Is Time a Dimension? Exploring the Differences

[Sjorris]

John, the 'physical' you are talking of is not the same as all others in this thread are talking about.

You are using a definition of 'physical' which is synonymous with 'material' (in it's broadest sense, so including photons, muons, waves and whatnot), everyone else is using it meaning 'part of a physical theory'.

A mathematical description of time doesn't make it less true. One could easily restate the mathematical formulations in words (sadly, language is far less suitable for describing physical theories than math) and it wouldn't lose or gain any extra credibility.
Time is a concept which is used in a lot* of physical theories, therefore being physical.
Special relativity, for example, makes it very obvious that you can't describe the universe without the concept of time, therefore time has to be part of the universe, so any physical theory describing the universe has to include the concept of time, which makes time a physical concept.

I've been trying to come up with a more clear defintion of what time is, but it's hard without using some kind of self-reference like 'change', distance on the 'time axis', and these are just for the non-relativistic concept of time.

* Simplified physical theories for stationary situations do not need the concept of time, but these are just special cases (d/dt=0) of more general physical theories.

 

[john 8]

Originally Posted by john 8
Now correct me if I am wrong, if something is considered to be physical then it is either made of particles or waves, right? So with that in mind, where does time fit in?

Now let me ask you, where do you suppose some people get the idea that time is an actual physical thing?

Only crazy people think that time is a physical thing according to your definition of "a physical thing". (Note that we didn't know what your definition was when this discussion started).

This is a poor excuse for not answering a question. My definition of physical is the definition of physical as it is found in a standard dictionary for the English language and for physics. I am not using some secret or mysterious definition of physical.

So tell me what you think my definition of physical is and we will see if you are right about this crazy people thing. Besides it is your responsibility to clear up any misunderstood words in what you are reading. When I use a word I assume that anyone who reads that term will define that term as per the standard definition of that term. If I ever uses an archaic, or special definition of a term I always make it clear how I am using that term.

Stop avoiding answering the question. You say time is physical, so grab your dictionary, Get the correct definition, and tell me how you think time is physical. Maybe you had a misunderstanding of what physical means, if this is the case then I can see how this whole discussion with you on time has dragged on so long.

Let me know if you had a different understanding of physical, then we can clear that up and start this discussion anew. If, however, you did have the correct understanding of physical, then please explain to me how you think time is physical. Remember that all things that are classified as physical in this universe are composed of either particles or waves.

I would like to hear from you on what you think after you get this all straightened out.

There are however other reasonable ways to define what "physical" means. For example, you could define it so that anything measurable is considered physical. Another option is to define it so that any concept that's defined by a theory and (according to that same theory) affects the probabilities of the possible results of some experiment is considered physical.

Look, you accuse me of using my definition for the term physical and say that it is the reason for the confusion. Now you are giving your other reasonable ways to define physical. You are doing what you accused me of doing. Fine, at least I can see that according to your understanding of physical. Sounds like you are making a definition of physical to fit your understanding of time.

The hard cold truth is, if anything in this universe is classified as physical it will be composed of a particle or wave. That is it. There is no argument. There is no other option. There is just no way around it, although I have to give you and the others credit for trying to find another way around this stark unwavering fact. All the hem and haw and just plane wiggling around trying to prove your point that time is physical without actually saying how it is physical, is quite interesting to watch.

You do realize that if time were a physical thing then the whole internet would be filled with proof, definitions, references, observations and such, that you would have such overwhelming evidence that my viewpoint on time would be crushed out of existence.

Yet here I stand, still able to bring up legitimate reasonable doubt that time is a physical thing. I am using the fundamental knowledge of physics to raise the question of whether time is physical or not. Physics states that all things considered physical in this universe are either a particle or a wave. Now I just apply that fact to the idea of time being physical and see that according to physics time is not a physical thing. Period.

You may think that I am crazy for not going along with the belief that time is physical, but I deal only in science when it comes to gathering information and understanding of the world around me. Not faith, or information based on what some authority said, or believing some thing because everyone else believes it.

Just the facts man.

The whole subject of a science, as far as anyone is concerned, is as good or bad in direct ratio to their knowledge of it. It is up to a person to find out how precise the tools are.
A person should, before he starts to discuss, criticize or attempt to improve on the data presented to him, find out for himself whether or not the mechanics of the science are as stated and whether or not it does what has been proposed for it.

One should make up his mind about each thing that is taught in the school, or book, the
procedure, techniques and theory. He should ask himself these questions: Does this piece of data apply to the real world and can it be applied? Does it work? Will it produce results?

