Study Explains Why We Arrest Moms for Putting Kids in Nearly Non-Existent Danger - <AUTHOR> http://reason.com/blog/2016/09/22/breakthrough-study-explains-why-we-arres <comment><USER3> As a parent of two kids, the leaving children at home unattended while the parent runs a short errand being considered a crime has always caused me anguish.

The leading cause of death in children in the United States is by car accident[0]. So if my youngest son is asleep in his crib and I need to leave to grab groceries from the store a mile away, I have to wake him up, strap him into his placebo seat[1], and put his life into statistically far, _far_ greater danger than the risk of him somehow suffocating in his empty crib or dying in a house fire. Not to mention the added stress on both him and me that arises from waking a toddler prematurely--stresses that result in shaken baby syndrome and the third leading cause of death in his age group.

[0] [https://www.cdc.gov/injury/wisqars/pdf/leading_causes_of_inj...](https://www.cdc.gov/injury/wisqars/pdf/leading_causes_of_injury_deaths_highlighting_unintentional_injury_2014-a.pdf)

[1] [https://www.ted.com/talks/steven_levitt_on_child_carseats](https://www.ted.com/talks/steven_levitt_on_child_carseats)

<comment><USER4> Upfront, I want to say that I agree with just-about everything that you have written here. I would have upvoted you and move on if it weren't for the lame "placebo seat" comment. It's beyond me as to how anyone could watch that talk and agree with Mr Levitt's conclusions.

He flat out admits that his only sources of his "research" are 1) the DoT NHTSA's FARS [0] and 2) four crash tests that were run by an anonymous test center.

I can't think of a better example of a red herring argument. He's basically saying, "Don't bother second guessing my data because I have these videos from a person who will NOT collaborate the results."

The FARS data is heavily biased as well. First, it only reports _accidents with fatalities_. It's a completely voluntary survey, it's up to state and local governments to enforce their police jurisdictions to comply. At the time of the video it spanned 30 years of data, 1975-2005. There's incredible amounts car safety improvements in that time frame. I'll defer to an expert here, but air bags and crumble zones will top that lists; I'm sure there have been improvements to seat belts and car seats in that time. Point being, most of that data is irrelevant.

And, then his ego shines through when he glorifies economists superiority over "scientists" because economists "look at real world data"; if his opening wasn't awkward wretch inducing already, then that surely should have done it.

If you want to be an advocate for Mr. Levitt's ideas proceeding for actual scientific inquiry, have at it. But, don't spread a cockamamie pejorative, like "placebo seat", because you watched a terrible TED talk.

I can't help, but feel my response was overkill for having taken offense from two words. I attempted to find some follow up studies based on Levitt's TED talk, but as it should be to nobody's surprise, neither side seems to have taken it seriously (to progress nor retort). The only source that I found which I actually liked is called "What If These TED Talks Were Horribly Wrong?" [1]. In which, Levitt gets top billing, and there is link to a study called "Effectiveness of Child Safety Seats vs Seat Belts in Reducing Risk for Death in Children in Passenger Vehicle Crashes" [2]; it's freely available, but I have yet to read it.

[0] U.S. Department of Transportation, National Highway Traffic Safety Administration, Fatality Analysis Report System, [http://www.nhtsa.gov/FARS](http://www.nhtsa.gov/FARS)

[1] [https://theawl.com/what-if-these-ted-talks-were-horribly- uns...](https://theawl.com/what-if-these-ted-talks-were-horribly-unspeakably- wrong-c4b94e2c4824)

[2] [http://archpedi.jamanetwork.com/article.aspx?articleid=20506...](http://archpedi.jamanetwork.com/article.aspx?articleid=205063)

<comment><USER5> It seems like a good majority of TED talks are based far more on flashy presentation and emotion than hard fact.

<comment><USER6> So what about your own seemingly mostly emotion-based blanket one-sentence statement that omits even the attempt of citing prove, or even to actually examine the issue you present?

Relevant ancient educational tiny story: [https://riddlesbrainteasers.com/three-philosophers- tree/](https://riddlesbrainteasers.com/three-philosophers-tree/)

I got an epiphany moment about that story when I read a story about a medical doctor visiting a "quack" conference. There was one "esoteric" who complained about the others being "esoteric" (he practiced something else than the others, but still something weird), and the doctor looking down on them all. But the crowning part of that story was that the doctor herself held a believe by now proven to be wrong by studies. So they were all laughing about each other, in addition to the original three-philosopher problem this anecdote included a hierarchy (I am better than you), going over several levels, and it turned out the person who thought was at the top looking down on everybody else actually wasn't and should have had a good look in the mirror herself.

The hint should have been seeing that one guy lamenting that all the others were esoteric, but introspection based up on what we see in others isn't many people's string suit. No, (only) _they_ are "stupid".

The philosophers in the little ancient Greek story/riddle managed to get to the truth by including themselves into their logical reasoning and not just think about the others. When you come to a conclusion about other people, always consider if/how it applies to yourself.

The more modern saying is that about throwing stones in a glass house... but it lacks the educational value of the three philosopher problem because it's only the "TL;DT" (too long, didn't think).

<comment><USER7> Whether it is reasonable to believe something does not depend on whether it is true (because you can't know that), but on whether it is the currently best- known explanation of the available evidence.

Quacks aren't stupid because what they believe isn't true, but because they believe it without sufficient evidence, or, often enough, despite evidence to the contrary.

<comment><USER6> I don't understand your reply - could you please tell me what connection there is with what I wrote? Seems like random rambling to me.

<comment><USER8> I presume the argument was that a doctor who is misinformed about the latest studies in wrong is an entirely different way to a quack (e.g. a vaccine denier) who may be 'not even wrong'.

<comment><USER6> You presume too much and don't understand the story. Maybe you grow into it some day, some things cannot be taught.

Not to mention that your reply is the pinnacle of hypocrisy and stupidity. "Even when I'm wrong I'm _better_ wrong than you!" How incredibly stupid.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER9> I'd love to see people do some PSAs on this. A campaign for people to back the fuck off.

Mom leaves child at home to shop; evil music plays; kid looks like he might get into trouble; nothing happens and everyone smiles at the end with some statistics on how it's pretty safe.

<comment><USER10>
        INT. HOME - <USER2>

        A MOTHER is getting ready to leave the house. Her
        TODDLER is sitting in his playpen.

                MOTHER
              (Warmly)
            I'll just be gone for a few minutes, buddy!

                TODDLER
              (Pleased, without understanding)
            Gah!

        The door slams and a nosy NEIGHBOR appears immediately
        outside the window. Seeing the unattended TODDLER, the
        NEIGHBOR gasps, and calls 911.

                NEIGHBOR
            Hello? Yes, a woman has just left her baby
            unattended!

        Two police officers appear. OFFICER #1 arrests the
        NEIGHBOR. The MOTHER, returned, holds the TODDLER as
        both watch the NEIGHBOR's arrest. Before getting into
        the cruiser, the NEIGHBOR turns to OFFICER #2.

                NEIGHBOR
              (Weeping)
            But...why?

                OFFICER #2
              (With visible lack of sympathy)
            You've caused more trouble today than you
            could statistically have prevented.

<comment><USER11> Have an upvote well deserved. Thank you for making me laugh, even on a serious matter as this.

<comment><USER10> Thanks. I just wanted to highlight the absurdity, as it's an issue I care about; if I'm ever a parent, I don't want self-proclaimed do-gooders meddling in my family's affairs.

<comment><USER12> Like Gladys Kravitz on Bewitched. [1] [2]

[1] [http://bewitched.wikia.com/wiki/Gladys_Kravitz](http://bewitched.wikia.com/wiki/Gladys_Kravitz)

[2] [https://www.youtube.com/watch?v=-mdFctlvB3w](https://www.youtube.com/watch?v=-mdFctlvB3w)

</comment></comment></comment></comment></comment><comment><USER13> Definitely agree with the conclusion that nowadays, "In other words, the only socially acceptable mom has become a mom who never takes her eyes off her kids".

When I was growing up in the 90's and took the bus to school, parents just dropped off the kids on the corner and parents go about the day. Now when I drive by school bus stops, I see a line of cars parked on the side of the road. Both parents and kids sitting in the car till the bus comes.

<comment><USER14> A major unanswered question I have is why this happened. Where did this collective insanity come from?

<comment><USER15> Even before the arrival of social media, the mass media was feeding people stories about the world which made it look far more dangerous than it actually was. So media isn't the reason.

The reason is that the majority political philosophy in the US has shifted from libertarianism/classical liberalism to progressivism. The libertarian point of view is that people generally should be free to go about their own business in the manner they see fit. The progressive point of view is that we have a collective responsibility to police the wrongdoing of other people and fix it, using state power if necessary.

In the video where the guy goes off at the mother for leaving her kid in the car, you can see the progressive power dynamic in play immediately. The guy thinks she's doing something wrong so he gets involved. (Who is he? Doesn't matter. It's everyone's job to right wrongs.) It takes maybe 15 seconds before someone mentions the police, because the only way such intrusive activism works is when a higher power (can be state, law, society, science, God, whatever) is used to identify and enforce a definition of what's right. Even though the activist doesn't explicitly threaten to call the cops, during the confrontation they are mentioned constantly because the threat of state power is the only reason the mother even has to give this guy the time of day.

If you want to go a level deeper and ask why this political shift has occurred, it's likely that one contributing factor is urbanization which been underway in the US for some time--historically densely populated cities tend to be more authoritarian than rural areas because a crazy person can do more damage in a dense city (you don't see mass shootings happening in cornfields).

<comment><USER16> If progressivism is at fault, why aren't we seeing this problem in countries that are far more progressive?

<comment><USER15> That would depend on which country you're talking about. I think some countries like Sweden get away with being more progressive because they're more homogeneous. People in these countries have fewer differences of opinion and a higher level of social trust in general.

</comment></comment></comment></comment></comment><comment><USER17> "We" should be replaced with Americans. This is just one more of those nutty things which are particular to America but which doesn't really generally happen in the rest of the west.

This is a much broader issue. America is simply developing a very dysfunctional way of dealing with children. America is the only developed country I know of (maybe only country period) where police is routinely used to deal with school discipline issues. Even parents in the US call police to discipline their kids for silly stuff like drinking alcohol. I am actually surprised by how normal this is in the US even among intelligent and seemingly normal families.

