How to Communicate Across the Quantum Multiverse 

For everyone who's curious: The morse code at 9:10 translates to "space time rocks" and "pineapple on pizza is wrong"

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.

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.

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

Perfect timing, I was just wondering how to do this.

How to communicate across the Quantum Multiverse Step 1: Measure charge of electrons emitted from a Stern Gerlach device. Step 2: ??? Step 3: Profit.

Non-linear effects: making physics more exciting one field at a time.

After this episode, I now firmly believe that Berenstain Bears is a cryptic message from an alternative universe.

13:30 This universe just became one bright light dimmer. R.I.P.

Therapist: Slavic Matt doesn't exist, he can't hurt you Slavic Matt: Learn da secret truff off da universss

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.

That cat walking at 3:39 is awesome. Needs to be in more episodes. 👍

As usual... my other self must have left their quantum phone in the car because there's no answer :-(

"The trouble with quotes on the internet is that you can never know if they are genuine." - Abraham Lincoln

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.

The Red Alert reference at the beginning is amazing.

That was an interesting Slavic, Russian, Austrian Matt from a multi-wave function interaction between 3 different quantum worlds, wasn't it?

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?

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!!!

That opening startled me so much.

It would be interesting to learn about some interpretations that aren't so famous as those mentioned in this episode.

Matt: What do you hear? My voice, obviously. Me: * laughs in captions without audio *

Thanks for playing a bit! Helps us calm down and just listen.

This was the best of it, mind blowing...

"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".

Can’t wait for the iPhone 25 with entangled G10 technology

This was amazing. Well done!

After gleaning a bit of the knowledge from your wonderful presentation, I view William Gibsons "Peripheral" so much more tangible! Thanks!

Closest I've felt like I'm on shrooms without eating shrooms

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!

Thank both of you!

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!

"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.

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?

great video very consistent im starting to grasp more of this

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

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!

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?

I can honestly say my mind is blown and I feel like a kid in a candy shop. Thank you for making having Covid and being stuck inside so much fun!

Do you want Kang the Conqueror? 'Cause this is how you get Kang the Conqueror.

Thanks for another great video. As always, I understand nothing but I'm still entertained. One day, something is bound to click.

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

The intro was hilarious! Love it

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.

I wonder how many times has Matt explain the Copenhagen interpretation, at this point loyal viewers will make the Copenhagen meme-able.

RIP Steven Weinberg, a giant of physics and of thought.

Excellent intro, kudos! 2:10

Do you want to find extradimensional beings Matt? ‘Cause that’s how you find extradimensional beings ☝️

Just the title of this video is EXCITING

had to watch it twice to keep up with Matt. Top class

The intro really reminded me of the old c&c red alert cinematics haha. Thanks :D

The gyoza fairy at 1:19 was a very unexpected reference to dorohedoro. Glad that weird ass manga is receiving the love it deserves!

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?

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"

I watch your videos when I going to sleep at night. It helps a lot to go to sleep very quickly...

I / We appreciate the fact, you selected the "Red Phone" from Control [videogame] in the thumbnail! Wise / Understandable decision.

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

Great video. Very interesting👍

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

Shocked when El' Matt did the intro for a second.

Steven Weinberg was a giant among a generation of giants in physics, his contribution to science cannot be overstated.

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.

This seems extremely interesting. Can you please provide the links to the papers mentioned?

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.

I think this crazy idea just makes it even more convincing that Schrodinger's equation is linear.

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... ;-)

This is so good!! go on!

that neck got me, i thought matt went all brendan fraser on us

"Don't get stuck down quote-verification rabbit holes." - Gabe Perez-Giz

Are (could) entangled particles be used like telegraph keys to send & receive private messages, & would the 2 ends have to be treated carefully & similarly to avoid polluting the message while reading it at the 2nd end, since the act of listening at the 2nd end would be detectable back at the 1st end? Also, could this private network be tapped by entangling a 3rd particle? If so, would the action of listening on the 3rd end be easily detectable at the other 2 ends? And so on?

That intro was amazing

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

"The Everett-Wheeler Telephone is nothing more than a meta-universe manifold!"

Thanks for using the term “damp”, versus “dampen”! :)

Fantastic Topic, Great Visuals and Witty Script (had to watch it twice to get all the subtexts) = Fantastic Episode! 0:12 For a second, I was expecting one of the Alternate "Fringe" Opening Credits XD (Brings back memories from the Walter/Walternate story-arc) Q: In the Non-Linearizer Experiment (11:05), What stops "Other-You" from assuming he's "You" and tinkering with the spin on his side too?

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)

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.

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.

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.

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.

An instant classic episode.

I'm really enjoying this episode.. Unfortunately I'm stuck in hosipatl with encephalitis. So I'll be need as it to my "Whatch Later" library 😊😊

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 🥺

Alter-Matt needs his own show.

Can't help but burst into laughter as soon as the video started...

A Tardis coffee pot. I love your fitting little details. 😍

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.

Old, chubby Matt is DEFINITELY in the uncanny valley.

Outstanding

I love your channel, it's one of my favorite. So, I once read that if we build L.I.S.A. It might be able to detect the existence of other universes as they bump up against ours? Do you have any insight into this theory?

Oh no, I have to fix the timeline now :(

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?

I see that Dumpling man @1:00, nice Dorohedoro reference in my physics video ;)

I Very Much Enjoy All of Your Explanations of Knowledge, That If I Had to Read it On My Own; ( would certainly take longer to figure out) ! How might I purchase some of those Real Cool T Shirts You Sport ? Have a Great Night/Day.

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.

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

I've been having indeterminate results with this. Happy to see you've uploaded this tutorial video.

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??