What is time?

[watcher]

The question then would be: why does a clock in the nose of a rocket run fast? Why do two events (two flashes of light, let's say) take more time as judged by the nose of an accelerating rocket than they do as judged by the aft?

 

how about doppler effect?

spaceship AFT - ) ) ) ) ) -------> ))))) - spaceship nose

 

the nose due to acceleration is more distorted than the aft.

[lawcat]

Actually it is a real effect, i.e., time dilation is not "a way of correcting our perception of time in another locality."

 

The time dilation in the example above is real, not just apparent (as you seem to imply).

 

 

Coldcreation,

 

Thanks. But the problem that modest set forth was about a rocket on which both the nose and the aft move at the same rate, but there is some shifting due to acceleration I suppose.

A different scenario is when observer and the object move at different velocities. Then, I agree, time dilation is not just a correction.

Then, as you suggest there is a problem of two object moving at same velocity but in different gravitational fields.

 

In any case, my understanding is that there has to be a difference in velocity or path (gravitation) for time dilation to take effect.

[coldcreation]

Coldcreation,

 

Thanks. But the problem that modest set forth was about a rocket on which both the nose and the aft move at the same rate, but there is some shifting due to acceleration I suppose.

A different scenario is when observer and the object move at different velocities. Then, I agree, time dilation is not just a correction.

[...]

In any case, my understanding is that there has to be a difference in velocity or path (gravitation) for time dilation to take effect.

 

I think the problem stems from the concept of acceleration. Modest will correct me if I am mistaken. If the rocket is accelerating then the rate of motion is not constant at the nose and tail of the rocket. Had the rocket been traveling in a straight line, unaccelerated, at a constant velocity, and in the absence of a gravitational field, then there would be no time dilation difference between the front and back of the ship.

 

In other words, the acceleration makes the situation equivalent to the scenario where the rocket is at rest in a gravity field. The top of the rocket is at a higher elevation in the field than the aft. See Einstein elevator thought experiment linked above.

 

So redshift and time dilation will occur when a test is performed (of the Pound–Rebka type) inside the rocket; when at rest in a gravity field and/or during acceleration.

 

 

CC

[modest]

Coldcreation,

 

Thanks. But the problem that modest set forth was about a rocket on which both the nose and the aft move at the same rate, but there is some shifting due to acceleration I suppose.

A different scenario is when observer and the object move at different velocities. Then, I agree, time dilation is not just a correction.

Then, as you suggest there is a problem of two object moving at same velocity but in different gravitational fields.

 

I agree with CC. You certainly shouldn't see gravitational time dilation or time dilation in an accelerating frame as any less real than velocity time dilation. The clocks in the thought experiment would surely show a difference if they are brought together on the ship. You can think, for example, if a person stands next to you and appears the same size as you he will look smaller (appear smaller) if he walks away from you. This is just perspective, just an appearance or 'distortion'. As the person returns to you he will again appear the same size.

 

In a different vein, two clocks in the nose of an accelerating ship would run at the same rate. If you took one to aft and let it run for a while then returned it to the nose they would no longer agree. The slowing of the clock was real in the sense that it really did tick less times.

 

In any case, my understanding is that there has to be a difference in velocity or path (gravitation) for time dilation to take effect.

 

The path thing you've mentioned with respect to gravity is probably a reference to a principle in general relativity called the principle of extremal aging. It indicates that the longest amount of time possible between two events is the inertial or 'free' path between them. The twin paradox would be an example. Between the two events the home twin ages a lot while the accelerating twin ages very little. The maximum amount of time between the two events (the departure and the reunion are the two events) is the path without all the accelerating. But, this doesn't really tell us why they age differently. And, it does not indicate, as some have taken it recently, that inertial forces are the cause of time dilation.

 

 

I think you might be on to something with the clocks each going a different velocity, like CC says. Certainly the clocks in the rocket act like the have a different relative velocity. :)

 

~modest

[CraigD]

Try as you will to fix me, I still ain't broken.

“Broken” is a provocative and pejorative thing to call a person, or their worldview. Nonetheless, as you continue with your present line of assertion and denial, Michael, with statements such as

Clocks "tick" faster or slower at different altitudes, certainly, but the last assertion is absurd. Likewise the assertion that the "duration of one earth orbit" takes more or less time depending on velocity of point of observation. This simply is not true.

, practically everyone with a modicum of modern physics education is likely to see it as evidence of a gaping hole in your perception of objective physical reality, blinding you to one of the most profound richnesses in the history of scientific ideas: special relativity. Your hope that your critics will understand and accept your worldview as it concerns relativity (a hope which I assume you, as a good-faith discussion participant, actually have) is, I think, misplaced, as we already understand it with the intimacy of having held it prior to having studied relativity, rejecting it in favor of this theory’s simple and compelling logic.

