The Unsolved Mystery of Impact Flashes - Smarter Every Day 307

0:00 I'm very excited about this video because it's

0:02 something I've been wanting to learn for years.

0:04 Have you ever noticed when you have two things flying very,

0:08 very fast and they impact in slow motion,

0:11 that little spot right there where they touch for the first time,

0:15 there's often a little flash of light,

0:18 and it looks different at different times,

0:21 but it's there, and we don't really know what it is.

0:25 So today's video is all about that.

0:27 We're going to do experiments here in the garage.

0:29 We're going to see things that we've done in the past.

0:31 For example, years ago, some friends of mine and I,

0:34 we built a supersonic baseball cannon, and we saw it then.

0:46 No, no, no, no, no, am I seeing fire?

0:52 There's fire!?!

0:53 There's fire!!

0:55 That was unexpected That is seriously like striking a match.

1:05 That doesn't compute.

1:06 I kept the glove.

1:07 What causes that?

1:09 We have a leather glove and a leather baseball.

1:12 Why is there a flame?

1:13 Fire?

1:14 What is that?

1:15 Because this also happens when the baseball hits a plastic bucket of sprinkles.

1:20 Two, one.

1:50 So we've got another flash of fire/light, whatever it is.

1:54 Just a couple of frames in the ultra high-speed video.

1:57 But then we also see something like it when

2:01 we fire a bullet versus a Prince Rupert's drop.

2:04 So that's metal versus glass.

2:06 Okay, look at this.

2:16 Bullet versus bullet.

2:18 Both of these are lead.

2:23 [Explosion followed by glass shattering sounds] There's another

2:36 time I've seen flashes when I hit things.

2:39 In this garage, with that high-speed camera right over there,

2:41 I'm going to show you in a minute,

2:43 when you hit Wintergreen lifesavers with a hammer,

2:45 you get sparks, and it's crazy.

2:54 And then perhaps the most fun is when we shot a gallon of mayonnaise.

3:07 That is amazing.

3:08 So we made fire.

3:09 We dieseled mayonnaise.

3:12 Ken is on fire.

3:14 This is the best advertisement for Ken's extra mayonnaise ever.

3:20 Dude.

3:20 And it's not just my stuff.

3:21 Have you ever heard of How Ridiculous on YouTube?

3:24 [Brett] We have 15 giant balloons all in a massive line.

3:27 Oh, my goodness.

3:29 Oh, wow.

3:32 Oh, wow.

3:37 This is Brett with How Ridiculous.

3:39 You guys do all kinds of crazy stuff, right?

3:41 [B] Our channel is called How Ridiculous,

3:43 and I think that accurately describes what we've done for many years.

3:46 [D] I love it, dude.

3:48 What were you doing when this thing happened?

3:53 This light?

3:54 [B] We had two glass spheres, probably,

3:57 I don't know a bit smaller than a bowling ball, I would say.

4:03 We don't know the exact speeds,

4:04 but they were probably going at least 100 miles an hour.

4:08 [D] And what happened?

4:10 [B] Well, miraculously, we got them to collide at all.

4:14 So the balls didn't fit perfectly in the canon.

4:16 So we had basketballs put in first, then the glass balls.

4:20 So then when we fired the glass balls out, in the slowmo, it was super strange.

4:26 One glass ball comes out of the left side,

4:28 and then the other side, a basketball comes out first,

4:31 and one of the guys were with us like,

4:34 did we forget to put the glass ball in the other canon?

4:37 We're like, no.

4:38 So what happened is the basketball must have been not that inflated or whatever.

4:42 And the one on the right side has actually

4:45 come out in front of the glass ball somehow.

4:48 And then it's getting closer and closer to the barrel.

4:51 And we're like, come on, we really need this to happen.

4:56 And then the glass ball just emerges and we celebrate because we know, Oh,

5:00 we're going to see a collision,

5:01 which was one thing we didn't know if it even happened.

5:04 And then as they collide,

5:06 there's this flash of light and you see from the footage,

5:10 we just were completely shocked, surprised.

5:13 We celebrated.

5:14 We just knew we'd captured something really, really epic and rare.

5:18 [D] So you saw a flash of light when they hit?

5:22 [B] Yeah, that's right.

5:24 [D] Another channel you probably heard of, The Slo-Mo Guys,

5:27 Gavin and Dan, fantastic guys, really good friends of mine.

5:29 In fact, In fact, the reason there's paint

5:31 on my ceiling right there is because they did that.

5:34 We've worked together for many years.

5:36 They have a ton of footage.

5:37 I wanted to talk to Gavin about this.

5:38 How are you, man?

5:40 Good to see you.

5:40 [G] Good to see you.

5:41 [D] So you guys were trying to shoot a bullet through a bullet.

5:44 [G] This one was as simple as I wanted to try

5:47 and recreate the shot where one character gets shot through his own bullet,

5:51 basically, by a different bullet.

5:52 [D] What happened when they hit?

5:55 [G] There was just a big flash on impact as one

5:58 bullet went into the the hollowed out area of the bigger bullet,

6:03 and everything mulches together.

6:05 It's so hard to film.

6:06 Even at hundreds of thousands of frames a second, you see it for a few frames.

