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Space Science

A Growing Number of Scientists Are Convinced the Future Influences the Past (vice.com) 200

Posted by BeauHD from the time-and-causation dept.
An anonymous reader quotes a report from Motherboard: Have you ever found yourself in a self-imposed jam and thought, "Well, if it isn't the consequences of my own actions"? It's a common refrain that exposes a deeper truth about the way we humans understand time and causality. Our actions in the past are correlated to our experience of the future, whether that's a good outcome, like acing a test because you prepared, or a bad one, like waking up with a killer hangover. But what if this forward causality could somehow be reversed in time, allowing actions in the future to influence outcomes in the past? This mind-bending idea, known as retrocausality, may seem like science fiction grist at first glance, but it is starting to gain real traction among physicists and philosophers, among other researchers, as a possible solution to some of the most intractable riddles underlying our reality.

In other words, people are becoming increasingly "retro-curious," said Kenneth Wharton, a professor of physics at San Jose State University who has published research about retrocausality, in a call with Motherboard. Even though it may feel verboten to consider a future that affects the past, Wharton and others think it could account for some of the strange phenomena observed in quantum physics, which exists on the tiny scale of atoms.

"We have instincts about all sorts of things, and some are stronger than others," said Wharton, who recently co-authored an article about retrocausality with Huw Price, a distinguished professor emeritus at the University of Bonn and an emeritus fellow of Trinity College, Cambridge. "I've found our instincts of time and causation are our deepest, strongest instincts that physicists and philosophers -- and humans -- are loath to give up," he added. Scientists, including Price, have speculated about the possibility that the future might influence the past for decades, but the renewed curiosity about retrocausality is driven by more recent findings about quantum mechanics. [...] While there are a range of views about the mechanics and consequences of retrocausal theories, a growing community of researchers think this concept has the potential to answer fundamental questions about the universe. "The problem facing physics right now is that our two pillars of successful theories don't talk to each other," Wharton explained. "One is based in space and time, and one has left space and time aside for this giant quantum wave function."

"The solution to this, as everyone seems to have agreed without discussing it, is that we've got to quantize gravity," he continued. "That's the goal. Hardly anyone has said, 'what if things really are in space and time, and we just have to make sense of quantum theory in space and time'? That will be a whole new way to unify everything that people are not looking into."

Price agreed that this retrocausality could provide a new means to finally "eliminate the tension" between quantum mechanics and classical physics (including special relativity). "Another possible big payoff is that retrocausality supports the so-called 'epistemic' view of the wave function in the usual quantum mechanics description -- the idea that it is just an encoding of our incomplete knowledge of the system," he continued. "That makes it much easier to understand the so-called collapse of the wave function, as a change in information, as folk such as Einstein and Schoedinger thought, in the early days. In this respect, I think it gets rid of some more of the (apparently) non-classical features of quantum mechanics, by saying that they don't amount to anything physically real."
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A Growing Number of Scientists Are Convinced the Future Influences the Past More

A Growing Number of Scientists Are Convinced the Future Influences the Past

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  • Ant-Man 3: Quantumania (Score:5, Funny)

    by xevioso ( 598654 ) on Thursday March 16, 2023 @10:38PM (#63377265)

    Is so much nonsense, and yet it makes a lot of sense. When you make up whole worlds and times outside of times, you can make anything work. Sounds like they saw this movie.

    Or maybe Kang visited the guy at Stanford, and gave him a hint?

    Let us all look to Marvel movies, going forward, for our understanding of the universe, and the truth will be revealed.

    • Re:Ant-Man 3: Quantumania (Score:4, Funny)

      by Powercntrl ( 458442 ) on Thursday March 16, 2023 @10:48PM (#63377279) Homepage

      The multiverse: an overused trope to justify breaking canon in endless reboots with younger, edgier actors. [youtube.com]

    • Re:Ant-Man 3: Quantumania (Score:5, Interesting)

      by phantomfive ( 622387 ) on Friday March 17, 2023 @12:21AM (#63377355) Journal
      The idea of time going backwards is at least as old as Richard Feynman, in his lectures on QED [wikipedia.org]. That doesn't mean he believed it, he was just noting that the math works that way. And I doubt Feynman was the first to notice that, although I don't know the whole history.

