md65536 Posted January 4, 2012 Posted January 4, 2012 I said that I am done with this, but I changed my mind. LOL owl, So is Earth orbiting the sun clockwise or counter-clockwise? Realism demands a non-frame dependent answer as it does for the diameter of the earth. Answer the question and stop repeating yourself. Im applying the same standards to realism that you have required of special relativity. So don't claim that I'm missing the point. Pony up and make a definitive statement. Honestly I think this line of reasoning is a digression. No one (not even owl) is claiming that there is a "real" rotation of the Earth that disagrees with science. Every observer should agree on the direction of the Earth's rotation relative to the sun. What's in contention is whether everyone agrees on the distance between the Earth and sun. Further, everyone agrees that every observer agrees on what a particular observer will measure (such as an observer on the surface of the Earth, measuring a certain Earth diameter and certain distance to the sun). owl's mistake is in assuming that everything that applies to one observer applies to every observer. The "rotation of the Earth" thought experiment is useful for helping someone realize the concept of relative measurements, but if owl hasn't already got it I don't think it's going to work for him.
mississippichem Posted January 4, 2012 Posted January 4, 2012 (edited) LOL Honestly I think this line of reasoning is a digression. No one (not even owl) is claiming that there is a "real" rotation of the Earth that disagrees with science. Every observer should agree on the direction of the Earth's rotation relative to the sun. What's in contention is whether everyone agrees on the distance between the Earth and sun. Further, everyone agrees that every observer agrees on what a particular observer will measure (such as an observer on the surface of the Earth, measuring a certain Earth diameter and certain distance to the sun). owl's mistake is in assuming that everything that applies to one observer applies to every observer. The "rotation of the Earth" thought experiment is useful for helping someone realize the concept of relative measurements, but if owl hasn't already got it I don't think it's going to work for him. It is most certainly a digression. Owl demands that there is a prefered frame of reference (though he may not admit it, his argument unavoidably implies such). Im simply forcing on him the same dichotomy he has pushed on relativity. Childish reasoning...perhaps, the argument has degraded to such a level as a result of owl's constant goal post shifting and semantics picking. Edited January 4, 2012 by mississippichem
owl Posted January 4, 2012 Author Posted January 4, 2012 (edited) Swansont: It's OK to say that you don't know the details. I'd venture to guess that most people don't; not really a fair question on my part. We'll stick to the ruler/meter stick, since that's a much more common instrument. You have no idea what details I know and don’t know. Both meters measure ‘things.” * Clocks don’t. The “things they measure, as per your nit picking: This is more subtle than you might think. Detect and measure are not synonymous. I have an ammeter that measures current, but what it detects is magnetic field. A power meter that measure power but detects the change in resistance from a temperature change. A thermometer that measures temperature but detects photons. So you derail the 'what clocks measure' (or not!) point with this about what real meters detect vs what they measure. Sorry, just more avoidance of the point that the two meters detect/measure forces/photons, etc. and that clocks detect/measure nothing. They are simply engineered to “tick.” The ontology of time is again/still over your head. S: I notice you have not raised any objections to any of these measurements (current, intensity, length) reifying the quantities they measure. Right. The real world has these forces and photons and distances between objects which real meters detect (in whatever technical form) and measure and which lightspeed can measure as lightyears on cosmic scale, rather than a whole lot of meter sticks. Clocks are not meters detecting and measuring “time.” It might be difficult for you, but you could concede the point. Clocks neither detect or measure anything. To claim that they do reifys time. So we have an item that is 60 cm long, and we put the meter stick next to it and see that the difference in the endpoints is 60 cm. So now a meter stick is 120 cm long, or did I misunderstand what your “endpoints” were? Par for the course for no communication between us. I would have thought that 40 cm would be the difference. (Trivial... so you mis-spoke, I presume.) S: A clock is simply a device that has been calibrated for a particular duration. It is, in that basic concept, no different than a meter stick: a calibrated length of time with which me may compare things. So I don't understand why you say that a clock does not measure elapsed time. Like I said, engineered to tick... Unlike meters which are engineered to detect and measure things/forces. So we can compare clocks in different frames and get different elapsed times for such natural events as an Earth rotation, because they vary in rates of ticking. Earth does not vary in elapsed time for a rotation. Can you still not grasp the difference? Same with the meter stick. It gives us a standardized measure of length with which we can “measure” distances, as I covered in detail in last post. Simple. But Earth’s size does not change with variations in the appearance of a meter stick from extreme frames. (Realism. Applied philosophy of science.) S: I don't think anyone here has claimed that a clock detects time (that would be reifying it, no?). A clock measures time, but what it detects is oscillations, which have a well-specified duration. Well specified are they... except that they vary a lot in different environments... unlike the natural elapsed time of events which clocks are said to "measure" and to which they assign time units. Take an Earth rotation... variable in reality as according to different clocks or not? How long would it take to get to Alpha Centauri at sub-light speed... in the real cosmos? A lot less that 4.3 years, as according to the ship clock/calendar and "contracted length" or a lot more because it can't go faster than light, which requires 4.3 years to travel the actual distance. I know, you don't believe in actual distance, but that is where realism differs from length contraction idealism... that it all depends on frame of reference. I will wait breathlessly for your answer to the above challenge. "LOL." (First ever usage for me. I usually just chuckle quietly under such sniper fire.) It is most certainly a digression. Owl demands that there is a prefered frame of reference (though he may not admit it, his argument unavoidably implies such). Im simply forcing on him the same dichotomy he has pushed on relativity. Childish reasoning...perhaps, the argument has degraded to such a level as a result of owl's constant goal post shifting and semantics picking. I have "admitted" many times that I not only disagree with the "no preferred frame of reference dictum" but insist that as close as we can get to an at rest frame with the object/distance measured is "preferable." The principles of experimental design are quite reasonable. "What shape is Earth?" What frame of reference will give us the most accurate results to answer that question? Yada yada. (Too many repetitons already.) How thick is Earth's atmosphere? Shall we go with all the observations known to Earth science or look at it from a muon's frame? Natural muons in the atmosphere "live" longer that lab muons in an accelerator, so they say. So they travel further than expected, based on the latter, shorter 'lifespan.' 'So, therefore Earth's atmosphere is a lot thinner (shorter distance through it) than what atmospheric science has known for a long time. This is how philosophy of science can help us understand such absurd assumptions as "for a muon" (it's a very much thinner atmosphere)... after all, their frame of reference is "equally valid" according to the length contraction theory of SR. Edited January 4, 2012 by owl
Iggy Posted January 4, 2012 Posted January 4, 2012 It is most certainly a digression. Owl demands that there is a prefered frame of reference (though he may not admit it, his argument unavoidably implies such). Im simply forcing on him the same dichotomy he has pushed on relativity. Childish reasoning...perhaps, the argument has degraded to such a level as a result of owl's constant goal post shifting and semantics picking. I don't think it's childish. Another property by which you could inquire would be velocity, ...everything is moving and velocity requires specificity as to "moving how fast relative to what."... Why are velocity and direction relative while length and duration not? When it finally boils down to 'my unsupported worldview wants it to be that way despite what measurement, logic, science, and philosophy tell me'... well... I think that's usually when people stop leading the horse to the water it refuses to drink. 1
owl Posted January 5, 2012 Author Posted January 5, 2012 A philosophical side note here: "Relative to what?" is a very basic question in the physics of velocity and in the larger scope of cosmology. We all (most of us anyway) know the basics of "velocity relative to what?" The moving car rel. to the road. A milepost on the road rel. to the center of our spinning Earth. Earth relative to Sun. Sun rel. to center of Milky Way Galaxy. All galaxies are moving away from each other at whatever velocity rel. to each other (combined vectors rel. to an abstract mid-point, maybe.) And what about cosmic expansion rate?? Relative to what? Relativity theorists should ask themselves what the scope of the theory covers. Beyond an imagined (sorry, 'theorized') "shape of the cosmos"... just infinite empty space or more cosmoses (cosmi ?) like (or very different than) ours. For those who think all serious science is contained in equations... philosophy... even "free thinking" or simply "musing" has a place in the vision which leads science to new discoveries. End of sermon... or speculation... or whatever. It's "just philosophy." Easily dismissed as "navel gazing."
