Does Quantum Entanglement Allow for Faster-Than-Light Communication?
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- เผยแพร่เมื่อ 14 พ.ค. 2024
- Quantum entanglement allows particles to affect one another faster than the speed of light. So does this mean we could one day build a device to exploit this and enable superluminal communication? A popular trope in sci-fi for sure, but today let's look at the science.
Presented by Prof David Kipping (Columbia). Special thanks to Prof. Ehud Altman (Berkeley), Prof Tim Byrnes (NYU) & Prof. Raquel Queiroz (Columbia) for fact checking our script.
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::References::
► Gisin (2014), "Quantum measurement of spins and magnets, and the classical limit of PR-boxes", : arxiv.org/abs/1407.8122
► Pawlowski et al. (2009), "Information causality as a physical principle", Nature, 461, 1101: arxiv.org/abs/0905.2292
► Einstein et al. (1935), "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?", PhysRev, 47, 777: journals.aps.org/pr/abstract/...
► Salart et al. (208), "Testing spooky action at a distance", Nature, 454, 861: arxiv.org/abs/0808.3316
::Further video resources::
► "Why You Can't Use Quantum Mechanics to Communicate Faster Than Light?" by Looking Glass Universe • Why Can't You Use Quan...
► "The puzzling tension between faster-than-light communication and quantum mechanics" by NYU Quantum Technology Lab: • The puzzling tension b...
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::Chapters::
00:00 The FTL Dream
02:10 Relativistic FTL?
03:41 Quantum FTL?
06:27 Quantum 101
09:01 FTL Action at Distance
10:33 How to Exploit?
12:23 Idea 1: Repeat Measurements
14:16 Idea 2: Double Slits
18:04 Idea 3: XY Switching
22:20 Where From Here?
28:11 Outro & Credits
#Quantum #ftlfasterthanlight #CoolWorlds - วิทยาศาสตร์และเทคโนโลยี
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I love how many of these videos with a question in the title turn out to be "probably not", because you're clearly not setting out to prove these things wrong; in fact you (and maybe most of us) want the answers to be 'yes', but you seem to really work through the science and find that the evidence is just not there. This is the sort of critical thinking we need to teach.
Except that our understanding of sciences laughably and complete. It's openly acknowledged that we can't account for 96% of the effects within the universe. We want to call it dark this or dark that but when you consider how quantum particles are said to pop in and out of fields and combine that with us calling the universe so-called dark, isn't there a lot to say there could be more that we don't know like other dimensions
It's sad how so few people actually understand that the scientific method doesn't just bilaterally prove or disprove something tested - either the results are statistically significant in a way that supports one's hypothesis (and further research is necessary for any kind of confidence in confirmation), or you get the "null" result of "something else", which doesn't prove or disprove anything either, it simply indicates that the very specific variable tested is not the cause to your very specific effect (and further research is necessary for any confidence in de-confirming anything).
Basically, no matter what the result, further research is necessary nearly 100% of the time.
@@chrisbarry9345 I was careful to say 'probably' because yes, of course there could always be something we haven't discovered yet
@@chrisbarry9345 I can account for 100% 'of the effects within the universe'..... God.
@@rockdesertsun8246 I hope that's sarcasm, otherwise it's a literal logical fallacy to bring in an "argument from the metaphysical" because all rules of logic are now out the window in a debate/discussion.
Saying "God did it" is the singularity of debate - once you pass it's event horizon, it's impossible to continue that specific course of logic.
I've watched, read, and listened to hours of explanations of why QEC should be impossible, and you effortlessly, finally made it clear. It's so much simpler than I tried understanding that it makes me a little frustrated that it's been so poorly communicated by others.
And I still think we should try to attempt the impossible.
If we just decide stay within the boundaries of what we think are the laws and limits, we just end back at the 1899s when patent commissioner at the US branch made the claim "everything that can be invented has been invented."
Yes, I am fully aware that lot of stuff is very likely just as it seems, but we still are going to hafta push the boundaries, otherwise, how are we going to fully map out all of said boundaries?
Plus, outside the box thinking is what got us the theory of relativity and quantum theories after all.
Science should not deal in complete absolutes. If someone tells you "this will never work" they are likely not worth listening to. If they say that "by our current understanding of how things operate it should not work", then they are worth atl lending an ear to.
Again, ofc you should ratio your doubts in accordance in science to how well something has been tested, but you should not just wave off left field ideas before you have made sure to make the appropriate tests to confirm that is something that doesn't seem to work.
There's still a little problem there. Bell's experiments so far show that entangled pairs are NOT like pre-selected left or right shoes in sealed boxes. The selection really does happen when the "boxes" are opened. Perhaps one day we can find how to exploit this.
@@Elmithian Oh, I totally agree!
He did a great job explaining
Yeah, that's something I've noticed in general. Physicists are terrible at communicating their field.
This is a very informative video. Quantum entanglement cannot be used for FTL communication, due to its inherent randomness. But there's another thing worthy of note here.
The consensus is that information and causality don't travel faster than light.
With quantum entanglement, the collapse of the wave function after measuring one particle, is transmitted to its entangled partner much faster than light. But this is not called "information", but "action at a distance".
But information and action have blurred boundaries between them. Every exchange of information involves a physical action. For instance, if I get information through sound waves, the waves have to do the action of vibrating my ear-drums. And if I use my arm to lift a book, I am also sending it the information to alter its spatial co-ordinates.
And it is not said that it travels "faster than light" (well, you said it in the vid, and kudos to you for that, but some others don't), but that its "non-local". It seems to me that these distinct terms for quantum mechanical phenomena only obscure the simple fact that:
We have discovered three speed limits in nature.
1. The speed of sound in any given material, which is the natural speed limit of mechanical waves in that material. Nature has many random sources of sound, like thunder. But we can use sound in a non-random way to communicate.
We also surpassed the speed of sound with supersonic technology and EM waves.
2. The speed of light in the vacuum. This is the natural speed limit for matter/energy travelling relative to the reference-frame of another system of matter/energy, as well as information and causality travelling between systems of matter/energy that are not quantum entangled. Nature has many random sources of EM waves, like lighting. But we also learned to harness EM waves for communication. We also learned to detect random sources of gravitational waves, though we can't harness gravitational waves yet.
The only source of faster then light transfer of information/action that we know of so far is number 3 below.
3. The speed of transmission of information/action at a distance, from one quantum-entangled particle to its partner, to maintain the entanglement at a distance; as well as the collapse of the wave function from a measured particle to its entangled partner. Here, the entangled particles are natural, random sources of...whatever it is that is being transmitted between them to maintain the entanglement.
A classical analogy to quantum entanglement might be acoustic resonance.
An even closer analogy might be the *synchronised*phase*opposition*of*two*pendulum*clocks* (you can google it, its interesting). Here, the means by which the synchronisation is maintained are:
the "non-local hidden variable" of acoustic waves transmitted from each clock to its partner
through the substrate (say, a wooden beam) to which they are both attached.
If we can identify the "whatever-it-is" that is being sent by entangled particles to each other, to do action at a distance between them, then we can dispense with quantum entanglement, and build a device that uses this "whatever-it-is" to communicate faster than light.
Have you made, or are you planning to make a vid about interpretations of QM that involve non-local hidden variables ("whatever-it-is"), like Bohm's pilot wave, and their possible use (or not) for FTL communication? It would be interesting to hear your take on this.
Hi, I built a simulation setup that demonstrates FTL communication. Maybe can check that out? th-cam.com/video/hYZQTw-BoME/w-d-xo.htmlsi=lcKdBBlY2g8Lsfwf
Plenty of things travel faster than the speed of light including some galaxies
@@jordanwhisson5407 cap
The notion you refer to in 3 has a dubious premise, that "collapse of the wave function" is a "thing that happens". While that is presumed in the Copenhagen interpretation, there is no scientific support for this premise. It's not in the mathematics of QM. If collapse is not a thing, then there is nothing to transmit. Spooky action at a distance is an illusion. After omitting pilot wave theory and it's relatives for various good reasons, we are left with Many Worlds, which is simply nothing more than QM taken at face value without adding any nonsense about collapse of the wave function.
