[HN Gopher] A growing number of scientists are convinced the fut... ___________________________________________________________________ A growing number of scientists are convinced the future influences the past Author : myth_drannon Score : 210 points Date : 2023-03-17 14:05 UTC (8 hours ago) (HTM) web link (www.vice.com) (TXT) w3m dump (www.vice.com) | the_gipsy wrote: | Well, of course, what happens tomorrow dictates what happens | today. It's hard to be sure about what happens tomorrow. Then | again it's hard to be sure about what happens yesterday. It's not | a one-to-one relationship, but there are striking similarities. | alphanumeric0 wrote: | I'm attempting to recall an analogy from a paper about this | subject. One of the authors gave the analogy of time being like a | river. If we are traveling down this river, and the river is | changing speed ahead (maybe due to rocks or a sharp bend), then | it is correct to say that the river is changing the past (our | present location in the river), since our speed would then start | to change as we approach the new point. | karmakaze wrote: | It does make explaining some things much easier, like the | "Delayed-choice Quantum Eraser"[0] experiment. | | Basically what's possible next is anything that can solve for | conditions set by the past, and some from the future. | | [0] https://en.wikipedia.org/wiki/Delayed-choice_quantum_eraser | tetris11 wrote: | I think it relates more to Wheeler's Anthropic Participatory | Principle[0], where multiple observers of some event in the | past, can influence it from the future. | | 0: https://en.wikipedia.org/wiki/John_Archibald_Wheeler | pif wrote: | > A growing number of scientists... | | Beware, getting from one to two is already a growing number! | taskforcegemini wrote: | that's actually a big jump, 100% increase | yonaguska wrote: | Very tangentially related, but we rewrite the past all the time. | mr90210 wrote: | Wouldn't that be a matter of perception and written history | rather than the factual past? | karpierz wrote: | What is the factual past? | | It's the extrapolation of models that we've created in the | present, but those models are only our best guess at the | truth. They may be revised in the future or simply not hold | for the past. | yjftsjthsd-h wrote: | What? No. The factual past is what actually happened. Don't | mistake the map for the territory. | mistermann wrote: | Can you point us to The Territory please? You see it, I | presume? | yjftsjthsd-h wrote: | My eyes are a fairly reliable map, but they're still not | the territory. That we are only able to perceive reality | by proxy doesn't mean that it doesn't exist, though, it | just means that we have to get used to using maps, while | remembering that they can be flawed. | nyc_data_geek1 wrote: | The factual past is what actually happened, history is what | we wrote down. | | Perception and reality are not in fact the same thing. | CalRobert wrote: | To be fair there is some disagreement over what exactly | "the past" _is_. | https://www.youtube.com/watch?v=GwzN5YwMzv0 discusses | this a bit. | karpierz wrote: | Can you show that there is a factual past without parsing | it through your perception? | | It was factual that the earth was 6000 years old, until | it wasn't. | danjoredd wrote: | I would argue that factual past is unprovable without | some sort of visual evidence, and even that can be | manipulated...especially with AI on the rise. The problem | with your point is that EVERYTHING is parsed through your | perception, and you can just as easily make the point | with the same logic that you can't prove that what you | are currently experiencing is present reality. | | What actually happened is unprovable without some layer | of trust once the event leaves the affected. For example, | I ate a grapefruit for breakfast. That is a fact. | However, I have tossed the peel away and I am | communicating that I ate it with a stranger over the | internet. For all you know, I could have eaten cookie | crisp. If you and enough people get together and | collectively believe that I ate cookie crisp, the public | belief will be that I ate cookie crisp. However, that | does not change the fact that I ate a grapefruit. | karpierz wrote: | Given that people can hallucinate/make up false memories, | you sure you ate a grapefruit for breakfast? | | So sure that regardless of what evidence you are | presented, you'd be certain that you ate a grapefruit. | Even if: | | - I showed you videoproof that you were eating a sandwich | for breakfast | | - we had all of your family say they were having | breakfast with you and saw you eating a sandwich | | - a doctor came and said "I analyzed your stool and found | no evidence of grapefruit" | | - we had a message, cryptographically signed by a key you | generated/controlled, that said "man this sandwich is | delicious" | | Even with any amount of evidence to the contrary, you'd | still believe that you ate a grapefruit? | | If not, then are you sure that it's fact that you ate a | grapefruit, or it's just that all current evidence points | to you eating a grapefruit? | danjoredd wrote: | Given that, there are two, and only two possibilities: | | Either | | -my perception of reality is inherently opposed to | objective reality | | or | | -the world, for some reason, is gaslighting me into | thinking I ate a sandwich and the objective reality is | that I ate a grapefruit. | | See, my problem with this "philosophy" that objective | reality does not exist is that it enables abusers. Have | you ever seen the movie Gaslight? Its a classic. This | poor woman lives with an abuser...someone who is | committed to making her think that she is crazy. He | contradicts everything she does and says, sets up | evidence to objectively prove that she only imagined | herself doing it, and keeps her under his thumb through | those means. In the end of the movie, its revealed that | none of the evidence is real and that she is sane. To | combat against these types of people, its important to be | sure of your own reality and only change if evidence is | overwhelmingly pointed in the opposite direction. Even | then, question these changes in belief heavily. | Otherwise, you will believe just about anything anyone | says. | nyc_data_geek1 wrote: | No, that was never factual. Radiocarbon dating gives us | evidence, factual without the lense of perception or | opinion. Saying the earth is 6000 years old is just | repeating propaganda. | yjftsjthsd-h wrote: | > It was factual that the earth was 6000 years old, until | it wasn't. | | This is the opposite of the example you seem to think it | is. The Earth has always had the same actual date of | origin. If it is not factual now that the Earth is 6,000 | years old, then it wasn't before either. The whole | argument here is that people's perceptions and reality | can in fact be different. | karpierz wrote: | > The Earth has always had the same actual date of | origin. | | Maybe, but I'm asking: can you show that peoples' | perceptions match/differ from reality, without relying on | perceptions being factual/reliable? | | If not, then how do you know that reality is fixed? | mr90210 wrote: | Let's say that you are convicted as a criminal, and | allegedly you were in a certain location and committed the | crime. | | If you were not there and didn't not commit the crime, is | that past to which used to determine your conviction | factual? | | Whether later you are proven not guilty, the past didn't | change, but rather our perception of it. | karpierz wrote: | You're begging the question. You started with: assume | there is a factual past of where you were. And then | argued: there is a factual past. | | I'm not enough of a skeptic to say "don't trust the | models of the past"; memory turns out to be a pretty good | model. So does carbon dating. | | But the reason you say "you were not there and did not | commit the crime" is because you don't remember being | there. Maybe you even remember being elsewhere. But that | doesn't mean it's true, memory is fallible. | | You might say that you even have photos of yourself | somewhere else at the time. But if there were photos of | you at the crime scene, would that change what the past | was? Maybe your memory is shoddy, or maybe the photos are | fake. | a_c wrote: | Maybe perception IS reality. | danjoredd wrote: | Thats pretty dangerous thinking though. Adolf Hitler | famously said "a lie told often enough eventually becomes | the truth" and then used that way of thinking to commit | horrible atrocities. | sjkoelle wrote: | but what is the metric signature??? | gatane wrote: | When you flip that dx/dt so it becomes dt/dx... | electrondood wrote: | I have also come to this conclusion. I have had experiences that | cannot possibly be explained unless at least some future events | already exist. | | This also explained the "probabilistic" nature of quantum | behaviors; it's only probabilistic to us because we are unaware | of the influence of future events. I now believe it's extremely | likely that the universe is superdetermined, and I gave up the | idea of actual free will long ago. | | Highly recommend "Time Loops" by Eric Wargo. | contravariant wrote: | Superdeterminism is a cop-out where the universe is | simultaneously the only existing one and the most common | possible one, for no obvious reason. | | But yeah we'd like to think there's just one past and multiple | different futures, but the fact that the laws of physics are | time-reversible kind of makes it unlikely for both to be true. | acyou wrote: | Could you please expand on the experiences that you have had, | that can't be explained without future events already existing? | strogonoff wrote: | If only physicists were a bit more curious about philosophy... | mistermann wrote: | It's a good idea, but how could they be, _in fact_? | raydiatian wrote: | A growing number of people are recognizing that this article was | published in VICE, which isn't exactly a reputable STEM magazine, | as punctuated by the fact that the article refers to theoretical | physicists as "people" or "scientists". | | You gotta think about the (stoner) audience this article was | written for, I wouldn't take too much stock in its conclusions. | isoprophlex wrote: | Cool theory... A bit too Asimov for me though | | https://en.m.wikipedia.org/wiki/Thiotimoline | richardw wrote: | Honestly it's been staring us in the face for 100 years. Light | doesn't experience time. We've known this for so long. Light is | created and destroyed in the same instant - across billions of | light years it happens instantly. For that to be true, what else | must be true? Must. | | There is no photon. There is just a wave. The interaction | probably (definitely?) depends on features of both the emitting | electron and absorbing electron. There is either retrocausality | or superdeterminism (or both). We don't know which. Right now | that's not important but scientific fashion has been refusing to | get this one thing. We'll learn so much once we move past this. | | Light going into a black hole? Research paper. | macrolime wrote: | I asked ChatGPT if it has any technological applications. No | ideas if its just bullshitting | | Retrocausality, or the idea that events in the future can | influence events in the past, is a concept