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starladyI wrote the following for a course in philosophical theology in November 2006. I should mention at the outset that the paper is a fairly direct attempt to explain the actual physics of time as they are currently understood to my professor, who is a wonderful man and a brilliant philosopher but a very poor physicist (not that I can make any claims to being anything more than an educated layperson in that field). Consequently I wound up talking about Harry Potter and the books of Gene Wolfe in an attempt to illustrate my points comprehensibly. I still enjoy this essay, and I hope readers will too--the suspiciously broad generalizations stop right after the cut, I promise.
In Search of Time, Lost and Otherwise
Before the modern era there was no distinction between science and philosophy; someone who might today be labeled a scientist would have called him or herself, at most, a “natural philosopher.” Thinkers such as Aristotle and Hypatia discussed the nature and composition of the cosmos as readily as they did morality, ethics and the good life. It was not until the modern scientific revolutions of the sixteenth and seventeenth centuries that science and philosophy parted ways, but today the disjunction between them is nearly as profound as that between science and religion.
This state of affairs is unfortunate on a number of levels. Both science and philosophy are engaged in explaining the nature of existence, but the insights of each field are lost on the other. Nowhere are the pernicious consequences of this situation more evident than in the study of time.
One large disjunction can be found in each field’s attempts to explain the nature of time itself. When philosophers attempt to discuss this topic, they will inevitably discuss the “A series” and the “B series,” two interlinked notions which were formulated by James McTaggart early in the last century. It is nearly as difficult to understand these statements as it is to explain them, but the A series refers to statements which invoke the past, present and future, while the B series speaks of time in terms of events in time and their relation to each other, rather than to any external time-referent concepts such as the “past.” (Schlesinger 26-9) Considerable debate rages as to which of these two series are independently valid, or whether one is dependent on the other.
In his book Aspects of Time George Schlesinger contrasts the McTaggart view of time with that of Bertrand Russell, who claimed that the passage of time was essentially an illusion. In his discussion of the two viewpoints Schlesinger declares that “the strongest motive for preferring McTaggart’s view to Russell’s is the deeply entrenched impression […] of the transiency of time and the generally held belief that time is moving” (30). Schlesinger is certainly correct to appeal to experience in his discussion of the passage of time, especially since the very universality of the experience of time and change is probably its strongest support. But Schlesinger also declares that
Here Schlesinger seems, at best, to be overstating the case. While philosophy certainly has a unique viewpoint from which to examine time, it is by no means the only viewpoint. Physics, for example, is endowed with similar explanatory powers, and it has the advantage over philosophy insomuch as its assertions are usually verifiable through experimentation, or at least are founded upon mathematics.
Reading Brian Greene’s book The Fabric of the Cosmos leaves one with the overwhelming impression that rather than discussing the nature of time, philosophers are hung up on the nature of human experience of time. Perhaps the strongest reason for this argument is captured by Greene’s statement that “The overarching lesson that has emerged from scientific inquiry over the last century is that human experience is often a misleading guide to the true nature of reality” (5). But since philosophers like Schlesinger have explicitly discounted the insights of physics, they have no tools left but human experience.
Surprisingly, modern physics takes a much more Russellian stance toward time than might be expected: time does not ‘flow.’ “If you buy the notion that reality consists of the things in your freeze-frame mental image right now,” Greene writes, “and if you agree that your now is no more valid than the now of someone located far away in space who can move freely, then reality encompasses all of the events in spacetime” (138-9). In other words (and Greene quotes Einstein to this effect), the past, present and future are only “an illusion, however persistent” (139). Thus there is no flow in time, only within the human mind:
It seems Greene is right when he declares that “Assessing existence while failing to embrace the insights of modern physics would be like wrestling in the dark with an unknown opponent” (5). Greene is careful to note that his explanation may not be definitive: “Time is a subtle subject and we are far from understanding it fully,” he cautions (141).
Another philosophical controversy concerns whether the past actually exists. One method of confirming that it does is suggested by Schlesinger, who again appeals to the commonality of experience: if we wish to know whether it rained yesterday, the fact that everyone on campus has a very clear memory of the rain, as well as the fact that ground is wet today, should lead us to conclude not only that it rained yesterday but, by the verificationist principle, that the past also exists.
