Or, more precisely: 1) measure spin 2) depending on spin, either do nothing, or choose whether to negate the spin based on the message you want to send 3) ??? 4) measure the spin again, and compare to your initial measurement 5) profit
@@drdca8263 oh so like: 1) measure the spin of an electron 2) depending on the spin, either bounce the electron back through the polarizer or just like, let it do it's own thing, be free little electron! 3) do this with a ton ton ton of electron 4) Well doing this, measure the spin of the electrons and compare them to your initial measurement 5) award the nobel prize money to drdca, hydrowolfy, and whichever Dr Weisenberg who built the other side of the device since he had this idea before either of us and would probably have done exactly this idea. I suppose the only question I'd have is, which one of the single world liners is gonna pony up the prize money. That's how Nobel prizes work right?
@@hydrowolfy I was just saying the same thing as OP’s joke but with more detail from the video included? No extra detail which was not in the video (except if I remembered part of it wrong and included such an error in what I said) I was just being pointlessly pedantic about a good joke.
this really reminds me of the short story "Anxiety is the dizziness of freedom" by Ted Chiang. In this story people were able to communicate with a parallel universe by a similar machine as described here. they could then send and receive a limited number of information of their parallel self. by this they could see how other versions of themselves reacted to specific events and eventually how their lives changed based on that decision. Good read, I really recommend it to anyone who enjoys more "grounded" scifi stories
Man, imagine the reaction of the guy that sees the results from that test. Knowing that somewhere, somehow, a darn near 100% identical version of yourself is experiencing the exact same feeling, the feeling of knowing that you exist and have just communicated with them. That may very well be the most world shattering discovery to ever be made, if not just knowing that there are other worlds, then by the sheer implications of what's now likely possible within our own world.
@@karsonio3543 this is my deepest hope for any future discoveries. It will mean superpowers, horrors beyond our wildest imaginations, unbelievable fantasies will come true, and more. So much more…
Consider that by whatever cascading contrivances of a differing quantum event, there's a whole set of realities where he's still alive, and within them he's wholly unaware of the realities where we are now mourning him. If the "many worlds" interpretation is correct, that is.
I wouldn't want a many-worlds phone because the worse versions of me wouldn't want to be depressed, and the better versions of me wouldn't want to be disturbed.
It's math and logic. And it always leads to multiple universes, nothing else. Even if this universe were cyclical, there would still be an infinity of others concurrent with this one
"The definition of insanity is doing the same thing over and over again, expecting different results." Of course, Einstein would not have said that because that is not the correct definition of "insanity". It is, however, a valid description of "practice".
No. That's the definition of Newtonian physics. Expecting different results everytime but in its probability is the definition of quantum physics. Probably something like that?
@@tTtt-ho3tq but newtonian physics is deterministic, so it wouldn't make sense to expect different result from the same experiment. in fact you would expect the same result each time. but if you practice, you feel like you're doing the same thing but you're actually getting better at it
'"The definition of insanity is doing the same thing over and over again, expecting different results."' No, we actually do that thing, since we need to find the statistical properties of the ensemble of a random process, and each observation is a different realization of the ensemble.
@@حَسن-م3ه9ظ not true. To the extent that I know of it. Penquinz0 did a great video on it. There is legitimate proof that there is altercations made to the name.
I had no idea Steven Weinberg passed away just 3 weeks ago until I saw 1933-2021 in this video!!! So sad, I got to meet the guy in a guest lecture once, physics has lost a giant!
The stand-in dude for "You" and "Other You" who appears around 10:47... seeing them pop up occasionally in your videos is just such a delightful highlight for me. They're so wonderfully goofy and the various expressions we sometimes see on their face just adds a welcomed silliness. Do they have a name, I wonder?
The short story "Anxiety is The Dizziness of Freedom" by Ted Chain explores this concept in a philosophical way and I LOVED it. I recommend it to everyone here!
The story is every bit as real and scientific as it is philosophical in my opinion. And it's such an original view that it was exactly what I thought of when I saw this thumbnail.
Clicking on a PBS Space-time episode is like going on a trip! I'm not always keen on leaving my comfort zone but when I do, I always have a good time!! And space!!!
"Pythagoras talked about x^2+2xy+y^2 things. The real story, though, is part of our infinite, and sometimes quadratic... spacetime." -- Matt Dowd, 494 BCE
Hugh Everett and his family has the most tragic story, truly heart-breaking. A troubled genius.. His son is the front man of a band called "eels". If you haven't heard them, give them a listen.
Good, now I can try my luck with my crush from an alternate universe. Oh, nevermind, she said she's dating my other self. Lucky bastard! Edit: much love from Brazil!
I'm writing a science fiction story that involves using such a non-linearity device to peer into other worlds when a baddie makes contact with the heroes who have to prevent an invasion. They ultimately do so by transmitting information to a distant world line before its event of no return transpires. Got the idea from a dream which was probably influenced by the novel Timeline by Michael Crichton and from PBS Spacetime which I've been watching for over 6 years, and you continue to give me ideas
So, there are three different “flavors” of quantum mechanics according to the nature of the Schrödinger equation: A boring linear one, a non-linear spooky communication at-a-distance one, and another non-linear one where you can phone individual bits across the multiverse. If only 1 is correct, then it seems that a theory of quantum gravity might be able to explain which version is compatible with our universe. How does this affect different candidates for a theory of quantum gravity? Is there any candidate only compatible with one version? Can such a theory, if confirmed, rule out the incorrect two? Or can any theory of quantum gravity be made compatible with any version of the Schrödinger equation?
I like this question! I don’t have any answers for you. I think I’ve heard people talking about quantum gravity maybe requiring some nonlinearity (though I’m pretty sure there’s no consensus that it does, and my guess is that the majority view is that it doesn’t require it, but my impression is that the idea that it might is seriously considered?)
Maybe not the right place to air this out but I hate when people say spooky action at a distance...a much better translation of the German Einstein used is uncanny rather than spooky, very big change in the connotations
Let us take this opportunity to acknowledge and appreciate the folks who make sure the Closed Captioning (for the hearing impaired) on this channel is SPOT ON. Names, terms, physic-speak, ALL properly captioned. 🤟🤟🤟
@@fenwickrysen yes, but not only the hearing impared. Some of us don't have a headset at the moment, are in public and are too polite to make everyone else listen against their will
Non locality is one of the weirdest aspects of quantum mechanics. During my undergrad physics curriculum, I took a course titled “philosophy of physics” that touched on all the different interpretations, and Philosophical aspect’s of QM. Non locality was one of those aspects. The idea that if you have a two particle system separated light years apart from each other, and the state of one of those particles is already pre determined when a measurement is performed is mind boggling.
It is indeed. I wonder, however, if the non locality is an artifact from our wrong or incomplete concept of the space-time. There is, after all, no such thing as non locality in the general relativity, which can't be quite right.
@@kostuek Could be both (you’re right about non locality not being apart of GR). Although you now have to ask the question on what’s more fundamental, General Relativity or Quantum Mechanics? Some people would argue Quantum mechanics, while others would argue General Relativity.
Many-world QM doesn't require nonlocality as far as I know? Weird enough that this is often not emphasized by MWI proponents (like Sean Carroll). My guess is that if one is inclined to believe that space is emergent from quantum entanglement, then nonlocality is not _that_ bothersome...
@@ngwoo The will is what counts. It harmonizes so nicely (with the topic in relation to the picture). Can we just agree that it was meant to be like that, defined by celestial deterministic cosmic events (or whatever term fits best for you)? ^-^
As someone who has a background in Physics, I always went along with the accepted point that the randomness within a quantum entangled system prevents FTL communications. I recently read a book 'Cracking the Cosmic Code' which actually shows that the randomness is not a restriction at all. It now opens up the distinct possibilities of FTL communications.
"What you hear is a expanding series of density waves" False, I hear my tinnitus which in no way can be heard by anyone else and only echos around in my head... Ouch, please help me.
Tinnitus is very real and not something made up by crazy people. Ear damage is irreversible, therefore anyone that develops tinnitus has a condition that will never improve. I suffer from severe tinnitus, and I'm willing to bet more than half of all people alive today suffer from tinnitus at some level. Airplanes, cars, trains, power tools, loud music... Almost everything we use today creates damaging levels of sound. The ringing you hear isn't an actual sound from outside, but the sound signals that are sent to your brain from your ear are very real and can cause real suffering.
@@roblaquiere8220 oh man, I didn't mean to say it wasn't real, just that it's not sound and no one else can hear it, so it's only "in my head". I really do suffer from it.
@@michaelblacktree Mine is possibly a gift from my Dad playing guitar in a band when I was younger. I literally don't remember a time in my life where my ears didn't ring.
@@megan_alnico Oh sorry, I see now the nuanced meaning of your original comment. I was simply pointing out that the hallucinated sounds of tinnitus "in your head" are directly caused by a physical disability. Therefore the hallucinated sounds are in a way real, causing real distress in the individual. As Michael pointed out, tinnitus can be acquired. Craziness however, is not communicable. Thus if your tinnitus ever starts instructing you to burn things, we have a serious issue!