With the extensive killing of blacks it is clear that the US has a general police dysfunction. The police is seen as a solution to almost every issue in society.

America needs a serious re-evaluation of what role police and punishment should play in society. Police and the justice system can't become a substitute for parents and teachers.

<comment><USER18> America wasn't like this when I left in the late 80's. I'm not saying that America had no problems -- clearly it did, but there wasn't so much fear, and things felt more free (at least if you were white) and different parts of the country still were different -- the chain stores hadn't yet homoginized the country -- and turn coffee into a fetish.

It was a shock to see it happen in slow motion from the opposite side of the world over the next three decades, the country just seemed like a frog being slowly boiled without it being aware.

From time to time people ask me why I don't move back and I just smile and say that this is my home now. Few people would understand the sadness I feel for those left behind.

<comment><USER19> In the late eighties we imprisoned a bunch of daycare workers for satanic ritual sexual abuse, based on tedtimony coerced from children over long periods. No physical evidence was ever found.

</comment></comment></comment><comment><USER20> This is really mind-boggling to me as someone who grew up in the 1990s frustrated by having an "overprotective asian mom." When we were 5-6 she'd kick us out of the house in the morning to go play with the neighborhood kids and tell us to come back for dinner. We walked to school alone, waited for the bus stop alone, etc.[1]

Yuppie millennial parents are hands down the worst. It starts with the baby wearing and escalates from there. We've got a rooftop club-house/grill in our apartment building. I was grilling some steaks when my daughter (almost four) said she needed to use the bathroom. I took her inside, left her in the restroom, and went back to check on my steaks. When I got back, some mom was standing there with her in the hallway giving me the eye. Lady, kids don't get stolen from locked-down apartment buildings--relax.

[1] The school even posted 3-6th graders as "patrols" to help the smaller kids cross some of the intersections, with nary an adult in sight.

<comment><USER21> With you everywhere but the babywearing bit. Especially in an urban environment, strollers are a downright hassle. Unless and until the kid's too heavy to carry comfortably, it way easier to just strap 'em on your back and go about your business virtually unencumbered than it is to spend the whole day wrestling with a glorified shopping cart.

<comment><USER20> Sure, baby carriers have been used throughout the world long before strollers were invented. But the recent resurgence in the west is driven by the popularity of attachment parenting: [https://en.m.wikipedia.org/wiki/Babywearing](https://en.m.wikipedia.org/wiki/Babywearing).

<comment><USER21> Genetic fallacy, yo.

Even if you're not fond of attachment parenting, that doesn't imply that everything attachment parents like is a bad idea, or even that things that attachment parents like are primarily only popular with that subculture.

</comment></comment></comment></comment><comment><USER22> We will look back at the late 20th century/early 21st century and facepalm about all the horrific stuff we've done in the name of 'psychology', 'education' and 'safety'.

I feel like there has never been a more vile and aggressive attack on common sense than these days, in the sense of a regression, rather than a progression of common sense which one would expect with a growing body of science.

<comment><USER14> The really insane thing is this: we have never in all of human history been safer.

Crime is at a 50 year low, and nearly everyone has health care. Not only that but more than two thirds of the population carries a location aware communication device that can be used to summon help almost anywhere in minutes.

I sometimes wonder if this is in fact the problem. Maybe we are so wired for scarcity and danger that we become neurotic and paranoid in its absence. It's analogous to the 'hygiene hypothesis' for allergies.

<comment><USER23> I think there's a simpler explanation: observation bias.

30 years ago there was more crime, but if it didn't happen in your town or to someone you knew, you were pretty unlikely to hear about it. Now, there's less crime but we're orders of magnitude more likely to hear about it.

IMO, this is a side-effect of 24-hour news networks and social media needing something to fill the dead air.

<comment><USER24> Essentially, if it's a problem you read about in the newspaper, it is highly unlikely to affect you. Consider that the newspaper doesn't report car accidents, cancer diagnoses, etc.

<comment><USER25> What are you talking about? Last month Jax from American Idol was diagnosed with cancer and the news outlets were prompt in reporting it. [https://www.yahoo.com/music/american-idol-star-jax-speaks- ou...](https://www.yahoo.com/music/american-idol-star-jax-speaks-out-about- cancer-battle-at-age-20-214349084.html)

<comment><USER24> He's a celebrity.

</comment></comment></comment></comment></comment></comment><comment><USER26> Yeah yeah yeah. Everyone is talking big here about how "obviously" these inflated concerns about child safety are absurd and ridiculous.

But how many of you would step up to slap down those morons who berate parents for leaving their kids in the car for 30 seconds?

THAT is what is needed. It is no good to simply THINK that these people are going overboard. We have to actively STOP the stupid busy-bodies from assaulting those poor parents.

Step up. Step in. And slap down.

<comment><USER27> > But how many of you would step up to slap down those morons who berate > parents for leaving their kids in the car for 30 seconds?

The morons in question are generally litigation-happy brown-nosing assholes, so that's a good way to get charged with assault and battery.

<comment><USER28> The parent comment may have been using colorful idiomatic phrasing to advocate for non-violent verbal engagement.

</comment></comment></comment><comment><USER29> Many social factors often external to the economy would negatively change our understanding of our "standard of living" if included. In the USA, if you only look at the nominal median wage and then subtract the inflation tracked by the Consumer Price Index then it seems like the male median wage peaked in 1973 and family income peaked in 1999. But the CPU does not track rent, and the peak year for the ratio of wage to rent was 1958, which was also the peak year of the Baby Boom (and obviously those 2 facts are linked).

If you were to also track the social changes that have increased the scrutiny on mothers (and parents as a unit), the question would arise if real, meaningful family income actually peaked in 1999. Perhaps it was in decline a long time before that?

I was in kindergarten in 1972. I grew up in an affluent, white neighborhood in the suburbs. At that time, it was thought normal that the children should walk to school on their own. The school was exactly 1 mile away. My parents kissed me goodbye at the door of our house, then I joined up with my friends, and we walked to school. Yes, we were 5 years old.

Any parent who does this nowadays will be arrested, but at the time it seemed safe because everyone did it. I never walked to school alone, I always walked with my classmates. I'm told that Japan is still somewhat like this, but obviously the USA has changed.

<comment><USER13> Can confirm..in my trips to Japan, Korea, Hong Kong, China...Kids take mass transportation by themselves to and from school. Hoards of kids play at the park with few adult supervision.

Up to elementary school (1994) I would walk to the park with some friends after school and play or go to the library (next to the park) for 2.5 hours till my mom picked me up. It's where a lot of kids went.

Generally if there is only one or two kid left at the park, a parent would stay after to ensure everyone is picked up.

My middle school was in a different part of the city so not sure how much longer I would have continued that.

</comment></comment><comment><USER30> I hate all the internet shaming that goes into this.

Everyone on the internet feels that they get to judge a parent's parenting ability.

Some kids are more responsible than others.

I was handling myself at age 6 in Europe. I was navigating public busses from age 6 on.

I have had police officers tell me I am putting my own kids in danger by leaving them alone in a car.... when they were 8 and 7 years old (and in front of my house).

The police officer couldn't even articulate what the exact danger was.

<comment><USER31> The danger of leaving a kid in the car is heat if it's warm outside. That may or may not have been a reasonable concern based on the circumstances.

<comment><USER32> I remember being left alone in the car at 7 or 8. If it was too hot I would have opened the window, or in extreme cases, stepped outside for some time.

</comment></comment></comment><comment><USER33> It doesn't help that every couple of months, my phone suddenly blurts out "Amber alert!...". [0]

It's well intentioned, and has been effective, but talk about keeping a society on edge about child safety. It's really unnerving.

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

<comment><USER34> you can turn that off, you know...

<comment><USER35> But why would you? I know of incidents just this year that a child was saved because of amber alerts. It's put out for the same reason that people on here are arguing for "if your surrounding community were more aware or had a personal interest in each other, these situations would not happen"

<comment><USER36> Because it doesn't respect the silent setting on my cell phone. Its unlikely the missing child is in the vicinity of the meeting I just interrupted.

<comment><USER37> I couldn't remember why I turned it off and now I do.

</comment></comment></comment></comment></comment><comment><USER38> A couple reasons, I think.

As Americans, we are inundated with news that tells us how bad our neighbors are and how they only want to harm our children. This may have started with some high profile kidnappings, etc. in the 80's and 90's. Now, you can't let your child go anywhere alone. Ever.

We're a blame society. If we do something wrong, it's someone else's fault. This thought process has expanded to if we see someone else doing something we think is wrong we blow it out of proportion. We so desperately want to find faults in others. As if that'll make our own faults less significant.

Note: 'We' is a generalization.

</comment><comment><USER39> Of the 66 comments here at this moment, almost every comment strongly agrees with the article's premise that the US has a "bizarre disconnect between real and perceived danger when it comes to kids".

There's an obvious contradiction: How do we (Hacker News readers at least) agree that this is crazy but society keeps doing craziness like "arresting a mom for letting her kids, 8 and 9, wait at the condo for an hour".

<comment><USER11> > How do we (Hacker News readers at least) agree that this is crazy but > society keeps doing craziness

Because HN readers tend to be an extremely small subset of the general population. General population will happily vote for Trump, le Pen, Orban, Petry and other populists, which in my opinion is equally stupid with arresting parents for growing up their kids "range-free"...

More and more, I have the feeling that "Idiocracy" looks more and more like a documentation of now than a satire.

<comment><USER40> While I detest Trump and authoritarians in general (which Hillary is really just a different flavor of), I don't think you're statement holds water here. California, where I live, is the ultimate nanny state - we've criminalized the everloving shit out of everything. California has 3x as many laws on the books than the next closest state in volume, and it makes many activities, business and personal, very complex.

'Progressive' ideology places the State in greater and greater control over defining most aspects of life, and tends to turn to law and mandates more frequently than other ideological systems. This naturally drives the use of state mechanisms as a means of operation and resolution over non-legal communal resolution between individuals.

