Game Theory - <AUTHOR> http://plato.stanford.edu/entries/game-theory

<comment><USER2> I'm wondering, what perspective does philosophy add to game theory? All of the philosophical musings at the beginning of the article seem to describe what "moral" beings should do. This seems unrelated to what "rational" agents _must_ do, which is one of the simpler questions of game theory. Do philosophical arguments guide, for example, how one might design utility functions? I have studied enough game theory and attended enough conferences and his hasn't showed up except to argue that a definition is perhaps reasonable (and then we wait for the elegant algorithm/analysis punchline anyway).

<comment><USER3> I think game theory isn't too concerned about how one might design utility functions, it is mostly interested in what one should do when utility functions are already given

<comment><USER4> But the usefulness of game theory is pinned on the accuracy of utility functions.

</comment></comment></comment><comment><USER5> What are some good applications of game theory? Where is it used _usefully_ in the real world?

<comment><USER6> The design of online auctions and markets.

It gives some insight on how we can design bidding and pricing systems to ensure that people only ever attempt to bid what they truly think an item is worth, given what they know and what they think other bidders know.

The broader goals are to establish when these systems might be "incentive compatible" (truthful bidding) and whether or not these results are robust to variations on the assumed information structure (assumptions governing what agents know, what they think other agents know, and so on).

For the HN crowd, it seems like the related field of algorithmic game theory is more practical. It focuses mainly on the implementation and complexity of various auction pricing mechanisms.

The section on 'coordination games and conventions' is also quite interesting and related to problems in distributed computing. For instance, byzantine fault tolerance and common knowledge of global state shares many similarities with economic systems in which many dispersed agents with subjective beliefs about the 'true state' of the world wish to come to some consensus over some market equilibria or economic fundamentals such as interest rates or market prices in the presence of faulty communication and/or strategic trading behaviours.

In these cases, game theory may provide insights on more robust fault tolerant designs, and economic policies that lead to stabler, and more efficient markets.

</comment></comment><comment><USER7> Any recommendations for the best online course on game theory?

<comment><USER8> Not exactly an "online course", but these notes (used for an undergrad course on games) I found quite readable: [http://math.ucr.edu/home/baez/games/](http://math.ucr.edu/home/baez/games/)

<comment><USER9> I can recommend the book 'A Course in Game Theory' by Ariel Rubinstein and Martin J. Osborne . You'll probably need some mathematical and economic background knowledge to gain the most out of it. Note that it is more abstract than illustrative though it is aimed at a beginner in Game Theory.

The book ist free to download after a simple registration at [http://arielrubinstein.tau.ac.il/books.html](http://arielrubinstein.tau.ac.il/books.html)

<comment><USER10> That's a good book, but a bit advanced. A little bit easier is Osborne's Introduction to Game Theory.

On the heavier side, Game Theory by Tirole and Fudenberg is used in a lot of graduate economics programs.

</comment></comment></comment></comment><comment><USER11> SEP is a wonderful online resource for philosophy. You can easily get lost browsing articles for hours if you're not careful!

</comment><comment><USER12> some cool subtopics-

matching theory: how to match kidney donors with patients? how to match kids with public schools?

social choice theory: how does the voting mechanism affect the outcome? how much weight should different parties have? how can voting mechanisms be "gamed"?

</comment><comment><USER13> Very interesting</comment>


SpaceX's rise can be traced to a critical launch from a Pacific isle - <AUTHOR> https://arstechnica.com/science/2018/09/inside-the-eight-desperate-weeks-that-saved-spacex-from-ruin/ <comment><USER2> I have to say, it's surprising to me that none of the megacompanies is taking on true moon shots with their billions in spare cash sitting around.

Google's "Moonshot" department is mostly ironic, at this point. Literal moonshots have been demonstrated by SpaceX to cost somewhere in the 2-20 billion dollar range with current technology.

Makes me wonder why they're not funding more large scale research - throw a few billion at carbon sequestration, maybe?

<comment><USER3> Megacorps are usually publicly traded. They have to be careful how they spend their stacked up billions. If Monsato starts building Moon elevator, soon enough you will have high caliber lawyers fishing for Monsato stockholders to sue the corp based on suspicious that they waste their money by going away from their main objectives.

<comment><USER4> This is what gets me though and it's so confusing. If I were a stockholder of a big megacorp and they _weren 't_ spending their money on looking climate change solutions - especially the corps causing the most damage (due to future lawsuit concerns I would expect these companies to be _most_ on board; if they don't get on board then the future will consider them mass-murders and their money-making opportunities will shrink further than I outline in this post) - then I would be _leading the charge to sue for poor use of money_.

The companies are leaving trillions on the table right now by not spending their money wisely. The future economy is going to be based around climate change cleanup at the rate we're going right now and most companies are trying to _lose customers_ by accelerating global climate change to make their customers pay more money to relocate, fix environmental issues, instead of buying their products.

Our society is going to be so financially strained in the future and it is a _Direct_ result of the megacorps not spending their money in _sustainable, responsible_ ways.

They should all be facing constant lawsuits from their stockholders for not doing better to protect the environment. Since their high-payed lawyers are presumably the ones that lobbied congress in the first place to make sure environmental care was not going to be part of taxes, and in fact that they should pay nearly no taxes at all, suggests to me that they think that the public good is best taken care of by corporations. It seems the only logical conclusion of this line of thinking: if the corps don't want to pay big taxes because they think it is a waste of money, then they have to be in charge of clean air for us, bu they don't actually care about that and so we're all going to suffer and pay less for their products because we have to pay more to fix the air.

I just don't get it.

Edit: For example, how many people in North Carolina will be buying new consumer electronics this Christmas? Will it be fewer than normal, because they have to spend a lot of their own money cleaning up from a storm that was exasperating via climate change _and_ had to deal with a government that made _planning for climate change illegal_? I think so. I think fewer people there will buy iPhones this winter and fewer people there will buy TVs are even new fancy cars too. But really why are these corporations losing these sales already? It's because an area hit by a climate-change-fueled storm was unprepared by not taxing companies correctly and by the corporations themselves trying not to be taxed; so we end up with the population themselves trying to fix the errors of their government and this process takes expected money out of the corporation's hands.

But the storms will come, and come, and come, and there will be fewer opportunities to make money from people affected by climate change.

I. just. don't. get. it.

<comment><USER5> There is an economically efficient solution. Instead of taxing things we want, like job creation, tax things we don't want, like pollution.

<comment><USER6> In which states exists a tax on "job creation"? Genuine question. I know of, e.g., taxes on a company's profits (where wages are subtracted from profit before it is taxed), and I know of income taxes, which is basically a tax on personal profit. None of those would qualify as a tax on "job creation".

<comment><USER5> There are a number of taxes levied on jobs that the employer pays. Workers comp, social security, some municipalities impose a head tax, etc.

Example of head tax: [http://www.astoria.or.us/Assets/dept_1/pm/pdf/occupational%2...](http://www.astoria.or.us/Assets/dept_1/pm/pdf/occupational%20tax%20form%20revised%202014.pdf)

There was recently a big fight over a head tax Seattle tried to impose.

<comment><USER7> Seattle head tax link: [https://en.wikipedia.org/wiki/Seattle_head_tax](https://en.wikipedia.org/wiki/Seattle_head_tax)

</comment></comment></comment></comment></comment></comment></comment><comment><USER8> I'm so thankful that, thanks to SpaceX, I may finally get a taste of what living through the first Moon landing would've been like.

<comment><USER9> Its certainly pretty amazing. But the moon landing was likely to be something just totally different: I can't even imagine just how many things could have gone wrong with the technology then, how precise everything had to be in order to take people to the moon and bring them back. The kind of expertise, testing etc. required for such an absolutely critical task.... blows my mind. e.g. they only had one shot at it; they had to get it right the first time; they only had the primitive computing and communication technologies of their era etc.

Having stayed up nights to fix some critical production outages, I've felt the stress of having a company's fate hang in your hands. Cant even imagine what it would've been like to be in the Control center for the moon landing; having the entire world watching ...

<comment><USER10> They dug up some of the speechwriter's letters a while back for if things went wrong, some pretty sobering stuff.

[https://www.space.com/7011-president-nixon-prepared- apollo-d...](https://www.space.com/7011-president-nixon-prepared-apollo- disaster.html)

<comment><USER11> Those were written by William Safire, who's to speech writing what Mozart was to composing music. Previous HN discussion of what's been called the greatest speech never given here:

[https://news.ycombinator.com/item?id=14064103](https://news.ycombinator.com/item?id=14064103)

</comment></comment></comment></comment><comment><USER12> >The internal NASA attempts to derail the program were the most difficult to overcome

As much as SpaceX owes to NASA, from talking to someone directly working on SLS, it seems apparent that this is still the case and there is a dismissive mindset towards SpaceX and their potential.

A moon orbiting space station in 2028 still seems to some, the obvious next step

<comment><USER13> I can see their point though.

If you ignore cost, SpaceX still has a lot to prove. They are doing amazing things and I personally wouldn't bet against them, but the people they are fighting against have a lot higher success rate at this point, and a LOT more experience.

SpaceX is changing the game, and reducing the cost of getting to space might be what causes the next great age in humanity, but at the same time I have to say that I'm relieved that the James Webb telescope is going up on Ariane 5.

