“No time but the present” from my friend Jeff Courtney’s Digital Dao
What is time? Was there a beginning to time? If so, what preceded it? Is time “real”? If so, is time more real than chairs, for example? Is time continuous or is it a string of moments? Is time affected by the presence of human beings? Is time “being”? Or is there no such thing as time? Does time pass or do we exist in a beginning-less and endless now? An argument could be made that our attitude to time is the most fundamental of our philosophical or religious thoughts or positions. What difference does our attitude to time make in our lives?
I was about to say “in the twenty-first century” but that sort of marker is part and parcel of the very question of time. I should state right away that I will use such conventions as “twenty-first century” very much in the conventional way. We have enough to worry about in discussing time without living under the cloud of this conundrum. But this conundrum itself points to the enormous difficulty in discussing time, because of the self-referential problem that we always have time with us. How we could gain distance on it? This is very much the problem we have in discussing it.
Since Zeno, space and time have been considered together and this joining has only been more firmly emphasized in our post-Einstein world. Can these two be separated or do they only exist together? In this piece I want to explore several attitudes to time, from Zeno and Aristotle to Reverend Gotama and Dogen on up to the amazing world of contemporary astrophysics and cosmology.
Heracleitus or Parmenides (or Both?)
“It is not possible to step twice into the same river.” Heracleitus of Ephesus (Freeman’s English translation, Ancilla to the Pre-Socratic Philosophers, Fragment 91)
“There is only one description of the way remaining, (namely), that (What Is) Is. To this way there are very many sign-posts: that Being has no coming-into-being and no destruction, for it is whole of limb, without motion and without end. . . . For nothing else either is or shall be except Being, since Fate has tied it down to be a whole and motionless.” Parmenides of Elea (Freeman translation, Fragment 8)
Time is at the heart of physics, the study of the natural world and metaphysics, the study of thinking about the natural world. The two pillars of Western thinking about time are Heracleitus and Parmenides. The first seems to have emphasized the real nature of time and motion, the second imagined a timeless world complete and motionless. Which one is correct? We will see that, now over 2,500 years after these two set out the poles of the argument, the discussion still rages.
Zeno on Motion, Time and Infinity
What little we know of Zeno comes primarily from the writings of Aristotle and Plato. The Zeno that we are talking about here is the Zeno who lived in Elea and who was, according to Plato’s Parmenides dialog, a contemporary of Socrates. Elea was a colony of Greeks who had settled in Western Italy. A small ruin remains of the ancient city near to the contemporary town of Velia, south of Salerno. The train from Salerno travels through a tunnel directly beneath the acropolis of the ancient city. It is visited today by a very few tourists (including the author) and nearby school students on field trip. The Porta Rosa above separates the main town from the acropolis.
Diogenes Laertius has a very short note on Zeno of Elea as compared with close to the 150 pages of Greek / English in his Loeb volume devoted to Zeno of Citium, the Stoic. Plato tells us that Zeno was a student, or at least a fellow-traveler with, Parmenides, the great philosopher and law giver of Elea and that the two discoursed with Socrates on their trip to Athens for the Great Panathenaea. Zeno is known for his paradoxes of motion which are bound up with the interplay of motion and time:
1) The Dichotomy
2) Achilles and the Tortoise
3) The Arrow
4) The Stadium
These arguments were apparently aimed at supporting the Parmenidean position that reality is one (although there is some doubt (See here.) As Plato says in the Parmenides,
“In reality, this writing is a sort of reinforcement for the argument of Parmenides against those who try to turn it into ridicule on the ground that, if reality is one, the argument becomes involved in many absurdities and contradictions. This writing argues against these who uphold a Many, and give them back as good as they gave; its aim is to show that their assumption of multiplicity will be involved in still more absurdities than the assumption of unity, if it is sufficiently worked out.” (Burnet’s translation in Early Greek Philosophy)
The only bits of writing that we have directly attributed to Zeno by Diels amount to one page in the Freeman’s English translation; three bits treat of the One versus the Many and one tiny, but interesting, fragment deals with motion, “That which moves, moves neither in the place in which it is, nor in that in which it is not.” (Ancilla to the Pre-Socratic Philosophers)
Aristotle relates the arguments on motion (and time) as follows:
“Zeno’s arguments about motion, which cause so much trouble to those who try to answer them, are four in number. The first asserts the non-existence of motion on the ground that that which is in locomotion must arrive at the half-way stage before it arrives at the goal. . . .
The second is the so-called Achilles, and amounts to this, that in a race the quickest runner can never overtake the slowest, since the pursuer must first reach the point whence the pursued started, so that the slower must always hold a lead. . . .
