owl

To at least question authority (even the scientific mainstream) and think for yourself. Btw, this does not require being a mathematician/physicist.

You're welcome. It belongs in a philosophy curriculum but not as a basis for empirical science, as in the claim that reality depends on how it is seen from different frames of reference.

This is classical subjective idealism, as per Berkeley and Hume. As I posed in another thread, suppose no intelligent life ever evolved. Only the most extreme anthropomorphic philosophy would claim that there would be no cosmos without intelligent life observing it. Science's job is to investigate the world with the least possible bias... the maximum objectivity.

Very interesting. One of my favorite subjects. And SR has re-defined "IS."** The future has not yet happened. The past has already happened. The present IS happening this instant as future becomes past. This instant is not a "very small slice of time" as some would have it. What was Einstein thinking when he said, as above?: md65536: Me too, but for different reasons. And the above quote is contradicted by Einstein himself if Mystery111’s statement is correct: **Wikipedia on Eternalism (philosophy of time) (my bold): I agree that space (and the objects in it) are 3-D and "time" elapses as things move through space. "Spacetime" reifies both space and time, creating a model of a 4-D "block universe" in which everything that has happened or will happen "is still happening" in some sense... related to the "light cone" model of every different "event" in every different location. Also (Wiki, continued): How did the present become location specific? Via the 4-D spacetime model with light cones for each frame of reference having a different "now." The Wiki piece continues: I agree.

Here is a review of the first five pages of this thread showing the run-around I've been getting on this topic, particularly on how reality depends, in relativity, on frames of reference, i.e., that there IS no objective shape of earth, as the 'key note' example. Somewhere in the thread, also, is DrRocket's statement that there is no experimental validation of (large scale)* length contraction... a point continually avoided by its advocates. My challenge of the supposed particle accelerator validation was met with an offer to ask questions of an expert, Cap 'n R's boss, which I did, but they went unanswered. From post 16: me: Cap 'n R: From post 37: me: Cap n R; (A little humor there... but the point is clear.) From post 42: Cap ‘n R: Different FORs yield different realities. DrRocket from post 43: From swansont’s post 45: me: S: (My bold edit.) That's "is radically different", not "appears different." Cap n R, post 47 (my ** emphasis): ** This leaves the philosophical challenge of realism and objectivity unanswered. Wikipedia on Philosophical Realism: Wikipedia on Objectivity as a philosophy: I replied to post 47 in part as follows: *So I thought. Post 49: me: Cap ‘n R: (my bold.) Note: “squished earth” is just as accurate as “nearly spherical earth.” Realism? Objective, intrinsic earth. Not. Post 50: (DrRocket quoting Cap 'n R): DrRocket: But is there an objective shape of Earth or not? And if so, what is that shape? The answers do not require calculation. They are, "yes," and "very nearly spherical." Cap ‘n R: See thread title yet again. What it looks like from different frames is not disputed (much) here. (See DrRocket’s comments in post 43 above.) The question here is... Does Earth have an objective, intrinsic shape independent how it might be seen from different FORs? (Ans: Yes.) From post 57: me: Cap ‘n R: (my bold)... It doesn't have a shape "all by itself" independent of FORs. From post 62 on length contraction as seen from a muon’s FOR : Cap ‘n R: (my bold) So FOR determines how thick the atmosphere IS. From my post 65, quoting Cap ‘n R: (My** emphasis.) Definition of philosophical realism from Wikipedia: From my post 78: ... to which Cap ‘n R replied: ...”the shape IS (only) different between reference frames.” Not “appears different” but “is different.” FOR determines what shape earth IS. From my 82: The Cap ‘n replied that all of the above can be true if amended to “in (this or that) reference frame," in all cases. Reality depends on FOR... no intrinsic, objective real world. Earth's true shape can not be known. From my 86: Cap ‘n R: Not across all reference frames, no. Repeat: There is no objective, as-is shape of earth. FORs determine reality.

... Yet again: "Please cite the experimental evidence for a squished description of Earth" or any observable instances of length contraction. Is it "pretentious" of physics or Earth science (pretending to be metaphysics,) to describe what shape Earth actually is? Ps: I said: Sorry but we are clearly not done yet until you cite evidence for length contraction. And 'it looks good on paper' (the "model") is not experimental evidence.

