4.1 Changing reference frames and non-simultaneity . . . . . . 2 4.2 Lorentz invariance of the wave equation. . . . . . . . . . . . 3 4.3 Observed simultaneity and Derived simultaneity. . . . . . . 5 4.4 Everybody sees the same light-cone frame . . . . . . . . . . 6 4.5 Passengers in rows and atoms in rows . . . . . . . . . . . . . 8 4.6 The velocity dependent viewing angle . . . . . . . . . . . . . 9 4.7 Simultaneity and the invariance of size . . . . . . . . . . . . 10 4.8 The relative versus the absolute viewing angle . . . . . . . 12 4.9 The ellipsoids of simultaneity . . . . . . . . . . . . . . . . . . . 16 4.10 From ellipsoids to spheres of simultaneity . . . . . . . . . . 20 4.11 Step 1: From absolute to relative positions . . . . . . . . . 24 4.12 Step 2: Viewing while Lorentz contracted. . . . . . . . . . 26 4.13 Simultaneity from the Spherical Mirror clock . . . . . . . . 28 4.14 Reversal of Lorentz contraction . . . . . . . . . . . . . . . . 32 4.15 Reversal of Time dilation. . . . . . . . . . . . . . . . . . . . . 34 4.16 Simultaneity from Huygens principle . . . . . . . . . . . . . 38 4.17 Simultaneity and the light wavefront direction . . . . . . 39 4.18 The wavefront rotation of matter waves . . . . . . . . . . 42 4.19 Negative energy waves and wavefront rotation. . . . . . 44
The subject is maybe a bit elementary for a QFT book but a substantial effort is made to visualize why exactly we experience different simultaneities in different reference frames and why we experience our world as invariant under boosts.
It is done so in a pedestrian step by step mode with lots of visualizations. The most pedestrian path would start at 4.3 and end at 4.12
1. The following sentence appears on page 13: "The crossings of the x-axis and x'-axis mark the events from which the light rays reach the observer in the middle at the same time." In the figure, x and x' are not on or parallel to each other.therefore this is a wheelerian thesis rather than an STR one.
2. Given that X is thera horizontal axis of system A (x,y,z) and that cs B (x',y',z') moves along it at v, if X' is NOT on or parallel to X an affine rotation is to be performed - as stipulated by Minkowski in his 1907 paper "Space and Time" - in order to make it so. Once X and X' ARE on or parallel to each other, there is no reason for any "boost" or "rotation" to change the angle as per your wheelerian figure.
3. If we have 3 or more systems each moving at a different speed than the others, WHY does each X' or X" etc axis rotate by exactly the amount needed for your wheelerian "explanation" of the reason that lengths "appear" contracted "even though they aren't")!
Hi Glird, thank you for reading and providing feedback.
> 1. The following sentence appears on page 13: > "The crossings of the x-axis and x'-axis mark the events from which > the light rays reach the observer in the middle at the same time." > In the figure, x and x' are not on or parallel to each > other.therefore this is a wheelerian thesis rather than an STR one.
> 2. Given that X is thera horizontal axis of system A (x,y,z) and that > cs B (x',y',z') moves along it at v, if X' is NOT on or parallel to X > an affine rotation is to be performed - as stipulated by Minkowski in > his 1907 paper "Space and Time" - in order to make it so. Once X and > X' ARE on or parallel to each other, there is no reason for any > "boost" or "rotation" to change the angle as per your wheelerian > figure.
What the figure on page 13 shows is how a "fast jetline passenger" receives light, from the passenger behind him, which has traveled longer as the light from the passenger in front of him.
It's this difference which defines the different simultaneity in the moving reference frame.
> 3. If we have 3 or more systems each moving at a different speed than > the others, WHY does each X' or X" etc axis rotate by exactly the > amount needed for your wheelerian "explanation" of the reason that > lengths "appear" contracted "even though they aren't")!
> glird
Real physical Lorentz contraction is shown by the moving stable solutions of the wave equations for the EM potentatial field and the matter fields (basically the Klein Gordon equation) The potential field of a moving charge is Lorentz contracted.
