Metagenomic Analysis of a Blood Stain from French Revolutionary Jean-Paul Marat - <AUTHOR> https://www.biorxiv.org/content/10.1101/825034v1 <comment><USER2> Metagenomics is the biological equivalent of suddenly being able to see dark matter.

Normally, if you want to analyze a microbe, you do it by culturing the organism in Petri dishes. By varying the growth medium you can find out a lot about your organism: what it eats, if it breathes, how it metabolizes various things. The problem is that only 5-10% of bacteria grow on plates. Microbiologists call this the "plate count anomaly" and what it means is this: your sample in a microscope could be teeming with life, but if you plate it you'll probably get this homogeneous little sample of not very many organisms. The rest are called "microbial dark matter."

With metagenomics, we could see them all. It made people a little funny in the head. You might remember that "The Microbiome" was a big idea in the media for a while. It got pretty flattering treatment, considering what it is: a mass of mostly proto-shit floating around inside your colon. But the enthusiasm wasn't too far misplaced, because a major area of biology is growing by leaps and bounds now.

If you are a computer programmer considering a career change you should really take a day off to look into the new genetic technologies on offer. Performance is doubling every year [1]. The world is changing. And computing is at the center of it, both practically (all that research generates a lot of data) and conceptually (because gene expression is information processing). So give it a look.

[1] Remember that? [https://en.wikipedia.org/wiki/Moore%27s_law](https://en.wikipedia.org/wiki/Moore%27s_law)

<comment><USER3> >If you are a computer programmer considering a career change you should really take a day off to look into the new genetic technologies on offer.

What resources would you recommend, and do you have any advice for someone who is just starting their career?

<comment><USER2> It depends on how big a commitment you want to make. I quit my job to go study biology and it worked out pretty well for me. Programming opens doors for you because the majority of biology grad students can't do it. You get good work and an accelerated path through classes, TAships, research and other university business. If you want to work in IT, the experience you get is perfect for applying for prestige places like Google, Facebook or Amazon. Mostly I've spent the last year writing pattern matchers to extract subtle patterns from huge data files.

If you're not ready for a big commitment (and even if you are), I'd recommend taking some classes too get a feel for the subject. Khan Academy has two (or you can google around for more) that look pretty good. The just-plain-Biology one covers a surprising amount of useful information. The one on Genetics is useful too, although you might want to skip past some of the stuff about cross-breeding animals and whatnot.

Another thing you can look at is Synthetic Biology, which is biology plus design, biology for hackers. Synbio says biology has been too interested in describing and cataloguing, and not interested enough in building. So even though what we can do is pathetically simple next to the evolutionary process that designs new organisms, we can still do little things like making human beings immune to all viruses and designing cyanobacteria that produce crude oil from air, water and sunlight. If you're interested in Synbio you should check out the iGEM competition, which is a major event and an organizing site for useful information.

If you don't feel like crawling around the iGEM database of standardized biological parts (it's like the library docs for Life) you could look at these videos instead: [https://www.ibiology.org/playlists/synthetic- biology/](https://www.ibiology.org/playlists/synthetic-biology/)

Email's in my profile. Don't be a stranger if you have questions.

<comment><USER4> Though I'm still very early into it, I can highly recommend starting a biochemistry degree, if you already have a programming/computer science background. Bioinformatics would be the direct route to that field, but in a bioinformatics degree, there is usually still not much of a focus on the low- level biochemical mechanisms and biochemical methods that form the basis for all the data you will be working with. Biggest downside though is a lot of lab-time, which for me personally is hard as I'm still freelancing on the side.

I'm only in the middle of my second semester and through taking a few biochemistry classes in advance and reading though the papers of our universities research groups it's already starting to come together a bit. Things start to click and I'm getting pretty far in trying to understand and reproducing some SOTA papers in weekend projects. For such a short amount of time of studying the subject, I think that's a pretty good payoff.

</comment></comment></comment></comment><comment><USER5> > The advent of second-generation sequencing technologies allows for the > retrieval of ancient genomes from long-dead people and, using non-human > sequencing reads, of the pathogens that infected them.

This is pretty cool. I'm not sure what state of the art is in DNA sequencing, but it sounds like this is impressive. The abstract mentions that it's the oldest DNA sequencing sourced the celluloid (a newspaper in this case), but I don't know if there are successes from other sources that are older.

<comment><USER2> Second generation sequencing is fast and in wide use. Third generation sequencing is the new hotness

[https://en.wikipedia.org/wiki/Third- generation_sequencing](https://en.wikipedia.org/wiki/Third- generation_sequencing)</comment></comment>


Low-Power And RF Design Heighten Signal-Integrity Concerns - <AUTHOR> http://chipdesignmag.com/sld/blog/2010/01/28/low-power-and-rf-design-heighten-signal-integrity-concerns/ <comment><USER2> A topic not adequately covered in this topic, IMO, is corner-case testing. E.g. testing across temperature, supply voltage, and especially Si process variation, in the simplest example. EDA tools of ever-increasing sophistication definitely help economize on time-to-market, assuming you understand your tool chain adequately, but it is still actual unit testing, in temp chambers and similar apparatus, that is your most loyal ally in catching flaws before production. Indeed, a large video graphics company I interacted with recently would run their newest cores through corner-case testing across something like 20 different axes. (Imagine a chip with several voltage domains, e.g. core, GPIO, memory, and some sort of GHz-domain serialized interface, now multiply the number of domains by additional factors such as operating temp and Si process variation, and you get a hypercube representing all possible corner cases.)

Testing across corner cases is exhausting, and yes, proper design discipline coupled with EDA proficiency give you a sporting change of avoiding a reduction in performance goals (at best) or even a re-spin (at worst).

But sending a bad chip to market is often a company-ending act for anyone not in the Fortune 500.</comment>


French Ideal of Bicycle-Sharing Meets Reality - <AUTHOR> http://www.nytimes.com/2009/10/31/world/europe/31bikes.html?_r=1&hpw=&pagewanted=all <comment><USER2> I remember from the summer I spent in Innsbruck, Austria (my dad was teaching on a summer abroad program for American students) in 2003 that there were hundreds of bikes standing on orderly bike racks or improvisationally leaning against various structures on nearly every nontrivial street.

The biggest surprise to someone just coming from America is that very few of them were locked, and it did not seem to be a major concern for anyone. I remember asking if the bikes commonly get stolen and the responses seemed to suggest that while nothing is wholly impossible in principle, in practice the answer was no.

Innsbruck is not a wholly homogenous city, though it is certainly much smaller than Paris (+/- 100k, all told); there are lots of foreigners, and in particular, a fair number of Turkish, Yugoslav and miscellaneous immigrants, many of whom would certainly be characterised as poor and/or working in low- wage service industry. There's plenty of graffiti, some evidence of other kinds of vandalism, and other such things.

Yet somehow, the bikes don't seem to get stolen, and nobody has any qualms about just leaving theirs outside, or in the hallway near their apartment, etc.

I am not sure what to conclude from this, other than that these things vary greatly by the prevailing mood of the society.

<comment><USER3> Uhm, yeah, that's certainly not universal in Europe. I had 4 bikes (including having the locks cut) stolen in 2 years in Berlin before I just gave up.

A lot of people here get cheap old bikes just because they're the least likely to get stolen (though I had two of those stolen too).

<comment><USER4> Bikes get stolen pretty quickly here too, even with the vélib bikes readily available (and only about 20 euros for a year pass), if you leave them in the wrong places. A friend of mine's had two stolen in a month because he left them outside at night.

</comment></comment></comment><comment> bjelkeman-again

      Daily use averages 50,000 to 150,000 trips, depending on the
      season, and the bicycles have proved to be a hit with
      tourists, who help power the economy.

      At least 8,000 bikes have been stolen and 8,000 damaged so
      badly that they had to be replaced — nearly 80 percent of
      the initial stock, Mr. Asséraf said.

      JCDecaux must repair some 1,500 bicycles a day.

It would be interesting to see what the comparable numbers are in Stockholm, where they have a similar effort running, but I haven't seen a single vandalised bike.

[http://www.flickr.com/photos/bjelkeman/2436951384/in/set-721...](http://www.flickr.com/photos/bjelkeman/2436951384/in/set-72157604696313849/)

<comment><USER5> This article seems oddly focused on France. I also know of similar efforts in Germany. And I have seen similar bikes in Spain.

It would be much more interesting to get a European perspective.

<comment><USER6> Not just European: Montreal, Canada has this too: <http://en.wikipedia.org/wiki/Bixi>

Interestingly enough, vandalism seems to be much lower, though still significant: "...one in five bikes have been damaged and 15% of bike racks are defective..."

<comment><USER7> While many bikes are still defective, they have fixed the problem with the racks that allowed people to steal bikes (and break the rack at the same time).

</comment></comment></comment></comment><comment><USER8> Anyone whose owned a bike knows that maintenance is actually a pretty big deal (it's not difficult, but you need constant vigilance) and that should have been a huge warning sign before Paris started putting this plan into action.

Aside from that the vandalism situation compounds the problem. The class struggle aspect to it in France is interesting. I'm not sure that issue would be as bad in other regions, but surely vandalism would exist at some level everywhere.

Personally I would much rather like to see governments seek an actual policy on bike storage and encourage people to buy their own bikes. As has been discussed before, in most cities there has been little to no thought put into where people will store their bikes at home or at work. I think this is a key driver why many don't see cycling as a sensible option for their commutes. Until this issue is adequately solved, cycling will be inaccessible to many.

<comment><USER5> I know that in all big cities in Germany bikes are widely used. (We use bikes to go to places, we don't go to places to use our bikes :) Many don't even own a car. I cannot imagine that the bike infrastructure in Europe is really all that bad. Such rental services are only a extra. And I have read other articles that seem to indicate that such services work quite well. Nothing about the service in France, per se, but about other services.

<comment><USER9> In Germany the Deutsche Bahn (railways) has bought the provider of such rental bikes. Not sure if they actually make money or if it is just a prestige project. But they have existed for several years now.

The bicycles look so special that stealing them is probably not very tempting. Vandalism might still be a problem, though.

</comment></comment></comment><comment><USER10> Having used the velibs in my visit to Paris last week, I feel that the article is making the program seem bad on purpose. As a tourist, I found it a brilliant idea.

