7个月前

Of course

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There's an old joke about two mathematicians in a cafe. They're arguing about whether ordinary people understand basic mathematics. The first mathematician says yes, of course they do! And the second disagrees.
The second mathematician goes to the toilet, and the first calls over their blonde waitress. He says to her, "in a minute my friend is going to come back from the toilet, and I'm going to ask you a question. I want you to reply, "one third x cubed.'"
"One ther desque," she repeats.
"One third x cubed," the mathematician tries again.
"One thir dek scubed."
"That'll do," he says, and she heads off. The second mathematician returns from the toilet and the first lays him a challenge. "I'll prove it. I'll call over that blonde waitress and ask her a simple integration question, and see if she can answer." The second mathematician agrees, and they call her over.
"My friend and I have a question," the first mathematician asks the waitress. "Do you know what is the integral of x squared?"
"One thir dek scubed," she answers and the second mathematician is impressed and concedes the point.
And as she walks away, the waitress calls over her shoulder,
"Plus a constant."
- I would not consider integration to be basic maths, honestly. Basic maths is addition and multiplication, and maybe vector geometry.
  
  You probably wouldn't consider x86 opcodes to be basic computer literacy either ;-)

One of the most useful concepts ever:
the Curse of Knowledge.
Explaining something to someone? Zoom out. Back up. What if that person were an alien, how much more context would you need to explain?
The curse of knowledge is a cognitive bias that occurs when an individual, who is communicating with others, assumes that others have information that is only available to themselves, assuming they all share a background and understanding. This bias is also called by some authors the curse of expertise.
- My friend really needs to learn about this. He works for Intel and does some really involved stuff, I on the other hand am a moronic jackass factory worker.
  No friend, I haven't the slightest idea what you're trying to tell me you did if you keep using technical terms.
  
  If you said something like “if I were a marketing intern…” or “if I were a college freshman majoring in English, how would you explain it?”
  …would he not know how to clearly communicate still? :)
  Maybe get him with the “is this a curse of knowledge situation?” (along with a link to Wikipedia) heh
- what's it called when you try to be aware of this and inadvertently say stuff that comes off as condescending, umm, asking for a friend
  
  ooooof
  I know for men who are equal opportunity overexplainers it can still be seen as “mansplaining” when overexplaining to women.
  But in general, if your tone of voice is right and it’s still happening, perhaps communicating your intention and a safeguard would work, at least sometimes?
  May I try to explain this? If I start too basic, and overexplain so it feels condescending, please stop me so I can dig into it more technically.
  
  If there's any chance they've heard about a concept, I'll ask if they've heard of it and take them at their word (without comment either way).
  And if they're kinda nodding impatiently, I'll wrap up the explanation and move on to the deeper level
  At first, people will sometimes be defensive or lie about knowing a topic, but after you establish there's no judgement either way with you I've found people become less hesitant about admitting ignorance and will even want to hear your explanation of something to check their knowledge
  I also do the flip side - I pride myself on admitting when I don't know something, so that might play in too
- One of the things I look for in employees is the ability to distill complex topics into the important elements and explain it to someone unfamiliar. Some people are just naturally good at it, and it's a really important skill for moving up a leadership chain.
- Me talking to my dad (who last held the position of professional programmer 30 years ago) about the programming problem I'm working on and vastly overestimating how much he knows about modern software development parlance
- But then you're Mansplaining.
  Even if we have the Patriarchy app4oved mind scanning kits out instructions are to not use them so..I'd hate to accidentally not Mansplain something.
  
  Frustrating!!
  Since there’s no way to fix the incorrect assumptions (a t-shirt proclaiming “I explain granularly to men too!!”?), best bet is probably to get ahead of the assumption with a disclaimer & offer to be receptive to feedback.
  Someone could still be upset I guess but can’t please everyone!
  Discussed a bit below.