The third is that . . . . to the effect that the flying arrow is at rest, which result follows from the assumption that time is composed of moments: if this assumption is not granted, the conclusion will not follow.
The fourth argument is that concerning equal bodies which move alongside equal bodies in the stadium from opposite direction – the ones from the end of the stadium, the others from the middle – at equal speeds, in which he thinks it follows that half the time is equal to its double.” (Physics, 239b10-240, revised Oxford translation by Hardie and Gaye.)
Burnet summarizes the goal of these arguments as follows: “This argument (the fourth, the Stadium), like the others, is intended to bring out the absurd conclusions which follow from the assumption that all quantity is discrete, and what Zeno has really done is to establish the conception of continuous quantity by a reductio ad absurdum of the other hypotheses.” In other words, Zeno was arguing not that moments are all that we have, but that to think so is absurd. It was apparently an attempt to support the idea of a block universe, a concept that was reborn 2,500 years later in Einstein’s general relativity theory, of which more anon.
The twentieth century saw an explosion of interest in Zeno by philosophers. Most of the concern with Zeno’s paradoxes focused how they interact with the concept of infinity and infinite series. Bertrand Russell’s lecture on “The Problem of Infinity considered historically” appeared in his 1914 book, Our Knowledge of the External World. Towards the end of this lecture, he writes,
“Zeno’s arguments, in some form, have afforded grounds for almost all the theories of space and time and infinity which have been constructed from his day to our own. We have seen that all of his arguments are valid (with certain reasonable hypotheses) on the assumption that finite spaces and times consist of a finite number of points and instants, and that the third and fourth almost certainly in fact proceeded on this assumption, while the first and the second, which were perhaps intended to refute the opposite assumption, were in that case fallacious. We may therefore escape from his paradoxes either by maintaining that, (1) though space and time do consist of points and instants, the number of them in any finite interval is infinite; or (2) by denying that space and time consist of points and instants at all; or (3) lastly, by denying the reality of space and time altogether.”
Russell goes on to say that it seems Zeno was arguing for the third possibility, that Bergson argued for the second, but that Russell himself sees that the first is justified by the mathematical theories of Cantor in the nineteenth century.
The last half of Russell’s lecture is reprinted as an introductory essay in the 1970 book edited by Wesley Salmon, Zeno’s Paradoxes. This book, which has been used in many philosophy courses in the US since, includes classic essays on Zeno by Henri Bergson, J.O Wisdom, Max Black, G.E.L. Thompson and concluding articles by Adolf Grunbaum, to whom Salmon gives the credit for coming closest to “solving” the paradoxes, following the suggestions of Russell and based on the mathematics of Cantor: “Thus Zeno’s mathematical paradoxes are avoided in the formal part of a geometry built on Cantorian foundations”. (Grunbaum, “Zeno’s Metrical Paradox of Extension,” in Salmon, Zeno’s Paradoxes)
Many other philosophers have taken a crack at Zeno, including very stimulating essays by Gregory Vlastos, reprinted in the book Studies in Greek Philosophy, Volume I, The Presocratics, Gilbert Ryle in his book, Dilemmas and even David Foster Wallace in his book Everything and More, A complete History of ∞. No one really doubts that we can’t walk across the street, as would be implied by The Dichotomy, for example, but Zeno’s paradoxes have been heroically difficult to unravel. DFW concludes his infinity book with the words,
“Gödel’s own personal view was that the Continuum Hypothesis (that there exists no set whose power is greater than that of the naturals and less than that of the reals) is false, that there are actually a whole ∞ of Zeno-type ∞s nested between 0 and c, and that sooner or later a principle would be found that proved this. As of now, no such principle’s ever been found. Gödel and Cantor both died in confinement bequeathing a world with no finite circumference. One that spins, now, in a new kind of all-formal Void. Mathematics continues to get out of bed.”
The important issue for the current project is Zeno’s concept of time: essentially that time is an illusion. But note Russell’s conclusion that Zeno’s argument for the particularity of time, in spite of his goal to prove the opposite, was impregnable, at least up to the nineteenth century. We will see that Zeno’s arguments really set the table for the strife that we have seen in contemporary cosmology.
