ALL of Wikipedia in One QR Code? 

This would take vsauce twelve minutes to explain and a tangent on the history of cameras.

Hi HANK! I'm a remote sensing, computer science, geospatial nerd. I felt it necessary to inject some information on this topic. 1: You can compress large piles of text with amazing efficiency 10:1 could easily be achieved. 2: Your size of Wikipedia value is not a hard number, it was in fact calculated from averages. (It should be pointed out) 3: Most, if not all sensors that image terrestrial objects use "Push Broom" approach to imaging. (IE they work like a flatbed scanner. So in essence you only need to make a sensor with a spatial resolution in one dimension and provide it with a large enough on board buffer and down link speed to clear the buffer. ) 4: QR codes are binary glyph, in other words black or white. This means you can cheat and image in the UV spectrum while still using black ink so long as you are imaging it with sunlight or a UV light source. 5: You are imaging a binary glyph, your radiometric resolution can be in the 4 bit department and still account for vignetting (don't totally quote me on that one image scientists) recap, you would need a sensor with 2.7 million pixel width that was sensitive to UV with a ground sample distance bellow 1 mm and a radiometric resolution of roughly 1 to 4 bits in orbit around the moon at roughly 1.35km (Orbital speeds may cause issues with blur). Oh and it needs about 10 Mb of buffer space/throughput.

I haven't been this excited about math since...ever

I love how Hank's phrasing went from "we could" to "we are going to have to."

You're the guy we read about in junior high math class, aren't you? The guy with 23 watermelons and 17 oranges.

I love how Hank's American, but uses the metric system.

Hold the phone. Wouldn't the Wikipedia you had coded be out of date by the time you could read it?

Physics nerd here, and as far as I can tell all of that was correct... Wave mechanics are cool :D Oh, and thanks for doing this, I enjoyed it a lot. It sort of reminds me of XKCD What If?, but in video form and with Hank, both of which are lovely.

apreture ok this is the type of thing that we do and in a thousand years an alien civilization finds it and is like "what the fuck is this? were they worshiping some kind of square gods?"

Three things: 1. This entire video melted my brain in awesomeness. 2. This is the most math I've ever seen used since I was in college. 3. Now I want to see this QR Code made one day.

Bonus assignment Hank, figure out how much you can shrink that QR code if you have a data compression algorithm capable of shrinking Wikipedia down to the Shannon limit.

Y'know, this is what I subscribed for. Not 95% flashbacks/humanitarian episodes. I know that you don't have a lot to talk about after Crash Course, SciShow, and everything else, but think of SOMETHING. This is great!

So here's my follow up question to your scenario. Considering the growth rate of megapixels per year in the camera industry (military, consumer, scientific, or otherwise) and the growth of data per year of Wikipedia. On which year will it be possible for this to happen?

"Wait! Stop! Hold Everything! Clear out everything from Sea of Tranquility grid 14583x1113344. Someone just edited the Skeletor article!"

Pretty much a vsauce piece. Not complaining! I love these kind of questions.. and I love the math that comes with it.

I absolutely love these "let's be nerdy for a minute and figure stuff out" videos! :D Of course, if aliens were to scan a QR code and learn about us, we all know they'd only need the article on Nerdfighteria :P

Holy crap, watching you figure this out is giving me a headache

Perhaps instead of using a QR code, you could use another (or create another) code that has more information density. The paper wouldn't need to be as large and of course it would reduce the requirements needed for the camera. Just a thought. Have a great day!

HankSauce.

This is literally my favorite 'Hank goes Nerd' video ever. I don't know, this is weirdly calming to me

The other issue you'd have is that Wikipedia is not a finite amount of data, it will continue to grow in the intervening months and years that it takes to print, layout, and create the camera technology necessary for all of this. You'd never stop printing.

I have been really sad lately, and I didn't really feel like I fit in anywhere. But a few months ago I came across one of Hank's joke videos. I started really getting in to the other videos. I feel like I have finally found a place where I belong. I am not laughed at for my nerdy personality, I am accepted. Hank and John have changed my life forever. Thank you.

This was really interesting. Also, based on this video, your hair wins the survey question of which of the two of you has better hair.

Very interesting to think about! The one issue that immediately comes to mind is that by the time the necessary "future technology" is developed, the size of Wikipedia will have grown even larger in size, which in turn means that the QR code taped to the moon will need to be even larger. To account for this growth, we would need to overcompensate the number of sensors included in the future camera design to ensure that by the time we go to scan the future QR code, our camera can handle it.

Yay! An American using the metric system!

I didn't completely grasp everything but I love when people get nerdy and enthusiastic about figuring things out.

More of these please.

You made me smile within 20 minutes of hysterical sobbing due to a complicated tooth ache problem. Because its exactly the kind of problem that I like to think about at night, type not specific. How to do some absurd thing that I am not going to do or even really needs to be done. But solving it makes me happy. And frankly - THANK YOU for making me smile. It was a really really bad day until I watched this.

Waiting for michael from vsauce to show up.

