Is Time Truly a Dimension or Something Else Entirely?

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is time a "dimension"

I have been trying to figure this one out for some time now. I have read much on the subject, but it seems to be dealt with in such a cavalier fashion. So, here goes...

We speak of space-time as if it were something packaged. I have a problem with this. Let me list the difficulties I have:

Concerning position:
1. In physical 3-space, I can position an object anywhere I like, relative to an arbitrary (0,0,0) position.
2. After any arbitrary operation, the objects position can be anywhere in 3-space, including any previous position.
3. The object may be placed in + or - position relative to the origin.
4. Any operation changing the objects position instantiates or necessitates the creation of time. Without a change of position, there is no need to speak of time.
5. Changes in position may be made with an infinity of possible velocities and accelerations, positing "time"
Concerning time:
A. I have no control over the timing of an event - it always occurs at the present - dissimilar from item 1.
B. I can never reuse the present or a previous time - dissimilar from item 2.
C. Causality forces only forward motion in time - dissimilar from item 3.
D. The flow of time does not instantiate a change of position - dissimilar from item 4.
E. Time does not seem to have various rates of flow (relativity excepted) - dissimilar from item 5.

It would seem, then, that time is only superficially similar to 3-space, in that it operates in some mathematical models in a fashion similar to the spatial distances. However, A-E behaviors are distinctly different from 1-5 behaviors.

So, how can we group time with space? It would seem time is something wholly different, and perhaps not of the same substance.

Any help?
 
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None of those things are relevant.

The term http://en.wikipedia.org/wiki/Dimension" has a specific mathematical meaning: "In mathematics the dimension of a space is roughly defined as the minimum number of coordinates needed to specify every point within it". A minimum of four coordinates are needed to specify every event in spacetime, so spacetime is a four-dimensional space. The fact one coordinate is different from the other three does not make it any less of a coordinate.

Having said that, you are absolutely correct that time is fundamentally different than space as can be seen from the Minkowski metric: ds²=-c²dt²+dx²+dy²+dz². Time is still a dimension, but that minus sign definitely singles it out.
 
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For any person, there's always a time dimension that is separate from his space dimensions. But what is time for me may be space for you, which is why we imagine time and space together as spacetime.
 
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We could define spacetime to be the set \mathbb R^4 and let functions of the form C:\mathbb R\rightarrow\mathbb R^4 represent an object's motion, even if we knew nothing about special relativity. It's this definition that turns time into a "dimension". Time is a dimension in that model, for the reasons DaleSpam explained.

In this model of spacetime, "space" is a subset of spacetime such that all the members of it are simultaneous (i.e. have the same time coordinate). The difference between SR and pre-relativistic physics is what atyy said: Each inertial observer would call a different 3-dimensional slice of spacetime "space" (assuming that they assign coordinates to events using a pretty obvious definition of simultaneity involving light, a mirror and a clock).
 


Boy,
Don't be disallusioned that you don't understand "spacetime". In some sense, nobody does, but it EXPLAINS much of what we oberserve experimentally...so its a very useful set of rules/relationships/concepts...until a better one arrives.

Einstein published his general relativity and Minkowski subsequently formalized the idea of four dimension spactime...Einstein adopted it...And physicsts spent the next twenty years slowly discovering what general relativity really means...
 


Posting the same thing again so that the LaTeX can be seen...

We could define spacetime to be the set \mathbb R^4 and let functions of the form C:\mathbb R\rightarrow\mathbb R^4 represent an object's motion, even if we knew nothing about special relativity. It's this definition that turns time into a "dimension". Time is a dimension in that model, for the reasons DaleSpam explained.

In this model of spacetime, "space" is a subset of spacetime such that all the members of it are simultaneous (i.e. have the same time coordinate). The difference between SR and pre-relativistic physics is what atyy said: Each inertial observer would call a different 3-dimensional slice of spacetime "space" (assuming that they assign coordinates to events using a pretty obvious definition of simultaneity involving light, a mirror and a clock).
 


boysherpa said:
I have been trying to figure this one out for some time now. I have read much on the subject, but it seems to be dealt with in such a cavalier fashion. So, here goes...

We speak of space-time as if it were something packaged. I have a problem with this. Let me list the difficulties I have:

Concerning position:
1. In physical 3-space, I can position an object anywhere I like, relative to an arbitrary (0,0,0) position.
2. After any arbitrary operation, the objects position can be anywhere in 3-space, including any previous position.
3. The object may be placed in + or - position relative to the origin.
4. Any operation changing the objects position instantiates or necessitates the creation of time. Without a change of position, there is no need to speak of time.
5. Changes in position may be made with an infinity of possible velocities and accelerations, positing "time"
Concerning time:
A. I have no control over the timing of an event - it always occurs at the present - dissimilar from item 1.
B. I can never reuse the present or a previous time - dissimilar from item 2.
C. Causality forces only forward motion in time - dissimilar from item 3.
D. The flow of time does not instantiate a change of position - dissimilar from item 4.
E. Time does not seem to have various rates of flow (relativity excepted) - dissimilar from item 5.

It would seem, then, that time is only superficially similar to 3-space, in that it operates in some mathematical models in a fashion similar to the spatial distances. However, A-E behaviors are distinctly different from 1-5 behaviors.