On Sept 30, Schrodinger’s hat replied to my statement: ...as follows: Maybe focusing on one point at a time will clarify my intent in this thread. Relativity is ‘all about’ frames of reference. ... “for a muon”... “for a near lightspeed traveler,” “for various observers" with various velocities relative to (or at rest with) that which is observed. Whereas, the intrinsic reality of the world/cosmos does not depend on the frame of reference from which it is observed. But of course science is not an omniscient god with an absolute FOR, so it must find the most accurate ways to observe and describe the “real world.” The epistemology of empirical science is based on such observations, and a reasonable scientific community must decide whether, for instance, the shape of Earth is best described by observations and records from hundreds of years of earth science, i.e., nearly spherical with precise measurements of both polar and equatorial diameter... or from a theoretical, never- been- done, near lightspeed fly-by FOR, which might “see Earth” as having a diameter an eighth or so of the above. It is really very simple. According to relativity’s dictum, “There are no preferred frames of reference”, either Earth’s shape changes radically with the FOR from which it is observed or it stays the same, but we can not know what that shape, in fact, intrinsically is. We can and do know the above to a very precise degree of accuracy. The theory of length contraction has never been demonstrated aside from highly technical interpretations of particle accelerator experiments. I trust the established epistemology of what we know about Earth’s shape (not just 'my version of reality'), which is to totally reject the length contracted version of earth as having a diameter of around 1000 miles. To believe the latter, based on “no preferred frame” and a theory with no demonstrated basis in reality is nothing less than a pseudo-science version of dogmatic fanaticism. We can apply the above also to the reality of an Au as precisely measured from Earth (see again my introductory quote), to the length of a meter rod as derived from a surface quadrant of Earth and measured “at rest with the rod”, and to the thickness of Earth’s atmosphere as around 1000km, though there is obviously no fine line between atmosphere and no atmosphere. Muons do not get to determine an equally valid measure of our atmosphere’s depth/thickness, even though “for a muon” it is radically thinner. I will let my case against length contraction rest with this post. Criticisms start with assumptions about 4-D space. Here are Cap 'n R's comments on that from post three: Regarding 4-D spacetime: I have often cited Kelley Ross’ paper on the transition from Euclidean to non-Euclidean geometry and cosmology... and the *assumptions* inherent therein. http://www.friesian.com/curved-1.htm Also Brown and Pooley’s paper: Minkowski space-time: a glorious non-entity http://docs.google.com/viewer?a=v&q=cache:mq3qo9PLzlAJ:philsci-archive.pitt.edu/ See “Contents”, #4 on length contraction. Edit: An excerpt from that transcription didn't work... bad format. Please go to that section... on "a single rod assigned two different lengths..." These 4-D “cross sections” (often employed in Cap ‘n R’s “explanations) are based on an abstract coordinate system which *assumes* 4-D spacetime, which the above sources dispute. I have explained 3-D space and time-without-reification into "spacetime" many times. Cutting the above (bold) is a mental exercise. The solid rod itself stays solid regardless of what cross-sectional view of it "in 4-D spacetime" we advocate. I've got a ream of notes from different sources debating length contraction, but the above begins with the foundations in non-Euclidean geometry/cosmology and the resulting 4-D space concept. I’ll leave it there for now. *(Ref; my): I see. The way relativity works is that Earth may actually be squished nearly flat, and the rest of science (besides relativity) might just be confused about the reality, if there were one, of Earth's shape. Again, please cite the experimental evidence for a squished description of Earth. You say, "It's clear you do not want to learn from me..." But you invited me to ask questions of your boss about how the particle accelerator experiments validate length contraction... I asked a few... you gave me three links which I studied and commented upon... with no reply from you. This is called "bait and switch" in the commercial world, and it is really unworthy of a sincere scientific dialogue. Please explain the latter. Nature does avoid absurdity while physics has no such need? Regarding the former, I know. Stephen Hawking published his singularity theory of cosmic origin, saying that all cosmic material came from a "point of infinite mass density and zero volume." (Wow!... All there is originally in a point with no volume!) I criticized the obvious absurdity of this in a science forum. He gave it up... not because of me, I'm almost sure... and gave his support to the M-theory. It depends, as I've said, on "eleven dimensions." Apparently no description of them is required to make it respectable science either. Authority and popularity does not make either of the above cosmologies true. Well, I already have to some extent. How about the part where "virtual particles" come out of nothing and then quickly disappear back into nothing? 'Something out of nothing' (like in "where did it all come from before the bang?") is a cheap magicians hat trick, or pseudo-science 'sleight of mind.' And those entangled particles... how do they keep in touch "at a distance" and do the same spin reversals at the same time? Maybe the bar has been lowered for what qualifies as science. Or we do observe "action at a distance" and still can't explain it. I'll go with the latter. Same for gravity.

