Git – the simple guide - <AUTHOR> http://rogerdudler.github.io/git-guide/ <comment><USER2> Luckily there's also the git manpage generator for helpful documentation:

[https://git-man-page-generator.lokaltog.net/](https://git-man-page- generator.lokaltog.net/)

(to be clear, this will randomly generate a nonsense fake git man page, but it's hard to distinguish from the real documentation)

<comment><USER3> That's great, that should be shown to all "how can you dare ask for docs when you have man pages". Although the point of RTFM is very legitimate, man pages are often well complimented by tutorials, cheatsheets and everything that can help someone be productive.

</comment></comment><comment><USER4> In all honesty, the more guides that are out there, the better. For most people, myself included, learning how to use git is a very daunting task.

</comment><comment><USER5> _master_ and _origin_ are mere conventions, you can call your upstream remote and upstream branch whatever you want, although it's good to respect convetions. I make this comment because the _guide_ does not make note of this fact.

</comment><comment><USER6> It should mention git pull --rebase. Otherwise it's not very useful since you'll end up clobbering stuff that collaborators have done.

</comment><comment><USER7> (2012)

<comment><USER8> Thank you. It looked familiar. I thought maybe it had newsworthy updates.

</comment></comment><comment><USER9> old but good</comment>


Through a Glass Darkly: the world of mathematicians - <AUTHOR> http://arxiv.org/PS_cache/arxiv/pdf/0807/0807.2656v1.pdf

<comment><USER2> _It is by logic we prove, it is by intuition that we invent. — Henri Poincare_

It's very encouraging to hear that proving theorems is difficult for real mathematicians too.

<comment><USER3> Reading mathematics is always a huge ruse. Every part of it is designed to make years of sweat and blood look like a 15-second insight of vast subtlety.

By design, of course.

</comment></comment><comment><USER4> Summary: A private college math head considers the existential, professional and communication problems peculiar to mathematicians.

</comment><comment><USER3> "There are probably rather fewer mathematicians who conceive of themselves as artistic mathematicians."

I know there are a number of people on HN running around who are accomplished mathematicians. I'm curious if they know of any mathematicians around who think of themselves as "artistic mathematicians" and focus on communication with laypeople of the deeper parts of math.

Who around tries to _sell_ math?

<comment><USER5> I try to sell math but in a more literal sense - as something my software runs on. And yes, I have to "focus on communication with laypeople of the deeper parts of math" (nothing artistic though). Very different from when I did pure math. And it is tough. But not as tough as teaching calculus to undergraduates...</comment></comment>


Show HN: Monitor in a Box – Instantly usable, open source monitoring - <AUTHOR> https://solutions.stacktile.io/ <comment><USER2> I would love to read more about your product/service/idea.

But I can't.

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

Being visually impaired just makes things worse. Your site doesn't work with FireFox 'Reader View', and that forces me to 'Toggle CSS' off which causes the icons and site-design to be FUBAR.

You might have the best damn product in the world, but if I can't read about it on your own pages then it's no good to me.

I only found out that you use Ansible from the comments on here from another poster. I really want to know about this now as I have migrated our entire datacenter to Ansible, and I really love it.

<comment><USER3> Is reader view an officially supported standard? I must say that if you can't read the #586772 on white, that's a pretty severe handicap that I imagine would require a screenreader.

Let me postscript that I have sympathy for not having full ability to read on the internet, and I'm sure the world would be easier for many if screenreaders and high contrast were universal, but I also wonder whether and by how much design must suffer to accomodate all users.

<comment><USER4> >I must say that if you can't read the #586772 on white, that's a pretty severe handicap

well, i have pretty much technically perfect (just very easily tired after almost 30 years looking into the screen) vision and while i can read it, i'd prefer to have it in higher contrast as i just physically feel how my eyes have to work harder for the glorious make benefit of design.

After spending some time some years ago on accessibility related work, it became clear to me that while obviously the accessibility is the key for handicapped users, the thought-through accessibility (vs. just "get a screenreader") on a project frequently results in the improved design that is better (like in particular cleaner and simpler in appearance and interaction flow) for the regular non-handicapped users too.

</comment></comment></comment><comment><USER5> I'm impressed with this project's messaging and support/feature pricing structure. I think trying to find more sustainable models for funding open- source software is interesting, and I don't recall seeing this exact approach used before (i.e. free version w/o LE or Graphana support). It'd be amazing if a percentage of each support contract gets donated back to upstream projects like icinga2, Graphana, and LE.

</comment><comment><USER6> Very interesting. As one of the sufferers who struggled many times with setting up icinga2 with distributed (and SSL-Encrypted) monitoring, this automation takes a way a lot of the hassle. I think it is one step in the right direction. Reminds me with: [https://mailinabox.email/](https://mailinabox.email/)

<comment><USER7> This is very interesting, thank you for sharing!

</comment></comment><comment><USER8> Wondering what the free version uses if it doesn't include graphite for dashboarding. It also feels way more invasive to have to install Ansible on all of my servers instead of just statsd plus a config file to point it at a host. (Edit: it's not required.)

Nice to have a supported, pro-grade monitoring product that isn't priced per server, finally.

<comment><AUTHOR> Hi zbjornson, regarding your question about "Wondering what the free version uses if it doesn't include graphite for dashboarding": the answer is that free version just includes the icingaweb dashboards and not those implemented with grafana.

Also I'd like to clarify a possible misunderstanding: Monitor in a Box does not require that ansible be installed on all the servers. We only require that ansible be installed on the one machine that orchestrates the setup of Monitor in a Box.

<comment><USER8> Ah, thanks for clarifying, I misunderstood that part of your FAQ.

Looking forward to trying it out.

<comment><AUTHOR> The free version doesn't provide any visualizations other than what you see in the icingaweb dashboards. The icinga demo (not grafana) should give you an idea of what I mean: [https://solutions.stacktile.io/demo](https://solutions.stacktile.io/demo)

In the spirit of shameless self-promotion, I invite you to clone our git repo and see for yourself! :-)

</comment></comment></comment></comment><comment><USER9> Is it just me or do these pitch pages always seem very light on what the software actually does... does it aggregate logs? LD tweaking maybe? Is it a kernel module? What is this technology?

<comment><AUTHOR> Hi Kristopolous,

In a nutshell, Monitor in a box is a system/application monitoring solution based on Ansible, Icinga 2 and Grafana.

I would like to kindly point you to our demo to see what our software does.

We've also made our code available at github, and I invite you to check out our README to get an idea of how to begin using.

I hope that helps clarify what we're trying to do.

<comment><USER9> The github readme is far better. Have you ever been to the vendor floor of a Linux convention? It's like 30-40 "monitoring" and "devops" solutions with a web dashboard that in my mind are indistinguishable complex solutions to simple problems. I'm looking for simple solutions to complex problems...Thanks for responding

<comment><USER10> > simple solutions to complex problems

Too true. Messaging that is relevant to both technical people ("devops") and business (management, procurement, etc) is a hard problem to solve, though!

There seems to be a marketing tendency to either gloss over the technical ideas behind a product, or make technical details front-and-center and leave anyone less than 100% technical searching for a product that they can grok.

