0 00:00:00,000 --> 00:00:30,000 Dear viewer, these subtitles were generated by a machine via the service Trint and therefore are (very) buggy. If you are capable, please help us to create good quality subtitles: https://c3subtitles.de/talk/353 Thanks! 1 00:00:09,540 --> 00:00:10,710 Yeah, my name is Sarah. 2 00:00:11,850 --> 00:00:14,039 I come from the region here I live in the 3 00:00:14,040 --> 00:00:15,240 region of Kalsu. 4 00:00:16,860 --> 00:00:19,739 I work with lasers in my 5 00:00:19,740 --> 00:00:21,929 in my work and I develop things like 6 00:00:21,930 --> 00:00:24,309 this. This is an industrial laser system 7 00:00:24,310 --> 00:00:26,639 for marking pieces of metal, 8 00:00:26,640 --> 00:00:28,799 pieces of plastic in a in a line 9 00:00:28,800 --> 00:00:31,469 where products go through. 10 00:00:31,470 --> 00:00:33,929 In my free time, as you mentioned, I'm 11 00:00:33,930 --> 00:00:36,029 in the fab lab where we 12 00:00:36,030 --> 00:00:37,349 developed or build 13 00:00:38,370 --> 00:00:40,349 the laser sound, which is an open source 14 00:00:40,350 --> 00:00:41,789 project. And 15 00:00:42,900 --> 00:00:44,999 so I have two laser sites, one network 16 00:00:45,000 --> 00:00:47,609 and one one in my free time. 17 00:00:47,610 --> 00:00:50,729 And so 18 00:00:50,730 --> 00:00:52,979 I did an experiment with the CO2 19 00:00:52,980 --> 00:00:54,959 laser in the fab lab. 20 00:00:54,960 --> 00:00:57,809 I wanted to know what happens 21 00:00:57,810 --> 00:01:00,809 when the beam goes on the skin 22 00:01:00,810 --> 00:01:01,709 and the result. 23 00:01:01,710 --> 00:01:04,079 So I went to a butcher and 24 00:01:04,080 --> 00:01:06,779 bought a piece of pigskins, 25 00:01:06,780 --> 00:01:08,909 five, six millimeter thick, 26 00:01:08,910 --> 00:01:11,219 and I put it on the laser and switched 27 00:01:11,220 --> 00:01:13,289 on the fume extraction and said, 28 00:01:13,290 --> 00:01:15,959 OK, don't know where to start. 29 00:01:15,960 --> 00:01:16,960 And 30 00:01:18,960 --> 00:01:20,519 this I come to later. 31 00:01:20,520 --> 00:01:22,230 So and I ended up with this 32 00:01:24,210 --> 00:01:25,210 on the top, 33 00:01:26,520 --> 00:01:28,679 you see 10 percent input 34 00:01:28,680 --> 00:01:30,989 power at 35 00:01:30,990 --> 00:01:33,659 a thousand millimeters minutes 36 00:01:33,660 --> 00:01:35,369 writing speed. 37 00:01:35,370 --> 00:01:37,529 Second line on the on the top left 38 00:01:37,530 --> 00:01:39,809 is 50 percent of 39 00:01:39,810 --> 00:01:42,329 power and the third is 100 percent. 40 00:01:42,330 --> 00:01:44,909 When you look closely, you can see 41 00:01:44,910 --> 00:01:47,309 that the the O's and 42 00:01:47,310 --> 00:01:50,009 zeros that 43 00:01:50,010 --> 00:01:52,139 meet the skin was lays 44 00:01:52,140 --> 00:01:54,149 it out and fell down. 45 00:01:54,150 --> 00:01:56,129 So then I was scared. 46 00:01:56,130 --> 00:01:58,289 I was really scared. 47 00:01:58,290 --> 00:01:59,309 It smelled like hell. 48 00:01:59,310 --> 00:02:01,499 I was close to vomiting. 49 00:02:01,500 --> 00:02:03,210 And I thought, Wolf, I 50 00:02:04,800 --> 00:02:06,089 didn't expect this. 51 00:02:06,090 --> 00:02:08,309 And the second on the left 52 00:02:08,310 --> 00:02:10,259 hand side, three rows 53 00:02:11,430 --> 00:02:13,769 where with 8000 mm. 54 00:02:13,770 --> 00:02:15,300 Minute marking speed. 55 00:02:17,130 --> 00:02:19,259 I don't want to have this 56 00:02:19,260 --> 00:02:21,749 on my skin or in my eyes, 57 00:02:21,750 --> 00:02:23,939 definitely not this 58 00:02:23,940 --> 00:02:25,979 I can't describe, I can't imagine the 59 00:02:25,980 --> 00:02:28,049 pain and the consequences 60 00:02:28,050 --> 00:02:29,789 of medical consequences. 61 00:02:29,790 --> 00:02:30,790 So therefore, 62 00:02:33,780 --> 00:02:35,879 you are responsible for 63 00:02:35,880 --> 00:02:38,579 what you do with lasers. 64 00:02:38,580 --> 00:02:41,099 You everyone is personally responsible 65 00:02:41,100 --> 00:02:43,439 to wear the safety goggles, 66 00:02:43,440 --> 00:02:46,169 to take care that no beam goes 67 00:02:46,170 --> 00:02:47,730 goes out of the compartment. 68 00:02:50,550 --> 00:02:52,659 So whenever you hurt yourself, don't 69 00:02:52,660 --> 00:02:54,179 take me reliable for it. 70 00:02:54,180 --> 00:02:55,889 Oh, Sarah didn't warn me about this 71 00:02:55,890 --> 00:02:57,959 matter. No, absolutely not. 72 00:02:57,960 --> 00:02:59,609 You are responsible. 73 00:02:59,610 --> 00:03:02,130 So read the standards, 74 00:03:03,240 --> 00:03:05,429 read more, read some other 75 00:03:05,430 --> 00:03:06,459 literature. 76 00:03:06,460 --> 00:03:08,190 Think about what you're going to do 77 00:03:09,360 --> 00:03:10,949 seriously. Think about what you're going 78 00:03:10,950 --> 00:03:13,079 to do. It is so dangerous or 79 00:03:13,080 --> 00:03:14,789 can be dangerous. 80 00:03:14,790 --> 00:03:16,979 And yeah, obviously, 81 00:03:16,980 --> 00:03:18,959 before you switch on the laser system, 82 00:03:18,960 --> 00:03:21,599 please switch on your brain. 83 00:03:21,600 --> 00:03:22,739 This is vital. 84 00:03:22,740 --> 00:03:25,019 This is really important. 