WEBVTT - How do fireworks work? 0:00:08.640 --> 0:00:11.399 Hey, Daniel, I have an explosive question for you. Oh 0:00:11.520 --> 0:00:13.360 are you gonna ask me about how to blow things up? 0:00:13.920 --> 0:00:16.520 Isn't that what you do every day anyways at the 0:00:16.560 --> 0:00:19.440 particle Collider. I mean, like on a more everyday basis. 0:00:19.480 --> 0:00:22.680 How do you feel about summer fireworks? M I used 0:00:22.720 --> 0:00:25.560 to love fireworks as a kid. I used to love him. 0:00:25.680 --> 0:00:27.600 You don't like him anymore. I guess I just used 0:00:27.600 --> 0:00:31.720 to have a more sparkling personality. Well, you can be 0:00:31.760 --> 0:00:34.680 a real fire cracker, trust me. I'm hoping one day 0:00:34.720 --> 0:00:38.800 that all blows over. Very bright and ploughing personality. Also, 0:00:38.800 --> 0:00:41.239 you seem to make a lot of noise. So far, 0:00:41.360 --> 0:00:44.040 I've never been fired from work for setting off fireworks. 0:00:59.400 --> 0:01:01.400 I am hor I'm a cartoonist and the creator of 0:01:01.440 --> 0:01:04.800 PhD comics. Hi. I'm Daniel. I'm a particle physicist and 0:01:04.840 --> 0:01:07.320 a professor at U C Irvine, and I really do 0:01:07.480 --> 0:01:09.759 love blowing things up. Oh yeah, do you do that 0:01:09.880 --> 0:01:13.440 as a hobby, not just in your work. Yeah, I'm 0:01:13.440 --> 0:01:19.480 pitching a new reality show called Will It Explode? Interesting? 0:01:19.760 --> 0:01:23.080 I guess if you don't like your fingers or hands, 0:01:23.120 --> 0:01:25.800 that sounds like a great show to join. I think 0:01:25.840 --> 0:01:28.320 everybody would want to tune in and see how much 0:01:28.360 --> 0:01:30.280 T and T does it take to blow up this 0:01:30.440 --> 0:01:33.839 or that, a banana, a watermelon, a coconut. You remind 0:01:33.880 --> 0:01:36.160 me of my cousin when we were a little I 0:01:36.319 --> 0:01:39.000 could love to blow things up with and had that 0:01:39.000 --> 0:01:42.399 work out for your cousin. All right, he's still alive, 0:01:42.560 --> 0:01:45.520 still has all his fingers, he managed to survive success, 0:01:45.560 --> 0:01:47.640 And I hope his job lets him blow things up 0:01:47.640 --> 0:01:51.720 on a regular basis like mine actually fixes planes now, 0:01:51.840 --> 0:01:53.840 so I hope, I hope it doesn't blow things up. 0:01:57.160 --> 0:01:59.520 His job is the opposite now of his childhood passion. 0:01:59.720 --> 0:02:03.160 That's keep things are blowing up, please because but anyways, 0:02:03.160 --> 0:02:05.600 Welcome to our podcast, Daniel and Jorge Explain the Universe, 0:02:05.640 --> 0:02:07.880 a production of our Heart Radio. We're the only thing 0:02:07.920 --> 0:02:10.360 we want to blow up is your mind. As we 0:02:10.480 --> 0:02:13.520 delve into the secrets of the universe and try to 0:02:13.639 --> 0:02:17.119 understand how it all works. We take apart the very 0:02:17.200 --> 0:02:20.520 fabric of space and time and reality and seek to 0:02:20.639 --> 0:02:24.359 understand it at the smallest level. How does the universe 0:02:24.400 --> 0:02:27.480 really work? What are its most fundamental bits, and how 0:02:27.520 --> 0:02:31.399 do those weave themselves together to make this incredible exciting 0:02:31.480 --> 0:02:35.160 and explosive universe that we enjoy every summer. Yeah, it 0:02:35.280 --> 0:02:37.959 is an exploding universe. As we know, dark energy is 0:02:38.000 --> 0:02:41.960 making the universe accelerated and expand faster and faster each day. Literally, 0:02:42.040 --> 0:02:44.519 it is sort of exploding, and it's also full of sparkly, 0:02:44.639 --> 0:02:47.919 amazing and colorful things for us to wonder about. That's right, 0:02:47.960 --> 0:02:50.480 although thinking about the Big Bang and the expansion of 0:02:50.480 --> 0:02:53.480 the universe as an explosion does tend to lead people 0:02:53.520 --> 0:02:56.080 to thinking about things the wrong way. A lot of 0:02:56.120 --> 0:02:58.760 people think about the Big Bang is like this tiny 0:02:58.880 --> 0:03:01.560 dot of matter which then blew up into space which 0:03:01.600 --> 0:03:04.480 already existed. So these days our vision of the early 0:03:04.560 --> 0:03:07.560 universe isn't as much like a firecracker as it is 0:03:07.680 --> 0:03:11.360 like a big rubber sheet getting stretched everywhere. Then maybe 0:03:11.360 --> 0:03:13.480 you shouldn't have called it the Big Bang. I mean, 0:03:13.600 --> 0:03:15.720 it's in the name Dead Hill. The Big Bang sounds 0:03:15.720 --> 0:03:18.519 like an explosion. It does indeed sound like an explosion, 0:03:18.520 --> 0:03:20.840 and so we'll add to the list of horribly named 0:03:21.000 --> 0:03:24.800 astronomical concepts. I mean, you just misnamed the entire universe. 