Scientists Achieve Direct Counterfactual Quantum Communication - <AUTHOR> http://www.sciencealert.com/scientists-have-achieved-direct-counterfactual-quantum-communication-for-the-first-time <comment><USER2> Does it require entanglement? No.

> Direct counterfactual quantum communication on the other hands relies on > something other than quantum entanglement. Instead, it uses a phenomenon > called the quantum Zeno effect.

Does it violate the speed of light? No.

> It works based on the fact that, in the quantum world, all light particles > can be fully described by wave functions, rather than as particles. So by > embedding messages in light the researchers were able to transmit this > message without ever directly sending a particle.

Is this a sleight of hand? I don't know... ("New system of angular motion doesn't require radians! Uses 'degrees' instead.")

> ...all light particles can be fully described by wave functions, rather than > as particles...

</comment><comment><USER3> Wow, I remember reading a paper on this as a theory about 10 years ago in Scientific American. At the time I don't recall the paper actually having a way to do the experiment, it was in the category of 'look what the math says is possible'.

</comment><comment><USER4> from the abstract

> Intuition from our everyday lives gives rise to the belief that information > exchanged between remote parties is carried by physical particles. > Surprisingly, in a recent theoretical study .. quantum mechanics was found > to allow for communication, even without the actual transmission of physical > particles.

ok, does this also mean that communication is free from restraints that particles suffer.. as in would this allow faster than light communication?

<comment><USER5> The speed of light isn't a property inherent to physical particles. It is far more fundamental than that.

Check out the PBS Space Time channel. They have a number of excellent episodes on the speed of light, causality, etc...

<comment><USER4> yeah, i'm sorry i should have been more clear

what i am interested in is:

i understand that solely utilising quantum entanglement, a ftl phenomenon, one is unable to communicate classical information but does this method utilise the zeno effect to afford this communication by controlling when to cease and reinstate the systems evolution?

two parties with entangled particles within quantum systems agree on a baud rate and the transmitter alters the systems evolution until it takes on a desirable state then arrest the evolution until the next scheduled modulation, then evolve the state to the next desired expression, wait for the next modulation, and on and on

effectively the information transfer would adhere to causality, the observer would be subject to the baud rate, but the distance traveled between the parties could be greater than one that light could travel within that baud rate

<comment><USER6> Er. Quantum entanglement is not a faster than light phenomenon. Or, at least, describing it as such is rather pointless. It's no more 'faster than light' than 'realizing something about a faraway place' is.

<comment><USER7> Isn't collapse of the probability wave instantaneous across the arbitrary distance between entangled particles, from the frame of the measurement, in violation of relativity, and isn't that what Einstein disliked?

<comment><USER8> The wave function isn't really this thing that physically exists but is really a data structure which exists only in your head that captures the information you have about a quantum system. So yeah collapse is instantaneous, but that's just because you can update something in your head instantly because you learned something about something that happened far away.

<comment><USER7> I don't know that that's true. I'm by no means, even remotely, an expert. But it sounds like you've got a "hidden variables" take on it; that you're suggesting the probability wave is our statistical prediction of a systems state limited by our ignorance, which is what Einstein believed, and has been since contradicted by physical experiment showing violation of Bell's inequality? Am I mistaken? Feel free to correct me.

<comment><USER8> Ah that's not what I'm saying but it's subtle. Access to hidden variables, if they existed, would allow you to predict a measurement outcome. I'm not saying that. I'm saying the wave function is a tool that allows you to write down all the correlations. In other words, the wave function is a tool that allows you to reproduce all the probability distributions

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER9> They still transmitted light, they just called it a wave instead of a particle.

Am I missing something?

<comment><USER10> Yes, you're missing whatever's hidden behind the journal paywall.

It's been _way_ to long since my one quantum physics class, but looking at the pretty pictures I _think_ they got their photon to interfere destructively with itself over the entire length of the transmission channel between a pair of beam splitters.

Which I don't think is possible with ordinary waves (say in water), which I suppose is probably what the big deal is.

<comment><USER11> If you go Full Copenhagen and start thinking about QM as a calculus of probability densities in physical systems it begins to make a lot more sense than trying to think about it as an impossibly weird version of Newtonian mechanics for waves+particles+wtf.

It means you can stop playing "Where's the photon?" and accept that these experiments are doing spatially distributed probabilistic computing.

In this view there is no photon - there's only a map of possible photon-like event positions distributed in spacetime, and one or more end-points tuned to pick up photon-like events by sampling the map at specific spacetime locations.

The weird part is the way that interactions between the map distributions and the end-points are completely unintuitive, and you can do neat tricks like constraining probabilities by repeatedly connecting to an end-point, and creating dead areas where the probability of an event is zero but which don't "block" events around them.

That just emphasises that the Newtonian-ish view is the wrong model. The right view is still TBD, but it seems to be some kind of holistic summary view that somehow - no one can even begin to guess how - creates a map by integrating over all possible interactions.

This is not what we're used to, but discovering that reality doesn't do what we expect is the point of science, so that's not a bad thing.

<comment><USER12> Please stop waving your hands. I prefer the deBroglie-Bohm interpretation where you have both a particle and a wave. Changing the shape of the wave by changing site B setup changes where the particle ends up, even if the particle does not leave site A. (However, for this experiment to work, there should be a chance for the particle to travel from A to B, otherwise the pilot wave won't travel either)

</comment></comment></comment></comment><comment><USER13> Abstract for paywalled PNAS paper:

[http://www.pnas.org/content/114/19/4920.abstract](http://www.pnas.org/content/114/19/4920.abstract)

The image transmitted was a monochrome bitmap graphic of a Chinese knot:

[https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Ei...](https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Eight_chinese_knots.jpg/1200px- Eight_chinese_knots.jpg)

...no resolution noted in the abstract, but probably small and pixelated, since it was serialized as photomultiplier clicks.

</comment><comment><USER14> If you want to read the paper, type in your address bar sci-hub.cc and a slash, and then paste the DOI after the slash.

</comment><comment><USER15> We are receiving a wireless telegraph! It is from Marconi. He wants us to get off his lawn.

<comment><USER16> We detached this comment from [https://news.ycombinator.com/item?id=14346911](https://news.ycombinator.com/item?id=14346911) and marked it off-topic.

