SR Issue

Because you have avoided answering the questions I have put to you.
That reveals quite a lot regarding your agenda.

I have long wondered why the creationists bother with esoteric topics like SR. But the scabs fell from my eyes when reading a book on evolution recently where the author mentions that they do this to discredit radioisotope dating. (I'm guessing that chinglu is a closeted young-earther.)
 
Be clear. What is "completely false" and where is the evidence and line of reasoning that shows it to be false? Here are some possibilities for what you mean by "this" (unclear antecedent):
  1. Did you mean (in the [POST=3198449]OP[/POST] when you wrote "when M and C' are co-located, one lightning strike is located at 2 different positions along the positive x-axis in both coordinate systems, which of course is inconsistent with nature") that somewhere you explained how $$x_Q \neq x_R$$ was "inconsistent with nature" when it has been show that the two different locations also corresponded to two different times, $$ t_Q \neq t_R$$, because you were using two different definitions of "when", $$t=t_P$$ and $$t'=t'_P$$ and since motion is not inconsistent with nature there can be nothing a priori wrong with calculating two different positions? Because I really think you have not shown how this is inconsistent with nature. Indeed, in [post=3199677]post #30[/post], you agreed with me and said "I never claimed there was a law of nature that would not place a light flash at two different places at two different times." And even in the [POST=3198449]OP[/POST] you explicitly calculate $$t_Q$$ and $$t_R$$ to be different.
  2. Did you mean that $$\color{red} (x_Q - x_O) - c(t_Q - t_O) \neq (x_R - x_O) - c(t_R - t_O)$$? Because if you could show that then I would be completely wrong about "Events Q and R ... happen in different positions and times in every frame ...on a light-like line." Using your own numbers, it appears however that $$(x_Q - x_O) - c(t_Q - t_O) = (x_R - x_O) - c(t_R - t_O)$$.
  3. Did you mean there was a response to my observation that you have confused $$t = t_P = t_Q$$ with $$t' = t'_P = t'_R$$ in the [POST=3198449]OP[/POST] where you used the phrase "when C' and M are co-located" ? With two different definitions of this phrase, $$t = t_P$$ with $$t' = t'_P$$, it's obvious that you should expect two different events, with different times and different locations, Q and R.
  4. Did you mean that special relativity says $$t = t_P$$ has the same meaning as $$t' = t'_P$$ and that I was wrong to criticize your ability to work within the assumptions of special relativity? If so, please demonstrate the logical equivalence of the two statements.
  5. If you have not responded to these, then it must be that you mean that failure to respond does not indicate insincerity. But I argue that it does, because you are responding to my post activity but not the content of the posts. Instead you would rather repeat demands for questions already answered and ignore questions directed at you. That's peculiar behavior for someone who is sincere.
In conclusion, the charge of "This is completely false" is vague and unsupported.
No, it doesn't. The [POST=3198449]OP[/POST] asks "when C' and M are co-located, where is the lightning along the positive x-axis for both frame coordinate systems?"
Working in the domain of SR requires acknowledging that "when" has no absolute meaning. $$t=t_O$$ does not have the same meaning as $$t' = t'_O$$. Likewise $$x = x_O$$ does not have the same meaning as $$x' = x'_O$$, so locations have no absolute meaning. And yet $$(x - x_O) = c (t - t_O)$$ does have the same meaning as $$(x' - x'_O) = c (t' - t'_O)$$. When you asked your question in the [POST=3198449]OP[/POST], you used two definitions : "when C' and M are co-located ... for both frame coordinate systems" thus guaranteeing you would get two answers in space-time, not one. To complain that you get two answers and blame SR and not your question is a misrepresentation. SR is self-consistent -- it is not consistent with the question as you wrote it giving one answer.

It's obvious that [post=3198606]post #2[/post] covers all of this. If you didn't understand post #2, you should have asked more questions.

