Akinbo,

Your point is a valid one, with no answer except in terms of the unsatisfactory 'domain limits' identified by Einstein. Tom's schema assumes Relativity as it's start point so can't really further address the issue.

My co-author on a few papers is a Minkowski and we've looked at his antecedent's work in much detail. His view was mathematical, and his concepts are hardly truly reflected in the evolved 'interpretation' of Einstein's theory ("the postulates"). [Tom; You may prefer to stop reading here if 'locked in' as above].

Some interesting quotes to give food for thought, including on "length contraction";

Cologne 1908; "Then from here on, we would no longer have space in the world, but endlessly many spaces;" and "Not to leave a yawning void anywhere we will imagine that everywhere and everywhen there is something perceptible...I will use...the word "substance".

(Axiom;) "The substance at any world-point may always, with the appropriate determination of space and time, be looked upon as at rest."

"...we may define this magnitude... (c) as the ratio of the electromagnetic to the electrostatic unit..."

"...cases with a velocity greater than that of light will henceforth play only some such part as that of figures with imaginary co-ordinates in geometry."

That bit is entirely consistent with the DFM's 2ND ('apparent') case of 'speed'. Of LT's length contraction he wrote; "This hypothesis sounds extremely fantastical, for the contraction is not to be looked upon as a consequence of resistances in the ether...but simply as a gift from above,"

Again I agree. There's little there that can't be interpreted as Einstein's 1952 descriptions, distancing his theory from the "interpretive embellishments" so may think IS the theory! Discrete Fields are consistent with his 1952 descriptions, as well as Minkowski's; "endlessly many spaces" which may be in relative motion but within them the substance' is always locally 'at rest'. That's just like 7 'atmospheres' at rest locally but moving at different relative velocities within the solar system.

Back to your original question, the 'curvature' in deep space equivalent to de-Sitter is well described by the LT, precisely equivalent to from diffuse medium refraction (if not then where the refraction DOES emerge needs identifying!)

Best wishes

Peter

    Peter,

    First, since you seem to agree with 'length contraction' and 'time dilation' as mechanisms that keep the arrival time of a wave to observer unaffected by observer motion both of which are mathematically based on Minkowski spacetime, what is your own definition of Minkowski spacetime?

    My proposal is that an earth-bound matter medium makes length contraction and time dilation unnecessary to explain the experimental finding that earth motion has no effect on arrival time of a wave on earth surface (either for sound or for light) completes the similarities of the analogy of the dynamics of light and sound. The 'plasma' as you prefer to call it, if bound to earth as it is therefore does not require LT, time dilation, etc to make light arrival arrival times unaffected by earth motion since it is a light-carrying medium. The dilemma with light is that such earth surface experiments have been done in a vacuum, but I propose that the vacuum secured with baryonic matter as the boundary of the instruments cannot exclude/ constrain dark matter from permeating the light path being not reactive electrically and so not easily repelled or constrained.

    Tom seems to admit that he may sometimes resist not answering honestly and it may be fun "hedging, hemming, hawing or bloviating"

    Regards,

    Akinbo

    Akinbo,

    I agree your description can be interpreted as true. It's capable of different interpretations and more precise specification is needed as it's far from 'complete'. (i.e. light 'arrival' from where? arrival time wrt which other scenario? and; "does not require the LT" ..at all as an observed effect? or just as 'interpreted'. The Lorentz Factor does of course consistently model real findings.

    The 'boundaries' of instruments aren't required to exclude 'dark matter' because the surface transition zones/plasmons/free electron fine structure is MADE OF the fermions (or 'dark matter') at rest in each frame, which do the job by scattering to the local c.

    Light transmitted across a vacuum chamber then does c wrt the emitter. If you blow a few particles around within it you'll find some 'scintillation'.

    If the detector is in motion through the vacuum; it's free surface electrons re-scatter the light to the local (detector) speed c ready to 'measure'.

    Minkowski space-time is simply a convenient mathematical 'short-cut' approximation. Nobody back then thought there was ANYTHING in space so it was a useful formulation. However to cling on to it as a precise model of nature's real mechanisms is quite delusional.

    If you and a pal await a light signal, and he starts moving forward, those clinging on to old myths will think he slows down the speed of light heading for him (not you) at infinite range! The DFM simply points out it doesn't need to change speed until it arrives and interacts!