that challenges our | conventional understanding of time and causality. Although it is | an intriguing concept that arises in some interpretations of | quantum mechanics, it is important to note that there is | currently no experimental evidence supporting retrocausality. | | As a result, it is difficult to predict how retrocausality could | be influenced or used in technology, since we have no concrete | examples of retrocausality occurring in the physical world. | However, we can speculate on how such technology might work if | retrocausality were indeed possible. | Communication: If retrocausality were real, it could potentially | be harnessed for faster-than-light communication or even | communication with the past. Such technology might allow us to | send messages or information backward in time, which could have a | significant impact on how we understand and interact with our own | history. Computing: Retrocausal computing could | theoretically be used to perform complex calculations more | efficiently by taking advantage of future outcomes or solutions | to influence the computational process in the past. | Energy production: If retrocausality could be controlled, it | might be possible to harness energy from future states of a | system and use it to power devices or processes in the past. | | However, it is important to reiterate that these applications are | purely speculative and based on the assumption that | retrocausality is a real phenomenon. Until there is experimental | evidence supporting retrocausality or a more comprehensive | understanding of how it might work, it is unlikely that we will | see any practical technologies utilizing this concept. | ibn_khaldun wrote: | The end is not unlike the beginning, in that it has been written | to exactitude. "The pen has been lifted and the ink is dried". | | Side note: does anyone remember when Vice was "fringe" in its | content? I mean, ten or so years ago... | q845712 wrote: | The first time somebody showed me an article in Vice it was | ~2010 and the article was about the style and fashion of how | bricks of heroine were being branded. so ... yeah. | mlindner wrote: | It's articles like this that make me realize why so many less | educated people think that science doesn't have rigor, is close | to religion, or can't be trusted. Science authors like this do a | disservice to science. | neets wrote: | Sounds like Rupert Sheldrake[1] is finally getting through to | people, | | 1. [A New Science of Life](https://www.sheldrake.org/books-by- | rupert-sheldrake/a-new-sc...) | pharmakom wrote: | Intuitively... we can't even do science without a notion of time | that advances. How can we make observations without there being a | concept of "something happened previously"? | | I think this is embedded in science itself. | ChancyChance wrote: | It's an article about QM. | | On Vice. | | About a QM thought experiment. | | On Vice. | | Why would there be any expectation of scientific rigor | whatsoever? | | "retrocausality, may seem like science fiction grist at first | glance" | | Stop there, vice. | agilob wrote: | Check other articles by the same author. | stametseater wrote: | Mostly a bunch of clickbait crap. | | > _" One 'Super-Earth' Could Destroy Our Own Planet, Study | Finds"_ | | > _A super-Earth existing in our solar system is so far | hypothetical, but its effects would be incomprehensibly | destructive._ | taylorius wrote: | Lars von Trier has entered the chat. | coldtea wrote: | Is there any point to the comment? Did Vice made the theory up? | richardw wrote: | https://en.wikipedia.org/wiki/Ad_hominem | mik1998 wrote: | I think https://en.wikipedia.org/wiki/Michael_Crichton#GellMa | nnAmnes... is applicable here. | mlindner wrote: | Technically, Vice isn't a human. | m463 wrote: | hmm... Vice might be incorporated. | nanidin wrote: | [dead] | krsdcbl wrote: | the comment may be superficial and dismissive without | pointing out factual issues, but ad hominem attacks are still | a very different thing than dismissing the credibility of a | publication that has a track record of misleading pop science | sensationalism | berry_sortoro wrote: | [dead] | dools wrote: | Spooky action at an instance | wisty wrote: | Human instincts only apply to the systems that they're "evolved" | to handle (or the systems we can readily observe and learn from). | | Think about big systems. The moon is a ginormous rock that's so | big it is visible from thousands of km away, but it just hangs in | the sky because it's moving so fast it can cheat gravity, but we | can barely even see it move. Or think about how a star can | somehow explode because it starts running out of fuel (and our | sun is just yellow hot - you can do that with a blow torch, but | it's powered by a nuclear explosion - I guess it's got quite a | bit of surface area?). And little things are even weirder, | consider how fast the proteins in your cells bounce around. Then | there's quantum - our gut intuition is so out of its comfort zone | it's basically meaningless. | myth_drannon wrote: | Right, something along the lines of Donald Hoffman's The Case | Against Reality | causality0 wrote: | The sun being classified as a yellow dwarf does not mean it's | "only yellow hot". You can observe that by going outdoors and | holding up a white piece of paper and noting it is not yellow | in sunlight. | | _powered by a nuclear explosion_ | | Not quite accurate. The nuclear fusion going on inside the | sun's core is not an explosion. In a nuclear explosion, a | significant fraction of the fuel in a given area is consumed in | an instant. The sun's core on the other hand only fuses its | fuel extremely slowly. Pound for pound, the sun's core | generates less heat energy than mammalian muscle tissue. It's | just that there's so much of it that the heat energy is | extremely well insulated. | kridsdale1 wrote: | The sun is the color it is because its surface is 5500 | Kelvin, which we have defined as white. The sun is cooler | than most visible stars, so it can be called yellow by | comparison. | stametseater wrote: | The sun appears slightly yellow because the atmosphere | scatters blue light more than the rest. The result is the | sky looks blue, the sun is slightly yellowish, and the | cumulative light (both directly from the sun and diffuse | light from the sky) is white. Outside the atmosphere, our | sun appears proper white. | dietrichepp wrote: | I used to work at camp. You didn't need to tell kids about | fire; they could figure it out. Don't touch the fire. | Flashlights were too complicated. It's night, a kid turns on | their flashlight, points it in their eyes, says "ow" and can't | see where they're walking until their eyes readjust. | Flashlights are beyond our instinctual understanding of how the | world works. | dekhn wrote: | it's funny you mention flashlights. NO matter how many times | I tell people not to point their flashlight at people's eyes, | it happens (by accident) over and over. It bothers me a lot | because I am very good at getting my eyes dark-adapted and as | soon as somebody flashes me, I lose about 10 minutes of dark | vision. | QuercusMax wrote: | Maybe this is just because the kids had prior experience with | fire (touch it = ouch), but no experience with flashlights? | ocimbote wrote: | Yes. If we learned something about fire, it's to teach the | youngest ones to stay away from it. Nothing more. An | unattended and untaught kid will try it, at least because | it's nothing like they've seen before. | creeble wrote: | while I might buy that the past is strongly influenced by the | present ("facts" change over time), I don't think we have much of | a model for the future to say much of anything about how it | influences the past. | | Or, I guess the point is, maybe it's the same thing. | sophacles wrote: | So it goes. | stkdump wrote: | If time were symmetric, wouldn't that mean instead of causality | (future is influenced by the past) and retrocausality (past is | influenced by the future), there is no preference and in effect | no causality at all? A&B are necessarily connected, but none of | them is the cause of the other. | CuriouslyC wrote: | If you think of it as a series of states with some prior | probability, and jumps from state to state also have some | probability, it isn't so much causal as correlated. | | If time is a true dimension and reality is the most probable | universe when integrated over all of time, improbable states | and transitions might occur in the "past" in order to enable | high probability states and transitions in the future. | bartimus wrote: | This is 'What the Bleep!?: Down the Rabbit Hole' all over again. | Just because something happens in Quantum Physics doesn't mean | humans can influence their pasts. | Lucent wrote: | Another point for my favorite minority quantum mechanics | interpretation, two-state vector formalism (TSVF). | bookofjoe wrote: | Where can I read the report? | LudwigNagasena wrote: | https://arxiv.org/abs/quant-ph/0105101v2 | m3kw9 wrote: | Maybe in a microscopic way like at quantum level | hummus_bae wrote: | [dead] | wootland wrote: | As a non-physicist I'm not sure I'm interpreting this correctly. | Does this essentially mean that all states in time already exist | and our consciousness is just traversing this 4D space in one | direction on the time axis? | | If so, does that mean that the big bang could actually be the end | of the universe and we're just experiencing time in "reverse" | toward an initial starting state that we perceive as the future? | Nevermark wrote: | While most laws of physics may be time symmetric, the laws of | thermodynamics are not - wherever there is a gradient in | entropy. | | In very informal terms, anywhere where there is very low | entropy (higher order), any direction away from that will | likely (to the point of certainty) be in a direction of higher | entropy (lower order). | | For instance, if you have a jar of red & blue marble, with high | order (such as perfect alternating layers of red vs blue | marbles) then any disturbances (such as shaking the jar, | reaching in and moving a handful, ...) will almost certainly | reduce order. | | And no practical amount of shaking the jar will ever return the | marbles to a high order state again. | | Even though any close up video of the marbles being jostled | will reveal the same physical properties and behavior for the | marbles, whether played forward or backward. | | So at the individual marble level, laws are symmetric. | | But at the jar of marbles level, one direction of time looks | very different than the other. | | We, and the particles that make us, and our environment, are | the marbles whose configuration is more disordered the further | in time we get from the Big Bang. | | So we perceive the time direction away from the Big Bang as the | future, toward the Big Bang as the past. | | And the statistical "force" of increasing entropy provides the | useful energy we use to survive, learn, create useful islands | of order, in the greater sea of increasing disorder. | dekhn wrote: | Not sure if you appreciate this, but if you repeat the | shaking experiment enough times, you will see it return to | perfect order- at some exceptionally tiny probability. I'm | pretty sure you are saying that but instead of "practical | amount", it's