This is something we're struggling with right now: our basic messaging for Userify (ssh key management), which is actually a fairly simple and sane product, has gotten a bit out of hand as well: our support team is fielding frequent questions like, "what does each edition do." We've got to get on top of that and get some comparison matrices or something up. Applauding the OP for a nice, clean landing page that conveys most of the relevant details, but as you point out, the Github readme is far better. There's a lesson in there somewhere.

</comment></comment></comment></comment><comment><USER11> Honestly, fixing Icinga's broken architecture (shared with Nagios, Shinken, Zenoss, and Zabbix) with a bunch of shell and Ansible scripts doesn't seem like very robust solution.

And install instructions from README on GitHub looks like one big let's not, with half a dozen of modernish tools that obscure what's actually happening (basically, `apt-get install icinga2' and putting some config files in place).

<comment><AUTHOR> Hi dozzie [edit: typo],

I can entirely sympathize with your comment here, but I'd like to try to quickly present a contrary perspective:

Indeed there are architectural trade-offs made by every monitoring system, and icinga2 makes some that we also have found to be frustrating: one such example that comes to mind for me personally is that icinga aims to maintain backwards compatibility with its historically-derived nagios configuration file syntax which is difficult to understand and hard to parse in an automated fashion.

On the other hand, there are exampls of architectural choices that I believe icinga gets right: It implements an approach to secure and authenticated metrics collection that virtually every other monitoring system leaves as an "exercise" for the user. It provides checks and alerts and notification thershholds by default, which many other monitoring systems don't.

We build monitor in a box to attempt to highlight one particular approach to using icinga 2 which we find works for us. We attempt to be systematic and through in our approach, aiming for a reproducible, Ansible based implementation that emphasizes modularity and code reuse. We invite everyone to try out our open source offering to decide for his or her self whether the benfits of running icinga 2 in this fashion outweigh the drawbacks.

<comment><USER11> > Hi dozie,

It's two "z" there.

> [...] icinga aims to maintain backwards compatibility with its historically- > derived nagios configuration file syntax which is difficult to understand > and hard to parse in an automated fashion.

Parsing Icinga/Nagios configuration file is easy, even if you count object templates ( _register=0_ and _use foo_ ) and use handcrafted parser instead of generated one. The syntax is not a complicated one. I don't know what problems have you encountered.

> On the other hand, there are exampls of architectural choices that I believe > icinga gets right: It implements an approach to secure and authenticated > metrics collection that virtually every other monitoring system leaves as an > "exercise" for the user.

Oh, this is more or less easy task if your monitoring system has some secret (e.g. X.509 certificate) exchanged with the monitored hosts, and can be bolted on pretty much any monitoring system with some stunnel-fu (which proves that it's nothing on the _architecture_ side of the system).

It's _sharing_ that secret in a _robust_ and _automatic_ way that is quite difficult. I doubt Icinga does anything better than the rest of the crowd.

> It provides checks and alerts and notification thershholds by default, which > many other monitoring systems don't.

Once you have an established flow of monitoring messages, then thresholds, alerts, and notification become simple stream processing and consumption. Sure, Icinga and others give you this simple processing in the package, and some systems give you a few more queries than others (e.g. originally Nagios only processed what I call "state", while Cacti only processed metrics, and Zabbix processes both). But this processing rarely is complex. And none of them give you an ability to process _the data stream itself_.

And then there is this almost universally shared requirement that you need to define all the instances of hosts and services beforehand, only differing how the template system is implemented in a given monitoring system.

You can't just start collecting data about servers as they get installed and about services and resources as they emerge and disappear. No, you need to tell the monitoring system that it should expect data from this host and this service (collectd, Graphite, and InfluxDB got it right here).

It is useful sometimes for monitoring system to _expect_ some data to show up (and possibly alert that it's missing), only sometimes, not all the time. Usually other data can easily cover the scenario where something silently goes down, and there's still this "stream processing" thing I mentioned that can just monitor that some data stopped being received.

<comment><USER12> > You can't just start collecting data about servers as they get installed and > about services and resources as they emerge and disappear.

You can do that in Zabbix, it has two functions to discover hosts (called "network discovery") or "features" like running services or e.g. switch ports (called "low level discovery") and apply templates based on certain query results (open ports, SNMP values etc.). Alerting the lack of new incoming data is also possible. I used Zabbix a lot until a year ago and liked it much more than Nagios+descendants.

<comment><USER11> Discovery mechanism like this may be nice in some situations, but it doesn't change the underlying architectural problem: you still need to go through central configuration of monitoring system to get something watched.

This architecture results in much longer feedback loop, [object to be monitored -> discovery -> config -> collection engine -> probe -> object's state -> storage] vs. [object to be monitored -> probe -> object's state -> storage]. And you have to move requests/network packets back and forth just to collect the usage for each CPU on a machine separately (or NICs usage, or filesystem usage, or VM/LXC guests, or Apache/nginx vhosts, or...), because the knowledge what objects are there to monitor is on the monitored host's side, not on the monitoring system's side.

And you're limited to whatever resources this predefined discovery mechanism supports. You can't easily write your own probe that discovers things on its own.

And on top of that, discovery mechanism doesn't allow temporary, ad-hoc defined things to be monitored. You can't imagine how often I set a screen with a shell loop to collect a metric or watch state for this one particular process I was debugging:

      while sleep 1; do foo; done | tee /tmp/foo.log

Why not chart that from a monitoring system? Why not display its state on a dashboard? Why not alert in regular way?

</comment></comment></comment></comment></comment><comment><USER13> Really nice setup, I'm glad to see Ansible being used to orchestrate the machines. I really do like that system for it's ease of use and low learning- curve.

</comment><comment><USER14> As someone from the Windows world, I'm always surprised to read things like:

"That said, the more specific you customize your monitoring, the more detailed an understanding of these components you will need."

This sounds as bad as what I've heard about Nagios. Why does it have to be so complicated?

</comment><comment><USER15> I'm so stupid, can someone ELI5 what this is for?

</comment><comment><USER16> Icinga? Really?

<comment><USER17> Yes, really. Feigned surprise adds nothing to a conversation.

[https://www.recurse.com/manual#sub-sec-social- rules](https://www.recurse.com/manual#sub-sec-social-rules)</comment></comment>


Prevent CDN caching your updated JavaScript files - <AUTHOR> http://sketchboard.io/blog/2015/05/11/minish.html

<comment><USER2> TL;DR

extract some value from the file that changes with its content --like content's md5, or modified timestamp-- and append it to the file name

for example, let's say "index.js" and its md5 is "30c2234" (shortened for readability)

        <script src="file-30c2234.js">

later when you modify the file, the hash change, and clients start to request the new one.

this allows to set cache's evict time in doomsday</comment>


Game Boy emulator for TempleOS - <AUTHOR> https://github.com/tramplersheikhs/cherub <comment><USER2> You're doing the lord's work, son. Literally.

</comment><comment><USER3> What's it like to code in this environment?

<comment><USER4> Divine</comment></comment>


Why you get ideas in the shower - <AUTHOR> http://www.scottberkun.com/blog/2011/why-you-get-ideas-in-the-shower/ <comment><USER3> My wife claims that I should charge my company for showering time given the number of times I emerge from the shower and start taking notes on an idea. Usually a shower follows two enormous cups of coffee.

