Cockroach Labs Gets $87M in New Funding - <AUTHOR> https://www.theinformation.com/briefings/2e28f3 <comment><USER2> We recently migrated a few small systems to CockroachDB (as a stepping stone). Overall, the experience was positive. The hassle free HA is a huge peace of mind.

I know people say this is easy to do in PG. I have recently setup 2ndQuadrant's pglogical for another system. That was also easy (though the documentation was pretty bad). The end result is quite different though and CockroachDB is just simpler to reason about and manage and, I think, more generally applicable.

But, on top of the well-documented postgresql incompatibilities, we have run into other issues.

First, and probably the reason you should stay away from CockroachDB's community edition, is the poor story around backups. You only get full backups. They are very slow to take and very slow to restore. There are even cases where it can fail to backup ([https://github.com/cockroachdb/cockroach/issues/28948](https://github.com/cockroachdb/cockroach/issues/28948)).

There are a lot of little bugs, which isn't a huge deal, but it's hard to find and you can spend a lot of time looking into it. Just yesterday we noticed that queries that use now() can't use indexes. Searching github's thousands of issues for "now() index performance" I get ~500 hits. Thankfully they are fast to respond to questions on slack / forums. But they _really_ need to clean up the hundreds (thousands?) of little bugs - some of them have been around for years. Most of them are near-non-issues, except for the time you waste looking into it.

Finally, performance seems worse than it could be. Running in single-node-mode with an _in memory_ database (for our integration tests) is still slower than postgresql. Restoring a 150mb dump file (just a bunch of inserts) takes over 2 minutes. But it's more than fine for the CRUD kind of thing we're doing.

<comment><USER3> This has been pretty much my experience as well.

The killer features are definitely the HA and the region-based sharding, but the backup situation and bugs are a real bummer. Not a total dealbreaker, but teetering right on the edge.

We are looking closely at moving to FoundationDB at some point.

<comment><USER4> > We are looking closely at moving to FoundationDB at some point.

I'm curious to better understand the use case where this change makes sense.

CockroachDB does a lot more than FoundationDB. FoundationDB is pretty much just a KV store. There are layers out there but they IIUC they have immature drivers. Have you had success developing applications on top of any of them?

Do features like secondary indexes, joins, or constraints matter for your use case?

A big thing cockroach does that foundation doesn't help with at all is contention. If transactions contend in foundation, they will fail with retriable errors at commit time. The process of coordinating concurrent read- write and write-write interactions fall onto the layer implementer. This is a huge burden. Cockroach has an increasingly advanced story around concurrency control. It's a problem which should not be understated.

Other important properties are:

      * Rolling upgrades
      * Long-running transactions (they are starting to have a story about read-only transaction with the new storage engine)
      * Online schema changes coordinated by the system.
      * FoundationDB has a nascent story around multi-region which seems doomed to poor performance and even then only exists to provide higher availability at the cost of synchronous replication (i.e. there is no geo-partitioning).

I don't want to sound overly critical about FoundationDB. It's a very cool piece of software for a single-region, scale-out, consistent KV that, for right use-case, which is low-contention or externally coordinated, can probably deliver a high degree of predictability.

edit: I work on CockroachDB.

</comment></comment></comment><comment><USER5> Perhaps the blog post from the company is a better link

[https://www.cockroachlabs.com/blog/cockroach-labs- raises-87-...](https://www.cockroachlabs.com/blog/cockroach-labs- raises-87-million-of-new-investment-capping-a-year-of-exceptional-growth/)

</comment><comment><USER6> At my last company, we had a great experience using postgresql flavored Aurora, especially because we could use recursive CTEs to do deep traversal of graphs.

Since CockroachDB is SQL, what would be the benefit over using Aurora?

<comment><USER7> Afaik, Postgres flavored Aurora has a single master for writes and doesn't allow horizontally scaling writes[1]. I believe reads can scale by bringing up multiple read replicas. Cockroach DB is "distributed SQL" so writes are also scaled across multiple nodes.

You can see some details about how this affects write perf in this blog by another distributed SQL database which compares the three databases (YugabyteDB, Aurora and CockroachDB) - [https://blog.yugabyte.com/comparing- distributed-sql-performa...](https://blog.yugabyte.com/comparing-distributed- sql-performance-yugabyte-db-vs-amazon-aurora-postgresql-vs-cockroachdb/)

[1] There is also multi-master Aurora (but based on [https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide...](https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora- multi-master.html#aurora-multi-master-architecture) that only supports 2 read- write masters and has other limitations).

</comment></comment><comment><USER8> Note that the marketing might make you think it's a drop in replacement for Postgres, and while it is very impressive, it lacks many common features and some are just different enough to be confusing.

The first difference I ran into was ALTER TABLE commands could not modify the datatype of a column. (It should be added soon.)

Your app probably won't "just work" \-- yet.

But IMO this is the coolest open source database with a bright future.

</comment><comment><USER9> We haven't tried cockroach yet because we are still on RethinkDB and are scarred by the experience of them going out of business.

I hope someday I'll be comfortable enough to experiment and use something other than postgres.

<comment><USER10> Such a disappointment RethinkDB ended up being. Converted over my side projects quickly after that went South.

</comment></comment><comment><USER11> Non paywall link - [https://techcrunch.com/2020/05/05/cockroach-labs- scores-86-6...](https://techcrunch.com/2020/05/05/cockroach-labs- scores-86-6m-series-d-as-scalable-database-resonates/)

</comment><comment><USER12> Aside from growth-oriented activities, are they in the black yet? Like could they be sustainable if needed?</comment>


Hard Numbers on Stackoverflow Careers - <AUTHOR> http://www.cforcoding.com/2009/12/hard-numbers-on-stackoverflow-careers.html <comment><USER2> First: you're missing all the users with less than 1000 reputation that have paid for CVs. There are actually about 1500 paid CVs in the system.

Is there critical mass? I would say, in major tech/development areas, or for national-footprint employers who relocated candidates, absolutely yes. A company like Google, Microsoft, Pixar will certainly find plenty of good candidates on Stack Overflow.

In smaller cities without big tech industries, and for people who don't want to relocate, mostly the answer is "not yet" although I expect to get there. The little startup in Tulsa that needs an embedded systems programmer but doesn't want to relocate someone... won't find them. The guy in Oklahoma City who won't move elsewhere isn't finding good tech jobs because there aren't any in Oklahoma City, not because we don't have critical mass.

As for the revenue, earning money was never the point of charging job seekers. We charge job seekers a minimal amount because it eliminates a huge number of unserious, unqualified, and other candidates who really don't stand a chance. If it's free, job seekers have an incentive to post their resume everywhere "just in case" which employers hate, because they have to filter through lots and lot of junk. We're actively looking for better ways to do this kind of pre-filtering. I'd like to lower the cost as much as possible without opening the floodgates, and I imagine we'll find creative ways to let high-rep stackoverflow users get a CV without paying very much. Nothing is set in stone.

<comment><USER3> > earning money was never the point of charging job seekers

Really? Why don't you give all the money to charity then Joel?

<comment><USER2> That's not a bad idea, actually, I'll talk to Jeff about that.

<comment><USER3> Actually, if you really make that little money out of it, the publicity stunt of giving it all to charity might be more profitable in the long term than keeping it to yourself.

<comment><USER4> Translated: Hey Joel, I'll always suspect your motives regardless of what you do even if it's a binary choice so you can't win. What does whether or not Joel is doing this for the money have anything to do with whether or not StackOverflow Careers is a good or bad thing?

<comment><USER5> Exactly, some nice false dichotomies going on here. Also: what's the sin in making money while also helping programmers get better jobs, regardless of whether or not that money is the primary goal or a side effect?

<comment><USER6> Have you read the article _describing_ the problems implicit in SO careers? Also, look at <http://news.ycombinator.com/item?id=997068> the high post on this thread.

</comment></comment></comment></comment></comment></comment></comment><comment><USER7> I know this is going way off topic, but I've been meaning to ask this somewhere. My knowledge is a little rusty (~8 years back I worked for a software development company that wrote recruitment software), but it was my understanding that, at least under UK law, you were not legally allowed to charge candidates to upload their CV or to search for jobs. Is stackoverflow careers open in the UK? Does this law not exist in the US or other countries?

edit: Sorry, I see <http://news.ycombinator.com/item?id=997197> asking the same question.

</comment><comment><USER8> The one person who definitely should be hired from Stackoverflow Careers is the one who teaches Jeff how to make back-ups and check that back-ups have been made properly.

</comment><comment><USER9> Looking at Stackoverflow Careers from a hiring perspective, I don't really understand the point.

If suddenly 20% of my candidates have a CV that includes some "reputation" score, and other information from a programming website, what am I to do with that?

Does it mean they spend time on stackoverflow instead of working? Does it mean they're a genius who knows all? Does it mean they simply ask and answer a lot of simple questions, but are useless on complex matters? Do I really want to try to figure that out?

In the end, I want to do apples to apples comparisons, and I'm not sure how SO Careers fits in there.

Are there suggested Best Practices for how to integrate SO Careers into a candidate search? Perhaps somebody can enlighten me if I'm missing something, but I don't get it.

<comment><USER10> If you have a candidate with a good CV and he's given you his stackoverflow account name, then it should take you about 5 minutes to get a good idea of how much time he spends on the site, what kind of questions he asks/answers and how well those questions are asked and answered. What you want to do with information is course totally up to you, but I fail to see why having that information is in any way a bad thing.

I agree that a raw number means very little, but the info gleaned from looking up their stackoverflow account can tell you quite a bit.

<comment><USER9> Stackoverflow Careers is based on the premise that it's worth $5,000/yr to me, plus $99/yr/candidate for the candidate, to share that information.

Do you really see that much value, versus simply asking all candidates 'Are there any publicly accessible technical forums or mailing lists that you participate on a regular basis? If so, are you willing to share your username?'

I prefer the latter, because it's a question I can ask _all_ candidates, and it doesn't cost me $5,000 to ask. Nor does it cost you $99 to answer.

<comment><USER10> I guess it's a perspective thing. To me it seems more like you're paying $5000 to get access to CVs by programmers who are dedicated enough to the whole job hunting process and secure enough in their ability that they're willing to pay $100 just to list their CVs. The stack overflow score seems fairly incidental to the whole process.

<comment><USER9> Again, I'm simply not buying the argument.

