Frame of Reference as Subject in Subjective Idealism

[owl]

I doubt it. I don't see how you would "eliminate" spacetime.

 

There is no quantum theory of gravity. Whether it would be an alternative depends how you are using alternative. It would not replace GR where GR works, only where GR fails.

Doesn't the principle of Occam's razor just "cut out" stuff in theories that are not required... like for gravity to work?... I mean, since nobody knows what "it" (spacetime) is anyway?

 

To this point, while I was trekking around the realm of "quantum gravity" I found (again) this well known support for relativity and its spacetime concept (referenced also below):

 

General relativity scored a knockout blow when Einstein predicted the motion of Mercury with greater accuracy than Newton’s theory of gravity could.

 

What part did curved spacetime play in the above that was such an improvement over old fashioned Newtonian gravity? (A sincere question.) Would a math symbol for "mysterious medium" (MM) have worked as well for the predictive math as making spacetime a malleable medium, an entity in the ontological sense?

 

Now to "quantum theory of gravity"... and yes, it is relevant to the topic as challenging *parts* of relativity:

 

What do you think of this Scientific American article at:

http://www.scientificamerican.com/article.cfm?id=splitting-time-from-space ?

 

Splitting Time from Space—New Quantum Theory Topples Einstein's Spacetime

 

“The snag is that in quantum mechanics, time retains its Newtonian aloofness, providing the stage against which matter dances but never being affected by its presence. These two conceptions of time don’t gel.”

 

“General relativity scored a knockout blow when Einstein predicted the motion of Mercury with greater accuracy than Newton’s theory of gravity could.

 

Can HoYYava gravity claim the same success? The first tentative answers coming in say “yes.” Francisco Lobo, now at the University of Lisbon, and his colleagues have found a good match with the movement of planets.”

 

Then there is this from Physlink.com

http://www.physlink.com/education/askexperts/ae620.cfm

 

What is the quantum theory of gravity?

 

When it was discovered in the early twentieth century that Newtonian physics, although it had stood unchallenged for hundreds of years, failed to answer basic questions about time and space, such as 'Is the universe infinite?' or 'Is time eternal?', a new basis for physics was needed.

 

This lead to the development of Quantum Theory by Bohr, Schrödinger and Heisenberg and Relativity Theory by Einstein. This was the first step in the development of a new basis for physics. Both theories, however are incomplete, and are limited in their abilities to answer many questions. Quantum Physics deals with the behaviour of very small objects, such as atoms, why they do not disintegrate as Newtonian Physics wanted. The theory of Relativity, on the other hand deals with much large scales, celestial bodies and others.

 

Both theories fail when confronted to the other's 'domain', and are therefore limited in their ability to describe the universe. One must unify these theories, make them compatible with one another. The resulting theory would be able to describe the behavior of the universe, from quarks and atoms to entire galaxies. This is the quantum theory of gravity.

 

(Comments?)

Most basically, how do you think Newtonian physics failed to answer the questions, "'Is the universe infinite?' or 'Is time eternal?" Seems pretty obvious to me that there can be no "end of the universe" as I've argued in threads here on that topic. ("What boundary? What on the "other side" of a proposed boundary?)

And, of course, if time is the Event Duration of Physical Processes, then as long as there have been and will be physical processes (objects moving around) time remains the duration of those processes. What would an "end of time" look like? All moving objects somehow vanish?

 

From the Ontology of Time thread:

swansont;

I suspect Cap'n is getting tired of repeating himself, and I know I've answered this before. The concept has been clarified, and yet you continue to repeat the same misconceptions. Each frame of reference yields a different answer. None can be regarded as universally true, i.e. there is no "real" length with all the others being "fake" or illusory. There cannot be, because there is no objective way to determine who is at rest and who is moving.

 

Please check thread title. This thread is here to examine the difference between a philosophy of science based on investigating an objective world/universe which exists independent of observation/measurement/frame of reference vs one in which reality (the world/universe) depends on perception of it from very different frames of reference.

If the former, then it is as it is regardless of how we "see" it. Then, when we see earth as an oblate spheroid, we know that is a distortion of its true and well established shape as nearly spherical, and we have a good idea of why it is so distorted. This is a philosophical alternative to the claim that all frames yield equally valid measurements.

 

Same with the equal length rods as compared side by side vs viewing one of them from an extreme velocity frame of reference (or bringing one rod to high velocity.) The " objectively universe" philosophy (as contrasted with relativity) says that the rods are as they are independent of extreme frames for measurement... that one does not become way shorter, as so measured, and then return to its original length when brought to rest beside its identical twin.

