+Nathan Phelps Don't worry, I'm not cutting content, just subdividing it in some cases. Ultimately sequential stuff will just be in Playlist anyway interrupted by 30 seconds of titles and credits, it will help me keep to a more regular schedule of output.
@@isaacarthurSFIA Never shorten your videos.... There is too much of the "science is awesome videos" out there that don't really explain anything..... People what everything quickly part of the problem these days.... Your videos hit sweet spot.
6:40 OMG of course!!! How have i overlooked this obvious thing for my entire life? Of - friggin - course! When we say it takes 100 years for light to reach Alpha Centauri (for example, whatever the actual number is), it simply means that by OUR Earth relative time, it would take 100 years for that photon or information to reach Alpha Centauri. But on the PHOTONS / informations / spaceships timescale, it would only take a second due to time dilation (arguable might not even take a nanosecond, since if you travel AT the speed of light, your time is as frozen as it can get, thus no perceptible time passes between your origin and destination, if we pretend there is no acceleration or deceleration need). You're amazing Isaac. I literally never thought about that, such a blunder. Of course. Its not about how long it takes for an outside observer, its about how long it takes for the "inside" traveller. I feel foolish to have overlooked something so basic for so long. But its not helpful either when even so called astrophycisists on TV literally tell the audience "You can NOT get to a star system faster than the speed of light, it is too slow, it would take 100k years to cross the galaxy! You'd be dead!". I mean are they so idiotic that they themselves also forget to include the fact that YOU on the Spaceship would not see time pass at the same rate, if you go fast enough, you'd be there in an instant. I mean this is exactly why such misconceptions exist, because people in mainstream media that you assume know what they are talking about, are just blatantly ommiting huge factors for the sake of "simplifying". God dammit! When you dumb down the physics of reality just to cater to masses, you CREATE misconceptions and dumb the population down instead. I wish they wouldnt do that.
This is driving me insane :D I can't stop myself from thinking about it for hours, but my understanding of it all is way too limited I never had a single university level course of physics or anything. Still it boggles my mind that with all the insanely advanced modulation techniques that we use to transfer information through different wave lengths and all we can't find a way to beat nature on this one here. :D
It's ironic that tachyons were replaced by quantum entanglement as amethod of FTL communication in scifi. Presumably, this was done to make it seem more realistic, since entanglement is a real thing, but it actually has the opposite of the intended effect, since we know that entanglement cannot be used for FTL communication, whereas tachyons theoretically could be.
@@arnouth5260 ship speed and drama are both greatly enhanced when you have a bridge officer assume the Riker Stance. But only one officer, and only at certain times. Best to know how much is too much.
Wow... i finally found an actually understandable description for how this works. Thanks... I have watched probably 5 videos attempting to explain this, but they didn't speak like a human. As always, thanks for your supreme legibility and judiciousness. I was beginning to believe this concept could only be understood by super deep mathematics or something else i couldn't obtain.
Agreed, part of the joy of this channel is the depth - something mainstream channels and most "educational" cable channels gloss over. Even despite the fact they too are roughly an hour long. They could learn a lot from you. While I don't like the idea of seeing these videos trim down I do like how you reference out to other channels. You do this all the time really which lets you focus on the space that's not well covered. I only recently re-discovered this channel (roughly 5 hours ago). In the past, and now once again, I find your videos are almost like an executive summary to what could easily be a semester course. Its far more in depth than the fluff stuff but doesn't actually launch into the semester lecture series either. Additionally, owing to your effort to avoid overlaps, you generally take the conversation to spaces, ideas, and perspectives that a purpose built formal course could never touch. They don't have the time. It is easy enough to go to one of your referenced videos to learn more. I can't very well expect one guy to narrate the sum of human knowledge for me can I? I like to believe you have an apprentice. This channel should never die.
My wife hates the fact I found you because I watch your videos every free moment I have! Haha! Thanks so much for your time Isaac. BTW, I know you are actively trying to keep the videos shorter, but I like the longer, more detailed videos myself. There are some of us out there! Again, thanks for all you do! -Case
Finally an explanation that makes sense. Thank you. My backgrounds are chemistry and computer programming and I'm pretty sketchy on vast amounts of the fields of physics; it's nice to have principles of Quantum Physics explained in a way that someone with very little physics background (and that mostly Newtonian, anyway) can understand.
i came and enjoyed the quantum entanglement, but that initial breakdown of special relativity was fantastic. it has never made quite as much sense to me as it does now that i've heard you explain it. thank you very much.
+AndDiracisHisProphet Lol, it was supposed to come out at noon EST, but apparently UA-cam has not yet deemed me worthy of their 'scheduled release' function, so it was release now or wait till Sunday :) Fortunately it's a short one, enjoy your BBQ!
That was the best explanation of why you can't use quantum entaglement for ftl information transfer I have ever heard. For the first time I understand the problems. Thank you!
+IH8coleslaw Lol, no but it is the one that inspired the series intro, tachyons were originally going to be in the first episode too, but I wanted to give it a bit more of an extended look to chat about the who causality issue.
These videos are not for people with short attention spans. Love to sit down with a snack and a drink and watch you explain far out stuff for hours. And you know what? We all have a pause button if we need to go to the bathroom or anything else.That thing about the color of sunlight. I thought the sun looked blue when it rose and red at sunset. It's the Doppler effect with light! It's exactly what I thought was happening :) very cool
Thank you so much for this explanation! Finally someone explained this in a way that amounts to more than just "It doesn't work because it violates the First Law Of Things That Work, which says this can't work, therefore screw you." Almost every other explanation I've found before was so abridged it was basically just appeal to authority and it drove me nuts.
Useful for pre determined, randomized decisions over long distances. Both parties look at their coin at a pre determined time and depending on the outcome of the coin flip they take a particular action that was pre determined. It doesn't give any information faster then light, it just decides an outcome out of two options. Say you and another person want to decide something important at a later date and don't want light lag to interfere at the moment of the decision. At the pre determined time, you and your friend look at the coin and get opposite things, so you know what each other got and you then take action based on what you decided earlier. You of course have no way of knowing if your friend actually did what they said they would and vice versa, until you communicate in some other way, but this could be one use of this "coin flip".
Oh wow, an actual insight in the sea of "what if I look at it sideways ?" Well yes, I can now imagine 2 ships flipping a coinon to decide wether to colonize a found planet or go back home. They would not know who flipped the coinon first, but they would know only one colonizes and only one goes home.
@@Stinkflynoob You're right. It works, but it's equivalent to flipping a coin before the journey, taking a picture of the coin's result (while closing your eyes and not looking at the picture), leaving on your journey, and then looking at the picture of the coin's result when you decide to make the decision.
Hm, I remember reading an article somewhere that some scientists found a way to repeatedly check the particle over and over without triggering collapse until it produced the desired "heads" or "tails", and then triggering collapse once it did, transmitting meaningful information faster than light that way. Of course, the particles themselves would need to be delivered slower than light, but once they are, the communication is instantaneous. Though maybe I'm misremembering something.
+Guilherme sampaio de oliveira Yeah, as I mentioned above Tachyons and Time Travel were originally going to be in the first episode too, and we will have to touch on time travel again for wormholes, so it seemed appropriate. :)
the misconception I hate the most is that something is undetermined until you 'measure' it. which is bullshit. something (a quantum state) is undetermined until it becomes entangled with it's surroundings. Or in another word, until that state affects something else and matters in how the world reacts to that state. Which could be a measuring device. For example, you measure your coineon and use a device for that. Suddenly in you device electrons move around, a display lights up, the photons reach your eyes, chemicals are broken to signal the light to your brain, all of that just because your coineon is either heads or tails, and different outcomes for both things. For the same reason Schrödinger's cat doesn't work. A dead cat would not breathe, no vibrations on the box, no air molecules moving by those vibrations, the dead cat would no longer heat the box the same way, etc etc. it's long known before 'you' look inside the box. The dead cat has already affected the outside world differently as an alive cat would. Conciousness, actual measuring devices or even a human observer are certainly not needed for this. It's a bit self centered to convey that notion, don't you think?
Schrödinger's well-known thought experiment was meant to convey the concept of indeterminacy to a world that was grounded in Newtonian concepts and had next to no knowledge of the emerging field of quantum physics. I always looked at it as 'it's not as if the cat is actually IN some intermediate state; it's that the information cannot be predicted from one moment to another *without* observation', i.e. peeking in the box. There are many macroscopic processes we can measure and reliably describe with statistics, and even reduce to simpler formulae (such as radioactive emissions and decay rates) - the point that Heisenberg and Schrödinger brought to the field of physics is that nanoscopic phenomena cannot be modelled with the same mechanistic precision that macroscopic processes (events on the everyday scale our senses perceive) can. The same applies for megascopic processes (things much larger in scale than we ordinarily perceive); weather patterns, the development of forests and fault lines, coronal mass ejections and diffusion of nebulae, all operate in scales that we model in the aggregate, not in total the way we can model the motion of billiard balls on a pool table. My favourite author once put it this way (I am not sure if he was speaking of brownian motion or quantum state analysis, but I think it applies to both equally well): "I sincerely hope that the physicists are not saying what they seem to be saying: that the motions of particles are _in themselves_ random and lawless, not just that we cannot properly measure them."
