Circular Time Revisited
This is an argument that we will experience identical lives over and over again. I am by no means fully convinced by my own argument, but I do think it’s an intriguing possibility that is worth discussing.
First off we must briefly demonstrate that time has a start. There are many arguments to do this, I will use the simplest:
1. Assume time has no start
2. Then there is no first moment
3. If there is no nth moment there is no nth+1 moment
4. But we have moments (contradiction)
5. So time must have a start
A dimension can have an open or closed topology (IE a line or a circle). There are no other options, so without considering any evidence (that is done below), there appears to be a 50% chance that time is circular.
We then introduce an axiom of Aristotle’s: before each moment there must be another moment. Now our model of time as a finite length line does not work; there is no moment before the start of time. So we bend the line around into a circle. Then we have a start of time and Aristotle’s axiom is satisfied.
Of course such a possibility as circular time is in violent disagreement with presentism, so we must briefly show that presentism is probably false:
1. Time has a start (see opening argument)
2. Assume ‘only now’ exists (presentism)
3. So before the start of time there was nothing
4. But that would require creation ex nilhilo (absurdity)
5. So [2] must be wrong - IE more than ‘only now’ exists
Also I’d point to Special Relativity - examples such as Einstein’s train and the Andromeda paradox clearly show that presentism cannot be correct. The rest of the discussion below therefore assumes that something like 4D spacetime (eternalism) is the correct model of time.
Now it is too difficult to imagine 4D spacetime, so we drop a spacial dimension and imagine 3D space-time instead. Then we can imagine the whole of spacetime as a 3D object. It can have only one of two topologies:
1. Open. So like a cone. The pointy end is the Big Bang and the cone widens as the universe expands
2. Closed. So like a torus. This possibility is expanded on below
We then consider the question ‘Where in spacetime is it possible to get all the matter and energy required for the Big Bang?’
The only answer is the Big Crunch - that has precisely the correct amount of matter and energy required for the Big Bang. So returning to the picture of the torus as spacetime, it is thin at one point where the Big Bang / Big Crunch occur. And it is fat at the opposing point, where the maximum spacial expansion of the universe occurs.
We then need to consult General Relativity. Einstein says that matter warps spacetime. We have plenty of empirical evidence that this is so (eg search for gravity lens on google images for a visual demonstration of matter warping spacetime).
There would be a tremendous amount of matter around at the Big Bang / Big Crunch so it would warp spacetime tremendously - right around into a circle maybe. This is referred to as a Closed Timeline Curve (CTC) - a class of solutions to GR (see https://en.wikipedia.org/wiki/Closed_timelike_curve). On a CTC, one always travels forward in time (backward time travel is forbidden) but you arrives back at the point in spacetime where you started out.
A final argument: I believe that the universe is a creation, implying a creator(s). So putting our God shoes on for a moment, God is bored and wants a toy. He decides to create a universe that is fit for intelligent life. He would like to include the ‘life after death’ feature if possible. He considers heaven and hell and decides it would be tough to implement. Want he wants is a Occam’s Razor solution to life after death. What is the simplest model of a universe that supports life after death? If our God is an astrophysicist and knows all about CTCs, then maybe he would create the universe such that the whole thing is a CTC - that is the simplest solution.
Your thoughts?
First off we must briefly demonstrate that time has a start. There are many arguments to do this, I will use the simplest:
1. Assume time has no start
2. Then there is no first moment
3. If there is no nth moment there is no nth+1 moment
4. But we have moments (contradiction)
5. So time must have a start
A dimension can have an open or closed topology (IE a line or a circle). There are no other options, so without considering any evidence (that is done below), there appears to be a 50% chance that time is circular.
We then introduce an axiom of Aristotle’s: before each moment there must be another moment. Now our model of time as a finite length line does not work; there is no moment before the start of time. So we bend the line around into a circle. Then we have a start of time and Aristotle’s axiom is satisfied.
Of course such a possibility as circular time is in violent disagreement with presentism, so we must briefly show that presentism is probably false:
1. Time has a start (see opening argument)
2. Assume ‘only now’ exists (presentism)
3. So before the start of time there was nothing
4. But that would require creation ex nilhilo (absurdity)
5. So [2] must be wrong - IE more than ‘only now’ exists
Also I’d point to Special Relativity - examples such as Einstein’s train and the Andromeda paradox clearly show that presentism cannot be correct. The rest of the discussion below therefore assumes that something like 4D spacetime (eternalism) is the correct model of time.
