Patoline: A modern digital typesetting system - <AUTHOR> http://patoline.org/ <comment><USER2> I'm very glad people are doing this. The local maximum created by TeX (and its surroundings), while producing impressive output, has kept many people from developing any typesetting software. It was usually easier to learn how to trick TeX into doing what you wanted, or build yet another overlay on top of it.

A similar local maximum exists with Emacs (you might also call it a local energy minimum, as it requires less energy to hack Emacs into doing what you want than to write a whole new system). This has also held back editor development for years (if not decades), but recently we started seeing attempts at breaking out (LightTable is one example).

This is an interesting phenomenon: neither TeX nor Emacs are bad, in fact they are both impressive pieces of software. But we could do better now, and yet we usually don't even start, because it is such a daunting task, and it is easier to extend existing solutions.

Best of luck to authors and contributors to this project!

<comment><USER3> Your emacs analogy has issues -- vim is another programmable editor alongside emacs. And IDEs, especially ones like Eclipse, have similar complexity behind a graphical interface. Should languages be replaced, or is it better that they just grow and adapt? Look at the scale of the energy minimum around English.

<comment><USER4> The communities that back vim and emacs would never allow for evolution in the direction of light table or any of the other reinvent IDE projects; heck, they can't break out of their terminal/ASCII mindset for the most part. Technologically they could, but the community has bought into a certain set of principles that work well but don't allow for much deviation. So new projects come along and deviate from entrenched principles, sometimes in successful ways.

English is quite different, it changes with time and even place.

<comment><USER5> Terminal as a first level interface is not a vim mindset. It's a use case. The primary use case.

</comment></comment></comment></comment><comment><USER6> The about page gives me no idea of what it is, especially as someone who knows TeX quite well. It starts with the single mistake all of those pages do: "It's like A, but with B!" On top of that, B is already in A. Typesetting with scripting? LuaTex (actually quite easy, if you know the typesetting surroundings). More layout control? ConTeXt.

The biggest hurdle in all those systems is understanding what typesetting actually is (in contrast to content editing or especially programming). It comes with a completely different vocabulary. What's a strut?[1] What's a quad?[2] What are the standard elements of typography and page layout? How are fonts measured?

Finally: how does the system manage forward compatibility (can I still compile my document from 5 years ago?) - scripting and modularity are features that have to be evaluated under all those regards.

Also, I am very surprised that code examples in the reference documentation look horrible. Isn't that what the system is there for?

That said: I love that there is competition in that space. TeX is great and will be around for a few decades, but that doesn't mean there can't be others.

[1] [http://en.wikipedia.org/wiki/Strut_%28typesetting%29](http://en.wikipedia.org/wiki/Strut_%28typesetting%29) [2] [http://en.wikipedia.org/wiki/Quad_%28typography%29](http://en.wikipedia.org/wiki/Quad_%28typography%29)

<comment><USER7> > Can I still compile my document from 5 years ago?

Well on the About page it does have the FAQ:

> Can I use Patoline for a huge, ten years long project that I'm starting now?

> Although one of the authors has written his PhD. thesis (120 pages, in > computer science) with it, we don't recommend it now. The reason for this is > that small adjustements and bugfixes are being made all the time, and > working on such an unstable system can be frustrating. However, for > documents that are not meant to last forever in time, we would be happy to > help you with it: feel free to contact us for help.

> Stay tuned: we do plan to release a long term supported version of Patoline > soon.

<comment><USER6> This was an example question.

The problem is wide, that's why I was asking about _forward compatibility_. Even if I have long term support, what happens if that runs out? How does that work in the presence of scripting and extensions?

TeX has a whole culture around that - even if there are no long term releases, it is _very stable_.

For example, the LPPL even prohibited releasing changed files under the same name for a long time!

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

</comment></comment></comment><comment><USER8> It uses the same archaic syntax as TeX :( I was hoping they would come up with something nice and modern like Markdown.

It seems like a cool project, OCaml is probably a fine choice although I've never used it. But there are a few smells. The first to me was him mentioning the project had 100.000 lines already. Now if this was C I could see why. But this is a modern functional language. There's no 10.000 line rolled out parsers, no hundreds of specialised general libraries.

Why is the project 100k lines? Is it an unmaintainable behemoth already?

<comment><USER9> a) markdown isn't expressive enough. In fact it's pretty horrendous to edit and separate content and layout IMHO. I'd go as far to say I prefer docbook over markdown. It's fine for github readme's but not typesetting.

b) the problem is complicated. Complicated problems need lots of lines of code. 100kloc isn't much. The thing I'm working on has 5.2Mloc and took 25 people 20 years to write. To the layman it probably looks like it does less than this typesetter meaning it's a bad metric to use.

My MacTeX installation is about 1300Mb if that's any gauge.

<comment><USER10> Or, it could be that TeX has been cobbled together over decades with little design guidance or vision, resulting in a mishmash of approaches and inefficient code.

To me almost everything in TeX feels like a hack, even if the fundamental idea is good and the sum of all hacks ends up looking pretty good. The fact that it's a huge hack that takes 1.3GBs to install is not a gauge of quality.

<comment><USER6> The full TeXLive is 1.3GB large, because it ensures that the only thing you need to build any semi-sane TeX document is this installation.

Describing TeX as Code misses the topic by a wide margin, a lot of the things in the distribution are fonts and compiled versions of the documentation.

Bash the idea of treating TeX as code out of your head and you will find it quite a bit saner.

<comment><USER10> I don't think anything will ever convince me Tex is a sane design. For instance, this SO on trying to set a5 paper size:

[https://tex.stackexchange.com/questions/22917/a5paper- settin...](https://tex.stackexchange.com/questions/22917/a5paper-setting-not- taking-effect)

(If you thought setting a5paper would result in your output paper size being A5, think again. _facepalm_ )

</comment></comment></comment></comment></comment><comment><USER11> To quote Knuth [1] describing TeX "Think thrice before extending," because that may save a lot of work, and it will also keep incompatible extensions of TeX from proliferating.

Personally, I am of the opinion that the original TeX was well 'modularized' in 'Pascal Procedures' [1], being Turing complete, extensions such as the LaTeX format and the countless of packages after that helped it survive and prosper. Think of a macro that you define as an easier way than programming a module in JavaScript and it doesn't need a half a dozen tools to set it up.

        \def\#1{\TeX\ is alive says #1.}

Nevertheless, provided the lessons learned are incorporated I applaud any new initiatives in more modern languages. Whatever is produced will however, need to be able to parse TeX, otherwise it will not be easily adopted by the community.

[1] [http://www.tug.org/texlive//devsrc/Master/texmf- dist/doc/gen...](http://www.tug.org/texlive//devsrc/Master/texmf- dist/doc/generic/knuth/tex/tex.pdf)

<comment><USER12> > Whatever is produced will however, need to be able to parse TeX, otherwise > it will not be easily adopted by the community.

This is a huge barrier to raise, since _parsing_ TeX is the same as _typesetting_ TeX—the meaning of a macro later on can be affected by a macro now. You can't even just execute the macros in a vacuum, since the meaning of a macro can depend on things like the current page number.

</comment></comment><comment><USER13> The insight (made here by jwr) that TeX and Emacs and Vim are local maximums is a great observation that explains why we are stuck with these three programs. I've used these programs for over a quarter of a century and often wished for shiny, new replacements. Younger HN readers may not realize just how old these programs are.

How in the world did Bill Joy come up with Vi in 1976? It lives on today as the velociraptor of editors, Bram Moolenaar's Vim. I use the T. Rex of editors, Stallman's Gnu Emacs, another dinosaur of software, yet unsurpassed in scope and capability. These are great at what they do and so flexible and extensible that it's difficult for any new project to catch up.

TeX is different. Knuth, one of the greatest computer scientists of all time, created TeX. His choices for development tools were meager, but with the help of /literate programming/, essentially invented by Knuth to write TeX, he wrote TeX using the Pascal programming language in the late 1970s.

TeX, like Emacs and Vi/Vim, has an extension language. TeX has a powerful macro system that allows it to be extended. LaTeX is a set of TeX macros that most users use to create documents. The number of macro packages written for TeX to support every imaginable kind of typesetting (chess notation and boards, music, etc.) is staggering. This accounts for the large size of TeX installations. One can easily download and install every package ever available and be ready to typeset anything. The core TeX program, however, is composed of 1376 extremely well documented paragraphs (small code fragments). It is a pleasure to read through Knuth's literate code, all available as a beautiful book (naturally typeset in TeX).

The features of TeX were effectively frozen in 1985. Knuth kept track of every error in TeX during its development. Since 1985 there have been less than 100 errors found in TeX [1].

The open-source communities around TeX (and Emacs and Vim) make it is difficult for any new project to develop the features that make it worth switching. This is the uphill climb that is facing Patoline. Will it succeed? I'm not sure because many others have tried and failed. Lout was a really good attempt [2], but it seems to have lost steam [3].

