Caltech Researchers Find Evidence of a Planet Beyond Pluto - <AUTHOR> http://www.caltech.edu/news/caltech-researchers-find-evidence-real-ninth-planet-49523 <comment><USER2> The NY Times covers the story well:

[http://www.nytimes.com/2016/01/21/science/space/ninth- planet...](http://www.nytimes.com/2016/01/21/science/space/ninth-planet-solar- system-beyond-pluto.html)

EDIT: After reading the comments in this discussion, many of which are addressed in the NYT article, I'd say the NYT article is almost certainly worth reading.

<comment><USER3> I just wished they hadn't indicated this new planet is the "ninth planet". Dwarf planets are no less planets than little people are people.

<comment><USER4> > Dwarf planets are no less planets than little people are people.

They certainly are, since they haven't cleared their orbit.

If you're not going to accept the term, then where's the cutoff? Should we count every asteroid in the belt just because they are orbiting the sun?

<comment><USER5> The answer is that Pluto isn't some sort of classification issue.

The proper answer is that Pluto is a planet because of historical reasons (by fiat). By definition, it is a planet, and the asteroids in the asteroid belt are simply asteroids.

From then on, you can apply the rules of a "planet" later on to other bodies, like this one.

<comment><USER4> > The proper answer is that Pluto is a planet because of historical reasons > (by fiat)

I disagree that Pluto should somehow have this distinction. Along with all of the reasons it shouldn't be considered a planet under the current definition, it was only discovered in 1930 so it's not like we've been seeing this dot in the sky since humanity was in caves.

Even if I were to agree, then Ceres should also be considered a planet since it was discovered earlier.

</comment></comment></comment></comment></comment><comment><USER6> We have been looking for a "missing" objects for a while. The nemesis star theory says the sun has a brown dwarf companion. This object would interact with the Oort Cloud instead of the Kuiper belt. But this theory has been pretty much refuted.

This theory definitely looks more promising. Finding eccentric Kuiper belt objects, and aligning them with a missing object seems to be a good bet. Giving the object an orbit should make the search easier, and we will probably have a conclusion one way or another within a few years.

[https://en.wikipedia.org/wiki/Nemesis_(hypothetical_star)](https://en.wikipedia.org/wiki/Nemesis_\(hypothetical_star\))

</comment><comment><USER7> No one's mentioned Tyche yet?

[https://en.wikipedia.org/wiki/Tyche_%28hypothetical_planet%2...](https://en.wikipedia.org/wiki/Tyche_%28hypothetical_planet%29)

In searching for Tyche, the WISE missions ruled out the possibility of anything larger than Saturn (95x the mass of Earth) out to about 10000 AU and anything larger than Jupiter (317x the mass of Earth) out to about 26000 AU. WISE was able to detect objects the size of Neptune (17x the mass of Earth) out to about 700 AU, so it should be possible to find the object proposed by the Caltech astronomers here (10x the mass of Earth at around 600 AU). I don't know if WISE's current condition would allow it to perform such a search, as it's completely out of coolant.

<comment><USER8> Their site at [http://www.findplanetnine.com/p/blog- page.html](http://www.findplanetnine.com/p/blog-page.html) addresses the areas the Tyche survey and other surveys cover.

My TLDR:

* The WISE survey might only find Planet X at it's nearest approach. Kevin Luhman has redone the survey using the most sensitive WISE bands that only cover a narrow area of the sky and hasn't found Planet X.

* They reviewed the Catalina Sky Survey and eliminated most of the areas they'd expect Planet X.

* The Pan STARRS site survey didn't find Planet X.

Conclusion: Planet X is at aphelion, difficult to find with the Milky Way as a (stunning) backdrop.

I just found their paper: [http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22](http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22)

I wonder how their conclusions match with David Nesvorny's paper predicting a 5th planet having been ejected from the Solar System: [http://arxiv.org/pdf/1109.2949v1.pdf](http://arxiv.org/pdf/1109.2949v1.pdf)

<comment><USER9> > Planet X is at aphelion, difficult to find with the Milky Way as a > (stunning) backdrop.

I would have assumed that planets are easier to detect when they have a backdrop? That the light can be blocked, partially blocked, bent, .. Isn't that the case?

<comment><USER7> You're thinking about one of the ways extrasolar planets can be detected, when they cross in front of their parent star (transit photometry) or when they're imaged using light magnified or redirected by a massive foreground object (gravitational microlensing). I don't think we have the capability to detect something in this solar system eclipsing a background object (whether that's a star or a galaxy or whatever else is out there).

<comment><USER10> Correction, rogue planets are detected when their gravity causes micolensing of distant objects (stars), not the other way around.

[https://en.wikipedia.org/wiki/Rogue_planet#Observation](https://en.wikipedia.org/wiki/Rogue_planet#Observation)

Not an astronomer, but my impression is that microlensing couldn't be used to detect objects in our own solar system, but I don't see any reason why eclipsing of distant stars couldn't be used... it would be far too rare to be practical to find a planet, though.

<comment><USER7> Thanks for the correction!

</comment></comment></comment></comment></comment></comment><comment><USER11> Skepticism is warranted, but keep in mind that Mike "pluto killer" Brown, one of the authors, has an impressive track record. He discovered Eris and Sedna.

</comment><comment><USER12> If it holds up, this is fantastic. Given how interesting the Pluto system has turned out to be, I can only fantasise about a potential super-earth system relatively nearby.

However, to be completely pedantic: would this actually be a _planet_? Or still a _dwarf planet_ , despite its massive size? Keep in mind that the definition of planethood is not only that it's large enough to be rounded by its own gravity, but that it has also "cleared its orbit". I get the impression that this would cut through broad swathes of the still-cluttered Kuiper belt, and thus would only qualify as a "dwarf" despite its massive size.

I checked the original papers for references to whether it had cleared its orbit, and couldn't find any. Correct me if I'm wrong?

<comment><USER13> The criteria for clearing an orbit are apparently somewhat involved[1]. It can't just be a matter of no other bodies having the same distance from the sun or Pluto would disqualify Neptune and Jupiter would be disqualified by its trojans. Because the planets in these cases mass so much more than other other nearby bodies those other bodies dance to the planet's tune and aren't counted against the planet in terms of clearing it's neighborhood. But if you look at the large bodies in the asteroid belt or the TNOs then their influence is very much mutual.

It's not entirely obvious if the new body would be a planet under the listed criteria since I don't think we have a good handle on the total trans- Neptunian population. In fact by Soter's µ criteria we might just need a single Pluto-sized object to cross this planet's path to disqualify it.

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

<comment><USER13> I was misremembering Pluto's mass as being 1/10 of Earth's when it's really 1/500th. It would take a large number of TNOs to push this hypothetical object from being a planet to being a dwarf planet.

</comment></comment></comment><comment><USER14> I don't seem to have a grasp of our visibility of our solar system. We can see a number of the planets with the naked eye, a number of the moons with binoculars and a few hundred $/£/€/.. telescope. Yet even with these great big radio telescopes, antenna arrays, Hubble, etc, we seem to be quite unaware of what's in our neighbourhood. Anyone have figures of how much we've surveyed?

<comment><USER15> It's all about distances. The planets we can see with the naked eye are at most 11AU from us (Saturn is at 10AU at aphelion).

For comparison, Neptune is never closer than about 29AU to us. Brightness goes down as the square of the distance. But it gets worse, because that's brightness at given source brightness. Planets don't radiate intrinsically; they reflect sunlight. And sunlight brightness drops off as the square of distance from the sun. Which is to say that even if they were the same size and albedo (they're not), Neptune would appear about 81 times dimmer than Saturn to us. Oh, also (linear) angular size goes down linearly with distance. So if you want to see the two planets as disks of the same size, you need to have a field of view three times narrower, which means you need 9 times as many of them to cover the sky. And if you want the same amount of light gathered, you have to spend 81 times longer gathering it, per the above brightness calculation.

All of which is to say that the time needed to do an "equivalent" sky survey N times further away (within the solar system, where all the illumination is coming from the sun) scales as N^6. And planets do move, so you might still miss one if you survey a place where it's not yet, then take a while to get to where it used to be, such that it has moved. This is why Neptune was found via its gravitational interactions followed by a survey of a small part of the sky, not brute-force observation.

Anyway, back to the topic at hand, the proposed Planet Nine orbits 20 times farther out than Neptune. 20^6 is 64 million. So if we assume we've pretty much surveyed everything out to the radius of Neptune's orbit at some resolution, and then spent about 64000 times as much time surveying stuff out to the distance Planet Nine is proposed to be at, at the same resolution (I doubt we have), then we've probably surveyed about 0.1% of the stuff out there.

I can't tell you what the actual number is, unfortunately, but I suspect the answer is we haven't really done very good systematic surveys out at that distance.

<comment><USER16> Shouldn't it be fourth power of distance (N^4) not sixth? For objects beyond the diffraction limit (i.e., objects whose radius cant be resolved), visibility is determined by total light reaching the observer. Angular size isn't important. (And, if anything, diffusing a fixed amount of light over a larger solid angle makes it _harder_ to see.)

<comment><USER15> If you're just trying to see all the objects, then yes, N^4. But if you're trying to figure out whether they're planets, you need to either resolve disks or take multiple observations to observe motion. I don't have a good feel for how the latter scales with N in practice...

</comment></comment></comment></comment><comment><USER17> There is an awesome summary by Emili Lakdawala at the Planetary Society (as is often the case with such news).

[http://www.planetary.org/blogs/emily- lakdawalla/2016/0120095...](http://www.planetary.org/blogs/emily- lakdawalla/2016/01200955-theoretical-evidence-for-planet-9.html)

</comment><comment><USER18> Link to paper by Batygin and Brown: [http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22...](http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22/pdf)

</comment><comment><USER19> The scales involved are astonishing. If the orbit is correct, less than one year has passed on it since the invention of writing here on Earth.

<comment><USER20> What do you mean? 700 AU it's about 4 light days.

<comment><USER19> "Planet 9" takes about 11 thousand years to go around one orbit.

</comment></comment></comment><comment><USER21> Giant, weird orbit, debate ... there can be only one name. This is Planet X.

Also because X would be 10th discovered planet, a reference that pluto, while not a planet today, was indeed the ninth _discovered_ planet.

