Relativity of Motion discussion from “What is Time”

[Michael Mooney]

Modest:

I will first restate the points from my last post which you did not address.

 

Removing relative points of view from "the equation" leaves cosmos as it is and as it was before relativity and all its "equations", and as it will be long after all human analysis.

 

My little exercise was simply an illustration that Haley's comet was in orbit around the sun, as in your original proposition, and then the sun magically disappeared (and everything else) but the comet, with no new forces acting on it, it simply continues to move in a trajectory *tangent to what its orbit was*... this through empty space with no other reference points. You have repeatedly demonstrated your inability to even conceive of such a thought experiment.

You:

Not only am I incapable of comprehending how a line is tangent to something that doesn't exist, the concept is not comprehensible. Yet, you are again comparing the motion and direction of the comet to its previous orbit which confirms that motion and direction require two things to have meaning.

Me:

The comets new straight line trajectory is tangent to the orbit it *had* (past tense)... "previous orbit" before the rest of the cosmos disappeared. (Thought experiment, remember.) It is now an imaginary/virtual orbital path without the comet *in that orbit* any longer.

 

Do you think that all the solar system distances given in astronomical websites are accurate, objective, etc. or does the *actual distance*, say moon to earth, change with velocity of "frame of reference?

Same deal as earth's spin and orbit slowing down and speeding up with fluctuations in "clocking them."

 

Do you get this ontological distinction, which violates your absolute belief that "everything is relative.

Nature's cycles and bodies in space have a "life of their own" without the fluctuating concepts of "time dilation" space/distance contraction/expansion.

 

Now to your last post:

 

You:

You continue to say we don't comprehend or we're not able to comprehend. But, the issues you are expressing such as relative vs. absolute space and relative vs. universal now are ordinary stumbling blocks that we are all too well aware of. Studies have been done on how prevalent they are and the best way to help students with them.

 

I say, not "absolute space" but empty space, everywhere not occupied by cosmic "stuff" on all scales. Not a medium that is contractible/expandable. My disagreement with relativity in this regard does not make me wrong and malleable "spacetime" right.

Likewise my assertion that "it" is always now everywhere, not dependent on the principles of relativity. (See again my often repeated "signature post" on the ontology of time: p.59, post 584.)

 

You:

 

The logical consequences of your worldview are internally inconsistent. It is impossible for a constant speed of light to accompany absolute distance and time in the way you have outlined. Again, that you fail to recognize or understand this makes it no less true.

 

I do not question the constant speed of light. But it travels through empty space, like between sun and earth, which can be "measured" or not. It is the same "distance" (ignoring out-of-round orbit for the moment) no matter what "units of distance" are applied. This is what I mean by cosmos as-is or in and of itself regardless of relative perspective.

 

You:

Where you lost me, in that I am no longer taking you seriously, is trying to argue that a single point has an absolute distance. If you are not willing to acknowledge that distance requires two points then useful communication is impossible.

 

I never said that "a single point has an absolute distance." Quite the contrary. I said that a point is a locus with no dimension at all. If this is a conversation, listening on your part is required.

 

I said that your electron would be the same distance from the locus where Earth was (after its disappearance) as with the Earth still occupying that locus. So that locus (a virtual point with no Earth there anymore) and your electron still define the distance *between those two points.*

 

And again:

If you (all) simply can not see the ontology of... cosmos as-is existing "all by itself" regardless of all relative perspectives, then there is really nothing left for me to say.

Michael

[Michael Mooney]

Michael,

 

If the comet is moving in a universe with no other objects, how can you tell that it's moving?

 

That is, how is motion with one point and no others, defined?

 

E pur si muove, ;)

Buffy

Sorry for the delay... I was not able to post for a couple of days due to a glitch of unknown origin.

Maybe my last post to Modest answered you.

My thought experiment took the comet, already moving in its natural orbit around the sun, and removed the sun and everything else but the comet. Since there would be nothing left to exert force on the comet, it would continue to move with the same momentum/inertia it had before but with no sun-gravity, its trajectory would be a line (not a point) tangent to the curve of its previous orbit, now just a "virtual" orbit.