0:03:24.840 --> 0:03:27.760 I mean, just a small error there. We should have 0:03:27.800 --> 0:03:32.000 called it the Big Stretch. But it is interesting. Do 0:03:32.000 --> 0:03:34.000 you see your job as blowing things up? You said 0:03:34.000 --> 0:03:36.960 earlier you like blowing things up, and you're a particle physicist, 0:03:37.040 --> 0:03:40.080 which means you collide things, because that is that also 0:03:40.160 --> 0:03:42.680 the same thing as blowing things up. Yeah, Well, the 0:03:42.720 --> 0:03:45.640 reason we collide things is to blow them up. Like 0:03:45.720 --> 0:03:48.400 you want to know what's inside a proton, you can't 0:03:48.440 --> 0:03:50.720 like put it on the table and tease it apart 0:03:50.760 --> 0:03:53.240 with pliers. What you gotta do is smash two of 0:03:53.240 --> 0:03:55.680 them together, blow them up, and see what comes out 0:03:55.840 --> 0:03:59.040 from that explosion. So every collision inside the large Hadron 0:03:59.040 --> 0:04:02.200 collider is like mini explosion, and we do millions of 0:04:02.200 --> 0:04:05.160 them per second. Also, it's more like a smashing. I 0:04:05.160 --> 0:04:09.000 don't know if it's exploding. Really, well, what happens if 0:04:09.000 --> 0:04:12.120 you smash two watermelons together? They explode? Don't they know? 0:04:12.480 --> 0:04:15.920 They're just mash If you put a grenade inside of 0:04:15.920 --> 0:04:18.160 a watermelon, that's an explosion. Well, if I could put 0:04:18.200 --> 0:04:20.520 a grenade inside a proton, I would totally do it. 0:04:21.360 --> 0:04:23.159 But what would the grenade be made out of? Daniel 0:04:24.000 --> 0:04:29.400 grenade on obviously delicious dessert explosions. But I'm also a 0:04:29.400 --> 0:04:32.800 big fan of aerial explosions, though maybe more so as 0:04:32.800 --> 0:04:35.279 a kid. Yeah, you mentioned that before, So you don't 0:04:35.279 --> 0:04:37.839 like fireworks anymore. Like you go to display and what 0:04:37.920 --> 0:04:40.080 either you close your ears or you close your eyes. 0:04:40.240 --> 0:04:41.760 I used to be really amazed by them. I thought 0:04:41.760 --> 0:04:43.480 they were fantastic when I was a kid, And now 0:04:43.560 --> 0:04:45.640 I don't know if I've just gotten old and grumpy, 0:04:45.920 --> 0:04:49.280 but they're just sort of less impressive. They're beautiful now, 0:04:49.320 --> 0:04:51.760 and they're they're getting more complicated now, right Like now 0:04:51.800 --> 0:04:54.080 they can you know, like sync them up with music 0:04:54.240 --> 0:04:57.640 and do all kinds of things like multiple explosions that 0:04:57.760 --> 0:05:01.000 make different formations up there in the sky. And as 0:05:01.080 --> 0:05:03.960 we come up on July four, it reminds me that 0:05:04.040 --> 0:05:07.400 the best fireworks display I ever saw for July four 0:05:07.560 --> 0:05:11.200 for American Independence Day was actually in Switzerland. Oh yeah, 0:05:11.240 --> 0:05:14.520 they make everything better out there, more precise. There's a 0:05:14.600 --> 0:05:18.560 huge American population in Switzerland, and so in Geneva they 0:05:18.560 --> 0:05:22.600 have an incredible July fourth fireworks display. In Geneva. It's 0:05:22.640 --> 0:05:25.279 like outside the US, but they go all out and 0:05:25.320 --> 0:05:28.520 have a life orchestra which plays music and coordination with 0:05:28.560 --> 0:05:31.640 the fireworks. It really was pretty impressive. So you do 0:05:31.720 --> 0:05:34.560 like fireworks then, Yeah, occasionally I've been known to enjoy 0:05:34.600 --> 0:05:40.200 them occasionally. I mean it, who doesn't like fireworks? Many dogs, 0:05:40.680 --> 0:05:44.400 dogs and physicists, dogs and jaded physicists. Well, when you 0:05:44.400 --> 0:05:46.440 blow things up for a living, you know you expect 0:05:46.440 --> 0:05:48.560 the higher standard. I guess right, right, when you smash 0:05:48.640 --> 0:05:52.800 things for a living, you mean you know you said 0:05:52.800 --> 0:05:55.400 you got the name for the origin of the universe wrong. 