Relativity of Motion discussion from “What is Time”

[watcher]

Ok, we've got the comet orbiting the sun, and then everything disappears except for the comet (all light and gravitational influences become non-existent).

 

to be more realistic, in a big bang model, if all these objects are removed, they won't just disappear. they would be converted to energy. it's like winding up the clock before the formation of these matter, the realistic result would be a very contracted space with very high density. the comet is now beset with tremendous pressure from all directions and its tendency is to shrink to become a black hole. the point is there should still be some form of activity here.

 

With a lonesome comet, the idea of motion, or velocity, becomes non-existent as well.

 

so its only the idea, my friend, only the idea that will cease to exist for you. and just because you have lost the idea how to measure something doesn't mean the universe will stop moving.

 

There is absolutely no way to measure the comet's speed or trajectory.

 

excuse me but relativity is not about absolute measurement neither. so even in a normal situation where comet is surrounded by other objects, it's measurement was always relative. hello

 

and there is a way to measure this without relying on relativity or relative motion. relative motion is an illusion. if an object is slow to that and fast to that, it could only meant one thing, it does not described its true motion or state. if you can imagine a handwave animation ...

 

 

you perceived that the hands are moving in a left to right direction, that is what a relative motion is. you timed the time it takes for the apparent moving of hand from the distance point of the first hand to the last hand and you can calculate the wave velocity.

 

but this kind of motion is only apparent because no hands are actually moving horizontally, the true motion is the up and down (vertically or orthogonally) movement of hands in sync .

 

so the comet will move like this and its measurable.

[modest]

Sorry to jump in out of turn,

 

to be more realistic, in a big bang model, if all these objects are removed, they won't just disappear. they would be converted to energy.

 

Michael's thought experiment was not of converting the matter of the universe into energy. It was, rather, to remove all matter and energy from the universe except for a single object. An empty universe is the most Hyperbolic of the Friedmann cases meaning that the acceleration of expansion would increase if virtually all the matter and radiation were removed. Actually, it would be most-properly called a De Sitter universe (a hyperbolic universe with no matter and positive cosmological constant).

 

it's like winding up the clock before the formation of these matter, the realistic result would be a very contracted space with very high density.

 

Again, the thought experiment is *not* to turn the matter of the universe into radiation. If, however, such a thing did happen the proportionality of the scale factor to time would change from [math]a(t)\propto t^{2/3}[/math] in the case of our matter-dominated universe to [math]a(t)\propto t^{1/2}[/math] when it becomes radiation dominated. The reason for this is because radiation adds pressure which is energy that then affects things globally in a wanting-to-halt-expansion-slightly-more kind of way. But, this is way off topic.

 

the comet is now beset with tremendous pressure from all directions and its tendency is to shrink to become a black hole.

 

The density of the resultant photon gas caused by the transformation of matter across the universe into radiation could not be great considering the density of matter is currently about 5 atoms per cubic meter. But, again, way off topic.

 

 

With a lonesome comet, the idea of motion, or velocity, becomes non-existent as well.

so its only the idea, my friend, only the idea that will cease to exist for you. and just because you have lost the idea how to measure something doesn't mean the universe will stop moving.

If one is to claim that objects have velocity relative to nothing then it is up to that person to explain the concept coherently.

 

and there is a way to measure this without relying on relativity or relative motion. relative motion is an illusion. if an object is slow to that and fast to that, it could only meant one thing, it does not described its true motion or state.

 

Indeed velocity does not describe a body's 'true' motion. If you want to measure the velocity of something you'll have to pick a reference frame from which to measure the velocity and the velocity you measure will depend on the frame. That's the way the universe works.

 

~modest

[freeztar]

to be more realistic, in a big bang model, if all these objects are removed, they won't just disappear. they would be converted to energy. it's like winding up the clock before the formation of these matter, the realistic result would be a very contracted space with very high density. the comet is now beset with tremendous pressure from all directions and its tendency is to shrink to become a black hole. the point is there should still be some form of activity here.

What does this have to do with anything discussed?

 

so its only the idea, my friend, only the idea that will cease to exist for you. and just because you have lost the idea how to measure something doesn't mean the universe will stop moving.

I think you're missing the point.

 

excuse me but relativity is not about absolute measurement neither. so even in a normal situation where comet is surrounded by other objects, it's measurement was always relative. hello

Hi.

You're saying the same thing I am. :)

Until this...

 

and there is a way to measure this without relying on relativity or relative motion. relative motion is an illusion. if an object is slow to that and fast to that, it could only meant one thing, it does not described its true motion or state. if you can imagine a handwave animation ...