</comment></comment></comment><comment><USER41> This is why I don't want to raise my kids at all in the US. The system at large is doing everything for them to grow into incompetent imbeciles...the kind that live in their parents' basement until they are 40 and are too scared of making a commitment or raising a child until they're fifty...

</comment><comment><USER42> This is because of cable news reporting on several high profile young-girl abductions over the last 20 years. Statistically the chance is very small, but these horrible stories have been burned into the consciousness of a generation of mothers.

<comment><USER43> Cable news has severely distorted Americans view of what's dangerous and what's not, in the interest of getting more people hooked on TV.

Even very minor shark attack in Australia is blown out of all proportion until everyone thinks the wildlife in Australia is going to kill you.

It's the same reason everyone thinks Colombia, Mexico and Africa are insanely dangerous. The media/Hollywood told them so, and they believe it.

Never mind the more than 500 people a year that are murdered in NYC and another 500 in Chicago _every single year_. Nobody would tell a person not to go on vacation to NYC because it's too dangerous, but they'll talk until they're blue in the face about how you're going to be murdered in Senegal, Mauritania or Colombia.

<comment> semi-extrinsic > Never mind the more than 500 people a year that are murdered in NYC and > another 500 in Chicago every single year.

        It's a war going on outside we ain't safe from
        I feel the pain in my city wherever I go
        314 soldiers died in Iraq, 509 died in Chicago

\- K. West

<comment><USER44> By that logic, Germany in the same year was a more dangerous place than either, at 700+ murders.

Lies, damned lies and Kanye West statistics?

<comment><USER43> > _By that logic, Germany in the same year was a more dangerous place than > either, at 700+ murders._

And Germany has a population of 80 million people. More than 10x the population of either NYC or Chicago, so it's actually over 10x _safer_

<comment><USER44> Exactly. And similarly, Iraq only had 150k US soldiers, so it was actually much more dangerous than Chicago. Which is why Kanye West's comparison is nonsensical.

<comment><USER43> > _Which is why Kanye West 's comparison is nonsensical._

When you think about it from a media perspective, I think it's actually very insightful.

The American public was up in arms about the death of 314 soldiers on foreign soil, but seemingly oblivious to the >500 killed right at home in just one city in the good 'ol USA.

Surely all lives are equal, and it doesn't matter _where_ a person is killed, but only that they are killed. For every minute of airtime given to the deaths Overseas, more than that should have been given to the deaths in Chicago alone. And NYC, and Baltimore, etc. etc.

It wasn't. The media is not giving an accurate representation of real life, and now people are making life decisions based on that false picture.

<comment><USER45> > Surely all lives are equal, and it doesn't matter where a person is killed, > but only that they are killed.

Why do you think this? There seems to be very little basis for this in fact, and surely certain deaths are more tragic than others (surely and elderly man's passing is less tragic than that of a heroic soldier defending his brothers).

<comment><USER46> > surely and elderly man's passing is less tragic than that of a heroic > soldier defending his brothers

I can't tell if this is sarcasm or not.

<comment><USER46> I am downvoted, so I guess this was obvious sarcasm?

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER40> The shift toward more laws, police incidents, and over-regulation of ordinary parental duties isn't isolated, nor is it surprising. The US is a country that has been on the path of abandoning individual liberty in favor of paternalistic, authoritarian statism for decades. The real irony is that people are expressing dismay about issues and outcomes such as this, while in the same breath supporting piles and piles of evermore invasive laws that dictate how others should live their lives. When you replace the state as the primary actor in so many areas that were once the role of parents and community members, you get the state handling things the most common way it knows how: by force and criminalization.

</comment><comment><USER47> I am glad I grew up boomer times when we didnt worry about crazy shit like this.

</comment><comment><USER26> Yeah yeah yeah. Everyone is talking big here about how "obviously" these inflated concerns about child safety are absurd and ridiculous.

But how many of you would step up to slap down those morons who berate parents for leaving their kids in the car for 30 seconds?

THAT is what is needed. It is no good to simply THINK that these people are going overboard. We have to actively STOP the stupid busy-bodies from assaulting those poor parents.

</comment><comment><USER48> Some people I know occasionally call this natural selection. If you kid can stay alive/safe in safe conditions ...

</comment><comment><USER49> Anyone know when and who made these laws? Is this the case of government doing a little too much?

<comment><USER50> Too much? Maybe just the wrong things. It's easier to get votes passing feel- good "protect the children" legislation than, you know, a budget.

</comment></comment><comment><USER51> As a bicyclist, I've observed some interesting parallels: It's become virtually impossible to have a civil discussion about helmets or stop signs.

<comment><USER52> I get the stop sign anger, but helmets? Drivers really think bikers should be required to wear helmets?

<comment><USER51> I'm of two minds about it. On the one hand, I wear a helmet myself, most of the time, and using one seems to make sense. I don't bother with a helmet if it's a short trip on tame roads, such as the 1/2 mile from my house to the grocery store. On the other hand, I can't point you to supporting evidence for a benefit to making helmets mandatory.

<comment><USER53> I can.

> Wearing a helmet reduced the risk of head injury by 63% (95% confidence > interval 34% to 80%) and of loss of consciousness by 86% (62% to 95%).

[http://www.bmj.com/content/308/6922/173?linkType=FULL&ck=nck...](http://www.bmj.com/content/308/6922/173?linkType=FULL&ck=nck&resid=308/6922/173&journalCode=bmj)

> Bike helmet use increased significantly during the first 4 years of the > campaign and again after the helmet law was implemented. The total number of > bike-related head injury admissions declined by more than 50%.

[http://www.jpedsurg.org/article/S0022-3468(00)15165-6/abstra...](http://www.jpedsurg.org/article/S0022-3468\(00\)15165-6/abstract)

And a paper that speaks directly on your topic, the effects of legislation mandating helmet use:

> The rate of helmet use rose dramatically after legislation was enacted, from > 36% in 1995 and 38% in 1996, to 75% in 1997, 86% in 1998 and 84% in 1999. > The proportion of injured cyclists with head injuries in 1998/99 was half > that in 1995/96 (7/443 [1.6%] v. 15/416 [3.6%]) (p = 0.06).

[http://www.cmaj.ca/content/166/5/592.short](http://www.cmaj.ca/content/166/5/592.short)

<comment><USER54> I'd bet you could find similar improvements to occupant safety if car drivers and passengers wore helmets, and racing style harnesses. Would it be reasonable to mandate them?

<comment><USER55> Bikes don't have airbags, crumple zones, and seatbelts already in place. Helmets are likely to move the needle a lot more there than in a car.

</comment></comment></comment></comment></comment></comment><comment><USER56> Yet still things like Harambe happen, where the Mom was clearly negligent, not noticing her child climbing a three foot fence into a gorilla cage the entire time she was right there in front of it.

It's a shame, the outcome ended up costing the innocent gorilla's life instead of the Mom's:

[https://www.youtube.com/watch?v=Py_1aCt2c0s](https://www.youtube.com/watch?v=Py_1aCt2c0s)

<comment><USER57> I have 3 kids under 3.5. It only takes seconds to have stuff happen.

The three year old throws his sunglasses on the ground and starts fussing for something and you turn to deal with that and then boom your 2 year old is 15 feet away and running the other direction or making national news headlines.

If you don't have multiple kids you literally have no clue what it's like, especially if you happen to be outnumbered at the time.

Now, I'm not saying she wasn't negligent because I wasn't there- but I also know that you can be on point 99.99999% of the time and still wind up with a serious problem or worse.

And, frankly, why is the gorilla's life worth more than the mom's? Why is his life worth more than the child's? Was Harambe going to cure cancer, lower the world's greenhouse gas emissions, or become an astrophysicist that could help us colonize other planets? Was Harambe going to lead the charge on saving all the other gorillas in the world?

It sucks that he had to get killed because of an accident, but what kind of person actually thinks that in a decision between a fucking kid and a gorilla that the gorilla should win? That kid literally represents the continuation of humanity.

<comment><USER58> Most people value (some) animal life above human life. Could be because nature is sold as an innocent paradise free from sin, or that every animal is the noblest creature on Earth or just because we all have experience with assholes, while our only experiences with animals are them being majestic on the National Geographic Channel. Try giving people the trolley problem with 5 golden retrievers and one adult human male.

Edit: or as one internet meme put it:

A child has fallen in the gorilla enclosure. You hold a gun with one bullet and you can choose to shoot the gorilla to save the child. If you do so, he will make national headlines and lead to discussions that question our morality. If you don't, the child might will be rescued and the gorilla will live out his days in peace in the gorilla enclosure, completely unknown to the world. He will not be as famous. In the end, what do we value more: Harambe or the _idea_ of Harambe?

<comment><USER59> > _Most people value (some) animal life above human life._

 _/ me puts on flameproof gear_

Since this started with a gorilla... From a purely numbers-based point of view, it actually makes sense. Death of a single member of near-extinct species has a negative impact on the viability of that species. A death of a single human (or even few of them) will not make a difference. Not on a planet where human overpopulation is an increasingly pressing problem.

Even if you disagree with the idea of conservation, at least have some sympathy for the future Epicureans. By driving species into extinction, we are depriving those future society members of experiences they might otherwise have.

[insert end-of-sarcasm tag here]

<comment><USER57> I get that you're making a sarcastic comic but the funny thing is that I don't even hear people making as eloquent a point as your joke is pretending to make. Most of them are just "because animals and horrible mom".</comment></comment></comment></comment></comment>


An Experiment That Changed How We Think About Reality - <AUTHOR> http://www.wired.com/2014/01/bells-theorem/

<comment><USER2> How does this relate to Wired's other article on the pilot wave explanation of quantum mechanics?[1]

"To some researchers, the experiments suggest that quantum objects are as definite as droplets, and that they too are guided by pilot waves — in this case, fluid-like undulations in space and time. These arguments have injected new life into a deterministic (as opposed to probabilistic) theory of the microscopic world first proposed, and rejected, at the birth of quantum mechanics."

[1] [http://www.wired.com/2014/06/the-new-quantum- reality/](http://www.wired.com/2014/06/the-new-quantum-reality/)

<comment><USER3> It's explained in the footnote of the article. Bell's experiment rules out local hidden variable theories but it's still possible to formulate non-local hidden variable theories that work.

