Refutation of Special Relativity for Dummies

[RussDill]

Which point do consider invalid? Or do you think that the light-clock principle itself is not consistent with SR, or that SR-simultaneity cannot be applied to the inertial motion of the travelling clock?

You are only listing 2 clocks, but there are 3 clocks. The stationary Earth clock, the outbound clock t1, and the inbound clock t2. T1 and T2 are not the same clock unless you include in it's path an acceleration to change direction.

Do the math again, have Earth and T1 exchange times when T1 passes Earth, have T1 and T2 exchange times when T2 passes T1 on it's way to Earth at a point 100 LY from Earth (in Earth's inertial frame), and then have T2 exchange times with Earth when it passes Earth.

This example includes no acceleration, and the result can be easily computed. The example can also be done with a single clock that stops and turns around at the half way point.

 

[wogoga]

Show your research and your math or give up. You won't win this because you are wrong.

Insofar as your comment represents modern "science", it shows that "science" essentially is based on faith (in authoritative orthodoxy).

You're not paying attention to what each of the two observers will actually see.

In my opinion, you try to rescue Special Relativity by confusing world-map with world-picture. Quotes from Essential Relativity, Wolfgang Rindler, 1977, World-picture and world-map:

"In relativity it is especially important to distinguish between the set of events that an observer sees at one instant and the set of events that the observer considers to have occurred at that instant. What an observer actually sees or can photograph at one instant is called a world-picture. It is a composite of events that occurred progressively earlier as they occurred farther away. For our present purposes it is irrelevant."

"The concept that plays a pervasive role in special relativity is that of the world-map. As the name implies, this may be thought of as a (3-dimensional) map of events, namely those constituting an observer’s instantaneous 3-space t = t₀. It could be produced by having auxiliary observers at the coordinate lattice-points all map their immediate neighborhoods at a pre-determined time t = t₀, and then joining all these local maps into a single global map."

"The world-map is generally what matters."​

There is no contradiction about observers measuring that each others clocks tick slower. That is what SR states !

• For the travelling clock, the clock at rest is running slower during any inertial movements.
  This is standard SR.
• The clock at rest after the whole round trip reads less than the travelling clock.
  This is the twin paradox - the at home twin is younger than the travelling twin!

Your first point is correct:

• For the travelling clock, the clock at rest is running slower during any inertial movements.
  This is standard SR.

Your second point however, despite seemingly being a common-sense conclusion from the first point, is wrong:

• The clock at rest after the whole round trip reads less than the travelling clock.
  This is the twin paradox - the at home twin is younger than the travelling twin!

Correct within "standard SR" is the exact opposite:

• The clock at rest after the whole round trip reads more than the travelling clock.
  This is the twin paradox - the at home twin is older than the travelling twin!

Actually your error is a salient incarnation of the Lorentz-factor confusion I mentioned at the end of post #56.

Cheers, Wolfgang

 

[Reality Check]

Your first point is correct:...

Right, wogoga.
The correct version is:
There is no contradiction about observers measuring that each others clocks tick slower. That is what SR states !

• For the travelling clock, the clock at rest is running slower during any inertial movements.
  This is standard SR.
• The clock at rest after the whole round trip reads more than the travelling clock.
  This is the twin paradox - the at home twin is older than the travelling twin!

You still have an ignorant treatment of the twin paradox as other posters have pointed out. Your personal confusion about the twin paradox does not mean that SR is wrong. As soon as you tried to average over two clocks when there are more in the original twin paradox, you became wrong.

1. The at home twin has a clock for their inertial frame.
2. The travelling twin has a clock for the inertial frame in the outbound leg. They then accelerate to turn around. That is a different inertial frame.
3. The travelling twin has a clock for the inertial frame in the inbound leg.

The twins can then compare times on their clocks as the traveling twin passes Earth. Or the travelling twin can stop - another clock!

 

[Prism]

Just for fun:
http://rationalwiki.org/wiki/Conservapedian_relativity

I won't pretend that I fully get what was said in those paragraphs, but this one section seems weird to me.

