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How Do Fireworks Actually Work?

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by Sarah Dobbs

Each year, as the Fourth of July approaches, the sound of explosions starts to become a normal part of the evening. Fireworks have existed in one form or another for around 1000 years, and they show no signs of going away anytime soon. But how do they work? Most of us just know to light the fuse and stand back. Let’s take a closer look …

ROCKETS

fireworks over new york city
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Rocket-type fireworks can produce all kinds of different effects when they go off, but the basic structure of an aerial firework stays more or less the same. Each rocket is made up of the following parts: a mortar, fuses, propellant powder, a shell, a bursting charge, and a collection of "stars." The mortar is the outer container, and the fuse is, of course, the piece that you light. When the fuse burns down, the propellant ignites and shoots the firework into the air.

When it’s airborne, a second explosion is triggered inside the shell by a time delay fuse. The bursting charges set off the stars—small, explosive pellets made of fuel and metallic compounds that create the lights in the fireworks display. Different metals create different colors when they ignite: barium goes green, calcium salts go orange, magnesium goes white, copper is blue, lithium turns red, and sodium becomes gold. And the arrangement of the stars will determine the shape of the explosion—so if they’re packed in a heart shape, they should reproduce that heart shape in the sky.

Other effects can also be built in by adding various ingredients; different kinds of fuel can create sound effects, for example, like the whistling or screaming noises some rockets make as they shoot into the sky. Stars can be made up of layers of different metallic compounds, to create multicolored explosions. And in some more complex fireworks, there may be several stages of explosions; in that case, there are generally multiple fuses inside the shell, and as each burns down, a different explosive goes off.

FOUNTAINS

fountain type fireworks
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Of course, not all fireworks are of the shoot-into-the-air-and-go-bang variety. Fountains don’t take off, and generally don’t go bang, either; instead, they stay where they’re placed and give off a cascade of sparks—like a fountain, but with pyrotechnics instead of water.

Usually conical in shape, fountains consist of a paper or plastic tube, with clay plugs at either end. Inside the tube are a couple of different kinds of fuel, plus the metal compounds that create the sparks. When the fuse is lit, the fuel ignites, and sparks are forced out of an aperture in the top of the fountain.

Again, different metals create different colors and effects. Multi-stage effects can be created by bundling multiple tubes together, so that as one finishes another starts, adding different colors or sound effects to the display.

CATHERINE WHEELS

wheel firework
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Catherine wheels are another common type of firework, and again the same kinds of ingredients are used to create a slightly different effect. Named for the unfortunate Saint Catherine, these fireworks are generally fixed to a pole or a mount, so that they can spin as they burn, creating a spiral of sparks.

Bigger Catherine wheels tend to have a plastic disk at their center, with “gerbs” attached around the edge. The gerbs are similar to fountains, in that they’re tubes filled with the mixture of ingredients that create the effects; when lit, the thrust from the explosives makes the wheel turn as they burn. And again, the effect can be made more elaborate with multi-stage effects and different colors; each gerb might be different, so that the wheel changes as each one ignites in turn.

Smaller Catherine wheels might, instead, be made up of a single long, thin tube coiled into shape around a smaller central disk. Again, the thrust of ignition makes the wheel spin.

SPARKLERS

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The only firework you should ever hold in your hand once it’s lit is a sparkler—a Fourth of July staple. Unlike most other fireworks, they don’t explode with a bang, but gently fizzle for around a minute, as a ball of sparks makes its way down a metal wire. And they’re pretty simple: basically, the metal wire is dipped into a pyrotechnic compound that’s made up of a metallic fuel, an oxidizer, and a binding material.

The metallic fuel is what creates the sparks; it’s usually aluminum or magnesium, which creates white sparks, but some sparklers may use iron or ferrotitanium for gold sparks instead. The oxidizer, which provides the oxygen to keep the spark going, is generally potassium nitrate. And then a binding material, a kind of flammable starch, keeps the mixture together, and burns away once the sparkler is lit.

Hopefully, none of that has taken away any of the magic of a good fireworks display. If nothing else, you’ll be able to impress your friends by quietly musing “oooh, barium” next time you see a green firework.

