Ask HN:  Why do audience members cheer wildly in technology keynotes? - <AUTHOR>

Given my experience with academic conferences, I find this behavior in technology keynotes to be downright bizarre.
Obviously people don't behave in this way in academia.  What's different here?
Are audience members told to behave in this way?  Is it peer pressure?
And why do they get all excited over the most trivial of things?
Could it be that the more they cheer as a group, the more money they will make (e.g., by getting more people to buy/use the products/services mentioned in the keynote and later their software that is associated with those products/services)? <comment><USER2> On earth, humans cheer wildly when they see things they like. This could be anything from a man throwing a ball into a net, to a useful new operating system feature. It's considered a way to express approval, especially when gathered in a crowd, where shouting words would be less effective.

See also: booing.

</comment><comment><USER3> All the comments posted so far are right-- they explain why people might cheer. But nobody has really addressed the very real difference between technology and academic venues (the original poster's question).

I've only been at one academic meeting where people really let loose and cheered. It was in the late 1990s, at a conference on energy efficiency. A presenter brought a pretty fancy bike up on stage and talked about riding it rather than driving. Somebody in the audience shouted out, "Sure, but what did the bike cost?"

There was a moment of pause while everybody recognized the presenter had probably a $3000 bicycle up there. But he hoisted it over his head, stepped back up to the mike, and said, "I'll tell you what it cost... What I was willing to pay!"

The whole audience erupted in a sustained wave of cheers. It was, as other commenters have noted, an expression of approval, an outlet for their passion, and just plain fun.

In some ways, though, I think the setup for that wild cheering was the conflict that it resolved. If his presentation had started out with "This is my bike. It cost a lot, but I was willing to pay it..." I doubt anybody would have cheered. Maybe academic conferences tend to discourage expressions of joy exactly because they tend to formalize conflict, to steer it down certain accepted lines? Whereas tech presentations probably have a lot less inherent conflict that has to be channeled in order to keep it productive?

</comment><comment><USER4> Some significant portion of the audience's life is just about to change significantly - and they can already sense the downstream bliss. I downright cried in joy the first time I saw OS X terminal.app's ability to dynamically resize linewraps (phoo on you secureCRT), and Terminal Tabs that detach, no preset max-column-width, or even line-buffer! I was ready to dance for Joy! Imagine being hit with a whole host of those features - It would be a hard person indeed who could hold in all of that emotion.

<comment><USER5> Here's me hoping you forgot your <sarcasm /> tags

<comment><USER6> Here's me thinking you don't spend that much time in a terminal :)

<comment><USER4> Sounds like an HN Poll for OS X users How many hours a day do you use Terminal.app (as measured by the total time of day you are looking at the screen and the foreground application is Terminal.app)

            A) < 30 Minutes
            B) 30 Minutes - 2 Hours
            C) 2 Hours - 6 Hours
            D) 6-10 Hours
            E) 10 Hours+

I'm usually in category D, but I've certainly seen a few E class days.

Seriously, Terminal.app is probably about 50% of the reason I use OS X instead of Windows XP - I have two keyboards and two 30" monitors sitting in front of me, so the choice really is mine. (Windows XP wins on the Microsoft Outlook Calendar + Visio side of things)

And so, if you are spending upwards of 30 Hours/week with an application, and something just made it even 5% better - wouldn't you want to express your appreciation at positive changes?

<comment><USER6> Heh, too true. I often have 10-20 tabs open, in 2-4 windows, and some days spend 50%+ of my day in Terminal (the rest in Vim/Mail/OmniWeb). I'd go crazy if I had to use Cygwin, PuTTY, or even XTerm/KTerm/GTerm.

</comment></comment></comment></comment></comment><comment><USER7> I've wondered the same thing! During Google's IO conference, the speakers expected and encouraged applause. Apple conferences are an even stronger example.

It feels phoney, but perhaps it isn't. I don't think the thought process is complex enough to involve considerations of financial benefit from cheering.

My theory is that there is a critical mass of "fans" of the company (Google, Apple, etc), and they are very enthusiastic about new features/products while the rest of the crowd claps out of reflex/habit.

<comment><AUTHOR> Maybe this critical mass consists mostly of paid plants?

<comment><USER8> No. I've cheered for new features or things I thought were particularly cool, and if I'm a plant then I'm seriously underpaid.

</comment></comment></comment><comment><USER9> Joy. It's a human emotion.

</comment><comment><USER10> It's fun. Try it.

</comment><comment><USER11> Amichail, you at once come up with the most poignant and hilarious observation/questions on this board. This is probably unintentional, which adds to the level of entertainment. Please continue with these types of submissions.

</comment><comment><USER8> Because for many of us, technology isn't just our job - it's a defining characteristic of who we are.

And given that many of us debate operating systems and programming languages, discuss tools and improvements, and learn new technologies in our off time, _as fun_ \- well, given all that, I don't think expressing that passion at a major event is all that peculiar.

</comment><comment><USER12> Damn, these comments make us sound like a bunch of robots :)

<comment><USER13> "Geeks cross into uncanny valley. Very close to human behaviour. Described as 'unnerving' by industry pundits".

Server monitoring software that cheers when good things happen, boos when bad things happen, and gasps when major changes happen, that would be interesting. Not "play cheer.wav" but something more crowdy and cumulative.

</comment></comment><comment><USER14> why not?

</comment><comment><USER13> Why go to a conference when you could watch the news on the net?

Atmosphere. A sense of belonging, and 'being there'. A band comes on stage and plays a song you like, you cheer them. A company representative comes on stage and announces something you like, you cheer them. The events are structured to be similar.

</comment><comment><USER15> hello, Mr. Spock

</comment><comment><USER16> I find the behavior a bit odd myself but liken it to the same extreme passion that some people exhibit during professional sporting events.

</comment><comment><USER17> It's today's TV generation used to seeing and hearing everything wildly applauded whether it deserves it or not. Every play ends with a standing ovation. Every homerun requires a 'curtain call'. Every song sung has throngs screaming to the point where you wonder if anyone is actually listening.

Serious students of the technology are listening, not applauding or "high fiving" themselves for doing so. It's childishness at best. Low-brow at worst and more appropriate at some hillbilly bar.

</comment><comment><USER18> Because they're expecting to get a goodie bag at the end of the presentation and are expressing their desire for it to contain a lot of expensive new stuff.</comment>


Conway's Game of Life in one line of APL - <AUTHOR> http://se.youtube.com/watch?v=a9xAKttWgP4

<comment><USER2> I've written utilities in APL - fantastic for getting something done once you've wrapped your head around it. I've done some fun stuff.

I've _never_ been able to read anything non-trivial in it.</comment>


Ask HN: Best practices for quickly selling a small company? - <AUTHOR>

I have a company that makes less than $250k/year in a niche market. I have an offer to co-found a different, unrelated company. If I were to accept the offer, I would want to move quickly. What are best practices for placing a value a company of this size and for structuring a sale?
My goals are:
- get out quickly
- provide continuity for existing customers
- have minimal ongoing responsibility
- not leave money on the table (but otherwise, this is secondary to the first three goals).
Our stats
- sole founder
- 30% growth last year and this year
- 80% of revenue comes from professional services
- three other workers are on 1099 and amount to 1.75 FTE
- sales come from word of mouth
- our professional services are very repetitive and consist mostly of: account management, advice, and web production.
- cost of "goods", including providing the professional services, hosting, and infrastructure are 25% of revenue. Everything else goes to software development.
- our customers include the major association for this niche, which gets us in front of 2000 potential customers each year <comment><USER2> You might be able to expect a 5X annual profit sale if you could manage to find a competent investor who wanted to grow it.

It's unclear though from your COGS line though if there really is any actual profit, or if you're just managing to cover salaries and necessary R&D efforts.

The best way (IMO) to expedite a sale would be to:

\- Have accurate accounting data for the last 5 years readily available and organized.

\- Set a realistic price, with some justification of the price ("I am looking for $500K based on year over year sales growth for the last 5 years and a $100K bottom line profit last year. The market is Y and this brand has the ability to grow to own X% of Y based on Z. " Etc.)

\- Be available to answer questions

\- Offer to be available (for free or on retainer) for the first 6 months after acquisition to help with any transition items.

...just some thoughts...

<comment><AUTHOR> Thanks! There hasn't been any real profit although there's a story to be told about how to make a profit. Most of the necessary R&D has already been done.

</comment></comment><comment><USER3> Well ... one approach would be to find someone like my father (who's 77 now and happily retired). Give him a 1/3 commission, agree on the minimum terms (i.e. the above plus a price) and stand back.

However, anyway you look at it, unless you're willing to spend some number of months to do it right, you're not likely to get a good deal. It's always possible, but I wouldn't count on it.

And that's one reason to hire a specialist, someone who can play the game without conveying that you want out yesterday. And I've seen my father do this sort of thing, it can be done.

Good luck!</comment>


New Tesla Model S Now the Quickest Production Car - <AUTHOR> https://www.tesla.com/blog/new-tesla-model-s-now-quickest-production-car-world <comment><USER2> > The Model S P100D with Ludicrous mode is the third fastest accelerating > production car ever produced, with a 0-60 mph time of 2.5* seconds. However, > both the LaFerrari and the Porsche 918 Spyder were limited run, million > dollar vehicles and cannot be bought new.

<comment><USER3> > * Expected value using max power mode and Motor Trend benchmark

Suggesting that this is expected value, and not observed performance?

Edit: Or they are suggesting that you could potentially reach that value in "ideal" conditions, using the Motor Trend method to adjust some observed values to this normalised time?

</comment></comment><comment><USER4> This last bit is an interesting statement,

"While the P100D Ludicrous is obviously an expensive vehicle, we want to emphasize that every sale helps pay for the smaller and much more affordable Tesla Model 3 that is in development. Without customers willing to buy the expensive Model S and X, we would be unable to fund the smaller, more affordable Model 3 development."

<comment><USER5> I was about to quote that myself. While it's true that their luxury models help fund newer models, it's rather odd to state that in a press release. It comes across as: "Please pay too much for this vehicle and help subsidize someone else's future purchase."

