Knocking down a shed with an air cannon - <AUTHOR> http://www.youtube.com/watch?v=IyAyd4WnvhU&eurl=http%3A%2F%2Fgizmodo.com%2F5326372%2Fgiant-gas%2Bpowered-vortex-cannon-destroying-shed-filmed-at-1300fps%3Fautoplay%3Dtrue&feature=player_embedded

<comment><USER2> The travelling vortex ring of gas is known in literature as the Helmholtz soliton.

Scroll over to "Five Minutes of Knot Theory History" for a short video from demonstration class: <http://www.southalabama.edu/mathstat/personal_pages/silver></comment>


France excels at R&D, but Academia is overdue for disruption - <AUTHOR> http://www.rudebaguette.com/2012/05/09/r-and-d/?utm_source=hackernews&utm_campaign=hackernews

<comment><USER2> I feel one big thing that the "cool" (as opposed to us 'uncool' academics) can miss is that good research is hard. It is common to spend months on topics on areas that don't work out, and years on topics that do. It doesn't fit the modern high-speed of the internet, and it doesn't fit in 140 characters.

And of course, most research isn't particularly interesting to people outside a fairly small area. I might come up with a new way of doing something important in my research area 50 times faster than we did it before, but explaining what I did struggles to fit in 15 pages, never mind 140 characters. Personally I can't imagine what interesting research related-comment you could fit in a tweet. Then again, I've never got twitter (which isn't something I'm proud of -- sufficiently many people are using it that I am sure I'm missing something.. just not sure what).

<comment><USER3> Agreed. Besides the length issue of a tweet (which don't apply to blog posts, as we all know from Steve Yegge) I also think that there is no incentive for a researcher to participate in the social web--at least none that I can think of. Actually, quite the contrary is true: yesterday's post on academic blogs linked to the "serious engineering" blog, which contains the following line in a post about time management:

      Do not read blogs and above all do not write them.

AFAIR, Matt Might had a somewhat different point of view, where he elaborates on strategies how to publish blog posts out of presentations, etc. To me the social web compares very well with the TV on the time-sink scale: you save a lot of time by not doing it.

<comment><USER4> I'm fairly sure that line from Anthony Finkelstein is tongue-in-cheek.

Like any profession, academia is about networking. Social media can really help here, and I think academics are slowly understanding this. There are two problems: blogging/tweeting are lower priority than grant-writing, teaching, marking, and paper-writing; and academics are usually older and (in my experience) older people don't 'do' social media as much.

But in software engineering, at least, there is a good community of people on social media. For example, the Never Work In Theory blog (of which I'm an author), and various academics on twitter, like @profserious or @avandeursen.

</comment></comment></comment><comment><USER5> As someone tangentially involved in the administration apparatus for large, well utilized clusters, I have to dispel some myths related to "Cloud" services and Amazon EC2 for computation. First, if your school has institutional cluster services, these are FAR cheaper than cloud options. Secondly, the type of systems that are good for scientific computation are not the type of boxes typically deployed in the cloud; try to find a 48 terabyte memory node in the cloud.

OSG/Teragrid are much better options than the cloud, though you do have to jump through some hoops to access them. Believe me when I say it is worth it though.

<comment><USER6> Definitely agree. To give a ballpark figure, Compute Canada, the governing HPC body in Canada provided a cost estimate to researchers who applied and received dedicated computer allocation. Although, all this computer time is actually "free" to the scientist:

"The average RAC award in 2012 was 500 core years and 50 TB years. From Penguin Computing's website [list pricing from Feb 10th, 2012] the cost to purchase a similar amount of computational time and ability would be $450,000. ($600 / server month where each server provides 8 cores) To purchase 50 TB from SDSC [again, list pricing from Feb 10th, 2012] it would cost $30,000. ($600 / TB Year) Making the total value of the average RAC award nearly $500,000. The cost to Compute Canada to provide this level of award is $178,000 and that includes all aspects of user support, training and other aspects not covered by commercial clouds." ([https://computecanada.ca/index.php/en/component/content/arti...](https://computecanada.ca/index.php/en/component/content/article/9-english- catogories/169-cost-2012-rac-awards))

As a side-note, my groups award was above the average, The email to our research group stated: "Providing these resources to your research group costs Compute Canada roughly $4,669,960." I don't even want to calculate how much that would cost on EC2!

<comment><USER7> 500 cores is approximately 32 cc2.8xlarge instances (16 cores/instance). If you are running a highly utilized cluster, i.e. you are going for a one year heavy utilization reserved instance, the compute part is going to cost you ~$262,000. If you went with a 3-yr RI, it would be $183,000/yr.

Or to put it differently, ~$0.04/core-hr prior to any volume discounts.

</comment></comment></comment><comment><USER8> The argument about France's strength at the end of the article is anecdotal (and not argued at all), and the title is misleading.

(and as a French CS student who did his undergrad in France and started a PhD in the US (and have many friends in PhD tracks in both systems), I'd actually argue that France is better at "pure/abstract research" rather than R&D. Inria is a very unusual organization, not representative of research in France at all)

<comment><USER9> Some data: Inria is (AFAIK) one of the 3 major public research institutions in France: CNRS (the largest, multiple scientific fields, 26k people), Inria (CS, 4k people), INSERM (Medical, 6k people). There are others, but they are much less staffed. Anecdotally, I worked in a CNRS lab and I can tell you that it was very much applied. But applied research was the stated goal of the lab, and I can't say about the rest of the CNRS.

<comment><USER10> You forgot CEA (nuclear and renewable energy, microelectronics, defense,... 16k people).

<comment><USER9> You are right but it seems that the CEA is an établissement public à caractère industriel, while the ones I cite are établissements publics à caractère scientifique.

However, you are right, this distinction seems pretty arbitrary to me, as the ONERA (aerospace) too is classified as "industrial" and not "scientific" research establishment.

</comment></comment></comment></comment><comment><USER11> I think this post misses a number of things. For example, take peer review. The system is not perfect--but peer review takes time and expertise. It's not as simple as a "like". When I review an article--I check for consistency. If necessary, I go through the references. At times, I make sure that errors have been propagated correctly. Then, there are broader issues such as relevance. In short, it's labor intensive and sometimes there are bad referees--but overall, I think the system is better than a simple comment system. In modern terms, you might call it "curated" content--the referees and editors help increase the signal to noise ratio in the sea of papers that are submitted.

For conferences--while the presentations are important, so are the conversations in the halls, at dinner, etc. It's useful to have face to face conversations with your collaborators and to make new ones.

There have been some changes--like for initial program committee meetings for conferences sometimes take place using webex/gotomeeting given the diverse timezones/countries of members. Some experimentation has been done with using second life for the first stage of grant reviews--but at the end, physical meetings are necessary. For conferences themselves (in physics), you are paying on average less than $1000--even for conferences with ~10,000 people. But--conferences do cost money to organize--I made a mistake for the first workshop I organized by charging too little...

Things are gradually improving--slides from the invited talks are hosted online for the major conference from my field. Mobile schedules could be improved...

Others have commented on the EC2 question--but one other thing to consider is whether their architecture is suited to a given problem. We're investigating this now.

While Hadoop is good for some problems, it may not be appropriate for others. This is generally true of a number of the points in the article--use the right tool for the right job--don't just use it because it is new...

</comment><comment><USER12> There actually is a really strong community of mathematicians at mathoverflow.net. Also, I know quite a few academics who tweet about their research but these are definitely the exception rather than the norm.

A simple reason as to why academics aren't "socially connected" is that they don't need to be. The academic social network exists informally and is more tightly knit than a social network of say programmers, so I don't necessarily have to be your facebook friend or follow you on twitter to be able to get in touch with you through 2-3 hops

As far as blogs are concerned, one reason to write blogs is for purely didactic purposes. I definitely know tons of Grad students who use to prepare their notes and put them on their web pages or local servers to fulfill that need. The other reason: To transmit your ideas to wider audience is much a more harder problem to solve. Mathematical abstractions get progressively harder to communicate if your understanding of the basics is weak, example, you would definitely need a background in vector spaces to understand functional analysis. I remember reading a blog recently where the author ( a machine learning academic) had written about his experience in implementing a stochastic gradient solver for online learning in Clojure: There were a couple of comments complaining that there was no context. While, I definitely see where those folks are coming from, it would take too long and a good deal more posts to be able to break down a couple of book's worth of ideas before you get to what you want to talk about.

</comment><comment><USER13> Reading and writing tweets is a pleasant time-waster that should be seriously limited if you want to achieve something serious, not encouraged. The same applies also to HN, of course, where I am now wasting time to avoid research :P

There are enough (and too much) scientific stuff to read in any interesting, active research topic; the bottleneck is in the researcher's ability to read and understand, not in lack of content.

And even peer reviewed articles in respectable publications quite often are garbage and/or wrong. If your proposal "let's do stuff this way" isn't even peer reviewed, then it's most likely not worth reading - since there's a too high chance that it's one of:

a) duplicate of something that was already done in 1970'ies by someone else, and abandoned as it's not practical in real life due to X,Y and Z that you haven't considered yet; b) misleading or simply not true, as it's not researched / repeated / analyzed enough; c) Simply useless.

