Explaining Gödel's Incompleteness Theorem to a Twelve Year Old - <AUTHOR> http://www.reddit.com/r/explainlikeimfive/comments/j8yq3/can_anyone_eli5_or_12_the_implications_of_gödels/c2a5pp4

<comment><USER3> Unfortunately this doesn't get at the heart of GIT. I'm pretty math-ignorant so correct me if I'm getting this wrong, but I'd do it like this:

Hey, $youngster, imagine that we have a Big Book of Mathematics. This book describes addition, multiplication, and some logic. There are pages like this:

        Fact: 1 + 4 = 5
        Fact: 2 + 3 = 5

        Rule: Things that are equal to the same thing are equal to each other.

        So now we know: 1 + 4 = 2 + 3

On another page of the book you see this:

        Rule 1. The next sentence is false.
        Rule 2. The previous sentence is true.

        So now we know:... nothing??

It's kind of funny right? Both of those things can't be true within the rules they set up. The whole thing is inconsistent. We don't learn anything, we don't know anything. In fact this one page ruins the whole book. We should just rip it out.

But then, there's another book -- Gödel's book of Mathematics. On yet another page of the book there's this:

        Rule: You can't prove the rule on this page!

        So now we know: _________

That's just as funny, like the other one right? But here's the really weird part: is it wrong? (Let them get to No.) That's right, you can't prove the rule on this page. But it's still true. Fill in the blank: now we know "it's true!"

That means that there are at least a few weird things that you can't prove are true, but which are true. That's what Gödel thought was funny!

Next steps: try to get them to notice what's weird about both cases, in that they refer to themselves. Walk them through the idea that maybe you could just outlaw referring to a rule on the page. I can't think of an easy way to explain Gödel numbers, so I'd just have to say that he showed that if you allowed a book to have numbers and addition and whatnot, you could still sneak in weird things like that, by using a secret code.

</comment><comment><USER4> I emailed this explanation to my son, and asked him if he understood it, He will be twelve on 2/2/12. His response was

"ya. it means that there is an unlimited space in between every number."

</comment><comment><USER5> If the 12yo in question knows a bit of programming, a much simpler thing to explain would be the Halting problem, both the statement and the proof.

The bulk of Godel's proof is introducing recursive functions and the "godelization", which means mapping formulas to natural numbers and functions to arithmetic/first order expressions. This all comes for free if you know any programming language; if you don't like natural numbers, you can use strings (the source code itself and its manipulations).

From there, the diagonalization used in the Halting problem proof is the same used in Godel's theorem. In fact, the two theorems are intimately connected, essentially by the statements "you can write a first-order proof verifier in a programming language", and "you can write a computable function as a first- order arithmetic formula".

<comment><USER6> Indeed, the proof of the halting problem is much easier to sketch than the proof of Godel's incompleteness theorem (which the OP doesn't even attempt). So here he goes: a proof sketch of the halting problem for 12 year old programmers.

Suppose that somebody wrote us a program that can check whether another program will loop indefinitely or eventually halt when run on a particular input:

        bool halts(string program, string input){
           // halting checking code that checks
           // whether program's main function
           // halts when given input
           // returns true or false
        }

For example:

        string program =
          "void main(string foo){" +
          "  if(foo[0] == 'a'){ return; }" +
          "  else{ while(true){} }" +
          "}";

        halts(program, "abc") // returns true
        halts(program, "bar") // returns false

Now we can write the following program:

        bool halts(string program, string input){
           // same halting checking code as above
        }

        void main(string program){
          if(halts(program, program)){
            while(true){ }
          }
        }

Note that this is a perfectly valid program. halts() is supposed to work on _any_ program, including a program that happens to contain the source code of halts(). We can just reuse the code that the person gave us and copy-paste it here.

Now the question is: what will our halts() function say about this program, when given its own code as input? In other words: what will the following code print?

        bool halts(string program, string input){
           // same halting checking code as above
        }

        void main(){
          string program =
            "bool halts(string program, string input){" +
            "   // same halting checking code as above" +
            "}" +
            "void main(string program){" +
            "  if(halts(program, program)){" +
            "    while(true){ }" +
            "  }" +
            "}";

          print(halts(program,program));
        }

There are just 2 possibilities: either this program prints true, or this program prints false (if this program never terminates then halts() has a bug).

Case 1: suppose halts(program,program) returns true.

If the halts function is working correctly, that means that when we actually run the code in `program` with `program` as its input, it will halt. But now lets see what actually happens. When we run the main() function in `program` with `program` as its input, it first checks `if(halts(program,program))`. Well, we already assumed that halts returns true, so control flow will go inside the if block to the infinite loop. But that means that halts lied to us!

Case 2: suppose that halts(program,program) returns false.

Now a similar argument holds. run the code in `program` with `program` as its input, the condition of the if statement will be false, and the main function will terminate. So even though halts(program,program) returns false, the program actually terminates. It lied again!

As you can see, no matter what halts returns, it cannot tell the truth about the program we constructed. Hence it is impossible to fill in the missing code in halts() so that it will work correctly.

</comment></comment><comment><USER7> This is my layman's understanding of Godel's incompleteness theorems: Any set of axioms powerful enough to decide all its theorems will always have inconsistencies in its theorems (e.g. "if true then false"). To be consistent, the set of axioms must be incomplete (some of its theorems are undecidable).

The following sentences have some of the 'flavor' of Godel's theorems:

"This sentence is false." →if true, then false.

"These are not words." →if true, then irreconcilable with its own truth.

<comment><USER8> Thank god-you are one of the rare individuals who can use the English language to explain a complex idea. The hideous bias I have encountered in the "hi tech" world is because my mind works like yours and I have always found your talent to be rare gem. Why anyone would think the reduction of complexity into simple terms means putting it into "12 year old" terms is beyond me. So I remain an exile.

</comment></comment><comment><USER9> This is a great explanation. There are a few things that more emphasis should have been placed on. In going over what an axiom is he should have noted that Godel's work only applies to theories which have a formal axiomatic basis and that the axioms are strong enough to encode the natural numbers enough to do certain arithmetic ops e.g. statements in the theory can be proven using induction. And maybe a bit more emphasis should have been placed on the fact that it is possible for a theory to be proven complete and consistent outside itself.

So for example, in line with the first theorem you can algorithmically verify/decide all statements in a subset of Euclidean Geometry (the subset which does not deal well with circles). And in the second part you can have theories which can verify themselves. Or that it is possible to prove a theory complete and consistent as long as you can find a suitably powerful model outside of it.

</comment><comment><USER10> To be clear this is an explanation of the _consequences_ of Gödel's Incompleteness Theorem

<comment><USER11> Exactly. An "explain like I'm twelve" for Godel's Incompleteness Theorum itself would revolve around the idea of self-referential statements (such as 'the set of all sets which don't contain themselves', or 'the barber of Seville shaves everybody who doesn't shave themselves').

In my understanding, Godel created a system that mapped statements to numbers, and then looked at the numbers that represented statements like 'this statement is provable' and found a way to show that the equivalent number had a property that wasn't provable.

<comment><USER12> Or to put another way ..

reducing a holy book to logic analysis of text still produces something not reliable..

</comment></comment></comment><comment><USER13> I don't think this explanation would really work on a 12 year old. I doubt it will work on most adults, who have been through college, but maybe that's just me.

By the way, if you're interested in learning actual proofs of Godel's Theorems, you should take a look at this book: [http://www.amazon.com/Introduction-G%25f6dels-Cambridge- Intr...](http://www.amazon.com/Introduction-G%25f6dels-Cambridge- Introductions- Philosophy/dp/0521674530/ref=sr_1_1?ie=UTF8&qid=1327223816&sr=8-1)

I haven't gone through all of it, but I've read much of the beginning. It actually starts off with easy proofs of Godel's Theorem, based much more on Computer Science explanations than Mathematical Logic.

<comment><USER14> Haven't read that one, but I try to re-read Nagel and Newman's at least once a year: [http://www.amazon.com/Gödels-Proof-Ernest- Nagel/dp/081475837...](http://www.amazon.com/Gödels-Proof-Ernest- Nagel/dp/0814758371)

One thing I love about N&N is that it's short (160 pages) and the paperback is cheap ($7.65) so that I have no compunctions in lending it out.

<comment><USER13> Yes, I've read that one as well. It was a while ago, but from what I remember, it was higher-level than the Smith book. The Smith book is basically a normal mathematics curriculum book, _not_ a "pop science" book (not to say that N&N is), which works out theorem after theorem to get to Godel's proof. Also, it starts off with computer-science proofs instead of the original Godel proofs, which many in this audience will probably prefer.

</comment></comment></comment><comment><USER15> I remember a joke from college that went something like this: There was this mathematics professor that used to tell his students that if they failed at proving a conjecture they should try to prove the opposite, and if they couldn't do that either they should quit mathematics. He had to stop saying that after Gödel published his paper. :)

I haven't studied Gödel's proof and have to admit I would probably have to brush up quite a bit on my maths to be able to, but to me this simple joke offers a more pedagogical and perhaps more meaningful understanding of Gödel's (first) incompleteness theorem.

</comment><comment><USER16> Am i wrong or does 'Well here's what Godel proved: There's no way to really know whether or not any theory is consistent.' completely ignore Gödel's completeness theorem for first order logic.

<comment><USER17> The Completeness Theorem (in one of its equivalent forms) says that every consistent first-order theory has a model, linking syntax and semantics. It doesn't tell you any thing about how you would go about justifying that a theory is consistent.

People hoped that some logical system capable of formalizing real mathematics would be able to justify its own consistency. Godel's Incompleteness Theorem (and stronger, related results) imply that any system capable of formalizing real mathematics (or even a very weak subset of it) can not justify its own consistency, requiring an appeal to a stronger system. Obviously, that raises the obvious question of why that stronger system is consistent. There are constructive proofs (due to Godel himself, Gentzen, and others) of the consistency of Peano Arithmetic, but by the Incompleteness Theorem they must all be non-finitary in some fashion, no matter how slight.