I reckon an observer is like a blind man swinging a tennis racket at hornets. Depending how he swings it, he can know precisely where he hit a hornet, or precisely how fast the hornet was going when he hit it, or a little of both, but never all of both.
@@twirlipofthemists3201 More or less on target about observation; Heisenberg wasn't stipulating anything about the effect of consciousness, but about the physical act of observation and how interaction with a state or process changes the state or process on the quantum scale. On superposition: I don't fully understand the math, but the physics I generally grasp. It does not make macroscopic, logical sense to say that there is a superpositional state where the cat is both alive and dead: It can be used to describe a particle's indeterminate state, but not that of a system. That's where quantum physics breaks with common experience.
@@HuntingTarg Yes, superposition "can be used to describe" indeterminacy. Whether it's physically true or not is uncertain. Maybe it is, maybe not. I'm just being a jerk even having an opinion about it, but I bet the truth is a third thing; hidden variables, or n-dimensionality / stringiness, or something. I doubt virtual states are real states. And in any case, in no way is consciousness a factor in physics.
The third "misconception", we need to visualize the light as patches of energy, or bullets, instead of a beam, that shots out to Mars. Light doesn't land on Mars (and travel back so you can see it) instantly. So the light spot on Mars doesn't travel faster than the typical "speed of light".
Ever since watching Only Lovers Left Alive, I can't think of quantum entanglement without thinking about Tom Hiddleston using the concept as a metaphor for undying love.
I would say that, in this context, information is that which propagates cause and effect, and in arguably circular reasoning, data or knowledge which may have an effect.
Biggest problem I have with subjects like entanglement is not how quantum physics work or appear to work, but non-intuitive explanations (even if there is the popular belief that the subject is non-intuitive to begin with, I kind of disagree with the notion), you did well here in a way no one else I've seen has done and answered a question I long had!
Now I know why only people I meet for the first time have difficulty understanding me (if I'm not careful with speech). Three videos in and I have a hard time even discerning your speech impediment. It all makes so much sense now.... (You can tell I never spent much effort in hearing myself talk for training!)
I like to think that both particles have their final (opposing) state determined at the point they were entangled, but the state is unknown until it is observed. When either particle is observed, we simply detect that state. The state of the other particle remains unknown until observed as well. It's called the "Hidden variable theory", and it's been debated quite a lot.
Love your video and English is my second language and don’t have any problem understanding you. Thx for captions in video only for technical words. You actually have awesome and nice voice 😎
Yes! I was hoping you'd bring up quantum entanglement as a means of ftl communication. You are my hero! I know shorter videos may be preferred, but I adore lectures. perhaps separate videos for those with much longer attention spans and enthusiasts?
You seem to leave out EPR=ER. Two virtual micro black holes should be able to be entangled (perhaps this is the only way VMBH can ever be entangled). If they are, Susskind says they will form wormholes. These wormholes would be zero length pathways (with zero length they're not even pathways) we might observe as non-locality, with an information barrier since any information would be spread across unknowable virtual hawking radiation. So any reference to entanglement should imply Einstein-Rosen bridges & virtual micro black holes in some way.
+Jonathan Langdale There's no 'seem' to about it, I intentionally left it out. Wormholes, extremal black holes, etc are a topic for another time. The only purpose of this video, besides reminder people how Special Relativity works, was to explain why Quantum Entanglement doesn't equal FTL, EPR=ER doesn't change that, since IIRC they are explicitly non-traversable wormholes.
@@isaacarthurSFIA Observations of close binary stars where the effect would be extreme and quickly noticeable show that gravity must operate at a speed in excess of 20 billion times the speed of light to prevent spiralling orbits. Einstein’s speed limit of light is evidently not a universal speed limit. The Sun and the Earth have instantaneous information about their locations. Of course, quantum experiments have proven that subatomic particles “know” about each other instantly at great distances. But rather than state the obvious, meaningless terms like “entanglement” and “non-locality” are used to remain politically correct to the dogma of relativity
Dear Isaac, At 13:04, you say, “with quantum particles, you have no way of knowing whether your particle has or has not been observed when you look at it.” If that is the case, how do we even know that quantum entanglement even exists?
In other words, if we cannot tell whether the particle has or has not been observed, then how can we even measure this phenomenon (quantum entanglement) to prove that it is actually real?
Because you call your friend and tell you checked your particle. Your friend checks his and you compare results. One of you have 1, other has 0. It works every time. Not too hard ?
Each observer will always see a particle in one state or the other. Neither will know who broke the entanglement, or when, until they discuss it, which can't happen faster than lightspeed.
I have a suggestion. As far as I can tell, entagled photons behave like normal photons if they are not measured. Which means that they should create a wave like pattern in a double slit experiment. Now imagine a device that shoots a steady stream of entangled photons. One photon goes in one direction, the entangled one in the opposite direction. Lets say that the way every photon travels is one light-minute and at both sides, where the photons arrive, there is a double slit. If I turn on the machine, after one minute a wave like pattern should appear on both sides. But what happens if I measure one photon at one side before it goes through the double slit? Physics say that the wave function will collapse and the pattern you will see is that of a particle. The question is, did the wave-function of the entangled photon at the other side collapse too? If so, it would mean that at the same time the first photon was measured, the other photon must get particle properties too, right? Despite the fact that they are actually 2 light minutes away. In that way you can transmit binary code faster than light. All you need is a huge enought stream of entangled photons and a mesurment mechanism that kills the wave function, then you have: wave-pattern = 0, particle pattern = 1. Suppose that you have a beam strong enought to tell the actual states appart, you could swich the measurment several times a second and make a telephone call. Should that work or is there a flaw?
I mean, that would work, but the information would be random. Plus, you wouldn’t know if someone actually DID manipulate the state of one of the photons. Say the machine measures photons, which would have to be in superposition, since they are entangled. If no one messed with the information, the unmeasured photon would pass through the measuring device, and produce a random outcome (remember that you can’t control the outcomes of a superposition, at least to the extent of our knowledge). If someone did mess with the particle, the particle on the other end would pass through the machine and register an outcome which, while it would not be random, would appear random to you as you have no way of knowing that the person on the other end of the line messed with the entangled particle. So basically, it would be impossible to get (meaningful) information without either being able to manipulate probabilities so that when you measured the particle in superposition, it would have a 99% chance of being 1 compared to 50% normally, and/or being able to somehow detect if someone has measured an entangled particle on their end. I can’t believe I typed this out on an IPad....hopefully you got my point, lol.
That sounds right. Probability should collapse and that thing I can never truly grasp - that observed particles actually behave differently based on the observation - should make itself evident in the other member of an entangled pair in a verifiable way, right? There would be three states then: two observed and one unobserved e.g. particle, wave, and uncollapsed hybrid or particle-wave packet. So the binary would be observed V.S. unobserved, in this example either heads or tails V.S. still spinning.
Someone at the other end would have to make an observation to find out what happened. Which in and of itself has an effect. Look up the quantum eraser experiment. The results would suggest that one of the photons would erase the effects of having been observed or not. The information would be successfully communicated faster than light. But only has a 50/50 chance of successfully matching the 0 or the 1 that was intended to be sent.
I'd like to think that someday we'll understand and be able to use the mechanism that causes non-locality directly. Of course there's no real reason right now to think this (other than "I want it to be true") since we have absolutely no idea what the mechanism is, but it's fun to think that it's something that might even be possible to tap into at the macro scale.
They do have some idea about the mechanism, but it is unproven. The info is at point g, an equal distance from both point a and point b, and arrives simultaneously at both point a and point b. Feel free to speculate that point g is in God and everywhere simultaneously, that point g is in an adjacent brain a plank distance from both point a and point b, that in an extra dimension both point a and point b are in one place, that those are all correct, or simply that the mechanism is so weird that we can't guess it. To tease out which / all are correct, instant information communication must be proven or dis proven and not be kept a state secret, among other things.
