Wednesday Open Thread: Tempus is fugiting, or is it?
It's Day 346 of the Year 2018 CE
So, December 12, 2018 - for my reference if nothing else.
Perhaps we'll never know. This is the great question of our time and perhaps of all time. It is no doubt from some perceptions quite simple, go ask Alice. She was participant in the following great discussion in Wonderland:
“Alice sighed wearily. `I think you might do something better with the time,' she said, `than waste it in asking riddles that have no answers.'
`If you knew Time as well as I do,' said the Hatter, `you wouldn't talk about wasting it. It's him.'
`I don't know what you mean,' said Alice.
`Of course you don't!' the Hatter said, tossing his head contemptuously. `I dare say you never even spoke to Time!'
`Perhaps not,' Alice cautiously replied: `but I know I have to beat time when I learn music.'
`Ah! that accounts for it,' said the Hatter. `He won't stand beating. Now, if you only kept on good terms with him, he'd do almost anything you liked with the clock. For instance, suppose it were nine o'clock in the morning, just time to begin lessons: you'd only have to whisper a hint to Time, and round goes the clock in a twinkling! Half-past one, time for dinner!”
-Lewis Carroll - Alice's Adventures in Wonderland
The Hatter hints at the possibility of time's non-uniformity, but for Alice it is really quite simple. Alice reflexively thinks of time signatures, although even in that frame of reference there is complexity. There is "cut time", 2/4, 4/4, 3/4, and, quite famously, 5/4:
Nonetheless, such "time" has a regularity and certainty to it, depending upon how much you trust your metronome to keep a steady and regular beat. Does it? How can you tell? Chronometers, atomic clocks and the like seemingly give reliable measures of the passage of time, but do they?
Beginning physics students are taught that time is a dimension, a measurement of which is integrated into or derived from many equations relating other things. Distance = speed (or velocity) times time. Alternatively, speed (or velocity) = distance divided by time. Acceleration is the rate of change of velocity with respect to time and is generally expressed as meters per second squared. Final velocity = initial velocity plus acceleration times time. Distance = 1/2 times acceleration times time. Little marks on the ruler or axis of time, beats of the chronometer, but time's rate of passage is, in fact variable, as hinted at by the Mad Hatter. Einstein handed us time dilation and I'll hand this off to the wiki:
According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other, or by being differently situated relative to a gravitational field.
This isn't really a great problem for either of those observers, however, because to them time is constant, they cannot know otherwise.
Those physics students also learn that velocity and acceleration are vectors, but time is not explicitly so defined. It is treated as if it were scalar, but it really can't be, because time is unidirectional, but it isn't subject to the rules of vector computation either. You can explore this further here: https://physics.stackexchange.com/questions/59782/is-time-a-scalar-or-a-... This is in part trickery relating to the difference between time and the passage of time, and between time in 3 dimensions and time as a dimension in and of itself, and therein lies the problem.
Way back, Zeno's paradox highlighted the problem with time and the passage of time. If time is truly scalar, pure number, marks on a stick, then no matter how finely you slice the time, nothing can move or transpire within any time quanta, so how can anything possibly move between them. Democritus dealt with this by simply pointing out that we see stuff move, and that's that. One answer is that time is a continuum, time flows, it is not divided into discrete quanta and we and all else flow with it, hence Heraclitus was able to say:
“No man ever steps in the same river twice, for it's not the same river and he's not the same man.”
But is this really a viable answer?
The problem of time, the problem with time, is that we do not experience time in any direct sense. That is to say, we do not directly experience the flow of time. Really? Absolutely, perhaps. I got up this morning, and looking across the room, I clearly saw distance, it could be said that as I walked I paced off distance, but this is less clearly so, for there is a sense in which I cannot experience the flow of distance either, though I can percieve it in a manner in which I cannot percieve time. How so? Essentially, we cannot experience the future or the past, only the present. We are stuck in the here and now, and, like zeno's arrow at any moment during which we are sensate, we are not moving in space or time, we are in one fixed locus in space-time. Time is a construct that we deduce from the fact that we believe that we have experienced a past and that said past was linear with respect to this time construct. If we sit very still and try to grasp it with our mind's eye, it isn't there. We are sure that there is a future and that our remembrances are a record as past futures that became momentarily present and then were history, but, in reality, tomorrow never comes, it is always now.
This is, for what it's worth, a somewhat contentious topic and issue in modern physics. There was a recent post on the Scientific American blog that is short, non technical, and well worth a read: https://blogs.scientificamerican.com/observations/do-we-actually-experie... No less a person than erwin Schroedinger said:
“Time no longer appears to us as a gigantic, world-dominating chronos, nor as a primitive entity, but as something derived from phenomena themselves. It is a figment of my thinking.”
He, of course gave us the cat with no future, an indeterminate juxtoposition of potentialities that only became capable of having a future once it was observed in the present. In a broader sense, we are stuck in a place with no time, because the present has no duration, duration requires that we move from now into the future, but when we get there it will still be now.
(Image: Project 366 #135: 140512 All Together Now, by Pete)
OK, it's an open thread, so go for it ...