WEBVTT 00:00:00.000 --> 00:00:02.299 Every single second, your devices are generating 00:00:02.299 --> 00:00:06.740 just thousands of hidden errors. Oh, yeah. Background 00:00:06.740 --> 00:00:09.580 logs, diagnostic warnings, all of it. Right. 00:00:09.720 --> 00:00:13.099 And if your laptop or your smartphone actually 00:00:13.099 --> 00:00:15.740 tried to save all of that digital exhaust, your 00:00:15.740 --> 00:00:17.719 hard drive would completely fill up. I mean, 00:00:17.839 --> 00:00:19.559 the entire system would crash in a matter of 00:00:19.559 --> 00:00:22.219 hours. Exactly. So how does it survive? How do 00:00:22.219 --> 00:00:25.500 these wildly complex machines keep from just 00:00:25.500 --> 00:00:27.899 suffocating on their own output? It's actually 00:00:27.899 --> 00:00:30.500 a really elegant solution. It is. They survive 00:00:30.500 --> 00:00:33.820 by relying on one of the most brilliant foundational 00:00:33.820 --> 00:00:36.359 pillars of computer science. It's a piece of 00:00:36.359 --> 00:00:39.840 code whose entire specific purpose is to do absolutely 00:00:39.840 --> 00:00:43.079 nothing. It sounds like a joke. But engineering 00:00:43.079 --> 00:00:45.820 a functional void is it's actually one of the 00:00:45.820 --> 00:00:47.960 greatest architectural triumphs of early computing. 00:00:47.979 --> 00:00:51.100 Yeah. Because you cannot build a highly active, 00:00:51.159 --> 00:00:53.420 constructive environment without also building 00:00:53.420 --> 00:00:55.829 a place for the excess to disappear. Welcome 00:00:55.829 --> 00:00:58.689 to today's Deep Dive. We are jumping into a fascinating 00:00:58.689 --> 00:01:01.409 Wikipedia article and a stack of related notes 00:01:01.409 --> 00:01:03.950 detailing something known as the null device. 00:01:04.370 --> 00:01:07.109 The famous black hole of computing. Right. And 00:01:07.109 --> 00:01:09.430 our mission for this deep dive is to explore 00:01:09.430 --> 00:01:12.049 the anatomy of that black hole. We're going to 00:01:12.049 --> 00:01:13.689 figure out what it is, how it actually works 00:01:13.689 --> 00:01:15.569 under the hood to keep your devices running, 00:01:16.170 --> 00:01:20.250 and how this highly technical tool accidentally 00:01:20.250 --> 00:01:22.329 leaked out of the server room. Yeah, it totally 00:01:22.329 --> 00:01:24.750 sparked decades of nerd culture and inside jokes. 00:01:24.829 --> 00:01:27.090 And even electronic dance music, which is wild. 00:01:27.430 --> 00:01:30.769 It's a rare case of a purely architectural mechanism 00:01:30.769 --> 00:01:32.930 just taking on a life of its own. It became a 00:01:32.930 --> 00:01:35.420 whole psychological metaphor. And whether you 00:01:35.420 --> 00:01:38.299 are a seasoned software developer who routes 00:01:38.299 --> 00:01:41.000 things to the void every single day, or you're 00:01:41.000 --> 00:01:43.099 just someone feeling completely overwhelmed by 00:01:43.099 --> 00:01:45.540 the endless barrage of digital information in 00:01:45.540 --> 00:01:48.040 modern life. Which is all of us, basically. Totally. 00:01:48.579 --> 00:01:50.959 Understanding how complex systems gracefully 00:01:50.959 --> 00:01:54.239 handle nothingness is a profound aha moment waiting 00:01:54.239 --> 00:01:56.819 to happen for you. OK, let's unpack this. What 00:01:56.819 --> 00:01:59.480 exactly is the null device? Well, at its most 00:01:59.480 --> 00:02:02.319 basic, literal level within an operating system, 00:02:02.680 --> 00:02:05.099 the null device is a special kind of device file. 00:02:05.140 --> 00:02:08.400 OK. And its assigned job is beautifully, ruthlessly 00:02:08.400 --> 00:02:10.979 simple. It discards all data written to it. Just 00:02:10.979 --> 00:02:14.020 throws it away? Right. You can send it a single 00:02:14.020 --> 00:02:17.180 kilobyte of text, or you can point a continuous 00:02:17.180 --> 00:02:19.979 stream of terabytes at it. It really does not 00:02:19.979 --> 00:02:22.479 matter. It just eats it. It swallows the data 00:02:22.479 --> 00:02:25.419 whole and the data is gone forever. But the crucial 00:02:25.419 --> 00:02:28.379 detail, the part that is so conceptually funny 00:02:28.379 --> 00:02:31.520 to me, is that it doesn't