0:05:55.480 --> 0:05:59.000 Maybe you should be a little more careful. Yeah, point taken. 0:05:59.040 --> 0:06:02.000 But anyways, fireworks are pretty amazing and incredible and part 0:06:02.000 --> 0:06:04.640 of our tradition and part of how the world celebrates 0:06:04.680 --> 0:06:08.160 big events like independence and New Year's But it's kind 0:06:08.160 --> 0:06:10.839 of interesting to think about how that actually works. Yeah, 0:06:10.839 --> 0:06:13.360 it's an example of how we have put our knowledge 0:06:13.400 --> 0:06:16.000 of how the universe works to work for us. We 0:06:16.120 --> 0:06:18.719 manipulate these things and take advantage of them to create 0:06:18.720 --> 0:06:21.960 these incredible bright displays. But to do so you have 0:06:22.040 --> 0:06:25.279 to know some physics and some chemistry. Yeah. So today 0:06:25.279 --> 0:06:32.200 on the program, we're we tackling the question how the 0:06:32.279 --> 0:06:37.000 fireworks work, or I guess more technically, how the fireworks 0:06:37.120 --> 0:06:40.480 fire and work? And can you set off fireworks at 0:06:40.480 --> 0:06:44.040 work without getting fired? It is a bit of an oxymoron. 0:06:44.040 --> 0:06:46.960 It is, isn't it? In one word, you have the firing. 0:06:47.080 --> 0:06:51.920 You can fire someone and they can also work exactly fireworks. 0:06:52.640 --> 0:06:58.280 It's like we works, but we don't work. Yeah, firecrashed. Yeah, 0:06:58.279 --> 0:07:00.560 it's pretty interesting to think about how far works work. 0:07:00.720 --> 0:07:03.320 But I think you sort of said earlier that it's 0:07:03.320 --> 0:07:05.599 the result of our knowledge at the universe, But really, 0:07:05.600 --> 0:07:07.960 sort of fireworks weren't you know? It didn't come from 0:07:08.040 --> 0:07:10.680 us understanding anything about the universe, right, I think it 0:07:10.960 --> 0:07:13.440 was mostly just people playing around with and maybe figuring 0:07:13.480 --> 0:07:15.800 out that some things blew up. You're absolutely right that 0:07:15.880 --> 0:07:18.080 fireworks have been with us for a lot longer than 0:07:18.360 --> 0:07:21.600 our understanding of the chemistry and the physics of them, 0:07:22.120 --> 0:07:24.960 that's for sure. In fact, I think they're invented in China, 0:07:25.360 --> 0:07:28.640 like more than a thousand years ago. So firework has 0:07:28.640 --> 0:07:30.360 been a part of a human existence for a very 0:07:30.440 --> 0:07:33.160 very long time, longer than we've had modern chemistry, that's 0:07:33.200 --> 0:07:35.400 for sure. How they were invented, do you think someone 0:07:35.440 --> 0:07:37.960 would just falling around with things and then that they 0:07:38.000 --> 0:07:40.600 blew up on them, and then the person next to 0:07:40.600 --> 0:07:43.520 them was like, oh, that's interesting. I love thinking about 0:07:43.560 --> 0:07:47.120 how people stumbled into understanding of how things work. You 0:07:47.280 --> 0:07:49.920 think about like think about like the metallurgy of swords. 0:07:50.240 --> 0:07:53.000 People have really refined techniques for exactly how to make 0:07:53.280 --> 0:07:56.400 very hard steal well before we had any understanding of 0:07:56.440 --> 0:07:58.400 the chemistry of it. And I think that must have 0:07:58.480 --> 0:08:02.320 just been accidentally disc covered people making mistakes and then discovering, 0:08:02.360 --> 0:08:04.640 oh wow, look this is pretty awesome. So yeah, I 0:08:04.640 --> 0:08:08.880 think gunpowder probably discovered accidentally. Interesting what we'll get into 0:08:09.120 --> 0:08:11.000 what how it works and how it was discovered. But 0:08:11.040 --> 0:08:12.480 as you said, the history of it