Offshore wind will be a $1T industry by 2040, but it's needed now - <AUTHOR> https://www.utilitydive.com/news/offshore-wind-will-be-a-1t-industry-by-2040-but-our-oceans-and-economy-ne/567157/ <comment><USER2> By far the most wind turbines have been built on land and for good reason: it's much cheaper. As long as there is space/not too many people complaining it makes more sense to build on land. Not sure exactly but on land installed wind is probably ~10x the installed capacity offshore. However on land turbines are pretty much maxed out at about 7,5MW, due to logistical difficulties of getting larger blades, towers and nacelles transported over the road. These limitations don't apply to offshore sites, so the up-scaling continues. In the last few years typical offshore turbines have grown to about 9MW, but that is not the limit. Within a few years we should see 12-15MW turbines being installed, which should bring the cost down. Combined with the better wind conditions offshore (at least around the North Sea) offshore wind may become cheaper than expanding on land.

<comment><USER3> It was my impression that the main reason for building offshore is because the winds are much more steady there. The definition of trade wind is a "permanent prevailing wind"; building someplace with "permanent" winds sounds like a good idea to me.

<comment><USER4> Yes. Land based ones are often on plains or ridges. Steady and unimpeded wind is why aerial and offshore have better EROI.

<comment><USER5> Do land-based ones compete with agricultural usage?

<comment><USER6> No. In fact, they make marginal agricultural operations economically viable by providing a second source of income to the farmer/land owner.

</comment></comment></comment></comment></comment><comment><USER7> This is nuts. I wonder what the effect of spending $1T on nuclear would be in comparison. I bet it's enough money to get to practical nuclear fusion in a decade, which would largely obviate the need in most other energy generation methods.

<comment><USER8> It's going to take a lot more than $1T and a decade for fusion to be cost- competitive with wind and solar.

<comment><USER9> How are wind and solar cost-competitive when they can exist in Germany only with extreme high subsidies?

Look at the new windfarm called "Wikinger" that Germany built near the island of Ruegen: [https://de.wikipedia.org/wiki/Offshore- Windpark_Wikinger](https://de.wikipedia.org/wiki/Offshore-Windpark_Wikinger)

Cost: 1.4 billion Euros Lifetime: 20 years Power: 350 MW Max. capacity: 0.4 (40%) Price at the electricity stock exchange Leipzig: 36 Euro/MWh

Thus: 350 _0.4_ 24 _365_ 20*36 = 883 million Euros

Result: 517 million Euros loss

<comment><USER10> Why do you set a fixed price of 36 Euro / MWh for the next 20 years. At least take the phelix Futures to get a somewhat reasonable picture: [https://www.eex.com/en/market-data/power/futures/phelix- de-f...](https://www.eex.com/en/market-data/power/futures/phelix-de-futures) (45€ Base / 53€ Peak). With the EU-ETS Certs getting more an more sparse and expensive over time, coal will be phased out more and more which will increase the price.

<comment><USER7> Germany already has the highest power prices in Europe. How much higher can this really go?

</comment></comment></comment></comment></comment><comment><USER11> Probably the answer is a combination of wind, solar, and nuclear, but if we want to invest in wind, it has to be offshore.

The power output of a wind turbine is proportional to wind speed cubed and offshore wind is typically much stronger and more consistent than onshore wind. Probably we can take advantage of the expertise of oil and gas industry with offshore drilling to build offshore wind farms. Also it's safer for wild life.

The downside of offshore wind is the higher wear and tear of turbines. Last time I checked, composite delamination of turbine blades was still a problem. Also, it can be hard to recycle composites. Sometimes the only option is to literally burn them or use them as fillers in other products.

source: [https://www.npr.org/2019/09/10/759376113/unfurling-the- waste...](https://www.npr.org/2019/09/10/759376113/unfurling-the-waste- problem-caused-by-wind-energy)

</comment><comment><USER12> Oil and gas ("energy") companies are investing a lot into wind energy. They know they have to adopt. In the end they just want profits and they have the capital to make the right investments. I really wish the environmentalist movement saw them as just another money hungry corporation instead some evil villain out to destroy the planet. They would love to diversify their revenue stream, now is a good time to work with them because of the huge fossil fuel demand and the political pressure to wind down dependence on it.

On a separate note, I have two questions: why don't wind turbinea have more than one "wheel"? And does anyone know if ground tethered floating turbines (like airships) will be commercially viable?

<comment><USER13> > why don't wind turbines have more than one "wheel"

Which I take to mean more than one set of blades? In which case it's because they interfere with each other, and reduce the power generation possible in all surrounding turbines. Wind farms come with a minimum separation that is something like 5 or 10 blade diameters spacing, depending on prevailing winds. That spacing gives every turbine clear air free of induced eddy currents.

This is also why scaled down rooftop and urban wind generation doesn't really work - there are too many eddy currents such that generation becomes _very_ intermittent.

<comment><USER12> Thank you, first time learnig about eddy currents. Maybe the mobility of sea based turbines makes them a bit more attractive if they can move around to position themselves for maximum efficiency?

<comment><USER13> It's a similar effect to wake turbulence from large jets - invisible without added cloud or smoke, but can have a dramatic effect, so they space landings out well.

The offshore turbines I know of are in relatively shallow water, and fixed construction on the sea bed. Not sure if deep water turbines could move around, but I imagine the processing needed to calculate would be immense - fluid dynamics is pretty complex!

</comment></comment></comment></comment><comment><USER2> So disappointing journalists never understand the difference between power and energy. The opening sentences make me cringe so much I don't even want to read the rest of the article

> Last month the American wind industry hit a major milestone — 100 gigawatts > of total installed capacity. That's enough electricity to power the state of > California and New Jersey combined for one year.

<comment><USER14> What is wrong with that sentence? As of 2018 there was ~98k MW of installed wind capacity [1]. Reaching 100 GW of installed capacity in 2019 make perfect sense. It seems like it's you that doesn't understand the difference between power (watts) vs. energy (watt-hours / joules) yet are confident enough to call a journalist out even though they are correct.

[1]([https://gwec.net/wp-content/uploads/2019/04/GWEC-Global- Wind...](https://gwec.net/wp-content/uploads/2019/04/GWEC-Global-Wind- Report-2018.pdf)) Page 29

<comment><USER15> The sentence is literally correct, but misleading. A continuous 100GW might power those two states, but that's not what you get out of a 100GW wind installation. The capacity factor for wind is about 25-30%.

<comment><USER14> It isn't though. Thats how we talk about installed power capacity. The capacity factor is important but seperate. Nobody says we installed a 2.5 MW* wind turbine accounting for capacity factor. They say we installed a 10 MW wind turbine. It is assumed, especially given this publications audience, that the power factor is a seprate point. The person I replied to said that the sentance was so wrong it was "cringy" which is not true.

<comment><USER15> You've highlighted my essential issue with wind (and other renewables). Under the guise of "ah the dumb public won't understand", things like the actual expected output of a wind farm are hidden. It's a long enough road to renewable energy without hiding away the essential facts. The capacity factor, and resulting actual output of a wind farm, is the most important figure, along with its cost (which is a whole different debate).

Also, as has been pointed out, the loose use of terms for power and energy in the article is enough to make an engineer wince.

</comment></comment></comment></comment></comment><comment><USER16> How easy to maintain are these? Have they gotten better in the last decade? I see these things failing all the time around me but perhaps they are just shitty and better manufacturing saves the day?

<comment><USER17> > I see these things failing all the time around me

You do? Where?

<comment><USER18> I see dead ones at the San Gorgonio wind farm all the time. I imagine the maintenance situation is even worse for offshore installations.

<comment><USER19> Are they dead/broken or market optimizing power delivery?

Spinning a few down to nothing can be better for a farm total life time efficiency. You might make more money curtailing output because it is easy to turn off a wind turbine, compared to reacting with an inflexible baseload plant.

<comment><USER18> For many I can't tell the difference between off and broken, but some are clearly broken (missing blades, collapsed towers, etc). Supposedly a lot of the companies that were originally operating in the San Gorgonio pass went out of business, and their old windmills are being gradually replaced.

</comment></comment></comment></comment></comment><comment><USER20> how "stupid" would it be to turn all building roofs as solar surfaces and wind tunnels ?

<comment><USER11> What others said, plus the fact that most municipalities don't allow it. As a rule of thumb, the distance from a turbine to a permanent structure must be larger than the height of the turbine.