I'd be curious to see a bit more detail on the physiological basis of this. I do plenty of things where you're able to zone out a bit, but none of them have remotely the same idea-generation rate as being in the shower. Can't help but wonder whether a big pile of warm water all over the body does something to blood flow in some useful way. If I could remember any physiology this would be the point to use an impressive word like vasoconstriction or vasodilation or some such. :-)

<comment><USER4> _I'd be curious to see a bit more detail on the physiological basis of this._

My reply to your remark was placed under the wrong comment (that's what I get for posting at some ungodly hour while suffering insomnia):

<http://news.ycombinator.com/item?id=2531927>

</comment></comment><comment><USER5> One of the most mentally productive times of my life so far was when I had a 1 hour (each way) commute in a car with no CD player. I was alone in my thoughts for an hour a day with absolutely 0 distractions. Driving was just enough to keep my brain awake, but could get a low enough thread-priority to let me think.

I've replaced the driving with biking (I live a lot closer to my job now), but it honestly isn't quite as good. Some of the stuff I came up with then (this was about a year and a half ago), I'm still fleshing out now.

Another thing that's close to driving, but not quite as good is yard work. Something about the sound of lawnmowers and weed whackers is really conducive to thinking.

<comment><USER6> Similar for me for several years when I lived in Seattle, but had a job across Puget Sound in Kitsap County. Each way each day I had anywhere from 30 minutes to an hour on a ferry (depending on which ferry I decided to take that day). I could just sit in my car, with some music on, and either technical material I needed to read, or a pad of paper and a pen working out design ideas.

No distractions, and if I needed a break to let something turn over in my mind, I could simply step out of the car watch the ocean, or go up to the passenger decks and have a seat or get a snack from the cafeteria. If it was the morning, they had nice breakfasts available.

</comment></comment><comment><USER7> Early on I learned that Juggling was a great way to get my conscious mind out of the way of my subconscious so that I could actually retrieve information from it about solutions to problems.

Like a lot of people I know, my brain works on coming up with solutions to 'problems' 24/7, whether I want it to or not (much to my spouses dismay sometimes) And while effective getting those solutions out of the queue require either isolation (camping is great, the shower is ok if a bit short) or to have my conscious brain not focused on trying to pull the answer out.

Juggling (and as it turns out for me piano playing) has the property of applying a temporal focus to my brain which prevents it from interfering with my subconscious. Weird I know, but folks I know who study such things consider it fairly normal. I know a guy who plays FPS video games when he has a really hard problem he's working on, same sort of thing.

<comment><USER8> The problem with inspiration-based problem solvers is that it's always extremely difficult to predict when they will solve a problem.

This has been a real issue for me and the fact that my off-focus activity of choice is arsing about on the internets and pretty much everyone I ever work with thinks all I ever do is slack off.

</comment></comment><comment><USER9> Related is Paul Graham's essay, "The Top Idea in Your Mind" [<http://www.paulgraham.com/top.html>]. He doesn't address the question of _why_ but proposes shower-taking as a litmus test for finding out what the top idea in your mind is (or your ambient thoughts, as he dubs it).

First paragraph:

        I realized recently that what one thinks about in the
        shower in the morning is more important than I'd thought.
        I knew it was a good time to have ideas. Now I'd go
        further: now I'd say it's hard to do a really good job on
        anything you don't think about in the shower.

<comment><USER10> _I'd say it's hard to do a really good job on anything you don't think about in the shower._

That's so true. My morning shower is where I think about what my goals are for the day- it's also usually where and when I come up with the seeds of the best strategies for achieving said goals. If I haven't found a executable solution by the end of my shower, it usually won't come to me until 3am later that night when all other distractions are gone.

</comment></comment><comment><USER11> Oh, great. As if I don't have enough things on my to-do list. Now I have to try this "shower" thing.

(Also, I seem to be really sparse in the idea department. Or rather, in the interesting idea department. I've spent most of the last decade stumbling onto ideas that I could immediately dismiss as being too obvious to be interesting, whether or not they could be financially rewarding, or already done by someone else. There needs to be some sort of affordable R&D/think-tank outsourcing you can do if you're a one or two man job looking for ideas - heh.)

<comment><USER12> I worked full-time on readwarp.com for 8 months. When I started I was terrified that I'd run out of money. But when I finally gave up I found I had more runway than I'd projected. What I ran out of was ideas. I'm hoping next time that having a cofounder will help keep up a stream of ideas.

\---

It's not about finding an interesting idea fully formed. It's about constantly generating new things to try, new trails to blaze.

\---

 _"As if I don't have enough things on my to-do list."_

If it's closing you to new ideas your todo list is too much baggage. I've grown _super_ sensitive to this; I prune my todo list all the time[1].

It's hard to be open to new ideas all the time, of course. Being too open can interfere with actually doing anything. The author of "Flow" says successful people tend to alternate between being open and exploratory, and being closed/focussed on getting something out the door. I imagine it as weaving alternately on either side of the ideal line. It's impossible to perfectly balance both sides, but you don't have to be perfect.

[1] My todo list is in version control for many years now, and every now and then I check out what it looked like a month or a year ago. It's amazing to me how rapidly items turn over. Most ideas form and die within 2 weeks.

</comment></comment><comment><USER13> Every few weeks I become so distracted by thinking about a problem in the shower that I'll rinse, lather, and repeat three, four, or far more times without realizing. Only seems to happen in the morning, which makes me think it has something to do with the problem-solving activity of my subconscious during sleep. When it occurs, though, what a fantastic window of creativity and focus!

</comment><comment><USER14> It makes sense that the shower is somewhere you can really relax and think. It's the one place where you really can't be doing something else that is more important. You can't check your email, you can't be thinking that you should be writing a paper for some class. You can't do anything but shower and think.

In college there were multiple times that I came up with solutions to programming problems while I was in the shower because my mind actually had time to take a break.

</comment><comment><USER15> Not that it's really related to the actual substance of the article, just to the title, but personally I've never had any ideas, or even done any real thinking about current ideas, while in a shower, whereas when having a bath, I have.

I don't know if that's completely random, whether it's something specific about me, whether it's because I will spend longer in a bath than a shower, or because I enjoy having a bath more, and tend to relax more. Or some other reason.

<comment><USER16> If showers are not a part of your routine, then, when showering, your mind will be preoccupied with things like "how to shower," "how not to slip," "how not to get burned with hot water," "how to control water temperature," etc., and will not be able to achieve the state of relaxation necessary for generation of new ideas.

The key is that the activity has to be both relaxing and routine (double "r"...). For you, it's bathing, for others it's showering, yet for others it's walking in the woods. If the activity is not relaxing, you will be preoccupied with how to control it and with resulting stress. If the activity is not routine, you will be focused on its novelty rather than letting your mind wander on its own.

<comment><USER15> Maybe subconsciously it's more stressful for me to have a shower, but I have far more showers than baths, and certainly I don't need to really think about any aspects of it, consciously.

It's just that in a shower I never decide to relax and enjoy it, it's always a method of cleaning, or of waking up, or of heating up, not an activity for the sake of enjoyment.