 

You continue:

The substance of your argument is that you are the one reifying time and distance, which makes it very convenient to rebut, since nobody else is truly reifying them. That's why it's a strawman. You are misrepresenting relativity. It would behoove you to study the physics and develop an understanding of it before you trash it.

I am not reifying time. There is no "it" to dilate or to be "woven together" with space. Our clocks simply tick more slowly at high speeds and different gravitation fields. (Often repeated.)

 

I am not reifying space/distance. Between objects *in space* is distance, which varies with their movement relative to each other. The distances between them does not vary with every high speed frame of reference from which they are measure, according to a philosophy of an objective universe independent of measurement differences, as above.

When relativity says that "for a photon" (traveling, of course, at light speed), there is no distance between earth and sun and no elapsed time for traveling that "no distance," this does not make the distance between earth and sun, in the "objective universe) zero. The claim that both measurements (one AU and zero distance) are equally correct is patently absurd. Does anyone here really believe that zero distance to sun and zero photon travel time is "equally correct" with the well established AU and the 8+ minute travel time for sunlight?

Enough for now.

Edited July 15, 2011 by owl

[swansont]

Please check thread title. This thread is here to examine the difference between a philosophy of science based on investigating an objective world/universe which exists independent of observation/measurement/frame of reference vs one in which reality (the world/universe) depends on perception of it from very different frames of reference.

If the former, then it is as it is regardless of how we "see" it. Then, when we see earth as an oblate spheroid, we know that is a distortion of its true and well established shape as nearly spherical, and we have a good idea of why it is so distorted. This is a philosophical alternative to the claim that all frames yield equally valid measurements.

 

Same with the equal length rods as compared side by side vs viewing one of them from an extreme velocity frame of reference (or bringing one rod to high velocity.) The " objectively universe" philosophy (as contrasted with relativity) says that the rods are as they are independent of extreme frames for measurement... that one does not become way shorter, as so measured, and then return to its original length when brought to rest beside its identical twin.

 

You can't both hide behind the thread title and continue to bring up (and misrepresent) the physics. If you want to discuss philosophy, then discuss philosophy. Einstein's Relativity is not philosophy — it makes testable predictions.

 

You continue:

 

I am not reifying time. There is no "it" to dilate or to be "woven together" with space. Our clocks simply tick more slowly at high speeds and different gravitation fields. (Often repeated.)

 

You do it as a strawman: "Once we get over the reification of time as an entity…" But you have not shown anyone in this thread who is reifying time. It's a setup to prove your point by misrepresenting the position that others hold.

 

 

I am not reifying space/distance. Between objects *in space* is distance, which varies with their movement relative to each other. The distances between them does not vary with every high speed frame of reference from which they are measure, according to a philosophy of an objective universe independent of measurement differences, as above.

When relativity says that "for a photon" (traveling, of course, at light speed), there is no distance between earth and sun and no elapsed time for traveling that "no distance," this does not make the distance between earth and sun, in the "objective universe) zero. The claim that both measurements (one AU and zero distance) are equally correct is patently absurd. Does anyone here really believe that zero distance to sun and zero photon travel time is "equally correct" with the well established AU and the 8+ minute travel time for sunlight?

Enough for now.

 

Is there a way to objectively test anything related to an "objective universe"?

 

The Lorentz transforms are for inertial frames, and a photon is not in an inertial frame. It is an overreach to apply the equations where v=c

[tar]

Einstein's Relativity is not philosophy — it makes testable predictions.

 

And I suppose no logic is involved in this process?

 

No love or pusuit of wisdom by intellectual means and moral self-discipline?

 

No investigation of the causes and laws underlying reality?

 

No inquiry into the nature of things based on logical reasoning rather than empirical methods?

 

No critique and analysis of fundamental beliefs as they come to be conceptualized and formulated?

 

No synthesis of all learning?

 

No (archaic and historic use) investigation of natural phenomena and its systematization in theory and experiment as in alchemy, astroloogy, or astronomy (hermetic philosophy;natural philosophy)?

 

No learning excluding technical precepts and practical arts?

 

No diciplines presented in university curriculums of science and the liberal arts, except medicine, law, and theology (Doctor of Philosophy)?

 

No science comprising logic, ethics, aesthetics, metaphysics, and epistemology?

 

No system of motivating concepts or principles (the philosophy of a culture)?

 

No basic theory or viewpoint?

 

No system of values by which one lives?