swansont Posted January 5, 2012 Posted January 5, 2012 You have no idea what details I know and don’t know. Fair enough, but it raises the question of why you gave such a vague answer if you actually know the details. Both meters measure ‘things.” * Clocks don’t. So, current is a thing, and light intensity is a thing? Length is a thing? Intensity is energy per unit area — is energy a thing, and area a thing? Current is charge per unit time. But time isn't a thing, so how can current be a thing? Clocks measure (i.e. count) oscillations. Surely oscillations are a thing. Oscillations have a duration (and duration is not a thing — it has the owl "non-reified" stamp of approval.) Which part of that is untrue? Why isn't keeping track of duration a measurement of time? The “things they measure, as per your nit picking: So you derail the 'what clocks measure' (or not!) point with this about what real meters detect vs what they measure. Sorry, just more avoidance of the point that the two meters detect/measure forces/photons, etc. and that clocks detect/measure nothing. They are simply engineered to “tick.” The ontology of time is again/still over your head. On the contrary, I simply think you are wrong. And the fact that you have to shape the argument a certain way in order to knock it down gives me confidence that I am correct in my assessment. You keep challenging things that nobody has claimed to be true, like that clocks "detect" time. Right. The real world has these forces and photons and distances between objects which real meters detect (in whatever technical form) and measure and which lightspeed can measure as lightyears on cosmic scale, rather than a whole lot of meter sticks. Clocks are not meters detecting and measuring “time.” It might be difficult for you, but you could concede the point. Clocks neither detect or measure anything. To claim that they do reifys time. I refer you to my above argument. If you claim that clocks measure nothing, I submit you don't know how a clock works. So now a meter stick is 120 cm long, or did I misunderstand what your “endpoints” were? Endpoints of the object. One end at the zero mark, the other at 60. Like I said, engineered to tick... Unlike meters which are engineered to detect and measure things/forces. Again, this implies length is a thing. Is length something you can give to someone else? So we can compare clocks in different frames and get different elapsed times for such natural events as an Earth rotation, because they vary in rates of ticking. Earth does not vary in elapsed time for a rotation. Can you still not grasp the difference? Same with the meter stick. It gives us a standardized measure of length with which we can “measure” distances, as I covered in detail in last post. Simple. But Earth’s size does not change with variations in the appearance of a meter stick from extreme frames. (Realism. Applied philosophy of science.) Well specified are they... except that they vary a lot in different environments... unlike the natural elapsed time of events which clocks are said to "measure" and to which they assign time units. If you want to convince me that the change in clock rate is simply an environmental affect, what is the detectable environmental effect that changes the clock rate, i.e. the duration of the oscillation? 1
mississippichem Posted January 5, 2012 Posted January 5, 2012 I have "admitted" many times that I not only disagree with the "no preferred frame of reference dictum" but insist that as close as we can get to an at rest frame with the object/distance measured is "preferable." The principles of experimental design are quite reasonable. "What shape is Earth?" What frame of reference will give us the most accurate results to answer that question? Yada yada. (Too many repetitons already.) How thick is Earth's atmosphere? Shall we go with all the observations known to Earth science or look at it from a muon's frame? Natural muons in the atmosphere "live" longer that lab muons in an accelerator, so they say. So they travel further than expected, based on the latter, shorter 'lifespan.' 'So, therefore Earth's atmosphere is a lot thinner (shorter distance through it) than what atmospheric science has known for a long time. This is how philosophy of science can help us understand such absurd assumptions as "for a muon" (it's a very much thinner atmosphere)... after all, their frame of reference is "equally valid" according to the length contraction theory of SR. If it is so simple. Stop dodging and answer my question. Is the Earth orbiting the sun counter-clockwise or clockwise? You now admit to a prefered frame so which is it? Why do you never directly answer questions? For fear of error?
owl Posted January 5, 2012 Author Posted January 5, 2012 (edited) If it is so simple. Stop dodging and answer my question. Is the Earth orbiting the sun counter-clockwise or clockwise? You now admit to a prefered frame so which is it? Why do you never directly answer questions? For fear of error? I answered this already maybe a dozen or so times if you include the Earth's direction of spin... same principle. Read my posts to TAR clarifying my answers. Basic realism: Earth's directions of spin and orbit do not depend on how we look at them. Clockwise and counterclockwise are observation dependent terms. The "direction" depends on our perspective in each case. Another repeat, just for you: From above the North Pole, Earth is spinning counterclockwise. From above the South Pole, Earth is spinning clockwise. Obviously Earth does not reverse direction of spin. Same goes for direction of Earth's orbit around the Sun as seen from above Suns' North Pole... counterclockwise.... That means, from the side of the plane of the ecliptic corresponding with Earth's North Pole Here is Wikipedia on Earth's Orbit; (I didn't invent the concept): Viewed from a vantage point above the north poles of both the Sun and the Earth, the Earth appears to revolve in a counterclockwise direction about the Sun. Fair enough, but it raises the question of why you gave such a vague answer if you actually know the details. My point, which you attempted to avoid by bickering about the difference between detection and measurement, was this: Ammeters (tks for spelling correction) measure electric current. We all know what that is without bickering about whether or not it is a thing. (I say yes. Forces/currents are also things.) Light meters measure "how much light" is reflected from a subject of photography, for instance. Yes, light is a thing. Both instruments are engineered to "detect and measure" those "things." Clocks are engineered to oscillate as precisely regularly as possible. Yes, oscillations are things too. But clocks are not designed to detect or measure anything. We just record the 'seconds' and 'minutes' and 'hours' they tick off as other physical events happen and assign duration to the latter events... and we call it elapsed time. ( Or, regardless of "clocking events" as above, clocks will "tick off" seconds and minutes and hours, as they are designed to do. Very elementary.) On the contrary, I simply think you are wrong. And the fact that you have to shape the argument a certain way in order to knock it down gives me confidence that I am correct in my assessment. You keep challenging things that nobody has claimed to be true, like that clocks "detect" time. I have studied many authors on the ontology of time over the years, and yours is a prime example of the reification of time. I gave two very clear examples. I'll repeat them. Two clocks at different velocities will "clock" one rotation of Earth differently. If time is "that which clocks measure," then the elapsed time for on rotation, a day, will vary with which clock is measuring it. But that is clearly false, as it reifies "clock time" and ignores the fact that an Earth day has its own elapsed time, not depending on how variably it is measured. It would be the same elapsed time, event duration of the physical process of rotating, in the real world without clocks clocking it. You never replied to this point. You will most likely avoid it again. The other example was elapsed time for a high speed trip to Alpha Centauri. It takes light 4.3 years to go the distance. (Yes, distance is a real "thing"... the linear component of the space between points or objects. But stars don't move closer together or further apart with the bogus concept of length contraction.) A high speed ship must go less than lightspeed, so therefore it will take the ship more than 4.3 years to get there. That is logic. But the ship's clock will have slowed down and will tell the crew that less that 4.3 years have "passed." Clock's rates of ticking vary at different velocities... We agree on that. What "passed" above,... a fraction of 4.3 years or more than 4.3 years? Answer that and you may see how you reify time. I refer you to my above argument. If you claim that clocks measure nothing, I submit you don't know how a clock works. See my detailed explanation above. Endpoints of the object. One end at the zero mark, the other at 60. You placed an item next to a meter stick and then referred to "The difference in the endpoints." I took it to mean between endpoint of the meter stick and endpoint of the 60 cm item... 40 cm, and you sounded confused. Again, this implies length is a thing. Is length something you can give to someone else? Length is a measure of distance... one end of the meter rod to the other or from here to the closest star. Contrary to the claims of length contraction, the meter rod does not shrink when observed from a high speed reference frame, and neither does the distance to Alpha Centauri. (Ho hum. Boring.) If you want to convince me that the change in clock rate is simply an environmental affect, what is the detectable environmental effect that changes the clock rate, i.e. the duration of the oscillation? I include high velocity and high gravity fields as different environments, which I thought was obvious. I said (several times) that I don't know how the above changes in environment effect the rate of oscillation in clocks. I asked you to "enlighten all of us" if you do know. No answer, as usual. Edited January 5, 2012 by owl