<comment><USER22> If you are going by that logic, Pluto was at least the 10th planet discovered and this is at least the 11th. Ceres was discovered before either Neptune or Pluto and spent 50 years as a "planet". It eventually went through a similar reclassification process as Pluto as other similar objects were discovered. The only reason you don't see the same controversy around its classification is because it was recategorized a century before any of us were born.

<comment><USER21> If naming was all about logic then 1/2 the places on earth would need to be renamed. Naming is about emotion, style, history, and personal preference. Even total mistakes (the Giant Squid) are grandfathered through. Galileo named the moons of Jupiter after his sponsors. I just hope this thing doesn't become "X, brought to you by iPhone8".

<comment><USER23> I think you are confusing naming and classification.

<comment><USER21> Something can be called "Planet X" without being classified as a planet. Take "Planet Hollywood". Incorporating planet into the name should at least protect against future reclassification.

</comment></comment></comment></comment></comment><comment><USER24> > Batygin and Brown inferred its presence from the peculiar clustering of six > previously known objects that orbit beyond Neptune.

This raised a big red flag in my mind. This must produce a literally astronomical multiple comparisons problem. Yes they reported sigma = 3.8, but if they didn't do their multiple comparisons correction right (which I am in no position to determine), they're basically reading tea leaves.

If you're not familiar with multiple comparisons, it's kind of like [this]([https://www.goodreads.com/quotes/649893-you-know-the-most- am...](https://www.goodreads.com/quotes/649893-you-know-the-most-amazing- thing-happened-to-me-tonight)) or [this]([https://xkcd.com/882/](https://xkcd.com/882/)). If you look at enough extra-neptunian bodies, some of them are going to be in an odd looking cluster.

<comment><USER25> So I might not have a great enough understanding but isn't 3.8 sigma not high for this kind of announcement (with the current title)? if someone wants to report finding a planet in the solar system ten times the size of Earth wouldn't they do so at more than @3.8 sigma. In particular, the prior is quite low because it would affect a bunch of other astronomical calculations, wouldn't it? So you would want the confidence that much higher....

[http://www.dummies.com/how-to/content/how-to-calculate- six-s...](http://www.dummies.com/how-to/content/how-to-calculate-six-sigma- quality.html)

What I mean is that in human terms, Google says the average man is 5'9" with standard deviation 2.9 inches, then 3.8 sigma (the chances of this happening by chance) are the same as the chances of finding someone 6'8". It doesn't seem unbelievable - [https://answers.yahoo.com/question/index?qid=20101208183308A...](https://answers.yahoo.com/question/index?qid=20101208183308AA4LYym)

If a woman is set up on a blind date and told the guy is 6'8" would she find it like not credible?

My understnading of statistics then is that the idea that there just so happens to be a planet ten times the size of Earth in our solar system is pretty unbelievable. So I'd want the chances of it being an experimental fluke to be lower than seeing a 6'8" guy, anywhere, at any time, in any context. Because I would think that's what happens when you look at enough data.

\- Aren't the chances of this being completely spurious literally exactly the same as a researcher saying "I saw a 6'8" guy somewhere", meaning anywhere, in any context?

Wouldn't you want higher evidence before stating "evidence found for ninth planet in our solar system, ten times the mass of Earth"?

<comment><USER26> I wish people wouldn't downvote you without explaining why you're wrong.

I have zero education in statistics and your comment makes intuitive sense to me so I'd like to learn more.

<comment><USER25> Before your comment, I edited it to be much more civil and less presumptuous, my original phrasing had included "3.8 sigma is fuck-all", I was briefer, more resolute, and had just included my first link. (You can see evidence of my original phrasing if you remove the hedging I added.)

But the downvotes meant I'm probably wrong - rather than delete I edited it to be much nicer so I could find out why I'm wrong.

<comment><USER27> Upvoted for tempering the aggression and because I agree with you. As far as I can tell your interpretations of the statistics are correct. I don't see how an argument can include information stronger than the statistics of indirect detection of the object (without direct detection).

</comment></comment></comment></comment></comment><comment><USER28> This is pretty solid science, even if, as others have pointed out, there's a bit of academic drama-rama and green jellybean stuff going on. In particular, their model made a prediction that they didn't set out looking for, which corresponded to existing observations. And of course, the whole hypothesis is easily testable. While they don't know where the hypothetical planet might be on it's orbit, it sounds like there's a good shot that small telescopes should be able to spot it.

Exciting stuff.

</comment><comment><USER29> More from the folks behind the paper: [http://www.findplanetnine.com/](http://www.findplanetnine.com/)

<comment><USER30> Have to recommend this, especially Konstantin Batygins piece has great narrative.

</comment></comment><comment><USER31> Ah Planet X which is now planet IX with Pluto's demotion :-). I am guessing that you can confirm it by looking for star occulusions. Presumably the planet would blank out stars as it passed between earth and those stars. So would it be possible to find it using existing plates?

<comment><USER32> It is pretty well impossible to discover a planet by occultations. For one thing, in most parts of the sky the density of stars is pretty low. People do study occultations by known distant objects -- that provides some of the best available info on physical size and presence of atmosphere for KBO's. But in most parts of the sky, it is years in between occultations, which last just minutes. You have to be looking in the right place at the right time. And the sky is full of variable stars, so just looking for changes is hard.

</comment></comment><comment><USER33> The biggest casualty of Science this decade has been elementary school dioramas.

<comment><USER34> *dioramas

</comment></comment><comment><USER35> Why wouldn't their calculations be able to suggest possible locations for the planet?

<comment><USER36> They do, and at the end of the press release it says that Brown has begun an observing campaign to find the planet. Unfortunately detecting these very distant objects is very difficult. The light we see from them is reflected light from the Sun, so their apparent brightness goes as 1/r^4, not 1/r^2 like most objects. And because they are so close, there is a strong parallax from the motion of the Earth. THe consequence from this is that the object will actually drift across the image as you are taking it, smearing it out. In order to detect it you either have to take very short images so that it doesn't move too much (in which case you don't get very much light), or have some idea as to the direction of the smear so that you can correct for it. Either way it's a very hard observation to make! Fortunately if this planet is as big as they claim it to be it should be relatively easy to detect compared to Sedna and the other Kuiper Belt objects.

<comment><USER37> Are you sure it's _r^4_ , not _4r^2_?

<comment><USER36> Yes. The solid angle subtended by the planet (and hence the amount of reflected light) goes as 1/r^2, and then the apparent brightness of the reflected light to us goes as an additional 1/r^2. The total dependence is then 1/r^2 * 1/r^2 = 1/r^4.

<comment><USER38> This is a really good physics puzzler.

The key point is that Pluto does not _reflect_ light like a mirror, it _scatters_ light relatively uniformly, causing more light loss to an observer than, say, a mirror that points the reflection directly at an Earth observer.

</comment></comment></comment></comment></comment><comment><USER39> [https://en.wikipedia.org/wiki/Zecharia_Sitchin](https://en.wikipedia.org/wiki/Zecharia_Sitchin)

He believed this hypothetical planet of Nibiru to be in an elongated, elliptical orbit in the Earth's own Solar System, asserting that Sumerian mythology reflects this.

<comment><USER40> A broken clock is right twice a day.

</comment></comment><comment><USER41> If Planet Nine exists I wonder how the astrologers will tweak there models.

<comment><USER42> This is the most important question here.

</comment></comment><comment><USER43> Very cool.

It reminds me about a book I read called "In Search of Planet Vulcan" ([http://www.amazon.com/In-Search-Planet-Vulcan- Clockwork/dp/0...](http://www.amazon.com/In-Search-Planet-Vulcan- Clockwork/dp/0738208892)). Before Einstein, astronomers tried to explain the motion of Mercury by suggesting there might be another planet inside Mercury's orbit.

</comment><comment><USER44> Did anyone else notice that the rendering of the orbits in the article looks strikingly similar to Kerbal Space Program's orbit UI?

<comment><USER45> Or is it perhaps the other way around. Did Kerbel use the same UI as a popular rendering program used by astronomers.

<comment><USER40> Or, third option, "there's only a few decent ways to represent orbits on a graphic".

<comment><USER44> The colour schemes are very similar though. There are many colour schemes one could choose.

</comment></comment></comment></comment><comment><USER46> Reading the article I didn't see a mention of a previously hypothesised fifth gas giant... so here's a link in case anyone's interested or knows something more.

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

</comment><comment><USER47> If true, voyager hasn't left the solar system yet.

</comment><comment><USER48> At WWDC last year one of the lunchtime presentations was by Michael Brown, one of the researchers involved here. He was one of the people who proved that Pluto should not be considered a planet and went over the history of the discovery/classification of planet bodies. He also mentioned that they had _some_ evidence of a planet body beyond Pluto due to its gravitational affect of some of the smaller bodies out there even then. Interesting to see this is finally coming to something! He has the appropriate/amusing twitter handle of [http://twitter.com/plutokiller](http://twitter.com/plutokiller)

</comment><comment><USER49> I'm puzzled by how a planet this big could form in an orbit so distant.

The fact that the material in that region is so spread out and the orbital period of such object is so long matters.

I would love to read some thoughts on that.

<comment><USER50> As mentioned in the article, this planet could have formed closer to the sun before getting thrown out by Jupiter/Saturn.

</comment></comment><comment><USER51> Does it mean Voyager hasn't really escaped Sun's influence yet?

<comment><USER52> Voyager won't escape the Sun's influence for hundreds of years. The "boundary of the solar system" is not the same as the Sun's influence (and, indeed, is somewhat poorly defined, given how many times Voyager has crossed it.)

</comment></comment><comment><USER53> I've been seeing news stories about Planet X for far too long to take any of this seriously, no matter how seemingly trustworthy the news source is.

</comment><comment><USER54> Thanks for the link. There's a course taught on Coursera by one of the CalTech researchers, Mike Brown, if anyone is interested. It's archived but they have kept it open.

[https://www.coursera.org/course/solarsystem](https://www.coursera.org/course/solarsystem)

</comment><comment><USER55> They should call it Pluto.

</comment><comment><USER56> Now only if they name the ninth planet starting with a 'P', my childhood mnemonic "My Very Educated Mother Just Served Us Nine Pizzas" would finally be complete again! :D My suggestion is 'Prometheus' \- sounds tragic and bad ass at the same time!

