Dissecting a spammer's spam script - <AUTHOR> https://jelleraaijmakers.nl/2016/04/dissecting-spammers-spam-script <comment><USER2> Maybe I'm too naive, but I really don't get why people do this (the spamming, not the dissecting). Whoever did this could probably land a nicely paying programming job, no? Is spamming that lucrative or what's going on?

<comment><USER3> >Is spamming that lucrative or what's going on?

Yes, it is. There's not that many programming jobs where you can easily make 500k+ a year.

For example, if you're phishing for credit cards with VBV info you might very well get $20 or more per card when selling in bulk (or twice that if you aren't). 10000 emails takes a couple of minutes to send and if you get a 1% success rate that's $2000

</comment></comment><comment><USER4> I had a wordpress site hit with one of these attacks years back. I took it apart to see how it worked. It was a pretty messy hack, but I give them credit for working within the constraints they had.

</comment><comment><USER5> I've seen some code from vendors using ZendGuard and kind of wondered how it worked - I'm assuming any dissections of their obfuscation algorithm or code would be served a takedown notice real quick.

<comment><USER6> Zend is more sophisticated than the techniques described in this story. It's at the opcode level.

[http://xcon.xfocus.org/XCon2006/archieves/Darkne2s&A1rsupp1y...](http://xcon.xfocus.org/XCon2006/archieves/Darkne2s&A1rsupp1y-Decode_PHP_Zend.pdf)

Somewhat similar to what Dropbox does to obfuscate their Python client. They provide a custom built python interpreter that uses a non-standard opcode mapping, as well as "encrypting/decrypting" with a key hidden in the code.

<comment><USER7> Why they would not just provide it with no obfuscation though? The essence of their system is the server-side anyways, why bother?

<comment><USER6> Dropbox? My guess is that they are trying to protect the "tray login" thing where the client runs without prompting you for your dropbox credentials, but that's just a guess.

There's an article about the reverse engineering of the client here: [http://www.techrepublic.com/blog/it-security/researchers- rev...](http://www.techrepublic.com/blog/it-security/researchers-reverse- engineer-the-dropbox-client-what-it-means/)

</comment></comment></comment></comment><comment><USER8> That was pretty straightforward. Check this [http://ideone.com/VImf2v](http://ideone.com/VImf2v) :)</comment>


Show HN: I actually read the "Do Elephants Have Souls?" article - <AUTHOR> https://readup.com/@jeff <comment><AUTHOR> Hey, HN!

I'm the cofounder and sole developer of Readup, a social reading platform built around the central tenet that reading an article to completion should be an essential prerequisite for sharing, commenting on or rating it.

The link I shared is to my profile page which shows a reverse-chronological list of articles that I've posted. In order to post an article, one has to read it in our iOS app or in Chrome with our browser extension installed. We measure the exposure time of the words within the device's viewport in order to determine how much of the article has been read.

My motivation for reading the "Do Elephants Have Souls?" article came from the mention of it in the New Yorker article "The Lonely Work of Moderating Hacker News" in which the author cites its posting to HN as an example of what happens when users rush to the comments section without having actually read the article.

Would love your feedback on the product and I'd be happy to answer any and all questions!

Jeff

<comment><USER2> Great post!

I love this: "a social reading platform built around the central tenet that reading an article to completion should be an essential prerequisite for sharing, commenting on or rating it."

In other words: "People can't have opinions on stuff they haven't read."

</comment></comment><comment><USER2> I'm Bill, Jeff's co-founder. That recent New Yorker article about HN also appeared on Readup: [https://readup.com/comments/the-new-yorker/the-lonely- work-o...](https://readup.com/comments/the-new-yorker/the-lonely-work-of- moderating-hacker-news)

Readup is still small. But even with just a few people in each thread you can still feel the difference. On Readup, every comment comes from a person who read the _entire_ article at hand. Let us know what you think! We're all ears!</comment>


Ramsey's Theorem shows complete disorder is impossible - <AUTHOR> http://www.math.grin.edu/~miletijo/museum/ramsey.html <comment><USER2> This is a sensationalist headline. Ramsey's theorem concerns patterns in a simple system, the coloring of edges in a graph. It says regardless of how the graph is colored you can always find a triangle of vertices with certain properties.

This does not mean complete disorder is impossible. It's just a combinatorial argument that says this simple game of coloring edges on a graph has some patterns to it.

But then maybe you're of the mindset that the universe is a complete graph and physics is a color by number game...in which case....oh god, we're all screwed...

</comment><comment><AUTHOR> There is an infinite version of Ramsey's theorem.

Suppose you consider the collection of pairs of positive whole numbers, and each pair is colored either red or blue. Then there is an infinite set S of positive whole numbers such that any pair of items from S are the same color.

In symbols:

P = { (a,b) : a in N, b in N }

C : P -> {0,1}

There exists S an infinite subset of N and c in {0,1} such that for all a in S and b in S, C(a,b)=c.

The proof is quite simple, I use it regularly to boggle 13 and 14 year olds.

<comment><USER3> I figured out the proof on my drive in to work. It is simple.

At all points we're going to have an infinite set of integers to process, a clique of integers whose connections to each other and all of the integers left to process is red, and a clique of integers whose connections to each other and all of the integers left to process is blue. (red clique, blue clique)

We start with all of N as our set, and our cliques are empty sets.

At each point we take the first thing in our set, and remove it from the set. If there are an infinite number of things left in our set that it has a red connection to, then put it into the red clique and remove all things from the set that its connection is blue to. Else put it into the blue clique and remove all things from the set that its connection is red to. This step can always be done and leaves us with 2 cliques (one of which grew by one) and an infinite set of integers to process.

After we do this an infinite number of times at least one of the red and blue cliques must now be infinite in size. And we're done.

<comment><AUTHOR> That's an elegant way to express it - thank you. My method has more of the "TA DA!" about it, and tends to generate a sense of "Gosh!", but I like the quiet elegance of yours.

Nice one.

</comment></comment></comment><comment><USER4> I don't know if Ramsey's theorem really says anything as grand about disorder as Maxwell's demon and the like, but it does express something quantitative about the existence of subsets containing some specific properties as the size of the graph increases.

For me, Ramsey's theory is particularly interesting its rare that an open problem in mathematics can be explained to anyone with relatively little background in mathematics or logic for that matter. Mathematicians have discovered some bounds on R(n), but an exact solution looks like its no where in sight.

</comment><comment><USER5> Rainbow Ramsey's theorem shows that complete disorder is unavoidable as well. :)

</comment><comment><USER6> In other words, when complete disorder is achieved, complete order is formed (since that disorder becomes completly homogeneous).

<comment><USER7> "You know the thing about chaos? It's fair." - The Joker</comment></comment>


Show HN: SongMarkers – An app to make loops and markers for songs on Spotify - <AUTHOR> https://www.songmarkers.com/ <comment><AUTHOR> Create markers in time, then jump to them and / or loop them. Great for learning sections while playing an instrument since it can operate hands-free. Desktop Chrome or Firefox only for now, since that's what the Spotify web playback API supports.</comment>


AWS Launches Simple, Bulk Email Service Amazon SES - <AUTHOR> http://techcrunch.com/2011/01/25/aws-launches-simple-cloud-based-email-service-amazon-ses/ <comment><USER2> Tout (<http://toutapp.com>) uses SendGrid for emails. I'm happy to see some competition in the space, I can now have backup or multiple e-mail delivery providers, which is inherently better for my customers.</comment>


They laughed when I sat down at the piano, but when I started to play - <AUTHOR> http://www.versacreations.net/advertising/165/famous-headline-1-they-laughed-when-i-sat-down-at-the-piano-but-when-i-started-to-play/

<comment><USER2> Tested Advertising Methods, by John Caples (the writer of this headline), is one of the best books you can buy on how to write advertising copy.

<comment><USER3> Make sure you get the 4th edition... the 5th edition is terrible, as most of it was re-written by another author and Caples' famous ads are replaced by "new examples" that are vastly inferior.

</comment></comment><comment><USER4> At the bottom of the page, the article implies that the subject of the ad started to _strum_ the piano, at which point I realized that they had reason to laugh; the subject of the ad was a professional comedian, thus: "They laughed when I sat down at the piano, but when I started to play they _really_ bust a gut!"

So really, this was the story of a total success.