The physically Lorentz contracted moving train is LONGER by a factor gamma on the x'-axis compared to the length of the train at rest (measured on the x'-axis).
Hans de Vries wrote: > Real physical Lorentz contraction is shown by the moving stable > solutions of the wave equations for the EM potentatial field and > the matter fields (basically the Klein Gordon equation)
If by "physical" you mean "what I measure", then this is correct. But that is often NOT what people expect "physical" to mean. In particular, for the case of a moving rod, most people expect "physical length contraction" to mean "the rod itself gets shorter", and this most definitely is NOT true. Experts will move on without being confused by your phrasing, but non-experts usually do get confused by such statements -- it happens all the time around here.
For a thing like a rod it is QUITE CLEAR that looking at it from a moving frame does not affect the thing itself, so the object itself is not physically affected by any observer's "length contraction". For fields, which are not things (in the same sense that a rod is a thing, anyway), it's clear that the field (qua function on the manifold) is not affected by any coordinates whatsoever, "moving" or otherwise.
So I advise authors to avoid the term "physical" when discussing "length contraction" or "time dilation", because it provides no added value, and can easily cause confusion. Especially among people not already expert in relativity (which is nearly everyone around here). Say "measured" instead, because that is really what you mean.
Everything I said about "physical" also applies to "real" -- non-experts have an even stronger expectation that a "real length contraction" of a rod applies to the rod itself. Again, say "measured" instead, because that's what you mean.
The underlying problem is that words like "physical" and "real" do not have a single, well-defined meaning. Different people read different connotations into them. While this can never be completely eliminated, these particular words are especially prone to such misinterpretation, and the results can be extremely confusing to non-experts.
> Hans de Vries wrote: >> Real physical Lorentz contraction is shown by the moving stable >> solutions of the wave equations for the EM potentatial field and >> the matter fields (basically the Klein Gordon equation)
> If by "physical" you mean "what I measure", then this is correct. But that > is often NOT what people expect "physical" to mean. In particular, for the > case of a moving rod, most people expect "physical length contraction" to > mean "the rod itself gets shorter", and this most definitely is NOT true. > Experts will move on without being confused by your phrasing, but > non-experts usually do get confused by such statements -- it happens all > the time around here.
> For a thing like a rod it is QUITE CLEAR that looking at it from a moving > frame does not affect the thing itself, so the object itself is not > physically affected by any observer's "length contraction". For fields, > which are not things (in the same sense that a rod is a thing, anyway), > it's clear that the field (qua function on the manifold) is not affected > by any coordinates whatsoever, "moving" or otherwise.
> So I advise authors to avoid the term "physical" when discussing "length > contraction" or "time dilation", because it provides no added value, and > can easily cause confusion. Especially among people not already expert in > relativity (which is nearly everyone around here). Say "measured" instead, > because that is really what you mean.
> Everything I said about "physical" also applies to "real" -- non-experts > have an even stronger expectation that a "real length contraction" of a > rod applies to the rod itself. Again, say "measured" instead, because > that's what you mean.
> The underlying problem is that words like "physical" and "real" do not > have a single, well-defined meaning. Different people read different > connotations into them. While this can never be completely eliminated, > these particular words are especially prone to such misinterpretation, and > the results can be extremely confusing to non-experts.
Nicely put .. a sizable proportion of arguments here could be averted by taking that advice. Words like "physical" and "real" provides the ambiguity crackpots need in their desperate attempts to construct some sort of strawman argument.
On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote:
> Hans de Vries wrote: > > Real physical Lorentz contraction is shown by the moving stable > > solutions of the wave equations for the EM potentatial field and > > the matter fields (basically the Klein Gordon equation)
> The underlying problem is that words like "physical" and "real" do not > have a single, well-defined meaning. Different people read different > connotations into them. While this can never be completely eliminated, > these particular words are especially prone to such misinterpretation, > and the results can be extremely confusing to non-experts.
> Tom Roberts
Hi Tom,
I certainly do agree that words like "physical" and "real" do not have a single, well-defined meaning, and can cause additional confusion to already confused people. I also appreciate that you want to reserve the word "real" for the proper, invariant, character- ristics. I'll be more careful.
