Dec 28, 2016 07:01 PM
The Secret Life of Time
http://www.newyorker.com/magazine/2016/1...fe-of-time
EXCERPT: [...] For more than two thousand years, the world’s great minds have argued about the essence of time. Is it finite or infinite? Does it flow like a river or is it granular, proceeding in small bits, like sand trickling through an hourglass? And what is the present? Is now an indivisible instant, a line of vapor between the past and the future? Or is it an instant that can be measured—and, if so, how long is it? And what lies between the instants? “The instant, this strange nature, is something inserted between motion and rest, and it is in no time at all,” Plato remarked in the fourth century B.C.E. “But into it and from it what is moved changes to being at rest, and what is at rest to being moved.”
For St. Augustine, writing his “Confessions” in the year 397, time was even simpler: it’s us. Augustine was forty-three, beginning his tenure as an overwhelmed bishop in Hippo, a port city in North Africa, during the decline of the Roman Empire. The literature on time perception generally begins with Augustine, because he was the first to talk about time as an internal experience—to ask what time is by exploring how it feels to inhabit it. Time may seem slippery and maddeningly abstract, but it’s also deeply intimate, infusing our every word and gesture. Its essence, Augustine argued, can be gleaned from a single line of speech: “Deus creator omnium.”
“God, creator of all things.” Say it aloud or listen: in Latin, eight syllables, alternating short and long. “Each of these latter lasts twice as long as each of the former,” Augustine wrote. “I have only to pronounce the line to report that this is the case.” Yet how do we manage to make this measurement? The line is composed of syllables that the mind encounters in succession, one by one. How can the listener consider two syllables at once to compare their durations? How can one hold the longer syllable in mind? Its duration can’t be defined until it’s completed, but by then both syllables are gone. “Both have made their sound, and flown away, and passed by, and exist no more,” Augustine wrote, asking, “So what now exists for me to measure?”
Here Augustine arrived at an insight so fundamental that it’s taken as a given: time is a property of the mind. When you ask yourself whether one syllable lasts longer than another, you aren’t measuring the syllables themselves (which no longer exist) but something in your memory, “something fixed and permanent there.” The syllables leave an impression that persists in the present. Indeed, Augustine wrote, what we call three tenses are only one. Past, present, and future are all immediate in the mind—our current memory, our current attention, our current expectations. “There are three tenses or times: the present of past things, the present of present things, and the present of future things.” Augustine plucked time from the realm of physics and placed it squarely in what we now call psychology. “In you, my mind, I measure time,” he wrote. Words, sounds, and events come and go, but their passage leaves an impression: “Either time is this impression, or what I measure is not time.”
To consider this present is to glimpse the soul, Augustine argued. Modern science has abandoned the soul in favor of probing the framework of consciousness, a concept that is only slightly less elusive. Yet we share a rough idea of what’s meant: a lasting awareness of one’s self moving in a sea of selves, dependent yet alone, or a deep and common wish that “I” somehow belong to “we,” and that “we” belong to something even larger and less comprehensible; and the recurring thought, so easy to brush aside in the daily effort to get through our to-do lists, that our time matters precisely because it ends.
So much—all that matters, for Augustine—unfolds in a sentence. Recite a poem or a psalm by heart: your mind strains to recall what you’ve said and reaches forward to grab what you will say next. Memory pulls against expectation: “The vital energy of what I am doing is in tension between the two.” Vital energy: that’s the essence of Augustine, and of you, too, right now, as you absorb these words, strive to remember, and wonder what comes next. “Time is nothing other than tension,” Augustine wrote, “and I would be very surprised if it is not tension of consciousness itself....”
Does knowledge of the past and present determine the future?
https://aeon.co/essays/does-knowledge-of...the-future
EXCERPT: [...] But some statements in the future tense do seem to be true; I have given the examples ‘The sun will rise tomorrow’ and, after I have thrown the stone, ‘That window is going to break.’ Let’s look at these more closely. In fact, no such future statement is 100 per cent certain. The sun might not rise tomorrow; there might be a galactic star-trawler heading for the solar system, ready to scoop up the sun tonight and make off with it at nearly the speed of light. When I throw the stone at the window, my big brother, who is a responsible member of the family and a superb cricketer, might be coming round the corner of the house; he might see me throw the stone and catch it so as to save the window.