"For the first time, scientists have experimentally demonstrated that sound pulses can travel at velocities faster than the speed of light, c. William Robertson's team from Middle Tennessee State University also showed that the group velocity of sound waves can become infinite, and even negative. ... Although such results may at first appear to violate special relativity (Einstein's law that no material object can exceed the speed of light), the actual significance of these experiments is a little different. These types of superluminal phenomena, Robertson et al. explain, violate neither causality nor special relativity, nor do they enable information to travel faster than c. In fact, theoretical work had predicted that the superluminal speed of the group velocity of sound waves should exist. 'The key to understanding this seeming paradox is that no wave energy exceeded the speed of light,' said Robertson."[CP 6]
-----------------------------------------------------------------------------------
Some readers may be misled by this paragraph, which might be interpreted as casting doubt on relativity because the sound velocities measured are greater than the speed of light. In fact, as explained further on in the paragraph, no violation of relativity exists. There are several different methods of measuring the velocity of waves; a few of the most common are group velocity and phase velocity. In some instances, due to the nature of wave behavior and measurement techniques, measurements of both group and phase velocity can exceed c. As fascinating as that behavior is, however, no energy or information is transferred faster than c, in accordance with special relativity.

What differentiates group velocity from velocity, and why can it be said that no information transfers faster than c in those experiments when clearly, we perceive different information in them?

 

[Darwin123]

I won't pretend that I fully get what was said in those paragraphs, but this one section seems weird to me.




What differentiates group velocity from velocity, and why can it be said that no information transfers faster than c in those experiments when clearly, we perceive different information in them?

Group velocity is the velocity of a pulse of light. A pulse is en envelop, etc. The formalism gets lost in mathematics. However, I think of it this way.

Group velocity is velocity of an 'image' made of light. If a film projector is used to project an image of a person on a distant screen, then that image travels on the screen at a certain distance taking an amount of time. The distance divided by time is a sort of group velocity.

Note that the velocity of the image does not necessarily correspond to the velocity of the object that that image is supposed to represent. The image can be speeded up by moving the film faster, or by editing the film by snipping out frames.

The image is physically 'real'. The image is not an 'illusion' in the strictest sense of the word. When the image moves, there are instruments that can measure the speed of the image on the screen.

One can use film to photograph The image. One can use black paper and thermometers to figure out the speed of the image. After all, when the images passes the intensity of light at that spot changes. So the black paper is heated up in a very real way. So 'images' are very real in a physical sense. The existence of an image is 'objective' in the sense of energy density.

However, the image is subjective in the sense of relativity because it does not actually carry information or even energy. It is a concentration of energy that has actually moved from a direction different from the direction that the image is moving.

Want to make a movie image go faster than light? Take a very, very long frame. Take a slide projector. It doesn't even have to be a movie director. Take the slide projector and project the image of a turtle on the screen from a very long distance. For the sake of argument, take a movie projector 10^9 km away from a screen that is 10^10 km long.

Rotate the projector at about 1 radian/second. This is about 53 degrees per second. The image will move on the screen about 10^9 km/second. The speed of light is only 3x10^5 km/second. That image of a turtle on the screen. is much faster than the speed of light.

The image of the turtle is physically real in that the light will heat the screen. The warm spot will 'travel' faster than the speed of light. However, the turtle doesn't carry any information.

The energy that makes up the optical image came from the projector to the screen. The energy of the turtle did not move in the direction of the screen. It actually moved perpendicular to the turtle.

Let us suppose that there are people near the screen who want to send messages faster than the speed of light. The image of the turtle can't carry messages. What they do to the image of the turtle at any one moment doesn't affect the image of the turtle at the next moment. If a person blocks the image in his position at a certain time, the image of the turtle merely reforms a split second later further on down the screen.


The energy from the turtle started out at the projector may 10^4 seconds ago. The energy travelled at the speed of light from the projector to the screen. It did not go faster than the speed of light. However, the image is 'moving' than the speed of light.

Once again. I won't make the mistake of calling the image an illusion. The image is a very objective concentration of energy. However, the image is not a real turtle. A real turtle CAN carry messages, although slower than the speed of light. The image was caused by an event that occurred a long time ago at the projector.

There are other scientists who will confuse the issue by saying the image is not real. Well, an image can store energy. However, the energy can't be released in any way which sends a message faster than the speed of light.

The fast moving turtle can be seen as an example of what I call 'anti-parallax'. The image is moving fast partly because of the large distance between screen and projector. It is not moving fast because energy is moving that fast.

Even a beam of light can't travel as fast as the image of the turtle. Yes, the image is ' from' light energy. However, image wasn't caused solely by the motion of the light energy. It was really caused by the rotation of the projector. The turtle can move hundreds of times faster than the sped of light


The image of the turtle doesn't violate relativity basically because it doesn't 'cause' anything. The image of the turtle is a physical object that is caused by an event very different from a real turtle.