For the first time I understood how waves travelling do not get scrambled, why it depends on the medium these waves travel through and why our spacetime is stretchy - as we detect gravitational waves from objects far away. Awesome
Both the many worlds interpretation and the particle-wave (de Broglie-Bohm) interpretations are attempts to “conciliate” QM with determinism, both have additional structures that have to follow certain “restrictions”, and both are based on using definitions of determinism that fail to reflect practical determinism (what should be the important concept for a scientific theory). Both “interpretations”, remain just “interpretations” of QM (do not change testable predictions) if the “restrictions” are followed, but can give rise to not “equivalent” theories (different testable predictions) if the “restrictions” are not followed. (For BM the “restriction” is the “quantum equilibrium” and for MW the “restriction” is that the different “words” do not interact). BM (electron example): if you know the configuration of an electron (its wave as well as its position and speed) BM determines the future evolution and measurement results for that electron, so BM is “deterministic”, true? The trick: you cannot know the wave and position of an electron (before the measurement to be predicted) without violating the “quantum equilibrium”, but if “quantum equilibrium” is violated, BM is not equivalent to QM, if you violate “quantum equilibrium” you have to say how exactly, or you do not have a testable model. So, BM in practice do not make deterministic predictions: it is in essence as non-deterministic as QM (the version without “quantum equilibrium” is not even a well-defined model and we cannot say what it is). MW: as all the possibilities happen, you have a deterministic theory. The trick here is of course that in practice what we want to predict is what will happen in “our” world and not in other completely “disconnected” worlds. Inventing things (words in this case) that are undetectable and not testable you can argue and “demonstrate” whatever you want (not just determinism), to resort to completely not testable words (or should I say ghosts) is a “dirty” trick that completely undermines the scientific method. But if the other words interact with our word, and have testable consequences in our word, then MW is not equivalent with QM and it is not even a well-defined model (we should say exactly how the worlds interact to have a testable model) and so we cannot say a thing. The video analyzes modifications to QM and their impact in the MW view, if the words interact, they could be tested, so just define with more detail how that interaction is and test it, I do not think these ideas have more chance than many other ideas (long story) but who knows? But the worst in all this story is that most of the scientific community associates determinism with “realism”, and the efforts to conciliate QM with determinism are view as efforts to have a “realist” interpretation of QM. But realism is to believe in the existence of things (objects and phenomena) outside (and with independence) of our MIND (or of any mind), so realism has NOTHING to do with determinism, realism has nothing to do with locality, realism has nothing to do with “hidden variables”. On the contrary, the fact that we HAD to create a theory that goes against what we believed the reality had to be, and the fact that the experimental data obligated us to create a theory that is so weird and anti-intuitive indicates that there should exist a reality outside our minds (otherwise, if not obligated by the facts, we could had never imagined something so weird and strange to our intuition). Lamentably, this “erroneous” way of thinking (associate determinism or locality with realism), is just a case of one of the most common errors in human thinking, and reflects the absolutism and the lack of humility of our way of thinking. The error is to try to “impose” how things have to be, and if facts show that things are not as we think they have to be, we say that those things are not “real”, instead of humbly admitting that we were wrong and reality is not as we thought it had to be. This reflects an incredible degree of arrogance and absolutism (and idiocy?): we cannot impose anything to the nature of real things (objects and phenomena), we can only impose rules and properties (to a limited degree) only to things inside our MIND (imaginary things). We are not gods, we do not have any “mythical” capacity of knowing how real things have to behave before thoroughly testing them, we just have the intuition adapted to our most immediate environment, but reality have proved to go much, much beyond our most immediately accessible domain of reality, and our intuitions do not have to work for other domains of reality (limited subsets of phenomena, objects and aspects of reality). Still worst, determinism/indeterminism are concepts that apply to the kind of predictions that can be done with a model, predictions are made by a MIND (where the model exist and is operated), so det./indet are concepts that do NOT apply to anything outside a MIND, that is, they do not apply to reality (what exist outside and with independence of any mind, remember?), that is, it has no meaning to say that reality is indeterminate (or determinate). This has some additional subtleties, but they do not change the essence and for today that’s enough, this is getting very long and surely this is not the place for all this. I very much appreciate the PBS Space Time series, and Matt’s efforts to “decode” deep concepts to the physics enthusiast community. I see as a very good and necessary thing to incentive the scientific/rational/critical thinking in our society. Even if not always completely agreeing with the concrete things said, agreeing or disagreeing is secondary, because understanding have “levels”, and there is no definitive or “ultimate level”, and it is more important to exercise the rational/critical thinking.
I've been thinking a lot about a non-linear wavefunction recently, it seems to make sense. After all, we thought light and optics were linear for a long time but it turns out there's non-linearity, you just need very high intensity or anisotropic media to see it. Its likely that something similar is true for general quantum systems. Also, perhaps this additonal term of the wavefunction describes a stochastical collapse timescale, and the probability depends upon the number of entangled particles. Any measurement induces entanglement of huge numbers of particles so it would be very likely to collapse, and match experiments. Unsure how you'd prove this though
I love when I'm following along and have a thought to myself and then it's exactly what you say next. I guess it was sort of obvious where you were going but right before you brought up Schrodinger I thought to myself "this theory must not be complete. We don't have a full understanding and thats limiting us"
We must continue learning to break down matter and put matter back together again, this is the whole point to Quantum , if we ever going to have teleportation And live forever , but I'm still having problems with the gravity suit !
I've never enjoyed a person's ability to speak so well with body language and voice as much as this dude lol every word seems just as mindblowing as the last.
Doing the same thing over and over again and expecting something different... is what we do when we practice something like our serve in tennis. The comment at the end about the bubble-like structure of galactic magnetic fields, their origin in supernovae, and our ability to measure them, is completely fascinating and should be the subject of at least one if not three future episodes. I've never understood how an equation describing a linear system (if that's what Schroedinger's equation does) can also describe a system which has interactions between particles. Aren't these interactions fundamentally non-linear? Sound waves do not propagate forever. They hit things and refract or reflect off. If Schroedinger's equation describes those interactions, then some part of it must be non-linear.
Interactions don't automatically mean nonlinearity. For example, if a bunch of electrons get close together, they'll interact with each other via their electric charges (i.e. repel each other) but their total effect on some other object, say, a proton, is still just the sum of the individual effects. Chemistry would be totally different if this wasn't the case.
Hi Matt, I love your show and I thought this was one of the best episodes ever. I must ask how would “you” and “other you” be able to tell each other apart to know who sends and who receives? Even if it were mutually decided ahead of time which spin direction would determine the sender, couldn’t there also be an “alternate you” and an “alternate other you” in the multiverse who mutually decided that the opposite spin direction would be the sender? In order to sort out such details it seems all sides would need to communicate with each other. Wouldn’t that be a causality-defying situation where, in order to successfully send a message across the multiverse, one would first need to… successfully send a message across the multiverse? Please keep the outstanding videos coming!
Thank you for yet again a scintillating lecture! I enjoy them thoroughly My understanding: I would go with the Copenhagen universe in which the wave function collapses at the time of observation Being a physicist and a follower of Indian Vedantic thought; which says that “ this world is lost to me in my sleep and a different world appears in dream” So when I am NOT there ( no observer)it ceases to exist And different realities exist for different people
I'm a big fan of the many worlds interpretation, and I'd be fascinated if it were true. I hope we get some scientific breakthroughs in quantum mechanics within my lifetime.
There is one breakthrough that explains the many worlds interpretation. Any interpretation that introduces paradoxes is 100% meaningles. And even assuming that it's true. No matter what experiments you run you will never be able to aprove the theory or disprove it. Meaning it's crap. You're welcome.
@@HakaiKaien That's not how it works. If it's true then it has practical uses which were described in the video. He literally said this in the video, sorry kiddo.
@@housetheunstoppablessed4846 Not my words, kiddo. And yes, that's how science works. If your theory cannot be proven or disproven, you literally have no practical use for it. And that is true for any theory that introduces paradoxes.
Just like the last video, I'm left wondering if there is some chance that the wave functions (or the sum of them) from other universes might interact gravitationally with ours in some way to explain the extra pull of Dark Matter. Maybe those other universes closer in phase to ours interact more strongly and as the other universe's phase becomes less aligned, the gravitational effect lessons. It seems to me this would create a diffuse halo of extra gravitationally interacting stuff right around all galaxies which kinda sounds like Dark Matter. Or maybe this is all easily disprovable by someone who has more knowledge on the subject than I do.
Interesting thought however wave functions interacting is disprovable. When we have a system of 1 particle where we know the necessary information about it to accurately predict it’s wave function, we are correct about its position or speed with probabilistic outcomes. If there was other universes interacting with said particle, then the results of a double slit experiment would not match our predictions, because there would be extra interference in the wave. So it’s either we aren’t interacting with any other universes, or the universes we interact with are all nearly perfectly static as to not change our test results and interfere with patterns. I don’t know anything about dark matter to prove nor disprove anything about it, however I personally believe axions and low energy neutrinos are a much more likely explanation for dark matter than other universes interacting with us
💯 2022 possibly God! WOW a being that most scientist can neither prove or disprove. FAITH, HOPE AND LOVE. The greatest is love. CAN SOMEBODY SUMMON JESUS PLEASE AND GET ME OUT OF HERE? Oh, that’s right nobody believes but me. Rely on the stars and math and let’s see what happens. SEE YA’ll SOON MAYBE!
@@nerdsunscripted624 If the only interaction between waves interacting is through gravity then how could that affect our experiments in any detectable way. As far as I know the gravity produced by masses as small as what is sent through double slit experiments has never been detected, nevermind interfere with the trajectory of the other particle possibilities.
After watching this, I came up with a fun “game” I like to call “quantum truth or dare”. It goes like this: First, pick a dare. The dare should be some sort of experiment, or something with a “success state” that you want to test. You then start the telephone, and begin the “coin flip” as it were. If you got heads, congrats! You get to know the “truth” about that experiment for free! If you get tails… well, you’re the unlucky bastard who has to carry out the “dare”. If your experiment succeeds, you send that message back to the “truth” world. The game relies on trust in your alternate selves, however, so make sure you pick a dare that you’ll actually commit to. If you REALLY don’t want to do the dare, however, you could always fiddle with the measurement direction/superposition to give heads a much higher probability than tails, but I don’t know enough about the theory to know if that would screw up the communication or not.
I enjoyed Dr. Asimov's essays more than I did his fiction, overall. While his speculations were rational and internally consistent, his character development tended to be weak.
@@jeffthompson9622 I corresponded with Asimov while he was alive. He was a very modest fellow, considering his achievements. He did make some astrophysics related mistakes when he wrote his last book, _Nemesis,_ which was published three years before he died. I told him about them; I probably shouldn't have.
@@Jenab7 He was prodigiously productive as an author, covering a vast variety of subjects, and strove to be scientifically accurate and plausible. Inaccuracies based on subsequent discoveries don't count and a rare error in Nemesis still leaves him ahead of almost everyone who has ever written science fiction.
I would have felt the same way under the circumstances. He strove for scientific accuracy and an inadvertent flaw in Nemesis still leaves him far greater integrity than almost anyone else who has written science fiction.
So one possibility is potential backwards time - travel, and the other seem to allow for hypercomputation if you have access to the entire wave function. Meaning you could construct a Quantum Computer that can do things a Turing machine can't do, such as the Halting problem 🥺
Yes and then add in pocket universes with way faster rates of causality(speed of light) to calculate in virtual computers and you get part of my far future computer ideas. Need way faster than causality computers to handle movement of everything faster than light in combat along with assumed new branches of math done by smarter than humans computers. Then I greatly reduce the computers abilities in combat by new dark energy jamming thus human crews still required to use one topic only computers that handle tiny parts of the whole controlling of the ships and do repairs as the robots are down. I use dark matter as a whole new periodic table and dark matter and matter combined molecules in order to do stuff like Uranium stable and other elements stable all the way into the 500's. Then magic and mind powers are powered by the huge variety of dark energy and dark matter mana and otter magic and ESP particle the Earth just currently in one of the few near voids of those sources in our universe which is why our ancestors believed in magic because It used to work. Unfortunately I starting to be come a alternative gravity or pilot wave theory person in real life.
Question regarding the mechanics of the theoretical quantum telephone: is each bit of information being communicated with a different multiverse - or is there a way to stay connected and slowly communicate bit by bit?
Wow, great ep.! Writing, comprehensibility, humor, graphics, and presentation were all on-point. And thanks for reminding me of the Quote Investigator site - looks like the true author of that "definition of insanity" quote will never be known, due to the nature of those Anonymous 12-step societies. I enjoyed this 1895 precursor to the quote, though, and the opening phrase that weirdly ties in with the subject of this episode(!): "Has anyone anywhere in the poetry of the two worlds ever seen such complete idiocy? These ‘Ahs’ and ‘Ohs,’ this want of comprehension of the simplest remarks, this repetition four or five times of the same imbecile expressions, gives the truest conceivable clinical picture of incurable cretinism." _-Degeneration_ by Max Nordau, 1892, English translation 1895
THIS WAS AN AMAZING EPISODE. WELL DONE. I’d like to believe I’m a sharp 23 year old, and I think its important for people to be aware that the concepts covered were brilliantly conveyed. Most people on earth should be watching this, because having an understanding of how the universe you actually live in works and the most up-to-date physics is incredibly important, especially when the medium is unbiased, accurate, and honest. I emplore you to maintain all of your passion, you’re doing the world a very ideologically meaningful and inspiring service.
