As far as I know (and I’d love to hear otherwise), one of the earliest examples of literary characters with incompatible arrows of time (as opposed to a simple reversed-chronology narrative) is from Lewis Carroll (no relation), in Through the Looking Glass. When Alice first meets the White Queen, she learns that the Queen experiences time backwards.
`I don’t understand you,’ said Alice. `It’s dreadfully confusing!’
`That’s the effect of living backwards,’ the Queen said kindly:
`it always makes one a little giddy at first —
`Living backwards!’ Alice repeated in great astonishment. `I never heard of such a thing!’
` — but there’s one great advantage in it, that one’s memory works both ways.’
`I’m sure MINE only works one way.’ Alice remarked. `I can’t remember things before they happen.’
`It’s a poor sort of memory that only works backwards,’ the Queen remarked.
I agree, and I wish someone would do something about that. Carroll doesn’t emphasize this device much in the book, but does offer one classic illustration of the phenomenon.
Alice was just beginning to say `There’s a mistake somewhere-,’ when the Queen began screaming so loud that she had to leave the sentence unfinished. `Oh, oh, oh!’ shouted the Queen, shaking her hand about as if she wanted to shake it off. `My finger’s bleeding! Oh, oh, oh, oh!’
Her screams were so exactly like the whistle of a steam-engine, that Alice had to hold both her hands over her ears.
`What IS the matter?’ she said, as soon as there was a chance of making herself heard. `Have you pricked your finger?’
`I haven’t pricked it YET,’ the Queen said, `but I soon shall – – oh, oh, oh!’
`When do you expect to do it?’ Alice asked, feeling very much inclined to laugh.
`When I fasten my shawl again,’ the poor Queen groaned out: `the brooch will come undone directly. Oh, oh!’ As she said the words the brooch flew open, and the Queen clutched wildly at it, and tried to clasp it again.
`Take care!’ cried Alice. `You’re holding it all crooked!’ And she caught at the brooch; but it was too late: the pin had slipped, and the Queen had pricked her finger.
`That accounts for the bleeding, you see,’ she said to Alice with a smile. ‘Now you understand the way things happen here.’
`But why don’t you scream now?’ Alice asked, holding her hands ready to put over her ears again.
`Why, I’ve done all the screaming already,’ said the Queen. `What would be the good of having it all over again?’
Both Alice’s Adventures in Wonderland and Through the Looking Glass rely on nonsense to tell a gripping story. Reversing an individual arrow of time is sufficiently nonsensical to qualify as automatically amusing, but also provocative. Why does everyone remember the same direction of time, anyway? (Actually that one’s not hard to answer. If two systems with incompatible arrows were to noticeably interact, the one with more degrees of freedom would swamp the other one and quickly “correct” its arrow of time. No being that “remembered the future” would survive very long in the real world.)
Enantiomorphy has its applications in biology, physics and geometry. I think it important to remember that science is observational and descriptive. We observe the universe a certain way from our frame of reference. It makes sense that way, and following empirically, we deduce (and find testable and reducable to a technology) the laws of physics and their mathematical framework…which by the way and by definition are logically consistent.
When we assume that the universe everywhere must be as we observe it, we are making a very large assumption indeed! L. Carroll was a pre-Einsteinian mathmetician, as well as a teacher and story-teller. He used his story telling ability, not only to entertain children, but to challenge the basis of our assumed ideas about the way the universe is…or more profoundly, seems to us.
The reason Carroll challenges our assumtions is his knowledge of the reality of dualism in the mathematical framework by which we define (and precisely measure) our world and derive our technology.
Might not the universe be more than what we observe? The math of SR/GR/QM- even the basic “mirror” geometry of Schwarzschild certainly imply that the universe may be very different from the way we observe it…the math leads us down a winding, counterintuitive and seemingly bizarre path which leads to Schwarzschild, Dirac, Bohr-and Einstein.