</comment></comment><comment><USER17> Title: Scientists Achieve Direct Counterfactual Quantum Communication For The First Time.

Article: "The results will now need to be verified by external researchers to make sure what the researchers saw was a true example of counterfactual quantum communication."

Okay then

<comment><USER18> This is usual. I don't know why they explained it here. [1]

This result was published in a peer review journal. It means that two or three experts read the article and found no evident flaw and think that it has enough details to make the experiment in another laboratory [2]. They didn't go to the laboratory and unbolted every piece to double check the setup, or make a copy in their own laboratory to check the experiment. So until two or three more laboratories try this and a few variations, this is still doubtful, but there is a good chance that this is true.

[2] Usually the papers don't have enough information. You have to guess and email the authors and cross your fingers to reproduce the result.

[1] My guess is that they explained this because the result is very unintuitive.

<comment><USER19> As you sort of imply in your second footnote, "has enough details to make the experiment in another laboratory" often _isn't_ a requirement to pass peer review, sadly.

<comment> semi-extrinsic It's frequently a loose requirement; trouble is to know how much information is necessary to replicate, you typically have to do the actual replication (and iterate with authors over details). Not to mention that journals tend to dislike overly long papers.</comment></comment></comment></comment>


Show HN: I wrote a book on Python regular expressions - <AUTHOR> My book titled "Python re(gex)?" is free to download through this weekend [1][2]
The book covers both 're' and 'regex' modules, has plenty of examples and chapters also have cheatsheets and exercises.
Code snippets, exercises, sample chapters, etc are available on GitHub repo [3]
I used pandoc+xelatex [4] to generate the pdf.
[1] https://gumroad.com/l/py_regex
[2] https://leanpub.com/py_regex
[3] https://github.com/learnbyexample/py_regular_expressions
[4] https://learnbyexample.github.io/tutorial/ebook-generation/customizing-pandoc/ <comment><USER2> You might like:

[https://github.com/mtrencseni/rxe](https://github.com/mtrencseni/rxe)

So you can write:

      username = rxe.one_or_more(rxe.set([rxe.alphanumeric(), '.', '%', '+', '-']))
      domain = rxe.one_or_more(rxe.set([rxe.alphanumeric(), '.', '-']))
      tld = rxe.at_least_at_most(2, 6, rxe.set([rxe.range('a', 'z'), rxe.range('A', 'Z')]))
      email = (rxe
        .exactly(username)
        .literal('@')
        .exactly(domain)
        .literal('.')
        .exactly(tld)
      )

<comment><USER3> This seems cool, but I think that's mostly because the regex you think of as a point of comparison is something like

        r'^[\w.%+-]+@[\w.-]+\.[a-zA-Z]{2,6}$'

which does look awful. But there's no reason you can't do

        username = r'[\w.%+-]+'
        domain = r'[\w.-]+'
        tld = r'[a-zA-Z]{2,6}'
        email = username + r'@' + domain + r'\.' + tld

which is arguably easier to read than the rxe version for someone familiar with regex.

<comment><USER4> wow I didn't know you could concatenate regexes, thanks

<comment><USER5> Why not? They're just strings until they're compiled. "Code is data"

<comment><USER4> Well I suppose the r in front of them in python made them look just enough "not a normal string" for me to forget how the + operator might act.

My day-to-day experience is in nodejs, where adding one regex object to another coerces them to normal strings first

[edit: hey neat, the hackernews form strips emoji from comments, I wonder if that's just ranges of unicode or if there's some crazy regex going on :D]

<comment><USER6> In Javascript you just need to wrap in `new RegExp(r1 + r2 + r3)`.

</comment></comment></comment></comment></comment></comment><comment><USER7> I personally learned RegEx with PowerShell for a work initiative that required heavy usage of it. Most of the documentation regarding RegEx was pretty language agnostic, so it's interesting when I run across guides that are specific to a particular language.

Is there anything about Regular Expressions in Python that creates a unique need for it's own domain specific guide?

<comment><USER8> None that I know of. My thought process has always been that regex was language agnostic. I think Perl has its own version that is widely used. But other than that, I do not know.

<comment><USER9> > My thought process has always been that regex was language agnostic.

+1

I was surprised to find that regex in python was not much different from the language I use ruby. Would anyone with sufficient knowledge care to eli15 why this is and how it is implemented ?

<comment><USER10> Ruby's regex engine is Onigmo which is very similar to Perl 5.10. Perl was one of Ruby's main influences, along with Smalltalk and Lisp, whereas Python's BDFL was never a fan of Perl. However, Perl's implementation of regular expressions (PCRE) has been widely adopted hence the similarity you refer to. If you compare with Javascript and PHP you'll find they're all similar.

</comment></comment></comment></comment><comment><USER11> Thanks for sharing! I only skimmed it but I liked how you include usage of the external regex module, which I hadn't realized allowed for the use of variable-length look-behinds.

<comment><USER12> The engine has support but the language doesn't expose it?

<comment><USER11> I don't think I understand your question (nor am I an expert on Python regex!)...but just to be clear, Python's regular expression standard library is named `re`. But there is an external lib – ostensibly a drop-in replacement – that goes by the name of `regex`. It is the `regex` library that supports variable lookbehind, _not_ Python's standard library `re`

[https://pypi.org/project/regex/](https://pypi.org/project/regex/)

</comment></comment></comment><comment><USER13> This is super helpful! I've always felt Python regex was one of the more complicated parts of the language.

</comment><comment><USER14> Congrats on writing and publishing this book!

</comment><comment><USER15> Thank you very much! This is really helpful.

</comment><comment><USER16> This is a great resource. Thank you for taking the time to write this and making it available to us!

</comment><comment><USER17> There two kinds of text search/parse problems:

\- The really easy ones. A simple string search/split will do and a regex would be overkill. \- The really hard ones. You'll need to fully parse this and using a regex will result in fragile/hard to understand code.

Please don't use regexes in production software. Learn how to write simple parsing code.

<comment><USER18> Can you elaborate a bit on this please? I'd be interested in resources on writing better parsers!

Quickly looking at the python standard lib (urlparse, shlex, etc) and Python packages (NLTK Treebank tokenizer), a lot of packages related to slicing, dicing and parsing strings use a mashup of regex and rule based code.

