owl Posted June 9, 2011 Author Posted June 9, 2011 md65536 Einstein's saying that space and time don't exist on their own.If something exists on its own, when considered as independent of other things, this implies that it is an entity (by the very definition of entity), agreed? But time is not an entity, agreed? Therefore, time does not exist on its own. Similarly space is not an entity, agreed? Therefore, space does not exist on its own. If you agree with all these things, where's the problem with Einstein's quote? Okay so I thought you were saying that time must be something more than what SR/GR says, but are you instead saying it is something less? I do agree that neither time nor space are entities. As for space-as-emptiness, my “problem” with the quote is that emptiness does not "disappear" when matter disappears as entities existing in space. The lack of matter in space is emptiness. If time is simply event duration as things move*, then, of course, if there are no “things” (matter) left to move... time becomes meaningless. (* faster or slower in different environments = "time dilation.") It has already been pointed out that these environmental factors can be either controlled or compensated for, so there's no point in bringing them up again and again. After you have stripped out those factors you still have time dilation effects, and these effects are independent of the kind of clock you have. As Cap'n R has pointed out, we can measure the dilation without answering the ontological question. We can measure the different rates at which clocks “tick” in different environments, and call these differences “time dilation” (implying that time is an entity.) But the point of an ontological analysis of time is that it is quite different to assert that some-thing-time “dilates” than to simply acknowledge the differences in “ticking” rates in different environments. As for “stripping out those factors,” if environments are “identical” after experimental controls are perfected, will not those rates will be identical (assuming, of course, accurately calibrated and functioning clocks?) I believe what md65536 was trying to get at was this: We observe time dilation (or something which appears to be time dilation) through empirical observation. We can make predictions about its behavior through mathematics and our current theories of physics. If we propose an answer to the question, "What dilates?", is there any way to test that answer through empirical observation? Clearly at the moment we can observe dilation but do not know what is dilating. If I propose three different answers to that question, is there any way to discern between them experimentally, given that the clocks will show time dilation in exactly the same way no matter which of the three answers is correct? I think my comments immediately above address your reply. If relativity were to quit insisting that time is an entity which "dilates," and just call it time-keeping variability in different environments, this would satisfy the ontological objection to making time an entity.
DrRocket Posted June 9, 2011 Posted June 9, 2011 This stuff is extremely intuitive. All that needs to occur in order to correctly understand the relationship between the rate at which atomic clocks tick and time is to correctly define what a second is. The present definition is: the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. The correct definition is: the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom [at sea level]. wrong
mpc866 Posted June 9, 2011 Posted June 9, 2011 (edited) wrong Are you suggesting if you exited the space station in what you are wearing right now you would not be affected by the physical state of the space in which you existed? The fact that there is no oxygen and the pressure is so low would not affect you physically at all? Of course not. Why is it only an atomic clock is the only thing which exists that we know of which is not affected by the physical state of the space in which it exists? Because it is. The rate at which an atomic clock ticks is determined by the physical state of the space in which it exists. Just like all other physical processes. Edited June 9, 2011 by mpc866
Cap'n Refsmmat Posted June 9, 2011 Posted June 9, 2011 I think my comments immediately above address your reply.If relativity were to quit insisting that time is an entity which "dilates," and just call it time-keeping variability in different environments, this would satisfy the ontological objection to making time an entity. My point is that if time is an entity independent of our timekeeping, it is unknowable through experiment, as we can only measure timekeeping, not time. Hence it is meaningless to talk about time as something other than what clocks measure.