Hank just took me to school...and I actually enjoyed it!! If he would have been my math teacher all those years ago, I probably would have been a lot more enthusiastic about and more inclined to learn math.

could you encode the whole of Wikipedia on a standard QR code using compression of some sort, what if you WinZip'd first?

probably my favorite vlog-brother video ever. so much math. even more science. and so much physics. i can't even put into words how happy this video made me feel. that someone else actually thinks of these ridiculous questions and even goes so far as to do all the math and research to make an answer. Hank (or John or anyone else who's reading this) i want to thank you so much for not only everything you do but also helping me on my path to except my crazy nerdy self. god i just love this video!!

Oh wow. It's like when I determine what the energy of the LHC was in terms a normal human could understand, and I calculated that 1 cubic metre (or was it a kilogram, i can't remember) of hydrogen gas accelerated by the LHC would have more kinetic energy in it than a fully-laden Maersk Triple-E class container ship moving at Mach 10! A crashing, hypersonic mega-containership sounds a lot more impressive than saying 14 Teraelectron-volts, doesn't it?

the fact that you said all this stuff under 4 minutes is just... awesome. you're awesome.

Hey Hank, have you actually tried to pass on this question to Randall Munroe yet? I'd really like to see him publish his own study on the subject, and maybe it could make its way into "What If, volume 2"! (Hint, hint.)

My favorite thing about VlogBrothers is that they don't capitalize unimportant words in their titles (like articles and prepositions). My second favorite thing about VlogBrothers is THIS VIDEO!

Oh, and by the time you have the technology to make this possible, there will be new articles on Wikipedia (new notable people being born, new events taking place, new research and technology, etc) so you will need an even larger square for the QR code and you might need even better technology, by which point there will be new Wikipedia articles, and so on.

If Hank was a college professor, I'd sit through his lectures everyday. He makes things so easy to understand! THANK YOU, HANK!

Wow, I am so early to this video... Not really surprising since I basically live on RU-vid though

Love watching Hank Nerdout ... this vlog made me smile!

I shudder to think of the consequences of asking such a question. In other words, your nerds were so preoccupied with whether or not they could that they didn't stop to think if they should.

Oh my god, I love how excited Hank is and how excited he makes me in the process.

You lost me at QR code

I love videos of hank being hank especially since math is amazing 😊

So is this being funded by NASA?

Thank you very much for featuring my video!

And even after we do this, there will still be a lot of incorrect information on it.

This is amazing. I'm definitely bookmarking it for later to show my Mom. Math, science and space combined with a weird / quirky question is right up her alley.

We need to figure out how to download all of Wiki into our brains like they did in The Matrix movies!

This is so vlogbrothers. And it's the kind of vlogbrothers that makes me so happy. Thanks Hank!

Lol.. Why do you think of shit like this? WHYyyyy

I feel like this is the exact kind of thinking that leads to some truly great discoveries. I think that most, if not all, of humankind's greatest discoveries came from nerds going, "Hey, can we do this absurd thing that nobody else even wants to do, because it seems kinda useless, has no bearing on daily life, we're doing fine without it, and nobody else can understand why this is so fascinating? Yeah...yeah, we can. Let's do it!" And while everybody else is trying to understand _why_ the nerds are doing the thing, the nerds do the thing, and at some point after the thing is done, it ends up making lives easier in a way nobody could ever predict and soon becomes a huge part of daily life that everyone takes for granted. I'd wager even the discovery of how to make fire was done in this manner by some curious cave-nerds who started on a train of thought much like the train of thought exhibited by Hank in this video.

Or you could store the link to the wikipedia page on the qr code...

The fact that you ponder questions such as this one and to their fullest extent is one of the reasons I love you, Hank. DFTBA.

Nice video! Another solution (I read this in a book a while ago): assign each possible character a 3-digit number and make a huge number out of that. Put a decimal point in front of that huge number, and make a mark on a rod so the space to the right/left (whichever you choose) of the mark is that amount of the rod. So, if it was just letters, if we were encoding "cat", the mark would be put at 0.003001020 (out of 1) of the rod.

got to say that was the best 4 minutes of science and photography ive ever heard in decades :p thank you Hank for making this video :D

I love these types of videos where you take an idea that we may never really think of and apply math to it

omg i love this! I really enjoy listenng to people who talk about math and find out a resolution for it

This is a phenomenal video, Hank! I love the random questions that you have that just need to be solved!

I love this video because Hank just throws whatever science at it in the attempt of solving the problem. More!

