I made a (useless) quantum computer at home

This video was sponsored by Screen Australia and Google Australia through the SkipAhead Initiative.
Thank you Kathy for the beautiful animations! kathysarpi.com
Part 2: • What can my homemade q...
If you want to do this experiment at home, you can! It's very simple.
All you'll need is:
a weak red laser pointer (the type in cat toys are generally safe)
polarizing film or polarizing filter. If you have polaroid glasses or certain camera ND filters you may already have this. Otherwise it's available on amazon
half waveplate (the plastic thing) is this one: www.edmundopti... (λ/2 Retarder Film (WP280))
You don't need calcite, but if you want to play with it, you can find it on etsy usually. Look for a sample that's exceptionally clear

[@LookingGlassUniverse]

Part 2 is up: kzbin.info/www/bejne/qnnJeKiZfdl_p9Esi=s-mr2l79q46_QkJ6 If you want to do this experiment at home, you can! It's very simple. All you'll need is: - a weak red laser pointer (the type in cat toys are generally safe) - polarizing film or polarizing filter. If you have polaroid glasses or certain camera ND filters you may already have this. Otherwise it's available on amazon - the half waveplate (the plastic thing) is this one: www.edmundoptics.co.uk/f/polymer-retarder-film/14827/ (λ/2 Retarder Film (WP280)) - You don't need calcite, but if you want to play with it, you can find it on etsy usually. Look for a sample that's exceptionally clear. - BBO: I spent a while messaging people online and had trouble tracking it down :'( I'll settle for KDP or even KTP.

[@MagruderSpoots]

Did you really point a laser at your eye?

[@SoaringMoon]

Got to write a paper on manual quantum computation with 16 qbits.

[@SLAYERSARCH]

the trick is analog or mechanical systems are way faster than a transistor.

[@itoibo4208]

Thank you for this. Finally "superposition" sounds less like magical gobbledigook nonsense, and more like something normal when explained in a realistic and logical way. If I understand correctly, this means one component can be a 1 while another component can be a 0, and saying one thing can be both 1 and 0 is just a very poor and confusing way to describe it, especially to lay-people.

[@sabbirhossain6408]

You're so wrong

[@LookingGlassUniverse]

The next video will be up next week! For everyone who very generously offered to help with the code on my last video- sorry I've taken a while to get back to you! I'll get on it today :)

[@itsbs]

How is it possible to get a PHD for a theoretical device that has only proven to generate random numbers? The idea of Quantum Parallelism has already been proven false, i.e. theoretical Qubits do not compute all possibilities at once.

[@kashmirha]

You are Alice in Quantumland AND Schrödinger's cat in a SUPERPOSITION: 1:37 :)

[@zach4505]

Amazing explanation and your curiosity is infectious! My coworker who is a physics teacher and a hobbyist for anything rocks and minerals. Maybe they can manipulate some calcite for a class demo.

[@yiannchrst]

4bit adder incoming? 👀 something else? can't wait to see!

[@itsbs]

@@ThePowerLover ** It is really weird that people would spend so much time on a Quantum Mechanical theoretical machine that has had 10 years and billions of dollars to actually produce an output... but yet, it has done nothing. The ENIAC only took about 2 years to start producing output that was used for war.

[@JannisJG]

That is pure brilliance! I‘m studying form my QC finals at MIT and procrastinated with this video, and this is such an amazing viewpoint! Really excited about part 2!

[@LookingGlassUniverse]

Good luck!!

[@rameshdevasi6720]

@@LookingGlassUniverse meditation is a quantum process, ancient practice of being so conscious of present moment that u lost normal consciousness of body and mind and enter into pure state of void without any though but still super conscious and its blissful, scientist should try this even the Schrödinger read book like Upanishad to understand the ancient wisdom.

[@ryukshinigami4197]

@@rameshdevasi6720 which book?

[@abi3751]

​@@rameshdevasi6720huh came with that thing, this is written long back in India😂

[@GeoffryGifari]

I notice that Alice's animation is getting better and better. Hopefully this will continue

[@LookingGlassUniverse]

I have an animator, she’s incredible: kathysarpi.com

[@brothermine2292]

Wasn't Alice blonde, and always wearing a blue dress? This may be her evil stepsister Eve.