just quietly delete 00:02:31.520 --> 00:02:33.680 the data and ignore the program that sent it. 00:02:33.719 --> 00:02:37.219 Right, it talks back. Yes. The null device actively 00:02:37.219 --> 00:02:40.860 reports back to the system that the right operation 00:02:40.860 --> 00:02:43.819 was entirely successful. That is the brilliant 00:02:43.819 --> 00:02:46.219 little lie at the heart of the void. It provides 00:02:46.219 --> 00:02:48.740 absolute validation. It really makes me think 00:02:48.740 --> 00:02:51.800 of one of those fake thermostats in a giant corporate 00:02:51.800 --> 00:02:54.120 office. You know the ones. Oh, absolutely. You 00:02:54.120 --> 00:02:56.439 walk up feeling too hot, and you crank the dial 00:02:56.439 --> 00:02:59.080 down to 68 degrees. And the digital display lights 00:02:59.080 --> 00:03:02.400 up. Right. It clicks pleasantly. Maybe it even 00:03:02.400 --> 00:03:04.620 flashes a little temperature -adjusted message 00:03:04.620 --> 00:03:07.199 to make you feel in control. But behind the drywall. 00:03:07.449 --> 00:03:10.129 There are no wires. It is not connected to the 00:03:10.129 --> 00:03:12.810 HVAC system at all. It just absorbed your input, 00:03:13.189 --> 00:03:14.689 made you feel like you accomplished something, 00:03:14.849 --> 00:03:17.370 and threw the request into the ether. What's 00:03:17.370 --> 00:03:20.150 fascinating here is why that polite little click, 00:03:20.729 --> 00:03:23.750 that fake validation, is absolutely critical 00:03:23.750 --> 00:03:25.930 to the survival of the operating system. Tell 00:03:25.930 --> 00:03:28.800 me more about that. Whoa. Computers, especially 00:03:28.800 --> 00:03:31.460 at the programmatic level, are incredibly rigid 00:03:31.460 --> 00:03:34.000 and rule -bound. When a software program generates 00:03:34.000 --> 00:03:36.599 an output, it expects that output to go somewhere. 00:03:36.639 --> 00:03:40.039 It demands a destination. Exactly. If a program 00:03:40.039 --> 00:03:43.000 is churning out constant status updates and those 00:03:43.000 --> 00:03:45.560 data streams have nowhere to go, they back up 00:03:45.560 --> 00:03:47.620 in the system's active memory. Like clogging 00:03:47.620 --> 00:03:50.180 a pipe. They clog the pipes. Eventually, the 00:03:50.180 --> 00:03:52.800 machine panics because of unhandled output and 00:03:52.800 --> 00:03:55.469 the whole system. crashes. Because the software 00:03:55.469 --> 00:03:57.830 literally doesn't know how to move on to the 00:03:57.830 --> 00:03:59.870 next instruction until it gets a receipt for 00:03:59.870 --> 00:04:02.669 the last one. Precisely. The program needs closure 00:04:02.669 --> 00:04:05.969 to continue functioning. Wow. By having a null 00:04:05.969 --> 00:04:08.229 device that actively intercepts the data and 00:04:08.229 --> 00:04:10.889 immediately reports message received, operation 00:04:10.889 --> 00:04:13.669 successful. The program feels satisfied. Right. 00:04:13.930 --> 00:04:16.850 It completed its task. It moves on, completely 00:04:16.850 --> 00:04:19.029 unaware that it didn't actually use up a single 00:04:19.029 --> 00:04:22.350 byte of physical hard drive space. The machinery 00:04:22.350 --> 00:04:24.449 of the operating system keeps running smoothly. 00:04:25.009 --> 00:04:27.930 OK, so dumping data in makes perfect sense. But 00:04:27.930 --> 00:04:30.230 what happens if a confused program reaches into 00:04:30.230 --> 00:04:32.889 the void and tries to pull something out? Like 00:04:32.889 --> 00:04:35.250 trying to read from it? Yeah. Does the system 00:04:35.250 --> 00:04:37.250 freeze while it waits for a response from an 00:04:37.250 --> 00:04:40.379 empty room? The engineers anticipated that, actually. 00:04:40.720 --> 00:04:43.540 If a program insists on reading input from the 00:04:43.540 --> 00:04:46.180 null device, it doesn't leave the program hanging. 00:04:46.639 --> 00:04:49.800 The null device immediately yields an EOF. An 00:04:49.800 --> 00:04:52.500 end of file marker. Right. It instantly says, 00:04:52.699 --> 00:04:54.319 hey, there is nothing here for you to read. We 00:04:54.319 --> 00:04:55.959 were already at the end of the document. So it 00:04:55.959 --> 00:04:58.980 just shuts it down immediately. Exactly. The 00:04:58.980 --> 00:05:00.860 requesting program accepts that it reached the 00:05:00.860 --> 00:05:03.560 end of the data stream, stops asking, and gracefully 00:05:03.560 --> 00:05:06.379 moves on. It is a perfectly sealed loop of logic. 