The use of the word physical however should to be seen in the context of the book itself as a quantum field theory book. All objects/observers are described as propagating according to the relativistic wave equations.
The (linear) relativistic wave equations can be represented as the continuum limit of simple discrete mass/spring systems. See for example section 3.4 which contains an introductory discussion of the Klein Gordon equation in the context of Time dilation: http://physics-quest.org/Book_Chapter_Time_Dilation.pdf
The moving stable solutions of these systems exhibit both Lorentz contraction and Time dilation (The latter already in the form of the eigen frequency of a particle along its trajectory).
This (all within a single reference frame) without any knowledge of the Lorentz transform itself and even though a mass/spring system representation picks out a specific preferred reference frame.
The wave equations, being compatible with special relativity, Give actually rise to Lorentz contraction and Time dilation which Is not that surprisingly and they should be expected to do so.
> On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: >> Hans de Vries wrote: >> > Real physical Lorentz contraction is shown by the moving stable >> > solutions of the wave equations for the EM potentatial field and >> > the matter fields (basically the Klein Gordon equation)
>> The underlying problem is that words like "physical" and "real" do not >> have a single, well-defined meaning. Different people read different >> connotations into them. While this can never be completely eliminated, >> these particular words are especially prone to such misinterpretation, >> and the results can be extremely confusing to non-experts.
>> Tom Roberts
> Hi Tom,
> I certainly do agree that words like "physical" and "real" do > not have a single, well-defined meaning, and can cause additional > confusion to already confused people. I also appreciate that you > want to reserve the word "real" for the proper, invariant, character- > ristics. I'll be more careful.
The underlying problem is that words like Lorentz "contraction" and time "dilation" do not have a single, well-defined meaning. Einstein dilates length, Lorentz contracts length. Einstein: xi = x'/sqrt(1-v^2/c^2) where x' = x-vt. Lorentz: L = L0 * sqrt(1-v^2/c^2)
The underlying problem is that some idiots don't know the difference between "multiply" and "divide". Be more careful.
On Nov 8, 1:28 pm, "Androcles" <Headmas...@Hogwarts.physics_p> wrote:
> The underlying problem is that words like Lorentz "contraction" > and time "dilation" do not have a single, well-defined meaning. > Einstein dilates length, Lorentz contracts length. > Einstein: > xi = x'/sqrt(1-v^2/c^2) where x' = x-vt. > Lorentz: > L = L0 * sqrt(1-v^2/c^2)
> The underlying problem is that some idiots don't know the > difference between "multiply" and "divide". > Be more careful.
Hi, Androcles
Both your expressions are equally well valid.
It should be noted that L and L0 do not contain the same set of events so the formula only serves to determine the correct measured length of a static non-changing object.
If the object changes over time then you need the first expression to determine the correct length at a certain time t.
Regards, Hans
The second expression follows from the Lorentz transform: --------------------------------------------------------- starting with....: x = gamma(x' + beta t') inserting........: t' = gamma(t - beta x ) and setting......: t = 0 gives............: x = gamma(x'-beta^2 gamma^2 x) and finally......: x = x'/gamma ---------------------------------------------------------
> The underlying problem is that words like Lorentz "contraction" > and time "dilation" do not have a single, well-defined meaning. > Einstein dilates length, Lorentz contracts length. > Einstein: > xi = x'/sqrt(1-v^2/c^2) where x' = x-vt. > Lorentz: > L = L0 * sqrt(1-v^2/c^2)
> The underlying problem is that some idiots don't know the > difference between "multiply" and "divide". > Be more careful.
Hi, Androcles
Both your expressions are equally well valid.
It should be noted that L and L0 do not contain the same set of events so the formula only serves to determine the correct measured length of a static non-changing object.
If the object changes over time then you need the first expression to determine the correct length at a certain time t.
