CLOSE
Original image

How Do Glowsticks Glow?

Original image

Picture an atom. Now picture that atom getting excited. Maybe its birthday is coming up. Anyway, when an atom or a molecule gets excited, its electrons' energy levels go up. When the electrons fall back down to their normal state, they release energy in the form of photons, a basic unit of light.

For most of the lights we make and use, those excited atoms release heat as well as light when they’re coming back down. Sometimes you want the latter without the former, a “cold light” like the kind made by fireflies. In the early 1960s, U.S. military and industry scientists knew that the key to making cold light on their own was chemiluminescence, the emission of light from chemical reactions. They just weren’t sure which materials and reactions they were after (luminol had been around for a little while, but had limited applications).

Edwin Chandross, a chemist at Bell Labs in Murray Hill, N.J., was one of the researchers working on the problem.

He wondered if peroxides – chemical compounds with an oxygen-oxygen single bond that could potentially liberate a lot of energy in some reactions - might do the trick. He tried a few experiments and found that hydrogen peroxide combined with oxalyl chloride and a fluorescent dye produced the cold chemical light he was after. The reaction’s efficiency was only about 0.1% (far short of fireflies’ near 90%), but it was a start.

Chandross began corresponding with Michael Rauhut at American Cyanamid in Stamford, Connecticut, and Rauhut’s team expanded on Chandross’ research, searching for ways to make the light bright enough for practical use. They eventually came up a diphenyl oxalate ester that reacted with hydrogen peroxide to make a bright light, trademarked their creation as Cyalume, and rolled it out on the market.

The reaction that happens inside a glowstick goes a little something like this:

- The typical glowstick contains an oxalate ester and dye solution within a plastic stick, and hydrogen peroxide within a small, fragile vial in the middle of the stick.

- When you bend the stick, the vial breaks open, and all the chemicals come together. The oxalate ester and hydrogen peroxide react, sometimes with the help of a catalyst, to form a peroxyacid ester and phenol.

- The peroxyacid ester decomposes to form more phenol and carbon dioxide, producing energy that excites all the molecules floating around in this little party, which then release photons, making the stick glow.

Since the glowstick’s invention, researchers have been fiddling around with this reaction, searching for fluorescing dyes to make different colors (green and yellow are said to be easy to make, while a good purple is near impossible) and adjusting the concentrations of the chemicals to brighten the glow or prolong its life.

American Cyanamid eventually sold its chemical light division, Omniglow. The R&D department there has continued to expand the uses and capabilities of glowsticks, creating luminescent intubating scopes and researching more efficient reactions and glow sticks that work at below-freezing temperatures.

Original image
iStock
arrow
Big Questions
What's the Difference Between Vanilla and French Vanilla Ice Cream?
Original image
iStock

While you’re browsing the ice cream aisle, you may find yourself wondering, “What’s so French about French vanilla?” The name may sound a little fancier than just plain ol’ “vanilla,” but it has nothing to do with the origin of the vanilla itself. (Vanilla is a tropical plant that grows near the equator.)

The difference comes down to eggs, as The Kitchn explains. You may have already noticed that French vanilla ice cream tends to have a slightly yellow coloring, while plain vanilla ice cream is more white. That’s because the base of French vanilla ice cream has egg yolks added to it.

The eggs give French vanilla ice cream both a smoother consistency and that subtle yellow color. The taste is a little richer and a little more complex than a regular vanilla, which is made with just milk and cream and is sometimes called “Philadelphia-style vanilla” ice cream.

In an interview with NPR’s All Things Considered in 2010—when Baskin-Robbins decided to eliminate French Vanilla from its ice cream lineup—ice cream industry consultant Bruce Tharp noted that French vanilla ice cream may date back to at least colonial times, when Thomas Jefferson and George Washington both used ice cream recipes that included egg yolks.

Jefferson likely acquired his taste for ice cream during the time he spent in France, and served it to his White House guests several times. His family’s ice cream recipe—which calls for six egg yolks per quart of cream—seems to have originated with his French butler.

But everyone already knew to trust the French with their dairy products, right?

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

Original image
NASA/JPL-Caltech/Space Science Institute
arrow
Big Questions
How Many Rings Does Saturn Have?
Original image
NASA/JPL-Caltech/Space Science Institute

Of all the planets surrounded by rings, Saturn is the most famous. These planetary rings are massive enough that Galileo was able to see them using a simple telescope way back in 1610, though it wasn't until half a century later that another scientist was able to figure out what the "arms" Galileo saw actually were. NASA has since called them "the most recognized characteristic of any world in our solar system."

So how many rings does Saturn have, anyway? If you can see them from your backyard, there must be a lot, right?

Scientists don't know for sure exactly how many rings Saturn has. There are eight main, named ring groups that stretch across 175,000 miles, but there are far more than eight rings. These systems are named with letters of the alphabet, in order of their discovery. (Astronomers have known about ring groups A, B, and C since the 17th century, while others are newer discoveries. (The most recent was just discovered in 2009.)

The rings we can see in images of the planet—even high-resolution images—aren't single rings, per se, but are in fact comprised of thousands of smaller ringlets and can differ a lot in appearance, showing irregular ripples, kinks, and spokes. The chunky particles of ice that make up Saturn's rings vary in size from as small as a speck of dust to as large as a mountain.

While the gaps between Saturn's rings are small, the 26-mile-wide Keeler Gap is large enough to contain multiple moons, albeit very small ones. The largest ring system—the one discovered in 2009—starts 3.7 million miles away from Saturn itself and its material extends another 7.4 million miles out, though it's nearly invisible without the help of an infrared camera.

Researchers are still discovering new rings as well as new insights into the features of Saturn's already-known ring systems. In the early 1980s, NASA's Voyager missions took the first high-resolution images of Saturn and its rings, revealing previously unknown kinks in one of the narrower rings, known as the F ring. In 1997, NASA sent the Cassini orbiter to continue the space agency's study of the ringed planet, leading to the discovery of new rings, so faint that they remained unknown until Cassini's arrival in 2006. Before Cassini is sent to burn up in Saturn's atmosphere in September 2017, it's taking 22 dives through the space between the planet and its rings, bringing back new, up-close revelations about the ring system before the spacecraft dives to its death.

Though it's certainly possible to see Saturn's rings without any fancy equipment, using a low-end telescope at your house, that doesn't mean you always can. It depends on the way the planet is tilted; if you're looking at the rings edge-on, they may look like a flat line or, depending on the magnification, you might not be able to see them at all. However, 2017 happens to be a good year to see the sixth planet, so you're in luck.

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

SECTIONS

More from mental floss studios