swansont Posted January 5, 2012 Posted January 5, 2012 My point, which you attempted to avoid by bickering about the difference between detection and measurement, was this: Ammeters (tks for spelling correction) measure electric current. We all know what that is without bickering about whether or not it is a thing. (I say yes. Forces/currents are also things.) Light meters measure "how much light" is reflected from a subject of photography, for instance. Yes, light is a thing. Both instruments are engineered to "detect and measure" those "things." Clocks are engineered to oscillate as precisely regularly as possible. Yes, oscillations are things too. But clocks are not designed to detect or measure anything. So, according to you, counting oscillations is not a measurement, but counting photons or electrons is. Do you see why I find this confusing? We just record the 'seconds' and 'minutes' and 'hours' they tick off as other physical events happen and assign duration to the latter events... and we call it elapsed time. ( Or, regardless of "clocking events" as above, clocks will "tick off" seconds and minutes and hours, as they are designed to do. Very elementary.) Still not clear to my why getting a value for elapsed time is not a measurement in your lexicon. Comparing to a known, calibrated standard is what most people mean by a measurement. I have studied many authors on the ontology of time over the years, and yours is a prime example of the reification of time. I gave two very clear examples. I'll repeat them. Two clocks at different velocities will "clock" one rotation of Earth differently. If time is "that which clocks measure," then the elapsed time for on rotation, a day, will vary with which clock is measuring it. But that is clearly false, as it reifies "clock time" and ignores the fact that an Earth day has its own elapsed time, not depending on how variably it is measured. It would be the same elapsed time, event duration of the physical process of rotating, in the real world without clocks clocking it. You never replied to this point. You will most likely avoid it again. Stating that "an Earth day has its own elapsed time, not depending on how variably it is measured" is a philosophical position that you are claiming is true, as you have all along, but you have not shown it to be true. It also says that the length of a day can be measured, which I thought you said was impossible. Does "clocks don't measure anything" ring a bell? Which is it? Does a rotation measure the length of a day or not? The other example was elapsed time for a high speed trip to Alpha Centauri. It takes light 4.3 years to go the distance. (Yes, distance is a real "thing"... the linear component of the space between points or objects. But stars don't move closer together or further apart with the bogus concept of length contraction.) A high speed ship must go less than lightspeed, so therefore it will take the ship more than 4.3 years to get there. That is logic. But the ship's clock will have slowed down and will tell the crew that less that 4.3 years have "passed." Clock's rates of ticking vary at different velocities... We agree on that. What "passed" above,... a fraction of 4.3 years or more than 4.3 years? Answer that and you may see how you reify time. It depends on the frame of reference. To those on the ship, the duration of the event will be less than 4.3 years. To an observer on earth, the event duration is more than 4.3 years. Linear component of the space? What do you mean by space? Is space a real thing? I include high velocity and high gravity fields as different environments, which I thought was obvious. There is no test one can do to see if one is moving or stationary. You can only measure movement relative to something else. You also can't tell the difference between gravity and any other acceleration. Which raises the question of how gravity (or acceleration) physically affects the clock rates. I said (several times) that I don't know how the above changes in environment effect the rate of oscillation in clocks. I asked you to "enlighten all of us" if you do know. No answer, as usual. Really? My answer is relativity, which you deny. To avoid the figurative language you claim results in reification, I have to use math. Is there any point in going into the details?
owl Posted January 6, 2012 Author Posted January 6, 2012 (edited) So, according to you, counting oscillations is not a measurement, but counting photons or electrons is. Do you see why I find this confusing? [/Quote] Yes, I do, but I am not allowed here to say why, and I don't think that blatant insults help the conversation. This is so tedious. (Do you teach? What is your specialty?) How many times must one explain the difference between a true meter and a clock. One is designed to detect and measure 'things' (as stipulated above) and the other designed to "tick" very regularly. So when physics proclaims that "Time is that which clocks measure"... we must distinguish between elapsed time between 'ticks' of the clock and elapsed time of the natural event a clock is set to "measure." Science describes natural phenomena. How long is a day? As long as a vast number of identical atomic clocks in different frames of reference relative to Earth say it is?? What happened to the exact measurement of a natural day, a rotation of our planet, an objective physical process... in the various clock "measurements." Swansont; If you have any comprehension of what I just said, please reply to my point as stated. Still not clear to my why getting a value for elapsed time is not a measurement in your lexicon. Comparing to a known, calibrated standard is what most people mean by a measurement. Maybe the above reply explained it. If not... I dunno. Allow a non-sequitur. Do you believe that time travel is possible? This is important for the issue of time reification. Stating that "an Earth day has its own elapsed time, not depending on how variably it is measured" is a philosophical position that you are claiming is true, as you have all along, but you have not shown it to be true. It also says that the length of a day can be measured, which I thought you said was impossible. Does "clocks don't measure anything" ring a bell? Which is it? Does a rotation measure the length of a day or not? I find your level of comprehension of what I say very discouraging. Realism... Try to imagine beyond frames of reference observing different shapes of Earth... to the possibility of a "true shape of Earth" which it is the job of science to discern. This might help. (tho it has not before...): Try very hard to imagine a cosmos with no intelligent life. Got it? (Or can there be no unobserved cosmos... How absurd is that?!) Did we intelligent observers create the Earth and cosmos by observing it... being different from all points of view? I hope you agree that we didn't. So with or without our clocks ticking out the hours in a day, variously from different 'environments', and with or without life on Earth, for that matter, realism is the real-ization that the elapsed time for an Earth rotation is what it is, independent of measurement. It need not be 'called' 24 hours or any of its fractions which clocks "measure" differently as to their inertial enviroment. It depends on the frame of reference. To those on the ship, the duration of the event will be less than 4.3 years. To an observer on earth, the event duration is more than 4.3 years. There you go again! There is no actual distance ("Length is Not Invarient"... repeat, "Length is Not Invarient", ... repeat)... to Alpha Centauri, as astronomy asserts... (4.3 lightyears as measured by the constant speed of light.) It all depends on frame of reference. Cosmos has no intrinsic reality. We humans create our own reality... at our own leisure... according to the speed we choose to travel. Idealism..... vs Realism. 'We can make the trip much faster than light, because our clocks tell us so.' This is way over the top, philosophically, and you can't even see it. Linear component of the space? What do you mean by space? Is space a real thing? Visit the "something from nothing" thread in this section. Physicists attribute "properties" to space (curvature, shape, expandability.) That, ontologically makes space an entity. It reifies space. Maybe you should brush up on, or a least begin to study some ontology. (Don't tell your physics friends!) Space is empty volume. (Volume has three axes, called "dimensions.") How real do you think empty space is? Empty means no things. Of course, where there are "things" space is not empty. (Basics seem important here... like ontology of space from scratch.) Anyway, since space is volume and distance between points or objects in space is a straight line (one dimensional) I call that aspect of the volume between objects "the linear component of space"... length or distance. There is no test one can do to see if one is moving or stationary. You can only measure movement relative to something else. You also can't tell the difference between gravity and any other acceleration. Which raises the question of how gravity (or acceleration) physically affects the clock rates. Review my very recent post on the relativity of velocity (what relative to what.) Ask if you need directions. Very tired of repeating. Yes, yet again, do you pretend to know how gravity or acceleration and different velocities effects clock rates? I've asked three times now for you to tell us all if you know. Really? My answer is relativity, which you deny. To avoid the figurative language you claim results in reification, I have to use math. Is there any point in going into the details? X 99 or so... I do not deny relativity*. How dense can you be?! *I deny "time dilation", "length contraction", and (as per GR,) "curved spacetime." The rest of last paragraph was unintelligible. But there is probably no point anyway... because there is no communication here, even when I 'ask nice' and repeatedly for replies to my inquiries and challenges. Is "relativity" an answer to what forces slow clocks down at high speeds and gravity fields? Hell no! Get a grip. Learn some ontology and respect for philosophy of science! Edited January 6, 2012 by owl -1
