Spacetime Ontology, the Scholarly Debate

[owl]

A link provided by notimeforspacetime in the Ontology of Time thread (Speculations) has prompted a return to this thread.

http://www.physorg.com/news/2011-04-scientists-spacetime-dimension.html

Here a some interesting quotes from a paper by Lisa Zyga (my bold):

In other words, what experimentally exists are the motion of an object and the tick of a clock, and we compare the object’s motion to the tick of a clock to measure the object’s frequency, speed, etc. By itself, t has only a mathematical value, and no primary physical existence.

 

The point of view which considers time to be a physical entity in which material changes occur is here replaced with a more convenient view of time being merely the numerical order of material change.

Sorli:

Einstein said, "Time has no independent existence apart from the order of events by which we measure it." Time is exactly the order of events: this is my conclusion.

Sorli:

In this 3D space there is no ‘length contraction,’ there is no ‘time dilation.’ What really exists is that the velocity of material change is ‘relative’ in the Einstein sense.”

Edited June 14, 2011 by owl

[owl]

From my post 24 in the Frame of reference (philosophy) thread;

The question went unanswered, but it belongs here:

 

Why introduce the elusive medium spacetime and insist that gravity curves it and then planets are guided around in their orbits by spacetime rather than by the pull of gravity without an unidentified medium.

Why doesn’t the principle of Occam’s razor cut spacetime out and let gravity be the attractive force of mass without the unnecessary medium/concept/whatever, spacetime?

[owl]

Bump.

[swansont]

Why introduce the elusive medium spacetime and insist that gravity curves it and then planets are guided around in their orbits by spacetime rather than by the pull of gravity without an unidentified medium.

Why doesn’t the principle of Occam’s razor cut spacetime out and let gravity be the attractive force of mass without the unnecessary medium/concept/whatever, spacetime?

 

Because it works better than the previous description at describing how things behave. Occam's razor is predicated on all things being equal. Here things are not equal, thus it does not apply.

[owl]

Because it works better than the previous description at describing how things behave. Occam's razor is predicated on all things being equal. Here things are not equal, thus it does not apply.

Could you give me an example of "how things behave" (say Mercury orbiting the sun... a classic relativity success story) with "spacetime" being curved in contrast to the mutual gravitation between the two bodies without the curved medium, spacetime? What does spacetime curvature add to gravity between them without it?

[swansont]

Could you give me an example of "how things behave" (say Mercury orbiting the sun... a classic relativity success story) with "spacetime" being curved in contrast to the mutual gravitation between the two bodies without the curved medium, spacetime? What does spacetime curvature add to gravity between them without it?

Newtonian gravity doesn't explain the precession of the perihelion of Mercury, GR does. There's also the deflection of light, gravitational redshift, gravitational lensing, Shapiro delay, Frame dragging and the expansion of the universe. GR is a geometrical description.

 

http://en.wikipedia.org/wiki/Tests_of_general_relativity

[owl]

Swansont lists the most often quoted successes of relativity theory above without addressing exactly how "spacetime" is a necessary element.

So, I hope to kick-start this thread again by repeating some quotes from the thread which were never addressed.

me:

I have quoted in this thread comments by Brown to the effect that spacetime does not exist and further, that Minkowski's concept of it was "parasitic" upon the intrinsic dynamics of the physical entities and their relationships.

 

(I've edited “space” to “spacetime” for more general application... my quote):

Ontologically, to have the property of curvature, spacetime must be some kind of extant entity. I and many others argue that it is not. That is my "beef" with the reification of spacetime in relativity.

 

From the Brown and Pooley paper:,"Minkowski’s spacetime: a glorious non-entity":

(Abstract)

It is argued that Minkowski space-time cannot serve as the deep structure within a “constructive” version of the special theory of relativity, contrary to widespread opinion in the philosophical community.

me:

... in contrast to constructive-theory explanations, such a principle-theory explanation will (B&P) “have nothing to say about the

reality behind the phenomenon.” (2003, 331).

