owl

TAR: Yes, of course, but the Cap 'n says that earth IS squished this way from one perspective and that way from another... not just "appears" but "is",... See the lead quote in my last post. Same principle with the Doppler sound effect. We all know that a race car's engine is not revving to a higher RPM as it approaches and slowing to lower rev after it passes, but it certainly sounds that way from the trackside observer's frame of reference! Are the high rev and low rev equally accurate perceptions/measurements as the one shown holding steady on the car's tachometer, the engine's "actual" RPM indicator? Of course not.

TAR2: Presentism recognizes that the word IS needs no relativity discalimers about "my now" vs the "universe's now"... that "the present" is omnipresent, without local "nows" fro each supposed "time environment." If you understand my definition of time as Event Duration for Physical Processes (EDPP), the explanation is mush easier. Every physical process (everywhere) has a duration between one designated "now" and another, between the clicks of a stopwatch held by the measurer, or "all by itself" like one complete revolution of earth, or one complete orbit. Time=event duration, whether or not a specific event, as above, is selected and measured. Now, the present, on the other hand, has no duration. All that is, IS, right now, this instant (forget about the time it takes to say it), everywhere. Light traveling from one place to another is an event that takes time... in all cases. Time is not a thing or an environment, as misrepresented in the phrase, "time dilation," for instance, in which something is thought to expand "from the frame of reference" of one point of view or another. Clocks just tick faster or slower for many reasons, including changes in speed or gravitational fields. The above is time ontology, not just repetition of the relativity concept of time dilation as a proven given. Yes, some muons live longer and travel further than others, without morphing either time or distance traveled.

I'd better just stick to the philosophy intended in the thread title. Awhile back in this thread, Cap 'n R summed up the relativity notion of variability of what IS as tied to variability of frame of reference (pertaining to earth) as follows: (My emphasis.) Definition of philosophical realism from Wikipedia: (Again, my emphasis.) So when anyone (including relativity theorists) asserts that earth IS an extremely flattened oblate spheroid (say with diameter 1/8 the earth science measures given in my post of yesterday)... "for the high speed traveler" or "in his frame of reference"... this certainly qualifies as subjective idealism*, in that the claim is that the earth IS as he sees it, and there is no "objective earth" as it IS independent of perception. *... with "frame of reference" substituted for "subjective" regardless of the presence of a personal observer. This is probably enough said on the subject.

Cap ‘n R; Of course I am. In keeping with the argument that the closer the observation platform (closest being at rest with the object of observation), the more accurate the measure... the more true to the objective properties of the object observed. (Assuming, of course that the object observed has objective existence and properties independent of exotic frames of reference from which it is seen.) I’m still not clear where you are on the above “objective world” vs the subjective (frame of reference) perception as "reality." What do you mean by deterministic? There is a lot of debate on what that means. Different “viewpoints” as equally valid descriptions of what is seen is the essence of subjective idealism (denying "objective reality.") You seem to subscribe to the above, as a follower and well educated scholar of relativity in all respects, including length contraction. “For the muons” the distance through the atmosphere is shorter (length contracted) than the 200 miles of atmosphere which science says is its depth/thickness...? More of the magic/dogma of relativity?... which grants equality to all frames of reference and ignores what we know about the world/universe, as cited in the earth science above. (Relativity dogma: "There are no preferred frames of reference."... sounds like an "article of faith!", not science.) “For a photon” ...( like “for a muon”... thinner, contracted atmosphere)... there is no distance or travel time between earth and sun. What are you going to believe? Think it over again in philosophical context. Are you a subjective idealist? I don’t believe either scenario... " for a muon” or” for a photon” as legitimate and accurate views (frames of reference) of those distances. The atmosphere stays about 200 miles thick and the distance between sun and earth stays about the average upon which "one AU” or 93 million miles is based... not 1/8 of it, etc. "for a high speed traveler." The atmosphere of earth is not thinner to accommodate "length contraction" theory for incoming muons. "All frames of reference are equal" is subjective idealism. Put on your philosophy of science "hat" for a moment, setting aside relativity dogma (as I see it, of course, in this case), and speak to the topic here presented... please.

