Three Experiments Challenging SRT

[rpenner]

You're making a mistake 1st years, learning special relativity for the first time, shouldn't even be making. The 'twin paradox' is not an actual paradox, it is called it because it runs counter to our intuition but it isn't logically inconsistent. If you could do the special relativity calculations you'd find that you cannot have both twins meet up again and them both be younger than the other. One and only one is always younger than the other. Which one is the younger one is also simple to work out. Saying "The twin paradox invalidates special relativity!" is just plain ignorant.

OK

Discuss it.

Which of the two of the twins will be younger than?
And - why?

Hi Masterov;

That's a question I too have always wondered about. When (if ?) Alpha Numeric replies, I hope he also includes a simplistic answer, to cater for those who are quite untrained / ignorant in these areas, though nonetheless interested (me for instance).

Special relativity teaches us that the elapsed time experienced by an object moving inertially between events A and B is, in any inertial coordinate system:
$$\tau = \frac{1}{c} \sqrt{c^2 (t_B - t_A)^2 - (x_B - x_A)^2 - (y_B - y_A)^2 - (z_B - z_A)^2} \equiv \frac{1}{c} \sqrt{c^2 (\Delta t)^2 - (\Delta x)^2 - (\Delta y)^2 - (\Delta z)^2} $$
So it's a good thing that all inertial coordinate systems agree on the value of this number because any two events described in any two coordinate systems:
$$c^2 (\Delta t)^2 - (\Delta x)^2 - (\Delta y)^2 - (\Delta z)^2 = c^2 (\Delta t')^2 - (\Delta x')^2 - (\Delta y')^2 - (\Delta z')^2$$

So the reason "why" the twin paradox always has one and only one answer of which twin is younger and by how much is one of space-time (hyperbolic) geometry.

Imagine a triangle of slower-than-light paths through space time. You can get from A to B via an inertial path, or you can get from A to C and then from C to B.
So the twin paradox is equivalent to saying that the inertial path has the largest proper time of any slower-than-light path from A to B.
Or "the straight line is the longest path between to points in space-time."
Or $$\tau_{AB} \ge \tau_{AC} + \tau_{CB}$$ which I shall demonstrate in a coordinate system.
Let
$$U = \sqrt{u_x^2 + u_y^2 + u_z^2} < c \\ V = \sqrt{v_x^2 + v_y^2 + v_z^2} < c \\ \begin{pmatrix} t_C - t_A \\ x_C - x_A \\ y_C - y_A \\ z_C - z_A \end{pmatrix} = \begin{pmatrix} 1 \\ u_x \\ u_y \\ u_z \end{pmatrix} \Delta t_{AC} \\ \begin{pmatrix} t_B - t_C \\ x_B - x_C \\ y_B - y_C \\ z_B - z_C \end{pmatrix} = \begin{pmatrix} 1 \\ v_x \\ v_y \\ v_z \end{pmatrix} \Delta t_{CB}$$
Then it follows that:
$$ -c^2 \lt - U V \leq \vec{u} \cdot \vec{v} = u_x v_x + u_y v_y + u_z v_z \leq U V \lt c^2
\\ \begin{pmatrix} t_B - t_A \\ x_B - x_A \\ y_B - y_A \\ z_B - z_A \end{pmatrix} = \begin{pmatrix} \Delta t_{AC} + \Delta t_{CB} \\ u_x \Delta t_{AC} + v_x \Delta t_{CB} \\ u_y \Delta t_{AC} + v_y \Delta t_{CB} \\ u_z \Delta t_{AC} + v_z \Delta t_{CB} \end{pmatrix}
\\ \tau_{AC} = \sqrt{1 - \frac{u_x^2 + u_y^2 + u_z^2}{c^2}} \Delta t_{AC} = \sqrt{1 - \frac{U^2}{c^2}} \Delta t_{AC}
\\ \tau_{CB} = \sqrt{1 - \frac{v_x^2 + v_y^2 + v_z^2}{c^2}} \Delta t_{CB} = \sqrt{1 - \frac{V^2}{c^2}} \Delta t_{CB}
\\ \tau_{AB} = \sqrt{( \Delta t_{AC} + \Delta t_{CB} )^2 - ( \frac{u_x}{c} \Delta t_{AC} + \frac{v_x}{c} \Delta t_{CB} )^2 - ( \frac{u_y}{c} \Delta t_{AC} + \frac{v_y}{c} \Delta t_{CB} )^2 - ( \frac{u_z}{c} \Delta t_{AC} + \frac{v_z}{c} \Delta t_{CB} )^2 }
\\ \tau_{AB} = \sqrt{(1 - \frac{u_x^2+u_y^2+u_z^2}{c^2})(\Delta t_{AC})^2 + 2 (1 - \frac{u_x v_x + u_y v_y + u_z v_z }{c^2}) \Delta t_{AC} \Delta t_{CB} + (1 - \frac{v_x^2+v_y^2+v_z^2}{c^2})( \Delta t_{CB} )^2 }
\\ \tau_{AB} = \sqrt{(1 - \frac{U^2}{c^2})(\Delta t_{AC})^2 + (1 - \frac{V^2}{c^2})( \Delta t_{CB} )^2 + 2 (1 - \frac{\vec{u} \cdot \vec{v}}{c^2}) \Delta t_{AC} \Delta t_{CB} }
$$
So
$$ \tau_{AC} + \tau_{CB} = \sqrt{(\tau_{AC} + \tau_{CB})^2}
\\ \tau_{AC} + \tau_{CB} = \sqrt{ (1 - \frac{U^2}{c^2})(\Delta t_{AC})^2 + (1 - \frac{V^2}{c^2})( \Delta t_{CB} )^2 + 2 \sqrt{1 - \frac{U^2}{c^2}} \sqrt{1 - \frac{V^2}{c^2}} \Delta t_{AC} \Delta t_{CB} }
\\ \tau_{AB} = \sqrt{ ( \tau_{AC} + \tau_{CB} )^2 + 2 \Delta t_{AC} \Delta t_{CB} ( 1 - \sqrt{1 - \frac{U^2}{c^2}} \sqrt{1 - \frac{V^2}{c^2}} - \frac{\vec{u} \cdot \vec{v}}{c^2} ) }$$

