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

[incandescent]

Hello,

One of the great marvels of science appears to be the existence of time.

I have been searching for the scientific evidence of such physical existence of time but I have foundd none.

This is amazing for me because I understand that several tests have been made to proved a dilatation of time but time itself has been never prove as existing by experimental methods.

How is this possible?

As far as I can understand science in general, at this step in our knowledge, the physical existence of time should be a priority goal.

I went inclusive to Wikipwedia as my last resort and the only definition of time is given as data or quantities of data, but nothing that guide us to the certainty of such physically existing and flowing time.

Wikipedia appears to recognize that time cannot be defined by physical means, and this bothers me a lot. If time is not physically existent, then how we say that time flows and dilates?

Does someone have any contribution which can lead us to establish a solid definition of time with its correspondent evidence through the requirements established by the scientific method to prove its physical existence and flowing?

Thanks.

 

[Sojourner01]

The only truism I can come up with is that it must be something, since we experience it.

I believe that this is a precept of most philosophies; that human experience has some basis in 'real' 'reality', even if it isn't the most direct representation.

Can anyone with experience in GUTs tell me whether there are any that consider time to be an otherwise identical dimension, or is it fundamentally different to the spatial dimensions in all theories?

 

[SpitfireAce]

lol, are you searching for the ether of time? space and time are dimensions, information needed in order to specify location in our universe... time does not flow or change, you move through time, just as you move through space, the main difference is that you have some default motion through time but not through space, you can't however move through space without affecting time. When one says... time dilates, all that means is that they are moving slower through time (thus time passes slower) because they are moving faster through space. There's sort of an equilibrium between space and time. We are at one end were we move full speed through time and stand still spatially, and at the other the photon who moves at full speed through space and thus does not move through time. There is nothing mystical here, but this is a cool quote... "time is nature's way of keeping everything from happening at once" The fact that things change can be your physical proof of time.

 

[kanzure]

Although there is a mathematical basis to "dimensions," we really do not have evidence that time is a dimension. In statistical thermodynamics, kinetics, etc., time is something that is not all-permeating but rather judged based off of temperature, the motions of particles, etc.

* http://www.time-direction.de/

- Bryan

 

[russ_watters]

I have been searching for the scientific evidence of such physical existence of time but I have foundd none.

...time itself has been never prove as existing by experimental methods.

Have you checked your watch?

Wikipedia appears to recognize that time cannot be defined by physical means...

I'm not sure what you mean by that, but their definition seems reasonably good to me - and directly contradicts your assertion that it can't be measured:

One view [the physics view] is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured [ie, with your watch].

Furthermore:

In physics, time and space are considered fundamental quantities (i.e. they cannot be defined in terms of other quantities because other quantities - such as velocity, force, energy, etc - are already defined in terms of them). Thus the only definition possible is an operational one, in which time is defined by the process of measurement and by the units chosen.

As it says, there is no more difficulty in measuring and/or accepting the reality of time than there is of other physics fundamentals such as length and mass. We get a lot of people here who question the existence of time, but for the above reason, I never understand why they have so much trouble with it.

 

[madness]

The main problem with time in physics is whether time flows, ie whether time is static like a spatial dimension or whether we really move through it like common experience suggests. In Brian Greene's Fabric of the Cosmos he quotes Einstein as saying that time is static and the the perceived flow of time is an illusion caused by our own minds. He says there is no physical basis for believing that time does flow. Spacetime is thought of as a 4-dimensional structure with points corresponding to each event, where time is one of the axes.

 

[ice109]

We get a lot of people here who question the existence of time, but for the above reason, I never understand why they have so much trouble with it.

because a lot of physical "laws" are time independant, in that they work the same backwards and forwards "in time".