6:10 [D] So we have flashes of light with leather versus leather,

6:14 leather versus plastic, hammer made out of steel versus sugar.

6:20 We've got metal versus metal, and we have glasses versus glass.

6:23 We've got all these different things happening, and there are a few different

6:27 explanations that could possibly describe these things.

6:30 I think it's pretty obvious that one of these things is not like the others.

6:34 When we hit the lifesavers with a hammer

6:36 and we get this blue light that's happening,

6:38 it seems to be coming from the fracture itself, not from the impact.

6:42 In fact, later in this video on the second channel,

6:45 we shot the lifesavers with a pellet,

6:47 and we saw the blue flashes of light, but something interesting happened.

6:51 We saw the flash of light on the impact surface,

6:54 but we also saw it on the side opposite

6:56 of the impact surface where the lifesaver was ripping apart.

7:00 That tells me that this is happening because

7:02 of the fracture or the cleaving of those crystalline structures.

7:06 And in the video, we refer to this as triboluminescence,

7:09 which has to do with the fracture of a crystalline structure.

7:12 That's fascinating, and that differentiates it

7:15 from these other impact flashes we're seeing.

7:18 So what do you think it was?

7:22 [B] Well, I think initially we had no idea.

7:25 We were like, what is that?

7:27 One of the guys that was with was a high school science teacher.

7:33 And so he ended up having a bit of a look into it,

7:36 and he thought it was this phenomenon called triboluminescence,

7:40 which mysteriously, he's like, it's not fully understood,

7:45 but what we've demonstrated is maybe one

7:48 of the bigger versions of it that anyone's seen.

7:51 Often that's really small things, but we've done it on such a big item

7:55 that it was such a rare occurrence that he was like,

7:57 I think we've seen something that's truly special today.

8:01 [D] So when I first saw the two glass

8:03 balls hit each other on Brett and How Ridiculous video,

8:06 I thought, yeah, that looks like triboluminescence.

8:09 But the more I started reading, the more I realized that triboluminescence,

8:13 apparently, is something that happens on solids with crystalline structures.

8:17 Glass is an amorphous solid.

8:20 It's not a crystalline structure solid, to my understanding.

8:23 I really appreciate the humility here.

8:26 Brett's like, I think this is what it is because that's where I'm at.

8:28 I thought that's what it was as but I don't know.

8:31 There's these other things.

8:32 There's another mechanism called fractoluminescence.

8:35 When things fracture, they cause light.

8:38 There's other things called mechanoluminescence, I think is what it's called.

8:42 There's all these different possibilities that we have here.

8:45 Another one is just straight up friction.

8:48 We've got a baseball coming into a glove really, really hard.

8:51 Is it creating enough friction that it causes light of some sort?

8:55 There's a lot of really big words to describe when light is produced.

8:59 It's almost like the term luminescence is used as a suffix

9:02 for when we get light from something we don't understand.

9:05 Sonaluminescence, fractoluminescence, triboluminescence, mechanicaluminescence.

9:09 All these things seem to be rolled into the thing I did made light,

9:14 and I don't know how.

9:14 I've even thought about electrostatic discharge.

9:17 When two things come close and they have dissimilar charges,

9:19 they'll zap a little bolt of lightning across the gap there.

9:22 There's a lot that this could be.

9:24 I've even thought about the Kopp–Etchells effec.

9:26 That's when you have helicopter blades rotating in a sandy environment,

9:29 and when the sand hits the helicopter rotors, you get little flashes of light.

9:33 There's a lot of things this could be,

9:35 and I want to show you something that happened right here

9:39 in this garage that makes me think I'm starting to understand this.

9:43 Okay, so let me show you a paper over here.

9:46 This is a paper written by a guy named GI Taylor,

9:50 Sir Taylor, the same Taylor that did the ultra-laminar flow.

9:54 Okay, this is a paper by GI Taylor,

9:57 and what he did way back in 1947 is he developed

10:01 a way using math to describe the strength of materials upon impact.

10:08 So basically what he was trying to do is

10:10 he was trying to create a relationship between dynamic stress,

10:13 yield stress and the velocity of a cylinder hitting a flat plate.

10:19 This is called a Taylor impact test.

10:22 So if you're a mechanical engineer and you're

10:24 going to model something using finite element analysis,

10:26 one of the first things you do is a Taylor impact test.

10:30 Which is why we have this crazy device sitting right here in my garage.

10:34 Okay, so this is a twelve gage shotgun, and it's bolted to the steel table here.

10:40 And I've got this crazy box that I designed and had a friend help me make.

10:45 So what happens is you shoot some cylinders

10:48 into this thing and you strip off what's called a sabot.

10:52 Now, this is what the projectile looks like.

10:54 A sabot, what it means is you have a thing on the outside

10:58 of the projectile that takes up the diameter between your projectile,

11:03 which is that rod in the middle, and the side of the barrel of the gun.

11:07 And you can see I designed this sabot so that the sabots would fall away.

11:12 They would pedal away like that.

11:15 And so what happens is this rod will be fired here,

11:19 and it will go into this chamber, and then as it peddles out,

11:22 the sabot will be stripped away by this plate,

11:24 and then it'll go over to this plate and impact this surface.

11:28 So the idea is to take a cylinder and impact this plate.