Observe that $$ \tau_{AB} \lt \tau_{AC} + \tau_{CB} $$ (which is the opposite of what we wish to show) requires:
$$0 \leq 1 - \frac{\vec{u} \cdot \vec{v}}{c^2} \lt \sqrt{1 - \frac{U^2}{c^2}} \sqrt{1 - \frac{V^2}{c^2}} $$
but
$$ 0 \leq 1 - \frac{UV}{c^2} \le 1 - \frac{\vec{u} \cdot \vec{v}}{c^2}$$
and
$$ ( 1 - \frac{UV}{c^2} )^2 = 1 + \frac{U^2V^2}{c^4} - \frac{2 U V}{c^2} \ge 1 + \frac{U^2V^2}{c^4} - \frac{U^2 + V^2}{c^2} = \left( \sqrt{1 - \frac{U^2}{c^2}} \sqrt{1 - \frac{V^2}{c^2}} \right)^2$$
because $$0 \ge - \frac{ (U - V)^2 }{c^2} $$

Therefore $$ \tau_{AB} \ge \tau_{AC} + \tau_{CB} $$.

And so the statement "An inertial path between two causality related events is the path with the longest elapsed proper time" does not depend on any of the three legs of the triangle being at rest in the chosen coordinate system. It is a matter of simple (hyperbolic) geometry and doesn't have anything to do with coordinates at all. Coordinates only help in specifying precisely which events we are talking about so we can calculate exactly how different the twin's ages are when they reunites at the same event in space-time (B).

 

[rpenner]

Since I have mostly given up on this internet forum having any moderator fairness and objectivity,

Meaning the moderators discriminate against unevidenced hypotheses like conspiracy theories and hypotheses that run counter to evidence, like absolute time.

For example, if (as SRT theory would have it) both motion and distance is 'only relative' between the objects involved, then how can each one say which of the two (stay home and traveling) twins is actually 'moving/accelerating' and which one is 'not' (each twin in a space ship and one moving off by accelerating away....that way all GR, ie planets etc, complications absent)?

Descriptions of motion and descriptions of distance depend on which inertial coordinate system one is using which differ in what the standard of rest is. But different inertial coordinate systems all agree on what motions constitute inertial motion -- which is privileged on both Newtonian (F=0) and special relativity ( $$\Delta \tau_{\textrm{inertial}} = \textrm{max}\limits _{\textrm{all} \; \textrm{paths}} \Delta \tau$$ ).