After all, if it was correct, novel and interesting, then there are quite a lot incentives for putting it to 'traditional' publishing; so if you're not publishing it 'properly' then it's an indication that you are doing it because your content is not publish-worthy, as people tend to squeeze as much publications as they can out of any decent, publish-worthy research.

</comment><comment><USER14> Actually, call me a twitter-blase, but I'm not so excited and upbeat about Twitter anymore. The fact that people tweet stuff during a presentation don't get me excited. I'd rather they listen and learn from the presenter. Then I can say mission accomplished (as a conference organizer).

I just know too many great people who don't spend any time on Twitter, and frankly, why should they? I see a lot of self-promotion, "social media" experts retweeting to death. Real people saying interesting things? Some, but not enough to keep me engaged.

</comment><comment><USER15> I dread the day that scientists try to condense their research into 140 characters. Reading well thought out blog posts would be great, but to be honest, the ideal would simply making it easier for me to find out what the best papers are.

</comment><comment><USER16> I always assumed that scientists generally do not participate in the wider web as much due to having much faster academic links than the average net user could even dream of.

However, that said, there are many things that can be improved upon that the wider web would be great for. Academic publishing is one obvious one and the Elsevier boycott is a strong indication that this is well underway.

Data collection and sensing is another, which with the new class of cheap networked devices like the Rasperry Pi, as well as pads and smartphones, could well be something that is worth putting some thought into.

Distributed computing and mass collaboration is another obvious one, however it seems that academics can often get this more or less for free, if you look at examples like folding@home and the NASA moon crater identification project thingy, so there might not be so much requirement for things like EC2 or mechanical turk, when compared to getting people to donate resources for nothing.

<comment><USER11> Also, a friend's lab at NIH is using mechanical turk...

<comment><USER16> That's cool, I'm more than prepared to find out I'm talking bollocks on this.

Any idea what they are doing with it?</comment></comment></comment>


Ask HN: How many hours do you spend coding per day? - <AUTHOR> Hey guys, How many hours do you allocate writing code? What advice do you have on how often a beginner (Web Developer) programmer should code per day? Cheers <comment><USER2> 5-7 hours. (Full time job)

Depending on side projects add another 1-3 hours to that.

I wouldn't really put a time frame on it. Just think of a project you want to build and work on it when you get the time. I usually end up spending every waking hour on a project until I get a solid base. After that I try to work on it for an hour or two every night.

Cheers!</comment>


App Engine SDK 1.3.5 - New Task Queue, Python Precompilation, and Blob Features - <AUTHOR> http://googleappengine.blogspot.com/2010/06/app-engine-sdk-135-released-with-new.html

<comment><USER2> The pre-compilation of python code appears to significantly decrease the time required for cold starts. That's just great. Awesome team, awesome platform.

</comment><comment><USER3> Does anyone use AppEngine in production? I am not trying to troll but we've have had pretty poor performance getting data out of their datastore. We only have a couple operations apps running on it and I could not imagine running anything that need to perform on GAE. BTW - We've had slowness in both Java and Python...

<comment><USER4> Is anyone using Java on GAE? I love Java in general but for web dev I never found a great framework. Was considering learning Python/Django. However, the one thing about Java is that I might be able to go with Scala and/or Clojure at some point.

<comment><USER5> lift on GAE:

[http://distractable.net/coding/google-appengine-language- per...](http://distractable.net/coding/google-appengine-language-performance- comparison-followup/)

[http://groups.google.com/group/scala- london/browse_thread/th...](http://groups.google.com/group/scala- london/browse_thread/thread/4facf58a93026d68#)

</comment></comment></comment><comment><USER6> Is Python pre-compilation just compiling to bytecode as in .pyc files, or is it compiling to native code?

<comment><USER7> Most certainly to .pyc. Native code is the realm of a JIT runtime.

</comment></comment><comment><USER8> Still waiting for that full text search API. I believe the ticket was 'started' in October last year. [http://code.google.com/p/googleappengine/issues/detail?id=21...](http://code.google.com/p/googleappengine/issues/detail?id=217)

<comment><USER9> why is this downvoted? i completely agree.

<comment><USER8> I didn't mean it as a complaint either.

Just to clarify: I am a pretty happy user of GAE. Full text search is one thing that is missing from the feature set that could make my life as a GAE developer a lot easier.</comment></comment></comment>


Show HN: Mindfulness in MVP Validation and More in MindfulDevmag #5 - <AUTHOR> https://mindfuldevmag.com/issues/issue-5-mindfulness-at-work/ <comment><USER2> A developer oriented mindfulness magazine is an interesting idea. Some of the articles are more general instead, like snacking and Part 3. Developer focus of the articles differentiates.

<comment><AUTHOR> Thanks for the feedback. My goal is to bring mindfulness closer to developers using a mix of developer-centric topics and some more general topics as we are still humans and have a life outside of code :-)

Any topic suggestions? Anything you'd like to learn in the next issue?

<comment><USER2> As a Hacker News reader, I'm more interested in individual articles than links to magazine size content. Maybe submitting individual articles could provide finer grained feedback from the potential audience. Individual articles seem more viral than newsletters, too.</comment></comment></comment>


Our beloved Landau-Lifshitz books are available online. For free - <AUTHOR> https://www.reddit.com/r/Physics/comments/1dmxq7/our_beloved_landaulifshitz_books_are_available/ <comment><USER2> They desperately need LaTeX-ing but as far as I'm aware the English translations are still under copyright even if the original russian is not.</comment>


Women and mixed gender teams have raised a record amount of VC so far this year - <AUTHOR> https://techcrunch.com/2018/11/04/female-founders-have-brought-in-just-2-2-of-us-vc-this-year-yes-again/ <comment><AUTHOR> It leads heavily with rage factor and "How to lie with statistics." But the last three paragraphs or so have a spoonful of genuine data that suggests modest improvements.</comment>


Show HN: Community to help Provlem seeker – Provlem.com - <AUTHOR> https://provlem.com/problems <comment><AUTHOR> Hi, My name is Rocky Sharma.

I am the founder of provlem.com and I wanted to build crowdsourcing consultancy community for quite some long time.

The mission to start something like what today is "provlem.com" begin a long time ago and with multiple stories and events of other people's life including mine - It was just getting hit up pretty badly to me on every occasion.

People in today's world has lots of problems and with increasing population and competition - Situation is more worst than you can even think.

There are enough of stories from suicide, depression, failure, unemployment to bully or getting dominated from bad people in school, college, work, politician to bad parenting.

The stories and problem go on and on but there are very fewer people who are lucky enough to have motivated people around them to get over the problem and kick-start their life with vengeance.

I hope, the IDEA of building the site to help provlem seeker is fulfilled with "Provlem.com"

Couple of features, that is ongoing -

        Video calling option

        In built Wallet for user to pay/hire in case of paid consultancy.

        Improving chat option with emoji and other stickers.

Anonymous and non-anonymous Chat between user is already there.

Any further suggestions would be appreciated.</comment>


Scrollbars: Why is Apple eradicating a linchpin of user interface design? - <AUTHOR> http://www.slate.com/articles/technology/technology/2011/11/computer_scrollbars_why_is_apple_eradicating_a_linchpin_of_user_interface_design_.html <comment><USER2> As soon as I installed Lion, I thought I'd feel the same way.

But your post just made me realize: I haven't missed scroll bars a bit. And if you wonder if there's more content in a window, a tiny jiggle with your finger instantly reveals that.

Interestingly enough, I've even traded my Magic Mouse at work for a Magic Trackpad -- the new paradigm of gestures and swiping etc. is so useful, I don't think I'll ever go back (except when I have to do graphic design work, a mouse is essential).

</comment><comment><USER3> a) Because it's not a "linchpin" anymore. With the advent of touch interfaces (which will sooner rather than later account for most browsing), scroll-wheel mice, and trackpads, the days in which scrolling was best/easiest accomplished by clicking on annoying ever-present pixel-wasting scrollbar arrows have ended. Good riddance to them.

b) Apple didn't eradicate anything; you can still turn the old-fashioned scrollbars back on if you choose. They just changed the default to suit what Apple believes to be what most users will choose, now and in the near future, with the hardware that most of them will be using most of the time.

<comment><USER4> But what percentage of Lion users are on touch screens?

Zero?

Edit: For some reason I'd read the parent as saying that you didn't need visual feedback on a touch screen, which of course, you still don't have with a trackpad. Not sure how I got that.

<comment><USER5> While it's not a touch screen, the track pads on MacBook Pros and the Magic TrackPad for desktops provide many of the touch gestures found on touch devices. So, touch screens? Maybe zero. Touch enabled? Plenty!

And, to be honest, touch gestures in general are a very welcomed change to the OS. I find the use of a mouse only needed for precision control (say, graphical work or gaming!)

<comment><USER4> Yep - in fact, I switched from a Mac Pro to a MacBook Pro largely because there was no way, at the time, to get a multitouch trackpad. I love the gestures.

</comment></comment></comment></comment><comment><USER6> It's incidents like this that always remind me how surprisingly conservative geeks can be about relatively minor changes.