11:32 This is called a Taylor impact test.

11:35 Now, the velocity that you use or you generate with the gun,

11:41 as you hit that at different velocities you

11:44 should get different amount of yielding, like mushrooming.

11:48 Taylor came up with the original relationships between yield stress,

11:51 and he showed that it was different with dynamic stuff.

11:55 So this was an analytical model, meaning he used math.

11:58 But then he got some friends.

11:59 He's got Carrington here.

12:01 Carrington actually did some of the test,

12:04 and he mushroomed some projectiles, and they took microscopy of the results.

12:08 And he had another guy here named Wiffon, and Wiffon did the same thing.

12:12 And so they were able to come up

12:14 with a relationship between the strength of material,

12:16 the velocity of the cylinder, and how much it squished.

12:20 So let me explain what I was doing when what I'm about to show you happened.

12:24 So I was doing some initial tailor impact tests,

12:27 and I had different cylinders cylinders

12:29 that I had created with different photopolymers.

12:32 There's a company called Formlabs,

12:33 and they have these different plastics that you can 3D print.

12:37 So I made some cylinders, and I was testing the cure time.

12:40 I would cure it for 15 minutes in the oven.

12:43 I'd cure it for 30 minutes.

12:44 I'd cure it for 45 minutes,

12:45 and I started getting really different results with impacts.

12:49 But one of the things I wanted to do is I wanted to test polycarbonate,

12:53 and I wanted to do it really, really fast.

12:55 So David, who was helping me that day,

12:57 and we made a hot load on the shotgun shell,

12:59 so I can change the velocity by how much powder I put in this thing.

13:04 So we made a really, really fast load,

13:06 and we shot a rod of polycarbonate against that flat piece of stainless steel,

13:12 and something amazing happened.

13:14 Two, one, fire.

13:16 [Bang] See what happened.

13:32 Ha ha ha ha ha ha.

13:34 Oh, man.

13:35 That's nuts.

13:38 Dude, look at this.

13:41 We stripped the Sabot.

13:45 It just turned bright.

13:46 Look at that.

13:48 Flash big time, didn't it?

13:50 That's crazy.

13:52 What on Earth?

13:55 What the heck?

13:58 What is even happening?

14:05 And then it splattered like crazy.

14:08 Okay, so that flash was crazy, right?

14:11 I mean, it looks like a little bitty bomb going

14:13 off on one side of the impact surface is there.

14:16 But one thing that made it so

14:19 undeniably different from everything else we've seen,

14:21 glove versus baseball and all this stuff,

14:23 is that it seemed to have a direction to it.

14:26 So when it hit, it almost farted out the side of the impact surface,

14:31 like poof, and it made this little cloud of fire over to one side.

14:41 You see that?

14:42 It clearly has a direction, and that direction seems to somehow be related

14:47 to the obliquity of the cylinder as it impacts the surface.

14:51 Okay, let me try to explain what I'm talking about here.

14:53 I've got a little bitty booger of clay here, right?

14:56 And I've got my rod that I'm going to shoot against the surface.

14:59 If the rod comes along and it hits this thing perfectly straight,

15:04 it's going to squash out the gas that's in between the rod and the surface.

15:09 We're going to get a flat, like a flat, squish, okay?

15:13 But if I don't hit at an orthogonal direction,

15:17 I have a little bit of obliquity to it, meaning I'm tilted like this.

15:22 As it hits, what's going to happen is it's

15:25 going to roll that gas out to one side,

15:28 and you're going to get this little poof out in one direction.

15:32 There's going to be some directionality to it.

15:33 When I told a friend about this, his name is Louis, I said, Man, look at this.

15:37 He's like, Oh, man, look, the little gas.

15:38 I was like, Yeah, I know, right?

15:40 He sent me this paper, Using mechanoluminescence as a low-cost Non-destructive

15:45 Diagnostic Method for Transient Polymer Impact Processes.

15:49 Now, when I looked at this paper,

15:52 what's interesting is the researchers basically built a little thing.

15:56 They said, Look, when we hit plastics versus something.

16:00 We're getting this really big flash.

16:02 And they actually created a device to measure

16:06 where that flash starts and where it moves to.

16:10 And they use that as a way to measure the obliquity of impact.

16:14 And they have this really super cool graph here that I think is really neat.

16:19 So basically, you can see the impacts in the middle there,

16:21 and then it starts pushing out to the side.

16:24 And they use that as a way to measure impact obliquity,

16:27 which I think is really cool.

16:28 So these researchers, Gwo and Chin, in Indiana somewhere, they...

16:35 Oh, at Purdue.

16:36 Indiana somewhere, Purdue.

16:39 Okay, so Chin and Gwo at Purdue, they say it's a meccanoluminescence.

16:42 They say it's the breaking of polymer bonds that create this light.

16:48 I don't know that I agree.

16:50 I think it's the gas.

16:51 So I showed this video to the smartest person I know, Don Pettit.

16:56 Don is a genius.

16:57 He's really good at surface chemistry.

16:59 And Don said, Oh, this is interesting.

17:01 Destin, what if you fill the box with a different

17:05 gas and see if you get a different effect?

17:09 He says, Argon is known to flash very brightly when it's activated,

17:14 so maybe you could do that.

