Relativity Question

[J.C.MacSwell]

For any particle, its own frame is all that matters. There is no "staying in tune" with anything else.

 

 

That's a nonsensical statement. When switching frames one speaks of invariants (conserved is within a single frame only) and time is most certainly not an invariant.

 

The idea that things will "even out" is philosophy, not science.

 

I don't understand this statement, even if it's "own frame" is it's rest frame. I assume I am missing the context.

 

When switching frames anything not invariant is still mathematically dependent. I assumed that was what Tar meant by "staying in tune" (I could be wrong but I hope he did not mean that no time dilation was possible)

Edited July 22, 2011 by J.C.MacSwell

[owl]

Tar and all,

Since we know that clocks slow down at high velocity (usually called time dilation,) can we not assume that other physical processes, like human aging, also slow down?

If that is the case then direction of travel will not matter and the high speed traveler will simply have aged more slowly during the journey out and back. So, depending on how long s/he was gone (in earth years) traveling at high speed and aging slowly, s/he will appear (and be) that much younger on arrival back on earth than his/her twin who that stayed home. Yes?

Edited July 22, 2011 by owl

[Vilas Tamhane]

With respect Vilas - physics without a rigorous mathematical underpinning probably deserves to die, it is mere word salad.

 

BTW in the UK applications to read physics at university are at a high (especially in Manchester and for female students - whether this is due to Manchesters success at modernising curriculum to gain engagement from young women combined with their recent Nobel success OR because they fancy Brian Cox is debatable!)

 

 

Some great scientists have said that truth lies in simplicity. Physics without mathematics is not physics, it is philosophy. I am told that in some universities subject of relativity has been made optional. What does it indicate?

 

QM too is based on hazy concepts and so, on this count, there might be need for advanced mathematics. Once we come to know correct concepts governing a particle in motion, then everything, including mathematics, will become simple.

 

UK example might be an exception. It is important to find out what they did. I am told that in some universities, subject of relativity is optional. What does it indicate?

 

Another reason for the repulsion might be autocratic, arrogant and religious nature of authorities. Everybody likes freedom. Isn’t it astonishing that a journal, ‘American journal of physics’ openly states that they don’t accept papers that go against established theories? This is religion and not science.

 

Institution becomes religion when it has to protect vested interests. These interests are based on race, cast, religion or nationality. It is then ‘what is said’ becomes subordinate to ‘who said it’.

 

Tar and all,

Since we know that clocks slow down at high velocity (usually called time dilation,) can we not assume that other physical processes, like human aging, also slow down?

If that is the case then direction of travel will not matter and the high speed traveler will simply have aged more slowly during the journey out and back. So, depending on how long s/he was gone (in earth years) traveling at high speed and aging slowly, s/he will appear (and be) that much younger on arrival back on earth than his/her twin who that stayed home. Yes?

 

Basic principle in special relativity is completely irrational. It says that time dilation is reciprocal (and so meaningless). To sustain a meaningless theory, meaning was forced into it.

 

If you look at a space-time diagram then you will find that when the twin turns around to return, time on earth suddenly jumps, and so after returning travelling twin will find earthling to have aged more.

 

Even if you don’t like space-time diagram, you can easily calculate time dilation using Lorentz’s equation for time coordinate. At turn around, distance dependent term (vx/c^2) for clock reading of the earthling, suddenly changes sign and by this amount, time on earth ‘jumps’ ahead.

 

But this is all mathematical manipulation. Do you think your watch will suddenly jump when somebody turns around to return?

 

If you don’t wish to question theory, then the answer is that, travelling twin will return younger, not because he was travelling but because, he turned around.

 

If the travel doesn’t involve turnaround, then too, one clock will dilate and not the other depending on the preferred frame. This cannot be explained properly by equations. You will have to tag a frame. If you are comparing time with earth’s frame, then in the space-time diagram, coordinates of this frame will be orthogonal. You can now use invariant quantity, involving space and time, and see that accelerated clock will always run slow.