85 00:03:25,020 --> 00:03:26,020 So 86 00:03:27,240 --> 00:03:29,519 by the way, this was done with a CO2 87 00:03:29,520 --> 00:03:31,469 laser at ten thousand six hundred 88 00:03:31,470 --> 00:03:33,569 nanometers and 89 00:03:33,570 --> 00:03:35,399 I don't know the output, the optical 90 00:03:35,400 --> 00:03:37,229 output power, but the input power was 91 00:03:37,230 --> 00:03:38,639 maximum 100 watt. 92 00:03:38,640 --> 00:03:40,739 So I 93 00:03:40,740 --> 00:03:42,929 guess 60, 70 watt 94 00:03:42,930 --> 00:03:44,369 output power, optical. 95 00:03:46,980 --> 00:03:47,980 Not nice. 96 00:03:49,920 --> 00:03:51,539 I came across some 97 00:03:53,040 --> 00:03:55,259 preparation to this talk, I came across 98 00:03:56,490 --> 00:03:59,069 some some nice pictures 99 00:03:59,070 --> 00:04:01,379 and some nice stories I want to share, 100 00:04:03,180 --> 00:04:05,459 especially what is very vulnerable 101 00:04:05,460 --> 00:04:08,579 is the eyes, obviously 102 00:04:08,580 --> 00:04:09,719 skin you can repair. 103 00:04:09,720 --> 00:04:12,059 You go to to to the to the hospital 104 00:04:12,060 --> 00:04:14,220 emergency room and you get fixed up 105 00:04:15,230 --> 00:04:17,458 with your eyes. It's more difficult, 106 00:04:17,459 --> 00:04:19,979 especially in the visible range 107 00:04:19,980 --> 00:04:20,980 of light. 108 00:04:22,019 --> 00:04:24,809 The top left image, 109 00:04:24,810 --> 00:04:27,029 there was a guy who had to set up 110 00:04:27,030 --> 00:04:29,429 at home at 111 00:04:29,430 --> 00:04:31,649 one vitalism, a blue laser 112 00:04:31,650 --> 00:04:33,749 system, and it 113 00:04:33,750 --> 00:04:34,750 was standing on a chair 114 00:04:36,630 --> 00:04:38,909 and he wanted he did 115 00:04:38,910 --> 00:04:40,529 something. 116 00:04:40,530 --> 00:04:42,899 I read the story was very vague, 117 00:04:42,900 --> 00:04:45,089 but he wanted to switch it off. 118 00:04:45,090 --> 00:04:47,009 So he got off his chair where he was 119 00:04:47,010 --> 00:04:49,409 sitting to to tinker with the system 120 00:04:49,410 --> 00:04:51,539 and he stumbled 121 00:04:51,540 --> 00:04:52,799 upon a cable. 122 00:04:52,800 --> 00:04:54,959 And the whole laser set up 123 00:04:54,960 --> 00:04:58,079 from from the other tower fell over. 124 00:04:58,080 --> 00:05:00,779 And somehow he got him. 125 00:05:00,780 --> 00:05:02,379 He got the beam for his eye. 126 00:05:03,450 --> 00:05:05,639 This is one year 127 00:05:05,640 --> 00:05:07,919 after the accident. 128 00:05:07,920 --> 00:05:10,229 And I mean, imagine 129 00:05:10,230 --> 00:05:12,299 you have this huge spot 130 00:05:12,300 --> 00:05:14,039 where you see nothing. 131 00:05:14,040 --> 00:05:16,259 I mean, the the brain can 132 00:05:16,260 --> 00:05:18,119 can adapt. 133 00:05:20,450 --> 00:05:22,819 But I mean, such 134 00:05:22,820 --> 00:05:25,069 a black spot on 135 00:05:25,070 --> 00:05:28,159 one eye, you can't ignore this, 136 00:05:28,160 --> 00:05:30,079 you look someone in the face and you see 137 00:05:30,080 --> 00:05:32,299 black spots, you look on the traffic 138 00:05:32,300 --> 00:05:33,709 lights, you see black spot. 139 00:05:35,930 --> 00:05:38,119 So this was a very, very bad 140 00:05:38,120 --> 00:05:40,189 mishap on the 141 00:05:40,190 --> 00:05:43,159 right, the right image is 142 00:05:43,160 --> 00:05:44,209 less energy 143 00:05:45,350 --> 00:05:47,300 with the near infrared laser. 144 00:05:48,440 --> 00:05:50,259 This is a typical Yayuk laser. 145 00:05:50,260 --> 00:05:52,490 A thousand sixty four nanometers. 146 00:05:53,990 --> 00:05:56,419 That's a wavelength I work with at work. 147 00:05:57,680 --> 00:06:00,259 That was a short, 148 00:06:00,260 --> 00:06:01,819 short pulse. 149 00:06:01,820 --> 00:06:04,069 And this is something you might 150 00:06:04,070 --> 00:06:05,509 recover from. 151 00:06:05,510 --> 00:06:07,879 Not that the retina recovers, 152 00:06:07,880 --> 00:06:09,979 but that your brain adapts 153 00:06:09,980 --> 00:06:12,699 to. Oh, I 154 00:06:12,700 --> 00:06:14,269 like you to take away this. 155 00:06:14,270 --> 00:06:15,469 I ignore this spot. 156 00:06:15,470 --> 00:06:16,790 I interpolate the image. 157 00:06:19,850 --> 00:06:22,099 I did the laser talk 158 00:06:22,100 --> 00:06:24,649 in autumn in in Darmstadt 159 00:06:24,650 --> 00:06:27,349 at the city and 160 00:06:27,350 --> 00:06:29,659 I haven't had the CO2 161 00:06:29,660 --> 00:06:30,979 laser at that time. 162 00:06:30,980 --> 00:06:33,019 I just had my laser from work. 163 00:06:33,020 --> 00:06:35,299 So I did the same experiment 164 00:06:35,300 --> 00:06:37,249 I took. I got from a butcher this piece 165 00:06:37,250 --> 00:06:38,300 of pigskin 166 00:06:39,440 --> 00:06:41,539 placed in the focus area and 167 00:06:41,540 --> 00:06:43,669 said, OK, 20 at full throttle. 168 00:06:43,670 --> 00:06:45,589 Let's see what happens. 169 00:06:45,590 --> 00:06:47,779 And after one minute of marking 170 00:06:47,780 --> 00:06:49,849 a rectangle on the skin, 171 00:06:49,850 --> 00:06:50,919 I saw nothing. 172 00:06:50,920 --> 00:06:53,119 So well, I mean, I put 173 00:06:53,120 --> 00:06:55,279 my power meter, so 20 months. 