Mordred Posted February 2, 2019 Posted February 2, 2019 (edited) tensors are functions those three are tensor fields. lets not confuse a dimension with a function. Those three fields have the same dimensions described under 4d and before you mention it yes you can create a dimension (independent variable via an arbitrary function) Edited February 2, 2019 by Mordred
studiot Posted February 2, 2019 Posted February 2, 2019 1 hour ago, Mordred said: tensors are functions those three are tensor fields. lets not confuse a dimension with a function. Those three fields have the same dimensions described under 4d and before you mention it yes you can create a dimension (independent variable via an arbitrary function) All functions are dependent. That is built into the definition of a function. But not all functions are variable since there exists such a thing as a constant function. It is independence we are talking about.
Mordred Posted February 2, 2019 Posted February 2, 2019 (edited) Neither of us disagree with the definition of dimension (including higher dimensions) being an independent variable, so lets not sidelight this thread on all the possible case scenarios...neither of us disagree on how to define a field either for that matter lol. You certainly know as one example the radial basis function only depends on the distance from the origin and can be treated as an independent variable on a x,y graph. Though I'm still waiting to see if the OP is going to respond to some of the raised points of this thread Edited February 2, 2019 by Mordred
studiot Posted February 2, 2019 Posted February 2, 2019 46 minutes ago, Mordred said: Neither of us disagree with the definition of dimension (including higher dimensions) being an independent variable, so lets not sidelight this thread on all the possible case scenarios...neither of us disagree on how to define a field either for that matter lol. Though I'm still waiting to see if the OP is going to respond to some of the raised points of this thread I'm off to an organ recital, raising money for another scanner at the District Hospital. Now that Eise's response on Newton is in I plan to start a new thread, developing the modern view of N1 - N3, as promised. I will post it as and when. It has implications connected with the points of dimension we are discussing here.
Mordred Posted February 2, 2019 Posted February 2, 2019 good plan lets pull this to a different thread as its good learning for other readers at the least.. particularly when it comes to the numerous misconceptions of higher dimensions and compactifying those higher dimensions etc. Good luck on your fund raiser
koti Posted February 2, 2019 Posted February 2, 2019 10 minutes ago, studiot said: I'm off to an organ recital, raising money for another scanner at the District Hospital. You can raise money with those?
beecee Posted February 2, 2019 Posted February 2, 2019 On 2/1/2019 at 4:33 PM, argo said: Still nothing to do with the issues at hand, bored now. The pop science terminology "time flows" simply describes the "distance" if you like between two specific events. It is not wrong per se but describes in layman's terms, a notoriously difficult concept to describe, even for professionals. Time like space, exists...it stops everything from happening together. Something does not need to be physical to be real. It just needs to be "effective" on our perception of events and observations. eg: Is a magnetic field real? The question that needs to be asked is, "is time fundamental?" https://www.youtube.com/watch?v=FVINOl0Ctfk Now those answers may not satisfy you, but they are the best science has at this time. Or you can go with my previous definition......Time exists, It is the fourth dimension along with space and its three dimensions. Time imho is not movement as such, but more correctly, movement occurs in time and enables us to measure via clocks, the duration between specific events. If all atomic movement ceased, if the universe stopped expanding, time would continue to pass/flow in a forward direction. If the universe started contracting, time flow would not reverse, but continue on in that direction which the late Stephen Hawking called the cosmological arrow of time
Mordred Posted February 2, 2019 Posted February 2, 2019 (edited) Oh man don't get me started on defining the term physical lmao this thread can definitely take a strong tangent on that term. distance and time are both physical properties... hint hint as to how difficult the term "physical can apply" ? You gave the EM field as an example. Each measurable quantity is a physical quantity. (physical does not mean materialistic or corpuscular) Edited February 2, 2019 by Mordred
StringJunky Posted February 2, 2019 Posted February 2, 2019 2 hours ago, Mordred said: Oh man don't get me started on defining the term physical lmao this thread can definitely take a strong tangent on that term. distance and time are both physical properties... hint hint as to how difficult the term "physical can apply" ? You gave the EM field as an example. Each measurable quantity is a physical quantity. (physical does not mean materialistic or corpuscular) 'Physical' pertains to physics.