For the Superposition Theory to apply, a system must be Linear AND Time Invariant. So, Linearity is required but not sufficient. For Superposition Theory to apply the system must also be Time Invariant (the system function of the medium does not change with time). That is a really hard constraint to meet even for RF because the behavior of the medium often changes with time. Because of that, so we often accept that it is "invariant enough" if it changes slowly with no discontinuities. The collapse of the Wave Function sounds like a whopping discontinuity. Note: Your comment really popped out to me because I just taught a course on Modern Communications Systems in the Spring and LTI & superposition are core to Communications Theory.
As always amazing video! Could the multiverse telephone be used to effectively double the ammount of available CPU cores in a scifi computer, by having the same computer cores compute different things depending on wich part of the multiverse they are in and then sending each other the results?
@@slickytail Exactly! I just stopped at 2 to illustrate the concept in it's most simple form. Appart from engineering limitations that would surely come up the only limit would be, that transmitting all results to all timelines would at some point cancel out the benefits of another split.
@@invalidstring3447 Man, that sounds kinda like a "regular" quantum computer. Calculating all possible answers simultaneously and then all the wrong ones cansels out, leaving only the right one.
@@simonisaksson3570 You are right, but in the multiverse case the fancy new chip is only the transmitter, while the computation can happen on regular hardware. In a quantum computer you have to redesign your whole arithmatic unit.
The irony of trying to find one interpretation of the Schrodinger equation... maybe it's all interpretations at once!! forever hidden behind the veil of uncertainty and probability :P
Okay, so this episode inspired a few questions that are tangentially related; 1. Should we assume that the fabric of spacetime is a homogenous medium in which the wave function always travels consistently? Could something like "The Great Attractor" cause spacetime to be a different "tautness" in some way that varies from general spacetime in relation to wave functions? 2. If humans can position LIGO devices within the local solar system-- would this be enough to measure any sort of decay in the propagation of gravitational waves? Should we expect spacetime to resist these waves in some fashion towards the preferred equilibrium state? Is it possible that some of the gravitational waves detected by LIGO actually came from another universe? 3. Could a large enough cataclysm in the "Pond Next Door" cause any sort of disturbance in our pond? ie, the universe where physics caused a Big Collapse? Someone throwing a big rock in an already "Ripply" pond?
You know what thought ive had recently: Since there's particles with definite mass but indefinite position, are there particles with a definite position but indefinite mass?
Doing the same thing repeatedly and expecting different results when you're receiving the same results is insanity. Doing the same thing repeatedly and not second-guessing what's going to happen is science.
Faster-Than-Light Communication had been on my mind lately so this was a welcomed addition to it. In the Warp-Drive episodes there are a lot of unsolved issues to faster-than-light travel. Since energy requirements for the drive are so large, I'm wondering if those theories would better fit FTL Communication since the warp bubble would potentially be much smaller? That is ... if problems currently arising from warp theory could be solved for smaller warp bubbles. These are two different forms of hypothetical FTL Communications: Tiny Warp Drives and Non-Linear Quantum Entanglement. I'm curious to know if either are detectable at far distances? Let's say Alien World 1 set up a FTL Communication to Alien World 2. Would constant use of a system (either one) eventually lead to observable effects from other distant civilizations such as Earth. Could we see obvious signs of Warp Drive communication "wires" between stars? Could we somehow observe hundreds/thousands/millions of entangled particles being used between two stars (if the use of more than 1 entangled particle would lead to detectable effects)? Would either of these FTL Communications be useful in attempting to contact a civilization unaware of the sender? Could either warp-driven particles or a barrage of quantum entangled particles be hitting Earth harmlessly, but we're not aware on how to look for it? I always associate SETI with radio wave detection, but often wonder if we're meant to look elsewhere. And a lot of what's hypothesized on this channel makes me ask: "If aliens figured this out and constantly use it over and over, would that create any sort of effect we could see?" Changes in atmosphere, light signal, waves, etc etc ...
Entanglement is point to point- the data is teleported from A to B with nothing traveling in between. Think of a video game world where somebody suddenly tweaks the color palette for a game object. There's no "signal" within the game's space or time triggering it; it's coming from 'outside' in the sense of the underlying code that generates that emergent environment. Tiny wormholes are similar. Ones big enough to send objects through should emit some radiation like gravity waves, so they are detectable in principle. Warp drives could also generate gravity waves as they are effectively a way of manipulating gravity to beat the light speed limit. They may also emit a short, intense pulse of radiation when a ship stops (think narrow gamma ray laser). The problem is we'd need to be really (up)lucky for such a pulse to be both aligned with one of our detection telescopes and close enough to stand out from background noise, and both are really unlikely from light years away. The upshot is that OUR entire civilization is far from being obviously detectable from nearby stars, and unless somebody close by makes a major effort to get our attention we won't see them either.
I have an idea for a "science based sci-fi" story thing. Imagine the internet as is, but with a few more higher "backbones". like Earth's would be more or less how it is, but to communicate with the Martian one, both sets of internets communicate via some kind of higher "entanglement" system. Being the homeworld, Earth would have a higher communication array that, say, entangles with all the other systems in a 400 light year distance, AND connects to an even higher one that deals with connecting 5000 ly ones. To establish a new connection, you basically need to connect the two at a location, leave/fly one to where it goes and same with the other. Now the fun! Ships can use simple laser arrays to entangle to nearby ships (good for military ops), and/or use the nano-wormholes appearing/disappearing in the quantum foam as a kind of ftl loud speaker. Statistically, the closer to a source you are, the more of the signal you'd get. This is the primary SOS system for the space ships. As for FTL propulsion, said nano-wormholes can be enlarged by using a specially made gravity plate array (not getting into those here) to basically inflate the space the wormhole is in to macroscopic scales. A little pseudo-science for plot stuff, and the ships effectively "leave the universe" while traveling from A to B in a wormhole. No trace of the path as wormholes leave no trace IRL. We can't trace wormholes, and if warp drive is a thing, our detectors aren't good enough to pick it up.
Let's say faster than light communication is possible at an arbitrary speed > c and humans can do it. Let's say there is a spaceship passing by Earth at about 0.99986c (so when a second passes in one frame of reference it sees a minute has passed in the other) Let's say from the ship's perspective, it sends a message that will be received at Earth just as it passes by and set the moment the ship sends the message t = t' = 0. (t = Earth's time and t' = ship's time) (1 light minute = 60 seconds * c) Let's say the closest the ship gets to the Earth is 80 light minutes. And when it sends the message, it is 100 light minutes away from Earth. A right triangle can be formed here with its hypotenuse 100 light minutes and opposite 80 light minutes. The adjacent will therefore be 60 light minutes. It will take a little bit more than 1 hour for the ship to travel 60 light minutes. (in the reference frame of the Earth) On the ship, however, only 1 minute will have passed because of length contraction. (also in the reference frame of the Earth) For the message to travel 100 light minutes in 60 minutes, it will have to go at 5/3 c. So, at the moment the message is received at Earth, t = 60 minutes and t' = 1 minute Let's say people at Earth decide to reply and send a message just as they get the message. The ship will receive the message at t = 120 minutes and t' = 2 minutes. From the reference frame of the ship, it is the Earth that is slower. It will take 2 minutes for it to get the reply but it will see the people at Earth have only experienced 2 seconds. It can now "forward" the reply back to Earth when it is away 100/60 light minutes. (length contraction) Since they can communicate with 5/3 c speed, it will take (100/60)/(5/3) = 1 minute for the forwarded message to reach Earth. So, from the ship's perspective, the Earth will receive the forwarded message at t = 2 seconds + 1 minute = 62 seconds The Earth has just received the message at t = 62 seconds that it sent at t = 60 minutes which means it received the message before it even sent it! So, if we could communicate faster than light, we could send messages to the past. However, this would violate causality. Therefore, faster than light communication must be impossible.
I loved that unix fortunes program! It provided a seemingly endless supply of witty one liners to post as social media status updates, as well as plenty of other jokes retold for the X,000,000th time... ;-)
Interaction terms in Quantum Field Theory break the superposition principle, because wavefunctions do in fact interact with each other (e.g. electrons emitting photons - the electron wavefunction influencing the photon wavefunction). EDIT: See discussion below, I was wrong, the equation of motion in QFT is also linear and so superposition holds.
That’s not my impression (though I don’t really understand QFT). There is a thing called algebraic quantum field theory / AQFT, aka local quantum field theory, which describes, uh, iirc a sheaf (over the spacetime manifold) of algebras of observables, and, uh, it has Lorentz transformations (and I think probably also more generally poincare transformations) map to unitary maps or algebra elements or something, and, so, I think it also satisfies linearity of time evolution. If it isn’t me who is confused instead of you (and it is quite possible that I’m the one who is confused!), I think the confusion likely comes from the nature of tensor products. If you have a tensor product of two vector spaces, given any bilinear map from the two vector spaces, there is a corresponding linear map from the tensor product of the two vector spaces, which in a sense is an extension of the bilinear map. When you make a system out of two systems which each have one particle (of different types, let’s say), to get one with two different particles, you do this using a tensor product. In this way, you can have stuff that, if the two systems are not entangled but just two independent systems, is like a product of a linear function on one multiplied by a linear function of the other, but because this is bilinear, we can extend this to the whole tensor product, and the result is a linear function. I believe the same kind of thing applied when instead of two systems each with a different single particle, we have two fields of variable numbers of particles. Like, if you have the state space for a single particle of one type, and another state space of a single particle of another type, If you wanted a state space for “either one of the one type, or one of the other type (or a superposition of these”, you would take the direct sum. For either of them individually, if you took the Fock space for the space of configurations for the space of the one particle of the given type, that would be the space of configurations for a variable number of particles of that type. While, if you took the Fock space of (the direct sum of the space for a single particle of the one type, with the space for a single particle of the other type) You would get the direct product of the Fock spaces of the two separately. (Just like how exponentiation turns a sum into a product, the “the Fock space of” turns a direct sum of spaces into a direct product (I.e. tensor product) of spaces. In symbols: F( A \oplus B) is isomorphic to F(A) \otimes F(B) . So, I think this is how this could seem to be nonlinear at first glance, while at a closer inspection turns out to be linear.
