Aristotle: Time Never Begins
In Physics 8, Aristotle offers the following argument against the idea that time can begin to exist:
If you feel like this is too long to read, and want a more summarized version, what Aristotle is basically saying is that time is change. So if the universe changes from "no-time" to "time", that in of itself is a temporal process, making it necessary that "no-time" is actually time. So time never begins.
Aristotle used this to forward the conclusion that the universe is eternal.
Do you think Aristotle's argument is sound or valid? Why or why not?
Further, how can there be any 'before' and 'after' without the existence of time? Or how can there be any time without the existence of motion? If, then, time is the number of motion or itself a kind of motion, it follows that, if there is always time, motion must also be eternal. But so far as time is concerned we see that all with one exception are in agreement in saying that it is uncreated: in fact, it is just this that enables Democritus to show that all things cannot have had a becoming: for time, he says, is uncreated. Plato alone asserts the creation of time, saying that it had a becoming together with the universe, the universe according to him having had a becoming. Now since time cannot exist and is unthinkable apart from the moment, and the moment a kind of middle-point, uniting as it does in itself both a beginning and an end, a beginning of future time and an end of past time, it follows that there must always be time: for the extremity of the last period of time that we take must be found in some moment, since time contains no point of contact for us except the moment. Therefore, since the moment is both a beginning and an end, there must always be time on both sides of it. But if this is true of time, it is evident that it must also be true of motion, time being a kind of affection of motion.
If you feel like this is too long to read, and want a more summarized version, what Aristotle is basically saying is that time is change. So if the universe changes from "no-time" to "time", that in of itself is a temporal process, making it necessary that "no-time" is actually time. So time never begins.
Aristotle used this to forward the conclusion that the universe is eternal.
Do you think Aristotle's argument is sound or valid? Why or why not?
Comments (58)
I voted no, I'm suspicious of this line:
The interval of real numbers (1,2) has 'no number on the right', as it does not contain its least upper bound ( 2 ), you'd need to look 'outside of it' (in the real numbers themselves) to get that. So in that interval you get a length (moment = length of time?) with no first largest time point within it... The only way to give that interval a maximum is to bring the real numbers themselves (an underlying continuum) into the picture. In effect, this conjures the eternity of time 'the moment' is embedded in into the moment, without showing that such an operation is valid.
To me it looks like three different duration concepts being conflated with each other - bounded intervals, intervals which don't contain their end, and the underlying set that end exists in.
I doubt these concepts are as Aristotle intended them to be interpreted, though. Maybe his argument is valid when understood closer to his own terms.
To be completely honest, I am not sure if I agree or disagree. By "time never beginning", I am interpreting him to be positing an actual infinite, which, in that case, I would disagree. However, if he is stating that time is potentially infinite, as in change (and subsequently causality) is potentially infinite, then I agree. I haven't read up enough of on Aristotle, I do admit. Maybe you know which he is referring to? Likewise, I interpret "eternal" as "unchanging with respect to any notion of time/change", which is also (I would say) subjected to my same dilemma as previously depicted (potentially eternal or actually eternal?).
The beginning of unidirectional time is easily set in motion by the virtuality going forward and backward in time. From this central virtuality, matter and time can be created over and over again. So time has infinite beginnings. After present time ends at infinity, a new time starts. Aristotle was right about one thing though. His eternal circular motion resembles the fluctuating time constituted by the virtuality at the source.
This bothers me. Time count begins when something changes. A void with no space-time has no time. Time starts at the mark of a change. "Universe and no-time" don't go together.
Yep. Why? Refer to Zeno's paradox(es): Achilles, forget about catching up with the tortoise, couldn't even start (running [clock])! Time (is an illusion)? :chin:
I agree with this. I also challenge the claim that motion defines time. It does not. Motion makes time measurable, but it does not define it. Time exists outside of motion.
What Aristotle proved is not that time exists forever, but that motion has existed forever. He fails to see the power and the finding of his own proof.
This argument fails if time is assume to go forward only. If it goes up and down, as before the unidirectional inflation, spawning the real from the virtual, time can have a beginning. As it must have a beginning. If this weren't the case, we would observe chaos only.
Time can't exist without space. Your conception of time makes you think it can go one direction only. But it can go up and down. It can oscillate. In fact, the vacuum is oscillating in time.
Can you perceive of a lifeform who experiences existence, not as a continuum?
A lifeform which 'hops' (@EugeneW) between the linear existence of other lifeforms such as us.