</comment></comment></comment><comment><USER17> Diving Slate: [http://www.amazon.com/Scuba-Dive-Underwater-Writing- Slate/dp...](http://www.amazon.com/Scuba-Dive-Underwater-Writing- Slate/dp/B001O041F0)

Get one of these, and jot your ideas down in the shower. (Don't forget to buy cleaning fluid: [http://www.amazon.com/Biodegradable-Dive-Slate-Cleaner- Refre...](http://www.amazon.com/Biodegradable-Dive-Slate-Cleaner- Refreshes/dp/B001F916N0))

</comment><comment><USER18> My work day is usually 8 hours of implementing whatever idea I came up with while in the shower that morning. If nothing comes to me during the morning routine, I'll have a really crummy, unproductive day.

I _might_ be able to take an hour for a walk around the neighborhood to clear my head to get ideas, but generally even walking around trying to not get hit by vehicles or other pedestrians still distracts me.

</comment><comment><USER19> I get ideas while out walking, no iPod and preferably no other people about. Exercise too (of a sort).

</comment><comment><USER20> It's not about taking a shower - it's about disconnecting from active stimulation for a few minutes. A consequence of our information society or "information addiction" is that a lot of people are really scared to just sit down and do nothing. A lot of people are afraid of being alone in their head with their own thoughts.

When you're taking a shower, this is often the only time during the day when you're not actively engaging your mind. Just taking a walk (no iPod allowed) or just lying down on the couch staring at the ceiling, or sitting in your car after you've parked will give the same effect. Guaranteed. You might experience a few minutes of discomfort as your consciousness grasps for something to hold on to.

</comment><comment><USER21> I've always found the shower to be effective for thinking because the combination of white noise and the routine of washing occupy the mind so well that deeper thoughts can emerge.

Taking showers to mull over problems is one more advantage to working from home :)

</comment><comment><USER22> Sensory deprivation is also a safe way to have an intense psychedelic experience, without having to ingest chemicals. Go float in a tank for an hour or two, and you'll be astonished at some of the crazy thoughts you'll have.

<comment><USER23> Yap yap yap.. my favorite of the lot. Better then meditation. The word "psychedelic experience" might be stretching it but you do get minor visual & auditory hallucinations that are basically your conscious mind observing your subconscious.. stuff monks train for years to achieve in standard meditation while in a tank - bam! Here's a 2 part blog post I wrote on Isolation Tanks ~ [http://blog.ernestsemerda.com/2009/09/03/floatation- isolatio...](http://blog.ernestsemerda.com/2009/09/03/floatation-isolation- tank-fringe-science/)

</comment></comment><comment><USER24> This happens so much to me that I got a dry erase marker and write down my ideas on bathroom mirror as soon as I get out of the shower ... naturally, everyone who uses my bathroom thinks I'm crazy.

</comment><comment><USER25> I tend to do my best thinking when out for a walk. There's a greater chance of interruption, though, so I find myself increasingly heading towards less populated areas with fewer streets to cross.

</comment><comment><USER26> People who are into this kind of thing will probably like "Your brain at work" by David Rock. It covers this topic and a few more - it's pretty interesting stuff for developers and knowledge workers. There's also a tech talk here:

<http://www.youtube.com/watch?v=XeJSXfXep4M>

Also, get Pragmatic Thinking and Learning by Andy Hunt. Also covers these topics and helps people understand learning, creativity and how to exploit the way you work and think to, well, learn better.

</comment><comment><USER27> For more specifics into the cognitive science behind why this is - <USER2> good book, which has lots of wonderful references to studies on this topic (amongst other things), is "Your Brain at Work" by David Rock. Or, for the general overview you can watch the Google Talk at <http://www.youtube.com/watch?v=XeJSXfXep4M>

</comment><comment><USER28> For those commenting that the White noise is a factor:

<http://www.simplynoise.com> and also their downloadable thunderstorm soundscape recording: <http://simplynoise.com/download.php?key=18336dd65313> (Google result, not sure why it thinks a donation has happened).

</comment><comment><USER29> I've written todo lists backwards on the sliding glass doors, on the steamed up glass doors, so I could write them down when I get out of the shower. That particular day, I had like 5 ideas I really didn't want to forget, and this was the only way I could think of... it worked, mostly. The lower I got on the door, the harder it was to read.

</comment><comment><USER30> It's just amazing to know everybody is getting ideas in showers - I used to think I was the lonely weird one...

</comment><comment><USER31> while i don't disagree with the article, i always assumed the shower was particularly potent because it's first thing in the morning, after a full night's sleep. so you've got a whole 8-10 hours of subconscious activity to catch up on.

<comment><USER32> Not everyone showers in the morning, and those of us who don't also get ideas in the shower.

<comment><USER31> hmmm. do you get as many, or as good ones?

[also, maybe i'm just jaded, but the way i read your reply sounds as though you're indignant - as if i've committed some terrible (almost racist) offense by making assumptions about other people. if you are offended, i apologise, but i mention it more because i wonder if it's just a curious consequence of the kind of society we now live in. i have no idea how you would phrase what you said to avoid giving that idea, for example...]

</comment></comment></comment><comment><USER33> If you are crazy extreme, the Motorola Defy (android phone) is waterproof (they only claim "water resistant" but people have used them underwater in swimming pools, check youtube).

</comment><comment><USER34> I get the best ideas when I'm not trying to come up with an idea, which is a paradox. Though never had an idea in the shower that I remember. :)

</comment><comment><USER35> I get ideas when I am sleeping.... all the time...

</comment><comment><USER36> I often take 20 to 40 minute showers in the morning. This is my meditation.

There isn't too much going on to distract me.

</comment><comment><USER37> I get ideas right before i fall asleep.

</comment><comment><USER38> When I started carrying a notebook around, I noticed that I seemed to have more ideas. In actuality, I think that I had ideas pretty regularly without the notebook, but I foolishly tell myself, "ah, that's good, I'll have to remember that." Ten minutes later, I've forgotten the idea. An hour later, I've forgotten that I've forgotten an idea...

</comment><comment><USER39> Most of the ideas I get in the shower aren't appropriate here! :)

</comment><comment><USER40> I just took a shower................nothing.</comment>


How do you refresh your mind during a study break? - <AUTHOR> http://ask.metafilter.com/58373/How-to-refresh-your-mind-during-a-study-break

<comment><USER2> For me, this has changed everything:

<http://www.mindfold.com/></comment>


Dear Humanities Profs: We Are the Problem - <AUTHOR> https://www.chronicle.com/article/Dear-Humanities-Profs-We-Are/243100 <comment><USER2> You can honor expertise while acknowledging bias and _still_ come up with empirically correct conclusions (otherwise I wouldn't be a scientist) that are based on relatively basic shared values. Expertise is an antidote to propaganda when people think critically about the problems at stake. As the author notes, David Foster Wallace was right that cynicism is lethal; but cynicism can also be enabling in those who are free thinkers. The article raises important points about how we got ourselves into this mess. Good reading. As usual it occurs to me that the goals of scientific exploration are as universal as we get because they aim to (a) discover the unknown and (b) to make the world better through discovery. Take that, humanists!

</comment><comment><USER3> There author doesn't mention the fact that he and other profs in humanities are funded by a ponzi scheme of students tricked into paying for degrees that don't have salary value.

<comment><USER4> It is pretty unusual for grad students even the humanities to pay tuition. For undergrads there is great value in teaching this material even to non-majors.

