The third largest stock exchange in America is a startup - <AUTHOR> http://www.newsweek.com/id/158587/

<comment><USER3> BATS does not only compete on price and speed. It offers many unique order types tailored to it's main market - high speed traders. Targeting high speed traders gave BATS an advantage because those are the customers that make exchanges money - both because of volume, and the specific types of orders they use. High speed traders traditionally try to avoid the automated routing that traditional orders go through to match and fill. A high speed trader would like to know the fees with certainty, and routing opens up the risk of unexpected fees. Therefore, many high speed traders mark their trades for no routing. This benefits the exchanges since the liquidity stays on their exchange and they will collect the fees when/if it fills.

</comment><comment><USER4> Base upon their job description, looks like their messaging platform is built on C++ and then they want some Python... [http://www.batstrading.com/resources/employment/bats_trading...](http://www.batstrading.com/resources/employment/bats_trading_job_description_software_developer_kc.pdf)

<comment><USER5> Parts of it are in PHP too. Not sure which parts, I never got hired there, but they were hiring for PHP about a year ago.

</comment></comment><comment><USER6> It's a fine example of B2B startup.

</comment><comment><USER7> Stock exchanges the way they are right now have no real right to existence any more anyway. All the trading could be direct between buyers and sellers using a fairly simple web interface.

No more people picking up on the 'buzz' and trading on their own account either that way.

Of course that would remove all the fee structures that have been created over the years.

I doubt it will happen though.

<comment><USER3> I am not sure you understand - BATS is an ECN, not an exchange. In fact, most trading is on ECNs nowadays. An ECN is basically what you describe - <USER2> a web application (usually using a protocol called FIX) that matches buyers with sellers.

Of course they charge a fee - there is a cost to running the data centers and ensuring regulatory compliance.

See: [http://en.wikipedia.org/wiki/Electronic_Communication_Networ...](http://en.wikipedia.org/wiki/Electronic_Communication_Network)

<comment><USER8> BATS _is_ a Reg-NMS protected exchange on par with Nasdaq, Arca, NYSE and all the others.</comment></comment></comment>


Motivation Over Discipline - <AUTHOR> https://www.artofmanliness.com/articles/motivation-over-discipline/ <comment><USER2> I like this article, but that's because it's confirming thoughts I've had myself. The main idea behind the article is that disciplined people usually just like doing the things they do, rather than forcing themselves to do them. You stumble on this same idea when you look into ADHD. People with ADHD have trouble doing things they're not interested in, but they can sit down and spend hours upon hours on something that does interest them.</comment>


Ask YC: Do any of you primarily target women? - <AUTHOR>

The other day I was launching a piece of linkbait to promote my software.  I tried promoting it through a campaign on Stumbleupon, which lets you show the advertisement only to certain demographics.  This made me practically scream with joy -- I immediately restricted it to 25-99 year old ladies.
Then I realized "Wow, that is probably pretty rare for software companies".  But that is, judging by customer contacts and names on orders and credit cards, about 95% of my business.
Anybody else here in my situation?  Got any tips, tricks, etc? <comment><USER2> Laughing too hard to read beyond the title. Yes, I primarily target women.

</comment><comment><USER3> I'm assuming from your profile, that your bingo card creator is what we're talking about and have to say that I find this discovery fascinating, but am not surprised. When ABC ran it's Primetime Bingo TV show last season, my wife was printing like 30 cards to follow along from home. She loved it. And, not for the chance to "win fantastic prizes" either (1. Math Degree, so she knows the Odds; 2. The "everybody wins" prizes were like $5 gift cards if I remember).

I would have guessed that "Married with Children" just made up the Peggy Bundy _loves_ Bingo part of the story, but no--Girls apparently dig Bingo.

</comment><comment><USER4> I've got a startup in the works that will lean a bit towards the female demographic.

Facebook ads allow you to target specific genders and age ranges.

It shouldn't be too hard to find the top web properties among women.</comment>


Ask HN: Paying Overseas Employees - <AUTHOR>

Hello, HN!
Today, I hired my first employee! The problem we've encountered is that he's in Europe and I'm in the US and that European banks want to charge massive fees to process US cheques. Is anybody here in a similar situation? What's the best way to go about doing this. Paypal seems like one option, but it seems very unprofessional and I don't trust them very much.
Would very much appreciate your input! M <comment><USER2> I've had a similar situation (Canada to South Africa) and at the time the best thing was to go in to the bank to do a wire (swift) transfer.

There are various options; eg what currency you want to send the funds in (ie who bears the currency risk), and on what side the charges are paid.

There are still some overheads this way, so we found it most practical to pay 2 months at a time and do the wire every other month.

You can also try finding out about the cost of you just drawing a banker's draft on your bank directly in the foreign currency.

</comment><comment><USER3> I've received international payments before from clients using Paypal, Moneybookers and Western Union as well as direct bank transfer.

Mostly, the direct bank transfer was the easiest. I paid $30 as a transaction charge.

Paypal is not supported in my country so that money is stuck in paypal and i can only use it online. But Moneybookers supports bank transfers and it is much easier to deal with in my country.

This is all relative of course. Larger companies for example will already have a process in place for bank transfers, while smaller ones or individuals will prefer something like Paypal.

</comment><comment><USER4> I have a USD denominated checking account with Citibank UK, any EU citizen can open one, and there are no fees for paying in USD cheques.

I also have a US bank account with Chase. I'm an EU citizen. I just walked into a branch in Midtown Manhattan and said I needed an account to receive approximately $10,000 per month and suddenly the need for a US passport, SSN, etc evaporated. YMMV.

</comment><comment><USER5> Use XE Trade. Get his bank information and transfer the money directly into his bank account.</comment>


Bicycle Helmet Ratings - <AUTHOR> https://www.helmet.beam.vt.edu/bicycle-helmet-ratings.html <comment><USER2> > A lower score offers better protection.

I don't understand why anyone would present the data like this, sure, 'lower is better' makes sense in benchmarks where you're presenting a raw timing or such, but with an arbitary unit like 'score' just invert the data so bigger -> better and let people's human nature take over.

<comment><USER3> Especially when more stars is better! Overall their testing methodology looks good, so it's a little disappointing that the presentation is so counterintuitive.

<comment><USER4> Their primary presentation is the 0-5 star rating which is perfectly intuitive.

If I'm reading the methodology correctly, the actual STAR score represents the incidence of concussion, in which lower is certainly better.

The only real confusing thing I see is the "star" naming of the "STAR evaluation score" vs. using a "star rating" (0-5) and how they are actually separate things.

<comment><USER3> I agree that the stars are clear, I wonder if there's any point in displaying the score at all, given that.

</comment></comment></comment></comment><comment><USER5> Note for those looking for this helmet, from [1]:

"Footnote, May 30 2019:We have since received word that the Cyclone MIPS is an older model that has been discontinued by Lazer – and suspect, given the likely spike in interest as a result of the Virginia Tech update, that the brand may be regretting that decision."

This is particularly unfortunate, since the scores for two Lazer MIPS helmets vary quite widely on the test in question, so it's not clear you could just go with another model.

[1] [https://cyclingtips.com/2019/05/wavecel-vs-mips-virginia- tec...](https://cyclingtips.com/2019/05/wavecel-vs-mips-virginia-tech-safety- test-rankings/)

</comment><comment><USER6> I think the key take-aways are:

* any helmet provides significant protection vs. not wearing a helmet

* there is no correlation between cost and protection level

* there may be a correlation between protection and rotational-focused technologies (i.e. MIPS et al) but it's hard to tell because most manufacturers don't have a non-MIPS product anymore (where they do I don't see both the MIPS and non-MIPS models here)

</comment><comment><USER7> I have a Giro Synthe MIPS, and I would avoid them: they designed the sweatband wrong, so that it all drains right down into your eyes.

It bugged me so much I got a Bell helmet that has a little tab that takes the sweat out away from your face so it can drip down unimpeded. It looks kind of gimmicky, but it works pretty well.

<comment><USER6> Have you tried a Halo band? Sounds somewhat similar... it's a neoprene headband with a rubber squeege-like trough on the inside. It channels the sweat back behind your ears and down your neck.

They are awesome and when I ride without one I always regret it. Well worth the 15-ish bucks and vastly superior to extra padding or a bandana.

They make a visor and hat for runners but not as impactful as the headband. Highly recommend!

</comment></comment><comment><USER8> Helmet technology made an important leap in the last few years by adding protection against rotational forces. If you are in the market for a helmet, consider getting the MIPS version (or Bontrager's Wavecell). MIPS costs only slightly more than the same helmet without it.

<comment><USER9> Having been in oddly many very different bicycle accidents of varying levels of catastrophe, I have a hard time believing that rotational forces are a real problem and not something made up by marketers trying to sell a new widget. Helmets are approximately half-spheres which bounce and skid. Protruding elements like visors are made to break away with minimal force so that nothing can catch. The contact surface is small and the external shell is hard and slick. So where is the rotational force coming from?

If you watch the video at [https://mipsprotection.com](https://mipsprotection.com) their test scenario is the most bonkers forced thing I've ever seen. Their idea of a collision is where you are completely upside down with your feet are straight up in the air and your head straight down and you're falling onto a 45 degree incline. Screenshot: [https://imgur.com/kIFN1ds](https://imgur.com/kIFN1ds)

And besides all of that, the MIPS people talk about "10-15mm relative motion". It's hard to imagine that any random bike helmet strapped to any random head doesn't already give 10-15mm of relative motion even without MIPS.

</comment></comment><comment><USER10> The 'score' value is a bit counterintuitive and offers no further explanation past:

> A lower score offers better protection.</comment>


Authorize.net: MasterCard and Discover are modifying their rules - <AUTHOR> http://www.authorize.net/support/pafaqs/

<comment><USER2> Pretty big change -- we were surprised we hadn't heard of it before. MasterCard support is only required for certain merchant codes though, whereas Discover has it required for all.

