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(A little catch-up) me: swansont: “Dishonestly restrict?” There is no experimental evidence for large scale length contraction, yet you and Cap ‘n R are insisting that an almost flat earth is just as valid ("real") as its extremely well verified nearly spherical shape. Something is very wrong with that, if not "dishonest." Then you compare lack of length contracted evidence to some imagined lack of evidence for gravity.(??) I really don’t get your drift on that one. Everywhere on earth gravity is verified, as well as throughout the cosmos. Mass attracts mass. What kind of verification are you asking for. What goes up comes back down. The whole space exploration program is based on very specific knowledge of how gravity works This is a nonsense challenge and comparison of verification of gravity to verification of length contraction. View Postmichel123456, on 14 August 2011 - 07:47 AM, said: Cap 'n R: How about the one in which earth is severely oblate? Or are you in the reality where it is nearly spherical. You still can't have it both ways if there is "one reality" and earth does not morph with each different frame of reference.

I'll pretend this is the ontology of time thread. ("My three threads* are naturally interwoven anyway. This and ontology of both time and spacetime.) It may or may not be helpful to ask how one conceives of a boundary around "now" as a local present, as distinguished from a universal present without such a local boundary. In other words we all know that it takes time for light to travel through space to carry images and information... simple signal delay on all scales. But, of course (repeating) now IS now here and on the sun (and everywhere, if no "now boundaries"), even though obviously we will not see sun's now for over eight more minutes. The same can be said for time, if we set aside the familiar model of "time cones" for "now." Granting signal delay, what is the argument against presentism as "The present IS present everywhere?" jspfsx: So, do you believe that earth IS a very oblate spheroid "for" the above extreme FOR, and earth IS nearly spherical "for" those seeing it (and living on it) in an at-rest frame? Can it be either or both, depending on how you see it? If so, in what way is "earth IS how you see it" NOT subjective idealism with FOR as subject? Iggy: On the grounds that everything is moving and velocity requires specificity as to "moving how fast relative to what."(as I've said a few time already.) Whereas, (as I've also repeated many times) realism posits that objects have intrinsic properties like shape, size, density, rigidity, etc., independently of how (or if) they are seen from whatever FOR. Likewise, the distance between bodies, is also intrinsic as above, depending only on their movement relative to each other (closer or further away), i.e., one AU or about 93 million miles between earth and sun. This does not change just because a high speed traveler might see that distance as, say 1/8th the standard AU. That would mean that perception creates reality, the idealist belief, contradicting the realism that insists that the only variation in that distance is due to the irregularity of the elliptical orbit, sometimes closer, sometimes further. Cap 'n R: Referring to my recent comments on the non-Euclidean claim of four spatial dimensions, can you explain what the fourth axis of space is beyond the well known three, the line, plane and volume? If the fourth is just the time factor (elapsed time during movement of objects), then how does that create the "four dimensional slices of reality," model which you like so well? You said that earth's shape does not change (radically.) Yet it IS nearly flat as seen from one FOR and nearly spherical from the at rest FOR. Now you say that "The three-dimensional shapes of objects change..." by adding a "weird" (previous post) fourth dimension. This looks to me like either a blatant contradiction or creation of a metaphysical mystery dimension out of nothing/nowhere... like the claim of seven extra dimensions (11 total) in M-Theory. How is your fourth dimension different than those seven, with no basis at all in empirical science?

So, as per thread title: Is there an objective world/cosmos with intrinsic properties independent of observation/measurement (realism) or does reality depend on how things are perceived (i.e., from different frames of reference?) me: Cap 'n R: So, as per idealism, you assert that earth can be both nearly spherical and very oblate, depending on how you look at it (from different frames of reference), denying realism's "objective world/cosmos with intrinsic properties independent of observation/measurement." This is nonsense, but it does show clearly, without a doubt where the length contraction aspect of relativity falls in the title challenge. I am done. Swansont from post 131: From post 135: . More nonsense, times two. I ,like everyone else, stick to the ground as I walk and, as already pointed out, to my living room floor. Apples fall from trees to the ground today as in Newton's day. What a bogus challenge! Btw, I understand the classical Einsteinian principle or thought experiment that one in an enclosed box (or whatever) can not know if he is on earth sticking to the floor because of earth's gravity or being accelerated through space in the "up through the ceiling" direction. So, If this is your point, ... I do not live in an enclosed box.