</comment></comment><comment><USER5> Unbearable verboseness is also part of the problem.</comment>


Sirum (YC W15) gets unused pills to help cut costs on medication [video] - <AUTHOR> https://www.today.com/video/nonprofit-gets-unused-pills-to-help-cut-costs-on-medication-68874821846 <comment><USER2> I once tried to return an unopened, sealed 30 day supply of overpriced $150 medication to one of the big pharma chain stores and I was told that they won't accept refunds because there could be a chance someone tampered with the medication.

</comment><comment><USER3> Seems kind of trusting. Pills can look similar.</comment>


IBM Releases Fully Homomorphic Encryption Toolkit for macOS and iOS - <AUTHOR> https://www.ibm.com/blogs/research/2020/06/ibm-releases-fully-homomorphic-encryption-toolkit-for-macos-and-ios-linux-and-android-coming-soon/ <comment><USER2> From the library readme [1]

> The database is a key value store prepopulated with the english names of > countries and their capital cities from the continent of Europe. Selecting > the country will perform a search of the matching capital. On a 2019 Macbook > Pro laptop, the example searches take under 80 seconds.

Does this have a heavy performance cost for even toy applications?

[1] [https://github.com/IBM/fhe-toolkit- macos/blob/master/Getting...](https://github.com/IBM/fhe-toolkit- macos/blob/master/GettingStarted.md#step-8)

<comment><USER3> The example is called "Privacy Preserving Search". If the server could see which row was accessed, that would not satisfy the privacy requirement. This implies that each query needs to process all the rows equally (and all in the same complicated encrypted way).

Provable privacy like here or in zero-knowledge proofs is generally extremely expensive because every possible execution path needs to be taken each invocation. This is multiplied by the overhead from each simple operation becoming a complex cryptographic one.

<comment><USER4> Seems like the constraints of this basically mean that you might as well just stream the database to the client and let them do the query.

<comment><USER5> One of the scenarios is that the cloud provider has an algorithm they want to keep secret. Clients want to use the algorithm but dont trust cloud provider with their data.

Honestly though, i mostly find FHE interesting theoretically. The fact that its possible at all is black magic. I'm sure if it ever gets remotely efficient people will come up with more creative applications, but in the meanwhile its resesrch worth it for research sake.

<comment><USER6> > _One of the scenarios is that the cloud provider has an algorithm they want > to keep secret. Clients want to use the algorithm but dont trust cloud > provider with their data._

That would indeed go a long way towards resolving the issues caused by the way SaaS is done. It would let us decouple compute provider from the service, in a way in which it would be the end users who are free to chose where the computation happens, and they'd own all the data by default, while the business secrets and IP of the service provider would still be protected.

Shame to see it's so computationally expensive, I was really hoping this kind of computing would take off.

</comment></comment></comment></comment></comment><comment><USER7> I _feel_ this should be massively game changing. But I cannot work out which game.

All the examples I can find seem to be around levels of privacy preservation that I just think if i was that concerned i would not risk sending it to anyone else anyway.

<comment><USER8> I am one of the developers, so I wanted to respond. Imagine you want to search for a coffee or restaurant nearby. You can now use an app which cares about your privacy by encrypting your location, and encrypting the intent of your food search (maybe you want to seek out only italian, chinese, mexican, or coffee shop places) and the app, sends that encrypted data to the cloud to retrieve an encrypted response back wherein the app, nor the backend service could mine anything about you or your preferences. It just satisfied your request. In such a scenario the app would likely be paid, but the service wouldn't use you as the product to grab all your information...

<comment><USER7> Thank you. But, and I respect the work you and others are doing, this sounds very much like other technological solutions in search of a problem - the most obvious is bitcoin replacing fiat money.

I think most of society would be happy with regulatory changes. Preventing companies from exploiting personal data is fairly simple in a democratic legal framework.

There are yes governments and states where democracy does not exist, but in that case they simply won't let me use such a search service anyway, so it's dubious the technology would be beneficial there.

Some time in the past decade I realised that software has only limited ability to change the world - it simply does not have the leverage to overcome all the politics of the world. If we want utopia, we must learn Judo to use the weight of the world against itself.

I remain optimistic that we can make this world better with these amazing new technologies, but I fear they cannot succeed on their own.

But I hope you can prove me wrong !

</comment></comment></comment><comment><USER9> Awesome. Anyone working in this field able to tell me what is the current overhead for FHE using this toolchain?

<comment><USER10> Last I looked, HElib was one of the slower implementations. That said, even in the best case, HE libraries are so slow, that I don't think "overhead" really captures the paradigm correctly, because the performance is highly dependent on the application. The best case "overhead" (doing some operation that the HE scheme natively supports, e.g. arithmetic over a very specific finite field) is probably 5-6 orders of magnitude.

<comment><USER11> Is there any application that will benefit from FHE? I can't think of anything where taking a hit of at least 5 orders of magnitude is worth it over doing the calculation locally on a trusted CPU.

<comment><USER10> It's not just about outsourcing compute. There's lots of interesting things you can build on top of an FHE primitive. The linked blog post has the private information retrieval example (the database owner doesn't want to send you the whole database, you don't want the database owner to know what you're looking for). I have a worked example for machine learning here: [https://juliacomputing.com/blog/2019/11/22/encrypted- machine...](https://juliacomputing.com/blog/2019/11/22/encrypted-machine- learning.html) (The model owner doesn't want to share the model, you don't want to share the image you're asking them to process).

<comment><USER12> What's the advantage of using FHE in this example as opposed to Secure MPC?

<comment><USER10> The communications latency of MPC would probably exceed the time required for FHE in this particular example.

</comment></comment></comment></comment></comment></comment><comment><USER13> We need a fully homomorphic encryption scheme specifically designed for encrypting executable code; such that encrypted code is also a meaningful code, visible arities of instructions does not change in encryption, operands get encrypted in the same manner as but separately from instructions.

<comment><USER14> You should check out the Cingulata project: [https://github.com/CEA- LIST/Cingulata](https://github.com/CEA-LIST/Cingulata)

</comment></comment><comment><USER15> Thats awesome! Ive actually been working on my own iOS/ MacOS port to Swift for Microsoft Seal here [https://github.com/mmroz/SEAL](https://github.com/mmroz/SEAL). Would love some feedback :)

</comment><comment><USER16> "Toolkit" seems like a bit of a stretch - as far as I can tell this is just a small example progam which uses HElib.

<comment><USER8> Sure, tt is a first release integrating the HElib library, dependencies, and a working sample project that you just click the play button to get running that you can import directly from git into the platform IDE of choice. The intent is for more demo apps to be shipped along with other convenience utilities if people show interest. We could have left it behind closed doors until it was "perfect" but that is not really how we prefer to work. The response has been great, so I hope we double down and improve the toolkits accordingly with community help and input. It is an open-source project without a version number, so it may take some time but we will get there.

</comment></comment><comment><USER17> Is this in some form related to IBM Privacy Passports? They are also intended to disclose partial information to multiple parties from the same data.

</comment><comment><USER18> How does FHE handle, say, a quantum cracker?

<comment><USER10> I assume you're talking about the quantum resistance of the underlying schemes in use? My understanding is that all the current schemes of practical interest rely on the hardness of (variants of) LWE ([https://en.wikipedia.org/wiki/Learning_with_errors](https://en.wikipedia.org/wiki/Learning_with_errors)), which is believed to be hard even if you have a quantum computer.

</comment></comment><comment><USER19> Why only for Apple products?