 

This is "knowing" it would be continuing to move by reason that nothing is left to stop it.

 

Michael

[freeztar]

there is really nothing left for me to say.

Michael

 

The end.

 

Seriously...all of us apparently aren't going to be able to show you the error in your thinking and vice versa. Perhaps we should just agree to disagree. ;)

[coldcreation]

I said that your electron would be the same distance from the locus where Earth was (after its disappearance) as with the Earth still occupying that locus. So that locus (a virtual point with no Earth there anymore) and your electron still define the distance *between those two points.*

 

My thought experiment took the comet, already moving in its natural orbit around the sun, and removed the sun and everything else but the comet. Since there would be nothing left to exert force on the comet, it would continue to move with the same momentum/inertia it had before but with no sun-gravity, its trajectory would be a line (not a point) tangent to the curve of its previous orbit, now just a "virtual" orbit.

 

Actually, the comet would be traveling on a geodesic path (not a 'straight' line; in the Euclidean sense) relative to the locus of points where the earth would have been. Just as the locus of points would appear (if they could be seen) to be traveling a geodesic path from the perspective of the comet.

 

There seems to be no way around relative motion, even within the context of your thought experiment, and even in the absence of gravity.

 

 

Edit: The comet would have a gravitational field, since it has mass. To do away with gravity in your thought experiment you could reduce the comet to a point (as modest had done). What you are left with is the spacetime of special relativity described by the Minkowski metric, or Minkowski space. In this type of space (the same type that you describe in your thought experiment) relative motion is the rule, not an exception.

 

 

CC

[Michael Mooney]

The end.

 

Seriously...all of us apparently aren't going to be able to show you the error in your thinking and vice versa. Perhaps we should just agree to disagree. :)

 

You assert the assumption that my thinking is in error without evidence or argument in the context of the points made in my last few posts. I formally request that you present this evidence and/or argument which shows, without a doubt that my thinking is in error.

 

BTW, "because everything is relative" is not such an argument.

You are just saying, like the fictional "Borg" (Star Trek), "Resistance is futile;... You will be assimilated!"

Michael

[Buffy]

My thought experiment took the comet, already moving in its natural orbit around the sun, and removed the sun and everything else but the comet. Since there would be nothing left to exert force on the comet...

 

This is "knowing" it would be continuing to move by reason that nothing is left to stop it.

All you do here is move the point that you're comparing the comet's motion to--the sun--temporally. You're still using the sun as the second point.

 

So the question still stands--only slightly restated--if you observe just after the sun and everything else disappeared, how do you know the comet is moving?

 

From an ontological standpoint, you have to answer this question without reference to the disappearance of the rest of the universe, because that would be an axiom. One, by the way, that basically implies change in relative distance as the essential element of measuring motion.

 

Nobody, as long as he moves about among the chaotic currents of life, is without trouble, :)

Buffy

[Michael Mooney]

Actually, the comet would be traveling on a geodesic path (not a 'straight' line; in the Euclidean sense) relative to the locus of points where the earth would have been. Just as the locus of points would appear (if you they could be seen) to be traveling a geodesic path from the perspective of the comet.

 

There seems to be no way around relative motion, even within the context of your thought experiment, and even in the absence of gravity.

 

 

Edit: The comet would have a gravitational field, since it has mass. To do away with gravity in your thought experiment you could reduce the comet to a point (as modest had done). What you are left with is the spacetime of special relativity described by the Minkowski metric, or Minkowski space. In this type of space (the same type that you describe in your thought experiment) relative motion is the rule, not an exception.

CC

 

Actually, I don't believe, with the whole non-Euclidean fabrication of curved space, that there are no straight lines. And Earth is not a player in the exercise. When sun vanishes, so does the comet's orbit, hence it continues in a straight line (with no moving "points")... no manifest "line" at all but just a description of its new vector, no longer in a curved orbit.

There is *nothing left to observe* "from the perspective of the comet"... not even a "line" through *now empty* (but for the comet) space.

"...no way around relative motion...?" I know that relativity theory is very *absolute* about this, but I disagree, as in a previous post (which I will not repeat) quoting wiki on the physics of motion....