So the 'group velocity' is really a sort of 'image velocity'. You could consider an optical image a group of photons. The group can travel faster than the photons when the photons are not causally connected.

Special relativity runs into 'paradoxes' only when the object traveling faster than the speed of light can also carry messages. If the object moves faster than the speed of light (c) an can't carry messages, it is basically just an image. There is no restriction on how fast an image can go.


I am not claiming that the research was useless. The scientists involved probably discovered something useful. Group velocity is an important concept. For example, they may be able to encode messages using this faster group velocity. They may be able to make more powerful computers using this group velocity. The concept of group velocity is very important even when it doesn't describe the sending of messages. However, they did not prove anything concerning 'relativity' one way or another.

 

[wogoga]

20 August 2015 wogoga: Show that Einstein's resolution of the twin paradox is wrong.
Start with citing his paper that you should have read.

Thank you for the hint.

The article Dialog about Objections against the Theory of Relativity, 1918 is quite revealing and shows that poor Einstein really had to struggle with the many serious objections against Relativity. The Critic of the dialog at least somehow represents also Einstein's own "reservations about the theory" and insecurity. For instance (first paragraph):

"We have no wish to dwell on whether this neglect [to deal with objections] was due to arrogance, or a sense of weakness, or laziness - maybe it was a particularly effective mixture of these afflictions of the soul".​

Interestingly, Einstein also uses his Critic to criticize other critics (second paragraph):

"I am not so full with the status of my guild so as to make me act as a superior being with superhuman insight and certainty (…). On the contrary, I talk as a human being, since I am aware that it is not rare for criticism to originate from lack of own thoughts."​

I've compiled a short text with the essence of Einstein's resolution of the twin paradox, Essence of Einstein's Resolution of the Twin Paradox, using only extracts from his original (translated) text.

Here I deal with the last paragraph of this compilation. At first, I quote Einstein, and then, I show the implications for my treatment of Langevin's twin paradox in #43 and #56.

Einstein: "According to both descriptions the clock U2 is running a certain amount behind clock U1 at the end of the observed process."​

Implication: When both clocks meet again, travelling T-clock is behind R-clock, because only 2.0001 year have passed in T-clock whereas 200.01 year have passed in R-clock.

Einstein: "When relating to the coordinate system K' the behavior explains itself as follows: During the partial processes 2 and 4 [inertial motion] the clock U1, going at a velocity v, runs indeed at a slower pace than the [in K'] resting clock U2."​

Implication: With respect to T-clock, R-clock runs indeed slower according to Lorentz-factor 100 during inertial motion of both forward and return trip of the journey. This results in 0.020001 year in R-clock versus 2.0001 year in T-clock.

Einstein: "However, this is more than compensated by a faster pace of U1 during partial process 3."

Process 3: "A homogenous gravitational field appears, that is directed towards the positive x-axis. Clock U1 is accelerated in the direction of the positive x-axis until it has reached the velocity v, then the gravitational field disappears again."​

Implication: During direction reversal, R-clock runs faster by 199.99 year. In this way, the time delay of 2.0001 - 0.020001 = 1.98 year of T-clock with respect to R-clock during inertial motion is transformed for the whole journey into a time delay of 200.01 - 2.0001 = 198.01 year of R-clock with respect to T-clock (implying a two-time change by factor 100).

I'm genuinely flabbergasted by Einstein's continuation:

"According to the general theory of relativity, a clock will go faster the higher [weaker] the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher [weaker] gravitational potential than U1."​

I had to read this several times on different days before noticing and becoming (almost) certain that already this statement stems from confusion and wishful thinking. Einstein must have confused "higher gravitational potential" with "stronger gravitational potential" or "[in K'] resting clock U2" with "clock at rest U1". If clock U1 is accelerated by a gravitational field, then U1 is located at a lower (stronger) gravitational field. And this makes clock U1 running slower, and not faster as it would be necessary to resolve the paradox.

"The calculation shows that this speeding ahead constitutes exactly twice as much as the lagging behind during the partial processes 2 and 4."​

Even if instead of gravitational time dilation we had its opposite, gravitational time contraction, this statement still would be untenable, and Einstein should have written:

Under the premise that Relativity Theory is consistent, a calculation must show that this speeding ahead of clock U1 constitutes on a logarithmic scale exactly twice as much as the clock's lagging behind during the partial processes 2 and 4.​

I know from personal experience that all too willingly one accepts the result of a superficial calculation or reasoning, if it agrees with one's expectation, for whatever reason.