At this point I will take continued ignore-ance of the above challenges as an admission that subjective idealism rules in this forum...

I think it’s epistemologically inaccurate to say that subjective idealism rules hypography, or scientific thought in general.

 

With the exception of some interpretations of quantum mechanics (a theory not much relevant to the immediate discussion – please don’t proceed far down this branch) especially popular in the 1970s and 80s (see, for example, The Dancing Wu Li Masters), “orthodox” scientific thought, which could also be termed following the scientific method, practically requires objective idealism’s acceptance of a single objective reality in order to form theories. It then requires acceptance of subjective idealism’s “that which cannot be perceived doesn’t exist” to make testable predictions, and test them via experiments.

... and it implies the obvious absurdities cited in my challenges above.

Live with it (said absurdity) or answer for it.

As we humans require various innate and acquired cognitive traits to simply navigate and survive the everyday world – what developmental psychologists such as Piaget call schemata – and these traits also allow us to label ideas absurdities, science students must, to some extent, live with a host of “obvious absurdities” arising from conflicts between these intuitive cognitive traits and formal scientific ideas. Fortunately, we appear to also have an effective collection of cognitive traits – what cognitive psychologists such as Lakoff call conceptual metaphor – that allow us to live easily with absurdities of many kind, many much more pedestrian than those arising from differences between our intuitive feel for physical reality and the predictions of relativity.

 

With the above, and a goal of fixing your (in my view) flawed worldview in mind, Michael, I’d like to narrow my discussion to a simple, slightly altered version of a key thought experiment from the literature of special relativity: the light clock (The wikipedia section “Simple inference of time dilation due to relative velocity” gives a brief illustration and explanation of this).

 

Let’s assume your assertion that

the assertion that the "duration of one earth orbit" takes more or less time depending on velocity of point of observation ... [is] simply is not true.

is true. Via intuitive, informal geometry agreeing with our common-sense perceptual schemata, I intend to show that we must as a consequence of this assumption conclude that the speed of EM (light) signals, such as radio, must sometimes significantly exceed 299792458 m/s (a constant known as “c”).

 

Let’s assume that a radio operator, for reasons with which we won’t concern ourselves, sends a brief radio signal between computer operated transceivers in Chicago US and London UK. It takes the radio signal, traveling a reflecting path through various layers of atmosphere, about 0.0215 seconds to make the trip one way. Upon receiving the signal, each transceiver transmits an identical reply, after a delay of almost exactly 0.001 s required by its electronics and software. Each year, the computer counts about 1920000 round trip signals, and the radio signals travel a total of about 0.956 lightyears.

 

Let’s assume someone many light years away is watching all this with a very powerful (far more powerful than any we have not) telescope, and that they measure the Sun and Earth to be traveling at about 0.8 c. We’re assuming that he sees the same events occur – the computer counting 1920000 round trip radio signals, the Earth revolving around the Sun one time in one year. However, because he sees the radio signal not only traveling back and forth between Chicago and London at 1 c, but through space at 0.8 c, he sees the signal moving at about 1.28 c.

 

There’s nothing logically inconsistent or counterintuitive about this. It simply doesn’t assume the “Principle of Invariant Light Speed” postulate of Special Relativity. There’s nothing a-priori, ontologically or epistemologically absurd about not assuming this postulate.

 

There is, however, something non-scientific about it. Science requires that what we assume to occur is supported by experiments showing it to actually occur. Even though it’s not intuitively sensible (other than to physics students, who have arguable skewed their intuition from what it would be had they not studied modern physics), no experiment measuring the speed of a EM signal has shown it to travel faster than 299792458 m/s, or, except in mediums with high refractive indexes (eg: water, glass, or diamond), much slower.

 

This is the counterintuitive absurdity with which late 19th century physicists found themselves confronted. Much in the way that heliocentrism initially confounded intuitive sensibilities, but eventually illuminated scientific thought, this counterintuitive result triggered the modern physics revolution (AKA “the second scientific revolution”) of which Einsteinian Relativity is a central theory.

[Michael Mooney]

To whom it may concern...

(primarily addressed to CraigD, freeztar, Modest, and Watcher, most recently):

 

Believe it or not ("not" clearly applies for all listed above, and many others here), I have understood both general and special relativity for many years now, tho most of you keep repeating those actual experimental results and thought experiments which illustrate the combined body of observed information called, collectively, the theory of relativity.

 

I have repeatedly asked this forum to consider the possibility that human perspective, including "who can see what and when, as dictated by lightspeed" and what our "clocks" in the broadest sense tell us about the duration of natural motion/cycles... is not the whole picture of the cosmos, as it is, independent of the limits of human observation.