 

[rbj]

We get a lot of people here who question the existence of time, but for the above reason, I never understand why they have so much trouble with it.

i nearly completely agree with you, Russ, particularly for someone doing "operational" physics as opposed to existential and metaphysical philosophy. we know it's there (or something is there, that we detect with our own consciousness, and measure with clocks), we don't know precisely what it is (just as we don't know precisely what space is or what reality really is), but, at least for us operational or rational or empirical folks, we sort of skip over that issue and start describing it and how it is related empirically to the rest of reality that we observe. we observe some coupling of motion in space to time, that this coupling is linear for inertial movement, and we observe this arrow of time that, so far, has not been shown to be violated outside of the mystery of black holes, as far as i know. this arrow of time has, i believe, no counterpart to the 3 spatial dimensions, and for that reason is sufficient to differentiate it qualitatively from space (which is a belief challenged by relativity, depicting time as the same kinda "stuff" that space is but with mathematical values that are imaginary numbers, but not sufficiently challenged for my money).

as human beings, our concept of time was shaken up a little by Einstein in such a way that its alledged absolute, universal, and eternal nature is challenged. for people or objects in frames of reference that are not stationary relative to each other, neither is their perception or observation of time identical.

if it is true that time itself had no existence "before" the big bang, it could also be true that if there would ever be a "big crunch" (i am not saying that such would ever happen), that time itself would have no existence "following" the big crunch.

but we don't know exactly what time is just as we don't know exactly what reality is, although most of us accept the existence of both. and then, once we get past that, the only thing that an empiricist can do is, from observation, try to discern relationships between this thing we measure with clocks to any other physical phenomena. we have such relationships (of "stuff" vs. time) in Newtonian physics, Einsteinian physics, "Schrödingerian physics" (a.k.a. Quantum Mechanics, there is a time-dependant version of Schrödinger's equation, even though it wasn't used much when i was learning some of this stuff in college), and i s'pose in any TOE or GUT or cosmology (although what they say about time is far beyond my pay grade, being an engineer).

Newtonian physics had no intrinsic natural coupling factor between this thing we call "time" and anything else. well, i guess it does in the same way that General Relativity does with the Gravitational constant, G:

t = \frac{1}{\sqrt{G}} \cdot \sqrt{ \frac{d^3}{m} }

where d is distance (or length, the measure of "stuff" in one spatial dimension), d^3 would be volume, and m is mass.

Special and General Relativity ("Einsteinian physics") intrisically or naturally couples time to distance by use of a scaling factor we commonly called the speed of light, c:

t = \frac{1}{c} \cdot d

And Quantum Mechanics (or "Wave Mechanics" or what I've been calling "Schrödingerian physics") intrinsically naturally couples time to energy by use of a scaling factor we commonly called Planck's Constant, \hbar:

t = \hbar \cdot \frac{1}{E}

but we already have a relationship that defines the stuff called "energy" in terms of stuff we call time, mass, and distance, (E = F \cdot d = (m d/t^2) \cdot d) which turns the scaling factor around so that, more fundamentally:

t =\frac{1}{\hbar} \cdot d^2 m

Now all of these scaling factors, 1/G, 1/c, 1/\hbar are there only because of the (most commonly) anthropocentric (or, more precisely, "anthropometric") units we came up with as a consequence of the clocks, (meter) sticks, and weighing scales we use. We can (and do, with "Planck Units") make these all go away from our known laws of physics (which are really just mathematical expressions of what we observe). For instance, with relativily (special or general), when we choose units so to set c=1, does that mean that time and distance are the same thing (time, expressed as a spatial dimension, picks up a dimensionless mathematical constant factor of the imaginary unit, i, so "time" would be "imaginary distance" i s'pose)? But if you look at the other two relationships (with natural units), is time the same thing as area times mass? or the square root of volume divided by mass? i don't think so (i could manipulate those relationships above to show that time is the same as its reciprocal and same for all other fundamental quantities), but there are physicists who think that there really is no dimensional difference between that stuff.

sorry, if i am creating more questions than answers, but maybe the answer to the OP's question is "we don't exactly know".

 

[incandescent]

The only truism I can come up with is that it must be something, since we experience it.

I believe that this is a precept of most philosophies; that human experience has some basis in 'real' 'reality', even if it isn't the most direct representation.

Can anyone with experience in GUTs tell me whether there are any that consider time to be an otherwise identical dimension, or is it fundamentally different to the spatial dimensions in all theories?

Thank you very much for your reply.

I have thought about your words and I asked myself, how do we "experience it?"

I checked the philosophical thoughts and most of them appear to direct a time which flows, but scientifically such event is not validate by any experiment made exclusively for it. Other philosophical thoughts say that "we are time", something which also won't guide us scientifically to any place.

I guess that philosophical thoughts about time must be discarded because these cannot be verified through the scientific method.