When Alice measures the spin as Up, absolutely nothing whatsoever "happens" to Bob's electron and nothing is transmitted. What we do know is that Alice shares a world in which Bob has a Down electron.
Or to put it another way, Alice and Bob are in a superposition of states such that Bob-with-up-electron can only encounter Alice-with-down-electron an vice versa.
Collapse of the wave function, should be regarded as an anthropic subjective experience rather than a physical phenomenon, in the same sense that finding yourself here and now is an anthropic subjective experience.
@@jordanwhisson5407 That's not velocity. They are just receding away from us at faster than light speed due to expansion of space but they are not moving/traveling faster than light. You've got the wrong understanding of that notion
I read this terrific sci-fi series called The Gap, by Stephen R. Donaldson. I was in my teens, so I had no notion of the idea of entanglement or quantum. In the books the aliens called the Amnion, had this crystalline device that allowed them to communicate not only faster than light but essentially instantaneously. The shock of the human characters when discovering this was truly chilling. They could place their ships where they needed to be without dispatching a gap courier drone to cross the void. Truly hideous.
Isaac Asimov. + Philip K Dick. 💘💘
Causality dictates that no one has finished this video yet at the moment I’m posting.
Im Watching At The Moment,But Was Thinking The Same Thing😂😂😂
what if someone watches it at 2x speed
@@wzrd7023 ...and ½ speed on another device.
That just means Patreon members get to enjoy miracles. 🤔
You can if you set the video playback speed to FTL
Finally! An explanation I can actually understand. Your ability to communicate very complex ideas in such a clear and understandable way is by far the best I've come across. Keep up the great work!
If something is reacting at faster then light speed there is energy traveling at faster than light speed. Should be common sense.
Also wormholes are possible in physics. Space can move time faster than light. Black holes singularity universe sees black hole frozen from aging, but it’s only perspective. The black hole can experience the universe aging faster into infinity even experiencing events that the universe can’t yet experience. The concept of negative energy that NASA claims is created by gravity.
All that + lovely voice!
So, I know this will probably never been seen, but what if Bob and Alice have 2 entangled particles. If he wants to say yes, he collapses one of the particles and leaves the other entangled. If he wants to say no, he collapses both particles?
The only way Alice can know if any of the particles collapsed, is by taking a measurement and collapsing them herself if they werent already, so she can't know if only one of the two was collapsed.
Good question good answer!
Why cant the particles be collapsed in a rythem like morse code? You just register collapsing and the pauses between them...
@@kosterandpartnersyou can collapse the particle with any rhythm you want, the receiver needs to collapse his own particle in order to read it, so you are only able to know the state of the particle at that specific moment.
@@Zr0Bites I thought if bob collapses, Alice collapses instantly. This disentanglement would be noted by the scientist.
If there are two sets of entangled particles, but one morning the scientist comes into the lab and one set is no longer entangled, that’s a “yes”. (If both, “no”, if neither then the experiment is still running)
I always click on these videos knowing the answer is gonna be no, but always hoping I’m wrong
It's the first time I actually understood entanglement, very well done mate, I always love your way of explaining.
Why did nobody else explain the shoe box? That's all they have to say!
@@immortalsofar5314 Because the shoe box by itself doesn’t do it justice. People still get caught up in thinking about “well, both know that the other has the corresponding pair, so they have a full set!”. This indicates a thinking that some how you can come to a forced measurable result. Kipping explained beforehand that it’s entirely random, and that no matter what you do to the entangled pair, it always results in a randomized dice roll that provides no relevant information if you only have half the set. In other words, if you get a left shoe. You don’t know that you have a left shoe, unless you can see the data of the other party. The shoe is only a left shoe, relative to the other previously entangled particle. Without knowing the state of the other particle, you’re left with an annoyingly undefinable particle.
This is also where the Heisenberg uncertainty principle comes in. Measuring for one vector, increases the uncertainty in another vector. Measure it’s location, and the speed becomes blurry. Measure the speed, and it’s location becomes blurry. You need multiple measurements, but only one measurement can be applied before the super-positioned entanglement ends.
just put it in transparent shoebox 😂
@@gravoc857 it sounds to me like quantum entanglement is not FTL in its action. It sounds to me like entanglement just imparts opposing Quantum fields causing them to collapse in the opposite directions when observed but not transmitting any information instead revealing their pre determined bias
@@matthewfrost3677 That’s what I used to think. That the information is perfectly symmetric. We need to remember though that measuring one particle will instantly reveal the nature of the second particle, no measurement required. If you and I’s assumption was correct, an entangled pair would require two measurements.
This is literally the best channel on TH-cam
You finally helped me understand why QEC should be impossible, you have a knack for explaining complex things , thank you, keep up the good work!
One of the great videos on TH-cam, great job dude!
I am really proud of thinking up the "tachyonic telephone" when I was younger. I only discovered that someone had dreamed it up almost 80 years before I did, but I love the theory. Using tachyons, which may travel backwards through time, you can send a message to a far away receiver. They would get the signal in the past, relative to the distance light takes to travel that distance. I can form the idea in my head, but can't explain it. If you look up the term, someone else can do a better job than me.
so technically tachyons don’t actually travel backwards through time, time is always moving forward with entropy and entropy can only be reversed by chance for split seconds at a time and i have no clue what im talking about why are you reading this
Tachyons don't actually exist though. There's zero evidence to even remotely suggest their existence.
But in reality, if communication with the past/future was actually possible...Tachyons wouldn't be needed. Simple Photons would be.
You see, Photons, being massless, always travel at the speed of light. We know that anything travelling at the speed of light cannot experience time. From the perspective of the photon, there's no causality. Its emitted, travels and arrives instantaneously.
Which then raises an oddly interesting point. If the Photon does not experience causality, in the classical sense of cause-effect, then all events that a photon is subject to, influences the photon throughout it's entire existence as we perceive it. So, observing a photon today, will have influenced that very same photon in the past. Scientists have proven this via the Delayed Choice quantum eraser experiments.
The sad fact however, in order to observe such a change in the photon in the past, you must first know what change you have actually made to it. So the only way to decipher the information, is to first know what information you're trying to decipher. Hence, its not possible to send information faster than the speed of light.
@@WeRemainFaceless the photon follows a null geodesic path....interestingly this is how information gets around the universe. On the photonic level of reality it is instantaneous or synchronous.
9
@@WeRemainFaceless the very fact that photons are massless means they have a zero decay rate and thus don't experience 'time' aka change. Photons can travel at a speed anywhere between zero and infinity depending on the permeability and permittivity of the space it is traveling through.
Nothing can go back in time because causality is instantaneous. Once an event takes place, it can never be changed. You can however 'witness' the event again in another location in space.
The speed of light is the fastest information can be transmitted but you lose information with distance so the only thing you will 'see' are specs of light.
You can't really do FTL though because electromagnetic waves are energy waves and the universe is made of energy. You would have to enter hyperspace or subspace where travel is faster than normal space.
I'm no rocket scientist, I can barely wrap my mind around what you're saying, but I am a science nut, I love all things space related. I love your presentation, for lack of a better description I find this video soothing? Its like Relaxing and learning at the same time. Sorry if I'm weird.
You're not weird. I get the same sense when I watch Dr Kipping's videos.
As I was watching the 6 problems with warp drive vid, I was thinking what about entanglement, and if we could control a collection of entangled particles, etc.
So I’m excited to watch!
i must say, i just subbed a couple months ago, but this is a GEM of an episode bro! good work!
Every single time I thought of a potential solution, you said it right as the thought was entering my brain, in the same order I thought of them.
what did you expect? experts know what they're doing.
@@rosaeruber225 he's positing it as a thought experiment. I was playing along. I didn't really expect to think of a solution while I sat watching a youtube video. It was more that I had a repeated series of "why not _______?" just as he started to explain that very solution each time.
OutSTANDING work here. You took the whole thing apart and put it back together for me to understand that Einstein's limit is really about causality and the nitty-gritty of why all of my little fever-dreams for FTL communications are impossible using entanglement. In half an hour. Bravo.