Reality Check be aware that they will probably try to goad you into participating in this thread with the motive to have it locked and discarded. My advice is to avoid being goaded into reacting to them if you can ...they will no doubt attack your post so be aware.....

The mysterious "they" seems to be motivated by unclear thinking which begets unclear communication.

No loss to science discourse if such a site ....

... enforces standards?

In practice, which one had the greater relative motion, when compared to their shared state at the beginning and end, can only be determined by comparing their clocks. The hypothetical is generally defined to begin and end in an idealized frame of reference at rest relative to the thought experiement.

Or rather, for the triangle of inertial paths, A->B, A->C and C->B one is always free to describe the physics from an inertial coordinate system where A->B is an inertial path of zero velocity.

Acceleration is consistent with SR only under a few unique circumstances.

This seems like a mistatement.

A couple would be where gravity is also involved as in an orbit

Except that this is a job for GR, not SR.

and the second perhaps a particle accelerator where a particle's path is bent by magnetic fields.

This case is fully described by SR.

In both of those cases it appears that the GR effects associated with the principle of equivalence,

True only for slow moving bodies in gravitation which is why Einstein's 1911 paper on the bending of starlight was wrong.

Abscent either of those situations, acceleration would not affect time dilation and length contraction in the same way that a constant velocity does.

I disagree. The path integral $$ \Delta \tau = \int_A^B \sqrt{1 - \left( \frac{\vec{u}(t)}{c} \right)^2} dt$$ is the same for inertial and accelerated world lines in special relativity.

The basic or fundamental Twins Thought Experiment, does not include accelerations.

Because accelerations require calculus of variations to get the same basic result as I described in my previous post.

A second thing that actually addresses most of the rest of your post, aside from the continued inclusion of accelerations, is that SR begins with a statement that all interial frames of reference are equally valid. What this is saying, is that no one is ever actually at rest. No one can claim a preferred frame of reference.

A key point in both Galilean and Special Relativity. All inertial states of motion are equivalent.

RealityCheck, I don't believe that there are many physicists who really believe that space is empty. GR certainly assumes that space interacts dynamically with matter... And there has been a great deal of work attempting to describe inertia and gravity, which addresses the same issue, from the perspective of QM. It would be a side track here but look a few of the papers discussing inertia and ZPF or vacuum energy...

However, the geometry of empty space doesn't require space to be filled with a substance.

And we are always talking about relative perspectives. Other than in some of these discussions I don't think that any physicist is saying that the physical distances between two objects changes due to the motion of a third frame of reference. Though I believe everyone can agree that, distances may appear different from different inertial frames of reference.

Because coordinates are not real -- they are man-made inventions to describe geometry in the language of number and algebra.

 

[Masterov]

Solid residue
Scientist defends Truth.
Fanatic - religious dogma.
Ó÷åíûé çàùèùàåò Èñòèíó.
Ôàíàòèê - ðåëèãèîçíûå äîãìû.
​

 

[Masterov]

See post #602, about moles-prople.

 

[rpenner]

Not sure how simplistic you want but here is the simplest answer I know. The stay at home twin ages more than the traveling twin because the stay at home twin remains in his inertial frame and the traveling twin accelerates to a different inertial frame and then must decelerate back to the original inertial frame.

Exactly. If $$\vec{u} = \vec{v}$$ then $$\frac{\vec{u} \Delta t_{AC} + \vec{v} \Delta t_{CB}}{ \Delta t_{AC} + \Delta t_{CB}} = \vec{u}$$ and A->B, A->C and C->B are all the same state of inertial motion and there is no difference of elapsed proper time.

You state that time of spaceship are slower.

What (what is name of it? what and in what physical quantities measure it? what does it depend?) physical parameter responsible for the rate of flow of time in a space ship?

As has been stated in many ways many times before -- you lose the essence of special relativity if all you think about is time dilation.

