owl

Iggy: "But, the "correct" answer that you got conflicts with another view you have concerning the speed of light. The two views that you have are mutually exclusive. It is, therefore, impossible for your view of the world to be correct." Rather than your usual cryptic challenges assuming superior knowledge without explicit explanation in each of your "tests," please explain in whatever detail it takes exactly what you mean above, and I will give another try at both understanding what you mean and explaining what I mean. Also, you said: 'The answer is "those facts are correct and true in earth's reference frame". I will be extremely careful with this question. Do you believe, and does relativity assert, that earth and sun constantly move closer together and further apart (not counting the variation in distance due to the elliptical orbit) with all possible different frames of reference? You say: ""Perspective" is inaccurate. Length varies with velocity." Consider a virtual "rod," not physically mutable by compacting in extreme accelleration or even "spagettification" as it is sucked into a black hole. How could changes in velocity change its length. This is just a reality check, from my perspective, on what you (and relativity)mean by "length varies with velocity" if not simply the above extremes of compacting and stretching. You say, "I agree, and would add that even as purely philosophical views, they cannot be correct. Owl's views are not consistent with themselves making their validity impossible." How, exactly, do you see the philosophy of subjective idealism inherent relativity, which I have expounded in detail, as "incorrect" and internally inconsistent. An actual dialogue requires specifics, not just empty accusations without details, such as you have pontificated here in the name of the doctrine of relativity.

The fact sheet I quoted already took into account the variation in earth-sun distance due to the elliptical orbit. But at any given moment, the variation from the average (about 93 million miles) is known. So, the answer is, "yes," you and Iggy do deny these facts and also insist that the length of rods actually varies with the perspective from which they are seen. Fine. This puts relativity squarely in the camp of subjective idealism, subscribing to the absurd implications of same: namely that there is no objective world/cosmos existing in an of itself, independent from observational frame of reference. And, technically, those who hold fast to that philosophy will say, "Yes, my world does cease to exist everytime I blink.... or the old classic, "When a tree falls in the forest it makes no sound unless it is heard." (Aside from whatever creatures might hear it, it obviosly creates sound waves in the air whether ot not percieved by any "creatures" including relativity theorists. I think this will conclude my little exposition on the philosophical basis of relativity theory. I'm tired of hammering on it, and no one here cares about the possibility of a real cosmos independent of information about it carried by light and other lightspeed (electromagnetic) information carriers. I still have have no problem with, generally speaking, "signal delay" variance for who sees what and when differently. But that certainly does not make earth and sun vary in actual distance between them, just because different FOR perspectives see it differently. Again all real varience there is due to the elliptical orbit. Subjective idealism, see. Enough already.

I "dare" to "think outside the frame" intrinsic to relativity theory. My sense is that the cosmos is an objective reality independent of our measurements from different frames of reference. The facts about sun-to-earth distance cited above remain facts in an objective sense which transcends the "thought experiments" so familiar (even dogmatic) to relativity theory. No, "Virginia," aliens approaching our solar system, having a different frame of reference as they would, will not change the facts cited above. (It's almost like a cult in denial of an objective cosmos, now that relativity's Frame of Reference doctrine dominates sceince. Philosopically, this is subjective idealism with FOR as the "subject" defining "reality."

Yes, "very", thanks. I was keeping up with string theory all through its "formative years" up through its integration of all five (?) versions of strings into one unifying "membrane" when "M-theory" was born. Funny thing was, the guy who came up with the eleventh "dimension" which, they say was the integrating concept, was previously hooted out of the scientific community for such an off-the-wall "dimension", then came back in glory and splendor as the father of M-theory with that final 11th "dimension." (Or are there more like 26 "dimensions" now... maybe just the lunatic fringe of this metaphysical and very "far out" speculative cosmology. Anyway, I don't have much patience with Steinhardt and Turok's "Eureka!" revelation that membranes (made of infinitessimally small, never to be seen strings) clapping together create new "universes." BTW, I really enjoyed the way Hawking abandoned his primordial singularity theory of cosmic origin and endorsed the M-theory boys' "new book" a couple of years ago. I had given Hawking a bad time about his singularity theory a few months before his "conversion"... this on another science forum. He and his staff might have seen it... or not. His "infinite mass density in a point of zero volume" was the most absurd and unintelligent "science" I had ever encountered at the time. Any way that's the meaning of speculative cosmology... we don't know. But some seem more "reasonable" than others. Occam's razor would cut out most of M-theory's "dimensions."