It moves between linear consciousnesses, not at will but based on the laws of physics of its own multidimensional space/multidimensional time. It learns from each encounter with linear time corporeal lifeform like us and it also experiences 'periods of continuum' within its own spatial dimensions, where it can interact with its own kind and experience and build within its own world, before it 'phase shifts' again.
Did I just create this lifeform in a mimicry of the god posit by thinking about its existence or am I just thinking like an arrogant theist?
What if there is more to the universe than there appears to be? What if there is more than one universe?
Time cannot exist without change.
In other words things change relative to each other. The relationship between one change and another is time.
But only in space they can change.
In other words, things can oscillate in time, like virtual particles in the vacuum, or have a timelike direction, like virtual particles turned real.
You can tell this is a good topic by all the thoughtful answers you got. Not a smarty pants in the bunch. I like quoted text a lot. Is it convincing? Yes, actually it is. Does it convince me? Well.... I'm with @Bob Ross "To be completely honest, I am not sure if I agree or disagree." So, I agree that I can't decide if I agree or not.
Quoting Tom Storm
I agree with this, but I also find the argument convincing. Does that mean that I've violated the Law of Noncontradiction? So..what are you going to do about it?
Quoting fdrake
Aristotle says that time must be eternal, not that sequences of numbers must be. Numbers are ideas. while time is real. Except that it isn't. See above.
Quoting L'éléphant
Agree.
Quoting god must be atheist
Disagree, although I might say "change" instead of "motion."
Quoting Harry Hindu
Quoting Harry Hindu
Agree.
This is fun.
But he is well aware of the danger of leaving such questions open. Others will rush in to proclaim the "truth".
As Al-Farabi notes:
(Harmonization) Quoted in David Bolotin's "Approach to Aristotle’s Physics".
The phrase "Aristotle's argument is correct" is incorrect.
A sound argument has a different meaning to a valid argument.
There should be four questions within the poll:
Aristotle's argument is sound
Aristotle's argument is not sound
Aristotle's argument is valid
Aristotle's argument is not valid
Aristotle's argument is valid but not sound.
His premise is false - "Now since time cannot exist and is unthinkable apart from the moment, and the moment a kind of middle-point, uniting as it does in itself both a beginning and an end, a beginning of future time and an end of past time"
His reasoning is correct
His conclusion is false - "it follows that there must always be time"
There is a problem with Aristotle's premise
We can only experience the moment we are in. We cannot experience at this moment either the moment before this moment or the moment after this moment. Therefore, we can never directly experience either the past or the future.
Therefore, as we can never directly experience either the past or the future, we can never have first hand knowledge of the meaning of the terms time, past, present, eternal, creation or motion.
Therefore, Aristotle's conclusion that time and motion are eternal can only ever be an interesting hypothesis.
I think it's valid with the premise that time accords with the way we usually imagine it.
But there are other ways to imagine it and maybe some ways we haven't considered yet (as a species). So the conclusion may be wrong.
The first claim is:
1. For any point in time t, there exists a time t1 such that t1 is before t and there exists a time t2 such that t2 is after t.
The second claim is:
2. If time began, then 1. is false.
Why should we accept 1? If 1 is true it follows that time did not have a beginning. Conversely, if time did have a beginning, then 1 is false. But since the question at issue is whether time did have a beginning, then the argument begs the question.
There is also the problem 180 pointed out. We can talk about processes having a beginning and an end in time. But it's doubtful whether it is coherent to talk about time itself having or not having a beginning or end in time.
However, Aristotle was not liable to make simple mistakes in reasoning. His writings are condensed, sometimes almost lecture notes. There may be more to this. For example:
3. If 1 is false, then we cannot think or speak coherently about time. ("unthinkable")
4. We are now communicating with each other coherently about time.
So 1 is necessarily true.
The necessity in question is that our idea of time falls apart if we try to think of a time before which there was no time. Aristotle may be closer to 180's objection than it seems.
How can the clock tick without motion?
Let it be that time is constituted by collective motions of particles. Let is also be that time can be understood in terms of before-and-after processes but that time itself is not one of those processes. And let it be that time is an affect of motion - that motion is what makes time what we understand it to be. It seems to me that EugeneW, 180 Proof and Aristotle are not so far apart after all.
Quoting EugeneW
True enough. You can't patronise a person for being alcoholically incompetent and at the same time hold them responsible for their actions. But that's another thread.