There are two ways man ordinarily accepts things, neither of them very good. One is to accept a statement because an authority says it is true and must be accepted, and the other is by preponderance of agreement amongst other people, as in the mindset of “I believe it to be true because so many other people believe it to be true.” There is a third way man accepts things and that is by first hand experience of things, this can be done by testing or applying data to the real world to see for yourself or just perceiving things in the real world.






Originally Posted by john 8 
How is it that you can simply and concisely state what time is and yet others who have a good knowledge of physics can not seem to grasp the simplicity of the true nature of time?

Who says that the true nature of time is simple?

It is simple. Time is either a physical thing or it is not. If time is physical then it it composed of a particle or a wave. If it does not fit this criteria, then it is not physical. Simple as that, stop making it so complicated.

People who know physics can tell you how time is defined in the current theories

Alright, so what is the literal definition(s) that these people who know physics use to define time. I know physics, and I have access to many physics books and physics dictionaries. I can tell you how time is defined in current theories, and I can tell you that there is no mention of time being a physical thing.

Where are you getting this false data? You need to think hard at how you came to the conclusion that time is physical. Is it just a belief?

Look, I have been very patient with you and the others on this topic. Just imagine if I continued to assert that some physical phenomena or thing existed despite the fact that it goes against all known physics and all physics references and definitions. You say that time is physical, yet the whole field of physics does not, has not, ever described time as a physical thing. Do you see how absurd this argument is? You continue to ignore the fact that physics has not established time as a physical thing. You my friend are arguing against what has been established in physics and all observational data regarding time.


This discussion has gone on for quite some time. It is now time for you to explain your understanding of how time is physical.

I can only hope that you reveal your understanding and maybe enlighten all of us, and not fall back on that ever so popular form of argument where you just belittle the person that you are having a disagreement with. Let's see what you do.

 

[Sjorris]

This is a poor excuse for not answering a question. My definition of physical is the definition of physical as it is found in a standard dictionary for the English language and for physics.

Stop avoiding answering the question. You say time is physical, so grab your dictionary, Get the correct definition, and tell me how you think time is physical.

http://dictionary.reference.com/browse/physical

Option 4.

 

[john 8]

John, the 'physical' you are talking of is not the same as all others in this thread are talking about.

You are using a definition of 'physical' which is synonymous with 'material' (in it's broadest sense, so including photons, muons, waves and whatnot), everyone else is using it meaning 'part of a physical theory'.

A mathematical description of time doesn't make it less true. One could easily restate the mathematical formulations in words (sadly, language is far less suitable for describing physical theories than math) and it wouldn't lose or gain any extra credibility.
Time is a concept which is used in a lot* of physical theories, therefore being physical.
Special relativity, for example, makes it very obvious that you can't describe the universe without the concept of time, therefore time has to be part of the universe, so any physical theory describing the universe has to include the concept of time, which makes time a physical concept..

This may sound like I am being picky, but what do you mean by physical concept? Are you saying that time is just a concept, or a concept that has to do with a real physical thing, (physical being those things that are composed of particles or waves.)?

I've been trying to come up with a more clear definition of what time is, but it's hard without using some kind of self-reference like 'change', distance on the 'time axis', and these are just for the non-relativistic concept of time...

You are not required to come up with “more clear” definitions of anything. The whole of human communication is based on and can only function as a smooth applicable tool if there is an agreement as to how everything is going to be defined. The way it works is that we assign a responsibility to a few people to gather a consensus on what terms are to mean or describe, and from those definitions we are all on the same page so to say when it comes to communicating ideas. For you to try and make a more clear definition of time is to by-pass this whole system of how terms are defined and in doing so you will throw an arbitrary into the understanding of time as it is universally understood at this time.
You only responsibility is to gain an understanding of the definition of a term as it is presented to you in any reference book or dictionary.



With all that being said I would like to thank you for your comment. I can see that you really put forth the effort to straighten this whole matter up. This whole topic on time boils down to if you or anyone thinks that time is a physical thing that exists in this universe and can have an effect on other physical things in this universe.

If all the others are not using my definition of physical, and my definition of physical is defined as something that is: of or relating to material things. of or relating to matter or energy.

Than I would say they are not describing time as a real physical object or phenomena.

This would mean that in actuality since physical as the others are using it to describe time, is not the physical that describes those things that are of matter or energy, then time is not a physical thing that exists as a thing in this universe that can have an effect on other physical things, and cannot do what other physical things can do.