Thanks to everyone for replies so far. First, to the above: Maybe "problem" is the wrong word for the concept of "something out of nothing." That it makes to sense to an intelligent mind is a... 'challenge' for me. As opposed to religious belief, science/cosmology must intelligently consider cosmic origin (or perpetual/eternal existence)... as an alternative to "Duh, lets just say that it "it manifest out of nothing." No, none of us, of course have had a direct experience of "where it all came from." Cosmology by its very nature is speculative, but that doesn't keep the intellectual curosity of "scientists" of all kinds from such specualtion. And there is no difference that I can see between an agent "God" creating "it all" out of nothing* and the "science" of everything out of nothing (*like when "darkness was on the face of the deep" and then "He said, Let there be light"... and eventually everything else magically appeared. Regarding your statement: " Similarly, "the concept of 'before the big bang' is nonsensical because time emerged in the big bang" is not a problem either. There could be an eternally cycling series of bangs, but why does that make any more sense than a spontaneous event in which time and space emerged from nothing?"... Please re-read my last opening statement. Let's not start off by reifying "time"... a big pet peeve of mine! Get a stopwatch. Click it twice. "Time" is the duration between the two instants, the two "clicks." Don't lets debate "time" here. (Yes, it will make a difference what inertial environment you and your stopwatch are in, and another one in a different such environment will get a different "duration of time" beetween clicks.) And, I'm talking about where the visible cosmos came from, not the more esoteric concepts of space and time. (The former I see as empty volume, considered apart from what exists in that volume.) So, everything continually existing and going through perpetual Bang/Crunch cycles makes infinitely more sense to me than the magic of spontaneous manifestation from nothingness.

Hi all, I looked around, but maybe I missed it if this topic exists somewhere on these boards. I'm not so much interested in debating the dynamics of the bang or the assertion that it was "not an explosion of matter out into empty space" (but rather an "expansion of space itself"... which doesn't really address what "space itself" is besides empty volume...) I'm interested in how science deals with the "something out of nothing" problem. Such an assertion seems to me no different than the bogus religious belief that it all came out of "God's Magic Hat" if I may speak tongue in cheek as an amateur scientist with NO religious beliefs. I like an oscillating (bang/crunch) model, because at least it affirms the law of conservation of matter/energy... that "it all" came back (imploded) from the last bang to "crunch" or "bounce" and start another in an ongoing, perpetual two phase cycle. I know that lack of enough matter to effect such a gravitational reversal is often cited, along with entropy as reasons this model will not work. But of course, more matter is being discovered all the time... ever more stuff which doesn't emit or reflect (from our perspective) light. So the verdict, "not enough mass for the required gravitational reversal"... is at the very least a premature judgement. And the entropy argument is complicated, but also not really a death sentence for the oscillating model... if "it all" comes back... in all its forms... no matter how "thinly dispersed. But enough for now. Oh,... can we avoid the "beginning of time" argument in this?... I mean, to at least to give a perpetually, eternally cycling model a chance to be considered. Thanks.

Leemur, I agree with you about the language around "time." All relativity texts makes "it" into an entity in students mind, and then they "grow up to be" relativity theorists who weave "it" into the famous "fabric" spacetime with space also some kind of entity, rather than just the volume in which everything (masses and forces) exist and move. They all would have flunked their prep science classes in relativity without such acqiescence. And nobody here wants to talk about the big transition, long ago, by which 3-D space somehow gained a fourth dimension and enough "entity-hood" to take shapes, expand, curve, etc. (From Euclid to "non.") And "the model/metric" is not the territory the map describes. Do I repeat? Very well, I do repeat, hoping eventually for a direct answer without smoke and mirrors and "If you only understood the math..." kinds of answers... or "you just don't get relativity." Look at how the sci-fi of "time travel" took on the pseudo-respectability of science. See latest post in that thread. So much for the past being gone (no longer present) and the future simply not present yet? People will believe anything if repectable geniuses, like the architects of relativity endorse it. In fact you will be eventually "Boo-ed" out of any science forum if you challenge the ontological status of space, time, and spacetime. I think that is enough from me on this soapbox... unless someone wants to explain that fourth spatial axis... or... what kind of a thing "time" is.

Me: I was using lightspeed as a constant measure of distance and making the point that a speeding alien's frame of reference is not going to change the actual, objective distance between sun and earth... You (Iggy)"Which is completely wrong." I know you know this but we have a complete failure of communication here, so I am going to cite the well known facts about distance to the sun... which, to my point, does not change with changes in frame of reference, like that of the alien above. From Answers.com: "What is the distance from earth to the sun? ... Answer The average distance between the sun and the earth is 149 million kilometers (93 million miles). Because of earth's elliptical orbit around the sun, the distance changes over the course of a year (one complete orbit of the sun): We are closest at perihelion, during winter in the Northern Hemisphere (around January 3rd) at the minimum distance of 147 million km (91 million miles). We are farthest away at aphelion, during summer in the Northern Hemisphere (around July 4th) at the maximum distance of 152 million km (94.5 million miles). Light from the sun takes roughly 8 minutes to reach the earth traveling, of course, at the speed of light. Therefore you can say the sun is 8 light minutes away from the earth, just as you can say a star is light years away. The distance from the sun to the earth is one Astronomical Unit (AU). An AU, as defined by the International Astronomical Union, is the mean distance between the sun and the earth. That mean (or average) distance is about 149 million km (93 million miles)." The above is what I am calling the actual, objective distance to the sun, regardless of relativity. Let's start at square one. Do You deny the above facts?

