Toothless No More – Researchers Using Stem Cells To Grow New Teeth - <AUTHOR> http://singularityhub.com/2012/05/10/toothless-no-more-researchers-using-stem-cells-to-grow-new-teeth/ <comment><USER2> Dentist here. You're probably wondering if this is a disruptive threat to the established business of dentistry -- I have no idea. However, I can say that throughout the field I consistently run into dentists who will advocate for the health of the patient over the profit of the business. Consider the fluoridation of water throughout the world, one of the single greatest public health advances, when you take into account the benefits versus the cost of fluoridation.

But the science of it: I'm excited by the tooth growing possibilities, but it's important to understand that getting these teeth properly integrated into the body is quite a challenge. I'll give you an example: the periodontal ligament is like a very precise shock absorber attaching bone to tooth, and gives some flex to the tooth. (It's also the thing that makes orthodontics (moving teeth) work in the first place.) Sometimes, (usually in younger folks) if you knock a whole front tooth out, you can immediately replace it and the PDL will regenerate. Sometimes, however, the PDL fails to regenerate, and you end up with a situation where the tooth is ankylosed -- the ligamentous connection is gone, and the tooth is essentially fused to bone. This is one of the difficulties that will need to be overcome when regenerating teeth -- if that PDL fails to develop, you're stuck with a newly regrown tooth fused to bone. Thus, the tooth is more susceptible to breaking and _really_ difficult to extract from the mouth if it becomes infected.

<comment><USER3> Off topic, but I just remembered that when I was a kid there was some snippet on the news about a new treatment which would allow the gums to be softened (??) which would give the doctor/ortho time to reform the teeth. This was supposed to be the quick and fast answer to braces. I never heard of it again and when I've searched for it I've come up empty. Have you heard of this?

<comment><USER2> You may be thinking of Wilckodontics. From what I could tell, they don't really go into depth on their website, but what they do is place braces and then irritate the bone (essentially drill holes ("scar" the bone) in strategic spots). During the healing from this insult, osteoclastic activity is increased... accelerating the remodeling of bone. As the bone remodels, it can respond more quickly to PDL forces than it normally would. I think I first heard about this in the context of military folks who needed orthodontics, but needed results quickly.

</comment></comment></comment><comment><USER4> Hah. This reminds me of a conversation I had with my dentist.

I was there for yet another appointment to work on a root canal and wondered out loud why I don't hear more about efforts to regrow actual teeth as opposed to the gruesome practice of modern dentistry. His take on this was that it just wasn't worth it: teeth are mostly mechanical. They just exist to bite through food, and an artificial crown isn't going to develop any more cavities. His take was that it's much simpler for humanity to just replace teeth with metal and porcelain than spend research dollars and scientists trying to grow teeth.

Then again, he makes his living drilling into jaws.

<comment><USER5> I would agree with this, although I'm in the unenviable position of needing a lot of dental work after not having had any for awhile. I'd far rather have research be done into making longer-lasting and/or cheaper or easier to implant permanent fake teeth that don't require thousands of dollars of upkeep throughout your lifetime.

That said, on a conceptual level, the idea that you can regrow teeth with stem cells is pretty damn cool.

<comment><USER6> It cuts both ways. I did have a lot of dental work done when I was younger, after a couple of unlucky events damaged many of my teeth. Today, I expect to spend hundreds of pounds on dental work every year or two, mostly repairing and replacing that earlier work, even though I have excellent oral hygiene and eat/drink sensibly.

I would spend a great deal of money, or even accept significant pain and making do without proper teeth for a few weeks, if it meant that I could have a new set of natural teeth at the end that I could brush and floss normally and that didn't keep hurting somewhere every few months anyway. Sadly, it turns out that all the fillings and braces and crowns and bridges in the world can't keep up with what nature gave me.

</comment></comment></comment><comment><USER7> The real disrupting tech would be the thing that can kill that 1 strain of bacteria responsible for eating the sugar on your teeth and pooping acid all over them in return.

Its this acid discharge that dissolves tooth enamel. So, neutralizing that acid (like we try to do with baking soda) on a more _permanent_ basis would be super effective. As would simply targeting the 1 funky bacteria that turns sugar into acid (as opposed to nuking all the 1000s of beneficial bacteria too). It would seriously eat into dentists' coffers.

Can't we engineer viruses on a high level to do stuff like this for us yet? Virus vs Bacteria-- a match for the ages.

<comment><USER8> We already did. S. mutans has been genetically modified to excrete water instead of the acid that normally wears away enamel.

[http://abcnews.go.com/Health/Dental/story?id=98080&page=...](http://abcnews.go.com/Health/Dental/story?id=98080&page=1#.T6whluhYvgA)

<comment><USER9> _Recently they tweaked the bacterium again so it would only survive if fed a particular nutritional supplement. That ensures the bacterium won't spread from one person to another while kissing or sharing utensils._

AKA vendor lock-in.

<comment><USER10> It's still rather experimental. At this stage, I'd rather have the bacterium require supplements than risk more widespread problems. Once proven safe, then hell yeah, open the floodgates.

</comment></comment></comment></comment><comment><USER11> On a somewhat related note, my dad (a dentist and scientist) recently discovered that there are stem cells that are almost as easy to manipulate as embryonic ones .. in our mouthes [1][2]. He always wondered why our gums heal so quickly, even as we age.

[1] Sorry for the PR-ish link (I'll ask him for the actual paper) - [http://singularityhub.com/2012/05/10/toothless-no-more- resea...](http://singularityhub.com/2012/05/10/toothless-no-more-researchers- using-stem-cells-to-grow-new-teeth/)

[Edit 2] Here's the original publication (free) from Stem Cells Journal <http://onlinelibrary.wiley.com/doi/10.1002/stem.425/abstract>

</comment><comment><USER12> They only got a grant for $1.5M to work on this? These dentists are in the wrong business! They should make an iPhone app to share pictures with your friends then they will really cash in!

<comment><USER13> Maybe they could create an app that was a virtual mouth. You'd have to brush and floss regularly. Every clean checkup would get you 100 points . When you get a cavity, you lose 200 points. Make it for kids.

If you make this app, I want 5% ;)

</comment></comment><comment><USER14> Does anyone know why these kind of things always seem to need a scaffold? When our original teeth grew there was no scaffold needed. Why can't we trigger that kind of growth?

<comment><USER15> Your growing jaw provided the scaffold.

</comment></comment><comment><USER16> A quote from the article: "So far, teeth have been regenerated in mice and monkeys, and clinical trials with humans are underway, but whether the technology can generate teeth that are nourished by the blood and have full sensations remains to be seen."

I understand the vital importance of pain as a signal that damage has occurred or is occurring. One of the real design flaws in the body, however, is the inability for humans to consciously shut off pain (at least temporarily) after they are aware of it.

The pain from a severe toothache is one of the worst sensations possible, and doesn't seem to accomplish much. If dental regeneration can become commonplace and relatively cheap, I think I would prefer new teeth without nerve endings and "full sensations."

</comment><comment><USER17> Oh man, I would love this. For some reason, every so often, a tooth of mine starts hollowing out from the inside and I need a root canal. Then a few years after that, the hollowing out resumes and the tooth eventually distintgrates, and then I need an implant. This has happened four times already, and it looks like #5 is beginning.

</comment><comment><USER18> This is still pretty experimental, although it's worked for mice and monkeys, and apparently they're working on human testing.

</comment><comment><USER19> Is there any reason the fashion industry couldn't use this to produce, say, a coat with teeth for buttons? I would totally wear that, especially to my D&D game.

</comment><comment><USER20> And maybe, if the Nerve Ending Fairy leaves them enough $100 bills, Americans can afford one of these new teeth!

</comment><comment><USER21> Toothless stem cell researchers. Getting crafty.

</comment><comment><USER22> I have nothing "scientific" or explanatory or "insightful" to offer. I've always found dentistry to be barbaric. And I've lived in terror of dentists. As a youngster, I, without guidance, stumbled onto using electric toothbrushes through my own devising. I did not brush properly, on the assumption that the technology I was using, and using it in a way I thought best of it, was the way to properly brush teeth, as opposed to the dentist's recommended methods.

My mistake, whups. But within a year's time (age 10-11), I developed 13 cavities. I was devastated. For years I have lived with a slip-up in my formative years, and am still living with that mistake, stupidity, etc.

But THIS excites me extremely. Daily I live with empty, squishy graves where two upper canines on each side used to LIVE. The "grave" analogy is not mine. I sought sympathy from a friend one day, as I confessed to him my difficult decision to have the teeth removed.

But I agreed with his words. And I felt a kind of bereavement. Daily I feel it, and it affects my work. I feel declawed. Detuned. Constantly I question my competence based on my linguistic performance, as the procedure has re- introduced my lisp. (I wouldn't dare give presentations on HTML5 and advancing technologies to corporateheads in this state now.) I'm sure millions of others would be liberated if they could regain those portions of their minds that their teeth or lack thereof distract them from.