Aristotle’s Reply to Zeno
Aristotle’s own attitude was that “Zeno’s reasoning . . . is fallacious, when he says that if everything when it occupies an equal space is at rest, and if that which is in locomotion is always in a now, the flying arrow is therefore motionless. This is false; for time is not composed of indivisible nows any more that any other magnitude is composed of indivisibles.'”[239b, 5-13, Oxford revised translation]
Aristotle’s attempts to define time positively are typically meandering. He says,
” . . . . it either does not exist at all or barely, and in the obscure way . . . . Again, the ‘now’ which seems to bound the past and the future – does it always remain one and the same or is it always other and other? It is hard to say. . . . . For we may lay it down that one ‘now’ cannot be next to another, any more that a point to a point. If then it did not cease to be in the next ‘now’ but in another, it would exist simultaneously with the innumberable ‘nows’ between the two – which is impossible. . . . Clearly then it (time) is not movement . . . But neither does time exist without change . . . it is evident, then, that time is neither movement nor independent of movement. . . . . Time, then, also is made continuous by the ‘now’ and divided by it. . . . In so far as the ‘now’ is a boundary, it is not time, but an attribute of it; in so far as it numbers, it is number, for boundaries being only to that which they bound, but number (e.g. ten) is the number of these horses, and belongs also elsewhere. . . . It is clear (!) then, that time is number of movement in respect of the before and after, and is continuous since it is an attribute of what is continuous.” [217b29 – 220a26]
So Aristotle was a believer in time as a continuum. This is an attitude that would have powerful force in the West in the millennia to come.
Reverend Gotama on Time
Reverend Siddhattha Gotama, aka the Buddha, in general stayed far away from metaphysical (or physical) speculation. In the Potthapada Sutta, however, which I have addressed in more detail here, he does address the issue of the beginning of time and space. The sutta tells the story of a discussion with a wandering mendicant, Potthapada, which took place in the Jeta Grove, a park given by the rich merchant Anatha Pindika for the use of Gotama and his group of followers. The suttas say (elsewhere) that Gotama spent the last twenty years of his life residing in Savatthi during the rainy season. The park today is maintained by the Indian government as a place of pilgrimage and as a tourist attraction (visited by the author.)
The first four questions by Potthapada deal with questions of time and space:
Then, sir, if that be so, tell me at least: Is the world eternal? Is this alone the truth, and any other view mere folly?
‘That, Potthapada (Gotama answers) is a matter on which I have expressed no opinion.’
[Then, in the same terms, Potthapada asked each of the following questions: –
2. Is the world not eternal? –
3. Is the world finite?
4. Is the world not finite?
. . . .
And to each question the Exalted One made the same reply:-]
‘That too, Potthapada, is a matter on which I have expressed no opinion.’ (Potthapada Sutta in the Dialogues of the Buddha (Digha Nikaya) translated from the Pali by T.W. Rhys Davids, Pali Text Society, Part I)
This is also the sutta in which Gotama expresses no interest in the subject of rebirth of the Tatagatha (himself), but that is discussed in the earlier post that I have referenced. In the current post, I am interested only in Gotama’s lack of a theory on the beginning or finitude of the world. This sutta, and a similar sutta in the Samyutta Nikaya (the Aggi-Vacchagotta Sutta) suggest that Gotama was a sceptic on these metaphysical issues. As we shall see, many Western philosophers and physicists have not been so humble.
Genesis or Cyclic Rebirth
“Creación de Adám” Sistene Chapel Ceiling – Photo from Wikipedia
The ancient Hebrew view of the nature of time was straightforward; there was a beginning and it was created by God.
“In the beginning God created the heavens and the earth. The earth was without form and void, and darkness was upon the face of the deep; and the Spirit of God was moving over the face of the waters. . . . And God made the beasts of the earth according to their kinds . . . . So God created man in his own image . . . ” (Genesis, 1-2, 25, 27, The Oxford Annotated Bible)
But on the other side of the “civilized world,” in India, a cyclic world was being imagined.
“There comes a time, Vasettha, when, sooner or later, after a lapse of a long, long period, this world passes away. And when this happens, beings have mostly been reborn in the World of Radiance; and there they dwell, made of mind, feeding on rapture, self-luminous, traversing the air, continuing in glory, and thus they remain for a long, long period of time. There comes also a time, Vasettha, when sooner or later this world begins to re-evolve. When this happens, beings who had deceased from the World of Radiance, usually come to life as humans. And they become made of mind, feeding on rapture, self-luminous, traversing the air, continuing in glory, and remain thus for a long period of time.”(Agganna Suttana, A book of genesis, Dialogues of the Buddha, Part III, [84-85] translated from the Pali of the Digha-Nikaya by T.W. and C.A.F. Rhys Davids)
But doesn’t this contradict Reverend Gotama’s disavowal of speculation on metaphysical matters that I have quoted above? Of course it does. I chalk this up to the fact that the Pali Canon was compiled in writing several hundred years after the life of Reverend Gotama and was used for many purposes other than those Gotama may have intended. Have we ever seen that happen in the world before?