The reality is that I'd never _just_ use StackOverflow to find candidates, so these are people who have other ways to find out about the positions, and apply.

I'd rather see the candidate spend the money on an ACM membership (or similar professional development) than spend it simply trying to reach me.

That said, I think I now have a pretty good idea of the value proposition as it might exist for other employers, but it seems clear that the equation doesn't balance for me. Thanks for clarifying your argument, I appreciate it.

<comment><USER11> I bought ACM membership. They never sent me the monthly CACM on time (8 months before receiving 6 issues in a box(!!!) in the mail, then 1 more 3 months later, still missing 5), _and_ they sold my address and now I receive junk mail advertising academic books.

Joining ACM: just a plain bad idea. Only value is older papers not available ungated on citeseer or elsewhere.</comment></comment></comment></comment></comment></comment>


Show HN: Einstein's Special Relativity – Time Dilation - <AUTHOR> http://blabr.io/?f60c55e36d5ca3c4dd3e <comment><USER2> This is beautiful. It's the first time I've been able to understand special relativity in terms of geometry.

Your visualization makes it clear how everything from time dilation to length contraction can be derived from simply knowing the Pythagorean theorem and the constancy of c.

<comment><AUTHOR> Thanks very much. I really appreciate the feedback.</comment></comment>


Ask HN: Can you slow down with all that G+ - <AUTHOR>

Google is all over the News page,I understand that but slow down please. <comment><USER2> pg should add a way to coalesce news articles pertaining to the same event

<comment><AUTHOR> That would be interesting. It could be also easier to search for that links later if they were all in one group.</comment></comment>


Win3mu – Windows 3 Emulator - <AUTHOR> http://www.win3mu.com/ <comment><USER2> This is an awesome project. I highly recommend reading through his series on Medium (eg [https://medium.com/@CantabileApp/implementing-window- messagi...](https://medium.com/@CantabileApp/implementing-window-messaging-in- win3mu-979a0ea31571#.v6sylnl9p))

That being said, I think he is overestimating the market that would pay for this. This seems like it could attract at least a small community as an open source project, however. Unfortunately effort in development is not always rewarded with monetary gain.

Perhaps he should license it as GPL3 and offer commercial licenses? He may find some customers in software houses that are still selling Win16 software.

<comment><USER3> Also, Wine already exists. If Wine is ported to run on Windows, this project is redundant, I'd assume?

(In fact, it strikes me now that if you're on Windows 10, you could probably run Wine on the WSL.)

<comment><USER4> 16-bit applications can't run in long mode (i.e. a 64-bit OS), so you'll need a 32-bit OS to run these apps in WINE. WINE is just a shim and a library reimplementation, not an emulator, so it just passes the instructions on to the CPU, and you're limited by what the CPU can do.

Hmm... I wonder if you can run 16-bit applications in WINE on a 32-bit VirtualBox VM running on a 64-bit Linux system. That sounds like overkill, though. Might as well just use PCem or DOSbox, depending on your use case (PCem: cycle-accurate emulation of a whole PC, including specific hardware models and running any OS a real PC could; DOSbox: playing some old games for fun).

TBH, I'm not sure what win3mu's point is, either: it probably won't be open- source, and right now the only reason to _not_ use PCem or DOSbox is if you don't own a legitimate copy of Win3.1 and you're not willing to pirate it. An open-source clone of Windows 3.1 that can run any Win16 program in long mode (by interpreting the instructions like an actual emulator) would be a great idea, but this isn't it.

<comment><USER5> 64-bit Wine has been capable of running Win16 apps for years. It does require the Win16 app to be fully protected mode, but it works fine.

</comment></comment></comment></comment><comment><USER6> This seems ... insane. Good insane, learn-me-a-lot in-the-weeds insane but insane nonetheless

In the "why?" Section he mentions how a lot of programs don't run due to the quirks of the Windows API, and he is twiddling things to fix them.

Raymond Chen in "the old new thing" (#) documents his job at Microsoft which was to basically ensure windows handled crappy API calls that third party secs would make and any upgrades or alterations would break. They explicitly added code to windows like "if running adobe XXX then make our API call YYY perform differently and not return a Null"

This was a huge Microsoft department working over many years.

You flat out cannot emulate the Windows API. You just can't.

And all to run games that people today will find amusing for less time than it takes a Venti latte to get cold.

I wish him luck and happiness :-)

(#) [http://www.joelonsoftware.com/articles/APIWar.html](http://www.joelonsoftware.com/articles/APIWar.html)

<comment><USER7> >job at Microsoft which was

hot patching and shims is still a thing in W10

</comment></comment><comment><USER8> I was a Mac user and didn't play PC games until the Win32 era, but were there very many games for Win16? I thought that targeting DOS was still common well into the Win95 years.

<comment><USER9> Most games quit windows to gain the extra RAM, AFAIK. It wasn't until Windows 95, DirectX, and Windoom that Windows gaming caught on.

Or am I wrong?

<comment><USER10> Also, there was a transitionary predecessor to DirectX that some (primarily edutainment) games released for Windows 3.1 (and for a short while into early Windows 95) called WinG. So far as I know most of the WinG games also relied on Win32s to get access to 32-bit code, but I don't know if Win32s was a requirement to build a WinG game or if there were 16-bit games for that platform too.

</comment></comment></comment><comment><USER9> So, it's a closed source implementation of an API for an old OS/Windowing system atop DOS. Despite the fact that both DOSBox and Wine will run them fine.

And it's aimed at gaming, but most games quit windows and just ran on straight dos, so DOSBox is a better option anyways, especially considering that you're expecting me to pay for this, even though you've already said the compatability isn't great, and Wine and DOSBox are free and both have excellent compatability.

Sorry, not interested.

<comment><USER11> Or, a really interesting project plus a great series of blog posts.

From the FAQ on the author's site:

>Is it open source, can I contribute? >>Thanks, but no thanks. This project was started as a personal challenge/learning exercise. To have others contribute would defeat the purpose right now.

Which I don't quite agree with (why not just not accept pull requests?), but it's fair enough.

<comment><USER9> That would be fine, but he's charging for it. If you're charging for something, it has to be better than free offerings. But this isn't.

</comment></comment></comment><comment><USER12> Are there still apps for Windows 3 people would use on modern OS'? I'm under the impression you would run a VM if you really must, until/if when you make a transition.

<comment><USER13> I have one I'd love to use but it's no longer usable even under a VM. It's an audio mixing game called "No World Order" put out by Todd Rundgren back in 1993. It was a Windows 3.1 app, but remarkably worked up until I switched to Windows 7 64-bit. Even then, I could get it to work reasonably well with Windows XP in a VMware VM. Sound and graphics compatibility have never been a big priority for VMware, and the most recent VMware Workstation update seems to have broken the audio to a degree that I can't play the game anymore. I'm going to try VirtualBox at some point, but it's increasingly difficult to get a new Windows XP system up and running.

<comment><USER14> Try DOSBox.

</comment></comment></comment><comment><USER15> If you have connections in Embarcadero/Idera Software, now is the time to convince them to release Delphi 1 as freeware.

<comment><USER15> s/in /at /

While you wait for Delphi 1, note that you can already obtain Microsoft's 16-bit Visual C++ compiler and linker at no cost (the same does not apply to 16-bit Visual Basic) and that Open Watcom has been released under an OSI- approved, if weird, license. This tutorial goes into more details: [http://www.transmissionzero.co.uk/computing/win16-apps- in-c/](http://www.transmissionzero.co.uk/computing/win16-apps-in-c/).

</comment></comment><comment><USER16> I've been following the blog posts with great interest but I don't understand the move to turn it into a commercial project. I just don't think there's enough demand, especially for games (how many Win31-specific games were there?)

Where this would be incredibly useful would be for a lot of industrial automation, POS and other commercial software still stuck on Win31. Seems like it would make more sense to release an open source version and then add stuff like raw serial/parallel support as commercial add-ons to cover these cases.

Still, I don't blame Brad for wanting to get some return on his investment, he has put in a huge amount of work and it looks like a very well thought out and executed project.

<comment><USER17> I'd be fine if it stayed closed source and cost a few bucks to start, and then went open source after the initial revenue stream dried up.

Right now I run a WinXP virtual machine to play SimAnt and SimTower... I know nothing about VMs and was able to get everything installed and working in about 2 hours. So "messing with" virtual machines is not too much time, other than downloading and installing them.

Seeing as the Windows 3.1 crowd would be very niche, they'd most likely have no problem paying a small fee. I just hope it does go open source afterward.

</comment></comment><comment><USER18> This is awesome. What does the conversion process do to the executables? Is that part necessary?

<comment><USER2> I think the conversion process is literally just creation of a wrapper that launches the emulator.

</comment></comment><comment><USER19> I use Windows 3.1 a lot, mostly to play Solitaire. (Yeah, I could play a newer Solitaire implementation, but I like the nostalgia.) Also, my 3 year old son uses it for Paintbrush and Write - again, I get some nostalgia watching him using Windows 3.1 (although I myself didn't start using Windows until I was 9 or 10).

This is a cool idea, but running the real thing under VirtualBox appeals to me more. (Although it is slightly screwy - full-screen mode DOS boxes corrupt the display - due to using svgaptch to patch svga256.drv to support higher resolutions and colour.)

</comment><comment><USER20> It amuses me that the Win3mu logo appears to be using an italic version of the font Chicago, the original Mac system font...

</comment><comment><USER21> Will it use Wine (or Wine code)?

<comment><USER3> No, it's completely separate. Wine already supports Win16 apps IIRC.

<comment><USER22> Yes, Wine implements the Win16 API. I just tried tetris and ski and the both worked fine in wine-1.9.22 (Staging). Didn't even need to even create a 32-bit profile.

<comment><USER11> What distro are you on? I always find it difficult to use newer Wine versions on Debian.

<comment><USER22> I use a flavor of Ubuntu, but Debian also has an update system for wine. Just follow the instructions here:

[https://github.com/wine-compholio/wine- staging/wiki/Installa...](https://github.com/wine-compholio/wine- staging/wiki/Installation)

</comment></comment></comment></comment></comment><comment><USER23> Seems like a whole lot of hassle for little gain. A lightweight virtual machine should play those games perfectly, no? This guy is porting a huge amount of ancient APIs and their bugs too! Insane.

<comment><USER24> Plus he plans on selling it, not giving it away, and it's not open source.