Cap 'n R: Isn't "the statue" the earth in this case, about which we know a lot, from all 'angles' and from a lot of scientific examination, as you acknowledge above? And if it appears distorted as in the high speed fly-by (which I do not doubt it would), why then do we not accept the "objective earth" as known through earth science as its actual shape** and call the former perspective a "distortion" of the image of earth due to the near 'C' relativity effect? Then we avoid the subjective idealism absurdity of claiming, in general, that all perceptions (frames of reference) equally and accurately describe earth, and there is no "actual, objective earth" (as it is independent of various perspectives.) Correct me if I am wrong, but they find that naturally occurring muons traveling through the atmosphere have a much longer "lifespan" than lab muons in a particle accelerator. The assumption here is that the lifespan is a given, referencing lab muons, so they must be traveling a shorter (contracted) distance through the 200 or so miles thick atmosphere. How do lab muons get to be the standard lifespan in the first place? Second, how does the atmosphere get thinner (contracted distance of travel) around muons? I don't deny what it does well, only its assumptions about length contraction and time dilation (and of course, "spacetime" as a very mysterious malleable medium.) ** www.universetoday.com/15055/diameter-of-earth/ - CachedSimilar Wikipedia: (Earth, Shape section.)

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?

Cap ‘n R: (have a given shape... nearly spherical "all by itself,” as an objective object.) So you continue to deny what earth science knows about earth’s shape in favor of calculations and resulting appearances based on Lorentz contraction applied to large scale objects, which has no experimental evidence to support it. It is subjective to deny the well known and scientifically validated shape of earth and claim that a squished earth is equally valid “for the high speed observer,” where frame of reference substitutes for subjective perception as “reality” in subjective idealism. I thought we were making progress in mutual understanding via “transforming” what the high speed observer would see, by a precise relativity formula, into what shape earth actually is in the objective universe (nearly spherical), thereby translating or adjusting the “appearance” of earth at high speed into the actual, factual earth known to earth science, thereby ending up “on the same page.” But you continue to deny that there is an objective earth with spherical shape, which makes relativity (specifically length contraction) sound like dogma in denial of facts. swansont: Since “that experiment has not been done,” you have no evidence that there is such distortion. Tell me how I am wrong here, but you seem to have the burden of proof for large scale length contraction exactly backwards. Further, if it turned out that there was such distortion (say, showing a meter rod one eight of a meter long or an earth diameter contracted by a factor of 8), the operative word here remains “distortion.” Neither the meter rod not the earth would actually shrink, unless you think perception/appearance in this case creates an alternative “reality”, as in subjective idealism. me: you: Huh? I reasonably assume that earth has had nearly the same shape (not shifting with various perceptions of it) since long before either spaceflight or relativity theory. Did you not understand that, or are you intentionally “distorting” my meaning?

Cap ‘n R: But they don’t co-relate deeply enough to recognize that earth has* a given shape (nearly spherical) all by itself ("an objective earth"), independent of frames of reference from which it is seen (*and has had long before relativistic frames of reference were even thought of.) I meant no offense to you personally. My previous comments about time dilation and length contraction as relativity dogma ignoring reasonable intelligence and common scientific knowledge (shape of earth and length of a meter rod for instance)... was met with harsh criticism here by the one that seems to do most of the warning and banning, insulting me and intimidating of anyone who agrees with me and criticizes the mainstream opinion. swansont: From my post 36 above:

So the issue is about what it looks like (from various frames) compared to what it is, "objectively" independent of the variety of perspectives from which it is seen... as per philosophical realism, my argument. You started with:"Earth science has thoroughly established Earth as nearly spherical." Then you added the philosophical disclaimer (which sounds very much like subjective idealism,) "in our frame of reference" with the relativistic understanding that "all frames of reference are equally valid" (not quoting you but true to relativity theory.) If all frames of reference are equally valid then relativity theory is philosophically identical with subjective idealism. And we can ignore all the evidence to the contrary about what we KNOW about earth's shape and size, and give the earth a squished shape ("equally valid") and 'worship at the altar of relativity theory.' (Who would question Einstein and his disciples? I will, for one.) Hopefully you will not vilify (and ban) me for the above heresy (between the half quotes.)