My point here is not to illustrate contradictions in the Pali Canon, but to show the contradictory theses about the beginning of time held in ancient Palestine compared to ancient India. Strangely, these contradictory theories will reappear in modern cosmology.
Dogen on Time Being
Eiheiji – Founded by Dogen Kigen (Photo from the Web)
Dogen Kigen is credited traditionally as the founder of the Japanese Soto Zen school and is widely recognized as one of the most profound, and also one of the most enigmatic, of the philosopher zen men. He lived in the thirteenth century and was trained from the age of thirteen in Tendai monasteries in or around Kyoto. He spent years studying at a Tendai temple in Kyoto where the priest Myoan Eisai had been teaching the practice and methods of the Chinese Lin-Chi (Rinzai in Japanese) school. At the age of twenty three he traveled with Eisai’s student Myozen to Sung Dynasty China.
Dogen himself says of this,
“After the thought of enlightenment arose, I began to search for the dharma, visiting teachers at various places in our country. Then I met priest Myozen, of Kennin Monastery, by whom I was trained for nine years. Thus I learned a little about the teaching of the Rinzai School. Priest Myozen alone, as a senior disciple of ancestor Eisai, correctly transmitted the unsurpassable buddha-dharma; no one can be compared with him.
Later I went to Great Song China, visiting masters on both sides of the Zhe River, and heard the teachings of the Five Schools. Finally I studied with Zen master Rujing of Taibo Peak and completed my life’s quest of the great matter.” (On the Endeavor of the Way, Bendo-Wa, in Moon in a Dewdrop, writings of Zen Master Dogen, edited by Kazuaki Tanahashi, this fascicle translated from the Japanese by Lew Richmond and Kazuaki Tanahashi)
This quote is contained in the Japanese collection of Dogen’s essays and talks titled the Shobogenzo, or Treasury of the True Dharma Eye. One of the more famous of the fascicles in this collection, and one of them most puzzling, is the fascicle titled Uji, variously translated as The Time Being, Being Time or Being-Time. This fascicle has been translated into English (differently) by Tanahashi (in Moon in a Dewdrop), Norman Waddell and Masao Abe (in The Heart of Dogen’s Shobogenzo, Thomas Cleary (in Shobogenzo, Zen Essays by Dogen; and by Rein Raud (in ‘The Existential Moment: rereading Dogen’s Theory of Time’, Philosophy East and West, Volume 62, Number 2).
Uji starts out (in Waddell and Abe’s English translation) as follows:
“An old Buddha said:
For the time being, I stand astride the highest mountain peaks.
For the time being, I move on the deepest depths of the ocean floor.
For the time being, I’m the three heads and eight arms.
For the time being, I’m eight feet or sixteen feet.
For the time being, I’m staff or a whisk.
For the time being, I’m a pillar or a lantern.
For the time being, I’m Mr. Chang or Mr. Li.
For the time being, I’m the great earth and heavens above.
The “time being” means time, just as it is, is being, and being is all time.
The sixteen-foot golden Buddha-body is time; because it is time, it has time’s glorious golden radiance. You must learn to see this glorious radiance in the twelve hours of your day. The [demonic ashura with] three heads and eight arms is time; because it is time, it can be in no way different from the twelve hours of your day. Although you never measure the length or brevity of the twelve hours, their swiftness or slowness, you still call them the twelve hours. As evidence of their going and coming is obvious, you do not come to doubt them. But even though you do not have doubts about them, that is not to say you know them. Such sentient being’s doubting of the many and various things unknown to him are naturally vague and indefinite, the course his doubtings will take will probably not bring them to coincide with this present doubt. Nonetheless, the doubts themselves are, after all, none other than time.”
What to make of this? Ramblings of a mad zen man? Deep understanding of the contradictory nature of time and life? Which will it be? Cleary says of this in the introduction to his translation,
“This essay has provoked the interest of most modern writers on Dogen, presenting what seems to be his most original idea: the identity of being and time. This might be represented by the statement that time is a necessary factor of all manifestations of being. But Dogen is less abstract. In effect, time here is seen as being concrete, being is seen as concrete, and the two are seen as inseparable in this concreteness. Ordinary definitions of time, understood in terms of duration of objects or events, or as differentiations of velocity and distance, demand a concrete context so the notion of the inseparability of being and time, arresting though it may be when expressed as being-time, is not especially difficult for the modern reader to acknowledge. What is more, Dogen’s idea of being time bears a degree of resemblance to the concept of space-time in the relativity theory of modern physics. In space-time, time is the fourth dimension, or fourth coordinate in terms of which, along with three space-like coordinates, events are described.”
