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Be Amazing: Glow in the Dark

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Whether you're looking to become invisible, swallow a sword, quit smoking, find Atlantis, get out of jury duty, buy the Moon, sink a battleship, perform your own surgeries, or become a ninja, our new book Be Amazing covers all the essential life skills! This week, we'll be excerpting a few lessons from the book.


"¢ 1 hand (your own, preferably attached)
"¢ 1 set of fingernails
"¢ 1 powerful photon counter (check your local university research laboratory)
"¢ Photons (don't sweat it, you've already got those)


Some kids want to be princesses or mermaids. But we always thought it'd be fun to be a firefly. (Not the "hey, your tush is blinking on and off" part, mind you, more just the general glowing.) Turns out, we've always been closer to our dream than we realized. In 2005, researchers at Japan's Hamamatsu Photonics Central Research Laboratory revealed that humans already do glow in the dark. Our hands, feet, and foreheads all shine, thanks to photons—tiny, energized packets of light emitted by our skin. According to a Discovery News article on the study, researchers say that fingernails release the most photons, possibly because the material they're made of can function like a prism, scattering light far and wide. So how's it work? The researchers aren't entirely sure. However, using some hand models and a photon counter, they figured out that warm temperatures, increased oxygen, and mineral oil all increase the photon output—making it likely that the glow is caused by chemiluminescence (a fancy word that simply means "light caused by chemical reactions"). Coincidentally, this is same process that makes those firefly fannies flicker.


Besides grade-school wish fulfillment and some serious potential for party tricks, there are actually some practical benefits to this knowledge. Both the Japanese researchers and a second team in Germany say that disease and illness may affect the glow. The Japanese say that sick people emit a dimmer light, while German studies on multiple sclerosis patients revealed that the disease seemed to change the rhythm at which the photon light pulsed. The teams hope that one day their discovery could be used to help doctors diagnose specific disorders in a less invasive way.

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Big Questions
What's the Difference Between Vanilla and French Vanilla Ice Cream?
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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

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Belly Flop Physics 101: The Science Behind the Sting
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Belly flops are the least-dignified—yet most painful—way of making a serious splash at the pool. Rarely do they result in serious physical injury, but if you’re wondering why an elegant swan dive feels better for your body than falling stomach-first into the water, you can learn the laws of physics that turn your soft torso a tender pink by watching the SciShow’s video below.


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