There is no "true" motion. That is the whole point.

Relative motion is not an illusion. Hop on a train with a radar gun and I'll stand at the station with a radar gun. As your train passes the station at 50kmh, you begin walking towards the front of the train at 5kmh. You will clock yourself going 5kmh and I will clock you going 55kmh. It is not an illusion, it is relative to who is doing the measuring. And that's not even considering length contraction and time dilation.

 

What is your "true motion" in this case?

It depends on who you ask. It's relative.

 

(The image you tried to post is not showing up)

[watcher]

What is your "true motion" in this case?

Physical objects are not in space, but these objects are spatially extended (as fields). In this way the concept 'empty space' loses its meaning. ... The field thus becomes an irreducible element of physical description, irreducible in the same sense as the concept of matter (particles) in the theory of Newton. ... The physical reality of space is represented by a field whose components are continuous functions of four independent variables - the co-ordinates of space and time. Since the theory of general relativity implies the representation of physical reality by a continuous field, the concept of particles or material points cannot play a fundamental part, nor can the concept of motion. The particle can only appear as a limited region in space in which the field strength or the energy density are particularly high. (Albert Einstein, Metaphysics of Relativity, 1950)

 

okay let's not call relative motion as an illusion, but instead let's asked ourselves how does our perception of "classical" motions ( velocity of objects) originated.

 

according to einstein, the whole shebang of relativity is just energy transfer from 1 point to another. he imagined the world of relativity as a continuous field of varying concentration of energy.

 

enter wave mechanics 101. consider say a tsunami wave. a fault shook under the ocean and sent shockwaves. the energy created a tidal wave that rushes outward the fault with tremendous velocity and hit thailand shores with devastating force. its elementary knowledge that the medium of the tidal wave (water) does not move from indian ocean to thailand shore, the motion of the water is just a vertical up and down motion, and yet the perception that the waves moves or travels horizontally persists. what is actally in motion in this case is the enegy being transferred from the fault to the shore.

 

now if you would imagine that the tsunami waves is the object in space, which is represented as an amplitude of the wave in the tsunami scenario and as in the case of einstein explanation, an energy density transfered from one point to another. it becomes clear that objects must move in an undulatory way just like the water medium in the analogy.

 

to help you imagine this motion, in mathematical terms, it is the vector that is perpendicular to 3d space. which happend to be the 4th dimensional time in relativity. which of course is represented in geometry by the imaginary number (i) part of a complex number.

so time as the origin of motion is a correct . or motion as the origin of our perception of time is correct, which ever float your boat. but of coursethis is not your commonsense ordinary motions. these are the quantum jumps kinda motion.

 

It depends on who you ask. It's relative.

 

yes, but the true motion should be relative to the whole.

[Michael Mooney]

freeztar:

"There is absolutely no way to measure the comet's speed or trajectory."

 

Exactly. But it is still moving as it was before everything else disappeared.You continue to ignore the possibility (which is obvious to me) that cosmos and its parts (including comets) exist in and of themselves independent of human measurement, and they move (as Haley's would continue to move) with or without our measurement. It seems you are unable to grasp this concept.

 

"But, as you say, according to physics, the comet would be moving in a straight line at whatever speed it was going when everything disappeared.But the only way we could know this is to "switch everything back on" and see that the comet is moving at the predicted speed in a trajectory now tangent to our solar system. So, then, we could deduce that the comet must have been moving while everything is off. But while everything is off, there is no way to tell it's motion."

 

As above: By intelligent reason, not requiring constant confirmation by observation/measurement. The sun is still shining on the daylight side of Earth even while it is dark night on the other. Primitive cultures thought it disappeared altogether at night and was reborn every morning. I liken your philosophy to that obvious misconception.

 

Me:

So as I have been saying, Earth's orbit and period of revolution do not speed up and slow down, with every Tom, Dick, and Harry's clocking of them from different perspectives with clocks ticking at different rates. To assert otherwise in the name of relativity is pure nonsense.

 

You:

Actually, to state the opposite is pure nonsense. I'm running out of ideas to help you see this. It's quite easily shown with equations, but since your math is not up to par, I'm not sure how else to get this through to you.

 

Philosophy deals very well with concepts, while math is the technical form of logic which helps to bring a premise or assumption to a logical conclusion. You pull the math-superiority card on me without even realizing what I just said. Math is not prior and superior to the concepts which it quantifies. And I don't think you even realize that you subscribe to the subjective idealism philosophy when you "dis" mine out of hand.