Raud is anxious to point out the difference between the durational view of time characteristic of Aristotle and the momentary time of Dogen and Zeno’s argument. He thinks that interpretation of Dogen has been infected with too much of that durational bias: “There is also an important conceptual difference between ‘time’ and ‘moments’ flying by. When we read the text in the durational mode, we have to assume that some of the time that flies by is constantly present, while some of it has passed (Abe / Waddell: ‘if time were to give itself to merely flying past, it would have to leave gaps’; Cleary; “if time only were to fly, then there would be gaps’; it remains unclear where the gaps come from — the reading of Tanahashi, ‘If time merely flies away, you would be separated from time,’ although more logical, is not supported by the text). But the problem is solved if we assume that what are seen to fly by are moments: if we would, indeed, against the text’s admonition, presume that moments fly past, one after another, like the stages of the movement of Zeno’s arrow, it would be logical to ask what is present during the almost imperceptible interval when one moment has passed and another one is still not here.”
Raud is speaking of a passage translated by Waddell and Abe as, “Hence, pine trees are time. So are bamboos. You should not come to understand that time is only flying by. You should not only learn that flying past is the virtue inherent in time. If time were to give itself to merely flying past, it would have to leave gaps.” Raun’s translation of this is: “This being so, the pines are momentary and the bamboos are momentary as well. You should not conceptualize a moment as something that flies by, nor study ‘flying by’ merely as the capacity of a moment. If moments could be fully defined by the capacity to fly by, there would be gaps in between them.” Raun insists on the translation of the Japanese word, kyokyaku, as “shifting”, rather than the Waddell and Abe translation of this word as “seriatum passage,” and Tanahashi’s translation as “flowing.” Raun insists that this better gets at what Dogen was saying: “What it requires is dismissing the notions of ‘today’, ‘yesterday’, and ‘tomorrow’ from among the categories of our direct experience, and assigning them the role of merely linguistic devices to help us approach reality but are never able to completely fully refer to it.” Raud translates “Uji” itself as “existential moment,” and maintains that if we so translate it, “as opposed to measurable and divisible time, we obtain much more lucid reading of many of the passages of the fascicle.”
Maybe, but what exactly IS Dogen getting at here? Masao Abe, who is probably the most prominent Dogen scholar of the twentieth century, starts the chapter, ‘Dogen’s View of Time and Space’ in his book, A Study of Dogen, with the words, “Dogen’s view of time and space cannot be understood apart from his standpoint of Buddha-nature.” OK. We have been reading in the wrong place, if we are trying to figure Dogen out simply by reading Uji.
But what is “his standpoint of Buddha-nature?” Abe writes, “Dogen’s standpoints of Buddha-nature and continuous practice are based primarily on subjectivity that was forged in his encounter with and overcoming of his doubt concerning Tendai original-enlightenment thought and his formulation of the doctrine of the oneness of practice and attainment.” To roughly summarize, the Tendai thinking was that you already have perfect enlightenment, you just need to realize it. Dogen was puzzled by this. Why am I studying the Way if I am already enlightened? What was his answer? Abe points to a passage from the fascicle, ‘Bendowa’ translated by Waddell and Abe as ‘Negotiating the Way’:
“When just one person, one at a time, sits in zazen, he becomes imperceptibly, one with each and all of the myriad things, and permeates completely all time, so that within the limitless universe, throughout past, future and present, he is performing the eternal and ceaseless work of guiding beings to enlightenment. It is, for each and every thing, one and the same undifferentiated practice, and undifferentiated realization.”
This seems to be a succinct summary of Dogen’s view. Abe quotes the entire passage twice in his essay. Our experience of time is subjective, as needs be from our perspective as an impermanent living being, but with connection to ‘the myriad things,’ including past and future. Abe goes on to identify what he suggests are three points to ‘clearly establish’ Dogen’s view of time and space:
1) “Each and every being as it is realizes all other beings, and each and every time as it is realizes all other times. It is in and through the self that being and time in the above sense are identical. This is the truth of being-time.”
2) “Each and every being does not sequentially turn into or become (naru-seiseisuru) another being, and in the same way, each and every time does not continuously pass away (naru-seiseisuru) into another time. Rather, each and every being is the spontaneous manifestation (genjo) of all beings while maintaining its particular dharma-stage, and in the same way, each and every time makes a passageless-passage (kyoryaku) to other times while maintaining its particular dharma-stage at this very moment.”
3) “The truth of being-time is never realized apart from this very place (absolute here) and this very time (absolute now).”