So, how can we group time with space? It would seem time is something wholly different, and perhaps not of the same substance.

Any help?

As one comes to think of it, it is really impossible to exist without time and space - everything becomes oblivious. As you have rightly stated, time begins with the beginning of motion. The characteristic of time is two-fold:
a. Linear time
b. Oscillating time
A body moving in a linear motion will generate linear time. On the other hand, a body moving in rotatory motion will generate an oscillating time.Whatever the case is, time is a measure of space in motion while space is a measure of space at 'rest'. It would be better to think of time as having intrinsic and extrinsic qualities.
Intrinsic qualities of time play on the elements of a body as classical physics would have us believe. The Galileian coordinates of space and time with respect to an entity's own inertial frame generates its intrinsic qualities of time.When this system becomes a relativistic system, space changes at some predictable rate. This rate of change generates the extrinsic qualities of time that can either be linear or oscillating in nature.
Thus, time is a dimension of space that is changing and therefore, is a dimension.
 


So, how can we group time with space? It would seem time is something wholly different, and perhaps not of the same substance.

I think time can be logically grouped with space even if it's something wholly different. Did Minkowski set d= ict for a fourth dimension...seems ok...

Regardless of how you want to think of the relationship, we believe space/time/energy/mass all emerge simultaneously,or close to it, from a random fluctuation, or if you prefer, big bang...it appears they are intrinsicly linked "at birth" but of course nobody knows precisely why or how...maybe a theory of everything will plumb that depth...

You have a number of suppositions which you are of course entitled to, but if you depend on statements/hypothesis contrary to current science you can't expect to end up with results consistent with current science. For example:
Time does not seem to have various rates of flow (relativity excepted)

makes no sense since 1905 or so and special relativity...sure it seems that way in everyday life, but physics should take you beyond your senses...
 


This has been a great discussion! I have spent many years reading in this area, and have noted some of the discussion points above. A couple of the replies have hit home at what I think causes my confusion with time.

I am mostly curious about the need for time to explain displacements in space (or oscillations, good point), and whether this defines time or whether time exist independently. Maybe another way to put this is that we humans need time but the universe doesn't. Notice that I am purposefully avoiding details because this is a top-level issue.

Some of the posts seem to be unable to separate the mathematical modeling from "reality" - time and space has nothing to do with mathematics. Mathematics is our tool to represent these things. If we cannot explain these items without mathematics, then we do not understand them. This is the situation with quantum mechanics. We have a wonderful predictive tool with QM, but no ability to answer questions like "why" or "how".
 
  • #10


boysherpa said:
Some of the posts seem to be unable to separate the mathematical modeling from "reality" - time and space has nothing to do with mathematics. Mathematics is our tool to represent these things. If we cannot explain these items without mathematics, then we do not understand them.
That's definitely not true. You can only understand things that you have a theory for, and you need mathematics to make the theory unambiguous.
 
  • #11


boysherpa said:
If we cannot explain these items without mathematics, then we do not understand them.

Just the opposite. If you can't describe something quantitatively, you don't understand it.

boysherpa said:
This is the situation with quantum mechanics. We have a wonderful predictive tool with QM, but no ability to answer questions like "why" or "how".

QM is no better and no worse than classical mechanics in this regard. The only difference is that classical mechanics is intuitive and QM is not.
 
  • #12


Concerning Fredrick and Vandadium's posts:

Good points, from the quantitative perspective. I will concede that. I was thinking in a rather limited sense. The "how" and "why" questions are separable from the quantitative questions. Oh, and I don't think we should believe that understanding something only means quantitative modeling. Equating the universe to a mathematical model seems, at least to me, a tenuous concept (and there are excellent mathematical reasons for this position, such as self-consistency arguments).

I will take issue with this statement from Vanadium's post (forgive my quoting technique):

<boysherpa>'This is the situation with quantum mechanics. We have a wonderful predictive tool with QM, but no ability to answer questions like "why" or "how".'
<vanadium> "QM is no better and no worse than classical mechanics in this regard. The only difference is that classical mechanics is intuitive and QM is not."

Actually, the last sentence is the key here. "Every action has an equal and opposite reaction" is quite different from "I have no idea what is inside the box, but I can predict quite exactly what should happen over a large number of outcomes". It's not at all that it is intuitive. Rather, there are two important differences. First is that reductionism still applies in classical mechanics, and the underlying mechanisms are accessible to the observer. Second, classical mechanics is to a high degree deterministic in nature. Of course, we could argue til the cows come home that these qualities are merely approximations...
 
  • #13


boysherpa said:
Some of the posts seem to be unable to separate the mathematical modeling from "reality" - time and space has nothing to do with mathematics.
This is a very common claim, but it is simply wrong. Math is the language of logic; if the universe behaves logically then it can be described mathematically. It is as simple as that.

IMO, a non-mathematical treatment of physics is like reading an English translation of Tolstoy. You can get the plot and understand the story, but you miss all of the subtle things that make him great. As divorced from "reality" as our mathematical models are, our verbal descriptions and plain-language models are far worse.
 
