1 00:00:01,920 --> 00:00:06,400 Speaker 1: Welcome to brain Stuff, a production of iHeart Radio. Hey 2 00:00:06,400 --> 00:00:09,440 Speaker 1: brain Stuff. Lauren voc Obam here with another classic episode 3 00:00:09,440 --> 00:00:12,960 Speaker 1: from our former host, Christian Sagar. With Halloween coming up 4 00:00:13,000 --> 00:00:16,640 Speaker 1: and families preparing to engage in the safest possible trigger treating, 5 00:00:17,120 --> 00:00:19,720 Speaker 1: I was thinking about a more traditional piece of trigger 6 00:00:19,760 --> 00:00:23,239 Speaker 1: treat safety gear, the glow stick, and this one, Christian 7 00:00:23,280 --> 00:00:30,520 Speaker 1: breaks down how they work. Hey brain stuff, this is 8 00:00:30,600 --> 00:00:33,720 Speaker 1: Christian Sager. You have seen glow sticks before. I bet 9 00:00:33,760 --> 00:00:36,280 Speaker 1: they bring a festive glow to Halloween, trick or treating 10 00:00:36,280 --> 00:00:38,760 Speaker 1: and New Year's Eve celebrations. And they are a useful 11 00:00:38,800 --> 00:00:42,680 Speaker 1: gear for explorers, from scuba divers to spelunkers. When you 12 00:00:42,720 --> 00:00:44,560 Speaker 1: find a bunch of people gathered at a party in 13 00:00:44,600 --> 00:00:46,919 Speaker 1: the dark, at least a few of them will probably 14 00:00:46,960 --> 00:00:49,800 Speaker 1: be wielding glow sticks. But what the heck are these 15 00:00:49,840 --> 00:00:52,599 Speaker 1: things and how do they work? Well? Glow sticks are 16 00:00:52,600 --> 00:00:56,520 Speaker 1: powered by a process called kemma luminescence. Don't let the 17 00:00:56,600 --> 00:00:59,840 Speaker 1: name scare you. Luminescence is just a fancy word for 18 00:01:00,240 --> 00:01:03,920 Speaker 1: any emission of light not caused by heating. We see 19 00:01:04,000 --> 00:01:08,760 Speaker 1: luminescence and stuff like TVs, neon signs and fireflies. The 20 00:01:08,840 --> 00:01:12,240 Speaker 1: chemo Luminescence in glow sticks is a pretty simple reaction 21 00:01:12,360 --> 00:01:16,520 Speaker 1: caused by mixing chemical compounds. Compounds are made up of 22 00:01:16,560 --> 00:01:20,640 Speaker 1: different elements bonded together in specific proportions so that they 23 00:01:20,680 --> 00:01:24,240 Speaker 1: can't be mechanically separated. It takes a chemical reaction to 24 00:01:24,280 --> 00:01:27,839 Speaker 1: sort out, for example, the oxygen from the hydrogen in water. 25 00:01:28,480 --> 00:01:30,920 Speaker 1: When you mix a compound with other stuff, you can 26 00:01:30,920 --> 00:01:34,600 Speaker 1: set off that reaction, and as the atoms rearrange themselves, 27 00:01:34,680 --> 00:01:39,000 Speaker 1: they'll either absorb or release energy. If you look inside 28 00:01:39,000 --> 00:01:41,600 Speaker 1: a glow stick, you'll see that there's a small glass 29 00:01:41,760 --> 00:01:45,520 Speaker 1: vial in the tube. This file typically contains a hydrogen 30 00:01:45,560 --> 00:01:50,600 Speaker 1: peroxide solution called the activator. It's floating in a solution 31 00:01:50,640 --> 00:01:55,440 Speaker 1: containing a compound called phenol oxalate ester and a fluorescent dye. 32 00:01:55,800 --> 00:01:59,120 Speaker 1: You still with me, Okay. When you snap a glow stick, 33 00:01:59,200 --> 00:02:02,400 Speaker 1: the vile brakes and the hydrogen peroxide reacts with the 34 00:02:02,440 --> 00:02:08,000 Speaker 1: phenyl oxalate ester, creating two other compounds, phenol and a 35 00:02:08,120 --> 00:02:13,680 Speaker 1: paraoxy acid esther Okay, still with me again? Okay. This 36 00:02:13,840 --> 00:02:17,960 Speaker 1: para oxy acid stuff is unstable, so it decomposes and 37 00:02:18,040 --> 00:02:23,119 Speaker 1: produces additional phenol. It also produces a cyclic perioxy compound, 38 00:02:23,400 --> 00:02:28,800 Speaker 1: which decomposes to carbon dioxide. This decomposition releases energy to 39 00:02:28,840 --> 00:02:31,960 Speaker 1: the dye. The electrons in the dyes atoms jump to 40 00:02:32,000 --> 00:02:35,240 Speaker 1: a higher level than fall back down, releasing energy in 41 00:02:35,280 --> 00:02:38,520 Speaker 1: the form of light. The other chemicals in the fluorescent 42 00:02:38,600 --> 00:02:42,480 Speaker 1: dye determine the color of this light. All this happens 43 00:02:42,480 --> 00:02:46,400 Speaker 1: within moments of snapping and shaking your glow stick. Depending 44 00:02:46,440 --> 00:02:49,919 Speaker 1: on which compounds are used, the chemical reaction can continue 45 00:02:49,960 --> 00:02:53,680 Speaker 1: for anywhere from just a few minutes to hours. Warmer 46 00:02:53,680 --> 00:02:57,560 Speaker 1: temperatures will accelerate the reaction, making the stick glow brighter, 47 00:02:57,600 --> 00:03:00,640 Speaker 1: but for a shorter amount of time. When it's cooler, 48 00:03:00,720 --> 00:03:04,080 Speaker 1: the reaction will slow down, making the light dimmer, which 49 00:03:04,120 --> 00:03:06,640 Speaker 1: means that if you want to preserve your light stick, 50 00:03:06,880 --> 00:03:10,000 Speaker 1: put it in the freezer overnight. It won't stop the process, 51 00:03:10,120 --> 00:03:13,240 Speaker 1: but it will slow it down and drag out the reaction. 52 00:03:13,639 --> 00:03:16,760 Speaker 1: So it turns out that there's some pretty nifty science 53 00:03:16,800 --> 00:03:19,519 Speaker 1: behind the humble glow stick. Check it out the next 54 00:03:19,560 --> 00:03:23,120 Speaker 1: time you're scuba diving, partying, or you know, whatever it 55 00:03:23,200 --> 00:03:30,520 Speaker 1: is you do in the dark. Today's episode was written 56 00:03:30,520 --> 00:03:33,120 Speaker 1: by Ben Bolin and produced by Tyler clang. For more 57 00:03:33,160 --> 00:03:35,360 Speaker 1: on this and lots of other glowing topics, visit how 58 00:03:35,360 --> 00:03:38,120 Speaker 1: stuff works dot com. Brain Stuff is production of iHeart 59 00:03:38,160 --> 00:03:40,880 Speaker 1: Radio or more podcasts my heart Radio, visit the iHeart 60 00:03:40,920 --> 00:03:43,600 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 61 00:03:43,600 --> 00:03:44,280 Speaker 1: favorite shows.