<comment><USER57> Well that would be consistent with the roman/greek names for planets and large moons. Now we have to find a stronger tie between the theory and the myth. In some article regarding this news I've read that Planet 9 might have ended in its orbit due to encounters with Jupiter/Saturn. Not exactly an eagle eating its liver, but it can be paralled to "the punishment from Zeus(Jupiter)".

<comment><USER56> :) well nicely connected with the punishment story! I would further go and say that we can draw parallels with the Kuiper Belt objects to the eagles "tormenting" Prometheus while he is chained to a "cold, lonely mountain rock" like our new mysterious planet stuck in a dark lonely corner of the solar system!

<comment><USER57> Alright, time to write to IAU with a name proposal!

</comment></comment></comment></comment><comment><USER58> At first I thought this was another one of those planet x articles that talks about some hypothetical planet way out but then I saw that Mike Brown was involved and immediately got really excited. I hope they find something out there and we can send a probe to it in my lifetime.

</comment><comment><USER59> May it receive a name starting with P so that

 _My Very Educated Mother Just Showed Us Nine Planets_

works again

</comment><comment><USER60> > * the putative ninth planet—at 5,000 times the mass of Pluto—is sufficiently > large that there should be no debate about whether it is a true planet*

That's 10x the mass of the Earth, right, or about 3x the size of Neptune?

<comment><USER61> This is the second sentence of the article: "The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth"

</comment></comment><comment><USER62> This is very cool. Along with a visible supernova and a super bright comet, this is one of those things I dreamed about as an astronomy nerd kid.

Though part of me wants to say "Pictures or it didn't happen!"

</comment><comment><USER63> [https://news.ycombinator.com/item?id=9872387](https://news.ycombinator.com/item?id=9872387)

</comment><comment><USER64> For a moment there, I thought of Nibiru :D

</comment><comment><USER65> If this turns out true, that planet needs to be called "Tartarus". :D

<comment> david-given Yuggoth, surely?

</comment></comment><comment><USER66> Niburu!

</comment><comment><USER67> Maybe it's a Death Star?

</comment><comment><USER68> Provocative title for this Caltech press release.

Mike Brown, the co-author of the paper reported here, discovered Eris, a KBO like Pluto, in 2005. This discovery prompted the IAU in 2006 to demote Pluto out of the realm of "planet" into a "dwarf planet".

At the time, Alan Stern's New Horizons mission to Pluto had just been launched, it finally arrived last year. Stern was incensed that NH started out as a visitor to the 9th planet and was going to end up as a visitor to one of many KBOs, and not even the largest one (Eris is more massive).

The quotes given at the time ([http://www.space.com/2791-pluto-demoted-longer- planet-highly...](http://www.space.com/2791-pluto-demoted-longer-planet- highly-controversial-definition.html)) are revealing:

"Pluto is dead." \-- Mike Brown

"This definition stinks, for technical reasons...It's a farce." \-- Alan Stern

For more: [http://www.space.com/12709-pluto-dwarf-planet- decision-5-yea...](http://www.space.com/12709-pluto-dwarf-planet- decision-5-years-anniversary-iau.html)

Stern is visiting Pasadena on a New Horizons victory lap next week. Should be interesting.

<comment><USER69> Small nitpick: "largest" refers to mean radius, "massive" refers to mass (aka weight). Pluto is the second most massive, but it is the largest. (To be fair, it is a very close call: its diameter is only ~25km larger than Eris)

I'm excited to see this story unfold, if nothing else because it's fun looking up the mythological[1][2][3] origins of the names given to new celestial bodies :)

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

[2]([https://en.wikipedia.org/wiki/90377_Sedna](https://en.wikipedia.org/wiki/90377_Sedna))

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

<comment><USER70> Mass isn't weight, it's the amount of matter. Weight is the measure of the pull of gravity on mass.

<comment><USER69> Sorry, you're right. I should've qualified that I meant the colloquial usage of the word "weight".

</comment></comment></comment></comment><comment><USER71> LV-426. Just sayin'.

</comment><comment><USER72> I just want to know if Planet X is covered by human-enslaving robots.

</comment><comment><USER73> This how Qigong found the Clone Planet in Star Wars 2. Although the planet had be erased from the galactic database, it left a gravitational signature on nearby systems.</comment>


4chan: The Skeleton Key to the Rise of Trump – Medium - <AUTHOR> https://medium.com/@DaleBeran/4chan-the-skeleton-key-to-the-rise-of-trump-624e7cb798cb#.kubigqud3 <comment><USER2> Hm why is this getting shilled here every few hours?</comment>


Ask HN: What are some best web security books? - <AUTHOR>

Hi, I'm looking for recommendation of web security books. I need the books to be highly technical and demonstrate by examples.
Meaning - if it talks about csrf attacks it needs to demonstrate how to make this kind of attack by myself as well as how to defend against it.
Any recommendations? <comment><USER2> As far as books are concerned, none that come to mind.

If you haven't already give OWASP a look as they tend to be one of my first ports of call when I come across terminology I don't fully understand.</comment>


A Court Said Au Pairs Deserve Minimum Wage. Some Families Are Protesting - <AUTHOR> https://www.nytimes.com/2020/01/08/us/au-pair-massachusetts-ruling.html <comment><USER2> My sister had an Au Pair for a year. The Au Pair was taken on holidays with them and participated heavily on family life. Even now, years later, they still mail Christmas presents between Germany and Australia. The deal was basically that the Au Pair is included as a family member in every aspect. I feel that once you attach a minimum wage then the Au Pair is now an employee. I also see the opposite argument, where some families are abusing the system to get a low-cost worker.

Do you need to pay minimum wage and still feed them the good food that the family is eating or you can feed them the cheaper employee food? These questions become relevant now.

<comment><USER3> > I feel that once you attach a minimum wage then the Au Pair is now an > employee.

The Au Pair was always an employee - whether you're paying them exploitative wages or not, they're still an employee.

>Do you need to pay minimum wage and still feed them the good food that the family is eating or you can feed them the cheaper employee food?

You never had to feed the Au Pair the same food as the rest of your family, it was just the decent thing to do. I really don't understand this concept where, just because you're no longer exploiting this employee, you now feel that that opens the door to questioning whether you should now be exploiting them as a person instead.

<comment><USER4> Who says paying below our minimum wage is exploitative? Au Pairs' income is almost entirely discretionary. Who else from say, South Africa, can stably earn $800+/month of purely discretionary income by watching a couple kids for 30-45 hours a week? The whole deal is a big step up in quality of life for many. If you raise their minimum pay, you will literally lower American demand for Au Pairs, who are generally happy with their end of the deal.

</comment></comment></comment><comment><USER5> Isn't an easy and reasonable response to this to charge the au pair for rent at the market rate for a single room in the neighborhood in which the family lives.

Room and board is a non-trivial portion of cost of living. Paying minimum wage and providing housing would mean an au pair makes far more than minimum wage when all is said and done.

<comment><USER6> That sort of defeats the whole purpose of what au pair programs are for, which is primarily cultural exchange, not employment. For some reason the article deftly glosses over this. The general rules for being an au pair are: you're under 30 (depends on country of origin and country entering), your native language is different than that of the country you are visiting, and you are unmarried. The foundation of the program is you get free room/board and a small living stipend in exchange for being immersed in a culture and helping out with a family - an au pair is more like an older sibling than an employee. Or is supposed to be. Obviously there are ways a host family can abuse the system.

There are a variety of programs like this (Peace Corps and AmeriCorps come to mind) where young people are provided unique cultural opportunities at the cost of earning little to no money.

Edit: spelling.

<comment><USER7> > au pair is more like an older sibling than an employee

We all know that this is definitely not the case. You can put all sort of romantic ideals into the system. But there is a definite employer/worker relationship and au pair are not just expected to "be part of the family" but to work as cleaners/nannies and chefs. If you want the system to work as you explain it, the au pair should be completely shielded from doing any non- voulentary work at all, and it would be a completely different system.

<comment><USER8> Normal members of the family aren't shielded from doing involuntary work.

<comment><USER7> In the sense that they do not get sent out of the country for refusing to make dinner they are.

</comment></comment></comment></comment></comment><comment><USER9> Au pair is basically the way you hire a nanny if you are middle class and can't afford one. I am guessing that if minimum wage laws apply then the local governments or the feds are going to have to step in and offer some kind of child care support in addition to the childcare tax deductions we already have. It will probably be untenable. That being said you have to be rich enough to afford an au pair already. For example, we thought about an au pair when we rented in silicon valley but they need their own room. This takes you from a 2-bdrm to a 3 bdrm minimum so that's another expense. You have to weigh that cost in with the cost of full time child care as well.</comment>


Show HN: Text your Congressperson (and they'll receive it as a fax) - <AUTHOR> https://github.com/krrishd/text-a-rep-backend <comment><AUTHOR> Some context: This was built for a hackathon + I'm currently using the test API keys for Phaxio intended for testing, so the congressperson currently doesn't actually get the fax unless I swap the keys out for the live ones. It does, however, give feedback as though the fact has been sent, so feel free to try it out.

To me the ideal use case of this would be the pressure tactics employed by orgs like the EFF or ACLU during times of protest. For example, when Net Neutrality was a significant mainstream issue, orgs had tools to reach out to your specific Congressperson to persuade them to vote in favor of Net Neutrality; those tools involved several steps, and from a UX perspective condensing it into one step would create more participation. Plus, physical faxes are pretty hard to ignore.

</comment><comment><USER2> This is a great projcet. One bit of feeeback, it looks like this must be using your phone number to determine location. In my case, my cell number's location is where I lived in 2006, but now I'm in a different state. I think this is probably true of many if not most of my peers as well.</comment>


OpenTSDB – A Distributed, Scalable Time Series Database - <AUTHOR> http://opentsdb.net/ <comment><USER2> OpenTSDB itself is pretty easy to configure, the tsds are stateless and you can spin up some for ingest, some for frontend/grafana etc by blanket applying a small config file. You can use any of TCP, HTTP, or DNS load balancing to handle failure depending on how you ingest. It's easy enough to build packages for, and we recently committed it to FreeBSD ports where you can get a whole up to date HDFS/HBase stack without 3rd party garbage.