My heart is broken, of course, but you let me down as easily as anyone could have, and your closing remarks about facing reality as it is was right on target. Thanks.
What we observe in quantum entanglement isn't possible according to relativity. The fact that we can't use it to communicate doesn't change that, if the particles can use it to communicte faster than light (as our observations currently seem to show) is enough to violate relativity. There seems to be no phycisist that currently can explain what we observe in QM. They don't know and can't say.
@@cyberfunk3793 Wrong. Nothing is violated here. The information can not travel faster than light and as the video explains, you can't send any information using QE even tho its faster than light. Its "nothing" that travels faster than c
@@Skrzynia Special relativity is obviously violated by entanglement unless you think you know better than Einstein who wrote the theory. Einstein obviously agreed QM violated the principle of locality, that is the reason why the EPR paper came to be. The principle of locality means nothing (energy or matter) can travel faster than light, so no interaction can happen faster than that between A and B. It doesn't say, that we just can't use it to send information, that is an excuse people nowadays use when they don't wish to accept reality and that local realism and specialy relativity has been refuted empirically. The only way to avoid this conclusion is superdeterminism, so unless one is actually advocating for that they can't imply entanglement doesn't violate local realism. My personal opinion is that superdeterminism is absurd and really a childish cop out for people unable to follow the evidence when it takes them to inconvenient conclusions.
I don't know how to express how wonderful these videos are. I guess I can only say thank you David!! I love what you're doing
Yes, it is possible to use quantum entanglement to send information. This is known as "quantum teleportation," although it does not involve the actual physical transport of particles.
In quantum teleportation, two entangled particles (typically photons) are used to transmit information from one location to another. The sender performs a measurement on the particle they wish to transmit, which destroys the original particle but also allows them to determine the state of the particle. They then send the information about the state of the particle to the receiver using classical communication methods, such as a phone call or internet connection. The receiver can then use this information to perform an operation on their entangled particle, effectively "recreating" the original particle with the same state as the one that was destroyed at the sender's location.
The advantage of using quantum teleportation is that it allows for secure communication, since any attempt to eavesdrop on the transmission would disturb the entangled particles and be detectable. However, it is important to note that quantum teleportation alone cannot be used for faster-than-light communication, since the classical communication step is still limited by the speed of light.
This is utterly impossible too because of the uncertainty principle.
I'm sure this is the reason we haven't progressed too much with time travel. You mean I have to destroy myself to test it out? What about James. He never does shit around here anyway
You seem to be describing the QKD BB-84 protocol. Despite the name, QKD is about agreeing on a key (mutually determining a key), NOT transmitting a key. You create a stream of pairs of entangled photons -- one is "read" by one user, the other by a second (and at least one of the particles has to be sent, speed of light to the other end of the channel). The classical channel (speed of light) is used to determine what measurement to make/which particles to measure. The HUGE problem with such approaches are that they are slow (bitrate - relative to conventional comms) and although they are secure because you can DETECT eavesdropping, they are EASY to "jam."
Such a lovely video with amazing closing comments that are applicable for not just the context of this video, but life in general. Thanks for all your videos. Really love the way you explain things with such ease and fluidity
It was cool to finally find someone who would delve into all the what-if's of FTL/entanglement attempts. One thing I think that could have helped was to clarify how it doesn't really help to collapse a state as a signalling mechanism either, as there is no way to _see_ that a state has collapsed without observing the particle. And of course, observing the particle collapses the state.
These videos are awesome.
Also, wish I had read this comment before taking 30 mins to figure that out on my own. Ha.
Can't information be encoded by Bob delaying the second observation after his first? E.g. If he waits 1 second after the first observation (before making his second observation), then it's a "1" and if he waits 2 seconds then it's a "0"? Alice then doesn't have to care about spin direction, she just has to note whether it's 1 or 2 seconds between her first and second disentanglements happening. (I know nothing about all this, so sorry for wasting time if it's a nonsensical suggestion.)
@@AndrewJens No, because again, you can't tell if Bob has collapsed his state. If you look at a particle _after_ he observed his copy, you see a random spin (which later you could confirm was the opposite of what he saw). If you look at a particle before he observes his, you see a random spin (which Bob can later confirm was the opposite of what he later saw). The two states look the same to you: you saw a particle with a random spin. You can't tell if he's observed his or not - it's not like the particle turns red or something when Bob observes it so you know it's go time. You're not looking at it when Bob observes his copy - how would you know anything happened?
@@RyanEglitis Ah, so I'm not understanding it at all (but thanks for taking the time to reply). So how does Alice detect the collapsing of the spin state of her particle (assuming she's a keen observer and is watching continuously)?
@@AndrewJens It's my understanding that you would detect it by interacting it with some other particle (i.e. electron, photon) and then multiply up the result to something human scale. "Observing" something is just a way of saying "interact it with a bunch of stuff so that we know the state of it (at the time of the observation)". It's part of why it's hard to keep entangled particles - you need to keep them away from _anything else_ that could interact with them. Even if we don't _see_ the result, the entangled state would get lost.
If we can choose the axis in which the quantum wave collapses, regardless of orientation, we could express it as such:
X = 1
Y = 0
That way the receiver will always be able to decipher the message.
Alternatively, even if the wavefuction doesn’t collapse in the desired state. Couldn’t a Hadamard Gate set it back to Superposition until you get a new state?
You did this video really well. Thank you.
This cleared a lot up for me, many scientists have explained that it's impossible to transfer information with QEPs but never why. I now realise that entanglement is a one time measurement deal and that you can't alter the state of the entangled particles at will.
If any interaction with an entangled particle collapses its state, then there's no way for Alice to observe changes without affecting the state of the pair.
In other words, if there's no way to observe (let alone affect) a particle state without collapsing it, this system is pretty useless as a mean of communication.
To me, that seems like the real kicker at the base of it. If the receiver has to monitor for changes, then it's already collapsed by the receiver. The whole transmit-receive concept won't work.
I don't think I completely understood, because it seems you can keep both particles on a perpetual double-slit experiment, and only collapse one when you need to send a bit.
So Bob and Alice agree that at time t, Bob will either take a measurement of the particle (meaning a one), or leave it alone (meaning zero). So if Alice who is watching the particle going through the slits, sees a collapse at time t, she knows that the message is one.
What did I miss?
@@VikingTeddy My thoughts exactly. Collapsed or not collapsed is just as good a binary system as left/right or up/down. All you would need is an agreed frequency. I'm sure I must be wrong, but I'm too dumb to know why.
@@VikingTeddy I think by doing the slit experiment you will collapse the particle, as you're measuring its state
@@spacenoodles5570 The slit experiment doesn't collapse the wave, otherwise we'd never see interference.
I'm sure there are other ways of checking if the wave has collapsed which don't need such a complex setup.
The experiment itself isn't difficult, but isolating it from all other particles is quite the challenge.
I'm hoping someone with more knowledge stops by so we'll know how the idea doesn't work. Or if we can go pick up our cheque.
As someone famously once said, you got to play the cards that life feels you sometimes you win sometimes they lose but at least you're in the game
I literally asked myself this question the very first time i heard of quantum entanglement
Thanks for this video
Cool to see 'ansible' mentioned, as it's the first thing that came to mind when I saw this video title! I came across the concept of an ansible (device for FTL communication) in the Ender's Game series, but it was an homage to Le Guin's work.
I always feel like I'm transcending somewhere when watching these videos, completely mind blown and just don't want them to end. Defo gonna grab one of those t-shirts one day! Keep up the amazing work!!!
Agree *xxxjamxxx* . By the way. I have 2 of the shirts.
Time for more mind blowing: Since FTL Comms can't happen, that means not even a solar system wide civ would be able to have a decent timed communication system since even communicating to Mars would require 7 mins per message (avg)
Edit: Even the moon would take a whole 1.3 secs...
Get it get it, you know… Hennything IS Possible!
I already have a cool worlds hoodie and a mug, well worth it to remind myself to stay thoughtful and curious (and they actually look great) 😀
@@firestarter923 Nice! Plus if you're wearing it out and someone clocks it, you just know they're going to be cool!