This would rule out time being able to bend, dilate, or combine with other physical things in this physical universe. Time as the others describe it would only exist as a concept that exists only in non-physical form. Time would be only an idea or concept. This view of time is something that I agree with.

Just so that I do not come across as trying to tell you what you meant I will leave this open for you to agree or not with my understanding of what you said.

I guess the only thing that I want to know, and the only thing that pertains to this discussion is, do you think time is physical as defined as: of or pertaining to matter or energy.

 

[john 8]

Originally Posted by john 8
This is a poor excuse for not answering a question. My definition of physical is the definition of physical as it is found in a standard dictionary for the English language and for physics.

Stop avoiding answering the question. You say time is physical, so grab your dictionary, Get the correct definition, and tell me how you think time is physical.

http://dictionary.reference.com/browse/physical

Option 4.

Great now we are getting somewhere.

You sent me a link to dictionary. com. You noted option 4. Option 4 is: 4. pertaining to the physical sciences, esp. physics.


There are many things that pertain to the physical sciences, but just because something pertains to a field of knowledge does not prove or disprove the physical reality of a thing.

Is this the only definition of physical that you want to use when saying time is physical.

If so, this definition only tells the reader what physical means as it pertains to a field of knowledge. This definition does not give any evidence that time is a physical thing. It only tells me that the subject of time is part of the study of physics. We already know that.

So tell me how your latest definition has in any way cleared up this discussion that we are having on if time is a physical thing or not. You have now pointed out that time is part of physics, great, but that was already known and I did not have a disagreement with that definition of physical.

Again, I will ask you, is this the only definition that you want to use when stating that time is physical? There are six other definitions of physical, do you want to use any of those?

 

[Sjorris]

You are not required to come up with “more clear” definitions of anything.

Yes, I know, I chose the wrong words, please excuse me since English isn't my primary language. I was not trying to define time, but trying to come up with a reasonable description of what time actually is. Actually, come to think of it, this problem excists for all physical (meaning, as related to the science of physics) quantities, including energy, time, mass and position.

This whole topic on time boils down to if you or anyone thinks that time is a physical thing that exists in this universe and can have an effect on other physical things in this universe.

Obviously not, as was earlier stated, someone who would adopt this statement would clearly be crazy. Only physical (meaning, material) things can interact with physical things, but that does not mean physics is limited to those things. Physical (material) things are actually just a small part of physics, the majority of physics concerns concepts such as energy, mass and time. Energy and mass do not directly interact as material things do, however these quantities seem to show up in every theory independantly, and turn out to be so fundamental to the universe that they can not be left out when one wants to formulate a 'complete' physical (science of physics) theory, and are therefore assumed to be physical (as related to the physics).

This would rule out time being able to bend, dilate, or combine with other physical things in this physical universe. Time as the others describe it would only exist as a concept that exists only in non-physical form. Time would be only an idea or concept. This view of time is something that I agree with.

Just so that I do not come across as trying to tell you what you meant I will leave this open for you to agree or not with my understanding of what you said.

I guess the only thing that I want to know, and the only thing that pertains to this discussion is, do you think time is physical as defined as: of or pertaining to matter or energy.

I do agree that time is non-physical in the meaning of non-material, so I think we agree on that. However, time can 'bend' or 'dilate', but not in the classical sense of the word, this concerning to special relativity, but I assume this is not what you ment.
Time doesn't interact with material things, but it does say HOW material things interact. Einstein showed that 3-space isn't enough to accurately describe the position of any event/particle, and that the missing quantity is time. So, to describe any event you need 4 indepent variables (which are related of course, independent as known in the field of lineair algebra), so reality is four dimensional, with the four dimensions being 3 spatial and 1 time. So yes, time is a dimension (in the mathematical sense).

 

[john 8]

Hey Sjorris!

I was just thinking, you went to all the effort to suggest a link on physical, why haven't you sent me a definition of time? It seems to me that this whole matter could be quickly cleared up if you would just send me a physics definition of time. Why prolong this discussion? Just give me a good standard definition of time. Use anything really.

Go check in all of your books written by Einstein, Richard P. Feynman, Brian Greene, Lisa Randall, Stephen Hawkings, Michio Kaku, or any other physicist that you have, and check the glossary under the heading of time, spacetime, and tell me what you read.

Any description of how or in what manner time is a physical thing? Go ahead look.

Check the whole internet for the physical nature of time.

Why is it do you suppose that you just did not provide me with a link to some reference that backs up your claim the time is a physical thing? Why no plain good old standard definition of time? Maybe the lack of any definition or reference of time being a physical thing is the proof that indeed time is not the physical thing that you think it is.