Typically, out of about 30 or so bicycles in a station, I usually found about 2 in a bad condition. And they were usually NOT vandalized. It was most often a punctured tyre, a bent or missing basket or something similar.

The most serious problem that I found was the fact that sometimes all the docks in the station near your destination would be occupied. I quite liked the bikes themselves, and found them in some respects innovative, but I can't imagine that they cost 3500€. To register in the system you use a credit card from which 150€ is temporarily kept as a guarantee. I can't imagine that the price of the bike is over an order of magnitude more than that.

I wish my home city (Athens) had a program like that.

</comment><comment><USER11> Comment on the ground - quoted in the article - is that the scheme is "not a complete success". But reading the article as a whole, you'd hardly think that - you'd think it's a complete failure.

<comment><USER12> Which shows that not every article you read in the press is accurate.

It's easy to use a bunch of misleading statistics, put them out of context, and paint a situation that sounds much worse than it really is.

What I can say for sure is that I know many people in Paris who love the program. You must understand that it's a much better alternative than owning a bike. You can really pick up the bike only on the segment you need them for. Normally, you move around Paris by metro, but there is often some distance ("the last mile") that a bike can do best. But you certainly wouldn't want to do your entire trip by bike...

I think the article exaggerates the cost per bike ($3,500) and the 10,000 bikes/day under repair sounds plain bogus. And then there is no accounting for how long the program has been in place, when they say that 80% of the original bikes have been damaged.

<comment><USER11> I've been in Paris a number of times and used the system; the biggest issue I've had was finding a bay when time was running out for a charging boundary, as they are on side streets, rather than main thoroughfares. I don't generally have any complaints with the system; rather my complaint is with the article and its odd bias.

So, I presume you don't mean me when you say "you".

</comment></comment></comment><comment><USER13> There is no way a bike costs that much. Unless they hide gold under the seat, that is. They must be counting other expenses, like salaries or repairs and dividing by the number of bikes.

And before feeling too sorry for the poor company that provides the service, note that it thus obtained a monopoly on advertisement in Paris, which is _a big deal_. They regularly have columns in the newspapers complaining about vandalism, and how it's destroying its business, but they never complain that they got too much advertising space ;-)

Also bike costs are shared with the city. I have not subscribed to the service, since I very often see bike stations which are:

1) either full of bikes (no way to dock yours) 2) or with no bikes ready to ride at all

which means it lacks one of the fundamental aspect you would need from such a service: reliability. Technically, they are supposed to be moving bikes from stations which are full to stations which are empty but I have the feeling this is less likely to happen.

That's why I prefer having my own bike, even if it may be a pain to find a good place to park it.

For some reason, parisians don't feel the same way I do about reliability. They still use public transport and use the bike (when available) to go to/from the closest metro station.

</comment><comment><USER14> The city where I studied, Rennes in France, has such a scheme in place since about 9 years ago and there haven't been any vandalism that I could see...

One thing though is that a lot of people preferred their own bikes because the bikes were not all that nice to ride (and I guess that Rennes being a small city, it's not all that useful to be able to get a bike on the last leg of a commute)...

<comment><USER15> We have a similar bicycle share program in Ottawa. I haven't seen any vandalism. The bikes always look clean and new. Possibly because only a few people use them.

</comment></comment><comment><USER16> There's been a push in my area to introduce a similar concept, but with cars. It's based off of the San Francisco model:

<http://www.citycarshare.org>

Anyone from the Bay area have any feedback?

<comment><USER17> CityCarShare is fantastic if you live somewhere with sufficient density that driving is (truly) not necessary for most trips.

We use bicycles, public transportation, and walking for nearly all of our trips, but rely on citycarshare for shopping, moving furniture, occasional weekend trips, etc. We also use a corporate car share account to move servers to/from the colocation facility.

It's a fantastic service -- far cheaper than owning a car, and zero-hassle. I hated dealing with the complexities of car ownership, from insurance and DMV registration to regular maintenance, speeding/parking tickets, and the general agitation of driving.

If you've never lived without a car, it can be surprisingly liberating to sell yours off.

With the money you save not owning a car, you can afford higher rent for a more desirable area, longer-term car rentals for one-off trips, etc.

</comment></comment><comment><USER9> "Many of the specially designed bikes, which cost $3,500 each"

What were they thinking???

Surely it must be possible to design a cheaper bike for that purpose? The electronics shouldn't be much more complicated than an average mobile phone?

<comment><USER18> Over-engineering. They could have done the same with bikes that cost significantly less.

<comment><USER19> It's kinda like how London buses are made by Mercedes. You might think that's an extravagance - but if things are to be used hard every day, it's a false economy to cut corners up front (unless you go so cheap they're effectively disposable).

<comment><USER20> Many delivery vans are made by Mercedes, too. There's nothing extravagant about them - they are just good quality delivery vans.

There's Lamborghini tractors, too! <http://www.lamborghini-tractors.com/>

</comment></comment></comment></comment><comment><USER21> [http://www.streetsblog.org/2009/02/12/reports-of-velibs- demi...](http://www.streetsblog.org/2009/02/12/reports-of-velibs-demise- greatly-exaggerated/)

I would be surprised if JCDecaux's PR department were not at least partially behind this.

(I go to Paris frequently. The bikes mostly work fine, and everyone loves them. Here in Barcelona the system works pretty well, too.)

</comment><comment><USER22> I live in the Financial District in Manhattan.

We have this free bicycle rental service: Bike Around Downtown <https://www.bikearounddowntown.com/Default.aspx>

</comment><comment><USER23> Why didn't they just subsidize bike and bike lock purchases for individuals?

<comment><USER24> What is great with this program is that you take the bike only when you need it. You don't have to carry it with you all the time. You can combine subway, bus and bike. There are a lot of stations around Paris. You can use the bike one way only if it is raining for example, and use the bus/subway to go back.

<comment><USER25> > You can combine subway, bus and bike.

You can do the same thing (though not _quite_ as convenient) with a folding bike.

They could put a plan in place to offer incentives for people to buy some standard folding bicycle. Folders are expensive because there aren't too many produced and because they need to be fairly light, however, mass-produced they shouldn't be too expensive.</comment></comment></comment>


San Francisco Opens The City's Data - <AUTHOR> http://www.techcrunch.com/2009/08/19/san-francisco-opens-the-city%e2%80%99s-data/ <comment><AUTHOR> Site doesn't seem that polished, since hitting the logo gets you an error</comment>


New Study Links Zika Virus to Temporary Paralysis - <AUTHOR> http://www.nytimes.com/2016/03/01/health/zika-virus-guillain-barre-french-polynesia.html <comment> amar-singh Hi,

Researchers need to innovate a vaccine for this Zika virus as it spreading fastly.</comment>


The World of Everyday Experience, In One Equation - <AUTHOR> http://www.preposterousuniverse.com/blog/2013/01/04/the-world-of-everyday-experience-in-one-equation/ <comment><USER2> The best line in the linked article: "I don't want a notational shortcut to undermine my argument and leave the audience believing in God."</comment>


TicToc: Time Traveling Optimistic Concurrency Control [pdf] - <AUTHOR> http://people.csail.mit.edu/yxy/pubs/tictoc.pdf <comment><AUTHOR> Related paper by the same author(s): [https://news.ycombinator.com/item?id=10252691](https://news.ycombinator.com/item?id=10252691)</comment>


Teleport Flock – Planning Physical Meetings for Remote Teams/Groups - <AUTHOR> https://flock.teleport.org/

<comment><AUTHOR> Really like what this team is building. We have plenty of tools for people that live in one city and travel occasionally, but very few tools for those that want to rotate multiple locations for a few months at each spot.

If we had a better way to have a registered agent for acceptance of physical mail, tax docs, etc while living a nomadic life, I think many more people would do this.</comment>


[Guide] Block Buyurl.net Referral Spam - <AUTHOR> http://www.sudorank.com/guide-block-buyurl-net-referral-spam/

<comment><USER2> Any way to block people submitting every single blog entry? [https://hn.algolia.com/?q=how+to+block#!/story/past_week/0/h...](https://hn.algolia.com/?q=how+to+block#!/story/past_week/0/how%20to%20block)

<comment><USER3> You can send a email to the moderator: firstname.lastname@example.com (better search: [https://hn.algolia.com/?q=how+to+block#!/story/sort_by_date/...](https://hn.algolia.com/?q=how+to+block#!/story/sort_by_date/prefix/0/block%20sudorank) )</comment></comment>


Dear Recode.net how in the world.... - <AUTHOR>

How in the world would I know what the icons in the upper corner of http://recode.net/ are supposed to mean w/o hovering or clicking?
What's the reason for being so cryptic?
It's not cool to make me think. Stop trying to reinvent for the sake of being different. <comment><USER2> I am really confused about what the problem is. Unless you are seeing something different from what I am seeing. The icons are obviously email, twitter & Facebook.</comment>


Prion Disease Can Lurk in Your Brain for 30 Years Before Quickly Killing You - <AUTHOR> https://gizmodo.com/prion-disease-can-lurk-in-your-brain-for-30-years-befor-1823628617 <comment><USER2> The article doesn't mention the outbreak in Europe (mostly in the UK), which peaked in the early 1990s. Fortunately (based on the graph in Wikipedia) the tail end of that looks pretty low. [https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopat...](https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy#Europe)

The European outbreak was probably caused by feeding contaminated protein supplements to cattle. It affected quite a few more people than the contaminated dura mater grafts in Japan.

<comment><USER3> ... and as a result anyone who lived in Europe during the 1990s is disqualified from donating blood in the US.

<comment><USER2> Yeah, that's how I know about it. I spent some time in England in the early 1980s. So it affects me. But I did get my gallon pin before they kicked me out. Which means that there could be hundreds of Americans walking around with foreign prions, just because of me. :)

The real advantage of being kicked out is that once you tell them the reason you can't give anymore, they ghost you. Totally. No more phone calls literally begging for your blood. :)

The funny thing is, I'm sure, all the English are donating blood to one another. And they're surviving.