[1] [http://texdoc.net/texmf- dist/doc/generic/knuth/errata/errorl...](http://texdoc.net/texmf- dist/doc/generic/knuth/errata/errorlog.pdf) [2] [http://en.wikipedia.org/wiki/Lout_(software)](http://en.wikipedia.org/wiki/Lout_\(software\)) [3] [https://www.ohloh.net/p/lout](https://www.ohloh.net/p/lout)

<comment><USER14> I would argue it's not so much the community (I'll bet there are maybe a dozen people who understand the source well enough to improve it) so much as the fact that TeX is feature complete, essentially bug free, and written by a genius. It really is an amazing piece of software which has no equal, even if you wanted to spend thousands of dollars. Why are we intent on replacing it again? I understand the gripes about the language, the error messages, and so forth. So design something that compiles down to TeX, not unlike what the Java(Script) people have done. Reinventing TeX just seems like an exercise in futility. (Nice duck logo though.)

<comment><USER15> The duck is a (mistaken) interpretation of an early French automaton: [https://en.wikipedia.org/wiki/Digesting_Duck](https://en.wikipedia.org/wiki/Digesting_Duck)

</comment></comment></comment><comment><USER16> I'd recommend adding some more information on the index page. When I arrived I tried to scroll down hoping to find out what this is about, but instead I had to go to the 'about' page myself.

Then I tried to read the 'about' page but the text is very small and the lines very long, so it's hard to scan for relevant information. The bullet points make a couple of claims about what Patoline excels at, but still no code examples can be seen that could give me a feel for how Patoline actually works.

I had to go to 'documentation' and click a small insignificant looking link to actually get to see an explanation of Patoline and some code examples... in a PDF file.

I understand that it's cool to write the tool's manual using the tool itself, but if I come to the website and want to evaluate quickly whether this is interesting and could replace LaTeX for me, I need a quick overview directly on the index page, together with some examples similar to the one on the wikipedia LaTeX page ([http://en.wikipedia.org/wiki/LaTeX#Examples](http://en.wikipedia.org/wiki/LaTeX#Examples)).

<comment><USER6> It's not only cool, the documentation is the primary test case for many of those projects.

</comment></comment><comment><USER17> Using OCaml and darcs won't help this project to find contributors outside French academic world. It's unfortunate, IMHO.

</comment><comment><USER18> Will it work sanely with Make, handle modular documents better than TeX, etc? The biggest frustration with me and TeX isn't the quality of its output or its extendability, it's simply difficult for me to work it into a reproducible workflow without a lot of effort on my part.

With all of my tools that I use that somehow depend on each other I can always glue together the results of my work with one tool to the input of another tool via Make, minimizing human error in translating results over myself, but LaTeX (combined with tools like BibTeX) somehow always breaks this model, which can be very frustrating since LaTeX is such an important component of mathematics research.

</comment><comment><USER19> It's going to take da Vinci like talent and a herculean effort and to build anything 10% as good a TeX. Knuth, the pre-eminent computer scientist, devoted 10 years of his life to type setting to create MetaFont and TeX. Being able to "write scripts" for it ain't enough. Anyway... prove me wrong.

<comment><USER20> A lot of that time went into the development of not the code per se, but algorithms that newer code could reimplement. Perhaps in simpler forms on newer machines. Conventional TeX has a hard time optimizing placement of page breaks because its data structures hold only one page at a time, and discard its contents before starting the next, due to memory limitations of computers from the 1980s. Those limits no longer apply, which could make it a lot easier to code strategies for eliminating "widows" and "orphans" \-- situetions in which only one line of a paragraph is stuck at the top or bottom of a page.

</comment></comment><comment><USER4> I think if someone was to redo TeX, that it would be really nice to see an incremental type setting system. That means modularity not just at the code level, but also with respect to how the run-time data structures are dependent on each other, and the ability to "reflow" text on a change in a way that required minimal changes to the previous flow of the text. Then we could have something that was Wysiwyg, interactive, and produced output that looked fairly decent.

<comment><USER6> "Fairly decent" is a fairly low bar for a typesetting system.

<comment><USER4> Ok, at least as good as TeX then, something much better than Word. I mean, we are getting good with doing incremental computation (e.g. FRP, SAC, etc...), why not apply these techs to the problem of typesetting.

</comment></comment></comment><comment><USER21> Hm. The rendered patobook.pdf documentation wouldn't display in the browser; after downloading and opening it in Acrobat Reader, it said some embedded font couldn't be loaded completely, I guess all monospace formatted text was lost: see screenshot at [http://i.imgur.com/MhkPqRR.png](http://i.imgur.com/MhkPqRR.png)

I'm very glad to see this project happen but this wasn't a good first impression.

<comment><USER22> Seemed to work fine for me in Chrome on Windows.

</comment></comment><comment><USER23> Is "line" in this pronounced as in "gasoline" (lin) or "waistline" (laɪn) or "adrenaline" (lɪn)?

edit: Like gasoline. "Its name is to be pronounced like Pa-toe-leen, and it is the frenchifcation of the translation in portuguese of a joke in english"

<comment><USER24> I'm pretty sure the pronunciation comes from Count Duckula's translation to Spanish.

Listen to the first 5 seconds of this video: [https://www.youtube.com/watch?v=5AR58I40_Os](https://www.youtube.com/watch?v=5AR58I40_Os)

That's how you pronounce it.

</comment></comment><comment><USER25> I was ready to like this, but I ran into a lot of problems installing camlimages on os x. Anyone else? I'll keep working on it later.

</comment><comment><USER26> Interesting approach. Even though as for a replacement for TeX, I always expected Lout[1] to gain popularity. I haven't used it in years, but I remember being really easy to learn and way lighter than TeX.

[1]: [http://en.wikipedia.org/wiki/Lout_%28software%29](http://en.wikipedia.org/wiki/Lout_%28software%29)

</comment><comment><USER27> Folks, stop trying to solve problems that have already been solved. Especially if it was Don Knuth who solved it. When that guy solves something, it _stays_ solved.

In this case, you're up against something Don Knuth solved and then Leslie Lamport made more useable. You really want to compete with those two?

<comment><USER28> It's a mistake to think we can't improve on something because someone smart built it. In my academic community, everyone fights with LaTeX and I can only say with confidence that one person I know has mastered it. Everyone else just hacks at their document until it's close enough.

<comment><USER29> That could also describe the process by which the majority of computer code is written when you consider everything that involves coding these days. The situation is not likely to change with new tools.

</comment></comment></comment><comment><USER30> Thanks for your interest in our project, that hasn't released any version 0.1 in three years, and yet manages to concentrate a lot of (maybe necessary) love and hate.

First, about the technical points:

\- Ocaml has been backward compatible for the last 20 years, which is why we rely on it for backward/forward compatibility. After some time, we obviously hope to release a forward compatible version of Patoline. As a side note, I've got several papers written in LaTeX on my hard drive, that don't compile anymore after only eight years.

I imagine that debugging and improving packages written in TeX is hard enough that authors who manage to do it do not bother about compatibility. With the exception, of course of those "who know TeX and LaTeX pretty well" (at least until the day they write their first package, like I did shortly before beginning Patoline).

Moreover, there is something called "a type system" that OCaml uses, that makes your code more likely that any other non-functional language to remain stable through time. I know there are people who do not acknowledge the existence of this, and confuse it with older systems such as type checking in C, or who believe functional programming is a parenthesis writing competition. I would like not to use the kind of authority arguments I've seen in this page to convince you. Trying ocaml or haskell is a good way, but you need to be willing to be convinced, which is usually not the case in this kind of discussions. At least it makes sure that the program cannot run into an "undefined behavior" without the author being aware of it, something that my own daily experience with programs such as svg2tex does not do.

\- In our first project meeting about Patoline, it was decided to _not_ choose a definitive language. This is probably the only design choice. Of course there is a default one (intended to be forward compatible, if you are still following), but you can change it. Like markdown? Write a compiler to Ocaml, it should not take more than a couple of hours, and you won't have to rewrite 20000 lines of code to handle the crappy font formats that Microsoft, Apple and Adobe have designed for you, nor 3000 to output reasonably portable PDF documents that most printers can print (maybe this is an explanation of the size).

\- Knowing quads, struts, \expandafter and \futurelet is cool knowledge. Did you also known that TeX uses its own fixed-point algebra? While these are certainly "inventions of a genius", using 21st century numerical methods to adjust spaces is efficient use of science and technology, and that's what we do. By the way, have you heard of IEEE-754? It doesn't begin with a slash, I've seen it used at Caltech, probably Stanford knows about it too.

Now about other points:

\- What is "feature-completeness"? I know "Turing-completeness", which is the ability to simulate any Turing machine. On the operating systems we have today, "Turing^OS-completeness" (the ability to simulate any Turing machine with the OS as an oracle) is probably a great feature too. This is something Patoline has, that TeX doesn't. Querying online bibliographic databases in Patoline is a matter of writing a few lines of OCaml. In TeX, it means writing pascal code, for a variant of pascal that can talk to the OS (web2c probably can, I'm sure, although it was not written by a genius).

