Ask HN: How do you electronically store your notes?  - <AUTHOR> Hi HN,
I am about to embark on a project entering text from handwritten class notes into the computer.
The data is structured around verses of scriptural literature which vary in format but generally forming hierarchical structures down to the atomic 'mantra/verse'.
I would like this project to remain flexible but I have a somewhat vision of annotating (and linking, wiki style) text to shown relevance with other sources of culture (like excerpts from a book).
Right now, a focus on data entry is important. What choices can be made now to maintain flexibility later? Latex? XML? SQL database? <comment><USER2> If you want to "just start, already" but have an open format, somebody somewhere recently mentioned the locally installed wiki-ish note database and editor Zim. As I recall, they do/did tech support and started using is as a simple, local way to maintain a personal database of references and notes-to- self.

I was curious and put it on one old machine I've been using a fair amount, recently. So far, I like it, although I haven't gone very deep into its features (not that the feature set is necessarily that deep, anyway).

[http://zim-wiki.org/](http://zim-wiki.org/)

P.S. Just saw your "already invested in Vim" comment reply, so maybe you are looking for something a bit more technical and less "integrated" than this.

</comment><comment><USER3> org-mode in emacs. It can do hyperlinks, tables, structure, export to various formats, etc. Its very own little kitchen sink within the kitchen sink :-)

<comment><AUTHOR> Hi,

Thanks for your reply.

I've invested myself in vim as it stands, but will research along the lines of your recommendation.

<comment><USER4> Look up evil-mode. It puts vim keybindings into emacs, and it works nicely alongside org-mode. You can edit and navigate vim-style but you still get all the org-mode commands (collapse/uncollapse headers with TAB, put in timestamps with C-u C-c . RETURN, etc.)

</comment></comment></comment><comment><USER5> Private GitHub gists are pretty handy. Version controlled, your choice of language, use them as datastores (write your own client) or something more like markdown interlinked documents, etc...

An actual repo would have even more features, like: [https://github.com/blog/1601-see-your-csvs](https://github.com/blog/1601-see- your-csvs)

<comment><AUTHOR> Thanks, this seems like a good integration.

Any suggestions regarding a specific choice of data format? Latex? Markdown? Etc.

</comment></comment><comment><USER6> I use a combo of Evernote and OneNote (Windows). I'd think either would be fine in your case. Both have folders/hierarchies that allow for quick nav/search.

<comment><AUTHOR> Hi,

I am running Linux mint at the moment so this is unfortunately not really an option. Besides, these programs don't really lend for data malleability, if you will.

</comment></comment><comment><USER7> A gollum wiki. [https://github.com/gollum/gollum/wiki](https://github.com/gollum/gollum/wiki)

</comment><comment><USER8> You're on Linux, so with your given parameters, it sounds like a local install of MediaWiki or similar software would be your best bet.

</comment><comment><USER9> I use Trello, great API, free plan, mobile iOS and Android clients that work, multiple users.</comment>


Operation Mockingbird - <AUTHOR> https://en.wikipedia.org/wiki/Operation_Mockingbird <comment><USER2> Apropos considering the "fake news" meme presently seizing the interwebs. But that may be the sort of "fake news" folks hesitate to confront.

<comment><AUTHOR> People need to educate themselves about corporate medias 'fake news' and how long they have been pedaling it.

This hysteria being whipped up by them has an agenda. And its more then likely an attempt to push for censorship of the independant free press.</comment></comment>


Thank you Apple - <AUTHOR> http://commandcenter.blogspot.com/2012/09/thank-you-apple.html <comment><USER2> _It had surprised me when Lion came out that the installation was done by an "app", not as a bootable image. This is an unnecessary complication for those of us that need to maintain machines. Earlier, when updating a different machine, I had learned how painful this could be when the installation app destroyed the boot sector and I needed to reinstall Snow Leopard from DVD, and then upgrade that to a version of the system recent enough to run the Lion installer app. As will become apparent, had Lion come as a bootable image things might have gone more smoothly._

Lion and Mountain Lion installers contain images which can easily be converted to ISO:

[http://tinyapps.org/blog/mac/201209130700_convert_dmg_to_iso...](http://tinyapps.org/blog/mac/201209130700_convert_dmg_to_iso.html)

and there are many more options and approaches:

[http://www.tech- recipes.com/rx/2628/install_os_x_from_dmg_fi...](http://www.tech- recipes.com/rx/2628/install_os_x_from_dmg_file/)

<http://0xced.blogspot.com/2009/08/booting-from-dmg.html>

[http://blogchampion.com/2011/03/12/how-to-create-a- bootable-...](http://blogchampion.com/2011/03/12/how-to-create-a-bootable-usb- drive-installer-from-a-dmg-package-in-mac-os-x/)

<comment><USER3> Yeah. I remember going through Snow L -> Lion. I wanted a clean system so had to make an ISO. Process reminded me a linux install from USB from 10 years back.

And I lost iPhoto. Because suddenly my Macbook Air stopped being eligible for free iPhoto.

<comment><USER4> I had an annoying scenario recently.

I reinstalled Snow L on an older machine and then could no longer reinstall iphoto. I'd paid for it on my app store account but there was no way to install the older version (and I couldn't upgrade to the newer version).

Once again reinforced the danger of the cloud hosted licensing model; software I paid for wasn't actually mine to keep/use.

</comment></comment></comment><comment><USER5> (This does not in any way excuse anything he encountered. That is and will always remain inexcusable.)

Apple is aware of those problems and hard at work fixing them. All current Macs, for example, now come with Internet Recovery, meaning it is possible to boot them into the recovery manager (and from there it's possible to run Disk Utility, the Terminal or the installer), even with a completely empty HDD. All the iLife apps you get with your Mac (and all apps you buy in the App Store) are automatically tied to your Apple ID, meaning you can download them as often as you want. You cannot even buy any software on CDs from Apple anymore (the lone exception to that is Logic Studio).

I assume (hope!) that all Time Machine bugs have been fixed, but do not know. It seems weird that even the latest version of OS X Lion would come with those bugs, so I'm not sure what's going on there. At any rate, the experience he had is unacceptable.

<comment><USER6> I have a "non current" macbook air that I've been wanting to do a security clean install on forever but it doesn't qualify for internet recovery for some reason. Its a 2010 Macbook Air. How do I do a secure wipe of the drive and reinstall ML on this thing?

<comment><USER5> It's pretty easy: <http://eggfreckles.net/notes/installing-mountain-lion- clean/>

I have used this procedure many times, it works like a charm.

However, I do want Apple to provide a more obvious way of doing just that. It would be great if their tool for creating a bootable recovery manager worked just with the OS X install app as a source.

But to be honest, I do not think that doing a clean install is a good idea for the most people and for defect HDDs, new Macs at least come with internet recovery (but the older ones are still a problem).

</comment></comment></comment><comment><USER7> I think there's one thing he didn't try that would've saved him some work. The path he took was (skipping some early steps):

1\. Backup under Snow Leopard via Time Machine

2\. Replace drive

3\. Install fresh copy of Snow Leopard

4\. Upgrade to Lion

5\. Attempt to use Migration Assistant to restore from the Time Machine backup taken in step (1).

This failed at step (5) and he ended up having to do lots of manual work to copy his data and apps out of the TM backup.

I think if he restored from the the Time Machine backup after replacing the drive, then attempted the Lion upgrade, he'd have been successful. Minimally, it would've been a combination of well tested scenarios. I'll bet not as much testing went into using Migration Assistant under Lion against Snow Leopard TM backups.

<comment><USER8> I'm not a fan of Time Machine. I just use Carbon Copy Cloner to make a bootable version on a USB drive. If things go wrong I boot from it and clone it back to the internal drive.

</comment></comment><comment><USER9> I think it's interesting to point out that this is Rob Pike.

<http://en.wikipedia.org/wiki/Rob_Pike>

<comment><USER10> Interesting in that his industry veteran status gives this merit or interesting in that his employment makes him a shill?

<comment><USER11> Interesting in that when it comes to computers, he knows what he's doing.

<comment><USER12> Does he?

Not a knock on Rob Pike, obviously a very smart dude, but knowing computers at one point doesn't mean you've invested the time to keep up with them since. My dad was a network engineer in the 90's and early 00's and I learned a lot from him, but these days, when he needs to pick out a laptop or something, he asks me. I'm more connected to it than he is now, because he has other things on his plate.

<comment><USER13> If _Rob Pike_ can be said to be too technically unfamiliar for an Apple product, then there is something very very wrong with Apple's expectations of their users.

<comment><USER12> Is he too technically unfamiliar? Or is he trying to leverage assumed domain knowledge in an incorrect way? I mean, I'm not a programming languages expert. I couldn't work on Go. But I _do_ know that the bootable OS X installer is within the app package upon which he was casting aspersions; I've used it myself to reinstall OS X and to install it on different machines.

Some friends of mine who are professionals in other fields have noted (not about me, I hope, but I know that I'm guilty of this at times as well) that "computer people" have no end of cases where they think their preexisting knowledge is enough to solve a problem when it has little or no bearing on the topic at hand (politics, biology, whatever). I see no reason that can't also be true within the computer field as well. Because a pretty cursory Google _would_ have explained all the things people elsewhere in this thread have explained about how to actually do this--but he didn't do it, relied on his own previous knowledge, and it didn't really apply.

<comment><USER13> It doesn't really sound like he got himself into this situation because he struck out on his own and broke something.

It sounds like he got into this situation by calling up _and trusted_ customer support and doing what any normal consumer does: then calling the fixup guy who is supposed to do this stuff professionally.

They said to make a backup and everything would work. He made a backup and it didn't work. From there, everything got worse.

I know that is pretty much the opposite of what I, an undoubtedly overzealous "technology guy", would try to do. Though, as a technology guy I probably would have said _"Fuck it, lets install linux"_ not even halfway through the trouble he was having (and if it were still 2003 and the linux distro I was trying to install were Gentoo, the effort required between the two probably would have just about evened out).

