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This is an afterthought on Iggy’s intentions, aside from the content of science debate here, and before reading replies since my last post. (Soon) I gave him the benefit of the doubt, that he simply does not understand what I am saying here. But then I realized that I had given him my exact IQ scores*, since he seemed to think I was exceptionally stupid. (*SBIS; 170 and WAIS 178.) So he intentionally exaggerated the above as a 200 IQ. As a psychologist I can only assume that he was misrepresenting my IQ intentionally to influence readers to believe that I am a liar. Malice is quite different than stupidity. I would appreciate the administration’s attention to this kind of harassment. Thanks.

This thread is appropriately in the philosophy section because it contrasts realism with idealism vis-a-vis relativity theory, specifically the concept that frame of reference, as in “there is no preferred...” determines “reality” in the same sense as subjective perception, with the difference that no actual person or subject need be present at any given frame of reference (FOR). My primary illustration of FOR as such a qualified “subject” in subjective idealism has been relativity’s claims about of length contraction. Since thought experiments are well accepted in relativity theory, I proposed one in support of realism as debunking length contraction. I was told that length contraction is irrelevant to this thread's argument, by a physicist. I replied it was very relevant, but the Cap ‘n (admin.) supported the physicist as a valid arbiter of such relevance or lack theerof. Though I did teach university level (undergraduate) “Logic and the Scientific Method” as part of a “Philosophy of Science” curriculum, I am told that basically physics trumps philosophy here even in the philosophy section, so, therefore length contraction is irrelevant here because a physicist says so. The above physicist (Schrodinger's hat) had previously said that my above thought experiment made no sense to him. It is really very simple. If there were no intelligent life measuring things and the distances between them, would they still have an objective existence and intrinsic properties or not? An idealist will claim that reality depends on how it is perceived, while a realist will grant that “the world” in most general terms exists “as is” with or without perception and measurement of it from different FORs. So, the realist will (and I did) disagree with the relativity theorists who claim that the shapes of things, for instance, depend on the FOR from which they are observed or measured. Cap ‘n R presented some thought experiments of his own to illustrate that a severely oblate spheroid describing the shape of Earth is just as valid as a nearly spherical Earth, because of length contraction as observed from an extremely high speed FOR, since “there is no preferred FOR." Another of his arguments was a metaphor of Earth as a statue seen from different angles (backside vs frontal view), like Earth as seen from the above extreme FOR. Then we have the distances between objects in the cosmos, starting close to home with our solar system. A realist like me say that the distance between Earth and Sun, for instance, does not actually vary with the FOR from which it is observed, but only with Earth’s position in its elliptical orbit. I also say that Earth’s atmosphere does not actually vary in depth (distance through it) with the FOR of an incoming muon, for instance, an often cited argument for length contraction, as in “for a muon... it’s way less than the standard 200 or so miles.” And, btw, all the above “realism” does not require that the speed of light be variable. My last thought experiment in that regard kept lightspeed constant even as the observers proceeded at 1/2 lightspeed with their lasers going ahead at ‘C.’ The velocity of light does not increase when fired ahead from a rocket going 1/2 lightspeed. Light can not be “pushed” faster than ‘C,’ and the one Au “track” hosting the experiment does not change lengths (contract) during the 5+ minutes each observer travels before seeing the other’s light. (Iggy constantly misrepresents me... I don’t know whether intentionally or because he almost always misunderstands what I am saying. I think the latter, from past experience.) My objection to the relativity of simultaneity is also based on realism. Regardless of clocks and clocking all things everywhere are happening now, regardless of location or who sees what and when from different FORs. “Now” still means “the present.” Now IS the present. Location of events/objects does not dictate what “now” means, as relativity insists. Anyway, I hope this helps to clarify what this thread is intended to be about. Ps: All snide remarks about me recently degrade the quality of this site into the "personal attack" mode, rather than respectful exchange of ideas about science and the philosophy thereof, however much we disagree. Just sayin'.

Schrodinger's hat: I did complete the illustration, and ‘C’ stays constant. The task was to answer when each observer would see the others’ laser light (how much time would elapse) and where along the one Au “track”, i.e., distance traveled by each observer. They are in symmetrical relation to each other, so the figures are the same for both. I picked the one Au distance between them for its commonly known length, which does not change during the run. That length is 8 light minutes, rounded off for simplicity. Their velocity is 1/2 lightspeed, and, of course, their laser beams are traveling at ‘C’ toward each other. In 8 minutes each observer would have reached the midway point and each laser beam would have traveled the whole track to the opposite end from their starting points. So the “rewind” was required to answer the questions. After 4 minutes each observer would have traveled 1/4th of the track and their light beams would have reach the midway point. After 6 minutes the observers would have traveled 3/8ths of the track while their light beams would have traveled 3/4ths of the track, having already passed the opposite observer. So, each observer would be between their 1/4 and 3/8ths marker on the track (out from their respective starting points) . That would be just over 5/16ths out from each starting point when they see each other’s light, which had traveled just over 5/8ths of the way in each case. Each would be just over 5 minutes out. (Feel free to specify fractions down to 1/32nd of the track if you like.... and how many seconds over 5 minutes elapsed.) So, there it is again in words. (I have no graphics capacity on my computer.) The speed of light stayed constant from both lasers (not gaining more velocity with the 1/2 ‘C’ observers' velocities. No distances (lengths) “contracted.” Edit; Ps; An interesting comment by Schrodinger's hat above: (my emphasis) So you are now saying that length contraction does not reflect an accurate measurement of objects or distances in "the real world" but rather an error of omission in calculation? Still catching up with past comments... like this from Schrodinger's hat, post 390: I have challenged the transition from Euclidean to non-Euclidean geometry and cosmology with many specifics, mostly in the "Ontology of Spacetime" thread, and mostly citing Kelley Ross's paper on the subject... which has been ignored in this forum, since the non-Euclidean version of 4-space has become so well accepted over so many years, since Minkowski and Einstein codified it. Any realist will accept that objects (with volume) and space "itself" (as volume itself, not an ingredient in "spacetime) have three dimensions: often referenced a length, width and height. Geometrically, a line is one dimensional, a plane is two dimensional, and volume is three dimensional. Time elapses as things move, which they all do. Light travels through space at the almost universally accepted constant, with which I agree. No contradiction in all of the above. That "now is now, period"... without location restrictions is not a contradiction to the above, either. 4-D space is based on a non-Euclidean *model* which reifies time and combines it with space... all of which is very debatable, as in above mentioned thread. The fourth dimension is the *assumption* here.