 

[incandescent]

lol, are you searching for the ether of time? space and time are dimensions, information needed in order to specify location in our universe... time does not flow or change, you move through time, just as you move through space, the main difference is that you have some default motion through time but not through space, you can't however move through space without affecting time. When one says... time dilates, all that means is that they are moving slower through time (thus time passes slower) because they are moving faster through space. There's sort of an equilibrium between space and time. We are at one end were we move full speed through time and stand still spatially, and at the other the photon who moves at full speed through space and thus does not move through time. There is nothing mystical here, but this is a cool quote... "time is nature's way of keeping everything from happening at once" The fact that things change can be your physical proof of time.

Your reply is most than interesting. Please allow me to consider time as a dimension, this is to say that time can be understood with coordinates.

I make 23 lines with the same intervals on my desk Earth globe from pole to pole and I called them Longitudes or Hours. Having you correct, I guess that time is what you say, a dimension with coordinates.

Now well, that is what we humans draw in an Earth globe, but in physical reality our planet doesn't have such lines. I guess again that for this reason several books point that such are imaginary lines.

Still, I can perceive space between the drawn longitudes in my easrth globe and between my physical location in reference with other locations. I perceive that betwen my person and Japan there is a separation. There is no doubt that there is a space between you and planet Mars and between the White House and the Crab Nebula.

I can't, however, say the same about time, because according to you, time is a dimension only.

As far as I can check your point, I can obtain the other three dimensions from a physically existing space, and I know it exists because I can perceive it like everybody. Because everybody can perceive it with their senses as I do, this is considered as physically existent.

I don't know if we can do the same with time. I have no idea that there is a sense or a device which will allow us to perceive the flowing of time.

 

[incandescent]

Although there is a mathematical basis to "dimensions," we really do not have evidence that time is a dimension. In statistical thermodynamics, kinetics, etc., time is something that is not all-permeating but rather judged based off of temperature, the motions of particles, etc.

* http://www.time-direction.de/

- Bryan

I guess that your point is very different, I can think of it like if time is no more than a measurement.

Having time as a mesurement and not as a dimension, we cannot measure time but that we can use the units given to this measurement to measure the motion of things.

 

[incandescent]

Have you checked your watch?

Yes, I did it. I did something more than checking my watch, I opened it.

I don't see any particular sensor inside my watch which will allow me to measure the physical passage of time. I guess that I better open an old mechanical watch which is more easy to identify its parts.

I have a pictorial dicctionary, I'm lucky. Let me see. I see the parts of the watch but no sensors to verify that time is flowing in a standard way. Sorry, I guess that a watch cannot measure any passage of time.

I'm not sure what you mean by that, but their definition seems reasonably good to me - and directly contradicts your assertion that it can't be measured: Furthermore: As it says, there is no more difficulty in measuring and/or accepting the reality of time than there is of other physics fundamentals such as length and mass.

Ok, please check in Wikipedia how the physical flowing of time is measured. If you find it, I'll hope you also post it here. What I understand is that they can define time as many ways is possible but not so under any experimental data.

Maybe my words can be understood with the following example:

I perceive space. For this purpose, I say that there is space between me and a wall over there. I extend my arms and I cannot reach the wall. I must walk in order to reach it, so, I have experimentally proved the existence of space. I can use several methods and all of them will prove the same. Then, I measure the separation between me and the wall and called it distance. Distance is not physically existing, the word distance exist as a reference, it it is a concept. On the other hand, what is physically existent is space.

I think that the autor(s) in Wikipedia cannot show similar experiments about a flowing time. This appears to be a difficulty for the article.

We get a lot of people here who question the existence of time, but for the above reason, I never understand why they have so much trouble with it.

Perhaps is because the question is not answered yet with the proper scientific support.

 

[xez]

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

"Time flies like an arrow, fruit flies like a banana."

"Time, time, time
See what's become of me...
Time, time, time
See what's become of me
While I looked around
For my possibilities
I was so hard to please
Look around
Leaves are brown
And the sky
Is a Hazy Shade of Winter..."

 

[russ_watters]

Yes, I did it. I did something more than checking my watch, I opened it.

I don't see any particular sensor inside my watch which will allow me to measure the physical passage of time. I guess that I better open an old mechanical watch which is more easy to identify its parts.