I can see the opposite viewpoint as well. If even a single American got BSE from "foreign" blood, there would be an incredible shitstorm. And the poor recipient would have received the equivalent of a death sentence.</comment></comment></comment>


Ask HN: How old are you (optional) and what was the last thing that you learned? - <AUTHOR> Doesn't have to be tech related. <comment><USER2> 44, a former coworker that I would go see once a year at a coding conference just passed. He was 47 and left behind a wife and three young daughters.

I learned never to take today for granted and don't put things off for tomorrow with your loved ones. Your job will send flowers to your family and then open up a req for your position. Don't put your job before your family.

</comment><comment><USER3> 24\. Why nuclear weapons produce a double flash. I'd read that was a signature of a nuclear detonation (Clancy novels, sue me) but not _why_. Turns out it's because the shock wave is hot enough in the early stages of the explosion to become opaque, blocking light from escaping. As it expands, the shock wave cools and becomes transparent again, letting the light from the fireball inside escape.

</comment><comment><USER4> I play this game airsoft (like paintball) and I like to go especially on beautiful days like today. It's so much cardio and you don't even notice it. Anyways, this Canadian company makes these really innovative reusable bang grenades and I finally learned how to toss them just right to clear out rooms. In movies the badass hero makes perfect throws without even thinking. But turns out in real life having your gun in your main hand, pulling the thing out with your non dominant hand, pulling a pin, and then getting it throug an opening, while hoping and praying nobody gets the jump on you is really really hard. Before this I would blow myself up, or forget to pull the pin. Oops.

<comment><USER5> So true, it really is amazing that you don't even notice the exercise when combining it with something funny/purposeful. I was in a milsim game some years ago, in a room at a military training site with my mate, and suddenly we see something thrown inside the room, and we just know that we gotta get out, so we scramble for the door only to get stuck shoulder to shoulder getting shot in the back by a guy in the window. The "grenade" was a brick .. :)

</comment></comment><comment><USER6> 33\. Most guitar tabs for The Beatles' Norwegian Wood are wrong -- they have the intro accurate, but it's not the same as the part played under the lyrics.

And it's not just that the song is played on a sitar -- even the sitar isn't mirroring the intro to the song through the lyrics. Look at, for example, this tab ([https://www.guitartabsexplorer.com/beatles-Tabs/norwegian- wo...](https://www.guitartabsexplorer.com/beatles-Tabs/norwegian-wood- tab.php)), which explicitly says "Use same guitar pattern under solo voice". Now listen to the song ([https://www.youtube.com/watch?v=OYs02z35F24](https://www.youtube.com/watch?v=OYs02z35F24)), which doesn't use the same pattern under the voice. It's a good accompaniment, but it is just different.

<comment><USER7> Many (and possibly most) guitar (and bass) tabs for songs are (unfortunately) wrong. Likewise very many chord boxes and often the chord names themselves are wrong. There are notable exceptions (eg "Standing in the shadows of Motown" \- the transcription of James Jamerson's basslines is genuinely superb).

There's really no substitute for listening really closely to music you really like and figuring it out for yourself. I have boxfiles of transcriptions I did and if nothing else, it improves your ear to the extent you get faster and faster not only at doing transcriptions but at learning music generally.

<comment><USER6> That's hard to get started! It does sound powerful, but it also seems like a daunting task for your average chord strummer, like me.

</comment></comment></comment><comment><USER8> 47m, I was reading about installing Kubernetes the hard way, when I learned my 9yo son is a badass sniper in Fortnite.

</comment><comment><USER9> 38\. Eveyone spent 4 months inside their grandmother (as an egg inside their mothers fetus)

<comment><USER10> Wife and I were just talking about this and how this is a great example of how decisions made in one generation can have consequences that span multiple generations (eg. Eggs, where one's family immigrated to, etc)

</comment></comment><comment><USER11> 26- I learned that my body is not as "unbreakable" as it was ten years ago

<comment><USER12> 39\. I feel the same way as you!

<comment><USER13> A forty year old body takes twice as long to heal as a 20 year old body :( I learned this quite some time ago but it still seems surprising.

<comment><USER12> Hah - Surprising yep. And dissappointing too :)

</comment></comment></comment></comment><comment><USER14> 29; the last thing I learned was the importance of sleep, which I've heard about before but never really internalised until now. One of the coolest parts of this that I learned is how in certain stages of sleep you get this stuff called "sleep spindles", the activity of which is associated with memories from your short term memory buffer in the hippocampus being relocated to your long term memory in the cortex. This sleep spindle activity can be measured in pulses in your brain during this stage of sleep, pulsing between the hippocampus and the coretex at a rate of 100-200ms. Upon waking you are left with longer term recall of what you had learned pre-sleep, plus your short term memory buffer in the hippocampus is now free to learn new stuff. Our brain is so exciting!

</comment><comment><USER15> Not to get emotionally involved with a product that could be turned off at any time. And that just because a business is more popular and better technically than it's competitors doesn't mean it doesn't have problems behind the scenes. And on a related note, if you don't have something downloaded to your own hard drive, you don't really own it.

</comment><comment><USER16> 46, I took Discrete Math I & II this past spring. It wasn't easy. Last math class I has was (failed) Calculus I in 1989 and (failed) again in 1990.

I got a B+ and an A- this time, but I probably put in 30 hours per week studying and doing homework.

<comment><USER17> Just out of curiosity as I'm probably closer to your age than I am to the majority of folks here, are you taking these classes as part of a grad program in CS or related?

<comment><USER16> Undergrad. I never completed my degree so my manager (and his manager) encouraged me to go back to school and finish...especially since they are paying for it.

<comment><USER18> That's awesome. Good luck in completing your degree.

</comment></comment></comment></comment><comment><USER19> 44 - Learned how to use a 4.25 inch grinder to strip apart a safe that I can't move. I now realize that padlocks are just there to keep the honest people honest.

</comment><comment><USER20> 55\. Just stumbled across a philosophy course online. I had always thought of philosophy as archaic, useless and boring. I could not have been more wrong.

<comment><USER21> Could you provide a link to the course. Id like to check it out.

<comment><USER22> Not the parent but check out Philosophy Crash Course in YouTube. You can thank me later :D

</comment></comment></comment><comment><USER23> 42, Machine learning. I discovered Coursera for me and worked through a number of courses. People say that learning is getting more difficult as you get older, but so far it is getting easier for me. When I was younger I didn't have the patience to learn something if I had no immediate need for it. There were distractions everywhere. Now it is much easier for me to focus on a single thing.

</comment><comment><USER24> 48\. Started learning music theory, so far by means of parts 1 and 2 of "Music Theory for Electronic Music" on Udemy. I dabbled in music in my 20s but never really knew what I was doing so it's amazing fun.

<comment> 52-6F-62 Oh if you missed this you should check it out [https://news.ycombinator.com/item?id=17638067](https://news.ycombinator.com/item?id=17638067)

</comment></comment><comment><USER25> 32\. I learned that humans can cry because their pet is dying. I cried because my best friend cat died (14 years R.I.P.) and it felt like it was my cat. I know it sounds stupid but this was a life lesson to me.

</comment><comment><USER26> 31\. In Java, this code can spin forever if a different thread changes this.done, and it's not a "volatile" member.

while(!this.done){ Thread.Sleep(1000); }

The more I learn about Java, the more I'm shocked at how mostly-identical it is to C#. Except C# is clearly superior in the details. I expected to find something java did better, but I'm coming up short.

<comment><USER27> One interesting article I read had an interesting point: one thing Java does better is to use type Erasure. This was surprising to me because reified types are often touted as one of the best things about C#. The author's argument was that type erasure made implementing different type systems on the JVM easier, because type erasure isn't as strict, which makes the JVM a more attractive language target than the CRT.

</comment></comment><comment><USER28> 31\. I just learned how to make soap in Dwarf Fortress.

<comment><USER29> 32 (and just learned about Competitive Analysis) but I wanted to say that learning how to make stuff in Dwarf Fortress is always rewarding in a very deep sense. I have no idea why, but every new mechanic mastered seems to multiply the possibilities of fun (and dwarf fortress 'fun' also)

</comment></comment><comment><USER30> 49, TIG welding for bicycle frames.

</comment><comment><USER31> 24, how to create a k8s cluster with kubeadm using cheap VPSs. Also, sea waves are more dangerous than I thought

<comment><USER32> How are you handling node additions and removals? Terraform?

<comment><USER33> Autoscaler([https://github.com/kubernetes/autoscaler/tree/master/cluster...](https://github.com/kubernetes/autoscaler/tree/master/cluster- autoscaler)) is a good option too. Works incredibly well at automatically adding/removing nodes based on workload.

</comment></comment></comment><comment><USER34> 53\. I'm learning to play the banjo and solve Rubik's cube. (I can solve it, but still need a cheat-sheet.)

I learned to juggle at 50. My plan is to try to stave off mental decline by learning new stuff.

</comment><comment><USER35> 70.17 years: Last big thing was the programming language Go, a few years ago.

        The last thing was differing opinions of Maimonides and Yehuda Halevi on primeval substances with regard to Creation Ex Nihilo.

        The very last thing was that the apartment next door is vacant and available for rent.

        The very very most recent thing is that I feel like answering this question.

</comment><comment><USER36> 31m, how important air conditioning is to my sanity.

</comment><comment><USER37> 35\. This has been going for a few years already but now I start to see some results: posing people for photography.

I know people which are quite good at it naturally, but at least for me it's a lot harder than learning a new programming language.

Learning something in which you're completely out of your comfort zone is even more rewarding.

</comment><comment><USER38> 30 - Yesterday, I learned how to make flask (python) web app.

<comment><USER39> Excellent choice.

</comment></comment><comment><USER40> 24 – I learnt how helping myself helps me help others. My body and mind are instruments and they require attention and maintenance.

On the tech side, I started learning Rust and delved deeper into how Perforce works so I could write a tool to backup and restore my pending changelists to/from Git repos.

</comment><comment><USER41> 21\. Just started going through the K&R text to learn C, it's definitely helped some aspects about programming that I didn't get in my Java courses. Also doing it exclusively in vim so I can practice typing and making sure I learn a lot of vim and terminal commands.

<comment><USER42> That sounds like an investment that will pay off in spades.

<comment><USER41> > Pay off in spades

What do you mean by that phrase?