And if you worked at NASA and really want the absolute best, I can see why you'd want to avoid the "cheap" option, even if you agree that they might one day be better.

<comment><USER14> I think you said it yourself in the middle, it will never be worth sending me to space on an Ariane X, but maybe I can afford a spot on the falcon 25. That's what I find so exciting about the cheap version.

<comment><USER13> I agree, but at the same time, I don't know if I'd want to go up on a Falcon 9...

<comment><USER15> NASA is about to human-rate Falcon 9/Dragon 2.

Perhaps you'd rather have flown on the Shuttle?

<comment><USER16> It certainly had a bigger, well-paid crowd standing behind it an telling everyone that it was safe.

</comment></comment></comment></comment></comment></comment><comment><USER17> If you liked this, there's a lot more about this story in Elon Musk's biography. I enjoyed it thoroughly.

<comment><USER18> It's a tangent but I hope he will be able to slow down a little. If he burns out I wonder what will spaceX and his other companies become

<comment><USER19> SpaceX would probably be fine with Gwynne Shotwell running it, absent Musk, at this point. Perhaps they'd lose some of their media/PR attention and the daring to take chances that Musk is known for. I'd expect SpaceX would become a bit more conservative in its ambitions, and would probably continue to operate well and be very successful as a business.

It's the Apple model without Steve Jobs. Cook is a tremendous operator, he's just not a visionary or new product guy. Apple won't have to worry until the next big inflection point. SpaceX could probably ride - with modest incremental improvement - on its technology lead for the next 10-15 years.

In the case of Tesla, the best thing they could do is hire a talented operations heavy CEO and have Musk be the product lead. He has never shown himself to be a particularly talented CEO, it'd be better if he focused on what he's the best at.

<comment><USER20> I'm hugely impressed by Gwynne Shotwell, and I agree SpaceX is in good hands with her at the wheel.

</comment></comment></comment></comment><comment><USER21> What a great story. Thank you Tomte for posting this.

</comment><comment><USER22> While most details of the crucial launch were mostly hidden, Elon has shares numerous times that fate was kind to them on that day. I wish SpaceX godspeed into the future. Spacex has put sci-fi authors on notice.</comment>


Jeri Ellsworth and the demise of CastAR [audio] - <AUTHOR> https://theamphour.com/394-jeri-ellsworth-and-the-demise-of-castar/ <comment><USER2> I know CastAR didn't work out, but I'm excited to see what Jeri does next. She is a really inspiring person.

</comment><comment><USER3> Off topic, but amateur (HAM) radio needs a lot more Jeri Ellsworths. Not only is she the kind of traditional HAM who like to build stuff she isn't constrained by the notion of "the way it's always been." This pisses off some of the old-timers, but they need to have their cheese moved, IMO.

</comment><comment><USER4> The company she works for now is called Tilt Five. It will be interesting to find out what their product will be.</comment>


The Dark Side of Being a Female Shark Researcher - <AUTHOR> https://www.scientificamerican.com/article/the-dark-side-of-being-a-female-shark-researcher/ <comment><USER2> Let me resolve the ambiguity. The article is about a female researcher who studies sharks, not a researcher who studies female sharks.

The ambiguity could have been resolved as I have above -- or it could have been prevented by following the annoying practice of using "woman" as an adjective. Thanks for not doing that, Scientific American.</comment>


Ten free online courses on machine learning (2019) - happy-go-lucky https://twitter.com/chipro/status/1157772112876060672 <comment> happy-go-lucky Stanford's Probability & Statistics is now available at [https://oli.cmu.edu/jcourse/webui/guest/join.do?section=prob...](https://oli.cmu.edu/jcourse/webui/guest/join.do?section=probstat)</comment>


Microsoft Dumping Bing? - <AUTHOR> http://www.pcmag.com/article2/0,2817,2403637,00.asp <comment><USER2> "This forces Google to adjust all of its strategies to counter this threat. In so doing, Google must take its eye off the Android ball, allowing the Microsoft's Windows Phone and tablet initiative to catch up to Android."

It seems like the author believes Google is a two person company which cannot compete on several fronts.

<comment><USER3> No, I'm pretty sure Google would need to move the entire Android team to Search if it wanted to compete with a Facebook-owned Bing.

<comment><USER4> Android is the smartest things they did for their future since their platform for targeted ads.

With Android they can exert control over the mobile platforms. Google Search, GMaps, GMail are the default on all Android devices and beyond.

Now think of Apple. At some point they wanted to switch to Bing, but they didn't. Don't really know the details about why they didn't, but it's quite easy to make a guess ...

I'm pretty sure Apple stayed with Google's Search, because otherwise Android phones would've had (at least) a branding advantage (Google is a synonym for search), not to mention that Google Search is still more potent than Bing. Without GSearch, they probably would have lost GMaps too. Then the argument for Android would have been: ooh, but it comes with GSearch, GMaps and GMail. Apple is not stupid, they couldn't put iOS at a disadvantage, in a world where every other phone comes with Google built-in.

So you see, Android is the platform that keeps them relevant in a mobile world that's tightly controlled by carriers and walled app stores.

<comment><USER5> > I'm pretty sure Apple stayed with Google's Search, because otherwise Android > phones would've had (at least) a branding advantage

Apple stay with Google's Search for two reasons:

1\. It's the best search product. 2\. Google give them bucket-loads of cash

This isn't rocket surgery.

<comment><USER6> In the alternative universe where Google didn't do Android, Apple would be able to extract more cash from Google for its search placement, at the very least, since Google would have fewer alternatives.

<comment><USER5> Yes but as soon as you get into the land of hypotheticals, Symbian can be a successful product Google would lust over. Doesn't make it likely.

</comment></comment></comment></comment></comment></comment><comment><USER7> The Cnet article has actual references to the rumor origins: [http://news.cnet.com/8301-10805_3-57422061-75/is- microsofts-...](http://news.cnet.com/8301-10805_3-57422061-75/is-microsofts- bing-secretly-for-sale/)

\</comment><comment>-

Edit: The rumors seem to be the confluence of a few data points:

1\. Microsoft just sold 750 AOL patents to Facebook.

2\. Microsoft execs contacted Facebook last year about buying Bing.

3\. Yahoo is rumored to be negotiating a switch from Bing to Google. [1]

[1] [http://blog.ineedhits.com/search-news/rumours-surface- that-y...](http://blog.ineedhits.com/search-news/rumours-surface-that-yahoo- will-move-from-bing-to-google-095511220.html)

</comment><comment><USER8> Why would anyone pay for Bing? It costs MSFT almost a billion a quarter and has around 4% market share.

</comment><comment><USER4>
         From the TFA: "hooking Yahoo, Bing, and Facebook"

I can't possibly see what good can come out of that for Facebook.

Bing could be matched with Facebook, in the same way Google+ is now linked with Google's search results. However the problem is that Google's Search is a near monopoly and it would be bad for Facebook to invest too much into this ... you don't defeat a company like Google by attacking it head on (Microsoft style), instead you are better off making it obsolete. Such a union would distract Facebook from improving things that actually matter, giving Google+ time to catch up.

And hooking Yahoo with Facebook would not be in Facebook's best interests. Facebook needs to popularize its own distribution channels for news, its own online email service, its own instant messanger, its own photo sharing services. At this stage they are powerful enough to pass on cooperation and instead prefer to lock-in their existing user base, which is growing like crazy anyway.

What Facebook must really do to survive Google is to do something about that shitty mobile app. Google is winning the distribution channels on mobiles because of Android, their search engine is the default on all smartphones, Google Maps too, Gmail is more and more popular ... so Facebook can't afford to not be in this game, because I don't have trouble seeing Google+ as the default on smartphones.

<comment><USER9> Few things need addressing here:

\- Google is the one that needs to survive Facebook. Not the other way around. Right now Facebook has the more compelling advertising platform that they are only starting to use (see: mobile). If companies do start moving money across it could do some immediate damage to Google's bottom line.

\- Google Maps is going to have a rocky road ahead if Apple does plan to release iMaps for iOS 6. And given the talent Apple acquired it could be something special.

\- Google+ will never be the default on iPhone. Twitter is. Facebook will be.

The problem for Google is that they have made enemies of Apple, Microsoft, Yahoo, Twitter and Facebook. Not a good situation to be in.

<comment><USER10> > The problem for Google is that they have made enemies of Apple, Microsoft, > Yahoo, Twitter and Facebook. Not a good situation to be in.

This is in essence their current strategic problem.

<comment><USER6> With the exception of Twitter (which Google tried to buy), I think all of these companies are their natural enemies.

Apple is a natural enemy of Google for the exact same reason Microsoft is - they don't want to see their products commoditized by web apps. The Apple/Google alliance was unnatural and only lasted as long as their common enemy did. Meanwhile, Yahoo and Facebook offer core services that broadly overlap with Google's (even pre-Google+). Both are competing for the same advertisers' dollars. And Facebook's deep social graph has been identified as a threat to Google's search for a long time.

<comment><USER10> They are mutual competitors - no doubt/debate about that.

But in purely strategic terms, you cannot have a battle on all fronts, and hope to win unless you have some deus ex machina / strong advantage you can use.