I have a pictorial dicctionary, I'm lucky. Let me see. I see the parts of the watch but no sensors to verify that time is flowing in a standard way. Sorry, I guess that a watch cannot measure any passage of time.

Lol, check again - it's on the outside of the watch!

Ok, please check in Wikipedia how the physical flowing of time is measured.

If you find it, I'll hope you also post it here. What I understand is that they can define time as many ways is possible but not so under any experimental data.

Look at your wach. (read aloud the number the second hand is pointing to)






Now look at your watch again.

You've just measured the physical flow of time.

I think that the autor(s) in Wikipedia cannot show similar experiments about a flowing time. This appears to be a difficulty for the article.

Perhaps is because the question is not answered yet with the proper scientific support.

You agreed with wik before when you thought it supported your point - you cited it, not me. Perhaps the problem isn't with wik or with the scientific supoprt for the existence of time. Perhaps if you drop your preconceptions and actually try to understand what time is, you will.

 

[russ_watters]

Still, I can perceive space between the drawn longitudes in my easrth globe and between my physical location in reference with other locations. I perceive that betwen my person and Japan there is a separation. There is no doubt that there is a space between you and planet Mars and between the White House and the Crab Nebula.

I can't, however, say the same about time, because according to you, time is a dimension only.

Why are you picking on time? You can't see mass in the way you can see length either, but yet you do not have the same incredulity about its existence, do you?

Time is different from length. You don't measure it in the same way and you can't see it with your eyes in the same way. But you can still measure it and perceive it with the proper tools. Just like mass. So why the problem with time?

 

[incandescent]

if it is true that time itself had no existence "before" the big bang, it could also be true that if there would ever be a "big crunch" (i am not saying that such would ever happen), that time itself would have no existence "following" the big crunch.

I agree with you, "if" it is true. What happens "if" it is not true? Any alternative from your part?

but we don't know exactly what time is just as we don't know exactly what reality is,

I ask for your forgiveness because I cut off your whole paragraph , but it was necessary.

Scientifically we know what reality is: in science Reality is what exist physically. check Wikipedia:

Reality, in everyday usage, means "the state of things as they actually exist."

We do know what reality is. As long we perceive it, it is real. You perceive the image and the breeze when you are standing in the sand near the ocean, and also you perceive a rotten lotion which smells like ocean's breeze and you have a picture in a wall showing you the sand and the ocean.

As long as you perceive them and they can be perceived by others as well, what you perceive is physically existent.

Now, you imagined both, the breeze and the image, the imaginations still real but in your mind alone. As your imaginations cannot be measured or perceived by others, your imaginations are not accepted as part of science (physics) to validate a theory, to analyze them as a phenomenon and more.

but we don't know exactly what time is just as we don't know exactly what reality is, although most of us accept the existence of both. and then, once we get past that, the only thing that an empiricist can do is, from observation, try to discern relationships between this thing we measure with clocks to any other physical phenomena. we have such relationships (of "stuff" vs. time) in Newtonian physics, Einsteinian physics, "Schrödingerian physics" (a.k.a. Quantum Mechanics, there is a time-dependant version of Schrödinger's equation, even though it wasn't used much when i was learning some of this stuff in college), and i s'pose in any TOE or GUT or cosmology (although what they say about time is far beyond my pay grade, being an engineer).

I must disagree with what you just say. With all my respect, why you seem to jump to conclusions when right in the beginning your points appear to be full of gaps?

Example: "we don't know exactly what reality is, although most of us accept the existence of both. and then, once we get past that,..."

Wait please, do not run because you can fall.

Take it easy. You don't know what reality is but you accept consciouness detections as real things, and with such base you just got pass that.

I don't see any reason why I can trust what you just said.

If I accept your words as the answer to define and prove the existence of time, I practically have nothing to verify what I received from you.

I cannot read your mind, I myself do not detect with my consciousness any physical passage of time, and neither I can find any device which can detect it either.

I am disappointed with myself, I should like to detect the passage of time with my consciousness as well as you do. Even so, right after that, I should like to prove such detection with a device so I can finally accept its physical existence with a scientific validation.