You have particles 1 and 2 in quantum entanglement, which can be in state A or B. You have actions c, d, e, f and persons 1 and 2. At a set time person 1 makes a measurement of particle 1, then person 2 at a distance makes a measurement of particle 2. If particle 1's state is A, therefore particle 2's state is B, and inversely if particle 1's state is B the particle 2's state is A. So, person 1 makes a measurement, if the particle's state is A he carries out action c, if the particle's state is B he carries out action d. If person 2 measures particle 2's state to be A he carries out action e and if the state is B he carries out action f. For example if person 1 measures state A he carries out action c, person 2 then measures state B and carries out action f. So action c causes action f and action d causes action e. Can it or can it not count as a method of communication? Or maybe I missed something?
14:00 Yeah, I think the method they're using is the boring one that they were already there. As in, the Hilbert Space components were already lined up so that the the coins were opposite. No signal needs to be sent, because none can be sent.
+friedporkrice Not all of them, more and more these days as I get more comfortable with the software, since a lot of times there's no creative commons stock footage available that approximates what I'm trying to explain, but whenever possible I prefer to use stuff already made. Saves time and they usually do a better job :)
I can't believe you mentioned Dr.Suskind! I've been watching his lectures before I even found your channel! first you mention Dunbar's Number, and now this! You rock.
And thus is one of the reasons Quantom Computing becomes so desperately cool. Just one of the possible consequences of Quantum Computing is the possibility that it could allow us to make something useable of Non-Locality.
Hi, recently discovered your channel and love the material. Have you considered covering Railgun / magnetic accelerator space launch tech? To my mind this is essential tech for our space program. 1. 10x + cheaper launch cost opens up space to *everyone*. 2. Enables an orbital spacecraft construction facility for non atmosphere vehicle. 3. A much bigger iss like a city block size, with space tourism etc,, etc. I'm aware that human launch is difficult through such a method, but most everything else is fine, water, metals, hardened electronics, etc... The research is out there but there seems to be too much organisational inertia locked up in rocketry. Great to hear your knowledge.
+fallingblade0com Glad you're enjoying it! I think I covered that subject Megastructures Episode 3 and a bit more in the moonbase concepts video. ua-cam.com/video/zSimYARyL2w/v-deo.html
Algorithms and technology for recognition of this kind information definitely do exist And we are going to find and solve it soon or later ! I hope in our lifetime 👽
Just had an awesome conversation with another fan of yours about philosophy and chemical engineering along with the Drake's Equation... We were discussing this as fireworks were going off and everyone else was celebrating the 4th of July...
Well I don't think it counts as treason as long as you get a hot dog and slice of apple pie in before midnight on July 4th. :) Long conversations about deep subjects over coffee or beer isn't a bad way to spend a holiday.
8:00 My first connotation is with jets faster than sound, is it right? Jets can travel faster than sound, but we are unable to hear them "faster than sound".
Great episode. As always, I find discussion of FTL and the movement of information to be trippy and thought-provoking. i.e. that from a photon's perspective, the universe is tiny (I hadn't thought/known of the 'distance compression' aspect before) and that it gets everywhere instantaneously.
This made sense, I've often wondered why we couldn't harness this, and yes, I was one of the people too blinded by the apparent faster than light data transfer, to stop and reason that it would only ever produce noise without some way to coordinate the 2 sites, eliminating the usefulness as a communication device itself. The problem would be even further compounded by the fact that the clocks on both locations(assuming you would be far enough away to warrant such a device) would not be running in sync either.
THANK YOU! I finally had one of my great questions about relativity answered, and that is that the universe actually "shrinks" the closer that the moving person gets to the speed of light, therefore making the moving person feel like they're going faster than light if they used the measurement before they left and just kept up with progress by using percentages. My question is, isn't this a much better way to do human "deep freeze?" Just send them off to Andromeda at 99.99% of the speed of light and they'll only age a few years before getting there.
Yes and no, it takes insane amounts of energy to get up to 10x shrinkage, if you've got it, and can handle the ultra-relativistic collisions with space dust, then absolutely, see the novel "House of Suns" for some exploration of that theme. I personally would tend to doubt anyone every using that much juice even if they had it though, there's just other better things to do with that energy.
Good series! Very interesting all around! Question: How do you know that the entangled particles don't have their orientation set at the moment of entanglement? I believe Einstein addressed this with the pair of gloves analogy. Put one glove of a pair of gloves in box A and the other in box B, when you open box A you know the state of the glove in box B.
We do know that it is not a hidden variable local to the particles because that would alter the probabilities in some cases. However, it could be that the universe knows before we measure, but that is such a non-answer and is no fun
According to the quantum mechanics, there's no way to predict the spin of any of entangled particles. In this terms they are truly random, but it doesn't means that they're have a particular spin for no reason. Reasons also might be incomprehensible, though.
I think there's a problem with the Mars laser and shadow examples. While you might flick the laser here on earth, its effect and thus the dot it projects on Mars still travel at lightspeed. You might move the laser here but its effect won't reach Mars until 20 minutes later, and so the dot can't be moving FTL. Same goes with the shadow. It's the same reason that if the sun vanished right now, the earth wouldn't be affected by it until 8 minutes later. As you said it yourself, the speed of light is actually the speed of causality itself and hence no effect can travel FTL. All reference frames have to agree on this.
So for sending messages to someone where the receiver couldn't look at their coin until they knew the person sending the message had flipped their coin, would a situation where a predetermined time work? Ex: isaac I'm going to send you a message at 5pm, so you look at your coin at 5:01? Obviously this wouldn't work for a spontaneous message, but would it for a scheduled one?
The problem is that the result you see would still be random. The person measuring the first particle can't control the spin the particle adopts, it's random.
The fix to the quantum weirdness is to do away with particles. There's just one quantum field that propagates changes at c. The "coin" was always going to have that state, the only question is which direction did you measure the flip in?
the Susskind lectures are amazing. just play one of his videos close your eyes and imagine Christopher Walken lecturing on quantum physics. in all seriousness Susskind has like 54 recorded lectures on all topics ranging from quantum electrodynamics to string theory. and yes he explains the holographic principle ( that's his idea by the way. Leonard Susskind is a co-creator of the holographic principle.) I would say he's one step below Edward Witten....... I just had an idea. hey Isaac would you be interested in subbing and subtitling the Witten lectures? even with your speech impediment you're still ten times easier to understand than he is.
+Jon Doe Ducking I knew there was some nagging familiarity about Susskind's speech style. Probably both being New Yorkers, or that "that punctuation I; put it where, it feels right, to me" style of speech. :) Though now that was in my head and I pulled up Witten to remind myself and thought if they wanted to reboot The Godfather they could use him for Marlon Brando. Smart guy, and his dad was a pretty impressive theorist too. I don't think I'd want to try to cover his material, I certainly respect it, and consider M-theory much improved over raw String, but I dislike that whole area as a matter of principle, it seems all math no science, and always has a flavor that reminds me of some of the weirder notions that popped up pre-Einstein or during the geo/heliocentric argument era. Not all contemplation reality need be scientific, but if it isn't testable and falsifiable it ain't science.
Isaac, Im a huge fan! Could you shed some light on a doubt I have? Or could someone else in the comments do it? : Isaac, you said the guy traveling would see as the clock only had 1/2 of its original length, as the stationary observer would see the original length of 1 mile. But, say the clock had a length of 0.87C, and the traveler perseves that as he takes 1 second to pass by it. Wouldn't the stationaey observer also see the original length of 0.87C and at the same time, see the traveler passing by at a speed of 0.435C and taking 2 seconds to pass by the full length of the clock? What I'm saying is: both of them would see the same clock length, but the traveler sees himself traveling at 0.87C and the observer sees the travaler traveling at 0.435C. Therefore, the length is not what is perseved differently, but the speed is. Am I wrong? And if yes, could you shed some light?
I feel like I need to research this more because to me it seems like there is an obvious way to use this for communication. One side could observe then look away and observe again until the bit was in a pre agreed upon state. Then they could continue to observe the bit to keep it in that position. Then the other side just looks at the bit and then away enough times to determine the result isnt random. Then both look away after a fixed period of time. The system would work in cycles of time. Every cycle the sender would flip the bit back and forth until it setteled on the state you want. Then after giving the sender a litte time to set up, the receiver would observe the state. After re-observing to check that the result is not random, you know that the person on the other side is activly observing the bit. And the sender can re-observe their own bit to be able to choose which bit the receiver sees. If you include the possibility of the receiver checking their answer and getting randomness, then you even have 3 bit communication. The only flaw I can personally see is the difficulty of syncronizing your cycles without reliably comparing clocks. But this could certianly be worked around by calculating the time-space distortions on two atomic clocks as they were seperated. Or potentially even with regular light speed communication if your electromagnetic waves can even reach each other. Please tell me what I am missing here and why this cannot be used! Also some sources? General places for a regular guy to learn about entangelmant? LOVE this channel so much thank you Isaac!
as i understand the whole faster than light thing, there's no fundamental law that states nothing can travel faster than the speed of light. It's that nothing below the light speed threshold can be accelerated above it and nothing that exists above it can be de-accelerated below it.