Regards, Hans
The second expression follows from the Lorentz transform: --------------------------------------------------------- starting with....: x = gamma(x' + beta t') inserting........: t' = gamma(t - beta x ) and setting......: t = 0 gives............: x = gamma(x'-beta^2 gamma^2 x) and finally......: x = x'/gamma --------------------------------------------------------- =============================================
> > Hans de Vries wrote: > >> Real physical Lorentz contraction is shown by the moving stable > >> solutions of the wave equations for the EM potentatial field and > >> the matter fields (basically the Klein Gordon equation)
> > If by "physical" you mean "what I measure", then this is correct. But that > > is often NOT what people expect "physical" to mean. In particular, for the > > case of a moving rod, most people expect "physical length contraction" to > > mean "the rod itself gets shorter", and this most definitely is NOT true. > > Experts will move on without being confused by your phrasing, but > > non-experts usually do get confused by such statements -- it happens all > > the time around here.
> > For a thing like a rod it is QUITE CLEAR that looking at it from a moving > > frame does not affect the thing itself, so the object itself is not > > physically affected by any observer's "length contraction". For fields, > > which are not things (in the same sense that a rod is a thing, anyway), > > it's clear that the field (qua function on the manifold) is not affected > > by any coordinates whatsoever, "moving" or otherwise.
> > So I advise authors to avoid the term "physical" when discussing "length > > contraction" or "time dilation", because it provides no added value, and > > can easily cause confusion. Especially among people not already expert in > > relativity (which is nearly everyone around here). Say "measured" instead, > > because that is really what you mean.
> > Everything I said about "physical" also applies to "real" -- non-experts > > have an even stronger expectation that a "real length contraction" of a > > rod applies to the rod itself. Again, say "measured" instead, because > > that's what you mean.
> > The underlying problem is that words like "physical" and "real" do not > > have a single, well-defined meaning. Different people read different > > connotations into them. While this can never be completely eliminated, > > these particular words are especially prone to such misinterpretation, and > > the results can be extremely confusing to non-experts.
> Nicely put .. a sizable proportion of arguments here could be averted by > taking that advice. Words like "physical" and "real" provides the ambiguity > crackpots need in their desperate attempts to construct some sort of > strawman argument.- Hide quoted text -
> - Show quoted text -
Not only crackpots but anyone trying to get things straight in their own mind. It is easy after we understand things to accept them as being the proper explaination, but when seeing it presented for the first time we are usually a bit sceptical and evaluate each step of the process. In doing so we each form our own opinion of what is "really" going on. If the explaination is solid and guides the learner through every step of reasoning there should be no problem in arriving at the correct conclusion. The problem with some around here is that they took a wrong step early on and convinced themselves that they got it right while everyone else went the wrong way. And every time they travel down that path they wear the rut deeper in the direction of the wrong path.
Anyway :) I agree that should not be used at this point. It might be worth discussing them seperately though.
Hans de Vries wrote: > On Nov 8, 1:28 pm, "Androcles" <Headmas...@Hogwarts.physics_p> wrote:
>> The underlying problem is that words like Lorentz "contraction" >> and time "dilation" do not have a single, well-defined meaning. >> Einstein dilates length, Lorentz contracts length. >> Einstein: >> xi = x'/sqrt(1-v^2/c^2) where x' = x-vt. >> Lorentz: >> L = L0 * sqrt(1-v^2/c^2)
>> The underlying problem is that some idiots don't know the >> difference between "multiply" and "divide". >> Be more careful.
> Hi, Androcles
> Both your expressions are equally well valid.
> It should be noted that L and L0 do not contain the same set of > events so the formula only serves to determine the correct measured > length of a static non-changing object.
> If the object changes over time then you need the first expression > to determine the correct length at a certain time t.
> Regards, Hans
> The second expression follows from the Lorentz transform: > --------------------------------------------------------- > starting with....: x = gamma(x' + beta t') > inserting........: t' = gamma(t - beta x ) > and setting......: t = 0 > gives............: x = gamma(x'-beta^2 gamma^2 x)
> < In particular, for the case of a moving rod, most people expect "physical length contraction" to mean "the rod itself gets shorter", and this most definitely is NOT true. Experts will move on without being confused by your phrasing, but non-experts usually do get confused by such statements -- it happens all the time around here. >
Thus sayeth a self-deluded amateurish expert.