 

[madness]

The question is whether or not there is a present moment that is moving forward through time. What is physically different about the present moment from other moments? Do all moments in time simply exist as points on a line or do we flow along the line with only one moment existing at a time? According to both Brian Greene and Paul Davies (and apparently Einstein) there is no such thing as the present moment and time does not flow. Time is static.

 

[OmNihilo]

What's all this blabbering about time? Time is not a physical object. You can't affect it. (I didn't feel like reading all the posts, so here's my 2 cents)

Before the universe, "time" had always existed and never changed. It doesn't change; it can't change. Time is a constant. If "time" were to freeze, the universe would cease to exist. We only concern ourselves with time because matter is finite, and we must measure how long it has existed with something. Time is far from finite, therefore, you can't affect it. It's like trying to reduce the amount of numbers in existence. You can't.

Don't go looking for time with "experiments", because all you are going to find is matter, space and energy. Time, by defintion is an object which is impossible to "detect".

Time is the measurement of the progression of events. It is not anything like jelly or hydrogen (immaterial). It does not cease to exist apart from matter, but it only has a use with matter, being the subject of cause and effect.

Time does not intersect with space. It is a constant, and by definition unaffectable by anything else.

 

[incandescent]

Why are you picking on time? You can't see mass in the way you can see length either, but yet you do not have the same incredulity about its existence, do you?

Time is different from length. You don't measure it in the same way and you can't see it with your eyes in the same way. But you can still measure it and perceive it with the proper tools. Just like mass. So why the problem with time?

Yes I can't see mass because mass is a measurement of matter and is considered as a concept in physics.

I can't see length itself bbecause is another concept but I can apply this concept in physics and see your lenght, the length of an airplane, and more.

Concepts as lenght, width and depth are given to the structure of things in the universe by their physical appearance. You can see their appearance, and we live in a three perceptable dimensional universe. Don't you think?

When someone says to me, "look, if you take a point which has one dimension", I immediately disagree with that idea as a fact.

Actually there is not such thing as one or two dimensional worlds, we use those concepts to make our studies more easy to understand, but when I draw a point in a piece of paper and I use a magnified glass or a microscope I will notice that the paper itself is three dimensional and that the point in the piece of paper is also three dimensional as well. It is understood, however, that used as a reference in a study I can consider the point as one dimensional object, and the drawing in the paper as representing a two dimensional picture or image.

You say that we can measure and perceive time with the proper tools, I have been loking for those tools and find none. I will please ask you to name those tools.

 

[cristo]

When someone says to me, "look, if you take a point which has one dimension", I immediately disagree with that idea as a fact.

As would I: points have no dimensions.

You say that we can measure and perceive time with the proper tools, I have been loking for those tools and find none. I will please ask you to name those tools.

Huh What's wrong with a watch?

 

[incandescent]

The question is whether or not there is a present moment that is moving forward through time. What is physically different about the present moment from other moments? Do all moments in time simply exist as points on a line or do we flow along the line with only one moment existing at a time? According to both Brian Greene and Paul Davies (and apparently Einstein) there is no such thing as the present moment and time does not flow. Time is static.

So, when we walk from one place to another we are drawing dots in space which will be printed as pictures, is this the first idea?

About a static time, I guess that in a physical universe where the ruler is motion, such idea cannot be considered physically real.

 

[incandescent]

What's all this blabbering about time? Time is not a physical object. You can't affect it. (I didn't feel like reading all the posts, so here's my 2 cents)

Before the universe, "time" had always existed and never changed. It doesn't change; it can't change. Time is a constant. If "time" were to freeze, the universe would cease to exist. We only concern ourselves with time because matter is finite, and we must measure how long it has existed with something. Time is far from finite, therefore, you can't affect it. It's like trying to reduce the amount of numbers in existence. You can't.

Don't go looking for time with "experiments", because all you are going to find is matter, space and energy. Time, by defintion is an object which is impossible to "detect".

Time is the measurement of the progression of events. It is not anything like jelly or hydrogen (immaterial). It does not cease to exist apart from matter, but it only has a use with matter, being the subject of cause and effect.

Time does not intersect with space. It is a constant, and by definition unaffectable by anything else.

When you say, Time, by defintion is an object which is impossible to "detect". I wonder, when you can't detect it, how you can state that is an object?

I am tempted to the assumption to state about what I understand from your words that what you might mean is that time is a measurement and for this reason we won't detect it as physically existent. I'll hope I understood you correctly.

