this video is made possible by kiwi Co more on them later can humans see Wi-Fi no definitely not otherwise you're evening browsing habits would have blinded half the neighborhood by [Music] now Wi-Fi is the name that we gave the tech priest magic that allows us to download cat videos literally through the air but what is it really what's coming out of the magic pixie box that we plug into the special wire in our house the short answer is light or more accurately a type of electromagnetic radiation called microwaves and yes I do mean the same
kind of microwav that you use to reheat a day old burrito this is why in the old days running a microwave could mess with the internet connection if the oven was leaky it would broadcast random noise at the same wavelength the Wi-Fi router was trying to use microwaves like all electromagnetic radiation have a frequency that they oscillate at for example an FM radio station's emissions are around the 80 to 100 gz range a Wi-Fi router or your kitchen microwave oscillate at about 2.4 GHz and visible light is all the way up at 450 to 750
terahertz while our sad caveman eyeballs are limited to a very minimal patch of the electromagnetic spectrum light is light so in theory you could build a camera that could see almost any part of the spectrum for you and we actually already do this for microwave signals our universe is filled with giant things in space that scream out microwave frequencies pulsars nebula gas jets quazars and more if you build a really big antenna and then pick a frequency you're interested in and wave it around measuring how much radio power you measure in each location you can
build up images of the cosmos we've even used this to take a picture of a black hole now this is called radio astronomy if we had a tiny radio telescope and tune it to Wi-Fi's frequency theoretically we could do the same thing but take a picture of all the Wi-Fi em in an area to that end allow me to introduce xj9 while it may look like the sort of thing that would give a rathon executive a stiffy it's actually our latest iteration of a radio telescope though it does still feel a little intimidating when you're
being scanned xj9 is what happens when an actual engineer with a budget designs the radio telescope instead of a broke scientist it's got proper geared stepper Motors belt drive nice 3D printed parts and a proper flat bearing and of course the head is swappable allowing us to sub out the antenna for different experiments compare xj9 to cogsworth the first iteration of a Wi-Fi camera I built many years ago held together with spit duct tape and prayers to the Deep old ones he was designed and built entirely by hand out of whatever random crap I happen
to find lying around but through all that Jank he held together just long enough to take a couple of pictures of the Wi-Fi router in the workshop and find a bunch of my neighbors routers by scanning the building while his efforts were Valiant cogsworth was eventually taken behind the wood Woodshed and his head now lives on my wall as a science trophy in his stad xj9 is ready to step in and do all the things I dreamed cogsworth might when I made cogsworth I had originally intended to open- Source the design but honestly it was
so bad that I just couldn't stand to afflict the world with more of him but xj9 on the other hand will have all of her build plans on GitHub xj9 is largely 3D printed but we did have to laser cut a few pieces for the Bas this means that if you want an xj9 for yourself you're going to need a few specialty tools but you won't need any tools to assemble this next part this is one of the amazing learning crates from the sponsor of this video kiwi Co if you haven't heard of them before
kiwo is a subscription service where each month you get one of these delightful boxes of fun and learning inside this particular box was an incredibly well-designed set of pieces and instructions to build a customizable and adjustable Tippy tilt Maze Game kiwi's crates are designed for kids but I was shocked at how much fun I had putting this together I wish all of my science projects were this much of a joy to assemble the instructions made everything super easy to follow and the kit packs so many different concepts into one set also it was quite the
site watching every single member of my crew all grown adults get distracted at some point in the day playing with the finished maze so if you have kids or maybe just want to get the perfect gift for your niece or nephew this really is the gift that keeps on giving all of my favorite toys as a kid were sets that you got to build something that was usable later that you get to keep playing with and with kiwo clubs you'll get a new box of delight every month and there's something for every age group in
interest I especially recommend the kiwo labs sets as they're focused on science and engineering and is the lineup that the tippy ma is from all you have to do is choose one of the five clubs Panda Sprout Labs world or Studio depending on your interests and then pick a payment schedule and wait for your first crate to arrive so after this video head over to kiwico.com thorium or use the coupon code thorium to get 50% off your first crate now back to the rest of the build xj9 or Jenny to her friends is fundamentally an
ALT asmith robot meaning it can either tilt its face up and down or rotate around its base to point in different directions since her face is removable we can swap out the antenna depending on what frequency we want to look at though that's not to say she has to have an antenna for her face a knife also happens to fit nicely so she can help out in the kitchen and terrify my dinner guests or I can strap a laser pointer on here and use it to distract the neighbor's dog while I rearranged their Furniture to
make them think their house is haunted anyway an antenna is for the most part an inert piece of funny shaped metal so to turn the radio waves that hit the antenna into usable data we're going to be using a software defined radio or SDR these are digital radios that connect to a computer and can be tuned to Whatever frequency we want we tried two different models a hack RF and a lime SDR and found that the hack RF was more reliable for this to take a picture what we're going to do is move the antenna
around and at each location record the intensity of radio waves we receive just like radio astronomy by plotting each intensity as a pixel for each location we can build up an image as we scan the area we can either do a big wide scan to take a full image or we can just do a simple Arc If all we're interested in is the direction the signal is coming from so we set about trying to take a picture of our router which seemed like it would be a simple task after all cogsworth was made literally out