I love the iOS-style scroll bars and natural scrolling in Lion. The fact that Apple is willing to make minor changes like this despite inevitable bitching by geeks is one of the things I most respect about the company.

</comment><comment><USER7> Wouldn't the fact that Apple is able to remove the scrollbars in several situations imply that they aren't a 'linchpin' of UI design?

I rather like that I get a little extra real-estate, but some times I would like a visual indicator that there is more to a page off-screen. The indicator, however, need not be a scroll-bar.

<comment><USER8> Lukas Mathis proposes an interesting solution for the "visual indicator:" [http://ignorethecode.net/blog/2011/08/01/invisible_scrollbar...](http://ignorethecode.net/blog/2011/08/01/invisible_scrollbars/)

</comment></comment><comment><USER9> I'm not sure how people deal with the disappearing scroll bars if they don't have a scroll-wheel mouse. For me the missing bars are fine because I can make them reappear at any time by lightly touching the scroll wheel.

They are also surprisingly nice for the column views on Mac OS X (an interface that basically consisted of a horizontal scroll bar over a range of several vertical-scrolling lists). Now, without scroll bars, the column views look so much more _sensible_ ; before they seemed to be littered with chrome.

I don't think scroll bars should disappear _completely_ though. It seems that muting them (e.g. becoming light gray and translucent, or thinner like they are on Linux) would be enough to keep them out of the way.

It would also help if there were some additional cue, e.g. a "fade-out" effect at the edges where more content is available offscreen.

<comment><USER10> As far as I know, scroll bars do not disappear for third party mice, but they do if you are using Apple's trackpad or magic mouse.

</comment></comment><comment><USER11> I wish I could remember where I read this, or that my Google-fu was strong today, but not too long ago I read an article or mailing list post about (far- future) plans to get away from scrolling as a paradigm for navigating web pages. It is a sort of unquestioned dogma that content must be laid out vertically in a linear fashion. If I remember correctly, what was being proposed was something more contextual or reactive in nature, like flipping pages left and right or some other topology. That doesn't seem like it differs too much from hyperlinks so I must not be recalling some important fact.

Anyways, hopefully someone who knows more about what I'm trying to remember will see this.

<comment><USER12> We had pages before we had computers. Unbroken or variable-broken document flow was a feature computers added.

<comment><USER13> Historically: scrolls existed before pages, though pages were clearly the superior technology.

<comment><USER14> Pages were superior because:

1\. Scrolls were more difficult to handle as you read.

2\. You could jump around to various places in a long book document, but with a scroll you had to manually unravel it to the point you were looking for, a time consuming process.

3\. Books were not without their difficulties, however: <http://www.youtube.com/watch?v=pQHX-SjgQvQ>

But in all seriousness, the scroll concept works perfectly well, in fact better than the book concept, provided you have the right technology to drive it. And modern computers have that technology. I can use a search box to jump to wherever I want. I can quickly scroll up and down in the document using a scroll bar rather than paging through a book.

</comment></comment></comment></comment><comment><USER15> This is one characteristic of Unity (Canonical -- Ubuntu) that I think got it right: [http://design.canonical.com/2011/03/introducing-overlay- scro...](http://design.canonical.com/2011/03/introducing-overlay-scrollbars- in-unity/), which leaves only small indicators until the bar is in proximity to the cursor (or in use). It'd be a nice touch to mobile applications, like with Android, where the scrollbar only needs to be represented by 2-3 pixels.

</comment><comment><USER16> My __only __gripe with the smaller, hiding scrollbars is that window content goes under them and becomes occluded by them, making it near-impossible to click.

Case in point is the Chrome dev tools. Checkboxes for hotswitching CSS rules now lie directly under the scrollbar and I keep catching it when I go to untick one.

Other than that, I really don't miss them at all

</comment><comment><USER17> I'm pretty sure Apple is focusing on creating visual metaphors which have a more complete real-world comparisons. There is no real-world comparison for a 'scroll bar'.

The newer UI systems are imitating paper more accurate: stacks, page turns and scrolling -- the scrollbar has less of a place in that visual metaphor.

</comment><comment><USER18> I recently worked on a friend's macbook and this is the first thing I noticed; I'm a linux guy. After a less then ten second explanation, I got used to it.

Personally, I thought it was a nice touch - there's almost no added cost to the user, more importantly, it cleans up the interface and frees up a few px of width.

</comment><comment><USER19> Actually - my experience of the new gmail interface with chrome is that I get an extra (and wholly redundant) scrollbar as a result of everything being just a little too big to fit.

Even worse the scroll bar that is part of gmail doesn't look anything like native scroll bars.

</comment><comment><USER20> It's still there when you need it. And you can turn them on again if you want (on OS X).

</comment><comment><USER21> Answer: scroll bars suck</comment>


Show HN: my weekend project - branded order tracking for ecommerce - <AUTHOR> https://showparcels.com/ <comment><AUTHOR> Hey guys, I wanted to share this weekend project with you.

Showparcels allows dropshippers/eCommerce stores to create a branded and customized shipment tracking page for their customers.

It also allows to display related products on the order tracking page for up/cross-sell customers when they visit it to check their delivery status. Since many people check the tracking pages very often, you get quite a lot of free traffic you can use to try to convert them again. You are also able to implement your Facbook pixel or any other retargeting pixel on the page.

I've integrated multiple tracking APIs to get shipments data, so it basically works with all the major 600 carriers worldwide.

Please reply to the post if you have any questions or feedback for me!</comment>


So you want to write a type checker - <AUTHOR> http://languagengine.co/blog/so-you-want-to-write-a-type-checker/

<comment><AUTHOR> A follow-up to my "So you want to learn type theory" reading list. Here I show you how to write a simple type checker using JS.</comment>


MySpace to Launch Developer Platform Next Week - <AUTHOR> http://blog.wired.com/business/2008/01/myspace-promise.html

<comment><USER2> You cold have said "API", this is not a press conference, we're all normal here.</comment>


Facebook, Please Don't Let the Mullahs Troll Us [WSJ] - <AUTHOR> https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=1&ved=0CB0QqQIoADAA&url=http%3A%2F%2Fonline.wsj.com%2Farticles%2Fmariam-memarsadeghi-and-akbar-atri-facebook-please-dont-let-the-mullahs-troll-us-1416873076&ei=luJzVPBgioqxBL3FgJgB&usg=AFQjCNF2POLS_-fTYK44dSDalt50k8aAxg&sig2=jTbN-rsEACf0G9g9T63bkQ&bvm=bv.80185997,d.cWc

<comment><USER2> Please don't post Google URLs to paywalled pieces. It doesn't usually work, and obscures the source of the article.</comment>


Microservices Dashboard - <AUTHOR> http://ordina-jworks.github.io/microservices-dashboard/0.2.0-SNAPSHOT/ <comment><USER2> A screenshot would really help in easily understanding this.</comment>


Israel military detects 6 blasts, each 11 seconds apart, before Beirut explosion - <AUTHOR> https://www.reuters.com/article/us-lebanon-security-blast-seismology/seismic-data-suggests-string-of-blasts-preceded-beirut-explosion-israeli-analyst-idUSKCN2591S2 <comment><USER2> Geophysicist here.

These 11 second periodic blasts are due to airguns from a Turkish seismic survey vessel that happened to be working in the region. N.B. they continued _after_ the Beirut explosion.

Here's a (long; thanks Zuck) link to a FB post from IRIS (the Incorporated Research Institutions for Seismology):

[https://www.facebook.com/IRISEarthquake/photos/a.36102058997...](https://www.facebook.com/IRISEarthquake/photos/a.361020589973/10158943990109974/?type=3&__xts__%5B0%5D=68.ARCQ2xtt4S6O1JJO8mz4ReWWCGs8NwcCVEH32leM7QYUR- Bm7TcXyFn0P7i6gkQLJC2Kg5-DSIXusJwqBq85SVzU2NYJomn6xm1bZniYFT4wuxihBPVQ- RU6xhJTIhO5LYfAZa0uUq7uPjriyW1_n8qj_uYB2ozR8Zcv4KFdSxyHbGxmqFGYLwdCsA0kwDe_fwigH1_FfqHjUKav- tNLGZL6VB9v1GGINF656LCAZFtXCPNGrEy3-2ErJkHs5y0lZ_Y6ijrd5RsOLTiDnOx- HUAemv7Cm_rG29dYqdMrzkls05q4YQw2j61z9H7XGjM200V6akNWB-0SvNWuLrCo&__tn__=-R)

</comment><comment><USER3> > "I do not believe that they are associated with the large explosion in > Beirut," Jerry Carter, director of IRIS data services, told Reuters.

> "They could be from a seismic survey," he added, referring to geologists > carrying out airgun bursts for underwater mapping.

</comment><comment><USER4> It's not the Israeli military that claims that, it's an Israeli seismologist that works for an oil company.

</comment><comment><USER5> > Hayoun assessed that the Beirut incident involved underground explosions. > The 43-metre (140-foot) deep crater at the port could not have been left by > the explosion of the amount of ammonium nitrate reported by Lebanese > authorities, he said: "It would have been shallower, maximum 25 or 30 > metres."

