god I can't read

Let see what good old albert had to say on the matter:

Taken from:
http://philsci-archi.../1/bubfest2.pdf

Einstein would have preferred a constructive account of these relativistic e?ects, presumably based on the nature of the non-gravitational forces that hold the constituent parts of rods and clocks together. But as we have seen, for Einstein the elements of such an account were not to be had in 1905. The price to be paid for the resulting strategic retreat to a principle theory approach was not just loss of insight...

One is struck [by the fact] that the theory [of special relativity] . . . introduces two kinds of physical things, i.e., (1) measuring rods and clocks, (2) all other things, e.g., the electromagnetic ?eld, the material point, etc. This, in a certain sense, is inconsistent; strictly speaking measuring rods and clocks would have to be represented as solutions of the basic equations (objects consisting of moving atomic con?gurations), not, as it were, as theoretically self-su?cient entities. However, the procedure justi?es itself because it was clear from the very beginning that the postulates of the theory are not strong enough to deduce from them su?ciently complete equations . . . in order to base upon such a foundation a theory of measuring rods and clocks. . . . But one must not legalize the mentioned sin so far as to imagine that intervals are physical entities of a special type, intrinsically di?erent from other variables

[/quote]


The principle theory albert proposed was nothing but a patch waiting to be replaced by a theory of what holds matter together to actually form rules and clocks. Unlike Einstein, we have that nowadays (QED, interference patterns of virtual photons going back and forth, and so on). Properly understood, what the MM-experiment illustrates, is that the two-way speed of light of the photons inside the apparatus equals the two-way speed of light of the photons making up the apparatus. And like any good tautology, it holds in every reference frame.

Axiomatic relativity should have gone the way of the dodo half a century ago (as eloquenty argued by Bell too, cant find his original paper, but this is a decent drop in replacement: http://en.wikipedia.org/wiki/Bell's_spaceship_paradox), but people are too busy kissing Einsteins ass to even read what the man said himself.
[/quote]
I feel you are making very bold statement here:

MM experiment performed with apparatus, that is not hold together by electromagnetic forces does not necessarily confirm the constancy of the speed of light.
Ok, ok I know - everything except gravity seems to be unified now and there is little hope of building a measuring mechanism entirely of miniature black holes. And even then - the best theory of gravity we have thus far predicts that it behaves well in MM experiment.

Still the question remains - is it theoretically possible, that there are certain phenomena that a) interact with photons (directly or indirectly) and b) does not behave according to STR. If not, then why not (we cannot rely on spacetime geometry here) and if yes, then what does it imply about causality, randomness and such sweet things?

More seriously (from philosophical side) - this is not about whether measuring devices are independent or not - it is about the ontological status of time and space. Physics does not prescribe us any specific ontology (more precisely, it excludes bunch of ontologies and is completely orthogonal to others). You may hold a view, that there is spacetime with certain geometry that dictates certain rules to everything else. Or the view, that there is no such thing - after all we can only detect events (that follow certain other rules) and infer the existence of space and time from those events.

[quote name='Eelco' timestamp='1320326028' post='4880112']
Let see what good old albert had to say on the matter:

Taken from:
http://philsci-archi.../1/bubfest2.pdf

Einstein would have preferred a constructive account of these relativistic e?ects, presumably based on the nature of the non-gravitational forces that hold the constituent parts of rods and clocks together. But as we have seen, for Einstein the elements of such an account were not to be had in 1905. The price to be paid for the resulting strategic retreat to a principle theory approach was not just loss of insight...

One is struck [by the fact] that the theory [of special relativity] . . . introduces two kinds of physical things, i.e., (1) measuring rods and clocks, (2) all other things, e.g., the electromagnetic ?eld, the material point, etc. This, in a certain sense, is inconsistent; strictly speaking measuring rods and clocks would have to be represented as solutions of the basic equations (objects consisting of moving atomic con?gurations), not, as it were, as theoretically self-su?cient entities. However, the procedure justi?es itself because it was clear from the very beginning that the postulates of the theory are not strong enough to deduce from them su?ciently complete equations . . . in order to base upon such a foundation a theory of measuring rods and clocks. . . . But one must not legalize the mentioned sin so far as to imagine that intervals are physical entities of a special type, intrinsically di?erent from other variables

[/quote]


The principle theory albert proposed was nothing but a patch waiting to be replaced by a theory of what holds matter together to actually form rules and clocks. Unlike Einstein, we have that nowadays (QED, interference patterns of virtual photons going back and forth, and so on). Properly understood, what the MM-experiment illustrates, is that the two-way speed of light of the photons inside the apparatus equals the two-way speed of light of the photons making up the apparatus. And like any good tautology, it holds in every reference frame.

Axiomatic relativity should have gone the way of the dodo half a century ago (as eloquenty argued by Bell too, cant find his original paper, but this is a decent drop in replacement: http://en.wikipedia.org/wiki/Bell's_spaceship_paradox), but people are too busy kissing Einsteins ass to even read what the man said himself.
[/quote]
I feel you are making very bold statement here:

MM experiment performed with apparatus, that is not hold together by electromagnetic forces does not necessarily confirm the constancy of the speed of light.
Ok, ok I know - everything except gravity seems to be unified now and there is little hope of building a measuring mechanism entirely of miniature black holes. And even then - the best theory of gravity we have thus far predicts that it behaves well in MM experiment.

