Tag Archives: tide

Temporal Measures are Like Currency (Standards for Experienced Duration 3)

Previous: Time and Tide Previous: The Windowsill Clock Note: The three posts here inspire my thinking in my more formal paper ‘Against Illusions of Duration‘, published in the anthology The Illusions of Time (which I co-edit with Arstila, Bardon, and Vatakis). However, along with being less formal, these three posts develop the ideas in much more detail than that paper.


The man is bemused by this exchange. His colleague makes some tea and sits by the window. Looking out at her ‘clock’ (or, he thinks, exactly not a clock). “How about this” she says, after some while (or other). “Let’s define a new unit of time. A unit to which we can neutrally refer. It refers to what an hour, second, etc. refers to, but can be linked to any standard. The tide, a dripping tap, experience, etc.” “For standard time — that measured by a clock — it might be a second, minute, hour, day; whatever you like. But for any other standard or means of measurement, it needn’t correspond to a clock hour, second, etc.” The man grunts. “And what will we call it?” She scratches her ear. “I don’t know….a moment, perhaps? That seems neutral enough.” He grunts again. “That’s very general. It could mean anything. A second, a millisecond, a year, even, given the scale.” She dips her head to the side (like the sea did). “That’s right. Or, at least, it is empty. It denotes a unit of time without any specification of what defines that unit. It’s like units of currency defined without talking about pennies, pounds, kroner, cents. But here’s the thing: that’s good. We shouldn’t be judging time measured by the tide as accurate or inaccurate according to the clock. They are completely different processes. It is ridiculous to do so, even if they coincide occasionally. You wish to hold on to the terminology of ‘hours’, etc.. Any use of these terms implies evaluation with respect to a clock. It is always an Hour O’Clock, never an Hour O’Something else. So we need a new set of alternatives for other measures of time. First,  some neutral terms referring to any unit of any measurement of time. Without the presupposition that we mean clock time — or tidal time, or even experienced time. Second, for each measure, specific terms if we like. We might do it by qualifying the neutral term, e.g., it is X Moments O’Tide. For the particularly common measures, we might use condensed terms, or even familiar terms. Obviously, for the standard time of human society, we use ‘seconds’, ‘minutes’, ‘hours’. So, now I say it takes ….4000 tidal moments for the event to happen and there is no problem with the clock — at least, initially. Two last things. First, like currency, these measures can be translated into one another. But they aren’t required to stay in fixed translations. Say a moment of tide matches a GMT hour on one occasion and not on another. This is not a reason to reject either the tide’s measure or GMT. It’s not evidence of error on either side. It’s evidence of a complex relationship between them. — It’s like the relationship between the kroner and the yen. — It’s not like the relationship between a good dancer and a bad dancer. Or a bad painting and a good painting. Second, I might give a rough answer to a question about how much time has passed in clock time. But what I’m doing is basing it on a guess as to how tidal time translates to clock time. It’s like if you asked me ‘How much does an umbrella cost?’ in Kroner. I have no idea; but in my home country, in Japan, I know: I look at one for sale in the local shop window. If you insist ‘tell me in Kroner‘, I can try an answer, of course. But I’m not looking in the shop window at the price. I’m guessing based on all sorts of half-rules and -remembered bits about the two currencies relationship. If you used my answer as a base to judge that I don’t know how much an umbrella costs at all, or am under an illusion of its price, I think it’s fair to say you have gone wrong in your thinking, not me. Sure — I get the wrong ‘kroner’ answer — but I don’t have any information about the kroner answer, except the half-stuff I have about its relationship to the yen. It shouldn’t surprise you, then that when you ask me, in clock time, ‘how long does it take to walk to the beach?’, if I say an hour, I can be quite off. But I am not deviating or misjudging the clock time duration. I am guessing the clock time duration based on a measurement of tidal duration. There is a complicated relationship here between two measures:

i. One which I am using to measure time.

ii. The other in terms of which you are asking me to answer.”

“That is a lot of work?” said the man. “Yes, it’s complicated. Doesn’t make it false.” (Now it’s time for a pint).


On the experience of time:

(1) Illusions are instances of inaccurate experiences (or non-veridical or false experiences).