To make a claim about "maximum crater depth" seems like you'd need a lot of data about the ground composition below the storage area, and if the anfo was in a concrete silo that could amplify the blast by letting pressure build before failing etc

</comment><comment><USER6> They should also investigate how the fire started in the warehouse. Some warehouse fire setting are just arson or have business motivations like insurance fraud. In many cases they have no idea what else is stored in the warehouse and things can go really wrong.

</comment><comment><USER7> Interesting that Isreal is (maybe) capable of detecting far away fireworks bursts. I wonder how they filter out meaningless noise.

<comment><USER8> My naïve guess is that it's used to assist in triangulating where incoming rockets / mortars are fired from.

Edit: I read the article and it has nothing to do with the Iron Dome (unless it's military equipment posing as science equipment).

<comment><USER9> Also tunnels - [https://uk.reuters.com/article/uk-israel-lebanon/israel- to-b...](https://uk.reuters.com/article/uk-israel-lebanon/israel-to-build- anti-tunnel-sensor-network-along-lebanon-border-idUKKBN1ZI08C?il=0)</comment></comment></comment>


SFGate inserts a link to the story when you copy text on their site. Try it - <AUTHOR> http://www.sfgate.com/

<comment><USER2> Slightly off-topic, but I tend to highlight text as I read it, and I find it very annoying how they seem to automatically save the text snippet that you highlight whenever you highlight it. The progress bar constantly updates and it's quite distracting.

<comment><USER3> Good to know that I'm not the only one. And not only do I highlight the text, but I just keep clicking, highlighting and un-highlighting. So I'm probably really overloading their servers with the AJAX callbacks.

<comment><USER4> I do the same. The New York Times and similar sites that have actions on highlight drive me nuts.

<comment><USER5> Out of curiosity, do you (and this question is open to other compulsive selectors) tend to play with things physically when you read as well? Eg. subconsciously pick up a nearby object and start playing with it.

(I do both, and I suspect they tend to go together)

<comment><USER6> Yeah I'm the same way. I'm a compulsive highlighter and I often find myself disassembling pens or mechanical pencils, or folding paper, or removing the plastic coating inside a bottlecap, or balancing my glasses on the tip of my finger...The people I spend time with in meetings must wonder if I'm actually paying attention.

</comment></comment></comment></comment></comment><comment><USER7> It's Tynt Tracer: <http://tracer.tynt.com/>

</comment><comment><USER8> I'm not getting an inserted link. I am, however, using NoScript, and this kind of nonsense is exactly why I love that add-on.

<comment><USER3> Note that the front page (which HN links to) does NOT have this feature -- only the article pages.

</comment></comment><comment><USER9> Esquire is doing the same <http://www.esquire.com> :

<!-- Tynt Tracer Beta --> <script type="text/javascript" src="[http://tcr.tynt.com/javascripts/Tracer.js?user=aTIf7gthSr3P6...](http://tcr.tynt.com/javascripts/Tracer.js?user=aTIf7gthSr3P6Aacn9QLBk&s=70></script>); <!-- //Tynt Tracer Beta --> </div>

</comment><comment><USER10> Mac OS X, safari 4, Doesn't work. When I copy parts of a story, all I get are a couple of blank lines.

<comment><USER11> Mine is working with the same setup, are you sure you don't have any script blocking activated?

<comment><USER12> edit: You have to use CMD+C to make it work, not the mouse buttons.

</comment></comment></comment><comment><USER13> Doesn't work with Chrome either. I copy the text, I get empty lines.

<comment><USER14> hmm just tried it with Chrome on my machine and it seemed to be working, perhaps they've already updated?

</comment></comment><comment><USER15> Firefox on Linux. No link.

<comment><USER16> You also have to copy through the browser's clipboard interface, not the X11 selection. Presumably Javascript is capable of hooking the former, but not the latter.

<comment><USER15> Ah, select/middle mouse button click is the one true copy/paste. I would never have occasion to see this happen.

</comment></comment></comment><comment><USER17> Text gets scrambled when you copy. First paragraph works ok, try others. <http://www.hurriyet.com.tr/yazarlar/11403547.asp?yazarid=69>

</comment><comment><USER18> Doesn't work in Opera 10 b2 on Windows Server 2008...still, neat feature.

</comment><comment><USER19> Haven't bothered looking through the JS source, but it seems to be something bound to C-c. It only works for me on Linux when I use the main clipboard; highlight-and-middle-click doesn't do it.

</comment><comment><USER20> Mac OS X, ff3.5, Doesn't work. I just get the text. No link.

<comment><AUTHOR> Well, it works for me on FF3.5 and Linux, which is a bit more exotic, so...are you sure you have JS turned on?

</comment></comment><comment><USER21> I don't understand why this functionality angers people. It's like people don't want their information to have context...

<comment><USER5> Lots of people compulsively select text when they read, and this feature makes that distracting.

<comment><USER22> That's an argument against the "helpful" little box that pops up when you select on NYTimes ... but that's not what this is about. This is silent (until you copy/paste anyway).

<comment><USER5> I can't speak for other browsers, but in Firefox there are some brief but distracting UI changes when you select text. It is a side-effect of the click tracking code they use.

</comment></comment></comment></comment><comment><USER23> This is a great idea on their part.

<comment><USER24> Much, much, much better then the _Don't you dare link to us!_ strategy.</comment></comment>


Ask YC: Can a site copyright their Javascript source code? - <AUTHOR>

I came across some code today that I wanted to see how it worked, and even though majority of it is open source, some of it is their own and is copyrighted.
Decided to check out their terms of use
"RECOMMENDED READING grants you a limited, personal, non-exclusive and non-transferable license to use and to display and to make one copy of the Materials and to use the services, this Site solely for your personal use. Except for the license set forth in the preceding sentence above, you acknowledge and agree that you have no right to modify, edit, copy(ok), reproduce(ok), create derivative works of, reverse engineer(didn't know that), alter, enhance (also didn't know that) or in any way exploit any of the Materials in any manner. This limited license terminates automatically, without notice to you, if you breach any of these Terms. Upon termination of this limited license, you agree to immediately destroy any downloaded or printed Materials. Except as stated herein, you acknowledge that you have no right, title or interest in or to this Site, any Materials."
This is Mixx terms of use.
This question doesn't apply to them alone, but to all sites.I'm just wanted to know if copyrighting JS code is a normal thing. <comment><USER2> Any creative work is protected by copyright from the moment it is fixed in some medium (e.g., written on a napkin, saved to a computer file). JavaScript source code is no exception.

Using GPL code doesn't make my code GPL. If I violate the GPL by failing to license my derivative work under the GPL, I lose my limited (GPL) license to the original work and the original copyright holder can sue me. I am in violation of copyright, but I can fix the violation by ceasing to use GPL materials, withdrawing my derivative work from publication and/or paying damages to the copyright holder as a court may decide--I don't automatically subject my code to the GPL.

The legitimacy of "browse-wrap" license agreements itself is doubtful, and many license agreements are full of possibly unenforceable clauses. At a glance, this license would appear to forbid one person from visiting the site on two different computers or with two web browsers, since each cache would likely contain a separate copy of the code, and though IANAL I doubt that would hold up in court. More broadly, courts have sometimes held that the first sale doctrine (i.e., if you buy something, the vendor can't prevent you from selling it to someone else if you like) applies even when license agreements attempt to restrict resale (not very relevant here), and reverse engineering is also often considered legal whether the copyright holder likes it or not. See <[http://www.chillingeffects.org/reverse/faq.cgi>](http://www.chillingeffects.org/reverse/faq.cgi>).

The fact that JavaScript is distributed in source form, however, makes it harder to defend whatever you do as reverse engineering rather than just copying or creating a derivative work. It seems to me that "black box" reverse engineering is nearly always protected, but "white box" reverse engineering treads a fine line, and in most cases trying to work with someone's JavaScript would be a very, very white box.

OTOH, it's very easy to glean techniques from reading the code and apply them in ways that are unlikely to be infringing and extremely unlikely to be provably infringing. There are only so many techniques, and if you're not outright copying an implementation it's very likely that any given idiom is already common knowledge and/or available from a more friendly source. This probably goes without saying, but anything that could be done by a script or rule, such as variable name substitution or changing indentation conventions, would only produce a derivative work and wouldn't be considered original. Not that that's the limit of derivative works. Almost anything that could reasonably be regarded as a transformation or modification of the original code would probably still be a derivative work, even if it requires some creativity. Analogously, there are only so many pleasing chord progressions, so you have a lot of latitude in composing your own songs, but you can't actually distribute your own recording of Sgt. Pepper without permission--even if you change some lines and add a verse.

Runtime "enhancements" like Greasemonkey scripts or Mac OS input manager hacks are (AFAICT) completely untested in court. It is my completely unprofessional opinion that the spirit of the first sale doctrine (since you can generally dispose of your legitimate copy of a copyrighted work as you see fit) and the general esteem in which black box reverse engineering is held (such enhancements often don't require extensive knowledge of the inner workings of the code they enhance) bode well for the legality of [some kinds of] enhancements--whether the copyright holder likes it or not.

