Ontology of time

[owl]

One can use spacetime intervals without assuming spacetime "exists." Simply use [math]s^2 = \Delta x^2 - c^2 \Delta t^2[/math] and pretend s means something else.

 

Regardless, you have been arguing against relativity without understanding it. I have been explaining its predictions. These predictions explain the results of experiments very well. If you want to come up with your own hypotheses:

 

 

...you had better come up with evidence to support them. How do you account for observed time dilation and length contraction?

 

Regarding "pretending s means something else..." Yes, I suggested here awhile back that that the equations use "mm" for mystery medium rather than asserting spacetime as an entity, a "malleable medium." (But "mm" could then be mistaken for the latter. Better use "w" for "whatever.")

 

I have not been arguing with relativity's predictions but rather with its attribution of substance, or whatever, to some medium (spacetime) that gets curved by mass/energy. That is the ontological issue.

If "it" is just a coordinate system for tracking and predicting stuff moving through space (which can remain empty volume) over time (event duration as objects move from A to B)... then *what gets warped*? The above is the map, not the territory.

 

What do you see as the fallacy/error in my hypotheses you just quoted above? What about the volume (space) in which things exist and move and the time it takes them to move make "spacetime" curve under the influence of mass/energy?

Brown and Pooley's paper (see my spacetime thread, "Minkowski's spacetime: a glorious non-entity") asserts that spacetime does not exist, and that all predictions of relativity are based on the interactions among these masses, with "spacetime" being "parasitic" upon these actual entities. Einstein himself said that, without mass/energy, spacetime would not exist. So where does that leave it as something (?) that mass curves? That is the ontological question.

 

I account for "time dilation" by defining time as event duration of physical processes (EDPP) and then sticking to the empirical, observed processes in question, like the variable rate of ticking in clocks, not assuming that "time itself" (what is that?) slows down.

 

I am still struggling with length contraction, especially since you cited references indicating that optical distortion is not an option. (I will need to study the "proof" of that in depth before I accept it as factual.)

Also, since DrRocket pointed out that there is no experimental verification of large scale length contraction beyond the sub-atomic level, (particle physics is very complex with lots of room for error) it still seems to me that the "burden of proof" for rods and earth and astronomical distances "contracting" is still on those who claim there is such evidence, as you seem to do.

 

So far the best I can do is appeal to realism vs the version of idealism that claims that the description of rigid/solid objects depends on frame of reference, leaving "intrinsic properties of objects" (as in realism) in the dust in favor of frames of reference defining all objects' shapes and measures.

 

So, the question "What shape is earth?' then depends on how you look at it, as if it had no shape of its own... just like idealism, which I find an absurd philosophy.

I think that relativity claims that we can not know the shape of earth (or the "actual distance") to the sun, and that this makes a mockery of science.

For all of the above reasons, I think philosophy of science is very relevant to the epistemology of what we know and how we know it.

 

swansont:

I was under the impression that you were interested in what time "is" rather than contending that it does not exist. If time and spatial dimensions exist, you have spacetime.

 

See above... also way above, like, read the thread. You criticize me for lots of repetition and then you ask this question, which I have answered dozens of times.

I again defined time above (EDPP.) In what sense do you think EDPP exists as something that "dilates." How is "clocks tick more slowly..." not a sufficient description?

I have posted a lot (in the spacetime thread) on the ontology of non-euclidean geometry, which claims reality for various conceptual "manifolds" and attributes "curvature" to "spacetime" in the process.

 

For me, space remains 3-D volume, which is empty space in between (and within) *things* which occupy space.

So, with the above as background, there is nothing to be curved. There is no combining event duration (elapsed time, not a "thing") with empty volume (not a "thing") which establishes spacetime as "whatever" with curvature. "Ruts or grooves" in what guide objects in their curved paths. But that is ontology, which does not interest you.

[Cap'n Refsmmat]

I have not been arguing with relativity's predictions but rather with its attribution of substance, or whatever, to some medium (spacetime) that gets curved by mass/energy. That is the ontological issue.

No, you've been arguing that length contraction doesn't exist and that there are certain preferred reference frames.

 

Incidentally, the spacetime that gets curved is a part of general relativity, not special relativity, and explains gravity, not time dilation or length contraction. No curvature is required for length contraction and time dilation. No "thing" must be curved.

[swansont]

Regarding "pretending s means something else..." Yes, I suggested here awhile back that that the equations use "mm" for mystery medium rather than asserting spacetime as an entity, a "malleable medium." (But "mm" could then be mistaken for the latter. Better use "w" for "whatever.")