easier to say it's just exceptionally unlikely. | mftb wrote: | So I think I understand this argument and it makes sense to | me (at the moment). To me the (to paraphrase), "increasing as | we move away from the big bang" stuff seems to lead right to | the idea that the expansion of the universe is what we | perceive as the passing of time, but I never hear any one | knowledgeable say that. Is there some obvious reason that | it's not that succinct? | lordnacho wrote: | That all makes sense, but why does cause and effect seem to | go one way with the entropy arrow? | soperj wrote: | > And no practical amount of shaking the jar will ever return | the marbles to a high order state again. | | This can't be true. Take the case where there's only 2 | marbles, it's likely that at some point that shaking them | will return them to the original state. For higher numbers of | marbles the probability becomes lower and lower, but is never | 0. | a257 wrote: | With enough marbles, the discrete distribution behaves like | a continuous distribution. The point probability of a | continuous distribution is infinitely improbable -- in | other words it is 0. | | (0.00..0..1 = 0 just as 0.99 repeating equals 1) | soperj wrote: | There can't be an infinite number of marbles in a finite | amount of space. | a257 wrote: | The number of possible states asymptotically approaches | infinity, so we can model it as such. You can get a more | "accurate" model using more math (with measure theory), | but the terms will coalesce such that they are | negligible. | soperj wrote: | negligible isn't zero, and time at a universe scale may | be longer. | TechBro8615 wrote: | > infinitely improbable -- in other words it is 0 | | This sounds like a rather bold statement to make, as long | as we're already speaking so metaphysically. | a257 wrote: | The statement is mathematically correct [0]. | | [0] https://stats.stackexchange.com/questions/142730/px-x | -0-when... | TechBro8615 wrote: | We're talking about physics, not mathematics. We don't | have the luxury of hand-waving away fundamental questions | about the nature of the continuum. | | See: https://en.wikipedia.org/wiki/Continuum_hypothesis | a257 wrote: | Please elaborate. | TechBro8615 wrote: | I'm neither a mathematician nor a physicist, so I'm not | nearly informed enough to elaborate on the subject | properly, but I would note that the axiom of choice is | not proven, and while you can mathematically divide a | continuum into infinitesimally small sets, you cannot do | the same to physical matter. From my understanding, many | of the contradictions between classical and quantum | physics arise at this boundary between the discrete and | the continuous, where classical physics generally assumes | continuity while quantum physics is constructed around | discrete quantization mostly independent of time. | | Again, I'm not a physicist, but I think it's telling that | the validity of continuum mechanics [0] depends on a | _model_ and multiple _assumptions_. I have no trouble | agreeing with your original statement, "with enough | marbles, the discrete distribution behaves like a | continuous distribution," _when speaking mathematically_ | , but mathematics by its nature is an idealized model of | the world - I'm not willing to accept that it's | objectively representative of physical reality. The | discussion we're having here is one of metaphysics, so it | feels a bit like the height of hubris to use mathematics | as the tool for describing objective reality, because | metaphysically, we cannot say that mathematics is | anything other than a tool we've constructed for | approximating the model of the world as we understand it. | Considering the subject of this post is about | retrocausality, we're already throwing out some pretty | wild ideas, so I think it's a bit hubristic to dismiss | them by citing a branch of mathematics that assumes the | existence of countably infinite sets [1]. | | [0] https://en.wikipedia.org/wiki/Continuum_mechanics#Val | idity | | [1] https://en.wikipedia.org/wiki/Constructivism_(philoso | phy_of_... | coldtea wrote: | > _We 're talking about physics, not mathematics._ | | Mathematics still apply. | TechBro8615 wrote: | Mathematics applies insofar as it can model the subject | under discussion. It's a great tool for, dare I say, | 99.999999...% of practical problems. But mathematics is | an imperfect model of objective reality that cannot | resolve metaphysical problems like Zeno's paradoxes [0]. | Any discussion of retro-causality is inherently one of | the philosophy of space and time, which is the domain of | metaphysics, not mathematics, so we can't necessarily | apply familiar mathematical lemmas to resolve the | problems it creates. | | [0] https://en.wikipedia.org/wiki/Zeno%27s_paradoxes#In_m | odern_m... | | [1] https://en.wikipedia.org/wiki/Philosophy_of_space_and | _time#D... | PartiallyTyped wrote: | Any point is infinitely improbable when sampling with | infinite precision, only because this calculation is not | computable. | | Even if the point probability is 0 or approaching zero | very fast, some event occurs with probability 1. | | The probability that life would evolve on a blue planet | that its anthropomorphic inhabitants will come to call | Gaia or Earth, has as a star Sol, in this corner of the | Milky Way, in this particular local group and so on is | zero even if we limit ourselves to just the observable | universe. | | At the same time the probability that life will exist at | some planet at some solar system at some galaxy at some | local group and so on, is practically 1. | | That is to say, depending on how you categorise and count | said marbles, the reordering may occur. | | While any individual marble will not be at its place with | P=1. You can still end up in a situation where the | marbles are ordered in layers. | | The whole thing regarding entropy is concerned with a | closed system. You can very much exchange energy to | decrease entropy, but said exchange is a) leaky, and b) | implies that the system is not isolated. | a257 wrote: | A probability of zero does not mean that the event is | impossible. When we refer to probabilities we are talking | about probability densities. Infinite precision is a | useful modeling tool in the same way that approximations | of pi are useful. | dekhn wrote: | In a well defined system, a probabiltiy of zero _by | definition_ means an event is impossible. | PartiallyTyped wrote: | I think I was misunderstood. My comment regarding | infinite precision was mostly aiming to argue that any | single point has probability zero but an event still | occurs. | | This was then used again when mentioning earth to argue | that depending on the definition of "order" here: | | > And no practical amount of shaking the jar will ever | return the marbles to a high order state again. | | It is entirely possible to reach a state of higher order | if you don't require that individual marbles don't hold | the same arrangement relative to adjacent marbles, | meaning that any permutation of marbles with identical | color is acceptable. | | This happens because the event you are asking for is a | very large subset. | dekhn wrote: | you're correct. In stats/thermo class there's a commonly | taught "what's the probability of all the molecules of air | in a room spontaneously moving to <extremely small | location>". The problem is that shoving all those molecules | into a tiny location woudl increase the pressure | tremendously, sending all the particles in directions that | would eventually return to a uniform distribution. | | IIUC my professor right the probability is non zero but is | practically impossible for a large number of incompressible | spheres. | theGnuMe wrote: | I like this concept. Is there any sci-fi based on this premise? | gpuhacker wrote: | Surely reminds me of Harry Potter and the Prisoner of | Azkaban, where Harry is saved by himself as he at some point | in the future travels back in time to save himself. | idleproc wrote: | Not sci-fi, but the block universe is central to Alan Moore's | Jerusalem. | __MatrixMan__ wrote: | Greg Egan - A Clockwork Rocket (book 1 of the Orthogonal | trilogoy, all three of which I recommend) | e12e wrote: | The Nolan film "Tenet" is based entirely around the idea of | reversible causality. | myth_drannon wrote: | Aliens in the movie Arrival perceive time in circular | fashion, basically live in future and past. | [deleted] | andsoitis wrote: | And the movie is based on Ted Chiang's novella, "Story of | Your Life" | MayeulC wrote: | Just saying, this is a pretty big spoiler. | jspank wrote: | Reminds me of the Tralfamadorians from Slaughterhouse-Five. | They are able to see in four dimensions so humans appear as | fetuses at one end of the four-dimensional person and dying | at the other end. | | https://en.wikipedia.org/wiki/Tralfamadore#Slaughterhouse- | Fi... | imsaw wrote: | Interesting concept. I wonder if it's compared with spatial | 3D space, then how large would the 4th dimension of time be | if it were to fit the timeline of a human lifespan | kelseyfrog wrote: | A natural interpretation leads to time being very large | and us moving very very fast through it. | | It's convenient to model our movement through space-time | as occurring at the speed of light. Thus, the faster we | move in space, the slower we move in time all the while | the length of our space-time velocity vector is | invariably c. We can then imagine 1 second of time being | interchangeable with 299,792,458m. | photochemsyn wrote: | The 'Dirac Beep' in this short novella (1973): | | https://en.wikipedia.org/wiki/The_Quincunx_of_Time | | Also, the concept of causality itself is a kind of underlying | theme in Hannu Rajaniemi's "The Causal Angel" (2014) (3rd of | a series). | quijoteuniv wrote: | You can wish yourself well in the past. I believe this works. | electrondood wrote: | You're actually the lamination of what you typically consider | to be yourself, across all time periods in which you exist: a | 4-dimensional spacetime worm. | __MatrixMan__ wrote: | I think of personal growth as a conspiracy between present | me, past me, and future me. Where our motives are aligned, | good things happen. | quijoteuniv wrote: | This is good! And ask for help from the future :) | figassis wrote: | Allow me to steal this bit of insight | __MatrixMan__ wrote: | I'm just another incarnation of you anyway, so it's not | even stealing. | RajT88 wrote: | Past me leaves future me notes. | | I often find them insightful, especially if I am reviewing | them again years later. | layer8 wrote: | Several things: | | - The laws of physics are essentially time-symmetric, and they | have no concept of causation or of a preferred direction of | time. In principle, the future causes the past as much or as | little as the past causes the future. Physics effectively only | says they have to be _consistent_ with each other, as related | by the laws of physics. | | - The _apparent_ directionality of time that we perceive is | suspected to be tied to the entropy gradient we are on. See the | "past hypothesis" for example [0]. | | > Does this essentially mean that all states in time already | exist and our consciousness is just traversing this 4D space in | one direction on the time axis? | | - I would say that