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If you are capable, please help us to create good quality subtitles: https://c3subtitles.de/talk/445 Thanks! 1 00:00:10,180 --> 00:00:12,309 First of all, thank 2 00:00:12,310 --> 00:00:13,839 you for coming. 3 00:00:13,840 --> 00:00:16,058 I will be honest with you, I wouldn't 4 00:00:16,059 --> 00:00:18,219 have been surprised at least 5 00:00:18,220 --> 00:00:20,180 if the room would be empty. 6 00:00:21,280 --> 00:00:23,049 I mean, its security nightmares. 7 00:00:23,050 --> 00:00:24,939 I mean, we're talking about one of the 8 00:00:24,940 --> 00:00:25,989 two major events. 9 00:00:27,040 --> 00:00:29,799 And I'm really, really flattered 10 00:00:29,800 --> 00:00:31,179 by the attention. 11 00:00:31,180 --> 00:00:33,399 So I 12 00:00:33,400 --> 00:00:36,369 see we do have an issue there 13 00:00:36,370 --> 00:00:37,370 cause. 14 00:00:38,290 --> 00:00:39,290 No. 15 00:00:41,810 --> 00:00:44,749 Um, from 16 00:00:44,750 --> 00:00:46,789 that screen number eight, 17 00:00:48,440 --> 00:00:51,019 uh, sorry, 18 00:00:51,020 --> 00:00:53,209 you know how HowStuffWorks don't 19 00:00:53,210 --> 00:00:54,709 don't you? 20 00:00:54,710 --> 00:00:57,189 And of course, I 21 00:00:57,190 --> 00:00:59,839 I'm in the wrong folder, so 22 00:00:59,840 --> 00:01:01,589 you will see me doing some come on line 23 00:01:01,590 --> 00:01:03,210 for, um. 24 00:01:05,630 --> 00:01:06,630 Oh, come on. 25 00:01:09,100 --> 00:01:11,719 Um, two months, three 26 00:01:13,100 --> 00:01:14,300 presentation. 27 00:01:15,530 --> 00:01:18,049 So this is the main part 28 00:01:18,050 --> 00:01:19,849 where I explain to you how you start the 29 00:01:19,850 --> 00:01:21,230 presentation of the command line. 30 00:01:22,880 --> 00:01:25,519 And here we are and 31 00:01:25,520 --> 00:01:27,309 this thing scray, 32 00:01:28,790 --> 00:01:31,369 I think we do have to 33 00:01:31,370 --> 00:01:33,559 solve the problem here. 34 00:01:33,560 --> 00:01:35,569 I do have to 35 00:01:37,670 --> 00:01:38,670 I'm sorry. 36 00:01:39,330 --> 00:01:40,330 Um, 37 00:01:42,200 --> 00:01:43,200 OK. 38 00:01:43,910 --> 00:01:46,099 That's how things work 39 00:01:47,900 --> 00:01:50,159 baboon's to three 40 00:01:51,920 --> 00:01:53,029 presentation. 41 00:01:55,220 --> 00:01:57,559 So, yeah, as you have imagined, 42 00:01:57,560 --> 00:01:58,730 it's about 43 00:02:00,140 --> 00:02:02,629 um making 44 00:02:02,630 --> 00:02:02,959 your own. 45 00:02:02,960 --> 00:02:04,699 Tell us. I will talk. 46 00:02:04,700 --> 00:02:07,039 I will brabo along because 47 00:02:07,040 --> 00:02:08,599 I'm here. 48 00:02:08,600 --> 00:02:09,710 That, that's kind of. 49 00:02:11,570 --> 00:02:12,570 Yeah. 50 00:02:18,370 --> 00:02:20,569 Do you know, um, I'm 51 00:02:20,570 --> 00:02:22,789 sorry, I just screwed up 52 00:02:22,790 --> 00:02:24,259 totally, um, 53 00:02:25,730 --> 00:02:27,709 you know, don't worry about it. 54 00:02:27,710 --> 00:02:29,179 I think you're not right. 55 00:02:29,180 --> 00:02:30,229 Yeah, I don't think so either. 56 00:02:31,270 --> 00:02:34,299 So he told me not to worry about it. 57 00:02:34,300 --> 00:02:36,579 I mean, I don't want 58 00:02:36,580 --> 00:02:38,859 to be to be honest, I don't have 59 00:02:38,860 --> 00:02:40,419 to worry about it because you don't 60 00:02:40,420 --> 00:02:41,420 really screwed up. 61 00:02:42,630 --> 00:02:43,959 It's the last day of Congress. 62 00:02:43,960 --> 00:02:46,209 It's the last talk we had four 63 00:02:46,210 --> 00:02:49,299 days of not much sleep, probably. 64 00:02:49,300 --> 00:02:51,669 Oh, yeah. Tell me more about that. 65 00:02:51,670 --> 00:02:53,949 And we all had so we love tunnels 66 00:02:53,950 --> 00:02:56,049 and when to just look at them 67 00:02:56,050 --> 00:02:57,050 for a few minutes. 68 00:02:58,540 --> 00:02:59,889 So, yeah. 69 00:02:59,890 --> 00:03:02,619 Just appreciate the beauty of 70 00:03:02,620 --> 00:03:05,169 green fonts on black background. 71 00:03:10,950 --> 00:03:12,319 Oh, yes, yeah, 72 00:03:13,470 --> 00:03:14,539 oh, yeah, yeah, 73 00:03:17,550 --> 00:03:19,649 so if you want if you want to pwn 74 00:03:19,650 --> 00:03:21,329 if you want to put my laptop, if you do 75 00:03:21,330 --> 00:03:22,459 it, you're going to die. 76 00:03:22,460 --> 00:03:23,459 Yeah. 77 00:03:23,460 --> 00:03:26,109 And I'm not, I'm not especially the 78 00:03:26,110 --> 00:03:28,259 I'm just, I'm just saying I've 79 00:03:28,260 --> 00:03:30,509 only I've only seen that happen with 80 00:03:30,510 --> 00:03:31,619 Linux machines. 81 00:03:31,620 --> 00:03:31,869 Right. 82 00:03:31,870 --> 00:03:32,870 So 83 00:03:33,990 --> 00:03:36,599 it's not the 84 00:03:36,600 --> 00:03:38,729 same. And you asked 85 00:03:38,730 --> 00:03:40,829 me what I see happening 86 00:03:40,830 --> 00:03:42,989 on his monitor so uh so 87 00:03:42,990 --> 00:03:44,699 maybe we're close. 88 00:03:44,700 --> 00:03:45,700 Um. 89 00:03:54,590 --> 00:03:56,839 Let's set the duration to 45 90 00:03:56,840 --> 00:03:57,979 minutes, shall we? 91 00:03:57,980 --> 00:03:59,809 Yeah, and don't worry about it. 92 00:03:59,810 --> 00:04:00,779 Here we go. 93 00:04:00,780 --> 00:04:03,249 No y yeah. 94 00:04:04,280 --> 00:04:05,619 Huh. 95 00:04:05,620 --> 00:04:06,489 That's cool. 96 00:04:06,490 --> 00:04:07,489 No, I can't. 97 00:04:07,490 --> 00:04:08,490 It's it's, 98 00:04:12,090 --> 00:04:12,439 uh. 99 00:04:12,440 --> 00:04:14,149 Yeah, no, that's not the problem. 100 00:04:14,150 --> 00:04:15,829 The problem is that the other half is on 101 00:04:15,830 --> 00:04:17,869 his laptop monitor. 102 00:04:17,870 --> 00:04:20,059 OK, OK, so now, 103 00:04:20,060 --> 00:04:21,499 now we're going to do it, we're going to 104 00:04:21,500 --> 00:04:22,679 do it this way. 105 00:04:22,680 --> 00:04:25,459 So here, here we are, we 106 00:04:25,460 --> 00:04:27,679 know anything because this 107 00:04:27,680 --> 00:04:28,970 thing sucks 108 00:04:30,110 --> 00:04:31,110 so 109 00:04:33,310 --> 00:04:35,629 that I don't know, 110 00:04:35,630 --> 00:04:36,829 you probably have time. 111 00:04:36,830 --> 00:04:38,689 We are so so. 112 00:04:38,690 --> 00:04:41,329 All right. We've got something here and 113 00:04:41,330 --> 00:04:42,330 we'll have to go. 114 00:04:46,820 --> 00:04:49,069 That's that's that's always the thing, 115 00:04:49,070 --> 00:04:51,259 if you I really I 116 00:04:51,260 --> 00:04:53,839 looked up what should I use 117 00:04:53,840 --> 00:04:55,999 that a lot of once you can buy 118 00:04:56,000 --> 00:04:58,069 and yeah, this one is 119 00:04:58,070 --> 00:04:59,599 open source. And of course, I love open 120 00:04:59,600 --> 00:05:01,699 source, so I 121 00:05:01,700 --> 00:05:03,919 use that and never with the second 122 00:05:03,920 --> 00:05:05,659 monitor because of course, I never 123 00:05:05,660 --> 00:05:06,660 thought about that. 124 00:05:08,060 --> 00:05:09,500 So yes, 125 00:05:11,030 --> 00:05:12,589 it's about amateur telescope. 126 00:05:12,590 --> 00:05:14,899 Me first of all, what 127 00:05:14,900 --> 00:05:17,119 I often hear when I tell someone 128 00:05:17,120 --> 00:05:19,399 I mean, I'm at the 129 00:05:19,400 --> 00:05:20,870 People's Observatory of Munich, 130 00:05:21,980 --> 00:05:24,709 I did also some research in astronomy. 131 00:05:24,710 --> 00:05:26,779 And so I'm 132 00:05:26,780 --> 00:05:28,910 involved and I do 133 00:05:30,080 --> 00:05:32,249 I show people the observatory. 134 00:05:32,250 --> 00:05:34,339 I explain to them how telescopes 135 00:05:34,340 --> 00:05:36,799 work. And when I tell them, 136 00:05:36,800 --> 00:05:39,119 look, you can make a telescope yourself. 137 00:05:39,120 --> 00:05:41,269 Yeah, of course. I mean, it's an optical 138 00:05:41,270 --> 00:05:42,859 precision instrument. 139 00:05:42,860 --> 00:05:45,019 You have to you 140 00:05:45,020 --> 00:05:47,299 have to have expensive 141 00:05:47,300 --> 00:05:48,559 machinery. 142 00:05:48,560 --> 00:05:49,730 You have to 143 00:05:50,840 --> 00:05:52,909 know a lot about optics and 144 00:05:52,910 --> 00:05:53,569 stuff like that. 145 00:05:53,570 --> 00:05:54,739 Um, well, yeah, no, 146 00:05:56,540 --> 00:05:59,359 because you need the expensive machinery 147 00:05:59,360 --> 00:06:00,560 if you are going to do it 148 00:06:01,880 --> 00:06:02,989 with a machine. 149 00:06:02,990 --> 00:06:05,419 So if you're going to go huge, 150 00:06:05,420 --> 00:06:06,979 of course you're going to need a machine 151 00:06:06,980 --> 00:06:08,629 because we are talking about removing 152 00:06:08,630 --> 00:06:09,889 tons of glass here. 153 00:06:11,240 --> 00:06:13,579 But there's a big, 154 00:06:13,580 --> 00:06:14,580 big. But 155 00:06:15,830 --> 00:06:16,879 that sounds wrong. 156 00:06:16,880 --> 00:06:19,069 Um, if 157 00:06:19,070 --> 00:06:21,139 you if you're going to 158 00:06:21,140 --> 00:06:23,059 do it by hand and we're talking about 159 00:06:23,060 --> 00:06:25,129 telescopes roughly in the range 160 00:06:25,130 --> 00:06:27,199 up to a meter meter 161 00:06:27,200 --> 00:06:29,329 diameter, I imagine that that's a huge 162 00:06:29,330 --> 00:06:31,670 telescope. That's a big telescope. 163 00:06:33,890 --> 00:06:35,329 You can do it by hand. 164 00:06:35,330 --> 00:06:37,429 It's a lot of work, but you can 165 00:06:37,430 --> 00:06:39,529 do it with the 166 00:06:39,530 --> 00:06:40,530 mere 167 00:06:42,170 --> 00:06:44,539 attribute of a human being, not 168 00:06:44,540 --> 00:06:46,729 being able to repeat it, to repeat 169 00:06:46,730 --> 00:06:49,129 a motion again and again, the same way, 170 00:06:49,130 --> 00:06:51,259 the exact same way, especially 171 00:06:51,260 --> 00:06:52,260 if you tell the people, look, 172 00:06:53,480 --> 00:06:55,639 embrace the randomness, 173 00:06:55,640 --> 00:06:57,799 you can do it. You can make a telescope 174 00:06:57,800 --> 00:06:58,800 that beats 175 00:07:00,050 --> 00:07:02,179 manufactured telescopes, you can buy 176 00:07:02,180 --> 00:07:04,279 and you can pay 177 00:07:04,280 --> 00:07:05,869 a lot of money for it. 178 00:07:05,870 --> 00:07:08,539 So here, that's that's a short outline. 179 00:07:08,540 --> 00:07:10,879 So if you have more questions, 180 00:07:10,880 --> 00:07:11,880 write me an email, 181 00:07:12,980 --> 00:07:14,749 Twitter, whatever. 182 00:07:14,750 --> 00:07:16,399 Come to me personally, although we don't 183 00:07:16,400 --> 00:07:17,400 have that much time, 184 00:07:18,620 --> 00:07:21,139 we can I can talk to you about 185 00:07:21,140 --> 00:07:22,039 anything you want. 186 00:07:22,040 --> 00:07:24,169 I can tell you where you can get what 187 00:07:24,170 --> 00:07:25,249 you can get the stuff. 188 00:07:25,250 --> 00:07:27,439 And if you are interested, hit me 189 00:07:27,440 --> 00:07:29,629 up and I will I will share 190 00:07:29,630 --> 00:07:32,809 all the knowledge with you because 191 00:07:32,810 --> 00:07:35,509 again, the knowledge I got, 192 00:07:35,510 --> 00:07:37,759 I'm not the best there is. 193 00:07:37,760 --> 00:07:39,849 I happen to live in the same city with 194 00:07:39,850 --> 00:07:41,569 the best with the best guy there is in 195 00:07:41,570 --> 00:07:43,909 Germany. And if he is watching 196 00:07:43,910 --> 00:07:45,979 and I'm sure he's watching, thank you 197 00:07:45,980 --> 00:07:47,839 for showing me that and for making it 198 00:07:47,840 --> 00:07:49,909 possible that 199 00:07:49,910 --> 00:07:52,519 I can make my own telescopes. 200 00:07:52,520 --> 00:07:54,619 I haven't finished a single one yet 201 00:07:54,620 --> 00:07:56,569 because I always rework stuff three or 202 00:07:56,570 --> 00:07:58,909 four times, including those slides. 203 00:07:58,910 --> 00:07:59,989 Yeah. So 204 00:08:01,310 --> 00:08:02,659 why do I need a telescope? 205 00:08:02,660 --> 00:08:05,239 I mean, I can go 206 00:08:05,240 --> 00:08:07,129 out in the dark. Dark is a very important 207 00:08:07,130 --> 00:08:09,679 part of it. Astronomy works better 208 00:08:09,680 --> 00:08:11,209 if you can see the stars 209 00:08:13,400 --> 00:08:14,419 except astronomy. 210 00:08:14,420 --> 00:08:15,499 But we're not talking about here. 211 00:08:15,500 --> 00:08:17,629 We're talking optical astronomy. 212 00:08:17,630 --> 00:08:19,789 Why would I need to I mean, I do have an 213 00:08:19,790 --> 00:08:20,899 eye. I can see the stars. 214 00:08:20,900 --> 00:08:21,919 I can see the Milky Way. 215 00:08:21,920 --> 00:08:23,419 It's an impressive view. 216 00:08:23,420 --> 00:08:26,179 And I know people who 217 00:08:26,180 --> 00:08:28,339 because it was such a nice you, it was 218 00:08:28,340 --> 00:08:29,269 a clear night. 219 00:08:29,270 --> 00:08:30,979 It was lovely. 220 00:08:30,980 --> 00:08:33,048 They went outside, they carried the 221 00:08:33,049 --> 00:08:35,178 telescope. They assembled their 222 00:08:35,179 --> 00:08:37,279 telescope on sight 223 00:08:37,280 --> 00:08:39,408 and thought, well, screw it, I'm going to 224 00:08:39,409 --> 00:08:40,999 lie down on the grass and have a look at 225 00:08:41,000 --> 00:08:42,859 the sky and enjoy it. 226 00:08:42,860 --> 00:08:44,089 That's that's it. 227 00:08:44,090 --> 00:08:46,129 That's about amateur astronomy. 228 00:08:46,130 --> 00:08:47,959 You love to do it. 229 00:08:47,960 --> 00:08:49,159 And. 230 00:08:49,160 --> 00:08:51,529 Well, if that works for you, 231 00:08:51,530 --> 00:08:52,530 go for it. 232 00:08:53,540 --> 00:08:55,849 And if you make a telescope, don't let 233 00:08:55,850 --> 00:08:58,339 anyone tell you, 234 00:08:58,340 --> 00:09:00,619 oh, that doesn't work, 235 00:09:00,620 --> 00:09:02,839 if you know it works or you do it, 236 00:09:02,840 --> 00:09:05,179 it's the most important thing 237 00:09:05,180 --> 00:09:07,549 you can make it like you want. 238 00:09:07,550 --> 00:09:09,889 So here are some incentives. 