 

<Sigh>

 

Nobody has claimed it was a medium. In fact, Cap'n just said to not worry about that distinction. It's a coordinate system. 3 spatial and one time dimension.

 

 

I have not been arguing with relativity's predictions but rather with its attribution of substance, or whatever, to some medium (spacetime) that gets curved by mass/energy. That is the ontological issue.

 

If "it" is just a coordinate system for tracking and predicting stuff moving through space (which can remain empty volume) over time (event duration as objects move from A to B)... then *what gets warped*? The above is the map, not the territory.

 

You are the one giving the attribution of substance, in order to denounce it. That's called a straw man argument.

 

The distinction is reminiscent to that between a map and a globe. The shortest distance between points is not a straight line on a map. The geometry that describes space and time is not flat. Light travels along a geodesic rather than a straight line.

 

Also, since DrRocket pointed out that there is no experimental verification of large scale length contraction beyond the sub-atomic level, (particle physics is very complex with lots of room for error) it still seems to me that the "burden of proof" for rods and earth and astronomical distances "contracting" is still on those who claim there is such evidence, as you seem to do.

 

Lots of room for error? No, not so much.

 

So far the best I can do is appeal to realism vs the version of idealism that claims that the description of rigid/solid objects depends on frame of reference, leaving "intrinsic properties of objects" (as in realism) in the dust in favor of frames of reference defining all objects' shapes and measures.

 

No physical tests at all (your realism) leaves a lot more room for error than empirical science.

 

So, the question "What shape is earth?' then depends on how you look at it, as if it had no shape of its own... just like idealism, which I find an absurd philosophy.

I think that relativity claims that we can not know the shape of earth (or the "actual distance") to the sun, and that this makes a mockery of science.

For all of the above reasons, I think philosophy of science is very relevant to the epistemology of what we know and how we know it.

 

Once again, you state something which is not claimed. Relativity does not say we can't know the shape of the earth. It says that the answer you get will depend on the frame of reference you are in. There is no universally true answer to that of length (or time).

 

swansont:

 

 

See above... also way above, like, read the thread. You criticize me for lots of repetition and then you ask this question, which I have answered dozens of times.

I again defined time above (EDPP.) In what sense do you think EDPP exists as something that "dilates." How is "clocks tick more slowly..." not a sufficient description?

I have posted a lot (in the spacetime thread) on the ontology of non-euclidean geometry, which claims reality for various conceptual "manifolds" and attributes "curvature" to "spacetime" in the process.

 

I didn't ask for your definition. I asked you to confirm that you agree that you are not claiming that time doesn't exist. Since you have given a definition several times it would seem the answer is that you are not, but then you say you don't accept spacetime. You can't have it both ways. If space and time don't exist, why does time need a definition?

 

For me, space remains 3-D volume, which is empty space in between (and within) *things* which occupy space.

So, with the above as background, there is nothing to be curved. There is no combining event duration (elapsed time, not a "thing") with empty volume (not a "thing") which establishes spacetime as "whatever" with curvature. "Ruts or grooves" in what guide objects in their curved paths. But that is ontology, which does not interest you.

 

Non-Euclidean coordinate systems don't exist?

[Iggy]

If a photon sees no time pass as it goes from A to B, and sees no distance traveled as it goes from A to B and has no Mass to move from A to B, I would say that is as "restful" as you can get. Since point A and point B are "glued" together by the photon traveling between them, and the impulse getting from A to B is what defines space and time, then the photon, the graviton, and anything else that connects point A and B at 186,000miles per second, is not a candidate for moving or being at rest, or having a relative velocity to any one particular other thing. Is it?

 

Regards, TAR2

Owl wasn't talking about the perspective of light, and length contraction and time dilation equations don't apply to light (although this is a typical misapplication). To say that light experiences no time or space is to apply equations outside of their boundary. I would say more, but I don't want to venture off topic.

 

Anything that moves from A to B can't be at rest relative to A and B -- this was my point. You can't measure [math]\overline{AB} [/math] without sending something from A to B.

[tar]

Iggy,

 

Oh. I understand. But there is the historical knowledge, of having sent something between A and B that "gives" us a knowledge of the distance. And then, we are in a position to predict the results, of repeating the experiment.

 

As much about reality, there is what has happened before, that "structures" the situation. That makes it real.