  • #14


Classically, you can ask what the value of an unmeasured (and unmeasurable) quantity is. Quantum mechanically, you cannot. What makes one of these "better" than the other? I maintain it's personal preference - maybe based on comfort, maybe on philosophy, maybe on something else. But just that - preference.
 
  • #15


boysherpa said:
Some of the posts seem to be unable to separate the mathematical modeling from "reality" - time and space has nothing to do with mathematics. Mathematics is our tool to represent these things. If we cannot explain these items without mathematics, then we do not understand them.

Yes, the answer I gave was only for a particular model of reality. Maybe someday a more powerful theory than general relativity will be found, and we will get yet another notion of "space" and "time". At the same time, mathematics is just an extension of everyday language - after all the number 7 is already a mathematical concept. Many mathematicians and physicists do look for the simplest ways to think about things correctly.

Thurston, http://arxiv.org/abs/math/9404236
 
  • #16


boysherpa said:
The "how" and "why" questions are separable from the quantitative questions.
Not really. Scientific answers are always in the form of a theory that agrees with experiment, regardless of whether the question is "how" or "how much". A theory can't even be stated unambiguously without mathematics.

boysherpa said:
Equating the universe to a mathematical model seems, at least to me, a tenuous concept (and there are excellent mathematical reasons for this position, such as self-consistency arguments).
There may be good reasons why we shouldn't believe that the universe is a particular mathematical model, but we're not arguing that it is. At least I'm not.
 
  • #17


boysherpa, observe that you are using inaccurate mathematical models in your own statements about the universe. You speak of "3-space" but that is a simplified mathematical model that does not correspond to reality: look at the precession of the perihelion of Mercury. Within a cube-shaped boundary around the Sun at 2 million km per side, in flat space there would be 2³ × million³ = 8 × 1027 km³ of "three dimensional space" but experimental observation shows there's more than that.

There isn't any real "3-space". Reality is some funky thing where time is integrally connected to length, width, and depth and gets correspondingly distorted when they get distorted. Thinking that there's a "3-space" in reality is a projection of your local perceived environment upon the rest of the universe, the way that people used to think that the Sun revolves around the Earth.
 
  • #18


Hi everyone.

I am new to this forum, but not new to science forms. I would like to participate in this discussion on time, but before I do I want to make sure that everyone’s definition of time as it is being used here is agreed upon by all participants. I have run into many snags on this topic because of all the people in a discussion on time have their own definition on what time is. What it always comes down to is that there are those people who say time is just a consideration of man, and there are those that say time is a real physical something.

I am one of those people that say time is actually a consideration based on our perception of the movement of objects. Time does not move or cause things to move. It is this perception of motion which gives us the idea of time. There may be some of you that disagree with this. This is fine, I would really like to hear your argument against this idea of time.

I have browsed this science forum and found that the people that participate in this forum are sticklers for facts that are backed up by scientific evidence, this is a good thing, the way all science forums should run.

So I just want to make sure that everyone is on the same page on this subject of time, or at least announce a definitive statement of your personal idea of time, that way there is no misunderstandings.


If there is anyone who thinks that time is a real thing whether it be a solid, liquid, gas, or some form of energy, I would really like to hear your explanation of this that has some scientific observational evidence.


Thanks.
 
  • #19


IMO, time is simply the "t" in the "d/dt" terms from all the physics equations. As far as observational evidence goes, every clock is based on some physical mechanism that has a "d/dt" term in it somewhere, so there is probably evidence on your wrist.
 
  • #20


boysherpa said:
This has been a great discussion! I have spent many years reading in this area, and have noted some of the discussion points above. A couple of the replies have hit home at what I think causes my confusion with time.

I am mostly curious about the need for time to explain displacements in space (or oscillations, good point), and whether this defines time or whether time exist independently. Maybe another way to put this is that we humans need time but the universe doesn't. Notice that I am purposefully avoiding details because this is a top-level issue.

Some of the posts seem to be unable to separate the mathematical modeling from "reality" - time and space has nothing to do with mathematics. Mathematics is our tool to represent these things. If we cannot explain these items without mathematics, then we do not understand them. This is the situation with quantum mechanics. We have a wonderful predictive tool with QM, but no ability to answer questions like "why" or "how".

You are correct. An entity without consciousness is devoid of the ability to discern change. Human beings require time as an instrument to understand and communicate the concept of change. Aging is a process of change. So too is displacement. We cannot say that the universe does not need time, as we do not yet know whether other elements of the universe, apart from humans, are also conscious. A conscious entity is aware, and through awareness, has the capacity to discern changes.
We have yet to device experiments or even prove that entities apart from humans are conscious or not. Perhaps our being alive is the culmination of millions of processes that are perpetually changing according to the laws of our inertial frame - the Earth - perhaps gravity.
 
  • #21


Regarding the definition of time...

We can define a coordinate system in Newtonian mechanics, SR and GR as a function x:M\rightarrow\mathbb R^4, where M is spacetime, and then define "coordinate time" as a component of that function. In SR and GR it's also necessary to define "proper time", which is the integral of \sqrt{-g_{\mu\nu}dx^\mu dx^\nu} along a curve.