Imagine a large, irregular sheet of paper. Alice and Bob each pick a different point as the origin of a 2-dimensional Euclidean coordinate system. Each coordinate system labels each point of the paper with two coordinates. A formula lets us convert Alice's coordinates (x,y) to Bob's coordinates (x',y').
$$\begin{pmatrix} x' \\ y' \end{pmatrix} = \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} & \frac{-m}{\sqrt{1 + m^2}} \\ \frac{m}{\sqrt{1 + m^2}} & \frac{1}{\sqrt{1 + m^2}} \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix} + \begin{pmatrix} \chi \\ \upsilon \end{pmatrix}$$
And coordinate differences transform like:
$$\begin{pmatrix} \Delta x' \\ \Delta y' \end{pmatrix} = \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} & \frac{-m}{\sqrt{1 + m^2}} \\ \frac{m}{\sqrt{1 + m^2}} & \frac{1}{\sqrt{1 + m^2}} \end{pmatrix} \begin{pmatrix} \Delta x \\ \Delta y \end{pmatrix}$$
or back the other way
$$\begin{pmatrix} \Delta x \\ \Delta y \end{pmatrix} = \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} & \frac{m}{\sqrt{1 + m^2}} \\ \frac{-m}{\sqrt{1 + m^2}} & \frac{1}{\sqrt{1 + m^2}} \end{pmatrix} \begin{pmatrix} \Delta x' \\ \Delta y' \end{pmatrix}$$

Naturally, if Alice measures out $$\begin{pmatrix} \Delta x \\ \Delta y \end{pmatrix} = \begin{pmatrix} 1 \\ 0 \end{pmatrix}$$, Bob measures this same line as $$\begin{pmatrix} \Delta x' \\ \Delta y' \end{pmatrix} = \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} \\ \frac{m}{\sqrt{1 + m^2}} \end{pmatrix}$$.
And if Bob measures out $$\begin{pmatrix} \Delta x' \\ \Delta y' \end{pmatrix} = \begin{pmatrix} 1 \\ 0 \end{pmatrix}$$, Alice measures this same line as $$\begin{pmatrix} \Delta x \\ \Delta y \end{pmatrix} = \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} \\ \frac{-m}{\sqrt{1 + m^2}} \end{pmatrix}$$.

This does not mean that Alice and Bob both have a x-dilation of $$\frac{1}{\sqrt{1 + m^2}}$$ with respect to each other -- that is just a small part of the whole story. It is a piece so small as to be a gross distortion if substituted for a complete understanding. The whole story includes

• $$\sqrt{(\Delta x)^2 + (\Delta y)^2} = \sqrt{(\Delta x')^2 + (\Delta y')^2}$$ for all straight lines,
• that in terms of this invariant the straight line between two points has the lowest total of any path connecting the points ,
• the relation is a rotation
• what is rotated can be rotated back, and
• this is a relative rotation not connected with any absolute coordinate system, but only the choices made by Alice and Bob.

$$\begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} & \frac{-m}{\sqrt{1 + m^2}} \\ \frac{m}{\sqrt{1 + m^2}} & \frac{1}{\sqrt{1 + m^2}} \end{pmatrix} = \begin{pmatrix} \cos \; \tan^{\tiny -1} m & - \sin \; \tan^{\tiny -1} m \\ \sin \; \tan^{\tiny -1} m & \cos \; \tan^{\tiny -1} m \end{pmatrix}$$
$$ \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} & \frac{m}{\sqrt{1 + m^2}} \\ \frac{-m}{\sqrt{1 + m^2}} & \frac{1}{\sqrt{1 + m^2}} \end{pmatrix} \begin{pmatrix} \frac{1}{\sqrt{1 + m^2}} & \frac{-m}{\sqrt{1 + m^2}} \\ \frac{m}{\sqrt{1 + m^2}} & \frac{1}{\sqrt{1 + m^2}} \end{pmatrix} = \begin{pmatrix} \frac{1 + (m)(m)}{1 + m^2} & \frac{m -m}{1 + m^2} \\ \frac{m - m}{1 + m^2} & \frac{(-m)(-m) + 1}{1 + m^2} \end{pmatrix} = \begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix} $$

The whole story of relativity includes

• $$\sqrt{(c \Delta t)^2 - (\Delta x)^2 - (\Delta y)^2 - (\Delta z)^2} = \sqrt{(c \Delta t')^2 - (\Delta x')^2- (\Delta y')^2- (\Delta z')^2}$$ for all inertial paths,
• that in terms of this invariant the inertial path between two events has the highest total of any path connecting the events ,
• the relation is a hyperbolic rotation
• what is hyperbolic rotated can be hyperbolic rotated back, and
• this is a relative hyperbolic rotation not connected with any absolute coordinate system, but only the choices made by Alice and Bob.

$$\begin{pmatrix} \frac{1}{\sqrt{1 - \beta^2}} & \frac{\beta}{\sqrt{1 - \beta^2}} \\ \frac{\beta}{\sqrt{1 - \beta^2}} & \frac{1}{\sqrt{1 - \beta^2}} \end{pmatrix} = \begin{pmatrix} \cosh \; \tanh^{\tiny -1} \beta & \sinh \; \tanh^{\tiny -1} \beta \\ \sinh \; \tanh^{\tiny -1} \beta & \cosh \; \tanh^{\tiny -1} \beta \end{pmatrix}$$

I asked you to show us a data of the measurements of relativistic effects, which were obtained by GPS satellites.
Where are it?