<comment><USER19> No experience with them in python, but look also for PEG grammars. They are significantly simpler than the traditional tower of lexer + ambiguous limited lookahead grammar.

Plus the memoized Packrat algorithm allows throwing in functions with custom conditions. (Somewhat like parser combinators, they also support custom logic.)</comment></comment></comment>


Apple says Pokémon Go is the most downloaded app in its first week ever - <AUTHOR> https://techcrunch.com/2016/07/22/apple-says-pokemon-go-is-the-most-downloaded-app-in-its-first-week-ever/ <comment><USER2> Shows you just how much pent up demand there was for Nintendo to release games on mobile.

Getting a huge first week download count is a lot easier when you have literally decades of brand recognition. Being a free download certainly didn't hurt either.

It remains to be seen what the customer retention numbers look like. I saw some absolutely insane projections earlier this week about how Apple and Nintendo were going to make billions off of Pokemon Go. I don't see how they're going to sustain the current game as it gets fairly grindy and there isn't much to do once you've caught them all. Maybe some compelling new features will be added to keep players from getting bored? Direct peer to peer battles and possibly trading for example.

<comment><USER3> > Shows you just how much pent up demand there was for Nintendo to release > games on mobile.

Does it? My impression is that there's a lot more people playing Pokemon Go than there are Pokemon fans. The IP no doubt helped, but I don't think that you can just release any Nintendo IP on mobile and instantly have the massive virality success of Pokemon Go. There's something more to it than that.

<comment><USER4> Yea, count me as one. I have literally never played any Pokemon game before, and half-caught maybe one episode of some TV show featuring some comical evil cat villain thing.

But, I'm catching pokemon on my walk to/from work (makes it less boring, and doesn't make it take any longer). My wife is now dragging me to the park every other day to run around in circles catching pokemon.

I'd be interested to see some survey results on what percentage of people playing this are actually pokemon fans.

<comment><USER5> 1\. We know pokemon is a powerful phenomenon people get hooked onto. 2\. You were previously not a fan of that phenomenon. 3\. You now started liking that phenomenon. 4\. The survey would show how many people started playing because they were hooked onto the phenomenon already.

</comment></comment></comment></comment><comment><USER6> When someone told me that Pokemon Go was exploding, I looked into it, and got really excited about its concept. People getting outside, interacting though a long-loved game, using real landmarks to denote checkpoints, playing a localized "king of the hill" type minigame. The architecture behind it and it really feels like it's using bleeding edge VR push us into a more social and fun world.

That said, I also feel like it's equally the biggest missed opportunity to date. Usually, I just see players walking, heads down, not talking. It was downright eerie when I was downtown one Tuesday night at midnight, and it was dead quiet despite ~60 Pokemon players meandering about. They should have introduced PvP earlier (hopefully it's around the corner!), and better yet, make it so you get more exp for battling people you haven't battled before. Spur people into social interaction!

<comment><USER7> You know that one mobile "space pilot" game? The one where everyone's phone displays different elements of a fictional spacecraft, with buttons labeled "Power Overdrive" and knobs and levers to pull with crazy names? And players get instructions they need to shout to other players, like "Whoever has the Neutrino Ray, set it to 4!"

Basically, the game forces one big fun social interaction by requiring players to exchange information to stay alive.

How could this work with Pokemon Go? I don't know. Currently the only social exchanges are "There's a Blastoise over here!" (which is pretty darn cool). But maybe more could be done. Some type of puzzle where one person in an area is designated the "Puzzle leader," and gets to rely information to other people...

<comment><USER8> Ooo! You're talking about Spaceteam I presume?

[https://play.google.com/store/apps/details?id=com.sleepingbe...](https://play.google.com/store/apps/details?id=com.sleepingbeastgames.spaceteam&hl=en)

[https://itunes.apple.com/us/app/spaceteam/id570510529?mt=8](https://itunes.apple.com/us/app/spaceteam/id570510529?mt=8)

</comment></comment></comment><comment><USER9> I'm confused by the title. Is PoGo the first app to reach x downloads in the first week of release, or is it the most downloaded app of all time, just one week after release? Slow internet won't let me view the article.

<comment><USER10> "While the game was only available in a few countries at the time, the app has attracted more downloads in the App Store during its first week than any other app in App Store history."

<comment><USER11> That probably mean that hey had more downloads then any other app's first week but it could also mean more downloads then any other app since their initial release?

</comment></comment></comment><comment><USER12> This game has become a victim of its own success. Niantic has be strangely silent about bugs and server outages. I foresee a massive drop in interest soon.

<comment><USER13> I keep seeing these comments foretelling the "inevitable" doomsday from the development community. This is a surprising sentiment. What Pokemon Go has shown, regardless of its future success, is a new ceiling for mobile app virality.

Also notable is that people always cite the issues as the reason for failure. But these issues have affected the app since day 0. Pokemon Go is having this success _despite_ its technical flaws. Further evidence that building the right product trumps building a flawless product.

I say flip the narrative. What Pokemon Go has shown is that a product that fills a burning desire can achieve what seems like unprecedented success levels, quickly. The app doesn't need to be perfect. It needs to be something people want.

<comment><USER14> I've been playing since day one and I've already lost interest. Most everyone I've spoken to is of the same thinking. It was fun at the beginning but there is simply not enough substance in the game to keep anyone interested for more than 2-3 weeks. There are only so many Doduos and Pidgeys you can catch before you are bored out of your mind.

<comment><USER15> I'm actually at level 23, and I'm trying to "catch them all" \- or at least, all that are in my country. Once I do that, I'll probably just wait for more content. That way I'll be well positioned if new content comes out.

The game hasn't even been released in every country, and to be honest I don't think it should have been released at all (at least until the combat system was decent). However, they clearly have an extremely popular game. Even if 99% drop off, and only 50% return they will still be raking in the dough.

<comment><USER12> Just out of curiosity, how long did it take you to get to that level? I am still rocking a level 12.

<comment><USER15> Well, I leave the game open at work and just spin the stops near me (there are three). Ive also walk an average of 20k steps per day since Pokemon Go came out.

I usually walk 15k steps, so it was a 30% increase.

</comment></comment></comment></comment></comment></comment><comment><USER16> 75% of the time I launch the game, I'm confronted with an error that I couldn't be logged in.