\- We also seek to provide a development platform for new typesetting algorithm. While Knuth may be regarded as "the man who invented dynamic programming", he was ten years old when Bellman discovered it. Today, we have other methods, such as approximation algorithms. We could even imagine learning good typographic choice using methods from machine learning. There is space for innovation on this planet, and although I use emacs and vim, and even pdflatex on a daily basis, I do not consider them a full stop to software.

<comment><USER6> While this is half an answer to my post, I am incredibly put off by the tone and will not take a second look at your project.

Yes, I know what a modern type system is and what merits it has. I also know that TeX has it's own fixed point math. But I am not convinced by your product either and this is certainly not helping. I do also now know that one of the authors is incredibly snobbish about his product, which I have a strong aversion against. And this is where I'll stop.

<comment><USER30> You're right, but then if your point was to start a discussion, maybe the best way to do it was not to start looking down at our project and assume that we are total ignorants who worked five years on something without any idea of what we were doing or what others did before.

Your first comments were really offensive, but I recognize that the tone of my post also reflected the 95% of negativity in the comments I've heard since we started it, the vast majority of them without even looking at what we're trying to do (we've even had comments like "stop using your favorite text editor / version control system / operating system and use mine instead"!).

What was your point in trying to destroy an embryo project? Didn't you expect such a reaction from their parents?

<comment><USER6> I think I see where this went of track and I think this is a grave misunderstanding.

"The biggest hurdle in all those systems is understanding what typesetting actually is"

Read it as:

"The biggest hurdle in all those systems (for the user) is understanding what typesetting actually is"

Many programmers approach TeX (and patoline?) as programming environments like programming languages. They are not, even if they allow to build new components (maybe using scripts). I wanted to illustrate the challenges from that perspective.

I did not want to fundamentally criticize your ability to tackle those problems or imply that patoline is not fitting to those problems. My biggest problem was that the About page gave me no idea about your system as a typesetting system, only as a programming environment and some of that gives me a bit of a headache. This is by the way shared with many other projects, my pet peeve is a programming language that mentions it's own name only once on the About page and Haskell thrice ;). Be more self-centric! What is patoline, not compared to TeX?

If you read anything else out of that - I am sorry for phrasing that wrong.

Still, as a maintainer of a software that is often criticized in similar fashions (we build a web framework in Ruby that is not Rails), I would recommend to take the criticism as a less emotional matter. Software is rarely our actual baby and it often helps more to just discuss the actual points of the criticism or check whether there is a misunderstanding (this, in this instance, also applies to me).

As a final word: Sorry for what came out of that. I understand your frustration and that you needed to write it off your chest. My reaction was a bit knee-jerk as well.

<comment><USER30> Oooooh! Ok, my mistake, sorry for the misunderstanding too.

I agree that we should reformulate the website, that was written two years ago now. I'll try to do something, given all the comments on this discussion, including yours and others'.

<comment><USER6> Great! Feel free to ping me on twitter, same username, when you have something. I'd really like to see it.

Happy that this is settled, too.

</comment></comment></comment></comment></comment></comment><comment><USER31> I am still not clear what the output format is - is it a set of html pages that can be hosted on a server? A compiler produces a binary and the binary generates document(s)?

I am looking for an authoring tool where I can create the text of a tutorial but have Bret Victor like sections of interactiveness that illustrate the details of the text. The end format would be a set of web pages. I could code it all up with html+javascript+backend but I am wondering if there is an existing tool to do all this (some sort of task specific editor).

<comment><USER32> There's R Markdown: [http://rmarkdown.rstudio.com/authoring_shiny.html](http://rmarkdown.rstudio.com/authoring_shiny.html)

(Found about this today because someone requested R Markdown support in [vim- pandoc]([https://github.com/vim-pandoc/vim-pandoc/](https://github.com/vim- pandoc/vim-pandoc/)), which I manage. The result was [vim- rmarkdown]([https://github.com/vim-pandoc/vim- rmarkdown/)](https://github.com/vim-pandoc/vim-rmarkdown/\)))

</comment></comment><comment><USER10> It's about time someone gave this a bash - though to some extent this covers the same ground a Pandoc.

However, some of the technological choices seem... unwise if the aim is a lively community project. Version control for instance - whatever technical advantages Darcs may have are heavily outweighed by it's much smaller user base (having to learn a new VCS just to contribute to a project is a massive pain!)

</comment><comment><USER33> What are the advantages of this over TeX/LaTeX? I already know LaTeX quite well as will most people who are looking for a typesetting system.

<comment> a-nikolaev It seems, Patoline's syntax resembles LaTeX syntax a lot, but it lets you embed code more easily. And you can use OCaml or some it's subset instead of TeX's \if, \loop, etc [1], which is probably a good thing.

       \begin{genumerate}(AlphaLower, fun s -> [tT (s^". ")])
         \item First item
         \item Second item
       \end{genumerate}

Which produces:

       a. First item
       b. Second item

[1] [http://en.wikibooks.org/wiki/LaTeX/Plain_TeX#Conditionals](http://en.wikibooks.org/wiki/LaTeX/Plain_TeX#Conditionals)

</comment></comment><comment><USER34> I find it ironic that a website for a typesetting tool requires me to zoom in to be able to comfortably read it.

It looks like it could be an improvement over TeX. I like that modularity is a focus, because that's where TeX really suffers. Hopefully the typographical elements will actually be composable and extendable rather than having the loose facade of such functionality found in TeX.

</comment><comment><USER35> > The new typesetting algorithms of Patoline places your figures at an optimal > position decided by the author, not by the system. It can optimize your > document in several ways, including reducing its size to fit the standards > of a conference paper.

I guess this means you could use this to force a résumé to fit on one page!

</comment><comment><USER36> I haven't any input on the actual product - it's not something I have a need for but spell check the site! The about page is full of mistakes.

> ...powerful tools that have been developped to process languages...

I assume the author is French from the mistakes, just run it through an english spellcheck platform.

</comment><comment><USER37> Interesting, it'd be nice if it was available on homebrew and not just macports though.

</comment><comment><USER38> It'd be nice to see this working in Authorea as well: [https://www.authorea.com/](https://www.authorea.com/) Have you had any luck rendering Patoline to HTML5? Via Pandoc?

</comment><comment><USER39> What's wrong with their web page? The font they picked looks terrible on both Chrome and Firefox, even when zoomed.

<comment><USER40> It's Alegreya, and I find it quite beautiful.

Quoting Google fonts[0]: 'Alegreya was chosen as one of 53 "Fonts of the Decade" at the ATypI Letter2 competition in September 2011, and one of the top 14 text type systems. It was also selected in the 2nd Bienal Iberoamericana de Diseño, competition held in Madrid in 2010."'

Maybe your font rendering is broken somehow?

[0]: [http://www.google.com/fonts/specimen/Alegreya](http://www.google.com/fonts/specimen/Alegreya)

</comment></comment><comment><USER41> It's great to see this here. I meant to try out patoline over a year ago but it wasn't quite ready. This prompts me to take another look. I do remember the devs being very approachable and helpful (which is big plus for me).

I'd encourage the devs to put this in OPAM proper though. Having to add a remote seems like unnecessary friction. Having said that, it's not clear from the site what the current release is.</comment>


Show HN: Internet Leaderboard, see what's winning the game of likes - <AUTHOR> https://www.internetleaderboard.com/ <comment><USER2> Allow filtering by category and lists and this could be a winner. eg I am utterly uninterested in music videos but maybe I love comedy, or I don't care about celebrities but I am interested in news.

<comment><AUTHOR> Thank you :) fair point. I'll add filtering by domain, and then maybe by hash tags. Though it might be tricky to identify the category across different sites.</comment></comment>


Show HN: I made my first product demo video - <AUTHOR> I'm a Product Designer for Nudge Rewards in Toronto and have created my first product demo. From Sketch, to Origami, to Final Cut Pro and everything in between. Anyon e willing to take a quick look and give me feedback?
Demo Video: https://www.youtube.com/watch?v=o-KB_MkvhPk <comment><USER2> Overall I like it, good music pick, pretty decent pace, but the editing and cuts lead to a fractured feeling.

* "Meet Nudge Rewards" can cut to the iphone screen, but it'd be nice to throw in a zoom onto your logo there, as "Meet" seems like a verb where you wanna introduce your branding quite prominently. If the logo zoom situation ain't great, I'd use a shot of tapping on the icon and cut out after a second or two of showing the app's loading screen just to get more visible branding.

• Instead of animating each new word in, use that animation for emphasis. It's jarring as is, and hard to read, and definitely contributes to the sense of the video being fractured.

• I'd combine the "facitilate conversation and collaboration" with "In real time", and letting that demo run unbroken.

<comment><AUTHOR> Thanks a lot @andkon...that's some terrific insight; my weakest area is storytelling and with my next video I'm hoping to round off all of the corners to showcase the branding quite prominently and making the video easier to digest.

</comment></comment><comment><USER3> Way to much going on, too much text in the screenshots so I try to read it but then it's gone.

The text doesn't pop with the beat, nothing big bug kinda odd feeling imo.