I wasn't asking for a mainstream, textbook account of length contraction. This forum has presented that argument extensively. My threads and sources are critical of some parts of relativity, and those criticisms have not been addressed here at all. The main theme of this thread, for instance, is that the philosophy of realism says that "the world" has a reality of its own, independent of how it is observed from various extreme frames of reference. ("Imagine no intelligent life"... etc.) How would things change if there were no observation and measurement from these extreme FORs. Not at all. So what shape is Earth? (How long is a meter rod, the Au, etc.) We don't know? Yes, we do know, and earth is not flattened like a pancake, even if it looks that way from the overworked FOR you length-contraction advocates have championed here. Is that an appeal to ridicule? That the very oblate spheroid description of earth is absurd/ridiculous is not because of me appealing to ridicule. And of course, there is no experimental evidence at all for the validity of such a description. How "reasonable" is it that Earth's atmosphere IS very much thinner "for a muon" than as measured by all our best tools of Earth science? Not at all reasonable. Again: ...and the solid meter rod "appearing" like 12 cm or so, and... TAR2: Sorry, but have found your posts lately rambling, full of tedious and irrelevant minutia/detail, bordering on incoherent, and mostly off topic. But, if you will refer me again to your "flybyguy's ricochet experiment" I will study it and reply... Btw, please explain what you mean by 4-D space.(Not just, 'everybody knows what Minkowski meant.') What fourth axis is there applying to 3-D objects and the volume of space itself. And I do recognize time as "that which elapses" as things move, i.e., not a static snapshot universe. Also time is not an entity, not an ingredient mixed with space (empty volume), becoming a mystery medium, "spacetime." Meanwhile, I'm gone again for the weekend.

Does this leave anyplace at all for reason or common sense? All I was "throwing out" was the absurdity of length contraction/time dilation as describing a very distorted solar system, all bodies like flat pancakes and all, and the distances between planets and sun up to the observer's limited FOR. Not even close to realism. I can say "please explain 4-D spacetime" with something more than a rabbit pelt metaphor (spacetime is just a metaphor for our model of space and time) "and then expect relativity to make very much sense." (some sense, anyway.)

Cap 'n R, Some review of unanswered questions and unaddressed comments before replying to your last post: From post472: In post 475 I accepted your offer: No reply to these specific questions. Instead: I looked them over and commented in post 480. Here are some unaddressed comments and unanswered questions from that post: Maybe not. Some guy, Mentallic from the forum you linked writes: I reply: From your Stanford link on SR, the second postulate: My reply: You: No comment on any of the above. Regarding Minkowski 4-D space: No comment on others’ criticism of above, ever. Just more advice to read a good textbook on it, like the mainstream combination of time and space (forget the ontology of each and both together) as per Minkowski is not to be questioned. Then, of course, there is basic realism, repeated yet again (with bold emphasis): Then again to my favorite example how things might look in extreme frames ("like pancakes") compared to all realistic descriptions: You continue to dance around this point, invoking the 4-D space device* (a coordinate system) with a “who knows?” approach, all FORs being equally valid. So maybe Earth really IS squished nearly flat! You call this science? *About the “devices” of relativity (from post 475): Again, this thread is about the philosophy of FORs as determining reality. I closed the above post with another summary, still not addressed: I'll post this and then go to your last post. "Rotating coordinates" in your "4-D" model of 'spacetime' ("rabbit pelt"... whatever,) does not not "cause" anything "mix" or rotate in the real world. The above reifies time and space. If time is the duration from one "now" to another, and space is the volume in which objects exist and move (see extensive arguments in "ontology of time" and "spacetime" threads), then "rotating (your) coordinates doesn't cause any object to move closer to or further from any other object in the real world, but only in your model. The "nature of Minkowski space" is not a factual natural phenomenon for good students to "learn" about. Rather it is a concept with a hot debate around it. You continue to ignore that and my critical references (including the B&P paper cited above and the ISASS volumes of papers)... and treat the 'mainstream' as the only 'stream' of intelligent thought on the matter. See my repeated references to the Kelley Ross paper on Non-Euclidean Geometry and Cosmology... addressing the *assumptions* inherent in modeling space as four dimensional. The three axes of volume ( space and the objects in it) fully describe them, and time remains "that which elapses" as objects move. You are welcome to show me* how you think that is wrong or how space and time coalesce into an entity in the real world. If I were an M-theorist, I could challenge you to describe those extra seven dimensions (beyond 3-D and time) upon which cosmic Membrane is based. I would settle for the *"show me" above. I would need to become an expert in that field (or get my above questions answered) to address subatomic length contraction. I will, however settle for an admission that Earth stays pretty much spherical regardless of extreme FORs, and the same for the usual suspects: The Au, Earth-Sun distance, the solid meter rod, and the depth of Earth's atmosphere do not really shrink as seen from extreme FORs. Or, in lieu of shrinkage, which you have disavowed, science can not know the true shape of Earth or the other lengths above, and all scientific epistemology has been made obsolete by SR's theory of length contraction.