I will follow this science, and try to understand it.

</comment><comment><USER23> This is pretty cool because I recently learned that you can also HARVEST stem cells from wisdom teeth and get it put away. From teeth they came and to teeth they may go.

</comment><comment><USER24> "To date, the NSU researchers have received about $1.7 million in grants for their dental stem cell research."

They should have done a kickstarter.

How much did facebook pay for instagram again?

</comment><comment><USER25> __Quack Alert __

I'm just relaying what I've heard, so take it with a grain of salt, but on an episode of No Agenda, Adam Curry says that he had dinner with a guy who worked in stem cell research in Germany (I'm fairly certain it was Germany) the guy said with confidence that the technology exists to regrow fingers. The guy expressed frustration that such technology will never be released.

I know that most people will be highly skeptical, but it doesn't sound all that unreasonable to me.

<comment><USER26> Stem cell biology and synthetic organogenesis (not sure what the term for this will eventually be) are not my fields. However, we are getting excited about regrowing myocardium from stem cells when sitting on top of a pre-existing scaffolding. That's one _tissue-type_.

A finger requires afferent and efferent nerves, bone, cartilage, synovium, tendons, ligaments, vasculature, interstitium, muscle, dermis, and epidermis. It seems highly unlikely that we can regrow a _finger_ given current technology. Each individual piece? Maybe. Each of those pieces in their proper place coalescing into a functional whole? I don't buy it.

<comment><USER27> You argue against building the tissue. I buy your argument.

Small children can regrow fingertips, yes? Couldn't it be possible to use that mechanism for fingers?

<comment><USER26> My understanding is that there is research in what you suggested. I'm just saying that I don't believe we yet have the technology to grow a finger. Someday, almost surely we will. Just, not for some time. Or so I think.

<comment><USER28> They can already regrow a fingertip in an adult, though I think that is (as you said) still in research stages and not available to the general public. Having regrown lung tissue of my own using info available online and no fancy gizmos to speak of, presumably we aren't terribly far off from bigger accomplishments.</comment></comment></comment></comment></comment>


Ask HN: Do you tell other people about HN? - <AUTHOR>

I've been very hesitant to tell any of my friends about HN. I've seen the kind of content that gets generated when the community population explodes, and I'd really hate to see that happen here. It's not that I don't trust my friend's content, I don't trust their friend's content.
I know the HN has generally rebuffed off-topic material, but at the same time it still shows up. Should the broken window theory or a video of a meteor really be on the front page today? Its not that I don't enjoy that content, but allowing some of it is a slippery slope and before you know it we could be seeing posts that stipulate that Karl Rove eats deep fried baby flesh.
So HN, what do you think? <comment><USER2> Yes, I tell smart people. If their friends' friends submit stuff that's offtopic, the editors just kill it. Though in fact I think our strongest defense against idiots is to look boring to them.

Incidentally, the broken windows story isn't offtopic. News.YC isn't just about hacking, because good hackers aren't only interested in hacking.

<comment><USER3> likewise, i tell people i think will contribute and/ or involve themselves with the community, not just use selfishly... after-all i think what we're all doing here is valuable. otherwise, just keep you're mouth shut. my dad always said, "loose lips sink ships". it's trite, but still true.

</comment></comment><comment><USER4> The first stage of a community falling apart is when it starts getting meta. When your prayer group start discussing about how right their prayer group is, and how wrong other groups are; when K5 started getting lots of articles about K5; when the IQ club starts talking about how IQ makes them different.

That's always the step that precedes some type of change. Because when people start looking within, they never seem to be satisfied with what's there.

<comment><USER5> That's what it was like with Reddit. Their new subreddits saved themselves from that: AskReddit is an excellent part of the site, now.

Metafiler has AskMeFi. Maybe Hacker News could get something like that? Or perhaps we could choose to filter out self-referential posts?

<comment><USER6> I think an option to filter out (or just see) self-referential posts would be great. I actually like AskHN posts a lot, and an option to just see those posts would probably encourage people to post more.

</comment></comment></comment><comment><USER7> As far as telling other people goes, I find that HN comes up most often when I tell my friends about the interesting stories I find here. The reaction from non-technical people is usually something to the effect of: "Where the hell do you find this stuff??" The reaction from technical people is usually something like: "Yeah, I already read that on HN." With regards to the first group, it seems that they always find the stories interesting, but never show any signs that they'll make HN one of their news sources, and I'm fine with that.

For me, things such as the meteor video or an article about the Broken Windows Theory are fine, and I don't foresee any "Karl Rove eats deep fried baby flesh" articles soon, but I'd like to keep it that way. The community at HN is the root of the reason I keep coming back.

</comment><comment><USER8> Conversation with a friend:

friend: "You don't look good, whats wrong"-

I: "I haven't slept that well, i was up all night"

friend: "WTF were you doing all night"

I: "Lurking on HN of course, and reading the old Dilbert strips"

Maybe i should try this "noprocrast" feature, but i don't know what to do about Dilbert though. :D

You people are great, i read reddit to find cool articles, but i don't bother to read the comments, but here, i read mostly the comments, they are more valuable than the original articles sometimes.

<comment><USER9> Indeed, I often find myself reading the comments before the article here.

It's probably a bad habit though, I suppose I should form my own opinion about the article first.

<comment><USER10> I did this all the times, so I don't waste my time to read awful articles.

</comment></comment></comment><comment><USER11> My _least_ favorite HN content, by far: Bitching about HN and its content.

Srsly, folks, just _don't vote it up if you don't like it_. It really is that easy.

This isn't "startup news" or "programmer news", it's "hacker news". It's news that is interesting to hackers. And it delivers quite well.

As it happens, some hackers are into politics or business or meteors or robots or science or economics. Some are not.

You should expect that about 10-20% of the articles will not be interesting to you. Consider that a success.

</comment><comment><USER12> I tell people about it but most people aren't interested. I think they're happy to let me be their geek news filter, or perhaps they're just humoring me. Either way I think the aesthetics of the site go a long way to keep out wrong people.

</comment><comment><USER13> First rule of hn. Don't tell others about hn.

</comment><comment><USER14> None of my friends would like it. As unscientific as the Meyers-Briggs test is, I really do think this site appeals mostly to a small subset of XNTPs. And there aren't that many of those around.

<comment><USER2> I just tried one of those tests. It said I was an INTJ. Are the letters in order of significance? I.e. is INTJ the next door neighbor of INTP?

<comment><USER15> It's a weird theory, but it is somewhat coherent. INTJ is very close to INTP, just not really for that reason. ENTP is the classic entrepreneur. INTP/INTJ is the classic hacker; there was a poll on here and nearly 60% of the people 662 people who voted were INTP/INTJ, whereas they're each around 2-3% in the ordinary population. 10% of the rest were ENTP. (<http://news.ycombinator.com/item?id=204240>)

Basically, the Myers-Briggs type determines your preferences for particular cognitive functions. The four letter indicator is like an extreme Huffman coding of those preferences:

Your information-gathering, perceiving function (that is, input.) This can be either i(N)tuitive or (S)ensing. Roughly, a sensing person trusts their senses, directly what they see and hear from the world. And an intuitive person trusts, or looks for knowledge, in their subconscious and conscious cognitive models.

Your decision-making, judging function (that is, output.) This can be either (T)hinking or (F)eeling. Roughly, the thinking person is at ease when they can make a decision supported by a logical process, and the feeling person prefers to make the decision according to their gut.

(E)xtroverted and (I)ntroverted describes the social attitudes of each of the 'functions,' in other words, whether you, when information-gathering, or decision making, prefer to focus on behavior, action, people and things or the internal world of ideas and reflection. There is only one letter for this, even though each function is supposed to have its own attitude. This is because Isabel Myers believed that there was always a balance; if you are introverted in information-gathering, you're extroverted in decision making.

Finally, the last letter, (P)erciving or (J)udging, specifies which side of yourself; perception (information-gathering) or judgment (decision-making), you tend to show to the world. Perceiving types prefer to "keep decisions open." Judging types prefer to "have matters settled." The YCombinator practice of deciding quickly, while it may be a definite plus for both sides, is a judging characteristic, for example.

<comment><USER16> "Basically, the Myers-Briggs type determines your preferences for particular cognitive functions."

This is backwards; your Myers-Briggs type is determined by your preferences, and is ultimately little more than a form of horoscope targeted at those who realize that birth month has no significant correlation with personality.

<comment><USER15> I meant determine as in "to find out or come to a decision about by investigation, reasoning, or calculation." I didn't say that it was necessarily 100% accurate.

But the MBTI is not a horoscope. The INTP/INTJ slant here is _way_ statistically significant. Obviously there's something there.