Someone's a PBS Spacetime Fan. Were you able to solve why the delayed time quantum erase cannot be used to send messages back in time. You observe the entangled particles on the future and the other entangled partners in the past stop acting like a wave and start acting like particles passing through an aperture. The experiment works if the entangled pairs are microseconds apart. Observe one of the entangled pair in the future and the other partner behaves like a particle in the past. Mess up the observation in the future and the entangled partner in the past starts acting like a wave. I can't solve why this won't work to send binary coded messages to the past.
After watching a video on the hypothesis of cosmic inflation, the only thing that explains quantum entanglement remains the real vacuum that would be created continuously in space-time between particles, even if this would cause the catastrophe of the vacuum which does not happen in reality. And if it could not be quantized?
I was thinking, in regards to that beam flicking across the face of Mars. This is really similar to the raster pattern on a CRT television. And seeing as the only things moving are electromagnetic fields, and the point on the screen which the electron beam strikes, other than the electrons themselves of course. If you had a long enough CRT you could technically make the electron beam scan across the screen faster than the speed of light. Mind you the speed of this scanning would be limited by whatever oscillator circuit you're using to switch the fields back and forth to control the beam.
Does it have to be a human being who observes it though? Theoretically, a machine is able to determine if the coin was flipped or not and is then able to remember that for when a person comes back in the room. A sort of quantum answering machine, if you will. What I'm interested in is how fast you could flip this coin. If these entangled particles can be flipped hundreds of times a second, that would make binary communication pretty feasible if there's an agreed upon gap between flips that count as 0 and some way to announce when the message begins and ends. Or am I missing something with this?
Using coins as an example would make someone question if telegraphs & Morris codes even worked. The "beep" doesn't carry data, the timing of events does.
You CAN send information superliminally, it just has to be random and you can't have anyway of knowing when this is happening on the receiving end without first being told. But it can be sent nevertheless. That means there is something at work which operates outside of these conventional constraints. Don't look to see how you could make use of the phenomena, ask how it is happening
Perhaps there's an additional use for quantum entanglement beyond one-time-pad encryption. Subsets of the emerging (and practically endless) sequence of observed states could be used for data compression. Transmissions would still not be FTL, but compression from the quantum data source may be able to help boost efficiency to FTL.
If i understand correctly, then the "spooky action at a distance" has to happen instantaneously, because a quantum state is not determined UNTIL we actually meassure it. Has that actually been confirmed or is that just something that the Copenhagen interpretation tells us?
+xassix It's probably instantaneous, in theory it is, or maybe one Planck Time or such, but it's kinds of hard to confirm 0 or infinity, like photon mass, you can usually only rule out that it's 'more than x', like trying to determine the volume of a huge body of water by removing one spoonful, if there's not a visible drop because your equipment isn't sensitive enough you can't rule out that the body isn't infinite, just that it's more than X trillion gallons or something. There's a lot of QM interpretations floating around but to the best of my knowledge none of them have a method for predicting the 'coin flip' so it should be no-FTL in them too. There is still some debate if Entanglement, and the apparent FTL action, is real, but normally that results in no-FTL anyway since if they aren't talking instantly, or near instantly, you can't use them for that. David Kaiser from MIT did an article discussing the loopholes and problem with Entanglement a couple years back in the NYT that you might enjoy on the matter: www.nytimes.com/2014/11/16/opinion/sunday/is-quantum-entanglement-real.html?_r=0
I'm really misunderstanding something about quantum entanglement. There's nothing amazing about the state of one particle being determined by it's partner but, apparently, the amazing part is that the state of the two particles has not been determined until one of them is looked at. This is the part I can't seem to grasp. How do we know that the state of the particles is undetermined until we look at one of them? How do we know the coin is flipping until we look at it? Why could the coin not just exist in a particular state and therefor it's partner's state is also set, and we simply don't know until we check it? What am I missing?
I'm an avid fan of yours and love your videos but I'd like some clarification about misconception #3 @ 6:48. You say that the observer on Mars observing the laser light being flicked across the planet would be faster than the speed of light? If you mean what I think you mean then I'm politely contending that would never happen. That traversing light would travel as fast as the light coming from the laser emitter but not any faster. The observation would still be as fast as, but not faster than light. Imagining that the emitter is pointed at the left side of the planet, and then flicked across the surface, like you mentioned, but let's say the person with the laser goes way past the right side of the planet and ends up 90 degrees (perpendicular) from the starting vector. If you watched this laser from above, you would see a bend in the laser beam, much like a water hose does with the water stream coming from it. That laser traversing the surface of Mars would only appear as fast as light since the laser can't emit any faster than the speed of light. In short, the surface traversal would be equal to the emitter's speed at best. This can be tested with the aforementioned water hose on a wall: the water hitting the wall as you whip the tip of the nozzle is equal to (in this case a little less due to atmospheric drag on the water stream) but not faster than the water being ejected from the nozzle. Ultimately, the same occurs with the laser.
I don't get this coinon thing. Wasn't the exact state of the things set when you created them? Like, if I give one person a blue sheet of paper in an envelope, and another a red then separate them by 1 AU, I shouldn't be surprised when they both open the envelopes simultaneously and find different colors.
Two quick questions: 1. How does observing quantum position change the outcome? Most people tend to assume it's the mind itself, but that doesn't make sense. I imagine it involves photons coming from the particle or something? 2. How do we know that superposition exists if observing a particle causes it to leave super position?
1 - We don't know, its something we've been debating for a century now without much progress :) 2 - look through Bell's Experiment, it might clarify that.
Please don't keep the videos shorter. You have so much to say about each subject, and I don't want any of it cut down! Great videos!
+Nathan Phelps Don't worry, I'm not cutting content, just subdividing it in some cases. Ultimately sequential stuff will just be in Playlist anyway interrupted by 30 seconds of titles and credits, it will help me keep to a more regular schedule of output.
Agreed! I'd happily watch a 2+ hour video made by him because I know it's going to be entertaining and chucked full of info
@@isaacarthurSFIA Never shorten your videos.... There is too much of the "science is awesome videos" out there that don't really explain anything..... People what everything quickly part of the problem these days.... Your videos hit sweet spot.
You put 5 hours video we come back and watch it joyfully 😍😎
M is that a big one 👍 just m up man ooooooooooooooooooo
this channel is giving me tons of realism for my sci fi worlds, I'm so happy is exists.
REALISM! I can feel it in my hands AND IT FEELS SO GOOOD!!
6:40 OMG of course!!! How have i overlooked this obvious thing for my entire life?
Of - friggin - course! When we say it takes 100 years for light to reach Alpha Centauri (for example, whatever the actual number is), it simply means that by OUR Earth relative time, it would take 100 years for that photon or information to reach Alpha Centauri.
But on the PHOTONS / informations / spaceships timescale, it would only take a second due to time dilation (arguable might not even take a nanosecond, since if you travel AT the speed of light, your time is as frozen as it can get, thus no perceptible time passes between your origin and destination, if we pretend there is no acceleration or deceleration need).
You're amazing Isaac. I literally never thought about that, such a blunder. Of course. Its not about how long it takes for an outside observer, its about how long it takes for the "inside" traveller. I feel foolish to have overlooked something so basic for so long. But its not helpful either when even so called astrophycisists on TV literally tell the audience "You can NOT get to a star system faster than the speed of light, it is too slow, it would take 100k years to cross the galaxy! You'd be dead!". I mean are they so idiotic that they themselves also forget to include the fact that YOU on the Spaceship would not see time pass at the same rate, if you go fast enough, you'd be there in an instant. I mean this is exactly why such misconceptions exist, because people in mainstream media that you assume know what they are talking about, are just blatantly ommiting huge factors for the sake of "simplifying". God dammit!
When you dumb down the physics of reality just to cater to masses, you CREATE misconceptions and dumb the population down instead. I wish they wouldnt do that.
God dammit this just changed my whole view.
This is driving me insane :D I can't stop myself from thinking about it for hours, but my understanding of it all is way too limited I never had a single university level course of physics or anything. Still it boggles my mind that with all the insanely advanced modulation techniques that we use to transfer information through different wave lengths and all we can't find a way to beat nature on this one here. :D
It's ironic that tachyons were replaced by quantum entanglement as amethod of FTL communication in scifi. Presumably, this was done to make it seem more realistic, since entanglement is a real thing, but it actually has the opposite of the intended effect, since we know that entanglement cannot be used for FTL communication, whereas tachyons theoretically could be.
so the speed of causality might be a better term?
In a lot of ways yes
Yeah I've always thought it was more accurate and precise to think of it in terms of causality vs speed of light.