[md65536]

Some great scientists have said that truth lies in simplicity. Physics without mathematics is not physics, it is philosophy. I am told that in some universities subject of relativity has been made optional. What does it indicate?

 

QM too is based on hazy concepts and so, on this count, there might be need for advanced mathematics. Once we come to know correct concepts governing a particle in motion, then everything, including mathematics, will become simple.

I think Feynman makes a good argument here:

This is from the first of a series of lectures that can be found here: http://www.vega.org.uk/video/subseries/8

If you take his quote out of context you might twist it to support your case.

But what he's saying is that the math isn't sacrosanct. It is just a set of techniques used to arrive at the "final count of beans" of a theory without counting every bean individually. It's not the math that's important but the predictions made by that math, and they're accepted when they best predict the outcome of whatever they model.

The story of the Mayans that he uses is that they were interested in predicting when Venus would show up in the morning vs. the evening, and they figured this out by observing it and counting days, and creating the math for that. This allows them to make accurate predictions. From this, they (we assume) had no idea why Venus followed those predictions, and as Feynman points out, trying to figure it out based only on the observations (the counts of days) is not likely to get you anywhere.

The explanation "it's because Venus and the Earth each orbit the sun with different periods" is nice to know and it's certainly important to us, but it gets you nowhere towards predicting when Venus will show up in the morning or the evening, without complicated math involved (more complicated than the Mayan method).

So beyond what Feynman says, my point is also:

- A new theory doesn't replace an old one just based on explanations, but based on new observations, and on predicting/modeling new phenomena or the same phenomena more accurately.

- New theories do not replace math with logic, but with different math (typically the math doesn't get simpler, I should think).

I do agree that in the future, the explanations for why the math works will become simpler and more satisfying in many cases. As Feynman says several times in that lecture, nobody knows why it works. But that is not how it is judged. Feynman also points out that it's incredibly successful at predicting a large range of phenomena with high precision, and that is why the math is so valued.

[DrRocket]

I think Feynman makes a good argument here:

 

"To summarize , I would use the words of Jeans, who said that ‘the Great Architect seems to be a mathematician’. To those who do not know mathematics it is difficult to get across a real feeling as the beauty, the deepest beauty, of nature. C.P. Snow talked about two cultures. I really think that those two cultures separate people who have and people who have not had this experience of understanding mathematics well enough to appreciate nature once." – Richard P. Feynman in The Character of Physical Law

 

 

[tar]

J.C. MacSwell,

 

Well thankyou for understanding what I meant by what I said. I was trying to figure out how to defend my statement against SwansonT's harse criticism.

 

Yes, I think there is time dilation. Yes I believe relativity is the proper way to look at reality.

 

I was merely investigating what that means to things, in terms of their relative age, and considering the idea that since the universe has shown its ability to keep exact account of itself, there maybe a "conservation of age" type of thing that the universe does.

 

I was sort of drawing an analogy to the other "balancing" things the universe does. That the universe always is balancing the checkbook, at every point, all the time, without error. Take heat for instance, always finding ways to even out.

 

Time dilation in the analogy would be like talking about things being hot or cold. A system would have an average age as a system would have an average temperature. And perhaps in the analogy, the age of the universe is the age of each of its grains added together and divided by the number of grains you are considering.

 

I have not tried out this analogy for but 24hrs or so, so I am not sure whether to consider slow, hot or cold.

That is, if tickers should influence neighboring tickers, would time flow from fast to slow, or slow to fast.

 

For instance, is a particle in an accelerator being "refrigerated" or "cooked"? Would mass be an insulator from, or a conductor of age?

 

Sorry, my analogy, my job to see if there is anyway it could hold.

 

Overall point being that C is the invariant, but space and time are not arbitrary, they are characterisics of the real arrangement of real particles and fields, and each particle and its position has to "fit" the scheme.