An alliance at this time, will reduce their fronts, and immediately put their competitors in a fix.

Its probably one of the more better strategic moves to make.

</comment></comment></comment></comment></comment><comment><USER11> Funny that searching bing for any of the articles pertaining to this attempted sale comes up with nothing. Prove me wrong?

</comment><comment><USER12> "Tried" to dump Bing.

If they succeed, I wonder how this will affect DuckDuckGo as I understand they source a lot of information via Bing.

<comment><USER13> This was my immediate (and only) concern.

</comment></comment><comment><USER14> Facebook buying Bing to fight against Google Search would be like buying a gunboat to fight a destroyer.

</comment><comment><USER15> related to zerg-rush, perhaps?</comment>


Ask HN: I have an idea but I need help. - <AUTHOR>

I have a case design for the iPhone 4, and possible other phones too, I would like to have made and then market. However, I don't know where to start. I assume I need to have a mold made and proper drawing done. I will also need someone to mold them for me. Where do I start? I have googled and found a few sites that help with product development but I'm from the software side and this is all new to me. Any help would be appreciated. <comment><USER2> What is the case made of, and (if you can share), what makes it unique from the 10,000 other cases out there?

Depending on the material, manufacturing may consist of injection molding, milling, vacuum-form, or some combination of 1 or more of those.

You'll likely need a CAD engineer to do a proper drawing for it, depending on the primary molding method. It's been about 4 years since I last did something like this, but the general process was something like:

1) Design and model rough prototype. This was my own time/effort and about $500 in materials (for a custom server bezel).

2) Take model to a local machinist/engineer to have CAD work done and produce initial prototypes on a Haas mill - $5000

3) Take CAD drawings and such to local low-volume production house to have initial small run of units made, at a cost of ~$250/ea.

4) (I never actually got to this stage in this project). After stage 3, you'd generally do a field test looking for whatever properties you did or did not expect from the case. Does it stay on, does it wear/damage the phone, does it survive a drop, does it affect the signal, etc. From here you'd likely have CAD work done for a mold ($5,000 - $10,000, IME) and have an actual mold made ($10,000- $100,000, IME) Depending on complexity, number of parts, tolerance, etc., this can vary widely. Once all this is done, it's usually $1-$3/unit in volume (10,000 +), but again all this varies widely on a number of factors.

Very generally speaking, you're talking about probably a $30K _minimum_ investment to get your first 1,000 or so unit. Then you have to sell or distribute them.

<comment><AUTHOR> Thanks for the info! I'd rather not say what makes the case unique at this time but I have not seen anything like it on the market yet. I have a prototype almost complete that I have kind of hacked together using parts from other cases and some custom made parts of my own. I wonder if its possible to license the design to an existing case maker?</comment></comment>


Ask YC: Where have all the good hackers gone? - <AUTHOR>

My company has been trying to locate a really solid developer for a few weeks now, but the quality of developer that we've been seeing has been terribly disheartening.
Being in Phoenix, I know that there is some very good talent here. The tough part is that the market here is very, very heavily tilted towards Microsoft development. While there is nothing wrong with that (as it stands today, we're a Microsoft shop, but we're evaluating other options right now), we'd really like to find a developer who is interested in using the best tool for the job more than a developer who just wants to use the hammer they have.
So far, we've got postings up on all the major boards, and have been able to search resumes on all the sites that provide it. We're just not seeing the caliber of people that we used to be find on say, a Dice.com.
So, do you guys have any suggestions of a place that has worked well for you guys - either when you were looking for a job or looking for employees? <comment><USER2> Hmm, if your best resumes are from dice.com you are in trouble ;-)

A lot of techy news sites have job boards too. Joel On Software is a good example, I think Techcrunch has one, dailywtf, there's Startuply if you consider yourself a startup, Slashdot, 37signals. There are probably more examples that I'm missing.

<comment><AUTHOR> Our best responses have actually come from a Craiglist posting.

Years ago, dice did very well for us; not so much these days.

I'm somewhat aware of a lot of the job boards out there, but I didn't know if people had any good response from them. It sounds like jobs.joelonsoftware.com is probably going to be our next stop; but I'd like to spread out anywhere we're likely to get decent results.

I'd forgotten that 37signals has a board now, so I'm off to check that one as well.

Thanks a ton!

</comment></comment><comment><USER3> jobs.joelonsoftware.com

<comment><AUTHOR> Weird, I'm not sure who would have downvoted you for this suggestion. It was exactly the sort of thing I was looking for.

</comment></comment><comment><USER4> Well, as a multi-tool/platform/language programmer having problems finding a job, I guess I'm seeing the flip-side now.

Not that I believed it didn't exist, I'm painfully aware of the multitudes of "I'm a java guy" and "I'm a .NET guy" one-hammer-coders.

 _shrugs_ What can you say? I'm just kind of in a doldrum floating from contract to contract of random dev work. If you're super-crunched for time you could maybe do the parallel of what I've been doing lately and hire a contractor to do the work. If not, I don't know what to tell you. Hire off of here or joelonsoftware like prakash said.

Too bad you're not in Columbus.</comment>


Show HN (~ 2 months ago) course reviewer - <AUTHOR>

With all the online courses (coursera, edx, udacity) someone made a nice little site where people could vote on courses, and provide reviews of their experience.
They put it up on Show HN between 2-5 months ago and I would really love to find it again, but google isn't helping me.
Anyone remember?
Thanks in advance <comment><USER2> There was this list from reddit: [http://www.reddit.com/r/reddit.com/comments/cktxy/reddit_let...](http://www.reddit.com/r/reddit.com/comments/cktxy/reddit_lets_compile_a_list_of_the_best_online/)

I'm currently spending a lot of time at Udacity. CS101 was the first resource for learning python that I've been able to through start to finish. (Think Python is second place for me, also very good)

The one area that I still find lacking in on-line learning is math. I can't seem to find anything that's concise, interactive and effective. (Paying is not an option.)

<comment><USER3> Is [Kahn Academy](<http://www.khanacademy.org/>) not cutting it for you?

</comment></comment><comment><USER4> I think you're looking for : <http://coursetalk.org/>

Good luck !

<comment><AUTHOR> That's the one, thanks a lot!</comment></comment>


Tired of Ads and Shitty Content? Click Everything - <AUTHOR> http://www.victusspiritus.com/2010/10/17/tired-of-ads-and-shitty-content-click-everything/ <comment><USER2> Vigilantism isn't the answer. Visit the sites that publish good content and click on ads that peak your interest -- let the internet marketplace sort itself out.

<comment><USER3> Plus, 1 person doing this won't matter a bit. 10% of the people doing this probably still won't have much impact. And there's no way you can get 10% of the internet to do the same thing.

<comment><USER4> Unless you can trick 4chan into doing it.

</comment></comment></comment><comment><USER5> First off, shitty content sites don't sell ads directly (generally) anymore than good content sites do. The ads come through a network like AdSense which means all that will result in is the shitty content site getting a lot more money.

Second, it won't ruin online advertising if lots of people do this. At the end of the day all ads are converted to CPA and bid on accordingly. It's the only metric advertisers care about. They pay by CPM or CPC, which you can game by refreshing the page a bunch or clicking the ads, but the advertiser's cost will just adjust until they're effectively paying the same CPA. For instance, if half of all clicks suddenly become fraudulent, bids will decreases such that CPCs drop by half, resulting in the same amount of money changing hands.

The only real problem with click fraud is when it is applied independently to one advertiser but not the ones he's bidding against. For instance if a bunch of people click AT&T adds fraudulently but not Verizon. If the click fraud is spread evenly throughout the market it has no effect.

</comment><comment><USER6> Sounds like a new AdBlock plug-in? Automatically click all banners and adsense, etc but have the results go into /dev/null

<comment><USER7> but think of the bandwidth!

<comment><USER6> Could be delayed (e.g. when nothing else is going on, download all content)

</comment></comment></comment><comment><USER8> Why not automate it? And why not automate it for everyone else also?

How about writing a freeware system agent/daemon that would allow people to submit sites, and then everyone running that agent/daemon would automatically spider the site as one or more standard browser user-agents, so that the IPs would be different and couldn't be as easily blocked without blocking legitimate clicks. You could make it peer-to-peer and rate limiting so it wouldn't be blamed as a DoS attack client. OR allow it to do DoS non-rate limited attacks for some sites if enough clients feel that the site is nasty.

<comment><AUTHOR> Now that's hacker thinking, not bad mind you but not the right message.

It has to represent a determined social push, the hacker answer could be abused while representing only a small percentage of web browsers.

</comment></comment><comment><USER9> I've said time and again, users should be vote directly on ads. Not only will this allow those serving ads to target them better, it will also allow direct feedback on ads that are crappy in themselves.

As a side effect, this would generate reams of extremely valuable personalized data on users!

Google could modify Chrome, such that everything in the browser can be voted on. This alone would be a killer app for Chrome. (Come to think of it, they could even enable voting on UI features of the browser itself!)

<comment><USER10> Though it sounds like a good idea, I can't imagine that constantly voting on everything I see would improve my browsing experience. I mean, browsing can already be a huge time-suck: you want to add another step and tell me that it will eventually improve the ads on my pages? It's easier to just ignore them.