>< For a thing like a rod it is QUITE CLEAR that looking at it from a moving frame does not affect the thing itself, so the object itself is not physically affected by any observer's "length contraction".
For fields, which are not things (in the same sense that a rod is a thing, anyway), it's clear that the field (qua function on the manifold) is not affected by any coordinates whatsoever, "moving" or otherwise.>
Correct.
>< So I advise authors to avoid the term "physical" when discussing "length contraction" or "time dilation", because it provides no added value, and can easily cause confusion. Especially among people not already expert in relativity (which is nearly everyone around here).
Say "measured" instead, because that is really what you mean. >
When "experts" say 'physical" THEY mean "measured". In STR, which uses esynched clocks as measuring tools, the difference in setings per successive clock of a given such esynched system allows the measured 'length contraction" of a given system is a function of that difference; and may not be physically real.
> <Everything I said about "physical" also applies to "real" -- non-experts have an even stronger expectation that a "real length contraction" of a rod applies to the rod itself. >
It DOES. "Experts" think that the contractions "don't really_waderdatmeens happen" but are only a figment "as measured by" differently moving systems.
>< Again, say "measured" instead, because
[if you are an ex pert] that's what you mean. The underlying problem is that words like "physical" and "real" do not have a single, well-defined meaning. Different people read different connotations into them. While this can never be completely eliminated, these particular words are especially prone to such misinterpretation, and the results can be extremely confusing to non- experts [such as}
> Hans de Vries wrote: >> This should be: >> x = gamma(x'-beta^2 gamma x)
Correct, Thanks for correcting the typo. At least somebody who reads this seriously :^)
Regards, Hans ========================================= I asked you a serious question and you can't answer it. What hat did you pull your magic gamma from? Disregards, Androcles.
This is what turns your "multiply by gamma" into a "divide by gamma" ============================================ Perhaps you are too stupid to understand the serious question. Hint: http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img37.gif beta = 1/sqrt( (c+v)(c-v)/c^2) = 1/sqrt( (c^2-v^2)/c^2) = 1/sqrt( c^2/c^2 - v^2/c^2) = 1/sqrt( 1 - v^2/c^2) Explain why any idiot would compute that. What fuckin' hat did you pull your MAGIC gamma from, you IMBECILE?
> This is what turns your "multiply by gamma" into a "divide by gamma" > ============================================ > Perhaps you are too stupid to understand the serious question. > Hint: > http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img37.gif > beta = 1/sqrt( (c+v)(c-v)/c^2) > = 1/sqrt( (c^2-v^2)/c^2) > = 1/sqrt( c^2/c^2 - v^2/c^2) > = 1/sqrt( 1 - v^2/c^2) > Explain why any idiot would compute that. > What fuckin' hat did you pull your MAGIC gamma from, you IMBECILE?
You can move with respect to light. That is the cause of non simultaneity.
Hans, as Dirk warned me a few years back when I ventured into this newsgroup, Androcles is abusive, foul mouthed and not interested in intelligent, civilised discussion.
Hans de Vries wrote: > On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: >> The underlying problem is that words [...]
> I certainly do agree that words like "physical" and "real" do > not have a single, well-defined meaning, and can cause additional > confusion to already confused people. I also appreciate that you > want to reserve the word "real" for the proper, invariant, character- > ristics.
It is not that "I" want to reserve the word "real" for proper, invariant characteristics. The issue is what your readers expect the word to mean, and how THEY will interpret your words. As I said, this varies a lot among different readers, which implies that the usage of such ambiguous words should either be avoided, or explained carefully and completely such that the ambiguity is resolved by the author. As words like "real" and "physical" add little or no value, I find that avoiding them is usually better than explaining them.
Among experts, who are clearly aware of the difficulties of coordinate dependencies in descriptions, "real" generally does apply only to proper, invariant characteristics of objects. Among non-experts this most definitely is not so.
> Hans de Vries wrote: > > On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: > >> The underlying problem is that words [...]