Are you referring to non-Euclidean 4-D space (four spatial dimensions), the fourth of which exists only in the minds of non-Euclideans) or 3-D space plus time, the movement factor (not in dispute?) If the former, the "weird effects" are in the minds of those who add an extra dimension to 3-D space (which describes all volume.) If the latter, then spherical 3-D bodies in 3-D space remain spherical, without "weird" distortions. Btw, TAR, None of us are sticking to title topic here. No problem.

swansont: Earth can not be both nearly spherical and very oblate. It must be one or the other. Are you with me so far? Which is it? If length contraction is a "valid scientific model", then it all depends on how you look at it... which is idealism and you deny the above "air tight" logic. I can't help but notice that you constantly dodge the challenge to show experimental evidence that length contraction is valid outside the particle accelerator, yet you turn it around as if it is up to me to disprove length contraction applied to earth. Iggy, 124: “Can’t answer?” Did already, many times. 131: I’ve said the following many times: That everything is moving everywhere, so velocity requires a specific reference, i.e., relative to what? I argue that at rest (no relative velocity between observer and observed) is the preferred frame for objective accuracy of measurement.... that “it all depends on frame of reference” is idealism, not realism, in which things are as they are, independent of perspective. We investigate "reality" by minimizing unknown variables, like extreme hypothetical frames from which to measure. My silence has been in keeping with the following, which you have ignored in order to falsely assume the above: From my post 117: (This exception for clarification only.) Tar, Your conversation with Iggy on presentism/simultenaity (what “now” means) belongs in the Ontology of Time thread.

Cap ‘n R: No doubt, “in earth’s reference frame," but... To recap: You said that from near lightspeed fly-by frame of reference earth IS severely oblate, and, since there is “no preferred frame of reference” in relativity, that is just as accurate a description as nearly spherical. I maintained that the latter is the accurate, realistic, objective description, and, since earth does not change from one shape to another, one is right (“preferred”), nearly spherical, and the other wrong, very oblate. OK? swansont: I was talking about an actual straight line as the shortest distance between two points (Euclidean), whether on a flat map or *through* a spherical globe. No one is arguing against lines on the surface of a globe being curved. Correspond? Sure, if you break down the globe and make it into a flat map. What’s the point? A curved line is not a straight line. The shortest distance between two bodies in space is still a straight line. Planetary orbits are not straight lines through “curved space." They are curved lines through empty space, which is (arguably... see spactime ontology thread)) not *something* that can be curved. “Curved space” is a non-Euclidean concept, begging the ontological question, “what is it that is said to be curved”, besides the trajectories of objects as pulled by gravity?

I quick reply. No "time." More later. swansont: The assumption that all frames of reference yield equally valid results? (I’m guessing you think I am “wrong.”) Realism 'realizes' that cosmos is intrinsic physical reality on its own, independent of how it is perceived. So science’s job, investigating that reality, is to always find the observational perspective with the fewest errors due to unknown variables. I’m "guessing" that viewing earth from a near lightspeed fly-by will not have the fewest errors of perception. Idealism, in general, asserts that cosmos is as cosmos appears, like from various frames of reference. So there are as many different "versions" of it as there are perspectives or frames of reference. This is as simple as I can state it. ( Btw,this should be in the frame of reference thread in Philosophy.) I thought I had answered this many times ,and now again above. “Under the microscope” (at rest with the object examined) will clearly give the better results for properties of a micro-organism than some futuristic high tech scanning as one flies through the lab at near lightspeed. There is no reasonable argument against this. Likewise, the closer the observer is to earth, at rest, the fewer unknown variables to introduce error. A perfectly sound principle of scientific investigation. If you are so certain that the length-contracted version of earth’s shape is equally correct, why don’t you present experimental, objective, empirical evidence to support it? (Thought experiments are creative guess-work... way preliminary to verification.) ... and then go to any reputable earth science seminar/class/whatever and present a paper on earth's shape according to length contraction, with 1/8th its spherical diameter. (Don't take it personally if you are boo-d out of the auditorium.) This is getting tedious.