</comment><comment><USER3> Copyright, yes. This "license agreement" is another matter, and seems dubiously enforceable.

</comment><comment><USER4> IANAL (yet), but here's what I think the answer is.

1\. Yes, it's copyrightable, just like anything else that is written.

2\. But if they took any of that JS from something else that was GPL'd, then technically their JS is GPL'd too. (Assuming the GPL is enforcible.)

3\. Nothing stops you from reading their code and rewriting it yourself, so long as you don't just copy. Copyright extends to "expression," not "ideas." The way an algorithm works, the way a program is organized, the interfaces it uses: these are all ideas, not expression. So if you rewrote the algorithms in your own idiom, you could take pretty much as much inspiration from the original as you'd like.

</comment><comment><USER5> Erm.. unless otherwise specified, any code is copyrighted. That's how copyright works these days (at least in the US).

<comment><USER6> Or in any country that's signed the Berne Convention.</comment></comment>


Webtype - new @font-face service launched from Font Bureau - <AUTHOR> http://www.webtype.com/ <comment><AUTHOR> I know there are way more devs than designers here but adding a little unique typography to your web app can't hurt.

Between this and Typekit I can't wait to see new web typography take off.

<comment><USER2> _…can't hurt._

– until your type hoster is not reachable and things render funny, or if you waited for the font don't render at all. (Or you host them yourself (if legal) and your clients need to download them.)

– until you use Molengo from Google's font directory and find out the dots on the lowercase 'i' character render too far to the left on iPhones and iPads. (Why‽ What kind of stupid bug is that?)

– until you find out that some linux variants are set up with ghastly font renderers and your type looks relatively shabby for those clients.

</comment></comment><comment><USER3> I'm noticing that these fonts aren't working on the iPad. Very disappointing. Typekit has iPhone/iPad support, though it's still an experimental, opt-in feature.

</comment><comment><USER4> I already use free fonts from FontSquirrel, so I don't know what extra value they add?</comment>


Ask HN: What the fastest internet speed Larry Ellison could buy for his boat? - <AUTHOR> Let's make a few assumptions:<p>- needs to work anywhere in the world a mega yacht can travel<p>- using today's technology and infrastructure (aka no launching new satellites)<p>- focusing on raw speed, not latency<p>- combining multiple signals is not cheating<p>- price is no object, as Larry is doing this to one up his fictional buddy who has the 2nd fastest possible Internet connection <comment><USER2> He could daisy chain a squadron flying air support ships to send his packets back to the nearest fiber hub multiplexed over various mediums, eg. LIFI, 5G, a neutrino emitter, etc.

</comment><comment> alex- We can, using todays technology, use much of the electromagnetic spectrum [1] for data transmissions. Light, Radio and Microwaves.

I would assume EM regulations differ depending on the waters the boat is currently in. i.e. Internal waters or Territorial waters etc. (different RF regulations for example)

To maximise throughput we would want to consume as much of the spectrum as possible. Think broadcasting in everything; 5G bands, wifi bands, FM, AM, light, microwave links.

As you want to use todays technology; we would need to break the spectrums into chunks which we can use existing solutions on. Different parts of the spectrum will have different properties. e.g transmission distances, bandwidths, etc.

Because of the different types of broadcasts and the volume of data we would probably want a number of relay stations bridging section of the EM spectrum to a fiber optic line. Some of these stations could be very far from the boat, thousands of miles in the case of long wave RF [2].

Compression would likely play an important role also. As we don't care about latency we can take the time to send well compressed data.

I am not sure this is the kind of answer you are looking for, but the kind of wealth Larry Ellison can throw at a problem is obscene.

[1] [https://en.wikipedia.org/wiki/Electromagnetic_spectrum](https://en.wikipedia.org/wiki/Electromagnetic_spectrum) [2] [https://en.wikipedia.org/wiki/Longwave#Long_distance_recepti...](https://en.wikipedia.org/wiki/Longwave#Long_distance_reception)

</comment><comment><USER3> How about a giant container ship full of hard drives sneakernet style? :)

Largest container ship in the world: 19224 TEU (Twenty Foot Equivalent containers). Volume is about 39 meters cubed for each one. Volume of a 10TB about 392 cubic centimeters. I can fit about 99490 drives in 1 TEU. This gives me 19,125,957,600 TB of space on this giant container ship. Okay granted it might take a while for his request but it works out to be a pretty good speed.

</comment><comment><USER4> Couldn't you spool fiber behind the boat wherever it sails with a direct link into appropriate backbone, re-connecting occasionally dependent on cable length and global region.

So potentially ~1 terabit per second given current potential speeds achieved.</comment>


How does hacker news work? - <AUTHOR> How do they choose what articles to show? Is it a manual process where they keep surfing the web for recent news? <comment><USER2> Anyone is allowed to submit articles. It shows up on new, and then there's a custom algorithm that puts it in the "top of the list."

A good example is reddit.</comment>


Applied Category Theory - <AUTHOR> https://ocw.mit.edu/courses/mathematics/18-s097-applied-category-theory-january-iap-2019/index.htm <comment><USER2> If anyone is looking to get into Category Theory as a programmer, I would recommend giving Bartosz Milewski's Category Theory for Programmers a shot[0]. Quite good, and you can read it as a blog post on that site or get the ebook/physical book to leaf through.

For a more theoretical/less applied approach that's still relevant to computer science/programming, check out Benjamin Pierce's Basic Category Theory for Computer Scientists[1]. It's a very good introduction to the parts of Category Theory that are useful for [theoretical] CS, and delves into semantics of programming languages, types, and concurrency a fair amount.

[0] [https://bartoszmilewski.com/2014/10/28/category-theory- for-p...](https://bartoszmilewski.com/2014/10/28/category-theory-for- programmers-the-preface/)

[1] [https://mitpress.mit.edu/books/basic-category-theory- compute...](https://mitpress.mit.edu/books/basic-category-theory-computer- scientists)

<comment><USER3> I watched a little less than the first half of Bartosz video lectures and I still don't see what the fuss is about from the perspective of an engineer that is looking to get better at engineering.

I can't find something there that would help me implement better systems. What I do see is an attempt to shoehorn a mathematical model onto certain programming paradigms in order to be able to say that these paradigms are instances of the model. In short, a lot of talk about abstractions (or "abstract nonsense") but very little of engineering significance. Please let me know if I'm missing something by listing concrete examples of how category theory can help me with engineering problems.

Disclaimer: I'm not a mathematician.

<comment><USER4> I'd say that you can safely ignore CT until you find the need or desire to learn more. The field is still very young and it probably shines most within pure mathematics, for now at least.

I think of CT as the study of "composability" in its purest form. Mathematicians are finding that this language is really good at translating domain-specific knowledge between disparate fields, not unlike the babelfish from the Hitchhiker's Guide.

FWIW, some researchers are apparently finding interesting applications in the development of biological models. John Baez has talked about applications in this direction via control theory [0].

[0]:[https://classes.golem.ph.utexas.edu/category/2015/04/categor...](https://classes.golem.ph.utexas.edu/category/2015/04/categories_in_control.html)

<comment><USER5> Category theory studies the composition of (things that look like) functions. So each thing has a domain, and a codomain, and if we compose A --f--> B with B --g--> C then the intermediate B goes away. This doesn't sit nicely with how parallel composition works, e.g. If I talk to Google, that doesn't prevent you from talking to Google.

That's the essence of why category theory works nicely with pure functional programming, but beyond that simply fails to be useful. In particular, there has been virtually no progress in useful categorical models of parallel computation.

<comment><USER6> What about eg [http://lambda-the-ultimate.org/node/4823](http://lambda-the- ultimate.org/node/4823) ?

<comment><USER5> I don't see much / any category theory in the two papers linked. So I'm not sure what to say.

</comment></comment></comment></comment></comment></comment><comment><USER7> The course is based on this free book [http://math.mit.edu/~dspivak/teaching/sp18/7Sketches.pdf](http://math.mit.edu/~dspivak/teaching/sp18/7Sketches.pdf)

<comment><USER8> I am currently reading it, it is very nicely written and accessible. Each chapter starts off gently so you can skip to the next whenever you feel lost, only to come back later.

So far: introduction/preorders, monoidal preorders/wiring diagrams, categories/application to database schemas.

For those reading on a ebook, the book sources are available on its arxiv page [https://arxiv.org/abs/1803.05316](https://arxiv.org/abs/1803.05316) so you can build a custom pdf for your device.

</comment></comment><comment><USER9> Note.

A mathematician's idea of "applied" and a normal person's idea of the same bear little resemblance.

<comment><USER10> It may be professional deformation speaking, but they seem to be using "applied category theory" in a coherent and natural sense: they mean the theory of monoidal categories, (a) viewed as a generalization of linear algebra, and (b) omitting logic and programming language semantics as applications.

Given the centrality of linear algebra to applied mathematics (even in places where you wouldn't first expect, like the theory of regular expressions and finite automata), this seems like a perfectly sensible coinage.