In any case, even if I do not agree with every detail of On Einstein’s resolution of the twin clock paradox, C. S. Unnikrishnan, 2005, I have to subscribe to Unnikrishnan's conclusion:

"It is concluded that Einstein’s resolution using gravitational time dilation suffers from logical and physical flaws, and gives incorrect answers in a general setting."​

Cheers, Wolfgang

 

[Reality Check]

Thank you for the hint.

I snipped some irrelevant text.
Dialog about Objections against the Theory of Relativity, 1918

I'm genuinely flabbergasted by Einstein's continuation:

I am also genuinely flabbergasted , wogoga.
"According to the general theory of relativity, a clock will go faster the higher [weaker] the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher [weaker] gravitational potential than U1." is easily understood.
U2 (the travelling twin) is not on Earth. U2 is at a higher altitude (further from the Earth) than U1. That gravitational potential is "higher" and thus U2 is in a weaker gravitational potential than U1. There will be gravitational time dilation between U2 and U1.

Imagining that a "gravitational time contraction" exists does not refute Einstein's argument. So try again.

20 August 2015 wogoga: Show that Einstein's resolution of the twin paradox is wrong.

Citing a fairly obscure research article does not change physics that has withstood the test of time (almost a century). The author presents opinions about thought experiments that are not in Einstein's paper!

Cheers Reality Check

 

[fuelair]

Insofar as your comment represents modern "science", it shows that "science" essentially is based on faith (in authoritative orthodoxy).





In my opinion, you try to rescue Special Relativity by confusing world-map with world-picture. Quotes from Essential Relativity, Wolfgang Rindler, 1977, World-picture and world-map:

"In relativity it is especially important to distinguish between the set of events that an observer sees at one instant and the set of events that the observer considers to have occurred at that instant. What an observer actually sees or can photograph at one instant is called a world-picture. It is a composite of events that occurred progressively earlier as they occurred farther away. For our present purposes it is irrelevant."

"The concept that plays a pervasive role in special relativity is that of the world-map. As the name implies, this may be thought of as a (3-dimensional) map of events, namely those constituting an observer’s instantaneous 3-space t = t₀. It could be produced by having auxiliary observers at the coordinate lattice-points all map their immediate neighborhoods at a pre-determined time t = t₀, and then joining all these local maps into a single global map."

"The world-map is generally what matters."​

Your first point is correct:

• For the travelling clock, the clock at rest is running slower during any inertial movements.
  This is standard SR.

Your second point however, despite seemingly being a common-sense conclusion from the first point, is wrong:

• The clock at rest after the whole round trip reads less than the travelling clock.
  This is the twin paradox - the at home twin is younger than the travelling twin!

Correct within "standard SR" is the exact opposite:

• The clock at rest after the whole round trip reads more than the travelling clock.
  This is the twin paradox - the at home twin is older than the travelling twin!

Actually your error is a salient incarnation of the Lorentz-factor confusion I mentioned at the end of post #56.

Cheers, Wolfgang

Although you seem fraught with lack of knowledge in this area, I must ask if you are aware that a number of interesting things and procedures developed over the last 40 + years would not function correctly (as they do) were Einstein's stuff wrong.

 

[fuelair]

PS: Science is based on people called scientists who actually know what we call sciences and know how it is done and for lots of it (in Physics particularly - and it's branches) by application of what is known to what is desired to be known and verifications from real experiments and real math and real checking and verifying by other real scientists who stand to gain fame and possibly fortune if they can prove it is wrong!!! Also, we have other really bright people called technologists who work very hard in related ways to apply the scientific discoveries to real material products/devices/new chemicals (etc. it's a long list) for our benefits. If you can't use it in technology, then it might not be considered so important - but, then, tech keeps right on improving all the time. This is why I cannot bring myself to give you the time of day anymore.

Have an interesting life!!!

 

[wogoga]

I'm genuinely flabbergasted by Einstein's continuation:

"According to the general theory of relativity, a clock will go faster the higher [weaker] the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher [weaker] gravitational potential than U1."​

I had to read this several times on different days before noticing and becoming (almost) certain that already this statement stems from confusion and wishful thinking.