is that it 0:08:12.520 --> 0:08:15.640 was invented in China about a thousand years ago. People 0:08:15.640 --> 0:08:17.360 are not sure. I guess there are no records of it. 0:08:17.480 --> 0:08:19.480 There are some records of it, and you can look 0:08:19.480 --> 0:08:22.960 at like Chinese historical drawings and visitors who went to 0:08:23.040 --> 0:08:25.800 China of course to see evidence of it for more 0:08:25.840 --> 0:08:28.520 than a thousand years. It's pretty cool. Do you think 0:08:28.520 --> 0:08:31.760 they were they invented as a like a celebration display 0:08:31.880 --> 0:08:34.720 or more for warfare. They were initially invented for celebration, 0:08:34.760 --> 0:08:38.959 they think, and then later applied for war. Like everything now, 0:08:39.080 --> 0:08:42.840 it's usually the other way around these days, right, the 0:08:42.880 --> 0:08:46.960 Internet was started for the military darpened it. Yeah, it 0:08:47.000 --> 0:08:49.480 was originally darpen it and then it became you know, 0:08:49.600 --> 0:08:54.120 cat videos and podcasts. I see, so you're saying fireworks, 0:08:54.120 --> 0:08:56.560 eventually we'll just turn into cat videos. That would be 0:08:56.559 --> 0:09:00.120 super impressive. If they can do a cat video with explosives, 0:09:00.160 --> 0:09:02.640 engineers could get to it. That is the goal. The 0:09:02.679 --> 0:09:05.760 way every life form eventually evolves into a crab, every 0:09:05.800 --> 0:09:09.120 form of weapon eventually evolves into a cap video. Well, 0:09:09.160 --> 0:09:11.400 and then eventually it came to Europe, but not until 0:09:11.480 --> 0:09:14.640 much later. That's right, in the fourteenth century is when 0:09:14.679 --> 0:09:17.080 Europe started to use fireworks and developed the same sort 0:09:17.080 --> 0:09:19.240 of technology, and then somehow it made it to American 0:09:19.320 --> 0:09:22.480 and became part of July fourth our celebrations. Yeah, but 0:09:22.559 --> 0:09:24.960 blowing things up have been part of how people celebrate 0:09:25.040 --> 0:09:29.840 things for a long long time. Watermelons, fireworks, hopefully not cats, 0:09:30.040 --> 0:09:33.960 the beginning of the universe with a big bang. Well, 0:09:33.960 --> 0:09:36.520 it's interesting because it's something that's in our everyday lives, 0:09:36.600 --> 0:09:38.520 almost or at least once or twice a year. But 0:09:38.559 --> 0:09:40.440 I mean, not a lot of people know how it works. 0:09:41.000 --> 0:09:43.040 And so as usual, we were wondering what would happen 0:09:43.080 --> 0:09:44.680 if you ask people on the street or on the 0:09:44.720 --> 0:09:47.880 internet how fire works work. So thanks very much to 0:09:47.960 --> 0:09:51.720 everybody out there who answers random questions about the Big Bang, 0:09:51.800 --> 0:09:54.640 the origin of the universe, and how fireworks work without 0:09:54.679 --> 0:09:57.840 any chance to repair. We really love you participating. And 0:09:57.880 --> 0:10:00.199 if you're out there and you've never joined in leaves, 0:10:00.280 --> 0:10:02.800 don't be shy right to us. Two questions at Daniel 0:10:02.840 --> 0:10:05.400 and Jorge dot com. You want to hear from you, 0:10:05.559 --> 0:10:06.960 So think about it for a second. How do you 0:10:06.960 --> 0:10:10.840 think fireworks work? Here's but to say, there's some small 0:10:10.880 --> 0:10:14.319 amount of gunpowder in a tube that two explodes, creating 0:10:14.320 --> 0:10:17.439 a big old pressure wave in a tiny, little enclosed area. 0:10:17.559 --> 0:10:20.960 So that exerts a force on something that's gonna get 0:10:20.960 --> 0:10:23.480 shot into the air or or I guess whichever way 0:10:23.520 --> 0:10:27.360 you point it at a friend or a building or 0:10:27.360 --> 0:10:29.120 a car. And if it's one of those big fireworks, 0:10:29.120 --> 0:10:31.600 it probably has a second charge in it. You can 0:10:31.880 --> 0:10:33.480 put a bunch of different metals in there that are 0:10:33.520 --> 0:10:38.440 gonna burn at different colors, and that would be what 0:10:38.520 --> 0:10:40.000 makes all the pretty colors in the sky after that 0:10:40.040 --> 0:10:43.160 second charge goes off. It's my understanding that you have 0:10:43.280 --> 0:10:48.480 a shell that is made up of black powder or 0:10:48.559 --> 0:10:54.280 gunpowder or something explosive, surrounded by a little things, little 0:10:54.320 --> 0:10:58.080 balls of something that is dipped in as salt, like 0:10:58.240 --> 0:11:01.959 a strontium or um, you know, some sort of metal 0:11:02.080 --> 0:11:05.079 that when it heats up, it glows in a specific color. 