<comment><USER20> I meant tunnels not Mills though. Something flat.

<comment><USER11> My bad, but I'm curious; how do you generate power in a wind tunnel?

<comment><USER20> It's still fans but in arrays. Note that i'm no engineer, i just saw this somewhere and thought they'd fit nicely under Solar roofs.

</comment></comment></comment></comment></comment><comment><USER21> To me at least one trillion in culumative investment does not equal a one trillion dollar industry.

<comment><USER22> What does, then?

Isn't the "value" of an industry normally taken to be the sum of the market caps of all the companies in the industry?

<comment><USER23> Much of the time it will refer to revenue generated on an annual basis.

For example, all wind energy companies might spend $1T this year as an investment, but only bring in $10B in revenue. That would be a $10B market.

<comment><USER24> But manufacturing and installing wind turbines would be $1T/year revenue, since that's where their investment goes.

<comment><USER25> That would be $1T in cumulative revenue, not $1T/year of revenue.

It is a large number. But it's a different large number from the headline.

</comment></comment></comment></comment></comment><comment><USER26> no, we need more nuclear energy

</comment><comment><USER27> Will wind turbines accelerate climate change?

edit: during its exploitation

I was involved in design of Wind Farms and they affect wind directions at least locally. Naturally, they change climate locally. The question is how local is not global enough.

<comment><USER28> In terms of pulling out excess energy from the atmosphere then yes. But the effect will likely be too small to measure on a global scale. Note that the acceleration in here will be in the reverse direction. Plus the heat will eventually be re-released back into the atmosphere thanks to thermodynamics.

The majority of the savings will come from offsetting carbon emitting sources of power.

<comment><USER29> I'm curious about the environmental or ecological impact.

This is a pretty naive question but: will capturing that energy for human use divert it from other parts of the current ("natural") system where it's being used?

<comment><USER30> Energy wise, the orders of magnitude are quite different so I would not worry. After all, we are not worried about the direct heating from the much more prevalent source of electricity (waste heat from oil or nuclear), rather we are worried about the heating from the sun that is exacerbated by the accidental byproduct of burning oil.

Habitat destruction from these new technologies: no idea...

</comment></comment></comment></comment><comment><USER31> How many birds is it worth sacrificing to build huge wind turbine farms instead of compact nuclear reactors? Is the worst case of a Chernobyl or Fukushima worse than the expected case from square miles of spinning blades?

<comment><USER32> > _How many birds is it worth sacrificing to build huge wind turbine farms > instead of compact nuclear reactors?_

As many as it takes to keep even more birds being sacrificed to keep fossil fuel plants (and in particular coal) running longer. I certainly support nuclear for non-terrestrial-power reasons, but the fact of the matter is that it just doesn't have the free market power going for it that solar and wind do and thus I don't think it can be competitive fast enough. Solar and wind have enormously lower capex, enormously faster iteration, and avoid security, military, and geopolitics concerns that affect much of the global population. That in turn means they have a lot more raw scale potential too.

Nuclear has foot print advantages and many designs may have lower impact in other ways (though be careful, issues like where to dump heat can be significant such as a river getting too hot). More importantly in my mind, nuclear expertise will be necessary for space and they're important sources of very important isotopes. But on power alone I think their moment has probably passed. It'd be a very different story if we had internalized carbon emissions and had a Free Market in energy decades ago, but at this point I don't think bringing up nuclear as a contrast to renewables is very helpful or interesting on its own.

<comment><USER33> Solar and wind won't be the solution for the foreseeable future. The price of energy creation is good, but storage just isn't there. Consider a city like New York. How much solar power are you going to get in the winter when a big blizzard rolls through. Or how about Miami when a slow moving tropical storm comes through. You need to be able to store a more than a week's worth of energy for these huge cities. Nuclear is the only option.

<comment><USER34> Why is nuclear the only option? NYC just made a deal with Quebec to buy hydro power.

<comment><USER33> I feel like making people add every possible qualifier to what they say is counter-productive. How about this... Nuclear is the only universally viable carbon-free option that doesn't require the end user to be in a geographically ideal location.</comment></comment></comment></comment></comment>


Thousands of Threads and Blocking I/O (2008) [pdf] - <AUTHOR> https://www.mailinator.com/tymaPaulMultithreaded.pdf <comment><USER2> Vert.x ( [http://vertx.io/](http://vertx.io/) ) is an interesting point in this discussion that was released after the paper was written. It uses the async reactor pattern, but allows multiple reactors to run - 1 per CPU core. It also handles events and state so that each unit runs only within a single thread which completely eliminates the need to worry about threat synchronization. Basically a multithreaded node.js engine. Along with using javascript or Java8 lambdas and promises, it makes for very nice code.

The async style also allows for faster code in fairly typical web server cases. Consider a request that needs to do an HTTP lookup and 3 database calls. In a blocking I/O case, this needs a memory heavy thread and each I/O operation must be done sequentially even if we need the result from all 4 operations to give the result. With async I/O, we can send off all 4 operations without requiring the memory usage of a thread, and all 4 operations complete much faster as they run in parallel.

</comment><comment><USER3> Interesting all his graphs top out at 1000 threads. Wonder what they would look like if they went to 5000, or 50,000 threads.

<comment><USER4> 5k would be fine, 50k would not, with current hardware and JVM, based on my experience. The pain point again in my experience, is not any of the issues cited in that presentation, but rather that GC gets bound up in a wad eventually when you have large (>10k) numbers of threads in a JVM (and any reasonably complex application). This is because the object graph becomes highly interconnected through the Thread and associated TLS objects. YMMV of course. Definitely agree that the "async is fast" myth needs debunking, though.

<comment><USER5> Do you think 10 JVMs running 5k threads each would perform better? Assuming you have enough memory for such a setup...

<comment><USER4> Probably, but then you have to manage 10x the JVMs which is no picnic. Pick your poison. Better to re-write to not use zillions of threads.</comment></comment></comment></comment>


Why Object-Oriented Languages Need Tail Calls (2009) - <AUTHOR> http://www.eighty-twenty.org/2011/10/01/oo-tail-calls <comment><USER2> > implement a set

> don't use a hash table

> use the stack

> complain when language doesn't have tail call

wat</comment>


Peter Norvig: How Computers Learn [video] - <AUTHOR> https://www.youtube.com/watch?v=T1O3ikmTEdA&feature=youtu.be&t=1244 <comment><USER2> Peter Norvig is really an impressive teacher.

I have been doing his course "Design of computer programs" ([https://www.udacity.com/course/cs212](https://www.udacity.com/course/cs212)) and it really push me from basic/novice developer to intermediary.

He succeed to explain you things in a natural way. He seems to always start by the basic assumption. Working and thinking around any problems/surprises he/you encounter. So, you have the impression to discover things more than learning them.

<comment><USER3> I frequently and Highly recommend "Design of computer programs" to everyone I can. As an intermediate developer before taking it, I still recommend it. He is an amazing teacher I have learned considerably just from the way he explains and approaches problems.

Plus taking a class for free from the director of research at google :)

<comment><USER4> Google Schmoogle - Peter Norvig is a powerhouse name and Google gains in prestige for having Peter Norvig, not the other way around.

</comment></comment></comment><comment><USER5> Interesting...being the winner of a programming contest was a negative factor when they evaluated later performance at Google.

@1:11:50

<comment><USER6> Thanks... Was just about to send out an application today that mentions me quickly winning a contest. Probably there's lots of dumb stuff I'm putting on my applications that I think makes me look good, but is seen as very bad. Wish I had someone who knows these secret factors to run my applications by.

Makes me kind of upset that many employers and investors keep some of their favorite indicators totally secret, except for a few insiders that they share them with.

</comment></comment><comment><USER7> What was the book he recommends at the beginning? It is hard to make out. Also can anybody recommend their resources for machine learning or AI in general?

<comment><USER8> [http://aima.cs.berkeley.edu/](http://aima.cs.berkeley.edu/) is the book being held up by the fellow introducing him. (That page also has a collection of links to resources; not sure how up-to-date.)

