UberEats lost $3.36 per order and would continue do so for next5 years - <AUTHOR> https://themarkup.org/coronavirus/2020/05/27/during-the-pandemic-grubhub-should-be-thriving-its-not <comment><USER2> This submission broke the site guidelines by using the title to editorialize. Please don't do that.

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

[https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...](https://hn.algolia.com/?dateRange=all&page=0&prefix=false&query=by%3Adang%20%22level%20playing%20field%22&sort=byDate&type=comment).

<comment><USER3> Also, the title isn't even factually correct. The sentence from the article is "In August 2019, analysts from the investment firm Cowen estimated that Uber Eats was losing $3.36 on every order and would continue to lose money on every order for the next five years". It's an estimation from a third-party, not official numbers.

</comment></comment><comment><USER4> UberEats is a real head-scratcher as almost all of the key players, from my perspective, have expressed dissatisfaction to some extent:

1\. Restaurants as UberEats charges a fee often greater than the restaurant's own profitability

2\. Restaurants as there is a real fear that Uber is gathering data for customer tastes/habits to then give priority to CloudKitchens™ or some other variant on commissary kitchen/virtual restaurants

3\. Customers who are shocked by the fully-loaded cost (menu, fee, delivery, tip)

4\. Drivers as they barely earn a living wage and put considerable wear and tear on their vehicles

5\. Potential investors due to heavy losses generated by subsidizing this entire operation

6\. White collar Employees as they are baited/strung along with generous RSU grants to then be overworked at a pace which would make a full vesting impossible

This is really strange because the Indian Dabbawala[0] industry has been operating continuously for 100+ years and one would think that across-the- board PPP/COL adjustments would allow for similar sustainability.

Is there any other industry where almost 100% of everyone involved is currently miserable or are at risk of being disappointed by long-run results?

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

<comment><USER5> Dabbawala isn't a fair comparison.

\- The person making the food in the case of Dabbawala, is usually someone's wife. That's basically unpaid labor. Its not fair for the wife, but that's a different discussion, staying on topic.

\- Delivery routes are pre-determined so routes can be planned efficiently.

\- There's established routines such as the Dabbawala arriving around the same time to pick up food.

\- The dabbawalas usually use trains and bicycles. So they don't pay for the cost of a car, fuel, insurance and maintenance.

\- Dabbawalas, AFAIK, only exist in Mumbai, which has very high population density and enough economies of scale to sustain the business.

\- Dabbawalas don't have a middle man tech company which pays expensive software engineers, and tech executives.

So these factors make dabbawalas profitable while food delivery services don't make a profit.

We recently started calling restaurants and asking if they have in-house delivery, and avoid UberEats/Doordash/OtherDeliveryService. The other day we ordered Thai food, and the owner of the restaurant delivered the food personally and she was truly grateful that we called them instead of ordering online.

This made me wonder, what if restaurants in a city formed Co-op, and started a food delivery service ?

\- Multiple co-ops across different cities could form a LLC and hire Software engineers to build an App & maintain backend services.

\- The same app would work across many cities

\- Each co-op is responsible for hiring its own delivery drivers in the city.

This would eliminate a profit-seeking middle man, and keep costs low. I sense that there would be many obstacles, but I think its still possible, and potentially be even better for the consumer and the restaurants.

<comment><USER6> That's why the standard comparison in the US would be something like Domino's Pizza, which makes money on delivery while being cheap. I think the answer is somewhere along the lines of route/logistic efficiency.

</comment></comment></comment><comment><USER7> > "Bottom line is that you need to pay someone enough money to drive to the > restaurant, pick up food and drive it to a diner. . . ," the company wrote. > "At some point, delivery drones and robots may reduce the cost of > fulfillment, but it will be a long time before the capital costs and ongoing > operating expenses are less than the cost of paying someone for 30-45 > minutes of their time."

Key point here. Even if you are expecting that these drivers are making minimum wage and your operating costs are zero and they have to maintain their bikes/vehicles out of their own pocket, that's still 7.50-11.25$ per order. Which is not something people would be willing to pay for a 20-30$ food order. Hell, I'd say even for a 100$ order people would balk at because they're used to it being free.

We are approaching a reckoning as a society where we need to understand the "true cost" of our choices.

I think the only way you can make door-to-door food delivery financially viable is with A) delivery drones, and B) massive centralized kitchens.

<comment><USER8> >We are approaching a reckoning as a society where we need to understand the "true cost" of our choices.

the much scarier question is why investors apparently don't understand this rather simple fact and keep pumping ungodly sums of money into these ventures

says a lot about the level of general innovation in our society

<comment><USER9> If the move to the centralized kitchens and turn burgers into a commodity product, then I can see Uber being highly profitable. Costs can fall.

<comment><USER10> My primary question, as always with Uber, is with ridiculously easy switching costs, and almost no lock-in, why will Uber be the one that benefits when the profit making $EPOCH happens?

Why wouldnt another well capitalized business that hasn't lost tens of billions of dollars not be able to do better, since for $EPOCH + x years, that other business can actually afford to lose dollars while Uber needs to maintain its profit margin to recover the billions it lost in the pre $EPOCH era.

<comment><USER10> But how would they ever have the most content? There isn't a single restaurant that is not being paid millions by Uber that is specific to Uber. Nearly every cab driver will also drive for Lyft, Via, etc.

Additionally, Google actually competes and wins on content. It's rare that Google offers a worse search result than any of its competitors. However, my food tastes just as good if ordered through Uber Eats or Grubhub or through the restaurant's own website, and my taxi service is likely gonna be the same whether I use Lyft or Uber.

Finally, unlike Google, Uber is actually renting its location from its competitors. Apple and Google could sign deals with Lyft/Seamless to make them the default provider in Maps, Google search, Apple Search or an Apple Restaurants app.

</comment></comment></comment></comment></comment><comment><USER11> >unworkable business model

That's not the right conclusion. The model is fine - you just jack up the price by 5 bucks and you're done. Lose some customers, but remainder is likely break even.

That -3.36 is a result of VC money pushing to companies to go head to head in a race to the bottom that isn't capped to zero. That simple fact distorts everything.

It's _NOT_ a problem with the model of sticking a burger on a bicycle. Look at the bike couriers in NYC - physically this can work and there are probably a fair number of people willing to pay +5.

<comment><USER12> I've said this before but I really don't see any reason whatsoever why UberEats has to be a nationwide, or heck, even a statewide thing.

This market can benefit a great deal from local players who serve just one or a handful of cities. Keep the tech simple to keep costs low. Don't need to invest in any $250k/year data scientists since you won't have a great deal of data to work with anyway (given the small scale).

Lower costs means you can give restaurants and drivers a bigger cut as well.

Most people who will use your app will be local residents. They don't need an app that can help them order in 500 cities across the world - they need an app that can help them order in _just_ their city.

<comment><USER13> Local services like that have existed for decades. They usually have poor websites or even phone ordering, often don't have an app, and the payment methods can be behind the times. But they have always worked fine. The new wave of VC-funded services are trying to grab away the market with both much better UX and subsidizing the deliveries. It's just that no one seems to have a viable plan to exit that phase and be profitable. Meanwhile the traditional services are being edged out of the market. I don't know how this doesn't trip up more fair competition laws because of that.

<comment><USER12> We've come to a point where the tech and UX has been commoditized enough that putting together a functional app with rock solid payment infrastructure isn't technically challenging.

VC money might have pushed smaller players out of the market, but I suspect they might make a comeback soon enough

<comment><USER13> I've seen both cab drivers and these delivery services struggle quite a bit with that, so I'm not as optimistic.

</comment></comment></comment></comment></comment><comment><USER14> The thesis that you can grab market share and then use it to make profits doesn't work in this case.

There's no reason why the customer needs your particular delivery service. Even in a last-man-standing scenario, that last service is competing with a note delivered with every meal that says "please order direct".

I looked into starting a restuarant and it made no sense to me to pay 30% of the meal price to a third party. The breakdown I got from my friend who runs a sushi delivery service in central London is roughly 25% fish, 25% rent / utilities, 30-40% labor. And that's when things are going well, you die if the chefs waste a few % more fish, or if a few people less a day come to order your food. So there's no space for a 30% cut.

Why anyone does it, I'm not sure. Perhaps it is to do with maintaining market share, or making sure your ingredients are used. Of course it's also true that the fish is the only part of that budget that is roughly linear with the number of orders, so maybe the restaurants also fall into a trap of saying they'll try to boost the 45% remaining with volume.

</comment><comment><USER15> Is part of the problem not reading the mythical man month, and trying to hire your way out of problems that don't work that way. I honestly don't get why there would be more than around 25-30 software developers working for Uber, generally speaking. I mean other resources around them, sure...

Many companies will be stuck needing things done, hire teams and teams of new developers and things will only fall farther behind as a result.

Instead of more designers, ux, management, leadership, review, marketing ahead of development so a clear experience is defined for a given project, they try to divide into more developer teams each bottle-necked more than if there were just fewer dev teams.

Meanwhile, so much money is spent trying to get the smallest uplift in efficiencies when the problems tend to be systematic.

\---

I mean to exclude certain things like self-driving cars that should be a separate sub-company.

Also, a bit off... since a team of 4-5 developer per device category or platform interest.

api, web-ui, ios-ui, android-ui, 2x data-services, driver-devices, restaurant- devices, support-apps, 2x admin-apps/reporting (still talking well under 100).

<comment><USER16> Are they still working on self driving cars? That will push the headcount up. For each developer you have project managers, product owners, database admins, techs, ba/technical ba, qa. Not to mention probably a big legal team. Nevermind marketing / ui/ux guys or guys doing reporting or people internal tools.

<comment><USER15> imo, self-driving cars should probably be a separate company owned by the parent... and likely is, and doesn't even apply to the thousands of developers alone they are stafing.