174 00:06:55,280 --> 00:06:56,809 So everything was right. 175 00:06:56,810 --> 00:06:59,779 Then I took my my thermal imaging camera. 176 00:06:59,780 --> 00:07:01,969 And so, Wolf, this is 177 00:07:01,970 --> 00:07:02,970 getting hot 178 00:07:05,000 --> 00:07:07,009 on the left. 179 00:07:07,010 --> 00:07:09,979 You see, on the on the left image, 180 00:07:09,980 --> 00:07:12,350 the range goes to 57 degrees. 181 00:07:13,640 --> 00:07:16,099 You don't see anything, but it goes into 182 00:07:16,100 --> 00:07:19,909 the tissue and heats up from the inside. 183 00:07:19,910 --> 00:07:21,149 This must be very painful. 184 00:07:21,150 --> 00:07:23,269 I don't want to to do it. 185 00:07:23,270 --> 00:07:24,620 Sometimes I'm tempted to 186 00:07:26,060 --> 00:07:28,279 go through the beam, but I'm not going 187 00:07:28,280 --> 00:07:30,799 to do it just to to see this and 188 00:07:30,800 --> 00:07:31,800 to have a sensation 189 00:07:33,110 --> 00:07:35,059 on the right hand side on the on the 190 00:07:35,060 --> 00:07:37,669 bottom, this big 191 00:07:37,670 --> 00:07:39,799 red this glowing blob was 192 00:07:39,800 --> 00:07:42,619 two, three minutes after marking 193 00:07:42,620 --> 00:07:45,139 this what you see on the left hand side 194 00:07:45,140 --> 00:07:47,449 and maybe you can read it. 195 00:07:47,450 --> 00:07:50,149 What I've what I've written below. 196 00:07:50,150 --> 00:07:51,199 This is Hollowell. 197 00:07:51,200 --> 00:07:52,200 HelloWallet, 198 00:07:53,780 --> 00:07:55,969 you see nothing on the skin, but 199 00:07:55,970 --> 00:07:57,529 you can see it in the in the thermal 200 00:07:57,530 --> 00:07:58,530 image. 201 00:08:01,220 --> 00:08:03,319 I find this very impressive 202 00:08:03,320 --> 00:08:05,659 and shows even 203 00:08:05,660 --> 00:08:07,819 with lower with 204 00:08:07,820 --> 00:08:09,919 lower energy, you can 205 00:08:09,920 --> 00:08:12,019 do a lot of damage. And this gives 206 00:08:12,020 --> 00:08:14,419 at that wavelength. 207 00:08:14,420 --> 00:08:16,819 This gives a lot of damage inside 208 00:08:16,820 --> 00:08:18,379 the tissue. 209 00:08:18,380 --> 00:08:20,509 Imagine you have you have your magnifying 210 00:08:20,510 --> 00:08:22,649 glass in summer and you 211 00:08:22,650 --> 00:08:24,859 you you have the sun in the focus 212 00:08:24,860 --> 00:08:27,079 and you have your skin starts 213 00:08:27,080 --> 00:08:29,299 burning. And this is only minimum 214 00:08:29,300 --> 00:08:30,889 light power. 215 00:08:30,890 --> 00:08:32,298 You have whatever. 216 00:08:32,299 --> 00:08:33,559 How big the magnifiers. 217 00:08:36,840 --> 00:08:38,399 I don't know, give it a shot. 218 00:08:40,679 --> 00:08:42,779 It's very easy, it's very easy, 219 00:08:42,780 --> 00:08:45,299 you take you take a pot, 220 00:08:45,300 --> 00:08:47,479 pour in some water, put it on the oven, 221 00:08:47,480 --> 00:08:49,559 on the cook and the cooker, 222 00:08:49,560 --> 00:08:51,639 heat it up and hold in your hand and 223 00:08:51,640 --> 00:08:53,759 a thermometer and see when when 224 00:08:53,760 --> 00:08:56,099 the pain starts to become unbearable. 225 00:08:56,100 --> 00:08:57,879 So 60 degrees. 226 00:08:57,880 --> 00:09:00,479 So the question was at which temperature? 227 00:09:00,480 --> 00:09:01,480 Yeah. 228 00:09:02,450 --> 00:09:04,499 Anyway, so this is painful. 229 00:09:04,500 --> 00:09:05,520 I don't want to do it. 230 00:09:08,460 --> 00:09:10,919 I want to show you no 231 00:09:10,920 --> 00:09:11,920 harm. 232 00:09:14,430 --> 00:09:16,529 I talked about the 233 00:09:16,530 --> 00:09:19,079 danger of the optical radiation 234 00:09:19,080 --> 00:09:21,659 we have we have two more two more 235 00:09:21,660 --> 00:09:24,269 dangerous sources of danger. 236 00:09:24,270 --> 00:09:26,399 One is when you 237 00:09:26,400 --> 00:09:28,559 handle a gas laser 238 00:09:28,560 --> 00:09:30,629 like a CO2 tube or 239 00:09:30,630 --> 00:09:33,089 different different gas mixtures, 240 00:09:33,090 --> 00:09:35,219 you need to have a high voltage. 241 00:09:35,220 --> 00:09:37,439 The laser at the lab 242 00:09:37,440 --> 00:09:39,689 wants to have 5000 volts 243 00:09:39,690 --> 00:09:42,869 and we give them 30 millions. 244 00:09:42,870 --> 00:09:43,870 This is deadly. 245 00:09:44,860 --> 00:09:46,929 Simple. This is deadly, you touch it, you 246 00:09:46,930 --> 00:09:48,789 die mostly. 247 00:09:48,790 --> 00:09:49,870 The other thing is 248 00:09:51,190 --> 00:09:53,289 what happens when you 249 00:09:53,290 --> 00:09:55,689 apply a lot of energy, thermal 250 00:09:55,690 --> 00:09:58,059 energy, onto whatever material 251 00:09:58,060 --> 00:09:59,919 it evaporate. 252 00:09:59,920 --> 00:10:02,950 And sometimes 253 00:10:04,070 --> 00:10:06,279 the molecules, the burning 254 00:10:06,280 --> 00:10:08,049 of the molecules break. 255 00:10:08,050 --> 00:10:09,549 And then you have quite some funny 256 00:10:09,550 --> 00:10:10,609 things. 