A bona fide pyrotechnics experts explains the chemistry that makes fireworks possible
‘Everything you see in a fireworks display is chemistry in action’
All across the country, Americans will wrap up their Fourth of July celebrations by watching the sky light up with fireworks. If you’re going to be one of them, you have chemistry to thank.
Fireworks displays have become increasingly sophisticated and spectacular, but the chemical reactions that make them possible are pretty basic, according toJohn Conkling, an adjunct chemistry professor at Washington College in Chestertown, Md., and past executive director of the American Pyrotechnics Assn. Conkling literally wrote the book on fireworks — it’s called “Chemistry of Pyrotechnics: Basic Principles and Theory,” and it was first published in 1985.
As Conkling explains in the video above, all fireworks have two essential ingredients — a chemical that’s rich in oxygen (different types of these chemicals produce different colors when they burn) and a chemical that serves as the fuel (different fuels burn at different rates and temperatures).
“Without chemistry, you wouldn’t have the burning mixtures, Conkling says. “Without the burning mixtures, you wouldn’t have fireworks.”
Once these mixtures are made, they are packed into an aerial shell that’s about as big as a snowcone. This cardboard contraption has a pocket of black powder on the bottom, which propels the shell skyward. Inside the pocket is a time fuse that connects to a black powder bursting charge.
When the time fuse burns away and the bursting charge explodes, it ignites an array of “effect pellets.” These pellets — ranging from the size of a pea to the size of a marble — produce the colors and visual effects that audiences crave.
The entire shell fits inside a cylindrical mortar tube that points the package up toward the sky.
In the video, Conkling (wearing safety glasses!) takes a blowtorch to small piles of powder. A pile containing strontium chloride burns red, a pile made with barium acetate burns green and a pile with copper oxide burns with a blue tint. When “moderately coarse magnesium” is added to the mixture, the combustion produces white sparks.
“Everything you see in a fireworks display is chemistry in action,” he says in the video, which was produced by the American Chemical Society.
In an interview with the PBS program “NOVA,” Conkling said researchers are working to create fireworks that burst in colors like lime green, violet and hot pink. They are also trying to develop shells that will burst in the shape of letters, paving the way for pyrotechnic words.
Conkling’s childhood fascination with fireworks has propelled him through a career that produced eight patents. His work spans both military and civilian uses, but in his view, fireworks are valuable even when they aren’t practical.
“Fireworks make people happy,” he says in the video. “There’s something about watching the night sky explode in color and sparks and noise that I think gets really deep in the human soul.”
Swiss photographer Fabian Oefner is known for using art to breathtakingly illustrate simple science at work. His latest series of images, called The Invisible Dimension, captures crystals of color rising in reaction to a speaker’s soundwaves, magnetic liquid pushing paint into canals, and a flame of burning whiskey traveling through a glass bottle. In a recent TED talk, the artist explains the motivation behind his creations: “I’m trying to use these phenomena, and show them in a poetic and unseen way, and therefore invite the viewer to pause for a moment and think about all the beauty that is constantly surrounding us.” You can see Oefner’s artistic process demonstrated in his TED talk below, and check out his website to see The Invisible Dimension photos in high resolution.
“In ancient times, Julius Caesar painted his fleet of reconnaissance boats entirely in a blue-green wax — including the sails, ropes and even the crew — making the vessels virtually invisible against the sea. In a sense, camouflage is the original invisibility cloak, one that animals have evolved to such stunning perfection that they can disappear before our very eyes. It’s a marvelous trick for survival.
But beyond hiding from the view of hungry predators or opposing soldiers, the idea of invisibility has long captured our imagination, notably the imagination of “Harry Potter” fans and random physics geniuses who strive to create real-life invisibility cloaks. One such brainiac, Baile Zhang, an assistant professor of physics at Nanyang Technological University in Singapore, showed off his “invisibility cloak” on Monday at the TED2013 talks in Long Beach, Calif.
Presenting as part of TED Fellows Day, a day when young researchers, artists, and other assorted brilliant minds are selected to give four-minute talks, Zhang awed the audience with his awesome cloak.
Zhang’s device is in its early stages; just a small gizmo in prototype phase — but it works. Speaking to Carla Sinclair of Boing Boing, Zhang explained that the cloak is made out of two pieces of natural calcite (optical crystals) that are joined together. The calcite bends light and suppresses shadows, tricking the eye into seeing nothing.
Sinclair writes of the demo, “The cloak’s ability to conceal an object so that both the cloak and the object become invisible was astonishing. Zhang placed the cloak over a bright pink Post-it note and voila! Nothing! The pink paper disappeared. And the cloak itself wasn’t really visible in the first place.”
As inventors generally have a purpose in mind for the innovations they conjure up, it’s logical to assume that Zhang’s extreme camouflage machine is being developed for the military or some other high-end application, but no. When asked what his plans were, he said that it had no purpose, he “just created it for fun.” Such are the hobbies of whiz-kid wizards.
AN : writers have written, concocted the thoughts and ability of invisibility from comic book characters to science fiction. It is not altogether beyong capability, as this TED Talk participant demonstrates. If one thinks about it, the visible spectrum of light is what we operate in….yet the electromagnetic spectrum is much broader than just our visible light receptor spectrum . Think , for example, infrared spectrum. We cannot see that spectrum but with instrumentation, we can “see” in the IR range. It should not surprise that we then can de-visualize. The applications of this are intriguing.
World’s largest natural sound archive now fully digital and fully online.
“In terms of speed and the breadth of material now accessible to anyone in the world, this is really revolutionary,” says audio curator Greg Budney, describing a major milestone just achieved by the Macaulay Library archive at the Cornell Lab of Ornithology. All archived analog recordings in the collection, going back to 1929, have now been digitized and can be heard at http://www.MacaulayLibrary.org
“Erez Lieberman Aiden is a talkative witty fellow, who will bend your ear on any number of intellectual topics. Just don’t ask him what he does. “This is actually the most difficult question that I run into on a regular basis,” he says. “I really don’t have anything for that.”
It is easy to understand why. Aiden is a scientist, yes, but while most of his peers stay within a specific field – say, neuroscience or genetics – Aiden crosses them with almost casual abandon. His research has taken him across molecular biology, linguistics, physics, engineering and mathematics. He was the man behind last year’s “culturomics” study, where he looked at the evolution of human culture through the lens of four per cent of all the books ever published. Before that, he solved the three-dimensional structure of the human genome, studied the mathematics of verbs, and invented an insole called the iShoe that can diagnose balance problems in elderly people. “I guess I just view myself as a scientist,” he says.”
AN: although the profile of Erez is from last year, nonetheless, it is still highly inspiring. All of us can expand our own particular fields of interest by taking a multi / cross/ inter- diciplinary approach to our questionings. The TED talk with Erez and his colleague ,Jean-Baptiste Michel , in 2011 is insightful and delightful !
