What is the actual definition of the position of an object?

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quantum philosopher
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TL;DR Summary
Definition of position
We always talk of position of objects but what is the actual definition of position ? If someone say that it is the "space coordinate or set of coordinates where the object is located" then he have to define also what is meant by located . Is position just a value or set of values that we get when the object interact or exert force on us ? For example the coulomb's force on an observer is measured by the observer himself . The direction and magnitude of force give a value denoted by r in the expression of coulomb's force . That is considered as the position vector . So according to me interactions are more fundamental than position.
 
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  • #2
Where a thing is. You can specify it in terms of distances and directions from some fixed point if you want.
 
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  • #3
quantum philosopher said:
TL;DR Summary: Definition of position

We always talk of position of objects but what is the actual definition of position ?
In practical terms, spatial positioning of one body respect to another, or to a chosen point of reference, is a valuable tool.
Please, see:
https://en.wikipedia.org/wiki/Triangulation
 
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  • #4
A "position" is the set of coordinates that represent the place where a particular point is in some coordinate system.
 
  • #5
Lnewqban said:
Repeated application of triangulation builds up a network of directions and distances with different origin points. You can then infer directions and distances from points in the network to others where you don't directly know the answer, and those inferences check out when tested in the real world.
 
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  • #6
rcatalang said:
A "position" is the set of coordinates that represent the place where a particular point is in some coordinate system.
I would say coordinates are a good way of labelling points, but since I can specify the position of something without using coordinates (e.g. "it's halfway between those two objects") then I don't think coordinates can really be part of the definition of position.
 
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  • #7
quantum philosopher said:
TL;DR Summary: Definition of position

what is the actual definition of position ? …
This is not nearly as difficult as you pretend.

On the theoretical side, take any tetrad and integrate the timelike vector field. Those integral curves are the positions.

On the experimental side, devices for measuring position can easily be purchased.

With a clear theoretical meaning and a clear experimental meaning and a clear mapping between the two, from a scientific perspective all is clear. Even if philosophers like to pretend otherwise.
 
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  • #8
Position is a interesting term but not actually very complicated one.

It is simply the location a object is at. Coordinates can specifically tell you the location also in more general physics the (X,Y) axis

You can add the direction if moving or position facing is the object has a face, but I don't exactly understand the question?

Position is just a objects location in any dimensional plane.
 
  • #9
quantum philosopher said:
TL;DR Summary: Definition of position

We always talk of position of objects but what is the actual definition of position ?
How far away, and in what direction, from the origin.
 
  • #10
Dale said:
This is not nearly as difficult as you pretend.

On the theoretical side, take any tetrad and integrate the timelike vector field. Those integral curves are the positions.

On the experimental side, devices for measuring position can easily be purchased.

With a clear theoretical meaning and a clear experimental meaning and a clear mapping between the two, from a scientific perspective all is clear. Even if philosophers like to pretend otherwise.
Can you ever perceive position of an object without interaction ? If no then it is just a property of interaction with the object and not object itself . If we continuously observe an object in time we see that the curve of location or position with respect to time is continuous with respect to time always . This somehow created a sense in the mind that the object is always occupying a location whether we observe it or not and thus it is fundamental and so the question appears obvious and not difficult . So what tetrad and timelike vector field you mean ?
 
  • #11
Mister T said:
How far away, and in what direction, from the origin.
Then how do you define far away ? Also consider that can you define position with interaction.
 
  • #12
Field physics said:
Position is a interesting term but not actually very complicated one.

It is simply the location a object is at. Coordinates can specifically tell you the location also in more general physics the (X,Y) axis

You can add the direction if moving or position facing is the object has a face, but I don't exactly understand the question?

Position is just a objects location in any dimensional plane.
I said to also define location if you use that term
 
  • #13
rcatalang said:
A "position" is the set of coordinates that represent the place where a particular point is in some coordinate system.
What do you mean by an object "is in". Observations only give a sense of "is in" .So I don't think that we can define position without observation
 
  • #14
quantum philosopher said:
Can you ever perceive position of an object without interaction ?
No.
quantum philosopher said:
If no then it is just a property of interaction with the object and not object itself .
While there is some uncertainty in any measurement, this doesn't change the meaning of 'location' or 'position' of an object.
quantum philosopher said:
If we continuously observe an object in time we see that the curve of location or position with respect to time is continuous with respect to time always . This somehow created a sense in the mind that the object is always occupying a location whether we observe it or not and thus it is fundamental and so the question appears obvious and not difficult .
Yes, for macroscopic objects this is true. A soccer ball doesn't transport itself fifty yards towards the goal if everyone stops looking at it. For relatively isolated small systems of particles things get a bit more complicated.
quantum philosopher said:
Then how do you define far away ? Also consider that can you define position with interaction.
He didn't say "far away", he said, "how far away...". That is, "the distance from some point to the object", not "the object is far away".
 
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  • #15
quantum philosopher said:
So I don't think that we can define position without observation
Your brain is just above the point half way between your ears.

I have no direct observation of either of your ears nor your brain. But my statement of position is correct.
 
  • #16
@quantum philosopher It's not clear what you're wanting. We can give you a precise mathematical definition of position, if that's what you're after. But you seem to have some sort of philosophical idea that's floating around too. Can you clarify what kind of answer you'd like?
 
