# What do our clocks read?

## Summary:

It is said that when asked- “what is ‘time’?”- Einstein once replied, “Time is what our clocks read”. But what do our clocks read? One may easily reply to this question- our clocks read ‘Time’. But isn’t it a circular argument?I have tried to find an answer.

## Main Question or Discussion Point

What Do Our Clocks Read?

It is said that when asked- “what is ‘time’?”- Einstein once replied, “Time is what our clocks read”. But what do our clocks read? One may easily reply to this question- our clocks read ‘Time’. But isn’t it a circular argument? We can understand it by an analogy. If someone asks you- “what is length?”, would your answer be “Length is what a measuring tape reads”? And if he asks back, “What does a measuring tape read?”; would you reply again- “A measuring tape reads length”? Definitely this will not be a genuine answer. It will be a circular answer. A specific answer to this question might be; “Length is one of the spatial extensions of an object”.

Similarly, the question- “What is time?” too needs a more specific answer.

I have tried to reach the answer through the above analogy itself. Let us ask the question, “What does a measuring tape read?” Is there any invisible length in the sky that it measures? Does it make any sense if we say that it is measuring an invisible spatial dimension of space? I think these answers hardly make a good sense. In my view, a more sensible answer will be that a measuring tape first of all reads its own length- its longest spatial extension. It tells that it is a meter long. It also tells that a meter- a man-made unit of length- is this much long. Then, by comparison, it measures the lengths of other objects too. After all, a measuring tape is just like any other object, any other tape; the only difference is that it is graduated, or marked (according to a man-made standard) to read its spatial extension.

Similar explanation can be given for a clock. A clock too is like any other object that gets old every moment- that is, extends in its fourth dimension. Other objects too get old every moment but are generally not marked to measure their extension into their fourth dimension (though there are many that have such markings, like a developing embryo or a beating heart, albeit not very precise). A clock has been marked (according to some man-made standard) to measure and read its extension into its fourth dimension. It seems that, like a measuring tape, it too does not measure any invisible fourth dimension of space, any invisible time. Rather, it measures its extension into its own fourth dimension (its aging). In a simpler term, a clock measures and reads its own aging. Then, by comparison, it reads the aging of other objects.

Now suppose, there is a growing tree, increasing in height (say length) by a meter every year. Is its length (the spatial dimension) responsible for its growth? Or its growth is responsible for its length? Certainly, the latter statement is true, not the former. The tree’s growth is responsible for its length (a spatial dimension). The spatial dimension of the tree is thus not the cause but the effect. It is not a requirement but an acquirement.

Now we see that, along with its length, the tree is also gaining ‘age’. Similar question can be asked for its age too. Is age (the fourth dimension) of the tree responsible for its growth? Or its growth is responsible for its age? Naturally, its growth is responsible for its age. Thus, age, or the fourth dimension too is not the cause but the effect. Fourth dimension (say, time) is, therefore, not a requirement for aging, but is an acquirement for aging. Time seems to be the fourth dimension of objects, a measurement of their aging. A clock measures its own aging.

## Answers and Replies

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fresh_42
Mentor
You have basically two possibilities with that question: either dive into philosophy - deeply, or take it as it is - a clock is a machine which counts. That's all in my opinion. A clock counts. Ancient roman clocks counted water drops, modern atomic clocks count frequency. With the next question, why counting takes time, we are already in the middle of philosophy, a terrain on which your question cannot be answered satisfactory here.

PeroK
Science Advisor
Homework Helper
Gold Member
The critical thing for time to make sense is that certain natural processes remain synchronised.

There is a fixed relationship between years (orbit of the Earth), cycles of the moon, days (revolutions of the Earth) etc.

If you then design an hour glass that empties 24 times the first day you find it always takes 24 times every day. And so on.

This is what creates the concept of time. You then separate natural processes into those that are synchronised and those that are not. Those that remain synchronised are candidates on which to base the design of a clock.

