owl Posted August 30, 2011 Author Posted August 30, 2011 md65536: owl, where in your false dichotomy would you fit someone who holds the belief that our reality, or some aspect of it, is ontologically independent of our conceptual schemes, linguistic practices, beliefs, etc., but also believes that length is not such an aspect and is instead observationally dependent? Hmmm... would you please rephrase the question? Anyway... It would be a case of "Have you stopped beating your wife?" if I attempted to explain my "false dichotomy." I would "fit someone" of that description (depending on the specific "aspect" of reality they believe is intrinsic or objective ) into a selective sub-category of idealists who grant reality "independent of our conceptual schemes" to all natural phenomena except, for whatever reason, length/diameter of certain objects and distances between objects in the natural, un-measured cosmos.
Schrödinger's hat Posted August 30, 2011 Posted August 30, 2011 (edited) Let's just assume what owl said is right for a moment and see where it gets us (I know, I know, most of you have done this thought experiment long ago, but there are some here reading that haven't), either we come to a logical contradiction, something that disagrees with experiments (such as Michelson Morley) a new prediction, or relativity is illogical. . Let's start with this one: The speed of light is constant -- Owl, could you elaborate on this? Maybe I can clarify my thought experiment: I'm going to use earth time/distance, and ship time/distance just to be clear. Even if they turn out to be the same. We're on earth sitting still. There's an object moving in this world, say a space-ship, at 0.9 times the speed of light. Let's say it's one light second long. A light in the back of the ship turns on. The light will move 1 light second in one second, but the ship moves 0.9 light seconds in that time. So one second after the earth-time the light turns on, the light beam is 0.9 light seconds away from the front of the ship. We've put some equipment or a scientist on the ship, it makes the same measurement. Turns the light on, sees which detectors have lit up 1 ship-second later Owl, according to your model. Will the front of the light beam be: a) 0.1 light seconds along the ship when the moving scientist takes his measurement, or b)1 light second along -- at the front of the ship? Also Owl: If you come on the chat we can discuss this much faster, and I can get an idea of what your model means. Edited August 30, 2011 by Schrödinger's hat
owl Posted August 30, 2011 Author Posted August 30, 2011 What is the ontology of distance? If it's just the space between two points then what is "it" that is expanding to create Hubble expansion? Or is that just another crazy notion like time dilation? (me: Yes.) It seems to me like your efforts to refute spacetime demand more definition of time than space, which you seem to accept as obvious. Please read my comments in the ontology of time thread (in "speculations" at the whim of moderators) and get back to me. I have defined time as event duration of physical processes. Not an entity. Nothing to expand (the meaning of dilation.) Do you agree? To me, space is obviously just 3-D volume on all scales, from between subatomic particles to between galaxies to all the space there is... infinite, in that there is no "end of space." (What boundary?... what beyond that?) Not an expanding mystery medium, even if that is "mainstream science." The space between objects "expands" as things move further apart, not because "space itself is expanding." Just another point from ontology of space... not of interest to physicists who "believe in" the mainstream doctrine of expanding space.
md65536 Posted August 30, 2011 Posted August 30, 2011 I would "fit someone" of that description (depending on the specific "aspect" of reality they believe is intrinsic or objective ) into a selective sub-category of idealists who grant reality "independent of our conceptual schemes" to all natural phenomena except, for whatever reason, length/diameter of certain objects and distances between objects in the natural, un-measured cosmos. Well that answers my question satisfactorily. It implies that a realist accepts the reality of "all natural phenomena" independent of frame of reference, and any exception makes one an idealist. These are not generally accepted definitions of the words realist and idealist. Just as with "time", you are making up your own definitions for things. I have no problem with that; it's just that I was confused by when you were using words I thought you meant some accepted definition. (The false dichotomy is either your "all or nothing" separation between realism vs. idealism, or your arbitrary categorization of specific aspects of reality as subjective or objective. I'm not sure which because you haven't explained which, if any, aspects of reality the categorization depends on.)