Hulu lets you say whether or not an ad is relevant, and although I often do vote, I'm not convinced it changes anything.

</comment></comment><comment><USER11> I just read the TechCrunch guest lobbyist post that he referenced in the article ([http://techcrunch.com/2010/10/16/crashing-washington-how- cle...](http://techcrunch.com/2010/10/16/crashing-washington-how- cleantechsilicon-valley-can-have-their-cake-and-eat-it-too/)), and wasn't at all disgusted. In fact, the guy sounded reasonable. Am I the only one?

<comment><AUTHOR> It wasn't all bad. I just woke up on the wrong side of the bed when I read it at 4am. Ignoring gov isn't an optimal solution for growing businesses. It's wishful thinking that wide scale social changes can happen outside of regulated areas.

</comment></comment><comment><USER12> I think the the problem with content-driven sites is that satisfied visitors more often than not simply close the tab/window once they are done; only a small percentage keep "foraging" for more good content. On the other had, as Direct Media discovered, decent but far from great content keeps visitors searching for more, so they are much more likely to click on an ad.

</comment><comment><USER13> Sure you will get rid of some junk content, but when ads are devalued you will be getting rid of the good content to.</comment>


How Many (Indie) Games I Sell - Part Two - <AUTHOR> http://jeff-vogel.blogspot.com/2009/03/how-many-games-i-sell-part-two.html

<comment><USER2> The game he's writing about produced average revenue of around $4500 a month for it's first two years, and is currently making around $1000 a month. That's not enough data to plot a curve, but his long term revenue for a game seems quite respectable, particularly when considering he has a stable of 12+ games that are probably all still earning some amount.

</comment><comment><USER3> For me, this was not as interesting as Part One from a business/startup standpoint, as there wasn't much more detail. But my inner "game creator" is always excited to see a small player succeeding in this crowded arena. We should all be so lucky to earn a living doing what we love - and not get sick of it after all this time.

</comment><comment><USER4> If you haven't played the "Exile" games, you should (if you can get them to work on modern systems). They're very non-linear and a lot of fun. I remember when I first bought these games in middle school.

</comment><comment><USER5> Thanks for the link, I'm surprised it drew so few comments.</comment>


Show HN:Create and share beautiful images of your tweets - <AUTHOR> https://getpersonal.io <comment><AUTHOR> Made this little tool to help people create images with texts. Let me know what you folks think. Happy to share it with you all :)</comment>


Here's To The Crazy One - <AUTHOR> http://techcrunch.com/2011/10/07/steve-jobs-the-crazy-one/ <comment><USER2> _I might argue that Jobs is the first truly transformative figure to die in an age of transformative technology. He's someone that will be talked about a thousand years from now. And the fact that he was transformative in technology just compounds the reactions to his death right now._

This. A thousands times this.

MG touches on many true points as to why most people feel so sad about Steve's passing.

However I feel like there's a deeper reason that hasn't been properly elucidated.

Or perhaps I'm just far too emotionally confused at the moment to understand why I feel the way I do.

Yes Steve died too soon.

Yes his products affected everyone they touched.

And yes it's scary to think of a future that won't have Steve's direct influence.

Ultimately the passing of this powerful man elicits an emotional response equal to the one he had on you. This varies for everyone, but it exists for many.

RIP Steve. :(

<comment><USER3> Steve Jobs is a brilliant man, but please he won't be talked about a thousand years from now.

<comment><USER4> Do we not still talk about Aristotle or Plato? Euclid, Archimedes or Pythagoras? Hippocates or Eratosthenes?

<comment><USER5> Are you seriously comparing Steve Jobs to those giants?

Listen, I don't want to be disrespectful to a man who's just died, but you dishonor him when you try to stack him up next to them.

The ideas and intellectual breakthroughs of the ancient Hellenese that have been passed down to the world through their books are infinitely of more importance than the work of Steve Jobs. This is just not a comparable matter.

<comment><USER6> kloncks is probably utilizing hyperbole in making comparisons with the great thinkers of western civilization.

That said, we _do_ still talk about Edison, Carnegie, and Rockefeller, over a century later. A millennium? Probably not, but the point is valid, even if off by roughly half an order of magnitude.

<comment><USER5> Sure, no one's saying Jobs will be forgotten to the sands of time any time soon. Yet 1000 years is a little bit of a stretch, especially when you try to size him up next to the ancient greats.

<comment><USER7> Lots of differences: for a start, much more will be remembered of our times than is remembered from 1000 years ago. Historians in the future will be trying to determine what is important from too much data.

So you'd expect that someone who rises in the general consciousness now to actually be far more impactful than the 'ancient greats'.

<comment><USER8> A better analog to Jobs than the ancient Greeks might Michelangelo, and we still talk about him, because what he did for that time was incredible. In fact it's still incredible. Jobs didn't just build amazing products for our time, but amazing products for the future as well. We didn't just fall in love with his products, we fell in love with him and Apple as well. [And FYI, I'm not a fanboy!]

This must be the first entrepreneur/capitalist/CEO that has been mourned on such a global scale, and that in itself is remarkable; there's no one who comes close. Maybe Warren Buffett, but outside of the US he's not that well- known. The only person I can think of from modern times might be Walt Disney, someone who was similarly creative, demanding, and left a cultural and commercial legacy behind.

<comment><USER9> The problem with _that_ analogy is Michelangelo's work actually _survived_ all that time, the iPhone etc's will be replaced by something from Apple or another company, and the devices will get tossed and forgotten just like all the other generations of technical devices that preceded it.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER10> Steve Jobs was brilliant and his achievements wont be forgotten anytime soon, but some of this hype is really going a step to far and i say this as an Apple user.

He has done great things for the industrial world in bringing them luxury devices to solve luxury problems, but this is a really small part of the world. Most people dont have enough money to buy his products, like all his workers at the Foxconn factories for example. Its amazing how Apple was able to keep such a clean vest while still doing many not so nice things big corporations do these days, but as long as everyone has their nice toys noone seems to really care.

<comment><USER11> Most great inventions/products start out being available to the wealthy before being cheap enough to be accessed by all. I'm sure you think of lightbulbs as commodity items now, but back when the first few lightbulbs were manufactured, only the wealthy could afford them. 50 years from now, smartphones are probably going to be so available you'll buy one from walgreens in their discount aisle.

</comment></comment><comment><USER12> This is the best thing that has ever been written on techcrunch.

<comment><USER6> While true, that doesn't really say much.

</comment></comment><comment><USER13> Odd. No attribution to that really cool logo.

<comment><USER14> Scroll all the way down just before the Crunchbase section.

</comment></comment><comment><USER15> The version of the "Think Different" ad with Steve's voice was surprisingly emotional to listen to. It's always an odd mix of comfort and sadness to hear a familiar voice that belongs to someone who's gone.</comment>


Mir Spacecraft: Worst collision in the history of space flight [video] - <AUTHOR> http://www.bbc.com/news/magazine-36549109 <comment><USER2> Strictly thinking, Space Shuttle Columbia colliding with foam was worse[0] than this.

It is amazing how Mir courted disaster[1] but ended its mission without fatalities or serious injuries. I wonder what if anything could be learned from this?

[0][https://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaste...](https://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster) [1][https://en.wikipedia.org/wiki/Mir#Accidents](https://en.wikipedia.org/wiki/Mir#Accidents)

<comment><USER3> "Shit happens." Both scenarios could have played out with opposite endings (e.g. there have been other debris strikes in previous Shuttle missions, without fatal consequences), with very small changes in inputs.

There's plenty of things to be learned from each, but I don't see anything those incidents would have in common, except "IN SPAAAACE!".

<comment><USER4> The debris collision happened about 20km up, and the orbiter began to break up at an altitude of around 70km (on the way back down, of course), so _teeechnically_ speaking neither event happened in space.

Man, my inner nitpicker really came out on that one.

<comment><USER5> There is no clear boundary of the atmosphere, so technically speaking no event ever happens in space.

<comment><USER6> Actually we've defined a boundary at 100km [https://en.m.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line](https://en.m.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line)

<comment><USER4> Yep, just because there's no clear physical boundary doesn't mean there isn't a clear line separating "in space" from "not in space."

<comment><USER5> It is a surface, not a line :)

And it isn't very clear either, since the sea level isn't very well defined as it changes all the time :)

<comment><USER4> Heh, you're doing it again! The actual water level is constantly changing, but "sea level" is typically defined to some fixed level. Although there is more than one definition to pick from.

<comment><USER5> Yes, and I can continue until you run out of definitions to cling to :)

Sea level is (presumably) defined in terms of the center-of-mass of the Earth. This center of mass is constantly changing (even as a side-effect of the rocket moving).

<comment><USER4> Changes smaller than your ability to measure them don't really matter. Especially when we're talking about being ~30km below the definition's altitude.

<comment><USER5> And here I thought this was a nitpicking subthread.

<comment><USER4> Ah yes! But at this point it only works if you're nitpicking over the definition of "clear," since the "in space" bit is now settled.

Right? Maybe I missed a nit!