<comment><USER16> The same thing that is there if you ask a bunch of computer science students whether or not they like computers. Sure, the result is statistically significant; it just doesn't tell you anything you didn't already know. The categories of the MBTI are sufficiently broad and vague that having an atypical distribution of results on HN doesn't actually tell us anything about ourselves that wasn't inherently obvious.

<comment><USER15> It's not as if we're just asking people if they like computers, and parroting it back. The MBTI was published in 1962. Barely anyone had _access_ to computers then.

I don't know how you'd measure this, but the profiles, to me, certainly aren't broad and vague. They make very specific and very falsifiable claims about personality, and all out of a mere 4 bits of information. The first time I read my profile (ENFP) it was like a bolt of lightning shot through me. It had me to a 'T.' My _parents_ couldn't describe me so well. And my experience is far from atypical.

There are a bunch of other major statistical discoveries about the different groups. For example, INTP's have the lowest level of emotional coping resources, while their cousins, the ENTP's, have the highest! INTJ's have the highest college GPA's, while the adjacent INTP's have much lower, scoring far below what their aptitude tests would indicate. There is a lot of real information in those few bits!

Sources: J. Shelton, in MBTI Applications by A.L. Hammer, 1996. More at: <http://www.ransdellassociates.com/INTJ.htm>

<comment><USER16> The claims made aren't all that falsifiable (like anything else in psychology, it isn't ever possible to know to what extent a person is lying to themselves), and the specificity of the claims is something of a red herring; when 90% of a list of specific claims appear to describe a subject to at least some extent, if they want to believe that the system works, they're going to ignore the other 10%. The medium-sized fraction of the audience who fit at least that closely into the categorization system trumpet it around as a success, making those who fit somewhat less well more inclined to accept the errors and inaccuracies of their classification. These effects, plus the handful of results related in a very obvious way to the original categorization (emotional coping resources are often defined in such a way that the INTP/ENTP result you mention is entirely obvious, for example), make it appear that the MBTI means much more than it actually does.

Much like an IQ test, used professionally, as part of a deeper analysis of a subject, the MBTI can help a psychologist or psychiatrist better understand a subject/patient. Used recreationally, such things lead to faulty generalizations unless treated as they are--glorified horoscopes geared toward looking at particular aspects of ourselves.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER17> Have a look at the comments on the broken window theory post, a lot of them are about the applicability of the theory to online social sites, something which is very on-topic on HN. Just because an article isn't inherently startupish, it doesn't mean that it's not relevent to HN.

</comment><comment><USER18> My approach is to tell only startup founders about HN. You will be surprised that many founders do not know about HN at all. But, it becomes less and less now.

And, my approach to meet smart people is to check out how many karma points those people have in HN.

</comment><comment><USER19> I'm also cautious about writing about HN on various communities I visit simply because I fear it would attract the wrong crowds, e.g. spammers, trolls and your average eternal septemberists.

Right now HN is a great community for startups, Internet businesses, developers, designers, and entrepreneurs. The signal to noise ratio is very high and discussions are relevant, mostly civil and very interesting. Heck, I can't name another site with so much _relevant_ content for Internet businesses.

Furthermore, I think it's perfectly fine that HN remains a relatively small and focus community, not every site must be like Digg or Slashdot in size.

Regards, WarTheatre

</comment><comment><USER20> I'm more disappointed to see "10 Totally Stupid Online Business Ideas That Made Someone Rich" on the front page than broken windows or a meteor. Being on-topic doesn't make up for bad content.

</comment><comment><USER21> The broken window theory article wasn't off-topic, the discussion immediately evolved into how it related to online forums and was very interesting.

</comment><comment><USER22> I am bored of all these posts that talk about HN. I am not on HN to talk about HN itself dammit.

</comment><comment><USER23> I heard about it from my friend at work.

</comment><comment><USER24> Yes, I tell others about HN, but only those that I know will be valuable and interested users.</comment>


Tripeedo: Command line for travel (from Wundrbar) - <AUTHOR> http://ajaxian.com/archives/tripeedo-command-line-for-travel

<comment><USER2> I thought this would be more like SABRE/Easy SABRE, which I loved.

This just isn't a useful tool for me in its present form -- I've never had any trouble typing in my search parameters on the various travel websites and this seems to be all that this does.

commandline + flights available + airfares would be super valuable to me though.

<comment><USER3> For real! Imagine being able to pipe to grep etc. Actually if they have any sort of api that takes the command string and returns json surely that wouldn't be that hard to hack together.

[after using the site for a bit] Nevermind I guess it just primes your search for you (still cool) and then sends you to the site itself. I was thinking it would actually return a data set of prices per carrier.

</comment></comment><comment><USER4> As far as I call tell Wundrbar is a complete rip-off of YubNub:

<http://yubnub.org/>

</comment><comment><USER5> Nice-- would love to see it work for car rental, too...

</comment><comment><USER6> bookmarked!</comment>


Swift Sudoku Solver - <AUTHOR> https://academy.realm.io/posts/try-swift-nyc-2017-souroush-khanlou-spontaneous-swift-sudoku-solving/ <comment><USER2> As the author mentioned, it cannot solve any boards where all unfilled cells have more than one possible value within the cell's domain. More information about the algorithm here:

[https://en.wikipedia.org/wiki/AC-3_algorithm](https://en.wikipedia.org/wiki/AC-3_algorithm)

You would need to implement something like forward checking or backtracking algorithm to solve all possible boards with higher cost.

<comment><USER3> Here is one in Swift I did a few years ago that does:

[https://github.com/isaksky/sudoku- swift/blob/master/Sudoku-S...](https://github.com/isaksky/sudoku- swift/blob/master/Sudoku-Swift/main.swift)

This one solves all 50 from Euler: [https://projecteuler.net/problem=96](https://projecteuler.net/problem=96)

And here is a classic one in Python from Norvig:

[http://norvig.com/sudoku.html](http://norvig.com/sudoku.html)

<comment><USER4> Shameless plug, my OCaml implementation: [https://github.com/eprochasson/norvig- ocaml](https://github.com/eprochasson/norvig-ocaml)</comment></comment></comment>


Why every programmer should know about security - <AUTHOR> https://www.linkedin.com/today/post/article/20140623153433-7082046-why-every-programmer-should-know-about-security

<comment><USER2> The most important thing that every software developer needs to know about security is just remember that "bad" guys are out there. I've seen many cases when people make bad security decision simply assuming that it is just fine and nobody cares. Having a little paranoia as a software developer will help you to write better code (not only from security perspective).</comment>


WordPress Hosting Performance Benchmarks - <AUTHOR> http://reviewsignal.com/blog/2014/11/03/wordpress-hosting-performance-benchmarks-november-2014/

<comment><USER2> Re:AWS, this test benchmarked Cloudways managed WordPress on top of AWS. They don't specify instance type, underlying software config, etc. This has little to do with AWS.

<comment><AUTHOR> CloudWays told me they deployed the same stack on AWS/Digital Ocean. I do specify what instance type (m1.small 1.7GB instance) vs 2GB DO droplet.

</comment></comment><comment><USER3> We do a lot of AWS work, so it is interesting to see the poor AWS performance. Any theories as to why it might be?

<comment><AUTHOR> I think AWS is best suited for companies really using many of the services in conjunction with one another. If you're just after raw CPU/RAM/IO, I think EC2 is overpriced as an option. Guys like Digital Ocean are offering a lot more bang for your buck (as the testing shows) on that front. Digital Ocean also lacks a ton of the features of AWS, so that's the trade off.</comment></comment>


The Six Stages of Debugging (2012) - <AUTHOR> http://plasmasturm.org/log/6debug/ <comment><USER2> _Somebody taped this on their door at work:_

The door to which they were taped was in IL2 and belonged to Mike Engber. He says, "The version on my door now is nicely laminated."

The list itself was created be me some years prior when we worked on Newton, after a particularly frustrating DMA debug session.

<comment><USER3> Hey, cool! Nice to get an attribution – is it OK if I add the citation to the post? Anything else you remember about it?

</comment></comment><comment><USER4> 1\. This doesn't work, and I don't know why

2\. I have no idea how this is supposed to work

3\. Let's change some random thing that shouldn't be related at all

4\. This works now, and I have no idea why

5\. Pray to the gods of code that whatever it was that broke doesn't happen again

<comment><USER5> From a recent meme:

99 little bugs in the code, 99 little bugs. Take one down, patch it in Prod, 117 little bugs in the code. -Attributed to Kurt Cobain

<comment><USER6> I just sang this to my sister. She laughed, but doesn't understand. God, we're nerdy.