(2) A typical judgement of experiences of duration is based on matching clock time with experienced time, e.g., a clock-read hour matches an experienced half-hour (if you’re having fun, by all accounts).*

*Strictly speaking, it involves matching clock time with a reported experience of time. But assume for the moment that the reported experience accurately captures the experience.

(3) If you look at the literature on time distortions, illusions of duration (I’ll be very interested in any exceptions to this), you get this idea:

An illusion (or distorted experience) of duration is classed this way because the experienced duration (e.g., the half hour) does not match the clock duration (e.g., the hour).

(4) Like the tide, we aren’t using the same thing to judge the time. We are perhaps measuring something in our experience of time, e.g., such as a succession of emotional/introspective/physiological states. The relationship between that and clock time is, as with the tide, like the relationship between currencies. It’s complex.

(5) This complexity is not a sign of an inaccurate measurement under a common system on the part of either clock or experience. It is a sign of two different measurement systems.

To judge an illusion of duration with standard clock time, then, we need to do the following:

(6) Have a correct system for translating measures in terms of clock time to measures in terms of what is being used in experience,

(7) Whatever value we get in standard clock time, use the system in ‘6’ to translate it into the measure of experienced time.

(8) This value in experienced time is, at the very least, the better candidate for judging the reported experience of time.

I think, actually, that the idea of even judging in the last point, in ‘8’, is more complicated than that. But I leave it here for now.

The Windowsill Clock (Standards for Experienced Duration 2)

Previous: Time and Tide

Note: The three posts here inspire my thinking in my more formal paper ‘Against Illusions of Duration‘, published in the anthology The Illusions of Time (which I co-edit with Arstila, Bardon, and Vatakis). However, along with being less formal, these three posts develop the ideas in much more detail than that paper.


The real problem the man has with the sea’s timekeeping is not with the sea. It is with his ex-colleague, who uses the sea to judge time.

His colleague recently retired and has a house on a cliff near the sea. From the house, there is a clear view of the tide as it comes in. For his colleague, a second is a single beat of the tide — a single instance of waves lifting then falling back. A minute is how long the tide takes to spread over the long stretch of sand; an hour a multiple of these. The man’s colleague has marked these on the windowsill facing the sea, and so can measure any needed time.

“Those are not seconds, or minutes, or hours”, says the man.

“Yes they are.”

“No they’re not — seconds, minutes, hours are defined by standard time. This does not correspond to standard time. It is misleading and unreliable.”

“It is accurate and reliable for me. I live by the beach. I can check it any time. The tide is a better means of measuring time than the standard clock.”

“But you’re not measuring CLOCK time,” the man says in frustration.

“You’re right….” the other is thoughtful for a moment. “Well, ok, so I shouldn’t call it four O’CLOCK. I should call it, maybe, four O’TIDE. This acknowledges that I am not measuring time by the conventional clock. I’m measuring it by the sea. How about that?”

“No no no — nonsense. You’ll confuse a lot of people.”

“Well, who am I going to confuse, other than you? I live at the edge of the sea, on my own. I am not trying to measure something by the standards of other people.”

“You’ll confuse anyone — anyone who asks you what time it is.”

“Only if they assume I am measuring by a standard clock. But I’m not. And if they ASK me, they’ll see I couldn’t possibly be measuring it by a standard clock. I don’t consult one; at best, I look toward the tide (it’s visible anywhere in this town) and then give them an answer. They’ll know then that what I call an ‘hour’ obviously cannot be a clock’s hour.

If they notice my looking at the beach, they might guess it is a certain period in which that tide moves across the sand.

Once that’s understood, then that what I call an ‘hour’ doesn’t correspond to the ‘hour’ measured on your wrist should be unsurprising.”

The man sighs. “But that’s just the thing you see. You use the concept of an hour to describe a particular passage of the tide. But an hour is something defined by the motion of a watch. If you insist on calling a certain period of tidal motion an hour, you’ll be inaccurate. It’ll be different to the watch, which sets the standard.”

The other thinks about that as well.

“Well, first, I’m guessing that ‘hour’, ‘second’, and the like aren’t so tied to the current clock. They were there before it. But the current clock is so ubiquitous that we automatically think of that. Most people mean by ‘hour’ a unit of standard clock time.