0:11:05.480 --> 0:11:12.160 Fireworks show differently because I think they're chemicals within each 0:11:12.920 --> 0:11:19.400 display that ones exploded will reflect light differently, and that's 0:11:19.400 --> 0:11:23.000 what produces all of the beautiful colors. Fireworks are like 0:11:23.240 --> 0:11:26.800 an amazing confluence of chemistry and physics. There's all of 0:11:26.800 --> 0:11:29.080 this energy that you have stored in the in the 0:11:29.120 --> 0:11:32.400 propellant and the explosive that you're using, and then once 0:11:32.440 --> 0:11:35.280 you get it up there, you're using different chemicals to 0:11:35.600 --> 0:11:39.040 create all the wild colors and effects. It's early rockets 0:11:39.160 --> 0:11:42.560 and payloads of joy. Oh, I'm so excited if you 0:11:42.600 --> 0:11:45.680 are talking about fireworks. I love them, and yet I 0:11:45.720 --> 0:11:50.360 am not sure how they work. There's something explosive and 0:11:50.480 --> 0:11:55.800 different elements create different colors, I think, though I have 0:11:55.920 --> 0:11:57.720 no idea how they make those really cool ones with 0:11:57.760 --> 0:12:01.840 the different sparkles and sounds that sound like they're crackling. 0:12:01.960 --> 0:12:06.280 I love those. I think fireworks work by firing stuff 0:12:06.320 --> 0:12:09.360 out in the back of them. Um due to one 0:12:09.360 --> 0:12:11.880 of the two lads, which I can't remember. That means 0:12:11.920 --> 0:12:15.800 that due to the oppositey action, the firework will go 0:12:15.920 --> 0:12:20.120 up and then I guess some dynamite explodes. It makes 0:12:20.120 --> 0:12:25.040 it nice color in shape. Well. I always imagine fireworks 0:12:25.040 --> 0:12:28.479 as like a tiny, little colorful controlled bomb that exploded 0:12:28.600 --> 0:12:31.880 only once you reach the sky. But maybe it works differently. 0:12:32.240 --> 0:12:36.840 Fireworks work by oxidizing flammables with a specific chemical that 0:12:36.880 --> 0:12:40.240 emits light at a certain frequency, creating the different colors 0:12:40.280 --> 0:12:43.880 we see. All right, some pretty technical sounding answers. I 0:12:43.960 --> 0:12:47.640 like this one that said the confluence of chemistry and physics. 0:12:47.880 --> 0:12:51.240 That sounds almost poetic. Little do they know chemists and 0:12:51.240 --> 0:12:54.560 physicist never confluenced exactly. I was like, that's so naive, man, 0:12:54.600 --> 0:12:57.360 They're like all the way it went together. They're on 0:12:57.400 --> 0:12:59.640 the other side of campus, man, Like they do totally 0:12:59.679 --> 0:13:03.080 different physics from us. Chemistry might as well be sociology 0:13:03.120 --> 0:13:06.320 from our perspective. Is there a stereotype of like a 0:13:06.400 --> 0:13:09.360 chemist and physicist? Like one of them were are sandals? 0:13:09.400 --> 0:13:13.160 The other ones? Where where's socks and slippers? I don't know. 0:13:13.360 --> 0:13:15.880 Eye protection chemistry always wearing eye protection when I see 0:13:15.880 --> 0:13:19.079 them around the building. I see interesting the chemistry, you see. 0:13:19.120 --> 0:13:22.120 I have these huge labs of like thirty grad students 0:13:22.440 --> 0:13:24.560 pumping a different synthesis of this and that and the 0:13:24.600 --> 0:13:27.560 other thing. It's really amazing and impressive. No, I don't 0:13:27.600 --> 0:13:29.720 understand most of it. You sound a little jealous there. Well, 0:13:29.800 --> 0:13:31.920 you see I chemistry. Don't you have like thirty grads 0:13:31.920 --> 0:13:34.839 fouds yourself. I only have eight grad students right now, 0:13:35.120 --> 0:13:38.040 thank you. But the u CE chemistry department is top notch. 