# 3D Space, relativity and presentism

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This is a spin-off from a parallel discussion here, in the context of different explanations of SR.

The compatibility of 3D Space with SR was put in doubt (if I correctly understood it!) based on the argument that 3D space implies presentism, and presentism is incompatible with SR. I suspect that there's an error somewhere in that logical scheme.

Mordred wrote:

I do not vote for the presentism argument. Nor the Lorentz ether absolute frame being a privileged observer. Relativity of simultaneity has specific requirements that are not merely "convention" The presentism argument (if I understand it correctly) is a 3d ontology as opposed to a 4d ontology. Presentism follows the logic argument the view that it is only the present "here-now" (the three-dimensional world at the moment `now') that exists.

1) the universe exists only at the constantly changing present moment (past and future do not exist)

2) the universe is three-dimensional

It is more real to think of physical reality as a four-dimensional existence, instead of the evolution of a three-dimensional existence

First I better define relativity of simultaneity. ( mainly for other readers)

1) homogeneous and isotropic space means that no 3d location is privileged or more convenient.

2) homogeneity of time throughout a homogeneous space has no privileged origin or privileged

3) two events in the same frame of reference are simultaneous if the clocks at two locations is identical

4)Two distant events are simultaneous in a given inertial reference frame if the light signals originating from the points where the events take place arrive simultaneously at the middle point in-between these origin points

5)The two synchronized clocks have the same running time.

between frames

1) two light sources generated simultaneous arrive back at origin point 0 at the same time.

2) two light sources emitted at different time arrive back at the origin at the same time. if ,

Presentism regards the event here-now as the most real, It should be stressed that it amounts to a contradiction in terms to say that the world is four-dimensional, but for every observer only the event "here-now" is real. If the world is four-dimensional all its events are equally real otherwise it would not be four-dimensional.This shows that in space time it is impossible to have an event, representing the event "here-now", which is more "real" than the other events. Therefore, objective now of time and objective becoming are impossible in a four-dimensional world, if they imply that there are events which are "more real" than the other space time events.

Secondly any view of "time is an illusion" does not reflect reality, because space and time are indissolubly related to each other to form a single whole, the presence of a force field in space must necessarily result in the appearance of physical properties of time caused by the motion of a body in this field. However this does not mean time is a physical property of matter or energy but is dependent upon the state of the space-time system via the force field interactions.

As physical also includes the definition "that which is measurable" time is measurable by the duration and rate of change in the system. Volume being a property which is 3d, is a physical property as it can be measured without changing the composition of the system. In a 4d view time and space are inseparable. So the correct ontology is space-time is also a property as it can be made without changing the composition of the system. As time is inseparable from space. Stating that one half of a whole is illusion while the other half is real is a contradiction.

(yes I spent some time studying the logic arguments)

I could not follow that argument, regretfully...

But before getting into details: it was next suggested that usually "presentism" implies a classical Newtonian concept of time. If that is correct, then it doesn't apply to Lorentzian 3D Space. Then, does your argument still stand, do you think?

Edited by ydoaPs
added proper quote tags and a link to the original conversation

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Yes it does, in 3d space, time is absolute. The 3d requires absolute simultaneity. This is essentially a Galilean relativity view. Transform rules x=prime{x}, t=prime{t}. You want illogical both Lorentz ether and SR use coordinate time. There is no 3d Lorentz ether. (that's the spatial component) it does have a time coordinate 4d) The cause of the time dilation merely differ between the two models as to what causes the noted time difference. Lorentz tried to model it according to the absolute frame, in which the aether is completely motionless, and the speed of light in the aether is constant in all directions. IN SR it was shown they are identical in mathematical treatment in equivalence there is no difference between Lorentz ether and SR. (we simply found that due to the symmetry between frames and identical transform rules the Ether isn't needed. The Lorentz Ether is a 4d metric not a 3d. Presentism is 3d in block not 4d. for the reasons above. You kept referring to Lorentz 3d so....( I did hint at that a few times)

Even if you compared you absolute frame to an inertial one, there is no difference when comparing two inertial frames. The treatment is identical.

You wanted to include block, but block can't distinquish between Lorentz ether or SR. As they are identical mathematically speaking, The only comparison left under block is 3d vs 4d. reversible or not reversible but it can't distinquish between this ether to SR. Identical ratio of time change in both metrics. In Lorentz ether he referred to the coordinate time as local time. But its still a 4d model.

You kept wanting block well 3d space is presentism afiak. 4d is eternalism. Particularly with the principle of relativity.

Here is another thought. Any measuring stick with invariant velocity in a vacuum could have been used. Never needed to be light we could use any massless particle.

+1 for realizing presentism didnt represent Lorentz Ether.

I know your goal is to use Block to describe the interconnect 3d space to the transforms of relativity. Block is excellent to compare 3d to 4d ontology.

but in block "absolute time" requires no synchronization procedure. The 3d is Galilean relativity.