<comment><USER25> What's wrong with that

<comment><USER26> There's an argument to be had about FOSS vs. proprietary software in general, but I think it's pretty clear when it comes to emulators. There is something wrong with closed-source emulators. Everyone who develops an emulator for a platform is working towards the common goal of preserving the software that runs on that platform so that people can continue to use it well into the future. All emulators build on research about the platform that has come before them, but if they don't release their source code, they don't advance the state of the art themselves. They're only useful for as long as they're actively developed and their closed-source binaries are compatible with modern operating systems, which means they haven't contributed to preservation of the platform.

Also, it's not like proprietary emulators are neutral towards the goal of preserving their platform, they can actually be detrimental to this goal. If Win3mu becomes more popular that QEMU/Wine, users will raise bug reports against Win3mu and certain issues will be fixed only in Win3mu. When the Win3mu dev loses interest or the platforms that Win3mu runs on become obsolete, those fixes will be lost. God forbid people will have to start running emulators on emulators when the best emulator for a certain platform stops being compatible with modern operating systems.

<comment><USER4> > God forbid people will have to start running emulators on emulators when the > best emulator for a certain platform stops being compatible with modern > operating systems.

Sadly, this is already happening. bZSNES is actually a thing now, since so many popular SNES romhacks will only run in ZSNES (i.e. not on real hardware, and not on a more accurate emulator like Snes9X or Higan), but ZSNES is written in 32-bit x86 assembly and contains a massive security hole that's been known for a while but hasn't been fixed.

It's even described as "a portable ZSNES emulator".

<comment><USER11> Jesus, you're not joking.

[https://github.com/mudlord/bzsnes- libretro](https://github.com/mudlord/bzsnes-libretro) is a port of some kind (NSFW commits possibly). Has byuu gone into hiding? His Twitter is protected and I can't find any safe source for the "original" bzsnes.

<comment><USER27> byuu posted an article on his blog (byuu.org) just two days ago. His emulator was called bsnes, not bzsnes, maybe that's the source of confusion? bsnes has now evolved into higan, so that might also be why you can't find it. The higan source is mirrored on gitlab: [https://gitlab.com/higan/higan](https://gitlab.com/higan/higan)

edit: sorry, wasn't aware of the (april fools) bzsnes release, realise now that I'm probably more confused than you are.

edit 2: the "original" bznes source (AFAICT) is on archive.org: [https://web.archive.org/web/20151105124237/http://snesemu.bl...](https://web.archive.org/web/20151105124237/http://snesemu.black- ship.net/emus/bsnes/bzsnes_v151s.zip)

</comment></comment></comment></comment></comment></comment></comment><comment><USER28> What is with that horrible music in his promo video?

<comment><USER29> hmm, I found the music so good I went and tracked down the artist and bought their album. [http://fm84.bandcamp.com/](http://fm84.bandcamp.com/)

<comment><USER30> Ditto</comment></comment></comment>


Microsoft's Augmented Reality 3D HoloDesk Lets You Play With Balls In Real Time - <AUTHOR> http://techcrunch.com/2011/10/21/microsofts-augmented-reality-3d-holodesk-lets-you-play-with-balls-in-real-time/

<comment><USER2> Something similar from a few years ago: <http://www.youtube.com/watch?v=Y-P1zZAcPuw>

Unless I missed it, the microsoft HoloDesk does not provide tactile feedback like the one in the outube video. Still cool though.

<comment><USER3> How would one do that?

Lasers? Focused blasts of air?

<comment><USER2> Its explained in one of the video (at 1:00). Basically they use a focused ultrasonic beam to create tactile feedback.

</comment></comment></comment><comment><USER4> Who writes these titles?

<comment><USER5> Same thought. Wonder if those titles are generated simply for a more descriptive url. In that case, I think writers are missing their target audience - humans.

Also this particular title strikingly resembles typical MS's writing signature such as "Buy a home, get a US visa, Senators propose"

See [http://bottomline.msnbc.msn.com/_news/2011/10/20/8413642-buy...](http://bottomline.msnbc.msn.com/_news/2011/10/20/8413642-buy- a-home-get-a-us-visa-senators-propose)

You would certainly get a low mark at an elementary writting class for a paper title like that.

</comment></comment><comment><USER6> It's funny to think of how primitive this will seem in a decade's time -- like the first TVs or the first cell phones.

</comment><comment><USER7> Love the title. Though it made me think the video would be something different.

"Ghost in the Shell"-style tech is the way of the future.

Anyone else excited about the yet unreleased Sony HMD?

</comment><comment><USER8> Kind of makes you wonder why "Microsoft Research" isn't just "Microsoft".

<comment><USER9> Because "Microsoft Research" doesn't have to consider silly things like profit (or even marketability), that's for big MS to figure out.

<comment><USER10> You become the first company to launch a phone that can be interacted with in 3D, you become very, very profitable.

<comment><USER11> Not if your phone costs thousands of dollars to manufacture and you haven't yet worked out how to make the 3D interaction actually useful for anything.

</comment></comment></comment></comment><comment><USER12> ..and here I thought I could already do that.

</comment><comment><USER13> At last.</comment>


Where, how and why would China get the source code to Microsoft's Windows? - <AUTHOR> http://www.guardian.co.uk/technology/2010/dec/04/microsoft-source-code-theft

<comment><USER2> It wasn't just Windows -- at the time I also heard that Exchange and Office were also affected.

There was also concern that the hackers might have inserted back doors into various software. I know one group that decided know verify each checkin over the four month period.</comment>


Daruino embedded platform wish list - Viva La Evolution - <AUTHOR>

Hi Hacker News!! The Daruino team here, working on making the world a smarter, more connected place....
In preparing to launch our Minumum Viable Product, we'd really like to know, which of these would you be most likely to use or to fund on kickstarter?
All of these are projects which I have found to be personally useful and I would definitely purchase and use if they were available on the market as described, but I am a "special use case" so I thought I would throw this out to the HN community and see what comes back!
Please answer either (I,II,III,or III+IV), and include any additional info that you want to! I Have all of these projects prototyped , but trying to decide what the market needs more...Thanks for checking this out!
I) A tiny, lightweight 14 pin DIP Package that costs <$8 with the following specs: ARM Cortex M0 processor, 50MHZ 32KB Flash, 8KB SRAM 4 channel 10 bit ADC 10 GPIO lines 16&32 Bit timers 1 Uart, SPI Pins optional for stand-alone integration Programmable in C/++ using readily available open source tools over serial port
II) A tiny, lightweight Dip28 Package that costs <$15 with the following specs: ARM Cortex M0 processor, 50MHZ 128KB Flash, 16KB SRAM Pin compatible with ATmega328p / Arduino Uno, plugs into arduino board if desired Drop in to "Arduino" circuits to give a big boost in capability 16&32 Bit timers 2x Uart, SPI, 2xI2C Pins optional for stand alone integration Programmable in C/++ using readily available open source tools over serial port, could probably be readily made compatble with the Arduino DUE IDE
III) A 4cmx6cm systemboard that costs <$25 with the following specs: ARM Cortex M3 processor, 100(120)MHZ 512KB Flash, 64KB SRAM 8 channel 12 bit ADC 10 bit DAC 70 GPIO lines 16&32 Bit timers 4xUart, SPI, 3xI2C, I2S, CAN (tranciever not on board) USB Host support (HOST connector not on board) Ethernet MAC (PHY not onboard) Pins optional for stand alone integration
III+IV) This unit would also optionally include a daughterboard (<$25) that provides Ethernet PHY w/ RJ45, USB Host connector, uSD slot, CAN transceiver, possibly other functions.
Programmable in C/++ using readily available open source tools over usb port Out of the box Programmable in structured scripting language (BASIC-Like) with built in IDE via web browser, telnet, serial(USB), or composite video (or vga) / keyboard (stand alone retro computer action set capability!).
Note that III / III+IV are in the price range of the Raspberry Pi, which is -much- more capable computer, but as an application processor, not a microcontroller, it is not optimised for low power battery operation (months of operation from a few AAA's or lithium pack) and is not equipped with a similar range of analog peripherals, nor a similar quantity of GPIO.
Viva La Evolution! <comment><USER2> What is "Daruino"?

I do a lot of microcontroller hobby projects using Arduino boards, ATMega chips, and STMicro ARM chips, so I'm a likely customer for your project.

I don't think I'd have a use for #1. I am not often performance-limited on the ATMega328, except for applications involving lots of high-resolution PWM, which wouldn't fit on such a device due to its limited array of IO pins.

#2 is interesting, though I wonder how long the Dip28 format will remain relevant. The LeafLabs people have tried doing the straight-line upgrade path from Arduino by designing a board with the same form factor, but your idea is even more elegant. I might use a handful of these for prototyping.

#3 sounds a lot like the Maple board. The crucial thing here is the growth path from protoboards up to custom circuits. The STM32Discovery board is cheap and capable, but its toolchain story is totally fucked (windows only proprietary uploader, undocumented protocol!), so it ends up being useless for prototyping. The Maple board is good, but it is hampered by the use of the Arduino IDE. It's really easy to outgrow the editor's constraints when you are developing for a Cortex-M3 chip, but it's not easy at all to break your project out into a gcc/makefile/upload type world. At least, I've had no luck making it work.

#3+#4 sounds like you're reinventing Arduino shields, no? Again, maple did basically the same thing and it seems to work out ok.

I don't think you need to worry about collision with Raspberry Pi, despite the price-point overlap. Not in the near term, at least, simply because of power consumption and complexity. It's a miniature computer, not a beefy microcontroller; I generally don't _want_ an operating system getting in my way when I'm building embedded stuff.

Arduino took over because it offered a totally unbeatable development experience and didn't try to box you in. It's about as simple a process as one could possibly expect: you write code, pick a target board, push "upload", and it runs. It's all open standards under the hood, and they document everything you need to know about the board design, so there's no vendor lock-in anywhere. Mimic this strategy and you will go far. In fact I would say that your toolchain is _more_ important than the capabilities of your board! Anyone who is capable of pushing through a dodgy toolchain to get their prototypes working is probably capable of building their own devboards, or of adapting some existing devboard to their needs. The real market opportunity comes from offering a seamless experience to beginners which still allows them a smooth upgrade path out of your environment. Beginners don't stay beginners forever, but the Arduino experience shows that ex-beginners will stick with your brand and buy your products as a convenience even once they've moved on and learned how to design their own, but only if you make it easy for them to outgrow you.