mpc866 Posted June 10, 2011 Posted June 10, 2011 (edited) My point is that if time is an entity independent of our timekeeping, it is unknowable through experiment, as we can only measure timekeeping, not time. Hence it is meaningless to talk about time as something other than what clocks measure. If you own a battery operated clock and it ticks slower has time changed? Of course not. if you heat up an atomic clock and cause it to tick faster has time changed? Of course not. Why are you unable to understand the rate at which an atomic clock ticks is determined by the physical state of the space in which it exists? Edited June 10, 2011 by mpc866
Cap'n Refsmmat Posted June 10, 2011 Posted June 10, 2011 If you own a battery operated clock and it ticks slower has time changed? Of course not. if you heat up an atomic clock and cause it to tick faster has time changed? Of course not. Why are you unable to understand the rate at which an atomic clock ticks is determined by the physical state of the space in which it exists? Take two atomic clocks which exist in inertial reference frames in relative motion. Each is traveling at a constant velocity in a region of space with no gravitational fields. Each is kept in otherwise identical conditions, apart from the relative motion. The clocks nevertheless will disagree with each other. What state of physical space causes this? There is no way inside each clock to discern between constant velocity motion and being at rest, as you know, so there is no physical state to account for the dilation. 1
DrRocket Posted June 10, 2011 Posted June 10, 2011 Are you suggesting if you exited the space station in what you are wearing right now you would not be affected by the physical state of the space in which you existed? The fact that there is no oxygen and the pressure is so low would not affect you physically at all? Of course not. Why is it only an atomic clock is the only thing which exists that we know of which is not affected by the physical state of the space in which it exists? Because it is. The rate at which an atomic clock ticks is determined by the physical state of the space in which it exists. Just like all other physical processes. An atomic clock registers the proper time of its world line. You need to learn some physics and stop making positive assertions that you don't understand. Making up physics as you go along is just silly. "The state of the space in which it exists" is meaningless unless you can define your terms in detail, and specify precisely and quantitatively what constitutes your state space.
mpc866 Posted June 10, 2011 Posted June 10, 2011 (edited) Take two atomic clocks which exist in inertial reference frames in relative motion. Each is traveling at a constant velocity in a region of space with no gravitational fields. Each is kept in otherwise identical conditions, apart from the relative motion. The clocks nevertheless will disagree with each other. What state of physical space causes this? There is no way inside each clock to discern between constant velocity motion and being at rest, as you know, so there is no physical state to account for the dilation. The rate at which an atomic clock ticks is determined by the state of the aether in which it exists. Atomic clocks in regions of space with no gravitational fields move with respect to the state of the aether. The faster an atomic clock moves with respect to the state of the aether the more aether the clock displaces the more the displaced aether exerts force towards and throughout the atomic clock the slower the clock ticks. What is gravitational potential? It is the force exerted by the displaced aether towards the matter doing the displacing. Moving with respect to the state of the aether is no different. 'Ether and the Theory of Relativity by Albert Einstein' http://www-groups.dcs.st-and.ac.uk/~history/Extras/Einstein_ether.html "the state of the [ether] is at every place determined by connections with the matter and the state of the ether in neighbouring places, ... disregarding the causes which condition its state." The state of the aether at every place determined by its connections with the matter and the state of the ether in neighboring places is the state of displacement of the aether. Now, before I get banned for mentioning the aether, I was answering a specific question as to what is the physical state of the space which causes atomic clocks to tick at different rates which I have answered.The physical state of the space is the state of displacement of the aether. If you are not allowed to answer specific questions then this forum should not exist. Your turn to answer a question. If you apply enough heat to an atomic clock it ticks faster. Has time changed? What is the difference between apply heat to an atomic clock which causes it to tick faster and a change in gravitational potential which causes it to tick faster where one is simply a change in the physical state of the atomic clock and the other causes time to change? An atomic clock registers the proper time of its world line. You need to learn some physics and stop making positive assertions that you don't understand. Making up physics as you go along is just silly. "The state of the space in which it exists" is meaningless unless you can define your terms in detail, and specify precisely and quantitatively what constitutes your state space. You need to move away from the math and understand the physics of nature to understand what I am stating. Hiding your head in the math in order to not understand what occurs physically in nature is just silly. The physical state of the space in which an atomic clock exists is the state of displacement of the aether. 'Ether and the Theory of Relativity by Albert Einstein' http://www-groups.dc...tein_ether.html "the state of the [ether] is at every place determined by connections with the matter and the state of the ether in neighbouring places, ... disregarding the causes which condition its state." The state of the aether at every place determined by its connections with the matter and the state of the aether in neighboring places is the state of displacement of the aether. It is the state of displacement of the aether which exerts force towards and throughout an atomic clock which determines the rate at which the clock ticks. Edited June 10, 2011 by mpc866 -2