</comment><comment><USER5> The repeated misuse of punctuation when quoting the headline undermines the story.

</comment><comment><USER6> So what was this an advert for? Clicking on the advert itself just gives a 404.

<comment><USER7> Music lessons by correspondence. Here's a working link,

<http://www.powerwriting.com/caples.html></comment></comment>


Static if, resurrected - <AUTHOR> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4461.html

<comment><USER2> I'm not particularly convinced. The make_unique example given could be implemented in a similar manner with existing C++ features, and it would not require yet another complexity-inducing feature into C++:

        #include <memory>
        #include <type_traits>
        #include <utility>

        template<bool Cond>
        struct static_if_impl {
          template<typename F1, typename F2, typename...Args>
          decltype(auto) operator()(F1 f1, F2, Args&&...args) const {
            return f1(std::forward<Args>(args)...);
          }
        };

        template<>
        struct static_if_impl<false> {
          template<typename F1, typename F2, typename...Args>
          decltype(auto) operator()(F1, F2 f2, Args&&...args) const {
            return f2(std::forward<Args>(args)...);
          }
        };

        template<bool Cond>
        constexpr static_if_impl<Cond> static_if{};

        template <class T, class... Args>
        std::unique_ptr<T> make_unique(Args&&... args) {
            return static_if<std::is_constructible<T, Args...>{}>([](auto&&...args) {
                return unique_ptr<T>(new T(std::forward<Args>(args)...));
            }, [](auto&&...args) {
                return unique_ptr<T>(new T{std::forward<Args>(args)...});
            }, std::forward<Args>(args)...);
        }

<comment><USER3> Sorry for being off-topic, but where did you learn to write this solid C++ of yours?

<comment><USER2> I'm not sure if you are being sarcastic, but to be honest I don't really remember. I guess I picked it up over time from here and there. Then moved on to more formal documentation, that is, the standards.

</comment></comment></comment><comment><USER4> What a horrible domain name!</comment>


NASA Now Able to Produce Thin-Film, Flexible Aerogel - <AUTHOR> http://www.core77.com/blog/materials/nasa_now_able_to_produce_thin-film_flexible_aerogel_23248.asp <comment><USER2> This could be really big.</comment>


Leaked Sales Numbers Suggest Amazon Kindle Fire On Track To Outsell iPad - <AUTHOR> http://www.cultofmac.com/120233/leaked-sales-numbers-suggest-amazon-kindle-fire-on-track-to-outsell-ipad-exclusive/?utm_campaign=twitter&utm_medium=twitter&utm_source=twitter <comment><USER2> Amazon is good at retail fulfillment, but they are absolutely brilliant at PR based marketing.

I really think that journalists, when they are called by a PR agent for a firm, should not report what the PR agent tells them as a "leak". "Leak" implies that some employee let the information out against the express wishes of their boss... but this is not what has happened here.

I'm familiar with the culture and organizational structure of Amazon. Only a very small number of people in Amazon would have access to this information, and none of those people would be where they are if they were the kind of person who "leaked" information.

This is a plant.

It is a plant based on the first 5 days of sales of a new product.

A new product that had weeks and weeks of "leaks" including someone putting an actual tablet in MG Sieglers hands. (Tell me it wasn't a PR rep or executive in the company that did that...)

So, Amazon hyped up their new kindle for several weeks, then announced it, and got a bump in sales of the new device right after the announcement.

I wonder how many fewer than average kindles they sold in the weeks prior to that?

Then, cult of mac, a blog who regularly plays fast and loose with the facts, compares those 5 days of sales-- after weeks of hype and right after the announcement-- to the average rate of sales of the iPad, over a much longer period, and concludes that the Kindle is "on track" to outsell the iPad.

Talk about picking only favorable data to fit your conclusion!

Also, shouldn't a device that costs half as much (and does far less, naturally) outsell a more expensive device? Shouldn't you expect a toyota to outsell a BMW, no matter how much extra value the BMW adds? Would you even say the BMW and the toyota are in comparable categories?

<comment><USER3> "Would you even say the BMW and the toyota are in comparable categories?"

I would. They both get you from point A to point B. And for most people, that's what matters.

You are missing the real point here. Most people aren't making a choice between the Kindle Fire and the iPad. Most people are making a choice between a Kindle Fire and some other non-essential purchase (like an extra couple pairs of shoes.)

The Kindle Fire will blow open the market for tablets. It will appeal to an entire set of the population that could not previously afford or justify a tablet.

It will be very interesting to watch development in this space. You have Amazon hitting Apple on the low end, and Microsoft gearing up to hit Apple on the high end with Windows 8 tablets that run regular Windows programs. The iPad is getting some stiff competition.

<comment><USER4> You may get enterprise (and take-home-enterprise) windows tablets in the iPad price area, but they'll be mostly cheaper, like Android tablets are generally prices similar to the phones.</comment></comment></comment>


The Joy of Missing Out - <AUTHOR> https://www.nytimes.com/2018/07/12/style/joy-of-missing-out-summer.html <comment><USER2> I've regained a lot of mental peace once I quit Instagram. When you have hundreds of friends and follow random influencers, you get the impression that every single person is always on a beach in Bali, eating at Michelin star restaurants, riding Lambos and partying with attractive, successful people in the most exclusive venues in exotic locations. In the meanwhile you're a corporate drone stuck in traffic to get to your grey cubicle, dealing with a shitty boss, trying to figure out how to pay rent.

The reality is that those people who FOMO you, don't have that lifestyle. They're simply marketers, but our brains aren't super good at seeing past that. And your friends? Sure, they go to a cool place once in a while individually, but you're just being exposed to hundreds of them all signaling at the same time. Statistically speaking you WILL see your extended social circle doing something cool multiple times a day. This used to be manageable in the 150 person village age. Bob got a new goat, son of a bitch.. oh well. But at social media scale our brains simply can't handle it.

It's analogous to how regular people don't realize just how much Photoshop and photographic skill goes into making someone look as good as they do in magazines and on their IG feed. We look at them and immediately conclude that we're some kind of a sub-human degenerate species compared to them, whereas in reality it's all bullshit.

It feels SO much better to swim in one's lane (basically JOMO), not looking around to see how everybody else is doing, especially when it's not real.

I'm not a religious person, but there's something really powerful in the admonition not to covet your neighbor's spouse, house, animals... which is what I sense my brain doing on social media.

The genius of IG is that it makes people willingly subscribe to hours of marketing every day. Zuckerberg got one hell of a deal on that company, 1 bil for it has to be the greatest deal of the century.

<comment><USER3> Growing up in a Midwestern suburb where obesity was normal, I found the messaging about how our beauty standards are unrealistic and manufactured by Photoshop to be at least sort of plausible. Now I'm quite certain it's not true. Walking down the street in San Francisco, a majority of the young adults I encounter _really are_ slim, muscular, well groomed, and sharply dressed, embodying the "unrealistic, unhealthy" ideals of my adolescence. I wondered if this was just wealth, but it even extends to people in the service sector.

If Instagram lives are unrealistic, they're unrealistic in much the same way as coastal megacities. It's true that most Americans will never live like that. But those people really exist and their numbers are not small.

<comment><USER4> Ask about beauty routines for these people and you'll learn the difference. The urban elite spend a lot of time on exercising, creating food habits, and fashion.

<comment><USER5> We're calling randos walking down the street in San Francisco the "urban elite" now?

The vast majority of people I know who are attractive do not spend a lot of time on beauty regimes and are not gym rats.

</comment></comment></comment></comment><comment><USER6> > Know that you likely have a problem.

> Do you own a smartphone?

> That's it.

I disagree.

I think a better question might be "Do you own a smartphone _and use social media_?"

A lot of the comments I see around this - especially on the comments here on this page - is around feeds from Instagram and Facebook and the like.

Yep - groomed social media posts are an unrealistic view of society. Just like movies and magazines are an unrealistic view of society too. "Man, everyone else is running around blowing up cars and shooting bad guys, but I am just a loser sitting here in the movie theatre." I guess people need to get a literal reality check.

Personally I just turn notifications from email off (and I dont use social media), and have the Do Not Disturb feature in Android on so that only calls & messages from starred contacts (wife etc) makes a noise. Zero issues about feeling like I am being disturbed by my phone. I dont think I am in denial about this...

<comment><USER7> > and use social media?

