To clarify: I understand the "detection" at the screen is a different kind than one that might happen at the slits or any other detectors. It was just meant as a segue/transition to the main conclusion of the video: that quantum mechanics is just a model. The way quantum mechanics works doesn't necessarily say _anything_ about the nature of matter/light. If we input some initial conditions and a few interactions, it will give us a result that matches an experiment really well... but only after we do the experiment with a _bunch_ of particles over time. That doesn't mean we can make any judgements _at all_ about what individual particles are doing at any given moment.

@KohuGaly

5 жыл бұрын

I disagree. The detection at the screen is in fact exactly like the detection at the eraser. The only difference is that it is "softer". When photons hit the screen, their position is consistent with both patterns, but each position has different probability for each pattern. Hitting the peak of the "detected" pattern, makes the second photon guaranteed to hit the detector. Hitting the troth of the "detected" pattern, makes the second photon guaranteed to hit the eraser. When the photon hits the screen somewhere in between, the second photon gets some probability of landing either in detector or eraser. The probability is proportional to the "consistency" of the first photon's position on the screen with given outcome.

@adb012

5 жыл бұрын

@@KohuGaly ... Oh, yes? And what if I turn off or remove the detector after the 1st photon hit the screen in the "peak" zone?

@KohuGaly

5 жыл бұрын

​@@adb012 It doesn't matter. The overall pattern on the screen is the same. It is the way it is, because the second photon leaks information into the wild. Whether you actually happen to utilize that leaked information to figure out something about the first photon is irrelevant.

@junkerzn7312

5 жыл бұрын

I actually thought that was the most important insight in the video. It is something most other Q.E. videos don't even mention. There absolutely is an interaction at the screen, and the pattern on the screen, taken alone, is the same either way. So the inference is that the detection at the screen can select for the result at the eraser without having to deal with anything going back in time. It's the simpler explanation of the two. Result at screen selects for the result at the eraser rather than the result at the eraser going back in time and selecting for the result on the screen. I was thinking about the Q.E. experiment all wrong until I watched this video (and I've gone through at least a dozen videos and two papers trying to understand it). I'm really happy you did a video on the quantum eraser. You have a way of explaining things that allows one to home in on the parts that are most important. -Matt

@wavenature3180

5 жыл бұрын

Another excellent physics video. It seems to me and a few others that the only non-hocus-pocus model is the de Broglie/Bohm pilot wave model. Its really too bad de Broglie let his contemporaries talk him out of further study of his insightful realistic model.

I love the “QM is not magic” mantra! Also particles being tiny waves makes a lot more sense than “they’re particle-wave magic hand-wavy particles!”. I’m so tired of being bamboozled by QM and double slits stealing my lunch money. The final part was a bit rushed for me though, I’d love to have the controversy around what’s going on addressed more meticulously maybe in another video.

@garysamuel9521

4 жыл бұрын

dan fg Agree that the end did not clearly explain how the results stated where obtained.

@jurusco

4 жыл бұрын

man the quantum mechanics was not magic until the end when "models don't explain everything perfectly" soooo....... magic?

@altrag

4 жыл бұрын

@@jurusco Nope. Still not magic. Our inability to understand the universe with current models does not mean the universe is inherently not understandable. We just need better models. Of course its possible that there is no model that can be completely understood by humans due to our inability to measure things beyond the limits of our own existence (multiple universes or dimensions, for example.) But that still doesn't make it magic in the sense of "there are no rules".. it just means we can't necessarily know all the rules.

@JamesSarantidis

4 жыл бұрын

@@altrag depends how you define magic. There are soft (no rules) magic and hard (with rules, like conservation of energy) magic systems in myths, legends and video games. You can also define magic as things that you don't understand. So, until we understand it better, one could argue that QM is magic (a system that has rules which we don't know about). The same way fire and thunder were regarded as gods until we devised tools not only explain, but understand at fundamental levels; enough to reproduce them (We still don't know a lot about Space, so that's why many people are into Zoroastrianism). Naming QM (or anything) magic should not prevent us from investigating it further though.

@altrag

4 жыл бұрын

@@JamesSarantidis I'm defining magic not as "things we don't understand," or even as "things we can't understand due to the limitations of the human mind." I'm defining magic as "things that are fundamentally not understandable _even by God_ " (that is, by a being that has absolutely no limitations on their intellect.) So kind of along the line of your "soft" definition, but in the most strict formulation of "no rules."