This is just starting in order of replies. Called away soon but back to finish when I can. (Sorry, the timestamp requires too much editing for now.) Schrodinger’s hat: I just clearly said that clocks in orbit tick slower than clocks on the surface. I also clearly said that everything is moving. This is frustrating when you don’t seem to hear what I just clearly (I thought) said. Yes, clocks in orbit and astronauts in orbit (I think) both “experience” a slowing down of physical processes, “ticking” in the clock and “aging process” in the astronauts. (Again, I thought that this was clearly stated in my last post. There is a very real communication problem here.) Another example of you simply not listening: Me: You: Ummm... relative to clocks on the ground. I just said that in-orbit clocks tick slower and have a higher velocity relative to clocks on the surface. Gotta go. Back soon, I hope.

Earth does not become contracted. Reality is not ALL about frames of reference. I have likened FOR to "subject" in subjective idealism with the difference that no person or subject need occupy whatever abstract FOR. Yet when a length contraction advocate says that "for a muon, earth's atmosphere is way less than 200 miles"... he claims that that is just as accurate as the well established "length" or thickness of the atmosphere. Wrong. Hopefully I just addressed the "subjective" issue. If one believes that reality depends on the FOR from which it was measured, that is a form of idealism in denial of an objective "world" independent of how it is observed. And the moon doesn't change shape with the variable "angular size" as seen from different positions. Get "up close and personal" with each moving object to get the most accurate measure of each. For the overall relationship between them, look at the overview, not from the individual FOR of each. See my "jousting lasers" thought experiment as an illustration of two moving objects. (They were both going at 1/2 lightspeed while firing lasers at each other, just to make it simpler, but if they were going different speeds, the math would be more complex without changing the principle... which was 'no length contraction.') So you say. Are you the arbiter here for what is and is not relevant? The claim of length contraction is totally relevant to this thread's topic. Does earth change shapes or not? Does the distance between earth and sun vary with FOR or not. Realism says "not," and the FOR version of idealism says "yes." Yes, clocks in orbit have a higher velocity relative to clocks on the surface, and tick more slowly. The trade off seems to be that they are also in a lower gravity field than clocks on the surface, so relativity does a good job of figuring them both out and keeping, for instance, GPS guidance very accurate. Yes, I think astronauts at higher velocities than surface dwellers also have a slower physical aging process while going faster. To: "How do we define not moving?"... At rest with the object or distance measured. No. I have re-posed several unanswered questions, repeated in my last few posts, and I think they deserve answers before you go ahead assuming that all of reality depends on frames of reference. Of course velocity of objects is defined "relative to what?" I went into great detail on that, and it need not be repeated. (Car rel. to road; road rel. to earth's center; earth rel. to sun; sun rel. to galactic center, etc.) I have re-studied the summary of the Michelson/Moreley experiment and more contemporary experiments (abstracts) verifying the constant speed of light, so I know how it is derived.

md65536: No, that's not what I'm saying. Objects with volume are 3-D objects. Time is often considered a 4th "dimension", but I just see it as event duration, how long it takes physical processes to happen. A pancake is a 3-D disk with thickness/volume. It will look like a disk of whatever thickness on your plate and like a line of that thickness when turned on edge. It stays the same shape, regardless of how you look at it. Earth is a nearly spherical 3-D object. It doesn't change shape either as you look at it from different frames of reference. Length contraction claims that either it does change with FOR or that we can not know its true shape because of the "no preferred FOR" dictum of relativity. We know its true shape, but length contraction advocates are in denial of this well established knowledge. It is not about definitions. Realism says that the distance between Sun and Earth (and the shapes of both) do not depend on measurement. Cosmos and all its parts exist, with all their intrinsic properties independent of measurement. The task of science is to measure things as accurately as possible. At rest with those objects is best, not flying by at high speed. As for distances between objects, either at an end point ( at one of the objects) or midway between them are the "preferred frames of reference" from which to measure them. I am not denying relativity per se. I deny that "curved spacetime" in GR is essential to how gravity works. We observe curved trajectories of objects (and light... perhaps with a non-zero mass?) being pulled by gravity. The "spacetime fabric" is like "the Emporer's New Clothes" for me and for many critics in the International Society for the Advanced Study of Spacetime. I agree that the speed of light is constant, as per SR. I do not agree that simultaneity is relative, as explained over and over above. Now IS now everywhere. And I obviously do not accept the validity of length contraction or time dilation. The world/cosmos does not change to accommodate measurements from different FORs. Clocks tick slower at higher velocities and in higher gravity fields. Time does not "dilate" or slow down. Clocking time is an artifact of measure, but physical processes "proceed" (earth turns and orbits) whether measured or not. I hope this clarifies my position. Ps, (edit): I could have used the other "reply" button to timestamp this and give the quote notification, but I forgot. Just a bad habit. Sorry.