Sticking with it and trying to work with customer service is a very _"normal trusting consumer"_ thing to do.

</comment></comment></comment></comment></comment></comment></comment><comment><USER14> IMHO not having install media as the default option is a problem. It doesn't matter if all the media does is boot up a network stack and FTP it from somewhere and then run it but recovery scenarios aren't something you should have to twist yourself into a loop to solve.

One of the advantages of the App Store model is that software is (AFAIK) easily redownloaded and reinstalled, so much so that I know people who have re-bought Aperture (for $80) on the App Store just for the convenience (plus then it can go on multiple Macs).

Why Rob Pike wouldn't fork over $80 for Aperture and save himself the hassle is beyond me. You can say "it's the principle of the thing; I've already paid for it!" but really? What is your time worth?

iWork can be had on the App Store too. Photoshop obviously can't but Photoshop should be recoverable somehow (right?).

These days I have a box with the few disks I need (Win7, MS Office), I store my personal files on Dropbox and any media gets stored on a hard disk. If my Macbook Air got stolen or just died I'd be up and running within 2 hours of getting a new one.

The only real annoyance for me is changing what computer your iDevices sync to. THAT is a major PITA. If you are migrating machines it's not so bad (but harder than it should be). But otherwise you need to backup, wipe it and reinstall everything and even then you lose all your iOS folders and so forth.

I don't like the iMacs because they're not built for replacing hard disks (amongst other things). The Mac Mini however is. If this had happened to me I would've been shelling out money to avoid the hassle and the whole thing would've been over in a day or two.

The moral I get from this post isn't how Apple is making things harder than they need to be (which they clearly are): it's that you shouldn't get caught up on the small shit that doesn't matter.

<comment><USER3> >>>> Why Rob Pike wouldn't fork over $80 for Aperture and save himself the hassle is beyond me. You can say "it's the principle of the thing; I've already paid for it!" but really? What is your time worth?

Well, the trouble with that approach is that money votes. When you pay this extra $80 you reinforce the behavior.

<comment><USER15> And you wouldn't want to reinforce the behavior of providing a time-saving service for money?

<comment><USER3> I don't want cloud service providers forcing me to buy an application a SECOND time, by limiting my access to installer.

And I'd really prefer not to pay second time. Because that reinforces the behavior of profiting by screwing people up. Maybe it saves my time. But it is unethical.

<comment><USER16> They didn't limit access to the installer, he was trying to bring it back from a Time Machine backup. If he had the original disc it would work fine.

<comment><USER3> Same thing really. He couldn't reinstall application that he owned. Because access to the installer was convoluted.

<comment><USER16> You bought it on a CD, keep the CD.

Before downloading apps was the norm, _no_ company would issue a second copy of something you bought.

<comment><USER3> Well, before advent of app store I NEVER had a case than I couldn't reinstall application that I've purchased.

And with the app store, in just a year or so I already had a couple of cases when I lost access to an installer. One was that I lost iPhoto, with OS upgrade on Air. Another, temporarily, for around a week I had no access to XCode installer [because of some screw up in the store].

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER17> My Mac Pro running 10.8 has some issues such as applications with blank icons, pixelated icons, etc. I was told to boot into safe mode (which I tried about 5x) and it hangs at about 1/4 into it.

It seems pretty silly to include a "safe mode" that won't even allow someone to use it. I always end up holding the power switch in for a few seconds until I reboot into normal mode, which apparently includes having blank/pixelated icons :-/

<comment><USER18> Disk utility's repair disk and repair disk permissions functions, which are run as part of a safe boot, can take quite some time to complete their job.

I would just wait.

However, if you would _really_ like to know where your boot is getting stuck, do a verbose boot, which is the same thing as a safe boot, except it replaces the gray Apple screen fairly (and usefully) verbosely.

</comment></comment><comment><USER19> Sounds like he had a bad day. Oh well. Probably as much of an unproductive waste of time to write this long, passive-aggressive blog post.

<comment><USER20> _Sounds like he had a bad day._

Did you read the whole thing?

 _It took weeks to get everything working again properly._

 _Because I could prove that I had paid for the software, Apple agreed to send me fresh installation disks for everything of theirs but Aperture, but that would take time. In fact, it took almost a month for the iWork DVD to arrive, which is unacceptably long. I even needed to call twice to remind them before the disks were shipped._

<comment><USER21> That's why app stores exist... you think Microsoft would have been faster if they sent you MS Office?

</comment></comment></comment><comment><USER22> I'm mostly amazed that the person being sent to replace the hard drive with a blank one didn't think to bring installation media...

</comment><comment><USER23> I'm also having one of those days ... I just updated Ubuntu on a newish machine and now have no sound and snow on the screen where video had been. Some days I hate computers and hope they're just a passing fad.

</comment><comment><USER24> You seem like a smart guy, but heres an FYI: the Lion installation app, as well as ML installer, is just a wrapper application with preflight functions for the installer. This app wrapper contains the disk image of the Lion installer that functions just like any other disk image of OS X. To find the disk image for lion in the "Install Lion.app" app wrapper, you right click on the app and click show contents, find a resources folder and bam, there it is. The disk image can be burned to DVD or restored to a flash drive using disk utility. No excuses now, they didn't fail anyone. Time machine has never failed me. The only time things get dicey is when you encrypt, using vault or etc, large file sets or systems. All you needed to do from the first go is 1) back up to time machine, 2) install new drive, 3) restore the time machine backup with option at boot (snow leopard install disc might be required, but you scratched your disc, not apples fault), if disc is scratched for DVD install, there's a good chance you could have still restored a usable copy of it to a flash drive or a new DMG on your desktop using disk utility. 4) restore the disk image of lion from the install lion.app, the DMG you were unaware of and bitched so much about, to the flash drive and 5) upgrade your SL to lion using option at boot. Also, before backing up a dying drive, make sure to repair permissions using disk utility. Also, if you kept your old drive, you can buy an enclosure for 30$ and turn the drive into an external disk and restore your original installation. And not the time machine backup. Works every time even with dying unrepairable drives.. Cheers.

</comment><comment><USER25> I have to laugh at hose of you who fault Rob for following anything but the most mainstream recourse in resolving his crisis as proof that he's to blame, didn't do his homework, etc. Consider this: despite the (somewhat strange, in my mind) phenomenon of various Plan 9 alumni (and Google employees in general) using Macbooks for daily use, the fact that these folks are proven experts at bringing up ports of their own research operating systems on new machines from just their hardware documentation should key you into the fact that these Apple products were purchased with all the expectations of an appliance! I.e., not things to be mucked around with, but the result of a commercial transaction that ought to be judged on its capacity to perform as advertised and supported if necessary.

Getting a closed, commercial product (with a baroque unix base) to bend over backwards to perform basic functions like backup and installation is not a Plan 9 user's of fun. I would hazard a guess that the greatest reason Rob got burned could have been the naive expectation that programs will perform their designated task simply and correctly?

Considering Apple's user-base, on the other hand, idiot proofing the system seems to be a much higher priority. Which is the main reason why I still don't understand why Plan 9 people can stand to use Macs.

</comment><comment><USER26> After witnessing my dad's troubles with TimeMachine, I bought a copy of SuperDuper!.

It's amazing software, and it saved me once now, it's been only a year since I've been using it. Hard-drive fails? Plug in external one, and use your computer as if nothing happened.

Their "smart update" feature is very useful.

[http://www.shirt- pocket.com/SuperDuper/SuperDuperDescription...](http://www.shirt- pocket.com/SuperDuper/SuperDuperDescription.html)

</comment><comment><USER27> I wanted to blog about something similar myself, but currently lack a blog. Apple's rejection of physical media is, I would argue, extremely harmful.

I have an old, 2008 Macbook (not Pro) 4,1. The old white plastic kind. Lion performs atrociously (at best) on it, so around half a year ago I installed Linux on it. Recently, I got around to buying a new laptop (a Lenovo), and wanted to restore OSX on the old Macbook in order to give it to family.

I figured off the bat I'd do a clean install of Mountain Lion. I have old Leopard installation media, but that's a dead upgrade path: you can't buy Snow Leopard media anymore, so you cannot upgrade it. Apple don't sell physical media for Mountain Lion either, so I went to a friend's house, logged into the Mac App store, purchased and downloaded Mountain Lion.

When I got home, the installer (which took an hour or so to image onto a USB stick) didn't work. I figured it might be balking on the HDD being Linux, so dd'd it. Nope. It turns out Mountain Lion is incompatible with my hardware.

This is where the vortex begins. I returned to my friend, and tried to get the Lion installer off the App Store (on my account), which I had previously purchased. No dice. Apple have removed Lion now that Mountain Lion is out.

I tried to install the copy of Snow Leopard my friend had. Not possible. As OEM media, it's got (very basic, admittedly) DRM onboard which restricts the installation to his hardware.

I tried to get the copy of Snow Leopard I had originally installed, when my previous employer had (kindly) purchased a stack of us personal copies alongside upgrades for work machines. Nope; they'd stopped using Macs and those were gone.

Being frustrated, I figured I'd install Leopard on the laptop and be done with it. Nope. The disc, it turns out, is scratched.

At this stage, I called Apple. I asked what I could do. I was advised I could purchase a physical copy of Lion off them, if I paid full price -- despite _already having purchased it_ on the App Store. Frustrated, but at this stage just wanting to be rid of the device, I agreed. It turns out this was also not possible. Apple's support is in Australia, and NZ can't get the physical media (at least, I believe this to be the case; I may have conflated the issue on the phone with needing to get the media within a week).

The next day, I took the laptop to a Yoobee store (our Apple store equivalent). They told me they'd have to ship the laptop to the support centre to fix it.

So, to recap: I can't install Mountain Lion, because my hardware is too old. I can't get physical media for Snow Leopard or Lion, because Apple no longer sell it. I can't retrieve a copy of Lion from the app store and create my own, because Apple has removed it. I can't install Leopard, because my media is damaged (not Apple's fault) -- but even if I could, it's unsupported and with no physical media, there's no upgrade path. The only solution was to pay to ship the laptop off to a support centre. Ultimately, I was very lucky to find another friend on IRC who still had a Lion USB stick he'd imaged earlier, but the fact I needed to do this is... well, awful.