The best explanation of the double slit experiment ever. I actually picked up quite a few new pieces of knowledge.

@RAF71chingachgook

5 жыл бұрын

Nope. He's full of crap. Photon. Now explain it with a protein molecule. He's also ignoring the wave collapse experiments that were done purely on thought. He's clinging grimly to his imagined materialist pseudo reality. lol

@nybblesbytes4321

5 жыл бұрын

@@RAF71chingachgook Having looked at your channel I think I can safely ignore your opinion without losing any sleep over what I might have missed out knowing but thanks for throwing your 2 cents worth in anyway.

@RAF71chingachgook

5 жыл бұрын

​@@nybblesbytes4321 That's it buddy. Stay blind. This guy is preaching ignorance.

@jingato

5 жыл бұрын

I would immediately forget it. This guys doesn't know what he's talking about.

@frankblack1185

5 жыл бұрын

RAF71chingachgook RAF7qchingachgook I agree.

If someone says physics is ... - boring - for nerds - difficult to understand - badly explained - needs advanced math knowledge - or any other misconception ... Just send them to the Science Asylum and they 'll see the 'light' in all its beauty and clarity !

@michaeld9682

4 жыл бұрын

I can agree that these videos are great and they make "attempts" at what you claim

@stupidrainbo

4 жыл бұрын

@@michaeld9682 What's the difference between an attempt and an "attempt"

@michaeld9682

4 жыл бұрын

@@stupidrainbo the same difference between difference and "difference"

@stupidrainbo

4 жыл бұрын

@@michaeld9682 Is the difference between difference and "difference" the same as the difference between same and "same"?

@michaeld9682

4 жыл бұрын

@@stupidrainbo same difference

Whenever one of my classmates asks “so energy wasn’t conserved?” I always think of you: CONSERVATION OF ENERGY SHALL NOT BE VIOLATED!! ⚡️

I understand now! Feynman: "If you think you understand quantum mechanics, you don't understand quantum mechanics." Oh...

@ScienceAsylum

5 жыл бұрын

Ha!

@jensphiliphohmann1876

5 жыл бұрын

I think the often quoted alleged Feynman statements are by far too pessimistic. I don't know whether he still believed that there must still be something "thingy" about elementary particles like the electron ("wherever it is, it is a point charge") not regarding this as a mere artefact of it being elementary and thus just interacting as a whole.

@photonboy999

4 жыл бұрын

@@jensphiliphohmann1876 , How much Feynman have you read? He was never pessimistic in this way. Also, the idea that there is some "point charge" is meaningless to him and all advanced physicists. QED. Feynman diagram.

@jensphiliphohmann1876

4 жыл бұрын

@@photonboy999 I read some lectures and the QED book where Feynman is not pessimistic at all. My statement refers to some alleged Feynman quotes like "shut up and calculate" or so, and the alleged Feynman statement that no one understands quantum mechanics. Statements that don't really fit to Feynman's books.

@ianbridges3318

4 жыл бұрын

Feynman also said very clearly in his NZ QED lectures that light is a particle... though I think I prefer Nicks view that the detection of a single photon is indeterminate about its particle or waviness properties.

many people who try to explain the double slit experiment always do so in a very vague manner , its like they don't fully understand it .... but your explanation was very elaborate nick, you did the best way ... better than all other explanations.

Quantum mechanics might not be magic, but you have a magical gift for explaining things. You just demystified in mere minutes all the other videos and books I have read about the double slit excitement. I do believe Albert Einstein would clap for you.

This is a very useful and important video. The mystification of quantum mechanics is pedagogically horrific. We should always assume that everything can be understood, even if we don't fully understand it at this time.

@dpolaristar4634

5 жыл бұрын

Technically the more "radical" interpretations are not based on giving up on understanding but having a more nonsensical understanding.

@AirborneAnt

5 жыл бұрын

Observing collapses the wave function...I want to try this test in water or some other medium to record the track to the interference pattern rather than detector at the slits...hmmm...I’m going to solve this...

@aaambrosio3622

5 жыл бұрын

Quite bold to assume that the human mind can understand everything. That’s like saying we are the supreme intelligent beings in the universe. There might be things in the universe that we can never comprehend.

@thorstambaugh1520

5 жыл бұрын

@@aaambrosio3622 If that were true, then by contrapoint you have said there is a finite amount of knowledge we can understand. Which is as implausible as saying there are things we can never understand.