[@rosuav]

@@brothermine2292 The actual Alice Liddell wasn't blonde, but Disney made her into that. I've seen her in a variety of different colours of dress, so there's no reason she can't wear a lovely red one to match Mithuna!

[@brothermine2292]

@@rosuav : Thanks for that info. But my reply was about the Alice who used to frequent this channel. Her hair was always blonde and she always wore the same blue dress. Eve will be needed if this channel produces videos about cryptography, in which Alice & Bob want to communicate without any Evesdropping.

[@supercheetah778]

​@@brothermine2292Along with Bob who will be wondering what happened to his messages from Alice.

[@FacepalmProduction7]

I really appreciate how you explain complex things so well

[@Kelticfury]

I love it when i find someone who is so smart that they can explain super complex physics to a normal guy like me. You are inspirational for us nerds who never went to uni.

[@samsibbens8164]

Q: "Why does light move slower in different mediums?" A: "I have no idea, stop asking me." That gave me a good chuckle xD. But thank you for the answer

[@arthurdoktor]

"Mom can we have quantum computer at home?" "We already have quantum computer at home" Quantum computer at home:

[@w花b]

Okay

[@jojolafrite90]

M'kay.

[@OuterSpacePeace]

Valid lol

[@michaelsommers2356]

"I hate doing experiments." Spoken like a true theorist. Do you know the story of Pauli and Bohr? Whenever Pauli would visit Bohr in Copenhagen, as soon as he crossed the border into Denmark, all of the experiments in Bohr's lab would suddenly break. Somehow I missed your last two videos. Sorry. I'm glad you finally found a happy electron. Usually they are so sad. I also like your new version of Alice. At any rate, I'm glad you're posting again.

[@kayakMike1000]

Oh that's Alice. I thought she race swapped herself.

[@w花b]

​@@kayakMike1000lol

[@davisnoah347]

There will never be a happy electron. Pipe dream. Give up all hope of ever seeing that.

[@-nepherim]

The description of waves operating in 3D and thus made of vectors is the critical piece that's been missing for me since high-school! I finally get it! Thanks so much, such a great explanation!

[@pineapplegodguy]

i can't describe how much this channel blows my mind. i was screaming at the screen at 19:05 BTW to see our old friends Alice and the negative electron come back animated was really fun, and truly a good strategy too to fortify your "brand" since it is so recognizable for us long time viewers

[@LookingGlassUniverse]

Thank you so much for sticking with me❤️

[@jojolafrite90]

Why does everything has to be "a brand" nowadays? Even personality is "a brand" for anyone. Sick society. She deserves it, so she should deserve it, that's it, for me.

[@julian1000]

Glad this got recommended! I took a "NAND to Tetris" style class in undergrad, there's real magic to making a computer. Your generation is lucky enough to be making tabletop quantum computers for cheap!

[@florbz5821]

I cannot WAIT for the next video! This was honestly the BEST explanation I've seen for me to understand the basics of quantum computing while keeping me engaged throughout and I love how you simplified it to it's core components separately! Really excited to see it in practice! (I do wish that the personification of the wave of light was a bit less terrifying and uncanny though...)

[@LookingGlassUniverse]

Ahahaha thank you so much!! Sorry for creeping you out with the light caterpillar

[@RiccoThiel]

I just love your videos. they are so fun to watch. please keep doing what you're doing!

[@genmen]

The genuine surprise at the end (not being useless after all) is priceless. Thank you! Your excitment is truly entangling 😊

[@jojolafrite90]

I, for one, thought it was quite charming, the bit when she seems surprised and says it's gonna be in the next video. This did lighten-up my day, somewhat. 🙂

[@genmen]

@@jojolafrite90 absolutely, makes me want to buy some lasers 🌟

[@DaveHarrold]

This is the first Looking Glass Universe video and my first real-step into learning about quantum computing. Having graduated HS in 1961 and only completing a few college courses I need things explained very simply and this lady does that in a very entertaining way. I'm looking forward to watching more Looking Glass Universe videos.