</comment></comment><comment><USER4> This is very confusing. "But according to quantum mechanics, the answer is 50%". How is this so? The article doesn't mention how quantum mechanics explains what is going on, just that "classical physics" doesn't.

<comment><AUTHOR> Thanks for pointing that you. My goal was to point out an empirical observation that can't be explained by a local hidden variables theory. You're right that I didn't explain how quantum mechanics predicts the same result, because that's tricky to do in the scope of such an article.

Here's a little more on that: One way you could do this experiment is to create 2 entangled electrons. Measuring the spin of an electron in the x, y,or z direction corresponds to the 3 doors on the box. Spin in a given direction is a binary variable for an electron (up or down) so that corresponds to the color of the light in each door (red or green).

Since the electrons are entangled, if you measure the spin of one of them in the x direction (say), then this also constitutes a measurement of the spin of the other particle in the x direction. And you can show using quantum mechanics that if you measure the spin of an electron in the x direction, the spin in the y or the z direction will be up with probability 50% and down with probability 50%. I left this as an empirical fact because I don't know how to explain it with actually resorting to doing quantum mechanics.

<comment><USER5> Classical physics ALSO says that the other two directions have a 50% probability of being red/green regardless of the value in the x "door".

With the quantum as stated above you still won't get 50% on random "doors", because there is a chance that you open the same "door" on both particles increasing the probability of getting a match beyond 50%?

To avoid having 55% on random doors, you'd need < 50% on the non equal "doors", which implies something other than even chances.

(Quantum is beyond me I suspect!)

</comment></comment></comment><comment><USER6> In Brian Greene's book "Fabrics of the Universe" he also mentioned some other experiments that completely shattered our understanding of reality. One such was the quantum eraser and especially delayed choice quantum eraser, which COULD mean causality can be violated.

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

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

<comment><USER7> Just tried finding this book you recommended.

I think it's "The Fabric of the Cosmos" [http://www.amazon.com/Fabric-Cosmos- Texture-Reality-Penguin-...](http://www.amazon.com/Fabric-Cosmos-Texture- Reality-Penguin-ebook/dp/B000XUDGV2/)

<comment><USER6> You are right, I messed up the name :)

</comment></comment></comment><comment><USER8> Why do the 3-color passport stamps have to be distributed normally? If some patterns were more common than others, than couldn't it explain the 55.55%?

<comment><USER9> That wouldn't matter (at least as I understand the article explanation). There's 2^3 = 8 different stamp configurations, two of which (RRR/GGG) trivially have 100% match likelyhood. The other six are all equivalent, and they all predict the same thing. There's (3 choices of doors) * (3 choices of doors) = 9 ways to expose the stamp configuration, and in any of the six equivalent stamps there's five ways to match colors to four ways to differ, 5/9 = 55.55%, the expected distribution. [1]

The problem is that quantum mechanics predicts (and experiments show) that the distribution you actually get is 50%, which is lower than what you would expect no matter what stamp configuration you get.

On the other hand, it's possible that the way you choose which door to open is not distributed randomly. One of the ways to reconcile Bell's theorem is that there's a passport stamp that mind-controls you into picking doors with a 50% distribution. It's not a very popular theory, but it exists. [2]

[1] Assuming RGG without loss of generality

      1-R 1-R = Match
      1-R 2-G = Miss
      1-R 3-G = Miss
      2-G 1-R = Miss
      2-G 2-G = Match
      2-G 3-G = Match
      3-G 1-R = Miss
      3-G 2-G = Match
      3-G 3-G = Match

Five matches to four misses.

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

</comment></comment><comment><USER10> There is a gem of a book recommended at the bottom of the article - "boojums all the way through".

</comment><comment><USER11> Is it possible that the 3-door box is not doing the same thing as the 1-door box? By this I mean that the 1-door box is measuring some hidden variable that the 3-door box is not measuring?</comment>


The billion-dollar bet to reach human-level AI (FT subscription needed) - <AUTHOR> https://on.ft.com/2KjM698 <comment><USER2> Sounds interesting, but blocked by paywall.

<comment><AUTHOR> Oh yeah I should add that on the title

<comment><AUTHOR> Just added</comment></comment></comment>


Dashboard UI refresh - <AUTHOR> https://blog.github.com/2019-01-16-dashboard-ui-refresh/ <comment><USER2> I have been testing the new dashboard UI since Jul 26, 2018.

[1] [https://blog.github.com/changelog/2018-07-26-dashboard- publi...](https://blog.github.com/changelog/2018-07-26-dashboard-public-beta/)

</comment><comment><USER3> Full-width layout with more columns is great, I appreciate less wasted space.</comment>


Elliptic Curve Cryptography for Beginners - <AUTHOR> http://blog.wesleyac.com/posts/elliptic-curves <comment><USER4> So far, the best single-page elliptic curve primer for generalist programmers I know of is Adam Langley's:

[https://www.imperialviolet.org/2010/12/04/ecc.html](https://www.imperialviolet.org/2010/12/04/ecc.html)

I understand the urge to try to get a high-level grok of curves without much math, but I spent years bouncing off the outermost surface of curve understanding by trying to start with the curve picture and the intuitive geometry of curve shape, and what finally made curves click for me (and quickly) was to simply take the curve equation --- which is itself high school math! --- and play with it a bit.

So if you're a programmer and you want a baseline understanding how curves work, do what you'd do with any other subject you're trying to understand: pop open an editor, take the Weierstrass curve equation, pick a y, solve for x; then do it in a finite field (ie, mod a prime). Then write an "add", then a "scalar mult". It's a couple hours of noodling, tops.

As always, but particularly with curves, remember that the basic understanding of what's going on is nowhere nearly enough to ever use them safely!

<comment><USER5> The common advice of, "You'll never know enough to use them safely so don't bother trying, just trust us." that has been going around has been proven itself to weaken encryption.

Just recently, an amateur programmer with very little background in cryptography discovered a flaw in libsodium in the Argon2 implementation and also in the reference implementation that everyone in the world was trusting without question. My advice is if you're an engineer, don't be afraid to write your own implementation of tried and trusted ciphers. This is how we find bugs and improve. This isn't the only trusted library or algorithm that has been shown flawed in recent times.

The strength of your cipher implementation can be tested and proven. We need to stop telling everyone these algorithms are absolutely trustworthy so don't try understanding them or implementing them. Nothing ever advances or improves that way. Buck the trends, create competing libraries, try new things.

The ancient ones were not all knowing, they were doing everything wrong. Their designs are full of flaws. Deny them. We need to code ourselves out of the coming cryptographic apocalypse. Do not hide your heads in the sand and hope the world doesn't come crashing down around you.

Edit: I found the blog/website of the man I mentioned in this comment who discovered the Argon2 flaw.

[http://loup-vaillant.fr/articles/implemented-my-own-crypto](http://loup- vaillant.fr/articles/implemented-my-own-crypto)

In his own words, "There's something worrying about this bug: I was the first to discover it, in January 2017. According to Khovratovich himself, it was two years old. Now I understand why the authors themselves didn't find it: unlike me, they didn't have a reference implementation to compare to.

What I don't understand is, how come nobody else discovered this bug? If you implement Argon2 from spec, you cannot miss it. Test vectors won't match, and searching for the cause will naturally lead to this bug. I can draw only one conclusion from this:

I'm the first to independently re-implement Argon2. This 'never implement your own crypto' business went a little too far."

<comment><USER4> Honestly, I'm not sure you want to get me started here.

Believe it or not, libsodium's implementation of Argon2 is an example of libsodium going off the rails. Libsodium began as a cross-platform easy-to- build repackaging of Nacl, a crypto library designed and written by cryptographers with carefully chosen primitives. Libsodium has gradually expanded it into a kitchen sink of shiny cryptography, and as a result now libsodium users have to worry about the pitfalls of AES-GCM. Why does libsodium implement Argon2? Hell if I know. As an interface, it's actually worse than JCE, which at least had the self-respect to pretend it had a "password based encryption" abstraction.

It gets worse though, if you really want to climb down this rabbit hole with me, because I'm not totally sure why Argon2 exists either. The "bug" he found in Argon2 has actually no practical impact, so much so that the reference implementation decided not to bother fixing it. But that's because very little in password hashes actually matter. Scrypt was the last important thing to happen to password hashes, and bcrypt still works just fine.

If we want to keep touring all the weird shit that happens because people pointlessly reimplement things many of which don't need to exist in the first place, we can keep doing it all the way back to unpadded RSA-512 off a broken browser RNG, which (a) existed and (b) got me gameover on a pentest once. Maybe I should be happy about that, but I mostly find it frustrating.

My point here, though, is that you aren't going to learn nearly enough from a tutorial of any sort to safely implement curves.

<comment><USER6> > the pitfalls of AES-GCM

Can you elaborate a little on this? I ask because Noise protocol standardizes on AES-GCM or ChaChaPoly, will apps using Noise with AES-GCM face "pitfalls"?

<comment><USER6> I found this discussion which is perhaps germane, about sensitivity to nonce repetition: [https://www.imperialviolet.org/2017/05/14/aesgcmsiv.html](https://www.imperialviolet.org/2017/05/14/aesgcmsiv.html)

</comment></comment></comment></comment></comment><comment><USER7> This is pretty good! The arithmetic of elliptic curves gets very complex, but I like how you arrived at points on an elliptic curve just by defining groups and fields. It might be a slight improvement to give a short, Rudin-style explanation of the difference between a set and a field. You could do this from first principles of set theory without being so terse as to be incomprehensible or diving into the axioms; I think the stated goal of little math is fine for the audience, but at the same time such an audience might not immediately understand what "field = set with addition and multiplication defined on it" means. I think a small expansion of the treatment on _why_ the ECDLP is hard would also be good. It's intuitively easy to follow that hard problems can exist, but maybe continue on in showing why this particular hardness assumption works for cryptography (because there are many that do not).

Places to go from here if you enjoyed reading this and want to learn more about elliptic curves and cryptography related to them:

1\. [http://blog.bjrn.se/2015/07/lets-construct-elliptic- curve.ht...](http://blog.bjrn.se/2015/07/lets-construct-elliptic- curve.html?m=1)

More on an elliptic curve and constructing a hypothetical one.