Brown quoting Einstein:

“It seems to me . . . that a physical theory can be satisfactory only

when it builds up its structures from elementary foundations." (Ein-

stein, 1993)12

“. . . when we say we have succeeded in understanding a group of

natural processes, we invariably mean that a constructive theory has

been found which covers the processes in question.” (Einstein, 1982,

228)

me:

A theory which has "nothing to say about the reality behind the phenomenon” does not, of course, address the ontology of spacetime. I agree with Einstein's statements above and have been pursuing those "elementary foundations" in the context of spacetime ontology.

 

Deeper into the text is the following Einsteinian perspective from Brown:

We have seen that for Einstein the inertial property of matter requires explanation in terms of the action of a real entity on the particles. It is the space-time connection that plays this role: ... geodesics form ruts or grooves in spacetime that guide the free particles along their way.

 

me (again): “Ruts or grooves in what?”

[owl]

A process question for admin:

What is the point of the popularity rating function here by which I get another demerit for the above post quoting and commenting on ontological criticisms, the thread topic?

The more I question mainstream time dilation, length contraction, and the nature of spacetime, the more demerits I get. What part of science is a popularity contest?

[swansont]

A process question for admin:

What is the point of the popularity rating function here by which I get another demerit for the above post quoting and commenting on ontological criticisms, the thread topic?

The more I question mainstream time dilation, length contraction, and the nature of spacetime, the more demerits I get. What part of science is a popularity contest?

 

I doubt it has anything to do with popularity at all, it's directly tied into the quality of argument. You criticized me for not addressing something that wasn't part of the post to which I was responding: You asked what spacetime curvature adds to the mix. I answered that. Using logical fallacies (moving the goal posts) might be what got you a demerit.

 

You want positive points? Make better posts.

[owl]

swansont:

 

You want positive points? Make better posts.

 

No, I don't "want positive points." I wanted to (and did) criticize a "social network site" type popularity rating in a science site.

 

How was my post bad, other than the obvious jugement from your bias, that you don't like ontological criticism of spacetime, even by well credentialed experts in the field?

[swansont]

swansont:

 

 

 

No, I don't "want positive points." I wanted to (and did) criticize a "social network site" type popularity rating in a science site.

 

How was my post bad, other than the obvious jugement from your bias, that you don't like ontological criticism of spacetime, even by well credentialed experts in the field?

 

Logical fallacies are logical fallacies. Bias doesn't enter into it.

[owl]

Logical fallacies are logical fallacies. Bias doesn't enter into it.

In a real conversation or debate, the argument that I am presenting logical fallacies would require some specifics about what makes my argument fallacious. You seem to like the cryptic answer without addressing the above at all. It's your choice but it is empty of substance.

You clearly dislike ontological criticism of spacetime, and have totally dodged all arguments of that nature in this thread. If that is not bias, what else can it be called, and still be civil?

[swansont]

In a real conversation or debate, the argument that I am presenting logical fallacies would require some specifics about what makes my argument fallacious. You seem to like the cryptic answer without addressing the above at all. It's your choice but it is empty of substance.

What part of my post (#59) do I need to clarify? Or did you just not read it?

[owl]

from my post 57:

Swansont lists the most often quoted successes of relativity theory above without addressing exactly how "spacetime" is a necessary element.

 

swansont, post 59:

I doubt it has anything to do with popularity at all, it's directly tied into the quality of argument. You criticized me for not addressing something that wasn't part of the post to which I was responding: You asked what spacetime curvature adds to the mix. I answered that. Using logical fallacies (moving the goal posts) might be what got you a demerit.

 

You want positive points? Make better posts.

 

How did you answer what spacetime curvature adds to the mix?

The spacetime- critical quotes in this thread do not attempt to debunk relativity in general, but rather question the nature of (ontology) and need for (Occam’s razor) spacetime to make those “successes” you listed work.

 

You said in post 56:

Newtonian gravity doesn't explain the precession of the perihelion of Mercury, GR does.

 

What part of spacetime curvature is required for the improved description of the above provided by GR. In other words, first (always), what IS spacetime, then how is spacetime curvature essential to GR?

I know that all explanations of GR open with the assertion that mass curves “spacetime.” None, that I know of start with a consensus on what it IS. (The International Society for the Advanced Study of Spacetime has still not arrived at such a consensus after a decade of conferences and reams of papers on it.)

 

The quoted critics in this thread (and many, many more, as above) ask, what is this stuff, spacetime supposed to be, that “it” is curved by mass.