[@JessWLStuart]

I worked on a Birefringence Measurement System many years ago. It's awesome to see Birefringence in a real world example!

[@kreynolds1123]

I had long ago wondered how plastic polarizers were made. I knew the polymers were alligned, but I didn't know how. It just occured to me that they are aligned by a process similar to making stringed mozzarella chease. Cheese is made up of chains of amino acids that make up the proteins in cheese and start off randomly aligned. Then when you pull a blob of chease in one direction, all the proteins sticking tother and slide past each other are pulled into a common alignment in the direction of the pull. With plastic, a sheet can be made by pressing a blob in one direction. That reduces the polymers degree of freedom to random alignments in two dimentions of a sheet rather than in 3 dimentions of a blobe. Now pulling on a sheet in one direction in the plane of the sheet will mostly align the polymers down to one dimention of freedome. But to achieve better polymer alignment, the long sheet can be cut many times into squares that get stacked with their polymers aligned and gently heated as they are pressed and pulled again to improve the polymers' alignment.

[@byleew]

Super cool! 😀Love your enthusiasm, curiosity and ability to simplify what seems complex. Looking forward to your follow-up. I suspect you are about to cook up more interesting insights 💡

[@mike8877665544332211]

Thank you for explaining quantum computing so that even kids could understand it. Awesome channel, glad the algorithm found it for me.

[@bogosbinted._.]

You’re my inspiration, I am about to start my undergraduate degree next year and whatever I achieve further down, i owe it to you, since you restored my confidence in the subject despite failing in it multiple times. Thank you and wonderful work!

[@moonasha]

20:38 "I definitely would not have come up with it" you just described 99% of my programming career lol. I did not expect this video to go into such depth, but I was not unhappy about it. This subject is honestly borderline impenetrable, I still don't have any idea wtf is happening with light polarization, I understand how it's illustrated but... well... waves are 3D in reality, pictures are 2D, does not compute in brain. And then you have the whole circular polarization thing which is just .. wat?

[@franzperdido]

Whatch out for those lasers. Or rather not. I mean, just don't point them at your eyes, they can have quite devastating effects. I'm sure, you're well aware but just thought I'd mention it since some people might want to reproduce your (super cool) experiment! Love your videos, btw!

[@smishdws]

Banger video! I never really thought about how simple some core concepts of quantum computing can be conceptually, and how immediately accessible it is to demonstrate them!

[@daniel.jmolepe1844]

One of the best educational videos I've seen on KZbin's platform. Thank you bath for your work and time!!!

[@AdrianGarcia-dm4ep]

I believe it was 3 blue one brown that made a really good series to teach how light is slowing down in a medium.

[@JamesMBC]

The quality and brilliant simplicity of this video is amazing. If only schools could be this engaging and educational. They have a lot of catching up to do. Awesome, as usual!

[@rick9943]

I've been sort of randomly down a rabbit hole of quantum youtube videos lately and this is by far the best explanations I have seen.

[@AlexFoster2291]

This is wonderful. I just found your channel for the first time. I love the time spent carefully explaining every aspect along the way. You're an awesome educator. Liked and subscribed.

[@wanfuse]

They say that you can tell how much a person understands a topic by how well they can explain it. This is Feynman level of explanation- it is that good! Seems like this is like multiplying two real numbers in spherical space ( at least in part) when compared to multiplying integers in spherical or non Euclidean spherical spaces. Trying to understand where the extra degrees of freedom, sum is a worth more more than the parts comes from, but is not able to be emulated in non quantum space, could definitely use your explanation capabilities to inform the rest of us! Thanks for the great video!