studiot Posted February 2, 2019 Posted February 2, 2019 15 minutes ago, StringJunky said: 'Physical' pertains to physics. And I thought it was something to do with corona 3
Orion1 Posted February 3, 2019 Posted February 3, 2019 Physics: The branch of science concerned with the nature and properties of matter and energy. The subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms. The physical properties and phenomena of something. Physical: Relating to things perceived through the senses as opposed to the mind; tangible or concrete. "everything physical in the universe" We are defining the Original Posters semantic definitions?
studiot Posted February 3, 2019 Posted February 3, 2019 (edited) 16 hours ago, koti said: You can raise money with those? Yes it is a good plan really. The Church provides the instrument and the venue for free. The renouned organist comes down from Bristol Cathedral and plays for free. The volunteers organise for free. So at £5 a ticket it is all profit. The only fly in the ointment was the weather which kept some away, reducing the overall take. Lot's of events like this are how the 'Friends of the Hospital' have just raised over £1million for a third MRI scanner in just over a year. This is a much better way than the sort of problems Daedalus is facing. Edited February 3, 2019 by studiot
argo Posted February 3, 2019 Author Posted February 3, 2019 · Resident Expert · · Resident Experts · · 1102 · 6323 posts · Posted Thursday at 08:48 AM (edited) Time is simply a measure of rate of change of events or duration it isn't a substance or material that flows. Quick simple and easy... Under relativity how one measures the rate of change will depend on the observer measuring the event. All too often people like to think of time as more than a property of a system or state. It is simply a measure of rate or duration. The Universe itself doesn't care how we measure or describe it. Time will continue without our measurements, as change will always occur. How we describe rate of change is irrelevant to the process undergoing change. Edited Thursday at 08:59 AM by Mordred I would point out that a scientific publication speculating time actually flows in the real world is a publication that exists and one I have presented; pretending this description doesn’t refer to time in the real world is just another transparent trick. Time in physics is a mathematical construct Mordred, it is simply a measure of linear motion as described by “what clocks read”, a clock reads only linear motion not velocity or non-linear motion so your statement that time measures rate of change is not even as right as a broken clock which gets it right twice a day. In linear motion, the directions of all the vectors describing the system are equal and constant which means the objects move along the same axis at a constant rate and do not change direction just like the imaginary motion of time in a clock. You do get it right once though Mordred, when all the vectors are equal and constant it is a measure of that one rate of change “that clocks read”. You are an expert at ignoring the issues and getting it almost completely wrong but I am yet to see how you profit by restating the very confusion that I went to such great lengths to sort out. Your trick is to ignore the published scientific view that implies time in the real world flows from the past, through the present to the future and only acknowledge what you refer to as time in a strictly mathematical sense. I was asked for a two line summary but perhaps what is needed is a response to just one philosophical question, does now (in the real world) exist? Mordred’s own philosophy is now doesn’t exist in the real world at all, isn’t it a bit one-eyed and arbitrary to then deny me a reply as though I chose to philosophize? I don’t know why I was trashed, perhaps because I challenged this scared philosophy but I will answer my critics one by one in my own time, it won’t be quick, simple and easy, it will be exhausting, complicated and difficult because these are the issues and these are your tricks. POSTED TRASH STYLE -1
swansont Posted February 3, 2019 Posted February 3, 2019 42 minutes ago, argo said: Time is simply a measure of rate of change of events or duration it isn't a substance or material that flows. Quick simple and easy... Under relativity how one measures the rate of change will depend on the observer measuring the event. All too often people like to think of time as more than a property of a system or state. It is simply a measure of rate or duration. The Universe itself doesn't care how we measure or describe it. Time will continue without our measurements, as change will always occur. How we describe rate of change is irrelevant to the process undergoing change. Edited Thursday at 08:59 AM by Mordred I would point out that a scientific publication speculating time actually flows in the real world is a publication that exists and one I have presented; pretending this description doesn’t refer to time in the real world is just another