swansont Posted August 30, 2011 Posted August 30, 2011 You continue to miss the whole point of this thread, which compares idealism to realism. Realism realizes that the universe has a reality independent of observational frames of reference. No, realism asserts this. It is not borne out by experiment. Science observes from as error-free point of view as possible, makes records and so determines things like the shape or earth... which is not in dispute, accept among eccentrics with an un-verified theory about length contraction. Seeing things as shaped differently from different points of view does not mean that they actually are shaped differently, depending on how you see them. We only have data from one frame of reference. But why choose the earth? if it's true for the earth where (as you conveniently point out) we don't have data, it must also be true for all things. So let's apply this to the realm where we do have data. Nuclei must have an intrinsic shape if this is true. Muons must decay before reaching the earth is this is true. Why does the science tell us otherwise? How many times must I repeat this before you get it. If you disagree, you are an idealist. If you are an idealist, admit it, and I have made the point of this thread's philosophical argument. It is a false dichotomy, based on a false premise. I can "prove" 1=0 if I am allowed to cheat on the rules of math. Same thing. "In forming the argument you have presupposed that length is invariant, and it is not." In saying that it is not, you have presupposed that reality is dependent on how it is observed, which is the argument for idealism. Realism does indeed suppose that things are as they are intrinsically, in the real world, independent of how they are observed. No, I have assumed that what we measure is reality, which is the basis of science.
Cap'n Refsmmat Posted August 30, 2011 Posted August 30, 2011 None that I know of. So how can you conclude that there are vasts amount of evidence to support the claim that Earth will be spherical when we fly past at high speeds? Nobody's ever done it before.
Iggy Posted August 30, 2011 Posted August 30, 2011 Owl has said that the speed of light is constant, that there is a universal now, and that distance does not contract. These things, taken together, are logically nonsensical, so some remedy is required. ...Also, you can go the lorentzian relativity route and say that moving objects actually do get smaller because they are a doppler shifted wave in a (completely undetectable and otherwise irrelevant) aether.... Sorry, I missed this post earlier. I'm not that familiar with the Lorentz aether, but from what I recall the speed of light is not constant.
owl Posted August 31, 2011 Author Posted August 31, 2011 (edited) Swansont: No, I have assumed that what we measure is reality, which is the basis of science. What about what we don't measure. Is that reality too, or does reality require our measurements? Cap 'n R: So how can you conclude that there are vasts amount of evidence to support the claim that Earth will be spherical when we fly past at high speeds? Nobody's ever done it before. Earth will probably not appear spherical if ever visitors at extremely high speed observe it on the near 'c' fly by. But they will probably be intelligent enough scientists to mathematically "transform" the very oblate spheroid they see (visibly contracted as it might appear) into the nearly spherical planet that has a shape of its own, not dependent on how it is observed. And the fact that no one has ever done it before leaves the version of the very oblate earth in the realm of unverified theory (not to mention physically impossible, in a universe of real, nearly spherical planets),... while all the science done on earth makes it out to be nearly spherical. How long will you continue this farce? (a rhetorical question, of course... in a humorous spirit... no answer required.) Edited August 31, 2011 by owl -1
moth Posted August 31, 2011 Posted August 31, 2011 I have defined time as event duration of physical processes. Not an entity. Nothing to expand (the meaning of dilation.) Do you agree? I don't know if space and time are entities. Since there are working mathematical models of space and time I have to wonder if it's possible to model nothing, but I'm not sure if not nothing is something. Do you agree that recessional velocities increase with distance or are those observations that show they do in error?
owl Posted August 31, 2011 Author Posted August 31, 2011 Me: I have defined time as event duration of physical processes. Not an entity. Nothing to expand (the meaning of dilation.) Do you agree? Moth: I don't know if space and time are entities. Since there are working mathematical models of space and time I have to wonder if it's possible to model nothing, but I'm not sure if not nothing is something. There is a large body of papers from a decade or so of conferences convened by the International Society for the Advanced Study of Spacetime. (See my spacetime ontology thread in "Philosophy.") This society takes nothing for granted about space or time or spacetime. The nature of ontology is to take nothing for granted, even the sacrosanct combo of space and time as a very malleable "fabric" without a referent in the observable world. Moth: I have to wonder if it's possible to model nothing, but I'm not sure if not nothing is something It is not only possible but frequent that theorists come up with very complex models that have no *referents* in the observable world of objects and forces. Many think 'spacetime' is one of them, a "map" in the mathematical/physics mind of scientists but signifying nothing in the world of matter and energy/forces. Gravity does not require "spacetime" to work. But it is a sophisticated model, kind of a scaffolding for the math. My take, anyway. Moth: Do you agree that recessional velocities increase with distance or are those observations that show they do in error? Please elaborate with examples of objects with "recessional velocities increasing with distance." Velocities depend on the forces which propel the objects (and gravitational forces which pull on them), not on distance traveled per se, unless away from a gravitational force, which will allow more velocity from internal propulsion.