@@isaacarthurSFIA Thats exactly what the speed of light IS. It doesn't need a new name. The concept is well understood. Its not even about light
Maybe that's why it's the letter "c"
@@cosmic_gate476 Or maybe it's the first letter of the Latin word celeritas, meaning speed.
BTW, Isaac, I have a pretty severe hearing loss. But, I have NO trouble whatsoever understanding you.
Thanks David
Isaac Arthur you are so wrong everyone knows that you can go FTL with a plot drive
@@arnouth5260 ship speed and drama are both greatly enhanced when you have a bridge officer assume the Riker Stance. But only one officer, and only at certain times. Best to know how much is too much.
Wow... i finally found an actually understandable description for how this works. Thanks... I have watched probably 5 videos attempting to explain this, but they didn't speak like a human.
As always, thanks for your supreme legibility and judiciousness. I was beginning to believe this concept could only be understood by super deep mathematics or something else i couldn't obtain.
Agreed, part of the joy of this channel is the depth - something mainstream channels and most "educational" cable channels gloss over. Even despite the fact they too are roughly an hour long. They could learn a lot from you.
While I don't like the idea of seeing these videos trim down I do like how you reference out to other channels. You do this all the time really which lets you focus on the space that's not well covered. I only recently re-discovered this channel (roughly 5 hours ago). In the past, and now once again, I find your videos are almost like an executive summary to what could easily be a semester course. Its far more in depth than the fluff stuff but doesn't actually launch into the semester lecture series either. Additionally, owing to your effort to avoid overlaps, you generally take the conversation to spaces, ideas, and perspectives that a purpose built formal course could never touch. They don't have the time.
It is easy enough to go to one of your referenced videos to learn more. I can't very well expect one guy to narrate the sum of human knowledge for me can I?
I like to believe you have an apprentice. This channel should never die.
My wife hates the fact I found you because I watch your videos every free moment I have! Haha! Thanks so much for your time Isaac.
BTW, I know you are actively trying to keep the videos shorter, but I like the longer, more detailed videos myself. There are some of us out there! Again, thanks for all you do!
-Case
Finally an explanation that makes sense. Thank you. My backgrounds are chemistry and computer programming and I'm pretty sketchy on vast amounts of the fields of physics; it's nice to have principles of Quantum Physics explained in a way that someone with very little physics background (and that mostly Newtonian, anyway) can understand.
i came and enjoyed the quantum entanglement, but that initial breakdown of special relativity was fantastic. it has never made quite as much sense to me as it does now that i've heard you explain it. thank you very much.
9:56 "Being quantum, that whole Schrodinger Cat issue comes into play"
Made my day.
Damn you, Isaac! I'm supposed to prepare the barbecue I invited my friends to this afternoon, and you are releasing a video....
+AndDiracisHisProphet Lol, it was supposed to come out at noon EST, but apparently UA-cam has not yet deemed me worthy of their 'scheduled release' function, so it was release now or wait till Sunday :) Fortunately it's a short one, enjoy your BBQ!
+Isaac Arthur It was pretty rainy anyways. So nevermind :)
You should have watched the videos with your friends and entertained them in the process. Opportunity missed, lol.
I actually meant to say educated, but I find education entertaining, so it's all the same to me.
@Teodor Terzin oh, a blast from the past...it was a birthday bbc, iirc. so....not really smart^^
That was the best explanation of why you can't use quantum entaglement for ftl information transfer I have ever heard. For the first time I understand the problems. Thank you!
thank you so incredibly much.
+Khannea Sun Tzu Glad you liked it Khannea!
but lightspeed in facuum is like 299 792 458m/s ??? and not 400 km/s it is more like 300000 km/s
oww i understand now
XD i was like about the same until i realized he talks about other particles in this example :D
Will the next episode teach us how to make a sonic screwdriver?
+IH8coleslaw Lol, no but it is the one that inspired the series intro, tachyons were originally going to be in the first episode too, but I wanted to give it a bit more of an extended look to chat about the who causality issue.
Such a clear, concise explanation of a really tricky subject. Thank you for answering all my lingering questions!
These videos are not for people with short attention spans. Love to sit down with a snack and a drink and watch you explain far out stuff for hours. And you know what? We all have a pause button if we need to go to the bathroom or anything else.That thing about the color of sunlight. I thought the sun looked blue when it rose and red at sunset. It's the Doppler effect with light! It's exactly what I thought was happening :) very cool
This channel has been a wonderful thing from the very start. Thank you, Isaac!
Glad you enjoy it!
LOVE your videos. THANK YOU so much for your dedication.
Thank you so much for this explanation! Finally someone explained this in a way that amounts to more than just "It doesn't work because it violates the First Law Of Things That Work, which says this can't work, therefore screw you." Almost every other explanation I've found before was so abridged it was basically just appeal to authority and it drove me nuts.
Useful for pre determined, randomized decisions over long distances. Both parties look at their coin at a pre determined time and depending on the outcome of the coin flip they take a particular action that was pre determined. It doesn't give any information faster then light, it just decides an outcome out of two options. Say you and another person want to decide something important at a later date and don't want light lag to interfere at the moment of the decision. At the pre determined time, you and your friend look at the coin and get opposite things, so you know what each other got and you then take action based on what you decided earlier. You of course have no way of knowing if your friend actually did what they said they would and vice versa, until you communicate in some other way, but this could be one use of this "coin flip".
Oh wow, an actual insight in the sea of "what if I look at it sideways ?"
Well yes, I can now imagine 2 ships flipping a coinon to decide wether to colonize a found planet or go back home.
They would not know who flipped the coinon first, but they would know only one colonizes and only one goes home.
This wouldn't be any different than flipping an actual coin and not looking at the result until you or your friend decide to make the decision.
@@Stinkflynoob You're right. It works, but it's equivalent to flipping a coin before the journey, taking a picture of the coin's result (while closing your eyes and not looking at the picture), leaving on your journey, and then looking at the picture of the coin's result when you decide to make the decision.
Hm, I remember reading an article somewhere that some scientists found a way to repeatedly check the particle over and over without triggering collapse until it produced the desired "heads" or "tails", and then triggering collapse once it did, transmitting meaningful information faster than light that way. Of course, the particles themselves would need to be delivered slower than light, but once they are, the communication is instantaneous. Though maybe I'm misremembering something.
I appreciate you beginning a video and series on this subject with a Doctor Who theme.
What, doctor who opening music? :v
+Guilherme sampaio de oliveira Yeah, as I mentioned above Tachyons and Time Travel were originally going to be in the first episode too, and we will have to touch on time travel again for wormholes, so it seemed appropriate. :)
Thumbs up within the first 5 seconds for that!
@@isaacarthurSFIA
I'm tickled and pickled!, and by now I don't think the BBC is going to 'come getcha'. TYVM 😊
Hoho yes! Another rod from our orbital professor spears into my inbox! You are certainly putting in the hours brother Isaac! Many thanks.
+cyan eyed :) Yes I probably won't be able to keep it up at this pace but I hit a bit of groove on the production end, speeds it up.
the misconception I hate the most is that something is undetermined until you 'measure' it. which is bullshit. something (a quantum state) is undetermined until it becomes entangled with it's surroundings. Or in another word, until that state affects something else and matters in how the world reacts to that state. Which could be a measuring device.
For example, you measure your coineon and use a device for that. Suddenly in you device electrons move around, a display lights up, the photons reach your eyes, chemicals are broken to signal the light to your brain, all of that just because your coineon is either heads or tails, and different outcomes for both things.
For the same reason Schrödinger's cat doesn't work. A dead cat would not breathe, no vibrations on the box, no air molecules moving by those vibrations, the dead cat would no longer heat the box the same way, etc etc. it's long known before 'you' look inside the box. The dead cat has already affected the outside world differently as an alive cat would. Conciousness, actual measuring devices or even a human observer are certainly not needed for this. It's a bit self centered to convey that notion, don't you think?
Schrödinger's well-known thought experiment was meant to convey the concept of indeterminacy to a world that was grounded in Newtonian concepts and had next to no knowledge of the emerging field of quantum physics.
I always looked at it as 'it's not as if the cat is actually IN some intermediate state; it's that the information cannot be predicted from one moment to another *without* observation', i.e. peeking in the box. There are many macroscopic processes we can measure and reliably describe with statistics, and even reduce to simpler formulae (such as radioactive emissions and decay rates) - the point that Heisenberg and Schrödinger brought to the field of physics is that nanoscopic phenomena cannot be modelled with the same mechanistic precision that macroscopic processes (events on the everyday scale our senses perceive) can.
The same applies for megascopic processes (things much larger in scale than we ordinarily perceive); weather patterns, the development of forests and fault lines, coronal mass ejections and diffusion of nebulae, all operate in scales that we model in the aggregate, not in total the way we can model the motion of billiard balls on a pool table.