00:05:06.540 --> 00:05:09.139 Looking at the history in our notes, this elegant 00:05:09.139 --> 00:05:11.839 solution has actually been around almost as long 00:05:11.839 --> 00:05:14.399 as modern computing itself. Yeah, going way back. 00:05:14.740 --> 00:05:18.480 Back in 1973, in version 4 Unix, the architects 00:05:18.480 --> 00:05:20.779 tried to handle this just by using an empty regular 00:05:20.779 --> 00:05:22.980 file. Which didn't really work out. Right, it 00:05:22.980 --> 00:05:26.220 wasn't robust enough. So by version 5 Unix, just 00:05:26.220 --> 00:05:29.319 a year later in 1974, the null device got these 00:05:29.319 --> 00:05:31.920 active modern semantics we were talking about. 00:05:32.540 --> 00:05:36.300 The system needed a dedicated mechanism for nothingness. 00:05:36.500 --> 00:05:38.860 Because an empty file is passive. A null device 00:05:38.860 --> 00:05:41.939 is active. It actively consumes and actively 00:05:41.939 --> 00:05:46.060 responds. That shift in 1974 fundamentally changed 00:05:46.060 --> 00:05:48.300 how operating systems manage resources. What 00:05:48.300 --> 00:05:51.339 blows my mind is how universal this concept became 00:05:51.339 --> 00:05:54.000 across entirely different computing civilizations. 00:05:54.199 --> 00:05:56.339 Every system had to figure it out. Over the decades, 00:05:56.740 --> 00:05:58.980 every major operating system had to build their 00:05:58.980 --> 00:06:02.060 own unique temple to the void. In Unix, and the 00:06:02.060 --> 00:06:04.180 Unix -like systems we still use today, like Mac 00:06:04.180 --> 00:06:06.879 OS or Linux, it is famously called slash dev 00:06:06.879 --> 00:06:09.860 slash null. But then older systems like CPM and 00:06:09.860 --> 00:06:13.269 DOS called it NUL, NUL. Internally written as 00:06:13.269 --> 00:06:16.029 backslash dev, backslash NUL. And newer Windows 00:06:16.029 --> 00:06:18.230 systems use that too, right? Just null. Yeah. 00:06:18.509 --> 00:06:20.990 Newer Windows uses null. If you're working in 00:06:20.990 --> 00:06:22.850 Windows PowerShell, the equivalent is dollar 00:06:22.850 --> 00:06:25.370 sign null. Oh, interesting. The classic Amiga 00:06:25.370 --> 00:06:27.970 operating systems, which is a real blast from 00:06:27.970 --> 00:06:30.089 the past. Oh, I love the Amiga. They called it 00:06:30.089 --> 00:06:34.259 NIL colon. OpenVMS went with NL colon. My favorite, 00:06:34.660 --> 00:06:37.759 though, has to be the massive IBM mainframes, 00:06:38.160 --> 00:06:42.000 the old Doe S360 and OS 360 systems from the 00:06:42.000 --> 00:06:45.779 1960s. Oh, the punch card days. Yes. When operators 00:06:45.779 --> 00:06:48.540 were writing their job control language, which 00:06:48.540 --> 00:06:50.899 is the incredibly strict code used to tell the 00:06:50.899 --> 00:06:53.519 mainframe what to do, they had to assign these 00:06:53.519 --> 00:06:57.560 empty files to a variable called ddDoMM. And 00:06:57.560 --> 00:07:01.990 we should explain why IBM needed DDDMY, because 00:07:01.990 --> 00:07:04.069 it perfectly illustrates the problem the null 00:07:04.069 --> 00:07:06.889 device solves. Please do. In the era of job control 00:07:06.889 --> 00:07:09.509 language, you were dealing with punch cards and 00:07:09.509 --> 00:07:12.709 literal room -sized computers. The code was brutally 00:07:12.709 --> 00:07:15.430 unforgiving. Super strict. If a program was written 00:07:15.430 --> 00:07:18.029 to output a report to a printer, but the user 00:07:18.029 --> 00:07:19.990 running the program didn't actually want or need 00:07:19.990 --> 00:07:21.930 a physical copy of that report, they couldn't 00:07:21.930 --> 00:07:23.810 just tell the mainframe to skip it. The mainframe 00:07:23.810 --> 00:07:26.209 would just refuse to run. It would completely 00:07:26.209 --> 00:07:29.230 halt. The code demanded an output destination. 