Thanks for your detailed response. I think what is important to determine, is what we mean by "superposition" or "linear". If we just take superposition to mean the wavefunction can be a linear combination of eigenwavefunctions (corresponding to specific observables), then yes QFT allows for superposition. However, unlike the Schrodinger equation of QM which actually is linear in the wavefunction, a linear combination of QFT field solutions does not necessarily solve the same QFT equations of motion. You can imagine this like this: wavefunction 1 is an electron moving right, wavefunction 2 is an electron moving left, but wavefunction 1 + wavefunction 2 is not a valid solution as it describes two electrons moving past each other without affecting each other. This is what I was meaning to say when I said QFT breaks superposition -- it breaks the condition "any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state" (see quantum superposition wiki page).
Sorry, a quick clarification. The difference seems to be whether you consider a wavefunction as psi(x) or psi(x, t). You can always sum up any number of wavefunctions that are a function of just space (which corresponds to considering some arbitrary configuration of the universe), but if the wavefunctions are full solutions to the equations of motion (i.e. a function of time) then you cannot sum arbitrary time-dependent solutions.
@@project.eutopia Oh! Just saw your follow up message. Ok, that seems an important difference / seems like it should help resolve my confusion, thanks Edit: wait, no, that still doesn’t seem to quite resolve my confusion, because my expectation is that the time evolution operator should be linear. Unfortunately I should sleep soon. I hope to read up on this soon, and I thank you for your comments.
@@drdca8263 Hope you are doing well! Perhaps the following helps clarify what I mean a bit more. While the equation of motion in QM (Schrodinger equation) is linear (it is a linear polynomial in the wavefunction and its derivatives), the equations of motion in QFT are non-linear (and this is due to the interactions amongst the fields). For example take a look at the wikipedia page "Quantum_electrodynamics#Equations_of_motion" (can't type full links here). Both the blue boxed equation of motion for the electron (psi) and photon (A) are non-linear (electron equation has a term like psi*A, and the photon equation has a term like psi^2). This is why linear combinations of time-dependent solutions are in general not also solutions to the QFT equations of motion.
I'm glad the "doing the same thing" quote is not from Einstein. It seems there are a lot of mental health problems that have nothing to do with repeated actions or expectations. Wouldn't it be more accurate to say “The definition of quantum physics is doing the same thing over and over again, but expecting different results.” After all, half the time you get spin up and half the time spin down and you never know which one to expect before you start the experiment.
6:53 No, it is possible, by definition. Wave function is defined in a space of every possible particle position. Five photons require 3*5=15 dimensions. In essence, every coordinate tuple of wave function is a static universe, and static universes come into motion due to interaction with neighbor universes. Wave function defines measure of existence of each static universe as a square of magnitude and relative phases encode the movement. Particles in old position become much less probable and particles in new position become more probable. So we already interact with neighbor universes. The problem is that we interact with universes not different from ours that much. Quantum Mechanics is only non-local if you project coordinate of every particle into the same physical coordinates. If you do not project coordinates and let wave function stay as is, an extremely high-dimensional entity, Quantum Mechanics is local. Hamiltonian is local. Linearity of equations does not forbid building a tube into another world that became notably different to ours. More about possibility by definition. You assume that there is a superposition of "us who tried to call another universe and heard nothing" with "universe that we did not ever call". Well, if you combine them, indeed, nothing changes just because they are nearby. But it does not mean that there cannot exist a universe that we have made a successful call. There are lots of universes drifting apart from us which we were never in superposition with and will never be, so we could possibly restore communication.
Now it's already a marvelous thing that the different quantum fields have excitations (waves) that interact with each other to form "solid" structures that "stay" in place... Can you imagine how the world look if we see all these waves in their true form??
This video was how i found out Steven Weinberg had died. There were never many like him, and there won't be many more. With all the brevity of life, there aren't many worth taking a look in the rearview mirror over, but he is one of them. He was more than a scientist.
Ted Chiang has a great short story about this very possibility. "Anxiety is the Dizziness of Freedom" The story can be found in his collection "Exhalation"
@Gandalf many worlds is deterministic (because a measurement doesn't cause a collapse to a random outcome). Scientists don't "hate" the pilot wave interpretation, afaik.
@@taxicabnumber1729 Yes, that is true but many worlds solves the consciousness problem by making it possible because each "world" or thread isn't on its own/locally deterministic. A not many worlds interpretation must be non-deterministic for consciousnesses to arise.
I don't know if physicists hate it but it gets backlash because it is impossible to reconcile special relativity with pilot wave. Special relativity proves there is not 1 universal clock and that certain events happen at different times for certain observers but in order for Pilot wave's "hidden variables" to work it depends on there being 1 universal clock that every particle in the universe is running on. With hidden variables the position of every particle in existence is affecting the path a particle takes. But you can't claim that the position of every particle in existence is causing a particle to take a certain path, when the positions of every particle are also relative due to the relativity of simultaneity. Thus hidden variables is a lost cause and so is pilot wave.
@@gandalf8216 why must it be non deterministic for consciousness to arise? Nothing about consciousness requires non determinsinm. I know the idea that our brains and our thoughts might be deterministic upsets some people (it's OK though, they can't help,it ;) ) but we shouldn't base science on those sorts of feelings.
So if you do the double slit experiment with lots of photons, in all alternate universes all observers see a similar pattern, so has the universe actually split at all? Or are they still sufficiently 'correlated'? Could closely related multiverses influence eachother so they end up 'merging'? (The notepad where you wrote the result gets eaten by a dog)
How ironic that the presence of nonlinearities is what would allow us to test an interpretation when it's usually easier to test models with linear equations.
perhaps things like dreams, visions, and deja vu happen when enough particles of our brain that are entangled across the multiverse connect and share 'memories' and/or 'experiences'.
I know you want to be the best science educator you can be, but I've heard there's a much better version of you just two universes over. No pressure.
But, the one in between, eek!
Only two universes over? Does he have an extra hair in his epic beard or something?
@@Robert_McGarry_Poems You put together a few million test chambers and see how you look. Chariots chariots.
It's the Fat Mat from the beginning
Two over, but in which direction?
For everyone who's curious: The morse code at 9:10 translates to "space time rocks" and "pineapple on pizza is wrong"
Thank you! i was wondering if someone actually knew this.
In fact, the Morse says 'skcor emit ecaps' etc.. just saying. They didn't think it through. Old UK duffer here, enjoying the ride :)
Curious who is a pineapple 🍍 on pizza 🍕
Straight facts.
WELL DONE! I was watching Matt and totally missed it! I guess a few of us still know Morse!
How to communicate across the Quantum Multiverse
Step 1: Measure charge of electrons emitted from a Stern Gerlach device.
Step 2: ???
Step 3: Profit.
Or, more precisely:
1) measure spin
2) depending on spin, either do nothing, or choose whether to negate the spin based on the message you want to send
3) ???
4) measure the spin again, and compare to your initial measurement
5) profit
Thank you......
Damn, this whole time I've been using a Gern Sterlach device! I was so close . . .
@@drdca8263 oh so like:
1) measure the spin of an electron
2) depending on the spin, either bounce the electron back through the polarizer or just like, let it do it's own thing, be free little electron!
3) do this with a ton ton ton of electron
4) Well doing this, measure the spin of the electrons and compare them to your initial measurement
5) award the nobel prize money to drdca, hydrowolfy, and whichever Dr Weisenberg who built the other side of the device since he had this idea before either of us and would probably have done exactly this idea.
I suppose the only question I'd have is, which one of the single world liners is gonna pony up the prize money. That's how Nobel prizes work right?
@@hydrowolfy I was just saying the same thing as OP’s joke but with more detail from the video included? No extra detail which was not in the video (except if I remembered part of it wrong and included such an error in what I said)
I was just being pointlessly pedantic about a good joke.
this really reminds me of the short story "Anxiety is the dizziness of freedom" by Ted Chiang. In this story people were able to communicate with a parallel universe by a similar machine as described here. they could then send and receive a limited number of information of their parallel self. by this they could see how other versions of themselves reacted to specific events and eventually how their lives changed based on that decision. Good read, I really recommend it to anyone who enjoys more "grounded" scifi stories
I thought the same exact thing watching this!!
@@Maxmaxmax63 Same.
Hey , thanks for this! I'll be sure to check it out.
Great title. Like, poetically good.
Man, imagine the reaction of the guy that sees the results from that test. Knowing that somewhere, somehow, a darn near 100% identical version of yourself is experiencing the exact same feeling, the feeling of knowing that you exist and have just communicated with them. That may very well be the most world shattering discovery to ever be made, if not just knowing that there are other worlds, then by the sheer implications of what's now likely possible within our own world.
They might as well go insane because nobody believes them though...
@@osdever The results of the experiment would be replicable by other researchers
The nice things is that we could each have a simple computer (the same actually), each do some computation, and then share the results.
@@karsonio3543 this is my deepest hope for any future discoveries. It will mean superpowers, horrors beyond our wildest imaginations, unbelievable fantasies will come true, and more. So much more…
And it’s only the beginning
Perfect timing, I was just wondering how to do this.
😂👍
😂😂😂😂
You even didnt complete the video 😂
legit I was really was xD I am studying quantum computers
It's perfect timing for me as well because I'm reading The Hidden Reality by Brian Greene.
13:30
This universe just became one bright light dimmer.
R.I.P.
Consider that by whatever cascading contrivances of a differing quantum event, there's a whole set of realities where he's still alive, and within them he's wholly unaware of the realities where we are now mourning him.
If the "many worlds" interpretation is correct, that is.
As usual... my other self must have left their quantum phone in the car because there's no answer :-(
Seems like the other Bruce is a bit careless. 😬
least other you didnt butt dial ya
Hey at least the other you is considered.
Could be worse. I remember when an alternate me drunk-dialed me. THAT was a conversation I never wanted to have.
I wouldn't want a many-worlds phone because the worse versions of me wouldn't want to be depressed, and the better versions of me wouldn't want to be disturbed.
That cat walking at 3:39 is awesome. Needs to be in more episodes. 👍
MAIQ AGREES WHOLEHEARTEDLY, TRAVELER!
Non-linear effects: making physics more exciting one field at a time.
check out Superoscillations: imaging beyond the limits of diffraction
mind blowing
It's math and logic. And it always leads to multiple universes, nothing else. Even if this universe were cyclical, there would still be an infinity of others concurrent with this one
"The definition of insanity is doing the same thing over and over again, expecting different results." Of course, Einstein would not have said that because that is not the correct definition of "insanity". It is, however, a valid description of "practice".
No. That's the definition of Newtonian physics. Expecting different results everytime but in its probability is the definition of quantum physics. Probably something like that?
@@tTtt-ho3tq but newtonian physics is deterministic, so it wouldn't make sense to expect different result from the same experiment. in fact you would expect the same result each time. but if you practice, you feel like you're doing the same thing but you're actually getting better at it
@@CMDRunematti But if you're getting better at it, then you're not doing it the same way.
'"The definition of insanity is doing the same thing over and over again, expecting different results."'
No, we actually do that thing, since we need to find the statistical properties of the ensemble of a random process, and each observation is a different realization of the ensemble.
Shut up, Vaas lives in a liner world with a collapsing wave function.