transparent trick. What scientific publication? Where did you present it? I only see links to Wikipedia. Quote Time in physics is a mathematical construct Mordred, it is simply a measure of linear motion as described by “what clocks read”, a clock reads only linear motion not velocity or non-linear motion so your statement that time measures rate of change is not even as right as a broken clock which gets it right twice a day. A clock reads linear motion? Please explain. Quote In linear motion, the directions of all the vectors describing the system are equal and constant which means the objects move along the same axis at a constant rate and do not change direction just like the imaginary motion of time in a clock. Please explain what you mean that objects move along the same axis. How does that apply to a clock? Quote You do get it right once though Mordred, when all the vectors are equal and constant it is a measure of that one rate of change “that clocks read”. You are an expert at ignoring the issues and getting it almost completely wrong but I am yet to see how you profit by restating the very confusion that I went to such great lengths to sort out. Your trick is to ignore the published scientific view that implies time in the real world flows from the past, through the present to the future and only acknowledge what you refer to as time in a strictly mathematical sense. Again, where did you find this “published scientific view”? Please share the link to the scientific publication. Quote I was asked for a two line summary but perhaps what is needed is a response to just one philosophical question, does now (in the real world) exist? Mordred’s own philosophy is now doesn’t exist in the real world at all, isn’t it a bit one-eyed and arbitrary to then deny me a reply as though I chose to philosophize? I don’t know why I was trashed, perhaps because I challenged this scared philosophy but I will answer my critics one by one in my own time, it won’t be quick, simple and easy, it will be exhausting, complicated and difficult because these are the issues and these are your tricks. POSTED TRASH STYLE You’re being subjected to rigor. It’s part of the process.
Mordred Posted February 3, 2019 Posted February 3, 2019 (edited) As Swansont mentioned Wiki isn't an authority on physics neither is its definitions. Particularly since the reference that Wiki used in this case is from a process control engineering handbook....its unfortunate so many other websites blindly use it as an immediate reference. That however does not make it always correct or accurate. Wiki would have been better off in this case to pick up a physics textbook for a reference.... If you can provide a professional peer reviewed support of your definition then please feel free to provide it. I certainly do not believe in the philosophy you described above, I leave philosophy to others. The use of the definition "time is what a clock reads" is arbitrary as a measurement tool does not define what it is measuring. Particularly with the issues of variable time under GR. Any process that has a consistent interval can measure the passing of time. That however does not DEFINE time... Edited February 3, 2019 by Mordred
studiot Posted February 3, 2019 Posted February 3, 2019 (edited) Argo 2 hours ago, argo said: POSTED TRASH STYLE As far as I can see you posted essentially the same subject a few months ago and entered into a 5 page battle, posting statements that confused everybody and eventually abandoned that thread of yours without conclusion. In order to try to help your understanding along I suggest you take a long read of this extract from the Stanford Encyclopedia of Philosophy about Newton's definitions of Time. Take particular note of the section I highlighted; it says much the same thing as I posted in my original reply to this trhead, wo which you have not responded. There is much wisdom to be had from this text. Quote Stanford Encyclopedia of Philosophy 4. “Definitions” and absolute space, time, and motion The Principia opens with a section called “Definitions” that includes Newton's discussion of absolute space, time, and motion. No part of the Principia has received more discussion by philosophers over the three centuries since it was published. Unfortunately, however, a tendency not to pay close attention to the text has caused much of this discussion to produce unnecessary confusion.