00:07:29.389 --> 00:07:32.649 Wow. So programmers would route that specific 00:07:32.649 --> 00:07:36.870 output requirement to DDU -DU -MMY. They fooled 00:07:36.870 --> 00:07:39.050 the million -dollar mainframe into thinking it 00:07:39.050 --> 00:07:41.389 had successfully printed a report to a physical 00:07:41.389 --> 00:07:44.269 machine allowing the rest of the critical calculations 00:07:44.269 --> 00:07:47.170 to continue uninterrupted. That is so clever. 00:07:47.589 --> 00:07:50.089 So we have established this brilliant architectural 00:07:50.089 --> 00:07:52.649 trick of throwing data into a void to keep the 00:07:52.649 --> 00:07:55.209 system from crashing. But a tool that powerful 00:07:55.209 --> 00:07:57.569 isn't just a safety valve, right? No, not at 00:07:57.569 --> 00:07:59.389 all. Smart developers are going to weaponize 00:07:59.389 --> 00:08:02.750 it. How are programmers using this void proactively 00:08:02.750 --> 00:08:05.550 in their day -to -day work? The most common practical 00:08:05.550 --> 00:08:08.129 technique is called redirection. Okay. When you 00:08:08.129 --> 00:08:10.589 run a command in a terminal, it typically produces 00:08:10.589 --> 00:08:13.110 a firehose of data on your screen. Just lines 00:08:13.110 --> 00:08:15.250 and lines of text scrolling by. Right. Some of 00:08:15.250 --> 00:08:17.230 that is the actual result you want to see, but 00:08:17.230 --> 00:08:19.949 a vast majority of it might be minor warnings 00:08:19.949 --> 00:08:22.769 for both progress updates or diagnostic chatter 00:08:22.769 --> 00:08:24.790 that you simply do not care about. So they just 00:08:24.790 --> 00:08:26.850 get rid of it? Developers will literally point 00:08:26.850 --> 00:08:29.430 that exhaust pipe directly into the null device. 00:08:29.639 --> 00:08:31.519 So the program still runs, the important stuff 00:08:31.519 --> 00:08:34.179 still gets processed, but all the annoying noise 00:08:34.179 --> 00:08:36.480 is silently vaporized before it ever clutters 00:08:36.480 --> 00:08:39.340 up your screen. Exactly. You are manually filtering 00:08:39.340 --> 00:08:42.019 your reality by routing the garbage to the void. 00:08:42.279 --> 00:08:43.700 You know, I was trying to wrap my head around 00:08:43.700 --> 00:08:46.080 why anyone would purposely throw away data they 00:08:46.080 --> 00:08:49.340 just ask the computer to process. It seems counterintuitive. 00:08:49.440 --> 00:08:52.720 It does. And then I realized... What if you are 00:08:52.720 --> 00:08:54.679 doing a test run like the example we have in 00:08:54.679 --> 00:08:58.399 our notes of the tar command? Tar is a classic 00:08:58.399 --> 00:09:01.240 file archiving utility. It bundles huge amounts 00:09:01.240 --> 00:09:04.100 of files together. Take archive. It is a heavy 00:09:04.100 --> 00:09:07.299 duty tool. So imagine you have a massive directory, 00:09:07.720 --> 00:09:10.320 thousands of complex files, gigabytes of data, 00:09:10.320 --> 00:09:13.240 and you want to test the utility to see if it 00:09:13.240 --> 00:09:15.320 will hit any read errors or permission issues 00:09:15.320 --> 00:09:18.120 while packing all this up. Right. But you absolutely 00:09:18.120 --> 00:09:20.759 do not want to waste time and hard drive space. 00:09:20.750 --> 00:09:25.789 actually creating a massive 50 gigabyte duplicate 00:09:25.789 --> 00:09:29.330 archive file just for a basic test. It would 00:09:29.330 --> 00:09:31.950 bring your workflow to a grinding halt. So you 00:09:31.950 --> 00:09:34.090 type the command to create the archives, but 00:09:34.090 --> 00:09:36.490 you point the destination directly into slash 00:09:36.490 --> 00:09:39.129 dev slash null. Brilliant. The utility goes through 00:09:39.129 --> 00:09:41.429 all the motions. It reads every single file. 00:09:41.490 --> 00:09:43.990 It processes them. It reports any errors it encounters 00:09:43.990 --> 00:09:47.960 to your screen. But the massive 50 gigabyte payload 00:09:47.960 --> 00:09:50.700 it is simultaneously generating. Toss straight 00:09:50.700 --> 00:09:53.139 into the incinerator. Exactly. You get all the 00:09:53.139 --> 00:09:55.539 diagnostic benefits of the process with zero 00:09:55.539 --> 00:09:57.559 physical baggage. That's the ultimate dry run. 00:09:57.779 --> 00:09:59.539 Wait, hold on. This brings