That same path leads to determinism in a universe which seems anything BUT deterministic, and a universe with the foundational quality of a quite rigid…quasi-static, “engineering” stability.
A very interesting and challenging post…
Isn’t the wizard Marlin who was the advisor of king Arthur an earlier example of someone living backwards in time, or do I get the literature history wrong… ?
I have the following quote on my bulletin board: “The best book on programming for the layman is “Alice in Wonderland”, but that’s because it’s the best book on anything for the layman.” I don’t know who to attribute it to (probably some Berkeley-based Unix wizard), but the Alice series is remarkably applicable to so many fields that I have to believe there is some truth to the quote.
Isn’t the wizard Marlin who was the advisor of king Arthur an earlier example of someone living backwards in time, or do I get the literature history wrong… ?
That was apparently an innovation of T.H. White in The Once and Future King (1958).
Whoops, 1958 was just the date in which The Once and Future King was completed. Big chunks of it (including some of the Merlin stuff) were published before that. (Patchy memory plus Wikipedia = semblance of knowledge!)
Anyhow, Lewis Carroll predates it by a few decades.
“Lewis Carroll predates it ”
So Carroll was a predator. I knew it!
> If two systems with incompatible arrows were to interact, the one with more degrees of freedom would swamp the other one (..)
Is that physics or nonsense?
And if the queen has both ways memory, wouldn’t she have “more” degrees of freedom.
Why does everyone remember the same direction of time, anyway?
A biologist suggests: Maybe because our thoughts and memories are part of those physical systems that are apparently subject to the arrow of time? In all of the examples you have described, extra-mental events run backwards in time, but the character was somehow able to perceive and think about these in a forward manner. What would experiencing a thought backwards even feel like?
Sean-
Check out Faulkner’s “Sound and the Fury”. The first part is told from the point of view of an autistic (or retarded) man-child who has no concept of time–past or present. The section of the book is one of the hardest in all of literature.
Josh
Mind/brain duality versus e.g. emergentism is interesting but doesn’t seem to have much predictive power in cosmology.
The three Incompatible Arrows posts all seem to revolve around the question of whether an actor/observer relationship is even possible between entities that have a very different view of the pastness and futureness of other events they each observe at some point.
Let’s clump together particles into a pair of reasoning cosmologists, one of which observes evidence of a universe expanding from a surface of last scattering, and the other of which sees a contracting universe heading towards a hot dense coupling phase. The individual particles “travelling along together” with each cosmologist share compatible views of pastness/futureness, in that they receive signals from their past and transmit signals into their future. The cosmologists perform their own physical experiments locally, obtaining results consistent with their best theories about how physics operate.
Are the theories held by each cosmologist comparable?
Can we, sharing the view of the first scientist, make predictions about what the “backwards” (to us) scientist’s theories are like?
If there were such a scientist, could we interact at all? Could we communicate? What would be the effects of the communication from our perspective, and from the other perspective?
Or, is any interaction with any “backwards-moving” entity, whether reasoning scientist or particle, “forbidden”?
The fictional treatments in these three posts are interesting because the communication is all consistent with one character’s past->future direction, even if that character’s counterparties occasionally or usually have a very different view of pastness/futureness.
Alice moves like us, the Queen communicates with Alice in Alice-friendly forward-moving expressions. Billy moves like us except when he jumps around, but everyone he interacts with moves like us (and Billy) between jumps. In fictional works that sound like Amis’s (which I haven’t read) most backwards-moving characters tend to communicate forwardly from time to time, or have forward-moving “vignettes” from the persepective of a forward-moving character. Red Dwarf’s Backwards http://en.wikipedia.org/wiki/Backwards_(Red_Dwarf_episode) is constructed this way.
Unfortunately the people in the backwards/forwards interactions in fictional treatments don’t seem to behave realistically as collections of unthinking particles/fields/whatevers. How does the weak nuclear force work in the backwards-moving people’s bodies, for example? Do they experience spontaneous nuclear integrations?