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER7> If you're like me and have no intention of installing flash here is an alternative video: [https://www.youtube.com/watch?v=tM7fTLLmgbk](https://www.youtube.com/watch?v=tM7fTLLmgbk)

<comment><USER8> For others, the video linked here doesn't tell the whole story, so you're better off watching the one in the article if you want to know how it ends! :)

<comment><USER9> Here's a direct link extracted with youtube-dl.

[http://cp401491-vh.akamaihd.net/i/,mps_h264_med/public/news/...](http://cp401491-vh.akamaihd.net/i/,mps_h264_med/public/news/world/1248000/1248218_h264_800k,mps_h264_hi/public/news/world/1248000/1248218_h264_1500k,.mp4.csmil/index_1_av.m3u8)

</comment></comment></comment><comment><USER10> One thing that was unclear to me - they say that they had to retreat to the Soyuz escape vehicle as a safety measure, which is understandable. Then he says that because the space station was tumbling out of control due to the impact, they had to fire the retro rockets to counteract the spin and bring things under control again - did they mean they used the Soyuz capsule retro rockets? Or did they manage to deploy the ones on the space station itself (if indeed it was fitted with retro rocket packs)??

If they used the Soyuz retro rockets, then I would think that was a feat in itself - if they had to use the gimbals on the capsule attached to a outer portion of the station to ascertain the pitch and roll of the main structure and counteract it.

The interview was not specific, and I couldn't find any clear info via Google so thought I would ask in case anyone here might know & could clarify.

</comment><comment><USER11> Side note: The volume on BBC's media player goes to 11.

</comment><comment><USER12> This story was told better in the book [1]. Specifically the part where they used a Soyuz to re-align the space station. They didn't think it would work, because it was the first idea they came up with and it seems so genius. They spent hours looking for a second solution before trying it. Dragonfly: NASA And The Crisis Aboard Mir

</comment><comment><USER13> Another short video by the BBC about the same incident with an interview with Sasha Lazutkin, one of the Cosmonauts on the station at the time but not the one controlling the cargo ship: [http://www.bbc.co.uk/programmes/p028l07k](http://www.bbc.co.uk/programmes/p028l07k)

</comment><comment><USER14> It's time to add [FLASH] tag to HN.

<comment><USER15> It's time for BBC and other major news providers to stop serving Flash content.

<comment><USER16> Let's start small by disabling auto-play.

<comment><USER17> Unfortunately it seems like we added that nonsense into HTML5 :(.

</comment></comment></comment></comment><comment><USER18> (1997) might be a good addition to the title.

<comment><USER19> Is the article from 1997, though? It's dated as 2016.

<comment><USER20> "Mir spacecraft 1997 collision: Worst collision in the history of space flight"

<comment><USER21> That doesn't answer the question.</comment></comment></comment></comment>


The Fine Line Between Fear and Courage - <AUTHOR> http://bhorowitz.com/2011/08/08/the-fine-line-between-fear-and-courage/

<comment><USER2> The first part of this post deserves its own discussion. Deciding who is going to lead the company is the most important conversation that founders can have in the first week (or even before starting the company). I made this mistake and my employees (and mental stability) paid dearly for the next five years.

In my case, we had an early discussion that led to an argument, and it just never resolved itself. As a result, employees never really knew who their boss was and the marketplace/customers never knew who actually led the company. No one ever had the "authority" to make the call since the founders were equals in every regard, and every decision took twice as long. Even our acquirers couldn't really figure out who did what.

I would love to see Ben (or someone here on HN) share a separate post just around this topic...

<comment><USER3> If you managed to get as far as an acquisition, then it can't have been all bad.

Devil's advocate: Every decision may have taken twice as long but perhaps they were _better_ decisions as a result?

<comment><USER2> Very true... At times there was an advantage to having a counter point to every decision, so I admit that it wasn't all bad.

</comment></comment></comment><comment><USER4> _"Over the past 10 years, technological advances dramatically lowered the financial bar for starting a new company, but the courage bar for building a great company remains as high as it has ever been."_

Not quite, because technology has chipped away at least a little bit at the number of fork-in-the-road decisions that can't be undone. If a choice is easily undone it's not really a choice anymore. You can just try both options, in series or in parallel.

<comment><USER5> Trying multiple options in series or in parallel is often not the best business decision. What type of choices are easily undone by new technology?

<comment><USER4> The technological choices are the obvious ones. Should we build on this platform or that one? They're probably not the highest priority in the grand scheme, but their effects are also most systematically underestimated, I think.

As technologies add leverage the same number of people can do more. So you can get away with hiring less, and run less risk of needing to close down divisions. Or you can raise less money and run less risk of too-many-cooks syndrome in the boardroom.

I'm sure these considerations are more obvious in small internet startups that are struggling to get off the ground. My point was just that you don't need quite the _same_ amount of courage as before because at least a few life-or- death decisions have been taken off the table.

</comment></comment></comment><comment><USER5> When I started my first company I was more naive than courageous. I quickly learned that being an entrepreneur takes a huge toll on all aspects of your life. Elon Musk describes it best:

 _Being an entrepreneur is like eating glass and staring into the abyss of death_

But even after all the challenges, I still can't help being excited to take on the next challenge.

</comment><comment><USER6> I enjoy Ben's posts a lot but they do sometimes have a ring of feel-good entrepreneurial astrology about them.</comment>


The RedMonk Programming Language Rankings: January 2019 - <AUTHOR> https://redmonk.com/sogrady/2019/03/20/language-rankings-1-19/ <comment><USER2> Okay, Stephen O'Grady - here's the obvious one you've asked for:

CSS is not a programming language. ;-)

Despite that, the list is quite complete and feels reasonable. Did you try to research how languages are used in certain use cases? Which languages compete in a certain domain?

<comment><USER3> Ha! We get asked about CSS every time. Our general answer is that we try very hard not to editorialize, and let GitHub's Linguist make determinations. We do make decisions, but to date, CSS has continued to make the cut.

As for how languages are used, we spend a lot of time trying to understand that broadly, and where the rankings reveal anomalous patterns (e.g. Kotlin a year or two ago) we do more targeted research to understand those.</comment></comment>


Flying car closes in on FAA OK - <AUTHOR> http://www.bostonherald.com/jobfind/news/technology/view/20220812flying_car_closes_in_on_faa_ok_terrafugia_already_has_more_than_100_orders_for_its_279000_aircraft <comment><USER2> I think it would be more apt to call this a driveable compact plane. It clearly looks a lot more like a plane than it does a car, it just happens to be compact with folding wings and four wheels on the base.

<comment><USER3> I,too, wonder how one gets off calling this a car. You even have to launch it from an airport.

That old joke about "where are the flying cars? Have you ever heard of airplanes" misses the essential dream: To go into your garage, hop in your car and lift off and go wherever. _That's_ the flying car. Sadly, unless we make some strides in the direction of gravitational manipulation or fusion drives, I'm not sure that'll ever be a reality.

<comment><USER4> I do agree that that's the true vision of the flying car, but I think there's still room for something that is more car-like than the vehicle in the article. Something that functions more or less like a car for short trips but could replace freeway travel with air travel. And which requires considerably less training/certification than an aircraft.

Still not an easy problem. Closest is probably the doomed Moller Skycar. Once we have self-driving land-based cars (and widespread mainstream acceptance of them), a lot will open up since we could relieve the burden of human control.

<comment><USER5> I don't see how a flying car makes any sense. Instead of accidents on the ground (which are fatal enough), now you'll have them falling out of the sky.

Granted, I was just in an accident a few weeks ago, and it dramatically changed my view on driving altogether. Crashes aren't just something that happens "to someone else". People are very irresponsible, reckless, and impatient when it comes to moving vehicles.

<comment><USER4> That's why you need advanced auto-pilot before this is feasible. And bear in mind that there's a lot more room for collision avoidance in the air. You'd probably have to have something like special lanes in the air to minimize the number of directions that another vehicle could approach, and to keep them out of the commercial airspace. You'd need a special license to go "off-road".

</comment></comment></comment></comment></comment><comment><USER6> If anyone is curious to see some picture of the vehicle they are here: <http://www.terrafugia.com/photogallery.html>

It looks a little fragile to perform well as a car. I imagine a significant pot hole might be enough to damage the skin. I understand the need to be light and aerodynamic so that it is flight-worthy, but this looks more like a toy then a real solution. It reminds me of those cars that can also perform as a boat -- they do neither well, their remarkable feature is that they do both.

<comment><USER7> Good point - if as car it goes into a fender-bender. Who'd deem it airworthy?

<comment><USER8> Your A&P (Airframe & Powerplant Mechanic).

</comment></comment></comment><comment><USER9> Hrm... This seems a little like the worst of both worlds. It's horrible as a car (in the sense of something you'd drive to work everyday), and for the money it's not the most cost effective airplane either.

Many people seem to think "flying car" == "I can just launch and avoid all the rush hour traffic, and then land in my driveway". The reality of course is far different, you have to drive this to/from an airport.

I'm curious what problem this is intended to solve.

<comment><USER10> > _"This seems a little like the worst of both worlds."_

We (staff of the Museum of Flight) said the same thing about Moulton Taylor's Aerocar [0]. It doesn't do either thing very well, and that's a big reason there hasn't been a hugely successful product in the space yet.

That said, it does solve a specific problem: it cuts significant time off for those who regularly make trips in the hundreds of miles, particularly between semi-remote locations.