<comment><AUTHOR> thank you for your well considered reply....good info, and we're listening!!!

<comment><USER2> just found the "Daruino" pages - Google had been not-so-helpfully redirecting me to a search for "Arduino", assuming "Daruino" was a typo. Perhaps a more unique name would improve your searchability?

Your 28-DIP plug-in board seems like a great place to start. It's a useful gizmo in its own right, as an ARM-breadboarding tool, but the "just swap this in to make your Arduino run faster" angle is a great gimmick. I would definitely buy this, if only to play with it.

What scale of manufacturing do you have in mind? If I decide to order fifty and want them in two weeks, is that likely to be possible?</comment></comment></comment>


Taskwarrior for Linux - <AUTHOR> http://taskwarrior.org/projects/show/taskwarrior <comment><USER2> I am surprised no one has commented on this one. Task Warrior looks pretty impressive for a command line task management app. The one thing I need that Task Warrior, org-mode, Trello, and all of the rest, do not have is a way to schedule/plan my work... I over-commit BIG time, I need help understanding what I've committed to do and controlling that work. I've had great success w/ Scrum and tools like HP Agile Manager and Rally in a professional setting, but I need something w/ the same effectiveness for my personal work.</comment>


Our Pirate Game is Getting Owned By App Store Pirates - <AUTHOR> http://silverskullgame.blogspot.com/2009/09/our-pirate-game-is-getting-owned-by-app.html

<comment><USER3> A nice sensible response, with some well-reasoned observations.

The thing about piracy I've always found weird is how hysterical some people get about it for their medium and not others. For example, I am good friends with several software developers who get furious about people pirating their products, but have no qualms about having gigs of copied music personally.

<comment><USER4> I think the rationale people are using here is that it's the record companies they're pirating from not the artists.

Artists like Janis Ian ( <http://www.janisian.com/article- internet_debacle.html> (be sure to read the follow up)) have made that point quite eloquently.

Still, the basic position is one of hypocrisy, no contest there.

<comment><USER5> And EA and the other big game companies aren't just like them?

The people that I know that pirate the most music do so off independents more than mainstream.

<comment><USER4> > The people that I know that pirate the most music do so off independents > more than mainstream.

That's really bad.

</comment></comment></comment></comment><comment><USER6> 85% piracy rates. Ouch. It hurts me to even read that, although part of me has to point out that when you're developing for an audience which considers $2 expensive and $5 highway robbery, going in with the expectation that people will happily pay you money is a little optimistic.

On the plus side, you can't possibly have a worse piracy problem with your application than China does with everything, and you'll probably eventually do what Chinese software companies do: put the real meat on the server, let everyone have your client for free, and let the users who prefer to Own Their Games Instead Of Renting Them cry to themselves in the corner.

<comment><USER7> I've read a few articles/posts about piracy rates, and it seems that a piracy rate of 90% is "normal", at least for PC titles. So to me it seems like piracy on the iPhone is lower than it could have been, and a lot lower if it drops to 50%. Still a problem, of course, but if Apple keep making it more complicated to jailbreak the hardware it might actually be moving towards 0%.

</comment></comment><comment><USER8> Eh, this game is being pirated more than the average app.

From what I heard at Greg Yardley (PinchMedia)'s talk at 360idev yesterday, the average piracy rate is 34%. My personal experience with Boxcar lines up with those numbers, along with a 0.056% conversion rate from pirated to paid. The "average" there, again according to PinchMedia, is 0.043% or 1 in 233.

They're taking the right approach in that, well, the truth is if someone is going to pirate something then even if you try and dissuade them they'll just move on to the next one. In my particular case, I send a push notification letting them know we've detected that they are using a pirated copy, and then disable their account. If they purchase the legitimate version, their account will automatically be re-enabled.

If I didn't have a backend server with monthly hosting costs, I wouldn't care that the application was being pirated. They use it, then move on. Based on the conversion rates I've seen myself and have heard of from others, it's just not worth the effort to try and get someone to purchase it.

Those conversion rates also invalidate the entire "I'm just trying it before buying it" argument, which is complete bullshit.

Pirates discuss it on Twitter: <http://twitpic.com/jor06>

And I also get emails about it -- angry ones: <http://jdg.net/post/160979167/retard>

[http://jdg.net/post/151845213/some-people-just-amaze-me- unfo...](http://jdg.net/post/151845213/some-people-just-amaze-me- unfortunately-this-is)

[http://jdg.net/post/142912680/yep-dont-buy-this-piece-of- cra...](http://jdg.net/post/142912680/yep-dont-buy-this-piece-of-crap-or-how- about)

<comment><AUTHOR> Interesting data...to your point about our piracy rates being high at 85% - <USER2> agree but think it is only a symptom of our App being new and expect it to trend toward 50% or less in a few months.

Also important to note is that calculated the piracy rate as the difference between iTunes sales and Pinch media uniques. I have found that Pinch Media's data is less conclusive than it used to be so I wasn't using their metrics for either cracked or jailbroken phones.

As for the pirates try before they buy excuse, I agree that this is probably not the case. I think it is a churn game (similar to music) for most pirates - they try hundreds of apps for very little time and stick with only the very few that they like.

As for your piracy block - I tried this once and decided better to let them have a lite version of the app over blocking them entirely. Not sure the point of angering the most vocal, early adopters on the web. Check out a post I wrote dealing with this: [http://www.icombatgame.com/2009/05/22/on-the-web- every-users...](http://www.icombatgame.com/2009/05/22/on-the-web-every-users- opinion-counts-even-the-pirates/)

</comment></comment><comment><USER9> It's interesting that they claim that piracy was largely responsible for an increase in sales... I wonder if this is more because people are using piracy to sample the games before they buy or because the pirating users are increasing the buzz behind the game?

<comment><USER10> According to him, the pirate users only sampled a little bit of the game before moving on. As the OP states, pirates are more interested in the novelty of it.

<comment><USER11> That's an interesting point - pirates mostly don't actually use their stuff!

Essentially pirating is a way to try the app out, then I guess the percentage of pirates who buy it is pretty high. So why not make trying apps more convenient?

</comment></comment></comment><comment><USER12> _Why we are not that concerned that our app has been pirated:_

I think it takes a small dev studio or independent developer to have enough feel for these reasons why piracy isn't so bad.

I feel the same way about my book - I like seeing people pirate it, even if the publisher doesn't! It doesn't seem to hurt sales and raises awareness, as these guys have found.

That said, ripping off a PDF to boost print book sales is a different kettle of fish than ripping off a game that's identical to the legit version.. I wonder how this will fare long term.

<comment><USER13> Off topic: What are the final costs of a book and what is the share? (i.e. printing, authors cut, publisher's cut)?

Buying books really hurts my back-pocket (the last book cost me $140+ dollars – and it is a lot more expensive if you do the currency conversation). What is sad is that when I move to another country I will not be able to move all my books. If there is a good e-book reader and books are well-priced (e.g. $30-40 directly to the author) it would feel a lot less painful.

<comment><USER12> I don't know the costs because I'm not a publisher but.. I think my book has an RRP of $40. Most places sell it for less than that. Amazon, for example, sell it for $26.

According to my royalty documents, my publisher gets about $18 per copy and I get between 10% and 20% of that depending on how many copies I sell. The 20% rate only kicks in after about 25,000 copies or so and few programming books do that well (my first edition sold just under 10,000), so effectively I get around $1.80-$2.50 a copy.

</comment></comment></comment><comment><USER14> You have to compete with piracy by offering premium levels of service one where it requires your users to pay to connect to your server to say play against others across the world and other things that require a server connection.

Sure they might try to break into your server, but less will do that and that is more illegal and punishable by law at least in the states.

Piracy made hollywood and music biz innovate we should be no different.

</comment><comment><USER15> How are people cracking and using cracked applications on the iPhone? Am I just living in the dark by using the App Store and clicking "Install"?

<comment><USER16> I don't get it either. My guess is that people install a cracked version through Cydia to use on a jailbroken iPhone. I'd love to have this confirmed though.

<comment><USER17> You can't install cracked stuff through Cydia, you have to use something like installous via hackulo.us.

</comment></comment></comment><comment><USER18> "Piracy rate" doesn't seem like a useful metric; it's too dependent on your sales. I'd rather see sales numbers and piracy numbers.

If you sell 10 and have 10 pirates, that's a 50% piracy rate. If you sell 1000 and have 10 pirates (same number of pirates) that's only 1% piracy rate. The ratio is less useful and more misleading than the raw numbers.

<comment><USER19> Agreed - especially given the stated belief that the pirates are in it for novelty, many will presumably delete the game after cycling through it. As such, piracy rates go down over time (a trend noted by the OP), even if sales figures (which are more important) don't change much at all.

Of course, doesn't take away from how great it is for them to share this information at all.

</comment></comment><comment><USER20> Since the cost of the app is so low, along with the barrier of entry to buy it, this data suggests to me these people must be discovering it through the piracy community (peer recommendation basically) If they've already learned how to pirate iPhone apps it's probably just easier for them to use a process they're familiar with. I'm guessing the ability to do batch installs of many apps at once is a big selling point of the iPhone piracy community so maybe Apple can learn something from that.

</comment><comment><USER21> The sad thing is that it is incredibly easy to catch pirates if only Apple allowed us to.

<comment><USER22> The pirates would then take the necessary steps to avoid being caught.</comment></comment>


The Peculiar Math That Could Underlie the Laws of Nature - <AUTHOR> https://www.wired.com/story/the-peculiar-math-that-could-underlie-the-laws-of-nature/ <comment><USER2> > _quaternions underlying Albert Einstein's special theory of relativity_

I never heard that. Wikipedia has a paragraph about it, but I'm not convinced. Do anyone has a good link about the use of quaternions in SR?

</comment><comment><USER3> [https://news.ycombinator.com/item?id=17575585](https://news.ycombinator.com/item?id=17575585)

</comment><comment><USER4> 8 dimensional symmetry as the fundamental underpinning of the universe is quite beautiful. I hope this is the beginning of a real G.U.T.</comment>


Ask HN: How do I build a chatbot for websites? - <AUTHOR> I have seen dozens of chatbots/NLP's SaaS which are great for integrating them into existing social channels such as Facebook Messenger, Twitter, Slack, etc. However, is there a simple solution to implement NLP such as Dialogflow or LUIS, IBM Watson for websites, which works "out of the box" in terms of cross-platform availability (Desktop: Windows IE, MacOS, Mobile: iOS, Android, and App SDK) and that is flexible in terms of UI? <comment><USER2> I think you would have some front end that is a web application that presents an interface that looks a lot like instant messenger.