239 00:09:09,890 --> 00:09:11,959 First of all, with the telescope, you can 240 00:09:11,960 --> 00:09:14,029 have a look at galaxies like 241 00:09:14,030 --> 00:09:15,030 that one. 242 00:09:15,710 --> 00:09:17,959 This one is also 243 00:09:17,960 --> 00:09:20,149 from a ground based telescope. 244 00:09:20,150 --> 00:09:22,309 But as you can see, those guys, 245 00:09:24,530 --> 00:09:26,570 well, they do it for a living. 246 00:09:27,690 --> 00:09:28,939 These are the European Southern 247 00:09:28,940 --> 00:09:31,009 Observatory. So you won't see that 248 00:09:31,010 --> 00:09:32,419 in the telescope. 249 00:09:32,420 --> 00:09:34,489 But you can see 250 00:09:34,490 --> 00:09:35,539 a faint blob. 251 00:09:35,540 --> 00:09:37,969 You will see that region here. 252 00:09:37,970 --> 00:09:40,219 If you don't like that, well, 253 00:09:40,220 --> 00:09:42,499 then I have bad news for you. 254 00:09:42,500 --> 00:09:45,019 There are better objects like Albireo 255 00:09:45,020 --> 00:09:46,020 here. 256 00:09:46,550 --> 00:09:47,750 This is a double star 257 00:09:48,800 --> 00:09:51,229 and this is 258 00:09:51,230 --> 00:09:53,779 a star you can see with the naked eye. 259 00:09:53,780 --> 00:09:55,879 But in the telescope, it resolves to two 260 00:09:55,880 --> 00:09:57,529 stars orbiting each other. 261 00:09:57,530 --> 00:10:00,139 You don't see the orbiting, obviously, 262 00:10:00,140 --> 00:10:02,659 and the one is blue, the once red. 263 00:10:02,660 --> 00:10:05,269 So here you can see astronomy. 264 00:10:05,270 --> 00:10:07,609 If you had astronomy in school, 265 00:10:07,610 --> 00:10:10,159 you had astronomy. And at university, 266 00:10:10,160 --> 00:10:11,989 that tells you some stars I read. 267 00:10:11,990 --> 00:10:13,009 Some stars are blue. 268 00:10:13,010 --> 00:10:14,789 Yeah. Wow. 269 00:10:14,790 --> 00:10:17,269 If you see the telescope, then 270 00:10:17,270 --> 00:10:19,639 it's something completely different. 271 00:10:19,640 --> 00:10:21,679 If the more you know, the more this 272 00:10:21,680 --> 00:10:23,899 experience on the eyepiece is 273 00:10:23,900 --> 00:10:24,900 enhanced 274 00:10:26,000 --> 00:10:28,039 and planets. 275 00:10:28,040 --> 00:10:30,139 OK, that's Pluto. Sorry, old habits die 276 00:10:30,140 --> 00:10:31,420 hard planets. 277 00:10:33,350 --> 00:10:35,479 This one is actually what you 278 00:10:35,480 --> 00:10:37,609 would of course not know that 279 00:10:37,610 --> 00:10:39,229 details because there's still an 280 00:10:39,230 --> 00:10:41,659 atmosphere between and those are probably 281 00:10:41,660 --> 00:10:43,999 some thousand pictures 282 00:10:44,000 --> 00:10:45,229 now that's Hubble. 283 00:10:45,230 --> 00:10:46,699 Screw that. 284 00:10:46,700 --> 00:10:49,219 So you can get those 285 00:10:49,220 --> 00:10:51,319 quality pictures similar to pictures with 286 00:10:51,320 --> 00:10:52,459 an amateur telescope. 287 00:10:52,460 --> 00:10:54,589 But you need to take a video. 288 00:10:54,590 --> 00:10:56,689 You cut out parts which are good, 289 00:10:56,690 --> 00:10:58,819 which you like the software 290 00:10:58,820 --> 00:11:00,859 for that, of course. And you end up 291 00:11:00,860 --> 00:11:02,809 stacking like two or three thousand 292 00:11:02,810 --> 00:11:05,119 pictures and then you get good quality. 293 00:11:05,120 --> 00:11:07,249 It will be if you have a look at it 294 00:11:07,250 --> 00:11:10,039 yourself, it will be a bit blurrier, 295 00:11:10,040 --> 00:11:12,469 but you will definitely see the stripes 296 00:11:12,470 --> 00:11:14,749 and the and the big 297 00:11:14,750 --> 00:11:16,009 red spot. 298 00:11:16,010 --> 00:11:18,499 Fun fact. This big red spot 299 00:11:18,500 --> 00:11:20,629 is twice the size of the 300 00:11:20,630 --> 00:11:23,179 earth. So big is 301 00:11:23,180 --> 00:11:24,180 quite a good 302 00:11:25,880 --> 00:11:27,029 name for it, I think. 303 00:11:28,550 --> 00:11:29,699 Yeah. 304 00:11:29,700 --> 00:11:30,700 Let's go back. 305 00:11:33,100 --> 00:11:35,409 So you need light, you need 306 00:11:35,410 --> 00:11:37,509 what the telescope does, it enhances your 307 00:11:37,510 --> 00:11:38,700 sight, your eyesight, 308 00:11:40,630 --> 00:11:42,759 it doesn't make very visible, 309 00:11:42,760 --> 00:11:45,429 you don't see, but it can 310 00:11:45,430 --> 00:11:47,649 make light and regents' visible. 311 00:11:47,650 --> 00:11:49,989 You don't see because it collects light 312 00:11:49,990 --> 00:11:51,699 bundles up the light. 313 00:11:51,700 --> 00:11:52,989 So how do you do that? 314 00:11:52,990 --> 00:11:55,089 Well, there is the classic. 315 00:11:55,090 --> 00:11:57,340 As you saw, a lens 316 00:11:58,750 --> 00:12:00,669 light comes in, focus comes out. 317 00:12:00,670 --> 00:12:01,869 You can't explain that. 318 00:12:01,870 --> 00:12:04,329 Well, actually, we can, but that's 319 00:12:04,330 --> 00:12:06,369 how this thing works. 320 00:12:06,370 --> 00:12:08,739 Everybody who wears glasses, who has used 321 00:12:08,740 --> 00:12:11,319 a binocular or 322 00:12:11,320 --> 00:12:12,669 whatever you do, 323 00:12:13,780 --> 00:12:15,399 that's that's the main principle. 324 00:12:15,400 --> 00:12:17,769 And that's what most people imagine 325 00:12:17,770 --> 00:12:19,269 when they think about a telescope. 326 00:12:21,250 --> 00:12:22,509 Then again, mirrors, 327 00:12:24,010 --> 00:12:27,009 mirrors have one huge advantage. 328 00:12:27,010 --> 00:12:29,139 You have to use only one 329 00:12:29,140 --> 00:12:30,609 surface. So they're cheaper 330 00:12:30,610 --> 00:12:31,689 manufacturing. 331 00:12:31,690 --> 00:12:34,089 You can support them from the back. 332 00:12:34,090 --> 00:12:35,499 They're easier to build. 333 00:12:35,500 --> 00:12:37,749 So nowadays, mirrors are 334 00:12:37,750 --> 00:12:38,750 the way to go. 335 00:12:40,030 --> 00:12:42,279 Doesn't matter how big if you Bill, if 336 00:12:42,280 --> 00:12:44,769 you make a six inch telescope or 337 00:12:44,770 --> 00:12:47,439 a eight meter telescope 338 00:12:47,440 --> 00:12:50,049 like the VLT is or a 40 339 00:12:50,050 --> 00:12:52,629 minute or a 40 meter telescope 340 00:12:52,630 --> 00:12:54,789 like the ELT is going 341 00:12:54,790 --> 00:12:56,739 to be, let's let's see that. 342 00:12:56,740 --> 00:12:58,839 I would love to see that 40 meter 343 00:12:58,840 --> 00:13:01,269 telescope. I mean, that's astronomy 344 00:13:01,270 --> 00:13:03,099 porn. I mean, we're talking hot stuff 345 00:13:03,100 --> 00:13:04,209 here. 346 00:13:04,210 --> 00:13:06,339 So and what that 347 00:13:06,340 --> 00:13:08,529 what this telescope does is basically 348 00:13:08,530 --> 00:13:10,089 you have one main component that's a 349 00:13:10,090 --> 00:13:11,380 Newton, as you can see, 350 00:13:12,430 --> 00:13:14,529 and by the curvature of the 351 00:13:14,530 --> 00:13:16,779 mirror of the main mirror, let's call 352 00:13:16,780 --> 00:13:19,029 it M one here, mirror 353 00:13:19,030 --> 00:13:20,679 one or two. 354 00:13:20,680 --> 00:13:22,359 You can imagine how this is how this 355 00:13:22,360 --> 00:13:24,669 works. Um, you 356 00:13:24,670 --> 00:13:27,309 basically bend 357 00:13:27,310 --> 00:13:28,449 the light in one direction. 358 00:13:28,450 --> 00:13:30,699 You focus in one direction, and then you 359 00:13:30,700 --> 00:13:32,409 have the eyepiece or the camera there or 360 00:13:32,410 --> 00:13:34,569 whatever you want or 361 00:13:34,570 --> 00:13:36,789 your cooking 362 00:13:36,790 --> 00:13:38,919 stove and you cook your pasta if 363 00:13:38,920 --> 00:13:40,149 the mirror is big enough and you have the 364 00:13:40,150 --> 00:13:41,409 sun. 365 00:13:41,410 --> 00:13:43,839 So that's how it works. 366 00:13:43,840 --> 00:13:45,219 The basic concept. 367 00:13:45,220 --> 00:13:47,349 But now, since I mentioned 368 00:13:47,350 --> 00:13:49,059 BASIX, let's go to the basics. 369 00:13:50,200 --> 00:13:52,399 This are some 370 00:13:52,400 --> 00:13:54,789 circles, some colored circles, 371 00:13:54,790 --> 00:13:57,399 what the present is here. 372 00:13:57,400 --> 00:14:00,279 Imagine that being seven millimeters. 373 00:14:00,280 --> 00:14:02,559 That's the eye opening 374 00:14:02,560 --> 00:14:05,230 of a healthy young adult. 375 00:14:06,640 --> 00:14:09,190 At extremely low light conditions. 376 00:14:10,840 --> 00:14:12,909 So that's the maximum your 377 00:14:12,910 --> 00:14:14,339 eye can open up. 378 00:14:15,490 --> 00:14:17,619 And if you go above 379 00:14:17,620 --> 00:14:20,409 30, I have bad news for you. 380 00:14:20,410 --> 00:14:22,359 That's not going to be seven millimeters. 381 00:14:22,360 --> 00:14:24,429 It's going to decrease with age 382 00:14:24,430 --> 00:14:26,529 people of the age 383 00:14:26,530 --> 00:14:28,689 of 60, 70, they're 384 00:14:28,690 --> 00:14:31,539 talking five millimeters. 385 00:14:31,540 --> 00:14:33,819 So you can 386 00:14:33,820 --> 00:14:34,820 see, well, 387 00:14:35,920 --> 00:14:38,349 OK, that's surprisingly 388 00:14:38,350 --> 00:14:41,109 big. If you actually I did that, 389 00:14:41,110 --> 00:14:43,419 I draw it and draw it actually 390 00:14:43,420 --> 00:14:45,639 with millimeters and scale it down 391 00:14:45,640 --> 00:14:48,549 to fit in the slide. And that's big. 392 00:14:48,550 --> 00:14:50,679 Yes, it is surprisingly big, but 393 00:14:51,760 --> 00:14:53,229 it's bigger. 394 00:14:53,230 --> 00:14:55,329 The the circle 395 00:14:55,330 --> 00:14:57,699 next to that is a 50 396 00:14:57,700 --> 00:14:59,800 represents a 50 millimeter 397 00:15:00,940 --> 00:15:04,059 optical, the 50 millimeter aperture. 398 00:15:04,060 --> 00:15:06,489 So this is 399 00:15:06,490 --> 00:15:07,899 the cheap telescope. 400 00:15:07,900 --> 00:15:10,119 You're going to buy your kid for one 401 00:15:10,120 --> 00:15:11,120 hundred euros. 402 00:15:11,800 --> 00:15:13,239 Please don't do that. 403 00:15:13,240 --> 00:15:15,459 The mechanics are crap 404 00:15:15,460 --> 00:15:16,479 most of the time. 405 00:15:16,480 --> 00:15:18,579 So they 406 00:15:18,580 --> 00:15:20,739 end up kids end up being frustrated 407 00:15:20,740 --> 00:15:23,049 and drove and driven away from astronomy 408 00:15:23,050 --> 00:15:24,050 just because of that. 409 00:15:25,750 --> 00:15:28,779 And binoculars are the same diameter. 410 00:15:28,780 --> 00:15:31,299 So you can buy for 100 411 00:15:31,300 --> 00:15:34,419 euros. Really, really this vernaculars 412 00:15:34,420 --> 00:15:36,309 with two times this. 413 00:15:36,310 --> 00:15:38,199 Oh, this aperture. 414 00:15:38,200 --> 00:15:40,449 And have a look at the sky. 415 00:15:40,450 --> 00:15:41,919 It's not expensive hobby. 416 00:15:41,920 --> 00:15:43,840 It's really, really good 417 00:15:45,110 --> 00:15:47,319 what you can see. And people put aside 418 00:15:47,320 --> 00:15:49,749 the big telescopes and use a binoculars. 419 00:15:49,750 --> 00:15:51,969 Every telescope has its own sky. 420 00:15:51,970 --> 00:15:53,289 You see different things, different 421 00:15:53,290 --> 00:15:54,369 magnifications. 422 00:15:54,370 --> 00:15:56,620 And I mean, it's 423 00:15:57,910 --> 00:15:59,260 it's really, really 424 00:16:00,940 --> 00:16:02,589 you can start and you can start small. 425 00:16:02,590 --> 00:16:04,539 That's what I want to say here. 426 00:16:04,540 --> 00:16:06,399 Then we have a 140 millimeter. 427 00:16:06,400 --> 00:16:08,769 That's a typical starter 428 00:16:08,770 --> 00:16:10,179 telescope. 429 00:16:10,180 --> 00:16:12,459 And this here, 430 00:16:12,460 --> 00:16:14,199 this is no moon. 431 00:16:14,200 --> 00:16:16,299 This is a one meter 432 00:16:16,300 --> 00:16:18,759 mirror. It doesn't fit in this light. 433 00:16:18,760 --> 00:16:19,760 So 434 00:16:21,370 --> 00:16:22,370 as you can see, 435 00:16:23,800 --> 00:16:25,899 most of you already know it, 436 00:16:25,900 --> 00:16:28,059 but the surface area grows 437 00:16:28,060 --> 00:16:29,439 exponential. 438 00:16:29,440 --> 00:16:31,989 So you 439 00:16:31,990 --> 00:16:34,149 you increase the diameter by 440 00:16:34,150 --> 00:16:36,249 two. And as you can see here, 441 00:16:36,250 --> 00:16:38,739 the surface goes up by four. 442 00:16:38,740 --> 00:16:39,740 So 443 00:16:42,520 --> 00:16:43,520 in the end. 444 00:16:44,870 --> 00:16:46,939 You collect more and more 445 00:16:46,940 --> 00:16:49,339 light and light is 446 00:16:49,340 --> 00:16:51,349 extremely important here because are 447 00:16:51,350 --> 00:16:53,449 trying to get the last photon out of that 448 00:16:53,450 --> 00:16:56,299 object or 449 00:16:56,300 --> 00:16:57,769 the platform that hits Earth. 450 00:16:58,790 --> 00:17:01,099 Another thing is that 451 00:17:01,100 --> 00:17:02,100 with diameter, 452 00:17:03,200 --> 00:17:06,199 you also increase the resolution. 453 00:17:06,200 --> 00:17:08,419 So here that that's the so-called 454 00:17:08,420 --> 00:17:10,969 baseline, actually, 455 00:17:10,970 --> 00:17:13,098 what to get to the 456 00:17:13,099 --> 00:17:16,129 resolution, you don't need that part. 457 00:17:16,130 --> 00:17:18,199 That part simply collects light. 458 00:17:18,200 --> 00:17:20,419 You could just use this the part 459 00:17:20,420 --> 00:17:22,489 on the left edge and on the right 460 00:17:22,490 --> 00:17:24,799 edge, and you would have that 461 00:17:24,800 --> 00:17:26,629 increased angular resolution. 462 00:17:26,630 --> 00:17:27,858 And in fact, we're doing that. 463 00:17:27,859 --> 00:17:30,529 It's called interferometry astronomy. 464 00:17:30,530 --> 00:17:32,690 It works great with with 465 00:17:34,460 --> 00:17:35,839 radio telescopes. 466 00:17:35,840 --> 00:17:38,329 But they with 467 00:17:38,330 --> 00:17:40,789 optical telescopes, they are right about 468 00:17:40,790 --> 00:17:43,339 bringing it to functionality. 469 00:17:43,340 --> 00:17:45,589 But it's still it's 470 00:17:45,590 --> 00:17:47,689 still a happy road 471 00:17:47,690 --> 00:17:49,429 to go down a bumpy road. 472 00:17:49,430 --> 00:17:50,539 Sorry. 