Afraid of Your Child's Math Textbook? You Should Be. - <AUTHOR> http://open.salon.com/blog/annie_keeghan/2012/02/17/afraid_of_your_childs_math_textbook_you_should_be <comment><USER2> It's silly to have churn in the publishing market with ever new approaches, all of which are known to be less effective than proven methods of learning math that have been known for hundreds of years.

Just use the Singapore Math series for K-6 and be done with it. Sound pedagogy, known to work, has been debugged, no frivolous cutting edge theories from M.Eds who have never taught math successfully.

<comment><USER3> > all of which are known to be less effective than proven methods of learning > math that have been known for hundreds of years.

[Citation needed]. The methods my kids currently use, seem more effective that the ones I used at school. I am in my late 40s.

edit: I'm based in the UK, however.

<comment><USER2> 1\. My personal experience as a teacher.

2\. The average state of math knowledge of contemporary american high school graduates, coupled with statistics on needed remedial education for college entrants with high school diplomas.

Teaching math is easy. I can teach any kid math. It's not a problem at all because we know how to do it. Many countries do it successfully. Observing what schools are doing, the textbooks, the approaches, and the level of math competency of elementary school teachers completely explains what is going wrong. It's not a mystery. Also explains why kids homeschooled by parents, even parents who were high school drop outs, end up with considerably better math skills than most public school graduates, and even many private school graduates.

Typical high school graduates don't understand fractions, percentages or decimals. They can't do division. They don't understand algebra at all. We know this is true because of college placement tests.

This is absurd. 100% of high school graduates should have passed differential and integral calculus. That should be the minimal acceptable standard. That it is not, and that graduates fail at even moderate arithmetic skills, shows the complete failure of the system.

Downvote all you want while shouting "the dedicated teachers are not the problem, the students and their parents are!" That won't change a thing. Meanwhile, those who utilize proven approaches succeed and those who make excuses and follow fads fail.

<comment><USER4> Out of curiosity, why is it that you would prioritize differential and integral calculus? I studied calculus very early myself, but outside of later classwork, I've only found it useful on rare occasions. I surely would have used it more if I had gone into a research job or into material sciences, but I estimate that very, very few careers are like that.

What would have been much more useful for me would have been a stronger grounding in statistics.

<comment><USER2> I didn't mean to prioritize it, I'm saying that level of understanding should the goal of average achievement for high school graduates.

It is also really really far from what is being accomplished on average. High schools have seniors who can't do division and don't understand operations on fractions. Calculus is something anyone can understand, but it is seen by teachers as some super advanced mysterious stuff for rocket scientists while they struggle along to teach subtraction to 18 year olds.

Imagine a physical education fitness curriculum whose goal after 13 years of training was for 18 year olds to be able to turn over by themselves and begin to crawl. That's what we are doing, being satisfied with goals for graduates that shouldn't be challenging even for 6 year olds. It shouldn't be tolerated at all.

Schools that are graduating students with no math skills have had 13 years of failed instruction with these students. Not just one teacher along the way. All of them. The system should be burned to the ground and started over. That will never happen though, it's too corrupt and incompetent. Myself I've given up hope reform of the system is possible.

<comment><USER5> Speaking as a recent high school graduate, please, _please_ don't give up. I made it out of school knowing calculus and more because I had one physics teacher and one math teacher that hadn't given up. They wrote their homework themselves, used college textbooks and twenty-year-old texbooks they'd collected from eBay, and railed constantly at the district's purchasing people. They weren't able to change the system all by themselves, but they still made - and continue to make - all the difference for dozens or hundreds of students. You can do the same. Please.

</comment></comment></comment></comment></comment></comment><comment><USER6> I was the only person my cousin could turn to for help when he was taking math in high school. When he asked me for help, my first instinct was to help him find the relevant information in his textbook. But the textbook wasn't helpful at all. First, he was often working with things that weren't indexed; even though his homework was from the textbook's supplemental materials. Then, the text was hard to understand. It just wasn't written very well. Finally, the whole thing was just too busy, with many different fonts, all sorts of margin notes, many footnotes, and colored boxes surrounding text. This made finding information harder and just gave me a headache.

<comment><USER7> I had the same experience. My little sister just finished HS a year or two ago, and I helped her with her homework quite a few times.

The books were useless. It was nearly impossible to find concepts in it, and when you did the description was often relatively short, relying on an example that was often poorly constructed.

In the end, if the book didn't jog my memory I would have to Google the concept to find a better page. The book might as well have been nothing but problem sets.

I never met any of her teachers. I got the impression that at least one of them wasn't qualified to teach math, but that was 2nd hand information through the lens of my sister, so I can't be sure how accurate it was.

</comment></comment><comment><USER8> I guess if you ever try to fix a problem by throwing money at it, there will always be someone there to intercept it. I think this has helped articulate for me exactly _why_ "throwing money at a problem" is so bad: because it attracts the kind of people who chase after large sums of money, not the kind of people who fix problems.

(People always deride others in debates and arguments for "throwing money at the problem", but they never stop to explain why it is a bad thing. Now I know.)

<comment><USER9> You make a very good point. Although I would add that money does play an important role as well. The article mentions that qualified writers and educators are leaving the field because the pay is so ridiculously low.

I suppose that what this shows is that simply "throwing money at the problem" is not a good thing. You have to throw money at people who are genuinely driven to solve the problem.

<comment><USER8> Yes the problem is when you "just" throw money at the problem without detailed oversight by someone who cares about the problem and can get the money to the right people.

</comment></comment></comment><comment><AUTHOR> Earlier Hacker News submission about teachers in Minnesota writing their own textbook to state curriculum standards, by forking an appropriately licensed online textbook series:

<http://news.ycombinator.com/item?id=3203857>

<comment><USER10> The link to that newspaper article says "story no longer available".

<comment><AUTHOR> Thanks for letting me know. This

[http://minnesota.publicradio.org/display/web/2011/11/06/onli...](http://minnesota.publicradio.org/display/web/2011/11/06/online- textbooks/)

appears to be a working link, from a website better about keeping links alive, to the same AP news story.

</comment></comment></comment><comment><USER11> I met a 10 year old child with Asperger's[1] who was trying to do some math homework. The book was wrong; they hadn't labelled a diagram but were asking for those labels in the answers.

Maybe some children would have worked out to create their own key or to write in the book, but this boy just stopped. An activity that he's good[2] at, that he enjoys, is being slowly poisoned by poor quality materials.

It's not just math books either. Where's the Feynman quote about the horse evolution?

[1] Proper diagnosis from a set of real doctors. [2] Got a scholarship to a decent school partly based on his math ability.

<comment><USER12> I'm not sure that a kid with Asperger's stopping when they encounter a problem leads to the conclusion that "[math] is being slowly poisoned by poor quality materials."

<comment><USER11> You're right. I meant to say that for him, his enjoyment is being slowly poisoned.

</comment></comment></comment><comment><USER13> _One math exercise in a chapter I was assigned called for students to use a math formula to calculate their level of attractiveness, using a mathematical ratio of 1:1.618 (otherwise known as phi or divine proportion), a formula scientists have devised to set standards of beauty. Math can be tough enough for some kids without having to learn that, on top of struggling to apply math formulas to their face, they are also inherently unattractive. Talk about installing math phobia!_

First, I think he meant _instilling_ math phobia.

And second, this "golden ration == attractiveness" myth is un-scientific and an urban legend perpetuated by Dan Brown and similar authors.

</comment><comment><USER14> Why do we need more maths textbooks in the first place? I can't imagine there's new branches of maths that we need to teach school kids about. (and same goes for a lot of other subjects)

<comment><USER15> I've wondered why there isn't a set of national texts available for core math and science subjects. They're pretty stable subjects. So at one point I decided to find out what the mission of the Dept. of Education is, and the shocker (to me, at least) was the following little blurb from the ed.gov website.

"In creating the Department of Education, Congress specified that:

No provision of a program administered by the Secretary or by any other officer of the Department shall be construed to authorize the Secretary or any such officer to exercise any direction, supervision, or control over the curriculum, program of instruction, administration, or personnel of any educational institution, school, or school system, over any accrediting agency or association, or over the selection or content of library resources, textbooks, or other instructional materials by any educational institution or school system, except to the extent authorized by law. (Section 103[b], Public Law 96-88)"

So even if we wanted to have national standards for math textbooks, the Dept. of Education is prohibited by law from doing so.

<comment><USER16> Hello All from the UK

[http://www.education.gov.uk/schools/teachingandlearning/curr...](http://www.education.gov.uk/schools/teachingandlearning/curriculum/secondary)

The alternative is to specify the National Curriculum and then second guess the changes each time the government changes.

School maths is a socially determined thing. It has little to do with mathematics in University departments or the ways in which mathematical reasoning is used in other areas of life. Definitions vary.

PS the new textbooks by pearson, stanley thornes, longman &c are relatively error free.

</comment></comment></comment><comment><USER17> > That math homework you're trying to help your child muddle through might > include problems with no possible solution. It could be that key information > or steps are missing, that the problem involves a concept your child hasn't > yet been introduced to, or that the math problem is structurally unsound for > a host of other reasons.

That sounds an awful lot like reality. Not that I think it's a great way to teach maths (though maybe it is a great way to teach problem solving) but an educated adult should have little trouble spotting the missing information or contradictions and either guessing, pointing out, or assuming them away.

I realize that it wasn't intentional on the part of the authors (neither are real problems), and that it's not the point of the article but merely a hook.

<comment><USER18> Open-ended questions and problems are awesome. However, typically book work is intended to be rote practice of an algorithm. Already it is not a simulation of the real world - typically the real world open ended problems are cross- disciplinary and much larger in scope than a context-free simple arithmetic algorithm. That is not the point of book work, and when students go in expecting problems to be internally consistent, sound, solvable, and to behave the way the teacher told them, it can hamper learning as they have had the proverbial rug pulled.