However, there are some limits to this understanding of Godel's Incompleteness Theorem. There are theories that are strong enough to prove (and perhaps more importantly, state) their own consistency but not strong enough to formalize diagonalization. If PA is consistent, then there is a theory that can state and prove its own consistency as well as the consistency of PA. The trick is that provability can be formalized on the basis that subtraction and division are total functions, whereas diagonalization requires addition and multiplication to be total functions. These theories can prove that subtraction and division are total functions, but not addition and multiplication.

</comment></comment><comment><USER18> Another great read, if you haven't already, is Brian Raiter's "Albert Einstein's Theory of Relativity: In Words of Four Letters or Less" is also a great read.

<http://www.muppetlabs.com/~breadbox/txt/al.html>

</comment><comment><USER19> i'm not a mathematician, but his final point about the continuum hypothesis seemed odd to me. the CH is "outside" ZF, but that just means (afaik) that it contains some extra "information" that is not in ZF. adding it to ZF doesn't force any kind of contradiction, in the way that adding "this system is consistent" would. so CH is (just) an example of an independent axiom - <USER2> doesn't illuminate what is so weird about the completeness theorem.

(mathematicians: is that right?)

<comment><USER20> I think the CH was used just to provide an example of an undecidable statement, not actually demonstrate something weird about the incompleteness theorem. Since the CH cannot be proven to be true or false within ZF (or ZFC), then you are correct, appending it would just provide an addition axiom.

<comment><USER21> So it is a weird example, since it NOT an example of a statement that is undecidable in every model.

<comment><USER17> This is not a weird example for that reason. For a given model, every statement is either true or false. Godel's Completeness Theorem says that a first-order theory is consistent if and only if it is true in some model. Therefore, for every undecidable statement there will be a model where it is true and a model where it is false.

These models can look very strange. For example, if ZF is consistent, then by the Second Incompleteness Theorem so is ZF + "ZF is inconsistent". By the Completeness Theorem, a model for this theory must exist. In this model ZF is inconsistent, so there is a 'proof' of a contradiction from the axioms of ZF. However, since we have assumed the consistency of ZF, such a 'proof' must necessarily involve nonstandard integers.

</comment></comment></comment></comment><comment><USER22> Now someone please explain Skolem's paradox to a 12 year old.

<comment><USER21> It depends on whether the meaning of "exists" is, I think. By analogy to the finite universe (always dangerous in logic), it is like saying "we live in a sphere of diameter 4. We have proven (due some hypothetical variation of relativity) that all matter in the universe will never be able to move more than distance 1 from the original center of our existence. An object of length 3 can be mathematically described, but is theoretically impossible to construct." Or something.

</comment></comment><comment><USER23> One of the best - easiest to understand - explanations I have seen anywhere for Gödel's theorem.

</comment><comment><USER8> i have an advanced graduate degree & am not 12 years old. The guy on reddit with his explanation was good reading. Now-fr the interesting part-it's people who can understand the theorem AND explain it to a third party are the really RARE people. Putting complexity into simple terms is what takes the real talent. Amen</comment>


Operating Systems: From 0 to 1 - <AUTHOR> https://tuhdo.github.io/os01/ <comment><USER2> tuhdo, can you say more about how the process works to convert your book from lyx text source to pdf? Since the current pdf seems to have particular formatting added to the source text (eg, terms not emphasized in remaining.txt are italicized in the pdf), it's a little tricky to tell. Is the raw lyx file where the formatting rules live? Does the lyx file store its text source in text files, but its formatting rules in binary?

</comment><comment><USER3> From the book:

"If a programmer writes software for a living, he should better be specialized in one or two problem domains outside of software if he does not want his job taken by domain experts who learn programming in their spare time."

Seems a bizarre sentiment, but after reading this sentence, I feel like I really wanna donate some money to the guy. If he gives a way I will surely do.

<comment><USER4> Can you explain more what inspired you in this sentence or are you still thinking it's bizarre? And if you do still think it's bizarre why would that convince you to donate?

<comment><USER5> not OP, but one thing we as developers should recognize is that programming itself is likely to become merely a skill like operating a spreadsheet or typing. In much the same way, writing was once a skill available (or at least, practiced) by a very small subset of people, and the spread of literacy made the job of "scribe" largely irrelevant over time. Children today are learning how to program—perhaps not yet in the numbers we might have imagined, but a growing number. As they grow up, they are not going to pursue jobs as "programmers" or "developers", any more than I would pursue a job in a typing pool. They will merely incorporate this skill into whatever role they end up in.

Those best suited to compete in that scenario are going to have deep experience in some area where programming is an applied skill, not an end unto itself.

<comment><USER6> While a agree to some extent and have even explored the idea of how my programming skills could be augmented with other non-programming jobs I still feel that for the foreseeable future we will have programmers.

I see lots of jobs being done by non-programmers that would be done much much better had that person been a programmer. The future will undoubtedly be full of people in traditionally non-programming jobs with programming skills. But we should not trivialize the systems that allow this to happen. While most programmers work very high in the stack there are many very deep layers that sit below that will require a army of programmers to keep going and keep innovating so more productivity can be had at the higher layers.

As an example I feel people often trivialize one or two liners programs, or short examples that seem to do so much for such a few terms. But even those simple examples are backed by sometimes 10 of thousands of lines of codes. A wave of a hand, and a bark of spoken command to a computer will -- at least with today's software and hardware -- never end up producing something new and innovated that will be widely used.

To get where you are suggesting many things have to change. And it's not all software. If you even take a cursory glance at what it takes today to bootstrap a operating system -- you would then see how complicated things get. For the future I feel you are envisioning the hardware will have to be worked along with software to make things much much much more modular than they are. More standardised terms to describe things and more finite building blocks will need to be made. In fact the closest thing I could get your future vision with today's technology is FPGAs and it is no trivial task to do anything useful with a hardware described language.

tl;dr We have not _solved_ computers or software, therefor; a army of programmers will be required for the foreseeable future.

<comment><USER5> I don't think that day is as far off as you seem to. Yes, there are some kinds of programming which require deep expertise in programming itself, but these jobs are far from the majority.

If you've ever read Vinge's _Deepness in the Sky_, recall that the protagonists occupation for a period of time was that of a code archeologist, attempting to collect, categorize, and understand code that was centuries (or was it millenia?) old... We may be a ways off from that, but I don't think its far from the truth of the future.

</comment></comment></comment></comment></comment><comment><USER7> This looks great!

I would also like to recommend another free resource that might be a good complement(theory vs implementation) to this:

"Operating Systems: Three Easy Pieces"

available online at:

[http://pages.cs.wisc.edu/~remzi/OSTEP/](http://pages.cs.wisc.edu/~remzi/OSTEP/)

<comment><USER8> I haven't yet finished this book, but this is very good book imo. Can recommend.

</comment></comment><comment><USER9> Looks very nice so far. One minor nitpick - there should definitely be a chapter on inter-process communication, it's an important part of operating systems.

</comment><comment><USER10> Every time an OS book (about weekly) is posted on HN, I immediately want to jump all over it but I gently remind myself to finish: CMU's Computer System's from a programmer's perspective and Elements of computing (nand2tetris).

<comment><USER11> It seems you've already decided that these are worth reading, but in case you want some motivation, I had CS:APP as my textbook last term and I thought it was quite nice. I also worked through TECS several years ago and it was also a great resource. CS:APP is quite dry but by the end of the course I was able to write a real memory manager in C, which was super fun! If you're ever looking for an internet book reading buddy, I also need motivation. I worked through TECS with a friend over a few weeks and found it very useful to have someone else seeing and working through the same problems.

Good luck!

<comment><USER12> TECS? I would like to have online buddy to do this self-learning courses. Most of my projects fizzled due to lack of accountability.

<comment><USER11> TECS is The Elements of Computing System. Feel free to send me an email!

</comment></comment></comment></comment><comment><USER13> For those of you that have read, or at least skimmed, this, how does it compare to the Minix book? ( _which was a joy to read!_ )

</comment><comment><USER14> How much time would it approximately take to work through this?

</comment><comment><USER15> Seems to be for a x86 operating system. I'd have preferred some other architecture because so much of OSdev for x86 that I remember was working around quirks of the architecture (A20 gate etc.). I guess it's a valuable lesson but I'd really enjoy a fork of the book for the hardware you find in a Beagle Bone or Pi3 or something. Maybe this could be crowdfunded if the x86 version is popular?

<comment><AUTHOR> Author here. Yes, it's a x86 operating system. However, rather than getting around A20, it focused on protected mode instead.

The book not only teaches x86, but how to use the official resources from the hardware manufacturer to write the OS. In sum, a reader when reaching part 3 for writing the OS, he will need to use the official document, in this case, the "System Programming Guide" manual from Intel to write C code that complies with the documents. Once he learned how to do so, learning other platforms will be much easier given how complex x86 is.

<comment><USER16> > Author here. Yes, it's a x86 operating system. However, rather than getting > around A20, it focused on protected mode instead.

You still have to open the A20 gate in the bootloader if you want to access a memory adress that has bit 20 (counting from 0) be set to 1 (you probably want) - even if you switch to protected mode. The only exception is if you boot from UEFI instead of BIOS - in this case the A20 gate is already set. But the book uses BIOS as far as I see it.

<comment><AUTHOR> In the Volume 3, it is said that:

"In protected mode, the IA-32 architecture provides a normal physical address space of 4 GBytes (2 32 bytes). This is the address space that the processor can address on its address bus. This address space is flat (unsegmented), with addresses ranging continuously from 0 to FFFFFFFFH. This physical address space can be mapped to read- write memory, read-only memory, and memory mapped I/O. The memory mapping facilities described in this chapter can be used to divide this physical memory up into segments and/or pages."

