Uncovering the Mystery of Time: The Search for Physical Evidence and Definition

[Danger]

"Time is nature's way of making sure that everything doesn't happen all at once."

Damn! You beat me to it!
The phraseology is a wee bit different than I usually quote, but essentially the same. As much as it can be considered a joke, it's also true. Really, causality rules (as far as we know).

 

[meopemuk]

This is true of any fundamental physical property. You should have the same problem with mass, length, charge (etc.) as you have with time. Mass is that which is measured by a physical balance; length by a ruler...and your time is what is measured by the watch on your wrist.

There seems to be a significant difference between time and other properties, like, mass, length, charge,... These other quantities are properties of the physical system that we observe. Their values depend on what kind of system we are observing and what state the system is in.

On the other hand, time can be measured (you can look at the watch on your wrist) independent on the physical system you are studying. You can measure time even if there is no physical system to study. So, time is not a property of physical systems. It is rather an attribute of the observer or of the reference frame.

Eugene.

 

[incandescent]

it depends on which "if" you're referring to. I'm not dealing with the first "if not" (whether it is true that time itself had no existence "before" the big bang - that's outa my pay grade), but, if it is not true that there's a Big Crunch, i think it's safe to say that time will have no end, probably will continue to pass even after the thermodynamic heat death of the universe. (when everything becomes the same temperature and there is no gradiant of temperature, then no energy can be expended to push anything around or make anything happen. i think then the universe would become static, but even though there could exist no clocks to tick, there would still be the physical stuff called "time".)

According to what you said, you have the idea that we are moving in time. But, such physical existence of time has not been proved by experimental methods. How do we know that we are correct with this? On the other hand, I must have the educated guess that we are moving in space and that this motion can be confirmed by millions and millions of daily experiences.

no, no, no, we accept that reality exists (WTF that means), but we don't know exactly what reality is. at one time human beings thought that the most indivisible component of matter was atoms. that's how they got their name. but we now know that there are particles of stuff smaller than atoms. like our pre-Rutherford times, in the same way we have to accept that we don't know what, precisely, reality is. we're still figgering it out. but we know it exists and we observe some properties and relationships in it. when such observations follow a description (with reduced "bits" in the description so that we infer some generality in it) that is virtually always accurate (that is, congruent to observation), we call those descriptions "laws of physics". in those laws of physics is a parameter we call "time" that we relate to the ticking of clocks. likewise, we don't know precisely what time is, but we observe properties of it (like the arrow of time). we know some things about it, but not everything. however some unexpected properties about time were discovered a teeny bit longer than a century ago (sorry for the self-reference to time).

So, you state that time is a parameter, but later you say that this parameter has properties like the arrow of time. I understand that you are referring to a flowing of time in a certain direction or to what we can call as a mobile parameter?

i'm not disputing that. the question was/is not: "does time exist?" nor even "how do we know that time exists?" but is "what is time?"

Excatly, and until this point time has been proved to be a concept and a measurement. Is this all what time is?

 

[incandescent]

didn't make very many conclusions other than we don't know exactly what time is. (because that phemonenon is a subset of what we call "reality" and we don't the hell know exactly everything about reality. there are unanswered questions in physics. some of these questions will likely get answered in the future, but not likely all, and even if all current unanswered questions will get answered some day, in the meantime more questions without answers crop up.

So, we don't know what is time beyond an accepted measurement or parameter, we have not perceived its physical existence at all by experimental methods.

It is, I think, necessary to review this matter about time, because it seems to me that we are giving characteristics to the unkown, and it appears that modern science doesn't work in this way anymore. If the unknown is acceptable by science as part of it, tomorrow morning religion and magic must be accepted in science as well.

i did not answer that as a definition (i think the Wikipedia lead is a perfectly good definition, for all i know), but i was only saying is that there is no completely sufficient answer to exactly what time is, because we, the human race, don't know.

Have you made yourself a question like: What if time doesn't exist as we think it does and we must perform a deep review about it?

