About 230 years ago, molten lead that rained from the sky—historically something to avoid at all costs—became a clever new way to manufacture an important commodity: shotgun ammo.

Precisely round pellets fly straighter, but casting each in its own 1/8-inch mold isn’t exactly mass production. In space, making them would be easy. In zero gravity, surface tension pulls any liquid into a sphere, the shape with the least surface area for a given volume.

Martin Montesano had been captivated since childhood by enormous walking machines like the ones in The Empire Strikes Back. A few real-life versions have been built before, but they never lived up to his vision. He wanted his to be huge.

If you're going to be in New York City next Tuesday, there are still a few tickets left to the Kitchen Alchemy duo's class, "Chilling Out With Liquid Nitrogen."

Did PopSci's recent article on cooking with liquid nitrogen pique your interest? Learn first-hand from H. Alexander Talbot and Aki Kamozawa how to flash-freeze foods and shatter them; turn any cream into ice cream; grind olives into powder; and other kitchen-tech wonders.

The class is at Manhattan's Astor Center, August 26 at 6:30 pm. Use the secret discount code POPSCI when ordering your ticket and get 10 percent off.

Hope to see you there!

If you've ever bent the pin on a microcontroller while trying to insert it into a DIP programming socket, you're not alone. Aligning those crazy pins again and again, while intermittently prying them out of the programming socket and then inserting your freshly burned chip into a target circuit, can lead to a long and sleepless night. Luckily, there is a cure for the bent pin nightmare. And this prescription costs less than $35.

The next time you catch crap from your tool buddies for carrying such a gadget-geeky cell, tell them to kiss your iPhone-carrying ass. Then point them here to see how handy Apple’s finest can be in the hands of a Toolmonger. I’ve found dozens of shop-friendly uses for my phone. Launch the gallery here to see five.

There’s an inherent dilemma in purchasing a flashlight: The really bright and long-lasting LED models are pretty expensive, and the heavy, cheap traditional ones always seem to be dead just when you need them the most. Good thing it’s possible to build your own superbright, reliable and inexpensive hybrid light.

If you've ever wanted to learn how to hack a circuit's firmware, a great beginning point would be SparkFun Electronics. Many of the development, prototyping, and sensor products sold by SparkFun come equipped with a special programming interface. Even better, most of these products feature downloadable firmware. Therefore, with just a modest amount of effort, you can modify one of these products' firmware, reprogram the circuit, and create your own customized product.

In kitchens all around the world, cooks are experimenting with liquid nitrogen. It is a dramatic and very useful culinary tool that can cool or freeze things in an instant. It is made of pure nitrogen in a liquid state. Daniel Rutherford discovered the element nitrogen in 1772. It makes up 78.1% of the earth's atmosphere by volume. In its gaseous state, nitrogen is odorless, colorless, non-flammable, non-toxic, and largely inert. Nitrogen is found in organic materials, foods, explosives, fertilizers, and poisons.

Ah, that sinking feeling: You’ve just left for a business trip when you realize you’ve forgotten the PowerPoint presentation on your PC at home. No matter: With the right tools in hand, you’ll be able to retrieve your file regardless of where you are.

I think that everyone in New York City read last week's article by David Leite on the Quest for the Perfect Chocolate Chip Cookie. One of the main tricks from the article is to rest your dough for 36 hours before baking the cookies in order to improve the flavor. In my work as a chef I have often made cookie dough in advance and baked to order. I knew that refrigeration had beneficial effects although I had never tested the theory to the extent that David Leite did for the article.