<comment><USER6> It seems a strategic error from a sales perspective. Why call attention to the fact that the car is expensive? They could have pointed out that the car funds the Model 3 without highlighting the high price.

<comment><USER7> I get your point, but I think they are going for a slightly different strategy here. This is the highest trim level for them, produced in limited quantities and is being sold in part based upon its relatively exclusive nature.

Highlighting the price difference doesn't always hurt luxury products.

</comment></comment></comment></comment><comment><USER8> What matters to me, and some other car guys who don't own banks, is that the Tesla is capable of doing this regularly and without breaking things. Most don't realize how delicate supercars are in real life. The Ferarri Enzo famously could only do full acceleration from a stop three or four times before needing new clutch plates, even with launch control. Electric motors are just better at the standing start. That isn't so much Tesla as the nature of the technology.

But do the race in cold weather, or over any distance (it doesn't go 300+miles while racing) and things would be very different. So too is the nature of the tech.

</comment><comment><USER9> I find the range improvement more significant.

Anyone have info as to if the power density was increased, or they just crammed in more cells into the battery?

I'm hoping for a 400 mile range car in two years... for half the price.

Also, does this imply that the battery costs roughly 20,000? or that's with a "rebate" for recycling your old one?

<comment><USER10> Better/more batteries, this is a 100kWh car, vs the P90 which is a 90kWh car. Early battery packs had the cells spaced further apart (presumably to prevent chain reaction fires) as they have gone along they have made denser battery packs. I don't know if that is because they have better inter-cell insulation, a better handle on battery discharge, or additional safety data which helps them better estimate their margins for error.

</comment></comment><comment><USER11> I wonder where they're getting 315 miles of range from in the P100D. The P90D has 270 miles of range, or 3 miles/kWh. For 100kWh it should be 300 miles of range. At 315 miles of range the P100D is 5% more efficient than the P90D.

If the upcoming 100D is also 5% more efficient than the current 90D, that car would get somewhere around 343 miles of range.

<comment><USER12> Probably because the batteries are not discharged to zero, so there is a "floor".

If the floor is X kWh, then we can solve for X based on these two ranges assuming the kWh / mile consumed is the same ratio, r.

        r * (90 - X)  = 270
        r * (100 - X) = 315

Solving these two equations gives me X = 30 kWh as a fixed reserve in the battery packs assuming r = 4.5 mi / kWh.

<comment><USER13> 4.5 miles/kWh is hugely optimistic, and a 30kWh reserve is highly unrealistic. Tesla's range numbers are based on roughly 3.3 miles/kWh (which is reasonably realistic) and the floor is maybe 5kWh.

I can't explain the discrepancy, but it's definitely not just the floor. Either they've made some sort of efficiency improvement, or the difference between the two battery packs is more than 10kWh and they've just rounded off the figures.

</comment></comment></comment><comment><USER14> Motortrend tested it at 2.6 secs which ties it with a few other production cars in this wikipedia list [https://en.wikipedia.org/wiki/List_of_fastest_production_car...](https://en.wikipedia.org/wiki/List_of_fastest_production_cars_by_acceleration#By_0.E2.80.93100.C2.A0km.2Fh_time_or_0.E2.80.9360_mph_.280.E2.80.9397.C2.A0km.2Fh.29_.283.0_seconds_or_less.29.5Bi.5D)

"Many elements change how fast the car can accelerate to 60 mph. Tires, elevation above sea level, weight of the driver, equipment used for testing, and surface of testing track all play a big part in these times."

<comment><USER15> True, however I would point out that elevation should have absolutely no impact on the performance of electric vehicles.

<comment><USER16> Air density and temperature should both have an influence on the performance of electric vehicles, and both change with elevation.

<comment><USER17> Maybe on a very hot day cooling would become a factor on the track, but for a single 0-100 run air temperature should be irrelevant. Electric cars don't need to ingest hundreds of grams per second of air to make high power outputs. Unless you're referring to the impact of air density on aerodynamic drag, which should be negligible at such low speeds.

<comment><USER18> Home runs travel further at Coors Field. Field goals are longer at Mile High. Sprinters turn in faster times at higher altitudes. You can bet that the air density will affect vehicle acceleration tests significantly.

<comment><USER17> Drag scales with the square of velocity. A 110 mph home run experiences vastly more drag than a car traveling 30 mph on its way to 60 mph. The ball might fly 18% faster in Denver than it will at sea level, but the car isn't going to accelerate 18% faster.

<comment><USER19> There's a whole raft of other aspects. Temperature will affect traction, for example. Similarly, the pressure differential between the tyres and the atmosphere will change their performance similarly to pressurising tyres to a different pressure at sea level.

There's a whole raft of influences that altitude may have that aren't immediately apparent. To say it has 'absolutely no impact' is simply wrong.

</comment></comment></comment></comment></comment></comment></comment><comment><USER20> I wonder how well a special version of the Tesla Model S would do on the Top Gear track, if it reduced its battery weight to the point where it could just barely complete the course? The battery weight is its biggest problem as a track car.

<comment><USER21> Interesting idea, why not make the battery in segments and removable. Weight affects range too, so why not make the battery as 4 segments, and if you're just going to have a 30 minute daily commute, you could take out 3 segments and have enough range while saving weight, and the environment. If you want to go for a weekend trip you'd plug in the other segments.

Obviously it'd be a bit of a nuisance and probably the segment that is always in the car will die first, because it'll have the most cycles. Unless the software controls which segments you can remove and do some wear-levelling.

<comment><USER20> The battery is already removable. I could see a Tesla battery swap machine at a track with lightweight "track batteries."

</comment></comment></comment><comment><USER22> I like this commercial for an electric smart car which demonstrates the importance of acceleration vs top speed: [https://www.youtube.com/watch?v=b1iJJZfB7i0](https://www.youtube.com/watch?v=b1iJJZfB7i0)

</comment><comment><USER23> Well, really, who cares how quick it is? For the average Tesla buyer the speed upgrade is mostly a novelty. Just because it can accelerate doesn't make it a hypercar, sportscar, or even sports sedan alternative. What really makes this option is the range, which is really outstanding.

<comment><USER24> The average Tesla buyer does not pay for ludicris mode, or probably even the 'D' submodel.

<comment><USER25> I think you mean 'P', but yeah. The non-P models are most popular.

</comment></comment></comment><comment><USER26> This line interests me here:

>"While the P100D Ludicrous is obviously an expensive vehicle, we want to emphasize that every sale helps pay for the smaller and much more affordable Tesla Model 3 that is in development. Without customers willing to buy the expensive Model S and X, we would be unable to fund the smaller, more affordable Model 3 development."

IN other words: Hey! they are expensive but please help other people buy inexpensive cars by buying this expensive one yourself. Bit wierd!

<comment><USER27> I don't get why everyone is reading this line negatively.

When I read the headline my first thought was "Oh, that'll help with the cashflow problems for Model 3's ramp up."

Tesla buyers make their choice on strong feature differences. The company puts very little effort into telling people what to think of their product with traditional advertising or messaging.

IMO, the primary audience of press releases like this (from Tesla, not generally) are investors. Consumers will get this news two or three levels of indirection later ie some journalist compressing and regurgitating this release, or word of mouth.

<comment><USER26> Well I can understand your view but looking objectively this message does not align the price a customer pays with the product itself (Model S P100D in this case) but rather aligns the value to a different product's prospective benefits. (Model 3 in this case which would change the world by creating a sustainable transportation.)

I think a customer naturally would try to align the value of a product to the product itself. Just think: would anyone pay expensive price for an Honda Accord if Honda tells:"Buying an expensive Accord would help us fund a new version of Civic."

<comment><USER28> It aligns to the _brand_ , not the product. And "buying a Tesla" has become a consumer aspiration, so they're wise to keep milking it.

</comment></comment></comment></comment><comment><USER29> _Model S P100D has four doors, seats up to 5 adults plus 2 children_

Could not verify this. Looks like it seats 5, 2 in the front and 3 in the back. What am I missing?

<comment><USER30> It has the option to add two seats in the "trunk" space. Like so: [https://s-media-cache- ak0.pinimg.com/564x/6f/bc/08/6fbc08280...](https://s-media-cache- ak0.pinimg.com/564x/6f/bc/08/6fbc082806e8c94aaddeac06ae46ffae.jpg)

<comment><USER31> That looks like a big liability.

Imagine dad hammers it with the kids belted in a little loose. Their heads look like they could smash the rear window.

<comment><USER13> There are a ton of ways to badly injure your kids by being irresponsible in any car. This doesn't really add anything new there, and the fact that they're rear-facing and permanently installed in the car should make them a fair bit safer than typical add-on child seats.

<comment><USER31> 2.5 seconds 0-60 with the kids in the trunk doesn't add anything new?

Tesla already has liability with the push of "auto-pilot" as a marketing term. Boats have auto-pilot. Tesla's do not.

<comment><USER13> Any car that's safe for the road can already maneuver hard enough to injure unsecured passengers in at least three directions. The rear seats and high acceleration add one more direction, but also largely subtract the opposing direction, so it's a wash. You have to accommodate your passengers with how you drive in any car.

</comment></comment></comment></comment></comment></comment><comment><USER32> I was hoping this was in regards to speed of production. Especially given Musk's comments recently about factory output.

</comment><comment><USER33> I wonder how much time they're saving by simply not having to shift gears? That could be a second right there.

<comment><USER34> The cars they're competing against largely have two clutch packs, allowing the shift to take milliseconds.

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

</comment></comment><comment><USER33> I wonder how they can get that much power out of the battery. I'd think they'd need to use capacitors?

<comment><USER35> It's possible to draw a _lot_ of current from a lithium battery for very short periods, as well have pull a lot of current through a conductor for short periods.

I remember doing the calculations for some of the batteries I used in RC planes and being surprised the battery was capable of delivering 4kW continuously for minutes.

<comment><USER36> Multi-rotor enthusiast here-- I can confirm this statement! My 5" crafts pull up to 80 amps at full throttle and a mere 1.3ah 4 cell battery pack can generally keep up, albeit with some localized heating and voltage sag.

</comment></comment></comment><comment><USER37> I want to know what's its range when driven at maximum speed...