> > I certainly do agree that words like "physical" and "real" do > > not have a single, well-defined meaning, and can cause additional > > confusion to already confused people. I also appreciate that you > > want to reserve the word "real" for the proper, invariant, character- > > ristics.
> It is not that "I" want to reserve the word "real" for proper, invariant > characteristics. The issue is what your readers expect the word to mean, and how > THEY will interpret your words. As I said, this varies a lot among different > readers, which implies that the usage of such ambiguous words should either be > avoided, or explained carefully and completely such that the ambiguity is > resolved by the author. As words like "real" and "physical" add little or no > value, I find that avoiding them is usually better than explaining them.
> Among experts, who are clearly aware of the difficulties of coordinate > dependencies in descriptions, "real" generally does apply only to proper, > invariant characteristics of objects. Among non-experts this most definitely is > not so.
> Tom Roberts
If light moves and matter moves light will take a little more time to reach the matter that has moved. This effects simultaneity and nonsimultaneity principle.
> On Nov 12, 9:34 am, Tom Roberts <tjrob...@sbcglobal.net> wrote: >> Hans de Vries wrote: >> > On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: >> >> The underlying problem is that words [...]
>> > I certainly do agree that words like "physical" and "real" do >> > not have a single, well-defined meaning, and can cause additional >> > confusion to already confused people. I also appreciate that you >> > want to reserve the word "real" for the proper, invariant, character- >> > ristics.
>> It is not that "I" want to reserve the word "real" for proper, invariant >> characteristics. The issue is what your readers expect the word to mean, >> and how >> THEY will interpret your words. As I said, this varies a lot among >> different >> readers, which implies that the usage of such ambiguous words should >> either be >> avoided, or explained carefully and completely such that the ambiguity is >> resolved by the author. As words like "real" and "physical" add little or >> no >> value, I find that avoiding them is usually better than explaining them.
>> Among experts, who are clearly aware of the difficulties of coordinate >> dependencies in descriptions, "real" generally does apply only to proper, >> invariant characteristics of objects. Among non-experts this most >> definitely is >> not so.
>> Tom Roberts
> If light moves
It better well had move :) Which direction is it moving?
> and matter moves
Relative to whom? And in which direction?
> light will take a little more time to > reach the matter that has moved.
More time than what?
> This effects simultaneity and > nonsimultaneity principle.
Don't know if it does, or in what way, as your statement is a bit vague
> > On Nov 12, 9:34 am, Tom Roberts <tjrob...@sbcglobal.net> wrote: > >> Hans de Vries wrote: > >> > On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: > >> >> The underlying problem is that words [...]
> >> > I certainly do agree that words like "physical" and "real" do > >> > not have a single, well-defined meaning, and can cause additional > >> > confusion to already confused people. I also appreciate that you > >> > want to reserve the word "real" for the proper, invariant, character- > >> > ristics.
> >> It is not that "I" want to reserve the word "real" for proper, invariant > >> characteristics. The issue is what your readers expect the word to mean, > >> and how > >> THEY will interpret your words. As I said, this varies a lot among > >> different > >> readers, which implies that the usage of such ambiguous words should > >> either be > >> avoided, or explained carefully and completely such that the ambiguity is > >> resolved by the author. As words like "real" and "physical" add little or > >> no > >> value, I find that avoiding them is usually better than explaining them.
> >> Among experts, who are clearly aware of the difficulties of coordinate > >> dependencies in descriptions, "real" generally does apply only to proper, > >> invariant characteristics of objects. Among non-experts this most > >> definitely is > >> not so.
> >> Tom Roberts
> > If light moves
> It better well had move :) Which direction is it moving?
> > and matter moves
> Relative to whom? And in which direction?
> > light will take a little more time to > > reach the matter that has moved.
> More time than what?
> > This effects simultaneity and > > nonsimultaneity principle.
> Don't know if it does, or in what way, as your statement is a bit vague- Hide quoted text -
> - Show quoted text -
Matter moves in three dimensions with a direction. It can catch up to the movement of light by this. Light then is moving slower to the matter frame.