</comment></comment></comment><comment><USER7> I had forgotten about this site and am pleased to get a reminder. Its the place I first saw the immortal quote:

A friend of mine in a compiler writing class produced a compiler with one error message "you lied to me when you told me this was a program". —Pete Fenelon

[http://plasmasturm.org/code/](http://plasmasturm.org/code/)

</comment><comment><USER8> Do yourself a huge favor and skip steps 1-3. Have a deep, abiding, instinctual faith in your own incompetence.

<comment><USER9> Until you hit a compiler bug. I'll never forget a certain PIC C compiler that would only ever take the first case in a switch statement, and how long it took me to believe that my code was actually fine but that the compiler wasn't.

<comment><USER10> I used to work with a guy who would blame every bug that cursory inspection couldn't uncover on the compiler. This is of course laughable, but he'd once, ages before, actually _found_ a compiler bug. I wonder if having this amazing get-out-of-debugging card made him a jobsworth, or was simply a magical proof of "God takes care of fools and drunks."

<comment><USER11> Embarrassing story time: I was this guy at one point. I had the vast misfortune of finding a compiler bug early in my career. It was in a somewhat obscure variant of gcc cross-compiling for a slightly obscure architecture (PowerPC). I still remember learning PowerPC, reading through the code, and determining that it was indeed the dcc compiler at fault. It was, frankly, an awesome feeling. Especially because this bug took two weeks to track down.

My coworkers naturally doubted that I had found a compiler bug. Correspondence with the compiler's developer confirmed my initial finding. I was vindicated, and could prove I had caught one of the most reclusive bugs of them all.

Fast forward two years, and my coworker is having trouble with MSVC 6 (an old compiler, even at the time). The behaviour seems odd, and my mind jumps back to that one bug I found previously. We isolate it down to one line, and I state with confidence that the compiler generated incorrect code.

My coworker agreed at the time. But the next day, after re-reading the code, he pointed out that I had read it incorrectly. The compiler was doing exactly the right thing. To further my embarrassment, it wasn't even some obscure feature of C (like trigraphs). I made a common mistake and misunderstood basic pointer arithmetic. I still feel an urge to slam my head into my desk right now.

Morale of the story: compiler errors are rare. Really rare. I essentially caught bigfoot on my first hunting trip. Now I have to reassure myself I'm not seeing him again every time I'm confronted with a difficult debugging problem.

Or in technical terms, only declare you have found a compiler error if you have:

(1) read the generated assembly

(2) re-read the code several times alongside the relevant language specification

(3) developed a reproducible example

(4) formulated a plausible theory of what went wrong in the compiler, and contacted the vendor who has confirmed your suspicion

<comment><USER10> This is a marvelous story, thanks.

</comment></comment></comment></comment></comment><comment><USER12> The Margaritaville stages of debugging:

1\. It's nobody's fault

2\. It could be my fault

3\. It's my own damn fault

<comment><USER13> I was merely going to append to OP's list:

7\. Who wrote this crap?

8\. Oh, I wrote this crap...

</comment></comment><comment><USER14> The first time I saw this was on bash.org:

[http://bash.org/?950581](http://bash.org/?950581)

<comment><USER15> The "one day we will write tests" hits more than a little close to home.</comment></comment>


Orbcomm OG2 Falcon 9 Satellite Launch - <AUTHOR> http://www.spacex.com/webcast/?orbcommogbjuly14 <comment><AUTHOR> Wow I can't believe this finally launched. So far so good! And of course, the most exciting thing about this is the return attempt of the F9 first stage core. I don't think that'll be covered in the webcast but we'll certainly get video of it later. MECO successful.

Edit: r/spacex has good updates regarding the landing attempt

[T+27m]: Elon's jet and NASA plane circling a particular area...

[http://www.reddit.com/r/spacex/comments/2aany2/rspacex_orbco...](http://www.reddit.com/r/spacex/comments/2aany2/rspacex_orbcomm_og2_official_launch_discussion/)

<comment><USER2> Awesome, I noticed they were tracking the landing leg attachment points at liftoff, so perhaps there is a new leg deployment system.

Also the note that 'kaboom' _after_ splashdown suggests that some part of the landing mechanism didn't deal well the transition from flight to sailing. One wonders what the temperature differential is between the landing first stage and the ocean, on the one hand it might be hot (burning retro) on the other it could be sub zero (cryogenic propellant usage).

Questions then are:

1) What was the mechanism that instituted the rapid disassembly of the landing stage.

2) Would that mechanism come into play on a 'ground' based recovery?

3) What is the safe radius for ground recovery in the event of a structural failure?

<comment><USER3> Like trothamel commented below, the stage isn't designed for tipping over and slamming into the water.

<comment><USER2> My problem with that theory/scenario is that the stage is designed to land on its legs. When the test vehicles land they have very little angular momentum, presumably these tests would mimic that. And if the momementum was managed, then at engine shut off it would drop vertically into the water, and then fall over as the counter pressure of buouancy was not stabilized by the landing legs.

If you've ever seen loggers drop tree trunks in a river you can imagine what that looks like, it starts out vertical, then reaches point where it displaces enough water that it is essentially floating (but unstably so) and then rotates to horizontal around the point on the trunk that is at the surface of the water.

I totally understand that this isn't an intended landing mode :-).

Thinking about how they manage fuel load, it made me wonder how I would do it, do you hover until you've exhausted all fuel? Or do you just shut off the engine? And at flameout are you out of volatiles or just some volatiles (like LOX)and do you have the 'gas tank' issue that auto mechanics deal with where residual vapors can be explosive.

Would love to sit through the briefings on this stuff.

<comment><USER3> The problem with your picture is that the empty stage is extremely light for its volume so, unlike a log, it floats very high in the water. Floating upright, most of it is above water and the top of the rocket is _high_ above the water. The full launch vehicle is 220ft tall, and 2/3 of that is the first stage.

</comment></comment></comment></comment></comment><comment> grey-area Looks like the landing was only partially successful -

Rocket booster reentry, landing burn & leg deploy were good, but lost hull integrity right after splashdown (aka kaboom)

[https://twitter.com/elonmusk](https://twitter.com/elonmusk)

<comment><USER4> I think it's hard to say that, yet.

The rocket isn't really made to survive tipping over onto its side in the water. If they "landed" properly (legs deployed, descending at a slow speed when they hit the water), I think one can make an argument for a fully successful landing.

It really depends on how fast they hit the water.

<comment> grey-area Sure, it depends, we'll have to wait and see what SpaceX decide to release about it. It'll be nice to see video if they have some.

</comment></comment></comment><comment><USER5> This launch seemed to use a much steeper trajectory. Typically they go downrange much faster than they gain altitude, but today they seemed to go up faster than they were going downrange.

How does this affect the fuel efficiency of the launch? Is this a way to cut down the horizontal velocity so they first stage can return more easily?

<comment><USER6> It's a product of a higher target altitude (650km for Orbcomm vs. 330km for an ISS resupply) and wanting to perform a single second-stage burn to achieve the target orbit.

</comment></comment><comment><USER7> The second stage Falcon engine appears to have suffered some insulation degradation and loss. It develops just above the bell, on the right-hand side of the motor image in the video. After second stage shutdown, a vapor emission is visible just above the site of the degradation (at the very end of the video).

Was this a normal venting, or a non-catastrophic failure of the second stage engine? Congratulations, SpaceX, on designing such a robust engine!

Video of launch: [http://new.livestream.com/spacex/events/2980259/videos/56576...](http://new.livestream.com/spacex/events/2980259/videos/56576194)

<comment><USER3> I believe those are normal vents. If you look at previous videos like [http://youtu.be/RtDbDMRG3q8](http://youtu.be/RtDbDMRG3q8), there's are whole frost "christmas trees" at several places around the base of the nozzle.

</comment></comment><comment><USER8> Humph.

I'm choosing to take this personally!

(I was in Orlando at YAPC::NA in June, and drove up to the Cape _twice_ in hope of seeing it launch. Scrubbed both times, and I got bitten to hell by mosquitos before I discovered DEET -- yes, I'm British, we don't have flybown tropical swamps.)

Ah well, maybe next time I visit ...

(Note that on the second visit they'd closed off the beach that enthusiasts usually used to watch launches from. Much muttering among the rocket fans present about SpaceX behaving very oddly -- this was the attempt when they also cancelled the webcast. I wonder what was going on?)

</comment><comment><USER9> Is this the re-usable launch vehicle, i.e. the one that re-enters the atmosphere and lands itself upright?

<comment><AUTHOR> Essentially yes. They won't be able to reuse this particular vehicle, but it will return and hover over the ocean for them to retrieve. They'll recover it and study the results to make the next one even better. Real reusability is probably at least a year away.

</comment></comment><comment> K-Wall I'll admit I do not regularly follow space launches but I am amazed at the various places that they have installed video feeds. Seeing the first stage drop off was incredible.

<comment><USER10> What's a first stage drop off?

<comment><USER11> AKA stage separation.