257 00:10:10,610 --> 00:10:12,879 I made a video with the with my laser 258 00:10:12,880 --> 00:10:13,880 at work. 259 00:10:15,040 --> 00:10:18,309 This is thousand sixty four nanometers 260 00:10:18,310 --> 00:10:20,409 on a special cardboard, which is 261 00:10:20,410 --> 00:10:22,779 painted with a lack to 262 00:10:22,780 --> 00:10:25,299 to see if the geometry 263 00:10:25,300 --> 00:10:27,159 is right, if the policies are right and 264 00:10:27,160 --> 00:10:28,149 so on. 265 00:10:28,150 --> 00:10:30,249 But what you see as well, I switched 266 00:10:30,250 --> 00:10:32,289 off the the fume extraction system, which 267 00:10:32,290 --> 00:10:34,239 you can see at the right hand side, the 268 00:10:34,240 --> 00:10:35,240 hose, 269 00:10:36,430 --> 00:10:37,319 the smoke. 270 00:10:37,320 --> 00:10:39,189 That's coming up. 271 00:10:39,190 --> 00:10:40,190 This smells bad. 272 00:10:41,170 --> 00:10:43,419 And when you do, 273 00:10:43,420 --> 00:10:46,119 let's say, five to ten markings 274 00:10:46,120 --> 00:10:48,309 on this cardboard, you feel a bad 275 00:10:48,310 --> 00:10:49,990 feeling in your tummy. 276 00:10:53,290 --> 00:10:54,290 Now, 277 00:10:55,570 --> 00:10:57,369 imagine you have some other materials. 278 00:10:57,370 --> 00:10:59,589 You have plastics, which is 279 00:10:59,590 --> 00:11:01,659 a mixture of different different 280 00:11:01,660 --> 00:11:03,939 elements and molecules, and they break 281 00:11:03,940 --> 00:11:06,009 up and suddenly you have 282 00:11:06,010 --> 00:11:08,380 some some delicious things like 283 00:11:09,730 --> 00:11:12,070 cyanide, foreigns, dioxin, 284 00:11:13,840 --> 00:11:17,109 chlorine, formaldehyde. 285 00:11:17,110 --> 00:11:18,039 Not funny. 286 00:11:18,040 --> 00:11:19,389 So I don't want to smell this. 287 00:11:19,390 --> 00:11:21,219 I don't want to have this in my system. 288 00:11:21,220 --> 00:11:23,979 Azfar When you do do metal marking, 289 00:11:23,980 --> 00:11:26,679 you need to have a fume extraction 290 00:11:26,680 --> 00:11:28,929 when when you mark on stainless 291 00:11:28,930 --> 00:11:29,859 steel for example. 292 00:11:29,860 --> 00:11:31,959 So it's not just iron, it's 293 00:11:31,960 --> 00:11:34,179 other metals as well, and 294 00:11:34,180 --> 00:11:36,519 it's in a lot of different metals. 295 00:11:36,520 --> 00:11:38,679 So it splits into 296 00:11:38,680 --> 00:11:41,199 the elements like nickel, chromium, 297 00:11:41,200 --> 00:11:43,779 Mongan, cobalt, niobium, 298 00:11:43,780 --> 00:11:46,009 beryllium, LED's and so 299 00:11:46,010 --> 00:11:48,069 and when you take ceramics you have the 300 00:11:48,070 --> 00:11:50,630 same yummy delicious contant. 301 00:11:52,090 --> 00:11:54,339 A fume extraction system is very, 302 00:11:54,340 --> 00:11:56,169 very important, very vital. 303 00:11:56,170 --> 00:11:58,529 If you do something in the 304 00:11:58,530 --> 00:12:00,819 in the region of material 305 00:12:00,820 --> 00:12:02,409 marking when you want to change the 306 00:12:02,410 --> 00:12:04,449 material. So if you just have a laser 307 00:12:04,450 --> 00:12:06,939 pointer and you change your cat. 308 00:12:06,940 --> 00:12:09,789 So this this doesn't apply. 309 00:12:09,790 --> 00:12:11,679 This is only if you do something with the 310 00:12:11,680 --> 00:12:12,680 material. 311 00:12:16,180 --> 00:12:18,309 So this mentioned standard 312 00:12:18,310 --> 00:12:19,979 end 150, 313 00:12:21,060 --> 00:12:22,989 11, five fafi. 314 00:12:22,990 --> 00:12:26,379 This is our come to standards later. 315 00:12:26,380 --> 00:12:28,479 This is a first introduction 316 00:12:28,480 --> 00:12:29,770 into the standard. 317 00:12:32,160 --> 00:12:34,259 A lot of things around lasers are 318 00:12:34,260 --> 00:12:35,399 standardized 319 00:12:36,630 --> 00:12:38,699 wavelength to 320 00:12:38,700 --> 00:12:40,949 to energy and which 321 00:12:40,950 --> 00:12:43,189 class it gives and so on, 322 00:12:43,190 --> 00:12:44,190 I think 323 00:12:45,570 --> 00:12:47,959 protective material has to be how the 324 00:12:47,960 --> 00:12:50,039 the glasses have to be 325 00:12:50,040 --> 00:12:52,199 to be made, of which 326 00:12:52,200 --> 00:12:54,059 answer quite a lot. 327 00:12:54,060 --> 00:12:55,370 I would come to this later. 328 00:12:57,240 --> 00:12:59,939 I'm going to talk about laser classes 329 00:12:59,940 --> 00:13:00,940 now. 330 00:13:02,100 --> 00:13:04,089 Shut down. 331 00:13:04,090 --> 00:13:05,519 Not yet. 332 00:13:05,520 --> 00:13:07,739 Some funny things you shouldn't do 333 00:13:07,740 --> 00:13:10,049 on the top left side, top 334 00:13:10,050 --> 00:13:11,999 left image. This was last year in the 335 00:13:12,000 --> 00:13:13,169 hack center. 336 00:13:13,170 --> 00:13:14,879 I want to apologize to the to the 337 00:13:14,880 --> 00:13:16,799 taxpayers, to the Stuttgart hackers, 338 00:13:16,800 --> 00:13:19,139 because we projected some some 339 00:13:19,140 --> 00:13:21,659 images at the wall 340 00:13:21,660 --> 00:13:23,839 above them. And I was a bit 341 00:13:23,840 --> 00:13:24,840 too old. 342 00:13:25,620 --> 00:13:27,479 Is it OK? 343 00:13:27,480 --> 00:13:29,819 OK, so 344 00:13:29,820 --> 00:13:30,820 I'm sorry for that. 345 00:13:31,860 --> 00:13:34,049 What do you see as a 400, 500 346 00:13:34,050 --> 00:13:36,179 million light blue laser 347 00:13:36,180 --> 00:13:38,699 standing on the on the MTC DVD 348 00:13:38,700 --> 00:13:39,700 box 349 00:13:41,100 --> 00:13:43,289 on a on a bestrode table which 350 00:13:43,290 --> 00:13:44,879 was standing on the normal table. 