NASA plans to launch a spacecraft to Titan - the-enemy https://www.theatlantic.com/science/archive/2019/06/titan-saturn-nasa-dragonfly/592882/ <comment><AUTHOR> A flying drone is a really solid idea for a Titan lander for a couple reasons:

* The surface atmosphere density is higher than Earth's (1.5 atm)

* Gravitational force is much lower (0.15g)

* We don't know a lot about the surface composition or topography, so wheels and motors represent a challenge

* Visibility may be poor, making visual navigation tricky (though that's also a problem for a flying vehicle I suppose)

I've heard people ask about "why a nuclear power source?" Saturn is 10x as far from the sun as Earth, so sunlight is about 1/100th as bright. In addition, Titan's atmosphere blocks most of that. There really isn't any other realistic option.

I hope it works and they take videos.

<comment><USER2> In addition to lack of solar energy, I wonder if nuclear power source is necessary to keep batteries or other electronics warm enough to function properly.

Conversely, on Titan, we won't need to worry about heat sinks as everything is kept at ~94K in a bath of liquid and frozen methane. Perhaps in a few hundred years AWS's most popular region for intensive compute will be under Titan's methane sea. High spin up cost, but cheap super-conduction environment once you're up.

<comment><USER3> Hah, I was always intrigued by the idea of placing solar cells on the bright side of Mercury and servers on the dark side. I wonder what other good options might exist in the solar system.

<comment><USER4> Mercury's whisper thin atmosphere won't be much use for cooling anything, though possibly the surface would be. However, the real problem is that Mercury isn't actually tidally locked anyway.

<comment><USER5> You could have the facility move constantly to keep the facility straddled across the sunlight line. At the equator, this would require constantly moving at about 7 mph, though you could reduce the speed necessary by moving to higher latitudes.

<comment><USER6> Appears in 2312 by Kim Stanley Robinson.

<comment><USER7> They move the whole city around the planet at 7mph!! 10/10 would recommend

<comment><USER8> Sounds like Absolution Gap and/or a less annoying version of the Mortal Engines movie (please tell me the book was better than this).

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER9> > Scientists suspect that Titan might even have water—real, actual H2O—lurking > beneath its surface.

Not just a little, but a lot of water:

> The density of Titan is consistent with a body that is about 60% rock and > 40% water.

> ...

> Pre-Cassini models of impact trajectories and angles suggest that where the > impactor strikes the water ice crust, a small amount of ejecta remains as > liquid water within the crater. It may persist as liquid for centuries or > longer, sufficient for "the synthesis of simple precursor molecules to the > origin of life".[107]

[https://en.wikipedia.org/wiki/Titan_(moon)](https://en.wikipedia.org/wiki/Titan_\(moon\))

<comment><USER10> > The density of Titan is consistent with a body that is about 60% rock and > 40% water.

That's extremely misleading.

First, rocks have different densities. Sandstone weighs 2g/cc, basalt weighs 3g/cc, so a density "consistent with" 50% basalt, 50% water would be equally consistent with 100% sandstone, not to mention the possibilities of rocks with drastically different densities such as pumice or iron.

Secondly, we are pretty certain Titan has large quantities of liquid methane and/or ethane (check the same Wikipedia link) which certainly account for some of the difference in density between Titan and other rocky bodies.

So yes, there is water on Titan, but it's about as likely to be 40% water as it is to be 40% cheese or 40% iPhones, even if its density suggests a makeup consistent with that.

<comment><USER9> > That's extremely misleading.

You're right - I should have said: " _potentially_ a lot of water."

Sandstone (silicon oxides) seems unlikely given the reducing nature of the atmosphere. I'm no expert, but when liquid hydrocarbons rain down, there's not a lot of free oxygen on the surface at least. Ditto for basalt, which is about 40-50% silicon oxide. Still there could have been some process by which the interior sequestered most of the planet's oxygen, leaving what remained on the surface as water.

In contrast, liquid hydrocarbons seem plausible given the stuff rains down from the atmosphere and its density (methane ~0.5 g/mL, -162 C).

Titan's orbit provides some evidence consistent with a body that's more dense at the surface than at the core. One explanation is large amounts of subsurface liquid, but there are others:

[https://www.popsci.com/science/article/2011-04/titan- could-h...](https://www.popsci.com/science/article/2011-04/titan-could-harbor- massive-ocean-beneath-its-methane-lakes-study-says/)

There's been some discussion about the apparent massive block of ice in Titan's surface, so the idea that Titan's putative subsurface ocean could contain water isn't too wild a speculation:

[https://www.space.com/titan-saturn-moon-weird-ice- formation....](https://www.space.com/titan-saturn-moon-weird-ice- formation.html)

A subsurface ocean composed of water and liquid hydrocarbons would be consistent with everything I've been able to find so far.