I love that you still say week-ee-pedia. John clearly proved that a girl robot voice pronouncing it in that way is not sufficient evidence to change from the standard pronunciation of wick-ee-pedia. :P

This is probably the wierdest and most enjoyable vlogbrothers video yet. i applaud you on your success

Dear god, I thank you for creating people that can get into math the way hank and many others do.

hank, I love your nerd outs, they're simply amazing

You always make math and physics sound exciting. These are the fundamental

It's still nice to see people getting this excited over, well, anything. And the entire thought process that goes on behind it. See you next week, Hank

Just voicing my opinion. I love videos like this! They make me really love being a part of the community

As you yourself point out, the answer is technically "no," since the maximum data capacity of a standards-compliant QR code is 31329 bits. Since we're not adhering to standards, we could find a number of ways to encode the information in a more information-dense visual format, such as using a wider variety of colors to represent a non-binary information system or using triangles rather than squares to fit two bits into the same space as a square. Even without moving beyond binary squares, 2mm (or 2.0e-6 km, since converting is bad and exponential notation is good) squares seem pretty arbitrary and it seems like we could print the QR code much smaller without losing the possibility of resolving the individual squares with an appropriately sized space-camera in an appropriate orbit.

Hank, I really appreciate you doing the distances in km. For once I can just listen. And even with my high school physics I can say this sounds at least pretty close to correct. Have a fun rest of the Day

I love when you ask and answer questions that nobody else thinks of!

I could use you as my stats professor right now! I might could actually focus long enough to understand math if you were explaining it! I was surprised at how much of that I actually understood! Way to go:)

This is absolute bonkers! Probably the best, video break down I've seen by far.

This is the nerdiest thing I've watched all week. Nothing negative, just an observation.

I am neither a mathematician nor a scientist but I really enjoyed watching Hank geek out about nerd stuff :D

So basically a vlogbrothers episode of xkcd's what if. Enjoyed this, wish I had the time and inclination to math this hard. You should do more of these.

Yay for Math! Awesome to see a vlogbrothers video with math. Also, for both you and John, I just wanted to say that I watched crashcourse in my college sociology class! no one knew how much of a nerdfighter I was... When the teacher asked if I knew who John and Hank Green are I was like yea. yea. definitely yes. like really. you have no idea.

Woooow I love watching Hank nerd out so much - his curiosity is contagious

Another Vlogbrothers video, another answer to a question I never knew I had. My favorite kinds of questions.

I love you, because these questions are exactly the kind of questions that are the most fun to figure out for me too.

I really like that you come up with weird ideas and share them. Thank you. Keep it up.

I didn't understand any of this too well, but I have to say your enthusiasm for it is awesome.

Ah! This harkened back to the old 2.0 videos and it makes me SO happy.

This is one of my most favorite vlogbrothers videos ever!! Science nerds unite!

Thanks for making me interested in physics again Hank!! Wave mechanics was boring to me but not anymore yay!

This in one of my new favorite videos, just because he actually worked the whole thing out. Hank, never change.

I really enjoy your videos like this where you take a question and really try to answer it (such as what you did with the adding machine). Not sure if you'll even read this, but on the off chance that such positive feedback matters, I wanted to provide it.

What size would the individual squares in the QR code be? Could you theoretically make them so small you would have to read the code with a microscope? Could you develop a camera that takes a panorama-esque picture so you just have someone in a golf cart going across the code and back however many times would be necessary? God I love silly science like this. Thanks Hank.

MATH AND SCIENCE TEACHERS OF THE WORLD! Please make this into a bonus question on your next test...

I love how excited hank is about math science

Amazing! I always love doing this kind of thought experiment on my own.

BEST IDEA EVER!!! LETS PRINT OUT THIS QR CODE FOR HANK!!!! we probably cannot get it to the moon-- yet! but we could print it out and send it to hank!!!! NOTHING could go wrong with that plan!!!

My suggestion(hope I don't sound like an idiot) is that divide the QR code into small pieces and take pictures of them separately and then use a supercomputer to join them together. The QR code is 729km^2 and It would need a good processing device - such as the supercomputer- to join it together.

This reminds me of an XKCD What-If, and I love it. Please do more!

When you love math so much you actually do it for fun.

I always hear and read comments about Hank being so engaged in so many projects (Vidcon, SciShow, Crash Course, his own youtube channel, this tumbler, DFTBA records and so on) and how much time this must take him. After watching this video I don't think that is the case.

Hank is the only person who can make QR codes interesting.

This is the first time I used the unit circle my high school math teacher had me memorize to check someones work since I finished college. Been a little over 7 years since I've even though about it and that information is still stuck in my head some where.

This video is amazing. It reminds me of What If, as well as this book that I'm currently reading, The Unimaginable Mathematics of The Library of Babel, by Bill Bloch. It takes this short story by Jorge Luis Borges about a theoretical near-infinite universe-sized library containing every possible book & analyses the details in a fascinating mathematical way. For a big mathematics & literature nerd, it is perfect. As is this video. Good job, Hank. So Long & Thanks For All the Fish, Lawrence Calablaster

Make it a rectangle instead of square and you could roll it up like a ribbon and run it through a feeding scanner to read, eliminating the need for inventing a new computer and simultaneously making the data easier to store. My daughter has an easel with a giant roll of paper for drawing on that is probably half a meter in width. To print the code you would only need one of these rolls that is 1.5 million kilometers long extended, but all rolled up assuming the paper is like half a mm thick, it would be a cylinder of around 482 cubic meters which would fit in a large but not unreasonably large safe. Good video, Hank. Very Vsaucey.

This video is a lot better than I thought it was from just the title.