</comment><comment><USER3> Good move for Discover, making it harder to support one of the least popular card types. Real smart business move.</comment>


Asm.js performance closing in on GCC (Android and Desktop) - <AUTHOR> http://multimedia.cx/eggs/playing-with-emscripten-and-asm-js/

<comment><USER2> This reminds me of my "conversion" from non-believer to believer nearly 2 years ago: [http://flohofwoe.blogspot.de/2012/10/mea- culpa.html](http://flohofwoe.blogspot.de/2012/10/mea-culpa.html)

I don't quite understand the "Implications for Development" part at the end though, emscripten provides a very standard GCC style toolchain, so it's relatively easy to get makefile-based projects compiled (personally I prefer cmake since it also generates IDE project files). The output of emscripten isn't meant to be maintained, instead it should be treated like compiled binary code, and recompiled from their C/C++ sources. There's no really useful interactive debugging (although there is support for source-maps), but I usually just debug a native desktop version of a project in Xcode or VisualStudio. For emscripten platform-specific bugs the generated (non- minified) JS code is actually quite readable.

Finally, I had much less problems porting my code and build system to emscripten then to Android's NDK. And if the code is already running on Native Client, an emscripten port should be relative easy, because (apart from missing pthreads support in emscripten), the limitations of running in a browser environment are quite similar.

</comment><comment><USER3> and speed vs libjpeg-turbo? please? [disappointed to see I couldn't actually post comments on the site itself]</comment>


Computer Scientists Show That Mass Incarceration Is Contagious - <AUTHOR> http://www.fastcoexist.com/3032447/computer-scientists-show-that-mass-incarceration-is-contagious

<comment><USER2> Crime rates tend to be higher around police stations, military bases, and airports. Not because of a higher rate of people committing actual crimes but simply because of the increased police presence.

All it takes is an ambitious cop who doesn't want to leave his advancement to chance. Once you're in the system it's difficult/impossible to get out.

I grew up in a pretty nice area and rarely had encounters with the police unless I was doing something stupid and deserving of their attention. Even then, I was treated with decency and respect.

I didn't understand the difference until I moved to an area that was close to a large police station and courthouse. There was no doubt about the increased police presence.

One day on my way to work on my motorcycle I got pulled over by the CHP (California Highway Patrol). When I went to hand over my license/registration/insurance the officer reached over and snatched the keys out of my ignition. Instead of telling me what I was being charged he started with a threat, "you will cooperate or I'm going to tow your bike and haul you off to jail." I was completely shocked by his escalation of force because leading up to this I had no clue why I was being pulled over. I wasn't driving fast, aggressive, or recklessly.

It turns out that California passed some wonky law a month prior that any muffler louder than stock (guess that gives Harleys a free pass) is illegal. I don't run an aftermarket muffler so he couldn't charge me. He tried his best to convince me that I was in the wrong but by then I had shrugged off the initial shock and wasn't going to admit to an offense I didn't commit.

He couldn't pin me with the charge he pulled me over for. So, he held me there on the side of the road for 20 minutes antagonizing me and asking personal questions that had nothing to do with being pulled over. It was clear as day that I wasn't going to be let go until either he could find another reason to charge me or he I'd snap and give him one.

Meanwhile, I did nothing out of the ordinary beside driving past a corrupt cop who was looking to bump the statistics on a new law and probably earn some brownie points with his boss.

As soon as my lease was up I moved the hell away from that area and try my best to avoid/evade the CHP when I see them.

I'm not saying all cops are bad. Escalation of force and violence are tools of their trade because violent criminals often don't respond to anything else. The problem is, there is no incentive for them to hold back. Performance is measured by arrests and charges regardless of 'actual' crime. Anybody who has worked for the US Govt knows that the survival of any government organization is based on perceived performance measurements, whether or not they serve the greater good.

It's not much of a mystery why kids who grow up and get out of bad neighborhoods are usually the type who spend most of their childhood indoors reading, studying, or playing with a computer. The concept of 'guilty by association' is common knowledge but the less understood one should be 'guilty by proximity'.</comment>


iRobot Terra Robot Lawn Mower – First Impressions - <AUTHOR> https://myrobotmower.com/irobot-terra-robot-lawn-mower/ <comment><USER2> By first impressions, I thought this was a hands-on impression. Sad to read that its just reiterating whats been announced a couple months back.

<comment><USER3> And posts like these make it hard to trust any of the "review" sites out there when all they do is rehash press releases.

<comment><USER4> They admittedly aren't perfect, but Consumer Reports is the only one I remotely trust. So many "review sites" basically just look at the highest rated items on Amazon and create an article out of it. I needed a new beard trimmer recently and it was just page after page of spam.

Amazon reviews are so manipulated they're nearly useless now. Reddit isn't too bad, at least for the most part they are real people.

<comment><USER5> Fwiw about a year ago I got the Peanut, a professional plug-in trimmer that costs $45. It works way better than any battery-powered trimmer I've tried.

Only drawback is that you change the length by replacing the guard instead of just sliding it to a different position; one day I didn't notice the guard was off and with one swipe it was too late to salvage my beard. I removed the rest and started over; luckily I keep it short anyway.

<comment><USER6> Corded products are underrated. It's a hassle to deal with the cord, but it's worth it when not needing to worry about if the battery is charged when you start, the battery running out mid-task, or plugging in the battery to charge after and remembering to unplug it later.

The issue with the cord can be greatly improved by having a nice retractible extension cord. Easy to take out, easy to put back, easy to move, easy to store.

</comment></comment></comment></comment></comment><comment><USER7> This article doesn't have a date, but it must be at least a little old. It says:

> _iRobot has finally announced that it will launch the Terra robot lawn mower > later in 2019_

Looks like iRobot's announcement was January 30, 2019:

[https://media.irobot.com/2019-01-30-iRobot-R-Reinventing- Law...](https://media.irobot.com/2019-01-30-iRobot-R-Reinventing-Lawn-Care- with-Terra-TM-Robot-Mower)

</comment><comment><USER8> I feel like they missed a golden opportunity to let users select between various space filling curves for the cut pattern.

I, for one, would love to have my lawn cut in a Hilbert Curve pattern.

<comment><USER9> Get one of the mowers that follows a wire and then embed the wire under the grass in the pattern you want.

I remember seeing one of these where a guy would mow outside a pattern at one height, then adjust the height of the mower and mow the inside of the pattern so the grass was longer, giving him a noticeable pattern. Can't find a link at the moment though.

<comment><USER10> > Get one of the mowers that follows a wire and then embed the wire under the > grass in the pattern you want.

> Hilbert Curve pattern

OP is going to be outside for a while depending on the level of precision of that particular "pattern"...

<comment><USER11> > on the level of precision

This is pretty much set by the width of the mower blades - so not a practical issue.

</comment></comment></comment></comment><comment><USER12> > The iRobot Terra will use a series of wireless beacons that you place around > your yard instead of a perimeter wire. These will provide a wireless, > localized positioning signal to allow the iRobot Terra to find it's way > around your lawn.

What happens when the beacons run out of battery power?

The biggest fear I have with a robot lawnmower is that it somehow escapes its boundary and wanders the neighborhood and injures a person or pet with its spinning blade. And it's pointless to have one if you have to supervise it to safeguard against rare faults in its boundary detection system.

<comment><USER13> That's my concern about their home vacuum cleaners as well: if a battery runs out, it would hit my computer. There are some programmable models though (were not available here at the time), and various certainly programmable DIY ones (may be a fun project, but would take some time); that seems like a much better solution -- both for efficiency and predictability (as opposed to random walk), and for this particular case with paths/boundaries (define them once in the robot's memory, maybe even just by moving it manually or otherwise showing it the path/boundaries, and don't rely on batteries in external devices).

<comment><USER14> > if a battery runs out, it would hit my computer.

So? It's a vacuum, you could drive it right in to a computer non-stop until the battery runs out and it's not going to do any meaningful damage. The worst case scenario would be if you had a case where the power or reset button was right there at vacuum height, but other than that what's your concern?

<comment><USER13> Mechanical shocks are indeed the concern.

> you could drive it right in to a computer non-stop until the battery runs > out and it's not going to do any meaningful damage

What is this based on (i.e., are HDDs and all the smaller components commonly designed to withstand such shocks)?

Now I've looked up a random WD Blue HDD data sheet [1], which mentions 30G shock (read/write, 2 ms). If a vacuum cleaner was to hit it directly while moving at about 1 m/s (less than 4 km/h, and it seems to walk at around that speed, though I haven't found exact values), and assuming that it would accelerate the HDD to its own speed in those 2 ms (maybe it's not realistic, though not obvious to me), that'd be about 50G (1 m/s / 0.002 s / 9.8). Even if it is so, a vacuum cleaner has a plastic bumper, a computer case is heavy, and a vacuum won't hit any of those components directly, but it seems dangerously close and I'd rather not hit the computer.

[1] [https://documents.westerndigital.com/content/dam/doc- library...](https://documents.westerndigital.com/content/dam/doc- library/en_us/assets/public/western-digital/product/internal-drives/wd-blue- hdd/data-sheet-wd-blue-pc-hard-drives-2879-771436.pdf)

<comment><USER15> > accelerate the HDD to its own speed in those 2 ms (maybe it's not realistic, > though not obvious to me)

You need to conserve the momentum and kinetic energy, so assuming an elastic collision you're going to accelerate the PC to about half the speed of roomba[1] so you're looking at closer to 25G. With the plastic bumper, you're not getting anywhere near an elastic collision and your contact time is probably a lot longer than .002 due to the deflection. I would not worry too much about this.

[http://www.convertalot.com/elastic_collision_calculator.html](http://www.convertalot.com/elastic_collision_calculator.html)

</comment></comment></comment></comment></comment><comment><USER16> I actually have a few cows of different colours coming to my patch to do the mower. My review of them is that they do the job and so far no residue. Just wonder in the old days there is a buffalo. May be my opening is too small for him or is it her (got horns though). Just to ensure they do not sit down as settle down in front of my house is not a good development for my places.

It is real. I am not joking.

<comment><USER17> > _so far no residue_

I think your cows might be constipated. ;)

Incidentally I've heard of farmers renting out goats to mow difficult terrain, particularly on steep hills next to roads.

</comment></comment><comment><USER18> Has anyone had decent results with these mowers (any brand)? I'm in the process of building a house that's going to have a pretty simple yard and I've considering picking one of these up.