<comment><USER13> You'll achieve the official numbers at around 70MPH in mild weather. The top speed is a bit over 2x that speed, so you'd use something like 4x more energy per mile. You'd expect the range at top seed to be _roughly_ 80 miles.

</comment></comment><comment><USER38> You have got to be kidding me. Tesla seriously just named their car in homage to Spaceballs? How silly!

[https://www.youtube.com/watch?v=ygE01sOhzz0](https://www.youtube.com/watch?v=ygE01sOhzz0)

<comment><USER39> Originally the vehicle models were going to be S, E, X. They changed them to S, 3, X...

<comment><USER40> And the current stylized "E" and "3" are the same symbol.

Seems Ford owns the trademark "Model E", hence the "3". [http://www.fool.com/investing/general/2016/03/18/tesla- motor...](http://www.fool.com/investing/general/2016/03/18/tesla-motors-incs- model-3-logo-revealed.aspx)

</comment></comment></comment><comment><USER41> A McLaren F1 w/ 2.2 second acceleration isn't considered a production car? Or the other one that replaced it in Guiness?

<comment><USER42> Where did you find the McLaren F1 had a 2.2 second acceleration time? Most citations I could find were in the mid 3 second range.

<comment><USER41> I know I read it back in 2000. It must have been a misprint given the sources I'm seeing are saying something different. Thanks for catching that! :)

Btw, as a thanks, here's you one that's still pretty amazing but not production:

[https://www.youtube.com/watch?v=0CtHpt05gLc](https://www.youtube.com/watch?v=0CtHpt05gLc)

</comment></comment></comment><comment><USER43> The original title says "quickest" not "fastest." They're two very different claims, and only one of them is remotely true here.

<comment><USER44> 0-60 is what matters. Top speed is not a bottleneck anymore unless you are track racing. It has a 0-60 that is comparable to a Bugatti Veyron.

<comment><USER45> Eh. What "matters" is pretty debatable when it comes to cars. I very rarely accelerate from 0-60mph in one single acceleration, same as I rarely reach top speed.

<comment><USER46> Most people accelerate a lot more than they take a few laps on a track though...

<comment><USER47> > _Most people accelerate a lot more than they take a few laps on a track > though..._

Lap times give a better "all-around" indication of performance: speed, handling, acceleration.

<comment><USER46> For production cars top speed doesn't matter, after you get past highway speeds it is meaningless. Maybe it's me, but I'd rather a car that goes 0-60 really fast and can only go 100MPH than one that goes 0-60 slower but can go 200MPH.

<comment><USER47> And I'd like one that can corner on rails, which is arguably more valuable than both speed _and_ acceleration (after all, acceleration, after a certain point, is also useless).

Hence why lap times are an interesting metric.

</comment></comment></comment></comment></comment></comment></comment><comment><USER48> According to [https://en.wikipedia.org/wiki/List_of_fastest_production_car...](https://en.wikipedia.org/wiki/List_of_fastest_production_cars_by_acceleration) this puts the Model S on par with the Bugatti Veyron and Porsche 991 Turbo S

</comment><comment><USER49> While impressive - it would be more impressive in my mind to see the USA embrace walking, biking, and public transit in a meaningful way - rather than fetishize the wasteful consumerism that is "ludicrous mode".

</comment><comment><USER50> Owning a new 911 and even paying extra for the sport exhaust noting that there are people who actually like the sound of the engine as adding to the experience of speed. (Also the torque curve which I assume with tesla is somewhat constant). Not to mention the manual transmission which obviously doesn't exist in an electric car. Driving even a 911 with the PDK isn't the same experience although performance wise it is better than the manual.

<comment><USER39> You realize that the Tesla is a manual right? There is only 1 gear :)

</comment></comment><comment><USER51> Wait, whenever I see a performance claim with an asterisk, it kind of makes me want to read the footnote:

> _" \- Expected value using max power mode and Motor Trend benchmark"_

Oh, expected value? Hm, that's a new one. And for what, a 0-60 time?

I think of quickness a lot differently than a simple drag race. If a Tesla can can consistently out drag race 0-60 in _actual value_ and then, for grins, lap the 'Ring faster than a Skyline GT-R, that's dang quick! But expected? Sorry, I want to groan at that.

<comment><USER52> What do you mean by actual value? There's going to be variance in each run so I'm assuming they mean expected value as in "average" time.

[https://en.wikipedia.org/wiki/Expected_value](https://en.wikipedia.org/wiki/Expected_value)

<comment><USER53> The expected value in this sense means "it's not been verified, this is our projection".

</comment></comment></comment><comment><USER54> Wake me up when I can charge the battery to 100% in 2.5 seconds anywhere.

<comment><USER55> "I'm not interested unless this is the most innovative thing to ever happen by an order of magnitude". Okay good luck with life mate.

</comment></comment><comment><USER56> Actually this is no suprise since a electric car doesn't need to convert mechanical energy back and forth. It only needs to convert the electricity to mechanical energy once, so that means that the power is near instant (way higher startup turning moment), while on a gazoline motor it needs to "warm up". Also some vehicles have multiple motors peer wheel, that is not possible with a non electric car.

</comment><comment><USER57> As far as I know the Nissan GTR is the fastest production car in the world with 0 to 60 in 2.7s. Tesla with the ludicrous is only 3.0s. I could be wrong.

<comment><USER11> You are wrong [https://en.wikipedia.org/wiki/List_of_fastest_production_car...](https://en.wikipedia.org/wiki/List_of_fastest_production_cars_by_acceleration)

<comment><USER58> > Tesla Model Truck P100D w/Ludicrous Speed Upgrade

Someone was too eager to edit the wiki page.

oh look, the model is better than a second slower on the 1/4 mile than the Ferrari/Porsche. Slower than the Audi R8 V10 too.

<comment><USER55> Just to be clear, its 2016 and you're snarkily attempting to put down an electric car that costs ~100k and does 0-60 in 2.5 seconds because its a second slower on the quarter mile than a Ferrari that costs >10x as much and isn't electric?

sigh.</comment></comment></comment></comment>


Ask HN: What should I do? - <AUTHOR>

I've been making a game for iOS and have recently made some pretty good progress. After I release this game, I'm going to start working on a social app which I have been planning for about 6 months on sketches and notebooks.
There is an app that has a similar purpose to the social app I've been wanting to make, although they don't seem to make it that good and it seems a bit cluttered. Theirs has recently made #50 in the category as well.
I would like to work full time but being 16, I've got a lot of things to do for school right now.
What do you think I should do? Keep working on the game? Ditch the game and work on the social app? Or focus on something else for the social app?
Thanks <comment><USER2> Try to release the game before moving on to the social app. If there's one thing I regret from your age (and later), it was not making shipping my priority.

<comment><USER3> Agreed. Ship it for the sake of shipping it and using it as a portfolio piece. I remember one app in particular that I spent a LOT of time on including meetings with others, etc and I never launched it. It still makes me mad and haunts me.

So if you're close to launching the first app, launch it for the sake of launching it and seeing a project all the way through.

</comment></comment><comment><USER4> There's a lot of value in the follow-through from shipping. I don't want to make too many assumptions based on your age, but if it's your goal to get better at this, I'd encourage you to release, learn, and iterate before you shift your focus to something else. See if you can make it successful; if you can't, have a better reason that "I gave up", and you'll be the wiser for it.

</comment><comment><USER5> Which project is grabbing the majority of your psychic bandwidth and gives you the most energy? Which one represents the greater intellectual challenge?

</comment><comment><USER6> Ship it and break it best way to go :)</comment>


Tragedy Of The Social Gaming Commons: A Blueprint For Change  - <AUTHOR> http://www.techcrunch.com/2009/11/03/tragedy-of-the-social-gaming-commons-a-blueprint-for-change/ <comment><USER2> Rampell is correct in calling for some sort of regulation and its just a matter of time before someone steps up to the plate. Just like any other profession, this needs to be regulated as well. Internet has to become a completely legitimate source for all advertisers and consumers in the long run.</comment>


Show HN: Minimalist HN reader with material design - <AUTHOR>

Hello everyone!, this is a app I have being working on recently. I know there are number of HN readers on android. But couldn't find a one suitable for daily use. So I started developing this app. News articles, comments open in default browser of the device. Click on title of the item to open the article and anywhere else to open comments. Pull down to refresh. Swipe left and right to change the tabs. This is only the first phase of application. Lot of functions yet to be implement (you can read more in Google play listing). Before developing further I would love to have some feedback. BTW I'm a CS undergraduate.Thank you.
Image :http://www.kasungamlath.com/assets/hnyc_framed.png
Application :https://play.google.com/store/apps/details?id=com.kasungamlath.hackernews
Any feedback is appreciated, thanks! <comment><USER2> Haha, saw this while working on my own android client!

Some pointers:

* Your story list is incredibly crowded and the text/background colors are too similar.

* Your store screenshots: don't need the Pull to refresh image (which, by the way seems like the wrong color). Also, don't know what the image with the empty list items is.

* The story number seems unnecessary, and has too much priority on the list item

Looks like a good start though, let me know if you've got any questions!

<comment><AUTHOR> Thanks for the feedback.

* I was trying to imitate the web interface. That's why it seems crowded. I agree it should change.

* I was trying to get the screenshots of functionality since I only have one screen yet. (color changes after each cycle)

* Story numbers won't make the next release.

Thanks for the pointers. Do you mind sharing your client? Btw any pointers on how to get more feedback?

<comment><USER2> Ha! The web interface is probably not the best interface to emulate, especially not for mobile. If you're attempting to utilize Material Design, you should take a look at the metrics guidelines for creating a pleasing UI on the device.

I found that I got some good feedback via /r/androiddev and /r/android (once I got the client to a presentable state). My client: [https://play.google.com/store/apps/details?id=io.dwak.holoha...](https://play.google.com/store/apps/details?id=io.dwak.holohackernews.app)

and source: [https://github.com/dinosaurwithakatana/hacker-news- android](https://github.com/dinosaurwithakatana/hacker-news-android)

<comment><AUTHOR> Cool. I tried your app and went through the reddit posts too. I guess I'll post in reddit after fixing the current issues in few weeks(Have exams in next 2 weeks). Few more questions though.

