DuckDuckGo integration with StackOverflow is now live - <AUTHOR> http://duckduckgo.com/?q=nginx+apache+lighttpd <comment><USER2> Thx for the support! Here's some background: full punctuation should be indexed; it's using the SO CC dumps (<http://blog.stackoverflow.com/category/cc-wiki-dump/>); only "good" Q&As are showing; additional logic to only show when relevant to search term.

I'm really against false positives, so I know there are a lot of false negatives out there as a result. If there are particular examples (where you think something should have come up but doesn't, or visa-versa), please let me know and I'll work on it. I'd welcome other improvement ideas as well.

Note that there is a lag because I'm using the dumps, so anything within the past month or so won't be there.

<comment><USER3> Two things -

1\. That box is really tiny. Could there be a way to make it larger?

2\. Here's an example of when I think something should have come up, but doesn't: <http://duckduckgo.com/?q=python%20pad%20string%20with%200>

What I want is #2 on that list, but I don't get any nice little box.

<comment><USER2> Thx. 1) Would being able to drag it bigger help? 2) will look into this one.

<comment><USER2> Update: the python pad string example isn't working because of the indexing of punctuation (python: in question title). Will re-work this for next release.

</comment></comment></comment></comment><comment><USER4> Given recent comments I've seen about the searchability of SO, I think they owe you a beer.

<comment><USER5> Message just sent: "Consider yourself invited to lunch at our office or a beer after work any day."

<comment><USER2> Just replied: Haha, I'm in Philly and my sister lives in NYC so I might just take you up on that :)

</comment></comment></comment><comment><USER6> By the way... In IE8, the middle mouse click to open results in a new tab is broken. If the popup blocker is turned on it will simply open the page in the same window. If the popup blocker is turned off, it opens the results in a brand new window rather than a tab.

It works as I would expect in Chrome and Firefox.

<comment><USER2> Thx--thought I fixed this :). Will revisit.

</comment></comment><comment><USER7> This is only tangentially related to the post (congrats on the cool new feature!), but my biggest gripe with DGG is that for some reason it never seems find projects hosted on github.

Case in point: [http://duckduckgo.com/?q=clojure-maven- plugin&v=](http://duckduckgo.com/?q=clojure-maven-plugin&v=) vs. [http://www.google.com/search?hl=en&q=clojure-maven- plugi...](http://www.google.com/search?hl=en&q=clojure-maven-plugin)

It's so bad that I always add "!g" to a search if I know that the page I'm looking for is hosted on github.

Anyway, DGG is still my default search engine. Thanks and keep up the great work.

<comment><USER2> That's weird because I source github ([http://duckduckgo.com/?q=Merb+messenger&v=](http://duckduckgo.com/?q=Merb+messenger&v=)), though it's true there is a lag. I'll look into why that's not getting picked up; must be a bug in there somewhere. If only every site had dumps :).

</comment></comment><comment><USER8> This is a cool integration hopefully they will add the other official sites as well. It would be nice to have mixed results like this:

[http://sess.ioncannon.net/#q=nginx%20apache%20lighttpd&p...](http://sess.ioncannon.net/#q=nginx%20apache%20lighttpd&p=1)

<comment><USER2> All three (SO, SU, & SF) are in there.

</comment></comment><comment><USER9> Impressed. I was going to make a comment about how this could break some searches outside of the development field but when I typed in just "django" it gives me all the options of what "django" COULD mean, allows me to select the one I want, and then searches on that.

</comment><comment><USER10> Such integration is cool, but I think the box needs work. It is ugly and hard to read, imo. :(

</comment><comment><USER11> Did you want to remove the same result from the list further down? It also appears as item 4.

<comment><USER12> Probably best not to, since people may ignore the zero click box and in general have no quick way of knowing that they are related.

</comment></comment><comment><USER13> Can you make there be a way to expand the content while staying on the same page?

</comment><comment><USER14> Now do reddit!</comment>


UberXL – low-cost SUV option - <AUTHOR> http://blog.uber.com/uberxlsf

<comment><USER2> Competition is GOOD [1]. This is a brilliant branding extension, it's clear on the value and the audience it's targeting. UberX - UberXL.

1 - [http://blog.lyft.com/posts/2014/5/7/introducing-lyft-plus- th...](http://blog.lyft.com/posts/2014/5/7/introducing-lyft-plus-the-premium- ride-redefined)

</comment><comment><USER3> Is there a $1 safe ride fee on this? Or are these considered unsafe?</comment>


Announcing UnQLite: An Embeddable NoSQL(Key/Value + Document store) Database - <AUTHOR> http://unqlite.org/forum/announcements-unqlite-1-1-6-out

<comment><USER2> In case you are wondering how this is this different from Tokyo/Kyoto Cabinet [1], the cached version of the unQLite site [2] states: "unQlite is a document storage engine like MongoDB, Cassandra, Riak and so forth as well a key-value storage engine like Berkeley DB, Tokyo Cabinet."

Also, this does not appear to be the unQLite that Richard Hipp, creator of SQLite, has said he plans to create [3]. This unQLite is created by one Mrad Chems Eddine [4].

        1: http://fallabs.com/
        2: http://goo.gl/M9nzq
        3: http://en.wikipedia.org/wiki/SQLite#History, http://www.infoq.com/news/2011/08/UnQL
        4: http://unqlite.org/licensing.html

</comment><comment><USER3> Couldn't you just use sqlite with blobs? Or, you know, use files?

</comment><comment><USER4> So we've reinvented BerkeleyDB?

Why?</comment>


Show HN: Blazemetrics.io - Automated time tracking for dev teams - <AUTHOR> Automatically track time using Github commits. Integrates will all popular IDEs. Get beautiful dashboards that display overall project health, progress, time sheets and cost vs. budget. <comment><USER2> Looks similar to [https://wakatime.com](https://wakatime.com) but focused solely on Git-based projects. From the source code, the time tracking is done the same way using periodic heartbeats from the IDEs.

Disclosure: I built WakaTime.

<comment><AUTHOR> Although we do track time in the same way, I think our focus is very different.

There are more platforms in the pipeline beyond just Git projects coming.

I think the major differentiator is our product is more business focused, and designed to measure overall project health and team productivity where WT seems to be more about individual measurement.</comment></comment>


Ask HN: How do I meet qualified business and marketing people? - <AUTHOR>

I have been interested in starting a company for a while now, but I am having trouble finding a qualified partner with business and/or marketing skills. I've gone to a few networking events, but I find that 90% of the people there are geeks like me, web designers or get-rich-quick/MLM types. How did you find your partner (or vice-versa)? <comment><USER2> I'm looking for a partner myself...definitely not an MLM type, for they can go to HELL. LOL. Seriously, in regard to your note, I'm opposite. My degrees are in information systems; as a result, strong in business/marketing, but skills in software development are light. Although, I have programmed lightly backed in college. But again, my strengths are in business/strategic planning/marketing.

see my post if you'd like: <http://news.ycombinator.com/item?id=905652>

</comment><comment><USER3> Try Twitter! Use Twitter search and enter in terms specific to the problem you are trying to solve. You'd be surprised how many qualified people are on Twitter and sharing their ideas and willing to help. That is how I found a developer for a project I am working on!</comment>


Crocodoc's HTML5 page flip - <AUTHOR> http://web.crocodoc.com/experiments/html5-page-flip/ <comment><USER2> This is cool from a programming perspective but it is poor UX. I believe everyone on HN knows this but the problem area are my clients. They run across stuff like this and think it looks cool/fun. Instead of listening to reason they demand stuff like this and end up with bad websites because all I can do it advise them but then make what they want.

Please stop spreading bad UX, leave page flipping to actual pages/paper.

<comment><USER3> Agreed. HN loves to criticize Apple for forcing their UIs to mimic real-life (think Newsstand, leather stitching, etc), but still considers things like this desirable.

From a technical perspective, it's cool. Please don't use this on real sites!

<comment><USER4> >HN loves to criticize Apple for forcing their UIs to mimic real-life (think Newsstand, leather stitching, etc)

Ornament does not impact usability. In your two listed examples, they do not influence how the user interacts with the software.

This page flip is an example of mimicking real-world interaction and not just appearance.

</comment></comment></comment><comment><USER5> Can't wait to see CSS Shaders land, then we can do this and correctly deform the HTML to make it look like it is on the "paper" (instead of being clipped to the paper). Still, with the curves they use it looks pretty good as is.