I recommend using the combined approach Galilean relativity to SR/Lorentz transforms with block philosophies. I posted a good book in that thread that details this in the easiest format I could find. (for those math challenged readers) I'll include the same reference here

"Relativity Special, General and cosmological second edition." by Wolfgang Rindler All metrics done is shown without the need of tensors. It is probably one of the better approaches for the average reader as it doesn't require high math skills to understand nor answer the questions within the book. Its an amazing book. Quite frankly there is no need for a student to understand tensors to gain a solid understanding of relativity. Unfortunately good books that target the average reader is hard to find.

Edited by Mordred
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Here we should go step by step, for I see many issues!

Yes it does [argument still stands], in 3d space, time is absolute. The 3d requires absolute simultaneity. This is essentially a Galilean relativity view.

[..]

Here we face a first and main issue: according to Lorentz (and even Einstein in 1916), space is 3D but our time is not absolute.

3D Space as elaborated in the parallel thread means a physical entity consisting of the three spatial dimensions. 3D space is not merged with time - in contrast with Minkowski's philosophy which Einstein chose to ignore in his 1916 writing. As the concept of 3D space explicitly does not depend on the concept of time (non-withstanding mathematical correlations), the only thing that one can conclude from that label without further precision is that time is of a different physical nature than spatial dimensions.

As Celeritas put our attention to that possible misunderstanding in the other thread, I therefore labeled Lorentz's philosophy "relativistic presentism".

More tomorrow; perhaps this already suffices. However:

[..] 4d is eternalism. Particularly with the principle of relativity. [..]

Do you think that your argument in post #1 proves that relativistic presentism is incompatible with relativity?

Edited by Tim88
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Yes from a philosophical side, with experimental and support. From what I've reviewed on block conjectures. The 3D presentism ontology is incompatible with 4D spacetime. Which includes Lorentz, SR and GR.

If you are trying to write a good article for future. An approach is

Galilean relativity.

- define Rigid inertial frames

- describe absolute time.

-show velocity addition of vectors.

Relativity same sequence as above.

- homogeneity and isotropy of spacetime

- t-symmetry

-homogeneity of space (break the two apart.)

- describe proper and coordinate time.

then describe twin paradox and the garage car paradox, velocity addition

Interject the presentism vs eternalism during the above. (include some basic math examples) Define any key terms. inertial frame, covarient, symmetry, homogeneous and isotropic etc.

Edited by Mordred
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But time is somehow "inside" distance, thus "inside" space.

I mean, even for an hypothetical 1D Space to "exist", you need time.

it goes like this:

_zero dimension: it is a point.

_one dimension: it is a line. it is a point that exist in time (the T axis). It is the beginning of "existence".

_2 dimensions: it is a surface, it is a line evolving in time. It is what we call "distance". It looks to us as a line because we are embedded in time. We cannot "step outside" and have a look at what is happening. If a line "exists", if a distance "is", it means that time is already there.

The concept of a 3D space somehow "existing" independently of time is incorrect.

IMHO of course.

Which means that I disagree with this

3D Space as elaborated in the parallel thread means a physical entity consisting of the three spatial dimensions. 3D space is not merged with time - in contrast with Minkowski's philosophy which Einstein chose to ignore in his 1916 writing. As the concept of 3D space explicitly does not depend on the concept of time (non-withstanding mathematical correlations), the only thing that one can conclude from that label without further precision is that time is of a different physical nature than spatial dimensions.

And if you compare time (which is 1D) with its 1D spatial equivalent (distance or length), one may observe some similarities:

1. distance is always positive and time is also always positive. (there is no negative distance and no negative time)

2. when distance increases, time increases too (you need time to travel)

3. when you observe something at a distance, you observe it as it was some time ago.

4. distance acts as an obstacle, time too.

The fact that the relation distance/time is a universal constant for light should ring a bell. And the fact that time dilation (1D) is linked to length contraction (1D) and not to space (3D) contraction.

-------------

IOW there are some indications that distance and time could be 2 sides of the same coin. And not 2 totally different things.

----------------

And the fact (yes it sounds trivial) that when an object moves, it can move only along a path (a line), that this path is a straight line (1D) for constant motion.

When an object moves in many directions at the same time, it breaks apart.

Edited by michel123456
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But time is somehow "inside" distance, thus "inside" space.

I mean, even for an hypothetical 1D Space to "exist", you need time.

it goes like this:

_zero dimension: it is a point.

_one dimension: it is a line. it is a point that exist in time (the T axis). It is the beginning of "existence".

_2 dimensions: it is a surface, it is a line evolving in time. It is what we call "distance". It looks to us as a line because we are embedded in time. We cannot "step outside" and have a look at what is happening. If a line "exists", if a distance "is", it means that time is already there.

The concept of a 3D space somehow "existing" independently of time is incorrect.

IMHO of course.

Which means that I disagree with this

And if you compare time (which is 1D) with its 1D spatial equivalent (distance or length), one may observe some similarities:

1. distance is always positive and time is also always positive. (there is no negative distance and no negative time)

2. when distance increases, time increases too (you need time to travel)

3. when you observe something at a distance, you observe it as it was some time ago.

4. distance acts as an obstacle, time too.