 

You assume a superior knowledge here without even comprehending the philosophy that things exist independently of our observation. You can deny that, as the subjective idealism philosophy does, but most philosophers, excluding the latter*, think that cosmos exists and that its parts move, spin, orbit, etc, whether or not humans are observing them, calculating their velocities, etc.

(* Ed: Also excluding "transcendental idealism" (Kant), constructionism (represented in this forum by AnnsiH, and, I think by doctordick, and, perhaps other idealism- affiliated philosophies.))

Michael

(Post script after reading Annsih"s post above)

As regards my boxed quote above and your contradiction of it, I find AnnsiH's mention of a need for a "macroscopic clock" very interesting:

...and yet to measure the value and behaviour of "C" you need that macroscopic clock to measure it. A bit unfortunate circumstance isn't it?

Seems one of these amazing instruments would help conceptually impaired relativity theorists to see that the duration of an Earth rev doesn't vary with the relativistic measures of "time" as what our present variable clocks measure. (It's variable enough because of "natural causes.)

 

Yet another PS edit:

You told Watcher:

"There is no "true" motion. That is the whole point. "

That is your *philosophy.* Get it? Mine, and philosophers who do not subscribe to any form of idealism say that there is true motion, as cosmos is not dependent on human perception, limited as it is by relativity.

BTW, I agree with AnnsiH (amazing!) that :

Note especially that none of that is saying that relativity is invalid model. The important bit is to understand exactly how does relativistic idea of reality arise as a necessary feature of your world model, while it never was a feature of the content of the data that your world model explains.

 

I would add that before relativity the world was pretty much as it is post-relativity, regardless of sophisticated "models" (which relativity certainly is... for the local ground and relative measures it covers.

 

Sorry this post went so long. Trying to keep up with Annsih!

M

[RCP/CRT/RRT]

Michael, I don't see anyone denying the comet, or the universe for that matter, exists in the absence of an observer. It appears they are claiming that without any reference points there is no way to measure its velocity up, down, sideways. For the purposes of the thought experiment you can imagine an infinite empty volume. Removing any previous knowledge of the comets motion, as if there never was anything else. It seems rather impossible to make any measure of a constant motion. Even if you had two plain spheres, one in constant motion, and you were viewing from the perspective of one, you would not be able to determine which was the one in motion.

 

If you are going to claim otherwise, what, and where is your absolute reference or clock?

[Michael Mooney]

RCP/CRT/RRT;282266]Michael, I don't see anyone denying the comet, or the universe for that matter, exists in the absence of an observer. It appears they are claiming that without any reference points there is no way to measure its velocity up, down, sideways.

 

I was offering the experiment for contrast, a different philosophy than the absolute dogma of relativity that rules here.

I refocused on the philosophy of science and the ontology of time in post 894, opening as follows:

Section heading: Philosophy of Science... Thread: What is time....

...that the cosmos and all its parts have an existence and a dynamic including rates of rotation/orbit, trajectories and (velocities of .. edit out if it introduces conflict of terminology)...movement independent of homosapien science and its measurements."

 

The whole point of "disappearing" all but the comet in my thought experiment was, as you said ..."that without any reference points there is no way to measure its velocity up, down, sideways."

I also explicitly and with exclamation declared... "Wow... no observer!"

You continue:

For the purposes of the thought experiment you can imagine an infinite empty volume. Removing any previous knowledge of the comets motion, as if there never was anything else. It seems rather impossible to make any measure of a constant motion.

I did imagine infinite empty volume, but for the comet. I did not, however remove "any previous knowledge", but, on the contrary, said that its motion would continue at the same speed (now unmeasurable) as before but with a straight line vector in absence of sun's gravity.

 

Even if you had two plain spheres, one in constant motion, and you were viewing from the perspective of one, you would not be able to determine which was the one in motion.

 

Like all other "absolute relativists" here, you

seem unable to imagine a thought experiment with *no reference points*, illustrating one body's continued motion *in and of itself.* Sorry.

 

If you are going to claim otherwise, what, and where is your absolute reference or clock?

As above. Existentially, the comet in the contrived situation continues to exist and move "all by itself" with *no observers at all.*

 

Michael

[RCP/CRT/RRT]

I'm not going to try and convince you of relativity's likelihood to reality. You believe what you want, if you don't "want" to accept the possibility, you'll never be open to it... It just makes you a bad scientist, not a bad person.

 

How you can make a measure of anything with out an observer is non-sense & ridiculous. In and of itself the comet likely has no awareness, even if it did (uh-oh, observer), theoretically, it would have no way to distinguish its bearings or motion without something for reference.