I think that we are playing a big risk giving characteristics to what we don't know what it is and to what we don't perceive at all.

you have no memories?? no planning or anticipation of future events?? do you drive a car? i do not understand how anyone can safely drive a car and not detect with their consciousness any physical passage of time. i don't get it.

Lets see, I video recorded my children playing in the park. Such video is showing me the motion of my children going around. The video cassete is like my memory, and yes, I define such events of the film as part of the past. I recognize, however, that this "past" is a status given to the measurement called time. My senses can perceive motion, and when I have no a clock or a calendar in my hand, I can observe the seasons of the year, I know that after a four season the Earth has orbited around the Sun.

I counted the rounds and I say, my older child has gave 15 rounds around the Sun(15 years), and my older child has made 12 rounds around the Sun (12 years). Do I need time for this? I guess no. But, I cannot do it in viceversa, because I must have the perception of motion of things around in order to obtain the measurement of time.

What I perceive is motion, of course that many call our rounds around the Sun as years of time, but still those years are a measurement and are not physical existent.

anything that moves or has changing physical parameters detects the passage of time.

I have been searching experiments made in psychology about the perception of time. No results were successful, because our perception of time wasn't a sensorial event. People used to think that time slowed when they got sick, other felt the same when no light or sound was perceived, and when lots of motion and sound around was perceived or the individual was very busy, his perception was that time passed faster.

It was a subjective perception of time, nothing objective.

Physics, as far as I know, is not based in subjective perceptions but in objective perceptions of the universe.

 

[incandescent]

Time is simply what is measured by a clock in your reference frame.

Thanks, I got this one as well : Distance is what is measured by a ruler from my point of observation.

This is in a general view of this kind of expressions. Can we please go to specifics?

Lets see, I cannot measure Distance itself because Distance is a numerical description of how far apart objects are one from another. I can measure your distance from your house to your job place, as an example.

I cannot measure Time itself because Time is a numerical description of how long an object takes to move from one place to another. I can measure your time moving from your house to your job, as an example.

Time cannot dilate. Dilation applies to the duration of physical processes. If a certain process takes time T in your reference frame, then the same process will take a longer time (measured by your clock) if the physical system is moving with respect to you. Similarly, the duration of the process will be longer if the system is in a lower (more negative) gravitational potential.

Eugene

I read in Wikipedia the following:

Time dilation is the phenomenon whereby an observer finds that another's clock which is physically identical to their own is ticking at a slower rate as measured by their own clock.

I think that this definition is not accurate. A clock of another person or in a different location can give a different data than your's by many reasons, even malfunction.

I undesrtood since I was a child that if many different answers are given about the same matter is because no one knows what is going on.

 

[SpitfireAce]

I think space-time's existence is independent of the the existence of observers. One would think that gravity existed before us observers did, since we have so many cosmological theories assuming its presence "back then". If gravity existed, then space-time existed. And if space-time existed, that means time has some universal reality and can't be a figment of our imagination right?

"I counted the rounds and I say, my older child has gave 15 rounds around the Sun(15 years), and my older child has made 12 rounds around the Sun (12 years). Do I need time for this? I guess no. But, I cannot do it in viceversa, because I must have the perception of motion of things around in order to obtain the measurement of time."

maybe speed is more fundamental than time, but then speed must be counted by something other than time, like cycles, but one would need a universal cycle to dictate the various events in space-time

 

[incandescent]

I think space-time's existence is independent of the the existence of observers. One would think that gravity existed before us observers did, since we have so many cosmological theories assuming its presence "back then". If gravity existed, then space-time existed. And if space-time existed, that means time has some universal reality and can't be a figment of our imagination right?

I tried like you have made right above, to use logic as well to check about the existence of time, but modern science with its tool known as the scientific method rejects any theory based in logic alone.