(Even though I must admit I get my back up at the omission of categorical proof theory, it's perfectly natural as a sales pitch -- type theorists don't need to be convinced of the utility of category theory!)

<comment><USER11> > Given the centrality of linear algebra to applied mathematics (even in > places where you wouldn't first expect, like the theory of regular > expressions and finite automata)

Where can I read more about this?

<comment><USER12> Stephen Dolan's pearl "Fun with semirings" might be relevant:

[http://stedolan.net/research/semirings.pdf](http://stedolan.net/research/semirings.pdf)

But I would also like to know what other resources Neel has to recommend.

<comment><USER6> If you like Matlab more than Haskell, try [https://www.goodreads.com/book/show/11768822-graph- algorithm...](https://www.goodreads.com/book/show/11768822-graph-algorithms- in-the-language-of-linear-algebra)

</comment></comment></comment></comment></comment><comment><USER13> David Spivak has a company, [http://conexus.ai](http://conexus.ai), that is applying category theory to data migration as described in 7 sketches. It will soon be expanding and soliciting proposals to fund applied category theory start-ups in many domains, as well as providing some example proposal ideas. Watch [http://ventures.conexus.ai](http://ventures.conexus.ai) over the coming weeks for details.

</comment><comment><USER14> Generally, I tend to care more about math if it relates to my specific interests. I'm in ML and robotics so I've found it useful to understand algebra, topology, real analysis.

I've tried to get into Category theory a few times but couldn't keep my motivation high enough once things got too technical. Anyone know how category theory could be useful for someone in ML or robotics?

<comment><USER15> Recently, I've been into learning about CRDTs a class of data structures which can be edited independently and merged without conflicts. They can be used to build experiences similar to Google Docs (although Gdocs uses a different approach called OT).

I'm interested in learning Category/Set Theory to better understand the underlying math of how they work.

I have very little experience with ML/Robotics, but CRDTs might be useful for distributed learning, or coordination between independent robots.

<comment><USER16> What class was this if I may ask?

<comment><USER15> When I said "class", I really just meant "type".

CRDTs are relatively new so there may not be many classes yet that teach them. If you want to learn about them, I recommend you first watch this video: [https://www.youtube.com/watch?v=OOlnp2bZVRs&list=WL&index=56...](https://www.youtube.com/watch?v=OOlnp2bZVRs&list=WL&index=56&t=0s) and then read this paper: [https://pages.lip6.fr/Marc.Shapiro/papers/RR-7687.pdf](https://pages.lip6.fr/Marc.Shapiro/papers/RR-7687.pdf) . The video explains a lot of the math in a very easy to digest way and will make the paper much easier to understand.

<comment><USER16> I'm sorry, I misread. I was aware of CRDTs and I thought that they were taught in some class.

</comment></comment></comment></comment></comment><comment><USER17> What's category good for? It's a serious question so please don't say "monads", I understand monads just fine without knowing category theory. I'm down to put in the work if the reward is there.

<comment><USER18> Imagine if you took a mathematical construct and replaced all of the familiar terminology with gensyms. For example:

"A florb is brazzle of carnatious snoggles. A florb is itself a snoggle and so can be a fnizzle of another florb."

This is actually the definition of what is normally called (in English) a SET, under the following mapping of vocabulary:

florb = set

brazzle = collection

carnatious = distinct

snoggle = object

fnizzle = member

Category theory is about extracting the fundamental structure of mathematical definitions so that these kinds of equivalences can be studied with mathematical rigor.

<comment><USER19> I agree with others that this comment has increased my understanding greatly. Perhaps since this is a linguistic example, it resonates. Thank you for replying.

To add a bit of info, there is a system named Attempto Controlled English which uses a subset of Natural Language to express axioms. It is available here [https://github.com/chrisdone/ace](https://github.com/chrisdone/ace) and here [https://github.com/Attempto/APE](https://github.com/Attempto/APE)

How would one associate patterns of axioms with appropriate relations in Category Theory ?

<comment><USER18> Not a clue. I don't actually know much at all about category theory, just enough to offer up that explanation of what it's about. And I had never heard of Attempto before you mentioned it.

</comment></comment></comment></comment><comment><USER20> When I saw the title I suspect that this would be David Spivak, and happily it is, I am also please to learn that he now has a new co-conspirator in the form of Brendan Fong. I first encountered Spivak's work via Category Theory for Scientists [0] which inspired me to try to come up with ways to use it for documenting scientific protocols. My chief complaint at the time was that someone had not already implemented many of the ideas expressed in his work. Despite the usual treatment of category theory as something mystical and opaque, I find Spivak's work to bring such clarity to communicating complex ideas. Those ideas are always going to be complex, but the way we communicate about them does not have to be. From a quick skim Sketches will provide further inspiration.

0\. [http://math.mit.edu/~dspivak/teaching/sp13/CT4S.pdf](http://math.mit.edu/~dspivak/teaching/sp13/CT4S.pdf)

<comment><USER21> I've appreciated his explanation of dB schemas as categories.

</comment></comment><comment><USER22> Is there any accessible work using Category Theory that looks at API composition? I'm thinking here about data intensive systems that are often composed of different elements (e.g. Kafka, Cassandra, bespoke microservices, ...) and are glued together in an application. Could Category Theory help in getting a grip on this complexity?

<comment><USER23> [http://hackage.haskell.org/package/pipes](http://hackage.haskell.org/package/pipes) is the first that comes to mind.

And just Haskell programming in general involve composition Effects are monads and program composition is composition over kleisli arrows .

<comment><USER22> That looks very interesting and could be source of interesting ideas. Thank you.

</comment></comment></comment><comment> marquis-chacha Watched the first lecture, loved the format: start with a question that you can logically answer, then build up the math to formalize your intuition by the end of the lecture.

</comment><comment><USER24> Sort of related... but is David Spivak related to the author of that famous Calculus textbook by Michael Spivak...?

</comment><comment><USER25> Nice, now I can have sole video lectures to accompany my self printed copy of "Seven Sketches in Composability"

</comment><comment><USER26> When i was in College, my wish when learning Math is that:

\- Hey, wait! You don't tell me why we need to learn this concept

Yes, most of my lecturers use Math to teach Math. It's not useful to me, or i can't learn that way.

A wish is just a wish though.

<comment><USER27> What if the aim is to solve problems that have never been solved before? In which case, you don't know which tools you will need before. You are stuck just learning a bunch of tools and hoping you learned the correct ones.

That's how life is. Some (most) times you don't know what tools you will need in the future.

<comment><USER28> All tools were created to solve at least one problem. Explaining what that problem is, and how the tool is useful for solving it, goes a long way towards making it easy to figure out the abstract template of tool application. Going a step further and explicitly explaining why the tool works and when it doesn't is the marrow of an actual education that can be used out of context.

</comment></comment></comment><comment><USER29> Looks like a good course but nothing cringes me more than seeing the Massachusetts institute of TECHNOLOGY still using chalk boards....I mean come on now.

<comment><USER30> What better alternatives are there?

"Smart" boards — expensive, and high drawing latency makes writing on them uncomfortable. Also, text is hard to read from a distance. (They may be better for accessibility.)

Dry-erase boards — boards and markers are expensive. Markers generate a lot of waste.

Chalk — cheap, naturally occurring (and safe to dispose of) material. Easy to read at long distances.

<comment><USER31> Chalk is really nasty on your hands when you're the lecturer. And nobody ever said "like fingernails on a whiteboard" for a reason.

<comment><USER30> I don't know about you, but I always get marker on my hands when I use dry erase markers, and chalk is a hell of a lot easier to clean off than ink.

Also, don't put your fingernails on the chalkboard...?

<comment><USER31> But ink doesn't dry and erode your skin. I _hate_ the feel of chalk.</comment></comment></comment></comment></comment>


1 in 4 babies on Internet before they're born - <AUTHOR> http://www.networkworld.com/community/blog/1-4-babies-internet-theyre-born

<comment><USER2> Despite being a software developer who spends a lot of time in form of the computer screen, I think the world today is pushing the internet and computers onto kids that are too young. It would be increasingly disappointing if kids keep becoming more socially awkward in person by living on the internet. The internet has done marvels in destroying my focus and I have not been using only since the end of high school, not from 4 or 5 years of age.

Although this digital social movement is convenient it also scares me. I'll finish of with a quote from Russian a kids cartoon, "Instant messaging, allows you to communicate with others while at the same time be completely alone."</comment>


VP of Sales or VP of Marketing? - <AUTHOR>

If I'm the CEO of a startup, and I have enough money for only one of these positions (VP of Sales or VP of Marketing), which one do I hire?  And does it make sense to combine the two?  Why or why not? <comment><USER2> When starting off you can combine the two. Many startups do this. Find a person who has started his/her career in sales and eventually moved into Marketing.

<comment><USER3> I agree with this position the most. Frankly if you have a webpage, and you can articulate your product's value to customers in a simple way - you have already done half of marketing's job at a small company.

Marketing feeds sales leads, and sales is responsible changing the order of those letters from "leads" into "deals".

A salesperson without marketing needs to be able to clearly articulate your value prop, AND find new leads. This is a special person.