swansont: (my bold)Well, you could ask a thousand scientists what earth's shape is without mentioning the unverified thought experiments on large scale length contraction and see how many say "nearly spherical" and how many say, "squished nearly flat" (or "a very oblate spheroid.") You will probably get a consensus of all 1000 that it is the former, not the latter. But, of course, consensus doesn't make it true, like a flat earth was not true, though commonly believed to be so. So I will go with disclaiming the bold above as contrasted with a mountain of empirical, objective observations and measurements which conclude it is nearly spherical, to a very high degree of measurement precision. (It's hard to believe that, in a science forum, I am challenged to verify earth's very well known shape to scientists who believe that squished nearly flat is just as valid!... based on an experimentally unverified thought experiment.)

But you keep claiming that earth IS an oblate spheroid (with 1/8th its spherical diameter) for the high speed travelers,... as seen from a near 'C' fly by frame of reference. The contradiction I keep hammering on is that earth can not BE both nearly spherical and severely oblate. It is, in the real world (see philosophy of realism), one or the other but not both. Earth science has determined that it is,in fact, nearly spherical. Length contraction of earth's diameter as seen from above frame of reference has never been experimentally verified and remains a "thought experiment." Yet you (and relativity) insist that both shapes are equally valid. Nonsense. Would you please address objection. This, of course, belongs in the "frame of reference" thread... but... First, you have not replied to any of my comments in post 260. For openers you said (my bold): Then you assert a basic non-Euclidean assumption as if it's a fact. (With no reply to my criticism of non-Euclidean geometry.) I said: No reply. Rather a link to the well known Wiki info on great circles. So Euclidean is the "wrong geometry" with no discussion. You “have to?” Not if one contests the existence of curved spacetime, like my sources in the Ontology of spacetime thread. Anyway “flat” is a misnomer for Euclidean 3-D space.(Invented by non-Euclideans.) Flat describes a plane. The space in which cosmic bodies interact gravitationally is not a “flat” plane but a 3-D cosmos. Add time if you want for movement, but it is not a “dimension” unless elapsed time for event duration is to be called a dimension.

swansont: First, I advocate objective realism, not “objective idealism” (which is an oxymoron.) I advocate an at rest (with what is measured) frame because it yields a description of earth, for instance, that does not champion the obvious absurdity, defying all known earth science, that it is "in reality" squished nearly flat as seen from the extreme FOR we have been using as an example. If the result is totally absurd (and we all know better), the assumption (no preferred frame... as seen passing by at near lightspeed is equally accurate)) is probably wrong. And no experiments have shown large scale length contraction to be valid. Agreed. But light has momentum that acts like mass (making lasers recoil, "solar wind" (?), increased inertia in the "box of mirrors" experiment...) So mass can bend the path of light without making something out of nothing, i.e., "curved space." You could also say that planets orbit the sun in straight lines through curved space... but who believes that planets' orbits are straight lines unless straight=curved (in the spacetime "model") and the words are meaningless? Yes. But ontology examines the leap from models to that which they are modeling. etc... etc... See my last sentence above and my recent ontology of space and time. No need for endless repetition if you have no interest in or knowledge of what ontology is. If you could muster the interest, you could examine your above assertion in light of all quotes in the Ontology of Spacetime thread, and all referenced material not quoted. If space is empty volume and time is event duration ("tick, tick")... then "they" do not combine into the famous "fabric of spacetime," and nothing "curves" but the model.

