Writing secret notes with lemon juice was one of my favorite pastimes as a child. All it took was a small flame to lightly scorch the paper and reveal the hidden message. Now that I'm tall and pay bills, lemon ink just isn't exciting enough anymore. Luckily, we can use another kind of invisible ink to write in fire! By using the saltpeter, we can whip up invisible fire ink in no time.
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.
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.
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.
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!
Spring has sprung, which means it's time to plant all those delicious vegetables and lucrative cash crops. If you are like me, every year you meticulously plan every aspect of your garden before dutifully neglecting it all summer. I decided enough was enough and built this simple automatic watering system.
The DIY industry is booming, despite the desperate blackmailing of society by finance capitalists. Companies like Adafruit and Makerbot are grossing well over a million dollars a year, and Evil Mad Science Laboratories just recently dedicated themselves to running a full-time kit business. Making kits is fun, but starting a business can be scary. If you already enjoy making gadgets and want to take the plunge into selling your own kits online, this article is for you.
Everyone dreams of having super powers. Flying, invisibility, and x-ray vision are popular, but my favorite is fire power! I've always wanted to be Wheeler from the Captain Planet kids show, and now I can with these handheld fireballs of awesomeness. The fireballs burn at a low temperature, so they are safe to hold in your hand and throw (shoot) at imaginary enemies.
Making your own circuit boards can be a daunting challenge. You have to design a schematic, test it on a breadboard, design the board layout, and then after all of that, you still have to print and etch a board!
Computer viruses are terrifying. They are undetectable, dangerous, and operate constantly right under your nose. For the average computer user, there are only a few repair options. You could buy expensive antivirus software that causes more problems than it fixes, you can wipe your hard drive clean and lose all of your important data, or if all else fails—just switch to Linux.
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.
Here are three awesome videos on whipping up lab quality instruments in your garage! Science is accessible!
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.
Fans of Doctor Who know that the sonic screwdriver is the ultimate tool. It can unlock doors, turn on lights, detect life forms, solder wires, and sabotage weapons.
Want to build your own life-sized, working replica of WALL-E? Be prepared to take on a second job! Mike Senna spent two years perfecting his own version, working 25 hours a week and totaling somewhere around 3,800 hours for the whole project. He had no blueprints to go by, so he spent a lot of time watching the movie over and over to get everything just right. The video below shows some of the construction; skip to about the one minute mark to see WALL-E in action.
Your favorite device is running low on juice and needs a couple new AA batteries—and with a quickness. You run to the store and grab the first pack of AAs you see. But should you? There's tons of options available, so which make and model gives you the most power per dollar?
There's no denying the coolness of an iPhone. But what if you pulled a homemade wooden cell phone out of your pocket instead? You'd probably be the talk of the town. If you like that idea, then make it a reality by building your own cell phone!
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?
There is nothing more annoying than a greedy roommate. It's absolutely infuriating to wake up and find the cookies your mother just made for you gone without a trace. Your favorite drink is empty and the homemade meal you worked so hard on the night before is nowhere to be found. This irked me so much that I made this shocking cookie jar. When a cookie burglar touches the side and the lid of the jar simultaneously, a small electric shock stops them in their tracks.
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.
Glass is one of the least reactive substances known to chemistry. It is the standard container material for almost all lab chemicals because it's so inert. But there are a couple of substances that have strong reactions with glass. Sodium hydroxide, aka solid drain cleaner or lye, can easily be stored in glass as a solid, but when molten, it reacts violently with glass and can actually dissolve it away! So, the next time you clog up your drains with broken glass beakers and flasks, rest assur...
How To: Make a Mini Flamethrower, Exploding Fireball, & Flint Bomb Sparkler with Disposable Lighters
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!
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.
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. Because putting dry ice in a sealed bottle would effectively turn it into a bomb, you'll need to make a safety valve for the bottle.
Ever wonder how all of those tiny chips and components can fit inside your laptop or smartphone? If you tried to squeeze them in there yourself, your laptop would quickly become too heavy for your lap, and your mobile phone would need wheels to stay mobile.
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.
The only thing better than successfully pulling off a new experiment is doing it with household materials. You get to laugh in conceit as professional scientists everywhere spend all their grant money on the same project you just accomplished with some under-the-sink chemicals! However, there are times when DIY gets dangerous. Some household chemicals are not pure enough to use and some are just pure dangerous. Let's take a look at two problems I have encountered in the course of mad sciencing.
Even if you live in a big city, chances are you have some wild raccoons or foxes that cannot abide a vertical trash barrel. While apparently omnipresent, these phantasmic critters usually vanish in the night leaving only a shameless trail of refuse you never wanted to see ever again. While I haven't found a way to stop them, I can help you snap some photos of the dastardly creatures.
You're never too young to start building your vast swarm of robotic minions. Taking over the world requires a whole lot of robots. The sheer volume of robots needed means your first wave will have to be made of cheap materials. After they take over key resources, you can upgrade to Kevlar and titanium. But to start, let's make popsicle stick insect robots!
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.
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.
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. The only problem was th...
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. What You'll Need
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. The most important thing you need is the sensor tag, so that you can record the am...
Helping to prove that science is way awesome, an 18-year old electrical engineering student has successfully made a light bulb float. His name is Chris Rieger, and he's been working on his "LevLight" project for about six months now, with pretty amazing results. This feat of ingenuity was accomplished by using magnetic levitation, although that over-simplification masks how considerably difficult this undertaking was.
Dreams are like an internal human holodeck. Inside your mind, anything is possible, from your grandest wishes to your worst nightmares. This is all well and good, but what if you could control your dreams and become the omniscient god of a handpicked reality whenever you go to sleep? Inception took this idea to the logical extreme by invading other people's dreams.
Maybe not water per-se, but with this simple technique you can turn one of the most abundant materials on earth into a highly explosive gas.
Why can't Thanksgiving be a celebration of fireworks, too? This year, it can be with an innocent looking pumpkin pie that erupts an insane fountain of flames and fire! In fact, the pie filling is actually a flammable mixture of sugar and potassium nitrate, which was made using the same process as my DIY smoke flares with fuses.
Homemade circuits are amazing. You can build any kind of circuit on a simple perfboard, as we have seen in previous projects. However, some projects require very tiny circuit boards. We could special order some boards from a printed circuit board (PCB) factory, but that will most likely involve a high price per board and a few thousand miles of delivery service to pay for.
How To: Send Your Secret Spy Messages Wirelessly Through Light with This DIY Laser Audio Transmitter
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. A laser audio transmitter uses light rather than radio waves to transmit sound. This is a much more secure way to send audio communications because the laser is a focused beam of light, whereas radio waves are not controlled, so they can be pic...