One point I’m wondering about is how a writer could take on a reasonably hard science fiction treatment of a backwards-moving cosmologist. Maybe a conventional Earth cosmologist who “switches” the pastness/futureness of some reasonably isolated environment (like a space ship) she’s embedded in? Does the “switched” scientist still observe Galilean invariance? (“Yes” would be useful for plot purposes, followed by “what’s the view out the window?”, but “no” is probably the more interesting answer for a cosmologist thinking about T-symmetry. 🙂 )
I love this site!
Often I feel too inadequate to post.
But, this subject fascinates me. I have read “Wu Li Masters” and “A Brief History of Time” a number of times.
When this “time” question comes up, I never fail to try and imagine an environment in which time and the other three dimensions don’t exist (pre-Big-Bang).
The fact that my brain can even conceive of a realm that would exclude the existence of the very brain imagining it is endlessly fascinating.
I must wonder how much we DON’T know.
I think “Tristram Shandy”, an 18th century novel by Laurence Sterne, involves some time incompatibility, for comical effect, between author and reader.
There may be some other examples at http://www.philobiblon.com/isitabook/literature/index.html.
Check out Strugatsky brothers classic “Monday Begins on Saturday”. There is a character that is in fact two persons – one living along the normal time arrow, the other in reverse. The catch was that the skip back in time happened only at midnight, during the day the time was going in the same direction (so the person look normal to normal people)
Dear Sean, These are amusing posts, but I am worried
about what precisely you mean by the last comment:
presumably it is not a statement about a consequence
of the laws of physics, but instead a philosophical inference?
I don’t mean that to be a derogatory term, just one
that distinguishes it from a theoretical inference
from physical law, which you appeared to strongly imply
it was — was that your intent?
RS said,
“Why does everyone remember the same direction of time, anyway?
A biologist suggests: Maybe because our thoughts and memories are part of those physical systems that are apparently subject to the arrow of time? In all of the examples you have described, extra-mental events run backwards in time, but the character was somehow able to perceive and think about these in a forward manner. What would experiencing a thought backwards even feel like?”
This is very thoughtful reasoning. Even in a dual 7D and up quasi-static model of the universe fully incorporating the duality of SR/GR/QM and Schwarzschild, it could well be that there is no actua experience of the part of the universe which exists in decreasing thermal and increasing informational entropy (the “younging” “hemisphere”). In such a universe, though foundationally dual, our conscious existence would eternally remain on the “same side” IE, we would “die” (actually only others are observed to experience death, not ourselves) and then gradually awaken to our own childhood, increase in awareness again, die and repeat the process eternally.
The caveat is the fact that photons do work…lower informational entropy- and likely spin in a certain direction in the 4D particulate cross-section (Schwarzschild “hemisphere”) which we observe. Anything which collectively (and individually) spins in a certain direction relative to our reality could very well be observed to spin in the opposite direction from other, equally particulate coordinates in the system. If our universe exists this way, there might well be an “Allice in Wonderland” 4D cross-section of the universe where thermal entropy would be observed to decrease and informational entropy would increase.
In such a universe, our consciousness would not cease or radically change at death, but would rather “shift”…we would become in some way which would take some “getting used to”, aware of another side, where the physics and way of life would be different. We would become more childlike and then ultimately and eternally become re-aware of our childhood and maturing experience in the reality we all “now” inhabit.
I think it appropriate that we not only remember Lewis Carroll, but also the late Arthur Clarke and Carl Sagan, all of whom, in very provocative ways, popularized some of the implications of the standard cosmological models of our era.
blanton, it is a consequence of the laws of physics. We are only able to remember the past because the entropy was lower back then. When two macroscopic systems interact, even if the smaller one has delicately-tuned correlations in its constituents so that its entropy decreases toward the future (as defined by the larger system), those correlations would rapidly be destroyed by the interactions with the larger system. You can’t maintain interacting systems with opposed arrows of time.