351 00:13:44,880 --> 00:13:47,219 So it was about this height and 352 00:13:47,220 --> 00:13:49,529 then we had to power supply and 353 00:13:49,530 --> 00:13:52,019 then we had to galvanometer control 354 00:13:52,020 --> 00:13:54,329 and so we could deflect 355 00:13:54,330 --> 00:13:55,330 the beam. 356 00:13:56,190 --> 00:13:58,409 So if someone pushes it just 357 00:13:58,410 --> 00:14:00,719 a bit and everything gets misalliance 358 00:14:00,720 --> 00:14:02,879 and someone walks by or doesn't realize 359 00:14:02,880 --> 00:14:05,069 it has a blue license. 360 00:14:05,070 --> 00:14:07,259 So remember, the first first 361 00:14:07,260 --> 00:14:09,239 images of the eyes gives a nice black 362 00:14:09,240 --> 00:14:10,240 spot. 363 00:14:12,180 --> 00:14:14,519 The image below I found in a book 364 00:14:15,750 --> 00:14:17,909 playing with lasers 365 00:14:17,910 --> 00:14:20,369 that was in the library and collecting my 366 00:14:20,370 --> 00:14:22,709 materials. And I came across this image 367 00:14:22,710 --> 00:14:23,999 as no way. 368 00:14:25,440 --> 00:14:26,849 The subtitle was 369 00:14:28,170 --> 00:14:30,869 Please Don't Look on two reflecting 370 00:14:30,870 --> 00:14:31,870 materials. 371 00:14:36,910 --> 00:14:39,039 In a book you could buy 372 00:14:39,040 --> 00:14:42,009 officially for the move 373 00:14:42,010 --> 00:14:44,649 to tinker with lasers, 374 00:14:44,650 --> 00:14:46,659 and this is one of the most stupid ideas 375 00:14:46,660 --> 00:14:48,519 and I will tell you later why this is one 376 00:14:48,520 --> 00:14:50,439 of the most stupid idea it has to do with 377 00:14:50,440 --> 00:14:51,460 laser classes 378 00:14:53,080 --> 00:14:55,149 and what you see on on the 379 00:14:55,150 --> 00:14:56,739 other side, on the right hand side. 380 00:14:57,880 --> 00:14:59,330 I want to go to vacations. 381 00:15:02,530 --> 00:15:03,429 Excuse me. 382 00:15:03,430 --> 00:15:04,839 I wanted to go to vacations. 383 00:15:04,840 --> 00:15:07,329 And I had quite a lot of work to do, 384 00:15:07,330 --> 00:15:09,609 programing FPGA on my laser 385 00:15:09,610 --> 00:15:11,139 system. So this is the Internet of 386 00:15:11,140 --> 00:15:13,330 Malaysia system and this is at home 387 00:15:15,460 --> 00:15:17,949 because I'm a profaned profit, 388 00:15:17,950 --> 00:15:20,499 professional, trained laser person. 389 00:15:21,910 --> 00:15:23,679 I thought, well, I have my safety 390 00:15:23,680 --> 00:15:26,079 goggles. I try to cut away, 391 00:15:26,080 --> 00:15:28,149 close the window blinds, 392 00:15:28,150 --> 00:15:29,949 and I did my programing work. 393 00:15:29,950 --> 00:15:31,449 And every now and then I had to switch on 394 00:15:31,450 --> 00:15:33,429 the laser and to see if everything goes 395 00:15:33,430 --> 00:15:34,430 well. 396 00:15:36,190 --> 00:15:37,190 So. 397 00:15:38,810 --> 00:15:40,969 The lies ahead, this is a gray box 398 00:15:40,970 --> 00:15:41,970 on top 399 00:15:43,100 --> 00:15:45,259 there, the laser beam goes in 400 00:15:45,260 --> 00:15:47,299 there to governor meters with mirrors, 401 00:15:47,300 --> 00:15:49,549 and then it goes through a lens onto 402 00:15:49,550 --> 00:15:51,619 the material things where the 403 00:15:51,620 --> 00:15:52,909 magic happens. 404 00:15:52,910 --> 00:15:55,099 And this this 405 00:15:55,100 --> 00:15:57,679 brown thingy is a loudspeaker. 406 00:16:01,400 --> 00:16:03,859 And what's round it round 407 00:16:03,860 --> 00:16:06,469 is a five hour reinforced 408 00:16:06,470 --> 00:16:07,470 tape 409 00:16:10,790 --> 00:16:12,919 on the on the right hand side you see in 410 00:16:12,920 --> 00:16:14,929 oscilloscope, I do not say which brand, 411 00:16:14,930 --> 00:16:15,930 but it's crap. 412 00:16:18,940 --> 00:16:21,789 Now, it makes it fun and 413 00:16:21,790 --> 00:16:24,249 what you see in front 414 00:16:24,250 --> 00:16:26,319 is the big box there 415 00:16:26,320 --> 00:16:28,749 that happens, magic, electricity 416 00:16:28,750 --> 00:16:31,029 and light out and 417 00:16:31,030 --> 00:16:33,009 the rest is controlled electronics. 418 00:16:33,010 --> 00:16:35,079 So I had to to do some work at 419 00:16:35,080 --> 00:16:36,130 home. And 420 00:16:37,810 --> 00:16:39,039 if you don't know what you're doing, so 421 00:16:39,040 --> 00:16:40,809 don't do it, please. 422 00:16:40,810 --> 00:16:43,299 If you know exactly what you do, maybe 423 00:16:43,300 --> 00:16:44,589 you can do it. 424 00:16:44,590 --> 00:16:46,689 Talk to other guys and maybe 425 00:16:46,690 --> 00:16:48,759 you better stay alone in that 426 00:16:48,760 --> 00:16:49,760 room, 427 00:16:50,830 --> 00:16:52,899 not to to harm anyone 428 00:16:52,900 --> 00:16:54,249 else. 429 00:16:54,250 --> 00:16:55,250 Um. 430 00:16:57,430 --> 00:16:59,350 Right are classes, 431 00:17:01,240 --> 00:17:04,539 basically, they are 432 00:17:04,540 --> 00:17:06,639 less leisure classes, which are 433 00:17:06,640 --> 00:17:07,779 interesting for you. 434 00:17:09,490 --> 00:17:11,709 We have Felice's classes, you can see, 435 00:17:11,710 --> 00:17:13,989 but for you as hackers, 436 00:17:13,990 --> 00:17:16,149 I think there are two Thalia's 437 00:17:16,150 --> 00:17:17,379 of classes. Interesting. 