I think thermodynamic time Is constituted the irreversible processes. You can quantify these processes by putting a clock besides them. A clock is an ideal process though. Only in our minds a truly periodic motion (with constant period time) exists. And of this clock, say a pendulum, you can't say it goes forwards or backwards in time. That's exactly the case with virtual particles. They fluctuate in time. When the circumstances are right, this fluctuation is turned into unidirectional real-particle time. Everywhere in empty space, virtual particles fluctuate in time. Before inflation, virtual particles were the only players around. So all what was present was a kind of virtual real ideal clock, without yet processes to measure time of. The events of a faraway universe accelerating towards infinity were the trigger of thermodynamic time. Not sure what 180 says about this. @180 Proof, what's your idea?
It is the height of human hubris and folly to think that what is, was, and will be are limited by what we can think or comprehend or can give an account of.
Thermodynamic time has a beginning by necessity. Forward time is determined by collective particle motions evolving towards higher entropy. If time had no beginning it logically follows that the current state of the universe was one of chaos simple and pure. That, we observe not, fellophilo's.
So, time had a beginning. But how can it begin without a kick? The modern-day physical ideas offer a solution. Before thermodynamic arrow of time shot, the bow was tense. The arrow consisted of virtual particles, a much debated idea in modern physics, actually close to Aristotle's idea of eternal circular motion. All basic virtual particles oscillate in time. Or better, they constitute
oscillating time. Real particles in motion interact by means of these eternal omnipresent virtual particles, and these constitute the time we're used to.
:eyes:
Quoting 180 Proof
No asymmetric changes, no clocks. :point:
I hate to say it, let alone admit it... but this is a very... eeeh... a very... go... eeeh, damn... go... go... go..., excuse the stutter, booze. I sing it: this is a very gooood idea! Realistic even. Quoting 180 Proof
Quoting 180 Proof
:down: ,eeeehh... :point: ,eeeeh :up:
You got a point! I merely add that the pre-big-bang-inflation symmetric time was not measurable indeed because it actually was a clock.
To think what was, is, and will be is limited is a conjecture which can be experimentally verified. All current evidence points at an unlimited succession of time intervals [0,inf.). Every ending of an interval kicks the virtual, omnipresent, eternally fluctuating basis into reality, thereby creating a new [0,inf.) interval of time. In the by now famous words of @butimfeeling2022: "over and over again".
In fact, we have exactly the same idea, but differently worded. Maybe I should look for new ideas... :kiss:
Quoting EugeneW
:up: The passage from Aristotle that you brought in is very interesting. It's a very long time I have not read Aristotles --since school maybe-- and I enjoyed it!
Quoting Kuro
This is what I also believe and often mention in discussions. More specifically, that time is our measurement of and reference to change, including movement in space.
Quoting Kuro
Well, this could be a very good point if its description had no some weaknesses:
1) The universe cannot change from "no-time" to "time". but from non-existence to existence.
2) A "process" is a series of actions or steps taken in order to achieve a particular end. So what we are talking here is an event. (Re: Hawking's singularity)
3) For something to change, it must already exist. So, we cannot talk about change, transition or whatever from non-existence to existence.
4) The element of temporariness could well be missing, since it is disputable and not necessary to prove that "time never begins".
So, the main argument for the thesis that time never begun or it is eternal, can put it in this way: "If we assume time's existence from non-existence, i.e. that it has been created from nothing, there should be a point at which this has happened. But this "point" can only refer to time. This creates a " circularity" or impossibility.
A second way is this: Something cannot be created from nothing. There is always a source of creation, a cause that creates something. And that, cannot be "nothing".
There are certainly a lot of ways to prove this thesis.
I don't see an exception. The process of creation is temporal by definition, so while I have no problem with time being bounded, it seem a contradiction to apply the concept of creation or destruction to time. There are valid solutions to Einstein's field equations with bounded time, such as white and black holes.
I cannot know time by acquaintance, as "We can only experience the moment we are in. We cannot experience at this moment either the moment before this moment or the moment after this moment. Therefore, we can never directly experience either the past or the future."
I can only know time by description.
As Aristotle, as well as everyone else, only knows time by description and not acquaintance, his conclusion that time is eternal and without beginning must remain a hypothesis, interesting, but still an unprovable hypothesis.
But it's Saturday 19[sup]th[/sup] March, 2022.
Take that, Pembroke scholars!