473 00:17:50,540 --> 00:17:52,309 I'm sorry. 474 00:17:52,310 --> 00:17:54,889 I'm I'm totally on coughing 475 00:17:54,890 --> 00:17:57,289 and you know how it is 476 00:17:57,290 --> 00:17:58,339 a big audience. 477 00:17:58,340 --> 00:18:00,619 You get the bright light 478 00:18:00,620 --> 00:18:02,509 in your eyes and you can see the people 479 00:18:02,510 --> 00:18:04,939 down there and that's 480 00:18:04,940 --> 00:18:05,449 how it goes. 481 00:18:05,450 --> 00:18:07,669 So it goes it 482 00:18:07,670 --> 00:18:08,950 goes investigational. 483 00:18:10,220 --> 00:18:11,779 Um, yeah. 484 00:18:11,780 --> 00:18:14,029 So again, the types of telescopes, 485 00:18:14,030 --> 00:18:15,030 how it works 486 00:18:16,550 --> 00:18:18,899 here, the light goes, 487 00:18:18,900 --> 00:18:20,899 it goes in from the front. 488 00:18:20,900 --> 00:18:22,099 And because it's a mirror and it's 489 00:18:22,100 --> 00:18:24,289 reflected, you do have to have that 490 00:18:24,290 --> 00:18:25,279 part here. 491 00:18:25,280 --> 00:18:27,379 The second mirror which goes 492 00:18:27,380 --> 00:18:29,509 up and here you 493 00:18:29,510 --> 00:18:30,980 have a typical 494 00:18:33,140 --> 00:18:34,549 singalongs telescope. 495 00:18:34,550 --> 00:18:36,889 You can see you have color errors 496 00:18:36,890 --> 00:18:38,329 here. But that's not the point. 497 00:18:38,330 --> 00:18:40,399 The point is what I want to make 498 00:18:40,400 --> 00:18:42,979 is here you have two surfaces. 499 00:18:42,980 --> 00:18:45,829 Here you have one one surface 500 00:18:45,830 --> 00:18:48,139 doesn't have to comply with anything. 501 00:18:48,140 --> 00:18:49,279 You can have one surface. 502 00:18:49,280 --> 00:18:50,809 You can make it work. 503 00:18:50,810 --> 00:18:52,009 And at the moment, it works. 504 00:18:52,010 --> 00:18:53,389 It works here. 505 00:18:53,390 --> 00:18:55,549 You have to make two surfaces, work 506 00:18:55,550 --> 00:18:56,869 with each other. 507 00:18:56,870 --> 00:18:59,239 And that that's much, much harder, 508 00:18:59,240 --> 00:19:01,279 because if you make it if you happen to 509 00:19:01,280 --> 00:19:03,439 make it wrong, it can go totally it 510 00:19:03,440 --> 00:19:05,539 can totally go south. 511 00:19:05,540 --> 00:19:08,479 If those two are not 512 00:19:08,480 --> 00:19:10,609 centered properly, the 513 00:19:10,610 --> 00:19:12,709 whole optical 514 00:19:12,710 --> 00:19:14,419 capabilities of the telescope got really, 515 00:19:14,420 --> 00:19:15,839 really bad. 516 00:19:15,840 --> 00:19:17,959 So, yeah, 517 00:19:17,960 --> 00:19:20,089 not the map of making 518 00:19:20,090 --> 00:19:22,130 the telescope actually doing it. 519 00:19:24,380 --> 00:19:25,849 First of all, I will talk about the 520 00:19:25,850 --> 00:19:26,850 optics. 521 00:19:28,280 --> 00:19:29,960 This is the part which is. 522 00:19:31,780 --> 00:19:34,059 Most complicated, most, 523 00:19:34,060 --> 00:19:35,939 I'd say complicated is the wrong word, 524 00:19:37,480 --> 00:19:39,279 less people are familiar with optics than 525 00:19:39,280 --> 00:19:41,689 they are with making words 526 00:19:41,690 --> 00:19:43,809 align and work so that 527 00:19:43,810 --> 00:19:44,810 something works. 528 00:19:45,940 --> 00:19:48,249 So that's the new part 529 00:19:48,250 --> 00:19:50,319 for most of you. I guess I happen 530 00:19:50,320 --> 00:19:52,089 to know that at least one person in the 531 00:19:52,090 --> 00:19:54,879 audience is already 532 00:19:54,880 --> 00:19:56,169 thinking about making a telescope. 533 00:19:56,170 --> 00:19:58,389 So he maybe knows more about that. 534 00:19:58,390 --> 00:19:59,769 But it's not complicated. 535 00:19:59,770 --> 00:20:00,770 It's not hot. 536 00:20:02,290 --> 00:20:03,669 What would you do? What would you make 537 00:20:03,670 --> 00:20:05,729 your own telescope 538 00:20:05,730 --> 00:20:06,730 ask? 539 00:20:09,040 --> 00:20:10,040 Well, basically, 540 00:20:12,250 --> 00:20:14,979 because you 541 00:20:16,510 --> 00:20:17,619 are flexible, 542 00:20:18,640 --> 00:20:20,859 you can make it the way you want. 543 00:20:20,860 --> 00:20:23,019 If you want to make a telescope 544 00:20:23,020 --> 00:20:25,089 that pink, you can make a 545 00:20:25,090 --> 00:20:26,499 telescope that's pink. 546 00:20:26,500 --> 00:20:27,729 If you want to make a telescope, that's 547 00:20:27,730 --> 00:20:29,199 rubbish. You can make a telescope. 548 00:20:29,200 --> 00:20:30,159 That's rubbish. 549 00:20:30,160 --> 00:20:31,749 You can make it however you like. 550 00:20:33,310 --> 00:20:35,199 And you can also include a rocket 551 00:20:35,200 --> 00:20:37,449 launches, which was suggested by 552 00:20:37,450 --> 00:20:38,799 somebody. 553 00:20:38,800 --> 00:20:40,869 But I wouldn't recommend most 554 00:20:40,870 --> 00:20:42,519 other astronomers don't like a rocket 555 00:20:42,520 --> 00:20:43,659 launcher being on your telescope and 556 00:20:43,660 --> 00:20:45,879 destroying the hard work 557 00:20:45,880 --> 00:20:47,679 and the quality. 558 00:20:47,680 --> 00:20:49,659 Again, if you want to make it, you can 559 00:20:49,660 --> 00:20:51,609 make it as good as you want. 560 00:20:51,610 --> 00:20:53,679 You can go through 561 00:20:53,680 --> 00:20:56,529 and plus one iterations and 562 00:20:56,530 --> 00:20:58,419 still add another one. 563 00:20:58,420 --> 00:21:00,549 You don't care, OK, you 564 00:21:00,550 --> 00:21:02,529 can't because at one point you want to 565 00:21:02,530 --> 00:21:04,839 use it actually and make something 566 00:21:04,840 --> 00:21:06,879 with it. But that's where I'm stuck. 567 00:21:06,880 --> 00:21:08,589 I'm making the iterations. 568 00:21:10,780 --> 00:21:13,209 I started writing my mirror from scratch 569 00:21:13,210 --> 00:21:14,210 three times now 570 00:21:15,850 --> 00:21:17,979 so you can adjust that 571 00:21:17,980 --> 00:21:19,929 part if you need the telescope. 572 00:21:19,930 --> 00:21:22,119 That's only going to work for 573 00:21:22,120 --> 00:21:23,949 infrared light because you want to make 574 00:21:23,950 --> 00:21:24,950 an infrared 575 00:21:26,770 --> 00:21:30,009 an infrared transmission path 576 00:21:30,010 --> 00:21:30,999 go for it. 577 00:21:31,000 --> 00:21:33,029 You don't need you don't need to invest 578 00:21:33,030 --> 00:21:34,869 that much time in it. 579 00:21:34,870 --> 00:21:36,969 You just need to polish it 580 00:21:36,970 --> 00:21:37,869 roughly. 581 00:21:37,870 --> 00:21:40,869 And you it works. 582 00:21:40,870 --> 00:21:43,539 You don't you don't have that high 583 00:21:43,540 --> 00:21:45,789 that high specs as you have 584 00:21:45,790 --> 00:21:48,729 in optical with optical light. 585 00:21:48,730 --> 00:21:50,829 The price, of course, although 586 00:21:50,830 --> 00:21:52,989 a small disclaimer here, if you 587 00:21:52,990 --> 00:21:55,869 go if you're going to make a telescope 588 00:21:55,870 --> 00:21:58,029 10 inch big, you want to save 589 00:21:58,030 --> 00:21:59,290 money, don't do it. 590 00:22:01,300 --> 00:22:03,459 You can buy really decent 591 00:22:03,460 --> 00:22:05,649 telescopes nowadays 592 00:22:05,650 --> 00:22:08,529 with up to 16 inch 593 00:22:08,530 --> 00:22:10,839 and you would still 594 00:22:10,840 --> 00:22:12,549 save money. 595 00:22:12,550 --> 00:22:14,799 I'm talking about raw cost, not 596 00:22:14,800 --> 00:22:16,869 not the time invested. 597 00:22:16,870 --> 00:22:18,339 If you calculate that it goes through the 598 00:22:18,340 --> 00:22:20,439 roof, I'm 599 00:22:20,440 --> 00:22:21,779 talking about cash. 600 00:22:21,780 --> 00:22:23,619 Take your hand and put and put on the 601 00:22:23,620 --> 00:22:24,620 counter. 602 00:22:25,240 --> 00:22:27,429 You will save money up to six Netsch, 603 00:22:27,430 --> 00:22:29,529 but make a small 604 00:22:29,530 --> 00:22:30,530 telescope, 605 00:22:31,720 --> 00:22:33,249 one that you would like to use, of 606 00:22:33,250 --> 00:22:35,409 course, to get the experience, 607 00:22:35,410 --> 00:22:37,029 to see how it is, how it works, where the 608 00:22:37,030 --> 00:22:39,189 problems are, and then go 609 00:22:39,190 --> 00:22:41,349 back. If you go really big, where 610 00:22:41,350 --> 00:22:43,599 we go, if you go above 611 00:22:43,600 --> 00:22:45,789 eighteen, twenty, twenty four, 612 00:22:45,790 --> 00:22:48,399 thirty three inches, 613 00:22:48,400 --> 00:22:49,539 40 inches, 614 00:22:51,190 --> 00:22:54,099 you I mean the sky's the limit here. 615 00:22:54,100 --> 00:22:56,169 People are running amateur 616 00:22:56,170 --> 00:22:58,239 telescopes with 617 00:22:58,240 --> 00:22:59,980 one meter diameter. 618 00:23:01,150 --> 00:23:03,849 That's insane. 619 00:23:03,850 --> 00:23:06,399 If a guy arrives at the site 620 00:23:06,400 --> 00:23:07,569 with a trailer 621 00:23:08,860 --> 00:23:10,599 and he tells yeah, that thing is full 622 00:23:10,600 --> 00:23:13,359 with the telescope, with one 623 00:23:13,360 --> 00:23:15,609 single telescope and 624 00:23:15,610 --> 00:23:17,769 you have to climb up a ladder two 625 00:23:17,770 --> 00:23:19,959 and a half meters to get to the 626 00:23:19,960 --> 00:23:21,519 eyepiece. 627 00:23:21,520 --> 00:23:23,279 You know what I'm talking about? 628 00:23:23,280 --> 00:23:24,970 Why I say it's insane. 629 00:23:28,190 --> 00:23:30,409 Crazy, but then 630 00:23:30,410 --> 00:23:32,569 again, we are at the hacker 631 00:23:32,570 --> 00:23:34,909 Congress between between the holidays, 632 00:23:34,910 --> 00:23:36,109 I guess we are crazy, too, 633 00:23:38,510 --> 00:23:40,209 and, of course, availability. 634 00:23:41,860 --> 00:23:43,420 Telescopes above 18 inch. 635 00:23:44,760 --> 00:23:47,759 Light construction light 636 00:23:47,760 --> 00:23:49,589 that you can carry with one person that's 637 00:23:49,590 --> 00:23:50,729 not considered like their. 638 00:23:53,240 --> 00:23:54,409 They're not that abandoned. 639 00:23:54,410 --> 00:23:57,709 There are some small manufacturers 640 00:23:57,710 --> 00:24:01,069 and you order it today, 641 00:24:01,070 --> 00:24:04,069 you will have it at the 30, 33 642 00:24:04,070 --> 00:24:05,389 maybe. 643 00:24:05,390 --> 00:24:07,039 So we're talking to two years, limited 644 00:24:07,040 --> 00:24:09,499 time. And in that time, of course, you 645 00:24:09,500 --> 00:24:11,570 will be able to make your own TELESTAR. 646 00:24:13,400 --> 00:24:15,869 And most importantly, because 647 00:24:15,870 --> 00:24:16,870 you fracking. Can 648 00:24:18,080 --> 00:24:19,080 you. 649 00:24:25,810 --> 00:24:28,119 And I mean, all those outlines 650 00:24:28,120 --> 00:24:30,339 are basically why 651 00:24:30,340 --> 00:24:33,529 should I built my own 3D printer back 652 00:24:33,530 --> 00:24:34,479 back in the day? 653 00:24:34,480 --> 00:24:36,579 I mean, like two years ago, you had no 654 00:24:36,580 --> 00:24:38,569 option. You had to build it yourself. 655 00:24:38,570 --> 00:24:40,659 But nowadays in Germany at least, 656 00:24:40,660 --> 00:24:42,939 you pay five hundred seven hundred euros 657 00:24:42,940 --> 00:24:45,099 and you get a decent one, not the 658 00:24:45,100 --> 00:24:47,379 best one, and still has issues, but 659 00:24:47,380 --> 00:24:49,029 you get a good one. 660 00:24:49,030 --> 00:24:51,739 But many people still do it 661 00:24:51,740 --> 00:24:54,159 their own 3D printers, they 662 00:24:54,160 --> 00:24:56,679 I mean, there's Linux from scratch. 663 00:24:56,680 --> 00:24:58,749 I think I still don't understand, but 664 00:24:58,750 --> 00:25:00,959 maybe that's my my 665 00:25:00,960 --> 00:25:03,069 my lack of understanding that. 666 00:25:03,070 --> 00:25:05,619 But still, people 667 00:25:05,620 --> 00:25:07,839 do things themselves, and that's 668 00:25:07,840 --> 00:25:10,659 always the reason because 669 00:25:10,660 --> 00:25:11,589 I wanted better. 670 00:25:11,590 --> 00:25:13,749 I want it now. I want to 671 00:25:13,750 --> 00:25:15,969 I want it however I 672 00:25:15,970 --> 00:25:18,549 want. And that's so 673 00:25:18,550 --> 00:25:19,779 the shopping list. 674 00:25:19,780 --> 00:25:21,939 So cool. 675 00:25:21,940 --> 00:25:22,940 I want to do that. 676 00:25:24,310 --> 00:25:26,499 And you start and you said, well, I want 677 00:25:26,500 --> 00:25:28,599 to I want to go to the 678 00:25:28,600 --> 00:25:30,369 hardware store and get the stuff. 679 00:25:30,370 --> 00:25:32,410 So what you need is a piece of glass. 680 00:25:35,620 --> 00:25:37,139 A small disclaimer here, you need special 681 00:25:37,140 --> 00:25:39,209 glasses, not always if you make 682 00:25:39,210 --> 00:25:41,459 small telescopes. I know a guy who made 683 00:25:41,460 --> 00:25:43,709 his, uh, his two really 684 00:25:43,710 --> 00:25:44,999 small telescopes, four inch 685 00:25:46,170 --> 00:25:48,599 with standard 686 00:25:48,600 --> 00:25:50,789 window glass, which is 687 00:25:50,790 --> 00:25:53,159 a nightmare if you did. 688 00:25:53,160 --> 00:25:55,619 But it's OK, I guess, 689 00:25:55,620 --> 00:25:57,209 for that size. 690 00:25:57,210 --> 00:25:58,469 And it's cheap. 691 00:25:58,470 --> 00:26:00,629 It's the chip. He paid exactly nothing 692 00:26:00,630 --> 00:26:01,829 for it. 693 00:26:01,830 --> 00:26:04,169 I mean, we're talking four inches. 694 00:26:04,170 --> 00:26:05,429 That's the size. 695 00:26:05,430 --> 00:26:07,739 That's a piece a piece of glass 696 00:26:07,740 --> 00:26:09,869 you get from the from from 697 00:26:09,870 --> 00:26:10,979 the from the junk. 698 00:26:10,980 --> 00:26:12,389 I mean, from the scrap. 