 

Time, in this regard, in my estimation, is something that we experience continually, and "measure" in retrospect.

 

Spacetime then is not something handily "present". That is, it does not appear to be something you can step out of and take a look at. There is no actual way to get out of it, or any platform available (other than here and now), where you can take a look at it.

 

There is however an "understanding" of it, that we already have. An analog model of the world, built in the synapses and connections and layout of our brains, that places actual items in the real world at various "distances" from us in space, and various events, in their proper "place" in time.

 

Time is an actual constituent of reality. One that we have already, as Kant would say, an intuition of.

Space is Kant's other "pure" intuition. Between the two, we have spacetime, if you will.

 

But simultaneity needs some heavy agreement on some rather deep "thoughts".

 

Perhaps the manifolds and equations lay out exactly what it is that I already have an intuition of. Perhaps they make of it, something that it is not. There are easy misunderstandings in "what is meant". And perhaps subtle misapplications, where an analogy is taken too far, or into a domain, where it does not belong.

 

It seems reasonable to me, that if the universe is a certain age, then ALL of it is that age. That makes it hard to figure what somebody could possibly mean by time slowing down or speeding up. Every piece of the universe, should have had the same time to evolve to where and how it is, in relationship to the rest, and should be at the point where the next moment, for it, has never before occurred. Each peice, at whatever grain size you choose, should have a past history, a present state, and a future state.

 

And there is no way to get to another place in the universe, without taking some time to get there, not actually.

 

But we can mentally take the trip, in "no time".

 

I think it important to note, the distinctions between, (as Owl put it), the map and the territory.

 

Regards, TAR2

[Iggy]

But there is the historical knowledge, of having sent something between A and B that "gives" us a knowledge of the distance.

As far as my point is concerned, it doesn't matter if something was sent from A to B 10 years ago or 10 minutes ago. The point is to counter Owl's claim that *only* things at rest to the thing being measured will measure distance accurately. In fact, something at rest can't measure distance at all. When the measurement happened is really beside the point.

 

Spacetime then is not something handily "present". That is, it does not appear to be something you can step out of and take a look at. There is no actual way to get out of it, or any platform available (other than here and now), where you can take a look at it.

I can't quite make sense of this. Space-time spans time. Measurements of it made yesterday, today, and tomorrow, are all measurements of the same space-time.

 

Time is an actual constituent of reality. One that we have already, as Kant would say, an intuition of.

Space is Kant's other "pure" intuition. Between the two, we have spacetime, if you will.

That is a fantastic point!... especially in terms of the ontology of time.

 

For humans to understand perception they categorize data in terms of space and time. Kant called time a category.

 

This means, according to Kant, that an object cannot be experienced unless it has the property of time -- or, put more correctly, it can't be experienced unless the thing experiencing it has an a priori category of time in which to organize the perceptive data of that object. I think this has significant philosophical implications.

 

Perhaps the manifolds and equations lay out exactly what it is that I already have an intuition of. Perhaps they make of it, something that it is not.

I wouldn't say they make it into something that it is not.

 

I thin we can put this into the language of philosophy easily. Humans have three complimentary intuitions that are pertinent to what we're talking about: space, time, and movement. What is at issue here is the relationship between the three. Does the amount of space and the amount of time depend on movement. Intuition says no, but relativity and observation says yes.

 

This doesn't mean that time, space, and movement are *not* categories like Kant believed they were -- that they make it something that it is not. It just means that the three categories work a little different than intuition would expect.

 

It seems reasonable to me, that if the universe is a certain age, then ALL of it is that age. That makes it hard to figure what somebody could possibly mean by time slowing down or speeding up.

A good answer to this is found on this page with the paragraph that starts "The question that may be raised in philosophical cosmology is whether this cosmic time constitutes an absolute time..."

Edited August 7, 2011 by Iggy

[tar]

Iggy,

 

Still working on what "understandings" we can have, without relating one thing to another. And how much "time" it takes to make the comparison.

 

Such an investigation is one of the reasons I am on this board, and particularly on this thread.

 

Critical to the discussion though, is the fact that "time marches on" with or without us. And this progression is something that we are subject to, along with everything around us, and by extention, a "thing" that is happening everywhere, all the time, and has been going on since the beginning of the universe, and will continue to go on for a very long time, since we have no good evidence that it has any reason to stop.

