Facebook launches Nearby Friends - <AUTHOR> http://newsroom.fb.com/news/2014/04/introducing-a-new-optional-feature-called-nearby-friends/

<comment><USER2> While this seems like a really cool idea, I have a feeling that this is the sort of feature that everyone will enable at first, and then one single bad event will cause them to disable it forever.

I'm sure everyone has told a "white lie" at some point (e.g. "Sorry, I can't really hang out tonight because I'm not feeling well" == "I want to go see a movie by myself"), and anything that might hinder your ability to do that is likely to be disabled permanently the first time it causes an issue (or even in anticipation of it causing an issue).

<comment><USER3> It's weird because they've had a feature similar to this before. It was under a tab called "Nearby" or something in their left navigation. If I remember correctly it was web only but a user could access it on their phones through the mobile site. I liked it. It wasn't as one-to-one as this iteration of it though. It would only show you where someone recently checked-in. It was quite accurate though.

It eventually just went away. I wonder why they got rid of that, but now are doing something like this.

<comment><USER4> I remember this feature. I also remember that hardly anyone of my friends used checking in so it was fairly useless :)

</comment></comment></comment><comment><USER5> While most posts are touching on privacy or failure cases, I am still struggling to understand this product from a social perspective. First of all, this general idea has been floating around since companies like loopt, when mobile started taking off. I remember working through the use case considerations for this kind of product, and that's where it really dies.

This breed of product is based on the idea that location = event. If someone is at a location, that means something is going on. But it ignores massive implicit social constructs: 1. Facebook friends are not real friends (Circles is slightly better but classification is onerous), 2. Someone you don't know well is unlikely to share their location to you, and less likely to agree to hang out based on location, in contrast someone you do know well, you will easily be aware of their location and availability.

The reality is that this product captures one piece of information - where is my friend right now. But on any serious reflection, you should be able to discern that this piece of information is incredibly secondary to the nature of the actual relationship when determining whether or not to hang out.

<comment><USER6> One place I can see this being useful is at music festivals or other large open-area events. Often you're going with other people, but you're not necessarily going to stick together the entire time. Being able to find each other easily would be a nice improvement, as phone-tag is a pretty terrible way to do it.

</comment></comment><comment><USER7> I can see both sides of this coin. On the one hand, the positive use case is actually pretty helpful -- I _would_ like to know if I'm at a bar and, for example, some friends are in the back that I might have otherwise missed.

But on the flipside, this has the potential to turn a lot of social situations slightly sticky -- I immediately think back to a friend's "worst date ever" story where she was asked out by a guy who later cancelled because "work stuff came up". And then she ran into him, drunk, with his buddies, at the same bar.

At least before FB he could have hidden under a table! ;)

<comment><USER8> It might be interesting if they could add some kind of geofencing feature to it. So you could have it automatically be enabled when you're hanging out at the bar you go to when you want to see friends, but be disabled otherwise. It's good that they let you turn it on and off whenever you want, but having to do so manually seems like a chore that will cause me to just leave it off all the time.

<comment><USER4> Creating a whitelist sounds a bit tedious. Because it might look fun at first, you would add a few places, but then forget it forever, don't update them and the feature would slowly die.

Blacklist makes more sense. E.g. I don't want people to know where exactly do I live. Or automatic disabling at specific dates, e.g. during the weekend.

<comment><USER8> Yeah, good point.

</comment></comment></comment></comment><comment><USER9> Will this be smart enough to not tell me every time my friends who live next door to me are nearby?

<comment><USER10> I can imagine sitting at a bar with friends and getting notifications on my phone that they are nearby.

</comment></comment><comment><USER11> Geolocation features aside, I'm more impressed by the fact that Facebook has created something that's opt-in rather than volunteering people right off the bat.

</comment><comment><USER12> I remember google latitude had this feature years ago and I thought it was really cool, but they killed it because people complained about it.

I thought it was neat to be out at some family event or the mall etc. and get notices that your friends were nearby.

<comment><USER13> It's still there in Google+, under locations.

<comment><USER12> Maybe I remember them switching it from opt-out to opt-in then? Did that ever happen?

I kind of wish it was opt-out by default, but I know that would probably cause a huge controversy. People are already collecting your location data anyway - might as well use it with your friends/people you'd actually want to have it.

<comment><USER13> Yeah I think that happened around the time they started sharing data between products. It's hella useful when it comes down to it (and you can be quite restrictive with your location in G+).

</comment></comment></comment></comment><comment><USER14> I created a similar service a while back at [http://www.nearbyfriends.com](http://www.nearbyfriends.com). Here is a video describing the launch: [http://vimeo.com/15039067](http://vimeo.com/15039067). I later added proximity alerts so you could see when your Facebook friends check in near you. Funny to see Facebook launch a similar "Nearby Friends" three years later.

</comment><comment><USER15> I live in the northern suburbs of Atlanta, about 30 miles from the center. I have a local group of friends that I get together with on a weekly basis. But this feature seems like it might help me see my city-based friends on a more regular basis. Times that I drive into the city, or fly to other metro areas for conferences and meetings, I'd love to know if I have FB friends nearby to meet up with.

</comment><comment><USER16> What about automatically chatting with ANYONE nearby you that is using the app and "available" for chat?

I think this will be a good idea.

Imagine you in traffic, and launch the app to chat with the driver in the car side yours... The same could works when you go to party and don't try to find somebody "available" there....

This, for Facebook, should be easy, right?

<comment><USER17> Spott ( [https://itunes.apple.com/us/app/spott/id591300005](https://itunes.apple.com/us/app/spott/id591300005) ) is exactly what you're talking about.

It's basically nearby _anyone_ , with the connection being a location instead of a phone number, email, username, etc... They have done a good job at keeping the content focused on useful information, rather than dick pics.

The downside is it really only has a strong user-base in Chicago.

<comment><USER16> Great app! And really nice job with useful information instead of simple chat.

After remember that Twitter have already an "location flag" when you tweet from mobile, I did a search for something that use it, and found it: [http://nearbytweets.com/](http://nearbytweets.com/)

It seems that this is the same idea with Twitter users...that is also interesting

<comment><USER17> Thanks! We're working on Twitter integration with our next release (1.2.2). Twitter's streaming API opens up a lot of cool new features for us to add.

<comment><USER16> do you are from Spott team? Great!

I think improve it with twitter integration will be great. And, maybe, let an optional "public chat" (without images and with flood control) maybe let it more 'popular'

if you want to discuss more feedback feel free to found me on me at dougcorrea.com

:)

</comment></comment></comment></comment></comment><comment><USER18> The problem with this type of integration in such a widespread app is that it can become problematic to explain to someone, like a significant other, why you would have a need to not share your location with them. It can be difficult to counter the "what do you have to hide" line of reasoning.

</comment><comment><USER19> Not bad, I think this will end games of phone tag where people mention vague landmarks for friends at large events.

Due to Facebook's usage, I think this will take off. No need to convince friends unsuccessfully to install another app.

</comment><comment><USER20> Eventually Glancee [1] see the light! Congrats guys ;)

[1] [http://www.glancee.com](http://www.glancee.com)

</comment><comment><USER21> Tencent's QQ and Wechat IM services have been doing this for a long while, both are very popular. Nice catch up FB.

</comment><comment><USER22> The folks who recently poured millions into connect.com are NOT going to be happy about this.

</comment><comment><USER23> Not really related, but does anyone know why newsroom.fb.com is running on WordPress?

<comment><USER24> because they don't want to reinvent the wheel?

</comment></comment><comment><USER25> I would prefer that my nearby friends not be launched anywhere.

</comment><comment><USER26> An invasion on privacy for those people whom FB can trick into activating the feature.

</comment><comment><USER27> Haha, there goes your privacy to Facebook's advertisers.</comment>


How many companies that use Google's ML engine have read the ToS? - <AUTHOR> "Customer will not ... use these Services to create, train, or improve ... a similar or competing product or service ... such as cars, TVs, appliances, or speakers without Google's prior written permission" "..Customer will provide Google with any assistance Google requests to reasonably confirm compliance with these terms (including interviews with Customer employees and inspection of Customer source code, model training data, and engineering documentation" <comment><USER2> The link: [https://cloud.google.com/terms/service-terms#12-google- cloud...](https://cloud.google.com/terms/service-terms#12-google-cloud- platform-machine-learning-group-and-google-cloud-machine-learning-engine)

Seems kind of limiting and overreaching at the same time.</comment>


Galois Theory for Beginners (1994) [pdf] - <AUTHOR> http://www.drchristiansalas.org.uk/mathsandphysics/abstractalgebra/galoistheoryforbeginners.pdf

<comment> alan-crowe Unsolvability of the general quintic pared down to just 6 pages. Manages to dodge needing the normality of field extensions and the Galois correspondence between subfields and subgroups.</comment>


Why airlines make flights longer on purpose - <AUTHOR> http://www.bbc.com/capital/story/20190405-the-secret-about-delays-airlines-dont-want-you-to-know <comment><USER2> The "What airlines don't want you to know" tone of this post is misplaced and misguided. I also question the suggestions that longer published flight times mean more CO2 and there's no incentive for airlines to become more efficient.