The hard part is HBase and to a lesser degree HDFS.. there are just a lot of things to read and learn about, and failure to address one of them will eventually cause interesting struggles. That said, my company looked at the field in 2012 and chose OpenTSDB, and it's handled things well enough considering fairly poor configuration of HBase. We recently reevaluate the space and tried Influx and Karios. Influx fell on its face in several ways that will take years to fully iron out, Kairos trades one set of evil for another, so we decided to do some learning and redeploy OpenTSDB correctly. As far as open source options, it's far ahead in the battle hardened department.

If you want to consider it, I would advise checking out some of the slides/videos on [http://www.hbasecon.com/](http://www.hbasecon.com/) \- these two being the most critical:

* OpenTSDB and AsyncHBase Update

* HBase Performance Tuning @ Salesforce

HBase seems pretty vibrant. There's been a lot of progress with things like WAL shipping and performance tweaks like SSD block caching, off GC heap support, read access from multiple regionservers. OpenTSDB plugs along at a slower pace, but it's much more professional than i.e. Influx changing storage engines 5 time and getting worse with each. The OpenTSDB 2.2 release looks really exciting and fixes some hard high rate problems for both reads and writes: [http://opentsdb.net/docs/build/html/new.html#id1](http://opentsdb.net/docs/build/html/new.html#id1)

In the commercial space, Circonus looks pretty interesting and comes built and recommended by people I trust. It goes a lot farther than metrics storage. I wasn't able to get my management to do more than a video call to really dig in and evaluate it myself.

</comment><comment><USER3> If you're looking into time-series based monitoring/alerting, I've been delighted with [http://prometheus.io/](http://prometheus.io/).

I'm mentioning this because I previously tried to use OpenTSDB for monitoring (back when prometheus and others didn't exist), and found it too cumbersome to run (not packaged in Debian, requires an underlying HBase instance, etc.) for my taste. Many more recently created projects, such as Prometheus, come pre- packaged in a Docker container and can run on a single host — often they're even a single binary.

<comment><USER4> Prometheus is for smaller problems. You have to manage your own sharding with prometheus, so it doesn't work for handling large volumes of data unless you are willing to do complex automation for a large number of disparate replication topologies. This works fine at Soundcloud, where it came from, because the teams there like keeping their monitoring systems isolated from each other because they don't trust each other.

For problems where you require a single source of truth for high volumes of data, you can't really justify that kind of effort for the data management when distributed databases have been created to solve this problem.

Prometheus is nice and featureful, but it makes me laugh when the proponents (usually [ex-]soundcloud folks) brag about how scalable it is.

Side note: they love to say that because it's pull based, that magically makes it more scalable. This is a crock of shit. Push vs Pull doesn't get you out of capacity planning, and from this perspective they are identical in terms of throughput requirements. Pull means you need a single source to know about a ton of endpoints. Push means you need a ton of sources to know about a single endpoint. Which one is simpler to operate? They say it's more scalable because when they failed to properly do capacity planning, it hid their dropped data more effectively and their dashboards kept running, oblivious to the degredation.

</comment></comment><comment><USER5> I have been reading a lot of these comments here and some of the people who ran into issues just sound like they don't understand what they were using or building. As many have said before opentsdb is great if you understand all of your components. Hbase is somewhat of a black art. You also truly need to understand your data. You cannot just start writing data and when it fails be upset with the product. Opentsdb is no silver bullet to the metrics game but it sure as hell is better than most at a larger scale.

We are doing right now roughly 1.2m/s and will likely grow to 6-8 depending on how we chop this up. Either way you have to use any level of intelligence with this product as you do with others. I cannot stress this enough but plan out your data. Make sure you are very strict with the pattern of how things get written and the amount of tags you allow. No datapoint will initially make sense for you you may have to shift things around a bit. There is an active PR collectd that addresses metric mapping which can be very beneficial to high throughout shops.

Either way just make sure you know what you are getting into and understand your problem as well as your product you are choosing. Opentsdb could be overkill for people who just want a low amount of data per second. You will also need to plan retention policies / long term storage / hardware requirements / etc. remember you are running hbase.

</comment><comment><USER6> Not to steal limelight from OpenTSDB - it's great in many ways - if anyone is interested in experimenting with TSDBs, we've been developing HBase-based Axibase Time Series Database for 3+ years: [https://axibase.com/products/axibase-time-series- database](https://axibase.com/products/axibase-time-series-database). It supports SQL and is somewhat better packaged with built-in rule engine for alerting and visualization: example - [http://apps.axibase.com/chartlab/2ef08f32](http://apps.axibase.com/chartlab/2ef08f32). Accepts most line protocols including nmon, tcollector, scollector (works for windows, often overlooked), collectd, statsd.

Disclosure: I work for Axibase.

</comment><comment><USER7> We've been running OpenTSDB at a very large scale (~100k writes/s) for the past year and a half and have been pretty happy with it. It's not as reliable on the read side as something like ganglia and the query options aren't as powerful as InfluxDB, but it can scale better than any other option I know of.

The ability to look back into the past and get full-resolution metrics is a huge deal. With Ganglia or Graphite (which aggressively downsample old data) there's a lot of squinting to try to make out patterns past a week or so.

That said, we also use HBase as our main data store, so we have a lot of experience with operating it. I'm not sure I could recommend OpenTSDB to an organization that lacks that expertise.

<comment><USER8> If you were to create an application that relies heavily on a time series database, what would you recommend?

I'm writing an application of this sorts, and my requirements won't be too bad (about 1000-4000 metrics on a per second basis). I will also rely heavily on predefined queries (rollups to 10s, 1m, 10m, 1h, etc.).

I'm hesitant to use OpenTSDB because the community "buy-in" seems to be going down.

EDIT: I can't lose data to downsampling. I will need to store this for both troubleshooting and regulatory purposes.

<comment><USER9> I wouldn't worry too much about what the community thinks. TSDB fits the bill and works great. That being said, I've also heard wonderful things about druid.io ([http://druid.io/](http://druid.io/)), however I've yet to personally try it. We're going to start testing and throwing data at druid early next year though.

</comment></comment></comment><comment><USER7> We've been running OpenTSDB at a very large scale (~100k writes/s) for the past year and a half and have been pretty happy with it. It's not as reliable on the read side as something like ganglia and the query options aren't as powerful as InfluxDB, but it can scale better than any other option I know of.

The ability to look back into the past and get full-resolution metrics is a huge deal. With Ganglia or Graphite (which aggressively downsample old data) there's a lot of squinting to try to make out patterns past a week or so.

That said, we also use HBase as our main data store, so we have a lot of experience with operating it. I'm not sure I could recommend OpenTSDB to an organization that lacks that expertise.

</comment><comment><USER10> I have been looking for a scalable TS solution similar to ElasticSearch - single node to 1000's all PnP.

</comment><comment> chaotic-good OpenTSDB is really nice but it has some drawbacks:

1\. Limited timestamp precision (because of storage schema).

2\. Dependency on HBase.

</comment><comment><USER11> It is alot of work to keep up. I would use KairosDB instead. [https://kairosdb.github.io/](https://kairosdb.github.io/).

<comment><USER9> What sort of work are you referring to when you say it's a lot to keep up?

We've been using OpenTSDB here in an extremely high traffic setup for about a year now, with absolutely no issues at all. It took a few hours at most to setup and figure out scaling.

<comment><USER4> I love OpenTSDB, but I think it's highly unusual for people to have "absulutely no issues at all". I ran OpenTSDB at the hundreds of thousands to low millions of ops per second range for several years. OpenTSDB has historically crapped itself when you have writes hit it for rows that it already ran its all-columns-for-an-hour-into-a-single-column compaction on. Now it just drops data on reads.

If you have a large team of engineers writing data into it, they will sometimes abuse the schema by overloading single metrics with many tags. Every permutation of tag*value creates a new row per hour of data. This creates extremely hot shards when engineers inevitably do something like store a client IP address into a tag. When this happens, you may have to write some web-UI scraping code to figure out which regions are getting the most traffic (assuming you have "extremely high traffic setup" numbers of region servers), or script up something like misra-gries on a tcpdump of its inbound metrics to see where the hot shit is so you can get somebody's deploy reverted. I know of some companies that have forked OpenTSDB and prefixed each row with a hash such that it spreads overloaded metrics around the cluster much more evenly. KairosDB solves this by not using a lexicographically sharded database (Cassandra).

When run properly, it runs great. But that takes some really painful learning experiences to learn how to do, generally.

<comment><USER2> OpenTSDB 2.2 has this hot region problem fixed with salted UIDs.

<comment><USER4> Badass! This would have saved me about a week of my life if it had come a few years ago!

</comment></comment></comment></comment></comment><comment><USER12> So, we need a new database engine instead of mere using tables with partitioning in PostgreSQL with a timestamp as a primary key?

And it is Java - waste two times more resources than the data you have ™

<comment><USER6> Not sure if your Java comment is warranted, a lot of Apache projects are either written in Java or run on JVM. Yes, HBase's memstore can be optimized, in particular for small key values, but that doesn't negate a need for time- series databases with proven scaling. HDFS offers that. How you were planning to design your tables in PostreSQL if you have 1m+ unique series inserting at 100K+/sec. Assuming you use timestamp as a PK does it translate into 1m+ tables?

<comment><USER12> We have already seen how Cassandra clone in C++ perform.

I think that adding a new indexing strategy to a decent engine could be a good idea.

Informix did this.

<comment><USER2> Mapr has an HBase compatible stack in C++, I would love to see TSDB numbers on that. TSDB is pretty efficient itself and since metrics collection is such a batchy operation JVM isn't really that much of a problem. You can run some dedicated TSDs for front end/UIs to ameliorate JVM pain there too.</comment></comment></comment></comment>


State of the Octoverse 2013 - <AUTHOR> http://octoverse.github.com/ <comment><USER2> One thing on this that surprises me is that the Rust repo has the second highest number of issues closed out of any repo on github, after homebrew.

<comment><USER3> I'm not sure if it's much of a compliment, but it shouldn't be a surprise to anyone that we have a lot of bugs. :) I guess the good news is that we're apparently working damn hard to squash them!