 

Regards, TAR2

[Kturbo]

I don't think time needs matter to exist,I believe it is always there.I believe we are confusing time itself verses the detection of the elapse of time.Yes matter affects time,it's like throwing a stone in a pond that is absolutely still.The pond would still be there even if there was no stone to throw in it.If there were no matter in the universe,there would not be any way to detect time or measure it,but that does not mean its not there.

[Iggy]

I don't think time needs matter to exist,I believe it is always there.I believe we are confusing time itself verses the detection of the elapse of time.Yes matter affects time,it's like throwing a stone in a pond that is absolutely still.The pond would still be there even if there was no stone to throw in it.If there were no matter in the universe,there would not be any way to detect time or measure it,but that does not mean its not there.

Do you have a scientific theory that suggests these things are true?

 

Einstein, on the issue, said:

 

People before me believed that if all the matter in the universe were removed, only space and time would exist. My theory proves that space and time would disappear along with matter.

 

When Einstein says that his theory proves something we should probably give that quite a bit of weight.

[owl]

No, you've been arguing that length contraction doesn't exist and that there are certain preferred reference frames.

 

Incidentally, the spacetime that gets curved is a part of general relativity, not special relativity, and explains gravity, not time dilation or length contraction. No curvature is required for length contraction and time dilation. No "thing" must be curved.

 

I’ve been arguing that length contraction has not been demonstrated on macro scale like the flattened earth scenario, which is not correct by all accounts of earth science at rest with earth. (Is "proper shape" a relevant distinction here?)

Maybe I misspoke about GR vs SR, but I don't know where. I have often said that almost all GR explanations begin with some version of "mass curves spacetime." Also, I have often acknowledged that lightspeed is invariant through space, as per SR. However the philosophy of objective realism demands that distances between astronomical bodies does not contract or expand with perspective (FOR) from which they are measured, which would be a form of idealism... that there are no intrinsic, objective properties of objects, so then reality depends totally on how things are seen. Obviously there is a conflict between SR and the above realism. I do not know the solution. (As I said, still struggling with it, because I know that earth is not nearly flattened, for instance.)

 

swansont:

Nobody has claimed it was a medium. In fact, Cap'n just said to not worry about that distinction. It's a coordinate system. 3 spatial and one time dimension.

 

So when they say mass curves spacetime they mean it curves a coordinate system, a map? What curves in the real world... is the ontological question, which has not yet been addressed.

 

The distinction is reminiscent to that between a map and a globe. The shortest distance between points is not a straight line on a map. The geometry that describes space and time is not flat. Light travels along a geodesic rather than a straight line.

 

On a flat map (plane) the shortest distance between two points IS in fact a straight line between them. (Maybe you just misspoke?)

On a globe the *actual* shortest distance between two points is still a straight line *through the globe*, while the surface distance between them must, of course, follow the spherical curvature.

 

me:

...it still seems to me that the "burden of proof" for rods and earth and astronomical distances "contracting" is still on those who claim there is such evidence, as you seem to do.

 

(The "you" was, I think, addressed to Cap 'n R)

 

Swansont:

Lots of room for error? No, not so much.

 

I'm not a particle accelerator specialist in atomic physics, so I'll grant the above... that the "end points" ergo distances between the particles can be measured precisely. But that leaves large scale length contraction unconfirmed, and my point above unaddressed here.

 

No physical tests at all (your realism) leaves a lot more room for error than empirical science.

 

As above, what empirical evidence is there for large scale length contraction? None so far. And there is a huge body of "physical tests" in earth science confirming earth as nearly spherical, but none confirming it as severely oblate, as length contraction from an extreme FOR claims.

 

I said:

So, the question "What shape is earth?' then depends on how you look at it, as if it had no shape of its own... just like idealism, which I find an absurd philosophy.

I think that relativity claims that we can not know the shape of earth (or the "actual distance") to the sun, and that this makes a mockery of science...

 

You replied:

Once again, you state something which is not claimed. Relativity does not say we can't know the shape of the earth. It says that the answer you get will depend on the frame of reference you are in. There is no universally true answer to that of length (or time).

To my, "What shape is earth?' then depends on how you look at it, as if it had no shape of its own... just like idealism,"...

you answer,

"It says that the answer you get (to 'what shape is earth?') will depend on the frame of reference you are in.

 

... so it DOES depend on how you look at it, which is idealism, denying realism.

 

I didn't ask for your definition. I asked you to confirm that you agree that you are not claiming that time doesn't exist. Since you have given a definition several times it would seem the answer is that you are not, but then you say you don't accept spacetime. You can't have it both ways. If space and time don't exist, why does time need a definition?