all moments in time are equally real, | including our consciousness at any given moment. There is no | actual flow or "travelling". The flow we perceive is merely an | illusion caused by the fact that we only remember the past and | not the future (which again may just be a consequence of the | entropy gradient we are on). This is known as the "block | universe", or as "eternalism" [1]. The opposing view that only | the current moment is real, and that the future differs from | the past in its "realness", is known as "presentism". | | - Note that any notion of "travelling" through time implies | that you can draw a 2D diagram of where in time you are at each | point in time, or which point in time is "real" at which point | in time (in the sense that a moment in time isn't real until | time reaches that moment, but after that it is real and cannot | be made unreal again), thus implying two dimensions of time. | That doesn't make any sense, and thus my personal conclusion is | that the "presentism" view is nonsensical. | | [0] https://en.wikipedia.org/wiki/Past_hypothesis | | [1] | https://en.wikipedia.org/wiki/Eternalism_(philosophy_of_time... | kwhitefoot wrote: | The block universe: https://plus.maths.org/content/what-block- | time | Apocryphon wrote: | Is it the same thing as the holographic universe theory that | was in vogue a couple of decades ago? | | https://i.pinimg.com/originals/27/d7/8c/27d78c9c3ee93c13eda4. | .. | icegreentea2 wrote: | No. The block universe is that 3+1D spacetime "exists all | at once". We just happen to experience travelling through | it in one way. | | Holographic universe is that the physics and information in | a 3+1D space time could be encoded into a 2+1D universe | (with it's own physics). | Apocryphon wrote: | Ah, _Discover_ had an issue about that as well | | https://www.discovermagazine.com/the-sciences/from-here- | to-e... | | https://i.ebayimg.com/images/g/xH8AAOSwryZi3Ef0/s-l1600.j | pg | __MatrixMan__ wrote: | Must it be "the" time axis? Might it instead be "our" time | vector? Maybe there are alien civilizations right next door | which we fail to recognize as life because our time vector is | orthogonal to theirs. Instead they're just gamma ray bursts to | us. | [deleted] | MayeulC wrote: | Interestingly, the norm of your 4D speed vector is constant, | IIRC: https://en.wikipedia.org/wiki/World_line | plebianRube wrote: | I try to tell my 'past' self events that have occurred. | | I also try to listen to any future 'self' notifications. | | It's mostly a fun thought experiment. | kwhitefoot wrote: | > In addition to potentially rescuing concepts like locality and | realism, retrocausal models also open avenues of exploring a | "time-symmetric" view of our universe, in which the laws of | physics are the same regardless of whether time runs forward or | backward. | | Usually the fundamental laws are regarded as time symmetric | already. | | What does this mean: > Instead, retrocausal models suggest that | there is a mechanism that allows circumstances in the future to | correlate with past states. | | Surely future states inevitably correlate with past states? | | Perhaps it all makes sense but that article doesn't make a | compelling case. | QuadmasterXLII wrote: | We don't have a time symmetric model of wave function collapse, | to my knowledge. If I'm wrong I'd be super curious to read | about it | throwawaymaths wrote: | We don't have a model of wave function collapse at all, iirc. | GoblinSlayer wrote: | Just reverse time in the evolution operator. | bioemerl wrote: | Wouldn't many worlds be time symmetric? | layer8 wrote: | Yes, but it's not a model of wave function collapse. Its | very premise is that there is no wave function collapse. | orbifold wrote: | Measurements are adjoint to state preparation. Depending on | what you measured you can prepare a special state at that | time to make the system time reversal symmetric. | derbOac wrote: | Not an expert in this area at all but there have been some | experimental findings in the last five or so years that suggest | the possibility of retrocausality. | | This is just one example I found but I think there might be | another experiment from a few years ago that was getting some | attention at the time (although I might be confusing it with a | theory paper): | | https://www.nature.com/articles/s41598-023-29970-6 | | There are probably better overview articles on retrocausality. | | https://www.newscientist.com/article/mg23731652-800-quantum-... | | https://aeon.co/essays/can-retrocausality-solve-the-puzzle-o... | | https://phys.org/news/2017-07-physicists-retrocausal-quantum... | | I'd have to read through all these more thoroughly but I wonder | if there's some "time locality" property in these models? | coldtea wrote: | > _Surely future states inevitably correlate with past states?_ | | He means to correlate through effects going the future -> past | direction... | jonny_eh wrote: | > It may seem eerie to our brains, which process events | sequentially, but the history of science is also littered with | examples of human biases leading to bad conclusions, such as the | Earth-centric model of the solar system. | | Slow down. Assuming that time moves in one direction is not | comparable to geocentrism. | macrolocal wrote: | It's comparable to GPT4 being shocked that we can read | backwards! | whatshisface wrote: | It is because in both cases, you can work out that you'll never | make an observation that really proves it one way or the other, | but you might come up with some laws of physics that are more | conveniently expressed in one way than another. They're both | ultimately questions about your coordinate system, and in fact | it is easier to invert time than it is to work out how | everything's supposed to function in a rotating+sun- | orbiting+precessing+... coordinate system. | nanidin wrote: | If we reverse time and this implies running everything | backwards in physics, do we include gravity in the set of | things that are reversed? Then everything would fly off the | face of the earth in reverse-time. | whatshisface wrote: | Let's check. | | F = ma | | F = m dv/dt | | u = -t dv/dt = -dv/du | | - F = m dv/du | | If you stop there it looks like you're right, but you also | must change the definition of velocity to account for the | new time. | | v = dx/dt = -dx/du | | +F = m dx/du | | So the direction of gravity (the force F) stays the same | when you flip time. I can explain that without the math by | pointing out that if you took a video of a ball being | thrown up and caught and played it in reverse, it would | still depict a ball being thrown up and caught. | nextaccountic wrote: | > I can explain that without the math by pointing out | that if you took a video of a ball being thrown up and | caught and played it in reverse, it would still depict a | ball being thrown up and caught. | | That's amazing, thanks. The portion where you caught the | ball in forward time is equivalent to throwing the ball | in reverse time. | | I need to rewatch Tenet some day | novaRom wrote: | I watched it 4 times. Only then I started to understand | what's happening. How great and unique this movie really | is. | mkl wrote: | I felt like I understood it the first time, but didn't | think it was very good. Was that your initial reaction? | nanidin wrote: | If we change the analogy of throwing a ball to firing a | gun into the air - does the analogy still work? Since | when we fire the gun up, the bullet will travel faster up | than it will travel down due to terminal velocity in | forward time. How is that phenomenon explained in reverse | time? | whatshisface wrote: | Instead of predominately striking the bullet in a way | that causes it to slow down, the molecules in the air | will predominately strike it in a way that causes it to | move faster, in what looks like an unbelievable (but | still physically possible) run of good luck. | kgwgk wrote: | In the way down -sky to gun - the molecules in the air | will give it energy to accelerate more than gravity alone | would. Before that - in the way up - air molecules will | cause it to move upwards at constant speed until | conveniently they stop doing so. | | > unbelievable (but still physically possible) | | Physically possible - but in the same sense that the | second law is not a physical law. | nanidin wrote: | So it seems like if we reverse time, we reverse entropy | and that as time approaches 0, we would effectively be | reversing the big bang and instead have the big collapse. | | Another thought experiment that comes to mind is | compressed gas in a cylinder. When we open the valve, the | gas in the cylinder comes out. In reverse time, the gas | would go back into the cannister and the valve would | close after the gas went back in. Very low probability of | that happening in forward time, though not not 0. | | Though it seems weird, because why does the gas go into | the cylinder? Because further into reverse-time, | something sucked it all out (in forward-time, this | machine is the compressor that put the gas in the | cylider.) This hurts my brain! | theemathas wrote: | Reversing time on an attracting force _still_ gives you an | attractive force. Velocity is reversed, but acceleration | isn 't. | | Imagine a ball being thrown up and then falling down, in a | parabola. Reversing a video of that still gives you a video | of a ball in a normal parabola trajectory. | [deleted] | entropicdrifter wrote: | Gravity is a universal constant. If you reverse time, you | just reverse the order of cause and effect, not _what the | effect is_. | | Does that make more sense to you? | nanidin wrote: | If we reverse time, would gravitational waves flow | backwards? | dekhn wrote: | yes. it's literally like playing a movie in reverse. | nanidin wrote: | " it's literally like playing a movie in reverse" seems | overly authoritative for something we haven't observed. I | have seen Tenet, but it's a work of fiction. | | Have we observed reflected gravitational waves? In | reverse-time, where would they originate from if they | presumably rippled out into space and didn't collide with | anything in forward-time? | dekhn wrote: | .... they would "originate" from all the locations the | gravity waves spread to and converge on the source. | | Tenet has nothing to do with this- I'm just explaining it | as it was covered in my many physics classes that covered | the nature of the arrow of time | (https://en.wikipedia.org/wiki/Arrow_of_time) and how I | interpret it in terms of what seems most likely/least | unlikely. | bigbacaloa wrote: | "gravity is a universal constant" contradicts Newtonian | mechanics, special and general relativity. | nanidin wrote: | In these "it's like taking a video of throwing a ball in | the air and allowing it to land on the ground, then | playing it in reverse" examples, I can't help but think | of Newton's first law. If an object at rest stays at | rest, how does the ball leap from the ground? Where does | the impulse come from? Reverse time seems too far fetched | for me, or at least the simplified naive version of it | does. | bnralt wrote: | It also seems a bit misleading, since in that scenario a | ball is intentionally thrown so that it comes down the | same way. | | Let's consider something else - imagine an accretion disk | of space dust slowly