At the end I don't really get what the app is about, some news thing within the company. And/or some performance tracking for each employee.

And the iOS wallpaper is like iOS 8 style.

As a whole, I think you have the style and feel down pretty well (not very original though) you just need to simplify it a bit.

</comment><comment><USER4> Thanks for sharing, I also want to make such videos, so I have watched the whole video, and feel that it's too fast comparing to those videos I watch before. Too many texts for audience to read, and they are so small.

More important, I do not get any key idea from the video. Maybe I am not the expected audience of the product.

</comment><comment><USER5> Congrats! I know how much work this whole process is when you have never done it before. I'd recommend looking into doing your animations manually rather than a screen recording to get rid of the magnifying glass "finger" thing</comment>


Aphantasia: A life without mental images - <AUTHOR> http://www.bbc.com/news/health-34039054?ref=hn <comment><USER2> Wow, I finally have a word to describe my mental experience. To others, I've described the vividness of my memory as like a wireframe. I can _feel_ spatial relationships but I don't see them like a picture in my head. There are occasions that I can see color in my minds eye, but it's mostly greyscale.

<comment><USER3> How do you dream?

<comment><USER4> Rarely, if ever, and never as images. If your dreams are like movies, mine are like stumbling through a dark house.

<comment><USER3> @cottonseed, @sall, @x3n

How do you remember faces or your house, or your car?

<comment><USER5> This is not about memory, it is about what you can access consciously. Those of us who have no image in our minds have memories of our houses, cars, friends, etc. just like you do (as far as I know!), they are just not part of our conscious experience. If you want to relate to this, think of language processing: you are not aware of how your brain parses the sentences you hear, though you still have access to the meaning that is produced by that parsing. We don't have access to the visual images, but they are there somewhere and can be used by our memory system. (ps. I suspect that getting images to reach consciousness or not is not just a random 'accident', but rather reflects a more generally different brain organisation -- just not wrt memory having access to visual representations or not)

</comment></comment></comment></comment></comment><comment><USER6> I think I have a mild version of this. I can picture things, but it generally takes a fair bit of effort and concentration to get decent detail if the thing is complex, and it's a fleeting image. Especially picturing people's faces is difficult. I can get like.. an idea of the person's face, so I know I'd recognize it if I saw it, but I rarely see a picture of their face in my head.

I do have normal visual dreams though, which apparently many people with full- on Aphantasia don't. And I can picture and manipulate geometric objects in my head, that kind of thing.

Again, I guess it's mostly that my mental images tend to be vague and indistinct. I really wasn't aware that some (apparently most!) people see perfectly clear mental photographs of things. Now I'm trying to figure out how I haven't noticed the lack of this ability more! It seems pretty significant.

<comment><USER7> Your self-description sounds entirely typical to me. I don't think most people can imagine detailed photographic images (e.g. of faces), though there do seem to be some who can, like certain autistic savants.

It seems likely that people's external verbalizations of their internal experience vary widely enough that it's difficult or even impossible to gain a useful understanding of that experience from survey answers. Sort of like when people claim non-human mammals have no consciousness or sentience because they don't talk.

For example, just because the picture-book illustrator profiled in this article has a "vivid imagination" doesn't mean she can literally visualize a full-fidelity photographic mental image of a whole book spread. As a photographer, when I see a scene I can "previsualize" what kind of picture I might get after fully editing/printing the image days later. But that just means I can conceptualize particular visual effects, think about the lighting, texture, contrasts, colors, and put them together in an abstract thought, not that I can precisely "see" the picture exactly as if it were finished in front of me. I would say I have a "vivid imagination" for photographs, but my mental experience of remembered or imagined vision is probably pretty similar to yours.

<comment><USER8> What about people who complain about how a character looks in a movie adaptation of a book? I never see characters in a book so the movie can do whatever they want as far as I care. But other people get quite indignant over this. Can anyone here attest to what level of imagination one has to do that? I strongly suspect you're over generalizing from your own experiences, this might be a way to test it.

<comment><USER9> Maybe it's difficult to judge because people don't usually talk about it. I'd say I can visualize things just as vividly as I would experience when I look at them. That is, I won't notice every detail, but I don't notice every detail even when I'm staring right at something. I can look at something, look away for a while and visualize it, then look back at it and compare the subjective experience, and it's pretty much the same. It's more along the lines of getting the same mental stimulation of recognition and experience as I would get if I were looking at something, and it's the same as other senses. I can imagine myself on a beach, see the contrast of colors of leaves and the sky, hear the waves, feel the courseness of the sand, smell the sea, and I know from experience that if I were actually there, I would have the same sensations except I couldn't turn them off easily.

<comment><USER6> See, descriptions like this make me think that many people do indeed see clearer mental pictures than I (grandparent post) do. I'm going to have to do some informal surveys of friends and family!

</comment></comment></comment></comment></comment><comment><USER10> Is there a more objective test than telling someone to visualize something and then asking, "Well, could you visualize it?"? For instance, are there visual tasks a person with or without aphantasia objectively could not perform?

Like a psych 101 student, I immediately think I have a touch of any vaguely described mental condition, but I also know I probably don't.

<comment><USER11> How about this - Picture an elephant sideways. Don't let the elephant move. Is the trunk on the left or on the right side? If they can't answer, then it's possible they have Aphantasia.

<comment><USER12> Might want to say "side-on" instead, I rotated the elephant around the wrong axis and was confused for a moment.

<comment><USER13> Me too. I had the trunk at the bottom. :-p

</comment></comment></comment></comment><comment><USER14> > _Close your eyes and imagine walking along a sandy beach and then gazing > over the horizon as the Sun rises. How clear is the image that springs to > mind?_

Very clear; I see some cons cells, making up a list, whose CAR holds the symbol BEACH, the main connective of an abstract syntax tree describing the whole situation.

<comment><USER15> Master, let me be your padawan. Teach me Your ways, for my path is twisted and I see now I am yet to reach the Enlightenment.

</comment></comment><comment><USER16> How clear are the pictures normal people can visualize. Is it like seeing but with your eyes closed? Because what I can do is nothing like seeing. Visual memory doesnt appear like a vision. Just a vague memory.

Can people actually see memories. I'm really missing out if so.

<comment><USER17> I'm baffled as well. I had no idea people could do that. I thought that was called hallucination. I can remember images, I can't see them. I think I'm missing the point somewhere.

<comment><USER18> Can you draw things from memory, and get the general shapes and colors right?

<comment><USER6> I'm not particularly skilled at drawing, but otherwise I'm fairly sure I could do that. I can remember all the major visual details of something like a room in my house, for example. But it's still not really like 'seeing' a picture of it in my head, except for little bits at a time, or a somewhat hazy collection of the whole. If I really focus it's a bit better, but some people seem to be able to just "see" memories by default.

Also, most of the time I have a lot of difficulty pulling up a mental image of a face, even one I know well, or holding onto it if I do manage to briefly capture it. (But I don't seem to have any particular difficulty recognizing people by their faces; I'm not picking out features or anything like that -- I definitely remember faces and what they look like; I just can't see an image of a particular face in my mind (clearly, most of the time).

</comment></comment></comment></comment><comment><USER18> There was an interesting subthread on this, on another article entirely, a while back:

[https://news.ycombinator.com/item?id=9280134](https://news.ycombinator.com/item?id=9280134)

Meanwhile, I once answered a question from a person on Quora whose premise was that people can imagine "audio and visual" stimulus, but not "odor, taste, or touch". I suspect that was based on the asker's own peculiar dominant senses and style of memory, as I addressed in my answer:

[http://www.quora.com/How-come-our-brain-can-interpret- ideas-...](http://www.quora.com/How-come-our-brain-can-interpret-ideas-and- memories-as-audio-and-visual-but-not-as-odor-taste-or-touch/answer/Gordon- Mohr)

</comment><comment><USER19> I've always known I'm terrible at visualizing. The first question from the quiz in the article is "Conjure up an image of a friend or relative who you frequently see". I chose my wife whom I see for hours each day. I tried to visualize what she looks like -- nothing. Is this really so rare?

<comment><USER20> On the opposite end I remember every face I've ever seen (that has been put to a name). I remember most names and faces from each of my elementary classes including pre-school. Completely useless skill as I can't remember other things to save my life unless I read them 100 times over.

<comment><USER21> You can use it to pretend you know everyone in a party even though all you know is their face and name. :)

</comment></comment></comment><comment><USER22> I have this too. If I try to recall images of people close to me, I get an instinctive flash, which is like an outline. If I try to focus in on the detail, the image disappears.

Happens in dreams to some extent too - I generally dream normally (?) but if I become lucid then everything I try to look at disintegrates.

For the record, I'm a programmer who always wanted to do something artistic. Coming to the realization that I just wouldn't be very good took a long time to accept.