Iggy, As I said above (the philosophical question you are avoiding): On the other hand, if cosmos exists in and of itself regardless of FOR measurements/observations, which I believe is true, then the opposite cannot be true, i.e., that observational perspective changes distances observed... which is pure subjective idealism. I see how my quote above confuses the issue. I just meant that we have a universal instument of distance measure in that lightspeed is constant, so, for instance we can say that the sun is just over eight light minutes away from earth, and that is not going to change because some traveler is approaching our system at near lightspeed and having to run the well proven relativity formulae to correct for the distortion created by their speed/vector. (End if reiteration.) I was using lightspeed as a constant measure of distance and making the point that a speeding alien's frame of reference is not going to change the actual, objective distance between sun and earth... the subjective idealism point I have relentlessly tried to make here while you throw SR thought experiments at me and demand that I do the calculations. So now you throw another one at me: "Here it is in a simplified form: someone is moving left of you at 540 million miles per hour and someone else is moving to your right at 540 million miles per hour. How fast is the second person moving away from the first person? How fast, in other words, would the first person measure or say that the second person is moving away from himself? Your view of reality involves notions that are not consistent with each other which makes it impossible for you to answer the question I've just asked." (I said I would not play that anymore, but I will offer a deal: You answer my challenge and I will do the calculations required above.) Even I can do elementary math, but of course this another SR trick question since nothing can travel faster that lightspeed, which is 671 million miles an hour. So if I add the 540 million mph of the guy going away to my left onto the 540 million mph of the guy going away to my right... I get a billion and 80million mph.... which somewhat exeeds the universal speed limit.... so.... what is your point given that I know what SR means? And will you now agree that earth stays a bit over eight lights minutes from the sun no matter what speeding travelers see from "far out" frames of reference? And how about those rods? Do they "really" contract in length according to observational frame of reference? Ans: Of course not. If "yes" then, by the same principle, namely subjective idealism, your world will disappear every time you blink! You get my point?

Just a bump here, fishing for comments on my last post before I give up on the inquiry into the difference between "modeling" and the cosmos modeled... and that elusive fourth axis/dimension of space assumed by non-Euclideans as an essential part of relativity. And I'm fine with "time" being left at event duration (between any two instants) as long as relativity doesn't insist on making an entity out of it, as the label "time dilation" implies. Just clocks ticking at different rates in different inertial environments... fine.

Iggy: "Without understanding science, at least at an elementary level, you cannot be good at philosophy of science." Here is a little philosophy of science for you... though you continue to avoid comment on it: Without understanding that frames of reference do not shorten or lengthen "time" or "distance" or create an entity "spacetime"... that cosmos is as it is idependent of frames of reference, you end up being a a subjective idealist without even knowing it, so you continue to avoid this aspect of relativity as a case of subjective idealism. I will not again go into SR with you. I've seen similar thought experiments dozens of times over the years. Please do not think you have found a new way to express it. We all know that the speed of light is constant no matter the speed of a given lightsource... either in the direction of the source's travel or "looking back" from whence it came. This does not mean that relative FOR makes distances change, as the subjective idealism aspect of relativity asserts. Like it or not, this is a "philosophy of science" issue, which you still refuse to engage. I, like most people interested in SR, have asked myself why light does not gain speed in an "add-on" way with its speeding source. My best "explanation" is that light can not be "pushed" faster... ever. This must have to do with its lack of mass... nothing to "push against." But this leaves me wondering why lasers have recoil when fired and why the old "box of mirrors" gains inertia, just as if it gained mass, when light is introduced to bounce around inside. I am very curious and open to explanation in either or both cases. But I will not play the game of "Owl obviously misunderstands SR" any further. Thanks for the conversation. If you decide to answer my philosophical challenge, please do so. Edit: BTW the calculations you continue to demand do not address the philosophical issue here... nor, in more general terms, does the math confer understanding any more than observation creates that which is observed.