It correlates to my experience of developing in protected mode in QEMU. Once entered protected mode, I can access to any address above 0x10000 without being wrapped around. When I was writing my first kernel ([https://github.com/tuhdo/os-study](https://github.com/tuhdo/os-study)) in real-mode, indeed A20 must be enabled.

<comment><USER17> The A20 gate would affect both real and protected mode, so to be truely compliant, you should be opening it even for a protected mode OS. It was originally a purely hardware hack forcing an address line(A20, or the 21st address line) to stay low, thus "wrapping" addresses from 1mb-2mb to 0-1mb, so it would have affected real or protected mode identically. On modern hardware, there is a chance that A20 is (against the accepted spec) default open, or possible not implemented.

<comment><USER16> > On modern hardware, there is a chance that A20 is (against the accepted > spec) default open, or possible not implemented.

To nitpick on this a little bit (consider it as a polite supplement):

In Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3 (3A, 3B, 3C & 3D): System Programming Guide

in section

126.96.36.199 External Signal Compatibility

one can read (emphasis by me):

"A20M# pin — On an IA-32 processor, the A20M# pin is typically provided for compatibility with the Intel 286 processor. Asserting this pin causes bit 20 of the physical address to be masked (forced to zero) for all external bus memory accesses. Processors supporting Intel Hyper-Threading Technology provide one A20M# pin, which affects the operation of both logical processors within the physical processor.

The functionality of A20M# is used primarily by older operating systems and not used by modern operating systems. _On newer Intel 64 processors, A20M# may be absent._ ".

TLDR: The accepted spec is that A20M# might not exist.

<comment><USER17> fair point, I hadn't bothered to look more, but it's still true that A20(when implemented) gates both real and protected modes, and therefore "ignoring it to focus on protected mode" is invalid

</comment></comment></comment></comment></comment></comment></comment><comment><USER18> It's a from-first-principles guide to building an OS.

From the title, I had mistakenly assumed it was about the first OS ever.

<comment><USER19> Like almost everything in Computer science there would be no clear definition of first OS ever. There used to be monitor programs and schedulers before they iteratively evolved into OS programs. Just like, programming languages, servers, 'cloud'... There seldom is a first ever something in our field.

<comment><USER20> Im curious what "monitor programs" means here in this context?

The first OS was OS/360 at IBM in 1964.

<comment><USER21> OS/360 was not the first OS. Quite a number of operating systems came before it.

Examples of earlier operating systems include SHARE Operating System (SOS), first version in 1959, for the IBM 709 mainframe; which in turn was itself was based on an earlier operating system, GM-NAA I/O, first version in 1956.

A very notable pre-OS/360 operating system was MIT's CTSS operating system, the first timesharing OS, first version in 1961 for the IBM 7094. The first versions of OS/360, by contrast, notably lacked timesharing – that was initially provided by alternative IBM operating systems (TSS/360 was the official answer and CP/CMS, which later became VM/CMS, the principal unofficial one); OS/360 only gained timesharing support itself when TSO was released in 1971.

</comment></comment></comment></comment><comment><USER22> I have on my list to read something along the lines like this, but this seems incomplete. Does anyone have anything similar?

<comment><USER23> This is what I'm planning to read as soon as I've learned assembly: [http://www.brokenthorn.com/Resources/OSDevIndex.html](http://www.brokenthorn.com/Resources/OSDevIndex.html)

<comment><AUTHOR> I graduated from that guide :) You can see the repo here, written entirely in NASM: [https://github.com/tuhdo/os-study](https://github.com/tuhdo/os-study)

The problem is that the guide is out of date in terms of toolchain, and you need to figure out many things by yourself, especially if you want to develop on Linux. My book helps you to understand how to learn and write x86 with Intel manuals (this is really important!), understand how to craft a custom ELF binary that is debuggable on bare metal, which in turn requires you to understand a bit of how debugger works.

Once you get gdb working, it is much easier to learn how to write an operating system.

<comment><USER23> Oh, good to know! I'll keep that in mind and keep a bookmark of your book and your implementation. Actually, I wanted to start writing an OS by following the BrokenThorn tutorial and was quite naive. After reading some pages it came to me that I don't know much assembly and so I started learning from Jeff Duntemanns Assembly book [1]. As far as I can see, your book also teaches the basics of assembly, it seems more friendly to beginners. Maybe it will be a better start for me. Thanks for putting in the hard work!

[1] [http://www.duntemann.com/assembly.html](http://www.duntemann.com/assembly.html)

</comment></comment></comment></comment><comment><USER24> Well this has got to be one of the more ambitious things I've seen on HN. I wonder if the guy behind SkyOS is still doing operating systems. [http://www.skyos.org/](http://www.skyos.org/)

<comment><USER16> > I wonder if the guy behind SkyOS is still doing operating systems. > [http://www.skyos.org/](http://www.skyos.org/)

No, he (Robert Szeleney, [http://www.skyos.org/?q=node/411](http://www.skyos.org/?q=node/411)) doesn't. He (together with Heiko Hufnagl) founded a studio for creating software and games for mobile devices:

> > [https://en.wikipedia.org/wiki/Djinnworks](https://en.wikipedia.org/wiki/Djinnworks)

> [http://djinnworks.at/about-new/](http://djinnworks.at/about-new/)

</comment></comment><comment><USER25> I will read your book....and thanks for such a book

</comment><comment><USER26> The hallmark of a Good book is that it should leave you wanting more. That's what the book is all about.

<comment><USER12> Have you read the book?

</comment></comment><comment><USER27> On pg 38: _Field Gate Programmable Array (FPGA)_

Surely: _Field Programmable Gate Array (FPGA)_ ?

<comment><AUTHOR> Thanks. I will fixed it.

</comment></comment><comment><USER28> The grammar makes that book fairly painful to read :-|

<comment><AUTHOR> Hi, I would love to hear your feedback. It is the style or the correctness? I am really appreciate if you can show me the few incorrect usages of the grammar.

<comment><USER12> I can tell you're not native. Have the book proofread by someone.

<comment><AUTHOR> Yes, I'm not native. For that reason I tried to use simple grammar and sentences, and did go through paragraph by paragraph through a grammar checker until the end of chapter 4. I will try to improve it gradually.

<comment><USER29> It is better to proof read for correctness. I myself want to point out few grammatical stuffs and looking for the source in Github. You can simple create a repo or add the source text to the current repo, so that people can easily fix these issues for you by giving pull requests.

You don't want people judging this excellent book based on few language quirks here and there.

<comment><AUTHOR> Thanks. I will upload the source soon. As it is written in Lyx, not sure everyone will find it comfortable though. You can always open an issue in the meantime though.

<comment><USER30> Just curious why you chose Lyx and not Org, for example. I still have your "emacs mini manual" open in my browser all the time, so I'm sure you feel natural in org-mode too.

<comment><AUTHOR> Well, Org is suitable for small notes. But for the scope of this book, it's difficult to make Org work for such a complex layout (largely because I don't want to mess with the CSS).

I used Lyx because it enabled me to focus on the content without all the markup text. Writing Latex in Emacs can reduce the distraction, but not enough. I just wanted to focus on the content at the time. Learning Latex is difficult enough, learning how to use the major mode at the same time doubles the difficulty.

Obviously, I still use Emacs daily for writing code and other things. Just not for writing book.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER31> Nice job man!</comment>


Tardigrades turn into glass when they dry out - <AUTHOR> http://www.sciencealert.com/water-bears-turn-into-glass-when-they-dry-out <comment><USER2> For those needing to look up what Tardigrades are:

From Wikipedia: [https://en.wikipedia.org/wiki/Tardigrade](https://en.wikipedia.org/wiki/Tardigrade)

> Tardigrades are notable for being perhaps the most durable of known > organisms; they are able to survive extreme conditions that would be rapidly > fatal to nearly all other known life forms. They can withstand temperature > ranges from −272.222 °C (−458.000 °F) to 149 °C (300 °F),[7] pressures about > six times greater than those found in the deepest ocean trenches, ionizing > radiation at doses hundreds of times higher than the lethal dose for a > human, and the vacuum of outer space.[8] They can go without food or water > for more than 10 years, drying out to the point where they are 3% or less > water, only to rehydrate, forage, and reproduce.

<comment><USER3> It's frustrating that Wikipedia editors ignore sig figs. [7] is a wired.com source which quotes 458F (3 sig figs) and thus should be converted to 272C. The quoted 300F is even more suspect, since it's a nicely rounded number.

<comment><USER4> Considering that -272 C is very close to absolute zero, it makes perfect sense. For example, 0.1 K and 0.5 K are both written as -273 C, but the latter is five times as hot as the former. For best consistency, we ought to use logarithmic Kelvins.

<comment><USER5> I don't really disagree, but that would make for a rather perverse unit, given that inverse temperatures are already on a logarithm scale relative to the probabilities of microscopic states.

<comment><USER6> Logarithms are like violence—if it's not flat yet, you need to use more.

</comment></comment></comment></comment></comment><comment><USER7> It is fortunate these things are so small, if they were the size of a small dog they would scare the crap out of me. An unkillable eating machine.

<comment> guard-of-terra Without spine they won't be able to function at that size. Gravitation is mean bitch - weight grows as x^3, but muscular power only as x^2. Mammals are probably the best you can do in "very large" form factor.

Indeed, even at their present size they are called "slow steppers".

