I see nothing of substance in this philosophical discussion of time. But, if something can be physically manipulated and scientifically measured, I wager it exists. Time dilation does just that.

I see nothing of substance in this philosophical discussion of time. — jgill

If you find nothing of substance in this philosophical discussion of time, then maybe you are not interested in philosophical topics? Almost all major philosophers in history of philosophy had something to say about the nature and existence of time from the era of Aristotle or even before that time.

But, if something can be physically manipulated and scientifically measured, I wager it exists. — jgill

I am not sure if being able to measure X, is a proof of the existence of X. Anyhow we are not denying time is real. We are trying to explore on the nature and existence of time.

Time dilation does just that. — jgill

The problem with Time dilation is that it is another hypotheses i.e. possibility if you could fly in the speed of light. Could you fly in the speed of light? Could anyone? Even if you did, the result is not confirmed. It is a hypotheses.

Maybe we measure oscillation. Not time.

So a duration of time like 10 seconds is number of ocsilations .
Each oscillation exists in a physical moment.
They don't exist simultaneously.

10 meters is in fact ...10 meters.

Not the same kind of measurements.

Space and objects co-exist momentarily; they are co-present. However, for us, the present time is shaped by the current virtual time horizons of the past and future.
— Number2018

What do you mean by "the current virtual time horizon"? — Corvus

There is a paradoxical co-existence of time. On one hand, only the present moment truly exists. However, the nature of the present moment differs from that of spatial locations and objects. The moment vanishes as soon as it emerges and cannot be carried into the next one. It is an event that ceases the instant it appears. And it is neither a brief interval between the past and future nor a fleeting absence of being. Thus, the present moment's reality is shaped by a virtual time, existing as neither what is no longer nor what is not yet, but as the difference between past and future.

I honestly think that time is the most difficult philosophical topic of all. It's more difficult than the topics of space, reality, God, and even Being.

Heidegger himself couldn't conclude Being and Time because he didn't have the language to tackle this issue in an adequate way. No one does.

The arrow of time is the most perplexing aspect here. If you move forward in space, you can move backwards. But you can't move backwards in time, you can only go forward, and necessarily so. The more you think about it, the more mind-boggling it gets.

To paraphrase Augustine: if no one asks me what time actually is, I know what it is. If someone asks me what it is, I don't know what to say.

Well said.

There's an interesting essay on Aeon.co, Who Really Won when Bergson and Einstein Debated Time? Evan Thompson.

It concerns a famous debate which occured spontaneously when Henri Bergson attended a public lecture by Einstein, and then gave an improptu talk on his conception of 'experienced' as distinct from 'objective' time. In short, Einstein brushed off Bergson's talk, and public opinion has generally had it that Einstein, who after all probably has the greatest scientific prestige of any 20th c figure, was correct.

Here, Thompson questions that.

We usually imagine time as analogous with space. We imagine it, for example, laid out on a line (like a timeline of events) or a circle (like a sundial ring or a clock face). And when we think of time as the seconds on a clock, we spatialise it as an ordered series of discrete, homogeneous and identical units. This is clock time. But in our daily lives we don’t experience time as a succession of identical units. An hour in the dentist’s chair is very different from an hour over a glass of wine with friends. This is lived time. Lived time is flow and constant change. It is ‘becoming’ rather than ‘being’. When we treat time as a series of uniform, unchanging units, like points on a line or seconds on a clock, we lose the sense of change and growth that defines real life; we lose the irreversible flow of becoming, which Bergson called ‘duration’.

Think of a melody. Each note has its own distinct individuality while blending with the other notes and silences that come before and after. As we listen, past notes linger in the present ones, and (especially if we’ve heard the song before) future notes may already seem to sound in the ones we’re hearing now. Music is not just a series of discrete notes. We experience it as something inherently durational.

Bergson insisted that duration proper cannot be measured. To measure something – such as volume, length, pressure, weight, speed or temperature – we need to stipulate the unit of measurement in terms of a standard. For example, the standard metre was once stipulated to be the length of a particular 100-centimetre-long platinum bar kept in Paris. It is now defined by an atomic clock measuring the length of a path of light travelling in a vacuum over an extremely short time interval. In both cases, the standard metre is a measurement of length that itself has a length. The standard unit exemplifies the property it measures.