Get a clue. There's every detail available on the net. Do this simple project to find out why the satellite and earth clock tick rates won't stay synched when they're separated. Pick 'Student Project on the Global Positioning System'. I doubt you can do this project since your algebra is so bad.
http://www.eftaylor.com/download.html#general_relativity
There's two time dilation components. Relative velocity for SR and gravitational time dilation for GR. The SR and GR time dilation components sum. Don't want either in the analysis leave it out.

Stonewall Masterov. GPS stands for Global Positioning System. I'll link it for you.
http://www.eftaylor.com/pub/projecta.pdf

I prefer the review paper: http://relativity.livingreviews.org/Articles/lrr-2003-1/ "Relativity in the Global Positioning System"
Section 5 has this paragraph about a famous measurement.

There is an interesting story about this frequency offset. At the time of launch of the NTS-2 satellite (23 June 1977), which contained the first Cesium atomic clock to be placed in orbit, it was recognized that orbiting clocks would require a relativistic correction, but there was uncertainty as to its magnitude as well as its sign. Indeed, there were some who doubted that relativistic effects were truths that would need to be incorporated [5]! A frequency synthesizer was built into the satellite clock system so that after launch, if in fact the rate of the clock in its final orbit was that predicted by general relativity, then the synthesizer could be turned on, bringing the clock to the coordinate rate necessary for operation. After the Cesium clock was turned on in NTS-2, it was operated for about 20 days to measure its clock rate before turning on the synthesizer [11]. The frequency measured during that interval was +442.5 parts in 10[sup]12[/sup] compared to clocks on the ground, while general relativity predicted +446.5 parts in 10[sup]12[/sup]. The difference was well within the accuracy capabilities of the orbiting clock. This then gave about a 1% verification of the combined second-order Doppler and gravitational frequency shift effects for a clock at 4.2 earth radii.

See [11] Buisson, J.A., Easton, R.L., and McCaskill, T.B., “Initial Results of the NAVSTAR GPS NTS-2 Satellite”, in Rueger, L.J. et al., ed., 9th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, Proceedings of the meeting, held at NASA Goddard Space Flight Center, November 29 – December 1, 1977, pp. 177–200, (Technical Information and Administrative Support Division, Goddard Space Flight Center, Greenbelt, MD, 1978). if you want further details.

 

[OnlyMe]

This seems like a mistatement.

Or just plain wrong!

Except that this is a job for GR, not SR.

This case is fully described by SR.

To be kind to myself, I'd say I was unclear. I was attempting to separate acceleration associated with the curved paths, in those two situations, from acceleration generally. Still ignoring the time dilation due to gravity in the first.

However, the geometry of empty space doesn't require space to be filled with a substance.

I did not intend to imply that it did. The fact that GR does not and the idea has so much historical baggage attached, may be part of the difficulty in reconciling QM and GR. There is a more or less philosophical question involving how we define space and what it is. What we think of and how we define and treat both space and time, doesn't always seem to be consistent between disciplines.

You are correct on the issue of acceleration, velocity and SR. I was not expressing my intent well and it is no longer of any import or significance.

 

[rpenner]

In Master Theory there are two types of coordinates: real and visible.

Real coordinates are satisfy to Galilean transformations.

Relativistic effects are the visual effects.
Relativistic effects are physical phenomena.

This was incorrect when Masterov wrote it (June 2012) and still incorrect today when Masterov inappropriately PMed me about it.

coordinates are not real -- they are man-made inventions to describe geometry in the language of number and algebra.

There is no such thing as a real coordinate system. In Newtonian theory or Special Relativity, all inertial coordinate systems are special in that inertial motion in an inertial coordinate system is always linear motion. Further, Galilean and Lorentz transformations give us two separate alternatives for converting between inertial coordinate systems. Further, all experiments precise enough to favor one alternative over the other favors Special Relativity over Galileo and Newton.

