Reverse chronology — narrating a story, or parts of one, backwards in time — is a venerable technique in literature, going back at least as far as Virgil’s Aeneid. Much more interesting is a story with incompatible arrows of time: some characters live “backwards” while others experience life normally.
Probably the most famous contemporary example is Martin Amis’s chilling novel, Time’s Arrow.
Eating is unattractive too… Various items get gulped into my mouth, and after skillful massage with tongue and teeth I transfer them to the plate for additional sculpture with knife and fork and spoon. That bit’s quite therapeutic at least, unless you’re having soup or something, which can be a real sentence. Next you face the laborious business of cooling, of reassembly, of storage, before the return of these foodstuffs to the Superette, where, admittedly, I am promptly and generously reimbursed for my pains. Then you tool down the aisles, with trolley or basket, returning each can and packet to its rightful place.
The narrator of Time’s Arrow is a disembodied consciousness who lives inside another person, Odilo Unverdorben. The host lives life in the ordinary sense, forward in time, but the homunculus narrator experiences everything backwards – his first memory is Unverdorben’s death (although, for expository purposes, he comes into existence as a full, speaking intellect). He has no control over Unverdorben’s actions, nor access to his memories, but passively travels through life in reverse order. At first Unverdorben (going under the name of “Tod Friendly”) appears to us as a doctor, which seems like a morbid occupation – patients shuffle into the emergency room, where the doctors suck medicines out of their bodies and rip off their bandages, sending them out into the night bleeding and screaming. But near the end of the book, we learn that Unverdorben was an assistant at Auschwitz, where he created life where none had been before – turning chemicals and electricity and corpses into living persons. Only now, thinks the narrator, does the world finally make sense.
Relative to the people that experience the reversed time they would certainly find a different set of theories that attempt to explain the world around them right?
Not necessarily. They might rejoice in and worship the mystery, and persecute anyone who tried to make sense of it. Some things are polarity-neutral.
One more example, not so masterful: Bearing An Hourglass by Piers Anthony. Contains at least one extended scene where the hero’s arrow is opposed to everyone else’s &emdash; although he fudges a bit, making people who interact with the narrator have their arrow’s “partially” reversed. (He has a conversation with a woman, whose sentences are backwards but progress forward in paragraphs; she eats backwards but speaks forward (sound travels from her mouth to the hero’s ear), etc.
…Just to elaborate a little on my last post: I once had a memorable experience that I’m sure many others have also had. I was anesthetized for several hours while my wisdom teeth were removed. The amazing thing was that those hours went by instantaneously for me. I was asked to count backwards from 100, and when I got to 97 the doctor said, “We’re done!” It was disorienting and hard to believe. A completely dreamless sleep. A sharp temporal discontinuity
– like a robot being turned off and on again.
When I recall that experience, I wonder if death might be like that – the ultimate temporal discontinuity. When you are dead, any finite amount of time will pass instantaneously. Twenty billion years or eight hundred googleplex years, it doesn’t matter. As far as we know, consciousness ends permanently at death, effectively erasing time and pulling the plug on the universe. As long as it’s finite, the universe will be over and gone as if it had never existed. A brief dream, and a dream without a dreamer has no chance of being remembered. On the other hand, if time extends infinitely into the future…
(Sorry! That last post should have been in incompatible arrows II)
There’s also the character Janus Poluektovich in the Strugatsky brothers’ Monday begins on Saturday, who goes through time in a piecewise continuous fashion, living each day normally, and then jumping to the previous day at midnight. It’s a delightful book overall.
I’m surprised nobody has mentioned the movie “Memento” yet, probably the most well-known recent example. It’s developed a large fan base.
There also was a Seinfeld episode that took place in recent order. The plot involved a trip that the characters took to India for a wedding.
Surely we can take a relativistic position and say that for any given event there is a future which can be signalled and a past from which signals may be received? The “arrowhead” of the arrow of time associated with such an event just points towards the future for our mental convenience.
Observation is concerned with the past; anything that can receive a signal is a potential observer, and anything that receives such a signal is an actual observer. This applies to classical events as well as quantum ones.
Signalling is concerned with the future; anything that may generate a signal is a potential actor, anything that generates a signal is an actual actor. Again, this applies to classical events as well as quantum ones.