 

http://en.wikipedia.org/wiki/Motion_(physics)

 

Motion is always observed and measured relative to a frame of reference. As there is no absolute reference frame, absolute motion cannot be determined; this is emphasised by the term relative motion.[2] A body which is motionless relative to a given reference frame, moves relative to infinitely many other frames. Thus, everything in the universe is moving.[3]

 

In a previous post I spoke of thinking "beyond the frame" (of reference) which is a basic axiom of relativity, denying what I call "intrinsic motion"... which the comet exercise was meant to illustrate.

 

My comet exercise did not reduce it to a point, and it would be the only mass. As per Minkowski "spacetime" I did my best to debunk that as a malleable medium throughout my "spacetime" thread.

 

Have you ever read the book, ""Minkowski Space-time: A Glorious Nonentity"? (I have not, but quite an interesting title!) Are you familiar with the several annual conferences on "The Ontology of Spacetime?" It is not an established "given" as you suppose.

 

And finally, (a point which Modest has been avoiding... for good reason), I will never be convinced that distances between bodies in space change with relative perspective or that spinning and orbiting planets fluctuate (speeding up and slowing down) with science's fluctuating instruments of measure (clocks), or as measured from different frames of reference, etc.

 

Michael

[Michael Mooney]

As per CC's prompt, this is a cut and past from the time thread:

 

Originally Posted by jedaisoul View Post

Well thanks for the general agreement, but why would space continue to exist if there were no universe? No matter, no energy. Just nothing.

 

Nothing is, by definition, no thing. It does not exist. In the absence of everything that exists, there would be no thing. Nothing. Not even "empty" space. So to exist when everything else had gone, space would have to be something. So "empty" space would not be empty. There would be "space" there.

 

So do you believe in an aether, a material space? If not, what is this space made of, if it is not material, but not nothing either?

If space is defined as emptiness, void, infinite volume, the no-thing-ness between and beyond existing "things"... as I do, then:

 

Space is nothing... no "it"... the infinite nothingness *in which* all "things" exist... what's left (nothing) if everything (cosmos) disappeared. "Empty space" is synonymous with absence of any/all things. No "it" to exist.

No belief at all. Those who can not conceive of space as emptiness (lack of anything) insist that "it" (void) can not be void but must be some kind of medium, and so they find names for "it" like "aether", etc.

Michael

[freeztar]

I will never be convinced

 

 

This is the point I was trying to make in my last post.

 

You see our thinking to be in error and we are not willing to accept the truth. We see your thinking to be in error and you are not willing to accept the truth.

 

It's a stalemate as far as I can see.

[jedaisoul]

If space is defined as emptiness, void, infinite volume, the no-thing-ness between and beyond existing "things"... as I do, then:

 

Space is nothing... no "it"... the infinite nothingness *in which* all "things" exist... what's left (nothing) if everything (cosmos) disappeared. "Empty space" is synonymous with absence of any/all things. No "it" to exist.

No belief at all. Those who can not conceive of space as emptiness (lack of anything) insist that "it" (void) can not be void but must be some kind of medium, and so they find names for "it" like "aether", etc.

Ok, so you don't believe in an aether. That's fine, I don't either. I can conceive of space as nothingness. I've said that it is nothing more than the distance between objects. Furthermore, if all the physical entities making up the universe were removed, there would be nothing. No thing. So we agree so far: Yes/no?

 

But you refer to space as "emptiness, void, infinite volume". That's a problem for me. To be emptyness or a void, there would have to be a space that is empty. A space with metric properties: position, size and orientation. You seem to agree with that because you give it a size: "infinite volume". Are we still in agreement: Yes/no?

[coldcreation]

This is the point I was trying to make in my last post.

 

You see our thinking to be in error and we are not willing to accept the truth. We see your thinking to be in error and you are not willing to accept the truth.

 

It's a stalemate as far as I can see.

 

:)

 

I see it more as a checkmate.