<comment><AUTHOR> _Open-ended questions and problems are awesome._

Open-ended questions and problems are indeed awesome. Moreover, they are an essential part of a sound education in mathematics, even at the K-12 (primary and secondary schooling) level of learning. But open-ended questions used for teaching purposes should be carefully written for sound teaching points, and teachers using them should have sufficient background in mathematics to guide student approaches to grappling with them. One of my favorite authors on mathematics education reform (Professor Hung-hsi Wu of UC Berkeley) began writing on that issue in 1994 with his article, "The Role of Open-ended Problems in Mathematics Education,"

<http://math.berkeley.edu/~wu/open-role.pdf>

and he followed up on that article with a wonderful article in the fall 1999 issue of American Educator, "Basic Skills versus Conceptual Understanding: A Bogus Dichotomy in Mathematics Education."

<http://www.aft.org/pdfs/americaneducator/fall1999/wu.pdf>

Since then, Professor Wu has written many more useful articles on mathematics education, including guides for parents, teachers, school administrators, and teacher educators on how to apply the new Common Core State Standards in mathematics better to improve mathematics education in the United States.

<http://math.berkeley.edu/~wu/>

<http://www.corestandards.org/the-standards/mathematics>

A good example of a beguiling textbook by a world-famous mathematician with lots of open-ended problems is Algebra, by the late Israel M. Gelfand and Alexander Shen.

<http://www.amazon.com/Algebra-Israel-M-Gelfand/dp/0817636773>

Some of the problems in this book are HARD, but they are generally well posed problems of actual research interest to mathematicians, that just happen to be accessible to pupils just beginning to learn algebra.

AFTER EDIT: answering the question kindly posted below, one example I had in mind is that Gelfand asks students to figure out how many different ways there are to group terms in an expression with parentheses as the number of terms increases. This essentially asks the students to discover the Catalan number sequence.

<http://www.geometer.org/mathcircles/catalan.pdf>

<comment><USER19> > Some of the problems in this book are HARD, but they are generally well > posed problems of actual research interest to mathematicians

Could you share a few examples? I've looked through the books from Gelfand's correspondence course (which are indeed excellent) but don't remember any problems that fit your description. Some of them would certainly be challenging for young children--I'm more interested in the second half of your statement.

I'll volunteer one potential example. There was a sequence of problems that dealt with the solvability by radicals of palindromic polynomials. That certainly motivates some ideas of Galois theory in no small way, but it's very basic and of no interest to research mathematicians.

Addendum: Now that I have looked it up in the book, I see it was a single problem, Problem 270, not a sequence of problems. That sequence of problems was from a mathematics competition for young children.

<comment><USER20> Parent meant problems that were in the past of interest to research mathematicians. Someone(s) published the first papers exhibiting Catalan numbers underlying various counting problems. Obviously we don't expect elementary students to be at the forefront of modern cutting edge research.

<comment><USER19> If so, that's a much weaker and not terribly interesting claim. The concrete example of counting with Catalan numbers is more compelling; it would be very challenging for children who lack experience with recursive definitions and inductive proofs. Systematic enumeration, albeit elementary, is distinctly modern.

</comment></comment></comment></comment></comment></comment><comment><USER21> Corruption in the "Text Book" industry is not new. Some of you may have read the article written by Richard Feynman about his experience reviewing math textbooks for California... in 1964.

<http://www.textbookleague.org/103feyn.htm>

</comment><comment><USER22> I've seen the horribleness of my children's text books, and completely agree that they are not-good.

But now what? Who should we be talking to who can affect change?

<comment><USER23> I don't think change in this area is going to come from within (unless the reason for change is financial). If/when it happens, I think it will be the result of external pressure that comes from things like Khan Academy and open- source textbooks proving themselves to be better than paid textbooks.

I've thought about working on a free site to help parents/students locate the best free online math resource that can help them with a specific question, worksheet, homework assignment, etc. As a tutor, I've frequently heard from parents that they know these types of things exist on the internet, but that they have no clue how to find the right Khan video that will help with tonight's homework.

If anyone is interested in this sort of thing, please get in touch.

</comment></comment><comment><USER24> My kids don't go to school, but we use the Saxon books for math here at home. They are so well put together. Incremental development. Enough consistent repetition of core concepts. All lessons back reference the fundamentals/foundations with a simple indexing system.

<comment><USER25> Do you use the original or homeschool edition? I'm planning to pick up a set soon.

<comment><USER24> I always order the homeschool set, but I believe the actual textbook is the same. We just get tests/answers.

</comment></comment></comment><comment><USER26> Left unexplained in the article is why math books need to be reinvented every year.

</comment><comment><USER27> I always find something a little ridiculous in these articles that blame the textbook for errors (or a statewide test), when the textbook has been through more review than an exercise that an individual teacher designs. That said, math textbooks are becoming an anachronism. Adaptive individualized content is already available up to high school level.

<comment><USER8> Did you even read the article? The whole point is that the textbooks are written on an impossibly tight timeline by unqualified and underpaid writers and undergo little to no review, either by the publisher or the school districts buying them.

<comment><USER27> Your comment is not related to the subtext of my comment. The guy has an editor for his textbook contributions, but no editor for the material he gives his own class. Therefore, the textbook material gets more review than something he does on his own.

To your point, if he is unqualified to write exercises for a textbook, he would also be unqualified to create these for his own class. If he is underpaid...that is largely irrelevant- if he were really underpaid, he wouldn't have taken the job.

The article was of the anti-corporate bias perspective, which is why it was on Salon.com, that this is because of the "profit motive" of the publishers. However, that perspective is also nonsensical. The examples do not change that much from edition to edition- they are seldom created from whole cloth. Even in his tortured example of complaining about the golden ratio problem was one of textbook translation- pointing out that, as an author, he cared about things other than the effectiveness of the text.

It is true that many textbooks are of low quality...but considering the bias of the writer, the whole article is a bit self-serving, while also being hypocritical.

All points about the incompetence of textbook buyers stand though. They choose for the worst of reasons, with effectiveness almost never even on the table as a concept.

</comment></comment></comment><comment><USER28> On the commission thing. one thing that's easy to overlook is that once an author has written the book, there's nothing more to do, in an ongoing day-to- day sense. Sit back and enjoy the royalties for years. Someone else does the selling, and the author's efforts don't scale with the number of sales. The salesperson has to sink effort into each sale, has to work it, or at the very least do the paperwork.

Similarly the author gets royalties on all copies, but the salesperson only gets commission on the books they sell. A thousand books sold by four sales staff is 1000 books for royalty purposes, but only 250 books on average for commission purposes.

There is some slight irony in assuming something is wrong with the number just because they don't appear superficially linearly correct, when criticising the quality of maths books...

<comment><USER29> _Sit back and enjoy the royalties for years._

Apparently, that's not the case anymore for educational book writers. The article states:

 _Today, royalties are a thing of the past for most writers and work-for-hire is the norm._

...and during the article this new state of affairs is mentioned quite a few times, and loathed.

</comment></comment><comment><USER30> One might thought that people incremental revise previous editions rather than publishing whole new content, but it doesn't seem to be the case. At that point, we might as well just use khanacademy math lecture and show them according to a teacher's lesson plan.

<comment><USER2> In most states math education is completely fad driven.

Textbook selection committees are usually staffed with people who do not understand the subject, and when domain experts are asked to donate their time to evaluate materials, their feedback is ignored as the only purpose of having them aboard was to apply to the dog and pony show evaluation proceedings a sheen of legitimacy.

Textbook publishers spend millions each year wining and dining members of committees, providing them with gifts and trips and sometimes even setting them up with speaking fees that are a masked form of bribery and kickbacks. It's a well known problem and has been going on for decades. It's very similar to the way the pharmaceutical rep industry works.

I strongly recommend everyone read "Judging Books by Their Covers" by Richard Feynman for his experience in the process, which remains the standard modus operandi to this day:

<http://www.textbookleague.org/103feyn.htm>

As the editor's postscript to that article summarizes:

"As a rule, however, state agencies don't want legitimate evaluations of the textbooks that publishers submit for adoption, because the agencies are allied with the publishers. The adoption proceedings staged by these agencies are not designed to help school districts, to protect students, or to serve the interests of taxpayers. Rather, they are designed to serve the interests of the publishers, to generate approvals and certifications for the publishers' books, and to help the publishers sell those books to local schools."

These dynamics are part of why I strongly oppose calls for national standardization, the streamlining and centralization of would lead to a much larger and more difficult to combat corruption as greasy palm edu-bureaucrats rake in the dough for selling out the country.

<comment><USER31> Fad driven, or politics/corruption driven? The textbook "industry" is one of the most pernicious, that really should be put out of business... in today's world, even if we were doing dead-tree based knowledge devices, they could be tailored to the individual and printed on demand.

Of course, things like tablet-based (eInk or LCD) reading and khan academy are the future of learning.

<comment><USER2> There's two separate phenomenon. Pedagogical approaches follow fads rather than solid principles known to work. Textbook selection is corrupt. Both are problems that have not been solved at least since Feynman's experience in the 1960s despite much effort and an awareness of the problem.

</comment></comment></comment></comment><comment><USER32> This guy knows a lot about the textbook industry, but I'm not sure he knows much about teaching and learning.

How you design texts can make a difference (google "conceptual change texts" for example), but how much do textbooks really influence the quality of instruction? If a teacher is just blindly following a textbook (and not doing other things like supporting students, using interactive software, etc.), then there are bigger problems.

Ironically, too, students would learn _more_ from a textbook with mistakes in it if they were made aware of that fact and encouraged to find them. I know I learned the most in geometry where I had a teacher who couldn't even draw a circle and made mistakes every single day.

</comment><comment><USER33> How much has grade school level math changed over the years? Do we really need new textbooks?</comment>


EFF to Copyright Office: Safe Harbors Work - <AUTHOR> https://www.eff.org/deeplinks/2017/02/eff-copyright-office-safe-harbors-work <comment><USER2> Not quite to the point, but I learned recently (probably from BBC's program Click) that in Cuba, while there's more access to the internet now, it's non- net-intermediated piracy that's a huge thing in that very information enforcement-minded state. Massive libraries circulate from hand to hand. That's really the larger threat to copyright holders in the long run, it seems to me. To exaggerate what's now possible, if people can swap USBs with the contents of the library of congress or every song in the Billboard top 100 for the last decade, then you have a whole different order of difficulty for enforcement. A difficulty that I think was behind the (then shocking) decision long ago to legally allow people to record songs from the radio onto tape recorders for later listening. Preventing it was all but impossible, and it's clearly not advisable to pass laws that many or most people will violate as a matter of course.