Imagine you lived in central Kansas, and had radio transmitters, oil fields, or clients spread all across the state. You could fly from small airport to small airport [1] in considerably less time than it would take to drive, and then have a car available to drive out to your destination.

One of the advantages this variant has over other past attempts is that it's classified under the (new) "Light Sport Aircraft" category [2]. It's much easier to get a LSA license than a normal pilots license, among other things.

[0] <http://www.museumofflight.org/aircraft/taylor-aerocar-iii>

[1] <http://www.filmkansas.com/pages/airports> \- map of KS airports

[2] <http://en.wikipedia.org/wiki/Light-sport_aircraft>

<comment><USER9> You'd have to be doing a _LOT_ of that sort of travel to offset the acquisition cost ($280K) and ongoing maintenance (???) of something like this.

Setting your own schedule would certainly be beneficial, but it would take a long time to justify that cost.

BTW, do you still have the B-17 out front?

<comment><USER10> > _"You'd have to be doing a LOT of that sort of travel"_

Of course. Most aircraft are significant investments; you don't drop that kind of money unless you've got really good reason.

That said, if you're one of the few for whom this particular use case is relevant, I can't think of a viable substitute. If you try to use a traditional aircraft, you're left needing ground transportation at various remote sites that may not have taxis. If you drive from site to site, you might end up spending an extra 3-5 hours on the road every day. So if you're running a high-revenue business that requires a high amount of travel, this (or some other flying car) might be a game-changer.

> _"do you still have the B-17 out front?"_

I stopped working there when my son was born, and left the state a year and a half ago. This is the first I've heard of the B-17 being out of its hangar, but apparently it's open for summer tours:

<http://www.museumofflight.org/b-17-boeing-bee-bomber-tour>

</comment></comment></comment></comment><comment><USER11> What's funny to me is that when cruising in the air, it gets ~25 mpg; on the ground, 35 mpg. <http://www.terrafugia.com/aircraft.html>

<comment><USER12> I'm guessing that's because you're going 105-115 mph instead of 50 mph... essentially twice as fast.

Surprising to see max speed is 115 mph, for some reason I thought it would be much higher.

<comment><USER11> A lot of US interstates have a speed limit of 80; in that case it's only marginally faster speed-wise. But, going between two points on a straight line helps too. I'm more amused, though, that it's _less_ efficient when the wheels _aren't_ touching the ground. I guess I always just assumed that air travel was more efficient than a vehicle that touches the ground, creating lots of relative drag.

<comment><USER13> You travel a [generally] significantly shorter distance when flying, and at a notably higher rate of speed (though normal cruise speed will likely be lower than max rated)

So a drop in mpg is completely understandable

Also, there is a lot more causing drag (the wings at least) when it is flying vs when it is on the ground

<comment> wes-exp Also, planes need to continually lift your weight against gravity. There is vertical force that needs to be produced in addition to the normal horizontal travel.

<comment><USER14> I thought the principal of lift means the aircraft is sort of resting on the air (in a manner of speaking) and doesn't need to produce vertical force. Much like a boat doesn't need to produce vertical force to stay above the water.

I may be completely wrong, the concept of lift never made sense to me. It always seemed like free energy.

<comment><USER15> Sort of. (And caveat: I'm a software guy, I just happen to love airplanes.)

Airplanes generate only forward thrust (unless you're in a VTOL craft which we won't talk about). This forward force is what ends up generating lift due mainly to two particular, but separate, applications of physics.

First, wings take advantage of what is called Bernoulli's principle. Picture a wing: it is longer on top than it is on bottom due to the "chamber" of the wing. I.e., the asymmetric difference in the shape of the top and bottom of the wing. This causes the air that flows over the wing on top to be at a different speed than the air on bottom, since the air on top gets compressed. (Remember that in a river, if the river narrows, the current speeds up because you still have a stable amount of water to get downstream. If the volume status the same, higher pressure = higher speed, roughly.)

So, by Bernoulli's principle, the slower air on bottom has more potential energy than the air on top -- and that results in more outward pressure by the air, i.e., it pushes up on the wing harder than the air on top pushes down (which has more kinetic energy and less potential, due to the higher speed). Because the wing is not creating energy, the air is merely converting to and from kinetic/potential.

However, that's not the entire story of lift!

Wings are also angled, with their trailing edge down as compared to the leading edge. This angle is defined as the "angle of attack". Think about it like this: when you stick your hand out of the window of your car while driving down the freeway at high speed, you can tilt your hand up and "take off". The wind hitting your hand pushes it up because of the angle. This seems kind of straightforward, right?

If you continue tilting your hand closer and closer to the vertical, at some point it falls back down. You have "stalled" and are no longer generating enough lift to fly. Airplanes do the same thing, so they have to balance the lift they generate with the other factors.

Airplanes fly mainly through the combination of these two things: lift generated by the relative difference in airspeed above and below the wing, plus lift generated by the angle of attack.

I hope that is explanatory, and if I'm wrong on anything, someone else will come correct me!

<comment><USER16> Your picture of how lift works is fairly off base.

The speed difference being due to asymmetry is wrong. Symmetric wings still generate lift by having air flow over the top faster than the bottom. Symmetric wings flying upside down also still generate lift that way. Asymmetry _helps_ , but is not necessary.

The important thing to understand about aerodynamic lift, and that few people do understand, is that the Bernoulli's principle action and the air deflection action are _the same thing_. They are not two different mechanisms which act in concert. They are two different ways of looking at _a single phenomenon_.

If you deflect air downwards, you _will_ generate a speed and pressure differential between the top and bottom of your wing. The pressure differential will produce an upward force on the wing that is precisely equal to the downward force on the air. Likewise, if you generate a pressure differential between the top and bottom of the wing, you _will_ deflect air downwards. They're two different results of the same action.

To truly understand why wings generate lift (which is the same thing as why wings generate a faster airflow over the top than the bottom, or why wings generate a lower pressure on top than on the bottom, or why wings deflect air downwards), you need to understand the Kutta condition.

A wing moving through air has two stagnation points, which where the airflow splits. There's a stagnation point at the front of the wing. Any air above that point goes over the top, and any air below that point goes underneath. At the back of the wing, the stagnation point is the point where the air from the top and bottom meet again.

The location of the front stagnation point depends on the angle of attack. If the wing is flat, the front stagnation point will be right at the leading edge. As you tilt the wing upwards, the front stagnation point moves toward the underside of the wing.

The Kutta condition says, in short, that air won't go around a sharp corner. Thus, the rear stagnation point _is always at the trailing edge of the wing_. This is why wings are shaped like a teardrop, and that sharp edge at the back keeps the rear stagnation point from moving around.

With the front stagnation point mobile, and the rear stagnation point fixed, you have an asymmetry that causes circulation. This is a rotational component to the airflow around the wing which causes air to flow over the top faster than the bottom, such that the stagnation point is at the trailing edge. This circulation causes the air to be deflected downward, and causes lift.

In summary, wings generate lift by deflecting air downwards, which is equivalent to saying they generate a pressure difference between top and bottom, which is equivalent to saying they generate a speed difference between top and bottom. Wings accomplish this by having a sharp trailing edge, which causes circulation that deflects the air. Wings are shaped the way they are not because the asymmetry is necessary to generate lift, but merely because it's more efficient that way, by changing where the front stagnation point occurs, or by generating less turbulence in the air.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER17> It is all fun can games until a teenager drives their car into the side of this and the $300K flying car needs to be replaced.

<comment><USER18> How is that different than some person driving into the side of a lamborghini?

</comment></comment><comment><USER19> This is more for pilots who want a more mobile aircraft than normal folk who want a car that flies.

Owning a Cessna means you have to pay for a tiedown or a hangar at an airport. With this, you can hangar it in your garage. The added expense doesn't really make sense, but it certainly makes it more convenient.

The same with premium laptops, people like myself don't mind paying an extra $1000 for a MacBook knowing its an easier, smoother experience. Likewise, a wealthy pilot might prefer this to a Cessna because it makes things simpler.

</comment><comment><USER20> The first 100 units will be delivered to the cartel of sinaloa, the cartel of jalisco is on the waiting list for another 100 units.

I am buying stock.

</comment><comment><USER16> I seriously don't understand the appeal of this. For the money they're charging, you could buy a great normal plane, a great normal car to use to drive to the airport, _another_ great normal car to keep at the other airport you use most often, and have enough money left over to rent cars at other airports you visit for the rest of your life.

<comment><USER21> That is the price _now_. Competition and mass production will drive that down (if not for this particular manufacturer / model, for others in the same category).

<comment><USER22> Competition and mass production hasn't brought the price of any Part 23 (not kit) plane below 6 figures.

There's less variety of engines than airplanes, so the engines are produced in greater volume, but even after years of mass production their prices are still high - a new 150-200 HP engine will set you back more than a nice luxury sedan.

</comment></comment></comment><comment><USER23> Knowing nothing about aviation, I find air planes with one engine very scary. Even when I am not traveling in it, since I don't want one to fall on me either. So I am glad we probably won't see millions of these "flying cars" being sold. If I imagine to have one of these fall off the sky as often as I see broken down cars on the side of the freeway...

</comment><comment><USER20> My dream of a flying car is a small harrier in the shape of a porsche.