Someone with a cursory knowledge of the physical world and special relativity knows that a space-time event is of zero duration, "speed of light" is a term of art in special relativity, light in vacuum travels at the "speed of light" (and very close to this speed in air), lightning is an electrical discharge of finite (but short by human standards) duration which causes intense heating of the air through which it travels, resulting in light and sound, and (finally) electrical discharges move slower than light (typically, much slower than light in air). In English usage the atmospheric electrical discharges and the accompanying flashes of light are both referred to a "lightning" which is a mass noun. So to count (or refer to single events of) electrical discharges one has to refer to "lightning strikes" (or strokes) and to count emissions of light, one has to refer to "lightning flashes." So according to the [POST=3198449]OP[/POST] what happens at event O is "lightning strikes their [common] location" which refers to a single electrical discharge of idealized zero duration. What propagates at the speed of light through events Q and then R is not electricity but a portion of flash of light. Since you aren't referring to the entirety of the light emitted by the lightning strike, but only the portion that propagates parallel to the +X axis, we are talking about a single light-speed, particle-like, propagating phenomenon so "light" or "flash of light" seems preferable to "flash of lightning" but all are preferred to the construction you used was just "lightning".

With "lightning" being a mass noun, there is literally no problem with it being in multiple locations at the same time -- this distracts from the question you were trying to explore.

In detail he wrote:
or with our current notation:
Since he had just finished giving the coordinate transformation, he is talking about a single event in space-time, O, with coordinates $$\left( x=0, \; y=0, \; z=0, \; t = 0, \;x'=0, \; y'=0, \; z'=0, \; t' = 0 \right)$$ -- He didn't assume $$t = 0$$ and $$t' = 0$$ had the same meaning universally. He didn't assume that "when the origin of the co-ordinates is common to the two systems" had a meaning other than at the place and time that those origins met. He limited his discussion to the portion of space time for which both were true because he was trying to talk about an event in the geometry of space-time before 1908 when Minkowski unified relativity and geometry.

This blurring of "when" [at what time] as used in a discussion of space-time and "when" [under what circumstances] as used to introduce assumptions in logic conflates two different senses of the same word and is a fallacious argument.
http://www.oxforddictionaries.com/us/definition/english/when
http://en.wikipedia.org/wiki/Equivocation 一詞多義

This does not allow you to change the question asked in the OP.

You can't use "if" here -- Because the assumption that C' is not at rest relative to M, any such co-location happens only at discrete event P, not as some universal truth suitable for predicate logic. What you want is first-order logic where the universe of discussion is limited to space-time events and coordinates given to space-time events. [post=3198606]Post #2[/post] is simple to read in the context of first-order logic.

A second reason you can't use "if" here is because if "if" is read to mean "under such circumstances that at some event in space-time C' and M happen to be co-located" then the location of the flash of light doesn't have two answers -- it has the answer "every location on the + X axis" because the answer is not the x or x' value of an event, but the x-coordinate value of a half-line, ℓ, that starts at the event O. But because you don't understand what a logical predicate is, I include this only for completeness, not for your personal edification.
You are missing a comma, because I will not answer a "where" question with yes or no. If you were to ask "Are you finally going to answer this, yes or no?" I would point out that "this" is a question predicated both on assuming special relativity and assuming universality of the truth of simultaneity of non-co-located events, so no simple answer suffices. Where a complex answer suffices, I refer you to [post=3198606]post #2[/post], when I answered over two weeks ago.

Your use of "lightning" and "distance" is problematic, because you said the lightning struck the common (well, "command", but everyone assumes you meant "common") location of M' and M. So to the distance to M is logically zero if you are talking about the lightning strike. If you are talking about the lightning flash, the above comments about "when" and relativity of simultaneity apply. Finally, "distance" between events doesn't have any universal meaning. You could talk about the space-time interval if you wanted something with universal meaning.
You are still talking about three events, P, Q and R. Until you start over and actually label the things you are talking about you will make no progress towards asking questions that make sense. You continue to suffer the delusion that you have a right to demand answers when you pretty much make a hash out of your own discussion and contribute nothing positive to the reputation of this forum.