I’ve been arguing that length contraction has not been demonstrated on macro scale like the flattened earth scenario, which is not correct by all accounts of earth science at rest with earth. (Is "proper shape" a relevant distinction here?) Maybe I misspoke about GR vs SR, but I don't know where. I have often said that almost all GR explanations begin with some version of "mass curves spacetime." Also, I have often acknowledged that lightspeed is invariant through space, as per SR. However the philosophy of objective realism demands that distances between astronomical bodies does not contract or expand with perspective (FOR) from which they are measured, which would be a form of idealism... that there are no intrinsic, objective properties of objects, so then reality depends totally on how things are seen. Obviously there is a conflict between SR and the above realism. I do not know the solution. (As I said, still struggling with it, because I know that earth is not nearly flattened, for instance.) swansont: So when they say mass curves spacetime they mean it curves a coordinate system, a map? What curves in the real world... is the ontological question, which has not yet been addressed. On a flat map (plane) the shortest distance between two points IS in fact a straight line between them. (Maybe you just misspoke?) On a globe the *actual* shortest distance between two points is still a straight line *through the globe*, while the surface distance between them must, of course, follow the spherical curvature. me: (The "you" was, I think, addressed to Cap 'n R) Swansont: I'm not a particle accelerator specialist in atomic physics, so I'll grant the above... that the "end points" ergo distances between the particles can be measured precisely. But that leaves large scale length contraction unconfirmed, and my point above unaddressed here. As above, what empirical evidence is there for large scale length contraction? None so far. And there is a huge body of "physical tests" in earth science confirming earth as nearly spherical, but none confirming it as severely oblate, as length contraction from an extreme FOR claims. I said: You replied: To my, "What shape is earth?' then depends on how you look at it, as if it had no shape of its own... just like idealism,"... you answer, "It says that the answer you get (to 'what shape is earth?') will depend on the frame of reference you are in. ... so it DOES depend on how you look at it, which is idealism, denying realism. Also from a previous post, you asked: To be perfectly clear, again, the ontology as I see it is that time is simply the event duration of physical processes. I agree that "time passes"... that "elapsed time" is meaningful without granting time the ontological status of something that expands or dilates. Events require a longer or shorter time/duration to happen. Likewise, I contend that space is simply the volume in which things (actual entities) exist. Space and the elapsed time required for things to move through space do not, ontologically constitute a curved 'whatever,' as is constantly the claim of GR for spacetime. Finally re: First, a coordinate system is a map. It exists in the abstract or as a 3-D model to describe real stuff that exists in the real world, where things exist and move in relation to each other and "time passes" as things move around. (Again, the map is not the territory.) The point of departure for non-Euclidian geometry was to deny Euclid's fifth postulate and claim that parallel lines do actually intersect if extended far enough, like into mathematical infinity. There is no referent in the real world for this claim, and lines that do intersect are not parallel lines by definition. So non-Euclidean geometry got off to a nonsense/bogus start... and never came back. Then the intrinsic vs extrinsic curvature relative to different “manifolds” was conceived to create curved space, where previously space was simply three dimensional volume, i.e., nothing to curve. They even invented four dimensional space (not including time.) That must exist only in their minds, because there is no extra spatial dimension conceivable after 3-D volume. Hope this answers your existential question.

Amatfaal, I could not find the references from many years ago (maybe more like 10 than 5), but here is what I did find plus a final commentary, my own in summary of the missing references. Scientific American Troubled Probe Upholds Einstein, May 10, 2011 (but there is a minority opinion) PhysForum Science; Hai-Long Zhao's Mass Variance SR Theory: (Note: Just a criticism of a basic assumption of the experiment... another possible source of error.)) CNNTech; (standard version of frame dragging verification with my bold and** on the assumed established fact of space and spacetime as a malleable "fabric"... made of what?): So here we again have the ubiquitous "elastic (often rubber) sheet" asserted with no thought to or concern about addressing the ontology of what this fabric actually is in the real cosmos. Wikipedia on Frame dragging: If ‘spacetime' turns out to be a “metric”(just a map) without an ontological referent, as per the decade of ontological study by the ISASS, then another explanation will be required. Since I can not find the alternative, topographical/density variation explanation I studied many years ago, I will explain it the best I can from memory. The “Newtonian mechanics” referenced above “depends only on its mass, not on its rotation”... so it is supposed. But the mass of earth attracting satellites like the above famous “probes” is not a steady pull on the satellites. It varies with the proximity of the probes to high mountain ranges and higher/lower densities of the crust ‘sweeping by’ under their orbit. So the variations attributed to a warped but theoretical medium, “spacetime” could be attributed to such variations in gravitational pull as surface variations pass by the probes. Ps: If I do find my original references, I will share them. Meanwhile I would welcome an explanation of why sweeping differences in earth's gravity can not explain 'frame dragging' just as well as an unexplained and controversial concept, 'spacetime', with a twist.