The first stage must provide a lot of thrust to get into lower gravity, so it's quite heavy with fuel and has 9 engines. After the fuel in that stage is expended, the rocket splits in two, dropping that first stage back to earth. The top half of the rocket contains additional fuel and whatever payload the rocket is delivering (including potentially an additional stage + engine) and is powered with a single engine.

Here's an older video showing the separation:

[https://www.youtube.com/watch?v=p4lOJjKGoIY#t=193](https://www.youtube.com/watch?v=p4lOJjKGoIY#t=193) (Goto: 3:15 if the link doesn't work)

The first stage that drops off is the one that SpaceX is attempting to recapture. Historically, that stage just lands in the ocean and is either scuttled or must be extensively cleaned and retrofit in order to fly again. SpaceX figures if you leave a bit of extra fuel in the tanks, you can land it vertically at the same site it took off from, and save yourself the time and expense associated with cleaning and retrieving it.

This would be very valuable since the rocket engines are typically the most expensive components of a launch, and the first stage has 9 such engines:

[http://i.imgur.com/QzrPePS.png](http://i.imgur.com/QzrPePS.png)

<comment><USER12> It isn't higher gravity they're overcoming with the first stage, but rather the much higher atmospheric pressure near the surface. Gravity in orbit is almost identical to gravity at the surface.

<comment><USER11> Pedantic and completely correct. H/T.

</comment></comment></comment></comment></comment><comment><USER13> Watching the camera feed of the launch around the 5 minute mark all I could think was: if the rocket turned around now, it could probably land in New York in another 5 minutes

<comment><USER14> On a ballistic trajectory, you can reach anywhere on Earth in 40 minutes or less. I've seen cute little diagrams of the relevant times before, but I wasn't able to quickly Google one up.

<comment><USER15> Everyone who grew up during the Cold War knows this instinctively!

</comment></comment></comment><comment><USER16> In case you want to watch it on youtube, [https://www.youtube.com/watch?v=lbHnSu- DLR4](https://www.youtube.com/watch?v=lbHnSu-DLR4)

</comment><comment><USER17> Launch webcast: [https://www.youtube.com/watch?v=lbHnSu- DLR4](https://www.youtube.com/watch?v=lbHnSu-DLR4)

</comment><comment><USER18> I have nothing at stake in these launches but every one of them makes me nervous, I almost can't watch them. At any moment, boom.

The launch video was beautiful though, the water vaporizing and forming a could around the rocket is awesome, the inside view of the engine was amazing.

Can't wait to see the landing video!

What about the location of the landings? Have they been on target?

<comment><USER19> They seem to be having consistent results (modulo the landings), so it's almost safe to take a successful launch for granted (at least for people like us who are just watching).

</comment></comment><comment><USER20> This is the fourth separate attempt at launching this mission. The first one was more than a month ago. Their biggest problem are helium leaks.

Successful launch. We can expect better video footage of the first stage landing.

<comment><USER21> So what happened on the first 3? Crashes?

<comment><USER22> No, aborted before launch.

<comment><USER21> That makes sense. I feel like a crash would have been bigger news. Lucky I caught the stream when it actually went up!

</comment></comment></comment></comment><comment><USER23> "Speed 7.2km/s...and we have miko" \- what's miko referring to in this case?

<comment><USER24> Other commenter described it as MECO, googled that, found "Main Engine(s) Cut- Off".

</comment></comment><comment><USER25> Awesome! Are they going to repeat the launch for the west coast?

<comment><USER26> Their launch manifest ([http://www.spacex.com/missions](http://www.spacex.com/missions)) lists one more launch from Vandenberg in 2014, and a few more in 2015. Eventually, if everything goes according to their plans, they will be doing regular launches from the west coast. _(Which site they use is determined by which sort of orbit they are shooting for. They will launch from Vandenberg whenever appropriate. Vandenberg is typically used for high-inclination /polar orbits, or the rare retrograde orbit)_

</comment></comment><comment><USER27> Orbcomm, you say? This is all I can think of: [http://upload.wikimedia.org/wikipedia/en/a/a9/U.F.Off_- _The_...](http://upload.wikimedia.org/wikipedia/en/a/a9/U.F.Off_- _The_Best_of_The_Orb_%28The_Orb_album_-_cover_art%29.jpg)</comment>


Free Computer Science Courses - <AUTHOR> http://freescienceonline.blogspot.com/2009/09/free-computer-science-courses.html

<comment><USER2> Great list. I didn't see any of the courses in Stanford's Enginnering Everywhere package mentioned, <http://see.stanford.edu/see/courses.aspx>. I found Programming Paradigms to be a fantastic overview especially the parallel programming and functional programming overviews.

<comment><AUTHOR> This is something like the 10th post about the CS lectures. Look at the right sidebar for all the others. I remember posting see.stanford.edu lectures a while ago.

<comment><USER2> Ahh ok, thanks for that. It's amazing what's out there for free these days.

<comment><AUTHOR> Yep. You can be your own university nowdays.

</comment></comment></comment></comment><comment><USER3> This is nice. Though I think <http://www.openculture.com/> is more comprehensive and Dan Colman's been doing this for quite a while now, with no signs of stopping :-)

</comment><comment><USER4> <http://www.reddit.com/r/csbooks/> is a useful subreddit for tons of free Computer Science ebooks.

</comment><comment><USER5> Some really nice quantum computation notes: <http://www.doc.ic.ac.uk/~ae/papers/qc.pdf>

</comment><comment><USER6> Better than <http://personalmba.com/recommended-business-books/>

</comment><comment><USER7> Thanks a Lot. This is really good. Especially I was looking some thing in datamining

</comment><comment><USER8> Great ressource

</comment><comment><USER9> Thanks a lot. Looks quite interesting.</comment>


Disney+ Might Have a Notable Hacker Problem - <AUTHOR> https://fortune.com/2019/11/18/was-disney-plus-hacked-users-accounts-access/ <comment><USER2> Extra fun tip I'm sort of nervous putting out there just because it's a potential attack vector: if you used the same email address as your existing MyDisneyExperience account, guess what? The password you set while registering for Disney+ is now the password for your MDE account - they were "merged" without notification (that I saw). So not only is your Disney+ account compromised, potentially the account you use to book vacations is as well.

EDIT: I have "merged" in quotes because I am not sure if changing your D+ email changes it for your MDE account as well, or vice-versa.

<comment><USER3> > I have "merged" in quotes because I am not sure if changing your D+ email > changes it for your MDE account as well, or vice-versa.

If the merger of Disney Movie Rewards and Disney accounts, or the merger of Marvel and Disney accounts are any indication to go by, it's likely forever to always be a mess. Disney's goal for "one account system" has just been one wild ride after another. Given how many of their websites still in 2019 redirect to or through *.go.com for reasons unknown, I have to imagine their web tech stack is a fascinating archeology dive under the hood.

</comment></comment><comment><USER4> With 10m moms and dads signing up, I'm going to guess this is largely due to password reuse from prior hacks. Christmas123.

<comment><USER5> It does seem like a particularly soft target in that regard.

We really need a 2FA solution that's friendly enough for normal people to use. Like, _yesterday._

<comment><USER3> We really need even just a 1FA solution that's friendly enough for normal people to use _securely_. Passwords clearly aren't secure for normal people, and we should stop pretending like they ever were.

</comment></comment></comment><comment><USER6> The email change is particularly disturbing. A good security design would be to send the old email a notice of change request and give them a link that can always be used to undo that change (which might require the at the time older password as well).

<comment><USER7> Most services don't do that. I have had my personal email account DDoSed before and requiring access to that inbox to change my email address would have been impossible for over a month.

</comment></comment><comment><USER8> Does anyone else still torrent?

I rarely watch a tv show or a movie, but when I do I just torrent it. I've been doing this since Limewire (which was a lot of really shitty porn at the time).

Showed my boys Princess Mononoke the other day - will show them the Mandalorian tonight, a buddy told me its pretty good

<comment><USER9> Does anyone still shoplift? /s

Yes, people still steal. Torrenting is usually more convenient, but for media that actually cost a ton of money to produce, I still feel iffy about stealing it. I would never recommend it to anyone when buying and paying for media is still an option.

Even if something like Ghibli movies might not conveniently be available for on-demand streaming, I still think everyone is under the moral obligation to plan ahead and buy it on a more traditional format rather than to resort to piracy. It is your own short-sightedness if you can't anticipate the need beforehand and order it in time.

If for some reason media can't be bought new anymore and your money isn't good anywhere, then by all means pirate it. I consider that it has at that point entered a public domain of sorts.

<comment><USER10> Piracy isn't stealing. Many people have been over this. You've been brainwashed if you think it's stealing.

It's still against the law in many places, but to call it stealing is just spreading misinformation and propaganda.