Also, don't use quotation marks for "emphasis"
Therapist: Slavic Matt doesn't exist, he can't hurt you
Slavic Matt: Learn da secret truff off da universss
blyat
i thought it was supposed to be scottish lol
Zizek matt
He was both Scottish and Slavic simultaneously, the answer is unknowable until measurement collapses the quantum waveform
Lol who are you?
After this episode, I now firmly believe that Berenstain Bears is a cryptic message from an alternative universe.
That has been debunked multiple times
@@حَسن-م3ه9ظ he's joking
There is no way to debunk the Mandella effect. It's nonfalsifiable.
@@damonedwards1544 yes it is, all claims made about it turned out to be fake
@@حَسن-م3ه9ظ not true. To the extent that I know of it. Penquinz0 did a great video on it. There is legitimate proof that there is altercations made to the name.
I love the cat, strolling along the peak of the wave. That was clearly an alternative universe where cats walk upright and humans walk on fours.
I believe it’s Schrödinger’s cat!
I had no idea Steven Weinberg passed away just 3 weeks ago until I saw 1933-2021 in this video!!! So sad, I got to meet the guy in a guest lecture once, physics has lost a giant!
The stand-in dude for "You" and "Other You" who appears around 10:47... seeing them pop up occasionally in your videos is just such a delightful highlight for me. They're so wonderfully goofy and the various expressions we sometimes see on their face just adds a welcomed silliness. Do they have a name, I wonder?
That guy makes me chuckle every time.
I, too, would like to know his name
We need BACKSTORY!!
O wow pbs spacetime lore
It would be interesting to learn about some interpretations that aren't so famous as those mentioned in this episode.
Remember what Matt said about falling in rabbit holes!
Anyway, have you ever heard of Superdeterminism?
ruclips.net/video/cbSc-PLGU8o/видео.html
Especially Pilot wave - Bohmian mechanics in a depth
Then the video would be too long, however, covering just those interpretations does sound like a good topic for a future episode doesn't it.
@@rohanshah7960 I personaly like the pilot wave theory, in part because it does not require any "conscious observer" malarky
The short story "Anxiety is The Dizziness of Freedom" by Ted Chain explores this concept in a philosophical way and I LOVED it. I recommend it to everyone here!
No room for philosophies. Sorries.
@@widg3tswidgets416 all of this is philosophy anyway
@@pavlenikacevic4976 how is this philosophy?
We want true facts
The story is every bit as real and scientific as it is philosophical in my opinion. And it's such an original view that it was exactly what I thought of when I saw this thumbnail.
For some reason, 'Banana Phone' is now stuck in my head, and this is the reason why the better and happier version of me will never try to call.
@@goasthmago6354 I can't tell if that was sweet and uplifting or immeasurably sad, but I'll choose to think of it as a happy thing. :)
Clicking on a PBS Space-time episode is like going on a trip! I'm not always keen on leaving my comfort zone but when I do, I always have a good time!! And space!!!
"The trouble with quotes on the internet is that you can never know if they are genuine."
- Abraham Lincoln
"Don't believe everything you read on the Internet." - Genghis Khan, 1994
"Genghis is Irrational and should not comment on Internet" - Pythagoras, 2005 A.D.
"Pythagoras talked about x^2+2xy+y^2 things. The real story, though, is part of our infinite, and sometimes quadratic... spacetime."
-- Matt Dowd, 494 BCE
"let me Google this to make sure"
-Napoleon Bonaparte
"I never said half the crap people said I did" - Albert Einstein
Hugh Everett and his family has the most tragic story, truly heart-breaking. A troubled genius.. His son is the front man of a band called "eels". If you haven't heard them, give them a listen.
I never knew they were related. Makes me appreciate both the band and the scientist even more.
TIL the singer of one of my favorite songs is the son of the man who invented my favorite quantum mechanics interpretation
Good, now I can try my luck with my crush from an alternate universe. Oh, nevermind, she said she's dating my other self. Lucky bastard!
Edit: much love from Brazil!
Reminds me of that Futurama episode, the "other" Fry was dating Leela but not "this" Fry.
Don't give up yet. There's lots more universes where that came from. Pretty sure your odds are better than one in a Brazilian.
@@CAPSLOCKPUNDIT That's a damn solid pun, 8 out of 10 easily.
Abracos, from Brasil!
VOCÊ AQUI, PESSOA AMADA?
The Red Alert reference at the beginning is amazing.
exacto!
I'm writing a science fiction story that involves using such a non-linearity device to peer into other worlds when a baddie makes contact with the heroes who have to prevent an invasion. They ultimately do so by transmitting information to a distant world line before its event of no return transpires. Got the idea from a dream which was probably influenced by the novel Timeline by Michael Crichton and from PBS Spacetime which I've been watching for over 6 years, and you continue to give me ideas
So, there are three different “flavors” of quantum mechanics according to the nature of the Schrödinger equation: A boring linear one, a non-linear spooky communication at-a-distance one, and another non-linear one where you can phone individual bits across the multiverse. If only 1 is correct, then it seems that a theory of quantum gravity might be able to explain which version is compatible with our universe. How does this affect different candidates for a theory of quantum gravity? Is there any candidate only compatible with one version? Can such a theory, if confirmed, rule out the incorrect two? Or can any theory of quantum gravity be made compatible with any version of the Schrödinger equation?
I like this question! I don’t have any answers for you.
I think I’ve heard people talking about quantum gravity maybe requiring some nonlinearity (though I’m pretty sure there’s no consensus that it does, and my guess is that the majority view is that it doesn’t require it, but my impression is that the idea that it might is seriously considered?)
I agree, Many Worlds is absurd.
Maybe not the right place to air this out but I hate when people say spooky action at a distance...a much better translation of the German Einstein used is uncanny rather than spooky, very big change in the connotations
@@sagetmaster4 what did he say originally in german ?
@@eatabanana2258 thank you. I am german myself and I would say that spooky is an ok translation tho.
Matt: What do you hear? My voice, obviously.
Me: * laughs in captions without audio *
Let us take this opportunity to acknowledge and appreciate the folks who make sure the Closed Captioning (for the hearing impaired) on this channel is SPOT ON. Names, terms, physic-speak, ALL properly captioned. 🤟🤟🤟
@@fenwickrysen yes, but not only the hearing impared. Some of us don't have a headset at the moment, are in public and are too polite to make everyone else listen against their will
@@fenwickrysen the people who do closed captions should be paid so much more than what they are. They are the reason I'm able to follow these lectures
Just the title of this video is EXCITING
Steven Weinberg was a giant among a generation of giants in physics, his contribution to science cannot be overstated.
Thanks for playing a bit! Helps us calm down and just listen.
Non locality is one of the weirdest aspects of quantum mechanics. During my undergrad physics curriculum, I took a course titled “philosophy of physics” that touched on all the different interpretations, and Philosophical aspect’s of QM. Non locality was one of those aspects. The idea that if you have a two particle system separated light years apart from each other, and the state of one of those particles is already pre determined when a measurement is performed is mind boggling.
It is indeed. I wonder, however, if the non locality is an artifact from our wrong or incomplete concept of the space-time. There is, after all, no such thing as non locality in the general relativity, which can't be quite right.
@@kostuek Could be both (you’re right about non locality not being apart of GR). Although you now have to ask the question on what’s more fundamental, General Relativity or Quantum Mechanics? Some people would argue Quantum mechanics, while others would argue General Relativity.
Many-world QM doesn't require nonlocality as far as I know? Weird enough that this is often not emphasized by MWI proponents (like Sean Carroll). My guess is that if one is inclined to believe that space is emergent from quantum entanglement, then nonlocality is not _that_ bothersome...
Can’t wait for the iPhone 25 with entangled G10 technology
Can’t wait for the time when people stop giving money to apple....maybe start it now!
We've had that for decades... Here
With the ability to literally phone and groupchat with yourselves 🥺
Ugh apple is trash... With the looming mega disasters that are forecasted, phones and tech wont be much use
How do you know it will be iphone 25
I / We appreciate the fact, you selected the "Red Phone" from Control [videogame] in the thumbnail!
Wise / Understandable decision.
The one from the game has no dial plate, they're different phones.
@@ngwoo The will is what counts. It harmonizes so nicely (with the topic in relation to the picture). Can we just agree that it was meant to be like that, defined by celestial deterministic cosmic events (or whatever term fits best for you)? ^-^
That opening startled me so much.
As someone who has a background in Physics, I always went along with the accepted point that the randomness within a quantum entangled system prevents FTL communications. I recently read a book 'Cracking the Cosmic Code' which actually shows that the randomness is not a restriction at all. It now opens up the distinct possibilities of FTL communications.
Why are you lying about yourself? ;-)
"What you hear is a expanding series of density waves"
False, I hear my tinnitus which in no way can be heard by anyone else and only echos around in my head... Ouch, please help me.
Tinnitus is very real and not something made up by crazy people. Ear damage is irreversible, therefore anyone that develops tinnitus has a condition that will never improve. I suffer from severe tinnitus, and I'm willing to bet more than half of all people alive today suffer from tinnitus at some level.
Airplanes, cars, trains, power tools, loud music... Almost everything we use today creates damaging levels of sound. The ringing you hear isn't an actual sound from outside, but the sound signals that are sent to your brain from your ear are very real and can cause real suffering.
@@roblaquiere8220 oh man, I didn't mean to say it wasn't real, just that it's not sound and no one else can hear it, so it's only "in my head".
I really do suffer from it.
I was going to make a snarky tinnitus comment too. But Megan beat me to it.
BTW, I also have tinnitus. It was a gift from the US Army. YAY! 😛
@@michaelblacktree Mine is possibly a gift from my Dad playing guitar in a band when I was younger. I literally don't remember a time in my life where my ears didn't ring.
@@megan_alnico Oh sorry, I see now the nuanced meaning of your original comment.
I was simply pointing out that the hallucinated sounds of tinnitus "in your head" are directly caused by a physical disability. Therefore the hallucinated sounds are in a way real, causing real distress in the individual.
As Michael pointed out, tinnitus can be acquired. Craziness however, is not communicable. Thus if your tinnitus ever starts instructing you to burn things, we have a serious issue!
Remember it's a game !
Like checker's, he who moves first keeps winning. You're a Chip off the old Victor,very good job
Thanks for another great video.
As always, I understand nothing but I'm still entertained. One day, something is bound to click.
For the first time I understood how waves travelling do not get scrambled, why it depends on the medium these waves travel through and why our spacetime is stretchy - as we detect gravitational waves from objects far away. Awesome
Both the many worlds interpretation and the particle-wave (de Broglie-Bohm) interpretations are attempts to “conciliate” QM with determinism, both have additional structures that have to follow certain “restrictions”, and both are based on using definitions of determinism that fail to reflect practical determinism (what should be the important concept for a scientific theory). Both “interpretations”, remain just “interpretations” of QM (do not change testable predictions) if the “restrictions” are followed, but can give rise to not “equivalent” theories (different testable predictions) if the “restrictions” are not followed. (For BM the “restriction” is the “quantum equilibrium” and for MW the “restriction” is that the different “words” do not interact).