 

If A is related to B then B is related to A in the opposite manner. If A ticks faster than B then B ticks slower than A. But the distinction makes no sense unless you consider a time period in which A accumulates more ticks than B. Can't go by A's clock, can't go by B's clock. Have to go by C's. (no pun intended)

 

So let's take a pulsar, 10 thousand light years exactly, from both the sun and Alpha Centuri, that lies on a perpendicular that bisects the path her ship is taking. How many pulses will she count on her trip, compared to the pulses counted by her stay at home twin?

 

Regards, TAR

[Vilas Tamhane]

I think Feynman makes a good argument here:

This is from the first of a series of lectures that can be found here: http://www.vega.org....deo/subseries/8

If you take his quote out of context you might twist it to support your case.

But what he's saying is that the math isn't sacrosanct. It is just a set of techniques used to arrive at the "final count of beans" of a theory without counting every bean individually. It's not the math that's important but the predictions made by that math, and they're accepted when they best predict the outcome of whatever they model.

The story of the Mayans that he uses is that they were interested in predicting when Venus would show up in the morning vs. the evening, and they figured this out by observing it and counting days, and creating the math for that. This allows them to make accurate predictions. From this, they (we assume) had no idea why Venus followed those predictions, and as Feynman points out, trying to figure it out based only on the observations (the counts of days) is not likely to get you anywhere.

The explanation "it's because Venus and the Earth each orbit the sun with different periods" is nice to know and it's certainly important to us, but it gets you nowhere towards predicting when Venus will show up in the morning or the evening, without complicated math involved (more complicated than the Mayan method).

So beyond what Feynman says, my point is also:

- A new theory doesn't replace an old one just based on explanations, but based on new observations, and on predicting/modeling new phenomena or the same phenomena more accurately.

- New theories do not replace math with logic, but with different math (typically the math doesn't get simpler, I should think).

I do agree that in the future, the explanations for why the math works will become simpler and more satisfying in many cases. As Feynman says several times in that lecture, nobody knows why it works. But that is not how it is judged. Feynman also points out that it's incredibly successful at predicting a large range of phenomena with high precision, and that is why the math is so valued.

 

We would have been riding horses in absence of math. No technology can be developed without it. Humans would have still progressed but slowly and insufficiently.

 

I do not agree that one cannot understand physics without math. If this is the case then it is a sure sign of deficiency in conceptual theory. Though I agree that to understand physics in its full grandeur, knowledge of math is necessary.

 

Rather than math, I think we should not hold any theory sacrosanct.

 

 

[DrRocket]

I do not agree that one cannot understand physics without math. If this is the case then it is a sure sign of deficiency in conceptual theory. Though I agree that to understand physics in its full grandeur, knowledge of math is necessary.

 

Rather than math, I think we should not hold any theory sacrosanct.

 

 

 

What you have demonstrated is that you have no idea what mathematics is. Mathematics is not a scientific theory. In fact mathematics, because it has no reliance on experiment and no a priori tie to nature, is not really a science.

 

Mathematics is not symbols. Neither is mathematics primarily equations or even solutions to equations. Mathematics is not only describable in words, it is in fact described in words -- see any good mathematics text. The symbols are merely shorthand for a great many words. Those words are important The use of words in mathematics is exquisitely precise, and you need to know what they mean.

 

"Mathematics is the study of any kind of order that the human mind can recognize" -- Pasquale Porcelli, Professor of Mathematics

 

Mathematics is also the language in which physics is formulated. You can no more understand physics without mathematics than you can understand French literature with no knowledge of the French language. Popularizations and baby talk just don't cut the mustard.

 

If you do not understand mathematics then you are effectively illiterate in physics. Ignorance of mathematics is correctable. Willful ignorance is not.

Edited July 23, 2011 by DrRocket

[swansont]

Rather than math, I think we should not hold any theory sacrosanct.[/i]

And nobody is. Relativity is tested all the time, and it works. The only thing that will falsify it is a series of experimental results showing it to be incorrect. You have not provided any. Not liking or not understanding it is not a substitute for data.

[J.C.MacSwell]

We would have been riding horses in absence of math. No technology can be developed without it. Humans would have still progressed but slowly and insufficiently.