pulling itself together to form a | planet. Play that in reverse, and you have the a planet | slowly coming apart piece by piece. Imagine reversing the | impact that created the moon. The moon comes apart piece | by piece, creating an accretion disk around the earth, | which then all moves and hits one area of the earth, and | there several parts of it (and part of the earth itself) | move together to form a separate planet, which then | launches itself from the earths surface into space, flies | around the sun a few times, and then slowly breaks apart | piece by piece into another accretion disk. | sidlls wrote: | It isn't because we have the observations we have. It might | be mathematically easy to invert time, but empirically it's | not so simple. Mathematical symmetries and expressions are | nice, but then the actual physical consequences and | requirements (e.g., material, time, energy inputs) sort of | force one's hand. | | Also, geocentrism is actually disproven by numerous | observations, which in fact guided the mathematical | formulation of our current physics. | | One thing is (almost) certain: the laws of physics as we know | them (i.e. the Standard Model and General Relativity) are | incomplete ("wrong"). That doesn't mean any old model is | equivalent or as useful as either, though. | whatshisface wrote: | > _Also, geocentrism is actually disproven by numerous | observations, which in fact guided the mathematical | formulation of our current physics._ | | The validity of a coordinate system with the earth | stationary at the center is guaranteed by the general | principle of relativity. To get the stars to circle around | it you would add a radially increasing potential in | classical mechanics, or some coordinate shenanigans in GR. | These coordinate systems are used in aerospace engineering | to get convenient expressions of L1 points, etc. | | I know it sounds hard to believe, but if you're willing to | bite the bullet that "the center of the universe" has no | physical meaning, then earth can't be _not_ the center of | the universe any more than it can be. | prerok wrote: | To be honest, I have no idea what you are talking about. | | Certainly, there is merit in practical calculations when | we are all this close to the ground where it all seems | either flat or at least geo-centric. | | But... the movements of the other planets in our solar | system were really strange to model in geo-centric | models. In short, each of the other planets should rotate | around an imaginary axis to compensate for their changing | positions in the sky. | | Of course, all this is talk about in the context of our | solar system. As for us being the center of the universe, | well, the same argument holds for any other point in the | universe. So, I think it's less likely than me winning | the lottery in the next five minutes :) | felipeerias wrote: | In the XVII century, the alternative to heliocentrism was | Tycho Brahe's model: Earth at the centre, the Sun and | Moon and the stars revolving around it, and the other | planets revolving around the Sun. It was basically | equivalent to the heliocentric model with a different | coordinate system. | | It's important to understand that astronomers chose it | because it really seemed to provide a better explanation | given the knowledge and technology at the time. | | Tycho Brahe himself noted that his model could be | disproved by observing the stellar parallax effect as the | Earth orbits the Sun (if the Earth does move, then the | stars would look slightly different throughout the year). | This is a real effect, but so small that it couldn't be | observed until the XIX century. | ben_w wrote: | > I know it sounds hard to believe, but if you're willing | to bite the bullet that "the center of the universe" has | no physical meaning, then earth can't be not the center | of the universe any more than it can be. | | I disagree. | | The sentence <<"the center of the universe" has no | physical meaning>> _requires_ that Earth can 't be at the | center of the universe, because there isn't a center for | it to be at. | | You're still allowed any or many arbitrary zero-points, | but that's only the center of a number line, nothing | else. | whatshisface wrote: | It's basically a semantic issue but I don't think the | negation of an undefined proposition is true, I think it | is undefined. (Thankfully the universe does not run in | JavaScript, where !undefined _is_ true.) | jskulski wrote: | We may not be able to observed it, and maybe can't. Just | like time slowing down would be imperceptible to the person | on the spaceship nearing light speed. It takes the | mathematics | | Or if I'm lucky enough to have the time to watch the moon | move slowly, it feels natural to my senses to say it's | moving across the sky. The moon feels like it's moving | around me. But I can stretch my brain and imagine the | reality. | | Sometimes math arrives first. We have the new maths (or an | problem in current math), and that points to some | possibility. Because it's not observable, ignoring our | senses is a requirement to develop that in the model and | measurements and experiments. Eventually we are able to | observe it. | | I'm not familiar with history of astronomy. Would it be the | case where the observations that lead to heliocentric | thought we nuanced and had to build on more obvious | perceptions that things aren't adding up? Was the wobble of | Venus part of that? | | And you're right, old models are useful and remain relevant | a lot! The model of time moving linearly will likely always | be the most useful model for navigating our daily choices | (if we have any at all!) | bsder wrote: | > Slow down. Assuming that time moves in one direction is not | comparable to geocentrism. | | Why not? | | The "arrow of time" almost always requires thermodynamic | arguments. And that requires a concentration of "low entropy" | to move toward "high entropy". Which, by definition, are | "boundary conditions" and not a fundamental part of your | physical rules. | | If, for example, your universe is entropically uniform, is | there an "arrow of time"? And, even if there were, could you | detect it? | | However, I would like to point out that it's not like we | haven't had this kind of issue before. The Bohr-Einstein | debates were a good example. Einstein favored a "fields" | interpretation of quantum mechanics. Unfortunately, Einstein's | interpretation predicted that atomic states wouldn't decay, and | that was clearly, obviously wrong, and Bohr very much hammered | on that. | | Except that Einstein wasn't "clearly, obviously wrong." As you | increasingly isolate excited atoms, their atomic states take | longer and longer to decay. The problem was that the | experiments of the day couldn't create these kinds of singular | quantum state systems--they were stuck with systems that were | contaminated with lots of thermodynamic interactions. | | We may be seeing something similar here. We are just starting | to be able to put together the experiments that can probe | things like Bell's Inequality. As we isolate these systems, we | may find that the systems were contaminated with statistical | time and that we get different results when we can isolate | them. | kgwgk wrote: | > If, for example, your universe is entropically uniform, is | there an "arrow of time"? And, even if there were, could you | detect it? | | What does that even mean? If your universe is entropically | uniform there is no "you". | CuriouslyC wrote: | Geocentrism seemed reasonable until it didn't. | | If time is a true dimension rather than just something we model | as a dimension, it's not unreasonable to think that outcomes in | the present could be influenced by constraints that exist in | the future - if the "universe" function must be valid according | to some constraints at all points in the time dimension, "past" | states that lead to invalid future states will never occur. | | The idea of invalid universe states is of course purely fun | conjecture, but this same concept also maps to probable vs | improbable universe states as well. If a future state is | improbable (in the sense of a Bayesian prior according to some | underlying distribution of energy in the universe) that might | cause the universe to evolve in a way that seems improbable at | the moment by moment level, but is actually the most probable | sequence of events when integrated over the entire duration of | the universe. | bmacho wrote: | > Geocentrism seemed reasonable until it didn't. | | Literally nobody "assumes" that "time moves one direction" | (which is not even a statement). There are models, where t is | a real number, which models are sadly very very good models, | but they are not perfect (therefore not true). Noone believes | that Newtonian mechanics, QM or GR are true. QM fails to | correctly predict the movement of the planets, and GR fails | at the two-split experiment. | | But then there are literally thousands of physicists that try | to come up with different models. | | How is this even remotely similar to geocentrism? | willis936 wrote: | Time could move backwards if we lived in a time symmetric | universe. We don't. Maybe if you flipped the charge and | handedness of the entire universe you could also reverse time, | but that's yet to be tested. | | https://youtu.be/L2idut9tkeQ | 0xBABAD00C wrote: | Here's the analogy, per Sean Carroll [1]: | | - There seems to be a special direction "down", where things | fall by default, because we live in the vicinity of an | influential object in space, called Earth | | - There seems to be a special direction "forward in time", | where things happen by default, because we live in the vicinity | of an influential event in time, called Big Bang | | If we had stuck to the local Earth context and geocentrism, the | objectivity of the "down" direction would remain unquestioned. | It's when we started modeling other things outside of Earth, it | became clear there's no objective "down" direction, just a more | general concept of Gravity. | | Carroll's argument is that it's the Big Bang, an extremely low- | entropy configuration of the universe, that gives rise to the | 2nd Law of Thermodynamics and the resulting emergence of an | arrow of time in the forward direction. It's purely a | statistical phenomenon at larger scales, and attributable to | being "next to an influential event", according to him. | | [1] https://www.youtube.com/watch?v=AZsmyTE3j9o | photochemsyn wrote: | It's difficult to see how such a hypothesis could be tested | either experimentally or observationally. Sounds more like | metaphysics? | | Stars shine until they run out of fuel, and the age of a star | - the status of its fuel, the buildup of fusion products - | happens as time passes. Life on planets taps into the flow of | sunlight from the star (and/or the flow of heat and chemical | energy from the a hot planetary core) to generate complex | structures in defiance of the regular direction of entropy | (not violating conservation of energy, though). So... life | reverses the arrow of time? | K0balt wrote: | I think that one thing to keep in mind is that we are only | capable of observing the passage of time along one vector | because our perception relies upon entropic biological | processes. | | We cannot observe