 

One of my favorite challenges in this regard has been my "thought experiments" asking folks to imagine that either there are no humans or there are no clocks... or both. The object of contemplation then becomes, the cosmos as it is (notice the present tense), overall or on solar system scale, independent of the limit of lightspeed for visibility (what we can see, delayed as it is by lightspeed limit.)

The reason for this exercise is that, clearly, regardless of the variability of clocks' time-keeping ability under different circumstances, Earth must and does spin and orbit at a rate independent of our measures of its periods (clocking them with variable time-keepers,) as above.

 

And, regardless of our measurements of distance, under similar limits intrinsic to our measuring devices, the distance from sun to earth, moon to earth or sun to other planets does not, in actual fact, vary with whatever point of view ( nominally static or with a velocity, etc) from which such distances are measured. The differences are only *apparent* because of the above mentioned limits (of lightspeed, clock variability, etc.), not *actual* as would be seen from an *imagined* (thought experiment, remember) "frame of reference" (so called) without a local frame from which to observe!

Since no one here yet has engaged in this thought-experimental universal observational perspective (except Doctordick), everyone keeps hammering on local "frames of reference" as if that is the end all perspective for what can be known about the cosmos.

 

What is worse, most here actually believe that the earth's cycles actually do change pace according to what our clocks are telling us and that distances between bodies actually vary with the poor limits of human observation and its conveyance, light, with its inherent signal delay.

 

That I don't buy it irritates all of you to no end... but... that is not my problem.

Gotta go.

Michael

[modest]

A problem evident in the post above is in thinking of the duration between two events as some singular, disassociated thing. That is clearly not the case. The duration between two events does not exist in and of itself. It is always an expression of some path taken by a material point. The entire notion of duration is incomplete without reference to the path or the frame of reference in which it exists. You cannot disassociate the two and still have a meaningful concept.

 

Imagine if someone told you that if there were no people and no measurements then the velocity of objects would not change with the things that velocity is relative to. Haley's comet for example, if there were no people then its velocity would not change as relative to Mars, and relative to Venus, the Earth, the Sun, the Milky Way. No, that doesn't make sense because the concept of velocity is itself incomplete without a reference to something. A baseball thrown in an airplane has a velocity of 30 meters per second relative to the plane, and a velocity of 200 meters per second relative to the airport from which the plane took off.

 

Even if you find it intuitive that the baseball has a singular, disassociated velocity without respect to anything else, that does not make it so. Consider next something that is a function of velocity. Consider the kinetic energy of the baseball. What is its kinetic energy? That is an incomplete question. It has nothing to do with subjective idealism or human measurement. It is simply that the quantity "kinetic energy" is frame dependent. Although 'it' (kinetic energy) is certainly real, certainly a real phenomenon, it is meaningless as a concept without specifying to what the kinetic energy is relative. Relative to the ground it has 44 and four ninths as much kinetic energy as it does relative to the plane regardless.

 

If you've followed along and tried to make sense of the above rather than trying to think of a sensible sounding rebuttal while reading it, then it should follow deductively: the time between two events is a function of the path taken between them. Time is a function of velocity. It is frame dependent. What is the duration between two perihelion events of Haley's comet? It is an incomplete question. Is the time relative to the Sun, the Earth, or the comet itself?

 

Human intuition tells us that time is not a variable, but is absolute. If I experience a 45 seconds between mile markers on I35 the I expect an insect on the road also experienced 45 seconds during the time I traversed the two mile markers and the GPS clock in orbit also experienced 45 seconds during the transit. But, this intuition is wrong. The duration between event 1 and event 2 depends on the path taken between those events.

 

It is not that the duration of an earth orbit is an entity which gets changed every time a clock somewhere in the universe changes velocity. On the contrary, the very concept of duration itself is meaningless without something to which the duration is relative. Saying "one earth orbit takes X amount of time" is elliptical for saying "one earth orbit takes X amount of time with respect to Y".

 

I'm afraid this is so fundamental to relativity that if you cannot understand it, you cannot understand what this thing is that everybody keeps talking about: relativity.

 

~modest

[watcher]

Believe it or not ("not" clearly applies for all listed above, and many others here), I have understood both general and special relativity for many years now, tho most of you keep repeating those actual experimental results and thought experiments which illustrate the combined body of observed information called, collectively, the theory of relativity.

 

actual experiments strongly implied this is the phenomenal world we humans live and function.

 

I have repeatedly asked this forum to consider the possibility that human perspective, including "who can see what and when, as dictated by lightspeed" and what our "clocks" in the broadest sense tell us about the duration of natural motion/cycles... is not the whole picture of the cosmos, as it is, independent of the limits of human observation.

