“A brilliant fireworks display is a complicated, calculated mixture of chemistry, ballistics and imagination. Here is an in-depth look at how the pros pull it off every year:
“There’s no tradition quite like a Fourth of July fireworks display. Lawnchairs and blankets line the grassy viewing area as spectators wait for spellbinding colors, thrilling explosions and intriguing shapes to paint the sky. The event may be magical—especially for the kids—but of course, its all the product of meticulous chemistry and clever ballistics.
— By Amanda Dematto, Popular Mechanics —
“Behind the curtains—out on a river barge floating a distance from the onlookers’ vantage point—are brown cylindrical and spherical canisters of varying sizes, placed in mortar tubes and wired to a central control. An engineer pushes a button that routes an electrical impulse through 40 feet of wiring to the first canister. The impulse lights a fuse at the canister’s base, which burns through to a black powder that catapults the shell into the sky. At the same moment, a time-delay fuse is triggered, giving the shell time to soar before bursting. After about 5 seconds the shell peaks, the fuse kindles a bursting charge, and poof!—the casing ruptures, and magnificent tendrils of red, white and blue stream into the sky.
“Every step of this process is a complex, carefully crafted process. If one thing is off—too much black powder, misaligned stars or a misplaced trigger—everything can fail. Here’s a look at how professionals pull it off every year while one-upping last year’s pyrotechnic display. . . .” (continue reading)
Photograph courtesy Jane Wiggins
I’d have thought that whatever different types clouds exist here on earth, we’ve already seen and categorized them all. Looks like I was wrong. National Geographic says,
“These choppy clouds over Cedar Rapids, Iowa, in an undated picture could be examples of the first new type of cloud to be recognized since 1951. Or so hopes Gavin Pretor-Pinney, founder of the Cloud Appreciation Society.“The British cloud enthusiast said he began getting photos of ‘dramatic’ and ‘weird’ clouds (including the above) in 2005 that he didn’t know how to define.“A few months ago he began preparing to propose the odd formations as a new cloud variety to the UN’s World Meteorological Organization, which classifies cloud types. . . .” (continue reading)