Applied Physics

In a previous article I demonstrated how to use a One Time Pad cipher using a pen, paper, and Scrabble tiles (or Boggle cubes). If used correctly, One Time Pads cannot be broken by the NSA or any intelligence service on Earth because the One Time Pad keys use a randomly generated set of letters or numbers to encrypt your message. The only person or persons who have your key can decrypt your message. Once the message has been encrypted by you and decrypted by your recipients, the One Time Pad keys are discarded (shredded, burned, what have you) and never used again. This manual One Time…

Why did the supersonic trans-Atlantic Concorde aircraft end up being a huge flop? It is commonly believed that European subsidies don't make for efficient airlines and the cost made it impossible to keep the aircraft maintained - but a new paper by a mechanical engineer says it was...evolution.  Adrian Bejan, professor at Duke University, says that a physics paper he penned more than two decades ago helps explain the change in passenger airplanes from the small, propeller-driven DC-3s of yore to today's behemoth Boeing 787s.  The Concorde, alas, was too far from the curve of these…

Birdsnap is an iPhone and web based app that uses many of the techniques of facial recognition software to identify 500 of the most common North American birds. The web based version of Birdsnap is actually very easy to use: upload your picture, click on the bird’s eye, click on the bird’s tail, enter your location along with the date the picture was taken, and click submit. I’ll demonstrate how to use Birdsnap even though it was unable to identify the bird I submitted. Last Wednesday I played golf at South Grove Golf course and my cousin snapped the following picture near the 9th hole tee…

When you see an article about geckos and their ability to sit upside down, Spider-Man references are sure to follow. And if the topic is that sticky ability in spiders, you will get Spider-Man references and a picture. Yet even geckos have limits - that's just plain nanophysics. The fact is, sooner or later the grip is lost, no matter how little force is acting on it. But knowing the limits can have considerable benefits, for instance in the production of graphene - because graphene consists only of one layer of atom, and which must be easily detached from the substrate. Obligatory Spider-Man…

We know that ancient Japanese gold leaf artists were truly masters of their craft - their works are ornate and delicate. What remains a mystery is how artifacts were gilded with gold leaf that was hand-beaten to the nanometer scale. Gold leaf refers to a very thin sheet made from a combination of gold and other metals. It has almost no weight and can only be handled by specially designed tools. Even though the ancient Egyptians were probably the first to gild artwork with it, the Japanese have long been credited as being able to produce the thinnest gold leaf in the world. In Japanese…

Stanford researchers envision a crystal that can form a monolayer three atoms thick. Their computer simulations show that this crystal, molybdenum ditelluride, can act like a switch: its crystal lattice can be mechanically pulled and pushed, back and forth, between two different atomic structures -- one that conducts electricity well, the other that does not.  The switchable material is formed when one atomic layer of molybdenum atoms gets sandwiched between two atomic layers of tellurium atoms. Molybdenum and tellurium are elements that are currently used as additives for making alloys…

When it comes to urine, it's all relative. We can't prove Sir Isaac Newton was thinking about how animals urinate when he was developing his laws of gravity but he can't prove he wasn't either. What we can prove is that they are connected – by the urethra, to be specific. A new study investigated how quickly 32 animals urinate. It turns out that it's all about the same. Even though an elephant's bladder is 3,600 times larger than a cat's (18 liters vs. 5 milliliters), both animals relieve themselves in about 20 seconds. In fact, all animals that weigh more than 3 kilograms (6.6 pounds)…

In previous articles I’ve demonstrated how to use littleBits and erector set parts to build a magnetic stirrer and a sample rotator. Since I was able to drive Erector set machines with the littleBits motor I decided to try to use it to drive K’nex contraptions. In this first attempt, I was able to design a hybrid of Erector set parts and K’nex parts to build a K’nex kinetic interactive sculpture I call “Mutually Assured Destruction.” I was unable to come up with a simple way to attach the littleBits motor directly to K’nex parts without using, say, a hot glue gun, so I decided to use…

Wrinkles, creases and folds are everywhere in nature, from our skin to the buckled crust of the Earth. They're useful structures for engineers. Wrinkles in thin films, for example, can help make durable circuit boards for flexible electronics. A new mathematical model developed by researchers from Brown University could help engineers control the formation of wrinkle, crease, and fold structures in a wide variety of materials. It may also help scientists understand how these structures form in nature.  "In nature, solid materials often have stiffer surfaces and a more compliant substrate…

Have you ever wondered how hand warmers and cold packs worked? The kind that can be stored at room temperature and then used when needed depend on exothermic and endothermic chemical reactions. An exothermic chemical reaction gives off heat into its surroundings. Conversely, an endothermic reaction absorbs heat from the surrounding environment. Source Hand warmers are exothermic—that is, they give off heat. Simply tear open the outer pouch, remove the inner pouch exposing it to air and shake up the contents. After a few moments the exothermic reaction begins and you can stuff it into…