 

[incandescent]

As would I: points have no dimensions.


Huh What's wrong with a watch?

Well, let's see what I understand about a watch.

I live in a point of Earth which is in the Equator line. Well, I don't live there in reality but I will use this location in my example.

I noticed that I can see the Sun right over me and at certain point no shadow is noticeable under me.

Well. I fill up a big tank of water and make a tiny hole in its bottom. I will put a cap on it. I will wait until the image of the Sun is over me so no shadows are seen under me again. In this particular point, I will take the cap out and water will start to drip.

I will count the drops of water falling from the tank until the next event when the image of the Sun is again over me and no shadows are perceived under me.

I have counted 86,400 drops of water between the intervals.

I will name these physically perceptable events. To the interval between the events and the Sun light didn't cause a shadow under me I will call it a day.

I want to have a measurement to check how long it will take for me to eat my breakfast everyday. So, as I know that a day is equal to 86,400 drops of water dripping from my tank, I will name to each drop as a second.

But, for me is very uncomfortable to be recording big amount of numbers, so I will divide these amount of 86,400 into 60, and I will have the quantity of 1,440, and to each one of these new groups I will call it a minute.

Still it is very hard to keep a track with thousands here and there, so I will divide the amount of this new groups called minutes into 60 again, and I have the quantity of 24. To these new groups I will call them hours.

Well, I have 24 hours, or 1,440 minutes, or 86,400 seconds, which is what I have named after I check how many drops of my tank are needed to be compared with intervals with no perception of shadows under me.

I called a friend of mine who is very good making mechanical devices and he as well imitated the intervals of a day, an hour, a minute and a second in a round device with needles pointing 12 numbers, and he called it a clock. He explained me that by dividing the desired data of a day in half, I will make another division to use the clock, the first 12 hours will be called A.M., with the meaning of ante-meridiem, and the next period of 12 hours will be called P.M. with the meaning of post-meridiem.

So far, I don't see from any point of view that a clock can measure the pasage of time.

What it appears to me, is that I started to call a day to the interval between the no shadow events under me, and that I have created a new concept used now as a measurement called time.

Actually I didn't perceive any physical time, what I have perceived is motion of things around, like the Sun and the drops of water. I have compared the motion of both events and I have created a clock to keep a more accurate data of the motion of things and their locations or decay.

As far as I know, this is how the clock was invented, in base of a comparison of motion of things.

Do I miss something here? If so, please point the error.

 

[cristo]

What actually is your point? Are you arguing that time doesn't exist? How, then, do you explain causality, or the fact that things do not all happen at the same instance?

Your argument about "inventing" days could very easily be transferred to distance. What is distance? The measure between two points in a (or 3) spatial dimensions. The change in time is therefore a measure between two points in a temporal dimension.

I really don't see the problem that you are having here.

 

[ranger]

Well, let's see what I understand about a watch.

I live in a point of Earth which is in the Equator line. Well, I don't live there in reality but I will use this location in my example.

I noticed that I can see the Sun right over me and at certain point no shadow is noticeable under me.

Well. I fill up a big tank of water and make a tiny hole in its bottom. I will put a cap on it. I will wait until the image of the Sun is over me so no shadows are seen under me again. In this particular point, I will take the cap out and water will start to drip.

I will count the drops of water falling from the tank until the next event when the image of the Sun is again over me and no shadows are perceived under me.

I have counted 8,6400 drops of water between the intervals.

I will name these physically perceptable events. To the interval between the events when the Sun light didn't cause a shadow under me I will call it a day.

I want to have a measurement to check how long it will take for me to eat my breakfast everyday. So, as I know that a day is equal to 86,400 drops of water dripping from my tank, I will name to each drop as a second.

But, for me is very uncomfortable to be recording big amount of numbers, so I will divide these amount of 86,400 into 60, and I will have the quantity of 1,440, and to each one of these new groups I will call it a minute.

Still it is very hard to keep a track with thousands here and there, so I will divide the amount of this new groups called minutes into 60 again, and I have the quantity of 24. To these new groups I will call them hours.

Well, I have 24 hours, or 1,440 minutes, or 86,400 seconds, which is what I have named after I check how many drops of my tank are needed to be compared with intervals with no perception of shadows under me.