Iggy Posted January 6, 2012 Posted January 6, 2012 That is logic. But the ship's clock will have slowed down and will tell the crew that less that 4.3 years have "passed." Clock's rates of ticking vary at different velocities... We agree on that. Earth’s size does not change with variations in the appearance of a meter stick from extreme frames. If I understand you, clocks really do slow down when velocity changes, but meter sticks don't really shrink -- they just appear to from the mistaken perspective of others. If you have a clock and a meter stick you can measure how long it takes light to travel the distance of the meter stick (it's 0.3 billionths of a second). Then if you change speed, according to you; your clock would slow down and the meter stick will stay the same size. How far does light get in .3 billionths of a second on the now slower clock? An example: (Yes, distance is a real "thing"... the linear component of the space between points or objects. But stars don't move closer together or further apart with the bogus concept of length contraction.) A high speed ship must go less than lightspeed, so therefore it will take the ship more than 4.3 years to get there. That is logic. But the ship's clock will have slowed down and will tell the crew that less that 4.3 years have "passed." Clock's rates of ticking vary at different velocities... We agree on that. If the clock on the ship really did slow down, as you say, then maybe it measured a year from the start to the end of the trip. If the people on that ship measured how long it took light to get from earth to Alpha Centauri -- with their own clock -- they would find it went 4.3 lightyears in about a year... 4.3 lightyears per year. The astronauts would measure light moving 4.3 times the value earthlings measure it with their clock. If clocks really slowed down, but meter sticks didn't really shrink, people going different velocities would get different experimental values for the speed of light. The speed of light has been tested from different velocities and it is invariant. Another thing you may not have considered: you are happy thinking that the ship clock slows down with velocity (it goes slower than earth clocks), does this mean earth clocks run faster than the clocks on the ship? That being the case, any clock on a probe sent speeding from the ship towards Alpha Centauri would slow down, while a clock sent on a probe in earth's direction would speed up. People could find a state of absolute rest by sending clocks in different directions and seeing which slow down and which speed up. We don't see that sort of anisotropy experimentally. You could also compare a couple different assessments you've made: that earth rotates at the same speed regardless of frame of reference. It doesn't slow down or speed up with velocity. Clocks, on the other hand, you say do slow down with velocity. If the minute hand of a stopwatch really does slow down (rotate slower) when it has a velocity of 30 km/s relative to us, then what about Alpha Centauri which has the same velocity? Does it rotate slower? How could you hold that clocks tick with less frequency at greater velocity, but stars and planets don't rotate slower with velocity. Perhaps it's easy to imagine clocks slowing down because they are small, but hard to imagine planets slowing down because they are so big. Nonetheless, observation shows that the duration of a process as large as supernova depends on velocity just like the duration of a process as small as an atomic clock. So it clearly wouldn't be consistent to say that the process of a clock ticking really does slow with velocity, but the process of a planet rotating or a star exploding doesn't.
swansont Posted January 6, 2012 Posted January 6, 2012 Yes, I do, but I am not allowed here to say why, and I don't think that blatant insults help the conversation. Innuendo is fine, though, if one follows your lead. (Doesn't seem to keep you from complaining when others do it, though) This is so tedious. (Do you teach? What is your specialty?) I have taught. Topics in both physics and nuclear reactor engineering. How many times must one explain the difference between a true meter and a clock. One is designed to detect and measure 'things' (as stipulated above) and the other designed to "tick" very regularly. But a clock detects oscillations, which you have agreed are things. So you are applying this definition inconsistently. Why is counting oscillations not a measurement of the number of oscillations? So when physics proclaims that "Time is that which clocks measure"... we must distinguish between elapsed time between 'ticks' of the clock and elapsed time of the natural event a clock is set to "measure." Science describes natural phenomena. How long is a day? As long as a vast number of identical atomic clocks in different frames of reference relative to Earth say it is?? What happened to the exact measurement of a natural day, a rotation of our planet, an objective physical process... in the various clock "measurements." The clocks used by the official timekeepers around the world adjust their clock outputs to keep them in the same frame; clocks are adjusted for their height above the geoid, and time transfer is adjusted for rotation effects. "Day" is a poor unit of measurement as it turns out, because the duration of a day is variable as compared to the duration of other phenomena, owing to rotation and orbital effects. That's one reason we define the length of the second. Days, however, generally aren't exactly 86400 seconds long — the earth is a poor clock. (from a scientific perspective) Do you believe that time travel is possible? This is important for the issue of time reification. Relativity narrows the possibilities, but does not yet completely rule it out. Now, a non-sequitur of my own: do you own a watch or clock of any sort? I find your level of comprehension of what I say very discouraging. Realism... Try to imagine beyond frames of reference observing different shapes of Earth... to the possibility of a "true shape of Earth" which it is the job of science to discern. I disagree with the premise. It is not science's job to discern the "true shape of the earth". Realism is not a premise of science. And we discover evidence indicating that it is not true. Science's job is to discover the true behavior of nature, and realism is not how nature behaves. If one's approach is that science's job is to determine reality, then the reality is that some parameters that science measures are invariant and some are not; realism is false. (So is idealism) This might help. (tho it has not before...): Try very hard to imagine a cosmos with no intelligent life. Got it? (Or can there be no unobserved cosmos... How absurd is that?!) Did we intelligent observers create the Earth and cosmos by observing it... being different from all points of view? I hope you agree that we didn't. So with or without our clocks ticking out the hours in a day, variously from different 'environments', and with or without life on Earth, for that matter, realism is the real-ization that the elapsed time for an Earth rotation is what it is, independent of measurement. It need not be 'called' 24 hours or any of its fractions which clocks "measure" differently as to their inertial enviroment. Imagine there is an intelligent being, moving very fast toward us. He has a clock that uses the same standard as ours — the duration of a second. He measures how long an earth rotation takes, and comes up with some number, significantly different from 86400. That has no effect on what people on earth say it is or experience. The exact same thing will happen if the intelligent being is at rest and the earth is moving toward him at high speed. —— It depends on the frame of reference. To those on the ship, the duration of the event will be less than 4.3 years. To an observer on earth, the event duration is more than 4.3 years. There you go again! There is no actual distance ("Length is Not Invarient"... repeat, "Length is Not Invarient", ... repeat)... Where did I mention distance? You asked how long the trip took and assured me that you would use my answer to show reification. Physicists attribute "properties" to space (curvature, shape, expandability.) That, ontologically makes space an entity. It reifies space. Maybe you should brush up on, or a least begin to study some ontology. (Don't tell your physics friends!) Or, perhaps, it's a matter of language, and there is the possibility that figurative language is being used that you are taking literally. "Space" is used in math to describe a system with an associated set