Just yesterday I ran into some chucklehead here on Lemmy that had convinced themselves that the average person would interpret "crypto" to mean SSL rather than cryptocurrency.
- I had one last week here on claiming the average person could feed themselves for years by growing cherry tomatoes from 6 tiny plants. Bro is supposed to be a big-time agricultural bigwig
  
  Makes sense. Human beings don't actually need proteins or fats.
  
  Cherry tomatoes are the things you put in a salad at a restaurant to feel healthy, then pick them out once you get back to the table.
  
  That seems like the opposite problem
  
  As a small time backyard gardener I can say from experience that 4 plants made more cherry tomatoes than I could reasonably eat. I was giving ziplock bags of cherry tomatoes away to people at work for a couple months. They probably did produce a year's worth of cherry tomatoes, but they don't refrigerate or freeze particularly well and they're not a great choice for making tomato sauce because of their liquid/pulp/skin ratio.
  Similarly I've found that I can grow a year's supply of red pepper flakes with a whopping two cayenne plants. The rate at which I consume red pepper flakes, I'm about out by the time this year's peppers start ripening.
  I'm able, in my tiny little garden, to grow more of single kinds of foods than I can reasonably eat. I cannot grow enough to sustain my entire diet; I'd need more land than I own to grow grain.
- I saw that thread, I think. Or the same person in another thread talking about the same thing.
- You mean things like Bigfoot?
- That's ludicrous.
  It obviously stands for cryptography in general, not just TLS.
- Holy shit that was weird.
- You know, I think I agree with the spirit of that assertion but not the letter of that assertion.
  There are people who are kind of at their limit knowing that on your phone there's a Facebook app, but you have to use your browser and go to the website on a computer. These folks will hear dial tones and TV static in their heads if you say "secure socket layer" to them. These folks have probably also sat through NordVPN ads and heard words like "secure" and "encrypted" used together, and will probably make understandable mistakes like "how'd someone steal bitcoins? I thought it was encrypted?"

All the code I know is stackoverflow search results.
- Things said by Github copilot.

Isn't there a version about mineralogy?
- That's the original
  
  Oh, OP got me fooled, I thought this is original xkcd, well done on photoshop.
- "So this here is a rock"
  "Uhh, in english please?"
  
  "Oy! Guv! This here's a rock, innit?"
  
  "In English, please?"

It's insane how close that handwriting is to randall's, did he make multiple versions of this comic or was this written by a professional forger?
- For context, here's the original comic:
  
  Holy shit. I remembered the original comic, but didn't remember what the subject matter of it was. So if you hadn't left this comment, I would have just gone on believing that the OP's version was Randall's version.
- Why does it not surprise me at all that this exists?
  https://github.com/ipython/xkcd-font
  
  Wait, that's actually a great font
- There was that one comic that Randall did (Lorenz) where you could choose one of several paths and write your own text in the last panel. In order to implement that Randall had to create a font of his own handwriting. I wouldn't be surprised if OP just ripped the .woff file or similar.

NOP sled gang rise up
- 0x90^0x900x90^0x900x90^0x900x90^0x900x90^0x90
  
  IDS will catch that. You need a logical sled that does effectively nothing but isn’t actually composed of NOPs.
  
  well easy, it adds up to zero ! hah ! checkmate, inverters

NOP is $EA, of course, and... um...
...sorry, I'm just a Commodore 64 scrub, I don't know nothing about this high and mighty Intel 8086 nonsense.
[looking up]
...it's 0x90 on IA-32? WHAT? Someone told me every processor used 0xEA because that was commonly agreed and readily apparent. ...guess I was wrong
- My daughter told me the other day, "I bet I could figure out a Commodore 64 if I had one."
  Good luck figuring out LOAD "*",8,1 by yourself, kid.
  
  With the ubiquity of C64 emulators, that's easy enough to demonstrate by experiment
- Someone told me every processor used 0xEA
  Not sure if this is a riff on the joke or not.
  Back in the day I dabbled in 6510 code, and up until today hadn't even bothered to look at a chart of opcodes for any of its contemporaries. Today I learned that Z80 uses $00 for NOP.
  Loth as I am to admit it, that actually makes sense. Maybe more sense than 65xx which acts more like a divide-by-zero has happened.
  The rest of the opcode table was full of alien looking mnemonics though, and no undocumented single byte opcodes? Freaky, man.
  But the point is that not even Z80 used $EA. If the someone was real they probably meant every 65xx processor.
  