Really think hard on this and try to find out why you believe time is more that just a consideration.

There are two ways man ordinarily accepts things, neither of them very good. One is to accept a statement because an authority says it is true and must be accepted, and the other is by preponderance of agreement amongst other people, as in the mindset of “I believe it to be true because so many other people believe it to be true.” There is a third way man accepts things and that is by first hand experience of things, this can be done by testing or applying data to the real world to see for yourself or just perceiving things in the real world.


Come on, show me some hard scientific proof that time is a physical thing (physical meaning of or pertaining to particles or waves)

Where is that confounded evidence? Don't think that I have not scoured the internet and many, many science books in search for where science has boldly and definitively stated how time is a physical thing, I have, and the jury is out, time is not a physical thing due to lack of evidence. It will remain as a concept until new evidence to the contrary is found.

The ball is in your court, have fun on your adventure in finding the truth.

I would really like to hear back from you on this.

 

[john 8]

Yes, I know, I chose the wrong words, please excuse me since English isn't my primary language. I was not trying to define time, but trying to come up with a reasonable description of what time actually is. Actually, come to think of it, this problem exists for all physical (meaning, as related to the science of physics) quantities, including energy, time, mass and position.



Obviously not, as was earlier stated, someone who would adopt this statement would clearly be crazy. Only physical (meaning, material) things can interact with physical things, but that does not mean physics is limited to those things. Physical (material) things are actually just a small part of physics, the majority of physics concerns concepts such as energy, mass and time. Energy and mass do not directly interact as material things do, however these quantities seem to show up in every theory independently, and turn out to be so fundamental to the universe that they can not be left out when one wants to formulate a 'complete' physical (science of physics) theory, and are therefore assumed to be physical (as related to the physics).



I do agree that time is non-physical in the meaning of non-material, so I think we agree on that. However, time can 'bend' or 'dilate', but not in the classical sense of the word, this concerning to special relativity, but I assume this is not what you meant.
Time doesn't interact with material things, but it does say HOW material things interact. Einstein showed that 3-space isn't enough to accurately describe the position of any event/particle, and that the missing quantity is time. So, to describe any event you need 4 independent variables (which are related of course, independent as known in the field of linear algebra), so reality is four dimensional, with the four dimensions being 3 spatial and 1 time. So yes, time is a dimension (in the mathematical sense).

You sound like a very down to Earth person who is just trying to understand what it is all about. If I have come across as harsh or impatient with you it is because of all the chatter about time being physical without anyone giving a scientific reference to back up their claim.

I want to help you clear something up. When you say that time can bend, are you saying this because you have personally experienced this or is this what you have been told?

If you think that time bends are you suggesting that a physical bending is occurring? If so, please tell me what is it that is sitting in a location and having force applied to it so that this form is altered. You see for something to bend that means that it has a shape and a location in space. In order to bend this thing a force has to be applied to it in order for the shape to change.

What you need to do is decide if time is a physical thing that is composed of particles or waves. Once you decide that then see how that conclusion fits with the idea that time bends or dilates or whatever else this thing is supposed to do.

Please just take this one step at a time. First and foremost, apply the known facts and laws of physics to the question of if time is a physical thing or not, and then when you have that stable data then proceed to see how the rest of the puzzle fits together.

Do not get confused with what you are being told to believe. Just figure out if time fits the true scientific definition of what it means to be a physical thing. Just that one step will clear up a lot of confusion, just re-examine what you know in a new unit of time and just see if you find time to be a thing that can be bent and all that other stuff.

Is time a physical thing per all standard references and definitions on what a physical thing is?

 

[Sjorris]

I never said time was a physical (material) thing, I thought I, and everyone else in this topic made this awfully clear.

The whole problem arose because you mixed up definitions and failed to acknowledge and/or understand that, mistakingly thinking that our statements were based on your definition of physical, therefore warping them. Basically, you performed ignoratio elenchi or a so-called red herring, which is a logical fallacy.
You continue to do this in your last post, stating that my already warped opinion (which actually isn't my own, you just think it is) about time is formed by one of the two 'bad' ways of accumulating knowledge and then you provide an (valid) argument about a third option. I have never ever read any authorative text concerning time (except for some texts concerning entropy determing the direction of time, but this is unrelated), and everything I posted here concerning time is self-taught.

Also, this forum is not for debating, it's for arguing. Stating a theory and then asking others to disprove doesn't prove your theory, and although it's a valid practice in debates, in arguments it's a bad habbit and frankly quite annoying.