Here the airlines are doing pretty much exactly what I, as a passenger, want, which is to predictably arrive at an airport by a certain time more often. If a plane takes less time to fly somewhere some of the time because of weather, timely takeoff from departure airport, landing slot availability at the arrival airport or whatever, I don't really care. If they arrive late however, that can be a huge problem, particularly for making connections.

As for CO2, the plane flying slower is more fuel-efficient. Isn't this lower CO2 emissions?

40 years ago there were so many fewer planes in the skies. You could fly as fast as you want, take off when you want (pretty much) and land when you want. Well, lack of satellite navigation and tracking mattered but basically the skies were less crowded. Just the other day I flew out of NYC and it took us 40+ minutes of being in a queue to take off behind 15-20 other planes because reasons. You have to have that padding in your schedule.

<comment><USER3> The idea that padded schedules leave airlines with no reason to be efficient is idiotic. It's a heavily capital-intensive industry with razor-thin margins that has historically been a bad place to make money. There's even a classic joke about it: "How do you make a small fortune in the airlines? Start with a large fortune."

This is the industry that generated the famous story where American saved $40,000/year by going from two olives to one in their in-flight salad. United saved $300,000/year by printing their magazine on lighter paper. If you work at an airline and find a way to shave off a dime in fuel costs per flight, you'll get articles written about you. And we're supposed to believe that these companies don't care about wasting fuel now that their schedules are padded out a bit?

<comment><USER4> The iead that airlines have no reason to be efficient in it of itself is idiotic. It is an incredibly competitive industry, and the lengths to which airlines go to explore every possible margin is enough testament of that.

To add to your list of examples. KLM, for instance, was one of the first to introduce a system that would allow certain flight data to be uploaded into the flight computer as opposed to be requiring the pilots to enter it by hand. Other than fewer errors, they touted potentially saving pilots a couple minutes of data entry as one of the chief gains of the system.

<comment><USER5> I generally avoid the word "idiotic", but it fits here. Can we flag articles for stupidity?

Article tl;dr -- Airlines used to get from airport to airport faster. Airlines used to be late a lot of the time. Airlines increased their estimated flight times in order to achieve higher on-time percentage. The reason they did this instead of just being faster is that they love using more fuel.

I'm not anywhere near the airline industry myself. The next time I see misreporting on my own company or industry I'll look back at this and remind myself it could be worse.

<comment><USER6> The increased the time so that they won't be fined for not being on time.

</comment></comment></comment></comment></comment><comment><USER7> This is a surprisingly poor article from the BBC.

So, padding, according to this article has a negative environmental impact. But that argument isn't justified and doesn't make sense, most time lost is either unavoidable for the airline (e.g. airport problems/weather) or at a phase of travel without the engines running (boarding delays, waiting for a gate, etc).

Flying slower is actually a environmental win since aircraft are more efficient at slower speeds (although costs more to the airline due to staffing/opportunity cost).

They seem to want us to believe that if padding was removed, and airlines magically got more efficient, that they'd use less fuel but what is the mechanism? What phase of flight sees the fuel reductions? It is like they don't know that aircraft often use either ground-power or only the generator while waiting.

In fact the core premise of the article is clickbait. Oh no, airlines are making sure you can plan your travel times accurately by accounting for common delays within a route! The horror! Sorry, but not biting today.

<comment><USER8> It's not just flying slower. If you've ever flown into London, you are probably familiar with the notion of a holding pattern. When things get busy at the airport, due to poor scheduling, it is quite common for planes to fly in circles for 10-20 minutes or even longer in some cases.

Also, planes sitting on taxi lanes burning fuel with six planes in front of them is a common issue. Planes are assigned landing and take off slots and if they miss those, that's a problem.

So, if the schedule is unrealistic, planes might be taking off "on time" knowing full well they'll be circling downtown London for some time.

<comment><USER9> It's not poor scheduling, so much as Heathrow being at 99.5% capacity which means queuing is required so they can maintain one landing per minute.

<comment><USER10> Yeah, the airport is at capacity. I'm not seeing how it has anything to do with schedule padding at all. They're doing take-offs and landings there as quickly as possible.

<comment><USER8> Airlines know before they take off their ETA to the other side pretty much down to the minute. Their planning builds in padding so that they are guaranteed to make it on time. Which means they expect to arrive early and end up in a holding pattern because the take off slot and landing slot are deliberately misaligned. This is exactly what the article is implying.

That's of course aside from the inevitable issues arising from operating at 99% capacity. Anyone familiar with queuing theory or logistics knows that this just means things pile up at the cost of delays and extra fuel being burnt. So, that too is poor planning. You never operate systems with queues at close to 100% capacity unless you are looking for severe cost overruns and bottlenecks.

This poor planning results from misaligned incentives. Airports can just park planes in holding patterns for however long they desire. It's not their fuel being burnt. So they over provision knowing full well they will have planes in holding patterns throughout the day, This maximizes their revenue. So they are actively incentivized to do this. Likewise, airlines buy fuel cheaply and only get penalized for being late. So they are incentivized to implement padding.

So, the fix is re-aligning the incentives for airports and airlines to minimize planes in holding patterns and fuel being burnt. There are several ways to do this but the bottom line would be making sure both airlines and airports aim to not have planes in holding patterns because that costs both of them something.

</comment></comment></comment></comment></comment><comment><USER11> The title is misleading, it should be: "Why airlines are allocating and publishing longer flight times than are actually needed to fly a certain distance"

<comment><USER12> And the answer: Because 40% of flights used to be late, now it's only 15%, reducing the amount of compensation airlines have to pay out.

Moving the goalposts. The article tries to make it look like a bad thing, like they're skirting their responsibilities (avoiding payouts), not improving their efficiency and punctuality (which is down to late passengers, which they either have to wait for or have to remove their luggage for, OR other factors outside the airlines' control), and that it's bad for the environment. But what if, and this may sound totally wild here, what if the schedules were too tight to begin with and they've just been adjusted to compensate?

I mean yes, the article makes mention that thanks to padding, a lot of flights seem to arrive early. But is that a bad thing? It means there's a lot more space to play around in. And planes can fly a bit slower, or fly at whatever speed they are most efficient at, instead of having to rush.

<comment><USER13> >But what if, and this may sound totally wild here, what if the schedules were too tight to begin with and they've just been adjusted to compensate?

In a perfect world this would be solved by having a 90/95/99% percentile arrvial _window_ rather than an arrival time.

<comment><USER14> You can often get that data if it really matters to you (flightstats sells it, for example), but I'm not sure I want to be running an MCMC analysis every time I book a ticket.

</comment></comment></comment></comment><comment><USER8> A simple fix to incentivize more fuel economy is to stop excluding it from fuel taxation, as is still the case in a lot of places. E.g. most EU countries tax fuel for cars, quite heavily, but not for planes. This exemption is starting to look pretty backwards and there is a fair bit of lobbying going on by aviation companies to prevent this from happening.

Low fuel prices currently allow planes to compete with trains for domestic flights in Germany even when the time gained is dubious at best. E.g. Berlin to Munich is a 50-60 minute flight and a 4 hour train journey. However, the train has no checkin and boarding queues and gets you from the downtown area of Berlin to the downtown area of Munich instead two 30-40 minute taxi rides away. If you factor that in, the train starts looking pretty damn good. Flying is still a little faster but so much less convenient.

It might also inform their choices for looking more fuel efficient alternatives. E.g. Berlin-Munich is well in range of the several electrical planes currently under development. IMHO a fleet of hundreds of these could revolutionize domestic flights by allowing cheap, clean flights directly between small city airports that are currently impossible to fly to because of noise and runway length.

<comment><USER15> > stop excluding it from fuel taxation

Problem for this is that it needs coordination at least on a continent- spanning scale. If the UK decides to tax av fuel but any one of the Netherlands or France or Germany don't, Heathrow stops being a hub airport pretty damn quick, hurting both the economy and the flight options of southern England.

