Most of out time-measuring instruments are based on repetitive physical phenomenon. These phenomenon repeat and every time their state matches the one in our recent memory, we tend to acknowledge, that a unit of time has passed.

on the other hand, Our mind's states never repeat exactly the same. The only blurred idea is given by the rate at which we can sense and acknowledge the tiniest change around us. With a little help from memory, we can tell apart "Events" if one happened before other etc. (Can this rate/ability vary, due to alertness levels, or like computers, our mind too has an upper limit of thought processing speed, are yet more questions to be investigated).Consider our mind as a camera shooting at variable FPS.

These two notions of time: a physical clock, and a mind aware of changes at different precision levels, do not seem to adjust too well. The difference appears in the "speed of time"(see below questions) , physical clock's have a constant one, while our mind seems to take some liberties with it. And yet everything is considered to be happening at the same time.

This subtle disparity, begs some questions:

  1. Is the notion of a "speed" of time a logical one ?
  2. if so, then is our perception of speed of time "flexible" ?
  3. If both above are true, how do the unchanging physical clocks fit in this ? Does our mind skips/freeze some frames to stay in sync ? Or does the time bends itself to fit each mind's speed ?
  • 3
    I think you know that the answer to your last question is: yes. But reading all your questions, I'm too confused to write anything else. What kind of answer do you expect? And is it more philosophy or cognitive sciences or physics maybe?
    – FolksLord
    Oct 4, 2012 at 18:17
  • 2
    I'd be amazed if anyone even had a real answer to this. A guy can only hope...
    – commando
    Oct 4, 2012 at 20:08
  • @volkerjaan OK,I've updated the question, a little more clearer about the questions I have in mind. I'll refine it further when I have some more Insight.
    – user2411
    Oct 4, 2012 at 20:23
  • "Our mind's states never repeat exactly the same." Why do you say that?
    – Snowball
    Oct 4, 2012 at 22:08
  • 1
    @Snowball Its impossible for us to simulate a timer, perfectly accurate like a physical clock, in our mind. Even if you Imagine one sheep jumping over the fence every time :)
    – user2411
    Oct 5, 2012 at 5:09

8 Answers 8


I gather your point is that the perceived rate of time is always changing. Similarly one could argue that as one grows taller, their perception of distance and size also changes (i.e. I sometimes see objects now that look tiny compared to how they looked when I was a child). However most people recognize that the objects themselves aren't getting smaller, but rather we are getting bigger and it is our perceptions that are changing.

This approach considers ourselves to be subjective observes in an objective universe, and this is also my belief. Similarly for time, I believe we should recognize that while our perceptions of time change, the objective underlying nature of time remains constant (assuming you don't suddenly start travelling very close to the speed of light).

In conclusion, the "speed" of time makes about as much sense as the "speed" of distance, which most people are happy to accept does not exist.

The rate at which time is perceived to pass however is a logical notion, but the present state of science doesn't allow us to test this. Perhaps in the distant future, neuroscience will be able to measure such a thing.


Is the notion of a "speed" of time a logical one

Why, yes it is though maybe not in the sense you're looking for. In both Special and General Relativity, time is a spacetime coordinate on the same footing as the spatial coordinates.

"Trajectories" through spacetime, called world lines, are parameterized by "proper" time which is roughly the time according to a clock on the worldline.

We can take coordinate derivatives with respect to the proper time parameter to get spatial and temporal "speeds", i.e., the derivative of the time coordinate with respect to the proper time is the speed through (coordinate) time along the world line.

  1. the speed of time is not an intrinsically fixed speed to us, but the order of events is always fixed relative to every alive species. However, look at this like the issue of a Real-axis in math, the points on a Real-axis are all ordered but too dense as well; each species can only sense and realize down to some small time-scales, so we can only talk about short time-intervals but never precisely an individual instant of time! Human can always try to improve his perception of time by shortening his realizable-time-intervals (the concept of time instant understandable to each person), as you may already be familiar with such techniques, relaxations and things like that. Being nervous would always reduce the perception of time, so elongate the shortest time sensible to the person, so increase the speed of time sensed by that person.