This is a _terrible_ customer support situation. I'll admit it's compounded by the fact I'm in New Zealand, and we have no Apple stores (fair enough: our entire population is less than several US cities), so support is harder to come by. I'll admit that, having installed Linux, I'm probably in somewhat of a minority. However, Apple's forced hardware deprecation, and removal of physical media, have made it almost literally impossible to restore a working copy of OSX on their own hardware.

<comment><USER28> A bit of toothpaste diluted with water, and a gentle fingertip, may take that scratch out of your Leopard disc. _Do less than you think is necessary_ , then stop and assess.

In part, it seems some people "have the touch" for such work. I've fixed up a few abused (by others) music CD's this way.

<comment><USER29> [http://thepiratebay.se/torrent/4179024/Mac_OS_X_10.5_Leopard...](http://thepiratebay.se/torrent/4179024/Mac_OS_X_10.5_Leopard_Install_DVD_- _full_iso_image)

[http://thepiratebay.se/torrent/5068890/Mac_OS_X_10.6_Snow_Le...](http://thepiratebay.se/torrent/5068890/Mac_OS_X_10.6_Snow_Leopard_\(Final_Retail\))

</comment></comment></comment><comment><USER30> So I may come off as a grumpy old man, and I do sympathize with the op ... but in this day in age, it's only _that_ much more important to keep manual backups of serial numbers, passwords, installers ...

I trust Apple, Windows and Linux enough to not ruin my life, but not enough to keep me 100% safe.

Passwords: Personal & Business kept in LastPass and a copy in KeePass (synced in dropbox to 3 devices). Client passwords stored in Keepass + manual copies on digital client folders (secured files) + notes in a locked safe.

Games + apps: Digital downloads loaded into Raid 5 array, backed up on server, backed up onto DVD. serials/usernames/download links saved in cloud mail server + keypass

Documents: Saved to external HD, saved to raid 5, rsynced to private VPS, rysynced to downstairs server.

There is absolutely no excuse for losing passwords and misplacing things like that. That part of the story I believe it all the ops fault.

</comment><comment><USER31> There were several articles recently where I was reminded of the Linux Genuine Advantage satire website:

<http://www.linuxgenuineadvantage.org/>

> Did you wake up this morning and say "I wish someone would figure out a way > to let me do less with my computer"?

</comment><comment><USER32> There is no way he had a core duo system that is only 4 years old. Apple only made core duo MacBooks in early 2006.

<comment><USER33> #1. It's an iMac.

#2. You are wrong. [http://www.everymac.com/systems/apple/imac/specs/imac- core-2...](http://www.everymac.com/systems/apple/imac/specs/imac- core-2-duo-3.33-27-inch-aluminum-late-2009-specs.html)

<comment><USER5> 1) He was specifically talking about his laptop.

2) You are wrong. Core Duo, not Core 2 Duo. There is a difference. Apple only sold Core Duos for a very short time in 2006, right after their switch to Intel. At the latest, he could have bought a MacBook with a Core Duo on November 5, 2006. After that date, Apple discontinued the last one. So his MacBook is at least nearly six years old.

<comment><USER33> Then I'm sure he meant Core 2 and made a mistake, because I'd sure he wouldn't miss the computer's age by 50% if he purchased it.

<comment><USER5> No, it's pretty certain he meant Core Duo since (and that was the problem he was running into) all Core 2 Duo MacBooks support Lion while Core Duo MacBooks do not.

It's easy to massively mis-estimate the age of the stuff you own. Happened often enough to myself, so I'm not really surprised about that.

<comment><USER33> Right, I definitely missed that, I read this article in three parts while making lunch and clearly skipped some paragraphs. It was my mistake that I though Lion was supported on these machines. I have an old Core 2 that runs Lion (poorly) but will not run Mountain Lion due to the crappy Intel graphics, not because of the processor.

</comment></comment></comment></comment></comment></comment><comment><USER34> Technology sucks [http://www.hanselman.com/blog/EverythingsBrokenAndNobodysUps...](http://www.hanselman.com/blog/EverythingsBrokenAndNobodysUpset.aspx)

</comment><comment><USER35> Why didn't he call AppleCare back?

All he needed to do, with an Internet connection, was power on holding Command+R and the Mac does the rest (formats the new drive and creates a recovery partition, then, boots to it, and one of the options there is to restore the entire computer from a Time Machine backup).

Done.

He made this needlessly complicated, and really should have just called AppleCare back, as they could have easily walked him through these steps.

</comment><comment><USER36> This post is riveting. No really. Bewildering to say the least. As the post drags on and on the reoccurring "Thank you Apple" takes on an increasingly sarcastic tone.

Regardless of the author's fluency with computers (who really cares?) one can only marvel at the sheer absurdity in squandering the better part of a day (or was that several days?) mucking around with OS updates. Really? What a colossal waste of time.

<comment><USER37> He is not merely "fluent with computers." He co-created three operating systems and at least one programming language, _including_ the OS Apple managed to hinder him from installing. If your process is beyond him, your process is very, very broken.

<comment><USER38> Thing is, it doesn't seem to be beyond quite a few people here or elsewhere on the Internet. Appealing to authority is no way to prove a point. I wouldn't trust an architect to actually lay bricks.

</comment></comment></comment><comment><USER39> I recently had problems migrating to 10.8 so I just formatted my computer and reloaded the data parts. Still not fun having to reload apps but I'm at least glad that app reloading is simpler than what it used to be when I used Windows. I've tried to kee my computing as data-focused as possible...and hope that big commercial packages, like Photoshop, do their job in surviving OS upgrades

</comment><comment><USER40> In my experience, Time Machine works great. What doesn't work great are the absolute pieces of crap that Seagate and Western Digital are pawning off on us as viable backup solutions. They are just plain garbage. The controllers are unstable, and the drives are invariably refurbished. (And don't even get me started on the 2.5" drives with embedded USB controllers and no access to SATA ports.)

I went through a couple Seagates and a couple WD's, each of which would corrupt the Time Machine volume repeatedly. The last straw came when I had an internal drive failure on my MBP, and my existing Time Machine drive would not even mount, and Disk Warrior, Drive Genius, and TechTool Pro (in that order) were of no help.

I switched to using a Thermaltake USB3 dock, with 3.5" WD Enterprise drives. I have not had a single issue since. You get what you pay for in hard drives. If you are relying upon them for backup - don't go cheap. It isn't worth it!

<comment><USER33> Everyone should also have a remote backup anyway. Anyone relying on local hard drives to secure their data are completely naive. Not that I DON'T use a local, it's great for quick and easy file backup and transfer, but I sure as hell don't rely on that $100 drive to work correctly and with remote backup, I'm sure not going to spend more than that on a local drive. If your data doesn't exist in three places, one remote, it doesn't exist. Ask Francis Coppola about how well having one local backup worked out. <http://news.bbc.co.uk/2/hi/entertainment/7019644.stm>

Anyway, you're right about everything you said in your post, but just so people know, you can pay $20K for a backup array and if you don't have a remote, one fire makes that backup meaningless. Crash Plan, Carbonite, Backblaze, etc etc (AWS Glacier anyone?) all these services are so cheap you'd be insane not to just drop the $5 a month if your data is valuable.

</comment></comment><comment><USER41> If you use FileVault on your main drive or on your Time Machine, here are some tips I picked up on Lion, which might make your life easier. Things may have changed, but should still apply to Mountain Lion.

On each machine you have, download the Lion Installer app via the App Store. The app seems to be different for different models of Mac. From experience, it seems one model Mac might not be able to use the installer from a different model Mac. Open the app package and burn the ESDInstall.dmg to a USB stick to use as an installer.

Using the USB installer, erase the drive as a single partition, and perform a clean install of Lion. This ensures the recovery partition is created on the drive.

Launching the USB installer again, format the main partition and then restore from your encrypted Time Machine.

The partition you are restoring to is unencrypted so when the restore is complete, reboot your Mac, and manually enable FileVault (if you want it).

</comment><comment><USER42> It really seems like the entire point of this article was the author declaring, boldly "I don't know how to use OS X," and that's Apple's fault.

They're not without issue, but I've done every single thing he's complained about not being possible……except installing an OS over Target Disk……but that's a stupid idea anyway.

</comment><comment><USER43> Same here for the AppStore, which happily took my money and I still can't download Mountain, because I am in the "wrong" country.

Linux is running fine instead.

<http://news.ycombinator.com/item?id=4433082>

</comment><comment><USER44> Can someone advise me on the point in the article about how Time Machine is insufficient to backup one's entire computer?

My wife's Macbook Air uses Time Machine to backup, and I haven't done any other sort of backup with it. If her hard drive crashes, will she lose information, or is Time Machine reliable enough to restore her entire laptop? I just assumed it was good enough. If this isn't true, and if she loses any information, it's not Tim Cook who will need to deal with her wrath...

<comment><USER45> I've done several full system restores from Time Machine.

<comment><USER44> Thanks guys, I'm relieved to hear both of you have done it!

</comment></comment></comment><comment><USER46> > When you assume, you put plum paste on your ass

I don't get it...

Ume. I got it. I got. Hey, guys, I got it.

<http://en.wikipedia.org/wiki/Ume>

<comment><USER47> I don't think that word is pronounced the way the blogger thinks it is…

<http://www.merriam-webster.com/dictionary/ume>

</comment></comment><comment><USER48> The "Thank you Apple" title sounds like a gushing fanboi love letter. I almost didn't read the post (which is quite good, glad I did).

I just think the title should be a little more clear (like add a "not" at the end).

<comment><USER49> Rob Pike is a Canadian :)

</comment></comment><comment><USER50> I was spec'ing out a new macbook pro and saw that memory is now soldered in, and the SSD drives have proprietary interfaces. I am, how shall you say, displeased...