 

[SpitfireAce]

Damn! You beat me to it!
The phraseology is a wee bit different than I usually quote, but essentially the same. As much as it can be considered a joke, it's also true. Really, causality rules (as far as we know).

thats ok, I beat him to it, post 3 I think he copied me

 

[SpitfireAce]

yep, I didn't get very far..

there is a simple time which is the number of cycles that can occur while an object moves from point A to point B...
there is a complicated time which is this... an event is nothing more than an instantaneous acceleration (I can't think of any instantaneous phenomena that can't be simplified to a change of motion of something)...2 instantaneous accelerations can occur in the same spatial location but can be separated in time, meaning one happens a certain number of cycles after the other, the cycles are of course being counted by the observer, who notes the difference in cycles between the two instantaneous accelerations... But where does this temporal difference come from? Well one mechanism that could account for temporal separation between things is due to the fact that objects travel at different constant speeds which according to the Lorentz transformation should cause observers to measure different numbers of cycles between the instantaneous accelerations of the different things. This is a subjective mechanism though, so if there were no observers this perceived time discrepancy would not occur and thus talking about time at all without observers would be meaningless. Is there some objective time separation mechanism and thus objective time? Some objective principle of simultaneity. If there is, then what exactly is the universal and objective cycle by which objects have a temporal existence and why isn't this cycle thrown off by the objective principle of simultaneity? To find the answer we return to simple time. It is essential that it takes time to cover distance. Objects are separated by distance, and an instantaneous acceleration must be caused by a force from another object... because objects are separated in space and instantaneous action at a distance is impossible, some number of cycles must pass while one object is traveling through space to cause the acceleration of another... thus two events can not be simultaneous, this is our objective principle of simultaneity, which comes from distance. But.. are we sure that distance is objective?

far as I got in my "logic"... but you reach a point where you start going in circles until you lose your train of thought

yawn, it's too late for a discussion like this, but I will think this through to the end tomorrow morning...and uncover the nature of time... ill get it to you all asap

 

[NoTime]

"Time is nature's way of making sure that everything doesn't happen all at once."

Unlike Xez and Danger, I'll say the Speed of Light keeps everything from happening at once.

 

[ice109]

Unlike Xez and Danger, I'll say the Speed of Light keeps everything from happening at once.

speed of light/time: same thing. they're tautologically defined anyway.err i guess that's distance and C but w/e

 

[Robert100]

Books on Time: Which do you suggest?

I too am interested in learning about the nature of time, about its very ontological reality (if, indeed, time has any reality at all.) I know that modern physics has no firm conclusions on this issue, but I want to read about the various views that serious thinkers have developed about time.

Would readers of this forum comment on the following books/authors?

I am presently reading through "The Arrow of Time" Peter Coveney and Roger Highfield, and it appears very good.

A more popular text that also appears good, but in less detail than the above, is "About Time: Einstein's Unfinished Revolution" by Paul Davies.

Any comments about the following books? (I haven't read them yet)

"World in Process" John A. Jungerman Description of the ideas of modern physics and cosmology; also connects those ideas to process thought.

"Time's Arrow and Archimedes' Point: New Directions for the Physics of Time" Huw Price. Price has criticised several points made by Coveney and Highfield, and his name comes up a lot. Is this philosopher's work considered on par with the best writing on time by physicists?

"Travels in Four Dimensions: The Enigmas of Space and Time" Robin Le Poidevin

"The End of Certainty" Ilya Prigogine.

"The End of Time" Julian Barbour - Here Barbour argues that time literally is an illusion, and that we live in a timeless reality.

"Time Reality" - Victor Stenger.

Any suggestions or constructive criticism on any of these books/authors would be most welcome.


Robert

 

[cristo]

I too am interested in learning about the nature of time, about its very ontological reality (if, indeed, time has any reality at all.) I know that modern physics has no firm conclusions on this issue, but I want to read about the various views that serious thinkers have developed about time.

Would readers of this forum comment on the following books/authors?

I am presently reading through "The Arrow of Time" Peter Coveney and Roger Highfield, and it appears very good.

A more popular text that also appears good, but in less detail than the above, is "About Time: Einstein's Unfinished Revolution" by Paul Davies.

