Opinions about Relativity

(First version (in Spanish): January 25^th, 2003
Last modification: October 1^st,  2003.)

In other pages I have carried out some comments in relation with opinions of different thinkers about Relativity. However, in this page I want to do a global summary of those opinions. In this way I hope I am helping to find their own place to people who feel confused with the Relativity vision of the Universe.

Leaving aside politic opinions as those that gave origin to the book "100 Scientists Against Einstein" (seemingly promoted by Hitler, although I never had access to the original book) the Relativity, as scientific and philosophical theory, has generated different reactions (just emotional or rational ones)

Through different readings and exchanges of opinions with professionals involved in Physics and other scientific branches, I have found four main groups of people.

• Group 1. - Those accepting the Relativity, convinced that it is one of the greatest achievements of Common Sense. They deny completely the existence of paradoxes in the theory. Of course, this is the main group of professionals involved with Relativity.
• Group 2. - Those accepting the functionality of the Special Relativity. They use their equations regularly and they don't try to discuss the concepts because they believe that it is a very thorny topic or it was already debated and overcome. And, after all, if the equations work fine, what is the reason to worry if it involves paradoxes or not. It is the pragmatic group. A numerous group, perhaps more numerous than the first one.
• Group 3. - Completely denying the validity of the Theory of Relativity. They try Einstein as one of the biggest humbugs at all times and they say Relativity is plagued by paradoxes. At the end they also deny the validity of Lorentz transformations. It is surprising how many people constitutes this group. Some of them affirm that Einstein stole his ideas from other physics (including his first wife) :-)
• Group 4. - A minority (they are surely more, but I have not identified more than 10 people having this posture) believing in the validity of relativity  equations, but, they don't agree with the interpretation officially made of them.

Almost all members of Group 4 and some of Group 3 believe to deal with an alternative solution. But each one has his own. : - (

As readers arriving to this point must have noticed, my ownership group is the number 4. :-)

But, same than other members of this group, I obtained this location after convincing myself, with a lot of effort, that I cannot be part of Group 1.

My experience when dialoguing with people from other Groups is the following:

• With members of Group 3 I am not able to dialogue. It happens to me the same as when I have tried to dialogue with astrologists, futurologist or ufologist. It  doesn't exist a common base to dialog with them.
• Members of Group 2, by definition, don't discuss about foundations or concepts.
• With members of Group 1 I have maintained long and constructive (at least for me) chats. However never (NEVER), any of the parts was able to convince the other one. I know cases where these discussions (developed at Internet forums) have finished with reciprocal insults. It is not my case. I cannot get angry with somebody that believes things rationally different to those that I believe. We only think different and we use different models to describe reality.

Examples 

To understand the type of incompatible ideas between Group 1 and Group 4 people, it is valid to use a classic example historically related with Relativity.

The immobility of The Earth

In times of Galileo it was supposed that existed an irrefutable prove of the immobility of The Earth: "The stones falling from the high of a tower follow a perfectly vertical fall until the foot of the tower".

Now we know The Earth is not immobile and the journey of the stone has to do with the law of inertia, but let us analyze this example with some detail, using supposed observers with different models (paradigms):

• Observer A is Aristotelian. He believes that for an object to remain in movement it is necessary to apply permanently an impulse. The cars thrown by a horse are an ideal example of this phenomenon.
• Observer B believes in the law of Inertia: All object non-subjected to external actions maintains its state of rest or uniform movement.
• The two observers accept that the stone falls following a perfectly vertical way (in fact there are effects of second order but they are irrelevant for this example)
• Observer A considers that this result can only be explained if The Earth is immobile. In other case, when the stone abandons the hand, it stops to receive its impulse and therefore should be delayed in relation with the terrestrial movement. Remember that points located in the Equator are traveling (as consequence of the terrestrial rotation) about 40,000 Km per day, (almost 460 meters per second).
• For observer B the result demonstrates anything at all because the law of inertia is effective even if the tower was in movement or if it was at rest. And in both cases the stone should fall directly to the foot of the tower.