md65536 Posted June 10, 2011 Posted June 10, 2011 I do agree that neither time nor space are entities. As for space-as-emptiness, my "problem" with the quote is that emptiness does not "disappear" when matter disappears as entities existing in space. The lack of matter in space is emptiness. Suppose you have some space and you take everything but the space away (if such a thing is possible). Does the space still exist on its own, independent of all other things? If yes, then it is an entity. If no, then Einstein's quote holds (sorta... the quote speaks of space without "matter" while I'm speaking about space without "everything"). If it's impossible to take everything out of space, then space can't exist on its own. So the quote holds. We can measure the different rates at which clocks "tick" in different environments, and call these differences "time dilation" (implying that time is an entity.) No, it does not imply that at all. What if we didn't call it "time dilation", but instead called it "time differences"? Does that make time an entity? What if we just called it "differences in the measurements of the rates at which clocks tick in different environments"? Does that make time an entity? Does giving something a name (like "time dilation") give it a physical presence? I really think you're making a huge imaginative and misunderstanding-filled jump from "statements about time" to "time is an entity". I think that SR/GR is closer than you think, philosophically, to your own beliefs about time. I think that because SR makes claims about time (or the measurements of clocks) that you don't understand, you are assuming that it's claiming that time is a "thing", when really it is not. Time dilation does not imply that time is an entity.
swansont Posted June 10, 2011 Posted June 10, 2011 If you own a battery operated clock and it ticks slower has time changed? Of course not. if you heat up an atomic clock and cause it to tick faster has time changed? Of course not. Why are you unable to understand the rate at which an atomic clock ticks is determined by the physical state of the space in which it exists? A failure of basic logic Premise: If A, then B B, therefore A is the Fallacy of Affirming the Consequent ——— All mechanical changes in clocks change their indicated time A change in indicated time does NOT logically imply a mechanical change
Spyman Posted June 10, 2011 Posted June 10, 2011 I take it you didn't notice this is my third username tonight? I take it you are a reincarnation of mpc755 and mpc7555 then? 9. Registering more than one account to yourself is not permitted without administrative approval. "Sockpuppet" accounts (those registered with the intent of using them to spread the original member's ideas, or for other malicious purposes) will be banned on sight, as well as those registered to evade a ban. ScienceForums.Net Forum Rules
owl Posted June 13, 2011 Author Posted June 13, 2011 Having been out of net service a few days, its review and catch-up time for me. A bit scattered... sorry, but still 'doggedly' on track for ontology of time. Cap ‘n R: Clearly at the moment we can observe dilation but have no way of telling what is dilating, really. Is not “what we can observe,”( calling it “dilation”) here the same as “clocks ticking at different rates in different environments?” Why assume time is “something dilating” at all? Why not just stick to what we observe, which is certainly not some entity, time? swansont: As Cap'n R has pointed out, we can measure the dilation without answering the ontological question. Why talk of time as a malleable entity if we have no idea what “it” is, if anything (not)? If it is just event duration of physical processes, we can just say that these processes slow down without reifying time. from my post 63, (again... still): Ontology asks, What slows down in so called “time dilation” situations besides those physical processes? My argument is that the latter is the reality, while time remains an artifact of measurement, the concept of duration which the phrase “time dilation” erroneously reifies (making time into an entity in and of itself.) md65536: Be careful with your terminology. Time is the measurement. So the whole cosmos and all of its moving parts, being physical processes which “take time” to happen, have no “duration” (elapsed time) unless and until each event is “measured?” md:... “a measurement of what?...” is exactly what ontology asks about time. I’m still hoping for an answer to this from my post 76 (Quite repetitive, I realize but still the basic unanswered ontology): But the point of an ontological analysis of time is that it is quite different to assert that some-thing-time “dilates” than to simply acknowledge the differences in “ticking” rates in different environments. As for “stripping out those factors,” if environments are “identical” after experimental controls are perfected, will not those rates will be identical (assuming, of course, accurately calibrated and functioning clocks?)... and this: If relativity were to quit insisting that time is an entity which "dilates," and just call it time-keeping variability in different environments, this would satisfy the ontological objection to making time an entity. Cap ‘n R: My point is that if time is an entity independent of our timekeeping, it is unknowable through experiment, as we can only measure timekeeping, not time. Hence it is meaningless to talk about time as something other than what clocks measure. Then it is also meaningless to constantly speak of “time dilation” rather than just clock variability. The former reifies it, while the latter just speaks to what we observe. And finally, a repeat of an unanswered footnote. Who will answer the basic ontological challenge to the Einstein quote above about space and time? Paraphrased... If all matter were to disappear, so would space and time. So the emptiness left with matter gone is what?... not empty *space?* Of course, as already acknowledged, with nothing left to move, "time" as physical process duration would be meaningless, even though "it" (time) was no-thing in the first place. -1
Cap'n Refsmmat Posted June 13, 2011 Posted June 13, 2011 As swansont likes to say, time is what clocks measure, so variability in clocks is variability in time. Anything beyond that, such as the material properties of "time" or what it "is," is not directly observable and cannot be known through empirical observations, so it has no place in science. Labeling what we observe "time" does not have to imply it has material properties. It just has a name.