Any comments about the following books? (I haven't read them yet)

"World in Process" John A. Jungerman Description of the ideas of modern physics and cosmology; also connects those ideas to process thought.

"Time's Arrow and Archimedes' Point: New Directions for the Physics of Time" Huw Price. Price has criticised several points made by Coveney and Highfield, and his name comes up a lot. Is this philosopher's work considered on par with the best writing on time by physicists?

"Travels in Four Dimensions: The Enigmas of Space and Time" Robin Le Poidevin

"The End of Certainty" Ilya Prigogine.

"The End of Time" Julian Barbour - Here Barbour argues that time literally is an illusion, and that we live in a timeless reality.

"Time Reality" - Victor Stenger.

Any suggestions or constructive criticism on any of these books/authors would be most welcome.


Robert

I've not read any of those, but a book on this subject that I enjoyed was called "The River of Time," written by Igor Novikov.

 

[Fra]

I undesrtood since I was a child that if many different answers are given about the same matter is because no one knows what is going on.

If your point of the thread is that we seem to not exactly understand time (as well as many other things) to the point where we can find a simplefoolproof logical definition of things I agree with you.

Some things, like the arrow of time, and the exact definition of time and howto make a clear definition between dynamics and the subject of dynamics doesn't seem quite understood yet. At least I don't understand it yet, I can't speak for others.

But fortunately the world amazingly allows significant progress in despite of imperfection. I think of time as a parametrisation of our expected future and past, to the extent of our incomplete understanding. Like a relation between what we know, and what we expect to happen next. The amazing part seems to be how it is so remarkably "stable" in despite of the fuzzy foundations.

But by the same token, space is somewhat fuzzy too.

But the fact that things are not perfect, doesn't prevent us from finding concepts extremely constructive.

/Fredrik

 

[rewebster]

If your point of the thread is that we seem to not exactly understand time (as well as many other things) to the point where we can find a simplefoolproof logical definition of things I agree with you.

Some things, like the arrow of time, and the exact definition of time and howto make a clear definition between dynamics and the subject of dynamics doesn't seem quite understood yet. At least I don't understand it yet, I can't speak for others.

But fortunately the world amazingly allows significant progress in despite of imperfection. I think of time as a parametrisation of our expected future and past, to the extent of our incomplete understanding.

/Fredrik

I partially agree ---time has too many definitions and too many interpretations when it comes to whether or not--or how it is 'used'---


"I think of time as a parametrisation" is a good way to think of it for me.

 

[rbj]

According to what you said, you have the idea that we are moving in time. But, such physical existence of time has not been proved by experimental methods.

if you have anticipated an event (such as picking up your coffee mug as you are reaching over) and that anticipated event in your mind has changed roles to a memory of that event, you have experimentally measured the existence of time. i can say that confidently because we ain't defining time (for the purposes of ascertaining its existence) anymore specifically than that. later, if we want to do Einsteinian experiments, we need to construct caesium clocks and refine our definition or time to measure these other properties of time that we learned about a century ago. but to prove mere existence, the fact that you drive a car safely is sufficient.

How do we know that we are correct with this?

we are not saying enough about time (in this crude existence experiment) to be incorrect about it. all we are saying, that our experience of future events (that are anticipated) that change in status to memories of past events, is sufficient to tell us that time (tautologically defined as just that experience) exists. then...

On the other hand, I must have the educated guess that we are moving in space and that this motion can be confirmed by millions and millions of daily experiences.

... because we never have the experience of memories of past experiences transforming to anticipated future events (deja vu is something else), we can measure a property about time that differentiates it, qualitatively, from space. as you might expect, that property is called the "arrow of time". the fact that "millions and millions" daily confirm motion confirms not only the existence of space, but also the existence of time. motion has no definition, no explanation, without the pre-existing concept of time.

So, you state that time is a parameter, but later you say that this parameter has properties like the arrow of time. I understand that you are referring to a flowing of time in a certain direction or to what we can call as a mobile parameter?

"mobile" parameter is not in my lexicon.