Maybe the game is so popular because it feels like a rare resource. It's so hard to get into the game that when you do you have to play it as long as possible until the servers go down again.

</comment><comment><USER17> Funny retrospective on the last 25 years of AR:

[http://unanimous.ai/augmented-reality-then-and- now/](http://unanimous.ai/augmented-reality-then-and-now/)

</comment><comment><USER18> The numbers will absolutely drop. I mean, there's definitely a ton of content that can be added like earning gym badges, Gen 2-6 Pokemon (which people don't really care about), trading, PvP, etc. But, at the end of the day I doubt Niantic has the time/resources for that. The execution has been rather poor.

Still though there's a demand for Nintendo software on mobile. They just need to really to execute. They're really lucky we're tolerating these huge bugs (nearby Pokemon and frozen Pokeball after catch still outstanding).

<comment><USER19> Got to love Hacker News! Fastest downloading app of all time, global phenomenon, absolute zeitgeist..."The execution has been rather poor."

<comment><USER20> > Fastest downloading app of all time, global phenomenon, absolute zeitgeist

All three of which can be attributed in large part to the Pokemon IP, rather than any other characteristic of the game.

<comment><USER21> You're saying that like Nintendo had nothing to do with making that IP what it is in the first place.

<comment><USER22> Nintendo did. Not Niantec

</comment></comment></comment></comment></comment><comment><USER23> I think that the biggest feature that Pokemon Go will add, that will hopefully come soon, is the ability to broadcast your position.

This is something that I wish ingress had done. The game is a multiplayer game, there is no doubt about that. I'd love to be able to open map map, see that some of my friends are over playing at $foo location, and then go meet them there.

<comment><USER24> Ingress had at least a proxy for that - an in-game chat with distance- filtering, i.e. you could limit messages you see to sources closer than X kilometers. As for third-party tools, someone somehow made a player tracker once; I think it used changes in portal owners to narrow down your location.

<comment><USER23> I think that the player tracker could get you banned from the game, though. It technically violates the ToS.

</comment></comment></comment><comment><USER25> Would love to know the app who previously held the record.

<comment><USER26> Clash Royale would be my guess. Recent release, IP carries over from a very popular existing game, but it's not just a sequel. Also had great word of mouth from the geobeta.

<comment><USER27> I have to speculate that Minecraft and Angry Birds have both individually had more downloads than Clash Royale.

<comment><USER28> Not the first Angry Birds, that was a snowball hit not a first week blowout.

Minecraft is paid.

I would guess FB Messenger or maybe Google Maps. Or something from China, seems like when QQ releases a core app there's millions who just go and download it.

<comment><USER29> Maybe Instagram? It was a Day 1 hit..

</comment></comment></comment></comment></comment><comment><USER30> A game can't have everything the first day of launch. They released this to test it against the market. Now that it is a success, changes will come to increase retention and purchases. Now the next biggest events will be promoted also with Pokemon things to do in the place, like "get this rare pokemon on the Vegas Electronic Event. The game is a real success and the mechanics described by Richard Bartle proved that people loves to collect, it is the Diogenes syndrome but in mobile version.

</comment><comment><USER31> The dropoff in interest has already started. I pretty much stopped playing last week. I got to level 14 and the amount of grinding required was just ridiculous (the amount of XP you earn per action does not increase as you level up meanwhile the XP required to level up goes up exponentially). The bugginess of the game really did not help.

The dropoff in interest has already, objectively speaking, started[0]. It's currently (as of July 22) 66% of its peak (per Google Trends). In my personal experience, interest on my college campus has already subsided. It's not completely dead, mind you, but the hype is over.

[0]: [https://www.google.com/trends/explore#q=pokemon%20go&date=to...](https://www.google.com/trends/explore#q=pokemon%20go&date=today%201-m&cmpt=q&tz=Etc%2FGMT%2B4)

</comment><comment><USER32> Have I missed something, or is this game just about walking around collecting pokemons with eggs? Is there anything else to it that I missed? The interface isn't illuminating.

<comment><USER33> > is this game just about walking around collecting pokemons with eggs?

Pretty much.

You can also battle to control gyms, but the rewards are pitiful and the combat system / pokemon types are so poorly implemented that it's basically a waste of time. Where I live, all the gyms change teams every minute or so.

So you collect pokemon, level up, and pray that Niantic will add some better features soon (trading, PvP, ladder system, more rewards for gyms, etc.). But there's no indication that they'll do so...

<comment><USER34> There are actually some indications of enhancements and new features, trading being one that is confirmed: [http://www.polygon.com/2016/7/12/12158480/pokemon-go- trading...](http://www.polygon.com/2016/7/12/12158480/pokemon-go-trading- update)

</comment></comment></comment><comment><USER35> These numbers are probably the reason why niantic was totally caught by surprise and have these massive server issues. I really don't like to see the app offline every time I have to go for a longer walk, but hey, I take it easy and wait for either niantiv upgrading their ressources or the userbase to shrink, which shouldn't take too long imo.

</comment><comment><USER36> So, do we have an entirely new class of games/apps that are about to appear? Like Pokémon go but for ...

<comment><USER37> Yes. I bet you plenty of companies are already on it as we speak.

</comment></comment><comment><USER38> How does the numbers stack up between the downloads on Google play vs Apple?

</comment><comment><USER39> As time pass there are more iDevices.... so the number can be irrelevant. So maybe a percentage as download/devices?</comment>


New research about sexual predators, and why police fail to catch them - <AUTHOR> https://www.theatlantic.com/magazine/archive/2019/08/an-epidemic-of-disbelief/592807/ <comment><USER2> regardless of how you view the criminal justice system, the nationwide backlog of rape kits feels unconscionable. These are not quality of life or minor drug offences, so I'm surprised there isn't more public outrage.</comment>


What it's like to go into lockdown for the second time - <AUTHOR> https://elemental.medium.com/what-its-like-to-go-into-lockdown-for-the-second-time-97f4d3bcdb5b <comment><USER2> I've not really come out of lockdown since late February.

Once there was any community transmission on the continent i knew the jig was up, so we were pretty cloistered off about two weeks early.

State numbers look good but I've yet to substantially change my behavior since I started working from home. Big restocking food trips several weeks apart, no-contact outside activities only, etc.