md65536 Posted June 13, 2011 Posted June 13, 2011 (edited) So the whole cosmos and all of its moving parts, being physical processes which "take time" to happen, have no "duration" (elapsed time) unless and until each event is "measured?" Yes, if you consider something being affected by something else to be a measurement. Then it is also meaningless to constantly speak of "time dilation" rather than just clock variability. It is not meaningless. Speak to a scientist about time dilation and they will know exactly the meaning of the words, and the math as well, so the meaning can be precisely used. How is "Clock variability" more meaningful? And finally, a repeat of an unanswered footnote. Who will answer the basic ontological challenge to the Einstein quote above about space and time? Paraphrased... If all matter were to disappear, so would space and time. So the emptiness left with matter gone is what?... not empty *space?* Of course, as already acknowledged, with nothing left to move, "time" as physical process duration would be meaningless, even though "it" (time) was no-thing in the first place. And the same with space. Remove all entities and nothing is all that remains. If something real or physical remains, it is by definition an entity. Edit: I've been thinking... that the best way to do a "ontological analysis of time" is to first understand as much of currently accepted science about time, and see why it is accepted, and see that it is experimentally backed up, and see that it makes sense. It is helpful to let go of any preconceptions about time that you may have. Do not get stuck on unanswerable questions like "but what is time, besides what I can know that it is?" Be aware of what time and related concepts are defined to be, vs. what are experimentally observed consequences, vs. what is an interpretation. Philosophically, you may have some success with the interpretation part of it. If you can find a simpler interpretation, or better yet find a testable consequence of an interpretation, you'll get somewhere. You'll get nowhere assuming that theories backed up by experimental evidence are wrong. For example, one interpretation of time might be that "the future has already happened in some other dimension" or whatever, but that is neither a part of the theory of relativity, nor an observed phenomena -- ontology can easily challenge it and provide alternative interpretations, but it can't challenge observed phenomena without providing a valid explanation for what is observed. Time is what is measured by clocks. By definition, what clocks measure is time. All of these things fit together perfectly like an intricate invisible puzzle. I get the sense that you want to see exactly what time is, and its elusive or ethereal scientific explanation is unsatisfying. The "ontological analysis" that you speak of seems to be nothing more than scattering the pieces of the puzzle, and then being asked for them to be put together in a more visible manner. All the "sciencey" replies to your questions involve the pieces being put back together as they were, as they work. All I see resulting from the ontological analysis is meaningless questions. What are some (or even one) useful results of the analysis? What progress has been made in it? Edited June 13, 2011 by md65536
owl Posted June 13, 2011 Author Posted June 13, 2011 (edited) As swansont likes to say, time is what clocks measure, so variability in clocks is variability in time. Anything beyond that, such as the material properties of "time" or what it "is," is not directly observable and cannot be known through empirical observations, so it has no place in science. Labeling what we observe "time" does not have to imply it has material properties. It just has a name. So defining time with a tautology is no problem for science. Pseudoscience can use the same argument for the existence and properties of "the human aura" as "that which aurameters measure." None of the varieties of "strings" nor the eleven-dimensional membrane made of them in M-theory are "... directly observable and cannot be known through empirical observations, so it has no place in science" either? Wouldn't "clock variability" be a more accurate label for what we observe than the ever elusive "time?" To my: “So the whole cosmos and all of its moving parts, being physical processes which "take time" to happen, have no "duration" (elapsed time) unless and until each event is "measured?"