And for each developer there is probably 1:1 for other staff... in my experience for a team of 4 devs, you usually get 1/2 time for a PM, 1/2 time for an owner, a QA, 1/3-1/4 dba and a BA and maybe 1/4 time of a designer.

The primary application could probably do very well with 3-5 dedicated teams to portions of the application with less general conflict and bottlenecking... The support staff would need to scale to meet the larger demands though.

Given their funding, even top-tier engineers at $250-300k (Northern California) base would still be less expensive than hundreds or thousands of developers. Putting the self-driving car research into a separate company.

The site is not _THAT_ complex, and they are, or should be leveraging a number of existing tools. They probably have a byzantine codebase that takes days to make what should be a 15 minute change at this point because of the shear numbers.

</comment></comment></comment><comment><USER17> It doesn't work because the delivery driver isn't delivering multiple orders at once.

<comment><USER18> If that's the case, then everything makes sense to me now, except why they would do that.

<comment><USER19> Optimizing for rapidly growing the customer base (both restaurants and diners) over short term profitability.

It's understandable, if a terrible actual plan. I guess they feel they have to grow fast enough that people don't just ignore them and order directly like we used to and probably will again soon.

Some restaurants won't do delivery anymore, just like it was until recently, and if they want to get into it then the smart people with actual local experience can decide if it makes sense or not.

</comment></comment></comment><comment><USER20> How much of the overall investment was done in the hopes that some level of autonomy would turn all these minuses into pluses within a couple years? I get investing in a loser if there's key enabling tech like this "in the pipeline" but it sounds like even then the math is a bit backward.

Quote from the article: > "At some point, delivery drones and robots may reduce the cost of fulfillment, but it will be a long time before the capital costs and ongoing operating expenses are less than the cost of paying someone for 30-45 minutes of their time."

</comment><comment><USER21> It's always great seeing tons of HN commenters never really realising the potential completely valid reasons a VC would fund a business like this. It feels in part fueled by the media and general anti-VC thing that's going on.

</comment><comment><USER22> Deliveries could be more efficient if kitchens were centralized. It is inefficient to pick from multiple locations.

Maybe you could just have larger kitchens, preparing different types of food under different brands.

</comment><comment><USER9> I'm really surprised that UberEats doesn't try and pull a cruise line type thing, where they have a massive central kitchen and just churn out vast quantities fairly standard food.

<comment><USER12> Cruise line customers generally don't have hundreds of nearby restaurants to choose from.

</comment></comment><comment><USER23> SliceLine did it better

<comment><USER24> sick reference

</comment></comment><comment><USER25> I couldn't tell from the article, but is the 3.36 loss on unit economics, or the loss of the company as a whole per order?

</comment><comment><USER26> I'm incredibly sad that the era of VCs wildly subsidizing my millenial lifestyle is coming to a close.

</comment><comment><USER27> They will make it up on volume.

</comment><comment><USER28> Capitalism evolved into socialism. The free market started subsidizing meels- on-wheels.

<comment><USER29> Subsidized for who though? It's not clear that the consumers, the restaurants or the Drivers are actually getting a good deal here.

<comment><USER30> consumers get it cheaper than it should actually cost? restaurants get to sell more volume during covid, otherwise there's no way they'd have the volume to support staying open, and drivers are getting paid for something that normally wouldn't be a viable thing, I don't think many are leaving better opportunities, otherwise, they wouldn't do it...

<comment><USER29> Have you used any of these apps? Delivery Fee + Servicing Fees + Driver Tip is usually minimum +20% on your order total. How is that cheaper? Restaurants have to pay a flat % to the Apps and this usually crushes their profit even with volume. Do we even need to argue that Uber drivers are getting a good deal? Car maintenance + lack of benefits usually leaves them making minimum wage or worse. It's A job but I don't think anyone is saying its a Good one.</comment></comment></comment></comment>


Longhorn Distributed Block Storage for Kubernetes 1.0 General Availability - <AUTHOR> https://rancher.com/blog/2020/longhorn-container-storage <comment><AUTHOR> Was testing it since yesterday on some new bare metal Kubernetes clusters. It looks really great. Congrats to the Rancher team for getting this to GA!</comment>


Ask HN: How do you increase the pagespeed of your site? - <AUTHOR> <comment><USER2> Have you used:

[https://developers.google.com/speed/pagespeed/insights/](https://developers.google.com/speed/pagespeed/insights/)

and followed the guidance?

<comment><AUTHOR> Yes, I am using Pagespeed Insights.

</comment></comment><comment><USER3> I'm using Lighthouse. Not just for Pagespeed. It has also some different analysis result.

Btw, don't forget to analyze other pages of your website.

[https://web.dev/measure/](https://web.dev/measure/)

</comment><comment><USER4> I think the question is a bit wide. It depends on what your page is about. E.g. is it a pure static page, does it use any APIs, etc.

Some general hints:

\- Minimize size

\- Make things as static as possible, because static means cachable

\- Use a CDN

</comment><comment><USER5> put your page in GT metrix or Pingdom. They will give you a whole host of things to do.</comment>


Common Lisp Implementations: A Survey - <AUTHOR> http://common-lisp.net/~dlw/LispSurvey.html

<comment><USER2> That is comprehensive! Good job. I still do about 1/3 of all of my consulting work in Lisp languages, and even though not the subject of Dan's survey, I suspect that Clojure will help keep Lisp popular with developers who are looking for high productivity languages.

</comment><comment><USER3> btw, I'd love to see Paul Graham's book "The ANSI Common Lisp" sold as an e-book.

<comment><USER4> Here is an unofficial "errata", mostly stylistic issues should you get a copy:

[http://www.cs.northwestern.edu/academics/courses/325/reading...](http://www.cs.northwestern.edu/academics/courses/325/readings/graham/graham- notes.html)

ANSI CL was the first book that helped me enjoy Lisp. My previous books were all vintage "AI" books that were dull. However, one quickly grows out the Graham subset of Common Lisp and ends up using the language to its full potential (i.e. with proper iteration, condition system, object system, exceptions, packages and modules.)

<comment><USER3> Nice link, thanks!

Actually, this book is one that I'd like to keep on the (virtual) back burner. But there is no way I store more paper on my shelves. Fortunately, I bought Practical CL before I set this rule :) But how do I thank PG for On Lisp?</comment></comment></comment>


Petition to Google to Open Source Google Reader - <AUTHOR> Please type +1 and your name in the comments. If you work at Google then please talk tell your management to look here. <comment><USER2> Unfortunately and it's sad but don't believe in this for a minute.

</comment><comment><USER3> Oh for crying out loud, just use Feedly already. It's a perfect replacement once you switch to the headline mode. It's even better in some ways I think (the feed search and recommendations).

</comment><comment><USER4> Really the Reader "Web App" - is not that exiting. Cloning it is only a matter of a few days work.

The interesting bit is the 'backend', the crawler and database, ie the servers that supplies the API. But that simply can't be open-sourced, as it too Google centric.

I just used TT-RSS for the backend, and built my own GReader like front end in a matter of ours.

</comment><comment><USER5> My guess is that it uses too much of Google's core infrastructure for them to open source ... so the answer is probably going to be "No" no matter how many people sign.

<comment><USER6> I wanted to type this exactly.

</comment></comment><comment><USER7> Yeah. Maybe they can't open source the underlying APIs on the backend, but the webapp as such, they could do. That will be great.

</comment><comment><USER8> Encouraging to open source _and migrate_ (not neglect and kill) Google Reader is very important.</comment>


AWS RDS: Aurora - <AUTHOR> http://aws.amazon.com/rds/aurora/

<comment><USER2> I am excited about this, although I imagine it would be difficult to migrate away from.

<comment><USER3> Why? It's major feature is full MySQL 5.6 compatibility. If anything this is probably one of the few Amazon AWS exclusive products that has zero lockin - next to options of say, DynamoDB.

But agreed, I'm excited by this. Have had really good experiences with MySQL on RDS so far - the auto-scale of storage and ability to add read replicas with near real time sync is very cool.</comment></comment>


Vote For Your Favourite Ruby/Rails Resources - <AUTHOR> http://micropoll.com/t/KEzMRZFp5t

<comment><USER2> Railscasts?</comment>


Google App Engine Now Streamlines Push, Boosts API Limits And More - <AUTHOR> http://techcrunch.com/2010/12/02/google-app-engine-now-streamlines-push-boosts-api-limits-and-more/ <comment><USER2> Looks like Google reads Hacker News :)

</comment><comment><USER3> More informative link: [http://googleappengine.blogspot.com/2010/12/happy- holidays-f...](http://googleappengine.blogspot.com/2010/12/happy-holidays- from-app-engine-team-140.html)

<comment><USER4> Even more detailed link (release notes): [https://code.google.com/p/googleappengine/wiki/SdkReleaseNot...](https://code.google.com/p/googleappengine/wiki/SdkReleaseNotes)

</comment></comment><comment><USER3> Thank god. Now maybe my TaskQueue jobs for pre-caching Ajax content (for serving to Googlebot) will actually run to completion.

</comment><comment><USER5> The most important features of this version are the removal of those absurd Size and Time limitations of their API.</comment>


Ask HN: How to get a part-time job? - <AUTHOR> <comment><USER2> start full time, than ask your boss. At least down to 4 days/week is often easy that way.

so far the only easy career-friendly option I found.

Maybe freelancing can work, but that's something else all together. Maybe you can find a startup with limited funds.

If you need some encouragement: [https://codewithoutrules.com/2019/05/09/part- time-software-d...](https://codewithoutrules.com/2019/05/09/part-time- software-developer/) (also pushing his 50 bucks book about the topic, but maybe it's even worth it, idk...)