<comment><USER21> I can recall anyone in a scene. I _think_ it's a detailed image I can zoomed in, and I _think_ I have all their details (eyes, hair, eyebrows, etc) down. It's a full color scene where the person of interest can be moving in their characteristic walking style, waving their arms the way they wave their arms, and talk the way they talk. However if I try to focus on the details, it's all a blur. It's like when you have a small 50px by 50px photo, and it looks sharp. Zoom in, and you realise it was an illusion. That's exactly it for me.

I can imagine my girlfriend's foot a _little_ more in detail, e.g. changes in skin tone, but I can't remember the shape of her individual nails. Some of the details of my girlfriend's, I can see in my mind, the others are mostly a blur. I can't see in detail what I haven't noticed in real life. The details I see are because there was a scene where she made a very appropriate facial expression in response to a situation and I remember that detail very clearly - like the way she smiled and tried to convince me everyone said she had a beautiful smile on our second date.

Also - I notice the images I conjure in my mind are always a lot dimmer in brightness than when seeing images with my eye. I can remember them being bright, but I see them as dim - even when imagining the sun and the sky. It's like looking at a computer screen in bright sunlight.

It still doesn't seem that vivid to some of the people described in the article.

</comment></comment><comment><USER23> This is fascinating. I took the quiz and had to select "No image at all" for all the questions. I always knew I had trouble picturing things, but never realized others didn't also have a hard time. Strangely, I can play back songs in my head nearly perfectly, almost as if I was listening to them.

<comment><USER24> ME TOO!!! I also think almost purely in voices, sometimes my own, sometimes things others say (and I always remember the way they said it). I can play back songs I heard 10+ years ago with no problem. Some of us just think audio instead of video :) I didn't know there were others who thought like that!

</comment></comment><comment><USER25> So many people these days seem to be writing about something "begging the question", whereas I am partial to reserving that idiom for a very specific logical fallacy, and simply saying that something "raises the question" in all other cases. Alas, language evolves with popular usage, and this may be a dying distinction.

<comment><USER26> Yes it's a dead distinction in all but a very narrow area of discussion, even then in which it should be stated more plainly.

</comment></comment><comment><USER27> _But this year scientists have described a condition, aphantasia, in which some people are unable to visualise mental images._

This year? Galton (famously) published on this in 1883!

<comment><USER28> Background: [http://lesswrong.com/lw/dr/generalizing_from_one_example/](http://lesswrong.com/lw/dr/generalizing_from_one_example/)

</comment></comment><comment><USER29> I wonder if you can improve your visualization ability.

I stopped reading novels for fun about 5-6 years ago but this past year I've started reading at least one book every couple of weeks, and I feel that my ability to visualize things has improved.

On a related note, I wonder how you could measure one's change in visualization ability, since it's so subjective. I had a very difficult time answering the questions in the article, since I had no frame of reference.

</comment><comment><USER30> Just want to point out that there could be a wide range of ability to recognize faces and it's probably realy hard to find a good measure of that. If someone shows you a picture of your wife (to take an example from one comment) and a picture of eg another woman with the same hair color, skin tone, whatever, would you be able to distinguish them? I'll bet you would unless you suffer from prosopagnosia, the _loss_ of the ability to recognize faces that we know can occur after damage to a certain part of visual cortex. Then try to describe how you can tell the pictures apart. Not as easy. Artists (like the one in the article) spend all day thinking about faces (ok, not all artists, but many of them). They probably feel more confident in their ability to recognize faces and in their ability to describe them--because they discuss faces for portraits, with clients, etc. As a skeptical neuroscientist, I'm thinking you should hold off on diagnosing yourself with this condition until we come up with better evidence for it.

</comment><comment><USER5> This is supposed to be a 'condition' and an 'inability'? I have this and have always associated it with an enhanced ability to think abstractly, and more generally intellectual facility. I had never met anyone else having this, until I came upon a paragraph by Einstein who comments about his absence of mental images, replaced by geometrical-like thinking. That only confirmed my intuitive assumption that it related to enhanced intellectual abilities in the analytical and abstract thinking domain. It is therefore bizarre to read about this as a 'condition' or even 'disability'... On the bright side, it is wonderful to see that it is shared by others, even studied and meet fellow geometrical thinkers here -- hi fellow Jedis ;)

<comment><USER31> What about someone who doesn't see wire frames and are only able to visualise with features?

</comment></comment><comment><USER32> Hm, I never really realized that the rest of the world was better at visualizing than I am, but I'm definitely below average. My ability to imagine vividly comes very rarely, and, when I'm trying, I can usually only conjure a small image and only for what seems like an instant.

Definitely not the severe case that the article describes, but I didn't realize that this was unusual.

</comment><comment><USER33> i used to have this ability. i know i had it as a child. i remember visualizing fantastically complex systems.

i seem to have lost it at some point in adulthood. i have no idea when.

i started doing it again while using drugs, and this caused me to become aware that i'd lost an ability i once had. it was very hard to explain to people what this ability was, but i rememberd being able to visualize fantastically complex scenes in my head, as a kid, and getting some sense of this back while high.

in the past i could imagine any complex system of gears - like a clock, and zoom in and look at any part of it.

it's like the projector bulb is broken. an image flashes and goes away.

has anyone found a way to redevelop this?

<comment><USER34> Of course insights from drugs may not always be fully reliable, but what drug did you take, and did you try taking more?

Almost everything gets better with practice. Memorization experts have often used visio-spatial 'memory palaces', imaginary places they can fill with items to remember. Simply trying to use that technique might help build visual recall flexibility.

Perhaps it'd separately be worth trying a sensory-deprivation soak-tank?

</comment></comment><comment><USER35> My experience has been that visual vividness comes and goes with mental fatigue. When I am well rested, comfortable, and haven't spent much time thinking earlier in the same day, I can close my eyes and plainly see detail in childhood toys, places I've traveled, faces, and even illustrations from high school textbooks. When I'm tired or have spent the whole day thinking intensely, I can barely remember what my roommates faces look like. I suspect that the ability to vividly imagine images is an expensive neural process that becomes much more difficult when the brain is not at peak performance.

Curiously, my ability to recall sounds and music does not seem to change with fatigue. Whether I'm feeling energetic or super tired, I can bring to mind any song I'm familiar with or hear arbitrary words spoken in the voices of my close friends and family. My suspicion here is that simulating sound is much less expensive and therefore the ability not as easily degraded. That would not be surprising considering the anecdotal point that I can get headaches from too much sunlight but not too much noise (unless it interrupts my sleep).

</comment><comment><USER36> "But _this year_ scientists have described a condition, aphantasia, in which some people are unable to visualise mental images."

Actually this was discovered by Sir Francis Galton more than 200 years ago: [http://psychclassics.yorku.ca/Galton/imagery.htm](http://psychclassics.yorku.ca/Galton/imagery.htm)

Nor is it particularly rare.

Perhaps the most interesting aspect is not the experience itself, but the fact that people are so surprised when they discover that other people's mental experience can be so different to their own.

<comment><USER37> It does fundamentally divide humanity into those that can imagine, and those that can't. Its not unreasonable to guess others experience the world similarly to oneself; not at all interesting that folks would be surprised by that.

<comment><USER36> It's perhaps an exaggeration to describe them as 'those that can't imagine': Galton noted that inability to visualise was much more prevalent among his colleagues, the scientific men of the day, than among the general public.

</comment></comment></comment><comment><USER38> If you have aphantasia, and wantto describe it to someone else: try asking them to picture "democracy" or some other abstract concept. Most people don't then have mental images of ballot papers or flags. Then tell them that what they're experiencing is what you experience when someone asks you to picture an elephant.

<comment><USER39> That's interesting, because I did! When I read the word "democracy" I started thinking about the concept, and my mind delivered pictures (or really, scenes) to me, The White House, scenes of the UK Parliament, diagrams representing political systems, a game of Civilization, me queuing to vote at the last election etc. etc.

In a conversation that moves quickly, I probably wouldn't begin this process of streaming images, but if I spend more than a few seconds on an idea, they just start arising. To me, it is "thinking" \- it is much closer to me and more effortless than the logical articulation of abstract concepts.

<comment><USER38> I wonder if that means you hae an excess of visual imagination or I have a deficit?

</comment></comment></comment><comment><USER40> Interesting! I think I have this, though I didn't know there was a name for it. I don't imagine things visually at all -- I just kind of "feel" things. I also have a limited degree of something like touch-synaesthesia... music, mathematics and emotions have some strong haptic associations for me.

And I'm terrible at recognising faces, but pretty good at remembering facts.

</comment><comment><USER41> I usually practice the art of visualization to picturize images in my mind. The more visual impact you have in your mind, its better to create things positively.

</comment><comment><USER42> For those who are talking about how they are bad or below average at visualizing things, how do you know? Is there a test that measures this ability?

<comment><USER19> There's a quiz in the linked article that matches the one on [http://www.aphant.asia/](http://www.aphant.asia/)

</comment></comment><comment><USER43> My wife developed this as her multiple sclerosis has progressed.</comment>


Notes on Python Fabric 0.9b1 - <AUTHOR> http://www.saltycrane.com/blog/2009/10/notes-python-fabric-09b1/ <comment><USER2> Lol, I just noticed you also posted something on fabric. If I seen it I would not have submitted another entry.