swansont Posted August 31, 2011 Posted August 31, 2011 What about what we don't measure. Is that reality too, or does reality require our measurements? There are plenty of things we can't measure that are arguably real, but since we are talking about a specific case where there is a measurement, I see no need to change the discussion. Earth will probably not appear spherical if ever visitors at extremely high speed observe it on the near 'c' fly by. But they will probably be intelligent enough scientists to mathematically "transform" the very oblate spheroid they see (visibly contracted as it might appear) into the nearly spherical planet that has a shape of its own, not dependent on how it is observed. Now all you have to do is come up with an objective way to tell who is moving and who is stationary to see which one is the "real" measurement. And what of the earth's observers seeing the rocketship? It, too, will be length contracted. Is what they observe not real?
Iggy Posted August 31, 2011 Posted August 31, 2011 Earth will probably not appear spherical if ever visitors at extremely high speed observe it on the near 'c' fly by. But they will probably be intelligent enough scientists to mathematically "transform" the very oblate spheroid they see (visibly contracted as it might appear) into the nearly spherical planet that has a shape of its own, not dependent on how it is observed. BTW, it is a misconception that clocks don't really dilate and distances don't really shrink, it just appears that way as a visual distortion. It is possible to avoid this misunderstanding by learning about the Doppler effect and aberration and understanding how they are separate from (and additional factors to) time dilation and length contraction. If one is averted to physics they can avoid the misunderstanding by remembering that visual distortions do not affect the object being distorted. If you send a clock off at high speed and have it return to you it doesn't just appear to have ticked slow on the journey. After it returns it actually shows less duration. A spaceship traveling a distance between two objects and moving quite fast (relative to them) will likewise show a shorter distance between the objects on its odometer than a slow spaceship traveling the same distance will show. The distance doesn't just appear shorter, it is shorter. When the trip is done and the clocks and odometers are held side by side they do not agree -- a physically real effect that visual distortions don't produce.
moth Posted August 31, 2011 Posted August 31, 2011 Please elaborate with examples of objects with "recessional velocities increasing with distance." Velocities depend on the forces which propel the objects (and gravitational forces which pull on them), not on distance traveled per se, unless away from a gravitational force, which will allow more velocity from internal propulsion. I was thinking about the supernova and Cepheid variable data that is used to support the idea of Hubble expansion. You've said you don't believe the expansion of space is possible but didn't specify if you also disputed the evidence for the motions of distant galaxies moving away at velocities which increase with distance.
owl Posted August 31, 2011 Author Posted August 31, 2011 Swansont: No, I have assumed that what we measure is reality, which is the basis of science. Me: What about what we don't measure. Is that reality too, or does reality require our measurements? Swansont: There are plenty of things we can't measure that are arguably real, but since we are talking about a specific case where there is a measurement, I see no need to change the discussion. My philosophical argument in this thread is that the world/cosmos is real and has intrinsic properties independent of observation and measurement. The idealist argument is that nothing is real but our observations, including scientific measurement. You say, "what we measure is reality," which makes you an idealist. To verify that I asked, " does reality require our measurements?" You say that things we can't measure are "arguably real." What, 'maybe so; maybe not'? This is a hedge. Does reality require that it is measured or not? If not, then you grant that earth has a shape independent of how it is observed/measured. You can not have it both ways, logically speaking. Now all you have to do is come up with an objective way to tell who is moving and who is stationary to see which one is the "real" measurement. And what of the earth's observers seeing the rocketship? It, too, will be length contracted. Is what they observe not real? If objects have intrinsic shape which does not drastically change with frames of reference from which they are observed (my argument), then all science has to do is eliminate variables of observation which introduce error or unknowns like, "is length contraction real in the objective, observable world of planets and rockets?"... which is not verified. As I've illustrated with examples (like the microbe under a microscope vs flying through the lab at near 'C'), I argue that at rest (not moving) relative to what is observed/measured will always yield the most accurate measurement or description. Moth: I was thinking about the supernova and Cepheid variable data that is used to support the idea of Hubble expansion. You've said you don't believe the expansion of space is possible but didn't specify if you also disputed the evidence for the motions of distant galaxies moving away at velocities which increase with distance. Off topic, but for the ontology of "what is space?" If space is empty volume but for the things which occupy space, then more space between objects is always due to their moving away from each other, not "space" (empty volume) expanding. I do not dispute that galaxies are moving away from each other, or that their rate of doing so is increasing. An expanding cosmos (with increasing rate of expansion) refers to the stuff in space, not 'space itself' if "it" is just the volume in which the stuff exists.
