What is time?

[steve 9]

Originally Posted by Overdog

Well, all of my instincts tell me that time is somehow real, but until I can put a piece of it under a microscope, I can't prove it.

The best I can do is say that it is a concept, which may or may not have any objective reality.

Yes time is real to us. There are those things that physically exist outside of ourselves, and there are those things that we think of and exist only in our mind. Both are real to us. So your instincts are right, time is real to you. You have a concept of time. The question is, is time a thing that exist as something that is in the physical universe, or is it just a concept? Really that is what it boils down to.

Those of you that think that time is more than a mere concept and has some sort of physical properties, then just show some proof of this. Tell us what time IS. It should not be that difficult, if time is more than a concept science will give evidence of this. Where is this evidence? Do some research and find out what time is.

I would like to point out that there are more than 400 posts dedicated to this question and still no empirical data that provides evidence that time is more than a concept. One could conclude from this obvious fact that the lack of evidence for the assertion that time is a physical thing is a case against the idea that time is more than just a concept. If there is evidence that time is a physical thing, then why not just provide the evidence, what is the hold up? Give a definition, an observation, experiment, something concrete.

Enough of the double talk and talking in circles, what evidence is there that shows beyond a reasonable doubt that time is a physical thing?

Take a stand. Just tell us what you think time is. Is it like matter? Is it like energy? Start somewhere and build your case.

[steve 9]

Originally Posted by Michaelangelica

Um, Something humans use clocks to measure?

That is your evidence? Look, I really do not want to come across as some inconsiderate person, so do not take what I am about to say personally.

First thing, your statement says nothing about what time is. It is about clocks. This does not provide any insight into the nature of time.

I have come across this "clocks prove time is real" statement many times and I have to wonder if the person who thinks this is really aware of what they are saying.

If clocks truly "measure" time then how is this done exactly? What are the mechanics behind this occurrence? Have you given any thought to this? Are you suggesting that a wind up clock is being motivated by some influence outside the clock, and that this influence, force or energy is driving the gears in the clock?

If you want to use a clock as evidence that time is some sort of physical thing then please explain exactly how this works, what is the connection?

Tell me more about clocks and how they actually measure this thing called time.


Every measurement of time is based on what man decided that measurement to mean. Seconds, minutes, hours and so on are all man made. Time did not come pre-packaged in these units, man agreed on what to call these durations. Clocks measure how much of a pre-determined man made unit passed for a given motion. If something takes a minute of time, then that activity lasted for what man determined to be a minute. Time is the concept of man.



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.


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 is a clock measuring?

[Overdog]

Originally Posted by steve 9

Enough of the double talk and talking in circles, what evidence is there that shows beyond a reasonable doubt that time is a physical thing?

Take a stand. Just tell us what you think time is. Is it like matter? Is it like energy? Start somewhere and build your case.

In case your wondering what the problem is, I think it's this.

Let T be any theory which posits unobservable phenomena. There will always be infinitely many theories which are empirically equivalent to T but which are such that each differs from T, and from all the rest, in what it says about unobservable phenomena (for formalized theories, this is an elementary theorem of mathematical logic). Evidence in favor of T's conception of unobservable phenomena ("theoretical entities") would have to rule out the conceptions represented by each of those other theories. But, since T is empirically equivalent to each of them, they all make exactly the same predictions about the results of observations or experiments. So, no evidence could favor one of them over the others. Thus, at best, we could have evidence in favor of what all these theories have in common--their consequences about "observables"--we could confirm that they are all empirically adequate--but we could not have any evidence favoring T's conception of unobservable theoretical entities. Since T was any theory about unobservables, knowledge of unobservable phenomena is impossible

Scientific Realism (Stanford Encyclopedia of Philosophy)

[modest]

I'll point out for anyone that is not familiar with steve 9, that his intention is to argue from the premise of a false dichotomy. He has carried this over from other forums that have come quickly to the conclusion that he is a troll.

His questions are of the form: either time is a real physical thing or not. Because real is not equivalent to physical there is no simple yes / no answer to his question. Yet steve will resist any attempt to rephrase the question or give more than a black and white yes / no answer as Craig just did. Notice from steve's post above:

Originally Posted by steve 9

One could conclude from this obvious fact that the lack of evidence for the assertion that time is a physical thing is a case against the idea that time is more than just a concept.

Here time is either a "physical thing" (which of course it is not) or it's "just a concept". This is the very definition of a false dichotomy or false dilemma. Any detailed exploration of what time really is (such as I tried in post #330) is rejected by steve out of hand and goes nowhere.

~modest

[CraigD]

Originally Posted by steve 9

So CraigD, What is time? You mention classical mechanics REQUIRE this thing called time, but you do not actually mention what this time thing is.

I did not, because nothing I need to do requires that I use the term “time” in an unqualified context. I wrote

Originally Posted by CraigD

To describe energy, or the simpler concept, velocity, one must describe objects with at least 1 space-like, 1 mass-like, and 1 time-like, dimension.

by which I mean that to describe a classical mechanical system in which the word “velocity” means anything, I must have at lease one dimension which I call “position” or “length”, and another dimension, which I call “duration” or “time”. Neither dimension is more or less “real” to me – the term “real” is not even defined or useful to me in the context of describing my system.

I miswrote when I stated that one needs a dimension called “mass” to describe velocity. Only position and duration is need. “Mass” is needed in to describe energy.