      Of course, the question is whether this is testable in any way at all. If he can design experiments to test it, then great. That is the only way it is scientific.

      • Quantum and QED (Score:5, Informative)

        by Roger W Moore ( 538166 ) on Friday March 17, 2023 @08:10AM (#63377827) Journal

        The idea of time going backwards is at least as old as Richard Feynman

        Not really, Feynman showed that anti-matter was mathematically equivalent to matter going backwards in time, not that anything actually went backwards in time. The idea of going backwards in time is much much older - both H.G. Wells and Twain wrote novels based on it in the 1890's and I doubt they were the first.

        However, the concept here is not about time travel but about the future influencing the past and that is a natural consequence of quantum mechanics because, just as the uncertainty relationship means that you cannot know exactly where a particle is in space, there is a similar relationship that means you cannot know exactly when it is either i.e. the universe is not only "blurry" in space it is "blurry" in time as well.

        It has already been shown that photons can interfere with each other when separated in time so it stands to reason that the fact that the universe does not define "now" exactly means that future events can have an influence but, like quantum spacial phenomena, we are talking a very small distance into the future i.e. tiny fractions of a second and really it is not "future" events but more a case that the universe does not localize particles in time any more than it does in space.

        • No mod points but wanted to say thanks for an informative post.

          Since I've nothing directly to add I'll just say that the first thing that popped into my head when I read the summary was - 'I wonder how long it will be before this will be used as the badly deformed justification by someone pushing woowoo on Faceogram?'.

        • Not really, Feynman showed that anti-matter was mathematically equivalent to matter going backwards in time, not that anything actually went backwards in time.

          I literally said that. You just are two impatient to read two sentences. If you had read more than a single sentence, you would have seen that I wrote that. Reading comprehension, dude.

          • As I said, not really. You were in the neighbourhood but not there. Feynman's idea was not "time going backwards" but that anti-particle solutions were the same as particle solutions with the arrow of time flipped. This has more to do with the time-reversal symmetry of QED, not time travel, and Feynman definitely believed it. Physics comprehension, "dude".

            • Feynman's idea was not "time going backwards" but that anti-particle solutions were the same as particle solutions with the arrow of time flipped.

              So what you are saying, is that Feynman noted that the math works that way? Learn to read.

      • Re: (Score:2)

        by HiThere ( 15173 )

        IIUC, one of the consistent interpretations of quantum theory invoked retrocausality. But it doesn't make any different predictions than the other consistent interpretations. So which one you pick is a matter of taste. Personally I prefer the Everett, Graham, Wheeler multi-world model, but it's hardly the only interpretation. And they're called "interpretation"s because they predict exactly the same observations.

        (The thing about particles going backwards in time, e.g. a positron being a time-reversed el

  • It was on an episode of SeaQuest DSV, where the SeaQuest went forward in time and found Adam and Eve playing video games, and the SeaQuest crew had to get them to meet so they'd repopulate the Earth.

    That makes about as much sense as this.

  • Jeremy Bearimy (Score:3)

    by ironicsky ( 569792 ) on Thursday March 16, 2023 @11:02PM (#63377295) Homepage Journal

    It's makes sense, time isn't linear, it's Jeremy Bearimy written in English cursive, including the dot over the I.

    What is the dot over the I? Its an isolated point on the timeline which contains Tuesdays, July, and "occasionally...the time moment where nothing never occurs.

    Otherwise time follows the Path! ... I couldn't help myself.
    Ikyky

  • Experiments have shown there maybe something to it (Score:5, Informative)

    by bubblyceiling ( 7940768 ) on Thursday March 16, 2023 @11:03PM (#63377297)
    IIRC A variation of the famous double slit experiment did show this to be true. Light would appear to change which path it took, to produce the expected result, even if the experiment setup was changed, post when the light path should have been âoechosenâ by the light

    • Re:Experiments have shown there maybe something to (Score:5, Interesting)

      by test321 ( 8891681 ) on Friday March 17, 2023 @04:40AM (#63377523)

      It's Wheeler's delayed-choice experiment https://en.wikipedia.org/wiki/... [wikipedia.org] but its interpretation has not been retro-causal (until this news report today that "a growing number of scientists" would apparently discard causality as a universal).