@aaambrosio3622

5 жыл бұрын

@@thorstambaugh1520 So, are you saying that it is more plausible that the human mind is capable of understanding everything in the universe?

Clearest quantum eraser description i have encounter.

Nick, I am drunk and I still understood your video, that's how good of a teacher you are. Everything so clear and still succint. Great job!

Nick just totally slam dunked the mysticism around the double slit experiment with extreme agression. This was VITAL, because as someone who have watched those vids, and been mystified, I needed this snap back to reality. Thanks!

0:24 Nick: Let's bring Quantum Mechanics back to reality Me: Oops there goes gravity

@jppatterson7142

5 жыл бұрын

Quantum gravity??

@99bits46

5 жыл бұрын

You only get one shot, do not miss your chance to blow

@studmalexy

5 жыл бұрын

that entangled photon looks like Mas's Spaghetti

@txorimorea3869

4 жыл бұрын

Is funny because is true.

@bijeshshrestha2450

3 жыл бұрын

@@jppatterson7142 bunny ,8 mile

I was having Science Asylum withdrawals, thank you for the fix 🙃

@gumunduringigumundsson9344

5 жыл бұрын

Yeeees! Fix! Ahhhh who needs beer when this this guy posts a vid. What a guy!

@gman064

5 жыл бұрын

Al H. Me too. He had me at hey crazies

@beri4138

3 жыл бұрын

Yes I have a withdrawal too I need heroin please help

@AL-SH

3 жыл бұрын

@@beri4138 Stop using heroine you junkie

@beri4138

3 жыл бұрын

@@AL-SH Lol you can't even spell heroin

you're the ONLY ONE who mentions polarizing film! this explains everything!!!

@ScienceAsylum

2 жыл бұрын

It doesn't _have_ to be polarizing film. It could be anything that reveals the slit information. I just chose polarizing film as an example of something that could do that.

This was a fantastic explanation. I've been trying to wrap my head around the particle/wave duality thing for ages, not to mention entanglement. This video makes things so much clearer now. Keep up the great work!

The 6 dislikes are the ancient keepers of the light. They’re displeased that you know their deepest secrets. We love your insight Nick and your ability to share it!

@xyz.ijk.

5 жыл бұрын

Seriously though, don't you sometimes just want to know who could possibly give this stuff a thumbs down? I can't figure out those people.

@STORMDAME

2 ай бұрын

@@xyz.ijk. Maybe religious absolutists insisting God did it or tin foil hat types who think all science is nefarious shadow governments trying to control us for reasons or people who don't like his voice or the colour of his shirt. People are weird like that. Hahaha

Crazy topic, expertly delivered, and the longest vid yet😁, great animations nick, 'Waves'from UK 🙋

@ScienceAsylum

5 жыл бұрын

👋

@SrmthfgRockLee

5 жыл бұрын

check out pbs space time explanation too

@blueckaym

5 жыл бұрын

I think for these topics video length around 10-ish minutes is more appropriate - otherwise (ie if shorter) explanations could be lacking (and thus understanding)

@ScienceAsylum

5 жыл бұрын

@Cameron McHenry 😂😂😂😂

@ScienceAsylum

5 жыл бұрын

@@blueckaym Yeah, that's why this video was longer. I couldn't make it any shorter without it being confusing.

Thank you, Nick Lucid, for your patience in replying to a question I had in another recent video. I had lost sight of the fact that you were dealing with motion/relativity; I hadn't yet put aside my (ancient) education in classical physics, and you very kindly set me straight. That really matters when someone's doing a scary thing - physics on their own!

I appreciate your grounded explanations of these topics.

Finally a good explanation!

You know it, all my life, I’ve been waiting I’ve been waiting for this

You explain stuff way better and more entertainingly than anyone else. Love this stuff!!!

Nick, this is by far the best explanation of the double slit experiment on the internet. I have watched most of them without helping me understand the deeper details. Thanks!

@ScienceAsylum

5 жыл бұрын

You're welcome :-)

I am constantly amazed at how well you create highly educative yet very funny videos (I love all the twins appearances and recurring jokes like the energy conservation ^^!)! This one particularly helped me demystify a lot about my understanding of this experiment. Thanks so much for what you're doing :) !

It put a big smile on my face every time Nick said QM is not magic! It was a lot of smiles... Then I laughed out loud through his conservation of energy chant! Thanks Nick! As with all your posts, my face hurts...