17:16 And so I started looking up some stuff.

17:17 There's this thing called shock ignition.

17:19 And so I don't know how that works because noble gasses, we're told, don't burn.

17:25 They're noble.

17:26 They don't oxidize.

17:27 So the idea of burning argon or igniting argon is interesting.

17:33 It will flash before some of the other gasses will.

17:36 So that's what we're going to do today.

17:37 We're going to put argon over in that box,

17:39 and we're going to see if we can get a different effect.

17:43 I think that's really cool.

17:44 So What I've got here is I've got this LC 320s high-speed camera.

17:51 We're going to get an overall view of what's going on, not a high frame rate.

17:55 And then we're going to use the V2511 here.

17:58 A little loud, but we're going to set it up and we're going

18:01 to try to get a really high frame rate of what's going on.

18:04 But before I do that, I want to try

18:06 to recreate the compression of a gas to make fire.

18:10 I've purchased a couple of little science toys here.

18:13 This is a thing called a fire syringe.

18:16 It's literally a syringe, and we're going to compress the gasses.

18:19 Now, if we look at this paper that I found,

18:23 using the ideal gas law, if you compress, there's a really cool example here.

18:29 If If you compress a gas, depending on the value of Gamma,

18:33 then you can go, let's say we compress it seven times.

18:36 So we go from one atmosphere to seven atmospheres.

18:39 The temperature goes really, really high.

18:42 So just by compressing a gas, and if you do it fast enough,

18:47 you don't lose temperature to a conduction and stuff,

18:50 that's called adiabatic compression.

18:52 That's what a fire syringe does.

18:55 This is just a piston, and it's got an O-ring at the end,

18:58 two O-ring, and this is just a cylinder.

19:00 So the instructions say I'm supposed to put a little cotton fluff in there,

19:05 and I think the cotton fluff is what's going to catch on fire.

19:09 Let me shove that down in there.

19:14 Okay, Good.

19:15 Okay, so let's just put this.

19:17 Okay, so the syringe is in there,

19:19 and this cylinder is charged with just normal room air,

19:23 and we're going to slap this thing and see if we can make fire.

19:29 All right, here we Three, two, one.

19:33 Yeah.

19:35 Let's go look at that in high speed.

19:45 We compressed the gas inside this cylinder.

19:48 And once we did that, because of ideal gas law,

19:50 the temperature goes really high till it exceeds the, I don't know,

19:55 the flame temperature of cotton.

19:56 I guess that's what it is.

19:57 I think because of Rade Bradbury, I know that paper burns Fahrenheit 451.

20:01 So I bet cotton somewhere around there.

20:03 So it got really hot in there.

20:05 But I don't think that was the actual gas is burning.

20:08 That was the cotton burning.

20:09 It looks pretty cool, though.

20:11 This is what's known as adiabatic compression.

20:13 Basically, adiabatic is a fancy word that means

20:15 heat doesn't enter or exit the system.

20:17 And in this case, the system is the tube.

20:20 And because it happens so fast,

20:21 heat doesn't have time to leave the system by being

20:24 absorbed through the side walls of the fire syringe.

20:26 So this is adiabatic compression.

20:29 It looks like it almost squishes everything completely,

20:33 and then you see a little bitty ignition on the cotton just in one little spot.

20:52 Okay, let's put more oxygen in that cylinder and see what happens.

20:54 So I've got two bottles over here.

20:56 I've got nitrogen and I've got oxygen.

20:59 Let's put oxygen in that cylinder.

21:02 Yeah, it's oxygen.

21:04 We'll see if it burns better.

21:05 100% oxygen.

21:08 Okay, so we should have more oxygen in there now.

21:11 I think this is going to work brilliantly.

21:13 Yeah, that worked.

21:17 Absolutely!

21:18 Yes, sir!

21:29 It looks like the spark starts at the moment of most compression,

21:32 and then it's like that is the spark that starts the flame.

21:38 And then when we expand the fire piston, so it's burning all over.

21:42 So we must have got a really, really flammable mixture there.

21:46 Man, it's even lightened my hand up.

21:48 That's so beautiful.

21:49 I love that.

21:51 My hand looks really weird from this angle.

21:54 That's odd.

21:58 Okay, cool.

21:58 Well, let's move on to else.

22:00 I still don't know if this is what we're seeing, but that's pretty bright.

22:04 That's very bright.

22:05 Let's see if we can do Argon and oxygen and see if Argon makes a brighter flame.

22:10 Argon, oxygen.

22:26 Science!

22:26 [Destin Laughs] Three, two, one.

22:30 Okay, that felt brighter.

22:33 That did feel brighter.

22:35 It also hurt my hand.

22:42 Oh, dude, it got so bright so fast.

22:48 My sensor's messed up, but I'm going to call that brighter.

22:53 Interesting.

22:54 Looking back on this, I think I wanted it to be brighter.

22:56 I don't know that it was.

22:57 Maybe I hit it harder with my hand, but I I don't think this is great data.

23:01 Let's just move on.

23:02 Just to double-check because it's a noble gas.

23:04 Let's do just Argon, and I expect no burning.

23:07 Just flood the area with Argon.

23:10 Oh, I did get a smoke, though.