It's nice to see the web platform is capable of effects like this and I think the "usability" complaints in other comments are lame. You could use this to hide controls underneath a UI (ala Maps on iOS), for example (though maybe if you're "zen of palm"ing it you'd rather minimize clicks and put buttons everywhere, your choice); it doesn't have to replace scrolling.

<comment><USER6> Great point about the usability possibilities. There are probably tons of creative ways to use this effect since it's SVG based. I found myself assuming too that this would be used as presented (as a flipbook) so I think this experiment becomes even cooler once you get outside that frame of reference.

</comment></comment><comment><USER7> While this is (technically) interesting, I don't see it being useful at all on a computer. Page curls are good on devices that can somewhat mimic a page but it really just feels awkward with a mouse or trackpad.

<comment><USER8> Zoelle from Crocodoc here. I completely agree with your assessment. Our goal here is to explore what's possible from a technical standpoint using SVG — we don't mean to suggest that this page flip interaction should actually be used when reading documents!

</comment></comment><comment><USER9> When done well, a skeuomorph helps a user to feel comfortable with an interface. Slight textures in digital interfaces help them to feel tactile. Good skeuomorphs take cues from an analog world to help a user navigate a digital one. when done poorly, the skeuomorph forces the user to deal with an interface in an outdated way by blatantly ignoring the fact that the interaction is being done on a platform that is capable of handling new and improved interactions.

This "page turn" skeuomorph really bothers me. If there is to be any animation at all, it should be to cover up load time, and the user should not have to click and drag with an extremely RSI-incuding stroke to get the page to turn. It feels like the page weighs 50 pounds. Digital interfaces are not material. They are supposed to be frictionless. They are supposed to take the work out of interaction.

I want to click on the right side of the page and have the animation quickly play so that I can get to my content. Focusing on the entire page flip takes me right out of the content.

I know that a book in real life takes some effort to hold, and some effort to flip a page, but designers should really reconsider designs that "look pretty" but keep that same effort around when they translate a book into a digital format.

I cringed when I first saw this kind of behavior in Flash. One or two people figured out how to program a page turner, released a tutorial and everyone was off to the races to create their own. Excellent programming exercise - extremely bothersome UX. Now we can see the entire thing play out again, in high def CSS!

</comment><comment><USER10> First thought: this might actually make sense on tablets.

Totally doesn't work on my iPad.

</comment><comment><USER11> Some time ago, Google released <http://www.20thingsilearned.com> and the source -> <http://code.google.com/p/20thingsilearned/>

</comment><comment><USER12> I can't get the pager flip to go all the way over. I am using Windows 7/Chrome and clicking/dragging the bottom corner. I can't get the first page to go past the paperclip. I feel silly asking, but what am I doing wrong?

<comment><USER13> I'm pretty sure thats the way its designed. I think its supposed to stick at the clip like a real piece of paper would at an actual paper clip.

<comment><USER12> Thanks. I considered that, so, I tried to remove the paper clip. I couldn't. lol

</comment></comment></comment><comment><USER14> Is this supposed to do something on my iPad? Doesn't seem like the metaphor is really appropriate for non-tablet devices and this isnt working on my iPad.

<comment><AUTHOR> I haven't yet gotten it to work on mobile devices. Do try it again from Firefox or Chrome!

</comment></comment><comment><USER15> Much smoother without the shadow. I can't believe we're there already, the worlds famous page flipper without flash :)

</comment><comment><USER16> I don't get it, looks like a huge POS on my screen (10 inch netbook, see screenshot) [https://picasaweb.google.com/lh/photo/ScOWQmywYCDt9sJu0nQaWc...](https://picasaweb.google.com/lh/photo/ScOWQmywYCDt9sJu0nQaWcs4WckHW8ofRKlVOjAf3-s)

<comment><USER16> Same on my nexus 7 and I can mostly read the page but it still does not work on galaxy nexus. Chrome for both.

</comment></comment><comment><USER17> Great stuff Peter, thanks for sharing the latest at Crocodoc!

</comment><comment><USER18> This doesn't seem to be working for me in the latest Firefox.

<comment><USER19> hover over the bottom right corner and grab the page from there. I thought the same thing at first.

</comment></comment><comment><USER20> The comments on this article border on shameful. Props to crocodoc for building this. The demo is really good, and there is a lot of impressive attention to detail: try pulling a page up while a page is already flipped.

Screw the misplaced hate and self-righteous UX criticisms. This is a tech demo. Much like chrome experiments. Appreciate it for what it is.

</comment><comment><USER21> I've seen this done a couple of different times, and it still makes zero sense from a usability standpoint. What is wrong with vertical scrolling? The entire gesture of clicking and dragging is awkward and makes zero sense when using a computer to read content.

</comment><comment> at-fates-hands Annnnnnnnnnnd if I don't your using page flip, how am I supposed to figure out how to use this page, or know if there's even additional pages I should see?

Interesting concept, but the user experience is seriously lacking.

</comment><comment><USER22> Yeah, you should try that in IE 10. Probably looks much more different than Webkit and Mozilla.

</comment><comment><USER23> Does not work on iPad

</comment><comment><USER24> wow, this is super cool. Good work!

</comment><comment><USER25> What if this is specifically intended to be a tablet-only user experience? Suddenly it makes sense.</comment>


Meet Project Comet, by Adobe - <AUTHOR> https://www.youtube.com/watch?v=PD5cCBhkgTg <comment> tefo-mohapi This is quite great, looks good. Curious to see what code it generates.

<comment><USER2> The primary focus of Comet is on design and prototyping, not on generating apps directly. You'll be able to export production-quality assets for handoff to developers, or view interactive prototypes online / on devices.

That said, Comet will have an extremely powerful plugin architecture, so third-party developers in the community could certainly create plugins to export code for Angular, React, Objective C, etc.</comment></comment>


High availability and configuration management, RFC - <AUTHOR> http://blog.daniellobato.me/2014/02/high-availability-and-configuration-management/

<comment><USER2> It kind of looks like the 'guide' skips Chef altogether. Opscode docs make it look pretty easy to scale up, can anyone with a large Chef deployment share what are the pinpoints?</comment>


How to print date-time stamps using UTC ISO - <AUTHOR> What's the best way to print a date-time stamp in your favorite coding language?
So far I have demonstration code in bash, C, C++, Elixir, Go, Java, Python, and Ruby:
https://github.com/joelparkerhenderson/demo_date_time_format
Feedback and constructive criticism is welcome. Pull requests are welcome.
If you know a language and want to add it, please contribute. Thanks! <comment><AUTHOR> Link: [https://github.com/joelparkerhenderson/demo_date_time_format](https://github.com/joelparkerhenderson/demo_date_time_format)</comment>


Offline safety in a cloud app - <AUTHOR> http://blog.uxpin.com/1413/offline-safety-in-a-cloud-app/

<comment><USER2> The idea is by no means new. localStorage is old. So is the AppCache specifications that actually allows an application to go 'offline'. Gmail did this as early as 2009: [http://googlecode.blogspot.sg/2009/04/gmail-for- mobile-html5...](http://googlecode.blogspot.sg/2009/04/gmail-for-mobile- html5-series-using.html)

Unfortunately it's not as easy as it looks. I found that out when doing research for a weekend project. Here's an excellent A List Apart article detailing all the gotchas you can face while working with it: [http://www.alistapart.com/articles/application-cache-is-a- do...](http://www.alistapart.com/articles/application-cache-is-a-douchebag/). The Financial Times Labs have an interesting article talking about an approach to deploying an offline app that uses the AppCache as little as possible: <http://labs.ft.com/2012/08/basic-offline-html5-web-app/>

And of course you can find information about it in places like Dive into HTML5 and MDN, by simply searching for them

</comment><comment><USER3> This is a technical site, some technical details of the implementation would be more appropriate.

In terms of the app itself, web apps generally offer some way to fire them up straight away without having to sign up. Many users, myself included, will just click cancel on the sign up screen. You have to give us something first before we trust you with our email. Edit: I ended up looking by just entering a rubbish email address.

The landing page is very pretty, though the app looks somewhat like <https://moqups.com/> at a glance.

<comment><AUTHOR> You're absolutely right, we're working on an additional info about technical side of this feature (as a response to comments).

Showing the app before signing up is something that we're constantly thinking about. Probably it's about the time to make it comes true. My apologizes for the inconvenience.

Moqups.com is great, but it's really focused on a different problem.

UXPin - The UX Design App (<http://uxpin.com>) helps teams fighting for the best UX Design possible of their web&mobile apps, during whole design process.