699 00:26:12,390 --> 00:26:14,519 It's like, yeah, you can get 700 00:26:14,520 --> 00:26:16,619 that. Nobody cares about that size of 701 00:26:16,620 --> 00:26:18,149 glass then you need it. 702 00:26:18,150 --> 00:26:20,429 All that tall can be another piece 703 00:26:20,430 --> 00:26:22,979 of glass, can be granite, 704 00:26:22,980 --> 00:26:25,319 can be ceramics, can 705 00:26:25,320 --> 00:26:27,959 be a composite construction 706 00:26:27,960 --> 00:26:30,179 that you take two plates, 707 00:26:30,180 --> 00:26:32,459 two bathroom 708 00:26:32,460 --> 00:26:34,619 tiles, you glue them together, 709 00:26:34,620 --> 00:26:36,719 you put them together with some cement 710 00:26:36,720 --> 00:26:37,720 or some 711 00:26:38,970 --> 00:26:42,029 some clay or whatever you find 712 00:26:42,030 --> 00:26:44,099 and seal 713 00:26:44,100 --> 00:26:45,419 it around. That's important. 714 00:26:45,420 --> 00:26:47,899 But if you want to start it, Google, 715 00:26:47,900 --> 00:26:50,129 Google, Google, Google, or ask me or 716 00:26:50,130 --> 00:26:51,479 you can write me in, I can tell you what 717 00:26:51,480 --> 00:26:53,759 you what you will find your tips 718 00:26:53,760 --> 00:26:55,949 and what you find your materials, because 719 00:26:55,950 --> 00:26:57,900 many, many details are omitted here. 720 00:26:59,130 --> 00:27:00,869 Like 99 percent of the details are 721 00:27:00,870 --> 00:27:01,870 omitted here 722 00:27:03,420 --> 00:27:05,879 and some sand silicon 723 00:27:05,880 --> 00:27:07,229 carbide, actually. 724 00:27:07,230 --> 00:27:09,569 But that's yeah. 725 00:27:09,570 --> 00:27:11,729 We call it you you take the 726 00:27:11,730 --> 00:27:13,739 piece of glass, throw bits of sand in it, 727 00:27:13,740 --> 00:27:14,859 and then you have a telescope. 728 00:27:14,860 --> 00:27:16,919 That's that's how 729 00:27:16,920 --> 00:27:19,019 one guy put it once 730 00:27:20,040 --> 00:27:21,119 when we discussed it. 731 00:27:21,120 --> 00:27:23,549 Other at a astronomy 732 00:27:23,550 --> 00:27:25,919 meeting and polishing 733 00:27:25,920 --> 00:27:28,049 agent. That's most of the 734 00:27:28,050 --> 00:27:30,539 time. That's aluminum, um, 735 00:27:30,540 --> 00:27:33,119 not aluminum oxide. 736 00:27:33,120 --> 00:27:34,799 Really interesting chemistry going on 737 00:27:34,800 --> 00:27:36,959 there. And nobody really knows why. 738 00:27:36,960 --> 00:27:38,910 If somebody in the audience 739 00:27:39,990 --> 00:27:42,479 and that's me asking 740 00:27:42,480 --> 00:27:44,639 somebody for help knows 741 00:27:44,640 --> 00:27:47,099 how how Xerox 742 00:27:47,100 --> 00:27:49,319 it works, 743 00:27:49,320 --> 00:27:50,730 how it polishes glass 744 00:27:51,780 --> 00:27:54,149 come up, you're going to get the matter. 745 00:27:54,150 --> 00:27:56,369 Really, it's I really had a hard 746 00:27:56,370 --> 00:27:58,709 time to research that and pitch 747 00:27:59,730 --> 00:28:02,339 like the black thing pitch, not the tone 748 00:28:02,340 --> 00:28:03,269 one. 749 00:28:03,270 --> 00:28:05,459 So here we have 750 00:28:05,460 --> 00:28:07,709 our that's the mirror. 751 00:28:07,710 --> 00:28:08,710 That's the tool. 752 00:28:09,480 --> 00:28:11,549 Here we I illustrated two pieces of 753 00:28:11,550 --> 00:28:14,039 glass because I was I was lazy, 754 00:28:14,040 --> 00:28:15,479 pure laziness here. 755 00:28:15,480 --> 00:28:17,849 I'm what you do is 756 00:28:17,850 --> 00:28:19,469 you have those two mirrors in between. 757 00:28:19,470 --> 00:28:21,449 There's the sound, there's a piece of 758 00:28:21,450 --> 00:28:23,699 glass, there's the sound, the abrasive. 759 00:28:23,700 --> 00:28:26,369 And here you 760 00:28:26,370 --> 00:28:28,559 you you put pressure 761 00:28:28,560 --> 00:28:30,869 on it. So what happens 762 00:28:30,870 --> 00:28:33,539 in the center of the top part, 763 00:28:33,540 --> 00:28:35,789 you have higher pressure 764 00:28:35,790 --> 00:28:38,220 and on the edge of the bottom part. 765 00:28:39,320 --> 00:28:41,389 You have increased pressure, 766 00:28:41,390 --> 00:28:42,589 so 767 00:28:43,820 --> 00:28:46,159 hands up and I want 768 00:28:46,160 --> 00:28:48,289 you to participate in that, what 769 00:28:48,290 --> 00:28:50,599 will happen with the top 770 00:28:50,600 --> 00:28:51,600 part? 771 00:28:53,180 --> 00:28:54,180 Yes, 772 00:28:56,440 --> 00:28:58,550 you wrote the middle, you're going to get 773 00:28:59,600 --> 00:29:02,359 a hole in the hole in the middle. 774 00:29:02,360 --> 00:29:04,669 Oh, do you remember the slide from back 775 00:29:04,670 --> 00:29:05,690 there where 776 00:29:06,740 --> 00:29:08,959 we had that concave 777 00:29:08,960 --> 00:29:10,219 mirror? 778 00:29:10,220 --> 00:29:12,289 Well, that's what 779 00:29:12,290 --> 00:29:13,290 happens. 780 00:29:13,820 --> 00:29:14,820 You get the curvature. 781 00:29:15,890 --> 00:29:18,049 And if you do that, 782 00:29:18,050 --> 00:29:19,050 cortically. 783 00:29:20,450 --> 00:29:22,909 Enough so you 784 00:29:22,910 --> 00:29:25,070 turned the two parts count 785 00:29:26,090 --> 00:29:28,639 in in opposite directions 786 00:29:28,640 --> 00:29:30,979 randomly, like you make you make. 787 00:29:30,980 --> 00:29:32,359 Actually, I wanted to make a small 788 00:29:32,360 --> 00:29:33,619 demonstration here today, 789 00:29:34,640 --> 00:29:35,899 but guess what? 790 00:29:35,900 --> 00:29:37,999 That's where the demonstration is exactly 791 00:29:38,000 --> 00:29:40,819 at home. But it's absolute, absolute 792 00:29:40,820 --> 00:29:41,820 perfect use. 793 00:29:42,860 --> 00:29:45,019 So you rotated, you move 794 00:29:45,020 --> 00:29:46,999 it along, you make different lines to 795 00:29:47,000 --> 00:29:49,429 make you make you make overall 796 00:29:49,430 --> 00:29:51,499 the cultic movement and you end up 797 00:29:51,500 --> 00:29:52,609 with a sphere. 798 00:29:52,610 --> 00:29:54,829 So what do you do then 799 00:29:54,830 --> 00:29:56,929 is you measure a you 800 00:29:56,930 --> 00:29:59,479 measure how deep you are and, you know, 801 00:29:59,480 --> 00:30:01,999 the shape of the sphere you have. 802 00:30:02,000 --> 00:30:03,000 And 803 00:30:04,400 --> 00:30:06,289 if you get to a point where it is, 804 00:30:07,460 --> 00:30:09,469 what is the shape you want it? 805 00:30:09,470 --> 00:30:10,729 You refine it. 806 00:30:10,730 --> 00:30:12,799 First of all, with silicon, you start 807 00:30:12,800 --> 00:30:15,019 with 60 grand with granule 808 00:30:15,020 --> 00:30:16,079 size of 60. 809 00:30:16,080 --> 00:30:18,379 Oh, by the way, silicon carbide, 810 00:30:18,380 --> 00:30:20,359 you know, everybody knows it. 811 00:30:20,360 --> 00:30:22,460 It's this stuff glued on sandpaper 812 00:30:24,320 --> 00:30:27,139 and you go up to 320, 813 00:30:27,140 --> 00:30:29,440 um, um, 814 00:30:32,030 --> 00:30:34,189 granule size and then you go 815 00:30:34,190 --> 00:30:35,179 Telharmonium. 816 00:30:35,180 --> 00:30:38,029 That's that's a really fun fact. 817 00:30:38,030 --> 00:30:40,159 So I was traveling, I 818 00:30:40,160 --> 00:30:42,259 was traveling around in 819 00:30:42,260 --> 00:30:44,599 Munich taking that the 820 00:30:44,600 --> 00:30:46,910 plane taking the metro and 821 00:30:48,140 --> 00:30:50,359 well as chance will 822 00:30:50,360 --> 00:30:52,519 have it. I forgot my 823 00:30:52,520 --> 00:30:54,679 purse, my my wallet 824 00:30:54,680 --> 00:30:56,239 at home in the wallet. 825 00:30:56,240 --> 00:30:59,059 It was my student, my student 826 00:30:59,060 --> 00:30:59,989 ticket. 827 00:30:59,990 --> 00:31:02,539 So basically I 828 00:31:02,540 --> 00:31:04,069 got check. Of course, when you forget at 829 00:31:04,070 --> 00:31:06,139 home, they check you, they ask 830 00:31:06,140 --> 00:31:08,299 you what's your what's your 831 00:31:08,300 --> 00:31:10,579 ticket? And then you learn, never mind. 832 00:31:10,580 --> 00:31:12,679 So sometimes it 833 00:31:12,680 --> 00:31:14,869 happens that the police isn't as 834 00:31:14,870 --> 00:31:17,179 present. So imagine 835 00:31:17,180 --> 00:31:19,939 a police police officer 836 00:31:19,940 --> 00:31:21,889 or tell me what's in the backpack. 837 00:31:21,890 --> 00:31:23,569 They're actually allowed to do that. 838 00:31:23,570 --> 00:31:25,549 Um, what's in the backpack? 839 00:31:25,550 --> 00:31:26,539 Yeah, some. 840 00:31:26,540 --> 00:31:28,669 I just got my mirror and there is also 841 00:31:28,670 --> 00:31:31,729 some some polishing 842 00:31:31,730 --> 00:31:34,219 engines, silicon 843 00:31:34,220 --> 00:31:36,379 carbide, some aluminum oxide 844 00:31:36,380 --> 00:31:38,749 and whoever knows what 845 00:31:38,750 --> 00:31:40,229 color. 846 00:31:40,230 --> 00:31:41,460 Aluminum oxide is 847 00:31:43,920 --> 00:31:46,259 pure white, and then imagine that being 848 00:31:46,260 --> 00:31:48,419 a powder with the size 849 00:31:48,420 --> 00:31:50,189 of nine micrometers, 850 00:31:51,720 --> 00:31:53,790 that guy started asking questions. 851 00:31:55,530 --> 00:31:57,719 Thank God they had like a rapid test. 852 00:31:57,720 --> 00:31:59,459 And I told them, look, guys, it's you 853 00:31:59,460 --> 00:32:02,459 see, that's I said, that's that's the 854 00:32:02,460 --> 00:32:03,539 that's the 80 855 00:32:04,620 --> 00:32:06,059 granule size of Silicon covid. 856 00:32:06,060 --> 00:32:07,439 That's why it's black silicon. 857 00:32:07,440 --> 00:32:09,599 It has. And I explain and 858 00:32:09,600 --> 00:32:12,059 they believe me, but still 859 00:32:12,060 --> 00:32:14,130 it got complicated. 860 00:32:16,600 --> 00:32:17,600 Yeah. 861 00:32:20,930 --> 00:32:22,609 Sorry, I didn't understand 862 00:32:23,780 --> 00:32:24,780 what. 863 00:32:30,590 --> 00:32:32,929 I really, honestly 864 00:32:32,930 --> 00:32:34,670 don't hear what you're saying. 865 00:32:39,140 --> 00:32:40,140 Is the mike on? 866 00:32:41,210 --> 00:32:43,279 I just said, you can be very 867 00:32:43,280 --> 00:32:44,799 lucky that I didn't ask you for an 868 00:32:44,800 --> 00:32:46,999 biopsy, that you didn't have to try out 869 00:32:47,000 --> 00:32:48,649 a powder and put it into your body 870 00:32:48,650 --> 00:32:49,899 somewhere. 871 00:32:49,900 --> 00:32:52,639 Actually, yes, 872 00:32:52,640 --> 00:32:54,909 there's some research coming up about 873 00:32:54,910 --> 00:32:57,019 what aluminum does to your body. 874 00:32:57,020 --> 00:32:59,899 It basically screws up everything, but 875 00:32:59,900 --> 00:33:02,359 so don't inhale it. 876 00:33:02,360 --> 00:33:04,280 That's a bad idea. 877 00:33:05,350 --> 00:33:06,350 OK, 878 00:33:07,490 --> 00:33:10,159 so then you 879 00:33:10,160 --> 00:33:12,859 you with all the steps, 880 00:33:12,860 --> 00:33:13,939 you go find her. 881 00:33:13,940 --> 00:33:16,159 And finally you refine the surface, 882 00:33:16,160 --> 00:33:18,439 starting with with the 32 883 00:33:18,440 --> 00:33:21,169 micrometer aluminum oxide. 884 00:33:21,170 --> 00:33:23,509 You can already see 885 00:33:23,510 --> 00:33:26,209 if you look at the flat angle 886 00:33:26,210 --> 00:33:28,559 on the mirror, you can see 887 00:33:28,560 --> 00:33:31,099 the you can see it starts reflecting. 888 00:33:31,100 --> 00:33:33,039 That's where you get. Oh, yes, yes, yes. 889 00:33:33,040 --> 00:33:34,999 I'm close to having a mirror. 890 00:33:35,000 --> 00:33:36,000 No, you're not. 891 00:33:38,420 --> 00:33:40,480 Then the work comes in. 892 00:33:41,990 --> 00:33:44,209 This guy here who's putting the polishing 893 00:33:44,210 --> 00:33:46,069 angel on, that's that's the copyright 894 00:33:46,070 --> 00:33:47,479 holder stuff is Kefalas. 895 00:33:47,480 --> 00:33:49,729 That's the guy who's like 896 00:33:49,730 --> 00:33:52,609 the guru in Germany, in my eyes, 897 00:33:52,610 --> 00:33:54,739 my opinion. But he knows a lot 898 00:33:54,740 --> 00:33:56,839 about grinding mirrors and. 899 00:33:56,840 --> 00:33:58,039 Yeah, I know. I know. 900 00:33:58,040 --> 00:33:59,629 And I know he's watching. 901 00:33:59,630 --> 00:34:01,939 So, yeah, I know he's probably going 902 00:34:01,940 --> 00:34:03,739 read right now, but I don't care about 903 00:34:03,740 --> 00:34:05,839 that. So what you need 904 00:34:05,840 --> 00:34:08,839 is cerium oxide and pitch 905 00:34:08,840 --> 00:34:10,218 that black thing. 906 00:34:10,219 --> 00:34:12,799 You know why they call it pitch black. 907 00:34:12,800 --> 00:34:14,388 Well that you see. 908 00:34:14,389 --> 00:34:16,638 And this yellowish 909 00:34:16,639 --> 00:34:19,468 powder, which was also a funny thing, 910 00:34:19,469 --> 00:34:20,669 they wanted to test it. 911 00:34:20,670 --> 00:34:21,670 That too. 912 00:34:23,480 --> 00:34:25,609 You dissolved in water and you 913 00:34:25,610 --> 00:34:27,738 put it on the on the 914 00:34:27,739 --> 00:34:29,150 on the pitch and. 915 00:34:30,280 --> 00:34:32,529 You put really don't put a lot 916 00:34:32,530 --> 00:34:34,539 in it that that here is really, really 917 00:34:34,540 --> 00:34:35,759 just see how thin it is. 918 00:34:38,190 --> 00:34:40,709 You don't put a lot in it, but still 919 00:34:40,710 --> 00:34:42,899 the serum oxide kind of 920 00:34:42,900 --> 00:34:44,819 interacts chemically, chemically with the 921 00:34:44,820 --> 00:34:45,749 glass. 922 00:34:45,750 --> 00:34:47,999 Then again, it bet's a bet 923 00:34:48,000 --> 00:34:50,189 itself in the pitch 924 00:34:50,190 --> 00:34:52,589 and kind of like 925 00:34:52,590 --> 00:34:54,718 like millions and millions 926 00:34:54,719 --> 00:34:57,089 of razors cut the glass 927 00:34:57,090 --> 00:34:59,989 away and polishes, polishes, 928 00:34:59,990 --> 00:35:01,260 polishes it away and 929 00:35:02,490 --> 00:35:04,139 kind of smears it also. 930 00:35:04,140 --> 00:35:06,539 There is something I found 931 00:35:06,540 --> 00:35:08,609 a paper with some Chinese researchers 932 00:35:08,610 --> 00:35:09,610 which. 