 

We know that gravity is some kind of pull between masses that makes, among other things, planets orbit the sun and light’s path get bent around masses, i.e., it acts as if it has mass.

You said, “

“GR is a geometrical description.”

 

No doubt... a system of coordinates for tracking and predicting the movements of particles/bodies through space over time. No problem. GR does it well. But what IS spacetime in all of that, that “it” is a malleable medium rather than just a system of coordinates?

This is the topic of this thread. How about addressing it for a change?

Ps; One, "for instance" among many: The "frame dragging" you mention as a curved spacetime confirmation can easily be explained by earth's topographical and crust density irregularities (not a smooth surface), which complicate the orbital positions of satellites... usually attributed to "frame dragging." (Spinning black hole "frame dragging" lacks enough evidence... re: the way stuff is sucked in... to be such a confirmation.)

Edited August 3, 2011 by owl

[swansont]

What part of spacetime curvature is required for the improved description of the above provided by GR. In other words, first (always), what IS spacetime, then how is spacetime curvature essential to GR?

 

Spacetime is the spatial and time coordinates we use to describe events and phenomena, but the existence of coordinate systems using space and time are not exclusive to relativity. In GR this geometry is curved. That's the qualitative essence of the theory: mass and energy warp spacetime.

 

I know that all explanations of GR open with the assertion that mass curves “spacetime.” None, that I know of start with a consensus on what it IS. (The International Society for the Advanced Study of Spacetime has still not arrived at such a consensus after a decade of conferences and reams of papers on it.)

 

…

 

No doubt... a system of coordinates for tracking and predicting the movements of particles/bodies through space over time. No problem. GR does it well.

 

So you seem to acknowledge that the question of how curvature is essential to the theory — what it — has been answered.

 

What you claim is unanswered — what IS spacetime — wasn't in your post (post 55). Got that? You didn't ask that question. Which is why complaining that it wasn't answered is moving the goalposts, a logical fallacy. As I have already explained. Complaining about something you said in post 57 doesn't wash when we're discussing something I posted before that. I do not feel compelled to be held responsible for reading your mind.

 

You are now free to apologized for the false accusation.

[owl]

Swansont:

You are now free to apologized for the false accusation.

 

I will be glad to if I can find out if I did in fact make a false accusation.

This will require a detailed review of the posts in question. Here goes. (Bold added)

my post 55 :

Could you give me an example of "how things behave" (say Mercury orbiting the sun... a classic relativity success story) with "spacetime" being curved in contrast to the mutual gravitation between the two bodies without the curved medium, spacetime? What does spacetime curvature add to gravity between them without it?

 

I agree that I did not (obviously) ask specifically "What is spacetime?" in the above post.

 

swansont post 56:

Newtonian gravity doesn't explain the precession of the perihelion of Mercury, GR does. There's also the deflection of light, gravitational redshift, gravitational lensing, Shapiro delay, Frame dragging and the expansion of the universe. GR is a geometrical description.

 

“GR does” how with spacetime curved as compared to without curved spacetime? Not answered.

 

me in 57: “Swansont lists the most often quoted successes of relativity theory above without addressing exactly how "spacetime" is a necessary element.

 

my repeat quote in post 57:

Ontologically, to have the property of curvature, spacetime must be some kind of extant entity. I and many others argue that it is not. That is my "beef" with the reification of spacetime in relativity.

 

swansont in post 59:

You asked what spacetime curvature adds to the mix. I answered that.

Again, you answered that "GR does", not how curved spacetime is essential to how it does.

 

me in 64:

What part of spacetime curvature is required for the improved description of the above provided by GR? In other words, first (always), what IS spacetime, then how is spacetime curvature essential to GR?

 

Here, the question in dispute, "what IS spacetime" appears as an "in other words" to clarify the repeated question above it, which you still have not answered. Ontologically, if one claims that spacetime curvature is essential to those quoted successes of GR, it would be essential to establish what spacetime IS, as "it" manifests the property of curvature.

 

swansont post 65:

Spacetime is the spatial and time coordinates we use to describe events and phenomena...

That's the qualitative essence of the theory: mass and energy warp spacetime.

 

So our spatiotemporal coordinates get warped, as distinguished from an existing malleable medium getting warped by mass? Is that kind of a mind warp or what?... (a little humor, very little maybe, but essentially an honest question.)