* The login function isn't still available in official API?

* How did you promote your testing community(g+ page)?

* How are the donations coming?

<comment><USER2> * Login isn't through the official API, I just scrape what the website does

* There is an AlertDialog on the first run of the application that lets the user know about the G+ community

* Donations haven't been publicized yet (I only added the links a couple of weeks ago). I may publicize them soon, as the Heroku instance I'm running the server on may need to be moved into a pay tier.</comment></comment></comment></comment></comment>


Silicon Valley's Peter Pan Syndrome vs. The Aging of Aquarius - <AUTHOR> http://fortune.com/2016/07/10/silicon-valley-google-age-bias-discrimination/ <comment><USER2> >If the accusations against Google are true, the company has clearly offered exemptions to its 40-something founders Larry Page and Sergey Brin and its 64-year-old executive chairman Eric Schmidt.

Stopped reading there. The author doesn't understand what average means.</comment>


Ask HN: How does a parent with a day job participate in Y Combinator? - <AUTHOR>

A share of $15-20k should certainly cover one's expenses for a YC season but at the end you're jobless and likely not yet profitable with your fledgling startup.  Does a founder in the aforementioned situation have to set a personal deadline of "by the time YC ends" to either raise more funding or go back to a regular job?
Obviously things are easier for singles with little to no personal expenses or for folks with some personal seed money, but I'm sure there are creative solutions for people like myself with more responsibilities keeping them from diving headfirst into YC.
Please share if you have some tips. <comment><USER2> If you save some money in advance, you should be able to add at least a few more months of self-funded runway before you need to find outside investors. If you have a spouse, their salary (and group insurance!) can pay the bills, especially if you can reduce your expenses.

<comment><AUTHOR> Saving money is certainly a good goal - perhaps after hours contracting with related technologies is the efficient way to build up a cushion for your startup.</comment></comment>


Exercise Is ADHD Medication - <AUTHOR> http://www.theatlantic.com/health/archive/2014/09/exercise-seems-to-be-beneficial-to-children/380844/?single_page=true <comment><USER2> Unpopular opinion time: I am sure that 90% of people with ADHD do not have an actual neurological disorder that prevents them from focusing. They simply lack the skills to do so.

Focusing is a difficult skill, if you do not have it, it takes a degree of awareness to learn it again.

I went though a serious period of stress when I was 15-18, cancer, unstable home life, near homelessness. And I asked a psychologist for ADHD drugs because I was a seriously smart kid who had troubles focusing. Ironically I lacked the focus to chase a psychologist into ticking the various ADHD boxes and just started buying plain old street speed of the Silk Road, which I responded very well to, and was able to study again.

Eventually those problems in my life began to dissipate, and I started to focus again on sleep, eating, exercise and importantly controlling anxiety. I run about 35 miles a week right now (50 minutes to work a day, plus ten minutes to stretch off) and my focus is very good.

Personally, I do not know anyone who takes ADHD drugs and takes care of their sleep, diet and anxiety. Those that try to address their anxiety take benzodiazepines.

I do not think that ADHD as diagnosed in most people is a real disorder. You are an outlier if you do not focus better on controlled dosages of stimulants. _You are not special if you focus better on stimulants._ Doctors just do not have the time to find out what is actually causing a child to have issues focusing. So they just prescribe stimulant drugs.

<comment><USER3> > I do not think that ADHD as diagnosed in most people is a real disorder.

Undiagnosed and untreated ADHD (which is underdiagnosed and untreated in adults and especially in women) can be a debilitating condition that will fuck your life up deeply, and there's ample evidence about this from peer-reviewed medical journals ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4195639/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4195639/), among others, look at the "The Impact of ADHD During Adulthood" section). Just because _you_ managed to "sleep / eating / exercise" your way out of your situation doesn't mean that everyone else with ADHD is able to do the same thing.

I'm willing to be critical of psychiatry, and there definitely are people who are diagnosed with it who don't have it / don't benefit from / don't need medication, but the "overdiagnosis" moral panic ([https://www.ncbi.nlm.nih.gov/labs/articles/17709814/](https://www.ncbi.nlm.nih.gov/labs/articles/17709814/)) causes real harm to people who actually end up needing medical access.

<comment><USER4> Also you will find people with ADHD vastly overrepresented as alcoholics. To a shocking extent. It is insidious and easy for many to scoff at.

</comment></comment></comment><comment><USER5> Exercise over an hour a day because it helps my adhd. But i still have it and still have multiple things i have to do daily to manage it!

<comment><USER6> such as?

<comment><USER7> Not the parent, but for me - stimulation of senses helps a lot. Music, chewing stuff, moving a lot to focus. (some ADHD people go the other way and need absolutely zero distractions)

Headspace/meditation helps with anxiety. So does getting adrenaline pumping, and a proper diet, For example, for some people ADHD is related to problems with Tyramine processing, which blocks proper interaction with Dopamine, and switching into a tyramine-free diet helps.

Finally, of course: Ritalin, caffeine, sugar, nicotine. The first time in my life I tried nicotine and Ritalin (in lieu of sugar/caffeine and stressing myself), at the age of 33, it was crazy. The calmness and clarity. Finally could understand how people can sit at the desks for 8 hours a day!

As for exercise - it's quite easy as a kid, but imagine having to do 1h of serious exercise every single day for the rest of your life. Because, for me, that's the level that kind of calms me down. And no excuses, no "oh, I've got a deadline and a kid is sick, I'll skip it today". If you skip it, you cannot work. Period.

</comment></comment></comment><comment><USER8> This is from 2014.</comment>


Ask HN: What news source do you consider the most reputable, sober and unbiased? - blubb-fish My guess is NZZ (nzz.ch) - it's in German, though. <comment><AUTHOR> I don't really trust any of them. But as an American, I like to try and get at least some non-American viewpoints, so I will often check BBC World news and/or Al Jazeera. I'll also read / listen to CNN, MSNBC and even Fox News on occasion. I figure you have to consult multiple sources and sort of triangulate to get the real story, on most things.

<comment><USER2> What if all you are getting is the worst, most biased views and none of the truth?

<comment><AUTHOR> That would suck. But how can one ever _really_ know?

</comment></comment></comment><comment><USER3> Not sure if this is what you're going for or not, but Legible News ([https://legiblenews.com/](https://legiblenews.com/)) just has info every day on what's going on. It's basically just a bit of info and links to events that happen worldwide. But, I'm not sure how they determine which source for events to use.

I also agree with mindcrime's comment. I don't really completely trust any of them.

</comment><comment><USER4> Depends on the news you're looking for, but I've found Foreign Affairs to be pretty unbiased. It's more of an academic look into current problems in international relations.</comment>


Bitcoin Is Falling Out of Favor on the Dark Web - <AUTHOR> https://www.theatlantic.com/business/archive/2018/03/bitcoin-crash-dark-web/553190/?single_page=true <comment><USER2> Hard to continue reading an article starting with "Steep transaction fees" when fees are at historic lows...</comment>


To Sell a $1,000 Pill for $10 Without Losing Money - <AUTHOR> http://www.bloomberg.com/news/articles/2016-02-29/his-job-is-to-sell-a-1-000-pill-for-10-without-losing-money <comment><USER2> I was born with Hepatitis C. The whole situation is frustrating to me. For me in the US, insurance won't cover the drug unless I am in a category that is considered to be in great need of it (liver damage, etc.). So at this point I have to wait until my liver starts being damaged or the price comes down.

I understand the need for rationing given the pricing, but it's still difficult for me knowing that a cure exists but there's no way for me to obtain it. Perhaps I should consider medical tourism...

EDIT: After reading the prior authorization guidelines more, looks like I would be approved if I took up intravenous drug abuse or sex with high-risk males! Looks like I have other options :)

<comment><USER3> Looking at Pharmacy Checker, Offshore, which I believe ships from India, seems to have it for $74/pill (in odd quantities that don't seem to evenly divide what would be needed). Still lots of money and you have to worry about customs arbitrarily deciding to cause trouble (my impression is that is rare but can happen).

It looks like round trip airfare to India is available for under $1000, so that seems like the least expensive option. Wow, so travel to India costs less than what they sell one pill for in the US, and you can get the full 12 week supply for less than the second pill (the least expensive version of the full supply would get you just over half a pill in the US).

Good luck, I hope something works out for you.

<comment><USER4> Beware that Gilead is requiring doctors to check passports before treating people in India. Not sure how much it's enforced, but that was reported a few months ago.

</comment></comment></comment><comment><USER5> Short version - The fellow responsible for licensing the $1K Hepatitis C treatment to generic companies in poorer countries talks about the challenges in getting them out there, and making sure they don't cut into business back home. IOW, keeping control of a patent by making sure the folks who are likely to rip you off anyway make more money by working with you.

<comment><USER4> That's actually a really good summary.

Gilead has a lot of experience with differential pricing for developing countries. They have a large HIV portfolio and started doing this a long time ago.

</comment></comment><comment><USER6> "According to Doctors Without Borders, which is critical of drug-pricing policies, it costs Gilead $100 to manufacture the 90 pills in the 12-week course."

Sounds more like a $1.11 pill to me. And it seems pretty straightforward to sell something at (a minimum) 90% margin and make money.

<comment><USER4> That's purely the cost of goods. It completely ignore the cost of R&D.

It's like saying "oh, that CD I just bought only costs $0.30 to press, so $3 is a 90% margin". It's not. You can't ignore the millions that went into recording the music.

</comment></comment><comment><USER7> Very interesting. So, can China not just reverse engineer this pill, and distribute a generic version of it anyway?

<comment><USER8> I was wondering the same thing? Why couldn't another company just make a generic and sell it if there is such a high demand.

<comment><USER9> May be they have good know-how how do this in good level of cost and price. Or may be this is completely unnecessary for them (the china government). Normally if you have pharmaceutical generics comapnies they have big portfolio of many generics drugs ("they do not keep eggs in one basket and diversification also). Create company which have only one product and sell only to China market in my opinion is pointless.

<comment><USER4> Well, I assume Gilead is allowing Chinese companies to manufacturer authorized generics at a price in line with average wages. So people in China already have access.