  2. yes, it is flexible as explained above. This can even elongate the person's lifetime, note that those who live a difficult life, roughly speaking always sensing every bit of a time interval, would appear more aged than those who have lived easy lives! Although things are not as simple as denoted here, only to give a starting point for further thinking.

  3. what do you say about those situations that a some-days-long story is lived and experienced very realistically in a dream seen within not more than 10 minutes? Souls can realize the time better (with higher resolution) than the material body if you ask me, however, I should add the point that time is not the only mis-concepted notion of the modern science, material is another one, and material can be treated to do whatever the soul can do either and there are witnesses for that in Shia Islam teachings.


  • 1
    changing one's own perception is one thing; however, your claim #2 would need significant support - sounds more like something that could be addressed on skeptics.SE; for #3, when discussing physical phenomena, alleged witnesses in religious teachings are not really a substitute for critical observation, due to their subjective nature and uncertain (disputable - multiple religious views, etc) pedigree Oct 18, 2012 at 10:59

I try to explain from different direction. See if we can put "time" at the correct understanding. And see if we can put any other understanding (speed of time, etc) relevantly related to the understanding of THE NATURE OF TIME.

There are different time that are perceived through comparison.

But, there is (closer to) one time, (closer to) "no different times" that are perceived through comparison, by comparing to the movement of (closer to) the root of all particles. Where all events are framed, and stuck on the consistency of the beats of rhythm of pulses of (closer to) the root of all particles.

One time for all events, one step for all events, more steps for continuing all events.

  • (Closer to) one time for multiple times. Which one do we choose? Multiple times or (closer to) one time? Practically, multiple times for interactions, essentially, (closer to) one time for integration.

  • The more we consider getting closer to the root of all, the more we realize that there is (closer to) one time, (closer to) one typical of speed. How do we apply (adjust) it (for our frequency)? From duality to non-duality.

It's similar to consistency within electricity. It's the same voltage (the same typical of consistent speed) which generate various events which may be used to generate various comparison, which may lead us to perceive different times, different speeds.

I believe (closer) to the root level of particles, all of these kind of particles (closer) to the root level, ONE TO ANOTHER, have the same (or closer) frequency and pulsating at the same (or closer) moment (it's like two metronomes are playing identically) no matter where they are. I will leave it to scientist to prove (perceive) it. It's universal time, where time can be measured based on this understanding.

To simplify my understanding:

If there are times, then there are changing continuously without moving anything. Consider when we are watching movie. The story in a film represent sequences and we will see time differently, but there was nothing moving out of television. All artists were playing within display. If somehow we put consciousness inside the film on specific artist (just like dubbing), then the artist suddenly would realize that there was time stuck on a movement. But people outside the box (we were watching) knew that there was no movement 100 meters jumped out of display. The display may stand still, and the liquid inside the display was still there.

We saw time within a film. We saw different times, but according to the player (DVD or VCD player), there was only one time for all actions on a film. One time with consistency. From within a film there was different time, different speed, but from outside the film, there was (closer to only) one time, (closer to only) one speed.

It's like changing a specific binary number one at a time continuously and it will change the whole story continuously. It's like rolling a binary number once or multiple times for one or all events. All events are changing at one time continuously. If we can "pause or play" all events, then "one click for all events", one click again to change to different set of all events.

If we compare between our expectations with the size of the steps to achieve what we expected based on the general view or a particular view. Then we will feel that "we are waiting for something so long", or at reasonable (speed of) time.

But if anything follow "the one time" (as described above), then our perception of speed of time maybe agreed generally (at least on majority level).

Speed of time depends on where to put our perceptions on changing based on "one time" or relatively.