<comment><USER11> Hmm - is there a good summary of this argument I could read? I torrented many years ago and it always felt like stealing and still does. Seems more or less equivalent to shoplifting to me from a moral standpoint, would be curious to read into this!

(I'm assuming this is not the "oh I actually pay and I just want to watch it on an unsupported device" argument)

<comment><USER12> If I shoplift a bag of Doritos, the shop has one fewer bag of Doritos.

If I pirate a show, it doesn't disappear from Disney's hard drives.

<comment><USER13> People use "steal" like that all the time. "You stole my idea." "He stole my look!" "She stole my song." Etc... So I don't really think that's a very good argument.</comment></comment></comment></comment></comment></comment>


Pay for Uber with Bitcoin - <AUTHOR> https://bitcoinbuilder.com/uber/ <comment><USER2> Anonymous business. No street address. Not in Dun and Bradstreet. "Private registration" domain. And they want you to deposit money with them. Yeah, right.

<comment><USER3> > Anonymous business. No street address. Not in Dun and Bradstreet. "Private > registration" domain.

This will be more and more common and isn't a bad thing. None of those provide any real safeguards and frankly, private domain registration is pretty common. I wouldn't dump > a half weeks paycheck in there, but measuring risk and reputation will no longer be a simple BBB or Dun and Bradstreet lookup.

<comment><USER4> "None of those provide any real safeguards". Don't you feel like this is an overstatement? Like if Microsoft commits a fraud I can sue Microsoft. Like yes it's possible that in the future these safeguards wont' be available, but having real legal entities with known individuals you can have a trust based relationship in society is of tremendous value. Knowing that your counter- party in a transaction has repetitional risk is definitely beneficial.

<comment><USER5> ... and frankly, at least in a country with a stable legal system, it's a slight bit of comfort to know that if all else fails (hopefully it never reaches that point of course), the police can go and arrest somebody that caused us harm, and/or seize their assets.

</comment></comment></comment></comment><comment><USER6> Bitcoin Builder started out as a way to trade against MtGox's internal ledger when they halted withdraws. Users could effectively bet on MtGox's future by using privately held bitcoins to trade with users wanting to sell their "Gox coins" at a fraction of the market price. Anyone that sold their Gox coins for less than 100% market value made out far better than those that didn't. It was a wild idea that basically created a functional market for the greedy and the desperate. I'm sure millions flowed though the site during its short lived existence.

Congrats on the new idea, Josh.

<comment><USER7> Thanks jron!

</comment></comment><comment><USER8> Awesome, and works very smoothly. I really hope that uber won't ban it. Or even better, I really hope that uber would implement a system where you would be able to convert bitcoins directly to uber credit :)

<comment><USER9> is there a reason why uber would want to ban it?

<comment><USER10> I can think of two cases.

\- the first time there was a confusing instance of chargeback/dispute resolution.. it's easier to say "this is a TOS violation" than to "figure it out"

\- if the total amount coming from this account makes different taxes/regulations apply that aren't beneficial to uber

<comment><USER9> good points, thanks!

</comment></comment></comment></comment><comment><USER11> I wonder what happens if you try to charge them for a ride which costs more than you have in your account. They require a $25 balance, but you can certainly go on much more expensive rides.

<comment><USER8> The bitcoinbuilder option will automatically disappear, when your balance goes below certain amount. I would guess they would ban accounts which do that permanently. Anyway, there probably are lots of users who are very happy to use this system fairly, such as me.

</comment></comment><comment><USER12> Awesome service! I've already used this for four rides: [https://i.gyazo.com/b6ba0bd02566eb7eb54781411b322bbd.png](https://i.gyazo.com/b6ba0bd02566eb7eb54781411b322bbd.png)

</comment><comment><USER13> It's Uber for Bitcoin! Oops, I mean Bitcoin for Uber! Wait no, it's like Paypal for Bitcoin for Uber...

These analogies are really messing with me. :)

</comment><comment><USER14> This will work greatly in India, most of my Indian friends say that most Indians don't have credit cards/prefer to pay with cash.

<comment><USER15> Doesn't Uber India have cash payments?[http://techcrunch.com/2015/05/11/uber- is-testing-cash-paymen...](http://techcrunch.com/2015/05/11/uber-is-testing- cash-payments-in-hyderabad-india/)

<comment><USER16> Yep..

[http://techcrunch.com/2015/07/21/uber-gets-serious-about- cas...](http://techcrunch.com/2015/07/21/uber-gets-serious-about-cash- payments-in-india/)

And the Uber design post about how they made it work (in broad terms);

[https://medium.com/uber-design/designing-the-uber-cash- exper...](https://medium.com/uber-design/designing-the-uber-cash- experience-649a2749b324)

</comment></comment></comment><comment><USER17> Really nice workaround until Uber accepts Bitcoin itself.

My only concern:

Does your rides and personal information (eg. name and phone number) become available to Bitcoin Builder through the Uber Business backend?

<comment><USER18> Good point. According to Uber's website:

> Your company will see trip information about rides that were charged to > their Uber for Business account, including pickup location and destination, > product type, time of day, and duration.

<comment><USER7> Your name and phone number don't get revealed, but yeah, like Uber says, they do give us the information above. I can promise we don't do anything with it?

</comment></comment></comment><comment><USER19> This is as close to a frictionless bitcoin transaction (at least in situ) as I've seen yet in the context of useful, frequent payments.

</comment><comment><USER20> I guess don't get the problem that this is solving. Isn't Uber rolling out a cash option?

<comment><USER7> I think that was only for a few cities in India?

This works everywhere uber works. Today!

</comment></comment><comment><USER18> I don't see a mention of how much the service costs; what fees they charge. Perhaps that becomes transparent after creating account, but it's probably important information to have immediately available.

<comment><USER7> Ah, that's because there are no fees!

But, we should probably make that clear!

</comment></comment><comment><USER21> Used this yesterday and today here in the Philippines! This is an awesome workaround because only 3% of Filipinos have credit cards [https://www.techinasia.com/is-southeast-asia-ready-for- onlin...](https://www.techinasia.com/is-southeast-asia-ready-for-online- payments/)

</comment><comment><USER22> This website is really ugly. I wish they had put some time into at least making it look nice.

</comment><comment><USER23> That is super cool, and has the coolest website for it.</comment>


Tools for Conviviality (1973) [pdf] - <AUTHOR> https://co-munity.net/system/files/ILLICH%201973_tools_for_convivality_1.pdf <comment><USER2> We are organizing a workshop using Illich's concept of conviviality to discuss the future of software. [https://2020.programming- conference.org/home/salon-2020#Call...](https://2020.programming- conference.org/home/salon-2020#Call-for-Submissions)

</comment><comment><USER3> My favorite living tech critic has a newsletter, _The Convivial Society_ [1], based on the title of this book and Ellul's The Technological Society. Highly recommend it for people who want serious philosophical context to current events.

[1]:[https://tinyletter.com/lmsacasas/archive](https://tinyletter.com/lmsacasas/archive)

</comment><comment><USER4> An interesting coincidence, because right now I'm reading Anti-Oedipus, where Deleuze & Guattari argue against (nowadays ubiquitous) neurotic dependency on professionals, against capitalist society based on segregation with exclusion, and in favor of reversing the relationship between man and its machines -- they call this process of reversal "desiring-revolution" and IIRC explicitly mention Illich's concept of "deschooling" as one of the inspirations.

The book itself is hard as nails to read, and at times either reeks with militaristic tones (from Guattari) or derails into fart jokes over psychoanalysis, but, all in all, is a very, very worthwhile and inspiring read (esp. then authors peruse concepts from dynamic systems theory, cybernetics and biology). I hope to finish it ASAP and move on to Thousand Plateaus, which, according to some comments, is a more thought-out and balanced (i.e. pure 50/50 hybrid between Deleuze and Guattari, instead of Guattari interspersed with Deleuze) version of Anti-Oedipus.

Maybe some of you will find this reference useful.

</comment><comment><USER5> Upvoted for Ivan Illich. He was on the cover of a 1993 issue of the Coevolution Quarterly and was a minor celebrity for a while. One of the deepest thinkers we've ever had.

<comment><USER6> Looks like it was Winter 1983:

[http://www.davidtinapple.com/illich/1983_silence_commons.htm...](http://www.davidtinapple.com/illich/1983_silence_commons.html)

This is about it too: [https://just.thinkofit.com/ivan-illich-silence-is-a- commons/](https://just.thinkofit.com/ivan-illich-silence-is-a-commons/)

<comment><USER5> Yes, it looks like the author had a follow up column to Illich's essay. That's very interesting. Thanks for sharing this.

I attended the Whole Earth 50th anniversary at Fort Mason a couple years ago, and noticed that Illich's name, and those of others like Ken Kesey and John Perry Barlow were mentioned on an 'In Memoriam' plaque for the event. It's interesting to think that he had an equally profound impact on this group of people, who have shaped so much of our culture. His work is always worth another look.