The front end could be very thin and made to work on a web browser on computers, phones, tablet, etc. You could implement the front end on any of those app platforms if you want also.

The back end sends commands like "display this image", "display these words in a bubble", "wink", "display these choices" and gets notifications from the client about what the user does.

All the brains then are on the back end, on the controlled environment of the server where you can deal with database connections, NLP, all that.

Ping me to chat more.

</comment><comment><USER3> There are companies that have commercial chatbots. Some of them have participated in Turing or Loebner competitions. But a useful bot should be restricted to work into a small domain.

An probably from the point of view of the company that uses one, there should be enough reporting and simple ways to steer its behavior.</comment>


Ask HN: What makes good documentation? - <AUTHOR> I'm about to release my first OSS project in a long while. I've been putting a lot of effort into the docs. Its super important for me that the docs are useful and clear.
In your opinion, what makes good documentation?
What does documentation need to have in order to be useful to you?
This is the documentation I'm looking to improve:
https://yelluw.github.io/Bootparts/documentation
Thanks for your feedback! <comment><USER2> Thank you for releasing a project into the wild! :)

Without getting into a long-winded rant about good docs, here are some things that you could do on your page:

 _Make it clear what your library adds over Bootstrap._ There are a lot of similar sorts of things out there, and it isn't immediately obvious what yours brings to the table. Give an executive summary with concrete details of functionality in your introduction, i.e., "This adds better footers, calls-to- action, and useful templates for prototyping not found in vanilla Bootstrap".

 _Consider embedding the code snippets instead of linking to Github._ If you want, embed the snippets as gists or similar, but linking out to Github is a little weird for what should be short example code.

 _Consider moving the component explanations above the FAQ stuff._ It's hard to imagine that people will want to know if they can contribute code or money without having seen the actual product in use.

Best of luck!

<comment><AUTHOR> Wow, thanks for this feedback. It is exactly what I was looking to hear.</comment></comment>


Show HN: go back in time and get nostalgic about 2010 with rrrewind.com - <AUTHOR> http://rrrewind.com <comment><USER2> I realize this is probably a pet project for the fun of it, but at least you may want to monetize the Amazon section.

<comment><AUTHOR> Thanks. Actually the original idea was made something with affiliate links and Top games, top books, top songs... But it changed into more a media consumption app. Your idea is still good, but I'm more focused on make something useful and look to monetize it later.

</comment></comment><comment><USER3> This is really cool! I would like to be able to have an easier way to view a specific date. A calendar button would be nice.

Also the ability to see the most popular results for a date range?

<comment><AUTHOR> thanks for your input. a calendar is in my to-dos. At this moment you can use the archives link top-right

</comment></comment><comment><USER4> Looks like top stories on HN grow to be top stories elsewhere.

<comment><AUTHOR> Yes. I notice that too. I would like to do some visualizations of trends in time.

</comment></comment><comment><USER5> Not sure about the logo, and the colors behind the logo. Liked the Dribble addition. Maybe the photos and designs make the site shine.

<comment><AUTHOR> got a suggestion? the idea is left=past=hot right=now=cool hot stuff that becomes cool

</comment></comment><comment><USER6> I would like to see something similar, but that tells me what major events which happened on this day the past years.

<comment><USER7> "This day in history", appearing in print, then radio, then on birthday cards, then television, then the internet. If you look, you'll find what you seek pretty much everywhere.

</comment></comment><comment><USER8> Very cool idea. You could even go the breadpig route and sell "On this date..." birthday cards for geeks!

<comment><AUTHOR> Thanks. Checking that. Does it really work?

</comment></comment><comment><USER9> HN only goes back to 10/28?

<comment><AUTHOR> Yes. I added it a bit late. Same for Dribbble.</comment></comment>


Launching a start-up and having a family life: It's possible  - <AUTHOR> http://entrepreneur.venturebeat.com/2009/09/07/launching-a-start-up-and-having-a-family-life-it%e2%80%99s-possible/ <comment><USER2> To be perfectly honest, you got to ask my ex-wife about this.. I learned this the hard way unfortunately. Before starting a venture, make sure the foundation of your couple and family are strong. It takes a LOT of commitment, patience, energy just to get yourself started. Imagine that you have to invest as much on the personal level too (if not more). If you don't, your partner/wife will resent you. I know it's hard, but always try to balance things out. Time management is a key.

Edit: I am now where I wanted to be professionally, it took me more than a year of hard work, sleepless night juggling between a fulltime job, my ventures, and divorce documents.. I am 'successful', but no one to share it with :(

<comment><USER3> The trouble is in knowing the strength of the foundation. Too often we don't want to admit the failure and keep bad things going because of all the wrong reasons -- kids, mortgages, income etc.

<comment><USER2> Agree. Look even if you share the same vision of long term growth when you just get married, the reality of the short term responsibilities mobilize all your time and focus. So I learned that there is no such things as tacite mutual agreement in marriage. You've got to remind your partner your long term common objective almost constantly. I thought it's a given, it's not. To take a programming analogy, setting the variables at the beginning of your code is not enough, you've got to use 'global $variablename' within functions (like function workinglate($longtermvision, $values, $love)) to make sure your variables are set and passed on to each function/decision.

Btw, the programming analogy seems to apply that on all types of relationships: couple, work, business partnerships. For some mysterious reasons, short terms challenges (bills, rent, mortgage, loans, etc.) keep blinding our long term objectives.

</comment></comment></comment><comment><USER4> Excellent article. Here's what'll stay with me:

"The irony is when I was working insane hours it was to make someone else wealthy. When I moderated my behavior it was when they were my startups."

and..

"This life isn't practice for the next one."

I'm probably much younger than most entrepreneurs here (I'm 22), but I could relate to everything Steve had to say. And I'll add to it; it doesn't pay to be burnt out with unhappy people all around you. The negative energy undoubtedly has an impact on oneself. But what takes the cake, is the realization about how you'd like your gravestone to read.

</comment><comment><USER5> The biggest factor that Blank had in his favor was that he worked outside his home. If you are going the "garage route" like a lot of YC companies, then I think it is much harder - maybe impossible - especially when your children are young. An environment with your kids in it isn't particularly conducive to working, and young kids will want you to be engaged all the time. There's not a noprocrast setting on a two-year-old.

<comment><USER6> Which is why you should never go this route. Work in the local library and a coffee shop (for scheduled calls). It's better than your home office and it keeps your hours clear.

</comment></comment><comment><USER7> Having kids is a huge motivator to succeed.

I started my business when I had one son. I was young and had no fear. Now I have 4, a mortgage, etc, so basically failure is not an option without major consequences. It keeps me hungry for success and doesn't slow me down in the slightest.

</comment><comment><USER8> Sometimes an article comes up somewhere that fits life perfectly for that moment. I'm currently on vacation, taking some time to figure out how I can achieve a normal life (family, real social life, etc) while running a startup.

A lot of his checklist I figured out (but rarely followed) when I was working a normal job and trying to balance my fiancee and my startup, and some I figured out when looking back, but things like the family dinner and engaging your spouse just didn't really occur to me there. Hopefully I can take his information and make things work out better in the future.

</comment><comment><USER9> Seen this before, but I like the article. I have been involved in three--one well before I had kids, one now that the kids are out of the house, and the other, well, that was not all that good--was not following his examples.

</comment><comment><USER10> Er this is just a verbatim repost of [http://steveblank.com/2009/06/18/epitaph-for-an- entrepreneur...](http://steveblank.com/2009/06/18/epitaph-for-an- entrepreneur/). See <http://news.ycombinator.com/item?id=663432>

</comment><comment><USER11> "back at work for another 4 or 5 hours until the wee hours of the morning."

What if you need sleep?

<comment><USER10> Don't start a startup.

</comment></comment><comment><USER12> Work, life, sleep: choose two.

This is different from college how?

<comment><USER13> "Life" before you have children is very different than "life" afterward.

<comment><USER14> Same with "sleep" (which in turn will directly affect our kind of work).

</comment></comment></comment><comment><USER15> I think one of the most difficult things about this to manage politically is actually the reconciliation of <http://www.paulgraham.com/procrastination.html> with the comparatively pedantic, very detail-oriented and exacting household maintenance methodologies of most women, and the expectations they have for you to participate.

</comment><comment><USER16> Surround yourself with supportive people that understand your sacrifice and your hard work. Whom understand the long hours, and the large feat that you are trying to accomplish, and you can be successful. Have a supportive wife/husband, parents, friends etc, and you will be ok. If they are not supportive, then maybe they are not the ones for you. Cannot do both without that support.

</comment><comment><USER17> Revised title: "Launching a start-up and having a family life: It's possible if you're a man and can dump all the child-rearing on your wife."

<comment><USER18> Point of order: a female entrepreneur could just as easily put the child- rearing on her husband.* And there's no need for the negative connotation: is it impossible that one partner can happily take the lion's share of the child- rearing duties so that the other can focus on a business?

* applies for all two-gender permutations

</comment></comment><comment><USER19> A recent quote from a local VC: I've never known an entrepreneur to bootstrap a business to a big win who's marriage survived doing so.

Which is what made me leave Atlanta for Silicon Valley.

<comment><USER6> And I know multiple entrepreneurs who did exactly that who have amazing families. You want probably the worst person in the world to take life planning advice from? "A local VC".

<comment><USER19> Hahaha, I don't know anyone who bootstrapped a startup to serious cash since 2002 in Atlanta, PERIOD - and I've looked really hard, talked to everyone in town - let alone that did it and kept a family.

</comment></comment></comment><comment><USER20> how about an article on working full time, coding in any spare time you have, attend networking meetings and try to maintain a basic relationship with a gf.

</comment><comment><USER21> Sure, it's possible -- lots of things are possible.

However, I'd argue that it's pretty improbable (at least in the early stages).

</comment><comment><USER22> WhatEVER. Working until 7, then several more hours after the kids go to bed, and half a day on Saturday, doesn't fit any definition of "balance" that interests me. Also, you've carved out a couple of hours a day for your kids, but what about your wife? Those hours after the kids go to bed are our best quality time alone.