We did not know that the sun would fail to make its scheduled appearance tomorrow morning; I did not know that my naughtiness would be foiled. But this lack of knowledge is not a specific consequence of the fact that we are talking about the future. If the Spaceguard programme had had a wider remit, we might have seen the star-trawler coming, and then we would have known that we had seen our last sunrise; if I had known my brother’s whereabouts, I could have predicted his window-saving catch. In both these scenarios, the lack of knowledge of the future reduces to lack of knowledge about the present.
The success of modern science gave rise to the idea that this is always true: not knowing the future can always be traced back to not knowing something about the present. As more and more phenomena came under the sway of the laws of physics, so that more and more events could be explained as being caused by previous events, so confidence grew that every future event could be predicted with certainty, given enough knowledge of the present. [...] For a couple of centuries, Newton’s dream seemed to be coming true. More and more of the physical world came under the domain of physics [...] Capricious events such as storms and floods, formerly seen as unpredictable and attributed to the whims of the gods, became susceptible to weather forecasts; and if some such events, like earthquakes, remain unpredictable, we feel sure that advancing knowledge will make them also subject to being forecast.
This scientific programme has been so successful that we have forgotten there was ever any other way to think about the future. [...] Well, it was a nice dream. But it didn’t work out that way. In the early years of the 20th century, Ernest Rutherford, investigating the recently discovered phenomenon of radioactivity, realised that it showed random events happening at a fundamental level of matter, in the atom and its nucleus. [...] other, stranger discoveries at around the same time led to the radical departure from Newtonian physics represented by quantum mechanics, which strongly reinforced the view that events at the smallest scale are indeed random, and there is no possibility of precisely knowing the future.
[...] This theory is itself so puzzling that it is not clear that it should be described as an ‘explanation’ of the puzzling facts it subsumes; but an essential feature of it, which seems inescapable, is that, when applied to give predictions of physical effects, it yields probabilities rather than precise numbers. This is still not universally accepted. Some people believe that there are finer details to be discovered in the make-up of matter, which, if we knew them, would once again make it possible to predict their future behaviour precisely. This is indeed logically possible, but there would necessarily be aspects of such a theory that would lead most physicists to think it highly unlikely....
http://www.newyorker.com/magazine/2016/1...fe-of-time
EXCERPT: [...] For more than two thousand years, the world’s great minds have argued about the essence of time. Is it finite or infinite? Does it flow like a river or is it granular, proceeding in small bits, like sand trickling through an hourglass? And what is the present? Is now an indivisible instant, a line of vapor between the past and the future? Or is it an instant that can be measured—and, if so, how long is it? And what lies between the instants? “The instant, this strange nature, is something inserted between motion and rest, and it is in no time at all,” Plato remarked in the fourth century B.C.E. “But into it and from it what is moved changes to being at rest, and what is at rest to being moved.”
For St. Augustine, writing his “Confessions” in the year 397, time was even simpler: it’s us. Augustine was forty-three, beginning his tenure as an overwhelmed bishop in Hippo, a port city in North Africa, during the decline of the Roman Empire. The literature on time perception generally begins with Augustine, because he was the first to talk about time as an internal experience—to ask what time is by exploring how it feels to inhabit it. Time may seem slippery and maddeningly abstract, but it’s also deeply intimate, infusing our every word and gesture. Its essence, Augustine argued, can be gleaned from a single line of speech: “Deus creator omnium.”
“God, creator of all things.” Say it aloud or listen: in Latin, eight syllables, alternating short and long. “Each of these latter lasts twice as long as each of the former,” Augustine wrote. “I have only to pronounce the line to report that this is the case.” Yet how do we manage to make this measurement? The line is composed of syllables that the mind encounters in succession, one by one. How can the listener consider two syllables at once to compare their durations? How can one hold the longer syllable in mind? Its duration can’t be defined until it’s completed, but by then both syllables are gone. “Both have made their sound, and flown away, and passed by, and exist no more,” Augustine wrote, asking, “So what now exists for me to measure?”