[modest]

Like all other "absolute relativists" here, you

seem unable to imagine a thought experiment with *no reference points*, illustrating one body's continued motion *in and of itself.* Sorry.

 

The concept of "motion" and the concept of "in and of itself" are mutually exclusive. What happened was, you have an intuitive idea in your head—it goes something like this: "there are things and some things have motion". That's the idea. And, it's a very powerful human idea. It's an intuition. It's the same intuition that a Topi has on the African Savanna. Everything is motionless. Topi eats in the short grass. Suddenly... the Topi's brain screams: "MOTION!". It's a cheetah and the Topi runs for its life.

 

Scientists have done studies on animals. There actually is neurocircuitry in our brain that signals "motion". So, sure, Cheetah's have motion. You know it as surely as the topi knows it. But, you can't define it. You can't describe reality with it. You can't explore its logical consequences. Can you? No. At this point you've demonstrated your inability to do so.

 

That's ok. You've got 5 or 10 people here trying to explain. The intuitive concept of an object having motion is either not complete or not internally consistent. Motion is a frame-dependent quantity. It is what you get when you compare one thing to another thing. When the topi's brain evolved, it probably had no need for that. In the topi's mind, if a cheetah is running at it then the cheetah has motion. If the topi decides to run then the topi's brain will say "I have motion". That's all the topi needs. That's all we needed to evolve. It ends up that the topi was comparing everything to the ground but didn't even realize it.

 

Humans got smart and figured out that the ground had motion. But, wait, if the ground has motion and we are at rest on the ground then we have motion with the ground, but we're at rest, but we have motion.... and then the whole idea of "have motion" breaks down. When that happens you find a smart fella perhaps named Galileo and demand that he fix the problem. And, he does. He works out Galilean invariance (or "Galilean relativity" if you're not scared of the "r" word) some 400 years ago. He says that if you're in the hull of a boat you'd be tempted to use your human intuition to say "Boat have motion", but that motion is actually a 2 object ordeal. The boat itself doesn't have a local property "motion", but rather has a velocity relative to the water. There's no experiment that can be done by a person in the boat hull that tells them "boat at rest" or "boat have motion"

 

And, now, hundreds of years later this has become obvious to us. We all grow up knowing that the earth is rotating, it's moving different speeds with respect to different astronomical things. We grow up experiencing "at rest" as judged by our tommee tippee cup while in a car that has motion. We 'get' that we are at rest *relative* to the car and moving *relative* to the road. The topi doesn't get that. It has no such experiences that it is able to use critical reasoning skills to extrapolate from.

 

So then... there is a single object and nothing else in existence. Is it at rest or does it have motion?

 

The answer is that "at rest" and "have motion" are not meaningful concepts. They are incomplete. One must specify what exactly this object is at rest or moving with respect to. Since there is only one object it makes no sense to say it is moving or that it has velocity or that its distance is increasing per unit time or that it travels less than 100 miles per hour but faster than 90 miles per hour or that it is listing lazily to the left or that it is the fastest thing in the universe or that it's the slowest. Those things don't make sense because things necessary to physically satisfy the condition of those statements are absent in the thought experiment.

 

~modest

[watcher]

I'm not going to try and convince you of relativity's likelihood to reality. You believe what you want, if you don't "want" to accept the possibility, you'll never be open to it... It just makes you a bad scientist, not a bad person.

 

How you can make a measure of anything with out an observer is non-sense & ridiculous. In and of itself the comet likely has no awareness, even if it did (uh-oh, observer), theoretically, it would have no way to distinguish its bearings or motion without something for reference.

 

Lorentz transformation was the result of attempts by the eponymous Hendrik Lorentz and others to explain observed properties of light propagating in what was presumed to be the luminiferous aether; Albert Einstein later reinterpreted the transformation as a statement about the nature of space and time themselves and derived it from the postulates of relativity. - wikipedia

 

einstein relativity's logical foundation was the lorentz equation of electron charge plus the Galilean relativity.

 

on the other hand, lorentz transformation was founded on aether theory. which meant that lorentz used absolute space as his reference. this meant that particle and emf were the result (assumed by deep thinking lorentz) of undulating/vibrating ether (the medium of motion). now just replace the word ether with quantum vacuum of space and see how close lorentz to the modern theory of QM even though he was in his twilight years when QM began.

 

it wasn't clear to me why Al chose or considered only the relative of motion between particles and left off the absolute space part when it was clear that he also believed space was not empty (perhaps the math is easier ). but that's the story. relativity is a subset theory of lorentz transformation

[watcher]

So then... there is a single object and nothing else in existence. Is it at rest or does it have motion?