I have some spare 'time.' Backing up to my last question to swansont: post 312: You: Me: I wonder if the above explained my position more clearly and you quit the challenge or what. (...Or if the "what" is that you do not agree to a respectful conversation, since that would be a 'first.') Ps: The timestamp and quote alert for post 312 didn't work for three pages back (or my error), but if swansont is still interested, he will check in... if not... no more harassment from him, which is fine.

This will be a complex post with a "time lag" trying to sort out and make sense of conversations on the last page with Cap 'n R and also an up to date reply to Schrodinger's hat. Starting with the latter. You said: This is what I’ve been saying throughout this whole thread. Where does that leave the “length contracted” earth of 1000 mile diameter, as seen from a near lightspeed fly-by FOR, as posited by Cap ‘n R? You say: ...ignoring my critique of “4-D objects” as 3-D objects plus the time factor. You continue; ...Still ignoring my challenge that earth, sun and moon are real objects, and you can not slice them. The coordinate system which you can slice any way you like is not the actual solar system with all of its real, 3-D objects, in motion as they are ‘through time.” Repeating another summary of the point of this thread: Now to my question to Cap’ n R in post 348: I said: You answered: So you changed to moving walls. My argument has always been that the overall view of the scene in question is the “reality” of the situation, not the individual frames of reference. Will you please address this point? (Your next reply did not.): I replied: You continue: You are speaking of the appearence of "certain events (changing) order" depending on different FORs. I replied: To my: You answered: What? If they happened at the same time, they were simultaneous. When you see them is about light delay. Now to your last posts on the last page: Post 357: Very confusing. “Yes” to first statement. “Happening at the same time” is what simultaneous means, and what is happening right now is all happening at the same time. Second statement makes no sense.(Where did I say it did?) If they are happening at the same time, changing reference frames will not make them happen at different times, even though they will be seen at different times. Elaboration: Distance between events does not change the "when they happen," only when they are seen in different FORs, repetitive as that is. Post 359: From all of the above. Now, finally to the last exchange with Schrodinger's hat. Me: You: No. To the contrary: I'm saying (realism asserts) that the distance to the sun doesn't change with how you look at it, and that a pancake doesn't change shape when you look at it on edge, even though it appears to do so.

Just a quick pass through here. Schrodinger's hat: Just to clarify: The pancake does not change from a disk (as I called it) to a 'fat line', (specified to acknowledge that the pancake has 'thickness'.) It stays the same shape, no matter how you "slice it" or look at it. These are real objects, according to realism. You can not "slice them!" You can "slice" your model of them on your imaginary coordinate system and make them into any shape you want. And "a line of constant t" reifies time. It makes sense on your "coordinate system" but you are "slicing" nothing but that graphic concept. You can not believe that Earth changes shape with how you "slice it" in different frames of reference. Correction, you can believe anything you want, but that doesn't make it science.

TAR2: Yes. Schrodinger's hat: As long as you think that there a many “nows” you deny the meaning of simultaneity, which is “happening at the same time” with no location restrictions or concern about image travel time. Relativity’s assertion that “time is relative”, makes more of it than elapsed time for light’s travel. There are two concepts of simultaneity being expressed here recently. One is seeing images of two events at the same time, which means that the two events must be equidistant from the observer. The other is “happening at the same time” (period)... regardless of when events are seen. This is universal presentism. Schrodinger's hat: You assert that these are all 4-D objects as if Minkowski spacetime, based on non-Euclidean geometry and cosmology were a given, established fact. It is not. I have argued vigorously against those *assumptions* in my “ontology of spacetime” thread and elsewhere. I will not repeat all the arguments against. All “objects” beyond the geometric point, line, and plane (with zero, one and two dimensions respectively) are 3-D objects, and the space they exist in is also 3-D. Time elapses as things move, not a dimension, per se, but a very “real factor” since the universe is not a static snapshot. I am glad that you realize that these objects “ exist and have intrinsic properties, no matter which frame they are viewed from.” Too bad you require 4-D space and objects to get there, and even then, what happens to "length contraction" when "objects that exist and have intrinsic properties, no matter which frame they are viewed from"? Back again to the "true shape of Earth" debate. Does that not depend, as the Cap 'n insists, on frame of reference, or do you disagree with him. What is happening now Is happening presently, regardless of when we see it happening or where it Is happening. Therefore positing different “nows” or a lack of simultaneity based on different frames of reference or the constant speed of light is wrong. The version of presentism I just re-presented above has nothing to do with any ether model. The conclusion does not follow unless the premises are agreed. (Yes for realism; no for any ether model) . Seems like you are asking me to define distance without referring to the concept of the linear space between points or objects, how far it is from here to there... etc. I really don’t know how to put it differently than I already have. I tried to explain via realism, that without any intelligent observers with measuring sticks, the *whatever-you-want-to-call-it* between objects would remain as is, not dependent on or changing due to different frames of reference. Sorry, the best I can do. (Assumption: A real world/cosmos exists as is whether observed and/or measured from different frames of reference or not.) Time (for the hundredth or so ‘time”): Event duration of physical processes. A chosen starting and ending is required for measurement thereof, but the earth keeps on turning and orbiting... event duration... whether or not we measure it and assign time units or "the beginning and ending" of a day or a year. I disagree, as above. ‘Happening at the same time’ is not dependent on “According the observer of frame that is currently being considered.” Neither the time required for info to travel* any distance nor the constant speed of light negates the universality of the present, now everywhere... *it just “takes time.”