BM (electron example): if you know the configuration of an electron (its wave as well as its position and speed) BM determines the future evolution and measurement results for that electron, so BM is “deterministic”, true? The trick: you cannot know the wave and position of an electron (before the measurement to be predicted) without violating the “quantum equilibrium”, but if “quantum equilibrium” is violated, BM is not equivalent to QM, if you violate “quantum equilibrium” you have to say how exactly, or you do not have a testable model. So, BM in practice do not make deterministic predictions: it is in essence as non-deterministic as QM (the version without “quantum equilibrium” is not even a well-defined model and we cannot say what it is).
MW: as all the possibilities happen, you have a deterministic theory. The trick here is of course that in practice what we want to predict is what will happen in “our” world and not in other completely “disconnected” worlds. Inventing things (words in this case) that are undetectable and not testable you can argue and “demonstrate” whatever you want (not just determinism), to resort to completely not testable words (or should I say ghosts) is a “dirty” trick that completely undermines the scientific method. But if the other words interact with our word, and have testable consequences in our word, then MW is not equivalent with QM and it is not even a well-defined model (we should say exactly how the worlds interact to have a testable model) and so we cannot say a thing. The video analyzes modifications to QM and their impact in the MW view, if the words interact, they could be tested, so just define with more detail how that interaction is and test it, I do not think these ideas have more chance than many other ideas (long story) but who knows?
But the worst in all this story is that most of the scientific community associates determinism with “realism”, and the efforts to conciliate QM with determinism are view as efforts to have a “realist” interpretation of QM. But realism is to believe in the existence of things (objects and phenomena) outside (and with independence) of our MIND (or of any mind), so realism has NOTHING to do with determinism, realism has nothing to do with locality, realism has nothing to do with “hidden variables”. On the contrary, the fact that we HAD to create a theory that goes against what we believed the reality had to be, and the fact that the experimental data obligated us to create a theory that is so weird and anti-intuitive indicates that there should exist a reality outside our minds (otherwise, if not obligated by the facts, we could had never imagined something so weird and strange to our intuition). Lamentably, this “erroneous” way of thinking (associate determinism or locality with realism), is just a case of one of the most common errors in human thinking, and reflects the absolutism and the lack of humility of our way of thinking. The error is to try to “impose” how things have to be, and if facts show that things are not as we think they have to be, we say that those things are not “real”, instead of humbly admitting that we were wrong and reality is not as we thought it had to be. This reflects an incredible degree of arrogance and absolutism (and idiocy?): we cannot impose anything to the nature of real things (objects and phenomena), we can only impose rules and properties (to a limited degree) only to things inside our MIND (imaginary things). We are not gods, we do not have any “mythical” capacity of knowing how real things have to behave before thoroughly testing them, we just have the intuition adapted to our most immediate environment, but reality have proved to go much, much beyond our most immediately accessible domain of reality, and our intuitions do not have to work for other domains of reality (limited subsets of phenomena, objects and aspects of reality).
Still worst, determinism/indeterminism are concepts that apply to the kind of predictions that can be done with a model, predictions are made by a MIND (where the model exist and is operated), so det./indet are concepts that do NOT apply to anything outside a MIND, that is, they do not apply to reality (what exist outside and with independence of any mind, remember?), that is, it has no meaning to say that reality is indeterminate (or determinate). This has some additional subtleties, but they do not change the essence and for today that’s enough, this is getting very long and surely this is not the place for all this.
I very much appreciate the PBS Space Time series, and Matt’s efforts to “decode” deep concepts to the physics enthusiast community. I see as a very good and necessary thing to incentive the scientific/rational/critical thinking in our society. Even if not always completely agreeing with the concrete things said, agreeing or disagreeing is secondary, because understanding have “levels”, and there is no definitive or “ultimate level”, and it is more important to exercise the rational/critical thinking.
Do you want to find extradimensional beings Matt?
‘Cause that’s how you find extradimensional beings ☝️
I've been thinking a lot about a non-linear wavefunction recently, it seems to make sense. After all, we thought light and optics were linear for a long time but it turns out there's non-linearity, you just need very high intensity or anisotropic media to see it. Its likely that something similar is true for general quantum systems.
Also, perhaps this additonal term of the wavefunction describes a stochastical collapse timescale, and the probability depends upon the number of entangled particles. Any measurement induces entanglement of huge numbers of particles so it would be very likely to collapse, and match experiments. Unsure how you'd prove this though
Apologies for my ignorance. Would you please be able to elaborate on this? I really like your comment.
This sounds a lot like objective collapse theory
The gyoza fairy at 1:19 was a very unexpected reference to dorohedoro. Glad that weird ass manga is receiving the love it deserves!
That, and the "police box" coffee pot as a reference to Doctor Who. loved those little easter eggs.
I watch your videos when I going to sleep at night. It helps a lot to go to sleep very quickly...
I love when I'm following along and have a thought to myself and then it's exactly what you say next. I guess it was sort of obvious where you were going but right before you brought up Schrodinger I thought to myself "this theory must not be complete. We don't have a full understanding and thats limiting us"
Closest I've felt like I'm on shrooms without eating shrooms
Alternate universe you is tripping right now, that's why
I wonder how many times has Matt explain the Copenhagen interpretation, at this point loyal viewers will make the Copenhagen meme-able.
@@grizzomble lmao
@@grizzomble Quantum mechanics make it possible and impossible at the same time.
@@grizzomble Mind if i recommend my fellow Science-Fans
some Stuff?
Science or just Education in General or even just Fun in General?
We must continue learning to break down matter and put matter back together again, this is the whole point to Quantum , if we ever going to have teleportation
And live forever , but I'm still having problems with the gravity suit !
I've never enjoyed a person's ability to speak so well with body language and voice as much as this dude lol every word seems just as mindblowing as the last.
Excellent intro, kudos!
2:10
Doing the same thing over and over again and expecting something different... is what we do when we practice something like our serve in tennis.
The comment at the end about the bubble-like structure of galactic magnetic fields, their origin in supernovae, and our ability to measure them, is completely fascinating and should be the subject of at least one if not three future episodes.
I've never understood how an equation describing a linear system (if that's what Schroedinger's equation does) can also describe a system which has interactions between particles. Aren't these interactions fundamentally non-linear? Sound waves do not propagate forever. They hit things and refract or reflect off. If Schroedinger's equation describes those interactions, then some part of it must be non-linear.
Interactions don't automatically mean nonlinearity. For example, if a bunch of electrons get close together, they'll interact with each other via their electric charges (i.e. repel each other) but their total effect on some other object, say, a proton, is still just the sum of the individual effects. Chemistry would be totally different if this wasn't the case.
Hi Matt, I love your show and I thought this was one of the best episodes ever. I must ask how would “you” and “other you” be able to tell each other apart to know who sends and who receives? Even if it were mutually decided ahead of time which spin direction would determine the sender, couldn’t there also be an “alternate you” and an “alternate other you” in the multiverse who mutually decided that the opposite spin direction would be the sender? In order to sort out such details it seems all sides would need to communicate with each other. Wouldn’t that be a causality-defying situation where, in order to successfully send a message across the multiverse, one would first need to… successfully send a message across the multiverse? Please keep the outstanding videos coming!
Thank you for yet again a scintillating lecture! I enjoy them thoroughly
My understanding:
I would go with the Copenhagen universe in which the wave function collapses at the time of observation
Being a physicist and a follower of Indian Vedantic thought; which says that “ this world is lost to me in my sleep and a different world appears in dream”
So when I am NOT there ( no observer)it ceases to exist
And different realities exist for different people
Wow ur just pulling whole words out of the multiverse huh
After gleaning a bit of the knowledge from your wonderful presentation, I view William Gibsons "Peripheral" so much more tangible! Thanks!
listening to the world around me for a moment, I hear it screeming from pain
Shocked when El' Matt did the intro for a second.
Please do not adjust your set!
I'm a big fan of the many worlds interpretation, and I'd be fascinated if it were true. I hope we get some scientific breakthroughs in quantum mechanics within my lifetime.
There is one breakthrough that explains the many worlds interpretation. Any interpretation that introduces paradoxes is 100% meaningles. And even assuming that it's true. No matter what experiments you run you will never be able to aprove the theory or disprove it. Meaning it's crap.
You're welcome.
@@HakaiKaien That's not how it works. If it's true then it has practical uses which were described in the video. He literally said this in the video, sorry kiddo.
@@housetheunstoppablessed4846 Not my words, kiddo. And yes, that's how science works. If your theory cannot be proven or disproven, you literally have no practical use for it. And that is true for any theory that introduces paradoxes.
Just like the last video, I'm left wondering if there is some chance that the wave functions (or the sum of them) from other universes might interact gravitationally with ours in some way to explain the extra pull of Dark Matter.
Maybe those other universes closer in phase to ours interact more strongly and as the other universe's phase becomes less aligned, the gravitational effect lessons. It seems to me this would create a diffuse halo of extra gravitationally interacting stuff right around all galaxies which kinda sounds like Dark Matter.
Or maybe this is all easily disprovable by someone who has more knowledge on the subject than I do.
Interesting thought however wave functions interacting is disprovable. When we have a system of 1 particle where we know the necessary information about it to accurately predict it’s wave function, we are correct about its position or speed with probabilistic outcomes. If there was other universes interacting with said particle, then the results of a double slit experiment would not match our predictions, because there would be extra interference in the wave. So it’s either we aren’t interacting with any other universes, or the universes we interact with are all nearly perfectly static as to not change our test results and interfere with patterns.
I don’t know anything about dark matter to prove nor disprove anything about it, however I personally believe axions and low energy neutrinos are a much more likely explanation for dark matter than other universes interacting with us
you ought to check conformal cyclic cosmology and what happens at the boundaries between aeons.
💯
2022 possibly God!
WOW a being that most scientist can neither prove or disprove.
FAITH, HOPE AND LOVE.
The greatest is love.
CAN SOMEBODY SUMMON JESUS PLEASE AND GET ME OUT OF HERE?
Oh, that’s right nobody believes but me. Rely on the stars and math and let’s see what happens.
SEE YA’ll SOON MAYBE!
@@nerdsunscripted624
If the only interaction between waves interacting is through gravity then how could that affect our experiments in any detectable way. As far as I know the gravity produced by masses as small as what is sent through double slit experiments has never been detected, nevermind interfere with the trajectory of the other particle possibilities.
After watching this, I came up with a fun “game” I like to call “quantum truth or dare”. It goes like this:
First, pick a dare. The dare should be some sort of experiment, or something with a “success state” that you want to test. You then start the telephone, and begin the “coin flip” as it were. If you got heads, congrats! You get to know the “truth” about that experiment for free! If you get tails… well, you’re the unlucky bastard who has to carry out the “dare”. If your experiment succeeds, you send that message back to the “truth” world.
The game relies on trust in your alternate selves, however, so make sure you pick a dare that you’ll actually commit to. If you REALLY don’t want to do the dare, however, you could always fiddle with the measurement direction/superposition to give heads a much higher probability than tails, but I don’t know enough about the theory to know if that would screw up the communication or not.