In essence, Greene agrees, although he has a good deal more to prove than the mere existence of the past. One consequence of the discussion above is that time is not embedded within the physical laws which are known to govern the universe; it is just as likely, according to Newton, that time’s arrow should point backward as that it point forward, as we feel it does. In other words, time is symmetrical.
This is a conundrum. As Greene notes, the second law of thermodynamics (entropy increases) is often used as a physics stand-in for change and for the passage of time. But since the laws of thermodynamics are time-blind, it is actually just as likely that systems were more disordered in the past as that they will be more disordered in the future. It thus seems impossible to prove that the melted water in my glass was ice cubes half an hour ago. My memory of the ice cubes is false.
Luckily, physics won’t leave us in this quagmire for long, for of course if it were true that the universe suddenly sprang from disorder to order at this very moment (and at this moment, and now at this moment, ad infinitum) the laws of physics would be invalid in much the same fashion as, according to Schlesinger, our common experience would have been if we had believed that yesterday’s rain was merely a mass hallucination and that the past was nonexistent.
The only way to square the circle is to realize that all physical systems today are causally dependent on the original state of the universe: the big bang (with Greene, we should note that big bang theory “says nothing at all about time zero itself […] the big bang leaves out the bang” [272]). And in order for my memory of the frozen ice cubes to be trustworthy, the big bang must have been a highly ordered state, however hugely unlikely. “The future,” Greene concludes, “is indeed the direction of increasing entropy. The arrow of time […] began its flight in the highly ordered, low-entropy state of the universe at its inception” (175). The past, in other words, exists because the big bang was a highly ordered state.
Of course, this still leaves us with the question of the future. There are some philosophers who believe that it does not exist, but this may be a bit overeager. Certainly there is a sense in which the future is ‘unreal’ in a way the past is not, in that we have not yet directly perceived or experienced it. But to say that it doesn’t exist, in the same way that a table doesn’t exist beyond its edge, is false in my view. As Schlesinger notes, “These predicates [past, present, future] may be assigned simultaneously to the same event, for it can truly be said that an event which is taking place at this very moment will be past in the future and has been future in the past” (48). The key thing to remember is that, to repeat Greene, “Every moment is:” The totality of spacetime is reality. The future always exists relative to the ‘privileged moment’ which we experience as beings in time and which we call the ‘now.’ But while this moment is privileged for us, it is by no means privileged for those who will inhabit time one hundred or one thousand years from now. For them our now is the past, while our future for them is the present.
While English is a wonderful language, there are some respects in which it is simply inadequate, and I fear that precise discussion of time is one of them. It may be easier to illustrate my point by quoting a brain-bending book by Gene Wolfe, The Citadel of the Autarch. In the passage that follows, the protagonist Severian is discussing time and experience with Master Ash, a sort of chrono-hermit from Severian’s future.
Master Ash can tell Severian what is in Severian’s future because for him it is past, but he cannot speak about the future because he has not yet experienced it. Both of them are inextricably bound to their own personal nows, their privileged moments. Although they are within the same ‘slice’ of spacetime as they converse (to use Greene’s metaphorical terminology), their nows are not the same.
Wolfe is a phenomenal writer, but his fiction boggles in much the same way relativity does, and when I first read the passage above I had to take a break to attempt to wrap my mind around it. Nor will I pretend that I succeeded on my first try. But there is at least one more example which illustrates my point and which is probably much more familiar. I am speaking, of course, of the denouement of J. K. Rowling’s Harry Potter and the Prisoner of Azkaban.
At the end of the story it appears as if everything has gone wrong and will stay that way: Harry Potter’s godfather Sirius Black is minutes away from having his soul sucked out through his mouth, the innocent hippogriff Buckbeak has been executed on trumped-up charges, and the traitor Wormtail has escaped. But Professor Dumbledore tells Harry and his friend Hermione that “What we need is more time” (393), and Hermione, whose enthusiasm for education knows no bounds, has a way to get it.