I'd argue it is not that straight cut. Just like you can tune do not disturb to allow important people to reach you, most social media sites allow fine tuning of notifications (except facebook, they don't give a shit[1]). For example, I use twitter to interact with other developers from around the world, and after configuring twitter to only notify me about interactions with people I follow, I'm never bothered by notifications from it either.

[1]: Perfectly satirised by The Onion: [https://www.theonion.com/new-facebook- notifications-alert-us...](https://www.theonion.com/new-facebook- notifications-alert-users-when-they-not-cu-1819577354)

<comment><USER8> You have a problem if, multiple times per day, you open the feed and just scroll through not looking for anything in particular.

As you mention, it seems like your workflow is very action oriented. You use it to communicate with people. But if you ever find yourself just scrolling through the feed for more than 10-15m per day, then you probably have a problem.

</comment></comment></comment><comment><USER9> I was in deep concentration today working on an assignment, but ironically Apple's Screen Time snapped me out of it. In all their wisdom to get me to use the iphone less, Screen Time notification popped up, bring me back.

Edit: and can't turn it's notification off, it is not in the Notification settings area. I had to turn the Screen Time feature completely off so it doesn't happen again.

<comment><USER10> At my last job they replaced the POTS telephone system that had been around for 30 years with a new POE touchscreen phone. The backlight never dimmed and it occasionally showed an animation.

I wrote an angry ticket about it after about 2 days of having it, and 3 people from the IT department and 2 people from the company that sold us the phones showed up at my desk the next day, trying to figure out if there was something wrong with my phone, because "it shouldn't be that distracting."

The only person who understood why I was pissed was the mid-level tech support guy from the phone company.

I hated that phone so much I covered it in a sheet and only uncovered it if it was ringing.

Similarly, the ringtones were all super obnoxious. When everyone had the same ring you could just tune out the ones that weren't coming from right beside you. The new phones had a huge speaker on the back and the ringtones demanded attention like a klaxon. It was maddening because the phone of someone 3 cubes behind you could get a call and it would be louder for you than it would be for them.

Also, the touchscreen took 3 times longer to use than the old design did just because buttons are faster, you can use them without looking, and the UI was slow to begin with.

I love using new technology, and I wanted a new phone because the old one was _huge_ and took up a ton of my desk, but that phone had the worst UX. I just wanted a phone that did the same thing my old phone could do, maybe with better audio quality. I didn't want a phone that demanded my attention to do things.

<comment><USER11> > I just wanted a phone that did the same thing my old phone could do

This is what happens when the buyer (or cheque signer!) is not a user.

To make a sale, the phone vendors has to bid or propose, and for them to stand out, phone needs features. Whether those features make sense or not probably matters less than whether they "beat" the competitors' feature list.

I wonder if there's a way to delegate to the actual users of tools and equipment, the responsibility of evaluating said tool?

<comment><USER12> Yes there is trivially - give the end user the budget to buy their own. However there are some real logistical disadvantages to that approach as well and frankly many workplaces are far too hierarchally minded to the point of being insulted at the concept of asking the employees what they think.

<comment><USER13> What are the logistical disadvantages? Can't the buyer also take care of logistics?

<comment><USER11> > What are the logistical disadvantages?

if each user chose their own model, then the problem of integrating all the phones into the network and/or calendar system etc may be intractably hard.

</comment></comment></comment></comment></comment></comment><comment><USER14> I idly went to Hacker News, scanned through this article, got to the part about doing things with intention rather than just floating along... which made me realize I was wasting time and so I closed the article. Except then I commented... ok to important things now.

<comment><USER15> You are conditioned. Don't feel bad. Just be aware, and that awareness will hopefully prevent you from doing things you don't want to do in the future. Good Day.

</comment></comment><comment><USER16> "I'm the type who'd like to sit home and watch every party that I'm invited to on a monitor in my bedroom."

-Andy Warhol

</comment><comment><USER17> I'm a bit confused by the CEO of Google preaching for spending less time staring at your screen. Doesn't their company's value depend strongly on this metric? My guess would be that its only for show, but shouldn't the shareholders be angry about a move like this?

<comment><USER18> I would classify it under Corporate Social Responsibility. Any shareholders who would get angry at such a thing must suffer from serious short-termism.

</comment></comment><comment><USER19> It's amazing how tightly our brains can hold onto other peoples' expectations for you.

For the longest time, I couldn't get over my ex. Last time I blocked her out of my life, she was doing these cool internships and immediatly had a "bounce back" relationship and people cheering her career on.

 _Years_ after blocking her out of all forms of communication, and my brain still concocts this idealized, super-successful version of her that I had to triumph over like some twisted video game.

</comment><comment><USER20> The Internet used to be something you had to reach out to, with a dial-up connection, in order to connect to it. Now the Internet is in our pockets, follows us everywhere and nags us with nonstopping alerts.

Alerts is what creates addiction. They are rewarding/interesting only sometimes, like a slot machine.

Just disable most or all alerts. Every time you get an alert, consider if you want a similar alert in the future. If the answer is no, disable it.

<comment><USER21> This is really easy to do now on Android. Just long press the notification and you can just flip the notification toggle. The real problem though is people passively accepting their phones defaults. Users need to be educated somehow that it's in their best interest to actively curate their notifications, or better yet, put the onus on Apple/Google. What if the default for the first run of an app was to prompt you if you want notifications or not? That would certainly get rid of some cruft.

</comment></comment><comment><USER22> I extrapolate this to the need for slow transport.

<comment><USER23> I do think that slower transportation helps.

Cyclists tend to be more patient than drivers, based on my (biased) observations. As a transportation cyclist I don't really understand the mindset of many drivers. Their apparent need for instant transportation seems to override safety concerns, particularly the safety of others. Often drivers aren't much faster than I am, particularly given the number of stop lights on my commute. Many cyclists have pointed out the irony in how a dangerous driver who nearly runs over a cyclist often sits at the next stop light with the same cyclist stopped right behind them.

My guess is that cyclists are more patient due to both selection effects (more patient people are more likely to become cyclists) and driving actively decreasing patience.

<comment><USER24> > Cyclists tend to be more patient than drivers

Given the amount of cyclists I see blow thru red lights and stop signs every day, I'm not exactly sure I can agree with this.

<comment><USER25> When you have to generate your own kinetic energy, that's not due to a lack of patience as much as trying to minimize the amount of exertion you must do.

<comment><USER26> So breaking the law and endangering pedestrians is ok if it means you don't have to work as hard? As a pedestrian, I HATE cyclists. At least drivers seem to understand what a red light means. I've never been hit by a car, but I've been hit by plenty of bicycles who should have stopped at that pesky red light.

<comment><USER23> Let's be clear: you should dislike law breaking cyclists, not all cyclists.

As a cyclist who does not run red lights, I dislike that many people seem to think I am responsible for and/or should be punished for the actions of cyclists who do run red lights.

Plus, I suggest paying more attention to cars. The number of times I have seen drivers run red lights is definitely not zero.

<comment><USER27> To be honest, some red lights are just pointless for cyclists. One example are pedestrian crossings with no pedestrian in sight, another are very small crossings (maybe even at night) where you can see anyone coming half a mile away, with nobody in sight.

I also hate the one where you're supposed to wait 2 light cycles instead of 1 for turning left. That is a major road so people usually follow the rule, but it's not good. At the same time the city advocates doing that twice on both sides of the bridge so you can cross at the proper side on the shared sidewalk and not ride against the (often non-existent) flow on the other shared sidewalk. Of course people still do it.

<comment><USER23> I agree that many red lights don't make sense for cyclists in an ideal world. But given the double standard being applied to cyclists, I don't want to give hateful people any more excuses.

In Austin, TX, they added signs to certain intersections saying that cyclists can use the pedestrian signal. In effect, this means that cyclists can often legally run a red light. Unfortunately I fear that some drivers don't pay attention to the signs and will think basically 100% of cyclists are illegally running the red light at these intersections. So I usually will wait for the green light, even in this case.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER28> I enjoy good blackout. Especially in the late evening/early night. Lighting up candles. Looking out of the window at people doing the same.

Having only limited battery life that I should probably not use up anyways and having absolutely nothing to do.

</comment><comment><USER29> I wrote SlowNews[1] in part to deal with the continuous influx of (addictive) content.