Also from a previous post, you asked:

I was under the impression that you were interested in what time "is" rather than contending that it does not exist. If time and spatial dimensions exist, you have spacetime.

 

To be perfectly clear, again, the ontology as I see it is that time is simply the event duration of physical processes. I agree that "time passes"... that "elapsed time" is meaningful without granting time the ontological status of something that expands or dilates. Events require a longer or shorter time/duration to happen.

 

Likewise, I contend that space is simply the volume in which things (actual entities) exist. Space and the elapsed time required for things to move through space do not, ontologically constitute a curved 'whatever,' as is constantly the claim of GR for spacetime.

 

Finally re:

Non-Euclidean coordinate systems don't exist?

 

First, a coordinate system is a map. It exists in the abstract or as a 3-D model to describe real stuff that exists in the real world, where things exist and move in relation to each other and "time passes" as things move around. (Again, the map is not the territory.)

 

The point of departure for non-Euclidian geometry was to deny Euclid's fifth postulate and claim that parallel lines do actually intersect if extended far enough, like into mathematical infinity. There is no referent in the real world for this claim, and lines that do intersect are not parallel lines by definition. So non-Euclidean geometry got off to a nonsense/bogus start... and never came back.

Then the intrinsic vs extrinsic curvature relative to different “manifolds” was conceived to create curved space, where previously space was simply three dimensional volume, i.e., nothing to curve. They even invented four dimensional space (not including time.) That must exist only in their minds, because there is no extra spatial dimension conceivable after 3-D volume. Hope this answers your existential question.

Edited August 10, 2011 by owl

[swansont]

On a flat map (plane) the shortest distance between two points IS in fact a straight line between them. (Maybe you just misspoke?)

On a globe the *actual* shortest distance between two points is still a straight line *through the globe*, while the surface distance between them must, of course, follow the spherical curvature.

 

Consider that we are constrained to travel on the surface. On a map, draw a straight line between two distant points. That line will not be what you get if you calculate the shortest path on a globe. On a globe, it's a great circle.

 

http://en.wikipedia.org/wiki/Great-circle_distance

 

The two lines will not be the same, e.g. the line from New York City to Paris on a map will pass through intermediate points that the great circle will not. If you use the wrong geometry you get the wrong answer. Similarly, you have to use curved spacetime when dealing with gravity. The geometry is not flat.

[Cap'n Refsmmat]

I’ve been arguing that length contraction has not been demonstrated on macro scale like the flattened earth scenario, which is not correct by all accounts of earth science at rest with earth. (Is "proper shape" a relevant distinction here?)

All accounts of Earth science at rest with Earth could say anything and they would not contradict what SR or GR predicts about Earth in a different reference frame. At rest with Earth, SR and Earth science agree splendidly.

[Iggy]

Nobody has claimed it was a medium. In fact, Cap'n just said to not worry about that distinction. It's a coordinate system. 3 spatial and one time dimension.

So when they say mass curves spacetime they mean it curves a coordinate system, a map? What curves in the real world... is the ontological question, which has not yet been addressed.

Yes, it curves a coordinate system. The coordinate system represents what clocks and rods measure. A "clock" is any regularly repeating physical process.

 

To be perfectly clear, again, the ontology as I see it is that time is simply the event duration of physical processes.

What is "duration"? What is an "event"?

 

You couldn't define "velocity" either.

 

The point of departure for non-Euclidian geometry was to deny Euclid's fifth postulate and claim that parallel lines do actually intersect if extended far enough, like into mathematical infinity. There is no referent in the real world for this claim, and lines that do intersect are not parallel lines by definition. So non-Euclidean geometry got off to a nonsense/bogus start... and never came back.

What is Euclid's fifth postulate and how have you proven it correct when hundreds of years of mathematicians have failed at that task?

 

What would a "referent in the real world" of a violation of Euclid's fifth look like and how have you proven that there isn't one? "Speculations must be backed up by evidence or some sort of proof."

[owl]

All accounts of Earth science at rest with Earth could say anything and they would not contradict what SR or GR predicts about Earth in a different reference frame. At rest with Earth, SR and Earth science agree splendidly.

But you keep claiming that earth IS an oblate spheroid (with 1/8th its spherical diameter) for the high speed travelers,... as seen from a near 'C' fly by frame of reference.

The contradiction I keep hammering on is that earth can not BE both nearly spherical and severely oblate. It is, in the real world (see philosophy of realism), one or the other but not both.