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Big Questions
Who Was Chuck Taylor?
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From Betty Crocker to Tommy Bahama, plenty of popular labels are "named" after fake people. But one product with a bona fide backstory to its moniker is Converse's Chuck Taylor All-Star sneakers. The durable gym shoes are beloved by everyone from jocks to hipsters. But who's the man behind the cursive signature on the trademark circular ankle patch?

As journalist Abraham Aamidor recounted in his 2006 book Chuck Taylor, All Star: The True Story of the Man behind the Most Famous Athletic Shoe in History, Chuck Taylor was a former pro basketball player-turned-Converse salesman whose personal brand and tireless salesmanship were instrumental to the shoes' success.

Charles Hollis Taylor was born on July 24, 1901, and raised in southern Indiana. Basketball—the brand-new sport invented by James Naismith in 1891—was beginning to take the Hoosier State by storm. Taylor joined his high school team, the Columbus High School Bull Dogs, and was named captain.

After graduation, instead of heading off to college, Taylor launched his semi-pro career playing basketball with the Columbus Commercials. He’d go on to play for a handful of other teams across the Midwest, including the the Akron Firestone Non-Skids in Ohio, before finally moving to Chicago in 1922 to work as a sales representative for the Converse Rubber Shoe Co. (The company's name was eventually shortened to Converse, Inc.)

Founded in Malden, Massachusetts, in 1908 as a rubber shoe manufacturer, Converse first began producing canvas shoes in 1915, since there wasn't a year-round market for galoshes. They introduced their All-Star canvas sports shoes two years later, in 1917. It’s unclear whether Chuck was initially recruited to also play ball for Converse (by 1926, the brand was sponsoring a traveling team) or if he was simply employed to work in sales. However, we do know that he quickly proved himself to be indispensable to the company.

Taylor listened carefully to customer feedback, and passed on suggestions for shoe improvements—including more padding under the ball of the foot, a different rubber compound in the sole to avoid scuffs, and a patch to protect the ankle—to his regional office. He also relied on his basketball skills to impress prospective clients, hosting free Chuck Taylor basketball clinics around the country to teach high school and college players his signature moves on the court.

In addition to his myriad other job duties, Taylor played for and managed the All-Stars, a traveling team sponsored by Converse to promote their new All Star shoes, and launched and helped publish the Converse Basketball Yearbook, which covered the game of basketball on an annual basis.

After leaving the All-Stars, Taylor continued to publicize his shoe—and own personal brand—by hobnobbing with customers at small-town sporting goods stores and making “special appearances” at local basketball games. There, he’d be included in the starting lineup of a local team during a pivotal game.

Taylor’s star grew so bright that in 1932, Converse added his signature to the ankle patch of the All Star shoes. From that point on, they were known as Chuck Taylor All-Stars. Still, Taylor—who reportedly took shameless advantage of his expense account and earned a good salary—is believed to have never received royalties for the use of his name.

In 1969, Taylor was inducted into the Basketball Hall of Fame. The same year, he died from a heart attack on June 23, at the age of 67. Around this time, athletic shoes manufactured by companies like Adidas and Nike began replacing Converse on the court, and soon both Taylor and his namesake kicks were beloved by a different sort of customer.

Still, even though Taylor's star has faded over the decades, fans of his shoe continue to carry on his legacy: Today, Converse sells more than 270,000 pairs of Chuck Taylors a day, 365 days a year, to retro-loving customers who can't get enough of the athlete's looping cursive signature.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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Big Questions
What Is the Difference Between Generic and Name Brand Ibuprofen?
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What is the difference between generic ibuprofen vs. name brands?

Yali Friedman:

I just published a paper that answers this question: Are Generic Drugs Less Safe than their Branded Equivalents?

Here’s the tl;dr version:

Generic drugs are versions of drugs made by companies other than the company which originally developed the drug.

To gain FDA approval, a generic drug must:

  • Contain the same active ingredients as the innovator drug (inactive ingredients may vary)
  • Be identical in strength, dosage form, and route of administration
  • Have the same use indications
  • Be bioequivalent
  • Meet the same batch requirements for identity, strength, purity, and quality
  • Be manufactured under the same strict standards of FDA's good manufacturing practice regulations required for innovator products

I hope you found this answer useful. Feel free to reach out at www.thinkbiotech.com. For more on generic drugs, you can see our resources and whitepapers at Pharmaceutical strategic guidance and whitepapers

This post originally appeared on Quora. Click here to view.

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