<comment><USER20> >That was until today thanks to a new toolkit we are making available for MacOS, iOS and soon for Linux and Android.

<comment><USER21> Anyone know why Windows is left off this list? Is it just that the supported OS's share a *nix background so porting is more straightforward? Or is there some deeper reason why?

<comment><USER8> The library the toolkit is based on is called HElib and the developers (myself included) did not have the bandwidth to port anything to Windows. The core library and dependencies are Linux native. As it is, we are a bit behind on the Linux and android toolkits. With limited time and energy, we chose the most closely related platforms that all have Unix like underpinnings. Thanks for the question! If you have more feel free to join in the public slack conversation:

[https://fhekit.slack.com/join/shared_invite/zt-e35rax8l-_ZbB...](https://fhekit.slack.com/join/shared_invite/zt-e35rax8l-_ZbB2XuF3WcXCM2mDe~AZQ#/)

</comment></comment></comment></comment><comment><USER22> Worst video ever.</comment>


Ask HN: How can I get my target market out of Facebook and into my platform? - EO-IO Hello HN,
I live in a country where virtually every business related situation is done on facebook groups/pages.
To illustrate here are a few examples :
- If an HR guy is looking for a freelance dev/marketer/whatever for his company, he goes to Facebook freelance groups and just posts about it to get dozens of CVs.
- If someone is looking for a review on a particular restaurant, they go to another facebook group to ask about it.
- If someone is looking to buy a particular item that is not available on the corner of the street, same.
- If someone is looking to get traffic for their new product, facebook groups again.
And the list goes on.
My question is : How can I get those people to ditch facebook and use my platform instead to fill their needs ? OR How can I turn this into my advantage somehow ?
Cheers <comment><AUTHOR> If using fb for all these use cases is _working_ for people, why would they switch? It's free and ubiquitous, there would be no reason to use something else unless fb fell out of favor en masse.

You haven't been very specific about your use case but it sounds like you may need some critical mass to be successful (chicken and egg problem?). Probably you need word of mouth from a core set of people that love the hell out of your product and will actively convince people to switch.</comment>


Love Hurts: So let's stop infantilizing women and demonizing men - <AUTHOR> https://www.persuasion.community/p/love-hurts-511 <comment><USER2> I read this, then reread it because the punchline didn't match the tone throughout the article.

The point is that "consent is sexy" doesn't go far enough towards teaching people how to have a healthy relationship. No one is disagreeing with this, nor that infantilization and demonization is a long standing problem. But we need the step that "yes, consent is important" first to get to the better parts, just like addition needs to be learned before algebra.

The article turns consent into a straw man, and then doesn't give a good framework to replace the social framework of consent, instead showcasing high- level concepts that aren't easy to teach.

A more meaningful conclusion is to add philosophy as a discipline back into schooling, so sex-ed doesn't need to do double-duty as ethics.

</comment><comment><USER3> Relationship conventions are simply not something everyone in society can agree upon. I don't think most people can even commit to a single set of relationship conventions for themselves over a ten year period.

Aside from the broadest guidelines of decency (that no one should endure involuntary harm, or limit another's freedom) I am pessimistic that people could rally around any universal set of rules for relationships.

Since that's the reality, I think people need to be less sensitive about whoever they are offending with their ideas, inevitably, as long as they don't involuntarily harm or constrain someone else. They also need to quit evangelizing for whatever their morals are, this second, because they will probably be different tomorrow.

We still have a long ways to go preventing involuntary harm, and fostering freedom. Maybe if people focused on that, things would be easier.</comment>


Ask HN: Is Disqus "Truly SEO-Compatible" like they say it is? - <AUTHOR>

I was just reading the Disqus 2012 announcement blog post:
http://blog.disqus.com/post/22325598158/try-out-disqus-2012
And on that page is says that Disqus 2012 is, "Truly SEO-compatible. The new Disqus integrates in a way that is naturally discoverable by Google — out of the box, without any extra work."
This leads me to believe that if I search for a comment on google, it should show me the page where that comment was written.
To test that out, I found a comment on the blog post I mentioned above, wrapped it in quotes, and searched it using Google.
The comment reads, "I feel the voting system is ripe for abuse and will be used to silence dissenters. By making it anonymous you're really making it too easy for that to happen."
No results were found.
So is Disqus 2012 really SEO-compatible? <comment><USER2> I just tested the same thing on Fred Wilson's blog. You're right, it doesn't work. Disqus is probably wrong to make that claim. If they had a very simple Wordpress plugin they could serve up cached results to Google in the server- generated HTML (mostly just for Google) and still use Javascript the same way they do now.

That would be as SEO-compatible as possible.

<comment><AUTHOR> Yeah, that's what we were thinking too, but it wouldn't be out of the box then, right?

<comment><USER3> That's unrelated to Disqus 2012. Disqus 2012 is indexable by Google without any software (such as a WordPress plugin) being installed on the host's server.

</comment></comment></comment><comment><USER4> Disqus comments are loaded with AJAX as you probably all know. Try disabling Javascript, no comments show.

This is most certainly not SEO friendly, as it is not discoverable by Google. I have heard that Google can run Javascript in crawl and index content that is loaded this way, but it's still a bad idea to rely on that. Also worth considering is that they might only enable this sort of content discovery on sites with enough value (large enough).

It seems to be a design problem to me, because it's a third party plugin I don't see any easy way to get around this, unless Disqus are talking directly to Google to get this solved.

From a purely SEO perspective in my opinion and from my understanding, it's bad, and SEO benefits are non-existent/minimal. This is one of the reasons I don't like surrendering control of some important aspects of my websites to third party services.

</comment><comment><USER5> At least it's not an issue with the speed of Google indexing, as this HN post is already in their index, and at the top when you search for "I feel the voting system is ripe for abuse and will be used to silence dissenters. By making it anonymous you're really making it too easy for that to happen."

<comment><USER4> Google indexes popular websites very fast, but smaller websites wont be crawled at this speed.

</comment></comment><comment><USER3> We'll be talking about this more in the future, but we have confirmed with at least one major index that the content will be indexed as expected within the new system.

Edit: And since we seem to have already named Google, it's obvious who that is.

<comment><AUTHOR> Hey Zeeg,

Any recco's/best practices on how to best give indexing attribution to the correct site? Any resources you can point us to?

Thanks

Max

<comment><AUTHOR> Also - will anyone be able to take advantage of these developments, or do you need to have a special deal in place with Google?

</comment></comment></comment><comment><USER6> [http://www.tomshardware.com/news/google-googlebot-ajax- javas...](http://www.tomshardware.com/news/google-googlebot-ajax-javascript- content,13881.html)</comment>


An important lesson about pitching your app at a high school assembly - <AUTHOR> http://kut.org/post/besomebody-speaker-draws-controversy-austin-high-school?utm_source=Facebook&utm_medium=Social&utm_campaign=FBKUT4951 <comment><AUTHOR> tl;dr - the lesson here is "don't do that."</comment>


Is Desktop Development Dead? Or Still Worth It? - <AUTHOR> https://insights.dice.com/2020/03/04/desktop-development-dead-still-worth-it/ <comment><USER2> I think so. For productive office jobs, a desktop is still a must have. Audits, quality assurance, production planning, sales planning, reclamations, presentations, any form of computer aided engineering, accounting... just random examples on top of my head.