2\. [https://medium.com/@VitalikButerin/exploring-elliptic- curve-...](https://medium.com/@VitalikButerin/exploring-elliptic-curve- pairings-c73c1864e627)

Elliptic curve pairings.

3\. [https://www.lvh.io/posts/supersingular-isogeny-diffie- hellma...](https://www.lvh.io/posts/supersingular-isogeny-diffie- hellman-101.html)

An intro to supersingular isogeny cryptography, which has a basis in elliptic curves as a mathematical structure, but is fundamentally different from elliptic curve cryptography.

</comment><comment><USER8> If you want to see a "from scratch" implementation using existing algorithms, here's short working snippet of elliptic curve cryptography (specifically Bitcoin's) without 3rd party libraries:

[https://github.com/wyc/haschain/blob/master/Secp256K1.hs](https://github.com/wyc/haschain/blob/master/Secp256K1.hs)

The implementation doesn't concern itself with groups or fields, but they're still very useful to make sense of the code at all. Actually, I should add some types and implement an instance of Data.Group when I have more time.

Of course, it's for fun and not production use. I didn't give the slightest thought to timing attacks, optimized performance, etc.

</comment><comment><USER9> As nice as it is, integers are not a field (i.e. most of them don't have multiplicative inverses, or 1/n usually isn't integral).

Another good writeup: [http://andrea.corbellini.name/2015/05/17/elliptic- curve-cryp...](http://andrea.corbellini.name/2015/05/17/elliptic-curve- cryptography-a-gentle-introduction/)

<comment><USER10> True, perhaps the author meant rationals.

<comment><USER11> It's usually integers modulo p (p prime), which is a field.

Edit: but yes, the OP writes "integers (Z) are a field", which is wrong. Integers form a ring.

</comment></comment></comment><comment><USER12> more in depth and just as gentle: [https://jeremykun.com/2014/02/08/introducing-elliptic- curves...](https://jeremykun.com/2014/02/08/introducing-elliptic-curves/)

</comment><comment><USER13> In case anyone here is interested in Cryptography as it pertains to Cryptocurrency specifically, here's a talk I gave recently that might be interesting to you: [https://www.youtube.com/watch?v=Fyqtl7eGQZY&t=1062s](https://www.youtube.com/watch?v=Fyqtl7eGQZY&t=1062s)

<comment><USER14> here are some videos from dan boneh on cryptography, [https://www.youtube.com/playlist?list=PL9oqNDMzcMClAPkwrn5dm...](https://www.youtube.com/playlist?list=PL9oqNDMzcMClAPkwrn5dm7IndYjjWiSYJ)

</comment></comment><comment><USER15> In the image for A+A=C (multiply by 2) I see the intersection point C, but what if you wanted to multiply by 3? That would be A+C=D and I don't see any point on the curve that the line through A and C intersects. In fact it looks like for any A you choose, adding A+A gives a C which has that property (in other words A*3=0 for any A). This is just by visual inspection. What am I missing?

<comment><USER16> Seems to have labelled "C" and "-C" in a very misleading manner. Take point A. Draw a tangent, that cuts the curve at point C. That's not the point 2A. That's the point C.

Reflect C across the X axis, and _that 's_ point 2A.

So you're not missing anything, the article is misleading at best.

In short, to take the sum of two points A and B, draw a line through them both to find a third point on the curve, reflect that point across the X-axis, and the result (which will also be on the curve) is A+B.

If A and B coincide then use the tangent at A.

The point at (vertical) infinity plays the role of the zero.

<comment><USER15> Ohh OK! Thank you. Makes more sense now.

</comment></comment></comment><comment><USER17> The article gives a nice intuition about how encryption works using elliptic curves without going too deep into the math.

I'm curious for a similar explanation for how decryption would work though; a trapdoor function is nice and all, but it's only half of the story if there is no 'way out'.

<comment><USER7> Your question (if I interpret correctly) is about how trapdoor functions work in asymmetric cryptography, which is broader than elliptic curves in particular. I can give a basic overview; in essence, you use a trapdoor function because you want something to be very difficult to compute but comparatively easy to verify. Mathematically speaking, a good trapdoor function should be such that anyone without the solution will spend a great deal of time trying to calculate it, while anyone with the solution will spend almost no time verifying that the solution is correct.

If we use RSA as an example, we can see how this works in practice:

1\. Let _n_ be the product of two large primes, _p_ and _q_. Large means 512 bits or greater in this context. Then _n_ is the RSA modulus.

2\. Select a special number _e_ such that 1 < _e_ < ( _p_ \- 1)( _q_ \- 1), and such that _e_ is coprime with ( _p_ \- 1)( _q_ \- 1) (meaning no numbers divide evenly into both).

3\. Your RSA public key is now ( _n_ , _e_ ) - you can share this publicly with anyone you want to securely communicate with. Conversely, _p_ and _q_ must _not_ be public. This is where your one-way function comes in to separate what can be public from what must be private: _n_ is part of the public key, but was generated by _p_ and _q_ , and multiplication of two primes is a one- way function.

4\. Your RSA private key _d_ is computed from _q_ and _e_ , such that for any pair ( _n_ , _e_ ) there can only be a unique _d_. _d_ is the inverse of _e_ modulo ( _p_ \- 1)( _q_ \- 1) - in other words, _d_ is a unique number such that, when multiplied by _e_ , is equal to 1 modulo ( _p_ \- 1)( _q_ \- 1). This can be expressed simply as _ed_ = 1 mod ( _p_ \- 1)( _q_ \- 1).

5\. Assuming you chose _e_ correctly, _d_ is unique and very difficult to find without having _p_ , _q_ and _e_. However, while it's very difficult to find _without_ those inputs, it's very _easy_ to find if you have them, because you can use what's called the Extended Euclidean Algorithm to compute _d_ in polynomial time given _p_ and _q_.

6\. So now you want to encrypt something with RSA. Your peer has your public key, ( _n_ , _e_ ). The encryption process to compute the ciphertext C from the plaintext P is simple: C = P^ _e_ mod _n_ (C is equal to the plaintext P multiplied by itself _e_ times and reduced modulo _n_ ). Exponentiation has polynomial complexity.

7\. To decrypt the ciphertext C in order to compute the plaintext P, all the holder of the private key needs to do is this: P = C^ _d_ mod _n_. In other words, they raise the ciphertext C to the power of their private key.

So, returning to trapdoor functions in general: why does this _work_? It works because the solution is easy to compute with all inputs, easy to _verify_ with a reduced (public) set of inputs, and extremely difficult to compute with only the reduced set of inputs (and the secret inputs are themselves difficult to find from the public ones).

Hope that helps a bit and I understood your question's context correctly! Trapdoor functions do not necessarily mean that there's "no way out", what they mean is that a set of values have a relation such that one of the values requires only a few of the values to compute a ciphertext and all or most of the values to compute a plaintext for that ciphertext. When we talk about functions being irreversible, we're specifically talking about _one-way functions_ , and those are used in the context of hash functions. Trapdoor functions are "merely" difficult to reverse.

One of the things I'm actively researching at the moment is whether or not (and how) it would be possible to construct a post-quantum secure public-key cryptosystem based on a hardness assumption derived from problems in Ramsey Theoretic graph problems (coincidentally, this problem had a recent treatment after being quietly raised over a decade ago: [https://pdfs.semanticscholar.org/1599/62064634fe10897aea300c...](https://pdfs.semanticscholar.org/1599/62064634fe10897aea300cddb3a909affe6e.pdf)).

<comment><USER18> This is a great response! But I think the person you replied to understands all this, and is wondering about the exact method (or a layman's explanation) of the same process in terms of elliptic curve crypto rather than the traditional RSA (I'm wondering the same thing).

</comment></comment></comment><comment><USER19> I always get a bit annoyed when someone tries to explain ECC with an image of an elliptic curve over the reals. The whole point of ECs over finite fields in cryptography is that they don't have any regular structure like that!

<comment><USER20> What do you mean? Elliptic curves over finite fields have tons of structure themselves, and to my knowledge, the discrete logarithm problem for ECs over reals is just as hard as for finite fields.

<comment><USER19> I'm not sure what your level of understanding is, so I'll write this reply in a way I hope the average reader can follow, though I assume you'll know most of this already - I hope I don't come across as condescending.

TL;DR: the topology of these curves is quite different over finite fields.

I first encountered what I consider cryptographically unhelpful drawings/intuition when I studied lattice-based cryptography. There's a whole field where a fundamental hard problem is finding the closest vector to a point not on the lattice. If you try and explain this by drawing a 2 or 3-dimensional example over the reals, anyone who's paying attention and proficient in Linear Algebra will ask themselves, why don't you just transpose the whole thing and then take the orthonormal projection? The problem is that in a finite field, unlike over the reals or complex numbers, orthogonal projection doesn't get you any closer to your target, so the intuition over R^2 is in my opinion very unhelpful to understand exactly why SVP/CVP are supposed to be hard, and indeed had me confused for a while until my professor pointed out I should forget "the silly drawing over R^2" which he didn't like either.

For Elliptic Curve Cryptography, I find the example of a curve over the reals again misses the point of why exactly problems like DLOG are hard - <USER2> discrete-log based crypto at the 256-bit security level over finite fields, you need an about 15k bit modulus depending on which site you look at (NIST 2016 at keylength.com is a good place to start) due to speedups from Number Field Sieving etc. THis is the kind of structure that I mean you don't get.

On EC, to get 256 bit security you need exactly 2 * 256 = 512 bits of key (slightly oversimplifying, the factor 2 is because you get the "sign of the y value" for free). The number 512 pretty much stands for the conjecture "there is no other cryptographically exploitable structure to take DLOGs over these Elliptic Curves". In fact it's not just "we haven't found any such structure" but there's an argument about heights of points (Miller '85 I think - <USER3> I'm pretty sure I've also read something by Koblitz on this) why on certain kinds of curves such structure is unlikely to exist. (Of course, other kinds of curves for fancy bilinear group stuff exist and do have more structure. And supersingular curves are another topic altogether.)

The structure you obviously do get is a group, which you can extend to a vector space over the finite field so that (x \mapsto xP) is a linear function. The security property you want is roughly "you get this group, but only this group" (and the "sign", so add 1 extra bit to your keylength) and there is no useful concept of anything like points being close to each other, continuous maps in the usual sense etc. Plot the points on an EC over a small finite field and it looks like a random scatterplot rather than a neat and elegant curve - which is the whole point of using ECs over finite fields for DLOG-based crypto.