Here is part of what gleaned (with my comments interjected) from your links. russ watters, physorg.com "...because of relativistic effects..." relativistic effects are demonstrated. Perfect tautology, but it explains exactly nothing. Could I translate it to something like, 'the faster a particle travels the longer it lives and the further it goes?' Last sentence in quote affirms that each frame of reference has its own reality, i.e., there is no reality (real world) transcending FOR. From I Am an Engineer (same site): "For a muon" Earth's atmosphere is much thinner than Earth science has measured it. Fine. Good thing muons don't dictate reality for all of us Earthlings. We like it around 1000km thick. DaleSpam (same site): I will need to study the meaning of "bunch length" for a hint of what this means... and why "more charged particles" can not be "squeezed into a single bunch" (like compressed) without length contraction. Maybe your boss can tell me. Mentallic (same site): Me too, like “in the real world, independent of “as seen from extreme velocity FORs." From the second link, Stanford site on SR: Light is clearly a mysterious and quite versatile and insubstantial phenomenon. No argument with the above, but that does not make distances between objects in the real world longer and shorter (expanded and contracted) with every different FOR... as subjective idealism would have it, with FOR as an abstract version of "subjective." Agreed. Physics does " not depend on our particular observing situation"... like the FOR of muons "observing" the depth of Earth's atmosphere. Cap 'n: Would you please contrast this with my repeated comments on 3-D space plus elapsed time for movement rather than space and time somehow combined? (Ref: Brown and Pooley, Minkowski’s spacetime: a glorious non-entity.) Me, personally? How about the overall philosophy of realism that the world exists and has intrinsic properties, objective shapes and relationships/distances between objects totally independent of FORs from which they are observed? "You can call me a dreamer, but I'm not the only one." (Paul McCartney.) Ps, I forgot the Feynman link: So “the effects of relativity” cause particles to look like pancakes from one frame to another. Fine. The Earth might look very squished and not at all spherical from your extreme FOR, but that does not make it so “in the real world.” It is a very real, substantial solid-ish object with a life and properties independent of how it is seen from the exstreme FOR.

Yes, thanks. How are the "end points" measured in the accelerator? And how do those measuremets confirm that the distance between them has been shortened by their respective high velocities? In other words, how does going faster make the distance traveled, or length between them shorter or contracted? Also fascinating that you refer to length contraction and time dilation as: I agree that they are "devised" for the purpose you stated. Clocks slow down at high velocity (etc.), and "time dilation" is "devised." Three D objects and the distances between them in space look different from different perspectives/velocities, and "length contraction is "devised." And they are conceptual reciprocals... expanded time=contracted space/distance. "Time and space" are taken for granted as some sort of entities... reified. (Not so, ontologically.) On the other hand, how "logically consistent" is the assumption that solid objects either change shape or their shape can not be known because of the great mystery of c and how things look from different frames of reference. Same for the natural/objective/intrinsic distance between objects in the real cosmos. The cosmos doesn't care how we look at it. It is as it is, and its up to science to find the best ways in all cases to investigate and discover "what it is", how it and its parts are shaped, how far it is between them and how all parts of it dynamically interact. (A little philosophy...)

You said: I replied (bold edit for emphasis): The Michelson/Moreley and subsequent experiments confirming constant c relative to any observer does seem to defy reason, as I agreed above, yet I accept the experimental results and do not argue against them. What those results do not confirm is length contraction as a logical consequence of constant c. That is what I tried to demonstrate in my little "jousters" scenario with a one Au "track" that does not contract. There have not been any experiments confirming large scale* length contraction, as many have acknowledged in this thread. *(Such 'confirmation' (or not) on a subatomic scale in a particle accelerator would require expertise in atomic physics, so I will not presume to criticize, though I have my doubts about how the "end points" are measured in the accelerator.) That leaves all relativity's claims about the validity of length contraction as applied to Earth, the Au, the meter rod and the distance through Earth's atmosphere not confirmed by experiments. Please answer the several unanswered questions/challenges in this regard in my last post. TAR2: Realism says that the whole cosmos and all of its parts are real independent of how (from whatever FOR) it/they are observed. The Cap 'n has said many times that a squished Earth ( or contracted Au, etc.) is just as valid a description as a nearly spherical Earth (or 8+ light minute Au), because 'there is no preferred FOR.' No, "the world" and all its properties are intrinsically real. How we see it doesn't change that. All the theoretical "slicing" of the "4-D Earth"* etc. or "the world" in general does not change that. * I have many times challenged the fourth dimension asserted above. Objects and the space they exist/move in are 3-D (described by 3 axes.) Time elapses as things move. Calling time a dimension coalesced with space does not change the the shape of things or the distances traveled when they move around in a "world" independent of observational FORs.