Edit: Never mind, just took the time to search it.

</comment></comment></comment><comment><USER43> The average age of those who responded to this post is 38.6 (as of about 6:07pm UTC July 29)

<comment><USER22> Where's the std deviation? :)

<comment><USER13> If you're here you're definitely a deviant.

</comment></comment></comment><comment><USER44> 45\. Just learned how the vga's modex works after it being a mystery to me for 25 years.

</comment><comment><USER45> 31\. Polish. Still in progress and will probably take another couple of years.

</comment><comment><USER46> 39\. Class struggle and racism in America from its founding up to the present through a series of books a history post-doc friend assembled for me. "Going deep" on a topic as Tyler Cowen suggests.

<comment><USER22> I'd suggest you to take a look at what other "right" leaning people have to say about the subject. Especially Dinesh D Souza, Jordan Peterson, Ben Shapiro and Yaron Brook.

</comment></comment><comment><USER47> 32 - learned about place-items in css

</comment><comment><USER48> Age: 45

Last thing I learned? Err... well, on Friday I spent some time learning how to deploy tasks to Amazon ECS. I've also spent the last week or so doing a deep dive into OAuth and setting up a CAS server so I can use OAuth + Token Introspection for service-to-service authorization.

Additionally, I work with a quite diverse team (in terms of nationality / ethnicity) so I've been leaning on some co-workers to help me learn a few words of Portugese, Spanish, and Tamil here and there.

</comment><comment><USER49> 34\. Learning Economics. Reading Principles of Economics by N. Gregory Mankiw . I didn't take a course in Economics while in college and am trying to make up for it and build a better understanding of how the world operates.

I finished the Machine Learning specialization offered by UWash on Coursera a few months back, but I am not happy with my grasp on the subject and plan to dive deeper with a project and few books in next few months.

</comment><comment><USER50> 29

Recently moved to a new place (rented my own house and moved to a rented apartment), learned that nothing is permanent in life and less the expectations more the happiness

</comment><comment><USER51> 33, not the last thing I learned, but the last thing I put sustained long term (since December) effort to learn is sleight of hand and card magic in general. I went from knowing almost nothing about it to being able to perform multiple illusions and tricks, and being able to understand the mechanics of many magicians' routines that I see on television or YouTube. Still have a long way to go, though.

</comment><comment><USER52> 39\. Recently, I've read Dune again after having read it for the first time some 25 years ago. One notion I came across this time (probably did so back then, too but didn't attach much importance to it) and that particularly resonated with me was this - I'm paraphrasing here: Life is its own tool for ever more efficiently making use of the energy available within a system.

</comment><comment><USER53> 21\. i'm more capable than i give myself credit for, and i need to remember that. some days it feels like all i know is what i don't know

</comment><comment><USER54> Over 50. Just read Judith Shklar's _The Liberalism of Fear_ [https://philpapers.org/archive/SHKTLO.pdf](https://philpapers.org/archive/SHKTLO.pdf), which argues that minimizing fear is a valid political principle:

"Every adult should be able to make as many effective decisions without fear or favor about as many aspects of her or his life as is compatible with the like freedom of every other adult."

Further, "Apart from prohibiting interference with the freedom of others, liberalism does not have any particular positive doctrines about how people are to conduct their lives or what personal choices they are to make."

<comment><USER55> What if people's fears are generated or exaggerated by a unaccountable minority leveraging unregulated tools, mining illegal data mixed with psychology for profit, power or both?

</comment></comment><comment> 52-6F-62 31\. Germanium transistors perform inconsistently in different temperatures, and not necessarily to a fault.

Great thread subject, btw. This is interesting.

</comment><comment><USER55> 36 I'm way more distracted than I thought

I finished Cal Newport's Deep Work and even though I thought I could focus when I really needed to I realized that I'm kidding myself and I go to my phone habitually.

I've also stopped using slack/hipchat during a lot of the work day. When I get to the end of the day and see the hundreds of message counts it's quite shocking.

</comment><comment><USER56> 24\. Learned how to use multiple framebuffers in OpenGL (still working on how to get motion vectors right though).

</comment><comment><USER57> 29 - Learned how antenna tuning works for cellular, LoRa, GPS, etc. Still a dark art and im still a noob at it.

</comment><comment><USER58> 41, learned how useful Anki can be. Started using it recently. Also preparing for whiteboard interviews.

</comment><comment><USER59> 53 - How to change a bike tire and tube

</comment><comment><USER60> 34

1\. Learned swimming over the last 4-6 weeks

2\. Learning Spanish ( Duolingo / Pimsleur )

3\. Learned to live minimalisicaly for the last 15 months. ( includes international and domestic travel )

PS: I am also constantly learning new technologies in AI/ML/NLP/Alexa/Google Assistant/AWS/GCP etc as I find those fun :)

</comment><comment><USER61> 34\. How to build a HiFi tube amplifier

<comment><USER62> I've been thinking about stepping up my hobby electronics projects to further my knowledge, building a basic amp and DAC, I'd love to hear more about this.

<comment> 52-6F-62 I Second

</comment></comment></comment><comment><USER63> 35 - lately i've been learning about arcade machines. how they work, how to fix them, etc. Ive fixed two so far back to perfect working order. My next project is a small repair on a EM(electro mechanical) pinball machine from the 70s, kinda of excited about it.

</comment><comment><USER64> This thread helped to reduce my inferiority complex from reading HN, when I learnt that most of you are almost twice as old as me (20) and some even older than that :)

To answer OP question, I learnt a lot about Spring Test configuration today and how messy it can get at times.

</comment><comment><USER65> A couple months shy of 40.

It's harder to keep open two accounts on the same news site (one for myself, one for a short term gag account) and actually keep them straight without giving away the game. Mentally hard, not technically, since that's just two browsers.

</comment><comment><USER66> 50\. The very last thing I learned is that the language which gave us the original word for orange is now using the English word for it (yesterday).

The last completely new thing (for me) I learned was how to write a "hello world" program in Rust. ;-)

</comment><comment><USER67> 28, how to disassemble an engine in polo 2008.. just not to be ripped off by car mechanic

</comment><comment><USER68> 18\. I've been learning a lot about Drupal recently, and it's been really eye opening in terms of what PHP can actually do. I haven't taken a serious look at it in years and frankly writing tests in it has been really odd.

</comment><comment><USER69> I'm 34. I learned 5 new words in Hebrew via Anki this morning at 6:30am. I do this every morning as I increase my ability and go towards C1.

This doesn't include everything that I learned yesterday evening, per the requirements of the question.

</comment><comment><USER70> 23 yo

Last tech thing: learned how routers work

Last non-tech thing: some strategy in technique for amateur cycling racing

</comment><comment><USER71> 21\. Last thing I learnt was fixing my Android device's super annoying boot- loop.

<comment><USER72> I remember being 17 and doing that on the very day I got my first android phone! Decided to flash a custom ROM (CyanogenMod) without charging the device first and nearly bricked it, and forced me to learn how adb and device bootloaders work.

</comment></comment><comment><USER73> 26, I learned to swim effectively and effortlessly few weeks ago and still learning and practicing. And learned Android Architecture Components, Dependency Injection and Firebase as my profession is android developer.

</comment><comment><USER74> Realized that browsing second hand shops, flea markets, visiting museums, art galleries, trade shows, have a common theme and still make people happy even when they leave without buying anything.

</comment><comment><USER75> 30 --- Today I learned about Bee Venom Therapy:

[https://www.beeculture.com/bee-venom- therapy/](https://www.beeculture.com/bee-venom-therapy/)

</comment><comment><USER76> 24, how my daily habits (sitting, walking, ...) were the root cause of all my aches and how to adjust them to get rid of most aches. Still learning, but so far the results are incredible.

<comment><USER77> Interesting. How did you discover this?

</comment></comment><comment><USER78> 39\. Learned (and am still learning) how to brew beer. This is great.

<comment><USER79> Any good resources?

<comment><USER80> I learned to brew many years ago and have always liked this book:

How To Brew: Everything You Need to Know to Brew Great Beer Every Time [https://www.amazon.com/dp/1938469356/ref=cm_sw_r_cp_tai_JTFx...](https://www.amazon.com/dp/1938469356/ref=cm_sw_r_cp_tai_JTFxBbB9D5154)

This book is pretty commonly sold with starter kits too.

</comment></comment></comment><comment><USER81> 25, learned vim, went from 100% sublime to 100% vim in 6 months.

<comment><USER79> What are the differences and why do you prefer vim?

<comment><USER82> As someone who switched from sublime to vim after college (dev team was all sublime), I second the request for any benefits of vim over sublime (aside from being cooler). I've been wanting to relearn using it with fluency, but can't justify the time-sink/productivity loss yet.

</comment></comment></comment><comment><USER83> 63\. Docker. I have Plex, Wordpress, Nagios, SQL Server, Pihole, and VPN containers in a CentOS VM under Parallels on my Mac. It's been fun setting this up.

</comment><comment><USER84> 40, yesterday I opened a mechanical keyboard for the first time and learned how to disassemble and fix a cherry (outemu) mechanical switch.

</comment><comment><USER85> 46, and I learned how to use redis sentinel without having to integrate it into your code by leveraging haproxy to handle failover.

</comment><comment><USER86> 56\. how to ssh into an AWS instance. Oh the joy!

</comment><comment><USER87> 23, Handling asynchronous processing, requests to APIs and unit testing. Organization of code, how to structure projects.

</comment><comment><USER88> 25\. How to deploy a docker based lambda function to compile latex on fly. Currently it compiles tufte class pretty well.

<comment><USER89> I did the very same thing 2 weeks ago! Out of curiosity, were you using the lambci image as a starting point?

<comment><USER88> No, this one. [https://github.com/samoconnor/lambdalatex](https://github.com/samoconnor/lambdalatex)

<comment><USER89> They are using lambci as a starting point :)

[https://github.com/samoconnor/lambdalatex/blob/master/Docker...](https://github.com/samoconnor/lambdalatex/blob/master/Dockerfile#L1)

</comment></comment></comment></comment><comment><USER90> 27\. Don't hire painters from Handy.com.

