About time
Time and space, together, form a system of reference that allows us to make sense of reality. In very simple terms without the concepts of after, now, before, here and there the world would be very confusing indeed.
That said I need help on whether time is an invention or a discovery. Is time like a moon of a planet we've discovered or is it like latitudes and longitudes, invented to aid us in our understanding of the world?
A few things I understand about time:
1. [I]Change[/i] is essential for time. In a world without change time is meaningless. This I understood by imagining a world where we're immortal (changeless). To an immortal there's no difference between 1 second and 1000 years - time doesn't affect an immortal.
Similarly, imagine a world without change - no movement, no chemical reactions, absolute motionlessness (heat death of the universe?). In such a world, time would be meaningless and it'd lose its value as part of the space-time frame of reference.
2. Following through on 1 above, it isn't change per se that is necessary for time, specifically its measurement. We need a specific type of change viz. [I]cyclical/repetitive[/i] change for the notion of time to be useful. The day-night cycle, the year and down to the cyclical transitions of atoms - such repetitive phenomena are absolutely indispensable to time measurement.
Imagine that such cyclical phenomena were nonexistent in our universe. It'd be impossible to measure time and so, time would, again, be meaningless.
3. The value of time lies in measuring rate of change e.g. miles per hour or moles per second etc. However, the second is defined as the time taken for x cycles of a cesium atom. In essence what we're doing is comparing a given change to changes of some order of the repetitive change of a cesium atom. In other words we're actually comparing one change to another, our defined standard (the cesium atom).
So, time is nothing more than a short-hand for repetitive change/phenomena - in our world that of the cesium atom.
Therefore, time isn't real in the sense that an apple is. It isn't out there, existing as a real aspect of our universe. It's in here in our minds, a short-hand for repetitive change (cesium atom states) which we've decided as a standard to measure all other changes.
Time is an invention, not a discovery.
Your comments...
That said I need help on whether time is an invention or a discovery. Is time like a moon of a planet we've discovered or is it like latitudes and longitudes, invented to aid us in our understanding of the world?
A few things I understand about time:
1. [I]Change[/i] is essential for time. In a world without change time is meaningless. This I understood by imagining a world where we're immortal (changeless). To an immortal there's no difference between 1 second and 1000 years - time doesn't affect an immortal.
Similarly, imagine a world without change - no movement, no chemical reactions, absolute motionlessness (heat death of the universe?). In such a world, time would be meaningless and it'd lose its value as part of the space-time frame of reference.
2. Following through on 1 above, it isn't change per se that is necessary for time, specifically its measurement. We need a specific type of change viz. [I]cyclical/repetitive[/i] change for the notion of time to be useful. The day-night cycle, the year and down to the cyclical transitions of atoms - such repetitive phenomena are absolutely indispensable to time measurement.
Imagine that such cyclical phenomena were nonexistent in our universe. It'd be impossible to measure time and so, time would, again, be meaningless.
3. The value of time lies in measuring rate of change e.g. miles per hour or moles per second etc. However, the second is defined as the time taken for x cycles of a cesium atom. In essence what we're doing is comparing a given change to changes of some order of the repetitive change of a cesium atom. In other words we're actually comparing one change to another, our defined standard (the cesium atom).
So, time is nothing more than a short-hand for repetitive change/phenomena - in our world that of the cesium atom.
Therefore, time isn't real in the sense that an apple is. It isn't out there, existing as a real aspect of our universe. It's in here in our minds, a short-hand for repetitive change (cesium atom states) which we've decided as a standard to measure all other changes.
Time is an invention, not a discovery.
Your comments...
Comments (30)
Interesting point in the light of physics and math. Imagine a particle that moves according to the rule f(t) = 0. At every instant of time, it's at position 0. It never moves. Yet time exists as the independent variable.
What does this mean in real life? You park your car in the evening and note its position. The next morning, unless you are unlucky, your car is in the same position. In this situation it is meaningful that that time passed but your car's position did not change. It means your car did not get stolen. You have a positive emotional response to this lack of change. This shows that the lack of change over time is significant and meaningful in the world.