The other concern emerging economies like China have is they are already developing their own brand name/patented drugs. If they don't respect the US/EU patents, they can't really complain when the US/EU doesn't respect theirs. The US market makes up almost 2/3 of the western drug market, so it would be a huge lose for China.

<comment><USER9> Yes, that could be also good explanation. I assume also that China, India etc. have completely different genetic population than europe populationes. This is important at clinical trials or bioequivalence study because some drugs substances could work differently for peoples form Asia and Europe. Pharma companies run trailes e.g in China and sell drugs only for regional area (because it work) this drug will be ineffective in Europe or could to do more damage.</comment></comment></comment></comment></comment>


Ridley Scott to produce sequel series to '2001: A Space Odyssey' - <AUTHOR> http://www.theverge.com/2014/11/3/7151169/ridley-scott-to-produce-sequel-series-to-2001-a-space-odyssey <comment><USER2> Honestly I'm excited. 3001 was an interesting book, albeit very short.

So far we're getting a Childhood's End TV miniseries, and a 3001 movie. How long until we Rendezvous with Rama movie? I really would like to see that.</comment>


"The Mountain West Is Experiencing a Second Gold Rush: They're Mining Bitcoin" - <AUTHOR> https://www.buzzfeed.com/charliewarzel/the-mountain-west-is-experiencing-a-second-gold-rush-this <comment><AUTHOR> "Thanks to its plentiful land and cheap power, rural Montana, Washington, and Wyoming are now home to a new crop of cryptocurrency prospectors. Their neighbors aren't too happy about it."</comment>


Ask HN: Why would a company like Apple hire a scalar wave researcher? - <AUTHOR> I was looking over job postings tonight and saw "Strong analytical skills in the area of scalar wave theory, partial differential equations, perturbation theory, nonlinear analysis techniques in wave propagation for acoustics and optics." with " Knowledgable/Experience on statistical mechanics, quantum theory as applied to gases." - I was curious as to how this engineering might be applied to future consumer technologies? <comment><USER2> They seek research engineer or physicist that can do work with semiconductor lasers and ultrasound in laboratory.

It may not be related directly to consumer products. Apple develops manufacturing technologies. On the consumer side there are many places where those skills may be useful. Self-driving cars, pulse or blood oxygen measurement, new cameras and sensors etc.

</comment><comment><USER3> Sounds like this person will be working on their rumored over-ear wireless headphone.

</comment><comment><USER4> Sorry, free energy doesn't count as valid science but Apple did hire jugglers, musicians and other non-engineers in the past.

</comment><comment><USER5> it would seem they are interested in quantum entanglement</comment>


Ask HN: Folks,know any good design courses/moocs/lectures for non designers? - <AUTHOR>

<comment><USER2> Weekly design lessons in your email: [https://hackdesign.org/](https://hackdesign.org/)

Somewhat dated, but still good: [http://www.designingfortheweb.co.uk/](http://www.designingfortheweb.co.uk/)

</comment><comment><USER3> What platform are you aiming at? I usually browse through dribbble and try out apps produced by well-funded startups to find new ideas.</comment>


The Open Cloud Has New Pricing For Bandwidth And Storage - <AUTHOR> http://www.rackspace.com/blog/lower-open-cloud-pricing/

<comment><AUTHOR> I don't have much experience with AWS other than S3, so I can't tell if the pricing point they are making is actually legit. Anyone with actual knowledge care to comment?

 _Meta_ : The lack of discussion here is why people use link-bait titles.</comment>


Is security outfit Norse Corp dead or just temporarily TITSUP? - <AUTHOR> http://www.theregister.co.uk/2016/02/01/is_norse_corp_dead_or_just_temporarily_titsup/ <comment><AUTHOR> Interestingly, with a quick look it seems like their mailservers are down too. I can't think of very many scenarios where a healthy company would shut down their emails.</comment>


Datasette Publish: a web app for publishing CSV files as an online database - <AUTHOR> https://simonwillison.net/2018/Jan/17/datasette-publish/ <comment><AUTHOR> This is essentially a web app that helps you deploy new instances of my Datasette application [https://github.com/simonw/datasette](https://github.com/simonw/datasette) without having to install anything on your own machine first.

I'm using new features of the Zeit API - [https://zeit.co/api](https://zeit.co/api) \- which makes it trivial to build apps that themselves deploy other apps. You dynamically construct a Dockerfile plus associated files, POST it to their deployment API and get back a URL which will host the resulting container: [https://zeit.co/api#endpoints/deployments](https://zeit.co/api#endpoints/deployments)

The possibilities with this kind of API are pretty amazing. Here's their announcement: [https://zeit.co/blog/api-2](https://zeit.co/blog/api-2)</comment>


Study shows 85% of people who say "mapquest" mean Google Maps - <AUTHOR> http://mockcrunch.com/2012/04/27/study-shows-85-of-people-who-say-mapquest-mean-google-maps/

<comment><USER2> when I need direction, i use mapquest, not Google Maps. So When I say Mapquest, I mean Mapquest!</comment>


Dennis Ritchie Day - <AUTHOR> http://radar.oreilly.com/2011/10/dennis-ritchie-day.html <comment><USER2> I agree with this sentiment (and that Jobs would have left much less of a dent were it not for Ritchie), but I can't help but think we've got this whole thing backwards. We should celebrate people such as Jobs, Ritchie and Uncle John in their life while /they/ could enjoy it, and not wait until they're gone. (So really, every day should have been Dennis Ritchie day, and John McCarthy day, and et cetera.)

But if there's a Dennis Ritchie day, or a John McCarthy day, I'll certainly take time to celebrate the life of a real hacker. They will be missed.

</comment><comment><USER3> Almost every day is Dennis Ritchie day for me, because almost every day I get to read and write C. Yes even in 2011. I look forward to hacker news being filled with C stories on the 30th.

</comment><comment><USER4> Excellent initiative. John McCarthy deserves his own day, as well. And if we are allowed to go back in time, we ought to dedicate a day to the early founding fathers of computing, such as Alan Turing.

<comment><USER5> Turing gets an awful lot of credit for being a founding father of computing and the majority of it is undoubtedly deserved, but the man whom is consistently overlooked and really is one of the founders of modern computing is a man called Tommy Flowers. He really did design and build the world's first electronic programmable computer; Colossus I. Sadly, he gets very little recognition here in the UK and practically none from the computing profession.

</comment></comment><comment><USER6> I think world is really unfair - Dennis Ritchie & John McCarthy got little acknowledgement even though they built the core technology (Programming Constructs, LISP, C, Unix, AI and GC etc) which is foundation for the current {new} technology.

</comment><comment><USER7> > I couldn't help be struck by Rob Pike's comments on the death of Dennis > Ritchie a few weeks after Steve Jobs

Wow, O'Reilly's sense of time is way off. Ritchie's death was announced one week after Jobs.</comment>


WhatsApp is broken, really broken - <AUTHOR> http://fileperms.org/whatsapp-is-broken-really-broken/ <comment><USER2> OT, but I'm intrigued by their business model.

I don't know the history, but currently, the Android app is free, and it says the use of the service is free for the first year, then will be $0.99 per year after that.

Meanwhile, the iOS app is $0.99 straight up.

Thoughts:

(a) "Free for a year, $1/year after that" seems like an awful long time to wait for a payday, but _if_ it works, and you get lots of free users, I bet you get more conversions in the long run than with a normal free/pro app business model.

(b) "Free in one store, paid in the other" is an interesting idea. If you can build up a large userbase of free Android users, and it's an inherently social app, your free Android users will tell their friends on iOS devices to get the app so they can communicate. They probably don't even know it's not free. It's like unintentional affiliate marketing.

(c) I realize (b) might not be an intentional choice by the developers, but a necessity due to the App Store perhaps not supporting pricing schemes like the one in (a).

<comment><USER3> Even more OT, but Angry Birds is $0.99 on iOS and free (with ads) on Android to this day: [https://www.google.com/search?&q=angry+birds+android+OR+...](https://www.google.com/search?&q=angry+birds+android+OR+itunes)

Just the nature of the different app ecosystems, really.

<comment><USER4> Could the fact that Apple pretty much force you to enter your credit card number in their system play a role ?

You used to be able to create an account without it, but not it seems impossible (or if it is, you have to do some devious thing 99% of the population could not figure out, even after solid googling).

<comment><USER5> > or if it is, you have to do some devious thing 99% of the population could > not figure out, even after solid googling

That "devious thing" is "attempt to download a free app without an account". Then it will present you with the credit card-free option.

</comment></comment></comment></comment><comment><USER6> This app has ridiculously penetration, however. I've met people who use this and no other app not out of the box before. In foreign countries it is easier to get someone to WhatsApp me than it is to get them to text my strange US number.

Sure they solved a pain that's very common, replacing expensive text messaging, but part of their success is how easy it is for users without annoying username/password hoops to step through. They should fix the security, although I don't do anything important over it anyway, but I can't say they went wrong by avoiding a classic username/password setup that might have been more secure from the start.

</comment><comment><USER7> We should all start using our regular XMPP accounts now! Most of us already have one. If you have a Gmail, Fastmail, Lavabit, GMX, Ovi.com, Yandex email address, you are ready to go. All that's left to do: Install Xabber or IM+ on your smartphone! Btw, both support OTR end2end encryption!

If you also want to instant message on your laptop: The latest Thunderbird comes with XMPP support! Or give Jitsi, which supports end2end encryption, or one of the many alternatives a try! Enjoy!

</comment><comment><USER8> I've been seriously considering creating a highly secure text messaging replacement. I'm aware of TextSecure but find it lacking (and only available on Android). I'd love to hear if you guys think it would be a worthwhile project.

<comment><USER9> You could make one but the audience would have almost no cross-over with WhatsApp.

Your app would have a nice geeky audience of tech nerds who would drool over how secure it is and how smart they are.

WhatsApp on the other hand "just works." It requires zero setup, zero technical understanding, and is available on almost every platform (at least the "biggies" anyway).

I would say its audience is teenagers, and the less tech savvy consumer in general. I cannot see them wanting to switch to something else unless you make come up with a USP which appeals to them (i.e. security is not a USP that they're interested in).