933 00:35:11,170 --> 00:35:13,479 I dare not I don't know, 934 00:35:13,480 --> 00:35:15,579 I know a lot about that stuff, 935 00:35:15,580 --> 00:35:17,979 but I don't actually believe it, 936 00:35:17,980 --> 00:35:20,020 that there is also some thermal 937 00:35:21,640 --> 00:35:23,589 some thermal process going on, hitting 938 00:35:23,590 --> 00:35:25,869 the glass up and smearing it the way 939 00:35:25,870 --> 00:35:28,210 I honestly have no idea. 940 00:35:29,650 --> 00:35:31,749 Those Chinese guys wrote a paper I don't 941 00:35:31,750 --> 00:35:33,789 believe have more critical credibility 942 00:35:33,790 --> 00:35:35,349 than me and that matter. 943 00:35:35,350 --> 00:35:36,350 So 944 00:35:37,690 --> 00:35:39,789 that you need to test it or the 945 00:35:39,790 --> 00:35:40,989 process is 946 00:35:43,330 --> 00:35:44,319 very precious. 947 00:35:44,320 --> 00:35:46,149 You do something, you see what this 948 00:35:46,150 --> 00:35:48,099 something does, and then you look again 949 00:35:48,100 --> 00:35:49,569 and you see what this something does 950 00:35:49,570 --> 00:35:50,949 again and so on and so on. 951 00:35:52,120 --> 00:35:54,309 First of all, you want to find out how 952 00:35:54,310 --> 00:35:55,539 deep is the mirror? 953 00:35:55,540 --> 00:35:58,059 What is the shape of mosfet? 954 00:35:58,060 --> 00:35:59,349 That's how you do it. 955 00:35:59,350 --> 00:36:01,719 You take a ruler and 956 00:36:01,720 --> 00:36:04,119 measure that distance 957 00:36:04,120 --> 00:36:05,679 fairly easy, isn't it? 958 00:36:05,680 --> 00:36:06,989 No hightech involved here. 959 00:36:08,680 --> 00:36:11,379 The more high tech way, 960 00:36:11,380 --> 00:36:12,670 high tech, whatever, 961 00:36:14,380 --> 00:36:16,840 high tech in terms of the 17th century, 962 00:36:18,880 --> 00:36:20,320 as you take a torch, 963 00:36:21,610 --> 00:36:23,709 you make them real wet. 964 00:36:23,710 --> 00:36:25,599 You take a torch and you look with a 965 00:36:25,600 --> 00:36:27,699 reflection goes, and if you hit the right 966 00:36:27,700 --> 00:36:29,709 spot, you will know that if you hit it, 967 00:36:29,710 --> 00:36:32,169 believe me, you 968 00:36:32,170 --> 00:36:34,719 measure the distance and you have 969 00:36:34,720 --> 00:36:37,179 the right of the radius of the sphere 970 00:36:37,180 --> 00:36:39,729 that this that the surface 971 00:36:39,730 --> 00:36:40,730 is an element of. 972 00:36:41,800 --> 00:36:42,779 Sounds complicated. 973 00:36:42,780 --> 00:36:44,049 It isn't. 974 00:36:44,050 --> 00:36:46,509 It's really basic geometry 975 00:36:46,510 --> 00:36:47,800 because a 976 00:36:49,060 --> 00:36:51,519 spherical mirror will reflect everything 977 00:36:51,520 --> 00:36:53,439 that comes from the center back to the 978 00:36:53,440 --> 00:36:54,369 center. 979 00:36:54,370 --> 00:36:57,129 That's what we use 980 00:36:57,130 --> 00:36:59,409 to make the testing with 981 00:36:59,410 --> 00:37:01,590 IFFCO, with the testing 982 00:37:03,040 --> 00:37:05,469 little for you. 983 00:37:05,470 --> 00:37:07,599 Probably most people know of the 984 00:37:07,600 --> 00:37:09,669 pendulum, but this is also 985 00:37:09,670 --> 00:37:11,919 an ingenious method of 986 00:37:11,920 --> 00:37:14,799 making high precision measurements 987 00:37:14,800 --> 00:37:17,529 on mirrors and reflecting 988 00:37:17,530 --> 00:37:20,019 surfaces in general with 989 00:37:20,020 --> 00:37:21,020 minimum. 990 00:37:22,920 --> 00:37:25,829 Monetary involvement, you 991 00:37:25,830 --> 00:37:28,689 are talking to make it for Cortazar, 992 00:37:28,690 --> 00:37:30,749 we're talking if you if you 993 00:37:30,750 --> 00:37:33,749 really if you are going to go fancy, 994 00:37:33,750 --> 00:37:35,819 really fancy, we're talking 50 euros a 995 00:37:35,820 --> 00:37:36,839 year. 996 00:37:36,840 --> 00:37:39,119 You can make it actually for free. 997 00:37:39,120 --> 00:37:41,219 If you if 998 00:37:41,220 --> 00:37:43,289 you go to scrap yard or something 999 00:37:43,290 --> 00:37:45,899 like that, you it's 1000 00:37:45,900 --> 00:37:47,939 really you can make it really cheap and 1001 00:37:47,940 --> 00:37:49,409 it's really precise. 1002 00:37:49,410 --> 00:37:51,989 It's surprisingly precise. 1003 00:37:51,990 --> 00:37:54,089 And then again, Interferometry, 1004 00:37:54,090 --> 00:37:55,859 that's like the more techie way 1005 00:37:57,210 --> 00:37:59,279 I want Luminita from here I 1006 00:37:59,280 --> 00:38:02,179 could make a talk on interferometry alone 1007 00:38:02,180 --> 00:38:04,079 or different medical testing of MRIs, 1008 00:38:04,080 --> 00:38:06,029 because you have to you have to take into 1009 00:38:06,030 --> 00:38:08,189 account so many effects 1010 00:38:08,190 --> 00:38:10,289 that I'd simply say that's 1011 00:38:10,290 --> 00:38:13,499 nothing for the beginner. 1012 00:38:13,500 --> 00:38:15,599 But if you go 1013 00:38:15,600 --> 00:38:17,909 there's a lot of a lot of information 1014 00:38:17,910 --> 00:38:19,029 on that to read up. 1015 00:38:19,030 --> 00:38:20,789 So Google it. 1016 00:38:20,790 --> 00:38:22,469 You will be more than happy 1017 00:38:23,550 --> 00:38:25,319 with information you got. 1018 00:38:25,320 --> 00:38:27,509 Get that. So here 1019 00:38:27,510 --> 00:38:28,679 we have a coat tester 1020 00:38:30,180 --> 00:38:31,079 on the bottom. 1021 00:38:31,080 --> 00:38:32,090 You see the light source 1022 00:38:33,300 --> 00:38:35,009 shining onto a mirror, projecting the 1023 00:38:35,010 --> 00:38:37,409 light on your on your test 1024 00:38:37,410 --> 00:38:38,909 subject. 1025 00:38:38,910 --> 00:38:41,159 And here you 1026 00:38:41,160 --> 00:38:43,259 have an edge, a knife 1027 00:38:43,260 --> 00:38:45,659 edge. That's why it's called also 1028 00:38:45,660 --> 00:38:48,149 for cold knife edge testing. 1029 00:38:48,150 --> 00:38:50,219 And here what you can see 1030 00:38:50,220 --> 00:38:52,769 illuminated is so basically 1031 00:38:52,770 --> 00:38:54,839 what's what's the what's the thought 1032 00:38:54,840 --> 00:38:57,509 behind this here? 1033 00:38:57,510 --> 00:38:59,339 So here we are roughly in the center of 1034 00:38:59,340 --> 00:39:00,959 the mirror. We are talking here. 1035 00:39:00,960 --> 00:39:03,239 The dimensions of scale are scaled down 1036 00:39:03,240 --> 00:39:03,869 in order. 1037 00:39:03,870 --> 00:39:06,569 That's a Wikipedia picture 1038 00:39:06,570 --> 00:39:07,710 in order for it to be 1039 00:39:10,080 --> 00:39:12,209 for you to be able to understand it. 1040 00:39:12,210 --> 00:39:14,639 But that that size, 1041 00:39:14,640 --> 00:39:16,739 if you if compared to the human eye 1042 00:39:16,740 --> 00:39:19,109 that a mirror would be 1043 00:39:19,110 --> 00:39:21,419 there, that would be a typical focal 1044 00:39:21,420 --> 00:39:23,279 distance for that one. 1045 00:39:23,280 --> 00:39:25,619 So we are so 1046 00:39:25,620 --> 00:39:27,469 here we are roughly in the center. 1047 00:39:29,130 --> 00:39:30,719 So what you 1048 00:39:32,520 --> 00:39:34,739 do is, you know, 1049 00:39:34,740 --> 00:39:36,779 OK, if I project something from the 1050 00:39:36,780 --> 00:39:39,179 center on the mirror, it goes 1051 00:39:39,180 --> 00:39:41,399 back to the center on 1052 00:39:41,400 --> 00:39:43,109 a single point. 1053 00:39:43,110 --> 00:39:45,239 So if I put a knife edge there, 1054 00:39:45,240 --> 00:39:48,059 a really, really sharp edge 1055 00:39:48,060 --> 00:39:50,789 which blocks or which 1056 00:39:50,790 --> 00:39:53,129 is which binary blocks 1057 00:39:53,130 --> 00:39:55,080 or allows light to pass through. 1058 00:39:56,240 --> 00:39:58,639 I if I had a perfect 1059 00:39:58,640 --> 00:40:01,189 sphere, a perfect set up, theoretically, 1060 00:40:01,190 --> 00:40:03,439 I would get I 1061 00:40:03,440 --> 00:40:05,659 would see that the mirror and all 1062 00:40:05,660 --> 00:40:08,339 the test subject illuminated. 1063 00:40:08,340 --> 00:40:10,469 And then it goes black as 1064 00:40:10,470 --> 00:40:12,749 I move, as I move the edge back 1065 00:40:12,750 --> 00:40:13,750 and forth. 1066 00:40:14,910 --> 00:40:17,249 Well, reality kicks 1067 00:40:17,250 --> 00:40:20,219 in and you 1068 00:40:20,220 --> 00:40:22,289 get deviations from 1069 00:40:22,290 --> 00:40:23,789 the sphere. 1070 00:40:23,790 --> 00:40:25,859 So here, that's more or less 1071 00:40:25,860 --> 00:40:27,449 a good thing. 1072 00:40:27,450 --> 00:40:29,729 Here you can see you can only see here. 1073 00:40:29,730 --> 00:40:31,859 There is there's a you 1074 00:40:31,860 --> 00:40:34,409 have kind of something funny 1075 00:40:34,410 --> 00:40:36,719 going on here on the edge 1076 00:40:36,720 --> 00:40:37,619 here or something. 1077 00:40:37,620 --> 00:40:39,749 There is a kind of a mountain 1078 00:40:39,750 --> 00:40:41,699 and the center here, smaller mountain, 1079 00:40:41,700 --> 00:40:44,429 combined with a with the with a 1080 00:40:44,430 --> 00:40:45,359 ruined edge. 1081 00:40:45,360 --> 00:40:47,579 I'd say here 1082 00:40:47,580 --> 00:40:49,859 you see some shading. 1083 00:40:49,860 --> 00:40:52,619 Here you see a pit in the middle. 1084 00:40:52,620 --> 00:40:54,869 And again, this, this edge, 1085 00:40:54,870 --> 00:40:57,209 this is there's a typical 1086 00:40:57,210 --> 00:40:59,939 error beginning to make 1087 00:40:59,940 --> 00:41:00,719 nothing you can't. 1088 00:41:00,720 --> 00:41:03,119 Correct. But yeah. 1089 00:41:03,120 --> 00:41:05,489 So this is what you would see. 1090 00:41:05,490 --> 00:41:08,099 And you see here this deviations 1091 00:41:08,100 --> 00:41:10,619 from the sphere are 1092 00:41:10,620 --> 00:41:13,349 we're talking about maybe 1093 00:41:13,350 --> 00:41:15,119 here it's huge. 1094 00:41:15,120 --> 00:41:17,760 We're talking about 200 nanometers. 1095 00:41:19,890 --> 00:41:20,890 NanoMETERS. 1096 00:41:23,910 --> 00:41:26,279 Um, excuse 1097 00:41:26,280 --> 00:41:27,280 me. 1098 00:41:28,700 --> 00:41:31,489 Um, 20 wavelengths, 1099 00:41:31,490 --> 00:41:33,829 sorry, 20 lamda 1100 00:41:33,830 --> 00:41:35,059 20, I'm sorry. 1101 00:41:35,060 --> 00:41:37,309 Yeah, so this is 20 where Flash 1102 00:41:37,310 --> 00:41:39,469 and as a matter what 1103 00:41:39,470 --> 00:41:41,629 you would use as wavelength, typically 1104 00:41:41,630 --> 00:41:43,849 white light. So you would use that 1105 00:41:43,850 --> 00:41:44,779 20 times. 1106 00:41:44,780 --> 00:41:46,789 Four hundred nanometers. 1107 00:41:46,790 --> 00:41:48,229 That's a deviation here. 1108 00:41:48,230 --> 00:41:51,079 We're talking about precise testing. 1109 00:41:51,080 --> 00:41:53,299 Um, actually, I don't 1110 00:41:53,300 --> 00:41:56,179 know if I do have the picture 1111 00:41:56,180 --> 00:41:58,309 where you have that 1112 00:41:58,310 --> 00:41:59,419 for Colthurst. 1113 00:41:59,420 --> 00:42:01,939 And somebody puts a hand in the 1114 00:42:01,940 --> 00:42:04,039 in the in the 1115 00:42:04,040 --> 00:42:06,529 in the beam, you can actually 1116 00:42:06,530 --> 00:42:09,139 see the thermal, 1117 00:42:09,140 --> 00:42:11,270 the thermal turbulences of the hand. 1118 00:42:12,970 --> 00:42:15,039 So you can 1119 00:42:15,040 --> 00:42:17,409 imagine what the what the 1120 00:42:17,410 --> 00:42:19,239 what the resolution here is, it's really, 1121 00:42:19,240 --> 00:42:20,499 really good. 1122 00:42:20,500 --> 00:42:23,469 And yeah, Interferometer, 1123 00:42:23,470 --> 00:42:25,209 this is basically for you to have 1124 00:42:25,210 --> 00:42:27,039 something to Google. 1125 00:42:27,040 --> 00:42:29,439 Those are fermenters which work 1126 00:42:29,440 --> 00:42:30,440 with 1127 00:42:31,840 --> 00:42:34,029 which amateurs have built a common path 1128 00:42:34,030 --> 00:42:35,889 into fermenters. They are not that 1129 00:42:35,890 --> 00:42:37,959 precise, but they have an advantage 1130 00:42:37,960 --> 00:42:39,489 in in construction. 1131 00:42:39,490 --> 00:42:41,619 So that's basically for you. 1132 00:42:41,620 --> 00:42:43,989 If you want to look it up, that's what 1133 00:42:43,990 --> 00:42:45,459 you would Google for boffing for 1134 00:42:45,460 --> 00:42:47,589 Interferometer Potente diffraction 1135 00:42:47,590 --> 00:42:49,839 deferment at the physio, which 1136 00:42:49,840 --> 00:42:52,029 is a also pointy fraction different, 1137 00:42:52,030 --> 00:42:54,109 but with a special setup. 1138 00:42:54,110 --> 00:42:56,259 Again, I could I 1139 00:42:56,260 --> 00:42:57,260 could go on. 1140 00:42:59,590 --> 00:43:02,139 I didn't exactly lie to you, 1141 00:43:02,140 --> 00:43:04,419 but I didn't 1142 00:43:04,420 --> 00:43:05,420 tell the whole truth. 1143 00:43:06,610 --> 00:43:08,679 This fear does 1144 00:43:08,680 --> 00:43:09,680 not. 1145 00:43:11,770 --> 00:43:14,019 Provide a perfect image if you have 1146 00:43:14,020 --> 00:43:16,659 light coming from the from infinity. 1147 00:43:17,740 --> 00:43:19,779 Here we have an illustration. 1148 00:43:19,780 --> 00:43:21,819 If you have light coming from from 1149 00:43:21,820 --> 00:43:24,579 infinity here, parallel beams. 1150 00:43:24,580 --> 00:43:26,290 You, uh, that. 1151 00:43:27,860 --> 00:43:29,750 Always helps shaking up batteries. 1152 00:43:31,220 --> 00:43:34,429 So here you see that's that's the focal 1153 00:43:34,430 --> 00:43:37,579 region that's called spherical 1154 00:43:37,580 --> 00:43:39,139 aberration. 1155 00:43:39,140 --> 00:43:41,779 You have it always with with 1156 00:43:41,780 --> 00:43:44,149 with spherical, with spherical 1157 00:43:44,150 --> 00:43:45,529 optical elements. 1158 00:43:45,530 --> 00:43:48,199 They kind of have a hard time 1159 00:43:48,200 --> 00:43:50,779 focusing like from from infinity 1160 00:43:50,780 --> 00:43:53,749 onto one point and correcting 1161 00:43:53,750 --> 00:43:55,879 and correcting this fairly 1162 00:43:55,880 --> 00:43:56,719 easy. 1163 00:43:56,720 --> 00:43:59,029 You just make it take your sphere. 1164 00:43:59,030 --> 00:44:01,399 This is a bit exaggerated, 1165 00:44:01,400 --> 00:44:03,859 but you take a sphere and make 1166 00:44:03,860 --> 00:44:04,860 a little. 