Now it is too difficult to imagine 4D spacetime, so we drop a spacial dimension and imagine 3D space-time instead. Then we can imagine the whole of spacetime as a 3D object. It can have only one of two topologies:
1. Open. So like a cone. The pointy end is the Big Bang and the cone widens as the universe expands
2. Closed. So like a torus. This possibility is expanded on below
We then consider the question ‘Where in spacetime is it possible to get all the matter and energy required for the Big Bang?’
The only answer is the Big Crunch - that has precisely the correct amount of matter and energy required for the Big Bang. So returning to the picture of the torus as spacetime, it is thin at one point where the Big Bang / Big Crunch occur. And it is fat at the opposing point, where the maximum spacial expansion of the universe occurs.
We then need to consult General Relativity. Einstein says that matter warps spacetime. We have plenty of empirical evidence that this is so (eg search for gravity lens on google images for a visual demonstration of matter warping spacetime).
There would be a tremendous amount of matter around at the Big Bang / Big Crunch so it would warp spacetime tremendously - right around into a circle maybe. This is referred to as a Closed Timeline Curve (CTC) - a class of solutions to GR (see https://en.wikipedia.org/wiki/Closed_timelike_curve). On a CTC, one always travels forward in time (backward time travel is forbidden) but you arrives back at the point in spacetime where you started out.
A final argument: I believe that the universe is a creation, implying a creator(s). So putting our God shoes on for a moment, God is bored and wants a toy. He decides to create a universe that is fit for intelligent life. He would like to include the ‘life after death’ feature if possible. He considers heaven and hell and decides it would be tough to implement. Want he wants is a Occam’s Razor solution to life after death. What is the simplest model of a universe that supports life after death? If our God is an astrophysicist and knows all about CTCs, then maybe he would create the universe such that the whole thing is a CTC - that is the simplest solution.
Your thoughts?
Comments (72)
Also the proposal seems incoherent. I cannot live 'this' life again, I can at best live another life that is indistinguishable from it. Yet on your proposal that is not what happens, yes? On your proposal this present moment will be the present moment again, in the future. That's incoherent - the present can't be present again in the future, for that would make this present moment both present and future, yet these are manifestly incompatible properties.
I don't want to do that. I want the opportunity to do better in the next life. It would be awful to live the same life over and over.
This by the way is an objection to the idea of uploading your mind to a computer (something I don't personally believe will ever happen). Any computer is finite. You would eventually start duplicating states. You would in fact be condemned to live the same life, over and over. You would beg your technicians to stop your program.
In the future, being uploaded to a computer and forced to live the same life, over and over and over forever, will be a punishment administered to the worst offenders. Being condemned to live forever would be literally a fate worse than death. There's a sci-fi story in there if someone wants to write it.
For that matter see the Anne Rice vampire novels. At first eternal life seems like a gift. In the end it turns into a nihilistic horror.
Eternal Return - Friedrich Nietzsche
The One-Way Dead-End and/or The Eternal Return:
I don't want to close down this question, but rather contribute an appropriate level of humility to it. For example, perhaps any kind of physical reality as where we find ourselves, including any logic, or metaphysics, is an artificial construct for some unknown (to us) purpose, for an unknown entity.
Also God might be this unknown entity, which isn't the actual creator of the universe. So can we even address God, or the universe, or understand what they are, or if they are real.
I find this really iffy. I think 3 is straight up false though. If time ends somehow there will be an nth moment without an (n+1)th moment. Not only that but I find the use of "nth moment" problematic. There can be a moment but no nth moment. As in there can be a moment in time, but one that we cannot label with any number n, namely, if time is circular. If time is circular you can't label any point on it n without that labeling being arbitrary. However that doesn't actually mean there is no moments. You conflate not being able to count moments with them not existing at all
How though? It's not like your memories will transfer between lives. You won't notice you're living the same life for the 20 billionth time. If your memories trasferred then you're by definition living different lives
It is possible to prove God is benevolent but I don't believe one can prove him omni-benevolence?
So assuming God is just benevolent, maybe he calculates that society tends towards perfection as time goes on, so circular time would be just great for the majority of people (though it might not be 100% great for us as our society still needs to evolve further).
Heaven and hell is possible I guess (instead of circular time), but I feel it is more difficult to implement.
Quoting Bartricks
I'm thinking of time as the eternalist moving spotlight view. So imagine the a spotlight rotating around the torus/circle of time. Wherever the spotlight shines is 'now'. So we have one life but experience it multiple times.