</comment><comment><USER51> I learned something today.

</comment><comment><USER52> redacted</comment>


ChromeSheep - FireSheep for Chrome (uses Node.js server for packet capture) - <AUTHOR> https://github.com/hmarr/chromesheep

<comment><AUTHOR> The result of an evening hack, so not very robust or feature-complete. Only has support for hijacking hacker news sessions so far.</comment>


US Military Aims to Start Using Laser Weapon That Produces Voices by 2021 - <AUTHOR> https://interestingengineering.com/us-military-aims-to-start-using-laser-weapon-that-produces-voices-by-2021 <comment> tek-cyb-org knew about this over 10 years ago playing halo with plasma weapons.</comment>


How to use the Python Imaging Library - <AUTHOR> http://www.pythonforbeginners.com/modules-in-python/how-to-use-the-python-imaging-library/

<comment><USER2> An article posted 7th Nov 2013 should not be recommending use of PIL (a dead project) over Pillow, imo. The only reference to Pillow in the article is a link at the bottom to the Pillow tutorial.

<comment><USER3> I'm a maintainer for pillow. Feel free to ask any questions.

(I'm not sure PIL is a dead project. It's just resting. Beautiful plumage through)

<comment><USER4> I know Django isn't end all, be all, but with them moving forward towards 1.8 where PIL will be completely depreciated, that's really the first nail in the coffin for PIL.

<comment><USER3> It's also filtering into the distro packaging -- I think it's in debian unstable, ubuntu as of raring, and fedora ~19.

</comment></comment></comment></comment><comment><USER5> When drawing something from scratch, I found Pycairo to be much more useful.

[http://cairographics.org/pycairo/](http://cairographics.org/pycairo/)

</comment><comment><USER6> This is missing step one: use Pillow instead of PIL

</comment><comment><USER7> Love PIL/Pillow, for just about the easiest image I/O there is.

I've been using it recently and needed a bit more industrial strength and speed than the library provides. PIL supports converting an image to/from a NUMPY array! (And the execution speed difference is definitely worth the effort...)

Now my template for a new PIL script looks like this (all error checking removed for simplicity):

from PIL import Image

import numpy as np

im = Image.open(args.input)

rgb8 = np.array(im)[...,:3]

rgb = rgb8.astype('float') / 256.

# ... do stuff to 'rgb' using np

rgb8 = np.clip(rgb * 256., 0, 255).astype('uint8')

im = Image.fromarray(rgb8)

im.save(args.output)

</comment><comment><USER8> People should consider checking out Wand as well. Really nice wrapper around ImageMagick. Very good pythonic interface.

</comment><comment><USER9> PIL is dead. How did this get 14+ points?

<comment><USER10> Because the actual content of the article is interesting, it's as applicable to Pillow as it is to PIL.

</comment></comment><comment><USER11> Unreadable in mobile safari. The text is jammed into one skinny column that's so tiny it can't even word wrap effectively. It breaks lines in the middle of words. How and why do people keep going out of their way to make websites unreadable on phones?

<comment><USER12> One hardly needs to go out of their way to make a page unreadable in one browser. Developing proper CSS to support cross-browser, mobile-friendly websites to this day still isn't common knowledge for all developers. And it's almost impossible for most people to test their site across different mobile platforms themselves.

For example, this website looks fine on my Windows phone. I'd have no idea his website had an issue if you hadn't mentioned it. If I had been particularly impressed by the way his site looked, I might have been tempted to borrow his CSS and propagate the problem without realizing the problem was there.

<comment><USER11> I wish people would simply not bother being mobile friendly if they can't do it right. I have no trouble reading desktop oriented sites on my phone. Maybe it's cumbersome, but at least I can zoom and pan. It's only when people dick around with fixed viewports and disabled zoom that I have issues.

</comment></comment></comment><comment><AUTHOR> Thanks for all the comments. I should obviously have used Pillow instead of PIL. This is the first time that I'm using a graphical library in Python. I hope to find the time to update the current post or write a new one that will address this.</comment>


Untitled Document Syndrome - <AUTHOR> http://daringfireball.net/2009/02/untitled_document_syndrome <comment><USER13> Most people don't understand hierarchical filesystems. I understand that and that's fine. As designers and programmers, we should be enabling those people to have control over and access to their stuff in a way that they can use.

But I do understand hierarchical filesystems, so why would I want to do things the same way as people that don't? I don't use notepad.exe just because vim is too confusing for most people, either.

I installed iTunes once and it took me a couple of confused minutes to figure out that I couldn't play a file in it. First you have to teach the app about all of the music that I might someday want to play, then you can finally choose one of those and play it. But I know where my music files are on the disk and I just want to play them. To use Gruber's analogy, I wanted to type 'print "Hello World"' and it wanted me to start defining includes.

In the same way, I store my information in text files on the disk. They're arranged in a way that makes sense to me. They're searchable, portable, and small. And it works great for me.

<comment><USER14> _I do understand hierarchical filesystems, so why would I want to do things the same way as people that don't?_

The filesystem isn't relevant to what either of you want to do - namely, start taking notes, and, not lose them if you forget to save them.

Sure, save them wherever you like however you like - but I bet you start with "I need to make a note of this phonenumber" and not "I need to create ~/data/contacts/business/suppliers/joans.computers" so I can put this phonenumber in it".

<comment><USER15> Interesting. I think your point is generally good but that phone numbers is an example against it. I tend to document stuff using the second approach, because I'm documenting for lookup. Phone numbers are a case in point - <USER2> always have it in front of me on a scrap of paper, but want to enter it into the appropriate page and place of our wiki where I or a colleague will be able to quickly recall it later. I'm creating it with the lookup in mind.

Whereas if I'm opening a document just to play around with ideas I won't be doing that, and most documents start that way. I think this is why Word has so far won the field in mainstream document production. Word is a superb tool for prototyping and terrible in almost every aspect of structuring data for its long-term use.

</comment></comment></comment><comment><USER16> Odd. I never knew this problem even existed. Practically everything I make starts with vi, and I never just type it without an argument.

I write untitled things on Etherpad (because it doesn't let you give things titles yet), but Etherpad backs up every keystroke.

<comment><USER17> What about before Etherpad? I'm curious to know.. :)

<comment><USER16> Before Etherpad, I solved the problems it solves by various expedients like publishing drafts on my private web server, putting stuff on wikis, and exchanging drafts by email.

Etherpad is a bigger deal than people realize yet. It's one of those things you don't understand till you try it. I myself didn't. I put off trying their first beta for weeks, and then within about 2 minutes of trying it I got it.

</comment></comment></comment><comment><USER18> One thing I've never understood is the confirmation dialogue you get when closing an application. Of course I want to save the document! The only time wouldn't want to save my changes is when I want to revert all the changes I made this session. I already have a perfectly good button for that the, undo button. (at least in a perfect world).

<comment><USER19> You don't ever run into that accidental situation where you opened a doc/makefile/source/etc that you just wanted to view but not change? That dialog is handy when you accidentally made a change but weren't aware of it. It doesn't happen a lot, but I know I'd have a number of more random characters in documents than I have now.

<comment><USER20> I think unlimited undo would solve this situation. If you're autosaving revisions, it's not a huge step to imagine allowing undo across application invocations.

</comment></comment></comment><comment><USER21> I just want my filesystem to be categorical instead of hierarchical. Maybe some use of metadata types would make it easier to avoid collisions too?

Example. My "The Battle of Evermore" mp3 could live in the following typed categories:

      "FileHash:blahblablahblah"
      "iNode: blahblahblah"
      "Title: The Battle of Evermore"
      "Artist:Led Zeppelin"
      "Album:Led Zeppelin IV"
      "Collection:Project: LotR RotK Music Video"
      "Playlist:Music: Swordfightin' Songs"

etc etc

Is that so wrong? If you use a rigorous enough metadata type system, you could program it too!

<comment><USER22> > I just want my filesystem to be categorical instead of hierarchical. Maybe > some use of metadata types would make it easier to avoid collisions too?

What's weird is that the very first file system the Mac used was very close to this. MFS didn't support true directories; folders were an illusion provided by the Finder. Be OS, I believe, was the closest to your ideal that was ever developed, but it was considered too alien and "late" for it to have ever gotten traction. Just like the automobile got saddled with the internal combustion engine and manual wheel-based control, personal computers got stuck with x86 and hierarchical file systems.

<comment><USER23> _personal computers got stuck with x86 and hierarchical file systems_

And UNIX. Can I have my Lisp machine back, please?

(OK, so I never had a Lisp machine. But I want one :P)

<comment><USER24> But with lexical scoping!

</comment></comment></comment></comment><comment><USER25> OneNote handles this really well. It automatically saves everything. Very handy when working on notes and ideas.

</comment><comment><USER26> i see this as a flaw in modern operating systems. the LifeStream OS concept dealt with this rather nicely, providing a document-centric, time-oriented file system, but also allowing for versatile meta-data to aid in classifying objects and navigating around.

<comment><USER27> Jef Raskin worked on an OS named Archy that also dealt with this problem:

<http://en.wikipedia.org/wiki/Archy#Persistence>

</comment></comment><comment><USER28> I'm surprised he didn't mention the iPhone Notes application as a great example of the principles he's talking about: besides autosave and getting rid of the filing friction it also eliminates the friction of naming.

For me a huge part of the hassle with saving documents is naming them. When I'm in note-jotting mode it's usually low level, so to have to step back and try to quickly come up with a title that covers everything I've _not yet written_ is frustrating because I'm not in an overview mindset and there's nothing yet to summarize. Add on to that the administrative work of filing, and saving text documents becomes something I put off for as long as possible.

I've tried Notational Velocity, but it has the same problem of forcing you to create a title separate from the content. (It also lacks creation dates, which are I find valuable for putting notes into context.)

</comment><comment><USER29> Abstracting away the filesystem works great if all the software you use does provide you a way to get to it anyway (like iTunes does) if you really want it. However a lot of software doesn't provide that.