My favourite author once put it this way (I am not sure if he was speaking of brownian motion or quantum state analysis, but I think it applies to both equally well):
"I sincerely hope that the physicists are not saying what they seem to be saying: that the motions of particles are _in themselves_ random and lawless, not just that we cannot properly measure them."
@@HuntingTarg Wasn't Shrodinger's cat an effort to illustrate the absurdity of superposition?
I reckon an observer is like a blind man swinging a tennis racket at hornets. Depending how he swings it, he can know precisely where he hit a hornet, or precisely how fast the hornet was going when he hit it, or a little of both, but never all of both.
@@twirlipofthemists3201
More or less on target about observation; Heisenberg wasn't stipulating anything about the effect of consciousness, but about the physical act of observation and how interaction with a state or process changes the state or process on the quantum scale.
On superposition: I don't fully understand the math, but the physics I generally grasp. It does not make macroscopic, logical sense to say that there is a superpositional state where the cat is both alive and dead: It can be used to describe a particle's indeterminate state, but not that of a system. That's where quantum physics breaks with common experience.
@@HuntingTarg Yes, superposition "can be used to describe" indeterminacy. Whether it's physically true or not is uncertain. Maybe it is, maybe not.
I'm just being a jerk even having an opinion about it, but I bet the truth is a third thing; hidden variables, or n-dimensionality / stringiness, or something. I doubt virtual states are real states.
And in any case, in no way is consciousness a factor in physics.
The third "misconception", we need to visualize the light as patches of energy, or bullets, instead of a beam, that shots out to Mars. Light doesn't land on Mars (and travel back so you can see it) instantly. So the light spot on Mars doesn't travel faster than the typical "speed of light".
Ever since watching Only Lovers Left Alive, I can't think of quantum entanglement without thinking about Tom Hiddleston using the concept as a metaphor for undying love.
What exactly is "information" anyway?
That's a surprisingly tricky question to answer, I'm not sure I have a good one for it.
Regardless if it's good or not, I'd like to hear your answer.
I would say that, in this context, information is that which propagates cause and effect, and in arguably circular reasoning, data or knowledge which may have an effect.
differences
Check out constructor theory!!!!!
Biggest problem I have with subjects like entanglement is not how quantum physics work or appear to work, but non-intuitive explanations (even if there is the popular belief that the subject is non-intuitive to begin with, I kind of disagree with the notion), you did well here in a way no one else I've seen has done and answered a question I long had!
Now I know why only people I meet for the first time have difficulty understanding me (if I'm not careful with speech). Three videos in and I have a hard time even discerning your speech impediment. It all makes so much sense now.... (You can tell I never spent much effort in hearing myself talk for training!)
Starting at 8:53... "The tachyon (edit in deeper/noticably different voice) "which well look at next episode" is audio awesomeness!
I like to think that both particles have their final (opposing) state determined at the point they were entangled, but the state is unknown until it is observed. When either particle is observed, we simply detect that state. The state of the other particle remains unknown until observed as well.
It's called the "Hidden variable theory", and it's been debated quite a lot.
Love your video and English is my second language and don’t have any problem understanding you. Thx for captions in video only for technical words. You actually have awesome and nice voice 😎
Yes! I was hoping you'd bring up quantum entanglement as a means of ftl communication.
You are my hero!
I know shorter videos may be preferred, but I adore lectures.
perhaps separate videos for those with much longer attention spans and enthusiasts?
Thanks for this. It is the first time I have even come close to understanding the topic.
How about "The Speed of Causality"?
That is the descriptive term I had heard in physics class, and in other descriptions of this subject.
Benjamin Antman no no no real FTL drives will work on Plot-drives
That IS the speed of light, in a more accurate term.
How about the Information Threshold or the Relativity Barrier.
You seem to leave out EPR=ER.
Two virtual micro black holes should be able to be entangled (perhaps this is the only way VMBH can ever be entangled). If they are, Susskind says they will form wormholes. These wormholes would be zero length pathways (with zero length they're not even pathways) we might observe as non-locality, with an information barrier since any information would be spread across unknowable virtual hawking radiation.
So any reference to entanglement should imply Einstein-Rosen bridges & virtual micro black holes in some way.
+Jonathan Langdale There's no 'seem' to about it, I intentionally left it out. Wormholes, extremal black holes, etc are a topic for another time. The only purpose of this video, besides reminder people how Special Relativity works, was to explain why Quantum Entanglement doesn't equal FTL, EPR=ER doesn't change that, since IIRC they are explicitly non-traversable wormholes.
@@isaacarthurSFIA Observations of close binary stars where the effect would be extreme and quickly noticeable show that gravity must operate at a speed in excess of 20 billion times the speed of light to prevent spiralling orbits.
Einstein’s speed limit of light is evidently not a universal speed limit. The Sun and the Earth have instantaneous information about their locations. Of course, quantum experiments have proven that subatomic particles “know” about each other instantly at great distances. But rather than state the obvious, meaningless terms like “entanglement” and “non-locality” are used to remain politically correct to the dogma of relativity
Dear Isaac,
At 13:04, you say, “with quantum particles, you have no way of knowing whether your particle has or has not been observed when you look at it.” If that is the case, how do we even know that quantum entanglement even exists?
In other words, if we cannot tell whether the particle has or has not been observed, then how can we even measure this phenomenon (quantum entanglement) to prove that it is actually real?
Because you call your friend and tell you checked your particle. Your friend checks his and you compare results. One of you have 1, other has 0. It works every time. Not too hard ?
It's been demonstrated in the split-beam laser experiments.
Each observer will always see a particle in one state or the other. Neither will know who broke the entanglement, or when, until they discuss it, which can't happen faster than lightspeed.
I have a suggestion.
As far as I can tell, entagled photons behave like normal photons if they are not measured. Which means that they should create a wave like pattern in a double slit experiment.
Now imagine a device that shoots a steady stream of entangled photons. One photon goes in one direction, the entangled one in the opposite direction. Lets say that the way every photon travels is one light-minute and at both sides, where the photons arrive, there is a double slit. If I turn on the machine, after one minute a wave like pattern should appear on both sides.
But what happens if I measure one photon at one side before it goes through the double slit? Physics say that the wave function will collapse and the pattern you will see is that of a particle. The question is, did the wave-function of the entangled photon at the other side collapse too? If so, it would mean that at the same time the first photon was measured, the other photon must get particle properties too, right? Despite the fact that they are actually 2 light minutes away.
In that way you can transmit binary code faster than light. All you need is a huge enought stream of entangled photons and a mesurment mechanism that kills the wave function, then you have: wave-pattern = 0, particle pattern = 1. Suppose that you have a beam strong enought to tell the actual states appart, you could swich the measurment several times a second and make a telephone call.
Should that work or is there a flaw?
That concept sounds like the Quantum Eraser. Don't know if it'd work, but you can try looking up more information.
I mean, that would work, but the information would be random. Plus, you wouldn’t know if someone actually DID manipulate the state of one of the photons.
Say the machine measures photons, which would have to be in superposition, since they are entangled. If no one messed with the information, the unmeasured photon would pass through the measuring device, and produce a random outcome (remember that you can’t control the outcomes of a superposition, at least to the extent of our knowledge).
If someone did mess with the particle, the particle on the other end would pass through the machine and register an outcome which, while it would not be random, would appear random to you as you have no way of knowing that the person on the other end of the line messed with the entangled particle.
So basically, it would be impossible to get (meaningful) information without either being able to manipulate probabilities so that when you measured the particle in superposition, it would have a 99% chance of being 1 compared to 50% normally, and/or being able to somehow detect if someone has measured an entangled particle on their end.
I can’t believe I typed this out on an IPad....hopefully you got my point, lol.
That sounds right. Probability should collapse and that thing I can never truly grasp - that observed particles actually behave differently based on the observation - should make itself evident in the other member of an entangled pair in a verifiable way, right? There would be three states then: two observed and one unobserved e.g. particle, wave, and uncollapsed hybrid or particle-wave packet. So the binary would be observed V.S. unobserved, in this example either heads or tails V.S. still spinning.
Someone at the other end would have to make an observation to find out what happened. Which in and of itself has an effect. Look up the quantum eraser experiment. The results would suggest that one of the photons would erase the effects of having been observed or not. The information would be successfully communicated faster than light. But only has a 50/50 chance of successfully matching the 0 or the 1 that was intended to be sent.
Nicely done, I enjoyed your explanations, it clarified a few things for me.
I'd like to think that someday we'll understand and be able to use the mechanism that causes non-locality directly. Of course there's no real reason right now to think this (other than "I want it to be true") since we have absolutely no idea what the mechanism is, but it's fun to think that it's something that might even be possible to tap into at the macro scale.