1167 00:44:05,790 --> 00:44:06,900 A dimple in the middle 1168 00:44:08,130 --> 00:44:10,109 and you end up with a parabola and a 1169 00:44:10,110 --> 00:44:11,849 parabola focuses all the light on one 1170 00:44:11,850 --> 00:44:13,290 point coming from infinity. 1171 00:44:14,760 --> 00:44:17,159 Again, this is really, 1172 00:44:17,160 --> 00:44:18,390 really exaggerated. 1173 00:44:21,130 --> 00:44:23,469 Car lights use 1174 00:44:23,470 --> 00:44:25,689 that inverse path, you have 1175 00:44:25,690 --> 00:44:27,879 the the light bulb here 1176 00:44:27,880 --> 00:44:29,710 and you get a parallel path that 1177 00:44:32,590 --> 00:44:34,869 parabolic antennas, guess 1178 00:44:34,870 --> 00:44:36,339 where they got the name from. 1179 00:44:36,340 --> 00:44:38,799 So testing that 1180 00:44:38,800 --> 00:44:40,929 is kind of big a 1181 00:44:40,930 --> 00:44:43,149 challenge because you don't 1182 00:44:43,150 --> 00:44:45,159 test the whole mirror as a whole and you 1183 00:44:45,160 --> 00:44:47,369 only know how to test spheres. 1184 00:44:48,670 --> 00:44:50,829 So what we do is we make 1185 00:44:50,830 --> 00:44:53,259 we cover up some areas there. 1186 00:44:53,260 --> 00:44:55,719 It's called a it's called a, 1187 00:44:55,720 --> 00:44:58,059 uh, it's 1188 00:44:58,060 --> 00:44:59,379 called a mask. 1189 00:44:59,380 --> 00:45:01,569 You have black paper and you cut 1190 00:45:01,570 --> 00:45:02,619 holes in it. 1191 00:45:02,620 --> 00:45:05,229 So what you do is you approximate 1192 00:45:05,230 --> 00:45:07,599 that parabola with a lot 1193 00:45:07,600 --> 00:45:09,819 and lots and lots of 1194 00:45:09,820 --> 00:45:11,829 depending on how many you want for a 1195 00:45:11,830 --> 00:45:13,899 small mirror, three regions for a 1196 00:45:13,900 --> 00:45:15,849 big one, you would use up to eight, up to 1197 00:45:15,850 --> 00:45:16,749 10, 12. 1198 00:45:16,750 --> 00:45:18,009 I've seen one with 14. 1199 00:45:18,010 --> 00:45:19,479 That's just insane. 1200 00:45:19,480 --> 00:45:21,609 So you approximate the 1201 00:45:21,610 --> 00:45:23,529 mirror with zones. 1202 00:45:23,530 --> 00:45:25,659 You assume that you 1203 00:45:25,660 --> 00:45:27,879 have a steady 1204 00:45:27,880 --> 00:45:29,709 you have a steady curve. 1205 00:45:29,710 --> 00:45:32,229 You don't you don't make funny stuff 1206 00:45:32,230 --> 00:45:34,449 between the between the regions. 1207 00:45:34,450 --> 00:45:36,399 So what you do is you measure a lot of 1208 00:45:36,400 --> 00:45:37,789 spheres. And if the relations of the 1209 00:45:37,790 --> 00:45:40,519 first to each other is correct, 1210 00:45:40,520 --> 00:45:41,749 everything works fine. 1211 00:45:41,750 --> 00:45:43,689 There's also software where you can 1212 00:45:43,690 --> 00:45:45,969 calculate what the relation has to be, 1213 00:45:45,970 --> 00:45:47,829 which fits everything and stuff like 1214 00:45:47,830 --> 00:45:50,109 that. You can do that in an Excel sheet 1215 00:45:50,110 --> 00:45:52,419 or LibreOffice 1216 00:45:52,420 --> 00:45:54,699 calc sheet or whatever you 1217 00:45:54,700 --> 00:45:56,589 you want. You can do that. 1218 00:45:56,590 --> 00:45:59,019 There's a lot of software and if you 1219 00:45:59,020 --> 00:46:01,059 search for four core interferometry, you 1220 00:46:01,060 --> 00:46:03,359 will stumble upon those those, 1221 00:46:03,360 --> 00:46:05,559 uh, those 1222 00:46:05,560 --> 00:46:06,519 piece of software. 1223 00:46:06,520 --> 00:46:08,619 Most of it runs and runs on 1224 00:46:08,620 --> 00:46:10,989 Windows. But why works just 1225 00:46:10,990 --> 00:46:11,990 fine. 1226 00:46:12,400 --> 00:46:13,400 So 1227 00:46:14,560 --> 00:46:16,899 this is the grinding part, 1228 00:46:16,900 --> 00:46:19,209 making the mirror for 1229 00:46:19,210 --> 00:46:22,059 a eight inch, 200 millimeters, 1230 00:46:22,060 --> 00:46:24,309 eight inch or 200 millimeter a 1231 00:46:24,310 --> 00:46:26,769 mirror we would 1232 00:46:26,770 --> 00:46:28,329 calculate, if you are good, 1233 00:46:29,530 --> 00:46:31,899 90 hours of grinding, 1234 00:46:31,900 --> 00:46:33,699 polishing and everything included and 1235 00:46:33,700 --> 00:46:36,039 testing if you 1236 00:46:37,090 --> 00:46:38,139 are average. 1237 00:46:38,140 --> 00:46:40,329 We are talking rather about one hundred 1238 00:46:40,330 --> 00:46:41,919 and thirty to one hundred and fifty 1239 00:46:41,920 --> 00:46:42,920 hours. 1240 00:46:44,490 --> 00:46:45,540 The biggest part 1241 00:46:47,010 --> 00:46:49,259 is building the telescope, first 1242 00:46:49,260 --> 00:46:51,719 of all, you have to decide 1243 00:46:51,720 --> 00:46:53,309 what do I want? 1244 00:46:53,310 --> 00:46:55,339 Do I want a telescope which I want to 1245 00:46:55,340 --> 00:46:57,449 perfectly possible with an eight inch to 1246 00:46:57,450 --> 00:46:59,659 take it with you on the airplane luggage? 1247 00:47:00,970 --> 00:47:03,179 I don't know if the TSA likes it because 1248 00:47:03,180 --> 00:47:05,939 they know, but 1249 00:47:05,940 --> 00:47:08,009 that's I know people who take their 1250 00:47:08,010 --> 00:47:10,199 telescope on the plane as hand 1251 00:47:10,200 --> 00:47:11,200 luggage. 1252 00:47:11,790 --> 00:47:13,769 Maybe you want to what? 1253 00:47:13,770 --> 00:47:14,999 I had the problem. 1254 00:47:15,000 --> 00:47:16,859 I needed public transport. 1255 00:47:16,860 --> 00:47:19,019 I didn't have a car directly, 1256 00:47:19,020 --> 00:47:21,329 so I needed to carry that telescope 1257 00:47:21,330 --> 00:47:22,739 with me on public transport. 1258 00:47:22,740 --> 00:47:25,469 So I bought one 1259 00:47:25,470 --> 00:47:27,569 blame on me. But yeah, I bought a small 1260 00:47:27,570 --> 00:47:29,729 telescope, have that in my backpack, 1261 00:47:29,730 --> 00:47:31,919 have a tripod in my hand and 1262 00:47:31,920 --> 00:47:33,269 the eyepiece, 1263 00:47:34,320 --> 00:47:36,479 the eyepieces on the other hand. 1264 00:47:36,480 --> 00:47:38,699 And I just can go ahead, 1265 00:47:38,700 --> 00:47:41,549 people can take me with with them 1266 00:47:41,550 --> 00:47:42,639 in the car or whatever. 1267 00:47:42,640 --> 00:47:44,279 So it's not hard for them. 1268 00:47:44,280 --> 00:47:46,499 It's not easy for them, for 1269 00:47:46,500 --> 00:47:48,809 them to say no and just say, OK, 1270 00:47:48,810 --> 00:47:51,509 I don't want to I 1271 00:47:51,510 --> 00:47:52,679 don't have a room or whatever. 1272 00:47:52,680 --> 00:47:54,899 It's I it was really, 1273 00:47:54,900 --> 00:47:56,009 really compact. 1274 00:47:56,010 --> 00:47:58,079 And people are even going for a hike 1275 00:47:58,080 --> 00:47:59,849 with their telescope. 1276 00:47:59,850 --> 00:48:02,339 So we are talking about really, 1277 00:48:02,340 --> 00:48:04,769 really light, lightweight and compact 1278 00:48:04,770 --> 00:48:07,019 compact stuff. 1279 00:48:07,020 --> 00:48:08,369 Yeah, but 1280 00:48:10,260 --> 00:48:12,149 if you want to observe from your 1281 00:48:12,150 --> 00:48:14,309 backyard, there's no 1282 00:48:14,310 --> 00:48:17,369 there's no need there's no point 1283 00:48:17,370 --> 00:48:19,139 in investing all the time. 1284 00:48:19,140 --> 00:48:20,489 And the money and the complicated 1285 00:48:20,490 --> 00:48:22,619 constructions and the many failures 1286 00:48:22,620 --> 00:48:24,719 or whatever, you just build a 1287 00:48:24,720 --> 00:48:26,729 telescope that works and you don't care 1288 00:48:26,730 --> 00:48:28,379 how heavy it is. 1289 00:48:28,380 --> 00:48:29,969 You would you put a 1290 00:48:31,050 --> 00:48:33,509 a plastic sock on it 1291 00:48:33,510 --> 00:48:35,339 and it's protected from rain and 1292 00:48:35,340 --> 00:48:37,439 everything. It's just there. 1293 00:48:37,440 --> 00:48:39,209 If you want to take pictures with it, 1294 00:48:39,210 --> 00:48:40,949 there are different demands. 1295 00:48:40,950 --> 00:48:43,409 So you have to decide, 1296 00:48:43,410 --> 00:48:44,699 what do I want here? 1297 00:48:44,700 --> 00:48:46,289 What do I want to build? 1298 00:48:46,290 --> 00:48:47,789 So let's start 1299 00:48:48,930 --> 00:48:51,149 with what are the main 1300 00:48:51,150 --> 00:48:53,909 factors I mentioned transportability. 1301 00:48:55,110 --> 00:48:57,329 Handling the 1302 00:48:57,330 --> 00:48:59,549 best telescope is of no use if you can't 1303 00:48:59,550 --> 00:49:00,550 use it. 1304 00:49:01,790 --> 00:49:03,979 That's a tautology anyway, 1305 00:49:03,980 --> 00:49:04,980 and. 1306 00:49:06,200 --> 00:49:08,659 You wanted to be rigid, you don't 1307 00:49:08,660 --> 00:49:11,029 want to invest tons 1308 00:49:11,030 --> 00:49:14,059 of hours and your optics 1309 00:49:14,060 --> 00:49:16,249 and make everything 1310 00:49:16,250 --> 00:49:18,469 perfect and then everything 1311 00:49:18,470 --> 00:49:20,539 being sloppy and shaking 1312 00:49:20,540 --> 00:49:22,789 around, because 1313 00:49:22,790 --> 00:49:24,079 that's the main reason. 1314 00:49:24,080 --> 00:49:26,059 Do you remember those cheap telescopes I 1315 00:49:26,060 --> 00:49:27,319 told you about? 1316 00:49:27,320 --> 00:49:29,569 Don't buy too cheap 1317 00:49:29,570 --> 00:49:32,329 telescopes for kids because 1318 00:49:32,330 --> 00:49:34,999 they have sloppy mechanics 1319 00:49:35,000 --> 00:49:37,609 and they are no fun to use. 1320 00:49:37,610 --> 00:49:39,499 And if it's no fun to use, you won't use 1321 00:49:39,500 --> 00:49:40,999 it. And if you don't and if you want to 1322 00:49:41,000 --> 00:49:43,099 use it, then don't start in the first 1323 00:49:43,100 --> 00:49:44,299 place. 1324 00:49:44,300 --> 00:49:46,699 So that's those are really 1325 00:49:46,700 --> 00:49:48,109 important factors. 1326 00:49:48,110 --> 00:49:50,599 And especially the transportability is 1327 00:49:50,600 --> 00:49:52,699 is, I think, also your 1328 00:49:52,700 --> 00:49:53,700 budget. 1329 00:49:55,190 --> 00:49:57,139 If you have no budget and if you have no 1330 00:49:57,140 --> 00:49:59,299 car, there's no point 1331 00:49:59,300 --> 00:50:01,189 in making a one meter telescope. 1332 00:50:01,190 --> 00:50:02,689 We are talking about five thousand euros 1333 00:50:02,690 --> 00:50:04,309 only for the mirror. 1334 00:50:04,310 --> 00:50:05,899 And if you 1335 00:50:07,430 --> 00:50:09,589 if you are not careful and 1336 00:50:09,590 --> 00:50:11,179 that guy in the stream watching right 1337 00:50:11,180 --> 00:50:13,339 now, he knows what I'm 1338 00:50:13,340 --> 00:50:14,269 talking about. 1339 00:50:14,270 --> 00:50:16,089 He made an effort. 1340 00:50:16,090 --> 00:50:19,309 You can have a you maybe you ruined 1341 00:50:19,310 --> 00:50:21,859 four hundred euros worth of glass. 1342 00:50:24,170 --> 00:50:25,759 He was nearly done. 1343 00:50:25,760 --> 00:50:27,049 It was nearly done. He was doing his 1344 00:50:27,050 --> 00:50:28,849 final test. 1345 00:50:28,850 --> 00:50:31,009 Had he still had his mirror 1346 00:50:31,010 --> 00:50:32,010 on the bench 1347 00:50:33,080 --> 00:50:35,300 and his kids were in the house. 1348 00:50:37,430 --> 00:50:39,519 He was eager to finish it, 1349 00:50:39,520 --> 00:50:41,139 one of the kids opened the door. 1350 00:50:43,940 --> 00:50:46,759 I went, went through the house, 1351 00:50:46,760 --> 00:50:49,189 kicked the mirror off 1352 00:50:49,190 --> 00:50:51,379 of the stand, and you had 1353 00:50:51,380 --> 00:50:53,539 three really, really 1354 00:50:53,540 --> 00:50:55,010 well polished chaat. 1355 00:50:57,000 --> 00:50:58,000 And 1356 00:50:59,100 --> 00:51:01,230 that hurts another guy. 1357 00:51:03,000 --> 00:51:05,729 The stuff has gotten those pictures from. 1358 00:51:05,730 --> 00:51:06,389 Thanks for that. 1359 00:51:06,390 --> 00:51:07,390 By the way, 1360 00:51:09,000 --> 00:51:10,000 in order to avoid that, 1361 00:51:11,160 --> 00:51:13,259 he put his foot under 1362 00:51:13,260 --> 00:51:15,659 the mirror to catch it. 1363 00:51:15,660 --> 00:51:17,189 He had a broken foot. 1364 00:51:17,190 --> 00:51:19,319 The mirror was once OK. 1365 00:51:19,320 --> 00:51:20,699 He said it was worth it. 1366 00:51:22,350 --> 00:51:24,989 Imagine, imagine. 1367 00:51:24,990 --> 00:51:27,419 So. Yes, we are. 1368 00:51:27,420 --> 00:51:28,709 Be careful with it. 1369 00:51:28,710 --> 00:51:30,059 And. 1370 00:51:30,060 --> 00:51:32,129 Calculate a 1371 00:51:32,130 --> 00:51:33,959 failure shouldn't ruin your budget 1372 00:51:33,960 --> 00:51:35,430 planning for the next holiday. 1373 00:51:37,710 --> 00:51:38,989 So basically, 1374 00:51:40,440 --> 00:51:42,449 one thing you have also to decide is how 1375 00:51:42,450 --> 00:51:44,399 do I want to mount here? 1376 00:51:44,400 --> 00:51:47,159 This is an out of azimuth Mt. 1377 00:51:47,160 --> 00:51:48,480 shortened up days. 1378 00:51:49,500 --> 00:51:52,349 So you see, it's easy 1379 00:51:52,350 --> 00:51:54,269 up and down, left, right. 1380 00:51:54,270 --> 00:51:56,379 You have to access perpendicular 1381 00:51:56,380 --> 00:51:59,309 to the perpendicular to gravity. 1382 00:51:59,310 --> 00:52:01,229 Perfectly fine. Engineering, no 1383 00:52:01,230 --> 00:52:02,230 challenge. 1384 00:52:03,530 --> 00:52:05,339 Here we have a German mount. 1385 00:52:05,340 --> 00:52:07,349 The reason you would do that is you want 1386 00:52:07,350 --> 00:52:09,479 to take pictures so 1387 00:52:09,480 --> 00:52:12,239 the Earth's axis is tilted. 1388 00:52:12,240 --> 00:52:14,549 And what they do here is you 1389 00:52:14,550 --> 00:52:16,889 have one axis parallel to the other, 1390 00:52:16,890 --> 00:52:18,960 the Earth's axis, and you 1391 00:52:21,660 --> 00:52:23,759 counteract the movement of the earth 1392 00:52:23,760 --> 00:52:25,889 of the stars relative to the earth, of 1393 00:52:25,890 --> 00:52:28,079 course, and you just 1394 00:52:28,080 --> 00:52:29,669 move your telescope along. 1395 00:52:29,670 --> 00:52:31,859 So you just 1396 00:52:31,860 --> 00:52:34,769 have to worry about one axis 1397 00:52:34,770 --> 00:52:36,209 being properly. 