We've only started doing any kind of outside-only-masks-except-when-eating limited contact with family in the last 3 weeks or so, and even that is fragile feeling.

<comment><USER3> Alternate explanation: you work from home (thus aren't forced out of the house) and you are entertained enough by HN and Reddit and Netflix and whatever you do to have no real desire to leave, and since you have _any_ concern about the virus, you confuse your indoor shut-in lifestyle (which most of us have) as some positive premeditated rational character trait that everyone else lacks.

I'd wager that explains almost all of the self-congratulating I see online.

<comment><USER4> Or I'd really like to leave the house, go to concerts again, go to restaurants, work at my desk at the office where I can better keep life and work separate and have a great view of the mountains.

But I also know several fairly young people that have died with no comorbidities (as young as 38), and several others that have survived but are in a mental fog months later, and know the importance of staying in.

<comment><USER5> You can't even go outside?

<comment><USER6> I'm not the person to whom you replied but my answer is: Sure, and I do, quite a lot, but it's not the same. I've deleted 12 different things from my calendar that my family was going to do between early March and now. A trip to see friends in another country, three baseball games (just the ones we'd bought in advance), two different conventions, and more.

All ruined because of this stupid virus.

None are replaced by a brisk walk outdoors.

</comment></comment></comment></comment></comment><comment><USER7> I'm an American living in Melbourne right now (and, I guess, for the foreseeable future) and I've been very impressed with the way the government here has been handling restrictions. They're really doing everything they can to impress the seriousness of this on the population, and of the paramount importance of saving lives.

When I chat with my friends and family in the US, I find myself quietly surprised when they mention things like travel or hanging out with friends. "Oh right, not everyone is locked down like we are." It's tough in some ways - my partner and I really miss hiking - but we're more than willing to keep this up until it's clear that we've contained the spread.

<comment><USER8> Out of curiosity, why can't you go hiking? That seems like one of the few activities where you can just about guarantee social distancing by going to more remote areas. Is it explicitly prohibited? If so, I have to question the logic behind that.

<comment><USER9> You can only exercise for 1 hour a day, and you must wear a mask everywhere outside and they have the police out in popular rural areas enforcing this.

I'm not sure if its allowed to drive 2 hours to walk for 1 hour or not. I doubt it.

<comment><USER10> Sounds like a dystopian police state

<comment><USER11> A strict, short lockdown is far preferable to the five months so far of half assed containment that has failed to even reduce cases relative to the beginning of lockdown.

To make this work, there must be enforcement. From my observations, most spread is coming from people not following guidelines.

</comment></comment></comment></comment></comment><comment><USER12> I once thought coronavirus is far away even with the level of mandatory lockdown we've endured, none of my family member were affected. Until a few days ago, a remote cousin of mine who was studying in NY died because of it, and it felt real. I'd be so willingly under lockdown for so many more days if that will bring her back. Even if we hardly met, it felt real, and so close.

</comment><comment><USER13> This was written a day ago and it's annoying to see the author state "cases are only going up" when it has been widely reported that the number of cases in Victoria peaked around a week ago - thanks to the strict lockdown.

Victoria is also unique in that it is the only state in Australia with a large outbreak. The government has huge economic and social incentives to contain it.

Victoria charts: [https://www.theage.com.au/national/victoria/ten-graphs- that-...](https://www.theage.com.au/national/victoria/ten-graphs-that-show- victoria-s-coronavirus-trends-20200709-p55ajk.html)

I'm sorry that the writer is suffering, but as an Australian living in the US id prefer to undergo several weeks of draconian lockdown enforced by the police that could practically eliminate coroanavirus rather than what is probably going to be at least 12 months of restrictions in the US, and hundreds of thousands of deaths.

<comment><USER14> There's no evidence that a strict lockdown for several weeks can practically eliminate coronavirus indefinitely without perfect control over a non- permiable border.

As soon as people (or even goods) can move freely across the border of your strictly locked down area you're back to positive cases spreading through a susceptible population.

<comment><USER15> The three essentials: strong borders, lots of testing & tracing, and social distancing (including masks).

I've read epidemiologists saying that there's kinda a CAP theorem for epidemiology. Namely, you can trade off one if you're strong on the others: if you're going to have a greater risk of letting it in from weak border controls, then you have to make it hard to catch (distancing) and detect & eliminate it fast when it shows up (testing & tracing). Similarly, if you don't want distance then you've got to be very strong keeping it out and finding it if it shows up. And if you're slack on testing & tracing, then be extremely vigilant on not getting it in the first place.

</comment></comment></comment><comment><USER16> We gave up on lockdown here. Almost 70k cases daily making up a significant chunk of the _total tested people_.

Specifically, where I live (India, some small part) - most have forgotten about hand sanitizer or face masks.

I don't think a lockdown would be a good option for us but people can at least maintain caution for themselves and others which they aren't.

</comment><comment><USER17> We are pretty close to a second lockdown in France too, but I think this time might be different: more local instead of whole country (by city/region?), more tests, available masks and gel, better knowledge of the things to do, remote work already well in place, ... It might end up being smoother.

<comment><USER18> Melbourne tried that but it didn't work :(

We had people leaving suburbs that had outbreaks, and when the army door knocked positive cases, a large percentage weren't home :angry:

People are selfish and will not self-isolate via the honour system. Melbourne only saw cases drop after the threat of fines for leaving home happened. Incentives matter.

</comment></comment><comment><USER19> Here in the UK the cases are going back up again. We're currently lower than France, Spain (which seems to be really taking off), Belgium, Luxembourg and Sweden, but have higher rates than Germany and the other Nordic countries. We've had local lockdowns, but we'll have to see if that works. It's the holiday month, and seaside towns are fully booked with tourists. People were desperate for a holiday, my family included, but it seems premature, and these busy seaside places are not suited to social distancing. Hospitals are trying to get the elective work going again, but everyone's keeping an eye on the numbers, which threaten to choke elective pathways. Generally, everyone seems to be struggling a bit psychologically. People are slightly grumpier, slightly more aggressive. Petty crime seems to be going up. My shoe trees were stolen at work. Why? My wife has had to park her usual intellectuality stimulating work and homeschool our children for several months now. She's done with that. I totally empathize with the writer. This has become a war of attrition.