You would not remember anything so it will feel like living a whole new life.
Quoting Punshhh
Great minds think alike they say. I'm not saying we have minds as great as God, I speculating that all intelligent beings would have a similar sort of mind so that it would, in a limited sense, be possible to read the mind of God.
All point [3] says is 'If there is no nth moment there is no nth+1 moment'. In the case of time ending, then there is an nth moment, so argument [3] does not apply to that scenario.
Quoting khaled
I am thinking of the moving spotlight view of time. A spotlight rotates around the torus/circle of time, wherever the light falls is 'now'. So the spotlight would have had to start somewhere, no doubt at the Big Bang. That would be moment zero and the nth moment can be calculated from that basis.
Ah, that's a good feature. Solves the problem.
Quoting khaled
Ok! No memory between lives. I get it.
Quoting Devans99
4. so we have no such numbering of such moments
One more proof time has a start: perpetual motion is impossible so time has a start.
That is about 5 proofs I've given that time has a start Vs 0 proofs you have given that time has no start.
No, that only applies to distinct instants, not indefinite moments. In any case, what is the first real or rational number after zero? It straightforwardly begs the question to insist that only the natural numbers can be used here, because by definition they have a first member.
If the width of 'now' is zero, time never flows. 'now' cannot be infinitesimal width because actual infinity is metaphysically and logically impossible (see https://thephilosophyforum.com/discussion/7379/infinite-bananas/p1) .
So 'now' must have a finite, non-zero length which we can call a moment. So it is valid to number the moments since the start of time.
The proof is actually all intelligent beings must be benevolent:
1. You are an evil person. You meet a good person. You are punished
2. You are an evil person. You meet a evil person. You are punished
3. You are an good person. You meet a evil person. You are punished
4. You are an good person. You meet a good person. You are rewarded
So anything (including humans, AI, aliens, gods) intelligent enough to work out the above would see that the only satisfactory outcome comes through being good.
Agreed.
Quoting Devans99
As usual, this wrongly confuses "infinitesimal" with "actual infinity." The proper mathematical definition of "infinitesimal" in this context is having length that is non-zero, but shorter than any assignable value relative to an arbitrary unit interval. The proper phenomenological definition of "moment" in this context is a continuous span of time with duration too short for any sensible change to take place.
Quoting Devans99
What is this alleged finite, non-zero duration of "now"? On what rational principle can we go about determining it, rather than just arbitrarily defining it?
Quoting Devans99
No, "indefinite" quite literally means "not defined" (by anything). We directly perceive the continuous flow of time within the present moment, and then abstract distinct instants that stand in the relations of preceding (earlier than) and following (later than).
No number can have a length greater than zero and less than all reals IMO. So it must be the imaginary construct of 1/? that you refer to? As you know, I think ? is a logical impossibility so therefore 1/? is not possible either.
Quoting aletheist
How do we measure time? We could use light clocks. So that 'now' corresponds to some minute distance travelled by light (the Planck length maybe). So now must be finite and non-zero for the light beam to move and for time to flow.
It is worth noting that someday we maybe able to prove empirically that space/time are discrete. We will never, ever be able to empirically prove they are continuous.
Quoting aletheist
But in the second of time that started two seconds ago and finished a second ago, I experienced all possible instances of time as distinct moments - I actualised each moment. So I'd argue that belief in time as a continuum is equivalent to a believe in actual infinity (which is impossible logically IMO). Likewise, when I move my hand, I actualise all possible intermediate positions.
Thank you Tim.
The creator of the universe (if you believe there is one) must be very smart, easily smart enough to work out my little rap on Pascal's Wager. So I believe God must be benevolent.
God cannot be sure he is the only god. Its impossible to prove that something does not exist. There could be a more powerful god out there somewhere in some alternative reality not known by our God. So all gods are bound by the argument I gave (as we are).
No number can have a length at all. In any case, we are not talking about numbers, we are talking about time.
Quoting Devans99
No, and I have stated this plainly before. I provided the relevant definitions, so please stop trying to impose others.
Quoting Devans99
Irrelevant; how we measure time does not dictate the real nature of time.
Quoting Devans99
We cannot "prove" anything empirically, only gather evidence. What kinds of experiments could somehow demonstrate that time is discrete?
Quoting Devans99
Again, we directly perceive the continuity of time. What more conclusive empirical evidence could there be?