438 00:17:17,380 --> 00:17:18,700 One is laser class one. 439 00:17:20,079 --> 00:17:22,299 I don't know what the old school 440 00:17:22,300 --> 00:17:24,489 audio CD players have us as 441 00:17:24,490 --> 00:17:26,799 a class, but laser class one is 442 00:17:26,800 --> 00:17:28,929 you take your laser pointer and stare 443 00:17:28,930 --> 00:17:31,089 into it. And when you're bored after half 444 00:17:31,090 --> 00:17:32,319 an hour, you're switched off and nothing 445 00:17:32,320 --> 00:17:33,320 happens. 446 00:17:33,850 --> 00:17:36,429 This laser class one is interesting for 447 00:17:36,430 --> 00:17:38,319 four high powered lasers as well. 448 00:17:38,320 --> 00:17:39,320 I come to it later. 449 00:17:40,780 --> 00:17:41,780 Class two 450 00:17:43,150 --> 00:17:44,589 is what you have, 451 00:17:45,640 --> 00:17:46,640 what you see here, 452 00:17:48,310 --> 00:17:50,409 what you try the laser, you try to 453 00:17:50,410 --> 00:17:51,410 cut 454 00:17:55,210 --> 00:17:56,679 it. 455 00:17:56,680 --> 00:17:58,749 It comes with something 456 00:17:58,750 --> 00:18:01,179 that we call the ILIT reflect 457 00:18:01,180 --> 00:18:03,219 eyelid closing reflex. 458 00:18:03,220 --> 00:18:05,439 So the theory is that 459 00:18:06,700 --> 00:18:08,829 when you get hit by this class 460 00:18:08,830 --> 00:18:11,049 two laser beam, you I 461 00:18:11,050 --> 00:18:13,299 will close fast enough 462 00:18:13,300 --> 00:18:14,819 to avoid any damage. 463 00:18:16,180 --> 00:18:18,459 And that's a weak point 464 00:18:18,460 --> 00:18:19,689 of this theory. 465 00:18:19,690 --> 00:18:22,329 That was a big examination, 466 00:18:22,330 --> 00:18:24,609 a big test that had thousands 467 00:18:24,610 --> 00:18:27,069 have 100 pupils and 468 00:18:27,070 --> 00:18:29,410 they were sitting on it on a chair and 469 00:18:30,470 --> 00:18:32,529 the face was monitored with a high speed 470 00:18:32,530 --> 00:18:34,329 camera. And there was a line, a laser 471 00:18:34,330 --> 00:18:35,949 light and coming down. 472 00:18:35,950 --> 00:18:38,499 And they measured the time between 473 00:18:38,500 --> 00:18:40,899 laser hitting the eye, coming 474 00:18:40,900 --> 00:18:42,939 onto the retina so you could see the 475 00:18:42,940 --> 00:18:43,989 laser beam. 476 00:18:43,990 --> 00:18:46,299 And to look 477 00:18:46,300 --> 00:18:48,999 away, you close your eyes, whatever. 478 00:18:49,000 --> 00:18:51,149 And only 20 percent 479 00:18:51,150 --> 00:18:53,589 of the people 480 00:18:53,590 --> 00:18:56,079 close their eyes within these 250 481 00:18:56,080 --> 00:18:58,779 milliseconds, which they're 482 00:18:58,780 --> 00:19:00,369 the eye. 483 00:19:00,370 --> 00:19:02,319 The closing reflects talks about. 484 00:19:03,670 --> 00:19:06,219 So 80 percent don't be 485 00:19:06,220 --> 00:19:07,659 are not in time. 486 00:19:07,660 --> 00:19:09,989 So there were people even 487 00:19:09,990 --> 00:19:12,339 who needed one second to realize, 488 00:19:12,340 --> 00:19:14,679 oh, laser beam closing light 489 00:19:14,680 --> 00:19:16,479 or looking away. 490 00:19:16,480 --> 00:19:17,979 And in that time there can be some 491 00:19:17,980 --> 00:19:18,999 damage. 492 00:19:19,000 --> 00:19:21,219 So even this 493 00:19:21,220 --> 00:19:23,289 crap here, this 494 00:19:23,290 --> 00:19:25,959 pointer is not safe 495 00:19:25,960 --> 00:19:27,669 for the eye, even if you can buy it 496 00:19:27,670 --> 00:19:30,009 everywhere in Photoshop or 497 00:19:30,010 --> 00:19:31,479 at a supermarket whatsoever. 498 00:19:32,980 --> 00:19:35,139 Be careful then 499 00:19:35,140 --> 00:19:37,329 we have a 500 00:19:37,330 --> 00:19:38,349 class for you. 501 00:19:38,350 --> 00:19:40,569 So there is a difference that 502 00:19:40,570 --> 00:19:42,789 the class is one and to the 503 00:19:42,790 --> 00:19:44,979 have the Mazwai and one 504 00:19:44,980 --> 00:19:47,109 is you can stand to it with 505 00:19:47,110 --> 00:19:49,239 a magnifying glass and 506 00:19:49,240 --> 00:19:50,619 everything's safe. 507 00:19:50,620 --> 00:19:52,719 And the other one is you can't use 508 00:19:52,720 --> 00:19:55,429 any optical instruments. 509 00:19:55,430 --> 00:19:57,289 To be safe in that class, 510 00:19:58,430 --> 00:19:59,430 um, 511 00:20:00,740 --> 00:20:03,229 class three is, 512 00:20:03,230 --> 00:20:06,079 yeah, it's a bit less dangerous 513 00:20:07,160 --> 00:20:10,039 than class for it is 514 00:20:10,040 --> 00:20:11,040 there talk about 515 00:20:13,040 --> 00:20:15,289 five times more energetic than 516 00:20:15,290 --> 00:20:16,290 than class two. 517 00:20:17,930 --> 00:20:20,509 What's really funny is class for 518 00:20:20,510 --> 00:20:22,819 everything from 500 million amps to 519 00:20:22,820 --> 00:20:24,799 megawatt gigawatt. 