Just like with corporate taxes, countries have an incentive for a race to the bottom, so coordinated action is needed.

<comment><USER13> >Problem for this is that it needs coordination at least on a continent- spanning scale

Sounds like a job for EU and/or the US federal government.

</comment></comment></comment><comment><USER16> Obviously we need to hold airlines to account to improve their environmental impacts, but I appreciate padding. I know I'm getting fooled, but if it makes sharing ETAs and making peace with a journey, I'd much rather it than be delayed continually.

I think most of us can appreciate the logistical challenges keeping increasingly busy airports running on time, and whilst we need to ensure operational improvements are being made I don't think airlines are deliberately ignoring this (in an age of squeezed profits, being more efficient is the only way to go for them). Padding just makes sense.

<comment><USER17> We are not even being fooled. The claim that someone is being fooled when a flight follows its published schedule is nonsense. It is also nonsense to suggest that this somehow removes incentives for airlines to be more efficient, as inefficiency has its costs.

The whole article has the petulant tone of someone having a hissy fit over not getting everything he would like.

</comment></comment><comment><USER18> This really sounds like a non-issue. As a consumer, I'd much rather have them over estimate the flight schedule and arrive early than the reverse. I live near a smaller regional airport and end up having layovers basically anytime I fly anywhere more than 200 miles away, so I always relax a little easier when I pilot tells me we're landing ahead of schedule on my first leg so I know I wont miss my connection.

As for carbon emissions, I'm guessing that whatever padded on time is spent at the gate isn't really an issue, it's more about drawn out approaches when landing. It seems perfectly reasonable to me that something like this happens when you have so many planes entering and leaving an airport, it's amazing to me that things go as smoothly as they do. Plane travel isn't going anywhere and it seems a little absurd to me that flight time needs to be completely min-maxed down to the minute due to carbon emissions, there are definitely easier and more effective ways to control this.

</comment><comment><USER19> I dont think this article is completely correct, and I dont see padding as a "trick". If the arrival window is more accurate by adding padding to the flight time, then I can plan more effectively when I get to my destination. Aren't airliners also flying slightly slower than they used to in an effort to save fuel(and lower emissions)?

</comment><comment><USER20> This is actually what any other mode of transportation that uses a schedule has to do: if you have a schedule, you have to take some precautions to ensure you can keep to the schedule most of the time, otherwise you can forget about the schedule. Here in Germany, this is very obvious for bus lines on streets that are usually very busy - they have so much "padding" in their schedule that on less busy days the buses have to travel at 30 km/h instead of 50 km/h to avoid running ahead of schedule.

<comment> Harvey-Specter Here in Canada I've had to sit and wait on the bus while the drive goes into Tim Horton's (coffee shop) because the bus is ahead of schedule.

</comment></comment><comment><USER21> Huh? This article is ridiculous.

> It's called "schedule creep", or padding. And it's a secret the airlines > don't want you to know about, especially given the spillover effects for the > environment.

So… let me get this right… because the announced scheduled arrival time is announced as being an hour later than usual… somehow the plane spends more time in the air and is worse for the environment…

I think the author missed their morning cup of coffee.

> Padding drives higher costs in fuel burn, noise and CO2

Again, with the unsubstantiated and ludicrous claim that an airline giving itself room on the schedule for operational issues not to cause cascading effects somehow means more time in the air, more noise, and more emissions.

I give up. I hope nobody takes this article seriously.

<comment><USER22> Ok, I'm not the only one. For the most part the gate-to-gate timeline is extremely predictable. They already have the clearances set up and know what route they're flying so the flying bit is not really going to change much outside of unforeseen weather or traffic delays. The variable part is loading, unloading, and staffing issues (someone didn't make it to work) and occasionally absorbing the impact of flight delays.

I suspect the net effect is actually a decrease in CO2 emission because the delay stack at the end of the day doesn't force pilots to bump the throttles a little to cut some time on flights with lots of connections as I've seen them do before.

</comment></comment><comment><USER23> So this is possible. I fly on JAL all the time for work (internationally). They are pretty much always right on time for all schedule flights. They do things very differently then the US airlines I fly on. They make announcements about boarding time, status etc. more often. They announcements include things like walking time to the gate. There are way more people at the gate organizing the boarding queue and handling the ticket and passport checking then I have seen at other airlines. They have clear signage about which line is for what and walk around with the signs to make sure everyone understands. When you board the aircraft the crew is actively involved in making sure you are able to get in your seat and get your bags put away. If you have a connecting flight with a tight window there are personal at the plane exit waiting for you to help you make the next flight. I have always been impressed by their level of service and detail. I recently had a flight through Tokyo back to the US. As I walk off the plane that just landed and look out the window I can see my bag already off the plane and being put on a cart for transfer. I had a 40 minute window on an international connecting flight through Narita. I would never ever try to schedule that on another airline. I made it with 20 minutes to spare and my bag showed up at my destination just fine. Oh the other amazing thing is that priority tag on your bag for their frequent flyers for making your bag come out first really works, even when landing in SFO or LAX.

I really feel this is a matter of organizational skill and planning. The US airlines just do not care to put in the effort.

[https://www.jal.co.jp/en/info/flightstats.html](https://www.jal.co.jp/en/info/flightstats.html)

</comment><comment><USER24> In my experience, fixing ground ops would be the biggest boon to efficiency and customer satisfaction. My experience these days from doing a lot of domestic flying in the U.S. is that lack of ground coordination (takeoff queues, gate availability, randomly sitting on the tarmac for an hour) cost a lot of money and time. If the state of planes in the sky can actively be used to optimize ground ops at airports, I think that'd help consumers and reduce some costs. Other than that, I think consumers could forgive the padding in flight times. If I take off 20 minutes late and still arrive 10 minutes early, I'm happy, so the psychology continues to work.

</comment><comment><USER25> Problem: "Planes are consistently later than our stated arrival times"

Solution: "Why don't we give more accurate arrival times, so passengers can be more confident in those stated arrival times and minimize disruption to their travel plans"

The Guardian: "This is bad for the environment"

Literally the article is saying that when airlines stopped optimistically lying about arrival time, this somehow poisoned the planet. Despite the fact that both before and after the change being complained about, flights took off at the same real timestamp, spent the same amount of real time in the air, and landed at the same real timestamp.

</comment><comment><USER26> HN can be funny. Since this is an article about the airline industry, a lot of people here are criticizing them for setting lower expectations and padding times. And this is an industry that deals with so many environmental, regulatory, administrative and personnel problems completely out of their control.

On the other hand, if it's an article about how "PMs ruin software engineering by pushing for unrealistic deadlines", all of a sudden a job role that depends largely on just people and their (fairly reliable) computers justifies 2x or 3x the time estimates.

</comment><comment><USER27> The JAL flights from London to Tokyo and back really annoyed me last year because of padding. The LHR to HND leg arrived 45 minutes early, which meant I had 45 minutes extra of early morning time in Tokyo and 45 minutes less snoozing to try and get ahead of the jetlag.

The return trip was different, if the plane had departed on time it would have reached London at a time when inbound flights are not allowed due to noise restrictions. That meant it was about 2am by the time I was able to board the plane, again not ideal for sleeping.

</comment><comment><USER28> This is an idiotic article.

First, to suggest that padding comes at the expense of operational improvement is wrong; well-applied padding _is_ operational improvement.

Second, some of those time losses are due to the move from turbojets (which are fast, screamingly loud, and inefficient) to high-bypass turbofans (which are slower, quieter, and much more fuel efficient).

More time is lost as planes usually have to fly complex noise-abatement profiles and navigate more crowded and complex airspaces before they get to cruise.

</comment><comment><USER29> United has a route where the return leg is so short that they make you sit in the plane for an extra hour after you land.

The issue is that they're required to take off from Ben Gurion airport before a certain hour to meet the nighttime curfew / noise abatement requirements. But that has the flight landing in SFO an hour before the customs and immigration desks open, and they're not allowed to open the doors until then.

Wish there was a way to make this particular flight a little longer...

</comment><comment><USER30> I think the fallacy here is that they can just push back from the gate, trot directly to the runway and takeoff. In any major airport, that's a crapshoot.

I've been spending a lot of time watching ground ops from

[http://www.airportviewer.com/airport/KSFO](http://www.airportviewer.com/airport/KSFO)

(courtesy of HN, posted a few months ago). There are times when the planes pile up 14 deep. I saw JFK up to 20 planes on the ground waiting. This is hardly the airlines' fault.

What I dont understand is why they don't use wide-body planes more. I mean, I know the standard explanation: they use too much fuel on short-hauls. But why can't the manufacturer solve this problem, either by reducing the wing size or changing the shape, to have a wide-body, short-to-medium haul aircraft?