[@justinbasinger7728]

The way you explained this cleared up SO many questions I've had about this stuff. It's been just too complicated and you perfectly simplified it for my style of thinking! Thank you so much

[@VishnuRajam4x4]

I feel like I’m learning about quantum computing in a kindergarten classroom. This is a good thing. I’m understanding everything and loving it

[@griffithf.k.4136]

Mithuna, I was a fan of your whiteboard videos from almost a decade ago. Didn't realize you had returned to making videos until this got recommended to me (I thought I was a subscriber, who knows what the algorithm is up to) and it's such a breath of fresh air. I'm so glad to see the same clarity of thought in this new format.

[@maxnao3756]

Never Never! show to your audience which may now little about what a laser is, that you check the lasers by looking into them.

[@peetiegonzalez1845]

That poor hapless electron. I'm so glad you are making videos again. Your explanations are some of the best on the entire Youbiverse.

[@linkcell]

I'm so so proud of you. Been following you for what feels like a decade now. The production value of your videos just gets better and better. So lovely to see your work coming together.

[@tgc517]

Gosh, this is the only person in the world who can possibly explain this extremely simple system to us, are you joking me. Literal professors can’t even come close to this good of an explanation without using words that mean nothing to me. Like, cool they can be both 1 and 0 but like has physically (the particle is vibrating in two directions both horizontal and vertical is all they had to say but noooooo), no professor I’ve seen on KZbin has ever attempted to explain it as well you have.

[@Thats_Mr_Random_Person_to_you]

Such a great video!! Loved your breakdown of vector math and that the basic fundamentals of quantum computing is basically just pythagoras and trigonometry... its just the same math as complex numbers. Your descriptions are great at teaching complex stuff with just the right amount of complex and 'simple' (ie ignoring really complex stuff that isn't required to understand the fundamental concepts, but still going deep enough to allow us to learn new stuff). Also you show how this 'mysterious' superposition idea that people can get caught up on is around us everywhere, we just dont use the term 'superposition'... ie the 'sound' or 'timbre' of an instrument, that allows us to identify a piano vs a trombone is because of the combination of frequencies that make up each note... we hear one 'sound' or one 'note' but that sound is make up of a load of different, but related frequencies all mushes together. Suddenly concepts that people understand are also the same concepts as superposition just named differently (like the math is fairly similar as well - an Fourier Analysis shows the component frequencies just as it would on your light source, other Analysis could show the different phases of those frequency components, as it would with the light etc).

[@kmunson007]

Loved this video! Can't wait for the next one. I especially love that it allowed us to see some of the "figuring it out" part. Being from the South in the US, I laughed out loud at "the hell?".

[@DavidvanDeijk]

Amazing video, and the other video about speed of light in water was a great primer. It's awesome to get such a good explanation from someone that actually studied quantum physics without getting bogged down in jargon. Thanks and looking forward to the next episode

[@philipm3173]

I just rewatched your video on your PhD, and from my limited understanding, the computing advantage is that the qubit unlike a digital logic gate has the entire complex plane available which is a massively greater information space; in order to simulate that in it's entirety you need to numerically approximate a hilbert space. The computational difficulty and advantage lies in that rather than using logic gates to do complex matrix calculations, the bits have an intrinsic complex space available. The information is distributed rather than being localized as in digital memory.

[@nickallbritton3796]

love this concept. btw i'm clipping where you shined the laser on your face to give my lab instructor a heart attack :d

[@LookingGlassUniverse]

Please do, it’s a great demo of what not to do

[@bobbuethe1477]

Describing qubits in terms of polarized light is the first explanation of quantum computing that begins to make sense to me. Thanks!

[@GadgetsArise]

Omg, I just found your channel, and I love your content. Your videos are so underrated and deserve more likes!

[@minformationcenter9351]

The video is about making a homemade quantum computer. Here are the timestamps for the different sections: 0:00-1:05: Introduction and motivation for making a homemade quantum computer. 1:05-3:20: Explanation of what a qubit is and how it works. 3:20-5:35: Explanation of how light can be used to create qubits. 5:35-8:20: Demonstration of how to filter light to create a specific qubit state. 8:20-11:00: Explanation of how a calcite crystal can be used to perform computations on qubits. 11:00-13:20: Demonstration of how to use a thin calcite crystal to perform a simple computation. 13:20-15:00: Discussion of the limitations of the homemade quantum computer. 15:00-17:00: Conclusion and plans for future videos. I hope this summary is helpful! made by "google bird ai"

[@Rampart.X]

Where's the timestamp for retinal burn?