One essay of his that I come back to more than any other is 'To Hell With Good Intentions'. The great man delivered this speech to a group of wide eyed college students who were about to go to Mexico for an aid program and just took a big crap on them. I wish I had been there. I used to share it with friends before they went on vacation.

He was a chemist/crystallographer, and a deeply spiritual Catholic who advocated for the rights of nuns to kill themselves, and a very tactical anarchist. Rest In Peace!</comment></comment></comment>


All-In-One Messenger 2.0 released - Gmail, Instagram, FB, Whatsapp ... - <AUTHOR> https://allinone.im <comment><AUTHOR> operates like Franz ([https://meetfranz.com](https://meetfranz.com)), but much more simple and minimalistic with less CPU usage.

Beside all the common messenger it supports new messenger like Instagram, Tinder etc. - Signal and "planed Messages" are the next goals.

I personally like to have my Gmail account isolated from my default browser and stay logged out of Google while browsing the web.

It's free and feedback is greatly appreciated! :)</comment>


Free music downloads site in chaos as record giants pull out - <AUTHOR> http://www.thisislondon.co.uk/news/article-23434386-details/Free+music+downloads+site+in+chaos+as+record+giants+pull+out/article.do <comment><USER2> My understanding is that they never had the record companies signed to begin with. It seems like they were trying to force their hands by issuing a press release, which obviously didn't work.</comment>


Can hustle be taught? - <AUTHOR>

Firstly, how simple is it to convey what this oft-used buzzword actually means?<p>More importantly, how can you actually go about teaching what many think is an intrinsic part of your being? <comment><USER2> No, hustling can not be taught.

Hustle means many different things. Depends on how you were brought up and reared. Growing up i used to shineshoes and had to fend for my own. So what i deem as huslin', is much different then the hustle that is talked about in regards to sports, of the startup hustle. Hustin' for me, notice "hustin", opposed to hustling, is going to the book store after work shiningshoes each day and learning about the different keywords i picked up while shining the shoes of the guys who were taking shit. I would listen and get the job done all while getting a education.

My desire was to learn what was being discussed. In this case, the hustle i developed is not a hustle that can not be taught. Many people are lazy because they have had certain kinds of resources provided to them. When a person doesn't have resources they have to make do and develop without the resources.

Hustle can not be taught, nor can it be purchased. It's a natural gift that is born out of passion, desire, and inspiration from a specific set of circumstances. When these circumstances are aligned then the ingredients are perfect and a person can have hustle. Just because one person can out talk another doesn't mean they have hustle. It just means they have a much broader vocabulary and a set of different experiences to pull from.

I have had many experiences dealing with people who have judged me to varying degrees because of have and use language in a very interesting way. What they have failed to realize is that anything that i bring to the table is an assert. Most have preconceived notions about certain people which are detrimental to many different processes. If they would simply set their shit to the side and see that some of the people who have some of the most brilliant ideas come from a set circumstance far beyond their own life experience. Once they can do this the possibilities can grow like ivy.

Some of the best conversations i have had with people have been when i was hustlin'. Not because i was on a quest to get money. It's because i set my own judgements and prejudices aside and appreciated the moment. Simply, because it was a way to get out what was in side that was stored up and build up as energy.

I say all this to say that [hustling]/hustlin' = passion if a person doesn't have passion, they will never be hustlers.</comment>


Quantum Computing Explained - <AUTHOR> http://www.clerro.com/guide/580/quantum-computing-explained <comment><USER3> We are currently living in an exciting time for quantum computing. Most leading companies like Google and IBM have 20 qubit devices. IBM has a 50 qubit prototype [0].

Google has plans to show quantum supremacy in the next couple of months: where a quantum computer will perform a task that cannot be simulated on a classical computer [1]. These near-term (5-10 year) quantum computers will likely be used for simulating quantum chemistry and solving optimization problems [2].

[0]: [https://www.technologyreview.com/s/609451/ibm-raises-the- bar...](https://www.technologyreview.com/s/609451/ibm-raises-the-bar- with-a-50-qubit-quantum-computer/)

[1]: [https://www.technologyreview.com/s/609035/google-reveals- blu...](https://www.technologyreview.com/s/609035/google-reveals-blueprint- for-quantum-supremacy/)

[2]: [https://www.nature.com/news/commercialize-quantum- technologi...](https://www.nature.com/news/commercialize-quantum-technologies- in-five-years-1.21583)

<comment><USER4> Number of physical qubits is not a meaningful measure of computational power, especially since fault tolerant computation has not been demonstrated. (In the limit of large errors, a physical qubit has zero computational power.)

D-Wave has a 2000-qubit machine.

<comment><USER3> Yes. The researchers at IBM don't use the number of qubits as a measure of the quality of the computer. They use the quantum volume [0]. I said 50 qubits because I was just parroting the press release. The reason I didn't mention D-Wave's machine is because it is not a universal quantum computer. It is a quantum annealer [1].

Google and IBM want their qubits to be of high quality (high coherence times e.t.c). One of the big obstacles right now is scaling up the number of qubits while making sure that their quality is high.

[0]: [https://en.wikipedia.org/wiki/Quantum_annealing](https://en.wikipedia.org/wiki/Quantum_annealing)

[1]: [https://www.research.ibm.com/ibm-q/resources/quantum- volume....](https://www.research.ibm.com/ibm-q/resources/quantum-volume.pdf)

</comment></comment></comment><comment><USER5> Here is another introduction that actually uses a quantum computing Python API to explain the fundamentals of quantum computation [0], geared to a programmer audience.

[0] [http://pyquil.readthedocs.io/en/latest/intro_to_qc.html](http://pyquil.readthedocs.io/en/latest/intro_to_qc.html)

</comment><comment><USER6> Very well done. Short, yet covers all the necessary details.

Shameless plug, check out my book [https://www.amazon.com/dp/0992001021/noBSLA](https://www.amazon.com/dp/0992001021/noBSLA) for an in-depth view of the linear algebra background necessary for quantum computing.

If you know linear algebra well, then quantum mechanics and quantum computing is nothing fancy: just an area of applications (See Chapter 9 on QM). Here is an excerpt: [https://minireference.com/static/excerpts/noBSguide2LA_previ...](https://minireference.com/static/excerpts/noBSguide2LA_preview.pdf#page=125)

<comment><USER7> I'm definitely going to check your book out, but in the mean time I was wondering if you could help me zort something out from this article. Author states:

Check these quantum states out as examples, which cannot be broken into a tensor product of two other states, they are unseparable -

Ex.1: 1/sqrt(2)∣00⟩ + 1/sqrt(2)∣11⟩ !=∣ψ1⟩⊗∣ψ2⟩

Ex.2: 1/sqrt(2)∣01⟩ − 1/sqrt(2)∣10⟩ !=∣ψ1⟩⊗∣ψ2⟩

So, in all previous 2 qubit examples he showed yielded 4 states (00, 01, 10, 11). Is the author saying that some two-qubit systems can be achieved such that not all 4 possible discrete states can participate in superposition? (i.e. in the system of ex. 1, states 10 and 01 are not possible and in ex. 2, states 00 and 11 are not possible?)

<comment><USER6> The four states |00⟩, |01⟩, |10⟩, |11⟩ form a basis so _any_ two-qubit state can be written as a linear combination of these vectors: ∣ψ⟩ = a|00⟩ +b|01⟩ +c|10⟩ + d|11⟩. If a certain coefficients in the linear combination are zero, e.g., b and c for the 00+11 state, or a and d for the second one, this doesn't have any special meaning.

The classification of states as separable vs entangled refers to the existence of a local description for the two qubits. Remember that |00⟩ is shorthand for |0⟩⊗|0⟩, meaning the state of the two-qubit system when qubit 1 is in state |0⟩ and qubit 2 is in state |0⟩.

Separable states can be written in the form (α|0⟩+β|1⟩)⊗(γ|0⟩+δ|1⟩) = ∣ψ1⟩⊗∣ψ2⟩. Note there is a clear local description for the first qubit ∣ψ1⟩ and and a separate local description of the state ∣ψ2⟩. If Alice prepares her qubit 1 in the state ∣ψ1⟩ and Bob prepares his qubit 2 in the state ∣ψ2⟩ then the combine description of their two qubits is what's shown above. The state of the combined system is describable as the tensor product of two separate local descriptions.