Aviation continues to grow, so while I understand the removal of hub-and- spoke, to the distributed pattern, it seems like if there's enough customer demand to run N 737's/A320's per day from SFO to, say, DEN, why not run 0.6*N 777's instead. Or what if southwest slowly replaced their '37 fleet with "short range 777s" ?

Or, more specificially, why don't they enact regulations at some of our busiest airports and say "Sorry, but at peak hours at JFK, you can only arrive/depart wide-body aircraft". Half the planes that run SFO are these tiny skywest embraer and bombardier jets. During peak times, restricting their use and requiring at least a '37 or a320 could boost capacity significantly (+100 people per takeoff/landing)

<comment><USER31> >Why don't they use wide-body planes more

Off the top of my mind, there are some other non-fuel factors

1- A competitive schedule in a business market includes offering a high number of frequencies, so running several flights on a narrowbody is preferred over a widebody

2- Building off of the above, you can segment your customers better, charging more for business-friendly timing

3- You mention seeing the tiny Skywest regional jets at SFO. While I'm not too familiar with United's route structure, I'd guess that most of these routes may not support a narrowbody (either because of mainline costs or demand)

4- Delta apparently used to run tiny regional jets out of JFK when Jet Blue was starting up in order to squat on slots, but also disrupt operations, since Delta would be much less impacted than Jet Blue.

<comment><USER30> I think #2 is the strongest case. Wendover Productions talked about that a lot, how you can have 6 different prices for the same flight. #4 is terrible, that's not competition, its warfare. Again Wendover talked about something similar. Icelandair tried going to Dallas, so American immediately began a Dallas route to make their competitor suffer. That may technically be "competition", but the spirit of it is malicious.

I think we should revert to the hub and spoke system. Have huge jets that do nothing but travel between hubs all day. Let the business people have their half, and let the cattle buy essentially last-minute bus-tickets to traverse the country. Then book your ticket from the hub to home. Even though that's inefficient compared to direct routing, a 2 or 3 hour ground delay costs the same (in time) as going from CHI->LAX and then backtracking to phoenix or vegas to your final destination.

Another thing I think could work would be "JIT" routing. where you dont even know where your connections will be, until the day you fly. then you could have sudden, "ad-hoc hubs" that suit that particular day's distribution of travelers. Each morning a huge rack of computers could solve that day's "travelling-salesman problem" of weather, demand, location of aircraft, etc and come up with an optimal solution. people wouldn't like this at first, becuase of fear of the unknown, but I suspect it would lead to monumental increases in efficiency.

<comment> T-hawk How do you propose to have crew available for every possible permutation of that routing? It would take an enormous standing population at every airport in the system, only a small portion of which will work on each given day. Good luck finding employees to take on that arrangement. Routing is about scheduling more than just aircraft.

<comment><USER30> The crew would be probably the easiest parameter to optimize because they don't have a choice. Let's say the current configuration has a set of crew in PHX and on wednesdays they normally go to denver, 2 hrs away. with a dynamic configuration, they can expect to go on any 2 hour flight or less. the only commitment to the crew is that they are to be returned to their home city on their first day off. If they have enough seniority, then they can be put on the top list of employees to draw from to go to DEN if thats what they want. I don't see the problem. The crew could be routed just as dynamically as the PAX.

</comment></comment></comment></comment></comment><comment><USER32> Beyond the considerations in this article, I've always found it fascinating that none of the big jets flying today is as fast in routine operation as the first American airliner, the 707. The difference is small, and the reason is partly to do with fuel economy, but it's a very good example of how technology doesn't always go forward in the expected direction.

A similar analogy in computerland is how many of us are doing most of our computing on devices much less powerful than the ones we had ten years ago, a function of switching to mobile devices and high-overhead virtualized computing.

<comment><USER33> also capacity. larger plane need larger wing that enter into transonic regime earlier than smaller wing.

[http://www.aerospaceweb.org/question/aerodynamics/area- rule/...](http://www.aerospaceweb.org/question/aerodynamics/area- rule/transonic-drag.jpg)

[https://en.wikipedia.org/wiki/Drag- divergence_Mach_number](https://en.wikipedia.org/wiki/Drag- divergence_Mach_number)

you want to be below or above transonic, and above transonic is banned pretty much anywhere.

</comment></comment><comment><USER34> Is it really true that when flying at less speed you burn more fuel? If air resistance grows quadratically with speed, I would assume that it is not, but there might be another effects on wing efficiency that I ignore...

<comment><USER35> The drag/speed curve of an airplane is actually U-shaped. Parasitic drag does increase with speed, but induced drag—the drag that results from the production of lift—is highest at slow speeds. The combination of these two curves is a U.

The bottom of the drag curve is the speed at which the airplane will achieve maximum range for a given quantity of fuel; 76% of that speed will achieve maximum endurance. The distinction between range and endurance is that of distance versus time. Max range will get the most distance out of one pound of fuel, while max endurance gets you the most time out of that pound of fuel.

</comment></comment><comment><USER36> Out of all the scheduling problems the author could have talked about: min connect time, early departures, interline agreements, incidental stops. This has to be one of the more reasonable ones.

Many of the above hint at problems that provide uncertainty and doubt into Travelor itineraries but the discussed topic literally provides more certainty and assists with ensuring less missed connections.

There are some routes and airports that outside of expensive infrastructure cannot handle much more traffic. If you find out you made unreasonable promises you make them reasonable or try and make them possible.

</comment><comment><USER37> The article confuses the differing responsibilities of airlines, airports and air services (ATC) who then work together to deliver a realistic schedule.

Airlines are motivated to maximise fleet utilisation so the narrow focus on padding is a misleading and overemphasised element to judge the intent of this specific delay mitigation.

The industry is moving towards increasing collaboration, the article I think avoids mentioning the IATA recommended ACDM approach instead pitching a companies PoC from one of their sources.

</comment><comment><USER38> > However, this global trend poses multiple problems: not only does your > journey take longer but creating the illusion of punctuality means there's > no pressure on airlines to become more efficient, meaning congestion and > carbon emissions will keep rising.

Am I missing something? It's not like flights are spending more time in the air compared to before - it's just that you wait longer and your flight leaves late vs schedule. So how does that increase carbon emissions?

</comment><comment><USER39> Hard to reconcile the title with this observation: _" Part of the problem is schedules are designed by airlines for perfect conditions"_.

There's a lot of available info for US flight delays at bts.gov

One good example: [https://www.bts.gov/topics/airlines-and- airports/understandi...](https://www.bts.gov/topics/airlines-and- airports/understanding-reporting-causes-flight-delays-and-cancellations)

</comment><comment><USER40> This article leaves out air traffic control, which is a major issue. In the US, ATC is a very manual process, and planes get slotted into routes that are more a factor of what the ATC personnel can deal with than anything else.

In most cases, aircraft get lined up in the sky in lanes. If your plane is nice and new and can move efficiently at a higher speed, it doesn't matter because it will get stuck behind an old crappy plane that cannot.

</comment><comment><USER41> The hub and spoke system also contributes to the congestion we see at the airports. A distributed system would be more tolerant to issues like weather, and you can afford to pad flight schedules with little impact on congestion due to the fewer throughput of planes at any one airport. This of course may not make financial sense for the Airline to distribute their operations, would need to be regulated.

<comment><USER42> We're already starting to see that change. As traffic has grown airlines have added more point-to-point flights that skip the hubs. Newer aircraft have also changed the economics of those route changes well and enabled more point-to- point flights that weren't previously economical.

</comment></comment><comment><USER43> This article is informative but poorly thought out. Most delays are out of the airlines' control and generally involve congestion.

Unlike 50 years ago when there was little air traffic and airlines could pick the most direct route, today that is no longer the case. Flights are indeed longer because flying the most direct route or the route with the best tailwinds is no longer possible.

I'm surprised BBC didn't do more fact checking.

</comment><comment><USER44> I didn't understand how this is wasting fuel. Does ATC make them fly slower rather than landing early?

<comment> Harvey-Specter Theoretically a plane may have to sit in a holding pattern if it arrives too early, either due to congestion at the airport or not having a landing slot.

</comment></comment><comment><USER45> I've read that the reason why flights have gotten longer is fuel efficiency. Flying slower saves fuel. This was a strategy adopted when fuel prices spiked years ago and it was kept in place because of cost competition.

<comment><USER46> You shouldn't be downvoted, average cruise speeds now are less than in the 1980s and considerably less than in the 1960s. And modern short / medium haul airliners are designed for lowet cruising speeds.