No you can't because the propagating flash of light never passes through event P. At most you can ask where is the propagating flash of light under the circumstances that apply to the propagating flash of light. Event Q is the answer to where the flash of light is under the circumstance that $$t_Q = t_P$$. Event R is the answer to where the flash of light is under the circumstance that $$t'_R = t'_P$$.
Geometrically, the same way to say this is that Q is the intersection of lines j and ℓ; R is the intersection of lines k and ℓ. Everything else is frame-dependent dross without universal meaning.

Again, you have tried to equivocate the meaning of "when" and substitute "if" as if predicate logic could be substituted for first-order logic. What you need to do is stop pretending you understand the subject matter better than textbooks when you can't even follow the geometry when described in [post=3198606]post #2[/post] or drawn for you in [post=3204088]post #192[/post] and [post=3204151]post #199[/post].

I'm sorry, but I have already addressed the issue of "when C' and M are co-located". I pointed out the statement from Einstein, "when the origin of the co-ordinates is common to the two systems". https://www.fourmilab.ch/etexts/einstein/specrel/www/

I explained this was a logical condition just like Einstein's meaning if "C' and M are co-located".

So, you spent all this effort in this post to discredit my use of the phrase "when C' and M are co-located" in order to tie it to ambiguity which you did not prove. Then, you went on with your post above to draw conclusions based on a logical fallacy.

So, let's get this established right now, was Einstein wrong when he wrote, "when the origin of the co-ordinates is common to the two systems"? This is a yes or no question. I would imagine you know if both clocks at the origin both have 0's, the rest of the frame does not from the other observer point of view. So, my nomenclature is consistent with Einstein's.

Once we get past this, then we can further this education.

For example, you claimed the co-location event of C' and M is a relativity of simultaneity event. I corrected this misunderstanding and you are finally no longer making this claim. If you need me to post the history so that all readers can see what you said, I will be glad to do that.

Anyway, we need to get past your false understanding of "when C' and M are co-located" so that we may proceed.

Are you willing to do that?
 
Because you have avoided answering the questions I have put to you.
That reveals quite a lot regarding your agenda.

You have put forth questions that have nothing to do with math. So, I can't function in that area as far as this thread is concerned became this is a math thread.
 
I have long wondered why the creationists bother with esoteric topics like SR. But the scabs fell from my eyes when reading a book on evolution recently where the author mentions that they do this to discredit radioisotope dating. (I'm guessing that chinglu is a closeted young-earther.)

You seem to be a bigot against Muslims. They are creationists.
 
So that we remember the history of this thread, I am going to review some refuted statements made by arfa brane and rpenner.


the preconception that the concept of "when C' and M are co-located" has the same meaning in both frames. This is a false assumption in any purported thought experiment examining special relativity, because it directly contradicts the relativity of simultaneity. By including it in the question you have been intellectually dishonest in your study of special relativity.
http://www.sciforums.com/showthread.php?141840-SR-Issue&p=3200974&viewfull=1#post3200974

Clearly you are not understanding.
Relativity of simultaneity "depends" on two independent observers in relative motion. It does not depend on two events, since one event is sufficient.
http://www.sciforums.com/showthread.php?141840-SR-Issue&p=3201875&viewfull=1#post3201875


I then posted this quote from wiki which proved one event, like the co-location event of C' and M does not invoke the relativity of simultaneity.

In physics, the relativity of simultaneity is the concept that distant simultaneity – whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame.

According to the special theory of relativity, it is impossible to say in an absolute sense that two distinct events occur at the same time if those events are separated in space.
http://en.wikipedia.org/wiki/Relativity_of_simultaneity

Note above that one event and two observers does not invoke the relativity of simultaneity. It takes two relative motion observers and at least 2 events separated by space. If C' and M are co-located, they are not separated by space as required by the relativity of simultaneity.
 
You have put forth questions that have nothing to do with math. So, I can't function in that area as far as this thread is concerned became this is a math thread.