23:16 It's interesting that it vaporizes when you release.

23:21 You can see vapor in there, but I don't think...

23:25 I don't know, maybe it got really hot

23:27 and some moisture on the cotton itself vaporized or something.

23:30 I have no idea.

23:32 I started trying to figure out the way to explain the sponsor for this video,

23:35 and I drew up a Venn diagram of all the things about the product that I like,

23:40 but I realized a lot of it has to do with the people.

23:42 First of all, this is a Canadian company.

23:44 I like Canadians.

23:45 In fact, the thumbnail for this video you're watching,

23:48 probably made by a guy named Jeff from Canada.

23:50 Really tight with Canadians, but the product that they are doing is cool,

23:55 and it ticks all the Destin boxes.

23:56 Number one, machining.

23:59 I have been learning how to CNC machine for a really, really long time now,

24:02 and I just get really excited by the smell of cutting fluid.

24:05 And this product is machined out of aluminum, which is really, really cool.

24:10 The company name is Henson.

24:11 They make a razor for shaving, and it's just really cool.

24:15 You open it up, no plastic.

24:17 Isn't that interesting?

24:18 You don't see that very much anymore.

24:20 Nowadays, when I see a part, I try to figure out how it's made.

24:23 And I can see under the head here on the razor, you can see the CNC tool path.

24:27 So I can see that, and I know that part was CNC, shade,

24:30 but this profile here that holds the razor down in a very precise way,

24:34 that appears to be ground.

24:36 I'm not sure about that.

24:37 It might just be many passes on the CNC at a very fine step over,

24:40 but it's pretty cool.

24:41 With all that, you can see why precision is on my Venn diagram.

24:44 The fact that this curve is held to such a tight

24:47 tolerance all the way across means it supports the blade.

24:50 This makes it great for shaving.

24:51 On my Venn diagram, I've got price.

24:53 The thing about Henson Razors is the only thing you're replacing

24:56 are the little bitty blades that go in the razor itself.

25:00 It's cheap.

25:00 You can buy a whole razor blade for less than a dime.

25:05 It's a very smart way to think long term

25:07 about how you are using a product in your house.

25:10 The last reason I'm excited to use this product is because of nostalgia.

25:14 But this is how my grandfather used to shave.

25:17 He had a razor like this.

25:18 I'm excited to use something like this for the same

25:20 reason I like using film cameras and stuff like that.

25:23 There's something that connects me to the past about using a real safety razor.

25:28 I grew my beard out so I could shoot this ad,

25:32 and I did not realize that a normal safety razor like

25:35 this is better for once your beard is longer like this.

25:39 I hate that I'm telling you this in an ad because

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25:57 I like the Venn diagram that makes

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26:03 Hinsonshaving.com/smarter.

26:03 Give it a shot.

26:06 Okay, so let's go back and see if we can repeat

26:11 the thing that happened when David and I were shooting in the garage.

26:15 So let's get the gun back out and let's

26:18 see if we can make that flash of light again, just for repeatability purposes.

26:23 And I got 12 grains of powder in this shotgun shell.

26:28 I'm going to reconfigure the box So I'm going to make it

26:31 where I can see through this and see through this front side here.

26:36 That's dirty, isn't it?

26:37 And then I've got this shield thing where

26:41 I can contain it on the back side here.

26:46 All right.

26:50 So we've got an armored side, and we have a see through side.

26:55 So I guess now we can just turn the light on here.

26:59 Then that's It's not really bright for normal cameras,

27:00 but we should be able to see it with high speed.

27:03 We'll give it a shot and see if we can make a flash in there.

27:05 That's our goal, right?

27:07 I want to show you how I'm aiming this thing.

27:08 I 3D printed a little laser adapter here,

27:12 and I I'm going to get the laser in the barrel.

27:17 And then over here, if I turn this thing

27:20 on, I can see the laser on my hand there, right?

27:25 Which means I got to make sure that the projectile

27:28 goes through It goes through that and the sabot strip off.

27:32 So it looks like we're aimed pretty well,

27:34 but I always like to just look down the barrel because why not?

27:41 It looks pretty good.

27:42 It looks like it's pretty aligned.

27:44 I don't know if you can see that at all, but yeah, it looks pretty good.

27:48 Drop that plastic in there.

27:49 Don't want it to be too exciting for us.

27:51 Okay, so for a real Taylor impact test,

27:53 what we want to do is we want to measure the length of the projectile.

27:57 This is polycarbonate 75.25 millimeters.

28:02 Should be a 50 cal here.

28:03 You got 12.71 millimeters.

28:06 How much does she weigh?

28:08 11.4 grams.

28:09 Okay, so we can use that information and we can back out,

28:14 squish stuff if we had the high speed in the correct position, which we don't.

28:18 But let's build this projectile here with my 3D printed, sabot.

28:23 One, two, three.

28:26 Okay.

28:27 All right, that works good.

28:29 All So that is a 12 gauge shotgun shell right there.

28:37 I'm going to go over here, grab this bad boy like this.

28:51 All right, we're on there.

29:00 Okay, ready to go.

29:02 Camera trigger right here.

29:06 I'm going to take you off my head for a second.

29:09 No, just ride this out of my head.