up a question. Sure. 00:09:59.940 --> 00:10:02.779 If slash dev slash null is officially classified 00:10:02.779 --> 00:10:05.799 as a file in Unix, why can't I just use it as 00:10:05.799 --> 00:10:08.220 my ultimate permanent trash can? What do you 00:10:08.220 --> 00:10:11.029 mean? Why can't I just take a giant folder full 00:10:11.029 --> 00:10:14.450 of blurry photos or old documents, use the Unix 00:10:14.450 --> 00:10:16.490 MV the move command and just shove the whole 00:10:16.490 --> 00:10:19.389 physical folder into slash dev slash null to 00:10:19.389 --> 00:10:22.629 instantly nuke it? It is a totally logical assumption, 00:10:23.070 --> 00:10:25.470 but it highlights a vital nuanced distinction 00:10:25.470 --> 00:10:28.830 in how operating systems separate types of data. 00:10:29.629 --> 00:10:32.470 Slash dev slash null is technically a special 00:10:32.470 --> 00:10:35.870 file, not a directory. It is not a container 00:10:35.870 --> 00:10:38.370 with dimensions. You cannot move a pre -existing 00:10:38.370 --> 00:10:41.610 physical file or folder into it. Why not if its 00:10:41.610 --> 00:10:44.389 whole job is to eat beta? Because of the fundamental 00:10:44.389 --> 00:10:46.309 difference between a real -time stream of data 00:10:46.309 --> 00:10:49.190 and a stored block of data. A stream versus a 00:10:49.190 --> 00:10:52.149 block. Right. When you use the move command on 00:10:52.149 --> 00:10:55.090 a folder of photos, you are asking the file system 00:10:55.090 --> 00:10:57.909 to take a physical block of data sitting statically 00:10:57.909 --> 00:11:00.330 on your hard drive and relocate its address. 00:11:00.490 --> 00:11:03.769 Oh, I see. slash dev slash null cannot process 00:11:03.769 --> 00:11:06.389 static blocks. It is a device interface designed 00:11:06.389 --> 00:11:09.149 to intercept real -time streams of data as they're 00:11:09.149 --> 00:11:11.169 actively being generated by a process. Oh, that 00:11:11.169 --> 00:11:12.990 makes so much sense. So it is the difference 00:11:12.990 --> 00:11:15.490 between turning on a hose and letting the flowing 00:11:15.490 --> 00:11:18.429 water run down a drain versus taking a solid 00:11:18.429 --> 00:11:20.549 50 -pound block of ice and trying to forcefully 00:11:20.549 --> 00:11:23.389 cram it into that same drain pipe. That is the 00:11:23.389 --> 00:11:25.669 perfect way to visualize it. The drain is engineered 00:11:25.669 --> 00:11:28.269 exclusively for the flow. It will reject the 00:11:28.269 --> 00:11:30.889 rigid structure of a pre -existing block. Just 00:11:30.889 --> 00:11:33.610 to round out the weird mechanics of it, what 00:11:33.610 --> 00:11:36.070 happens if you try to use the Unix cat command 00:11:36.070 --> 00:11:38.990 on the void? Oh, this is fun. Because the cat 00:11:38.990 --> 00:11:41.269 command usually reads a file and spits all of 00:11:41.269 --> 00:11:44.090 its text out onto your screen. But if you type 00:11:44.090 --> 00:11:49.029 cat slash dev slash null. It does absolutely 00:11:49.029 --> 00:11:51.230 nothing. Because it instantly hits that end of 00:11:51.230 --> 00:11:53.970 file marker we talked about. Exactly. It is essentially 00:11:53.970 --> 00:11:57.429 equivalent to running the Unix command true or 00:11:57.429 --> 00:12:00.330 just typing a colon. Which do what? Both of those 00:12:00.330 --> 00:12:02.549 are commands that literally do nothing except 00:12:02.549 --> 00:12:06.230 return a success status to the system. The architecture 00:12:06.230 --> 00:12:09.029 of nothingness is surprisingly robust. It covers 00:12:09.029 --> 00:12:11.370 every possible angle of interaction. It really 00:12:11.370 --> 00:12:13.389 does. Here's where it gets really interesting, 00:12:13.549 --> 00:12:15.509 though. We have established the technical mechanics. 