<comment><USER2> closing issues is good!! you guys work really hard and rust is awesome!

its cool to see a language being iterated on so publicly :)

</comment></comment></comment><comment><USER4> These graphics/charts are beautiful. Any more details on how they were made?

<comment><USER5> The data seems to be coming from these URLs:

[http://octoverse.github.com/data/totals.csv](http://octoverse.github.com/data/totals.csv)

[http://octoverse.github.com/data/shipped- drinkups.csv](http://octoverse.github.com/data/shipped-drinkups.csv)

[http://octoverse.github.com/data/requested- sponsorships.csv](http://octoverse.github.com/data/requested-sponsorships.csv)

[http://octoverse.github.com/data/daily- activity.csv](http://octoverse.github.com/data/daily-activity.csv)

[http://octoverse.github.com/data/sample- events.csv](http://octoverse.github.com/data/sample-events.csv)

[http://octoverse.github.com/data/world-110m.json](http://octoverse.github.com/data/world-110m.json)

[http://octoverse.github.com/data/world- wo-a-110m.json](http://octoverse.github.com/data/world-wo-a-110m.json)

and displayed with d3.js (see [http://octoverse.github.com/javascripts/all.js](http://octoverse.github.com/javascripts/all.js))

</comment></comment><comment><USER6> A lot of people(airbnb comes to mind) doing these now, cool to see one from GitHub.

I don't know if there is a bug with the globe but that seemed pretty weak to me-- not enough data and random points get highlighted. Anyone else find it a little lacking-- kind of like a silly "let's include a d3 globe just cause we can"?

</comment><comment><USER7> Kudos to the coders who built this interactive Infographic. Very impressive.

</comment><comment><USER8> Wow, github is all mostly grown up now. Hundred staff or so.

Three 🍻 (:beers:) !

<comment><USER9> We actually have more like 238 Hubbers. You can see us at [https://github.com/humans.txt](https://github.com/humans.txt) or [https://github.com/about/team](https://github.com/about/team).

<comment><USER10> It seems like only the early employees get cool nickname I thought github has an eglatarian culture?

<comment><USER11> Pretty much only the early employees remember where that humans.txt is stashed.

</comment></comment></comment></comment><comment><USER12> It's so sad to see meet ups and drink-ups from every state surrounding Alabama, but not actually in Alabama. I take great pride from being in this state my entire life, and I'd like to start something here.

<comment><USER11> I wouldn't be surprised if a few GitHubbers dropped by Huntsville sometime this summer. Watch the blog.

<comment><USER12> That would be awesome. I'm originally from Huntsville but in Birmingham right now - I might try to organize some sort of unofficial deal here. There's a surprising amount of hackers and makers here from what I've seen around the internet and talks with my coworkers (just moved to bham).

</comment></comment></comment><comment> brown9-2 What timezone does that data in the daily and hourly graphs reflect?

<comment><USER13> If it's like most other parts of Github, it's based on the timezone recorded for each particular commit. That is, if you're in PST while I'm in CST (or at least our respective development environments think that) and we make a commit simultaneously, your commit activity will "occur" two hours before mine.

Github is a global company, so it would be surprising to see such a perfect "working day" profile on that graph if local timezone were not taken into account.

<comment> brown9-2 Agreed that would be the ideal way to present the data, but was curious if that was really the case since the pushes start climbing at 7am and fall off at 3pm.

<comment><USER12> Almost mimics my usual day to a t.

</comment></comment></comment></comment><comment><USER14> I was stoked to see some events I love up there on the Community page.

Whooo CodeDay! [http://codeday.org/](http://codeday.org/)

</comment><comment><USER15> I wonder how they make the globe

<comment><USER16> Looks like they're using a custom D3 build.</comment></comment>


HN Plays 2048 - <AUTHOR> https://hnplays2048.herokuapp.com/ <comment><USER2> Took a look at your code and noticed you're using Socket.io. Don't use Socket.io for anything over double digit concurrent users. It's well known to be horrible at scaling. If you want something that's _better_ at scaling I'd suggest SockJS[1].

1 - [https://github.com/sockjs/sockjs-node](https://github.com/sockjs/sockjs- node)

<comment><USER3> The "over double digit" claim is simply not true. I'm running three multiplayer games for about two years now, and it starts to have problems once if goes over 3500 concurrent connections. It could be that I just hit the right combination of node+socketio versions, though, as I had problems with newer ones. My setup is:

node.js 0.6 socket.io 0.9.6

This version of socket.io has a nasty bug in jsonp protocol handling which I patched manually by merging some change from a newer version, but it does work fine.

To make it scale, I run multiple node processes. In the last 300+ days each of those has between 1000 and 2000 concurrent connections all the time and it works fine. Except that there is some memory leak (I'm not sure if it's related to socket.io or some other lib), so I restart each server once a week (it's done automatically each Sunday at 2am).

I had my eye on SockJS since 2012, and it looks like newer versions are really good, but I'd need upgrade to newer nodejs and this is simply not possible for the existing projects as many used modules are not available.

However, if you're starting a new project, it's worth testing and see which performs better.

<comment><USER4> We also do had a memory leak because of socket.io 0.9.6

take a look at this discussion [https://github.com/LearnBoost/socket.io/issues/1303#issuecom...](https://github.com/LearnBoost/socket.io/issues/1303#issuecomment-33107520)

<comment><USER3> Interesting, but I'm not using Redis nor MemoryStore. I gave each machine behind HAProxy a different hostname (mapped to the same IP address), and I route the clients in roundrobin fashion to each of those before they open the page with socket.io javascript. It works like this:

\- client opens a page on HAProxy load-balancer picked server

\- the actual node server that receives the request, redirects the browser to its custom hostname using the same URI

\- client opens the same page on the particular server and socket.io connects to that subdomain

This ensures that all future requests (if socket.io connection is broken) will go to the same server without Redis, MemoryStore, cookies or whatever.

Drawbacks:

\- one additional HTTP redirect when page that contains socket.io is loaded (luckly, in games there aren't many of those)

\- if you want to retire some sub-domain hostname, you have to be careful to allow existing clients to re-connect somewhere else. Not really a problem for my setup, but YMMV.

<comment><USER5> How does this work for non-socket transports? You have to be saving the broadcasts in case someone is polling, right?

<comment><USER3> I'm not sure what you mean by "saving the broadcasts". Can you give an example?

Some 11% of clients are using XHR or JSONP protocols and it it Just Works(tm), I did not add anything special.

<comment><USER5> You said you don't use Redis/MemoryStore, but when you broadcast something it has to be saved somewhere until all of the polling sessions get it. Where is it being saved?

</comment></comment></comment></comment></comment></comment></comment><comment><USER6> Hey guys, it's the creator here.

I never thought this little project would get this big!

If someone wants to help me scale this, or add things like chat, please do! Just send a PR on Github!

[https://github.com/grant/hnplays2048](https://github.com/grant/hnplays2048)

<comment><USER7> I literally was going to do this this coming weekend, same name even!

I was going to take a much different approach however - I was going to use rabbitmq speaking STOMP over a websocket [0] with two queues, one for client moves, which the server would consume and write to the moves queue, which each client would consume. This would allow the server to do more fancy rate limiting / throttling as not to just lead to a message storm. This, along with storing the game state in a db, allows for scaling out app servers.

0 - [https://www.rabbitmq.com/blog/2012/05/14/introducing- rabbitm...](https://www.rabbitmq.com/blog/2012/05/14/introducing-rabbitmq-web- stomp/)

</comment></comment><comment><USER8> Kind of fun, but I agree with some of the other comments that it would be interesting to see what would happen if the app made a move every 15-20 seconds based on the vote tally in that time window.

<comment><USER9> Right. It needs a Democracy mode. maybe even a Democracy/Anarchy slider controlled by Q and E.

<comment><USER10> Ask and you shall receive [http://hnplays2048-democracy.herokuapp.com/](http://hnplays2048-democracy.herokuapp.com/)

Edit: Now integrated into the OP's app

<comment><USER11> Users should only be able to vote once (maybe be allowed to change it, but right now someone can overrule the consensus by hitting an arrow key as many times as they can)

Nice work though!

<comment><USER12> Isn't that a metaphor for democracy in America today?

</comment></comment></comment></comment></comment><comment><USER13> This game is no more playable than it was when it was posted hours ago. And here's why:

setInterval(function() { window.manager.inputManager.emit("move", Math.floor(Math.random() * 3) + 1); }, 1000);

Some rate limiting has been put in place, but it's not good enough. If there are 50 users online at once, they all shouldn't be able to spam a command every second.

A better algorithm would be:

seconds_between_commands = 60 - (60 / number_of_players);

With a clock letting you know when you can make your next move.

Otherwise, it's just way too easy to spam.

<comment><USER6> Good idea. Working on it.

</comment></comment><comment><USER14> It's currently unplayable. Instead imagine if it would make one move every half a minute. During the time between moves anyone could vote on the next move. Then the winning move would be played. It would be a slow game, but would be the aggregate HN wisdom.

<comment><USER15> This is awesome. It's anarchic and chaotic and amazing.

I can't wait until it falls off the frontpage and drops to 5 users.

EDIT: We killed it. Nooo.

<comment><USER6> Should be online now.

</comment></comment></comment><comment><USER10> I added democracy mode...

The pull request is here: [https://github.com/grant/hnplays2048/pull/10](https://github.com/grant/hnplays2048/pull/10)

You can play it here: [http://hnplays2048-democracy.herokuapp.com/](http://hnplays2048-democracy.herokuapp.com/)

<comment><USER16> I like this one a bit better because it shows vote totals and has a visible countdown:

[http://voting-2048.herokuapp.com/](http://voting-2048.herokuapp.com/)

<comment><USER16> Pull Request if anyone wants to see the code. Sorry this is in 2 places.

[https://github.com/grant/hnplays2048/pull/13](https://github.com/grant/hnplays2048/pull/13)

</comment></comment></comment><comment><USER17> Is this HN's version of twitch plays Pokemon? [http://www.twitch.tv/twitchplayspokemon](http://www.twitch.tv/twitchplayspokemon)

<comment><USER18> Yes. Explicitly.