Earth science has determined that it is,in fact, nearly spherical. Length contraction of earth's diameter as seen from above frame of reference has never been experimentally verified and remains a "thought experiment." Yet you (and relativity) insist that both shapes are equally valid. Nonsense.

Would you please address objection.

This, of course, belongs in the "frame of reference" thread... but...

 

Consider that we are constrained to travel on the surface. On a map, draw a straight line between two distant points. That line will not be what you get if you calculate the shortest path on a globe. On a globe, it's a great circle.

 

http://en.wikipedia.org/wiki/Great-circle_distance

 

The two lines will not be the same, e.g. the line from New York City to Paris on a map will pass through intermediate points that the great circle will not. If you use the wrong geometry you get the wrong answer. Similarly, you have to use curved spacetime when dealing with gravity. The geometry is not flat.

First, you have not replied to any of my comments in post 260.

For openers you said (my bold):

 

The distinction is reminiscent to that between a map and a globe. The shortest distance between points is not a straight line on a map. The geometry that describes space and time is not flat. Light travels along a geodesic rather than a straight line.

Then you assert a basic non-Euclidean assumption as if it's a fact.

(With no reply to my criticism of non-Euclidean geometry.)

 

I said:

On a flat map (plane) the shortest distance between two points IS in fact a straight line between them. (Maybe you just misspoke?)

On a globe the *actual* shortest distance between two points is still a straight line *through the globe*, while the surface distance between them must, of course, follow the spherical curvature.

No reply. Rather a link to the well known Wiki info on great circles.

So Euclidean is the "wrong geometry" with no discussion.

 

Similarly, you have to use curved spacetime when dealing with gravity. The geometry is not flat.

You “have to?”

Not if one contests the existence of curved spacetime, like my sources in the Ontology of spacetime thread.

Anyway “flat” is a misnomer for Euclidean 3-D space.(Invented by non-Euclideans.) Flat describes a plane. The space in which cosmic bodies interact gravitationally is not a “flat” plane but a 3-D cosmos. Add time if you want for movement, but it is not a “dimension” unless elapsed time for event duration is to be called a dimension.

[swansont]

But you keep claiming that earth IS an oblate spheroid (with 1/8th its spherical diameter) for the high speed travelers,... as seen from a near 'C' fly by frame of reference.

The contradiction I keep hammering on is that earth can not BE both nearly spherical and severely oblate. It is, in the real world (see philosophy of realism), one or the other but not both.

Earth science has determined that it is,in fact, nearly spherical. Length contraction of earth's diameter as seen from above frame of reference has never been experimentally verified and remains a "thought experiment." Yet you (and relativity) insist that both shapes are equally valid. Nonsense.

Would you please address objection.

This, of course, belongs in the "frame of reference" thread... but...

Why is it assumed that the philosophy of realism is correct? A contradiction implies an assumption is false. Can you guess which one it is?

 

And now for the question that you refuse to address: how do you tell, objectively, which is the proper frame of reference to make the determination of distances and times — in this case, the shape of the earth?

[owl]

swansont:

And now for the question that you refuse to address: how do you tell, objectively, which is the proper frame of reference to make the determination of distances and times — in this case, the shape of the earth?

(my bold)

Well, you could ask a thousand scientists what earth's shape is without mentioning the unverified thought experiments on large scale length contraction and see how many say "nearly spherical" and how many say, "squished nearly flat" (or "a very oblate spheroid.")

You will probably get a consensus of all 1000 that it is the former, not the latter.

But, of course, consensus doesn't make it true, like a flat earth was not true, though commonly believed to be so.

So I will go with disclaiming the bold above as contrasted with a mountain of empirical, objective observations and measurements which conclude it is nearly spherical, to a very high degree of measurement precision.

(It's hard to believe that, in a science forum, I am challenged to verify earth's very well known shape to scientists who believe that squished nearly flat is just as valid!... based on an experimentally unverified thought experiment.)

[Cap'n Refsmmat]

In the Earth's reference frame, the predictions of:

 

• Earth science: Nearly spherical Earth.
  
• Newtonian mechanics: Nearly spherical Earth.
  
• Relativity: Nearly spherical Earth.
  

 

So how do the observations of Earth science contradict relativity?

[swansont]

swansont:

(my bold)

Well, you could ask a thousand scientists what earth's shape is without mentioning the unverified thought experiments on large scale length contraction and see how many say "nearly spherical" and how many say, "squished nearly flat" (or "a very oblate spheroid.")