So I would dispute that change is essential to time. We often have the passage of time unaccompanied by change.
Now you might try to patch up your idea by saying that in my example, other variables changed. When you parked it was dark out but in the morning it was bright. That idea is problematic and needs to be fleshed out. Is it what you have in mind? Suppose we have a closed system and nothing changes. Can we say that time is meaningless inside this closed system? Perhaps. But outside the system, time is passing. So exactly how many variables to i need to ignore before I can say there's no change? Just because you can define a closed system doesn't mean that time stops. It just means that there was no change over a period of time. And that lack of change might be a source of comfort to you when you go out the next morning and find your car's still where you parked it.
Without measurement what is time?
Of course we would have concepts of before, now, after but such concepts can be parsed in terms of sequentiality just as we do with numbers 1,2, 3, 4,... Yes 2 comes after 1 and before 3 but there's no time involved.
Why not? Just employ fishfry's closed system analogy. The only difference, I suggest is to allow that time is passing within that system. There's a closed system, a world, in which nothing is changing but time is passing. The passing of time is not itself a change, and is occurring right within this world. The passing of time need not be measured to be occurring, and there might be an immeasurable amount of time which passes before a change occurs. We would ask how could change suddenly occur when there was no change before, and the cause of the change must come from outside the system. So, as fishfry points out, it is meaningful to talk about a system in which time is passing and no change is occurring.
What do you say to my example of a car staying in the same place overnight?
In your quote above, you ask me to consider a closed system. No change in temperature, position, acceleration, etc. Fine. But how many variables do I have to name? Maybe there's a universe with no change and there's some other universe where things change. Isn't the world of no change simply a list of variables you care about? My parked car is a world without change. Sure, if you toss in night versus day, then there's change. There is always some variable you can add in to introduce change. Closed systems are artificial. I don't think you're addressing my point.
How do we measure time? Don't we use repetitive/cyclical change like a pendulum or the cycles of an atom? I don't know if such cyclical phenomena are peculiar to this universe but without them time simply can't be measured. The idea of a space-time frame of reference is predicated on our ability to measure both (space and time). Without measurement time is meaningless don't you think?
I suggest that, in order to make sense of the owner's worry, the system should also include all local car thieves and vandals. They will be out and about stealing cars during the night. The car is there in the morning because they chose to focus their efforts on other vehicles.
So it seems that change is critical to this example. By contrast, what if we were to postulate a universe containing only a single car and nothing else - no owner, no planet, no thieves? We'd further have to assume that the car was made of special atoms that never underwent radioactive decay and never shifted position. In that case we could say that there was no change and hence no time either.
Quoting TheMadFool
???
To me it seems we're doing nothing more than comparing some type of change with a specific type of change (the repetitive regular kind).
X meters= distance covered in, say, Y cycles of a cesium atom. Y is then called 1 second and we get speed X meters per second. Time, then, looks to be simply a shorthand for cyclical change.
Another thing is that change, per se, doesn't require the concept of time. Change can be conceived of as simply a sequence of events. Sequentiality doesn't require time e.g. 2 comes before 3 but after 1 in the natural number sequence.
Similarly, consider the following event: ball x hits ball y and ball y hits ball z. We can put it in sequence like so:
1. Ball x hits ball y
2. Ball y hits ball z
So...
1. Change is necessary for time
2. Time is not necessary for change
Not sure it does. You could replace time with literally anything, or any number of things and get the same result. If f is a constant, it is not a function of time, or anything else for that matter.
Quoting fishfry
While you were absent, your car traveled an interval in spacetime approximately equal to -(ct)^2.
I see no reason to believe that a thing must be measurable to have real existence. Some philosophies distinguish between qualities and quantities, and although we reduce qualities to quantities in order to measure them, some philosophers argue that quality is more fundamental than quantity such that there are fundamental qualities which cannot be reduced to quantities.