      • Re: (Score:2, Interesting)

        by Zorpheus ( 857617 )
        I'm just reading on this on Wikipedia:
        "Observing that photons show up in equal numbers at the two detectors, experimenters generally say that each photon has behaved as a particle from the time of its emission to the time of its detection, has traveled by either one path or the other, and further affirm that its wave nature has not been exhibited"
        I think this is rubbish. The photon is a wave until it interacts with something. The wave function describes that the photon goes both ways after the beam split
        • Here is something I have never understood.

          The index of refraction is such that a photon going from one medium to another takes the fastest (not shortest) path to its destination in the second medium, given the different speeds it travels through each.

          How? Is it somehow effectively everwhere but with a different delay until it is observed at wherever it arrives first?

          • Re: (Score:2)

            by ceoyoyo ( 59147 )

            The photon's destination is chosen by the angle of incidence and the refractive indices of the materials. You don't tell the photon "okay, go here" and it figures out how to get there, files a flight plan, then heads out.

            That is, it doesn't necessarily do that. There are legitimate theories where any disturbance in a quantum field travels forward from emission to absorption and backwards from absorption to emission, and where they reinforce is the path we see the particle taking.

            • the photon's destination is chosen by the angle of incidence and the refractive indices of the materials.

              Sure, but then how does that just happen to be the angle that would make it arrive soonest at any point in second material? It seems the index of refraction is determined by some sort of race of forces occurring at the boundary between the materials.... which starts to sound like your second paragraph.

              • Re: (Score:2)

                by ceoyoyo ( 59147 )

                The index of refraction is determined by the speed of light in each of the two media. If you change the relative speeds, the photon ends up in a different place. You can in fact formulate the problem in such a way that light simply takes the straight line path through a warped space. That's what General Relativity does, except with gravity instead of electromagnetism. There are very deep arguments about why straight lines and mimimum/maximum action are the rule. The fact that it does all work out so neatly

        • Hey there, big boy!

          *wave*

      • Re: (Score:2)

        by HiThere ( 15173 )

        IIUC, that's not a new interpretation, and it is a consistent interpretation. One of many, with no real way to choose between them. That it's "increasingly popular" is something that I'd require a bit of proof about. OTOH, as long as all the interpretations predict the same observations, there's no real reason to prefer one over another. The summary, at least, didn't mention any such observations, and I haven't happened to hear of any elsewhere.

    • Re: (Score:3)

      by Entrope ( 68843 )

      You're probably thinking of the delayed choice quantum eraser [wikipedia.org]. The takeaway quote there:

      While delayed-choice experiments have confirmed the seeming ability of measurements made on photons in the present to alter events occurring in the past, this requires a non-standard view of quantum mechanics. If a photon in flight is interpreted as being in a so-called "superposition of states", i.e. if it is interpreted as something that has the potentiality to manifest as a particle or wave, but during its time in flight is neither, then there is no time paradox. The superposition of states is the standard interpretation of quantum mechanics, and recent experiments have supported it.

      For more details, see the "Consensus: no retrocausality" section of that page.

    • I'm just reading on this on Wikipedia: https://en.wikipedia.org/wiki/... [wikipedia.org]
      "Observing that photons show up in equal numbers at the two detectors, experimenters generally say that each photon has behaved as a particle from the time of its emission to the time of its detection, has traveled by either one path or the other, and further affirm that its wave nature has not been exhibited"
      I think this is rubbish. The photon is a wave until it interacts with something. The wave function describes that the photon g

  • I fully understand why this was submitted anonymously - I wouldn't want to own up to this drivel either.

  • At least we're keeping them off the streets (Score:5, Funny)

    by clawsoon ( 748629 ) on Thursday March 16, 2023 @11:16PM (#63377305)
    I guess we know what all the former string theorists are doing now.

  • Time is a dimension. There's no obvious reason why it has to glow constantly in one direction.

    Consider this: someone put you in a car on the highway, heading East. That's all you've ever known, going from West to East. Just because that is your experience doesn't mean that the rest of the universe is stuck in the car with you.

    • There's no obvious reason why it has to glow constantly in one direction.

      Actually, there is a reason time can only flow in one direction: entropy.