29:11 Here we go.

29:16 All right, here we go.

29:17 Three, two, one.

29:17 That's exciting.

29:22 All right, we'll let the smoke settle there.

29:26 Let's go look at what we got.

29:36 We did.

29:37 We got a flash.

29:39 Right there, the whole thing.

29:42 And then you can see it dies out right there.

29:45 That is bizarre.

29:47 We have to go much faster.

29:50 It looks like there was a bunch of rust in the barrel.

29:53 Hadn't shot it in a while.

29:54 It's absolutely what that was.

29:55 There's some flashes right there.

29:57 The sabot hitting the steel.

30:00 Barely cleared the hole.

30:01 Shaved a little bit, actually.

30:02 Still attitude up a little bit.

30:05 Yeah, same thing.

30:07 Weird.

30:09 Oh, we got a flash there when that hit, too.

30:11 Well, we were able to repeat the flash.

30:13 That's good.

30:14 Okay, so we didn't have a high enough frame rate to see exactly what happened.

30:18 But if you look, if we just go through frame by frame,

30:22 you can see that it's rolling to one side.

30:25 It starts when the bottom contacts,

30:27 but the last bit of light we see is on the top.

30:31 And that would fit into the little narrative

30:33 we had earlier with the little booger of clay.

30:35 Remember when it hits and it rolls to one side?

30:38 So that could be a thing.

30:39 I think what we should do now is we

30:41 should tighten the camera up and go a lot faster.

30:43 So I'll take this resolution and I'll just make it a lot smaller,

30:47 and then I'll up the frame rate,

30:49 and we'll see if we can see something again even faster.

30:52 Maybe more powder, too, just because.

30:54 Okay, we're going to do 15 this time.

31:00 All right.

31:01 Fifteen grains of powder.

31:04 It's just a little hot, so I'm going to stay further back.

31:07 Two, one.

31:10 That was hot.

31:13 Goodness, that is so fast.

31:17 There's a lot of chaos.

31:20 I love it.

31:30 It lit up.

31:32 Oh, man.

31:34 Yes, a burst.

31:36 Oh, it maxed it out.

31:38 Definitely saw the gas.

31:40 It was so bright, the sensor didn't know what to do with it.

31:43 Nice.

31:44 And And we had these little secondary flashes as it goes through.

31:48 That really feels like gas.

31:51 And that's the booger theory that I have.

31:55 You see it's lit up on this corner down here,

31:58 and then it rolls out And then it shoots, and then it confuses the sensor.

32:04 Okay, this time I'm going to use an opaque plastic.

32:07 This is PETG, and we've been shooting polycarbonate, so the question is,

32:12 will we also get the little flame pooting out the side.

32:16 This is not the same plastic,

32:17 so it might shatter and not contain the gas, but I don't know.

32:21 But this should tell us if we're seeing a triboluminescent thing

32:24 or if we're compressing a gas in shock, igniting it, maybe.

32:28 74.56, 13.5 grams.

32:33 It's a 16-gram shot.

32:35 Three, two, one.

32:36 I think something weird happened.

32:39 I think the Sabot's came out before the projectile.

32:48 Sabot's.

32:49 Very slow rod.

32:52 So we sheared.

32:57 So my delivery method did not work.

33:00 I would be very surprised if we see any fire on this because it's going so slow.

33:13 We did.

33:13 It made fire.

33:15 Even though it was going slow and it did the...

33:17 That's the booger technique.

33:19 I'm convinced at this point that a lot of times it's gas.

33:22 I did see it in that bullet versus bullet video, like you've seen.

33:25 We did a video a little bit before that.

33:28 It might have even been the same day, but we've got to record.

33:31 But we were just shooting straight

33:33 into steel targets around 800,000 frames a second.

33:37 That gave a little bit more freedom to see the flash because

33:40 it wasn't being squished into a tiny little area of a bullet.

33:42 It was being allowed to spread out more onto this steel plate.

33:46 What's your theory on what that flash is?

33:49 My theory based on what I've read, and I feel like,

33:52 thankfully, I have really smart people in the comments of my videos,

33:53 a lot of people were saying it was just gasses

33:56 in the air being compressed to the point where They're physically lighting up,

34:02 like they're getting that hot briefly.

34:05 Because I was seeing it get squished between all the gaps

34:08 where the hollow point little petals meet around the bullet.

34:12 It was getting fired out of every available space.

34:15 Now, the question is, what gas?

34:19 Is it burning?

34:20 Is something oxidizing?

34:22 Or I've read about this thing called shock ignition of gasses.

34:27 I've read about that.

34:28 I think it's possible that we might be doing that because it's trying

34:32 to move that gas so fast because it's 90 degrees out of phase from the...

34:39 Or it's 90 degrees out of line from the flight axis when it hits,

34:42 it's sending that gas out at an incredibly fast speed.

34:47 Okay, so it created the little puff of fire with PETG, which is a plastic still.

34:53 What happens with wood?

34:55 This is like an insulator.

34:57 It's not going to be triboluminescence.

34:58 If we get fire with wood, then that would be amazing.

35:03 Plus, this is way lighter weight, and we can make it go way faster.

35:06 This feels like bass wood.

35:07 This is going to be nothing.