Maybe the problems encountered in these narrative explorations of temporal disconnect might lead to a reconsideration of time as a dimensional phenomena that enables traveling about as if it were a form of space. That the rate of activity is influenced by physical context makes devices use to measure this rate of activity(clocks) equally dependent doesn’t mean the rate of activity is subject to whim. The amounts of energy and dislocation required to effect even the most minimal change is large. Why is it that some plot devices and flights of fancy, such as time travel, or reversed time, are more credible than others, such as omnipotent deities, resurrection or talking, burning bushes? Maybe Jesus hit a time loop.
“No being that remembered the future would survive very long in the real world”
No. But how about a world where all physical processes operated in reverse?
Physical systems now absorb energy and become more organised with time, prexistent biological forms devolve.
The “past” of such an organism would be our “future”.
Would an intelligent being, somewhere in the “anthropic” phase of such a universe, actually be able to distinguish one arrow of time from its reverse?
Think out the implications consistently all the way through and I think the answer is no.
Sean, I guess what I am wondering is whether either of your
statements (“We are only able to remember the past because
the entropy was lower back then”, or “You can’t maintain interacting
systems with opposed arrows of time”) are summaries of results
from the vetted physics literature. I’d be very surprised if there is
a clean experimental test of either statement; I’d be less surprised
if there was a theoretical calculation supporting the latter one.
I probably *believe* either statement as reasonable, but that’s
different than them being established consequences of the laws of
physics. I admit I’ve never searched the literature for this sort
of thing, so I stand ready to be corrected with the appropriate
references.
Enough of these metaphysical speculations. Here’s all ye on earth know, or need to know, about time:
http://www.youtube.com/watch?v=6nuiIqMQ4sA
(19) blanton…
His wording was a pretty naked use of the anthropic principle, but in essence his argument is based on using measurements of entropy as a privileged clock since it is always increasing at the largest scales.
This is reasonable when one considers a phase in which the universe was a hot, dense, nearly ideal gas, as WMAP/COBE/BOOMERANG data have been suggesting for some time, which has more recently been expanding to fill the growing “container” provided by the metric expansion of spacetime, cooling on the largest scales as it grows.
This is in line with local explorations of the second law of thermodynamics. Shown a film clip of gas in a box with no indication of whether it was showing the explosion of gas from a compact form, or the condensation of a large volume of gas into a small pellet. Normally we would choose as the initial conditions the most compact, least uniform end of the clip, and as the final conditions the least compact, most thermally equilibriated filling of the box.
We run into trouble if we end up with a film clip where there is no obvious change in entropy when running the clip in either direction. We also run into problems if the entropy at both ends of the clip is substantially similar.
Observations preclude a steady state universe, so the first film-clip trouble isn’t applicable cosmologically. There is compelling evidence against a future “big crunch”, which eliminates the second trouble too.
Thus we have some conditions at or very near the Big Bang which lead to a Universe whose overall geometry leads to a clearly defined directionality in our entropy clock. Less entropy in one “direction” (pastwards), more in the other direction (futurewards).
That we “remember” anything at all is also due to the early conditions of the Universe in that the formation of large structures — galaxies, stars, our planet, our brains — fell out of the distribution of energies and the behaviour of spacetime at or very soon after the bang.
Thinking about why our memories seem well aligned with an entropy-based Universal clock is interesting, but to me not obviously germane to other distant not-human-memory-equipped users of the same idea of clocking things relative to the overall entropy of the observable universe, with futureward being the direction of increasing entropy.
Most of this arrow of time stuff is an attempt to reason about the initial conditions of the observable universe, and especially about the amazing orderliness suggested to us by observation of the CMBR and also of increasingly ancient astronomical structures.
