SoylentNews is people
SoylentNews
from the will-this-help-me-win-the-lottery? dept.
A team in Australia turned thought experiment into lab reality by using lasers. Their subject matter was not a photon but a helium atom. The lasers they used served as a pair of grates, one before the other, with the second grate randomly dropped in.
What they found is weirder than anything seen to date: Every time the two grates were in place, the helium atom passed through, on many paths in many forms, just like a wave. But whenever the second grate was not present, the atom invariably passed through the first grate like a particle. The fascinating part was, the second grate's very existence in the path was random. And what's more, it hadn't happened yet.
In other words, it was as if the helium particle "knew" whether there would be a second grate at the time it passed through the first.
Also covered at: phys.org. An abstract is available; full report is pay-walled. The original news article is at Australian National University
Original Submission
(Score: 2) by Immerman on Thursday June 11 2015, @01:20PM
That is one possible interpretation of quantum mechanics. But since it's pretty much impossible to meaningfully measure anything without a conscious mind reading the measurements, it's equally impossible to determine whether the superposition of states collapsed at the moment of measurement/interaction, or at the moment a conscious mind read those measurements.
(Score: 1) by dusty monkey on Thursday June 11 2015, @02:40PM
t's equally impossible to determine whether the superposition of states collapsed at the moment of measurement/interaction, or at the moment a conscious mind read those measurements.
We have a principal for this. The simplest explanations...
- when you vote for the lesser of two evils, you are still voting for evil - stop supporting evil -
(Score: 2) by sjames on Friday June 12 2015, @01:36AM
It's about the same though. Alas, we have no apparent way to decide which is the case.
(Score: 2) by Immerman on Friday June 12 2015, @03:21PM
... are almost certainly wrong, but potentially incredibly useful if they're close enough approximations for the application at hand?
Newtonian gravity
electrons orbit the nucleus
light is a wave
atoms are particles (indivisible or otherwise)
...
I could keep this up all day.
(Score: 4, Interesting) by Zinho on Thursday June 11 2015, @02:50PM
. . . since it's pretty much impossible to meaningfully measure anything without a conscious mind reading the measurements, it's equally impossible to determine whether the superposition of states collapsed at the moment of measurement/interaction, or at the moment a conscious mind read those measurements.
Let's see if I can FTFY:
. . . since it's pretty much impossible to meaningfully measure anything without a conscious mind reading the measurements, it's equally impossible to determine whether a tree falling in the forest made the sound when it fell, or at the moment you listened to the audio recording of the event.
I'm probably going to sound like a QM noobie saying this, but the notion that consciousness is required for an interaction to take place seems ridiculous to me. By that logic, a star falling into a black hole millions of light-years away won't actually collapse its various quantum superpositions until we see it as we look through our telescopes. I think that was that actual point of Schrodinger's cat-in-a-box thought experiment; whether you've looked in the box or not, at the macro level the particle has either decayed and tripped the poison capsule (killing the cat) or it hasn't (and the cat is still alive). It is not necessary for the experimenter to know that the cat is dead or alive as long as the decay detector is working properly. The unconscious measurement instrument is sufficient to count as "observation", the human mind has no special place in the quantum universe.
Of course, I'm just saying that because I'm a Niels Bohr fan :P
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 2, Insightful) by Delwin on Thursday June 11 2015, @03:32PM
The only way I've been able to make sense of this is if we really are in a simulation. Then it makes perfect sense from a CompSci point of view - why calculate something until you absolutely need to?
(Score: 0) by Anonymous Coward on Thursday June 11 2015, @04:25PM
Problem is if some scientists are right and consciousness is a fundamental and "everything is conscious" (because they have problems with consciousness[1]).
[1] Consciousness is the 2nd most remarkable thing about this universe. The first being that the universe existing in the first place. It's a bit funny that scientists still have difficulty explaining the very first observation they make (assuming that they all experience consciousness - some might not given their responses/arguments on this topic).
(Score: 2) by mhajicek on Thursday June 11 2015, @10:50PM
But you're the only truly conscious entity. The rest of us are like NPCs; we're only a simulation of a conscious entity.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 0) by Anonymous Coward on Thursday June 11 2015, @06:24PM
As entertaining a thought that is, saying the universe is simulated instead of admitting that consciousness does not hold a sacred place in the cosmos is stretching very far.