35:09 4 grams, so it's like 25% of the mass.

35:13 I wonder if we even come up to enough

35:15 chamber pressure just on the shot in terms of ballistics.

35:18 I'm worried about that.

35:19 I don't know what's going to happen here.

35:20 3, 2, 1.

35:22 I want to see.

35:24 [Destin Laughs] Splinters everywhere.

35:28 Oh, man, that's so good.

35:30 Look at that.

35:32 It's just like total carnage.

35:36 Oh, man, if we see a fireball on this, this is going to be nuts.

35:39 What are we even doing?

35:41 This is so fun.

35:43 Okay, so which one we look at first?

35:45 Let's look at the big one first.

35:52 Okay, yeah, we have a lot of unburned powder.

35:54 A ton of unburned powder because we don't get enough

36:00 chamber pressure to actually burn all the powder inside the barrel.

36:06 Man, that is moving.

36:09 Can wood make fire on steel?

36:14 It did it.

36:15 It did it.

36:17 That's nuts.

36:18 It's gas.

36:19 It's got to be gas.

36:21 Yeah, you can see the flame where it contacts first,

36:23 and then it rolls it forward and it looks like it got hotter.

36:26 Not unlike the fire piston, right?

36:29 But it goes out pretty quickly.

36:31 It extinguishes it much quicker.

36:34 We don't see the rolling poof.

36:38 That makes me wonder if the rolling poof has something to do with the material.

36:42 I really want to do Argon,

36:44 and I don't want to asphyxiate myself or suffocate myself.

36:47 So Argon is heavier than air, I'm told.

36:51 So what we're going to do is we're going to open the garage

36:54 here to get some fresh air in, and more importantly, let Argon roll out.

37:00 I don't think I'm going to use that much Argon.

37:03 But what I'm going to do is I want to flood

37:06 this box with Argon now to see if we can get a flash,

37:10 because I have a Wikipedia article over here.

37:14 It's on something called Argon Flash.

37:17 Now, apparently, fancy-pant scientists in real labs,

37:21 not garages, like my garage, they use...

37:24 Check this out.

37:25 Typical Argon flash devices consist of an Argon-filled cardboard or plastic tube

37:31 with a transparent window on one end and an explosive charge on the other end.

37:35 Many explosives can be used, PETN, COMP B, RDX.

37:40 Basically, they put argon in a tube,

37:42 and then they drive it with an explosive It's really impressive.

37:45 Somehow, that makes a big flash.

37:47 Now, what actually happens to make that flash?

37:51 I don't know.

37:52 I don't think it's the argon burning,

37:54 but it's the shock ignition somehow of the argon.

37:58 It requires a detonation in a supersonic shockwave in the argon.

38:02 But I don't know if it's the other gasses in the tube

38:05 that are making the flash or the argon itself that's making the flash.

38:09 I don't know.

38:10 But what I do want to know is if we fire polycarbonate,

38:13 which gave us the most impressive flash,

38:16 into a box that's flooded with argon, what happens?

38:21 I think the way I want to do that is I've got this tube right here.

38:25 This is an argon tank.

38:28 I want to run a tube into the box like this.

38:34 Basically, what I want to do is I want to take

38:37 that hose and I want to pump it in there like that.

38:41 So we're going to put argon in this side over here.

38:45 I'm going to get some tape.

38:46 I'm going to tape the box up so

38:49 that we don't get leakage around all this, and we

38:52 can just fill the box up over here

38:54 with argon and let it flood over into this box.

38:57 And then right before I fire, I'll pull that hose out and then fire

39:02 and trigger the high-speed camera all at one time.

39:06 I'm going to seal up all the Argon leak holes.

39:10 Very scientific.

39:12 Okay, let's turn it up.

39:14 Flooding the box now.

39:15 Gun is ready.

39:17 Come on, pull the hose out.

39:19 Here we go.

39:20 Hose is out.

39:22 Ready to trigger.

39:24 Three, two, one.

39:26 Our gun is off.

39:46 Oh, it looks like it didn't make it through cleanly.

39:49 There was a bright flash for sure.

39:51 There's other things flashing as they hit,

39:53 and those are pieces of the Sabo, are they not?

39:56 It doesn't seem to be any brighter.

39:58 Interesting.

39:59 I I think it's safe to say that we

40:01 didn't see very big flashes there for whatever reason,

40:04 maybe because Argon is a noble gas.

40:06 But what I do know is that I'm starting to feel like

40:09 the gaseous environment that the impact occurs in dictates how big the flash is,

40:14 which means we need to fill the box up with oxygen.

40:17 We're going to make an oxygen-rich environment.

40:27 Welders everywhere.

40:29 They're I'm mad right now.

40:30 All right, there we go.

40:32 Yeah, there's a lot of oxygen in there, that's for sure.

40:35 Polycarbonate.

40:36 Put on the sabot.

40:37 Three, two, one.

40:38 That felt bigger.

40:42 I don't know why.

40:43 Okay.

40:44 All right, cut off the oxygen.

40:46 That did.

40:46 That felt bigger.

41:06 Whoa.

41:08 It's white, and it kept flashing.

41:14 It also hit more orthogonal than normal.

41:16 So I wonder if that's another stuff that hit kept flashing.