You can create wireframes, interactive prototypes, upload requirements, personas, visual design - and discuss each deliverable in one place.

ps. We were launched way before Moqups :)

</comment></comment><comment><USER4> I thought localStorage was evil. [http://hacks.mozilla.org/2012/03/there-is- no-simple-solution...](http://hacks.mozilla.org/2012/03/there-is-no-simple- solution-for-local-storage/)

<comment><USER5> Taken in context: low performance and low reliable storage space. So, way more than sufficient for a few simple things, and not much else. IndexedDB is massive overkill for lots of things, cookies have other problems for other things, localStorage fits nicely in the middle and should be used as such.

I have other reasons for disliking localStorage. Two tabs in e.g. Chrome (a few versions back, at least) can write to it and the contents from one tab can be delayed by as much as a second; one tab can read older-than-current data from another (A writes X then Y, B reads X); writes can interleave _at the string level_ , making it possible to produce garbage data (like "abc123def" when writing "abcdef" and "123" from different tabs) - when you add this to the delay and old data problems, it's sometimes undetectable and unfixable.

</comment></comment><comment><USER6> This is relatively cool, but that's not a great article.

<comment><AUTHOR> True. That's just a short blogpost, that I wrote mostly to let now our customers about new feature (really crucial for them). Suddenly hundreds of people are reading it.

While I'm super-happy and even more thankful for all the up votes, I'm a little bit ashamed that it's not a top-notch writing and in-depth analysis of the problem.

Anyway thanks Hackernews! Glad you like it. Local storage should be a must-be for any cloud app.

</comment></comment><comment><USER7> If you're working with local storage, I highly recommend using the following library:

<http://amplifyjs.com/api/store/>

It has a very simple interface and internally it has a bunch of fall-back storage mechanisms in case one isn't supported by the browser.

<comment><AUTHOR> Thanks!

</comment></comment><comment><USER8> Somewhat on-topic: interesting mobile networking piece with actual technical discussion (by Mike Belshe): [http://www.fiercedeveloper.com/story/mobile- networking-where...](http://www.fiercedeveloper.com/story/mobile-networking- where-html5-falls-short/2013-01-11)

</comment><comment><USER9> Well, that's exactly how Dropbox or Apple's iCloud work. Kinda standard these days

<comment><AUTHOR> Unfortunately it's not a standard in Saas tools e.g. wireframing apps.

</comment></comment><comment><AUTHOR> I've just updated the post with a comment of Jacek - our great programmer and author of this feature.

If you'll have any specific questions, we'll try to answer them :)

</comment><comment><USER10> Thanks for sharing. Cloud is very popular these days.</comment>


Use the same password on multiple sites safely - <AUTHOR> http://crypto.stanford.edu/PwdHash/ <comment><USER2> That's a cool extension, but I can't see it gain massive popularity. There is a class of problems with it that wfor a site ould be solved if you make it a bookmarklet (with a companion site): does it support your browser, what if you need to log in from a computer that doesn't have this browser extension?

The real problem is that if you are security-conscious enough to understand how this works and why you need it, you are not using the same password over and over again. E.g. I have a "weak" password that I use on HN and many other sites, but my mail and sites that involve (even remotely) money get an individual password each.

<comment><USER3> Personally, I'd like to see this become a feature of the HTML 5 standard. I'd also make it opt-out if you specify your doctype as HTML 5. That would certainly help drive adoption.

Who do I send that suggestion to? :-)

I love PwdHash because it is a relatively simple solution to a relatively complicated problem. This is just further proof that "secure by design" is the only real way to do security.

<comment><USER4> I understand the attractiveness of the convenience, but (perhaps it's just my paranoia) should one approach to security and how users handle it be _codified_ into a standard at this point: shouldn't we be concerned about what currently unknown weaknesses may fall to cracking approaches that develop within a few short years?

</comment></comment></comment><comment><USER5> This is a bad idea which has been implemented a half dozen times. It's vulnerable to using a dictionary attack to recover the master password from a stolen hash.

It's also a particularly bad implementation that uses a single round of HMAC- MD5, which is a kind of bizarre primitive to use for hashing a password in the first place.

<comment><USER6> You know that old saw about your friend putting running shoes on as an angry bear approaches--he doesn't have to outrun the bear, he just has to outrun you? This password hashing is kind of like that. Sure it's easy to break. But if you're running a phishing site, are you really going to go through the trouble to cryptographically attack this weird password that doesn't work on other sites, when you've already got a bunch of other people's passwords that do work?

For that matter, this solution is probably even more complicated than it needs to be. Just tack on the domain name wholesale to the end of the password, and you'll foil any automated phishing password script well enough.

<comment><USER5> > are you really going to go through the trouble to cryptographically attack > this weird password that doesn't work on other sites

Of course you are, because this password _does_ work on other sites. All other sites.

With a single high end CUDA capable graphics device you can blow through 500 million MD5 operations in one second. How many words are in an English dictionary? Less than that.

That's how weak this is. If you steal the password database from bigforum.com, you can attack all the passwords in parallel. If you crack a password, you can then log into their facebook, gmail, paypal, whatever. This scheme pretty much guarantees you can do that.

<comment><USER7> That assumes you know people are hashing (or more specifically, which few passwords are hashed out of this enormous database you've stolen). How do you tell a random password from a hashed one as an attacker?

</comment></comment></comment></comment><comment><AUTHOR> I just saw a .deb in the new packages that installs the pwdhash plugin for Firefox and thought it was a pretty neat idea. Perhaps only a tiny additional line of defense, but if site A is careless with my password, it's nice to know that someone can't easily login to my account on site B. Does this make sense or do you think it's just too much trouble for what it gains you?

</comment><comment><USER8> I like this idea, but (IMO) we really need widespread deployment of OpenID. If we had that, we wouldn't need PwdHash.

<comment><USER9> So that way, one password IS complete access to everything.

<comment><USER7> Yes, but at least that one password is not stored across a multitude of sites with varying security.

</comment></comment></comment><comment><USER10> Aside from whatever security weaknesses the specific implementation has, it would be very inconvenient to use this unless it became standardized, as you wouldn't be able to use any browser that didn't have the plugin (like on your mobile device) for secure sites.

<comment><USER11> From the pwdhash page: _"Occasionally, users want to login to their web accounts on machines where they cannot install browser extensions (e.g. at Internet cafes). In this case users can connect to our web site<https://www.pwdhash.com> where they are presented with one of the following forms, depending on whether their browser supports clipboard operations via script."_

(Of course, copy and paste is not exactly convenient in mobile browsers, but it's at least possible on most newer ones.)

</comment></comment><comment><USER12> This solution also misses the motivation behind using the same password on multiple sites: extreme laziness. Any solution that is even infinitesimally more difficult than just typing in something on the tip of your tongue is not going to solve the problem.

</comment><comment><USER13> I wrote an extension similar to this at <http://gregstoll.dyndns.org/~gregstoll/passwordhash/> but for some reason I'm hesitant about changing over to this scheme.

</comment><comment><USER14> I wish I could install it on Firefox 3.5. Or should I turn off the extension compatibility check and try it out?</comment>


Why You Need to Take 50 Coffee Meetings - <AUTHOR> http://www.bothsidesofthetable.com/2011/08/15/why-you-need-to-take-50-coffee-meetings <comment><USER2> It's very obvious, but also very hard. Hard because it isn't measurable in the short term, and hard because many engineers aren't wired for it. That said, technology leaders have to eventually overcome the introspection that made them successful in the first place.

It is easy to see how some of the greats in the tech industry do it. Look at Ron Conway - he is a perpetual networker, and one of the highest impact people around. Steve Jobs is another, creating his famous reality distortion field. Look at Demo Day - isn't this the culmination of a lot of networking on top of great product work?

One of the interesting aspects of social networking theory is that it is the people more removed from us who can help us the most. The people we are tightly linked to don't know that many people that we don't. The folks less tightly linked have the incremental connections we can't access ourselves.

Coffee anyone?

</comment><comment><USER3> The danger here is confusing activity with progress.</comment>


Ask HN: Accessing personal email on FAANG work computer? - <AUTHOR> I have a side startup that, occasionally, gets some email to my personal email. I'd like to also check my personal email on my work laptop, but would my IP for my startup get rolled into FAANG if I check my personal email? I'd only read my email, not send any email (i.e. conduct business) <comment><USER2> Don't do that. Have a personal phone and a work phone if you must, but don't cross the streams.

You _like_ owning your output, right? Don't risk it.

<comment><AUTHOR> Cool good to know!