... md65536 replied: Yes, if you consider something being affected by something else to be a measurement. My point was that physical processes even in “galaxies far, far away” "take time to happen” (event duration) naturally, objectively, in the real world regardless of “measurement” by any definition. Cap ‘n R: Hence it is meaningless to talk about time as something other than what clocks measure. Me: Then it is also meaningless to constantly speak of “time dilation” rather than just clock variability. *The former reifies it, while the latter just speaks to what we observe.* Summary: Time and space are not entities but rather just artifacts of measurement. So, how is it that when these two non-entities are combined into “space-time,” “it “ becomes a malleable medium curved by mass/gravity?” Also, how is it that according to "length contraction" in relativity (the distance equivalent of malleable time) the diameter of Earth or Sun-Earth distance will vary with frame of reference from which either is measured? Does anyone actually believe "it's all relative to measurement?" Maybe this question and this thread should now be answered in my “Ontology of Spacetime” thread in the philosophy section. Edited June 13, 2011 by owl
Cap'n Refsmmat Posted June 13, 2011 Posted June 13, 2011 Summary: Time and space are not entities but rather just artifacts of measurement. That is not what I said. I said it is meaningless to speak of the "entities," because they are not observable. They may well exist, but science cannot characterize them, and opacity to experimentation means it does not matter what they "are."
swansont Posted June 13, 2011 Posted June 13, 2011 Is not “what we can observe,”( calling it “dilation”) here the same as “clocks ticking at different rates in different environments?” Why assume time is “something dilating” at all? Why not just stick to what we observe, which is certainly not some entity, time? Why talk of time as a malleable entity if we have no idea what “it” is, if anything (not)? If it is just event duration of physical processes, we can just say that these processes slow down without reifying time. Talking of time as a malleable entity is your strawman. You are the one calling it an entity; AFAICT everyone else has been careful to avoid this description. I think if you look at physics there are a number of things that fall into this category of being reified by some, but are useful nonetheless. Is energy real, or is it a handy bookkeeping trick that is available because the laws of physics do not vary with time? I'd be careful of the argument that takes you down this path. You won't have much physics left at the end of it. There are a large number of quantities/variables that are useful and so we use them. But few insist that they are physical things,even if they don't go out of their way to claim that they aren't. The distinction simply isn't important to some of us, and does not impede us in doing physics. Then it is also meaningless to constantly speak of “time dilation” rather than just clock variability. The former reifies it, while the latter just speaks to what we observe. Speaking of clock variability is too imprecise to be useful. Clocks can vary for reasons other than time dilation.
Iggy Posted June 13, 2011 Posted June 13, 2011 So defining time with a tautology is no problem for science. All definitions are rhetorical tautologies. The word and the definition are one and the same, or at least they should be. You had trouble with this, What is space besides the empty whatever... volume (pick a synonym) in which "stuff" exists and moves. Space is to empty volume as dog is to angry bull terrier. 'Space' is not the same as 'empty volume' just like 'dog' is not the same as 'angry bull terrier'. They need to be the same.