It's a maths question concerning SR.
You have denied SR in the past.
You even deny your misinterpretations of your current problem as put by at least three other members.
You have had threads closed in the past due to your continuing purposefully it seems, misinterpreting and denying SR, despite irrefutable observational evidence everyday that support it.
By not answering my question, you are in effect saying SR is invalid, are you not?
By claiming your math conglomeration contradicts SR, you are again claiming SR is not valid, are you not?
Others here are claiming [at least three, maybe four] that your maths is wrong, and have shown you where its wrong, but you as you did in past threads, refuse to accept their proof.

Let's make it easy for you...forget FoR's, forget time dilation and length contraction questions, lets forget your religious agenda, but I just want one question answered.
Do you accept SR as valid? yes or no will suffice.
 
It's a maths question concerning SR.
You have denied SR in the past.
You even deny your misinterpretations of your current problem as put by at least three other members.
You have had threads closed in the past due to your continuing purposefully it seems, misinterpreting and denying SR, despite irrefutable observational evidence everyday that support it.
By not answering my question, you are in effect saying SR is invalid, are you not?
By claiming your math conglomeration contradicts SR, you are again claiming SR is not valid, are you not?
Others here are claiming [at least three, maybe four] that your maths is wrong, and have shown you where its wrong, but you as you did in past threads, refuse to accept their proof.

Let's make it easy for you...forget FoR's, forget time dilation and length contraction questions, lets forget your religious agenda, but I just want one question answered.
Do you accept SR as valid? yes or no will suffice.

I would consider your post if it contained math concerning the OP.

But, it does not.
 
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Originally Posted by rpenner View Post
you used two definitions : "when C' and M are co-located ... for both frame coordinate systems" thus guaranteeing you would get two answers in space-time, not one. To complain that you get two answers and blame SR and not your question is a misrepresentation. SR is self-consistent -- it is not consistent with the question as you wrote it giving one answer.

It's obvious that post #2 covers all of this. If you didn't understand post #2, you should have asked more questions.
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""



You have four reasoanbly intelligent mathematicians that have invalidated your claim chinglu.
I have asked a few questions to gauge your knowledge and attitude to SR and if you have an agenda or not.
You have not answered any of them and insist you do not understand what I'm asking.

So, logically, if you do not understand questions like, do you accept time dilation and length contraction with regards to FoR's, how in the world can you claim invincibility in your maths?
 
I would consider your post if it contained math concerning the OP.

But, it does not.

So you see SR as invalid?
Only one question now chinglu, whittled down from the few I did ask you.
Please try and humor me by answering it.
 
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chinglu's approach is well-established (or it should be by now). Start by posting a question about SR which is vaguely worded. If anyone points out that it doesn't correspond to a situation in real life, insist it's "what Einstein said".

Continue to ignore responses, and continue to insist there's a problem with Einstein's theory.
But we can see what the problem really is. chinglu has variously claimed that each observer sees a lightning strike appear in two places, or that each observer can see what the other sees. This is not what SR "claims" at all, and rpenner has pointed this out several times. chinglu just doesn't get it, or he doesn't want to.

But this:
chinglu said:
However, if C' and M are co-located, the OP provides the location of the lightning along the positive x-axis in primed frame coordinates. Since this location is based on the light postulate, then it cannot be questions. RPenner has agreed on this location.

Therefore, if C' and M are co-located there cannot be any disagreement on where the lightning is located in the primed frame along the positive x-axis.

However, the unprimed frame claims if C' and M are co-located, the lightning is located somewhere else in primed frame coordinates along the positive x-axis. This disagreement is not allowed because it contradicts the primed frame light postulate. RPenner has not directly addressed this.
suggests that chinglu does believe that "someone" can see what both observers see, or that each observer can see what the other sees (here, I'm using "see" because we've been talking about lightning, but strictly this should be "observe").

So, with the entirely wrong idea about what simultaneity is, and an inability to even describe it, what's left? Well, I suppose a few people got to talk about what the theory really is.
 
chinglu's approach is well-established (or it should be by now). Start by posting a question about SR which is vaguely worded. If anyone points out that it doesn't correspond to a situation in real life, insist it's "what Einstein said".