Master theory is not up to the task because what is Master-transformed cannot be Master-transformed back such that Alice to Bob to Alice is not the same as Alice to Alice (i.e. no transformation).

Space time has, under every test we have ever run, the same local structure as the hyperbolic geometry of Minkowski space. So if we do form different inertial coordinate systems we can be assured that $$c^2 ( \Delta t)^2 - \vec{\Delta x}^2 = c^2 ( \Delta t')^2 - \vec{\Delta x'}^2$$ and calling the different man-made coordinate systems names like "real" or "visual" doesn't change the fact they are both equally man-made inventions bases on human choices of origins and standards of rest.

Why would Masterov want to criticize special relativity when he has never understood it, or coordinates, or linear algebra or analytic geometry? For years he raise the same feeble strawmen and kicks them over without doing the slightest damage to the world of facts and engineering that demonstrate special relativity works.

 

[Masterov]

Why would Masterov want to criticize special relativity when he has never understood it, or coordinates, or linear algebra or analytic geometry?

You're the first one who told me about this.
You have no any arguments in physics, and you look them up somewhere else.

============================
Вы первый, кто мне об этом сказал.
У вас нет аргументов в физике, и вы ищете их где-то ещё.

Why would Masterov want to criticize special relativity?

Strange question, is not it?
What's not to understand? Masterov have both experimental results and theoretical justification.
Why this question?

Very typical question in a situation in Confessors SRT code is not provided arguments.
This question is significant.
In Russia, the accusation of anti-Semitism after of this question (as a rule).
(But what to do if there are no more arguments?)

An accusations of anti-Semitism are another (often used in Russia) vile method of protecting SRT.
======================

Странный вопрос, не так ли?
Что тут не понимать? Masterov и экспериментальные результаты привёл и теоретические обоснования выложил.
Зачем этот вопрос?

Этот вопрос весьма характерный в ситуации, кода у исповедников SRT не оказывается аргументов.
Этот вопрос является знаковым.
В России (как правило) за этим вопросом следует обвинение в антисемитизме.
(А что делать, если аргументов больше нет?)

Обвинение в антисемитизме является ещё одним (часто применяемым в России) подлым методом защиты SRT.

 

[Masterov]

rpenner, your exercises with Lorentz transformations have no big physical meaning, because you are operating unreal coordinates. Lorentz transformations do convert visual coordinates and visual time. Visual coordinates do not have much physical meaning, as well as the acoustic coordinates.
Only for special applications it makes sense to consider the visual coordinates.
============================
rpenner, Ваши упражнения с преобразованиями Лоренца никакого физического смысла не имеют, поскольку вы оперируете нереальными координатами. Преобразованиями Лоренца оперируют визуальными координатами и визуальным временем. Визуальные координаты не имеют большого физического значения, так же как и акустические координаты.
Только для специальных задач имеет смысл рассматривать визуальные координаты.

 

[LiverOil]

No, I have had other things to do with my time. I just finished a project for the European Space Agency. They consider me a good enough scientist to be worth paying.

Oh cool, I never knew there was an European space agency. Why haven't they gone to the moon or mars? And why do they pay a physicist to do work for them?

--
And if you had lived my life, you would understand my responsibility to the Federation.

 

[Masterov]

Oh cool, I never knew there was an European space agency. Why haven't they gone to the moon or mars? And why do they pay a physicist to do work for them?

You are not a physicist?

 

[RealityCheck]

Hi przyk.

Masterov has asked you this more than once now...

przyk, уou argue that the physical properties of matter are change by acceleration, and it leads to slower time?

1. What are these physical properties of matter. Name it.

2. Assume that the acceleration can result to time dilation.
One would assume that the braking do time acceleration.
But braking is no different from the acceleration.
The difference has in the direction and in the terminology.

If the acceleration do time dilation, then what do time-acceleration, to return time to its original state?

Can you answer it directly without invoking explanations which do not address the point of his question as put? Just saying electromagnetism etc etc does not answer what causes the original acceleration to dilate time and the subsequent DE-celeration to UN-dilate it back to the starting rate. What is that parameter unique to each whatever frame they are in?[/b]

I am most curious to see the answer to THAT point/question rather than going all around the houses to avoid doing so as you and others seem happy to do again and again.