The conclusion is not so simple, because the argument you presented must be taken within the proper context. Notice that the paragraph closes with a conditional statement: "But if this is true of time, it is evident that it must also be true of motion, time being a kind of affection of motion." So he then proceeds to question the idea of eternal motion. He concludes that there must be a first mover which is not itself moved, and this denies the possibility of eternal motion. The unmoved mover implies that there is something outside of motion and time, so "eternal" is given that meaning, outside of time, and infinite motion, as well as infinite time, are rendered as incoherent.
OK player. Nah, you ain't funny yet.
Haha! You read it too?
He writes at the end of section 5 of Physics Book 8 - "From what has been said, then, it is evident that that which primarily imparts motion is unmoved: for, whether the series is closed at once by that which is in motion but moved by something else deriving its motion directly from the first unmoved, or whether the motion is derived from what is in motion but moves itself and stops its own motion, on both suppositions we have the result that in all cases of things being in motion that which primarily imparts motion is unmoved."
The question is, are his premises sound and his his argument valid ?
As @Metaphysician Undercover pointed out, the paragraph in the OP has been taken out of context.
Aristotle's inference of a spiritual rather than physical explanation for an "unmoving mover" may be brought down to earth.
1) Imagine a rock travelling through space at 10,000 km/hour. In Aristotle's terms, where is the unmoving mover that keeps the rock travelling forwards at a constant speed ? How to explain the Law of Conservation of Energy, whereby the kinetic energy of the rock is maintained ?
However, motion is relative, and we may consider the rock as stationary within a moving environment. In this case, the rock being stationary, no unmoving mover is needed, and the existence of an unmoving mover is not required.
2) Imagine the same rock in distant space. Movement is not a property of a single body, but is a property that emerges when more than one body are in near location, whether the gravitational force between the moon and the Earth or the magnetic attraction between two magnets. If another body approaches this particular rock, the paths of the bodies will be changed by a gravitational attraction.
In this case, the primary mover is gravity, which may be understood as a curve in space, and in Aristotle's terms, an unmoving mover
In summary, in both cases, it is not necessary to consider a mysterious entity outside the known universe, in that the "mover" can be explained as a physical state of affairs within current time and space.
But what brought space and time into being?
Aristotle in Physics Book 8 claims that motion is everlasting, has no beginning and will have no end.
And yet he discusses the "unmoved mover", where "the first movement is moved but not by anything else, it must be moved by itself"
Although his "unmoved mover" has been identified with a spiritual explanation, Aristotle in Physics Book 8 doesn't explain its nature.
Today, this "unmoved mover" can be explained in more scientific terms, without the need to address what brought space and time into existence.
I think virtual particles on a central singularity are the first unmoved mover, in the scientific sense. They don't move unidirectional in time and resemble the eternal circular motion, which has no direction in time too. They fluctuate up and down in time to be kicked forward and realized by a surrounding giving a sign. When inflated into real, their evolution backfired to the singularity, the virtual source, to bring on a new inflation. But where did this infinite cycle come from?
Space changes too.
Quoting EugeneW
I don't know what "in time" means. Oscillations are changes. How fast (how much time) does one thing oscillate? You have to compare it to another change to find out. Time is the comparison of change. The direction of some change only manifests itself when comparing the change to another change.
Yes. And both the changing of the metric and real particles moving asymmetrically (thermodynamically, irreversibly) constitute time. Thermodynamic time. The virtual motion of virtual particles on the pre-inflationary era constitutes the non-directional, fluctuating time. A perfect pendulum, an eternal circular motion of which you can't say it's going back or forth. It's going to and fro, waiting for the right circumstances to kickstart it in one direction. Or better, two. The universe and a mirror version. But the wait is timeless in the sense of having no direction yet. The big mystery is why it all doesn't have the opposite direction. And another mystery is who brought this eternal sequence of big bangs, with two ensuing universes, into existence.
The period time is a Planck time. The amplitude a Planck length. That's the maximum length the virtual particles had to oscillate. They don't oscillate in time but constitute time themselves. If you hold a virtual clock beside it though, you would see the hand of that clock go back and forth.
Ouroboros? I eat and I eat and I eat and I eat...myself.
If we would consider the omnipresent virtual particle fields residing in the vacuum of nature the eternal unmoved prime mover, we would still be left with the question where that came from.
Aristotle
Aristotle's answer would be that the universe is eternal having never come into existence. His is not the God of Genesis who created the world out of nothing.
But the universe is in eternal motion, and for Aristotle the universe needs a cause for its continuing existence and motion, and that cause is a God, outside the world, changeless and immaterial.