owl Posted June 14, 2011 Author Posted June 14, 2011 (edited) I said: Summary: Time and space are not entities but rather just artifacts of measurement. ... and Cap ‘n R replied: That is not what I said. I said it is meaningless to speak of the "entities," because they are not observable. They may well exist, but science cannot characterize them, and opacity to experimentation means it does not matter what they "are." I was not quoting you but making a general summary statement. It would have been more clear if i had said “If time and space are not entities...” then how did “spacetime” become a malleable medium, curved by the gravity of mass? (More on this in my Ontology of Spacetime thread, see below.) Also, again (see yesterday's post), how does M-theory qualify as science by your comments yesterday and above? swansont said: Talking of time as a malleable entity is your strawman. So nothing is really “dilating” or expanding in “time diloation” but we speak as if there is out of tradition or group habit rather than being more precise in describing what we observe... which is clocks slowing down? swansont: Speaking of clock variability is too imprecise to be useful. Clocks can vary for reasons other than time dilation. I don’t understand this at all. Do they not routinely make very precise adjustments to GPS clocks (which vary in ticking rate) to yield precise positioning information? Yes, a wind-up clock submerged in water will slow down a lot, and no one would call it time dilation, but saying “time dilates” under other familiar conditions (changes in gravity field, velocity, etc.) does mean that something “time” is changing, not just the “ticking” rates of clocks? If there is a difference, what is it? To the conversation with Iggy: Me: "So defining time with a tautology is no problem for science." Iggy: All definitions are rhetorical tautologies. The word and the definition are one and the same, or at least they should be. You had trouble with this, Wikipedia: Tautology (rhetoric), using different words to say the same thing even if the repetition does not provide clarity. In the pseudo-"definition" of time as "that which clocks measure," "time=that" does not define time or "provide clarity" on what it is. On space... brought up here by Iggy with his Einstein quote on it... I said: What is space besides the empty whatever... volume (pick a synonym) in which "stuff" exists and moves. Iggy replied: Space is to empty volume as dog is to angry bull terrier. 'Space' is not the same as 'empty volume' just like 'dog' is not the same as 'angry bull terrier'. They need to be the same. Huh? (Seems like a lot of "bull" to me. ) Your Einstein quote said, again paraphrasing, that if all matter disappeared then all space and time would also disappear. I agreed with the 'time' part. Nothing moving... no time. I challenged the 'space' part. The disappearance of all matter would leave nothing... = empty space, call it what you will. (I did invite synonyms.) I will reply and comment on the link provided above by notimeforspacetime, in the Ontology of Spacetime thread in the Philosophy section. Edited June 14, 2011 by owl
md65536 Posted June 14, 2011 Posted June 14, 2011 I was not quoting you but making a general summary statement. It would have been more clear if i had said “If time and space are not entities...” then how did “spacetime” become a malleable medium, curved by the gravity of mass? Imagine a circle. What is it made of ("the ontological problem of the imaginary circle")? Is it curved? Can things that do not have physical presence (ie. non-entities) be curved? If no, then how did your imaginary circle become real? I don’t understand this at all. Do they not routinely make very precise adjustments to GPS clocks (which vary in ticking rate) to yield precise positioning information? Yes, a wind-up clock submerged in water will slow down a lot, and no one would call it time dilation, but saying “time dilates” under other familiar conditions (changes in gravity field, velocity, etc.) does mean that something “time” is changing, not just the “ticking” rates of clocks? If there is a difference, what is it? The difference is that in one situation (eg. due to gravity), all clocks slow down... ie. time dilates. In the other (eg. under water), not all clocks slow down. So for example if you put a clock underwater you can see that it's slowing down, but if you're traveling at near c with a clock, you can't see any change in time (in fact there is none relative to you) because your brain is also affected the same way that the clock is. Time dilation is only experienced relatively, from other frames of reference. AND because there is no privileged frame of reference, you cannot say that a clock is absolutely slowing down, from within an inertial frame of reference. If this doesn't make sense, it is because relativity is a very confusing thing to get, at many different levels (from general concept to exact details of particular examples), and you're not going to understand it without researching it. I could not and would not try to explain it all in an internet forum. "So defining time with a tautology is no problem for science." All this evaluation of wording is beside the point. The point is: - time is well-defined and consistent - its definition is meaningful, in that it applies to aspects of real-world observations (unlike your example of auras and aura-meters) - it is complete in that the definition ("time is what clocks measure") does not fail to account for any "time-like notions of reality". Sorry my wording is not exactly scientific. Any proposed evidence to the contrary would be interesting.