Again, time is NOT a physical (meaning, material) object, it only is a physical (meaning, related to the science of physics), and yes, this is blatantly obvious, and yes, everybody already knows this. Time is a dimension though, to answer your original question.

 

[Sjorris]

You sound like a very down to Earth person who is just trying to understand what it is all about. If I have come across as harsh or impatient with you it is because of all the chatter about time being physical without anyone giving a scientific reference to back up their claim.

I understand, but this has been going on way too long. I won't be posting after this post, since I feel like I addressed the issue more than enough and am now done with it.

I want to help you clear something up. When you say that time can bend, are you saying this because you have personally experienced this or is this what you have been told?

I've never experienced time dilating, however I have enough trust in various authorities concering the subject of special relativity, and have seen more than my share of papers acknowledging time dilating experimentally to be sure enough to accept it as a fact.

If you think that time bends are you suggesting that a physical bending is occurring? If so, please tell me what is it that is sitting in a location and having force applied to it so that this form is altered. You see for something to bend that means that it has a shape and a location in space. In order to bend this thing a force has to be applied to it in order for the shape to change.

What you need to do is decide if time is a physical thing that is composed of particles or waves. Once you decide that then see how that conclusion fits with the idea that time bends or dilates or whatever else this thing is supposed to do.

Again, time is not a material object, so it can't materially bend.

Please just take this one step at a time. First and foremost, apply the known facts and laws of physics to the question of if time is a physical thing or not, and then when you have that stable data then proceed to see how the rest of the puzzle fits together.

Do not get confused with what you are being told to believe. Just figure out if time fits the true scientific definition of what it means to be a physical thing. Just that one step will clear up a lot of confusion, just re-examine what you know in a new unit of time and just see if you find time to be a thing that can be bent and all that other stuff.

Please, don't lecture me, it's unnecessary. Also, I've posted what my definition of physical was, and you failed to integrate this into your posts.
There never was confusion at my end, just on yours. I'm sorry now if I've been harsh, but I felt like pointing out your logical fallacies was the only way to settle this argument.

 

[epkid08]

Was this whole topic based on an argument over an arbitrary definition?

 

[CaptainQuasar]

With all this talk about time needing to be a material thing bending for time dilation to occur, I personally am waiting for john 8 to say "There is no spoon!" and arch his eyebrow dramatically as though he has said something profound.

⚛​

 

[petm1]

Sorry, this crazy person does think that time is physical. I am using the Webster's new world college dictionary fourth edition, and it states that time is a "duration; continuance", it also states that a duration is a "continuance in time" or "the time that a thing continues or lasts". All matter and waves are nothing more than duration, from our visible universe to a muon. Energy appears to me to be a movement of time, which is what can bend and fold making duration separable. We are only physical because we exist in the present, the moving part of our visible universe’s duration.

 

[Alfi]

What a difficult Webster's entry to read.
Time is, "the time that a thing continues or lasts"
Is that called a 'Self referral definition'?

 

[Sjorris]

Was this whole topic based on an argument over an arbitrary definition?

Not quite, but it evolved into it, sadly.

Sorry, this crazy person does think that time is physical. I am using the Webster's new world college dictionary fourth edition, and it states that time is a "duration; continuance", it also states that a duration is a "continuance in time" or "the time that a thing continues or lasts". All matter and waves are nothing more than duration, from our visible universe to a muon. Energy appears to me to be a movement of time, which is what can bend and fold making duration separable. We are only physical because we exist in the present, the moving part of our visible universe’s duration.

Could you elaborate on this a bit? Do you mean that time is physical in the material sense? In my opinion, matter and waves are more than just a duration, and energy is not just a movement of time. In fact, steady states still carry energy, and they're not time dependant, so to me it seems that energy can excist in systems which are invariant under time.

 

[Sjorris]

What a difficult Webster's entry to read.
Time is, "the time that a thing continues or lasts"
Is that called a 'Self referral definition'?

I think that was being said about duration, but duration was defined as duration, so technically it's a self-reference. Languages don't have axioms of some kind though, so you can't reduce all language to a finite set of definitions, so I'm guessing self-reference is inevitable.

Dictionary.com has a huge list of entries concerning time, see here

 

[Fredrik]

You need to think hard at how you came to the conclusion that time is physical.

No, but you need to cut this BS right now. Neither I nor anyone else had claimed that time is physical according to your definition until petm1 did it in #83, so stop claiming that I have.

If you have a question about science, then ask it. If not, I suggest you try to find something better to do than this.

 

[Dale]

I am not trying to construct a working theory of physics without time. You are adding some requirement to this time discussion.