First, I agree that this is off topic, but if no objection, I'll continue for the sake of convenience. (BTW, I still haven't figured out individual quote boxes but intend to review the tutorial.) Iggy wrote: Philosophy of science involves interpreting scientific theories. To interpret a theory, a working understanding of the theory is necessary. I believe you need someone to be brutally honest. You do not have even an elementary understanding of relativity. Your posts in this thread show that you would not be able to use the theory and that you don’t understand what makes the theory necessary or what purpose it serves. A few posts ago you said that the distance between objects is constant in relativity when expressed in light units because the speed of light is constant. In truth, a constant speed of light makes the opposite true. With that kind of misunderstanding of the purpose and application of the theory, you can’t expect a good philosophical interpretation." I am much better at philosophy of science, as per the subjective idealism inquiry as an implied basis of FOR relativity... than at technical discourse. I do understand that light speed stays constant regardless of the speed of a given lightsource. I get it but can only guess why... someting lame like "light can not be pushed." On the other hand, if cosmos exists in and of itself regardless of FOR measurements/observations, which I believe is true, then the opposite cannot be true, i.e., that observational perspective changes distances observed... which is pure subjective idealism. I see how my quote above confuses the issue. I just meant that we have a universal instument of distance measure in that lightspeed is constant, so, for instance we can say that the sun is just over eight light minutes away from earth, and that is not going to change because some traveler is is approaching our system at near lightspeed and having to run the well proven relativity formulae to correct for the distortion created by their speed/vector. As for the ball players: Of course in the first instance the ball is going 10mph relative to the runner, whose speed is 10 mph, tho the ball is is going 20mph relative to the catcher or the ground. In the second case, SR of course applies, and light is still going at 'C' relative to the runner, who is going 1/2 lightspeed. But the distance between bases does not change in either scenario unless you subscribe to the FOR version of subjective idealism I have proposed as appliicable to relativity. So far your examples are well worn and frankly quite pedantic, not to say insulting. You say: "I won’t get into a philosophical debate, but special relativity really doesn’t suggest subjective idealism. " How so... or why not? Now to the sliced tomato... also quite pedantic. You have two dimensional slices of a 3-D object. Fine. But then you stretch the metaphore as follows: "In relativity, frames of reference are three dimensional slices through ‘four dimensional’ space-time. Space time is the same even if all the three dimensional slices, or frames of reference, are different. If you understood how and why that is true then you would also understand that relativity offers an objective reality independent of the various differing perceptions of reality that come with different frames of reference. You ask if it denies a cosmos independent of observational frames of reference and the answer is that it establishes exactly the opposite. This is what Dr. Rocket has been talking about." Space-time is not an established entity, though it is constantly/routinely treated as such everywhere in relativity. My essay on the subject of that ontology is still under house rule gag order. (I do understand why and OK with the reasoning.) Space can be fully defined as volume with three coordinates. A fourth axis for space remains a metaphysical concept. Time is a factor (if not a "dimension") because all movement can be said to happen with duration, or "through time." I have often cited an essay by Kelley Ross on the Ontology and Cosmology of Non-Euclidean Geometry in this regard. See my spacetime ontology thread in this regard. If your second paragraph is true then how is "length contraction" explained? No rod lengths staying the same there. Rod length, like distances between cosmic bodies, according to my understanding of relativity are supposed to change with changes in FOR. Seems to contradict your paragraph above. Please explain.

It seems my fundamental inquiry is still not clear. Here it is again. My most avid interest in science is the philosophy by which relativity claims that 'frame of reference' (FOR) is the ultimate criterion for what is real and true of the cosmos. Accordingly, our clocking time becomes the operational definition of what time IS. (No philosophical consideration of whether time is an artifact of measurement or an entity with an independent existence all by itself. Likewise, "space,"... since the conceptual leap beyond common sense Euclidean space... now has 'curvature' and expands, etc., as if it were, like time, an actual entity. So, as a philosopher of science, I say that relativity is based on a form of subjective idealism... like that of Berkely and Hume but for the 'subject' being the abstract "observer" or frame of reference. Funny that "FOR" also applies to the common thought experiments that relativity theorists love... i.e., "for observer A vs for observer B. there is no "for" an objective perspective transcending local viewpoints... tho we can easily imagine (as a "thought experiment" thinking outside the frames) that cosmos exists independently of local observational perspectives. In a nutshell, I am asking, as above... does relativity deny a cosmos independent of observational frames of reference? Iggy: "In special relativity, the speed of light is constant. The distance between the two galaxies is not constant." I take this to assert that there is no "actual, objective distance" between here and Andromeda... nor between here and the sun, because "it all depends on frame of reference." Just to be absolutely clear, is this what you and relativity are claiming? If so are you and all relativity theorists philosophically persuaded to the belief in subjective idealism. A direct answer would be very much appreciated. edited to try cleaning up my notepad paste job, and one correction.