Vertical take off and landing should be priority number one.

</comment><comment><USER24> This sounds cool but I'm not familiar with it. Why is it called a "flying car"? Is it the price point - is $279K significantly cheaper than most private airplanes? Or is there something in the construction that makes it more "carlike" than most private airplanes?

<comment><USER25> "Roadable airplane" doesn't get the web traffic "flying car" does.

If you just want an airplane, you can get a lot more airplane for $279k. You can get a nice new Cessna 162 for $150k.

I'm not sure what the benefit of the concept is. You're only ever going to drive it from your house to the airport and back. A routine traffic accident will be very expensive and will attract unwanted attention and paperwork from the FAA and NTSB.

If you buy a regular plane you can leave it at the airport for very reasonable tie down or hangar fees, and know it's going to be safe and well cared for.

edit: Anticipating an objection, one could posit this is good for commuters. There is actually a segment of the general aviation population that fly themselves to a job in another city and back every day. You could use a roadable aircraft to drive to the office.

I'd say it's cheaper and better to buy a car and pay to keep it parked at the airport.

Still looking for any practical advantage. If anyone thinks of one I'd love to hear it.

Just thought of another possible objection: "But you don't have to get out, you can just drive into the airport and take off"... no, you can't. You're getting out of that plane to do your preflight checks or you have a death wish.

<comment><USER26> I think the biggest motivation for me would be to be able fly to someplace, maybe a small airfield, and not have to worry about making arrangements for a rental car or find someone to pick me up.

I doubt this is the final answer, but it's a good start.

</comment></comment></comment><comment><USER27> Better headline: "Beat the TSA for under $300K".

<comment><USER28> For what it's worth, you can beat the TSA for under $30k - a used Cessna 150 can be had for around that price. The cost of a rental car at your destination will take quite a while to add up to the other $270k.

<comment><USER27> But that's nowhere near as fun.

</comment></comment></comment><comment><USER13> Terrafugia (and others) have been making fantastic technological inroads across industries: good to see the FAA is taking solid note

</comment><comment><USER29> We already have flying cars. We just call them "helicopters".

<comment><USER30> It's kind of hard to drive helicopters down the highway.

<comment><USER16> Not more difficult than flying it anywhere else. Just make sure to watch out for wires.

<comment><USER30> I didn't know flying and driving were synonyms these days.

<comment><USER16> The only difference is the altitude, and helicopters can go as low as you dare.

<comment><USER30> I assumed driving meant moving on land with a (most likely) combustion-powered platform that was connected to the land with wheels. No wheels and no ground contact sounds like hovering to me.</comment></comment></comment></comment></comment></comment>


Show HN:Analytics is complicated? Centi is the simpler alternative - <AUTHOR> https://centi.in/ <comment><AUTHOR> Any feed backs are welcome !

<comment><USER2> Are your analytics text-based or graphical? I don't see any screenshots.

Also (and I can't stress this enough), definitely get an Android app out as soon as you can. It's shocking how few good analytics apps there are available on Google Play.

Make a good Android app and you'll be printing money.

I'm currently using StatCounter and their service is good, as is their app, but there needs to be more choice out there.

Good luck to you!

<comment><AUTHOR> Thanks for the feedback , will surely add screenshots to it . Have statted working on an android app , will launch soon .</comment></comment></comment>


Ask HN: What's your favorite piece of ASCII art? - <AUTHOR>

Mine's this little dancer: ¯\_(ツ)_/¯<p>Paste yours below. <comment><USER2> /me waiting for the goatse

</comment><comment><USER3> ( ͡° ͜ʖ ͡°) and ༼ ༎ຶ ෴ ༎ຶ༽

</comment><comment><USER4> But that's not ASCII.</comment>


Vue.js Tutorial for beginners - <AUTHOR> http://adrianmejia.com/blog/2018/08/04/Vue-js-Tutorial-for-beginners-Create-a-Todo-App/#.W3NVkKA68SE.hackernews <comment><USER2> Also, a good tutorial for beginners... is the Vue guide itself, it's concise and authoritative:

[https://vuejs.org/v2/guide](https://vuejs.org/v2/guide)

Devote half a day (more or less, depending on how fast you read/take in information that you might use later), read through the "essentials" section and "components in depth" at the very least, and then get started building stuff and use the guide as a reference (and also the actual API reference).

<comment><USER3> I think the exceptionally high quality of documentation-like this part of it—is one of the reasons Vue.js has conquered the world the way it has. A lesson for anyone trying to move the needle in the increasingly competitive FOSS world.

<comment><USER4> When did vue.js conquer the world?

<comment><USER5> Please don't do this. It was obviously a figure of speech.

<comment><USER4> Why should I not ask an honest question?

vue.js obviously got more popular with Github taking it up, but I wasn't aware of another surge of popularity.

It's not an obvious figure of speech and I was curious to know if there's a sphere where vue.js is obviously dominant.

<comment><USER6> I agree with you, it's an honest question.

You might find here [0] some answers. Just the Alibaba sphere is enormous I guess.

[0] [https://www.netguru.co/blog/13-top-companies-that-have- trust...](https://www.netguru.co/blog/13-top-companies-that-have-trusted- vue.js-examples-of-applications)

<comment><USER4> Huh, that's really interesting, though I have mixed feelings about their inclusion of Facebook as #1 on the list given Facebook's relationship to react. Similarly, including Netflix due to the company using vue.js for two small internal apps is iffy.

I definitely did not know about Xiaomi or Alibaba -- those are really huge both in influence and market size.

Thank you!

</comment></comment></comment></comment></comment></comment></comment><comment><USER7> Good intro, few nitpicks:

\- it should be mentioned that components have to return data as a function [0]

\- v-for should ideally be used with keys [1]

[0] [https://vuejs.org/v2/guide/components.html#data-Must-Be-a- Fu...](https://vuejs.org/v2/guide/components.html#data-Must-Be-a-Function)

[1] [https://vuejs.org/v2/guide/list.html#key](https://vuejs.org/v2/guide/list.html#key)

One should definitely mention the vue.js docs for basics.

</comment><comment><USER8> I know it may be tangentially related, but did anyone of you try to use TensorFlow.js with Vue.js? While some setups do work, the default one (i.e. `vue create proj`) results in some strange errors (seem to be a problem with dev dependencies). More details:

[https://stackoverflow.com/questions/51812619/error-for- tenso...](https://stackoverflow.com/questions/51812619/error-for-tensorflow- js-in-vue-js-app-in-chrome)

</comment><comment><USER9> I think you need to check start-here branch. In doc it says app.js is empty, in reality its set to something similar you what should type it to. neither worked for me.

</comment><comment><USER10> Anyone else getting connection error on the site? Or have a cached version?

Edit: Strange, it works fine in Chrome but gives me an error in Firefox.

<comment><USER11> Very strange, the official vue.js guide linked in another comment gives me the same "corrupted content" error too. Unfortunately this makes me immediately suspicious of vue.js itself...

-e- FF 62.0b15 here, and both sites work in Chrome...

</comment></comment><comment><USER5> Nice tutorial!

Looking forward to the "a todo app won't tell you much about how good a framework is" type midbrow dismissals. :)

<comment><USER12> Actually it told me that simple stuff is unnecessarily complex, so that's not nothing.

[this todo list]([http://bindinator.com/#source=todo.component.html](http://bindinator.com/#source=todo.component.html)) example is shorter and does more.

</comment></comment><comment><USER13> Shes dead jim</comment>


Ask HN: So, does my startup need an office? - <AUTHOR>

I am a man of two hats, my first hat revolves around a very established business. We have customers, battle scars and have been in the space for years. Its a great company to work for, although I am very senior, I am not the founder and I wasn't there at the beginning.
My second hat revolves around my startup Powered Now. We are a 5 person team spread over the globe. Our product is a business administration platform for the Field Services world, we are hoping to launch into private beta within a few weeks.
My established business is a bit of a hybrid. We have two offices in the UK and a distributed workforce of about 20 working at home. I really get to see both the advantages and disadvantages of office / home working. It works for us, but we have been doing this for a long time and I wonder if I am being blinded by the convenience factor.
With Powered Now I have a distributed team, half of us are in the UK the other half are based in Budapest, we try to meet up to work together once every 4 to 6 weeks. When we do its insanely productive, but I wonder if it would be better if we were under the same roof?
If you believe the guys at 37 signals home working is the way forward, and to some extent I believe them, its enabled us to go to the best people instead of hiring in a limited area. However I'd be interested in your stories, have you consolidated a team into an office, or did you do the reverse? Are our productive meetups that good because they are a relatively rare event or would it be like that every day? Also if you were founding a startup today, how would you do it?
I'd love to hear your stories and advice.
Thanks,
Ben <comment><USER2> My startup began life working from home/remotely. We had a team spread between London and Brighton.

We moved into a shared office space in London which an early investor helped to hook us up with. It sucked. It was a crummy, distracting environment. A lot of people there were working on pretty weird/lame projects (including a Russian "get rich quick!" motivational speaker, who was apparently had eight- digit wealth but worked from a £100p/m office space).