swansont Posted August 31, 2011 Posted August 31, 2011 My philosophical argument in this thread is that the world/cosmos is real and has intrinsic properties independent of observation and measurement. The idealist argument is that nothing is real but our observations, including scientific measurement. You say, "what we measure is reality," which makes you an idealist. To verify that I asked, " does reality require our measurements?" You say that things we can't measure are "arguably real." What, 'maybe so; maybe not'? This is a hedge. Does reality require that it is measured or not? If not, then you grant that earth has a shape independent of how it is observed/measured. You can not have it both ways, logically speaking. Not true, when the logic is flawed. You present a false dichotomy. If there are things that are real yet cannot be measured, they fall into neither category. Exactly what you'd expect of a false dichotomy. If objects have intrinsic shape which does not drastically change with frames of reference from which they are observed (my argument), then all science has to do is eliminate variables of observation which introduce error or unknowns like, "is length contraction real in the objective, observable world of planets and rockets?"... which is not verified. As I've illustrated with examples (like the microbe under a microscope vs flying through the lab at near 'C'), I argue that at rest (not moving) relative to what is observed/measured will always yield the most accurate measurement or description. Why does your philosophy only work at the scale at rockets and planets? Are atomic nuclei not real, according to your philosophy? Arguing about accuracy of measurement is a red herring. The theory of relativity does not reflect nor depend on inaccurate measurements. The theory is quite independent of such errors — they only limit the extent you can confirm (or exclude) a theory.
moth Posted August 31, 2011 Posted August 31, 2011 Sorry if I seem off-topic here, but you've implied that length can not be frame dependent because space is empty volume - nothing to expand or contract. If expanding space is not causing recessional velocity to increase with distance then some force must be acting on those bodies to accelerate them. If expanding space IS causing the universe to change this way then space can be mutable even if not tangible. Changes in space itself are a simple way to explain both recessional velocities and (with time dilation) a constant speed of light. You seem to be abandoning Occam's razor in favor of a desire to make space fit some pre-conceived ideas about it.
owl Posted August 31, 2011 Author Posted August 31, 2011 (edited) Swansont: Not true, when the logic is flawed. You present a false dichotomy. If there are things that are real yet cannot be measured, they fall into neither category. Exactly what you'd expect of a false dichotomy. You may be a brilliant physicist, but you would have flunked my class on Logic and the Scientific Method. If you see a flaw in the logic I presented in my last post, by all means specify the flaw. There is no "false dichotomy" in the "either/or" ( or "if/then") conditional (not a syllogism) logic I argued. Either objects exist and have properties independent of observation and measurement Or they don't. If the latter, then then their existence and properties depend on how they are observed and measured. Obviously there are "things" beyond science's ability to observe and measure them. (Or would you also disagree with this?) This means that the cosmos with all its properties exists and has intrinsic properties whether we observe and measure them or not. (Repetitive, but it seems necessary.) Do you agree with this or not? If not, then you are an idealist. Moth: Sorry if I seem off-topic here, but you've implied that length can not be frame dependent because space is empty volume - nothing to expand or contract.If expanding space is not causing recessional velocity to increase with distance then some force must be acting on those bodies to accelerate them. If expanding space IS causing the universe to change this way then space can be mutable even if not tangible. No problem with the "off topic" issue. The ontology of space, time, spacetime, and what is real, independent of observation, measurement and conceptual models is all interconnected. Ontology investigates what exists and the nature/properties thereof. If space is some kind of expandable/contractable medium, then the "burden of proof" is on those who make that claim to show empirical evidence for it... which can not be explained by observation of moving objects without such "entities" as "expanding space", "curved spacetime", "dilating time" (not just clocks slowing down), etc. The force which is making the objects in the cosmos move away from each other at an accelerating rate is still a mystery to everyone. I thought it might be masses beyond our cosmic event horizon pulling the visible cosmos outward, but the "shell theorem" of gravity presented by Spyman in another of my threads seemed to invalidate that cosmology. (But multiple "Bangs" at different epicenters beyond our visible cosmos would make the shell theorem irrelevant....Way beyond the topic here.) Please explain what you mean by "mutable even if not tangible" here: "If expanding space IS causing the universe to change this way then space can be mutable even if not tangible." Ontologically, if 'something' (space) is said to be expanding, then it must be some kind of entity besides empty volume, which is a lack of entities or the vacuum between entities. Same for "time." Clocks obviously "tick" more slowly at high velocity and higher gravitational fields, which complicates the math for GPS clock synchronicity vis-a-vis surface travel positioning. But "time dialtion" grants "time" the ontological equivalent of status as an entity. So that requires that everything in every different velocity or gravitational situation has a specific time 'environment' around it as it moves... which is clearly (to me) absurd. (What is time but event duration for physical processes?) Edited August 31, 2011 by owl -2