(Score: 1) by HOLOGRAPHICpizza on Thursday June 11 2015, @08:37PM
I argue that it is more likely that we are in a simulation than not. Because we could theoretically one day build a computer big enough to hold the data and perform all the physics calculations for a universe. It would probably run much slower than real time, but you could just set up the initial conditions and let a big bang occur and watch solar systems form and life evolve and and all that, just by simulating particles and interactions.
So if one civilization was able to create this, so will the civilizations that evolve within the simulation. I think it's extremely likely that we are in a simulation within a simulation within a simulation countless levels deep. Why should we be so arrogant as to assume we are the "top level universe"?
(Score: 0) by Anonymous Coward on Friday June 12 2015, @03:12AM
That logic is quite loose isn't it? It is just as likely that our entire universe is a spontaneous superposition within a dust mote of another larger universe within another larger universe and so on. Given that there are easily many trillions of trillions of dust motes in each one, it is even more likely for a Horton Hears a Who scenario to play out than a nested simulation.
This would work with any other scenario that could both theoretically happen and if it did happen would theoretically happen many times.
Our universe could be just a dream.
There really could be a god of sorts within another god's work such that the universe is a shitty uni group project. [smbc-comics.com]
Existence could be an illusion and the idea of a universe having meaning all together does not make sense.
And things get even weirder if you let Cartesian doubt do what it does.
I argue that of the infinite probable possibilities that we have without the data or means to start crossing them off any one possibility, like being in a simulation, is infinitely unlikely compared to any one of the others being true.
(Score: 2) by Immerman on Friday June 12 2015, @03:13PM
The difference of course being that everything we know indicates that the tree will make a sound whether or not anyone is observing it. Whereas with QM everything we know says that the superposition of states doesn't collapse until... some as-yet poorly defined point in time potentially much later. And it may never collapse at all (such as in the many worlds and other interpretations), with the apparent collapse only being an observer-imposed illusion resulting from the superposition encompassing the observers themselves. In which case it is very much the observer's mind causing the *apparent* collapse, by virtue of being able to perceive only a single state.
Also, who said anything about humans being special? A mouse is conscious. An insect probably is (the more sophisticated ones almost certainly are), there's even a measure of evidence suggesting that plants may be.
(Score: 2) by Zinho on Friday June 12 2015, @05:21PM
I appreciate your point regarding the macro/micro scale difference; I could have picked a better analogy.
My point in making it was that the atom's interaction with the detector is sufficient in itself to cause the waveform collapse; whether there is a human/mouse/insect experimenter recording the output is irrelevant. "Conscious observer" in this context is irrelevant; either the diffraction pattern is created by the second grating, or it's not. Such interactions happen countless times in nature without our observation, and have no need of our awareness of them to occur. Was the projection screen that Young used for his original experiment conscious? Did the diffraction pattern exist when Young wasn't looking at it? The answers to these questions should be "it doesn't matter" and "yes". Saying that we need a "human" or "conscious" observer for the waveform to collapse is as ridiculous as saying that the tree falling in the forest didn't made a noise until we listen to the recording afterward.
The real argument to have regarding this experiment is whether the second grating or the projection screen is the point at which "observation" occurred. I've been looking for more clarification on that's going on here, and found that in previous experiments with photons the second grating was added after the photon had passed it and still created the diffraction effect. [physicsworld.com] (check out the "Photon First" paragraph). That would have been a much more dramatic effect to replicate with an atom, and may actually require info going back in time.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 2) by Immerman on Friday June 12 2015, @06:40PM
>the atom's interaction with the detector is sufficient in itself to cause the waveform collapse
That is a perfectly reasonable assumption, but I can't think of any way to create a falsifiable hypothesis to test it. Can you? If the entire apparatus remained in a superposition until consciously observed, the outcome would be indistinguishable from an immediate collapse, would it not?
Also "macroscopic" is an arbitrary a line to draw for quantum effects as "conscious". Massive neutron stars, are postulated to be heavily influenced by quantum effects, and the behavior of even more degenerate theoretical quark stars should be heavily dominated by quantum effects on scales that would make a laughingstock of our concept of macroscopic.
I do agree that the timing of the second grating would be a more interesting question, but as mentioned in your link there is more than one interpretation
this would force us either to conclude that our decision to measure the particle's path affects its past decision about which path to take, or to abandon the classical concept that a particle's position is defined independent of our measurement
(Score: 2) by Zinho on Friday June 12 2015, @10:17PM
the atom's interaction with the detector is sufficient in itself to cause the waveform collapse
That is a perfectly reasonable assumption, but I can't think of any way to create a falsifiable hypothesis to test it. Can you? If the entire apparatus remained in a superposition until consciously observed, the outcome would be indistinguishable from an immediate collapse, would it not?