Note the change in Abe’s English translation here from his 1992 book of the term “kyoryaku” as “passage-less passage” to “seriatum passage” or simply “passage” in the Waddell translation of Uji, originally published in the Eastern Buddhist magazine and in book form in 2003. Abe emphasizes the subjective standpoint in Dogen’s thought of the “self-liberating Self that has cast off body and mind.” This is a classic image from Dogen’s writing. Another is the image of contradiction. In Abe’s words, “Uji is not realized apart from mind and the body-mind that have been cast off. In this sense uji cannot be sufficiently grasped from the standpoint of being-time. Uji must be grasped from the standpoint of muji, that is nothingness-time. It is only when grasped from the standpoint of muji, or nothingness-time, that uji, being-time, can be truly grasped as uji, being-time.”
The depths and great fun of Dogen’s writing cannot be conveyed in a single blog post. The English reader is very much encouraged to delve into the English translations of Dogen’s Japanese by Waddell and Abe, Cleary and Tanahashi that I have referenced above. I was introduced to Dogen first by listening to the audio cassettes published by North Point Press and read by the poet Gary Snyder. I can still hear Snyder’s voice reading Tanahashi’s translations. Actually, I can hear them right now, since the Walkman that I purchased in Singapore in 1993 still works! Snyder reads, “On the Endeavor of the Way – Bendowa. All buddha tathagatas, who directly transmit inconceivable dharma and actualize supreme, perfect enlightenment, have a wondrous way, unsurpassed and unconditioned. Only buddhas transmit it to buddhas without veering off; self-fulfilling samadhi is its standard. Sitting upright, practicing Zen, is the authentic gate to the unconfined realm of this samadhi.” (Also listen to Snyder here.)
Let’s give the last word to Dogen in Uji (from Tanahashi’s English translation):
“Mind is the moment of actualizing the fundamental point; words are the moment of going beyond, unlocking the barrier. Arriving is the moment of casting off the body; not arriving is the moment of being one with just this, while being free from just this. In this way you must endeavor to actualize the time-being.”
Kant on the Beginnings of Time
And speaking of contradictions, Kant’s first antimony treats of the exactly same questions addressed by Gotama two thousand years earlier: whether time and space have a beginning. Kant forms these in his famous Thesis and Antithesis form as follows:
“Thesis:The world has a beginning in time, and is also limited as regards space.
Antithesis: The world has no beginning, and no limits in space; it is infinite as regards space and time.” (Critque of Pure Reason, A.426 B. 454, translated into English by Norman Kemp Smith)
Kant provides “proofs” to both sides of these dichotomies, as examples of his transcendental reason. That the proofs of both thesis and antithesis are fallacious has been maintained by both Kemp Smith in his commentary and Russell (in the early part of his lecture on infinity referenced above). There is no need to go into these arguments here. My point here is to lay down an eighteenth century Western milestone in our tour of theories on time.
We have given several indications of contradictory theories about time reappearing in modern cosmology. I want to conclude this post by discussing several books which illustrate this controversy.
The first is the book, About Time, by Adam Frank, a professor of astrophysics at the University of Rochester and a co-founder of the NPR blog: 13:7 Cosmos and Culture. Frank’s 2011 book provides an illuminating survey of the history of modern cosmology; the evolution from the pre-history of humans in the West to debates at astrophysics conferences in our own time. The first signs of speculation about time he sees in the story of markings on a bone fragment found on the floor of a cave in the Dordogne which was later argued to represent a marking of the passage of lunar time. This fragment dates from twelve to twenty thousand years ago. From here Frank gives a very entertaining telling of the story of our fascination with cosmology: from our paleolithic ancestors, to the neolithic megalith at Stonehenge, the agricultural view of Hesiod’s Works and Days, the urban revolution of Ptolemy, the Renaissance invention of the mechanical clock and to Newton’s absolute time and absolute space and Einstein in his patent office job reviewing electromechanical time synchronization patents.
Newton’s work described a world of time, force, matter, and motion that would transform our understanding of the physical world. According to the physics of Aristotle, which still dominated the world into which Newton was born, “the universe was a plenum, a material continuum. In their view there could be no space without matter. In an echo of Parmenides, a truly empty space was thought to be impossible. . . . If time and space did not exist without matter, how was matter supposed to move though them?” Following up on his study of Kepler, Galileo and Descartes, Newton’s innovation was “to make space and time separate realities.” Frank describes Newton’s revolutionary achievement as follows:
- “Absolute, true and mathematical time passes equally without relation to anything external and without reference to any change in matter of the way in which it is measured (e.g., the hour, day, month or year).
- Absolute, true and mathematical space is the same everywhere; its properties remain fixed without relation to changes in matter.
- Absolute motion is the movement of a body from one position in absolute space to another.”