<comment><AUTHOR> Thanks kind stranger!</comment></comment>


Matt Daemon - <AUTHOR> https://pypi.python.org/pypi/mattdaemon

<comment><USER2> Why Python 2.7 only? This looks like it would be Python 3 code if you simply changed

        print str(err)

to:

        print(str(err))

Except, that's a pretty unhelpful thing to print. I believe a much better statement to put there, in Python 2 or 3, would be:

        raise</comment>


Sales Tricks: People Prefer Larger Denominations of the Same Thing - <AUTHOR> http://arstechnica.com/science/news/2011/02/students-think-that-bigger-numbers-must-mean-something.ars

<comment><USER2> I thought this was a pretty well-known phenomenon. When comparing things, I always convert the numbers into the same scale... For most things, I pick a scale I'm comfortable with and convert to that. Months is a good one for long time ranges and work for converting everything from days to years. Pounds for weight, yards (or meters, really) for short distances, miles for long.

And if the things you're comparing are so far different that you can't fit both on the larger scale, do you really need to compare them?

</comment><comment><USER3> Finally! A justification for charging in picodollars.</comment>


More Americans Watched the Total Solar Eclipse Than the Super Bowl - <AUTHOR> http://www.iflscience.com/space/more-americans-watched-the-total-solar-eclipse-than-the-super-bowl/ <comment><USER2> If the Super Bowl had automatically turned on in every television in the nation and only happened like 3 times a century, I'm sure the figures would be more equivalent.</comment>


Effects of Acetaminophen on Risk Taking - <AUTHOR> https://academic.oup.com/scan/advance-article/doi/10.1093/scan/nsaa108/5897711 <comment><USER2> This study only examined immature humans (mean age around 19). It's well established that perception of risk changes with age. Yet this factor isn't mentioned in the study. Many studies use students as subjects for obvious reasons, but few studies take the maturation process into account.</comment>


Genius Used Morse Code to Track Its Lyrics - <AUTHOR> https://www.wsj.com/video/how-genius-used-morse-code-to-track-its-lyrics/88EA4852-4543-4D50-A313-A613FBD00EC0.html <comment><USER2> Very tricky.

<comment><USER3> You could almost say it was genius...

<comment><USER2> Well played.</comment></comment></comment>


PC Builders' Preferences for Intel Skylake versus Haswell Microarchitectures - <AUTHOR> https://blog.parsec.tv/pc-builders-preferences-for-intel-i7-versus-i5-cpus-and-skylake-versus-haswell-microarchitectures-db96b5edc63#.nfioaea4p <comment><AUTHOR> Some data on the most popular Intel CPUs in PcPartPicker builds. No surprise that builders are opting for the i7 CPUs more frequently than their i5 counterparts. The most popular Haswell CPUs were the 4690K and 4790K. Among Skylake CPUs, the most popular were the 6600K and 6700K.</comment>


5-minute SSH proxy setup in a container environment - <AUTHOR> https://dev.to/mastanggt/5-minute-ssh-proxy-setup-in-a-container-environment-32p <comment><USER2> Not familiar with shadowsocks

How is it different/better/worse than using a "normal" ssh tunneled port as a SOCKS proxy?

<comment><AUTHOR> In terms of user interface it's just a SOCKS5 proxy but with a custom encryption protocol.

<comment><USER2> "custom encryption protocol" should give you the heebiejeebies</comment></comment></comment>


Creating distraction-free reading experiences - <AUTHOR> http://azumbrunnen.me/blog/creating-distraction-free-reading-experiences/

<comment><USER2> I might be old and crotchety, but that post is the opposite of a distraction- free reading experience. I count at least 6 fonts, 3 different background colors, 3 text colors, excessive whitespace on the borders, images that break that whitespace, animations, all pictures interrupt the flow of text...

</comment><comment><USER3> I find it ironic that the background of the page keeps changing from light to dark and that the article is interspersed with images including a GIF.

<comment><USER4> The change of background colors is a deliberate design choice. The content is long and the background helps the reader, especially on mobile, to understand in which section he currently is.

It's a presentation in the form of an article. Same content, different medium.

</comment></comment><comment><USER5> How about we stop trying to design experiences and instead just write better?

The reason why you were absorbed into the book had little to do with the way the book was printed and everything to do with the story.</comment>


How WhatsApp Fuels Fake News and Violence in India - <AUTHOR> https://www.wired.com/story/how-whatsapp-fuels-fake-news-and-violence-in-india/ <comment><USER2> When we live in a society, we agree (consciously or not) to live by a set of rules (written or not). We get the benefits and obligations that come with that.

WhatsApp exists in this society, yet it doesn't want to play by its rules saying it would compromise its core values around privacy.

What's to make of this? As much as I'm pro privacy, I feel like any application needs provisions for law enforcement. If you think that will be abused by someone in the system, it should be fixed elsewhere.

I'm trying to break this down to the basics but, as I see it, WhatsApp wants a common denominator for privacy laws in the world but is it willing to invest in lobbying everywhere it operates?

<comment><USER3> There are no universal societal rules prohibiting end-to-end encryption.

<comment><USER4> Cheap, seamless, end-to-end encryption is still a game-changer to the social order. We protected messages before with envelopes and seals and basic ciphers that law enforcement could break if the need arose.

It doesn't mean popular encryption is a bad thing. But it is a new thing, with impacts on the social that we don't understand or know how to compensate for. Like people getting "news" primarily through encrypted chats, creating a dream environment for Macedonian fake news authors who make money by stoking their racism. Who could have anticipated that?</comment></comment></comment>


A wrapper of pandas.DataFrame to support better stock statistics and indicators - <AUTHOR> https://github.com/kaelzhang/stock-pandas <comment><AUTHOR> I extend the pandas.DataFrame indexing with the support of a simple DSL directive.

Hope you guys enjoy that.

For now, it only supports several stock indicators, but it is fully extendable, a bunch of new indicators are on the way.</comment>


A "Wimpy" Dwarf Fossil Galaxy Reveals New Facts About Early Universe - <AUTHOR> http://newsoffice.mit.edu/2014/wimpy-dwarf-fossil-galaxy-reveals-new-facts-about-early-universe-0501

<comment><AUTHOR> The mentioned paper, "Segue 1: An Unevolved Fossil Galaxy from the Early Universe" published in the "Astrophysical Journal" is here:

[http://arxiv.org/pdf/1403.6116](http://arxiv.org/pdf/1403.6116)</comment>


Ask HN: A good Cloud IDE - <AUTHOR> Is anyone using a cloud IDE  for java/ python development? What's your review of it? <comment><USER2> I can't speak for Java/Python development but I do a lot of JavaScript in Cloud9. Its a cloud IDE that got purchased by AWS. Pretty smooth setup and if you're already in AWS already you can take some advantage of existing services that hookup to Cloud9.

<comment><AUTHOR> Are you subscribing to cloud 9 or is it part of your company's toolchain?

</comment></comment><comment><USER3> This might help [https://www.slant.co/topics/713/~best-cloud- ides](https://www.slant.co/topics/713/~best-cloud-ides)

<comment><AUTHOR> I have tried codenvy and codeanywhere. Had lot of trouble get going. Most of the times I see tons of error messages in the js console. Thanks for suggesting me this article.</comment></comment>


Salters Duck - <AUTHOR> http://en.wikipedia.org/wiki/Salter%27s_duck <comment><USER2> Total available wave energy relative to present human energy consumption is minuscule.

Realize: wave energy is solar power twice removed. First solar heating converted to wind energy, then wind to waves. If you can capture the initial solar flux, you're better off. Wind is your second-best option, and where that's locally high, the EROEI (energy returned on energy invested) is quite high.

Marine installations are notoriously high maintenance. Water, salt, corrosion, marine life, snagging, navigations hazards, and other factors, all play a role. Few man-made (or natural) materials survive well, and those which do tend not to play a big role in power generation.

Even tidal energy, with both more available power and greater concentration than wave energy, has at best limited potential. As an example that may be relateable to HN, the energy avaiable from daily fluctuations in the San Francisco Bay, at the Golden Gate. In 2006, EPRI (the Electric Power Research Institute) established that the Golden Gate has a tidal energy potential of 35.5 megawatts of total extractable average energy power (852 MWh/day, 310 GWh/year), of which 15 to 17 GWh might be practically exploitable at costs comparable with current wind and natural gas projects.

The total tidal energy represented at the gate is 237 MW (average). Capturing the entire amount would require blocking the Bay to any and all shipping traffic, or installing locks or other means to allow shipping in and out of the Bay. The total daily energy (5,688 MWh) _is still well below the 18,000 MWh consumed by San Francisco daily),_ though it is a healthy fraction at 32%.

Note that that's the power draw _of San Francisco alone_. Not the greater Bay Area.

Yes, all that water flowing in and out of the bay daily and the "immeasurable energy" it represents? About 1/3 of the City of San Francisco's electricity usage.

 _Human beings use a LOT of energy._

[http://www.sfenvironment.org/article/hydro/tidal- energy](http://www.sfenvironment.org/article/hydro/tidal-energy) [http://oceanenergy.epri.com/attachments/streamenergy/reports...](http://oceanenergy.epri.com/attachments/streamenergy/reports/006_CA_06-10_-06.pdf)

<comment><USER3> What waves and tidal energy represent, though, is something which might be a lot more capital efficient.

Yes you're much closer to the power source using photovoltaics but they're only 20% or so efficient right now commercially. Further, the sun only shines on where I live between 8 and 16 hours a day, depending on the season. The useful average power I can expect to extract on average is about 3-4 hours per day.

Waves, on the other hand, are an excellent store of energy and they persist for a long time. Easily overnight and actually over many days. So if you can reliably produce power from waves for the same capital cost per watt installed, you might get 3x-5x the energy production from the wave plant versus the solar plant. And that's before you take into account the storage necessary for solar!

In other words you might be able to spend 10x on a wave power plant as a solar plant and break even. If it only costs 2-3x as much per watt, well, you're saving money. And the batteries (the ocean) are free.

<comment><USER4> Solar: purchase panel and leave it in an incline for 15 years. If you have net metering you don't need to even think about storage.

Wave: develop massive steel structures in the ocean and transmit power to land with low power density.