  *Lolth
- I thought NOP was 0x90. Edit: oh I just read the rest of the comment.

I feel attacked.
- I feel like I skipped right over this comment.
  
  JMPed

I mean who hasnt watched "Assembly Language in 100 seconds" by Fireship
- Just looked this up and subscribed to the channel.

It still confuses what basic computer skills the average person lacks. Like, how are you even supposed to troubleshoot your computer, if you don't know the basics about your computer?
- Everyone has a limited time on this earth. Some of us don't mind or actively enjoy spending that time learning about the technology we use. Others, not so much. I think this comic is really spot on because it's hard to understand as a tech literate person just how little other people may know. "What browser are you using?" "What's a browser?"
  The foundational knowledge is not that tough, but when you're just interested in getting the damn thing to work so you can get on with your life, it's easy to get frustrated by having to take a crash course on what the hell a BIOS is before you can try to fix it. And when you learn all that just for it to still be broken, patience quickly runs out.
  As long as people have the general understanding that power cycling will solve a good 75% of issues, I'm happy. I hope people give me the same grace when I pay a someone to fix my car or replace my phone screen (I love building computers, but god I hate working on phones).
  
  For the phone bit, I started off with really old smartphones like a Galaxy S1, but basically any old old phones are really built like mini laptops and are usually pretty modular as they weren't often water resistant or actively anti-repair
  However I fully get your point and fall into the same boat with cars
- Dude I'm the same with my car.
  
  I mean, cars can be demystified the same way computers can: By building and maintaining it yourself. Everyone is afraid to build their first computer, because it seems way too complicated and delicate. Then you actually build your first one, and go “oh hey this actually isn’t so bad after all.”
  Yes, cars (especially modern cars) have a lot more difficult-to-build parts. But modern cars are also a lot like computers in the sense that you don’t need to know every single component on an GPU to be able to install one. You don’t need to be able to build a car part from scratch. The same way you can slot a GPU into a motherboard, you can just buy the entire car part preassembled and bolt it into place. The important part is learning what the different components do, so you can troubleshoot them.
- you don't you just call the most technical person you know and ask them to do it
  
  You got a point there. I also regularly forget that you don't have to know shit about PCs do use windows/Mac.

I mean I'm only missing int3
- I didn't even know they released int2
  
  You guys have int?
- I think it is 0xCC, or in long form 0xCD03

of course nods along

I recently took a class on ARM assembly, and yet I don't even know half of these x86 instructions.
- 'I recently took a french class, and yet I don't even know half of these german words'
  
  I had 5 years of Latin classes and I still know lipke 19 Latin words.

I’m pretty sure I’ve had this exact conversation. Took me a minute to understand what the point was.
- NOP
  
  0x90

They are talking about computer things, that's about how familiar I am with whatever they are talking about.
- Yeah, it's intentionally obscure. Basically, x86 assembly code is a way of telling a processor what to calculate, at a very low level.
  So, it's similar to programming languages, but those actually get translated into x86 assembly code, before it's told to the processor. ("x86" is a certain processor architecture. Others exist, too, most prominently "ARM".)
  But yeah, even with me knowing that much, I'd need to guess what ret and int3 might do.
  Everyone knows jmp and nop, though, of course. 🙃
  
  Of course
  
  return from subroutine, int3 would be something relating to interrupts off the top of my head.
  
  That's the exact same thing. x86 Assembly Code isn't that hard(to know what it is, understanding it is something different),but I havent heard of the other stuff.