 

if you consider this single object as the universe as a whole and ask the same question ,,, is the universe at rest or in motion? what would be the answer? you can refer to modern cosmology for an educated guess i suppose.

[freeztar]

if you consider this single object as the universe as a whole and ask the same question ,,, is the universe at rest or in motion? what would be the answer? you can refer to modern cosmology for an educated guess i suppose.

 

It still has the same answer..."I don't know/not enough data".

[Michael Mooney]

Modest:

The concept of "motion" and the concept of "in and of itself" are mutually exclusive.

Not really, but one needs the ability to imagine reality beyond local frames of reference, to "think outside the frame."

The comet was moving before everything else disappeared, and it will continue to move "in and of itself" as an object independent of all observation and measurement... i.e.,independent of anyone for whom motion has meaning only "with respect to" at least one other point of refererence, the observer... now absent.

 

This is not about my supposed lack of understanding of relativity or what you are constantly repeating here about the need for frames of reference. I have presented the philosophy of cosmos, world, objects, and all dynamics thereof "in and of themselves" not requiring observation for that existence and dynamics. It is you who are unable to grasp such a philosophy, and in fact deny its validity altogether. This does not surprise me as you are an *absolute relativists* and you believe that no other reality (the objective existence of a world independent of observation) is possible or valid.

 

So your whole long-winded discourse on topi sensation/perception of motion is totally irrelevant given your absolute rejection of an alternative to the philosophy that "everything is relative." There is really nothing more to discuss with you about it since you reject the existence of things and their motion "in and of themselves." I get that it has no meaning *to you* and will stop trying to convince you otherwise.

 

But you can disabuse yourself of the conviction that my disagreement with you proves that I just don't get what you and all those others are saying... that I just don't get relativity. Just as my repeating it doesn't make it so, repeating that I don't get it, as you all do, doesn't make that so either.

So I have shared my philosophy of science as per "time."

Enough already.

Michael

[modest]

So your whole long-winded discourse on topi sensation/perception of motion is totally irrelevant

 

I don't know... Seems pretty spot on to me. You think the comet is moving in just the same way the topi thinks the cheetah is moving. See...

 

The comet was moving before everything else disappeared

 

You can't define what you mean by that. You can't explain what it means for something to "have motion". It's just that your brain says "comet move" in the same what a topi's brain says "cheetah move".

 

You, for whatever reason, can't see "comet move" is an incomplete concept :)

 

~modest

[watcher]

I came to this forum disclaiming math expertise but still challenging the ontology of "spacetime" the concept as having no referent in "the cosmos"... like a malleable medium/"fabric", etc.

But the "go to evidence" is always presented as math/physics, ignoring said ontology and conceptual challenge.

 

because the tensor math of GR represents the spacetime malleability of the cosmos. these are called force fields , the "conceptual entity" that connects matter. the answer to the question why and how matter attracts one another.

 

now, if you would dismiss this space time distortion and claim that space in nothingness, you are dismissing the gravity force field and you must therefore introduce another entity (at least even in theory/concept) that would link two bodies of mass, since empty space can't mediate between two objects.

 

by claiming space empty and dismissing relativity at the same time (yes they mean the same thing) you have left these objects orphaned and no link to one another. do you now understand the frustration here?

[AnssiH]

Hi Freeztar, it was very nice to see you took my last post seriously and made a real attempt to understand what I was trying to say. I hope this post will further explain to you what's going on with DD's analysis.

 

Several months ago, I made an attempt to see what DD was on about. I sent him a PM with a question about one of his algebraic expressions. Apparently he didn't like my level of math, so instead of trying to walk me through it, he told me that it would be "a waste of my time" to attempt to understand. :phones:

 

I'd say that is quite dismissive for someone actually trying to understand. So, he can't claim that no one will take it seriously when he rejects an attempt at understanding it. I'm happy to take his word for it and not pursue his ideas, but it's a bit hypocritical to denounce my understanding of it. Wouldn't you agree?

 

I can't really speak for him... Perhaps he felt it's not time well spent to talk about it in private messages? Anyhow;

 

My first impression were certainly of the "idealistic ontology" type, but I wouldn't say crazy.

 

Then you know how easy it was to jump into trying to imagine "what reality is like" given the terms he was talking about. When actually, there was no argument made about reality itself. Nothing was asserted about the "ontological form" of anything.