They are also substantially more expensive than the typical electric mowers you push yourself but if it saves x hours per week/month could be worth it. I just don't want to end up with an expensive paperweight and end up having to buy another mower anyways.

<comment><USER19> Consider instead something other than a lawn. They don't call it "green concrete" for nothing.

[https://earther.gizmodo.com/lawns-are-an-ecological- disaster...](https://earther.gizmodo.com/lawns-are-an-ecological- disaster-1826070720)

<comment><USER3> Depends on your climate. In the PNW for example you don't have to water really so having a nice lawn isn't an ecological disaster that the article would make out.

<comment><USER19> Watering, weeding and fertilizing is not the only problems -- there is also intentional lack of biodiversity. Plants native to the area will always support more.

<comment><USER3> Yep, people should use local grasses and clovers. I've let the clover here take over my back yard and it's been wonderful with attracting bees - plus I don't have to mow it very often.

</comment></comment></comment></comment></comment><comment><USER20> It's a good call for iRobot to skip GPS. You can get 1-2cm precision. But not always and it can be hard to tell when you are off. Plus the equipment is still not inexpensive in a consumer product context.

I think if I were to do it over (my lawnmower startup blew up) I'd do something like this and just drive the beacon cost down as much as possible. I had looked at using the DW1000 but the rest of the team wanted something beaconless for commercial applications.

<comment><USER21> I'm not a fan of beacons. If I built this for myself I'd probably stick a calibrated camera or two somewhere and use that for localization. Some day...

</comment></comment><comment><USER22> They mention GPS is not accurate enough and thus different solution is needed.

Could you do local differential-GPS solution? Put the "base station" to charging base (which likely remains static) and transmit the correction information over wifi or using some unlicensed frequency.

<comment><USER20> It could work and that plus an IMU is what we were doing at my now recently defunct lawnmower startup. For us to have the precision we needed we had about a 3500$ setup to do so.

<comment><USER23> Didn't all the jostling of driving over terrain mess with the IMU?

<comment><USER20> Not really, we were using an IMU with a magnetometer and it was reasonably stable when it was setup correctly. As well as calibrated well. That with the GPS made things stable enough that it was at least a very good demo.

<comment><USER23> Very cool!

</comment></comment></comment></comment></comment><comment><USER10> This is pretty neat; I had the impression that they were going to make something like this, but kinda put it out of my mind after hearing nothing about it for years.

I found an old Friendly Robotics lawn mower robot on Craigslist and purchased it for $50, thinking of using it for my lawn but I never got around to doing anything with it. Mainly because I couldn't think of an easy way to detect the perimeter of the lawn without an edge wire!

I guess it's not an easy problem to solve.

I had considered a bunch of options, a few of the ideas I had were:

1\. Some kind of camera or color sensor, looking downward, to detect "green" vs "non-green" \- assuming the grass was green and non-grass would be some other color. That would work ok for most of my yard, but my lawn in front doesn't have an "edge" with the neighbor's lawn - so it would mow their lawn, too - not what I want.

2\. A passive perimeter, consisting of a bunch of spaced (maybe 6" between?) magnets - I thought maybe plastic golf tees with a rare-earth magnet glued on top would be ok; then use hall-effect sensors on the robot's perimeter to determine if it had crossed over the line of magnets.

3\. This one was more to detect cut vs uncut grass - but use some kind of humidity sensor; assuming cut grass has higher humidity than uncut grass, "sniff" the ground and avoid uncut (drier) areas. The problem with this concept, mainly, was in not being able to find high-speed humidity sensors/detectors.

At any rate, I never followed through with any of this, but maybe someday I might return to it? I am curious on the cost of this iRobot lawn mower, though. I'm guessing 4 figures, given what I know about the price of their vacuums (which my wife loves; every time one dies, she buys a new one, and the old one I save for my future Roomba army to take over the world with).

If my guess is accurate, then I'll just have to put off buying one, as it will still be cheaper to continue to pay my landscaper to cut my lawn (and this robot won't trim trees or bushes yet, so...)

</comment><comment><USER24> I fail to understand how a combination of GPS and Machine vision could not overcome the need for a dedicated telemetry system.

I mean yeah if you don't want to build a machine vision system to handle this I guess.... But my John Deere hardware has GPS support for crops and the accuracy is pretty damn spot on.

<comment><USER14> > But my John Deere hardware has GPS support for crops and the accuracy is > pretty damn spot on.

To get that level of accuracy they're using differential GPS where another fairly expensive device is placed at a known location and transmits a signal indicating the amount and direction of the error in the signal received from the satellites. The receiver on the tractor then uses this information to correct the signal and get much greater accuracy than would otherwise be available.

This is not available in consumer-grade receivers.

<comment><USER25> >This is not available in consumer-grade receivers.

not true. i posted a link in a sibling comment but you can use two piksis with one as the base and one as the rover to get sub cm differential rtk. you can also use NOAA CORS station (if you're within 10km) to get precise ppk

[https://www.ngs.noaa.gov/CORS/](https://www.ngs.noaa.gov/CORS/)

for this use case i would set the base down at a fixed location and let it solve. then i would wait a day for CORS data to get accurate gps for the base and plan out my trajectories relative to that base (using whatever registered maps they use). alternatively you could survey the location where the base sits.

</comment></comment></comment><comment><USER26> Almost a year old, nothing newer?

><meta property="article:published_time" content="2019-01-30T22:15:19+00:00" />

</comment><comment><USER27> hopefully they can do something like: [https://www.sawstop.ca/](https://www.sawstop.ca/) to be safer. or maybe the moisture in the grass might send false positives making it not possible. i just fear an old blind/deaf dog getting hurt (or passed out frat boy).

<comment><USER28> Off topic, but kind of funny the first thing you see when opening that is someone missing a finger. I'd think you would want to demonstrate off the bat your product means you keep all 10.

</comment></comment><comment><USER29> spoiler: robot lawnmowers have been around for 20 years. they're somewhat popular in Europe. Ireland has robotmow, and Colorado based bigmow has a lawnmower thats almost as wide as a human is tall.

>One of the key features of the iRobot Terra is that it will not use a perimeter wire to mark the boundary of the lawn.

So the Terra is short for Terra-fying I take it. We havent even built an autonomous automobile that doesnt occasionally mow down an errant jay-walker, yet somehow a bladed autonomous vehicle is going to be safer? At least with Robotmow and competitors you have boundaries. You can run or crawl to safety if there were to be an accident. Nothing in the review seems to indicate theres even the potential for this device to detect a human presence. and a smartphone app? One good hack, and you now have a lawnmower that drives into a pool full of children, or a lawnmower that persistence hunts pets to exhaustion and turns them into gulash while youre at work.

</comment><comment><USER30> I absolutely hate my iRobot vacuum. Constantly getting stuck and does a poor job of actually vacuuming. Not to mention the wireless beacons it requires cost ~1/3 the cost of the actual unit.

<comment><USER31> Just buy a Xiaomi vacuum. Half the price, and no wireless beacons needed to be usable.

It gets stuck as well by default, but I set up a lot of red zones on the app and now it finishes perfectly almost every time.</comment></comment>


A High School Student Building Integrated Circuits - <AUTHOR> https://spectrum.ieee.org/semiconductors/devices/the-high-school-student-whos-building-his-own-integrated-circuits <comment><USER2> Fun times. It is fortunate he has the means to pursue this interest, I would have been so jealous of him when I was in HS!

I wonder what he is using to do metalization. There is the sputtering setup and the etching setup. Some nasty stuff involved in that. You can of course do quite a bit with polysilicon conductors but if he wants to do more useful things (as opposed to 'look it wiggles!' sorts of things) I'm guessing he will need some permits from the city :-). There is a reason nearly all the old fab sites in the bay area coincide with superfund cleanup sites :-(.

<comment><USER3> I worked in small scale fabs back in the day. One and a half inch wafers. It's not nearly as hazardous as you make out, but it does require training in chemistry. I'm a physicist, but I also did a pre-med, so I had the necessary chemistry background to be safe.

Sputtering requires a small amount of high vac equipment - diffusion pump plus LN cold trap is fine. Sputtering titanium plus gold is straightforward and non-toxic. Etching the pattern requires small amount of aqua regia, which is, of course, a strong acid, but can be easily neutralized to non-toxic by- products. Aluminum evaporation and etching is even easier. The complexity and cost comes in four areas: nanoscale features, large wafers, high throughput, and a process that doesn't need professional chemists to perform.

<comment><USER4> Yeah, but doing it without a lab makes it a lot more difficult to do safely and with multiple likely dangerous (toxics, oxidizers, mutagens) byproducts (including the Si dopants) doing it at home is sketchy. Could one person do it in something the size of a garage? Yes, I think 20-40 probably do every year in a university clean room. But building that for a single person is an exercise in both chutzpah and perhaps (toxic) waste. It's a lot more tempting to cut safety corners when you're doing it for the first time, and haven't made THAT mistake yet.

There is a manual for it though (thanks abecedarious).

[http://nanofab.caltech.edu/images/stories/classes/aph9/Aph9_...](http://nanofab.caltech.edu/images/stories/classes/aph9/Aph9_Manual_CurrentVerNov2014.pdf)

<comment><USER3> Absolutely right. This isn't something anyone should even contemplate in the kitchen! If they are thinking about it, then they don't know what they don't know. Experience in chemistry is needed, and that's unfortunately a lot rarer now in the US than it was 50 years ago. People (and governments) have developed a (mostly unwarranted) fear of it.

The minimum processing requirement (aside from the furnaces and metallizing equipment etc.) is a polyethylene sink hood with at least 100 ft per min flow and a neutralizing tank connected to the drain line, along with fume exhausted chemical storage below. If you can't acquire or build that, you shouldn't proceed further. I did a lot of commercial work in a three foot hood with a large Corning hotplate.

You also need an arrangement to recycle your organic solvents.

<comment><USER5> People are not this dumb- they have come to associate large scale chemical (aka chemistry) processing with environment and health issues- and although nobody in the various industries likes to hear it- they are usually right. Every city has some paved over "dead" zone from the 50s and 60s, before we learned to offshore the burden to third world countrys.