Fair point. Your question flirts with solipsism, which I also reject as highly improbable and unnecessarily complicated as a hypothesis. In this case I don't see either hypothesis as useful, since the experimenter isn't putting his own eyeball in the line of fire of the lasers or helium particles; instead, there's a screen being illuminated or a counter being incremented, and the researcher reads those. I'm fine with discussions about at what point in the apparatus up to and including the detector the waveform has collapsed, but I learned when I was 2 years old that things still exist when I don't look at them. [wikipedia.org] My failure to observe the output display of a Geiger counter should not change its count, provided that I'm not somehow interacting with its inputs.
Also "macroscopic" is an arbitrary a line to draw for quantum effects as "conscious". Massive neutron stars, are postulated to be heavily influenced by quantum effects, and the behavior of even more degenerate theoretical quark stars should be heavily dominated by quantum effects on scales that would make a laughingstock of our concept of macroscopic.
I think we're getting into the realm of "things I never said", but I'll go with you on this. I don't know whether quarks, atoms, rocks, trees, planets, or neutron stars are "conscious" or not. They've never spoken to me, so there's that, but what does it even mean to be conscious? Could we, in theory, test whether an object can cause a quantum waveform to collapse through "observation" as a guideline? If so, then there are some laser beams in quantum computing labs that count as conscious. Since philosophers can't even come up with a definition for consciousness that includes all humans (see solipsism again) I find it to be a useless metric in quantum physics.
this would force us either to conclude that our decision to measure the particle's path affects its past decision about which path to take, or to abandon the classical concept that a particle's position is defined independent of our measurement
This is where I've gone in my analysis of quantum physics. I give up on imagining atoms and their subatomic components as billiard balls or bullets, and accept that from emitter to detector they are unlike anything I see on a daily basis. I accept that, when they start moving, knowing their momentum prevents me from saying anything meaningful about their position; and that they may not even have a "position" the way I think about for things sitting on my desk. I'm more OK with this than the idea that they are somehow gaining clairvoyance and the mystic ability to determine whether something looking at them is "alive".
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 2) by Immerman on Saturday June 13 2015, @07:26PM
I fail to see how the idea that waveform collapse occurs on observation is "flirting with" the idea that the self is the only thing that can be known to exist. I know perfectly well that their is a quantum waveform at with a given probability distribution in my box, I'm simply arguing that it might not collapse into a single concrete state until someone looks at the counter, rather than immediately upon interacting with the larger but still fundamentally quantum system of the detector .
Ah and, I seem to have dropped a word and changed the meaning of a paragraph. That should be
"Also "macroscopic" is as an arbitrary a line to draw for quantum effects as "conscious".
I didn't mean to suggest that stars are conscious*, but rather that any sort of "measurement" that relies on interacting with a macroscopic (and hence presumably non-quantum) system is challenged by the concept that entire classes of stars should exist in a state that can only be adequately described by their quantum wavefunctions. If an entire star can only exist as a non-classical quantum system, what makes you thing a Geiger counter is fundamentally different?
* The consciousness of stars would be a completely different discussion. I do happen to currently subscribe to the school of thought that consciousness is a fundamental quality of the universe rather than an emergent phenomena, but that's generally irrelevant to most discussions, probably even this one unless we can postulate a manner in which a star with a coherent consciousness could meaningfully observe our instrumentation.
(Score: 2) by Zinho on Monday June 15 2015, @02:42AM
The solipsism connection comes from the fact that "consciousness" is so poorly defined and understood that there are philosophers even today who claim to be unsure that anyone besides themselves even exists, let alone is capable of independent thought. If that's the case, how are we to determine what is and is not conscious? If we can't cleanly define consciousness, what kind of basis is that for a useful scientific theory?
"Macroscopic" can at least benefit from tautology - define it as the point at which quantum effects cease to dominate, and leave it at that. :P
Also useless as a guideline, especially given your very valid point regarding neutron stars.
For me, the essence of "observation" is interacting in a way that can determine the quantum state. In our labs that usually involves a destructive read - absorption and re-emission in the case of Young's screen, leaching some kinetic energy to create a cascade of freed electrons as in Geiger's counter, etc. Our detectors in the lab generally transduce the quantum state we want to read into a classical interaction that we can see, feel, hear, record electronically, etc. I would argue that the act of performing such a transduction is sufficient to count as "observation" in a meaningful sense and collapse the waveform, even if we figured out how to make it non-destructive.