 

I do not agree that one cannot understand physics without math. If this is the case then it is a sure sign of deficiency in conceptual theory. Though I agree that to understand physics in its full grandeur, knowledge of math is necessary.

 

Rather than math, I think we should not hold any theory sacrosanct.

 

Then why do you, like a broken record, continue to base your objections on the same incorrect premises?

 

Where is it that you are asking "what if I am wrong?"

 

You have offered nothing where current theory fails to agree with experiment, and instead cling to ideas that are clearly wrong.

 

What is so sacrosanct about your beliefs that they should hold up despite evidence to the contrary?

[Vilas Tamhane]

What you have demonstrated is that you have no idea what mathematics is. Mathematics is not a scientific theory. In fact mathematics, because it has no reliance on experiment and no a priori tie to nature, is not really a science.

 

Mathematics is not symbols. Neither is mathematics primarily equations or even solutions to equations. Mathematics is not only describable in words, it is in fact described in words -- see any good mathematics text. The symbols are merely shorthand for a great many words. Those words are important The use of words in mathematics is exquisitely precise, and you need to know what they mean.

 

"Mathematics is the study of any kind of order that the human mind can recognize" -- Pasquale Porcelli, Professor of Mathematics

 

Mathematics is also the language in which physics is formulated. You can no more understand physics without mathematics than you can understand French literature with no knowledge of the French language. Popularizations and baby talk just don't cut the mustard.

 

If you do not understand mathematics then you are effectively illiterate in physics. Ignorance of mathematics is correctable. Willful ignorance is not.

 

Mathematics is a tool and to describe in the words of Feynman, to count. You can never describe physics in the language of mathematics. When it is done, it is for the convenience in absence of correct concepts. Physics is how nature works. It is about concepts. Mathematics makes it useful, precise and predictable.

 

Take the example of Maxwell’s wave equations. Maxwell used vector analysis to describe EM fields. When you apply curl operation on a vector field, mathematics cannot convey you nature of that field. Field is assumed. Mathematics cannot decide if it is a field of water velocity or vector field of electric field. Nor can it decide if the application is wrong.

 

Maxwell believed in ether and thought of electromagnetic fields as stresses and strains in ether. Gradient, divergence and curl operations were successfully applied in hydrodynamics. Maxwell visualized that situation is similar and so decided to use this tool in the case of EM fields. He was not only successful but predicted EM waves.

 

But ether is discarded. Now what? Theory of EM waves becomes invalid. But not the equations. If I wish to find out depth of penetration of alternating magnetic field in the steel plate, I use Maxwell’s equations. I am able to make calculations without bothering about the correctness of concepts. I am not ready to abandon Maxwell’s equations even if they are unsustainable with respect to concepts.

 

But physicist is not an engineer. He loves concepts more. Concepts are the heart of any physics theory. At the same time we have to admit that nature is not too liberal in revealing itself. We had to wait for 2000 years before a comparatively simple concept of gravitation became known. Therefore there is no reason for anybody to get disturbed if we do not know many things about nature.

 

Your description of what mathematics is is excellent. I would like to add how Bertrand Russell described it.

 

“Pure mathematics consists entirely of assertions to the effect that if such and such a proposition is true of ‘anything’, then such and such another proposition is true of that thing. It is essential not to discuss whether the first proposition is really true, and not to mention what the anything is, of which it is supposed to be true. Both these points would belong to applied mathematics. We start in pure mathematics, from certain rules of inference, by which we can infer that if one proposition is true, then so is some other proposition. These rules of inference constitute the major part of the principles of formal logic. We then take any hypothesis that seems amusing, and deduce its consequences. If our hypothesis is about ‘anything’, and not about some one or more particular things, then our deductions constitute mathematics. Thus mathematics may be defined as the subject in which we never know what we are talking about, not whether what we are saying is true.”

 

 

[swansont]

But ether is discarded. Now what? Theory of EM waves becomes invalid. But not the equations. If I wish to find out depth of penetration of alternating magnetic field in the steel plate, I use Maxwell’s equations. I am able to make calculations without bothering about the correctness of concepts. I am not ready to abandon Maxwell’s equations even if they are unsustainable with respect to concepts.

