Does time flow?

Question

Numerous questions have been asked here about the nature of time, its existence and its origins, etc. Over on Physics Stack Exchange I have previously asked about the relativity of time, and obviously it was closed for various reasons.

However, in the course of positing the question, I learned that time, in the physics view, is nothing more than a co-ordinate position, that it does not "flow", that notions of past, present and future are questionable, that it has something to do with entropy, and also that the rate of change of time is one second per second.

I take issue, metaphysically, with several of these points.

Firstly, to say that time "does not flow" on grounds that it is a co-ordinate position (invoking perhaps the observationally correct thought that whatever time we occupy we still occupy this moment, so to speak), seems to me to contradict the idea of "space", or extension. For concerning the latter, if we always occupy the same "moment", then clearly we always occupy the same "position", which it seems to me makes any talk of the measurement of space moot. (Wherever we go, there we are!) That is, if time is a co-ordinate position, what does that say about space?

But space is not "moot". For within local experience, so to speak, we can take measurements, for example of the height of a table. We can extend our local measurements and find ways of measuring greater distances.

But still, space is just a co-ordinate position. Can you see how there could be parallels with these conceptions of space and time, particularly, contradictions?

Furthermore, they say that the rate of change of time is one second per second. This, if we can be completely honest, is really nonsense: you might as well say that the rate of change of space is one metre per metre, or that length is measured one metre per metre!

Now, if time does not really flow, perhaps it really is an objective substratum that only gives matter its directional properties, and that is fair enough.

But inasmuch as matter can be an extension in space, and it is just a co-ordinate position, can time under this rubric therefore flow, perhaps as a limit or limited to local experience? For time is in the waiting; we expect something, we feel time pass, and we finally get there.

Answer 1

You are missing a crucial point- time is a coordinate, and for matter the value of the coordinate is continually changing. Time does not flow, but you move through time. The complexity of relativity is that there is no absolute direction of a time axis in spacetime. If you and I are moving relative to each other, our individual time axes are tilted relative to each other, so that your time axis is not orthogonal to my space axes and vice versa. Moreover, your time axis is curved by the presence of matter and energy, which creates the effect we think of as the force of gravity. As you coast along your time axis its curvature moves you through space in a downward direction towards the centre of the Earth.

Answer 2

Here is a apt quote where Heidegger talks about time flowing. This is in the 'ordinary' sense of time. In the experiential 'ecstatical' sense we are always in the now and see the minutes pass. It's tricky to see the difference if one assumes experience is the observation rather than the observing.

for the ordinary understanding of time, time shows itself as a sequence of "nows" which are constantly 'present-at-hand', simultaneously passing away and coming along. Time is understood as a succession, as a 'flowing stream' of "nows", as the 'course of time'. What is implied by such an interpretation of the world-time with which we concern ourselves?
We get the answer if we go back to the full essential structure of world­-time and compare this with that with which the ordinary understanding of time is acquainted. We have exhibited datability as the first essential item in the time with which we concern ourselves. This is grounded in the ecstatical constitution of temporality. The 'now' is essentially a "now that . . .". The datable "now", which is understood in concern even if we cannot grasp it as such, is in each case one which is either appropriate or inappropriate. Significance belongs to the structure of the "now". We have accordingly called the time with which we concern ourselves "world-time" . In the ordinary interpretations of time as a sequence of "nows", both datability and significance are missing. Being & Time 422

Without the significance given by concern (attention) for a datable moment the only scientific meaning of a moment is that it is the n^th vibration of an atom or the 2025^th orbit of the sun, so to speak.

The caesium standard is the scientific definition of time which can be used to link datable moments to a physical phenomenon. The 'moment' now is given reality by ecstatical experience. More than that cannot be expressed without explaining existence in general, which is itself problematic. Now is 2:03pm.

106. The Now is pointed to, this Now. 'Now'; it has already ceased to be in the act of pointing to it. The Now that is, is another Now than the one pointed to, and we see that the Now is just this; to be no more just when it is. The Now, as it is pointed out to us, is Now that has been, and this is its truth; it has not the truth of being. Yet this much is true, that it has been. But what essentially has been [gewesen ist] is, in fact, not an essence that is [kein Wesen]; it is not, and it was with being that we were concerned.
     – Hegel, Phenomenology of Spirit, trans. A. V. Miller (1977), p. 63.