 

einstein would be happy enough if you just tell him what an electron is. let alone the whole picture of the cosmos.

 

to see the whole picture independent of human perspective reminds me of godel's incompleteness theorem, as i understand it, it can mean that the part of the system cannot fully comprehend the whole system.

 

One of my favorite challenges in this regard has been my "thought experiments" asking folks to imagine that either there are no humans or there are no clocks... or both. The object of contemplation then becomes, the cosmos as it is (notice the present tense), overall or on solar system scale, independent of the limit of lightspeed for visibility (what we can see, delayed as it is by lightspeed limit.)

The reason for this exercise is that, clearly, regardless of the variability of clocks' time-keeping ability under different circumstances,

 

be that as it may referring to my godel thing, i would try the thought experiment.

 

i imagine (the uncomplicated version) the cosmos as an expanding balloon. the spherical surface area would be space and the outward expansion of the balloon would be the direction of time. c is the velocity of the outward expansion and the concurrent speed limit. inside the balloon was the past and the outside of the balloon is the potential future. the present is where the surface of the balloon intersect with the direction of time. notice that the present is also constantly changing as the balloon expands outward in time. again notice that the perspective i took to see the whole picture is also outside of the present moment. i am outside because i am looking at the present and defining it as a dynamic part of the whole picture/system.

 

and oh from where i am looking naturally there is no time, as i am also outside of time, space too. can you grok that?

 

Earth must and does spin and orbit at a rate independent of our measures of its periods (clocking them with variable time-keepers,) as above.

 

as above my thought experiment. i see that nothing is independent of anything, you are correct that spin orbit is independent of our time keeping, but simply because its the other way around... our time keeping is purely dependent from earth spin or orbit and now dependent of electron's spin and orbit as we began to be more sophisticated in our time keeping devices, (clock)

 

so the question is where does electron spin and orbit dependent upon?

if we can know where orbital motion depends, then we wiil know why time dilates. ie, the orbital motion slows down.

 

And, regardless of our measurements of distance, under similar limits intrinsic to our measuring devices, the distance from sun to earth, moon to earth or sun to other planets does not, in actual fact, vary with whatever point of view ( nominally static or with a velocity, etc) from which such distances are measured. The differences are only *apparent* because of the above mentioned limits (of lightspeed, clock variability, etc.), not *actual* as would be seen from an *imagined* (thought experiment, remember) "frame of reference" (so called) without a local frame from which to observe!

 

they (the differences or discrepancies) are not apparent. they are real caused by the scalar nature of light speed. you admitted already that they were the results of experiments. so they are not purely based of human perceptions, instead these phenomena are how the limited human perception "see" the cosmos. there is a huge difference my friend.

 

finally, i am not discounting you own thought experiment, i think that you have taken the perspective of the entire space that contains everything. in my analogy, that would be the spherical surface area of the balloon, from that perspective, yes there is nothing but the present. the arrow of time was out of the picture, thus there is no expansion and yes you can see that all the objects in the universe have their fixed position. but notice that without time, the whole picture is not dynamic but only a snap shot of the cosmos

[CraigD]

One of my favorite challenges in this regard has been my "thought experiments" asking folks to imagine that either there are no humans or there are no clocks... or both.

I’ve difficulty imagining this, because as I define a “clock” (for example, in “Implications of the most inclusive possible definition of ‘clock’”), any universe with two or more bodies capable of interacting cannot have no clocks.

 

Imagining no humans is easy, as I’m barely capable of imagining, in a rigorous way, a universe containing objects even as complicated as molecules of atoms capable of the orderly storing of information. I’m only able to imaging anything as complicated as an animal with even vaguely human characteristics by employing, unconsciously (and thus without rigor), many layers of perceptual metaphor – something I find fun, but don’t much trust.

The reason for this exercise is that, clearly, regardless of the variability of clocks' time-keeping ability under different circumstances, Earth must and does spin and orbit at a rate independent of our measures of its periods (clocking them with variable time-keepers,) as above.

These statements puzzle me, because the rotation and revolution of the Earth are clearly to me both very venerable clocks – and, until historically recently, sufficiently unvarying and precise for most human purposes (the length of year tends to increase by about one second every 800,000 years, the day by about 1 s every 44,000 years, while both vary chaotically in a continuous way). In short, the Earth and the Solar system are good, but no longer the best, available clocks. They are more variable, and less predictably variable, than some other useful time-measuring phenomena, less variable and more predictable than others, but special only because of their historic association with us Earthlings.

Believe it or not ("not" clearly applies for all listed above, and many others here), I have understood both general and special relativity for many years now, tho most of you keep repeating those actual experimental results and thought experiments which illustrate the combined body of observed information called, collectively, the theory of relativity.