</comment></comment></comment><comment><USER11> Dragonfly is a super exciting mission. Between it and the other New Frontiers finalist, CAESAR, it makes sense that Dragonfly would win because the ESA just announced their own comet exploration mission (the Comet Interceptor, which is 3 spacecraft that will loiter together at L2 until an interesting comet or Oumuamua-like interstellar object wanders into the inner solar system).

Anyway, Dragonfly: RTG-powered quadcopter to fly around Titan's low gravity and dense atmosphere. Over its 2.5-year primary mission, Dragonfly should cover ~180 kilometers of territory.

Self-promotion: If you're into space exploration, check out our weekly space industry newsletter called The Orbital Index ([https://orbitalindex.com](https://orbitalindex.com)). We're going to cover this in depth in next week's issue.

<comment><USER12> That's a _huge_ range!

</comment></comment><comment><USER13> I love this mission. From a science point of view it's probably good to send similar and well tested rovers to Mars. But to me it gets boring.

I think NASA used to get a lot of fascination from doing the seemingly impossible like flying to the moon. So I think a mission like this will be fascinating for a lot of people. Also it may spawn off a lot of technology. I hope for a submarine mission to Europa.

<comment><USER14> I think a flying mission is actually superior to a rover as it can cover far more ground and reach some sites that wouldn't be feasible for a rover. And Titan is uniquely suited to using flight to explore as its gravity is a factor 7.25 lower and its atmosphere a factor of 4.4x denser. That means it's about 30 times easier to hover and covering the same distance is at least 7 times as efficient as on Earth, besides having lower terminal velocity.

Even this relatively "inefficient" quadcopter (8 rotor) design could cover dozens of miles (~60km, more than any Mars rover has ever done in its entire mission) in a single hop (which could be recharged by the MMRTG in a single week-long night), although prudence suggests shorter hops at first. That means in principle over its ~10 year lifespan (assuming it can last as long as Cassini did...) it could nearly circumnavigate the entire planet (diameter of ~5000km, day period of about 16 Earth days) while visiting dozens of sites. Granted, range will likely be much more modest as the mission operators will be focusing on not losing this valuable asset, but it shows just how powerful the ability to fly could be. It can visit more sites than all the surface robotic missions to Mars combined. In that sense, it's a _fantastic_ scientific value. And I think the public will absolutely love it.

Information from the Dragonfly proposal document: [http://dragonfly.jhuapl.edu/News-and- Resources/docs/34_03-Lo...](http://dragonfly.jhuapl.edu/News-and- Resources/docs/34_03-Lorenz.pdf)

<comment><USER15> > over its ~10 year lifespan (assuming it can last as long as Cassini did...)

Cassini wasnt exposed to solvents, rocks and didn't have moving parts (at least not to keep it aloft). Have they made a public statement about lifespan?

<comment><USER14> Yes, the planned mission time is 2.7 years. MMRTG should provide sufficient power for at least 8 years.

</comment></comment></comment></comment><comment><USER16> It's interesting that there is no existing (or planned) launch vehicle that could perform a direct injection for this mission. Getting to Saturn is really, really hard, and without multiple gravity assists from the inner solar system it would be simply impossible.

Too bad it results in an 11 year transit time though! Flying direct would save almost 8 years of that...

<comment><USER17> > _Getting to Saturn is really, really hard_

Why is that?

<comment><USER16> Just the speeds required. This mission will effectively have a speed of about 17km/s _faster_ than the speeds just to get to low Earth orbit after its final gravity assist.

</comment></comment></comment><comment><USER18> This is great news. When Huygens landed on Titan, the images sparked my interest in physics and planetary science, and eventually I went on to do research in solar physics.

</comment><comment><USER19> NASA's PR: [https://www.nasa.gov/press-release/nasas-dragonfly-will- fly-...](https://www.nasa.gov/press-release/nasas-dragonfly-will-fly-around- titan-looking-for-origins-signs-of-life/)

NASA's announcement video: [https://youtu.be/xn3-0a19sC8](https://youtu.be/xn3-0a19sC8)

</comment><comment><USER20> _What's Titan look like this time of year?_

[https://youtube.com/watch?v=lZa83dTf4JA](https://youtube.com/watch?v=lZa83dTf4JA)

Exciting to see reality (almost) following fiction. Gattaca is an excellent film, if you haven't seen it.