</comment><comment><USER91> 27 - this morning I learned to apply gold leaf to wood. Most recently acquired skill - chip carving wood.

</comment><comment><USER92> 45, yesterday I learned how to fingerpick "don't think twice, it's alright" by bob Dylan on the ukulele.

</comment><comment><USER93> 52, currently building a house, finished the roof (ceramic tiles, angled buildout, valley gutters, etc).

</comment><comment><USER94> 41\. Connecting GatsbyJS to Wordpress. Awesome software, both of them. Learning about them now.

</comment><comment><USER95> 63 - PowerShell scripting. I think I learn some little thing almost every day.

</comment><comment><USER96> 27 - How to use a Film Camera (but also a lot about photography in general)

</comment><comment><USER72> 24\. Learned how IP Routing works while preparing to take the CCNA exam.

</comment><comment><USER97> 42\. Ground and tower comms related to pursuing private pilots license.

<comment><USER46> Private pilots's license was some of the best money and time I've spent on myself in my adult life. Enjoy!

</comment></comment><comment><USER98> 35, yesterday I learned how to play poker (texas hold'em)

<comment><USER92> Texas hold'em is life :)

<comment><USER99> I played Texas hold'em last week, and all of us hadn't played it in multiple years. It was pretty hilarious since we started from the assumption that "this ain't so complicated, we've done it before", but then debated for most of the time how blinds work.

</comment></comment></comment><comment><USER82> 26\. Tech: Scrollama (JavaScript library for scrollytelling).

</comment><comment><USER100> 38 - learned from wife that it's my fault my 2 year old pooed on the floor downstairs while I was in the shower upstairs because 2 year old was calling me even though wife was downstairs with 2 year old at the time.

<comment><USER35> And therefore you learned that wisdom can be most obscure.

</comment></comment><comment><USER101> 26, how to make Mexican tortillas from scratch at home

</comment><comment><USER102> 28 - how to layout webpages with flexbox and css grid

</comment><comment><USER103> 32\. Journey of a packet from NIC to the application.

</comment><comment><USER104> 54 - Cocoa and Objective-C (on a 2003 G4 iMac).

</comment><comment><USER105> I'm 33. Replace your timing belt on time.

</comment><comment><USER106> 30 - How to cook a perfect steak at home

</comment><comment><USER107> 41m, Swift protocol-oriented programming

</comment><comment><USER108> 35\. Stoicism.

</comment><comment><USER109> 26 - Walking 5 meters on slackline.

</comment><comment><USER110> 22 - How to write an Android app

</comment><comment><USER111> 27\. Kubernetes cronjobs

</comment><comment><USER112> 35.

1.5 mount and Buddha's revenge.

</comment><comment><USER113> 50\. Machine learning.

</comment><comment><USER114> 40\. Apache Spark

</comment><comment><USER115> 33\. Apache Arrow

</comment><comment><USER116> 24\. Tennis

</comment><comment><USER117> Why does age matter ? What is the point of asking about age ?

<comment><USER118> Not the OP, but I can be an interesting metric with regards to what people learn. For instance with regards to languages, do "younger" commenters learn more "hyped" languages than "older"? Or is the reverse?

In general I would classify it "just for fun" and the OP did state it was optional. Perhaps edited after your comment?

</comment></comment><comment><USER119> 41 - learning to trade options on the stock market.

<comment><USER120> Can anyone recommend a path to learning about investing?

<comment><USER13> The book, "The Intelligent Investor". Highly recommended by Warren Buffet and me.

</comment></comment></comment><comment><USER117> Why does age matter ? What is the point of asking how old a person is?

<comment><USER121> Lol they did say optional.</comment></comment>


Ask HN: When to launch your app? - <AUTHOR>

So I've often read that you should launch a product as soon as possible. Get it into the hands of your customers and iterate/iterate/iterate.
How do you determine what is the MVP of your product though?
My app for example, might already be able to do XYZ, but I'm still working on ABC which set it apart from the competition.
Personally I feel like ABC need to be done before I can launch, but it seems as though everything I read says to get it out once XYZ is functional.
If you've launched an app in a highly competitive space, how did you decided when to release your product? <comment><USER2> If your product can do XYZ, and XYZ fills a need in a genuine user, then get it to market now.

By the time you've finished ABC, you'll have existing users to sell to. Or you'll have learned things you don't right now about your market, without having sunk development time needlessly.

What's the worst that could happen if you launch today?</comment>


Dear Amazon interns, some advice from an old man who has been at Amazon too long - <AUTHOR> https://www.reddit.com/r/Seattle/comments/3ce0s8/dear_amazon_interns_some_advice_from_an_old_man/ <comment><USER2> Really this goes for a lot of big co.

<comment><USER3> There are lots of big companies with a great reputation for treating their employees well (e.g., Facebook, Google), but also plenty that grind them into the ground and spit them out. Apple, perhaps, being the most commonly referenced.

Reminds me of this, posted at some point here on HN: [http://roadlesstravelled.me/2015/04/06/why-steve-jobs- motiva...](http://roadlesstravelled.me/2015/04/06/why-steve-jobs-motivated-me- to-quit-apple/?utm_source=hackernewsletter&utm_medium=email&utm_term=fav)</comment></comment>


Elon Musk and Grimes are now parents to a new baby boy - <AUTHOR> https://www.cnet.com/news/elon-musk-and-grimes-are-now-parents-to-a-new-baby-boy/ <comment><USER2> dude is 6/6 boys, what's his secret?

</comment><comment><USER3> One more Musk.</comment>


LED, CFL and Incandescent bulbs side by side - <AUTHOR> http://news.cnet.com/2300-11128_3-10008853-4.html?tag=untagged

<comment><USER3> Isn't the issue really more about the quality of the light, which can't be captured in photos? CFLs give me headaches after a while, just like big florescent office-style lights.

<comment><USER4> In my personal experience, the difference between a crappy CFL and a good CFL is huge. Low-end CFLs are dim, flickery, have a large warm-up period and often worse color. High-end CFLs, on the other hand, can have really nice quality light, good color balance (though I used whiter "full-spectrum" incandescent bulbs, so YMMV), and very little in the way of noticeable warm-up time.

You may still dislike CFLs and that's fine, but you may also have just been exposed to crappy ones.

<comment><USER5> And it's important to mention that "high end" CFLs now cost about $1 each. You can get bulbs at Home Depot for $4 for a pack of four that turn on immediately, don't flicker, and are available in three color profiles including a warm one that looks very much like an incandescent.

<comment><USER6> Where LED is valuable for me is in the dimmable category. I have "dimmable" CFLs and they are terrible, they _barely_ dim and if you lower the dimmer too far they either blink or go off entirely. CFLs are just not dimmable.

<comment><USER7> Where LED is valuable for me is the absence of mercury. I break an incandescent bulb in my home at least twice a year.

</comment></comment></comment></comment></comment><comment><USER6> I could be wrong about this, but isn't it pointless to do side-by-side comparisons using a device that requires specific white balancing. A camera is not going to capture the same result your eyes will.

<comment><USER8> You can capture the relative difference and if you keep the same white balance setting (or, more likely, apply the same setting to the raw photograph in post) it's even possible to compare different photos.

What those photos likely can't tell you is what you would see if you were in the room. The brain does a lot of processing of its own.

<comment><USER6> I suppose it shows that the LED has similar color characteristics to incandescent.

<comment><USER8> Sure, the photo tells you that both would look very similar to your eye. It's certainly not an worthless exercise to compare with photos, I think everyone knows what incandescent light bulbs look like.

</comment></comment></comment></comment><comment><USER9> Am I the only one who prefers the cool white/blue of CFLs?

<comment><USER10> I prefer white light over soft yellow light :)

I read something a while ago about different cultures, and their preferences for different kinds of light. I believe North Americans tend to like the soft yellow, while many Asian cultures are more comfortable with crisp white. Although, I grew up here, so I'm not sure where my preference comes from.

<comment><USER11> I prefer soft yellow in most of the house and crisp white in the bathrooms and office. In bathrooms it allows you to see everything clearly (a good thing?) and in the office I find it keeps me alert.

<comment><USER12> My thoughts exactly. It depends on the room; yellow in living/dining, and white in bathroom/office.

I have a white CFL desklamp in my home office, and by a chair in the corner I have a yellow corner lamp (admittedly incandescent not LED).

I prefer to do casual reading/relaxing under yellow light ("mood lighting"), and work/bathroom under white light.

This may seem like a binary issue, but really it comes down to setting and personal preference for the light used therein.

"Find out what you want, and then learn to ask the right questions." - <USER2> Shalhoub, psychiatrist in 'How Do You Know' (random but memorable quote from the Paul Rudd romcom I relented to watch with my wife recently)

</comment></comment></comment></comment><comment><USER13> This is a useless comparison. What matters is whether the spectrum is filled out or not. It's easy to make an LED light with the same subjective color temperature as an incandescent, but which is really only emitting three wavelengths of light. This bulb will be missing most of the spectrum and it'll make colored objects look wrong.

</comment><comment><USER14> human skin looks better the more tinted toward orange/red you get. warm tones also make rooms feel cozy.

</comment><comment><USER15> Glad to see these are finally coming into mass retail. I think they may have missed an opportunity to make the colour output somewhat customizable. They could have included multiple plastic covers instead of only the yellow one.

<comment><USER16> That would probably add more expense than it's worth. The yellow part isn't just a plastic color filter, the lights use what's called a "remote phosphor", where it's internally using high powered blue LEDs, which is then absorbed and reemitted in a wider spectrum at the yellow layer.

There are a number of reasons for doing this, but the biggest ones are that it gives it a large and more diffuse emitting area, preventing the multiple shadows from exposed LEDs, and (IIRC) that the phosphors tend to be more stable when not integrated into the LED.

</comment></comment><comment><USER17> $40, though, really?

<comment><USER10> Worth it, stretched over like 7 years?

<comment><USER18> The LED's should last alot longer than that. The problem is going to be the switch-mode power supply. I'd hold off on these things until their price drops a bit, and until we have an idea how long the PS will last. Has anyone done a teardown on these yet?

The CFL's I've bought from Costco are lasting less than a year for me, so I'm reluctant to start using them until they have the bugs worked out.

