There is something special about a secret knock. It gets you into secret super villain meetings and is a surefire way to test for rotating bookcase passages. Secret knocks usually work with an intimidating drug lord and for policeman listening at the door for the correct pattern of raps.
The big fireworks day is almost here, but most of you are limited in what you can do when it comes to celebrating the Fourth of July with a bang. Unless you live in a dry area prone to wildfires, one type of fireworks you can probably still legally buy are sparklers.
Whether you've got an itch for a mini-flamethrower, a shower of burning sparks, or a exploding ball of flames, these little fireworks-producing lighters may be the answer to your pyrotechnic cravings!
Whether you're in an airport, restaurant or waiting room, the insidious grip of televisions on human life is omnipresent. Sometimes it's nice to talk to other human beings while looking at them directly—actually hearing what they have to say.
I love making beeps and bloops with the Arduino pitches library, but sometimes archaic 8-bit tunes just don't cut it. Whether you want your robot to terrify your enemies with a demonic synthetic voice, you just need a pocket boom box on the go, or you want to a miniature guitar amp, a simple LM386 amplifier can crank up those signals loud enough to play through any speaker.
If you've got a birthday party to plan for a young budding scientist coming up, a little nitrogen should do the trick. In this project, I'll show you 10 "super cool" tricks with liquid nitrogen that you could try, but probably shouldn't!
Carving pumpkins into creepy looking jack-o'-lanterns for Halloween can actually become fairly boring and tedious if you're doing the same thing year after year. This time, jump into a whole new realm of Halloween fun with some exploding pumpkin faces! I like to call them blast-o'-lanterns, but can call them whatever you want.
Home chemistry is great, but what happens when you forget to label your chemicals? How do you know if you turned a clear glass of ammonia into a clear glass of unobtainium? Chemists have a tool for just that.
To make soap, you need fat, and if you've seen Fight Club, you're probably well aware of where soapmaker Tyler Durden got his fat from. Liposuction clinics. If you're not willing to go that far for a perfect bar of homemade soap, you can just use some drain cleaner and America's favorite food instead—bacon!
Just about every household gadget we own runs on 1.5 volt batteries of one size or another. Wouldn't it be great if you could reuse all of those dead AA, AAA, and D batteries after they've passed on? It turns out you can make a simple circuit called a "Joule Thief" to reanimate the undead flesh of your deceased batteries and create a zombie battery.
When it comes to melee combat, two swords can definitely be better than one. Throw a stun gun on top of that and you've got a seriously terrifying weapon. That's exactly what YouTuber jonathanj9969 did with his homemade double-bladed stun sword.
I loved the Gold Rush unit back in third grade. We went up to the American River and panned for gold, and my panning skills balled above all. I got like three tiny pellets. Of course, it was all fool's gold, aka pyrite, but it was still pretty legit. And this was before wearing gold chains was cool—or not.
Here is how you can build a frame for your MEGA SOLAR SCORCHER in under an hour, and for less than $8!! This is effectively a 4 foot magnifying lens that concentrates insane amounts of heat from the sun. What would you do with all this free solar power?
In this project, you'll learn step by step how to modify a microwave oven transformer into a high-current device that can pump out 800 amps of electrical current, which is enough amperage to melt metal.
Not many people fly kites anymore. Most of us don't have the patience or attention span because, let's face it, we're used to smartphones and other gadgets that have games and apps galore to entertain us. Heck, you can even fly a kite on them if you really want.
Eavesdropping from a distance can be tricky because it usually requires some sort of bug or transmitter. It's easy to transmit audio through lasers, but you can also use lasers to build a microphone that picks up audio from a distance.
If you're the kind of person who frequently does science experiments at home, you probably have a hot plate. But if you're more of an occasional amateur scientist (or just don't want to buy one), it's much easier to hack your own.
Rockets will always be cool no matter what age you are, and building your own rocket is even better. If you have an iPhone that you aren't afraid to blast off into the sky, then you can try and build your own iPhone Rocket to record and analyze flight data, like Byte Works did. The list of parts is a little hefty, but their blog provides you with all of the information you need to make sure you have everything.
With the microwave oven transformer (M.O.T.) salvaged in a previous project, a simple electrical circuit can be rigged to get high voltage arcs to fly outward and upward along a "V" shaped spark gap.
In a previous project, I showed how to build an electrical Jacob's ladder using an old microwave oven transformer (MOT). In this project, I modified the secondary coil on the MOT, which converts it from a high voltage/low current device into a low voltage/high current metal melter!
Ever wondered what the inside of a burning rocket looks like? Well, thanks to Valve engineer Ben Krasnow, now we know. He built a homemade hybrid rocket engine that's see-through so you can actually watch how it works. And even though it's probably a really bad idea to try this at home, he made a video so you can build one, too. Just don't say I didn't warn you.
You can do a lot with liquid nitrogen, including freeze and shatter gummy bears, make homemade Dippin' Dots, and scare the crap out of your friends by dipping your hand in it! If you can't get your hands on any, you can even make it yourself. Or, if you want to try something a little more destructive, you can use it to make an explosion and send 1,500 ping pong balls flying.