So, back to subjective idealism, it claims that there is no "objective universe" because each person sees things differently, and that is "reality" for each individual, and, further, there is no way to know what is "real" besides subjective perception. If we substitute frame of reference for person (or subject) above we get the title of this thread. If you insist that a squished earth describes "reality" on equal basis with a spherical earth, because the math of relativity says so (which you can calculate and I can't), then there is no description of earth "as it is" (philosophy of realism), but rather all frames of reference... individual perspectives/perceptions (and descriptions of the world) are equally valid. I had thought the "transformation" principle was going to reconcile the above, given your disclaimer that length contraction is not a form of subjective idealism. But the fact that earth science has thoroughly established earth as nearly spherical ever since we got over the flat earth mis-perception does not dissuade you from claiming equal reality quotient for a squished earth. So we are back to frame of reference as subjective idealism.

Now we are making progress in communication. I have often/repeatedly credited relativity with the above, which is why I am not about debunking relativity in general. Yes, its formulae keep us all on the same page for accurate GPS positioning too, even while relativity effects make clocks go bonkers. Likewise we can take the squished earth as seen from high velocity, apply the Lorenz transformation formula and transform the squished earth back to its "actual" shape in the real/objective world... Right? (Or is the squished earth still just as real as the spherical one, as a subjective idealist on the spaceship would say?) I'm betting you say "wrong," and continue to insist that the squished earth is just as accurate a description as the spherical one we all know and love!

From my post 24 in the Frame of reference (philosophy) thread; The question went unanswered, but it belongs here:

Cap ;n R: Well, hypothetical fairies could outnumber humans too, depending on who is imagining them. (But this is tongue in cheek; I do get your point.) But seriously...This thread is offered as philosophy of science and focused on relativity’s “frame of reference” as very much like the “subject” in subjective idealism. The latter claims that there is no “objective reality,” but rather that whatever anyone perceives *is reality* "for him." The “for him” is like the “for a photon” frame of reference (there is no distance between earth and sun or travel time) or “for the above high speed scientists,” earth is an oblate spheroid. Philosophical realism, on the other hand, claims that earth is as it is independent of subjective or extreme frame of reference perception... that the many possible variations in how it appears are due to perceptual variation rather than earth itself varying in shape, etc. That, of course still leaves the question, “What is its actual, objective shape (and size?)" If you claim that we can not know that because of perceptual and frame of reference variation (with “no preferred frame of reference) then we can say, as above, that the flat earth perception (a local "frame" not about relativistic effects, of course) is just as accurate as the spherical earth later confirmed by science,... but now again debunked (?) by the oblate spheroid earth as seen from near ‘C’ perspective... and there is no “objective reality/cosmos”, cuz it all depends on perception. This puts relativity’s length contraction squarely in the camp of subjective idealism. If you say, “OK, so what?”, I’ll just rest my case, and accept that relativity theorists believe that science can never know the actual properties (shape, size, etc.) of earth, let alone anything else, like the “actual length” of a meter rod. I'll repeat that it seems reasonable to assume that the at rest frame with what is perceived/measured will yield the accurate measurement/description, not the frame flying by at near light speed (or the imaginary earth flying by a stationary point at near 'C'.)

What a kidder! Frame of reference defines reality. Flat earth?... A legitimate frame of reference, empirical, reporting what is seen. Only it isn't flat, it turns out. Oblate spheroid earth?... A legitimate frame of reference, etc., as above. But you must be flying by at near 'C' to "see" it that way. (Or have your head in the sand... something unusual at least... the lighter side!) Only it always stays nearly spherical according to all other perspectives, both post renaissance and modern, so why does the imaginary space cadet get credit for equality of measurement? Are flat earth'ers due equal credit?... or has science shown them wrong? (Grammar edit.)