Close off one method, and another very good method steps up to the plate.</comment>


Ask HN: Host multiple flask and django apps on single server - <AUTHOR>

What would be the best way to host multiple flask and django apps on a single server? From reading around it seems to better to use nginx and/or gunicorn, but I can't decide between nginx alone OR nginx + gunicorn. Should I consider Tornado? I don't really plan to have real-time stuff in my apps.<p>I'm using an EC2 micro instance (Ubuntu Precise) <comment><USER2> In my experience using nginx + gunicorn will help here is why: gunicorn create child processes for your server. This way you can have 3-4 process all working towards serving your web-application. Nginx helps for serving static files and reverse poxing to either flask / django process. You should also consider using something like supervisord. Supervisord will make sure you're processes are restarted if they crash for some reason.

<comment><AUTHOR> Thanks, iamsidd2k7. That was helpful.

</comment></comment><comment><USER3> I have more experience with Nginx + Gunicorn, but I can tell you that it's pretty painless. "manage.py run_gunicorn" to get started, and you can assign it an arbitrary port and number of worker nodes depending on how many users you expect. Supervisor will obviously be needed to keep it up and running, but I've got dev instances that are fairly heavily trafficked I'm not running supervisor with, and I've yet to see Gunicorn crash, where I used to see Flup crash constantly.

In addition to what's already been mentioned, you'll definitely want to be using virtualenv for portability. Being able to maintain different libraries for different apps is essential, and virtualenv does a great job of keeping things isolated.

<comment><AUTHOR> Thanks, bmelton. Decided to go with nginx + gunicorn. Was a little hesitant to use virtualenv, will go ahead and use it based on your recommendation. Thanks again! :)

<comment><USER3> It took me awhile to get used to it, but there's really no reason not to use virtualenv.

The more you use it, the more you have to use it. I had two projects with different authentication mechanisms that were unfortunately named the same thing. I accidentally deployed one without virtualenv and spent the next whole day figuring out what happened.

Virtualenv is a life-saver, and it's so easy to do that you might as well just always do it everywhere.

<comment><AUTHOR> Just hit a similar situation at work and realised why I had to use it. Had a django app called taxonomy in a project, couldn't use the same name in another django project. Now I definitely have to use it!</comment></comment></comment></comment>


How a Kalman filter works, in pictures - <AUTHOR> https://www.bzarg.com/p/how-a-kalman-filter-works-in-pictures/ <comment><USER2> The use of color to impart additional semantics in mathematical equations, at least to this degree, is not something I have considered before.

This is going to change a lot in how I communicate with math.

<comment><USER3> Kind of like Stuart Riffle's colorized Fourier Transform. (version here -> [https://blog.revolutionanalytics.com/2014/01/the-fourier- tra...](https://blog.revolutionanalytics.com/2014/01/the-fourier-transform- explained-in-one-sentence.html))

archived with artifacts here -> [https://web.archive.org/web/20120418231513/http://www.altdev...](https://web.archive.org/web/20120418231513/http://www.altdevblogaday.com/2011/05/17/understanding- the-fourier-transform/)

</comment></comment><comment><USER4> I built a smart volume control system out of distributed Kalman filters + classic PID control to track the EBU-128 loudness envelope of an unknown sound source and attenuate the music gain to keep it at a comfortable level: [https://wallfly.webflow.io/](https://wallfly.webflow.io/)

The challenge comes when dealing with silence, or breaks in a song: if you detect silence, should the volume go up or down? Of course, the dynamics make the music and should not change, but you don't know that without access to the source signal. So you add latency to the PID controller, but then you get overshoot (classic time/accuracy trade-off).

To do perfect control you need access to the source signal, or lookahead, but you can still do a pretty good job without the source signal by capping the signal gain, i.e. only attenuate and never add amplify. Still compresses the signal, though.

There are some clever tricks used in radar systems that you can use to estimate the noise in a room, like coherence: [https://en.wikipedia.org/wiki/Coherence_(signal_processing)](https://en.wikipedia.org/wiki/Coherence_\(signal_processing\)).

In an LTI (linear time-invariant system), coherence can compare the acceleration of both input and output signals to calculate the power (but not the contents) of external signals that entered the system.

Coherence, is in my opinion, underused in industry.

</comment><comment><USER5> When implementing Kalman filters a common issue is that the covariance matrix P retards to be not positive semi-definite due to numerical errors. When this happens the Kalman filter may result REALLY weird results.

There is an easy fix for this that is rarely mentioned, except one runs into this issue and googles it: After updating (prediction and observation) P just ensure its positive semi-definiteness by averaging with its transpose:

P := (P+transpose(P))/2

<comment><USER6> What you have recommended will tend to stabilize the covariance matrix, but not for the reason you have given. If numerical stability is an issue you encounter, I would caution against using it. Try [1] instead.

You imply that any symmetric matrix is positive semi-definite. Take an orthogonal matrix U and a diagonal matrix D with one or more negative values.

P = U * D * U.T is symmetric but not positive semi-definite.

For example, if D[0,0] = -1 then U[:, 0].T * P * U[:,0] = -1.

[1] [https://en.wikipedia.org/wiki/Kalman_filter#Square_root_form](https://en.wikipedia.org/wiki/Kalman_filter#Square_root_form)

</comment></comment><comment><USER7> I recommend this article frequently when someone is looking to learn about Kalman filters. It's got some nice I intuition building descriptions. I also like [https://github.com/rlabbe/Kalman-and-Bayesian-Filters-in- Pyt...](https://github.com/rlabbe/Kalman-and-Bayesian-Filters-in-Python)

</comment><comment><USER8> The latest innovative mainstream use of a Kalman filter that I'm aware of is from a Microsoft contribution to chromium, for better tracking the mouse: [https://chromium- review.googlesource.com/c/chromium/src/+/18...](https://chromium- review.googlesource.com/c/chromium/src/+/1822657)

</comment><comment><USER9> Nice, I wrote an article too that helps develop an intuition without much math

[https://aguaviva.github.io/KalmanFilter/KalmanFilter.html](https://aguaviva.github.io/KalmanFilter/KalmanFilter.html)

<comment><USER10> > What if we can only carry one sensor?

> That is what happened exactly in the Apollo rocket, back in the 60s the IMUs > were veeery heavy and they could only carry one.

The first and most famous application of a Kalman filter in the Apollo program was for the problem of midcourse navigation. In this application, the Apollo PGNCS used the Kalman filter to combine the calculated trajectory based on vehicle dynamics with the sextant measurements (optical starsighting). The IMU was not used for midcourse navigation.

See e.g. Figures 1-6 and 5-5 in [http://klabs.org/history/history_docs/mit_docs/1697.pdf](http://klabs.org/history/history_docs/mit_docs/1697.pdf).

</comment></comment><comment><USER11> If you want to learn Kalman Filter in depth then I can recommend the open source interactive book Kalman and Bayesian Filters in Python [https://github.com/rlabbe/Kalman-and-Bayesian-Filters-in- Pyt...](https://github.com/rlabbe/Kalman-and-Bayesian-Filters-in-Python)

</comment><comment><USER12> When I used to develop Kalman filters, visualizing the covariances was the best way to understand/debug the setup. Two great libraries that I used were eigen3 (for the filter) and point cloud library ([https://pointclouds.org/](https://pointclouds.org/)) for visuals.

</comment><comment><USER13> Yes, and I love the pictures, but I wish they had a key attached, with the simple English name of each variable in the equation, because it's no fun to hunt around a long article for the definition of a one letter variable. Common problem on Arxiv

</comment><comment><USER14> See my recent submission on particle filters for an alternative to Kalman filters: [https://news.ycombinator.com/item?id=23948245](https://news.ycombinator.com/item?id=23948245)

</comment><comment><USER15> One thing the textbooks and explainers never seem to think to do is start with the one-dimensional case. All the confronting looking matrix equations reduce to an intuitive, even obvious set of arithmetic operations.

<comment><USER16> Indeed. The simplest one-dimensional case of the Kalman filter is just exponential smoothing, which you can implement and tweak in a spreadsheet. Unfortunately the leap to the general multivariate case is still pretty big.

</comment></comment><comment><USER17> I enjoy these sorts of articles, but man no matter how many times I read one the mathematical equations just look like hieroglyphics to me

<comment><USER18> Equation reading speed should be _much_ slower than explication reading speed, which is in turn normally slower than prose reading speed.

(Compare with reading music: one can derive value from passages embedded in text without being able to sight-read, but one ought to make the effort to play them nevertheless.)

</comment></comment><comment><USER19> This video series helped me finally understand how to use Kalman Filters. [https://www.youtube.com/watch?v=CaCcOwJPytQ](https://www.youtube.com/watch?v=CaCcOwJPytQ)

</comment><comment><USER20> Great article. I've been trying to grok the Kalman filter for a while now, definitely seems to have clicked a little more this time. BTW if the author sees this the link at the bottom 'Some credit and referral should be given to...' seems to be broken.

</comment><comment><USER21> (2015)</comment>


@twitterapi's countdown to Basic Auth removal - <AUTHOR> http://www.countdowntooauth.com/ <comment><USER2> I think it's a huge mistake. Mainly because when I write some random application (bot or something) I really don't want to mess with oauth when I just want to send a tweet. Plain.

Please, twitter. Don't.

<comment><USER3> This comment sounds really assholish. I apologize in advance.

This is why libraries exist. You shouldn't be implementing OAuth yourself.

<comment><USER4> What does your one-liner OAuth implementation for wget in bash look like?

Because that's what it's competing with, with Basic Authentication. A simple POST to statuses/update.xml with HTTP username and password, a wget one-liner.