[https://news.ycombinator.com/item?id=7431436](https://news.ycombinator.com/item?id=7431436)

</comment></comment><comment><USER19> I've made a version of 2048 on Hexagonal Board - check it out [https://play.google.com/store/apps/details?id=com.spiralcode...](https://play.google.com/store/apps/details?id=com.spiralcodestudio.hexled)

</comment><comment><USER20> This makes a perfect illustration why startups are shit. Instead of working on something useful, people either produce crappy javascript games, or play them. Now massively downvote this comment, write 100 replies explaining why I'm wrong and how retarded I am for trying to say something like this, then go read something by Paul Graham and play more clones of 1024. And then write a long essay why your startup failed.

</comment><comment><USER21> Damn, this version seems so unplayable-- so much chaos. When I play on my own, I already do so many random moves until I reach 512. After that every move that I make is evaluated. I have no problems reaching 2048 (or 29,000 points) within 10-15 minutes.

Here, I just get frustrated with the slowness of the moves (not to mention the strategy of the "democratic group" is way off)

</comment><comment><USER22> Here is my app for Android: [https://play.google.com/store/apps/details?id=com.contraryki...](https://play.google.com/store/apps/details?id=com.contrarykid.twos)

<comment><USER23> Nice. I shall try this and never be productive for the rest of my life with all these 2048 forks.

</comment></comment><comment><USER24> Utter chaos going on in the game over there. But it's a fun experiment.

</comment><comment><USER25> This is probably a bit much, but I'd love to see someone whip up a multiplayer 2048 using something like Firebase. It would probably start many an argument.

</comment><comment><USER26> It's pretty interesting how the strategy derived by averaging over multiple intelligent users can be that sub-optimal.

</comment><comment><USER27> Can someone index all of these versions :)

</comment><comment><USER28> This seems to show what I thought when I originally saw the game, that random spamming would get you pretty far.

</comment><comment><USER29> It would be nice to know your own user #.

<comment><USER6> Good idea! I'll make an issue for this on Github.

<comment><USER6> Your own user inputs are now bolded

Commit: [https://github.com/grant/hnplays2048/commit/308f68341b2c54bf...](https://github.com/grant/hnplays2048/commit/308f68341b2c54bf672b40c0c6de300bbd72af10)

</comment></comment></comment><comment><USER30> This needs a delay. That way you can follow the chaos instead of just staring at a moving screen.

</comment><comment><USER31> [http://xkcd.com/1344/](http://xkcd.com/1344/)

</comment><comment><USER32> It is a good demonstration that in cases like this user democracy is a loosing strategy.

</comment><comment><USER6> Man... scalability sucks.

</comment><comment><USER33> A-a-and it's down.

</comment><comment><USER34> Another case of "HN crashes the heroku app"

<comment><USER35> LOL

</comment></comment><comment><USER36> We really need a democracy mode for this

<comment><USER37> it has been added and is awesome

</comment></comment><comment><USER38> I really don't like to hate on other people's work but seriously more 2048 forks? And now ones that aren't even remotely playable?

<comment><USER39> Make 2048 forks, not war.

</comment></comment><comment><USER40> Start9

<comment><USER41> Anarchy lasted minutes before the democracy babies came running in.

</comment></comment><comment><USER39> seems like it falls victim to popularity, and crashes often.

</comment><comment><USER42> holy hell this makes me hate you all! =P

</comment><comment><USER43> the chaos.

</comment><comment><USER35> Crashed!!

</comment><comment><USER44> you guys really suck at this game.

<comment><USER45> I'd love to give people the benefit of the doubt and attribute it to spoilers who intentionally move it against the flow, but I have my doubts.

</comment></comment><comment><USER46> A joKE?</comment>


Amazon sells out of the NES Classic Edition in less than a minute - <AUTHOR> https://techcrunch.com/2016/11/11/nintendowned-amazon-sells-out-of-nes-classic-editions-in-null-seconds/ <comment><USER2> _Clearly thousands, if not hundreds of thousands, of gamers were sitting on the product page hammering the F5 key and some random selection thereof got their wish._

I highly doubt that. My guess is that third party resellers used bots to purchase them all.

Why wouldn't tc come to the same conclusion?

Edit. yep here's one on eBay for $500+:

[http://m.ebay.com/itm/New-Nintendo-NES-Classic-Edition- Conso...](http://m.ebay.com/itm/New-Nintendo-NES-Classic-Edition- Console-30-classic-Games-included-In- Hand-/282251775042?hash=item41b7844c42%3Ag%3AdQgAAOSwB09YJQNg&_trkparms=pageci%253A0eaa36dd-a868-11e6-b61e-74dbd18070b6%257Cparentrq%253A55c26f941580a5eb36147d47fffca634%257Ciid%253A1)

<comment><USER3> Nintendo has had a history of unexplainable supply shortages for in-demand items. (case in point: Amiibo)

<comment><USER4> Ha .. not unexplained. I am part of a few "deals" websites. People inexplicably want to collect all of them! They have predictions on what Amibos will sell out, so people can buy 'em sooner rather than later. Lots of crazy stuff. I thought it was to make a profit but it seems there are genuine collectors out there.

<comment><USER5> Digital age Beanie Babies?

[http://www.slate.com/articles/health_and_science/science/201...](http://www.slate.com/articles/health_and_science/science/2015/02/beanie_babies_bubble_economics_and_psychology_of_a_plush_toy_investment.html)

<comment><USER6> I've been calling them that for years.

</comment></comment></comment></comment></comment><comment><USER7> I grok capitalism and even like it. But there are times where it is difficult to like it. In this case, people rushed to buy this product for the sole purpose of reselling it for 8x. What's wrong with our society that some people can be so morally bankrupt and bereft of good sense.

In the end, I think these scalpers won't sell for 8x because anintendo will just pump out more product. Still, it is sad to see this happen.

<comment><USER8> _What 's wrong with our society that some people can be so morally bankrupt and bereft of good sense._

This type of behavior is literally all around us. I recently listened to a podcast about this exact phenomenon. It featured a couple that had a special rug that drove cats crazy. They sold it on amazon for ~$35. A bunch of people bought them up and sold them on ebay for a lot more, using the drop-ship method (the reseller ordered it using their amazon account with the buyers shipping address).

When people realized they were being ripped off, they returned it to the original seller, who had to handle the claims due to requirements by amazon. They lost 10's of thousands of $$. The creator called some of the people doing this and they laughed him off, telling him they were doing nothing wrong.

It was on planet money's podcast, I think. I can try and find it if you're curious.

<comment><USER9> Episode 724: Cat Scam[1]

1: [http://www.npr.org/sections/money/2016/09/14/493810206/episo...](http://www.npr.org/sections/money/2016/09/14/493810206/episode-724-cat- scam)

<comment><USER10> As a side note, that episode left me wondering why the original seller didn't open their own eBay store, listing the product at their desired price. I would have thought it would have effectively undercut the resellers and gain a large portion of the sales on eBay.

Another note, Planet Money is pretty much my favourite "always on"* podcast. An podcast about economics might sound dull to some, but what a lot (maybe not on HN) people don't realise is "economics" is a really a study of human behaviour at the macro level, and a large part of human behaviour at the micro level.

* serial was hugely addictive, but it only has short seasons, and each episode had what seemed like a huge wait between them.

<comment><USER11> The original seller did [0]:

      This summer, Ruckel tried a new approach: He put his own product on eBay and titled it "All other eBay sellers are fake." A few weeks later, he stumbled upon an eBay listing with a familiar title. "All other eBay sellers are fake," it said. It wasn't his, of course.

[0] [https://www.entrepreneur.com/article/278622](https://www.entrepreneur.com/article/278622)

</comment></comment></comment></comment></comment><comment><USER12> Why doesn't Nintendo just raise their prices to where supply equals demand? They're leaving So much money on the table for scalpers.

Or why not first release an expensive limited edition while they scale up production?

<comment><USER13> Because now they get to be on the news with a bunch of stories talking about how hot their new product is.

<comment><USER14> Exactly. I wouldn't have even known they released an official NES-raspberry- pi-esque product otherwise.

</comment></comment></comment><comment><USER15> I wonder if these things are timed for release once a target audience hits a certain age? What is that age?

It was about 8 years between 1st gen consoles (Atari, Intellivision, Colecovision) and 2nd gen (Nintendo). The retro-rerelease of 1st gen was about 8 years ago. I am 45 and am nostalgic about 1st gen. I was in high school for 2nd gen; no nostalgia, uninterested.

So do these retro-rerelease target those in their late 30's. Mid life crisis yearning for nostalgia?

<comment><USER16> What was the "Atari, Intellivision, Colecovision" retro-release? Seems like a newish phenomenon due to falling cost of production.

Objectively, (if you put a complete novice kid in front of a console), NES and SNES's good/great games are the best.

<comment><USER17> madengr is right, the Atari ones have been available since 2004. They've put out a new version of it every other year or so. This year is their 7th version of the Atari Flashback. [https://www.amazon.com/Atari-Flashback-7-Classic- Game-Consol...](https://www.amazon.com/Atari-Flashback-7-Classic-Game- Console/dp/B01KV6E6Z2)

There's ones for Intellivision ([https://www.amazon.com/IntelliVision-AtGames- Flashback-Class...](https://www.amazon.com/IntelliVision-AtGames-Flashback- Classic-Game-Console/dp/B00K2BOG66) ) and Colecovision ( [https://www.amazon.com/ColecoVision-AtGames-Flashback- Classi...](https://www.amazon.com/ColecoVision-AtGames-Flashback-Classic-Game- Console/dp/B00NM9R6GW) ) too, but those have only been available for the last few years.

<comment><USER18> And there's been a Sega Genesis Classic Game Console (with 80 games) since 2012 or so.

[https://amzn.com/B01KV6E72O](https://amzn.com/B01KV6E72O)

</comment></comment></comment></comment><comment><USER12> It seems silly to me to allocate a product by the vageries of refresh rates and server responsiveness.

It seems like Amazon could come up with many other ideas for allocating a limited product. There's no rule that says it has to be based on the millisecond ordered.

For example how about a game of chance (or skill?) to let people compete for the product? It would feel a lot more fulfilling than an error page. And it would give them good brand interaction.