Hermione uses her Time-Turner to send her and Harry back three hours into the past. “Are you telling me,” Harry asks, “that we’re here in this cupboard and we’re out there too?” (395) While in their past, their primary concern is to keep from being seen by their past-selves, as Hermione explains: “Nobody’s supposed to change time, nobody! […] Professor McGonagall told me what awful things have happened when wizards have meddled with time….Loads of them ended up killing their past or future selves by mistake!” (398-9)
Harry comments fervently that “This is the weirdest thing we’ve ever done,” (398), and even for a wizard, he’s probably right. As their time travel adventure unfolds it becomes apparent that, while they thought Buckbeak had been executed, they had in reality already saved him. This illustrates one of Greene’s most important points about time travel: the laws of physics do not rule it out, but there is never a time in which the time traveler has not traveled to the past. A time traveler who has gone back in time is never impresent at that moment in time. She was always there; her presence does not change “unmeddled” time to “meddled” time: time was always meddled. (Greene 452-5)
One reason philosophers are opposed to the existence of the future is its probable limitations on free will: if the future already exists, how can our actions be independent? But I do not think that this is as big a problem as it seems. We are bound at every moment in time, as I said above, to our own privileged moments. Even though the future exists, we can have no knowledge of it; indeed, I could define ‘the future’ as ‘time of which we have no knowledge.’ Our ignorance preserves free will because, even though the future exists, we can’t know it, and thus our actions are as good as free. To someone in the past, our actions are fixed and determinate, but for us the future is an undiscovered country of possibility.
Harry learns this for himself in a particularly poignant fashion. Prior to winding up in the hospital wing discussing time travel with Dumbledore, he, Sirius, Hermione and Ron were surrounded by Dementors (the very same creatures which suck souls) down by the lake. It takes a very difficult charm, the Patronus charm, to ward off Dementors, and a powerful wizard to perform it. Harry’s own attempts at a Patronus fail, and he knows he is going to die. But then, beyond hope, he sees someone who looks like his father standing across the lake, whose stag-shaped Patronus scatters the Dementors like ninepins before Harry passes out.
Hermione, while they wait in their past to rescue Sirius, tells Harry flatly that his father is dead, and while Harry doesn’t deny this, he continues to believe what he thought he saw. It’s not until it’s almost too late to save his past self and his friends that he realizes that he didn’t see James Potter: he saw himself. He pulls out his wand and performs the Patronus charm perfectly.
Even though, when Harry was being attacked by the Dementors, his future self saved him, his ignorance of the identity of his savior preserved his free will until he came to be standing by the lake, faced with the choice to interfere in his past self’s fate or not. And since he had already saved himself, the choice was obvious.
In this essay I have reviewed several controversies about the nature of time from philosophical and scientific viewpoints. I gave much greater primacy to Brian Greene’s physics-centered account of the nature of time, since I find the A and B statement debate recondite, but it is my firm belief that the best philosophy is done in unification with science. If we are to seek the excellence of human existence in all its aspects, it can only be detrimental to disregard the insights of science where they may apply, as it is surely a field in which human ingenuity has excelled. But at the same time, as Greene says, “Camus rightly chose life’s value as the ultimate question” (5), and becoming too wrapped up in science at the cost of philosophy is as impoverishing as the opposite condition. Instead, we should seek a balanced perspective like that of Master Ash: “The distinction you mention no longer holds. Religion and science have always been matters of faith in something. It is the same something” (288).
Works Cited
Before the modern era there was no distinction between science and philosophy; someone who might today be labeled a scientist would have called him or herself, at most, a “natural philosopher.” Thinkers such as Aristotle and Hypatia discussed the nature and composition of the cosmos as readily as they did morality, ethics and the good life. It was not until the modern scientific revolutions of the sixteenth and seventeenth centuries that science and philosophy parted ways, but today the disjunction between them is nearly as profound as that between science and religion.
This state of affairs is unfortunate on a number of levels. Both science and philosophy are engaged in explaining the nature of existence, but the insights of each field are lost on the other. Nowhere are the pernicious consequences of this situation more evident than in the study of time.