<comment><USER3> I just said it was easy, not that it'd be one line. But most of the libraries I've seen are pretty simple, see the oauth gem: <http://oauth.rubyforge.org/>

Three or four lines. Not the end of the world.

I agree that it's not as easy and simple as HTTP Authentication, but it's much nicer from a user's standpoint.

</comment></comment></comment></comment><comment><USER5> Edit: OK, I was wrong, as I'd hoped - you don't need a web browser. The rest of my post stands unchanged as, regardless of my interpretation, it kills the Twitter support I just wrote in less than an hour into one of my apps, and renders it a multi-hour (if not day) redevelopment. I'll probably just kill the feature.

This seems like a silly move: What was previously a very easy to target platform is now much less easy. Was there a glut of user credential theft from the basic authentication API that's caused this? Or is it the architectural purists winning out over engineering pragmatism?

I'm not convinced that, on most devices, it will actually add any security anyway. Consider iPhone application "EvilTwitter". User enables Twitter support. I, evil developer, present a fake Twitter OAuth page. This looks identical to the Twitter login page, carefully configured to hide most of the Safari interface (as 99% of iPhone Safari embedders do). The user enters their details, I steal them, the present a "Woops, wrong password" error. I redirect them to the _real_ OAuth verification page. From here on, my application works fine - the user just assumes they mistyped their details the first time (as mobile device users do, well, continuously).

<comment><USER6> Subscribe to the Twitter developer lists. They have solutions for platforms without a browser.

<comment><USER5> OK, having researched, I presume you're refering to the XAuth stuff <http://dev.twitter.com/pages/auth#browser-less-apps>.

How the frell is this any better than Basic auth for most users? I can only see that 1) I don't have to store their password on my client and 2) it won't be sent across the network plaintext.

This is useless. End users have no idea that I'm actually doing 1), and 2) has never been a problem (HTTPS supports Basic auth fine for transport encryption).

</comment></comment></comment><comment><USER7> I've actually gone and removed Twitter support from an application I work on. It was a small, fun /tweet command in Mobile Colloquy. I wrote it on a whim; it came out to maybe 100 LOC (with proper error handling and formatting). More time spent in NSURL{Connection, Request}'s docs than on anything else.

It was removed because it isn't worth the hassle of adding in an {O, X, YetAnotherCharacter}Auth library. No, I don't have to write the code for it. No, including _an entire library_ is not better than _100 lines of code_ (where the the authentication part amounts to one line if there isn't any error handling).

Twitter's API went from being incredibly nice and easy to work with to having a huge barrier in front of it as soon as they deprecated basic auth.

//edit: Note: I'm not trying to condemn OAuth. I'm sure it has its uses (even if I'm not quite sure what they are). I just don't see how it is a benefit in this particular case.

</comment><comment><USER8> My twitter client app uses Basic Auth yet doesn't store username or password, it's all kept on client side. I won't be rewriting so it'll now be useless.</comment>


Joyent and Samsung: Thoughts after the close - <AUTHOR> https://www.joyent.com/blog/joyent-and-samsung-thoughts-after-the-close <comment><USER2> I'm in the "Congratulations, I hope?" camp. Acquisitions by big companies rarely work out.

One of my favorite quips was about Intel acquiring McAfee: _JPMorgan analyst Christopher Danely upgraded Intel to overweight following the company 's earnings, although he still struggles to reconcile Intel's recent acquisition spree.

"Intel might as well have bought Whole Foods," he said of the McAfee deal._

And, recently, we've seen a lot of press about how Intel is thinking about dumping their Cyber Security division, nee McAfee.

Then there's the apocryphal quip about Ballmer and RIM: _Technology industry rumours suggest a Microsoft takeover of RIM, considered an excellent match in competence and vision. "Synergy's just another word for two and two makes one!" said Steve Ballmer. "We will assimilate your technological stench of death into our own."_

Microsoft didn't buy RIM, but I don't think anyone will argue that the similar thing they did do, i.e. buy the Nokia phone division, worked out for them.</comment>


Java is Pass-by-Value, Dammit - <AUTHOR> http://javadude.com/articles/passbyvalue.htm

<comment><USER2> Good post.... I am a Java developer with almost 10 yrs of experience and I know I often make that mistake even on Job interviews:).... The problem is that people used to Java tend to think more about the intuitive consequence of passing by ref vs value. When a Java dev thinks of passing by reference he's thinking: "I can alter the state of the reference and the changes would be visible globally, including from within the calling context". In other words Java devs think about altering arguments in terms of altering their state as opposed to altering the reference which is just a numeric address to a memory location. People who program in languages lacking object/class-like structures are more aware of the need to use parameters both as arguments and return values, something that is foreigner to Java programmers.

I haven't done any serious C++ programming in years and I have to admit the examples you used to demonstrate your point; ie modifying the value of arguments appears very strange to me now, I obviously did a lot of that when I did C/C++ development but not having done it in such a long time it really does seem like an unusually way of getting return values:)

</comment><comment><USER3> Almost EVERYONE I've interviewed, including senior programmers, think that if you do this:

       void nullThis(Object o) {
          o = null;
       }
       Object o = new Object;
       nullThis(o);
       System.out.println(o.toString());

throws a NPE

</comment><comment><USER4> Java is in good company. Lisp is also pass by value.

</comment><comment><USER5> Passing an object by reference is the same thing as passing an object reference by value. It _is_ just semantics. Its not even splitting hairs. Its demanding that his specific definitions are somehow more correct than any other.

<comment><USER6> This is not at all correct because passing by reference and value have defined and distinct meanings. Consider the difference between C++, which has actual pass by reference: void swap(int& x, int& y) { int t = x; x = y; y = t; }, and Java: void swap(Integer x, Integer y) { Integer t = x, x = y; y = t; }. The C++ version will result in changes to the variables in the calling function and the Java version will not.

The real problem is that Java created needless confusion by calling its pointers references for purely marketing reasons.

<comment><USER5> No the real problem is that you fail to understand that Java gets to call these things what ever it likes because language has context. And your example fails to compare apples to apples. In Java Integer _is_ an object, but int is not. You are confusing Java things with C++ things. As you can see, Java is not C++, and so your C++ terms and definitions do not apply here. Thank you for playing. Move along.

<comment><USER6> "No the real problem is that you fail to understand that Java gets to call these things what ever it likes because language has context."

This is silly; "pointer" and "reference" both had meanings before Java came along. If Java called pointers "names" instead of "references" it wouldn't mean that its function call semantics were pass-by-name either. And besides; if your argument is that we should use the Java terminology to describe all the aspects of Java under discussion, the fact that the all the Java designers make explicit that the function call semantics pass references as values, not objects as values.

"And your example fails to compare apples to apples. In Java Integer is an object, but int is not. You are confusing Java things with C++ things."

The argument applies if you use int in place of Integer just the same; or if you make a C++ Integer wrapper class analogous to the Java one. Any comparison here will of course be apples to oranges because _C++ supports pass by reference and Java does not_. The swap function is impossible to write in Java because it requires allowing called functions to change the values viewed in the caller, which is almost the definition of passing arguments by value.

"As you can see, Java is not C++, and so your C++ terms and definitions do not apply here. Thank you for playing. Move along."

Leaving aside the childish and insulting tone, the definition of "pass by reference" has nothing to do with C++; if the code were in perl it would still be pass by reference, because "pass by reference" has a meaning that exists outside of any particular programming language and describes a concept. Java function calls are not part of that concept; "there is exactly one parameter passing mode in Java - pass by value".

<comment><USER5> In which case there is no such thing as passing by reference. Ever. In C++ when you "pass by reference", what actually happens is that the address of the thing is taken, and a pointer is generated, and then that pointer is passed by value. Do you see? Any argument you put forth to the contrary will involve language specific features and conventions of C++. Your will have to claim that because the C++ compiler does this for you, that makes it special. In Java there are primitives and objects. Primitives are only passed by value. Objects are passed by reference. If you pass an object as a parameter, and then modify a property of the parameter, then it is the original object that is modified. This, in fact, is the same as when you pass an Object in C++ by reference. In contrast, in C++ you can also pass an object by value: the entire object is copied onto the stack.

class Foo; void modify( Foo& x) { x.setBar(1);} ; <\- pass by reference in C++.

class Foo; void modify( Foo x) { x.setBar(1);} ; <\- pass by reference in Java.

Java spares you the & because Java _only_ passes by reference.

Again, to argue the contrary, simply because it passes an object pointer by value, automatically, is to argue that C++ never passes by reference because it too takes the address automatically.

The fact is that Java passes by reference exactly as C++ does. However, even if this were not the case, it would also be completely acceptable for Java to refer to what it does as pass by reference simply because it chooses too. These things _are_ object references. If I pass a java object reference, is it acceptable to say I'm passing by reference? If Java people want to say it is, then it is. Will the world end, for example, because the word "heap" means two different things in computer science? <http://en.wikipedia.org/wiki/Heap> OMG! Who is _right_?

My point is basically summed up here: <http://xkcd.com/435/>

You are where the physicist is standing. You insist that Java biologists are using your terms wrong while oblivious to the mathematician. You have your abstractions. Java has theirs.

Of course, maybe you're the chemist, and I'm the physicist (I still write assembly) and the hardware guys are the mathematicians. Whatever.

As for the insulting tone, yes its a character flaw. When someone makes a statement like "I'm really tired of hearing folks (incorrectly) state [whatever]", its insulting. Its especially insulting when its wrong. In an ideal world I'd be able to respond without resorting to responding in kind, but I'm flawed. Sorry. You're still wrong.

<comment><USER6> The argument "well, passing by reference gets compiled to passing a pointer by value so really there is no passing by reference" is silly because passing by reference is a description of language semantics and function call evaluation. Your argument applies just as well to the statements "there is no such thing as lambda functions" or "there is no such thing as garbage collection" because those language features also get converted into representations that don't have either of them present.

The Java code you give isn't an example of passing by reference because, while you can change the value that x points to in Java, you can't change x to point to something different. No java function can change its arguments; the example you gave has the java function changing something that its argument points to.