0:13:38.240 --> 0:13:40.319 Somebody who graduated from here won the Nobel Prize in 0:13:40.400 --> 0:13:42.920 chemistry last year. I think always an opportunity to plug 0:13:43.000 --> 0:13:47.800 u C. I. But yeah, it's pretty interesting. Everyone seems 0:13:47.840 --> 0:13:50.400 to have an idea that it's about exploding things, which 0:13:50.640 --> 0:13:53.280 sort of makes sense, and it may be a little obvious. 0:13:53.520 --> 0:13:56.679 There's an explosion involved in gunpowder. Yeah, but fireworks are 0:13:56.760 --> 0:13:59.040 much more than just an explosion. Right. If you've been 0:13:59.080 --> 0:14:01.600 to a recent fire work display, you've seen that they 0:14:01.640 --> 0:14:05.720 can do incredible stuff. They're sparkly, they're shimmery, they have 0:14:05.800 --> 0:14:09.359 different colors, they can make smiley faces. I've seen butterflies, 0:14:09.360 --> 0:14:11.920 I've seen palm trees. It's really amazing and what they 0:14:11.960 --> 0:14:15.280 can do up there in the sky. Yeah, Well for today, 0:14:15.400 --> 0:14:18.240 let's break it down maybe a little bit further, right, 0:14:18.280 --> 0:14:21.160 because when we think about fireworks and you know, celebrations 0:14:21.200 --> 0:14:23.800 like New Year's or July fourth, there's really sort of 0:14:23.880 --> 0:14:26.960 three things that people think about. Right. There's the firecrackers, 0:14:27.240 --> 0:14:29.920 the kind of just explode and make noise that they 0:14:30.360 --> 0:14:32.120 usually the kind of people throughout in the middle of 0:14:32.160 --> 0:14:35.240 the street. There are sparklers, which are the you know 0:14:35.280 --> 0:14:38.600 sticks that you hold and they had a lot of sparkles. 0:14:38.640 --> 0:14:40.760 And then there's a big fireworks displays that go up 0:14:40.760 --> 0:14:43.240 in the sky and give us all these amazing colors. Yeah, 0:14:43.280 --> 0:14:45.600 and those things are actually all connected. So that's a 0:14:45.640 --> 0:14:47.560 great order to tackle them in. All right, Well we'll 0:14:47.560 --> 0:14:50.320 start with the firecrackers, Daniel, How what is the what 0:14:50.440 --> 0:14:53.400 are the basics of a fire cracker? Firecracker is really 0:14:53.440 --> 0:14:57.920 pretty simple stuff. It's essentially just gunpowder in a little 0:14:57.960 --> 0:15:01.560 tube with a fuse, so it's just like a mini bomb, right, 0:15:01.600 --> 0:15:04.360 and all it does is rapidly burn the gunpowder, the 0:15:04.400 --> 0:15:07.440 black powder, and explode and give you a loud noise 0:15:07.480 --> 0:15:09.800 and a little bit of smoke. M M. But I 0:15:09.800 --> 0:15:12.520 guess the question is what is gunpowder? Yeah, I've wondered 0:15:12.560 --> 0:15:15.720 this for a long time. Actually gunpowder is this weird 0:15:15.840 --> 0:15:19.040 mixture of stuff. So it's got some charcoal in it, 0:15:19.120 --> 0:15:24.040 like of it is sulfur, and then seventy of it 0:15:24.080 --> 0:15:26.840 is this stuff called saltpeter, which I always thought was 0:15:26.880 --> 0:15:29.080 really weird, like who is Peter and why is he 0:15:29.160 --> 0:15:32.880 so salty? But it's basically just like a funny historical 0:15:32.960 --> 0:15:37.520 name for a chemical potassium nitrate. Interesting, maybe salt Peter 0:15:37.760 --> 0:15:42.080 is the cousin of Sweet John. I think they're both 0:15:42.080 --> 0:15:46.280 blues singers. Sounds like, you know, Mississippi Saltpeter or something. Alright, 0:15:46.320 --> 0:15:49.360 So to make gunpowder, you just need charcoal, sulfur and 0:15:49.400 --> 0:15:53.360 potassium nitrate. Now what what's potassium nitrate? It's like p 0:15:54.160 --> 0:15:57.520 K can end something. Yeah, So the chemical formula is 0:15:57.680 --> 0:16:01.760 k N O three. So got potassium, it's got nitrogen, 0:16:01.840 --> 0:16:04.880 it's got oxygen, and it occurs in nature as a 0:16:04.920 --> 0:16:08.200 mineral and it's a useful source of nitrogen and it's 0:16:08.280 --> 0:16:12.320 used in fertilizers and also for like obviously rocket propellants 0:16:12.360 --> 0:16:14.600 and fireworks, and they also put some of it in 0:16:14.760 --> 0:16:18.880 process meats. Wait what, Oh, that's right, like a curing agent. 