As to theoretical calculations… Cosmic Inflation is consistent with very low entropy initial conditions. That’s the first argument in a nutshell, just reframed without the anthropic reasoning about memory. “You can’t maintain interacting systems with opposed arrows of time” seems to fit with various ideas involving destructive interference wiping out the initial quantum fluctuations that lead to a change in entropy in the first place (whichever direction entropy moves in). Sean’s “the one with more degrees of freedom would swamp the other one and quickly “correct” its arrow of time” is a very terse way of saying that there are some events that are possible (and demonstrable) in a less-entropy->more-entropy direction that do not seem possible in the reverse direction. The most physical of these involve the weak nuclear force (KTeV – BaBar – Belle explorations of CP violation).
This is where we could quickly go into ratholes looking for what’s eating gaps in the standard model, so I actually appreciate the terseness somewhat. 🙂
Celestial toymaker: The principle of microscopic reversability does state that at a certain level, one cannot distinguish the arrow of time, for example:
“Since evaporation and condensation are in general thermodynamically
reversible phenomena, the mechanism of evaporation must be the exact reverse
of that of condensation, even down to the smallest detail.”
The simple test for such phenomenon is the movie test: if you can’t tell if the movie is going in reverse or not, you might be looking at a manifestation of the principle of microscopic reversibility.
This was blogged about here, and I’ll quote them quoting C.V., to clarify the issue raised above:
“The observed macroscopic irreversibility is not a consequence of the fundamental laws of physics, it’s a consequence of the particular configuration in which the universe finds itself. In particular, the unusual low-entropy conditions in the very early universe, near the Big Bang. Understanding the arrow of time is a matter of understanding the origin of the universe.”
As far as Lewis Carroll goes, perhaps he was influenced by the thinking of the day, which was spelled out by Laplace:
“We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.”
So, in that mentality, people would be able to “remember backwards” if they had access to the “clockmaker’s blueprint”. We know now that such deterministic visions are a myth, and that even if one had such complete knowledge, one’s ability to predict the future would be very limited, due to chaos and Q.M.
However, one might be able to “remember backwards” for very short periods of time in one’s local environment. If you drop a glass and see it heading for the floor, you can anticipate it smashing to bits. Human response times, from sensory stimulation to registering and responding in the higher cortex, is about half a second – so that’s probably about the limit within which we will ever be able to remember (process mentally) backwards (or is it forwards? so confusing…).
If we were to remember backwards for longer than that, we would probably have all been eaten by saber-tooth tigers long ago.
LLorac (#6) wrote:
>
> So Carroll was a predator. I knew it!
Tongue in cheek in the circs perhaps, but most people take it for granted that Lewis Carroll may have been a bit of a kiddie fiddler on the quiet, in thought if not in deed.
However, a recent Dodgson biography (a review of which I read but not the actual work) apparently makes a good case that he befriended young girls mostly as a pretext to get to “know” their mothers more intimately .. !
But after his death his niece, in characteristic Victorian fashion, tore from his voluminous diaries every page which might have shed light on his true predilections. So I guess we’ll never know for sure.
“If two systems with incompatible arrows were to noticeably interact, the one with more degrees of freedom would swamp the other one and quickly “correct” its arrow of time. No being that “remembered the future” would survive very long in the real world.” :
Interesting…is there an quick way to see this ? Can this statement be made more precise starting from the H-theorem or something ?
I think that these statements wouldn’t appear in published papers, only because they are too straightforward, once you define your terms. The bit about memory is a piece of conventional wisdom, although you do have to be careful to define what you mean by “form a memory” in purely mechanical terms. I don’t remember seeing it discussed in a physics paper, but I’ll take a look.
The fact that two systems with oppositely-pointed arrows of time would interfere with each other follows from basic stat mech. If you have a system whose “initial” conditions are chosen so that it has a large (coarse-grained) entropy, but if you evolve it forward the entropy decreases, that means you have delicately tuned all of the momenta so that the system “aims” at a much tinier region of phase space, one with lower entropy. If you perturb it by just a little bit, you will generically deflect it away from that path, and the entropy won’t go down by as much; the bigger the perturbation, the less it will go down.
None of this has anything to do either with the anthropic principle, nor with CP violation!