Part 2 is up: kzfaq.info/get/bejne/qq6WetiUrdqwoaM.htmlsi=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.

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

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

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!

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.

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 :)

I really appreciate how you explain complex things so well

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!

"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.

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

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.

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!

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

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?

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

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

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.

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 💡

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.

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"

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!

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!

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

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...)

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.

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.

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

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!

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!

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.

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.

Glad to see you posting again. Love your videos!

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

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?".

Love your videos. I'm so glad you're back!

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

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

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

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

Your presentation is beautiful!!

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! :)

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

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

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. :)

I can hardly wait! Good demonstration!

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

Brilliant. Amazing skill explaining complex stuff with simple models.

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.

What a fascinating explanation and demonstration, thanks!

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

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 KZfaq video makes it click for me

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

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

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!

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

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).

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

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!

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!

Wow, that's so cool! Thanks for all the effort! ❤

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

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

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

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

INCREDIBLE. CONTINUE. You have all my moral support.

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.

The explanation using lined paper was very good!

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.

Thank you. Another informative video. I very much appreciate the efforts you put into these videos

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.

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.

This is so far above my head, and I loved every second

I always learn so much from this channel

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.

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

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

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

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!❤

You are good at explaining difficult things. Thank You.

This is so amazing!! Thank you for explaining sooo soo much!!

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

This is fascinating! Can't wait for the next video.

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

Thanks for this! Fantastic. Hoping to learn more.

Informative and educational, thanks for posting

ooh, I love this new channel. Very nice!

Wonderful and informative video.

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

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

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?

i am eager to see it 7 time more and grow with it, but thankful

Invaluable tu aporte, muchas gracias

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.

Loved the video...this is a very underrated channel

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

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

I love the presentation.

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

Im doing quantum computers for a EPQ and this video has been really helpful. Thanks!

Initially I am very impressed by the art