Out of curiosity - do you just not check personal email at all at work? Or do you use your phone and don't connect to corporate wifi?

<comment><USER3> Personal phone. No connection to WiFi. Do not give personal email or phone to anyone at work.

</comment></comment></comment><comment><USER4> Read your employee handbook and IT regulations thoroughly; personal use of company equipment is almost always forbidden and doing so for profit doubly so. Whether looking at emails from your startup counts as the former or latter is subject to interpretation by HR and the legal department.

In practice, many (most?) people do check personal email and more on company equipment and nobody much cares ... unless, one day, the company has a reason to want to know what you've been doing (for example, because you had a side startup you haven't cleared with them first (check you employee handbook) or your manager randomly decides he doesn't like your face anymore) and then the rules apply full force and it's game over.</comment>


Tetrachromats: people who see colors invisible to most of us (2014) - <AUTHOR> https://www.bbc.com/future/article/20140905-the-women-with-super-human-vision <comment> andrewl-hn My spouse is a tetrachromat, and it's fascinating. Sometimes she sees patterns on leafs or bird feathers that other people don't see. Sometimes she can detect a very minor difference in colors of clothing items that other people see as identical. If a person wears those two items of clothing together she finds it really irritating.

She also sometimes see colors in her dreams that are outside of a pallet humans see in real life, but after she wakes up she can't describe them. It's not one color or one hue, there are several colors that she can only experience in her dreams.

<comment><USER2> I don't see why seeing an extended pallet in dreams would be a thing particular to tetrachromats. Unless trichromatic vision completely covers the gamut of naturally occuring wavelength combinations, which I doubt.

<comment><USER3> Colors like magenta (red and blue wavelengths together) are nonspectral, having no single wavelength they correspond to. They only exist as a mix, and we see a pinkish color that you can't write down as a wavelength.

Tetrachromats could plausibly see more nonspectral colors by activating their extra color receptor and one of the other ones. There would be no exact equivalent in trichromatic vision.

It depends on what their brains decide to do with it- maybe they would just land on an existing color in between. But there's no reason it _has_ to.

So these colors are something that tetrachromats could maybe see while awake, but usually with lots of other colors mixed in. Asleep, maybe the brain starts to play with them and generates pure versions of them. Trichromats wouldn't be very likely to have these dreams because their brains don't have experience of tetrachromat nonspectral colors at all.

<comment><USER4> Ah! Now I have theory: We trichromats have a hue circle, and magenta is the point where the lower and higher wavelenghts are joined. However this simple model breaks down for tetrachromats. Perhaps they have two hue circles orthogonal to each other. This means, hue becomes two-dimensional. Really crazy to imagine such a thing.

I imagine in school the teacher tells the poor girl: Mix the blue and yellow colors to get green, and the girl doesn't understand because she has a lot more complex color model than the teacher.

<comment><USER3> Here's a badly-worked out theory.

We see magenta as a separate color because we can distinguish it from green- it's not green, because Red and Blue don't activate our green cones. But we can't distinguish between spectral yellow and R+G because there's no yellow cone: the activations of all our cones are more or less identical in both cases.

If you have a yellow cone, you'd conceivably be able to distinguish between both kinds of yellow: redgreen and yellow _could_ look as different as green and redblue do. I'm not sure how that would look as a "wheel", perhaps a figure-eight with the crossing at yellow.

<comment><USER5> I think this is a very good explanation. You're emphasizing that a trichromat will experience the same activation of their cones to the wavelength of yellow light, and light containing the wavelengths of red and green mixed. So the spectra of these two colors will be different, but appear identical.

Whereas a hypothetical tetrachromat with an additional cone type that activates to the yellow wavelength, will have obviously different activations of their cones for the "wavelength of yellow" and "wavelengths of red and green mixed". And hence experience them as different colors.

I'm not familiar enough with the different definitions of color spaces to define how to model this. You could easily define it as a four-dimensional RGBY color space, but to my understanding the other color spaces are defined because they have better properties for combining different colors, or playing better with interpolation between colors.

It would be a challenge to come up with a good four-dimensional color space that is a useful artistic and visual tool, given that there are very few people around to evaluate it! And also because all computer monitors are trichromatic, so it'd be a job in itself to set up a test system.

I wish someone in the interview had asked some of these people how they experience photos on computers!

<comment><USER6> You can arrange the three colors in a triangle, which defines a plane, is treated like a circle in color theory, and looks like a weird stretched out "U" when put in a perceptually uniform space (stretched towards green, which we see best, and flat on the magenta side). Perceptual color spaces combine this with luminance, which is sensed by rods instead of cones.

Tetrachromatic colors could be placed in a tetrahedron, defining a space and being approximated as a sphere. A perceptually uniform representation would probably be curved on the three edges that agree with the spectrum and flat on the three that don't. Green is still probably the biggest. Then you'd add luminance as a fourth dimension because it's still rods.

<comment><USER5> Great explanation, thanks :)

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER7> There's actually a way for us to experience something similar: wear eyeglasses where the two lenses have different spectra. Then these "extra colors" show up as a shimmering sensation.

I have such a pair, but have to say it's not very exciting; there's not that much metamerism in the real world.

<comment><USER8> This is a really good idea. In fact it should be able to promote trichromats to hexachromats, since we have two eyes. I wonder if we could calculate optimal filters, sort of like EnChroma (enchroma.com) for trichromats.

Where did you get your pair? What filters did they have?

<comment><USER7> It was many many years ago, so I unfortunately don't have the details. But yes, the process should be quite similar to EnChroma.

</comment></comment></comment><comment><USER9> Maybe if this group grows over time we can finally move past the 24-bit color space that the mainstream has been stuck with for decades. I'm not a tetrachromat nor a woman, but I do routinely find myself bothered by the banding of gradients in the 24-bit color space. I went as far as asking Mozilla to consider adding a dithering algorithm to their gradients [1].

[1] [https://bugzilla.mozilla.org/show_bug.cgi?id=627771](https://bugzilla.mozilla.org/show_bug.cgi?id=627771) (note the linked example is from 9 years ago and the -moz-linear-gradient CSS attributes no longer work.)

<comment><USER10> I think that is entirely separate.

The 24 bits are 3x8. To accommodate tetrachromats, you'd go to _4_ x8, not 3x10.

<comment><USER11> I don't think there's any need to go to four primaries. If you keep just RGB but have more bits per channel you can widen the color space without getting banding while also representing many more colors. You just move the RGB primaries out to cover more space. Doing 3x32bit float is common to get you all the color resolution you'll ever need for calculations in image pipelines.

<comment><USER12> We could even go up to 2x64bit floats for even more definition...

Wait, that didn't make sense to you as a trichromat?

Neither does your suggestion to a tetrachromat. For them color is a four dimensional space (tetrachromat literally means "four-colorist"). The RGB cube becomes a RXGB hypercube. You can't emulate X with RGB like you can't emulate green with red and blue.

<comment><USER11> That will heavily depend on if the extra primary actually allows you to sample something significantly different from the other three or just gives you more color differentiation. My understanding was that human tetrachromats had their extra primary close to one of the "standard" ones and that gave them more color differentiation but not exactly extra colors.

<comment><USER13> It gives them more color differentiation in the same way your trichromacy gives you more color differentiation than a deuteranope.

</comment></comment></comment></comment></comment></comment><comment><USER14> My daughter has something like this. She can see colours nobody else can, but pays for it a little by not being able to see as much out of the corner of her eyes than most people.

One optician panicked so much at what she said they referred her to the hospital in case she was having a stroke! And that's when we discovered what she can do. I just thought she was good at picking clothes that went together well.

<comment><USER15> > I just thought she was good at picking clothes that went together well.

Good for her, but I doubt this is because she can "see colors nobody else can". If that was the case, she would most likely be _worse_ at picking colors which (to the average eye) goes together well. Maybe she just have good taste?

<comment><USER16> How do you justify the idea she'd be worse at picking colors that go together?

If you pick points that are close together in four-dimensional space (to make a simplistic analogy) they'll continue to be "close" in a topological sense under any linear projection to three-dimensional space. Or for a different analogy, if objects group together under a filtration, they'll continue to group together under a coarsening of that filtration.

<comment><USER15> "Go well together" is different than "close together" if we are talking about matching clothes. Color matching effects is based on distances in the color wheel. Closest together is boring, largest distance is jarring. If you imaging a new axis only visible to tetrachomats, the color matching effects appreciated to a tetrachomat will most likely not have the same effect or even be visible to regulars.