520 00:20:24,800 --> 00:20:26,989 So this is 521 00:20:26,990 --> 00:20:29,419 you this is a class you you shouldn't 522 00:20:29,420 --> 00:20:31,519 have opened like 523 00:20:31,520 --> 00:20:33,230 it did on my desk, 524 00:20:34,580 --> 00:20:36,719 but you can make it safe. 525 00:20:36,720 --> 00:20:38,809 You can have this gigantic 526 00:20:38,810 --> 00:20:41,089 house fire, which you have in a fusion 527 00:20:41,090 --> 00:20:43,219 reactor as a class one 528 00:20:43,220 --> 00:20:46,159 laser. You just encapsulated 529 00:20:46,160 --> 00:20:48,049 that. Make sure that no laser beam goes 530 00:20:48,050 --> 00:20:50,139 out. Then you have a laser class one 531 00:20:50,140 --> 00:20:51,140 system. 532 00:20:51,920 --> 00:20:53,989 So the 533 00:20:53,990 --> 00:20:55,099 class is as well. 534 00:20:57,740 --> 00:20:59,660 This is according to the wavelength 535 00:21:01,160 --> 00:21:03,589 there we have the vision, the visible 536 00:21:03,590 --> 00:21:05,660 system of the visible wavelength. 537 00:21:06,830 --> 00:21:08,899 And you can see it goes up 538 00:21:08,900 --> 00:21:10,969 on the right hand side of where 539 00:21:10,970 --> 00:21:12,499 you can see that you have a higher 540 00:21:12,500 --> 00:21:14,689 region, which is have within this 541 00:21:14,690 --> 00:21:17,929 laser class. This is region of the ISAF 542 00:21:17,930 --> 00:21:21,259 region, which is about a thousand 543 00:21:21,260 --> 00:21:22,819 five hundred thousand eight hundred 544 00:21:22,820 --> 00:21:24,929 nanometers, something I forgot the number 545 00:21:24,930 --> 00:21:25,930 now. 546 00:21:30,060 --> 00:21:32,879 We have also a different 547 00:21:32,880 --> 00:21:35,819 different damages 548 00:21:35,820 --> 00:21:37,949 on the skin in the eye, according 549 00:21:37,950 --> 00:21:40,049 to the wavelengths, you've 550 00:21:40,050 --> 00:21:42,239 you know, you are the sun for 551 00:21:42,240 --> 00:21:44,579 too long. Are you you you like 552 00:21:44,580 --> 00:21:46,959 your your tanning studio too much. 553 00:21:46,960 --> 00:21:48,719 You get burns on on your skin. 554 00:21:48,720 --> 00:21:51,149 And when you have a UV lamps, you have 555 00:21:51,150 --> 00:21:53,789 your glasses, your goggles. 556 00:21:53,790 --> 00:21:56,149 So you have different types of comic 557 00:21:56,150 --> 00:21:58,349 photochemical reactions of reactions 558 00:21:58,350 --> 00:22:00,539 of the skin, especially with 559 00:22:00,540 --> 00:22:03,239 the eyes of the UVA. 560 00:22:03,240 --> 00:22:06,539 You have damage of the cornea 561 00:22:06,540 --> 00:22:09,179 and the longer the wavelength 562 00:22:09,180 --> 00:22:11,249 than you have in your movie, you have 563 00:22:11,250 --> 00:22:12,810 the damage of the lens 564 00:22:14,220 --> 00:22:16,349 and then you have a damage of the retina. 565 00:22:16,350 --> 00:22:18,929 And the longer the wavelength goes, 566 00:22:18,930 --> 00:22:21,029 it goes back to to to 567 00:22:21,030 --> 00:22:22,679 damaging the cornea. 568 00:22:22,680 --> 00:22:24,720 So when the cornea is damaged, it's 569 00:22:26,520 --> 00:22:28,649 stupid, it's bad. 570 00:22:28,650 --> 00:22:30,929 But you can you might fix 571 00:22:30,930 --> 00:22:33,209 might be able to fix it or a doctor might 572 00:22:33,210 --> 00:22:34,769 or you can have a new lens. 573 00:22:34,770 --> 00:22:36,869 But this is nothing you want to have 574 00:22:36,870 --> 00:22:37,870 seriously. 575 00:22:42,330 --> 00:22:45,749 So standards 576 00:22:45,750 --> 00:22:47,579 are very important. 577 00:22:47,580 --> 00:22:49,199 You can do at home, you can do whatever 578 00:22:49,200 --> 00:22:51,629 you want by you have 50 579 00:22:51,630 --> 00:22:54,629 watts 100 watt CO2 tube at 580 00:22:54,630 --> 00:22:55,679 the Chinese vape shop. 581 00:22:55,680 --> 00:22:57,359 They are cheap. 582 00:22:57,360 --> 00:22:59,519 You lock your doors, you do what you 583 00:22:59,520 --> 00:23:00,449 want. 584 00:23:00,450 --> 00:23:02,639 If no one else is in the room, 585 00:23:02,640 --> 00:23:04,769 as soon as other people are involved, you 586 00:23:04,770 --> 00:23:06,929 should read the standards 587 00:23:06,930 --> 00:23:07,950 which say. 588 00:23:09,090 --> 00:23:11,519 For example, the 589 00:23:11,520 --> 00:23:14,649 the end 60 825, 590 00:23:14,650 --> 00:23:15,650 a 591 00:23:16,890 --> 00:23:19,829 number one, part one has 592 00:23:19,830 --> 00:23:22,169 the safety things about about a laser 593 00:23:22,170 --> 00:23:23,579 system. 594 00:23:23,580 --> 00:23:25,469 You have to have a proper housing. 595 00:23:25,470 --> 00:23:27,629 You have to to to monitor 596 00:23:27,630 --> 00:23:29,159 any any openings. 597 00:23:29,160 --> 00:23:31,259 And when when you open something, the 598 00:23:31,260 --> 00:23:32,459 beam has to be interrupted. 599 00:23:32,460 --> 00:23:34,769 And so and you need to have from class 600 00:23:34,770 --> 00:23:37,139 laser class thie, you need to have a key 601 00:23:37,140 --> 00:23:39,509 switch for access control or magnetic 602 00:23:39,510 --> 00:23:41,579 card or whatever RFID 603 00:23:41,580 --> 00:23:43,649 system and the lab you want to 604 00:23:43,650 --> 00:23:45,749 to set up an RFID system 605 00:23:45,750 --> 00:23:47,009 for the dangerous machines. 606 00:23:48,270 --> 00:23:50,339 So this would would 607 00:23:50,340 --> 00:23:52,260 satisfy this standard. 