My apologies if I’m mistaken, but I’ve not seen a demonstration by you, Michael, in these forums or some other writing or discussion, of the sort of understanding of relativity I’d expect from someone completing an undergraduate college class in modern physics, while you’ve made many statements I’ve seen made by students prior to, but not after, completing such classes. I must admit to a belief like that expressed in Snow’s The Two Cultures, that people who can’t perform at least rudimentary, formal calculations of modern physics can’t, in a practical, meaningful sense, understand them. In much the way I’m skeptical of someone who tells me “I know how to juggle” until I’ve actually seen them keep a few balls in the air, I’ll be skeptical of your claim of understanding both general and special relativity until I’ve seen you do some calculating tricks with them.

 

Without the ability to perform these “tricks”, and their prerequisite geometric, arithmetic, and algebraic tricks, I’m uncertain to what extent you’re able to comprehend dichotomies such as the one I tried to present in post #838, Michael. If you do, I would expect you to respond with something like: “I don’t believe time dilation or length contraction occur, and thus believe that c is not constant”; "I believe in something like aether dragging"; or “I believe time dilation and length contraction occurs as described in the theory of relativity, and am trying to explain a complementary philosophical concept which you are failing to grasp”.

 

Whether you believe the predictions of modern physics are in some philosophical sense real or not, I believe the mechanics of making them are beautiful and worthwhile to experience, and recommend it for every regular reader of this threads like this one.

[Michael Mooney]

Hi CraigD,

Maybe we could sort this out by examining one piece at a time.

You wrote:

I’ve difficulty imagining this, because as I define a “clock” (for example, in “Implications of the most inclusive possible definition of ‘clock’”), any universe with two or more bodies capable of interacting cannot have no clocks.

 

But Modest and I have been mis-communicating about the nature of time as the duration of two kinds of physical events: One, our manufactured clocks "ticking" at different rates under different circumstances, velocities, gravitational effects (as per altitude differences)... and, Two, the duration of natural cycles like Earth's spin and orbit.

In my opinion he completely misunderstands the difference (and totally "muddies the waters") by such assertions as follows (from his post 781):

 

"The time (or duration if you prefer) of one earth orbit is dilated more and more the greater and greater the velocity from which it is considered, or the stronger the gravitational field from which it is considered. The duration of one earth rotation is shorter in the Dead Sea than on Mt. Everest."

 

I am absolutely sure that "the duration of one earth orbit" does not change with differences in "the velocity... or gravitational field from which it is considered."

I am equally sure that "The duration of one earth rotation is(*NOT*) shorter in the Dead Sea than on Mt. Everest."

 

His assertion is clearly that these natural cycles have longer or shorter duration depending on how our clocks "keep time" differently... which is totally absurd.

 

Maybe if you can clarify the above, we could take it from there.

Thanks

 

BTW, I have no problem with relativity as a math model which works very well for phenomena dependent upon local observation/frames of reference, different velocities, etc.. The thought experiment was an exercise in imagining cosmos without the limits of local frames of reference and time delays in what one can see from such.

 

(I believe Doctordick's math and physics (way beyond me!) illustrate relativity as broken out of local into a universal frame of reference and using "presentism" rather than a focus on the time factor of lightspeed-dependent signal delay .)

 

I disavowed expertise in math in my forum intro, but my masters in philosophy does lend perspective on the concepts, assumptions, and ontology at the core of relativity vis-a-vis time, space, and their supposed "fabric" as one medium.

 

Trouble is, of course that the "bending" of the "fabric of spacetime" has gone way beyond metaphor, so that every mention of relativity reifies space ("bends it"), time ("dilates it") and makes something out of nothing (spacetime.)

 

I hope the latter doesn't get me in trouble again, as all the above are too inter-twined to treat separately.

(Sorry... I didn't stick to my intent to deal with one point at a time.)

 

Michael

[CraigD]

Maybe we could sort this out by examining one piece at a time.

I’m for it. We who live by the extended Brooks’s laws (in particular the usually misattributed, possibly unattributable “1) don’t sweat the small stuff; 2) it’s all small stuff”) practically live the one-piece-at-a-time approach as a lifestyle. ;)

But Modest and I have been mis-communicating about the nature of time as the duration of two kinds of physical events: One, our manufactured clocks "ticking" at different rates under different circumstances, velocities, gravitational effects (as per altitude differences)... and, Two, the duration of natural cycles like Earth's spin and orbit.

In my opinion he completely misunderstands the difference ...

I think this digs close to the roots of our “two cultures” misunderstanding.

 

In the formalism of relativity – either Galilean or Einsteinian – no great distinction is drawn between artificial and natural objects. That some object’s past history involved artifice – interaction with an intention-driven manufacturer – while another did not, is irrelevant to their present and future interaction according to the laws of physics.