  • We do have atomic clocks, well that's the best science can do for now. However, It's all subjected to relativity, which spoils the universality of such a standard.
    – user2411
    Oct 5, 2012 at 6:29
  • @wingman thanks. I wonder if, at the deeper level than the atom, perhaps at the level of "string theory" or even deeper, we can perceive that, all possible strings are vibrate at (closer to or) the same time? Just to assert that any changing everywhere are changing from one step to another changing at (closer to or) the same moment. One change for many changes locally. But yes, it's subjected to relativity. But yes, perhaps we can perceive it, even closer at "one time" for all events through meditation (all flowing at one vibration. One breath for all lives ...) Thanks :)
    – Seremonia
    Oct 5, 2012 at 12:16

The time affect everything that changes. In fact, without any change, there's no way to say how fast (or even if) the time flows. It's more like the concept of time-and-space in contemporary physics - the time is the dimention, and we travel in time, therefore we see the world changing, while the mass and energy have other configurations in other points of time.

We don't see the time, neither can we see how it flows. We see only the changes in our environment. We can measure time because some things go on regular basis - such as the rotation of the earth.

But, when we say, that time flows longer, or faster, what do we mean? When someone is bored, time seems to flow very slow. When someone is deeply engaged, the time seems to flow extremally fast. But it is not the subjective speed of time we feel, but those are our emotional state and our want to change current situation (or not). If I'm bored, I don't feel the time flowing slow but I'm feeling the urge for the future moment to come faster. When I'm delighting the current moment, I don't want the future to come. So, my emotional state affects how I feel about the "speed" of time.

But, what contemporary cognitive sciences are teaching us, our whole identity is our state of mind - in the current moment. With the time, our state of mind changes, but we feel it as the changing of our state of mind - new thoughts, perceptions, emotions - but not as the flow of time itself. We know that time have passed because we have memories. If we are out of memories, we are like the man from the book "The Man Who Mistook His Wife for a Hat", who was kept in the current moment, without past and future. He wasn't aware of time flowing because he lost the ability to memorize new things, the only thing that makes us aware that the time is flowing - and that the time exist.

And finally, you ask how physical clock has to do with our subjective feeling of time. We understand what the clock is, so seeing the clock we think about the time flowing. We can measure how much time something has taken, we can think about time seeing the clock ticking, but nothing more. The second seems to be the sime for every watcher of ticking clock, but try to sit with a few people for a few ours - each of you will feel those whole time in the other way. If you leave only the seconds handle, removing those for hours or minutes, and ask after 3 hours how much time has passed, each of them will tell the other number (except someone will be counting minutes manually - a rare case).


I believe the speed of time to be inversely proportional to the size of the one who perceives the movement of time. Time is, after all, the difference between two dissimilar events. The ability to measure time is directly proportional to the ability to measure one event as dissimilar to another. This can only be done through the senses, primarily via light (and other electromagnetic waves). Light moves at a fixed speed. However, the larger the size of the viewing body, the slower light would seem to travel.

Imagine you were the size of the Milky Way galaxy. At this size, the relative speed of light would crawl along at an imperceptibly small rate. In fact, there would be a complete absence of any motion at all, if the rate of time were perceived as we humans feel it. The only way to sense the motion of time is if it moved hundreds of thousands of times faster. A thousand years to us would only be a moment to this galactic body.

Now if you were the size of the universe, and all mass and energy were contained within, you would never detect the movement of light and therefore time could not exist. Nothing would ever change. All times would exist concurrently.

To those of you that subscribe to the theory that God is the universe, of which we are a part, it makes total sense to say that God is "eternal" or time "doesn't exist" for God.