<comment><USER19> Here you go: [http://www.edn.com/blog/PowerSource/40512-Remote_Phosphors_P...](http://www.edn.com/blog/PowerSource/40512-Remote_Phosphors_Philips_LED_bulb_Tear_down_Part_II.php)

Doesn't look like a high quality circuit to me.

<comment><USER18> Maybe it is the photo quality, but that main board looks almost hand-soldered instead of reflowed. The blobs on the SMT parts aren't consistent, although that may be because they have a mixture of through-hole parts so close.

<comment><USER19> My thoughts exactly. It looks like something that I would build by hand (messy) as opposed to something that comes out of a factory. I guess it doesn't necessarily mean that it will be unreliable, but I can't help but think so.

All would be forgiven if it wasn't $40. I was going to get a bunch of these, but at this price point it just doesn't make sense.

<comment><USER7> "All would be forgiven if it wasn't $40."

Early days.

</comment></comment></comment></comment></comment></comment></comment><comment><USER20> I see these have a yellow filter on the outside. That means they're throwing away light to get the right color. I think that's nuts, considering how hard it is to get that much light out of LEDs to begin with. I hope they make a version without the filter.

<comment><USER21> My understanding is that it's not so much a filter as a retransmitter layer. The LEDs give off a rather small spectrum of light that's quite harsh and the yellow "filter" takes that energy in and fluoresces out of a wide variety of wavelengths of light that are much more pleasant. There's most certainly a loss of energy because of the conversion, but it's not filtering out wavelengths like normal light filters do.

<comment><USER22> This is similar to what fluorescent lights do. If you've ever broken a fluorescent bulb, you'll notice a powdery coating on the inside of the glass, which is the phosphor coating that actually absorbs the violet/ultra-violet light of the excited mercury vapor and then re-emits it as visible light.

</comment></comment></comment><comment><USER23> Looking forward to the Switch company's LED bulbs. <http://switchlightbulbs.com/>

This was mentioned on HN a few weeks ago.</comment>


Idea for the structure of a tutoring site - <AUTHOR>

I don't have any real coding ability and I certainly don't have time for a side project but I was hoping to get some feedback on an idea of mine:<p>Upon visiting the site you would be asked to register as a student or as a tutor. Upon registering as a tutor you would select your areas of expertise and take a few diagnostic tests, perhaps pulled from khan academy and other sites. You would be encouraged to buy a low cost usb writing pad to assist you in your teaching, and you would agree to accept no payment for your first 20 or so tutoring sessions. This is because you would be proving your abilities as a tutor to students who had agreed to do sessions with tutors of unproven ability (this would also serve as the free pricing tier). After each session the student would rate the tutor in several categories, allowing them to build up credibility and desirability among the students. Once they are proven the students who would like a more professional experience can submit reasonable payments before their session through stripe or some other simple payment system. The sessions look like a split screen with a video feed of the other person on one side and a virtual paper display on the other. Tutors can log in and do sessions with available students whenever they want, or students can subscribe to specific tutors at given times if both parties agree. I can see this having a problem with an initial lack of tutors/users and also a library of diagnostic tests would be difficult to build up since this idea isn't limited to standard subjects. I'd love to hear HN's ideas on this, thanks for reading. <comment><USER2> Make a few mockups dude! Even if you can't code, use microsoft paint or whatever program you have - it'll help you clarify your own ideas of how the product will work, but more than that, it'll give the people here something more actionable to help you with!

I don't understand the "buy a low cost usb writing pad". Shouldn't be necessary. But other than that, anything in the tutor providing space sounds useful - there's a need there, and tons of companies trying to address it (study aid sites like notehall/cramster, course management platforms like piazza) that's more than enough validation to keep moving on it.</comment>


The Two Pillars of JavaScript: Part 1: How to Escape the 7th Circle of Hell - <AUTHOR> https://medium.com/javascript-scene/the-two-pillars-of-javascript-ee6f3281e7f3 <comment><USER3> Elliott certainly knows a lot about programming JavaScript, but reading his piece I have no way of knowing whether he knows a lot about programming in general, or architecture.

He tells us, again and again, that it's best to avoid trying to emulate inheritance in JavaScript, because that often goes horribly wrong - <USER2> JavaScript. I'm not sure it's valid to extrapolate his experience to outside JS. I get the impression he's teaching us how to avoid problems that we wouldn't have (or less so) if we weren't saddled with JS.

His enthusiasm for JS, meanwhile, seems a little misplaced. A language riddled with many horrible gotchas that inspired Mr. Crockford to write a book on how to avoid them? Why should we need to tiptoe around the fact that "this" means different things in different contexts? The "prototypal functions that happen to contain data" idiom is refreshingly different and interesting, but does it really offer advantages not found in "conventional" OOP or FP?

JS commands a huge following. But as Elliott hints at the beginning, its popularity is not a matter of choice. Netscape saddled us with a legacy where the API of every browser is necessarily JS. JS is the best language for programming browsers simply because it's the only one. That it's not a universal favorite is evidenced by the many projects that offer a "cross compile to JS" option. The users of those products would rather code in a different language.

All that said, a disclaimer: Though I've read _The Good Parts_ and other JS books, I avoid JS, I barely know JS, I have next to no experience with it and I suck at programming in it. So the foregoing is an opinion not backed by a wealth of knowledge and experience. I submit it as a kernel for discussion, hopefully by more knowledgeable people.

<comment><USER4> it's depressingly good at deployment though isn't it. there's nothing easier to "port". it's the write once run anywhere that's been promised so many times. i just don't feel like writing anything in it!

i don't think that this is a great article because there's a lot of bloat around the content to wade through and filter.

<comment><USER5> > it's the write once run anywhere that's been promised so many times.

It has yet to even obtain Java-level "write once, debug everywhere". Most of the people talking about "isomorphic JS" and "JS is everywhere" use, and expect, a single javascript VM implementation (V8).

<comment><USER4> i was under the impression that jQuery had taken care of that, perhaps i was mistaken. certainly a url is quicker to deploy than a jar.

with the exception of jQuery: i appreciate your point, even within the same browser, different js engine versions have wildly different behaviour.

</comment></comment></comment></comment><comment><USER6> I'd love to stop using 'new' and embrace a more basic, less side-effect-laden and ultimately more flexible way of creating and returning objects in Javascript, such as Object.create(), object literal plus setting __proto__, or whatever. Unfortunately, all of these methods are still massively slower than 'new' \- like, three to thirty times slower. (Sixty times, even, if you're on Safari!)

[http://jsperf.com/object-create-vs-crockford-vs-jorge-vs- con...](http://jsperf.com/object-create-vs-crockford-vs-jorge-vs- constructor/58)

Since he mentioned HTML5 games and trying to improve perfomance by avoiding the garbage collector, well, the above benchmarks are not the kind of thing you would want to compromise on either.

</comment><comment><USER7> The mantra "inheritance is the root of all evil" starts to bore me. Dot net framework is object oriented and uses inheritance. Java core API / standard lib is object oriented and uses inheritance. Every single iOS framework is object oriented and uses inheritance ( the ones written in Objective C at least). Android api are object oriented and use inheritance. Even Operating systems have been built with object oriented designs from scratch and ended up working quite well ( BeOS).

So please, next time you say that it's impossible to build anything big and reliable with this design because _YOU or people you know_ ended up in a mess, think again whether the problem really comes from the language, or the people.

<comment><USER8> I think there is a difference in inheriting from an abstract interface and constructing deep inheritance trees. The former is great in .Net for e.g constructing iterable collections and as such are more like glue between the language syntax and a concise implementation.

Deep inheritance trees, on the other hand, are difficult to use beautifully but yet are often portrayed as a first class design pattern which often ends up in mess. A priori designed inheritance trees without experience how such designs evolve in production are probably one of the biggest issues, I would imagine.

I think deep inheritance is an expert design tool that is easy to get wrong... therefore I kinda agree that the first advice "don't use it" is not misplaced but should be probably followed with "unless you really know you need it".

Since Javascript is a dynamic language it is easy for me to imagine deep inheritance trees will lead there to a terrible mess quickly since there is no static type system to enforce the design constraints.

<comment><USER9> I think people make mistakes in the architectural design part, often attempting to object-orient things that are not related in the strict way inheritance implies.

So, put more simply, don't make an Animal class if you have a Cow and a Tree, or you might end up treating legs and trunks the same. It should be no surprise, then, that bad things happen.

This is not the fault of the concept of inheritance, it is a fault in your thought process and the resulting design.

</comment></comment></comment><comment><USER10> I'm honestly really confused by this article, and would love if someone could clarify this for me (no pun intended). The author mentions that classical inheritance is to be avoided and prototypal inheritance is one of the language's best features. Then he goes on to state that the _constructor_ pattern is also to be avoided and suggests that this is something people use in an attempt to use JS in an object-oriented way.

Correct, me if I'm wrong, but using the constructor pattern (and new) in Javascript is the only real way to create an object that has a prototypal link to the constructor function's prototype. So what does this have to do with classical inheritance?

<comment><USER11> You can also use Object.create, __proto__ setter or a custom abstraction. However the constructor pattern is in practice used everywhere and I find nothing wrong with it, in fact in the next language version it will get first class syntax through the `class` construct. People need to accept that same keywords mean different things in different languages, just because Javascript `this` and `new` are not like Java `this` and new` doesn't make it better or worse.

<comment><USER10> Ok, but wouldn't Object.create be more useful for when you _are_ trying to shoehorn classical inheritance into Javascript? I still don't understand why he's implying (if I'm reading correctly) that using constructors is bad because you end up with the gorilla-holding-banana-and-forest problem that (he argues) comes with classical inheritance.

<comment><USER12> That gorilla-holding-banana-and-forest problem is more of a boogeyman than anything.

</comment></comment></comment></comment><comment><USER13> Wait, what? What decent programmer will ever find herself with N slightly different copies of their classes instead of planning ahead or doing some basic refactoring?

<comment><USER14> " _planning ahead_ "

Whoa, that's fighting talk. Next we'll be doing big design up front and (god forbid) beginning with the end in mind.

That was tongue-in-cheek, only because everywhere I go these days I see people bowing down at the altar of refactoring, rather than doing a bit of planning and getting it right first time.