Another way to approach this question: Do your prospects already "get" your product, and are calling you asking for demos or more info? Or, do you need to spend the first 15 minutes of a call explaining to prospects what it is you do and why they need your product?

If it is the former - hire a sales-minded person. The hard part about sales is CLOSING. good sales people are always closing deals, and getting the money out of a customer's hands (in a good way). I find most marketer's are NOT good at closing. As long as your sales person has some leads flowing in from your site, and can figure out who is a good fit for him to hassle that turn into deals - you'll be good.

If your product is ill defined, and you need to explain it in detail or talk to engineers who "get it" before anything is ever sold, then go with someone who has a marketing mind first. Their first task is to get a very solid product story that gets people interested in your product (even if they are not an engineer). If you have a good product story, sales becomes much easier to close and will build your pipeline of deals. then you can get a sales person who is focused on closing those new deals.

Marketing and Sales should be aligned....but not run by the same person if possible.

<comment><AUTHOR> Interesting. The reason I ask is because I just saw a startup hire a VP of Sales, and they do not have a VP of Marketing.

On the other hand, we're trying to get our adoption and engagement rates of our SaaS product as high as possible before we sell anything.

It's interesting though the startups who hire a VP of Sales too early when the product has not yet been validated.

</comment></comment></comment><comment><USER4> Marketing supports sales. A VP of Sales in a startup should make her own marketing collateral.

</comment><comment><USER5> This question alarms me

</comment><comment><USER6> Hire a VP of Customer Development</comment>


Bram Cohen's "Bram's Cube" - <AUTHOR> http://bramcohen.livejournal.com/67449.html

<comment><USER2> Note that these 3d puzzles are mostly interesting just in physical form -- and not as puzzles on a computer.

In particular, 3d puzzles are not good for 2d computer displays. Moreover, 3d physical constructions are interesting when you don't understand how they work mechanically. There is no such mystery in computer form.

Having said this, I would still like to see a 3d puzzle construction set on a computer that let's you design and simulate physically plausible 3d puzzles that you can then print on a 3d printer.</comment>


Coursera Machine Learning MOOC by Andrew Ng – Python Programming Assignments - <AUTHOR> https://github.com/dibgerge/ml-coursera-python-assignments <comment><USER2> This is cool. The assignments were translated from matlab to python and they implemented submitting and grading.

That said, Andrew Ng's new deep learning course on Coursera is already taught using python, numpy,and tensorflow. The content is less math-heavy but more up to date. Anybody interested in studying machine learning should consider taking the new course instead.

<comment><USER3> The new course only teaches deep learning. His machine learning course is a totally different course (though it covers neural networks for 1 week).

</comment></comment><comment><USER4> FYI as many others have posted, there are no solutions posted here (before you get up on your high horse to decry such a thing)

This is a reimplementation of the exercises, originally in matlab/octave, into python and numpy.

The author even made the notebooks work with the Coursera grader!

</comment><comment><USER5> Thumbs done on posting the solutions. That's programming class etiquette 101. From the fact that 64 people upvoted this post, I assume I'm in for some downvotes but what's right is right.

<comment><USER6> If a free-class asks you not to do something, it's etiquette 101 to follow that.

<comment><USER7> Not if that thing goes against the more fundamental principle of sharing knowledge.

Also: copying someone's solutions is self-destructive if you want to learn something, but that's still damage you do to yourself only. The reason MOOCs care about this is because they desperately try to place themselves in the credentials game - they want their paid certificate for the free course to _mean something_ , so that you'll want to pay them. This is not obviously bad, but it's also not obviously good.

<comment><USER8> I am not sure looking at others solutions is even self destructive. That's how reading the manual, literature, open source programs work. If people didn't look at other people's solution we wouldn't get Einstein (if he didn't build on Maxwell, etc)

<comment><USER9> we are talking about basic assignments to further understanding of a well understood topic. Doing the assignment itself is critical to the educational experience of truly understanding that topic, reading a solution robs you of that

<comment><USER10> I'm glad that we share the same understanding. By any chance do you have any teaching background?

As for myself I had 8 years of industry experience, followed by 4 years of teaching, then back to industry.

<comment><USER9> never formally, but TAing in grad school and tutoring math/physics since high school has definitely given me a profound respect for teaching and helping others learn

</comment></comment></comment></comment></comment></comment></comment><comment><USER11> Posting solutions to Coursera assignments goes against the Coursera honor code.

> You may not share your solutions to homework, quizzes, or exams with anyone > else unless explicitly permitted by the instructor.

Source: [https://learner.coursera.help/hc/en- us/articles/209818863-Co...](https://learner.coursera.help/hc/en- us/articles/209818863-Coursera-Honor-Code)

<comment><USER12> These are rewrites of the solutions, from Octave to Python. As such no material rules are being broken here.

Massive props to the publisher of these. For science!

<comment><USER11> How exactly does the fact that these solutions are rewritten in python indemnify the author from this?

> You may not share your solutions to homework

Source: [https://learner.coursera.help/hc/en- us/articles/209818863-Co...](https://learner.coursera.help/hc/en- us/articles/209818863-Coursera-Honor-Code)

<comment><USER12> Rewrite mate. That's how. These are not answers, concrete solutions to the homework, to the quizzes in the designated language as they are to be submitted.

Besides that part of the honour code just sucks.

<comment><USER13> To don't share a solution goes against my ethical moral code. Sorry.

<comment><USER9> this isn't a "solution" in the sense of solving a problem that people use to build upon or share to help others not deal with that problem, rather its an essential part of the educational process of a course to derive the answers yourself to actually learn the material

there is a big difference

</comment></comment></comment></comment></comment></comment><comment><USER14> Why are the top two comments in this thread by people who didn't bother to look at the notebooks and falsely accusing the author of posting solutions?

</comment><comment><USER15> "Posting solutions to Coursera assignments goes against the Coursera honor code." I just dont get that mentality in general.

I have (had) a hard time understanding math and programming (and logic in general) from whatever resources. What I need is a problem (or task) and then the solution. At the start I will have no clue so I just check the solution. Then after some exercises I see the pattern and I "blindly" use that to solve the problems without peaking. After doing that for some time I suddenly understand the whole thing.

<comment><USER16> [https://github.com/dibgerge/ml-coursera-python- assignments/s...](https://github.com/dibgerge/ml-coursera-python- assignments/search?q=YOUR+CODE+HERE&unscoped_q=YOUR+CODE+HERE)

</comment></comment><comment><USER17> I'm very impressed they integrating with the online grader!

</comment><comment><USER10> The programming assignments are a proxy to real life problems you will encounter. In real life often there are no answers to copy from. It is also not realistic to expect the instructors to provide a unique questions for everyone. A bad actor can always pay someone for solutions.

Therefore you should approach the question with no other knowledge that is unique to the problem. Googling for how to use numPy is fine.

If you want to go around the central objective of the exercise - which is to adapt yourself to solve the problem - at the end you are only cheating yourself. You may end up with a cert of some sort, but you will definitely fail the technical interview or get outed by your colleagues for incompetence sooner or later.

<comment><USER18> Studying solutions is a valid way to learn how to solve problems. In the end, it's on the student to make sure he is not "cheating" himself.

Yeah, just copying the code and saying, "oh, hey, I know machine learning now!" isn't going to work out great. However, if you are stuck on a problem, looking at others' solutions and studying them can let you see exactly what you are missing.

</comment></comment><comment><USER19> I'm currently on week 8 of Andrew Ng's original course on machine learning. All the exercises are in Octave/Matlab. I was wondering if Octave is still widely used. I've been programming in Python almost exclusively for the past few years. I appreciate the math explanations in this course. I don't have a formal math background but it is really helping me understand what is going on. Looking forward to finishing this course then moving forward to a course specifically on deep learning.

<comment><USER11> Octave isn't widely used in industry for ML. Python is.

<comment><USER20> Andrew says in one of the video that before using python, it is recommended to get the model right first using matlab or octave.

</comment></comment></comment><comment><USER21> This raises an interesting question about MOOCs for me. Several people here are objected to violating the terms of a free online course. At what point is it ok to start creating derivative works? I've noticed many of the comments discuss etiquette or ethics "what's right is right", rather than legality. The whole question is interesting to me.

I actually do think that one of the drawbacks of Andrew Ng's course is that it uses octave rather than python. My point here isn't to kick off another debate about this topic - there have been plenty of those already. Rather, let's start with the assumption that it is _reasonable_ for someone to feel that the course is brilliant, but would be improved by the option to do the assignments in python. As it is acceptable by the terms of the site to audit the class for free (no credit is given), many people have chosen to quietly do the exercise on their own in python.

At some point, they may want to get together to share, discuss, correct, and debate their solutions - and for these discussions to happen properly, this must involve sharing code. A lot of good could emerge from something like this.

I suppose you could say "then create your own course", but that comes with some issues of its own. First, the course is a classic - it was one of most famous early MOOCs, and it is a seminal course in machine learning generally. Under certain rules, it's ok to create derivative works of art from the public domain, and it's even ok to create derivative works of art from copyrighted material, provided you follow certain restrictions and abide by a (fairly complicated, inanal) set of royalty sharing regulations.