41:20 That's pretty big.

41:21 That's a pretty big flash.

41:23 I'd say it was bigger.

41:24 Yeah.

41:25 I feel like the flashes that we're seeing might not be triboluminescence.

41:30 Or mechanoluminescence.

41:33 I think sometimes they are,

41:35 but I feel like this might be adiabatic compression or something like it.

41:42 So we're compressing gas.

41:44 And I think the beautiful thing about that shot

41:46 is it was done at a 90-degree angle.

41:48 It was very orthogonal to the impact surface.

41:51 And I think that makes the gas have to rush out

41:56 from the front of the impact surface faster because If you think about it,

42:01 if you have a string and it's got some

42:03 slack in it and you pull the string really tight,

42:07 if you do the math, if you pull here,

42:13 it takes an infinite amount of force on that string

42:17 to keep it from moving in that direction.

42:19 I guess what I'm saying is tangent is coming into play.

42:22 So the velocity of that gas running out from under

42:28 the impact surface is a function of how orthogonal you hit,

42:36 which makes me interested in the glass balls hitting,

42:42 because no matter where the glass balls hit,

42:46 there's always going to be a 90-degree

42:47 point because they're two tangents on spheres.

42:51 There's always going to be one little spot where you're perfectly tangent.

42:57 This is interesting.

42:58 We have learned things today, and I want to shoot a marble now.

43:02 I'm going to shoot a marble.

43:03 Would you say the light was blue or the light was orange?

43:06 I thought it was like a white, like whitey blue.

43:10 When I first saw yours, I thought that it cracked the whole sphere,

43:14 and then the light from around,

43:16 like the light from the sun was illuminating the balls.

43:19 And then I looked again, I was like, I don't think that's what that is.

43:22 It looks different because it goes away.

43:26 It does.

43:26 Yeah, it does go away very soon.

43:28 Oh, wait.

43:29 Yeah.

43:29 I'm about to I'm watching it right here.

43:30 I'm watching it.

43:32 No, it is quite yellow.

43:34 It's yellow.

43:35 Definitely.

43:35 And there's nothing yellow around, as in it was snowing actively.

43:40 Oh, that's a good point.

43:42 So it was yellow.

43:43 I'm toying with the idea that this is gas.

43:46 This is the nitrogen in the air igniting between the balls.

43:51 And then it's illuminating the glass like a fiber optic.

43:55 It's like a lens, which is what the balls are.

43:57 They're a big lens.

43:58 But see, it It could also be like I'm

44:01 looking at the Wikipedia page on mechanoluminescence and triboluminescence,

44:04 and there's a special one called fractoluminescence.

44:08 So I think it's possible yours is that weird thing, too.

44:11 So I don't know.

44:12 Okay, I want to shoot a marble against the plate now,

44:14 so I have to take the Sabo stripper plate out.

44:17 So let's do that.

44:22 So the idea is to fire the marbles directly through here with, I don't know,

44:27 I guess we'll use some felt or something, and and just impact directly.

44:31 I've got some marbles shoved in shotgun shells here,

44:35 and we're going to see if we can make it do it with glass.

44:39 All right, here we go.

44:41 Oxygen, and lots of it.

44:43 All right, so there's oxygen going in the tank.

44:45 Two marbles.

44:47 Kind of an attempt at making it work there.

44:52 Oxygen in the tank.

44:57 Marbles in the tank.

44:58 Box full of oxygen.

45:00 Three, two, one.

45:03 There's a little flash right there.

45:06 Oh, man, that's crazy.

45:09 So gunpowder was still burning right there.

45:26 Definitely a flash.

45:29 And then the marble hitting the marble behind it flashed as well.

45:39 There's so many things I need to do.

45:40 I need to do a better job of putting the gasses in the box.

45:43 I need to do some research and figure this out.

45:48 But anyway, this was a good exploratory thing.

45:51 So the question is, is it triboluminescence

45:54 or is it adeabatic compression or is it fractoluminescence?

46:01 What is going on?

46:03 I think it has to do with oxygen for sure.

46:05 The question is, when the plastics hit,

46:08 are they particulating and then burning instantly?

46:11 I really think it has a lot to do with the gasses.

46:13 The question that's remaining for me is, are those gasses burning?

46:19 I don't know.

46:20 I'm leaning away from triboluminescence right now,

46:22 and I'm leaning towards gasses.

46:24 I need to do it in a vacuum.

46:26 I need to fire that in a vacuum.

46:28 That's what I need to do.

46:30 Okay, anyway.

46:31 I hope you enjoyed this episode of Smarter Every Day.

46:34 We're just playing and learning,

46:36 and I would love to hear what you think about all this in the comments below.

46:40 You know how on the internet, sometimes people say, Well, actually,

46:43 I would love to hear your well, actuallys down in the comments below.

46:47 So please leave those.

46:48 I'd be grateful.

46:50 Big thanks to everybody that supports

46:51 Smarter Every Day on Patreon at Patreon.com/smartereveryday.

46:55 I am grateful.

46:56 I'm going to keep working on this and more to come.

46:59 Thank you so much.

47:00 I'm Destin.

47:01 You're getting Smarter Every Day.

47:03 Have a good one.

47:04 Bye.