swansont Posted June 14, 2011 Posted June 14, 2011 So nothing is really “dilating” or expanding in “time diloation” but we speak as if there is out of tradition or group habit rather than being more precise in describing what we observe... which is clocks slowing down? I didn't say it was nothing; again that is you creating a straw man to tear down. I think we are precise in how time is described: it is what is measured by a clock. Length is what is measured by a meter stick. The basic problem here is the same as with language — you cannot define all words uniquely, i.e. without using definitions circularly. Sooner or later you have to point to a rock and say "this is a rock" I don’t understand this at all. Do they not routinely make very precise adjustments to GPS clocks (which vary in ticking rate) to yield precise positioning information? Yes, a wind-up clock submerged in water will slow down a lot, and no one would call it time dilation, but saying “time dilates” under other familiar conditions (changes in gravity field, velocity, etc.) does mean that something “time” is changing, not just the “ticking” rates of clocks? If there is a difference, what is it? Yes, you make these adjustments to GPS, because they are time dilation effects. But not all clock variability is due to time dilation. Temperature, humidity, electric field, magnetic field — all of these can change clock rates too. The difference is that in one situation (eg. due to gravity), all clocks slow down... ie. time dilates. In the other (eg. under water), not all clocks slow down. I'd go one step further and say that in the examples of relativity, all clocks slow down by exactly the same amount, whereas for some environmental influence, it depends on the clock.
owl Posted June 15, 2011 Author Posted June 15, 2011 swansont: I didn't say it was nothing; again that is you creating a straw man to tear down. The ontology of time (what is it?) is still not a straw man. If it is not an entity but it is not "nothing," (the process of eliminating what it is not), we still have not answered "what is it?" I think we are precise in how time is described: it is what is measured by a clock. Length is what is measured by a meter stick. And, again, how is this different than the bogus tautology defining "the aura" as "that which aurameters measure? How is time more than the duration of physical events? What slows down besides the duration of physical processes slowing down, say in higher gravity fields or higher velocities? Do you agree with the following Lisa Zyga quote from the Psyorg.com link: http://www.physorg.com/news/2011-04-scientists-spacetime-dimension.html In other words, what experimentally exists are the motion of an object and the tick of a clock, and we compare the object’s motion to the tick of a clock to measure the object’s frequency, speed, etc. By itself, t has only a mathematical value, and no primary physical existence. swansont: The basic problem here is the same as with language — you cannot define all words uniquely, i.e. without using definitions circularly. Sooner or later you have to point to a rock and say "this is a rock" So, if we can not include the properties of time or a description of it in a definition (like a dog is a four-legged canine mammal... etc), what can we "point to and say," this is time? What is wrong, if anything, with the Zyga quote above on time? Yes, you make these adjustments to GPS, because they are time dilation effects. But not all clock variability is due to time dilation. We all get that velocity and gravity effect clocks' ticking rates, and that we call this effect "time dilation"... as distinct from other things we can do to clocks to slow them down. Yet we don't seem to know what it is that is said to "dilate" besides the obvious fact that clocks slow down. What about the Sorli quote from the Zyga article?: Einstein said, "Time has no independent existence apart from the order of events by which we measure it." Time is exactly the order of events: this is my conclusion....In this 3D space there is no ‘length contraction,’ there is no ‘time dilation.’ What really exists is that the velocity of material change is ‘relative’ in the Einstein sense. And I've been persistent in my argument against the relativity dictum that everything is relative to measurement. A couple of my recent statements in this regard: My point was that physical processes even in “galaxies far, far away” "take time to happen” (event duration) naturally, objectively, in the real world regardless of “measurement” by any definition.and: So the whole cosmos and all of its moving parts, being physical processes which "take time" to happen, have no "duration" (elapsed time) unless and until each event is "measured?" The same ontology applies to "length contraction" in reply to your, " Length is what is measured by a meter stick" (which is supposed to vary with different frames of reference.) I asked (again) recently if anyone actually believes that earth's diameter or earth-sun distance actually varies with different frames of reference from which they are measured. Apparently no one wants to look foolish enough to affirm contraction/expansion of that diameter or the one AU distance, but relativity's "length contraction" insists on their variability.