<comment><USER8> Those are basically the same thoughts that I had. Security is not enough of a concern for most of the market. I wouldn't built it as a commercial product, but basically as art for those of us who value privacy.

That said, I think the number of people concerned with message privacy is on the rise around the world. Over a few years, the market may grow significantly as privacy receives more attention.

</comment></comment></comment><comment><USER10> How do apps like WhatsApp get popular? They offer inferior service in every way to builtins, and require that both parties have installed something. SMS is in every way better unless you don't have a texting plan, in that case, GTalk and iMessage are in every way better (And GTalk is even cross platform with several fairly simple XMPP clients on IOS). Who uses this shit?

I encountered the same thing recently with Raidcall. It's a shitty voice service that's in every way inferior to Skype, but trying to position itself as a competitor to Teamspeak (Which itself has been eclipsed on features and price by Mumble). Yet, somehow people will argue with you about it and evangelize it, without any sort of benefit comparison.

<comment><USER11> WhatsApp was there first. Network effects cemented their position.

iMessage doesn't work for non-iOS phones. Annoyingly, GTalk doesn't have an official client on iOS. SMSes can get expensive.

<comment><USER12> No, there was an app Ping, which was around earlier than WhatsApp. It was ugly and didn't work well. WhatsApp is easy to set up, easy to use, and have relatively good functionality.

</comment></comment></comment><comment><USER13> I'm a "open source guy". Very picky to pay of Anything.

I use the mentioned app with my Lady every day because it works so well on her iPhone too. The easy of sending photoes is just pure awesome. Never failed (during one year). It works so well I don't hesitate a second to pay a dollar of it when it asks for it.

Ps. Drunk in a bar and a regular guy next me agrees who did not agree on punch of other stuff.

<comment><USER13> Pps. yes. Ofcourse the dude next to me did not know about the possible problems the auther mentions. Which ofcourse is an issue.

How to explain to a "regular dude" anyone can listen your phone call if they want to?

In my world everyone "normal I know" loves the mentioned app. How do I explain them everyone can read their messages if they want to? They answer me, everyone can steal my "normal" mail too if "they want to".

Ppps. I modified the typo i think i created after 8 pints.

</comment></comment><comment><USER14> Yes, it's insecure by the standards we would normally apply to software. But let's be honest - this is competing against SMS, not XMPP, Skype, et al. How hard do you think it is for someone to sniff an SMS?

<comment><USER15> Compared to this? Ridiculously hard. A5/1, while severely compromised, still requires heavy IOPS and computing power to break quickly with rainbow tables (see Kraken).

Even worse: this allows for trivial spoofing. You're far, far away from doing that with SMS.

<comment><USER14> Actually, SMS spoofing is arguably easier than WhatsApp spoofing.

</comment></comment></comment><comment><USER16> I'd have thought a large majority of what's app users use it for chatting. I can't imagine they're particularly fussed about people sniffing their plans for meeting up that night. There are varying requirements for security...

<comment><USER17> I suggest you go find some nearby open wifi in use, spy on some people, then tell them what you've found and see how they react to it. Report back when you're done... If you can....

<comment><USER16> If the table next door was having an obviously private discussion they'd probably be a bit put out if you started offering your opinion. People know their conversations often aren't secure, but then there are certain social expectations. Sometimes it's just expected that other people will politely ignore their conversation. If you told people that you had been spying on them I guarantee you that they would not blame their tech. They would place the blame squarely at your door for having listened in on something you shouldn't have.

</comment></comment></comment><comment><USER18> Sadly, normal free Jabber/XMPP does not seem to be a viable alternative. On Android, sure (though the clients are not too great at reconnecting/noticing- connection-loss/reporting-message-reception) but on iOS apparently you cannot run such things in the background. At least the situation was dire when I tried to convince some iOS friends to use XMPP instead of SMS last winter. <http://monal.im/> looked most promising but turned out to crash or only work when active, I don't fully remember. Maybe it got better.

<comment><USER19> You could run the real XMPP client on a server and use the native push messaging system to wake up the mobile client. This would also enable receiving "offline" messages while the mobile device is not on a network or turned off.

Of course, this would let the person operating the "real" XMPP client read your messages; but the person operating the XMPP server can do that already, so there isn't any real change -- either way you should be using OTR messaging at all times.

In the peer to peer spirit of XMPP, such a project should make it really easy to run this virtual client yourself locally or on a cheap cloud server. Maybe something like that exists already? Anybody wanna build it?

<comment><USER20> We've been trying to build something supporting that, but so far with far less than full steam. Too busy with client projects right now :)

<http://woboq.im/>

</comment></comment></comment><comment><USER19> No mention of this on their blog (in fact, no new posts since July). And no quick patch that pops up a box asking the user to assign a password. Since it's tied to a phone number/SIM card anyway, you could easily offer a password retrieval option via SMS.

I wonder what happens if a phone number (the login) is tied to a different IMEI (the password). This can happen when you transfer a phone number from one provider to another.

<comment><USER21> > I wonder what happens if a phone number (the login) is tied to a different > IMEI

I think they send verification code to the phone via SMS or ask your permission to make a call and speak the verification code.

<comment><USER22> Yep. You'll normally see this happen if you restore an iPhone backup onto another iPhone then try to launch WhatsApp. Login will fail and you'll be asked to type in the SMS received.

</comment></comment></comment><comment><USER23> Like Oscar Wilde once said, everything popular is wrong. Quality is well down in the list of things that matter to have a successful product.

</comment><comment><USER24> I was working on a better whatsapp api than the mess that is whatsapi, do not have enough time though. It's based in wazapp which has an actual implementation of the binary packed xmpp transfer mechanism they use. Might upload it if someone's interested, it seems broken right now though

<comment><USER25> Do it. It may be possible for someone to create a third-party client for WhatsApp instead of relying on the official version.

<comment><USER24> Look up wazapp, it's a third party client for Nokie N9

</comment></comment></comment><comment><USER26> So, what's the best alternative?

<comment><USER27> Viber [1] may be a good alternative. It s free on all ecosystems - iOS, Android, WP, Blackberry, Nokia and Bada.

[1] <http://www.viber.com/>

<comment><USER28> Like WhatsApp, Viber is free to use and has no advertising model. If they are not making money off me directly i have to wonder how safe my data actually is with this service.

<comment><USER27> WhatsApp is not free to use. iOS users are charged a flat 99c fee while Android users are charged 1$ a year from the second year onwards.

I do not know how secure Viber is but they have been steadilu acquiring good user base. If I was Viber, I would cash on this opportunity to write a blog or advertise their security models.

<comment><USER29> I' ve been using WhatsApp well over a year on Android. I got a free renewal in june. Never paid a cent.

<comment><USER27> Sure, you may have but are you the exception or the rule?

</comment></comment></comment></comment></comment></comment><comment><USER30> It's worse than that, in iOS devices the mac address is easy to predict. For instance my phone and my wife phone have the first _four_ bytes the same.

Example:

F0:AB:C7:11:xx:yy

So you can easily crack this by brute force without sniffing the device address at all.

<comment><USER31> This is by design[1]. The first 3 bytes are the same for the same manufacturer. The last 3 bytes can be assigned as they wish. Apple probably assign the 4th byte as a product identifier, so would be consistent across iPhones. I wonder what the 4th byte is for other iOS devices, or if it's the same?

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

<comment><USER32> That's very unlikely: an address space of just 65K numbers would be left, which is orders of magnitude less than the number of iPhones produced.

Considering that each phone has at least two MACs (wifi and bluetooth), even the 16 millions that would be given by using the full 3 bytes look scarce.

I think that Apple has several OUIs. In fact, my iPhone's MAC doesn't have a single byte in common with the parent's.

<comment><USER31> You're right, I didn't do the maths. This list[1] from 2010 shows that Apple has dozens of OUIs and I imagine the list is much, much longer now.

[1]<http://www.scribd.com/doc/42074577/Apple-OUI-List>

<comment><USER30> But maybe given products use a small subset of their available addresses...

Ok, there is a simple way, let's collectively compile a list of the HN users reading this thread having an iPhone. I'll start with:

       4s - F0:CB:A1:xx:yy:zz (me)
       4s - F0:CB:A1:xx:yy:zz (wife)
       4s - F0:CB:A1:xx:yy:zz (friend)

Please reply with your first three bytes.

<comment><USER30> Another friend of mine:

4s - 0C:77:1A:xx:yy:zz

</comment></comment></comment></comment></comment></comment><comment><USER33> > "On iOS devices the password is generated from the devices WLAN MAC address"

On what planet is using this data a valid form of security? Anyone can get hold of a MAC address.

</comment><comment><USER27> Just received an update on the iOS app stating "Full encryption for messages over mobile and WiFI".

</comment><comment><USER34> Anyone know if deleting message history is enough to kill the history on their servers?

<comment><USER35> On their website it says that they don't store messages on the server. Once yet are delivered, they get removed.

</comment></comment><comment><USER36> Does anybody know if the latest update changed anything on the security side?

</comment><comment><USER37> seriously though, why does it have to send the whole contact list EVERY time?

you close whatsapp remove the contact list permission, open it again, surprise, it won't work. -_-

<comment><USER9> I presume because the list of potential people who you could connect to might change.

I guess they could re-scan it on a schedule but that wouldn't solve your issue and might annoy their user base who are using it because it "just works."

Plus removing a permission isn't something any app supports that I am aware of. It isn't even something you're meant to be able to do on Android.

<comment><USER37> point being, it's a stupid idea. every half decent programmer would just update the diff.

<comment><USER9> Nope, I wouldn't even consider that. Firstly because K.I.S.S. and secondly because you've exchanged a relatively small data "cost" with a much larger storage and processing "cost."

You've had to have a database of everyone's contacts and then be comparing X with Y every few connections...

</comment></comment></comment></comment><comment><USER38> New version of whatsapp for iOS is there.

</comment><comment><USER39> Did the author email the WhatsApp team to give them any chance to fix this before they splashed it across the internet for anyone to abuse? The article makes no mention of it, so I assume not.