</comment></comment></comment></comment></comment><comment><USER6> Not to be a grinch, but I followed a lot of his videos, and I think he has not yet actually put 2 transistors on the same die, it's the technological threshold for an IC. I think he is working on making patterns (and that's interesting, because nobody is working on cheap masking), he made some individual transistors with masking tape, but not combined yet.

But his videos are very cool, and I'm looking forwards to more. I didn't realize he was that young.

<comment><USER7> >> nobody is working on cheap masking

There's maskless lithography, which is cheap, as far as those things go: [https://en.wikipedia.org/wiki/Maskless_lithography](https://en.wikipedia.org/wiki/Maskless_lithography)

</comment></comment><comment><USER8> Caltech had a freshman course like this in the mid-80s, using a homebrew low- tech process. The dire warnings about hydrofluoric acid have stuck with me ever since. It was fun to try to lay out your gate to take as little area as possible -- fun you can revisit at [http://www.zachtronics.com/kohctpyktop- engineer-of-the-peopl...](http://www.zachtronics.com/kohctpyktop-engineer-of- the-people/)

I was 17 at the time too, but doing it on your own is something else.

<comment><USER4> APh9 -a great class. Of course you can still buy HF chrome cleaner in a spray bottle! [https://hpd.nlm.nih.gov/cgi- bin/household/brands?tbl=brands&...](https://hpd.nlm.nih.gov/cgi- bin/household/brands?tbl=brands&id=22001046)

It doesn't look as strong as the 2% solution PepBoys used to sell, though.

<comment><USER9> I think some rust removers also contain HF.

<comment><USER10> Yep, Whink brand rust remover is 4% HF. It's a somewhat useful source of hydrofluoric acid in a pinch. I recall a procedure for making uranium tetrafluoride from uranium trioxide (which in turn was extracted from uranium ore) using that brand of rust remover as the acidic fluoride source.

</comment></comment></comment></comment><comment><USER11> This is the guy who gave me the incentive to buy a SEM off of govt. surplus for my lab.

Very nice to see that the ieee is finally writing about his PCB fab setup!

<comment><USER12> Where'd you get the SEM from?

</comment></comment><comment><USER13> I guessed correctly that he was inspired by Jeri Ellsworth, and that the article would mention her too. Great to see he went beyond what she did, and although trying to clone a whole 4004 might seem far-off, it's really a matter of replication once smaller structures can be made.

Furthermore, Intel actually released the mask set for the 4004 many years ago: [http://www.4004.com/mcs4-masks-schematics- sim.html](http://www.4004.com/mcs4-masks-schematics-sim.html)

Another relatively "simple" early microprocessor that might be doable is a 6502, it also has the (reverse-engineered) mask layers available: [http://visual6502.org/images/6502/index.html](http://visual6502.org/images/6502/index.html)

</comment><comment><USER14> I wonder if he could make something like the totally unobtainable Curtis filter chips, or other devices which are long out of production but still desirable? I'd think there would be a business in there if it is doable at a sane price. Obviously I have no idea how complex the internals of such a chip are - is an 'analogue' chip significantly different internally to the CPU talked about in the article?

<comment><USER15> In general, analog chips are easier to fab because less transistors are involved and thus minimum feature size isn't as important. Typical parts have merely a handful of transistors.

Cutting-edge analog ICs are a different beast, though. Tightly controlled processes are the norm and post-fab trimming is common.

<comment><USER16> I've always heard that analog is harder because you need to characterize the full behavior of the transistor as opposed to just setup and hold times for digital.

Then again I only tinker with discrete components so it's an area that's somewhat foreign to me.

<comment><USER15> It all depends on what you are trying to do. Some good analog parts use a BiCMOS process with both BJTs and FETs, which is exotic and complicated. The margins of any process are usually complicated, though. Just look at how many billions it takes to develop a cutting edge digital process.

In my opninion it would be easier to do interesting analog parts in a home lab than an interesting digital part. Making an opamp would be easier than a processor and more interesting than an XOR gate (around same # of transistors). Also, you can do some analog stuff with only NMOS or PMOS, which simplifies things by at least 50% compared to CMOS.

For a home lab, you care about process and characterization, but variation isn't as much of a concern because you won't be making that many. Also, just look at the development of the semiconductor industry. Early factories (making analog parts) didn't look that much different from what you could cobble together in a garage. By the time they were doing integrated processors, things were a lot more high-tech.

</comment></comment></comment></comment><comment><USER17> Wasn't surprised to see it was one of Jeri Ellsworth's videos that inspired him. The production quality of her videos seem stuck in the early 90s but the actual content is top notch inspiration. She has a great one on the importance of failure that anyone struggling with not being perfect could benefit from. Nice to see younger folks getting value from her sharing.

</comment><comment><USER18> I have worried for years that budding electronics folks don't get an opportunity to tinker any more, now that everything is integrated. Apparently I need not have worried.... Godspeed to this new generation.

</comment><comment><USER19> Super cool!

He should work with a lab like SNF/ANFF to make more advanced devices, you should be able to get access to one of the Raith E-beam machines for an acceptable price.

<comment><USER20> E-beam litho is...uh...not cheap. The system in the shared fab I use (WNF) costs around $450/hr with various discounts applied. Also, you're not going to get much done in just an hour. Now, maskless laser lithography is reasonably cheap...

However, you can get reasonable quality masks for $150ish, and if you don't care about wafer yield, you can fit all of the layers on one mask. It's 1970s tech - 1:1 contact exposure, but you can hit a few microns.

<comment><USER19> Fair enough, I guess we have different ideas of what cheap is, $4500 for a small prototype is fair enough for me (especially considering there's no other way to get ~50nm lithographic resolution), but on the other I run a funded company, so I suppose the story is different.

</comment></comment></comment><comment><USER21> Very cool. There's one way to make sure that you're not getting any free 'riders' on your Silicon though it will be quite a while by the looks of it before he'll be able to make a CPU that can do useful work outside of small embedded projects by todays standards.

Wonder how he deals with the various solvents required as well, Silicon wafer production is notoriously dirty.

<comment><USER22> Phosphene gas to dope P-type Silicon is also extremely deadly. People have died changing empty tanks of Phosphene gas.

<comment><USER23> links please

<comment><USER21> [https://www.google.com/search?q=phosphene+gas+msds](https://www.google.com/search?q=phosphene+gas+msds)

</comment></comment></comment></comment><comment><USER24> I have really wanted to do this myself. Buy some older fab equipment, and produce NAND chips. Start selling 4TB SSDs for $100 or so. It's ridiculous how long the price-fixing in the SSD industry has been permitted to persist, and someone needs to take them out. We don't need even 10nm production for SSDs or anything. Go ahead and fill a standard 3.5" drive cage with the device. Since the chips function mostly in-parallel, you get speed increases just from concurrent use. And I'd imagine you might find a subversive company willing to sell you controller logic on the cheap. Just so absurd that such a basic part as NAND chips can even get treated like a premium item despite being in basically every product of any kind created in the past 10 years. Any other component like that is commoditized and dirt cheap, especially when they contain no rare materials.

</comment><comment><USER25> This. Is. Awesome. Also, horribly frightening, if you've ever worked in old fabs, they had some extraordinarily toxic stuff. My brain is torn in two trying to figure out if I should cheer or shriek in fright. It reminds me of the story of the kid who made a nuclear reactor.

<comment><USER26> Here's the guy: [https://en.wikipedia.org/wiki/David_Hahn](https://en.wikipedia.org/wiki/David_Hahn) His smug shot looks like he's been too close to the reactor. Looks worse than deadpool.

<comment><USER27> Years of radiation exposure and the poor guy dies of alcohol poisoning. 'Murica.

<comment><USER28> > dies of alcohol poisoning

Cause of death was fentanyl. Earlier comment: [https://news.ycombinator.com/item?id=15470983](https://news.ycombinator.com/item?id=15470983)

</comment></comment></comment></comment><comment><USER29> Does anyone have a single, basic book recommendation that would describe chip fab all in one place?

Also, it seems to me he or people like him should try to make microcontrollers rather than "full" computer chips. I would buy something to drive blinky lights for $5.00 that ran 1/5 as fast as an Atmel chip to support a free chipmaking movement, but I can't see doing something for a general purpose computer chip (with the same ratios at least).

<comment><USER30> If you take a look at the circuitry on some recent cheap multi-mode blinky lights you can find a likely analog IC fabricated right there on the surface of the small PCB and covered with a drop of epoxy, along with a few discrete components and battery holder.

I found a more advanced digital application where the memory modules on our automatic titrator's exchangeable burets are fabricated on about a 5x20mm ceramic substrate and covered with the epoxy droplet with only the gold-plated connector pads showing. Only a limited byte capacity is needed, enough to contain the serial number and a line of variable text to store a couple user variables.

Small feature size and physical chips off of a multi-IC silicon wafer are not exactly essential for such a simple application.

</comment></comment><comment><USER31> My high school didnt even offer drivers ed, couldnt have a football team because of drive-by shootings, shop class wasnt an option after my freshman year (or metal shop) because of a fight that occurred, there were no opportunities for this when I was coming up.

This is something high schools need to be investing in, literally this is what is fueling our future, I think it's amazing, good job.

<comment><USER9> I'm going to disagree. It is really interesting but I think the amount of equipment, space and potentially dangerous chemicals (requiring extensive supervision for high schoolers) and the associated PPE and proper infrastructure to work safely aren't the best use of money/space for a high school. Old equipment also requires a lot of maintenance to keep running. You can learn about these things from a book, watching a plasma etcher or CVD furnace run isn't exactly very exciting after all. Might be worth doing a few of the simple processes but you need so much equipment to do the whole process. The lithography approach mentioned is interesting and could be cool in an undergrad/high school setting.

<comment><USER3> Right. A shared fab run is better: many designs are merged on one wafer, and the resulting chips are packaged and returned to the designers. The cost is split, each designer gets only a few chips per run. Right now, the turn-around time is lengthy, but, like PCB fab these days, that could change.

</comment></comment></comment><comment><USER23> props to him and his parents for supporting this. Hope this story will inspire other kids. Personally i'm inspired, adding this to my "bucket list" of satisfying things to do when i will have time (someday...i hope...)

</comment><comment><USER32> Interesting, how open are IC designs? And what software do they use create complex circuits?

</comment><comment><USER33> I met him at the New York Maker Faire. Pretty awesome stuff he's doing!