The alternative you suggest is fraught with problems, not the least of which is deciding what counts as "observation" of the transducer. If I had a blind researcher listening for a Geiger counter's clicks, does the device fail to click if he leaves the lab to use the restroom? We are now exactly back to the question of "if a tree falls in the forest and no one is there to hear it, does it make a sound?" Pointing out that we don't have a meaningful way to test whether that is the case or not (because how can we know happens if the result looks the same either way?) is exactly the problem I have with solipsism - it posits an unnecessarily complicated world for no better reason than questioning "how can I know any different?"
I'll leave you a thought experiment which I hope would illustrate how we'd tell, extending the case of my blind researcher. Let's imagine that he's blind and deaf, and that the Geiger counter's output is a set of mechanical wheels (like a car's odometer) instead of a click, which the researcher reads by touch. If the system of quantum event -> detector -> counter were in a state of quantum superposition where for each possible nuclear decay even the wheels both turn and don't turn until the researcher reads the output then we enter a state of paradox. The wheels are not quantum devices; their state is overwhelmingly determined by the Brownian motion of the air around them and other classical interactions they experience, so how can their position be entangled with the uncertain quantum events being measured? They certainly aren't remaining stationary until just before being touched and then spinning rapidly to catch up; at some point that would require some portion of them to exceed the speed of light (depending on how long the researcher lets it run). The many-worlds hypothesis makes quick work of this paradox, creating parallel universes for each event detected; the researcher doesn't know which universe he's in until he reads the counter, but for each universe the counter wheels advance via classical mechanics based on whether or not an event was detected in that universe and are already in their appropriate state when the researcher touches the dial.
I'd love to keep this discussion going, I'm finding it invigorating. Unfortunately, I'm about to leave on a week-long trip in the mountains and won't be able to make any replies until next Saturday. Please follow up with another post, but be patient for my next reply ;^)
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 2) by Immerman on Tuesday June 16 2015, @03:56PM
Well, if you want to bring philosophers into a scientific discussion you'll be there all night and probably never reach any conclusions - regardless of the topic. Modern philosophy has largely degenerated into mental gymnastics - it's great for developing strength and flexibility, but isn't actually directly useful for much. It just hasn't been the same since science and religion split off and took most of the practical questions with them.
Just because philosophers can't agree on whether anything beyond themselves doesn't mean there's no meaningful definition to be found - in fact it's a largely orthogonal question. Even if we had a perfect definition, we'd still run afoul of Descarte's evil-demon hypothesis and be unable to claim with certainty that anyone else even exists, much less is conscious.
You seem to see my point though -we could as easily define consciousnes by tautology: "a system which causes quantum wavefunctions to collapse when interacted with". In fact if we could find some way to detect exactly when the wavefunction collapsed, that might form the basis of a consciousness detector.
As for your cog-driving Geiger counter, of *course* the wheels are quantum devices - *everything* is a quantum device - what we call "classical physics" is the unexplained anomaly. How does combining a bunch of tiny quantum systems into ever-larger quantum systems eventually create something that appears to be governed by much simpler rules to a degree far beyond what can be explained by statistical averaging?
As for your speed question? If my preposition is correct then there would be no issue - the wheels would themselves would be in a superposition of states, having both rotated and not rotated as they interacted with the superposed measurement signal. The question is only whether the superposition collapses when it interacts with some poorly defined "macroscopic system", or if it continues to expand until it interacts with something conscious, or some other criteria is met, or even if it never actually collapses at all. There have been researchers who have managed to create mm-scale superpositions, so clearly it's not just "too many atoms involved", but as yet we really don't know what that criteria may be - it's *all* speculation. But clearly it doesn't simply end with the interaction of the initial superposed particle - far too many experiments have managed to transfer that superposition to other, often much larger, systems.
Enjoy the mountains, it's been too long since I spent a good chunk of time in them. I'll be around.
(Score: 2) by Zinho on Monday June 29 2015, @08:28PM
Thanks for the well thought-out answer! And your patience as well; I've been back for over a week now, but too busy catching up to spend time giving your response the consideration it deserves.
From what I read in your last post, I believe you and I are very close to each other philosophically, and perhaps talking past/around each other. I like your idea of a consciousness detector based on quantum waveform collapse; I even am open to the idea that we'll make startling discoveries, with many things we consider "inanimate" being detected as conscious. That would make for interesting news headlines, and perhaps a few amusing activist groups. [schlockmercenary.com]
That being said, I think I'm expressing myself poorly regarding my attitude towards consciousness. There are plenty of people willing to talk about consciousness who have more scientific street cred than philosophers; neuroscientists are a prime example. Even for them, though, it is a "hard problem". [livescience.com] Quantum mechanics is a difficult enough field to research, study, or understand; we do ourselves no favors be importing intractable problems from other fields. As a result, I find consciousness to not be useful as a tool in quantum mechanics.