</comment></comment><comment><USER9> It really starts at around 00:11:00</comment>


Ask HN: Would you use StackExchange chat if - <AUTHOR> ...if it was more prominent in the UI? I always forget that it is there.
I use a few programming Slack groups, but wish this global community was more active in the chat.
Right now there are 0 people in the data science chat.
I feel like this place could help offload beginner questions to keep question quality high. Maybe you would have to graduate from the chat to be able to post?
UPDATE: Hmm. I'll make a meta post. https://meta.stackoverflow.com/questions/396094/chat-as-a-means-to-field-beginner-questions-to-increase-post-quality <comment><USER2> Id use chat in GitHub</comment>


Facebook and OkCupid's psychological studies were illegal under Maryland law - <AUTHOR> http://www.washingtonpost.com/blogs/the-switch/wp/2014/09/23/facebook-and-okcupids-psychological-studies-were-illegal-under-maryland-law-professor-argues/

<comment><USER2> I could be misinformed, but it sounds like what OKCupid did was an extreme form of A/B testing - at least, that is how they defended the 'experiment' during an interview on NPR's TL,DR. If this is the case, this could set an interesting - and unfortunate - precedent.</comment>


It's Easy to Get Scammed on Venmo - <AUTHOR> http://www.slate.com/articles/business/moneybox/2015/09/venmo_scam_and_fraud_why_it_s_easy_to_get_ripped_off_through_the_mobile.single.html <comment><USER2> > Finally on Jan. 22, from Eran Kimchi, Venmo's head of fraud, whom Movassaghi > emailed directly in a final attempt to recover his money and alert the > company to what he saw as a dangerous and pervasive scam: "Venmo has a > complete understanding of the scam plot you fell victim to … there is > nothing Venmo can do to comfort you. … You made an innocent mistake, and you > paid for it."

That's certainly one way of dealing with your customers. Remind me not to touch Venmo again in the future.

<comment><USER3> The ellipses scattered through that quote hint that it's been sliced together from a larger statement to make the guy look more tone deaf.

</comment></comment><comment><USER4> If I understood correctly, the whole damn scam is only possible because this Venmo's terms of service prohibit something called "merchant transactions" and allow for reversing or cancelling transfers if they deem or someone reports a payment to fall in "merchant" category?

If so, then the problem is only a completely artificial one and made of mere policy decisions. Venmo could just act as a blind intermediary, no questions asked, completing any transactions once both parties have verified their intention to transfer money.

That's generally how banks work for at least any reasonable sums of money: I can send or receive thousands of euros to whoever and from whoever without worrying that the transfers might be cancelled by some vague policy. With tens of thousands, I'd have to ask my bank to lift the daily transfer cap beforehand, but still no questions asked. I assume that it goes in a relatively similar way in the USA.

Thus, any mobile money transfer service ought to be at least as trustworthy as that. There needs to be a point where the transaction is either complete or discarded, after which both parties can trust it. The service also shouldn't discriminate, it shouldn't matter if it's a private transfer or a merchant transfer. If they want the money they could sell transaction history imports for bookkeeping at a higher price to merchants or something.

Venmo could still do their instant transfer magic and add value there, but them considering whether a transfer is ok or not is akin to an internet service provider who would want to consider which web pages I can view before letting me download them.

<comment><USER5> Banks don't work the way you think, at least in the US. ACH transfers are slow (take a few days to complete), and often expensive. Up until 5 days later, they can be reversed even after both banks agree that they've happend if the sender decides that the payment was "erroneous."

The government can and does impose "some vague policy" on what you can and can't do with your money. If they decide that you have been "structuring" your payments to avoid triggering various reports being generated, that is considered a crime. So making several payments of 9,000 might be illegal even if you've done nothing wrong (you should have done 11,000 so that all the reports could be generated, didn't you know?)

Oh and by the way people can just take money from your account via ACH transfer if they have the correct numbers. You won't get any kind of confirmation, the bank just assumes that nobody would be unwise enough to make an ACH transfer without the consent of the other party. The US generally believes in insecure infrastructure and the 500-pound surveillance and police gorilla to keep everyone in line. It works surprisingly well, to be honest.

<comment><USER4> _Oh and by the way people can just take money from your account via ACH transfer if they have the correct numbers._

Is the ACH an internal network between banks or something that regular people could use, either directly online or by dropping wiring orders to some box in the bank? If the latter, it sounds so crazy I almost don't believe it. Where is ACH used and who actually uses it if it implies that your money could be just taken away by someone who knows your account number (and hopefully some other information that you wouldn't normally share anywhere) ?

<comment><USER6> [http://engineering.zenpayroll.com/how-ach-works-a- developer-...](http://engineering.zenpayroll.com/how-ach-works-a-developer- perspective-part-1/)

</comment></comment></comment></comment><comment><USER7> What I find interesting is that I don't know anyone here in Australia that uses these payment platforms. I wonder if that's because bank-to-bank transfers are so quick and easy these days? Most of the big banks even have ways of sending _cash_ to other people, to withdraw from any of that bank's ATMs with a code and no card.

Anyway, the issue Venmo has here is similar to what banks also have to deal with: in theory you can reverse a transaction before it's cleared when sending money between accounts. That said, it's quite a bit more difficult I'd assume, and perhaps a lot of people who would otherwise be happy with scamming those out of money on third-party systems would think twice about doing so when a bank is involved. Interesting stuff, and it seems most startups who try and break into these sorts of markets have to learn all the hard lessons the big companies did years ago, which sucks for consumers. On the other hand, the incumbents are usually so slow moving and painful, I applaud those who attempt it.

<comment><USER8> Same here in Austria. Bank transfers are free and instantaneous between customers of the same bank, and take one business day to other banks. And they are irreversible.

Nobody needs to use something like Venmo here.

<comment><USER9> But how to you get their ID? Venmo uses phone numbers/facebook which is why it's so easy.

In America you need a ~20 digit account and routing number and even then Im not sure how to do it through my bank.

<comment><USER8> You use the IBAN (International Bank Account Number), which is a 20 digit number that you find on your bank card (it's similar to a credit card number).

Sure, you can't just transfer money to someone's facebook account, but I guess that the inconvenience of having to ask people for their bank account number before you can send them money isn't really that big of a deal.

Especially considering that we are used to paying everything by bank transfer. Things like rent, utilities, parking tickets... any time you get a bill, there's a bank account number on it that you need to transfer the money to. And you just pay it online using the bank's website.

(For paying recurring bills, you can also grant a company permission for "direct debit" for your account, so you don't need to do anything. It sounds risky, but I've never had any fraudulent charges on my account)

</comment></comment></comment></comment><comment><USER10> >In summer 2012, Venmo was acquired by online payments platform Braintree, which was in turn bought out by PayPal in the fall of 2013.

Ah, that explains it. PayPal is a company that has no problems with stealing money from its own customers, so it's no surprise that they're perfectly happy being complicit in fraud.

</comment><comment><USER11> Basically - "We'd rather prioritize growth than fraud protection so we make it your problem."

</comment><comment><USER12> Silicon Valley egos at their finest: "Use our product so we can make billions of dollars, but fuck you otherwise." I use venmo with friends because of their network effect and it's convenient, but it sounds like internally they're a pretty shitty company to deal with.

</comment><comment><USER13> I'm curious if the folk who got scammed w/the e-ticket sales could have waited until the funds are literally in their bank account before they emailed them the tickets. Surely, it is a helluva lot easier to reverse some Venmo balance than it is for Venmo to pull money out of your bank account, so that they can refund a scammer.

I've never touched Venmo and now after this, never will touch Venmo and will make sure everyone who suggests it, read this prior to using it.

<comment><USER14> No, not really. The scammer can use a stolen Amex card to send payments. When the card is reported stolen and charges reversed, that goes all the way back to the user's bank account.

Would be silly of Venmo to do otherwise, as that would be an easy way for them to go out of business.

<comment><USER15> But why would the bank reverse the transaction? From venmo viewpoint it is quite clear why they would want to reverse it, because they have changed the credit to actual funds. However the bank probably would want to protect their customer, and instead let venmo to take the hit.

<comment><USER16> The bank would reverse it because it's unauthorized to their customer. Put the onus on the merchant.

</comment></comment></comment></comment><comment><USER17> Doesn't surprise me that they are owned by Paypal; I know many who have been scammed on Paypal and they have the same kind of nice and friendly policy; 'we don't care, kthnxbye'. I understand they cannot be in business if they wouldn't work like that, however why do they need to be bastards about it? Even if they cannot do anything to help you, they could be sorry for you or at least show some kind of humanity.