<comment><USER8> On the other hand, actual biology: [https://en.wikipedia.org/wiki/Coconut_crab](https://en.wikipedia.org/wiki/Coconut_crab) (and re: the "mammals" comment: [https://en.wikipedia.org/wiki/Argentinosaurus](https://en.wikipedia.org/wiki/Argentinosaurus))

<comment><AUTHOR> "Video of the most likely way Argentinosaurus walked" -> _Very_ carefully.

</comment></comment></comment></comment><comment><USER9> So why/how does an animal evolve to survive hard vacuum and lethal ionizing radiation when you can't experience those conditions here (on Earth)?

<comment><USER10> This is an argument for panspermia according to Neil deGrasse Tyson. (Real Time with Bill Maher, S13E29)

<comment><USER11> I was going to say the same thing. Such a hardy species I would think would be the product of an incredible amount of evolutionary progress. How do they fit in with the rest of the living species taxonomy?

<comment><USER12> Don't get too excited - the Wikipedia article (very good) explores their genome and taxonomy. Fossilised records hard to come by but cambrian and Cretaceous records have been found. So probably boringly terrestrial

<comment><USER13> Or it could simply mean that they came to Earth a long time ago.

<comment><USER14> Sure, but as of now, there is no positive indication they are extraterrestrial. They fit into the species cladogram, they don't seem to suddenly appear as a time anomaly, they just seem like extremely tough little guys.

</comment></comment></comment></comment></comment></comment><comment><USER15> > capable of surviving ... prolonged desiccation and near-100 percent water > loss

Aren't they the same thing?

<comment><USER16> One is prolonged, the other is intense.

</comment></comment><comment><USER17> So, any chance of this particular kind of auto-vitrification could work as a preservation method for human cells, alternative to cryopreservation or plastination?

</comment><comment><USER18> Url changed from [http://www.hexapolis.com/2015/12/23/new-research-shows- that-...](http://www.hexapolis.com/2015/12/23/new-research-shows-that-water- bears-turn-into-glass-when-drying-out/), which points to this.

</comment><comment><USER19> The title reads like a Radio Yerevan joke: they don't "turn into", they are "covered in", and it's not glass, it's protein.

<comment><USER20> It's not glass, but it may be _a_ glass. [https://en.m.wikipedia.org/wiki/Glass](https://en.m.wikipedia.org/wiki/Glass):

 _" Scientifically, the term "glass" is often defined in a broader sense, encompassing every solid that possesses a non-crystalline (that is, amorphous) structure at the atomic scale and that exhibits a glass transition when heated towards the liquid state."_

Polystyrene is a glass, for example ([https://en.m.wikipedia.org/wiki/Glass_transition](https://en.m.wikipedia.org/wiki/Glass_transition))

</comment></comment><comment><USER21> Tardigrades rule!</comment>


Pain-free way of tackling dental decay reverses acid damage and re-builds teeth - <AUTHOR> http://www.sciencedaily.com/releases/2011/08/110823115402.htm <comment><USER2> If this actually works as advertised, I hope it makes it to market as fast as possible. I'm pretty much done with the days of having new cavities, but I have composite fillings for all the cavities I did have, and ten years down the line they're starting to go bad. It's incredibly frustrating to have a dentist tell you you need to have an already-filled tooth re-drilled because the composite isn't sealing the cavity anymore and decay has set in around the edges where no amount of brushing could have prevented it. With any luck the current generation will be the last to suffer this fate.</comment>


Former Microsoft Chief to Buy Clippers for $2 Billion - <AUTHOR> http://time.com/139577/former-microsoft-ceo-buys-clippers-2-billion/

<comment><AUTHOR> I am not US, but based on this comment: "The Clippers sale would easily beat the previous high price for an NBA team—the Milwaukee Bucks at $550 million earlier this year." I have to ask WHY?

10% of his worth is a huge amount to pay for something where your paying a premium, and its not likely to go up in value compared to other things he could buy.

Maybe its the billionaire version of a mid life crisis and convertible?</comment>


The Case for Not Being Born - <AUTHOR> https://www.newyorker.com/culture/persons-of-interest/the-case-for-not-being-born <comment><USER3> Anti-natalism is a belief that natural selection inevitably selects against, and thus a compassionate person who recognizes the truth of the utilitarian calculus of someone like Benatar would recognize a few things.

1) There is zero chance of convincing everyone to voluntarily cease reproduction

2) Those who you convince on the grounds of compassion to cease reproduction, are, by this very decision, proving themselves as among the best suited to be parents... thus the only goal that is achieved is that the quality of parents is diminished.

Given that, the true goals of anti-natalism could only be achieved through the involuntary destruction of the human race... supervillain territory.

Yet, given the likelihood that natural selection would end up restarting the process, even if destruction were achieved, it seems that perhaps a better approach for someone with this goal system would be to play the game of civilization, see how far our powers can take us, and how much of this universe or multiverse we can reorganize according to our values...

And one of those values could be the prevention of new cascades of natural selection leading to uncontrolled consciousness with the capacity for suffering.

<comment><USER4> > Those who you convince on the grounds of compassion to cease reproduction...

Compassion is an emotion, not rational "grounds" for a decision.

> ...the best suited to be parents...

Or they just live in a particularly unsuitable environment.

Which brings up a good point. The case for "nobody should have children" is a particularly hard one to make because it presumes that there is no good life for any human ever. A more middle ground would be "there is no good life for some, but there is at least arguably good life for others".

So what does "no good life" look like? Who has it "worst"? Should we say sub- Saharan Africans should stop having kids? Lower caste Indians? Palestinians? Jews in early 20th century Germany?

Isn't much of the middle ground between the status quo and "supervillain territory" fairly close to outright racism and genocidal propaganda?

<comment><USER3> Rationality is the logical and empirical pursuit of a value system. The values are the axioms.

"Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them" \- David Hume

<comment><USER4> Good reason spans generations, cultures, and languages. Passions don't age or translate nearly as well.

Hume's formulation treats reason as a phenomenon existing entirely inside of a mind and subject to individual passions.

</comment></comment></comment></comment><comment><USER5> _Again I saw all the oppressions that are practised under the sun. Look, the tears of the oppressed—with no one to comfort them! On the side of their oppressors there was power—with no one to comfort them. And I thought the dead, who have already died, more fortunate than the living, who are still alive; but better than both is the one who has not yet been, and has not seen the evil deeds that are done under the sun._

Ecclesiastes 4 (NRSV-A)

circa 400 BC

<comment><USER6> > _There is a goal, but no way; but what we call a way is hesitation._

\-- Franz Kafka, "Reflections on Sin, Suffering, Hope, and the True Way"

When it comes to oppression by the insane -- and that's what it is, the desire for power cannot come without insanity -- there is only cowardice.

I once saw a animal documentary, one scene was zebras that had to cross a river because there was no food left on the side of it they were on. The crocodiles were already waiting for their annual feast. The zebras pushed up to the river edge, aware of the crocodiles, hesitated a bit, but once the first few started to go into the river, the rest instantly followed. A few crocodiles would catch a zebra each, but most zebras came to the other side unscathed, the herd lived another year. I still remember how that one zebra that got surrounded and bitten, got itself out of the water again (on the side the zebras came from) while its guts were falling out, collapsed just out of frame, and got dragged back by a crocodile to get eaten. It was probably the lack of video resolution and sound that gave me the impression of that zebra being very stoic, but at any rate it _seemed_ to calmly do what it needed to do. It fought back as much as it could, but it didn't, say, roll its eyes back like a (domesticated) horse might -- none of what I would have expected. It reminded and reminds me of this:

> _I never saw a wild thing sorry for itself. A small bird will drop frozen > dead from a bough without ever having felt sorry for itself._

\-- D. H. Lawrence

What are we doing? We hang around, and when someone makes a run for it, and looks for us to follow, we watch them get eaten and call them dumb or idealistic. We're ungrateful towards those we don't even deserve. We're cowards. And we're not even dealing with crocodiles. One on one, we are dealing with dwarves. Consider a man like Hitler. As a person, he was incredibly weak. Other than children, there is nobody he himself could have harmed. Left to his own devices, he would have just rotted and then imploded. That goes for most powerful people who abuse their power, individually they are a joke. Yet here we are, on mass graves, and already training ourselves to accept worse.

Forget power and war: Each year, how many elderly people freeze to death in the UK? How many children starve each minute in the world? There is just cowardice, obedience to those who deserve no authority, and self-pity of those who deserve no pity.

<comment><USER7> I saw a zebra get caught by two lions. It ran like crazy until they caught it up, one of them standing on its hind legs leaning on the zebra. It then stood completely still for a few seconds before the lions pushed it over and finished it off. I hadn't considered shock as a possible reason but it certainly seemed to have given up.

<comment><USER6> I wasn't talking about zebras in isolation, I was talking about something like this [https://www.youtube.com/watch?v=s8HJ2RJwcJM](https://www.youtube.com/watch?v=s8HJ2RJwcJM) except there were more crocodiles and the zebras were forming less of a line.

Yes, that individual zebra probably knew it was done for the second it was surrounded. Struggling didn't make a difference for itself, it made a difference for everybody else. And if the zebras had just stood there going "you first", they would ALL have died. That's the point. That's how _we_ do, and I don't see anyone debating that main point.

It's not even selfless, it's the difference between thinking in terms of quarterly profits and one's own comfort in one's own lifespan, and destroying the planet and society in the process. If you want to think of it in terms of DNA, if other humans survive then still more genes similar to your own get passed on than if NOBODY survives.

> _Courage is indispensible because in politics not life but the world is at > stake._

\-- Hannah Arendt

Who also often pointed out how many intellectuals have this talent to not see the woods for all the trees, and how talking about serious things with average people is often more fruitful. Chomsky made the same point, though I can't find the quote for him either.

</comment></comment></comment></comment><comment><USER8> Am I the only one? or do some people just have way to much time on their hands for thinking shit like this up. I'd rather live my life than not exist.