<comment><USER20> Are you talking about the number of identified cases per 1 million or the number of deaths per 1 million? Looking at the death tolls, you are only lower than San Marino, Belgium, Peru, Andorra and Spain.

<comment><USER19> Cases. Yes, deaths still seem high. I find that a little strange, as it doesn't fit the rate at all. It might be that the incidence has only just dropped after a delay compared to the continent. Or maybe that these are assummed COVID-19 cases that haven't been tested. But I also notice on the latest data a -78.9 deaths/million two days ago. Not sure if that is a mistake or a correction.

</comment></comment></comment><comment><USER21> At least they can go out for an hour of exercise. In Spain during the lockdown only a single person could go to the store a day. There won't be another mass lockdown people won't accept it and cases are climbing again. However the good news is that there does not seem to be equal explosion in hospitalisations or death.

</comment><comment><USER22> As a resident of New York City I absolutely cannot fathom another lock-down, and unfortunately I don't think a vast majority of residents my age would take it "seriously".

A big reason the lock-down ever worked was the sheer exodus of people from Manhattan. Brooklyn and outer boroughs never really had full-quarantine. People hate to admit it, but my friends who live in neighborhoods with high minority populations complained of constant block parties and drinking in the streets - largely pointing to why queens and Williamsburg were hit hard.

I lived a mere three blocks from one of the hospitals that was overrun with patients and for months had multiple chilled semi-trailers filled with dead bodies.

New York has been absolutely decimated, I honestly don't see small business and restaurants coming back in even two years, even if a vaccine is found. I'm starting to shift to the side of finding a compromise to help working class people get back on their feet. Government hand-outs will NOT fix this.

I whole-heartedly supported the first lock-down, but I no longer believe a second lock-down would really help anyone. Obviously, masks should become a social norm but I believe once daily testing before entering certain businesses or buildings will become commonplace. It's already common practice at hospitals and certain federal buildings.

<comment><USER14> If they aren't willing to lockdown protests then I can't quite see the point of locking down otherwise.

NYC is my canary in the coal mine. As long as NYC does not see a resurgence I will believe that the level of herd immunity in NYC is enough, combined with common sense hygiene practices, to keep Rt below 1.

<comment><USER22> Winter will be interesting both in terms of the NYC economy and covid. Once it's too cold for outdoor dining more businesses will likely close (there's just no way to avoid this, as someone with family in the restaurant industry I find it dumb that more people don't acknowledge how slim the margins of most restaurants are).

It'll be interesting to see how the remaining population in the city fares. If I wasn't waiting to see if I had an office in March or had a lease that I couldn't break there's no way I'd be staying here.

</comment></comment></comment><comment><USER23> Life's back to normal here in Berlin. Won't be for long - they're already making noises about rising case numbers and a second lockdown.

Second one will be harder, I think.

<comment><USER24> What things are not open or restricted for lockdowns in your area?

<comment><USER23> large gatherings of people (concerts, theatre, cinema) are still banned.

Most people don't go into restaurants and only eat at the outside tables, but that's voluntary.

Shops need masks and some attempt at social distancing, but the spatis (kind like corner shops but mostly selling cheap beer, very popular here) don't care about masks.

</comment></comment></comment><comment><USER25> Just a heads up that the sex scandal mentioned was a completely unsubstantiated rumour spread by Australia's Murdoch press, whose agenda is to politicise this outbreak.

<comment><USER26> I would confidently label myself a "Murdoch disliker", but I don't think "media conglomerate pushes news stories that generate the most anger/fear/hatred/etc (a.k.a. dollars)" is a partisan take in any way.

</comment></comment><comment><USER27> During WW1 and WW2 people went off to war to die or at best come back scarred from the experience, or people sent loved ones off to war. They grew victory gardens. They lived with shortages.

They survived. For years. A few months of lockdown/masks/distancing and we're crying like babies.

Come on. Life's tough. Wear a helmet (or in this case, a mask).

<comment><USER28> Using the language of war has been a common theme during the pandemic as a way to justify draconian measures. This isn't a war, nurses are not like soldiers. Lockdown is great if you work from home and can sip wine in the garden. Not so attractive for small businesses owners watching their livelihoods go down the drain or if you are stuck in a tiny high rise flat with 3 kids.

</comment></comment><comment><USER10> Total lockdown is overkill. Masks + social distancing are more than enough to keep cases in my area below ICU capacity.

In places where people refuse to wear masks and social distance... Let them die at slightly elevated rates, it's clearly what they want. I'm tired of the government trying to save lives at any cost against people's will.

<comment><USER29> The problem is that when people refuse to wear masks, it's often other people who end up dying because of it, even when the other people took more care.

The reason, of course, is that masks are only partial protection for the people wearing them.

<comment><USER10> > The problem is that when people refuse to wear masks, it's often other > people who end up dying because of it, even when the other people took more > care.

Yep, just like lots of other things. 41,000 people die of second hand smoke per year because of the actions of others around them. Yet we do not take drastic measures to prevent these deaths. Having freedom means the people might abuse it to harm others, even by inaction. Novel viruses like covid come once every century. A century of second hand smoke deaths is well over 4 million deaths for the US alone, even higher in Europe.

<comment><USER30> > Yet we do not take drastic measures to prevent these deaths.

We do, actually. A virus like COVID-19 and second-hand smoke are only comparable to a certain degree, though. For example, smoking in public indoor spaces is banned in many, many countries in the world. I'm sure the measures would be even more drastic if inhaling second-hand smoke once could a) kill you within ~2 weeks if your health was already compromised b) cause brain damage within ~2 weeks if you were an otherwise healthy individual.

</comment></comment></comment></comment><comment><USER31> How does economic theory apply to Learned Helplessness?

[https://en.m.wikipedia.org/wiki/Learned_helplessness](https://en.m.wikipedia.org/wiki/Learned_helplessness)

This will continue to happen regularly in countries like Australia over the next few years under their current plan.

</comment><comment><USER28> Why so many of us accept authoritarian lockdown rulings is beyond me. It's even more alarming how willing many are to report their neighbours for perceived infringements. Freedom of movement is sacred and people should be able to make their own choices based on the information available.