 

In principle, our Sun-Earth, or even the entire solar system, could be manufactured. In principle, with an exceedingly small probability, intentionless natural processes could accidentally create, say, a spring-driven pocket watch. Time dilation affects all of these “clocks” indiscriminately. A clock made of springs, escapements, and balance wheels, a planet and a star orbiting their barycenter, two precisely machined metal sphere orbiting their barycenter, a petri dish of growth medium and bacteria, or an aging human being, are all affected by time dilation in accordance with exactly the same factor, which is determined only by the relative velocity and gravitational potential and/or equivalent acceleration of the observed clock and the observer’s clock.

 

Consider another thought experiment:

There is a distant stellar system consisting of a star of nearly exactly the same mass as the Sun, orbited by a planet with nearly exactly the same physical, rotational, and orbital characteristics of the Earth. (For ease of discussion, lets call the denizens of one system Solarians, the other, Correlians) The denizens of both systems have excellent telescopes, and can clearly see each other’s planets. The relative velocity of the two stars is about 22138604 m/s (0.0738464346 c), in a direction about perpendicular to a line drawn between them.

 

Both Solarians and Correlians observe the length of their year (the time it takes their planet orbit their star) is about 365.25 of their days (the time it takes their planet to rotate once). Using their telescopes, both observe that the length of the others year is almost exactly 1 ([math]\frac{365.25}{\sqrt{1- 0.0738464346^2}} -365.25[/math]) day longer than their own.

 

Neither system is more or less “natural” than the other. Neither can be labeled, in a meaningful, absolute sense, the “fast” or the “slow” system. To Solarians, everything Correlian is 1 day per year slow. To Correlians, everything Solarian is 1 day per year slow. There’s no sensible way to say one is wrong and the other right. Each actually observes every one of the other’s time-dependent process, from planets’ orbits to atomic clocks to the average rate of milk spoiling (assuming Correlians and Solarians biology is so similar that both have the same kind of milk and milk-spoiling microbes) as slightly slowed vs. their own.

 

As I tried to illuminate in my light clock thought experiment variant in “An attempt to expand a worldview via modern physics”, there’s no inherent geometric requirement that time dilation occur, but there is that either time dilation occur, or light be observed moving faster or slower than c.

 

Empirical observation strongly rules out light moving faster or slower than c.

[Michael Mooney]

I did say, "I have no problem with relativity as a math model which works very well for phenomena dependent upon local observation/frames of reference, different velocities, etc.."

and I believe this applies to your last thought experiment.

However, I don't think you addressed my specific inquiry at all, expressed as follows:

 

Modest:

"The time (or duration if you prefer) of one earth orbit is dilated more and more the greater and greater the velocity from which it is considered, or the stronger the gravitational field from which it is considered. The duration of one earth rotation is shorter in the Dead Sea than on Mt. Everest."

Me:

I am absolutely sure that "the duration of one earth orbit" does not change with differences in "the velocity... or gravitational field from which it is considered."

I am equally sure that "The duration of one earth rotation is(*NOT*) shorter (edit for clarity: as measured from) the Dead Sea (vs) than on Mt. Everest."

 

His assertion is clearly that these natural cycles have longer or shorter duration depending on how our clocks monitoring them "keep time" differently... which is totally absurd.

 

You write:

"In the formalism of relativity – either Galilean or Einsteinian – no great distinction is drawn between artificial and natural objects."

 

But Modest's claim is that earth's periods of rotation and orbit vary with the point from which they are "clocked."

 

Do you agree or not?

 

I agree that any moving/cycling objects, whether "natural" or manufactured could be considered a "clocks" as can any event to which "elapsed time" can be attributed. But your example totally misses my point and does not address my above often repeated objection to Modest's assertions.

 

Finally, you write ...

"but there is that either time dilation occur, or light be observed moving faster or slower than c."

I certainly don't and never have maintained that light moves slower or faster than C. But, again, ontologically it remains unclear what exactly is considered to be "dilating." Is "time itself" considered to be "moving faster or slower" or is it rather than just physical processes doing so? (Rhetorical.)

Clearly it is the latter, but this still does not address Modest's claim that the length of year and day changes as a result of manufactured clocks "ticking" at different rates under different conditions in different locations while monitoring these natural cycles.

 

I hope all of the above is clear, because I don't know how to present it any more clearly.

Thanks for your further consideration of my still unaddressed objections.

Michael

[lawcat]

1.1 We apprehend time only when we measure "motion" of something, marking it by the terms "before" and "after[A]"

 

YES!

 

1.2 We conclude that B & A are different, and that something thus must be intermediate between them.

 

Yes.