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  • #17
quantum philosopher said:
Can you ever perceive position of an object without interaction ? If no then it is just a property of interaction with the object and not object itself .
Using your same logic, I can write:
Can you ever perceive the [intelligence] of [a person] without [you ever interacting with them]? If no, then [intelligence] is just a property of interaction and not [of the person themselves].
Are you solipsistic about both particles and people?
 
  • #18
Drakkith said:
@quantum philosopher It's not clear what you're wanting. We can give you a precise mathematical definition of position, if that's what you're after. But you seem to have some sort of philosophical idea that's floating around too. Can you clarify what kind of answer you'd like?
OK now I will be very specific . Define what is position (in any way that you want)
 
  • #19
Ibix said:
Your brain is just above the point half way between your ears.

I have no direct observation of either of your ears nor your brain. But my statement of position is correct.
You know brain is attached to a body between the ears so only after "interacting or observing" my ears you can get position values for my ears and then calculate my brain position .
 
  • #20
renormalize said:
Using your same logic, I can write:
Can you ever perceive the [intelligence] of [a person] without [you ever interacting with them]? If no, then [intelligence] is just a property of interaction and not [of the person themselves].
Are you solipsistic about both particles and people?
I think yes . Every observable is the property ofobservation .
 
  • #21
quantum philosopher said:
I think yes . Every observable is the property ofobservation .
Well, at least you are consistent. But you then have to explain what is gained by attributing properties to interactions, rather than properties being intrinsic to particles and people.
 
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  • #22
renormalize said:
Well, at least you are consistent. But you then have to explain what is gained by attributing properties to interactions, rather than properties being intrinsic to particles and people.
It is not about gain it is about logic and definition . Some quantities are always same when measured like mass(as far as I know) , charge , intelligence(of a person) , etc . Those properties you are calling intrinsic properties because they don't appear to be dependent on observation. But you don't get those constant values unless you observe .
 
  • #23
quantum philosopher said:
Then how do you define far away ?
We can play that game forever.

How do you define define?
How do you define how?

quantum philosopher said:
Also consider that can you define position with interaction.
How do you define interaction.

quantum philosopher said:
OK now I will be very specific . Define what is position (in any way that you want)
We've already done that!

How do you define specific? Seems you are now being less specific? And silly!
 
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  • #24
quantum philosopher said:
But you don't get those constant values unless you observe .
So are you asserting that a tree falling in the forest makes no sound unless someone is present there to hear it?
 
  • #25
The fundamental confusion here is between position as a mathematical concept, which is well-defined in whatever mathematical model is being used; and, position as a physical measurement. If we consider the measurements of position of planets, stars and other galaxies, we can see that their position is inferred from one or more local observations here on Earth. One test of physics is that when we put those inferences together with the mathematical model, the predictions of the model are satisfied.
 
  • #26
renormalize said:
So are you asserting that a tree falling in the forest makes no sound unless someone is present there to hear it?
No I never asserted that . Events and phenomenon occur irrespective of whether there is an external observer or not . Events and observables are not the same thing thus noise(phenomenon ) due to a falling(event) tree cannot be compared with value of observable due to observation .
 
  • #27
quantum philosopher said:
Events and phenomenon occur irrespective of whether there is an external observer or not .
Suppose an body in motion passes through a specific spatial position at a specific time: in your view, does that constitute an event, whether there is an external observer or not?
 
  • #28
quantum philosopher said:
Those properties you are calling intrinsic properties because they don't appear to be dependent on observation. But you don't get those constant values unless you observe .
These properties do not depend on observation, and we get their values by observation.
There is no contradiction here and no reason to say but.
 
  • #29
renormalize said:
Suppose an body in motion passes through a specific spatial position at a specific time: in your view, does that constitute an event, whether there is an external observer or not?
The body passes through a specific position at a specific time that means an observer is continuously observing that body and at some particular time he gets that particular value of position which you are talking about . Thus it is absolutely an event ( getting specific value of position by that observer) . Irrespective of another observer observing the body and first observer , first observer will see the body passing through that position.
 
  • #30
quantum philosopher said:
The body passes through a specific position at a specific time that means an observer is continuously observing that body and at some particular time he gets that particular value of position which you are talking about .
Your reasoning is still unclear to me. Can you answer this: do you, or do you not, believe that a random planetoid in the asteroid-belt follows a well-defined orbital trajectory as a function of time, regardless of whether that particular body has ever been observed by anyone or anything (such as astronomers, space probes or even aliens)?
 
  • #31
renormalize said:
Your reasoning is still unclear to me. Can you answer this: do you, or do you not, believe that a random planetoid in the asteroid-belt follows a well-defined orbital trajectory as a function of time, regardless of whether that particular body has ever been observed by anyone or anything (such as astronomers, space probes or even aliens)?
I only believe that an observer or position detector will give the trajectory as predicted by laws of motion . Think of position as just a value given by a position detector with respect to time. Then there will be no meaning of position without observer
 
  • #32
quantum philosopher said:
OK now I will be very specific . Define what is position (in any way that you want)
That is literally the opposite of what I asked. This thread is going nowhere. Thread locked.
 
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