RIP Steven Weinberg, a giant of physics and of thought.
I remember reading "Huh that's funny" in something written by Isaac Asimov when I was a kid. I don't remember the title now, though.
en.m.wikipedia.org/wiki/The_Gods_Themselves
I enjoyed Dr. Asimov's essays more than I did his fiction, overall. While his speculations were rational and internally consistent, his character development tended to be weak.
@@jeffthompson9622 I corresponded with Asimov while he was alive. He was a very modest fellow, considering his achievements. He did make some astrophysics related mistakes when he wrote his last book, _Nemesis,_ which was published three years before he died. I told him about them; I probably shouldn't have.
@@Jenab7 He was prodigiously productive as an author, covering a vast variety of subjects, and strove to be scientifically accurate and plausible. Inaccuracies based on subsequent discoveries don't count and a rare error in Nemesis still leaves him ahead of almost everyone who has ever written science fiction.
I would have felt the same way under the circumstances. He strove for scientific accuracy and an inadvertent flaw in Nemesis still leaves him far greater integrity than almost anyone else who has written science fiction.
"Don't get stuck down quote-verification rabbit holes." - Gabe Perez-Giz
He needs to host again just once and use lines like “As I mentioned in last week’s video...” just to screw with viewers.
So one possibility is potential backwards time - travel, and the other seem to allow for hypercomputation if you have access to the entire wave function. Meaning you could construct a Quantum Computer that can do things a Turing machine can't do, such as the Halting problem 🥺
Yes and then add in pocket universes with way faster rates of causality(speed of light) to calculate in virtual computers and you get part of my far future computer ideas.
Need way faster than causality computers to handle movement of everything faster than light in combat along with assumed new branches of math done by smarter than humans computers. Then I greatly reduce the computers abilities in combat by new dark energy jamming thus human crews still required to use one topic only computers that handle tiny parts of the whole controlling of the ships and do repairs as the robots are down.
I use dark matter as a whole new periodic table and dark matter and matter combined molecules in order to do stuff like Uranium stable and other elements stable all the way into the 500's.
Then magic and mind powers are powered by the huge variety of dark energy and dark matter mana and otter magic and ESP particle the Earth just currently in one of the few near voids of those sources in our universe which is why our ancestors believed in magic because It used to work.
Unfortunately I starting to be come a alternative gravity or pilot wave theory person in real life.
had to watch it twice to keep up with Matt. Top class
This was the best of it, mind blowing...
I think this crazy idea just makes it even more convincing that Schrodinger's equation is linear.
Question regarding the mechanics of the theoretical quantum telephone: is each bit of information being communicated with a different multiverse - or is there a way to stay connected and slowly communicate bit by bit?
Wow, great ep.! Writing, comprehensibility, humor, graphics, and presentation were all on-point. And thanks for reminding me of the Quote Investigator site - looks like the true author of that "definition of insanity" quote will never be known, due to the nature of those Anonymous 12-step societies. I enjoyed this 1895 precursor to the quote, though, and the opening phrase that weirdly ties in with the subject of this episode(!):
"Has anyone anywhere in the poetry of the two worlds ever seen such complete idiocy? These ‘Ahs’ and ‘Ohs,’ this want of comprehension of the simplest remarks, this repetition four or five times of the same imbecile expressions, gives the truest conceivable clinical picture of incurable cretinism."
_-Degeneration_ by Max Nordau, 1892, English translation 1895
Or should I have opened with "Megawow…"? 😏
THIS WAS AN AMAZING EPISODE. WELL DONE. I’d like to believe I’m a sharp 23 year old, and I think its important for people to be aware that the concepts covered were brilliantly conveyed. Most people on earth should be watching this, because having an understanding of how the universe you actually live in works and the most up-to-date physics is incredibly important, especially when the medium is unbiased, accurate, and honest. I emplore you to maintain all of your passion, you’re doing the world a very ideologically meaningful and inspiring service.
For the Superposition Theory to apply, a system must be Linear AND Time Invariant. So, Linearity is required but not sufficient. For Superposition Theory to apply the system must also be Time Invariant (the system function of the medium does not change with time). That is a really hard constraint to meet even for RF because the behavior of the medium often changes with time. Because of that, so we often accept that it is "invariant enough" if it changes slowly with no discontinuities. The collapse of the Wave Function sounds like a whopping discontinuity.
Note: Your comment really popped out to me because I just taught a course on Modern Communications Systems in the Spring and LTI & superposition are core to Communications Theory.
As always amazing video!
Could the multiverse telephone be used to effectively double the ammount of available CPU cores in a scifi computer, by having the same computer cores compute different things depending on wich part of the multiverse they are in and then sending each other the results?
Why stop at two multiverses?
@@slickytail Exactly! I just stopped at 2 to illustrate the concept in it's most simple form. Appart from engineering limitations that would surely come up the only limit would be, that transmitting all results to all timelines would at some point cancel out the benefits of another split.
@@invalidstring3447 Man, that sounds kinda like a "regular" quantum computer. Calculating all possible answers simultaneously and then all the wrong ones cansels out, leaving only the right one.
@@simonisaksson3570 You are right, but in the multiverse case the fancy new chip is only the transmitter, while the computation can happen on regular hardware. In a quantum computer you have to redesign your whole arithmatic unit.
Rtx 3090 performance with a 1660
"The Everett-Wheeler Telephone is nothing more than a meta-universe manifold!"
"But the results haven't been confirmed"
@@lenspek7052 "We humans are fools."
The irony of trying to find one interpretation of the Schrodinger equation... maybe it's all interpretations at once!! forever hidden behind the veil of uncertainty and probability :P
Thank both of you!
Okay, so this episode inspired a few questions that are tangentially related;
1. Should we assume that the fabric of spacetime is a homogenous medium in which the wave function always travels consistently? Could something like "The Great Attractor" cause spacetime to be a different "tautness" in some way that varies from general spacetime in relation to wave functions?
2. If humans can position LIGO devices within the local solar system-- would this be enough to measure any sort of decay in the propagation of gravitational waves? Should we expect spacetime to resist these waves in some fashion towards the preferred equilibrium state? Is it possible that some of the gravitational waves detected by LIGO actually came from another universe?
3. Could a large enough cataclysm in the "Pond Next Door" cause any sort of disturbance in our pond? ie, the universe where physics caused a Big Collapse? Someone throwing a big rock in an already "Ripply" pond?
@@goasthmago6354 What a weirdly defensive "explanation" that no one asked for...
You know what thought ive had recently: Since there's particles with definite mass but indefinite position, are there particles with a definite position but indefinite mass?
Mind if i recommend my fellow Science-Fans
some Stuff?
Science or just Education in General or even just Fun in General?
Doing the same thing repeatedly and expecting different results when you're receiving the same results is insanity. Doing the same thing repeatedly and not second-guessing what's going to happen is science.
Faster-Than-Light Communication had been on my mind lately so this was a welcomed addition to it.
In the Warp-Drive episodes there are a lot of unsolved issues to faster-than-light travel. Since energy requirements for the drive are so large, I'm wondering if those theories would better fit FTL Communication since the warp bubble would potentially be much smaller? That is ... if problems currently arising from warp theory could be solved for smaller warp bubbles.
These are two different forms of hypothetical FTL Communications: Tiny Warp Drives and Non-Linear Quantum Entanglement. I'm curious to know if either are detectable at far distances? Let's say Alien World 1 set up a FTL Communication to Alien World 2. Would constant use of a system (either one) eventually lead to observable effects from other distant civilizations such as Earth. Could we see obvious signs of Warp Drive communication "wires" between stars? Could we somehow observe hundreds/thousands/millions of entangled particles being used between two stars (if the use of more than 1 entangled particle would lead to detectable effects)?
Would either of these FTL Communications be useful in attempting to contact a civilization unaware of the sender? Could either warp-driven particles or a barrage of quantum entangled particles be hitting Earth harmlessly, but we're not aware on how to look for it?
I always associate SETI with radio wave detection, but often wonder if we're meant to look elsewhere. And a lot of what's hypothesized on this channel makes me ask: "If aliens figured this out and constantly use it over and over, would that create any sort of effect we could see?" Changes in atmosphere, light signal, waves, etc etc ...
Entanglement is point to point- the data is teleported from A to B with nothing traveling in between. Think of a video game world where somebody suddenly tweaks the color palette for a game object. There's no "signal" within the game's space or time triggering it; it's coming from 'outside' in the sense of the underlying code that generates that emergent environment.
Tiny wormholes are similar. Ones big enough to send objects through should emit some radiation like gravity waves, so they are detectable in principle. Warp drives could also generate gravity waves as they are effectively a way of manipulating gravity to beat the light speed limit. They may also emit a short, intense pulse of radiation when a ship stops (think narrow gamma ray laser). The problem is we'd need to be really (up)lucky for such a pulse to be both aligned with one of our detection telescopes and close enough to stand out from background noise, and both are really unlikely from light years away.
The upshot is that OUR entire civilization is far from being obviously detectable from nearby stars, and unless somebody close by makes a major effort to get our attention we won't see them either.
I have an idea for a "science based sci-fi" story thing. Imagine the internet as is, but with a few more higher "backbones". like Earth's would be more or less how it is, but to communicate with the Martian one, both sets of internets communicate via some kind of higher "entanglement" system. Being the homeworld, Earth would have a higher communication array that, say, entangles with all the other systems in a 400 light year distance, AND connects to an even higher one that deals with connecting 5000 ly ones.
To establish a new connection, you basically need to connect the two at a location, leave/fly one to where it goes and same with the other. Now the fun! Ships can use simple laser arrays to entangle to nearby ships (good for military ops), and/or use the nano-wormholes appearing/disappearing in the quantum foam as a kind of ftl loud speaker. Statistically, the closer to a source you are, the more of the signal you'd get. This is the primary SOS system for the space ships.
As for FTL propulsion, said nano-wormholes can be enlarged by using a specially made gravity plate array (not getting into those here) to basically inflate the space the wormhole is in to macroscopic scales. A little pseudo-science for plot stuff, and the ships effectively "leave the universe" while traveling from A to B in a wormhole. No trace of the path as wormholes leave no trace IRL.
We can't trace wormholes, and if warp drive is a thing, our detectors aren't good enough to pick it up.
Let's say faster than light communication is possible at an arbitrary speed > c and humans can do it.
Let's say there is a spaceship passing by Earth at about 0.99986c (so when a second passes in one frame of reference it sees a minute has passed in the other)
Let's say from the ship's perspective, it sends a message that will be received at Earth just as it passes by and set the moment the ship sends the message t = t' = 0. (t = Earth's time and t' = ship's time)
(1 light minute = 60 seconds * c)
Let's say the closest the ship gets to the Earth is 80 light minutes. And when it sends the message, it is 100 light minutes away from Earth.
A right triangle can be formed here with its hypotenuse 100 light minutes and opposite 80 light minutes. The adjacent will therefore be 60 light minutes.