It's telling that, given the possibility to pick anywhere to develop wave power (even at the most convenient locations) the tech has barely any projects.

<comment><USER2> At some point _someone_ has to consider storage (or alternative provisioning, or dispatchable load) for solar-backed grid. Even if it's not the homeowner with panels on their own roof.

<comment><USER5> Theoretically with solar panels you could have a round-the-clock, round-the- globe balanced network requiring no storage. It would be a network with the same capacity of panels on each meridian. Of course this is not very practical.

<comment><USER3> Not only not very practical but it would require entirely new transmission technologies: the maximum practical length of a 60Hz transmission line is only a few thousand miles. To go from the bright side to the dark side of the earth is worst-case 12,000 miles so new tech would be needed, or you'd just have to suffer 30% (or more) transmission line loss.

</comment></comment></comment></comment></comment></comment><comment><USER6> I like this concept in particular, because it has no mechanical parts in contact with the water: [https://www.youtube.com/watch?v=gcStpg3i5V8](https://www.youtube.com/watch?v=gcStpg3i5V8)

Edit: It seems however that tidal power is a more interesting research area [1]. I still find it's a neat idea, it also makes awesome noises: [https://www.youtube.com/watch?v=IK65S0sPtsg](https://www.youtube.com/watch?v=IK65S0sPtsg) (loud)

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

</comment><comment><USER7> A friend of mine worked with Prof. Salter. He's an incredibly brilliant, smart and kind scientist. Unfortunately, much of his research was 'blocked' due to someone miscalculating the cost by twice the amount, starving the research field of funding until recently. There are quite a few related spin-outs (e.g. Pelamis Wave, website currently down). Edinburgh also just got a huge wave tank for more experiments ([http://www.bbc.co.uk/news/science- environment-27702506](http://www.bbc.co.uk/news/science- environment-27702506)).

</comment><comment><USER8> That's the problem with cheap oil, like we have now with fracking, it kills all market incentive to develop clean energy. If we're ever going to get serious about climate change we need a dynamic carbon tax that keeps the price of fossil fuels stable and high.

If we had such a carbon tax right now, that kept gas price at the previous price of $4/gallon, it would be a huge windfall that could be used to spend on clean energy incentives as well as low-income energy subsidies.

<comment><USER9> well no, because most renewable energy sources aim to produce electricity. Very little electricity is generated using oil, so the oil price should have little impact on most renewable energy production. The culprits are cheap gas and coal - especially coal, which really should be heavily taxed because of the huge health and environmental impacts from mining and burning coal.

<comment><USER2> A few corrections.

 _Within_ the US, little electrical generation comes from oil (about TK%), but _outside_ the US that level's rather higher -- something I only learned recently myself when trying to rebut the statement that oil _was_ significant in electricity generation elsewhere.

Hrm. Still not _all_ that big. 256 Mtoe per the IEA in 2012, of 6,497 MTOE, about 4% - 6% depending on how you read net global imports / exports. (How does the world import/export to itself?)

[http://www.iea.org/Sankey/index.html](http://www.iea.org/Sankey/index.html)

Though in many parts of the world, electricity comes from gasoline or diesel generators on small scale rather than central generation plants.

There's also the fact that renewable energy _can_ produce liquid or gas fuels via the Sabatier process (resulting in natural gas) or Fischer-Tropsch fuel synthesis (liquids). These aren't used in bulk now, but could be, and represent a possible carbon-neutral gas and liquid hydrocarbon fuel source in future.

</comment></comment></comment><comment><USER10> "DUCK EFFICIENCY on COMPLIANT AXIS" is a great title for a graph. It would make for a pretty amusing piece of art.

[http://i.imgur.com/NR34IOt.jpg](http://i.imgur.com/NR34IOt.jpg)

<comment><USER11> Wasn't it the title of an ELP album from the 1970s?

</comment></comment><comment><USER12> Wave energy is one of those ideas that 100's of clever people have had independently over the years and not a single one has been able to make it work reliably and cost effectively.

We've seen a wide variety of prototypes, some even made it to net power out but absolutely _nothing_ came close to winning the prize. (Though that didn't stop the government from pumping large amounts of subsidy into some of these.)

When you compare 'wind' to 'waves' (or tides, for that matter) the environment is even more hostile, the power transportation problem more acute and the engineering challenges incredibly more formidable and the maintenance headaches harder still.

Having mostly stationary waterborne structures is hard enough and commands skills that are rare and very expensive (think oilrigs). Now change that to dynamic structures which drive generators, add in storms, salt water and interference with shipping and you're looking at a very expensive and complex mixture. It will take extremely deep pockets to pull this off successfully, with the inbuilt assumption of a number of false starts and resulting re- engineering.

Elon Musk will likely walk on Mars (or die on impact) before we will see widespread adoption of tidal energy for electricity generation on Earth. Which is a pity, because it seems such a good idea.

<comment><USER13> This one is in use in Scotland: [http://en.m.wikipedia.org/wiki/Islay_LIMPET](http://en.m.wikipedia.org/wiki/Islay_LIMPET)

<comment><USER12> 500 KW (now derated to 250KW), it's neat but that's piddly little bits of power for an installation that size. A single present day wind turbine will produce up to 3 MW continuously rather than pulsed.

Pity I didn't know about it when I toured Scotland a couple of years ago looking at their renewable energy installations.

This one was by far the most impressive:

[http://pics.camarades.com/v/jacques/trips/scotland08/dscf158...](http://pics.camarades.com/v/jacques/trips/scotland08/dscf1585.jpg.html)

</comment></comment></comment><comment><USER9> [http://en.wikipedia.org/wiki/Pelamis_Wave_Energy_Converter](http://en.wikipedia.org/wiki/Pelamis_Wave_Energy_Converter)

The Pelamis, based on technology evolved from the Salters Duck at the Edinburgh labs, was installed in pilot installations for a few years through the company has sadly since gone bankrupt

</comment><comment><USER14> I couldn't find any pictures or videos of how this works.

<comment><USER15> [http://www.technologystudent.com/energy1/tidal7.htm](http://www.technologystudent.com/energy1/tidal7.htm)

</comment></comment><comment><USER16> Interesting overview of Edinburgh duck R&D. [https://www.youtube.com/watch?v=_bdeNuRF- yE](https://www.youtube.com/watch?v=_bdeNuRF-yE)

</comment><comment><USER17> A lot of wave and tidal motors were built along the California coast in the late 1800s and early 1900s. It's an interesting history. Cheap fossil power made them uneconomical, though.

[http://bldgblog.blogspot.com/2009/05/wave-motors-of- californ...](http://bldgblog.blogspot.com/2009/05/wave-motors-of- california.html)

[http://www.outsidelands.org/wave-tidal.php](http://www.outsidelands.org/wave- tidal.php)

</comment><comment><USER18> Still never understood why they don't concentrate on using areas where currents are well known, for Europe that would be the Straight of Gibraltar. There is energy in the outflow from the Med into the Atlantic at the bottom layers, surely capturing energy like that is not as difficult as surviving the forces waves put out.

</comment><comment><USER19> I've read another article about a similar device in Brasil:

[http://m.youtube.com/watch?v=GA_UgVm9bvU](http://m.youtube.com/watch?v=GA_UgVm9bvU)

</comment><comment><USER20> Tidal generators are in production. There's a pilot program installing them in NY harbor. They're fully submerged and I don't think they're ducks.

<comment><USER21> this is not about tidal power

</comment></comment><comment><USER22> Does it generate DC or AC? I think there are losses if you want to transport and connect the power generated up to the grid

<comment><USER12> It generates pulses of AC power, but that can be overcome by feeding those pulses into a flywheel or superconductor based short-term storage system.

</comment></comment><comment><AUTHOR> What's more interesting is that Salter was Studying AI at the university of Edinburgh

</comment><comment><USER23> It sounds like a brilliant idea, how come these things aren't all over the North sea?

<comment><USER24> Because waves don't transfer that much energy. There's a reason why ships had sails, even though winds were highly variable and waves somewhat less so. Also, maintenance on anything you put in the ocean tends to be high.</comment></comment>


Linux Commands In Structured Order with Detailed Reference  - <AUTHOR> http://linoxide.com/guide/linux-command-shelf.html <comment><USER2> Nice and useful list if a little simple.

However, why the heck does clicking in the index scroll the page using javascript instead of using anchor tags?</comment>


Student Loans, Gateway Drug To Debt Slavery - <AUTHOR> http://consumerist.com/2010/09/student-loans-gateway-drug-to-debt-slavery.html

<comment><USER2> The bubble - as some like to call it - in education comes from declining government support per student. At least at state institutions. We are now in a system where people take out large loans for the hope of attaining a higher paying job. When you lose this lottery you pay real big. There are long term negative consequences to this.

As long as society at large is unwilling to properly fund education then we'll all lose in the long run. The 'ever person for themself' makes us all losers in the long run.</comment>


Interpretable Machine Learning: A Guide for Making Black Box Models Explainable - <AUTHOR> https://christophm.github.io/interpretable-ml-book/ <comment><USER2> I don't even think simple linear models are actually explainable. They just seem to be. Eg, try this in R:

      set.seed(12345)
      treatment = c(rep(1, 4), rep(0, 4))
      gender1   = rep(c(1, 0), 4)
      gender2   = rep(c(0, 1), 4)
      result    = rnorm(8)

      summary(lm(result ~ treatment*gender1))
      summary(lm(result ~ treatment*gender2))

Your average user will think coefficient for treatment tells you something like "the effect of the treatment on the result in this population when controlling for gender". I get a treatment effect of 1.17 in the first case, but -0.38 in the second case, just by switching whether male = 0 and female = 1 or vice versa.

<comment><USER3> Of course not. Your contrasts aren't centered on zero. Here's the right way to approach it:

      set.seed(12345)
      treatment = c(rep(0.5, 4), rep(-0.5, 4))
      gender1   = rep(c(0.5, -0.5), 4)
      gender2   = rep(c(-0.5, 0.5), 4)
      result    = rnorm(8)

      summary(lm(result ~ treatment*gender1))
      summary(lm(result ~ treatment*gender2))

Now the two are identical except for the sign of the gender coefficient.