 

No calmness, equanimity, and detachment thought to befit a philosopher?

 

(Taken from the definitions of Philosophy in The American Heritage Dictionalry of the English Language, 1976 Houghton Mifflin Company, with a "no" infront and a "?" behind.)

 

I do not think you can make a prediction, without a metaphysical concept of an objective reality that will act in a predictable way.

 

Could Einstein have put together a working mathematical model of reality without "thinking" about it?

 

Regards, TAR2

[swansont]

And I suppose no logic is involved in this process?

 

No love or pusuit of wisdom by intellectual means and moral self-discipline?

 

No investigation of the causes and laws underlying reality?

 

No inquiry into the nature of things based on logical reasoning rather than empirical methods?

 

No critique and analysis of fundamental beliefs as they come to be conceptualized and formulated?

 

No synthesis of all learning?

 

No (archaic and historic use) investigation of natural phenomena and its systematization in theory and experiment as in alchemy, astroloogy, or astronomy (hermetic philosophy;natural philosophy)?

 

No learning excluding technical precepts and practical arts?

 

No diciplines presented in university curriculums of science and the liberal arts, except medicine, law, and theology (Doctor of Philosophy)?

 

No science comprising logic, ethics, aesthetics, metaphysics, and epistemology?

 

No system of motivating concepts or principles (the philosophy of a culture)?

 

No basic theory or viewpoint?

 

No system of values by which one lives?

 

No calmness, equanimity, and detachment thought to befit a philosopher?

 

(Taken from the definitions of Philosophy in The American Heritage Dictionalry of the English Language, 1976 Houghton Mifflin Company, with a "no" infront and a "?" behind.)

 

I do not think you can make a prediction, without a metaphysical concept of an objective reality that will act in a predictable way.

 

Could Einstein have put together a working mathematical model of reality without "thinking" about it?

 

Regards, TAR2

All I said was that relativity makes testable predictions. This distinguishes it from philosophy. It says nothing about attributes they share.

[owl]

swansont:

Each frame of reference yields a different answer. None can be regarded as universally true, i.e. there is no "real" length with all the others being "fake" or illusory. There cannot be, because there is no objective way to determine who is at rest and who is moving.

 

Earth is at rest at one end point of the earth-sun distance. A near ‘C’ frame of reference flying past earth and sun and getting, say, the 1/8 AU measure of that distance, as discussed at length with Cap ‘n R, is not obviously an at rest frame, and “sees” the well established (from at rest frame) length as eight times shorter. If the sun were in fact only 12 million miles away (rather than the 93 million established from the at rest frame) earth would be incinerated, as I argued earlier, with no coherent rebuttal offered. Do you have one now?

 

And I still can’t believe than any intelligent person believes, in the often considered “two rods of equal length” scenario, that making one go fast makes it shorter, and then it gets longer again, equal to its “twin’s” length when it is brought back to the at rest frame side by side.

The “objective” length of the two identical rods stays the same even though the extreme frame change above makes one appear shorter.

I think that soon, the scientific community will look back on the above “length contraction” examples and chuckle at the absurdity which places near light speed frame of reference measurements on equal footing (equally accurate) with at rest frames... resulting in such variable distances between cosmic bodies and such variation in immutably rigid (their objective property) rods.

 

BTW, I did a lot of homework in my last post and asked a few questions, still unanswered; and Cap ‘n R’s apparent contradiction above, which I spelled out in detail, has still not been addressed.

 

Repeating “straw man” is not an answer or even a conversation on the topic.

And the topic here is the philosophical difference between an objective* and a subjective** view of the universe, not a curtain to hide behind, as you suggest I am doing.

* Existing and having properties independent of extremes from which measured, and those properties are best known when seen and measured “up close” from at rest frames.

 

**Having no properties in and of itself independent of extreme frames of measurement.

 

If * then earth stays spherical and never turns into an oblate spheroid... or gets 8 times closer to the sun. If **, it does.

In fact, it doesn’t.

Edited July 16, 2011 by owl

[swansont]

Earth is at rest at one end point of the earth-sun distance. A near ‘C’ frame of reference flying past earth and sun and getting, say, the 1/8 AU measure of that distance, as discussed at length with Cap ‘n R, is not obviously an at rest frame, and “sees” the well established (from at rest frame) length as eight times shorter. If the sun were in fact only 12 million miles away (rather than the 93 million established from the at rest frame) earth would be incinerated, as I argued earlier, with no coherent rebuttal offered. Do you have one now?