The raisin bread model, like the spacetime model, came out of someone's mind. The ontological question with any such model is "How well does the map fit the territory?" As a coordinate system we can locate whatever objects in space by their coodinates in a three axis system applied to any volume of space, and we can describe object movement with various vectors through time. We can also *conceptually expand the space* by devising a larger model/coordinate system and extend vector tracking through a longer period of time. Neither expansion is an "expansion of space or time" per se. The model is not the cosmos described by the model. BTW, if we add a fouth axis to space it must be explained, as volume is already described by just three. And "extrinsic curvature relative to one manifold" vs "intrinsic curvature relative to another manifold" does not, by virtue of the language/concept make non-Euclidean "curvature of space" someting real in the cosmos... besides the model/concept, that is. Neither does saying that parallel lines intersect in some esoteric mathematical "infinity" make it so.... or that now that we have "curved space" (in our minds anyway) that the shortest distance between to points is no longer a straight line... curved as they now are in our non-Euclidean model.

OK, so my "thought experiment" above gets no comment, based apparently on the premise... yes, as I said, relativity does deny a cosmos independent of observational frames of reference. And if you look up the distance to Andromeda in lightyears, instead of finding something in the neighborhood of 2.5 million, we should get the fine print version... "depending on observational frame of reference." By some magic, if a traveler is going there at just under the speed of light, somehow he can make the journey in about 70.7 times less that light going at full speed. Neat trick! Maybe an explanation is just too much to expect.... or is "all is relative, there is no 'objective cosmos'"... the explanation? Yes, relativity is based on subjective idealism with the subject being the frame of reference and no possibility of an "objective perspective" like the more obvious distance to the sun at just over eight light minutes.

Hi folks, I've been sick, sometimes better, sometimes "worser" for awhile now, so I'm left with a lot of loose ends here which I could not follow up on with good speed. Many gaps for me still remain from my discussions with Spyman and Iggy starting in page two. But rather than try to bactrack to each point for which I need clarification, I'll go to your point, Iggy, on the distance to Andromeda. You say (sorry, I don't have the single quote tool down yet): "If a person travels the distance with a velocity 0.9999c relative to the galaxy then it will take them 35,357.99 years. Distance is speed times time. The distance to the Andromeda galaxy is therefore 0.9999 lightyears / year times 35,357.99 years = 35,354.5 light years. We on earth measure the distance at 2.5 million light years." Am I confused (as you have previously assumed) or does relativity deny a cosmos independent of observational frames of reference? (I like that FOR also applies to "for abserver A vs for observer B" but never mentions a "beyond the frames" perspective... the actual distance in an objective sense. As I said to Spyman earlier, seems to me such an objectve distance can be designated by the universal constant 'C', and since we use years as time units and light years as a standard cosmic distance measure, that 2.5 million of them is the actual distance. Since your travelers are going nearly lightspeed, not faster than light by whatever multiple of the difference and fraction of journey time, how is it that the "FOR" of the travelers is now on equal footing with standard measure, as science uses to designate all cosmic distances? This makes "FOR" and relativity into to a kind of subjective idealism, with FOR as the subject. You have previously misunderstood my philosopical rejection of such idealism as a misunderstanding of relativity. This is usually the case for those who disagree on this very fundamental level. If you disagree, then you don't understand. Even my "Thought experiment" is dismissed as another misunderstanding of relativity. (If there were no intelligent life, light speed would still be constant and take precisely the same time to travel between objects... with no observers... no frames of reference.) Rods (naurally occurring, let's say!) would not keep changing length either, as this form of subjective idealism claims. There were other gaps of great interest to me, but I'm out of steam again for now. Oh... the "What is space?" question. Please tell me how this is wrong. A line describes one dimension... a plane, two... and a volume is three dimensional. Space is volume regardless of what exists in space, where, and how moving. There can be no "end of space,*" so, beyond all "defined volumes" is infinite, endless space.(See my comments to spyman in page two in this regard. What boundary... what beyond any imagined boundary?) There is no "it" to space. So where did the non-Euclidean concept of curved space and four dimensional space come from. (Rhetorical question! I've studied the transition from Euclid to beyond in depth for years.) I line requires a plane to display curvature. A plane requires volume for same. There is no pretending that great circles or arcs therof are "straight lines" by re-defining curvature as intrinsic to this manifold and extrinsic to that manifold. We can not devise a four dimensional space by a trick of language. Volume has three axes. What would a fourth designate in "the real world?" My fever is climbing again. (Figuratively and literally.) Gotta go. Appreciated the mental exercise.