The fact that the relation distance/time is a universal constant for light should ring a bell. And the fact that time dilation (1D) is linked to length contraction (1D) and not to space (3D) contraction.

-------------

IOW there are some indications that distance and time could be 2 sides of the same coin. And not 2 totally different things.

----------------

And the fact (yes it sounds trivial) that when an object moves, it can move only along a path (a line), that this path is a straight line (1D) for constant motion.

When an object moves in many directions at the same time, it breaks apart.

Similarities indeed.

But what about the relativistic triangle inequality for time and distance?

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Similarities indeed.

But what about the relativistic triangle inequality for time and distance?

Good ole Pythagoras.

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But time is somehow "inside" distance, thus "inside" space.

I mean, even for an hypothetical 1D Space to "exist", you need time.

it goes like this:

_zero dimension: it is a point.

_one dimension: it is a line. it is a point that exist in time (the T axis). It is the beginning of "existence".

_2 dimensions: it is a surface, it is a line evolving in time. It is what we call "distance". It looks to us as a line because we are embedded in time. We cannot "step outside" and have a look at what is happening. If a line "exists", if a distance "is", it means that time is already there.

The concept of a 3D space somehow "existing" independently of time is incorrect.

IMHO of course.

Which means that I disagree with this

And if you compare time (which is 1D) with its 1D spatial equivalent (distance or length), one may observe some similarities:

1. distance is always positive and time is also always positive. (there is no negative distance and no negative time)

2. when distance increases, time increases too (you need time to travel)

3. when you observe something at a distance, you observe it as it was some time ago.

4. distance acts as an obstacle, time too.

The fact that the relation distance/time is a universal constant for light should ring a bell. And the fact that time dilation (1D) is linked to length contraction (1D) and not to space (3D) contraction.

-------------

IOW there are some indications that distance and time could be 2 sides of the same coin. And not 2 totally different things.

----------------

And the fact (yes it sounds trivial) that when an object moves, it can move only along a path (a line), that this path is a straight line (1D) for constant motion.

When an object moves in many directions at the same time, it breaks apart.

Maybe this is mostly about words?

The discussion concerns physics and metaphysics - natural philosophy. In the common definitions of words, physical objects have three dimensions - the spatial dimensions. The 3 dimensions of space + the 1 dimension of time = 4 mathematical dimensions. More dimensions can be added, for example temperature. We then have 5 dimensions which can be described in a 5-dimensional mathematical "space". But temperature is also "in space"; adding more mathematical dimensions doesn't change the fact that physical space has three dimensions - that's why they are called "the spatial dimensions".

The understanding that physical bodies are three dimensional doesn't imply a claim that bodies exist without time, temperature and other properties or influences.

However that understanding does imply that time and temperature are not "hidden" fourth and fifth spatial dimensions of bodies, such that we would have 4D (or 5D) physical entities; length is physically distinct from time.

Then, concerning your first statement that 'even for an hypothetical 1D Space to "exist", you need time': it depends on how you understand "time". If time is a measure of the progress of physical processes, conceptually you don't need time for objects to exist. There is even a word for that concept: "timeless" (also the figurative expression "frozen in time". In contrast, if we would strip a spatial dimension from an object then it's not an object anymore.

Concerning the second part, studiot's remark is pertinent IMHO: there is a strong dissimilarity with spatial dimensions due to the famous minus sign, on which you have a topic yourself. And how does distance act as an obstacle?

Moreover with general relativity the universal constancy of the speed of light was abandoned; it has become a local constant instead.

Mordred wrote (numbers added by me):

1. Presentism regards the event here-now as the most real, It should be stressed that it amounts to a contradiction in terms to say that the world is four-dimensional, but for every observer only the event "here-now" is real. If the world is four-dimensional all its events are equally real otherwise it would not be four-dimensional.This shows that in space time it is impossible to have an event, representing the event "here-now", which is more "real" than the other events. Therefore, objective now of time and objective becoming are impossible in a four-dimensional world, if they imply that there are events which are "more real" than the other space time events.

2. Secondly any view of "time is an illusion" does not reflect reality, because space and time are indissolubly related to each other to form a single whole, the presence of a force field in space must necessarily result in the appearance of physical properties of time caused by the motion of a body in this field. However this does not mean time is a physical property of matter or energy but is dependent upon the state of the space-time system via the force field interactions.

3. As physical also includes the definition "that which is measurable" time is measurable by the duration and rate of change in the system. Volume being a property which is 3d, is a physical property as it can be measured without changing the composition of the system. In a 4d view time and space are inseparable. So the correct ontology is space-time is also a property as it can be made without changing the composition of the system. As time is inseparable from space. Stating that one half of a whole is illusion while the other half is real is a contradiction.

1. It's totally unclear to me what you are trying to say there.. However, the starting point isn't correct: Presentism certainly does not regard the "now" as more "real" than other times; at least, there is no reason for it, and a 3D Absolute Space concept isn't related to such ideas.

2. Time is of course not an illusion. "time" and "length" are human concepts related to observations of nature; if those observations were just illusions, we could not do physics.