1398 00:52:37,920 --> 00:52:39,749 That's a huge advantage. 1399 00:52:39,750 --> 00:52:42,249 Trust me on that, you have one even. 1400 00:52:42,250 --> 00:52:44,489 There are clockwork like. 1401 00:52:45,880 --> 00:52:48,519 This clockwork old 1402 00:52:48,520 --> 00:52:51,579 Russian clockwork mount's, 1403 00:52:51,580 --> 00:52:54,429 which worked marvelously. 1404 00:52:54,430 --> 00:52:56,739 They are great, the only problem is 1405 00:52:56,740 --> 00:52:58,090 once you wanted them up 1406 00:52:59,140 --> 00:53:01,030 again, police. 1407 00:53:02,260 --> 00:53:04,309 So you are on to number if you have your 1408 00:53:04,310 --> 00:53:06,609 club. Oh, it's a great night tomorrow 1409 00:53:06,610 --> 00:53:07,689 I'm flying. I don't care. 1410 00:53:07,690 --> 00:53:09,249 I want to take pictures. 1411 00:53:09,250 --> 00:53:11,079 So you wind it up. 1412 00:53:11,080 --> 00:53:13,149 You're winding up a bit too much because 1413 00:53:13,150 --> 00:53:15,249 you want to do one bit further than you 1414 00:53:15,250 --> 00:53:16,419 think you will need. 1415 00:53:16,420 --> 00:53:17,800 And then on the next day, 1416 00:53:18,910 --> 00:53:21,969 somebody checks the bags, 1417 00:53:21,970 --> 00:53:23,439 the luggage. 1418 00:53:23,440 --> 00:53:24,440 And here's a 1419 00:53:26,830 --> 00:53:27,830 coming from back 1420 00:53:29,980 --> 00:53:30,980 at 1421 00:53:32,710 --> 00:53:34,509 explaining. 1422 00:53:34,510 --> 00:53:36,699 Oh, actually, you see what 1423 00:53:36,700 --> 00:53:37,840 shape this thing has 1424 00:53:38,950 --> 00:53:40,989 won over a certain amount. 1425 00:53:40,990 --> 00:53:43,419 She's she's a really great person, 1426 00:53:43,420 --> 00:53:44,919 great humor. 1427 00:53:44,920 --> 00:53:47,499 And she was 1428 00:53:47,500 --> 00:53:50,109 on top of a mountain and 1429 00:53:50,110 --> 00:53:52,059 she was setting up her telescope, was 1430 00:53:52,060 --> 00:53:53,060 observing. 1431 00:53:54,100 --> 00:53:56,589 And nearby 1432 00:53:56,590 --> 00:53:58,570 there is a military area. 1433 00:53:59,920 --> 00:54:02,139 One of the residents saw 1434 00:54:02,140 --> 00:54:04,659 somebody putting a 1435 00:54:04,660 --> 00:54:06,790 silhouette that looked like that 1436 00:54:08,770 --> 00:54:09,840 on top of a mountain. 1437 00:54:11,410 --> 00:54:12,410 So 1438 00:54:14,050 --> 00:54:16,839 there is a German, there is a 1439 00:54:16,840 --> 00:54:19,029 if somebody if you observe 1440 00:54:19,030 --> 00:54:20,829 you want to do you want everything to 1441 00:54:20,830 --> 00:54:23,019 stay dark? Because adaptions 1442 00:54:23,020 --> 00:54:24,819 in darkness is something that breaks 1443 00:54:24,820 --> 00:54:26,529 really easily and needs about half an 1444 00:54:26,530 --> 00:54:28,989 hour to rebuild. So you avoid 1445 00:54:28,990 --> 00:54:31,059 light. And there is the term 1446 00:54:31,060 --> 00:54:33,369 vice zao which means 1447 00:54:33,370 --> 00:54:34,660 white light. Pigou 1448 00:54:35,980 --> 00:54:37,569 so the. 1449 00:54:38,860 --> 00:54:41,530 She was there on the telescope, somebody 1450 00:54:42,850 --> 00:54:45,359 they sneaked up on on her. 1451 00:54:45,360 --> 00:54:47,469 We're talking we're talking 1452 00:54:47,470 --> 00:54:49,780 about special ops, 1453 00:54:51,730 --> 00:54:53,889 spec ops, sneaking 1454 00:54:53,890 --> 00:54:56,319 up to her, liking the whole 1455 00:54:56,320 --> 00:54:58,389 area, and 1456 00:54:58,390 --> 00:54:59,909 she just saying fell 1457 00:55:01,810 --> 00:55:04,329 and then looking up and 1458 00:55:04,330 --> 00:55:06,939 seeing guns pointed at her 1459 00:55:06,940 --> 00:55:09,159 and people screaming, go away 1460 00:55:09,160 --> 00:55:10,160 from the rocket launcher. 1461 00:55:13,960 --> 00:55:16,209 So you see, astronomy is 1462 00:55:16,210 --> 00:55:18,699 a really, really peaceful 1463 00:55:18,700 --> 00:55:19,569 hobby. 1464 00:55:19,570 --> 00:55:20,680 But yet again, 1465 00:55:22,000 --> 00:55:24,189 those are some that doesn't happen 1466 00:55:24,190 --> 00:55:26,169 all the time. So I don't want to scare 1467 00:55:26,170 --> 00:55:27,849 you off here, but I just want to to 1468 00:55:27,850 --> 00:55:30,009 listen to those of you up. 1469 00:55:30,010 --> 00:55:32,409 So that's 1470 00:55:32,410 --> 00:55:35,529 how you would build an alt azmath. 1471 00:55:35,530 --> 00:55:36,819 That's a an example. 1472 00:55:36,820 --> 00:55:38,709 So here you have your main mirror. 1473 00:55:38,710 --> 00:55:41,049 You have to Rud's here you have 1474 00:55:41,050 --> 00:55:43,389 your your 1475 00:55:43,390 --> 00:55:45,789 secondary mirror, your focus. 1476 00:55:45,790 --> 00:55:47,859 The focus is something you can build it 1477 00:55:47,860 --> 00:55:49,929 yourself, and especially nowadays 1478 00:55:49,930 --> 00:55:52,269 with three nowadays with 3D 1479 00:55:52,270 --> 00:55:54,489 printers, you can easily print one 1480 00:55:54,490 --> 00:55:55,959 for yourself, but you need high 1481 00:55:55,960 --> 00:55:57,729 precision. And honestly, they don't cost 1482 00:55:57,730 --> 00:56:00,189 a lot. If you get a really, really fancy 1483 00:56:00,190 --> 00:56:02,439 one, you're paying three hundred 1484 00:56:02,440 --> 00:56:03,669 euros. 1485 00:56:03,670 --> 00:56:05,679 But we are talking about really, really 1486 00:56:05,680 --> 00:56:06,829 fancy stuff. 1487 00:56:06,830 --> 00:56:08,829 OK, if you got really big then it goes 1488 00:56:08,830 --> 00:56:11,169 really, really expensive 1489 00:56:11,170 --> 00:56:12,369 actually. How much time do. 1490 00:56:12,370 --> 00:56:13,370 Five minutes. 1491 00:56:14,230 --> 00:56:15,699 Holy crap. 1492 00:56:15,700 --> 00:56:17,400 I mean I was told 1493 00:56:18,790 --> 00:56:20,739 OK, I have five minutes. 1494 00:56:20,740 --> 00:56:22,449 I'm sorry for that. 1495 00:56:22,450 --> 00:56:24,549 So what you can 1496 00:56:24,550 --> 00:56:26,730 make a trust that's called the Dobson. 1497 00:56:28,600 --> 00:56:30,859 So here is a full tube, Dobson 1498 00:56:30,860 --> 00:56:32,949 and that's like kind of the stuff you can 1499 00:56:32,950 --> 00:56:33,549 buy. 1500 00:56:33,550 --> 00:56:36,099 This one is really, really heavy. 1501 00:56:36,100 --> 00:56:38,229 We're talking about they make you can 1502 00:56:38,230 --> 00:56:40,420 separate the pieces here and 1503 00:56:41,590 --> 00:56:43,689 and carry them around because you can't 1504 00:56:43,690 --> 00:56:44,969 cover that in the hole. 1505 00:56:44,970 --> 00:56:47,889 I think it's a 14 inch and 1506 00:56:47,890 --> 00:56:49,840 yeah, that's 1507 00:56:52,450 --> 00:56:53,859 that's a full full one. 1508 00:56:53,860 --> 00:56:55,449 Then it stops. 1509 00:56:55,450 --> 00:56:57,729 This one is a 32 inch Dobson. 1510 00:57:00,290 --> 00:57:01,729 Thirty two, yes. 1511 00:57:01,730 --> 00:57:03,349 So basically what I'm telling you here, 1512 00:57:03,350 --> 00:57:05,539 that's this one here, the 1513 00:57:05,540 --> 00:57:07,819 finder is also 1514 00:57:07,820 --> 00:57:09,919 a Newtonian telescope. 1515 00:57:09,920 --> 00:57:12,169 It's just four and a half inches, 1516 00:57:12,170 --> 00:57:13,429 but that's the finder. 1517 00:57:15,150 --> 00:57:17,579 This mirror here, the 1518 00:57:17,580 --> 00:57:19,949 mirror has that size, so we're talking 1519 00:57:19,950 --> 00:57:22,049 about a really decent one and you can 1520 00:57:22,050 --> 00:57:23,819 see really nice things with it. 1521 00:57:23,820 --> 00:57:25,709 Oh, no, I stand corrected. 1522 00:57:25,710 --> 00:57:27,560 28 inch, sorry. 1523 00:57:30,300 --> 00:57:33,089 And again, I trust 1524 00:57:33,090 --> 00:57:34,619 that that's the classical design with 1525 00:57:34,620 --> 00:57:35,919 eight rods, by the way. 1526 00:57:35,920 --> 00:57:37,889 And here this one is meant for 1527 00:57:37,890 --> 00:57:38,939 photography. 1528 00:57:38,940 --> 00:57:41,039 So this one has to be really, 1529 00:57:41,040 --> 00:57:43,409 really, really, really sturdy. 1530 00:57:43,410 --> 00:57:45,569 You don't want your your camera, which is 1531 00:57:45,570 --> 00:57:47,399 which can be quite heavy here in the 1532 00:57:47,400 --> 00:57:49,949 front to move relative 1533 00:57:49,950 --> 00:57:51,509 to your main mirror. 1534 00:57:51,510 --> 00:57:53,999 That's really, really bad karma. 1535 00:57:54,000 --> 00:57:55,259 You don't want to do that. 1536 00:57:55,260 --> 00:57:56,819 Your picture is going to bring your half 1537 00:57:56,820 --> 00:57:59,519 an hour luminosity 1538 00:57:59,520 --> 00:58:02,009 picture is going to be crap. 1539 00:58:02,010 --> 00:58:04,079 So really, you wanted to 1540 00:58:04,080 --> 00:58:04,979 be as strong as possible. 1541 00:58:04,980 --> 00:58:07,109 So that's why it's made like that 1542 00:58:07,110 --> 00:58:09,300 with a huge diameter in the middle and 1543 00:58:10,710 --> 00:58:13,019 smaller thin outside, because 1544 00:58:13,020 --> 00:58:15,329 it's also mainly supported in the middle. 1545 00:58:15,330 --> 00:58:17,579 So here you have a three 1546 00:58:17,580 --> 00:58:19,949 three wrought design, a two 1547 00:58:19,950 --> 00:58:20,939 design. 1548 00:58:20,940 --> 00:58:23,489 This one is really, really, really 1549 00:58:23,490 --> 00:58:24,539 compact. 1550 00:58:24,540 --> 00:58:26,759 You can the roads are 1551 00:58:26,760 --> 00:58:28,790 separated. You see this here? 1552 00:58:29,820 --> 00:58:31,889 Those are our base 1553 00:58:31,890 --> 00:58:32,890 strengths. 1554 00:58:34,110 --> 00:58:36,179 This thing as setup 1555 00:58:36,180 --> 00:58:37,739 and you can play music with it. 1556 00:58:37,740 --> 00:58:39,719 Not good one, but you could play music 1557 00:58:39,720 --> 00:58:41,999 and this and here 1558 00:58:42,000 --> 00:58:44,189 you have really the buffer in 1559 00:58:44,190 --> 00:58:45,479 front of these. 1560 00:58:45,480 --> 00:58:47,699 So this one is a compromise 1561 00:58:47,700 --> 00:58:49,739 going totally for transportability. 1562 00:58:51,060 --> 00:58:53,459 You lose light if you do that 1563 00:58:53,460 --> 00:58:56,049 because you have the strings going in the 1564 00:58:56,050 --> 00:58:57,449 in the optical path. 1565 00:58:57,450 --> 00:58:59,459 You have this huge thing here. 1566 00:58:59,460 --> 00:59:02,029 So you want to have it really light 1567 00:59:02,030 --> 00:59:03,599 you losing light, but you want it to 1568 00:59:03,600 --> 00:59:05,549 carry it with you. 1569 00:59:05,550 --> 00:59:07,049 And I know and I happen to know that 1570 00:59:07,050 --> 00:59:09,409 stuff has made a 1571 00:59:10,530 --> 00:59:12,609 with this with his motorcycle 1572 00:59:12,610 --> 00:59:13,859 with that. 1573 00:59:13,860 --> 00:59:15,959 And so, yeah, 1574 00:59:15,960 --> 00:59:17,429 everything possible. 1575 00:59:17,430 --> 00:59:19,529 So the top part called I 1576 00:59:19,530 --> 00:59:20,639 have to speed up a bit. 1577 00:59:20,640 --> 00:59:22,529 So if you don't understand something, 1578 00:59:22,530 --> 00:59:24,779 please forgive me on that. 1579 00:59:24,780 --> 00:59:27,599 So the the top part 1580 00:59:27,600 --> 00:59:29,669 has two main components which you want to 1581 00:59:29,670 --> 00:59:31,859 support thoroughly here. 1582 00:59:31,860 --> 00:59:33,779 The the secondary mirror. 1583 00:59:33,780 --> 00:59:36,779 That's the shiny thing that gets what 1584 00:59:36,780 --> 00:59:38,339 and the focus. 1585 00:59:38,340 --> 00:59:39,779 And that's that's one of the fancy ones 1586 00:59:39,780 --> 00:59:41,879 that costs, that costs two 1587 00:59:41,880 --> 00:59:42,880 hundred euros. 1588 00:59:43,590 --> 00:59:45,809 And you want that hat 1589 00:59:45,810 --> 00:59:47,759 to be as loud as possible because you are 1590 00:59:47,760 --> 00:59:49,349 away from the center of mass 1591 00:59:50,430 --> 00:59:52,889 and you want it to be stable. 1592 00:59:52,890 --> 00:59:55,079 You see engineering problems 1593 00:59:55,080 --> 00:59:56,639 coming up. 1594 00:59:56,640 --> 00:59:57,569 Everybody does. 1595 00:59:57,570 --> 00:59:59,429 And solving this problem seems 1596 00:59:59,430 --> 01:00:01,499 impossible. But it's really, 1597 01:00:01,500 --> 01:00:03,599 really well, they're really, 1598 01:00:03,600 --> 01:00:04,799 really good solutions. 1599 01:00:04,800 --> 01:00:07,079 So here you see trusses here 1600 01:00:07,080 --> 01:00:09,239 on the on 1601 01:00:09,240 --> 01:00:11,489 the supports and yeah. 1602 01:00:11,490 --> 01:00:13,619 Here another solution 1603 01:00:13,620 --> 01:00:14,609 on that. 1604 01:00:14,610 --> 01:00:15,569 And yeah. 1605 01:00:15,570 --> 01:00:17,069 So you can solve it. 1606 01:00:17,070 --> 01:00:19,589 People have actually made 1607 01:00:19,590 --> 01:00:21,669 had made second secondary 1608 01:00:21,670 --> 01:00:24,269 mirror supports with guitar strings. 1609 01:00:25,380 --> 01:00:27,389 So everything's possible here. 1610 01:00:29,500 --> 01:00:31,599 Two minutes over 1611 01:00:31,600 --> 01:00:32,529 two minutes. 1612 01:00:32,530 --> 01:00:33,530 It's. 1613 01:00:34,380 --> 01:00:36,659 Maybe I'm speeding 1614 01:00:36,660 --> 01:00:38,749 up here. Sorry, I sorry. 1615 01:00:40,350 --> 01:00:42,209 And here you have the mirror box, which 1616 01:00:42,210 --> 01:00:44,609 is basically quite 1617 01:00:44,610 --> 01:00:45,449 easy. 1618 01:00:45,450 --> 01:00:47,519 You have this structure here which 1619 01:00:47,520 --> 01:00:49,109 supports the mirror here. 1620 01:00:49,110 --> 01:00:51,539 That would be silicone pads if it's done 1621 01:00:51,540 --> 01:00:53,939 and everything movable, easily movable, 1622 01:00:53,940 --> 01:00:56,129 that everything can be canela in such 1623 01:00:56,130 --> 01:00:58,319 a way that there is no, no, no 1624 01:00:58,320 --> 01:00:59,699 to work on the main mirror. 