Quoting Devans99
No, we already agreed that "now" is not a durationless instant, and all we ever experience is "now"; so we never experience any distinct moments, let alone an actual infinity of them.
Quoting Devans99
We had that conversation already.
Quoting aletheist
Positions are artificial creations for describing motion, not real constituents of the motion itself. Likewise for instants and any "distinct moments" that they allegedly define.
In our minds we can treat numbers as labels with no length. But we are talking about time; that is in reality, something must have greater than zero width to exist. So a moment of time must have a non-zero width
Quoting aletheist
The only other definition of an infinitesimal I'm aware of is a number x>0 such that x^2=0. Also nonsensical in my opinion.
Quoting aletheist
Good question, I am not sure. We could perhaps discover space is discrete through the observation of the movement of particles. Maybe we could infer from that spacetime is discrete.
I always wondered about e=mc^2. IE e/m=c^2. Energy and matter are discrete quantities so that means c^2 is discrete. But c is distance/time, so are these also discrete? My physics sucks... can't be that simple!
Quoting aletheist
You are claiming there are moments in the last second I did not experience. But I experienced all moments - all actualised. Unless you are claiming that humans are discrete and time is continuous?
But say we had greater perception. We'd experience more distinct 'nows'. If we had greater perception still, we'd experience even more distinct 'nows'. If we had infinite perception, we'd experience infinite nows... an actual infinity.
Quoting aletheist
I disagree, continuous motion by definition marks out a greater than any number of intermediate positions. If you say it marks out a fixed number of positions, then that means space is discrete. I do not see how it can be an indeterminate number of intermediate positions - every possible position the hand occupies must be a distinct position and there must be a greater than any number of such distinct positions if space is a continuum.
But 'God' with a capital G refers to a being who is omnipotent, omniscient and omnibenevolent.
But anyway, if you think the god is just benevolent, it is still unclear why he'd make us live the same lives over and over.
More fundamentally, however, your view is incoherent. As I said, if you're proposing cycles in time, then the present moment is also a future moment. I mean, how can you deny that? It is in the future, and it is present, and it is past. It is all three. Right now. Right now, it is all three. Yet they contradict. if an event if present, it is not also future and past. If it is past, it is not also present and future.
An analysis of time that does not respect the incompatibility of past, present and future is not really an analysis of time at all, but something else.
For an analogy: if I watch a film multiple times, I am not watching it for the first time lots of times - that doesn't make sense. I am simply watching it again and again. The idea that I could watch the film 'for the first time' numerous times is equivalent in incoherence to your proposal that we live our lives over and over. It doesn't make sense. You can watch a film for the first time once and once alone. And you can live your life once, and once alone. The present moment is never going to be present again. The future moments will never be future again. And the past will only ever be increasingly past.
I imagine a moving spotlight rotating around the circle of time. Where the light shines, that is 'now'. So all moments have a real existence but only one is present at any time.
Quoting Bartricks
I'm suggesting it could be that you have one life and experience it multiple times. So each time you experience it, you never remember the previous time, so it feels like the first time. If you remembered the previous experience, it would not be the same life.
That doesn't make sense - you're invoking time. You're getting too caught up in a metaphor. If time is cyclical, then the present moment is also a future moment and a past moment. It is not 'presently a present moment'. That's to invoke the idea of a fixed present - the very idea your theory denies is true!
So again, on your view 'now' is also 'future' and 'past'. It is not currently now and will be past and was future. It is currently all three - which is incoherent.
Yes, assuming that you meant non-zero duration. Where we disagree is whether this non-zero duration must be finite, and therefore measurable.
Quoting Devans99
Quoting aletheist
Quoting Devans99
This once again confuses measurement with reality.
Quoting Devans99
No, I am claiming that all the real moments that we ever experience are indefinite.
Quoting Devans99
This is the fundamental assumption on which we disagree--that the only possible positions are distinct positions.
Quoting Devans99
In fact, true continuity entails that there are possible positions exceeding all multitude, such that they cannot be distinguished; as I have been saying all along, they must be indefinite. We only distinguish, and thereby actualize, the individual positions that we deliberately mark.
Again, this simply doesn't make sense. You can't watch a film for the first time numerous times, can you? On your view you can. So much the worse for your view. It doesn't make sense.
You can live your life once, not numerous times. You can live numerous indistinguishable lives. But living numerous indistinguishable lives is not the same as living the same life again and again. Living the same life again and again would mean watching a film for the first time numerous times - which is obviously impossible.