First video I watch from this channel. Subscribed before even finishing it, great job.

Man this video urge me to finis the Feynman lecture vol 3 as fast as possible and to read the volume more than one time.

This video is going to be another classic. You're a legend.

@ScienceAsylum

5 жыл бұрын

It was so much work! O_O

@halbeard2996

5 жыл бұрын

If there will ever be some video analogy for text book knowledge, this video will certainly be a standard explanation for the topic

@crouchingtigerhiddenadam1352

5 жыл бұрын

Here's a mystery. If a photon is the smallest unit of light, how do you end up with two entangled half-a-photons? How do you detect half-a-photon? I think the last part of your video requires watching a few times.

@halbeard2996

5 жыл бұрын

@@crouchingtigerhiddenadam1352 It is the smalles packet of electromagnetic energy of a given frequency. That means the frequency is halved when the photon pair is created (it can also be any other proportion as long as it sums up to the original frequency) because energy is proportional to frequency. Such a process is also known as down conversion if you want to read up on it. The crystal needs some special properties that generate a so called nonlinear optical response. Most everyday materials only have a linear response, which merely alters the path of the light (reflection and refraction).

@crouchingtigerhiddenadam1352

5 жыл бұрын

@@halbeard2996 there is a common definition given in physics which goes something like this: _the photon cannot be split. It has zero mass. It cannot decay. It can interact with another particle lose part of its energy and change wavelength._ ... and then there is QED and the *vertex function.* Questions like, _if light is an electromagnetic wave, what is the relationship between a photon and an electron?_ or _how many times can you split a photon?_ _(why is the answer 3?)_ On KZread you would think Quantum starts and stops with the wave function. Yet the meaty stuff is in vectors.

After watching lots of explainations on this, I finally understand it. Thank you, Nick!

@costa_marco

5 жыл бұрын

"I think I can safely say that nobody understands quantum mechanics." -Richard Feynman, The Character of Physical Law (MIT Press: Cambridge, Massachusetts, 1995), 129.

@JB_inks

5 жыл бұрын

@@costa_marco at the time he was probably right.. So what?

@costa_marco

5 жыл бұрын

@@JB_inks Chill, man. No offense intended.

@99bits46

5 жыл бұрын

what explanation?

@photonboy999

4 жыл бұрын

CJ the baka, There are various levels of understanding. However, NOBODY is confident that they understand what's going on here completely. How do the particles change what they are doing based on a seemingly future detection? Nobody knows.

Best description of the double split experiment EVER! Fantastic Nick, thank you so much.

This channel is criminally under subbed and under viewed.

I think I've seen or read dozens of explanations of the topic along the years. This is the best one yet. You kicked the most famous QM experiment right in the mystification tender spot.

10:37 "You can just as easily say the pattern on the wall is what determines what happens at the other detector". That doesn't explain why the pattern changes when you modify the other detector, though.

@ScienceAsylum

5 жыл бұрын

You're correct, but the point I was trying to make was that we shouldn't be so quick to jump to conclusions. Quantum mechanics tells us _a lot less_ than we (subconsciously) want it to.

@kenny_u

4 жыл бұрын

@@ScienceAsylum Are you going to make a video on Quantum Mechanics interpretations? I think you'd do it justice!

@ThailandExperience

3 жыл бұрын

@@ScienceAsylum So does that mean that magic happens here?

Hi Nick. My 12 year old son wandered across your videos started asking me a lot of questions. He loves your videos and I must say that I am also highly impressed. One part of your explanation, and that of other videos on this topic, show that when an observer is present (a measurement process that must in some way interact with the particle moving through the slits) the act of observing is "collapsing the wavefunction". The interference pattern changes quite significantly from the far-field pattern of a normal two slit case to two stripes. Given that the far-field pattern is itself due to the size of the slits, their spacing and that sufficient distance has been allowed to propagate the wave/particle to the screen to show a particular diffraction pattern, wouldn't the two individual stripes be overlapping, representing the overlap of the single-slit far-field diffraction patterns; one from each slit. However, if this is the near-field (to the slits) pattern of the "single-slit case" wouldn't the interference pattern of the "two-slit case" look more like the fresnel diffraction pattern with a higher-spatial frequency interference pattern than you present? When you take into account that the BBO crystal is causing a degree of decoherence between successive photons entering the system, the interference pattern should wash out into a incoherent pattern. You may want to review the comments I made and links I provided to Sabine Hossenfelder's video: kzread.info/dash/bejne/hIWql6WPda-tY7g.html This is a difficult experiment to use as a basis of explanation of the Delayed Choice Quantum Eraser but variations on it investigated by Alain Aspect offer less room for misinterpretation and highlight the weirdness of such quantum experiments. Using an experimental setup which does not use a BBO crystal to achieve entanglement limits the complexity of the analysis. For those interested to review another source that is relatively accessible (again .. judging by my 12 year old son's ability to pick up the main points), take a look at: kzread.info/dash/bejne/h2qaq5WborOehpc.html and kzread.info/dash/bejne/p39mx6ivZ9HLj7Q.html . I truly respect your work and how it is having an impact on learners of all ages. You certainly have a big following amongst pupils at my son's school as he cannot stop talking about the wonders you have shown him.