<comment><USER15> Of course - planning is anti-"agile". You're supposed to run around in a constant state of chaos beating on everything with a hammer until a usable product magically pops out.

</comment></comment></comment><comment><USER16> This is missing some code examples. I just want to know what to use instead of constructors.

</comment><comment><USER17> "If you put the frog in cool water and gradually increase the heat, the frog will boil to death because it doesn't sense the danger. In this story, we are the frogs."

Indeed. And the fire IS Javascript...

The beginning of the article reads like care instructions someone would leave for the person they hired to babysit their pet velociraptor. "Now, here are all the things you shouldn't do or else Rapty will literally rip your face off"

</comment><comment><USER18> A praise of 'prototypal inheritance' in 2014? Doesn't sound like an escape from JavaScript hell.

<comment><USER19> I've been writing JS for a few months, after years of hating it from a distance. I must say it's not as bad as I expected, inasmuch as you can basically pretend it's a somewhat wonky Scheme.

The nicest part of it is the built-in hash table type and the related syntactic sugar that everyone for whatever reasons insists on calling "object".

One thing that makes me freeze right up, though, is I hear they're adding classes and inheritance and that whole OO clusterfuck to what's a nice, trim little dynamic language.

Like the article, I think it's possible to write good code in JS as it is, by accepting what it is, rather than trying to force it to be an OO language, by emulation or extension.

<comment><USER20> >The nicest part of it is the built-in hash table type and the related syntactic sugar that everyone for whatever reasons insists on calling "object".

People call it an object because that is what it is. If your code is using Javascript objects as general purpose hash tables with the normal syntactic sugar then your code is broken[1]. The correct way to use an object as a hash table involves a bunch of ugly extra syntax that makes it more verbose than hash tables in any other language I'm aware of.

[1] [http://www.devthought.com/2012/01/18/an-object-is-not-a- hash...](http://www.devthought.com/2012/01/18/an-object-is-not-a-hash/)

<comment><USER21> Object.create(null) creates an empty object with no prototype that you can safely use as a hash, as mentioned in the article you linked.

</comment></comment></comment></comment><comment><USER22> I was already expecting he'd talk about favoring composition over inheritance 1/3 the way into the article... which he finally does in the 40 minute+ videos after the end of the whole article.

There're a lot more problems with JavaScript than that. It's not even the most important problem IMHO.

</comment><comment><USER23> Javascript is a great language, and people who hate on it are very often just mindlessly repeating what they heard somewhere.

A person I used to work with liked to hate on js constantly. Then I looked at his code. He was trying to write js like it was java, because that was his background! If I wrote js like that, then I would hate it too.

If you don't know the fundamental concepts of a language, then you are clearly not in a position to take advantage of it's built in characteristics. Different languages have different "natural logical patterns" that take advantage of that languages design choices. By learning these patterns in one language, then when working in a different language if you get stuck you will have them available.

This article makes the point that you should avoid trying to do standard OOP in js, and I would generalize this idea as follows:

Every programming language has its own unique attributes, conventions, patterns, etc... when working in a new language, it's important to learn how to write _in that language 's style_, instead of imposing a different languages style.

</comment><comment><USER24> "What you think is a tool is actually a footgun" This man has a way with words.

</comment><comment><USER25> If you're interested in some actual code, take a look at this stampit library[1] on github.

[1] [https://github.com/ericelliott/stampit](https://github.com/ericelliott/stampit)

</comment><comment><USER26> [https://news.ycombinator.com/item?id=8538793](https://news.ycombinator.com/item?id=8538793)

</comment><comment><USER27> If JavaScript was so simple that we could force it into a singular model of ontology and be done with it once and for all, we would be so simple we could not.

Simply put, prototypical methodology reflects the mutability of reality. Object-oriented methodology reflects a visualization of reality.</comment>


Show HN: Fun new web game/app for mixologists - <AUTHOR>

I submitted this a few days ago, but it was a terrible time of day and recieved 0 feedback... sorry for the repost, but I'm really hoping for some input!
To teach myself Python and GAE, I recently made a new web game/app to help people learn how to bartend. I'm pretty happy with the results, and it was tons of fun to make. I currently can't make any changes to the app, as it is an entry in Mozilla's GameOn 2010 challenge (gaming.mozillalabs.com).
Any and all comments and suggestions would be appreciated though! www.drunkenweb.com <comment><USER2> I clicked it yesterday, then gave up before even completing the first round because I don't know anything about mixed drinks. This time I stuck it through a whole round, guessing blindly most of the time.

It's kind of a long game to just take a stab at. A practice round where you could get immediate feedback after just one patron would be nice in my opinion. That way I could see how I was being scored, instead of waiting until the end.

<comment><AUTHOR> That's a good idea.... Do you think having just a 1 or 2 patron round with some kind of 'tour' aspect (like walk-through help bubbles or something of the sort) would make it easier?

Also, do you think that the user interface contributed to your leaving during a round, or just the fact that you were heading through blindly?

Appreciate the feedback!

<comment><USER2> Yes, that's exactly what I mean by a practice round.

The only interface problem I had was distinguishing if I had selected a glass. If you could make it more clear that something has been selected that would be helpful. I didn't notice that at first and clicked it multiple times before I looked closely enough to realize it had been selected already. I'm not knowledgeable enough to reasonably succeed in the game, so it didn't seem that interesting, which is why I left originally. Targeting a specific, more interested audience would help, like maybe on a bartending forum, or bar building community, or something? Also, with all the bartop games I've been seeing pop up in bars and clubs, it would be a logical game to play there.

</comment></comment></comment><comment><AUTHOR> for your viewing pleasure: <http://www.drunkenweb.com>

Blog with some background and learnings from DrunkenWeb: <http://ecaroth.posterous.com/></comment>


Distributed Bug Tracking - <AUTHOR> http://sny.no/2014/04/dbts

<comment><USER2> There's a large number of dead projects in the distributed bug tracking field. There's a few live ones as well. See [http://travisbrown.ca/blog.html#TooMuchAboutDistributedBugTr...](http://travisbrown.ca/blog.html#TooMuchAboutDistributedBugTracking2013-04-20) for my summary of the situation.

I think distributed bug tracking hasn't caught on in the same way distributed version control has because while distributed version control depends only on how individual programmers work, distributed bug tracking depends on the organization of the entire project.

If you look at companies which develop software there are obvious workflow advantages to a DVCS, but it's still a centralized management structure which demands uniform visibility and control over the work the employees are doing. This is a case which argues against distributed bug tracking done in the same fashion as a DVCS, though just like a DVCS it can be used in a centralized manner which merely makes bug tracking faster for the developer.

If you look at open source projects many of them might have a bug tracker, but it's mostly a place where user bugs go to die. Much more typical with herding the volunteers cats is that the mailing list is the prime place to try to win developers over to fix your bug. If you don't succeed then you can try again later, but it might just be that the developers decided that your issue isn't worth solving. In such organizations a bug tracker won't get used anyway, so why bother figuring out distributed bug tracking?

Distributed bug tracking is a good fit with small projects because it reduces the necessary infrastructure. It can be made to work in other project types, but it's less obviously a win there.

</comment><comment><USER3> Nothing new. There are already implementations of such trackers, like ticgit, SD (App::SD on CPAN), Bugs Everywhere or ditz. Heck, they were included in Debian Squeeze three years ago, and Debian is not known for jumping on every new shiny thing!</comment>


Show HN: Simple Blogging Platform – QuickPublisher v1.3 - <AUTHOR> https://www.quickpublisher.online/features <comment><AUTHOR> Hi everyone. I posted my platform, QuickPublisher few weeks ago on SHOWHN. I got important feedback. I updated the platform with interesting changes:

Design your articles and custom pages with either Markdown or the famous WYSIWYG editor

RSS Feed

Post Scheduling

Comment Moderation

Improved speed (now 0.2 -1.0 seconds)

Display the total number of article views on your landing page</comment>


Understanding Data Transfer in AWS (infographic) - <AUTHOR> https://www.lastweekinaws.com/blog/understanding-data-transfer-in-aws/ <comment><USER2> This is a cool graphic.

Aside, if you are working in AWS and don't know about the AWS Open Guides (what this was based on), you should check them out: [https://github.com/open- guides/og-aws](https://github.com/open-guides/og-aws)

<comment><USER3> Fun fact: I'm the Community Lead for the Open Guide to AWS. The last revision of that transfer guide was my work as well. :-)

It's time for a new one, but only so many hours in the day...

</comment></comment><comment><USER4> Last Week in AWS is a fantastic mailing list to sign up for. Corey Quinn puts out great content week over week in a not-over-the-top yet cheeky style. One of the few useful things hitting my inbox weekly. If you're at all interested in keeping up with AWS I'd highly recommend.

<comment><USER3> Thank you--I wondered where the sudden spike in sign-ups came from yesterday!

Fun fact: you can hit reply to the newsletter and it lands in my inbox. Reader feedback is always welcome.

</comment></comment><comment><USER5> > Even data wants to get out of Ohio.

Is this a dig at us-east-2, or just Ohio generally?

<comment><USER6> Sounded like a dig at the state to me

<comment><USER3> Indeed.</comment></comment></comment>


Scala moving to Github - <AUTHOR> https://github.com/scala/scala/wiki/Github-Move

<comment><USER2> I sure hope this doesn't mean a move away from release formalism.

Github -- due in large part to complex social cues around encouraging public forking in a top-level namespace -- seems to encourage the assumption that developers will track git and add their own local patches, resulting in a significant decrease in upstream-interest in producing stable, formal, documented, tested, trustable releases and release builds.

<comment><USER3> Managing open source projects is difficult, and I too hope the quality and sensibility of releases doesn't degrade. But, Github might make the process more social, and easier to manage. More local patches could translate to more upstream patches.

<comment><USER4> > But, Github might make the process more social, and easier to manage. More > local patches could translate to more upstream patches.

I hope it does. However, when Clojure switched to github, basically nothing changed. The only difference was that changes showed up immediately instead of having to wait for the cron job that ran git-svn. They still only accept patches as attachments to Jira issues.

So it totally depends on the maintainers attitude. If they are switching because they're tired of everyone bugging them about it, then you probably won't see much change. If they're switching because they see compelling benefits to a process that allows more community involvement, then you might be in luck.