</comment><comment> finance-geek Dont end up like this unfortunate boy: [https://en.wikipedia.org/wiki/Ahmed_Mohamed_clock_incident](https://en.wikipedia.org/wiki/Ahmed_Mohamed_clock_incident)

<comment><USER34> You mean the kid who disassembled a clock radio, intentionally made it look like a bomb in a suitcase, used it as a distractant in multiple classes, eventually got appropraitely disciplined for it, but then got tons of free stuff, scholarships from universities, free money and swag, and personally invited to White House by the President?

Yeah, heaven forbid anyone be treated that poorly.

<comment><USER35> Woah, I've never heard the story told like _that_. Could you link me to an article or something? If true that's pretty depressing, I've seen a lot of kids randomly blessed by corporate PR teams that want to look like they're supporting education but I thought at least that story was true. (It's not hard to make a clock and electronics in public places have caused a silly bomb scare before...)

<comment><USER34> It's mostly explained that way on the Wikipedia article, if you read between the lines a bit.

His sister was also suspended from school for a bomb threat, so it seems to be a sort of recurring pattern with his family.</comment></comment></comment></comment>


A Vigilante Fighting Engine Exhaust - <AUTHOR> https://www.newyorker.com/magazine/2018/07/30/the-vigilante-fighting-engine-exhaust <comment><USER2> +1 for this guy. as an engine mechanic my third most common question is "can you get my car to pass a smog check??"

And the answer is usually, "maybe." So many cars are just behind on the maintenance that one expensive checkup is all it takes before they pass and become slightly less noxious on the road.

The biggest, most infuriating thing for me however is professional drivers / truckers that insist upon idling because "WELL the sticker says its CALIFORNIA clean idle certified!" That doesnt mean people wont hate you for filling the streets with diesel fumes while you finish your lunch.

<comment><USER3> >The biggest, most infuriating thing for me however is professional drivers / truckers that insist upon idling

Why would they do that? Isn't that just a waste of fuel? I know some people do that in extremely cold climates because they won't get the engine to start again otherwise, but I would guess unless you're in Alaska that shouldn't be an issue.

<comment><USER4> Idling for more than sixty seconds is illegal here in Norway. Of course not many people are prosecuted for it. And as for not getting the engine started again, well that might have been a problem fifty years ago but in all my more than three decades in Norway I have not had any trouble starting a car in the cold except when I have left the car unused for weeks so that the battery is low.

Perhaps you are right about Alaska though, much colder there.

</comment></comment></comment><comment><USER5> Exhaust particulates are the absolute worst as far as city dwelling. I had a balcony overlooking a boulevard in Paris. I would have to clean it every week from the diesel particulates that settled there. One time, after we went on holiday, I came back and tried to clean it and just gave up. It was so thick it filled 3 dust pans. After that I just locked the glass door and never went out there again.

Then I thought about how much of that junk is making its way into my lungs.

The city of Paris has only recently started to take any action on it. One was to ban trucks of a certain age. But now everyone is requesting waivers because they can't meet deliveries in the city.

<comment><USER6> This is one big advantage the US has over Europe: for the most part, only trucks/buses have diesel engines. Gasoline engines don't produce all the particulate pollution that diesel engines do, and Europe made a big mistake by adopting diesel for passenger cars. As a result, our city air is much cleaner.

<comment><USER7> > Gasoline engines don't produce all the particulate pollution that diesel > engines do

With injection engines this simply isn't true any more.

> made a big mistake by adopting diesel

The small injection turbo diesel engines offered much higher efficiency and thus much lower CO2 emissions (~half) compared to contemporary gasoline engines (they still do). Other parts of the emissions profile (e.g. NOx) have almost exclusively to do with how efficient the engine is run, e.g. gas engines that are close to efficiency to diesel engines will produce similar amounts of NOx.

Broadly speaking, as more aspects of the combustion are externally, forcibly controlled, differences between diesel and gas engines become a lot less.

(The average German car has a 1.6 liter three or four cylinder engine doing something like 4.5l/100km ~ 50 mpg; basically no one is driving big cars with six or eight cylinder engines).

<comment><USER8> The biggest mistake in all of this isn't even diesel vs gasoline, it's that the majority of engine and technology advancements have gone into making cars even more ridiculously powerful and oversize. If a fully loaded van can clear a 10% incline alpine pass with a mere 60 kW engine, there is no justification whatsoever to have any more than half that power in a car driving in the city, or pretty much all over the place.

Gasoline vs diesel feels a bit like fructose syrup vs table sugar, it's pretty clear in both the US and Europe that regulations have not kept up enough of a downward slope on emissions to prevent technological advancement from going into grotesque growths like the SUV instead of cleaning up the exhaust and reducing consumption further.

<comment><USER9> And when the drunk driver of a 10-seat family van plows into you at high speed, do you want your "compact car" to become a "compacted car" with you inside?

Personally, I don't believe my life is quite worth the money I'd have saved by driving a small sedan instead of the larger vehicle I drive.

(If it were, then I daresay my budget would be severely lopsided. Seriously; what kind of idiot would I have to be to spend more than 70% of my net income to car-related expenses?)

<comment><USER10> A pickup or SUV isn't needed to stay safe - especially not when all other cars are compact.

This reasoning reminds me of the tragedy of the commons.

<comment><USER11> This is totally tragedy of the commons reasoning. There exist big cars on the road, so I need a bigger one to protect myself against them. I'm half- surprised that no one is selling civilian-use APCs at this point.

<comment><USER9> Pfft. I couldn't weave, pass and lanechange through the usual shitty traffic if my vehicle was that unmaneuverable.

<comment><USER11> Isn't the traffic shitty (and dangerous) precisely _because_ of the occasional people "weaving, passing and lanechanging" like crazy?

<comment><USER9> When I make a right-hand turn onto the far-right lane of a divided highway with four lanes in my direction, and over the next three blocks, three lanes become right-turn-only (gradually narrowing the road down to one lane) but I need to not make any of those right turns?

You bet I need some fancy footwork to avoid being forcibly detoured. And you bet that once I'm in the correct lane, I make a point of emulating the people far in front of me, by almost-tailgating the person directly in front of me.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER12> I mean, I don't even get why people just idle their cars like that.

I've been told it's to keep the air conditioning on, but I see people idling with their windows rolled down, in the summer and winter alike. I've been told it's to play the radio, but most of the time I can't hear any radio and in any case, come on- you got a phone right?

There's no good reason that applies in most situations and that makes it even harder to understand. Because it means people just ...don't turn their engine off when they're only stopped for a while. Because. I don't know. It costs action points?

<comment><USER13> >I've been told it's to play the radio

Is it common for the car to need to be running to listen to the radio?

<comment><USER14> Not sure if sarcasm, but no.

</comment></comment></comment><comment><USER15> This man is my hero. I've knocked on dozens of car windows at Costco over the last several years, and now I realize I can get paid.

</comment><comment><USER16> I can't read the article (I really should subscribe) but I think people seriously underestimate the positive effects moving to electric cars will have on city livability and city property values. Because we're all born into a world where engine particulates are ubiquitous, I think we're missing how much of an improvement clean air would be.

<comment><USER17> Black carbon from diesel, train, and ship exhaust is incredibly toxic. I think it's going to be the equivalent of lead, in the future.

<comment><USER18> Not even close.

Lead does irreversible brain and organ damage to developing children. Carbon, at worst, may increase your chances for respiratory disease or lung cancer.

<comment><USER19> No at worst it increases whole-body inflammation.

<comment><USER20> This lecture is quite a good one for the health effects of diesel nanoparticles [https://youtu.be/aXEal4YJsOU](https://youtu.be/aXEal4YJsOU)

</comment></comment></comment></comment></comment><comment><USER21> We don't have that law in Hawaii, unfortunately. I used to love to eat at a local Quiznos which had outdoor seating, but was located next to a supermarket. People would park there cars five feet from where I was eating and let them idle for 20-30 minutes while they sort out their grocery list, or while one person runs inside to shop and the other waits. Made me crazy--the noise, the stink. I stopped eating their, and apparently everyone else did too, as they went out of business.

<comment><USER22> Quiznos have been going out of business everywhere for several years. I think this dead rat commercial was the beginning of the end: [https://www.youtube.com/watch?v=aZrks- BPeLQ](https://www.youtube.com/watch?v=aZrks-BPeLQ) (I'm sure the exhaust didn't help though!)

</comment></comment><comment><USER23> >...showing a video he'd taken with his phone of a concrete truck near the corner of William and Fulton Streets.

A truck carrying concrete has to keep the drum rotating to keep the concrete mixed. To do that it has to have its engine running.

<comment> cup-of-tea Yes but they shouldn't be doing it near people's houses. Concrete mixers are supposed to go directly to the construction site and deposit their load on time.

</comment></comment><comment><USER24> While I agree with the objective - that cars/trucks should shutdown instead of idling, I have to wonder, do we really want to a society where people are paid to report their neighbors? Sure it seems like this guy is doing everything properly (documenting real cases of random idling), but what happens when people start using things like this for harassment/revenge, fabricating idling cases (similar to the Uber vomit cleanup scam), and generally making a living off getting people fined.

Compare this to a trained law enforcement officer who doesn't personally make money on every fine who will take the whole situation into account, rather than just trying to make a buck.

This make work out fine at this small scale, but we should be cautious when it comes to creating untrained citizen bounty hunters.

<comment><USER25> _" I have to wonder, do we really want to a society where people are paid to report their neighbors?"_

It's sad, but I think we need do need this. Too many people are uncaring and ignorant, and will behave badly if they don't think there are consequences. We shouldn't just turn a blind eye to anti-social behavior.

<comment><USER26> I'd call reporting idling the anti-social behavior. Snitching on someone breaking an unjust law to save a meaningless amount of emissions.

<comment><USER27> Unjust??

<comment><USER26> Yes, it's unjust to not allow people to idle their cars. It's a minuscule portion of total emissions that's not worth the tradeoff of convenience.

</comment></comment></comment></comment></comment><comment><USER28> This dovetails nicely with a new study from Canada, which found 25% cars produce 90% pollution.