I'm gone again for the weekend. Maybe "Is-ness" is just too simple to understand once one is convinced that everything everywhere and every-when depends of frame of reference and denies simultaneity because of the time lag for info about what is happening now elsewhere. "Is," the present, happening now has no logical location boundaries. Light, of course conveys images and information over distances at 'C' velocity, so we can not know what is happening now elsewhere until we see it or get the info. But I am repeating. See y'all Monday.

My argument (realism) is that reality does not depend on how we see or measure it. I had hoped you could imagine an earth, sun moon, etc., and their relative positions existing and having intrinsic properties as if there were nobody looking at them or the distances between them from different FORs. That would make my point. If I take a pancake and turn it on edge, it will look like a fat line, not a disk. But it remains the same pancake, regardless of the angle from which I observe it. Same applies to relativity's FORs. Reality stays the the same (in this context... though everything is moving) regardless of how you look at it. That IS my philosophical point, and it negates "length contraction." How fast something is going does not make the distance traveled shorter, just the time it takes to get there. (In all these statements, "according to realism" is implied.) I'm saying that the distance to the sun doesn't change with how you look at it, and that a pancake doesn't change shape when you look at it on edge, even though it appears to do so. Earth doesn't change shape with how you look at it. We all know that it bulges just a bit at the equator. Polar diameter is about 7900 miles, and equatorial diameter is about 7927 miles (just for a change of units.) I have agreed (several times) that the speed of light is constant, not effected by the speed of its source or of its observer(s.) I have even used the bullet from a moving gun illustration of the difference. Still no argument against. Still doesn't address my assertion from realism that what is happening in the real world does not depend on the FOR from which that happening is observed. See my "jousting lasers experiment" on a one Au "track." I accurately stated what both jousters saw when and where on the track, which stayed the same length. Point: An over-all view of the whole situation does not depend on the individual FORs of the players. Events happening right now are simultaneous no matter where they are happening or how long it takes any observer anywhere to see them. Simultaneity in the real cosmos does not depend on the FOR from which events are observed.

I would move to stay equidistant between them and stay on the train to minimize the variables for my measurement. But I have a feeling that this is beside your point. And you have not addressed my pursuit of understanding constant lightspeed as logically requiring the relativity of simultaneity. Me, again: I said; You replied: Please show me the difference, i.e., how exactly I am conflating, as above. Again: Rather, you change the situation, before the above is resolved, as with: Schrodinger's hat: But it does depend on the FOR from which it is measured. You continue to ignore my illustration that the world (cosmos, moon, the space/distance between Earth and Sun, etc.) exists independent of observation and measurement from different FORs. Your complex FOR exercises totally avoid my above argument for realism. "The world" does not depend on how we look at it for its intrinsic reality. Edit, replying to your: For a realist, looking at the concrete example of Earth as seen from the space station, for instance, its spinning is irrelevant, no matter how slow or fast. We can see the whole Earth in profile, and it appears as a disk with a mean radius of 6371 km. From an extreme FOR, as discussed to death here, it may appear as 1/8th of that, but the real Earth stays very close to a 6371 km diameter, and the 'squished Earth' observation/measurement, if there were one, which there is not...would be a gross error.

Cap 'n R: It is very clear. My argument and this thread topic distinguishes what is actually happening in the real world from the variables from different FORs describing such happenings. So, you, at rest with and in the middle of moving car, between the two lights, will have the advange for accuracy over me, not at rest and in the middle of the observed phenomena. Sorry, but I was frustrated when I said the following and mis-spoke: "I see a lag between one light hitting the wall and the other..." As we have agreed before, the great mystery of constant ‘C’ is that your motion in the train and my stationary position makes no difference to when light is seen by either. The forum topic challenges the reality of changing shapes and distances between objects due to changing FORs. Now we must deal with the assertion of relativity, as you said: . Me (to another respondent): Please detail the logic from, “The speed of light is constant" (agreed) to "the relativity of simultaneity." (I disagree.") We know that things happening at the same time in different locations are not simultaneous for observers in different FORs. This is why you say that simultaneity is relative. But they are still simultaneous regardless of from where and when they are observed. What is happening on Earth and on the Sun is all happening right now, not dependent on when we see, say a certain solar flair, which of course will be over 8 minutes after it happened. Cap 'n R: Yes, very clear. I understand English much more easily than trying to translate the meaning of graphs into a real -world scenario. Thanks. Will you please address my take on simultaneity above in equally clear English. Then maybe we can move on to your conclusion as pertains to length contraction. Schrodinger's hat; Now we are getting "down to it" for realism vs idealism. SR says that since lightspeed is constant, distance traveled must not be invariant in certain situations... i.e., "length contraction." Realism argues from concrete situations, saying that the Earth-Sun distance does not vary with the frame of reference from which it is measured. In the real cosmos, bodies do not move closer together and further apart each time the distances between them seem to vary as measured from different FORs. What say you? Edit, Ps: Another way to put the realist argument was my thought experiment, which you said made no sense to you. What part of this do you not understand?: Without intelligent life in the cosmos, it would not be drastically different on cosmic scale. Without measurements, things would remain as they are, aside from the catastrophe perpetrated upon Earth by "civilization." Earth would have the same orbit around the Sun, varying only a little in distance between bodies with position in its elliptical orbit.