</comment><comment><USER23> Curiously absent from his list is time spent on social networks (including HN).

</comment><comment><USER20> how about an article on working full time, coding any spare chance you have, attend networking meetings and try to maintain a basic relationship with a gf.</comment>


Model S owners are already reporting that Tesla's Autopilot is self-improving - <AUTHOR> http://electrek.co/2015/10/30/the-autopilot-is-learning-fast-model-s-owners-are-already-reporting-that-teslas-autopilot-is-self-improving/ <comment><USER2> Is this a case them being told it's improving so they perceive it to be doing so?

<comment><USER3> Nope.

One user in the article gives a stat in the form of "number of times auto- pilot needed assistance". And that stat was decreasing. That seems to be a pretty impartial statistic.

<comment><USER4> Very exciting. I'd be curious what information the Model S is sending back when those corrections take place, for other Model S vehicles to "acquire" that knowledge.</comment></comment></comment>


Allergic reactions play role in sexual behavior development - <AUTHOR> https://neurosciencenews.com/allergic-reaction-sexual-development-10947/ <comment><USER2> This is an interesting article, but it's worth noting that the study was on rats rather than humans.</comment>


Norway announces total ban on fur farming - <AUTHOR> https://www.livekindly.co/norway-announces-total-ban-on-fur-farming/ <comment><USER2> Fools placing animals rights over human property rights will be coming after meat next.

<comment><USER3> You mean the property rights humans appropriated from the natives, be they native humans or animals? Might makes right and all that BS?

I respect animals since they are generally honest about their intentions. Humans not so much.

</comment></comment><comment> saiya-jin Can't reach the page ('core files updade'?), so commenting just on title:

Not that I don't approve general approach and direction, but what about other animals being 'farmed' for fur/leather and other 'components', ie cows? Yes, we use much more of dead animal compared to just fur, but that seems just semantics and has nothing to do with minimizing suffering or any other moral aspect I can think of.

If I got it all wrong please correct me, couldn't access the cached version due to proxy restrictions at work.

<comment><AUTHOR> From the article since you were unable to access.

The ban, they say, will be finalized in 2025, when all farms in the country will be shut down. It's unclear, at the moment, how this will affect the sale of fur (whether Norway intends simply to stop producing it).

Norway is a large fur producer with over 300 fur farms, with farms breeding and killing over 700,000 minks and 110,000 foxes every year — simply for their fur. They're far from the largest manufacturer (that'd be China) but they aren't the smallest either.</comment></comment>


Covid Protocols - <AUTHOR> https://www.covidprotocols.org/ <comment><USER2> Nice find. I find this interesting too:"Internet Book of Critical Care (IBCC): COVID-19" (Written by a pulmonologist): [https://emcrit.org/ibcc/covid19/](https://emcrit.org/ibcc/covid19/)</comment>


Ask HN: Why is it still so hard to host your own email/calendar that just works? - <AUTHOR> It seems to me that email and calendar data are so personal that you shouldn't have to trust someone else to store and handle it for you. Yet when I try to find a way to host it for myself I get scared of the trickiness of the setup or the amount of maintenance required. Am I just looking for all the wrong things or is it in this day and age not possible, even for a reasonably tech savvy person, to host your own email and calendar securely? With securely I mean secure from all adversaries except for maybe nation-state adversaries. [edit] Like many people have pointed out in the comments an even bigger problem is being blacklisted by other ISPs. Any ideas how to deal with this while still maintaining control of where your emails are stored? <comment><USER2> This post [1,2] from last October discusses a major problem with hosting your own email, which is that the big email providers pretty much reject your messages until your "reputation" is good. The reputation concept is purportedly a spam fighting effort, but a more cynical view is to see it as an effort by the big providers to sabotage self-hosted email. More discussion here [3] and here [4].

[1] Original post, now defunct: [http://liminality.xyz/the-hostile-email- landscape/](http://liminality.xyz/the-hostile-email-landscape/)

[2] Thank you archive.org: [https://web.archive.org/web/20151121132739/http://liminality...](https://web.archive.org/web/20151121132739/http://liminality.xyz/the- hostile-email-landscape/)?

[3] [https://news.ycombinator.com/item?id=10405681](https://news.ycombinator.com/item?id=10405681)

[4] [https://lobste.rs/s/ckfyqd/the_hostile_email_landscape](https://lobste.rs/s/ckfyqd/the_hostile_email_landscape)

<comment><AUTHOR> Well this seems to be a dealbreaker, I can't have an email server that is likely to get blacklisted.

<comment><USER3> I happened to post comments in GP's cited thread and also another email server thread. You can read both of them to get a deeper understanding that personal email servers are hampered by "trust" issues more so than technical challenges.

[https://news.ycombinator.com/item?id=10405945](https://news.ycombinator.com/item?id=10405945)

[https://news.ycombinator.com/item?id=10498988](https://news.ycombinator.com/item?id=10498988)

Basically, you could conceivably get past all the technical set up. There may even be Docker containers or virtual images to jumpstart most of the set up. Or you can follow some step-by-step instructions.[1]

However, the problem is that SMTP servers originating from residential IP addresses _by default_ are treated as home computers that have been hijacked by a malware spam bot. Using Bayesian reasoning, this is a rational filter because the number of zombie home computers sending unwanted spam vastly outnumbers any tiny amount of "good" people setting up legitimate SMTP servers.

Given today's realities of distrust-by-default (unknown SMTP server is guilty until proven innocent), it looks like the best strategy for a "personal" SMTP server is to pay for a virtual machine at a hosting provider (Rackspace, etc) whose IP address ranges are not blacklisted. You could then run encrypted email storage there so Rackspace has no visibility into private emails.

[1][http://arstechnica.com/information-technology/2014/02/how- to...](http://arstechnica.com/information-technology/2014/02/how-to-run-your- own-e-mail-server-with-your-own-domain-part-1/)

</comment></comment></comment><comment><USER4> I run my mail server using docker, specifically the following images:

      * mailserver: https://github.com/tomav/docker-mailserver
      * webmail: https://github.com/jprjr/docker-rainloop

Combined in docker-compose:

      version: '2'

      services:
        mail:
          image: tvial/docker-mailserver:latest
          hostname: your_hostname
          domainname: your_domain
          environment:
            SSL_TYPE: letsencrypt
          ports:
          - "25:25"
          - "587:587"
          - "993:993"
          volumes:
          - ./data/mail:/var/mail
          - ./data/config/:/tmp/docker-mailserver/
          - /etc/letsencrypt/:/etc/letsencrypt
        rainloop:
          image: jprjr/rainloop
          environment:
            NGINX: 1
          ports:
            - 80:80
          volumes:
            - "./data/rainloop:/var/lib/rainloop/data"

The docker-compose.yml and postfix-accounts.cf files are the only configs you need for a basic setup.

See the projects on github, especially docker-mailserver for further info on complete features of this setup.

<comment><USER5> That seems pretty cool. How long have you been doing this? For your primary email? How has it been working for you?

<comment><USER4> I've had this setup for about a month on my primary email, and it is working flawlessly. Even when I had to reboot the server, I was able to bring everything back online quickly.

I am keeping a lower priority MX dns entry pointed to an independent provider as a failover, but this is standard practice, I believe.

What I really like about the docker-mailserver image is that it has no database and that it is designed for simple updates (that is, docker pull && docker-compose restart).

Rainloop is also new to me (I previously used roundcube) and again I am very positively surprised: it works over imaps, so multiple accounts can be combined under a single login, it supports 2FA, manages both plaintext and html, manages your contacts, it supports openPGP (still in beta, I've not tried it yet).

</comment></comment></comment><comment><USER6> It is especially difficult to stop others from just blackholing your email.

This serverfault question helps to illustrate the problem

[http://serverfault.com/questions/434703/why-does-hotmail- sti...](http://serverfault.com/questions/434703/why-does-hotmail-still-reject- my-emails)

The problem? Not enough traffic causing a low sender score. Hotmail isn't the only one; large and small ISPs across the world do it.

<comment><USER7> Hotmail is the worst though. I hate the engineers at Microsoft who designed their email filter.

</comment></comment><comment><USER8> I can recommend iredmail. It's been around for a long time and supports several major OS. There is also paid support should you need it.

[http://iredmail.com/](http://iredmail.com/)

<comment><USER9> thank you so much for mentioning. didn't know this.

anybody has xp with one of these?

[http://mailinabox.email](http://mailinabox.email)

[https://poste.io](https://poste.io)

edit: "awesome list" of things: [https://github.com/Kickball/awesome- selfhosted#complete-solu...](https://github.com/Kickball/awesome- selfhosted#complete-solutions)

<comment><USER10> Wow qmail! Instant confidence.

</comment></comment></comment><comment><USER11> Go download Zimbra (I'm not affliated with Zimbra, just have used it in the past), it's easy to setup and full featured.

The real trouble is keeping your domain off blacklists and managing security updates.

<comment><USER7> The real trouble is getting your emails delivered. The big companies have basically outsourced the spam filtering problem to the email service companies - an email from outside the club has a x% chance of being randomly marked as spam (x is some number between 1 and 5%).

After 15 years of hosting my own email server without issue I had to make the business decision a bit over a year ago that I can't afford to have 5% of my emails go missing and so now use an external service.

</comment></comment><comment><USER12> I see a lot of replies on the mail side of things, but I don't really see anything detailing solutions for calendars.

Any recommendations on "the rest": calendar, notes, contacts?

I've looked at owncloud before, but that's a fairly large-footprint php project, are there any decent self-hosted alternatives, either as a suite or as separate programs?

<comment><USER13> As far as self hosting calendars and contacts are concerned, I'd recommend using a caldav/carddav server, I personally like Baikal [1], and Radicale [2] seems to be another good lightweight option. Contrary to Owncloud these two servers do not provide a web interface to check your calendar/contacts, but there are clients available for most platforms, including web clients if you need one.

[1] [http://sabre.io/baikal/](http://sabre.io/baikal/) [2] [http://radicale.org/](http://radicale.org/)

<comment><USER14> I've been using radicale, and it's been a huge pain in the ass. It took me days just to get the permissions right (behind Apache), and its interaction with DavDroid and the iOS calendars/addressbooks has been totally baffling. It doesn't help that the radicale mailing list seems to be no more.