      • OK, but there's still no obvious reason why entropy is low in one direction and high in the other.

      • But entropic tendency is an emergent property of having random fluctuations occur among many particles with many possible microstates. It says nothing about, e.g., whether an individual particle can be created at t0 and then be absorbed t-1.

      • Re: (Score:2)

        by Jamu ( 852752 )
        Arguably entropy and the arrow-of-time are the same thing.

      • Re: (Score:2)

        by ceoyoyo ( 59147 )

        That's not the evidence you think it is.

        The fact that entropy is low in one direction explains why you *experience* time as directional. None of our theories, or experiments actually show that it is. We experience time as "flowing" because it's easier to predict the past than it is the future, a fact that is entirely explained by the fact that there's a low entropy state in the past.

      • There's no obvious reason why it has to glow constantly in one direction.

        Actually, there is a reason time can only flow in one direction: entropy.

        That doesn't prove your point at all. Yes, entropy increases in the direction of positive time. it also decreases in the direction of negative time. So what? Just because we can only move in the direction of positive time (increasing entropy) - this does not prohibit other phenomena that may move in the opposite direction.

        If you want a (poor) analogy, consider

      • Also, due to Noethers Theorem if time was a vector so should be energy. Which causes all kinds of complications.

    • Think of chemical reactions (specifically those related to dna and biochemistry) and what they would look like if time didn't flow forward as we understand it. Yes, time is a mathematical dimension, but that just means an additional variable in a matrix, not a space dimension, like up and down. So no, in the universe we live in time always flows forward, and thinking about what it would take to reverse the flow just think about uncracking an egg, is that an easy or a hard problem?

      • Think of chemical reactions (specifically those related to dna and biochemistry) and what they would look like if time didn't flow forward as we understand it.

        That's easy. The particles floating backwards would be called "anti-matter", and upon collision with matter, both would disappear. The math literally works like this.

  • Philosophers and mind and all of a sudden they know how to connect macrocosmos and microcosmos. The right question is: how many stamps the author has licked? Utter nonsense.

  • If you think you have a paradox, any paradox (QM, SR, GR, etc), then you are thinking about the problem incorrectly. Its the misunderstanding of Time that leads to most of these problems. So, it's the first problem you need to master for anything else to make sense.

    Backward in time causality is not only not necessary, it is even impossible, once you have the right definition of Time. If you understand Time you will understand why we even have a speed of light, and Time simply does not work the way you inst

    • Backward in time causality is not only not necessary, it is even impossible, once you have the right definition of Time.

      Ok, but how do you know, considering no one claims to have the right definition of Time? Not even Sabine Hossenfelder [youtube.com].

    • Re: Rule #1: There are no paradox's (Score:5, Informative)

      by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Friday March 17, 2023 @04:22AM (#63377501) Homepage Journal

      Never trust a social media poster who claims to know more than the experts.

    • So in summary, we do not understand time cube?

    • There is no quantum gravity? (Score:5, Interesting)

      by Roger W Moore ( 538166 ) on Friday March 17, 2023 @08:34AM (#63377879) Journal

      gravity can be understood as a physical process with full accounting of the energy flow, and it need not even be quantized.

      Claiming to have solved quantum (or non-quantum?) gravity is quite a bold statement. Care to publish your solution in a reputable physics journal so the rest of the field can see it too because this has been puzzling us for a long time? Also, I'd suggest laying off the capitalization of "time" like it's a proper noun - relativity tells us that there is no universal time and suggesting otherwise tends to be a bit of a red flag, along with claims of solving quantum (or not) gravity.

    • Re: (Score:2)

      by HiThere ( 15173 )

      That REALLY doesn't work.
      By that argument you could think of the universe as a huge state table, and each observation invokes a transition rule. That would work, and could handle any possibly observable universe. But it could handle ANY possible observable universe. There wouldn't be any reason to choose between them. And it could handle arbitrary state transition rules.

      You NEED a model that is consistent with your observations and which is as simple as possible, for some meaning of simple. Tha

  • ... and I saw nothing relevant to this topic. What's up?

  • Yeah I thought of this tomorrow, but sadly forgot about it yesterday.