One large disjunction can be found in each field’s attempts to explain the nature of time itself. When philosophers attempt to discuss this topic, they will inevitably discuss the “A series” and the “B series,” two interlinked notions which were formulated by James McTaggart early in the last century. It is nearly as difficult to understand these statements as it is to explain them, but the A series refers to statements which invoke the past, present and future, while the B series speaks of time in terms of events in time and their relation to each other, rather than to any external time-referent concepts such as the “past.” (Schlesinger 26-9) Considerable debate rages as to which of these two series are independently valid, or whether one is dependent on the other.
In his book Aspects of Time George Schlesinger contrasts the McTaggart view of time with that of Bertrand Russell, who claimed that the passage of time was essentially an illusion. In his discussion of the two viewpoints Schlesinger declares that “the strongest motive for preferring McTaggart’s view to Russell’s is the deeply entrenched impression […] of the transiency of time and the generally held belief that time is moving” (30). Schlesinger is certainly correct to appeal to experience in his discussion of the passage of time, especially since the very universality of the experience of time and change is probably its strongest support. But Schlesinger also declares that
The fascinating thing about this controversy is that although it is by no means about some remote aspect of the world—for on the contrary it concerns a most immediate and constantly encountered feature of the empirical universe—it nevertheless cannot be resolved within the scope of ordinary observation or of scientific experimentation. Only through philosophical analysis does there seem to be any hope of making some progress toward the resolution of this fundamental controversy […]. (24)
Here Schlesinger seems, at best, to be overstating the case. While philosophy certainly has a unique viewpoint from which to examine time, it is by no means the only viewpoint. Physics, for example, is endowed with similar explanatory powers, and it has the advantage over philosophy insomuch as its assertions are usually verifiable through experimentation, or at least are founded upon mathematics.
Reading Brian Greene’s book The Fabric of the Cosmos leaves one with the overwhelming impression that rather than discussing the nature of time, philosophers are hung up on the nature of human experience of time. Perhaps the strongest reason for this argument is captured by Greene’s statement that “The overarching lesson that has emerged from scientific inquiry over the last century is that human experience is often a misleading guide to the true nature of reality” (5). But since philosophers like Schlesinger have explicitly discounted the insights of physics, they have no tools left but human experience.
Surprisingly, modern physics takes a much more Russellian stance toward time than might be expected: time does not ‘flow.’ “If you buy the notion that reality consists of the things in your freeze-frame mental image right now,” Greene writes, “and if you agree that your now is no more valid than the now of someone located far away in space who can move freely, then reality encompasses all of the events in spacetime” (138-9). In other words (and Greene quotes Einstein to this effect), the past, present and future are only “an illusion, however persistent” (139). Thus there is no flow in time, only within the human mind:
[…] The concept of change has no meaning with respect to a single moment in time. […] A particular moment can no more change in time than a particular location can move in space […]. Instead, every moment is illuminated, and every moment remains illuminated. Every moment is. Under close scrutiny, the flowing river of time more closely resembles a giant block of ice with every moment forever frozen into place. (141)
It seems Greene is right when he declares that “Assessing existence while failing to embrace the insights of modern physics would be like wrestling in the dark with an unknown opponent” (5). Greene is careful to note that his explanation may not be definitive: “Time is a subtle subject and we are far from understanding it fully,” he cautions (141).
Another philosophical controversy concerns whether the past actually exists. One method of confirming that it does is suggested by Schlesinger, who again appeals to the commonality of experience: if we wish to know whether it rained yesterday, the fact that everyone on campus has a very clear memory of the rain, as well as the fact that ground is wet today, should lead us to conclude not only that it rained yesterday but, by the verificationist principle, that the past also exists.
In essence, Greene agrees, although he has a good deal more to prove than the mere existence of the past. One consequence of the discussion above is that time is not embedded within the physical laws which are known to govern the universe; it is just as likely, according to Newton, that time’s arrow should point backward as that it point forward, as we feel it does. In other words, time is symmetrical.
This is a conundrum. As Greene notes, the second law of thermodynamics (entropy increases) is often used as a physics stand-in for change and for the passage of time. But since the laws of thermodynamics are time-blind, it is actually just as likely that systems were more disordered in the past as that they will be more disordered in the future. It thus seems impossible to prove that the melted water in my glass was ice cubes half an hour ago. My memory of the ice cubes is false.