 

1.3 What is intermediate = time, and time is made continuous by "moments" and also divided by "moments".

 

I like to call those COUNTS, but OK.

 

1.4 Each count A & B is a link of time (for each moment connects past and future time), and, at the same time, each count is a limit of time (for it is the beginning of the one [future time] and the end of the other [past time].

 

OK. I agree, we can look at it that way.

 

2.0 Moments have Identity

 

2.1 Each moment is related to a thing that has potential of motion.

 

Here is where it gets tricky: Is each moment really related to a "thing" that has potential for motion? Can a moment be related to something that hsa no potential for motion? Or is it simply that everything has potential for motion? How about concepts, like historical interpretation: Can time be related to the concept of Historical interpretation? For example, at this "moment A" we interpret history this way, but at "moment B" we interpret it another way? I think so. And if so, is historical interpretation subject to motion or merely change of state, whatever the nature of the state of the thing or concept is?

 

2.2 When a thing moves from moment A to B, in one sense it remains the same identity (I move from room A to room :), but in another sense it is different because at one time it is at A, another at B.

 

Yes. It changes state.

 

2.3 Thus, since things when they move in one sense remain the same (have identity), and in other do not remain the same (differ locations), the same for moments. 2.4 Thus, each moment when it links (see 1.4) always remains the same, but each moment when it divides is always different.

 

So you are saying, moments are identical but change state. OK, I can agree with that. EVEN MOMENTS CHANGE STATE, therefore they are subject to counts. No?

 

 

2.5 All moments are indivisible, for if they could be divided, they would be part of time, which they are not.

 

OK. Again, I call them counts for a reason that will be explained later.

 

3.0 Moments are not part of time, but are within time.

 

3.1 There are two ways to think about A & B and relationship to what is intermediate.

3.2 If we consider A & B to differ from what is intermediate we conclude that the two are "moments" (nows, before & after) that are the limits of what is intermediate = time.

3.3 However, when we concentrate on either A or B by itself, not as an identity, but in relation to what is intermediate (time), we see there can be no time within either moment.

3.4 In the same way that two points are not parts of a line (for it is two lines that are parts of a line), two moments are not part of time.

3.5 However, moments (past, present, future) are "within" time, the same way even and odd are within number.

3.6 The moments are thus both a boundary of time, and what numbers time.

 

Fire away.........

 

Again, I agree with this conceptualization of time. but I call moments counts.

 

The reason is that moments have physical connotation. Counts do not. Counts are a constructs of our mind. Time in our mind is a construct of a counter. In physical reality there is nothing but a continuum of changes. The only way for us to relate the changes is by reference to our counter: At this count this happened, and at that count that happened.

The limit of the intermediate is in our mind, but not in physical reality.

[watcher]

Rade, according to you ....

 

 

A --------------------->B

.......TIME............

 

A = moment 1

B = moment 2

 

intermediate between A and B is time.

 

i think this is a classical interpretation of time.

 

in QM interpretation ...

 

particle1 --> moment A --> particle2---->moment B ---->so on so forth

 

1. what is intermediate between moment A and moment B is the "particle". particle and moment are mutually exclusive. the qm transition is that a particle appears and disappears (quantum jump). if the particle reappears in the same position, we say the particle is at rest, if the particle reappears somewhere else. we say it moves.

 

2. in turn ..what is intermediate between particle 1 and particle 2 is the moment.

3. the moment itself has no intermediate because it is indivisible, (quantized).

4. therefore moment itself is already = time=count=cycle/frequency

5, the sequence of these moments is the arrow of time

 

this indivisible moment is what is counted/perceived as time, what are these indivisible moments are the motions of the energy that forms these particles.imho

[hallenrm]

In my humble opinion time and its measurement are very intricately linked. We had on yet another forum called vimarsh discussed about measuring time, may be some of you may like to go through the thread :).

The link to the thread is as follows:

Vimarsh :: View topic - measuring time???

[Michael Mooney]

CraigD,

My last questions to you seem fundamental to the philosophy of science. Please answer.

 

.

.. Modest's claim is that earth's periods of rotation and orbit vary with the point from which they are "clocked."

 

Do you agree or not?

 

And as I said, am not arguing against the constant velocity of light but seeking clarification of the intended meaning of "time dilation."

(We all know it doesn't mean dilation like a pupil in the eye.)

For quick reference:

You:

"but there is that either time dilation occur, or light be observed moving faster or slower than c."

Me:

I certainly don't and never have maintained that light moves slower or faster than C. But, again, ontologically it remains unclear what exactly is considered to be "dilating." Is "time itself" considered to be "moving faster or slower" or is it rather just physical processes doing so? (Rhetorical.)