  • No. I don't think in stilted phrases. (Score:3, Insightful)

    by greytree ( 7124971 ) on Friday March 17, 2023 @01:44AM (#63377407)
    "An anonymous reader quotes a report from Motherboard: Have you ever found yourself in a self-imposed jam and thought, "Well, if it isn't the consequences of my own actions"?"

    Well do you know, gosh darn, I would be amazed if ANYONE in the English-speaking world EVER thought a stilted phrase like that to themselves.
    Including the bad writers at Motherboard and bad "Editors" at Slashdot.

  • âoeThe solution to this, as everyone seems to have agreed without discussing it, is that we've got to quantize gravityâ

    When you get past the clickbait title and pop science fiction garbage commentary, you realize that this is definitely not what you think it is.

  • As a demonstration, this post has been created by the fact that you are reading it.

  • Its very confusing, isn't it? (Score:3)

    by Budenny ( 888916 ) on Friday March 17, 2023 @04:26AM (#63377505)

    We usually assume that for A to cause B, A must have happened. But things in the future, we usually think, have not happened.

    Retrocausation seems to assume that the future is there in the same way that the past is there. It would surely lead to total determinism.

    Is everything that we see and experience the result of past events which in turn are caused by future events?

    It would be a bit like the Calvinist view that we are all saved or damned already, regardless of what we do. They then had to denounce as heresy the views of such luminaries as John Naylor, who paraded on a donkey into the city of Bristol, and proclaimed that even if he lay with a thousand women it was no sin to him, because he had been saved already and nothing could change it.

    So they cut off his ears and put him in the stocks. One way to win an argument over theology.

    Retrocausality seems to give rise to lots of paradoxical conclusions like this, no?

    • Re: (Score:2)

      by ceoyoyo ( 59147 )

      Since different observers can disagree on when the present is, and thus what's in the future, Relativity more or less requires that spacetime exists. Quantum mechanics doesn't disagree, and both require that the laws of physics work equally well if you flip the sign on the time axis.

  • Really! (Score:5, Insightful)

    by oldgraybeard ( 2939809 ) on Friday March 17, 2023 @04:28AM (#63377507)
    "gain real traction among physicists and philosophers" Something tells me we are light on the physicists and heavy on philosophers.

  • No great surprise (Score:5, Interesting)

    by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Friday March 17, 2023 @04:52AM (#63377539) Homepage Journal

    Science has long favoured the block universe model, in which time does not flow but is static.

    In other words, science has long rejected common-sense ideas about time as simply not reflecting reality. Indeed, it has long rejected common-sense as simply not reflecting ANY aspect of reality.

    And, let's face it, the results tend to go along with the science.

    Now, onto this new view of time. Let's start with what scientists are NOT saying. They are NOT saying "this is how time is". They are saying "if QM and GR are both correct, THEN this is a property time must have".

    In other words, we don't know both QM and GR are correct, that is a hypothesis. This is an implication of that hypothesis. If it is testable, then it allows us to test whether they are indeed both correct.

    If the future does NOT influence the past, one of the two theories is fatally flawed. THAT is what scientists ARE saying

    Since both theories have made testable predictions that have been verified, we have no reason to reject either - yet.

    It also means scientists can now devise an experiment involving gravity and time, such that the predictions of QM and GR ONLY both match observations if the future influences the past, OTHERWISE one of the two models is falsified.

    This experiment, the absolute decider, is the 21st century equivalent of the 189h century tension between classical physics of the time and observation that led to relativity and QM in the first place.

    It seems to me that we'd be better off discussing what such an experiment might be rather than telling scientists what we think they should think. Especially when it's obvious that those criticising the conclusion don't understand what it was that was concluded.

    • Re: (Score:2)

      by Budenny ( 888916 )

      What I am not understanding is: how can something which has not happened (because its in the future) cause something which has happened?

      If it has happened, then that is determinism, the future has already happened and is fixed.... and Calvin was right?

      • Re: (Score:2)

        by ceoyoyo ( 59147 )

        What I am not understanding is: how can something which has not happened (because its in the future) cause something which has happened?

        That's not how it works. That's just substituting one "direction" of time for another. We accept that events in the future must be consistent with events in the past. If you think about it, it's not much of a leap to accept that events in the past must be consistent with events in the future. The only reason for assigning one set of events as the "cause" and the other as th

        • Re: (Score:2)

          by UpnAtom ( 551727 )

          Absent-mindedly downmodded you when I wanted to upmod you. This comment is to reverse that modding.