 

The ether was discarded, not the theory of EM waves. Because the ether theory made predictions, which did not come true when tested. Nobody has suggested abandoning Maxwell's equations; they work. You have to get rid of the concepts thats don't work. That's why you test them — to see if they work. The ether was tested and it failed. Relativity was (and continues to be) tested and it passed.

[tar]

Mathematics is not symbols. Neither is mathematics primarily equations or even solutions to equations. Mathematics is not only describable in words, it is in fact described in words -- see any good mathematics text. The symbols are merely shorthand for a great many words. Those words are important The use of words in mathematics is exquisitely precise, and you need to know what they mean.

 

DrRocket,

 

Thank you much for post 117.

 

I am on this talk board for a dual purpose and this serves them both well.

 

One is to test my model of the world against reality and the findings of others (and adjust my model accordingly.)

The other purpose is to investigate language, and the meaning behind the words.

 

To these dual purposes, I will float this;

Math is precise shorthand for a great many words and words in turn are themselves shorthand for a great many meanings. Front and back (the words) have some portion of analogous meaning to +1 + (-1). But let the subject be a woman... and various interpretations are possible in either English or Math when the two terms are used. Futher clarification of what one "means" may be required. Hence the rules and grammar and the "long forms" that more precisely describe which meanings were meant by the statement.

 

But the communication of meaning, is done between two minds that know the same shorthand, and go by the same rules.

 

Which brings us to "that which is meant".

 

Vilas and I have limited knowledge of the shorthand of physics.

 

We do however have full access to reality through our senses, and have each "noticed" the order of things, and have an analogous model of it, resident in our brains. Our models do not "fit" reality exactly. We don't have all the info. But then again we have a lot of info, and the info fits together.

 

We can throw and catch a ball, drive our cars around turns on highways, and do all sorts of calculations and manipulations and predictions and interactions of and with reality, without even once knowing how to solve a partial differential equation. (and maybe Vilas even DOES know how to solve such a thing)

 

Insights that I have had, that are new to me, I later learn have already been had by other minds. And those minds have no doubt progressed to further insights. Difficult to know what insights another mind holds, if you yourself have not had them. But "insights" implies to me, that I have noticed something new about the world, that improves my model of it. The actual world has not changed a wit. (till I "do" something about it)

 

With these twins, we are discussing a few things, comparing models, attempting to see what the other "means" by time dilation, length contraction, speed and position. The actual universe stays the same and fits together the way it fits together.

 

Regards, TAR2

[Vilas Tamhane]

 

I am on this talk board for a dual purpose and this serves them both well.

 

One is to test my model of the world against reality and the findings of others (and adjust my model accordingly.)

The other purpose is to investigate language, and the meaning behind the words.

 

 

I don’t have any alternate model in my mind. It is simply that I find myself unable to agree with the present model.

 

So far as insights are concerned, unfortunately there are very few who are interested in these. You must have noticed that even my legitimate enquiry is treated disdainfully. I can’t help it. The way you are trying for the interaction, I am trying to find out if I make a mistake when I make contradictory statement.

 

 

 

The ether was discarded, not the theory of EM waves. Because the ether theory made predictions, which did not come true when tested. Nobody has suggested abandoning Maxwell's equations; they work. You have to get rid of the concepts thats don't work. That's why you test them — to see if they work. The ether was tested and it failed. Relativity was (and continues to be) tested and it passed.

 

Correct, but enquiry should not be and cannot be stopped.

 

 

[csmyth3025]

...With these twins, we are discussing a few things, comparing models, attempting to see what the other "means" by time dilation, length contraction, speed and position. The actual universe stays the same and fits together the way it fits together.