[1] [https://github.com/srid/slownews](https://github.com/srid/slownews)

</comment><comment><USER30> >The moments that we're spending on our computer checking email slowly accumulate to hours and days, time we're not spending living our lives.

Well, if I didn't freak the ____out when I read this sentence. Time to do some journaling and go to sleep.

<comment><USER31> But first quickly write a Hacker News comment!

</comment></comment><comment><USER32> Hum, I don't think the FOMO is linked to Internet usage, but real life things. We do social media to kill time, not because we FOMO.

<comment><USER33> > _I don't think the FOMO is linked to Internet usage…_

Evidence suggests otherwise: [https://www.sciencedirect.com/science/article/pii/S235285321...](https://www.sciencedirect.com/science/article/pii/S235285321730007X)

<comment><USER12> That still strikes me as highly silly. I mean people have always been afraid of missing out. From the tabloids, gossip, to the land-line era complaints about teenagers and phone bills. It is at most a slight exacerbator with the information flow in a similar way to group think and selection biases.

<comment><USER34> It's the dose, not the substance, that make the poison.

Because of the smartphone, social media is always with you, everywhere you go, and there is infinite content. That makes it pretty different from all the types of media that came before.</comment></comment></comment></comment>


The Unquiet Slumbers of the Apollo Moonwalkers - <AUTHOR> http://www.americaspace.com/?p=84406

<comment><USER2> I've slept in a sensory deprivation tank several times. It's pretty trippy...you spend a lot more time in REM state and your dreams dance the line between dreams and hallucinations as a result.

</comment><comment><USER3> I like that they were playing Patsy Cline on the tape deck.

<comment><USER4> I just realized that I had Patsy Cline playing in my head since I read that line.

</comment></comment><comment><USER5> I'd always wondered what it would be like to sleep in a gravity a fraction of that of Earth's - whether or not it would be more or less comfortable. Sounds like it actually would be more comfortable, had the astronauts had accomodations more equivalent to those on Earth.

<comment><USER6> You can try it. Put on a wetsuit and a mask and sleep underwater.

Or use a Sensory deprivation tank, you can get access to them commercially. You can even use a heater and a bathtub to makeshift one.

<comment><USER7> Not quite; while the net downward force on your body is indeed less underwater, the pressure on all sides is greater. In particular, if you are at rest, the force pressing on your underside is equal to your weight _plus_ the weight of the column of water pressing down upon you. (This force is indeed what keeps you afloat!)

The experience reported by these astronauts is that of the pressure underneath them being less. I can think of no way to simulate this on earth, save napping in near-freefall (e.g. while parachuting, or while on the Vomit Comet). This does not strike me as a sound idea.</comment></comment></comment>


Show HN: Levenshtein dictionary – string matching to sort+animate the dictionary - <AUTHOR> http://internetveterans.org/dictionary/

<comment><USER2> This is awesome !</comment>


Don't Come to the Dark Side - <AUTHOR> http://www.dau.mil/pubscats/ATL%20Docs/Sep-Oct11/Ward.pdf <comment><USER2> While I enjoyed this article, it feels like the author has setup a strawman specifically so he could tear it down. I've never heard anyone say they wish they could have Darth Vader as a PM.

Also, at what point is project considered a "Death Star"? Does the Apollo program fit into this category? We only went to the Moon a handful of times, but I wouldn't consider that to be a waste of resources. Are we to never attempt engineering on a scale that dwarfs our current capability?

<comment><USER3> I have heard of similar - people wanting an asshole to push things through. Maybe I've spent too much time around big banks.

</comment></comment><comment><USER4> Interesting article, but completely missing the point of R2D2 in movie.

I know because when I was in 4th grade I wrote an essay for a school assignment which was supposed to be about your role model and who do you want to be like when you grow up. And mine was about R2D2. And it was not because of his operational characteristics, but because of his human ones.

I got laughed a lot at for it back then, but looking back at it now it makes perfect sense. From all the characters in the movie, R2D2 is the only one who is completely selflessly dedicated to helping others. He is also very brave, and at the same time has feelings and compassion. If you didn't pick that up form the movie, watch them again. He also does not just execute orders. He can think for himself. And even has a sense of humor. R2 was Lucas's top hero, DESPITE his purely functional and minimal design, and because of his BRAVE and PURE HEART. It seems like his unassuming appearance and attitude fooled more than a storm trooper.

<comment><USER5> ... you should submit your 4th grade essay to Dau.mil. Apparently this is the level of research they are looking for.

</comment></comment><comment><USER6> _All_ of the examples in this essay come from Star Wars. Sure, it's funny, but the problem with a policy piece based entirely on fictional events is that you can freely conclude whatever you want. "This is the kind of thing, that, properly interpreted, _might_ happen" just has much less weight than even "this happened once".

That said, I did love this quote from the article (and it seems the editors did too):

> More than one writer inexplicably complimented Vader's leadership style, > conveniently overlooking his use of telekinetic strangulation as a primary > motivational approach.

</comment><comment><USER7> This deserves a much, much better title. It's engaging, accurate, and made me think about a few things. Others will dismiss it as trivial - I think it's worth the two minute read.

<comment><AUTHOR> I would have liked to add a short better description in parentheses, but I guess this is frowned upon, isn't it?

</comment></comment><comment><USER8> When it comes to large military projects, I'm not sure that these "failed" projects are really failures.

Maybe the real goal of these projects isn't to make us safer. Perhaps it is just a way to funnel taxpayer money to certain interests. If the latter is true, these projects may be viewed as tremendously successful.</comment>


Multiple DNS providers were attacked to take down Tutanota / Attack on privacy - <AUTHOR> https://tutanota.com/blog/posts/ddos-dns-attack <comment><USER2> This is a bummer, I really like their service -- especially for the price! Glad to see they were able to resolve the issue.

</comment><comment><AUTHOR> In recent weeks, Tutanota has been under pressure from repeated DDoS attacks.</comment>


UN Security Council rejects US proposal to extend Iran arms embargo - <AUTHOR> https://edition.cnn.com/2020/08/14/politics/us-un-proposal-iran-conventional-weapons-rejected <comment><AUTHOR> Russia and China opposed and 11 other countries abstained</comment>


Student Solves Sol Lewitt Drawing Assignment in Pseudocode - <AUTHOR> http://cmuems.com/2013/a/golan/09/02/melanie-nailed-it/ <comment><USER2> He's really quite shameless and condescending about singling her out for praise and elevating her above all of the other students:

> Melanie Nailed It

> (diagrams showing wrong answers of other students)

> (diagram labeled with "Lewitt" and "Melanie")

> If I were Pace Gallery, I know whom I would hire.

> each of the corners of Lewitt's quadrilateral was reliably located by about > a quarter of the students

> marvelous pseudocode system

> As far as I'm concerned, Melanie has earned the right to title her > pseudocode as she did [SOLLEWITTFUCKYOU]. This document is really a gem

> (entire homework answer)

ick ick ick. It's like when a teacher photocopies your essay and hands it out to everybody else in the class as an example of stellar writing, except now it's on the internet.

<comment><USER3> What pedagogical purpose does this serve? I'm a fan of tough love from teachers. I'd rather get a low grade and learn a great deal than a high grade and learn nothing. For some instructors, part of that is being willing to say the equivalent of "this is complete shit" when your work is, in fact good, but not up to standards.

But the best ones do it in private, or in written feedback, or generally to everyone as a motivational tactic. All of that I'm willing to tolerate, and I've seen some (not many) user acerbic brutal feedback to achieve results out of me I'd never find possible.

But never have I seen a teacher signal out particular students, compare their work openly, while holding up other particular students as examples of what not to do.

Is that good or bad? The principle of rewarding individual excellence is good, and the attitude could even be forgiven in certain circumstances.

But there's a way to do that without being a dick. And if you're going to be a dick, you better b the extremely rare person that knows how to be a dick properly and effectively, usually with an undercurrent of good humor and in the pursuit of ultra-high standards.

<comment><USER4> Keep in mind: This class is part of a conservatory-style BFA program. These students are already, or will soon be, custom to public critiques. And learning how to accept public criticism, positive and negative, is explicitly a goal of many such programs.

My two cents: While I would have hated such a thing in an engineering class, I really appreciated public discussion and criticism of my work in the arts. I found that such transparency, even when painful, was hugely valuable to me as I grew as an artist.