[@acrien]

very interesting, hope to see more of this (maybe more useful quantum computers homemade) in the future. I believe one of the reasons why light "slows down" in a medium is not that light slows down, but it gets diffracted thus changing the distance it has to travel to leave the medium, making it look like it slowed down.

[@lawrencejob]

At some point in this video I accidentally finally understood circularly polarised light while you were moving the fuzzy sticks around. It’s the horizontal and vertical components being out of phase… Thank you so much - 10 years of professors waving their hands and saying “oh and there’s circular polarisation light but don’t think about that” and a KZbin video makes it click for me

[@LookingGlassUniverse]

Yes! That’s it. I feel bad for cutting it from this video but I’m glad it was clear for you anyway

[@AbhineetAsthana13]

Thanks to your incredible videos and style of explanation, my understanding of quantum mechanics/computing keeps getting better and clearer! My niece too loves your videos and wants to build a quantum computer one day! We both hope you keep these videos coming! :)

[@seanomurchu5048]

I cant wait for someone to get Doom running on a few lasers and sunglasses next year!

[@petevenuti7355]

As the output would be every possible path of the game at the same time you would have to tilt your head(the sunglasses) just right to see the Best final score. But that takes away all the fun of playing doesn't it?

[@ohmsanti7914]

You explain things in a way I can understand. Thanks for making this information available to the average person. You are an excellent teacher.

[@malna-malna]

I've always loved your videos and missed them a lot. you have a unique way to present matters visually very clearly while also making it fun, bizarre and a bit magical.

[@davek.677]

First video seen. I Like the content, like the voice, like ur brain and your way to be in front of a camera. Very well made.

[@vasudevans1224]

Wow I can't believe it's been years since I joined this channel! It's been a great ride and I've gone from a guy doing a bachelor's in physics with no clue about his future to a PhD student in quantum gravity with no clue about his future XD. It's been real fun!❤

[@LookingGlassUniverse]

Oh man, I know this ride well… what are you thinking you’ll do next :)?

[@vasudevans1224]

@@LookingGlassUniverse Postdoc most likely. I love physics so I'm gonna stick to academia for now. Still I'm years away from that decision.

[@ashvinjagadeesan5217]

I just took a class on Quantum computing. Its theory was very elegant(I tend to skew towards complexity theory), but watching this practical video was pretty inspiring. The most beautiful theories have the simplest experiments.

[@jochenkeilitz6599]

What a creative and intelligent approach 😊 thank you so much for encouraging people to experiment and try it out themselves

[@brandonwatsonmedia]

Your videos are always so well made. Learning made this fun takes a lot work and a lot of skill - and you have both. Thanks!

[@ernestoyepez5103]

I love the evolution of your videos. I loved your voice and your voice over animation, but these are definitely a step up.

[@noel.friedrich]

Perhaps one of the best videos I've watched in a very long time. Thank you so much! This is amazing!

[@medgarjerome]

Thank you, young lady. You are shedding "light" on quantum computing :-)

[@dc1049]

This is awesome, I'm so glad you put this together from things pretty much anyone can get and also explained it! Visual computation is so interesting to watch... idk why lol.

[@msrdanov1]

I could watch you explain anything anytime anywhere and still be interested 😊

[@jonashubotter6686]

I usually never leave comments, but this video was just way too good not to. I love the genuine curiosity that you radiate!

[@chem7553]

I love your videos! They gave some of the key tools for me to study proper quantum mechanics courses. Your explanations are also very straightforward and fact-based. :)

[@madalena4145]

I'm taking a class about this and this made it more intuitive! I learned the math, but you helped me understand the logic of it! thanks!

[@wflai98]

Thanks for the video. This experiment looks more like a demonstration on the classical interpretation on polarization of light than a quantum computer.