      • Right, such if I get my brakes repaired today, retrocausality would imply that I got into an accident tomorrow because I couldn't stop, so somehow I influenced myself to get the brakes repaired today and avoid the accident tomorrow.

        So if I do repair the brakes today, am I doing it because I just want to maintain my vehicle, or am I under some sort of future influence?

        Then throw in the block universe and the fixed future and that would seem to contradict the ability for retrocausality because I couldn't chan

    • Re: (Score:2)

      by nasch ( 598556 )

      And, let's face it, the results tend to go along with the science.

      Nit picking but I'd say it's the other way around.

  • Links (Score:5, Informative)

    by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Friday March 17, 2023 @05:01AM (#63377569) Homepage Journal

    Since the research link is broken, I chased the links that worked for more details.

    https://theconversation.com/qu... [theconversation.com]

    https://plato.stanford.edu/ent... [stanford.edu]

    https://link.springer.com/arti... [springer.com]

    https://phys.org/news/2017-07-... [phys.org]

  • "Who controls the past controls the future: who controls the present controls the past."

    • Re: (Score:2)

      by gweihir ( 88907 )

      Actually this was about controlling the _perception_ of the past, not about actually controlling the past. Whole different idea with regard to Physics. Potentially not different with regards to humans though at least some of them. Implanted memories (e.g. by criminal "therapists") are a thing.

  • This make perfect sense to me. In fact Iâ(TM)ve had this as a personal theory ever since the last episode of ST:TNG where they introduced anti-time. For me thinking about the idea that freewill is deferred to the future making the present deterministic. Why am I here in this world right now? Because the events now are required to be where I will be in the future thus that information must travel back in time to ensure that outcome.

  • I did not RTFA and am not a physicist but just a random person with a vivid imagination but that has not kept anyone on here from joining in the discussion, so here it goes :p

    It could just be some optimization in the simulation. It's kind of computationally expensive to update the position of every photon with each tick of the clock, especially since the vast majority of photons will travel in a straight line though empty space for billions of years. I can think of several optimizations but one of them coul

    • The whole "universe is a simulation" thing just pushes back the same questions by a step.

      Let's assume we are in a computer simulation. Ok, fine. That computer still has to exist somewhere in the "real" universe so all the same questions we have still apply.

      Being in a simulation solves nothing.

      • Re: (Score:2)

        by zmooc ( 33175 )

        Being in a simulation solves nothing.

        I disagree; taking into account that there's a very small chance that we live in a simulation can help solve questions because now we can think about them from the perspective of a computer programmer. What sets a simulation apart from a real universe it that it might contain artefacts introduced by optimizations. Retrocausality might be such a thing, a thing that's unlikely to exist in a real universe but not unlikely to exist in a simulation.

        Also, your statement relies on the assumption that the universe

  • I mean, come on. It is amply clear that there is some fundamental problem between Quantum Theory on one side and human existence on the other. Humans do not do "retrocausality". Quantum Systems may be retrocausal as long as they are unobserved and no human is in the loop anywhere. That would not even break anything. But mix the two and this idea is just bullshit.

  • Even though it may feel verboten to consider a future that affects the past

    The highlight above is mine because I find that to be a very interesting word choice. So what you're saying is that instead of going into the past and killing Hitler as a child to stop him, we just go into the future and kill somebody else. OK......

  • Please don't give Marvel any more fuel for crappy, convoluted films

  • Sure (Score:2)

    by nasch ( 598556 )

    Nothing else about quantum mechanics makes intuitive sense, so why not?

  • DUPE! (from the future)

    This article was already posted on Slashdot NEXT WEEK!

  • I feel sorry for them.

  • "Some writers (e.g., [16, 18]) propose that we avoid this appearance of retroâ'
    causality by adopting an antirealist view of the quantum state. If the quantum
    state does not represent a piece or property of reality, then there is no retrocausalâ'ity (or indeed any sort of causality) involved here, because there is no real effect."

    I think this is best. There is no need for unnecessary mysticism especially where you are not adding anything new and not making any testable predictions.

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