[https://www.sciencedaily.com/releases/2015/04/150421105344.h...](https://www.sciencedaily.com/releases/2015/04/150421105344.htm)

"The study made on-the-spot measurements of 100,000 vehicles as they drove past air-sampling probes of the main laboratory on College Street, one of Toronto's many major roadways."

Also interesting was their findings of how pollution from roads permeates the surround areas, and the complex ways pollution from multiple roads produces additive exposure.

</comment><comment><USER29> Engine exhaust is full of carcinogens. Given this, it is entirely fair to fine polluters in proportion to the level of harm they cause. Outsourcing the enforcement to citizens is a bit strange, but it is important work and someone should be paid to enforce the law.

<comment><USER30> Outsourcing the enforcement to citizens might be the only practical way to do it.

According to the article, in about 18 months, his 25% cut of the fines amounted to roughly $5,000. Assuming you could hire city employees to do it, you'd probably want to cover their salaries with the fines. Let's say city's overhead from prosecuting these cases is 25% (Judges need to get paid, too), so that's $15,000 in 18 months, or $10,000 in 12, if they spend as much time at it as this guy. He's obviously motivated, and keeping an eye out whenever he's on the streets, so let's assume a full timer can only manage about 10x as much vigilant time as him. That's $100,000/yr. Assuming you want to cover both salary and benefits, that might not be enough in NYC.

And, assuming the program were at all successful, then you'd expect revenues from it to drop rapidly as every commercial operator in the city starts warning their employees.

<comment><USER31> 100k/year is definitely well above (~2x) the median salary for someone in public service in a job like this in NYC. Police officers in the NYPD start around 42k/year.

<comment><USER32> Salary is just one of the costs. There's pensions, equipment, training, etc.

</comment></comment></comment></comment><comment><USER33> I suppose he got his wish considering newer cars automatically shut off the engine after idling for a few seconds, and turn it back on when you want to go.

<comment><USER6> This feature is far from universal at this point. You'll find it on some higher-end cars, but that's about it.

<comment> King-Aaron Stop-start cars are amazing when the battery/alternator starts getting a little dicky after a few years. Pull up to the lights, engine shuts down, and doesn't start back up. Genius.

<comment><USER34> Have you actually experienced this or are you just assuming it might happen in the future?

<comment><USER9> It's a very reasonable assumption for anyone who's been around cars for more than a decade of their lives. Electrical systems in most consumer-grade vehicles have rarely been able to exhibit the kind of reliability expected of most of the other nontrivial moving parts.

</comment></comment></comment></comment></comment><comment><USER35> What about refrigerated diesel trucks? When the diesel engine turns off, the cooling turns off. Has this tattletale also considered the horrendous emissions of engines whose catalysts cool down? Idling is sometimes cleaner, sometimes dirtier, this kind of blanket enforcement makes no sense to me.

Where I live in CA, people object to diesel idling more due to noise than anything else.

<comment><USER19> The refrigerator is usually powered by a separate engine mounted high on the front of the trailer.

</comment></comment><comment><USER36> Thanks, George. Now please get noise violations on the NYC cars that pollute our air with pealing horns. Cab drivers especially seem to spend their entire shift impotently honking.

<comment><USER37> When I was in Shanghai most recently, I found out that they had solved the issue of honking (which used to be even worse than anything we have in the US) by having these microphones at intersections triangulate honking, capture a photo, and mail the driver a ticket and link to the video. It's definitely on the scale of big brother, but it also works.

<comment><USER36> Damn, that's amazing. I would imagine that the city could be convinced by forecasting the money they would bring in on fines.

How does that system work for honking between intersections?

<comment><USER37> Good question, I wasn't able to find details, just some basics:

[https://radiichina.com/beijing-installs-car-horn- detectors-t...](https://radiichina.com/beijing-installs-car-horn-detectors-to- battle-noise-pollution/)

[https://www.shine.cn/archive/district/jing-an/Crackdown- on-h...](https://www.shine.cn/archive/district/jing-an/Crackdown-on-horn- cacophony/shdaily.shtml)

</comment></comment></comment></comment><comment><USER38> This absolutely pisses me off too, especially when it's right outside my home because it's also noise pollution. I don't understand these people... do they go home and just leave taps running while fiddling with their phones? there is no good reason to do this unless you are in an extremely cold environment.

<comment><USER39> Even in a cold environment it doesn't make sense to idle your car to warm it up.

<comment><USER40> Ever lived in a cold environment? You idle to let your heating system get up to temp. I grew up in a cold area and no way was I going to jump in my car right away in -20 degree temps.

<comment><USER39> Yes. Almost the entirety of engine wear occurs when the oil temp is too cold. By turning on the vehicle and immediately driving (conservatively below 2k rpms) you greatly reduce the amount of time it takes to warm up your engine oil versus when left idling at 500rpms. I learned this from reading the manual to my BMW and Subaru.

In -20 degree weather you won't accomplish much idling and should purchase an engine block heater if concerned.

Interesting article confirming what I am saying:

[https://www.washingtonpost.com/news/wonk/wp/2014/12/29/the-b...](https://www.washingtonpost.com/news/wonk/wp/2014/12/29/the- biggest-winter-energy-myth-that-you-need-to-idle-your-car-before- driving/?noredirect=on&utm_term=.a28864233635)

<comment><USER40> I don't doubt you, but I know for a fact that by turning on my car and waiting inside I could get in and the car was warm. No waiting. Did this for twenty years.

<comment><USER41> You two are talking about different things. Frye is talking about warming the engine compartment; Epic is talking about warming the passenger space. You can warm the engine compartment more efficiently without idling by driving at low RPMs for the first few minutes; however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area.

<comment><USER40> >however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area.

Again, twenty years of turning the car on, going inside for 15 mins, and coming out and sliding into a warm car.

I'm not anywhere near knowledgeable enough to explain the details. I am fairly certain however that I was not hallucinating this throughout my entire childhood and young adult years.

</comment></comment></comment></comment></comment></comment></comment><comment><USER20> If anyone wants to learn more about the health effects of diesel exhaust, beyond the oft publicized "lung cancer" risk, this is a very detailed lecture on the topic from a guy at WWU.

[https://youtu.be/aXEal4YJsOU](https://youtu.be/aXEal4YJsOU)

</comment><comment><USER42> What if more laws had monetarily incentivized vigilanteism?

<comment><USER9> Then more people would correctly point out the parallels with a variety of dystopias, including nonfictional examples.

</comment></comment><comment><USER43> Gitem tiger!

I wish we could go past idling and start mandating some serious emissions controls, especially on diesel truck and heavy equipment engines in urban areas, but also on all the rest of the emitters.

</comment><comment><USER44> Sounds like a problem that would easily be resolved by federal regulations that would turn an engine off after three minutes automatically unless some other switch, ideally obscured or hidden behind a ui, is pressed (has to be pressed each time the engine is started). Seems like a simple solution, like lights that turn off with the engine but like that advancement, it'll probably take decades to standardize without proper federal regulation.

</comment><comment><USER45> Well I certainly misread that title. I literally thought someone had weaponised (or whatever Batman like thing) exhaust.

</comment><comment><USER46> If only they could enforce against those ridiculous smoke-stacks people install on their trucks. Here in Texas - even in Austin - I probably see one or two a week: [http://www.slate.com/articles/news_and_politics/politics/201...](http://www.slate.com/articles/news_and_politics/politics/2014/07/rolling_coal_conservatives_who_show_their_annoyance_with_liberals_obama.html)

Every time I see one, I just want to drop a softball-sized lump of silly-putty down there.

<comment><USER47> Are you complaining about the chrome exhaust stacks, or about modifying the engine to purposefully produce lots of black smoke? At least in Denver, you can report the black smoke: [https://denver.cbslocal.com/2017/10/18/sheriffs- office-asks-...](https://denver.cbslocal.com/2017/10/18/sheriffs-office-asks- public-to-report-drivers-rolling-coal/)

<comment><USER48> Generally I assumed they went hand-in-hand, but maybe that's not always the case.

</comment></comment></comment><comment><USER49> Is a bounty for reporting an offense a common thing in the US (or elsewhere)? I've never heard of it.

</comment><comment><USER50> This sounds a bit stupid, drivers will wander instead that creates more emissions than idling.

</comment><comment><USER26> This is one of the most ridiculous things I've ever heard. 3 minutes? A $350 fine? Are you kidding me? I spend longer than that idling in a fast food parking lot eating my food. How do any judges sleep at night enforcing this? I'm not going to sit in a hot/freezing car in traffic if I can help it by running the climate control inside for a while first (definitely takes more than 3 minutes, or especially that particularly ridiculous 1 minute in school zones). I guess these people would prefer my dog suffer in the heat instead of sitting in air conditioning for 5 minutes while I get something out of a gas station. More and more reason I never want anything to do with NYC.

The goal of protecting the environment is so that it can better serve us in the future. The environment is not an end in itself. Idling regulations are far too great of an inconvenience compared to the tiny benefit. I hope this war on cars is just a fad.

<comment><USER51> _I spend longer than that idling in a fast food parking lot eating my food._

That's weird. Why not just go inside to eat?

As for the dogs, I'm sure the judges are happy to make exceptions for exceptional circumstances. It sounds like the law is targeted at the largest groups of offenders: commercial vehicles idling unnecessarily, and parents who (bizarrely, IMO) insist on waiting in a long line of cars to pick up their kid after school.

<comment><USER52> > ... parents who (bizarrely, IMO) insist on waiting in a long line of cars to > pick up their kid after school

The alternative is to constantly drive around, which is worse in terns of road safety and emissions.

<comment><USER51> The alternative is to let the kids ride a bus or walk. Or park and get out instead of sitting in your car idling.</comment></comment></comment></comment>


Why there won't be a third book in the Halting State trilogy - <AUTHOR> http://www.antipope.org/charlie/blog-static/2013/12/psa-why-there-wont-be-a-third-.html

<comment><USER2> The message is very clear: Charlie, you must write faster. Because of your lazy ways, you're not keeping up with reality, and reality has just caught up with you (in the sf writer world that is a bad thing, remember).

So crank it up already.

<comment><USER3> Not necessarily. Gibson has weathered it well, IMHO.