<comment><USER9> You probably don't exist, you only think you do.

<comment><USER10> It's true - the universe is made of nothing. Galaxies are mostly empty space. So then you find some matter in the galaxy. Atoms are matter. But atoms are mostly empty space as well. But then you find the nucleus. But protons are mostly empty space as well. But then you find quarks. But quarks are mostly empty space as well. It's empty space all the way down. Nothing actually exists.

<comment><USER11> On the other hand, we can detect atoms, nucleons, quarks, and even, in so called empty space, vacuum fluctuations. Maybe it's more accurate to say nothing doesn't actually exist.

<comment><USER9> That's what you think. There is a great book called "Constructing Quarks". Have a look

</comment></comment></comment></comment></comment><comment><USER12> In these incredibly nihilistic worldviews, what is the framework by which a logical case can be made that something like "suffering" is even to be avoided? Who cares? An individual organism (whatever that even means) may minimize its own suffering, but why should it care about anyone else's?

</comment><comment><USER13> "Better to have loved and lost than never have loved at all."

I'd say it is better to be alive and sometimes suffer than never to have life at all. Life comes with joys and happiness as well as the downs

<comment><USER14> I was dead for 12-billion years before I was born... and it would be hard to say it was "better" than this because there is nothing to compare this with.

anti-natalism is a divide by zero problem.

for the ones of us who are hopeful that we can solve the problems of aging in the next century, there's an option to solve the problem raised in the article: humans keep making the same mistake because by the time they've learned to stop, they're nearly dead already.

I feel for Benatar, but I doubt his motives.

(edits for spelling)

<comment><USER4> > anti-natalism is a divide by zero problem.

True. But this math presumes atheism. If there's an eternal afterlife, 12-billion years is also a "divide-by-zero problem".

So the whole conversation sort of boils down to "is this it?"

<comment><USER14> > If there's an eternal afterlife

there isn't.

> "is this it?"

yeah.. until we can merge our brains to make new brains, we're just gonna be stuck merging our genitals to make new brains.

biological systems are what they are.

</comment></comment></comment></comment><comment><USER15> This is negative utilitarianism, right? For instance, if you could press a button and wipe out humanity without (much) suffering, would you do it? Personally I'd have a quick reminisce then all slam it.

But practically, this isn't an option (yet). Nor is voluntary extinction. The people susceptible to this message or any such message (better for environment; your group of people is bad and shouldn't continue; life is more fun without kids) are more likely to be the kind of people that would contribute to a positive next generation.

The bulk of growth that'll receive and cause suffering is from people that won't ever listen or heed such a message. Hence anti natalism will only increase suffering in the world.

<comment><USER10> > Personally I'd have a quick reminisce then all slam it.

What the heck? You'd destroy our entire species to "spare" those that don't have it good?

<comment><USER16> Wouldn't it be easier to eliminate yourself from the spectacle of watching the less fortunate. Because this type of thought process only comes from the "club seats" of world society. If you read actual studies on happiness, what the first world world categorize as fairly destitute aren't as miserable as we imagine. While we, with our fat bank accounts and our ever quest of acquisition, just aren't as happy as we seem to think we deserve. To quote The Big Lebowsky, "Fucking Nihilists".

</comment></comment></comment><comment><USER17> I had a vasectomy two years ago at the age of 29. I don't know if I'm an anti- natalist, as I try not to wax philosophical about my personal choices and feelings. People are diverse. I am close friends with people with kids, and sometimes I go to their softball games. I'm happy to see the kids' triumphs and sad to see them struggle, but these feelings must pale in comparison to the roller coaster a parent must feel.

Not to mention I have this Catcher in the Rye mentality of wishing childlike innocence was forever preserved. Which I know won't happen. Then again I'm sad when I see adults with childlike naivety suffer because reality does not discriminate. I've also done my fair share of taking care of old people. They are usually not the wise happy people that I imagine comes with aging - <USER2> are lonely, impatient, anxious, stubborn - basically human but with declining faculties. I'll always be haunted by the image of my grandmother wandering around in the dark, confused, holding a diaper in one hand, with wild hair and unsteady gait.

Watching people eat is also sad. Hunger... oh the humanity. The humanity of everything, really. Life is just suffering punctuated by the briefest moments of relief. I'm not depressed... I don't think.

<comment><USER18> cko, I am not trying to pry into your personal life but I found your comment very noticeable. Was vasectomy a choice you made to remain childless or was the surgery the result of pressures of life that removed any choice. You could have chosen not to undergo the surgery and still remain childless. You can choose to ignore this question if you don't want to answer it.

<comment><USER17> I like the question, no one's ever worded it like that before, but I would say it's a bit of both. That is, I never wanted children and I also didn't want any accidents down the road. And I know if I did have children I'd feel less free. That said, I must say I feel extremely blessed in life in terms of aptitude and finances, however.

</comment></comment></comment><comment><USER19> Hating people and life has always been popular with philosophers. Socrates' last words: "don't forget to sacrifice a rooster to Asklepios". He's saying life is a disease and death the cure, warranting a sacrifice to the god of medicine.

I'm beginning to appreciate Nietzsche, his affirmation of life and embracing its terrors, accepting the world for what it is. Just a pointer for the interested.

</comment><comment><USER20> I'm trying my hardest to understand this, but I'm not seeing the logical 'meat' here. As the article states the vast majority of people are quite happy. And even those in the worst of conditions on this Earth are not all that dissatisfied with their lives. The philosopher's retort against this is essentially, 'No, you're not happy!' Who is he to say? But then the argument he follows his 'no you're not' with what seems to be a surprisingly shallow bit of logic. He claims that various discomforts such as hunger/cold/tiredness/etc are a major and never ending source of discomfort. Let's consider comfort for a minute -- actually let's consider discomfort. Imagine there was a universe that somehow, absolutely no discomfort existed. Would this be a world where people living there felt or experienced their lives to be ones of constant comfort? No, it would be experienced as a world where the very notion of comfort and discomfort simply do not exist. It would be like considering vision in a world where there was no such thing.

His argument also sidesteps the point of progression. Claiming we keep repeating the same mistake is myopic at best. The vast majority of people are freer and more able to pursue their lives as they see fit than most any time in history. And this positive forward progression is a never ending theme. The further back you go, the worse things become. Unless he wants to claim existence was more pleasant thousands of years ago, it's tough to deny this directionality of progression. And to deny the innumerable masses of people that may be able to live in ever greater comfort in the future their existence, because you're upset about some petty discomforts in the present -- that seems, at the minimum, supremely greedy and certainly far away from any sort of vague appeal to utilitarianism that he seems to try to make at times.

</comment><comment><USER21> Interesting quote:

"""His thinking parallels that of the philosopher Thomas Metzinger, who studies consciousness and artificial intelligence; Metzinger espouses digital anti-natalism, arguing that it would be wrong to create artificially conscious computer programs because doing so would increase the amount of suffering in the world."""

<comment><USER22> Great conversation:

[https://www.samharris.org/podcast/item/the-nature-of- conscio...](https://www.samharris.org/podcast/item/the-nature-of- consciousness)

</comment></comment><comment><USER23> _"But compare that with a scenario in which that person never existed—then, the absence of the bad would be good, but the absence of the good wouldn't be bad, because there'd be nobody to be deprived of those good things."_

I'm not convinced that this is asymmetric. You could easily extend the argument to include that the absence of bad wouldn't be good "because there'd be no one to be deprived of the bad things". There are many other examples of this kind of logic in the piece.

Overall, it seems to be a pretty subjective and self-contradictory philosophy, at least the way it is presented and defended (by the person being interviewed) it is.

</comment><comment><USER24> you ever listen to the breaths of someone speaking rather than the tone or content of their speech? it helps to count the i's in someones writing, to see if they're looking but can't really see.

people have children because sex is fun, babies are cute, toddlers are a captive audience, aging is precarious, and legacy is precious. take the fun out of sex with porn, replace babies with pets, develop a captive audience through endless digital information, eliminate the physical risks of aging, allow a permanent legacy on a voluntary basis for every human being.

life is the most precious gift you can give, 1 second of miserable agonizing painful life defeats the infinity of non-existence. this is the wisdom in giving children life. the developed world has gotten soft. but we need that belly fat for the lean winter years to come. 25-30 years from now it will be the people who chose to have 5+ kids in the 2010s that are relevant, not those who bought the forever pill. nature is not a friend technology is an unwilling slave, trust the first or liberate the second and die a fool. human nature is to kill and survive, and technology is concerned with throughput.

what fascinates me about the world is how irrelevant most people are outside of their immediate family. i could fit every person of net worth 100mil+ in a sports stadium. if that's all that matters, we could go on with about 60k people, why are we lugging around 7.5 billion? just convince them to stop having kids and those next 100 years will fly by as the robots fill the gaps. it's like the dried out husk of a chrysalis emerging beautiful from it's final metamorphosis. 7.5 billion shells birthing 60k butterflies.

nah i'm pretty sure having 5+ kids and monitoring their internet access is the right move for virtually every single fertile human being. if you have money? go for 10.

</comment><comment><USER25> Counter argument to antinatalism. Benatar allows that once alive, death is horrible and to be avoided.

Failing to reproduce results in the death of all in the limit.

Therefore I propose that anti-natalism's ship has sailed once there is someone to think of it.

</comment><comment><USER26> I don't disagree with the reasoning: The Earth would be much healthier, there would be no suffering, the "Universe" wouldn't care.

But for good or bad, we humans have an inherent drive to procreate and survive. I think while his question/answer might be correct in a vacuum, it misses the point.

Now that we're already here and can't consciously stop existing, how do we best move forward and maximize collective utility and minimize suffering and our damage to our habitat?

Disclaimer: the environmental effect is my addition, to his psychological effects.