Believe me that only if some of the observers change their paradigm (permanent impulse or law of inertia) it is impossible that they come to an agreement. And also believe me that the change of paradigms is a very difficult task for an individual formed in a certain "school of thinking".

And, as an example of a typical discussion between Group 1 and Group 4, I could (I should!) mention the famous Twins Paradox.

Typical discussion on the Twins Paradox

Observer OG1 (Observer from Group 1) as well as  observer OG4 (Observer from Group 4) agree with the issue that the Twin in motion returns younger than the Twin that remained stationary. However, as the stone and tower example, the interpretation of both observers is completely different.

To be more specific I will reduce the example to the minimum expression and then I will simulate the typical subsequent discussion:

Very simple Twins Paradox example:

• Let us assume we have got an inertial system quite long to carry out all experiences we believe necessary.
• The two Twins (Twin A and Twin B) are separated by a considerable distance.
• Both Twins synchronize their clocks using the method proposed by Einstein. So they are happy with the initial reading of their clocks as well as with their rhythm of march.
• At a certain instant (after previous agreement of both Twins), Twin B leaves his home to visit Twin A. Twin B makes his trip at a great "relativistic" speed.
• To allow for easy calculations, we choose 259,808 Km/s that lead to a coefficient of Lorentz equal to 0.5
• According to measurements made by stationary observers (at rest in the initially mentioned axis), the accelerated period consumes a complete day (86,400 s).
• From that instant Twin B travel (inertially) at 259,808 Km/s toward Twin A position.
• Also to simplify the example, let us say that the trip consumes 20 years of the time measured by Twin A and for all the observers that remained in the stationary axis.
• During the whole trip Twin A observes that Twin B clocks go halfway its own rhythm, producing a 10 year-old accumulation in the age of Twin B.
• Twin B also observes that Twin A clocks go halfway its own rhythm along the entire itinerary.
• In the crossing instant both Twins take out a photo of themselves, where Twin A and Twin B appear in the same picture. This observation is simultaneous because there is not appreciable difference in space. Both twins are simultaneously in the same place.
• Twin B doesn't stop its trip, but both have the picture taken in the crossing moment.
• Both Twins coincide that Twin A is 10 years older than Twin B in the crossing instant.

Until here I am using a simple variation of the well known Twins Paradox as usually exposed in Special Relativity. Indeed I simplified the example in order to minimize the number of accelerations made by Twin B.

Then , let us see a typical discussion between OG1 and OG4 in relation with this "experiment " between the Twins.

The crucial experimental fact is that Twin A and Twin B agree in their appreciations: Twin A is 10 years older than Twin B in the crossing instant. OG1 and OG4 reach an agreement at this point. This is an irrefutable experimental result (as the falling stone was).

After reaching this point, let us begin a typical dialogue:

OG4 - (Warming engines) There are not reasons to suppose that the rhythm of Twin A clocks has suffered alterations in the entire period.

OG1 - I agree. Twin A remained in an inertial axis while the whole experience.

OG4 - In that case, the experimental result demonstrates that Twin B clocks suffered a REAL alteration during the itinerary.

OG1 - (Usually with reluctance, because Special Relativity affirms that the alteration of clocks is only apparent and depend on the observer) Mm!.... yes, it should be in this way. Although it is necessary to think that Twin B was subjected to accelerations and therefore to describe its behavior it is necessary to employ the General Relativity Theory (GR)

OG4 - Although I don't believe that General Relativity solves the problem, I agree; Twin B has suffered more shakes than its brother. Tell me, then, where do you believe that the REAL alteration of Twin B clocks took place? During the inertial flight or during the period of acceleration?

OG1 - (Once again with reticence to give a categorical answer) Could be the consequence of a combination of both periods.

OG4 - Let me, then, to be more explicit in the question: Do You believe that during the 20 years of inertial flight (time measured by Twin A and all the observers at rest in the stationary axis) the Twin B clocks REALLY go at less speed than those of Twin A?