In Time and Free Will, Bergson argued that this procedure would not work for duration. For duration to be measured by a clock, the clock itself must have duration. It must exemplify the property it is supposed to measure. To examine the measurements involved in clock time, Bergson considers an oscillating pendulum, moving back and forth. At each moment, the pendulum occupies a different position in space, like the points on a line or the moving hands on a clockface. In the case of a clock, the current state – the current time – is what we call ‘now’. Each successive ‘now’ of the clock contains nothing of the past because each moment, each unit, is separate and distinct. But this is not how we experience time. Instead, we hold these separate moments together in our memory. We unify them. A physical clock measures a succession of moments, but only experiencing duration allows us to recognise these seemingly separate moments as a succession. Clocks don’t measure time; we do. — Aeon.co

I think this is the salient point: that time itself relies on or is bound to the awareness of duration. And the awareness of duration is something that only a mind can bring. Of course, we don't notice that, because to do so would require becoming aware of awareness, which we cannot do as it would require a perspective outside of awareness. In Kantian terms, the awareness of time is a transcendental condition of experience, and whilst such conditions determine experience, they are not directly available within experience (that being pretty much the meaning of 'transcendental' in Kant's philosophy.)

Thompson goes on to note that Bergson was factually incorrect in his dismissal of the idea of time dilation, which is the discovery that time passes at measurably different rates for observers travelling at vastly different velocities. This error also undermined Bergson's reputation, which overall did not much outlast WWII except for in the Universities, unlike Einstein's, whose reputation has overall only increased. Nevertheless, Thompson argues, Bergson's fundamental insight about the significanc of 'lived time' remains valid, in Thompson's argument.

I honestly don't know what to say. It's a fascinating topic. Evidently there's such a thing as lived time. Otherwise, solitary confinement wouldn't be so unfathomably soul-crushing in modern jails. It's definitely one of the worst forms of punishment. If I were given the admittedly heinous choice between being physically tortured for one minute, or spending a month in solitary confinement doing nothing, I think I might choose the former.

, ok, so going back to the OP, lived time exists?

I think it does. Even though I don't have a sixth sense that allows me to obtain sensory information about time, in the manner that my eyes allow be to obtain visual information, there is "something" like an experience of time. Maybe it's a brain thing, I don't know.

For sure. Emphasis on 'lived'. But that is not what the OP said, and I believe it's overall mistaken.

The problem of including the observer in our description of physical reality arises most insistently when it comes to the subject of quantum cosmology - the application of quantum mechanics to the universe as a whole - because, by definition, 'the universe' must include any observers.

Andrei Linde has given a deep reason for why observers enter into quantum cosmology in a fundamental way. It has to do with the nature of time. The passage of time is not absolute; it always involves a change of one physical system relative to another, for example, how many times the hands of the clock go around relative to the rotation of the Earth. When it comes to the Universe as a whole, time looses its meaning, for there is nothing else relative to which the universe may be said to change. This 'vanishing' of time for the entire universe becomes very explicit in quantum cosmology, where the time variable simply drops out of the quantum description. It may readily be restored by considering the Universe to be separated into two subsystems: an observer with a clock, and the rest of the Universe.

So the observer plays an absolutely crucial role in this respect. Linde expresses it graphically: 'thus we see that without introducing an observer, we have a dead universe, which does not evolve in time', and, 'we are together, the Universe and us. The moment you say the Universe exists without any observers, I cannot make any sense out of that. I cannot imagine a consistent theory of everything that ignores consciousness...in the absence of observers, our universe is dead'. — Paul Davies, The Goldilocks Enigma: Why is the Universe Just Right for Life, p 271

And from the horse's mouth:

The problem with Time dilation is that it is another hypotheses i.e. possibility if you could fly in the speed of light. Could you fly in the speed of light? Could anyone? Even if you did, the result is not confirmed. It is a hypotheses — Corvus

https://en.wikipedia.org/wiki/Experimental_testing_of_time_dilation

Time doesn't exist. Space does. — Corvus

I see space like time - they are like measurements and measuring sticks at once. They are bound up with each other, as well as mass.