Your argument that Java people can call language features the same name as distinct language features is: a. dumb, because it's just "words mean whatever anyone wants them to mean", and b. doesn't come anywhere close to applying here; the quotation at the end of my last response: "there is exactly one parameter passing mode in Java - pass by value" is a direct quote from 'The Java Programming Language'. _The authors of Java disagree with you_.

More from them: "All parameters to methods are passed 'by value'. In other words, values of parameter variables in a method are copies of the values the invoker specified as arguments. If you pass a double to a method, its parameter is a copy of whatever value was being passed as an argument, and the method can change its parameter's value without affecting values in the code that invoked the method.

...

You should note that when the parameter is an object reference, it is the object reference - not the object itself - that is passed "by value." Thus, you can change which object a parameter refers to inside the method without affecting the reference that was passed. But if you change any fields of the object or invoke methods that change the object's state, the object is changed for every part of the program that holds a reference to it.

...

Some people will say incorrectly that objects are passed "by reference." In programming language design, the term pass by reference properly means that when an argument is passed to a function, the invoked function gets a reference to the original value, not a copy of its value. If the function modifies its parameter, the value in the calling code will be changed because the argument and parameter use the same slot in memory.

...

The Java programming language does not pass objects by reference; it passes object references by value. Because two copies of the same reference refer to the same actual object, changes made through one reference variable are visible through the other. There is exactly one parameter passing mode - pass- by-value - and that helps keep things simple."

Your last few paragraphs are beside the point; the question is not about which languages offer which levels of abstraction; the point is that different abstractions have different names and Java doesn't offer the abstraction named "pass by reference".

<comment><USER5> Perhaps I misunderstand the whole thing then. Tell me is this C++ code "pass by reference" or not?

class Foo;

void Bar( Foo& somefoo) { ... }</comment></comment></comment></comment></comment></comment></comment>


Two special startup types: the Twitter and the Hoverboard - <AUTHOR> http://www.danshapiro.com/blog/2011/07/a-twitter-a-hoverboard-or-something-in-between/

<comment><USER2> I sense that we could construct an amusing zoo of subcategories here.

e.g.

The Oyster: A species of Hoverboard that appears to magically parse natural language or generic web data but which on close inspection turns out to be a slick-looking wrapper around a rat's nest of Perl regular expressions which are being frantically updated by a harried group of hackers to deal with each "edge case" as it arises.

The Turk: Like an Oyster, but without the regular expressions.

The Esperanto: A Hoverboard that promises to help non-programmers write programs by using "natural" syntax that is "just like human language". See e.g.: AppleScript.

The Gift-Horse Engine: A Twitter that is in fact virally popular, but only because it bribes adopters by giving away something below cost in an unsustainable way.

</comment><comment><USER3> AirBnB in my opinion is no longer a "Twitter Startup." Maybe at first, but now they've proven people will sacrifice some level of comfort to save money, which in my opinion took a lot of gumption. This now proven disruptive model (sacrificing some comfort/certainty/social norms to save money) I think is only beginning.

<comment><USER2> I think this article isn't describing startups so much as startup _ideas_ , and/or very early startups that have yet to demonstrate the elusive product/market fit. Once you've proven that your Hoverboard works, and that it really is a Hoverboard ("an idea that, if it works, will practically sell itself") then it isn't really a Hoverboard anymore. And once your Twitter concept has users and a viable business model it isn't a Twitter anymore.

Ironically, AirBNB is no longer a Twitter startup, but Twitter arguably still is. ;)

<comment><USER3> Good point, although I'd argue Twitter has shown its product/market fit (political strife/breaking news/Bieber).. Also, I agree, my comment is off topic, but I'm a bit tired of poor little AirBnB (now valued at $1 billion) not getting credit for sticking their noses in and bravely creating a new market.. PG might agree w/ me <http://www.paulgraham.com/airbnb.html>

</comment></comment></comment><comment><USER4> I like the part where he says "if you aren't one of these types, keep calm and carry on."

A lot of articles seem to try and classify all startups into 2 or 3 types which is honestly pretty silly.

</comment><comment><USER5> This is a neat, memorable way of explaining what Steve Blank calls [Customer/Market Risk versus Invention Risk]([http://steveblank.com/2009/05/28/vertical- markets-2-customer...](http://steveblank.com/2009/05/28/vertical- markets-2-customermarket-risk-versus-invention-risk/))

</comment><comment><USER6> Here is Ali G pitching a hoverboard to a VC.. great stuff: <http://www.youtube.com/watch?v=nkuOuxRD1Bc> \- go to 5:20 on the video.

      Ali G: "Its a hoverboard" (holding a skateboard with no wheels)
      Investor: ".. but it doesn't do that"
      Ali G: "Well, it doesn't do it yet.  Thats where you come in - with your science"

<comment><USER7> He's a non-science founder ;)

</comment></comment><comment><USER8> _it's not going to be very hard to solve the problem technically (you'd be wrong, of course, but that's besides the point)_

Actually, I would say that the problems twitter is solving _aren't_ terribly difficult. Now, doing it at such a massive scale is very difficult. But I think a large portion of twitter's success is that their solution seems rather easy to implement at small scale.

<comment><USER9> Agreed. Twitter-like apps seem to be the go to first project for learning a new language for web development.</comment></comment>


Ask HN: TechCrunch Ads - <AUTHOR>

Did TC remove all their ads? Why? <comment><USER2> Nope. Opened it in IE and there is a big banner ad right at the top next to the TC logo advertising "environment defense" with an "Ad Council" logo to the left of that

And it links to something through doubleclick.

And there is another ad below the header (for me, right now, it is for www.makemytrip.com)

<comment><AUTHOR> Thanks!</comment></comment>


What's up with the whois spam for google.com? - <AUTHOR> http://www.123-reg.co.uk/full_whois.cgi?domain=google.com

<comment><USER2> This is old news, microsoft.com had the same crap for years.

<comment><USER3> And Amazon, and Yahoo, and other popular domains. The problem is that InterNic should not sit and quietly accept this kind of abuse.

<comment><USER2> Honestly, any regulatory scheme over subdomains would be even worse than this "abuse".

<comment><USER3> Subdomains are not the problem. The issue is that these are registered namesevers, as pointed out by "there" below.

</comment></comment></comment></comment><comment><USER4> Often used for phishing. "Login to your account: <http://google.com.adsfjk.asdf.asdfpuiasdf/soasdf.html> blah blah."

<comment><USER5> hardly. these are registered nameservers showing in whois and have nothing to do with random subdomains.</comment></comment>


OS X Lion and its implications for web design - <AUTHOR> http://blog.andycroll.com/2011/06/07/os-x-lion-and-web-design/

<comment><USER2> Full screen apps? Seriously? Maybe they made sense on a 15" screen, but when I have dual or triple 20" monitors, I'd want to punch any developer that wants their app to run in fullscreen.

I don't like the trend I'm seeing.

<comment><USER3> What I'd like to see is a tiling window manager to go along with the full screen apps. I love XMonad on Linux, but some apps just don't work very well. Maybe if applications are written to be full screen they'll work well tiled.

<comment><USER4> I agree. Note that there are multiple things on the Mac App Store that do this already; for instance, I dug up TileWindows (never tried it, no idea if it's the best of them).

It would be nice if windows could be independently told to lose their chrome to make more room, as they seem to in Full Screen, but without actually taking up the whole screen in the process. For instance, why shouldn't I be able to toss 2 or 3 terminal windows on the left half of a display while still having room for regular, non-Full-Screen windows on the right?

Ultimately I think Apple made a good decision by combining Full Screen and Spaces, because they are _very_ similar. Each screenful is essentially devoted to some task, whether that task requires many windows or one, and it's nice to switch between them so easily.

The only question that remains for me is what will happen with 2 displays. I _hope_ Apple has a simple way to place any Full Screen app and/or any Space on _either_ display, where I can switch one display without affecting the other. One of the infuriating things about Mac OS X 10.6 and earlier right now is that a full-screen app on a second display affects the first display in weird ways (e.g. a 2nd display's full-screen mode can be turned off by trying to interact with windows on the 1st display, which seems like a nonsensical restriction).

</comment></comment></comment><comment><USER5> I agree with designing for mobile first, makes for a less cluttered UI

</comment><comment><USER6> Will some people expect some browser chrome? Will some website designers put a back/forward/refresh button on fixed at the top of the screen?

<comment><USER7> Let us pray that this does not happen.

There is the basic chrome on the fullscreen views (back, address bar etc.) just not so much of the window chrome. ChromeOS-like if you will.</comment></comment>


Winamp's woes: How the greatest MP3 player undid itself (2012) - <AUTHOR> https://arstechnica.com/business/2017/07/winamp-how-greatest-mp3-player-undid-itself/ <comment><USER2> I still use it every day!

Of course this means most of my music is pirated (I tend to buy a physical album and then download a well-ripped or digital copy) but I've found it hard to move to other ways of managing my music.

My own way of organizing and collecting makes sense to me and pretty much no one else, but that's fine since hardly anyone else ever wants to use my computer to play music. I'll use Winamp until it is no longer possible to run on Windows, probably.

<comment><USER3> While I've surely "pirated" plenty of audio files in my day, I wouldn't say the majority of mine are like that. Most are ripped from the hundreds (no exaggeration) of CDs I bought new and used all through high school and college or purchased from Amazon, etc.

Still, pirated or not, I like having a space on my NAS for my traditional Music/Artist/Album/[track]_[title].mp3 folder structure. Pointing Winamp at it works fine for the majority of my listening at home.

Of course I've come a long way from running an unlicensed Shoutcast station in the early 2000's (it was nice having a friend who worked at a small hosting company who gave me the space to host the server and all the bandwidth I could need to stream to my massive audience of maybe 5 or 6 people at once ;)) but I still love listening to streaming "radio" in the car without any need for subscriptions or any hardware other than my phone. I've been doing it since I had a Palm Treo, but the move from a max data rate of ~256k/sec to LTE has certainly helped.

Only thing I really miss these days in Winamp is a way to cast to Chromecast/Chromecast audio in other parts of the house. Not sure if anyone's hacked together a plugin but I haven't really looked.