You will probably get a consensus of all 1000 that it is the former, not the latter.

 

I have no doubt you could phrase the question to get that answer, but it would be a dishonest question. In this frame, it's a sphere. If you made it clear you were discussing relativity, you would get a different answer.

 

But, of course, consensus doesn't make it true, like a flat earth was not true, though commonly believed to be so.

So I will go with disclaiming the bold above as contrasted with a mountain of empirical, objective observations and measurements which conclude it is nearly spherical, to a very high degree of measurement precision.

(It's hard to believe that, in a science forum, I am challenged to verify earth's very well known shape to scientists who believe that squished nearly flat is just as valid!... based on an experimentally unverified thought experiment.)

Again, in this frame, and absolutely nobody has taken a contrary position that this is true. The objection is to the philosophy of realism, or, should I say the unverified philosophy of realism. In this case, actually unverified, as opposed to the unscientific and incorrect implication above. (I'll go back to my previous example: you probably accept gravity, even though it is an "unverified thought experiment" except in a few places around the earth; I'm guessing you have never been anywhere it's been properly verified)

 

First, you have not replied to any of my comments in post 260.

For openers you said (my bold):

 

 

Then you assert a basic non-Euclidean assumption as if it's a fact.

(With no reply to my criticism of non-Euclidean geometry.)

 

I said:

 

No reply. Rather a link to the well known Wiki info on great circles.

So Euclidean is the "wrong geometry" with no discussion.

 

I ignored your straight line through the earth comment because I thought it was obvious we were talking about the surface.

 

And is the wiki article wrong, or right? Does a great circle correspond to a straight line on a map, or not?

[owl]

I quick reply. No "time." More later.

 

swansont:

Why is it assumed that the philosophy of realism is correct? A contradiction implies an assumption is false. Can you guess which one it is?

 

The assumption that all frames of reference yield equally valid results? (I’m guessing you think I am “wrong.”)

 

Realism 'realizes' that cosmos is intrinsic physical reality on its own, independent of how it is perceived.

So science’s job, investigating that reality, is to always find the observational perspective with the fewest errors due to unknown variables.

I’m "guessing" that viewing earth from a near lightspeed fly-by will not have the fewest errors of perception.

 

Idealism, in general, asserts that cosmos is as cosmos appears, like from various frames of reference. So there are as many different "versions" of it as there are perspectives or frames of reference.

 

This is as simple as I can state it. ( Btw,this should be in the frame of reference thread in Philosophy.)

 

And now for the question that you refuse to address: how do you tell, objectively, which is the proper frame of reference to make the determination of the shape of the earth?

 

I thought I had answered this many times ,and now again above. “Under the microscope” (at rest with the object examined) will clearly give the better results for properties of a micro-organism than some futuristic high tech scanning as one flies through the lab at near lightspeed. There is no reasonable argument against this.

Likewise, the closer the observer is to earth, at rest, the fewer unknown variables to introduce error. A perfectly sound principle of scientific investigation.

 

If you are so certain that the length-contracted version of earth’s shape is equally correct, why don’t you present experimental, objective, empirical evidence to support it? (Thought experiments are creative guess-work... way preliminary to verification.)

... and then go to any reputable earth science seminar/class/whatever and present a paper on earth's shape according to length contraction, with 1/8th its spherical diameter.

(Don't take it personally if you are boo-d out of the auditorium.)

 

This is getting tedious.

[swansont]

The assumption that all frames of reference yield equally valid results? (I’m guessing you think I am “wrong.”)

 

Realism 'realizes' that cosmos is intrinsic physical reality on its own, independent of how it is perceived.

So science’s job, investigating that reality, is to always find the observational perspective with the fewest errors due to unknown variables.

I’m "guessing" that viewing earth from a near lightspeed fly-by will not have the fewest errors of perception.

 

You guess wrong. Limitations of measurement are a completely separate issue, but this has already been explained to you.

 

 

Idealism, in general, asserts that cosmos is as cosmos appears, like from various frames of reference. So there are as many different "versions" of it as there are perspectives or frames of reference.

 

This is as simple as I can state it. ( Btw,this should be in the frame of reference thread in Philosophy.)

 

 

 

I thought I had answered this many times ,and now again above. “Under the microscope” (at rest with the object examined) will clearly give the better results for properties of a micro-organism than some futuristic high tech scanning as one flies through the lab at near lightspeed. There is no reasonable argument against this.