OG1 - (avoiding a direct answer to the question) Everything depends on the reference system that you choose. From the point of view of Twin A, Twin B clocks go more slowly. But for Twin B, Twin A clocks have the lazy behavior.

OG4 - But... we were in agreement that, when twins meet, both twins agree that Twin B is younger than Twin A. And because Twin A was languidly in inertial rest, we can only conclude that Twin B suffer a  REAL alteration of the rhythm of his clocks in some moment. Could you give an alternative to explain the experimental result?

OG1 - First, and more common, alternative: As they see the upcoming consequences, many OG1s answer, in this point, something like: "What happens is that you want to analyze the Twins Paradox using Special Relativity and it is impossible. You should study General Relativity to solve this problem!". In this way they finish abruptly the discussion and hide under the carpet the paradoxes of Special Relativity. At this point is worthless to remember that particles accelerators agree with Special Relativity or that Einstein used Special relativity to develop the first version of the Twins Paradox in 1905, concluding that the traveling Twin suffers a REAL alteration in his clock.

OG1 - Second alternative (is used by who believes firmly that GENERAL RELATIVITY solves the Twins Paradox): In that case we can accept momentarily that the change took place during the acceleration period. But I remind you that this calculation is beyond Special Relativity possibilities.

OG4 - (Distrusting because the easy way things are coming) Well, allow me to be sure we are speaking the same thing. Let me know if the points we agree on are the following:

• We are saying the trip of Twin B begins, for example, when both twins are 30 years old.
• Twin B invests one day in the acceleration until he reaches the final speed. Twin A measure this time (we don't know what time Twin B clock reads because he is at a non-inertial system)
• Trip takes 20 years for Twin B. Always according to the registration of Twin A.
• During the whole trip both Twins agree that the other Twin clock are going slower.
• In the crossing instant Twin A is 50 years old. The 30 initial years plus the 20 languid ones he was waiting for his brother arrival.
• In the same moment and place (when they see each other "face to face") Twin B is 40 years old (The coefficient of Lorentz is 0.5) The 30 initial years plus the 10 ones he aged during the 20 year trip (according to Twin A readings)
• Consequences:

  1.- Twin A observation is completely coincident with the result of the experience (like in accelerators of particles, where the stationary observer could describe the half-life, the mass and other properties of fast particles)

  2.- In some period the Twin B clocks REALLY slow down 10 years.

OG1 - You insist the alteration is REAL but I insist everything depends of the observer (with "nails and teeth" tied to the inertial systems equivalence)

OG4 - I Insist the alteration is REAL, because it is the only way I can explain, being both twins together (one beside the other) that Twin B is younger than Twin A. If, just as it can be made in an accelerator of particles, we divide a population of certain half-life isotopes and, then, we accelerate one group to relativistic speeds. At the end of the experiment we find that less particles in the accelerated group than in the other group have been disintegrated. We should conclude that disintegration was REALLY slower in the accelerated group. Or, there exists another possibility?

OG1 - Well. Only momentarily accepted. Lets go with the analysis

OG4 - Then, if we accept that the slowness of Twin B clocks is only apparent during the inertial flight, we are forced to conclude that Twin B REALLY lost 10 years during the acceleration.

OG1 - One moment. You conclude things too quickly.

OG4 - Well, give me another possible conclusion.

OG1 - Sorry, by the moment I can't give an alternative. But don't forget, we have not considered the results of General Relativity (insisting with the General Relativity "magic" solutions.)

OG4 - OK, I repeat: We are forced to conclude (until a new alternative appears) that Twin B clocks slow down 10 years during the acceleration period. But... the acceleration only last one day (measured by Twin A and all the inertial observers). How it is possible in one day, the clock slow down 10 years?

OG1 - (Without realizing the magnitude of OG4 words) Surely, if you check with General Relativity you will see it is possible.

OG4 - Although I find it absurd, I propose that instead of checking with General Relativity we can go a step further and accept that General Relativity  is able to generate that result. Then, we are in agreement that  during the acceleration, Twin B clocks REALLY slow down 10 years.