Can the state not be stopped and started again? Wouldn't it be possible to stop and start a spin at a fast pace and record every position change as a decimal to be converted to hexadecimal for text based ftl communication? Like Morse code
Thank you for another great video brother
Makes me think of the measurement problem. Everything that’s going on in double split before the electron hits the screen, where the measurement of the position actually takes place, the wave seems to collapse. It chooses a position to narrow itself down to. The act of measuring the wave changes the wave.
In the interference pattern of the double split, we know the collapse is not random. The electron is very likely to be where the wave is strong and unlikely to be where it is weak.
There seems to be a correlated anomaly that we haven’t fully grasped yet. I hold out hope for additional breakthroughs in the future.
energy is everywhere all at once. light is energy. to attempt to grasp an infinitely small moment of light is futile (see; achilles and the tortoise). however, we perceive an infinitely small moment of time at any given time. this is only human perception. the light is always there. the patterns are always there.
It's double slit not split.
This is something I've pondered ever since I learned about quantum entanglement. I've spent many nights thinking about the ways it may or may not work. I'm really glad you touched on this topic and I can't wait to see what your take is on it!
Wait, in this thought experiment, how would Alice know WHEN to LOOK at her particle? I thought the mere act of “looking” at a particle would make it collapse into a given state, no? Assuming Bob can somehow control the state of his particle before he measures it, Alice wouldn’t have a way to know when Bob has measured it because she would have to be “looking” at her particle waiting for Bob’s signal… but the moment she “looks” at her particle, it would collapse into a state because she looked at it, no? What am I missing? Are we assuming that the particle would be inside some machine that can detect when it has collapsed into a state without actually measuring it?
You can solve that problem by just having a set time to check the particle, knowing like 3 seconds prior bob interacted then Alice just has to check at the specified time to see the message, if there is any. I think at least.
Great question and great answer
Thank you, your question has helped me in my figuring as to how and why ftl commo is indeed possible
@@spody1005 but based on this thought experiment, ftl communication is actually not possible, right?
@@jc_alpha it's not possible at the moment because noone has applied the methods that seem to imply that it is possible. You touched on an important issue when you asked about the particle collapse. We don't need to control the particles state. I see it like this, instead of trying to send a message by determining the spin of a particle, imagine if we only looked for the collapse itself. Whenever a pair was observed, the collapse into a given state could correlate with a true/false signal. Like binary code or like a Morse signal controlled and timed very precisely , we could develop a system that deciphers a message based the observation of whether an entangled pair has collapsed or not into a given state. O's and 1's, true or false. All the physicists seen to be focusing the randomness of the spin outcome. I don't think the orientation of the particle is what's important here.
would it matter if instead of A:B = 50:50 we had other bernouli distribution i.e. A:B = 60:40, could receiver in such case observe reversed distribution i.e. A:B = 40:60(when transmitter did a series of measurements)?
After listening to a lecture by Alain Aspect two weeks ago, I've decided to attack the subject with the book "Introduction to Quantum Mechanics" by David J Griffiths and Darrell F. Schroeter, it's pure food for the brain. Your video couldn't be more on target with the topic. As usual, very interesting and clear with a great sound quality and beautiful video editing. 👍
That book is pretty great it seems. Do you know the maths?
I thought that we can dictate which spin we want the particle to be in, and that is how Quantum Computing works. Now I need to revisit that again.
@JAGDISH TEMKAR
We can control the spin of particles, for example electrons, but then we get bits, and not qubits. So not quantum computing, just computing.
The trick with quantum computing is to compute with bits in superimposed states, i.e., Qubits, until we read out the result at the end.
@@larsnystrom6698but if you can force spin-states, as a bit, why can’t quantum entanglement work to send bits of information?
@@WRanger87send it how though?
I think a fun way to describe Schroedinger's Cat (which always confused me as a child) in comparison to Quantum Theory is not necessarily that the cat is both dead/alive until we develop a point of reference, but what occurs based on our lack of knowledge.
If Schroedinger went about town & told everyone his cat was alive, & bought a bunch of cat toys & treats, he would be functioning as if the cat were alive & changing the universe (utilizing communication to affect society & money to affect the marketplace) to develop a space for the cat. Therefore, the cat is "alive".
If Schroedinger decided the cat was DEAD, & lamented to friends & famoly that the cat was dead, & threw away all his cat food & never spoke of it again, the cat is DEAD (or will be soon unless he treats the cat as if it's alive again). This is "Spooky Action at a Distance," aka Quantum Entanglement.
In humanity's search to find an absolute, pure unit of time to compare against, we have forgotten that our unique experience as a human race is its own measure of time. Our frame rate of perception is Quantum Entanglement At A Distance (I hate Einstein's Name)
The problem with this discussion is a lack of understanding about serial communications. One requires 2 entangled lines. The 1st line generates a phase transition that functions as a timing pulse. The 2nd line represents data and is referenced to the timing pulse. The only thing required for data is a transition which can be either a 1 or 0. All that matters is that the transition occurs when compared to the timing pair. The pairs are entangled but not with each other.
Thank you, this is something which has been bugging me a lot in sci-fi. Entangled particles are like having two pieces of candy that look the same, one is sweet and one is sour. Then you give one to a friend and he travels to the other side of the planet. If you eat your candy you'll know what flavor you got, and what flavor your friend received. But it really does you no good other than that. If you want to talk to your friend and ask him if he liked his candy you still have to use your phone. And obviously you can't change the flavor of the other candy by doing anything to your own candy.
You are right - the problem is that the mystic far distance influence was "proven" with Bells inequality. But this inequality is based on set theory. But every measurement is an energy transfer. And for this vector equations must be used with basic electrical formulas. And then you will get the right answer, even if you assume the two are paired in the beginning of the experiment - not only at measurement time.
What if you had prior information that your friend doesn’t like sour candy and both agreed to eat the candy no matter what, wouldn’t that be reliable information?
@@mohamedaminehenchir297 -- Still doesn't communicate anything new between each end of the entanglement, unfortunately
What if one candy is deadly and the other candy not. The result of quantum entanglement will still be a 0 or 1 when measured. I think there is very viable information in that case. So then you could say: After eating the candy you must do the same candy experiment with your neighbour.
That means if we measure if person A is still alive the neighbour of person B does not know anything about a candy. So giving extra tags to a case before measuring will create a lot of good information.
K, but what if you had a bag of quadrillions of pieces of sweet and sour candy and you ate them on your end in a very specific order to communicate a binary code?
When you've started laying out examples I was hoping for mass effect. Thanks, nailed it.
Also, thanks for the video, not long into it yet, but I was looking forward for something like this for years I think at this point.
Absolutely brilliant. Thank you!
Best explanation of this topic I've heard, thank you.
Not only that, your final thought went beyond the science and was just a great lesson for life as a whole.
Great job 👊🏿
This is exactly why I Proclaim that we have never been visited by other life forms, they have the exact same problem that we do, the vast distances and the slow speed of light prevents any survivability to make it from point A to B.
When referring to light, you probably mean transverse light, or transverse EM waves.
Longitudinal EM waves propagate at practically infinite speed. It's just that they are much fainter, so very hard to pick up, and in the development of radio communication since its inception, everyone just assumed longitudinal EM waves didn't exist.
They do, but it takes a spherical antenna for transmitting, and very sensitive equipment AND a spherical antenna, for receiving.
@silvergreylion Give me one reference for what you stated. I really mean this. I'll go read it as soon as you post.
You're saying speed of light (longitudinal) in a vacuum is much faster (infinitely). Correct?
@@pereirahawk This is currently being researched.
The research hasn't been published yet, but the speed would be the reciprocal of the Planck constant, so ~1.5x10^33 m/s.
@@silvergreylion I'm currently researching how to turn my hot tub into a time machine. I haven't published anything yet though, so you'll just have to trust me when I say it's totally legit.
We are apes, one foot out of the trees. Yet we have, OURSELVES, proven theoretically the reality of wormholes. Why is it so hard for not so smart individuals to believe that in a universe with COUNTLESS planets able to support life, there would be one (or one million for that matter) life form that figured out how to use the Einstein/Rosen bridge wormholes practically? The arrogance of some simple minds to think that we "apes" are the pinnacle of intelligence in the universe is hilarious. New discoveries in physics happen every day. Smh.