of rules; a function space. "Minkowski space", for example, or "Hilbert space". A function space can have an infinite number of dimensions, and you're the only one in the room that thinks that you have reified anything by calling it a space. Space is empty volume. (Volume has three axes, called "dimensions.") How real do you think empty space is? Empty means no things. Of course, where there are "things" space is not empty. (Basics seem important here... like ontology of space from scratch.) Anyway, since space is volume and distance between points or objects in space is a straight line (one dimensional) I call that aspect of the volume between objects "the linear component of space"... length or distance. But you just got done implying that reifying space is bad. So if space is not a thing, how can there be any properties of space that can be measured? How can length be real? Review my very recent post on the relativity of velocity (what relative to what.) Ask if you need directions. Very tired of repeating. Yes, yet again, do you pretend to know how gravity or acceleration and different velocities effects clock rates? I've asked three times now for you to tell us all if you know. X 99 or so... I do not deny relativity*. How dense can you be?! *I deny "time dilation", "length contraction", and (as per GR,) "curved spacetime." Time dilation, length contraction and curved spacetime ARE relativity. The rest of last paragraph was unintelligible. But there is probably no point anyway... because there is no communication here, even when I 'ask nice' and repeatedly for replies to my inquiries and challenges. Is "relativity" an answer to what forces slow clocks down at high speeds and gravity fields? Hell no! Get a grip. Learn some ontology and respect for philosophy of science! It's not a force, and nobody has claimed it is a force. That's a huge point. From the perspective of relativity, it's not a mechanical effect like friction is. If you deny time dilation, then it is you who is requiring that there be a force. I'm asking what it is. If you can't provide it than this is worthless, scientifically, and so the ontology adds no value to science. I'll have some respect for philosophy of science when you can demonstrate that it has added anything to the goal of science: knowing how nature behaves. "No, that's wrong" doesn't add to understanding. Learn some science and respect for what it has achieved. 1
PeterJ Posted January 6, 2012 Posted January 6, 2012 In its defence, I would not see Owl's view as an endorsement of philosophy of science but as a rather odd view of it. I understand his frustration with the refusal of physics not to address ontological questions, or at least to treat them as important, but it is their right and a part of their method. This is how physics is defined, how it's done, what stops it being cluttered up with troublesome metaphysical issues. Metaphysics does not build power stations. The term 'fundamental physics' means 'as fundamental as physics gets', and shouldn't mislead us into thinking that physics deals with ontological questions. It is useless arguing that physics should be redefined. Physics is what it is. When mathematicians tells us that 2 + 2 = 4, we don't insist that they tell us 2 of what?, 4 of what? It doesn't matter. This is how the numbers behave. To dig deeper means moving to a metaphysics or mysticism forum. Still, I don't see why we shouldn't discuss how ontology and physics might be brought into line with each other. A theory that worked for both areas of research would be useful.
imatfaal Posted January 6, 2012 Posted January 6, 2012 In its defence, I would not see Owl's view as an endorsement of philosophy of science but as a rather odd view of it. I understand his frustration with the refusal of physics not to address ontological questions, or at least to treat them as important, but it is their right and a part of their method. This is how physics is defined, how it's done, what stops it being cluttered up with troublesome metaphysical issues. Metaphysics does not build power stations. The term 'fundamental physics' means 'as fundamental as physics gets', and shouldn't mislead us into thinking that physics deals with ontological questions. It is useless arguing that physics should be redefined. Physics is what it is. When mathematicians tells us that 2 + 2 = 4, we don't insist that they tell us 2 of what?, 4 of what? It doesn't matter. This is how the numbers behave. To dig deeper means moving to a metaphysics or mysticism forum. Still, I don't see why we shouldn't discuss how ontology and physics might be brought into line with each other. A theory that worked for both areas of research would be useful. I think 19 pages of this thread bear testament to the above (unintentional) double negative
owl Posted January 6, 2012 Author Posted January 6, 2012 (edited) In its defence, I would not see Owl's view as an endorsement of philosophy of science but as a rather odd view of it. ... When mathematicians tells us that 2 + 2 = 4, we don't insist that they tell us 2 of what?, 4 of what? It doesn't matter. This is how the numbers behave. To dig deeper means moving to a metaphysics or mysticism forum. Still, I don't see why we shouldn't discuss how ontology and physics might be brought into line with each other. A theory that worked for both areas of research would be useful. When non-Euclidean based physics and cosmology tells us that space has more than three dimensions, should ontology not ask to what a fourth axis/dimension refers... or seven more “dimensions” even after 3-D plus time as per M-theory? Do you think that it is irrelevant that math needs to refer to elements (in the broadest sense, referents) of the real world? Do you too think that the question, "What is spacetime, that 'it' is curved by mass?"... is irrelevant to science and to theories of gravity specifically? Do you think that SR theory and its math establishes that reality depends on frames of reference?... That the distances between stars varies with the frame of reference from which they are observed? And how about the old “shape of Earth” issue? Are the length contraction theory based descriptions (very oblate, etc.) equally valid with the well confirmed Earth science descriptions? Does “for a muon” count equally with atmospheric science in describing the distance through our atmosphere? Just a few philosophical questions to consider. But a clock detects oscillations, which you have agreed are things. So you are applying this definition inconsistently. Why is counting oscillations not a measurement of the number of oscillations? Do you see any difference at all between my meters (and what they detect and measure 'in the world') and clocks as self-contained ticking instruments. Their oscillations are built in and the clock is designed to count them. Do they create time and then measure it? Is time then on an equal ontological status (and existing entity) with the forces and photons which my meters measure? If you don't see any difference, there is no use trying to explain the ontology of time any further. The clocks used by the official timekeepers around the world adjust their clock outputs to keep them in the same frame; clocks are adjusted for their height above the geoid, and time transfer is adjusted for rotation effects. "Day" is a poor unit of measurement as it turns out, because the duration of a day is variable as compared to the duration of other phenomena, owing to rotation and orbital effects. That's one reason we define the length of the second. Days, however, generally aren't exactly 86400 seconds long — the earth is a poor clock. (from a scientific perspective) I understand the "adjusted output" concept. Same for GPS clocks. I still think that a time standard based on a master clock at sea level on the Equator and aligned with a distant star to mark 'one full rotation' would be an improved time reference for "a day" over the variety of present "clocked times" for a rotation, each requiring "adjustment." Aside from such fine points of adjustment, do you think that an Earth orbit (say an average over many years) is a good referent for "a year" when we say that Alpha Centauri is 4.3 light years away? Or can a year vary as much as my (above) ship's clock says and "make" A.C. a lot closer than that... and "elapsed time" to get there much shorter than 4.3 years... quite a lot faster than light? (Re my time travel question): Relativity narrows the possibilities, but does not yet completely rule it out. So relativity says that time might be 'something' we could travel through, and you endorse that possibility? Yet you claim that you don't reify time? Now, a non-sequitur of my own: do you own a watch or clock of any sort? Yes. Here comes another game, one little piece at a time! Why don't you just ask, "If you own a clock"... whatever. No "my time is not universal time" (a misnomer) if that is where you are going. I disagree with the premise. It is not science's job to discern the "true shape of the earth". Realism is not a premise of science. And we discover evidence indicating that it is not true. Science's job is to discover the true behavior of nature, and realism is not how nature behaves. If one's approach is that science's job is to determine reality, then the reality is that some parameters that science measures are invariant and some are not; realism is false. (So is idealism) It's a good thing you don't claim expertise in philosophy of science. We would still believe that the Sun revolved around Earth if it were not 'science's job' to figure out the "reality" that it is the other way around! Same for the "flat Earth." Turns out it's nearly