For example, on my S60 phone, the file system is pretty much hidden from the user. You just save your notes\contacts\pdfs\mp3s and the programs know where to put them and how to retrieve them. But try saving a python script as a note and then trying to get Python to execute it on your phone. Oops, no way to find out where that damn file is saved.

</comment><comment><USER30> I would _love_ to solve this problem. I've commented before about the limitations of current file system management (e.g. top comment on [http://www.woobius.com/scribbles/posts/0007-document- control...](http://www.woobius.com/scribbles/posts/0007-document- control.html)), and I've worked out most of the UI and algorithmic structure for a replacement system.

Soon. Real soon now, I'll get sick enough of dealing with file "management" systems, and this will start to roll out.

</comment><comment><USER23> Would it make me a "smug Perl weenie" to point out that the Perl should be:

        say "Hello, world."

instead of

        print "Hello, world.\n"

(Larry++ for having the balls to call it "say" and not "println". It's shorter, _and_ it's a real word!)

<comment><USER31> There's more than one way to do it, then?

</comment></comment><comment><USER32> All major office apps have had 'auto-save' as a feature for oh I dunno .. a million years now.

<comment><USER33> That's not the main thrust of the article, it's about a class of apps like Yojimbo, iTunes and iPhoto that abstract away the underlying file system so that even the concept of saving data goes away.

</comment></comment><comment><USER34> Is there anything like Yojimbo but _simpler_? Some program for me to jot notes and clip things that doesn't reformat text or give me tons of filters? Yojimbo and Evernote are both too bulky for my tastes. Anybody have any recommendations?

<comment><USER35> If you're using a mac there a lot of note taking programs:

       - <USER3>
       - <USER4>
       - <USER5>
       - <USER6>
       - <USER7>
       - <USER8>
       - <USER9>
       - <USER10>
       - <USER11>
       - <USER12>

And that's a list from what I've been using for note taking: emacs org-mode. Though lately I've been a bit torn between using org-mode and something like Evernote, particularly due to its device synchronization. I would really like to hear other people's thoughts about this.

Oh, and if you don't like Yojimbo and Evernote, you might want to check out Voodoo Pad.

<comment><USER36> I like xPad. It's simple and free:

<http://getxpad.com/></comment></comment></comment>


Ask HN: Pay for Tumblr Backup Service? - <AUTHOR>

I woke up this morning and half of my Tumblr blog has disappeared. Honestly, given Tumblr's recent problems, I'm not surprised that this has happened. I've put blood, sweat, and tears into my blog; this is really disappointing.<p>My question: is there a Tumblr backup service that you use? Would you be willing to pay for a Tumblr or blog backup service?<p>-Heartbroken blogger <comment><USER2> Even more helpful would be import / export to wordpress.

</comment><comment><USER3> I probably wouldn't pay because there is a free backup tool (<http://www.tumblr.com/goodies>). Though for non-tech folk it could be cool to get automatically updates and restores if such a fatal error occurred.</comment>


Getting killed by police is a leading cause of death for young black U.S. men - <AUTHOR> https://www.latimes.com/science/story/2019-08-15/police-shootings-are-a-leading-cause-of-death-for-black-men <comment><USER2> The HN title doesn't match the article title which is less controversial.

Even with the article title it's click baity.

I'm 100% on board for dearming the American police force, if only for its racist undertones but this study shows a) black men are getting dreadful health care, mental health care & crime prevention but also b) American cops are killing lots of people they shouldn't.

We don't need Bad headlines yo point that put.

<comment><AUTHOR> I didn't create the HN title; it was autogenerated from the source.</comment></comment>


Machine learning and data are powering Monzo's fintech disruption - <AUTHOR> https://www.thedrum.com/news/2019/04/11/machine-learning-and-data-are-powering-monzos-fintech-disruption <comment><USER2> Monzo is not "an app".

It's a bank that can only be accessed through an app. Monzo is an actual bank that provides actual bank accounts.

I think it's important to call it what it is instead of using buzzwords like "app-only fintech startup scaling its's machine learning capabilities" (bingo!).</comment>


At what point should an intelligent machine be considered a person? - <AUTHOR> http://robohub.org/at-what-point-should-an-intelligent-machine-be-considered-a-person/ <comment><USER2> When it has self awareness

<comment><USER3> Young babies don't display any signs of self awareness.</comment></comment>


Is Bitcoin Mining profitable in 2017? - <AUTHOR> https://99bitcoins.com/bitcoin-mining-profitable-beginners-explanation/ <comment><USER2> tl;dr almost certainly not for you. Since there are economies of scale, mining naturally centralises. And what we see now is miners literally designing their own ASICs to compete.</comment>


Sumup in Berlin Is Hiring Senior Software Engineers (Golang) - <AUTHOR> https://sumup.com/careers/positions/4564408002/ <comment><USER2> HN is not a job board, please see the FAQ for relevant information regarding job posting</comment>


Peerlyst Brings the Power of Social Media to IT Decision Making - <AUTHOR> http://blog.peerlyst.com/category/press-releases/

<comment><USER2> This is something very productive. After so many years of googling on the web to find product's review on different sites, finally there is a company bringing all professionals on the same platform to help review and get advise on security products.

This is really helpful for IT Pros, Mobile Security and etc.

</comment><comment><USER3> It seems to me that initiatives like this has potential for the whole world right alongside OWASP, WEARETHECAVALRY and other organisations/movements who try to raise the bar</comment>


Search Your Cloud From Your Browser: Greplin (YC S10) Adds a Chrome Extension - <AUTHOR> http://techcrunch.com/2011/03/11/search-your-cloud-from-your-browser-greplin-adds-a-chrome-extension/

<comment><USER2> As the article mentions, Greplin (YCW10) is hiring across the board (front end, back end, ops, dev-ops, designers, etc). <https://www.greplin.com/jobs>

<comment><USER3> Thanks for the link - I hadn't taken the challenge yet, was fun!

</comment></comment><comment><USER4> This feels like giving copy of all your important data and then searching using third party tool because somehow my workflow/information is not ORGANIZED, if something is important I'll hunt it down where it BELONGS. Can someone please help me understand why it is not a problem?

</comment><comment><USER5> I depend on my GMail account for business and I am not enthusiastic about authorizing 3rd party access.

I think a better idea would be a local app that indexes our own material, keeping local search indexes and that shares nothing with 3rd parties.

</comment><comment><USER6> The only problem with this is that you have to delete the autocomplete before you can press tab or else it doesn't work. But excellent work, I love Greplin and I can't wait to see how it grows and evolves.

<comment><USER7> Try spacebar instead of tab.

<comment><USER6> Much better, I feel like the instructions should be changed to reflect this.

</comment></comment></comment><comment><USER8> Here's the extension: [https://chrome.google.com/extensions/detail/bjclhonkhgkidmlk...](https://chrome.google.com/extensions/detail/bjclhonkhgkidmlkghlkiffhoikhaajg?hl=en)</comment>


IPTV can be a lot more than just TV - <AUTHOR> http://flowr.media/flowr-academy/iptv-more-than-just-tv/ <comment><USER2> Marketing fluff for their own product that talks about "the new dimension" added to TV. Garbage.</comment>


Nuclear fusion milestone passed at US lab - <AUTHOR> http://www.bbc.co.uk/news/science-environment-24429621 <comment><USER2> It is an important milestone. But to have a commercially viable fusion reactor, you'll need a factor of 50-100 more energy out than in to make up for inefficiencies in electricity generation using this kind of scheme.

The real story here is that this facility allows the US to do nuclear weapons research without violating the nuclear test ban treaty. If the goal was to develop a commercially viable fusion reactor, the $3,500,000,000 spent so far could have been put into projects geared towards small scale fusion experiments investigating novel confinement schemes.

Like the one I was working on, [http://meetings.aps.org/Meeting/DPP07/Event/71002](http://meetings.aps.org/Meeting/DPP07/Event/71002) whose funding has since been cut and has been mothballed.

<comment><USER3> I wonder, what more do they need in nuclear weapons? Smaller size? Harder detection? Bigger contamination radius?

Somehow, I am sure, if people start a nuclear war, even the WWII's initial nuclear weaponry will be enough to destroy ourselves, knowing how many countries can now chime in with their own.

<comment><USER4> The US now has a notion of "tactical" nuclear weapons.

Some reading:

[http://www.fas.org/_docs/Non_Strategic_Nuclear_Weapons.pdf](http://www.fas.org/_docs/Non_Strategic_Nuclear_Weapons.pdf)

God help us all.

<comment><USER5> That's been around since 1953 (less than a decade after the first atomic detonation in '45). [1]

And we've maintained a limited number of low-yield warheads that would fall under that designation. [2] (as an example)

[1] [http://en.wikipedia.org/wiki/Nuclear_artillery](http://en.wikipedia.org/wiki/Nuclear_artillery)

[2] [http://en.wikipedia.org/wiki/B61_nuclear_bomb](http://en.wikipedia.org/wiki/B61_nuclear_bomb)

</comment></comment></comment></comment><comment><USER6> A good place to start if you want to understand the purported rationale for the NIF (stockpile stewardship), I suggest reading and understanding this light introduction to modern nuclear weapons. [http://en.wikipedia.org/wiki/Thermonuclear_weapon](http://en.wikipedia.org/wiki/Thermonuclear_weapon) (the rhodes books, Making of the Atomic Bomb is required background reading, as is Dark Sun, if you want to get into the backstore).

In particular: The NIH experiment recapitulates many of the design aspects of a thermonuclear weapon, but does so in a highly controlled lab environment.

I'm a biophysicist. I know a fair amount of engineering, although I'm not a weapons physicist. Nonetheless, after years of reading about the NIF and various fusion projects I've come to believe that there is little justification for their expenditure. In particular, we can do stockpile stewardship without this device, more cheaply, nor does NIF present an economically viable method to production of power at a large scale in even the most rosy predictions.

I still think the experimental design is cool, but I can't see this as a rational expenditure (HUGE opex and capex) compared to other investments we could be making.