00:12:15.909 --> 00:12:18.110 We know what the void is, how it intercepts streams, 00:12:18.169 --> 00:12:20.289 and why it lies to the system to keep things 00:12:20.289 --> 00:12:23.190 running. Right. But a concept this elegant and 00:12:23.190 --> 00:12:25.710 this absolute It doesn't just stay trapped in 00:12:25.710 --> 00:12:28.750 the code. It leaks out. It becomes culture. It 00:12:28.750 --> 00:12:31.490 evolves into a pervasive metaphor. Yes. This 00:12:31.490 --> 00:12:35.490 1970s Unix architecture blossomed into the everyday 00:12:35.490 --> 00:12:39.070 jargon of programmers. The null device is famously 00:12:39.070 --> 00:12:41.789 known in hacker communities as the bit bucket, 00:12:41.990 --> 00:12:44.669 or simply the black hole. It provided a shared 00:12:44.669 --> 00:12:47.610 vocabulary for an absolute dead end, a place 00:12:47.610 --> 00:12:50.370 of no return. And developers started using it 00:12:50.370 --> 00:12:52.750 as a jocular brush off in their social lives. 00:12:52.850 --> 00:12:55.019 Oh yeah, you hear it all the time. someone might 00:12:55.019 --> 00:12:57.340 be complaining in an office and a programmer 00:12:57.340 --> 00:12:59.860 will just casually say, please send complaints 00:12:59.860 --> 00:13:03.620 to slash dev slash null. Yep. Which is an incredibly 00:13:03.620 --> 00:13:06.639 nerdy, highly specific way of saying, don't bother 00:13:06.639 --> 00:13:08.500 sending me your complaints because I'm absolutely 00:13:08.500 --> 00:13:10.340 not going to read them. But I will pretend I 00:13:10.340 --> 00:13:12.860 did. You also see people using it as an excuse 00:13:12.860 --> 00:13:15.919 saying, sorry, my mail got archived in slash 00:13:15.919 --> 00:13:18.659 dev slash null. That's hilarious. It is a technical 00:13:18.659 --> 00:13:20.480 absolution for deleting an email you didn't want 00:13:20.480 --> 00:13:23.279 to reply to or simply telling a coworker to read 00:13:23.279 --> 00:13:26.789 direct. to slash dev slash null which translates 00:13:26.789 --> 00:13:29.610 to please cease your current output stream and 00:13:29.610 --> 00:13:32.429 go away. We even see this applied to real world 00:13:32.429 --> 00:13:35.470 financial boundaries. Like the iPhone dev team, 00:13:35.669 --> 00:13:38.330 a very prominent group in the early iOS jailbreaking 00:13:38.330 --> 00:13:41.149 community. They used to get bombarded with people 00:13:41.149 --> 00:13:43.070 asking how they could donate money to support 00:13:43.070 --> 00:13:45.549 their software tools. Oh, right. I remember this. 00:13:45.710 --> 00:13:48.929 The team famously used the phrase send donations 00:13:48.929 --> 00:13:52.990 to slash dev slash null. They used a Unix file 00:13:52.990 --> 00:13:56.210 path to politely but firmly declare that they 00:13:56.210 --> 00:13:58.759 refuse to accept money. And out of all these 00:13:58.759 --> 00:14:01.120 metaphors, a kind of modern mythology started 00:14:01.120 --> 00:14:04.240 to form. We see the personification of the void. 00:14:04.500 --> 00:14:08.299 Oh, Dave -null. Or sometimes Dev -null. The fictitious 00:14:08.299 --> 00:14:10.919 persona created by developers. Take that up with 00:14:10.919 --> 00:14:13.720 Dave -null and HR. Yes. It is the computer science 00:14:13.720 --> 00:14:15.659 equivalent of telling someone to go complain 00:14:15.659 --> 00:14:18.200 to a brick wall. You are giving a human face 00:14:18.200 --> 00:14:20.820 to the incinerator. It softens the absolute franality 00:14:20.820 --> 00:14:22.820 of the concept. And once you name the void Dev 00:14:22.820 --> 00:14:25.259 -null, the cultural crossover is inevitable. 00:14:25.379 --> 00:14:28.419 It has a distinct cyberpunk ring to it. It really 00:14:28.419 --> 00:14:31.340 does. And mainstream media absolutely ran with 00:14:31.340 --> 00:14:35.679 it. In 1996, the tech broadcaster Leo Laporte 00:14:35.679 --> 00:14:38.399 actually created an animated virtual reality 00:14:38.399 --> 00:14:40.820 character named Dev Null for his computer TV 00:14:40.820 --> 00:14:43.919 series, The Sight on MSNBC. I remember that character. 