Still the question remains - is it theoretically possible, that there are certain phenomena that a) interact with photons (directly or indirectly) and b) does not behave according to STR. If not, then why not (we cannot rely on spacetime geometry here) and if yes, then what does it imply about causality, randomness and such sweet things?[/quote]
Im not the one raising the observation that all massless particles are moving at the same speed to an axiom; how exactly does that make me worse off? Yes, if you had particles behaving otherwise, you could triangulate a rest frame; good for you, nothing for me to get my panties in a bunch over. Interesting, for sure, but entirely consistent with a constructive rather than axiomatic explanation of the observation regarding relativity.

People used to solely leaning on their axiomatic relativity of course do very much get their panties in a bunch (as shown recently) over elementary particles seeming like they might not move at the same speed as the ones studied so far. Typically, it also takes a few days of heated argumentation to convince them you can triangulate a rest frame in a closed universe, which is just another example of why one should be cautious in generalizing from the particular to the general. Yes, it pretty much seems like all particles weve observed (or maybe not, but ok) act according to the axioms of relativity. And yes, the sun has always risen in the east. But does one gain any insight by explaining tomorrows sunrise by the 'axiom of eastern sunrises'? Is noting a generality the same as 'explaining' it? I dont think so.

To explain something, is to be able to reduce it to the consequence of something more elementary. Principle theories, by definition, do not purport to reduce. Rather, they are a checkpoint that your reasoning must pass; those axioms which force one to deduct the content of the principle theory are valid. Special relativity does not explain MM: it shows us that its not all bad, logically consistent, fits the facts, and asks us to put up with it. To shift those axioms to isomorphic axioms about spacetime geometry is more of the same; it doesnt *explain* anything, in the sense noted above.

To explain MM by looking at what that x 'meters' long arm of the MM apparatus is actually made of (a fixed number of charged particles bound into a specific configuration by lots of interfering photons), is rather different from throwing up your hands, and saying that from now on we should only accept physical theories that respect the constancy of the speed of light, cause apparently thats the way it is. The latter is not an explanation, it is a resignation. Which at some point in history was perfectly justified, but certainly not nowadays.

To explain MM by looking at what that x 'meters' long arm of the MM apparatus is actually made of (a fixed number of charged particles bound into a specific configuration by lots of interfering photons), is rather different from throwing up your hands, and saying that from now on we should only accept physical theories that respect the constancy of the speed of light, cause apparently thats the way it is. The latter is not an explanation, it is a resignation. Which at some point in history was perfectly justified, but certainly not nowadays.

Okay, you are quite convincing as long as I can follow.

Are you basically arguing, that we shouldn't accept overly general axioms of SRT, because identical behaviour can be derived from the (more specific) axioms of "whatever is current field theory" for all imaginable observations?

General axiom being "all events in space-time are elated such-and-such"

Specific axioms being "all fields/particles in certain set behave such and such"

And general terms like "simultaneity", "past" and "future" not having any theoretical meaning?

[quote name='Eelco' timestamp='1320344737' post='4880218']
To explain MM by looking at what that x 'meters' long arm of the MM apparatus is actually made of (a fixed number of charged particles bound into a specific configuration by lots of interfering photons), is rather different from throwing up your hands, and saying that from now on we should only accept physical theories that respect the constancy of the speed of light, cause apparently thats the way it is. The latter is not an explanation, it is a resignation. Which at some point in history was perfectly justified, but certainly not nowadays.

Okay, you are quite convincing as long as I can follow.

Are you basically arguing, that we shouldn't accept overly general axioms of SRT, because identical behaviour can be derived from the (more specific) axioms of "whatever is current field theory" for all imaginable observations?

General axiom being "all events in space-time are elated such-and-such"

Specific axioms being "all fields/particles in certain set behave such and such"
[/quote]
Yes, that pretty well sums it up.

And general terms like "simultaneity", "past" and "future" not having any theoretical meaning?
[/quote]
Im not sure what you mean by that. Actually, since it is theoretically and experimentally possible (and intuitively pleasing, at least to me) that the universe is finite in extent and closed, a good theoretic basis should allow for this possibility. And if the universe is indeed such, then there must be such a thing as a rest frame, hard to find as it may be, and there is such a thing as the one 'true' time, 'real' simultaneity, and distorted perspectives thereon.

The biggest problem is that all this thought is based on some guy's theory about something we cannot measure or even understand (time!). Which means that no matter what thoughts one may have, we will not be able to prove or reject them. Yes, there's for example Hafele and Keating, but honestly so what.

What is time? Nobody knows. How do you measure time? Again, nobody knows.