<comment><USER20> I found your comment interesting, especially the Miller '85 reference. You certainly don't come across as condescending, so don't worry about that.

You are of course right that extra structure helps with solving DLOG. I was hoping that you could point me to some specific reasons why DLOG is easier on real/complex curves. I'd be very interested in learning these.

I don't find a "nice smooth curve vs. scatterplot" argument very convincing by itself -- you only care about a cyclic subgroup anyway. Take a complex elliptic curve, viewing it as a torus consider its fundamental parallelogram, and plot a cyclic subgroup on this parallelogram. Won't you get a nice scatter plot just the same?

Even if you can use this extra structure to find some more efficient DLOG algorithms, you could try to apply the same solution as with the crypto based on multiplicative groups of finite fields: just use larger points. My understanding so far is that the reason we don't do it is purely computational efficiency -- I'd be very interested in learning any reasons to think the contrary.

And, back to the original point, I think that the drawings of real/complex curves are very helpful when learning the basics. The group law is really best understood if you actually draw some lines intersecting the real affine part of some curve, show what happens when you draw a tangent line etc. If you confine yourself to finite fields, while it formally works just the same, the geometry is much less obvious, and talking to beginners about Cartier divisors and line bundles won't help much.

While the finite fields are the whole point of elliptic curve cryptography, they are definitely not the whole point of elliptic curves, and in fact I believe that complex case with all the extra structure is best for educational purposes.

<comment><USER19> I'm afraid I don't have a neat answer to why your first question. I did find the Koblitz paper I meant earlier but it's more about why one particular attack won't work: [https://link.springer.com/article/10.1007/s001459900040](https://link.springer.com/article/10.1007/s001459900040)

There are other reasons beyond efficiency why I would prefer people to switch their DLOG crypto to EC in practice: it's hard enough to implement - even with introductory blog posts with images - that your average developer leaves the details to an expert. libsodium for example is very well designed and written and few people think "I know, I'll write my own Curve25519 implementation" but lots of people seem to think that they understand finite fields well enough to build crypto, after all they have a bignum library and a modexp function, what could possibly go wrong?. I've seen finite-field discrete log software that is supposed to be production ready with the following problems:

      * Non-constant time implementation of "schoolbook" square-and-multiply.
      * Forgetting to check if points really are in the group, e.g. you're supposed to be working in a q-order subgroup of Z^*_p where q | (p-1)/2 but the software accepts any integer less than p as a group element.
      * Crash or infinite loop if you pass 0 as a "group element".
      * Parameters can be specified or overridden by the sender of a message and set to tiny values.
      * Not checking whether the modulus is prime.

</comment></comment></comment></comment></comment><comment><USER21> Well done, loved the use of interactive graphics. Curious if you will continue this approach, but for more advanced cryptography, or move on to other things. Would love a more in depth guide to cryptography in this format.

</comment><comment><USER22> Well written and even I understood it - recommended!

</comment><comment><USER23> I'm not aure if this page uses MathML or something like that but it does not render correctly on the iPad.</comment>


Test whether any website is blocked in China in real-time - <AUTHOR> http://www.blockedinchina.net/

<comment><USER2> I'd like to mention this service isn't 100% accurate.

For instance, my website <http://syskall.com> is shown as _not blocked_ when in fact it is _blocked_ (as are all Posterous blogs). Also, <http://google.com.hk> is shown as _blocked_ when in fact it isn't.

Writing this from an apartment in Shenzhen and regular DSL connection.

<comment><USER3> hi olalonde, i'm planning to visit shenzhen by the end of this month. quick question: can i use gmail there?

<comment><USER2> Yes, Gmail isn't blocked. Also, feel free to join <http://www.shenzhenstuff.com/xn/detail/1343813:Group:5211918>

</comment></comment></comment><comment><USER4> Blocking has been an issue for the international company I work for. The company recently switched 4000+ users to Gmail and Google Apps only to find after the facts that nearly 20% of the workforce would have little or no access to most of the Google Apps sites as they are in China (I guess a bit more testing should have been in order...).

I hacked a solution, involving stunnel for encrypted communications, ss5 (a SOCKS5 proxy server), Proxy Auto-Config files (PAC) files and the Web Proxy Auto-Discovery protocol (WPAD)... An installer is used to easily deploy the whole thing and configure the system.

PAC files are used by the browser to redirect traffic based on URL pattern matching. Instead of going through the local Internet, requests that match the rules for known bocked sites are diverted to a local stunnel service running on the user's machine (or a local server depending on the configuration). The encrypted requests are then sent to a server in Hong Kong running the SOCKS5 proxy (we actually now use multiple servers on different HK ISPs and do some load balancing for better results).

From the point of view of the user, the system is transparent: it just works, they have nothing to do once their machine is configured.

I tried many setups, but the various measures used in China to disrupt traffic required the data stream to be encrypted for reliable results.

The only issue we face is due to the really unpredictable quality of the network in China: most ISPs have limited international bandwidth and depending on the ISP, the time of day, etc there can be large variations in quality.

I need to write about this one day...

</comment><comment><USER5> And you thought testing your development environment was hard.

<http://www.blockedinchina.net/?siteurl=127.0.0.1>

</comment><comment><USER6> This service can not be accurate, as what is blocked varies within China! And even within the same city, it varies with ISP. Go figure.

<comment><USER7> Also varies based on what you've visited before. English Wikipedia works fine… until you visit the Tiananmen Square Protests article, and then suddenly all of Wikipedia stops working.

<comment><USER8> That page triggered keyword filter, it's intrusion detection system

</comment></comment></comment><comment><USER9> Interesting, Reddit seems to be blocked half of the time: <http://www.blockedinchina.net/?siteurl=reddit.com>

<comment><USER10> As other commentators have pointed out, much like the actual Great Wall of China, the Great Firewall of China is not a singular entity but rather a patchwork of potentially overlapping walls whose policies vary by ISP, city, and province.

Inner Mongolia has been having uprisings recently, it does not surprise me that reddit would be blocked there (actually, I believe most internet was severed from Inner Mongolia a month or two ago).

</comment></comment><comment><USER11> Small typo : Shenzen should be Shenzhen.

</comment><comment><USER12> blockedinchina.net: apparently not blocked anywhere in china

</comment><comment><USER13> Scribd is blocked. Not surprised though.

</comment><comment><USER14> Interestingly, google.hk is blocked everywhere (which wasn't true when I visited last summer).

<comment><USER2> It isn't blocked, it actually redirects to <http://www.google.com.hk/>. (writing this from an apartment in Shenzhen)

</comment></comment><comment><USER15> is there any similar website for Iran?

</comment><comment><USER8> plus.google.com is blocked already! That's quick

</comment><comment><USER16> a plus link to a fb blog?

delicious at the beginning, will be tedious if you keep it up ;)</comment>


The Future of Man and Machine: An Interview with Ray Kurzweil - <AUTHOR> http://singularityhub.com/2012/10/29/exclusive-ray-kurzweil-interview-with-singularity-hub-dont-miss-it/

<comment><USER2> What is the name of the 19th century Russian mathematician he mentioned?</comment>


Fake five-star reviews being bought and sold online - <AUTHOR> https://www.bbc.com/news/technology-43907695 <comment><USER2> "Mr Noonan said this effectively drove the problem underground, leading to the emergence of Facebook groups where potential Amazon customers were encouraged to buy a product and post a review in return for a full refund."</comment>


Show HN: DevDash – Creating highly configurable dashboards in your terminal - <AUTHOR> https://github.com/Phantas0s/devdash <comment><USER2> Is there a significant difference between this and [https://wtfutil.com/](https://wtfutil.com/) ?</comment>


The Mac App Store Needs Paid Upgrades - <AUTHOR> http://blog.wilshipley.com/2012/03/mac-app-store-needs-paid-upgrades.html

<comment><USER2> The consensus among all the devs I've talked to is that this feature will magically appear the next time Apple does a significant update to one of it's bigger ticket apps... Final Cut, Aperture, Logic, etc.

I can't see any way they can get around this problem without adding paid updates.

Until then 3rd party developers are high and dry.

<comment><USER3> Which honestly underscores one of my biggest complaints when working inside Apples ecosystem. I always get the feeling that they're building solutions for themselves first, and developers second, they don't take an agnostic approach to creating a platform. A good example of this is when you look at their UIKit and Appkit frameworks, all of the components were designed to the specific behavior that Apples engineers wanted at that time, with no thought on how to easily extend them. Compare this against other frameworks that were intentionally built to be easily skinnable and customizable.

<comment><USER4> I can't think of a better endorsement of a platform than the creators investing real development dollars into using it.

The alternative is Google, who doesn't release any top-tier paid apps on Android or Chrome Web Store. Or host anything important on Apps Engine.

<comment><USER5> "The alternative is Google, who doesn't release any top-tier paid apps on Android or Chrome Web Store."

Google's business model isn't to release paid apps on their stores. They have many free apps that are downloaded by the 50's of millions and have 4.5-5 stars almost across the board so, yes, they do release top tier apps.

<comment><USER4> > Google's business model isn't to release paid apps

This differs from every OS vendor I'm aware of in the past. Just noting.

> they do release top tier apps.

Could you point out to me some of these apps where the alternatives are sold for top-tier prices?

<comment><USER6> Compare Google Navigation on Android, to TomTom on iOS. Navigation is free, works perfectly, and even goes so far as to include a "Car Mode" for docking your phone in your car.

TomTom costs, at last check, $95NZD. I've not bothered trying it.

<comment><USER7> I do believe TomTom has data for offline use, unlike Google Navigation.

(I have iOS tomtom for western Europe) Also, it has voices in many languages. So it will still work when you're out of coverage/country.

Remember, 99% of the land surface has crap/non-existant 2G/3G/4G coverage.

</comment></comment></comment></comment></comment></comment></comment><comment><USER8> It's not a 1-to-1 replacement or panacea, but in app purchases can mitigate the problem—i.e. free update with new features disabled until purchased.