It will take a little bit more than 1 hour for the ship to travel 60 light minutes. (in the reference frame of the Earth) On the ship, however, only 1 minute will have passed because of length contraction. (also in the reference frame of the Earth)
For the message to travel 100 light minutes in 60 minutes, it will have to go at 5/3 c.
So, at the moment the message is received at Earth, t = 60 minutes and t' = 1 minute
Let's say people at Earth decide to reply and send a message just as they get the message. The ship will receive the message at t = 120 minutes and t' = 2 minutes.
From the reference frame of the ship, it is the Earth that is slower. It will take 2 minutes for it to get the reply but it will see the people at Earth have only experienced 2 seconds. It can now "forward" the reply back to Earth when it is away 100/60 light minutes. (length contraction) Since they can communicate with 5/3 c speed, it will take (100/60)/(5/3) = 1 minute for the forwarded message to reach Earth. So, from the ship's perspective, the Earth will receive the forwarded message at t = 2 seconds + 1 minute = 62 seconds
The Earth has just received the message at t = 62 seconds that it sent at t = 60 minutes which means it received the message before it even sent it! So, if we could communicate faster than light, we could send messages to the past. However, this would violate causality. Therefore, faster than light communication must be impossible.
I think both travel and communication are impossible faster than light
@@Randomperson-dj5yv Hold on, why is violating causality impossible?
This was amazing. Well done!
I loved that unix fortunes program! It provided a seemingly endless supply of witty one liners to post as social media status updates, as well as plenty of other jokes retold for the X,000,000th time... ;-)
Interaction terms in Quantum Field Theory break the superposition principle, because wavefunctions do in fact interact with each other (e.g. electrons emitting photons - the electron wavefunction influencing the photon wavefunction).
EDIT: See discussion below, I was wrong, the equation of motion in QFT is also linear and so superposition holds.
That’s not my impression (though I don’t really understand QFT). There is a thing called algebraic quantum field theory / AQFT, aka local quantum field theory, which describes, uh, iirc a sheaf (over the spacetime manifold) of algebras of observables, and, uh, it has Lorentz transformations (and I think probably also more generally poincare transformations) map to unitary maps or algebra elements or something,
and, so, I think it also satisfies linearity of time evolution.
If it isn’t me who is confused instead of you (and it is quite possible that I’m the one who is confused!), I think the confusion likely comes from the nature of tensor products.
If you have a tensor product of two vector spaces, given any bilinear map from the two vector spaces, there is a corresponding linear map from the tensor product of the two vector spaces, which in a sense is an extension of the bilinear map.
When you make a system out of two systems which each have one particle (of different types, let’s say), to get one with two different particles, you do this using a tensor product.
In this way, you can have stuff that, if the two systems are not entangled but just two independent systems, is like a product of a linear function on one multiplied by a linear function of the other,
but because this is bilinear, we can extend this to the whole tensor product, and the result is a linear function.
I believe the same kind of thing applied when instead of two systems each with a different single particle, we have two fields of variable numbers of particles.
Like, if you have the state space for a single particle of one type, and another state space of a single particle of another type,
If you wanted a state space for “either one of the one type, or one of the other type (or a superposition of these”, you would take the direct sum.
For either of them individually, if you took the Fock space for the space of configurations for the space of the one particle of the given type, that would be the space of configurations for a variable number of particles of that type.
While, if you took the Fock space of (the direct sum of the space for a single particle of the one type, with the space for a single particle of the other type)
You would get the direct product of the Fock spaces of the two separately.
(Just like how exponentiation turns a sum into a product, the “the Fock space of” turns a direct sum of spaces into a direct product (I.e. tensor product) of spaces.
In symbols:
F( A \oplus B) is isomorphic to F(A) \otimes F(B) .
So, I think this is how this could seem to be nonlinear at first glance, while at a closer inspection turns out to be linear.
Thanks for your detailed response. I think what is important to determine, is what we mean by "superposition" or "linear". If we just take superposition to mean the wavefunction can be a linear combination of eigenwavefunctions (corresponding to specific observables), then yes QFT allows for superposition.
However, unlike the Schrodinger equation of QM which actually is linear in the wavefunction, a linear combination of QFT field solutions does not necessarily solve the same QFT equations of motion. You can imagine this like this: wavefunction 1 is an electron moving right, wavefunction 2 is an electron moving left, but wavefunction 1 + wavefunction 2 is not a valid solution as it describes two electrons moving past each other without affecting each other. This is what I was meaning to say when I said QFT breaks superposition -- it breaks the condition "any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state" (see quantum superposition wiki page).
Sorry, a quick clarification. The difference seems to be whether you consider a wavefunction as psi(x) or psi(x, t). You can always sum up any number of wavefunctions that are a function of just space (which corresponds to considering some arbitrary configuration of the universe), but if the wavefunctions are full solutions to the equations of motion (i.e. a function of time) then you cannot sum arbitrary time-dependent solutions.
@@project.eutopia Oh! Just saw your follow up message. Ok, that seems an important difference / seems like it should help resolve my confusion, thanks
Edit: wait, no, that still doesn’t seem to quite resolve my confusion, because my expectation is that the time evolution operator should be linear.
Unfortunately I should sleep soon. I hope to read up on this soon, and I thank you for your comments.
@@drdca8263 Hope you are doing well! Perhaps the following helps clarify what I mean a bit more. While the equation of motion in QM (Schrodinger equation) is linear (it is a linear polynomial in the wavefunction and its derivatives), the equations of motion in QFT are non-linear (and this is due to the interactions amongst the fields). For example take a look at the wikipedia page "Quantum_electrodynamics#Equations_of_motion" (can't type full links here). Both the blue boxed equation of motion for the electron (psi) and photon (A) are non-linear (electron equation has a term like psi*A, and the photon equation has a term like psi^2). This is why linear combinations of time-dependent solutions are in general not also solutions to the QFT equations of motion.
Amazing timing, I was just thinking about how could we erase the Star Wars Sequels.
...What sequels?
😎
None of them are very good.
Definitely one of the very first things to do once we get there xD
I'm glad the "doing the same thing" quote is not from Einstein. It seems there are a lot of mental health problems that have nothing to do with repeated actions or expectations.
Wouldn't it be more accurate to say “The definition of quantum physics is doing the same thing over and over again, but expecting different results.” After all, half the time you get spin up and half the time spin down and you never know which one to expect before you start the experiment.
It's not meant to be taken literally as a definition of mental illness 🤦♀️
@@musicalfringe Nor is mine.
One of the many problems with communicating via text is the lack of tone of voice and facial expression.
@@DavidSmith-kd8mw haha, true enough
6:53 No, it is possible, by definition. Wave function is defined in a space of every possible particle position. Five photons require 3*5=15 dimensions. In essence, every coordinate tuple of wave function is a static universe, and static universes come into motion due to interaction with neighbor universes. Wave function defines measure of existence of each static universe as a square of magnitude and relative phases encode the movement. Particles in old position become much less probable and particles in new position become more probable. So we already interact with neighbor universes.
The problem is that we interact with universes not different from ours that much. Quantum Mechanics is only non-local if you project coordinate of every particle into the same physical coordinates. If you do not project coordinates and let wave function stay as is, an extremely high-dimensional entity, Quantum Mechanics is local. Hamiltonian is local. Linearity of equations does not forbid building a tube into another world that became notably different to ours.
More about possibility by definition. You assume that there is a superposition of "us who tried to call another universe and heard nothing" with "universe that we did not ever call". Well, if you combine them, indeed, nothing changes just because they are nearby. But it does not mean that there cannot exist a universe that we have made a successful call. There are lots of universes drifting apart from us which we were never in superposition with and will never be, so we could possibly restore communication.
Dude, stop advertising that you failed high school science. ;-)
Now it's already a marvelous thing that the different quantum fields have excitations (waves) that interact with each other to form "solid" structures that "stay" in place...
Can you imagine how the world look if we see all these waves in their true form??
"The definition of memesanity is repeating the same joke over and over and expecting a different result." -Onestone
What if, when you get a spam number calling you, this is what's actually happening
My other self wants to steal my identity?
The other universe just wants to talk about my car's extended warranty?
Oh no, I have to fix the timeline now :(
This video was how i found out Steven Weinberg had died. There were never many like him, and there won't be many more. With all the brevity of life, there aren't many worth taking a look in the rearview mirror over, but he is one of them. He was more than a scientist.
Ted Chiang has a great short story about this very possibility. "Anxiety is the Dizziness of Freedom" The story can be found in his collection "Exhalation"
Do you want Kang the Conqueror? 'Cause this is how you get Kang the Conqueror.
If all "interpretations" are acceptable, then why do physicists vehemently hate the pilot wave interpretation?
Probably because it makes QM deterministic and therefore without clear mechanism, or substrate, for consciousnesses to arise.
@Gandalf many worlds is deterministic (because a measurement doesn't cause a collapse to a random outcome). Scientists don't "hate" the pilot wave interpretation, afaik.
@@taxicabnumber1729 Yes, that is true but many worlds solves the consciousness problem by making it possible because each "world" or thread isn't on its own/locally deterministic. A not many worlds interpretation must be non-deterministic for consciousnesses to arise.
I don't know if physicists hate it but it gets backlash because it is impossible to reconcile special relativity with pilot wave. Special relativity proves there is not 1 universal clock and that certain events happen at different times for certain observers but in order for Pilot wave's "hidden variables" to work it depends on there being 1 universal clock that every particle in the universe is running on. With hidden variables the position of every particle in existence is affecting the path a particle takes. But you can't claim that the position of every particle in existence is causing a particle to take a certain path, when the positions of every particle are also relative due to the relativity of simultaneity. Thus hidden variables is a lost cause and so is pilot wave.
@@gandalf8216 why must it be non deterministic for consciousness to arise? Nothing about consciousness requires non determinsinm. I know the idea that our brains and our thoughts might be deterministic upsets some people (it's OK though, they can't help,it ;) ) but we shouldn't base science on those sorts of feelings.
Alter-Matt needs his own show.
since somewhere I have done everything right and wrong and achieved any possible result good and bad, I don't need to do anything here, so relaxing :)
The intro really reminded me of the old c&c red alert cinematics haha. Thanks :D
The writing within this episode bears remark. Ah, I see, Matt handling his own twiddly bits.. how very salient of him, that dork surely shines. 😊
So if you do the double slit experiment with lots of photons, in all alternate universes all observers see a similar pattern, so has the universe actually split at all? Or are they still sufficiently 'correlated'? Could closely related multiverses influence eachother so they end up 'merging'? (The notepad where you wrote the result gets eaten by a dog)
Yup, they would all see the same pattern. So much for "spliting realities" 🤣🤣🤣. It's a theory about madness, nothing more
Old, chubby Matt is DEFINITELY in the uncanny valley.
Uncanny alley where you meet the reflecting rift.
How ironic that the presence of nonlinearities is what would allow us to test an interpretation when it's usually easier to test models with linear equations.
perhaps things like dreams, visions, and deja vu happen when enough particles of our brain that are entangled across the multiverse connect and share 'memories' and/or 'experiences'.