That takes care of the definitions in the mathematical models used in these three theories, but the theories must still include postulates that tell us how these things are related to what clock's measure. In Newtonian mechanics, clocks measure coordinate time. In SR and GR, a clock measures the proper time of the curve that represents its motion.
 
  • #22


Makep said:
You are correct. An entity without consciousness is devoid of the ability to discern change.
No, this is incorrect. Even simple single-cell organisms will react to changes in their environment by swimming towards new food sources or away from toxins. This is called chemotaxis, and it is very common.
 
  • #23


DaleSpam said:
No, this is incorrect. Even simple single-cell organisms will react to changes in their environment by swimming towards new food sources or away from toxins. This is called chemotaxis, and it is very common.

I disagree. Chemotaxis is the process where living entities respond to chemical stimuli, not such things as changes in inertial frames and hence time and space, in relativistic sense. There is another concept in which this can be aptly placed - the concept of trophism, as in phototrophism, geotrophism, hydrotrophism, etc.
But this trophic changes are demonstrable in all living things on earth. By some unexplainable phenomena, lower and simple animals can respond to physical changes. Do the chemicals in them 'sense' the need to change or are they compelled to change for which the observable behavior are the result and proof? I wonder.
 
  • #24


Your post is confusing. First you disagree with what I said:
Makep said:
I disagree.
And then you agree with what I said:
Makep said:
By some unexplainable phenomena, lower and simple animals can respond to physical changes.
 
  • #25


DaleSpam said:
Your post is confusing. First you disagree with what I said:And then you agree with what I said:

To be exact, I do not agree with the usage of the word
chemotaxis
. It is reserved for chemical responses by basic life forms. Not to changes in space and time.
 
  • #26


Huh? How can you have a concentration gradient (dC/dx) without space (x), and how can a cell move (dr/dt) along it without time (t)?

This whole discussion about consciousness is off topic. If you wish to continue it then you should start a new thread.
 
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  • #27


DaleSpam said:
Huh? How can you have a concentration gradient (dC/dx) without space (x), and how can a cell move (dr/dt) along it without time (t)?

This whole discussion about consciousness is off topic. If you wish to continue it then you should start a new thread.

Good point. Don't you think space can also be concentrated such that there is a gradient for matter to move along? If not, then why not? If it is possible then how? Is there any mechanism available to allow matter to become aware of such changes?
 
  • #28


Makep, your comments make it look as though you're simply saying anything that comes to mind to try to get people to respond to you, which other people will probably perceive as trolling. People will get annoyed and frustrated with you if you keep doing that sort of thing.
 
  • #29


DaleSpam said:
IMO, time is simply the "t" in the "d/dt" terms from all the physics equations.

Yes in physics equations the concept of time is symbolized with the letter t. So let me ask you, in all physics equations, does this symbol "t" represent a real physical thing or a concept?

As far as observational evidence goes, every clock is based on some physical mechanism that has a "d/dt" term in it somewhere, so there is probably evidence on your wrist.

Since this is a science forum I am going to take what you said literally and not assume a thing. This will point out how what you stated as observational evidence of time is faulty.

Yes we can observe a clock or wristwatch. What is being observed is a physical thing called a clock or a wristwatch. No observation of a thing called time.

I have owned many clocks and wristwatches. I have disassembled some clocks and wristwatches and have never observed a physical thing you describe as a "d/dt term" somewhere in these time pieces. I know that what I just said may seem a bit silly, but you said that a clock has a "d/dt" term in it somewhere.

Do you see how what you said is not a description of any observation of a physical thing called time, you just talked about equations.

So I will have to ask you again, what does the symbol "t" in physics equations represent?

Is it a representation of a physical universe thing or phenomenon, or is it representing a concept?



Clocks are a man made device operating as man designed it, counting off man made increments that man gave a numeric significance to that results in a man made concept called time. Clocks are designed to give numbers, to which man assigns a significance or importance to. A clock could be considered to be a device or machine that generates a number or numbers in a regulated manner that was pre-determined by man. A clock is akin to a regulated number generator that converts mechanical, electrical, or the motion of an object to a number through pre-determined engineering of the device, and these numbers are delivered at a rate that follows the set standards that man has agreed to be universal in all such machines.

If you think that clocks actually measure a physical thing called time please share with me your definition of a clock and time that shows that clocks actually measure anything outside of its immediate construction. What outside influence would a clock be measuring?
 
  • #30


Fredrik said:
Regarding the definition of time...

We can define a coordinate system in Newtonian mechanics, SR and GR as a function x:M\rightarrow\mathbb R^4, where M is spacetime, and then define "coordinate time" as a component of that function. In SR and GR it's also necessary to define "proper time", which is the integral of \sqrt{-g_{\mu\nu}dx^\mu dx^\nu} along a curve.

That takes care of the definitions in the mathematical models used in these three theories, but the theories must still include postulates that tell us how these things are related to what clock's measure. In Newtonian mechanics, clocks measure coordinate time. In SR and GR, a clock measures the proper time of the curve that represents its motion.

What do you think time is? You gave examples of time used in math, but do you think time is more than an equation.
 