<comment><USER17> "your rights end where mine begin" => you can't use your freedom to endanger others

<comment><USER28> If we both wear a mask then we pose very little danger to each other. We pose a far greater danger to others driving a car and having a collision

<comment><USER17> In France for example, there has been ~35'000 deaths because of COVID-19 in ~6 months of 2020, while there has been ~3'500 deaths on the roads in ~12 months of 2019.

Your "if we both" is a very big if => without making it mandatory, people don't wear them and ill people can propagate the virus to many, making COVID propagation possibly more dangerous than a car accident they could create.

<comment><USER28> Making mask usage mandatory and actually policing it would be a much lighter touch and the evidence from Japan suggests the virus can be kept under control without lockdowns. If you take the numbers in Japan in your example, driving is more dangerous

</comment></comment></comment></comment></comment><comment><USER32> In Buenos Aires, Argentina we are in lockdown since middle March. Never stopped.

</comment><comment><USER33> This is insanity. Why are these people letting their government put them under house arrest.

</comment><comment><USER34> [https://www.worldometers.info/coronavirus/country/sweden/](https://www.worldometers.info/coronavirus/country/sweden/)

Sweden has proved that lockdown is total propaganda ran by special interest.

P.S. I am going to get downvoted. But that's okey. People don't want hear truth!

<comment><USER35> Only seven countries have done worse than Sweden[1] in terms of deaths/population. It's worse than the US, 4 times worse than Germany, 95 times worse than South Korea and 1895 times worse than Taiwan. Despite having plenty of advance warning and (wasted) opportunity to learn from what other countries had done.

[1] [https://coronavirus.jhu.edu/data/mortality](https://coronavirus.jhu.edu/data/mortality)

<comment><USER34> Give it a few months. We will discuss about it. Let the those countries have their second wave they will be same as Sweden but with broken economy!

<comment><USER36> The Swedish economy is already suffering. The swedish economy fell by (8.6%) 2nd quarter [1] compared to Denmark (7.4%) [2].

[1]: [https://www.scb.se/hitta-statistik/statistik-efter- amne/nati...](https://www.scb.se/hitta-statistik/statistik-efter- amne/nationalrakenskaper/nationalrakenskaper/nationalrakenskaper-kvartals-och- arsberakningar/pong/statistiknyhet/nationalrakenskaper-2a-kvartalet-2020/)

[2]: [https://www.dr.dk/nyheder/penge/historisk-stort-fald-i- bnp-c...](https://www.dr.dk/nyheder/penge/historisk-stort-fald-i-bnp- coronakrisen-faar-dansk-oekonomi-til-skrumpe)

<comment><USER34> Your conclusion is wrong. Sweden is going to fully open since COVID19 is solved issue now.

Denmark is going to suffer months, not years still.</comment></comment></comment></comment></comment>


How to Raise Trillions for Green Investments - <AUTHOR> http://www.nytimes.com/2016/09/20/opinion/how-to-raise-trillions-for-green-investments.html <comment><USER2> The federal government provides a tax credit for 30% of project cost for solar and wind. Unfortunately, this tax credit is non-refundable, meaning it can only be used to reduce your tax liability.

This effectively means that in order to do large-scale renewable energy projects, you must have backing from a large, profitable company to take advantage of the tax credit. This is called _tax equity_ investing, and it's a big money-maker for giants like Goldman Sachs, Berkshire Hathaway, Bank of America, Google, etc. ROI for tax equity investing is amazing, like 20% annual rates of return. But the entire structure shuts out small players, non- profits, and government entities.

The tax credit is phasing out over the next 7 years, and the hope is that solar will then be profitable enough to be developed without tax incentives. But until then, investment is limited by companies with large tax liabilities.

<comment><USER3> The investment tax credit for solar works as you describe. Wind instead has a _production_ tax credit where the owners get a tax credit for each megawatt- hour produced over the first 10 years of the project's life. The tax credit has been adjusted upward with inflation over time and is currently at $24 per MWh. If you make the reasonably conservative assumption of 20 years' life for a wind project, that's more like $12 per MWh over the project lifetime. Both tax credits are, as you say, only good for reducing tax liability.

New nuclear power in the US, built between 2005 and 2021, gets a production tax credit similar to wind. But it's capped at a lower level -- only 8 years of tax credits at $18 per MWh instead of 10 years at $24, and there's a cap on the maximum amount of eligible capacity. (Though the US is not building enough new nuclear to hit the cap anyway.) These tax credit levels were set up in the Energy Policy Act of 2005; back then nuclear looked a lot more mature and less in need of incentives than solar or wind generation technologies.

I think that investment tax credits are a better system than production tax credits. After a decade we can tell that there's really no danger of investors building an underperforming solar facility just to scoop up tax credits up front. The problem with a production tax credit is that it can generate perverse pricing signals at times of high output and low demand. Both wind and PV generators have negligible marginal costs and will "naturally" bid close to zero prices in competitive markets when demand is low and their output is high. But production tax credits also enable wind generators to bid _less than zero_ \-- "hey buyer, we'll pay you $5 per MWh to take this surplus electricity off our hands, and we'll still make money via the production tax credit." That negative-priced new wind may well be undermining other clean sources, like older wind projects, nuclear plants, or hydroelectricity. Nuclear would still be in financial trouble in deregulated electricity markets in the US even without bouts of negative-priced electricity, because it has relatively high O&M costs even after the capital costs are paid for, but it'd be doing a bit better if not for the bizarre negative pricing that wind produces sometimes.

<comment><USER2> Thanks for correcting me. And agreed about production vs investment tax credits.

It's unfortunate that the first "victim" of renewable energy is going to be nuclear (another carbon-free energy source). The intermittent nature of solar and wind require other energy sources that can be ramped up late in the evening and early in the morning, and turned off at night. Nuclear plants take days to ramp up, so they can't meet this need.

<comment><USER3> I too am unhappy about clean energy fratricide between renewables and nuclear power. (Though I think that _most_ of the financial pressure on nuclear in the US is actually from shale gas; renewable generation hasn't been able to grow as quickly in absolute terms even though its relative YoY growth has been impressive.) If electricity storage gets cheaper and more abundant, that should help nuclear power too. It means that nuclear generators, like renewables, would be able to charge storage at low-price, low-demand times and discharge/sell at times of high demand. That would tend to displace relatively inefficient marginal supply sources based on fossils, like open cycle gas turbines used as peakers, instead of driving infighting between nuclear power and newer low-emissions sources.