<comment><USER3> Yes, that's a good point. I've certainly never examined the problem through the lens of a BFA conservatory-style program. If a necessary part of the skill-set a student wishes to learn is the ability to accept and process public criticism, it certainly makes sense to emulate that in the classroom.

</comment></comment></comment></comment><comment><USER5> I ran OCR over the text (using the first website I could find that takes image urls directly), so you don't have to.

A quadrangle which is formed and enclosed by four lines, the first of which is drawn from a point halfway between a point halfway between the center of the wall and the upper left corner and the midpoint of the left side and the upper left cor- ner to a point halfway between the midpoint of the top side and the upper right corner, the second line from a point halfway between the start of the first line and a point halfway between the midpoint of the top side and the upper left corner to a point halfway between a point halfway between the center of the wall and the lower left corner and the mid- point of the bottom side, the third line from a point halfway between a point halfway between the start of the first line and the end of the second line and a point halfway between the midpoint of the left side and the lower left corner to a point which is on an axis between the lower left corner to a point halfway between the midpoint of the right side and the upper right corner where a line drawn from the center of the wall to a point halfway between the midpoint of the right side and the lower right corner would cross that axis, the fourth line from a point equidistant from the end of the third line, the end of the second line and a point halfway between a point halfway between the center of the wall and the midpoint of the bottom side and a point halfway between the midpoint of the bottom side and the lower right corner to a point halfway between the start of the second line and a point where a line would cross the first line if it were drawn from the midpoint of the right side to a point halfway between the midpoint of the top side and the upper left corner.

-Sol LeWitt, 1974

<comment><USER5> BTW, the text as given on the page is incorrect and cannot be parsed. It also doesn't match the solution.

</comment></comment><comment><USER6> I can't fully parse the first point of the first line, the part in quotes below. I have added parenthesis on the parts that I can parse:

... from "a point halfway between (a point halfway between (the center of the wall) and (the upper left corner)) and (the midpoint of the left side) and (the upper left corner)" to ...

There are 4 points and only two operators, i.e., "a point halfway between". The pseudocode given has used three "halfway between" operators on these four points (on lines 5, 7 and 9). I don't know how that interpretation was arrived at.

<comment><USER7> The first line is given in the text as: "... first of which is drawn from a point halfway between a point halfway between the center of the wall and the upper left corner and the midpoint of the left side and the upper left corner to a point halfway between the midpoint of the top side and the upper right corner".

Given that the line has a FROM and TO point, we can extract those:

      FROM
        a point halfway between a point halfway between the center of
        the wall and the upper left corner and the midpoint of the left
        side and the upper left corner
      TO
        a point halfway between the midpoint of the top side and the
        upper right corner

The "halfway between" in each FROM and TO part must specify two points to be between, so we can extract those:

      FROM
        a point halfway between:
          1. a point halfway between the center of the wall and the upper
             left corner and the midpoint of the left side
          2. the upper left corner
      TO
        a point halfway between:
          1. the midpoint of the top side
          2. the upper right corner

We do this once again for the nested "halfway between":

      FROM
        a point halfway between:
          1. a point halfway between:
             a. the center of the wall
             b. the upper left corner
             c. the midpoint of the left side
          2. the upper left corner
      TO
        a point halfway between:
          1. the midpoint of the top side
          2. the upper right corner

This results in a nonsensical parsing ("between" can't have three parameters), so we need to backtrack and reconsider other options. This is English and unfortunately the specification isn't precise. The only one that makes sense is therefore:

      FROM
        a point halfway between:
          1. a point halfway between the center of the wall and the upper
             left corner
          2. [a point halfway between] the midpoint of the left side and
             the upper left corner
      TO
        a point halfway between:
          1. the midpoint of the top side
          2. the upper right corner

This yields the final definition of the first line:

      FROM
        a point halfway between:
          1. a point halfway between:
             a) the center of the wall
             b) the upper left corner
          2. a point halfway between:
             a) the midpoint of the left side
             b) the upper left corner
      TO
        a point halfway between:
          1. the midpoint of the top side
          2. the upper right corner

I leave this as an exercise to the reader to parse the English using greedy vs. non-greedy regex statements and see which one results in the correct outcome.

<comment><USER8> I came to the same conclusion.

Now I'm expecting someone to make a parser/interpreter and a Sol Lewitt image encoding format using the genetic algorythm that turn images into semi transparent polygons :).

<comment><USER8> Well I was a bit borred today, I made the Parser/Interpreter part, I can turn the instructions to a SVG document:

[https://github.com/guillaume86/SolLewitt](https://github.com/guillaume86/SolLewitt)

</comment></comment></comment></comment><comment><USER9> I love the filename: SOLLEWITTFUCKYOU

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

</comment><comment><USER10> FOURTH LINE is missing a colon and there are dashes missing all over the place! That pseudocode would never compile!

<comment><USER11> Well, as I like to say, pseudocode is for pseudoprogrammers

But in this case it it appropriate

</comment></comment><comment><USER12> That's just a normal school day at Carnegie Mellon University. :)

<comment><USER5> She just analyzed the syntax tree of the sentence. Where I'm from, that's a normal school day in middle school. Of course this is a long and convoluted sentence, but the process is not more complicated, it's just longer.

<comment><USER13> Anything sounds trivial if you start the sentence with '(S)he just ...'. And you say that as though a few dozen bright students didn't fail to accomplish the same task.

<comment><USER5> They failed because the instructions are incorrect and cannot be parsed (assuming, as is reasonable, that they were given the instructions seen in the blog post). It's quite possible that the only student who succeeded did so because she misread the first sentence in just the right way. Note that the assignment has "the first of which is drawn from a point halfway between a point halfway between the center of the wall", while the student's version repeats "halfway between a point" twice, which makes the sentence parseable.

What really surprises me is that nobody reported the mistake to the professor.

<comment><USER14> > What really surprises me is that nobody reported the mistake to the > professor.

I think someone else in the class did:

> Michelle has asserted that the statement, as it appears in the Pace > catalogue, only makes sense when an additional phrase is added.

Which linked to: [http://cmuems.com/2013/a/michelle/08/29/quadrangle/](http://cmuems.com/2013/a/michelle/08/29/quadrangle/)

</comment></comment></comment></comment></comment><comment><USER15> Worth noting that Lewitt had draughters construct his work from instructions, as the students have done in this task.

I've stood in a gallery and followed a different Sol Lewitt location drawing before and it had a similar error - an instruction missing.

I wonder, then, if these are deliberate omissions on the part of Lewitt?

</comment><comment><USER8> Here's an Irony Grammar [1] that can parse the proposed problem if the missing "a point halfway between" is added. And a screenshot of the Grammar Explorer [2] for the lazy ones.

It was fun to write :).

[1] [https://gist.github.com/guillaume86/6423775](https://gist.github.com/guillaume86/6423775)

[2] [https://dl.dropboxusercontent.com/u/177896/SolLewitt.PNG](https://dl.dropboxusercontent.com/u/177896/SolLewitt.PNG)

</comment><comment><USER16> Could someone who understands art elaborate on why both the original work and this are important?

<comment><USER17> The classic description of this kind of thing is "the idea becomes a machine that makes the art", which is what Sol Levitt said about his work. It's a conceptual art strategy: instead of being about subjectivity, skill or the personal will of the artist, this kind of artwork is about rationality, objectivity and a neutral, abstract kind of mental process. Nothing particularly special about the pseudocode but it comes from Golan Levin's class: he is a a leading algorithmic artist (using code to make visual art). Lewitt's work could be seen as a forerunner or incunabulum in this field. [http://www.moma.org/learn/moma_learning/themes/conceptual- ar...](http://www.moma.org/learn/moma_learning/themes/conceptual-art/sol- lewitt-and-instruction-based-art)</comment></comment>


The Enemy Within (Conficker Worm) - <AUTHOR> http://www.theatlantic.com/magazine/archive/2010/06/the-enemy-within/8098/1/ <comment><USER2> This is a pretty good article, written for the lay person. There are, however, a few cringeworthy bits; for example secure hash functions are confused with data encryption.</comment>


New Abbott SARS-CoV-2 antibody test has 99.90% specificity and 100% sensitivity - <AUTHOR> https://jcm.asm.org/content/early/2020/05/07/JCM.00941-20 <comment><USER2> I took this antibody test through LabCorp on Friday and tested positive. I have been in strict (see: paranoid) isolation with one other person since March 7 and haven't felt sick or anything close to it since then.