<comment><USER2> So what is the intuitive explanation here? You can choose to code it 1/0 0/1 or -.5/.5, or -643/643 and the result you care about is different.

<comment><USER3> The intuitive explanation is that you really are writing down a model of the form

      result = a + b*treatment + c*gender

Let's ignore the interaction term for the sake of simplicity. It doesn't change anything in what follows. The two operations I think about for interpreting this are:

1\. What equation results when I fix a particular value of a factor? This is equivalent to taking a subset of the population I'm studying.

2\. What equation results when I average over a factor? This is equivalent to removing a dependent variable from my model.

If I remove the dependent variable gender and look at the equation when I fix the two values of treatment, what do I want my model to look like? I think that

      result = a

for no treatment and

      result = a + b

for treatment is the easiest to interpret. Then a is the baseline without intervention, and b is the effect of the treatment. To get those, I make no treatment = 0 and treatment = 1. If I made no treatment = -0.5 and treatment = 0.5, I would get

      result = a - 0.5*b

for no treatment and

      result = a + 0.5*b

for treatment. I've messed up my interpretation of the parameters. But what contrast do I need for gender to get this? If I use male = 0 and female = 1, then when I average over the whole population (assuming that it's balanced male/female), I get

      result = a + 0.5*c

for the baseline of no treatment, averaged across the population and

      result = a + b + 0.5*c

for treatment. a and c are now mixed, messing up what I can interpret off the parameters. If I want to keep the baseline a an average over gender, then I need my levels for gender to sum to zero. But what happens if I use, as you suggest, -643 and 643 for male and female? Let's fix treatment to zero and look at the equation for the result for male and for female. For male:

      result = a - 643*c

and for female:

      result = a + 643*c

All we've ended up doing is scaling the parameter that we interpret as the difference between male and female response by 643. That would be a lot easier to use if the parameter actually measured the difference between male and female directly instead, so let's set it up so that the difference between the two levels is 1, or use -0.5 and 0.5.

<comment><USER2> >"Let's ignore the interaction term for the sake of simplicity. It doesn't change anything in what follows."

It changes the estimates if you don't assume the interaction coefficient = 0, how can you just ignore it? Actually, not assuming zero interaction changes everything: [https://en.wikipedia.org/wiki/Principle_of_marginality](https://en.wikipedia.org/wiki/Principle_of_marginality)

<comment><USER3> For the purpose of getting intuition about setting levels, it doesn't change anything. Obviously for what you actually fit, it matters.</comment></comment></comment></comment></comment></comment>


Ask HN: how can the online dating industry be disrupted? - <AUTHOR>

Disruptive online dating startups are on PG's list of things he would fund.
What are some general themes and idea for how to do this?
I'll post my own ideas as a comment in a sec. <comment><AUTHOR> Here are my ideas:

[http://ideashower.posterous.com/idea-smartphone-video- speed-...](http://ideashower.posterous.com/idea-smartphone-video-speed-dating)

[http://ideashower.posterous.com/idea-dating-site-staff-of- fe...](http://ideashower.posterous.com/idea-dating-site-staff-of-female- helpers)

[http://ideashower.posterous.com/idea-dating-with-with- testim...](http://ideashower.posterous.com/idea-dating-with-with-testimonials- from-frien)

[http://ideashower.posterous.com/idea-dating-site-with- voice-...](http://ideashower.posterous.com/idea-dating-site-with-voice-mail- instead-of-m)

<http://ideashower.posterous.com/ide-date-blocket> (translation: inbox-less insta-signup dating site)

[http://ideashower.posterous.com/ide-kontaktannonser-med- ultr...](http://ideashower.posterous.com/ide-kontaktannonser-med-ultrakort- tid) (translation: short dating site profiles with short duration - maybe a bit like Twitter)

<http://ideashower.posterous.com/ide-barcode-dating-73473> (translation: dating via stickers with those QR codes - or the user could just scribble a unique ID with a crayon on the toilet stall walls)

[http://ideashower.posterous.com/ide-create-your-own- dating-s...](http://ideashower.posterous.com/ide-create-your-own-dating-site)

[http://ideashower.posterous.com/idea-dating-site-with- gamifi...](http://ideashower.posterous.com/idea-dating-site-with-gamification)

[http://ideashower.posterous.com/idea-walk-in-my-shoes- dating...](http://ideashower.posterous.com/idea-walk-in-my-shoes-dating-site)

<http://ideashower.posterous.com/idea-lunch-meetups> (not dating, but similar)

[http://ideashower.posterous.com/idea-dating-site-that- gets-r...](http://ideashower.posterous.com/idea-dating-site-that-gets- reluctant-female-s)

<http://ideashower.posterous.com/idea-misc-dating-site-ideas>

[http://ideashower.posterous.com/idea-systemic-general- proble...](http://ideashower.posterous.com/idea-systemic-general-problems- with-dating-si)

</comment><comment><USER2> Here is my blog post on same topic -

[http://blog.anujkumar.com/post/10513302814/online-dating- pas...](http://blog.anujkumar.com/post/10513302814/online-dating-past-present- and-future)

My idea is to not make a "dating site" but make a "hangout" site that focus on real world hangouts with real friends and fof. Recreate the atmosphere of college online.

<comment><AUTHOR> Interesting.

Here's a random thought: a lot of people meet through World of Warcraft. Can that kind of experience be replicated and tailored towards dating?

<comment><USER2> I'm not much into role playing games so I don't have any idea about WOW.

I think the best approach is to focus online dating around these concepts :

1\. Location based - same city. I personally feel long distance relationships suck.

2\. In known social network - friends, friends of friends, colleagues, etc. much like google+, facebook. Friends of friends are good prospects to find potential dates you can trust(your friends know them). This will solve "trust" issue. Also, there will be some kind of social pressure to behave in a good way.

3\. Things to do together(online or offline). Just match making isn't enough. Give them ideas and things to do together:

a) Online ideas - play games, chat, watch movie together(+video chat), etc.

b) offline ideas - Visit places (restaurants, amusement park, sea beach etc), attend events, do activities(cycling, walking, swimming, dancing etc). How about group outings (his friends and her friends) to get things started?</comment></comment></comment>


Twitter is finally giving our chronological timelines back - <AUTHOR> https://thenextweb.com/apps/2018/11/01/twitter-is-finally-giving-our-chronological-timelines-back/ <comment><USER2> I've seen a number of stories that seem to get this wrong. It's not a new feature, really. You've been able to toggle off "Show the best Tweets first" in the "Content" section of the settings of both the web app and mobile clients for a while now. Turning it off restores the chronological timeline.

This UI experiment seems like it's just giving a one-tap toggle on the header of your Home timeline, rather than making you go into your profile's settings.</comment>


Ask HN: Online Training for Continuous Delivery, End to End? - <AUTHOR>

Does anyone know of a place with a video walkthrough of the process of setting up a one button deploy webapp from start to finish?
Something that shows how that person/team glues together all the major tools/services.  It doesn't matter what web framework/language, really.  Just something that shows how to build, test, stage, deploy, and monitor an internet facing webapp.
For example, how to chain together and really use services like github, new relic, loggly, cloud passage, chef, puppet, etc on ec2 or heroku.
I've got a lot of the pieces, but I'd like to see how someone puts theirs together.  It might not be 100% exact to my situation, I get that.  It's not the tools so much as demonstrating the power of the finished/integrated capability.
I want to answer the question of: "What does a leading edge CI/CD stack feel like?"
I keep hearing "you have to dive in" and " it'll take time to figure out what works" and "it's a process, not a destination."  All valid points.  But I'd like to dive in while following a known-good path and start improving from there.  And I'm willing to pay to save a lot of time/miscues while avoiding bad habits. <comment><USER2> Not exactly what you are looking for, but we are trying to incorporate this issue into our course structure at www.codeyelp.com (not released yet). Even if you do not want to enrol, this type of end-to-end deployment video should be released soon.

<comment><AUTHOR> Ill keep my eye on your site for that. Thanks.</comment></comment>


Learn regular expressions in about 55 minutes - <AUTHOR> http://qntm.org/files/re/re.html <comment><USER2> You will learn _about_ regular expressions in 55 minutes. To learn _how to use_ regular expressions, in as long as it might take you, it might be better to:

Read the wikipedia page which has a great description of what regular expressions are and why you would use them: [https://en.wikipedia.org/wiki/Regular_expression](https://en.wikipedia.org/wiki/Regular_expression)

Read the JS docs: [https://developer.mozilla.org/en- US/docs/Web/JavaScript/Guid...](https://developer.mozilla.org/en- US/docs/Web/JavaScript/Guide/Regular_Expressions?redirectlocale=en- US&redirectslug=JavaScript%2FGuide%2FRegular_Expressions)

Test your regexes: [http://regexpal.com/](http://regexpal.com/)

Visualize your regexes: [http://www.regexper.com/](http://www.regexper.com/)

Try some challenges: [http://callumacrae.github.io/regex- tuesday/](http://callumacrae.github.io/regex-tuesday/)

And remember, writing regular expressions can be very difficult, reasoning about your regular expressions can be even more so, defining your problem can be the most difficult of all. Think before you regex.

<comment><USER3> The most difficult part of regex isn't defining the problem. I'd say that one's easy. The hardest part is figuring out your regex months or years after you've written it!

<comment><USER4> extended regexes with comments (aka /x) should be the default and enforced behaviour in all newly designed languages.

Sadly, the only one that does is perl6.