</comment></comment></comment></comment><comment><USER8> Are Antico's colourful paintings really a result of her tetrachromacy, rather than artistic flair? If she's painting such that the colours of the paint match what she sees, then trichromats should also think the paints match what they see, since they're less discriminating than she is.

<comment><USER17> Distorting colour is a standard post-Impressionist painterly technique.

But the moonlight painting gives it away. Most people don't see _any_ colours under low light, and being able to see and paint a colourful scene under those conditions is a unique ability.

Of course it could be imagination, but it doesn't look like it. The tree and the moonlight paintings have similar colours to the ones you'd see if you took a photo of a scene and turned up the saturation in Photoshop, with a few extra shades. It's a surprisingly literal and unimaginative form of exaggeration, and it's not how most painters distort colour for effect. So I'm more inclined to think it's a perceptual feature, not a creative choice.

</comment></comment><comment><USER18> I find tetrachromaticity fascinating -- particularly, I wish there were a way to scientifically prove whether tetrachromatics actually perceive colors as _qualia_ that the rest of us don't, because that is absolutely _not_ clear.

Let me explain: our eyes perceive RGB, but we don't in consciousness -- the RGB is mapped somewhere, long before consciousness, further in the brain to more of a perceptual RYGB -- a two-dimensional space of warm/cold (RY/GB) against "lighter/darker" for lack of a better term (YG/RB). See [1] for more info. Psychologically yellow functions as a primary color even though we don't have a rod for it. (In reality it's much more complicated than this, since we perceive saturation, brightness, etc. but this is a valid simplification for current purposes.)

So it's entirely possible that tetrachromats map their four rods to the _same_ RYGB box the rest of us perceive as qualia, only with a different mapping. Then, they can still distinguish between colors everyone else sees as the same (because different spectra), but they'll still _perceive_ them as the same color qualia the rest of us _perceive_ \-- colors in the world will just be mapped slightly differently. The closest (but imperfect) analogy I can think of is wearing polarized glasses -- same color gamut, but certain things "compare" differently now.

Or, does tetrachromacy somehow also change the perceived-qualia RYGB model itself? So there's, say, a 3rd axis beyond warm/cold and "lighter/darker"? Or the span of the two axes somehow becomes wider to accomodate more information? Or something else?

Hope this is clear. Perhaps it could be tested psychologically, though -- simply by asking participants to describe the colors they see qualitatively, to see if the words they use in color comparisons (e.g. warmer/colder) are the same as those used by the rest of us... or if there's any new "feeling" component involved.

[1] [https://en.wikipedia.org/wiki/Opponent_process](https://en.wikipedia.org/wiki/Opponent_process) \- "...the cells were widely called opponent colour cells, Red-Green and Yellow-Blue. Over the next three decades, spectrally opposed cells continued to be reported in primate retina and LGN."

<comment> EventH- Not sure what the justification is for saying Y functions 'psychologically' as a primary color. It would be a secondary color (R + G) in terms of the light spectrum, and (as you noted) our cones are directly most sensitive to RGB.

To answer the question, as qualia cannot be compared from person to person, there is in principle no way to show that they differ (or are the same) objectively. A sort of relative comparison of qualia within an individual (as you propose) will also not get you there, as it may be that the individual is simply more sensitive to changes along the gradient, not that they are experiencing a new color, and that's assuming we are able to use an objective comparison scale which we aren't.

<comment><USER8> > our cones are directly most sensitive to RGB.

The L cone is actually most sensitive to the yellow wavelengths.

<comment> EventH- You're right, thanks.

</comment></comment></comment></comment><comment><USER19> I saw a six color channel video system at SIGGRAPH some years ago in their emerging technology exhibition. I believe the developer may have been Sony, but could not find an online reference. The additional colors were approximately midway the R-B-G colors conventional used. They claim they could display more of the color that people normally are sensitive to. And they had a 6-color monitor side-by-side with conventional showing how nature scenes were more vivid in their system. Of course every part of the system had to double up: video camera, transmission, storage, display.

I do not know if subsequent technologies like OLED, Quantum dots, HDF capture much of the color increase of the six channel system.

I do not know if the six color system could be used to quantify tetrachromacy.

<comment><USER20> Quattron TVs tried this with a dedicated yellow pixel and weren't that good... I highly doubt we'll see something beyond RGB (unless it's a first class citizen from camera to TV)

</comment></comment><comment><USER15> I wonder how such people experience pictures, movies etc.? All color reproducing technology is based on the the three-color system.

I'm skeptical of the articles claim that the painting gives us any insight in how a tetrachromat perceive the world. This is just like claiming a color blind person would be able to perceive full-color vision by looking at a painting. Never mind that tetrachromat painters would have real difficulty finding the necessary color pigments to reproduce what they see.

<comment><USER8> >I wonder how such people experience pictures, movies etc.? All color reproducing technology is based on the the three-color system.

Presumably like trichromats experience Kinemacolor ([https://en.wikipedia.org/wiki/Kinemacolor](https://en.wikipedia.org/wiki/Kinemacolor)).

</comment></comment><comment><USER21> The title is misleading. The extra cone allows tetrachromats to appreciate individual colors that the normal optic system would "average" into a single hue. The visible spectrum is the same for tetrachromats: they cannot see infrared or ultraviolet wavelengths. These individuals see more color detail, not more colors.

<comment><USER13> > These individuals see more color detail, not more colors.

If you're not able to differentiate between colors you're not able to _see_ those colors.

Hell, your argument can be stretched to stating that there's no difference between monochromatic and trichromatic vision as long as the covered light spectrum is the same.

<comment><USER21> You misunderstand. Any trichromat could see those colors as well, they would just need to be much closer to the object in order to distinguish them. You are still thinking about them seeing more colors. They see more detail in color. Detail is not a matter of visibility but one of perspective. With a closer perspective you could see those colors as well.

<comment><USER8> I don't think that's true. Deuteranopic dichromats can't distinguish red and green by looking more closely.

<comment><USER21> Dichromatism is a disorder. Our brains expect a trichromatic signal and when it only receives dichromatic information the hues are "repeated" because a cone (usually the one responsible for green) is not available. In people with green-weak color blindness this makes green look like a "weak" reddish hue. Tetrachromats' brains are still expecting a trichromatic signal but they get more information than is expected. That means that the image contains more information or detail but the colors are not nee colors.

<comment><USER13> That's not how brains or vision work. The brain is not "hard-coded" for trichromatism. Were that the case we would not be trichromats in the first place.

<comment><USER22> Our brains are rather complicated, interesting things- and probably do something like wire themselves up to whatever "sensors" are available.

</comment></comment></comment></comment></comment></comment></comment><comment><USER23> I'd love to see a tetrachromat who also knows about scientific color theory (tristimulus curves, CIE XYZ color, chromaticity and whitepoints, ...) explain how the color science would looks for them (do they have 2-dimensional hue, and 3-dimensional chromaticity diagram?)

</comment><comment><USER24> I wonder if commonly available color changing smart bulbs, such as Philips Hue bulbs, have fine enough color control to be able to produce color changes that only a tetrachromat can see?

If so, that would be an interesting way for a tetrachomatic magician with a mentalism act to have their assistant pass them information. In particular, it would almost certainly work to fool Penn & Teller on their show "Fool Us" [1], where it often comes down to whether or not the mentalist can find a way to pass information that Penn & Teller can't spot.

[1] [https://en.wikipedia.org/wiki/Penn_%26_Teller:_Fool_Us](https://en.wikipedia.org/wiki/Penn_%26_Teller:_Fool_Us)

<comment><USER10> I'd be really surprised if the Hue internally doesn't just have three lights (R, G & B) that combines to produce all colors a human "trichromat" can distinguish.

To my mild surprise, 10 minutes googling did not find any description of how it works.

</comment></comment><comment><USER25> Does finding advantageous mutations like this give us a sort of blueprint if one day we wanted to artifically modify genes for these traits?

<comment><USER26> Adding genes for more opsins is interesting. However, the regulatory mechanisms for developing the retina and differentiating cone types appear to be quite complex.

</comment></comment><comment><USER27> 12% of women is not exactly "rare"! The fact that it did not come out before is telling.

It's interesting to notice how designing screens to use the RGB colors is very limiting for those people.

Imagine living in a world where 94% of people have the same form of color blindness and you don't.

People would randomly mix e.g. blue and green in every place and ignore your comments with a smirk.

<comment><USER28> 12% per cent of women is roughly 6% overall, that's quite rare. 94% of the population can't perceive this.