<comment><USER27> If life isn't worth creating, why is it worth preserving? Why not take this to the logical conclusion of voluntary total extinction? Furthermore, how could one even discuss good or bad without a frame of reference?

<comment><USER28> Benetar argues death is often worse than life. It is non-existence that is better than both.

<comment><USER29> Non existence comes after death. Death can be painless. How, then, is death worse than non-existence?

<comment><USER28> These are terms used in a philosophical argument, so you have to be precise about definitions. In this case, non-existence is not possible once life begins. Non-existence is the alternative to creating new life. So , as far as we are concerned, in this context, non-existence is not considered to be what occurs after death.

</comment></comment></comment></comment></comment><comment><USER30> I think the capacity for suffering increases dramatically with the advent of AI. This was referenced in passing in this article, but underplayed. We've talked about "virtual hell" stuff on HN before. I say let's not even create it. I wouldn't know how to stop it if it were created. Then again I don't know how to "stop the progress of science" either (other than, say, ending humanity altogether). I'm uncomfortable even working at a company that uses machine learning.

<comment><USER31> Can you go into more detail on your concerns? I feel like fears over AI are greatly exaggerated. In the real world I feel like we've managed to create some pretty impressive suffering and I'm not sure AI would have that big of an impact (it could even reduce it). Everyone who is concerned about AI seems to be trying to predict the post-singularity world, my guess is that in the near term it will just allow those with power and money to have even more power and money (which is already happening).

What is your idea of virtual hell exactly? By the way, googling virtual hell brought me to this delightful fossil: [http://www.webring.org/l/rd?ring=spooky;id=56;url=http%3A%2F...](http://www.webring.org/l/rd?ring=spooky;id=56;url=http%3A%2F%2Fwww%2Ejust4kidsmagazine%2Ecom%2Fhell%2Fmain%2Ehtml)

<comment><USER32> Not OP, but I don't think the fear is that AI will take over the world and enslave as all. Rather the other way around. Imagine you can create an artificial consciousness. You could then proceed to cause this AI a tremendous amount of suffering, by submitting it only to whatever input it is that it considers unpleasant. This experiment could then be scaled up on a level unprecedented in history, and it would be possible to submit billions and billions of AI:s to effectively eternal torment.

Why? Any reason. Perhaps as revenge on an AI that has acted against your interests, perhaps as a bargaining chip ("if you don't do as I say, I'll create a thousand exact copies of you and torture you"), perhaps just because - because hey, it's not like the world lacks psychos.

[edit]: Ah, I see OP answered while I was typing. Oh well :)

</comment></comment></comment><comment><USER33> Let's assume that humans thus far have caused a net-negative on the earth, through wars, environmental damage, animal extinction, etc.

Let's also assume that humans have the potential to be net-positive. Humans can create environmental restoration projects could potentially prevent an asteroid catastrophe.

So I would argue that humans are still in their infancy. Once we get our act together, (which could take a few more millennia) we will eventually be a blessing to the world.

</comment><comment><USER34> Nothing he writes supports his "theory" that the universe would be better off without sentient life as this is the sole purpose of the universe to exist altogether, so in essence he wants the universe to cease to exist???

Anyways I completely disagree with his premise that life should not happen because of "bad things" in fact life happens not only in spite of but in fact did happen because of "bad things" like the first cell replication!!

</comment><comment><USER35> "The secret to success is being smart enough to play the game well but not so smart you figure the game out."

I've heard many variations on that saying. The most popular contexts I've heard it with are Wall St. and the financial industry and politics. People like the Wolf of Wall St., Donald Trump, Hillary Clinton, etc. would be people who were just smart enough but not too smart. People who are too smart make their money and leave or don't play at all.

Stuff like this makes me wonder if it applies at the evolutionary scale. Add it to your queue of potential Fermi paradox answers. Maybe there aren't any super-intelligent aliens visiting other stars because super-intelligent aliens realize evolution is a meat grinder and opt out.

Personally I don't buy it.

For a long time I've incubated what I call the "uncanny valley hypothesis" about this kind of nihilism. The idea is that between the standard issue human intellect guided by myth (religion, political myth, etc.) and something _beyond_ there is an uncanny valley of nihilism. This would also be called a fitness valley in evolutionary and learning theory terms. Local maxima in fitness landscapes are very often separated by valleys that must be crossed. Things have to get worse before they can reach the other peak.

Secularism repeatedly fails at the civilizational scale because it gets stuck in this valley. Societies try abandoning religion but find themselves denuded of "why" and "ought," eventually retreating back to mythology as a virtual motivator.

What's beyond the uncanny valley? Perhaps something rational, logical, realistic, and with the positive motivation of an ecstatic religious guru. It would be a motivation rooted in some kind of understanding that eludes us, not in raw myth, though I suspect our myths contain little seeds of that understanding here and there.

There have been notions like "extropianism" in the fringe sci-fi space that have attempted to construct such a thing, but they always devolve into woo woo fluff or culty stuff. Makes me think this fitness valley is tougher and deeper than merely recasting myth in terms of science. There is either a missing fundamental understanding or a missing cognitive ability. There's something we don't have that religious and other myths sort of act as brain hacks to lend us or simulate.

I also think Nietzsche saw this but I think he was wrong about how to overcome it. It's not a matter of mere will. Will without "why" and "ought" devolves into robotic non-sentience or psychopathy.

Edit: going back to the Fermi paradox I suppose this fitness valley could be one of the "great filters."

</comment><comment><USER36> Anyone else think that suffering is the means to the end. Eventually through enough suffering, such as climbing a mountain (or building a country) then suffering diminishes. Won't the end game be like Elysium in thousands of years of suffering?

</comment><comment><USER37> interesting idea but i feel like this is an extreme end of a spectrum to a solution of suffering. There are plenty more solutions like giving those who suffer an easy and painless and dogma free way to exit. I think that even knowing that you have an option to leave would be an instant boost to ones psyche. Sort of like running a marathon with an option to quit, vs running a marathon with no options but death. Probably infinite solutions exists in this space if we got rid of dogma.

<comment><USER38> But one of the cases he makes is that everyone suffers - mild things, like being hungry, thirsty, having to use the bathroom, small pains which are pretty much constant once you've hit your 30s. Would you offer those an easy / painless way out? He's also not arguing about ending life once it exists - death is bad too. There's more of that in the article itself.

<comment><USER37> i'd take that with a grain of salt. he can't possibly know what hunger feels like for other people. some people love to use the bathroom, some people love the hunger. some people fast on purpose, be it religious, health, meditation, bio hacking, they do it because it makes them better off. some people suffer on purpose. philosophers probably suffer more than other people and not on purpose :)

</comment></comment></comment><comment><USER39> As surprising and extreme as this argument appears when applied to humans, it's pretty much the default when people feel bad about about our meat animals.

</comment><comment><USER40> If you prefer to listen, he was also on Sam Harris's podcast: [https://soundcloud.com/samharrisorg/107-is-life-actually- wor...](https://soundcloud.com/samharrisorg/107-is-life-actually-worth)

<comment><USER22> I got about 10 minutes into it yesterday and gave up, poorly thought out nonsense imho.

<comment><USER41> Benatar never answered any of Harris counter-arguments. Made absolutely no sense to me.

Being anti-natalist, but stating suicide his morally wrong? If life is so painful that we should not give it to someone, why one should not kill himself?

I think Harris nailed it in the first few minutes when he asked about how Benatar own experience of life could taint his view on this.

<comment><USER42> I haven't heard the podcast, but I can see the argument for being anti- natalist and against suicide. Anti-natalism is ultimately about avoiding human suffering (or any kind of suffering). Even if a suicide is painless, it will still cause suffering for the ones close to that person. Even if someone reaches the conclusion that life is meaningless and not worth living, it is still very difficult to decide to commit suicide for countless reasons, starting with one's instinct of self preservation.

</comment></comment></comment></comment><comment><USER43> It starts with the death of companion animals. Not when you are young and comparatively resilient, but later in adult life when you are personally responsible for all of the decisions and costs, the management of a slow and painful decline. The futile delaying actions, the ugly realizations, the fading away, the lost capacity, the indignities and the pain, and all in an individual fully capable of feeling, but who lacks the ability to comprehend what is happening, or to help resist it. One slowly realizes that this is just a practice run for what will happen to everyone you know, later, and then to you. Ultimately it comes to euthanasia, and one sits there looking down at an animal who is a shadow of his or her previous self, second guessing oneself on degree of suffering, degree of spark and verve remaining. It is rarely a clear-cut choice, as in most companion animals the body fails before the mind. When it is clear, and your companion is dying in front of you, you will rush, and later chew it over for a long time afterwards; did you wait too long, could you have done better?

At some point you will ask yourself: why am I trying to maximize this life span? Why am I playing at balancing capacity against suffering? Why have I not just drawn an end to it? Why does it matter if a dog, a cat, another animal exists until tomorrow? Next year the animal will be gone without trace. In ten thousand years, it is most likely that you will be gone without trace. In a billion years, nothing recognizable will remain of the present state of humanity, regardless of whether there is continuation of intelligence or not. The great span of time before and after cares nothing for a dying companion animal. There is no meaning beyond whatever meaning you give to any of this, and there is a very thin line between that and the belief that there is no meaning at all, the belief that there is no point. If the animal you lived with will be gone, what was the point of it all? If you will be gone, why are you so fixated on being alive now, or tomorrow, or some arbitrary length of time from now?