"According to the general theory of relativity, a clock will go faster the higher [weaker] the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher [weaker] gravitational potential than U1." is easily understood.

I had no intention to dispute the simplicity and correctness of this statement. However, this statement does not support the proposition "U1 running faster" in support of which it has been introduced. "U2 located at a higher [weaker] gravitational potential than U1" means: "U2 running faster". Thus Einstein uses "U2 running faster" in order to support a necessary premise for his resolution of the twin paradox, namely the premise "U1 running faster than U2".

I explain such a catastrophic mistake by confusion based on the belief in the validity of Relativity Theory. Yet in this case, I can even understand those who assume that Einstein used con tricks.

Once again Langevin's twin paradox with Lorentz-factor 100 and travel-distance 2 x 100 LY, with respect to the travelling clock U2:

. . . . . . . . . Travelling clock U2 . .Resting U1
. . Inertial motion . . . 2.0001 year . . 0.02 year
. . Direction reversal. . . . .0 year . 199.99 year
. . Total time. . . . . . 2.0001 year . 200.01 year

In this limit case of negligible acceleration time, direction reversal must add 199.99 year to clock U1 while clock U2 remains unchanged. And Einstein explains this "speeding ahead" of clock U1 by 199.99 year with gravitational time dilation of U1!

Cheers, Wolfgang

 

[Belz...]

This is incorrect because the speed of light is the same in all reference frames. You added the velocities linearly. However, you should have used the formula for relativistic addition of velocities.

Bwa ha ha ha! Isn't that the central principle of relativity? You'd think the OP would know that.

 

[RussDill]

. . . . . . . . . Travelling clock U2 . .Resting U1
. . Inertial motion . . . 2.0001 year . . 0.02 year
. . Direction reversal. . . . .0 year . 199.99 year
. . Total time. . . . . . 2.0001 year . 200.01 year

In this limit case of negligible acceleration time, direction reversal must add 199.99 year to clock U1 while clock U2 remains unchanged. And Einstein explains this "speeding ahead" of clock U1 by 199.99 year with gravitational time dilation of U1!

Cheers, Wolfgang

You've put a table where events separated by space are happening simultaneously and made comparisons between them. Such comparisons would be different depending on which inertial frame of reference you choose, making your table meaningless.

 

[Reality Check]

I had no intention to dispute the simplicity and correctness of this statement. However, this statement does not support the proposition ...

Text in various colors do not change the physics, wogoga: Gravitational time dilation.

Fantasies about invalidating "Relativity Theory" do not change the physics, wogoga: Gravitational time dilation.

People insulting Einstein does not change the physics, wogoga: Gravitational time dilation.

Once again: Langevin's twin paradox has been resolved by people who applied vaild "Relativity Theory", wogoga.

A table of numbers in various colors does not change the physics: Twin paradox
You have a "limit case" of infinite acceleration - it takes infinite acceleration to reverse velocity on no time. That would be infinite gravitational time dilation! That is why it does not appear in Einstein's essay.

Argument by incredibility ("wow that is a big number"" but then so is the speed of light 299,792,458 m/s and it exists!) does not change the physics: Twin paradox

Dialog about Objections against the Theory of Relativity solves the general case not the specific example you are incredulous about.

It should be kept in mind that in the left and in the right section exactly the same proceedings are described, it is just that the description on the left relates to the coordinate system K, the description on the right relates to the coordinate system K'. According to both descriptions the clock U2 is running a certain amount behind clock U1 at the end of the observed process. When relating to the coordinate system K' the behaviour explains itself as follows: During the partial processes 2 and 4 the clock U1, going at a velocity v, runs indeed at a slower pace than the resting clock U2. However, this is more than compensated by a faster pace of U1 during partial process 3. According to the general theory of relativity, a clock will go faster the higher the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher gravitational potential than U1. The calculation shows that this speeding ahead constitutes exactly twice as much as the lagging behind during the partial processes 2 and 4. This consideration completely clears up the paradox that you brought up.

The calculation is not included but this is an essay, not a scientific paper.

If you were to attempt to create a table that was valid, wogoga. then it would reflect the diagram in that essay, i.e. there would be 5 rows for each of the steps in Langevin's twin paradox. You would then do the calculation that are left out of the essay and come up with the same conclusion - the paradox is resolved.

 

[ben m]

Wogoga, please look up a book or an online lecture on special relativity.