Even if it were true, though, that conscious observation were the determining factor in waveform collapse, the mechanism by which that occurs would fall deeply into the field of untestable metaphysics. To restate one of my earlier ideas, how does the decaying atom know whether or not Schrodinger's cat is conscious? If the cat is asleep would it not be poisoned? If the cat doesn't count as conscious, how does the system know when/how/if/by whom it has been observed? If this is what's real, testing could/should be performed to determine its limits and explore it as a possible means of long-distance communication. If such testing is not possible, though, then it again isn't very useful as an analytical tool or avenue of research.
I mentioned Occam's razor in a different discussion thread, and I want to use (perhaps over-use?) it here. Instead of "observation" I prefer "measurement" as the collapsing action. Quantum entanglement is a delicate state, short-lived and easy to destroy. Certain types of interactions with an entangled system result in a determination of its state (e.g. measurement of polarization), which forces the waveform to subsequently act in a coherent manner for the entire entangled system (assuming that many particles are entangled). It is easy for me to believe that components of entangled systems behave consistently when measured because their entanglement requires it - if the measurements were going to be inconsistent, the particles wouldn't have been entangled in the first place. This is where the razor comes in - if I believe that the system is internally consistent from the beginning of the experiment, there is no need for me to be spooked out by measurements of widely separated entangled particles being consistent with one another.
Back to the article topic, my over-use of the razor in this case leads me to believe that the atoms of the experiment didn't need prescience or metaphysical awareness of the experimenter. If there are two grates and a detector, then the atoms will interact with grate A the same way every time that interaction takes place. If grate B is lowered, then the atoms interact with it; if it isn't, then they don't. At the detector, the atoms interact with the detector in a manner consistent with their history of previous interactions. This only causes problems if I want to believe things like that the atom has a specific position or path that it's following between grate A and the detector. That specific incorrect belief is what is disproved by this experiment. I am perfectly wiling to believe that grate B's interaction with the atom shifts it later behavior to be more wavelike than particle-like, and that there may not have been a specific path from grate A to detector in the first place.
Please understand that I'm not ruling out large-scale entangled systems. I'm actually quite looking forward to commercialized quantum computing systems, which rely on just such mass entanglements. I'm also looking forward to quantum cryptography, which may be needed to protect our privacy in a world with ubiquitous quantum computing; since good Q. crypto requires long-distance transmission of entangled pairs, I rather hope that entanglement over long distances (as has been repeatedly demonstrated) is not only possible, but practical and that we understand it well. I'm simply skeptical of interpretations of lab results which imply overly-complicated and untestable concepts of how the world works when much simpler explanations are readily available.
(Score: 2) by Immerman on Tuesday June 30 2015, @03:00PM
If we are talking about "useful tools", then yes, I agree - for the time being at least discussions of interactions between consciousness and QM are unlikely to be terribly productive. That does not mean it's inherently untestable however, only that nobody has yet thought of the tests needed. If, however, someone *does* think of such a test (and a testable link is discovered) it's likely to have far-reaching implications for both QM and consciousness research. But that requires that someone with a suitably subtle intellect not dismiss the possibility out of hand. There may even be non-dimissive conversations with peers required.
I have no answers as to the mechanism and limits of such an interaction, at the moment I can't even think of any well-formed speculations. But then formulating and testing such hypotheses is the whole point of scientific research, is it not? Though I will admit I have my doubts that the addition of consciousness would have any impact on the potential for long-distance communications.
> Instead of "observation" I prefer "measurement" as the collapsing action.
And as a practical short-term matter, that is likely the most productive approach. I think it's important though to remember that that is a completely untested preference, a matter of faith, and should be treated as such in a scientific discussion, lest your confidence spread and discourage the explorations that might yield definitive results.
Occams Razor is a wonderful tool for formulating useful explanations, but I think it's important to consider that in a scientific context it has pretty much invariably led to false, or at least incomplete, theories. Arguably often among the best theories that could be reasonably expected to emerge from the constraints of the culture and technology of the time, but nevertheless theories that have since been proven fundamentally flawed.
(Score: 2) by Zinho on Tuesday June 30 2015, @05:34PM
I completely agree with everything you just said, I think we're talking the same language now.