And, yes, I even used that standard to originally pick out a period of tide to be an hour. A long time ago, when I still had a watch, I noticed that when the tide crossed a particular patch of sand, my watch’s hour hand completed a whole circuit on its face. When I lost that watch, I had no other standard clock. So, initially, I used the passage as a substitute.

But over time, I didn’t. I just use it to measure time. It suits me very well out here.”

He scratches his head. “But don’t you see how inaccurate that is? The tide and clock needn’t match. You’re using an uncalibrated process to makes measurements in terms of a standard.”

“…I am. Except….well, as Wittgenstein said “There is one thing of which one can say neither that it is one metre long, nor that it is not one metre long, and that is the standard metre in Paris.” Similarly, there is one thing of which one can say neither that it is one Tidal Hour long, nor that it is not one Tidal Hour long, and that is the time it takes that tide to cross that stretch of beach. It sets the standard, not gets measured by it.

I am not calibrating what I use to measure time to a standard because I am using the standard itself. The standard is the tide’s motion. If I was making a clock from it, I would calibrate it with what I’m using to measure.

But yes I am not using the standard of the standard clock — of GMT. But I don’t see this as worse than what you use. You just calibrate it differently — by your wristwatch, your phone, the six ‘pips’ on the radio or, if you can get at them, vibrating caesium atoms. In fact, it is more like I’m using the caesium atoms themselves to measure time.

But, again, I take your point. I link the term ‘hour’ to a process of the tide based on a number of instances in which the tide coincided with the clock. I may be accurate in using the word ‘hour’ afterwards because I am judging it by the tide. But I am not accurate if I am judging it by your clock.

Most people will ask me for the time according to the clock. They will take my answer as being a judgement based on the clock, and act accordingly. I can see them getting quite mad at me if they do. Although it hasn’t happened yet. Typically, they don’t see me looking at my watch, so I expect they know that I’m not using standard time to get the result.

But — again, yes, it is a problem to use hours, etc. I myself have sometimes slipped into the habit of forgetting that I am not using something set by a standard clock. How could I be judging by a standard clock? I don’t have one, or anything that calibrated to one.

So, maybe I should call it something else.”

“Yes.” says the man. “It only causes confusion otherwise.”

“It does.” She is thoughtful again. “However, it also causes confusion if you assume one measurement is correct over another in measuring events. And is also causes confusion to ask someone to judge the time or duration and then insist that an answer is only appropriate — and so right or wrong — if it is in terms of an irrelevant standard.

Such as when you come up to my house and ask me what time it is or how long something lasts. You ask me ‘how long does it seem to be?’ and then you only accept an answer in terms of clock time — clock seconds, clock hours, etc.

What can I say except answer in terms of clock time, even though that is no measure of accuracy for what I am using?”

After a few more seconds of thought, the other frowns. Abruptly, she says: “I think the rules of your questioning are exacerbating the problem.

The problem has got nothing to do with how accurate my measurements are. I’m using the tide to measure time. My answer is to be judged, if at all, by the tide. It might be accurate; it might not.

You’re asking me to use it, however, to make judgement in terms of clock time. Then you’re calling my judgement inaccurate — a mistaken judgement of duration — when it fails to match the clock time.

Yet, except for that brief association in the past, I’m not using clock time. (I’m using clock terminology, of course, but that’s because you’re asking me to answer in clock terminology).

Given I’m not using it to make my judgement: Why oh why do you expect my answer to match the clock?

Why do you even expect it to be judged by a clock.

There’s no clock out here. The only means of measurement is the tide.”


My thinking is this:

If you ask someone to judge the length of a certain experience, to give a value to a certain experience of time, then

If they give an answer which is incorrect according to standard clock time, either

(a) What they are using to measure time has gone wrong — if what they are using to measure time is supposed to be calibrated to standard time, i.e., it is a standard clock.

(b) What they are using to measure time is not obviously gone wrong — if what they are using measure time is not supposed to be calibrated to standard time, i.e., it is not a standard clock.

Experience corresponds to (b). It is not a standard clock.

Experience should not be treated as if it is a standard clock. Whatever it is that prompts us to describe our experience in terms of clock time, it has nothing to do with the possibility that our experience is either calibrated to a clock and/or should be evaluated in terms of clock time.

So how can we work with the different measures? And how should we understand them?