Aristotle's theology is set out in books VII and VIII of Physics and book XII of Metaphysics
Such a God is an "unmoved mover", not responsible not for the creation of the universe, as for Aristotle the universe is eternal, but responsible in a non-physical way for the continuing motion within the universe.
Modern interpretation
Aristotle's belief that the universe is eternal seems reasonable. If a thing exists, as it is almost unimaginable that at a later moment in time it could disappear into absolute nothingness, it is also almost unimaginable then at an earlier moment in time it could have appeared from absolute nothingness.
Gravity may also be considered an "unmoved mover", whether considered as a force or curvature in space-time. A "mover" with infinite range where all things are attracted to one another, and "unmoved" in that whether a force or a curvature in space-time can cause motion without being in motion itself.
Right. So change constitutes time. Measuring time involves comparing one change with another, like the change of a virtual particle's state vs the change of a real particle's state. Which change you choose to measure by is arbitrary, just as measuring length and mass.
Quoting EugeneW
Again, we're simply talking about comparing one change with another when measuring time. But you're not measuring time. You're measuring change. Just as length is a comparison of two objects in one dimension, time is the comparison of change in two objects (in another dimension).
The clock measuring time has itself no direction in time. Virtual particles are the incarnation of the ideal clock. They go back and forth in time. In a Feynman diagram they are represented by a circle without legs, a vacuum bubble. This virtual clock is eternally present in spacetime.
But I would certainly agree with Aristotle that either time always existed or there is some supernatural explanation for it's becoming.
Here's how I understand the argument.
You can conceive of a moment as a boundary between the past relative to that moment, and the future relative to that moment. Geometrically, this would be like picking a point on a line -- let's make it the usual line from school and call that point "0" -- and using that point to define a ray [math](-\infty,\ \ 0][/math], and a ray [math][0,\ \ \infty)[/math].
So that's a moment, "a beginning of future time and an end of past time."
*** Edit ***
Except of course we're not entitled to put it quite like this, and Aristotle doesn't.
All we need for Aristotle's version is for there to be no first or last moment, that is, all of time just has to be unbounded: [math](first,\ \ 0][/math], and a ray [math][0,\ \ last)[/math].
There's still infinities all over the place, but we don't get arbitrary points in time like 100 trillion years ago.
******
Aristotle also says that the moment is our only "point of contact" with time, that time is unthinkable "apart from the moment." So any point in time we can imagine must be a moment. That is, he's arguing for something like the uniformity of time: every moment is like this, a boundary between past and future, and conceiving of time is, for us, conceiving of such moments.
Well then it's perfectly clear that time can't have a beginning or an end. If it had a beginning, there would be a moment that was unlike every other moment, that was only the beginning of a future and not the end of a past. Likewise for the end of time. And a moment unlike every other moment is not a moment at all, and cannot be part of our conception of time.
So far as it goes, the argument seems clearly right. (I didn't quite get it until I thought of "our only point of contact" in a sort of Flatland way -- imagine that all you know of the line is what you know as a point on it, take its point of view, and to be such a point is to see a neverending expanse of line to either side of you.) Indeed, no matter what cosmology tells us, we cannot help thinking it makes sense to ask what happened before the big bang, or what would happen after the big crunch. Time seems to us to go on uniformly from an infinitely distant past to an infinitely distant future.
In modern terms, it's a bit like taking the tripartite structure of the A-series, and arranging such moments as a B-series. Aristotle doesn't speak here directly of a moment changing from future to present to past, but he insists that a moment is a boundary between a past and a future. You can line up such boundaries in B-series fashion, but that doesn't change them into simple points that have only (tenseless) relations of before and after to other points; they each define two infinite sets of other points, all of which also define two infinite sets of other points, and each and every such point is a boundary between two such sets, between a past and a future.
*** Edit***
And then this is interestingly wrong, because we can mistake being unbounded for being infinite in magnitude. It's still true there's no first moment of time, and infinitely many before any given moment, but that doesn't mean they add up to an infinite amount of past time.
:up: Correctamundo!
Look forwards and time kinda needs to have a beginning.
Look backwards and time with a beginning is ridiculous.
Similarly, philosophers in Flatland will conclude that there can be no third dimension. Every point in their experience has only a left and right, forward and back. A point with additional directions would be outside of their experience, and so not a point at all.
Time began at _____. :chin:
As you can see a beginning presupposes time i.e. if you wanna say time began, time must already exist. 180 Proof said the same thing.