Quoting Bartricks
Think about 4d spacetime. There is no past/present/future in 4d spacetime. All moments have the same status. So I introduced the moving spotlight idea (not mine) as a way to have eternalism and have a distinction between 'now' and past/present. We can distinguish now from past/present so the concept seems to be a requirement. The moving spotlight moves over Jan 2020 and then X billion years later, it moves over Jan 2020 again.
Quoting Bartricks
It is exactly you who is represented as a pixel on the circle of time and the spotlight comes around many times. So it would be exactly like watching a film for the first time repeatedly.
This doesn't address my point. Put all the fancy labels you like on things, and talk about spotlights to your heart's content, you're not addressing the point.
The point is this: on your view, 'now' is also 'future' and 'past'. So, this moment right now, is also future and also past. No good saying that it is just 'presently now', for it is also presently future, and presently past - on your view.
That's incoherent.
Again: on your view I will watch a film 'for the first time' numerous times - that doesn't make sense, does it?
Not really. Everything would be calibrated to the start/end of time - the Big Bang / Big Crunch. So a moment would have in its future all the moments unto the Big Crunch and in its past all the moments from the Big Bang.
Besides, I do not see the problem. The grandfather paradox is impossible - nothing can pass though the reset point of time at the Big Bang / Big Crunch.
All moments of time are alternatively future, present and past. So I do not see your point.
This sounds good, but has no basis in reality if one is attempting to prove anything about God. Even if you are defining God as an unknown limited entity, which you do here. It is an example of the thinking of a human intellect. It can only be relevant on the assumption that God is made in our image. Which is clearly naive, because by definition God made our universe, of which we are a small part.
To illustrate, God may be a being who does not think in a linear, or binary way like we do, but might have a consciousness which is all knowing and understanding simultaneously, with no reasoning going on. God might have real understanding, while we as primitive minds can only ever assemble a one, or two dimensional conception of an artificial construct(our world). So have no real understanding of anything.
There is a system of thought which is known in mysticism which is analogous to what you are suggesting, but works whatever the unknown entity or God is that one is proposing to encounter. One offers oneself up to any being who is at least as benevolent as ones self. The offer is not made to any being who is less benevolent than oneself. Therefore any being with whom one encounters, through mutual consent, is safe to encounter whatever form they take, because no harm will come of you, because you yourself is sufficiently benevolent, that you would do no harm to any being you encounter, even if they are less benevolent than yourself. Such a system of contemplation is a pre-requisite to any communion with an unknown advanced entity, or God.
Im not sure how you can claim that God can prove that X does not exist where X is some other god. It is impossible to prove that something does not exist. Something could exist in an alternative reality. Therefore even God is 'god-fearing'.
God cannot be omniscient unless he has a very strange nature. The clue is 'know thyself'.
I am saying that our kind of thinking is not up to the job of saying what Gods nature is or isn't. Let me illustrate how God can be both omniscient and limited at the same time. At the end of my last post I mentioned communion. God might be in eternal communion with a near endless number of other Gods, who as a collective are essentially omniscient. So God is not "god fearing", or lacking of any knowledge of all the other Gods out there. On the contrary God might be in eternal communion with all other real beings (remember, I am suggesting that we as we know ourselves are not real, but constructs).
I am mainly deist in belief. So science and God combined. I think of God as some sort of benevolent, timeless architect of the universe.
Quoting Punshhh
The communion might be unaware of another communion of greater gods in another reality. So I still feel my argument about benevolence applies.
Quoting Punshhh
But how could he ever proof to himself that he is in contact with every possible being?
Anyway another point I was going to make in reference to your argument, was that for real beings there might not be any such thing as a non benevolent being, that might only occur in artificially constructed realities.
You're right my bad
Quoting Devans99
If time is circular then why would the spotlight have started at the big bang? It could have started at any point.
If time is circular, events must be deterministic, because if they're not they wouldn't repeat given the same conditions, so time wouldn't be circular
So if time is circular (which implies its events are deterministic) the spotlight could have started anywhere and still gone through the same cycle
Sure, which is not proof.
Quoting Devans99
Maybe?