Repeat from my post 328: Yes, I know lightspeed is constant, same time to reach either wall 5 meters away, regardless of the train's speed, also regardless of the two FORs from which light hitting the walls is seen. You said: So, the lights hit both walls at the same time (simultaneously), in the real world, period. You see it happen simultaneously because you are in the middle and not moving relative to the train. I see a lag between one light hitting the wall and the other, because I am not midway between them, and the whole shebang is moving relative to my position on the tracks. Yet signal delay and the difference in observer velocity is not relevant? No, that is not clear. You say that I "... don't yet seem to grasp the fundamentals of relativity." I disagree with the assertion of relativity that simultaneity is relative. Things that happen at the same time do so regardless of differences in when they are seen to happen due to differences in FOR. The differences in our FORs does not effect the simultaneity of the lights hitting the walls, but just when each of us see it happen. Your turn. I am and always have been sincerely "discussing in good faith." Your false judgment and resulting accusation that I am not is personally insulting. Likewise your judgments and insults that I am indecent, rude, trollish and childish. Cap 'n R has not "proven" that relative simultaneity is a logical consequence of a constant speed of light. I "disagree." I seriously doubt if you were able to follow my argument against. I'll make it as simple as I can for you: Now IS now regardless how long it takes light to convey a "now happening event" from one location to another. I argue from realism in which what is happening now does not depend on the FOR from which it is seen. I will not be replying to any more of your posts. I have a little free time to reply to one of Schrodinger's hat's recent questions, bolded below. Responding to my: Schrodinger's hat: At rest with the object or distance being measured, as far as is possible. Otherwise as close as possible to an at rest frame with whatever is being measured. Whizzing by at near lightspeed will not be a "preferred frame" of observation for any scientist with control of his experiment. Wow! Someone is really mad at me. Another two demerits! (Is there a limit per post?) I wonder who... But seriously folks, To another "decent" question from Schrodinger's hat: Replying to my: You said: The definition of distance from a realist is how far it is (in any conceivable units of distance) from one point, locus or object in the real cosmos to another, as illustrated in my quote above. That does not change with how it is observed.

Yes, I get that the bystander's FOR is different than the guy's in the moving train car, and both see things differently, if that was your point. I just reviewed the last two pages of our conversation to see where we went from my challenge of length contraction to your argument for the relativity of simultaneity. I found it and will very briefly review. We were discussing one of my favorite challenges to length contraction, the variability or not the Earth-Sun distance, the Au. I argued that it changes only with the irregularity of the elliptical orbit, and you were were, I think, arguing that it also changes with different frames of reference (FORs.) The forum topic challenges the reality of changing shapes and distances between objects due to changing FORs. I gave the realists view of simultaneity (and common definition) above as simply "happening at the same time." Clearly it takes time for light to travel and convey information, so the above does not imply "seeing" such a simultaneous happening at the same time from different FORs. We recently had this exchange: Me: You: Now to a review of your offer and my request for "a concrete example" (with an eye to "example of what?) You: Me: You: (My bold.) In the context of what I just said about simultaneity and (basically) signal delay, the above denies the dictionary meaning and makes "happening at the same time" dependent on delay in seeing the happening from different FORs at different times. If that is a misconception, then so is the assumption that spatial distance is also relative. I now regret that I took up your offer. I had already shared my understanding of simultaneity, and agree only that there is a time lag between observers who see the same (simultaneous) event from different FORs, ergo at different times. That still leaves me with the same old question for you about length contraction. I'll state it differently for variety: Do the Au, the shape of Earth and the meter rod all stay invariant (as is, objective, independent of measurement) when you combine space and time into a "rabbit pelt" or whatever concept, or do you believe either that they do change with FOR or that there is no way of knowing their true measurements and shapes because of the "no preferred FOR" dictum of relativity?

Cap' n R: Your piece-meal approach is not working for me, as evident in my last reply. I can't even think of a good question to ask for clarification. So, I will patiently wait until your argument is complete, assuming that you will eventually make your case for length contraction, and then I can respond to the completed argument. Thanks. (Obviously I have seen both graphs already and know that the train is moving and lightspeed is constant.)

This is so childish. You slam me with the implication that I am an amateurish crackpot or a troll. (I am in fact an amateur scientist, with no apology.) I reply with how lame your argument is. I am willing to be respectful if you are, but I will not hold my breath hoping for such an agreement, given your track record with me from the git-go. You missed the point that realism supports the general (non specific) proposition that "the world" in general is real, as it is, regardless of how we observe or measurement. If you say that some of "the world's" properties are intrinsic, again, "good for you." You are a realist regarding those properties. If you say some properties of "the world" are not intrinsic, then you are an idealist regarding those properties, because they will depend, for their pseudo-reality on the FOR from which they are measured. Clear enough? Wait! You are still in the middle of a ten meter room, now a moving railroad car, and regardless of its movement, it will still take each laser the same amount of time to reach opposite walls. Lightspeed will get no help from the velocity of the car. What I see doesn't change what I said above, and I still don't see an argument here for length contraction as a result of constant 'C.' In other words, as per thread topic, FOR does not create or change reality. Oh, no, another demerit! Turns science into a popularity contest, to the discredit of this forum... a lot like name calling as an argument.