Cap 'n R, from my post 447: Again where does that leave the epistemology of empirical science? Hijacked by a theory of length contraction based on “no preferred frame of reference,” (also based on no experimental evidence) so the squished Earth is just as valid as the spherical Earth? From my post 453: Cap ‘n: Me: Again, how does elapsed time during movement contribute to changing shapes of 3-D objects (objects with volume) like Earth? Is a squished version of Earth just as valid as a nearly spherical Earth, according to length contraction or not? You made the case in great detail quite a few pages ago that the ship flying by at near c could see Earth as having a 1000 mile diameter, and that is just as valid as an 8000mile diameter Earth. Have you now changed your mind? I think you answered in your 459: So Earth has no intrinsic, objective shape of its own, independent of how it is observed?... and epistemology (how we know what we know) has no place in relativity... "thrown out" as it were? This is idealism, contradicting realism... that the reality of “the world” does not depend on how it is observed.... the constant theme of this thread. (Wiki... again:...” philosophical realism, the belief that reality exists independently of observers...”) You said: To my: ... Schrodinger’s hat replied: ... Do you agree with his reply or not? Cap ‘n: Seems reasonable since it is going c and he is going 1/2 c through the tail end of the beam. But I know the theory of length contraction has abandoned reason, so my appeals to the latter will be a moot argument in this case. I am saying (this thread contends) that FOR does not determine reality, even though c is constant. The beams of light each travel one Au in 8+ minutes, just like sunlight in the real world. My “track” was for distance-traveled reference. The light beams traveled over 5/8ths of the track length at c velocity while the observers firing the beams traveled 5/16ths of the track length, going 1/2 c. At that point on the track and after just over 5 minutes of travel they see each other’s beams.

Schrodinger's hat, replying to my: ... Really!! Then how is it that the distance to the sun, and the shape of earth and the length of a meter rod in the "real world" all vary with FOR? I had no problem seeing the animated simulator. I have never disputed constant c. It still doesn't make distances between objects, etc.,etc., in the real world shrink. S.h.: We have beaten this to death already. My pancake did not change shape "in the real world" when picked up off the plate (top view) and viewed on edge. I do not dispute that angular view of things, like the moon, as you suggested, changes with different points of view... only that the moon itself does not (obviously) change shape with differences in angular view. Glad to hear it again, as you said before. So science doesn't really know what shape Earth actually is?... the alternative I have often mentioned. It could have a 1000mile diameter, according to your near c fly-by observer? Who knows? In that case we can throw epistemology as applied to empirical science right out the window. They have both stated that length varies with FOR. This implies that there is no "real world", as it all depends on the FOR from which it is observed... the philosophical point of view challenged in this thread. :md: From a realists perspective, the overview of the whole scene, it is a "trick question" based on the assumption that FOR describes reality, and reality changes with different FORs. I (standing for realism) say it does not. Light travels at c. A flashlight traveling at 1/2 c and shining its light ahead in the direction of its travel will be traveling through the tail end of the beam it is projecting at 1/2 c. So the front end of its beam will appear to be traveling at 1/2 c relative to the flashlight, even though light is still traveling at full c from the starting point. This is why my "jousting lasers" scene was based on a one Au "track" with two end points, the starting points of the two jousters. So we need not claim that light is moving at constant c relative to some "ether," making space a substance or whatever. It moves at c relative to the point of origin of its source. That is another good reason to take it off the graph and put it in the real world, at least as a "picture" that relates to the real world. Ps; Wikipedia on realism: I have explained many times that FOR as substituted for "observers" in this thread does not require a person or subject, but can be an abstract point of view from different locations and/or different velocities relative to whatever is observed. Changes in FOR do not change "reality", which has a "life of its own" whether observed or not. (This to the forum in general. I have quit replying to Iggy in particular... Insert exact quote if you can find it.)