Clearly it is the latter, but this still does not address Modest's claim that the length of year and day changes as a result of manufactured clocks "ticking" at different rates under different conditions in different locations while monitoring these natural cycles.

 

Along the same lines (philosophically) do you agree with Modest that the distances between bodies in space change with point of observation (different locations and velocities?)

This is clearly a form of subjective idealism, that reality is created by the observation, rather than being independent of same.

Thanks.

Michael

[AnssiH]

Hi, I've been very busy so I'm replying to old post.

 

And, sorry, I am no mind reader. DD does not define in his post "conventional time" as ....something that just metaphysically flows forwards and has "length" by itself, which we call "duration", in the sense that that duration could be anything and varying in any ways, without any noticeable consequences. Apparently DD assumed this concept of conventional time is widely known--but, excuse me, who believes this ?

 

I was a bit sloppy with my post; I meant to just refer to the "conventional view" as in something that exists by itself, as oppose to something that is defined entirely terms of structuring data (where speed and durations are immaterial references to the circumstances found from the data, as it is understood as per some particular definitions).

 

And, when you say ....In your exposition, a clock is being used to measure the random lengths of those "time durations"....you are not understanding what I said. I said that the clock was being used to ensure that the absolutely random times between the call events made were in absolute accordance with the internally consistent consequences of some mathematician putting numbers into the statistics book based on some probabilistic event of creating random numbers. The clock is being used in the context of the mind game situation set-up by DD to "ensure accordance" between two random processes (1) time between calls (2) random numbers in a book. I do hope you see what is being claimed.

 

No, sorry :D

 

If we have moment A (an event, say we acquire 1 new bit of knowledge), then at the next moment B we acquire 7 bits of knowledge, time is what is counted that is intermediate between these two mental events. Perhaps we can measure what is intermediate between these two mental knowledge events using the fission motion of radioactive of isotopes.

 

Either I have no idea what you are talking about, or you are supposing to get the knowledge about that fission motion of radiactive isotopes in between the moments of 2 consequential moments of gaining knowledge or whatever that means. I think you need to put more effort into thinking about how that explanation, that contains the idea of "fission motion" etc, is actually structuring all that data, that is the circumstance referred to as "the fission motion". It's not just ontologically out there for us to look at and measure; we first had to define what we are looking at. That comes with a lot of ontological baggage that I think you are completely overlooking.

 

As I stated in another post, time is the nothingness between such quantum transitions.

 

Quantum transitions are part of your explanation of the data from reality (I'm talking about the epistemological construct where you have defined time measurement means). That is, you are essentially making arguments about unmeasurable aspects of reality, that you just very much want to be one way or another. Why would you do that? I think it is similar to wanting to see the existence of god in ones explanation of nature. It's "the thing that cannot be seen or measured but nevertheless explains everything". Or another way to put it, like I just commented on another thread, it is as if you were talking about "what does the surface of an atom feel like to touch" in your opinion.

 

A naive realist would say it feels exactly what it feels like to touch that object made of atoms. A constructivist would say there is no such thing as the surface of an atom, except in your mind. Those not so well versed in the issue would shout "you silly idealists, of course there is a surface to an atom!".

 

I can understand when you say that "distance" and "time" and "mass" are not meaningful by themselves...of course each depends on something else to gain meaning. Take time for example. As I have explained above, time requires "moments" and "motion" to gain meaning, for without movement from one moment to another there would be no time to measure.

 

I started to reply here because I wanted to make a comment related to that issue (the not-so-obvious relationships between man-made definitions), but I think I'll make another post for clarity's sake. (Right after this one, so hold on :naughty:

 

Einstein tells us time also requires space to gain meaning (GR Theory).

 

This reminds me to point out one thing. Note that in this thread some people are talking about what they think "time" is by itself, and some people are talking about the features of relativity and what those features imply about time in their opinion. I'm mostly concentrating on the latter, because there is actually something to be said there that is little bit more than an opinion...

 

(Einstein doesn't really tell us that time requires space to gain meaning per se, even though the standard way to handle the relativistic definitions is via spacetime. That is to say, spacetime is a handy concept, but it is not necessary for a definition of "time", depending on what that exact definition is of course. But more about that in the next post)

 

A very good book on the philosophic aspects of time that I present, which of course derive from thinking of Aristotle, is found in this book:

 

Ursula Coope - Time for Aristotle - Reviewed by Andrea Falcon, Concordia University - Philosophical Reviews - University of Notre Dame

 

PS/ What I ask is that people read Aristotle first before posting reply to what I say here, otherwise the result will be endless miscommunication, and a waste of time.

 

Right now I'm really just interested of talking about the issues related to the relativistic time relationships, so I think I'll skip your topic myself for the time being...

 

-Anssi