You seem to think that I am trying to deflect the discussion, I am not. You have stated that time is not physical, so if that were true there would be two possibilities:
(1) Time is not physical, but it is essential to any correct theory of physics
(2) Time is not physical, so it is not essential to any correct theory of physics

Since this is a proposition of the form "A" or "not A" either (1) or (2) must be true. Which do you agree with?

If you agree with (1) then this argument is, as Sjorris pointed out, a purely semantic argument about the definition of the word "physical". However, if you agree with (2) then it is up to you to demonstrate that by providing such a theory.

I await your answer. I hope it is (2) because semantic arguments are boring.

 

[ChadRichens]

Let me start by attempting to mediate what's been said so far with a reiteration of the forum rules:

If you choose to post a response, address only the substantive content, constructively, and ignore any personal remarks.

The question this Topic creator intended to have answered was, "is time a 'dimension.'"

My favorite definition of Dimension is as follows:

A magnitude that, independently or in conjunction with other such magnitudes, serves to define the location of an element within a given set, as of a point on a line, an object in a space, or an event in space-time.

For the purposes of defining events in space-time, one of the variables included into the equation is time, which causes it to become a dimension by serving as a property that can be described by a real number and that defines the location of an element within an event in space-time in conjunction with other such properties that can be described by real numbers.

So from the preceding deductions, we can see that time is in fact a dimension, although I believe there is more to answer here, since another topic sprung up in the responses to this one in an attempt to define whether or not it was in fact a dimension.

That topic is: "Is time physical or merely a concept?"

My thoughts on time and what we should define it as:

A consciouss mind uses logic and deductive reasoning to attempt to explain what we observe. Time is a way for our consciousness to explain the changes our senses encounter in every day life.

In this explanation of time, it is merely a concept, and there is nothing physical about it.

In order to define an event in space-time, physicists usually interpret space as being three-dimensional, with time playing the role of a fourth dimension. Does this mean that time actually occupies a fourth dimension, or is it just the way we are able to percieve it? This is the question I think we should answer if we are to discover whether or not time is an entity that is composed of energy and/or matter or if it has any physical properties, and is a question that has multiple fields of study to answer to. We can't simply define time in physics without that definition satisfying all aspects of science or philosophy. Therefore the definition of time is highly controversial.
In my opinion, time is a concept with multiple meanings and applications that is referred to in too many ways by too many different fields of study for a single definition to be able to do it justice.

I apologize for the length of my response. I hope this is thorough enough of a response to get us back on track, and I welcome any constructive, substantive response to which I will do my best to respond promptly.

 

[Naty1]

The Decoding the Universe,2006, Charles Seife takes an information based look at our universe. His approach, examples, and perspectives are often quite different from other authors quoted in this thread.

Among other interesting discussions he says:

Gisin's experiments proved there was a fundamental conflict between quantum mechanics and relativity about the the nature of time... In 2002 he showed that (particle entanglement experiments revealed) the concepts of "before" and "after" don't apply to quantum objects in the simple way they do relativistic ones...Gisen's experiment showed it is impossible (with entangled particles) to show which is the affecter and which is the affector...
This is a ridiculous state of affairs

Absent this strange inconsistency between quantum and relativistic mechanics I would have suggested "time is the flow of information"...but the above renders that incomplete. I had thought it might work because it might even cover black hole interiors (information is hidden, time can be considered as space) and even the initial instant of the big bang.

More traditionally I have seen "Time is a measure of change" which I also like...

Anway, time is as "physical" (or not) as distance or information or entropy...the precise relationship between and constituents of mass, energy, time, space,information, forces,etc is NOT perfectly understood. Which are emergent and which are fundamental is unknown. But we have many useful tools, especially mathematical ones, for making and subsequently confirming/testing predictions...that's all science is.

 

[Alfi]

My favorite definition of Dimension is as follows:


For the purposes of defining events in space-time, one of the variables included into the equation is time, which causes it to become a dimension by serving as a property that can be described by a real number and that defines the location of an element within an event in space-time in conjunction with other such properties that can be described by real numbers.

So from the preceding deductions, we can see that time is in fact a dimension,

I can see where time is defined as a dimension, for the purposes of defining events, but, is it really a cause and effect though?
What is the 'it' ?in, the inclusion of a variable into an equation that causes 'it' to become a dimension?

my reading skills may be impaired this morning. Happy birthday to me. :)

My favorite definition of Dimension is as follows:

or was that tongue in cheek? favorite.