<comment><USER4> I think jwr is attempting to wind-up Charlie, given his notoriety for tweeting his daily word counts and the degree of trauma that this has caused him; often doused by evening libations in a local hostelry.

None of which is an excuse for his sluggishness.

</comment></comment></comment><comment><USER5> I reckon that there must be a lot of writers out there thinking: "Hell, it was meant to be a cautionary tale, not a creepy government manual".

Although, I do think that in essence we are seeing nothing new from governments, just new ways to perform the old tricks, with greater efficiency.

Hmmmm, now I wonder if the actual problem is efficiency. We mere humans are pitted against technology we simply have no sporting chance against.

<comment><USER6> Yeah, the last thing we need is another _manual_ for how governments should control the society in the future, as if 1984 wasn't enough. My guess is the people in NSA are already thinking about how to implement a Minority Report- like pre-crime system, that can be shared with all government agencies.

<comment><USER7> Precrime has been around since at least 2001 when the no-fly list was created.

</comment></comment></comment><comment><USER8> That's fine, I'd rather another Laundry book anyway.

<comment><USER9> Except, those sorta feel a bit worryingly realistic too, these days.

<comment><USER10> Yes real question is will Bob ever get that cat5 cabling project finished

</comment></comment></comment><comment><USER11> Dammit, Charlie, stop writing predictive near-future fiction! :-)

<comment><USER10> Actually I could think of some nasty disutopias post Scottish independence if there's a hung election and the hardline nats get their way.

<comment><USER12> Well go ahead and enlighten us rather than trolling this thread with baseless Better Together FUD.

Edit: I just saw the full version of your comment on Stross's website:

 _" And post Independence disutopias I could think of a few real world nasty outcomes for that as my Red Clydeside comrade said the NAT's have a (now well disguised) nasty sectarian/racist streak."_

Disclosure: I've been a SNP voter for all of my voting life (~29 years) and a card carrying member on and off during that time. I've encountered many criticisms about the SNP, some of which I agree with, others not, but that's quite a serious accusation and one I've never encountered, maybe you could cite examples of this? I've met plenty of sectarian voters who vote Scottish Labour (having campaigned for the party in Glasgow many times), but I wouldn't accuse the Scottish Labour party of having a hidden seedy sectarian underbelly.

<comment><USER10> yeh you right its both "traditions" As one of my Scottish colleagues said the thing that saddened him him about Scotland was the "nasty element of anti englishnes" and sectarianism that was common. And he was very knowledgeable about scotish politics and his facility with "engineering" language makes malcom tucker look like a middle class mommys boy.

There are parts of Scotland where I would feel uncomfortable coming from a mixed (RC/PROD) background.

I could see a post Independence Scotland pandering to right wing anti emigration lobby and or religious or anti gay presure - the same thing happened in Northern Ireland John Major had his feet held to the fire by the hardline unionists -

I think thats on the far end but in the context of a future sf dysutopia not that much of a stretch after all coutrys like Holland had far right politicians making ground.

<comment><USER13> "I could see a post Independence Scotland pandering to right wing anti emigration lobby and or religious or anti gay presure"

There are far right nutters everywhere - but I like to think we actually have relatively few of them in Scotland, certainly UKIP seems to be doing remarkably badly here:

[http://www.politics.co.uk/news/2013/11/18/ukip-s-scotland- op...](http://www.politics.co.uk/news/2013/11/18/ukip-s-scotland-operation- falls-apart)

<comment><USER10> Well the EU is seen positively by Scotland as it gets a fair bit of subvention for infrastructure.

Though go to one of the fishing ports and ask a Scottish fisherman about fishing quotas and You might get a different answer.

<comment><USER12> The EU and Europe is seen as valued by Scots because of things like the European Convention on Human Rights [1] which the current Westminster government are doing their damnedest to undermine.

Also Europe is a huge trading partner for Scotland. I'm not saying the EU is without its faults, but at least an Independent Scotland would ensure Scots have a better say in European policies than the efforts being made by Cameroon and Co.

I agree that fishing in Scotland has suffered badly over the past 20 years, but the blame is squarely with Westminster and the Scottish parliament hasn't been able to do much to reverse the current situation because it's a reserved matter.

[1]: [https://en.wikipedia.org/wiki/European_Convention_on_Human_R...](https://en.wikipedia.org/wiki/European_Convention_on_Human_Rights)

</comment></comment></comment></comment></comment></comment></comment><comment><USER14> UK leaving the EU. Scotland leaving England (but presumably still a Commonwealth nation...). So take that to the extreme, with the return to city- states, Burning-Man style with citizens moving house in their shipping- container homes as their loyalties/desires change.

<comment><USER15> One of the great stories of the political landscape today is the... impedance mismatch, for lack of a better word... between technology enabling ever more decentralized control (and for "control", read "government"), and the fact that everywhere you look, centralized governments are expanding their power.

It's one of those thing we're all too close to see clearly, and I do not exempt myself from that problem, but I suspect in a hundred years it'll be one of the "big stories" told about this time period.

<comment><USER16> Strange how centralized governments everywhere are expanding their power under what are, universally, "small government" neoliberal regimes.

<comment><USER17> Not strange at all. Neoliberals are for big government everywhere except government regulation of big business. They want government and big business to work together as one organization of plutocrats to control everything.

<comment><USER18> Have you burned all the strawmen, yet?

<comment><USER15> Again, by words, "nobody" wants that. By actions... there's plenty of governing official that clearly do. Many of them have a "liberal" label on them. Many of them have other labels on them, too. Labels aren't as interesting as actions, though; distracting people with labels is one of their prime tools.

</comment></comment></comment></comment></comment></comment><comment><USER19> I love Charles Stross but I've had a really hard time with the second person narrative in Halting State.

<comment><USER20> At first it felt weird, after a few pages it started to feel like a fun gimmick, and after a few more pages I didn't really even notice it anymore.</comment></comment>


Eliza in GnuCOBOL (2017) - <AUTHOR> https://sourceforge.net/p/open-cobol/contrib/514/tree//trunk/samples/eliza/eliza.lst <comment><USER2> Why linking to that .lst ? It's some strange output and contains error messages. The source is here:

[https://sourceforge.net/p/open- cobol/contrib/514/tree//trunk...](https://sourceforge.net/p/open- cobol/contrib/514/tree//trunk/samples/eliza/eliza.cbl)

and I'd like to know if the source compiles.

<comment><AUTHOR> Thanks. It didn't occur to me that that wasn't the source. (It doesn't look like I can edit it the OP.) BTW, it does compile. I've been in communication with the author and he has shared with me additional code and details. I've asked his permission to share it here (and encouraged him to share it himself).

</comment></comment><comment><AUTHOR> The author, Arnold Trembley, tells me (reposted with permission):

I have a link on my website:

      https://www.arnoldtrembley.com

for an executable download for Eliza in GnuCOBOL that runs on Windows 7 and higher.

I also have GnuCOBOL compilers available for download at:

      https://www.arnoldtrembley.com/GnuCOBOL.htm

<comment><USER3> It looks like he forgot the extension to his site. Is it com org net edu?

<comment><AUTHOR> The full url is there. It's just truncates on narrow platforms.

</comment></comment></comment><comment><USER4> For everyone who also had not heard of Eliza: [https://en.wikipedia.org/wiki/ELIZA](https://en.wikipedia.org/wiki/ELIZA)

It is a chat bot from the 60s that acts as a therapist.

<comment><AUTHOR> Thanks, but I doubt anyone hasn't heard of Eliza ... at least no one here!

<comment><USER5> or Dr. Sbaitso for that matter.

</comment></comment></comment><comment><USER6> There was a Lisp interpreter written in COBOL on the HN front page today. An option for Eliza in COBOL might have been Eliza on Lisp on COBOL.

</comment><comment><USER7> Gnucobol formerly opencobol uses c as an intermediate language and offer nonstandard functionality to link/call arbitrary c libraries. This of course opens the door to lots of peculiar "in cobol" apps.</comment>


How Quartz Onboards New Users - <AUTHOR> http://www.useronboard.com/how-quartz-onboards-new-users/ <comment><USER2> Pretty damn cool.

After completing the onboarding, I checked the app again 30 minutes later so they're definitely doing something right...</comment>


Show HN: a new team chat web/irc tool - nic-ferrier http://www.teamchat.net

<comment><AUTHOR> Congratulations, Nic, on what is likely the world's first Emacs-hosted startup! For those who don't know, teamchat is implemented in Emacs Lisp using Nic's elnode (async web server) and shoesoff (IRC bouncer) libraries, among others.

<comment> nic-ferrier Thanks jlf!

You guys at #emacs have helped this happen. An awesome community.

</comment></comment><comment><USER2> Well, that was deflating.

Sent out the link to several co-workers (since we are looking for this sort of tool right now) and then we all get the "We'll let you know when we go live" email.

So thanks for making me look like an idiot.

<comment><USER3> This^. Did the exact same :S

<comment> nic-ferrier If you ping me on twitter I'll make sure you're prioritized. We are obviously wanted teams to try this to tell us what is good and what isn't. So if you're a team we want you basically.

</comment></comment></comment><comment><USER4> I would be really excited to try this. Is it live yet? I always think it's better to save Show HN posts for products that we can actually play with. Looking forward to seeing this in any case.

<comment> nic-ferrier I know... I know. I prefer that too.

The trouble is this is for teams, you kinda have to have a team. We wanted to gauge interest so we've done it this way.

If we can we'll go live for collections of people (if there are 2 or 3 people from the same company email domain) this week or next.

<comment><USER2> Can you please make it clear on the register page that there is no publicly available product yet?

I had three guys from my team sign up so we could test it out, and only after signing up did we find out that it's not live yet.

<comment> nic-ferrier will do. I'll also try and make sure you get prioritized for go live.

</comment></comment></comment></comment><comment><USER5> I'm about a day away from releasing Gnotty, which is a similar tool but open source: <https://github.com/stephenmcd/gnotty>

Mobile-friendly IRC web client, private rooms, and bots with commands/webhooks.

<comment> nic-ferrier I'm not going to advertize it that much (because I don't want to support people that way yet) but all the code behind teamchat.net is freely available on github.

<comment><USER5> Awesome :-)

</comment></comment></comment><comment><USER6> Doesn't appear to be live yet (the confirmation email says they'll send a message when they are).