Ryanair notoriously uses a very aggressive Cost Index for flight planning which favours absolute economy over speed, to the extent that sometimes ATC complains about their low cruising speed

More about CI: [https://www.skybrary.aero/index.php/Cost_Index](https://www.skybrary.aero/index.php/Cost_Index)

</comment></comment><comment><USER47> Finally an explanation. I have been wondering about this.

In my nativity I had always assumed that airline do this to reduce fuel consumption by flying more slowly and hence reducing drag. :)

</comment><comment><USER48> "Increasing success by lowering expectations" ;-)

</comment><comment><USER49> TL;DR:

1) planes fly at a lower speed to save fuel

2) help airlines to claim they have improved on-time (OT) flight performance

3) it makes it easier to swerve the "magical three-hour limit" on delays – the threshold that qualifies passengers to file compensation claims at least under European Union passenger rights' law.

<comment><USER14> #3 is a little annoying, especially when the airline is uncommunicative.

It's natural to assume that an N hour departure delay will cause you to arrive N hours late, and that your connections or other plans will be thrown off accordingly. However, that's not often true—-schedule padding and changes in flight plans[0] often make up for some of the difference, though they often don't tell you this until you're in the air. It would be great if more gate agents could give you an expected departure AND arrival time during delays.

[0] I would not be surprised at all if the airlines explicitly trade off fuel costs vs. the costs of compensation. In other words, if you're already late, don't waste fuel try to make up all of the lost time, but use just enough to avoid a compensation-triggering delay.

</comment></comment><comment><USER50> I believe wind speed and direction has a significant effect on flight times - making them inherently unpredictable and risking knock-on effects.

</comment><comment><USER51> No kidding, an internatial route I take was 8.5 hours 8 years ago and now it is 11.5. I am not sure this is a result of padding or scheduling.

</comment><comment><USER52> Why don't they just arrive early most of the time? For passengers, being early is as good as "A0".

</comment><comment><USER53> This article reads like a not-very-well-disguised ad for the methodology that Baiada is selling.

</comment><comment><USER54> TL;DR: Airlines used to set SLOs that they couldn't hit consistently. They updated the SLOs based on actual performance, and now they hit them much more consistently. Article author seems to believe the pointy-haired boss idea that if they went back to the original (over-optimistic) SLOs then the airlines would somehow increase performance to hit them.</comment>


Ask HN: How many tech startups file IPO per year in USA? - <AUTHOR>

As a person outside USA, I hear about buzz around IPOs of companies like Group-On and Facebook. I wonder who many start-ups grow big enough to file IPO every year on an average.<p>If there is any USA specific data please give me pointers. <comment><USER2> 42</comment>


Universities not teaching front-end development is a diversity problem - <AUTHOR> https://medium.com/code-like-a-girl/universities-not-teaching-front-end-development-is-a-diversity-problem-13921107c66f#.qyb3qpndj <comment><USER2> Front end development changes so fast that you could not include it in a university curriculum the way universities are structured. (i.e. if you spent 7 years in the rat-race of getting tenure, any skills you have about front end development are 7 years old)

<comment><USER3> Not to mention that universities are by their very design not suited for teaching craft, which is much better taught by actually working in the industry. Universities are suited to prepare for research.

</comment></comment><comment><USER4> "the fact is that without front-end development, technologies aren't widely usable"

Sounds like a false statement to me. A lot of backend systems are very widely used via APIs and various integrations.</comment>


Ask HN: PR for Startups? - <AUTHOR>

Long-time HN member using a throwaway account for business reasons.
I'm thinking about launching a PR firm focused on helping startups/small companies and am hoping for some feedback.
I know it's been done before, but I haven't seen it executed well. I've spent time at both startups and PR firms and still see a massive void that needs to be filled.
I understand there's a stigma around hiring PR firms at small companies because they're typically too expensive, they don't understand the needs of a small company, they don't help you acquire new customers, the results are difficult to measure, etc.
So, what else? What are you looking for in a PR firm? Would you never, ever hire a PR firm? Do you currently work with an awesome PR company that I should know about? In SF and want to discuss over coffee? Any feedback in the comments or by email (in my profile) would be greatly appreciated. <comment><USER2> Could you model your PR business to take equity in exchange for your services? Most lean startups wouldn't be able to pay you much cash, but I think a lot of them would be willing to give you equity. In fact, I think taking equity rather than cash would offset the "the results are difficult to measure" issue you mentioned; if I give you $5,000 to do some PR for my startup, then (to my mind) you have the money regardless, and you could be spending 60 hours a week for two months traveling the world and evangelizing about my startup to all the right people, or you could just ask a friend to post it to his blog and call it good.

If you have equity, however, then your profit is tied directly to the success of my startup, so I could rest assured that you would have a (literal) vested interest in making my company successful.

</comment><comment><USER3> This is a question I too have been asking myself over the years. I'm a marketing consultant, and I LOVE startups. But trying to find work with early stage startups is really difficult because they generally can't pay much, or prefer to hire developers over marketing resources. So I end up working mostly with companies that are further along and have revenue, but wish I could figure out a way to work exclusively with startups and still make a living. If there were a way to scale these services beyond just a 1:1 effort to revenue ratio that would be ideal...

Thought you might like this article: [http://thenextweb.com/media/2011/08/21/pitch-perfect-a- start...](http://thenextweb.com/media/2011/08/21/pitch-perfect-a-startups- guide-to-getting-coverage/)

</comment><comment><USER4> Happy to be your alpha tester =)

<comment><AUTHOR> Awesome! Drop me a line with your contact info at pr.hn.01 (at) gmail (dot) com and I'll be in touch shortly.</comment></comment>


San Francisco declares state of emergency to prepare for coronavirus - <AUTHOR> https://www.businessinsider.com/san-francisco-state-of-emergency-coronavirus-covid19-outbreak-2020-2#the-citys-tech-conference-scene-has-also-taken-a-hit-1 <comment><USER2> While the sensationalist headline is technically accurate, both the headline and the linked article bury the intent and context of the declaration. In short, don't panic.

[https://www.sfchronicle.com/bayarea/article/SF-mayor- London-...](https://www.sfchronicle.com/bayarea/article/SF-mayor-London-Breed- declares-state-of-emergency-15083811.php)

> There have been no confirmed coronavirus cases in San Francisco to date, but > as infections continue to rise across the world, "we need to allocate more > resources to make sure we are prepared," Breed said at a press conference > announcing the emergency declaration.

> "To be clear, this declaration of emergency is all about preparedness. By > declaring a state of emergency we are prioritizing the safety of our > communities by being prepared."

<comment><USER3> I feel like the debate between the "don't panic" crowd and the "preppers" is a useless semantic debate between extremists.

You want to react the _appropriate_ amount. For the time being, you should go about your normal routine, but like the CDC said today, you should _prepare_ for some major lifestyle disruptions.

<comment><USER4> I can comment on a couple unexpected shortages we've seen in Asia: toilet paper, due to panic buying, and hand sanitizer.

There are also some concerns about medicines unrelated to the virus because many meds are produced in China and the supply chain here is all screwed up. So some might consider getting medicine refills for 30 days (or however long your insurance will let you) in advance. You also might not want to have to go wait in line at a pharmacy during a pandemic.

In terms of work: it may make sense to start thinking about what kind of work can be done efficiently remotely vs. on-site.

You also may want to think about finances in case the world sees a significant economic contraction. If lots of countries replicate what has happened in China, the world economy will be highly disrupted for at least a couple months.

<comment><USER5> Super useful comment. R.e. toilet paper, random observation: buy a bidet and you basically won't need to buy tp very much any more. They are very inexpensive at least in the states. You can get one for $20 or so.

<comment><USER6> Hopefully you have running water. I'd still recommend keeping some TP in case water goes out in toilet.

<comment><USER5> Yep, we have a backup supply. That said if there's no running water for a prolonged period we are eventually going to start having other problems. Fwiw I don't think that is an anticipated outcome even of a global covid-19 pandemic.

</comment></comment></comment></comment></comment></comment><comment><USER7> Whether or not this turns into a real pandemic I'm really curious how the world survives a real one in the sense of all the disruption.

Sure some desk based jobs can be done at home but it seems like nearly every restaurant, bar, and store would likely go out of business. As would airlines, trains, maybe hotels. Grocery stores would have to go 100% delivery only? Maybe be open 24/7 so people can spread out? Or would I need to wear a hazmat suit to get food? Note: there was a family riding the bullet train in cheap hazmat suits a few days ago.