Also they don't really seem to work on fraud cases, at least not as far as I can discover; a friend who ran a website selling digital goods (but unique goods so he actually had to buy each himself so fraud was costing him money, not only making him less revenue like it could be if it was software or an ebook) was scammed by the same user a number of times and sure, Paypal cannot give my friend his money but it was very clear this user was a scammer, especially after doing it to one company a number of times and probably to more companies as well...

This seems the same case; if they see this scam happening, why do they still refund? They know it's a scam; that weird remark from Eran Kimchi even says so. So why not screw the scammer instead? The seller always ends up screwed with Paypal. No difference here.

<comment><USER18> These days I consider PayPal to be about as scummy as Western Union. If I can help it, I don't touch them with a ten foot pole.

</comment></comment><comment><USER19> Wow. This sounds like a terrible user experience.

Transactions in the US banking system aren't instant, so they fake the transactions and pretend like you actually received them. Then when the actual transaction fails, oops you're out of luck.

</comment><comment><USER20> I a big fan of venmo, but it's crazy that they don't make it clear that your venmo balance can we reversed. There should be a "pending balance."

Also they should make it more clear about which types of payments are acceptable (though this is more of a complaint about TOS in general).

<comment><USER21> That's a problem with PayPal in general. I got scammed once because someone paid for something of mine with a stolen account, and the money was removed from my account almost two months after the transaction. I was rather alarmed, because it was long past the date after which I could deposit the money into my bank account, so I assumed by then that it was "safe".

</comment></comment><comment><USER22> Wow, I use Venmo all the time, never even thought the TOS would have something like this in it. Now I only use it among friends I know well. And any craigslist type transaction I've always done strictly with cash only. But this is definitely good to know though. Venmo needs to make this clear and make the reversal process much more involved, it seems it'd be really easy to pull this scam off.

</comment><comment><USER23> Not sure I know enough to call Venmo unethical in their behavior. But there's definitely more than a few red flags here.

<comment><USER24> Well if you claim that something is a) instant and b) has already happened when it hasn't - you are knowingly deceiving your customers to make it look like you provide a service you really do not.

</comment></comment><comment><USER25> Huh. So what happens (is supposed to happen) to merchants in the event of a chargeback?

* Paypal purportedly credits sellers if the seller proves they shipped / sold something [1]

* Square does _not_ necessarily credit sellers and may pull funds from a bank account [1]. (May have changed since the article?)

* Visa protects merchants from fraud-related chargebacks if the online sale is "verified by Visa"[2]; if not, the merchant _may_ have to suffer the loss. In particular, if the card was physically present, the merchant seems to lose if they screw up any of the little details in the charging process.

* Amazon protects merchants if the transaction occurred according to their policy and the merchant can prove they shipped goods or delivered a service [3]. I imagine if you embed Amazon Payments into your site as it's intended and sell legal stuff, you're fully covered against fraudulent buyers.

So it looks like Venmo (and likely Snapcash) are unique in offering such little fraud protection. Probably due to how their User Agreement works (i.e. they're not meant for merchant selling at all). Also why they can offer no- charge transfer services.

What's probably happened here is that these new services lack regulation and thus have no requirement or incentive to inform users about the consequences of chargebacks. I hate to say we need more regulation, but for Eran Kimchi (Venmo head of fraud) to say "You made an innocent mistake, and you paid for it" is not an acceptable outcome; Venmo is definitely guilty of negligence here.

[1] [http://alexshvartsman.com/2014/02/11/screwed-by- square/](http://alexshvartsman.com/2014/02/11/screwed-by-square/)

[2] page 82 [http://usa.visa.com/download/merchants/chargeback- management...](http://usa.visa.com/download/merchants/chargeback-management- guidelines-for-visa-merchants.pdf)

[3] [https://payments.amazon.com/help?nodeId=73479#fdcp_how](https://payments.amazon.com/help?nodeId=73479#fdcp_how)

</comment><comment><USER26> While I do sympathize with the victims, Venmo protects sending money and so I'm totally okay with their policies. The people involved in transactions should be mutually trusted parties. Craigslist is a place where scams happen all the time. This activity is possible on many platforms, not just Venmo.

They do however need to work on customer support and transparency, but that's if what's being reported is even completely accurate. My entire network of family, friends, and colleagues all use Venmo and none of us have had any issues.

</comment><comment><USER27> >

Once you understand that, you can see why Venmo doesn't want users to make merchant transactions, by which it really means payments outside their networks of close acquaintances. ("Merchant transactions," Vaughan tells me, "is sort of the catchall for the things that we can't predefine.") The analogous real world example is that you wouldn't leave a pair of tickets in a mailbox just because someone sent you a note promising to drop off an envelope of cash at a later date.

Isn't that why you're using a PAYMENTS platform, and not a PROMISE NOTE platform? When you receive or send a payment on a PAYMENTS platform, that's not, and shouldn't be, equivalent to a note promising cash. It should be the cash.

Since it's not, is it not fraudulent to say that it is and pass it off as that?

</comment><comment><USER28> I'm seeing a lot of Venmo bashing here, but I think it's a great service and these people just used it wrong. Even with a 'merchant transaction', all you had to do was click 'Withdraw' so that the money was on the way to your bank account before sending the buyer whatever they got. I thought it was already pretty clear that a Venmo balance isn't real money yet, it's just Venmo showing you your potential balance if you want to withdraw.

I can see how they should make it more clear, but the people who got scammed were also not very well informed.

<comment><USER29> The first guy did exactly this, got confirmation, and had the money reversed out of his account.

</comment></comment><comment><USER30> I was surprised to learn that PayPal has 16,000 employees! If I'd had to guess, I would have said something around 1000.

I guess there is a lot of manual work involved in handling all those transactions and fraud attempts.

<comment><USER31> I'd wager that much of their workforce is engineering and integration support, in addition to the redundancy they purchased by buying companies like BrainTree.

Additionally, PayPal owns a massive amount of legacy code and APIs. There are plenty of con talks where PayPal describes how they were mired down in bureaucracy when updating a single line of code in Java (JSP) but managed to flip that overhead on its head by running a NodeJS stack on top of the JSP stack (and in some places replacing it).

</comment></comment><comment><USER32> Can someone explain to me the value added of such a service vs simply making a bank transfer from your bank's website?

<comment><USER26> Making a bank transfer isn't 'simple', at least relative to Venmo. This is a way of paying someone just like Paypal. Except, the UI is better and you can hook up to Facebook. Because 'everyone' has it (at least w/ my group of friends) it is very easy to pay each other for group events. I still intend on using it despite the scam situations that people find themselves in.

<comment><USER32> Well I need to set up a new account on that thing and give it my bank details. Then my counterparties have to provide me with their ID on that app which is pretty much the same as providing a bank account number. So I don't get the convenience aspect.

I see the value of paypal, which is to create a screen between me and a dodgy website which I am buying from. That website can't get my credit card number and therefore take further payments. But when I am making a payment to someone why should I need an app to protect me against fraud? So I don't get the security aspect either.

<comment><USER26> Here's my user flow. I sign up and connect w/ Facebook. I connect my bank account. Separately, my friend who I rarely see does the same thing w/ his Facebook account and bank account. A few months later we meet, I pay the full check and he Venmo's me 20$ for the meal w/ a few taps on his phone. He doesn't need to ask me anything. Because we're already Facebook friends, he has access to send me money.

I have Bank of America. For the same transaction to happen I would need my friend to sign into his bank account on a mobile phone, initiate a wire transfer from his checking account to my checking account, which requires me to provide him my checking account number and zipcode and full name.

And that's just a 1 on 1 transaction.

The most common use case is if I'm eating in a group of say... 6 people. Instead of splitting the bill 6 ways which many restaurants won't allow one person will front the bill. The rest of the group just "Venmo's" the person who fronted the bill whatever they owe. No exchange of account numbers, no asking for Paypal email address, none of that. The assumption is that everyone has Venmo and everyone's connected on Facebook. As long as those 2 facts are true (which is common for American millennials) the convenience is bar none.

<comment><USER33> I swear sometimes we need to step back and think about things from a general consumer perspective and not one of the analytical early adopter.

Most people wouldn't remember a number like a checking account number nor do they carry checks around with them. Venmo is simple and easy for them to send money to friends without having to log into a bank's shoddily designed website and figuring out how to transfer funds which is probably non-obvious in the first place.

</comment></comment></comment></comment></comment><comment><USER34> PayPal discovered early on that they're not really in the payments business, they're in the security business. Handling problems costs PayPal more than doing the money transfers. Although PayPal owns Venmo, that expertise doesn't seem to have been transferred.