<comment><USER19> Eh, or what about loyalty to amazon? If they had honestly messaged me and said that because of the age of my account and amount I had spent that I would get to be part of the first group in line to purchase, I might have even bought one just for that reason. Not that they needed more people buying them, but my loyalty to them would probably only go up.

<comment><USER20> On the flip side, stuff like this just sours the whole thing. Why have a sign up page to be alerted when something's available if you know it's going to be sold out immediately?

</comment></comment></comment><comment><USER21> It'd be one thing if the product just came out, had a lot of media fanfare and sold out due to low volume. I mean that's reality right. But the fact that it appeared in weekly ads for stores all over the country. It's really expectation that hurts the most.

That's just causing hassle, distrust. Retail employees probably don't lke to get 50 extra calls a day for a product that will be in stock for 14 seconds. If I were a regional mgr I'd put VERY heavy pressure on corporate for say Target to NOT show ads for this product until reasonable levels of stock are guaranteed. Targets around the country got about 11 units. The one I went to only had 1 spare controller. Keep in mind that a good portion of the NES games are co-op.

There are 1800 target stores in the U.S. If they all got 11 units that means there were only 19,000 units for that store. I heard gamestops got about 5. Walmarts got about 6 units each.

So 6 units to walmarts 5229 stores is about 31375 unit. Gamestops 4,434 stores at 5 units each get 21700

Who knows what amazon stocked at. Would it be reasonable to say amazon got 10000 units? I mean they sold out in a minute. Maybe it was less than that.

So those totals add up to 82,075 units. Let's round up, not forgetting the Best Buys, Microcenters, mom-pop shops and The 800 Toys R Us stores in the U.S. and say the United States got maybe 112,000 units total for the release.

</comment><comment><USER22> Nintendo needs to come out with an official retro wifi appliance that allows one to buy classic games from an App Store and play 2 player games over the network.

</comment><comment><USER23> The Amazon reviews got brigaded with 1 star reviews. They should work on preventing this.

<comment><USER24> Why? Nintendo decided to once again screw over their fans with their supply games. People are getting back at them for it.

<comment><USER25> Why? Because bitching at Nintendo is not a review of the product. Obviously.

</comment></comment></comment><comment> gm-conspiracy Only half of my Nintendo holiday arbitrage attempts have been successful.

There will be limited availability for a short time, then a flood of product.

<comment><USER26> When I was younger, half the fun was trying to obtain the limited availability consoles!! Now it's no longer fun, just refresh a page and hope resellers don't buy up inventory before you can grab one.

I'm still impressed that my mom somehow managed to get me an n64 for that first Christmas they were available! I was in disbelief since I was certain they were impossible to get. 13yo me had all the local toy store #s memorized and I'd call every day asking if they received any shipments. No dice.

Shadows of the Empire on Christmas morning was so awesome! Tripping up those AT-ATs that morning was one of the more memorable moments in my gaming history.

A few months prior, for my best friend's September birthday, his mom took us to Toysrus and let him pick either the just released n64 +1 game OR the on- sale SegaCD and a bunch of games. He chose... poorly.

</comment></comment><comment><USER27> "Nintendowned: Amazon sells out of the NES Classic Edition in (null) seconds"

This is the headline I am seeing at the moment. Seems like the guy who was supposed to update the time forgot to do so.

</comment><comment><USER28> Honestly, I was going to buy one. But the itch will probably pass by the time they're back in stock. Since I'm filling that itch with emulators now.

At an impulse buy price point, I wonder how many unrecoverable lost sales are caused by lack of supply.

<comment><USER29> Agreed. All the sell-out did was frustrate me a bit then set me on a mission to create the ultimate all-in-one raspberry pi image.

<comment><USER30> Put lakka on an SD card. Put your roms on one of those super-cheap 128gb USB sticks that exist these days. Use PS3 controllers. Done.

[http://www.lakka.tv](http://www.lakka.tv)

(I know I've posted lakka twice in this thread, but I'm not affiliated, just a happy user)

</comment></comment></comment><comment><USER31> The little machine is nice, but I wish they simply had some kind of an app store for old game ROMs. I would pay the price of a mobile game for old Mario Bros etc. Instead I have to download them from shady sources.

<comment><USER32> Umm, ever heard of virtual console on the Wii and Wii U?

<comment><USER31> I don't need a Wii, I just want to play the old games (alongside with old Atari and Sega).

</comment></comment></comment><comment><USER33> This kind of stuff is par for the course with Nintendo hardware from what I can tell. Is it deliberate? If so, does perceived scarcity drive more sales, or are they just sick of warehousing unsold products?

<comment><USER34> Well, they did just get free advertising in the form of this TechCrunch article. Wouldn't be surprised if other news outlets pick on up on the story as well, with the spin of "the hot new Christmas toy".

From that perspective, having short supply on release day seems like a decent plan. Once they get the publicity, I bet the supply increases to match demand within the following month.

</comment></comment><comment><USER35> Thought of this when I was browsing AliExpress for Singles Day, today, and found this:

[https://www.aliexpress.com/item/Video-Game-Projector-PGS- Con...](https://www.aliexpress.com/item/Video-Game-Projector-PGS-Console- built-in-8bit-NES-Childhood-Games-with-2-Joystick-Support- Dual/32526098498.html)

Available cheap for another 8 hours, maybe something to tide them over?

<comment><USER36> The fact that these projectors have such low resolution, playing retro games is about all they are good for.

</comment></comment><comment><USER37> I had the chance to buy one yesterday morning and I didn't take it up. That was my first hearing about it and I gotta say, beyond resell value I don't see the appeal of this thing.

You can make a smaller NES with a Pi Zero and rented time on a 3D printer. I don't think people would have a problem trading use of cartridges for a much larger, cross platform selection.

Is this a business opportunity?

<comment><USER38> Found the guy that has never tried emulation on a Pi.

<comment><USER39> Can you elaborate? Ive never used an emulator. I'm thinking NES games have a very low need for cpu / mem resources. Do they not run as good as the original?

<comment><USER40> I've tried an emulation box with RetroPie and the controller drivers are hard to find (at least for xbox 360 wired controller), the controls are difficult to set up (requiring manual edits to config files, which you need to plug a keyboard into your rpi to do), the controls are glitchy after you set them up, and the interface is not intuitive at all. If someone has a better idea for pi emulation I would really like to try it.

<comment><USER30> Use Lakka, not RetroPie. Use a PS3 controller—360 would work, but its dpad is _terrible_ , and both work with no extra effort. PS3 even works over bluetooth with little to no fiddling. Only trick is you have to find the "right" roms (those blessed by various projects that record hashes of accurate rom dumps) or Lakka/Retroarch's auto-rom-scanning won't work, though you can still select roms manually. Small price to pay for the level of "just works" that Lakka provides.

[EDIT] links:

[http://www.lakka.tv](http://www.lakka.tv)

Which romsets to use for various systems:

[http://libretro.com/forums/showthread.php?t=6661](http://libretro.com/forums/showthread.php?t=6661)

</comment></comment></comment></comment></comment><comment><USER41> All of these outages could be prevented by opening sales randomly in time windows and in small waves. Or with preordering. The same applies to sales with price reductions, etc. All these companies shoot themselves in the foot with stunts like that. Why not make it more expensive if there is such a demand, anyway?

<comment><USER24> > Why not make it more expensive if there is such a demand

Is demand really high enough to support a higher price? Nintendo is infamous for putting out a short supply.

I don't understand why Amazon can't just take preorders for the next batch.

</comment></comment><comment><USER42> What's the (null) for in the headline?

Nintendowned: Amazon sells out of the NES Classic Edition in (null) seconds

<comment><USER40> If I had to guess it's probably a non-programmer trying to be clever, even though (null) doesn't make any sense in the context.

</comment></comment><comment><USER43> They may have all 'sold' but there are 4,000+ available on eBay at the moment.

</comment><comment><USER44> idk what happened but at 1400PST on the money i loaded it... "add to cart" and "buy now" buttons were there but their function was inoperable. That page was broken for hours after that. And now it just says not available. ugh

</comment><comment><USER45> i continuously got an empty shopping cart everytime i tried to add it.

i am pretty sure the site was hit so hard they just 404'd the URL so it wouldn't load anything. for a while the item page was blank while amazon.com continued to load.

</comment><comment><USER46> It is such an overrated product, I have one, tried it and will send it back to amazon asap. It is Bad in so many levels, the short Controller cable is only one.

<comment><USER47> The short controller would suck, but it's kind of a requirements for compatibility with the wiimote. It 'speaks' i2c and at the data rates they require it's unlikely they could go much longer.

</comment></comment><comment><USER48> Amazon should do popular items like this using a lottery system to hurt the advantage bots, scripts, and people with lower latency have.

\- You can enter the item lottery for a longer period (e.g. 60 minutes).

\- Lottery winners are picked at random, not based on entry time.

\- Max one entry per household (remove entries with duplicate mailing addresses, duplicate credit cards, and duplicate email addresses).

\- Once someone wins they have a window to purchase (e.g. 3 hours). If they fail to purchase then the lottery picks a new winner.

Now obviously cheats will still exist, but at least they're all on a fairer playing field with normal purchasers.

<comment><USER16> MBA Interview pro-tip: Amazon should make NES a Prime-only item.

<comment><USER49> [https://www.amazon.com/treasuretruck](https://www.amazon.com/treasuretruck) had it today.

<comment><USER50> Also sold out in minutes.

</comment></comment></comment></comment><comment><USER51> Sounds like Nintendo, along with a bunch of other companies, need to take a page out of USSR's book. The way it worked there is that you put your name on the list to buy, say, a car. And when the car is actually manufactured, you get to buy it. Big product launches like this could really benefit from a system like that.

I know some places already do this: x.ai comes to mind. They even had a thing where you could move yourself up in the queue by getting others to sign up.

<comment><USER52> The way it worked in the USSR was actually more like: you put your name on the list to buy a car. The local party boss' cousin wants a car, too, and he doesn't have to wait on the list, he gets the car that's being manufactured. And the factory director's brother wants a car, too. And his nephew. And the guy he is trading cars to for steel to make more cars. And that guy's cousin wants a car, too. All these people get to skip ahead of you on the list, because they have better connections than you do. So you wait ten years or so for an ordinary car.