I really have no idea. I suppose you can look at cities in China and see a full response.

I see lots of people saying "prepare" but then list having a week of supplies. Seem more like you'd need 6 to 12 months of supplies. Unlike an earthquake a pandemic would hopefully not stop the water flow or electricity like say an earthquake might but conversely it will be much longer before it's declared safe to return to any normal routine.

<comment><USER8> As much as I hate to say it like this, a pandemic is only going to kill something like 5% of the population at the top end. The Spanish flu in 1918 infected 500 million people, which was 27% of the population (according to Wikipedia). The death toll was about 40-50 million (possibly up to 100 million at worst). It was one of the most deadly worldwide infections in the history of the world, but probably killed less than 3% of the population.

A pandemic is going to severely hurt the economy, but it won't completely stop it. It will not be the case that nothing will be produced for months on end. People _will_ go to work. Farmers _will_ produce food. There _will_ be shops. But things will also be in short supply. Prices will probably rise. Poor people will be hit harder and there will probably be some famine (or at least more than there is now). But things will still continue.

In an event like an earthquake, entire distribution lines are shut down because you can't physically get somewhere. With a pandemic, things will be in short supply because labour is in short supply.

<comment><USER9> > Poor people will be hit harder and there will probably be some famine

I wonder how the extreme wealth distribution today will affect this. Although looking at statistics [1] it seems it was even worse in 1922 (no numbers for 1918).

[1]: [https://en.m.wikipedia.org/wiki/Distribution_of_wealth](https://en.m.wikipedia.org/wiki/Distribution_of_wealth)

</comment></comment></comment><comment><USER10> San Francisco has Moscone Center. One unlucky unscreened attendee and good bye world. Skipping all conventions until all clear.

</comment><comment><USER11> It's only a matter of time before this becomes a massive problem for the city. I applaud UCSF for not letting the two patients from Santa Clara start a local outbreak.

</comment><comment><USER12> It boggles the mind that there was absolutely no mention of COVID-19 preparedness at the recent Democratic debates, and that Trump's been trying to significantly cut the budget of the CDC.

Our leaders have their heads buried in the sand.

At least SF is trying to prepare.

<comment><USER13> > absolutely no mention of COVID-19 preparedness at the recent Democratic > debates

I guess you are referring to an older debate but here is what they said on the subject tonight.

[https://www.cbsnews.com/news/democratic-debate- coronavirus-o...](https://www.cbsnews.com/news/democratic-debate-coronavirus- outbreak-democrats-how-they-would-respond/)</comment></comment>


Interview with a hedge fund manager - <AUTHOR> http://nplusonemag.com/?q=node/418 <comment><USER3> Still halfway through it, but it's a good read so far. I like this quote:

"Today we have a recruiting group, and what do they do?—they throw resumes at you, and it's, like, one business school guy, one finance major after another, kids who, from the time they were twelve years old, were watching Jim Cramer and dreaming of working in a hedge fund. And I think in reality that, probably, if anything, they're less likely to make good investors than people with sort of more interesting backgrounds."

I talked to a lot people in a lot of fields before landing where I am today and the people in each one who really knew what they were talking about all shared the same belief as this hedge fund manager. Much of the technical knowledge necessary for these jobs can (only?) be learned on the job. But the ability to look at problems in innovative ways comes from having more lateral experience.

<comment><USER4> HFM also makes a point of looking for those with mental agility and intellectual interest outside of a desired application field.

This and the "paradigm shift" are two great insights.

<comment><USER3> I also liked the paradigm shift discussion.

Also, great section on assumptions and how sometimes disbelieving the most commonly held assumptions - the value of the triple A paper in this case - <USER2> lead to extraordinary profits.

</comment></comment></comment><comment><USER5> This was such an awesome dialogue. Awesome interviewer, and an awesome hedge fund manager.

It's hard to read as an entrepreneur because I think there's a difference between financial people, such as hedge fund managers or venture capitalists, and entrepreneurs.

Most entrepreneurs that I know are highly optimistic, and almost willing to look beyond risk and uncertainty. Of course, that's not to say entrepreneurs are stupid with risk, or don't take calculated risks. But I would say investors are much more risk-averse.

What I took away from this article: the housing market was too good to be true. You took Triple-A credit, and stuck it in the same pool as Triple-C credit. And you bet on the whole thing. I think that was pretty risky, and maybe it would have worked out if you rolled the dice a few more times, but most people just can't afford these houses. And now we're seeing the burst.

I suppose it's a bit sobering to read. It reminds you not to be stupid about risk, but definitely take risks. I better just stop there ;)

</comment><comment><AUTHOR> This link is just to give a reference point for the second interview: <http://news.ycombinator.com/item?id=310285>

</comment><comment><USER6> This is great. In particular:

"What tends to happen in financial markets, is bad things happen when you really divorce the people who take the risk from the people who understand the risk."

</comment><comment><USER7> _I think what we need to do is go to everybody's house and make sure that only licensed statistical arbitrage traders have black boxes._

What a great idea. I thought I lost the ability to be surprised by recent remedies proposed, this one still got me.

</comment><comment><USER8> Nice read for some fresh thinking. Makes me smarter.

</comment><comment><USER9> _In the situation we have today, where people have made bad investment decisions, where people built houses they never should have built, there's a misallocation of resources. The loss has already happened. The loss isn't what happens on a balance sheet: the loss is what happens when someone cuts down a tree, makes cement, builds a 6,000-square-foot house in a place it should never be built. So the loss has already happened. The question is: How do you allocate that loss? And if you don't allocate the loss, if you pretend it isn't there, then this has really baleful consequences for the economy._

I would invest my money with this guy. most people in the financial sector don't seem to realize the real life consequences and causes of the markets they manage.

<comment><USER10> This is more about over-leveraged institutions crashing out as growth in the derivatives market reverses than problems with the construction of actual houses.

You can buy and flip a home without building one. You just need easy credit and a rising market.

</comment></comment><comment><USER11> Wow, n+1 turned out an article that was no-nonsense, interesting to read, and not utterly full of itself. Props to it.

</comment><comment><USER12> From the second interview.

"they needed to take Bear out and shoot it in front of everybody. So they took it out, at a 2-dollar offer, all the senior management is gone, and that's the financial equivalent of taking the shareholders out and shooting them."

<http://news.ycombinator.com/item?id=310285>

</comment><comment><USER13> seems like a smart enough guy...typical "trader"...doesn't care about the direction things are moving, as long as they are moving. traders hate a sideways, sluggish market...they need volatility. he must be happy these days.

i disagree with his implied comments on the dollar. this is a dead currency as of friday. i expect the debt to hit twenty trillion by 2018.

look at the wikipedia page for the french revolution. accumulation of vast excess debt destroyed the monarchy. no one thought things would/could end... they thought they could just abuse the currency forever and somehow things would magically turn around, even though everything they actually did just made things worse. sounds like america today

i say the dollar will not last until 2025. no dollar...no USA. USA _IS_ the dollar.

<comment><USER14> _i disagree with his implied comments on the dollar. this is a dead currency as of friday_

The interview is from January, which in Hedge Fund Manager years is, like, three aeons ago.

You'll notice that the dollar has been going up recently, and is in fact pretty much back to historical norm levels, so it seems the market does not share your pessimism.

<comment><USER15> _the market does not share your pessimism_

The market is pretty good at ignoring things that it doesn't want to see. Regardless, I'm not too worried. Every time there is a recession, the media tries to make it look like the sky is falling. Remember the Savings & Loan "crisis" that was going to ruin the economy for decades? Yeah, turns out that it didn't happen.

Even if the dollar is weak, there is still a lot going on in the US. The world can't really write the US off, and the US isn't going to be a "loss leader" like China... so eventually the economy will recover.</comment></comment></comment>


Improved Authentication for Email Encryption and Security - <AUTHOR> https://protonmail.com/blog/encrypted_email_authentication/ <comment><USER2> "In ProtonMail's one-password mode, the mailbox password is derived from the login password via a one-way cryptographic password hash."

I wondered why they didn't do this. As a customer, this is a welcome change.

One thing that is of general concern to me: I tend to use a lot of encrypted traffic because much of my work is done on SSH shells to servers, and some of my customers request encrypting work files and use VPNs. With also using ProtonMail, I would expect to be on a government list of some sort. Given the general anti-privacy and anti-encryption rhetoric from public government officials this is a concern.

What our government should do is a moon-shot level of effort to promote strong encryption and very robust digital infrastructure. While this might unfortunately make law enforcement's job a little more difficult, the advantages in fighting computer crime and generally saving businesses, citizens and the government money would be worth it. I think it would also increase our level of national security, with all of our systems less hackable.