moth Posted September 1, 2011 Posted September 1, 2011 Please explain what you mean by "mutable even if not tangible" here: "If expanding space IS causing the universe to change this way then space can be mutable even if not tangible." I mean although we have no way of perceiving empty space directly (not tangible), space has properties like distance that can change (mutable). That is assuming Hubble expansion is correct of course. If some unknown force is accelerating distant galaxies its effects seem to resemble uniform expansion remarkably well. Recently, I saw an article about a "time lens" being used to mask events from detection by a laser beam. As I was trying to find out more about this "time lens" I found a paper suggesting such a device could be used to increase the apparent duration of an event making events too fast to be observed last long enough to see what was happening (at least that's what the abstract seem to say - I couldn't download the actual paper). If it is possible to magnify time that would seem to make it somewhat space-like. the links to the articles are here if you are interested.
md65536 Posted September 1, 2011 Posted September 1, 2011 (edited) You may be a brilliant physicist, but you would have flunked my class on Logic and the Scientific Method. If you see a flaw in the logic I presented in my last post, by all means specify the flaw. There is no "false dichotomy" in the "either/or" ( or "if/then") conditional (not a syllogism) logic I argued. Either objects exist and have properties independent of observation and measurement Or they don't. If the latter, then then their existence and properties depend on how they are observed and measured. Oooof. You would have been fired from my university. "(A and B) or Not (A and B)" is a tautology and is true. "Not (A and B) implies not B" is not true in general. Let A be "Objects exist". Let B be "Objects have properties independent of observation and measurement". "If the latter" ("they don't") is equivalent to "Not A and B", which is equivalent to "Not A or Not B". Not B would mean "Objects don't have properties independent of observation and measurement." Not A would mean "Objects don't exist", in which case their existence doesn't depend on how they are observed. In this case, your argument is invalid. Now maybe this is all pedantic and what you meant was what you'd get if you cleaned up the logic and resolved ambiguities with what I think you meant: "Either (all objects that exist have one or more properties independent of observation and measurement), or not. Assume: not (all objects that exist have one or more properties independent of observation and measurement). Then there exists an object that doesn't have any properties independent of observation and measurement. Then there exists an object that has no properties or has at least one property that is dependent on observation OR measurement." If this isn't the correct interpretation it can be corrected, but it's not possible to deduce your original conclusion as it is. If you used proper logic, you'd see the logical problem with your argument. You're basically trying to say that if one property of any object is dependent on observation, then all properties of all objects are. You are leaving out SO MANY possibilities, which cannot fit into your false dichotomy. Obviously there are "things" beyond science's ability to observe and measure them. (Or would you also disagree with this?) This means that the cosmos with all its properties exists and has intrinsic properties whether we observe and measure them or not. (Repetitive, but it seems necessary.) Do you agree with this or not? If not, then you are an idealist. Here for example, you jump to "all its properties" with no justification. I disagree with your statement. But I am not an idealist. I agree that there are things beyond science's ability to observe and measure. This includes for example things that we can infer the existence of, but aren't practically able to observe, or aren't able to measure (if you want to make any distinction). So I don't even have to limit myself to questioning the existence of things that are not even theoretically possible to observe. Personally I believe that there are objects that have some properties that are invariant and thus don't matter how they are observed, AND other properties that depend on how they are observed. This means that I believe it is possible that these objects have a real existence outside of my mind. Therefore I am not a subjective idealist, by definition. I do not fit into your false dichotomy. Hey out of curiosity, why is it that you no longer teach Logic and the Scientific Method? I'm impressed with your immovable resolve to not give in on any aspects of your arguments. It would be a super useful attribute for a student to have, to reach a point where there is nothing new to learn that makes any difference. Please stop using it to insult others. Edited September 1, 2011 by md65536 1