00:14:44.220 --> 00:14:46.500 Millions of people were watching a literal avatar 00:14:46.500 --> 00:14:48.679 of the Bitbucket on national television. The 00:14:48.679 --> 00:14:51.080 name pops up everywhere in the late 90s and early 00:14:51.080 --> 00:14:55.649 2000s. In the video game Vampire. The Masquerade 00:14:55.649 --> 00:14:58.450 Dash Redemption. There is a vampire hacker character 00:14:58.450 --> 00:15:01.750 literally named Dev Slash Null. No way! Yeah. 00:15:02.129 --> 00:15:04.250 There's even a real -life electronic dance music 00:15:04.250 --> 00:15:07.110 producer and jungle DJ who performs and releases 00:15:07.110 --> 00:15:09.909 records under the name Dev Slash Null. Even corporate 00:15:09.909 --> 00:15:12.230 marketing departments realize the power of the 00:15:12.230 --> 00:15:15.789 joke. Oh, the Apple ad? Yes. Apple ran an advertisement 00:15:15.789 --> 00:15:18.789 in 2002 pitching their new Titanium PowerBook 00:15:18.789 --> 00:15:22.070 G4 laptop. The official ad copy boasted that 00:15:22.070 --> 00:15:27.120 this new machine sends other UNA - Which is a 00:15:27.120 --> 00:15:29.779 massive, highly targeted flex, if you understand 00:15:29.779 --> 00:15:31.870 the underlying operating system. Right. They 00:15:31.870 --> 00:15:35.070 are telling developers, our laptop is so powerful, 00:15:35.450 --> 00:15:38.210 it reduces the entire competition to discarded, 00:15:38.210 --> 00:15:40.830 deleted data streams. If we connect this to the 00:15:40.830 --> 00:15:43.370 bigger picture, all of these cultural artifacts, 00:15:43.549 --> 00:15:47.090 the EDM DJ, the vampire hacker, the Apple advertisement, 00:15:47.549 --> 00:15:49.909 they represent something vital about how technical 00:15:49.909 --> 00:15:52.850 communities function. Oh, so? These shared inside 00:15:52.850 --> 00:15:55.370 jokes build the necessary sense of identity. 00:15:56.370 --> 00:15:58.570 Computing, especially in its earlier decades, 00:15:58.889 --> 00:16:01.629 could be an incredibly solitary, abstract profession. 00:16:01.690 --> 00:16:03.889 You are working with invisible forces. Exactly. 00:16:04.070 --> 00:16:06.529 Having a shared mythology creates a bridge between 00:16:06.529 --> 00:16:08.870 isolated developers. Like the classic Sissigman 00:16:08.870 --> 00:16:11.230 joke, the system administrator runs into the 00:16:11.230 --> 00:16:13.149 room and frantically warns the office, everyone 00:16:13.149 --> 00:16:16.450 stop working, the servers slash dev slash null 00:16:16.450 --> 00:16:19.509 is 98 % full. Which is physically impossible. 00:16:19.590 --> 00:16:22.169 You cannot fill a void. Right. But sharing that 00:16:22.169 --> 00:16:24.830 moment of impossible panic separates the insiders 00:16:24.830 --> 00:16:27.509 from the the outsiders. It is a shibboleth. That 00:16:27.509 --> 00:16:30.210 desire to make the invisible visible perfectly 00:16:30.210 --> 00:16:33.710 sets up the legendary 1995 April Fool's prank. 00:16:34.090 --> 00:16:36.809 The German computer magazine said it ran a completely 00:16:36.809 --> 00:16:39.210 straight -faced article reporting that engineers 00:16:39.210 --> 00:16:42.750 had finally developed an enhanced slash dev slash 00:16:42.750 --> 00:16:45.570 null chip. A physical hardware implementation 00:16:45.570 --> 00:16:49.789 of the software black hole. Yes. The joke was 00:16:49.789 --> 00:16:52.529 that you would plug this physical microchip into 00:16:52.529 --> 00:16:55.210 your motherboard and it would efficiently dispose 00:16:55.210 --> 00:16:58.009 of all your system's incoming garbage data by 00:16:58.009 --> 00:17:00.669 converting it into a flicker on an internal glowing 00:17:00.669 --> 00:17:03.169 LED. Just a little light blinking. Just imagine 00:17:03.169 --> 00:17:05.329 a little light inside your computer case that 00:17:05.329 --> 00:17:07.930 blinks every single time a background error message 00:17:07.930 --> 00:17:10.849 is destroyed. It is brilliant satire. It takes 00:17:10.849 --> 00:17:13.609 this highly abstract invisible software process 00:17:13.609 --> 00:17:16.410 that we rely on every second and gives it a deeply 00:17:16.410 --> 00:17:18.789 satisfying physical manifestation. We want to 00:17:18.789 --> 00:17:21.049 see it work. Deep down we all want to see the 00:17:21.049 --> 00:17:23.430 garbage being destroyed. We want to see the fake 00:17:23.430 --> 00:17:25.690 thermostat light up when the data is vaporized. 00:17:26.049 --> 00:17:30.039 So what does this all mean? We started with the 00:17:30.039 --> 00:17:32.700 paradox of a device engineer to do absolutely 00:17:32.700 --> 00:17:35.099 nothing and we have traced its evolution from 00:17:35.099 --> 00:17:40.000 1973 Unix architecture all the way to EDM DJs 00:17:40.000 --> 00:17:42.319 and April Fool's jokes. It's been quite a journey. 