Sure, there could theoretically be a a webapp that can do all this, but there isn't. A penalty is that your QA SaaS service needs to interface employee information and maybe access article information living inside your ERP. Problems start to occur here.

Apps on the web or phone are good for any workflow where your input is basically "yes/no". I think html can be a good compromise for UIs, but that isn't enough to replace desktop software.

I don't see many webapps in any production critical process, they only pop up for some administrative tasks and even that is limited. Maybe you are an IT consultant with everything in the cloud. Or maybe you deliver food or offer transport and orders are managed in an online service. That works, but widespread applications are limited.

</comment><comment><USER3> I don't think users care how software is deployed. (ie: does it live on the web or in their desktop?) But what looks dead to me is _desktop-specific_ development.

With modern UI frameworks and Electron, you can deliver an app that looks "desktop" to the user but is written with standard, simple web technologies. Those apps interact with your peripherals and are indistinguishable from desktop apps.

The advantage to letting go of proprietary "desktop" software is that a single codebase can actually look and work the same on PCs, Macs, and Linux -- something no desktop provider has given us.

</comment><comment> non-entity I mean for some applications you're going to gave to have a desktop app, particularly anything that communicates with external devices or most OS related components.

Although the ways people will convince themselves otherwise are pretty comical. I had written a desktop app that communicated with a card scanning device via a simple protocol over a serial port. Someone proceeded to tell me that desktop apps in 201 _X_ are bad. They told me the preferred alternative was to write a webserver that did the serial port communication and also served a web based UI which seemed ridiculous at best.</comment>


Keep up with the latest research in Computer Science - <AUTHOR> http://www.elseif.net

<comment><USER2> So other than what the others have said, which I think is pretty reasonable (weird unattributed quotes and no about page, etc).

What you should maybe do is show content. If you don't have the userbase filled with tens of people ready to sing your praises, or you don't really want to put aside time to think up copy for extra about/contact pages, at least give the user a glimpse as to why they can't live without the service

You could have like an 'editor's weekly pick' of like 4 or 5 articles, that you think a lot of people are interested in, and give a preview of what your browsing features (or at least what the articles) look like. Then, people have a reason to want to sign up, right?

[EDIT] - editted for pretentious-ness, hopefully I got all of it out

<comment><USER3> "[EDIT] - editted for pretentious-ness, hopefully I got all of it out" \- Appreciated. :)

</comment></comment><comment><USER4> <Personal opinion> No example, no About page, anonymous subjective quotes,... Less superlatives and more details would make it look more like a genuine service and less like a scam.

</comment><comment><USER5> I would like to sign up for this service, but I am unwilling to until it shows me examples of what emails I will receive.

</comment><comment><USER6> The quotes on the home page don't have a closing quotation mark, and are not attributed to any people.</comment>


Ask HN: What would you like to hear from failed startup founders? - <AUTHOR> I'm thinking of starting a podcast/site which will interview failed startup founders. What would you like to hear from them that isn't covered in the usual postmortem/5 things I learned failing medium posts? <comment><USER2> That depends... are these people who were later successful? Or just those who failed and quit?

If it's the former, then yes. And I'd like to know "what went wrong, and how I fixed it" and some things along those lines.

If it's the latter... then no thank you. I'll stick to the people who overcame adversity and were successful.

</comment><comment> grif-fin I think these three should cover the story I want to know:

\- Where did the idea come from?

\- What was your ideal expectation after launch?

\- What went wrong? (was it the product or wrong judgment of market demand)

<comment><USER3> \- What would you do differently

\- What did you do differently at your next startup</comment></comment>


101 Startup Failure Post-Mortems - <AUTHOR> http://www.cbinsights.com/blog/startup-failure-post-mortem/

<comment><USER2> I'm not sure if I now how to read a startup failure post-mortem. What am I looking for? Which missteps, if any, are worth extra attention?</comment>


Peachpie vs. PHP microbenchmark - Computing Pi - <AUTHOR> First microbenchmark for the PHP compiler for .NET (Peachpie) is done - calculating Pi. See how Peachpie compares to regular PHP at blog.peachpie.io. <comment><USER2> This is pretty cool but obviously you can optimise a microbenchmark to fit your case perfectly. Is like creating a statistic in your favour because it doesnt tell anything about how speed compares to php7 for example overall. Still interesting implementation but I am skeptic about if you can make a whole application this much faster.

<comment><AUTHOR> Thanks for your comment. You are right about the fact that we obviously heavily optimized specifically for this microbenchmark. However, Peachpie's architecture is designed in such a way that enables us to optimize most processes and features fairly easily. It would be quite surprising if entire applications ran 6x as fast as they would using regular PHP, but it is not inconceivable.</comment></comment>


Ask HN: How does Kotlin compare to Swift? - <AUTHOR> <comment><USER2> They are Italian and French. Or F# and OCaml. Very similar languages: [http://nilhcem.com/swift-is-like-kotlin/](http://nilhcem.com/swift-is-like- kotlin/) The huge difference lies in the underlying platform (JVM vs LLVM) and main deployment target (today Android vs iOS, though this announcement [https://blog.jetbrains.com/kotlin/2017/11/kotlinconf- keynote...](https://blog.jetbrains.com/kotlin/2017/11/kotlinconf-keynote- recap/) shows that Kotlin is expanding its reach fast).</comment>


50% off first month of 37signals products - <AUTHOR> http://twitter.com/37signals/status/1223188014 This should be helpful for a few startups. <comment><AUTHOR> this should be helpful for startups

<comment><USER2> maybe, but it is still an ad.</comment></comment>


If You Are Not Drowning in Demand, You Don't Have Product-Market Fit (2017) - <AUTHOR> http://blog.capitalandgrowth.org/michael-seibel/ <comment><USER2> In 2013 I made a video about how FPGAs could be used to mine Litecoin and other scrypt coins. It was very low effort and I forgot I had uploaded it.

Not only did it get 30,000 views in a month, the stream of emails from interested people was constant. Probably over 200 emails from people who wanted to buy a machine from me as if I had created one (I hadn't).

Really interesting stuff. If you truly do make something revolutionary, the demand finds you.</comment>


Study: Showing Students Standout Work Can Backfire - <AUTHOR> http://www.edweek.org/ew/articles/2016/02/17/study-showing-students-standout-work-can-backfire.html <comment><AUTHOR> Abstract of the referenced study: [http://pss.sagepub.com/content/early/2016/01/28/095679761562...](http://pss.sagepub.com/content/early/2016/01/28/0956797615623770.abstract)</comment>


RISC OS and NetBSD running on the same SoC - <AUTHOR> http://www.update.uu.se/~micken/ronetbsd.html <comment><USER2> Here is a forum thread on doing this that looks to be from the same guy (based on screen caps included), but gives a little more detail: [https://www.riscosopen.org/forum/forums/5/topics/15128](https://www.riscosopen.org/forum/forums/5/topics/15128)

</comment><comment><USER3> That's pretty neat. For big/little SOCs, could it benefit security to run something less secure like android/ubports on the big side and something more secure (openbsd?) on the little side?

<comment><USER4> Not sure there is any mechanism to prevent the big core from interfering with the little core (apart from using virtualization or running OpenBSD in TrustZone).

</comment></comment><comment><USER5> "It worked quite well, but I can't really see the meaning on running two [RISC] OSes."