One quick note. I think it's a good idea to explain that, since from the command line you are basically calling functions inside the fabfile.py, this allows you to define different environments. Something like:

def env1(): env.some_property = 'hehe'

def env2(): env.some_property = 'haha'

def deploy(): put('/%s/file.prop', '/somewhere_in_the_server/')

If you then run 'fab env1 deploy' you will copy the file under 'hehe' to the server. If you use env2 you will copy the other one. You are basically overriding the env variable. You can do the same to configure different paths for different target servers.

Really cool stuff :D

<comment><USER2> Is there a way that code could be formatted? :)

<comment><USER3> Precede the code with a blank line and then two spaces.

      $str = 'Like this.';
      echo $str;

<http://news.ycombinator.com/formatdoc></comment></comment></comment>


Investment Manager Explains Why 99.5% Of Americans Can Never Win - <AUTHOR> http://www.businessinsider.com/an-investment-managers-view-2013-11

<comment><USER2> One thing I've believed for a very long time (based on some first hand observations) and that this article backs up:

Super-rich people who got that way by doing productive things or entrepreneurial things -- people like Jeff Bezos, Elon Musk, Mark Zuckerberg, Peter Thiel, etc. -- are statistically rare. They are simply the most visible members of the superclass. The majority of people with net worth in the top of the 1% are financial or governmental profiteers who have obtained that wealth by playing financial games or profiting off the public.

In other words: the majority, but not all, of the mega-rich are parasites.

This I think has important political consequences. It's one of the reasons I am skeptical of populist "tax the rich!" schemes.

My strong speculation would be that the productivity of the mega-rich is inversely proportional to their political pull. I base that on the fact that this rule of thumb holds lower in the hierarchy-- those who are of the highest merit are rarely those with the most political skill and influence since few people have time to invest in both. People tend to be good politicians or good producers but not both.

As a result, soak-the-rich schemes are likely to thin the ranks of the productive elite and the recent entrants to the elite ("neuvo riche") while leaving the true oligarchy largely untouched. In fact, the true oligarchy would likely find ways to profit from it. In the long run it would impose a stronger glass ceiling between the superclass and the rest, making them even more like a true feudal nobility. It would make the situation worse.

I am not sure what, if anything, can change this situation in the short term.

I do have one weird suggestion: make it easier to become super-rich. Create some mechanism, possibly in tax law, that vaults people up through the last two or three glass ceilings... maybe something like a mildly progressive tax with sharp dips or fluctuations at major milestone points in the wealth distribution curve. So once you hit a point where there would otherwise be a glass ceiling, your tax rate drops precipitously for a while. It would be of paramount importance that this mechanism be impartial -- that it exclude political gamesmanship as a factor.

This is both counter-intuitive and unfair, so why would it be a good idea? Because it would bum-rush the country club with neuvo riche folks with new ideas. Some of these new ideas might change the system in ways that would benefit the rest of us. Even if there was no direct benefit to the lower 99.5%, it would prevent the ultimate nightmare scenario: the calcification of this elite into a true closed feudal nobility presiding over some kind of new dark age.

Edit:

I realized that while I've never read the idea above anywhere before, I have heard a similar idea in the realm of representative democracy... namely to vastly increase the number of representatives. The idea is to have a Congress made up of 30,000 delegates and a Senate made of up 5000 or something similar. It's basically the same concept... make the system more democratic by making the pyramid fatter at the top.</comment>


Problems that ruined my world - <AUTHOR> http://lbrandy.com/blog/2009/07/a-brief-history-of-problems-that-ruined-my-world/

<comment><USER2> I think the simple answer to the airplane on a treadmill problem is that once you understand what the problem is REALLY saying, the problem becomes uninteresting and trivial. If the problem wasn't intended to give the impression of a stationary (with relation to the surrounding air) plane taking off, no one would've cared in the first place and there would be no discussion. No one is getting confused by math or aerodynamics or physics or anything. They're getting confused by a problem intended to be confusing.

<comment><USER3> Physics is not intuitive for most people. The aircraft problem works for the same reason you can yank a table cloth from under a wineglass without knocking it over. But watch someone do that and it will seem like a magic trick.

Edit: Perhaps a better explication might be how a tail wind increases a modern cars top speed at almost a 1 to 1 ratio.

</comment></comment><comment><USER4> There's an obvious intuition that the author seems to be missing with the 'two aces' paradox.

If you have a hand with two aces, you have two chances of getting the "Ace of Spades." Having a hand with two aces doesn't make it any more likely to have "an ace" than having a hand with one ace does.

This pretty much explains the phenomenon.

<comment><USER3> Does that logic somehow change when someone says:

      "I have an Ace."
      (You calculate the probability.)
     "Then they say I have an Ace of harts."
      (You calculate the probability.)

PS: I suspect the actual answer relates to how you talk about your hand in bridge.

</comment></comment><comment><USER5> Airplane on the treadmill will take off huh?

You know those big giant things sticking out from the side of the fuselage? They're called wings. Air flowing over the and under the wings creates different pressure; hence, lift. There is a magic speed for each aircraft that over which the lift will be sufficient to move the entire aircraft vertically. For a 747, this is 180 mph/290 km/h at 80,000 lbs. That's pretty fucking fast.

Any movement relative to the ground that is under that speed will not result in flight. This is true even if the aircraft is actually in the air.

If, as the problem states, the treadmill can equal the forward thrust of the engines, no lift will be produced by the wings, ergo, it will stay right where it is.

This is why aircraft have an airspeed and a ground speed. It's also why stalling is a major concern.

EDIT: the fact that finding a treadmill that can act in a manner as suggested by the problem is impossible is another issue completely.

EDIT 2: Think people: They have breaks on aircraft wheels do they not? (They do) You can sit on a runway with the engine revved equal to your break ability and _not move_. If the engine in the problem can outperform the treadmill, you've solved a different problem.

<comment><USER6> Airspeed over the airfoil, not groundspeed is the primary factor involved in lift. The logical fallacy in your argument is thinking that the wheels provide the forward momentum, but they don't, it is the propeller that does.

That being the case, the plane will be pulled forward down the runway irrespective of how fast the treadmill under it is moving because the speed that the wheels rotate has nothing to do with how much airspeed is generated, other than the negligible friction that is transmitted to the airframe through the wheel bearings.

Said another way: a car traveling on the treadmill will be slowed becasue its forward momentum is transferred through the wheels. An airplane will not be slowed because the forward momentum is generated by the propeller and has nothing to do with how fast the wheels are spinning.

<comment><USER5> >Airspeed is the only factor involved in lift.

The only way to achieve airspeed required for flight when you are sitting on the ground is to move the wheels. (ie, roll forward).

Your argument suggests that if the aircraft was attached to the ground with steel beams it would somehow break free into glorious flight. It would not.

The treadmill removes the ability of the aircraft to achieve correct airspeed, regardless of whether it is powered by prop, jet or ion engine.

Any assumption that the aircraft can move forward is predicated on the fact that the treadmill cannot match the engine's output. This is accurate, but like I said, outside of the scope of the problem.

Try this:

1\. Aircraft has floats, not wheels. 2\. Aircraft's normal take off speed is 100 kts. Let's say the engine can produce a take off speed of 100kts at 2000rpm. 3\. Aircraft is on a river moving the opposite direction at 50kts.

Q: Will the engine be able to achieve the required 100kts airspeed at 2000rpm? If not, if I can somehow match the river to the airspeed, is it not sound theory that I can prevent the aircraft from _ever_ reaching that 100kts take off speed?

<comment><USER6> The treadmill does not remove the ability of the plane to move forward. If it did, you are absolutely correct, the plane could not fly.

The wheels on an aircraft are not attached to any drive mechanism, they are free spinning. In the scenario described they would act as a bearing and mitigate nearly all of force applied by the treadmill. There simply isn't enough friction transmitted to the airframe to counteract the force created by the propeller.

An airplane with no airspeed sitting on a treadmill would not fly, as you say. An airplane generating enough airspeed will. The treadmill does not prevent the airplane from moving forward with sufficient airspeed.

<comment><USER5> The wheels not being powered is irrelevant. The engine produces forward power. The plane moving forward causes the wheels to move in relation to the forward power of the engine.

By your logic, putting breaks on aircraft wheels would be irrelevant. But guess what, they can and do stop the aircraft from rolling forward.

If you counter that movement - of the wheels - you counter the forward movement of the aircraft, because the movement at this point is against the ground, not the air.

Ergo, no flight.

<comment><USER7> The plane will fly, and the wheels will spin at the double of the airspeed. The engines 'push' against the air, not the ground.

</comment></comment></comment></comment></comment></comment><comment><USER8> My issue with this problem was that it was presented rather poorly to me the first time. Instead of saying that the treadmill matched the negative of the velocity of the plane relative to the ground, the questioner instead stated that the treadmill "matched the speed of the wheel." I took this to mean that the treadmill matched velocity of the wheel as would be given by a conventional speedometer.