You have a mass, you have its own extension in space over time.
You measure time, you move a mass through space to clock your measurement.
You measure space, you hold a mass still through time.
It’s always one thing being measured where someone says “time” or “space” or “mass”.

We must be very cautious in introducing consciousness as an observer. The two things are not the same. The same has to be said about seeing and measuring, they are not the same.

Think of schrodinger's cat. it is not true that the cat is both alive and dead at the same time until we SEE it. Quantum decoherence has already taken place since it is not a completely isolated experiment; here the observer and the measurement is made by the environment as our apparatus. And it could not be otherwise: being perceived is not an act of physical interaction, that act of interaction is carried out by our technological devices or the environment.

https://en.m.wikipedia.org/wiki/Einselection

We must be very cautious in introducing consciousness as an observer. The two things are not the same. The same has to be said about seeing and measuring, they are not the same. — JuanZu

I don't much like the way Andrei Linde introduces the term 'consciousness'. I would prefer it if he stuck with 'the observer'. But then, Andrei Linde is a qualified commentator, he is a recognised expert in cosmological physics. He says in the interview that his publisher was very anxious about including his thoughts about consciousness on the matter - but, says Linde, he couldn't live with his conscience if he didn't.

My interpretation of the matter is simply that time has an inextricably subjective pole. So there's no truly objective time in the sense of being independent of any act of observation and measurement. This is implicit in what Linde says - that an observation requires there to be an observer and what is being measured. Time is only meaningful in that context - it is not truly observer-independent in the way that scientific realism might expect.

But that certainly doesn't mean, as the OP says, that time doesn't exist. It is far too simplistic an idea, and obviously problematic, as these very communications devices are reliant on measures of time.

I agree that there is irremediably a type of time that exists as Bergson points out. But I would not be so sure that it is something simply subjective. Thanks to Heidegger's analysis of Kant's work we have to say that the time we say is subjective is in fact constitutive of subjectivity itself, which determines it as objective or trascendental. This form of time I would say is more fundamental than the one provided by physics (because of the problems that arise when we think of time as a series of discontinuous points that follow one another).

Very good!

Maybe we measure oscillation. Not time.

So a duration of time like 10 seconds is number of ocsilations .
Each oscillation exists in a physical moment.
They don't exist simultaneously.

10 meters is in fact ...10 meters.

Not the same kind of measurements. — Mark Nyquist

Oscillation of what? I can measure many different things and use them as time such as the number of water droppings from the gutter while making a coffee. With the stop watch in the phone, it takes 3 minutes.

But I could ignore the phone clock, and use the water dropping clock, and say it takes 90 water drop time for making a coffee. Could it count as time as well? If yes, then which is the correct time for making a coffee?

There is a paradoxical co-existence of time. On one hand, only the present moment truly exists. However, the nature of the present moment differs from that of spatial locations and objects. The moment vanishes as soon as it emerges and cannot be carried into the next one. — Number2018

Is it possible to say that something exists, when the existence vanishes the moment it is perceived or realised? Existence means it keeps existing through past, present and future.

And it is neither a brief interval between the past and future nor a fleeting absence of being. — Number2018

Isn't it just a mental state? The ability to tell the difference between past, present and future using different type of mental operations in human mind i.e. memory, consciousness and imagination?

Thus, the present moment's reality is shaped by a virtual time, existing as neither what is no longer nor what is not yet, but as the difference between past and future. — Number2018

Virtual time? Remember when you were a baby and child? You couldn't have known what time is about. As you grew older, you learn about it, read about it, and think about. You have a concept of time. But the nature of time itself is still abstract. When you get older, they say time feels going a lot faster than when you were younger. What does it tell you? Isn't time just a mental state?