Quoting Devans99
I've just addressed a couple of them — Leibnizian sufficient reason and your mathematical induction (and similar) — neither of which work. No use in repeating them I s'pose. I can show you again why they don't work. Here's the latter again:
1. suppose no definite earliest time, no 1[sup]st[/sup] moment (premise towards reductio ad absurdum)
2. then there's no 2[sup]nd[/sup] moment, obviously, since it would be the next number following the 1[sup]st[/sup]
3. if there's no n[sup]th[/sup] moment, then there's no n+1[sup]th[/sup] moment (n ? N)
4. thus
4.1. [s]there can be no such moments at all, contra 1 :fire:[/s] (n)
4.2. there can be no such numbering of such moments (y)
Quoting Devans99
I'm not aware of any such proof. As mentioned somewhere, it's not a mere logical matter.
Quoting Devans99
I take "become undefined" to mean more or less "cannot exist". In the abstract, supposing a (definite) 1[sup]st[/sup] moment = "removing all previous moments", which then, by this ? supposition of yours, implies that "all subsequent moments become undefined".
Example square circle: "atemporal" mind.
It's more or less the opposite, if you will.
Where body (for example) is object-like and spatial (left to right, top to bottom, front to back, inertial/movable), mind is process-like and temporal (comes and goes, interruptable, experiences, un/consciousness, anesthetic, dementia).
Barring special pleading, "atemporal" thinking sentience is nonsense.
It depends on how exactly time works:
- If time is fully future real all the time, then the spotlight of time could start anywhere as you say. But fully future real is sort of a tough sell
- So instead I was thinking of a hybrid model between future real and the growing block model of time: The Big Bang is the moment of initial creation. On the first iteration (first circle of time), the future is real but null (so like growing block). Then future is built up - the Big Bang happens, our earth results and later there is a Big Crunch. On the second and subsequent iterations, the future is real and non-null (and repeats exactly as before).
Quoting khaled
I'm not sure that determinism is a requirement: each event happens once (is determined once) but it experienced multiple times.
Actual infinity is impossible (see https://thephilosophyforum.com/discussion/7379/infinite-bananas/p1) and past infinite time is an example of actual infinity. So time must have a start.
And...
1. Assume time had no start
2. Assume a particle had a collision 5 minutes ago, label that 1
3. Assume the particle had a collision 10 minutes ago, label that 2
4. Assume the particle had a collision 20 minutes ago, label that 3
5. And so on, collision numbers getting higher as we go back in time
6. How many collisions has the particle had?
7. It cannot be actually infinite collisions as it is impossible to count to actual infinity
8. So it must have had every number of collisions
9. So the particle has counted every possible number in the past
10. But [9] is impossible, if you count 100 numbers, you are 0% of the way to counting all numbers. If you count a billion numbers, you are 0% of the way there. n/?=0% so it is not possible that the particle counted all numbers
11. So the particle must have a finite number of collisions in the past
12. So time has a start.
Quoting jorndoe
The almost certain existence of a start of time mandates that something atemporal and intelligent exists. You have to remember that as humans we are only familiar with a small fraction of possible states of existence - God maybe something completely different to what we are experienced with.
As shown, we already know some things about mind (versus whatever else), and these are inherently contrary to "atemporal".
Special pleading.
So, we're talking something inert and lifeless, perhaps like Platonia.
By the way, this also violates Leibnizian sufficient reason, but maybe we've tossed that in the bin already?
You think everything has existed forever I think. That is impossible. Imagine an eternal counting alien. He has been counting forever. What number is he on now?
Mind reading fallacy? (I'm entirely irrelevant.)
Could the counting eternal alien be on a finite number? No, then he would not be eternal.
Could the counting eternal alien be on a infinite number? No, impossible to count to infinity.
So by elimination of all possible numbers, he must be on UNDEFINED.
He never started counting (a past forever has no start).
The general rule is 'in order to be X, one has to start X', eg:
- In order to be counting, one has to start counting
- In order to be moving, one has to start moving
- In order to be orbiting, one has to start orbiting
- In order to be existing, one has to start existing
Nothing can exist forever in time. Can't get something from nothing, so something must have always existed. Hence time must have a start and something timeless must exist.
Your argument assumes that time consists of distinct and individual moments. But we experience time as continuous. These two have not been shown to be compatible, so to proceed with your argument you need to demonstrate the real, distinct, individual moments that time consists of, to support your premise. This is the matter which aletheist has brought up.
Since all real moments are indefinite, it is logically impossible to distinguish one from another, let alone "remove" one. We can arbitrarily designate instants to mark off intervals of time with fixed and finite duration, but we cannot "remove" those, either. It straightforwardly begs the question to treat time as if it were isomorphic to the natural numbers, which are discrete and have a first member, thus ruling out the possibility that time is truly continuous and does not have a definite beginning.
