Huh? 
What do you mean by that? Are you implying that there is more than one type of time? If so, you are greatly mistaken.
Completely incorrect. You seem to be confusing measurements of time with time itself. Time exists whether you have a means to measure it or not.
No, because even if the absence of all activity stopped time (which I don’t believe to be the case; time permits activity, activity does not create time); there is no privileged reference frame; it is impossible to know whether an object apparently at rest is really at rest or whether it is hurtling along at a million miles per second (along with everything else, that is).
Time is constant: It is exactly 1 second per second.
However, one person’s second can be another’s 100 years. This is the central tenet of Special Relativity.
Special Relativity arises from the idea that the speed of light in vacuo is constant.
After over a century of devising every possible test we have still not found anywhere in the universe where the above statement is not true.
From what I understand from your OP, you appear to be asking about the “flow” of time. There is no such thing, any more than there is a “flow” of space between two objects. Time is merely the axis along which events exist in the same way that (everyday) space consists of three axes along which objects exist.
Ah, but that’s the point. The proposal has been thrown out (by real scientists, not just Dopers here) that there is no such thing as Time. That it is an artifact of human perception.
Try to define Time, and you’ll see the problem. Perhaps that’s why so many people here are failing in their attempts to do so.
Time is difficult (if not impossible) to describe because it is so fundamental. It’s like trying to describe any particular dimension in three dimensional space.
However, there is no reason to think that time exists only in our minds.
In fact, that happenes almost every year.
Due to rocket launches, which slow down the earth’s rotation, international standards bodies adjust the length of the year each year, by adding or subtracting a “leap-second” (or part of a second) to account for this.
But note that it is the length of the day that is changed, NOT the measurement of time (the defined second). The official length of a ‘day’ has changed from 86.400 seconds (since first defined in 1820) to the value of 86,400.002 seconds in 1999. [See naval time or Google on “leap second” for more details.]
So the “speed of time” is not changing; rather we are adjusting our commonly-used, covenient divisions of time. Just like measuring distance by miles in the USA vs. kilometers in Canada – these are just different ways people define their conventional measurements – this does nothing to change the actual distance involved.
Is time perhapse the measurement of frequencies relative to other frequencies? When using nicely pure waves (such as laser light) the distance between two adjacent maxima can be measured as a distance, which since we know the speed of light is constant, can also be discribed and measured as a time. Different frequencies can be discribed relative to the frequencies of monocromatic light giving us something we can measure. This can be related to the rather more impure frequencies (such as the rotation of the Earth) and this gives us a way to measure the frequency of such and relate it to the thing we called time when we considered the earth to be rotating at a perfectly constant speed
Cheers, Bippy
“there is no reason to think that time exists only in our minds.”
Joe:
Actually, there is. In classical physics, time works like we think. Always moving forwards. In modern physics, however, the governing equations are symetric wrt time-- that is, they work just as well with time moving backwards as they do for time moving forwards. Now, that may be a flaw in the equations that will eventually be “corrected” but it represents the best we know right now. Just as Newton’s equation represented the best we knew 300 yrs ago.
No: I thought that maybe atomic resonance and Earth time were different, but wouldn’t atomic resonance be calculated with respect to Earth time?
At any rate our measurement of time is based on the changing positions of objects in space which is the main point I wanted to debate.
The natural conclusion of this theory which has not been seriously challenged here is that space is prior to time. Hence space and time are not an undivisible continuity.
time is a constant. what is not a constant is the effects of time on a given object.
For instance if you are in a rocket and you travel the speed of light for an hour as someone watches you on a monitor.
your perception and the effects of times passage for you the traveller would be that the trip was instantaneous as you would not experience the passage of time. For someone on earth however the trip would have lasted an hour.
This does not mean though that you have somehow slipped out of the “normal” time stream, and upon deceleration would find that an hour had passed for the rest of the universe. So really there has been no change in the time constant only its localized effects.
No it is not. Time, like space, can be “measured” (ie. "marked out) in any number of ways.
I hereby challenge this by pointing out that in Special Relativity the speed of light in vacuo is constant, resulting in time-dilation effects (eg. “one twin’s watch is slow”) and space-dilation effects (eg. “the fast train is shorter”). Nowhere in the universe to date has it been observed that c in vacuo is different.
But how is the speed of light measured? With respect to Earth time.
When measuring the speed of light using a light source moving with the Earth this is fine, but when you measure the speed of light from the Sun, using our measure of time does not seem to make sense as the Sun is outside our frame of reference.
For sunlight, it makes no difference at all if the Earth even exists so calculating its speed based on the rate of change of the Earth seems strange.
Arghh wanted to add more:
The obvious response is “a second is always a second for anything”. I’ll attempt to answer this more completely:
Meta-Gumble, Special Relativity does not merely “seem” strange, it is damned strange.
As I have said, the whole point of SR is that it does not matter whether the light source is moving towards you, away from you or is stationary next to you, or whether you are moving or stationary. It will be the same!
If a cyclist throws a ball forwards, the speed of the ball measured by a pedestrian will be the speed of the cyclist + the speed of the ball. Light does not do this.
No real thing in the universe is motionless…
The speed of light is the same, even if you are travelling at 99% of the speed of light the speed will still be the same in all directions…
Earth time is irrelelevant- it isn’t even constant at every point on Earth, and nobody uses it to measure anything (except on calendars)
what is it you are trying to say?
Sci-fi worldbuilding at
http://www.orionsarm.com/main.html
SentientMeat: strange isn’t the word …
I am just beginning to appreciate what relativity really means 
eburacum45
So what measure of time is used?
Physical events that take place over large areas with some regularity, in theory.
Arbitrary time regions in actuality. The only reason the whole system doesn’t fall apart is that the the errors, even in accumulation, don’t add up very quickly. As far as humans are concerned, the measuring systems are just hunky-dory.
Correct - the duration of a day would change. Instead of 24 hours, it might be 25 hours. The duration of an hour does not change. Under what circumstances would the duration of an hour change?
Time is a well-defined physical quantity. It has two separate mathematical representations. One is in terms of space-time and one is in terms of causality. There are intimate connections between these two definitions, however, if time was multi-dimensional, for example, the second definition would no longer apply. It’s because these definitions are all consistent with each other that we think we’ve got the idea right.
Saying that “time may only be the result of human perception” is wrong. One can be solipsistic, but time is just as well-defined as space. If you want to say the above quote, then, you have to also allow for the point that the three dimensions of space may only be the result of human perception. But then, what are we doing here in the first place?
But the OP posited that time was a “measure of change”. But even in the hypothetical comet, the “measure of change” would remain constant: several hundred million atomic cycles per second.
Indeed, EVERYTHING in the universe is presently defined in relation to something else. Our units of time are, however, the most “basic.” Our units of distance, for instance, are defined based on our units of time, so we can’t very well use them to measure the change in time, can we?