 

Because like most of your scenarios this is a straw man description. In the frame that measures the 12 million mile distance, other parameters (like the temperature) will have changed as well. This has been explained to you.

 

And I still can’t believe than any intelligent person believes, in the often considered “two rods of equal length” scenario, that making one go fast makes it shorter, and then it gets longer again, equal to its “twin’s” length when it is brought back to the at rest frame side by side.

The “objective” length of the two identical rods stays the same even though the extreme frame change above makes one appear shorter.

I think that soon, the scientific community will look back on the above “length contraction” examples and chuckle at the absurdity which places near light speed frame of reference measurements on equal footing (equally accurate) with at rest frames... resulting in such variable distances between cosmic bodies and such variation in immutably rigid (their objective property) rods.

 

It's been more than 100 years and industries have been built upon relativistic effects (ever use GPS?). So don't hold your breath. Especially if all you can bring is appeal to ridicule and mockery. That's like bringing a nerf knife to a gun fight.

 

Repeating “straw man” is not an answer or even a conversation on the topic.

 

Misrepresenting the physics and then saying it's wrong isn't a conversation, either. But at least pointing the straw man out gives you a chance to read up on the topic or even ask questions to help you understand. But you haven't really done that.

 

And the topic here is the philosophical difference between an objective* and a subjective** view of the universe, not a curtain to hide behind, as you suggest I am doing.

* Existing and having properties independent of extremes from which measured, and those properties are best known when seen and measured “up close” from at rest frames.

 

**Having no properties in and of itself independent of extreme frames of measurement.

 

If * then earth stays spherical and never turns into an oblate spheroid... or gets 8 times closer to the sun. If **, it does.

In fact, it doesn’t.

I'm still waiting for the objective test one can do to reveal the preferred frame of reference. You can't proceed with the objective description without it.

[DrRocket]

Not necessarily. A relativistic explanation would involve a four-dimensional spacetime which we view three-dimensional sections out of, and different frames of reference necessarily view different three-dimensional sections out of the four-dimensional (immutable) whole.

 

But I'm not a general relativity guy -- ajb would have to make sure I'm talking sense here.

 

General relativity does not in general admit spacelike slices. Such slices, commonly found in discussions of cosmology, are dependent on additional assumptions of homogeneity and isotropy. Those assumptions, the "cosmological principle", permit a decomposition as a one-parameter foliation of spacetime by spacelike hypersurfaces and gives rise to global notions of "time" and "space" that are useful cosmology.

 

However, in general, curved spacetimes need not admit any such decomposition and the very notions of "time" and "space" are only local. There is no universal "reference frame" evenm for a given (local) observer. The notion of a reference frame comes from special relativity, not general relativity. Special relativity itself is seen to be the localization of general relativity, GR on the tangent space at a point.

 

Ultimately in GR one is forced to rely on those quantities that are invariant under the metric tensor, which is locally the Minkowski metric of special relativity. So the basic invariant is the "spacetime interval" (locally) which tranmslates to arc length in the large, and for timelike curves, that arc length is just proper time (times c, which is why it is convenient to choose units so that c=1).

 

What opwl fails, repeatedly, to grasp, is that general relativity embodies the ontology of spacetime, and that no non-mathematical discussion is possible, since the ontology is dependent on an understanding of pseudo-Riemannian manifolds.

[Cap'n Refsmmat]

That's what I get for trying to remember what I read in a popular science book. I suppose it's one of those metaphors which makes everything very much clearer while being wrong in nearly every detail. Thanks for the explanation.

[owl]

swansont:

I'm still waiting for the objective test one can do to reveal the preferred frame of reference. You can't proceed with the objective description without it.

 

I’ll just focus on the distorted earth example, which also applies to an extremely shortened astronomical unit.*

But first, regarding your “explanation”:

*

Because like most of your scenarios this is a straw man description. In the frame that measures the 12 million mile distance, other parameters (like the temperature) will have changed as well. This has been explained to you.

 

So, “for the near ‘C’ traveler,” whizzing by makes the sun cooler “for him?” This is an explanation?

 

We don’t need a test to “know” (philosophy of science, a-priori epistemology section) that earth does not in fact turn into an oblate spheroid... ever... (ignoring the trivial bulging at the equator from eons of spinning.) So, if an extreme frame of reference (not at rest with earth) “sees” earth as such, that is an error of perception/measurement. It is just that simple, although it does require the application of common sense and acknowledgment of the obvious...i.e., that earth stays nearly spherical even while being seen and measured from near 'C' frames of reference.