the perfect explanation u may ever get on you tube as in present and in future

This is truly legendary!! You really deserve a noble prize!! No words to thank you!!!

Nick, when you say "all those videos were designed to mystify you", I knew you gonna kill it. All those videos are twisting our minds to make us awwwww and owwwww, your videos makes us understand. You are literally the best science youtuber for education, the other ones are more in the show business. Exceptional.

man! you're awesome! Am a huge fan of your clarity of thoughts and crystal clear way of articulate things! keep posting more and more videos :)

A breath of fresh air on this experiment! Most other people's explanations are full of quantum woo woo.

The interference pattern was observed not only for photons but also for large atomic and molecular classical particles. All your explanation is valid only for photons which are not actually classical particles.

@CodepageNet

5 жыл бұрын

is anything a "classical particle"? it's all made of energy and waves... with larger amount of elements involved, the harder it gets not to collapse the waveform because chances of interactions are getting bigger. thats why we don't fall thru the floor.

@habtiephys

5 жыл бұрын

@@CodepageNet The very simple difference: classical particles have rest mass whereas photons do not.

@ScienceAsylum

5 жыл бұрын

1) The double-slit experiment can be done with all sorts of particles. The same rules/results apply to all of them. I just used photons in my video because it was a good transition from my previous video and because they're the first particle we did this experiment with. 2) Larger particles only behave "classically" because they're constantly interacting with things making them localize. If you could get a dust particle to be isolated for long enough, it... _should_ behave like a quantum particle too.

@habtiephys

5 жыл бұрын

@@ScienceAsylum Thanks!

Hi Nick! You're really clever. I've learned new things about the experiment. You show it in a different perspective. Well done, it's a pleasure to support you on Patreon.

Thanks again for all of your great work! I am always recommending your channel to friends and family. Stay cool bro :)

This is probably the best, clearest explanation I've ever seen for the DSE, especially with the quantum eraser!! Kudos. I do feel the last bit was really rushed, and I see I'm not the only one. Could have definitely been worth the while to spend 2 more minutes on what actually happens there.

Great job Nick, after watching so many videos about this trying to figure out what kind of magic was happening here, it seems you are the only one that deserves the Nobel prize that has been put at stake! great explanation & a really conclusive model

Great explanation! Now I want a video on the interpretations.

You really outdid yourself with this one. Easily the best video on the double slit I've seen. And I've seen my share. Good work demistifying the thing.

@ScienceAsylum

5 жыл бұрын

Thanks! It was a lot of work.

Thank you for going into detail about these experiments. I have often been confused how such absurd conclusions were drawn from them, but now that I understand the actual experiment I feel conformable about disregarding the more radical conclusions. I really liked towards the end of the video where you mentioned that it might just be a limitation of the experiment. Love the channel. Keep up the good work questioning everything.

Thanks again adds a lot of clarity and demystification to this well covered topic, just goes to show if I tune into Science Asylum there's always always something to gain.

I'm sat here watching thinking it's about time someone talked about this with common sense ,but perhaps we had do to the mystery tour first😉 thanks for the video.

Love it 💓💓 Im subscribing now. I hope u continue using simple words and explanations so we, who are not native english speakers, can easily understand. Your videos are much better than those ive watched. Thank you, sir 💓💓

This is the clearest I've ever seen the double slit and quantum eraser presented. Thank you Nick!