I am presenting realism here as the philosophy that reality, including the intrinsic shapes of objects and the distances between them in the natural world, like the distances between planets and the sun, do not vary with how they are observed, as per FORs at different velocities relative to what is observed/measured. All the above is independent of models, math and graphs and coordinate systems and assumptions about 4-D space. That is why I ask for illustrations using "pictures" or thought experiments based on the above "real world." So I don't see how that request is "unfortunate", considering realism as being about the actual territory, not the various maps describing the "takes" of various FORs describing the territory. What recent question by md65536? Speaking of recent questions, will you please answer mine above (bolded) and address the context preceding it: Have you changed your mind? If length is NOT invariant (i.e., it changes with FORs), then do you now believe, with Swansont and Schrodinger's hat and others that Earth does in fact drastically change shape and that the Au can shrink to 1/8th of its precisely astronomically verified length, and same with the meter rod? Or is it that we just can not know which is accurate in all of the above, given the "no preferred FOR" dictum? ("Poor science...")

About those four dimensions: I see 3-D objects in 3-D space (three axes describe volume, whether objects or the space in which they exist; and time elapses as things move. So Earth remains a nearly spherical object spinning and orbiting through space from one moment to another... time, right? It doesn't change shape (very much) over time. It exists as a nearly spherical object independent of how it is observed, from whatever FOR. (Realism.) So what happened to your claim that a severely oblate spheroid, as seen from the old near c fly-by frame is just as valid a description, because we Earthlings have no privileged FOR over the latter? Btw, I am "wired" to see things from an overview perspective* first, and then focus in on the details. That is why I keep asking you to make your case for length contraction as a whole and then focus in on details. Cook the eggs until they are done, please, at least once, so I can see the big picture before examining the parts in detail. And of course, I thrive on concrete examples in which I am not required to translate graphs into real world pictures. *(Reality as a whole, on whatever scale does not depend, for its existence or properties, on the different FORs from which it is observed. My "cosmos with no intelligent life" scene is an illustration of this principle. It wouldn't go away or change drastically sans observational FORs.) Thanks.

Cap 'n R: Trying to make my challenge look very stupid and ridiculous does not answer the question I have posed many times. Swansont insists that length is NOT an invariant property, that is changes with different Frames of reference. The diameter of Earth is a "length" and so is the space/distance between Earth and Sun, and so is a solid meter rod. So I understood him to say that the shape of Earth changes according to the FOR from which it is observed, and same with the other two distances mentioned. You, on the other hand, after much argument back and forth with me said definitely that Earth does not change shapes (from 1000 mi to 8000 mi diameter) that Earth does not move closer to Sun (to within 12 million miles or so) as observed from that famous near c fly-by, and that the meter rod does not likewise "morph" to 12 cm as observed from a similar FOR. Rather, you said that there is no way to know which frame of reference is correct... what I call the standard, Earth science measures of all of the above or the measures taken from the infamous near c fly-by FOR. (Your statue as seen from front and back was another illustration of your claim (relativity's claim) that "There is no preferred frame of reference." A little humor here in response to your ridicule: Poor science! It doesn't even know the true shape of our home planet or how far it is from here (now) to the Sun or how long a meter rod is... (like surveying the surface quadrant of Earth from equator to pole to derive a 10 millionth of it for the sake of establishing a standardized Earth to human commensurate measure of distance was a waste of time!) So PLEASE go ahead and cook those eggs if you will and quit trying to make me look stupid/ridiculous with an absurd cooked up or left raw example.The "if you will" is dubious but I am sincerely asking, and IF you will, thanks. (more editing)

Just for a break from my frame of reference thread and the challenge to the SR's theory of length contraction, here is a riddle based on GR's claim that gravity curves "spacetime." (Background: based on non-Euclidean geometry/cosmology and Minkowski's and Einstein's formulation of 4-D "spacetime.) Do the planets have circular-ish/elliptical orbits around the Sun or do they travel in straight lines through curved "spacetime?" If the latter, describe the posited curved medium, spacetime and explain why the orbits of the planets themselves appear to be curved.