608 00:23:56,080 --> 00:23:58,299 I could talk one week about these 609 00:23:58,300 --> 00:23:59,439 standards. 610 00:23:59,440 --> 00:24:01,779 They're very complex, they're very 611 00:24:01,780 --> 00:24:03,219 worth to read. 612 00:24:03,220 --> 00:24:05,799 You can you can read them. 613 00:24:05,800 --> 00:24:07,419 You can't, as far as I know, you can't 614 00:24:07,420 --> 00:24:09,729 copy them at the universities, which 615 00:24:09,730 --> 00:24:12,229 have a technical department. 616 00:24:12,230 --> 00:24:14,319 So as you go there, you you ask for the 617 00:24:14,320 --> 00:24:16,089 standards. You ask in Germany, you ask 618 00:24:16,090 --> 00:24:18,219 for any whatsoever. 619 00:24:18,220 --> 00:24:20,349 And the British, you ask for a B 620 00:24:20,350 --> 00:24:23,109 as any whatsoever and 621 00:24:23,110 --> 00:24:24,110 you can read them. 622 00:24:25,310 --> 00:24:26,310 And some. 623 00:24:27,940 --> 00:24:28,940 Well, 624 00:24:31,090 --> 00:24:32,979 it makes no sense to go through the 625 00:24:32,980 --> 00:24:33,980 standards. 626 00:24:34,510 --> 00:24:37,119 We can talk about it later on the accent, 627 00:24:37,120 --> 00:24:38,120 if you like. 628 00:24:39,710 --> 00:24:42,079 If you design a system, 629 00:24:42,080 --> 00:24:44,559 there are some things you should 630 00:24:44,560 --> 00:24:45,939 you should look at. 631 00:24:47,200 --> 00:24:49,449 He should monitor every opening, 632 00:24:49,450 --> 00:24:50,450 every door. 633 00:24:51,730 --> 00:24:54,339 He should have an emergency system. 634 00:24:54,340 --> 00:24:56,919 It is a must have seriously. 635 00:24:56,920 --> 00:24:59,139 And you need to decide if you 636 00:24:59,140 --> 00:25:01,299 want to have an emergency shutoff or 637 00:25:01,300 --> 00:25:03,729 emergency stop that 638 00:25:03,730 --> 00:25:05,980 different ideas behind 639 00:25:07,360 --> 00:25:09,009 it. You need to have a shutter which 640 00:25:09,010 --> 00:25:10,010 interrupts a beam. 641 00:25:10,900 --> 00:25:13,269 You need to have some 642 00:25:13,270 --> 00:25:14,270 excess control. 643 00:25:15,490 --> 00:25:17,169 You need very important, as we saw 644 00:25:17,170 --> 00:25:18,789 before, you need to have a few extraction 645 00:25:18,790 --> 00:25:20,979 system you don't want to have in your 646 00:25:20,980 --> 00:25:23,409 space or the chromium and 647 00:25:23,410 --> 00:25:25,299 burnt wood smell. 648 00:25:25,300 --> 00:25:27,369 I mean, if we before we 649 00:25:27,370 --> 00:25:29,529 had a filter system in the lab, when 650 00:25:29,530 --> 00:25:31,899 we cut wood, you 651 00:25:31,900 --> 00:25:33,939 could smell it hundreds of meters away, 652 00:25:33,940 --> 00:25:35,919 half a kilometer you could smell, oh, in 653 00:25:35,920 --> 00:25:37,029 the lab they are burning what 654 00:25:39,310 --> 00:25:41,949 you need to do a risk analysis. 655 00:25:41,950 --> 00:25:43,690 What happens if something goes wrong? 656 00:25:44,710 --> 00:25:46,929 What happens if the laser 657 00:25:46,930 --> 00:25:48,999 source doesn't respond on, please 658 00:25:49,000 --> 00:25:51,249 shut off and 659 00:25:51,250 --> 00:25:53,439 this and that. It's a long 660 00:25:53,440 --> 00:25:54,730 process of thinking. 661 00:25:57,820 --> 00:25:59,259 It has to be taken seriously. 662 00:25:59,260 --> 00:26:00,849 There is literature. You should take it 663 00:26:00,850 --> 00:26:01,850 seriously. 664 00:26:03,400 --> 00:26:05,769 You should document your project. 665 00:26:05,770 --> 00:26:07,989 And unfortunately, there is someone 666 00:26:07,990 --> 00:26:10,209 who has to sign for 667 00:26:10,210 --> 00:26:13,209 what you do, who is reliable, 668 00:26:13,210 --> 00:26:14,210 liable for this, 669 00:26:16,150 --> 00:26:18,339 finally, who can 670 00:26:18,340 --> 00:26:20,409 operate, I think, 671 00:26:20,410 --> 00:26:22,779 on hackerspace, who is allowed to operate 672 00:26:22,780 --> 00:26:24,189 the laser. 673 00:26:24,190 --> 00:26:27,279 So we will have a few 674 00:26:27,280 --> 00:26:28,280 short minutes. 675 00:26:29,260 --> 00:26:30,879 You will find me if you want to have 676 00:26:30,880 --> 00:26:31,719 some. 677 00:26:31,720 --> 00:26:33,849 Some if you have some questions, 678 00:26:33,850 --> 00:26:35,289 if it can help you with your laser 679 00:26:35,290 --> 00:26:36,729 design. I'm here. 680 00:26:36,730 --> 00:26:37,900 I'm at the center 681 00:26:39,700 --> 00:26:42,189 at the fire overflow. 682 00:26:42,190 --> 00:26:44,439 It's you come in the center very far 683 00:26:44,440 --> 00:26:47,229 at the right furthermost 684 00:26:47,230 --> 00:26:48,230 corner. 685 00:26:49,270 --> 00:26:51,999 If you have questions, then 686 00:26:52,000 --> 00:26:54,399 we can discuss your your issues 687 00:26:54,400 --> 00:26:55,719 with lasers. 688 00:26:55,720 --> 00:26:58,809 No problem. I'm delighted to do so. 689 00:26:58,810 --> 00:27:01,749 Otherwise, please wear safety goggles. 690 00:27:01,750 --> 00:27:03,939 And if you have any 691 00:27:03,940 --> 00:27:06,099 questions, we have how many 692 00:27:06,100 --> 00:27:09,069 minutes we are done. 693 00:27:09,070 --> 00:27:10,599 I'm sorry. 694 00:27:10,600 --> 00:27:12,489 Accent Thank you very much.