 

[RealityCheck]

Hi rpenner.

Yes, we all know by now your own personal/scientific ethics/standards. Nuff said about that.

As for answering Masterov's question, I refer you to my above post to przyk. Neither his allusion to electromagnetism or anything else has answered the question as put by Masterov.

And neither does your mathematical calculations in hyperbolic geometry answer it.

It would make a nice change if someone who professes to be the 'expert' would actually answer the question as put rather than beating all around it and pretending they have done so.

Thanks in anticipation of an expert opinion to the point without all the personal sideplay/evasion tactics.

 

[przyk]

Hi przyk.

Masterov has asked you this more than once now...

Can you answer it directly without invoking explanations which do not address the point of his question as put? Just saying electromagnetism etc etc does not answer what causes the original acceleration to dilate time and the subsequent DE-celeration to UN-dilate it back to the starting rate. What is that parameter unique to each whatever frame they are in?[/b]

I am most curious to see the answer to THAT point/question rather than going all around the houses to avoid doing so as you and others seem happy to do again and again.

I haven't bothered with that question because it is the wrong question to ask in the first place: relativistic effects are directly associated with relative velocity, not acceleration. In fact, if we do the exercise of working out e.g. what happens to the orbital period of an electron orbiting a nucleus as we accelerate the whole system, normally to get the time dilation factor predicted by relativity we have to assume that the whole system is being accelerated gently enough so that any additional effects due to acceleration are negligible.

If I quickly accelerate you at a rate of 10000 g up to a speed near the speed of light, I don't expect the result just to be you continuing to age as you would otherwise have done, except more slowly. I would instead expect the rapid acceleration to kill you outright, and for whatever was left moving near the speed of light not to resemble you much as you are now at all.

 

[RealityCheck]

I haven't bothered with that question because it is the wrong question to ask in the first place: relativistic effects are directly associated with relative velocity, not acceleration. In fact, if we do the exercise of working out e.g. what happens to the orbital period of an electron orbiting a nucleus as we accelerate the whole system, normally to get the time dilation factor predicted by relativity we have to assume that the whole system is being accelerated gently enough so that any additional effects due to acceleration are negligible.

If I quickly accelerate you at a rate of 10000 g up to a speed near the speed of light, I don't expect the result just to be you continuing to age as you would otherwise have done, except more slowly. I would instead expect the rapid acceleration to kill you outright, and for whatever was left moving near the speed of light not to resemble you much as you are now at all.

Now we are getting to the nub of why that question needed to be asked. For if as in SR all motion of a body is merely 'relative' to some other body, then there is no basis for saying that acceleration/deceleration affecting clocks per se so that they read differently when accelerated to some constant velocity 'relative' to the other body and then DE-accelerated to a velocity to coincide with that other body at the end of the 'round trip'.


See? There must be another factor at play 'with respect to space' and not just 'with respect to other body'.

And anyway, when one invokes just such acceleration frames etc to 'explain' the 'paradox' of SR, then it is not I or Masterov who has introduced those other factors; it is the 'SR explainers' who introduced it.

You can't have it both ways: one way you claim no other factors are relevant in SR; the other way you depend on such other factors to 'explain' SR illusions of both clocks being affected solely due to SR...BUT now you tacitly admit that acceleration/deceleration/velocities/motion per se 'with respect to "something else"' really IS THE factor which makes the reality effects/explanation trump the purely SR abstract relative treatment/explanation (although you still haven't answered Masterov's question/point about the unique parameters affecting either body's time (acceleration caused 'dilation/slowing'; deceleration caused 'recovery/re-quickening' of time rate in the traveling frame as you have just confirmed happens when acceleration/deceleration leads to new/recovered constant velocity in 'round trip').

Thanks. You have been most helpful.

 

[Lakon]

Though a mere nonscientific but nonetheless very interested observer, I'm following this thread with great interest and am really enjoying it.

I think Reality Check's two most recent posts are very civil, cogent, and really, get to the heart of the problem as expressed by Masterov.

Hopefully the respondants can answer it in an equally cogent and civil manner.

 

[Mazulu]

However, the geometry of empty space doesn't require space to be filled with a substance.

The geometry for our universe could not exist without a support structure for light/electromagnetic fields. That's why time dilation and length contraction are tied to the speed of light. That's why matter and anti-matter annihilate in a flash of light (gamma rays).