owl Posted June 15, 2011 Author Posted June 15, 2011 (edited) md65536: All this evaluation of wording is beside the point.The point is: - time is well-defined and consistent - its definition is meaningful, in that it applies to aspects of real-world observations (unlike your example of auras and aura-meters) - it is complete in that the definition ("time is what clocks measure") does not fail to account for any "time-like notions of reality". Sorry my wording is not exactly scientific. Any proposed evidence to the contrary would be interesting. The point of this thread is to “evaluate” what time is in the real world, if anything more than the concept of event duration for any and all physical processes. The latter can speed up and slow down for a variety of reasons without making time itself into something that speeds up or slows down. Time is not defined at all by the “what clocks measure” dodge, and the variability of the latter is the opposite of “consistent.” “Real world observations” are physical processes with variable duration in different circumstances. Finally, I would like to put the "aurameter" example in honest perspective: Those who claim that living things have detectable energy fields beyond their physical boundaries are not necessarily all new-age dingbats, and they claim to have developed instruments (aurameters) to detect these energy levels on very subtle levels. (I was baiting the forum with this example to see if anyone actually knew anything about this field, or if blind prejudice would prevail. It did.) It is more likely, I think (being open minded as I am) that these “meters” are measuring actual ( though quite weak) energy fields than that clocks are measuring some real (whatever) “time” as a “thing” in the broadest sense besides “Event Duration of Physical Processes.” I will hereafter use the acronym EDPP to designate what I mean by “time.” Edited June 15, 2011 by owl
swansont Posted June 16, 2011 Posted June 16, 2011 The ontology of time (what is it?) is still not a straw man. If it is not an entity but it is not "nothing," (the process of eliminating what it is not), we still have not answered "what is it?" I didn't say that the ontology was a strawman, I said that calling it "nothing" was a strawman, and calling it an "entity" was a strawman. And, again, how is this different than the bogus tautology defining "the aura" as "that which aurameters measure? If auras were actually measurable and you lacked more basic concepts on which to base them, you might be forced to do that. How is time more than the duration of physical events? What slows down besides the duration of physical processes slowing down, say in higher gravity fields or higher velocities? What of a duration between events? Oh, but now you have to define what a duration is. So, if we can not include the properties of time or a description of it in a definition (like a dog is a four-legged canine mammal... etc), what can we "point to and say," this is time? A clock. It measures time. (Define four, leg, canine and mammal. And all the terms in those definitions) We all get that velocity and gravity effect clocks' ticking rates, and that we call this effect "time dilation"... as distinct from other things we can do to clocks to slow them down. Yet we don't seem to know what it is that is said to "dilate" besides the obvious fact that clocks slow down. And does this stop us from doing physics? No, apparently not. The same ontology applies to "length contraction" in reply to your, " Length is what is measured by a meter stick" (which is supposed to vary with different frames of reference.) I asked (again) recently if anyone actually believes that earth's diameter or earth-sun distance actually varies with different frames of reference from which they are measured. Apparently no one wants to look foolish enough to affirm contraction/expansion of that diameter or the one AU distance, but relativity's "length contraction" insists on their variability. I missed where you asked, but the answer is yes. That distance would contract. What is the nature of length, anyway? Why the obsession with time?
md65536 Posted June 16, 2011 Posted June 16, 2011 I asked (again) recently if anyone actually believes that earth's diameter or earth-sun distance actually varies with different frames of reference from which they are measured. Apparently no one wants to look foolish enough to affirm contraction/expansion of that diameter or the one AU distance, but relativity's "length contraction" insists on their variability. I believe it because it does vary. The distance between Earth and Sun is the distance between Earth and Sun according to any observer. Distance between Earth and Sun varies even without length contraction since Earth's orbit isn't a perfect circle (wikipedia says "The Earth is 1.00 ± 0.02 AU from the Sun").But an AU is defined as a number of meters, which vary due to length contraction. What doesn't vary is c, which I think is key to grounding all of these concepts and making them meaningful despite all the variability. (I was baiting the forum with this example to see if anyone actually knew anything about this field, or if blind prejudice would prevail. It did.) Curses! You've once again proven me a fool by my taking of your bait and replying to your posts!
Recommended Posts