A disembodied mind would be all the time just the moment of awareness, but since we are attached to and composed of the physical material we encounter datable events which we can set to a scale and watch them tick by.

Answer 3

According to (the Meiklejohn translation of) Kant's first Critique:

... quantities may also be called flowing, [if] the synthesis (of the productive imagination) in the production of these Quantities is a progression in time, the continuity of which we are accustomed to indicate by the expression flowing. ... space alone is permanent and determines things as such, while time, and with it all that is in the internal sense, is in a state of continual flow...

The German original (of the B-edition) reads:

Dergleichen Größen kann man auch fließende nennen, weil die Synthesis (der produktiven Einbildungskraft) in ihrer Erzeugung ein Fortgang in der Zeit ist, deren Kontinuität man besonders durch den Ausdruck des Fließens (Verfließens) zu bezeichnen pflegt.

... which Google Translate spells out as:

Such magnitudes can also be called fluid, because the synthesis (of the productive imagination) in its production is a progression in time, the continuity of which is usually designated by the expression of flow (dissolving).

We don't seem to have, here, a very "technical" description of time and attributions thereto. So what is the sense of the sentence, "Time flows"? If we take it as movement, then Kant actually disputes this:

... change does not affect time itself... If we were to attribute succession to time itself, we should be obliged to cogitate another time, in which this succession would be possible.

Perhaps, then, "Time flows," is a metaphorical way of saying something like, "Time is active." Time "pushes" its contents forward through it, carries them like the current of a river does a boat. Or, like a magnetic current might, it moves them by pulling them along its course.

But all that depends on there being a stable, and fairly precise, referent for the word "time" itself. Kant has a transcendental definition, that the referent of the word "time" (or, its German correlate) is "whatever synthetical faculty reconciles changes and noncontradiction." Modern physicists consider an entity united with the intended (older) referent of the word "space," i.e. spacetime.

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Addendum. There is a somewhat recent paper which uses the phrase "flow of time" and which is a rather confident statement of a theory to explain this phrase's intended meaning:

Since the photon carries energy in its period of time, a flux of photons inexorably embodies a flow of time. Thus, time comprises periods as a trek comprises legs. The flows of quanta naturally select optimal paths (i.e., geodesics) to level out energy differences in the least amount of time. The corresponding flow equations can be written, but they cannot be solved. Since the flows affect their driving forces, affecting the flows, and so on, the forces (i.e., causes) and changes in motions (i.e., consequences) are inseparable.

Their apparent conclusion is then that "time does not move forward either but circulates."

Answer 4

Events flow simultaneously during a natural process. Historians claim that Galileo used water clocks and pendulums to specify time. In a water clock (or hourglass) the events we associate with time are recognized as irreversible. In a system with periodic motion or similar natural process the events we associate with time are recognized as a simple harmonic oscillator. A pendulum clock is a simple harmonic oscillator. During every instant of time the clock is in a particular state and the surroundings are in a particular state. Together the clock and its surroundings are in the stream of events flowing simultaneously. We only isolate systems that are in uniform angular motion (such as the polar arc swept by stars in the Northern sky due to the rotation of earth), or in periodic resonance, or in an irreversible flow, to invent the coordinate we call time. Today we stimulate Cesium-133 atoms with microwave radiation, observe atomic resonance, and specify 1 second of time as so many resonant periods.

Imagine witnessing Galileo's experiment wherein he starts a pendulum clock moving in simple harmonic motion. In sync with the beats of the clock he rolls a smooth round ball down a smooth track in an inclined ramp, lets the ball roll across a horizontal table, and lets the ball fall off the end of the table to the ground below. Time is the concept that the pendulum clock has a uniform period for each beat while the motion of the rolling ball makes a displacement in spatial position. There is no flow of time in any snapshot of events. There is the position of the pendulum and the position of the ball in any given snapshot or instant of time.

Answer 5

"time, in the physics view, is nothing more than a co-ordinate position"

1. That depends on whether you are talking about a specific moment or a period, v" time" can refer to either. You seem to be confusing the two. Compare with location versus motion.

2. Location is a coordinate position. Yet location changes smoothly with elapsed time; we call that motion. For that to happen, elapsed time must change smoothly.