0:16:19.840 --> 0:16:22.600 And like the reason that like red hot dogs are 0:16:22.720 --> 0:16:26.080 red is because the potassium nitrate. Well, does that mean 0:16:26.120 --> 0:16:28.520 hot dogs are flammable and they'll explode? I can light 0:16:28.560 --> 0:16:33.000 them up? Is that why they're called hot dogs? I 0:16:33.000 --> 0:16:34.360 don't know. But the first thing I would do is 0:16:34.400 --> 0:16:36.680 take two hot dogs and accelerate them together. See if 0:16:36.680 --> 0:16:39.480 that can generate a nice hot dog smash. Yeah, that 0:16:39.520 --> 0:16:42.720 sounds like a great use of a billion dollar facility 0:16:42.720 --> 0:16:46.440 in Geneva. Maybe for July July four party smash hot 0:16:46.480 --> 0:16:51.080 dogs and so and sell them to little kids. Okay, 0:16:51.080 --> 0:16:54.920 so that's gunpowder, charcoal, sulfur and potassium nitrate. Now why 0:16:54.920 --> 0:16:57.160 does that light up? Why does that explode? Mm? And 0:16:57.200 --> 0:16:59.760 so what's happening anytime you have an explosion is just 0:16:59.800 --> 0:17:03.000 a rapid release of energy and like one shell of 0:17:03.120 --> 0:17:06.080 exploding material and sets off the next one. It's sort 0:17:06.119 --> 0:17:07.639 of just like a fire in the sense of like 0:17:07.760 --> 0:17:09.919 the way one piece of wood ignites the next piece, 0:17:10.160 --> 0:17:12.480 but here it happens very very rapidly, So you have 0:17:12.480 --> 0:17:16.119 a rapid emission of energy, usually faster than the speed 0:17:16.119 --> 0:17:19.160 of sound. That's what an explosive is. It's usually supersonic. 0:17:19.240 --> 0:17:22.800 So that's the basics of an explosion. The details depend 0:17:22.840 --> 0:17:26.240 on exactly what you have in there, how rapidly it oxidizes, 0:17:26.359 --> 0:17:29.200 how rapidly it releases that energy. Wait, so maybe it 0:17:29.240 --> 0:17:31.840 take us through that process then, like what's what's going on? 0:17:31.880 --> 0:17:34.480 What is oxidizing? Name what do you need like a 0:17:34.520 --> 0:17:37.320 flame to get it started? Right? So fundamental process that's 0:17:37.359 --> 0:17:41.200 happening here chemically is something called combustion, right, which technically 0:17:41.240 --> 0:17:45.679 is just like high temperature exothermic, which means it's releasing energy. 0:17:46.119 --> 0:17:48.919 So you're doing some chemical change to what's going on inside. 0:17:48.960 --> 0:17:51.640 You're changing the molecules and their bonds in a way 0:17:51.640 --> 0:17:54.560 that releases some stored energy, the same way like when 0:17:54.560 --> 0:17:57.560 you burn gasoline, right, it releases energy that used to 0:17:57.600 --> 0:18:00.760 be stored inside the fuel. So here it's an exothermic 0:18:00.800 --> 0:18:04.200 reaction is called a redox reaction because it reacts with 0:18:04.240 --> 0:18:08.520 some oxidant. Often that's atmospheric oxygen. Like fire needs oxygen, right, 0:18:08.520 --> 0:18:11.639 it's part of the chemical process to release the energy 0:18:11.680 --> 0:18:14.760 that's bound inside the wood. Here, you also need some 0:18:14.880 --> 0:18:17.280 source of oxygen, but there's not enough oxygen in the 0:18:17.280 --> 0:18:19.720 atmosphere to get this reaction going and to have it 0:18:19.760 --> 0:18:22.840 happen so fast. You wanted to start in the center 0:18:22.880 --> 0:18:26.400 and then explode outwards. And you know they can't access 0:18:26.480 --> 0:18:29.000 enough oxygen to just take that from the air, so 0:18:29.000 --> 0:18:32.240 you have to provide a source of oxygen to make 0:18:32.240 --> 0:18:35.840 this whole explosion happen. But I guess you know, like 0:18:35.880 --> 0:18:41.040 what's the actual reaction, Like why do you need potassium, nitrogen, charcoal, carbon, 0:18:41.280 --> 0:18:44.160 and sulfur? Like what's going on? Is something transforming into 0:18:44.200 --> 0:18:46.639 something else or something breaking apart? What do you need 0:18:46.680 --> 0:18:50.080 those three ingredients? You start with potassium, nitrate and carbon 0:18:50.119 --> 0:18:53.040 and sulfur, and then you get out the same bits 0:18:53.080 --> 0:18:55.280 but arrange it in a