 

DrRocket:

What owl fails, repeatedly, to grasp, is that general relativity embodies the ontology of spacetime, and that no non-mathematical discussion is possible, since the ontology is dependent on an understanding of pseudo-Riemannian manifolds.

 

The ontology of spacetime is still a hot debate, not a cut and dried established entity as you seem to think (and relativity assumes). I suggest you read my comments and links in my thread on the subject, Spacetime Ontology: the Scholarly Debate, here in the Philosophy section.

 

The pseudo-Riemannian manifolds belong to a specific ontological debate, the background of which I have frequently cited in the Kelly Ross paper on the Ontology and Cosmology of Non-Euclidean Geometry. See also* how math figures into the ontology and meaning of what exists in the real world; and math does not establish what is an actual entity or the meaning of relationships between them. *(Recently quoted above in reply to Cap ‘n R ... that the math is not the meaning, nor does it establish the existence of non-Euclidean manifolds.)

 

Ps re swansont's:

It's been more than 100 years and industries have been built upon relativistic effects (ever use GPS?). So don't hold your breath. Especially if all you can bring is appeal to ridicule and mockery. That's like bringing a nerf knife to a gun fight.

 

I have repeated, over and over, redundantly speaking, that I am not trying to debunk relativity in general. I have repeatedly acknowledged that relativity does a great job of taking into account effects like the fact that clocks tick more slowly at high speed and altered gravitational fields, and so adjustments in GPS clocks can be made to insure accuracy of positioning. Pointing out the absurdity of believing that: seeing/measuring earth as morphed into an oblate spheroid is just as accurate as seeing it as nearly spherical... is not "like bringing a nerf knife to a gun fight," though believing the latter is absurd.

 

(Very slow page changes... my signal/computer or the site, I'm wondering? Also wishing a new, later post would show as a new post in this case, cuz this one is intended to lighten up the discussion while staying true to my argument.)

 

Pop quiz, True or False:

A: Appearances can be deceiving.

 

B:Earth appearing as an oblate spheroid (from high speed frame of reference) is a case of the above.

 

C: Clocks ticking at different rates in orbit than on the surface means that relativity is true in all respects including time dilation and length contraction.

Edited July 18, 2011 by owl

[swansont]

So, “for the near ‘C’ traveler,” whizzing by makes the sun cooler “for him?” This is an explanation?

 

We don’t need a test to “know” (philosophy of science, a-priori epistemology section) that earth does not in fact turn into an oblate spheroid... ever... (ignoring the trivial bulging at the equator from eons of spinning.) So, if an extreme frame of reference (not at rest with earth) “sees” earth as such, that is an error of perception/measurement. It is just that simple, although it does require the application of common sense and acknowledgment of the obvious...i.e., that earth stays nearly spherical even while being seen and measured from near 'C' frames of reference.

 

I guess that's one thing that separates philosophy from science — science requires evidence. Though I doubt philosophy tolerates argument from personal incredulity or appeal to ridicule. Science history is replete with "common sense" being wrong. It was common sense that heat is a substance, or that combustion was due to phlogiston. It was common sense that Galilean transforms were how nature behaved, too. But nature behaves the way nature behaves, common sense be damned.

 

I have repeated, over and over, redundantly speaking, that I am not trying to debunk relativity in general. I have repeatedly acknowledged that relativity does a great job of taking into account effects like the fact that clocks tick more slowly at high speed and altered gravitational fields, and so adjustments in GPS clocks can be made to insure accuracy of positioning. Pointing out the absurdity of believing that: seeing/measuring earth as morphed into an oblate spheroid is just as accurate as seeing it as nearly spherical... is not "like bringing a nerf knife to a gun fight," though believing the latter is absurd.

It's obvious you do not understand relativity, by the way you misrepresent it, and since what you propose is in contradiction with the theory, you are actually insisting that it's wrong. Intentional or not. But since relativity works, you lose.

 

Pop quiz, True or False:

A: Appearances can be deceiving.

 

B:Earth appearing as an oblate spheroid (from high speed frame of reference) is a case of the above.

 

C: Clocks ticking at different rates in orbit than on the surface means that relativity is true in all respects including time dilation and length contraction.

 

What is measured is "reality" for that frame of reference. If you disagree, then what objective test tells us which instrument is correct and which is in error? That's just a restatement of the previous problem that you have not answered.

[owl]

swansont:

What is measured is "reality" for that frame of reference. If you disagree, then what objective test tells us which instrument is correct and which is in error?