Probably I'm blaming radicale for some of webdav's weirdness, but the whole process has been one of the most frustrating computing things I've done in years.

</comment></comment></comment><comment><USER15> Just since no one has pointed it out, have you considered ProtonMail? Swiss based, fully encrypted, hosted email service. Should give it a look.

</comment><comment><USER16> Sandstorm is quite a simple (at least relatively) and secure way to get set up with this.

<comment><USER17> afaict, there is no mail server in sandstorm. Where did you read this information?

</comment></comment><comment><USER10> Even if you host your own email server, your emails are still handled by routers and the destination server unencrypted. You are not trusting others much less than not hosting your own email.

If you have your own domain and you don't trust others with your conversations with others, I think you are better off hosting a chat server over an encrypted protocol, such as XMPP or IRC or [https://blog.okturtles.com/2015/11/five-open-source-slack- al...](https://blog.okturtles.com/2015/11/five-open-source-slack- alternatives/) . Persuading your contacts to use it is a problem though.

Calendar is a different thing though. As long as you have a CalDAV server and a CalDAV client you should be good to go.

Also related to selfhosting stuff: [https://sandstorm.io/](https://sandstorm.io/) is a project I've discovered some time ago and haven't been paying attention to, but it seems to have thrived pretty well.

</comment><comment><USER18> I've run my own email for about 4 years now -- I'm fairly tech savvy, but don't know much about email -- so was pleased that my "quick" solution has worked well.

I use Apple Server to host the email via SSL on a dedicated server, really easy to configure.

The key thing is deliverability - initially I had some problems with my email going into junk folders.

To get around this I send all email via a service called PostMarkApp ([http://www.postmarkapp.com](http://www.postmarkapp.com)) which allows you to setup SPF and DKIM records on your domain and therefore ensure emails are authenticated.

I get pretty close to 100% deliverability.

PostMarkApp also shows you open / browser stats, so it's quite useful when I wonder if someone has read a particular email.

Not sure if this would be secure enough, but has worked well for me with almost zero maintenance after setup.

</comment><comment><USER14> Six months ago I followed the Arstechnica guide[1] to setting up your own email server. The guide is old, and some adjustments were needed, but the essential advice was good. I did SPF, DKIM, TLS certificates, basically everything I could possibly do to keep on everyone's good side. In the first month or so, I only opened up to a few users, and told them to be careful about how they used the service right in the beginning.

Never had a single issue with blacklisting or non-delivery.

[1]: [http://arstechnica.com/information-technology/2014/02/how- to...](http://arstechnica.com/information-technology/2014/02/how-to-run-your- own-e-mail-server-with-your-own-domain-part-1/)

</comment><comment><USER19> It's not perfect, but YunoHost is a very big step forward in that direction and it's making progress [https://yunohost.org](https://yunohost.org)

And to fix the "ISP sucks" we have started to package an "just work out of the box" solution in the FFDN, a federation of local associative ISPs [https://internetcu.be/](https://internetcu.be/)

The trick is to use a "internet cleaning" VPN that gave you a static ip address and that this VPN is handled by an association in which you are a member and that you can trust.

</comment><comment><USER20> I'm sure it's not a popular view here, but why would you want to? I moved mail, etc. to Google; gmail is by far the nicest mail client I've ever used. I use it for my business and private e-mails, I move other businesses to Google because it's just so convenient. Why would you want to do all that yourself for €4 a month? I really don't think anyone at Google would want to read my e-mails but even if someone would, do I really care? I'm all for a bit of privacy, but I've seen no evidence of data abuse at these large mail providers.

<comment><AUTHOR> It's not for the money, I can think of more effective ways I can spend my time to save money. My reason is that I don't like the feeling of having these very personal conversations being stored on the harddisks of google. I might trust google right now with my email but when I no longer do they will still have those files and there will be nothing I can do to completely make sure they delete them.

<comment><USER21> The odds are that the other correspondent in your personal conversations is storing all their messages on Google's hard disks.

<comment><USER5> This is an excellent point. Your communication is only as secure as the weakest endpoint (in the same vein, perhaps your correspondents might be of the opposing viewpoint and might feel weird about their personal mails being stored by someone who's rolling his own IT and security).

</comment></comment></comment></comment><comment><USER22> A problem seems to be losing common media for message exchange. After experience with a bunch of instant messaging tools, invariably having to abandon them after focus shifts elsewhere, it's tempting to rely on something more of "common denominator". Email was that... and if it stops, then - what? phone?

This is an interesting problem of lack of standard. Hope [http://seif.place](http://seif.place) will help with that :) .

</comment><comment><USER23> Would it be possible to set something of a webmail client up with Mailchimp/sendgrid APIs? Get the flexibility and control of how your email works without the flagged as spam issue?

</comment><comment><USER24> Any one using Mail-in-a-Box ([https://mailinabox.email/](https://mailinabox.email/))? Seems good to me.

<comment><USER25> I would support this if it wasn't based on Ubuntu, especially 14.04. That is the last disto I'd trust as a secure mail server.

<comment><USER26> Why do you think Ubuntu is dead last among Linux distros in security? From my experience, they patch things quickly and inform about security issues promptly.

[http://www.ubuntu.com/usn/](http://www.ubuntu.com/usn/)

<comment><USER25> 1\. They often run out of date package versions.

2\. Their packaging team screws up packages regularly.

3\. They have insane defaults of many package configurations.

4\. They tend to do things their way rather than the standard way and come up with their own tools rather than using standard, well tested tooling / packages.

I could go on and on, but it's not a distro I'd ever let run on one of our servers, we used to run 100% Debian until CentOS 7 came out and in our eyes left it for dead when paired with the correct yum repos.

</comment></comment></comment></comment><comment><USER27> The first time I hosted my own email, on sendmail, it just worked. So I don't understand the question about setting it up. Configuring it for security took some study but it wasn't difficult. No more difficult than any other serious program I use.

Calendars are similar to forms on the web. Again, no more issues than normal so I don't get it.

<comment><USER28> Setting up an email server isn't hard.

Setting up an email server that won't get blacklisted by the major providers within a week of you setting up is difficult, time consuming, and often expensive.

<comment><USER27> You are saying that what I am doing will get me blacklisted, etc., but I am here to tell you it is not any of the things you say.

</comment></comment></comment><comment><USER29> Self-hosted owncloud works for me except for the gruesome woes every single time I try to update it.

<comment><USER30> Does OwnCloud support email too? I wasn't aware of this.

<comment><USER29> No it doesn't, unfortunately. I misunderstood OP's questions at first. You can connect owncloud to a mail server (a la Roundcube) but nothing more.

<comment><USER30> Maybe one day they'll make a plugin that does the same that Roundcube and other PHP email clients are capable of doing, that would at least make it a little smoother to have as an all in one email client.

</comment></comment></comment></comment><comment><USER31> postfix (SMTP), dovecot (IMAP), davical (CardDAV for addresses, CalDAV for calendars) have been working well for me for more than five years.

I experienced blacklisting when I switched to a newer dedicated server hardware recently, which meant new IP addresses. The only mail server that didn't accept mails from my new addresses was Hotmail / Outlook.com though. It was fixed after filling in their form and waiting a day. Never had trouble with Gmail.

</comment><comment><USER32> If you store your emails in a hosting provider then the hosting provider can read your emails. If you store your emails at your server at home then police can break your door plug in to your server and read your emails. Even if the disk is encripted they can read the encription key from the memory. Now I trust more Google than Microsoft, if you are non USA citizen of course. And I trust a foregn authority more than a local. This can change in for your case.

<comment><USER33> At least you know if the police have come for your mail.

In practice hosting your own mail provides some control over how to respond to a subpoena. If someone sues you the bar for getting the data by physical force is much higher than it is for having a third party turn it over.

On the other hand the bar for compromising your server is usually much lower than it is for gmail.

</comment></comment><comment><USER34> Because there is no money in that model.</comment>


FreeBSD Foundation Announces Capsicum Framework Project - <AUTHOR> http://lists.freebsd.org/pipermail/freebsd-announce/2013-April/001466.html

<comment><USER2> Some background on Capsicum, from <http://www.cl.cam.ac.uk/research/security/capsicum/>

Capsicum is a lightweight OS capability and sandbox framework developed at the University of Cambridge Computer Laboratory, supported by a grant from Google. Capsicum extends the POSIX API, providing several new OS primitives to support object-capability security on UNIX-like operating systems:

* capabilities - refined file descriptors with fine-grained rights

* capability mode - process sandboxes that deny access to global namespaces

* process descriptors - capability-centric process ID replacement

* anonymous shared memory objects - an extension to the POSIX shared memory API to support anonymous swap objects associated with file descriptors (capabilities)

* rtld-elf-cap - modified ELF run-time linker to construct sandboxed applications

* libcapsicum - library to create and use capabilities and sandboxed components

* libuserangel - library allowing sandboxed applications or components to interact with user angels, such as Power Boxes.

* chromium-capsicum - a version of Google's Chromium web browser that uses capability mode and capabilities to provide effective sandboxing of high-risk web page rendering.

There's also a video of Robert Watson's 2010 Capsicum talk at <http://www.youtube.com/watch?v=raNx9L4VH2k>

Edited to add: The FreeBSD Foundation plans to significantly increase spending on projects (such as this one) as well as full-time staff members in 2013: <https://news.ycombinator.com/item?id=5564478>

<comment><USER3> Hm yes, I know some of these words

</comment></comment><comment><USER4> Interesting to note Daniel Bernstein's take on least-privilege design, which Capsicum is an example of.

Bernstein wrote qmail, which can safely claim to be the first modern least- privilege mail server design, and one of the first modern least-privilege designs of any sort. qmail tries to derive some additional security from splitting up its activities into multiple components running with different credentials. Despite qmail's extremely impressive security record (it is one of the most impressive bits of secure code ever written), Bernstein considers his privilege-separation experiment a failure.

<http://cr.yp.to/qmail/qmailsec-20071101.pdf>

The problem is that minimizing the capabilities of a computer program often just moves the goalposts for an attacker. Too many times, unexpectedly conceding to an attacker some privileges on a target results in a compromise of all meaningful privileges, because attackers can use those new privileges to launch further attacks.

The problem is even harder in modern web applications, because breaking the operating system almost doesn't matter; all the attacker really needs is a working handle on the database.

<comment><USER5> I disagree with djb here: Although it's true that privilege separation rarely _eliminates_ vulnerabilities, I maintain that it can make vulnerabilities _far less dangerous_.