  • #31


In economics you have lots of arbitrary dimensions that are really just categorizations - like 10 different economic sectors (finance, industrials, energy etc.) which could be used in regressions. So I get that, but in spacetime you have the concept of orthogonality between these dimensions correct? This does not really apply to the category-dimensions that I am more familiar with. How does orthogonality work with 4 dimensions and how is time orthogonal to the three space dimensions and does it make sense to think of y being orthoganal to x,z &t ?
 
  • #32


john 8 said:
What do you think time is? You gave examples of time used in math, but do you think time is more than an equation.
Time is certainly more than that mathematical expression, but any answer to the question of what time "is", will always be in the form of a mathematical model and a set of instructions about how to use that model to make predictions about the real world. The best answer we have so far is the one provided by general relativity. The relevant "instruction about how to use the model to make predictions" says that what a clock measures is the proper time of the curve that represents the clock's motion. I don't think anyone has a better answer than that at this time.

Note that two definitions of time are needed. First we have to define time in a mathematical model (in this case as a certain integral), and then we have to define it operationally (as "what a clock measures"). Then we postulate how the two are related.
 
  • #33


BWV said:
So I get that, but in spacetime you have the concept of orthogonality between these dimensions correct?
...
How does orthogonality work with 4 dimensions and how is time orthogonal to the three space dimensions and does it make sense to think of y being orthoganal to x,z &t ?
You should think of the spacetime manifold as the set of all events, and a coordinate system as a function that takes a point in spacetime to an ordered 4-tuple (t,x,y,z) of real numbers. The direction in which t is increasing is not necessarily orthogonal to the direction in which x is increasing for example.

That being said, in special relativity there's a class of coordinate systems that are "special" in a certain sense. They are called "global inertial frames" or just "inertial frames". If we use an inertial frame, then the t direction is orthogonal to the x direction in the sense that if u and v are two vectors in the t and x directions respectively, we have g(u,v)=0, where g is the metric.

So what does that have to do with orthogonality? Consider the definition of a "scalar product" (a.k.a. "inner product"). It's a function (x,y)\mapsto\langle x,y\rangle that takes two vectors to a number and satisfies the conditions (i) <x,y>=<y,x>, (ii) <ax+by,z>=a<x,z>+b<y,z> and <x,ay+bz>=a<x,y>+b<x,z>, (iii) <x,x>\geq0 and <x,x>=0 only when x=0. The Cauchy-Schwarz inequality tells us that

\frac{|\langle x,y\rangle|}{\|x\|\|y\|}\leq 1

and that means that we can define an angle between any two vectors in an inner product space by

\cos\theta=\frac{\langle x,y\rangle}{\|x\|\|y\|}

That angle is zero when <x,y>=0. Now, a metric isn't exactly the same as a scalar product, because it doesn't satisfy condition (iii) above. (g(u,u) can be negative, and it can be zero for non-zero u). That means that it doesn't satisfy the Cauchy-Schwarz inequality, and that the "angle between vectors" isn't well-defined. But if we want to, I suppose we can ignore that and say that u and v are "orthogonal" if g(u,v)=0. If we choose to do that, then the t and x directions (defined by an inertial frame) are orthogonal.
 
  • #34


john 8 said:
Yes in physics equations the concept of time is symbolized with the letter t. So let me ask you, in all physics equations, does this symbol "t" represent a real physical thing or a concept?
Obviously a real physical thing. How can you get more physical than a physical variable measured by a physical device that operates according to a physical principle?
john 8 said:
I have disassembled some clocks and wristwatches and have never observed a physical thing you describe as a "d/dt term" somewhere in these time pieces.
Then you didn't understand what you were looking at.
 
  • #35


That's true that we should rely on maths to have a quantitative explanation of everything we want to be 'logic'. But I think that mathematic equations, formula and theories are just good for the train of the 'daily life' , to manage things and predict the phenomena. Our brain , our memory is something much more sophisticated than some formula and it escapes the 'limits' of mathematic language which is just a tool . Do animals have the same conception of time ? Does time have any meaning to them? So I deduce that our brain is designed on such an unknown basis which enable us to 'perceive' and 'measure' time. Another example, it is about the conceptual ability of some primitive tribes around the world about the 'time' : for them the concept of 'tomorrow' doesn 't exist AT ALL , they don't see the 'future' , they just live in some 'momentum' , they can't anticipate the things which could happen in the 'future'. At this moment i write this and i experience it like all the other billion alive people around the world , 'yesterday' along with million million years ago are the same ,e.g. an 'illusion'. What in the world can prove that we don't 'live' in a sort of 'Closed Matrix' where time and space are static , and all we perceive as motion and movement are nothing but a static time? When we dream , we are motionless ourselves, but we 'see' the scenery in motion and we are unable to determine the time flown , we can dream just in few minutes some scenery and events as if they took some years, and vis-versa , we can dream a dream within 24 hours and having the impression that it last just few minutes. How can we quantify such a mysterious phenomenum which is the Time?
 
  • #36


Just like cutting up a clock ever finer and still never finding the t in the thing.
We can cut up a human to atoms and never find a bit of conscience.
But, being a conscience creature immersed in four dimensions, I can say I have some kind of awareness of time. Is it part of the equations? Does Science math have a problem if it includes the concept of awareness into the time concepts.
 