I agree that there is irremediably a type of time that exists as Bergson points out. But I would not be so sure that it is something simply subjective. — JuanZu

Actually, there is something I want to add about this. I'm not referring to the 'simply subjective' which is a rather dismissive way of framing it. The subjective pole of existence is not subjective in the sense of pertaining to the individual subject, but more in the sense of Kant and Husserl's transcendental ego - that which describes the structure of consciousness of any subject (or the 'ideal subject'). To quote an essay of mine on the issue, 'The subjective refers to the structures of experience through which reality is disclosed to consciousness. In an important sense, all sentient beings are subjects of experience. Subjectivity — or perhaps we could coin the term ‘subject-hood’ — encompasses the shared and foundational aspects of perception and understanding, as explored by phenomenology. The personal, by contrast, pertains to the idiosyncratic desires, biases, and attachments of a specific individual.' Which is what I think the second part of your post is referring to as 'constitutive of subjectivity'.

Thanks to Heidegger's analysis of Kant's work we have to say that the time we say is subjective is in fact constitutive of subjectivity itself, which determines it as objective or trascendental. This form of time I would say is more fundamental than the one provided by physics (because of the problems that arise when we think of time as a series of discontinuous points that follow one another). — JuanZu

This may be true of Kant’s work on time, but Heidegger’s notion of temporality deconstructs both subjectivity and objectivity, replacing the subject-object binary with Dasein’s being in the world.

I totally agree. I should not have said objective but only transcendental. But it is still true with respect to another form of temporality which is linear. Let us recall how the temporality of Dasein is determined as ek-stasis in which a linear and discontinuous description has no place.

Heidegger argues, if I understood well, that time is not something external to Dasein, but constitutes its very existence. The temporality of Dasein is understood on the basis of its ek-static existence, that is, Dasein is always projected beyond itself, towards the future, rooted in its past and committed to its present.

Of course physical objects exist i.e. chairs, desks, cups, trees, folks and cars .... I see them. I can interact with them. They have the concrete existence. Time? I don't see, or sense it. I can hear people talking about it, and asking it. So what is the nature of time? — Corvus

That is a much better question.

I was imagining and meaning some present moment in the future, when said "in due course". Not "at a later time". — Corvus

You acknowledge a future, and I assume you also acknowledge a past. This suggests a ordered relation: past->present->future.
We can label this ordered relation, "time". It's not a complete account, but it's a beginning.

That is a much better question. — Relativist

This is cool: Andrew Jaffe talks about Carlo Rovelli

The article is called "The Illusion of Time."

The table here is made up of molecules of cellulose with a few impurities.

Some folk conclude that what is real is the atoms and molecules of the cellulose, that the table is an illusion.

Some folk note that those atoms are mostly space. and again sups the table to be an illusion.

Neither of these is a sound conclusion. It remains that there is a table, consisting of cellulose and space.

The argument for time being an illusion is similarly unsound. It remains that the OP was written three days ago.

The problem here is not with time and space, but with the misuse of the words "illusion" and "real".

If n atoms compose the table, is the table the (n+1)th object? If there are a billion atoms, is the table the billionth-and-one object in this case?

Can you turn this into an argument? What is it that you want to conclude here?

Sure. I'll give you two for the price of one. Here's a modus tollens for the elimination of tables:

1) If tables exist, then a table is one more object in addition to the atoms that compose it.
2) A table is not one more atom in addition to the atoms that compose it.
3) So, tables don't exist.

With that in mind, here's a parity argument for the elimination of time:

4) Banno compared tables to time.
5) If so, then: if tables don't exist, then time doesn't exist.
3) Tables don't exist (the conclusion of the previous argument).
6) So, time doesn't exist.

Feel free to replace the predicate "exists" with the predicate "is real".

1) If tables exist, then a table is one more object in addition to the atoms that compose it. — Arcane Sandwich

The table is the exact same object as the atoms that compose it.

The table is the exact same object as the atoms that compose it. — Banno

Here are two reasons why it isn't:

1st reason: the table and the atoms that compose it have different properties. So, by Leibniz's Law, they're not identical to each other. For example, if you send the table through the wood chipper, the table ceases to exists, but the atoms don't.

2nd reason: if a table is identical to the atoms that compose it, then if you remove a single atom, you're no longer dealing with the same table, since if you represent both cases using sets, it turns out that the set of n atoms is not identical to the set of n-1 atoms.

The problem here is not with time and space, but with the misuse of the words "illusion" and "real". — Banno

Maybe not “misuse,” but certainly sloppy use, lazy use, imprecise use, shallow use.