I could have been more clear. We all know that light can not go faster than c, even when its source is going 1/2 c or whatever. I was just thinking that the apparent “length contraction” could be accounted for by the distance the rockets and their lasers travel *through* the tail end of their projected beams. So even though, in my experiment, each light beam travels over 5/8ths the one Au distance in just over 5 minutes, the lasers/observers themselves travel just over 5/16ths the distance in the same time... the time and distance it takes for each jouster to see the other’s light. No length is contracted and light maintains c velocity throughout, not 1&1/2 c. Back for more replies soon. Schrodinger's hat: Also for the umpteenth time, the philosophy of realism posits that there is a (slightly variable) distance between Earth and Sun which does not require our "definition" (like one Au or 93 million miles... in whatever units) or depend on frame of reference. Your lines in a box is an abstraction you created. The space (linear in this case) between Earth and Sun is a fact of nature which only varies with position in orbit (91 to 94.5 million miles.) No frame of reference or definition of distance is required for the dynamic orbit of Earth around Sun, all by its natural "self", or to create the space/distance between them. Of course, astronomy has measured this distance very precisely from our at rest frame, naturally. You still don't get realism's "world/cosmos" as is, sans any/all possible frames of reference or definitions. Ps, yet again (still hammering on the fallacy/absurdity of length contraction as per Cap 'n R's and Swansonts repeated assertions): In the real world, how does high speed observation (near c FOR) change the shape of Earth, Earth-Sun distance, length of a meter rod, etc? Alternatively, if FOR doesn't change the above (the Cap 'n's assertion), then does length contraction theory assert that we (science) can not know which shapes and measurements of the above are accurate. I will shut up and go away* IF someone will answer this to my satisfaction. *"Away" is relative. I still want to know what curves when GR claims that gravity curves spacetime. And if "spacetime" is a non-entity concept, the thread title still applies to the question of the "reality factor" of spacetime.

Just a near lightspeed fly-by without having read recent (since my last post) replies. What if “reality” did not depend on frames of observational reference, at whatever speed or location relative to the part of “reality” being observed? Just “what if?” for a moment, OK? What if the cosmos (or our local system) were not being “observed” from all possible “frames of reference?” How drastically would it change if not observed by us oh-so-intelligent beings. Not at all really. All cosmic objects would have their intrinsic shapes regardless of how observers saw them and their relationships in space. The distances between them would not change at all but for “natural causes” like out- of- round orbits and such or due to the expanding cosmos in which the 'distances' between galaxies is increasing at an accelerating rate (still a mystery as to the dynamic.) That expansion (distance between galaxies, etc.,) is not effected by observation. That’s it for now. I will read recent posts tomnorrow.

Nobody here is willing to consider the thread topic as pertains to "the world" as naturally occurring phenomena independent of different frames of reference (observers with different velocities) from which they are observed. No "takers" on discussing the nature and properties of the world and distances between objects with no intelligent life or observers traveling at different velocities. (An objective world without the quasi-subjective pseudo-reality of how it is all seen from different velocities and locations.) Schrodinger's hat insists: That gets hung up on presentism (everything is happening now) vs lack of simultaneity (now depends on velocity of observers.) I say time is simply how long it takes anything* to happen (not an ingredient in "spacetime")... *say traveling from here to there at whatever velocity... an hour to travel 60 miles at 60 mph. (spelling edit.) I said (repeated for reference below): I understand that FOR depends on velocity as well as location (which changes with movement, of course.) But, how does going faster, for instance, make distance traveled shorter? It doesn't. At 120 mph, the above 60 miles will stay the same distance, covered in half the time, 1/2 hour. (In the real world, that is.) And whizzing through our solar system at near 'C' does not make the distance between Earth and Sun shorter, just because it might look shorter than from at rest with Earth. This statement is based on realism, in which FOR does not determine reality. [second edit; an interjection; Regarding all those graphs, including my "laser jousters" word experiment version: Maybe the confusion is due to applying math to the impossibility of cumulative velocity of light and its fast moving source. Since the velocities can not be cumulative, one might assume that distance traveled must become shorter, or length contracted. This is solved in my mind by realization that light can not be pushed faster than 'C.' The rockets/observers/lasers in my experiment are traveling through the light beams they are shining ahead. The supposed "length contracted" distance (required by math) is actually absorbed as the lasers travel at 1/2 'C' through the tail end (closest to the lasers) of the very beams they are projecting ahead. ] How do different FORs from which all above examples are observed make the objects and distances themselves** (as they are, sans intelligent life observing and measuring them) different? In the real world, how does high speed observation change the shape of Earth, Earth-Sun distance, length of a meter rod, etc? It doesn't. Until this objection is addressed the rest is argument about manipulating models of the world (not the real world), spacetime*** coordinates, FORs at different velocities "seeing" the world differently, and denial of an omnipresent Present. (No matter what velocity an observer is traveling, now is now, same now everywhere.) *** Whether just an abstract non-entity, a metaphorical "rabbit pelt" or a malleable medium as supposed in GR.