Just to be clear about my statement about gravitational "action at a distance": (To put it simply, mass curving spacetime (as an abstract metric or as a substantive medium) is not the only explanation for how gravity works. The virtual particles of quantum mechanics is another, but this introduces the quandry of mystery called "action at a distance" for which there is no explanation.) I accept that there is no explanation for how gravity works over distance way more easily than I can accept the metaphysical invention of the mystery medium spacetime as something that is curved by gravity and so "explains" the effect of gravity on objects. This is not to deny that the concept is a handy tool/model for relativity in its obviously improved ability to predict object movement. All that would be required is the honest labeling of the conceptual model "spacetime" as such, rather than the ubiquitous phrase "curved spacetime" as if "it" were actually something curved.I am not trying to "bring down relativity" as some have said elsewhere. And calling this an "ontology tangent," (Swansont) is quite unfair, though it seems to reflect the bias of this site. I am attempting to bring the discussion of spacetime ontology to these boards. It seems as if my intoduction of Ross's ontology of Non-Euclidean geometry and Deiks's comments on papers from the spacetime ontology conferences are being ignored. YdoaPs's statement: "The mathematical component IS the conceptual component; it's just a different(more accurate) language in which the concept is expressed."... doesn't even address the ontology, the "what is happening in nature" part of Ross's statement: "Just because the math works doesn't mean that we understand what is happening in nature. Every physical theory has a mathematical component and a conceptual component, but these two are often confused. Many speak as though the mathematical component confers understanding..." With all due respect, I think the last sentence applies to you, ydoaPs. And I think the same honesty-in-labeling applies to time, as I agreed with you above, Marat. Science would take a great leap toward such honesty if "time dilation" wre not constantly repeated designating time, at face value, as someting that dilates But it seems that the majority of relativity theorists have taken their textbooks at "face value" and actually do believe that time is somehting that changes in each and every different inertial environment... i.e., not just changes in the clocks. Owl

Regarding your statement: ..."'in mainstream science there is no space inside or outside of the rubber, instead all dimensions of space are on the surface, like a hypersphere." What would you say would be inside and outside this "baloon?" If "nothing" then that is empty space. Can you imagine an "end of space?" What boundary might describe such an "end?" What might be beyond that imagined boundary? More space, ad infinitum is the only possible answer that I can find. Now to your question,"Can you explain why we wouldn't be able to determine the direction towards the centre in the first example?" Yes. If the visible cosmos is within one small sphere of "rubber" the whole "membrane" of which is a vastly larger cosmos that we can see, and the whole thing is expanding outward from the bang, all we can see is local movement, neither beyond the inside or outside of the "membrane." I think most of you other questions are answered in what I just posted in the "Ontology of Time" thread. No, not an optical illusion but rather that the world/cosmos has an objective existence without the limitations of our measurements, so the latter do not describe "reality as it is." A rod may be physically compacted by sufficient accelleration, but I don't think that is what you mean. Observing it change length does not actually make it change length, which is what I think relativity (and you) assert. That is the subjective idealism component of my criticism of relativity, philosopically speaking. The difference in "lifespan" of natural vs labatory muons, for example does not mean that there is some local time environment which is extended in the one case and shortened in another. They just "live longer" (or shorter) in different energy environments. (See my comments on time ontology in the other thread mentioned. I hope this addresses most if not all your questions. BTW, I don't think you responded to my specific questions in previous post. "Yes?"... "Do you agree?" Does cosmos disappear lest we observe it? PS, Re: "A fast moving rod will not only look shorter to us, it will also fit inside a shorter box while it passes..." The same observation (frame of reference) by which the rod looks shorter applies also to the box... or maybe I again misunderstand you. Thanks. Owl