Do you think there is any way to reconcile your imaginary high speed scientists' view of earth with the centuries of knowledge about the spherical earth since early inhabitants thought it was flat? Of course the latter were only reporting what they "saw" from local surface observation as a "frame of reference" like your imaginary high speed voyagers.

md65536: Everything everywhere IS happening NOW, simultaneously. That is the version of presentism with which I agree. The focus of relativity is always on, as I’ve said repeatedly, “Who (frame of reference) sees what and when.” This obviously depends on the light speed limit as conveyor of images and information (signal delay.)But the "objective universe," as it is, does not depend on how and when we see what. This is philosophical realism as contrasted with subjective idealism where frame of reference is substituted for subject. (See my thread in Philosophy.) So, as above, presentism doesn’t deny that it takes time for light to travel and convey info. The event duration for such travel of light from sun to earth is 8+ minutes, so when we see a given solar flair, for instance, we know that it actually happened 8 minutes ago. But this is not to deny that now is the present both here an on the sun... and throughout the universe.

swansont: I agree with the first statement. That is why I started this thread... to illustrate how similar relativity’s insistence that reality depends on frame of reference is to subjective idealism’s insistence that reality depends on subjective perception. The alternative philosophy is realism. Wikipedia on Philosophical Realism: Wikipedia on Objectivity as a philosophy: My argument is that the closer the measurer is to an at rest frame with what is measured, the more accurate the measure ( description of shape of the body, etc.) I thought that I had answered the challenge of your last statement repeatedly. How we know what we know (epistemology) about the size and shape of earth and its distance from the sun comes from more sources than just comparing the extreme, near ‘C’ frame of reference to the at rest frame and claiming they yield equally correct measurements... because relativity claims that everything (reality) is always relative to frame of reference Again, we know that if earth were "objectively" only 12 million miles from the sun it would be incinerated. Saying that “for the high speed traveler,”. the sun is cooler,(or whatever) is subjective idealism. .. that his perception creates an alternative reality... But his perception does not make the sun cooler, or the distance between the two bodies shorter than the standard AU measured from earth, at rest at one end point of the measured distance. Likewise we know from the whole field of earth science that it is a relatively rigid and nearly spherical body. So, to claim that the long belabored extreme frame of reference (likened here to subjective perception/idealism) seeing it as an oblate spheroid is just as accurate as its shape and diameter well known from multiple earth science sources... shows that the near ‘C’ fly-by frame yields a distorted perception and measurement. What objective tests? The orbit of satellites would be radically different if earth were an oblate spheroid. The view of earth from the space station would not see a round (spherical) earth if the extreme frame were an accurate description. Mechanically, we know that earth does not actually flatten out, because we know it is a semi-rigid body. The surface survey which yielded the standardized, earth commensurate meter would have found a different length if earth had a way longer axis length than girth through the equator, or vice-versa. How many more objective tests would it take to establish the “true shape and size” of our planet?

swansont: I’ll just focus on the distorted earth example, which also applies to an extremely shortened astronomical unit.* But first, regarding your “explanation”: * So, “for the near ‘C’ traveler,” whizzing by makes the sun cooler “for him?” This is an explanation? We don’t need a test to “know” (philosophy of science, a-priori epistemology section) that earth does not in fact turn into an oblate spheroid... ever... (ignoring the trivial bulging at the equator from eons of spinning.) So, if an extreme frame of reference (not at rest with earth) “sees” earth as such, that is an error of perception/measurement. It is just that simple, although it does require the application of common sense and acknowledgment of the obvious...i.e., that earth stays nearly spherical even while being seen and measured from near 'C' frames of reference. DrRocket: The ontology of spacetime is still a hot debate, not a cut and dried established entity as you seem to think (and relativity assumes). I suggest you read my comments and links in my thread on the subject, Spacetime Ontology: the Scholarly Debate, here in the Philosophy section. The pseudo-Riemannian manifolds belong to a specific ontological debate, the background of which I have frequently cited in the Kelly Ross paper on the Ontology and Cosmology of Non-Euclidean Geometry. See also* how math figures into the ontology and meaning of what exists in the real world; and math does not establish what is an actual entity or the meaning of relationships between them. *(Recently quoted above in reply to Cap ‘n R ... that the math is not the meaning, nor does it establish the existence of non-Euclidean manifolds.) Ps re swansont's: I have repeated, over and over, redundantly speaking, that I am not trying to debunk relativity in general. I have repeatedly acknowledged that relativity does a great job of taking into account effects like the fact that clocks tick more slowly at high speed and altered gravitational fields, and so adjustments in GPS clocks can be made to insure accuracy of positioning. Pointing out the absurdity of believing that: seeing/measuring earth as morphed into an oblate spheroid is just as accurate as seeing it as nearly spherical... is not "like bringing a nerf knife to a gun fight," though believing the latter is absurd. (Very slow page changes... my signal/computer or the site, I'm wondering? Also wishing a new, later post would show as a new post in this case, cuz this one is intended to lighten up the discussion while staying true to my argument.) Pop quiz, True or False: A: Appearances can be deceiving. B:Earth appearing as an oblate spheroid (from high speed frame of reference) is a case of the above. C: Clocks ticking at different rates in orbit than on the surface means that relativity is true in all respects including time dilation and length contraction.