I did have what I thought was a strange flu/cold early February with a sore throat, post-nasal drip, wildly varying body temperature, and lower back pains. In hindsight those are COVID-19 symptoms.

the person I live with took the same Abbott Architect antibody test from LabCorp today so that we can compare results and hopefully eliminate any false positives.

more info on the test: [https://www.corelaboratory.abbott/us/en/offerings/segments/i...](https://www.corelaboratory.abbott/us/en/offerings/segments/infectious- disease/sars- cov-2?fbclid=IwAR2lTmGoOE89ddmQKP2Kxr0kCOF1D0uUI3Xs5NHiJbXZRIIPCwW3yqotIR8)

FDA article from 05/07/2020 on serology test performance including the Abbott Architect from OP: [https://www.fda.gov/medical-devices/emergency-situations- med...](https://www.fda.gov/medical-devices/emergency-situations-medical- devices/eua-authorized-serology-test-performance)

<comment><USER3> Good anecdote. I also had a "weird cold" in February with symptoms that are unusual for me but typical of COVID-19, and have been waiting to get the antibody test. I kind of expect it to turn out the same way. (Otherwise, I would really like to figure out what the "weird cold" that everyone had in February was. Because it sure was weird, and everyone I know had it.)

<comment> y-c-o-m-b "Weird cold" in February checking in. I did not have any temperature variations or fevers, but I got struck with a fatigue like no other. For the first time since I was 3 years old, I took afternoon naps three days in a row because I was just completely wiped out. It's rare for me to take a nap at all (happens maybe once a year)! It took two weeks to get out of this fatigued state. My other symptoms were "chills-like" sensations throughout the day, post-nasal drip and burning feeling in my chest/lungs but very minimal cough. My child did have COVID-19 symptoms back around Feb/March (can't remember exact time-frame) and I even wrote about that here on HN. Maybe I should take this test.

I still think there's a possibility this virus was already in the US before 2020. I don't think they ever found a cause to the "mystery respiratory virus" in Virginia from July 2019:

[https://www.nbcwashington.com/news/local/health-officials- to...](https://www.nbcwashington.com/news/local/health-officials-to-give- update-after-respiratory-illness-sickens-dozens-at-virginia-retirement- community/135890/)

> Three people have also died, but Dr. Benjamin Schwartz of the Fairfax County > Health Department said Wednesday afternoon that those who died were "older" > and had complex health problems. Officials don't yet know the extent to > which the respiratory illness contributed to their deaths, he said.

<comment><USER3> I agree with you on being open to thinking that COVID-19 arrived earlier than was initially thought. When I first shared my "weird cold" story on HN, the consensus was that I was a crazy person and there was no way that could be COVID-19. There would be more deaths if it had been here. But now there are some deaths, and a large number of people with "weird cold" stories, and it really makes me think that a lot of people have already had this. Maybe the doctors at the time didn't recognize it as COVID-19 (I didn't when I had my weird cold). Maybe the numbers that we see now are just wrong; i.e. the recorded cases we have are just the tip of the iceberg (and if you tested everyone every week, we would have hundreds of millions of cases).

Or maybe that weird cold was just a weird cold and nothing more. It seems unlikely to me, but I'm open to it. I hate to make public policy suggestions on anecdotes... but someone should really look into that weird cold. Everyone in New York had it. It sure is weird.

<comment><USER4> people say that because .25% of the population in NYC are dead from covid. we dont see those numbers here -- if it was widespread in feb, what caused the discrepancy?

<comment><USER3> I guess we need to know the total number of cases to figure out what the deaths mean, and until everyone has gotten an antibody test, we can't know that total number.

To make the numbers work for the "weird cold" in early February case, I guess we have to work backwards. Assume that when we went into lockdown was the actual peak, 8 million people in New York City had COVID-19. That means that there is one death for every 500 cases. Then we have to pick a reproduction rate, which I have no idea how to pick, so I'll say that it increases by 1.5x every day (so on day one you have x cases, then on day 2 you have x + 1.5 _x, then on day 3 you have x + 1.5_ x + (1.5)^2x, etc. Going back a month from March 20 (which is approximately 30 days, and when a lot of people report their "weird cold"), that would mean we'd expect around 8 million / 383500 = 20 cases on Feb. 20. With 1 death per 500 cases, you'd have 0 deaths at that level.

I know I've pulled these numbers out of my nether region and so they are likely very wrong. But with some back-of-the-envelope math, I think we can have some sick people in February without a lot of deaths.

Obviously my 8 million total cases in NYC number is too high, and the 20 cases on 2/20 is too low for me and my friends to be those cases. But that exponential can be tweaked to make something plausible. If we make it 1.2 instead of 1.5, then we should have had about 7000 cases on 2/20, and that means around 14 deaths. That seems quite plausible to me. So I dunno. There was a weird cold. It's weird. It could mean anything.

I signed up to get an antibody test. 1 test is not data, but it will be very interesting to see the results.

<comment><USER5> 1 out of 421 NYC residents have died, based on today's numbers, and recent serological tests estimated that 20% of residents were exposed. If that's right, then the death rate would be about 1/84, or about 1.2%. But I've seen other claims that the exposure rate in NYC is higher, which would give a lower fatality rate.

<comment><USER6> Don't forget to factor this breaking through to long term care facilities. From the last I looked at this, if it had not hit long term care, the number of deaths would have been low enough that it may have gone undetected longer. (In WA, 92% of the deaths are still folks over sixty! I don't know the numbers for how many of them were in long term care.)

Which is to say, you can't just look at the population death rate and really appreciate just how dangerous this is for older populations. The CFR for over sixty is a staggering 15% in WA. That is ridiculously high and completely masked if you look at all cases.

<comment><USER7> > Don't forget to factor this breaking through to long term care facilities.

If they're not taking any precautions (because there's no knowledge of the virus in the community) then it can spread to those types of facilities very easily. In New Zealand where only 1,500 people have have COVID-19 (likely to be very accurate, 200,000 tests have been conducted) there's already been two outbreaks in nursing homes.

<comment><USER6> Certainly. I am not implying that we should just let it run its course. Just as I would not let any disease we have a vaccine for loose in a nursing home without the vaccine.

I just think the total IFR actually undersells how dangerous this is.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER8> It is refreshing to read a headline about an antibody test that conveys useful information about specificity and sensitivity rates. This really helps to inform about how useful a test could be for serological surveys.

Well done Hacker News.

<comment><AUTHOR> I wrote the headline from information in the abstract.

</comment></comment><comment><USER9> It's interesting -- in the paper it says that the samples they used to assess the sensitivity (it was a different population for specificity) were from people who had (mostly) been elderly and hospitalized, and that they do not know how it would perform in subclinical or asymptomatic cases. I admit being super not-objective about my reading, since I had this test done last week and came back negative despite losing my sense of smell completely in late March - early April (I live in Boston and was exposed to people who tested positive). It will be interesting to see more data on the Abbott and Roche tests on the subclinical / asymptomatic population.

</comment><comment><USER10> I took this test this Friday (Quest Direct) in NYC and tested negative.

In late Feb. I had a 'flu like symptoms' with fever and massive headache for few days. What worried me later is that I had the 'can't taste anything' symptom a week later. No coughing though.

If you read online, you see people swear they had it at some point this winter. So, if you had a 'flu like' symptoms in Feb or early March, perhaps it was just that...

It cost $110 and personally I think it was worth it... (it is a reminder myself to be more careful as I can still get it)...

<comment><USER11> If the government was serious about homeland security and restoring the economy they would be subsidizing testing full boat.

<comment><USER12> The government has made it clear that this is about politics and business, not safety or public health.

<comment><USER13> Not to put too fine a point on it, even if it is about politics and business it's practically crazy not to fully fund these kinds of activities. The ROI is staggering. It's pretty hard to imagine a price tag where it doesn't work out well for you.

</comment></comment></comment></comment><comment><USER14> > We tested 1,020 serum specimens collected prior to SARS-CoV-2 circulation in > the United States and found one false positive

This gives 95% confidence intervals of between 0.0% and 0.5% false positive rate.

<comment><USER15> Okay - I'm going to reveal my statistics ignorance here - but if they did get a false positive, how does 0.0% fall within the range of possibilities (or is that allowing for it might be 0.0499..% or lower?)