 

The presentation revolves explicitly around the circumstances that arise, when some data - whose meaning is "unknown" - is transformed into an orderly model related to that data. All the consequences that are shown to exist, are happening due to that transformation process, and are explicitly its features (i.e. they are epistemological features, not ontological features).

 

The argument is, that the relationship that exists between the raw data, and the man-made definitions referring to some features of that data, can only be based on recurring patterns in some sense (since the meaning of the data is unknown). As a consequence of that, few symmetry requirements apply to those resulting definitions (in terms of how the prediction function must behave). Those requirements apply to a valid worldview, even when we still do not know anything about the ontological meaning of the data.

 

When the above is put together in a more analytical manner, we get the "fundamental equation", which is simply a succint algebraic expression of those symmetry requirements (expressed as necessary features to the probability function).

 

Those requirements really need to be looked at in a fairly analytical fashion, but I hope the above gave you an idea about how the presentation is not really about what reality itself is like (nor does it assume idealism is correct), but about the features of our worldview, due to the transformation from "unknown patterns" into a form of "a set of discreet entities".

 

ps, I'm sure you've heard DD say "the difference between an electron and a volkswagen is the context" many times, and people seem to miss what he means by that. What he means is that the definitions of those entities were based on patterns/context arising from initially unknown data. You can't take it as a given information that "there is an electron there"; you first have to take into account that the recognition of "a thing" had to do with a great volume of raw information, which only after some transformation is crunched into the simple form "oh look, an electron". It is the features of that transformation process that need to be looked at analytically.

 

The actual issue is that when you take any random noise, it can always be modeled in terms of persistent entities (think of the assumptions required to be able to think about "objects" in "motion").

I'm not sure I understand what you mean here.

 

I mean that, while you can't say that there is any explicit information about the existence of any "objects" in the "unknown patterns" (it is "unknown" after all), it is interesting to note that we can transform those patterns into an idea of "a set of persistent objects" that "move" around. Given enough random data, one can always find features/circumstances that become picked up as "objects".

 

To convince yourself of that point and how it actually works, might require looking at the analysis more closely, but note that after that transformation, we will think that "pattern A" at time t=0 is "the same object" as "pattern B" at time t=1. I.e. in terms of the raw data, each recurring instance of a particular pattern is "a different thing", but in terms of our worldview, objects hold persistent identity to themselves.

 

Or another way to put it, in our minds we define "things" that "move" (Nothing can "move" without the idea of "persitence of identity", or "persistent objects"), and that is entirely an epistemological issue. Unless of course one wants to make undefendable assumptions about ontology. We don't. Instead we take those defined "persistent objects" simply as immaterial references to some recurring circumstances/patterns in the data. (And that will turn out to be very useful)

 

He means, there actually exists an explanation as to why do we see the universe the way we do, so there is no reason to say "the universe just is that way and no one knows why". I.e there is a good reason why the relativistic model is valid, as a model.

So, there's a valid epistemoligal explanation for why we perceive things the way we do and why our models work, but what about ontology? In the context of this thread, what are the assumptions about time, ontologically?

 

There are no ontological assumptions nor conclusions about time, but finding the epistemological reasons for relativistic time relationship means that there is absolutely no reason to believe that the validity of relativity tells us something about ontological reality.

 

Let me be clear about that; the relativistic time relationships really are shown to be rooted to the transformation process from "unknown patterns" to "persistent entities exhibiting predictable behaviour", just in a not-so-obvious way (that's where the algebra comes into play; very powerful tool in logic).

 

That of course doesn't disprove the existence of relativistic spacetime (that common general relativistic worldview) for anyone who really wants to believe in it. Just like the evolution theory doesn't disprove creationism for anyone who really wants to believe in it. But it does turn relativistic spacetime into an excess belief; somewhat redundant for one's understanding of reality. Textbook naive realism actually.

 

How is the ontology not relevant in terms of assuming it "just is"? Are you suggesting that the ontology is irrelevant given the proper epistemological constraints?

 

Yes, because you will find that most of the common ideas of what reality ontologically is, are (surprisingly enough) features of the data ordering mechanisms (epistemological tools) in our head, rather than features of the content of the data itself.

 

I.e. there is no real reason to see those features as "what reality is like", any more than there is reason to expect "God" to exist, even though I cannot really disprove either hypothesis...

 

You could say that our idea of reality is a matter of interpreting it that way, but to understand how that is possible, you need to be able to look at the matter from the very fundamentals, all the way from understanding how does any definition of any "thing" arise at all.

 

In fact that presentation exposes a lot of "excess beliefs" often lumped together with modern physics. (In terms of what is a matter of interpretation and what is a consequence of particular definitions and so on)

Can you give some examples?