<comment><USER29> I don't think 1 in 16 is "quite rare." If you've got 100 people you know by name (and you likely have more), 6 of them have got this.

<comment><USER30> _May_ have this. Odds don't necessarily imply even distribution amongst a given sub-population. A person could know 1,000 people and still not know a single tetrachromat, and another person could know 10 people and know multiple tetrachromats.

<comment><USER29> No, 100 of 100 "may" have this.

</comment></comment></comment></comment></comment><comment><USER31> Is it possible that tetrachromat people may have a lot of trouble shopping for painting supplies? Since the dye or pigment used on the packaging may not be the same as the dye or pigment in the actual pastel/watercolour/whatever.

Wouldn't it be really confusing?

Are there lines of painting and art supplies specifically for tetrachromats?

</comment><comment><USER32> There is always a relevant XKCD. In this case, I've had this blog post rattling around my head for over 9 years.

[https://blog.xkcd.com/2010/05/03/color-survey- results/](https://blog.xkcd.com/2010/05/03/color-survey-results/)

</comment><comment><USER33> Super interesting. My notes as a colorblind man (might be misunderstanding some stuff though):

(Being a little sloppy with sex stuff here. Not all women have two x's, women can be colorblind too, etc.)

• Two of our usually-three cones are specified on the X chromosome

• When one of a woman's X's specifies an anomalous cone she ends up with a 4th, anomalous type of cone.

• This happens ~14% of the time for women.

• That's about the same percent as color blindness in men.

• That's not a coincidence. Because color blindness comes from one of these women's sons getting that anomalous 4th come instead of a typical 3rd cone. This anomalous cone tends to overlap more with one of the other cones in its range of perceived frequencies, which is what causes color blindness.

• But only a small percentage (not sure what percent yet?) of these women with 4 different cones actually seem to be able to perceive more colors

• that's because the 4th, anomalous cone might basically fully overlap with one of the typical ones in its perceived frequency range, so it doesn't really give the brain any additional info

• one question I have: so it seems like not all these anomalous cones are the same. Is there a fixed number of types? Or is it more of a spectrum? Further, are /all/ cones on a variable spectrum? Or is almost everyone's blue cone exactly the same?

• this was interesting: colorblind men actually have a set of colors they can distinguish that people with normal color vision can't (the article explains why)

• in this study they found colorblind men (but by looking at unusual things they /could/ see, not things they couldn't? Not sure) and then tested their mothers to see if they could see extra colors.

• Most of them couldn't. One of them could. The study was only like 9 people? Safe to say /all/ of these women had 4 types of cones, even though only one of them had a sufficiently non-overlapping fourth one to get some benefit?

• As a colorblind man, I've never noticed an ability to distinguish colors others can't. Only the opposite.

• it's intellectually neat to know that's possible, even if it doesn't tend to "come up" in everyday life.

• It souuuunnndssss like the amount of extra color vision that these tetrachromats get is only the same as the extra color vision /I/ get—that same "theoretically there, but doesn't seem to come up in everyday life" thing. That's a little disappointing—I though tetrachromacy was more kooky.

<comment><USER34> > Or is almost everyone's blue cone exactly the same?

I get a stronger blue channel from one eye than the other. So I'm quite sure that there is variability, it's a matter of degree. Also, research into language and culture shows that the brain is heavily influenced by colour as well. Some cultures have difficulty seeing differing shades of blue or green that westerners think are trivial.

</comment></comment><comment><USER35> What would be a good source of tetrachromat images ? Would love to train a model and "see" what these women see !

<comment><USER8> [https://www.dpreview.com/articles/1471104084/sonyrgbeccd](https://www.dpreview.com/articles/1471104084/sonyrgbeccd)

Alternatively take photos with a normal camera and then with the same camera with a coloured filter. Choose the filter so that it only partially interferes with each colour of sensor (magenta should work well). Then the two images have _six_ independent colour channels between them.

</comment></comment><comment><USER36> At what point would it be worth accommodating to these tetrachromats?

Sensors, displays, software.

Unicode encompasses vast numbers of characters, wouldn't an update to colour science and displays be in order?

<comment><USER37> When they're well into the double-digit percentage of the population, I guess. (Not just _technically_ tetrachromats but actually able to discern a 4-dimensional color space).

Since they can perceive _more_ colors, it's never an accessibility issue, so it's far more important to accommodate dichromats, and that's already very hard because we can't tell how a person with a different set of cones would perceive a particular color just by looking at it.

Also, we already have a color model that can't reproduce true cyan as perceived by "regular" trichromats, and so far that hasn't been a real issue.

<comment><USER38> What is the problem with cyan? That there is no adequate color space that can create more or less cyan? I would think it is just a mix of green and blue, no?

Is the same true for magenta as well? Is it a problem to convert between RGB and CMYK?

<comment><USER8> RGB only spans a triangle within the full colour space [https://en.wikipedia.org/wiki/Wide- gamut_RGB_color_space#/me...](https://en.wikipedia.org/wiki/Wide- gamut_RGB_color_space#/media/File:CIExy1931_AdobeWGRGB.png). So the cyan generated by blue and green isn't as saturated as it could be.

<comment><USER39> For anyone puzzled by the graphic's D50 whitepoint marker being in yellow, offset from the color background's whitepoint (the white intersection of the 3 "arms"), yeah, that's wrong. There's historically been a lot of broken chromaticity code out there, and associated flawed diagrams.

</comment></comment></comment></comment></comment><comment><USER40> One on my buddies wives can see ultraviolet. It's sort of incredible, she describes it as a very dark blue to white with brighter sources

</comment><comment><USER41> I vaguely recall an SF short story about a genetic or nanotech hack for becoming a tetrochromat. Either by Greg Egan or Hannu Rajaniemi.

</comment><comment><USER42> Is there a reliable online test for tetrachromacy?

<comment><USER13> Probably not: colors are pretty much always expressed in terms of RGB (at the "standard" trichromatic peaks"), and displays work in those terms. So you couldn't _express_ the colors in questions, nor could you have the display show them.

<comment><USER43> Outside the on-line/web sphere, there are quite a few other ways to express (or specify) colours, but alas, they all seem to have been made by and for trichromats ;-}

</comment></comment></comment><comment><USER44> I have always found describing color shades interesting/mind-fuck. Does the "red" that you see "red" to me? I am red-green color blind and a lot of "red" looks "brown" to me.

<comment><USER45> Color doesn't actually exist. We don't see actual objects as they are, we see the light that bounces off of them. Brains will create their own way of mapping wavelengths to colors, so therefore we do not see the same thing, but we perceive it as the same.

If I opened your brain and swapped your red with blue, you would not notice.

<comment><USER21> Color does exist. The wavelength of light that is reflected by an object is its color. That wavelength can be measured objectively.

<comment><USER10> Yeah, but all real light is a mixture of a _lot_ of wavelengths that our retinas filter down to three aggregates of "red", "blue", and "green".

</comment></comment></comment></comment><comment><USER46> Birds have 4 primary colours and six secondary colors...

</comment><comment><USER41> Personally, I'd rather see further into the IR.

</comment><comment><AUTHOR> Summary: About 12% women have a mutation due to which they have 4 cones instead of 3 in their pupils. Most of the time the extra cone has an activation curve so close to another existing cone that it makes no practical difference.

But in rare cases extra cone has a quite unique activation curve and allows to differentiate mixes of wavelengths that are perceived as the same color by most people.

More in-depth explanations: [https://theneurosphere.com/2015/12/17/the- mystery-of-tetrach...](https://theneurosphere.com/2015/12/17/the-mystery-of- tetrachromacy-if-12-of-women-have-four-cone-types-in-their-eyes-why-do-so-few- of-them-actually-see-more-colours/)

<comment><USER47> In their pupils?

<comment><USER48> Rods and cones are in the retina, which is the inner lining in the back of the eye. You see the retina when looking into pupils.

</comment></comment></comment><comment><USER49> If men were the ones who had this the tenor of dismissiveness sprinkled across our comments would be transformed into the desperate attempt to convince that we all had this

</comment><comment><USER50> 100x is sensationalist phrasing. ~7 more bits of color resolution better way to think about it.

<comment><USER51> I don't know where they get the bit count from, it seems to be based upon an understanding of the cone's operation that I've never seen justified in any of these articles.

Assuming that the cones of different frequency range have approximately the same degree of sensitivity, I'd be thinking that the number is about n^(4/3) where n is the number of colours perceivable by trichromats.

But even if that's true - which I doubt - the additional colours are in unlikely to have a useful distribution, and will be centered around the frequency response curve of the fourth cone (I believe it's generally in the yellow spectrum; somewhere between red and green).