Frank concludes, “In what might be considered a marriage of the visions of Parmenides and Heraclitus, change and eternity were fused. Timeless, immutable laws governed the universe and the progress and nature of change.” Newton’s mechanics were a leap of imagination, but the practical application of his laws of mechanics have been crucial to the development of our industrial world. Perhaps this is what so bothered Blake about Newton!
Einstein’s day job led, as we all know by now, to his working out in the evenings at home the theoretical mechanics of time, waves and simultaneity that became his special theory of relativity and which was later expanded by Minkowski into a general theory mapping out the 4-dimensional world of space-time. “The philosophical implications of the new perspective were startling. Once again the ghost of Parmenides would hover behind a new development in theoretical physics. The future and past took on a different character in the so-called block universe of space-time. In this vision of relativity, next Tuesday, which we consider to be the future, already exists. The past and the future are reduced to events that exist together in the totality of a timeless, eternal block of space-time.”
While Einstein’s and Minkowski’s block universe bring us back to the poetry of Parmenides, an empirical discovery by Edward Hubble was to lead to the true transformation of cosmology into astrophysics, a science with predictable results that can be tested. Hubble was working with the 100-inch Hooker telescope at Cal Tech’s Wilson Observatory. He was trying to unravel the riddle of whether recently discovered spiral nebulae lie within or somewhere without the Milky Way. Hubble used measurements of the brightness of a pulsating star called a “Cepheid variable” in the Andromeda spiral nebula to predict the distance of the object from the earth. By calculating the brightness of star, he calculated that Andromeda could not be part of the Milky Way, but must be another distant galaxy. He and an associate were subsequently able to determine from changes in the wavelength of light emitted by the star the velocity of its motion. Doppler shifts (changes in wavelength over time) toward shorter (blue) wavelengths would indicate that the star was moving toward the observer. Doppler shifts toward longer (red) wavelengths would indicate that the star was moving away. In an “epochal” paper in 1919 Hubble and his associate Humason were able to demonstrate that nearly all of the galaxies that they had identified were red-shifted. Hubble and Humason further determined that the further away the galaxy, the greater the “recession” velocity. The expanding universe had been demonstrated.
Hubble’s results would lead Lemaitre and others to the theory of the “Big Bang.” For this story, you will need to turn to Frank’s book, but I want to point out the charming personal story that he tells in the Prologue to his book, which starts with, “The girl in the third row raises her hand and I know I’m in trouble.” Her question, of course, is “But Professor, what happened before the Big Bang?” It is this question which will lead modern cosmologists in the last decades of the previous century to question the theory of the Big Bang. Alternate theories will propose the “Big Crunch,” multiverses, branes and cyclic models reminiscent of ancient Buddhist theory.
Along the way, Frank considers the “A-word of cosmology: the Anthropic Principle . . . . . hovering in the background of cosmological thinking for decades. In its simplest form, it states that the universe and its laws must take a form consistent with our existence within it.” Frank says, “After its introduction in the late 1960s and 1970s, most scientists rejected anthropic thinking, seeing it as so obvious as to be useless or so constrictive as to be an exercise in mysticism.” My own view on this was formed many years ago during a week-long hike in the Lassen Wilderness Area in California. My conclusion: the universe really doesn’t care that we are here. We are lucky to be so. That it should have come to be what it is in order that we should be here seems to me quite absurd.
Frank’s book concludes with a discussion of four “rebels” in modern cosmology: Julian Barbour, Andy Albrecht, Lee Smolin and Roberto Mangabiera Unger. Barbour is a British farmer physicist who has proposed a modern version of Parmenides’s Way of Truth or Dogen’s being-time in his book, The End of Time. “As we live, we seem to move through a succession of Nows and the question is, what are they. . . . We have the strong impression that things have been definite positions relative to each other. I aim to abstract away everything we cannot see (directly or indirectly) and simply keep this idea of many different things coexisting at once. There are simply Nows, nothing more, nothing less.”
While Barbour seems to be a Sceptic, Albrecht was drawn into physics as a Platonist. “I got enthralled by the appendix (in his high school physics textbook) on quantum physics. I just loved the idea that there were deeper laws behind what we see. After all these years it still keeps me going.” But he then started wondering about time. “The problem relates to time and what you decide to call a clock. . . . What does it mean to measure ‘time’? You have to divide the world into the part you want to study and the part you call a clock. When I tried to implement this in my quantum cosmology equations I ran into a big problem.” He calls this the “clock ambiguity.” “Basically, different choices of a clock lead to different kinds of physics.” Albrecht finds that “both time and the laws of physics rested on an ambiguous and arbitrary choice.” In thinking about current theories of multiverses he comes to a sceptical conclusion: “The clock ambiguity implies that the concrete set of physical laws will occur in any given universe until you sit in the middle of it and see what happens.”