<comment><USER4> > for my traditional Music/Artist/Album/[track]_[title].mp3

For anyone wondering what a good tool to organise your music like this is, for example if you use Winamp or something like MOC, it's a Python tool called "beets"[0] which will rename (or copy, if you choose) your files to a directory structure you specify. It will also talk to Musicbrainz to fill in missing metadata, and has plugins to fetch album art.

[0] [http://beets.io/](http://beets.io/)

</comment></comment></comment><comment><USER5> Foobar is a better player today, but Winamp was so much fun till 2.xx. They had colour and great interfaces. They were the rock stars at the time of boring sotware UI. Then Winamp 3 and then 5, and AOL and UuUUUgghhhgh!

Nullsoft made some neat software, like NSIS... [http://www.1014.org/code/nullsoft/nbeep/](http://www.1014.org/code/nullsoft/nbeep/) [http://www.1014.org/code/nullsoft/nscopy/](http://www.1014.org/code/nullsoft/nscopy/)

Does anyone remember Sonique?

<comment><USER6> I used Sonique for a bit but I went back to Winamp because Sonique was too sluggish on my PII233/64MB/3GB laptop.

</comment></comment><comment><USER7> "When you think about what AOL had in early 2000," he told Ars, "the only thing that they were missing that [would be] essential to today's media system is a hardware device. They had the number one software for playing [in Winamp], and in theory, although not in practice, the [Time Warner] content library that could have been a pioneer in streaming. And a radio service. It had all the elements. AOL could have been Spotify, it could have been Pandora."

Winamp was one of my favorite programs. It was really fast, took very little memory and was really easy to use.

</comment><comment><USER8> Fun fact: the catchphrase "Winamp! It really whips the llama's ass!" was inspired by Wesley Willis.

<comment><USER9> RIP. A true visionary in the vocal vamp arena and a gem of Chicago's North Side sidewalk synthesizer music scene.

</comment></comment><comment><USER10> Don't let the byline fool you, this is a rerun from [2012].

</comment><comment><USER11> Winamp was the only app that kept working after windows crashed:)

</comment><comment><USER12> On the Mac, if you long for a Winamp-style player, try Vox.

</comment><comment><USER13> It's simple. They sold themselves to AOL.

</comment><comment><USER14> Can't people just move on and use AIMP?

<comment><USER15> Or xmplay. From the guys who made BASS

</comment></comment><comment><USER16> What's going on at Ars Technica? Between this (a straight-up repeat from 2012 with no obvious reason to bring it back now), and reblogging Jimmy Maher's Digital Antiquarian articles from the same time frame (see [https://arstechnica.com/gadgets/2017/06/ibm-pc-history- part-...](https://arstechnica.com/gadgets/2017/06/ibm-pc-history-part-1/) and [http://www.filfre.net/2012/05/the-ibm-pc- part-1/](http://www.filfre.net/2012/05/the-ibm-pc-part-1/)), have they cut their budget for new writing?

<comment><USER17> Their comment section since last year has devolved into Reddit style one- liners (especially political articles). The articles are really average these days.

The one I'm really worried about is Anandtech, the articles are still excellent but they're so understaffed(A10 chip deep dive was canceled, behind on Mac reviews)

<comment><USER18> Yes. Ars Technica has changed. I do find their articles are not as good as they used to be. Although, articles from Peter Bright and Kyle Orland are still high quality.

I like their occasional (weekly?) articles on board games. I do not like their movies/series articles that much. Mixed bag on their Cars Technica stuff. However, I find there's too many articles which are only tangentially related to tech or science. Example: the story of the woman that shot her boyfriend while recording a video for their Youtube channel.

Your observation about their comment section is spot on. Comments beyond page 1 are buried.

</comment></comment></comment><comment><USER19> So basically, a corporation bought a company they had no idea how to run, ran it into the ground pursuing monetization that worked elsewhere (kind of). This sounds like every acquisition between 97 and 05.

I wonder how many great products were destroyed by the big corporations attempting to fit a square peg in a round hole, and failing every time?

</comment><comment><USER20> As soon as I became aware of Foobar2000 WinAmp dropped off the radar completely for me.</comment>


Show HN: a Hacker News app that runs on RaspberryPi+S3 - <AUTHOR> http://www.fullhn.com

<comment><AUTHOR> A few notes on building Full Hacker News here: [http://svay.com/blog/building- full-hacker-news/](http://svay.com/blog/building-full-hacker-news/)</comment>


Top 20 post on Hacker News - The stats - <AUTHOR> http://christeso.com/top-20-post-on-hacker-news-the-stats

<comment><USER2> Interesting to see how 50% are using Chrome. I guess firefox is no longer the geek's browser it used to be.

</comment><comment><USER3> A useful data point, thanks for sharing!

<comment><AUTHOR> welcome.</comment></comment>


Umash: A fast and universal enough hash - <AUTHOR> https://engineering.backtrace.io/2020-08-24-umash-fast-enough-almost-universal-fingerprinting/ <comment><USER2> > BLAKE3 needs at least 100 ns to hash short inputs, and achieves a peak > throughput of 1.3 GB/s.

I haven't run benchmarks on the Intel 8175M myself, but I would expect single block execution time closer to 60 ns and peak throughput closer to 6 GB/s. I'd be curious to see the results of running `cargo +nightly bench` in the [https://github.com/BLAKE3-team/BLAKE3](https://github.com/BLAKE3-team/BLAKE3) repo on that processor.

<comment><USER3> I updated the post to reflect the numbers I get from the native rust implementation's benchmarks (instead of SMHasher's copy of the C code): 66 ns and 5.5 GB/s.

However, I don't see any dependency chain between iterations in the short- input benchmarks; the numbers don't necessarily reflect latency as much as throughput when hashing a lot of short inputs independently (a rare situation).

Even SMHasher gets that wrong: writing some of the previous iteration's output to the new hashed data, or using it to update the "seed" may not suffice, depending on the algorithm. It's probably safest to derive the address of hashed data from the previous hash value; I think this would look like `slice.split_at(prev_hash & 8).1.split_at(hash_size).0` in Rust, where the input `slice` is padded with 8 extra elements.

<comment><USER2> > I updated the post

Thanks for taking the time to do that!

> SMHasher's copy of the C code

It looks like that copy is old, but still I wouldn't expect it to be ~4x slower. My guess is it's some build configuration issue excluding the AVX-512 code. It's on our todo list to make a reusable CMake build setup for our C implementation, but we haven't gotten to it yet.

> the numbers don't necessarily reflect latency as much as throughput

That's an interesting point. What's an example of an application that needs to hash a lot of small inputs, with data dependencies between them?

<comment><USER3> > That's an interesting point. What's an example of an application that needs > to hash a lot of small inputs, with data dependencies between them?

For short inputs, we want to estimate the time that elapses from the moment we know what data to hash, to the moment when we know that data's hash value. For example, a realistic application might hash one small input and immediately need the result of the hash to, e.g., determine where to probe in a hash table.

When a benchmarking loop does not introduce data dependencies between iterations, it lets hardware superscalar and out-of-order execution overlap the computation for multiple hashes; when we don't need the result of `hash(x)` to start `hash(y)`, the time it takes to compute `hash(x)` and `hash(y)` is often less than twice the time it takes to compute `hash(x)`. For short inputs and simple algorithms, we might actually observe that it takes exactly as many cycles to compute one or two independent hashes (for example, that's what we observe for UMASH on <= 8 bytes). Did we improve the latency of our hash function by computing two values in a loop? By most people's definition of "latency," that's a no. What we did do is improve the throughput, for independent computations. However, the throughput on short inputs is rarely what matters... and, for longer inputs, overlapping the first or last couple iterations is essentially measurement noise.

In a pure hashing loop, we don't really have anything to block execution on the output of the hash function. We can come close by making each call to the hash function depend on the previous call's result: this way, the average time it takes to compute one hash in a series of n will roughly match the time it takes to fully compute one hash.</comment></comment></comment></comment>


Ask HN: What stack should I be using? - <AUTHOR>

I come from a very corporate world (.Net, some Java, etc..) I want to build a fairly simple service that checks to verify if a website is up and gathers some information regarding loadtimes, etc... Nothing that hasn't been done before. My questions isn't HOW CAN this be accomplished but rather HOW SHOULD this be accomplished given the vast number of good "web stacks" out there and my rather limited experience with any of them, I am looking for advice on which route I should take? <comment><USER2> Base your stack on the readily available talent to develop in it. If that's you, go with what you know.

Any of the major stacks out there, both FOSS and commercial, will be perfectly fine for what you're looking to do.

</comment><comment><USER3> I think for this type of project Sinatra and MongoDB would work great. I've used this setup to build web services before with great success.

</comment><comment><USER4> As far as the server portion, I am a big fan of nginx. The rest of it doesn't really matter so long as you're comfortable with it.

</comment><comment><USER5> Go with what you know unless there is a significant return on paying the dumbtax.

<comment><AUTHOR> The problem with going with what I know is that it is mostly MS technologies which involve some licensing costs. Also I find that I am more motivated to work on a project when I am learning something new rather than just repeating things I have done before!</comment></comment>


Signal: The Pros and Cons of a Truly Private Chat App - <AUTHOR> https://www.wsj.com/articles/signal-the-pros-and-cons-of-a-truly-private-chat-app-11592127002 <comment><USER2> Why Signal is marketed as a "private" application when in order to even evaluate it, users needs to give away their phone number, which can be considered as one of the most private things that a person can have?

They even share the phone number with some unspecified thirdparties, according to the privacy policy:

> Third Parties. We work with third parties to provide some of our Services. > For example, our Third-Party Providers send a verification code to your > phone number when you register for our Services.

I would be grateful for explanation.

<comment><USER3> I think the answer to that question is in the wording of the question itself. "One of the most private things." Make a list of those most private things and then evaluate the various messenger apps. Count the number of things on your list that are sent to each app's servers.

I don't know what's on your list, but I know what's on mine, and no other messenger apps I've looked at gets below 1 item. What that item is varies. Which suggests to me that getting below 1 is difficult and that it might even be impossible.