of garbage and managed this on its first go we'd also learned from last time and had simplified the code so that as soon as the scan was done out popped an image and the results were crap if anything it looked like there was a dead spot where the router was and good signal everywhere else so we tweaked the code and ran it again taking more samples this time at each step so that way we had a better average of how much power was being received and again junk we TW tweaked and scanned and tweaked and
scanned literally for days and every time junk if we tried just measuring the signal to noise ratio we got signal in a weird spot if we directly measured the power we got signal in a different incorrect location we spent days waving the antenna around and tweaking things it was honestly infuriating I was starting to feel like that scene in Iron Man Tony Stark was able to build this in a cave with a box of scraps in the process of figuring this out we started to suspect that the walls were the problem and I know that
sounds insane but bear with me most walls in a normal Canadian Residential Building are framed in wood than covered in drywall or sometimes they're made of brick this means that they are basically transparent to Wi-Fi which is why you get relatively good signal throughout the house but not all buildings are made the same and not all materials are transparent to Wi-Fi I mean think about it Wi-Fi and your microwave are the same frequency why does one stay inside the box and one spreads out over the whole area the short answer is metal or anything conductive
But Metal being extremely dense on top of being conductive certainly doesn't hurt a microwave oven is well an oven it's a sealed conductive grounded box so the microwaves Just Bounce Around inside our building for reasons that are only known to the builders and the old gods was built using weird steel studs instead of wood I was contemplating making a in the wall to demonstrate this but my landlord advised against it not only does this make Renovations a nightmare it also makes the walls actually kind of reflective to Wi-Fi signals and a Shop full of large
bits of metal equipment cables and piping could feasibly be causing all kinds of Reflections so we're detecting not just the direct signal from the router but all the light bouncing around the room so in an act of desperation to figure out why this wasn't working we set the router up in a tree and just scanned that it took a little bit of finagling but we finally got something that made sense big bright spot right where we expected it and we can scan off to one side we see that the spot moves accordingly perfect this is
exactly what we wanted okay great this is solved right nope spinner around to name at the normal router again and once again we don't see it and Dad insult to injury when we brought Jenny to the place we originally tested cogsworth which is definitely made of wood she couldn't see that router either this left us scratching our heads and confused all the while days are flying by and this video was becoming dangerously overdue and then it clicked the program we're using for the radio side of this is called gnu radio it allows us to make
these cool flow graphs that let you control the radio signals and the incoming data and process it immediately buried in one of our code blocks was a setting that was throttling the gain based on how much signal was coming in so instead of getting a true power measurement it was trying to compensate in dim areas which completely ruins the experiment we also found that routers are actually on the whole pretty dim light sources while they can transmit a lot they usually don't and instead are so efficient that they only need very short bursts to keep
the cat videos streaming to your phone so to make our lives much easier we had every member of our crew run a speed test on their various devices while we were taking a scan and sure enough with all of those tweaks a scan finally showed the router properly I'd been getting worried that we were going to end up having a remodel xj9 into something rathon might actually be interested in just so that this project wasn't a huge loss that does finally bring me to a bigger why why did we build xj9 in the first place
well beyond the obvious stated reasons and because it seemed like a fun idea Jenny was meant to be a platform for bigger and more interesting projects what we've just demonstrated is an incredibly simplistic form of passive radar with Jenny we can see where the router is but it's like taking a picture of a light bulb what would be far more interesting would be to use the Wi-Fi as a light source to illuminate other things so we can see them basically using Wi-Fi to see through walls instead of seeing Wi-Fi through the walls and we should
be able to use Jenny to make 3D maps of an area by just picking the right light source now with the bugs worked out of the system and a reliable stable and repairable platform to work from we can finally tackle the hard parts and the radio astronomy I mentioned earlier is also on the table in another very old video we used the radio telescope like this to take a picture of the geosynchronous band of satellites that's the ring of satellites that orbits at just the right distance to appear as though they're always in the same
spot in the sky think communication satellites TV satellites weather satellites that sort of thing but with Jenny we should be able to take a much nicer picture and see even more satellites and beyond that we can find all kinds of other cool stuff in space and on land by just choosing the right antenna and amplifier so be sure to subscribe so you don't miss those videos but to finish off this video we took one more scan and got a very cool result when we look at the graph we see a strange shape if I take
it into Photoshop I can do a little CSI zoom and enhance and when I do we see a coupon code that's right it's holiday season and our store is bursting with new and exciting items and if you use the code Jenny you'll get 10% off your order not only do we have allnew don't build the torment Nexus apparel we also just added the first of a new line of designs we're going to be releasing this is the first of what we're calling our science tarot series it's currently available as a poster but will be available
on apparel soon and of course we still have our other handmade posters and catalog of amazing designs to show off your mad science flare so head over to the thought emporium.com today and while you're there be sure to sign up for our monthly newsletter to get the latest news from our house of man-made Horrors we're getting ready to add DNA and other Biologicals to our store so you'll be the first to know when we do and of course before we go I also need to say a huge thank you to our amazing patrons and channel
members that make these videos possible patrons and members also get access to our supporter Discord so if that's something that interests you or you just want to support our work there's some links below but that's all for now and we'll see you next time