    Best wishes

    Peter

    Thank you JRC and Tom for directing me to resources on Minkowski spacetime on the 'Why Quantum' blog. These have kept me busy. The 27-pages of I. What to Trust to Avoid Believing in Illusions written by Petkov was very well written and interesting, even if misleading.

    Quoting excerpts from there as well as from II. Space and Time: Minkowski's Papers on Relativity, a few deductions can be made.

    p.5 of I: "However, according to the modern theory of gravitation - general relativity -falling bodies move by inertia since their fall is not caused by a gravitational force, but is a manifestation of the curvature of spacetime in the Earth's vicinity (induced by the Earth's mass)".MORAL: Spacetime is NOT flat on Earth surface.

    p.33 of II: "Another example of why special relativity (as we now call the physics of flat spacetime) would be impossible in a three-dimensional world is contained in Minkowski's four-dimensional explanation of the physical meaning of length contraction,..." MORAL: Special relativity and accompaniments like time dilation and length contraction belong to flat spacetime.

    p.4 of II: "Given the fact that it is only Minkowski's four-dimensional physics that provides the correct explanations of the relativistic effects (...), it is difficult to understand the reluctance and sometimes even resistance against explaining the kinematical relativistic effects as manifestations of the four-dimensionality of the world as Minkowski advocated". MORAL: Minkowski spacetime can therefore ONLY provide the correct explanation for experiments on Earth such as the Michelson-Morley results, IF, AND ONLY IF the spacetime in the Earth's vicinity were flat, UNFORTUNATELY it is not.

    Hence Einstein's lamentation, "Since the mathematicians have invaded the relativity theory, I do not understand it myself anymore". Therefore, if V. Petkov wants to be honest, he should realize that there is something in theory and science called 'domain of applicability'. Is it correct science to use what is not applicable in a particular domain to provide 'the correct explanation' for the experimental findings in that domain?

    Is it then a suprise, if physics is yet to recover from this faux pas?

    In Law, if you build an architectural masterpiece on someone else's landed property, you build in vain as what you built no matter how elegant does not still belong to you the builder. SR is a beauty but it is not built on Flat Land so whoever buys such property buys nothing.

    Regards,

    Akinbo

      "MORAL: Spacetime is NOT flat on Earth surface."

      Locally, yes it is. If you know Galilean relativity, you know that objects fall at the same rate in a gravity field, whether they follow a straight path or a curved path. Take, for example, an airplane dropping a bomb; assuming that the airplane continues on course without accelerating, the bomb will remain directly below the craft its entire journey to the Earth's surface. This can only happen in a flat plane, because there is no horizontal acceleration component -- all the acceleration is vertical, the dead weight of the bomb accelerated only by gravity.

      "MORAL: Special relativity and accompaniments like time dilation and length contraction belong to flat spacetime."

      Exactly right. See above.

      "MORAL: Minkowski spacetime can therefore ONLY provide the correct explanation for experiments on Earth such as the Michelson-Morley results, IF, AND ONLY IF the spacetime in the Earth's vicinity were flat, UNFORTUNATELY it is not."

      Um, yes it is. As Einstein relativity shows, the universe is Euclidean on the average. When laymen speak of "curved spacetime" they don't normally envision the actual mathematics, much less try to solve the equations -- they think of a picture, a curved line on a piece of paper. That isn't the case.

      Like Pentcho, you must actually learn what Einstein relativity is, before you can be an effective relativity-denier.

      To prevent me from "hedging, hemming, hawing or bloviating", firstly, what is the size of LOCAL and secondly, what does LOCAL mean mathematically and in physics?

      Then take note that I am not a relativity-denier. On the contrary, I support relativity, but the one in which in the coordinate system

      ct, x, y, z

      c is a vector quantity, while t, x, y, z are scalar, not the one in which

      c is a scalar, while t, x, y, z are vectors. There is a physical, observable and explainable difference, even if mathematicians want to reverse their properties and foist paradoxes and absurdities of time dilation and length contraction on us.

      There is claimed to be no role for gravity or acceleration in SR so no need to introduce it unless you want to propose a variant of SR.

      Regards,

      Akinbo

      "what does LOCAL mean mathematically and in physics?"

      You need to go to primary sources for this, as I told you. You won't believe anything I say. Here is as easy as I can make it:

      Locality, mathematically, refers to the relation between a point of origin -- an initial condition, zero -- and another point or set of points differentiable from the origin.

      Locality, physically, refers to events within causal distance of one another.