They do have some idea about the mechanism, but it is unproven. The info is at point g, an equal distance from both point a and point b, and arrives simultaneously at both point a and point b. Feel free to speculate that point g is in God and everywhere simultaneously, that point g is in an adjacent brain a plank distance from both point a and point b, that in an extra dimension both point a and point b are in one place, that those are all correct, or simply that the mechanism is so weird that we can't guess it. To tease out which / all are correct, instant information communication must be proven or dis proven and not be kept a state secret, among other things.
Another awesome one. Thanks m8.
You have particles 1 and 2 in quantum entanglement, which can be in state A or B.
You have actions c, d, e, f and persons 1 and 2.
At a set time person 1 makes a measurement of particle 1, then person 2 at a distance makes a measurement of particle 2.
If particle 1's state is A, therefore particle 2's state is B, and inversely if particle 1's state is B the particle 2's state is A.
So, person 1 makes a measurement, if the particle's state is A he carries out action c, if the particle's state is B he carries out action d. If person 2 measures particle 2's state to be A he carries out action e and if the state is B he carries out action f.
For example if person 1 measures state A he carries out action c, person 2 then measures state B and carries out action f.
So action c causes action f and action d causes action e.
Can it or can it not count as a method of communication? Or maybe I missed something?
14:00 Yeah, I think the method they're using is the boring one that they were already there. As in, the Hilbert Space components were already lined up so that the the coins were opposite. No signal needs to be sent, because none can be sent.
Great video! Do you do the 3d graphics in all of your videos? I've noticed they've improved a lot since the early megastructures videos.
+friedporkrice Not all of them, more and more these days as I get more comfortable with the software, since a lot of times there's no creative commons stock footage available that approximates what I'm trying to explain, but whenever possible I prefer to use stuff already made. Saves time and they usually do a better job :)
Having enjoyed your videos, I decided to go back and watch some from before I found you. FTL seemed a fun place to start. And so far, so good.
I can't believe you mentioned Dr.Suskind! I've been watching his lectures before I even found your channel! first you mention Dunbar's Number, and now this! You rock.
:) A lot of topics tend to overlap
And thus is one of the reasons Quantom Computing becomes so desperately cool. Just one of the possible consequences of Quantum Computing is the possibility that it could allow us to make something useable of Non-Locality.
doctor who music! already liking this.
Hi, recently discovered your channel and love the material. Have you considered covering Railgun / magnetic accelerator space launch tech? To my mind this is essential tech for our space program. 1. 10x + cheaper launch cost opens up space to *everyone*. 2. Enables an orbital spacecraft construction facility for non atmosphere vehicle. 3. A much bigger iss like a city block size, with space tourism etc,, etc. I'm aware that human launch is difficult through such a method, but most everything else is fine, water, metals, hardened electronics, etc... The research is out there but there seems to be too much organisational inertia locked up in rocketry. Great to hear your knowledge.
+fallingblade0com Glad you're enjoying it! I think I covered that subject Megastructures Episode 3 and a bit more in the moonbase concepts video.
ua-cam.com/video/zSimYARyL2w/v-deo.html
13:46 A cat box with Schrodinger's cat! LOL!
Algorithms and technology for recognition of this kind information definitely do exist And we are going to find and solve it soon or later ! I hope in our lifetime 👽
you have a amazing channel. i'm trying to watch all your videos now
This cleared a lot of things up, but I'm still confused.
Best way to start out a video
Just had an awesome conversation with another fan of yours about philosophy and chemical engineering along with the Drake's Equation... We were discussing this as fireworks were going off and everyone else was celebrating the 4th of July...
Well I don't think it counts as treason as long as you get a hot dog and slice of apple pie in before midnight on July 4th. :) Long conversations about deep subjects over coffee or beer isn't a bad way to spend a holiday.
True that...
8:00 My first connotation is with jets faster than sound, is it right? Jets can travel faster than sound, but we are unable to hear them "faster than sound".
Yes sound can be a good analogy, though only to a point.
Great episode. As always, I find discussion of FTL and the movement of information to be trippy and thought-provoking. i.e. that from a photon's perspective, the universe is tiny (I hadn't thought/known of the 'distance compression' aspect before) and that it gets everywhere instantaneously.
Love the Doctor Who remix intro!
At last a good explanation of what is possible or not at FTL ...
Make them as long as you can, Issac!
This made sense, I've often wondered why we couldn't harness this, and yes, I was one of the people too blinded by the apparent faster than light data transfer, to stop and reason that it would only ever produce noise without some way to coordinate the 2 sites, eliminating the usefulness as a communication device itself.
The problem would be even further compounded by the fact that the clocks on both locations(assuming you would be far enough away to warrant such a device) would not be running in sync either.
Isaac Arthur 的新系列的第一批文章探讨了“比光快”（FTL），概念和技术。 在本集中，我们回顾了狭义相对论的基础知识以及对此的一些误解，然后看一下量子纠缠。
misconception #2 is surprising. where can i find out more about this? i don't know what to google
so, can we has a video on astrophage now?
I didn’t Kripke had a channel!
Jokes aside.
Awesome work! Thank you so much
THANK YOU! I finally had one of my great questions about relativity answered, and that is that the universe actually "shrinks" the closer that the moving person gets to the speed of light, therefore making the moving person feel like they're going faster than light if they used the measurement before they left and just kept up with progress by using percentages.
My question is, isn't this a much better way to do human "deep freeze?" Just send them off to Andromeda at 99.99% of the speed of light and they'll only age a few years before getting there.
Yes and no, it takes insane amounts of energy to get up to 10x shrinkage, if you've got it, and can handle the ultra-relativistic collisions with space dust, then absolutely, see the novel "House of Suns" for some exploration of that theme. I personally would tend to doubt anyone every using that much juice even if they had it though, there's just other better things to do with that energy.
You could develop a space craft that constantly accelerates at 1 G, giving you both artificial gravity and a ticket to Andromeda in your life time.
Good series! Very interesting all around!
Question:
How do you know that the entangled particles don't have their orientation set at the moment of entanglement? I believe Einstein addressed this with the pair of gloves analogy. Put one glove of a pair of gloves in box A and the other in box B, when you open box A you know the state of the glove in box B.
We do know that it is not a hidden variable local to the particles because that would alter the probabilities in some cases. However, it could be that the universe knows before we measure, but that is such a non-answer and is no fun
According to the quantum mechanics, there's no way to predict the spin of any of entangled particles. In this terms they are truly random, but it doesn't means that they're have a particular spin for no reason. Reasons also might be incomprehensible, though.
I had the exact calculus book you showed in the video :)
It's one of the more popular ones.
Well described
I think there's a problem with the Mars laser and shadow examples. While you might flick the laser here on earth, its effect and thus the dot it projects on Mars still travel at lightspeed. You might move the laser here but its effect won't reach Mars until 20 minutes later, and so the dot can't be moving FTL. Same goes with the shadow. It's the same reason that if the sun vanished right now, the earth wouldn't be affected by it until 8 minutes later. As you said it yourself, the speed of light is actually the speed of causality itself and hence no effect can travel FTL. All reference frames have to agree on this.
Do you destroy the entanglement by flipping it? If not, can you simply continue to flip and measure until you get your desired result?
So for sending messages to someone where the receiver couldn't look at their coin until they knew the person sending the message had flipped their coin, would a situation where a predetermined time work?
Ex: isaac I'm going to send you a message at 5pm, so you look at your coin at 5:01? Obviously this wouldn't work for a spontaneous message, but would it for a scheduled one?
The problem is that the result you see would still be random. The person measuring the first particle can't control the spin the particle adopts, it's random.
you make great videos!
+shayne g Thanks Shayne
The fix to the quantum weirdness is to do away with particles. There's just one quantum field that propagates changes at c. The "coin" was always going to have that state, the only question is which direction did you measure the flip in?
the Susskind lectures are amazing. just play one of his videos close your eyes and imagine Christopher Walken lecturing on quantum physics.
in all seriousness Susskind has like 54 recorded lectures on all topics ranging from quantum electrodynamics to string theory. and yes he explains the holographic principle ( that's his idea by the way. Leonard Susskind is a co-creator of the holographic principle.) I would say he's one step below Edward Witten....... I just had an idea. hey Isaac would you be interested in subbing and subtitling the Witten lectures? even with your speech impediment you're still ten times easier to understand than he is.
I meant to type dubbing not subbing. damned autocorrect.