Thanks for the clarification. An event is an object or happening with a "timestamp." How is that different (if it is) than my example of sun-earth distance-between-objects right now (with timestamp on measurement) and a few months from now (new timestamp) showing a bit different distance-between-objects? (Still working toward establishing that that distance does not (actually) vary to extremes with different FORs, but just with position in orbit. Yes. Frankly, it is ultra-simple, and I wish you would forget the baby-steps and just make your case. Seems we have been here before with your several diagrams of the moving flashlight and observer... claiming length contraction... and my counter argument (not addressed) in a quasi-real*-world setting one AU long (*the well established average sun-earth distance.) But, please do proceed anyway. Schrodinger’s hat: (my emphasis) My point in defining time as event duration for physical events (with examples) and space (in its linear dimension) as the distance between real objects in space... is to demonstrate that time is not something that slows down (as per “time dilation”), even though physical processes (like clocks ticking) slow down in certain circumstances,... and that the real distance between objects (like sun and earth) does not vary to extremes with the FOR from which they are measured, as length contraction would have it. This is relevant to the thread topic in that my above argument grants reality to physical objects, the distances between them, and the elapsed time for those processes to happen, independent of whether or not any of the above are measured or from what FOR. Still addressing Schrodinger's hat's post from last page, you said: In a limited sense, this supports the length contraction argument that there is no reality to distances between objects independent of measurement. You totally ignore my thought experiment in support of realism, as follows: The earth-sun distance has a "life (reality) of its own" and the distance varies with earths (elliptical) orbital position, not with how it is measured from different FORs. This point directly addresses the thread topic.

Yes, please give a concrete example. Is “event”, as you use it synonymous with “object” as I use it? (Refer to my recent efforts at ”translation” from relativity lingo into realism plain talk.) You assert as a fact that "Since simultaneity is relative (a logical consequence of the constant speed of light..." Simultaneity means to me and in most dictionaries, some version of “happening at the same time.” Now IS now, whether one IS here or there, regardless of how long it takes light (and information) to travel from here to there. Make sense so far? If that seems wrong, how do you think it is wrong? Then, what does “simultaneity is relative” mean in the above context? As I have said before, the constant speed of light can not make the earth change diameters or the meter rod contract to 12 cm or the “actual distance” between Earth and Sun contract to 1/8th of its astronomically verified distance. So where does that leave the length contraction argument as pertains to the observed solar system? Please answer the above as directly as possible in English without the debated math concepts by which Earth either morphs drastically (to accommodate different FOR measurements) or by which no accurate knowledge about its measurements is possible. (As per "no preferred FOR, and each is different.") Thanks. I'll try to get back to arguments proposed by others soon. You say, "Delta x[/math] is the spatial distance between two events which occur at the same time." Maybe my (supposed) confusion arises from the special usage of "events" here. That is why I tried to clarify the difference between objects, like sun and earth, their relative position (distance between) at any given time and how you use "event." The act of measuring could be called an "event" too, but that would really muddy the waters. Earth and Sun both exist right now at the same time, and right now there is a given "actual distance" between them which does not depend on... lets just call it FOR. If we measure that distance a few months from now (forget 10 yrs... It might be in the same orbital position...), it will be different, because its orbit is not a perfect circle. Cap ‘n R: What does “the time between events mean?” The time between the event of breakfast and dinner may be so many hours. When you call the earth an “event” and the sun “an event”, what would the “time between them” mean... just signal delay for light’s travel? The distance between them only changes trivially over time because of the out of round orbit. Backing up to replies in post 309 by Schrodinger’s hat: (Sorry for the delay. It has been a busy thread.) I know it is common relativity lingo, but really!... Space-like and time-like? What is the reason for the hedge? Space has three dimensions, not "space-like" dimensions. And time is... “like”... what elapses as things move. Yes, things moving through space can be described as having a vector or trajectory through space. S's hat: Many cosmologists think that space is *something* that expands, as distinguished from the obvious fact that things in (empty) space/volume move away from each other. I mean to assert that “time dilation” and the “time” part of “spacetime” are only artifacts of measurement. Duration is elapsed time from “tick” to “tick” or from sunrise to the next sunrise at a given surface location on Earth... or from one “now” to another during any physical process. As a realist and an ontologist (asking “What is it?” in all cases), I do mind. Both cases above are meaningless tautologies, asserting that space (distance) is “what meter sticks measure” , and time is “what clocks measure.” It tells us nothing about either except that they are conventions of measurement. In the real world, 8+ light minutes is the distance between Sun and Earth, using lightspeed as a constant for actual distance traveled through space in a conventional time unit. Me: Schrodinger's hat: Yes. I just have a beef with designating “dimensions” beyond 3-D space (and time as event duration), because M-Theory has abused the concept of dimensions to the point that there are seven of them posited beyond the above four with no empirical bases whatsoever. Yet it pretends to be science. Well, I didn’t get all the way through your post 309, but that’s all for now.

Iggy, You constantly misunderstand and/or misrepresent me, and I am quite tired of it. Now again I must clarify in case someone actually believes you as follows: No. Realism asserts that physical things do not contract except for obvious natural reasons. Same for the distances between objects, as immediately above. "Time dilation" refers to clocks slowing down in different circumstances. The "physical process" of "ticking" slows down, and probably all physical processes in the same circumstances as the clocks. Time is not "something" that slows down. If gravity "curves spacetime" then the obvious ontological question is, "What is IT that gravity curves." Obviously the trajectories of objects are curved by gravity. What does "spacetime curvature" add to that fact? (Nothing.) You also said: We all know that the distance between earth and sun changes over time because of the elliptical orbit.* The question here is whether it also changes with observational frame, called "length contraction." Then again you invoke the magic of the spacetime (or rabbit pelt) interval, s and say that "it", "actual distance" doesn't change with different observational frames but "delta x" and delta t "might" change. But delta x is the spatial distance between two events (bodies, in the common vernacular), and it might change with a different FOR? How exactly does this theory make sense in regard to the earth getting closer to the sun in the "length contraction" way. (Ref: * above.)