What if you put a set of entangled particles into a a time-synchronized queue on each side (where a pair is used once and only once at a specific time) and you only measure whether or not the particle has been measured?
It seems to me that the fact that something has been measured constitutes information in an information-theory sense. We might not be able to get information from specific state attributes of an entangled pair, but we can, if I’m understanding this correctly, at least tell if it’s been measured.
So, to reiterate: we entangle a bunch of pairs; these pairs are allocated to a specific slot in a queue. The queues on each end are very precisely synchronized. When the time comes for that slot, the transmitter either forces a wave function collapse or it doesn’t. The measuring side, looking at the same slot at the same time takes an observation. If it’s collapsed, then we know something happened, which could symbolically constitute whatever we want (a heartbeat from the ship, for instance).
After the slot is consumed, the pairs are discarded.
I’m sure there’s holes in this idea, but it doesn’t seem to have any at first glances. Rebuttals are welcome.
When you're checking if the particle has collapsed, you're actually measuring it, there's no way around. So you would see a collapsed state every time, if it has collapsed before your observation or not is impossible to know.
This has got to be one of the very best explanations of quantum entanglement I've ever seen posted on TH-cam. Thank you. The important take-away here is that entanglement is non-local - but even so - it does not violate causality. But why is it non-local? I think one area that needs more theoretical exploration is the idea that spacetime itself is quantized. If we imagine spacetime as quantized - it means spacetime particles (or whatever one wants to call them) can exist in superposition, and that means spacetime particles may exist as entangled pairs. So it may be the case that a pair of entangled electrons, derive their non-local status, because they exist within the same particle or envelope of entangled spacetime. The idea worth exploring is that there may be other dimensions that we do not observe directly due to the quantum nature of spacetime, and as such, what appears to us as non-local effects that happen faster than the speed of light - are actually demonstrating to us that spacetime itself, is entangled. And perhaps the spacetime entanglement involves more dimensions than we can directly see. So in this model of spacetime, "Spooky action at a distance," is not really happening at a distance. Instead, the effect is happening within the confines of entangled spacetime. What appears to us an instantaneous communication between a pair of entangled electrons that are far apart - is actually happening in the same region of space - that is an envelope of entangled spacetime. Entangled spacetime, if it exists, could have enormous implications for all of physics - and may even, propel physics to a new foundational understanding of the universe. Please think about quantized spacetime, and its close cousin, quantized gravity, as a promising new direction for physics. Some thought experiments are needed to complete this picture. Please carry on.
Wish I had you as a lecturer at University, your ability to communicate and break down extreme complexity into simplified terminology, then bring us(the viewer) back up to the level of understanding through step by step learning to give us understanding of such complexity is brilliant..(I hope that even made sense) No offence to the seriously intelligent people out there with in their specialised fields, but not every PHD, Dr, or Prof can communicate with the masses.. At university I was told by a Doctor of Chemistry that "a Dr knows a heck of alot about very little". 😊 it took me a moment to realise how true that statement was.
haha......"a Dr knows a heck of alot about very little". Great quote
You have to truly understand something in order to explain it.
There's a mark Twain quote.
"An expert is just some guy from out of town"
"Wish I had you as a lecturer at University," me too, but unfortunately, you can't put lecturer at 1.75x playback speed.
Two things come to mind.
1. Deeper research into understanding how to detect if a particle is entangled or not … if this can be solved we’d have a way to communicate FTL.
2. Entangled Particles are obviously communicating somehow, digging into the how could be the medium we use for FTL communication
Cannot detect whether one is entangled. And the first measurement breaks entanglement.
It is not obvious at all that they are communicating. In fact its fairly obvious they are not.
2. How is it so obvious?
In my opinion it's much more convincing they share some kind of information but we just don't know how exactly yet.
Bell-Inequalityl is targeting determinable particle behavior but those quantum objects aren't just particles. They are more like waves which have to be described with complex matrices.
@@Merilix2 Not waves, but one wave. Being entangled means they share a single wave function. That single wave contains two particles worth of information in the possible selections of (up/down) and (down/up). When one particle is measured it collapses that single wave function for both. They do not need to communicate. They have no choice but be opposite as there is no (up/up) or (down/down) possibility to randomly measure.
@@wesjohnson6833 Well, the one wave function you are talking about is just a probabilistic math model. This wave function does what every function about probabilities have to do if you get measured results. The model collapses from uncertainty into (partial) certainty. In my opinion its just misleading layman's if the word "collapse" is used like something really happens remotely at that moment.
I think, entanglement is about the contrast between uncertain principle and conservation laws.
I'm pretty sure, the Copenhagen interpretation as good as it really is is not the end of the story yet.
@@Merilix2 I agree about Copenhagen. Not advocating that as gospel.
Of course the wave function is a model. Some argue it is physically real (like many worlds advocates), but even if s bookkeeping device, it does seems to model something physically real. "Collapse" is another term we use for lack of a better term or model. With caveats I think we can use them meaningfully.
That said, it is true that only one wave function is needed to completely describe the entire system. And there is no uncertainty about the system, just the parts. They are entirely random which is a necessity for a maximally entangled system.
I just noticed reading through the thread that you were replying to the initial comment and not mine. lol. Oh well, sorry 'bout that.
As someone who has a background in Physics, I always went along with the accepted point that the randomness within a quantum entangled system prevents FTL communications. I recently read a book 'Cracking the Cosmic Code' which actually shows that the randomness is not a restriction at all. It now opens up the distinct possibilities of FTL communications.
In all versions of quantum communication attempts you mentioned I have not seen one which takes a similar approach to the quantum computing approach. Quantum computing is limited in what it can compute, because it uses convoluted methods to arrive at results. I still believe that there are convoluted structures of entangled quanta, which allow for FTL communication... It just needs an engineering approach. I'll try and tackle this one when I do my doctorate. 😉
Good luck mate
We are rooting for you. Hope you'll get to pursue your dreams.
As a layman. If you can entangle something which we confirmed already then we definitely will work out how to use it for FTL. Communication. It might start out simple as a telegraph before working it up to computers talking. But here's a thought if you established a real time link. But time is passing differently I assume the communications couldn't speed up or slow down at their respective locations
@@Shep01 The kicker is, there is no new information being transmitted. You simply also have information about the other part of the system, because it's complementary in a way (if my coin says heads, I know you got tails). We would have to meet again and make another entanglement then travel very far from each other again to "communicate" further, but this is not FTL at any point. Once you look to see if you get heads or tails, the two systems untangle go through decoherence.
I am Quantum 😂 Pleaseee helppp meee. Bassem....I fucking sent myself to be birth in this day and age...get me off this planet of aliens haha...No one is probing me anytime soon
Such a thought-provoking video. Thank you. Keep up the great work.
This is the answer I hoped from you.
As a person who failed at physics I can't do anything but silently watch physicists and the other people discuss the formula and interpret it. My question is always
"How can you define a useful communication while neither of you know it or not needing to know it the first place since it breaks the moment either of you measure it and the opposite of you not knowing it breaks yet which is simply "sending information without knowing that information from the first place". How can you have a good communication while neither of your observations needed?"
And this might be rooted from my ignorance since I don't know physics and your explanation corrects all of my misconceptions of that although I have the shared answer that is a solid no, or at least not enough. The difference is that my argument is filled with misconceptions and ignorance while you have valid reasons.
y yoo😮😮ooy
Nah, you're correct, or very close anyhow.. Schrödinger's cat, sort of ...IS an observation required? Entanglement is, specifically, Feynman diagrams. Two-slit, as I'm sure it referenced. Amazing stuff. 👍
So if we measure a bit can we force it into up or down?that's my understanding. If so if I want to force it down what happens when the other detector tries to force it down but it has already resolved to up? To me the approach would be finding out when a bit was resolved. For instance if you have a huge array of bits 256 x a million. If I continue to readthe first 128 bits and force them down and that works then I am first to read them, but if they are up(pre agreed configuration) then I know there is a message in the second 128 bits. I understand that relativistic travel would mess with time frames but you could build a method for syncing the "now" element with the above method.