Most likely scenario I see in 20 years is that china will be mass- manufacturing small, safe fission reactors and making a mint selling them to the rest of the world. That's got far less reqiurement for massive capex and opex. It's just that the western nations decided to go stupid about fission because OH GOD NUCLEAR MUTATIONS and stop investing in building more reliable, safer, and smaller plants.

<comment><USER7> The NIF is probably more useful for coming up with new fusion bomb designs than for stockpile stewardship, as you say, but what makes you say hot fusion can never be economically viable? The sun is proof that nature can do this on a grand scale! It may be a long ways off, but "a long ways" becomes "never" without experimental work like the NIF. Yes, the U.S. is probably doing this primarily to create new weapons just as the space race was really about developing ICBM's. However, the fundamental science being done has huge long- term potential. It's a sad, but true fact that, sometimes, scientists have to use the megalomania of states to fuel research that has the potential to benefit all of humanity.

Fission power is a separate matter. The single most important thing that most people still do not understand is that power grids have almost zero capacity for storing energy. That means most alternative energy sources, such as wind or solar, can never exceed a certain percentage of the grid's production capacity or it will become unstable. On-demand energy generation is still needed, and there's absolutely no reason to fear nuclear power while we're still using coal power, which is far more deadly in every sense! It's not just the West that has this fear either. Look at Japan's recent nuclear shut- down[1] (from 30% of their grid to 0%, replaced with fossil fuels), and tell me that isn't going to influence China!

[1][http://www.reuters.com/article/2013/09/14/us-japan- nuclear-s...](http://www.reuters.com/article/2013/09/14/us-japan-nuclear- shutdowns-idUSBRE98D0DL20130914)

<comment><USER8> Coal power is more deadly than fission power?

When has coal power ever created the sort of crisis that occurred in Fukushima?

Because of fission reactors, the safety of entire regions of the world is dependent on a consistent power supply and lack of human error, something that clearly we can not rely on. In the event of a cosmic emp or major meteor strike, these power plants are at risk.

<comment><USER9> Coal power creates that kind of crisis every day, so we don't bother calling it a crisis anymore.

 _A total of 240,000 years of life were said to be lost in Europe in 2010 with 480,000 work days a year and 22,600 "life years" lost in Britain, the fifth most coal-polluted country._

[http://www.theguardian.com/environment/2013/jun/12/european-...](http://www.theguardian.com/environment/2013/jun/12/european- coal-pollution-premature-deaths)

<comment><USER8> "commissioned by Greenpeace International" who I'm sure would back the position that nuclear fission plants are safer than coal.

Of course, nuclear power plants are safe short term. Their threat is catastrophe, which given time, is inevitable.

<comment><USER10> Even _with_ a catastrophe every 50 to 100 years nuclear kills _far far_ less people than coal.

<comment><USER8> This is not really calculable, nor is the number of people killed by coal calculable in any reasonable manner. However the impact of nuclear catastrophe is _far far_ more insidious and lasting, particularly when caused by a global calamity that causes meltdown in many plants.

<comment><USER10> > This is not really calculable, nor is the number of people killed by coal > calculable in any reasonable manner.

Of course it is. 161 people are killed for each THw of coal energy. And 0.04 people for each THw of nuclear power and this INCLUDES Chernobyl!

[http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy- so...](http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html)

[http://www-958.ibm.com/software/data/cognos/manyeyes/dataset...](http://www-958.ibm.com/software/data/cognos/manyeyes/datasets/1fa41e6c4fb211e0b29f000255111976/versions/1)

> However the impact of nuclear catastrophe is far far more insidious and > lasting

Clearly you've never seen [https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly...](https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly_ash_slurry_spill) the radiation and heavy metals released from that can never be cleaned (just diluted).

> particularly when caused by a global calamity that causes meltdown in many > plants.

A what?? And how do you manage that? If you have unreasonable fears then there is no point in talking to you. Reason will not remove an unreasonable fear.

<comment><USER8> I suppose fear of a 9+ earthquake followed by a massive tsunami off the coast of Fukushima was considered unreasonable.

We are on a blob of rock hurtling through an unknown cosmos. Calamities are very possible. It is deeply irresponible to create projects that will make large parts of the earth uninhabitable should the power grid fail for a long period or human stewardship go on hiatus. Meteor strikes, emps, plagues, terrorist attacks, economic collapse,and other disasters are well within the realm of possibility

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER11> This is awesome news - I visited the NIF a few months ago and they seemed a little downtrodden when asked about results.

I bet they're all cocky now!

They also told us that the lasers they use, if built with modern tech today, would actually only be the size of a 40' cargo container (as opposed to like 100K sq-ft building), and cost like 1000x less. Pretty epic...

If we invested in fusion power like we did water power less than a century ago, I can only imagine the possibilities...

<comment><USER12> This is so cool. I almost can't believe that such incremental tech development would be applicable to fusion research. But there you have it. Now we just have to throw a few more billions at the problem. If the costs really have come down this dramatically, it is very promising indeed.

</comment></comment><comment><USER13> I think Nuclear Fusion is the single most exciting up-and-coming technology. I can't believe we're not throwing a hundred billion dollars at it.

Make fusion, not war.

<comment><USER14> Right, but what's its viral coefficient? How can we get it as a mobile app?

<comment><USER15> I'm torn. Should we focus on gamifying it or making it web-scale?

<comment><USER16> Do you want to disrupt the power grid? Fusion.ly is hiring!

<comment><USER17> >F.co

</comment></comment></comment></comment></comment><comment><USER18> Producing net-energy is a different story than collecting net-energy. NIF just blows up a canister with a pellet and takes forever to reload a shot. On the other hand, an at-least-as-promising technology like Dense Plasma Focus ([http://en.wikipedia.org/wiki/Dense_plasma_focus](http://en.wikipedia.org/wiki/Dense_plasma_focus)) is still receiving minuscule funding. I'm hoping to be able to meaningfully support DPF and other fusion technologies soon. DPF has my attention so far because of its scaling characteristics.

<comment><USER19> What does producing energy mean if not collecting it? The conservation of Energy tells us that we are not actually producing any energy, rather we are converting energy from the mass of the reactants (hopefully into electricity). If you consider the energy converted from mass to be produced, then it is impossible to do nuclear fusion without producing net-energy (as long as you stay on this side of lead).

<comment><USER20> Producing does not imply the ability to do useful work (power steam turbines).

</comment></comment></comment><comment><USER21> There was not an overall net gain.

Direct from the source [http://1.usa.gov/1e4Na9Q](http://1.usa.gov/1e4Na9Q).

8 kJ out from 1.7 MJ (1700 kJ) in. At the end of the month they were able to get 14 kJ. I believe they are referring to the energy released within the hohlraum.

Also, if you are interested there are privately funded companies doing this, General Fusion ([http://www.generalfusion.com/](http://www.generalfusion.com/)) and TriAlpha Energy (secretive and funded by the Russian govt., but in California). The VC fund I work for has invested in GF and obviously we think there is promise :)

</comment><comment><USER22> Ah, okay, cool!

I remember this being announced a while back, but I didn't understand why it was significant if the energy in was less than the energy out. This article helps to clear it up.

The missing piece was that I didn't understand how this reactor works. I thought they just blasted a lot of lasers directly at the hydrogen isotopes. Instead, it seems like that use the lasers to shoot something else, which then creates a lot of x-rays which actually start the reaction.

The significant thing here is that the energy produced is greater than the amount of energy coming in from the X-rays, but not the lasers which power those X-rays.

Is that correct? (Not surprisingly, I'm not a physicist!)

<comment><USER23> Lasers gets fired at the inner surface of a cylinder (called a hohlraum). The laser heat the surface of the hohlraum which then emits x-rays. The x-rays then deposit energy on the surface of a spherical capsule (this is the "energy absorbed" number).

You start with ~2,000 kJ of laser energy, but some of that gets "backscattered" and never makes it into the hohlraum. Other energy is spent heating the walls of the cylinder. Additionally, some of the x-rays leak out of the hohlraum and do not drive the capsule implosion. After all these losses are taken into account, only about 15 kJ is absorbed in the capsule.

</comment></comment><comment><USER24> I keep seeing this same story pop up (from what I presume is the same September event).

Is there anything new this round? Perhaps some new results from post- experiment data analysis? The article isn't really clear on this point.

</comment><comment><USER25> Not really well-informed enough to comment on details, but it's fantastic to see the field is still moving, even if slowly. Proud that we are still funding this kind of research.

<comment><USER26> Sorry to piss on your parade, but..

"Soon after, the $3.5bn facility shifted focus, cutting the amount of time spent on fusion versus nuclear weapons research - which was part of the lab's original mission."

Admittedly that is phrased in an odd way...

<comment><USER25> Not thrilled about that part, but the "Soon after" refers to events past, not the success this article is about.

 _However, the latest experiments..._

So, at least the fusion research is still funded and still moving.

<comment><USER27> This bit of the fusion research is mostly aimed at making small-scale experiments on weaponised nuclear fusion without having to set off nuclear bombs every other day. As a long-term energy source, it is assumed to be rather unusable.

</comment></comment></comment></comment><comment><USER28> tl;dr - Another article about the US nuclear weapons research facility at Lawrence Livermore, AKA NIF, and its sideshow 57th priority.

On a related note. It's been really sad to see the US slowly lose its edge in plasma based fusion tech, specifically tokamaks, which seem to be the only credible long-term method of sustaining a fusion reaction for power-plant purposes.

<comment><USER23> Just a couple quibbles from a former NIF scientist.

NIF is much higher on the priority list than that. LLNL is already in the doghouse due to NIF failing to ignite on schedule. As goes the 5 giga-buck NIF, so goes LLNL (and the management knows it).

Technologically, I'd put inertial and magnetic fusion about the same place. Even if the physics works, neither has a chamber first wall material that can stand up to the huge neutron loads that a power plant will create. Economically, both are hosed. Fusion wants to be big. Most reactor designs are for >1,000 MW. Electric companies are mostly interested in plants in the 50-400 MW range.