<comment><USER8> If you wanted to measure it in a principled way you could count how many colours they could _distinguish_. [https://en.wikipedia.org/wiki/MacAdam_ellipse](https://en.wikipedia.org/wiki/MacAdam_ellipse)

</comment></comment></comment><comment><USER52> 100x more colours is just nonsense. Trichromacy is already sufficient to see _all the colours_. The only difference is that some things may look like they are a different colour (which means they might be able to distinguish two objects where tetrachromats can't).

</comment><comment><USER53> On a related note, when you see purple, your brain falls over, because it's actually seeing something it thinks should be green, but knows it isn't.

[https://toughcompetent.com/blog/purple-doesnt- exist/](https://toughcompetent.com/blog/purple-doesnt-exist/)

<comment><USER54> Not a promising opening:

> Whilst we can see violet and blue next to each other, there's no purple. > Because purple doesn't exist.

Back in reality, "purple" and "violet" are synonymous.

The article also makes the completely unsupported assumption that the color you "should" be seeing when you look at a mixture of wavelengths is the color of the average wavelength of that mixture. That's how it decides that purple "should be" green. But that's nonsense.

> When you see red and green for example, the L and M cones both fire, and > your brain interprets the result as something near both. And what's near > both is yellow. So even though there's no yellow light entering your eye, > your brain imagines the result as yellow, because both cones are being > stimulated in similar amounts.

This gets the causality backwards. When you see red and green, your L and M cones both fire. And you interpret that as yellow, _because yellow is what you perceive for that pattern of cone activation_. To the brain, cone activation patterns are all there is. The question "what single wavelength would best approximate this activation pattern" is not even part of the model the brain is working with. But, obviously, if there is a single wavelength that approximates the activation pattern of a mixture, you'll perceive those two things as being similarly colored. Is it necessary for the single wavelength to be the arithmetic average of the wavelengths in the mixture? No.

<comment><USER55> > "purple" and "violet" are synonymous

Except when they're not. People who have to think and talk about color on a regular basis, such as artists, sort colors into much more detail than people who don't.

Have a look at the Wikipedia pages for purple ([https://en.wikipedia.org/wiki/Purple](https://en.wikipedia.org/wiki/Purple)) and violet ([https://en.wikipedia.org/wiki/Violet_(color)](https://en.wikipedia.org/wiki/Violet_\(color\))). The image examples given for purple range widely, from a photo of some grapes I would call more blue than purple, to a dress that I would call magenta at best. And a color swatch that is somewhere in the middle of that range.

Meanwhile the page for violet leads with a specific wavelength, and a set of photos that are all very close to the swatch above them. This particular color could fit into the range of colors given as examples of "purple", towards the bluish end of the range.

</comment></comment></comment><comment><USER56> Maybe they're like the mantis shrimp, who can see 16x more spectrums of light than we can.

[https://theoatmeal.com/comics/mantis_shrimp](https://theoatmeal.com/comics/mantis_shrimp)</comment>


Developers Are Already Making Great AR Experiences Using Apple's ARKit - <AUTHOR> https://net.xyz/2017/07/10/developers-are-already-making-great-ar-experiences-using-apples-arkit/ <comment><USER2> There's no way you can talk about ARKit without showing off the measuring tape apps

[https://youtu.be/z7DYC_zbZCM](https://youtu.be/z7DYC_zbZCM)

<comment><USER3> Wow - how does it do that?! Image recognition techniques alone (as far as I know) couldn't do that, right? So how does it know how far away something is?

<comment><USER4> My guess is they estimate one or several dominant scene planes from the sparse triangulated feature points and get scale through incorporating accelerometer measurements.

</comment></comment></comment><comment><USER5> I've seen several very creative demos but I'm still struggling to see practical applications. It seems like massive, every day adoption of this kind of AR is going to have to wait for dedicated glasses.

Maybe I just lack imagination.

<comment><USER6> Maybe point it at a sports game for stats and game data?

Point it down the street to have great restaurants highlighted?

Point it at the sky to get astronomical facts?

Point it at tourist landmarks to find out about them?

Point it anywhere to see where athletes/runners/cyclists have run and in what time?

Visualise all historical car accidents at a given location?

Visualise all hidden infrastructure, underground gas lines etc?

See history overlaid on the present?

Visualise public transport routes?

Show "upcoming events at this venue" as you pass theatres, cinemas, stadiums?

<comment><USER7> > Point it down the street to have great restaurants highlighted?

on android early on (before 2.3!) yelp called it lens, and had a monocle icon. google maps and nokia apps also had it at some point I think. and no better implementation will ever make it less useless.

it was a uter useles gimmick. everyone tried it exactly once.

<comment><USER8> It was on one of the early versions of the Yelp iOS app as well. Don't really remember if it was there on day one, but I remember playing around with it in iOS 2 or 3.

<comment><USER9> It was called Monocle, and it's still there, under More (on the version of the app I have installed).

</comment></comment></comment></comment></comment><comment> King-Aaron Some of these are genuinely brilliant - I love the video of "testing" a cushion on your own couch before you buy.

<comment><USER10> Yes , the biggest problem for me and wife has been to visualize how the new furniture we are buying will look inside our house. AR can solve lot of those problems to some extent

<comment> King-Aaron I can see benefits in the interior paint industry, and the flooring industries too. Being able to 'preview' tens of thousands of dollars worth of tiles (for instance) would be a real benefit, especially if you operated an interior design company etc.

</comment></comment></comment><comment><USER11> Very cool tech but the phone as viewport seems like a fairly large step backwards in my opinion.

<comment><USER12> Depends on the use application. For observing especially large objects[1][2], I agree, it would be very hard to use for anything beyond a quick demo. But on the other hand, I think the phone is a perfect viewport for on-the-fly smaller applications, like an AR measuring tape[3], adding info about artwork in a museum, displaying a virtual prototype of a dish on a restaurant's menu[4], translating street signs on the fly[5], etc. The phone is perfect for applications where you don't want to plan ahead or be constantly carrying an extra piece of equipment around.

1: [https://twitter.com/madewithARKit/status/880815805281300480](https://twitter.com/madewithARKit/status/880815805281300480) 2: [https://twitter.com/madewithARKit/status/880056901987254272](https://twitter.com/madewithARKit/status/880056901987254272) 3: [https://www.youtube.com/watch?v=z7DYC_zbZCM](https://www.youtube.com/watch?v=z7DYC_zbZCM) 4: [https://twitter.com/madewithARKit/status/880744158423658497](https://twitter.com/madewithARKit/status/880744158423658497) 5: [http://newatlas.com/google-translate- update/35605/](http://newatlas.com/google-translate-update/35605/)

</comment></comment><comment><USER13> Seems Apple solved monocular SLAM problem before attempting VR.

Wonder if they used FPGA or anything to speed up the algorithm? In my experience SLAM takes too much computation power and/or release too much heat.

<comment><USER14> SLAM?

<comment><USER15> [https://en.wikipedia.org/wiki/Simultaneous_localization_and_...](https://en.wikipedia.org/wiki/Simultaneous_localization_and_mapping)

</comment></comment></comment><comment><USER16> This is awesome! I can't wait to start playing around with this :)

</comment><comment><USER17> Took me a while to realize that two guys playing basketball were actually Virtual

</comment><comment><USER18> Has anyone played with the ARKit yet to develop? Will be great if you can share your experience. I have made couple of games on Unity and want to dive into mixed reality applications.

<comment><USER19> Looks like someone has already made a Unity ARKIT plugin

[https://www.assetstore.unity3d.com/en/#!/content/92515](https://www.assetstore.unity3d.com/en/#!/content/92515)</comment></comment>


How to sell your side-project/startup? - <AUTHOR> Hey guys,
A lot of times makers/founders want to sell their business, but don't really know how to do it without later regretting it. Sometimes it's because they sell it to the wrong person (someone who's just looking to resell it in a few months) and sometimes it's because they feel like they didn't sell it for a good enough price (mostly happens when they accept the first offer as soon as they hear it). There are a few marketplaces to help facilitate this process for the founders, but honestly most of them care only about making a sale, mostly because they get a cut.
I started Soochi [1] to solve this exact problem: Help founders sell their projects/startups without having them regret it later.  At the risk of not stretching this post to a blog post's length, I'll just link this Medium post [2] I wrote introducing Soochi, and explaining how I see things working with Soochi.
I am really hoping Soochi succeeds at solving the issues makers/founder currently face with the current options, and would love to hear any feedback, or answer any questions that you may have about the site.
[1] https://soochi.co [2] https://medium.com/p/soochi-d32221e4a180 <comment><USER2> This is soochi advertising disguised as question. Can you add the company name to the title like in previous submissions? (e.g. [https://news.ycombinator.com/item?id=15621579](https://news.ycombinator.com/item?id=15621579))

<comment><AUTHOR> The post you linked to was a Show HN post. This is a discussion posts for people to share similar stories, or give feedback on Soochi.