Tar, Seems you went the long way around to get to the core question: "What is "it" that is changing?" What is changing is the rate of clocks' ticking, the Event Duration of Physical Process in this case. There is no 'thing, time' changing.

swansont: Earth is at rest at one end point of the earth-sun distance. A near ‘C’ frame of reference flying past earth and sun and getting, say, the 1/8 AU measure of that distance, as discussed at length with Cap ‘n R, is not obviously an at rest frame, and “sees” the well established (from at rest frame) length as eight times shorter. If the sun were in fact only 12 million miles away (rather than the 93 million established from the at rest frame) earth would be incinerated, as I argued earlier, with no coherent rebuttal offered. Do you have one now? And I still can’t believe than any intelligent person believes, in the often considered “two rods of equal length” scenario, that making one go fast makes it shorter, and then it gets longer again, equal to its “twin’s” length when it is brought back to the at rest frame side by side. The “objective” length of the two identical rods stays the same even though the extreme frame change above makes one appear shorter. I think that soon, the scientific community will look back on the above “length contraction” examples and chuckle at the absurdity which places near light speed frame of reference measurements on equal footing (equally accurate) with at rest frames... resulting in such variable distances between cosmic bodies and such variation in immutably rigid (their objective property) rods. BTW, I did a lot of homework in my last post and asked a few questions, still unanswered; and Cap ‘n R’s apparent contradiction above, which I spelled out in detail, has still not been addressed. Repeating “straw man” is not an answer or even a conversation on the topic. And the topic here is the philosophical difference between an objective* and a subjective** view of the universe, not a curtain to hide behind, as you suggest I am doing. * Existing and having properties independent of extremes from which measured, and those properties are best known when seen and measured “up close” from at rest frames. **Having no properties in and of itself independent of extreme frames of measurement. If * then earth stays spherical and never turns into an oblate spheroid... or gets 8 times closer to the sun. If **, it does. In fact, it doesn’t.

Doesn't the principle of Occam's razor just "cut out" stuff in theories that are not required... like for gravity to work?... I mean, since nobody knows what "it" (spacetime) is anyway? To this point, while I was trekking around the realm of "quantum gravity" I found (again) this well known support for relativity and its spacetime concept (referenced also below): What part did curved spacetime play in the above that was such an improvement over old fashioned Newtonian gravity? (A sincere question.) Would a math symbol for "mysterious medium" (MM) have worked as well for the predictive math as making spacetime a malleable medium, an entity in the ontological sense? Now to "quantum theory of gravity"... and yes, it is relevant to the topic as challenging *parts* of relativity: What do you think of this Scientific American article at: http://www.scientificamerican.com/article.cfm?id=splitting-time-from-space ? Then there is this from Physlink.com http://www.physlink.com/education/askexperts/ae620.cfm (Comments?) Most basically, how do you think Newtonian physics failed to answer the questions, "'Is the universe infinite?' or 'Is time eternal?" Seems pretty obvious to me that there can be no "end of the universe" as I've argued in threads here on that topic. ("What boundary? What on the "other side" of a proposed boundary?) And, of course, if time is the Event Duration of Physical Processes, then as long as there have been and will be physical processes (objects moving around) time remains the duration of those processes. What would an "end of time" look like? All moving objects somehow vanish? From the Ontology of Time thread: swansont; Please check thread title. This thread is here to examine the difference between a philosophy of science based on investigating an objective world/universe which exists independent of observation/measurement/frame of reference vs one in which reality (the world/universe) depends on perception of it from very different frames of reference. If the former, then it is as it is regardless of how we "see" it. Then, when we see earth as an oblate spheroid, we know that is a distortion of its true and well established shape as nearly spherical, and we have a good idea of why it is so distorted. This is a philosophical alternative to the claim that all frames yield equally valid measurements. Same with the equal length rods as compared side by side vs viewing one of them from an extreme velocity frame of reference (or bringing one rod to high velocity.) The " objectively universe" philosophy (as contrasted with relativity) says that the rods are as they are independent of extreme frames for measurement... that one does not become way shorter, as so measured, and then return to its original length when brought to rest beside its identical twin. You continue: I am not reifying time. There is no "it" to dilate or to be "woven together" with space. Our clocks simply tick more slowly at high speeds and different gravitation fields. (Often repeated.) I am not reifying space/distance. Between objects *in space* is distance, which varies with their movement relative to each other. The distances between them does not vary with every high speed frame of reference from which they are measure, according to a philosophy of an objective universe independent of measurement differences, as above. When relativity says that "for a photon" (traveling, of course, at light speed), there is no distance between earth and sun and no elapsed time for traveling that "no distance," this does not make the distance between earth and sun, in the "objective universe) zero. The claim that both measurements (one AU and zero distance) are equally correct is patently absurd. Does anyone here really believe that zero distance to sun and zero photon travel time is "equally correct" with the well established AU and the 8+ minute travel time for sunlight? Enough for now.