spherical, according to all scientific measurements taken so far... science doing its job!) These were science's answers to the questions, "What shape is Earth, 'really', and what revolves around what, 'really'?" Then there is, "How far to the Sun, 'really'? Does it vary with how it is observed? ("Length is Not Invariant", repeat...) Realism says no and idealism says yes. Realists say cosmos has intrinsic reality. Idealists say it all depends on frame of reference. The difference is important. Imagine there is an intelligent being, moving very fast toward us. He has a clock that uses the same standard as ours — the duration of a second. He measures how long an earth rotation takes, and comes up with some number, significantly different from 86400. That has no effect on what people on earth say it is or experience. The exact same thing will happen if the intelligent being is at rest and the earth is moving toward him at high speed. You missed the part (earlier) about "What if there were no clocks?" Everything would still move as it does in the natural cosmos, and we can say that time elapses as things move, even without clocks "clocking" those movements at different rates. (More inscrutable philosophy.) Did you read my recent post on the relativity of velocity... all the way out to cosmic expansion 'relative to what'? How would "the whole thing" (cosmos and our little part of it) look to a comic intelligence? (Not that I am a theist.) We need to define our scope to make sense in science. For Earthlings, a year is one Earth orbit (standardized as best we can.) A year is not defined by the clocks on a fast spaceship. (More philosophical perspective.) It depends on the frame of reference. To those on the ship, the duration of the event will be less than 4.3 years. To an observer on earth, the event duration is more than 4.3 years.Where did I mention distance? You asked how long the trip took and assured me that you would use my answer to show reification. I saw later (but didn't edit) that I had used the reciprocal of time dilation, length contraction, in my answer... If time "expands" distance traveled "contracts." Not a huge leap, but you are correct. The obvious point was that the ship's clock will have shown way less than 4.3 years passing. Clocks slowing down is what "passes for" time slowing down, so, therefore, "for the crew" they effectively traveled way faster than light and the distance traveled was way shorter than the well know (in astronomy anyway) 4.3 light years. Probably more than enough on that! Or, perhaps, it's a matter of language, and there is the possibility that figurative language is being used that you are taking literally. "Space" is used in math to describe a system with an associated set of rules; a function space. "Minkowski space", for example, or "Hilbert space". A function space can have an infinite number of dimensions, and you're the only one in the room that thinks that you have reified anything by calling it a space. It is more than language. The most popular cosmology of the Big Bang, for instance, claims that "space expanded" faster than light during the "early inflation period" of the cosmos. M-theory has 11 dimensions of space. It's metaphysics based on the magic of math, but it has no meaning or possibility of falsification/verification. Yet it parades around as science. Study some ontology of space as relevant to cosmology. But you just got done implying that reifying space is bad. So if space is not a thing, how can there be any properties of space that can be measured? How can length be real? See my last sentence above. Real things exist in empty volume ...space. (Not empty where occupied, obviously.) Between these things is length or distance, as recently defined and discussed, which I will not repeat yet again. We "measure" cosmic distances in light years. Light speed is constant, so, in the real cosmos, the real distance to our nearest neighbor star is 4.3 lightyears. It would not become closer if a fast ship traveled to it... as beat to death above. "For the ship's crew" does not define the actual distance, in spite of your belief that there is no such thing as actual distance. ("Length is Not Invariant.") Time dilation, length contraction and curved spacetime ARE relativity. Right. It's all in the math. No ontology of what they are in "the real world" required. No "true shapes of cosmic bodies" or actual distances between them. And maybe time is a "timescape" after all, and we can travel back to the Bang and get the real scoop on it, and forward to see if it all runs down (entropy) or turns around and comes back. Great for science fiction, but it still ain't science. It's not a force, and nobody has claimed it is a force. That's a huge point. From the perspective of relativity, it's not a mechanical effect like friction is. If you deny time dilation, then it is you who is requiring that there be a force. I'm asking what it is. If you can't provide it than this is worthless, scientifically, and so the ontology adds no value to science. I'll have some respect for philosophy of science when you can demonstrate that it has added anything to the goal of science: knowing how nature behaves. "No, that's wrong" doesn't add to understanding. I should not have used the term “force.” Since nobody knows why clocks slow down with increased velocity and gravity, honest science should acknowledge that it remains a mystery and not say that “relativity” causes it. Like “spacetime” remains just a “whatever” with alternative theories of gravity, like “gravitons.” "Relativity makes it happen" is still not an answer. Learn some science and respect for what it has achieved. I've mentioned this quite a few times before. I have studied science all my life since I was old enough to be curious about the world/cosmos, and I am an old codger. I have taught philosophy of science with a focus on how reason and logic and the ontology of what things are and what key words mean all still applies. Your misrepresentation of me does not make it true. Edited January 6, 2012 by owl
PeterJ Posted January 6, 2012 Posted January 6, 2012 When non-Euclidean based physics and cosmology tells us that space has more than three dimensions, should ontology not ask to what a fourth axis/dimension refers... or seven more “dimensions” even after 3-D plus time as per M-theory? Of course, This is what ontology is for. Do you think that it is irrelevant that math needs to refer to elements (in the broadest sense, referents) of the real world?Do you too think that the question, "What is spacetime, that 'it' is curved by mass?"... is irrelevant to science and to theories of gravity specifically? Not irrelevant, but not crucial. Crucial to me, and maybe to you, but that's just us.
swansont Posted January 6, 2012 Posted January 6, 2012 Do you see any difference at all between my meters (and what they detect and measure 'in the world') and clocks as self-contained ticking instruments. Their oscillations are built in and the clock is designed to count them. Do they create time and then measure it? Is time then on an equal ontological status (and existing entity) with the forces and photons which my meters measure? If you don't see any difference, there is no use trying to explain the ontology of time any further. Of course they don't create time. That would be silly. Time is not a substance. As for the other meters mentioned, the true ontological question is still a few layers deeper. But the topic of discussion here has been time and length, so the relevant comparison here is the meter stick. Doesn't a meter stick — a self-contained device — have a length, all by itself? So let's try this: clock are used for comparison. You compare the duration of an event to a clock. Is that a measurement? I understand the "adjusted output" concept. Same for GPS clocks. I still think that a time standard based on a master clock at sea level on the Equator and aligned with a distant star to mark 'one full rotation' would be an improved time reference for "a day" over the variety of present "clocked times" for a rotation, each requiring "adjustment." You would be wrong by many orders of magnitude in precision and accuracy. Even sundials use a correction for the "equation of time", e.g. the gnomon position being on an analemma. Aside from such fine points of adjustment, do you think that an Earth orbit (say an average over many years) is a good referent for "a year" when we say that Alpha Centauri is 4.3 light years away? Or can a year vary as much as my (above) ship's clock says and "make" A.C. a lot closer than that... and "elapsed time" to get there much shorter than 4.3 years... quite a lot faster than light? Probably accurate and precise enough. But the ship would not travel faster than light. And before you claim yet again that this doesn't happen, I know that you have not done the experiment, so you cannot state that you have evidence that it does. But we do observe the effects of length contraction. And since I know you don't like the muon example, I'll use a different one: Magnetism. The magnetic force on a moving charge from a current in a conductor (such as is exploited in an ammeter) is a consequence of relativity. In the rest frame of the charge, there can be no magnetic force, yet a force exists. You must have length contraction in a moving frame to account for the existence of the force. details here in case anyone is interested http://physics.weber.edu/schroeder/mrr/MRRtalk.html (Re my time travel question): So relativity says that time might be 'something' we could travel through, and you endorse that possibility? Yet you claim that you don't reify time? "Travel through time" is a figurative