 

Regards, TAR2

 

When a cosmic ray proton impacts atomic nuclei in the upper atmosphere, pions are created. These decay within a relatively short distance (meters) into muons (their preferred decay product), and neutrinos. The muons from these high energy cosmic rays generally continue in about the same direction as the original proton, at a very high velocity. Although their lifetime without relativistic effects would allow a half-survival distance of only about 0.66 km (660 meters) at most (as seen from Earth) the time dilation effect of special relativity (from the viewpoint of the Earth) allows cosmic ray secondary muons to survive the flight to the Earth's surface, since in the Earth frame, the muons have a longer half life due to their velocity. From the viewpoint (inertial frame) of the muon, on the other hand, it is the length contraction effect of special relativity which allows this penetration, since in the muon frame, its life time is unaffected, but the length contraction causes distances through the atmosphere and Earth to be far shorter than these distances in the Earth rest-frame. Both effects are equally valid ways of explaining the fast muon's unusual survival over distances.

(ref. http://en.wikipedia....ns#Muon_sources )

 

This Wikipedia passage may help in understanding why the seemingly fanciful notion of length contraction and time dilation are real effects that are observed in the real world by researchers who are very particular about being sure of the observations that they publish.

 

Chris

[tar]

Chris,

 

Well OK, this happens. I do not doubt the findings. But WHY the muons act in this way is still open to wondering. After all, this shortening/dilation that the muon experiences would be experienced by ANYTHING and EVERYTHING coming into the Earth with the same direction, speed and mass. The objective conditions of the test site, remain.

 

Regards, TAR2

Edited July 24, 2011 by tar

[csmyth3025]

Chris,

 

Well OK, this happens. I do not doubt the findings. But WHY the muons act in this way is still open to wondering...

Regards, TAR2

I think the main point is that Special Relativity explains both why and how this happens pretty successfully and to a very high degree of predictive accuracy. Remember, when Einstein proposed his theory of special relativity no one had even imagined that such things as muons even existed.

 

Muons were discovered by Carl D. Anderson and Seth Neddermeyer at Caltech in 1936, while studying cosmic radiation

(ref. http://en.wikipedia....ki/Muon#History )

 

Although special relativity may seem counterintuitive to laymen like ourselves, the logical consistency and unrivaled predictive power of the theory makes it rather hard to argue that it doesn't represent the way the world actually works.

 

Chris

[swansont]

Chris,

 

Well OK, this happens. I do not doubt the findings. But WHY the muons act in this way is still open to wondering. After all, this shortening/dilation that the muon experiences would be experienced by ANYTHING and EVERYTHING coming into the Earth with the same direction, speed and mass. The objective conditions of the test site, remain.

 

Regards, TAR2

 

It's a direct consequence of the constancy of the speed of light.

[tar]

Chris,

 

Well, good point. The theory does explain "why" this happens. I yield (mostly.)

 

Would still like to know how many pulsar pulses she would count. According to the theory.

 

Regards, TAR2

[Janus]

J.C. MacSwell,

 

 

 

Overall point being that C is the invariant, but space and time are not arbitrary, they are characterisics of the real arrangement of real particles and fields, and each particle and its position has to "fit" the scheme.

 

And herein is the problem. Space and time are arbitrary,(or more properly, "frame dependent".). As long as you hold onto the idea that time and space a universal constants that have meaning without a frame of reference, you are not going to grasp Relativity. You are trying to understand Relativity by by a applying a "model of reality" to it, that Relativity rejects. Like I said before, it is like trying to understand the spherical model of the Earth while maintaining the notion that "down" is a constant and universal direction.

 

If A is related to B then B is related to A in the opposite manner. If A ticks faster than B then B ticks slower than A. But the distinction makes no sense unless you consider a time period in which A accumulates more ticks than B. Can't go by A's clock, can't go by B's clock. Have to go by C's. (no pun intended)

 

Under the rules of SR time dilation, if you measure B from A, B ticks slower than A, however, if you measure A from B, A ticks slower than B. This is after you factor out any Doppler effect.

 

So let's take a pulsar, 10 thousand light years exactly, from both the sun and Alpha Centuri, that lies on a perpendicular that bisects the path her ship is taking. How many pulses will she count on her trip, compared to the pulses counted by her stay at home twin?