Schrodinger’s hat: "Space is four dimensional" requires the following distinction: 3-D space plus time or 4-D space? I think you mean the former, so... My premise is that space is empty volume (except, of course, where occupied by objects) with three dimensions, and that time is event duration as objects move through space. Neither is a thing, and combining them into ‘spacetime’ still does not make spacetime a malleable medium which is curved by mass/energy. That s what the ontological debate is about. If you want to call my above premises faulty, it behooves you to show how so. If you say (or anyone says) that reality is dependent on frames of reference, you throw philosophical realism out and subscribe to a form of idealism in which things ARE as they are seen, having no intrinsic properties of their own, independent of frames of reference. The rest is window dressing, including the claim that a severely oblate earth is just as accurate/real as the “proper” nearly spherical shape that is so well documented that we can confidently teach our children that it is not, in fact, squished nearly flat.

Imatfaal: That was a 'not on hand immediately', with an "if you insist" I will dig it up. Ok, you insist. Please be patient. I studied it at least five years ago. Huh? A "lack of disinterest" is interest, not "uninterest." To simplify, again, swansont said that he is not interested in ontology, which this thread is about... like, yet again, "what IS spacetime"... the inquiry/criticism quoted and commented upon in this thread. Cap 'n R: Asserting that an argument is "incorrect" does not make it incorrect. That would require showing how it is incorrect.

Math requires referents in the “real world” to be meaningful. (2+2=4, but what the numbers stand for introduces ontology. 2 apples plus 2 oranges = 4 fruits, actual but different entities.) So the math plus the referents equals a meaningful statement. I have quoted Kelley Ross in this thread on that point, including what “intrinsic vs extrinsic curvature” applied to different “manifoldes” means in the real world, what a fourth spatial dimension might mean (or not), etc.... what spacetime IS, if anything besides a coordinate system for things traveling through space over time. A superior attitude based on math expertise does not address the ontology of space, time or spacetime. This point seems to totally elude you.

It was quite a few years ago that I researched the alternative explanation (above) to frame dragging as a "twist" in the supposed* malleable medium, "spacetime." I'll have to go back and dig it up again if you insist... after the weekend. *Meanwhile, I have cited a few experts in this thread who are very critical of the usual assumptions about spacetime as a malleable medium. (Also see my reply today in the ontology of time thread.) Swansont has said that he has no interest in ontology. That qualifies as a bias against the subject matter of this thread. I called him on that bias... not a personal "slur."

This challenge makes no sense to me. Par for the course in our history of almost perfect lack of communication. I was replying to swansont's challenge to substantiate what he thought (I think) was a claim that an at rest frame of reference was in some way an absolute reference point. I explained that I made no such claim. I gave examples of how a frame at rest with what is measured is preferable to extreme frames of reference for measuring earth's size and shape, and examining micro-organisms in a lab, etc... like zipping by at near 'C' vs under a microscope. I also said that GPS clocks have different velocities (and tick at different rates) than earth-surface clocks, which require adjustments for positioning accuracy. Your continuing attempts to distort what I say will continue to fail, but I will not continue to reply.