<comment><USER5> Python has them:

        a = re.compile(r"""\d +  # the integral part
                           \.    # the decimal point
                           \d *  # some fractional digits""", re.X)

<comment><USER6> Coffeescript has similar functionality. From the Coffeescript docs:

        OPERATOR = /// ^ (
          ?: [-=]>             # function
           | [-+*/%<>&|^!?=]=  # compound assign / compare
           | >>>=?             # zero-fill right shift
           | ([-+:])\1         # doubles
           | ([&|<>])\2=?      # logic / shift
           | \?\.              # soak access
           | \.{2,3}           # range or splat
        ) ///

When turned into Javascript it becomes:

        var OPERATOR;

        OPERATOR = /^(?:[-=]>|[-+*\/%<>&|^!?=]=|>>>=?|([-+:])\1|([&|<>])\2=?|\?\.|\.{2,3})/;

</comment></comment></comment></comment></comment><comment><USER7> The tutorial I learned regular expressions from, which is longer but more detailed than this one, was [http://www.regular- expressions.info/](http://www.regular-expressions.info/). It's free, thorough and well-organized. Its only flaw is that its section on support in various languages is out of date. It was written to sell a Windows-only regex tool, but it's very non-pushy with the advertisements.

You can see a list of online regular expression testers for various languages at the Stack Overflow "regex" tag wiki, in the "Online sandboxes" section: [http://stackoverflow.com/tags/regex/info](http://stackoverflow.com/tags/regex/info). For JavaScript regexes, [http://regexpal.com/](http://regexpal.com/) is easy to use.

<comment><USER8> Another excellent resource, which I believe was highlighted a few years ago here on HN: [http://regexone.com/](http://regexone.com/)

</comment></comment><comment><USER9> Alternative titles :

"How to make your code unreadable in 55 minutes"

"How to make your code hard to debug in 55 minutes"

"How to introduce bugs by copying a regex that you don't understand and neither did the author"

<comment><USER10> That's a stupid reply. Regular expressions are very useful.

<comment><USER11> Regular expressions are useful, but on a much smaller set of problems than people typically use them for.

For example Chrome's script skipper in the debug tools completely unnecessarily uses regexes rather than a simple list of 'contains'.

It's definitely one of the worst "everything's a nail" hammers a lot of programmers wield. And quite often they've been holding it upside down for years without even realizing it.

<comment><USER12> Another situation where regexes are possibly abused - syntax highlighting. Yes, there are a lot of languages where you can sanely highlight /most/ code with regexes, but there's a non-zero number where you need a little more context, such as that provided by an AST (which would also help with autocompletion anyway if the highlighting is being done in the context of an editor).

</comment></comment></comment></comment><comment><USER13> For the author: I've learned regex for a while, for years, I always come back to them and I'm always annoyed to forget about them if I don't use them for a long time.

I use mostly cheat sheets now,

but still, your tutorial was the best I ever read and I actually read it. It reads better than a "learnXinYminutes.com" and I actually learned some new stuff.

Notes:

validating email adresses: most MVC have a function that does that. I know that PHP has that natively as well.

</comment><comment><USER14> Handy. This does gloss over some of the notable differences between implementations (not everything has non-greedy matches or identical {m,n} or {m,} syntax), but it's still by far the best tutorial introduction I've seen for regular expressions.

<comment><USER15> Would you mind linking the best tutorial introduction that you've seen for regular expressions?

I found the parent link incredibly useful because it listed common, useful expressions and examples of what you do (or don't) get when you use them.

I don't think of it as a tutorial at all since it wasn't really -- more of a reference or a quick guide.

<comment><USER14> In my comment above, I said _this_ is the best tutorial introduction I've seen, even with its few limitations regarding differences between regex implementations.

<comment><USER15> Whoops! Sorry for misreading that.

I completely misread "Handy" as "Hardly" and then saw "Hardly. This does gloss over some of the notable differences . . ." which changed the entire tone of your comment for me.

My bad.

</comment></comment></comment></comment><comment><USER16> > _\w means the same as [0-9A-Za-z_]_

I've got news! There are some characters outside ASCII

<comment><USER17> To be fair, this depends on the implementation. Java, JavaScript and PCRE will only match ascii characters.

</comment></comment><comment><USER18> I found [http://regexcrossword.com/](http://regexcrossword.com/) to be a good learning tool.

Here's one if you really want to test your skills: [http://i.imgur.com/qLh2gcK.jpg](http://i.imgur.com/qLh2gcK.jpg)

<comment><USER19> i'm not sure if this puzzle is meant to be a joke, but it pretty much looks like it.

things like (O|RM|HHM)* which means match anything. who the hell would every write (.)(.)(.) when even capturing those is pointless in a crossword.

meh, i say.

<comment><USER20> I'm not entirely sure what you are saying, but I actually find this puzzle quite interesting.

(O|RM|HHM)* doesn't match "anything", but rather "nothing" or something quite specific. [0]

There are multiple rows in the puzzle where things _can_ match anything, but they are pretty fast limited by the opposing row/column.

[0]: [http://www.regexper.com/#%28O|RM|HHM%29*](http://www.regexper.com/#%28O|RM|HHM%29*)

<comment><USER19> yeah sorry, wrote that in a hurry. i meant, if it can match nothing and still be valid, what's the point? you may as well write `.*`

</comment></comment></comment></comment><comment><USER21> The time I finally _really_ learned regex was the time I _really_ needed them for a project that was beyond something I could stack overflow. I think having some problem in front of oneself, and testing over a ton of input data is a great way to learn.

</comment><comment><USER22> I find regular expressions intensely annoying. I come across situations where they are a perfect fit, but, as I've never got around to learning the syntax I spend ages looking for a perfect, or sometimes not so perfect, answer on SO that gives me the arrangement. More often than not, in order to tweak the answer to make it fit I find myself in the position of having to learn the syntax in order to do so. Catch 22.

It seems there are no shortcuts and you can't practice cut and paste.

Note to self. Learn the syntax.

</comment><comment><USER23> I had to learn RegEx because of Google Analytics. The folks from LunaMetrics wrote a handy guide - [http://www.lunametrics.com/regex-book/Regular- Expressions-Go...](http://www.lunametrics.com/regex-book/Regular-Expressions- Google-Analytics.pdf)

It's still just basic RegEx, but if anyone is looking for stuff with more context related to GA, this is the one for you.

</comment><comment><USER24> This is awesome. It would be even awesomer if it came with some practice problems after each section!

<comment><USER25> Yes, you are right. Learning needs interaction with the material.

Any experts here want to set an exercise for each section? We can argue about the _best_ solution in true HN style, and the result will be a good resource.

</comment></comment><comment><USER26> To really know and understand regular expressions, write a regular expression pattern matcher.

</comment><comment><USER27> I have problems with linux and escape characters.

grep '".*\?"' test.txt

"test1" test2 "test3"

matches entire string while article says that ? should force it to match as little as possible. (All "test1", test2 and "test3" are highlighted as red) It works correctly [http://regexpal.com/](http://regexpal.com/). What am I doing wrong?

<comment><USER28> This is when you learn that not all implementations are the same, and realize it's better to read the documentation for your particular implementation.

I'm guessing your grep defaults to POSIX EREs, but always check the manual.

      The behavior of multiple adjacent duplication symbols ( '+', '*', '?', and intervals) produces undefined results.

[http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_...](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html)

</comment></comment><comment><USER29> I don't particularly need a regex course, but I have to say, this site is so nicely designed, so easy for the eye.

A good way to practice regex is to use one of the many online regex tools to validate your understanding. My current favorite is [http://www.gethifi.com/tools/regex#](http://www.gethifi.com/tools/regex#) because it shows the group.

<comment><USER30> That's how I "learned" regex.

[https://developer.mozilla.org/en- US/docs/Web/JavaScript/Guid...](https://developer.mozilla.org/en- US/docs/Web/JavaScript/Guide/Regular_Expressions#Writing_a_Regular_Expression_Pattern) and [https://www.debuggex.com](https://www.debuggex.com) and lots of patience :)

</comment></comment><comment><USER31> RegEx 15 minutes to learn, a lifetime to master.

<comment><USER32> Where mastering hopefully means to just avoid them whenever possible.

</comment></comment><comment><USER33> Why is it that I find it much easier to just build a lexer/parser than I do using regex? Something about my brain, every time I see them I usually do everything in my power to not have to try to understand them.

On the other hand, I've worked with some regex ninjas who appear to just innately get it.

Maybe it's like cilantro, separating us by genetics.

<comment><USER34> Well I think you're in the "good" side of the discussion. Sometimes whenever people learn regular expressions, they try to solve everything with them, but for any kind or medium sized problem or DSLs, writing a custom parser is a better option.

</comment></comment><comment><USER35> I love the summary at the bottom. Concise and to the point... He could have wrote how to learn regex in 55 seconds.

</comment><comment><USER36> I do some online training - I'll refer people over to this for a good refresher/intro to regex. Thanks.

</comment><comment><USER37> A regex monster:

[http://blog.codinghorror.com/regex-use-vs-regex- abuse/](http://blog.codinghorror.com/regex-use-vs-regex-abuse/)

</comment><comment><USER38> That was really concise and well written. I particularly appreciated the clean warnings and subtle grips about the confusing pats of the syntax.

</comment><comment><USER39> Might be nice to include the %r{} style in the "Excessive backslash syndrome" section.

</comment><comment><USER40> The most important things to learn about regex are greed and boundaries.

Nobody cares about 'cat' for that you use a basic replace function in your preferred language, so when you learn about masks and patterns you need to understand when to start and when to stop.

Finding everything between quotes ".*" is not gonna give you what you expect.

</comment><comment><USER41> I'm still waiting for "Reg-ex considered harmful".

<comment><USER42> no need to wait! [http://regex.info/blog/2006-09-15/247](http://regex.info/blog/2006-09-15/247)

<comment><USER41> We will need more than a funny sig before the regex madness is ended ! ;-)

</comment></comment></comment><comment><USER43> "...in about 55 minutes"

about 55 minutes, meaning +/\- 30 years.

</comment><comment><USER44> Wish I had this resource when I had to learn regex.

</comment><comment><USER45> "...and now you have two problems."