OG1 - (Breathing normally) Well, in this case, it is demonstrated that General Relativity solves the Twins Paradox.

OG4 - Not exactly. Let us see where are we going with the magic solution of General Relativity. Let us change the experiment and let us suppose that just after the acceleration Twin B discovers he forgot something he wanted to give to its brother. Then, Twin B begins a one-day stopping (once again the time is measured by Twin A which is able to do this because Special Relativity accepts measurements made by inertial observers). Question: What happen during the stopping period with Twin B clocks?

OG1 - I don't understand the question.

OG4 - I will try to explain better the situation. If during the one-day acceleration, Twin B clocks REALLY slow down 10 years, what happen with these same clocks during the one-day brake?

OG1 - It would be necessary to use again General Relativity!!.

OG4 - It is granted. But I allow you to choose the answer. Doesn't matter which, but some result will surely be obtained. :-)

• Possibility 1. - Because, during the acceleration, Twin B observed that Twin A clocks went quicker, it can be assumed that during the braking period he could have observed the same thing. In this way Twin B clock should slow down other 10 years at the end of the operation.
• Possibility 2. - Just because, during the acceleration, Twin B observed that Twin A clocks went quicker, during the brake he could have observed that Twin A clocks went slower (in fact, clocks suffering acceleration go slower than the inertial ones, but.... we open the possibility)

OG1 - Why do you offer only two options?

OG4 - They are two extreme cases. You can choose any answer. You could check that conclusion doesn't depend on the result obtained with General Relativity.

OG1 - Well, although it is not definitive, let us see what happens with option 1.

OG4 - It means Twin B is REALLY younger 20 years than Twin A at the end of the process of acceleration and brake?

OG1 - (Distrusting) Could be.

OG4 - But this result is untenable. During the acceleration and brake only elapsed two days for Twin A who continues being 30 years old (+ two days). For Twin B REALLY been 20 years younger, he should be only 10 years old when concluding the process which began at 30. That is the source of youth..., we found it!!. :-)

OG1 - Then, should be valid the Possibility 2. That's it! During the braking period, Twin B recovers the 10 years he had lost during the acceleration.

OG4 -!!!!?? Are you affirming Twin B REALLY ages 10 years during the one-day brake? Should I remember that General Relativity demonstrates that quick clocks (or subjected to gravitational fields) go slower than the inertial ones?

The following is pure fantasy because the conversation never extends beyond this point. Just simulation:.... :-)

OG1 - And what other alternative exists?

OG4 - Finally you ask about!

The answer is very simple, but to accept it you should have yourself convinced that the Special Relativity leads, INEVITABLY, to paradoxes. If you still believe that it is only a meaningless game, it is worthless to try to generate a rational alternative to Special Relativity paradoxes.

And you should also convince yourself that a theory that generates true paradoxes (NOT apparent paradoxes) has some logical flaw.

Although the answer is entire developed in other parts of this page, at this point I finish the development, to include the comments that you could send to me at [email protected]

And in that way I will be able to fulfill the objective of this page of including the opinion of different people about  Relativity. In each case I will request you that together with the comment you believe pertinent, include the electronic mail and the group of ownership with which you are identified (Group 1, 2, 3, 4 or....).

Special notice:

1. Of course the sequence of questions and answers (and the comments to the margin) are tendentious. I am partial favoring of OG4. : -)
2. The dialogue could take alternative countless ways. But all lead to the same result. For example, when OG1 accepts (with reticence) that the 10 year-old backwardness is REAL and it takes place in one-day measurement in the stationary axis, this result is untenable. If Twin A was at double distance, the REAL backwardness should be 20 years, in the same physical process. And if Twin A was at the end of the period of acceleration, the REAL backwardness should be almost null. It is untenable that a REAL backwardness depends of where I locate the other observer. Also we must wonder what happens if I have several Twins at different distances: How can Twin B be able to suffer different age alterations, all REAL, simultaneously?

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