Ref: "That" being my, And my: ... was just a reminder that GR takes "spacetime" and "makes something of it" besides a place holder (a 'whatever') for SR math. Ontologists are picky about assertions that spacetime is curved by gravity even though it arguably remains a "non-entity." So far so good. Right... (insert math symbols for purpose of calculation... fine...) Then you say: Fine. The distance between them now is the distance between them now. The repetition gains nothing and the math looks irrelevant to the meaning. Clearly. The distance changes over time in an elliptical orbit, whether or not you call it a spacetime interval or a rabbit pelt interval. Darn! It was all going so well, and we all agreed until you said, "Even if the distance is contracted..." Does that mean, “even if earth and sun move closer together as earth moves in its elliptical orbit” ... or does it refer to the more esoteric meaning of "length contraction, as per SR theory " that the distance gets shorter" for some other reason, like observational (FOR) differences? In other words (realism), does the actual distance change with different observational frames or not? Realism says, "not."

As a realist, I always try to understand what these terms mean as descriptions of the observable world. A “spacetime interval” as pertaining to a tie-died rabbit pelt would be a real challenge to one trying to make sense of the phrase! An interval is elapsed time as objects move through space, as I understand the relationship between space and time and the word “interval.” And how about spacetime as that medium curved by gravity in general relativity theory? What curves besides object’s trajectories? Just to sort out the meaning of words more clearly, would you object to a translation of the common use of "event" in physics to mean "object", and the application of the word "event" to that which happens as things move? Then we could speak of the distance between objects at a given time as they both move, either closer or further apart. Like "right now", earth IS exactly (whatever) distance from the sun, though that distance varyies with earth's position in elliptical orbit. I am describing objects and their movements as time elapses in the real world in concrete terms without automatic assumption of the special theoretical lingo relativity theorists use, as you do above, as in "the invariance of the interval." Then what would your second paragraph mean in my translated terms? Does it mean that any two observers will agree on the above "right now" earth-sun distance, "no matter what...?" And when you say, "The spatial and temporal separations might differ between frames,but the interval does not...", doesn't that mean that different FORs will "see" that "right now" distance differently, while the "rabbit pelt interval" remains invariant, the objective, true measurement? All one needs is a magic word to get at the "real distance?" Please assume for a moment, for the sake of my argument that there is no "temporal separation" in the present take on that distance, from whatever frame, because "time" is not different in different locations, not an entity, even though clocks will show different times 'as seen from another frame.' (Now being simultaneous for all frames everywhere in this argument, even in the face of relativity's "lack of simultaneity" dictum to the contrary.) Now to back up to swansont's tedious criticisms (without specifics, as usual): To my: You reply: Again, labeling as “errors” doesn’t make (whatever?) wrong, and you avoid yet again my distinction between idealism and realism. Seems you consider argument by labeling the apponent wrong, and name calling (crackpot and amateurish, as below) as valid forms. You challenge: No. I have said repeatedly that I was using simple conditional, “if, then” logic without a misplaced third element, which makes a two element syllogism absurdly wrong (as illustrated by Wikipedia on syllogisms.) You re-cast my conditional as a syllogism and claimed that I had introduced a third element, which I had not. You: More name calling, which simply and obviously demonstrates how vacuous your argument remains. Very pedantic and lame if intended as a rebuttal of my last “either, or.”... Something like, ... Either Earth has a 1000 mile or so diameter or it doesn’t. Background, in "if, then" format: If there is no preferred frame of reference, then the above description is equally as valid as the extremely well verified 8000 mile diameter. If Earth's diameter is, in fact around 8000 miles, then there is a preferred frame of reference, namely at rest with the object measured. Or, more generally, either the world/cosmos is real and has properties intrinsic and independent of measurement, or it doesn’t, and the world’s reality depends on how (from what frame of reference) it is measure. I don't expect a rebuttal, since you have not been able to follow this simple logic before. Edit: I am speaking in the general terms of idealism vs realism here, about "the world." I know you have said that some properties are intrinsic (not idealism... good for you!),and some are not. You use length (and by implication, Earth's diameter) as an example of a property which is not intrinsic. This does in fact claim that earth's diameter depends on the frame of reference from which it is observed. So either Earth doesn't have an intrinsic shape independent of measurement, or nobody knows what its correct shape/ diameter is. Both propositions are equally absurd according to realism/naturalism. And either assertion would make you an idealist. Of course, “all attributes are intrinsic” does NOT equal “no attributes are intrinsic.” “ not "all a are b" = "no a are b"... is obviously false. But I did not assert either (obviously stupid) argument, as yet again illustrated above.