<comment><USER28> Don't get me wrong I think that LLNL and the NIF are doing great work. I just think the work is more weapons based and less energy than we are all lead to believe in the press. and I meant that the Fusion Reactor business is a low priority compared to testing the nuclear stockpile, etc., not NIF in general.

The chamber first wall material keeps me up at night. I think money spent in that area would be really well spent and have many many uses, both in places where you need neutron shielding, and to a lesser extent, protection from heat. When I think of really big, fun, 1960s style energy projects, the only other 'credible' one seems to be laser pro-pulsed power-satellties. Now there is where we might take a lot of the laser tech from the NIF!

<comment><USER23> This is true. The reactor work is very low priority, and the LLNL's reactor project "LIFE" has more fairy dust than I prefer. However, fusion and other NIF experiments are important.

</comment></comment></comment></comment><comment><USER29> On the article itself: why did it take 6 paragraphs of text to finally mention what the milestone was? I hate this style of article writing, and it's usually a good bullshit-signal for any story. That's a shame, because it looks like this is the Real Thing (in a small way).

</comment><comment><USER30> Not much of a physicist myself but I am wondering if the technology developed for nuclear fusion would have any use in progressing other fields

<comment><USER23> I can think of two off the top of my head. Low temperature plasma processing (used in semiconductor fab) got it start as the-mess-created-when-a-plasma- confinement-experiment-fails. Adaptive optics were developed for high intensity lasers and are now used in telescopes.

</comment></comment><comment><USER31> Great, but I don't see how these extremely expensive nuclear fusion projects will ever beat price/kW of coal without heavy subsidies. My bet is that dense plasma focus is the future of cheap, clean power. Only time will tell though.

[http://en.wikipedia.org/wiki/Dense_plasma_focus](http://en.wikipedia.org/wiki/Dense_plasma_focus)

<comment><USER32> I would imagine that the price/kW of coal will become easier to beat as we run out of it.

<comment><USER31> Pick your favorite energy technology (oil, wind, solar), it still applies.

<comment><USER33> It's quite a bit harder to run out of wind and solar.

<comment><USER31> Yeah. My comment has nothing to do with finite or infinite amount of any energy technology but rather that my original comment applies to fusion competing with the price of any existing energy technology such as coal, oil, wind, solar, etc.

</comment></comment></comment></comment></comment><comment><USER34> "the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel" means it is at least 4 orders of magnitude away from being useful.

Since we still depends on nuclear power for decades to come, it is much cost effective to invest safer and cleaner nuclear fission reactors. The kind of fast reactor that can burn down nuclear waste so we don't need to build nuclear waste storage system, which nobody knows how to build anyway. That would give us power supply for several centuries (along with renewable energy). Too many countries wasted too much money on fusion reactors for decades, while we are still running nuclear reactors designed/built more than 30 years ago. Just wrong priority order.

</comment><comment><USER35> What would be the impact of a 'fusion economy', assuming realistic evolution of the technology for the purposes of commercialisation? (i.e. I'm assuming "Mr Fusion" powerplants on top of one's DeLorean aren't ever going to be practically feasible).

What would such a world look like? Does it promote world peace; through greater energy security for nations, would less reliance on fossil fuels for baseload electricity generation have a significant impact on price of air travel/sea cargo?

<comment><USER36> Fusion changes everything. Cheaper electricity makes transporting materials basically free. And projects like desalination become possible = no one remotely close to an ocean ever lacks clean drinking water again.

<comment><USER37> Or irrigation water, for that matter.

</comment></comment></comment><comment><USER38> > the amount of energy released through the fusion reaction exceeded the > amount of energy being absorbed by the fuel

So what? What if the fueld didn't absorb anything? What do they mean by "absorb", anyway? This article is lacking in details, peer-reviewed literature, or even the names of scientists willing to stake their reputation on this claim.

The BBC should know better.

</comment><comment><USER39> What is the opinion on Lockheed Martin's Skunkworks High beta fusion reactor? [http://en.wikipedia.org/wiki/High_beta_fusion_reactor](http://en.wikipedia.org/wiki/High_beta_fusion_reactor)

How does this stack up against the more conventionally theorised techniques?

</comment><comment><USER40> If reliable fusion technology were developed, would the government share it with the public or would it be kept hidden away?

Sadly I'm not joking. I think there's a 50-50 chance that any cool science that gets development by the U.S. government just becomes a classified DoD missile project.

<comment><USER41> The development of fission technology seems like a fine case to consider. I doubt we are more paranoid and militaristic now than we were during the height of the cold war. _Maybe_ we are, but I really don't see it.

</comment></comment><comment><USER42> Is it plausible this lab is trying to figure out how to make nuclear explosions without the radiation?

Because just imagine how terrifying the world would become from a superpower that didn't have to fear the radiation aftermath.

Fusion research seems like just a complete cover up.

</comment><comment><USER43> Glad to hear that this is continuing at LLNL despite the shutdown. Too bad no politician is going to use this as an example of why gov't investment is not a bad thing.

<comment><USER44> Probably because "The real story here is that this facility allows the US to do nuclear weapons research without violating the nuclear test ban treaty." \-- Another HNer from this field.

</comment></comment><comment><USER45> What ever happened to the polywell reactor design?

<comment><USER46> The University of Sydney have continued research of polywell reactors. I'm not terribly across their progress but I try to read papers whenever they're released though I haven't read any of their 2013 papers. It seems the last few years (2010-2012 at least) have focused around minimising point- and line-cusp losses.

More reading here: [https://en.wikipedia.org/wiki/Polywell#University_of_Sydney](https://en.wikipedia.org/wiki/Polywell#University_of_Sydney)

</comment></comment><comment><USER47> I can imagine everyone driving around in Tesla cars powered by Nuclear fusion in the not too distant future.

</comment><comment><USER48> It looks cold in that lab. Cold fusion?

</comment><comment><USER38> What milestone? Be specific.

</comment><comment><USER49> This is wonderful news, go NIF !

</comment><comment><USER50> Wow, I remember seeing this project start up a few years ago, about how they wanted to make a "sun" on Earth. It seems it only took them 5 years to achieve this:

[http://www.telegraph.co.uk/science/science- news/3981697/Scie...](http://www.telegraph.co.uk/science/science- news/3981697/Scientists-plan-to-ignite-tiny-man-made-star.html)

In a way, it reminds of Spiderman, too, but let's hope things don't go as badly as in the movie, once we start to make that "sun" big enough to provide a ton of energy.

<comment><USER38> This is a trite and meaingless comment.

Spiderman? Really?</comment></comment>


Why being at the top of Hacker News doesn't mean as much as I'd hoped - <AUTHOR> https://urbanverticalproject.wordpress.com/2015/08/21/why-being-at-the-top-of-hacker-news-doesnt-mean-as-much-as-id-hoped/

<comment><USER2> I've had blog posts make it to the top page of HN before, and likewise haven't really gotten much in the way of "conversions" from it. But that's OK... our blog[1] is a default Blogger template and there isn't much in the way of a "call to action" associated with most of our blog posts. In fact, now that I think about it, I don't think there's even a link on the entire blog, to sign up for our mailing list.

And while I should probably correct both of those deficiencies, I'm not _too_ worried about it. Why? Because the goal of our blog posts isn't necessarily to get people signed up for a mailing list or anything. It's mainly just about having people see the name "Fogbeam". It's all towards trying to establish what marketers call TOMA - Top Of Mind Awareness[2]. We just want people to keep hearing our name over and over and over and over, until eventually it sinks in. One day, I want to be at a place where if somebody asks a friend "Hey, do you know anybody who makes a cool Enterprise Social Network product we could use?", that friend will go "Hey, there's this company named Fogbeam Labs..."

That said, it wouldn't _hurt_ to try and get more engagement out of the blog posts. We do end a lot of them with a call to follow us on Twitter at least, but it really wouldn't hurt to push the mailing list more. It goes to the whole "permission marketing"[3] idea.

[1]: [http://fogbeam.blogspot.com](http://fogbeam.blogspot.com)

[2]: [https://en.wikipedia.org/wiki/Top-of- mind_awareness](https://en.wikipedia.org/wiki/Top-of-mind_awareness)

[3]: [http://sethgodin.typepad.com/seths_blog/2008/01/permission-m...](http://sethgodin.typepad.com/seths_blog/2008/01/permission- mark.html)

<comment><USER3> HN is more of a 'show and tell' rather than a platform for repeat-marketing. Every time someone reveals numbers behind their front paging it's awful as a growth mechanism, if the blog posts aren't even selling your company/product then it's even worse because that's another cliff in the conversion funnel from visitor to anything-of-value. Another startup recently revealed they got just 44 trial registrations from _three_ distinct front page stories [1] and over 9000 visitors.

Another example that comes to mind is yesterday's marketing blog post by GrooveHQ [2]. It was their second front page post _in nine months and 50+ attempts_ , and it wasn't even about their company or product. Instead it was about a different company whose content marketing for their ideal visitors had ironically grown their blog to 250,000 visitors a month. I wouldn't be too quick to consider optimizing for HN harmless.

To me it all reeks of @sama's "fake work" post from yesterday [3], right down to the justifications founders come up with - you're not going to achieve "TOMA" for enterprise social network software from a briefly popular blog post about something silly and unrelated Oracle said. You already achieved everything you will from it - a brief bump in your page views.

[1] [http://blog.yesgraph.com/yesgraph-tc-ph-hn-omg- bbq/](http://blog.yesgraph.com/yesgraph-tc-ph-hn-omg-bbq/)

[2] [https://www.groovehq.com/blog/zapier-interview-with-wade- fos...](https://www.groovehq.com/blog/zapier-interview-with-wade-foster)

[3] [http://blog.samaltman.com/the-post-yc- slump](http://blog.samaltman.com/the-post-yc-slump)

<comment><USER2> _To me it all reeks of @sama 's "fake work" post from yesterday [3]_

Blogging in general, or submitting to HN? If you mean the former, I strongly disagree. Blogging is, IMO, a key way of attracting attention and getting our message out. As for submitting to HN... well, once I have a blog post published, it takes 30 seconds to submit it here. Why not do it, if it's reasonably on-topic?

