We may be able do that by converting time duration into a length. For instance, using a cylindrical hourglass, we can convert a time duration into a high of sand.

Well, but this method implies the assumption of the existence of a linear map f:T->X from time into space. Can you prove that this function is linear without comparing any time unit with the previous one?

When I wrote my comment, I suspected that the answer could not be that easy :)

If there is somehow a contraction/dilatation of time between two successive measures then our measuring device may not be able to detect it. However, it seems to me we can say the same about the length.

If consecutive time units were not the same, what would be the consequences for the measure of the speed of light ?

Dear Lehtihet,

From an empiric and subjective view-point you are right. The the hypothesis or assumption of the linearity of the trajectory of a particle with no acceleration works fine. But it is the consequence of Occam's razor criterion. In classical mechanics works fine. Nevertheless, if you measure lengths in nanometers, your are in the kingdom of quantum mechanics, which is of random nature.

In fact you can see a rule as a solid object, but if you zoom sufficiently, it is a swarm of chaotic particles moving in any direction from which only average positions can be known. Average measures are virtual. You can say that the average weight of a population is 75 kg in spite of the weight of no one of its members is 75 kg.

Let's see if the method could provide the answer mayéutico Expected How consedera or sets the time Lord John?

The clock's ticking away here at RG---it's ticking away everywhere I guess :)

>.....If you split a length into inches, then you can compare two of them in order to test whether or not they are equal in length....

Dear all,

A clock translates time into space. In other words, a clock performs a map f: T -> S and it is supposed that this map is linear.

Notice that when you measure time by means of length, frequency, weight or any measurable attribute X different from time, you are defining implicitly a map f from time into X. In addition, you are assuming that the map f is linear.

Accordingly, the problem is reduced to the linearity of the defined map. In other words, the question can be simplified to the following one.

Is it possible to prove the linearity of a map from time into some other magnitude X different from time?

Dear Juan-Esteban,

are you aware that speaking about a linear map assumes much more mathematical structure than the one in question?

Dear Ulrich,

¿Have you understood my abstraction of the question?

It does not matter whether or not it is linear. Any other method is equivalent. You can use a linear scale, a logarithmic one or what you like. Whatever the structure, you are dealing with a map from time to space f: T -> S.

If you do not know the nature of this map, you know nothing about the measure. If you assume a fixed structure, you must prove that your assumption is right. Can you?

Say me how.

Julian Barbour identified the equality of the interval of time, the equality of a second today with a second yesterday as one of the unsolved problem about time.

Dear Juan-Esteban,

since the end of the 19th century physicists agree that observations and observable facts are the stuff to which one should return when one lost orientation in a jungle of mental constructs. The 'nature of this map' belongs to the jungle.

Dear Prof Juan

if some one rigestered time of certain event for certain interval then its motion state is changed lets say with little deacceleration value that he or she couldnt know about ;it is impossible for him or her to realize the difference in time btween the measure of two events after and before changing the kinetic state,but if the observer is having a point like source with his hand or even without it and there isanother obbserver watching him or her the time measured in both cases will be compared with static observer tthat can realize the difference between both measurements. in other words if any one want to realize the differece in time between two measurements it must compare its state of motion with static observer so the linear relationship can be easily achieved using the simple trasformations between time and llength

Dear Sadeem,

How can you know that an observer is static?

Dear prof Juan

You dont need even to know the most important thing is to put a refrence frame that enables he or she to compare his or her motion with , so he or she can know the difference in state of motion according to this refrence or the other observer.

Dear Sadeem,

You use the concept of motion. Motion is a function of time and velocity into space. For instance, x = v t.

¿Is the velocity v constant? To know this question you must compare two time units. Any procedure involving space is defined through a map. The question must be simplified to prove whether or not a map depending on time can be tested in order to know if it satisfies the assumed structure. To this end, it is unavoidable to compare two different time units. That is the question.

Fortunately, modern technology alleviates these problems: The results of measurements of distances and time spans both are numbers, obtained by counting fast and stable oscillations in small technical devices. You may ask: why stable? Where do you know this from? Simple answer: there are so many technical clocks (as the technical devices just mentioned are normally called) of different principles and those celestial clocks, pulsars, that continuously get checked against each other, that any fundamental inconsistencies can't remain undetected.

One may feel that for fundamental epistemological questions it is not legitimate to argue on the basis of advanced technology. Sometimes I feel the same way and than I wonder what theories we would build if all the bodies arround us (us included) would be of a deformable jelly-like consistence and we would permanently be exposed to a strong and intermittently blowing wind. Then we would not form the idea that our inch would be easier to compare to itself than our second.

Dear Juan

ideally if you want to find an absolute stationary observer you wont find it,because the whole universr is in motion. I think the problem can be solved using another observer which its measurement can be used as a correction factor. for the calculation as use in the GPS systems.

Dear all,

Before contributing I recommend to see the paper

https://www.researchgate.net/profile/Amrit_Sorli/

by Amrit Sorly in order to have an accurate view-point.

Thank you so much for the link. The papers are very interesting, particularly the third in the profile overview.