It starts with companion animals, and it gnaws at you. The first of the cats and dogs you live with as the responsible party, the thinking party, the one motivated to find some meaning in it all, arrive and age to death between your twenties and your forties. That is traumatic at the end, but you find it was only practice, because by the end of that span of time, the first of the people closest to you start to die, in accidents and in the earlier manifestations of age-related disease. The death by aging of companion animals teaches you grief and the search for rationales - meaningless or otherwise - and you will go on to apply those lessons. To your parents, to mentors, to all of those a generation older who suddenly crumple with age, withering into a hospital or last years in a nursing facility. You are drawn into the sorry details of the pain and the futile attempts to hold on for the ones closest to you, a responsible party again. You are left thinking: why all this suffering? Why do we do this? What does it matter that we are alive? The span of a billion years ahead looms large, made stark and empty by the absence of those dying now, no matter how bustling it might in fact prove to be.

Grief and exposure to the slow collapse of aging in others: these are toxins. These are forms of damage. They eat at you. They diminish you, diminish your willingness to engage, to be alive, to go on. I think that this burden, as much as the physical degeneration of age, is why near all people are accepting of an end. The tiredness is in the mind, the weight of unwanted experiences of death by aging and what those experiences have come to mean to the individual. Human nature just doesn't work well under this load. It becomes easy to flip the switch in your view of the world: on the one side there is earnest work to end future suffering by building incrementally better medical technology, while on the other side lies some form of agreement with those who say that sadness and suffering can be cured by ending all life upon this world. Oh, you might recoil from it put so bluntly, but if you accept that existence doesn't matter, then the gentle, kind, persuasive ending of all entities who suffer or might suffer lies at the logical end of that road. It is just a matter of how far along you are today in your considerations of euthanasia and pain. This is the fall into nihilism, driven by the urge to flee from suffering, and the conviction that your own assemblies of meaning are weak and empty in the face of the grief that is past, and the grief that you know lies ahead.

Not all of the costs of the present human condition are visible as lines upon the face.

</comment><comment><USER25> "Mirrors and copulation are abominable, since they both multiply the numbers of men..." Borges

</comment><comment><USER44> A splendid idea. Let's start with the 1% and their children.

</comment><comment><USER45> >An "anti-natalist," he [David Benatar] believes that life is so bad, so painful, that human beings should stop having children for reasons of compassion.

Poor me, I had no idea it was that bad committing to veganism.[1]

[1] [https://archive.org/details/TheSpeciesBarrier35Antinatal](https://archive.org/details/TheSpeciesBarrier35Antinatal)</comment>


How Visa Predicts Divorce - <AUTHOR> http://www.thedailybeast.com/blogs-and-stories/2010-04-06/how-mastercard-predicts-divorce/full/ <comment><USER2> Slightly off-topic: if you post something with a misleading title that you can improve, please do so. This article has no information at all on how Visa predicts divorce, just the third-hand assertion that they do. An Amazon text search within Supercrunchers yields nothing of value, either.

<comment><USER3> Exactly. Why is the word "how" in the title? Here's a choice quote from the article regarding that question:

"Exactly how the credit industry does it—through sophisticated data-mining techniques—is a closely guarded secret. "

Well great! Now the title isn't simply misleading, it's factually inaccurate.

<comment><USER4> "Why is the word 'how' in the title?"

Because TDB raise tens of millions of dollars so they could hire dozens of celebrities and go on Colbert the day they launched, and they're trying to make their money back.

</comment></comment></comment><comment><USER5> I've heard rumors that visa uses its purchase records as a leading indicator to trade in stocks. Having all of these sales records gives them a leading indicator of how a particular retailer is performing, before the company releases any statements, or speaks with analysts. While the concept sounded simple, I'm not sure if I believe this because I had no way of knowing how large of an advantage it would translate into. Has anyone else here heard these kinds of stories about visa or banks? Is there are reason why this kind of thing would be illegal or ineffective?

<comment><USER6> I know of one financial firm that did this. They didn't trade the specific stocks, but they used their credit card data to predict what the Fed would do.

Doing it one stock at a time might raise some eyebrows; it sounds close to insider trading. But it's accepted that people who bet on interest rates will gather lots of data--since every economic indicator you can imagine will have some effect on rates, it's both impossible to be a true "insider" and impossible not to have some degree of insider information.

<comment><USER7> > Doing it one stock at a time might raise some eyebrows; it sounds close to > insider trading.

That's not the definition of "insider trading". Insider trading is you trading on your company's info - the company is free to do so. For example, Google employees can't trade Rackspace on knowledge that Google is about to make a big deal with Rackspace. Google, on the other hand, is free to do so.

From <http://en.wikipedia.org/wiki/Insider_trading>

"In the United States and many other jurisdictions, however, "insiders" are not just limited to corporate officials and major shareholders where illegal insider trading is concerned, but can include any individual who trades shares based on material non-public information in violation of some duty of trust. This duty may be imputed; for example, in many jurisdictions, in cases of where a corporate insider "tips" a friend about non-public information likely to have an effect on the company's share price, the duty the corporate insider owes the company is now imputed to the friend and the friend violates a duty to the company if he or she trades on the basis of this information."

<comment><USER6> The definition of insider trading is alarmingly flexible; it's safer to avoid the appearance of impropriety, since that can still get you convicted.

I wasn't aware that a corporation could trade based on insider knowledge. That seems very unlikely; it would imply that, e.g. Boesky was busted because his fund was organized as a limited partnership. And wouldn't a corporation with one owner be equivalent to that owner in terms of economic interest? Could I just form byrneseyeview Inc. to take advantage of my insider knowledge?

Do you have a source for the statement that corporations can engage in insider trading?

<comment> Tuna-Fish I think you misunderstood his point. Any entity is allowed to trade on information that's legally available to them without violating any duty of trust -- if for example, Google decides to buy rackspace, it is perfectly legal for them to buy call options in front of the announcement to profit from the spike in value caused by the announcement, as no duty of trust is broken.

It would be, however, illegal for employees, shareholders or indeed anyone hearing about Google's intentions about the purchase to buy those options, as they would be breaking their duty of trust to Google by doing so. This holds regardless of the legal status of the entity in question -- a corporate shareholder getting privileged information from Google before the announcement would be just as screwed as an employee.

<comment><USER6> I assumed that a deal with Rackspace meant a purchase of Rackspace products. I agree that you can buy a stock before trying to buy out the company--but you can do that as an individual, too.

But in this case, the company trading on credit card data is clearly analogous to a Google employee, not to Google. They have material information about the prospects of another company, and they use that information to trade.

<comment> Tuna-Fish > But you can do that as an individual, too.

If you are a secretary working for Google, and overhear talks about the buyout and proceed to load yourself on the stock, SEC is going to want to have a word with you.

> I assumed that a deal with Rackspace meant a purchase of Rackspace products.

I don't think this would be illegal either -- with whom would Google break it's duty of trust if they bought half of Rackspace just before announcing a large deal?

> They have material information about the prospects of another company, and > they use that information to trade.

I have material information of the prospects of every company I trade -- I wouldn't trade them without. What turns this into illegal insider trading is receiving that information from a source that is bound by duty of trust to not speak about it. As long as the material information about the prospects of a company does not originate from the company in question, or anyone else bound to not divulge it, it's not insider trading.

When visa data mines credit card transactions, the information so gained can be freely used to whatever purpose without fear from insider trading accusations.

That being said, I do not think it's moral or right -- the laws just were written before large-scale data mining was feasible.

<comment><USER6> If you're an individual, and you plan on buying a company, you can accumulate stock in it first without doing insider trading. That's what I mean when I say you can do that as an individual, too.

 _with whom would Google break it's duty of trust if they bought half of Rackspace just before announcing a large deal?_

This may be accurate. I was under the impression that insider trading referred to possessing and using information that would have a material effect on the stock price. i.e. nobody's "duty of trust" is breached if a cab driver overhears his rider talking about a big deal, but I'd assume that the cab driver could get in trouble for acting on the information. If it's really about trading based on information obtained through a breach of trust, you end up in an odd situation: either _any breach_ makes all trades insider trades (i.e. executive tells information to his secretary, who leaks it to a journalist) or any non-duty-bound link in the chain obviates the trust issue (X tells it to Y who tells it to Z--who is overheard by A, who sells the tip to B, who makes the trade.)

<comment><USER7> > If you're an individual, and you plan on buying a company, you can > accumulate stock in it first without doing insider trading. That's what I > mean when I say you can do that as an individual, too.

Yes, but that's because it's your information that you're buying said company.

However, there are other rules that apply to corporate take-overs. In the US, you have to disclose when you reach a certain ownership level. (And no, you can't avoid that by colluding with other people.)

> This may be accurate. I was under the impression that insider trading > referred to possessing and using information that would have a material > effect on the stock price.

That's why I posted the definition and link.

> i.e. nobody's "duty of trust" is breached if a cab driver overhears his > rider talking about a big deal, but I'd assume that the cab driver could get > in trouble for acting on the information.

Actually, the person who was overheard violated the breach of trust.

> If it's really about trading based on information obtained through a breach > of trust, you end up in an odd situation: either any breach makes all trades > insider trades (i.e. executive tells information to his secretary, who leaks > it to a journalist)

Huh? There's at least one obvious breach of trust in that chain.

Yes, any breach makes the resulting trades insider trades. No, that doesn't imply that all trades involve such breaches.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER8> And if you think your purchases say a lot about you, just wait until somebody gets a hold of your social network data.

(I am willing to bet that "Percentage of friends who divorced" and "Percentage of friends who divorced recently" both whallop any naive demographic predictor of divorce risk you care to name.)

<comment><USER9> Rapleaf is already making progress with this.

<http://www.rapleaf.com/apidoc/person>

</comment></comment><comment><USER10> The comments on that article are telling. The loss of privacy due to inappropriate data mining looks like it may cause at least some people to "go Amish" slowly (now, before I get jumped, I just mean "the avoidance of technology" by "go Amish"; please don't get religious over that).

Personally, reading this article makes me glad I never opened a FaceBook account. I wish gmail was not so all-knowing either; I hate seeing very personally directed ads (anti-depressants when I am sad after reading a break- up mail, for example). Just too creepy.