 

 

 

The same number. Though the rate will vary as the trip progresses. At 0.866c, she will see the tick rate go from 3.73 the pulsar source rate to .5 as she's goes from Earth to midpoint and from .5 to 0.268 as she travels from midpoint to Alpha C. Even located at 10,000 light years perpendicular to the flight path there will be a Doppler shift effect.

[Vilas Tamhane]

And herein is the problem. Space and time are arbitrary,(or more properly, "frame dependent".). As long as you hold onto the idea that time and space a universal constants that have meaning without a frame of reference, you are not going to grasp Relativity. You are trying to understand Relativity by by a applying a "model of reality" to it, that Relativity rejects. Like I said before, it is like trying to understand the spherical model of the Earth while maintaining the notion that "down" is a constant and universal direction.

 

Right from Aristotle to the days before SR, physicists always sought reality. World of hallucinations lie only in religious scriptures. I cannot understand how you can object to ‘Model of Reality’. In fact all experiments, without exception, try to establish reality.

 

Reciprocal results of relativity cannot be tested directly in the lab. Because they are apparent and apparent results can never be tested.

 

Your example of spherical earth suggests that, we should not reject counter intuitive theory. At the same time if you take a look at such theories, you will find that all such theories were rational and possible. Earth spins which accounts for day and night. Earth attracts as apple always falls on earth. Earth is spherical as its shadow on moon is always circular.

 

In SR, predicted reciprocal results of length contraction and time dilation are not only counter intuitive but they are irrational and impossible.

 

 

[J.C.MacSwell]

Right from Aristotle to the days before SR, physicists always sought reality. World of hallucinations lie only in religious scriptures. I cannot understand how you can object to ‘Model of Reality’. In fact all experiments, without exception, try to establish reality.

 

Reciprocal results of relativity cannot be tested directly in the lab. Because they are apparent and apparent results can never be tested.

 

Your example of spherical earth suggests that, we should not reject counter intuitive theory. At the same time if you take a look at such theories, you will find that all such theories were rational and possible. Earth spins which accounts for day and night. Earth attracts as apple always falls on earth. Earth is spherical as its shadow on moon is always circular.

 

In SR, predicted reciprocal results of length contraction and time dilation are not only counter intuitive but they are irrational and impossible.

 

According to who? Aristotle?...or Vilas Tamhane? (the one who wrote that no theory was sacrosanct!)

 

Admittedly our former and more intuitive views of space, and especially time, took a beating as SR was established... but something had to give and SR seems to have held up quite nicely as it has yet to be proven wrong.

 

Feel free to try to prove it wrong, but Vilas Tamhane believing it irrational or impossible does not count.

[Janus]

Right from Aristotle to the days before SR, physicists always sought reality. World of hallucinations lie only in religious scriptures. I cannot understand how you can object to ‘Model of Reality’. In fact all experiments, without exception, try to establish reality.

Don't twist my words. I'm objecting to the fact that you are trying to make people explain Relativity to you in a way that fits in with your personal view of what constitutes "reality", a view which happens to be in conflict with the the reality that Relativity describes. You might as well be asking someone to explain why jets travel along a geodesic when traveling from city to city while insisting that they use a flat Earth model in doing so.

 

Reciprocal results of relativity cannot be tested directly in the lab. Because they are apparent and apparent results can never be tested.

 

Your example of spherical earth suggests that, we should not reject counter intuitive theory. At the same time if you take a look at such theories, you will find that all such theories were rational and possible. Earth spins which accounts for day and night. Earth attracts as apple always falls on earth. Earth is spherical as its shadow on moon is always circular.

 

And people who couldn't come to accept the spherical Earth model rejected or tried to "explain away" all of those bits of evidence. Just as you do with the evidence that supports the we live in a Relativistic Universe

 

In SR, predicted reciprocal results of length contraction and time dilation are not only counter intuitive but they are irrational and impossible.

And Flat-Earthers believed just as strongly that a spherical Earth was irrational and impossible. No matter how much it was explained to them, They just knew better. Just like you seem to think that you know better.

