WEBVTT - The Science of Glow Sticks

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<v Speaker 1>Deep in the back of your mind. You've always had

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<v Speaker 1>the feeling that there's something strange about reality. There is

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<v Speaker 1>super annoyed death, much nanopartic, mechanical messiahs, punch evolution. On

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<v Speaker 1>Google Play, Spotify and anywhere you get your podcast. Welcome

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<v Speaker 1>to brain Stuff from How Stuff Works. Hey, brain Stuff,

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<v Speaker 1>this is Christian Seger. You have seen glow sticks before.

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<v Speaker 1>I bet they bring a festive glow to Halloween, trick

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<v Speaker 1>or treating and New Year's Eve celebrations. And they are

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<v Speaker 1>a useful gear for explorers, from scuba divers to spelunkers.

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<v Speaker 1>When you find a bunch of people gathered at a

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<v Speaker 1>party in the dark, at least a few of them

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<v Speaker 1>will probably be wielding glow sticks. But what the heck

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<v Speaker 1>are these things and how do they work well? Glow

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<v Speaker 1>sticks are powered by a process called kemma luminescence. Don't

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<v Speaker 1>let the name scare you. Luminescence is just a fancy

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<v Speaker 1>word for any emission of light not caused by heating.

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<v Speaker 1>We see luminescence and stuff like TVs, neon signs and fireflies.

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<v Speaker 1>The chemo luminescence in glow sticks is a pretty simple

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<v Speaker 1>reaction caused by mixing chemical compounds. Compounds are made up

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<v Speaker 1>of different elements bonded together in specific proportions so that

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<v Speaker 1>they can't be mechanically separated. It takes a chemical reaction

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<v Speaker 1>to sort out, for example, the oxygen from the hydrogen

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<v Speaker 1>in water. When you mix a compound with other stuff,

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<v Speaker 1>you can set off that reaction, and as the atoms

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<v Speaker 1>rearrange themselves, they'll either absorb or release energy. If you

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<v Speaker 1>look inside a glow stick, you'll see that there's a

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<v Speaker 1>small glass vial in the tube. This file typically contains

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<v Speaker 1>a hydrogen peroxide solution called the activator. It's floating in

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<v Speaker 1>a solution containing a compound called phenol oxalate ester and

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<v Speaker 1>a fluorescent dye. You still with me, Okay. When you

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<v Speaker 1>snap a glow stick, the vile breaks and the hydrogen

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<v Speaker 1>peroxide reacts with the phenyl oxalate ester, creating two other compounds,

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<v Speaker 1>phenol and a paraoxy acid esther Okay, still with me again. Okay,

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<v Speaker 1>this paraoxy acid stuff is unstable, so it decomposes and

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<v Speaker 1>produces additional phenol. It also produces a cyclic perioxy compound,

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<v Speaker 1>which decomposes to carbon dioxide. This decomposition releases energy to

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<v Speaker 1>the dye. The electrons in the dyes atoms jump to

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<v Speaker 1>a higher level than fall back down, releasing energy in

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<v Speaker 1>the form of light. The other chemicals in the fluorescent

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<v Speaker 1>dye determine the color of this light. All this happens

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<v Speaker 1>within moments of snapping and shaking your glow stick. Depending

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<v Speaker 1>on which compounds are used, the chemical reaction can continue

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<v Speaker 1>for anywhere from just a few minutes to hours. Warmer

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<v Speaker 1>temperatures will accelerate the reaction, making the stick glow brighter,

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<v Speaker 1>but for a shorter amount of time. When it's cooler,

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<v Speaker 1>the reaction will slow down, making the light dimmer, Which

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<v Speaker 1>means that if you want to preserve your light stick,

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<v Speaker 1>put it in the freezer overnight. It won't stop the process,

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<v Speaker 1>but it will slow it down and drag out the reaction.

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<v Speaker 1>So it turns out that there's some pretty nifty science

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<v Speaker 1>behind the humble glow stick. Check it out the next

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<v Speaker 1>time you're scuba diving, partying, or you know whatever it

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<v Speaker 1>is you do in the dark. Check out the brain

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<v Speaker 1>stuff channel on YouTube, and for more on this and

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<v Speaker 1>thousands of other topics, visit how stuff works dot com.