3. Time is conceptually separable from space, in contrast to length (see my reply to michel here above). The concept "spacetime" is a hybrid of two distinct concepts. That's the whole point. A concept that was held by most physicists until some time after Minkowski, cannot be disproved by the fact that some people have problems understanding it.

PS. Note also that "physical" in metaphysics includes things we may infer from observations.

Now that this discussion is "sinking in", I'm flabbergasted.

The argumentation here appears to be to the effect that a pen cannot be a three dimensional object!

Did I hear that correctly??

Edited by Tim88
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"Presentism certainly does not regard the "now" as more "real" than other times; at least, there is no reason for it, and a 3D Absolute Space concept isn't related to such ideas."

Yes it does. The past is already fixed. The future does not exist. Only the present changes. Ok So your in the present. Who's present? Which observer is truly in the present? This would be no problem under absolute time.

Looking over various presentism papers, one of the most common expressions when describing presentism vs eternalism is "Presentism is incompatible with SR". Of course I have yet to find a block article WITH math to actually prove that.

transforms under absolute time. Each IF frame coordinates (x,y,z) time is absolute within this frame. Between frames time is still absolute. Frame S and $\acute{S}$ are identical and only change during the present S. Past events are already fixed and do not change.
Transforms under absolute time between frames.

$t=\acute{t},x=vt,y=\acute{y},z=\acute{z}$ This is Galilean relativity.

Eternalism answer all observers are in an equally valid present. Time isn't absolute. S does not equal $\acute {S}$ Within each IF S, time is still absolute but only within the IF frames. However between frames Time is NOT absolute.
Transforms are Lorentz transformation
$t=\gamma\acute{t}, x=\gamma\acute{x}, y=\acute{y}, z=\acute{z}$
Not sure why you can't see the difference. I kept hinting velocity addition can tell the difference. As between each of the above transformations if you take a Ship and fire a rocket. Both moving at 0.6c the final speed of the rocket will be different.

Under Galilean final speed of rocket is 1.2 c. Under Lorentz it is less than c. Which view is correct?

A) Galilean Relativity rocket final speed 1.2 c
B) Lorentz Relativity final rocket speed 0.88 c

Edited by Mordred
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The argumentation here appears to be to the effect that a pen cannot be a three dimensional object!

Did I hear that correctly??

If spacetime isn't separable, then quite frankly every object can be described under 4d. Under GR it is. We describe the object under the same 4d coordinates. All frames are equally valid. So we cannot say the object in a past frame isn't as valid as present frame. Lets try this for example. I am at elevation roughly 780 ft above sea level. I have no idea where you are but I bet your time dilated relative to my frame.

Are you less real than me? Is my measurements of a glass sitting on my table any more accurate than your measurements of the same glass? Your in my past, I'm in yours lol. Which one of us is the true present? How do you distinguish a true frame from any other frame ?

Lets go even further, if I assume my eyes is my present, every other part of my body is my past. I can't measure any object that isn't in the past. all information exchange is also limited to c. Under this understanding it makes sense to include a coordinate time doesn't it? What about length,? well we have proper length. "length measured in my rest frame" How do we track the different lengths for different frames? Use 4d coordinates. So yes every object is a 4d object in SR/GR. 3 spatial components + 1 time component.

So if it takes time for light to reach my eyes, or any signal to reach me to measure an object. How do I determine simultaneous events between frames.?

see the OP post quoted section. the list is there for Einstein synchronization. Fundamentally between frames, find the halfway point. Send a signal in both directions to a mirror at each event. If the signal arrives back at the origin at the same time, those two events are simultaneous.

Now use this procedure inside a plane flying east. Send a signal from the center of the plane, to both the front and back of the plane. The back of the plane will receive the signals before the front of the plane. Simultaneity itself is relative

Edited by Mordred
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The argumentation here appears to be to the effect that a pen cannot be a three dimensional object!

Did I hear that correctly??

Look at that pen again, Tim88. It is still the same pen, but your observation or experience of the pen now constitutes a different event than the one you referred to "before". The pen may appear to be 3-D, yet your separate observations of it happened at different coordinates in a 4-D universe. Hope this helps.

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Look at that pen again, Tim88. It is still the same pen, but your observation or experience of the pen now constitutes a different event than the one you referred to "before". The pen may appear to be 3-D, yet your separate observations of it happened at different coordinates in a 4-D universe. Hope this helps.

I think you have identified the nub of the issue. +1

What do you mean by the object?

An object, say the Earth, has definite extents in the three purely spatial dimensions.

Yet you want to set up a (4D) coordinate system whereby simultaneously (in the mathematical sense not temporal) the axes are regarded as equivalent and yet somehow the properties are different for the spatial and time derived ones.

If we identify extents in space why not in time or (ict) ?

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"Presentism certainly does not regard the "now" as more "real" than other times; at least, there is no reason for it, and a 3D Absolute Space concept isn't related to such ideas."

Yes it does. The past is already fixed. The future does not exist. Only the present changes.

(...)

I wonder, how can we know for sure that the past is fixed?

At time stamp T, we cannot have access at all the past.