<comment><USER2> I have a private Jabber server (ejabberd) on my own VPS and my friends are using it to contact me.

And before this, I was using IRC, so the server got my IP address and nothing more.

My phone number is way more private than my IP address, which is dynamic anyway.

I see lots of options that doesn't require giving up anything of importance.

<comment><USER3> That jabber server presents no problems for you since you're the server operator, but your friends are giving you a complete list of their contacts, and metadata about their messages too. You take your own privacy seriously and ignore that of your friends. (Relevant anecdote: I know a case where a such a server admin discovered that his SO and a friend were messaging from the same residential IP address before breakfast.)

If you don't give your friends access to your server, this issue is removed, of course. But then you don't market anything and have raised a giant usability obstacle to actually using the server for communicating.

<comment><USER2> Even if we drop all the facts about technicalities about this server (stored on an encrypted container, doesn't log, uses ssl, etc), I fail to see how a telephone number can be compared to a contact list in the privacy scale. The first one is probably top 3, where the second one could probably be maybe on 10th place (it's probably much higher if the user is doing something illegal though). You probably might argue that the privacy scale varies for different people, and of course this is true, but the telephone number is always more private than the contact list given that it's impossible -- in some countries -- to buy a SIM card that isn't tied to the citizen ID. So, Signal ties its accounts to my tax reports in a way. How's that private?

But even if it can be compared in some way, then Signal requires both (phone + list), when I require just one (list), plus it's possible to set up different accounts on my server to diffuse the contact list if needed, what isn't possible on Signal. IP address requirement can't be removed, so I'm skipping it completely.

Well, unless your comment wasn't about comparing Jabber to Signal, but just to point out privacy issues on my Jabber server, then OK. I understand and I agree that I don't follow every privacy standard (I don't have a privacy policy for example), but since I know exactly what's going on, I'm 100% sure that even my light take on the privacy protocols, my server is way more private than Signal ;).</comment></comment></comment></comment></comment>


Ask HN: Who's running a profitable newsletter? - <AUTHOR> How do you do it and how much are you making? <comment><USER2> Hacker Newsletter ([http://hackernewsletter.com](http://hackernewsletter.com)) makes a few thousand a month from sponsors. It could easily make more if I were more of a salesperson, but I'm happy with it as is. Just to be clear though, it took some time to get to that. I'm actually about to hit the seven year mark and issue #357. Speaking of... I'm working on tomorrow's issue as I type this!

<comment><USER3> I'd really like something like this in podcast form. Summarize the best links and maybe invite some highly rated commenters on for discussion.

<comment><USER4> We do that for tech on Charged podcast, and phone people in the industry for comment (recent guests include Keen.io, CEO of DigitalOcean etc). Try it out? [https://char.gd/podcast](https://char.gd/podcast)

<comment><USER5> The podcast appears to be hosts discussing their life in tech along with some current tech topics instead of focusing on summaries of specific content -- very reminiscent of TechZingLive. John definitely has a lot of connections in the valley!

</comment></comment></comment></comment><comment><USER6> I am, at [http://nowiknow.com](http://nowiknow.com)

It's a general trivia email. Every day I send a fun fact of the true story behind it.

Been writing for seven years. Not going to disclose how much I make a month, but I describe it as not quite full time job money but a lot more than beer money.

<comment><USER7> How do you monetize?

<comment><USER8> Patreon ([https://www.patreon.com/NowIKnow](https://www.patreon.com/NowIKnow)), and I'm guessing some other sources like syndication to other sites

<comment><USER6> I actually very rarely get paid to syndicate my content out.

</comment></comment></comment></comment><comment><USER9> I run The Sizzle ([https://thesizzle.com.au](https://thesizzle.com.au)), which is a daily roundup of tech news with an Aussie slant. Any Australians who enjoy HN should check it out!

I've got 445 subscribers that pay $5/m or $50/yr for it. No ads, no tracking, but I do insert affiliate links - primarily eBay.

Costs me about ~$1000/yr to run (Mailchimp, web hosting for a Wordpress blog & Discourse forum and Zapier costs mainly).

This financial year (July 1st 2016 to June 30th 2017), revenue sits at about AUD$18,000. I expect around ~$30,000 next year if there's 0% paid subscriber growth and affiliate link revenue stays the same.

<comment><USER10> I'll checkout your news letter mate, cheers.

Those running costs, the $1,000/year, seems a bit high. Should be able to get that down I reckon? I'm willing to help out on this front for a free sub' :)

Let me know.

<comment><USER9> Thanks for subscribing! I reckon you'll like The Sizzle.

I'm working on getting costs down, but prefer to put my energy into content and marketing at this stage.

<comment><USER10> I'd love to get your insights on marketing, actually. A friend and I have started a YouTube channel which we're getting back to this next few weeks.

Any reading tips and ideas on marketing?

<comment><USER9> I don't really have any insights into marketing. I'd say that's what I struggle with the most. I was able to cheat a bit by having a bit of a following already via other projects I've been part of. Expanding out of that circle has been pretty hard.

<comment><USER10> Thanks for the heads up. I have a better idea of what to expect, then :)

</comment></comment></comment></comment></comment></comment><comment><USER11> I run Tedium ([http://tedium.co](http://tedium.co)), a twice-weekly newsletter that covers obscure topics—half the time tech, half the time not. I've been doing it two and a half years.

I make money from a variety of sources on it, including affiliate links, sponsorships (I recently had some success with [http://upstart.me](http://upstart.me) on this front), donations from readers (both Patreon and PayPal, because folks want options), banner ads, and fees for syndicating the content to outlets like Vice's Motherboard.

The pieces are written more like stories than link roundups, giving them an evergreen appeal. This week I wrote about the history of the 911 system; last week I wrote about CGA graphics and Windex. It actually has a smaller profile than my last project, ShortFormBlog, but it's more sustainable from a financial and work-life balance perspective.

Last month, I did a T-shirt sale with the help of a vendor (Vacord Screen Printing, [http://vacord.com](http://vacord.com)) and made a few hundred dollars through that.

All of this together is not enough to stop me from working a day job, but the mixture of sources and the fact that I syndicate content helps build exposure and ensures that if one source is weaker than another on a different month, the whole machine doesn't fall apart.

If you want to run a profitable newsletter, be willing to rely on more than one revenue stream.

<comment><USER12> I signed up. Well, I clicked the button and it turned blue. No idea if it went through. Perhaps a success message would be more clear?

<comment><USER11> It has a success message—a script runs that forwards you to a different page in case of a successful signup.

</comment></comment></comment><comment><USER8> I don't run these but here's a couple that I know of:

\- Stratechery (Ben Thompson) - $100k/month (conservative estimate) via subscriptions ([https://www.stratechery.com](https://www.stratechery.com))

\- WTF Just Happened Today (Matt Kiser) - $8k/month via Patreon ([https://www.patreon.com/wtfjht](https://www.patreon.com/wtfjht))

<comment><USER13> The monthly subscription price for Stratechery is $10/month. Are you saying 10K people are paying for it?

<comment><USER8> Yeah, at the very least - there were 1K people paying back in November 2014 ([https://stratechery.com/2014/update-stratechery- membership-p...](https://stratechery.com/2014/update-stratechery-membership- program/)) and it's almost surely grown exponentially since.

<comment><USER14> I've been a happy paying sub of Stratechery since October 2015, and would be glad to discover that subs have 'almost surely grown exponentially since [November 2014].' Just wondering what your basis for that assertion is? Looking at (admittedly poor) proxies like Twitter followers, Facebook fans, and estimate domain visits from various sources I don't see any sort of exponential growth...though to be fair the sources I am looking at go back to mid-2015. Again, poor proxies and would be happy to know Ben is doing this well.

<comment><USER15> What do you get out of your subscription? I love Ben's podcast (exponent.fm) but cannot bring myself to pay the monthly subscription.

</comment></comment></comment></comment></comment><comment><USER16> [http://www.tittietime.com](http://www.tittietime.com)

(though the landing page is SFW, the newsletter is not)

I use the newsletter to market tshirts. I sell through about 100 of each design over the course of 2 months. It pays for hosting and funds the next shirt.

List growth has been slow and steady and im looking to increase my shirt order on the next design.

<comment><USER17> Haha what a great domain name! I'll have to check it out when I'm not at work.

</comment></comment><comment><USER18> I'm running and moderating all the newsletters of the LibHunt Network - [https://www.libhunt.com](https://www.libhunt.com) . There are 18 "Awesome" Newsletters with around 5,000 subscribers altogether. The newsletters are making some money and there is interest in them definitely. The sales part is the most difficult one though.

My most popular newsletters are about Python ([https://python.libhunt.com/newsletter/58](https://python.libhunt.com/newsletter/58)), Go ([https://go.libhunt.com/newsletter/58](https://go.libhunt.com/newsletter/58)) & Ruby ([https://ruby.libhunt.com/newsletter/58](https://ruby.libhunt.com/newsletter/58))

P.S. it took me around 13 months to reach the 5k subs...

</comment><comment><USER19> CB Insights (www.cbinsights.com/newsletter)

We have 289,000 on the newsletter which represents a large group of VC, tech M&A, corporate strategy and startup folks interested in data-driven discussion of technology trends. It's the primary way we sell subscriptions to our SaaS platform.

We messed around with ads in the newsletter but they don't monetize nearly as well as the "house ads" to our data/product or to our events.

It's our company's golden goose.

<comment><USER20> Dude, I love your newsletter. It is literally an immediate open, every time. It is my goal to get my sporadic thoughts on tech published at the bottom.

That and the Quora digest are the only non-work emails I read.

<comment><USER19> Awesome to hear. Love you :)

</comment></comment></comment><comment><USER21> I don't know if they are profitable, but Peter Cooper has a whole bunch of good ones at [https://cooperpress.com/](https://cooperpress.com/)

<comment> ryan-allen They'd have to be, he has staff and everything!

I've been subscribed to many of his newsletters for years. They are very valuable and well curated, and going through the previous editions is a good way to catch up on a few months of trends and things.