As a bytecode tinkerer, I'd say considering NOP to be global knowledge is a slippery slope.
- Might want a sled and a ROPe to have a smooth descent
  
  Careful you aren't thrown off by a retpoline

Now I want to know what int3 does.
- https://en.wikipedia.org/wiki/INT_(x86_instruction) (scroll down to INT3)
  https://stackoverflow.com/a/61946177
  The TL;DR is that it's used by debuggers to set a breakpoint in code.
  For example, if you're familiar with gdb, one of the simplest ways to make code stop executing at a particular point in the code is to add a breakpoint there.
  Gdb replaces the instruction at the breakpoint with 0xCC, which happens to be the opcode for INT 3 --- generate interrupt 3. When the CPU encounters the instruction, it generates interrupt 3, following which the kernel's interrupt handler sends a signal (SIGTRAP) to the debugger. Thus, the debugger will know it's meant to start a debugging loop there.
  
  Hey thank you!
  Not what I thought it was for sure 😃
  How does it work if an instruction gets replaced by the INT3 though?

"oh you laughed at that joke despite the fact that the bridge followed the falling action instead of preceding the punch word? Amateurs shouldn't be allowed to watch comedy."

Here's the source:
https://xkcd.com/2501/
And the alt text:
How could anyone consider themselves a well-rounded adult without a basic understanding of silicate geochemistry? Silicates are everywhere! It's hard to throw a rock without throwing one!

Alt text: "How could anyone consider themselves a well-rounded adult without a basic understanding of silicate geochemistry? Silicates are everywhere! It's hard to throw a rock without throwing one!"
- Silicates are everywhere! It’s hard to throw a rock without throwing one!
  If that's all that's needed to consider yourself having a basic understanding, then I already had it by the time I passed HS.
  Unfortunately, the Alt text doesn't tell us the bar, so we can't know how round we are.

Is there any situation where you'd want to remember the opcodes? Disassemblers should give you user-friendly assembly code, without any need to look at the raw numbers. Maybe it's useful to remember which instructions are pseudo instructions (so you know stuff like jz (jump if zero) being the same as je (jump if equal) making it easier to understand the disassembly), but I don't think you need to remember the opcode numbers for that.
Edit: Maybe with malware analysis where the malware in question may be obfuscated in interesting ways to make the job of binary analysis harder?
- The important thing is to be important. Engineering has to deal with teammates that don’t have these problems, so they equalize.

I'm missing the joke... would anyone be so kind to help me understand?
- The people in the picture are so used to working with assembly language, that even though they know the average person doesn’t know much about assembly, they assume the average person knows a little, which is already way more than the average person actually knows.
  
  I speak fluent x86, I've been writing xor eax, eax before rax was a thing and you had to wonder whether you shouldn't be using xor rax, rax (you shouldn't), I figured out how to write linux binaries in pure assembly before arch was a thing, just don't throw sse or something arcane like aaa at me. But damned if I know a single opcode.
  Reverse engineers are a whole different kind of breed. And apparently they hate rust.
- https://www.explainxkcd.com/wiki/index.php/2501:_Average_Familiarity
  
  That's a great website that I didn't know existed, thanks for sharing!
- NOPe

there is an additional layer to this joke for those who understand turing completeness. And it elevates it to a whole other level of snark.
- Alright this is my cue that I don’t belong here
  
  lol why?
- Are you implying that an assembly language consisting of just ret, int3 and jmp (and nop, of course) is turing-complete? ...are you sure about that?
  
  Bookmarking your comment so I can come back to it in a couple hours, if I hopefully remember to.
  But yes, almost. I don't think the interrupt is necessary and the return isn't under certain architectures. I have a doc on my computer somewhere where I was investigating what the absolute minimum was to make a turning complete machine and, to my recollection, there was only 4-6 instructions that were absolutely necessary. The ones I remember off the top of my head are NAND, MOV, JUMPIF, and then I believe I included NOP in accordance with some principle. RET and INT were convenience features in this design.

Blue collar fucking aircraft worker and I get it.

Stop linking xkcd without including the alt-text.
- It's not the original

You're sixteen, you're beautiful, I'm under arrest
- I love that I'm getting downvoted for a Ringo Starr reference
- what ? I'm nowhere near sixteen

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