<comment><USER9> I was thinking the same thing, but I don't think that's sustainable, nor is it a good user experience. If you have X choices of IAP features available, are you going to test the 2^(X+1) configurations out there?

Probably the best you could do with IAP is offer current version as IAP, and roll your n-1 features back into the main app as a free update on a periodic basis (i.e., want the latest and greatest, buy it now, or wait X months/years and get it for free).

Nickle and diming your customers for features also leaves a bad taste in the mouth.

As a customer, I appreciate Apple's model since I know all updates are free and any major version changes usually warrant a new app entry (I find it annoying, but understandable, that the previous version is sometimes retired from the App store), which makes the demarcation clear of what I need to pay for vs. what I don't.

<comment><USER10> I think ianterrell's idea was that, if you're going from, say, version 2 to version 3, you release version 3 for free, but _all_ the new version 3 features are a single in-app purchase. No nickel and diming.

One result of this approach is that everybody gets _bugfixes_ for free, which users are sure to like better than a model where they have to pay for fixes.

One thing you have to decide is what to do if you then release version 4, and someone never paid for 3. Does he have to pay for 3 and 4 separately, or can he just buy 4 and get the 3 features for free? (I'm pretty sure you don't want to let him buy 4 and not have 3; that's where you start getting configuration explosion.) The latter has precedent in the packaged world, with vendors that would give you the same discount when upgrading from any earlier version.

<comment><USER11> Surely one edition only.

All new features are paid for as content upgrades currently are.

If you overhaul your code you release it first as a free demo (old language; beta), then discontinue it as you release a feature-matched-update to the single paid for version you maintain.

This reduces new features to an individual cost upgrade and ensures your existing users aren't left with an unsupported version.

This is actually a very good result for the consumer. (I'm thinking premium applications such as Audio, Photoshop etc.)

</comment></comment></comment></comment><comment><USER12> As a developer with Apps in the MAS, I can see where this makes sense from the developer's perspective. But I think it is a mater of laziness on the dev's part.

Let me explain:

From a users perspective, this would suck. It is an antiquated system. "I have to pay for an upgrade just so it works on the new OS?" Think of how many times you've had to do this in the past, and how you felt.

Apple will act in the best interest of Joe User, not Joe Developer.

Instead of paid upgrades, dev's should be providing In-App purchases for new features. Maintenance of the App should be provided for free. Win-win for all.

Now stop bitching about what the MAS should have, and start using the solution Apple has given you! :)

<comment><USER13> Your comment only makes sense under the argument that when a user purchases an app, the developer is indebted to the user to provide future functionality of any variety.

Maintenance should not be expected for free. New features should not be expected for free. How much those two pieces of work cost should be dependent on future expected earnings for the developer and the perceived value to the consumer, not on whether or not they are "expected" by users.

For an argument that starts out pandering to the "users perspective", I don't see how having a dedicated upgrade process is less "pro-user" then in-app purchases. Not only does it introduce more testing (altering the expected earnings vs. perceived value equation) but it also inserts delivery and design issues for the purchases which wouldn't be necessary with an upgrade system.

To me this looks lose(devs)-win(apple)-push(consumers)

<comment><USER14> > Maintenance should not be expected for free.

Users who purchase an app definitely expect there to be maintenance on the app. This is because we know no one tests their app to 100% perfection.

If I knew that the app I get at the time I pay is all I get with no future updates, not even bug fixes, then I'd wait several months to make sure no one else finds any bugs before I ever dare to buy the app. So developers give users the expectation of future updates and fixes to assuage user fears so that they actually buy the 1.0 release and give the developers some money to keep living on.

</comment></comment></comment><comment><USER15> The Mac software scene has always had lots of indie developers. Let's look at that scene for some facts... The indies generally charge an upgrade fee for "major" versions, and give free upgrades for "minor" updates.

Most, like Wil, do the right thing. Delicious Library hasn't had a major release in years, but it is maintained.

Others (for example, in my experience "DVD Remaster Pro" and Parallels Desktop), clearly abuse the major update system as a revenue source. They release fake major releases with lots of new skin but few features every six months or a year to rake in the dough.

Honestly, it's a mess. But the solution to me is obvious: Angry Birds from Rovio. Rovio didn't just release the thing and stop. They keep adding significant features (the game is probably 10X as large as when I bought it for the iPad). Customers feed back with great reviews. Rovio is rewarded with continuing sales and stays in the top seller lists. Meanwhile, apps like "Plants v. Zombies" are static and drop off the top lists quickly after a quick burst of popularity.

<comment><USER16> Angry Birds is one of the most popular applications for the iOS platform ever. It has sales in the millions, and this model isn't comprable for indie software that doesn't have that big of a potential market.

Rovio also just released Angry Birds in Space, which is a separate app, meaning they'll get new income from it. But because it's a $0.99, giving existing customers a discount isn't important.

</comment></comment><comment><USER17> Perhaps the incentive is the wrong one. If the goal is to get users to upgrade, offer a launch sale that entices existing and new users to upgrade.

I don't think it's so terrible that there is multiple versions out there. Reduce the price of the older version and setup the page to let people know there's a new one out there before buying.

</comment><comment><USER18> I feel like the solution isn't paid upgrades but instead monthly/yearly subscription for access in the Mac App Store. The 'appification' of the web is eliminating the idea of major release "versions" of software...it's just an app in consumers' minds and it will always be the same product (with gradual improvement of course). As a result, just charge users for ongoing access to your app and keep them paying by providing regular updates.

<comment><USER19> I had an idea for a subscription service that would give developers a share of the subscription based on how much their app was used compared to other apps. That may work perfectly for the Mac App Store.

So I pay 10 dollars a month to have access to the MAS and I download 3 apps. I use App A 50% of the time, App B 20% of the time and App C 30% of the time. (To keep the math simple lets pretend Apple doesn't take their share). App A's developers would get $5 a month, App B's developers would get $2, while App C's gets $3.

Maybe to handle the Pro apps like Final Cut you could have different subscription tiers?

To users, this would be a simple netflix like subscription model. Developers would have an incentive to make their apps more useful and engaging. (I'm sure it could be abused too)

<comment><USER20> Interesting idea and somewhat akin to how music streaming pays the artists (well, the labels mostly). The challenge, as you allude to, is that software is a lot less homogenous. You only do one thing with a song--listen to it. You use software in a lot of different contexts and it's not obvious that time running is going to give equitable results. And Pro-ishness is also very context-dependent. For me, Final Cut might be a hobby thing. For you, it might be something you depend on for your livelihood.

That said, I do think we're going to see more experimentation with subscription models. Adobe's Creative Cloud is one example. I could imagine some sort of aggregator of games as well.

</comment></comment></comment><comment><USER21> I really like how most applications in the iOS store have been about upgrades. When a new version comes out I get it automatically without paying. Camera+ is a great example.

Because the user base for the platform has been growing the potential install base for your application grows with it. The graph in Wil's post shows that the same application had a huge sales surge just because more people were exposed to it.

If a new version of Delicious Library comes out his existing customers will be very happy with the new features and bring more customers in with them. I bet Apple would even promote the new app and a huge sales spike would happen again.

In my mind the new model isn't how to get the most money from your customers, it's getting the most customers.

<comment><USER2> The constant expansion model works for some apps, but not for all of them.

I appreciate the free upgrades as much as the next guy, but without the paid- upgrade option niche products will suffer.

</comment></comment><comment><USER22> I think this is mostly a mismatch in expectations. _"pay full price, suckers"_ only rings true if it's not actually a major release - small features, security/compatibility updates should be free. A new version should offer enough benefits to be worth the price.

<comment><USER23> I don't know if I agree with this sentiment. Take the author's app, "Delicious Library 2". The main functionality of this app is to catalog your things in an easy and streamlined way. I'd reckon that most people are paying the ~$35 for this app to do just that.

If the developers develop a whole new set of features (while still building off the core functionality) that they could call "Delicious Library 3", but are actually fully compatible with Delicious Library 2, why should they have to ask their users to pay full price for an upgrade, when they already have the core functionality which is the draw for the new users to pay full price.

I've seen positives and negatives to this model in video gaming. I love seeing a full-feature expansion to a game I own, and don't mind paying $5 - $20 in addition to the $60 I already paid, but I wouldn't be happy paying $60 again for the "complete" edition just to get the expansions, but that "complete" edition is great for people who haven't already purchased the game.

</comment></comment><comment><USER24> "I've looked at clouds from both sides now..." I've been an app developer and an app buyer. As a developer, of course I want to get more money from my installed base. They're easy to find; marketing costs are essentially zero. As a buyer, I've always looked at "upgrades" as a scam to suck more money out of my pocket for a product I've already paid for. I hate it more when I'm paying to get bugs fixed - bugs as a money-making opportunity! - and even more if I'm blackmailed into upgrading by the threat of dropping support for my existing product, which, of course, will stop working about 10 seconds later. I have some software that seems to be "upgraded" for a "discounted price" every two or three months!

How about you stop treating software like fresh fruit delivered with a worm in it and start treating it like, say, new cars? Sell it with a warranty. Allow me to extend the warranty, up to a point, for a reasonable price that covers maintenance only. If I have a reason to buy a shiny, new 2013 BozoWare, and the reason isn't that the 2012 model is already broken, I just may. Some people buy new cars every year; everybody buys a new one sometime.

</comment><comment><USER25> I assumed that Apple would add upgrades way back when but I now think the in app purchase model is better. Consider the reason for upgrades: new features? Sell them. Compatibility or big fixes? Why aren't these free for all customers?

The one missing thing I think Apple needs is a neat mechanism for allowing existing apps to be upgrades into app store apps.

<comment><USER26> Compatibility or bug fixes aren't free for all users because just like features, the developer had to spend time building them and needs to get paid for that time.

<comment><USER27> I build a house for you for $X. You find out that the lights don't work and ask me to fix it. Would you be happy if I told you "Oh, sorry I messed up the electrical connections. It'll cost you $Y though, because I have to spend time fixing them and I need to get paid for that time."?

<comment><USER26> You build a house for me for $X. Two years later, I notice that if you hang three towels on the bathroom door on a humid day while the living room light was on, the door didn't close properly. Would you be happy if I came to you and demanded that you debug and fix this problem for free? Didn't I pay for a working house the first time?