  • #37


Meteor9, all of your statements are either obviously irrelevant (to those of use who understands what science is) or obviously false. (Do you really think that there are primitive tribes where no one who looks at a pregnant woman is capable of thinking that she's going to have a child in the future?) How we feel about time is completely irrelevant. Science is about finding theories and testing them, and there are some theories about time that have passed some amazing tests. The best one is general relativity.
 
  • #38


Alfi said:
But, being a conscience creature immersed in four dimensions, I can say I have some kind of awareness of time. Is it part of the equations? Does Science math have a problem if it includes the concept of awareness into the time concepts.
It wouldn't be a problem if you could find a theory that defines that concept and uses it to predict the results of experiments as well as GR or better. But there's no such theory today and it's very likely that there never will be.
 
  • #39


OK Fredrik , all my statements are 'irrelevant' and 'false' in 'your' sight , i just expressed my opinion about time because John asked everyone to say what they 'think' about that. I never imprison my mind and my point of view in the 'jail' of theories and formula , i just try going beyond the conventional scales . To answer your question about the pregnant women in primitive tribes or their vision about the seasons ,day and night , etc , i should say NO , they don't realize that something would happen in the 'future' , and don't perceive a concept we call 'time'. For example if any of them find him/herself in a critical situation , they just die , because they don't see the 'tomorrow' and can't visualise a change in that situation in the 'future'. On the other hand , for example when we travel in some different countries or regions with different culture or tradition , 'apparently' we have moved in the space , i mean we find ourselves in a different location , but in reality we just did a travel in some other time. We notice that in the new 'space' , time flows totally differently from the one we lived in previously. There we should adapt ourselves with the new 'time' and not the new 'space' (location). Even in a given 'advanced' country , rural area and regions have a different 'time' than the one of the big industrialised and modern cities . So Time is a 'versatile' and 'polymorph' entity .
 
  • #40


Alfi said:
Just like cutting up a clock ever finer and still never finding the t in the thing.
We can cut up a human to atoms and never find a bit of conscience.
But, being a conscience creature immersed in four dimensions, I can say I have some kind of awareness of time. Is it part of the equations? Does Science math have a problem if it includes the concept of awareness into the time concepts.

Try:

Block time: Why many physicists still don't accept it? by Hrvoje Nikolic
http://fqxi.org/community/forum/topic/259

"Forget time" by Carlo Rovelli
http://fqxi.org/community/forum/topic/237

Essentially, the notion of time we use when talking about music and memory is a different from the notion of time in our current theories of nature. They are presumably related, but not very directly. You can also look up the "binding problem" in neurobiology, but I am not aware of any generally accepted solution to the question.
 
  • #41


meteor9 said:
To answer your question about the pregnant women in primitive tribes or their vision about the seasons ,day and night , etc , i should say NO , they don't realize that something would happen in the 'future' , and don't perceive a concept we call 'time'. For example if any of them find him/herself in a critical situation , they just die , because they don't see the 'tomorrow' and can't visualise a change in that situation in the 'future'.

That's interesting. Any references you recommend for reading about this?
 
  • #42


atyy , as a reference for that , you can search on 'arte channel' , anthropology documentary about massaii and pigmy tribes in africa, or just use google search.
 
  • #43


meteor9 said:
OK Fredrik , all my statements are 'irrelevant' and 'false' in 'your' sight , i just expressed my opinion about time because John asked everyone to say what they 'think' about that.
It's fine to express opinions, but don't forget that this is a science forum. Your statements were irrelevant. E.g. the fact that we might feel that more (or less) time has passed in a dream is completely irrelevant to science.

meteor9 said:
I never imprison my mind and my point of view in the 'jail' of theories and formula , i just try going beyond the conventional scales .
I don't think you realize what you're saying. Science is about finding theories that do a good job predicting the results of experiments. There's no other way to obtain knowledge about how the universe behaves. So if you can go beyond the "jail" of theories, you can go beyond science and know things that are unknowable.

meteor9 said:
...they don't realize that something would happen in the 'future' , and don't perceive a concept we call 'time'...
I don't see how you (or anyone) can believe that this is true, and even if it is, it has nothing to do with science.
 
  • #44


This thread is getting off-topic again. If y'all want to have a conversation about consciousness and the perception of time or on social aspects of time please start a new thread in the philosophy or social sciences forum. It doesn't belong here.
 
  • #45


Fredrik said:
Time is certainly more than that mathematical expression, but any answer to the question of what time "is", will always be in the form of a mathematical model and a set of instructions about how to use that model to make predictions about the real world. The best answer we have so far is the one provided by general relativity. The relevant "instruction about how to use the model to make predictions" says that what a clock measures is the proper time of the curve that represents the clock's motion. I don't think anyone has a better answer than that at this time.

Note that two definitions of time are needed. First we have to define time in a mathematical model (in this case as a certain integral), and then we have to define it operationally (as "what a clock measures"). Then we postulate how the two are related.


Thank you for your answer. I noticed that you say time is more than a mathmatical expression and then go on to describe how time is a mathmatical expression.

So I guess what I want to know from you is, what is your understanding of time? Do you think that time is a thing that exists in the physical universe as some form of matter or energy, or do you think that it is something else?

I say that the concept of time is just that, a concept of man and nothing more.
 