</comment><comment><USER35> If I owe someone 20 bucks for dinner or something I don't mind using Venmo, but who in their right mind would exchange thousands of dollars with strangers over an app without considering the risks or consulting with their bank?

</comment><comment><USER36> Square Cash is my go to over Venmo. Transactions are credited straight to your debit card vs going to a balance and then having to cash out.

</comment><comment><USER37> How do they (=Venmo) not end up losing court cases over this?

</comment><comment><USER38> Venmo: You're SOL pal.

</comment><comment><USER9> This title (titled "Venmo Sammers" as of this comment) should be edited back to the original.

<comment><USER39> We shortened it because of the linkbait "you", or rather the even-more- linkbait "you don't". Take that out and you get "Venmo Scammers Know Something", which is redundant. Take out the redundancy and you get "Venmo Scammers".

Suggestions for a better title are welcome, as always, but don't forget that HN's rule is to use the original title _unless it is misleading or linkbait_.([https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html))

<comment><USER40> _Their_ original title was "It's Shockingly Easy to Get Scammed on Venmo" (it still pops up on google like that) but it seems they've decided 'shockingly' alone is not baity enough. But it's a decent title without it. The article is not so much about Venmo scammers but about how easy it is to get scammed on Venmo and how Venmo isn't going to help you.

<comment><USER39> Ok. That doesn't show up as a title to me, but it is a heading on the page, so we'll use it. Without the "shockingly", obviously.

<comment><USER40> Oh they just changed it, for whatever shocking reason. But Google (and, shockingly, every content-farm around) remember.

[http://i.imgur.com/OdLJRIy.png](http://i.imgur.com/OdLJRIy.png)

</comment></comment></comment></comment></comment><comment><USER41> Do people really pay 5K to go see a single Basketball game.

<comment><USER42> just $600 per, here

</comment></comment><comment><USER43> I didnt have the patience to read to the end but it seemed poorly written. How does the scam work exactly? Is it a technical loophole or something to do with the quoted policy?

<comment><USER26> Neither, really. You're technically not allowed to do business on Venmo. The intended use case is to send money to people you trust. If someone sends money they can always get that money back by claiming the recipient violated terms or something.

<comment><USER43> That's why I did not understand. Buying a ticket on Craigslist is business? Is it supposed to only be used for people who know each other?

<comment><USER26> The main use cases are for people who are Facebook friends. I really can't fault Venmo too much here because they only deal w/ money. To me, they technically did their job. They protected the people that send the money, not the people who receive.

If you use this platform for potentially sketchy transactions, I'd say it's on the user to protect themselves. When I sell anything on Craigslist, it's always cash only. Even then, there are no guarantees.</comment></comment></comment></comment>


How We're Doing Stats at Howdy - <AUTHOR> https://medium.com/why-not/how-we-re-doing-stats-at-howdy-2956f88115f6 <comment><USER2> I think this is useful for small teams trying to validate ideas and not wasting time doing so.

I think the biggest downfall in terms of dashboards is making things actionable and getting away from vanity metrics.

</comment><comment><USER3> Love this. Especially the part where you don't spend time building yet- another-dashboard page. Once you've settled on the graphs you want, you could then integrate them in your product admin directly if you want.

It sort of reminds me of feature requests for sorting/filtering/highlighting data in HTML tables -- instead of trying to rebuild a crappy version of Excel in a browser, just add an export to CSV button :)

</comment><comment><USER4> There's nothing about how you handle user authentication. Are all of the stats just open to the public?

<comment><USER5> I was wondering this as well, I would expect the get stat function probably also passes some secret key in its arguments.</comment></comment>


Ten More Things I Wish I'd Known About Bash - <AUTHOR> https://zwischenzugs.com/2018/01/21/ten-more-things-i-wish-id-known-about-bash/ <comment><USER2> The best bash (or any other shell) "trick" is to learn how to use GNU Readline. Once you understand that most shells and other commandline REPLs use it, you can leverage the same, consistent keyboard commands across all of them.

Ctrl+A/E to move to the beginning/end of a line, for instance; or Ctrl+K to kill from the point to the end of line; or Ctrl+R to search the input history; etc. etc.

Probably one of the best and most transferable skills if you use the commandline a lot.</comment>


TapChat is mobile IRC done right - <AUTHOR> http://codebutler.com/tapchat-is-mobile-irc-done-right

<comment><USER2> No it isn't.

\- The only way to stop receiving notifications is to uninstall the app, there is no disconnect/detach option.

\- It doesn't have support for identd (necessary for old ZNC bouncers, and for some bitlbee builds).

\- The UI is very young, not comfortable to use, no easy channel switchers, etc.

\- No buddy/friends list.

\- Install fails in "supported' nodejs versions, almost works only on v.0.8.0

\- Complete lack of settings, including what I said about the most basic thing, connecting/disconnecting.

I had a lot of hopes for this, I use IRC with a few servers and a personal IM gateway (bitlbee), and for now I'm using AndChat which is a very good Android client but the permanent connection makes the battery drain very fast.

After having trouble getting the server up (nodejs version and such), I had trouble setting up the servers to connect to, as the settings for creating a new server were different with those of editing the new server, and the password was not even remembered when creating one, so I had to put it again after creating it in the edit mode.

But still, no support for identd had me update ZNC and bitlbee to support only server password with "user:pass".

After I finally got it up, for the first few minutes it was a dream, notifications came very fast, the app was good looking. And then I tried detaching from the server, no way to do that, after I kill the process, notifications still came up, and after "logging off" from my server I would still get them!!!! only way to stop was uninstalling the App.

Which I did. Hopefully I'll reinstall it when these problems get fixed.

<comment><USER3> Hi again. We spoke about all this a few days ago. Sorry to hear you're disappointed with the app.

\- The only way to stop receiving notifications is to uninstall the app, there is no disconnect/detach option.

This is a reasonable request and is on my list.

\- It doesn't have support for identd (necessary for old ZNC bouncers, and for some bitlbee builds).

As I mentioned, you don't need "identd" for ZNC. TapChat supports password- protected servers and works just fine with ZNC.

\- The UI is very young, not comfortable to use, no easy channel switchers, etc. \- No buddy/friends list.

\- Install fails in "supported' nodejs versions, almost works only on v.0.8.0

There was an issue with certain versions of nodejs, this has been fixed.

\- Complete lack of settings, including what I said about the most basic thing, connecting/disconnecting.

You can connect/disconnect from IRC networks in Settings > Manage IRC Networks.

</comment></comment><comment><USER4> This has been supported with Colloquy on iOS for years — even using ZNC as the bouncer with the Colloquy plugin. I'm glad there's now a solution for Android that looks like it might be approaching the same awesomeness level!

More info: <http://colloquy.info/project/wiki/PushNotifications>

</comment><comment><USER5> I use irssi on the server with Irssi ConnectBot [https://play.google.com/store/apps/details?id=org.woltage.ir...](https://play.google.com/store/apps/details?id=org.woltage.irssiconnectbot) and Hacker's Keyboard [https://play.google.com/store/apps/details?id=org.pocketwork...](https://play.google.com/store/apps/details?id=org.pocketworkstation.pckeyboard) . Why is SSHing from a phone no fun? Honest question, what am I missing out on?

<comment><USER3> Hi! I'm the author of TapChat.

Scrolling and switching between windows is quite slow and unpleasant with Irssi+Screen+ConnectBot on a phone. TapChat has a native UI and is much more responsive regardless of your connection quality. It also sends push notifications to your phone when someone mentions or messages you.

<comment><USER6> There's an app called "Irssi ConnectBot" that adds support for scrolling and switching windows with touch gestures.

<comment><USER5> I actually linked to it but didn't write the full name, fixed.

</comment></comment></comment></comment><comment><USER7> I don't know about its Node.JS implementation, but I think TapChat works great as a lightweight client to IRCCloud[1] (which is kind of like a bouncer on its own and don't have much option to configure to begin with). It simply Just Works™.

Some customization and a little bit of visual improvement for message would be welcome, though. Especially colors, I understand they want to keep it monochrome-ish, but trying to find message burying with joins/leaves is not really fun since everything looked the same. I wish it has IRCCloud-like join/leave grouping.

[1]: <https://irccloud.com/>

</comment><comment><USER8> I would pay for this if I could use my own ZNC bouncer.