in any subset of possible universes where | entropy is not present or is working backwards-Ergo those | possibilities are wholly out of our direct perception. | | That does not mean that causality cannot run in reverse, | however, only that we cannot interact with those mechanisms | in a way that would preclude our existence or observation. | DubiousPusher wrote: | But could we observe the effects? Can there be particles | which have mass and therefore exhibit gravitation but | which are subject to reverse entropy? We would observe | these for example as an unexplainable increase in | gravitational pull on observable matter without an | observable source of that gravitation and without a | preceding cause. | | Are photons themselves stratling this entropic boundary | since they travel at the speed of light and within their | own reference frame are not subject to the passage of | time? | prerok wrote: | Well, of course not :) Entropy as direction of time just | means that the chaos on the whole increases. So, to create | an ordered structure, like a cell organism, the by-product | is more chaos around it. | ashirviskas wrote: | To add, life just speeds up the chaos by orders of | magnitude, it's a perfect entropy catalyst. | kergonath wrote: | I'd be shocked if that were the case, even only | considering the Earth. The oceans and the atmosphere are | full of entropy. So is the liquid outer core. And even if | the mantle is not quite liquid, and even if the crust is | mostly solid, these are _huge_ in terms of volume and | mass, much larger than the sliver of dirt we inhabit on | top of them. So yeah, I really doubt we (collectively, | all human beings) are changing the Earth's entropy in any | meaningful way. | zone411 wrote: | Life reduces local entropy. | prerok wrote: | I think that the real question is whether the death of the | universe by cool down will happen before the arrow of time | is reversed. To me it seems more like it will just slow | down and then finally stop. | SirYandi wrote: | Or if there ever is a "big crunch" where all black holes | crunch together to a critical mass, would there be | another big bang and time then run backwards? | DubiousPusher wrote: | The hypothesis I have encountered is that time would | reverse when the expansion of the universe peaked and | started to collapse back in on itself. The next big bang | would start another run of our universe. I'm guessing the | randomness in quantum fluctuations would allow this next | run to evolve somewhat differently from the one we are | experiencing. | klipt wrote: | Right, entropy can decrease, just with low probability, which | you can calculate using the Fluctuation Theorem: | https://en.wikipedia.org/wiki/Fluctuation_theorem | | Perhaps given infinite time, we will randomly get back to a | low entropy state infinite times, but I don't know enough | about the math to say for sure. | ben_w wrote: | You can, but that inevitably leads to far more Boltzman | brains than things like the universe, and that's disastrous | because then you should expect to be a Boltzman brain | yourself, but they're configured randomly so if you are a | Boltzman brain you can't trust any belief you have about | reality including the maths that says you should be a | Boltzman brain. | | It's basically a softer version of Russell's paradox but | for cognition and reality. | psychphysic wrote: | I don't think Carroll can take credit for the idea of the | arrow of time being emergent from a local entropy initial | state. | | Roger Penrose proposed that as far as I know, when Carroll | was probably a high schooler. | mellosouls wrote: | _Roger Penrose proposed that as far as I know, when Carroll | was probably a high schooler._ | | No. At least as early as Arthur Eddington when Penrose was | a twinkle in his dad's eye. | yeahwhatever10 wrote: | Explaining an idea is not equivalent to taking credit for | it. | psychphysic wrote: | > Carroll's argument | | This assigns credit to Carroll. | Jcowell wrote: | It merely says that Carrol argued. The idea within the | argument was no means assigned to her but _used_ to make | /support it. | zone411 wrote: | This idea of time's relation to entropy is pretty iffy. I | recommend this book | https://news.berkeley.edu/2016/09/20/new-book-links-flow- | of-.... | platz wrote: | who's taking "credit" | [deleted] | epgui wrote: | I disagree, I think the comparison is pretty reasonable. | | Your entire experience of the world is defined and limited by | the fact that your brain "only processes information in one | direction of time" (for lack of better wording). Your personal | experience does not necessarily map correctly to the real | world. The same is true for both examples. | brwck wrote: | It's not just a matter of our subjective experience of time, | it's a matter of the laws of thermodynamics and entropy. Time | moves in one direction is another way of saying entropy | always increases. If time could move in the opposite | direction, then entropy decreases which breaks our | understanding of physics. | VeninVidiaVicii wrote: | It's really interesting to think about how we struggle to | express the idea of the future having a causal impact on | the past. I reckon this is because our language and our | understanding of time are limited. | | Our brains like to process events in a linear sequence, | from past to present to future, but this view of time might | not fully capture how everything in the universe is | interconnected. It's possible that our language just can't | handle these complex concepts. | | So, I don't think anything mentioned in this thread | contradicts the idea that "time always moves in one | direction" and "entropy always increases". | dasil003 wrote: | Right. "Time only moves in one direction" is not saying | much more than "our consciousness experience time moving | in one direction". The very idea that time "moves" is | entirely related to our vantage point. If our perception | were not bound to time, then the nature of cause and | effect might look completely different. | Trasmatta wrote: | I don't think the idea that "the future can influence the | past" is the same thing as saying that entropy decreases or | that time can move in the opposite direction. I think these | are different concerns | yyyk wrote: | The comparison is bad all around. Geocentrism actually had | decent reasoning and was not a superstition. It's just we | couldn't see the parallax with then-current instruments. As | soon as instruments allowed, humanity changed rather quickly. | Notatheist wrote: | Time moving in one direction actually has decent reasoning | and is not a superstition. It's just we can't detect time | moving backwards with now-current instruments. As soon as | instruments allow, humanity will change rather quickly. | yyyk wrote: | The problem with the comparison is what it's used to imply. | The popular understanding* is that scientists believed in | religious dogma, and that led them to 'unscientific' | geocentrism and believing that time has only one direction. | It's a backhanded accusation of superstition, and that's | unfair towards both current scientists and past scientists. | | (On a personal note, I'm actually sympathetic to the | article's retrocasual proposition. I suspect reality is | non-local and TSVF etc. naturally tend towards non- | locality.) | | * This is _Vice_ , of course they use the popular | understanding and not something more sophisticated. | 7thaccount wrote: | Yep. Someone else already pointed out the well known | counterargument to symmetry below regarding thermodynamics. You | typically don't see scrambled eggs become whole again. I think | that's pretty hard evidence to overcome. | | Granted, I'm not a physicist and I'm sure any physicist working | on this totally understands that. Just wanted to point it out. | resource0x wrote: | If the direction of time is reversed, the eggs become whole | again, but your memory of them once being scrambled is | reversed, too, so you don't notice anything unusual. | | (It's like a rollback of database transaction, where not only | the database state, but also the state of everything, | including your brain, is getting rolled back) | fortyseven wrote: | That would suggest a kind of "super timeline" I'd imagine. | beiller wrote: | If the future could affect the past, it suggest that then | if time reversed, you would notice something unusual right? | Kind of like suggesting there is a side effect in your | function (consciousness). Kind of like how today, past | events can influence the future like we act differently | from learning from mistakes. | 7thaccount wrote: | But is there any evidence of that? Or is it just a thought | experiment? I need to read more of the article, but | appreciate you giving me some food for thought. | resource0x wrote: | It's a thought experiment, of course. There cannot be any | evidence one way or the other, by definition. Any | potential evidence is rolled back, too. But then, why are | we so sure our current beliefs WRT the arrow ot time are | true? | | Though there's no hard evidence, but if you think, for | example, about the efficiency of evolution - it would be | much easier to explain if we assume that the unlimited | number of iterations is performed. (This is not the only | possible explanation, of course- but this one is | overlooked IMO) | | I would say that compared with the strange ideas like | "multiverse", this one is rather benign :-) | kridsdale1 wrote: | Scrambled eggs can become whole again by being consumed by | insects, who are then consumed by chickens, who then lay | eggs. | | The biological processes enabling that sequence can be said | to have negative entropy. | dekhn wrote: | Negative entropy (also called negentropy) isn't really a | well-defined concept. Instead, better to say that | biological processes harvest free energy to maintain order | in the face of increasing entropy. | aeternum wrote: | The argument is that thermodynamics is simply a statistical | phenomenon. Scrambled eggs are due to proteins denaturing | (folding in a random way). | | Scrambled eggs do actually unscramble spontaneously if you | zoom in far enough. The issue is that the rate of scrambling | is much higher than the rate of unscrambling so on the whole, | you get scrambled eggs. | | The amazing thing is that all chemical processes are actually | reversible given enough energy and finesse. | seydor wrote: | Assuming that time "moves" kinda is | weknowbetter wrote: | Nothing actually moves according to Zeno's paradox. | Ygg2 wrote: | Zeno's paradox assumes space is infinitely divisible. | kelseyfrog wrote: | they didn't understand limits | [deleted] | narrator wrote: | The Transactional Interpretation of Quantum Mechanics also says | this[1]. Retrocausality and non-locality are why a lot of | physicists don't like it. It's just an interpretation too, but is | otherwise consistent with all other QM theories. | | [1]https://en.m.wikipedia.org/wiki/Transactional_interpretation | jklinger410 wrote: | Mandela effect moment | garbagecoder wrote: | I am fascinated by physics but my original background is math. | This all seems fascinating but also sort of baroque and far from | experiments like much of QM and GR lately. | [deleted] | acyou wrote: | The idea that there are "causes" and that there are "effects", | and