The only past that we can reach a each time stamp T is the image (the information) we can get from a specific slice in Spacetime. in a spacetime diagram, it is the sum of events upon the diagonals in the past.

Concerning the inside part of the triangle, we only have the record of ancients events. But a record is not the event itself. At best, it is its image, something that we carry with us in present time.

So, how can we know that the event is "frozen" in the past if we cannot have direct access to it? If we cannot go there and confirm that yes it still exist.

Edited by michel123456
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Look at that pen again, Tim88. It is still the same pen, but your observation or experience of the pen now constitutes a different event than the one you referred to "before". The pen may appear to be 3-D, yet your separate observations of it happened at different coordinates in a 4-D universe. Hope this helps.

My experience and insight supports the conclusion that the pen is really 3D. Look at my question again: the reasoning here seems to be that since there exists a reasoning that a 4D interpretation matches observations, therefore a 3D interpretation cannot match observations.

Do I need to clarify the defect in reasoning?

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Think about what has changed between the first, second or consecutive observations of the pen (events), apart from the pen's physical appearance. That is your fourth dimension and it is an integral part of each observation/event. Think i.t.o. block universe.

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"Presentism certainly does not regard the "now" as more "real" than other times; at least, there is no reason for it, and a 3D Absolute Space concept isn't related to such ideas."

Yes it does. The past is already fixed. The future does not exist. Only the present changes. Ok So your in the present. Who's present? Which observer is truly in the present? This would be no problem under absolute time.

Looking over various presentism papers, one of the most common expressions when describing presentism vs eternalism is "Presentism is incompatible with SR". Of course I have yet to find a block article WITH math to actually prove that.[..]

Well it doesn't for me; either you're wrong about "presentism", or it doesn't necessarily apply to the 3D Absolute Space concept - just as you have your own variant of the 4D Absolute Spacetime concept.

Either way it doesn't matter, since relativity originated from the 3D Absolute Space concept as you probably know.

The compatibility of 3D Space with relativity was baked in from the very beginning, while the other concept has been added like a cuckoo egg in a bird's nest. 3D space can only be incompatible with SR if SR is self-contradictory (which I don't think).

My experience and insight supports the conclusion that the pen is really 3D. Look at my question again: the reasoning here seems to be that since there exists a reasoning that a 4D interpretation matches observations, therefore a 3D interpretation cannot match observations.

Do I need to clarify the defect in reasoning?

Think about what has changed between the first, second or consecutive observations of the pen (events), apart from the pen's physical appearance. That is your fourth dimension and it is an integral part of each observation/event. Think i.t.o. block universe.

That means that I do need to say the obvious...

If you postulate that Minkowski block universe is correct, then Lorentz ether must of course be incorrect.

However, that fact does not prove that Lorentz ether is incorrect; it's called a circular argument.

Tim,

it won't harm going through my spacetime diagrams (see the "Lost in Langevin's language" thread and 'Events popping out' thread) showing the importance of relativity of (a 3D set of) simultaneous events.

Yes, relativity of simultaneity is important - and the 3D Space interpretation is very different from the 4D Spacetime interpretation.

BTW how do you draw such nice pictures?

More later

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I don't have any absolute 4d spacetime variation. That concept is a contradiction on its own. I only compared the difference between Galilean Relativity and SR. Nothing more. That was the whole point in my argument above. 4d absolute space is a contradiction. That was precisely my entire point in my presentism argument. Several times I specifically stated. there is no 4d "absolute spacetime" mathematically that is the equivalent to Galilean relativity. Which we all know is wrong. After all these posts YOU STILL don't understand the difference??????
I even gave you velocity addition examples grrr

Look at that pen again, Tim88. It is still the same pen, but your observation or experience of the pen now constitutes a different event than the one you referred to "before". The pen may appear to be 3-D, yet your separate observations of it happened at different coordinates in a 4-D universe. Hope this helps.

Bingo all 3d objects exist at a moment in time. You have two possible treatments of time. absolute or variable. Every object has a time coordinate. However under "absolute time" you do not require a 4th axis of time to model such. You do require a 4th axis to model variable time.

For the record I really couldn't care if my view on Presentism is correct or not. I personally find little purpose in block style arguments. UNLESS it is backed up with the correct math being described by the block argument. The only math Presentism describes from what I can discern is Galiliean relativity (under the subject matter). While eternalism mathematically represents Minkowskii. So instead of declaring my view of presentism is wrong. I suggest you describe to me where it is wrong. Instead of merely posting "its wrong". Where is your counter argument to my view of presentism that is wrong? That is the purpose of philosophical debate. I present an argument. You present a counter argument. Merely stating someone is wrong, isn't an argument without adding why you feel its wrong.

Tim you obviously didn't understand a single thing I've said or you have misinterpreted everything I have stated. So instead of relying on words I'll post the math behind my statements

Galilean Transformation (frame Independence) time is absolute. What I interpret "presentism describes". Show how I am wrong on this. Don't just state it.

Transformation equations

$x=vt, y=\acute{y}, z=\acute{y}, t=\acute{t}$ note Of course it has a time dimension but it is absolute. Time does NOT ALTER ANY FRAME.

classical velocity transformation Assign U to the velocity components in S and primed S.

