My theist debating acquaintance, MG, from another place, who just doesn't accept the concept of a temporal infinity[#] (either a linear one or a circular one, either one with cyclic events) on the grounds that you can't get to “Now” from either the starting point of an infinite past or by going backwards from an infinite future. I'd argue that the everyday concept of mathematical Pi disputes MG's assertion.
[#] Despite the fact that theists accept the concept as given that God is an eternal / everlasting being without beginning and without end.
[Note: I debated with MG the reason I think that there is a temporal infinity and as such any specific happening would have to ultimately repeat. I often used the analogy of walking around a sphere an infinite number of times and thus repeating being in a specific location at a specific “Now” or approaching “Now”. MG responds… ]
MG – “There is no reason to think a repetitive pattern will emerge. Just think of numbers like pi (an infinite set of numerals that never repeats nor demonstrates any cyclical pattern).”
JP – Even in Pi you will find repeating patterns. How many times will you find say 27, 33, 42 or 007 within the Pi sequence? Each time you find, say 42, that's a repeat of the first 42! Even the number “4” is a unique event that randomly repeats. For that matter, you could consider Pi to be a series, not of necessity in sequence, of ten separate ‘events' – 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Nice try!
MG – “Even if it did repeat over and over, it would be true that it had repeated a certain number of times. If that number is infinite, then an actually infinite number of events had to be traversed prior to the current one for that particle, and we are right back in the same contradiction.”
JP – Go back and re-read my analogy with the sphere and how you can go around and around an infinite number of times, participate in an infinite number of events, and still be within spitting distance of “The Present Moment”.
MG – “Pi might have the same numeral show up, but not in any CYCLICAL PATTERN.”
JP – And I stated exactly that! Re-read my post.
MG – “You messed up on this one. Just admit it and move on.”
JP – I admit no such thing! The infinity of Pi (ah, you've admitted an infinity) is composed of a finite number of individual numbers (0 through 9). That's a good analogy for there being an infinite number of individual finite events. Note that I have consistently said that infinity consists of an infinite number of finite events. You are just one finite event in a sequence of infinite finite events and collectively that is what infinity is. Back to the Pi analogy: The number 4 is a finite event (like you are a finite event) within the infinite sequence we call Pi. The finite number 4 happens an infinite number of times in the sequence we call Pi. The number 4 is therefore infinitely cyclic within the Pi sequence but the number 4 itself does not have any specific cyclic pattern within the Pi sequence.
MG – “And as long as 4 doesn't come up with cyclical regularity in pi, then pi counts as a complete counter-argument to your cyclical time argument (for which you presented zero evidence).”
JP – As long as 4 comes up again and again and again, whether in an irregular pattern or in a regular pattern, and as long as 4 stands in for some sort of event, then translated to a cosmic setting, that event has happened again and again.
*MG argues for an absolutely temporal finite Universe which required an actual creation and therefore a creator, and therefore God exists and God done it. However, perhaps even a finite Universe is an infinite one. By analogy, Pi has a finite beginning yet it has apparently infinite duration. Or, even if Pi does eventually repeat or come to finality, there's 1/3rd which also has a finite beginning but which is also infinite in duration. Therefore, even if our Universe had a finite beginning, it is still infinite if there is no temporal end to it.
*It would take a temporally infinite you an infinity of time to calculate the entirety of Pi, but in attempting to do so, you would be SOMEWHERE within the sequence at any given moment, a moment you would call “Now”. In other words, you could have started a journey through time starting an infinite amount of time ago and still be at a point we call “The Present Moment” or “Now”.
*Looking Infinitely Forward: Let's say for sake of argument that the “Looking Infinitely Back” problems have been resolved in MG's favor. That is, the Universe had an absolute beginning a finite amount of time ago. Now there's the “Looking Infinitely Forward” versions of issues to be resolved.
But doesn't the issue of not being able to get from an infinite past to “Now” also work the other way around? Presumably if you start travelling – even if mentally – back from an infinite future, you couldn't thus in time travelling backwards ever reach “Now” either. This is relevant because like Pi [#], we have a finite beginning yet, according to theists, have ‘life' everlasting or everlasting ‘life'; ‘life' eternal or eternal ‘life' in the afterlife. So how do you come back to “Now” from the infinite future? So, theists have the same infinity problem only in reverse.
[#] I'm not really sure how one can have a one-sided infinity as in an infinite past that terminates, or a finite beginning that never terminates. Yet, Pi has a finite beginning yet an (apparently) infinite ‘end'.
*If you can actually have a one-sided infinity as in creation hence an eternal ‘life', or Pi, then logically you can have an infinite ‘beginning' or a ‘beginning' an infinite amount of time ago, and a finite ending, or in other words what you can term as “Now”. If one, then the other. If the other – finite beginning; infinite ‘end' – then something can undergo an infinite journey in time and arrive at “Now”.