<comment><USER22> Thank you for your support! :)

<comment> ryan-allen No, thank you! (:

</comment></comment></comment></comment><comment><USER23> According to Indie Hackers, Scotts Cheap Flights (discount airfare newsletter) does $320k/mo

Interview here: [https://www.indiehackers.com/businesses/scotts-cheap- flights](https://www.indiehackers.com/businesses/scotts-cheap-flights)

<comment><USER24> I believe it. I happily pay the $5/month for tips on upcoming flights. I love solo travel but I haven't been to a lot of places (just getting out of college) so I don't have too many specific preferences about where I want to go. Saving ~$400 per each of the 2 trips I've booked because of Scott's Cheap Flights actually makes my trips affordable.

</comment></comment><comment><USER25> HNDigest ([https://hndigest.com](https://hndigest.com)) is profitable some months, others not so much. Turns out it's quite expensive to send a ton of emails if you don't have sponsors.

I should probably spend more time finding sponsorship.

<comment><USER26> I read hndigest every day! Thanks for making it :)

Question: Is there any way you could make the newsletter so that long titles don't text wrap on wide screens? Example: [http://imgur.com/a/vlCE8](http://imgur.com/a/vlCE8)

<comment><USER25> Hey raybb, thanks for being a subscriber :-)

I see what you mean. I'll investigate it, however designing html emails is kinda like black magic (although less nowadays since Gmail supports responsive design from October 2016) so no promises!

</comment></comment></comment><comment><USER27> My site [https://officesnapshots.com](https://officesnapshots.com) has a weekly newsletter which is basically an email update of the previous week's new content. It is profitable, though just an extension of the advertising options on the rest of the site.

I have a sign up form at the bottom of my site and use double opt-in to make sure people really want to subscribe. I also periodically trim the list down by removing people who don't open or click anything. I figure 1000 subscribers and a 50% open rate is better than 5000 and a 10% open rate as the list is more highly engaged. Plus on MailChimp you're wasting $$ sending to people who don't engage.

<comment><USER28> I've looked at doing this a couple of times by segmenting subscribers that never open or click a campaign. Instead of silently unsubscribing them I send them an email with a GIANT UNSUBSCRIBE BUTTON and explain why they fell into that segment.

The two times I've tried this I've had a number of responses asking why they made their way onto the list as they enjoy the email but block any tracking. Just a word of warning.

<comment><USER22> Removing "inactive" subs has proven to be a dud for me in many ways as well.

The first time I tried it silently and got a lot of people very annoyed they were removed. The second time I actively emailed people and they were similarly offended. I now don't bother (though if open rates were low, I'd probably just do it again).

</comment></comment></comment><comment><USER29> Hi there!

I write cron.weekly [1], a weekly newsletter on Linux & open source. When I started around 2y ago there wasn't much competition.

I'm at 6k subscribers now and making roughly 1k (eur) a month via sponsorships. Members don't pay, it's entirely sponsor driven.

It took a little over a year of hard work for free before the first sponsor landed, right now it's pretty good value for the time I put in. As the subscribers grow, that ratio should only get better.

[1] [https://www.cronweekly.com](https://www.cronweekly.com)

<comment><USER30> Learned a lot of new tools from your newsletter. Thank you!

<comment><USER29> Cool, thank you!

</comment></comment></comment><comment><USER31> Off topic, but I'd pay (a small amount) for something like Need to Know.

[https://en.wikipedia.org/wiki/Need_to_Know_(newsletter)](https://en.wikipedia.org/wiki/Need_to_Know_\(newsletter\))

NtK pioneered some things that got taken up elsewhere: dohgifs highlighted terrible algorithmic placement of online ads next to news stories. Private Eye now does this as Malgorithms.

A newsletter like this would fare better now we have things like Patreon.

</comment><comment><USER32> The listings project is not mine, but I've always admired Stefanie and her list:

[https://www.listingsproject.com/](https://www.listingsproject.com/)

It lists artist studios, coworking and apartment sublets, mostly in NYC and probably does about $500k in revenue year.

Weekly newsletters have been averaging about 300-325 listings @ $30 per week. There are also sponsored emails that I'm sure are in the thousands of dollars per email.

</comment><comment><USER33> Timmerman Report (biotech) is doing well, judging by some comments I've seen posted by its founder, a former Xconomy journalist who started the newsletter full time about two years ago. Not sure if it's profitable, though.

In the indie book publishing world, I subscribe to a paid newsletter called The Hot Sheet ([http://hotsheetpub.com/](http://hotsheetpub.com/)). I pay $60/year or thereabouts, which I think is reasonable considering the insights, analysis, and tips I get every 2 weeks. I doubt it's a full-time income for the two writers, but on the other hand I don't think it's a full-time writing gig, either.

It's worth noting that in many of these niches there is very little in the way of established trade pubs as print magazines covering the industry have folded or become shadows of their former selves when they moved online. It doesn't surprise me that some of the more talented or insightful writers have decided to launch their own brands and build their own audiences.

</comment><comment><USER34> Presumably not profitable at this stage, but inside.com founded by (I believe...) Jason Calacanis to try out lots of different e-mail newsletters currently he's funding it, they have some advertisers and I _think_ they are experimenting with user pays?

Another one I know of that is successfully getting a good following is www.thesizzle.com.au

</comment><comment><USER28> RWD Weekly ([http://responsivedesignweekly.com](http://responsivedesignweekly.com)) has two advertising spots in each newsletter. The primary spot runs for $450-500 and promoted link runs at $130 a week.

The newsletter fills probably 3/4 of the placements and then I use the other placements to promote conferences that I love. This is usually in exchange for a ticket (which I give away if I can't attend) and media sponsorship which gives the newsletter some extra exposure.

I only introduced advertising after the subscribers reached over 5000 and the Mailchimp costs became a little too much, now it's sitting just over 29k subscribers. It's a great side project that I'd love to invest more time towards but at the moment it makes enough to cover mailchimp, servers, cloudflare, speedcurve and allows me to patron a couple of other newsletters that I love.

</comment><comment><USER35> [http://uxcurator.com](http://uxcurator.com) (UX newsletter) Posted my site on Hacker News and Reddit for the first launch, and it got a few hundred subscribers, and it has been gradually growing since last 2 years. And it roughly makes ($AUD)1k a month via sponsorships.

</comment><comment><USER36> Run a small weekly newsletter that covers the Indian startup ecosystem. Will be putting out Issue. 34 tomorrow. Gets me 10-12 beers a month. No initial cost to it. Archived via github pages and send via the free mailchimp tier. ([https://www.tinyletter.com/harshalbot](https://www.tinyletter.com/harshalbot)) Archives: ([http://www.harshalgupta.me/categories/#newsletter](http://www.harshalgupta.me/categories/#newsletter))

</comment><comment><USER37> I run growth.email ([http://growth.email](http://growth.email)) which is a weekly growth marketing email, listing 10 articles in each issue. I started it at the beginning of this year, have around 1,700 subscribers and make $40 a week from one single ad in each issue.

At this stage, my pitiful MRR covers costs, etc but not all the time I put in. Soon as I get to 10k+, at $25/cpm it starts adding up to $1k a month, which is a little less painful to look at. :)

</comment><comment><USER38> We're running [http://androidweekly.net](http://androidweekly.net) and [http://swiftweekly.com](http://swiftweekly.com)?

It was roundabout 5 years just editing and making no money. Now it's making money - but just a side income.

1\. Content is king! 2\. Start to build a community (if you link someone in your newsletter just ping him on twitter). 3\. Go to community events.

Doing ads on Facebook and Twitter actually didn't work that well.

</comment><comment><USER39> Newsletter ads are very effective (and therefore can be extremely profitable) _if_ you have an audience that people who control marketing budgets want to reach.

That said, email is just another medium. There's no one way to make money just like there's no one way to make money with an app.

I'm guessing it's not the kind of newsletter you meant, but we make millions selling ads in B2B email newsletters.

<comment><USER40> I'm intrigued... What kind of newsletter it is then? Print? And what B2B sector, if you don't mind telling. Thanks.

<comment><USER39> Email newsletters, though that's just one way people get our content. You can see essentially the same thing on our websites, or following us on twitter, etc. Email is big, though. We have publications in over a dozen sectors see e.g. retaildive.com, utilitydive.com, healthcaredive.com

(p.s. I'm hiring developers and data engineers)

</comment></comment></comment><comment><USER41> Stratechery? Ben's monetisation is the newsletter

</comment><comment><USER42> Hacker News Books [http://hackernewsbooks.com](http://hackernewsbooks.com) is profitable from Amazon referrals, $200-300/month. I am planning to look for some sponsorship but have not had the time. ~1500 tech-savvy readers in the newsletter + several thousand on the web.

</comment><comment><USER22> Somehow I missed this interesting thread till now, but I run about 11 of them with a total of around 370K subscribers in the developer space. I'm coy with money but let's just say we're 'approaching' $1M revenue and we are 8 full- timers plus several external curators.

<comment><USER43> How do you do subscriber acquisition?

</comment></comment><comment><USER44> FYI I don't know if the offer is still out but I remember seeing this a little while back [https://twitter.com/peterc/status/717393310080507904](https://twitter.com/peterc/status/717393310080507904)

</comment><comment><USER45> [https://uimovement.com](https://uimovement.com) \- ~16k subs, $500-1000+ a month from sponsors. I hardly ever do sales and spend ~1 hour a week on this - I'm sure it could be more profitable with more effort.

</comment><comment><USER46> I worked at SmartBrief (smartbrief.com), a company that creates newsletters on behalf of trade associations. The advertising would often yield impressive rates because of valuable niche audience, e.g. heavy equipment financing executives.

</comment><comment><USER47> I run [http://frontendweekly.co/](http://frontendweekly.co/) but haven't monetized it yet. It has ~2k subscribers (plus ~3500 on medium at medium.com/front-end-hacking)

</comment><comment><USER48> I run [https://FoundersGrid.com](https://FoundersGrid.com) and we sell our weekly sponsorships ($500 each) most weeks. I'm currently editing edition #358 right now :)</comment>