The last of the “radicals” considered in Frank’s book are Lee Smolin and Roberto Mangabiera Unger. Smolin is a faculty member at the Perimeter Institute in Toronto and a member of the philosophy department at the University of Toronto. Unger is a philosopher who has associated with Smolin. Smolin’s 2013 book, Time Reborn, covers much the same ground as Frank’s book, telling the story of why classical physics banished time and why it needs to be considered as real. He is in definite opposition to Newton and Einstein’s expulsion of time from physics in their absolute and block universes. He maintains that physics needs to embrace a cosmology that respects the apparent irreversibility of time, the so-called arrow of time.
Just one concept Smolin develops is his question as to why the universe that we live in is so improbable, full of highly ordered things, like stars and us. He makes a distinction between a Leibnizean universe in which the “law of the identity of the indiscernibles” flourishes and a Boltzmanian universe in which everything runs down according to the second law of thermodynamics. His preference for the Leibnizean version for our universe is based on the observation that the second law holds only for closed systems, while the universe in which we live is an open system through which energy flows. This leads him to the conclusion that time is very real and needs to be brought back into physical theory.
A last consideration in our exploration of time by modern physicists will be a brief discussion of a book by H. Dieter Zeh, The Physical Basis of The Direction of Time. Zeh is prominent as the physicist who first proposed the theory of “decoherence” to explain the transition from the quantum to the classical world. His 2002 (Second Edition) book on decoherence is a joint product with E. Joos and others, Decoherence and the Appearance of the a Classical World in Quantum Theory. His time book is an attempt, as implied in the title, to give a “physical” explanation for the arrow of time. He finds not one, but six arrows of time:
- The Second Law
- Quantum Mechanical Measurement
- Exponential Decay
Zeh’s books are not for the timid. He seems to assume that his audience has at least an undergraduate degree in physics. If you are not familiar with the “Dirac notation” of, for example, T|p>=|-p> or that combined with integral calculus (|p>=(2π)^(-1⁄2)∫dq (e)^(-ipq) |q>) you had better become familiar or you will soon be lost. A typical quote: “Other (more or less physical) compensating symmetry operations are known (See Atkinson 2006). For example, the time reversal symmetry of the Schrodinger equation is restored by complex conjugation of the wave function. This can be described by Wigner’s anti-unity operation T which leaves the configuration basis unchanged, Tc|p>=c*|q> for complex numbers c.” Got that?
But what does he think about time? Truth is, I am not completely sure, but I note that in his epilog he repeats a story about Einstein, which is also quoted in Smolin’s book:
“According to Carnap (1963), ‘Einstein said that the problem of the Now worried him considerably. He explained that the experience of the Now means something special for man, something different from the past and the future, but that this important difference does not and cannot occur within physics. That this experience cannot be grasped by science seemed to him a matter of painful but inevitable resignation.'”
Cannot occur within physics? Smolin certainly doesn’t agree. But if true, does that really matter to us humans? Zeh has an answer:
“Memories, in particular, have to be stored in physical form, and are then correlated with sources in their past (they are ‘retarded’). This drastic asymmetry may be sufficient to explain the apparent flow of time once there is a psycho-physical parallelism based on a presumed local moment of awareness. Only this (not necessarily asymmetric) concept of local present is fundamentally subjective, while the asymmetry between past and future directions is part of objective reality. What we usually call the preserved identity of a person (who changes considerably during a lifetime) is ‘in reality’ nothing but a particularly strong and robust ‘causal’ correlation between different local physical states which represent the individual carriers of a subjective present. As pointed out by Einstein and Carnap, it is the here-and-now subjectivity as the center of all awareness that goes beyond objective reality, while it must severely affect our perception of the ‘real world’.”
Well, at least he thinks he has proven that the arrow of time is “part of objective reality.” And if my “retarded” experience of my “center of awareness” is just “subjective” isn’t that what we mean by subjective!
So, Heracleitus or Parmenides, or both? Beginning of time or cyclic time? Is time an illusion or is it real? Or do we go with Gotama and Socrates and concentrate on liberating our minds. I tend toward the latter, but appreciate the manic human determination to make sense of things that we can’t see.
I will give the last word to the poet, Paul Valery:
“A drop of water falling into water barely colors it, and tends to disappear after showing as a pink cloud. That is the physical fact. But suppose now that some time after it has vanished, gone back to limpidity, we should see, here and there in our glass – which seemed once more to hold pure water – drops of wine forming, dark and pure – what a surprise! . . . . We then speak of genius, and contrast it to diffusion.”