[@ccnbutter]

I love the Win95 UI of the animated computer screen :)

[@christoph6909]

Awesome video, thanks! Especially the explanation of the polarization filters was great. Which reminded me of a question I had for a long time that maybe you can help me understand. One famous "popular science" experiment is to take two 90degree polarization filters to block all light. Then insert a 45 degree filter in the middle and some light makes it through. The misleading conclusion is "and isn't it amazing, adding another filter should block even more light, but surprise, surprise, some light makes it through now". I always felt that this conclusion is dishonest. The polarization filter only blocks 100% if offset by 90 degrees. It's like smashing head on against a wall. Adding filters in the middle rotates the light step by step, making sure there's always a non-zero component in the new direction. Then it's totally not surprising that some of the rotated light passes through the last filter, right? It's like adding angled walls so I bounce off at an angle, changing direction each time, before I hit the last wall at an angle instead of smashing it heads on. In my understanding, the "mystery" in this experiment only comes from a deliberately misleading explanation of what the filters do. With the correct explanation, there's nothing surprising going on, is it? Do I see this right or am I missing something?

[@LookingGlassUniverse]

I think you’re right, but somehow I still find that experiment mind bending. The explanation is straightforward, and all you need is classical EM theory, yet I find it hard to accept. Like, if you add lots of filters slightly rotated, the end light can be 90 degrees from the original light. But how is this possible. Light is a force, how can a force have a component perpendicular? It’s very weird, even though it makes sense. Thinking of the polariser as a filter might be the problem..

[@laurencedarby9042]

@@LookingGlassUniverse After watching 3Blue1Brown's videos (who pointed me here), I'm pretty sure your explanation of which polarisation makes it through the filter is the wrong way round - if I understand it's the electron oscillation that propagates the light, not absorbing the light, and where the electron is restricted from oscillating in a certain direction, the photon is absorbed then re-emitted in a random direction (same as shining a light on any opaque surface. Edit: not sure this point about opaque surfaces is correct - I think it's actually that all opaque surfaces either absorb and re-emit photons as blackbody radiation, or reflect photons with the same wavelength, in a random direction (or exact incident direction in case of mirrors). But I standby by the point that the photons that do get through the material do so via electron oscillation (otherwise, 3Blue1Brown's videos are confusing and/or wrong)) And I think that explains how light gets through multiple filters - if vertically polarised light enters the filter which is at 45 degrees, the electrons still oscillate in the filter (just not as strongly as if completely aligned), and the light gets propagated in the direction of that oscillation, i.e. at 45 degrees, so the polarization is effectively twisted.

[@michaelsommers2356]

@@LookingGlassUniverse My understanding (probably flawed, since it's been almost 40 years since I studied this stuff) is that the light coming out of the second filter is a mixture of vertical and horizontal. I think it's a lot like measuring spin.

[@christoph6909]

​@@LookingGlassUniverse if @laurencedarby9042 has it right (and I seem to remember the same from the 3Blue1Brown video, but it has been a few weeks since I have seen it) then thinking about the polarizer as a filter really is the wrong model that causes the confusion. It's more of a directional re-emitter. And with the re-emission, the turning of the polarization shouldn't be a surprise or mysterious effect at all, right? Case A: Light comes at 0 degrees, polarizer at 90 degrees, light excerts zero force in the polarizer 90 deg direction. No light emitted, polarizer dark. Case B: Light comes at 0 degrees, polarizer at 45 degrees. Light pushing left-right will push the electrons along the 45 degree polymer "rails", but less strong (50%). New photons get emitted on the other side of the polarizer, but aligned with the 45 degree "rail", because that's what's emitting it. Light looks like it turned but lost intensity. Case C: Add the third 90 degree polarizer back in and do the same again and you get 25% light out. If this model is accurate, this seems straight forward to understand intuitively without misrepresenting the experiment as showing weird quantum-effects as many publications do.

[@Dievolve]

excellent video! thanks for this fascinating perspective. I don't have the time or money to get a PHD right now so this is helping me come up with ideas for building the one I have wanted to for about 20 years.

[@Wtvldoc]

Great video. At 94 I am still trying to learn!