Excatly, and until this point time has been proved to be a concept and a measurement. Is this all what time is?

no, we don't know "all what time is". if anyone thinks we do, they should be reminded of all we thought about time in the 19^th century. there may very well be properties and explanations about time that the human race will learn about someday in the future (talk about a self-referential point). i don't know how, but possibly some astrophysicists will be able to experimentally measure exceptions to the property of the arrow of time, but maybe they will never do that. i doubt anyone will ever create a black hole in the lab to do such experiments.

 

[rbj]

So, we don't know what is time beyond an accepted measurement or parameter, we have not perceived its physical existence at all by experimental methods.

by what we have defined time to be, we certainly have "perceived its physical existence". it doesn't define or describe it completely, but we know it exsits.

It is, I think, necessary to review this matter about time, because it seems to me that we are giving characteristics to the unkown,

nobody disagrees with that. that's what Alfred Einstead was doing 100 years ago: "review[ing] this matter about time."

It was a subjective perception of time, nothing objective.

Physics, as far as I know, is not based in subjective perceptions but in objective perceptions of the universe.

i guess, because we actually read the instruments we use to measure stuff, everything ultimately is subjective. perception is (at least the beginning of) measurement. measurement is one aspect of perception. i also believe that it becomes less so (and more objective) as we refine our instruments and more of the decision making (the quantization of measurement, which is really what an analog-to-digital converter does) is done by these mindless instruments, the more objective our perception of whatever phenomenon is.

our perception to time gets more objective (as far as i believe) as we tie the measurement of time to, what we believe are stable physical processes such as "the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom". but someone still is counting the cycles of this periodic function (which is perceptual) and we are assuming by definition that each cycle of this radiation corresponds to an equal measure of this stuff we call "time". but maybe it isn't (and we redefine the second by some other means in the future). but our present objective perception and measure of equal portions of this stuff called "time" is now, by human definition, directly coupled to periods of this alledgedly periodic radiation.

 

[rewebster]

well, one of the basic principles of Physics is:

if you don't know what something is--





-name a particle relating to it

 

[russ_watters]

i guess, because we actually read the instruments we use to measure stuff, everything ultimately is subjective. perception is (at least the beginning of) measurement. measurement is one aspect of perception. i also believe that it becomes less so (and more objective) as we refine our instruments and more of the decision making (the quantization of measurement, which is really what an analog-to-digital converter does) is done by these mindless instruments, the more objective our perception of whatever phenomenon is.

The fact that some scientific instruments require skill to use does not make the readings we get from them subjective.

And that is, in any case, irrelevant to this thread, as the same problem in using an a manual, analog stopwatch exists for a ruler.

This is true of any fundamental physical property. You should have the same problem with mass, length, charge (etc.) as you have with time. Mass is that which is measured by a physical balance; length by a ruler...and your time is what is measured by the watch on your wrist.

And I said the same thing as well...

Incandescent, your mind is made up and you are unwilling to learn. Sorry, but there isn't anything we can do to help you at this point. But the fact that you refuse to understand time does not mean time does not exist or that others don't understand it.

Thread locked.

 

[nrqed]

About Time: reply to Incandescent

I am sorry the time thread was locked because I think it raised very important issues.

First, I want to point out that ultimately, the only type of measurements we ever make are position measurements. We never directly measure mass and we never directly measure time either. We only measure position. We measure mass indirectly by recording the position of a pointer on a scale, for example. We measure time by recording the position of a pointer on a watch or the change of position of electrons produced by the emission of photons emitted by an atomic clock. And so on.

So it all boils down to position measurements.

Obviously, the world is not static. Relative position of objects keep changing. Time is therefore the notion used to organize the order in which those position changes occur.

But I think there is something very deep to answer here.

For some, this may sound like a purely philosophical debate and they might say that it has nothing to do with physics and be annoyed by this type of debate. But there has been several examples in history where trying to understand some issues that were apparently unanswerbale led to major breakthroughs in our understanding of the universe. As a simple example, wondering why the inertial mass happens to be exactly the same as the gravitational mass led Einstein to something important. I am sure that some 100 years ago, people would have reacted to this question with impatience and would have deemed it more philosophical than scientific.