In my opinion, the obscurity peeled off by this expose did more to endanger WhatsApp users than the bad programming. So, I can only conclude this post's main goal is page views. OP could easily warn them, and at least wait until they didn't do anything before publishing.

<comment><USER40> My opinion - something so trivial as private data sent in plaintext isn't a bug or a security hole, it's bad by design. You shouldn't have to notify someone they've designed their app poorly. If he was taking advantage of a security hole, or something of that nature that wouldn't already be known to the developers, then I could see notifying them before publishing.

<comment><USER41> This is an excellent point. Fixing a design flaw this inherent is going to take more than a weekend of frantic dev time. It could conceivably take weeks to implement an overhaul to their framework, all the while the users are vulnerable.

<comment><USER39> They could theoretically take the app down, or issue a warning to users.

On the other hand, this article does little to alert users, while blithely informing techies, some of whom are likely to be hackers of some order.</comment></comment></comment></comment>


¿Qué son los Concerns y cómo probarlos? – Ruby on Rails - <AUTHOR> https://medium.com/@AMVMex/qu%C3%A9-son-los-concerns-y-c%C3%B3mo-probarlos-fb64b2125cc2 <comment><USER2> This looks on-topic, but this is a English speaking forum, so the submission will probably get ignored of flagged, unless it has some very interesting material that is not available in English.

I'm not up to day with the RoR development, but I guess there are similar articles in English.

Do you have an English version? With some luck it will be more popular here. (At least translate the title of the submission.)</comment>


On the Performance of User-Mode Threads and Coroutines - <AUTHOR> https://inside.java/2020/08/07/loomperformance/ <comment><USER2> I was massively surprised a few years ago how efficient Linux thread context switching could be.

I designed and implemented a dynamic scheduler for a streaming dataflow language a few years ago [1]. We wanted a runtime system which could have hundreds of OS-level threads execute thousands of dataflow operators that communicate in a dataflow manner. Threads should _not_ be statically assigned portions of the dataflow graph so that we could elastically add or remove OS- level threads based on observed performance.

We compared that scheduler to some other options, including just giving every operator in the graph its own dedicated thread. One test application was a simple 1,000 operator pipeline. We used two machines, one with 176 cores, the other 184 cores. To my surprise, with the pipeline application, the dedicated thread model beat my fancy scheduler in raw performance by up to a factor of 2. Keep in mind that that's 1,000 threads, all doing work, on machines with only 176 and 184 cores.

Of course, you would not want to do this in practice, even though the raw performance was so high: the machine was so massively oversubscribed during such experiments that it could barely keep up with a simple interactive shell.

But, my intuition had been wrong: I had thought that surely having 10x the number of threads as cores would mean the overall performance would crawl because of context switching time. It did not. See section 5.1 of my paper below for the experiment.

[1] Low-Synchronization, Mostly Lock-Free, Elastic Scheduling for Streaming Runtimes, PLDI 2017, [https://www.scott- a-s.com/files/pldi2017_lf_elastic_scheduli...](https://www.scott- a-s.com/files/pldi2017_lf_elastic_scheduling.pdf)

<comment><USER3> Similarly, Microsoft is advising that Fibers and User-Mode Scheduling are not actually very useful anymore. [https://devblogs.microsoft.com/oldnewthing/20191011-00/?p=10...](https://devblogs.microsoft.com/oldnewthing/20191011-00/?p=102989)

Combine this with Linus's recent rant about how avoiding the kernel during thread synchronization is counter-productive leads me to think that threads + a synchronized queue built with a mutex and a condition variable is simply the simplest and most effective way to go wide.

<comment><USER4> Windows fibers and the fibers Gor Nishanov rants about as being bad _in C++_ have very little to do with user-mode threads in managed runtimes like Java or Go despite sharing superficial similarities. In particular, a managed runtime knows exactly how code uses the stack and understands its representation, and Java does not have pointers into the stack. This means that stacks can be moved and resized very, very cheaply. The constraints and capabilities that matter the most simply don't transfer from one language or environment to another.

</comment></comment></comment><comment><USER5> This seems to be a response to Google's switchto work in the Linux kernel, which is motivated by task-switching costs, as per this 2013 LPC presentation: [http://pdxplumbers.osuosl.org/2013/ocw//system/presentations...](http://pdxplumbers.osuosl.org/2013/ocw//system/presentations/1653/original/LPC%20-%20User%20Threading.pdf)

Note the parenthetical in the article: "And that is how user-mode threads help: they increase L by orders of magnitude with potentially millions of user-mode threads instead of the meager thousands the OS can support (but don't expect a 1000x increase in capacity; we've neglected computation costs and are bound to hit bottlenecks in the auxiliary services.)"

This is something I'd like to see more of a focus on. For the generator use case, I can easily see how the kernel thread spawn operation is the bottleneck. But for the thread-per-connection server use case, I'm not sure how expensive this cost is relative to all the other work that the thread does. My suspicion is that Amdahl's Law is going to quickly rear its head here. Take stack size for example: assuming the kernel stack is 10kB, if your thread itself uses 10kB of stack, you've cut the theoretical memory advantage of M:N down from the cited 1000x to a mere 2x…

<comment><USER4> > This seems to be a response to Google's switchto work in the Linux kernel

Actually, it's a response to a discussion where somebody asked, "isn't it all about context-switch cost?" But user-scheduled kernel thread is something we had in mind when designing Loom, and we've made sure we can be compatible with them. We've introduced the concept of a pluggable custom scheduler, and that could be used for kernel threads just as it's used for virtual threads. The user can choose a thread implementation -- all kernel, all user-mode, or part kernel/part usermode -- without changing any code. It's all an implementation detail.

> My suspicion is that Amdahl's Law is going to quickly rear its head here.

That depends. Amdahl's law is about accelerating one job by parallelising it, while here we're more concerned with Little's law, which is about the rate of independent requests you can process.

> Take stack size for example: assuming the kernel stack is 10kB, if your > thread itself uses 10kB of stack, you've cut the theoretical memory > advantage of M:N down from the cited 1000x to a mere 2x…

Ah, except that's not so easy to do. It's very hard to have "tight" stacks that are managed by the kernel for the reasons I mentioned here: [https://news.ycombinator.com/item?id=24082951](https://news.ycombinator.com/item?id=24082951)

<comment><USER2> > Amdahl's law is about accelerating one job by parallelising it,

Amdahl's law is about the limitations of improving the speed of something, but not necessarily through parallelization. Its main point is that if you have some overall task, and you then speed up some subtask within it, the improvement to the overall time is limited to the contribution from the subtask.

In context of pcwalton's comment, I think they meant that thread creation time may be tiny compared to the amount of time a newly created thread will do work in a server context. If that is the case, improving the thread creation time will have limited benefit to serve time.

<comment><USER4> > Amdahl's law is about the limitations of improving the speed of something, > but not necessarily through parallelization.

Right, but the goal here is not to improve the speed of _something_ , but rather to handle as many different, mostly independent _somethings_ as possible, without necessarily improving their speed (latency), at all. Amdahl's law comes into effect in the delta between _mostly_ and _completely_.

> they meant that thread creation time may be tiny compared to the amount of > time a newly created thread will do work in a server context. If that is the > case, improving the thread creation time will have limited benefit to serve > time.

Right, this is the same argument as for the context-switch overhead. Still, I have to say that both virtual thread creation and context-switching are much better than for OS thread, but the point of the post was to show that in many common use cases that is not where most of the benefit comes from; rather it comes from the number of threads you can have.

For example, if thread creation time was high but you could create millions of them, you could create all of them up front and pool them and still get most/all of the benefits. But if thread creation time was low but you could only have a few thousand, then you'd still lose big because of Little's law.

<comment><USER2> Agreed, strongly. I was just concerned the original comment may not have been fully understood.

</comment></comment></comment></comment></comment><comment><USER6> The article explains that the primary benefit of user-mode green-thread fibers is not switching speed, but that they are much cheaper than OS threads, so you can have many more of them. The costs are paid in memory usage and also the operating system also has to do considerable bookkeeping for threads.

However, Netty has offered strong support for callback style IO under the JVM for a long time. This effectively allows the same efficiencies. Of course it is also possible to do without Netty. Therefore the real advantage of Loom user-mode threads and co-routines is syntactical programming convenience. That's the real innovation in Loom!

<comment><USER7> I thought the memory cost of threads was more of a JVM thing (default 1mb stack) than an OS thing (pages that aren't mapped/resident don't cost much).

What's the cost to the kernel besides a few structs?

<comment><USER4> Once a page is committed, it cannot be uncommitted until the thread dies, because the OS can't be sure how much of the stack is actually used. It cannot even assume that only addresses above sp are used. Also, the granularity is that of a page, which could be significantly larger than a whole stack of some small, "shallow" thread, and we want lots of small threads.

<comment><USER8> How many parked "fibers" do you think a 32-bit JVM might be able to handle once loom is ready for prime time? A thousand? A million? Somewhere in between?

<comment><USER9> I doubt 32bit is an issue for this and I'd assume well over a million, if Kotlin's coroutines are anything to go by: [https://kotlinlang.org/docs/tutorials/coroutines/coroutines-...](https://kotlinlang.org/docs/tutorials/coroutines/coroutines- basic-jvm.html#lets-run-a-lot-of-them)

<comment><USER8> 32-bit means you have at most 4 gigs of address space to play with; pron implied that lower memory usage is the key savings of fibers vs threads, so I assume a 32-bit JVM will hit a memory limit a lot sooner.

</comment></comment></comment></comment></comment></comment><comment><USER10> The word performance is a bit misleading here. A key reason to use co-routines is not necessarily maxing out CPUs but IO. Non-blocking IO and co-routines allow handling many connections on very modest hardware. Blocking IO and languages that don't handle concurrency very well (scripting languages like ruby or python) deal with this by forking multiple processes, each of which typically can only do one thing at the time. Java historically worked around this by using threads.

Using processes doesn't scale nearly as well and you typically run out of memory before you run out of CPU this way. Using threads like Java does scales a bit better but there are only so many threads you can juggle. Co-routines or green threads combined with non blocking IO is much better and is also becoming common on the JVM where pretty much most modern frameworks support this. And of course if you use Kotlin, co-routines provide a really solid implementation and programming model for this.