There is plenty of room for speculation on what is and is not going on in QM, and plenty of areas where we're really not sure what's happening because our efforts to measure anything change the systems we're measuring. Research into those areas of our ignorance will require subtle minds open to new ideas and careful consideration of new possibilities.
As long as we know that's where our discussion is sitting, I have no problem with that. Given that I am an amateur in this field (I took the course in college, but that's not what I'm paid to do today) I tend not to have a lot of discussions at that depth. In most discussions of QM I try to restrict myself to things that I firmly understand (or at least, think that I do) and theory that is at least consistent with my textbooks if not widely accepted in the field.
As a result, I do tend to get a bit snippy in tone on occasion. As an example, when someone finds a way to test for quantum entanglement being passed to measurement instruments and/or requiring a conscious observer for the expanded entangled system to collapse there will literally be a pair of PHDs waiting for them at the end of the project, plus a mention in two different fields' textbooks. I'll be honest, I get a bit nervous about how people with a shaky grasp of the topic will interpret speculation along those lines when discussing things like that in public forums. Thanks, by the way, for pointing out how I was coming across; it gave me an opportunity to think through why I was reacting the way I did and consider better ways to express myself. Hopefully this paragraph is a more tone-neutral way of expressing the same sentiments.
Speaking of faith, I've actually found this conversation a bit surreal; I often find myself at the other end of it. I'm a man of faith, and believe that the universe we inhabit is a large-scale engineering project created to make a home for conscious beings like ourselves. I suspect, based on other components of my faith's philosophy, that it is possible that animals, the earth, and even sub-atomic particles may possibly have intelligence of a sort at a level we don't fully understand (as if we even understand our own intelligence or consciousness). Discussions of such things in scientific circles generally elicits immediate derision and out-of-hand dismissal on the basis that my beliefs are based wholly upon superstition and must therefore be false. In our conversation I feel like I've been playing devil's advocate, struggling to balance between respectfully (and, regretfully at times, silently) agreeing with your sentiments and trying to point out where they over-reach the current state of the art as I understand it.
Thanks again for taking the time and patience to have a well thought-out discussion. I'm not sure that I have much more to contribute to this one, so respond or not at your leisure. I'll be watching for your future posts, and look forward to more engaging conversations when the opportunities arise.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 0) by Anonymous Coward on Tuesday June 23 2015, @01:03AM
I make it a point to sit down right next to certain people. No wonder the place is deserted, I could already sense the razor-sharp defensive spines, this heap of human preferred his personal space on the scale of rooms and had covertly scrutinized my actions from the moment I stepped in. Why was he even here? A dozen meters away from a never-ending stream of people?
“Hello”
No reaction, yet had it been possible the gap between us would have expanded at lightspeed. My neighbor would slam through the wall at the end of the bar counter, the wall he sat next to, and off into a dimension of his own.
He looks in my general direction, nods hello, tries to classify me once again, ready to attack.
Such attacks seldom happen to me, instead and after the customary period of silence what happens is this.
“They're all wrong you know”
“About what?”
“Time travel”
“Yeah?”
“Grandfathers and paradoxes and killing Hister. It's all nonsense”
“…”
“You don't go backwards like that, you go backwards like forwards”
“What do you mean?”
“When you go backwards nothing at all happens to the you that travels from the future, nothing at all, nada, you don't travel at all or you can't tell you did. Everything happens to the you back then”
I don't say it. If I say it I might as well not have bothered and left him alone without this peculiar kind of torture. Levity kills. He's not looking for sympathy or approval or any social trapping, and least of all scorn and ridicule.
“Remember r, always remember r”
He pauses and drinks a little in our bubble of calm. His defensive systems are back to passive mode. Is that all? Remember r? What is r? I try to make myself disappear in the hope of more.
“You remember the future, that's what happens. You remember the future. You know something that is going to happen. Perhaps something you did but not yet. But you don't know why. You don't know how. You don't know when. You don't know where the memory of the future starts or stops or what is fantasy or how much your inner gecko is trying to help you out or if you've become insane or whether how much or if the future really is that bad or why it isn't impossible to die that many times in what seems such a short time and why the infantry charge is going up the side of the abyss in the deep-water trench or why you see them and their blazing guns and the supercavitational steam from front on. But it has the feeling of memory. Every time, for every slice of future”
He looks me directly in the eyes for what seems like eternity compressed, then he looks at the people streaming past beyond me in the transit lounge. The debriefing is complete.