that these are separate and distinct, is in some way on a | parallel with the idea that the past influences the future, and | vice versa. If we think that the past influences the future, then | it's just as reasonable to think that the future influences the | past. Personally, I view "causes" and "effects" as abstractions | that we use to help interpret our complicated world, nothing | more. | | That's not to say that it's not legitimate to talk about causes | and effects and to reason using them, but when seriously | considered, anything that absolutely looks like definitely a | cause or an effect, needs to be considered again with the system | boundaries re-drawn, that is to say, with the system boundaries | drawn around the whole universe. | | Take for example the cigarette lighting the forest on fire. | Saying that the cigarette caused the fire is as much of a value | judgement and political statement as saying that the decades-long | drought caused the fire, or that humans causing global warming | caused the fire, or that the cigarette companies caused the fire, | or that God caused the fire. The emotional response that each of | these statements elicits in various people should tell you that | any statement linking cause and effect is emotional and political | at its core. This reflects the nature of the humans that create | these statements. | | We have a built-in tendency to try to assign causes to events and | effects. We should zoom out enough to understand that this is | part of our humanity, not part of the way that the universe | works. | prof-dr-ir wrote: | For this community it might be useful to stress that the vast | majority of practicing theoretical physicists is not in the least | worried about any interpretation of quantum mechanics. | | I would argue that the idea instead is to try to make predictions | for future experiments. In the case of quantum gravity, | especially string theory, these might be thought experiments | (what happens if you fall into a black hole), technically | infeasible experiments (what would a particle accelerator with | the size of the solar system produce), or even completely | hypothetical (what if the universe would have eleven macroscopic | dimensions) but that does not change the underlying mindset. | | When it comes to the interpretation of quantum mechanics there is | just nothing _left_ to explain. There is no experiment that | decides between different interpretations, so that is _it_ as far | as most physicists are concerned. | | The ideas in the linked article suffer from the same fate: there | does not seem to be even a hypothetical way to test them, and the | topic is therefore considered one of philosophy more than | physics. | eternauta3k wrote: | Still, can't alternative formulations inspire new physics? Like | Lagrangian/Hamiltonian formulations of classical mechanics | making the step towards QM easier? | peter_d_sherman wrote: | >"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." | | Linguistics: _retrocausality_ -- is going into my 2023 lexicon... | mtlmtlmtlmtl wrote: | Why would I want to read about science in Vice, as someone | actually interested in physics, but knowledgeable enough to | understand a talented science communicator(with a PhD in the | field) like Sean Carroll or Rebecca Smethurst. | | What purpose does it serve to write sloppy interpretations of | complicated, likely to not pan out hypotheses(almost always the | case) on quantum mechanics? | | So if this doesn't pan out, all they accomplished was that now a | bunch of people are walking around with wrong information. | | If it does, then we'll find out eventually anyway. | | Science journalism is not useful to scientists, not helpful to | nerds like me and for the masses it only contributes to | misinformation and miseducation. | | There are plenty of talented communicators with advanced degrees | in their fields that can do this job better, and journalists | should go do their jobs which is the opposite of regularly | misinforming the public(inb4 cynical reply hurr durr journalists | always misinform about everything <direction> wing media herp | derp. Not interested.) | ford wrote: | There's an interesting short story "Story of Your Life" by Ted | Chiang that is related to this concept. | | It was the motivation for the movie arrival (though IMO is much | better - the movie adds some drama that does not exist in the | short story) | [deleted] | smrtinsert wrote: | Phenomenal film. Full of interesting ideas and heartache. Pairs | well with Annihilation. | nathias wrote: | on the quantum level sure, but on the macro level it's just | idealism | zoogeny wrote: | The final episode of Star Trek: The Next Generation played with | this concept [1]. | | 1. | https://en.wikipedia.org/wiki/All_Good_Things..._(Star_Trek:... | andrewfromx wrote: | "It's important to emphasize at this point in time, whatever that | means, that retrocausality is not the same as time travel." | | The funny line there is at this point in time. The whole article | is about how the future influences the past so... at some point | in time retrocauslity will be the same thing? | kazinator wrote: | The laws of physics are symmetric in time in classical Newtonian | mechanics already. E.g. a swinging pendulum looks the same in | time, forward and backward. | | What's not symmetric is in the area of thermodynamics and | statistical mechanics; E.g. we never observe shards of glass | spontaneously reassembling into a window pane. | gexaha wrote: | In philosophy this idea is called "hyperstition" | gfd wrote: | I used to believe that the world is lazily loaded. That means the | first moment I see something (e.g., a world map) is the point | where all the past history to consistently explain the | observation gets "locked in". | snozolli wrote: | That was proven not to be the case: | | https://www.scientificamerican.com/article/the-universe-is-n... | sdwr wrote: | Sounds like that link supports the idea? | snozolli wrote: | Only if you didn't read the article, though I agree that | the scientists' choice of terminology is confusing for | regular people. | orbz wrote: | Wave function collapse in effect? | Red_Leaves_Flyy wrote: | What changed? | carlmr wrote: | That's still lazy loading, he hasn't looked into it yet. | KwisatzHaderack wrote: | I feel like this assumes solipsism. | Spivak wrote: | Multiplayer solipsism. That part of the game doesn't load | until at least one player observes it. | sdwr wrote: | Was coming to say something like this. Gets to some fun | conclusions - ex. paleontologists invent dinosaurs by looking | for them. | | Another angle on it would be showing that the universe has | multiple possible levels of detail - that objects behave like | newtonian point masses most of the time, that digestion is | replaced by a simple hunger meter when nobody's paying | attention. | | From this direction, time's main function is compressing "now" | so there's more space for something else later. | | I'd be willing to believe that everyone has a god-given amount | of universe rendering time that can be allocated in different | ways, and that other people's attention stacks with it in a | complex, layered way. | TechBro8615 wrote: | This thought experiment implies that humans, or conscious | agents, represent a highly concentrated source of entropy, | currently (mostly) confined to planet Earth. Meanwhile, in | the vastness of space, most of the mass has settled into some | relatively deterministic equilibria, with no conscious agents | to alter the course of its future. Yet we're down here on the | blue planet messing everything up. | | Coupling this thought with the simulation theory, it makes me | wonder how the simulation would respond to increasing entropy | over a larger volume than just our local system. That is, if | we send a bunch of biological/artificial agents in all | directions throughout the cosmos and let them wreak havoc, | would it crash the simulation? Or what if we just smash a | bunch of asteroids out of their stable orbits and let their | disruption cascade throughout the system? Or maybe we've | already messed everything up by broadcasting highly entropic | radio waves throughout a spherical volume with a radius of | ~100 light years? | sdwr wrote: | My guess is it would conserve entropy/processing on Earth | to match the increased cost. | | But there's a difference between "screaming into the void", | like broadcasting radio waves, that presumably have 0 | effects, and other things. | polishdude20 wrote: | That would also mean that when I don't see or hear other | people, they don't "exist" as physical things that can be | seen or heard until I encounter a situation in which they | would be. | | It's the same as "If a tree falls in the forest and nobody is | around to hear it, does it make a sound?" | | But then again, that information has to be stored somewhere | right? | | Like, if a tree falls in the woods and nobody is around, sure | you can say it isn't being perceived so it won't be | "rendered" but the moment someone walks in the forest and | sees that fallen tree, it would need to be rendered from some | information about the fall and information of how it looked | before the fall. That information would have to be sitting | somewhere in limbo waiting to be rendered. So why not just | actually let it sit IN the rendered "realm" and now you have | one place for data to live in. You save on data transfer fees | too. | mywittyname wrote: | > But then again, that information has to be stored | somewhere right? | | As a collection of probabilities stored as a wave. | | If a bank account has a 50% probability earning a penny | every second, the bank doesn't need to store all of the | intermediate values for every "clock tick", but instead | calculate how much has accumulated since the last time | someone checked the account and store that value with a | timestamp. | polishdude20 wrote: | Where is this wave stored though? And what is the wave | made of? A wave of what? | sdwr wrote: | The idea is that the universe "cheats" by replacing a | computationally expensive process (a tree falling, breaking | into pieces, being eaten by insects, moss growing) with a | series of cheaper, "good-enough" replacements, based on the | level of scrutiny. | | Not existing is the cheapest. | | Then, broad strokes, location and orientation | | Then pieces, level of decay | | etc, | | and moving between the layers is you spending your | attention budget to force the universe to do more work. | dbtc wrote: | 'the world' vs 'my world' and 'your world' | SMAAART wrote: | Alfred Adler would agree with retrocausality. | kevin_thibedeau wrote: | This would perfectly explain deja vu. | huetius wrote: | Would this put concepts from classical philosophy like formal and | final causation back on the table? The article seems to imply | that it's possible, but I've learned that journalistic summaries | can be low-fidelity. | [deleted] | marcus_holmes wrote: | Interesting because it messes with the school of thought that | everything is determined already and we're just following a | sequence of actions that arise from the starting conditions of | the universe. If causality is broken then maybe we have free | will? | GoblinSlayer wrote: | If causality is broken, that means hard indeterminism. | electrondood