As another example, the question of whether an entangled photon pairs exits in specific states before being observed or are really in superposition of states seemed unanswerable until Bell thought about it and showed hoe the issue could be resolved.


I think that the nature of time is one of those deep issues. And that a debate on this is really worthwhile. It is worthwhile to hear everybody's opinions and questions.

Special relativity and especially general relativity have shown us that there is a dynamical aspect to the flow of time. But it feels to me that we haven't gone far enough in understanding this. I think that we need to understand how other forces interplay with time as well.


For example, let me thrown in a simple question. A key point is that, it seems to me, measuring time is always a question of relative measurement. We compare the time between at least two processes. In that sense, there is no absolute notion of time (and I mean absolute here in a different way than the absolute of the Newtonian time relative to the relativity of the Einsteinian time. I am not talking about comparing time between two frames. But the simple act of measuring time in a single frame).

Noe let's say we use a pendulum and an atomic clock to measure time. We can time the pendulum using the atomic clock or vice versa. We can then have the relative time between the oscillation of the electrons in the atoms and the oscillation of the pendulum. One phenomenon is gravitational and the other is electromagnetic. Now bring another atomic clock made of the same atoms. The atoms are different. And yet they will oscillate at the same relative frequency to the pendulum as the first atomic clock. What determines the rate of oscillation of the atomic clock? If we see time as simply a parameter to label differents states of evolving systems, what determines the rate at which the updates of the atomic clock are made? How does it "know" to update itself relative to the rate of oscilaltion of the pendulum at precisely the same rate as the first atomic clock was doing?

To me, it seems that we are holding on to an absolute view of time, but it's a different notion of absolute than the one that was pulverized by Einstein (which was the Newtonian absolute notion of time between frames).

Now, what people would say is that any Cesium atomic clock (say) vibrates at the same frequency because the same forces are acting. But that would mean that there shoudl be an absolute notion of time built in in the physics. And the pendulum should also have an absolute notion of time built in such that it will update itself at the same rhythm relative to any atomic clokc made of the same material. So we assume some notion of absolute time built in separately in both the pendulum and the atomic clocks.

It seems to me that we are still holding on to some notion of absolute time. It would seem to me more logical to only talk about the relative time between events (even in a given frame) but that would mean a deep revamping of our entire understanding of the physical laws.


Just my two cents...

Patrick

 

[nrqed]

Just to add to my previous post.

Another way of explaining what I mean by our use of absolute time (and maybe a clearere way) is the following. Let's say that you have the pendulum and the atomic clock next to each other. You solve the equations and ask: after 100 seconds, say, how many oscillations will the pendulum and the atomic clock have gone through? You plug in the numbers, and verify experimentally that it checks out.

Now, an aside is that the time used is really not an absolute quantity. It is really a relative quantity, that its it would have to be read on your watch, say.


So it's better to say: how many oscillations will have the pendulum go through when the atomic clock will have gone through a predetermined number of atomic oscillations "X". This make sit clear the relative notion of time measurements.

Now my main point: the way we would do this is to put "X oscillations" in the equations for the atomic clock, solve for the time "t" in those equations, plug this value back in the equations for the pendulum and find the number of oscillations of the pendulum.

My point is that we are assuming that the time "t" used in both systems is the same! This is what we mean by the fact that we are still using an "absolute" time. Maybe that's not the best way to put it. Maybe I shoudl say that we are using a universal time for systems that are driven by completely different forces.

And that bothers me

To me, this is akin to using the same mass for inertia and the gravitational force without being bothered by it.

It feels to me that this is telling us that there is something much deeper and fundamental that we are missing about the meaning of time, the same way the equivalence between the inertial and gravitational masses was pointing to a revolution in physics.

And I haven't even talked about the problem of the arrow of time yet!


My two cents...

patrick