That's just a restatement of the previous problem that you have not answered.

 

I agree with the first statement. That is why I started this thread... to illustrate how similar relativity’s insistence that reality depends on frame of reference is to subjective idealism’s insistence that reality depends on subjective perception.

 

The alternative philosophy is realism.

Wikipedia on Philosophical Realism:

Contemporary philosophical realism is the belief that our reality is completely ontologically independent of our conceptual schemes, linguistic practices, beliefs, etc.

In epistemology realism is accounted a subcategory of objectivism.

 

Wikipedia on Objectivity as a philosophy:

Objectivism, in this context, is an alternative name for philosophical realism, the view that there is a reality, or ontological realm of objects and facts, that exists independent of the mind.

 

My argument is that the closer the measurer is to an at rest frame with what is measured, the more accurate the measure ( description of shape of the body, etc.)

 

I thought that I had answered the challenge of your last statement repeatedly. How we know what we know (epistemology) about the size and shape of earth and its distance from the sun comes from more sources than just comparing the extreme, near ‘C’ frame of reference to the at rest frame and claiming they yield equally correct measurements... because relativity claims that everything (reality) is always relative to frame of reference

 

Again, we know that if earth were "objectively" only 12 million miles from the sun it would be incinerated. Saying that “for the high speed traveler,”. the sun is cooler,(or whatever) is subjective idealism. .. that his perception creates an alternative reality... But his perception does not make the sun cooler, or the distance between the two bodies shorter than the standard AU measured from earth, at rest at one end point of the measured distance.

 

Likewise we know from the whole field of earth science that it is a relatively rigid and nearly spherical body. So, to claim that the long belabored extreme frame of reference (likened here to subjective perception/idealism) seeing it as an oblate spheroid is just as accurate as its shape and diameter well known from multiple earth science sources... shows that the near ‘C’ fly-by frame yields a distorted perception and measurement.

 

What objective tests? The orbit of satellites would be radically different if earth were an oblate spheroid. The view of earth from the space station would not see a round (spherical) earth if the extreme frame were an accurate description. Mechanically, we know that earth does not actually flatten out, because we know it is a semi-rigid body. The surface survey which yielded the standardized, earth commensurate meter would have found a different length if earth had a way longer axis length than girth through the equator, or vice-versa. How many more objective tests would it take to establish the “true shape and size” of our planet?

[Cap'n Refsmmat]

Likewise we know from the whole field of earth science that it is a relatively rigid and nearly spherical body.

I dunno; the Earth scientists I asked as they shot past on their rocket were very definite about the Earth being a remarkably oblate spheroid. Apparently it looks like it's been squished in one direction. I can't imagine how you could think the Earth is nearly spherical; it's a tough, rigid body, so stretching it out to a sphere would be impossible. You just can't do that with solid rock.

[StringJunky]

I dunno; the Earth scientists I asked as they shot past on their rocket were very definite about the Earth being a remarkably oblate spheroid. Apparently it looks like it's been squished in one direction. I can't imagine how you could think the Earth is nearly spherical; it's a tough, rigid body, so stretching it out to a sphere would be impossible. You just can't do that with solid rock.

 

Owl

 

If you didn't know Earth was spherical like in our present FOR you would accept the oblate speroid version as the real one as you shot by at some silly fast speed.

 

Thanks Cap'n I've been following this thread and another similar and just could not quite get the not having an 'objective' frame but I think it's sunk in now...there is no preferred frame.

Edited July 19, 2011 by StringJunky

[owl]

I dunno; the Earth scientists I asked as they shot past on their rocket were very definite about the Earth being a remarkably oblate spheroid. Apparently it looks like it's been squished in one direction. I can't imagine how you could think the Earth is nearly spherical; it's a tough, rigid body, so stretching it out to a sphere would be impossible. You just can't do that with solid rock.

Do you think there is any way to reconcile your imaginary high speed scientists' view of earth with the centuries of knowledge about the spherical earth since early inhabitants thought it was flat? Of course the latter were only reporting what they "saw" from local surface observation as a "frame of reference" like your imaginary high speed voyagers.

Edited July 20, 2011 by owl

[Cap'n Refsmmat]

Do you think there is any way to reconcile your imaginary high speed scientists' view of earth with the centuries of knowledge about the spherical earth since early inhabitants thought it was flat? Of course the latter were only reporting what they "saw" from local surface observation as a "frame of reference" like your imaginary high speed voyagers.