 

I think the epistemological basis of "space" and "time" are the most important examples (if you think about how the exact definition of "space" is a function of your exact idea of how "objects" hold persistent identity), but also the belief that locality is required for realism has to do with taking relativistic simultaneity too seriously. And the difficult results of QM when the idea of "motion of a real entity" is taken too seriously rather than as an "idea" resulting from particular definitions on unknown patterns (think about the Bell experiments).

 

Perhaps you can appreciate the fact that the value and behaviour of "C" in Maxwell's equations does play a role in your expectations as to how a clock internally works (and what it yields as a measurement), and yet to measure the value and behaviour of "C" you need that macroscopic clock to measure it. A bit unfortunate circumstance isn't it?

In so far as it seems circuitous, yes, it is a bit unfortunate.

Though, in this case, it seems it's similar to the chicken and the egg argument. But unlike the chicken and the egg argument, the chicken and the egg are concurrent.

 

I'm not sure if that made much sense, but hopefully you will see what I'm getting at and can clear up any misconceptions I might have, as it relates to DD's work.

 

I guess what you were getting at was that they explain each others in self-coherent fashion. And yes, that is true, and of course many self-coherent explanation schemes are open for us.

 

But the reason I was bringing it up was that C in Maxwell's equations is something that plays a role in prediction of when and where electromagnetic information interacts in a dynamic system; Its speed is not measured by clocks per se, but it is first related to that "evolution paramater" I was talking about. The statement "when 2 things are at the same place at the same time, they can interact" defines that evolution parameter, not "that which is measured by the clocks".

 

I'm sure you can understand that an evolution parameter of that sort is a required concept to a worldview. The point of your worldview is to make predictions after all, and if you understood the above commentary about "persistent objects/their motion", you understand that some idea of timewise evolution is playing a role there. In particular, it is playing a role in your expectations of which entities are going to end up in interaction.

 

He was just saying, in a bit roundabout way, that two clocks, after making trips and returning back together, will not display the same measurement. So the statement "2 objects in same place at the same time can interact" refers to one definition of time, and "a clock measures time" refers to another definition of time; they do not co-incide. Simple as that.

Ok, I think I see it now. In the latter definition time is absolute, or at least doesn't include relativity like the former does. Yes/no?

 

Well, that wasn't the point I was making... Being that an evolution parameter is necessary prediction tool, and being that it is associated with your definition of C (and many other things), and being that after walking through the epistemological analysis it is clear that your expectation of what clocks will measure, is quite different from how that evolution parameter works, it should become clear that one should be careful at keeping those definitions explicitly separated.

 

You can choose to agree with the definition "Time is what clocks measure", and then you agree that "Different clocks measure different amounts of time", and then you agree that "Time is different for different observers", but then you can't agree with "if we'll be there at the same time, we will meet each others". Each looking at their own clocks, you won't meet, even if according to your clocks you were there "at the same time".

 

Unfortunately, you do agree with that last definition in your thinking as well, more or less intuitively, because it is already playing an important role in your worldview. It will keep popping up, and it does appear in Maxwell's definitions in exactly that sense.

 

That difference in behaviour between the "evolution parameter" and "what electromagnetic clock would be expected to measure" is exactly what special relativity is a statement of, and there are few things playing a role in how that works, one being the necessary transformation to your solution (your predition function) between moving coordinate systems.

 

That's why I said "the value of C can be treated in many different ways when you go to perform a coordinate transformation between moving frames". It is of course completely immaterial which way you treat it as long as you keep the relationships between things intact (much like you are free to perform all kinds of algebraic manipulations to an equation without making it invalid), and relativistic treatment is just one way to do it.

 

I agree. Perhaps to that end you could address the strange counter-examples and how they do not relate?

 

Well for instance, the post #909 insists "time" is exactly what is measured by the clocks.

 

Nevermind how you define it, the argument was that the 2 definitions are mutually exclusive. I.e. if you were to synchronize the flight paths of airplanes according to the clocks they carry onboard, then eventually there would be mid-air collisions.

 

Of course any elementary school student having heard the first bit about relativity understands the above. The difficulty seems to be in recognizing what does it matter that the two definitions are muddled up together. It may not be immediately obvious, but it does become quite obvious with the epistemological analysis.

 

At the end of the same post, Modest suggests a mechanical device that will tell whether 2 cars will collide at an intersection. Only, he is talking about 1 clock sitting in the intersection. Another way to put his argument is that "a single clock" displays "a single time" when there's a collision. Well, of course. A single clock, or a toaster, or a candle or any system at all will display only 1 state at the moment of 1 event.