</comment><comment><USER46> This is a very nice overview, but, knowing the rules of chess doesn't make you a chess master.

<comment><USER47> Agreed, but 55 minutes isn't going to make anyone a master of anything. The title is honest.

</comment></comment><comment><USER48> I love this!

</comment><comment><USER49> i've seen many regx sites, this one is DEFINITELY my favorite

i especially loved the page - loaded SUPER fast, no distractions - GREAT job!

love it!

</comment><comment><USER50> Commenting to also save some of the other recs HNers have provided.

<comment><USER51> This is not reddit so you get downvoted for comments like this because you are not contributing anything to the discussion. In the future you can upvote the story and then click on your profile and there is a link to saved submissions. Any submission you upvote will be saved in the saved submission list. Furthermore on reddit you can just click the "save" link to save things. I never understood why it was acceptable to post comments like this at reddit but that is just one of many why does reddit put up with X questions.

<comment><USER50> Am not a reddit user, nor did I know this -- but thanks (now I know).</comment></comment></comment>


How to Hire a Great Web Designer, With Y Combinator's Garry Tan - <AUTHOR> http://www.openforum.com/idea-hub/topics/technology/article/how-to-hire-a-great-web-designer-with-y-combinators-garry-tan-jolie-odell

<comment><USER2> Small tip: when you're 5-60 minutes away from San Francisco and still recommend stuff like outsourcing design or using 99designs, you might not actually attract "great" designers.

<comment><USER3> yes, I agree. I would never out source our design (other than logo, print). Design is absolutely strategic in nature.

</comment></comment><comment><USER4> Link to apply for listing in Garry's directory:

[https://ycdesign.wufoo.com/forms/y-combinator-designer- direc...](https://ycdesign.wufoo.com/forms/y-combinator-designer-directory/)

</comment><comment><USER5> Where the hell can we get this list??</comment>


Obscene Losses: How YouPorn is Killing the Adult Entertainment Business - <AUTHOR> http://www.portfolio.com/culture-lifestyle/culture-inc/arts/2007/10/15/YouPorn-Vivid-Entertainment-Profile

<comment><USER2> YouPorn follows YouTube in pretty much every way. It became popular because it served copyright infringing content that others charged for, and it makes little money.

The major difference however, is that YouPorn followed many pay porn sites and a huge volume of content, as opposed to YouTube which preluded TV really coming onto the web. Often you hear that the TV and movie industries have squandered their opportunity to make money off the web. YouPorn makes a case that no matter what the TV execs or movie execs had done before YouTube, the proliferation of free content would have happened anyway. People like free, even if it is inferior. DVDs have better quality than streaming, even downloading is better than streaming, but free beats 1 cent any day.

<comment><USER3> I think there's also a difference in the type of content. TV shows offer the possibility of mental stimulation. People will pay for quality. If I was able to, I'd get HBO for the level of programming. There's money to be made from quality.

Porn? Sure, it's wonderful when it's well-produced, but people don't care first and foremost about production value. They watch porn to masturbate in nearly all cases. That means that porn films benefit from shorter, more manageable scenes, and that quality doesn't matter whatsoever. The film industry has a subsection that operates based on quality. Porn profits almost exclusively from access: the easier access is, the more attention.

So TV still has some fight in it. So does the music industry, though I think in both cases there will be changes. Porn? I think that the professional industry is going to be gutted through-and-through. The porn industry can't compete with amateurs.

<comment><USER4> I agree with your sentiment that there is money to be made from quality, but you're underestimating the unrealized potential of the pornographic industry. The porn industry can't compete with amateurs _if it keeps doing what it's always been doing_. But that's just because the amateurs make an equivalent product at a lower price.

Most porn sucks (and blows), but one day pornography will be recognized as a proper art form and attract people who actually care about exploring the genre. Yes; porn is used exclusively for masturbation. But it's better to masturbate to a better product.

90% of mainstream pornography consists of dicks going really fast in and out of vaginas, punctuated by some guy blowing his load in the girl's face. It's hard to think of something involving sex that is _less_ exciting and creative than this. The real fun comes from subtle emotional interactions, power play, fantasy and a million other things I haven't thought of. High budgets and production values are worthless if you're only recording cumshots, but there are no reasons deeper than inertia and lack of imagination that this money and power isn't put to better use.

Assuming that parts of the HN crowd, in fact, watches porn: have any of you, for instance, ever seen a believable reenactment of a sexual fantasy? I sure as hell haven't. There is so much that could be done here. Sex is one of our deepest drives. Pornography has the potential to be one of the most profound art forms we have.

Consider what the advertising industry (clothing, underwear, perfume) is doing. They usually get blamed for destroying the woman's role, setting unrealistic expectations for people's looks, etc. But some of the things these guys/gals make actually has some emotional impact, on a sexual level deeper than what I see in most erotica and pornography. Although a randy ad never conveys any meaning or realism, the writing and acting is so much better. Fine art nudes are rarely effective at getting its viewers horny...advertising _is_. The highbrow crowd is obviously doing something wrong. Shouldn't artists put their effort where the impact is largest?

The porn industry will, happily, never get bailout money from the government. I'm hopeful that some competition will set the commercial porn studios thinking, or at least drag them down far enough that they can be attacked by teams with less financial clout. YouPorn is good for us, because of its equalizing potential.

<comment><USER3> I've been thinking about this. I'm a writer, and I've wondered whether it would be possible to get together a good director and good actresses and make a really good porno.

Right now? I think the answer's no. The problem is that you're going for two audiences: the porn-watchers and the content-seekers. The porn-watchers pay for the scene. The more scenes you have, the better. The content-watchers are the ones who'd watch something straight through if it was worth watching. The problem is, a large part of writing-directing is a matter of taste. When you're writing a sex scene into something, you only keep what you absolutely need to advance the plot. Most porn scenes are 10-20 minutes long, which means even if you only have one per film, you're making a really imbalanced product.

I can see writing an interesting, compulsive scene if you've got great characters and great acting, and if you weave plot in. But the more of that you add, the worse the scene gets for the porn-watcher. It's much more a zero- sum game, where you can't win with both at the same time.

And that gets to the bigger problem: porn is not intended to be art. It's meant to soothe people who aren't getting something they should _be_ getting. If you're getting great sex, you don't need porn. You can subsist entirely on art pieces that aren't erotic in that sense. I'd put porn in the same category as something like Office Space in that the main intent isn't artistic merit, it's helping somebody who's in a situation they don't like. The fact that it's no sex versus a dull job doesn't change the fact that neither one is quite as funny if you aren't in that sort of a situation.

(Art nudes, by the way, aren't meant to be erotic. Usually they're meant to capture the human body in its entirety, and there's nothing erotic about the human body unless it's actively teasing you. The novel Syrup has a great scene describing this. Nudes aren't sexy unless you've been teased with a partly- clothed body, and when the girl isn't deliberately denying you the sight of more.)

Now, I can see porn becoming more integrated with movies and TV. I can imagine, in a long-running TV show, a "moment of release" sex scene that literally climaxes seasons of building tension. But that's not the porn industry. That's a little porn added on to a much bigger thing.

Look at how porn is used in books. Pulp writers (Dean Koontz and kin) use it wholesale to raise reader interest during boring sequences. That's pornography in the current sense. Once you hit higher art, though, sex scenes are always used to portray something. You lose the full erotic impact. People aren't buying literature to jerk off: if anything, the jerking is incidental.

And so there lies the problem. Pornography is by its nature a low-brow product. If people pay for more, they'll pay for something that's not inherently pornography. And that means the current porn industry is screwed (ahahaha pun). If you want to masturbate, amateurs are perfectly fine. If you need a level higher, there's always piracy in the form of streaming legal videos, which the porn industry, shady as it is, can't compete with as easily as the RIAA can. They're fighting a battle with everything against them.

<comment><USER5> _I've been thinking about this. I'm a writer, and I've wondered whether it would be possible to get together a good director and good actresses and make a really good porno._

I believe the films Shortbus and 9 Songs attempt this to at least some degree.

<comment><USER6> 9 Songs does not attempt to be porno, i.e. does not attempt to stimulate the viewer, it imitates life instead (as any other art does). Main characters in 9 Songs are having sex like normal people do, unlike the porno actors and actresses.

</comment></comment></comment></comment></comment></comment><comment><USER7> _He shared his vision of turning YouPorn into a "very cool brand, perhaps the Virgin of adult entertainment."_

Did anyone else find this use of words a little amusingly oxymoronic?

</comment><comment><USER8> So instead of just being an industry, porn has firmly entrenched itself as part of our culture -- to the point that everyone is not just a consumer, but also a participant, and it will get harder and harder to make money at it?

Parallels with the music industry as well as movies and video?

</comment><comment><USER9> FYI: YouPorn runs on the Perl-based Catalyst framework (supposedly -- not sure how it was verified).

<comment><USER10> This makes it awkward when clients or people in my training classes ask me about big Catalyst sites. "Uh, YouPorn..." "What's that?" "Uh..."

<comment><USER11> So mention other sites instead - the BBC iPlayer website, vox.com, etc.

Or you just say "two sites in the alexa top 100 that we know about"

It's not rocket science.

</comment></comment></comment><comment><USER12> The article is actually more than a year old. Traffic seems to be declining at youporn. I wonder if that means dvd sales are up.

[http://www.alexa.com/data/details/traffic_details/youporn.co...](http://www.alexa.com/data/details/traffic_details/youporn.com)

<comment><USER13> Nah, it means youporn has competitors.

<comment><USER14> I would make an interesting/funny/insightful comment here if I could leave anonymous comments.

<comment><USER15> But enabling anonymous comments would just hurt things in the long run, no matter what kind of additional positive short-term effects it would have. People would feel little need to "join" the community, as they could interact with it as guests, and thus they would always feel out-of-touch with it, and apathetic to it (it would be outside their Monkeysphere.)