different pattern, So you get 0:18:55.320 --> 0:18:59.359 carbon dioxide, you get atmospheric nitrogen, which is into and 0:18:59.400 --> 0:19:02.000 then you get put passium sulfide. So you end up 0:19:02.000 --> 0:19:05.400 with the same bits but just rearranged in different molecules 0:19:05.560 --> 0:19:07.960 in a way that takes less energy. So you've released 0:19:08.080 --> 0:19:11.000 some of the energy. WHOA, that's a pretty that sounds 0:19:11.040 --> 0:19:13.639 like a pretty complicated reaction. They're like you put in 0:19:13.680 --> 0:19:15.639 three things and then three other things come out, but 0:19:15.680 --> 0:19:19.440 they're totally different. The fire somehow triggers that. Yeah, it's 0:19:19.440 --> 0:19:23.359 actually a complicated multi stage reaction. Doesn't all happen at once, 0:19:23.800 --> 0:19:25.960 and it's something people are still sort of studying and 0:19:26.000 --> 0:19:29.000 trying to optimize, and they've come up recently with more 0:19:29.040 --> 0:19:32.080 fancy versions of gunpowder or like don't release any smoke. 0:19:32.280 --> 0:19:35.119 So it's a complicated multi stage reaction. Well, what you 0:19:35.119 --> 0:19:38.880 mean multistage, Like the first the potassium nitrate reacts with this, 0:19:38.960 --> 0:19:41.720 and then something else, then the charcoal comes in or 0:19:41.720 --> 0:19:44.200 what exactly, it's multi steps. You don't have all three 0:19:44.240 --> 0:19:46.399 things happening at the same time. First you have the 0:19:46.400 --> 0:19:49.720 potassium nitrate, which breaks down and releases the oxygen, and 0:19:49.720 --> 0:19:52.359 then that oxygen is crucial for the next stages of 0:19:52.400 --> 0:19:55.560 the reaction. But I guess you need something to start 0:19:55.560 --> 0:19:57.720 it right, Like you need that spark. And so when 0:19:57.760 --> 0:20:00.639 you light up a match, you're burning the stuff in 0:20:00.680 --> 0:20:04.800 the match, which is creating temperature I guess heat, right, 0:20:04.840 --> 0:20:08.080 then high kinetic energy things that are moving really fast, 0:20:08.080 --> 0:20:09.760 and then when you put it close to the gunpowder, 0:20:10.160 --> 0:20:13.159 that's amount triggers the reaction. Well, these things are in 0:20:13.200 --> 0:20:15.679 a stable state as is, right, Gunpowder just sitting on 0:20:15.760 --> 0:20:18.359 the table doesn't give off the energy that's stored in 0:20:18.400 --> 0:20:21.720 it the same way gasoline doesn't or wood doesn't. But 0:20:21.840 --> 0:20:23.640 if you can trigger this reaction, if you can get 0:20:23.640 --> 0:20:26.159 it hot enough to trigger this reaction, you will release 0:20:26.200 --> 0:20:28.399 some of its internal energy. So it's sort of like 0:20:28.680 --> 0:20:30.800 a ball trapped on a shelf. You gotta give it 0:20:30.800 --> 0:20:32.960 a little push so it'll fall off and release all 0:20:32.960 --> 0:20:35.600 of that potential energy. And so this is all trapped 0:20:35.640 --> 0:20:38.600 stored inside these chemicals. If you provide some heat to 0:20:38.680 --> 0:20:41.040 kick it off, then it will release a lot of 0:20:41.080 --> 0:20:44.240 that internal stored energy, and that release will then trigger 0:20:44.320 --> 0:20:47.560 more release from the adjacent molecules, so it builds on itself. 0:20:47.560 --> 0:20:50.080 It's a chain reaction that way, right, And I imagine 0:20:50.119 --> 0:20:53.240 it's also you need like a certain amount of heat, right, 0:20:53.320 --> 0:20:55.560 Like I'm sure if it's sitting there out there in 0:20:55.560 --> 0:20:58.359 the open, there are air molecules hitting it, and some 0:20:58.400 --> 0:21:00.600 of them are partly hitting it be fast, and it 0:21:00.720 --> 0:21:03.480 is maybe causing some reactions, but maybe not enough to 0:21:03.520 --> 0:21:06.760 really get that snowball of rolling exactly, Although you can 0:21:06.880 --> 0:21:09.960 have that happen naturally from like lightning strikes. Fires can 0:21:09.960 --> 0:21:12.560 start in the woods from lightning strikes. But you're right, 0:21:12.600 --> 0:21:15.080 air molecules don't trigger this because they don't deposit enough 0:21:15.160 --> 0:21:17.800