This week, we’re celebrating the American in Scientific American with a few cool stories about freedom (or lack thereof), independence and fireworks. Ever wonder how they make so many different color fireworks? The secret ingredient is burning metal. That’s right, we celebrate our freedom by shooting chunks of metal into the air and lighting them on fire. Now you can make your own colorful conflagration here on the ground in this (adult supervision very required) hands-on science experiment. Sparklers are great, but it’s hard for us to hold more than two at a time. Soon you could have help from scientists at the Center for Robotics Research at Kings College London, where they are hard at work on a robotic octopus. The researchers are drawing inspiration from the way octopi coordinate their many soft, flexible limbs to build a many-armed machine to help out in difficult surgery. But we all know a robotic octopus with eight sparklers would be pretty sweet. Fireworks aren’t the only way to light up this holiday weekend. A Dutch company is rolling out the world’s first electronic marijuana cigarette, putting it at the cutting edge of technology and the law. The new device is, in the company’s words, “100 percent legal,” since the device itself is completely cannabis free. The device, however, is easy to load with liquid cartridges filled with whatever substance its owner desires. Oregano perhaps? Friday is supposed to be a celebration of liberty, but do we even have free will at all? Philosophers have debated the existence of free will for centuries, and more recently neuroscientists have entered the fray with disturbing evidence that our brains make us act before we’re even aware of what we’re doing. Another brain-related story. Turns out running might help cure blindness, at least in mice. Lazy eyes, which happen when the visual processing circuitry in the brain fails to develop, were essentially cured in mice that ran on treadmills four hours per day for three weeks. (Four hours? Yikes!) Scientists think it’s because running forces the brain into visual overdrive—when you’re going fast you need to really watch what’s around you. Maybe it’s time to update the old nursery rhyme: Three blind mice. See how they run. See how they see? Happy Fourth of July from Scientific American!
