D is a real event. The reading of 5 in T is a real event. There is some relation between those events depending on the coordinates available. Now for an observer in D his coordinates compel the him to compute a relation of simultaneity between the events, and the coordinates available for the observer in T to compute a relation of simultaneity with another event in frame D, but for him there is no relation of simultaneity with the reading of 10 in frame D.

If this is not what happens, could you explain why not?

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Re: Does Special Relativity contain contradictions?

Post by Halc » October 3rd, 2018, 6:40 am

Tamminen wrote:
October 3rd, 2018, 4:02 am
To apply the equivalence principle, isn't this the same as the situation where the rocket is standing on the ground and a clock at the bottom runs slower than the clock at a top because of the difference in gravity?
The rocket on the planet is in a non-uniform field, so the bottom is deeper in the well than the top, so is dilated more, yes.
I don't see the equivalence between that and a rocket accelerating out in nowhere. Is the nose not accelerating as much as the tail? The thing keeps a fixed length in its own accelerating reference frame. In any inertial frame, the length is contracting or expanding as it accelerates, so there is a tiny variation on that front, but the difference could be either way depending on if the acceleration is in the same direction as its velocity. Alice and Bob experience the exact same acceleration (G-force), which is not true of the rocket sitting on the ground.

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Re: Does Special Relativity contain contradictions?

Post by Steve3007 » October 3rd, 2018, 6:45 am

(Interesting discussions about General Relativity here, which I intend to comment on later. But, for now, I've just left it at my usual morning reply to David.)

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Re: Does Special Relativity contain contradictions?

Post by Halc » October 3rd, 2018, 7:09 am

Tamminen wrote:
October 3rd, 2018, 4:38 am
This means that Bob is John's brother and John is Bob's brother for both Bob's and John's point of view.
Ah, you've introduced 'from the POV of each brother', but you didn't say that above. The wording was just A simultaneous with B, the B simultaneous with A. In any frame, that is true, but it isn't true if you change frames between the two halves.

If A is simultaneous with B in one frame, A is not necessarily simultaneous with B in another frame, but that doesn't make it asymmetrical. In our example, each brother would, at the 5 year mark from the frame in which he was stationary, say that his other brother's clock simultaneously reads 2.5 years. That sounds pretty symmetrical to me. Either brother can at that point execute the identical U maneuver and catch up to his other brother who will be found to be older.
The same with the reference frames. The reading of 10 in frame D is a real event. The reading of 5 in T is a real event. There is some relation between those events depending on the coordinates available.
Yes, depending on the coordinates. Change the coordinates and the relationship changes. I can make either one before or after the other, or simultaneous, each with a number of different frames.
Now for an observer in D his coordinates compel the him to compute a relation of simultaneity between the events, and the coordinates available for the observer in T to compute a relation of simultaneity with another event in frame D, but for him there is no relation of simultaneity with the reading of 10 in frame D.

If this is not what happens, could you explain why not?
That's what happens, but the asymmetry you seem to be pointing out is due to the fact that you've chosen different numbers to be on each brother's clock. So if you choose 5 in T's clock, and 20 in D's clock, those two events would be unambiguously ordered in any frame. That doesn't make it asymmetrical, it just means you chose events with asymmetric numbers to be on their clocks. So pick events where both their clocks read the same value like I did above with 5 and 5, and the symmetry falls into place.

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Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 3rd, 2018, 7:44 am

Halc:

As I said, I have used the term 'symmetric' as it is used in logic describing one specific type of relation. I fully agree with you that in the physical meaning of the term the situation is symmetrical, and has to be symmetrical because all laws of physics are the same in all frames.

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Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 3rd, 2018, 9:36 am

Halc wrote:
October 3rd, 2018, 6:40 am
Tamminen wrote:
October 3rd, 2018, 4:02 am
To apply the equivalence principle, isn't this the same as the situation where the rocket is standing on the ground and a clock at the bottom runs slower than the clock at a top because of the difference in gravity?
The rocket on the planet is in a non-uniform field, so the bottom is deeper in the well than the top, so is dilated more, yes.
I don't see the equivalence between that and a rocket accelerating out in nowhere. Is the nose not accelerating as much as the tail? The thing keeps a fixed length in its own accelerating reference frame. In any inertial frame, the length is contracting or expanding as it accelerates, so there is a tiny variation on that front, but the difference could be either way depending on if the acceleration is in the same direction as its velocity. Alice and Bob experience the exact same acceleration (G-force), which is not true of the rocket sitting on the ground.
So what is the difference between an accelerating rocket and a rocket in free fall towards a gravitational center? Am I right when I say that according to the equivalence principle there is no difference? However, in the latter case the top is lower in the gravity well all the time.

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Re: Does Special Relativity contain contradictions?

Post by Halc » October 3rd, 2018, 10:39 am

Tamminen wrote:
October 3rd, 2018, 9:36 am
So what is the difference between an accelerating rocket and a rocket in free fall towards a gravitational center? Am I right when I say that according to the equivalence principle there is no difference? However, in the latter case the top is lower in the gravity well all the time.
Steve and I are debating that very thing, and I don't have confidence in my position, but the sites being referenced definitely have mistakes, so that doesn't help.

Yes, the rocket sitting there is effectively a tall building, and there is more dilation at the lower floors due to the deeper gravity well. If the planet spins, the upper floor dilates more due to greater linear motion. On Earth, the gravity effect wins, but build a building tall enough and eventually the two will cancel out. Beyond that, the higher clocks dilate more again.

A rocket falling to Earth will have the lower end dilated being more in the gravity well again. If it is in orbit, I'm not sure if there would be a difference. The rocket (effectively a long stick) tends to align itself vertically due to tidal forces. The lower part has a bit more gravity and the upper part moves a bit faster and accelerates a bit harder due to the additional force from the tension on the stick.

Does acceleration itself contribute to dilation? That's the point we've been discussing. I thought it didn't but I might be wrong.

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Re: Does Special Relativity contain contradictions?

Post by Tamminen » October 3rd, 2018, 10:58 am

Halc wrote:
October 3rd, 2018, 10:39 am
Tamminen wrote:
October 3rd, 2018, 9:36 am
So what is the difference between an accelerating rocket and a rocket in free fall towards a gravitational center? Am I right when I say that according to the equivalence principle there is no difference? However, in the latter case the top is lower in the gravity well all the time.
Steve and I are debating that very thing, and I don't have confidence in my position, but the sites being referenced definitely have mistakes, so that doesn't help.

Yes, the rocket sitting there is effectively a tall building, and there is more dilation at the lower floors due to the deeper gravity well. If the planet spins, the upper floor dilates more due to greater linear motion. On Earth, the gravity effect wins, but build a building tall enough and eventually the two will cancel out. Beyond that, the higher clocks dilate more again.

A rocket falling to Earth will have the lower end dilated being more in the gravity well again. If it is in orbit, I'm not sure if there would be a difference. The rocket (effectively a long stick) tends to align itself vertically due to tidal forces. The lower part has a bit more gravity and the upper part moves a bit faster and accelerates a bit harder due to the additional force from the tension on the stick.

Does acceleration itself contribute to dilation? That's the point we've been discussing. I thought it didn't but I might be wrong.
I have thought about it this way: acceleration makes the flat spacetime curved in the same way as gravity does. Because of this the rocket is like a car that runs downhill with its front always lower than its back. But I don't know.

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