</comment></comment></comment></comment><comment><USER4> This article never even mentions the real problem, which is doing good risk assessment. Suppose I'm a bank, and you come to me and ask for $3 billion to build a solar farm. If you work very hard for the next five years, you might (might) turn that $3 billion into, say, $6 billion. Or you could just grab the $3 billion and run, and have more money than you could ever spend anyway. The second option is so attractive that I know lots of people might take it. I could sue to get it back, but that's years of expensive hassle, and a lot of it will probably be gone by then anyway. So I don't make the loan, unless you're an enormous corporation like GE that can put up collateral, and has enough to lose that grabbing and running isn't worth it.

<comment><AUTHOR> Policy is the issue, not risk assessment. I'm not dismissing the need for "good" risk assessment, but that should be a part of any investment analysis. A given.

What's interesting is the objective view that this is something we need to do, as stewards of the environment, as countries, as a civilization, while acknowledging it will be expensive.

This is the beginning of a post-denial era.

It's impressive to discuss opportunities in terms of billions and trillions. I think this presents a tremendous opportunity for the most universal, collaborative solutions.

<comment><USER5> Did you finish any thoughts, or am i just dumb?

</comment></comment></comment><comment><USER6> Its not really new TRILLIONS. Its mostly replacing planned trillions that would have gone to older/carbon-intensive technologies.

So much of this is probably "earmarked" somewhere for a coal station, an ICE truck or whatever. And now has to be switched to a nuclear, solar or other innovative perpetual-motion investments.

So it is an easier task than it looks.

(This is still a massive challenge of course, free riders, unproven technologies, scaling, agency problems, etc, etc)

<comment><AUTHOR> You have it right when you focus on the fact that this is a massive challenge.

The point isn't to create new monetary supply. This money is going somewhere, but how do we channel it to something as fundamental and positive as green investments?

This may look easy on the surface, but of course the devil is in the details. If the money is going somewhere then it will be taken away from somewhere. So, environmental policy must be balanced against economic policy, i.e. higher gas prices because of less in oil subsidies.

What I find promising is that the conversation has evolved beyond, "if we should do this," to "how we must do this."

</comment></comment><comment><USER7> As solar energy costs drop below those of fossil fuels [1], its seems possible that for a few trillion, some kind of sequestration would be possible. One could imagine entire PV farms devoted solely to restoration of the atmosphere to pre-industrial levels, for example. In my opinion, climate change is a problem with an engineering solution.

As a side note, the linked reference is a well argued version of the near future of transportation and energy. Highly recommended

[1] Clean Disruption - Why Energy & Transportation will be Obsolete by 2030 - [https://www.youtube.com/watch?v=Kxryv2XrnqM](https://www.youtube.com/watch?v=Kxryv2XrnqM)

</comment><comment><USER8> There isn't much "How to" in the article. There is a bit of hand-waving about a G20 agreement but the link doesn't really provide any information. What a waste.

<comment><AUTHOR> The "How to," is explicit and it's in the 3rd paragraph, "governments must create conditions that encourage private investment in clean technologies and sustainable development." That's how you raise trillions for green investment.

To reference my own previous comment, you "create the conditions" through policy.

This is not meant to be comprehensive, but it provides some context to the conversation: [https://en.wikipedia.org/wiki/Energy_subsidies#Allocation_of...](https://en.wikipedia.org/wiki/Energy_subsidies#Allocation_of_subsidies_in_the_United_States)

</comment></comment><comment><USER9> I have an idea. How about we actually focus on viable alternative energy, like nuclear and hydro, as opposed to feel-good pipe-dreams, like pervasive wind and solar.

<comment><USER10> I agree - I'd love to see more nuclear power, particularly if we could iterate on the reactor design and build ones that are actually safe and efficient, rather than the 60s and 70s models that we're mostly stuck with. The anti- nuclear power movement is one of the great tragedies of the modern age - instead we doubled down on dirty, toxic coal-burners.

<comment><USER11> We're stuck on unsafe 70s models because _safe_ modern nuclear power plant designs are just not cost effective compared to literally everything else.

It's a shame that coal plants aren't held to the same standards, yes; but I'd rather see both replaced.

<comment><USER12> The 70's models are political compromises. The technology to make nuclear reactors far, far safer has been around for as long as the others have.

And while the up-front cost of a nuclear reactor is going to be more than a solar farm, the amount of energy you'll be creating is orders of magnitude greater.

<comment><USER13> I'll just point out the nuclear power plant Olkiluoto 3 which is well behind schedule and estimated to cost €8.5 billion [1]. Sure, the original price tag was €5 billion lower, but it's just the materialized cost that matters in the end.

[1] [https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#...](https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#Unit_3)</comment></comment></comment></comment></comment>


Ask HN: Recommendations for a great introductory text on Abstract Algebra? - <AUTHOR> <comment><USER2> Dummitt and Foote suggested above is a great text on the subject and probably the best when it comes to a complete treatment of the theory.

The only complaint one could make is that it's written for mathematicians.

A more appropriate book for "lower level" students (in terms of mathematical maturity) would be John B. Fraleigh's "A First Course In Abstract Algebra".

</comment><comment><USER3> Dummitt and Foote</comment>


Ask HN: How do you feel about applications being a web-app wrapped in Electron? - <AUTHOR> I don't like them, but I can't decide why I do not like them. So I'd like to see what the masses think.<p>Note that by "website wrapped" I mean just that - a website, not a website which is necessarily accessibly via internet. So this includes the new Skype for Linux Alpha (which I am assuming is web.skype.com wrapped in chromium. if it is not, just think for now it is for example's sake) but not an application to flash ISOs to USB drives[1] which uses node APIs and native extensions for the logic, and electron mostly for the UI part and JS for driving the UI.<p>[1]: It actually exists: www.etcher.io, but that's just an example. No specific application intended to be pin-pointed. <comment><USER2> Sometimes it's useful to have a separate .app for a website, at least under macOS.

But then Fluid.app solves that problem without the pain of coding up Electron wrapping.

</comment><comment><USER3> I feel good about it. Very good indeed.</comment>