  1. If by logical you mean sensed from real, equidistant events, no its not. Experience tell us so that even physical time keepers are not constant. To prove it you just have to build more accurate clocks. If by logical you mean a mental construct, yes it is. I disagree with your statement that "most" of time-measuring instruments are based on repetitive physical phenomena. I think its all of them. It all involve repetition. And relying only in that physical instrument, we have no way of knowing if the duration remains the same or equal in all the cycles or units of time. Take for example the day (including nighttime). Before the invention of timekeeping instruments, who knows if one day is longer than another day. Now ofcourse we know because we have atomic clocks and not all days have 24 hours exactly. But how do we know if the atomic clocks are themselves constant, since any physical laws that would affect these clocks will also affect the other physical objects you're trying to benchmark it with? That's why for me, its hard to accept time dilation in Einstein's relativity theories, since speed is involve, it must have affected the clocks. But I am not a physicist so can't expound on that.

  2. Yes. See above. Also, have you experienced being in a room without clocks for an extended time? Once you come out, you wouldn't have a clue what day it is much less the time, especially if you come out to another room which is maintained at the same state as when you get into the room. The sensation is like time has stopped, until you learned later what the real time is.

  3. See #1. The mind does it all, stretching and squeezing the events to fit within the physical time as reported by these physical clocks. I don't conceive of time as having frames, or being able to bend. I think of it as an elastic band. I believe that both our perception of time and the underlying physical reality of time are both not constant.


Well, there is Bergsons notion of the duree; but here I'm going to focus on the physical notion of time.

For Aristotle, time is an aspect of motion; the most prominent exponent of this view today, is perhaps Barbour; time then would be an emergent phenomenon - it comes to be.

In Physics IV.14, Aristotle writes:

Any changes whose limits are simultaneous have the same time, even if one change is fast, say, while another is fast.


The time of the alteration is still the same, provided it is equal and simultaneous, as the time of the movement. And this explains why, although changes differ from one another and occur in different places, time is everywhere the same.

This though, empirically situated: for do we not see this and feel it everyday - now I drive quickly and he slow - but time taken, as we take it - the same; when this is taken as a principle (but perhaps not as arche); it becomes Newtons notion of absolute time, that flows everywhere the same at the same rate.

A, goes on though:

Now, there is such a thing as movement, and one kind of movement is circular movement. Also, every kind of thing is numbered in terms of some one thing of that kind - units, in terms of a unit, horses in terms of a horse, and so too time is numbered in terms of a determinate time.

A is looking for, the simplest or most basic measure by which time can be measured; then:

It follows from all this, that if that which is primary is the measure of everything akin to itself, then uniform circular motion is a measure par excellence.


because it's number is the most intelligible number there is, there is no uniform alteration, or increase, or coming into being - but there is uniform movement.

Why says he this?

When a boy alters, and becomes a man; what he is before, and what he is after, is distinct and different.

Or when the colour purple is diluted and becomes violet or vermillion, then this too, before and after, is distinct and different.

This, then, is alteration; and it is not uniform; for what it is before, and what it is after - is perceptually, or in itself, or by relation different; and not the same.

But when a ball moves from place to place, and it in itself does not alter; and each place the same; then motion is uniform: though there is change, no change is perceptible - either in the ball itself, or by place.

Also linear motion cannot be potentially infinite, for at some point it would turn back; therefore potentially infinite motion is circular.

This, then, is uniform motion.

It's commonly taken, at this point that A identifies time with the motion of the heavenly sphere; but this isn't what he says; he says rather:

the reason, then, why people think of time as the change of the heavenly sphere is because all other changes are measured by this change; and time too is measured by this change.

Other people think - not A, himself. He identified a properly basic concept of the physical measure of time - but moves no further to it; instead, he gestures towards an analogy.

The basic measure of time is the motion of light - as acknowledged in GR; it is that which is both absolutely at rest and absolutely in motion - both ie equivocally; and it's phase moves in a circle, and this motion is uniform.

So, the question is coherent; and the basic 'logical speed' of time is always everywhere, in itself - the same; what changes, is to see from here, there; ie relatively, from this place, to that place; and then, dilation or contractions of time ...

As though seeing through, a glass - darkly.

ie refractively.

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