Continue to ignore responses, and continue to insist there's a problem with Einstein's theory.
But we can see what the problem really is. chinglu has variously claimed that each observer sees a lightning strike appear in two places, or that each observer can see what the other sees. This is not what SR "claims" at all, and rpenner has pointed this out several times. chinglu just doesn't get it, or he doesn't want to.

But this: suggests that chinglu does believe that "someone" can see what both observers see, or that each observer can see what the other sees (here, I'm using "see" because we've been talking about lightning, but strictly this should be "observe").

So, with the entirely wrong idea about what simultaneity is, and an inability to even describe it, what's left? Well, I suppose a few people got to talk about what the theory really is.

He 'clearly' doesn't want to absorb any knowledge which will make his juvenile analysis wrong. Be careful. I got banned for capitalizing the c and g in chinglu. After he refers to rpenner as RPenner and brucep as BruceP. Numerous times. The fact he is allowed to spew this nonsense over 300 thread posts in the physics and science is pathetic. As you point out a few people got to discuss stuff that was resolved in physics a century ago. rpenner has the ability to do this in a most informative way. Subsequently he's ignored accordingly by the cranks asking the questions.
 
Sure, we can both agree on the disagreement.

However, if C' and M are co-located, the OP provides the location of the lightning along the positive x-axis in primed frame coordinates. Since this location is based on the light postulate, then it cannot be questions.
Yes it can, otherwise you're dealing with absolute time and absolute space, not relativity.

Therefore, if C' and M are co-located there cannot be any disagreement on where the lightning is located in the primed frame along the positive x-axis.
Yes there can, bceause they both think the other observers rulers are short and their clocks are slow.

However, the unprimed frame claims if C' and M are co-located, the lightning is located somewhere else in primed frame coordinates along the positive x-axis. This disagreement is not allowed because it contradicts the primed frame light postulate. RPenner has not directly addressed this.
Why are you treating the primed frame as being a prefered frame? Relativity has no preferred frame because preferred frames require absolute time and space.

From where I sit, your assertions have been thoroughly refuted by Neddy, Rpenner and Arfa, and you're standing on very thin ice.
 
Yes it can, otherwise you're dealing with absolute time and absolute space, not relativity.


Yes there can, bceause they both think the other observers rulers are short and their clocks are slow.


Why are you treating the primed frame as being a prefered frame? Relativity has no preferred frame because preferred frames require absolute time and space.

From where I sit, your assertions have been thoroughly refuted by Neddy, Rpenner and Arfa, and you're standing on very thin ice.



And me...don't forget me! :) I know I'm only a minion at this game, but I did pick up with the non absolute nature of space and time early in the event, and chinglu's usual refusal to recognise it.
 
A question I had about the business of multiplying time by the speed of light, or "setting c to 1", I think I now understand a bit better.

Minkowski space has a rest frame where the vertical axis is perpendicular to the horizontal one; Penrose states that t = time only in a frame of rest where time is 'perpendicular' to space in both the Minkowski-orthogonal sense, and geometrically.

But we want time and space to have the same units. Make c = 1; 1 what? Well, suppose you call it a unit of "light velocity", and so ct has units of metres, an x axis has the same units, so you can consider squares of spacetime. Alternatively, as Penrose does, divide the spatial coordinates by c and have units of time on both axes. Otherwise if c = 1 then you will still have units of time and units of distance; more importantly, v = c will have a slope of 1.
 
It's a maths question concerning SR.
You have denied SR in the past.
You even deny your misinterpretations of your current problem as put by at least three other members.
You have had threads closed in the past due to your continuing purposefully it seems, misinterpreting and denying SR, despite irrefutable observational evidence everyday that support it.
By not answering my question, you are in effect saying SR is invalid, are you not?
By claiming your math conglomeration contradicts SR, you are again claiming SR is not valid, are you not?
Others here are claiming [at least three, maybe four] that your maths is wrong, and have shown you where its wrong, but you as you did in past threads, refuse to accept their proof.

Let's make it easy for you...forget FoR's, forget time dilation and length contraction questions, lets forget your religious agenda, but I just want one question answered.
Do you accept SR as valid? yes or no will suffice.