Lot to soak in with this, but I think the biggest thing that meant the most to me personally was understanding that tiny particles like photons are still waves. Just really tiny ones. I admit I still thought of them as, like... a very tiny ball. Of course it makes much more sense now that something so small wouldn't be represented that way. It's still kind of crazy to think of these photon waves as having probability fields and such. But you make another good point that it's just hard to accurately measure how such small things behave when we're so incomprehensibly massive compared to them. I find quantum mechanics (and trying to understand them rationally) an engaging subject, maybe because I want to understand how the universe and physics work at its most basic, fundamental level. Also, kind of trippy to think everything that exists is fundamentally made of very, very tiny waves colliding and interacting with each other.

@photonboy999

4 жыл бұрын

On wave/particle duality. Sub-atomic particles very well may be point charges moving about in a wave-like pattern. The PROBABILITY is based on interacting with particles and finding the likelihood of them being in a certain point. It's not a provable "thing" in the sense of physicality. It's probably best to think of them as PARTICLES which locally vibrate in a wave-like pattern whether standing still or propagating through space.

@chique2008

3 жыл бұрын

I saw a theory today about this which was the particle is ' riding ' the wave much like a surfer . The wave splits into 2 and the particle goes one way and the two waves create the interferance, this I think would account for the interference but not the collapse when which way is detected

@silverish9081

Жыл бұрын

@@chique2008 That's the Pilot-Wave interpretation of quantum mechanics. I believe it's one of the refuted ones

Totally worth all your effort with the animation! Great result! This may be the best explanation of the topic I've ever seen!

@TheCimbrianBull

5 жыл бұрын

Agreed! If only KZread and videos like this existed way back when I was struggling with the same topic in high school. I'm a visual learner so just reading text and the teacher writing down equations on the blackboard didn't make much sense to me.

Man, your videos are awesome! Everything is so well explained! Thanks

Love your videos! Thank you! Hope you can keep doing these!

Yay! 11 minutes 48 seconds of pure joy!

@TheJohnblyth

5 жыл бұрын

I can’t believe it was that long: it just breezed by, so absorbing it was.

11:03 "In quantum mechanics, maybe the rational perspective is the craziest." Well, that would certainly be consistent with this channel. 😀

Very few youtubers are able to blow my mind, you're the first place on my top 5, what a genius explanation, just bought your book on gumroad.

I'm so excited about and looking forward to the video about quantum delayed choice explanation!!

Finally, someone who treats Science as it is: tentative. I love you

You are something more than a physics teacher Nick. Thanks for your work and for ... being.

Please go down the rabbit hole! Hehe... but seriously, nice work on the double slit explanation. I love the way you add perspectives which few other make! Its a nessesary thing

jesus. cant imagine the youtube science community without you. I actually watched every single one of the videos(and some more) u showed at the begining (and agree with ur verdit 100%)and none of them gave me the satisfaction that this vid did. I'm donating in the very near future.

The explanation, by itself, is the best on the internet, But, the ANIMATIONS make this so damn accessible to laypeople and quasi-laypeople that it should be required as the first video ANYONE ever watches on this subject. Your gift of teaching/explaining really shines on this video!!

@ScienceAsylum

5 жыл бұрын

These animations were SO HARD! Not just for me, but also for my computer. It took 6 hours to render the video.

@indianapoliswingchun

5 жыл бұрын

Well hopefully it didn't drive you insane (..or any MORE insane) because they really hammer the point home. As you mentioned, there are TONS of videos on this experiment and I've watch most of them, but nothing compares to this. THANK YOU!!

such a relief that someone can explain this without showing it like a magic !! i like the graphical explaination of photon after passing the slit btw it get me realize few things . one thing i like about this channel is i never lose focus while watching

wow, this time I actually understood it perfectly, very nice job Please make a follow up video talking about the quantum interpretations, that would be amazing

This video deserves 10 million views. Finally someone who does not try to mystify quantum entanglement. Thanks !

The animation of probability waves moving and collapsing at 5:44 onwards were really helpful, something I haven't seen before -- thanks very much!

@ScienceAsylum

5 жыл бұрын

I've never seen it anywhere either. It's straight out of my brain. I'm just excited I finally have enough skill to animate it.

@TheRABIDdude

5 жыл бұрын

@@ScienceAsylum I was going to say they're excellent! It was a prudent move to plaster them with your logo ;)

@user-ye7wk7tp4x

5 жыл бұрын

I also like these ones kzread.info/dash/bejne/fX-mm5OvZ9yyk7A.html kzread.info/dash/bejne/hHprxqatY9e8naw.html

Thanks for the best explanation I've ever seen. I've long had headaches trying to explain people that an "observer" is really just "anything that interacts with the particle, conscious or otherwise".