For our own convenience we connect actual actors to appropriate actual observers with unidirectional arrows, and call those connections causal relationships. We consider potential interactions similarly – connecting actual or potential actors to potential observers with unidirectional arrows.
Again for convenience (“tractability”) we reduce large sets of these unidirectional arrows, using aggregation, probabilistic approximations, and other arrow-hiding techniques. We do this day in and day out in our classical lives, as well as when studying QM. We do this consciously and unconsciously, and we really lack the facilities to *not* do this on a large scale.
We have little difficulty aggregating mildly disjoint sets of causal relationships, such as those involving different, spatially-separated actual observers. We do this regularly in our own heads – as an example, most of us excel at aggregating lots of little photon-hits-photopsin-just-right events in our retina into a single flash of light. We aggregate ourselves into a single actual observer of a single actual actor, observing a flash of lightning, and usually do not (and probably cannot *completely*) consider each discrete actor-observer relationship that we see first-second-third-or-nth hand, as excited particle releases hot photon, which in turn excites another particle or is scattered, and so on, all the way to the air proximal to our corneas, through our lenses and intraocular media, and into the retinal cell where a protein is deformed. We also don’t consider the actual result of the deformation (we generally assume a signal transduction is the result), and generally have a poor idea of nanoscopic behaviours from there all the way to the visual cortex, and practically no small-scale idea about what happens from that point at all.
We “see” one event and think of it as one event, although that is a conspiracy involving probabilities of observation by flash-detecting molecules, and how reliable their communication of such observations “into the future” are, which in turn depends on the probabililties of detecting those signals, and generating their own.
We readily impose our own approximation of causal relationships on observers nearby. We assume that other people nearby see a similar flash, and can make assumptions about the behaviours of non-people observers that reflect, scatter, or absorb signals related to the flash, and assume that everything nearby has a substantially similar relationship to that particular past set of events.
What happens if we try to break this pattern of thinking?
We’ve studied QM philosophical problems involving deliberately delaying the connection between actual event and potential observer in the form of cats and puppies, not to mention experiments involving extremely high refractive indices, and day to day experience with long optical fibre runs or communications that detour through a geosynchronous sattelite, meteor burst, or suitably reflective astronomical object (the moon has been done). Astronomers see even longer delays in one-way paths from events, and cosmologists are pretty keen on observations which provide geodesics of dramatically different lengths from closely related events to terrestrial observers.
These causal relationships are all still unidirectional — same arrowhead, but somewhat different shafts.
This lets us consider very warped causal relationships, where a signal we generate now is received very quickly by a spatially separated observer along path “A”, whose observation is immediately signalled back along path “B”, which is much much slower. Other tricks for manipulating worldlines lead us into the realm of whether CTCs can exist.
Correlating actor/observer interactions is useful for a variety of reasons, and a “privileged aggregation” is an attractive coordinate system. Interactions within the CMBR are obviously attractive, and many cosmologists use the idea of other cosmologists who “see” the CMBR in various ways (such as with no dipole anisotropy) as a way of exploring questions involving a variety of correlated observations we make locally. If we figure that there is a universally-available privileged view of the evolution of the CMBR, and use that as a “universal” arrow of time, then we *can* ask questions about observations available to potential observers that would have views of the CMBR with *huge* dipole anisotropies.
The salient questions to me are:
* assuming there is some privileged “universally agreeable” time coordinate system
* assuming that the time coordinate system will *typically* be perceived as monotonic increasing, or mappable to such a perception, for observers we can reason about
(a) what would be the potential observations available to an entity (human, classical or quantum) with an “extreme” mapping, and (b) can a mapping be “extreme” enough to be considered a reversal?
Stepping back into a more relativized causality, what kind of interaction could an observer with a receive-from-past/transmits-to-future “direction” which is close to our conventional aggregates have with us?
If a potential interaction is possible, can we transmit a backwards-moving observer some information we have in turn received “conventionally” from our past? What would that observer learn?
Stepping back into a more relativized causality, what kind of interaction could an observer with a receive-from-past/transmits-to-future “direction” which is close to our conventional aggregates have with us?
errrr
… “which is NOT close to” or “which is close to the REVERSE of” our conventional aggregates…
Sometimes the metabolic half-life of caffeine is too short!
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Very interesting. Can’t resist to read later parts.
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