</comment></comment></comment><comment><USER5> Now it will be easier to keep updated to the source. I can't wait to look inside the source on the nightly builds just to see the what and why of things first hand.

</comment><comment><USER6> Finally!</comment>


How an anti ad-blocker works: Reverse-engineering BlockAdBlock - <AUTHOR> https://xy2.dev/article/re-bab/ <comment><USER2> Very nice writeup. I ran into a few sites last year that used this and attempted to reverse engineer it myself. I failed miserably because I know nothing about code in the browser, but for some reason it really piqued my interest.

The question that kept coming up for me is, will the arms race ever end? Are we doomed to the fate that consoles had where the entire device is locked down?

<comment><USER3> I am reasonably certain that it won't be long until ad-blocking becomes a whole different ballgame. Ublock will become an ever-updated trained model which real-time blocks ads. I have always wanted ad-blocking smart-glasses. The browser soon won't be any different. See Minority Report for an idea of where ads are headed (and then think about how to counter-act that, voila, that's how things will be)

</comment></comment><comment><USER4> This is interesting, especially begs the question whether Apple or Google browsers that no longer allow anything more than filter lists would be able to defeat sophisticated anti AdBlock attempts.</comment>


A Brief History of Email Apps - <AUTHOR> http://email-apps-timeline.missiveapp.com/ <comment><USER2> Email is very useful but does not make money. Salesforce, which is probably easier to execute as a product than Gmail, makes much more money with fewer users.

It's not surprising that they die off all the time as there is no way to monetize them.

<comment><AUTHOR> Timeline author here.

History seems to prove your point. At Missive, we add features on top of emails (collaboration). Our goal is to create enough value to justify a per user monthly fee.

<comment><USER3> how does Missive compare to Front?</comment></comment></comment>


The Drug Epidemic Among Older People - <AUTHOR> https://www.nytimes.com/2019/12/16/well/live/the-hidden-drug-epidemic-among-older-people.html <comment><USER2> Great article that highlights a social issue that is not receiving amount airway.</comment>


On the pleasures of stumbling upon books in the wrong places - <AUTHOR> https://www.theparisreview.org/blog/2017/10/17/happy-accidents/ <comment><USER2> There's a street in Bangalore where people sell old books by weight[1]. Usually, it's full of old cheap textbooks sold off by students, outdated magazines (like Readers Digest) and such. I spent a cool day walking through, random sampling the piles of books and found a copy of PG's On Lisp in mint condition.

[1] [https://www.google.co.in/search?tbm=isch&q=avenue+road+Banga...](https://www.google.co.in/search?tbm=isch&q=avenue+road+Bangalore&tbs=imgo:1&gws_rd=cr&dcr=0&ei=exDnWfyuB4jivASxrp3QBQ)

</comment><comment><USER3> I found a battered copy of 1984 in a school hallway once. At the time I hate books because I mostly read the ones we were taught in English class, which were mostly Hardy Boy-esque type books so I all books were like that. After reading 1984 I realized what books actually were and I've been an avid reader since then. I have a bookshelf filled with books, and then when I run out of space I'm filling up the floor around it with books. And I still have that worn copy of 1984.

</comment><comment><USER4> On one of my trips, I bought a number of copies of a few books and left them in random places as I drove, more or less randomly, around the country.

I put an email address in each one, along with a quick note. I got exactly one response.

I left copies of:

Ishmael; Another Roadside Attraction; Zen and the Art of Motorcycle Maintanence; Hitchhiker's Guide to the Galaxy; Battle Cry

(the formatting kinda sucks)

A dozen copies of each, except Ishmael which I bought the half dozen I found at a bookstore along the way and added those to my random seeding of books.

I hope they were placed in the right places and at the right times, but I only got one reply so maybe not.

<comment><USER5> This is an interesting idea. I came across a copy of "When Harlie was One" in a geocache while backpacking once. I would have loved to contact the person who put it there to ask them what they were thinking :-)

<comment><USER4> Yeah, I tend to just get up and go on long journeys. I try to make them mean something more than just engaging in wanderlust. It has given me the chance to see the world and meet many, many people.

I wish I'd more replies from my book seeding but it serves to demonstrate that what I thought was sheer brilliance really wasn't seen as such by others. It's humbling but not without reward in and of itself.

Those were all books that had impacted me in some way. I left personalized notes in each one, as well as the email address. So, to answer what I was thinking, I was thinking that I'd share something that had been meaningful to me, in some vain hope of similitude. I guess it was more about the hope of a shared experience, even if remote and unknown.

</comment></comment></comment><comment><USER6> I found an old SciFi anthology book as an early teen, I think in a bargain bucket at a Woolworths, called "Adventures in Tomorrow" it contained various short stories set at varying eras in the future, many by authors who went on to be quite famous... I mentioned this to my wife when I was 50 and she found an original hardback for pennies on Amazon Marketplace and it has re-kindled an enjoyment of fantasy writing that I had all but forgotten due to my incessant reading of manuals and factual texts... I must put aside more time for reading purely for enjoyment!

</comment><comment><USER7> I once found Hannah Arendt's "Ursprünge und Elemente totalitärer Herrschaft" in the street (in a small box with books). With newspaper clippings about her between the back pages... a book I had been meaning and then forgetting to read for 1-2 years before that. I still don't know whether I am more shocked that I found it or that someone put it in the street like that. But since then I always examine such boxes of books, and I'm finding more books I find interesting than I have time to read. I just love the randomness of it.

</comment><comment><USER8> This just happened to me yesterday, at the library. I was walking around, not looking for anything in particular. I found the most amazing book and read through almost half of it before I ordered it on amazon and a few others by the same author. I also vowed to donate money to the library when I'm rich.

<comment><USER9> What was the book?

</comment></comment><comment><USER10> I'm a book-lover and have a wall full of books i've collected over 25+yrs. Yet all I could think of reading this -- Breaking Bad.

</comment><comment><USER11> A diary entry published in the Paris Review. There's not much about books there, but there is a whole lot of I.

<comment><USER12> It's a blog post

<comment><USER11> It's the story of one person who found one book, which is very different and much less interesting than the title suggests.

</comment></comment></comment><comment><USER13> Librarian here. There is no pleasure of stumbling upon a book in the wrong place.

<comment><USER14> As a _library user_ it's a pet peeve of mine. If I ever see a book in wrong place, I just put it back where it belongs. There's noting more infuriating than not finding a book and knowing it's somewhere in there.

<comment><USER15> > If I ever see a book in wrong place, I just put it back where it belongs.

A lot of university libraries clearly instruct users not to put books back after taking them off the shelf, because in putting it back "in the right place", they often get it wrong. Instead, one should put it in a designated place for the library staff to shelve it instead.

<comment><USER16> Some libraries supposedly collect statistics on books used in the building, measured by counting books in the to-be-reshelved area, for use when lobbying for funding.</comment></comment></comment></comment>


Show HN: Tailwind Starter Kit – Free and Open Source UI for TailwindCSS - <AUTHOR> https://www.creative-tim.com/learning-lab/tailwind-starter-kit/#/presentation <comment><AUTHOR> Hey guys, this is our first Starter Kit based on TailwindCSS. If you have any feedback, ideas or improvements, please let us know.

Github repo here for contribution: [https://github.com/creativetimofficial/tailwind-starter- kit](https://github.com/creativetimofficial/tailwind-starter-kit) Documentation here: [https://www.creative-tim.com/learning-lab/tailwind- starter-k...](https://www.creative-tim.com/learning-lab/tailwind-starter- kit/#/documentation/download)

Thank you!

<comment><USER2> Any plans for Svelte? Also there is an overflow issue on mobile (popovers page). The landing page rocket icon on mobile needs additional margin on top.

<comment><AUTHOR> I will talk with my team about Svelte and see if we will release something in 2020. Thank you for the issue, noted, we will fix it :D Happy new Year!</comment></comment></comment>


How to publish an irrevocable prediction or pledge? - <AUTHOR> Let's suppose that I'm making a prediction or pledge today concerning some event in the future, for example: A human will walk on Mars before 2025. How should I publish it so that it will be easy to check for anyone what I predicted and when. More specifically:
* A predictor is identified by their e-mail address. It is assumed that a predictor has full and sole control of an e-mail address: only they can receive e-mails. (E-mail addresses can be also tied to identities on keybase.io, but that's beyond the scope of the question.)
* A predictor can submit a short prediction of a few words, about once a day. When making a prediction, (email, timestamp, text) is saved, and will be displayed in subsequent lookups. The timestamp is assigned by the server to the submit time.
* Predictions are public. There is a website where anybody can look up all predictions by e-mail address.
* The prediction database is append-only. It's not possible to edit or delete predictions after they were submitted. (It may be possible to comment on or to attach tags to existing predictions, but this is not a requirement.)
Is there an existing service or database (maybe a blockchain?) which could conveniently host predictions according to the requirements above?
One use case is following: I want to build a reputation of making many correct predictions and very few incorrect ones in a specific topic. Let's suppose that my e-mail address is well-known for people whose opinion I care about. I want to keep publishing predictions about once a week, and after a few years I want to make it easy for others to check what I predicted and when. It should be hard for me to cheat, e.g. by making both predictions (i.e. 1. Travel to Mars by 2025. 2. No travel to Mars by 2025.), and later deleting those which didn't come true. Thus Twitter is not a good solution, because I'm able to delete some of my tweets. <comment><USER2> I believe the "standard" method for this is to make a text file of your prediction + timestamps + whatever else, generate a hash (or hashes, I suppose), and publish them -- but this obviously requires you to keep the original text file around and safe until you want to reveal it.

I don't think there's any way of sealing a file such that it can only be opened at some future time (but cryptography always surprises me.)

<comment><AUTHOR> Sealing the prediction it is not requirement. All predictions are public as soon as they are published. It is a requirement though that a predictor shouldn't be able to publish contradicting predictions without easily being caught.

<comment><USER2> Ah, I see, I misunderstood! I guess a blockchain kind of thing is what you need then if the text is public? There was an immutable database on here the other week - [https://immudb.io](https://immudb.io) \- which might have some ideas.</comment></comment></comment>