...mass and energy warp what?... the essential ontological question presented in this thread.

 

swansont, post 65:

What you claim is unanswered — what IS spacetime — wasn't in your post (post 55). Got that? You didn't ask that question. Which is why complaining that it wasn't answered is moving the goalposts, a logical fallacy.

Got it. It was a later "in other words" to clarify my question in post 55. Should I apologize for the attempt at clarification. OK, sorry.

 

Now, do you want to continue to whip me over our differences in the significance of the above dispute (a technical detail point for you as I see it) or are you interested in addressing the thread topic, starting with the unanswered questions immediately above?

Edited August 4, 2011 by owl

[swansont]

Got it. It was a later "in other words" to clarify my question in post 55. Should I apologize for the attempt at clarification. OK, sorry.

 

Sarcasm noted. No, the apology was for accusing me of not explaining what made your argument fallacious, when I did.

 

Now, do you want to continue to whip me over our differences in the significance of the above dispute (a technical detail point for you as I see it) or are you interested in addressing the thread topic, starting with the unanswered questions immediately above?

 

Not at all interested in the ontology, as I've explained several times before. But you keep insisting on non-ontological points that are either unsubstantiated or untrue, and in doing so, misrepresenting relativity. That, I'm interested in.

[owl]

swansont:

Sarcasm noted. No, the apology was for accusing me of not explaining what made your argument fallacious, when I did.

 

How, again, did you explain what made my argument fallacious? By citing the usual success stories of GR and saying, "GR does."? It was the ontology of spacetime being curved by mass and energy that I was questioning. Is it as mental matrix, a spatiotemporal coordinate system of math/geometry model only being warped or some medium without which masses can not pull on other masses.

I don't think you know what ontology is yet. At least you have no interest in it as you said:

Not at all interested in the ontology, as I've explained several times before.

 

And since that is what this thread is about... ???

 

But you keep insisting on non-ontological points that are either unsubstantiated or untrue, and in doing so, misrepresenting relativity. That, I'm interested in.

 

Specifically what non-ontological points?... or do you not do specifics? 'GR says so' is not specific. And "frame dragging" (for just one instance from your list) is not a confirmation of malleable spacetime, as I specifically argued above... But, as usual, no reply to specific arguments.

 

You have not replied to any of the quotes in this thread which actually criticize the usual assumptions in the relativity community about the nature of spacetime.

 

I wish I could appeal to a moderator about all of the above, but you are it, and you are not an unbiased, objective scientist in this field of inquiry.

[mississippichem]

I wish I could appeal to a moderator about all of the above, but you are it, and you are not an unbiased, objective scientist in this field of inquiry.

 

There are many moderators to appeal to. However, I doubt you will get anywhere as swansont has not violated a rule and is not currently acting as a moderator in this thread as he is posting as a "poster".

 

He is simply calling you on it every time you misrepresent the established science of relativity. No rule violation there, just good debate.

[imatfaal]

Specifically what non-ontological points?... or do you not do specifics? 'GR says so' is not specific. And "frame dragging" (for just one instance from your list) is not a confirmation of malleable spacetime, as I specifically argued above... But, as usual, no reply to specific arguments.

 

Ps; One, "for instance" among many: The "frame dragging" you mention as a curved spacetime confirmation can easily be explained by earth's topographical and crust density irregularities (not a smooth surface), which complicate the orbital positions of satellites... usually attributed to "frame dragging." (Spinning black hole "frame dragging" lacks enough evidence... re: the way stuff is sucked in... to be such a confirmation.)

 

Do you have a references detailing how the non-uniformity of the earth can explain frame dragging? I will be interested in the experimental confirmation of frame-dragging around the earth which ties in with the notion it is caused by "earth's topographical and crust density irregularities".

 

I presume that the same paper will explain a new alternative method of formation of the relativistic jets observed around black holes (and possible neutron stars), which is presently explained using the (now debunked in your eyes) Lense-Thirring effect. As blackholes and neutron stars are the smoothest and homogeneous things about, it is interesting to speculate how surface and crustal irregularities explain observed phenomena.