You have basically two possibilities with that question: either dive into philosophy - deeply, or take it as it is - a clock is a machine which counts. That's all in my opinion. A clock counts. Ancient roman clocks counted water drops, modern atomic clocks count frequency. With the next question, why counting takes time, we are already in the middle of philosophy, a terrain on which your question cannot be answered satisfactory here.
Thanks

The critical thing for time to make sense is that certain natural processes remain synchronised.

There is a fixed relationship between years (orbit of the Earth), cycles of the moon, days (revolutions of the Earth) etc.

If you then design an hour glass that empties 24 times the first day you find it always takes 24 times every day. And so on.

This is what creates the concept of time. You then separate natural processes into those that are synchronised and those that are not. Those that remain synchronised are candidates on which to base the design of a clock.
thanks

Dale
Mentor
Summary:: It is said that when asked- “what is ‘time’?”- Einstein once replied, “Time is what our clocks read”. But what do our clocks read? One may easily reply to this question- our clocks read ‘Time’. But isn’t it a circular argument?
If A=B then B=A. That is not circularity, it is the symmetric property of equality. The problem isn’t the answer, the problem is the question. No amount of fiddling with the answer can fix a bad question.

The question is bad because the answer is already provided and is obvious. It relies on the answerer’s kindness to not tell the questioner that they are asking a bad question. There is no learning value to the question and it serves only entertainment value in watching the answerer struggle with the purely social challenge of not insulting the questioner, I.e. watching the answerer figure out how to point out the stupidity of the question without in any way implying that the questioner is stupid.

Not all questions are good, and this is one example of a bad question. The questioner should be told so, and helped to understand why. There are two possibilities: either the questioner knows the question is bad, or they do not. If they do not know then they need to be taught, asking good questions is a difficult skill. If they do know then they should be taught that it is not socially acceptable to prey on a kind answerer’s good disposition for entertainment.

Last edited:
If A=B then B=A. That is not circularity, it is the symmetric property of equality. The problem isn’t the answer, the problem is the question. No amount of fiddling with the answer can fix a bad question.

The question is bad because the answer is already provided and is obvious. It relies on the answerer’s kindness to not tell the questioner that they are asking a bad question. There is no learning value to the question and it serves only entertainment value in watching the answerer struggle with the purely social challenge of not insulting the questioner, I.e. watching the answerer figure out how to point out the stupidity of the question without in any way implying that the questioner is stupid.

Not all questions are good, and this is one example of a bad question. The questioner should be told so, and helped to understand why. There are two possibilities: either the questioner knows the question is bad, or they do not. If they do not know then they need to be taught, asking good questions is a difficult skill. If they do know then they should be taught that it is not socially acceptable to prey on a kind answerer’s good disposition for entertainment.
Great. Thanks for such an educating answer.

Does time exist?

PeroK
Science Advisor
Homework Helper
Gold Member
Does time exist?
From a physics perspective why wouldn't it? It's a measurable quantity.

Does time exist?
In my view, time does exist; in the manner length, width and height exist. Length, width and height are not things but properties of objects. Time too is a property of objects. Length, width and height are the three spatial dimensions of objects; time is the fourth. Defining time as the fourth dimension of space ( intermingled with the rest three) creates an illusion of its being a thing, at least for a common man. Defining it as the fourth dimension of objects removes all illusions from its face, without interfering with physical laws.
Does time exist?

Vanadium 50
Staff Emeritus
Science Advisor
Education Advisor
2019 Award
So the point in your asking the question was just so you could tell us your own, unorthodox view?

Dale
Mentor
Length, width and height are not things but properties of objects. Time too is a property of objects.
You are confusing “time” with “lifetime”. An object has length, width, height, and lifetime.

Mister T
Science Advisor
Gold Member
If A=B then B=A. That is not circularity, it is the symmetric property of equality.
Right. But $A \equiv B$ and $B \equiv A$ is circular.