I'm starting to think that science has a gap between the math of time and the perception of time in a conscience being. Same as Quantum has a hard 'time' expanding into the Macro.
The 'now', I perceive, can only be part of me opening the silly box and looking at the cat in real time.

 

[ChadRichens]

What is the 'it' ?in, the inclusion of a variable into an equation that causes 'it' to become a dimension?

For the purposes of defining events in space-time, one of the variables included into the equation is time, which causes it(time) to become a dimension by serving as a property that can be described by a real number and that defines the location of an element within an event in space-time in conjunction with other such properties that can be described by real numbers.

 

[Fredrik]

I'm starting to think that science has a gap between the math of time and the perception of time in a conscience being.

The time perceived is the same as the time measured.

There is always a "gap" between measurements and what corresponds to them in the appropriate mathematical model. A set of postulates (yes, postulates) that tell us how to bridge that gap is a theory of physics.

This is true about all measurable quantities, not just time, and the only connection with consciousness is that a conscious human can be thought of as a really bad clock.

 

[Dale]

This is true about all measurable quantities, not just time

I agree. That is why I mentioned mass earlier in this thread. It is not as easy to define as john 8 thinks, and once you understand mass it makes time easier to understand.

 

[atyy]

The time perceived is the same as the time measured.

There is always a "gap" between measurements and what corresponds to them in the appropriate mathematical model. A set of postulates (yes, postulates) that tell us how to bridge that gap is a theory of physics.

This is true about all measurable quantities, not just time, and the only connection with consciousness is that a conscious human can be thought of as a really bad clock.

Surely time measured by an ideal clock is more like a microscopic quantity, but time perceived is more like a macroscopic effective quantity? Does our perception even resolve time differences of less than 1 ns? I know barn owls can do ~1 micro-second.

 

[Fredrik]

That's why I said humans are really bad clocks.

 

[atyy]

That's why I said humans are really bad clocks.

Just like a proton is a really bad point charge?

 

[atyy]

That's why I said humans are really bad clocks.

How about cases where temporal order becomes ambiguous?

Try the first and second demos here. The physical temporal order of the high and low pitches is the same in both cases - but not the perceptual temporal order.
http://www.tc.umn.edu/~cmicheyl/demos.html

 

[atyy]

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.

Here's an interesting quote from Pauli that seems close to what you're saying. The symbol "gik" is usually cconsidered "spacetime". Although the statement is made in the context of GR, I am reminded that even in SR, it is different "events" (Ludvigsen gives the example of lightning striking a tree) which are primary, and spacetime is constructed by assigning different numbers to different events.

‘The generally covariant formulation of the physical laws acquires a physical content only through the principle of equivalence, in consequence of which gravitation is described solely by the gik and these latter are not given independently from matter, but are themselves determined by field equations. Only for this reason can the gik be described as physical quantities’ (as translated by Giulini, http://arxiv.org/abs/gr-qc/0603087)

But what is matter? Ehlers (in Stamatescu and Seiler, Approaches to Fundamental Physics) says: Here “matter” is used to denote all physical entities besides gαβ, i.e. everything which carries localizable energy and momentum. ... this specification always contains the metric. Matter models studied in some detail include perfect fluids, electromagnetic fields, collisionless particle systems idealized by kinetic theory and, to a lesser extent, elastic bodies. In these cases the system of partial differential equations ... the relevant matter law admits a (locally) well-posed initial value problem.

 

[chiro]

Hi everybody. I just recently joined this forum because I have been reading through the various sections and find it a lot more stimulating than other discussion forums.

I have been thinking about this subject myself and I may have some idea of what john 8 is trying to get at so here's my two cents.

To define time in both a mathematical and a physically measurable sense in a unified form we turn to geometry.

Now I'm not going to repeat the disccussion on general relativity and how time is defined through the change in events because that has already been well discussed. What I will do however is state that given a universal geometry G which contains the set of all events (usually in mathematics we denote it as omega) possible in accordance with global set of processes in the universal system, contains the starting point for which I define time.

Given this geometry G, a time-line is defined as the path taken from an initial event A to a final event B. Any mathematical expression will suffice as long as they unambiguously differentiate one unique time-line from another.

So in this respect time is defined as the distance traversed within the global space-time. This distance is measurable using the same notion of length that is used in normal euclidean geometry (in this case the metric is given by the square root of the sum of the squares).

If one event lies in the global geometry G at a point P and a possible future event lies at point F in the geometry then time is defined purely as the path taken to reach F from P. We can measure this using advanced geometric techniques.