Regarding your second statement, I will (again?) quote Kelley Ross from his Ontology and Cosmology of Non-Euclidean Geometry: "Just because the math works doesn't mean that we understand what is happening in nature. Every physical theory has a mathematical component and a conceptual component, but these two are often confused. Many speak as though the mathematical component confers understanding..." Then to Deiks from the Ontology of Spacetime. He cites cites Brown and Pooley who state that “ …The physical laws do the real explanatory work, not space and time.”… contrasting with (Deiks’ words)” the usual special relativity of Lorentz invariance as a consequence of the symmetry properties of Minkowski spacetime." Deiks summarizes this debate as follows: (If Brown and Pooley are right)…”There is no causal mechanism involved: Spacetime does not send signals to which particles respond. More generally, exactly how does spacetime inform the laws of nature? Failing a detailed account of what the purported explanation consists in, it can hardly be maintained that the existence of space and time is the only plausible conclusion"... The above ontological perspectives are representative of many other papers from the conferences on the ontology of spacetime. To put it simply, mass curving spacetime (as an abstract metric or as a substantive medium) is not the only explanation for how gravity works. The virtual particles of quantum mechanics is another, but this introduces the quandry of mystery called "action at a distance" for which there is no explanation. The trouble with all, "Time is..." statements is that the ontology of time is not a settled debate. You say, "Time is the separation between states," and I say time is the duration of events between two designated instants. Maybe they mean the same thing, but if time is just an artifact of measurement... "time is what clocks measure," then ontologically it is not an agent of or influence on events but just the assignment of "units of time" to event duration. So if space is the volume in which objects and forces exist and move, and time is duration from any one "now" to another, how does that make "spacetime" into a medium with curvature which controls the movement of things observed. I think this is a fair question which deserves an answer from relativity theorists such as yourself. Finally I know that "Observers need not be sentient beings." That is why I have used "frame of reference" synonymously with "observer." Yet, even as an abstract, relativity claims that distances through space vary "for observer A as compared with observer B" as if distance from earth to sun, for instance, were not "objectively" 8+ light minutes... but rather "depends on the observational frame of reference." This is why, relativity can be called subjective idealism, with "subject" being frame of reference, however abstract. Owl I agree.... but for the variety of clocks which can be said to transcend "mechanical action." Still, if "Time is that which clocks measure"... This is a tautology which avoids the question, "What is time?" even tjhough it is still treated as an agent or entity along with space. Owl

This really gets down to the ontology of "spacetime" as a metric, and the question is how well the metric, as an abstract map fits the territory being mapped. What does it mean to say that the magnitude of the entire separation (spacetime metric) changes? What is an individual state... a local "time environment" (with what boundaries) for an indefinite number of individual locations and inertial states? There is a gap here between said abstract "metric" and the matter/energy fields they attempt to describe, and the former is ontologically confused with the latter until ontology clearly sorts it out. The latter is my focus, my avid interest in clarifying at least the language of relativity which calls "time" a variable as well as space/distance, depending on observational perspective, as if there were no objective world/cosmos without our observations, measurements, and timing devices. The whole discussion of the ontology of space, time, and spacetime, is the collective effort to address these questions. I look forward to qualifying for such discussion in the appropriate context, philosophy of science, specifically the above ontology. Thanks. Owl

Yes, Spyman, the difficulty in understanding is mutual, but I do understand your two scenarios above. I will also explain my philosophical difference with the asuumptions implicit in relativity theory. I accept that observation supports a visible cosmos which is isotropic and homgeneous. If the expanding balloon model of cosmos is true, this does not mean that we can see beyond the "thickness" of "rubber" within our local part of the balloon and locate the center of the balloon (locus of the big bang.) Of course we can not. As you implied, even in the first example the rubber of the balloon membrane will have thickness. ("...in the first example the swarm would be spread out like a hollow shell of some thickness,...") It is entirely possible that our cosmic event horizon is embedded wiithin the thickness of material expanding outward omnidirectionally from the bang. As to the subjective idealism "embedded" in relativity theory, which I previously mentioned (that distance varies with observational perspective), here is a thought experiment for you. If there were no intelligent life in the cosmos, we can probably agree that cosmos would not vanish simply because we were not here to observe it. (Yes?) So, the distance between, for instance, earth and sun would remain as is and sunlight would still take over eight seconds to reach earth. (Yes?) Likewise rods of "equal length" would stay equal no matter how they traveled in relation to each other. Again, with no "observer" to invoke relativity, signal delay, and frame of reference difference, the rods themselves would stay the same length. Do you agree? Same for time as for space and distance: Things would move around on their own and all events would happen without our observation and measurement. An earth rotation and orbit would be the same duration without our clocks disagreeing because of inertial differences in their frames of references... as we observe now, calling it "time dilation." Do you see what I'm getting at here? I do not agree with the subjective idealism implicitly embedded in relativity theory. Thanks for the converstion. Looking forward to your reply. Owl

ydoaPs, Thanks for the tutorial link on quoting and the Sider reference on 4-D ondology. Seems I'll have to log 30 posts before I can take my 'ontology of time' inquiry to the philosophy forum. That's OK... I've got time! I did read the three reviews of the Sider book. One comment on the following from the Perrine review: "Four-Dimensionalism holds (roughly) that, just as you have spatial parts--e.g. hands, cells, simples, etc.--you have "temporal" parts. A temporal part is a part of you that exists at a certain time in your existence. A consequence of this view is that, at a particular moment, you don't "wholly" exist, because your existence is spread out in time. (Four-Dimensionalism contrasts with Three-Dimensionalism, which holds that you "wholly exist" at every moment you exist.) It seems quite "far fetched" to assert that we don't fully exist in the ongoing present because our existence is "spread out in time." But I would need to get and read the book to give it a fair review myself. Maybe, eventually. Meanwhile my posts above in this thread give a fair summary of the ontology of time as I see it. I really don't understand your question, "Why must it be more than it is?" My ontological objection to "time dilation" is that the concept gives "time" a reality as an entity that speeds up and slows down rather than just the obvious fact that clocks speed up and slow down in different inertial environments. Thanks for the opportunity to address the ontology of time and space so far. I don't know why there is a 30 post requirement as above, but, of course, I will comply. Owl