We can measure changes in the electromagnetic spectrum of some caesium atoms, or worse, we can observe moving objects doing tic-tac-tic-tac. We assume that whatever we observe there is something periodic, regular, and immutable, and thus a measure of "time". We further assume that e.g. an atom's electromagnetic spectrum is not influenced by acceleration or cosmic radiation, or bogons, or a million other things that we do not know about. Lorentz (the guy Einstein stole most of his ideas from) had some imagination of "Ether", whatever that was supposed to be. We mostly assume that's complete bollocks today. But is it really, how can we be so sure?

It is very well possible that Einstein's theory is wrong, and it is very well possible that any experiment we do to "measure time" is wrong, because we simply can't grasp time correctly.

The biggest problem is that all this thought is based on some guy's theory about something we cannot measure or even understand (time!). Which means that no matter what thoughts one may have, we will not be able to prove or reject them. Yes, there's for example Hafele and Keating, but honestly so what.

What is time? Nobody knows. How do you measure time? Again, nobody knows.

We can measure changes in the electromagnetic spectrum of some caesium atoms, or worse, we can observe moving objects doing tic-tac-tic-tac. We assume that whatever we observe there is something periodic, regular, and immutable, and thus a measure of "time". We further assume that e.g. an atom's electromagnetic spectrum is not influenced by acceleration or cosmic radiation, or bogons, or a million other things that we do not know about. Lorentz (the guy Einstein stole most of his ideas from) had some imagination of "Ether", whatever that was supposed to be. We mostly assume that's complete bollocks today. But is it really, how can we be so sure?

It is very well possible that Einstein's theory is wrong, and it is very well possible that any experiment we do to "measure time" is wrong, because we simply can't grasp time correctly.

Be careful... If you are asking questions like "what is time" you have already left physics and entering philosophy.

Philosophers have known at least from the time of Kant and Nagarjuna, that there is always gap in all of our knowledge. This is logical problem and thus no theory - neither physical nor philosophical can ever close it.
The best we can hope for is as coherent, logical and simple mathematical model as possible - that predicts all outcomes of actually performed measurements/observations. Nothing more. For physicist the simplicity and power of this model is argument for the ontological status of the phenomena in it. For phenomenalist it is not.

As an illustration of the consequences of knowledge gap, take "brain in a vat" to whom the experimentator is showing movie about certain universe - which has mostly logical and coherent structure with one caveat. While "brains in a vat" are extremely common in the "true" universe, they are mostly "non-existant" in the movie universe. Thus the brain rejects the idea that it is itself a "brain in a vat" based on its expectations about the rational properties of the theory of universe. But this "rationality" is actually only the consequence of there being no "brains in a vat" in the movie...

Notice, that in neither universe one can disprove being a "brain in a vat". But in one universe this notion satisfies the expectations about the rational ontology, in another universe is universally rejected because it is unintuitive and void of content.

My own theory behind it, which could be completely wrong. Time is relative by object and proximity. The proximity of gravity will stretch time, or alter it, while the object's since of time will change. Globally time would remain the same between the two objects, however the perception of time would alter. It's like looking at an object heading into singularity. The object appears frozen in space to all perspectives outside of the field of influence, however the object it's self would feel time being normal, and is still moving.

So in layman's term, the spaceman McGee and the earthling would both be alive at the same time without an altered age. Also remember, two astronautics who are in space for two months, would not be up their for five minutes. If they didn't shave they would come back with full beards and two months older looking.

Another thing to remember, is everything is just a theory. Relativity is now currently broken thanks to nuetrinos, and not to many people on earth could actually understand the concepts behind it. So far only four or six people actually know it by heart. If the theory of relativity was true, and vectors applied to it, then it would mean that time travel would in fact be possible.

My own theory behind it, which could be completely wrong. Time is relative by object and proximity. The proximity of gravity will stretch time, or alter it, while the object's since of time will change. Globally time would remain the same between the two objects, however the perception of time would alter. It's like looking at an object heading into singularity. The object appears frozen in space to all perspectives outside of the field of influence, however the object it's self would feel time being normal, and is still moving.

Interesting. Have you published papers on this? What evidence is there to support it, or what experiments to test it?

Another thing to remember, is everything is just a theory. Relativity is now currently broken thanks to nuetrinos, and not to many people on earth could actually understand the concepts behind it. So far only four or six people actually know it by heart. If the theory of relativity was true, and vectors applied to it, then it would mean that time travel would in fact be possible.[/quote]Everything is not "just a theory". Firstly, "theory" in science means something that is supported (often overwhelmingly) by evidence. There is no next thing to progress to - something only stops being a theory if it is discredited. So "just a theory" makes no sense - it's one of the strongest terms that can be used for a model.

And not everything is theory - we have laws (actually rules of thumb incidentally, and not something that is more true than a theory - many laws are known to be untrue approximations, e.g., gas laws), hypotheses, conjecture. The lay usage of "theory" is what in science would be conjecture or at best a hypothesis.

No theory we have today is 100% correct, though I'm not sure I would say that makes them "broken"; relativity is still a very accurate description of reality in most situations. (And we're still not clear what's really going on with the neutrino result - more testing is needed.)