$\acute{U_1}=,U_1-v, \acute{U_2}=U_2, \acute{U_3}=U_3$ Notice we have no velocity component for time....not required

$(U_1,U_2,U_3)=(\frac{dx}{dt}, \frac{dy}{dt}, \frac{dz}{dt}) (\acute{U_1}, \acute{U_2},\acute{U_1})=(\acute{\frac{dx}{dt}}, \acute{U_2}=\acute{\frac{dx}{dt}}, \acute{U_3}=\acute{\frac{dx}{dt}})$

So if you have a ship moving 0.6 and the plane fires a bullet at 0.6 c under the last set of transformations the final speed of the bullet is 1.2 c. Which we know is wrong.....yet this is 3+1 dimensions However time is absolute in this case. You could call it an absolute 4D model but its pointless to do so, time doesn't add any new dimension to any velocity calculations. So all 3 velocity components are modeled under 3D. It is a 3D model.

Lorentz transformations (I have no idea how you think I believe the 3d spatial components are not valid...Obviously something you fail to understand in my posts)

$\acute{x}=\gamma{x}=x-vt, \acute{y}=y, \acute{z}=z, \acute{t},\acute{t}=\gamma(t-\frac{vx}{c^2})$ 4d velocity model. This is frame dependent. Here time does indeed add new dynamics to the velocity components. Recall my statement about preserving the $\eta_{\mu\nu}$ Euclidean space under Minkowkii ? under 3d velocity models that preservation is automatic.

time-symmetry =isotropy of time so the reverse is true with no new dynamic added due to time components so. $(t=\gamma(\acute{t}-\frac{vx}{c^2})=(\acute{t}=\gamma(t-\frac{vx}{c^2})$ Use the same substitutions as above except use the Lorentz transforms

with regards to Lorentz ether. As the Lorentz ether does not add any new velocity component to these velocity transforms IT IS NOT NEEDED.

under velocity transforms the above bullet travels at 0.88 c

is my stance clear enough yet? Absolute space=frame independent 3d, relative space=frame dependent. 4d

Edited by Mordred
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I think you have identified the nub of the issue. +1

What do you mean by the object?

An object, say the Earth, has definite extents in the three purely spatial dimensions.

Yet you want to set up a (4D) coordinate system whereby simultaneously (in the mathematical sense not temporal) the axes are regarded as equivalent and yet somehow the properties are different for the spatial and time derived ones.

If we identify extents in space why not in time or (ict) ?

Studiot, your contributions are usually interesting but sometimes a bit ambiguous. For example, here you suggest to give support to Memammal's argument, but your elaboration seems to beat it down. Can you clarify?

OK, continuing commenting on Mordred, omitting misdirected comments on "absolute time" which is a concept that by definition is not contained in "3D Space":

[..] $t=\acute{t},x=vt,y=\acute{y},z=\acute{z}$ This is Galilean relativity.

OK that solves one non-existing issue: you introduced here "Galilean relativity" as meaning t=t' which differs from standard "Galilean relativity" (meaning the PoR)! Probably you meant Newtonian relativity.

As you surely know:

- starting from Absolute Space (3D) and the PoR we will find either Newtonian relativity or Lorentzian relativity.

- Newtonian relativity uses the Galilean transformations. Time is "absolute".

- Lorentzian relativity uses the Lorentz transformations. Time is "local" or "relative".

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My latest post has been deleted without notification or motivation. Why?

Is it not allowed to refer to other threads????

In that case what must I do? Copy all the drawings I made for the other thread and drop them in this thread?

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I don't have any absolute 4d spacetime variation. That concept is a contradiction on its own. I only compared the difference between Galilean Relativity and SR. Nothing more. That was the whole point in my argument above. 4d absolute space is a contradiction. That was precisely my entire point in my presentism argument. Several times I specifically stated. there is no 4d "absolute spacetime" mathematically that is the equivalent to Galilean relativity. Which we all know is wrong. After all these posts YOU STILL don't understand the difference?????? [..]

There was at least a confusion due to your use of non-standard terminology, as discovered here above. But now it's a bit a riddle what you do argue... Anyway, continuing, maybe what follows may clear the fog (but leaving out everything related to the "Galilean" confusion that has just been cleared up):

[..] Bingo all 3d objects exist at a moment in time. You have two possible treatments of time. absolute or variable. Every object has a time coordinate. However under "absolute time" you do not require a 4th axis of time to model such. You do require a 4th axis to model variable time.

(x,y,z,t) is just as important in Newtonian physics as in Lorentzian physics for establishing events. Only the frame transformations are simpler in Newtonian physics.

[..] For the record I really couldn't care if my view on Presentism is correct or not. I personally find little purpose in block style arguments. UNLESS it is backed up with the correct math being described by the block argument. The only math Presentism describes from what I can discern is Galiliean Newtonian relativity (under the subject matter).

OK, so you use a definition of "presentism" that is incompatible with Lorentzian relativity. Case solved (in principle).