Read the whole thing until you get to an explanation of the Lorentz transformation. It will look like two equations telling you how to find a transformed time-coordinate (sometimes called t') and a transformed space-coordinate (sometimes called x'). The equation tells you where to plug in BOTH x and t to find t', and where to plug in BOTH x and t to find x'. That's what Special Relativity is---it's what Einstein explained, it's what modern physicists teach and use and test.

You are doing *something* to a time coordinate t, but you are not using Special Relativity to do it. What you are doing instead is nonsense and wrong. The fact that your results are wrong is your fault, not Einstein's fault or physicists' fault.

 

[wogoga]

You are doing *something* to a time coordinate t, but you are not using Special Relativity to do it. What you are doing instead is nonsense and wrong.

Please state one concrete example of what you consider wrong. Then I will explain why you are wrong in thinking that I am wrong.

With the premises

• U1 = resting clock or twin; U2 = travelling clock or twin
• travel speed v (with Lorentz factor 100) in direction of x-coordinate
• negligibly small acceleration times (or "synchronization of clocks during inertial encounter")
• implicit use of year and LY

the Lorentz transformation for the outward trip of Langevin's twin paradox results in:

[1] x' = 100 x – 99.995 t . . [3] x = 100 x' + 99.995 t'
[2] t' = 100 t – 99.995 x . . [4] t = 100 t' + 99.995 x'

The only reasonable way to link two inertial frames F and F' is to use the event {x=0, t=0} because it transforms to event {x'=0, t'=0}. The choice of e.g. event {x=0, t = 2015 year} would transform by [1] and [2] to {-201490 LY, 201500 year} of F'. (Therefore I normally prefer to use the Lorentz transformation with coordinate-differences, e.g. for dealing with Bell's spaceship paradox).

In frame F, the event of U2 reaching the target 100 LY away, is {100 LY, 100.005 year}. This transforms to {0 LY, 1.00005 year} of F'. This result is obvious, as in F' U2 remains at x' = 0, and 1.00005 year proper time are needed to reach the reversal point.

At t' = 1.00005 year, just before changing direction (or synchronization with a clock moving in opposite direction), U1 is 1 LY (=100 LY / 100) away from U2 (in direction of the negative x'-axis). This means, U2 attributes x' = -1 LY to U1. If we transform this F'-event {-1 LY, 1.00005 year}, we get the F-event {0, 0.01 year}.

Thus, also the use of the Lorentz transformation demonstrates that in F only 0.01 year have passed, whereas 1.00005 year have passed in F'. This result agrees with both Einstein and me. So instead of the table of post #70 we get this more detailed table:

. . . . . . . . . Travelling clock U2 . .Resting U1
. . Inertial Motion 1 . .1.00005 year . . 0.01 year
. . Direction reversal. . . . .0 year . 199.99 year
. . Inertial Motion 2 . .1.00005 year . . 0.01 year
. . Total time. . . . . . 2.0001 year . 200.01 year

Cheers, Wolfgang

Also a false premise (Lorentz transformation) can lead to a correct conclusion (time dilation according to Lorentz factor)

 

[Darwin123]

Please state one concrete example of what you consider wrong. Then I will explain why you are wrong in thinking that I am wrong.
...
With the premises
...
[*]negligibly small acceleration times (or "synchronization of clocks during inertial encounter")
...

Okay, this is wrong. The acceleration can't be negligible if it reverses the direction of the space ships motion as seen from the earth.

It the acceleration is small, then it has to act over a long time span in the rocket ship frame in order to bring the space ship back home.

If the span of time is short, then the acceleration has to be huge to bring it back home. However, a large acceleration can't be negligible.

The acceleration can' be negligible in any round trip. The act of accelerating and decelerating the rocket ship makes the acceleration with all effects significant.

The force that makes the rocket ship change direction also breaks the symmetry of the argument. When you said the acceleration was negligible, what you really meant was the force on the space ship is negligible. However, the force can't be negligible.

Every time you say that the acceleration is negligible, you are making a mistake! It is impossible for the acceleration to be negligible in a round trip!

Your challenge is a bluff. Many people have pointed out that the two rockets are in different inertial frames. I have mentioned the role of force many, many times. You have been reminded of the difference between an inertial and noninertial frame more than a hundred times.

You have NEVER addressed these claims. Not even an acknowledgement that the claims were made. You ignore people who bring up the correct answers! You accuse people of not answering you! More than a hundred times!