<comment><USER3> "What our government should do is a moon-shot level of effort to promote strong encryption and very robust digital infrastructure."

They did. It was called the Computer Security Initiative. It was the culmination of efforts starting with Anderson Report that collectively invented INFOSEC and deployed high-assurance versions. Early releases were secure messaging, the BLACKER VPN, MLS endpoints, private databases, and so on. Industry ignored it in favor of cheapest, fanciest products with features moving at explosive pace. Congress's (or DOD's) COTS mandate and NSA's MISSI initiative finished it off by reducing government contracts for high-security product.

So, it's been done here before. It would work again. Just no will to do it on top esp with Microsoft and IBM's lobbying. ;) At least the papers on requirements and methods for achieving that were all published. Some still use the methods in commercial sector and CompSci. The first, secure systems are still available comnercially on not-so-secure hardware (i.e. Intel). Just almost no uptake in FOSS for such methods despite a labor advantage.

<comment><USER4> "At least the papers on requirements and methods for achieving that were all published."

Hi there! Ive seen you post on these before; do you have a collection of links or references to papers an infosec engineer interested in this should read? Ty

<comment><USER3> Send me an email at address in my profile. Ill send them to you as I dig them out.

</comment></comment></comment></comment><comment><USER5> We had this at Lavaboom (German encrypted email, bankrupt) 2 years ago. Our designer came up with this idea, I initially wanted to implement the classic 2 password design. The tricky bits are (1) explaining to the users that they can't reset their password and (2) supporting users who opt for manual key management (e.g. I own firstname.lastname@example.com and I want to move from Google Apps + GPGtools to Lavaboom/Protonmail/etc).

[https://github.com/lavab](https://github.com/lavab)

our (brilliant) designer [http://www.felixvonlooz.com/](http://www.felixvonlooz.com/)

<comment><USER6> >The tricky bits are (1) explaining to the users that they can't reset their password

So that's interesting, because as I understand it ProntonMail does allow users to reset their password using a recovery email, although the feature can be disabled in the settings.

<comment><USER7> If a user resets their single password or encryption password, they lose access to their previous e-mail. This is because what essentially happens is that a new PGP keypair is generated and the Secret Key is encrypted with the new password. Since we do not have their old, lost, password we cannot access their secret key to decrypt the e-mails (and subsequently re-encrypt them with the new Public Key).

</comment></comment></comment><comment><USER8> So how does one migrate from the two password to the one? I like the idea of protonmail, but since they made it incompatible with normal public key encrypted mail it's pretty useless for many of us, unfortunately...

<comment><USER9> PGP is quite difficult to use by most people, and it doesn't even support forward secrecy, which is a _huge_ weakness. It will never be used by more than a core group of highly technical, which is maybe less than 0.01% of the population.

If we're to push end-to-end encryption to the masses, then we ought to try to get forward secrecy in it, and it should be quite invisible to the user.

That's not to say that ProtonMail is getting it right, but it's at least one of the few that are striving to move in that direction.

Relevant post from Moxie from Open Whisper Systems:

[https://moxie.org/blog/gpg-and-me/](https://moxie.org/blog/gpg-and-me/)

<comment><USER10> I would like something better then GPG as well, but at the moment I have a group of contacts that I would like to write GPG with.

If you have a replacement for GPG and E-Mail please tell me what it is.

<comment><USER11> __Possibly __bitmessage.

But adoption is even worse than pgp

</comment></comment></comment></comment><comment><USER12> I need a clarification

"In ProtonMail's one-password mode, the mailbox password is derived from the login password via a one-way cryptographic password hash. The input to this hash includes a salt provided by the server on login but not stored in the client. In this way, compromise of the mailbox password does not automatically lead to compromise of the login password."

This means, if my password is "123hello" then the mailbox password is hash(derived("123hello"),secret_salt) where, hash is an hash algorithm (which one?), the secret_salt is a value stored in the server and never sent to the client, and the derived("123hello") is a password computed using the SRP protocol, which should be the session key explained here [https://en.wikipedia.org/wiki/Secure_Remote_Password_protoco...](https://en.wikipedia.org/wiki/Secure_Remote_Password_protocol), correct? the part of the SRP and on how to genreate the password in SRP is a bit obscure to me, just trying to understand.

</comment><comment><USER13> Nice to see wider adoption of ZKPP authentication.

</comment><comment><USER14> >In ProtonMail's one-password mode, the mailbox password is derived from the login password via a one-way cryptographic password hash.

I wonder what the password change procedure will be when you have several gigabytes of mail in your mailbox? Would you have to download every message, re-encrypt it in your browser and send back?

<comment><USER15> Hopefully the mailbox encryption key is actually static, and they only store it encrypted with a key derived from your login password. If you use two different salts the knowledge of the login pw hash does not yield the mailbox key encryption key.

<comment><USER7> The mailbox encryption key is static. There is no need to re-encrypted all the mail when it is changed. Since the PGP Secret Key is only decrypted in the client browser or app, there is no need to transmit the decryption password to the server.

</comment></comment></comment><comment><USER16> how practical is it to drop GMail for these guys? I'm tied fairly heavily to the Google ecosystem (Chome, Play, Finance, etc etc). They already have a mountain of data on me, but I really want to start taking encryption and privacy more seriously.

<comment><USER17> I didn't miss anything when I left Gmail, but I imagine it depends a lot on how you use email. I switched to Fastmail on my own domain and actually prefer the webmail interface over Gmail.

I mainly use IMAP via Mail.app on my laptop and phone, Pantheon Mail (formerly Geary) on my desktop. I use PGP wherever I can. I haven't received any spam at all yet, so I can't comment on how their spam filters compare to Gmail. I maintain a zero inbox – important stuff gets archived, and everything else is deleted. This means that I don't miss Gmail's search feature as hardly keep any emails. Obviously your mileage may vary here. They also support CalDAV and CardDAV – so all of my notes, contacts, calendar items etc. are synced across my devices.

I've moved from Google completely, and for the most part, I don't really miss them all that much.

\- Search -> DuckDuckGo (I do miss Google here – DDG's search results pale in comparison)

\- Gmail -> Fastmail

\- Maps -> Citymapper and Apple Maps

\- Chrome -> Safari on macOS, Firefox on everything else (my experience with FF is a bit 'meh' – it was incredibly laggy on my work laptop, but runs great on my desktop)

<comment><USER18> Right now, I also try to keep Google as far away from me as I can. Unfortunately, I don't own a domain myself. Have you tried out ProtonMail yourself? If so, do you think that it is a good alternative to a self-hosted server like Fastmail?

<comment><USER17> I have not used ProtonMail myself so I can't help you there I'm afraid.

While I use Fastmail with my own domain, it is not self-hosted. My MX records point to Fastmail's servers.

</comment></comment></comment></comment><comment><USER19> similar to [https://www.caplinked.com](https://www.caplinked.com) 's [http://www.attachd.com](http://www.attachd.com)

</comment><comment><USER20> This all seems to be a web-based application ([https://github.com/ProtonMail/WebClient](https://github.com/ProtonMail/WebClient)). How are the security issues regarding knowing that you're always running that code and that the server isn't compromised and sending altered code? The arguments against server-supplied, js-in-the-browser crypto have been done to death.

Why is this any different, and why am I wrong to dismiss it out-of-hand as (in)secure as simply sending unencrypted data to the server? Why isn't this only an open-source, native app (where I can load a specific, known version instead of whatever is on the server).

> we choose our own primes rather than those used by TLS

Does TLS specify any primes? You can use your own DH primes, SRP primes, and your key is your own prime. Those RFCs recommend primes, but allow the server to use different ones. TLS, SRP, or DH doesn't "use" a single prime, any prime satisfying the requirements in the RFC is acceptable. know it's nitpicking but something about how it was said rubbed me the wrong way.

I would love to know how they communicate between their TLS-SRP layer and their authentication layer. Most implementations are file-based. Did they write a plugin for gnutls or openssl? Did they write their own TLS layer?

I would love for TLS-SRP to be more wide-spread, but this is always the biggest hurdle to adoption in my case.

<comment><USER14> >Why is this any different

Nobody says it's different

>Why isn't this only an open-source, native app (where I can load a specific, known version instead of whatever is on the server).

OK, let's suppose you're using a native app. One day vendor issues an update with some critical vulnerability patched. Unfortunately, another vulnerability (or even backdoor) sneaks into this update for whatever reasons. How is this any different?

<comment><USER20> > Nobody says it's different

They why do all the extra work for no gain in security?