I called my friend of mine who is very good making mechanical devices and he as well, imitated the intervals of a day, an hour, a minute and a second in a round device with needles pointing 12 numbers, and he called it a clock. He explained me that by dividing the desired data in half, I will make another division to use the clock, the first 12 hours will be called A.M., with the meaning of ante-meridiem, and P.M. with the meaning od post-meridiem.

So far, I don't see from any point of view that a clock can measure the pasage of time.

What it appears to me, is that I started to call a day to the interval between the no shadow events under me, and that I have created a new concept used now as a measurement called time.

Actually I didn't perceive any physical time, what I have perceived is motion of things around, like the Sun and the drops of water. I have compared the motion of both events and I have created a clock to keep a more accurate data of the motion of things and their locations or decay.

As far as I know, this is how the clock was invented, in base of a comparison of motion of things.

Do I miss something here? If so, please point the error.

And your point is... Time doesn't exist?

 

[rbj]

I agree with you, "if" it is true. What happens "if" it is not true? Any alternative from your part?

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".)

I ask for your forgiveness because I cut off your whole paragraph , but it was necessary.

Scientifically we know what reality is: in science Reality is what exist physically. check Wikipedia:

Reality, in everyday usage, means "the state of things as they actually exist."

We do know what reality is. As long we perceive it, it is real.

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).

You perceive the image and the breeze when you are standing in the sand near the ocean, and also you perceive a rotten lotion which smells like ocean's breeze and you have a picture in a wall showing you the sand and the ocean.

As long as you perceive them and they can be perceived by others as well, what you perceive is physically existent.

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?"

Now, you imagined both, the breeze and the image, the imaginations still real but in your mind alone. As your imaginations cannot be measured or perceived by others,

other people can watch the same pendulum swing or, on a caesium clock, the same counter increment.

I must disagree with what you just say. With all my respect, why you seem to jump to conclusions when right in the beginning your points appear to be full of gaps?

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.

Example: "we don't know exactly what reality is, although most of us accept the existence of both. and then, once we get past that,..."

Wait please, do not run because you can fall.

dunno what you mean.

Take it easy. You don't know what reality is but you accept consciouness detections as real things, and with such base you just got pass that.

I don't see any reason why I can trust what you just said.

If I accept your words as the answer to define and prove the existence of time,

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.

I practically have nothing to verify what I received from you.

I cannot read your mind, I myself do not detect with my consciousness any physical passage of time,

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.

and neither I can find any device which can detect it either.

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

I am disappointed with myself, I should like to detect the passage of time with my consciousness as well as you do. Even so, right after that, I should like to prove such detection with a device so I can finally accept its physical existence with a scientific validation.

dunno what to do with this one.

 

[incandescent]

What actually is your point? Are you arguing that time doesn't exist? How, then, do you explain causality, or the fact that things do not all happen at the same instance?

Your argument about "inventing" days could very easily be transferred to distance. What is distance? The measure between two points in a (or 3) spatial dimensions. The change in time is therefore a measure between two points in a temporal dimension.

I really don't see the problem that you are having here.

I am looking for the experimental evidence that time exists physically.

Causality can be explained without time: You have a particle in motion, in its way this particle will cause some effects with other particles around, and so and so. You have a physical and observable particle, you have a physical and observable medium which is called space.

Time it appears to be like distance as you just compared it, but still it is not a perceptable thing or energy or something physical.

My question is that having that time has not been proved as physically existing, how it comes that it can dilate by the speed of objects or the gravity of bodies?

Now well, you are pointing again that time is a measurement only, because you said that The change in time is therefore a measure between two points in a temporal dimension.

I guess that you agree until now in this dialogue that time is a measurement. I guess this is already understood by others as well. How a measurement will dilate by the changes caused by bodies is the next point.

 

[incandescent]

And your point is... Time doesn't exist?

This is the answer I am looking for this question: What is time?.

This is a forum of physics and I thought you may have an answer with its correspondent scientific back up.

 

[meopemuk]

I am looking for the experimental evidence that time exists physically.

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

... how it comes that it can dilate by the speed of objects or the gravity of bodies?

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

 

[Gokul43201]

Wikipedia appears to recognize that time cannot be defined by physical means, and this bothers me a lot.

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.

 

[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