[18] The definitions inform the reader of how key technical terms, all of them designating quantities, are going to be used throughout the Principia. In the process Newton introduces terms that have remained a part of physics ever since, such as mass, inertia, and centripetal force. The emphasis in every one of the definitions is on how the designated quantity is to be measured, as illustrated by the opening definition: “Quantity of matter [or mass] is a measure of matter that arises from its density and volume jointly.” (Because a primary measure of density was then specific gravity, no circularity arises here.) Newton distinguishes among three ways of quantifying centripetal forces: the absolute quantity, which corresponds to what we would call the field strength of a central force field; the accelerative quantity, which “is the measure of this force that is proportional to the acceleration generated in a given time;” and the motive quantity, which is the measure of the force proportional to what we would call the change in linear momentum in a given time. It is important to recognize that, in calling the referents of the defined terms “quantities,” Newton is assigning them to the ontological category of quantity in Aristotle's sense. Thus force and motion are quantities that have direction as well as magnitude, and it makes no sense to talk of forces as individuated entities or substances. Newton's laws of motion and the propositions derived from them involve relations among quantities, not among objects. In place of “no entity without identity,” we have “no quantity without definite proportions;”[19] and the demand on measurement is to supply values that unequivocally yield an adequate approximation to these definite proportions. Immediately following the eight definitions is a Scholium on space, time, and motion. One source of confusion in the literature on this scholium is not paying attention to the primary distinction Newton is drawing, which is between “absolute, true, mathematical” motion versus “relative, apparent, common” motion. The naive distinction between true and apparent motion was, of course, entirely commonplace. Moreover, Newton is scarcely introducing it into astronomy. Ptolemy's principal innovation in orbital astronomy — the so-called bi-section of eccentricity — entailed that half of the observed first inequality in the motion of the planets arises from a true variation in speed, and half from an only apparent variation associated with the observer being off center. Similarly, Copernicus's main point was that the second inequality — that is, the observed retrograde motions of the planets — involved not true, but only apparent motions. And the subsequent issue between the Copernican and Tychonic system concerned whether the observed annual motion of the Sun through the zodiac is a true or only an apparent motion of the Sun. So, what Newton is doing in the scholium on space and time is not to introduce a new distinction, but to explicate with more care a distinction that had been fundamental to astronomy for centuries. The distinctions between “absolute, true, and mathematical” and “relative, apparent, and common” time and space are the conceptual basis Newton employs in laying out the corresponding distinction for motion. He says, “relative, apparent, and common time is any sensible and external measure (precise or imprecise) of duration by motion,” adding a parallel point about absolute space. He points out that the distinction between absolute and relative time has long been part of astronomy insofar as astronomers have long introduced corrections (via the equation of time) to the natural day “in order to measure celestial motions on the basis of a truer time,” and he raises the possibility of there being “no uniform motion by which time may have an exact measure.” Absolute motion is defined as change from one place in absolute space to another. “But since these parts of space cannot be seen and cannot be distinguished from one another by our senses, we use sensible measures in their stead,” adding “it is possible that there is no body truly at rest to which places and motions may be referred” [P, 410]. In short, both absolute time and absolute location are quantities that cannot themselves be observed, but instead have to be inferred from measures of relative time and location, and these measures are always only provisional; that is, they are always open to the possibility of being replaced by some new (still relative) measure that is deemed to be better behaved across a variety of phenomena in parallel with the way in which sidereal time was deemed to be preferable to solar time. Notice here the expressed concern with measuring absolute, true, mathematical time, space, and motion, all of which are identified at the beginning of the scholium as quantities. The scholium that follows the eight definitions thus continues their concern with measures that will enable values to be assigned to the quantities in question. Newton expressly acknowledges that these measures are what we would now call theory-mediated and provisional. Measurement is at the very heart of the Principia. It pervades the definitions and scholium on space and time precisely because the primary point of this section is to spell out (in Howard Stein's words) “the empirical content of a set of theoretical notions” [Stein, 1967, 281]. Accordingly, while Newton's distinctions between absolute and relative time and space provide a conceptual basis for his explicating his distinction between absolute and relative motion, absolute time and space cannot enter directly into empirical reasoning insofar as they are not themselves empirically accessible. In