<comment><USER16> All of the sibling answers are correct, but ignoring another possibility: that the timeline is simply wrong, and SARS2 was present in the US early enough that the "false positive" is in fact a true positive.

Which can't lead to a "true 0%", since there's no such animal. But it could mean that all of the tests gave correct answers, in the trial.

<comment><USER17> They could be testing this on five year old samples.

<comment><USER18> From the article:

> Specificity samples were derived from de-identified excess serum specimens > sent to our clinical virology laboratory in 2018 and 2019.

So...not five years ago, and it is even possible that a significant number were from late 2019.

</comment></comment></comment></comment></comment><comment><USER19> The sample sizes are too small to claim such high specificity and sensitivity without any error bars.

<comment><USER20> > The sensitivity of the assay from the estimated day of symptom onset for the > 125 patients included in our chart-review study was 53.1% (95%CI > 39.4%-66.3%) at 7 days, 82.4% (51.0-76.4%) at 10 days, 96.9% (89.5-99.5%) at > 14 days, and 100% (95.1%-100%) at day 17 using the manufacturer's > recommended cutoff of 1.4.

> The sensitivity from the date of PCR positivity was: 88.7% (78.5-94.4%) at 7 > days, 97.2% (90.4-99.5%) at 10 days, 100.0% at 14 days (95.4-100.0%), and > 100.0% (95.5-100.0%) at 17 days using the manufacturer's recommended cutoff > of 1.4.

</comment></comment><comment><USER21> There seems to be no analysis of whether these are neutralizing antibodies. The idea of using serology for immunity certificates or "golden tickets" is never going to go well. Even with 99.9% specificity, if the population prevalence is 1%, 10% of positives will be false positives. If in real world testing, specificity is 99% and population prevalence is 1%, then 50% of positives are false positives.

<comment><USER22> Would you or someone else mind expanding on this thought a little? Why does 99.9% specificity mean that 10% will be false positives?

{added: great answers below} well worth understanding this point. In short specificity measures the % of the population tested which had false positives, but doesn't give you the ratio of false positives to positives or the probability that a positive test means you actually have the anti-bodies.

<comment><USER23> Let me give it a try. Suppose we have 100,000 people in a statistically representative town.

If 1% of people have had COVID-19, then that's 1000 people who have had it, and 99,000 people who haven't.

The test has a sensitivity of 100%, which means all 1000 people who've had it will test positive.

The test has a specificity of 99.9%, which means 98,901 of the 99,000 people who haven't had it will test negative; but that leaves 99 people who haven't had it, but test positive anyway.

That gives us 1099 people who look like they have immunity; but only 91% of those people are actually immune: 9% of the people are false positives.

If instead we have a specificity of 99%, then only 98,010 of the 99,000 people who haven't had it will test negative, leaving 990 people who haven't had it but test positive anyway.

That gives us 1990 people who look like they have immunity; but only 50% of them actually do -- the other 50% are false positives.

<comment><USER24> So if I'm understanding this correctly, with this test.

If you test negative, you are clear, guaranteed, no false negatives.

If you test positive, there is a 10% chance it's a false positive.

I guess my follow up question, does a retest of the positive population make that false positive rate drop to 0.1%, or is the reason for false positive significant to an individual and not random chance?

<comment><USER23> > If you test positive, there is a 10% chance it's a false positive.

Well, don't misunderstand -- it's got nothing to do with the test per se, but with the probability that you had the disease in the first place.

The test itself has two probabilities:

1\. If you've had COVID-19, the probability that it will report positive (sensitivity)

2\. If you haven't had COVID-19, the probability that it will report negative (selectivity)

But those probabilities give you a mapping from reality -> test_result. What you want is the reverse of that -- and find the probability from a test_result -> reality. When you do that, you have to factor in the probability that you have the disease in the first place.

If 50% of the population have had COVID-19, then a positive test means a 99.9% probability of having had the virus. If 1% of the population, a positive test means 91% likely you have it. If only 1 in a million people had COVID-19, then the number of false positives would completely overwhelm the number of true positives.

This is sometimes called the "Base rate fallacy": forgetting to factor in the base rate when determining something like this.

It's important for things like, say, systems which automatically detect terrorists at airports. How many travelers at an airport are actually terrorists planning to attack a plane? It's got to be one in hundreds of millions, if not billions. With that low of a base rate, even if you had a system that was 99.999% accurate, the vast majority of people it flagged up would be innocent.

</comment></comment></comment></comment></comment><comment><USER25> It seems like a voluntary test for someone without symptoms is of limited value to the individual (beyond their individual curiosity) since we don't know enough either way about reinfection risk at this point, and the result is not terribly actionable - you can't just walk into stores without a mask because you have a positive antibody test - nobody is going to trust your lab result printout as a reason to avoid public health measures.

But that said, there should be a public health benefit to broad antibody testing to understand the true infection rate, and for that reason alone, seems like tests like this should be covered by insurance or the public purse for everyone - at least in areas with outbreaks or at high risk for outbreaks.

<comment><USER26> People hav held off seeing their parents. If I knew i had antibodies, I'd plan a trip later in the summer to live with them and do all the shopping to decrease the risk of them getting infected.

People with antibodies are the best people to provide services with the at risk population.

<comment><USER27> Parent comment: "we don't know enough either way about reinfection risk at this point"

Are you disagreeing or did you miss that?

<comment><USER28> I think it's pretty a pretty safe guess that given what we know about viruses work, someone who's already been infected travelling to live with parents and do their shopping for them will lead to a net decrease in infection risk.

</comment></comment></comment></comment><comment><USER29> Cool, it's nice to see progress on antibody tests - the early Chinese ones in use here in Czech Republic are reportedly (accordingly to local news articles) rather noisy. Still preaty nice when they work, as you only need a drop of blood & get results in 10 minutes vs sample swabbing & complicated PCR sample processing taking up to a day.

<comment><USER30> A bigger issue than the specificity of the antibody tests is that they're generally not positive until you're nearly recovered. This confines their use to specific purposes (assessing whether someone may be immune, estimating true infection fatality rates, etc).

</comment></comment><comment><USER31> If you live in the UK, you can get Abbott's test from Forth: [https://www.southwalesargus.co.uk/news/18441478.first-to- mar...](https://www.southwalesargus.co.uk/news/18441478.first-to-market- covid-19-antibody-testing-kit-98-accuracy-launched-chepstow-firm/)

<comment><USER32> > All kits can be purchased online with the samples taken in the home or > workplace, before being sent away for analysis.

Is this possible for other EU countries or is the lab analysis/transport limited to UK only?

<comment><USER31> On Forth's FAQ it says: "Our service is available within the UK only, if you live outside this territory you will not be able to buy this test."

</comment></comment></comment><comment><USER33> The authors don't list an affiliation with Abbott. Usually such a paper will have a statement about conflict of interest or competing interest. This paper has none that I can find.

</comment><comment><USER34> Caveat from the discussion:

> It is unclear what the prevalence of antibody is in individuals with > subclinical or asymptomatic infections and how this assay performs in an > asymptomatic population.

</comment><comment><USER35> > Our serological validation was chiefly limited by use of excess serum > specimens from a mostly hospitalized population known to be very recently > infected with SARS-CoV-2.

Basically, this test may not be as sensitive (or patients may not seroconvert as often) with mild or asymptomatic cases. To avoid this problem we should run a two-part study, the first part a PCR test of a large _random_ sample, and the second part a follow-up to measure antibodies. Has anyone heard about a study of this kind that may be in progress?

</comment><comment><USER36> 'Specificity and Sensitivity' are new words that are now going to enter the public consciousness with regards to testing.

Before Iraq War 2, in 2003, absolutely nobody knew the difference between a 'Shia' or 'Sunni' Muslim, and then it became more common knowledge.

It's neat to see how these events shape awareness.

Now every time a Nurse does a test, people will ask "What's the specificity?!" which can be a good or bad thing.

<comment><USER37> Specificity and sensitivity feel really poorly chosen and difficult to remember. You could swap their definitions and the names of the terms would make just as much sense. I much prefer true positive rate and true negative rate.

<comment><USER38> Those named could be confusing to. True positive rate = .95 could be interpreted as, if you get a positive result, that's a 5% chance of a false positive, when the percent chance of the test being a false positive given a positive result is actually a function of the true positive percentage in the population and not innate to the test.