Updates?

For many years I do an update dance with NetBSD kernels. Two kernels with embedded filesystems on same bootable media, one updated, one not. Select kernel at boot, download appropriate userland to RAM disk then chroot. Download new kernel source, compile, repeat.

</comment><comment><USER6> Neat, I've done something like this to run a couple different RTOS images on an SoC before. For a long time, this was sel4's only way to run on multiple cores as well.

I've also seen people run Linux on some cores, and real RTOSes on other cores as well, even in cases where the cores are more or less symmetric.

</comment><comment><USER7> It would nice for the era of multicore to be able to do this on PC. Run Windows on 4 cores and Linux on 4 cores while being able to share the rest of the hardware.

It probably would be impossible but nice.

</comment><comment><USER8> No publication date on the site, but it seems like it was published today.</comment>


Review and Teardown of a Cheap GPS Jammer - <AUTHOR> http://phasenoise.livejournal.com/2017/11/3185.html <comment><USER2> The article mentions the incident around Newark Airport where a truck driver using a GPS jammer was interfering with air traffic. Here's an article from a local source if you're interested in the details; he was fined $32k: [http://www.nj.com/news/index.ssf/2013/08/man_fined_32000_for...](http://www.nj.com/news/index.ssf/2013/08/man_fined_32000_for_blocking_newark_airport_tracking_system.html)

<comment><USER3> The actual enforcement action notice is at the link below. The FCC does _not_ mess around. They started at $42k, but were 'nice' and offered him a 25% discount because he voluntarily relinquished the jammer.

[https://apps.fcc.gov/edocs_public/attachmatch/FCC-13-106A1.p...](https://apps.fcc.gov/edocs_public/attachmatch/FCC-13-106A1.pdf)

<comment><USER4> He couldn't pay it all, so the FCC settled for $2,360, paid in installments:

[https://apps.fcc.gov/edocs_public/attachmatch/DA-16-184A1.pd...](https://apps.fcc.gov/edocs_public/attachmatch/DA-16-184A1.pdf)

<comment><USER5> Not as bad as healthcare /s

</comment></comment></comment></comment><comment><USER6> It doesn't go too far in depth; basically it says it's got a signal generator and an amplifier and it should work in a 30 meter radius, give or take.

OTOH, short and to the point, nothing wrong with that. It also (importantly) notes there's no jamming on other frequencies.

<comment><USER7> There's not much more going on with a physical layer jammer. That's all this jammer does. It jams the GPS carrier band so that a receiver can't "hear" the satellites.

You can put together such a jammer from a lab signal generator and a microwave power amplifier that can cover in the GPS band. You may have to tweak the signal generator to get a suitable wide signal. GPS is not a narrow, but a wide-band signal. This helps receivers to reject narrow interference.

</comment></comment><comment><USER8> See also: [https://arstechnica.com/information- technology/2017/11/austr...](https://arstechnica.com/information- technology/2017/11/australian-man-uses-snack-bags-as-faraday-cage-to-block- tracking-by-employer/)

</comment><comment><USER9> GPS jamming is a good way to have men in black show up at your doorstep. Source: a friend.

<comment><USER10> +1 to this.

Men showed up at my doorstep... I removed the designs from github and they went away happy.

No fine or anything, but it was clear I didn't have a choice...

</comment></comment><comment><USER11> So is anyone making one that emits on all (or some useful subset of) the frequencies a modern smartphone uses, has a ~30mm range and is powered by the phone?

The Chinese could crank these out and have the to your door $3.99USD.

<comment><USER12> They were selling these online from shady resellers at least ten years ago. A friend picked one up and told me he could jam some phone calls on the train, depending on carrier and frequencies used I suppose. I think it broke a week or two later and he tossed it.

Second link from google:

[http://www.jammerfromchina.com/categories/Mobile_Phone_Jamme...](http://www.jammerfromchina.com/categories/Mobile_Phone_Jammers/)

</comment></comment><comment><USER13> > When using GPS receivers in city urban canyons with tall buildings, the > shadowing and multi-path effects results in poor GPS signal reception and > jammer range can be even hundreds of meters at street level.

That was something that I haven't thought off. The jammer will have less interference from shadowing and will benefit from reflection of buildings, so in a city environment it interferes more than in open air.

<comment><USER14> Pretty much. Here's an expanded, but still very simple way to think of the way this noise jamming works:

\- A GPS receiver needs a signal/noise ratio above X dB to get a lock

\- Higher gain antennas, more sensitive receivers, and higher powered signals add to the numerator (good)

\- Antennas with smaller sidelobes (often a consequence of a high gain antenna or nulling antennas), and better signal processing reduce the denominator (good)

\- There is a pretty good S/N margin when using a modern receiver with a good antenna in open space

\- Shadowing reduces the signal strength and thus reduces the numerator (bad)

\- Multipath effects increase noise, and thus increases the denominator (bad)

\- Jamming increases noise, and thus increases the denominator (bad)

\- Jamming can be improved by cranking up tx power or using a higher gain antenna (or both)

\- In open space, a jammer must overcome the entire S/N margin by itself. GPS systems are so highly optimized (very good algorithms) and have such a big S/N margin that you can often get a lock just by putting the GPS in a hole and that nulls enough of the jamming.

\- In a city, shadowing and multipath eat into the S/N margin by quite a bit, so the jammer doesn't have to do as much. Sometimes the urban environment is so bad that GPS can't get a lock even without a jammer.

\- Jamming strength decreases with the square of the distance (or 2x when talking in terms of dB, which are logarithmic)

\- The margin reduction by the shadowing and multipath benefit the effective distance by the square of the reduction (or 2x when talking in terms of dB)

\- So any natural jamming benefits the jammer by allowing it to operate much further away or operate at a lower power. There isn't much you can do to reduce natural jamming like multipath or shadowing other than moving to a different location.

edit: grr, I hit tab and enter before finishing.

</comment></comment><comment><USER15> Would have loved a straight on close up of the board. The PCB routing at high frequencies is always interesting to see.

<comment><USER16> You can get a good idea of the signal path to the antenna mounts with the photo provided, especially the photo visible via the underlying link to dx.com. Trace width would be set to match desired impedance (e.g. 50Ohm), generous spacing from adjacent ground plane for isolation, and big radii on corners to minimize self-capacitance. The 45deg component mounting is unusual, especially since the equivalent (?) PCB on dx.com doesn't have it. Perhaps this board was fabbed in low enough volume that optimizing pick & place to only do multiples of 90deg wasn't needed.</comment></comment>


Prosecution recommends sentencing Ross Ulbricht to life in imprisonment [pdf] - <AUTHOR> https://ia801506.us.archive.org/27/items/gov.uscourts.nysd.422824/gov.uscourts.nysd.422824.256.0.pdf <comment><USER2> Technically, they only note that the sentencing guidelines and the probation office are pointing towards a life sentence, but the government itself is only requesting a "lengthy sentence", "above the minimum" (which seems to be 20 years).</comment>


Run Your Jekyll Site on Heroku - <AUTHOR> http://mwmanning.com/2011/11/29/Run-Your-Jekyll-Site-On-Heroku.html

<comment><AUTHOR> This post covers 2 methods of running your Jekyll site on Heroku without the messiness of having to check your '_site' build directory into git.</comment>