other words, the Principia presupposes absolute time and space for purposes of conceptualizing the aim of measurement, but the measurements themselves are always of relative time and space, and the preferred measures are those deemed to be providing the best approximations to the absolute quantities. Newton never presupposes absolute time and space in his empirical reasoning. Motion in the planetary system is referred to the fixed stars, which are provisionally being taken as an appropriate reference for measurement, and sidereal time is provisionally taken as the preferred approximation to absolute time. Moreover, in the corollaries to the laws of motion Newton specifically renounces the need to worry about absolute versus relative motion in two cases: Edited February 3, 2019 by studiot 1
Strange Posted February 3, 2019 Posted February 3, 2019 2 hours ago, argo said: I would point out that a scientific publication speculating time actually flows in the real world is a publication that exists and one I have presented You have not referenced any publication. Perhaps you forgot . 2 hours ago, argo said: Time in physics is a mathematical construct Mordred, it is simply a measure of linear motion as described by “what clocks read”, a clock reads only linear motion not velocity or non-linear motion so your statement that time measures rate of change is not even as right as a broken clock which gets it right twice a day. A clock doesn't measure linear motion. It measures time, which doesn't require motion. The more accurate clocks are, the less motion they have. 2 hours ago, argo said: Your trick is to ignore the published scientific view that implies time in the real world flows from the past, through the present to the future and only acknowledge what you refer to as time in a strictly mathematical sense. Where is this published? Please provide a link or a reference. 3 hours ago, argo said: I was asked for a two line summary but perhaps what is needed is a response to just one philosophical question, does now (in the real world) exist? That is not a scientific question. Time exists in our models and that is all science has to say on the matter.
beecee Posted February 3, 2019 Posted February 3, 2019 6 hours ago, argo said: · I don’t know why I was trashed, perhaps because I challenged this scared philosophy but I will answer my critics one by one in my own time, it won’t be quick, simple and easy, it will be exhausting, complicated and difficult because these are the issues and these are your tricks. POSTED TRASH STYLE You challenged nothing and have failed to answer your critics, instead just repeating your trashy posting style. The prime fallacy you present of course is that time needs any motion at all. It doesn't.
StringJunky Posted February 3, 2019 Posted February 3, 2019 (edited) On 2/1/2019 at 8:00 AM, Strange said: This is a straw man argument. The concept that time "flows" is a psychological (or maybe philosophical) one, nothing to do with physics. The definition of time as what clocks measure is in line with other definitions of fundamental properties. Spatial distance is what a ruler measures. Mass is the measured resistance to acceleration. Energy is just a property we measure (and find it is conserved) we can't say what it "is". That is the nature of fundamental properties: they can't be defined in terms of other things. You can say that other things are related to these fundamental properties, like change can be used to measure time or that energy can do work, but this doesn't tell you any more about what these things are. (The fact that change is a measure of time might be what gives rise to the illusion of time "flowing"). I think the idea of time flowing is a consequence of our biology. It gives order and direction to our behavior; like putting signs up along a road. Edited February 3, 2019 by StringJunky
argo Posted February 4, 2019 Author Posted February 4, 2019 swansont · Evil Liar (or so I'm told) · · Moderators · · 6709 · 41232 posts · Location: Washington DC region · Posted Thursday at 09:01 AM If you really think this is unique to time, how about defining length, without any circular references. Perhaps it’s what a ruler measures? Length is a measurement, it is only ever a mathematical construct, the definition and description of time I posted say there is circular references in the mathematical construct but you miss the point entirely that this just proves that the constructed definition of time that flows and can be measured cannot be superimposed over a description for time in the real world like it is. There is a published description that describes time as existing and flowing here in the real world, it states time is the indefinite progress of existence from the past, through the present to the future. This philosophy that time exists as a fourth dimension and flows are proven false if the circular reference is acknowledged. You’re a sniper Swansont, you don’t give away any of your positions but you do add to the confusion. And if your concern is about physics having a mathematical construct that doesn’t physically exist, I fear you haven’t been exposed to much physics. You are imagining me having this concern, quote me instead of just making stuff up. Mathematical constructs don’t exist in the real world which was the whole complaint I made about time in physics being used to describe time in the real world, this is a designed trick. Exhausting, complicated and difficult, playing tricks and avoiding the issues. one post at a time 1 -2