Nor do I believe that without measurement something is meaningless. It is by seeing meaning in something that we develop the will to measure it. So meaning is prior to measurement, and it is very likely that human beings saw meaning in time prior to having the capacity to measure time. Therefore time without measurement is still meaningful.
Quoting andrewk
Change is not necessary within the system though. You posit change outside the system to demonstrate that time has passed. But this is only for demonstration purposes. If we remove the need for demonstration, which is the same as removing MadFools need for measurement, we can assume a system with time passing and no change occurring.
But as I said in my post, this system would remain as such for an eternity unless an activity comes from outside, to cause a change within. The system would have time passing, but no cause of change within it. If we want to introduce change such that the system does not remain eternally static, we have to get it from somewhere. Either way, we need an external system, either to demonstrate change, or to escape the static eternity.
Quoting TheMadFool
A sequence of events does not constitute change. Each event is a different object, and there is no change here, just a row of separate objects. To be called "change" you have to draw a connection between these events, and this is what the continuity of time does.
I thought of this too. The relational words ''before'', ''after'' require no time measurement. However these are, I think, a matter of sequentiality and sequentiality doesn't need time. For instance (sorry for being repetitive), 2 comes after 1 but before 3. See? We can make sense of change without involving time. The words ''before'' and ''after'' don't necessarily require a concept of time and these words are the only qualities of time. What do you think?
Quoting Metaphysician Undercover
Please read above.
I think that you are trying to make an argument by equivocation. In one sense, the word sequential refers to a succession or order in time, and in this sense, the words before and after are applicable. In another sense, the word sequential refers to a succession or order in space, and in this sense before and after are not applicable.
So you refer to an intermediary sense, a succession of numbers, and the assumption would be that numbers may be applied to either a temporal order, or a spatial order. The problem is, that when numbers are applied to a spatial order there is no proper use of before and after. Other than by convention, right is not before left, bottom is not before top. Likewise, in the application of numbers, 1 is not before 2, and 2 is not before 3. One is before the other in the act of counting, but that is a temporal succession.
In conclusion, the words "before" and "after" in the primary sense involve time, and in another sense they may refer to space. To argue by conflating these two is to argue by equivocation. Furthermore, your premise that before and after are the only qualities of time is false, because before and after are merely derived from, abstracted from, future and past. And if you were to replace "before" and "after" in your argument with "past" and "future", you'd have no argument.
Is stillness something we can even imagine or perceive?
To my mind 'constancy' or 'stillness' is never present in sensation nor in the imagination since they are always unstable, while 'sensed change' is synonymous with 'experience'.
This to me implies that our public meaning of "stillness" is merely a social directive to ignore the presence of change when it is considered to be unimportant for whatever purpose is at hand.
Therefore it seems somewhat strange as to why process ontologies and the relational notion of time haven't dominated philosophy from the very beginning.
I think you understand my point. Spatial sequences e.g. ball x hitting ball y and then ball y hitting ball z and so on can be understood without time being involved. I don't know the origin history of the words before, after and now but we can appropriate these words in discussing spatial sequence as I have done with the sequence of natural numbers 1, 2, 3, 4,...
We don't need time to discuss change in space. So, my point is that change, per se, isn't adequate for a well developed notion of time. We need a specific type of change which I referred to as cyclical change. Without the cycle of day-night, year, atomic cycles etc. we wouldn't be able to use the concept of time at all.
Quoting sime
Watch a movie. Hit pause.
I notice the screen is still moving as my eyes are wandering, and when I prevent them from moving my vision plays tricks.
Are you implying that I should [I]infer[/I] that the movie is still given my shakey and unstable observation of it, or that I should literally experience a state of stillness when I hit pause?
I think we do need time to discuss a change in space. A change in space requires movement, which requires time. Imagine points in space lined up like your number line, 1,2,3,4. Without time there is no change. In order for change to occur something has to move from 1 to 2, or otherwise, and this requires time.
The smallest unit of measure for time is Plank time, the 'distance' between two states of the universe wherein something changed. And that of course depends on the granularity of movement.