description. One should take care not to take it literally, lest you think that time is a substance. Yes. Here comes another game, one little piece at a time! Why don't you just ask, "If you own a clock"... whatever. No "my time is not universal time" (a misnomer) if that is where you are going. You do find it useful, though. If you go to bake something, you want to know how long to leave it in the oven. You don't sit there and complain that time isn't real, and how a countdown display reifies time. It's a good thing you don't claim expertise in philosophy of science. We would still believe that the Sun revolved around Earth if it were not 'science's job' to figure out the "reality" that it is the other way around! Well, no that's a gross mischaracterization of what I said. I said it's science's job to find out how nature behaves, and before one can ask what the true shape of the earth is, one has to ask if the earth has a true shape. You have decided — based solely on ideology, which is not scientific — that the answer is yes. Same for the "flat Earth." Turns out it's nearly spherical, according to all scientific measurements taken so far... science doing its job!)These were science's answers to the questions, "What shape is Earth, 'really', and what revolves around what, 'really'?" Except it isn't. It's the answer to "what is the shape of the earth as measured by observers in the earth's frame of reference?" You have absolutely no evidence of the shape as measured from radically different frames, so you can't claim that knowledge. Then there is, "How far to the Sun, 'really'? Does it vary with how it is observed? ("Length is Not Invariant", repeat...) Realism says no and idealism says yes. Realism and idealism are philosophies, neither of which is a basis for science. Realists say cosmos has intrinsic reality. Idealists say it all depends on frame of reference. The difference is important. Don't forget the third category, that says neither extreme is true. You missed the part (earlier) about "What if there were no clocks?" Everything would still move as it does in the natural cosmos, and we can say that time elapses as things move, even without clocks "clocking" those movements at different rates. (More inscrutable philosophy.) Did you read my recent post on the relativity of velocity... all the way out to cosmic expansion 'relative to what'? How would "the whole thing" (cosmos and our little part of it) look to a comic intelligence? (Not that I am a theist.) We need to define our scope to make sense in science. For Earthlings, a year is one Earth orbit (standardized as best we can.) A year is not defined by the clocks on a fast spaceship. (More philosophical perspective.) Yes, you are correct, it's not defined that way. Nobody has claimed that it is. I saw later (but didn't edit) that I had used the reciprocal of time dilation, length contraction, in my answer... If time "expands" distance traveled "contracts." Not a huge leap, but you are correct. The obvious point was that the ship's clock will have shown way less than 4.3 years passing. Clocks slowing down is what "passes for" time slowing down, so, therefore, "for the crew" they effectively traveled way faster than light and the distance traveled was way shorter than the well know (in astronomy anyway) 4.3 light years. Nobody will have traveled faster than light. It is more than language. The most popular cosmology of the Big Bang, for instance, claims that "space expanded" faster than light during the "early inflation period" of the cosmos. Again: figurative vs literal. See my last sentence above. Real things exist in empty volume ...space. (Not empty where occupied, obviously.) Between these things is length or distance, as recently defined and discussed, which I will not repeat yet again. We "measure" cosmic distances in light years. Light speed is constant, so, in the real cosmos, the real distance to our nearest neighbor star is 4.3 lightyears. It would not become closer if a fast ship traveled to it... as beat to death above. "For the ship's crew" does not define the actual distance, in spite of your belief that there is no such thing as actual distance. ("Length is Not Invariant.") How can the space be empty if length — a real thing, according to you — is between them? If space is empty, it's empty. If length is real, then space is not empty, it is full of length. Does this length only pop into existence when there are objects in the space? Right. It's all in the math. No ontology of what they are in "the real world" required. No "true shapes of cosmic bodies" or actual distances between them. And maybe time is a "timescape" after all, and we can travel back to the Bang and get the real scoop on it, and forward to see if it all runs down (entropy) or turns around and comes back. Great for science fiction, but it still ain't science. Luckily for us, you don;t get to decide what is science. I should not have used the term “force.” Since nobody knows why clocks slow down with increased velocity and gravity, honest science should acknowledge that it remains a mystery and not say that “relativity” causes it. Like “spacetime” remains just a “whatever” with alternative theories of gravity, like “gravitons.” "Relativity makes it happen" is still not an answer. Regardless of how palatable you find it, it is an answer. Relativity may be a mystery to you, but it is not a mystery to all. I've mentioned this quite a few times before. I have studied science all my life since I was old enough to be curious about the world/cosmos, and I am an old codger. I have taught philosophy of science with a focus on how reason and logic and the ontology of what things are and what key words mean all still applies. Your misrepresentation of me does not make it true. It's how you represent yourself. You are being offered an opportunity to get out of the 19th century (plus a few years)* and thus far you have refused it. Actually, that's probably not even right. That's only the era when absolute time was accepted. Time has been measured for far longer than that.
md65536 Posted January 6, 2012 Posted January 6, 2012 I've mentioned this quite a few times before. I have studied science all my life since I was old enough to be curious about the world/cosmos, and I am an old codger. I have taught philosophy of science with a focus on how reason and logic and the ontology of what things are and what key words mean all still applies. Your misrepresentation of me does not make it true. How about my misrepresentation of you, is it true?: You have acquired your information via gnosis. This is more powerful and convincing than any scientific logic or mathematical argument. What others don't realize is that unless they can evoke a sense of gnosis in you, what you already "know" is truer than anything they can "prove" using reasoning or evidence, which is a "tedious" waste of time. You're not interested in discussing questions of philosophy of science, because you already have the answers. You're here to preach them. If required I can try to back up these statements with evidence. At your request I will refuse to disclose evidence on the grounds that it may identify you.
owl Posted January 7, 2012 Author Posted January 7, 2012 (edited) A quick reply, just passing by. More later maybe before the weekend. swansont: "Travel through time" is a figurative description. One should take care not to take it literally, lest you think that time is a substance. What might ‘it’ be if “time reversal” or some kind of "fast forward" were possible, "going back to the past" or "into the future?" The word “travel” has acquired a meaning... like from here to there or "from the present to the future or past." How about an honest conversation about what “time” must be to “travel” to the past or future? "A substance?" Like some idiot might believe? Seriously, what do you travel through if you travel through time? A simple question. How about a simple answer? Or is it all about math, and I simply don't speak the language? An obvious smoke screen... quite transparent. swansont: Well, no that's a gross mischaracterization of what I said. I said it's science's job to find out how nature behaves, and before one can ask what the true shape of the earth is, one has to ask if the earth has a true shape. You have decided — based solely on ideology, which is not scientific — that the answer is yes. Most of science ( besides length contraction advocates) already knows Earth’s “true shape.” OK. Short of taking a forum poll, which I don’t know how to do, even if it were an option... How many here think that Earth has a “true shape?” “True” here means intrinsic or objective or independent of frame of reference from which it is measured. I will continue after folks here place their votes. Edited January 7, 2012 by owl
tar Posted January 7, 2012 Posted January 7, 2012 Just wondering. When the flyby guy is traveling at 99 percent the speed of light. Whose measurements are we using to determine this speed? Whose second are we using? Whose meter are we using? If the seconds and meters can vary but C can not, what is it exactly that is invariant? C is the distance that light travels in a certain period of time. Whose distance? Whose time? Just wondering. And the traveling twin. Why does she return younger? The stay at home was the one that was traveling at near light speed, relative to her. The stay at home should have been younger than her upon her return. ? Just wondering. If the equations work in the one direction, they should work in the other. Calling each frame a rest frame in turn. Why don't all the effects cancel out, and she should return exactly the same age as her twin? Just wondering.