This is also the reason for the popularity of go and node.js, which aren't known for their particular ability to get the last bit of performance out of CPUs but do scale rather nicely when it comes to handling non blocking IO asynchronously.

<comment><USER11> > Co-routines or green threads combined with non blocking IO is much better > and is also becoming common on the JVM where pretty much most modern > frameworks support this.

Appreciate the insightful comment.

Basically, the ideal utilization of compute resource (cpu and ram) is engineering for _both_ async I/O and and maximizing cpu threads, correct?

I agree, mostly.

I can't say I am very confident in understanding / implementing concurrent threading in any language. I am working on trying to get it, but sometimes I don't know if it is worth the mental over head or the added code complexity.

Single threaded async alone took me a while to grasp, and I am sure I still have gaps in my knowledge. But mentally modeling a single threaded execution is trivial.

I guess I try maximize for my own understanding and efficiency versus maximizing for performance.

</comment></comment><comment><USER12> This is the first time I've heard of the .java TLD, but sadly only Oracle and its affiliates are allowed to register domains[0].

[0]: [https://www.oracle.com/a/ocom/docs/registration-policy- java-...](https://www.oracle.com/a/ocom/docs/registration-policy- java-2418402.pdf)

</comment><comment><USER13> See also this thread from 2 days ago on _Sub-10 ms Latency in Java: Concurrent GC with Green Threads_. There's some discussion of Project Loom there.

[https://news.ycombinator.com/item?id=24059335](https://news.ycombinator.com/item?id=24059335)

</comment><comment><USER14> I wonder if kernel aware green threads will obscolete conventional green threads such as in Loom.

[https://www.phoronix.com/scan.php?page=news_item&px=Google-U...](https://www.phoronix.com/scan.php?page=news_item&px=Google- User-Thread-Futex-Swap)

<comment><USER4> User-scheduled kernel threads mostly address the context-switch question (and, more generally, the choice of an appropriate scheduling algorithm), but don't help as much with the footprint, and so with the level of concurrency, _L_ , and _that 's_ where the biggest win is. To do that requires a deeper knowledge of how the language makes use of the stack than the OS can do. Still, they have their uses, too, and the expectation is that when they arrive, Java will support them, too, as a third implementation of threads.

<comment><USER14> _To do that requires a deeper knowledge of how the language makes use of the stack than the OS can do._ I often hear that argument but isn't the reverse argument also true? While the JVM has access to information and language semantics useful for threading, that the kernel doesn't have access to. Doesn't the kernel have access to useful information for threading that the JVM green threads doesn't have access to? The one information that come to my mind is being aware of all threads from all programs and not only the ones from the JVM. So could next generation green threads have some access to some of this information? Could this enable greater performance? If so, how? Could Google futex wait help there?

 _they have their uses, too, and the expectation is that when they arrive, Java will support them, too, as a third implementation of threads._ Great to hear that but I hope that their use cases will be well defined and not overlap too much with loom. _wild idea_ : could the JVM loom scheduler at runtime convert a green thread into google thread & vice versa? That could help performance, especially on pathological cases?

Finally, I _believe_ that say 1000 green threads actually reduce to a thread pool of kernel threads encapsulated by the JVM, if this belief is correct, then the real kernel threads underlying the green threads could benefit from being futex wait kernel threads?

<comment><USER4> > Could this enable greater performance? If so, how?

I don't know. Any ideas?

> Great to hear that but I hope that their use cases will be well defined and > not overlap too much with loom.

Supporting them would be a part of Loom.

> could the JVM loom scheduler at runtime convert a green thread into google > thread & vice versa? That could help performance, especially on pathological > cases?

Virtual threads' schedulers aren't in the VM. They're written in Java and are pluggable. But the answer to your question is yes, it's possible -- and not too hard, even -- but I don't know how much it would help.

<comment><USER14> _Any ideas?_ I'm not an expert, the only idea that I have in mind is simple: Say that you want to maximize cpu cores usage. So in that case you want to create ((N * 2) - Y) kernel threads underlying the user mode threads. Where N is the number of cpu cores and Y is the number of current kernel threads (but maybe that user space can access that information through a syscall?) This information allow optimal number of kernel threads backing the green threads. Optimal when you only want to maximize computation (and not concurrency like you explain in your blog)

I would like to ask you two other things: Firstly I have seen in the Loom document that it will use restartable sequences. I find such creative use of modern Linux technology an awesome thing to do. But you might need to delay support for them: [https://www.phoronix.com/scan.php?page=news_item&px=Glibc- Re...](https://www.phoronix.com/scan.php?page=news_item&px=Glibc-Restart- Restartable-RSEQ)

Finally, I would really like you to attempt a comparison of Loom with current Kotlin coroutines. I'm sure that you have learnt a bit from them as they honestly are the state of the art most ergonomic coroutine I have ever seen, especially regarding the following points: Exceptions just works Beautiful structured concurrency You can trivially specify and adjust on the fly the "scheduler" through both its context and its dispatcher Great cancelation support Colorless (no pollution with a completable future) Beautiful integration with reactive streams reinvented, through flow.

I don't expect Java Loom to be able to syntactically be as beautiful and simple as Kotlin coroutines but it would really be an accident to not be as expressive. So I hope that you will borrow all of their concepts as it's well thought, maximally expressive yet simple.

So a comparison on the surface level features would be nice. But what interest me the most would be a comparison of how technically kotlin coroutines currently works and in what way loom will outperform them? (as you can already have ~1 million of coroutines) I expect better performance as you have access e.g to io_uring.

I hope that Kotlin coroutines will be able to be transparently reimplemented using Loom threads, and therefore it would be very nice that the Loom's architects communicate with Kotlin architects on interoperability and reuse / synergies. Both communities bring great progress on the JVM and it's beautiful to contemplate.

</comment></comment></comment></comment></comment><comment><USER15> I think the Go scheduler makes a good case for multiplexing a large number of user-mode threads (or goroutines) over a limited number of OS threads: whenever a goroutine needs to make a blocking syscall (e.g. writing to a socket), the work is offloaded to a "network poller" thread, and meanwhile the Go scheduler can continue to service other runnable goroutines.

It seems to me that this allows Go programs to maximize the use of their OS- thread time slices without being preempted on each syscall. Does anybody care to comment on how this impacts throughput and latency?

</comment><comment><USER16> In my mind user-mode threads are much more about engineering productivity than raw performance. The comparison is wasteful blocking network calls using threads written in a simple synchronous way vs efficient user mode threads making network calls in a non blocking way also written synchronously.

Today to get non blocking efficiencies you need to write async code bc without loom there is no otb user mode threads, even if user mode threads aren't as efficient in raw numbers it's still waaay ahead of the predominant way threads are used today in Java (mostly wrt network calls).

</comment><comment><USER17> Are there any online resources that provide an overview of various advanced concurrency patterns in various programming languages.

I would like to understand various trade-offs between multiple approaches.

</comment><comment><AUTHOR> If interested in aggregated Project Loom news: [https://inside.java/tag/loom](https://inside.java/tag/loom)

</comment><comment><USER18> This site seems to have a lot interesting articles. I have been trying to read about things like this on OpenJDK. But this site seems to be very easy to navigate on (unlike openjdk). It is also highly likely that I am an idiot.</comment>


This is why Google is king - <AUTHOR> http://www.feedmyapp.com/p/ranked/1 <comment><USER2> I'm sorry, but _who_ gets to rate the apps?

<comment><USER3> I think it's fairly accurate. Google's APIs is the standard library of the web, imo.

<comment><USER2> I can't tell how the data is collected. Hell, I would have expected as a visitor to the site:

a) explanation where the rating comes from

b) be able to rate stuff myself.

But there you have it. But maybe I'm just too used to the way the AppStore lets users rate + review apps.

</comment></comment></comment><comment><USER4> All i see is a bunch of ads, no way to vote, no figures how many "votes" there have been... soo.. scam?

edit: plus the "hey, buy ads on our site!" all over the place

</comment><comment><USER5> Hello everyone, I am Simone Susini ofthe Feedmyapp Team. The ranking is based on Alexa and what you see in the link is a bug due to the fact that all third- level domains are the same for Alexa ranking. The ranking is visible only in list view or in the app page but not in the Thunmb list view. Sorry for this problem, we are looking for a different ranking to work with third level to resolve it.

</comment><comment><AUTHOR> In case you don't get it right away, they are sorted by top rated/most ranked through that link. See something in common?

</comment><comment><USER6> It looks like a Google Sponsored Ad.

</comment><comment><USER7> my jquery plug-in is listed there, it is not google's though I am glad to find it listed there

(<http://code.google.com/p/js-hotkeys/>)

</comment><comment><USER8> why do the votes on this obscure website signify anything?</comment>


Ask HN: Explain the Internet Back-Bone - <AUTHOR>

My son is 12 and a Boy Scout. He is earning his computer merit badge.
One of his requirements is to explain how the internet is structured. Obviously topics like Web-servers, switches, routers, fiber, cat 5, e-mail servers, etc, etc
But I wanted to explain the back-bone to him and I dont quite know how. How does one get to be on the back-bone? How does the Back-bone exist? Isn't there a group of DNS Servers that are like the core DNS on the back-bone?
Can anyone provide some advice or thoughts? <comment><USER2> There isn't one, because the internet has grown too big.

<http://en.wikipedia.org/wiki/Default-free_zone> and follow the CAIDA link - their routing maps and other visualizations will put any objections to rest.

Incidentally, it's rather disturbing how far behind the US appears to be in terms of IPv6 deployment.

See also: <http://www.caida.org/research/visualization/>

Cuttlefish is probably most appropriate for inclusion in your son's project.

However, Walrus is IMHO the coolest thing ever that nobody talks about, despite having been open source for several years. I'm unaware of continued development, but this may be helpful if you have a dataset you'd like to view: [http://www.soa-world.de/echelon/2008/10/convertig-csv- files-...](http://www.soa-world.de/echelon/2008/10/convertig-csv-files-to- libsea-graph-files-for-caidas-walrus.html)</comment>