swansont Posted February 4, 2019 Posted February 4, 2019 38 minutes ago, argo said: If you really think this is unique to time, how about defining length, without any circular references. Perhaps it’s what a ruler measures? Length is a measurement, it is only ever a mathematical construct, the definition and description of time I posted say there is circular references in the mathematical construct but you miss the point entirely that this just proves that the constructed definition of time that flows and can be measured cannot be superimposed over a description for time in the real world like it is. Again I will point out (as others have as well) that the definition of time does not say it flows. That is a popular description of time, not its definition. My point was that you are objecting to something related to time as if it were unique to time, and it is not. Quote There is a published description that describes time as existing and flowing here in the real world, it states time is the indefinite progress of existence from the past, through the present to the future. You have not provided a link to it. I will not accept this as a valid point until you do. Quote This philosophy that time exists as a fourth dimension and flows are proven false if the circular reference is acknowledged. Again, you seem to be treating the circular definition as if it were unique to time. I guess length doesn't exist, either. Is that your position? And I thought we were discussing physics, rather than philosophy. Quote You’re a sniper Swansont, you don’t give away any of your positions but you do add to the confusion. It's your thread. You're the one who has to justify your proposal. Trying to shoot it down is not only allowed, it's what should be expected. Quote And if your concern is about physics having a mathematical construct that doesn’t physically exist, I fear you haven’t been exposed to much physics. You are imagining me having this concern, quote me instead of just making stuff up. Mathematical constructs don’t exist in the real world which was the whole complaint I made about time in physics being used to describe time in the real world, this is a designed trick. It's a conclusion based on what you have written. But if that's not what your concern is, then I fear you have done a poor job of explaining yourself. Why does it matter of the construct physically exists in the real world? Does a hole physically exist? What's it made of? Can you hand me some tall? How about a bucket of red?
Mordred Posted February 4, 2019 Posted February 4, 2019 You know what I find amusing is that the OP is defending his own personal definitions (time flows) that he also argues are incorrect based on circular logic.
Strange Posted February 4, 2019 Posted February 4, 2019 2 hours ago, argo said: swansont · Evil Liar (or so I'm told) · · Moderators · · 6709 · 41232 posts · Location: Washington DC region · Posted Thursday at 09:01 AM Please learn to use the "Quote" function. It makes it much easier to see what you are responding to. 2 hours ago, argo said: Length is a measurement, it is only ever a mathematical construct, the definition and description of time I posted say there is circular references in the mathematical construct but you miss the point entirely that this just proves that the constructed definition of time that flows and can be measured cannot be superimposed over a description for time in the real world like it is. Anything you can say about length being a "measurement" or a "mathematical construct" applies equally to time. Similarly, the only person saying that time flows is YOU. So you are just arguing with yourself, which is kinda pointless. 2 hours ago, argo said: There is a published description that describes time as existing and flowing here in the real world, If that publication existed (outside your imagination) you would be able to tell us what it was. As you can't, I am going to assume it doesn't exist. 2 hours ago, argo said: Mathematical constructs don’t exist in the real world which was the whole complaint I made about time in physics being used to describe time in the real world, this is a designed trick. The same is true of length. Or mass. Or electric charge. We have mathematical descriptions of these things. But they are not the same as the things themselves. But any discussion of "the things themselves" is philosophy, not science. 2 hours ago, argo said: Exhausting, complicated and difficult, playing tricks and avoiding the issues. Please stop doing that then.
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