What do you mean? They had plenty of time to make observations, perform experiments, use radar and laser measurement technology, and pull every trick in the book. The Earth is definitely a flattened oblate spheroid. I don't know why you think that centuries of knowledge are relevant; we had centuries of knowledge of miasmas and bad airs causing tuberculosis, and we all know how that worked out.

[owl]

What do you mean? They had plenty of time to make observations, perform experiments, use radar and laser measurement technology, and pull every trick in the book. The Earth is definitely a flattened oblate spheroid. I don't know why you think that centuries of knowledge are relevant; we had centuries of knowledge of miasmas and bad airs causing tuberculosis, and we all know how that worked out.

What a kidder! Frame of reference defines reality. Flat earth?... A legitimate frame of reference, empirical, reporting what is seen.

Only it isn't flat, it turns out.

 

Oblate spheroid earth?... A legitimate frame of reference, etc., as above. But you must be flying by at near 'C' to "see" it that way. (Or have your head in the sand... something unusual at least... the lighter side!)

Only it always stays nearly spherical according to all other perspectives, both post renaissance and modern, so why does the imaginary space cadet get credit for equality of measurement?

Are flat earth'ers due equal credit?... or has science shown them wrong?

(Grammar edit.)

Edited July 20, 2011 by owl

[Cap'n Refsmmat]

What a kidder! Frame of reference defines reality. Flat earth?... A legitimate frame of reference, empirical, reporting what is seen.

Only it isn't flat, it turns out.

There's no inertial frame of reference for which the Earth is a flat surface. No velocity will achieve that, just like no reference frame includes a circular, flat Earth on the backs of four elephants which walk on top of a giant space turtle.

 

Oblate spheroid earth?... A legitimate frame of reference, etc., as above. But you must be flying by at near 'C' to "see" it that way. (Or have your head in the sand... something unusual at least... the lighter side!)

Don't be silly. They're not flying at c, they're stationary. It's just that the Earth is moving particularly fast in their general direction. They're stationary, so it's their measurements that make sense, not ours. How could you propose we rely on measurements taken on Earth when Earth is moving so fast?

 

Only it always stays nearly spherical according to all other perspectives, both post renaissance and modern, so why does the imaginary space cadet get credit for equality of measurement?

If we consider the space of velocities and directions I may travel in, very few possibilities have a spherical Earth. The majority of situations, if you chose randomly, would have an observer traveling at a significant fraction of light speed compared to Earth. Face it: you're outnumbered by hypothetical observers.

[DrRocket]

I dunno; the Earth scientists I asked as they shot past on their rocket were very definite about the Earth being a remarkably oblate spheroid. Apparently it looks like it's been squished in one direction. I can't imagine how you could think the Earth is nearly spherical; it's a tough, rigid body, so stretching it out to a sphere would be impossible. You just can't do that with solid rock.

 

Actually a sphere passing by at relativistic speeds LOOKS LIKE a sphere. The flattening is not observed, due to the finite speed of light. There is a big difference between the actual dimensions and what would be seen by an eye or a camera. This effect was first noticed by Roger Penrose, and you can find a discussion in his book The Road to Reality (highly recommended).

 

On the other hand, an actual measurement, could it be performed, would show the sphere to be highly oblate. Appearances can be deceiving.

[Cap'n Refsmmat]

Actually a sphere passing by at relativistic speeds LOOKS LIKE a sphere. The flattening is not observed, due to the finite speed of light. There is a big difference between the actual dimensions and what would be seen by an eye or a camera. This effect was first noticed by Roger Penrose, and you can find a discussion in his book The Road to Reality (highly recommended).

 

On the other hand, an actual measurement, could it be performed, would show the sphere to be highly oblate. Appearances can be deceiving.

Yes, I'd forgotten about that for a moment, but I'm assuming the scientists on their rocket ship are decently competent physicists. The relativistic Doppler effect would certainly make Earth look rather strange as well.

 

A couple months ago I started an online relativity simulator with another SFN member. I should get back to working on that. It could be useful for discussions like this.

[swansont]

My argument is that the closer the measurer is to an at rest frame with what is measured, the more accurate the measure ( description of shape of the body, etc.)

 

That would appear to be contradictory to there being no preferred frame. What if you are measuring a distance between objects and there is no rest frame?

 

Again, we know that if earth were "objectively" only 12 million miles from the sun it would be incinerated. Saying that “for the high speed traveler,”. the sun is cooler,(or whatever) is subjective idealism. .. that his perception creates an alternative reality... But his perception does not make the sun cooler, or the distance between the two bodies shorter than the standard AU measured from earth, at rest at one end point of the measured distance.