      Akinbo, Minkowski space has the metric signature +++- or ---+. You have to understand what that means before you even begin to talk about vectors and scalars and how they relate.

      Go to the sources. Don't get your education in internet blogs.

      Yes Tom. I know Minkowski space is described with +++- or ---+.

      "You have to understand what that means before you even begin to talk about vectors and scalars and how they relate"

      In the good old days of physics, when truth was sacred before mathematicians invaded the temple you didn't have to understand the symbols +++- or ---+ before talking physics. Einstein never had to before proposing his theory. It was Minkowski his teacher who started all this and I am sure you are aware of Einstein's aversion to the +++- and ---+ methods of his old math teacher.

      Locality, mathematically, refers to the relation between a point of origin -- an initial condition, zero -- and another point or set of points differentiable from the origin. This appears to be going round in circles. What is the distance between the points?

      Locality, physically, refers to events within causal distance of one another.. Still hedging, hemming and hawing. Causal distance in Einstein's relativity implies that which is within the reach of an incoming light signal. On Earth surface, there are no events that are not within causal distance of one another by which definition therefore, Earth surface is LOCAL. Despite this Locality, Earth surface is NOT FLAT. So Locality does not translate to Flatness.

      "MORAL: Spacetime is NOT flat on Earth surface.". Locally, yes it is.. Same response as above.

      By the way, in this paper, it is said that Earth, like the Sun can deflect light. This supports that Earth spacetime is NOT flat. This is a Big headache for SR and Minkowski's prescription.

      You won't believe anything I say.. I really, really wish I could, but let's keep trying and thanks all the same.

      Regards,

      Akinbo

      "You won't believe anything I say.. I really, really wish I could, but let's keep trying and thanks all the same."

      If I can't trust you to go to the sources, Akinbo, we can't have a dialogue.

      Tom,

      Okay, Minkowski sets his working limits and qualifies them such that measures will all be real not negative values within the parameter of light velocity as an absolute value, hence the metric of three like signs and one opposite. That qualification presupposes time asymmetry and it would be moot to speculate what might or might not come from an agreed upon rationale as to 'why' the asymmetry, it's not in the toolbox.

      It is clear from Petkov's intro that operating with two points of reference for any 'substantial point' in Minkowski's rationale provides a definite locality that isn't apparent in SR, though both methods should achieve the same end.

      Your brief comments on 6/30 include, "Applied to physics, the Minkowski formulation is conceptually easy and operationally hard," which hit me right off the bat (being a mathophobic), because in the teaser excerpts of the translation, Minkowski immediately dives into his arsenal of math. Kindly, sir, (I want some more porridge) do share your thoughts on why he starts with the hyberbola. What is assumed, or what did I not get to begin with?

      Sorry to barge in on this thread, the book price is modest to support the efforts but right now I need to budget for pre-winter vehicle maintenance. I think where conceptually there is resistance to 'inertial motion' along a worldline, is what seems to be contradictory with the acknowledgement by both Minkowski and Einstein that fields, or 'something(s) perceptible', exists throughout universal space//time. So What? I don't want to dance on the bar and start fights, but there would be a worldline of the magnetic equilibrium between simple macro-magnets which is experimentally interior to the domain of effect, also. And the same might be true of the neutral plane in electrical appliance. So why the hyberbola? Your thoughts are always appreciated. jrc

      If I can't trust you to go to the sources, Akinbo, we can't have a dialogue.

      Tom, I have gone to the sources. Going to sources is indispensable for doing science but relying solely on sources retards the progress of science.

      Galileo went to sources, but if he merely went to them we will not know till this day that the Earth moves round the Sun. As Newton is quoted to have written concerning sources, "Plato is my friend, Aristotle is my friend, but my greatest friend is truth"1.

      I note here that you have yourself disagreed with sources particularly in your defense of Joy Christian's work. So much about sources.

      On this topic of space-time, on viewing the sources which you and JRC referred me to, I point out that Minkowski prescribed a very good medicine meant to cure patients suffering from flat spacetime to a patient suffering from curved spacetime. No wonder then that the patient remains sick despite taking the drug for more than 100 years! Do you advise we continue administering this medicine till the patient finally dies or to change the medicine?

      Finally, one reason why sources must be questioned is that new observations/ experiments previously unknown to the source may have come to light. Einstein for example says his position was based on "...unsuccessful attempts to discover any motion of the earth relatively to the 'light medium'...", but Steve Agnew just posted a beautiful picture of the CMB on the Why Quantum blog showing successful attempts that discover the motion of the Earth! The task then is to reconcile the correct but discordant findings of unsuccess and success.