wrote: | Causality isn't broken; the universe is "simultaneously causal | and teleological," because it's superdetermined. | | There also isn't any free will, because there isn't actually | any agent who could have it. Actions we perceive as volitional | actually arise in the brain up to 7s before we "choose" them. | The sense of a "me" is a post hoc add-on that claims credit for | everything, in order to unite the disparate phenomena that | comprise the sense of self. | | There isn't actually any "me," and recognizing this is what the | word "enlightenment" refers to. | anotherman554 wrote: | It could just mean causality has more dimensions than we can | perceive. It doesn't mean it is nonexistent. | marcus_holmes wrote: | So my decision to have a ham sandwich for lunch is determined | by some meta-universe that created the starting conditions | for this universe, and allows for the breach in causality? Or | somehow is involved in the backwards-arrow of quantum events | that the article talks about so the universe cannot turn out | any other way? | | I dunno, seems like a "God of the gaps" thing - we can | speculate on meta-meta-universes endlessly. Including one | where my decision to have a ham sandwich disturbs the state | of a yet higher dimension that sets the starting parameters | of your higher dimension and once again I have free will. | paulusthe wrote: | That's a very lazy school of thought though. It's just | atheistic Calvinism, a tautology masquerading as a | "philosophy". | | Calvin believed in pre-destination (your fate and every | decision you make is decided before you exist) on the grounds | that, because God exists and is omnipotent, what you are doing | must therefore be what God wants to happen, both good and bad. | After all, God is omnipotent, so there you go. | | Today's Calvinists just replace God-driven destiny with nature- | driven destiny, but the underlying tautology (X exists, | therefore X was always destined to exist, as proven by the fact | that it exists at all) remains the same. In fact, it's an | arguably more ignorant version of Calvinism, because it | requires that one completely dismisses any knowledge they have | of probability theory. So it's the "smarter" Calvinism that | requires you be ignorant of 20th century mathematical advances. | | Hate that crap. The only people I hear talking about it are | silicon valley utopians, which is probably the other reason I | hate it. | flanked-evergl wrote: | > In fact, it's an arguably more ignorant version of | Calvinism, because it requires that one completely dismisses | any knowledge they have of probability theory | | No to pick too many nits, but I think it is well established | that knowledge of formal sciences (i.e. mathematics) does not | impart knowledge about natural sciences (i.e. physics). While | maths a useful tool, there are no established rules of | inference for reality, and without rules of inference you | can't really make claims on infinite sets. | | Natural sciences allow us to find mathematical constructs | that make good predictions within specific constraints or | that have not yet been falsified, just because something is | true in probability theory does not make it true in reality. | anotherman554 wrote: | If humans lacked free will, probability would still be | useful, because humans use it when they have imperfect | information about an upcoming event. | jandrewrogers wrote: | I don't follow this argument. The coexistence of probability | theory and strict determinism create no issues in modern | mathematics. | yamtaddle wrote: | > In fact, it's an arguably more ignorant version of | Calvinism, because it requires that one completely dismisses | any knowledge they have of probability theory. So it's the | "smarter" Calvinism that requires you be ignorant of 20th | century mathematical advances. | | I entirely fail to see how probability theory means it's | impossible for the universe to be deterministic. | explaininjs wrote: | Scott Aaronson's "Ghost in the Quantum Turing Machine" tackled | this question in a way I found enlightening. It's a bit of a | dense read (I needed a plane trip to sit down and focus on it), | but it presents a compelling case for the possible reversal of | time arrows when it comes to the effects of quantum | indeterminism on macro scale interactions. In short: what if | humans, somehow, someway, have the ability to "influence" the | resolution of unobserved universal start-state quantum noise in | order to affect our "will" onto the universe? Furthermore, what | experiments could be done to validate or invalidate aspects of | this hypothesis? | | https://arxiv.org/abs/1306.0159 | marcus_holmes wrote: | That seems crazy - that my decision to have a ham sandwich | for lunch had to be propagated all the way back to the start | of the universe in order to happen ;) | | And yes, provability is a major problem with all these kinds | of theories. We don't have a parallel universe handy as a | control, and just saying "I am not going to have a ham | sandwich tomorrow" isn't a viable experiment. | explaininjs wrote: | I interpret it as a sort of entropic antennae... each | person (brain? qbit?) is tuned into what might be | considered an allocated "entropy bandwidth". Some | decisions, like whether you eat a ham bandwidth tomorrow | utilize* practically none of that bandwidth. Others, what | you might consider "major life decisions" might utilize* a | ton of bandwidth. Some people might be gifted with a | "larger" antennae, allowing them to utilize* a higher | amount of entropy per second, or per lifetime. We might | call these great artists, or generally any genius-level | intellectuals. Alternatively, bat-shit crazy people. | | *: On "utilize". A central debate ( _the_ central debate?) | seems to be what sort of "state access mechanism" this | maps to in our lexicon: "{reading|writing} | {global|local|shared} {bandwidth|memory}" | why-el wrote: | My favorite sentence on free will comes from Chomsky (who I | think was probably quoting someone else): "if we don't have | free will, then why are you arguing the point?" | layer8 wrote: | The compatibilist view is that there is no contradiction | between free will and determinism, because free will refers to | macro states and determinism refers to micro states. | | In addition, in the many-worlds view of quantum mechanics, we | don't follow just a single sequence of events, but all | physically possible sequences of events, where the points where | sequences branch off each other can correspond to different | decisions we "freely" took. Meaning, when we make a decision, | _all_ applicable options of choice will become actual reality. | user81436628 wrote: | [dead] | a_subsystem wrote: | Well... yes. | | http://gurdjiefffourthway.org/pdf/GURDJIEFF%20AND%20TIME.pdf | echelon wrote: | I just need retrocausal information on the stock market, world | events, and any threats to myself or my monopoly on retrocausal | information access. That's all. | Rediscover wrote: | Perfect response for the subject being discussed -and- your | user name -and- a summary of your namesake from of a couple of | amazing books by Charles Stross. | | I applaud You. | | https://en.m.wikipedia.org/wiki/Singularity_Sky | mtmickush wrote: | If the information is truly retrocausal you won't be able to | leverage it to alter the future :'(. | 1970-01-01 wrote: | This idea is present in several Star Trek episodes. The meta | question is when did we create those episodes? | GravitasFailure wrote: | I misread your username as a timestamp and was very, very | confused for a minute. Very appropriate in this context. | excalibur wrote: | > "You have to be very careful in a retrocausal model because the | fact of the matter is, we can't send signals back in time," Adlam | explained. "It's important that we can't, because if we could, | then we could produce all sorts of vehicles or paradoxes. You | have to make sure your model doesn't allow that." | | This rings false to my scifi-trained brain. Paradoxes emerge when | information about the future allows you to change it in some way. | But if the future is truly immutable, there's no reason why you | can't learn what it will be. Any attempts you make to alter it | will only result in the exact thing that you already knew would | happen. | | Maybe I'm misunderstanding the author. Maybe what they MEANT to | say is if you didn't already receive an email from your future | self 5 years ago, then you can't send one today that your past | self will receive at that time. Just as the future is immutable, | so is the past. But if we had some sort of quantum email that | allowed for such a thing, it WOULD be possible to go check it | today and find a message from yourself 5 years in the future. | mjhay wrote: | I'm guessing it's in terms of quantum information. Quantum | entanglement and tunneling can happen faster than the speed of | light, which causes similar time paradoxes with special | relativity. This is avoided by the impossibility of sending | observable classical information. Two entangled objects can | affect each other, but you can't get actual information about | it, because it is destroyed upon observation. | ardit33 wrote: | "Manifesting" -- maybe those girls that are into it, are right ;) | dsego wrote: | World-line travel my friend | | https://metallicman.com/detailed-breakdown-of-consciousness-... | okasaki wrote: | Isn't it just a matter of perspective/terminology? | | If in my physics theory I redefine that past=future and | future=past then I have a physics theory where the future | influences the past, and very strongly so. | mikewarot wrote: | Recently, I came across the Feynman-Wheeler handshake[1-ish], | which lead to the Transactional Interpretation[2] of quantum | mechanics, which lead to the Afshar experiment[3] | | I've come to conclude that all of these are consistent, but that | they are a _metaphorical truth_ , in that you shouldn't interpret | them as literal truth. | | Gun safety advocates teach "All Guns are Loaded", another | metaphorical truth. If you behave as if it were true, you will | generally live longer, and be safer. | | The math underlying quantum mechanics has all sorts of non- | intuitive interpretations, and is often used as a gateway to woo- | woo theories. I'm allergic to woo, and thus treating all of this | as a metaphorical truth works best for me. | | [1] | https://en.wikipedia.org/wiki/Wheeler%E2%80%93Feynman_absorb... | | [2] https://en.wikipedia.org/wiki/Transactional_interpretation | | [3] https://en.wikipedia.org/wiki/Afshar_experiment | didericis wrote: | This comment will probably give you hives, but the inability to | interpret things like QM literally and the inability of the | left brain to process things holistically seems relevant to the | interpretability problem. See Iain McGilchrist's "The Matter | with Things". (I promise it's less woo-woo than it appears) | shkkmo wrote: | You have confused "metaphorical truth" with "heuristic". You | can actually verify that a specific gun is not loaded and thus | know for certain that not all guns are loaded, this (among | several other things) means it really isn't metaphysics at | all.. | | Metaphysics are u ___________________________________________________________________ (page generated 2023-03-17 23:00 UTC)