[..] instead of relying on words I'll post the math behind my statements

Galilean Transformation (frame Independence) time is absolute. What I interpret "presentism describes". Show how I am wrong on this. Don't just state it.

Transformation equations

$x=vt, y=\acute{y}, z=\acute{y}, t=\acute{t}$ note Of course it has a time dimension but it is absolute. Time does NOT ALTER ANY FRAME.

classical velocity transformation Assign U to the velocity components in S and primed S.

$\acute{U_1}=,U_1-v, \acute{U_2}=U_2, \acute{U_3}=U_3$ Notice we have no velocity component for time....not required

$(U_1,U_2,U_3)=(\frac{dx}{dt}, \frac{dy}{dt}, \frac{dz}{dt}) (\acute{U_1}, \acute{U_2},\acute{U_1})=(\acute{\frac{dx}{dt}}, \acute{U_2}=\acute{\frac{dx}{dt}}, \acute{U_3}=\acute{\frac{dx}{dt}})$

So if you have a ship moving 0.6 and the plane fires a bullet at 0.6 c under the last set of transformations the final speed of the bullet is 1.2 c. Which we know is wrong.....yet this is 3+1 dimensions However time is absolute in this case. You could call it an absolute 4D model but its pointless to do so, time doesn't add any new dimension to any velocity calculations. So all 3 velocity components are modeled under 3D. It is a 3D model.

[..]

Aha, that clarifies (perhaps) more of the misunderstanding; I hope to have better explained it here above.

Both Newton and Lorentz based their physics on a 3D physical space. Only Newton ignored some effects that later were discovered to be necessary to include, leading to a more "flexible" role for time (as well as other things, but that's not the point here).

[..]

Lorentz transformations (I have no idea how you think I believe the 3d spatial components are not valid...Obviously something you fail to understand in my posts)

$\acute{x}=\gamma{x}=x-vt, \acute{y}=y, \acute{z}=z, \acute{t},\acute{t}=\gamma(t-\frac{vx}{c^2})$ 4d velocity model. This is frame dependent. Here time does indeed add new dynamics to the velocity components. Recall my statement about preserving the $\eta_{\mu\nu}$ Euclidean space under Minkowkii ? under 3d velocity models that preservation is automatic.

time-symmetry =isotropy of time so the reverse is true with no new dynamic added due to time components so. $(t=\gamma(\acute{t}-\frac{vx}{c^2})=(\acute{t}=\gamma(t-\frac{vx}{c^2})$ Use the same substitutions as above except use the Lorentz transforms

with regards to Lorentz ether. As the Lorentz ether does not add any new velocity component to these velocity transforms IT IS NOT NEEDED.

under velocity transforms the above bullet travels at 0.88 c

is my stance clear enough yet? Absolute space=frame independent 3d, relative space=frame dependent. 4d

OK, your stance is clear enough; this was due to a mutual misunderstanding of terms!

3D Space is just a (meta)physical spatial background for matter, fields and radiation, as discussed and explained in the "grandmother" thread, where the consensus still is that measurement space cannot be mere emptiness, so that we basically have two options which you both reject.

3D (meta)physical Space is of course just as 3D measurement space included in any description of space-time, which is a 4D mathematical model. I'm pretty sure that I already explained that with a link to Einstein's description; probably you just overlooked it.

PS I here put it as (meta)physical as it's a matter of interpretation, appreciation and context if you call it "metaphysical" or "physical"; here we're somewhat at the overlap of physics and metaphysics.

Edited by Tim88
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Studiot, your contributions are usually interesting but sometimes a bit ambiguous. For example, here you suggest to give support to Memammal's argument, but your elaboration seems to beat it down. Can you clarify?

Quite simple really.

I asked what you man by an object.

Using your pen analogy think of the pen.

It has a 'length' from top to tip.

But neither the top not the tip nor any point between are a pen.

Yet these analyses treat objects as 'points' in respect of time.

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Quite simple really.

I asked what you man by an object.

Using your pen analogy think of the pen.

It has a 'length' from top to tip.

But neither the top not the tip nor any point between are a pen.

Yet these analyses treat objects as 'points' in respect of time.

I don't treat objects as points; instead I treat very small parts of an object as points. Hmm that's an interesting angle.

Fitting for this topic under philosophy is studiot's remark that objects are not points in space.

For example our consciousness has a strong "time" concept whereby signals from our ears and eyes are combined into an idea of "now"; those signals deal with delay times and intuitively we assume that the delay times are all the same.

That sense is already unprepared to combine a lightning strike with the following thunder; we must force our perception to understand that those two pieces of information happened simultaneously.

Thus our distant "now" experience is a rather simplistic and rudimentary automatic reconstruction, which of course serves very well for our daily lives and our survival.

And our consciousness itself is working on a volume of brain, so that our "now" or "present" feeling has a non-zero time interval.

For me personally that "present" feeling is a split second.

However, I think that it's a well known fact that in memory recall often the sequence of fast following events is confused.

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no I don't reject the Lorentz transformations itself.

so that we basically have two options which you both reject.