As for the thread title, Charles Sanders Peirce has an interesting take.
Real time as a whole either has first and last instants or indeed "must return into itself," but we cannot determine which is the case solely by means of a strictly mathematical "proof."
Mathematical time, conceived as truly continuous, necessarily "returns into itself, and begins again."
Actual time, in which all events occur, might correspond to only a portion of that hypothetical representation, between initial and final instants. We "reckon" actual time by arbitrarily assigning dates in accordance with the fixed and finite intervals between recurring events, such as the earth's rotation around its axis (one day) and revolution around the sun (one year).
Peirce's own cosmology is not "elliptical" (or "circular"), but "hyperbolic," positing that the states corresponding to the initial and final instants are different from each other as ideal limits, rather than actual events--complete chaos in the infinite past, and complete regularity in the infinite future.
How would you suggest removing a moment from time?
Quoting aletheist
We cannot even mark off intervals of time by designating instants, because as special relativity indicates such designations would differ depending on your frame of reference. So to use Einstein's example; what you might call "the instant" that the lightning strikes the embankment is different depending on whether you are on the train or whether you are standing on the platform. But it really doesn't make any sense to talk about instants in time with the premise of special relativity.
Quoting aletheist
We can't, but we know that an infinite past essentially comes with a moment removed at the start so such a construction is therefore impossible.
Infinite past time is like a something from nothing - there is no initial state, so no subsequent states - the existence of the present would therefore be like a magic trick.
Quoting Metaphysician Undercover
Time may run at different rates for different people, but I feel each individual experiences it linearly so it is best represented by a linear series of moments. In SR/GR spacetime has a specific shape to it, so definitely has a temporal starting point (eg the spacetime of the Big Bang and aftermath are visualised as a 3d cone).
This is exactly backwards. An infinite past entails that there has never been a moment that was not preceded by another moment, consistent with the continuity of time that we directly perceive in the present. A definite beginning of time entails that there was one moment in the past that was not preceded by another moment, making it a discontinuity.
Quoting Devans99
Again, this is exactly backwards. Infinite past time entails that there was never nothing, instead always something--namely, time itself. A definite beginning of time entails that something came from nothing, or that something outside of time created it. As I said before, a strictly mathematical "proof" is insufficient to determine which hypothesis--infinite past time or a definite beginning of time--is correct.
There are about 6 other ways to prove time has a start. I gave a couple here:
https://thephilosophyforum.com/discussion/comment/369717
This straightforwardly begs the question by presupposing that being "fully defined" (whatever that means) requires an "initial starting state." Grasping at straws, really.
Quoting Devans99
Again, it is impossible to "prove" that time has a start with only mathematics and logic.
Well I disagree; time is a logical, sequential phenomenon so induction works just fine to prove it has a start. Time with the way one moment defines the next is a example of an infinite causal regress, all of which are impossible as they have no first element.
We can also use physics too: perpetual motion is impossible, therefore time has a start.
Begging the question (again).
Quoting Devans99
Non sequitur.
Are you claiming the future defines the past?
Quoting aletheist
If you had thought it through, you would appreciate that the impossibility of perpetual motion implies a start of motion.
No, the question-begging claim is that time as an infinite succession of moments is impossible because it would have no first element.
Quoting Devans99
Which does not entail a start of time.
So we are talking about an infinite causal regress right? You'd agree they have no first moment? If we take an example of a finite causal regress:
1. The cue hits the white ball
2. The white ball hits the black ball
3. The black ball goes in the pocket
Note that if we remove the first element of the finite causal regress ([1] above) then the rest of the regress disappears.
Infinite causal regress have by definition no first element; so they do not exist / are not possible.
Quoting aletheist
What caused the start of motion? Call it A, what caused A, call it B, what caused B, call it C. So we are in an infinite causal regress. The only way out of such is to posit something uncaused as the base of the regress; IE something from beyond causality; IE something from beyond time. IE time has a start.
Where we mark the "start" of any finite series of events, and how we parse it out into discrete steps, is completely arbitrary. Before #1, presumably a person deliberately pushes the cue such that it hits the white ball. That involves a multitude of mental decisions, nerve signals, and muscle movements. We would have to go much farther back in time before that in order to account for all the causal factors. Moreover, none of the three listed events is instantaneous--each requires a finite interval of time, during which complex physical interactions occur--and in between, each ball presumably rolls across a frictional surface, slightly slowing its velocity.