Things which are poisonous to your productivity:

• "Networking" events of any kind • Talkative people who are working on projects which they don't believe in • Talkative people who are working on projects which they do believe in • People from other projects who want your advice on something • People from other projects who have heard you just did a raise and want to ask questions • People from other projects who want you to test something really quickly just this once • "Oh you must just meet this person they're so relevant to your project" • Anyone talking on the phone for any length of time (this is personal. I find it annoying to hear one-sided conversations).

We just moved in to shared office space with a YC company and another company. It has only been a week or so but already we're more productive and it feels more like "work" (in a good way). Fewer meeting rooms but fewer distractions. More focus.

Don't go to a shared workspace. You'll do poor quality work with a ton of distractions. Find another company who have some spare desks, and go there.

Working from home is not productive for most people (hence all the "HOW TO BE PRODUCTIVE WORKING FROM HOME" linkbait articles you see all over Lifehacker and occasionally on HN).

It's also a psychological help to have somewhere that you invite people: you invite investors to your office, you don't go to them. Even being able to say "we can do it at our place?" makes you seem like you have clout.

HTH.

<comment><AUTHOR> Thanks for the reply George,

Did you bring the whole team under the same roof including the guys from Brighton?

<comment><USER2> So when we hired them (just after the start of the project) they worked remotely. They were a small agency who we essentially block-booked for large chunks of time. They would occasionally come to the shared office but not regularly enough to close all the gaps on the project. I estimate that to keep things running reasonably smoothly (and there were still major problems which led to me firing them and hiring brilliant software engineers), I probably spent north of £1k on travel to and from their location to manage them, which was painful both financially (I could be spending that money on almost anything else and it would be better-spent) and emotionally (it's a lot of energy).

Now everyone is in the same room and on the same page. I'm sure there are occasional productivity hits (conversations, phone calls, stand up meetings), but it's a quick "Hey I just deployed this" instead of Email > New Message > email@example.com > I just deployed the XYZ feature we talked about > Send.

It's also more helpful for me to work this way because I am a hands on product manager. We can iterate things very quickly, I can break them and suggest improvements, and we can then iterate them again. Irrespective of whether my benevolent dictatorship is a good way of working, the fact is that I will always work like this and to do that over any kind of distance greater than 5 metres is inefficient and frustrating.

</comment></comment></comment><comment><USER3> Having an office makes such a difference to work flow and production. Also good to have a hub, where people can always drop in.

We use a number of freelancers they like to work from home, but its great they can always drop in and work in the office for a few days.

<comment><AUTHOR> Thanks for the reply Chris,

How has the office impacted the way you hire freelance staff, do you look for people within reach of your office?

</comment></comment><comment><USER4> A combination of co-working + working from home is low cost and provides space and collaboration when you want it.</comment>


A Feminist Perspective on Memes - <AUTHOR> https://metameme.app/are-memes-just-for-men-feminists-beg-to-differ/ <comment><USER2> _In the past 5-6 years, as memes have been spreading like wildfire_ Well.. a bit longer than THAT.

 _, we generally assume it's all men behind their making and sharing._ Oh do "we"?

 _There is something unmistakably male dominant about the meme industry, which means many common memes shared on the internet are rooted in male interests and humor._ It's true that men are over-represented in that regard. But it says something about the writer. To her "men" are a singular group with a "common interest". I find that highly dubious.

 _As a result, feminists are using memes to cover everything from mental health, white feminism, and sexism, to heteronormativity and the patriarchy. They are leveraging memes as a larger reflection of their sociopolitical discontent, using these funny graphics as a way to make us smile, while also inspiring us to think about the bigger picture._ ...Just like these "men" or other people do.

The submit button is not filtering anyone, go ahead with these _enlightening, eye-opening, and educated feminist memes._ Can't wait.</comment>


Ask HN:where can I find audio courses? - <AUTHOR>

Well you may be wondering why I would like courses in audio format if I can have a good set of video lectures of most topics.Here are my reasons:
1)I don't own a fancy iPod or any video player.I just have a good philips mp3 plyaer (go gear series).Which I like and is all I can afford.Don't even think about mentioning my cellphone as its a very funtional one,no multimedia in it.
2)Easy to download.They are like 15-16 or at the most 25Mb and a very quick download.Video lecture take 5x the time,besides I prefer streaming videos rather than download it.
3)Thats all I can concentrate on, while on the college bus.I travel for like 1 1/2 hrs up down (totaling to 3 hrs of wasted time listening to songs).Even if I had a fairly decent video player, I couldn't even begin to concentrate on the 3-4 inch screen.Its just too small for me.
I searched the internet and interesting (to me) course I found in audio where Game theory at open yale project[1].Thats about it. So I ask HN, do any of you use such things?Can anyone give me good links to other open audio courses.
My interests are mainly in electronics and mathematics. <comment><USER2> Apples iTunes University seems like a good adress. Quite a number of universities upload podcasts and lectures on all kinds of topics. I do not know whether mathematics and electronics are covered, but I'd guess so. They are free, so take a look there.

If you are interested in other disciplines I enjoy audiobooks on economy by the Mises Institute ( <http://www.mises.org/> ) and one of the most enjoyable podcasts on philosophy is to be found on freedomainradio.com by Stefan Molyneux.

</comment><comment><USER3> I'd be surprised if you could get good courses on either of those topics in pure audio form... but if you do, let us know, I'm sure it'd be of fairly general interest around here.</comment>


Ask HN: Does any one use PERT chart technique for software dev? - <AUTHOR> Was wondering how does one use PERT chart technique for software development in projects. Pls share your experience. <comment><USER2> Link to a description if anybody else is wondering [https://en.wikipedia.org/wiki/Program_evaluation_and_review_...](https://en.wikipedia.org/wiki/Program_evaluation_and_review_technique) (never heard about it before)</comment>


At what time, you are more productive? - <AUTHOR>

<comment><USER3> Sadly, I'm more productive around after midnight.

<comment><USER4> Me too! What's up with that? My gf always complains if I stay up late to code, I wish I could be productive as an elf whenever, y'know?

<comment><USER5> _What's up with that?_

For one thing, it's usually quieter. And people are less likely to be interrupting you.

</comment></comment></comment><comment><USER6> I'm usually most productive from 2am to whenever I fall asleep, which has been somewhere between 10am and noon as of late. Great sleeping cycle, I know :) It's almost impossible to get anything done during the day, especially on a college campus - so many distractions!

</comment><comment><USER7> For me the hour depends on how excited I am about the project i'm working on, could be night, morning, doesn't matter. However my best ideas happen at night.

</comment><comment><USER8> My so-called "day work" is usually from 10am-10pm and I tend to be more productive from 6 -8(pro-dinner). Side-project-wise maybe 12-2am.

</comment><comment><USER9> I find myself focus better after 11pm to whenever i sleep. Probably because there's less distractions around this time of the day.

</comment><comment><USER10> Wow, same as everyone, I'm most productive at night until morning.

</comment><comment><USER11> I tend to be most productive around 11pm, till I fall asleep.

</comment><comment><USER12> It's very pity, but I am the most productive at night.

</comment><comment><USER13> Right before a deadline.

</comment><comment><USER14> early morning. i get maximum work done between 6am-10am.

</comment><comment><USER15> strange you ask, but i guess just like most will admit here, productivity is at peak for me in the cold hours of the night. It's like darkness brings with it some aura of heightened awareness and gravitation to creative work - <USER2> at least.</comment>


Apple has a porn problem, and it's about to get worse - <AUTHOR> http://www.theverge.com/2013/1/27/3922500/apple-has-a-porn-problem-and-its-about-to-get-worse <comment><USER2> Why is Apple so afraid of pornography, anyway? I could understand wanting to avoid bad publicity in the early days of the app store; but now there's a competing platform overflowing with porn apps (at least I'm assuming that's the case with Android) and nobody in the media seems to complain about it, so maybe their fears were overblown.

Or should we assume that the same media that are completely uninterested in porn apps on Android would drum up a moral panic as soon as they could put "Apple" in the headlines instead? (Well, yes, obviously. But still.)

<comment><USER3> It was something Steve Jobs was vehemently against. Although Jobs asked his heirs never to ask the question, "What would Steve do?", his heirs seems to have bought the no-porn policy sufficiently to be able to enforce it on their own.</comment></comment>


RockMelt Unveils a Web Browser for the Facebook Era - <AUTHOR> http://www.nytimes.com/2010/11/08/technology/08browser.html?src=twt&twt=nytimestech <comment><USER2> So, uh, what component of this browser isn't already addressed in a Firefox plug-in? I doubt it has things like performance increases that would make me choose it over, say, Chrome when I need to go faster than FF.

If its intended audience is less tech-savvy folks, I think they'll have a hard time getting them to even try something that's not IE.

</comment><comment><USER3> This is different than Flock (which was a failure) how?

<comment><USER4> To be pithy — Flock was for nerds (Del.icio.us users); RockMelt is for people (Facebook users).

Not convinced they'll catch on, but at least their target market is bigger, no?

<comment><USER3> Neither is a particularly good idea. People find the current tools perfectly adequate, and as 3/4 of them tell me "I use the big E" or "the red fox" when asking what browser they're using, I doubt this is going to gain much traction.

</comment></comment></comment><comment><USER5> almost as underwhelming as what it turns out kiha is doing</comment>