In a multidimensional geometric theory we can use a few tools that we have developed as a result of mathematics. The notion of relative measure (or angular measure) is important as well as the notion of absolute measure (defined from the metric). With angular measure we are defined a form of measure of two points relative to some origin. By using the properties of given geometries and by measuring as accurately as possible the results that are the projection onto our currently perceptible 3-space, we can infer a particular geometry that corresponds to a set of physical processes P and thus through a metric define what we mean by "time".

Now if we build the relation between our universal geometric structure G and a local intuitive
structure (i.e. a local R^3 structure with orthogonal axis) then we can relate distance in
the global structure G to corresponding distance in the intuitive structure. This essentially
establishes a link between "intuitive" time and "universal time". The process I describe is
akin to linking a string theoretic definition of time in multidimensional universe or one of time
in an einsteinian universe to that of a Newtonian universe.

Once the link has been made between the various theories all you need to do is use a geometric physical measuring device (eg a ruler) and a known physical process (such as the behaviour of light) to measure time as time directly correlates to distance.

If I'm wrong I welcome any comments as I have only really just started to learn this kind of thing properly so if I'm wrong I'd welcome a seasoned expert to fix up where an amendment is needed.

I hope this helps.

Matthew

 

[nutgeb]

This topic is not capable of a definitive answer. One can somewhat arbitrarily but perfectly reasonably create a coordinate system with 3 spatial dimensions and 1 time dimension. It happens to be useful in simplifying the mathematical portrayal of certain concepts of relativity. But the fact that it is mathematically useful for that purpose imparts it no unique significance to "spacetime" as a physical concept or system. For example, one could imagine an alternative coordinate system in which the defined "dimensions" include 3 spatial dimensions, 1 time dimension, 3 color dimensions, 3 density dimensions, 3 temperature dimensions, 3 pressure dimensions, etc. But our ability to define that coordinate system and use it in calculations does not mean that this system of "space-time-color-density-temperature-pressure" is somehow more physically "real" or "unique" than the individual categories of dimensions from which it is built. In the same sense, the concept of "spacetime" is no more real or meaningful than treating the spatial dimensions separately from the time dimension.

 

[Dale]

In the same sense, the concept of "spacetime" is no more real or meaningful than treating the spatial dimensions separately from the time dimension.

I disagree. If it can predict the results of experiments better then it is more real and more meaningful.

Otherwise why would we bother doing experiments? If the results of scientific experiments don't tell us anything about the "meaningfulness" of our scientific theories then we should have just stayed with pre-scientific superstitions.

 

[nutgeb]

I'm just saying that although coordinate system based on a "bent" spacetime with a "straight" geodesic traveling through it is convenient and useful, that happenstance doesn't disprove that on the contrary the geodesic is "bent" and the spacetime is "straight." We can disagree in our opinions about this but there is no way currently to come to a definitive conclusion because we don't know the physical mechanism by which gravity works. Both possibilities should be treated as scientifically reasonable.

 

[atyy]

I'm just saying that although coordinate system based on a "bent" spacetime with a "straight" geodesic traveling through it is convenient and useful, that happenstance doesn't disprove that on the contrary the geodesic is "bent" and the spacetime is "straight." We can disagree in our opinions about this but there is no way currently to come to a definitive conclusion because we don't know the physical mechanism by which gravity works. Both possibilities should be treated as scientifically reasonable.

I think what you said is true even with in GR.

Thorne, Black Holes and Time Warps, 1994: Is spacetime really curved? Isn’t it conceivable that spacetime is actually flat, but clocks and rulers with which we measure it, and which we regard as perfect in the sense of Box 11.1, are actually rubbery? Might not even the most perfect of clocks slow down or speed up, and the most perfect of rulers shrink or expand ...? Wouldn’t such distortions of our clocks and rulers make a truly flat spacetime appear curved? Yes.

 

[Dale]

Both possibilities should be treated as scientifically reasonable.

In this post you are referring to different interpretations of the same theory, that is not what I was objecting to above. I (perhaps mistakenly) understood you above to be talking about Newtonian mechanics and special relativity, where there are experimental differences.

Personally, I have never been terribly interested in different interpretations of the same theory, all that matters are the predictions a theory makes and how well those predictions agree with experiments. The stories we tell ourselves are not terribly important. I think that a person should be aware of all of the different interpretations and use each of them when convenient. The "default" interpretation should always be the simplest one.

That said, in the math of all modern physical theories time is a dimension, and the theories agree very well with experiment. The interpretation you use does not change the math. Therefore, IMO, the topic is capable of a definitive answer in the affirmative.