To take an example the Capsicum people are fond of: Decompression. zlib has a long history of vulnerabilities in decompression of corrupt data, so it's a natural thing to run inside a sandbox. djb's argument is "but a vulnerability in zlib is still bad because it can return incorrect output", which is true as far as it goes, but it completely misses the important point that it prevents the attacker from accessing anything not inside zlib's sandbox -- say, connections to a database.

<comment><USER4> I think Dan Bernstein is an absolutist, in the sense that he believes error- free ("invulnerable") programs are commercially achievable. I don't agree, but I think his perspective sheds some pretty valuable light.

<comment><USER5> I'm somewhere between the two of you: I think error-free programs are achievable, but I realize it's a huge amount of work and it's impossible to ever know for certain if you've succeeded. I see capsicum as something to help bridge the gap between "I don't _think_ there are any bugs in here" and "this program is safe to run".

<comment><USER6> There's always the great ivory tower known as Provable Programming.

<comment><USER7> Provable Programming provably requires non-Turing-complete languages.

Which isn't an insuperable barrier, to be sure, but it's a big piece of evidence against its practicality in actual commercial environments.

<comment><USER8> why has this been downvoted? if this is wrong, a simple "no, this is wrong. see e.g. blah" would have been nice.

<comment><USER9> Diagonal proofs like the Halting Problem say that in general you can not prove properties about all programs in a Turing complete language. Thus, there is a class of troublesome programs.

Likewise there is obviously a great number of programs in Turing complete languages that you can prove properties about. Thus, there is a class of pleasant programs (or [program, property] pairs).

We do not know for certain how many of the programs that we want to write that is in each class. I would venture a guess that >99% of all programs ever written are in the "nice" class. If it is really impossible to reason about some property of a program, why would you think it works?

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER10> Anyone familiar enough with such things to compare its theoretical or practical abilities compared with the seccomp/namespaces/syscall filters/selinux world? I mean besides their horribly disjoint nature.

<comment><USER11> One of the problems with security mechanisms based around system-call interposition (such as systrace) is that it's very hard to avoid concurrency vulnerabilities. To avoid this, you need to push the security mechanisms down into the kernel, as with SELinux. The downside is that configurable policy becomes harder that way. Capsicum is all about configurable and extensible security policy using capabilities.

There's a nice explanation of concurrency vulnerabilities in chapter 2 of Robert Watson's thesis, and a comparison of Capsicum vs other security mechanisms in chapter 5. It's worth looking at, if you're interested in these issues:

<http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-818.html>

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


The Electric Flight of Spiders - <AUTHOR> https://www.theatlantic.com/science/archive/2018/07/the-electric-flight-of-spiders/564437/?single_page=true <comment><USER2> I'm loving all these spider articles that have cropped up on hacker news and elsewhere [0]-[4].

I used to be deathly afraid of spiders, but all these articles and videos over the years have eliminated my fear of them. I like having some around.

[0]: The extraordinary life and death of the world's oldest known spider - [https://news.ycombinator.com/item?id=16992596](https://news.ycombinator.com/item?id=16992596)

[1]: Spiders eat an astronomical amount of insects - [https://news.ycombinator.com/item?id=15887468](https://news.ycombinator.com/item?id=15887468)

[2]: How spiders fly - [https://news.ycombinator.com/item?id=17398383](https://news.ycombinator.com/item?id=17398383)

[3]: How I ended up with pet jumping spiders - [https://medium.com/@melissamcewen/how-i-ended-up-with-pet- ju...](https://medium.com/@melissamcewen/how-i-ended-up-with-pet-jumping- spiders-187d70a3e296)

[4]: Lucas the spider - [https://www.youtube.com/user/joshuaslice](https://www.youtube.com/user/joshuaslice)

<comment><USER3> The jumping/portia spiders are the coolest. Cracked.com had an article on diabolical insects with them featured in it.

[http://www.cracked.com/article_109_natures-6-most- diabolical...](http://www.cracked.com/article_109_natures-6-most-diabolical- predators.html)

I'll excerpt the relevant part for folks that are squeamish or at work given Cracked is a bit NSFW:

"Each individual Portia employs their own unique and vast arsenal of dastardly impersonations to trick, ensnare and consume their prey. A Portia spider might strum a pattern on a strand to impersonate the buzzing of a fly caught in another spider's web, while a different spider of the same exact species might opt to catch a real fly to throw in the web and, while the prey spider is distracted, sneak up behind it. It may pretend to be inanimate by moving only in the wind, it may observe and duplicate another spider's entire mating ritual or sometimes it might even build a complete web of its own that attaches to its victim's, thereby creating a trap out of the spider's own trap."

They're just too friggin' smart! I make sure nobody squashes them at my house so they do their important work of eating other spiders.

One time I watched one do a nice ambush. Target spider had a web in the corner it almost always sat on. The invisible, jumping spider apparently waited until the target descended from its web to (I guess) start extending it. Jumping spider ran out of nowhere full-speed across ceiling, jumped past web onto that single strand, and started climbing down at spider. Brief battle ensued. The jumping spider was literally sitting between the target's ass and web with nowhere for it to go. It dropped a few inches to create distance. Then, just cut its own supporting line to drop off the ceiling abandoning its original web. Jumping spider climbed back up it going back where it came from. Fun to watch.

<comment><USER4> I loved watching this: [https://www.youtube.com/watch?v=UDtlvZGmHYk](https://www.youtube.com/watch?v=UDtlvZGmHYk)

</comment></comment></comment><comment><USER5> In freshman physics, when you first learn about electrostatics, one of the problems you get to work is the "how much charge would you need to float yourself off the ground." It is enough that you usually violate the dielectric constant of the air and discharge into the air around you but still, its a fun exercise. To see that Spiders use this to fly is pretty amazing to me.

<comment><USER6> I'm also interested in this, perhaps using an aluminized mylar balloon or a large wire mesh with a Van der Graaf Generator and/or electron gun to maintain the charge. There's been a fair amount of research on electrohydrodynamic (EHD) vehicles (lifters), but I haven't seen any experiments using a large charged surface area to create an effect like buoyancy.

[http://jnaudin.free.fr/lifters/main.htm](http://jnaudin.free.fr/lifters/main.htm)

<comment><USER5> If you wanted to be super cool you would use a graphene sphere. Manufacturing such a sphere would be a fun challenge.

</comment></comment></comment><comment><USER7> "Spiders float in the air using electric fields" might be a better title. I initially thought this was going to be a detailed explanation of how spiders use water's surface tension (due to water's electric dipole) to float on ponds. This article is actually about "ballooning". Here's an excerpt from the abstract:

> To disperse, spiders "balloon," whereby they climb to the top of a > prominence, let out silk, and float away. The prevailing view is that drag > forces from light wind allow spiders to become airborne, yet ballooning > mechanisms are not fully explained by current aerodynamic models. The global > atmospheric electric circuit and the resulting atmospheric potential > gradient (APG) provide an additional force that has been proposed to explain > ballooning.

I've left out some of their in-line references.

</comment><comment><USER8> > Even on sunny days with cloudless skies, the air carries a voltage of around > 100 volts for every meter above the ground.

This is interesting. Is there any way we could use a tethered balloon as a power generation system to harvest this energy?

<comment><USER9> Not really, the energy density is fairly low. Except during thunderstorms of course.

Shoudn't be too hard to check. Get ten metres of rigid plastic pipe and ten metres of insulated wire bared at the ends so that you can measure the voltage between the top and ground.

Set it up vertically at least 20 m from everything else. Measure the voltage between top and bottom with a good quality high impedance voltmeter.

Now add another ten metre length of wire and a resistor to complete the circuit and use some of the power. Measure the voltage again.

The voltages and the resistance allow you to calculate the equivalent impedance of the source.

I'd be very surprised if no one has already done this and probably in a much more sophisticated fashion.

</comment></comment><comment><USER10> Could this electrostatically-based flight phenomenon be reproduced at a larger scale, or is there some natural limit to the amount of upward force generated?

<comment> martin-adams So if you could produce a device to create the electricity field that could work at a larger scale, and such device could be carried by the field itself, then could it be possible to create a hovering or flying vehicle.

</comment></comment><comment><USER11> Oooh that's how they take off! One time I was on a high mountain and there were so many tiny spiders floating above they made a glittering halo around the sun.

I still wonder how they get so high though. Shouldn't the charge diffuse as they lose their connection to the ground?

</comment><comment><USER12> At first I thought the spiders' abilities were ballooning due to our electricity consumption and I was slightly afraid.

But it's about their ability to balloon and electrical variation in altitude.

</comment><comment><USER13> Official video summary: [https://youtu.be/GRrUxi6d7so](https://youtu.be/GRrUxi6d7so)

</comment><comment><USER14> A video demonstration of this phenomenon by NYTimes: [https://www.youtube.com/watch?v=VDL9VxLqdvw](https://www.youtube.com/watch?v=VDL9VxLqdvw)

and David Attenborough: [https://www.youtube.com/watch?v=wnV4f2oXKUs](https://www.youtube.com/watch?v=wnV4f2oXKUs)

</comment><comment><USER15> Marvel will have to rethink Spiderman's powers. So interesting of a finding.

</comment><comment><USER16> The front of my car sometimes looks like a insect horror movie.

What about airplanes? Do spiders end up at the nose of an airplane? Or are they pushed away by the pressure in front of the plane?

</comment><comment><USER17> I didn't know there was an electrical variation in altitude.

<comment><USER18> If there wasn't, how would lightning happen?

<comment><USER19> Without knowing meteorology, I would think it had to do with storm clouds / volcanoes more than height.

</comment></comment></comment><comment><USER20> Anyone live in eastern Australia? ;)</comment>


Matlab alternative for math & science students - <AUTHOR> http://jasymchat.com

<comment><USER2> GNU Octave ([http://www.gnu.org/software/octave/](http://www.gnu.org/software/octave/)) is a great open source alternative to Matlab. I can only recommend the book "GNU Octave Beginner's Guide" ([http://www.packtpub.com/gnu-octave-beginners- guide/book](http://www.packtpub.com/gnu-octave-beginners-guide/book)).

<comment><AUTHOR> agree...Jasymchat is more a light-weight alternative which works well for most undergrad course work. And it is also mobile...but for serious work definitely suggest Octave.</comment></comment>