Mister T
Science Advisor
Gold Member
Summary:: It is said that when asked- “what is ‘time’?”- Einstein once replied, “Time is what our clocks read”. But what do our clocks read? One may easily reply to this question- our clocks read ‘Time’. But isn’t it a circular argument?
Yes, it is circular reasoning. But any body of knowledge must necessarily contain primitives that can't be defined. Imagine you and your friends have managed to create a new language that you can use to communicate with each other so that the communications are not understood by others and in that sense are kept private. You decide to create a dictionary of this new language. But how shall you define the first term? You would necessarily have to define it in terms of other words that you haven't yet defined.

In Post #3 @PeroK outlines what we need for the concept of time to be useful in physics.

The other stuff, as @fresh_42 reminds us in Post #2, is philosophy.

Dale
Mentor
Right. But $A \equiv B$ and $B \equiv A$ is circular.
But that is not what is going here. The statement “Time is what our clocks read” could be seen as a definition or a simple equality, but the statement “what our clocks read is time” would not be seen as a definition, only simple equality. My comments above hold here.

Yes, it is circular reasoning.
While there is plenty of circularity in science, this is not the case here in this specific thread.

So the point in your asking the question was just so you could tell us your own, unorthodox view?
No, I do not intend to tell anything. I am no expert in this field. I simply wish to present an alternative view for criticism. Thanks

Yes, it is circular reasoning. But any body of knowledge must necessarily contain primitives that can't be defined. Imagine you and your friends have managed to create a new language that you can use to communicate with each other so that the communications are not understood by others and in that sense are kept private. You decide to create a dictionary of this new language. But how shall you define the first term? You would necessarily have to define it in terms of other words that you haven't yet defined.

In Post #3 @PeroK outlines what we need for the concept of time to be useful in physics.

The other stuff, as @fresh_42 reminds us in Post #2, is philosophy.
OK. Thanks.

You are confusing “time” with “lifetime”. An object has length, width, height, and lifetime.
Thanks. At least, I have been able to convey my 'confusion' to you. I am not confusing 'time' with 'lifetime'. Rather, I wish to present my view that 'lifetime' is itself 'time'. 'Time' is the 'measurement of lifetime' itself. And I want to receive you people's criticism on my view.
With Regards.

You have basically two possibilities with that question: either dive into philosophy - deeply, or take it as it is - a clock is a machine which counts. That's all in my opinion. A clock counts. Ancient roman clocks counted water drops, modern atomic clocks count frequency. With the next question, why counting takes time, we are already in the middle of philosophy, a terrain on which your question cannot be answered satisfactory here.
Should a Geiger Counter be considered a clock??
Perhaps the notion of counting is necessary but not quite sufficient. In particular the clock must count a series of "equivalent" events. The fact that the interval between these equivalent events is somehow universal makes time a useful notion. Perhaps this is a distinction without a difference.....I cannot decide.

Dale
Mentor
I wish to present my view
That is not the purpose of this site. We are explicitly not interested in learning about views that are not consistent with the professional scientific literature.

'Time' is the 'measurement of lifetime' itself. And I want to receive you people's criticism on my view.
First and most important criticism is that this is not the view in the professional scientific literature.

Second criticism is that this probably does lead to a genuine circular reasoning. If "time" is defined as "the measurement of lifetime" then we have to define "lifetime". As far as I know "lifetime" is "the difference in the time between the beginning and the end of an object", which takes us back to the previous definition. While there may be a way out of that circularity, it is not something which has been developed or accepted by mainstream scientists.

Since this thread is now going into personal speculation, we will close it.

fresh_42
Mentor
Should a Geiger Counter be considered a clock??
Yes, it does. We use e.g. in carbon dating. The difference is only in the precision of the clock. Beside this, I only stated that a clock counts, which is true. I did not claim that any counting process leads to a (reasonable) clock.