 

 

CC

[Michael Mooney]

jedaisoul;283361]Ok, so you don't believe in an aether. That's fine, I don't either. I can conceive of space as nothingness. I've said that it is nothing more than the distance between objects. Furthermore, if all the physical entities making up the universe were removed, there would be nothing. No thing. So we agree so far: Yes/no?

 

Yes.

But you refer to space as "emptiness, void, infinite volume". That's a problem for me. To be emptyness or a void, there would have to be a space that is empty. A space with metric properties: position, size and orientation. You seem to agree with that because you give it a size: "infinite volume". Are we still in agreement: Yes/no?

 

No. What is the problem for you in "a space that is empty" being "emptiness" or "void" devoid of "properties" assigned by scientific metrics like "position, size, and orientation," ... all "properties" of things/stuff/bodies/etc existing *in* space as defined above?

"Infinite volume" has no "size." Size is defined (made finite) by boundaries like one size being bigger or smaller than another size.

 

There can be no end to space, as I have argued many times. Emptiness without end. What "end" could there possibly be to space? If you can conceive of such an end, please let me know, and I will ask what such an end is composed of and then what lies beyond it. See what I mean?

 

To be clear, space is that emptiness in which nothing exists, as between and beyond things that do exist.

 

OK?

Michael

[Michael Mooney]

This is the point I was trying to make in my last post.

 

You see our thinking to be in error and we are not willing to accept the truth. We see your thinking to be in error and you are not willing to accept the truth.

 

It's a stalemate as far as I can see.

 

Please respond to my formal request:

You assert the assumption that my thinking is in error without evidence or argument in the context of the points made in my last few posts. I formally request that you present this evidence and/or argument which shows, without a doubt that my thinking is in error.

Is this not a requirement of participation in this forum... or is that rule just about demanding"references" and not applicable to requests to show me in your own words where you think I am wrong when so (repeatedly) accused?

Michael

[Michael Mooney]

Buffy;283353]All you do here is move the point that you're comparing the comet's motion to--the sun--temporally. You're still using the sun as the second point.

 

Not "temporarily." The exercise removed all but the comet... period. The illustration was then to demonstrate that the comet would still be in motion, with nothing to change its previous speed and only its path (now a straight line trajectory in lieu of sun's gravity) changed, and that movement intrinsic, in and of itself, not "relative to" anything else, as nothing else then exists.

 

So the question still stands--only slightly restated--if you observe just after the sun and everything else disappeared, how do you know the comet is moving?

 

"Observe" what? No observers left! And I answered this already. How to say it differently?? Comet still moving with same momentum/inertia (relative to nothing!!) with the altered trajectory now explained many times.

 

From an ontological standpoint, you have to answer this question without reference to the disappearance of the rest of the universe, because that would be an axiom. One, by the way, that basically implies change in relative distance as the essential element of measuring motion.

 

I've answered this many times. Everything is in motion. Comparing the motion of one thing or point to another is not,ontologically required for each thing's movement to be real "all by itself"... the whole point of the comet exercise.

 

Of course, in the real cosmos, gravity is the mysterious cosmic glue by which all masses effect all other masses (no "matter" of how massive or far away... according to the universal law of gravitation.)

So all movement effects all other movement in the real cosmos. But that certainly does not mean that there is no movement without that it is compared to other bodies in motion.

 

So what of the exercise, Buffy? Must the comet freeze... no motion... after all else is gone? What stops it?

 

Can anyone here understand this point... and this post in total ?

Michael

[Buffy]

Now we're getting somewhere.

 

I had the feeling that much of this discussion was stalled on a misunderstanding in terminology here, and we've got a couple of examples to deal with here:

All you do here is move the point that you're comparing the comet's motion to--the sun--temporally. You're still using the sun as the second point.

Not "temporarily." The exercise removed all but the comet... period.

Do you understand the difference between the words "temporally" and "temporarily?"

 

I used the former, but your misunderstanding in referring to the latter indicates you completely missed my point.

 

The use of the word "temporally" is extremely significant here because it points out changes in position that are in spacetime, not just space. When you realize that your argument is still based on the notion of movement relative to the now "missing" sun, you have--very ironically--continued to base the definition of the term "motion" on "change in relative distance."

