Even with the huge number of mobile apps already available, cellphone screens are always awaiting new ideas from innovative developers. If you have your own idea for the perfect app, whether for a wide audience or just your own use, you're in luck—you no longer need to be a deft programmer to produce it. There are now a number of app-generating tools on the Web that will enable you to bring your concept to life by clicking instead of coding.
A fine-mesh kitchen sieve with a candle inside simulates a Davy miner's safety lamp. An explosive mixture of propane gas and air is blown in from the outside. If the mesh is fine enough, the fire will stop at the screen even as the explosive gas flows through it.
If you were a coal miner in the early 1800s, the light you used was an open-flame oil lamp—even though mines were sometimes filled with "fire-damp," a volatile mixture of air and methane gas. Explosions were inevitable, and at times threw bodies from mine shafts like grapeshot from a cannon. Humphry Davy became a national hero when, in 1815, he found a remedy: Surround the lamp flame with mosquito screen.
By Darren MurphPosted 01.14.2010 at 2:48 pm 7 Comments
Feel chained to your tunes? There are a number of ways to get your home music library from your computer to other rooms. You could go the DIY route and set up another computer on your wireless network to share songs. But for a simpler setup, go with a dedicated media-streaming device.
The project began as a challenge. Carl Morgan’s son Justin, recalling how he used to have to crank up a nasty hill outside their Bainbridge Island, Washington, home every day, asked his dad, a retired electrical engineer, if he could build something that would take care of the pedaling for a lazy biker. The “yes” arrived about a year later—an electric-motor-powered tandem bicycle featuring a gleaming robot named Joules.
Save money—while still taking great pictures—by using a vintage lens with your digital camera
By Russ JuskalianPosted 12.21.2009 at 10:55 am 8 Comments
One of the key features of digital SLR cameras is the ability to change lenses to get a wide range of shots, from ultra-zooms to super-close-ups. And now DSLR owners no longer need to spend a bundle on high-end lenses to take advantage of their camera's functionality—there's a way to use older, far less expensive manual-focus lenses instead. All that's required is a twist-on adapter ring, which you can find online for between $5 and $50.
There’s nothing better than Guys’ Night, an evening of gaming or movies in my basement media room. The only trouble is when we (invariably) order pizza, because I can’t hear the doorbell from there. The solution: an inexpensive DIY digital surveillance system tied to Twitter.
By Dave ProchnowPosted 12.01.2009 at 4:45 pm 6 Comments
Throw out your old wall clock. You’ll be bored with it the moment you’re finished assembling your own persistence-of-vision (POV) clock. Projects based on POV—the phenomenon by which your eye very briefly continues to see an image after it has disappeared—use a moving display to show what looks like a static image. But instead of featuring only a single fixed message, this model shows you the current time on a continuously updated rotating display.
In 1989, François Knorreck took a long ride in the sidecar of a friend’s motorcycle and enjoyed it so much that he decided to build a rig of his own. Now, 20 years, 63 bodywork molds and innumerable headaches later, he has it: a handcrafted masterpiece that’s part motorcycle, part Lamborghini.
The explosive C4, a favorite for everything from demolition to terrorism to action movies, is in fact one of the safest explosives. How can an explosive be safe? If it's hard to set off by accident. C4 is so stable that you can light it with a match (it burns but does not explode) or shoot it (it splatters but does not explode). To go bang, it requires a detonator that produces both heat and shock.
At the other end of the spectrum are mixtures that ignite simply from being scratched or knocked. There are obvious challenges in mixing, storing, and handling these substances so that they explode only when intended, yet they're surprisingly common.