If chinglu had a clue about the math he'd thank rpenner for clearing up his mistakes. It sounds like he's trying to assert some authority based on his math prowess. IE like you shouldn't participate because you're not as mathematically lame as he is. You know 'this is a math thread'.

Oh yeah LOL.
 
If chinglu had a clue about the math he'd thank rpenner for clearing up his mistakes. It sounds like he's trying to assert some authority based on his math prowess. IE like you shouldn't participate because you're not as mathematically lame as he is. You know 'this is a math thread'.

Oh yeah LOL.



I asked him a number of questions earlier and he has refused to answer them.
He has backed himself way into a corner with this one methinks!
 
OK, here is the math for each frame if C' and M are co-located. Your diagram follows these calculations.

If C' and M are co-located, SR claims the lightning is located at M' frame space-time coordinates of $$(d'(1-v/c),0,0,d'(1-v/c)/c)$$ and $$(d',0,0,d'/c)$$.

Now, in the primed frame if C' and M are co-located, the lightning is located at $$(d',0,0,d'/c)$$. This is based on the light postulate and this is the only correct answer.

On the other hand, if C' and M are co-located, the unprimed frame places the lightning at $$(d'(1-v/c),0,0,d'(1-v/c)/c)$$ in primed frame coordinates.

This is what your diagram shows. However, if C' and M are co-located, the lightning is at $$(d',0,0,d'/c)$$ period. There is no disagreement allowed or that disagreement refutes the light postulate.


First of all, SR does not claim that $$(x',y',z',t')=(d'(1-v/c),0,0,d'(1-v/c)/c)$$ is the same event as $$(x',y',z',t')=(d',0,0,d'/c)$$.


Second, none of the $$(x',y',z',t')$$ coordinates that you just posted violates the light postulate, because $$x'=ct'$$ holds true for all of them.
 
Yeah, so regardless of whether multiplying time by a fixed velocity, or dividing distances by the same fixed velocity changes the units, in an abstract "velocity space" a line with a slope of 1 can be used to represent this fixed velocity, only if the perpendicular distances along each axis are equal. In other words, squares of spacetime.

But special relativity also relies on a notion of a reliable clock with a worldine along the t axis in a rest frame. It also addresses the problem of synchronous clocks and a process of synchronisation. Simultaneous events are synchronous with clock events, so the clock is supposed to "determine" where an observer's simultaneous frame is; the reliable clock marks out successive simultaneous frames, like parallel planes.
 
But special relativity also relies on a notion of a reliable clock with a worldine along the t axis in a rest frame. It also addresses the problem of synchronous clocks and a process of synchronisation. Simultaneous events are synchronous with clock events, so the clock is supposed to "determine" where an observer's simultaneous frame is; the reliable clock marks out successive simultaneous frames, like parallel planes.

I'm not sure how his denial of the non absolute nature of space and time, fit in with his religious agenda though.
Would be Interesting to find out.
I mean even the Catholic church recognise GR and the BB as descriptions of reality and origins...Except of course, they quickly then invoke their deity to explain that origin.
But how chinglu's creationist agenda fits in with denying the obvious reality of space and time as non absolute, has me well and truly buggered.
 
The unification of space and time is exemplified by the common practice of selecting a metric (the measure that specifies the interval between two events in spacetime) such that all four dimensions are measured in terms of units of distance: representing an event as $$\, (x_0,x_1,x_2,x_3)\, = \,(ct,x,y,z)$$ (in the Lorentz metric) or $$\,(x_1,x_2,x_3,x_4)\, =\, (x,y,z,ict)$$ (in the original Minkowski metric) where c is the speed of light.[11]

The metrical descriptions of Minkowski Space and spacelike, lightlike, and timelike intervals given below follow this convention, as do the conventional formulations of the Lorentz transformation.
--http://en.wikipedia.org/wiki/Spacelike#Spacetime_intervals
So Minkowski originally used imaginary time coordinates. Since i[sup]2[/sup] = -1 that means the metric is not Euclidean (it has a 'negative square' in it), this is not something you can define in the Euclidean plane, where all distances are positive.
 
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