[DrRocket]

Vilas and I have limited knowledge of the shorthand of physics.

 

Not only the shorthand, but the actual content. Popularizations and baby talk fail to convey anything other that superficialities -- the mere illusion of understanding.

 

We do however have full access to reality through our senses, and have each "noticed" the order of things, and have an analogous model of it, resident in our brains. Our models do not "fit" reality exactly. We don't have all the info. But then again we have a lot of info, and the info fits together.

 

No, you don't.

 

What has become abundantly clear since the advent of quantum mechanics and relativity, over a century ago, is that your everyday experience, essentially classical Newtonian mechanics, is simply wrong at the atomic level, when dealing with objects moving at high relative speeds, and when large gravitational fields are present..

 

The Newtonian model is a very good approximation when dealing with macroscopic bodies, at low speeds, in moderate gravitational fields. But it is only an approximation, and to understand "reality" requires a more sophisticated perspective, complete with the relevant mathematics.

 

By denying yourself the necessary mathematical sophistication, you are limited to, at best, a nineteenth century understanding of nature.

 

We can throw and catch a ball, drive our cars around turns on highways, and do all sorts of calculations and manipulations and predictions and interactions of and with reality, without even once knowing how to solve a partial differential equation. (and maybe Vilas even DOES know how to solve such a thing)

 

Insights that I have had, that are new to me, I later learn have already been had by other minds. And those minds have no doubt progressed to further insights. Difficult to know what insights another mind holds, if you yourself have not had them. But "insights" implies to me, that I have noticed something new about the world, that improves my model of it. The actual world has not changed a wit. (till I "do" something about it).

 

But what we understand of the world has changed a great deal, and you have opted out of that understanding by remaining ignorant of the mathematics which makes that understanding accessible.

 

With these twins, we are discussing a few things, comparing models, attempting to see what the other "means" by time dilation, length contraction, speed and position. The actual universe stays the same and fits together the way it fits together.

 

Regards, TAR2

 

You are like the blind men attempting to understand the elephant.

 

What is meant by time dilation, length contractiom speed and position is crystal clear to those who understand the relevant mathematics. Those phenomena are in fact a simple consequences of the invariance of the Minkowski metric.

[Vilas Tamhane]

Not only the shorthand, but the actual content. Popularizations and baby talk fail to convey anything other that superficialities -- the mere illusion of understanding.

 

No, you don't.

 

What has become abundantly clear since the advent of quantum mechanics and relativity, over a century ago, is that your everyday experience, essentially classical Newtonian mechanics, is simply wrong at the atomic level, when dealing with objects moving at high relative speeds, and when large gravitational fields are present..

 

The Newtonian model is a very good approximation when dealing with macroscopic bodies, at low speeds, in moderate gravitational fields. But it is only an approximation, and to understand "reality" requires a more sophisticated perspective, complete with the relevant mathematics.

 

By denying yourself the necessary mathematical sophistication, you are limited to, at best, a nineteenth century understanding of nature.

 

But what we understand of the world has changed a great deal, and you have opted out of that understanding by remaining ignorant of the mathematics which makes that understanding accessible.

 

You are like the blind men attempting to understand the elephant.

 

What is meant by time dilation, length contractiom speed and position is crystal clear to those who understand the relevant mathematics. Those phenomena are in fact a simple consequences of the invariance of the Minkowski metric.

 

Your anger and arrogance are not substitutes for reason. On the contrary they are signs of defeat. However you forget that we are not contesting; we are debating and learning. But we are not schoolchildren to say yes to everything you say. In case you find us unworthy, decency demands that you ignore us rather than be intemperate.

 

It is amply proven and stated even by an illustrious persons like Bertrand Russell and Richard Feynman that mathematics is just a tool for calculations. It cannot replace concepts.

 

I request you not to get offended by our expressions. Because opinions of expert like you are valuable to us, but if you wish to gag us then I think that would be unreasonable.

 

So far as ability of mathematics to explain everything, I would request you to explain me what meaning Maxwell’s wave equations convey in absence of ether.