But you can affect the state in a timed manner essentially sending state changes in timed sequence- this way it dosen't matter what they observe they just have to observe the changes and measure the time between.
Thank you for all this content. I agree with others, you are truly inquisitive, accessible, willing to admit when we Don't Know, or even more importantly, willing to question what we think we know! 🙏🏼
Now I understand, always thought you could force a spin, but that was cleared up, thanks!
How about this model from a senders perspective:
First pair is used for bits.
Second pair as "Switch" or Send button.
Measure the first one as long as u get the desired outcome (0 or 1).
Then measure the second one until it changes spin compared to its prior state.
The receiving end will know to only read that one bit in the information string, that was measured prior to the "switch".
The "switch" does not care about direction of the spin, just the change itself.
Or no?
Thank you bye
Than you for this video, it was what i looking for
Amazingly explained. Thank you for all your efforts
I always look forward to your new content.
Thank you for your hard work with all these videos. Best science content on TH-cam
By my understanding, unless I am somehow mistaken, particles can be entangled with more then one other particle.
Which leaves me to wonder, if one particle is entangled with several others and you disentangle one particle by observation, what about all the other entanglements with the other particles? does just the one disentangle or do they all become disentangled together? and what if you observe more then one entangled particle at the same time out of the grouping?
Here's an idea, why not assign characters to time? hear me out, Alice and Bob both have their entangled particles and if bob wants to send a message then bob times the activation of the particles and Alice measures the time between each activation of a particle. If "H" equaled 1 second and "I" equaled 2 seconds then Bob would activate a particle, wait 1 second, activate another, wait 2 seconds then activate another creating two segments of time representing "H" and "I" between three points. Theoretically Alice would measure these time segments and attach them to the correlating characters deciphering the message "HI." its essentially cosmic Morse code
But how would she know if he has activated any of the particles?
This is really well done, you guys. Great work.
At the beginning you alluded to communications between distant outposts of an interstellar species. This is something I've been wondering about a lot lately and would love to see you discuss it at some point. The main thing I struggle with is the assumption that we would communicate with humans who set out to settle an extrasolar planet. I mean, would we actually? At some distance, the latency would make it almost pointless, right? What sort of information would we share with a colony a light-year away? 10 light-years? 100? It's natural to assume we'd have communications, but when I actually stop to think about it, I'm not so sure anymore.
Taxes bro. All we need to do is set up a colony and the IRS will figure out the FTL communication problem in no time.
As far as the nature of a conversation is concerned, listening, processing, responding. The delay would severely limit what could be communicated in that sense. Nevertheless I would imagine the basis of communication between distant colonies would consist of a constant two-way stream of art, media, and scientific knowledge. The expectation wouldn't be the recipient colony would respond and convey something meaningful, rather that all parties would continue sharing their culture and information.
If we would do this one day and the rules of physics we know today still apply, I would guess there would be multiple different species of humans at some point as we'd evolve differently depending where we are.
Communication with other human "species" would be more of a fun thing to do, but wouldnt hold too much purpose at this point.
There is no speed limit on communication. It is a myth perpetrated on purpose of keeping this world "in the dark" aka. not known by alien civilizations. (Type 2 civilizations and higher don't communicate on RF spectrum) If there is widespread belief in there being a limit, nobody/few will research possibilities past it. I personally worked on Special Access Projects, so I know this for a fact.
The conversations would be highly relevant if we also had FTL drive to get us to those planets in a non-ridiculous amount of time.
Using rockets or generation ships? Forget it.
Star Wars or Star Trek? Now you're talking.
Really awesome video! Really easy to follow and understand, even though the concepts are advanced. I do realize that most things might be and "over simplifications" when talking about quantum physics etc, but it did give a bunch of "aha"-moments. It's very appreciated!
It's definitely a nice video. I don't necessarily agree the assertions, but fun to watch nonetheless. Also If your still murky on any of the concepts, feel free to ask. If I notice the comment I'll answer. Not sure I'd consider myself an 'expert' but I've always loved stuff relating to Quantum mechanics and/or Theoretical mechanics with practical applications. ^.^
Awesome to include video games and other shows. Helps put it into perspective for the amateur enthusiast
Quick correction, 10000 years ago is 3000 years after the Göbekli Tepe structure was errected in Turkey. So, yes, 10K years ago we had no already left africa, but we also had already begun creating fixed settlements, agriculture and, well, culture in general
I’m shocked I haven’t found your channel sooner. It’s quickly become my favorite space channel on YT.
It's pure trash... why are you so happy to find it?
@@skizmo1905 ok 👍 why do you think it’s trash?
I could not put up with the annoying background noise.
@@savage22bolt32 I didn’t notice I’ll have to see for myself
@@Brendy733 i thought the subject matter would be interesting, but the music killed me.
This was a very inspiring video! keep up the good work!
Simplest experiment to test whether quantum entanglement allows for FTL communication:
1. Position two QE communication modules at the base pair of angles (A and A') of a large (miles) Isosceles triangle of sides with lengths a, a and base length of b.
2. Have A transmit a signal to A'. Then, have A' transmit a signal to A.
3. The moment A sends the signal, have it also send a signal to B. Ditto for A'.
4. The moment A' receives it, have it also send a signal to B. Ditto for A.
5. Repeat 2 through 4 many times in order to generating timing data with enough samples for critical study.
6. Repeat 2 through 5 with varying lengths of b, from 0 (next to one another) to several times a.
7. Throughout, note the location, orientation with respect to Earth, Earth's rotation and movement through the solar system and galaxy, etc.
In so doing, you will generate all the data required to definitively ascertain signal reception, processing and sending time, in order to determine whether A to B signal is indeed transmitting information FTL.
Bonus: The two a side lengths need not be exact, as you're working in both A >>> A' and A' >>> A directions. The repetitions will allow you to ascertain and discount the difference.
Random thoughts from a non-physicist, which have undoubtedly been discussed and thrown out already:
If, after measurement, the position of particles can be determined by both parties, and the timing of measurements can be controlled by our fancy QEC...
What if we ignore the actual position, and only focus on A) timing and B) when the same position occurs multiple times in a row?
Bob starts measuring, say one particle every millisecond. If a _zero_ bit is required for the message, as soon as three (for example) of the same spin are detected in a row, the machine introduces a pause in the measurements (say 5 milliseconds). If the communication is instant, shouldn't Alice see that pause? If a _one_ bit is required, Bob would _not_ pause after three in a row. A pause after five (or whatever) in a row indicates a one bit.
Very nice video as always Cool Worlds. I really enjoyed that many scenarios were explored and references to how some of these promising concepts were embraced by popular science fiction as a plausible solution for communication across vast distances.
Something to understand about the current state of quantum mechanics is that the act of measuring is never passive and becomes deterministic of the answer we will get. In most other domains of science our measuring tools manage to have a minimalistic impact on what is being observed. But in the context of quantic mechanics there is no sight, what we try to measure is so small and the way of measuring is throwing particles against the particles we are trying to observe to see how they bounce off.
Perhaps everything will be reconsidered if we find a technology to measure the quantum states without as much interference. I'm already impressed that through statistics of infinitely repeated experiences the quantum mechanics science is able to establish causality when every observation is destructive and deterministic of the state being observed.
I find it interesting to think that anything FTL could however break causality. If we used a theoretical wormhole to send a mere Lightspeed communication through a distortion of the spacetime elevation map, would that be breaking causality ?
The speed of light appears to be in a way the speed of time. Riding a photon, one wouldn't experience time at all. Any particle without mass also seems to be traveling at this speed, and so do gravitational waves. Electromagnetic waves are slightly slower than the speed of light.
It seems like a possibility that the perception of time could be an emerging property of the interaction with the Higgs field. That anything with a mass is dragged through the ever expanding time dimension and able to perceive it, perhaps akin in the same way that gravity holds galaxies together in an otherwise ever expanding spatial universe. Could dark energy be expanding all of spacetime and our perception of time be a mere side effect of gravity on spacetime?