 

Following the same tack;

You’ve come to the conclusion with no given logic or reasoning that “a clock measures time” should mean that the proper time for any time-like curve between events will be equal. This is not a good conclusion.

 

That is not what this is about at all.

 

It is about the epistemological requirement of being able to tell whether 2 things will interact or not, and about how at the end of the road, the expected measurement of clocks is completely different thing, as per how they are defined as objects from the unknown patterns, following the symmetry requirements.

 

The rest of that post is pretty much just explaining the relativistic definitions, and implying that anything else is making matters more complicated (as if proper-time curves were a feature of any valid world view?).

 

If you read the post, you can see he also says "[co-located] events are simultaneous if they have the same point in time". Notice the use of the word "time" in that context. Following that definition, then the clocks don't measure their "point in time". Maybe he is saying that "time" is what clocks measure and "point in time" is what an evolution parameter displays? That is just semantics and unrelated to the actual issue.

 

Anyway, if you are picking up on what the actual problem is, and if you then read that post #916 carefully, you can surely see it's really not even touching the topic at any point (which is fascinating all by itself).

 

Honestly, it's a bit amusing how this argument about proper time always seems to crop up at this point, as if someone with a Ph.d in nuclear physics didn't know all that. Maybe, just maybe, there is a real reason DD keeps bringing that up? Maybe it really does turn out there are not-so-obvious connections between evolution parameter of a worldview, the physics definitions that make up a "clock", and the expectations of how that clock must be expressed in terms of moving coordinate systems? If you trace those connections, you can see that the expression of a clock just cannot be expected to measure the evolution parameter itself, and how that has got nothing to do with reality itself.

 

Ok, I think I follow.

 

Ok, that definitely helps.

 

Great, I hope with this post you have even better idea as to what this is about. I think, to convince yourself you'd have to look at the math, but I think even without the math you can probably convince yourself that there can be serious consequences to be found from symmetry requirements (their interplay) to prediction functions, when those prediction functions are based on familiarity on recurring patterns.

 

A question: What does this mean for physics then? Is it trivial and only really important at a "micro" level, or are there direct and profound consequences?

 

Yes I would say so, as it explains where the odd features of relativity and quantum mechanics are coming from (and why there is the difficulty to connect them), without the need to believe in any extraneous interpretations or assumptions.

 

The fact that the explanation revolves around the transformation process from "unknown patterns" to "persistent entities that move" means that no one will be able to find any conclusive interpretation or explanation to quantum mechanics as long as they hold on to the idea that world is ontologically made of objects that they have defined. At least that is my expectation, since Bell inequalities are violated by QM predictions (and experiments). That is not expected if you hold on to the realist idea that world is really made of the things we say it is made of.

 

But it is absolutely expected by the symmetry requirements of that transformation process (given the approximations/assumptions that lead to QM formalism). The reality behind the patterns remains unknown, but the transformation process alone gives you the QM-like model of those patterns (with the collapse of the wave function and everything).

 

Thanks for taking the time to explain this, Anssih. I'm still far from understanding this (and all the implications), but I feel that much closer.

 

Great

 

-Anssi

[Michael Mooney]

watcher:

because the tensor math of GR represents the spacetime malleability of the cosmos. these are called force fields , the "conceptual entity" that connects matter. the answer to the question why and how matter attracts one another.

 

now, if you would dismiss this space time distortion and claim that space in nothingness, you are dismissing the gravity force field and you must therefore introduce another entity (at least even in theory/concept) that would link two bodies of mass, since empty space can't mediate between two objects.

 

by claiming space empty and dismissing relativity at the same time (yes they mean the same thing) you have left these objects orphaned and no link to one another. do you now understand the frustration here?

 

The above is about space, not time... but a brief reply anyway.

We all know that electromagnetic and gravitational forces travel through space, whatever we conceive that to be, or *not* as in "nothing, emptiness, just volume."

I have no problem with these forces traveling through "empty space." Maybe after quantum entanglement is better understood we can transfer that understanding to those macroscopic forces "through space" as well.

What do you think is the "medium" for the instant, unbroken informational link *at a distance* between entangled particles?

 

Wiki says that this very mysterious connection "... defies both classical and relativistic concepts of space and time."

 

It is humbling that we don't know the nature of the "medium, space."... or even if it is a "medium" other than emptiness. But this is no justification for simply "making something out of nothing" because we can not conceive of "nothing" with forces and information traveling through.

"Action at a distance!... oh no!" We simply can't have that!

 

Michael