<comment><USER37> That kind of confusion has nothing to do with the terms though, it just requires a deeper understanding of the process and the statistics around it.

</comment></comment></comment></comment><comment><USER39> These stats are generated just a couple weeks after symptoms or PCR test positivity. I'm still wondering how specificity might drop off for much earlier exposures. Anecdotally: people on my Fb feed are getting positive tests they attribute to illnesses they had back in January and February.

(This concern has nothing to do with the benefit these tests have in "real time" testing).

<comment><USER40> Your FB feed results don't seem impossible. First CV-19 death in CA was Feb 6 [1]. That's presumably at least a couple of weeks after infection.

[1] [https://www.nytimes.com/2020/04/22/us/coronavirus-first- unit...](https://www.nytimes.com/2020/04/22/us/coronavirus-first-united- states-death.html)

<comment><USER39> The question isn't whether they're possible, it's whether the antibody tests are reliable that far from the actual incidence of C19.

<comment><USER35> Don't you mean _sensitivity_ dropping off? The way it's phrased sounds like someone is more likely to get a false _positive_ as time passes after... no infection happened?

</comment></comment></comment></comment><comment><USER41> Do these tests measure level of antibodies? Unclear still what correlation is between level and strength of immunity

</comment><comment><USER42> Does anyone know what these tests cost?

<comment><USER43> In the US, they're $119 through Quest Diagnostics. In some areas and with some insurance companies, that cost is fully covered.

<comment><USER44> Do you know that all the Quest tests are mfg. by Abbott? I didn't see that anywhere, they didn't seem to show which test manufacturer you got when you receive results either.

<comment><USER43> The Abbott test may not be used everywhere. I've called them to confirm their labs local to me use the Abbott test and that's probably what you should do if you're looking to get this test. While it does not guarantee that they use the Abbott test in every region, you can see that they reference Abbott in the footnotes for question #3 in their FAQ on COVID-19 testing here: [https://education.questdiagnostics.com/faq/FAQ219](https://education.questdiagnostics.com/faq/FAQ219)

</comment></comment></comment></comment><comment><USER45> Nice! Last year, in July 2019, in Virginia, there were a bunch of strange flu like illnesses, leading to pneumonia, and deaths [1]. When will these people get tested for the antibodies?

[1] [https://abcnews.go.com/US/respiratory-outbreak- investigated-...](https://abcnews.go.com/US/respiratory-outbreak-investigated- retirement-community-54-residents-fall/story?id=64275865)

</comment><comment><USER46> Slightly misleading headline. The test is not new, it's been launched since April and has already shipped 10M tests.

According to [https://abbott.mediaroom.com/2020-05-08-Research-from- Univer...](https://abbott.mediaroom.com/2020-05-08-Research-from-University- of-Washington-Demonstrates-High-Performance-of-Abbotts-SARS-CoV-2-Antibody- Blood-Test)

<comment><USER47> It's new.This is the second antibody test Abbott is launching.

Disclosure: I work for Abbott.

<comment><USER9> Do you know which of the two is being used by commercial labs like Quest now?

</comment></comment></comment><comment><USER48> How can one measure such high sensitivity and specificity rates when no other test has such high rates?

Surely the only way to measure a test is to compare against ground truth data, which can only come from other test processes, and therefore can never reach 100%?

</comment><comment><USER49> The Quest website warns that having the antibodies does not necessarily mean you are immune. Is it really likely that reinfection is possible less than a year after initial infection, or is that just something they have to write as a disclaimer?

<comment><USER38> We just don't know right now. Some antibodies could work better than others, so for some people it could mean yes and for others no. Could be different for symptomatic vs asymptomatic patients. Some antibodies could make the disease worse through ADE. Immunity is probably conferred for at least a couple months since we dont see a huge number of reinfection, but we dont know whether it trails off after a year or two or goes below an important concentration threshold since there physically hasn't been enough time since the start to measure immunity out to a couple years. In general, you're probably fine, but maybe not, and the test could also be giving you a false positive.

</comment></comment><comment><USER50> Great, now please make 100 billion and send a package to every household in the world.

<comment> mh- I believe these require a blood draw.

<comment><USER50> People who have diabetes often do blood tests daily, at home, on their own, drawing a drop of blood from their finger with a lancet. If they can get it down to using a drop of blood, I think people could be convinced to test at least one member of the household daily. That should at least give us enough information to measure spread.

It would be new for most people but it's not unprecedented and I think people would figure it out quickly enough. Conspiracy theorists would ruin it for everyone of course.

<comment><USER51> I'm sure you are aware of story behind Theranos - doing complex tests on a drop of blood is currently impossible.

<comment><USER52> Would there have been a path of honesty at Theranos such that they would thrive in the age of covid-19?

<comment><USER53> That's like asking, "could Enron have been an honest energy company..." sure, with a different board, different executives, different strategy, different technology, different IP, different market sector, and if they sold ice cream cones for fair prices at the local pool.

</comment></comment></comment></comment></comment></comment><comment><USER54> I know everyone is saying that getting reinfected with covid isn't technically ruled out, but is it safe to assume so? It seems very difficult to find a case of someone truly being reinfected.

</comment><comment><USER55> Has anyone reported doing the sampling to determine the prevalence?

</comment><comment><USER53> > _Alternative index value thresholds for positivity resulted in 100% > sensitivity and 100% specificity in this cohort._

This would be true of a coin flip, wouldn't it? "Head means positive, tails means not negative" would be 100% sensitivity and "Tails means negative, heads means you're not positive" would be 100% specificity. So those would be the "alternative index value thresholds."

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

<comment><USER56> You misunderstand. A test that labels everyone positive would be 100% sensitivity but 0% specificity, and a test that labels everyone negative would be 100% specificity but 0% sensitivity. Deciding every case at once by a single coin flip would thus be useless.

As the article says, "A perfect predictor would be described as 100% sensitive, meaning all sick individuals are correctly identified as sick, and 100% specific, meaning no healthy individuals are incorrectly identified as sick." Deciding every case at once with a single coin flip does not meet both critera of a perfect predictor.

<comment><USER53> Not at the same time, but it does if you split it in to two separate tests, each with an "Alternative index value threshold."

</comment></comment></comment><comment><USER57> which is more accurate, a Laboratory-based immunoassays using using serum or RDT blood samples from a finger stick?

</comment><comment><USER58> and for "only" $120 you too can buy it (priced for insurance to pay out but of course many millions don't have insurance/anymore)

[https://questdirect.questdiagnostics.com/products/covid-19-i...](https://questdirect.questdiagnostics.com/products/covid-19-immune- response/b580e541-78a5-48a6-b17b-7bad949dcb57)

(quest uses the Abbott igg)

</comment><comment><USER59> As someone who lives in Boise, I'm angry:

1\. People had to buy this test. It wasn't free.

That means

2\. whoever bought the test were guinea pigs in this study.

And

3\. That fact wasn't being made clear in Crush the Curve.

LabCorp should refund all the tests in Boise immediately.

<comment><USER38> Nobody paid to be a part of this clinical trial. That's highly unethical. People were paying for a different test.

</comment></comment><comment><USER60> This is encouraging. Two negative viral tests and a positive antibody test, and people should be able to get an ID that says they're exempt from movement and mask restrictions. (To discourage faking this, getting that ID should also turn eligibility for the Emergency Care Benefit, since they can work safely.)

There's still argument over how long immunity lasts, but it has to be at least two or three months, or there would already be widespread (large numbers) reports of people getting the disease more than once. So, for now, IDs could be good for three months. They can be extended later as more info comes in.

First step in the US should be to test first responders in NYC. NYC already has maybe 21% antibody-positive people, and those on the front lines are probably higher. Knowing who's immune will be a great relief to them.

<comment><USER61> >>> ..they're exempt from movement and mask restrictions ...

There's a negative repercussion of people around such folks getting a false- impression that masks are not a serious need (if this is in question, that's a different discussion). It also creates a possibility of visible 'haves' and 'have-nots', which can cause trouble.

I think having uniform messaging for movement/masks irrespective of antibody presence will remove variability in response from people.

<comment><USER60> So the ID card goes on a lanyard.

 _It also creates a possibility of visible 'haves' and 'have-nots', which can cause trouble._

Yes. So? Gradually, more people are added, painfully, to the "have' list.</comment></comment></comment>