[@LookingGlassUniverse]

That’s amazing!

[@Wtvldoc]

So nice of you!

[@infodev5222]

This is the first video I have seen that actually explains what happens inside the quantum computer instead of simply saying that qubits are in the state of 1 and 0 at the same time

[@VincentGroenewold]

What a fascinating explanation and demonstration, thanks!

[@TheFlyingMan-b3u]

Fantastic :) Now I can understand why a cubit can have two states at the same time. It has a little bit more of the up and a little bit less of the right. And when the computation is right, we can have the result we wanted in the first place. So you “set” the answer. And then try to find the right question :)

[@handyman7147]

Brilliant. Amazing skill explaining complex stuff with simple models.

[@educationshouldbefun3]

Very nicely explained. Some questions: 1. Laser light passing through a half-wave plate followed by a polarizer is a single qubit quantum computer. Is this a correct description? If yes, what exactly we are computing? 2. Why the light beams of H and V polarization are 'entangled'? 3. If we repeat the same experiment using radio waves, is it still a quantum computer?

[@shafikmestry3728]

INCREDIBLE. CONTINUE. You have all my moral support.

[@El_Diablo_12]

Glad to see you posting again. Love your videos!

[@TheDARKWOLFXZ]

Hey! This is a great video. Just wondering one thing, how big is the half waveplate that you got? and how long was the shipping?

[@NatashiaKaurRaina]

This video is truly remarkable and serves as an exceptional catalyst to ignite the curiosity of future generations about quantum computing! Your passion and expertise are truly inspiring to me. Since discovering your 'Quantum Mechanics Self Study' video, I've avidly followed and absorbed knowledge from each of your videos. In just a few days, I'll be launching my own KZbin channel, aspiring to create videos that match the caliber of yours. Thank you immensely for the invaluable work you've shared!

[@LookingGlassUniverse]

Very excited to see your videos! Can you let me know when you’ve posted (my email is in my about section). Good luck!

[@NatashiaKaurRaina]

@@LookingGlassUniverse Thank you so much for your support! I will keep you updated.

[@parrata]

This was an amazing video! It finally clicked something I've tried to understand for years! Since I started learning about the existence of quantum computers, I've struggled to understand them. At first I had to grasp that all of these quantum phenomena exists in real life, it's observable, measurable, and its effects are indeed observable. That was "easy" (the only hard part of that is just accepting that not everything behaves according to classical mechanics). Then I had to understand what the hell a qubit was, and I had to undust all my highschool and college rudimentary understanding of what the hell a spin is, among other things. That took a lot of reading, videos and talks. Now, this video helped with something I've struggled for years, and it is understanding what "quantum computing" *is*. All the explanations I've seen are quite obscure, and aren't near as clear as my old classes about how logic gates, diodes and MISP processors worked. This video changed everything. It's so easy now to replace in my head the (1) filtered laser, (2) the polymer retarder film and (3) the polarizing film with circuit including a (1) 5volt source, (2) a NOT logic gate and (3) a LED or voltmeter respectively. Linking what I know about software and electronics to quantum computing is something I never could. Now, this opens a new question, and I guess entanglement has something to do with it. What can a machine like this do that an electrical circuit using a dimer instead of a NOT logic gate can't? If instead of adopting Boolean algebra and representing 0 and 1 states with 0v and 5v measurements, it was decided to represent infinite states with all the tensions between 0 and 5v, wouldn't that have the same computing "power" to this rudimentary quantum computer? *checks comments* Aaaand I just saw Part 2 is up. I'll check it out.

[@LookingGlassUniverse]

Thanks for this great comment! It’s not at all obvious why a quantum computer with “infinite possible states” is a lot more powerful that an analog computer with “infinite states”. The difference is 2 things: it costs no extra (in terms of time or energy) to run the QC on a superposition of many states. (This is true for the analog computer as well). But you can more effectively get out information at the end. On an analog computer the end result is so weak that even though all the answers are there, you can’t read them all. On a quantum computer you have the measurement issue, but sometimes you can succumb that by not measuring the state in the 0/1 basis directly but by measuring in another basis

[@GarryBurgess]

You're so smart that every time I watch your videos I feel inadequate as a human being.