Luckily, physics won’t leave us in this quagmire for long, for of course if it were true that the universe suddenly sprang from disorder to order at this very moment (and at this moment, and now at this moment, ad infinitum) the laws of physics would be invalid in much the same fashion as, according to Schlesinger, our common experience would have been if we had believed that yesterday’s rain was merely a mass hallucination and that the past was nonexistent.
The only way to square the circle is to realize that all physical systems today are causally dependent on the original state of the universe: the big bang (with Greene, we should note that big bang theory “says nothing at all about time zero itself […] the big bang leaves out the bang” [272]). And in order for my memory of the frozen ice cubes to be trustworthy, the big bang must have been a highly ordered state, however hugely unlikely. “The future,” Greene concludes, “is indeed the direction of increasing entropy. The arrow of time […] began its flight in the highly ordered, low-entropy state of the universe at its inception” (175). The past, in other words, exists because the big bang was a highly ordered state.
Of course, this still leaves us with the question of the future. There are some philosophers who believe that it does not exist, but this may be a bit overeager. Certainly there is a sense in which the future is ‘unreal’ in a way the past is not, in that we have not yet directly perceived or experienced it. But to say that it doesn’t exist, in the same way that a table doesn’t exist beyond its edge, is false in my view. As Schlesinger notes, “These predicates [past, present, future] may be assigned simultaneously to the same event, for it can truly be said that an event which is taking place at this very moment will be past in the future and has been future in the past” (48). The key thing to remember is that, to repeat Greene, “Every moment is:” The totality of spacetime is reality. The future always exists relative to the ‘privileged moment’ which we experience as beings in time and which we call the ‘now.’ But while this moment is privileged for us, it is by no means privileged for those who will inhabit time one hundred or one thousand years from now. For them our now is the past, while our future for them is the present.
While English is a wonderful language, there are some respects in which it is simply inadequate, and I fear that precise discussion of time is one of them. It may be easier to illustrate my point by quoting a brain-bending book by Gene Wolfe, The Citadel of the Autarch. In the passage that follows, the protagonist Severian is discussing time and experience with Master Ash, a sort of chrono-hermit from Severian’s future.
“I am not a prophet,” answered Master Ash, “nor was he. No one can know the future. We are speaking of the past.”
I was angry again. “You told me this was only a few lifetimes away.”
“I did. But you, and this scene, are past events for me.”
“I am not a thing of the past! I belong to the present.”
“From your own viewpoint you are correct. But you forget I cannot see you from your viewpoint. […] As it is, I read these old centuries like books. I hear the voices of the long dead, yours among them. You think that time is a single thread. It is a weaving, a tapestry that extends forever in all directions. I follow a thread backward. You will trace a color forward […].”
Not knowing what to say, I could only mutter that I had conceived of time as a river.
“Yes—you came from Nessus, did you not? And that was a city built about a river. But it was once a city by the sea, and you would do better to think of time as a sea. The waves ebb and flow, and the currents run beneath them.”
(288)
Master Ash can tell Severian what is in Severian’s future because for him it is past, but he cannot speak about the future because he has not yet experienced it. Both of them are inextricably bound to their own personal nows, their privileged moments. Although they are within the same ‘slice’ of spacetime as they converse (to use Greene’s metaphorical terminology), their nows are not the same.
Wolfe is a phenomenal writer, but his fiction boggles in much the same way relativity does, and when I first read the passage above I had to take a break to attempt to wrap my mind around it. Nor will I pretend that I succeeded on my first try. But there is at least one more example which illustrates my point and which is probably much more familiar. I am speaking, of course, of the denouement of J. K. Rowling’s Harry Potter and the Prisoner of Azkaban.
At the end of the story it appears as if everything has gone wrong and will stay that way: Harry Potter’s godfather Sirius Black is minutes away from having his soul sucked out through his mouth, the innocent hippogriff Buckbeak has been executed on trumped-up charges, and the traitor Wormtail has escaped. But Professor Dumbledore tells Harry and his friend Hermione that “What we need is more time” (393), and Hermione, whose enthusiasm for education knows no bounds, has a way to get it.