  • #46


DaleSpam said:
Obviously a real physical thing. How can you get more physical than a physical variable measured by a physical device that operates according to a physical principle?

OK DaleSpam. You say time is a physical thing. I am interested to hear more about this idea that you have that time is physical. I have yet to see any physical evidence or scientific reference that provides evidence of this time thing being physical. If you want to say that time is physical then can you at least tell me in what way time is physical?

Is it a solid?
Is it a gas?
Is it some form of energy?

What exactly do you mean when you say time is a real physical thing? Can you provide more information on this?


Lets now look at what you said was observational evidence of time in post #19.

DaleSpam said:
IMO, time is simply the "t" in the "d/dt" terms from all the physics equations. As far as observational evidence goes, every clock is based on some physical mechanism that has a "d/dt" term in it somewhere, so there is probably evidence on your wrist.

Here was my response to your evidence.

"I have owned many clocks and wristwatches. I have disassembled some clocks and wristwatches and have never observed a physical thing you describe as a "d/dt term" somewhere in these time pieces. I know that what I just said may seem a bit silly, but you said that a clock has a "d/dt" term in it somewhere.

Do you see how what you said is not a description of any observation of a physical thing called time, you just talked about equations."



And here is your response to that.



DaleSpam said:
Then you didn't understand what you were looking at.

Now it seems that you have missed my point.

You said:
"every clock is based on some physical mechanism that has a "d/dt" term in it somewhere, so there is probably evidence on your wrist."

Now remember you said that this was observational evidence.

I will tell you right now with 100% certainty that if you look (observe) at or in any clock or wristwatch all you will see is physical matter in one form or another. All clocks and such are made from physical matter, there is no physical mathematical term that exists in a clock or wristwatch. So by saying that some physical mechanism has a "d/dt" term in it somewhere is observational evidence of time is wrong. A physical mechanism will be made of electrons, protons and neutrons, physical mechanisms are not made of symbols.

Observational evidence means that it can be seen by our eyes. By looking somewhere in a clock you will not see "d/dt". This may sound obvious, but when I said that I did not see this thing "d/dt" when I disassembled a clock, you told me that I did not understand what I was looking at.

Really? I did not understand. When I look at a clock disassembled, or not, all I or anyone will see is physical matter that has the ability to reflect light so that we can perceive it.

So you see, if something is going to be used as observational evidence than it will have to be observed by our eyes. The term "d/dt" is not a physical thing, so it does not reflect light, and it is not a thing that exists in or on clocks that is observable.

If you want to give observational evidence of time than just make sure that this evidence can actually be observed.

Thank you.
 
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  • #47


john 8 said:
I noticed that you say time is more than a mathmatical expression and then go on to describe how time is a mathmatical expression.
That's not what I said. Please read my answer again.

john 8 said:
So I guess what I want to know from you is, what is your understanding of time? Do you think that time is a thing that exists in the physical universe as some form of matter or energy, or do you think that it is something else?
I don't have anything to add to the answer provided by general relativity. To do that, I'd have to come up with a better theory myself first, and that isn't easy to do.

It's however very clear that time isn't a form of matter.

john 8 said:
I say that the concept of time is just that, a concept of man and nothing more.
No, the word time is a concept of man, just like the word "hammer", but if you hit yourself on the thumb with a hammer it still hurts.

I would also like to remind you that this is a science forum. The things you say don't seem to have anything to do with science. If you feel that they do, you should try to make the connection more clear.
 
  • #48


john 8 said:
OK DaleSpam. You say time is a physical thing. I am interested to hear more about this idea that you have that time is physical. I have yet to see any physical evidence or scientific reference that provides evidence of this time thing being physical. If you want to say that time is physical then can you at least tell me in what way time is physical?
"Physical" means "of or relating to physics". Time is an integral part of every mainstream physical theory -
Newton's laws: f = dp/dt
Thermodynamics: dS/dt >= 0
Maxwell's laws: del x E = -dB/dt
Relativity: ds² = -dt² + dx² + dy² + dz²
etc.

These physics theories, which all include time, have been experimentally verified with more than a century of accumulated physical evidence each. If centuries of peer-reviewed experimental evidence are insufficient then consider the additional fact that each of these theories have been used to develop a wealth of material devices which all work in the manner predicted by the physical theory.

Given all of this, consistent physical theories using time, centuries of data verifying those theories, practical devices functioning according to the theories, how can you not understand that time is physical? I suspect that you do understand but are simply trolling.

If you are not trolling and actually hypothesize that time is not physical then please post (on the independent research forum) your alternate scientific theory that does not use time to make its physics predictions.
 
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  • #49


Fredrik said:
That's not what I said. Please read my answer again..

I read your post again. You talk of time in terms of math.



Here is what you said:


Fredrik said:
Time is certainly more than that mathematical expression, but any answer to the question of what time "is", will always be in the form of a mathematical model and a set of instructions about how to use that model to make predictions about the real world. The best answer we have so far is the one provided by general relativity. The relevant "instruction about how to use the model to make predictions" says that what a clock measures is the proper time of the curve that represents the clock's motion. I don't think anyone has a better answer than that at this time...