</comment><comment><USER7> Minor point: It would be nice to be able to click those screenshots and get bigger versions. It's currently very difficult to see what the application looks like.

<comment><USER8> There are some bigger screenshots on the about page.

</comment></comment><comment><USER9> Just a heads up: you haven't set a page header/name yet!

<comment><USER10> There's also an extra closing div tag in there.

<comment> nic-ferrier awww man. templating. thanks for catching.

<comment><USER11> Images are not clickable for full resolution.

<comment> nic-ferrier they are now.

</comment></comment></comment></comment></comment><comment><USER12> I built something like this (a long time ago) for my own purposes. So did a startup we're working with!

That says there might be a need for it, but on the downside it's really simple to build, so competition can spring up very quickly.

<comment> nic-ferrier it's simple to build a simple one... but the more polished takes more time. Why not just offload that work to someone else? That's our view anyway. We've chatted to some potential clients and other companies running their operations this way.

</comment></comment><comment><USER8> Love the idea! About time someone did this. What's the tech stack like?

<comment> nic-ferrier It's all emacslisp. Including the webserver (it's elnode). So there is an irc bouncer written in elisp tightly integrated with the elnode webapp. The bouncer uses a modified rcirc (built into emacs) to connect to the irc servers.

The robot framework is also written in emacslisp.

The irc servers are ngircd and the webserver is nginx.

<comment><USER13> Bomb-diggity. I saw your gravatar and immediately thought "Omy is this an el- node projet!?" Sweet.

<comment> nic-ferrier I'm kinda surprised that people haven't picked up on that bit and asked questions. You'd have thought hackers would be interested in that bit :-)

</comment></comment></comment></comment><comment><USER14> I tried to register with a .co.za (South Africa) domain name and it caused the following error: not a valid email address?

Looking forward to seeing the product!

<comment> nic-ferrier That should be fixed.

</comment></comment><comment><USER15> kind of similar to grove:

<https://grove.io>

<comment><USER15> i think what could really make the difference is the video chat feature though. if properly implemented...does it work fluently?

<comment> nic-ferrier Yes. We're veterans of previous video startups. This is video meeting done right. It's not a big part of the product but it is important coz it means you don't need skype or hangout or whatever in addition to this.

<comment><USER16> I'm looking to write an open source app with basically similar video chat functionality. Could I ask what's the best way of implementing this?

I'm guessing WebRTC would be the way to go... once it is released at least

</comment></comment></comment></comment><comment><USER17> www.mebeam.com/chat_team

<comment> nic-ferrier yeah. there are loads of alternative video chat apps. that's not the point of teamchat.</comment></comment>


Ask HN: Is OMEMO a good alternative to Signal for federated XMPP? - <AUTHOR> I recently learned about OMEMO, which is trying to replicate what Signal did with double ratcheting, but on top of Jabber/XMPP.
https://en.wikipedia.org/wiki/OMEMO
What does the HN community think about this protocol? Is it a good idea?
And also, how are the actual implementations? From my experience, OTR implementations were horrible and often incompatible with each other, and I ended up going back to plaintext (oh, the times before Signal).
Conversations seem nice, but I don't like this quote from wikipedia - "E2E encryption there are OpenPGP, OTR Messaging, and OMEMO to choose from."
I am not sure more choice is good in this case. But I don't know the application itself, maybe it's done well.
(edit: well, it looks a bit confusing in the app itself, unfortunately. https://conversations.im/images/screenshot_encryption_selection.jpg Default is plaintext?)
Also, how is the server support? How error prone is it, etc.
edit: also, how is the support of group chat (like Signal has) and of synchronizing devices (like Signal has with mobile-desktop sync) <comment><USER2> Co-author of the OMEMO standard and lead developer of Conversations here. To answer your question one after the other.

> What do we think about this protocol?

It's the first encryption protocol that allowed me to actually use it on a daily basis. I regularly use my desktop client and my mobile client in parallel and switch between them constantly. OMEMO allows me to do that.

> Is it a good idea?

Yes. Compared to OTR the entire stack (that includes the XMPP layer) is properly standardized. This also kinda answers your questions regarding the OTR implementations. OTR had the problem that it couldn't do multiple devices and the behavior regarding multiple devices and when to start and end sessions wasn't defined at all. All OMEMO developers are also in regular contact to coordinate behavior between the apps.

> Why are there three encryption choices I would really like to get rid of OTR > (and we will eventually) but we currently still need it for backwards > compatibility with older clients (primarily Pidgin) PGP servers a bit of a > different use case. It doesn't provide forward secrecy and authentication > but it turn allows for a server-side re-retrievable archive. If you get a > new client it can automatically retrieve old messages. (In OMEMO the > receiving must exist at the time of writing. It doesn't have to be online > but it has to exist and announced the device specific key material)

In reality the choice isn't too much of a problem. You select it once per contact and that's it. It's not like you are getting new contacts every day.

> How is the server support.

The server requirements for OMEMO aren't too bad. However it is recommended that you do pick a modern XMPP server for other reasons (battery-friendliness, reliability). Have a look at this comparison list to see if your server supports all modern extensions: [https://gultsch.de/compliance_ranked.html](https://gultsch.de/compliance_ranked.html)

> How is the support of group chat

Support for group chat exists and works fine once it is setup. However it has some limitations that make setup harder. Everyone has to be in everyone elses contact list. And the group needs to be setup with special parameters. (Conversations automatically sets it up this way, but you couldn't for example create the group with Pidgin and then expect OMEMO to work.) The readme on the Conversations github page explains this in a little more detail: [https://github.com/siacs/Conversations/blob/master/README.md...](https://github.com/siacs/Conversations/blob/master/README.md#omemo)</comment>


Criticism my startup HN por favor: It's a free server monitoring app - <AUTHOR> http://cloudiff.com/demo Built using these technologies: http://cloudiff.com/humans.txt Took us 4 months to this point. Still a work in progress. Love to hear out feedback. Good night hnewers :P PS - to this point, you've been ignoring me. Zero feedback.  Nada. <comment><USER2> It looks cool but I think it needs a landing page that explains what it does and how I'm supposed to use it.</comment>


Raspberry Pi announces $50 12-megapixel camera with interchangeable lenses - <AUTHOR> https://www.theverge.com/2020/4/30/21242454/raspberry-pi-high-quality-camera-announced-specs-price <comment><USER2> Much better article from official blog: [https://www.raspberrypi.org/blog/new- product-raspberry-pi-hi...](https://www.raspberrypi.org/blog/new-product- raspberry-pi-high-quality-camera-on-sale-now-at-50/)

</comment><comment><USER3> For anyone curious about how "good" the camera is: with the lens they sell it's about as good for still pictures as a modern phone. Somewhat worse for video, depending on your application, due to stabilization, software, and the 2-lane interface.

More specifically, the sensor is a Sony IMX477, slightly better than the IMX377 featured in the Nexus 6P, Nexus 5X, HTC 10, and Mavic Pro drone.

Pretty nice, for $50 in a neat little package. This kind of thing is usually a good bit more expensive.

<comment><USER4> the standardized lens mount will be huge (as in popular and successful)

<comment><USER5> you could buy C-mount "unauthorised"(1) clone camera modules from China for several years now.

(1) Pee foundation actually puts DRM chip on camera modules to deter third party accessories.

<comment><USER6> Could you be more specific about the DRM? I thought that they just supported a few cameras and didn't care too much about third-party clones (for better or worse).

<comment><USER5> [https://twitter.com/marcan42/status/1088506051295567872](https://twitter.com/marcan42/status/1088506051295567872)

</comment></comment></comment></comment></comment><comment><USER7> Anybody found info on the max frame rate? High frame rate is super common in phones but hard to find elsewhere, and I need it for a project...

<comment><USER8> The original pi camera can be made to run at 660 fps with reduced line count, pretty neat hack!

[https://blog.robertelder.org/recording-660-fps-on- raspberry-...](https://blog.robertelder.org/recording-660-fps-on-raspberry-pi- camera/)

</comment></comment><comment><USER9> I want one. It would be really nice if they had a monochrome model for metrology purposes but for $50 I won't complain.

<comment><USER10> Well, for a 50$ camera, I'd be comfortable attempting to debayer it. Basically, scratching off the Bayer filter using some sort of tool that wont scratch the silicon.

<comment><USER9> Never thought of that. I have plenty of old cameras I could practice on.

</comment></comment></comment><comment><USER11> Do we have more sample photos to judge the quality?</comment>


Ask HN: What are reputable sources of Covid-19 information? - <AUTHOR> It's hard to know where to look, what to believe, or who to trust regarding COVID-19. I doubt that anything you can find on a major news site, or anything ranking highly in search engines is unbiased.<p>I'd like to compile a list of resources (mail lists, videos, talks etc) that are at least somewhat reputable or trustworthy, not sponsored or skewed--experts who have done (or are doing) their homework and working to educate others. Of course no one knows the real whole state of the world with 100% certainty, but I know there are people who know better than me, and I'd like to find them! <comment><USER2> [https://coronavirustechhandbook.com/](https://coronavirustechhandbook.com/) is pretty comprehensive and backed by Nesta. [1]

For visualisation I use: [https://boogheta.github.io/coronavirus- countries/](https://boogheta.github.io/coronavirus-countries/)

[1] [https://www.nesta.org.uk/press-release/coronavirus-tech- hand...](https://www.nesta.org.uk/press-release/coronavirus-tech-handbook- technologists-around-the-world-are-crowdsourcing-ideas-to-combat-covid-19/)

<comment><AUTHOR> These are awesome thanks for sharing!

</comment></comment><comment><USER3> I've been using [https://globalepidemics.org/key-metrics-for-covid- suppressio...](https://globalepidemics.org/key-metrics-for-covid-suppression/) to track case numbers daily in the US. It has visibility down to the county level.

</comment><comment><USER4> I've been enjoying watching LockdownTV interviews: [https://unherd.com/lockdown-tv/](https://unherd.com/lockdown-tv/)

</comment><comment><USER5> [https://covidreference.com/](https://covidreference.com/)

</comment><comment><USER6> reddit.com/r/covid19

</comment><comment><USER7> PubMed</comment>