With one or more “length”, one “mass”, and one “duration”, I can use simple classical mechanics, extended slightly by the formalism of Relativity, to answer nearly practical questions I encounter about the physical universe. Without duration, I can answer some, but far fewer questions. Thus, I need duration, or time, which makes it, within the symbolic and perceptual factory that is my mind, and effectively both all of me and the entire universe of which I’m aware, very important and real

Originally Posted by steve 9

Stop beating around the bush and just tell us what you think time is.

I have, several times in this thread, with and without your insistence, steve9

Steve9, what do you hope to accomplish by repeatedly, and without increased qualification and specificity, asking “what is time”? What value is what you hope to accomplish to anything that I, or any other user of physics, do when using physics?

It would be much easier to understand what you are asking, if you would explain why you are asking it. Judging by the many objections to your approach in asking your question, many others find your approach bizarre, un-useful, and annoying. If you would explain why you are asking “what is time?”, your questions might be greeted with more enthusiasm.

[ldsoftwaresteve]

CraigD:

Steve9, what do you hope to accomplish by repeatedly, and without increased qualification and specificity, asking “what is time”? What value is what you hope to accomplish to anything that I, or any other user of physics, do when using physics?

It would be much easier to understand what you are asking, if you would explain why you are asking it. Judging by the many objections to your approach in asking your question, many others find your approach bizarre, un-useful, and annoying. If you would explain why you are asking “what is time?”, your questions might be greeted with more enthusiasm.

I was asking myself the same question.

Although I think time is a concept allowing us to comprehend change, I would not demand that someone who thought it was 'real' in the sense that it exists outside of ourselves show me what it was. We all know what it's used for and we would not need to be shown what 'in' was or 'next to' was. I think that for now, to see how much people are at least considering the possibility that it might be just a tool for comprehending the reality of change, we have taken this discussion about as far as it could be taken.

Perhaps after this settles in, we could have a discussion about what is driving change if it isn't time. Because, after all, things do change and it seems reasonable that there is a universal cause for that.

Perhaps steve9 needs to tell us what that is.

[Overdog]

Originally Posted by ldsoftwaresteve

CraigD: I was asking myself the same question.

Although I think time is a concept allowing us to comprehend change, I would not demand that someone who thought it was 'real' in the sense that it exists outside of ourselves show me what it was. We all know what it's used for and we would not need to be shown what 'in' was or 'next to' was. I think that for now, to see how much people are at least considering the possibility that it might be just a tool for comprehending the reality of change, we have taken this discussion about as far as it could be taken.

Perhaps after this settles in, we could have a discussion about what is driving change if it isn't time. Because, after all, things do change and it seems reasonable that there is a universal cause for that.

Perhaps steve9 needs to tell us what that is.

I agree 100%.

[modest]

Originally Posted by ldsoftwaresteve

Perhaps after this settles in, we could have a discussion about what is driving change if it isn't time. Because, after all, things do change and it seems reasonable that there is a universal cause for that.

I think a good example of change is radioactive decay. For example, if we have a sample of carbon and we measure how much carbon-14 is in it then we can predict how quickly the C-14 will turn into nitrogen. It's a very basic process in nature that happens at a predictable rate. One gram of C-14 will be half a gram in 5730 years.

So, change is a good word to describe what's happening. Certainly carbon is changing into nitrogen via beta decay. But, change is incomplete. It doesn't completely describe the situation. Saying one gram of C-14 changes into a half a gram of C-14 is not the whole story. For the whole story we have to say how quickly it changes, how much time it takes to change.

So, it's not so much that time 'drives' change. It's more that change is meaningless without time. Consider change in position. Let's say there is a ruler that is one meter long lying on a lab table. We roll a ball from the zero position to the 100 centimeter position. So then:

Change = 1 meter

I wouldn't say time drove that change or caused that change. But I would say there is no way to discuss how fast the ball went without a very real process of the universe called time. Speed is change in position divided by change in time. If it took the ball one second to change position then the ball moved at one meter per second.

Change requires both space and time - two dimensions. It is impossible to describe change without both. So, time is not just a human concept. It is a human concept that describes something real about the universe.

~modest

[Overdog]

Originally Posted by modest

...
So, it's not so much that time 'drives' change. It's more that change is meaningless without time....

I wouldn't say time drove that change or caused that change. But I would say there is no way to discuss how fast the ball went without a very real process of the universe called time. Speed is change in position divided by change in time. If it took the ball one second to change position then the ball moved at one meter per second.

Change requires both space and time - two dimensions. It is impossible to describe change without both. So, time is not just a human concept. It is a human concept that describes something real about the universe.

~modest

Hmmm. Sounds like you at least agree it is a concept, one which allows a meaningful understanding of change...

But how can you know it describes something "real"?

[modest]

Originally Posted by Overdog

Hmmm. Sounds like you at least agree it is a concept, one which allows a meaningful understanding of change...

But how can you know it describes something "real"?

Uh... are you sure you read what I wrote?

Real change requires real movement. Nothing can change without moving. No example can be given otherwise.

Real movement requires real time. Nothing can move without time. No example can be given otherwise.

~modest

PS - change is not a basic physics concept. Change is how humans think of movement. The more fundamental of the two is movement. More fundamental than movement is space and time.

Time, Distance, and Mass are the fundamental units of physics.