Regarding "pretending s means something else..." Yes, I suggested here awhile back that that the equations use "mm" for mystery medium rather than asserting spacetime as an entity, a "malleable medium." (But "mm" could then be mistaken for the latter. Better use "w" for "whatever.") I have not been arguing with relativity's predictions but rather with its attribution of substance, or whatever, to some medium (spacetime) that gets curved by mass/energy. That is the ontological issue. If "it" is just a coordinate system for tracking and predicting stuff moving through space (which can remain empty volume) over time (event duration as objects move from A to B)... then *what gets warped*? The above is the map, not the territory. What do you see as the fallacy/error in my hypotheses you just quoted above? What about the volume (space) in which things exist and move and the time it takes them to move make "spacetime" curve under the influence of mass/energy? Brown and Pooley's paper (see my spacetime thread, "Minkowski's spacetime: a glorious non-entity") asserts that spacetime does not exist, and that all predictions of relativity are based on the interactions among these masses, with "spacetime" being "parasitic" upon these actual entities. Einstein himself said that, without mass/energy, spacetime would not exist. So where does that leave it as something (?) that mass curves? That is the ontological question. I account for "time dilation" by defining time as event duration of physical processes (EDPP) and then sticking to the empirical, observed processes in question, like the variable rate of ticking in clocks, not assuming that "time itself" (what is that?) slows down. I am still struggling with length contraction, especially since you cited references indicating that optical distortion is not an option. (I will need to study the "proof" of that in depth before I accept it as factual.) Also, since DrRocket pointed out that there is no experimental verification of large scale length contraction beyond the sub-atomic level, (particle physics is very complex with lots of room for error) it still seems to me that the "burden of proof" for rods and earth and astronomical distances "contracting" is still on those who claim there is such evidence, as you seem to do. So far the best I can do is appeal to realism vs the version of idealism that claims that the description of rigid/solid objects depends on frame of reference, leaving "intrinsic properties of objects" (as in realism) in the dust in favor of frames of reference defining all objects' shapes and measures. So, the question "What shape is earth?' then depends on how you look at it, as if it had no shape of its own... just like idealism, which I find an absurd philosophy. I think that relativity claims that we can not know the shape of earth (or the "actual distance") to the sun, and that this makes a mockery of science. For all of the above reasons, I think philosophy of science is very relevant to the epistemology of what we know and how we know it. swansont: See above... also way above, like, read the thread. You criticize me for lots of repetition and then you ask this question, which I have answered dozens of times. I again defined time above (EDPP.) In what sense do you think EDPP exists as something that "dilates." How is "clocks tick more slowly..." not a sufficient description? I have posted a lot (in the spacetime thread) on the ontology of non-euclidean geometry, which claims reality for various conceptual "manifolds" and attributes "curvature" to "spacetime" in the process. For me, space remains 3-D volume, which is empty space in between (and within) *things* which occupy space. So, with the above as background, there is nothing to be curved. There is no combining event duration (elapsed time, not a "thing") with empty volume (not a "thing") which establishes spacetime as "whatever" with curvature. "Ruts or grooves" in what guide objects in their curved paths. But that is ontology, which does not interest you.

(I'm wishing that all three of my ontology threads were in one, since time, spacetime, and the philosophy of realism vs idealism... or frame of reference based "Reality", if you prefer, are so intertwined.) Since I, and many others (ISASS, in spacetime thread) do not accept "spacetime" as a given, as in relativity, using the word as an established fact is not appropriate for a discussion which disputes "spacetime intervals." It assumes a premise in dispute. If space is 3-D volume and time is event duration of physical processes (not an entity woven together with 'space'), as is my argument,... and if objects have intrinsic, objective properties (realism), independent of how they are seen from different perspectives (also my argument), then solid rods and the quite rigid earth and most other objects do not vary in shape and length with whatever perspective from which they are observed. Interrupted, tho not finished. Back later.

swansont: Cap ‘n R; post 108: (my bold) In the earth- of- different- shapes debate (as seen from different frames of reference), he also said that it’s not about earth changing shape but rather that it IS different shapes in different frames of reference. Still, it can't be both spherical and severely oblate, as an object with intrinsic properties. It must be one or the other. Maybe you guys should talk it over. Btw; Just to check my understanding of Minkowski"s four dimensions (forgetting spacetime as a malleable medium for the moment), is it not simply three spatial dimensions (line, plane, and volume) and time, which adds the dynamic of objects moving through 3-d space over time i.e., not a static 3-D universe?