Here Augustine arrived at an insight so fundamental that it’s taken as a given: time is a property of the mind. When you ask yourself whether one syllable lasts longer than another, you aren’t measuring the syllables themselves (which no longer exist) but something in your memory, “something fixed and permanent there.” The syllables leave an impression that persists in the present. Indeed, Augustine wrote, what we call three tenses are only one. Past, present, and future are all immediate in the mind—our current memory, our current attention, our current expectations. “There are three tenses or times: the present of past things, the present of present things, and the present of future things.” Augustine plucked time from the realm of physics and placed it squarely in what we now call psychology. “In you, my mind, I measure time,” he wrote. Words, sounds, and events come and go, but their passage leaves an impression: “Either time is this impression, or what I measure is not time.”
To consider this present is to glimpse the soul, Augustine argued. Modern science has abandoned the soul in favor of probing the framework of consciousness, a concept that is only slightly less elusive. Yet we share a rough idea of what’s meant: a lasting awareness of one’s self moving in a sea of selves, dependent yet alone, or a deep and common wish that “I” somehow belong to “we,” and that “we” belong to something even larger and less comprehensible; and the recurring thought, so easy to brush aside in the daily effort to get through our to-do lists, that our time matters precisely because it ends.
So much—all that matters, for Augustine—unfolds in a sentence. Recite a poem or a psalm by heart: your mind strains to recall what you’ve said and reaches forward to grab what you will say next. Memory pulls against expectation: “The vital energy of what I am doing is in tension between the two.” Vital energy: that’s the essence of Augustine, and of you, too, right now, as you absorb these words, strive to remember, and wonder what comes next. “Time is nothing other than tension,” Augustine wrote, “and I would be very surprised if it is not tension of consciousness itself....”
Does knowledge of the past and present determine the future?
https://aeon.co/essays/does-knowledge-of...the-future
EXCERPT: [...] But some statements in the future tense do seem to be true; I have given the examples ‘The sun will rise tomorrow’ and, after I have thrown the stone, ‘That window is going to break.’ Let’s look at these more closely. In fact, no such future statement is 100 per cent certain. The sun might not rise tomorrow; there might be a galactic star-trawler heading for the solar system, ready to scoop up the sun tonight and make off with it at nearly the speed of light. When I throw the stone at the window, my big brother, who is a responsible member of the family and a superb cricketer, might be coming round the corner of the house; he might see me throw the stone and catch it so as to save the window.
We did not know that the sun would fail to make its scheduled appearance tomorrow morning; I did not know that my naughtiness would be foiled. But this lack of knowledge is not a specific consequence of the fact that we are talking about the future. If the Spaceguard programme had had a wider remit, we might have seen the star-trawler coming, and then we would have known that we had seen our last sunrise; if I had known my brother’s whereabouts, I could have predicted his window-saving catch. In both these scenarios, the lack of knowledge of the future reduces to lack of knowledge about the present.
The success of modern science gave rise to the idea that this is always true: not knowing the future can always be traced back to not knowing something about the present. As more and more phenomena came under the sway of the laws of physics, so that more and more events could be explained as being caused by previous events, so confidence grew that every future event could be predicted with certainty, given enough knowledge of the present. [...] For a couple of centuries, Newton’s dream seemed to be coming true. More and more of the physical world came under the domain of physics [...] Capricious events such as storms and floods, formerly seen as unpredictable and attributed to the whims of the gods, became susceptible to weather forecasts; and if some such events, like earthquakes, remain unpredictable, we feel sure that advancing knowledge will make them also subject to being forecast.
This scientific programme has been so successful that we have forgotten there was ever any other way to think about the future. [...] Well, it was a nice dream. But it didn’t work out that way. In the early years of the 20th century, Ernest Rutherford, investigating the recently discovered phenomenon of radioactivity, realised that it showed random events happening at a fundamental level of matter, in the atom and its nucleus. [...] other, stranger discoveries at around the same time led to the radical departure from Newtonian physics represented by quantum mechanics, which strongly reinforced the view that events at the smallest scale are indeed random, and there is no possibility of precisely knowing the future.
[...] This theory is itself so puzzling that it is not clear that it should be described as an ‘explanation’ of the puzzling facts it subsumes; but an essential feature of it, which seems inescapable, is that, when applied to give predictions of physical effects, it yields probabilities rather than precise numbers. This is still not universally accepted. Some people believe that there are finer details to be discovered in the make-up of matter, which, if we knew them, would once again make it possible to predict their future behaviour precisely. This is indeed logically possible, but there would necessarily be aspects of such a theory that would lead most physicists to think it highly unlikely....