As far as the What is space thread. The volume of space, with all standard model particles removed including virtual particle production is just volume. I reject any ether aspect that many posters feel is there.

First off an absolute frame adds no time dynamic or influence for time under the Lorentz transforms. Secondly no particle ever discovered can match the criteria for an ether. A completely empty space devoid of all SM particles, Real, virtual or quasi. Is simply the volume (Granted a 4d volume). If you include no fields present as well. After all particles are excitations of a field.

Granted the zero point energy of QM tells us that due to the Heisenburg uncertainty principle. There is always a field present. Under this principle as the virtual particle pairs are virtual photons. A photon field. The Lorentz ether specifies a matter field, not a force field such as that arising from virtual photons.

Think back to the Pauli exclusion principle. Matter takes up space, (volume) this is fermionic particles. Lorentz specified a matter field. (fermionic)

QM states a force field is always present via the uncertainty principle. a force field (bosonic)

Quite simple really.

I asked what you man by an object.

Using your pen analogy think of the pen.

It has a 'length' from top to tip.

But neither the top not the tip nor any point between are a pen.

Yet these analyses treat objects as 'points' in respect of time.

Excellent.

Tim for myself spacetime is nothing more than a set of coordinates until you embed a particle field to those coordinates. There is no time particle, space particle or spacetime particle. Hence no medium until you add standard model fields/particles. I'm really not sure if your trying to find some medium like aspect to the spacetime coordinates or not.

Can the spacetime coordinates itself influence how we view a freefall particle. Yes but due to geometric relations.

One example being shown in the equivalence principle and tidal force. Two terms to study. Affine connection and Levi-Civita_connection to fully understand the last bit.

Edited by Mordred
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Today I went to a talk by Noble prize winner May-Britt Moser.

Surprisingly her talk was not only excellent and fascinating, but the information I received relates to the topic here, as our concept of "present" as a separate concept of location is put in doubt. For it connects to Michel's associations of events with space, as well as to my elaboration on how our consciousness processes events. I will try to correctly reflect her team's findings.

michel123456 said:

But time is somehow "inside" distance, thus "inside" space.

[..]

if you compare time (which is 1D) with its 1D spatial equivalent (distance or length), one may observe some similarities:

1. distance is always positive and time is also always positive. (there is no negative distance and no negative time)

2. when distance increases, time increases too (you need time to travel)

3. when you observe something at a distance, you observe it as it was some time ago.

[..]

IOW there are some indications that distance and time could be 2 sides of the same coin. And not 2 totally different things.

While such similarities somewhat explain why we associate time with spatial distance, I had the impression that the association is so strong that there should be more to it.

For why are people not similarly associating for example force with acceleration, so that they consider the two concepts as a single whole called forceacceleration? And why do we conceptually so strongly link "time" with "space" that we speak of such things as "those dates are close to each other", and "we can place those events in the year 90"?

One is easily led to think that our subconsciousness is trying to tell us that time is truly a kind of 4th spatial dimension. But there is another, much more reasonable explanation.

Earlier today I contemplated on our memory and the fact that we store experiences as events in our brain, although not very reliably, due to the way we process and store them:

[..] I think that it's a well known fact that in memory recall often the sequence of fast following events is confused.

A few hours later Prof. Moser explained that in and near to the part of our brain in which we store our memories there are "place" and "grid" cells, which form a variety of spatial maps of our surroundings, completed with "head direction" cells and even "speed cells" (with linear response!) as well as "border" cells, that serve as spatial navigation system for location and distance. This grid cell based navigation system is innate, but enforced and calibrated by means of experiences (events). Preliminary data suggest that the horizontal grid is the strongest developed, and it extends into the hippocampus where memories are stored.

Obviously (my own thinking) this is used by animals as guidance for such necessities as finding back places with food, which also benefits from time information - if only to know which memory of a place is the last, and thus the most actual map.

According to Professor Moser, spatial mnemonics work well because they actually use spatial memory; but the same area also serves for memorizing day to day events such as if you had breakfast today.

Apparently the (x,y,z) space grid in our head serves to memorize (x,y,z,t) events or snapshots, linked to associated memories.

This provides us, in addition to the above mentioned explanations, with a straightforward biological explanation for the strong associations that we make between space / distance and time. Our brain connects memories to a spatial navigation zone, so that the "when and where" is stored in a spatial mapping system.

: slight improvement of phrasing - and here's her Nobel lecture which I now quickly scanned through for checking.

Edited by Tim88
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This similarly answers the question of studiot:

[..] Yet you want to set up a (4D) coordinate system whereby simultaneously (in the mathematical sense not temporal) the axes are regarded as equivalent and yet somehow the properties are different for the spatial and time derived ones.

If we identify extents in space why not in time or (ict) ?

We intuitively know that space and time are different concepts and the aforementioned brain research established that our coordinate system is 3D, just like GPS. At first sight, that may not seem to offer an explanation for eternalism. However, we use dx/dt sensor cells for our spatial navigation, and we try to keep separate and sequentially order spatial memories that are stored on the map of the world that we built up in our head.

Edited by Tim88

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