Best and clearest explanation for QM I have ever heard. Great video 👍👍thx

Such a great explanation! I don’t know if I agree with the hypothesis you chose for the explanation of the quantum eraser but your guess is probably better than mine! Thanks for the great videos!

Two things I've been wondering about this: 1. According to Special Relativity photons don't experience time, so could that be part of the explanation? That from the perspective of the photons both detections happen at the same time? 2. If instead of a beamsplitter you used a switch that sends all of the photons either to the detectors or to the eraser, would that get you an obvious pattern on the screen before the data of the detectors become available? I expect not, but from the description of the experiment I can't find a reason why it wouldn't.

@photonboy999

4 жыл бұрын

#1 - Special Relativity does not say photons do not experience time. Special Relativity is about LOCAL TIME etc but photons have a definite speed which is the speed of light. It takes eight minutes roughly for a photon to leave the sun and hit the earth. There's currently nothing that says they are outside of time or that the laws of causality can be violated. (however things might be vastly different at some deeper level but the observations by Einstein don't imbue photons with such properties as being outside of time etc...) I know there are thought experiments about "how would you experience time bla bla at the speed of light" but then jumping to the conclusion that photons are outside of time. That is simply not what's going on. #2 - Switch? Remember it is ONE photon at a time. If there's no beam splitter and you send to the screen then the results should be the same as the normal double-slit experiment. If you sent it to the detector instead of the screen it would just... detect them... of course, nobody truly understands how the SPLIT photon is aware of the other split photon especially when there's a time delay for detection but again without splitting them you're sending the single photon to one detector or the other. If you sent MILLIONS of photons to the screen only, then MILLIONS of photons to the detector and got different results from the screen alone that suggests.... it makes no sense actually. How could you send photons to a screen, build up a pattern, for say five minutes then do... nothing. Then repeat that but this time after you spent five minutes sending photons you start sending to the detector and...no wait, the screen pattern would need to change BEFORE you started because of... time travel? No... I get that there's some appearance of knowing the future but it can't actually be based on everything we know. It's possible that the speed of light is not the maximum speed and that there are much smaller, faster particles interacting with our environment in ways we can't yet know.

@Zarnagel

4 жыл бұрын

@@photonboy999 1. Okay, first of I haven't actually studied this stuff, I'm just a layperson who got everything I know about this subject from videos like this one and popscience books. But that being said, what I've learned about Special Relativity does indeed say, that photons (or anything else moving at the speed of light) do not experience time. Not that they are "outside" of time, but that time dilation becomes so great at the speed of light, that all of time appears as a single instant. And that's not just thought experiments, it's in the equations and there's also observational evidence from particles moving close to the speed of light. 2. That's what I was getting at. If you take the randomness out of it and all of the photons get either detected or erased, could you tell which is the case just by observing the screen? That would essentially mean seeing the future, so I expect there's something that prevents this, but I can't figure out what it is. Having thought some more about this, both these questions are a little beside the point though. The real question is: what is the physical difference between detection and erasure that makes the wave function collapse in different ways? That does indeed seem eerily like "the photons knew we were watching"

@kentnimmo7369

4 жыл бұрын

i think the best way to think about if light and time is that light experiences what we call time as space. light cannot tell the difference between what we call space and what we call time. so yes you are right light does not experience time but that is because the order of events is purely spatial. which has the same limitations of time.

Best explanation of the double slit experiment I have seen

Very clear very understandable content. The illustrations, animations are really really helpful and simple to understand for simple people who are interested in these topics however do not have enough brainpower to understand these things without such explanations, so thank you a lot for making these contents! :)

Best explanation of the Quantum Eraser I've seen to date :-)

The explanation starting at 5:41 didn't just blow my mind, it reassembled it better than it was before. Everything clicked when i saw photons as probability waves, the "dot" you detect is just the random sample from that probability distribution

@jjhhandk3974

5 жыл бұрын

So why doesnt the detection of each single photon resemble a wave? Why does the wave collapse into a single point instead distributing a wave pattern onto the detection screen?

Good christ! FINALLY an explanation that doesn't resort to trying to make these experiments and their results seem more complex and mysterious than they actually are with 'woo' and over anthropomorphising. Of all the thousands of videos out there this is probably the most accurate and clear off all. Great job!

This completely just clarified my understanding of probability waves. Wow. That's awesome.