I could have easily deleted the previous post, and do a Show HN again, but I didn't because that'd be spamming. Please understand that HN is a community where people can discuss anything related to tech. This post doesn't violate any HN rules

<comment><USER3> It's ok to submit your own stuff here, but if you ask questions where (one of) the answer is your product, many people will feel that it's a disguised ad.

Also:

> _I could have easily deleted the previous post, and do a Show HN again, but > I didn 't because that'd be spamming._

From the FAQ: [https://news.ycombinator.com/newsfaq.html](https://news.ycombinator.com/newsfaq.html)

> _Please don 't delete and repost the same story, though. Accounts that do > that eventually lose submission privileges._</comment></comment></comment>


Amazon cloud networking outage affecting Atlassian, Twilio, Slack - <AUTHOR> https://www.cnbc.com/2018/03/02/amazon-cloud-networking-outage-affecting-atlassian-twilio-slack.html <comment><USER2> Coincidentally, I needed to create an account on Bitbucket during this outage, to reply to a thread, and got my email completely locked out.

What I found out is that Bitbucket has a login wall for its support system. To the point that firstname.lastname@example.com is explicitly devnulled and tells you to log in to their support site.

Congratulations Atlassian, you played yourself. This is some dailywtf material.

Stuff like this makes me especially upset because feeding in emails to a support site is a problem _Atlassian 's own fucking software solves_. What a joke.

</comment><comment><USER3> * and amazon alexa apparently...</comment>


Show HN: our webcomic about how we made our first iPhone game - <AUTHOR> http://noisytyping.com/the-making-of-alphabet-connection/

<comment><AUTHOR> I'm the developer and (first-time) comics artist. Instead of the traditional blog, we distilled our notes into this webcomic.

I'm a big fan of Scott McCloud's books (Understanding Comics, Reinventing Comics, Making Comics). I hadn't drawn any long-form comics before, and drawing people is still hard/scary. I had a few books lined up on the process of making comics but no time to read them, so I just bit the bullet with a copy of Manga Studio and drew it. It took a little less than a week.

Comments are welcome.

Sales data: 3600+ downloads in the first 2 days, a little IAP.

This comic is not intended (or likely) to have much of an impact on sales. We just wanted to get our story out there, and hopefully a few less "developers got greedy" App Store reviews.</comment>


AWS or shared hosting for a new app? - <AUTHOR>

What do you guys do for hosting when releasing a new site/web app?
Do you take the time to tailor your app and environment for AWS (EC2, S3, etc), or do you prefer a simpler approach such as a shared hosting account with Slicehost/Linode/etc to just get it out there quickly?
I've never used AWS, so I don't know how straightforward or convoluted the initial process is to release a brand new site on it. However, this thread seems to believe that it isn't particularly complex, provided you're thorough and have a decent amount of *nix sysadmin experience: http://news.ycombinator.com/item?id=202056
OTOH, this post seems to suggest that shared hosting is preferable for releasing a "small" site, and that AWS should be considered later on, when your traffic requires it: http://news.ycombinator.com/item?id=258761
What say you? <comment><USER2> My personal approach is a mix of both.

With my startup(s) we plan to release on a shared hosting at first (alpha) before moving to a single dedicated server (beta) and then later (assuming it takes off) to EC2 (probably).

I've always maintained: if you plan to at SOME point be utilising AWS then you need to plan that into your app. All the code we write is scalable and modular - so things that wont work on the next step up can be pulled out and replaced with bits that will w/o breaking the overall system (memcached is a good example - we have a _fake_ caching layer on top of our database layer at the moment so that memcached can be added in later :)).

</comment><comment><USER3> I use both Linode and AWS, and I find both easy to administer.

I would say AWS has a mildly steeper learning curve (various AWS command line utilities to install, etc.), but nothing I found difficult.

A really nice thing about AWS is that you can pick and choose which AWS services you want to use. For example, suppose you were doing a backup app where wanted to securely store terabytes of customer data, but the server requirements were really light. You could start off with a $20/month Linode server and store the data in Amazon S3. Then later you could move to EC2 at $70 per small server per month if you needed it.

Or, on the other hand, if you knew that you were going to need lots of servers sooner or later, and you have enough money that the price differential doesn't make a difference to you, you might start off with AWS to avoid needing to do a switchover later.

I'm working on an app of my own now, and I'll be hosting it on Linode to start off with. Then, if it becomes popular, I'll be able to measure what my server requirements are, and I'll be able to easily move it to EC2 if I decide to. (Though my app though isn't doing anything cpu intensive server side, so I wouldn't be surprised if I can run if off of a single Linode server for a long time).

</comment><comment><USER4> I still stand by the comment I wrote 135 days ago in the second topic you cited above.

AWS is a good way to add or expand capacity to an existing "static" server. Last time I looked at the pricing, for a moderate volume site, AWS is more expensive than a comparable semi-shared sort of server arrangement.

</comment><comment><USER5> I'd use AWS only if you are intending to have your app auto-scale from the start. Aside from that, it's not worth the extra expense (about twice the cost of a comparable Linode) and hassle (you must manage S3 backups, at the least... or lose everything when a shutdown/failure occurs). Start on shared hosting and if you need more room horizontally, you can always move the app to AWS later, when traffic justifies it.

<comment><USER3> I don't disagree with your comment overall, but specifically on the point of backups: backups are far and away much easier on EC2 compared to other hosting providers with now that Amazon has the new Elastic Block Store feature... need a backup? Take a snapshot, you're done.

</comment></comment><comment><USER6> I've been on AWS for almost a year now. We haven't yet needed the real benefits, which is the potentially easy scaling.

If you're starting out and don't see yourself getting INSANE load requests in your first several months then I would go with slicehost, as it is much simpler to get started with.

</comment><comment><USER7> BTW, Slicehost/Linode/etc is VPS, not shared hosting.

</comment><comment><USER8> AWS is rather expensive in my opinion. Go with a shared host, get a sense of your traffic/revenue, then graduate to a dedicated server.</comment>


Ask HN: Someone registered trademark for the name of my product - <AUTHOR> Hi there,
Last month I released a new web product. Let's call it "Foobar" (the original name is something else). My product already has users, it has an ad video, it'll soon be in app store, too. The domain name "foobar.com" is taken by a Canadian company though. It's parked, and has a form of "submit offer if you want to buy it". I thought the domain name was for sale. My product is on another domain name, something like "getfoobar.com".
Today I just realized, that Canadian company who owns the domain name already registered the trademark in Canada without the product released, and also pending trademark application in US. So the name of my product is registered under another company. By the way, we're talking about a shady loan company, not a software company.
What should I do in this case ? I don't want to change the name of product because my product is already released and <comment><USER2> Get some advice from an IP lawyer. You may want to read this first:

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

From my understanding (as a non-lawyer), trademarks in the US are domain- specific, so someone having a trademark for a Foobar loan company might not prevent you from getting a trademark for software called Foobar, assuming your software has nothing to do with loans or finance and there would be no confusion between the two products.

A lawyer could tell you if you should try to register a trademark for your product under the Foobar name.

<comment><AUTHOR> They registered the domain name for a HR software. They are a loan company though.

</comment></comment><comment><USER3> Apparently they also have HR product offerings/software or are going to be going in that direction.

Is your product an HR product? If it is and they obtain the trademark registration of that product name for their HR product, they will have every right to prohibit your use in order to avoid unnecessary confusion. If it is only in the application process you can submit information to the USPTO showing that you have been using that name prior to them (the key here is proven prior use). That does not necessarily mean you will be able to prohibit their registration but if you can show prior use of the same name then the USPTO may allow you to continue to use that name, but that is not likely a wise course of action on a new product you hope to grow. You would subject your project to confusion and it does not sound like this is the type of business you would want your customers to think you are affiliated with or worse, you and that company are one in the same.

It would be wise to talk to an aiP attorney but you can do a great deal of online research regarding these types of conflicts. Unfortunately your situation is not that uncommon and the end result will probably be that you will need to change your name if you also have a HR software or a software product.</comment>