You've made a bottle rocket (or ten) and a sparkler bomb, and now you want to put those empty plastic bottles to a new pyromaniacal use. With a little rubbing alcohol and a match, this video by io9's Esther Inglis-Arkell will show you how to make your own homemade rocket booster in a bottle.
It's September 1st, 1859, and the Earth looks more or less like something out of an apocalyptic movie or Sci-Fi novel. All communications have failed, it's so bright outside at midnight that people are getting up and making breakfast, and people all over the world are seeing auroras. The solar storm that produced the electromagnetic pulse and caused all this mayhem is known as the Carrington Event, and storms like it happen about about once every century.
Old newspapers come in handy for many different uses around the house, from birdcage liners to shipping cushioning and even a little fish cooking. But for backyard rocket scientists like Markus Bindhammer, they're more suitable as an ingredient for rocket propellant.
War leaves a lot of stuff behind. Torn families, delegitimized institutions, mass graves, and unexploded ordinances litter the post occupation landscape. Whether or not you have driven the imperialist out, or are still in the phase of armed resistance, you will need the ability to safely diffuse bombs. My bomb defusing Silvia-bot can do it all. She can catch grasshoppers, cut wires, collect samples, tase enemies and even play chess!
Looking to transmit some super-secret audio communications to your other spy buddies? A laser is the perfect tool for getting your sounds heard from a small distance—without anyone intercepting them— even if it's just a cover of your favorite pop song.
Collodion—it's one of those things that you probably never heard of before, but have actually come across many times in life. It's used for all kinds of applications, from photography to special effects, and it even has a few medical uses. So, what exactly is collodion?
In 1958, Patrick Flanagan invented the Neurophone, a device patented in 1962 that allows radio signals to be picked up by the human nervous system. The skin is the organ that receives the signal, converting it into a modulated molecular vibration, which the brain interprets into sound. Basically, it gives one the ability to 'hear' through the skin, making it sound like the audio you're hearing is actually in your head. It's kind of like having headphones in your brain.
Fool your friends, scare your cat, play a game while also admiring your physique! This "magic" mirror lets you do all that and more by letting you display words, pictures, videos, and even some games—all controllable through a mobile phone.
One of the most annoying things about summer is mowing the lawn. Depending on how big your yard is, it can mean spending hours out in the hot sun while you could be doing something a lot more fun like watching the Olympics or making giant soap bubbles. Reclaim your summer with this remote control lawn mower that does all the hard work for you.
Have you ever wondered what sort of microscopic critters are floating around in your water? Well, you can find out with just a few bucks worth of materials and a laser pointer. Really. That's all it takes to build your very own homemade laser projection microscope, aka a water drop projector.
Want to make your own soda or maybe just bring a dull one back to life? Homemade sodas don't always live up to the store bought ones because they can taste flat by comparison. This quick and easy method makes super fizzy drinks with only four ingredients.
Magnetic ink is generally used by the banking industry to allow computers to read information off of a check, but that doesn't mean you can't have some fun with it. The guys over at openMaterials have figured out a great recipe for a DIY magnetic ink that you can use for an interesting art project—or just to mess around.
Nothing to do this summer? Then spark things up with a little baking soda and some vinegar and make a tiny, working rocket. Best of all—you probably already have most of the materials and ingredients lying around the house.
This is an awesome little science trick that has to be seen to be believed. Simply by emptying a bottle of "supercooled" water into a glass, you can watch it turn into ice right as your pour! It's no magic trick or chemical craziness—it's normal water and you can try it yourself right in your own home.
If you've never heard of geocaching, it's kind of a grown-up treasure hunt you play everywhere in the world. GPS coordinates are given as clues and the players must find the cache box. There is usually a log book to write your name and a small toy or present to collect.
I love robots. They have the potential to evolve into Asimovian destroyers of the human species, but have only just mastered the art of cleaning my rug. They have an ever increasing cool factor and a growing number of cheap and simple components that let the hobby roboticist reach for the burning miasmas of plasma. But to get to the stars, we need to start with the basics.
Sputnik was the very first man-made object to be sent into space. Though it was a truly epic accomplishment, all this Soviet sky surfer actually did was transmit a constant beeping noise back to the surface.
Omniscience is not required to make some really cool shit happen. Yes, it took a while, but we can make fuel from the Sun! Solar panels are basically our answer to God. And now that we can make solar electricity, finding the most efficient way to harvest it is tricky.
The guitar is a double-edged sword. I've played all my life, and though I love the act of guitar playing, there are quite a few people I could live with never hearing play again—ever.
What's the first thing you would do once you realized you were lost in, say, a desert? If you're like me, you would immediately pull out your cell phone and start dialing every number. But what if you have no service? What if your battery is dead?
If you're like me, you were disappointed when NASA cut their human space flight program. No longer could children and adults in dead-end jobs dream of someday walking on the surface of the Moon or drinking floating globules of water through a straw. Homo sapiens as a species are still making it up there, but I will never be one of the chosen ones.
Whenever we make a homemade circuit, we use what are called through-hole components. Any components with long metal leads is a through-hole component. They are great for soldering to, but it's tough to fit enough through-hole resistors and capacitors into a smartphone. To get those last microns, we have surface-mount components for SMDs (surface-mount devices). These are all of those teeny, tiny things you see when you crack open your digital camera or laptop case.