I predict that you will ignore my statement or try to change the subject! You will repeatedly ignore responses describing non-inertial frames for at least a hundred more posts! Maybe four thousand more posts!

However, congratulations for maintaining a thread for more than four thousand posts without once responding directly to the rebuttals that have been addressed.

I mean, four thousand posts! No coherent response from you! People are still addressing you as though you are rational!


Four thousand threads. Only twenty five participants! Maybe fifty responses per participant! Maybe one hundred correct responses! Not even one acknowledgement!

I nominate Wogoga for Relatively Light Weight Paradoxist! Or something!

 

[Reality Check]

Please state one concrete example of what you consider wrong. ...

"negligibly small acceleration times" is vague nonsense - any acceleration time can be considered to be "negligibly small" in the right context.

But what you really have is massive accelerations that cannot be ignored . These are the accelerations that Dialog about Objections against the Theory of Relativity considers and finds a resolution to the twin paradox in gravitational time dilation.

That the Lorentz transformation is a "false premise" reveals an abysmal ignorance of SR, wogoga, since the Lorentz transformation is not a premise !
The Lorentz transformation is a derivation of SR from its postulates that is backed up by overwhelming empirical evidence.

 

[Darwin123]

As long as you do not understand the simple reasoning shown in post #33, you cannot judge #43.

And what do you consider wrong with my treatment of Langevin's twin paradox (Lorentz-factor 100; one-way travel distance of 100 LY)?

Here is where you are wrong. You used an incorrect formula for time dilation. The formula that you used for time dilation is only true when the acceleration is negligible. Clearly, the acceleration is not negligible when there is a round trip.

The general solution is not accessible without calculus. However, you asked for a concrete example of how you are wrong. I think you meant 'specific' when you said concrete.


Therefore, I will present a specific case where the acceleration may be very small. The acceleration is considered a constant for the entire round trip. The acceleration may be small but it has to apply over the entire time interval in both frames. I will also ignore the orthogonal directions as you did.

Let us suppose there is a constant force being exerted on the rocket in the reference frame of the rocket. Then,

dt' = (dt) (1-[ax/c^2])/sqrt(1-(v/c)^2)

where

a = F/m.

The glossary is this:

dt': small interval of time measured by the observer in the rocket.
dt: corresponding interval of time measured by observer on earth.

F: Force on rocket
m: mass of rocket

x: distance of rocket from earth.
c: speed of light in a vacuum.
v: relative velocity between rocket and earth.
a: the dynamic acceleration of the observer.

This was derived for a one spatial dimension case where the force on the rocket is constant in time. The F in this case is the thrust of the rocket. The thrust determines the dynamic acceleration, 'a'. However, there is no thrust acting on the observer on earth. There is the asymmetry.

Note that my formula reduces to the traditional 'Lorentz time dilation formula' when F = 0. When F =0, then a = 0. In that case, the rocket can never pass the earth once more. However, the force can't be zero if the rocket passes the earth more than once.

I first got a simple version of it in the book, 'General Relativity' by Wheeler. However, he used both Greek letters and units where c=1. He also didn't really make the role of forces very clear.

Please note that the equation is not symmetrical because of the dynamic part. You can reverse the position of the observers but you can't reverse the force acting on the rocket ship.

Obviously, Wogoga wrong in the case of a rocket undergoing a constant acceleration in its own reference frame. If 'F' is not '0', then the rocket man will experience a 'speed up' of the earth bound clock at some value of 'x'. His calculation did not include the acceleration, 'a'. Instead, he stated with no justification that the 'acceleration is negligible'.

I found the formula easy to derive from the Lorentz transform and the definition of force common to both Newtonian physics and special relativity. It just took a little calculus. Perhaps you can show how I am wrong without calculus using your incredible insight.

There will be some relativity purists who would sniff that I used the concept of 'relativistic mass' which is generally frowned upon in the modern physics community. To them I say, 'Pooh'. The formula that I gave can be derived using calculus. It really doesn't matter that the mass 'm' is a tensor since I am using a one-dimensional approximation. Anyway, back to Wogoga's challenge.

You challenged us to give one concrete example of where you are wrong. You then said that you would show the poster why you were not wrong.

So here is the concrete case. I gave you a formula for the time dilation/expansion in the case of a rocket being acted on by a force constant in both magnitude and direction. The formula obviously allows for a speed up of the earth clock.

I have not insulted Wogoga in any way. I have not used any ad hominem argument. I have merely stated what the correct formula is for the case of a rocket being acted on by a constant force.