 

[przyk]

For if as in SR all motion of a body is merely 'relative' to some other body, then there is no basis for saying that acceleration/deceleration affecting clocks per se so that they read differently when accelerated to some constant velocity 'relative' to the other body and then DE-accelerated to a velocity to coincide with that other body at the end of the 'round trip'.

I don't see your point. In SR, all relativistic effects depend on relative velocity, but the effects, such as time dilation and length contraction, are also themselves relative.

And anyway, when one invokes just such acceleration frames etc to 'explain' the 'paradox' of SR, then it is not I or Masterov who has introduced those other factors; it is the 'SR explainers' who introduced it.

We introduce it because the normal, simple descriptions of relativistic effects are all given relative to inertial (non-accelerating) coordinate systems. So when someone tries to use e.g. the time dilation formula in the travelling twin's frame in the twin paradox, and "deduces" that the earth bound twin should be younger when the travelling twin returns, the simple resolution to that is to point out that the conclusion simply doesn't follow because they used equations specific to inertial frames in an accelerating frame.

Of course, it's still possible to look in more detail at what happens from the perspective of an accelerating observer, though we usually avoid that because it's not all that interesting or illuminating. If you insist on doing it anyway, then you find that the "resolution" to the paradox is that the accelerating observer's concept of simultaneity changes as their relative velocity changes. This is important because when the travelling twin asks "how old is my twin on Earth right now", they're invoking a notion of simultaneity or synchronicity to compare their own age with the age of their twin on Earth who is a long distance away. As they accelerate, their idea of "now" when comparing the age of their twin on Earth with their own age changes. If you account for that literally, then you find that the Earth twin ages very rapidly from the travelling twin's perspective as the travelling twin accelerates back toward Earth.

The reason I say this isn't very interesting or illuminating is because it doesn't describe literally what the travelling twin would see if they looked at their twin on Earth through a telescope (they both see each other Doppler shifted), and they wouldn't be able to measure it directly in any practical way. Think of how you'd do that if you were the travelling twin: you would need a whole series of clocks suspended throughout space but moving along with you (so you could always measure your twin's age compared with one of your own clocks that was passing very near him at the time), and always carefully kept in their correct positions relative to each other and with the correct synchronisation enforced, at least during the periods of your trip when you weren't accelerating. That's obviously not a very practical arrangement, and the fact you'd measure your Earth twin to be ageing very rapidly just because you carefully kept your clocks synchronised a certain way isn't all that illuminating.

 

[Masterov]

Hi przyk.

Masterov has asked you this more than once now...

przyk, уou argue that the physical properties of matter are change by acceleration, and it leads to slower time?

1. What are these physical properties of matter. Name it.

2. Assume that the acceleration can result to time dilation.
One would assume that the braking do time acceleration.
But braking is no different from the acceleration.
The difference has in the direction and in the terminology.

If the acceleration do time dilation, then what do time-acceleration, to return time to its original state?

Can you answer it directly without invoking explanations which do not address the point of his question as put? Just saying electromagnetism etc etc does not answer what causes the original acceleration to dilate time and the subsequent DE-celeration to UN-dilate it back to the starting rate. What is that parameter unique to each whatever frame they are in?[/b]

I am most curious to see the answer to THAT point/question rather than going all around the houses to avoid doing so as you and others seem happy to do again and again.

1. Thank you for your post. I'm tired demand the answer to this question. Maybe we (two) will be able to get them to respond or admit defeat.

2. At the moment my opponents put pressure on the brain moderator, requiring ban for me. SRT-lobbyists do not stop at nothing to protect the religious doctrine of Einstein.

 

[Masterov]

Hi przyk.

Masterov has asked you this more than once now...

Can you answer it directly without invoking explanations which do not address the point of his question as put? Just saying electromagnetism etc etc does not answer what causes the original acceleration to dilate time and the subsequent DE-celeration to UN-dilate it back to the starting rate. What is that parameter unique to each whatever frame they are in?[/b]

I am most curious to see the answer to THAT point/question rather than going all around the houses to avoid doing so as you and others seem happy to do again and again.

I haven't bothered with that question because it is the wrong question to ask in the first place: relativistic effects are directly associated with relative velocity, not acceleration.

Speeds ​​of the brothers are identical.
If the deceleration time depends on the speed, then why this slowdown has only one brother?