swansont: I will reply in my thread in philosophy on frame of reference as subject in subjective idealism, as that is where this topic belongs.

View PostCap, on 14 July 2011 - 12:12 PM, said: As I keep asking (most recently in post 23,) here phrased a bit differently, what does “spacetime” add to the observed behavior of objects under the influence of gravity? Planets orbit stars as mutually attracted by their masses. Why introduce the elusive medium spacetime and insist that gravity curves it and then planets are guided around in their orbits by spacetime rather than by the pull of gravity without an unidentified medium. Why doesn’t the principle of Occam’s razor cut spacetime out and let gravity be the attractive force of mass without the unnecessary medium/concept/whatever, spacetime?

swansont: As I asked yesterday, "Can we experimentally verify that gravity does not work without spacetime"... whatever that is supposed to be? Yet another question even without the last one answered: Is the quantum theory of gravity not an alternative to relativity's insistence that gravity curves "spacetime," which might as well be a metaphysical invention for all the debate over what it is (or not) in the "real world." Cap ‘n R: So this totally avoids the obvious reality check that earth is in fact a near spherical body (in the "objective cosmos"... my term here), not an oblate or prolate spheroid, even though it would be seen as such from various directions of very high speed frame of reference. Your insistence otherwise rejects my "objective world" argument of this thread as contrasted with the subjective perspective that all frames of reference are equally valid.

Wikipedia on reification: As you know from my threads on the ontology of time and spacetime I have often asked what it is that gets "morphed" when relativity talks about curved spacetime or dilated time (what "dilates" other than clocks ticking slower?)... or... what expands in the cosmology of "expanding space" besides the fact that things in space (empty volume, no entity) get further apart? Anyway, rather than to keep repeating myself, I took a brief net tour on reification and time dilation, and gleaned the following: From answers.yahoo.com: (Please read "primitive" as "natural", ontologically "existing in reality", not just a concept.) From the “Time Dilation” section at www.thebigview.com/spacetime/timedilation.html : (Not quite true, as seen in sub-atomic particle accelerators, but with no transference to larger scale... as discussed here in detail.) "...Time expands..." How is this NOT a reification of time. Something is seen as expanding. And you have said that it is more than just the slowing down of clocks, which means that you do reify time as an expanding (I know, you prefer "dilating") entity of some kind. (Ontology identifies a range of meanings for "entity.") swansont: Do you have a substantive rebuttal to the argument that earth does not actually flatten out under any circumstances even though it appears to do so, or are you going to keep repeating “straw man” as if that addresses the substance of my argument? And the Cap 'n still hasn't clarified the apparent contradiction cited again in my last post. If earth does not morph out of shape, then the observation which says that it appears that it does shows that appearances can be deceiving (my point about illusion in last post), which is well known in the psychology of sensation and perception as well as being a basic principle of stage "magic."