Hot Mad Science Posts

How To: Make Solid Rocket Fuel at Home with Old Newspapers

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.

How To: Make a Simple Fog Machine to Prank Your Roommates

Like theme music, I always feel that I need more fog in my life. Fog can be useful for many reasons—warding off smaller siblings from your bedroom, keeping curious hands out of your cupboard, and tricking your friends into thinking there's something horribly wrong with their vehicle. So, today we'll be making a very simple fog machine for small scale applications.

How To: Build a Long Range Laser Spy System for Eavesdropping on Your Neighbors

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. LucidScience built the Laser Spy System for about $20. To make your own, you'll need a cheap laser pointer, an NPN phototransistor, a headphone amp, and a few other small pieces listed below. A light-to-sound circuit is installed in a small plastic box with the...

How To: Make Slow Burning Fuses from Yarn, Sugar, & Potassium Nitrate

Here's how to make a simple form of a slow burning fuse from materials around the house. WARNING: Ignition of an incendiary or explosive material may not be legal in your area, so check local laws before attempting. Use of this video content is at your own risk.

How To: Turn a Microwave Oven Transformer into a High Amperage Metal Melter!

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. If you liked the Metal Melter you saw in my previous project, here's how you can make your own!

How To: Make a Hydrogen Fireball from Aluminum Foil and Toilet Bowl Cleaner

Balloons are fun, but the helium ones are always more entertaining. So today, we're going to learn how to make hydrogen gas by combining toilet bowl cleaner with aluminum foil. With hydrogen, you get the same lighter-than-air properties of helium, plus it will explode! Historically, this has proven disastrous, but for our tiny-scale experiments, it will be safe and fun!

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!

DIY Lab Equipment: Build Your Own Reflow Oven Out of a Toaster for Precision Temperature Soldering

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.

How To: DIY Rocket Propellant! How to Cook Solid Rocket Fuels Using Common Household Ingredients

Cooking isn't something that interests me much, unless it results in a fast burning fuel and a successful rocket launch!

How To: Light Up the Night Sky with Your Own Burning 'Cincinnati Fire Kite' That Flies by Itself

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.

Science Gives You Super Powers: How to Shoot Fireballs from Your Hands

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.

Spice Rack Explosives: How to Make Gunpowder with Salt & Sugar

The best chemistry experiments are those you can perform with items already laying around your house. With only some sugar, salt substitute and an instant cold pack, you can make your very own gunpowder! Being able to make homemade gunpowder without a trip to the store can be a lifesaver, no matter if it's just for testing out a Civil War-era musket, blowing up stubborn tree stumps, or preparing for battle when imperialists overrun your country.

How To: Build Your Own Mini Altoids Guitar Amp for About $5

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.

How To: DIY Solar-Powered, RC Lawn Mower: Cut Your Grass Without Ever Leaving the Couch!

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.

Elementary Sputnik Satellites: How to Make Trash Bag Hot Air Balloons

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.

DIY Polygraph Machine: Detect Lies with Tin Foil, Wire and Arduino

Lying is awesome. From a very young age, children learn that flat out denying the truth gets you out of trouble and helps keep you calm in the face of horror. But what happens when you just have to know if someone, say, used your toothbrush? You could ask them to take an expensive and arduous polygraph test.

How To: Create Your Own Cast and Oogoo to Give Your DIY Gadgets the Shape You Want

I think it's fair to say that every maker yearns for a 3D printer. You can replace circuit board connectors, fix your glasses, create ski grips, and make whole machines out of printed plastic parts—even a 3D printer. But without a 3D printer on hand, you can always resort to Sugru.

How To: 10 Things to Do at a Birthday Party with Liquid Nitrogen

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!

How To: Make Homemade Smoke Flares with Fuses

Here's a technique I used to whip up a batch of super cheap and easy to make smoke flares! WARNING: Ignition of an incendiary or explosive material may not be legal in your area, so check local laws before attempting. Use of this video content is at your own risk.

Glass Cutters Are for Tools: How to Dissolve Glass Using Sodium Hydroxide

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...