 

In none of your posts so far have you really defined motion without reference to another point in any critical way, except when you say:

Everything is in motion.

...which as I pointed out in my previous post--but which you chose to ignore--is making motion an axiom of your system. That is, it is definitional, and does not constitute an observable ontological property.

 

More importantly though, by saying that there are no entities that have the state "not in motion," you make the entire notion of "motion" ontologically uninteresting, because ontology is only interested in the properties of things that distinguish one set of entities from another.

 

If this is your position (excuse the pun), why are you even bothering to make an ontological argument about it?

 

But I may be reading too much into your statement, so please try to clarify if you can.

 

Note however that if you are not simply saying "everything is in motion, therefore the comet is moving" you do indeed need to have a definition for "motion" in order to make any discussion of it as an ontological property because it must be possible to perceive it in some way, shape or form.

 

This is where your understanding of the notion of "observe" gets contradictory: I have in my previous posts even granted several ways for there to be a way to measure motion that is not dependent on a in-Universe observer with a reference frame. Oddly enough, the one that is most supportable is to use ether as an effective Cartesian Coordinate system for the Universe, however you have insisted that you do not accept the existence of ether--something that most of the rest of us would agree with.

 

The other key mechanism is to literally be "outside the system": that is, to be able to see all points simultaneously as if the Universe were a big disk drive that would let you be anywhere you wanted to be at anytime.

 

But the weakness of this is that it still requires either a coordinate system or other objects to compare the motion to to determine "if it's really moving."

 

You need to explain motion without anything else being there to compare it to.

 

The comet exercise is simply using the *formerly existing point* represented by the Sun as the comparison point. It does not matter whether it was "there a minute ago and we were moving relative to it then, so we're moving relative to it now." You're still using it as a point of reference.

 

If everything is always in motion, then your entire position is pointless because it has not impact on reality, and therefore caries no ontological weight.

 

Asking the question:

So what of the exercise, Buffy? Must the comet freeze... no motion... after all else is gone? What stops it?

Completely misses the issue of defining "motion". When "everything disappears" it does not matter that "no one is there to observe it"--the absence of an observer does not make it an "intrinsic property. In fact, once everything disappears, it's not that it "freezes" but that motion ceases to be an intrinsic property.

 

This is the essence of the philosophical weakness of your argument, and you need to try to understand this distinction.

 

What it comes down to is that you're simply using the very kind of measurement that you claim is irrelevant to justify its irrelevance.

 

I hope you can see how ironic that is.

 

And it has absolutely nothing to do with supporting Relativity or any other cosmological theory: it's simply a logical contradiction.

 

Now if you can come up with a definition of motion that does not require a reference to another object--whether it's "there now" or "was just there"--then please do so because it would be quite an interesting topic to discuss.

 

Against logic there is no armor like ignorance,

Buffy

[watcher]

if the force field radiated by a charge particle is spherical, the particle is at rest,

if ellipsoidal, it is in uniform motion

if non linear distortion, it is accelerating.

the insight to this is simple, the spherical radiation is always at rest relative to space . the final geometrical shape of the field whether linear or non linear is the sum total of the interference of these radiation ( em waves)

 

if we factor in energy in the system, then there will be no symmetry of motion to speak of whereas one cannot distinguished what is at rest or in motion relative to one another, the whole philosophy is a farce. a more rational worldview for relativity is that nothing has independent existence , and all are interconnected, thus the unity of all things. (ie one substance or one essential make up)

 

special relativity appears to be a modern version of Ptolemy's epicycle theory, correctly describing the motions of the planets, as observed from Earth.

[freeztar]

show me in your own words where you think I am wrong when so (repeatedly) accused?

 

I will repeat what I and many others have been trying to get through to you.

 

Motion requires two points.

 

Saying that something is in motion when it is the only thing in the universe is untenable. It is a bit like saying that purple is still purple in a colorless universe. It doesn't make sense. It is illogical.

 

Are you familiar with Schrodinger's Cat?

The lonesome comet is a bit like the cat. It is both in motion and completely still. The only way to determine if the cat is alive or dead (the comet is moving or not) is to open the box (turn the universe back on) and see.