I do have one possible solution, though: for every 50 karma points you earn, say, you get a "free gift" of some sort _within the system_ (because otherwise it would encourage gaming of the system to earn such points). One gift could be a one-use "post this comment anonymously" checkbox that would then disappear. Another would be, to use a fun example, the sort of "mega-upvote" everyone wishes they had around for when something truly deserves it.

<comment><USER16> I think it'd be interesting if people could use their own karma for the "mega- upvote."

EDIT

Part of what's neat about this idea is that support now can cost people something, so they have to really be behind what they support. On the other hand, it would probably establish a oligarchy.

<comment><USER15> The problem is that capabilities on this site in particular are partly based on your karma. Spending away your ability to downvote would be a problem, especially if you're a very prominent member of the community, and then even more especially if you served in a sort of vigilante "moderator"/"role model" role, keeping the community clean and pointed in the right direction by your actions. (I know this site can't really be influenced as heavily by its users as that sounds, but it could head that way if pg wished: giving users with a karma total of over 3000, say, automatic moderator powers makes quite a bit of sense to me.)

Sure, it can be a "noble sacrifice" and generate some sort of epic story retold throughout the community where user-Gandalf sacrifices their karma in the fight against troll-user-Balrog, and then others step in to "forge ahead without them," but just because a notion is romantic doesn't mean it's Utilitarian (in fact, they're almost opposite by definition.) Although boring, the community as a whole is likely better off if the others could restore Gandalf afterwards, _as long as they thought his actions were justified_. Since, in a database, there's no difference between taking something away and instantly finding reason to give it back, let me phrase it this way (thank Doctorow for this):

You don't _spend_ whuffie; you just _have_ it. However, if you do something stupid with it, it can be taken away.

I'm not sure if this has been tried on a social news site before, and it sounds stupid on face-value, but, what if, instead of each comment having an individual score that _also_ affects its author's karma, the comment's score (and therefore its page placement) simply _ _is_ _ the author's karma? That is, a comment by a user with 3000 karma starts off with a score of 3000, and is placed on the page accordingly.

As such, you wouldn't really be voting on the comment itself anymore, but rather voting _on the user_ by considering the comment as an action _by_ that user. Taking all your points off of a user for one especially bad thing they did--considered on sites like this and reddit to be quite uncouth--wouldn't be a "sin" any longer, because _you're not rating their comments_ any more; you're just rating _them_. When you give someone one downvote, it applies across the "scores" of _all_ their other posts, and likewise for upvotes.

I'd love to see this system tried out. I don't even have a special attachment to its success or failure; it simply sounds like a great experiment in virtual sociology. I might even be motivated to implement it myself if anyone else shows interest here in being part of the resulting community.

<comment><USER16> I wish there were a good way to try out all these ideas. I've considered the idea of wikiable applications, perhaps on top of a common database, that might be a possibility.

</comment></comment></comment></comment></comment></comment></comment><comment><USER17> The major difference between hollywood vs youtube and san fernando vs porntube: $500 million movie may actually be better than some guy in his garage with a video camera. A $50,000 porn movie however, is almost certainly less interesting than a video of two people having real sex.

</comment><comment><USER18> Not really bringing anything to the conversation but 7 page article, really? Way to try to milk those ads...

<comment><USER19> It was a good article. I clicked my way through. I'm happy to generate ad revenue while consuming an article I liked.

Make something people want.

<comment><USER20> You "consume" articles?

<comment><USER19> I do. I also devour, absorb, take in, chew on, consider, ponder...etc.

<comment><USER20> All that must need a lot of synergy, huh?

</comment></comment></comment></comment></comment><comment><USER21> when anyone is willing to make regular sex videos and upload them for free the future is in sites like kink. find highly specialized niches and serve the people willing to pay for them. I envision a website where people can request videos of certain themes. pornstars could choose to make certain themed videos and then offer them to customers.

</comment><comment><USER22> The implications behind this research are benign, I swear.

The one company I see coming out of this is Brazzers. They seem to have partnered up with YP and a lot of clones to generate traffic and more leads through short "review" videos. And there the only real brand that has been embracing the new shift, including the social aspects.

</comment><comment><USER23> Vivid and others do have a valid point that Youporn could eventually get into a LOT of legal trouble because of age issues.

</comment><comment><USER24> Soon we will see Twitter for Porn. "@exgrilfriend Having fun with your best friend."

<comment><USER25> <http://hotwitter.com/> ... not particularly work-safe, powered by Yonkly</comment></comment>


Ask HN: Review My Startup - <AUTHOR> Introducing Gelry: https://hammadn.wixsite.com/gelry It is Jewelry but as a tech company.
An all in one jewelry box which contains necklace, bracelet, earring, hair-clip, finger-ring one each - which are designed by AI & is sold as a software product giving monthly updates as another jewelry box which contains updated designs.
Would love to have your feedback. Signup if interested. <comment><USER2> Hi! I didn't quite get it. What does it mean "designed by AI"? And do I get real jewelry if I subscribe? If so, who makes this jewelry from AI design?</comment>


CERN is the Doomsday Machine - <AUTHOR> http://www.misunderstooduniverse.com/France_Builds_Doomsday_Machine.htm

<comment><USER2> This article is laughable.

First of all, all of this controversy has to do with the Large Hadron Collider (Black Holes) and the Low Energy Antiproton Ring (antimatter). Much else goes on at CERN.

Secondly, they are going to be making extremely tiny amounts of antimatter (just enough to study it's effects). Not enough to blow up anything significant. Antimatter is really, really hard to keep around and control. See: [http://public.web.cern.ch/Public/en/Research/Antimatter- en.h...](http://public.web.cern.ch/Public/en/Research/Antimatter-en.html)

Third, the "mini black holes" they are making are nothing like what a layman would consider a black hole. They will be only the mass of a few thousand protons and if our current understanding of particle physics is even close to correct they will evaporate almost instantaneously. The funniest part of this whole thing is extremely high energy cosmic rays have been making much higher energy collisions on earth for it's entire existence.

This is all about laymen getting up in arms about things they don't understand. The scientists shouldn't have called them black holes in the first place as it incites ignorant people to speak out when they know very little. With all the science fiction surrounding black holes anyone could have predicted this kind of outrage. See: <http://public.web.cern.ch/Public/en/LHC/Safety-en.html>

</comment><comment><USER3> If black holes usually get created by collapsing massive stars (much bigger than the sun), then how could CERN possibly create a black hole? I don't know too much about the particle physics of black holes, but it doesn't seem to make that much sense.

Black holes basically happen because the gravity of the thing overcomes all other forces because its so incredibly massive in such a small space (overcomes the forces keeping atom's nuclei apart too). Smashing together a few protons together might make those proton nuclei to crash together, but I don't see how that could possibly make a black hole.

To me, any crazy thing like a black hole that could destroy the earth, is far too energetic and ridiculous for humans to actually make unknowingly. (for now I guess)

I'm sure the smart dudes at CERN thought about this and aren't worried.

</comment><comment><AUTHOR> I'm sure this is an exaggeration but I do not know enough to dispute it. Anyone have any knowledge about this?

<comment><USER4> I think there are very few people in the world that know enough to dispute it.

</comment></comment><comment><USER5> It's shocking to know that such: [http://www.dur.ac.uk/astronomical.society/includes/archive/n...](http://www.dur.ac.uk/astronomical.society/includes/archive/nov2006/sky_falling.jpg) an attitude towards science is so widespread.

The video featuring the earth collapsing is fun. But science is even more fun. Don't stop the geek. Let 'em rock the universe.

</comment><comment><USER6> "the exception that proves the rule" - a quote that can pretty strongly demonstrate idiocy of an argument.</comment>


Bug bounties are a joke - <AUTHOR> it's the same run-around:
they tell you it's a feature or 'supposed to be that way' and then when abused fix it and you get no pay
or they give low-ball offers and or delay payment ,etc. with very onerous TOS <comment><USER2> I think the community would be interested in this topic, but you should start the conversation with something more substantive, such as:

\- talking about your particular bad experiences

\- a theory about why some companies are better than others

\- what companies should do to improve their bounties

\- data showing that bounty payouts are cheap compared to breaches

</comment><comment><USER3> There are two kinds of buyers for bugs, if you let the market decide bounties might be more rewarding ;)</comment>


Why Does the Cloud Stop Computing? Lessons from Hundreds of Service Outages - <AUTHOR> http://muratbuffalo.blogspot.com/2016/11/why-does-cloud-stop-computing-lessons.html <comment><USER2> When a service makes significant SLA promises, usually it is not a promise of uptime but a promise of what the service provider will pay you for the lack of service.

</comment><comment><USER3> What are some examples of recovery blocks and N-version software mentioned in the blog post?

<comment><USER4> Here's a few links along these lines that might interest you. They are an intro, recovery-oriented computing, a survey that includes N-version, and a recent survey including some byzantine fault-tolerance.

[http://crystal.uta.edu/~kumar/cse6306/papers/FaultTolerantDi...](http://crystal.uta.edu/~kumar/cse6306/papers/FaultTolerantDistComp.pdf)

[http://roc.cs.berkeley.edu/papers/ROC_TR02-1175.pdf](http://roc.cs.berkeley.edu/papers/ROC_TR02-1175.pdf)

[http://www.pld.ttu.ee/IAF0030/Paper_4.pdf](http://www.pld.ttu.ee/IAF0030/Paper_4.pdf)

[http://sirocco2016.hiit.fi/preproceedings/Recent_Results_on_...](http://sirocco2016.hiit.fi/preproceedings/Recent_Results_on_Fault- Tolerance_Consensus_in_Message-Passing_Networks.pdf)</comment></comment>


Charles Koch on Tim Ferriss [126:24] - <AUTHOR> https://tim.blog/2019/08/11/charles-koch/ <comment><AUTHOR> As someone who thought he could never agree with a Koch brother, this was eye- opening and made me question my bigotry in a direction the term is not usually aimed towards.</comment>