 

No, we don't know this. You state it as if it were a fact, but you are just asserting it. You just agreed that measurement is reality for that frame. Now you are claiming he opposite. If I measure the temperature and using the same method I get differing answers in different frames, how do I tell which one is right?

 

What objective tests? The orbit of satellites would be radically different if earth were an oblate spheroid. The view of earth from the space station would not see a round (spherical) earth if the extreme frame were an accurate description. Mechanically, we know that earth does not actually flatten out, because we know it is a semi-rigid body. The surface survey which yielded the standardized, earth commensurate meter would have found a different length if earth had a way longer axis length than girth through the equator, or vice-versa. How many more objective tests would it take to establish the “true shape and size” of our planet?

In the frame of the fast rocket, yes they would be radically different, just as the shape of the earth is radically different. But you you can't hop between frames and mix up measurements and quantities (unless they are invariant)

[owl]

Cap ;n R:

If we consider the space of velocities and directions I may travel in, very few possibilities have a spherical Earth. The majority of situations, if you chose randomly, would have an observer traveling at a significant fraction of light speed compared to Earth. Face it: you're outnumbered by hypothetical observers.

 

Well, hypothetical fairies could outnumber humans too, depending on who is imagining them.

(But this is tongue in cheek; I do get your point.)

 

But seriously...This thread is offered as philosophy of science and focused on relativity’s “frame of reference” as very much like the “subject” in subjective idealism. The latter claims that there is no “objective reality,” but rather that whatever anyone perceives *is reality* "for him." The “for him” is like the “for a photon” frame of reference (there is no distance between earth and sun or travel time) or “for the above high speed scientists,” earth is an oblate spheroid.

 

Philosophical realism, on the other hand, claims that earth is as it is independent of subjective or extreme frame of reference perception... that the many possible variations in how it appears are due to perceptual variation rather than earth itself varying in shape, etc.

That, of course still leaves the question, “What is its actual, objective shape (and size?)" If you claim that we can not know that because of perceptual and frame of reference variation (with “no preferred frame of reference) then we can say, as above, that the flat earth perception (a local "frame" not about relativistic effects, of course) is just as accurate as the spherical earth later confirmed by science,... but now again debunked (?) by the oblate spheroid earth as seen from near ‘C’ perspective...

and there is no “objective reality/cosmos”, cuz it all depends on perception.

 

This puts relativity’s length contraction squarely in the camp of subjective idealism.

If you say, “OK, so what?”, I’ll just rest my case, and accept that relativity theorists believe that science can never know the actual properties (shape, size, etc.) of earth, let alone anything else, like the “actual length” of a meter rod.

I'll repeat that it seems reasonable to assume that the at rest frame with what is perceived/measured will yield the accurate measurement/description, not the frame flying by at near light speed (or the imaginary earth flying by a stationary point at near 'C'.)

Edited July 20, 2011 by owl

[Cap'n Refsmmat]

The key point against relativity being a form of subjective idealism is that observations in any reference frame can be transformed into observations from another frame using a predictable and consistent mathematical formula. I can determine exactly what should be observed in any reference frame if I know what I observe in mine. That's hardly subjective.

[owl]

The key point against relativity being a form of subjective idealism is that observations in any reference frame can be transformed into observations from another frame using a predictable and consistent mathematical formula. I can determine exactly what should be observed in any reference frame if I know what I observe in mine. That's hardly subjective.

Now we are making progress in communication. I have often/repeatedly credited relativity with the above, which is why I am not about debunking relativity in general. Yes, its formulae keep us all on the same page for accurate GPS positioning too, even while relativity effects make clocks go bonkers.

 

Likewise we can take the squished earth as seen from high velocity, apply the Lorenz transformation formula and transform the squished earth back to its "actual" shape in the real/objective world... Right?

 

(Or is the squished earth still just as real as the spherical one, as a subjective idealist on the spaceship would say?)

 

I'm betting you say "wrong," and continue to insist that the squished earth is just as accurate a description as the spherical one we all know and love!

[Cap'n Refsmmat]

I'm betting you say "wrong," and continue to insist that the squished earth is just as accurate a description as the spherical one we all know and love!

Well, it is.

 

But I can take the squished Earth and use the relative velocity between Earth and observer to calculate what an observer sitting on Earth would see, and I would calculate that he'd see something very nearly spherical.

[DrRocket]

Well, it is.

 

But I can ...calculate ....

 

And therein lies the difference between you and owl.