      Regards,

      Akinbo

      1. Newton, The Man by J.M. Keynes, p.22

      "I note here that you have yourself disagreed with sources particularly in your defense of Joy Christian's work. So much about sources."

      Absolutely untrue. Cite the example by which you support this.

      I can't search the threads for evidence. Is John Bell's paper not a source? In any case what you appear to be saying is that a source represents absolute truth and is sacred so that it cannot be falsified?

      • [deleted]

      "That qualification presupposes time asymmetry ..."

      No it doesn't. Every model of classical, continuous function, physics explicitly implies time symmetry (the equations work equally well forward and backward in time). This is one of the bedrock assumptions of spacetime -- I believe what you are thinking of is the asymmetry of time in the cosmological problem.

      The Minkowski metric describes an isotopic spacetime in flat Euclidean space absent of matter. Special relativity agrees; the Lorentz transformation accounts for time symmetry by a fixed point that guarantees the symmetry of two events in the spacetime interval.

      When special relativity is generalized, we encounter a pseudo-Riemannian metric of Lorentzian metric properties (sometimes simply called the Lorentz metric) -- this means there is no privileged coordinate frame, no fixed point by which time symmetry is guaranteed in a continuum of uniform motion. Instead, the local flat metric of Minkowski space is continuous with the globally curved Riemannian manifold -- leading to the cosmological asymmetry of time; i.e., the singularity of creation. Short of the beginning of time itself, all observer relations are nondegenerate, meaning there is objective differentation in spacetime between observer and observed, and the symmetry of those relations guarantees equal validity of each observer's measurement. No privileged frame.

      "Your brief comments on 6/30 include, "Applied to physics, the Minkowski formulation is conceptually easy and operationally hard," which hit me right off the bat (being a mathophobic), because in the teaser excerpts of the translation, Minkowski immediately dives into his arsenal of math. Kindly, sir, (I want some more porridge) do share your thoughts on why he starts with the hyberbola. What is assumed, or what did I not get to begin with?"

      The Minkowski diagram is a graphic device to help us visualize the difference between spacelike separated (hyperbolic) events and timelike (parabolic) events in a simplified continuum of one dimension of space and one dimension of time. When we add the complication of observers in different states of relative motion, we can comprehend visually the effects of time dilation and length contraction described by the mathematics of the Lorentz transformation.

      "I think where conceptually there is resistance to 'inertial motion' along a worldline, is what seems to be contradictory with the acknowledgement by both Minkowski and Einstein that fields, or 'something(s) perceptible', exists throughout universal space//time. So What?"

      Well, if "no space is empty of the field," no space is empty of observation (no nonlocality) even in spacelike separated events.

      In fact, bodies do not resist their motion, as Petkov elegantly explains in this FQXi essay.

      "I don't want to dance on the bar and start fights, but there would be a worldline of the magnetic equilibrium between simple macro-magnets which is experimentally interior to the domain of effect, also. And the same might be true of the neutral plane in electrical appliance. So why the hyberbola?"

      Although gravitational and electromagnetic field influences are both infinite, they are not the same thing. Remember, the electromagnetic field is symmetric in time while the gravitational field operates only in the one direction -- toward the center of mass. It's the presence of matter in the universe that breaks symmetry at the singularity of creation, which is why in terms of geometry, Einstein's theory of gravity (general relativity) applies only up to diffeomorphism.

      Thanks Tom, let me chew on all that a bit. I can't imagine from what he envisioned for practical physics that Minkowski believed mathematical time symmetry to be the reality, and 'set his working limits' accordingly. jrc

      TIME IS REAL BUT IT HAS ONLY A MATHEMATICAL EXISTENCE.

      " ... In any case what you appear to be saying is that a source represents absolute truth ..."

      You know that's unwarranted. I am saying that you are talking about something completely different from what the literature says. You have picked up a bad habit from Pentcho Valev, of trying to fit naive opinions -- Procrustean style -- into places they don't fit, by picking up out-of-context quotations here and there.

      Classical mechanics, including relativity, is well understood and well tested in its applicable domain. It is as true as any scientific theory can be. Get hold of Susskind/Hrabovsky, The Theoretical Minimum published recently. and Einstein/Infeld The Evolution of Physics published in 1938. These are accessible, clearly written introductions to classical physics.