Quoting Devans99
Again, not relevant; the issue is whether time has a start, not whether motion has a start.
Quoting Devans99
Again, non sequitur; even if something outside of time created time (as we both apparently believe), that would not by itself entail that time had a start.
So it is but a small step to see that any system over an 'infinite' period of time has no initial moment or state and therefore all subsequent states are undefined.
Quoting aletheist
Everything has a start. It does not matter what topology you think time has; it has a start. Name a topology for time that has no start? Circles have start points BTW.
One more argument for you:
1. Assume time has no start
2. The state of the universe is given by the precise positions and velocity vectors of all its particles (10^80 or so in the observable universe I read)
3. Call the current state of the universe X
4. How many times has the universe been in state X in the past?
5. A greater than any number of times *
6. Reductio ad absurdum. [1] is wrong. Time has a start.
* Which is impossible all by itself; you cannot use successive addition to arrive at a number greater than any number
Non sequitur; having no initial moment/state does not entail having no "defined" moments/states (whatever that means), unless we add the question-begging premiss that a first moment/state is required to "define" any other moments/states.
Quoting Devans99
More question-begging.
Quoting Devans99
A straight line extending from the infinite past to the infinite future. A hyperbola for which the initial and final moments/states are ideal limits that never actually occur.
Quoting Devans99
Only if we arbitrarily designate one; a circle in itself has no points of any kind. If I use an inked stamp, I can "create" an entire circle on a piece of paper all at once, with no start point.
Quoting Devans99
Instantaneous states, positions, and velocity vectors are all abstractions that we artificially create to describe reality. They are not themselves real. Besides, our best current science indicates that it is impossible to determine both the position and the velocity of any particle at the same hypothetical instant, let alone all the particles in the universe.
Quoting Devans99
Zero. Besides wrongly treating an instantaneous state as a reality, the latest argumentation wrongly presupposes that the universe can be in the same state more than once.
It is not question begging it is just the way reality works:
- Does today define what happens tomorrow?
- Or does tomorrow define what happens today?
Quoting aletheist
- The probability of being in state X must be greater than 0% (because we have been in that state)
- Leading to the number of times in state X as ? * non-zero = ? times
You cannot prove that time has a start by assuming that time has a start. Besides, if every moment has a preceding moment, then time cannot have a start, because that would require a (first) moment that does not have a preceding moment.
Quoting Devans99
That is not how probability works in the mathematics of infinity.
Where exactly am I assuming that time has a start?
Do you believe that a greater than any finite number of days has passed?
Quoting aletheist
Every moment has another moment before it and there is a start of time if time is a circle.
Quoting aletheist
How does it work?
By insisting that moments/states are "undefined" otherwise.
Quoting Devans99
Time is not composed of days. A day is an arbitrary unit of duration that we use to mark and measure the passage of time.
Quoting Devans99
If time is a circle, then every moment has another moment before it, but there is no start of time unless we arbitrarily designate one. Remember, I can use an ink stamp to "create" an entire circle on a piece of paper all at once.
Quoting aletheist
Quoting Devans99
Again, in reality there are no instantaneous states, so the "probability" of any such state occurring is meaningless. Besides, in infinite time there would be infinitely many such states, and no reason in principle to assume that any two of them are identical.
But time is indubitably linear in nature; earlier times precede and define later times. The argument I am using works for any infinite regress where earlier elements define later elements:
1. An infinite causal regress has no first element
2. If it has no nth element, it has no nth+1 element
3. Therefore no infinite causal regresses exist
Infinite past time would be an infinite causal regress; earlier periods define later periods. So it is just not possible.
Quoting aletheist
It does not matter what unit of time we use. Same question: do you think that a greater than any finite number of Planck time units has passed?
Obviously the point here is that time passing is a sequential process and there is no way for a sequential process to ever construct actual infinity. Hence time must be finite.
Quoting aletheist
Well the start of time would be at the Big Bang / Big Crunch point of the circle.
Quoting aletheist
"In physics, the Poincaré recurrence theorem states that certain systems will, after a sufficiently long but finite time, return to a state arbitrarily close to (for continuous state systems), or exactly the same as (for discrete state systems), their initial state."
https://en.wikipedia.org/wiki/Poincaré_recurrence_theorem
So the argument I've used is valid for continuous systems too. Eternal past time leads to the absurd conclusion that the universe has been in the same identical state a greater than any finite number of times.
Now we really are going in circles. I see no point in continuing (pun intended). Cheers!