 _you 're not going to achieve "TOMA" for enterprise social network software from a briefly popular blog post about something silly and unrelated Oracle said._

Not by itself, no. Of course not. It's just one more thing to get people reading our blog. And that most recent entry was not just an attempt to draw hits for the sake of hits... since everything we do is OSS, we actively look for opportunities to promote the use of OSS, especially in favor of proprietary plays like Oracle. And a blog post pays continuing returns over time due to hits from search.

So anyway, I agree that HN in and of itself isn't necessarily a great tool for driving specific actions. But I will argue that submitting an article (which would have been written whether or not there was a HN) here is just part of a broader overall strategy for building awareness / gaining attention. A _small_ part, granted. :-)

 _I wouldn 't be too quick to consider optimizing for HN harmless._

Oh, absolutely. And I can't speak for anyone else, but we don't "optimize for HN". We write about the stuff we feel is important or needs to be said, and (usually) submit the link to HN (unless it's completely off-topic or irrelevant).

<comment><USER3>
        Blogging in general, or submitting to HN?

I mean targeting HN with an ongoing effort to reach the front page again and again, doubling down on relatively easy traffic with a few customers vs the much harder challenge of finding a good customer acquisition channel.

<comment><USER2> Yeah, I'd agree with that.

</comment></comment></comment></comment></comment><comment><USER4> I think that many of the comments in HN highlight the economical problems of vertical farming. So a typical HN reader will be more skeptical than a reader from a site with less technical discussion.

Discussion: [https://news.ycombinator.com/item?id=10092184](https://news.ycombinator.com/item?id=10092184) (78 points, 1 day ago, 121 comments)

Partial transcript of the first two comments:

> _Vertical farming is an energy nightmare. It requires at least 1000x more > energy than conventional agriculture because you have to provide > supplemental light for the plants to grow indoors. [...]_

> _What 's making this transition difficult is the economic viability. It only > makes sense in densely populated areas but those areas also have ridiculous > property values and higher utility costs. That makes it increasingly > difficult for these farms because the margins in farming aren't that great. > [...]_

<comment><AUTHOR> That's a really good distinction and one that I hadn't realized until now.

</comment></comment><comment><USER5> First, reading an article doesn't mean I'm super interested in the topic. It could just be that I was curious about the title and didn't need to know more than what was in the article.

Second, email is broken (thank you spammers). I don't subscribe to mailing lists because I'm not sure you're not going to give (voluntarily or not) my email address to third parties and most of the time it just clutters my inbox. I probably go on my spam account twice a year. One year later I will be wondering why I receive these emails about vertical farming and why aren't they trying to sell me viagra instead ;-)

So yeah page views just means you managed to get some people to click on a link, that's it.</comment>


Sticker shock: Why are glasses so expensive? - <AUTHOR> http://www.cbsnews.com/8301-18560_162-57527151/sticker-shock-why-are-glasses-so-expensive/?tag=contentMain;cbsCarousel

<comment><USER2> Just two weeks ago while fishing with friends we were wondering why all the brand name sunglasses had become so expensive and now I know why. I break so many I just buy the cheap Chinese knock offs now.

</comment><comment><AUTHOR> Not really tech news, but I thought the portions on price setting and the illusion of choice (and consumer demand for it) were relevant to HN.</comment>


Silicon Valley is Running out of Juice in 2018 - <AUTHOR> https://medium.com/futuresin/silicon-valley-is-running-out-of-juice-in-2018-978d0626231c <comment><USER2> We regret to inform you that we have decided not to proceed with your application for the position of Junior Online Troublemaker.

The writing sample you supplied is simply not up to the standards of rhetoric and general wordsmithing we expect of our junior troublemakers here at Middle Kingdom Troll Farm and Heavy Industries.

We wish you luck in your future endeavors.

<comment><USER3> Amazing the power of mainstream media. How quickly the villain changes from China to Russia, and now back to China.

<comment><USER2> Well, the author does go out of his way to say how the Chinese will own future of this industry, so if he's shilling for anyone, it's them.

</comment></comment></comment><comment><USER4> Every argument presented in this article is a straw man, the writing is pretty bad, and then he says SoftBank vision fund is positioned to grow because of ridesharing, AI blah blah - as if American capital isn't hugely invested in those fields.

<comment><USER5> I agree. This article is a case for an alt-economy more than giving evidence of the decline of Silicon Valley.

</comment></comment><comment><USER6> In which the author restates his title thesis in every paragraph, without ever mentioning supporting evidence.

<comment><USER7> It's proof by assertion. Just repeat the same thing over and over, eventually it will be true.

It's a real thing: [https://en.wikipedia.org/wiki/Proof_by_assertion](https://en.wikipedia.org/wiki/Proof_by_assertion)

<comment><USER2> Absolutely. No doubt about it. If you want something to become true, just repeat it over and over.

</comment></comment></comment><comment><USER8> A lot of Anti-American statements with no supporting evidence. The scant examples it gives for China's rise are the facial recognition algorithms China uses to subdue and control its population. As if that's somehow better than what Facebook and Google do. The entire article is hollow garbage.

<comment><USER9> What's really scary, is that facial recognition articles it links to describing the dystopian future that awaits China: the "ubiquitous surveillance network". Video cameras everywhere watching every move you make and reporting it to the social credit system.

</comment></comment><comment><USER10> "lol" \- San Franciscan</comment>


Plain english explanation of Big O - <AUTHOR> http://stackoverflow.com/questions/487258/plain-english-explanation-of-big-o/487278#answer-487278

<comment><USER2> That's a very clear and accessible explanation of what big O complexity is all about.

 _But_ (and that's a pretty big but), 'Big O' is not all there is, and once you've picked your algorithm based on the one that has the best expected runtime based on 'Big O', you _really_ have to try to make sure that:

      - your algorithm is executed with the lowest possible frequency

      - you concentrate on those pesky n's that you eliminated during analysis to
        make sure that you don't end up wasting all your CPU time on some
        little detail somewhere

      - you take in to account the effects of your code on caches and virtual memory

      - you profile your code afterwards to make sure that all your assumptions regarding
        the above are correct

It is very easy to pick the 'right' algorithm and still get crappy runtime if you skip those steps.

<comment><USER3> Big O only says something about n = Infinite. But n is never infinite in computer programs.

Big O is a tool for making estimates, and like all other (such) tools, you have to know its limitations to use it properly.

<comment><USER4> "Big O only says something about n = Infinite."

Err, no it doesn't. Big O is a tool for saying how quickly an algorithm runs based on the size of n, and it's usually used to measure real things, like what will happen when the filesystem has to handle 100,000 files, then 1,000,000, etc.

<comment><USER3> Nope. You ignore that the constant factor is removed (i.e. all factors but the one that is dominant for n going to infinite).

More precisly, it tells how the relative speed difference between 2 algorithms change when n goes to toward infinity. An O(n) will win over O(n^2), but the latter case might have a huge constant factor that makes it slower than the former for e.g. n <= million.

And very often, n is smaller than a million.

<comment><USER5> This is true for O(n) but not for o(n). f(n) is the class of O(g(n)) of g(n) if g(n) dominates f(n) for sufficiently large n. o(g(n)) strictly dominates f(n), though, no matter how small n is.

Big O notation, or Landau notation, is not just O(g(n)). It's also o(), Ω(), ω() and Θ(). It's understood, though, that n is considered to usually be rather large - another name for this notation is, after all, "asymptotic notation." In any case that you're really worried about speed, you should probably be calculating the speed of your algorithm directly rather than using mere asymptotic generalizations.

Aside: I can't think of any algorithms with huge constants like you described; in theory, you're correct, but in practice, the asymptotic generalizations apply for n <= 1000 or even often 100.

</comment></comment></comment></comment></comment><comment><USER6> Interestingly the top rated answer was given by the gentleman who got turned down by Google

<http://news.ycombinator.com/item?id=1520323>

<comment><USER7> I read his blog post (the entire one, which is unusual for me) and he writes, early on, that Google discovered him via his prolific presence on Stack Overflow.

</comment></comment><comment><USER8> Knuth's take: [http://micromath.wordpress.com/2008/04/14/donald-knuth- calcu...](http://micromath.wordpress.com/2008/04/14/donald-knuth-calculus-via- o-notation/)

</comment><comment><USER9> Really good and simple explanation. Elegant examples to illustrate his points as well.

</comment><comment><USER10> Understand the effect of the constant factor hidden within the Big O. Often a O(n) algorithm is faster than a O(1) algorithm, because n is too small. E.g. arrays vs hashmaps.

Make sure what n is in each case. For example a graph algorithm with O(n^2) and n being the number of nodes may actually be O(n) for n being the graph size (number of edges).

</comment><comment><USER11> Apparently computational complexity is no longer the first thing that comes to mind when I read "Big O".

</comment><comment><USER12> It starts with: "The simplest explanation" - and it goes on and on for 5 pages.

<comment><USER13> Simple is not short. A very short explanation could be given in formal mathematics but it would not be simple.

</comment></comment><comment><USER14> A friend of mine at University said the only true 'Big O' is Roy Orbison.

</comment><comment><USER15> That anime was _really_ confusing. I'm not sure I could come up with a simple plain English explanation.

Was it a dream? A computer simulation? An alternate reality? I mean, really, wtf?</comment>


Where do baby names come from? - <AUTHOR> http://www.slate.com/id/2116505/

<comment><USER2> How is babby nammed?</comment>


POVERTY: If Marc Andreessen likes this solution..you probably will too - <AUTHOR> http://lessthunk.com/2015/03/25/poverty-if-marc-andreessen-like-this-solution-you-probably-will-too/

<comment><USER2> poverty is a mega trend that will cause revolutions if not fixed;</comment>