Hermione uses her Time-Turner to send her and Harry back three hours into the past. “Are you telling me,” Harry asks, “that we’re here in this cupboard and we’re out there too?” (395) While in their past, their primary concern is to keep from being seen by their past-selves, as Hermione explains: “Nobody’s supposed to change time, nobody! […] Professor McGonagall told me what awful things have happened when wizards have meddled with time….Loads of them ended up killing their past or future selves by mistake!” (398-9)
Harry comments fervently that “This is the weirdest thing we’ve ever done,” (398), and even for a wizard, he’s probably right. As their time travel adventure unfolds it becomes apparent that, while they thought Buckbeak had been executed, they had in reality already saved him. This illustrates one of Greene’s most important points about time travel: the laws of physics do not rule it out, but there is never a time in which the time traveler has not traveled to the past. A time traveler who has gone back in time is never impresent at that moment in time. She was always there; her presence does not change “unmeddled” time to “meddled” time: time was always meddled. (Greene 452-5)
One reason philosophers are opposed to the existence of the future is its probable limitations on free will: if the future already exists, how can our actions be independent? But I do not think that this is as big a problem as it seems. We are bound at every moment in time, as I said above, to our own privileged moments. Even though the future exists, we can have no knowledge of it; indeed, I could define ‘the future’ as ‘time of which we have no knowledge.’ Our ignorance preserves free will because, even though the future exists, we can’t know it, and thus our actions are as good as free. To someone in the past, our actions are fixed and determinate, but for us the future is an undiscovered country of possibility.
Harry learns this for himself in a particularly poignant fashion. Prior to winding up in the hospital wing discussing time travel with Dumbledore, he, Sirius, Hermione and Ron were surrounded by Dementors (the very same creatures which suck souls) down by the lake. It takes a very difficult charm, the Patronus charm, to ward off Dementors, and a powerful wizard to perform it. Harry’s own attempts at a Patronus fail, and he knows he is going to die. But then, beyond hope, he sees someone who looks like his father standing across the lake, whose stag-shaped Patronus scatters the Dementors like ninepins before Harry passes out.
Hermione, while they wait in their past to rescue Sirius, tells Harry flatly that his father is dead, and while Harry doesn’t deny this, he continues to believe what he thought he saw. It’s not until it’s almost too late to save his past self and his friends that he realizes that he didn’t see James Potter: he saw himself. He pulls out his wand and performs the Patronus charm perfectly.
“What did you do?” [Hermione] said fiercely. […]
“I just saved all our lives,” said Harry. […]
Hermione listened to what had just happened with her mouth open yet again.
“Did anyone see you?”
“Yes, haven’t you been listening? I saw me but I thought I was my dad! It’s okay!”
“Harry, I can’t believe it….You conjured up a Patronus that drove away all those Dementors! That’s very, very advanced magic….”
“I knew I could do it this time,” said Harry, “because I’d already done it….Does that makes sense?”
“I don’t know—”
(412)
Even though, when Harry was being attacked by the Dementors, his future self saved him, his ignorance of the identity of his savior preserved his free will until he came to be standing by the lake, faced with the choice to interfere in his past self’s fate or not. And since he had already saved himself, the choice was obvious.
In this essay I have reviewed several controversies about the nature of time from philosophical and scientific viewpoints. I gave much greater primacy to Brian Greene’s physics-centered account of the nature of time, since I find the A and B statement debate recondite, but it is my firm belief that the best philosophy is done in unification with science. If we are to seek the excellence of human existence in all its aspects, it can only be detrimental to disregard the insights of science where they may apply, as it is surely a field in which human ingenuity has excelled. But at the same time, as Greene says, “Camus rightly chose life’s value as the ultimate question” (5), and becoming too wrapped up in science at the cost of philosophy is as impoverishing as the opposite condition. Instead, we should seek a balanced perspective like that of Master Ash: “The distinction you mention no longer holds. Religion and science have always been matters of faith in something. It is the same something” (288).
- Greene, Brian. The fabric of the cosmos. New York: Alfred A. Knopf, 2004.
- Rowling, J. K. Harry Potter and the prisoner of Azkaban. New York: Scholastic, 1999.
- Schlesinger, George. Aspects of time. Indianapolis, IN: Hackett Publishing Co., 1980.
- Wolfe, Gene. Sword & citadel. New York: Orb Books, 1994.