Well, yes and no. Make a guess and you're correct.
I love the entire breakdown. Continuing with "mass dragged.."
One thing to remember, always, is that we are made of the same crap we see when we look out 'there' in space. We are designed adjacent to the circumstances of our environment: Our genetic code is adaptive due to climate changes, our forms are a collection of atomic-scale fusions, cellular formations, and biochemical reactions. Systems within systems, like a galaxy itself.
We are finding that the fundamental substrata of our universe of probabilistic. Maybe its a gigantic mind, and we are part of a gigantic, cosmic neural network? Being so aware of the system that we can modify and adapt it utilizing the same sentience that makes it up? ;) After all, what we are to a human brain would be somewhere in the center of the nucleus of an atom in a neuron..
That was off-topic. What I was getting at is that we only observe the universe at a rate we were DESIGNED to. Universal time dilation is totally subject to the framework of the observer. In this case, average humanity. That observation has 2 obvious possibilities: That what we see is all there is and is subject to external events involving light (which can shock the observer's system when what we see does not align with our contuinity of events from a personal framework), or what we see is defined by what we expect to see. This latter idea is vain, and points towards man's egotistical idea that we are somehow separate from the energy we are made of; essentially, god beings. At least, simplified, this is how I interpret it. FTL is possible in theory because existence just is. We are the instruments ill-equipped to be somewhere else from 1 moment to the next. Its a material limitation of our very design.
We already have a way of measuring the quantum state without interference. It's called "delayed choice quantum eraser". Check it out. This experiment proves that it's the act of observation, or at least the information about a particle becoming available to the universe that collapses the wave function. An entangled particle somehow "knows" that its partner will be measured in the future and collapses its wave function retroactively. So the interaction during observation would have to break causality for the non-measured particle to "know" that its entangled partner will be measured in the future.
David, I can't get enough of your channel. This was one of your best topics. At this rate, you are going to hit 1 million subscribers in no time. Thanks for the great insight into nature and the cosmos.
Thanks so much! This episode took a lot of work so pleased you enjoyed!
@@CoolWorldsLab I had also asked about this topic/possibility after your previous video. Thank you very much for providing such an excellent explanation! Love your channel, thank you for all the hard work!
Is it possible to continuously observe the quantum spin state of an entangled particle? And if so, is the spin state constantly changing or is that spin state at rest? I’m assuming that constantly observing (or measuring) the spin state would show that the spin state is always constantly and randomly changing.
The moment you begin to observe it it will enter one spin state. It is in superposition before it is observed.
Is their a quantum particle that affects some aspect of its environment based on its state without changing its state? Or something that effects it’s environment when it’s state changes? Such as a particle that causes a wave/ bend in space time as when it changes state, or emits a photon?
Another incredibly thought provoking video, thank you so much David for the time you put into them. I believe in miracles and I believe our seemly mundane every day existence is the miracle
We may not have found a FTL communication (yet), but we did find a truly random number generator, i would say!
My half-elf is clapping with joy
I thought old defect ram chips would already do that.
I like the thought you had towards the end which is that:
in the coming centuries we may not get anywhere close to FTL travel or communication,
but we will need to ACCEPT that FTL may be impossible and find ways to overcome that...
for instance, for the colonization of mars it places a great importance on self-sustainability and understanding supply+demand and preventing overpopulation
Fuck mars, embrace the moon
I feel stoned watching these
Maybe you are. 😊
i *am* stoned watching these
Thanks for this great video, going through the most common misconceptions about quantum entanglement, which to the best of my knowledge should be described as a peculiar type of correlation (just as with the shoes). So most importantly: opening the shoe boxes does not constitute an action where my opening the container affects the other box. I think, your final summary would have been an excellent opportunity to glance at the measurement problem for a future video. The Schrödinger equation, as well as the Dirac equation or any other QFT, does not contain the wave function collapse. It is an ad hoc postulate that might need resolving to better understand quantum physics and anything that might await beyond.
One reason I find so many Cool Worlds videos (including this one) so rewarding is that they conclude with a CONNECTION. A connection to human concerns, far afield from the original topic or even from science.
I know that some will argue that "that's not science!" That this is opening the door to pseudoscience, to New Age woo-woo and so on. That science stops when pure logic and evidence stops, and should not keep walking into "speculation". And they're right that it's not science - but I believe wrong about the implications.
I don't believe Prof. Kipping would claim to have shown any science-verified conclusions about these human concerns. These connections are not saying "science tells us the 'answer' to this ancient moral dilemma". Rather, the science is providing us with a new point from which to VIEW that dilemma. It's not an answer, but a tool. Perhaps from this new perspective we can reach our own conclusion with greater confidence, satisfaction, or even richness - but it remains OUR conclusion, not that of science.
This is absolutely very well expressed! It’s also a science that seems without end
Watching 3 body problem and it reminded me of this video. Saw this video a while ago and i finally found it😂 I understand not a single bit of this but still find it very interesting.
I mean I came here for a video about quantum entanglement and I left with some damn good life advice....bravo
I loved this! You brilliantly cover a very heavy physics topic in such a way that makes it relatable and clear! I like that it’s a new idea for the channel yet also cleverly ties into previous videos. An idea for an upcoming video, maybe you can touch on how particles become entangled to begin with. It’s rarely covered in videos on other channels. Maybe bring it up when discussing the current record holders for distance between entangled pairs. 👍
It’s incredibly simple to produce entanglement between 2 particles, etc. One simply has to interact with it, that’s all. Literally ANY and all forms of interaction will produce entanglement. If a photon lands on your retina, that’s producing entanglement. Or if you feel warmth (kind of hard not to, if you’re alive. Lol) you’re absorbing/interacting with billions of photons per second, entangling said photons with whatever particle of your body absorbs them. That’s all there is to it.
@@aaronperelmuter8433 I read somewhere that the probability of an entangled pair resulting in true opposite measurement goes down the further they are apart. Is this something you have heard about? Thank you for the reply btw 🙌
@@stephanieparker1250 No probs, you’re very welcome. Ttbomk, there is no known correlation between distances of any size, small or large and the reliability of entanglement. Also, it’s purely an arbitrary choice as to whether one wants the spins opposing or matching. Come to think of it, quantum theory doesn’t really have any use of distance in an abstract form. Sure, interactions only take place when within a certain distance, e.g. strong force within about the diameter of a nucleus, etc, but when something is entangled with something else they can no longer be thought of as seperate objects. The very definition of entanglement is that all entangled objects are the object, the wave function is now describing all entangled objects, not a seperate wave function for each object. This is precisely why entanglement is so fast (instantaneous? I think not but how fast, I’ve no idea) as when an operation is performed on one of the objects, it (immediately) propagates the fact that an operation was performed to the rest of itself. It isn’t like if you touch your elbow and feel it immediately but touch your hand and it takes a few seconds to feel as it’s further away. In a manner of speaking, a person is one entangled system so when an update happens, no matter where it happens on your body, you feel it instantly. Entanglement can be thought of in a similar fashion. One can entangle any number of objects, but they will not be maximally entangled if there are more than 2 objects in the entangled system.
Regarding what I wrote previously, I’ve a small correction; I don’t know that it’s possible to entangle a photon with a matter particle because I can’t think of any interaction which doesn’t result in the photon being absorbed by the matter particle (electron, neutron, etc. absorbs photon and gains energy of the photon but now said photon no longer actually exists. And since there is obviously no possible way to identify one photon from another, when the matter later emits a photon, losing energy, is it the same photon or actually a new one? I think it’s the latter. So, I don’t know any reason why dissimilar particles couldn’t be entangled, if they share the necessary quantum property, so a neutron should be able to be entangled with a proton, an electron and a neutrino, I think. I’m just gonna go out on a limb and say matter can only be entangled with matter and radiation with radiation. Also, reasonably sure their spins have to be of the same order, as in spin 1/2 or spin 1 but not mixed. Although, that’s actually the same as what I said a moment ago, matter with matter…
Hope that’s of some help.
@@aaronperelmuter8433 it does help :) thanks!