OMG this is the best explanation I've ever seen! Thank you!

Like a mental fog light, your video illuminated a subject that I could never see. QUANTUM MECHANICS IS NOT MAGIC. The double slit experiment has been misrepresented SO many times... THANKS NICK!

I laughed so hard when you used the "engery is always conserved" bit again

@ScienceAsylum

5 жыл бұрын

I'm working up to something with those 😉

@tigerkill420

5 жыл бұрын

Wow your only the second creator to ever respond to a comment I made. Love your stuff Nick. Keep up the good work.

Wow!! Thank you for creating this. Absolutely blowing my mind.

this is the clearest explanation of delayed choice quantum eraser I've seen. whenever I need to explain it to someone this is where I'll send them

both are detectors and it doesn't matter which it hits first, that statement actually made a lot of sense :)

11:14 The answer is: No, Maybe and Yes, all at the same time, depending when you ask and if you erase the answer or not.

Nick, I've said this before, but there is something about the way you explain things that inevitably makes me go "OHhhhhhhhhhh" at least once per video. This time, though, it was the whole damn video that made me go "Ohhhhhhhh!". Seriously, I felt like I understood the double-slit experiment pretty well, but suddenly it ALL MAKES SENSE. Thank you! Please keep doing these videos -- you have a peerless talent for explaining science

This made me buy your textbook. Excellent as always

This is BY FAR the best explanation I've seen of the double slit experiment. This video should be mandatory in physics classes in schools.

Thank you grand master Lucid 👌

Sir I really enjoy your channel and I especially like the slightly longer episodes such as this as it makes it easier to comprehend.

@ScienceAsylum

4 жыл бұрын

Now that Patreon patrons have allowed me to make videos full-time, it's a lot easier to make longer videos.

@greamespens1460

4 жыл бұрын

@@ScienceAsylum thank you and may I thank your patreons too.

Finally! A simple, easy to understand explanation of the double-slit & quantum eraser experiments. I've watched many videos about these experiments and none have given me a satisfactory answer until now. Thanks!

@ScienceAsylum

5 жыл бұрын

You're welcome :-)

"The Best Ever"explanation of Quantum mechanics and the double slit experiment. You deserve a noble prize for this Nick. Great presentation 👍😊👏

I love the down to earth approach! Reality check 🙂 let's not go down rabbit holes, thank you! Even some of the most brilliant scientists seem to like the "explain quantum mechanics as science fiction" approach in order to attract people, and I can understand wanting people to jog their minds and become creative. But let's beware of rabbit holes and wonderland 😧

Thank you SO much for this! It's the most enlightening discussion of this topic I've ever encountered since I was a physics minor in the late 70s. .... or, actually, ever.

Best explanation of the quantum eraser I have seen.

This is the most underrated channel on youtube.

The explanation on the double slit experiment was brilliant. The quantum eraser experiment still puzzles me though. Even if we think of the screen as a detector I don't see how the entangled "twin" can know if the other one went through the "which way" path or not after the fact and how it can be erased.

@jayaceto1980

2 жыл бұрын

Yes, I am also struggling with this big time. Even if we consider the screen a detector, and the shape of the wave function as it hits the screen determines whether or not it will get detected at detectors A or B, or it will pass through to the quantum eraser box. This still makes absolutely no sense to me. If there is no polarizers at the slit, wouldn’t the photon pass through both slits, hit the BBO crystal and prism, one of the entangled twins would hit the screen dispersed in space as an interference wave function, the other entangled twin would pass through to the quantum eraser box in this case. That would happen every time if there is no polarizer at the slit and it is true the screen detection determines what happens at rest of the apparatus. Why would the photon ever pass through just one slit and hit the screen in the more localized single peak wave function and in turn be detected at detectors A or B if there are no polarizers at the slits to cause this to happen. I am struggling really hard with rectifying this one aspect of this explanation, it just doesn’t seem to make any sense to me if the screen is determining what happens at the rest of the apparatus, it would still be dependent upon if there is a detector at the slit or not (in this example the detector is a polarizer). Could you please explain this more clearly, please. @The Science Asylum

I am probably not as confused as before but certainly I am more confident now. Thank you for the direct and rational explanations.

This is the best explanation I have heard on the subject, I thought I understood it pretty well, seems like I just didn't really care enough to look for holes in my understanding, thank you

@ScienceAsylum

4 жыл бұрын

You're very welcome :-)