<comment><USER53> It's not really related, but it reminds me of this joke about buying cars in the USSR as told by Ronald Reagan: [https://www.youtube.com/watch?v=CLW7r4o2_Ow](https://www.youtube.com/watch?v=CLW7r4o2_Ow)

</comment></comment></comment><comment><USER54> Funny thing, they are in stock in the local electronics store in my small hometown in Slovenia :)

<comment><USER55> Where at? I'm in Croatia and I really wanted to buy one!

</comment></comment><comment><USER56> Anybody know if Sega Genesis is also coming out in similar fashion?

<comment><USER57> I doubt it. I walked past a whole shelf of Sega Genesis emulation boxes at Target. That and the Atari Flashback 7 seem to be heavily stocked.

</comment></comment><comment><USER58> Days spent in my childhood...</comment>


First Swiss Unicorn. Dubai Invests in FinTech Centralway Numbrs - <AUTHOR> https://techcrunch.com/2017/01/10/the-investment-corporation-of-dubai-centralway-numbrs/?_ <comment><USER2> Some serious funding round here: the investment capital of the banking app provider currently amounts to $ 125 million.</comment>


Patterns of Regional Cerebral Blood Flow as a Function of Obesity in Adults - <AUTHOR> https://www.iospress.nl/ios_news/body-weight-has-surprising-alarming-impact-on-brain-function/ <comment><USER2> Worth noting that the first author is CEO of this clinic [0]: [https://www.amenclinics.com](https://www.amenclinics.com)

> At Amen Clinics, it all starts with you. We look at your biological, > psychological, social and spiritual influences to get a complete picture of > who you are as a person. With life coaching, nutritional guidance and > personalized therapy, we provide the tools you need to feel confident, > complete and hopeful for the future. We are dedicated to helping you find > the answer to you.

0: [https://www.j-alz.com/manuscript- disclosures/20-0655r2](https://www.j-alz.com/manuscript-disclosures/20-0655r2)

</comment><comment><USER3> From reading the proof, it seems the authors are mainly focused on "linking" or showing correlation, not causation.

Part of me wonders about the directionality of causation here (If we assumed one existed). One could argue the hippocampus, which from my recollection is involved in inhibiting impulsive behavior, has a clear path to being a causative agent for obesity. Distinguishing between the two narratives of "Being overweight inhibits brain function" versus "Differences in part of brain controlling impulses leads to weight differences" is important to resolving it, as it is easier to imagine treatment regimens to combat weight more than brain blood flow.

It is also completely possible these two variables do not affect each other, but are correlated. That's useful still, because it means we may be able to use body weight increases as an inferred marker for the brain changes.

It would be incredibly interesting if the story of Alzheimer's transformed more into "Same factor may be causing both America's obesity increases as well as Alzheimer's cases"

Edit: Updated this a few times while reading the original paper

<comment><USER4> Or maybe fructose intake and absorption correlates to both obesity and cognitive function.

<comment><USER3> I fell into the same over-reaching trap I was critiquing, which is a bit funny, but I agree they could be caused by the same thing and correlated because of that as well.

</comment></comment></comment><comment><USER5> I'm suspecious of this because the author is Dr Daniel Amen. Who makes a lot of money from brain scans that are considered suspect by many medical professionals. I would be inclined to withhold judgement until some more objective group corroborates this.

<comment><USER6> Anybody with infomercials on PBS should be regarded with suspicion.

</comment></comment><comment><USER7> Worth noting that the vast majority of the participants in this study had existing mental disorders, 57% "generalized anxiety", 51% ADHD, 17% Major Depression, 7.4% Bipolar Disorder, and so on.

The authors claim (but don't show their work) that adjusting for these factors did not change the statistical significance of the relationship, but it does still mean this isn't exactly a representative sample of the population.

Very interesting that underweight people generally have more blood flow than "normal" weight people, though if you dive into the supplementary data that doesn't hold for every region of the brain studied (and the general trend seems to hold in all regions studied).

</comment><comment><USER8> Presumably this has more to do with body composition/diet than weight, right? I.e. a muscular person with a healthy diet and normal amount of body fat but with high BMI is not at higher risk. (I'm not debating the merits of using BMI, I realize it is a useful proxy).

<comment><USER9> Correct, but this is so rare that can be ignored.

<comment><USER10> Huh what? Any high muscle athletic person would hit this.

<comment><USER11> What percentage of males in the US with a BMI over 30 (obese) have a body fat percentage less than 25? My guess is less than 3%, but I don't have data to back it up. When studying populations you can ignore these outliers. It's well known that BMI works well for populations but can fail when looking at individual health.

<comment><USER12> Checking in - MBI over 30. Body Fat Percentage less than 10. It's not rare in my circles

<comment><USER13> The point is that individuals with high BMI and low body fat are rare in the general population, and can be ignored as statistical noise in most broad scientific studies. Your circles would only be relevant for studies specifically targeting body builders.

<comment><USER10> They're not though, what? I want to see you back up this claim with evidence before passing it off as fact.

Edit: It is fairly easy to be < 25% body fat with normal musculature that accompanies normal weight lifting and cardio routines 4 times a week. That will get you to a BMI +30 at 5"10 +

</comment></comment></comment></comment></comment></comment></comment><comment><USER14> 8% difference from normal to obese seems expected, not alarming. I don't see anything in the study that factors for exercise though it is the health advice provided in the article.

'Regular exercise linked to higher blood flow in brain' seems a more appropriate, not dramatized headline. Thank you Captain Obvious.

</comment><comment><USER15> As Alzheimer's and most other neural degenerative diseases progress body weight decreases rapidly.

I would also think, based on some people with eating disorders I've observed where the weight decreased, that a very low body weight also might have an alarming impact on brain function - not sure how surprising it would be and if really a cause and not a correlation. Probably just a correlation.

</comment><comment><USER16> Clickbaity title aside (seriously, that's the original press release title), pretty damning results. Basically a higher BMI means a higher probability to get an alzheimer's disease.

</comment><comment><USER17> Wonder if this applies the same for both "muscular" and "fat"?

<comment><USER18> Probably don't have same blood flow issues being muscular as being fat.

<comment><USER19> can you provide a citation?

</comment></comment></comment><comment><USER20> I have a hard time believing this study. Anecdotally - I have about 10 years experience in assisted living homes (read early stages for dementia and Alzheimer's) and I can't think of a single dementia resident that wasn't thin as a rail. I also can't recall a single overweight resident that had dementia. Grain of salt and all that.

</comment><comment><USER21> > FunctionHigher BMI is linked to decreased cerebral blood flow

Most people equate weight=high BMI, so the title is probably accurate for a casual audience but it's important to note the study is actually looking at BMI.

<comment><USER22> BMI is linearly related to weight, so for a given person, whose height is fixed, it's appropriate to think of this as the impact of weight....

</comment></comment><comment><USER23> The media has almost entirely ignored how the majority of young people who died of Covid were obese. Two days ago the NYT finally acknowledged this as a risk factor despite it being obvious to anyone paying attention [https://www.nytimes.com/2020/08/14/health/covid-19-obesity.h...](https://www.nytimes.com/2020/08/14/health/covid-19-obesity.html)

Being fat is an enormous risk factor for dying of Covid, but instead of a giant "Get Out and Jog" campaign we are just supposed to hunker down inside and pray for a vaccine.

Being fat is a sign of generally poor health. It hurts your immune system. It reduces your quality of life. It has ripple effects to the rest of your body.

The fat positivity movement is one of the worst movements ever to exist. There is nothing positive about being fat. It is only negative.

<comment><USER24> If I was in charge during this I would have done a huge get healthy campaign. Vitamin d for all, free gym memberships and park fees, healthy food campaign. (Plus protecting nursing homes)

It would let people feel like they're doing something to fight the disease. It would bring us positivity instead of negativity, and the health improvements would pay dividends for years.

Oh also a massive volunteer effort for healthy people to deliver food and medicine to the elderly and vulnerable.

<comment><USER25> Sounds like if you were in charge you would have done the opposite of social distancing (e.g. free gym/parks, volunteers visiting tons of people's homes, etc). This seems like a strategy that could increase the spread significantly.

<comment><USER24> Interesting point. The volunteers would have to be super careful. I'd envision leaving the food outside the door.

<comment><USER26> That's exactly what has been done in Madrid. Council organized free meals for vulnerable people, but there were many individuals that just volunteered for their neighbours.

My mother and his husband received several offers from young couples in the block to go buying groceries or make any other errands and leave them outside the door.

The vitamin D and C were sent by me through Amazon :)

</comment></comment></comment></comment></comment><comment><USER24> It's interesting that high blood pressure is linked to poor brain health outcomes (AFAIK).

Maybe high blood pressure is the body trying to compensate for reduced blood flow?

<comment><USER27> IHH. High inter cranial pressure is horrible on cognitive abilities.

If I get a spike, it can take a week to be back to normal brain function.

It puts a lot of pressure on the veins, taking them close to bursting. Body needs time to heal.

One insidious part is that exercise makes it worse. So if you exercise, pressure spikes, you need a week or two to recover.

I spent years trying to push through exhaustion, but everytime I worked out I would need weeks to recover. So I made little progress.

Proper diagnosis and medication suddenly enabled me to exercise daily. Massive life changer.

<comment><USER13> For most people, exercise _reduces_ blood pressure (post exercise hypotension).

</comment></comment></comment><comment><USER28> There are many published, referenced papers on this:

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5651104/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5651104/)

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4737453/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4737453/)

etc.

However, this is a topic that we are not allowed to discuss here.

</comment><comment><USER24> I wish studies like these would look at apoe4 status.

</comment><comment><USER29> Oxygenation is important.

</comment><comment><USER30> In layman's terms, the fatter you get the dumber you get.

A layman would also look at a country like say, America, where obesity has been on the rise for decades, and the population seems to get increasingly uneducated and insular, and deduce this to be true.

<comment><USER3> The study observed a correlation, please don't put forward a causative narrative when these could just be correlated or causative in a way different from the way you propose.

<comment><USER30> Given that obesity is the cause of a whole host of ailments, I'd say it's fine to play it fast and loose and put forward this narrative.

Is it scientifically rigorous? No, but sometimes there isn't enough time for rigor and you're better of making an educated guess than having no conclusion at all.</comment></comment></comment>