How does this square with the fact that a meter rod can not be both 100 cm and 12.5 cm, the latter as seen from high speed frame of reference?

swansont: How, again, did you explain what made my argument fallacious? By citing the usual success stories of GR and saying, "GR does."? It was the ontology of spacetime being curved by mass and energy that I was questioning. Is it as mental matrix, a spatiotemporal coordinate system of math/geometry model only being warped or some medium without which masses can not pull on other masses. I don't think you know what ontology is yet. At least you have no interest in it as you said: And since that is what this thread is about... ??? Specifically what non-ontological points?... or do you not do specifics? 'GR says so' is not specific. And "frame dragging" (for just one instance from your list) is not a confirmation of malleable spacetime, as I specifically argued above... But, as usual, no reply to specific arguments. You have not replied to any of the quotes in this thread which actually criticize the usual assumptions in the relativity community about the nature of spacetime. I wish I could appeal to a moderator about all of the above, but you are it, and you are not an unbiased, objective scientist in this field of inquiry.

Thanks for the clarification. So, optical distortion is out. That leaves me with the following logic. (Epistemology includes logic as part of how we know what we think we know.) If a meter rod is immutable (in this context, like earth's shape doesn't change a lot) then it can not be both one ten millionth of earth's surface distance from equator to pole (through Paris), as derived, and also an eighth of that length, as we have discussed. It may "look" like the latter but it can not be both 100 centimeters and 12.5 centimeters. Tell me if you can, the fault in this logic.

I am trying to avoid constant repetition here. EVERYTHING IS MOVING, everywhere. So, we must define our 'universe of discourse', our focus in each case. If we want to measure a certain object, it is best to minimize variables for maximum control of one them, as in any experiment. (I started my higher education with a B.S. degree and understand the scientific method.) Flying by an object at near light speed and trying to measure it (if we even could) would not minimize those variables. It would complicate the hell out of the experimental results, if there were such an experiment, which there is not... yet. So here we have thought experiments from extreme frames as alternatives to up close examination of what is being measured. (Like the 'thought experiment' measuring the distance and travel time between sun and earth from a "photon's frame of reference." Bad idea. I think it was asserted here that "for a photon" there is no distance between sun and earth and no travel time. Then someone said... (paraphrased), no, that's not an inertial frame. Oh well, just an illustration of what an extreme frame of reference "sees.") If the frame is very close to at rest with earth, for instance, as in orbit or on the surface using various measurement techniques, this will eliminate the possible (probable, I think) introduction of error due to perhaps unknown variables involved in a super high speed frame relative to earth. The measurement of earth (and its shape) would not be done, for instance, from galactic center or from Andromeda with an expectation to minimize all unknown variables. If I may not say that this is obvious, please explain how "all thiings being equal" (variable control) applies in the situations above. There is no absolute "at rest", to answer your question. There is only relatively at rest... with whatever is the object of investigation/measurement. And there are preferred frames of reference which minimize unknown variables. I can give many examples. If you are examining the properties of a microscopic organism, for example, you want it under an electron microscope on your lab bench, not flying through the lab at near 'C.' I hope you get my point without further elaboration.

TAR: If event duration of physical processes is "something", then I agree. It "takes time" for things to move, and everything moves. Distance is the space between things, but that doesn't make the space into "something" just because we can apply numbers and distance units to how far apart things are. I agree. Clocks slow down... for many reasons. Other physical processes slow down too... probably including the aging process in humans at high velocities. When two objects get closer together, there is a shorter distance between them (to state the obvious.) Seeing an immutable meter rod as 1/8th of a meter long would be an optical distortion due to extremely high velocity. In the GPS clocks' case (in orbit), as I've been saying, it is traveling at higher velocity relative to earth's center than clocks on the surface, so the slowing down effect requires sophisticated adjustments for positioning accuracy in "real time," i.e., the same actual moment (now) for both sets of clocks. Relativity provides the equations, which work extremely well. (I don't know how much gravity has to do with the difference, but that is another question.)