Spyman: "Even if space is emptiness and not a medium, it does still exist and have properties like distance. What is distance and how do we know whether the scale we use for measuring it is absolute and not changing?" Maybe I don't understand the question. I assume that we agree on lightspeed as a universal constant (even if the light source is speeding, as per special relativity.) So we we can say that light travels a given distance in a given unit of time. The sun is 8+ light minutes from earth (give or take its position in elliptical orbit.) It is the same distance regardless of time unit used or frame of reference differences among different observers. Relativity stays intact, but that distance doesn't actually vary with observer frame of reference. Me: So, I see the "bang" (by whaterver dynamic) "launching" all cosmic "stuff" outward omni-directionally, so the further out things get, the further they are from each other and from the locus of the bang. You: "If that was the case then we should be able to measure surrounding objects speed and trajectories relative us and find discrepancies with those objects moving outward by our sides as those moving outward in a leading or following position. How do you explain why our observations can't find these discrepancies or the location of the locus? Or do you think that Earth is in the center, or very close to, of the Universe?" I'm sure I don't understand the first two above, just the last. Of course earth is way out from the locus of the bang, like the rest of cosmos "launched" in all directions from the bang. And every bit of "stuff", like fragments from a fireworks display, is getting further from the "launch site" (primordial ball of all-there-is) and from every other bit of stuff. (Your objections to this above make no sense to me.) You: "Do you also reject the theory of Relativity which has so far passed every unambiguous observational and experimental test? If not then how do you concede with length contraction?" No to the first. I reject the reification of space as some thing that expands, curves, and has shape, though the contents of space do so. This is an ontological objection to the treatment of "space itself" as such a malleable medium. As for "length contraction: As a philosopher of science I see this aspect of relativity as subjective idealism*... where the abstract "observer' in each frame of reference is the "subject." (*The belief that the only cosmos/world we can know is what we percieve, and that varies with point of view, inertial frames of reference, etc.) So relativity says that two rods of equal length when side by side change to different lengths when viewed from different frames of reference with signal delay varying what different observers see. Here there is no "objective world" but it actually changes with our perception of it. I am not a subjective idealist and, therfore disagree with this fundamental philosophy within relativity. Same with one rod accellerated and then measured from a different frame of reference. (It stays the same length not matter how, from where, and in what inetial reference frame it is observed. Hope this is clear. Of course, as one who sees relativity as you do, you will not agree. Mine is a philosopical difference with relativity's basic notion of subjective idealism, as above, and with its reification of space, time, and "spacetime." Owl

Swansont wrote: "Clocks "tick" at different rates in different inertial circumstances, as proven by many experiments. does not specifically address the issue of whether it's a mechanical issue of the clock. But this issue has not been ignored — different types of clocks have been tested, and they all show the time dilation effect. So we conclude that the timing changes are due to the effects of relativity. " I'm trying to get at the ontolology of "time," like, what is "it" besides event duration between designated instants? I know that our most sophistcated clocks show what has come to be known as "time dilation," but how is that different than, as above, the fact that they "keep time" differently (slow down or speed up) in different inertial environment Clocks keeping time at different rates is a different issue than asserting that "time itself" is an actual medium/entity which differes in each and every local inertia situation. I hope I'm making this distinction clearly. The ontology of time is a deep subject and relativity does not have a lock on time as a malleable medium in an of "itself," which clocks simply measure. Even the debate about a "global time structure" shed light on the assumption of relativity that local inertial frames of reference are the end all of the nature of time, space and the universe. BTW, I am not advocating that time is a "structure" but more like this: It is now everywhere (ongoing, perpetually), and time is an artifact of measurement, i.e., the duration of a given event between two designated instants. What say you? Respectfully, Owl

What is the difference between these two statements: "Time dilation is true as proven by many experiments." And Clocks "tick" at different rates in different inertial circumstances, as proven by many experiments." BTW, I know that the "lifespan of muons" increases in "different inertial circumstrances" and that GPS clocks require correction according to their different "circumstances"... but this is a question about the ontology of time as a variable entity as contrasted with clocks as variable measuring devices. The standard, matter of fact statement, "Time dilation is true," ignores the above distinction. Owl