Does it seem possible that there's an infinite continuum rather than an atomic digital stepping of movement, such that at any resolution some smaller motion can be defined?
Extend your thought and everything is an invention, not a discovery.
We make sense of our surrounding reality with logic that has advanced to such level as mathematical as physics today is. Yet in my view that doesn't mean it's all just our invention. The universe would surely exist even without our small planet.
And to make logic out of the reality without the basic concept of time... and basically movement, would be interesting. So interesting, that likely it isn't just our invention.
All I'm saying is absolute rest can be imagined. I'm taking motion as it is typical of the concept of change: space-time frame of reference. We can imagine absolute rest.
Quoting Metaphysician Undercover
What I want to ask is: is time a mental or physical thing? To me, it looks like the former because it is possible to imagine a universe at absolute rest - no change at all - and in such a universe time is meaningless. So, if time seems real to us then time must be a peculiar characteristic of our universe and others like it.
Quoting AngleWyrm
I have a very superficial understanding of time and planck time. Notice, however, that all units of time are defined in terms of change. So, in a universe with no change there can be no time or, at least, time is immeasurable - both render time meaningless.
Quoting ssu
Can you have a read above. Thanks.
I agree with this, but I wouldn't class time as "mental" because that is ambiguous and confusing. "Mental" often implies that it is dependent on the human mind. Here, we want to say that time is not physical, but also not dependent on the human mind. So we have to have a category of non-physical, or immaterial things, which extends beyond the mental, to include time, and we also can place mental within that category. This means that what is proper to the human mind, as "mental", is not the limits of the non-physical, or immaterial.
You make a fine distinction. What do you think of stuff like longitudes and latitudes? Do you think that time falls in the same category?
Apply the concept of continuous motion to change.
Doesn't planck time preclude continuous change. The'way I understand planck time is that it's the fastest change possible. Since time is measured in terms of change we can't perceive time less than planck time.
And by observable phenomenon I mean that if it doesn't present any effect then for all intents and purposes it doesn't exist.
I don't quite understand the question. Longitude and latitude are totally arbitrary, like the number of degrees in a circle. The measurements of time are based in real activities, the day, the year, etc..
Quoting AngleWyrm
If I understand correctly, the Planck length is a limit imposed by the prevailing theories. If the theories are accurate, then the smallest unit of time predicted by those theories would also be accurate.
Longitudes and latitudes aren't real. They're mentally constructed frames of reference. So, is time like that? Did we invent time?
I think the difficulty is in our habit. We're raised with a strong sense of time and I think it becomes difficult to break free from that perception of time. All the things you said - "the day, the year, etc" are changes and cyclical ones to be specific. These are absolutely necessary for the notion of time to make sense. Imagine a world without cyclical changes - a world where nothing is repetitive, no pendulum swings, no atomic cycles and every change is irregular. In such a world it's impossible for us to measure time and the notion of time would be meaningless.
Time is real and allows change. Consider a change in state of a system, X->Y. Two states cannot lay on each other since the state of affair becomes ill-defined. This means that two state must lay on different points. This means that you need a variable to allow this to happen. There must however be a duration between two points otherwise the change will never takes place. The variable is therefore time.
Time versus cesium atom change OK .
The question is ,,time versus our brain changes to feel the time i.e. change versus change.I feel some confusing contradiction ,where is the actual change happened.
1.Change is necessary for time.
I don't know if this is a misconception but time is associated with change. Look at how the stoppage of time is portrayed in popular culture. In movies time halt is shown as motion/change slowing down and then stopping.
Imagine, as in the movies, everything stops moving/there is no change. If one is to stay true to the change-time paradigm, then time should stop or become nonexistent.
2. Time is not necessary for change. We can have change without the time. Changes can be viewed as sequences of events without time.
We don't have any sense to feel passage of time. Feeling passage of time is completely construct of brain activity. How it can be constructed. Just slow down the speed of subject.
Quoting TheMadFool
If it is so then all process should elapse in an instant.