"Open subspace frequencies" Something a lot of us heard in Sci Fi shows and movies.... they've had an idea about this kind of stuff in the 60s but lacked the technology to actually test for it or attempt creating it. It's not a question of "is it possible" the question is "how do we do it". Quantum particles (particles that can exist in two places at the same time) they seem to also have another characteristics, one being that it can "slip" into and out of some sort of void, a "subspace" that scientist can't fully understand or explain yet.
We don't understand anything. We just measure stuff, get results and pray that our macrocosmos-based methodologies & tools are reliable in the world of quantum mechanics. At this point in time, all the "explanations" are just wild speculations, interpretations, philosophy, expressed by the limited human mind/ human imagination/ human language. When you say "particles can exist in two places at the same time" I assume you are refering to the "superposition-principle" which describes a mixed state of being. Being a particle and a wave at the same
It's somehow related to the multiverse, because it does make sense that you cannot communicate FTL. It means one particle exists in another universe. Basically, the communication will be between two different universes. Thus it won't make sense to the other universe hence producing random results.
So it may be feasible to establish a faster than light entanglement link between Planet A & Exoplanet B, but the only problem is we can't use such a link to send realtime data (relative to each location) between A & B. We shall have to find a piggy-back proton that can facilitate this ?
What if i measure 5 particles, on the receiving side up would mean yes. since its 50/50 on the receiving side we will get for example: up up down up down. but then we will use double slit experiment to verify the message. Since we cant force the message into saying yes or no, we could just say if the message is true or not by using a particles that would be measured only in case the message is false. the receiving side will use double slit experiment to see if the particles were interacted with or not. So if the particles would still be in super position that would mean the message is true. Also, each set of entangled particles would be assignet to different message for example: Habbitable planet? (yes/no), ship in danger? (yes/no). Only problem is to make the receiving side look at the particles at the right time, also the combination of messages would be really limited.
Excellent video.
Clear and concise explanations.
So much progress to be made, so much still left to know and wonder about. Keep up the great videos
How about this idea: What if we consider 1 = the time between the measurement of two particles is higher than 0.5 sec and 0 = if the measurement happens lower than 0.5 sec apart (or anything that can be agreed upon, like faster or slower than the vibration of a crystal). In this case you don't really care at all about the actual state of the particles but the speed at which they are being revealed. You would have to detect on the other side the particles that are collapsing at a particular rate (more or less than 0.5 sec) to figure out whether what''s being transferred is a "0" or "1". Would that be workable for a FTL communication device?
Bruh i just typed out a whole comment and its the exact same idea, at the end though i said something that might make our theory unfeasible, ill just post my comment under here: could time not be used to indicate a message, like not looking at the position of the spin but the time between changes in spin, its a super rudementary idea cause its not thought out, but imagine the first spin being a sign of start and the second change in spin meaning stop, lets say a 0.1 sec time in-between is 1 and 0.2 is a 0 (maybe 0.00 for 0 but idk about that), --> I was thinking while writing this if that's even possible, cause if you want to measure time you have to observe the particle, possibly forcing it into a state (this inherently would pose a problem to all forms of measurement as you wont know when you can measure without interferring with the spin state
Basically it's like the Morse code, but I think the problem here is that you can't know at which moment the particle's spin was changed
That is what I was thinking, except you have two particles. If you collapse only 1 it's a yes, collapse both, it's a no.
That got me thinking, it says they will collapse instantly, but what if Bob is moving at near relativistic speeds and Alice is stationary (relativly) so Bob is in a different time then Alice, what does it mean to collapse instantly. Bob could be in the future relative to Alice. When he collapses his, does hers collapse instantly even though she is in the past?
@@jonnyjonjon333 They are both in the future but for the one traveling at a higher speed time is passing slower than to the one stationary. The collapse is instantaneous to both sides, whichever time they are. But yeah, your idea could also work I think if particles could be grouped in pairs. My guess is that they could make a workable FTL device with any of those ideas.
@@KamilDeKerel Yeah, I guess the whole idea is based on the ability of the observer to detect collapses of the wave function in an array of entangled particles, and be able to compare the time in between those collapses to something that can be in sync with what the initial sender compared them to. Let's take for example the vibration of quartz crystals (32,768 vibrations per second), but time slows down if the receptor is traveling at a much faster speed than the sender so things can get complicated in that case. The other option would be to arrange them in pairs like what @jonnyjonjon333 suggested: This way you have two arrays of entangled particles at both sender and receptor. Each particle of the first array is paired with one other particle in the second array. This way if you detect a collapse in the particle of the first array but its correspondent particle in the second array doesnt collapse before the other particle in the first array collapses then its a 0. If the two paired particles in both arrays collapse then its a 1. This eliminates the need of a time comparison.
It seems like the easiest way around the communicating problem would be to use the time between observations as representing letters. Have 3 observations of the same length of time to start a message then the distance between the observations would be the letters. Ex. .001 nano sec. For A .002 for B and so on. Or even easier .001 is 1 and .002 is 0. And the observation times become your binary system no need to rewrite codes. Doesn't matter if the spin is up or down. Just the differences between observations. Just a thought.
that is exactly what i thought, use time and go morse with it.
Neither Bob nor Alice know if there has been a measurement or not? How bob could have collapsed 1 or he could have collapsed 1000 Alice doesn't know either way?
If they gave out Emmys for TH-cam videos your house would be full
Thank you for your videos. You have a way to engage and make my brain hurt in the first 9/10ths of your videos, then engage and make my heart hurt (in a good way) the last 10%.
Thanks for the headache! First time I’ve understood that we can’t influence the spin
I wonder if pre establishing the timing used between particle interaction/transmission could be used variably to represent the alphabet and thus messages could then be sent ?
I read a lot of science fiction. When I was younger, I naively believed that quantum entanglement truly could make FTL communications possible. But as I've learned more about quantum mechanics and how things actually happen, I became increasingly skeptical of the idea. The final nail in the coffin of FTL communication for me was learning that you can't observe particles at a distance. It's not like watching a ball roll on a table where you can see how it moves without affecting it. We have to measure particles using light, which (to use my earlier analogy) is like having to poke the ball in order to see which way it is moving. We can determine from the forces on your finger which way the ball was moving, but now that we've measured it, it's moving in an entirely different way.
Great description, thanks
"you can't observe particles at a distance" - interesting... just thinking here: they say in order to move at the speed of light it's mass or information must = 0 ... ok that makes sense to me but what is the entropy of that thing moving at the speed of light then? What I am getting at here is maybe we don't need to "observe" what we already know because our methods of communication are based off patterns and algorithms (special relativity).
What if we use a very small finger and move ist very gentle and fast?
I love what you have said here. I also have begun saying science fiction is really science future. I agree we need to understand the quantifiable data at hand, but that data. can sometimes change as our processes improve. Human ingenuity will always find a way to create the necessary tools for the universe
@@molybdaen11 Doesn't matter. You're relying on the ball to impart some of its momentum onto you so you can feel it. It's not something you can avoid because it's a requirement to make the measurement, you need it to happen.
One solution I've never seen discussed before is if Alice and Bob agree on a schedule, planning in advance which particles would be measured when. By agreeing to a tempo (and maybe having trillions of entangled particles, error correction codes, etc...), they can both know that the particle they're measuring was intentionally set to spin in a certain direction. They downside is they'd be forced to 'burn' their communication particles continuously, whether or not a message needs to be sent, but this would simply be another kind of fuel, something to be replenished when needed.
But how does that transmit information? Whatever Bob does, Alice will either see an up or down spin - Bob can’t affect which one it will be.
@@Scott_Raynor just the timing alone can be the information
@@zachhoy how?
@@zachhoy a pre-arranged timing transmit no information
"they can both know that the particle they're measuring was intentionally set to spin in a certain direction"
No, they can't if the spin is random until measured. You can't pre-determine the spin before the measure, that's precisely the key point. If you could, FTL transmision would be trivial.
Good work bro..!!
Simple solution: Measuring with a pre-defined frequency, say 5 GHz. Then any change in spin at t0 equals 1, no change at t0+1 equals zero and sofort. Requires a lot of entangled particles, but hey, that's what the interns at the lab are there for!
Coming back to understand this concept again.