1625 01:00:59,700 --> 01:01:00,659 You don't want that. 1626 01:01:00,660 --> 01:01:02,849 You really don't want that. 1627 01:01:02,850 --> 01:01:04,799 It ruins your image for no particular 1628 01:01:04,800 --> 01:01:06,989 reason. So you don't want to do 1629 01:01:06,990 --> 01:01:07,529 that. 1630 01:01:07,530 --> 01:01:09,719 So here again, 1631 01:01:09,720 --> 01:01:12,299 the the altitude wheel's attached 1632 01:01:12,300 --> 01:01:14,549 to the box and the rods 1633 01:01:14,550 --> 01:01:16,919 here and you basically 1634 01:01:16,920 --> 01:01:19,589 and all that goes on the rocker box, 1635 01:01:19,590 --> 01:01:21,899 which is basically Teflon 1636 01:01:21,900 --> 01:01:23,879 grinding on top of Ebonie Star. 1637 01:01:23,880 --> 01:01:26,219 Ebonie is top counter 1638 01:01:26,220 --> 01:01:28,619 cover, a kitchen counter, 1639 01:01:28,620 --> 01:01:29,829 kitchen counter. 1640 01:01:29,830 --> 01:01:31,949 So, yeah, it's easily 1641 01:01:31,950 --> 01:01:33,639 accessible. They don't produce any more 1642 01:01:33,640 --> 01:01:35,129 alternatives, but yeah. 1643 01:01:35,130 --> 01:01:38,159 So that's how you would do everything. 1644 01:01:38,160 --> 01:01:40,739 I want to thank those guys statis 1645 01:01:40,740 --> 01:01:43,379 Martin Carcillo and the 1646 01:01:43,380 --> 01:01:45,270 People Subsecretary and. 1647 01:01:46,440 --> 01:01:48,629 I want this to I want to dedicate 1648 01:01:48,630 --> 01:01:51,089 this talk to John Dobson, without 1649 01:01:51,090 --> 01:01:53,369 whom this Dobson design 1650 01:01:53,370 --> 01:01:55,169 would not have been possible. 1651 01:01:55,170 --> 01:01:57,299 He died earlier this year, in 1652 01:01:57,300 --> 01:01:59,369 January last year, this year, 1653 01:01:59,370 --> 01:02:00,370 last year. 1654 01:02:01,260 --> 01:02:03,389 So he died earlier this 1655 01:02:03,390 --> 01:02:04,590 year. And, 1656 01:02:05,850 --> 01:02:08,219 yeah, was a huge loss definitely 1657 01:02:08,220 --> 01:02:09,419 for the community. 1658 01:02:09,420 --> 01:02:11,519 And that guy was the one that 1659 01:02:11,520 --> 01:02:13,959 made democratic, 1660 01:02:13,960 --> 01:02:16,169 democratized astronomy 1661 01:02:16,170 --> 01:02:18,089 for everybody, the sidewalk astronomy 1662 01:02:19,530 --> 01:02:22,199 and yeah, some software. 1663 01:02:22,200 --> 01:02:24,239 Just Google it up, open source 1664 01:02:24,240 --> 01:02:25,169 everything. 1665 01:02:25,170 --> 01:02:27,269 Do download it, modify to 1666 01:02:27,270 --> 01:02:29,070 improve it and 1667 01:02:30,240 --> 01:02:32,249 some links where. 1668 01:02:32,250 --> 01:02:33,529 Yeah, cloudy nights. 1669 01:02:33,530 --> 01:02:36,149 That's that's an English forum. 1670 01:02:36,150 --> 01:02:38,759 Everything is organized with forums and 1671 01:02:38,760 --> 01:02:41,709 um, in the sector 1672 01:02:41,710 --> 01:02:43,769 I would have a national media 1673 01:02:43,770 --> 01:02:46,079 are sites 1674 01:02:46,080 --> 01:02:47,729 that are German. 1675 01:02:47,730 --> 01:02:50,129 So everything happens in German 1676 01:02:50,130 --> 01:02:52,619 and. Yeah I 1677 01:02:52,620 --> 01:02:54,719 would. Can we arrange five 1678 01:02:54,720 --> 01:02:56,289 minutes for a Q&A? 1679 01:02:56,290 --> 01:02:58,469 I think that's possible and thank 1680 01:02:58,470 --> 01:02:58,949 you. 1681 01:02:58,950 --> 01:03:00,479 So yeah. 1682 01:03:00,480 --> 01:03:02,609 So if anyone has 1683 01:03:02,610 --> 01:03:04,529 questions, just come to one of the four 1684 01:03:04,530 --> 01:03:06,629 microphones and we'll just, you 1685 01:03:06,630 --> 01:03:07,859 know, just go ahead with microphone 1686 01:03:07,860 --> 01:03:09,089 three. 1687 01:03:09,090 --> 01:03:09,989 Hi. 1688 01:03:09,990 --> 01:03:11,779 I was curious. 1689 01:03:11,780 --> 01:03:12,839 Hello. 1690 01:03:12,840 --> 01:03:15,209 I was curious whether amateur 1691 01:03:15,210 --> 01:03:17,129 astronomers using these systems have ever 1692 01:03:17,130 --> 01:03:19,229 done things like calculate redshift 1693 01:03:20,250 --> 01:03:21,929 and whether they actually look into the 1694 01:03:21,930 --> 01:03:24,089 more sort of scientific side or whether 1695 01:03:24,090 --> 01:03:26,129 it's purely observing. 1696 01:03:26,130 --> 01:03:28,259 There is some science done, 1697 01:03:28,260 --> 01:03:30,090 but it's mainly 1698 01:03:31,710 --> 01:03:34,800 variable stars and, 1699 01:03:36,670 --> 01:03:38,969 um, asteroids and 1700 01:03:38,970 --> 01:03:41,159 and planetoids stuff like that, 1701 01:03:41,160 --> 01:03:43,229 because the problem with you 1702 01:03:43,230 --> 01:03:45,449 could possibly calculate or 1703 01:03:45,450 --> 01:03:47,129 measure redshifts. 1704 01:03:47,130 --> 01:03:49,559 But the matter with that is you need time 1705 01:03:49,560 --> 01:03:51,179 for redshift calculation, you need high 1706 01:03:51,180 --> 01:03:52,180 resolution 1707 01:03:53,970 --> 01:03:55,319 spectrometers. 1708 01:03:55,320 --> 01:03:58,529 And those are expensive 1709 01:03:58,530 --> 01:04:00,569 and they are expensive for a reason. 1710 01:04:00,570 --> 01:04:02,579 So they're really, really hard to make. 1711 01:04:02,580 --> 01:04:04,769 So, yeah, to to calculate 1712 01:04:04,770 --> 01:04:07,019 redshift, it's kind of a hard thing. 1713 01:04:07,020 --> 01:04:08,160 And you can only 1714 01:04:09,270 --> 01:04:11,219 spectrometers need a lot of light. 1715 01:04:11,220 --> 01:04:13,469 So you can only do that on bright objects 1716 01:04:13,470 --> 01:04:14,849 and all the bright objects have already 1717 01:04:14,850 --> 01:04:17,009 been measured, thus 1718 01:04:17,010 --> 01:04:18,689 the hell measured out of them. 1719 01:04:18,690 --> 01:04:20,759 So you can 1720 01:04:20,760 --> 01:04:22,919 do that, but you can't contribute 1721 01:04:22,920 --> 01:04:25,409 in science with that main contribution 1722 01:04:25,410 --> 01:04:26,410 of amateurs. 1723 01:04:28,050 --> 01:04:29,429 Again, as I told you, 1724 01:04:31,110 --> 01:04:33,779 small planetoids 1725 01:04:33,780 --> 01:04:35,849 and variable stars. 1726 01:04:36,930 --> 01:04:39,209 But there's also one site called 1727 01:04:39,210 --> 01:04:41,309 Galaxy Zoo dot com 1728 01:04:41,310 --> 01:04:43,559 where you have pictures 1729 01:04:43,560 --> 01:04:46,049 of galaxies and you can 1730 01:04:46,050 --> 01:04:48,599 sit there on your PC 1731 01:04:48,600 --> 01:04:50,939 works great. If you have to wait on some 1732 01:04:50,940 --> 01:04:53,249 somebody, you can 1733 01:04:53,250 --> 01:04:55,229 say, OK, that's a spiral Galaxy Tab and 1734 01:04:55,230 --> 01:04:57,539 so on. So you can help classify 1735 01:04:57,540 --> 01:04:59,249 galaxies back that. 1736 01:04:59,250 --> 01:05:02,339 So you're welcome. 1737 01:05:02,340 --> 01:05:05,189 Yes, please know my number, too. 1738 01:05:05,190 --> 01:05:06,419 Hello. Yes. 1739 01:05:06,420 --> 01:05:08,279 If you're using purely class for the 1740 01:05:08,280 --> 01:05:10,569 mirror without the shiny surface. 1741 01:05:10,570 --> 01:05:12,659 Yes. Isn't that a bit lost 1742 01:05:12,660 --> 01:05:13,689 of light? 1743 01:05:13,690 --> 01:05:15,329 Yes. Yes, yes it is. 1744 01:05:15,330 --> 01:05:17,669 You have to you have to cover it up. 1745 01:05:17,670 --> 01:05:19,049 I completely forgot that. 1746 01:05:19,050 --> 01:05:20,639 My token. I forgot that completely. 1747 01:05:20,640 --> 01:05:21,839 Thank you for pointing that out. 1748 01:05:22,860 --> 01:05:25,469 You have to send it somewhere. 1749 01:05:25,470 --> 01:05:27,959 You need a vacuum chamber to illuminate 1750 01:05:27,960 --> 01:05:30,059 it and to put also 1751 01:05:30,060 --> 01:05:32,399 a cover material 1752 01:05:32,400 --> 01:05:33,299 on top. 1753 01:05:33,300 --> 01:05:34,300 Um, 1754 01:05:35,670 --> 01:05:36,670 come on. 1755 01:05:38,790 --> 01:05:41,040 Silicon oxide so that you have 1756 01:05:42,060 --> 01:05:43,949 to have that sealed, but you can do it. 1757 01:05:43,950 --> 01:05:45,869 Also at home there's a chemical reaction 1758 01:05:45,870 --> 01:05:48,089 which drops out 1759 01:05:48,090 --> 01:05:50,459 element to the mentor 1760 01:05:50,460 --> 01:05:52,529 soda and you can cover that 1761 01:05:52,530 --> 01:05:55,169 in silver, but it produces hydrogen 1762 01:05:55,170 --> 01:05:56,819 and hydrogen is kind of 1763 01:05:57,960 --> 01:05:59,130 an explosive matter. 1764 01:06:00,150 --> 01:06:02,219 So you want to be careful with that 1765 01:06:02,220 --> 01:06:02,489 magic. 1766 01:06:02,490 --> 01:06:04,649 Number three, I just wanted 1767 01:06:04,650 --> 01:06:06,269 to mention you mentioned Dobson at the 1768 01:06:06,270 --> 01:06:08,519 end, so I just wanted to mention 1769 01:06:08,520 --> 01:06:10,409 something is a funny thing to stop since 1770 01:06:10,410 --> 01:06:12,629 he started astronomy because he was 1771 01:06:12,630 --> 01:06:14,639 converting to Hinduism. 1772 01:06:14,640 --> 01:06:16,919 And the funny thing is Hinduism has very 1773 01:06:16,920 --> 01:06:18,599 oh, no, Christian Christian 1774 01:06:20,280 --> 01:06:21,569 kids. Listen. 1775 01:06:21,570 --> 01:06:23,429 Yeah, it's a funny business. 1776 01:06:23,430 --> 01:06:24,539 Seven twenty years old. 1777 01:06:24,540 --> 01:06:26,729 The problem with Hindus is 1778 01:06:26,730 --> 01:06:29,219 they have to accept different problems 1779 01:06:29,220 --> 01:06:31,709 they have in universities, 1780 01:06:31,710 --> 01:06:34,109 billions and billions of years old. 1781 01:06:34,110 --> 01:06:36,329 And so one of the reasons he tried 1782 01:06:36,330 --> 01:06:38,549 this one was to get people full and 1783 01:06:38,550 --> 01:06:40,239 steady state universe model. 1784 01:06:41,400 --> 01:06:43,859 And so I think it's 1785 01:06:43,860 --> 01:06:44,799 something to show. 1786 01:06:44,800 --> 01:06:46,249 Is that the. 1787 01:06:46,250 --> 01:06:48,439 Tolerant to religious people, they may 1788 01:06:48,440 --> 01:06:50,699 be idiots quite often, but when 1789 01:06:50,700 --> 01:06:52,999 it comes to get a nice outback 1790 01:06:53,000 --> 01:06:55,369 fire, I happen to have seen 1791 01:06:55,370 --> 01:06:57,469 an interview where he said that 1792 01:06:57,470 --> 01:06:59,179 the Big Bang, the Big Bang 1793 01:07:00,200 --> 01:07:01,579 Theory thing is incomplete. 1794 01:07:01,580 --> 01:07:03,889 And we're not talking to show here. 1795 01:07:03,890 --> 01:07:04,909 Yeah, that's bogus. 1796 01:07:04,910 --> 01:07:06,289 He said that. 1797 01:07:06,290 --> 01:07:07,290 True, but. 1798 01:07:08,880 --> 01:07:11,449 He he made a huge contribution, 1799 01:07:11,450 --> 01:07:13,619 just wanted to say, because he had 1800 01:07:13,620 --> 01:07:15,779 a problem with it, because 1801 01:07:15,780 --> 01:07:17,459 we are we're running tight on schedule, 1802 01:07:17,460 --> 01:07:18,479 maybe. 1803 01:07:18,480 --> 01:07:19,730 Thank you for sharing that with us. 1804 01:07:21,570 --> 01:07:22,679 I have a question. 1805 01:07:22,680 --> 01:07:24,869 And you said you cannot use 1806 01:07:24,870 --> 01:07:26,819 regular glass or what kind of glass, I 1807 01:07:26,820 --> 01:07:29,309 suppose, to buy. You want to use glass 1808 01:07:29,310 --> 01:07:31,619 that has a that doesn't 1809 01:07:31,620 --> 01:07:33,629 expand as much with with thermal 1810 01:07:33,630 --> 01:07:36,299 differences because you want it to 1811 01:07:36,300 --> 01:07:38,999 you want to mirror to cool down smoothly 1812 01:07:39,000 --> 01:07:41,459 so you don't have bumps and ridges 1813 01:07:41,460 --> 01:07:43,319 building up just because the glass is 1814 01:07:43,320 --> 01:07:45,389 expanding or cooling down 1815 01:07:45,390 --> 01:07:47,519 because you have to imagine 1816 01:07:47,520 --> 01:07:49,859 you are carrying the telescope from a 20 1817 01:07:49,860 --> 01:07:52,379 degree Celsius perfect environment 1818 01:07:52,380 --> 01:07:54,659 to if you are not lucky 1819 01:07:54,660 --> 01:07:56,159 to a minus 10 degree 1820 01:07:57,480 --> 01:07:58,979 turn, minus degree environment, 1821 01:07:58,980 --> 01:08:00,059 understanding the environment. 1822 01:08:00,060 --> 01:08:02,189 And even with that special glass, 1823 01:08:02,190 --> 01:08:04,679 you need to wait some time 1824 01:08:04,680 --> 01:08:06,299 until the mirror has cooled down. 1825 01:08:06,300 --> 01:08:08,459 Enough that you can observe. 1826 01:08:08,460 --> 01:08:11,099 It's it's really 1827 01:08:11,100 --> 01:08:13,019 that that's the whole thing. 1828 01:08:13,020 --> 01:08:15,269 And if you make small telescopes, 1829 01:08:15,270 --> 01:08:17,459 you can use thin sheets of glass, 1830 01:08:19,020 --> 01:08:21,329 normal, normal floating 1831 01:08:21,330 --> 01:08:22,649 glass for for windows 1832 01:08:24,029 --> 01:08:26,099 and then again, thin sheets cool down 1833 01:08:26,100 --> 01:08:28,169 easily and you have no problem 1834 01:08:28,170 --> 01:08:29,369 at all. 1835 01:08:29,370 --> 01:08:30,449 So that's the only reason. 1836 01:08:30,450 --> 01:08:32,549 What is what is called the glass use. 1837 01:08:33,569 --> 01:08:36,089 It's called Becae seven. 1838 01:08:36,090 --> 01:08:38,699 It's called a Pyrex. 1839 01:08:38,700 --> 01:08:41,339 There are many it's 1840 01:08:41,340 --> 01:08:42,898 basically most of the time it's floating 1841 01:08:42,899 --> 01:08:45,148 glass so that 1842 01:08:45,149 --> 01:08:46,949 many trademarks on it. 1843 01:08:46,950 --> 01:08:49,108 But if you the way I would buy 1844 01:08:49,109 --> 01:08:51,209 glass where that is set up, a guy who 1845 01:08:51,210 --> 01:08:52,799 sells glass for 1846 01:08:54,300 --> 01:08:56,699 for those for those purposes, 1847 01:08:56,700 --> 01:08:58,438 there are many and it's not really it's 1848 01:08:58,439 --> 01:08:59,439 not that expensive. 1849 01:09:00,510 --> 01:09:02,648 OK, so I think that was 1850 01:09:02,649 --> 01:09:04,020 what was it with the questions. 1851 01:09:05,350 --> 01:09:06,419 Looks like it. Yeah. 1852 01:09:06,420 --> 01:09:07,420 Think again.