I think the sibling comment address your next comment well.

<comment><USER21> There's a difference between an active attacker and a passive MITM attacker. Doing this for the web app in addition to the native apps helps prevent a passive MITM attack from stealing login credentials.

<comment><USER20> A mitm is an active attacker. If TLS fails, then the mitm could modify the code sent to the end user.

<comment><USER21> That's a limited definition of MITM. That would be an active attack, and yes, this does nothing for that for the web app--the native apps are a different story. However, there are plenty of corporate PCs and other machines with root certs installed in a way that a third party could, and often does, passively record traffic without modification for analysis later. SRP prevents those dumps from containing information that can be used to compromise an account.

<comment><USER20> That is exactly what I'm describing though. The corporation could edit the page to do what they want. To claim otherwise is foolish and really makes me question proton's understanding of security.

</comment></comment></comment></comment></comment></comment></comment><comment><USER22> It should be reminded that emails exchanged between Protonmail and any recipient who use ordinary email server are not secure. In order to achieve security you have to mail with other Protonmail user or use PGP.

<comment><USER23> They have an option to send a secure email to "normal" email addresses which works by sending them an https link to click. You must have a pre-arranged password with the other person for this to work, but it is possible.</comment></comment>


Ask HN: Feature Flags? - <AUTHOR>

Our product is growing in features faster and faster, especially now that we have a larger team. We'd like to do incremental releases and after seeing the FB talk on feature flags we are intrigued by the potential.<p>Do you use them and recommend their use? If so how do you implement them? When do you determine when to remove the code handling the feature flag? Do you do server side and front-end? <comment><USER2> At work we use to use feature flags a fair bit, but switched to using branches instead for development.

For our testing environment, we can access individual branches as subdomains to a testing environment.

This lets the in-progress code be separate from the mainline trunk, while also letting other people easily check out a new feature in a testing environment.

Only once or twice have we used 'feature flags' for trunk code; basically when the feature was ready to go, but may not wish to be activated until the last minute etc.

I can definitely see the advantage though of having feature flags for very high volume environments like Facebook to 'soft launch' projects (eg, to just staff) before making it live.

It's important though for code maintenance that you remove the feature flags after a while (once a project has settled in and won't be turned off), otherwise it can start to become a maintenance problem.

</comment><comment><USER3> Our site (<http://gre.magoosh.com>) serves up content for a variety of exams, each of which is accessible from a single subdomain. Since content is developed for the exams somewhat independently, we have to be able to roll out releases at different speeds per exam, so we needed a solution a bit more complex than just feature flags -- here's the solution I built:

We keep a table of feature releases, each with a reference to the exam, a slug to identify the feature and an number from 0 to 100 indicating their status in the release cycle (100 = disabled, 75 = alpha, 50 = private beta, 25 = public beta, 0 = full release, etc.). Then each user is also assigned an integer which indicates the point in the release cycle at which they get to see features (0 by default). When we want to give them access to a feature, we just adjust their release access accordingly. All this is controlled through the admin interface.

We then use a helper (in views and server-side), feature_active_for?(feature_slug, user) which returns true the exam has the feature enabled and if the release status is less than or equal to the user's release access, so we can do stuff like:

if feature_active_for?(:lesson_videos, current_user)

# use video template

else

# use plain text template

end

This has worked really well so far, giving the non-technical content producers and customer support the ability to manage releases as they test content. However, the biggest advantage is that we can now give customers access to features before their public release to build goodwill after support requests and gather feedback. (we've been giving out a fraction of the refunds that we did before the release control)

I haven't actually removed any of the feature flags yet (we can reuse the release process for each other exam that we develop content for) but I'll probably remove one when it if becomes an integral part of the product across all of our exams. It would actually be pretty easy to just add to the helper to intercept release status checks and ease up on database requests.

This is probably all a bit more complicated than what you'll need, but I hope it helps.

</comment><comment><USER4> I work for Cheezburger Network. We use them a lot via lots of if(FeatureFlag.IsEnabled("foo")){ /* Show the feature! */ }. They're easy to see if you can remove the conditional. You just check if the feature is enabled in production and if it is and it's been there awhile delete the flag. And yes we do feature flags in both Javascript and C# side.</comment>


Google Wave Aha moment, with:public is Awesome - <AUTHOR> http://www.victusspiritus.com/2009/10/13/google-wave-aha-moment-withpublic-is-awesome/

<comment><USER2> I feel like you already have to know what with:public is before reading this. I got 1.5 paragraphs in and stopped since I had no idea what was going on.

<comment><AUTHOR> Well then I owe you a better explanation. If you haven't used Google Wave before I should first state that there is a search box in the center window. Simply by typing in with:public it searches all public waves and displays them. Then you can scan through waves of interest and join in where you like.

Additionally you can add extra qualifiers like with:public HackerNews and get waves like the HackerNews wave.

Nothing Earth shattering yet, but there is definitely some potential for people connecting which is always fun (at least for me) as well as building tools (robots) for automagic wave processing.

</comment></comment><comment><USER3> I get the impression that public waves were a quick hack that Google created to give new users someone to interact with while the network is new & small. (If you just got onboard, it's likely that you only have one friend, and that could get boring very quickly. Furthermore, enabling mass public interaction would give theme some stress situations to test how their infrastructure scales, and how their GWT client scales in the browser.) The strange fake contact that one has to add as a wave participant is one indicator. Another is the fact that with:public is undocumented.

Once the service is completely open, it's unlikely that this hack will be needed any longer. I wouldn't be surprised to see the email@example.com user retired after a while, anyway.

<comment><AUTHOR> I hope that the public pipeline is maintained as long as possible. The searching power available from such a stream is quite rich with opportunity.

</comment></comment><comment><USER4> I find public waves to be too much like a message board, but harder to follow.

<comment><AUTHOR> Good point, thanks for chiming in.

While they do resemble other forums, the drag and drop connections, and potential utility addins, as well as lightning fast search are drop dead sexy.

I can't normally think up a new tool for a forum I hang out on, and have them host it.

It's a distributal protocol. We can host our own servers which may require search like status propagation. I wrote it up not too long ago, but messages like "hey have you seen this string?" would aid decentralized search.

</comment></comment><comment><USER5> I have to say this is pretty awesome. I just created a public wave with a question in regards to the Reuters Newswires pricing structure, and the first people already replied.

<comment><AUTHOR> Now that's a quick response. Monitoring the public channel for information relevant to your interests is a great way to use it.

</comment></comment><comment><AUTHOR> Followed up with embed example and how to: <http://news.ycombinator.com/item?id=883551>

</comment><comment><USER6> I found it akin to having 100 IRC chatrooms open at one time. It was a bit too overwhelming in that new conversations kept being found/updated/changed.

<comment><AUTHOR> Oh my. The full pipeline could be a litte much.

I added additional words to filter by like HackerNews and reddit.

<comment><USER7> I just got my invitation today- there is no way with:public will be usable once anyone can join. I can't even keep up as it is. Maybe it needs a pause button.

<comment><AUTHOR> I believe the data pipeline will be quite valuable, and strong filters (Google can search like a bandit) will help you find information relevant to your interests.

</comment></comment></comment></comment><comment><USER8> Where was documentation on with:public hidden? I perused the starter waves, but didn't see anything about that or the group: prefix.

<comment><AUTHOR> I never found any Danno. Someone else pointed me to it.

</comment></comment><comment><USER9> that is sick, thanks for the tip.

<comment><AUTHOR> anytime</comment></comment>


The Robots Sent into Fukushima Have 'Died' - <AUTHOR> http://www.newsweek.com/robots-sent-fukushima-have-died-435332 <comment><USER2> No real info about the robots in question.</comment>


Ask HN: Difference between Heroku and Web Hosts - <AUTHOR>

What is the difference between the two? On its about page Heroku states that it host web apps, but can't a web site be part of a web app? What is the difference? <comment><USER2> There is no particular difference between a web "site" and a web "app", they are both very broad definitions that usually boil down to the same thing - very vanilla CRUD database operations (create, read, update, delete) behind a pretty page.

The difference between Heroku and most web hosts is what happens when your requirements increase.

With a conventional web host you will scale vertically which means at each growth milestone you move up to the next plan eg starting on a $5 basic shared plan and eventually growing up to the $10 and $20 and $50 and $100 per month plans and finally separate db and web servers.

With Heroku you design your application to scale horizontally so you add more capacity (dynos) and that capacity means you can support x% more traffic unless other bottlenecks get in the way like database load which Heroku and many of their partners also provide in scalable fashions.</comment>