<comment><USER9> That was my immediate reaction, too. Though it sounds like the node.js server is doing more than your standard bouncer; ZNC support seems unlikely.

<comment><USER3> Hi, I'm the author of TapChat.

I recommend connecting the TapChat server to ZNC, this works quite well.

</comment></comment></comment><comment><USER10> Something I've wanted to build someday but never did is exactly this but for xmpp, etc. I'd love to have a central place with my chat logs, etc.

Someone go build it, please!

</comment><comment><USER11> I'm curious about why you need a specific bouncer for this. I can't see any doc about what it does that usual bouncers don't do (except for "[existing bouncers] have many limitations such as not being able to sync private conversations across all of your devices", which I don't get: the bip bouncer which I use syncs private conversations in a very reasonable way).

</comment><comment><USER12> I sent you an email and this is just me being impatient but.. unavailable in the android market for Chinese users?

<comment><USER3> Hey, I just replied to your email. Paid apps are not currently available in China, it seems. You should be able to purchase the app from the web through a VPN or proxy and have it pushed to your phone. [https://play.google.com/store/apps/details?id=com.tapchatapp...](https://play.google.com/store/apps/details?id=com.tapchatapp.android)

<comment><USER12> Ah I didn't realize! This would also explain a lot of other things. Thanks!

</comment></comment></comment><comment><USER13> Is this (irc bouncer) the sort of thing that should work with Jabber? Keep the parts interchangeable?

<comment><USER3> Hi, I'm the author of TapChat.

There are very few things about the protocol that are IRC-specific, so this could likely be added in the future. In the meantime, I've had success using Jabber in TapChat via Bitlbee.

</comment></comment><comment><USER14> I'm so glad there's finally a good option for Android users!</comment>


Twisted graphene has become the big thing in physics - <AUTHOR> https://www.quantamagazine.org/how-twisted-graphene-became-the-big-thing-in-physics-20190430/ <comment><USER2> Fairly shocking to me that Yuan Cao received literally a single glancing mention here, but he was clearly the one who actually made the pivotal discovery, and is the first author on the Nature paper ([https://www.nature.com/articles/nature26154](https://www.nature.com/articles/nature26154)), and was the one named to the Nature 10 in 2018 for his discovery.

Really mind boggling that this entire piece focuses all the attention on his supervisor and almost neglects to mention him at all.

<comment><USER3> Usually the grad student does most of the work, but the ideas and direction comes from the supervisor. It's normal that the supervisor funds, directs and communicates the work that's being done. More often than not, the supervisor has a better idea of the big picture and the implications of the work than the grad student, so it's natural that the supervisor talks to the press.

For example, I'm a grad student, in a department where my supervisor would talk to the press on work that I would have done.

<comment><USER4> In CS related fields, in particular ML and CV, this is absolutely not the usual situation except perhaps in the beginning of the PhD. Perhaps it's more common in fields where the research is done on top of a heavy investment in infrastructure/equipment that is lead by the professor, e.g. in physics and biology?

<comment><USER5> In my experience in biology new professors provide a lot of ideas, old professors just steal new ideas from their students and post docs.

</comment></comment></comment></comment><comment><USER6> >Even without superconductivity, ordinary computers and other electronics could get a huge boost in performance versus cost from twistronics, due to the fact that entire complex electronic circuits could in theory be built into a few sheets of pure carbon, without needing a dozen or more complexly etched layers of challenging materials common to today's chips.

</comment><comment> ezequiel-garzon Does anybody know if the environmental impact of graphene is supposed to be any better than that of plastic? Does it break down more easily as it is so thin? I'm worried we may outdo ourselves with the magic compound of the century...

<comment><USER7> Another major 'environmental' impact that may be very nefarious is the health effect of such nano-materials.

We don't want to re-create all the mess that we have today form asbestos -- which was also a wonder-material at the time.

<comment> village-idiot The problem with asbestos wasn't really the toxicity per se, it's that the companies using it hid the toxicity to avoid having to do all the expensive safety steps that would let them use asbestos without killing people. We can avoid this with carbon nanotubes and similar if we're honest about the risks and careful with how we handle them.

<comment><USER8> This will probably happen again given all the money that's on the line.

<comment> village-idiot The fact that we're talking about it here implies that we're in a better place than we were a century ago.

<comment><USER9> A century ago yes, fifty years ago I'm not so sure, thirty years ago almost certainly not.

</comment></comment></comment></comment></comment></comment><comment><USER10> Yes. There's not applicable commercially viable things based on graphene yet. But superconductivity will be a revolution in many ways and especially in computing.

<comment><USER11> Superconductivity would revolutionize transportation, low cost medical imaging with MRIs, and weapons. Lots of weapons.

<comment><USER12> You're forgetting the two most important; energy storage and transport.

<comment><USER13> Yeah, imagine if we could more or less losslessly transfer electricity over vast distances. Massive renewable energy farms could be built wherever there was sun/wind/rivers whether the energy consumers are close or not. Energy could be sent to pump water into reservoirs as huge centralized batteries. The problem with 'what happens when the sun isn't shining/the wind isn't blowing' could be sidestepped because it's always sunny/windy somewhere, so we just get the power from as far away as needed.

<comment><USER14> People seem to underestimate how efficient regular power lines are. The continent-spanning european power grid has a total transmission loss of about 6% using 19th century technology (transformers and copper wires). Modern high voltage DC lines can perform even better. The main limitation seems to be that people don't want to have power lines in their back yard. Not something that superconductors are going to sove.

<comment><USER15> Also the cost of a equivalent superconductor network would be an order of magnitude more expensive that what is essentially room temperature metal cables with very basic technology - transformers, insulation, and switchgear.

<comment><USER16> A superconducting power network could be built today - it would consist of a pair of ceramic superconductors suspended in a liquid helium pipe, wrapped with 3 feet of insulation.

Every few kilometers, one would need liquid helium pumping and chilling plants.

Total helium losses to leakage wouldn't be too big. Electricity transmission efficiency would be reduced by all the chilling gear running, but still better than regular conductors.

The only real barrier is cost. Not even the cost of the superconducting material. You can't hang a 6 feet diameter pipe on pylons across the nation - you're going to have to bury it, and that's going to get exxxxxpensive fast!

<comment><USER17> > The only real barrier is cost.

I feel like this could almost be a slogan for the human race at this point. Our grasp of science and engineering has reached a level where's there's very few things we might want to build where we couldn't conceivably do it. We could build the most outlandish megastructures, infrastructure and space bases if we really had to, but it all just costs too much.

<comment><USER16> "It's expensive and we couldn't find investors" really means "It's a lot of work, and nobody thinks it'll be worth it".

We might be able to anything, but the capitalist system stops us doing things that don't look profitable.

<comment><USER18> Profitability at time X is a pretty decent heuristic for whether something is worth doing at time X.

<comment><USER19> How do you know that? Unknown unknowns.

<comment><USER18> Unknown unknowns are more likely to cause problems and delay completion, not accelerate development.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER20> Holy guac, room temperature superconductivity seems almost science fiction-y but just imagine the disruption it would make. I would be particularly excited to experience how much electric motors and energy transfer/storage and conversion would improve.

<comment><USER14> Apparently they reached superconductivity at 3K. Hardly room temperature.

<comment><USER21> The thing is they can use it to understand superconductivity because there are vastly fewer variables involved. It could _lead_ to room-temperature superconductivity, assuming it even exists.

</comment></comment></comment><comment><USER22> Pardon my interruption but I searched for 'use' or 'usage' and came up empty. Anyone can tell a regular guy why it's a big deal and what are the applications? ta

<comment><USER23> Superconductors = flying cars. Finally they are working on something useful!

<comment><USER24> Better make watertight social control devices if you want to hand everyone alien nose hair trimmers that can level city's. Same for the flying cruise.. Cars.

Some exponential tech, always seems to be 30 years away from legacy humanity. Thank you moderators.

</comment></comment></comment><comment><USER25> > Pablo Jarillo-Herrero is channeling some of his copious energy into a > morning run, dodging startled pedestrians as he zips along, gradually > disappearing into the distance.

Can someone please write up TL;DR about the actual science without the details on what kind of coffee did the author sip while taking the interview?

<comment><USER26> When two sheets of graphene are stacked, and twisted with respect to one another, they form a metameterial, with properties partially dependent on the twist angle.

