Chapter: The mechanisms behind Non-Simultaneity
Hans de Vries
mechanisms behind non-simultaneity.
http://physics-quest.org/Book_Chapter_Non_Simultaneity.pdf
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
Some feedback would be welcome.
Regards, Hans
__________________
http://www.physics-quest.org
Hans de Vries
http://physics-quest.org/Book_Chapter_Non_Simultaneity.pdf
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
Regards, Hans
_____________________________
http://www.physics-quest.org
glird
>
> < I recently finished the introductory chapter on the mechanisms behind non-simultaneity.
http://physics-quest.org
/Book_Chapter_Non_Simultaneity.pdf
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")!
glird
Hans de Vries
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.
(http://physics-quest.org/Book_Chapter_Non_Simultaneity.pdf)
> 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.
See for instance the first section of:
http://physics-quest.org/Book_Chapter_EM_LorentzContr.pdf
The different simultaneities in different reference frames
reverse this physical effect of Lorentz contraction.
This can be seen by looking at figure 4.25 at page 33:
http://physics-quest.org/Book_Chapter_Non_Simultaneity.pdf
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).
Regards, Hans
_______________________________
http://www.physics-quest.org/
Tom Roberts
> 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.
Tom Roberts
Inertial
news:H-2dnf4lgO1...@giganews.com...
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.
Hans de Vries
> 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)
>
> 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.
See the two chapters on Lorentz contraction and Time dilation
from this perspective: (section 2.1 derives Lorentz contraction)
http://physics-quest.org/Book_Chapter_EM_LorentzContr.pdf
http://physics-quest.org/Book_Chapter_Time_Dilation.pdf
The chapter on simultaneity is written in the same context as
the two above, linking the wave equations to non-simultaneity.
http://physics-quest.org/Book_Chapter_Non_Simultaneity.pdf
Regards, Hans
__________________________________
http://www.physics-quest.org/
Androcles
"Hans de Vries" <hans.de....@gmail.com> wrote in message
news:4a7c9a4a-56f0-43f5...@s15g2000yqs.googlegroups.com...
> 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.
>
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.
Hans de Vries
>
> 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
---------------------------------------------------------
Androcles
Hi, Androcles
Regards, Hans
=============================================
Bwahahahahaha!
Which magic hat did you pull gamma and beta from?
http://tvtropes.org/pmwiki/pub/images/avernum4_rabbitinthehat.png
The underlying problem is that some idiots don't know the
difference between beta and gamma. Be more careful.
Bruce Richmond
> "Tom Roberts" <tjroberts...@sbcglobal.net> wrote in message
>
> - 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.
Simple Simon
This should be:
x = gamma(x'-beta^2 gamma x)
Hans de Vries
>> x = gamma(x'-beta^2 gamma x)
Correct, Thanks for correcting the typo. At least somebody
who reads this seriously :^)
Regards, Hans
_____________________________________
http://www.physics-quest.org/
glird
> < 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}
> Tom Roberts
glird
Androcles
On Nov 8, 6:33 pm, "Simple Simon" <pi.r.cubed-nos...@gmail.com> wrote:
> 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.
Hans de Vries
> What hat did you pull your magic gamma from?
Well, if you're serious (?)
1-beta^2 beta^2 1
1 + beta^2 gamma^2 = -------- + -------- = -------- = gamma^2
1-beta^2 1-beta^2 1-beta^2
This is what turns your "multiply by gamma" into a "divide by gamma"
Regards, Hans
_________________________________
http://www.physics-quest.org/
Androcles
On Nov 8, 7:33 pm, "Androcles" <Headmas...@Hogwarts.physics_p> wrote:
> What hat did you pull your magic gamma from?
> Androcles.
Well, if you're serious (?)
1-beta^2 beta^2 1
1 + beta^2 gamma^2 = -------- + -------- = -------- = gamma^2
1-beta^2 1-beta^2 1-beta^2
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?
BURT
> "Hans de Vries" <hans.de.vries...@gmail.com> wrote in messagenews:b01cdaf3-0a94-43cd...@k19g2000yqc.googlegroups.com...
You can move with respect to light. That is the cause of non
simultaneity.
Mitch Raemsch
blackhead
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.
Regards,
Larry
Tom Roberts
>
> 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
BURT
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.
Mitch Raemsch
Inertial
news:b87e84b3-1603-4730...@12g2000pri.googlegroups.com...
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
BURT
> "BURT" <macromi...@yahoo.com> wrote in message
>
> - 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.
Mitch Raemsch
Inertial
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.
Slower than what?
BURT
You are an idiot. Matter has motion through the space light is moving
through.
Mitch Raemsch
>
> > Light then is moving slower to the
> > matter frame.
>
> Slower than what?- Hide quoted text -
Inertial
Nope. Thought you seem to be behaving like one.
> Matter has motion through the space light is moving
> through.
And as the light travels faster than the matter, the matter cannot catch up
to it. Light, however, can catch up to matter.
Think about it, instead of spamming with your nonsense.