This is just a thesis, and I'm sorting it through mentally, so I don't want to come off as pushing any particular solution or angle here... but I am leaning toward the notion that 1) original content creators for online courses need to be credited, and in some cases paid, for their work, and 2) restrictions on creating derivative works from these courses may be very harmful, especially if they get to the point where simply re-implenting things in a different language and sharing the solutions (in ways that are essential for meaningful discussion) is disallowed legally or through etiquette or custom.

Well, that's about it, I'd be interested in hearing thoughts on this.

NOTE: I do want to be clear, this is a general question prompted by this discussion - the site in question is not a place where people post and share solutions to problems for a coursera course.

</comment><comment><USER22> While I don't think that posting solutions or using them is the right thing to do I'm grateful to the author for mentioning the course — it's fantastic!

</comment><comment><USER23> Is Andrew Ng still personally teaching this course?

<comment><USER24> He's the only one listed on the instructor section.

</comment></comment><comment><USER25> i'm really new to programming and currently on my first week of a 16 week full stack web dev boot camp. as someone still wrapping their head around breaking problems into smaller chunks, would y'all recommend andrew ng's courses?

i'm coming from teaching elementary school, so my math skills aren't all that advanced :o)

<comment><USER26> I say just do your full stack program really well and stay in that track for a bit. You'll have plenty of time to learn other things after. Coding is a never ending journey!</comment></comment>


Massive fire at Concord apartment construction site: 180 units lost, $55M damage - <AUTHOR> https://www.bizjournals.com/sanfrancisco/news/2018/04/24/fire-concord-apartments-housing-development.html <comment><USER2> Under-construction apartments are a terrible situation from a fire standpoint. There's always a point in the construction where the framing is nearly complete, which results in a huge potential fire load, but yet none of the sheetrock is in place, no firewalls are in place, no standpipes are functional, etc. Generally, when an apartment complex in this vulnerable state catches fire, it results in a massive fire and a total (or near total) loss of the complex.

They're a nightmare from a firefighting POV as well, since there are often exposure problems, and even though there's no interior attack on the original fire building, there is still danger from collapsing walls, collapsing cranes (a huge crane collapsed during a similar fire in Raleigh, NC, a year or so ago), and the like.</comment>


Any tips for a newbie in app business? - <AUTHOR>

<comment><USER2> Validate it before making other marketing attempts.</comment>


Docker-powered terminals for your website - <AUTHOR> https://termible.io/ <comment><USER2> I'm curious, does writing like this actually work?

> Let's [emoji] increase your conversion rate by [emoji] reducing friction > while [emoji] delighting your users.

It reads like a really bad MLM pyramid scheme pitch and/or incredibly patronising every time I see something like that.

<comment><USER3> How would you reformulate it?

<comment><USER2> I'd just remove the emojis, but I'm curious whether they actually have an impact, negative or positive on conversion.

It "reads" to me in a really bad way, but I might be overly cynical due to exposure to things like [https://i.redd.it/9q7jj7uw2qp41.jpg](https://i.redd.it/9q7jj7uw2qp41.jpg)

<comment><USER3> I see what you mean. I don't love this style either. But here I chose the emojis as a quick & dirty alternative to something more graphical (e.g., custom icons) that would help the 3 distinct parts of the sentence stand out. I am not sure about the impact. It's a work-in-progress MVP; didn't think it would find its way to hn. Thanks for the feedback.</comment></comment></comment></comment>


Lean Startup Canvas: the wrong tool for Tech Ventures - <AUTHOR> http://www.create-build-execute.com/2014/07/28/lean-startup-canvas-the-wrong-tool/

<comment><USER2> a canvas helps to structure ideas and directions. the canvas is just a snapshot of a product, and there are a number of different canvasses out there. for example, the pain/gains/job canvas, which I tried to apply to freelance projects: [http://thinkingonthinking.com/customers- jobs/](http://thinkingonthinking.com/customers-jobs/) \- what could be wrong with this?</comment>


What the Heck Is Twitter?  It's not a Google killer, and it's not a Facebook killer. - <AUTHOR> http://www.slate.com/id/2213036/

<comment><USER2> It's a new protocol for nondeterministic messaging.</comment>


Punkbit – a slick Hacker News reader - <AUTHOR> http://hackernewsreader.punkbit.com/ <comment><USER2> This is a brand new name obviously made just to post this with the original title of 'wow this is a cool hacked news reader'. This is some side project and it is somewhere between a demo and total nonsense.

It had a title that seems to assume people can't tell when someone didn't 'just find' a page and are trying to pretend they aren't trying to promote their own stuff.

<comment><USER3> It's also equally likely this is someone who has lurked on HN for a long time and after making this decided to finally make an account so they could share it, and didn't know the etiquette around using "Show HN" versus just posting the site.

Hanlon's Razor: Never attribute to malice that which can be adequately explained by [ignorance].

Wheaton's Law: Don't be a dick.

<comment><USER4> Just found out that my sister posted this. This wasn't supposed to be shared and no, I didn't in any form or shape tried to promote any work, etc. Or pretend to be somebody else. The project was an experiment and was created as a code challenge after an interview. and design or whatsoever was not a requirement. So decided to take the time to experiment and in any way was my decision to use the hacker news api. Also just worked on it for a few hours to have something to show to the company and no other intention than that. Thanks for insulting me, nice of you!

</comment></comment></comment><comment><USER5> I see a big Y, a small (scroll?) animation, the rest is WSOD</comment>


FCC is still editing the net neutrality repeal order - <AUTHOR> https://arstechnica.com/tech-policy/2018/01/ajit-pais-fcc-is-still-editing-the-net-neutrality-repeal-order/ <comment><USER2> This is an interesting read:

[http://transition.fcc.gov/Daily_Releases/Daily_Business/2017...](http://transition.fcc.gov/Daily_Releases/Daily_Business/2017/db1214/DOC-348261A4.pdf)

Specifically, I think it makes much more sense from a technical and consumer perspective for an internet connection to be classified as a Title II common carrier than a Title I information service.

Technically, it's a network connection that can carry data. Information services, classified as "making available information via telecommunications," sounds much more like a broadcast service than a bidirectional network connection.

From a consumer perspective, and in my experience, we are always better off with unfettered access to a connection, whether it be electricity, water, or internet connectivity, rather than the programming on that connection, for example cable television.

Also:

> I, for one, see great value in the prioritization of telemedicine and > autonomous car technology over cat videos, benefits I anticipate the House > Hearing will highlight.

Again, that's not really how the internet has traditionally worked, and I'm not sure we really want content-based prioritization, outside of existing QoS standards that aren't guaranteed across public internet connections. There's no reason QoS definitions couldn't be reviewed to re-prioritize specific IoT or autonomy protocols, but I don't see how the FCC should be making content decisions for consumers of internet bandwidth.

<comment><USER3> This argument has been going on for 20-30 years.

See: Netheads vs Bellheads. [https://www.wired.com/1996/10/atm-3/](https://www.wired.com/1996/10/atm-3/)

The cat video example was chosen very deliberately and isn't a frivolous statement. Telcos want to distinguish between telemedicine and cat videos for a good reason — the requirements for delivering both are the same, but insurance companies have money, and the telco will have a higher tariff for "important" things like telemedicine.

Look at a company like Verizon. They are literally allowing billions of dollars of valuable assets (the POTS network) rot and have shed millions of customers with a high margin service. Some states (like NY) offered them billions of dollars of matching funds for capital investments. Verizon told them to fuck off.

Why? Verizon isn't dumb. They know the politicians have no appetite for big Federal government investments in infrastructure, and isn't going to for decades. They know that there's more money to be made being toll takers, and as the internet players consolidate, there is plenty of cream to skim. 5% of Facebook or Google or Amazon is an unimaginable fortune, and they could eventually get the hands in that till.

<comment><USER4> So do you think they have strategies or technologies already in place to categorize traffic based on specific content types, eg DPI of some sort with machine learning? Or do you believe it will just be a sort of gateway tariff, eg hitting Google or Amazon? Do you think their next move will be to try and fight encryption?

Also, and perhaps most importantly, if the controllers of the last mile are to get their hands in this till, do you think they have the engineering prowess to do all of this and put together a _robust_ infrastructure? Or will we end up with Clown Car Internet in most areas of the US?

<comment><USER3> Yes, they do. Encryption doesn't matter.

On wireless service, all traffic is proxied and they do assessments of the apps based on a number of metrics. I saw one case that was based on number of packets sent. That was five years ago —- they have the tech chops to do it.

Remember that with consolidation, it's much easier. THe carriers could handle most internet traffic with this type of scheme by making deals with AWS, Azure, Google, FB, Netflix, etc.

</comment></comment></comment></comment><comment><USER5> Anybody know what the basis is for the threatened lawsuits?</comment>


Learn to code: This is the future. My thoughts - <AUTHOR> http://cyberomin.github.io/tech/2016/08/13/learn-to-code.html. <comment><USER2> Interesting how the author was asked for software engineers and not coders. In software engineer the emphasis is on engineer.

Coding is easily picked up skill that generates marginal value.</comment>