Likewise, the closer the observer is to earth, at rest, the fewer unknown variables to introduce error. A perfectly sound principle of scientific investigation.

 

If you are so certain that the length-contracted version of earth’s shape is equally correct, why don’t you present experimental, objective, empirical evidence to support it? (Thought experiments are creative guess-work... way preliminary to verification.)

... and then go to any reputable earth science seminar/class/whatever and present a paper on earth's shape according to length contraction, with 1/8th its spherical diameter.

(Don't take it personally if you are boo-d out of the auditorium.)

 

This is getting tedious.

I have a hundred years of evidence supporting relativity. Time dilation has been confirmed and is continually confirmed with GPS. Particle accelerators confirm the non-Newtonian relationship of energy with speed. Nuclear reactors and weapons confirm the mass-energy relation. And so on, and so on. But if you want to dishonestly restrict what you will accept as evidence for relativity, then I probably can't.

[StringJunky]

You guess wrong. Limitations of measurement are a completely separate issue, but this has already been explained to you.

 

 

 

I have a hundred years of evidence supporting relativity. Time dilation has been confirmed and is continually confirmed with GPS. Particle accelerators confirm the non-Newtonian relationship of energy with speed. Nuclear reactors and weapons confirm the mass-energy relation. And so on, and so on. But if you want to dishonestly restrict what you will accept as evidence for relativity, then I probably can't.

 

Swansont

 

If you stopped replying now, you would be justified...you are talking to a brick wall. Even if Owl hasn't, as a bystander, I learnt loads...thanks.

[owl]

Cap ‘n R:

In the Earth's reference frame, the predictions of:

 

Earth science: Nearly spherical Earth.

Newtonian mechanics: Nearly spherical Earth.

Relativity: Nearly spherical Earth.

 

So how do the observations of Earth science contradict relativity?

 

No doubt, “in earth’s reference frame," but...

To recap:

You said that from near lightspeed fly-by frame of reference earth IS severely oblate, and, since there is “no preferred frame of reference” in relativity, that is just as accurate a description as nearly spherical. I maintained that the latter is the accurate, realistic, objective description, and, since earth does not change from one shape to another, one is right (“preferred”), nearly spherical, and the other wrong, very oblate.

OK?

 

swansont:

I ignored your straight line through the earth comment because I thought it was

obvious we were talking about the surface.

 

And is the wiki article wrong, or right? Does a great circle correspond to a

straight line on a map, or not?

 

I was talking about an actual straight line as the shortest distance between two points (Euclidean), whether on a flat map or *through* a spherical globe. No one is arguing against lines on the surface of a globe being curved.

Correspond? Sure, if you break down the globe and make it into a flat map. What’s the point? A curved line is not a straight line. The shortest distance between two bodies in space is still a straight line. Planetary orbits are not straight lines through “curved space." They are curved lines through empty space, which is (arguably... see spactime ontology thread)) not *something* that can be curved. “Curved space” is a non-Euclidean concept, begging the ontological question, “what is it that is said to be curved”, besides the trajectories of objects as pulled by gravity?

[michel123456]

(...)The contradiction I keep hammering on is that earth can not BE both nearly spherical and severely oblate. It is, in the real world (see philosophy of realism), one or the other but not both.

(...)

 

I am supporting Owl.

To me Reality (with capital R) is one. This one and only Reality is observed differently, by definition, from any FOR: that is Relativity.

And as far as I can understand, the FOR which coincides with the object under examination is the closest to this Reality.

 

Obviously, for Swansont, there is a multiple reality, there is no Reality with capital "R", and what is observed from any FOR is equally correct than any other. I have strong difficulties to accept this interpretation.

[Cap'n Refsmmat]

The difference between reference frames is merely a change of coordinates, not a change in reality. The weird effects come from the coordinates being four-dimensional.

[owl]

The difference between reference frames is merely a change of coordinates, not a change in reality. The weird effects come from the coordinates being four-dimensional.

Are you referring to non-Euclidean 4-D space (four spatial dimensions), the fourth of which exists only in the minds of non-Euclideans) or 3-D space plus time, the movement factor (not in dispute?)

If the former, the "weird effects" are in the minds of those who add an extra dimension to 3-D space (which describes all volume.) If the latter, then spherical 3-D bodies in 3-D space remain spherical, without "weird" distortions.

 

Btw, TAR,

None of us are sticking to title topic here. No problem.