At a twist angle of 1.1 degrees, the energy required for an electron in one sheet to tunnel to the other sheet drops to zero.

The problem is that certain angles represent a lower-energy state than others, so twisting to a magic angle also requires overcoming some buckling and creasing in the individual sheets, that allow regions to locally align to a non-magic angle (like zero degrees). This confounds measurements of the properties of the metamaterial.

Certain angles have been shown to exhibit superconductivity. While less useful than previously discovered superconductors for the purpose of moving electrons, these are more useful for studying superconductivity itself, because the superconductor is 2.5d, composed of a single type of atom, each with identical bond configurations. A lot of the variables that appear in other superconductors drop out.

<comment><USER25> You're a much better popular science writer than the author of the original article. Thank you.

</comment></comment></comment><comment><USER27> No mention of ballistic conductivity in CNTs which is well known, this is obviously very different?

</comment><comment><USER28> Where'd all the intelligent comments go? Hackernews used to be a cut above when it came to an intelligent comments section. Where'd all those people go, is there a new place to hang out?

<comment><USER29> If you know th new place, you know the first rule of the new place...

A nice intro to superconductors [http://www.superconductors.org/uses.htm](http://www.superconductors.org/uses.htm)

the history of graphene, the "next best thing" since forever: [https://graphene-flagship.eu/material/Pages/The-history- of-g...](https://graphene-flagship.eu/material/Pages/The-history-of- graphene.aspx) (previous HN discussion - [https://news.ycombinator.com/item?id=8751946](https://news.ycombinator.com/item?id=8751946) )

</comment></comment><comment><USER30> Is this a bigger thing than borophene which was a big thing a few weeks ago?

<comment><USER31> I'm gonna say "no". This is only relevant in that it might lead to better understanding of superconductivity. When the models can predict this, they will have made progress.

</comment></comment><comment><USER32> So... I'm an idiot but I have a question: could this theoretically allow for a battery that never loses a charge and/or charges instantly?

FWIW— I literally know almost nothing about superconductors...

<comment><USER33> No, because that would violate the Law of Conservation of Energy, which according to our current understanding would imply that this form of "perpetual motion" is impossible as long as the system experiences some sort of load. [0]

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

<comment><USER32> I don't think I'm talking about perpetual motion at all...

When I say never loses a charge I don't mean it's limitless capacity. I mean it could be charged 1,000,000 times without any affect on the capacity of the system? Maybe a better way to say it, a battery that does not degrade with each use.

Superconductors allow for the perfect transfer of electrons without any loss? So like if I had a giant earth sized graphene wire superconductor for this example: could I have the energy travel around the ring indefinitely so long as it's closed?

<comment><USER33> Ok I see, by "not losing its charge" you meant not wearing down from repeated use. Technically speaking the charge would be the amount of electrical potential energy stored in the device.

This system is still subject to the laws of thermodynamics, however.

AFAIK _ideal_ superconductivity does not exist outside of theoretical physics, just as ideal platonic solids do not exist in the real world. Things get bumpy close up, and then they get fuzzy.

Even if you could maintain a "perfect loop" of electrons along a wire, perfectly insulated from outside forces including EMI and gravity, any observation of the system would still introduce entropy from the outside world and eventually degrade the system unless it is self-correcting.

An ambient self-correcting conductor would be a _massive_ breakthrough.

<comment><USER34> Charge is not amount of electric potential.

Charge is a property of matter which causes experiencing a force when placed in an electric field.

Strength of the electric field is electric potential.

And charges arrange in some form under this field which wouldn't be so in absense of this field and how tight is that form depends on the strength of electric field. And this can be used to perform some work but this is not storing charge as the total charge before arrangement is same as total charge after arrangement there is no new charge added. We are storing electric field here.

In all such storage devices, strength of the field goes down after sometimes.

No I don't know how it can help in case of batteries but assuming you use capacitor to store electric field the leakage can be decreased by using better insulation which in many cases is thicker and the capacitor is limited to some specific size, if you can decrease the surface area of the conductive plates, you are able to use thicker insulation which results in lower leakage so graphene can help here as it's just one atom thick.

<comment><USER33> > Charge is a property of matter which causes experiencing a force when placed > in an electric field.

From Wikipedia [0]:

"A battery's capacity is the amount of _electric charge_ it can deliver at the rated voltage."

Another way of saying this is that a battery can store potential electric charge which is _discharged_ from the battery during use. The maximum potential electric charge a battery can store is its capacity.

Similarly, a rock raised above your head is not "storing gravity", but it still contains gravitational potential energy.

When we talk about batteries however, we tend to colloquially refer to this electrical potential as "charge" due to the way words like "charger" and "discharge" have entered the vernacular. Phrases like, "How much charge does your phone have left?" has become increasingly common.

This is distinct from the definition of electric charge that you lifted from Wikipedia's page on "electrical charge". It's just the way language has evolved.

> And charges arrange in some form under this field which wouldn't be so in > absense of this field and how tight is that form depends on the strength of > electric field. And this can be used to perform some work but this is not > storing charge as the total charge before arrangement is same as total > charge after arrangement there is no new charge added.

We are not measuring the total charge. We are measuring the electrical potential across a circuit. The total "charge" remains the same, but the electrical potential decreases when the battery discharges.

[0] [https://en.wikipedia.org/wiki/Electric_battery#Capacity_and_...](https://en.wikipedia.org/wiki/Electric_battery#Capacity_and_discharge)

</comment></comment></comment></comment></comment></comment><comment><USER35> It is a really cool discovery, but it is still not room temperature superconductivity...

</comment><comment><USER36> It's great that now that regular graphene has become ubiquitous and has delivered on all of its promises to revolutionize tech we have something new to look forward to.

<comment><USER37> Is there a list of devices regular graphene has made possible?

<comment><USER38> I believe he is being sarcastic

<comment><USER39> Rats. I got excited for a second.

</comment></comment></comment></comment><comment><USER40> Its quite shocking to see that the hard bonded carbon sheets can also move in spite of their large forces of attraction betweeb them . Well its other effects would be overwhelming ..

</comment><comment><USER41> YAAWWWWN.

Graphene was going to transform everything. Years ago.

</comment><comment><USER42> Vittoria, a tire company have used Graphene tech of sorts in their bicycle tires: [https://www.vittoria.com/us/graphene- technology](https://www.vittoria.com/us/graphene-technology)</comment>


Ask HN: Need an engineering analogy for my book. - <AUTHOR> Hi everyone - I'm writing a book on B2B startups.  In it I describe the changing roles of leaders over time, from seed stage to IPO and beyond.  So, as an example, a sales leader goes from being Davy Crockett, out on his own in the wilderness, to Braveheart, leading a small band of guerrilla fighters, to Eisenhower, administering a complex machine.  I'd like to find a similarly relatable analogy for Engineering leaders.  I think it relates to what they build and how they build it, but I'm open to alternatives. <comment><USER2> Davy Crockett wasn't "alone in the wilderness"; he ultimately led militia and,eventually, regulars. A better example would be Dick Proenneke.

Lots of Engineering leaders started from the garage level, e.g. Gates, Jobs (or Woz), Hewlett and Packard, etc.</comment>


The Minnesota Goodbye - <AUTHOR> http://www.somerandomidiot.com/blog/2014/06/03/the-minnesota-goodbye/ <comment><USER2> For some additional context, the OP is working on fuzz-testing the network stack in Mirage (and she has a bunch of great posts up).

[http://openmirage.org/blog/welcome-to-our-summer- hackers](http://openmirage.org/blog/welcome-to-our-summer-hackers)

<comment><AUTHOR> Nice, will these be part of an automated test-suite? (to check that future versions of Mirage don't regress)

<comment><USER3> Definitely. Although instead of sending network packets to the fuzz tester, the idea is to apply a testing module to the network stack functor that introduces a deterministic random number generator. This makes it much easier to write assertions about how the state machine should behave within the stack, to catch bugs much more easily.

<comment><AUTHOR> I actually had in mind something else (code that just does TCP connections/HTTP requests and you run that against mirage / against a Linux stack and compare), but this sounds even better. Someone could still do that comparison (not on the TCP state though, just the reply) with the functor approach.</comment></comment></comment></comment>


Show HN: A Visual Intro to Algorithms (forked from Cormen's/KhanAcademy Course) - <AUTHOR> https://www.educative.io/collection/10370001/760001 <comment><USER2> I'm one of the co-founders of Educative (interactive courses for software developers).