>> > On Nov 12, 9:34 am, Tom Roberts <tjrob...@sbcglobal.net> wrote: >> >> Hans de Vries wrote: >> >> > On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: >> >> >> The underlying problem is that words [...]
>> >> > I certainly do agree that words like "physical" and "real" do >> >> > not have a single, well-defined meaning, and can cause additional >> >> > confusion to already confused people. I also appreciate that you >> >> > want to reserve the word "real" for the proper, invariant, >> >> > character- >> >> > ristics.
>> >> It is not that "I" want to reserve the word "real" for proper, >> >> invariant >> >> characteristics. The issue is what your readers expect the word to >> >> mean, >> >> and how >> >> THEY will interpret your words. As I said, this varies a lot among >> >> different >> >> readers, which implies that the usage of such ambiguous words should >> >> either be >> >> avoided, or explained carefully and completely such that the ambiguity >> >> is >> >> resolved by the author. As words like "real" and "physical" add little >> >> or >> >> no >> >> value, I find that avoiding them is usually better than explaining >> >> them.
>> >> Among experts, who are clearly aware of the difficulties of coordinate >> >> dependencies in descriptions, "real" generally does apply only to >> >> proper, >> >> invariant characteristics of objects. Among non-experts this most >> >> definitely is >> >> not so.
>> >> Tom Roberts
>> > If light moves
>> It better well had move :) Which direction is it moving?
>> > and matter moves
>> Relative to whom? And in which direction?
>> > light will take a little more time to >> > reach the matter that has moved.
>> More time than what?
>> > This effects simultaneity and >> > nonsimultaneity principle.
>> Don't know if it does, or in what way, as your statement is a bit vague- >> Hide quoted text -
>> - Show quoted text -
> Matter moves in three dimensions with a direction.
Relative to whom?
> It can catch up to > the movement of light by this.
Matter cannot "catch up to" light, because light is faster than matter
> Light then is moving slower to the > matter frame.
> >> > On Nov 12, 9:34 am, Tom Roberts <tjrob...@sbcglobal.net> wrote: > >> >> Hans de Vries wrote: > >> >> > On Nov 7, 11:50 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote: > >> >> >> The underlying problem is that words [...]
> >> >> > I certainly do agree that words like "physical" and "real" do > >> >> > not have a single, well-defined meaning, and can cause additional > >> >> > confusion to already confused people. I also appreciate that you > >> >> > want to reserve the word "real" for the proper, invariant, > >> >> > character- > >> >> > ristics.
> >> >> It is not that "I" want to reserve the word "real" for proper, > >> >> invariant > >> >> characteristics. The issue is what your readers expect the word to > >> >> mean, > >> >> and how > >> >> THEY will interpret your words. As I said, this varies a lot among > >> >> different > >> >> readers, which implies that the usage of such ambiguous words should > >> >> either be > >> >> avoided, or explained carefully and completely such that the ambiguity > >> >> is > >> >> resolved by the author. As words like "real" and "physical" add little > >> >> or > >> >> no > >> >> value, I find that avoiding them is usually better than explaining > >> >> them.
> >> >> Among experts, who are clearly aware of the difficulties of coordinate > >> >> dependencies in descriptions, "real" generally does apply only to > >> >> proper, > >> >> invariant characteristics of objects. Among non-experts this most > >> >> definitely is > >> >> not so.
> >> >> Tom Roberts
> >> > If light moves
> >> It better well had move :) Which direction is it moving?
> >> > and matter moves
> >> Relative to whom? And in which direction?
> >> > light will take a little more time to > >> > reach the matter that has moved.
> >> More time than what?
> >> > This effects simultaneity and > >> > nonsimultaneity principle.
> >> Don't know if it does, or in what way, as your statement is a bit vague- > >> Hide quoted text -
> >> - Show quoted text -
> > Matter moves in three dimensions with a direction.
> Relative to whom?
> > It can catch up to > > the movement of light by this.
> Matter cannot "catch up to" light, because light is faster than matter
You are an idiot. Matter has motion through the space light is moving through.
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