00:17:42.460 --> 00:17:44.200 But bringing it back to you, listening to this 00:17:44.200 --> 00:17:47.299 right now, in a modern world where we are constantly 00:17:47.299 --> 00:17:50.200 bombarded by information overload, the endless 00:17:50.200 --> 00:17:52.799 push notifications, the unread emails, the 24 00:17:52.799 --> 00:17:55.660 -hour news feeds, we could probably all use a 00:17:55.660 --> 00:18:00.420 personal slash dev slash null. Exactly, a mental 00:18:00.420 --> 00:18:02.660 mechanism where we can successfully receive an 00:18:02.660 --> 00:18:05.339 unwanted input, politely acknowledge that it 00:18:05.339 --> 00:18:07.900 exists, and then immediately permanently discard 00:18:07.900 --> 00:18:09.619 it without letting it take up a single megabyte 00:18:09.619 --> 00:18:11.740 of our brain's hard drive space. I love that. 00:18:11.920 --> 00:18:13.720 The next time you feel overwhelmed by digital 00:18:13.720 --> 00:18:16.099 noise, just route it to Dave Knoll. That is an 00:18:16.099 --> 00:18:18.920 incredibly healthy way to apply a 1970s computing 00:18:18.920 --> 00:18:22.329 concept. to modern life. And it actually leads 00:18:22.329 --> 00:18:24.970 me to a final provocative thought drawn from 00:18:24.970 --> 00:18:27.410 the see also section of our notes. Oh, what is 00:18:27.410 --> 00:18:29.950 hiding in the see also section? A concept called 00:18:29.950 --> 00:18:33.210 write only memory. Write only memory, as opposed 00:18:33.210 --> 00:18:36.549 to read only memory or ROM. Correct. We have 00:18:36.549 --> 00:18:39.250 spent this entire deep dive exploring slash dev 00:18:39.250 --> 00:18:42.230 slash null, which is a software black hole. But 00:18:42.230 --> 00:18:44.720 the concept begs a fascinating question about 00:18:44.720 --> 00:18:47.519 the physical world. What happens when hardware 00:18:47.519 --> 00:18:50.119 engineers actually attempt to design physical 00:18:50.119 --> 00:18:53.140 computer memory that can only be written to but 00:18:53.140 --> 00:18:56.279 can never ever be read from? Wait, what possible 00:18:56.279 --> 00:18:58.980 use could a computer have for physical silicon 00:18:58.980 --> 00:19:01.420 components that are designed solely to forget 00:19:01.420 --> 00:19:03.480 the information you put into them? That is the 00:19:03.480 --> 00:19:06.299 ultimate question. It pushes the philosophy of 00:19:06.299 --> 00:19:08.859 the void directly under the circuitry itself. 00:19:09.109 --> 00:19:12.069 Back in 1972, an engineer named John G. Curtis 00:19:12.069 --> 00:19:14.490 at the electronics company Signetix actually 00:19:14.490 --> 00:19:17.789 created a highly detailed, entirely fake, two 00:19:17.789 --> 00:19:21.009 -page data sheet for a write -only memory microchip. 00:19:21.390 --> 00:19:23.390 They spoofed an entire hardware component. They 00:19:23.390 --> 00:19:25.089 went all out. The data sheet looked completely 00:19:25.089 --> 00:19:27.490 official. It had complex specifications for input 00:19:27.490 --> 00:19:29.950 voltage, cooling requirements, and intricate 00:19:29.950 --> 00:19:31.930 diagrams showing data going into the pins of 00:19:31.930 --> 00:19:34.069 the chip and just permanently disappearing. That 00:19:34.069 --> 00:19:36.769 is amazing. They published it as a joke, but 00:19:36.769 --> 00:19:39.920 it perfectly mirrored the software. slash dev 00:19:39.920 --> 00:19:43.220 slash null in a physical form. I highly recommend 00:19:43.220 --> 00:19:46.420 looking into the history of that 1972 signetix 00:19:46.420 --> 00:19:49.119 spoof just to see how deep the rabbit hole of 00:19:49.119 --> 00:19:51.859 engineered nothingness truly goes. That is wild. 00:19:51.960 --> 00:19:53.640 I am definitely going to have to look up those 00:19:53.640 --> 00:19:55.400 diagrams. Well, the next time you drop a piece 00:19:55.400 --> 00:19:58.200 of digital junk into the void or clear out your 00:19:58.200 --> 00:20:00.400 spam folder, take a second to appreciate the 00:20:00.400 --> 00:20:02.539 polite little click of that invisible thermostat 00:20:02.539 --> 00:20:05.240 successfully processing your request. Thanks 00:20:05.240 --> 00:20:06.519 for joining us on this deep dive.