We forked Cormen's and KhanAcademy course to add more interactivity, add challenges in multiple languages etc.

Here are more details. [https://www.educative.io/collection/page/10370001/760001/162...](https://www.educative.io/collection/page/10370001/760001/1620001)

Happy to answer any questions.

</comment><comment><USER3> Oh, wow. Pretty cool primer on algorithms</comment>


Belief that some fields require 'brilliance' may keep women out - <AUTHOR> http://www.sciencemag.org/news/2015/01/belief-some-fields-require-brilliance-may-keep-women-out <comment><AUTHOR> I'd rather seen this formulated as "Belief that some fields require brilliance may keep people out" as the article in one paragraph notes this also applies to Asian-Americans vs African-Americans, so it seems to be more a case of "groups of people are pushed out of fields where the bias is that they need to be brilliant to be there", but given HN frowns upon editorializing titles I left it as it was.</comment>


How to build aviation software and why I quit flying to build a startup - <AUTHOR> http://eduardo.intermeta.com.br/posts/2013/2/10/making-aviation-sofware

<comment><USER2> And remember that Fiji is an archipelago of more than 332 islands that spans the international date line [1] meaning any sightseeing flights have fair chance of wandering backwards and forwards from -179.9 to +179.9 Longitude repeatedly in the same hour or two.

Can your avionics GIS & time software handle this?

[1] [http://www.worldatlas.com/webimage/countrys/oceania/lgcolor/...](http://www.worldatlas.com/webimage/countrys/oceania/lgcolor/fjcolor.gif)

<comment><USER3> That's a pretty specific edge case -- if your intended market was private pilots, you could just put a giant "WON'T WORK IN FIJI" sticker on it.

<comment><USER2> And that's the kind of thinking that resulted in pretty much 100% of North American produced commercial mapping software just not working in the region of Fiji when it was mapped in 1997 [1].

Luckily some of us can write our own mapping and avionics software.

Are you comfortable with developing avionics software that just won't work in some parts of the world? That seems a little shortsighted and a little dangerous.

[1] <http://www.mrd.gov.fj/gfiji/products/air_detl.html>

<comment><USER3> I'd be fine with that if it meant that the avionics software was cheaper because it cost less to develop. Your average private pilot in North America is _never_ going to need their avionics to be able to deal with this, just like they don't need the GPS in their car to be able to deal with it either.

<comment><USER2> Don't be lazy, just consider the case of crossing a discontinuity and deal with it correctly, if you're on a roll developing it doesn't increase the cost and it offsets liability later.

The standards for avionics software are not geared towards average use in any case. They are geared towards worst case scenarios that have actually happened and could actually happen, even if the odds are low.

Are you honestly claiming that a popular bit of avionics kit will _never_ find it's way to the region of Fiji? Ever?

<comment><USER3> What about compass anomalies when flying around the poles? What about flying at extreme altitudes?

If we're talking about avionics for Boeing passenger jets, that's one thing -- but those aren't going to be the same avionics that go into a Cessna 172 or a glider. That's why differing standards exist.

And no, I'm not claiming that -- that's what the giant sticker is for. If you're concerned about that sort of thing, make your hardware open and people can put on whatever custom firmware they like.

<comment><USER2> When flying, navigating or surveying in polar regions it pays to have control (or an understanding) over the translation from raw sat packets to polar suitable coordinates, when flying at extreme altitudes it pays to have the same as numerous commercial GPS units have altitude and/or speed cutouts.

I'm certainly not talking avionics for commercial passenger craft, I'm talking about the avionics for routine global scientific measurements, geophysics, weather balloons, cheap drones, etc - all of these are application areas where roll your own avionics that aren't written by North American bound myopics are applicable.

</comment></comment></comment></comment></comment></comment></comment><comment><USER3> Some interesting info on developing software that's required to meet certifications to be safe for use in flight hardware.</comment>


X += x++ - <AUTHOR> http://blogs.msdn.com/lucabol/archive/2004/08/31/223580.aspx

<comment><USER2> This is essentially a small piece out of a much bigger pie, which is that if you program in languages that allow you to be 'clever' you should use a 'safe subset' of that language where behaviour is both unambiguous and the same across all platforms. This will save you a lot of headaches debugging a program that works fine on a different installation.

There are many other examples of this, for instance always use 'sizeof()' even if you know your storage allocation units, don't rely on the byte order of your words (endian-ness), stick to _one_ statement (explicit or implicit, the example line from the article has two statements).

What makes the example so tricky is that you have to know the innards of the compiler (or at least of the expression evaluator) to be able to correctly predict what that code will do.

Some people think there are bonus points to be had for such 'cleverness' because you only need one line where someone else needs two. There isn't and all it will give you (or, possibly your successor) is a bunch of extra gray hairs.

A similar case can be made for always using brackets, even when they're optional, not using assignments in condtionals and so on.

It's the kind of thing where a junior programmer will go 'oh, cool!', and a seasoned one will go 'oh oh'.

In the case of complicated expressions feel free to add some extra parentheses to make the order of evaluation implicit. They don't cost you anything and they'll allow someone else to read the expression from the inside to the outside instead of from the left to the right and then apply the order-of- evaluation rules.

If you come across:

         x = y + z*a + b*d^i++;

And you think it does the same as:

         x = y + (z*a) + (b*(d^i)) ;
         i++;

Then think again, it is equivalent to:

         x = (y + (z * a) + (b*d))^i);
         i++;

There is absolutely no penalty for writing it down explicitly.

Sure, some seasoned old hand is going to say, hey, don't you know the expression evaluation rules by heart ? But don't let that intimidate you, that's probably also the person that spends a lot of time in the debugger fixing their extreme cleverness.

The compiler will generate exactly the same code for either the first or the last example (but _not_ the second), there really is 0 penalty, use that.

<comment><USER3> The compilers might be more helpful, too, by displaying hints or even warnings when the clever code is used. This would not forbid it but would encourage for universally cleaner code.

<comment><USER2> Some compilers do that actually, and there are also code inspection tools that will give you warnings about such constructs.

</comment></comment></comment><comment><USER4> I don't know as much about C# as I do C or C++ but they both have the concept of sequence points in between which order of operations is undefined behavior. As such I find his specification of order of ops suspicious and makes a stronger argument for explicit statements. However the whole if you don't know what it does then you should be learning not dumbing down the rest of us should apply.</comment>


Apple CEO Tim Cook May Have Violated SEC Rules with Jim Cramer Email - <AUTHOR> http://www.marketwatch.com/story/apple-ceo-tim-cook-may-have-violated-sec-rules-with-jim-cramer-email-2015-08-24

<comment><USER2> Also: [http://www.zerohedge.com/news/2015-08-24/did-tim-cook- violat...](http://www.zerohedge.com/news/2015-08-24/did-tim-cook-violate- regulation-fair-disclosure-emailing-jim-cramer-save-aapl-stock-)

>> Then again, with AAPL leading the S&P rapidly into the green, we are confident this, too, will be promptly forgotten and swept under the carpet of "whatever it takes to keep the market green."

:-\

</comment><comment><USER3> This article is complete bullshit.

Cramer read the email on the air at 6AM, a half hour before the markets opened. Clearly Tim Cook intended that this information be widely disseminated and Cramer did exactly that. It's not like Cook was giving Cramer private information to allow Cramer to trade ahead of the public.

<comment><USER4> The host of a show that is about to reveal information that can be reasonably expected to coincide with an upturn in the stock, is most certainly in a privileged position. If he acted in it, Cramer would be under the lense too.</comment></comment>


Apache Foundation new website - <AUTHOR> http://www.apache.org

<comment><USER2> I love apache - but I have to say, that's a little on the ugly side : ) Not that it matters. Apache FTW!

<comment><AUTHOR> Exactly. Why ruin a perfectly good website?</comment></comment>


5.7 GHz on 28 Cores: Overclocking the Intel Xeon W-3175 - <AUTHOR> https://www.tomshardware.com/reviews/overclocking-intel-xeon-w-3175x,6097.html <comment><USER2> > _You start pulling the block off, and to your surprise, there is zero > resistance to your force but while you are shifting the block away you hear > an almost velcro-like ripping sound. That is the sound of 3647 pins shifting > around as the CPU is pulled off the socket while attached to your water > block by the thermal paste in a sort of robotic peanut butter and thermal > grease sandwich._

author gets a Michelin star for this recipe alone</comment>