owl Posted September 1, 2011 Author Posted September 1, 2011 Md65536: Oooof. You would have been fired from my university. A personal attack immediately takes points off in a logic debate. My one semester class was full and cited for merit by the dean of the Philosophy Dept. Your insult sets the sophomoric, personal attack tone of your argument. Hey out of curiosity, why is it that you no longer teach Logic and the Scientific Method? As for the above snide insinuation, at age 66 I am retired from my private practice in psychology, and my brief tenure as a teacher of that class was a one time thing... a one semester special studies elective course with focus on the place of logic in science. (I taught other "special studies" courses in psychology.) I found your analysis pedantic, tedious even, and having missed the point of my premise: Either the world/cosmos exists in and of itself, as it is, with intrinsic properties independent of observation, or it's existence (and properties) are dependent on how they are observed. The former is realism and the latter is idealism. Maybe that is too simple for you to understand. Not my problem. I'm impressed with your immovable resolve to not give in on any aspects of your arguments. It would be a super useful attribute for a student to have, to reach a point where there is nothing new to learn that makes any difference. Please stop using it to insult others. More personally insulting insinuation... that I am closed minded. My colleagues know me better than that. "Immovable resolve" is quite a judgmental characterization of me. I have been an amateur scientist all my life (since I could think for myself) and I say it as I see it, with the benefit of a hereditary high genius intelligence, as measured by both the SBIS and the WAIS, in case you missed that post.
md65536 Posted September 1, 2011 Posted September 1, 2011 I found your analysis pedantic, tedious even, and having missed the point of my premise: [...] "Immovable resolve" is quite a judgmental characterization of me. I have been an amateur scientist all my life (since I could think for myself) and I say it as I see it, with the benefit of a hereditary high genius intelligence, as measured by both the SBIS and the WAIS, in case you missed that post. Well done owl! I'm genuinely impressed. This is how I feel right now: I gave it my best shot and you sailed through with ease, unable to be confined by my oppressive need for "right thinking" (as I judge it) in others. I keep getting pulled into your threads because most of the others I'm interested in seem to die (sometimes my fault), while you manage to keep a lively debate going. I was worried I might kill this one, but you quickly proved me wrong. So I'll bow out now, and instead silently cheer you on from now on. I disagree with what you say, but I'll defend to the death of the thread your persistence in saying it.
tar Posted September 1, 2011 Posted September 1, 2011 Iggy, Sorry for the long delay in response. Irene left us without power for 48hrs. and we just got internet back this afternoon. I had difficulties with the red line, because the trail end of it followed the moving planet. The trail end of it should have stayed at the starting point. But you tell me it was to show the distance between the moving planet and the photon. This is fine, except how does the scientist on the moving planet determine how far away from the ship the photon has gotten? We need the third "god's eye view" to make this determination. The moving planet's scientist cannot "see" the photon get to the other planet. I return to my simutaneity question. If the moving scientist knows the distance at the start is 1 light year, the photon will get there in a year and the moving planet,(I forget its speed, say .9C) will get there in 1.11... years. Whose perspective, or whose "now" is violated by this reality? Is the objective reality that relativity describes based on the now of the moving planet, the now of the stationary planet, or the now of a "God's eye" view that can see all events happening at once? Regards, TAR2
Iggy Posted September 1, 2011 Posted September 1, 2011 Iggy, Sorry for the long delay in response. Irene left us without power for 48hrs. and we just got internet back this afternoon. No trouble, and sorry to hear. My sister, out east, lost power for about 24 hours as well. It wouldn't have been bad, but she has an autistic child that had a hard time coping. I had difficulties with the red line, because the trail end of it followed the moving planet. The trail end of it should have stayed at the starting point. But you tell me it was to show the distance between the moving planet and the photon. Yes, the blue planet will figure that the speed of the photon is its distance (the length of the red line) divided by time. This is fine, except how does the scientist on the moving planet determine how far away from the ship the photon has gotten? There is no ship. The photon goes from one planet to the other. The two planets are moving relative to one another. The green planet considers itself at rest. This is its frame of reference: The blue planet considers itself at rest. Its frame: The same thing is happening in both frames. The only difference between the two is velocity. Each planet is at rest in its own frame. We need the third "god's eye view" to make this determination. I'm not sure that would help. The