Fredrik said:
Note that two definitions of time are needed. First we have to define time in a mathematical model (in this case as a certain integral), and then we have to define it operationally (as "what a clock measures"). Then we postulate how the two are related. ...

What you said here does not definitively state if you think time is a physical thing or not. This is important to know since we are discussing time at this moment. You just need to define your terms so that what you are saying is not vague or ambiguous, like you said this is a science forum and you are participating in this discussion, I will assume that you have some scientific understanding of what time is.


Fredrik said:
I don't have anything to add to the answer provided by general relativity. To do that, I'd have to come up with a better theory myself first, and that isn't easy to do...

Science is about looking about the world around you and trying to figure out what it is and how it works through already established facts.

I asked you what you thought time was. I am sure that you can make your own observations and conclusions without depending on some authority on the subject. We all know what Einstein has to say about time. So I ask you, after getting an understanding of what Einstein said about time and by your personal experience of the world around you, what conclusions have you come up with?

From everything that you have read and experienced in regards to time, what is your understanding of time? Is time a real physical thing or not? That’s all, simple as that.

Fredrik said:
It's however very clear that time isn't a form of matter...

Alright, so what do you think time is?


Fredrik said:
No, the word time is a concept of man, just like the word "hammer", but if you hit yourself on the thumb with a hammer it still hurts..

Yes the word hammer describes a real physical thing, a hammer by any other name is still a hammer.

The word hammer is a man made word used to describe a real thing. There is no doubt or argument that the word hammer describes a physical object. There is no doubt or argument that the object described by the word hammer is a real physical thing.

So the word time is a man made word used to describe WHAT?

Does the word time describe a physical thing? If so please elaborate.

I am sure you must have some clear understanding of what time is, so just simply say what that understanding is. Time is either a physical thing or not.


Fredrik said:
I would also like to remind you that this is a science forum. The things you say don't seem to have anything to do with science. If you feel that they do, you should try to make the connection more clear.

Yes I know this is a science forum. Time is one of the basic foundations on which the science of physics is based on. It is completely relevant to ask questions about time in order to gain a better understanding of time. My questions are direct and concise.

Do you think time is a physical thing or not.

I have come to the understanding that time is not a physical thing and is just the concept of man. I have read other people say that time is not a concept, yet they will not say what it is. So that is why I am asking you about time, you seem to think that time is more than just a concept, so fill me in, what do you know?

What evidence am I lacking that definitively proves that time is more than a concept?

Just show the observational science, please.

Thank You.
 
  • #50


DaleSpam said:
"Physical" means "of or relating to physics". Time is an integral part of every mainstream physical theory -
Newton's laws: f = dp/dt
Thermodynamics: dS/dt >= 0
Maxwell's laws: del x E = -dB/dt
Relativity: ds² = -dt² + dx² + dy² + dz²
etc..

Yes time is part of physics. That is obvious. I am not asking if time is part of physics. I am asking if time is physical per the definition of physical that state:

Physical.
of or pertaining to that which is material: the physical universe.

Pertaining to the properties of matter and energy other than those peculiar to living matter.


DaleSpam said:
"These physics theories, which all include time, have been experimentally verified with more than a century of accumulated physical evidence each. If centuries of peer-reviewed experimental evidence are insufficient then consider the additional fact that each of these theories have been used to develop a wealth of material devices which all work in the manner predicted by the physical theory.

Given all of this, consistent physical theories using time, centuries of data verifying those theories, practical devices functioning according to the theories, how can you not understand that time is physical? I suspect that you do understand but are simply trolling.

If you are not trolling and actually hypothesize that time is not physical then please post (on the independent research forum) your alternate scientific theory that does not use time to make its physics predictions.

Right, rocks are a physical thing and physics can described exactly with precise definitions and observational evidence what the nature of rocks are. Physics puts the rock and all other things that are made in similar ways to the rock in the category of matter.

Heat is a physical thing that can be described and defined so as to give a clear understanding of what heat is. Physics describes heat and all those things with similar attributes in the category of energy.

Physics is a branch if science that is concerned with the laws that govern the structure of the universe, and the investigation of the properties of matter and energy and their interactions.

When I ask you if you think time is physical and you tell me that it is physical because it is part of physics, well I will have to ask you to be very specific and tell me what category of physics time is a part of. Since you pointed out that time is part of physics, and physics deals with matter and energy, which category do you think time belongs in?

I have stated that I have come to the understanding that time is just a concept based on what I have observed in the world around me and by the complete lack of any physical evidence that disproves my understanding.

So this brings me to the point of why I am asking you what your understanding of time is. I might be wrong, and so you can correct me.

This is not trolling, it is going on a science forum and discussing an aspect of physics with those people who are interested and have some understanding of physics and time.

This is the place to discuss science topics and learn more about these topics.

Asking you to explain in what way you think time is physical is a legitimate question and should be very easy to answer. Just because I may disagree with you on the nature of time is in no way a sign that I am trolling. I have stated my view on time based on observation and lack of evidence to prove that I am mistaken. I have asked you to just explain how you think time is a physical thing, which is a normal type of question that is required when someone may have a disagreement with what the other person said.

So, to sum this up, please provide a more detailed explanation of what you mean by the statement that time is a physical thing.

Thank You.
 
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