If anyone who knows relativity can see where my formula is wrong, then let his say so. Please help Wogoga out.

I gave Wogoga a very concrete reason why he is wrong. He is not using an appropriate formula. I gave him one appropriate formula, consistent with a rocket engine that is constantly running. I have shown how in this instance the acceleration has a significant affect.

Wogoga did not use the full Lorentz transformation. It is possible to handle the case of an instantaneous impulse using the full Lorentz transformation. I can also do the case for an instantaneous impulse that reverses the direction of the rocket. However, it is obvious to everybody else that the acceleration can not be negligible in this case. It is going to be huge. By restricting the force to be small but constant, I am making it simple for Wogoga. He should be able to tell me where I am wrong.

If Wogoga doesn't try to tell me why I am wrong, or changes the subject, then he was just bluffing. If he is able to tell me how my formula is inconsistent with special relativity, then he will have proven his point.

I don't think that I will get back to this thread until he addresses me one way or another. This is not an insult. I am respecting his sincerity. He said that he would answer any concrete objection to his argument. I am sure that he will follow through on his challenge.

Cheers, Wogoga!!!

 

[wogoga]

Please state one concrete example of what you consider wrong. Then I will explain why you are wrong in thinking that I am wrong.

With the premises

• ...
• negligibly small acceleration times (or "synchronization of clocks during inertial encounter")

Okay, this is wrong. The acceleration can't be negligible if it reverses the direction of the space ships motion as seen from the earth.

It the acceleration is small, then it has to act over a long time span in the rocket ship frame in order to bring the space ship back home.

If the span of time is short, then the acceleration has to be huge to bring it back home. However, a large acceleration can't be negligible.

I must admit that what you write here seemed at first completely misguided to me, because it is possible to make the acceleration period of direction-reversal arbitrarily short in comparison with the two periods of inertial motion, by increasing the distance from resting U1 to the reversal point of travelling U2. Therefore the effect of time contraction due to acceleration can be made negligibly small compared to the effect of time dilation due to inertial motion.

Yet from Wheeler's formula of your post #78 I had to learn that my above conclusion is based on a premise, namely that time contraction due to acceleration is independent of the location where it takes place. In any case, I'll comment on Wheeler's formula.

We also have the possibility of inertial encounter mentioned by Unnikrishnan. In our case, this means that at reversal-point 100 LY away, clock U2 (v = +0.99995c) synchronizes with an identical U2 moving in opposite direction (v = -0.99995c). In this way, acceleration of U2 is fully kept out of the game.

Also a false premise (Lorentz transformation) can lead to a correct conclusion (time dilation according to Lorentz factor)

That the Lorentz transformation is a "false premise" reveals an abysmal ignorance of SR, wogoga, since the Lorentz transformation is not a premise !
The Lorentz transformation is a derivation of SR from its postulates that is backed up by overwhelming empirical evidence.

The conclusion (resp. child) of one reasoning can be a premise (resp. parent) of another reasoning. Thus, insofar as we derive Lorentz-factor mass-energy-increase from the Lorentz transformation, the transformation is the premise, and mass-energy-increase is the conclusion.

Cheers, Wolfgang

Refutation of Special Relativity for Dummies (Time Dilation, Twin Paradox)

 

[Reality Check]

...Therefore the effect of time contraction due to acceleration can be made negligibly small compared to the effect of time dilation due to inertial motion.

Therefore we can see that you have no understanding of what you have cited or comprehension of the text that has been quoted to you, wogoga !
Dialog about Objections against the Theory of Relativity

It should be kept in mind that in the left and in the right section exactly the same proceedings are described, it is just that the description on the left relates to the coordinate system K, the description on the right relates to the coordinate system K'. According to both descriptions the clock U2 is running a certain amount behind clock U1 at the end of the observed process. When relating to the coordinate system K' the behaviour explains itself as follows: During the partial processes 2 and 4 the clock U1, going at a velocity v, runs indeed at a slower pace than the resting clock U2. However, this is more than compensated by a faster pace of U1 during partial process 3. According to the general theory of relativity, a clock will go faster the higher the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher gravitational potential than U1. The calculation shows that this speeding ahead constitutes exactly twice as much as the lagging behind during the partial processes 2 and 4. This consideration completely clears up the paradox that you brought up.

No matter how "negligible" you imagine the acceleration to be, it is always the amount needed to account for the two other processes.