+Jon Doe Ducking I knew there was some nagging familiarity about Susskind's speech style. Probably both being New Yorkers, or that "that punctuation I; put it where, it feels right, to me" style of speech. :) Though now that was in my head and I pulled up Witten to remind myself and thought if they wanted to reboot The Godfather they could use him for Marlon Brando. Smart guy, and his dad was a pretty impressive theorist too. I don't think I'd want to try to cover his material, I certainly respect it, and consider M-theory much improved over raw String, but I dislike that whole area as a matter of principle, it seems all math no science, and always has a flavor that reminds me of some of the weirder notions that popped up pre-Einstein or during the geo/heliocentric argument era. Not all contemplation reality need be scientific, but if it isn't testable and falsifiable it ain't science.
Isaac, Im a huge fan! Could you shed some light on a doubt I have? Or could someone else in the comments do it? :
Isaac, you said the guy traveling would see as the clock only had 1/2 of its original length, as the stationary observer would see the original length of 1 mile.
But, say the clock had a length of 0.87C, and the traveler perseves that as he takes 1 second to pass by it. Wouldn't the stationaey observer also see the original length of 0.87C and at the same time, see the traveler passing by at a speed of 0.435C and taking 2 seconds to pass by the full length of the clock?
What I'm saying is: both of them would see the same clock length, but the traveler sees himself traveling at 0.87C and the observer sees the travaler traveling at 0.435C. Therefore, the length is not what is perseved differently, but the speed is.
Am I wrong? And if yes, could you shed some light?
And what about those particles I've seen in the past that don't actually chose a direction unless the are viewed. Astonishing & strange !
Great videos.
I feel like I need to research this more because to me it seems like there is an obvious way to use this for communication. One side could observe then look away and observe again until the bit was in a pre agreed upon state. Then they could continue to observe the bit to keep it in that position. Then the other side just looks at the bit and then away enough times to determine the result isnt random. Then both look away after a fixed period of time. The system would work in cycles of time. Every cycle the sender would flip the bit back and forth until it setteled on the state you want. Then after giving the sender a litte time to set up, the receiver would observe the state. After re-observing to check that the result is not random, you know that the person on the other side is activly observing the bit. And the sender can re-observe their own bit to be able to choose which bit the receiver sees. If you include the possibility of the receiver checking their answer and getting randomness, then you even have 3 bit communication. The only flaw I can personally see is the difficulty of syncronizing your cycles without reliably comparing clocks. But this could certianly be worked around by calculating the time-space distortions on two atomic clocks as they were seperated. Or potentially even with regular light speed communication if your electromagnetic waves can even reach each other. Please tell me what I am missing here and why this cannot be used! Also some sources? General places for a regular guy to learn about entangelmant? LOVE this channel so much thank you Isaac!
as i understand the whole faster than light thing, there's no fundamental law that states nothing can travel faster than the speed of light. It's that nothing below the light speed threshold can be accelerated above it and nothing that exists above it can be de-accelerated below it.
I apologize for my ignorance if I am missing something but could someone use the delayed choice quantum eraser to send information in this manner?
Someone's a PBS Spacetime Fan. Were you able to solve why the delayed time quantum erase cannot be used to send messages back in time. You observe the entangled particles on the future and the other entangled partners in the past stop acting like a wave and start acting like particles passing through an aperture. The experiment works if the entangled pairs are microseconds apart. Observe one of the entangled pair in the future and the other partner behaves like a particle in the past. Mess up the observation in the future and the entangled partner in the past starts acting like a wave. I can't solve why this won't work to send binary coded messages to the past.
John Doe I was also unable to solve the problem
After watching a video on the hypothesis of cosmic inflation, the only thing that explains quantum entanglement remains the real vacuum that would be created continuously in space-time between particles, even if this would cause the catastrophe of the vacuum which does not happen in reality.
And if it could not be quantized?
I was thinking, in regards to that beam flicking across the face of Mars. This is really similar to the raster pattern on a CRT television. And seeing as the only things moving are electromagnetic fields, and the point on the screen which the electron beam strikes, other than the electrons themselves of course. If you had a long enough CRT you could technically make the electron beam scan across the screen faster than the speed of light. Mind you the speed of this scanning would be limited by whatever oscillator circuit you're using to switch the fields back and forth to control the beam.
Question: Can you alter the particles at will? If you could and if that affected the particles at the other end, wouldn't that remove the randomness?
Does it have to be a human being who observes it though? Theoretically, a machine is able to determine if the coin was flipped or not and is then able to remember that for when a person comes back in the room. A sort of quantum answering machine, if you will.
What I'm interested in is how fast you could flip this coin. If these entangled particles can be flipped hundreds of times a second, that would make binary communication pretty feasible if there's an agreed upon gap between flips that count as 0 and some way to announce when the message begins and ends.
Or am I missing something with this?
Using coins as an example would make someone question if telegraphs & Morris codes even worked. The "beep" doesn't carry data, the timing of events does.
You CAN send information superliminally, it just has to be random and you can't have anyway of knowing when this is happening on the receiving end without first being told. But it can be sent nevertheless. That means there is something at work which operates outside of these conventional constraints. Don't look to see how you could make use of the phenomena, ask how it is happening
Perhaps there's an additional use for quantum entanglement beyond one-time-pad encryption. Subsets of the emerging (and practically endless) sequence of observed states could be used for data compression. Transmissions would still not be FTL, but compression from the quantum data source may be able to help boost efficiency to FTL.
If i understand correctly, then the "spooky action at a distance" has to happen instantaneously, because a quantum state is not determined UNTIL we actually meassure it. Has that actually been confirmed or is that just something that the Copenhagen interpretation tells us?
+xassix It's probably instantaneous, in theory it is, or maybe one Planck Time or such, but it's kinds of hard to confirm 0 or infinity, like photon mass, you can usually only rule out that it's 'more than x', like trying to determine the volume of a huge body of water by removing one spoonful, if there's not a visible drop because your equipment isn't sensitive enough you can't rule out that the body isn't infinite, just that it's more than X trillion gallons or something. There's a lot of QM interpretations floating around but to the best of my knowledge none of them have a method for predicting the 'coin flip' so it should be no-FTL in them too. There is still some debate if Entanglement, and the apparent FTL action, is real, but normally that results in no-FTL anyway since if they aren't talking instantly, or near instantly, you can't use them for that. David Kaiser from MIT did an article discussing the loopholes and problem with Entanglement a couple years back in the NYT that you might enjoy on the matter:
www.nytimes.com/2014/11/16/opinion/sunday/is-quantum-entanglement-real.html?_r=0
+Isaac Arthur Thanks a lot!
I'm really misunderstanding something about quantum entanglement.
There's nothing amazing about the state of one particle being determined by it's partner but, apparently, the amazing part is that the state of the two particles has not been determined until one of them is looked at.
This is the part I can't seem to grasp. How do we know that the state of the particles is undetermined until we look at one of them? How do we know the coin is flipping until we look at it? Why could the coin not just exist in a particular state and therefor it's partner's state is also set, and we simply don't know until we check it?
What am I missing?
I'm an avid fan of yours and love your videos but I'd like some clarification about misconception #3 @ 6:48.
You say that the observer on Mars observing the laser light being flicked across the planet would be faster than the speed of light? If you mean what I think you mean then I'm politely contending that would never happen. That traversing light would travel as fast as the light coming from the laser emitter but not any faster. The observation would still be as fast as, but not faster than light.
Imagining that the emitter is pointed at the left side of the planet, and then flicked across the surface, like you mentioned, but let's say the person with the laser goes way past the right side of the planet and ends up 90 degrees (perpendicular) from the starting vector. If you watched this laser from above, you would see a bend in the laser beam, much like a water hose does with the water stream coming from it. That laser traversing the surface of Mars would only appear as fast as light since the laser can't emit any faster than the speed of light. In short, the surface traversal would be equal to the emitter's speed at best.
This can be tested with the aforementioned water hose on a wall: the water hitting the wall as you whip the tip of the nozzle is equal to (in this case a little less due to atmospheric drag on the water stream) but not faster than the water being ejected from the nozzle. Ultimately, the same occurs with the laser.
I don't get this coinon thing. Wasn't the exact state of the things set when you created them? Like, if I give one person a blue sheet of paper in an envelope, and another a red then separate them by 1 AU, I shouldn't be surprised when they both open the envelopes simultaneously and find different colors.
How about using double-slit experiment to see if quamtum entangled particle has been measured?
Two quick questions:
1. How does observing quantum position change the outcome? Most people tend to assume it's the mind itself, but that doesn't make sense. I imagine it involves photons coming from the particle or something?
2. How do we know that superposition exists if observing a particle causes it to leave super position?
1 - We don't know, its something we've been debating for a century now without much progress :)
2 - look through Bell's Experiment, it might clarify that.
It was the only true mystery left in physics until dark matter and dark energy showed up
Considering how time dilation works at the speed of light I wonder if it would really seem that long to take a trip at light speed anywhere.