moving planet's scientist cannot "see" the photon get to the other planet. I wouldn't think of it as a "moving" planet and a planet "at rest", because there is no real world way to make that determination. Whatever physics we use should be able to treat either planet at rest while the other one moves. As far as not seeing the photon reach the other planet, that is fine. We aren't calculating when it is seen, we're calculating when it happens. I return to my simutaneity question. If the moving scientist knows the distance at the start is 1 light year, the photon will get there in a year and the moving planet,(I forget its speed, say .9C) will get there in 1.11... years. If the planet moves halfway in 1 year then that would be half a light-year in one year, or .5c. Whose perspective, or whose "now" is violated by this reality? Is the objective reality that relativity describes based on the now of the moving planet, the now of the stationary planet, or the now of a "God's eye" view that can see all events happening at once? The point is that the blue planet must figure the speed of light differently than the green planet. If the green planet calculates 1c, as in this case, and the blue planet has a relative velocity then it will calculate the speed differently... 0.5c in this case. It is a matter of logic, if both planets agree on the distance that the photon moves and the time it takes to move then the velocity of the photon is different in the two frames of reference... it isn't constant. The red triangle moves faster (just by watching it you can see) in the first image above. It moves 1c in the first and .5c in the second. The speed of light isn't constant in classical mechanics. If the speed of light is constant in the real world then some remedy is needed (eg special relativity). Does reality require that it is measured or not? If not, then you grant that earth has a shape independent of how it is observed/measured. You can not have it both ways, logically speaking. You can avoid elementary mistakes in logic by changing the subject and/or predicate of your statement and seeing if the logic holds. For example, you say: Does reality require that it is measured or not? If not, then you grant that earth has a shape independent of how it is observed/measured. You can not have it both ways, logically speaking. change the property "shape" for the property "velocity": Does reality require that it is measured or not? If not, then you grant that earth has a velocity independent of how it is observed/measured. You can not have it both ways, logically speaking. You have already rejected the idea that earth has "a velocity" so you clearly have a false dichotomy. If you try this in future posts you can avoid a great number of logical fallacies. 1
owl Posted September 1, 2011 Author Posted September 1, 2011 The topic of this thread seems to have run its course without resolution. I will make another attempt at the latter by reviewing selective quotes from the argument between myself and Swansont from page 12. Bold will signify unanswered questions or challenges. From post 221: I repeat that seeing it as different shapes from different points of view (frames of reference) does not make it different, and that would be an idealist's assertion. Since all agree (I thought) that it doesn't "morph" (change shapes),it is a specific, unchanging shape. Is it nearly spherical, as per at rest frame, or is it extremely oblate... in the real world? Pick one, unless its all about how you look at it (idealism) and it has no objective, intrinsic shape. Which version has actual evidence to support it? Swansont: No, we don't agree that the earth doesn't drastically change shape."Is it spherical or is it oblate?" is functionally equivalent to "Have you stopped beating your wife?" — it's a loaded question that cannot be answered yes or no. Realism asserts that objects in the real world have intrinsic shapes independent of how they are observed. So the question, "What shape is earth?" is nothing like the assumption that one is beating his wife, leading to the question, "Have you stopped?" Me: Seeing things as shaped differently from different points of view does not mean that they actually are shaped differently, depending on how you see them. From post 230: Me; Realism realizes that the universe has a reality independent of observational frames of reference. Swansont: No, realism asserts this. It is not borne out by experiment. So, the universe does not exist as a reality independent of observational frames of reference? Pure idealism. Swansont on evidence for large scale length contraction: Muons must decay before reaching the earth is this is true. Why does the science tell us otherwise? As argued more than once already: Muons incoming through the atmosphere “live longer” than muons in a particle accelerator, so they travel further than expected. The atmosphere does not get way thinner around the former, as length contraction would have it. Swansont: In forming the argument you have presupposed that length is invariant, and it is not. Me: In saying that it is not, you have presupposed that reality is dependent on how it is observed, which is the argument for idealism.Realism does indeed suppose that things are as they are intrinsically, in the real world, independent of how they are observed. Swansont: No, I have assumed that what we measure is reality, which is the basis of science. Me, from 233: What about what we don't measure. Is that reality too, or does reality require