 

 

I wish I could appeal to a moderator about all of the above, but you are it, and you are not an unbiased, objective scientist in this field of inquiry.

SonT and the other mods deserve better than this sort of slur.

[owl]

Do you have a references detailing how the non-uniformity of the earth can explain frame dragging? I will be interested in the experimental confirmation of frame-dragging around the earth which ties in with the notion it is caused by "earth's topographical and crust density irregularities".

 

I presume that the same paper will explain a new alternative method of formation of the relativistic jets observed around black holes (and possible neutron stars), which is presently explained using the (now debunked in your eyes) Lense-Thirring effect. As blackholes and neutron stars are the smoothest and homogeneous things about, it is interesting to speculate how surface and crustal irregularities explain observed phenomena.

 

SonT and the other mods deserve better than this sort of slur.

It was quite a few years ago that I researched the alternative explanation (above) to frame dragging as a "twist" in the supposed* malleable medium, "spacetime."

I'll have to go back and dig it up again if you insist... after the weekend.

*Meanwhile, I have cited a few experts in this thread who are very critical of the usual assumptions about spacetime as a malleable medium. (Also see my reply today in the ontology of time thread.)

 

Swansont has said that he has no interest in ontology. That qualifies as a bias against the subject matter of this thread. I called him on that bias... not a personal "slur."

[imatfaal]

It was quite a few years ago that I researched the alternative explanation (above) to frame dragging as a "twist" in the supposed* malleable medium, "spacetime."

I'll have to go back and dig it up again if you insist... after the weekend.

*Meanwhile, I have cited a few experts in this thread who are very critical of the usual assumptions about spacetime as a malleable medium. (Also see my reply today in the ontology of time thread.)

To be clear - that's a no. I understand you have cited experts in earlier sections - but you were claiming a lack of attention to specific arguments, this was one of them that you highlighted - is there no basis for it?

 

Swansont has said that he has no interest in ontology. That qualifies as a bias against the subject matter of this thread. I called him on that bias... not a personal "slur."

I disagree; to claim that uninterest implies a lack of disinterest is a slur - especially when directed at a scientist.

[DrRocket]

In a real conversation or debate, the argument that I am presenting logical fallacies would require some specifics about what makes my argument fallacious. You seem to like the cryptic answer without addressing the above at all. It's your choice but it is empty of substance.

You clearly dislike ontological criticism of spacetime, and have totally dodged all arguments of that nature in this thread. If that is not bias, what else can it be called, and still be civil?

 

You argue about a theory, general relativity, of which you have not the slightest understanding. Hence your posts are non sequiturs. Before you can sensibly either support or criticize a theory you must first understand it. Then you can decide whether or not to accept it.

 

But when you attempt to discuss something about which you are clueless, such as "curvature" (which is in fact a rather technical and subtle concept) you wind up just babbling. You cannot hope to eschew mathematics and then intelligently discuss an inherently mathematical subject.

 

There is a reason that general relativity and quantum field theory are not taught in kindergarten.

[owl]

You argue about a theory, general relativity, of which you have not the slightest understanding. Hence your posts are non sequiturs. Before you can sensibly either support or criticize a theory you must first understand it. Then you can decide whether or not to accept it.

 

But when you attempt to discuss something about which you are clueless, such as "curvature" (which is in fact a rather technical and subtle concept) you wind up just babbling. You cannot hope to eschew mathematics and then intelligently discuss an inherently mathematical subject.

 

There is a reason that general relativity and quantum field theory are not taught in kindergarten.

 

Math requires referents in the “real world” to be meaningful. (2+2=4, but what the numbers stand for introduces ontology.

2 apples plus 2 oranges = 4 fruits, actual but different entities.) So the math plus the referents equals a meaningful statement.

 

I have quoted Kelley Ross in this thread on that point, including what “intrinsic vs extrinsic curvature” applied to different “manifoldes” means in the real world, what a fourth spatial dimension might mean (or not), etc.... what spacetime IS, if anything besides a coordinate system for things traveling through space over time.

 

A superior attitude based on math expertise does not address the ontology of space, time or spacetime. This point seems to totally elude you.

[Cap'n Refsmmat]

A superior attitude based on math expertise does not address the ontology of space, time or spacetime.

Nor does an incorrect understanding of the physics of space, time, or spacetime.