owl Posted January 7, 2012 Author Posted January 7, 2012 (edited) Just wondering. When the flyby guy is traveling at 99 percent the speed of light. Whose measurements are we using to determine this speed? Whose second are we using? Whose meter are we using? If the seconds and meters can vary but C can not, what is it exactly that is invariant? C is the distance that light travels in a certain period of time. Whose distance? Whose time? Just wondering. And the traveling twin. Why does she return younger? The stay at home was the one that was traveling at near light speed, relative to her. The stay at home should have been younger than her upon her return. ? Just wondering. If the equations work in the one direction, they should work in the other. Calling each frame a rest frame in turn. Why don't all the effects cancel out, and she should return exactly the same age as her twin? Just wondering. Very good questions. I'll be waiting with you for the way the answers are dodged. (Don't expect direct answers.) Although I didn't 'stamp' my last post 'properly', I'll be waiting for answers also to my question to the forum... Who thinks the Earth has a 'true shape' (intrinsic, etc) and who thinks it depends on how we look at it? Just looking to see if anyone here besides me is a lurking realist. My answer to your question is that moving faster relative to a stay-at-home twin will slow down the aging process for the traveler. She will not "get younger" as in reversing the aging process, but just age more slowly. So she will come back "younger" than her twin. Just my guess based on clocks slowing down in orbit, etc. compared to identical clocks on the surface, not having been accelerated to higher velocity. Ps: Readers of this thread will have noticed that someone (a long time stalker through a few forums, one with with a malicious personal agenda against me... not overstated!) seems to be 'threatening' me with exposure of my spiritual/ mystic interests, which I have never brought to this forum. Not appropriate. Neither are my many other interests outside of science. I would be more direct, but I meant it when I said that I would not reply (directly) to any more of his/her always- personally-attacking posts. Edited January 7, 2012 by owl
md65536 Posted January 7, 2012 Posted January 7, 2012 (edited) Ps: Readers of this thread will have noticed that someone (a long time stalker through a few forums, one with with a malicious personal agenda against me... not overstated!) seems to be 'threatening' me with exposure of my spiritual/ mystic interests, which I have never brought to this forum. Not appropriate. Neither are my many other interests outside of science. I would be more direct, but I meant it when I said that I would not reply (directly) to any more of his/her always- personally-attacking posts. I've told you before, I've never known you on any other forums. Please stop telling lies about me. I've only fact-checked information you've posted on this forum. It wasn't a threat, it was an offer. Which you appear to have passed on. You're constantly providing character evidence in favor of yourself, so I think it's only fair that the other side is given. But if no one cares I won't even bother. I don't want to tarnish your reputation just out of spite. My personal agenda isn't against you, it's against your personal agenda. You know what? I think I should just bury the hatchet right here. Something you said (not here) reminds me of a quote from Twin Peaks: Albert Rosenfield: [to Sheriff Truman] Now you listen to me. While I will admit to a certain cynicism, the fact is that I am a naysayer and hatchetman in the fight against violence. I pride myself in taking a punch and I'll gladly take another because I choose to live my life in the company of Gandhi and King. My concerns are global. I reject absolutely revenge, aggression, and retaliation. The foundation of such a method... is love. I love you Sheriff Truman. This was after some unfriendly tension and maybe a couple punches to faces (Albert was not well-received because of his abrasiveness and lack of social etiquette). After this turning point they were best buds, and Albert turns out to be a pretty good guy. The fact is, people seem to enjoy these scholarly debates with you. They're obviously getting something out of it. I won't ruin the fun. I still disagree with you and what you're doing and I think you should stop. But I don't think I care enough to have a personal agenda, especially if people willingly engage you in debate. I think they can decide for themselves if there's a point to it. Ignoring me was working pretty well. Not a big fan of the whole responding to my post to everyone else while making a point of how you're ignoring me though. Edited January 7, 2012 by md65536 1
Iggy Posted January 7, 2012 Posted January 7, 2012 Just wondering. When the flyby guy is traveling at 99 percent the speed of light. Whose measurements are we using to determine this speed? Whose second are we using? Whose meter are we using? Either. If I, for example, recede away from you at 0.99c (our relative speed is .99c) then every second you will find (using your ruler) that I get 296,794,533 meters further away. I would find (using mine) the same about you -- your velocity away from me is 296,794,533 meters per second. If the seconds and meters can vary but C can not, what is it exactly that is invariant? C is the distance that light travels in a certain period of time. Whose distance? Whose time? Just wondering. This post explains. All inertial observers (non-accelerating observers) should measure the speed of light at c. In other words, anyone traveling at a constant velocity should measure light to travel one lightyear per year (or whichever units you like) with their own clock and ruler. For example, imagine you are here on earth measuring the speed of light rays that go from the sun to the earth. With your ruler the distance to the sun is 8.3 light-minutes. With your clock it takes light 8.3 minutes to go from the sun to the earth. The speed of light, you will find, is 8.3 light-minutes divided by 8.3 minutes, or 1c. If I, on the other hand, am approaching the sun at .6c in a spaceship (my velocity relative to it is .6c) I would measure the distance between the sun and earth as 6.64 light-minutes with my ruler. This is shorter than you found because of length contraction. From the rocket I would measure the time it takes light to travel the distance at 6.64 minutes. This is again shorter than your time because of time dilation. I would calculate the speed of light as 6.64/6.64=1c. It is because of length contraction and time dilation that c is invariant. And the traveling twin. Why does she return younger? The stay at home was the one that was traveling at near light speed, relative to her. The stay at home should have been younger than her upon her return. The short answer is that the homebody didn't change reference frames so the thought experiment isn't symmetrical. Because of the relativity of simultaneity this makes a big difference. If the equations work in the one direction, they should work in the other. Calling each frame a rest frame in turn. Why don't all the effects cancel out, and she should return exactly the same age as her twin? If both twins accelerated away from each other, then toward each other, equally then they would cancel out. Just wondering. Have you tried reading any online publications on relativity? I think you might enjoy, for example, Special Relativity
PeterJ Posted January 7, 2012 Posted January 7, 2012 (edited) And the traveling twin. Why does she return younger? The stay at home was the one that was traveling at near light speed, relative to her. The stay at home should have been younger than her upon her return. Just wondering. If the equations work in the one direction, they should work in the other. Calling each frame a rest frame in turn. Why don't all the effects cancel out, and she should return exactly the same age as her twin? Just wondering. This is well explained in Cox and Forshaw's recent book 'Why Does E=MC2'. It's a good read, and addresses most of the issues being discussed here. Edited January 7, 2012 by PeterJ
tar Posted January 7, 2012 Posted January 7, 2012 Iggy, Yes I have tried. Probably not hard enough. I suppose my problem is finding something to hold constant. I try the measured at C thing and it makes sense, and "works out", until I try and comprehend the consequences. I for instance want to flip back and forth between the frames and see the thing that is constant. I have understood the grids and the math, and to a certain extent, the "spacetime" that is referred to. But I have Owl's problem, in wanting to match up the numbers with real stuff. So that I can understand the consequences. If there is "something" on which the real world is based, I would like to understand it. I do not seek however to prove length contraction and time dilation incorrect, as Owl seems to be insisting. I on the other hand, have the same "realist" intuition, but am completely open to learning what is "meant" by the terms. That is what is convention, what is analogy and metaphor, and what are the "real" referents we are referring to. For instance, if there is not "something" for the stay at home to remain in, and everything is completely relative. Then to the traveling twin, who never changed reference frames either, it was indeed the Earth that sped away, and came back to her. The kind of thing I am suggesting is a matrix of gravitational and magnetic fields that one can actually be moving through, or staying stationary to. Certain of it moves along with you, and certain of it, you are moving through. The matrix itself is not "fixed" in position, except by reference to all of it, from any one here and now. Since the fields generated by Alpha Centuri and the Sun express themselves at C, and have been doing so, for much longer than 4.3 years, the Alpha Centuri-Earth part of the matrix is already here. In fact a whole bunch of local stars are locked together already, in a swirl around the center of the Milky Way. It makes a difference, in my imagination, whose fields you are moving in reference to. And whose fields you are moving along with. Complicated to figure, and maybe this is what the equations of relativity are meant to address. But it seems required that the traveler is moving through "something" that the Earth is moving along with, for there to be a difference in the ages of the twins upon the return of the traveller. Regards, TAR2 even dark matter and energy should have some behavioral characteristics neutrinos should be standing still or swirling about, or coming in, or going out from or to or in or out or around "something" shouldn't they? PeterJ, Yeah, I should probably do a bit less wondering and a lot more reading. Regards, TAR2 I wonder why I don't
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