Inception in Real Life: Make These Lucid Dreaming Glasses and Take Control of Your Dreams

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.

How To: Make Your Own "TV-B-Gone" to Silence All Televisions That Oppose You

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.

Bat Science: How Realistic Are Batman's Gadgets in Dark Knight Rises?

One of the best things about Christopher Nolan's Batman trilogy is how realistic he makes the caped crusader feel. Unlike the Joel Schumacher or even the Tim Burton versions, Nolan's world seems grounded in some level of scientific fact. But just how close is science to actually being able to replicate some of the Dark Knight's gadgetry?

How To: Make a Lethal Traveling Arc of Electricity with a MOT-Powered Jacob's Ladder

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.

DIY Blacksmithing: Forge Your Own Steel at Home!

Metal is a great material to work with. It's rigid, tough, malleable and conductive, but sometimes the part we need doesn't exist in any store. In order to create custom pieces, you need to either melt the metal and cast it in a mold, or heat it until it's soft enough to shape with your hammer. Properly melting metals can be a bit dangerous in our home shop, but we can make a coffee can forge for all of our home blacksmithing needs.

News: Scientists Create World's Smallest Snowman—He's Just 0.00012 Inches Tall

Frosty the Snowman is a fairy tale they say, but this microscopic snowman is very real and just broke the record for the world's smallest snowman. (Though, it's not Guinness-official yet.)

How To: Turn Water into Fuel by Building This DIY Oxyhydrogen Generator

Here's how to build a sexy looking water-fuel generator that will convert your tap water into an extremely powerful, clean burning gas!

The Art of 3D Printing: Turning Cool Ideas into Physical Three-Dimensional Models

Three-dimensional printing is one of the many wonders of modern technology. It's the first step towards real life Star Trek replicators and Timeline-esque teleportation chambers. While we aren't at the level of reconstructing strands of DNA, it's already possible to make tons of fun and useful designs on a 3D printer.

Dragon Safari: The Incredible Metamorphosis from Nymph to Dragonfly

Last time we took a look at some of the creatures of the pond, including the dragonfly nymph. Today, we examine the all-grown-up dragonflies in the field you are used to seeing on summer days! Dragonflies are not dangerous, but the extra large ones can bite you something fierce if you handle them wrong.

10th Time's the Charm: Success and Failures of Making a Jam Jar Jet Engine

I finally got around to trying out this jam jar jet project. The most successful and longest lasting pulse was somehow the only one I did not record. You can imagine how frustrating that probably was, though my tenth and final attempt was nearly as satisfying. But even the failures were fun to watch, especially the blue flame floating, almost dancing, around the jar. I especially liked the small foghorn sound that my first failed attempt produced.

How To: Shoot Fire from a Water Bottle Using Rubbing Alcohol and a Match

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.

How To: Build a Vacation Pet Feeder with a DIY Linear Actuator

If you are a pet owner, going on vacation can be stressful. Usually, you need a friend or neighbor to come over everyday and feed your pets. However, by enslaving robots you can keep your pet happy and enjoy a stress-free holiday.

News: DIY Arduino Battery Tester Reveals the Secret Capacity of Disposable Batteries

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?

How To: Weapons for the Urban Guerrilla: Make a Taser from a Disposable Camera

The agents of empire do not always arrive with warning. When you are besieged, surrounded, and infiltrated, imagination is often your best weapon against the oppressors. If all you have at hand is some duct tape and a disposable camera, fear not, you have the makings of a powerful taser!

Fire Texting: How to Write Secret Messages with Fire

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.

How To: Make "Fight Club" Soap Out of Bacon & Drain Cleaner

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!

How To: Make Dry Ice at Home Using a CO2 Fire Extinguisher

Here's how to make dry-ice at home, or wherever you feel like it! All you need is a pillow case, and a CO2 fire extinguisher.

How To: Make a Fake, Pirate-Worthy Gold Bar on the Cheap

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.

How To: Melt Metal with a Modified Microwave Oven Transformer

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!

How To: See-Through DIY Rocket Engine Lets You Watch Fuel Combustion in Action

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.