Of course, this is prima facie ridiculous. Consider, at any nonzero speed, the speed of both the treadmill and the wheel would quickly approach infinity. Given that the speedometer speed would essentially be the velocity of the wheel + the tangential velocity of the wheel touching the treadmill, the entire thing would just blow up (remember, non-slip == velocity of the wheel == velocity of treadmill). Therefore, I basically answered c) it's a stupid problem and the plane wouldn't move.

Of course, if you define it this way, than it is obvious that the plane would move.

</comment><comment><USER9> Geez, people, for the love of Pete, even if you can't wrap your brains around why the plane would take off at least learn to spell "brakes" correctly!

</comment><comment><USER10> Awesome, I'd love to see more links like this if anyone has them.

<comment><USER11> [http://en.wikipedia.org/wiki/Category:Probability_theory_par...](http://en.wikipedia.org/wiki/Category:Probability_theory_paradoxes)

and more generally - <http://en.wikipedia.org/wiki/Category:Mathematics_paradoxes>

Apologies to anyone who was expecting you to get work done today.

<comment><USER10> Haha thanks!</comment></comment></comment>


Show HN: Gradient Hunt - <AUTHOR> https://gradienthunt.com <comment><AUTHOR> Hey Hacker News,

Gradient Hunt is a curated collection of beautiful gradients.

The Story While finishing up another side project (Html Colors), I unexpectedly noticed the popularity of colors and gradients websites. I started this project because I wanted to create a webapp and learn vue.js

Solid colors are useful, but what was missing was a tool that enables non- technical folks to create and use all the beautiful gradients. I wanted to make a website that was so intuitive and easy to use that you can understand it in less than 30 seconds. So Gradient Hunt was born .

🇦🇷 Maker Bio My name is Franco, I'm a 15 years old kid from Argentina, designer and web developer with a big passion for colors. I developed Gradient Hunt in the last 2 months. I maintain, review gradients, and update Gradient Hunt on a daily basis to showcase the very best of the gradients the users create.

Please let us know what you think! I would love to hear your thoughts

<comment><USER2> At first glance, I think this likely qualifies for a Show HN. Let me suggest you go to that section of the site, read the rules and consider resubmitting this as a Show HN (or changing the title on it).

[https://news.ycombinator.com/show](https://news.ycombinator.com/show)

[https://news.ycombinator.com/showhn.html](https://news.ycombinator.com/showhn.html)

<comment><AUTHOR> Thank you for the suggestion, i've already changed the title to Show HN: Gradient Hunt and it nows appear on the show section.</comment></comment></comment>


Trying to make sense of Colombia's "Strata" economic system (2014) - <AUTHOR> http://occasionalplanet.org/2014/09/09/trying-to-make-sense-of-colombias-strata-economic-system/ <comment><USER2> My theory is that as a lot of people don't declare their full income in developing countries (and are quite tax-adverse due to a perception of high corruption), a way to redistribute is to tax "luxury" goods like vehicles or other visible stuff like the strata.

<comment><USER3> As a Colombian I can say that most people declare full income due to fear of being chased by DIAN (colombian IRS) which is probable the most corrupt institution in the country, meaning that if you don't declare your full income they'll shake you down for everything you have, I've personally heard cases of people making innocent mistakes in taxes and getting extorted for millions upon millions by "honest DIAN officers".

The strata system was created to create a form of "equality" where rich people helped poor people via subsidies, however, this has been abused by both sides since the very beginning (poor people using 10 or 20x the normal amounts of water and electricity to "fuck the rich people" and rich people paying to get their houses declared "historical patrimony" to avoid paying subsidies)

In the end, the strata system was created for a different society that we have right now, nowadays almost all buildings are estrato 3 or 4 in areas where estrato 2 was the highest possible.

I have no idea what could replace the strata system (I'm not a political scientist or anything that resembles that) but I do agree that the system is broken and should be replaced by something better.

<comment><USER4> How about replacing it with nothing?

<comment><USER5> No system of taxation?

If you can show us a modern functional large-scale (i.e. nation-sized) society that has no taxation, then I'd love to see how they do it.

I can't think of any examples, though, so would welcome your thoughts on this.

</comment></comment></comment></comment><comment><USER6> On the surface this looks a little bit like a Land Value Tax, which tends to get broadly praised by economists as efficient and fair. Enforcement and structure appears to be uneven, but it doesn't sound much different from property taxes here in the US.

<comment><USER7> It's a different animal than property taxes (which we have in Colombia too.)

If you want to comparison shop high speed internet access, for example, you have to get a quote from each provider, as the rate is based on your estrato. Things have gotten better recently but until the last couple years, those rates were just in a big binder in the office, not something you could just look up online. I feel it hurts competition - providers can't just advertise a monthly rate - and I can only imagine the added complexity in billing systems, etc, that ultimately is passed on to the consumer.

<comment><USER8> Well, is this really wrong? If I get work done on my house as a young person, I pay as much as 10x what the same workman would charge my grandmother in law. The workman _knows_ he/she can get away with charging a young person who doesn't have to live off social insurance more. The workman would never get the job from a retired in Prague if they charged what they charge yong people. However, if they charged everyone the reduced rate, then they would never cover the cost of tools and training.

</comment></comment></comment><comment><USER9> Although the Stratum idea seems logical and even good (at least for me) the basic problem in developing countries is always the same: widespread corruption and wirepulling.

</comment><comment><USER10> Reminds me of the South African system. Enforcement of electricity levies depends very much on location. Townships vs leafy suburbs</comment>


Show HN: Bunchy - Social Funding - <AUTHOR> http://bunchy.com

<comment><AUTHOR> Hey guys! Just wanted to show you version one of a product I'm building. It allows anyone to instantly generate a funding page and if you hit your target, the money is moved to your account via Stripe.

Because of Stripe we only support UK, US and Canadian customers at the moment.

Once a project is funded you can export the emails and other data and there are no limitations on project type, amount, etc. People are free to create as many as they want.

<http://i.imgur.com/om4cKXq.png></comment>


Ask HN: Would you live in a city built from scratch? Why? What'd it be like? - <AUTHOR> <comment><AUTHOR> I'm the OP.

I would live in a city built from scratch at two conditions: it would represent an acceptable compromise, compared to an existing city like SF or London, and it would include a lot of innovation in how it's built, operated, how transportation works, its environmental impact, etc.

</comment><comment><USER2> You should check out Reston, Virginia, it is a fully planned community. It was built with some interesting ideals, like everyone should be able to walk to a small shopping center and a walking trail.

[https://en.wikipedia.org/wiki/Reston,_Virginia](https://en.wikipedia.org/wiki/Reston,_Virginia)

<comment><AUTHOR> Thanks for the tip. I will.</comment></comment>


Against intellectual property - <AUTHOR> http://danny.oz.au/free-software/advocacy/against_IP.html

<comment><USER2> There is also a good book of the same name:

[http://mises.org/store/Against-Intellectual- Property-P523.as...](http://mises.org/store/Against-Intellectual- Property-P523.aspx)

...as well as the more in-depth, similarly-titled and themed Against Intellectual Monopoly:

[http://levine.sscnet.ucla.edu/general/intellectual/againstfi...](http://levine.sscnet.ucla.edu/general/intellectual/againstfinal.htm)

Those inclined to opt out of the copyright game, put your code where your mouth is and release your next software project using this:

<http://unlicense.org/>

<comment><USER3> It's a bit misleading to say the unlicence is an opt-out of the copyright game. The Public Domain is a complicated area, particularly internationally and you may not be allowed to opt-out in this way.

What exactly is being gained over BSD or Apache 2.0 licence to compensate for this risk?

And since "intellectual property" extends to more than copyright, how does this impact on patents etc.

Finally, if you're allowing others to come along and combine your work with their and then patent and copyright the result, it's not really an effective protest "against intellectual property" is it?

This is all covered in the article itself.

</comment></comment><comment><USER4> Robert Laughlin's The Crime of Reason and the Closing of the Scientific Mind, Basic Books, 2008 is a interesting and provocative examination of the issue of intellectual property and how it interacts with free market ideas. The key question is "what can be owned?".</comment>


Opera Q2: Sales Up 32% To $52.1M; Mobile Surges, Desktop Flat - <AUTHOR> http://techcrunch.com/2012/08/22/opera-q2-mobile-browse/

<comment><USER2> I am really surprised and many time pissed off ( as a Opera user) that Opera desktop doesn't have as much user share as it should. I don't know what it missed. Many of the new features in browsers these days would trace back to Opera. Many features in Opera are not found in other browsers. But still, it remains flat. Sad.

<comment><USER3> I use and am a fan of Opera as well, but the features you talk about are UI features. Those are nice, but what matters is standards compatibility and that is where Opera lags behind.

Just to name a few missing things: flexbox (supported by most browsers for years now), no requestAnimationFrame, no IndexedDB, no css calc(), No blob urls, no 3d transforms.

<comment><USER4> As a developer we still cannot use them until we can drop support for IE8. So it really does not matter at all if other browsers support them or not.