I very much do not believe that you paid me enough for me to guarantee that my product would work in all circumstances forever. If you did, then by golly I'm yours for life buddy!

<comment><USER27> If the problem is due to my poor worksmanship and it has always been there since the very beginning (even though you may not have noticed it for 2 years), I'd gladly fix it for free. Of course, with a bathroom door you'd have to prove it's not due to wear and tear, but this doesn't apply to software - the bits in your binary don't change with time.

</comment></comment></comment></comment></comment><comment><USER28> Can't we just hop over to a subscription model altogether, now that we pretty much have the infrastructure?

It would lower up-front costs. I bet piracy would go down too. It would give developers an incentive to keep even small apps bug-free. It would make more sense for apps like Instapaper where the server needs to keep running. Everyone would get exactly what they pay for, and nobody would have to keep using an older version for artificial (financial) reasons.

The only downside I can see is that people cannot decide to stick with an older version because they actually _like it better_. But that's something that Apple customers are probably used to (e.g. surprise 10.6 users, no OTA contacts & calender sync for you anymore!). And for Apple, it may decrease vendor lock-in because people have no sunk costs anymore.

</comment><comment><USER29> Something similar that the Mac App store is killing is the competitive crossgrade. It used to be a boon to buy Logic at full price, then be able to buy its competitors like Digital Performer or Cubase for half price. Currently the App Store can't support that.

</comment><comment><USER30> You could use in-app purchases to unlock new features.

</comment><comment><USER31> Considered charging less for the full product (say $10), and simply having multiple versions available as you post major new releases?

That way, users always have a way to downgrade to previous versions as needed, you probably get more customers due to the entry price, and everyone just understands that the latest version is available for $10 more.

That seems to be the whole app store model: lower prices, more sales -- no "upgrades" in the classic sense. And, with a low enough entry price, I think users would be accepting.

If they don't buy the latest, as a developer you're no worse off than you are today (where they get the latest for free).

</comment><comment><USER32> I want to say something about sharecropping, but I have a hard time thinking of the appropriate analogy.

It's making me think about the service model as being a superior revenue stream, for-better-or-for-worse. From a user's perspective, the MAS already acts as a service; the subsidy is just being paid for at the developer's end of the scale.

I love the iTunes/MA stores as a marketing and distribution channel, but I hate how heavy handedly Apple behaves with enforcing business models. I think there's an argument to be made that we can avoid the Android marketplace crapware without forcing everyone to become serfs.

<comment><USER33> > _without forcing everyone to become serfs._

Calling people who _willingly_ cede less than a third of their profits for access to the giant infrastructure and advertising Apple has at their disposal is a bit of hyperbole. It's a mutually beneficial arrangement for both parties, which both parties are free to sever at any time. Doesn't seem like serfdom to me.

<comment><USER2> Obvious hyperbole is obvious. IMO, the analogy stands. I'm not the only one who thinks so [http://www.codinghorror.com/blog/2011/10/serving-at-the- plea...](http://www.codinghorror.com/blog/2011/10/serving-at-the-pleasure-of- the-king.html)

<comment><USER34> Wil Shipley makes a living selling a popular Mac application both on and off the Mac App Store.

Jeff Atwood has from what I can tell never shipped shrink-wrap software as an ISV on any platform (I don't mean that derisively).

<comment><USER2> I don't see them disagreeing. They're both saying "here are some issues I see with the Apple/Developer relationship".

<comment><USER34> Non sequitor. The comment thread you're on argues that developers on Apple's Mac platform are sharecroppers. Atwood may well think that (it's not totally clear to me), but Shipley clearly does not: he is making more money after adopting the App Store than he was before it, and is content with the control/promotion tradeoff. He says so explicitly in the article we're commenting on.

<comment><USER35> Maybe the use of the word sharecropper has changed recently with respect to Apple, but as far as I know, it doesn't have anything to do with whether or not you're successful and content with the Land Owner's restrictions. It's meant to signify that you don't have full control over the ecosystem you're living in and that you owe part of the profits you reap from your hard work to the land owner.

In that sense, App Store developers are very much sharecroppers whether they enjoy and accept it or not.

</comment></comment></comment></comment></comment></comment></comment><comment><USER36> _Apple's not keeping iWork up-to-date despite sitting on one hundred billion dollars._

And here I was blissfully unaware that Pages and Keynote had rotted into uselessness simply because of the calendar year.

<comment><USER37> Have you used Pages recently? It's got a button in the default toolbar to "Publish on iWork" which has never been out of beta and is now cancelled. It doesn't work in HiDPI modes of Lion. It doesn't support Lion's keyboard macros. I wrote one letter in it last week and ended up filing three different bugs.

So, yes, software does "rot," if it's not kept up-to-date with the latest operating systems and, to an extent, the latest user interface metaphors.

</comment></comment><comment><USER38> I'm sorry I didn't read the whole thread and I know this is late.

Why not provide two versions of Delicious Library Inf? One costs $20. It only works/installs correctly if you have the original app. The other one costs $40. It is a standalone app. Make a minor bugfix update that says "hey" to the users of Delicious Library 2, and link to the expansion. Sell both.

</comment><comment><USER39> I was just thinking about this last week.

Eventually, nearly all your users have already paid, leaving you unable to charge them for enhancing the app. You may have a huge installed base and eventually have no incentive to improve the product.

</comment><comment><USER40> The App Store also also needs automatic/forced free updates. It sucks releasing something with a bug, creating an update that fixes it within a month, and still having users complaining about the bug several months later.

<comment><USER41> You could add a nag screen to your app that would show if you have a heartbeat API call that returns that the user is using an outdated version.

<comment><USER12> I do this. 90% of my users upgrade within 5 days of an update being released as a result.

"Hey! You're using an outdated version of [APPX]. Click okay to upgrade via the App Store, or Cancel to continue"

</comment></comment></comment><comment><USER42> delicious 1, delicious 2, delicious ∞--is wil a marathon fan?

</comment><comment><USER43> Who's got the open radar for this one?

</comment><comment><USER44> On a similar note, the Mac App Store really needs an option for free trials if it wants to become the premiere marketplace for apps.

<comment><USER45> Yes! Especially with more expensive software. My software costs £150: No-one wants to fork out this kind of cash without a free trial so I get very few sales through the Mac App Store.

</comment></comment><comment><USER46> no

</comment><comment><USER47> _The Mac App Store has been a huge boon to Mac software developers_

It has? Whenever I look, I tend to see trivial little apps of the same depth and quality as your typical iOS App Store app. Feels like a ghetto to me.

<comment><USER19> are you a Mac software developer? It has boosted sales of lots of already exisiting apps and gave a platform for many other apps to be shown off.</comment></comment>


Apply HN: MBAville – Business Education, Gamified - <AUTHOR> http://www.purdue.edu/newsroom/releases/2016/Q2/purdue-stude...
MBAville builds games for business education. Our first product, Project Quant, teaches Accounting, Analytics and Economics in a gamified pizzeria setting. We find the classroom to be boring and un-engaging. What better way to learn business education than by actually managing a virtual company.
Our formula for engagement is bite sized learning, gamified environment, in-game course ware and subject integration. In Project Quant, the student will triple up as an economist, data scientist and accountant. We are looking for beta testers to use Project Quant. If you find it interesting, please contact : firstname.lastname@example.com, firstname.lastname@example.com
We are a team of 2 co-founders from Purdue University: a MBA and a Masters in Computer Graphics technology. The MBA co-founder was an avid simulation gamer when young and believes that all of business education can be simulated on a massive multiplayer game featuring industries, economies and human behavior. The Computer Graphics co-founder has been building games all through his life and is very proficient in most programming languages. <comment><USER2> _MBAville builds games for business education. Our first product, Project Quant, teaches Accounting, Analytics and Economics in a gamified pizzeria setting. We find the classroom to be boring and un-engaging._

I have taken MBA courses. For the most part, I found the classroom to be highly engaging, especially when case studies are being presented. I suspect, I, like many people that have gone through graduate management programmes, will disagree with your fundamental premise. Mind you, since my concentration was operations, I have both played simulations (and loved them) and had to develop simulations. So I am not unfamiliar to games and simulations as learning tools. However its only one of many tools. Perhaps you should change the tone of your proposal since I think it would alienate the audience that would most likely buy your product.

<comment><AUTHOR> Yes. I agree with the part that this would alienate my audience. But let me ask you something about case studies. Case studies provide all the required information in the case itself. Do you believe this to be right? Don`t you think that in the real world, you are faced with many situations where available data is highly ambiguous and unreliable. As a matter of fact, I find case competitions to be more engaging since case competitions only give you a small portion of data needed to analyze the scenario. The rest of the data has to be mined by the student. This is where his or her managerial and strategic ability comes into focus. Great managers, investors and entrepreneurs are those who make reliable assumptions of missing data. Unfortunately, the case study method never lets you do anything of that sort.Would really like to continue the conversation. Thank You

<comment><USER2> _Case studies provide all the required information in the case itself. Do you believe this to be right?_

The case study is a learning tool. The required information is a starting point. It is up to the student to use the information "correctly." I recall doing one case study in a TQM course, where I was the only person who bothered to crunch the numbers and create a simple income statement which provided a powerful insight: higher than projected retail prices wasn't killing the company. Rather its return and rework expenses were.

 _Don`t you think that in the real world, you are faced with many situations where available data is highly ambiguous and unreliable._

Yes. However I think you are misunderstanding me. I have a graduate background in computer science and management. I've played games. However I can't recall many times I was bored in an MBA class. All other things being equal, I don't believe MBA courses, or any course, needs gamification to keep students interested. That is not the selling point. I think more about when Alan Kay talked about the rise of "Skeptical Man" and his ability to create powerful simulations and perform what-ifs and see things from multiple points-of-view. Perhaps Y-Combinator is the wrong place to argue about pedagogy. You probably have a good product. Just the rhetoric is off-putting. Immersive long running games are definitely a part of the future of business education*. Throw in some form of integration with an ERP, you have some really powerful stuff going on....

<comment><AUTHOR> Thank You. Sorry for the rhetoric. It is unintentional and is due to my belief that a substantially better system can be created.</comment></comment></comment></comment>