Entangled states, on the contrary, are states that cannot be described as the tensor product of two local descriptions. Specifically, there exist configurations a,b,c,d for a two-qubit quantum system such that

          a|00⟩ +b|01⟩ +c|10⟩ + d|11⟩   ≠   (α|0⟩+β|1⟩) ⊗ (γ|0⟩+δ|1⟩)

no matter what choice of α,β,γ,δ you make. The phenomenon of entanglement is a quantum-only thing, that can't really be understood via classical analogies, since classical systems can necessarily be described as the combination of two local descriptions. The examples given are two of the four Bell states, see [https://en.wikipedia.org/wiki/Bell_state](https://en.wikipedia.org/wiki/Bell_state) , but there are many more entangled states. Here is a concrete physics example [https://en.wikipedia.org/wiki/Singlet_state#Singlets_and_Ent...](https://en.wikipedia.org/wiki/Singlet_state#Singlets_and_Entangled_States)

Interestingly, many of the quantum computing experiments perform involve the manipulation of entabgled states because they serve as proof that something quantum is going on...

<comment><USER7> Holy smokes - that is an amazing response! I can't claim that I'm fully grasping the mathematics of entangled vs separable states at this moment, but what you've written seems very clear and I think if I go through it a few more times with the links, I may finally get it after all these years of bewilderment. Thank you!

</comment></comment></comment></comment><comment><USER8> This is an excellent introduction to quantum computing. I didn't see where I could sign up for updates. I'd like to follow this!

</comment><comment><USER9> So take what I'm about to say with a grain of salt but I believe that current generation of quantum computers (quantum digital) is fundamentally flawed. Basically all architectures I've seen still use bits (qubits are still bits and use entanglement) as opposed to the superior signals. The class of computers I'm talking about is called continuous-variable quantum computers ([https://en.wikipedia.org/wiki/Continuous- variable_quantum_in...](https://en.wikipedia.org/wiki/Continuous- variable_quantum_information)). Unlike DQ, it doesn't use entanglement.

They are similar to the old school analog electric computers. They have some interesting properties and I can actually imagine programming one unlike DQ.

There's a fourth class, continuous analog with entanglement which are superior to both, DQ, and continuous-variable quantum computers but right now we should really be looking into the continous variable ones.

<comment><USER10> There is a serious misconception in your claim. Yes, analog computers, whether quantum or classical solve even NP-complete problems in polynomial time. No, they can not be constructed in the real world because analog computing does not permit error correction, and in the real world you have to deal with noise. Only very small analog computers (nothing scalable, nothing solving general problems) can be constructed before noise becomes an issue.

Three good references:

Book on quantum and classical computing: Aaronson's "Quantum Computing since Democritus" for gentle-for-newbies but rigorous discussion

Very old paper on classical computing (analog vs digital): Von Neumann's "Probabilistic logics and the synthesis of reliable organisms from unreliable components" (pretty advanced)

Newish (old for the field) paper on quantum computing: Calderbank's "Good Quantum Error-Correcting Codes Exist"

Edit and addition: I work at Yale's Quantum Institute and we are some of the biggest proponents of "continuous variable" quantum computing. We use the continuous variables to encode a discrete "qudit" (with a "d") representation for the information, for all the reasons mentioned above (noise and error correction).

<comment><USER11> I love Aaronson's book but it's not "gentle-for-newbies". Not because it's not gentle! It just explicitly skips over a lot of the material. You're expected to already know about quantum computing since he doesn't feel he can add to existing authors on the subject. Instead, it's really a survey of quantum _complexity theory_ , with some sampling of background material where the author felt he had something new to say.

<comment><USER12> What's a good book for Quantum Computing? When I took Aaronson's class last semester I got so wrecked by everything, and it just felt like everything was so conflicting from many different resources

<comment><USER11> I learned from a coursera course some number of years ago. It was actually quite good. (This should also give you the correct impression that I am _not_ an expert here and you should take my suggestions with a grain of salt.) I think it was this one: [https://www.edx.org/course/quantum-mechanics-quantum- computa...](https://www.edx.org/course/quantum-mechanics-quantum-computation- uc-berkeleyx-cs-191x) (Taught by Aaronson's advisor.)

</comment></comment></comment></comment></comment><comment><USER13> IBM lets you poke around one of their quantum machines here for free:

[https://quantumexperience.ng.bluemix.net/qx/experience](https://quantumexperience.ng.bluemix.net/qx/experience)

They also include a brief tutorial on how to program for it too.

<comment><USER14> AFAIK this is a simulation, not real quantum machines.

<comment><USER15> They have both a simulator and real machines you can use. The "ibmqx5" is a 16-qubit device. The problem is that noise rates are very high. For example, just to swap two adjacent qubits (using three CNOT gates), it looks like you will incur at least 10% error. It is hard (though not impossible) to run meaningful experiments on such a noisy system.

[https://quantumexperience.ng.bluemix.net/qx/editor](https://quantumexperience.ng.bluemix.net/qx/editor)

<comment><USER14> Oh, thanks. You are correct that it is very noisy. Just a single CNOT is giving me 15% error.

<comment><USER15> Here are the numbers for their latest 20-qubit device. CNOT error rates are a bit lower. I don't know if they plan on making this publicly accessible.

[https://youtu.be/T-8uuq7Izl8?t=26m36s](https://youtu.be/T-8uuq7Izl8?t=26m36s)

</comment></comment></comment></comment></comment><comment><USER16> Maybe a stupid question but does anyone here know how quantum computing would effect bitcoin/crypto in general?

<comment><USER17> Unless you can find a way to implement a way to reverse a hash efficiently using a quantum algorithm, I wouldn't hold my breath.

<comment><USER18> Would a quantum computer be capable of brute forcing private keys?

</comment></comment></comment><comment><USER19> Quantum computing is _way_ beyond me but I found this video by Kurzgesagt really interesting [https://youtu.be/JhHMJCUmq28](https://youtu.be/JhHMJCUmq28)

</comment><comment><USER20> Will quantum computing kill Bitcoin by rendering the underlying cryptography obsolete?

<comment><USER21> I understand there are two ways Bitcoin is affected by a crypto quantum- computer:

1) A QC is able to derive the private-keys for a wallet's public address, allowing for the theft of bitcoin

2) A QC able to perform the proof-of-work algorithm to mine new blocks at an order-of-magnitude faster rate than currently possible.

Fortunately for 1) (I think) it currently takes 2^512 (?) operations to break the private/public algorithm which is unfeasible to brute-force on normal hardware but a QC brings it down to 2^128 - but that's still on-the-order-of unfeasible - and in the event it ever does happen the blockchain could be changed overnight to use a new keying algorithm. And for 2) it would cause the blockchain difficulty to be pushed-up so high that people with QC machines would see the same ROI as today's industrial GPU and ASIC miners see - <USER2> given that QC computers are horrendously expensive (think: billions of USD for a 50-bit general-purpose QC) it questions why you'd ever try to break Bitcoin as you'd already be a billionaire.

<comment><USER14> > Fortunately for 1) (I think) it currently takes 2^512 (?) operations to > break the private/public algorithm which is unfeasible to brute-force on > normal hardware but a QC brings it down to 2^128

Where have you got that info? Quantum computers can break ECDSA in polynomial function of 512.

> the blockchain could be changed overnight to use a new keying algorithm.

How?

</comment></comment></comment><comment><USER17> Whatever you do, don't invest in quantum computing.</comment>


Israel's NSO: the business of spying on your iPhone - <AUTHOR> https://www.ft.com/content/7f2f39b2-733e-11e9-bf5c-6eeb837566c5 <comment><AUTHOR> [https://twitter.com/FT/status/1128148984143470592](https://twitter.com/FT/status/1128148984143470592) readable via here

</comment><comment><USER2> NSO is fundamentally an unethical organisation.

Ignoring their deliberate targeting via "detectives" and their attempts to create an anti-Israel story, they willingly sell goods to countries that are known to violate human rights. We know this because the same customers have repeatedly been caught using their software to deliberately attack human rights workers.

</comment><comment><USER3> It's hard to actually read the article, but the gist of it seems to be that firms are using regulatory arbitrage to sell hacking services to foreigners. It seems inevitable that some jurisdictions will allow this sort of thing.

I'm curious about whether anyone in the US is allowed to hire outfits like this, and what happens if they get caught. Is it ever legal for me to hire a hacking service that does things that are illegal for me to do? What, if anything, can US citizens do to become authorized to do similar things domestically? US security contractors sort of seem like have more leeway then I do, but maybe they just have LLCs and good lawyers?

An understanding of this part of the business environment should inform our security assumptions. Does anyone know more about the rules for this kind of stuff?

<comment><AUTHOR> 'NSO has been selling the ability to hack mobile phones in any part of the world — most recently using WhatsApp — with geographical software limitations decided by the Israeli government, according to a person familiar with the company. That means that a spy agency in one country can theoretically hack phones well outside their jurisdiction'

<comment><USER2> Yup! We know their software was being used (in the case of pegasus) against human rights activists in the UAE.

We know that they literally sent disguised detectives to "interview" human rights activists and security researches at Citizen Lab in Canada (U of Toronto).

I can't imagine working for a company like this.</comment></comment></comment>