<comment><USER11> Anybody that breaks up using email in stead of a face-to-face is probably not worth being sad over.

How people part ways says lots about them.

</comment></comment><comment><USER12> Does Visa actually know what you've bought?

"Cardholders who purchased carbon-monoxide detectors, premium birdseed, and felt pads for the bottoms of their chair legs rarely missed a payment."

My bank statements only state where something was bought, not what was bought. I'm not aware of a store that only sells felt pads for bottoms of chairs and premium birdseed.

<comment><USER13> That statement was referring just to Canadian Tire, a retail store that also offers credit cards. I assume the card company can only get that kind of detailed information if you make your Canadian Tire purchase with your Canadian Tire MasterCard.

I once purchased a CO detector at Canadian Tire... maybe I'll bring that up when I apply for my next credit card?

</comment></comment><comment><USER14> The article is badly titled. It explicitly states after the lede that the author was unable to determine how Visa predicts divorce.

</comment><comment><USER15> The Underground History of American Education posits that the main factor at work in the school system is the homogenization of people for the benefit of big business. From a tech perspective, it's easy to understand this motivation; wouldn't it be easier to develop that killer mobile coupon app if everyone had a device with the same capabilities?

Now I'm beginning to wonder if data mining is making the homogenization of people obsolete, if hundreds of profiles can be created, and it suffices business interests to simply be able to categorize you?

<comment><USER16> They don't only want to homogenize the consumer, they want to also homogenize the workers. A fungible workforce is a boon.

</comment></comment><comment><USER17> Off-topic, but related to stuff mentioned in the article.

How do we relate the idea that we own the data a company like Visa collects about us? For example, our buying habits should be "our data." While I understand the need for privacy, people go on to worry about how Visa will use this information, and it's impact on privacy.

Does Visa have the right to use this data to target users?

On one hand, we'd be highly upset if Visa didn't use the data it collects in certain cases, like anti-fraud and tracking odd behavior and warning us of it. But then you have an article like this asking for consumer protection.

I guess the issue here is one of balance: who owns the data? If it's the user, does the company really have the right to use that data to provide a service with it? Even if it's anti-fraud or simple customer service? This isn't something new, either. It's only become easier and easier to do more accurately as technology grows.

On one hand, privacy is important for obvious reasons. On the other hand, generated data is useful and can be used for improving our lives. Just as privacy protects the criminals as well as the innocent, generated data can be used for ill or for good.

I don't think I'm asking anything new. I've always been a person that wants to track everything users do. On sites I create, I want to track everything, know everything. Yes, I want to do this so that I can increase profit. But it's only because I believe that a user who attempts to make a purchase and fails really wanted the product, and it's my job to do everything in my power to get that product to him. I have no desire to steal his data, sell his information, or anything else. But I can see how something like this could be misrepresented or misused.

Just some thoughts I had on this. I'd like to hear other points of view on both sides of the spectrum. I admit I don't know enough, and while my motives are honest, they are in a way profit driven. Customer services is profit driven (Apple doesn't provide the CS it does because it loses money on it!)! And if anyone has any good links on the topic, please share.

<comment><USER18> _"does the company really have the right to use that data to provide a service with it?"_

Whenever I've signed up for a card, it's had a checkbox for whether or not the company is allowed to send you "great offers from our affiliates". Presumably, they'll only use your data if you allow them to. (Whether they hold to that in practice is another matter.)

<comment><USER17> But that has more to do with affiliates. Can Visa do what they want within Visa with your data?

Let's say Google for example, tracking your search habits. Now it uses that data to modify what it displays to you, like ads. This is all internal. They don't release it to the public, or even advertisers.

Even Visa. While it can't release your data, can it use that data to send you information?

</comment></comment></comment><comment><USER19> Factoid: The author, Nicholas Ciarelli, was also known as Nick de Plume -- founder of thinksecret.com.

</comment><comment><USER20> I highly recommend Super Crunchers to anyone who has not yet read it. It is written for the layman, but nonetheless it is highly fascinating and insightful for anyone who is remotely interested in data mining.

<comment><USER21> I found the book very disappointing because it glossed over any real detail.

<comment><USER20> Like I said, its "written for the layman". If you want to get into high detail for one of the many examples in his book...you will eventually find yourself at places like this: <http://www.retrosheet.org/game.htm> :)

Also if you want some more technical detail about the overall process there are plenty of books out there: <http://news.ycombinator.com/item?id=1055042>.

</comment></comment></comment><comment><USER22> According to the article UPS predicts when you are high risk of leaving their service and will offer a sales call. I assume the salesman is allowed to offer perk/discounts to get a customer to try to stay. I'm wondering if these models can be figured out so you can intentionally trigger something like this to get deals from companies that do data mining.

</comment><comment><USER23> _The mobile social network Loopt or its competitors could conceivably predict with 90 percent accuracy where an individual will be tomorrow._

I would think that Visa would be better positioned to do this than Loopt, because people are more compelled to use their credit cards when they go somewhere. You can't go to a store and forget to pay, although you can forget to checkin.

</comment><comment><USER24> _Correction: The headline of this article originally referenced MasterCard, not Visa._

As is evident from the post URL. But why the change?

<comment><USER25> Another headline correction that is needed is that the article doesn't tell us _how_ Visa predicts divorce, just that they can.

<comment><USER26> Since they don't seem to tell what their success rate & the accuracy of the predicted date are, I wouldn't say they "can" do it, which would imply that they are 100% successful at predicting the day of a divorce.

</comment></comment></comment><comment><USER27> Political parties have been doing this for some time. Check out [http://www.voterlistsonline.com/version2/site/page.asp?page_...](http://www.voterlistsonline.com/version2/site/page.asp?page_id=home)

You can learn a lot about a potential voter (ie is he worth making a stop when canvasing?)

 _Purchase Premium Fields, including:

        - Home purchase/mortgage/refinance information
        - Presence/ages of children per household
        - Magazine subscriptions
        - Hunting/fishing licenses
        - Charity contributions
        - Additional polling options - including Targeted Random Sampling and Normalized Sampling*

</comment><comment><USER28> I wonder how expensive it is to purchase things that decrease your risk rating, while also using cash for things considered particularly risky.

<comment><USER29> You have to be more careful than that.

You need to write some script to follow random links on HN while you're away from your computer, so when you're off doing risky things you won't change your profile.

You need to occasionally forget your cell phone, so when you're doing risky things, forgetting your cell phone won't change your profile.

If you have a car, you need to pass through the intersections with red light cameras at the normal times, but no extra times, so you don't change your profile.

Does visa buy dns lookup histories? or cellphone active tower histories? or car intersection histories? probably not. yet. better to build the habits now though.

<comment><USER30> Stepwise linear regression is how they do it. All statistical packages marketed since the late 1970's include the procedures. It's what the AI craze of the early 1990's used in their black box apps.

Basically you associate a narrow set of outcomes (Filing for divorce, filing for bankruptcy, reporting a stolen credit card) and a mountain of possible predictors (store type, store name, store location, number of purchases from store in the billing cycle, ranges of purchases from a given store within the cycle). The stat program builds a regression equation out of the raw data by literally predicting trying to predict the past from data in the further past.

The cool thing is that you can't put in too many variables (as in you don't have to know if something may be related or not) since the uncorrelated variables will simply vanish in the final equation.

</comment></comment></comment><comment><USER31> Given that the article does not actually talk about how Visa predicts divorce, maybe we can speculate. Here are some ideas:

* Meals at two restaurants on same night.

* Separate vacations.

* Ages approach mid-life.

* Card used on personals websites.

<comment><USER32> I doubt there is a rationale trend. It's just statistics, really. My guess is that it has more to do with the amount of money spent by each spouse rather than what.

</comment></comment><comment><USER33> It's probably pretty easy, because in addition to _what_ is being bought, Visa knows where the purchases occur. Most people have two clusters for their purchases: work and home. A person who develops a third cluster may be having an affair. If you know what's being bought, you can figure it out with even higher probability.</comment>


Show HN: A Tinder-style app for deciding where to eat - <AUTHOR> https://github.com/kelvinfan001/findalicious <comment><AUTHOR> Covid restrictions are loosening up and restaurants are starting to reopen. Can't wait to finally eat out with your friends and family, but not used to the plethora of options out there anymore? Try out findalicious and easily decide! [https://findalicious.herokuapp.com](https://findalicious.herokuapp.com)</comment>


Netflix's U.S. Subscriber Numbers Are Slipping - <AUTHOR> https://www.theatlantic.com/entertainment/archive/2019/07/netflixs-us-subscriber-numbers-are-slipping-q2/594322/ <comment><USER2> Way too early to draw any conclusions</comment>


The annual PornHub year in review tells us what we're really looking at online - <AUTHOR> https://techcrunch.com/2018/12/13/the-annual-pornhub-year-in-review-tells-us-what-were-really-looking-at-online/ <comment><AUTHOR> It seems no one is watching porno. Can anyone tell he/she do?

<comment><USER2> I see the article says there has been quite a few visitors?

> 33.5 billion visits in 2018. There are currently 7.53 billion people on > Earth.

and seeing this is interesting

> 4,000 petabytes of data or about 500 MB per person on the planet.

did you mean everyone? there is far more details on their site blog [0] the site does not appear to have anything that cause my eye as being blatantly bad to click but I would still click while _not_ on a work computer on the link [0] they also have additional info

> Visits to Pornhub totaled 33.5 billion over the course of 2018, an increase > of 5 billion visits over 2017. That equates to a daily average of 92 million

[0] [nsfw in my opinion] [https://www.pornhub.com/insights/2018-year-in- review](https://www.pornhub.com/insights/2018-year-in-review)

edit: added more info, formatting</comment></comment>