our measurements? Swansont: There are plenty of things we can't measure that are arguably real, but since we are talking about a specific case where there is a measurement, I see no need to change the discussion. Me: My philosophical argument in this thread is that the world/cosmos is real and has intrinsic properties independent of observation and measurement. The idealist argument is that nothing is real but our observations, including scientific measurement. You say, "what we measure is reality," which makes you an idealist. To verify that I asked, " does reality require our measurements?" You say that things we can't measure are "arguably real." What, 'maybe so; maybe not'? This is a hedge. Does reality require that it is measured or not? If not, then you grant that earth has a shape independent of how it is observed/measured. You can not have it both ways, logically speaking. Swansont: Not true, when the logic is flawed. You present a false dichotomy. If there are things that are real yet cannot be measured, they fall into neither category. Exactly what you'd expect of a false dichotomy. You never replied to my challenge to show how my logic was flawed. Swansont: Now all you have to do is come up with an objective way to tell who is moving and who is stationary to see which one is the "real" measurement.And what of the earth's observers seeing the rocketship? It, too, will be length contracted. Is what they observe not real? Me: If objects have intrinsic shape which does not drastically change with frames of reference from which they are observed (my argument), then all science has to do is eliminate variables of observation which introduce error or unknowns like, "Is length contraction real in the objective, observable world of planets and rockets?"... which is not verified.As I've illustrated with examples (like the microbe under a microscope vs flying through the lab at near 'C'), I argue that at rest (not moving) relative to what is observed/measured will always yield the most accurate measurement or description. Swansont: Why does your philosophy only work at the scale at rockets and planets? Are atomic nuclei not real, according to your philosophy? Arguing about accuracy of measurement is a red herring. The theory of relativity does not reflect nor depend on inaccurate measurements. The theory is quite independent of such errors — they only limit the extent you can confirm (or exclude) a theory. Again my argument is that there is no evidence for length contraction beyond subatomic scale. I am not an atomic physicist, so I do not know how they got length contraction from measuring the distance between the “end points” of subatomic particles (yes, they are real) in an accelerator. No red herring. If earth stays the same shape (as all but you agree,... no “morphing”, as Cap ‘n R agreed), it can not be both nearly spherical and very oblate. It must be one or the other. If it were to be measured as having a diameter of 1000 miles through either the equator or the poles... (length contracted to 1/8th as per Cap 'n R's scenario) rather than the well known and validated 8000 or so miles, the former measurement would be in error. Even after so much repetition, as above, the basic challenge has not been addressed. This post will be my last attempt at resolution if the realism vs idealism issue is still not answered.
swansont Posted September 1, 2011 Posted September 1, 2011 Swansont: You may be a brilliant physicist, but you would have flunked my class on Logic and the Scientific Method. Yeah, well I've given it some thought and I find that I'm OK with this. You have flunked the class on relativity. If you see a flaw in the logic I presented in my last post, by all means specify the flaw. There is no "false dichotomy" in the "either/or" ( or "if/then") conditional (not a syllogism) logic I argued. Either objects exist and have properties independent of observation and measurement Or they don't. If the latter, then then their existence and properties depend on how they are observed and measured. Obviously there are "things" beyond science's ability to observe and measure them. (Or would you also disagree with this?) This means that the cosmos with all its properties exists and has intrinsic properties whether we observe and measure them or not. (Repetitive, but it seems necessary.) Do you agree with this or not? If not, then you are an idealist. Your error (or at least one of them) is that "there are properties independent of observation and measurement" is not the same as "length is a property that is independent of observation and measurement." Several of us have pointed out that there are invariant properties. It's just that length is not one of them. Objects have properties independent of observation and measurement Length is a property Therefore length is independent of observation and measurement Surely you can identify this as faulty logic, right? A personal attack immediately takes points off in a logic debate. My one semester class was full and cited for merit by the dean of the Philosophy Dept. Your insult sets the sophomoric, personal attack tone of your argument. So it's only OK when you do it ?!? You never replied to my challenge to show how my logic was flawed. It's less than 24 hours from your post, and since you still haven't figured out how to properly use the quote tags (that point to the user and post), I didn't get a notification that there was a pending response. 2
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