...Assuming "spacetime" as an established fact. ... Ignoring my whole argument (and all cited references) to the contrary. I cite Brown and Pooley's "Minkowski's Spacetime: a glorious non-entity" and Dieks' two volumes of papers from the conferences of the International Society for the Advanced Study of Spacetime. this forum, and you, case in point, ignore it all and, like most texts and websites on relativity, speak of spacetime as a given. Now back to mainstream spacetime for a moment, a la Wikipedia: The ontology of time (see my thread on that... in "Speculations") does not grant "it", time, the status of an entity that "combines with space." It remains, as per my argument, the 'event duration of physical events.' And space remains empty volume until evidence that it too as a malleable medium is established. I agree that the "universe has three dimensions of space and one dimension of time," though I would not call the time required for all movement a "dimension." Now to the "rotation" of the "spacetime manifold", quoting Bartelby.com on Minkowski’s Four Dimensional Space: (my bold)So, from my argument, we have a "mathematical model", a coordinate system based on a non-entity, spacetime with an imaginary time coordinate (which, in the real world simply accounts for object's movements through 3-D space, simple volume)... "rotating." Then, as "explained" by Cap 'n R, we can look at our theoretical manifold from any angle of rotation and "see spacetime" as quite different from different frames of reference. And we can slice it up and find its contents in any number of creative arrangements. These are abstract concepts, and easily imaged on computer screens. But how does all of that relate to "the real cosmos" of space with stuff in it moving around as "time elapses?" Then back again to continue the Wiki quote on spacetime: How convenient for physics, but what are the referents in the real world? Again, if space and time don't exist without objects moving around (paraphrased Einstein), what is spacetime anyway? Event duration doesn't exist without events. I disagree with the disappearance of space. "No objects" leaves empty space. Anyway, then you are off and running on synchronized clocks without having addressed any of the above. Then to "Things that do depend on frames of reference:" Argument against: If there were no intelligent life observing cosmos from different frames of reference, objects would still be moving, and that requires "time" even if there were no clocks measuring any/all such event duration. The (moving) positions of all objects in space would remain "as is" regardless of any theoretical frame of reference from which they are observed. The above argument still applies. Observation from different frames does not change the position or elapsed time for movement of objects in the real-space cosmos, regardless of how we manipulate coordinate systems. Now back to basic geometry: I'd need link or directions to that example, and the typo above loses the sense of it.("Two dimensions of a circle, I presume.) What z axis? Conventionally, a plane (circle in this case) has two dimensions, x & y. Rotate it through 3-D space (the z axis) and you eventually describe a sphere of the same radius as the 2-D circle. I have considered the space-time interval in detail above and "spacetime" as a 4-D "invariant" coordinate system also in detail above, as per criticisms of "it." As per the "z axis" of a 2-D (x-y dimensional plane), please study, if you have not already, the frequently cited (by me) paper by Kelley Ross, The Ontology and Cosmology of Non-Euclidean Geometry. You take for granted that non-Euclidean is now the one and only established and factual version of space and time and spacetime and geometry in general. I have disagreed in all my threads here. I present the argument for realism/naturalism that the reality of the world/cosmos does not depend on how it is observed, from whatever frame of reference. Specifically, earth is not closer than 93 million miles from the sun just because a certain extreme frame of reference might see it that way... (yes, over and over.) Relativity has its special language, "spatial intervals" in which time and space are theoretically combined, but that does not mean that the AU changes with every extreme in frame of reference from which it is observed. In the real world the elliptical orbit makes the trivial changes in that distance happen, and the AU averages that variation. That "consensus" (not a criterion for "factual") is not shared by the many critics I've cited, including those in this post. And I have no beef with 3-D space as simple volume and time as above. That version of cosmos does not include either the morphing of earth, the AU, and the meter rod to suit the 4-D theory, nor does it support the claim that there is no way to know the actual, intrinsic (realist terms) dimensions of the three cases above. This is not a "false dichotomy." Earth has an 8000 or so mile diameter or it doesn't... in spite of the claim that from a certain extreme frame of reference it might be measured as only 1000 miles... or "it *is* a 1000 mile diameter... for that frame of reference." I just did, though I included my other two favorite examples above as well. Even Lorentz can not transform the earth into a severely oblate spheroid. The entire scientific community knows better than that. Cap 'n R said here awhile back that length contraction is not about objects changing lengths (or shapes, with contracted diameters), but rather that there is no way of telling which frame of reference is correct. (Paraphrased. Please correct me if this misrepresents you, Cap 'n.) He illustrated this with many creative thought experiments, even though there is no actual experimental verification of large scale length contraction... unless you grant that "for a muon" ( as an equally valid frame of reference) the atmosphere is way less than 200 miles through, based on their longer than expected lifespan... "time dilated" resulting in a way shorter, "length contracted" distance traveled. Finally, motivated by my recent arguments with Cap 'n R on SR and the (so far agreed) constant speed of light, I have been studying light experiments more vigorously lately. I've begun to wonder how certain it is that light has zero "resting mass." For one thing, there are no "resting" photons, and their moving momentum acts like mass. Lasers recoil when fired. Solar wind "pushes things" through space. In the "box of mirrors" experiment, it gains resting inertia with laser beams bouncing around inside, as if it gained mass. Then there is the "questioning authority" from other sources. One example (not having checked his credentials): http://o.castera.free.fr/pdf/onemorederivation.pdf Jean-Marc Levy-Leblond: . My bold. Just an avenue that I am exploring, though I have agreed (maybe prematurely) to constant 'C' after reviewing the Michelson/ Morley experiment and summaries of more contemporary verifications. Well, I'll quit before this becomes a book- length post. Gone for the weekend again.

Swansont: Which observations do not depend on frame of reference? You assert that you know better than I what I understand. Are you psychic? Or does your expertise in physics make you an expert in the philosophy of science pertaining to idealism vs realism. I have not seen posted evidence of that. Your persistent disclaimers of my arguments, like "strawman, strawman!" and "false dichotomy" (several times) does you no credit as a philosopher or logician. Neither did your mistaking my simple conditional, "if, then" logic, with two elements, for a syllogism with a stupidly inserted third (Wikipedia version*) and then criticizing me for introducing an extra element, which I had not. * Maybe you are over your head in trying to argue logic and philosophy. Just a possibility to consider.