[@LookingGlassUniverse]

I feel inadequate all the time

[@larsbitsch-larsen6988]

You are good at explaining difficult things. Thank You.

[@kingshukcs]

Your presentation is beautiful!!

[@pharmdiddy5120]

Calculations on a home made quantum computer? Woooooow can't wait :)

[@mailong.botega3040]

The explanation using lined paper was very good!

[@jamesdutton9835]

I like these videos. It demonstrates that voyage of discovery in science that is so important for learning science. Note on safety, although I am sure you are using Class 1 laser pointer which are safe without needing protective eyeglasses, people watching this are going to want to repeat the experiments themselves, and if you buy laser pointers from the internet they might say they are Class 1, but in fact be far more powerful. So I think wearing laser protective eye-ware in videos like this would set a good safety example.

[@eigenchris]

Very cool that you were able to buy some spinors and SU(2) matrices for building a quantum computer. :-)

[@LookingGlassUniverse]

Yeah, weird they were just selling them online

[@VR_Wizard]

That's what I call a cliff hanger. I guess I need to subscribe now to see the second part 😅

[@Wielorybkek]

really cool stuff! amazing to finally see an example of how quantum computers work, the usuall pop-science and sort of hand-wavy way of explaining doesn't really makes it any clearer. good effort!

[@OuterSpacePeace]

I got caught up in stalking your channel to learn more about quantum mechanics/physics/engineering when I’m in a general chemistry class learning about surface tensions… I’d much rather be here.

[@br3nto]

Wow great real world demo!!!!! Very easy to understand and follow

[@gedaliakoehler6992]

Great video. What kind of computations were you thinking to do with this setup?

[@Voseph]

When the light passes through the polarizer, why do the electron jiggles “absorb” the wave instead of creating their own wave, like the glass electrons in the “does light slow down” video?

[@Kroogles]

I am genuinely grateful you make such a brilliant effort to share your experience and wonder of nature with us plebs.

[@jamesmcclain5005]

I can hardly wait! Good demonstration!

[@ryanwaldt1710]

Fantastic, also I enjoy that you go in to how and why it works, but you also do the real experiment to show it. As a question do the too light beams hit the back stop at the same time after being split?

[@LookingGlassUniverse]

No, one beam really is slowed down a bit! Plus the paths are different lengths

[@ryanwaldt1710]

Thank you for your response, another question if you do the same type of experiment in a vacuum and the beam is split with one beam going through a material that speeds light up and the the other beam just in the vacuum, will the two beams hit the back stop at the same time?

[@NWDestroy]

That was a fun video. Thank you for making it!

[@pazitor]

Love to see brilliant young people on YT. Thanks! BTW, this video took _a lot_ of work. Thanks for that, too.

[@ivanalyoshafyodor]

It's a bit crazy how divorced physics education is from hands-on experience. It would be nice to play around with the phenomenas we're studying on the blackboard every once in a while.

[@bobthemagicmoose]

I would disagree! I’ve done a lot of education and the subject that got the most demonstrations was definitely physics! Especially the broad strokes intro classes. Once you get into the more extreme stuff it’s a little harder to play with the material without really expensive equipment I think.

[@ivanalyoshafyodor]

@@bobthemagicmoose That's a fair point.

[@valerylabuzhsky1532]

If you just combine two lasers you won't get superposition, you'll get a "mixed" state of two. So you need to somehow sync the lasers or split the ray of one.

[@LookingGlassUniverse]

No, you do get superposition. If you cross two laser beams for example, you get interference at the intersection

[@valerylabuzhsky1532]

@@LookingGlassUniverse imaging having two sines whose period will be almost the same. Their phase difference will slowly drift one relative to the other unpredictably, as their phases are not constrained by anything. So every time you get a different superposition. To get the proper superposition you need to sync the phases.

[@captainjj7184]

Amazing... now I can _Actually_ understand how it works... hope you excell in what you do - and thank you so much!❤