<comment><USER3> Who is this we you speak of? You can drop support for IE8 any time you want. I'd rather not drop support for the latest version of Opera though, which I've had to do simple because it doesn't have flexbox.

<comment><USER4> How can you say you can drop support for IE8? Its still hugely popular (13+% of market). While I love opera (my daily browser but only 2% of market) I could see dropping support for Opera before IE8, until IE8 loses more market share.

<comment><USER3> > How can you say you can drop support for IE8?

Simple, I don't live in a world where the target audience for every site I write is 100% of available web users. Some projects are directed at corporate users with IE8, some are directed at mobile browsers.

</comment></comment></comment></comment></comment></comment><comment><USER5> Even though I switched to Chrome, I hope Opera does well. It still has my heart, I've used it for seven years or so.

</comment><comment><USER6> Even though it can't compete with the marketing of Chrome and Firefox, Opera is still the best browser.

</comment><comment><USER7> Ok, sales up. How about usage? I had Opera Mini on my Sony-Ericsson a few years ago. Used it maybe half a dozen of times.

<comment><USER8> I use it all the time - 3G coverage is patchy where I live, and Opera Mini is far quicker and more reliable over a slow mobile connection than trying to load a bloated 300k+ page over a 12kbps GPRS link.</comment></comment>


Ask HN: RSS backend with  30 days retention? - <AUTHOR>

After Google Reader went away I switched to Feedly, but they only keep 30 days of items (as did Google).<p>Does anyone know of an RSS backend that keeps more?  Preferably 90+?  And ideally with search functionality. <comment><USER2> Try inoreader, it keeps a full history[1] and has full-text search.

[1] [http://forum.inoreader.com/index.php?/topic/27-inoreader- mai...](http://forum.inoreader.com/index.php?/topic/27-inoreader-main-faq/)

BTW, Google Reader kept 300,000 items per feed, not 30 days worth. Are you thinking of unread status instead? inoreader has the same limitation.

<comment><AUTHOR> Hmm, I thought it was also doing 30 days max. Feedly is doing that now for sure.

I will check out inoreader - looks like even if it doesn't archive the items forever or for a long time, it can support push to "Pocket, Instapaper, Readability and Evernote" which would wind up doing the same thing. It'd potentially make browsing by feed more difficult but may be worth a shot.

</comment></comment><comment><USER3> I use Fever[1] which is self hosted and lets you keep items up to 10 weeks.

[1]: [http://feedafever.com/](http://feedafever.com/)

<comment><AUTHOR> Thanks! I had seen that and may have to go that route.

I was hoping not to go down the self-hosted path as I'd wind up spending way too much time tinkering (gatewaying to Usenet, adding features, etc).

</comment></comment><comment><USER4> Rssident.com

Archived indefinitely. Fully searchable by feed title, url, author, entry title, and entry content.</comment>


I Sold $13,000 of a Card Game in 2 Months Then Got Sued and Lost It All - <AUTHOR> https://hackernoon.com/how-i-localized-cards-against-humanity-gamed-instagram-made-dollar13000-and-got-shut-down-by-university-n97y3y7s <comment><USER2> That website's cookie notice is in blatant contravention of EU law. They set cookies if you even attempt to scroll, and you cannot opt out.

<comment><USER3> Do you actually feel that there is an interesting conversation to be had about this? I doubt it.

If you don't want sites to set cookies, don't let them.</comment></comment>


Microsoft acquires statistical software company Revolution Analytics - <AUTHOR> http://venturebeat.com/2015/01/23/microsoft-acquires-statistical-software-company-revolution-analytics-for-big-data-insights/ <comment><USER2> Microsoft probably ran out of successful Windows proprietary based companies to buy. Skype, Visio, Yammer, Great Plains Software, ...

[http://en.wikipedia.org/wiki/List_of_mergers_and_acquisition...](http://en.wikipedia.org/wiki/List_of_mergers_and_acquisitions_by_Microsoft#Acquisitions)</comment>


New Iphones... - <AUTHOR> http://www.apple.com/uk/iphone-5s/

<comment><USER2> And still Apple.com is not using responsive design, to be viewable on say, an iPhone...</comment>


Show HN: Minimize downtime with Laravel-online-migrator - <AUTHOR> https://github.com/orisintel/laravel-online-migrator <comment><AUTHOR> This unofficial package for Laravel tries to ease the pain of running Laravel DB migrations on large, MySQL tables. It converts them to pt-online-schema- change commands. While it cannot completely shield developers from the intricacies of PTOSC it can help keep the migrations table updated and the migrate commands consistent.

Traits are also provided to mark migrations known to be incompatible.</comment>


HTML and CSS Learning Tool Recommendations - <AUTHOR>

What's the best tools for teaching a designer type person HTML and CSS?  Book recommendations or online tools would be great.  An online tool that lets you build HTML and CSS, and learn in process the would be awesome too. <comment><USER2> There are so many tools, websites and books out there at the moment. Firstly, I would recommend your start on HTML5/CSS3 instead of looking at older stuff.

A very cool, high level site: <http://diveintohtml5.info/>

Smashing Magazine's website is pretty cool too and they have some good ebooks and printed books on HTML5/CSS3.

Look at <http://www.html5rocks.com/en/> for sample code and tutorials.

Some tutorials on tripwire: [http://www.tripwiremagazine.com/2010/07/30-very- useful-html5...](http://www.tripwiremagazine.com/2010/07/30-very-useful- html5-tutorials-techniques-and-examples-for-web-developers.html)

There are tons, too many to list. You should also look at Meetup for local HTML, front-end, web dev meetups. They've been super useful for me, especially meeting some of the dev community...

Have fun!

</comment><comment><USER3> I just started on the same path as you (although I am not a designer). You have a distinct advantage so you're good to go. I used this resource initially despite the date (pre-HTML5)

<http://www.w3schools.com/html/default.asp>

I would also recommend finding someone who is knowledgeable about HTML and CSS. I have a "mentor" of sorts and he is both challenging me and helping me. I would also suggest just choosing sample sites to create once you have a grasp. Make a web design with all the features that look really cool and don't take the easy way out. Design it just like you want and figure out the way to code it. Good luck!

</comment><comment><USER4> I used 'CSS: The Missing Manual' to learn how to build CSS based layouts several years back. It obviously doesn't cover CSS3 (unless it has been updated). Reading it from cover to cover was enough for me to get started, and then going back to it occasionally (and google) as a reference.

It's sitting in a stack of books that I need to dispose of so if you're interested then I'll send it your way.

Edit: Although the book doesn't cover CSS3, the book teaches you what you will learn anyways (as CSS3 builds on existing concepts (as well as adding some new ones)); so you don't have to worry about learning outdated 'dis-information' (I think!).

</comment><comment><AUTHOR> Thanks for all the replies. I'm looking for something a little less geeky though. These are all great resources I could understand as a programmer, but I need to teach a designer HTML/CSS. I think "CSS: The Missing Manual" is more up the alley I'm looking for but is kind of long.

</comment><comment><USER5> Hey, I'm a little late to the party but I created a page on my blog of the process I used to learn HTML & CSS. You can check it out here:

<http://dlfrancisco.posterous.com/pages/learn-code>

Enjoy!

</comment><comment><USER6> You may want to give <http://www.teamtreehouse.com> a shot. They have some pretty solid videos and also allow you access to their very active Facebook community. Worth trying out for a month at least.

<comment><USER7> I echo this. The stuff on there is mostly rock solid as it is and they keep adding new material. They keep you motivated by awarding you badges as you go through the learning process. Pretty sweet team behind it too; attentive and responsive to feedback.

</comment></comment><comment><USER8> Go to noexcuselist.com and look at the programming section.

Lots of quality sites listed, a lot of them targeting beginners

</comment><comment><USER9> Once you understand the basics of HTML and CSS syntax, I recommend reading the CSS box model specification. It will tell you exactly how layout is supposed to work, and you will be able to understand the various tutorials as derivatives of that model. The CSS spec is a good read in general for learning the styling features.

Other good resources include A List Apart for tutorials and Peter Paul Koch's web site for discussions of cross-browser interoperability.</comment>


Windows 8 to feature a Dropbox-like sync in Windows Explorer - <AUTHOR> http://www.istartedsomething.com/20110403/windows-8-explorer-teases-file-syncing-and-web-sharing/

<comment><USER2> That's a misleading headline; there's no indication that the "sync" feature will be any more Dropbox-like than any of Microsoft's previous attempts at sync (like Groove, or Windows Live Sync, etc.)

Sync is so-well-known a problem at Microsoft that Joel devoted an article to the "architecture astronauts" wrapped up in it back in 2001. In fact, we're two weeks from the 10th anniversary of that retrospective. <http://www.joelonsoftware.com/articles/fog0000000018.html>

EDIT: Actually, this 2008 article by Joel adds more to the story: <http://www.joelonsoftware.com/items/2008/05/01.html>

<comment><AUTHOR> Well, a solution to synchronize your files directly from your Windows Explorer up to the cloud is a "dropbox-like" feature.</comment></comment>