Still begging for clarification of relativity of simultaneity as in how it can logically contradict presentism. “Even considering different FORs, I know that the past is no longer present and that the future is not yet present, so that leaves us with the reality that what IS happening now IS the present. How can this be wrong?” Since simultaneity means happening at the same time, on what basis does relativity’s lack of simultaneity (or “relativity of simultaneity”) deny/contradict the above? Repeating that it doesn’t depend on light delay doesn’t answer the question. This thread is on the philosophy of science, particularly relativity’s claims about frames of reference determining reality, or FORs as a qualified* subjective criteria for “reality” as a form of subjective idealism. *(No person or subject required to establish an abstract FOR, reality depends on FOR,... how you look at it.) Here again is a summary of the above summary post: (My post 404) See again the bolded portions of post 418, still not addressed. Schrodinger’s hat: This thread poses a philosophical challenge to some of relativity’s most absurd assertions based on the theory of length contraction.... specifically, that Earth’s diameter, depth of atmosphere, distance from the Sun, and the actual length of a solid meter rod all depend on the frame of reference from which they are observed and measured. See all versions of realism’s rebuttal above. Philosophy of science is appropriately presented in a philosophical “manner”, as above. We need not start with the “scientific” dictum “there are no preferred frames of reference” from which to describe “reality.” The "world" (let's stay concrete and say Earth) already had a reality of its own (and distance from the sun, varying only a bit in its orbit) before life evolved here, much less intelligent life with nimble minds, clocks, and measuring rods. You still have not acknowledged this fact, upon which realism is based. Reality does not depend on frames of reference from which it is observed. So science must investigate “reality” and all of its intrinsic properties from the most reasonable frame of reference possible for each object of investigation, be it objects themselves or the distances between them in the real world. Again, you say, “Things that are spatially distant and moving at a different velocity do not share my now.” You (and the relativity of simultaneity in general) claim that there are different, spatially separate “nows” as if the claim itself debunks presentism’s claim that the present IS everywhere now, regardless of the space between locations. And the Cap ‘n repeats that it (relativity of simultaneity) is not about light delay between FORs, not about the distance between them. Which version is it? You say: There is no point in that if you continue to *assume* the primacy of frames of reference for describing reality in direct contradiction to my above arguments. However, if you will “please” reply as above repeatedly requested, then I will again go ‘back to the drawing board’ with you.

Backing up for background clarity before addressing more recent posts, tomorrow (just another quickie): Schrodinger’s hat: I hope that you realize that this is a philosophical position you are *assuming.* (I know... based on the doctrine of relativity of simultaneity... the "teaching", as it were.) So if you can not see their now, it isn’t happening now. Is that what you mean? Would you mean that a solar flair is not now happening because we can not now see it? We will see it in a bit over 8 minutes, but that is 8 minutes from now-there-and-now-here,... same now.

To my: Cap 'n R asked: "How do you know?" How do I know that now is now regardless of location? If the lightspeed limit has nothing to do with the relativity of simultaneity, then distance doesn't matter and the present IS the present everywhere, one universal "now" rather than an infinite number of local "nows." Even considering different FORs, I know that the past is no longer present and that the future is not yet present, so that leaves us with the reality that what IS happening now IS the present. How can this be wrong? Here is my post (edited) 404 again (to save going through the last page). It could stand as my last post if no one will engage the philosophy of it or my thought experiment contrasting a real as is world with one dependent on frames of reference. (I will finish with unfinished business with Schrodinger's hat. and a note on a witch hunt.)) Schrodinger's hat: me: S.h.: So... again, still, whatever... how is a length contracted Earth diameter and a length contracted Au (or meter rod) "conflating" different concepts? A final? note: I could reply to md65536's post 410 about 'that guy' with identical IQ scores to mine, who got banned from four forums; but, it would be way off topic, and it would require that I defend myself (why I got booted in each case, quite an interesting drama, really)) against the kind a witch hunt common in science forums when mainstream science is questioned or criticized. (I have done my best to follow the rules here, and the forum has been better than average in tolerance* (aside from a few personal attacks) of my persistent criticisms, for which I thank you.) * As in not banning me for my criticizing the mainstream. Sorry, I left out the timestamp and your second comment and question replying to my: "Location of events/objects does not dictate what “now” means, as relativity insists." "No", what doesn't...? Relativity does not insist or agreeing that ""Location of events/objects does not dictate what “now” means...?" If the present (now) does not depend on location ("here a now, there a now, everywhere another now, location specific") then what does the relativity of simultaneity mean? Thanks.