</comment><comment><USER21> Mad props to the scientists and engineers making something like this possible. In an alternate life I would choose to be an astrophysicist or rocket engineer. Hopefully I will be more intelligent in the next life.

</comment><comment><USER22> Associated read: "Titan" by Stephen Baxter. Hard SF describing a manned mission to Titan using present-day level tech; great attention to detail, but be warned that the overall tone is rather depressing.

Myself, I'm absolutely fascinated by the confirmed hydrocarbon lakes and rivers on Titan and can't wait to see actual optical images from up close (so far we only got synthetic-aperture radar images [0]).

[0] [https://en.wikipedia.org/wiki/Titan_(moon)#Lakes](https://en.wikipedia.org/wiki/Titan_\(moon\)#Lakes)

</comment><comment><USER23> I can't believe it's been that long since Huygens was sent to Titan. I remember listening to some radio show (NPR?) that was broadcasting the touchdown live.

Also, it's interesting that since they can't study Titan very well visually (you can't point a telescope at it and map the surface like you can with Mars) they're planning on sending a rover that can cover far more distance since they have less idea what will be "interesting" beforehand.

<comment><USER24> I worked on prototypes of the experiments in the Surface Science Package at uni in 1991 - boy do I feel old!

Even then we were speculating on flying or floating probes for future missions there. At the time it was assumed that the surface could well be entirely liquid.

</comment></comment><comment><USER25> I'm interested to see how this mission is couched from a PR standpoint (specifically the long long transit time). Emily Lakdawalla from the planetary society had a good tweet related to this: [https://twitter.com/elakdawalla/status/1144492247032799238?s...](https://twitter.com/elakdawalla/status/1144492247032799238?s=20)

</comment><comment><USER26> I also found a really good write-up of the mission here: [http://www.4erevolution.com/en/dragonfly-un-drone-a- propulsi...](http://www.4erevolution.com/en/dragonfly-un-drone-a-propulsion- nucleaire-pour-explorer-titan/amp/)

</comment><comment><USER27> It is nice that multiple public sector agencies worldwide are doing space travel now, with the private sector close behind.

Relying solely on NASA and the political funding machinations of the White House and Congress would put our understanding of the planets very far behind.

<comment><USER28> I'm confused by your comment. this is absolutely a NASA mission, subject to all the whims of congress that any other is.

APL has long bid on missions and instrument proposals just like other institutions.

<comment><USER27> Its just a statement of fact.

NASA likely wouldnt even have revisited this moon without the European probe taking pictures under the atmosphere

It is nice that multiple public sector agencies worldwide are doing space travel now

<comment><USER28> Ah, I see. I agree, worldwide collaboration and competition is very healthy for a space program.

</comment></comment></comment></comment><comment><USER29> >To protect the hazy moon, engineers deliberately shoved Cassini into Saturn, a gaseous planet incapable of hosting life.

Can we be 100% sure there isn't life.

<comment><USER30> We can be sure that Earthling life wouldn't survive in Saturn, thus posing no threat to hypothetical Saturnian biology.

<comment><USER31> _Almost all_ Earth life sure, but I wouldn't bet on absolutely none being able to survive. NASA can't even completely sterilize their vehicles and payloads already.

</comment></comment></comment><comment><USER32> They are planning to send it up in 2026? What are they going to be doing for 6+ years?

<comment><USER33> They just announced it today. They don't have a probe yet. They have to design and build and test all of the equipment and systems that are going to go into space. I think it's pretty reasonable for this to take 6 years.

</comment></comment><comment><USER34> NASA is really good at planning future missions. Implementing them? I've heard hundreds of fantastical half-baked ideas and very few of them materialize over the course of my 46 years on earth.

<comment><USER35> Eh, almost every NASA robotic mission that has gotten this far in the design and selection process has also flown. They're way past the "fantastical half- baked idea" stage. The financial reality is that NASA can only finance one or two billion-dollar missions per decade, and the competition is rather fierce. To be selected as _the_ New Frontiers class mission of the late 2020s is a big deal, and you can be sure that at this point the proposing team has made a very solid case for their mission.

<comment><USER14> Yup. The robotic program has a very good track record of successes, even for crazy stuff like the Mars Science Laboratory's sky crane descent stage: [https://m.youtube.com/watch?v=Ki_Af_o9Q9s](https://m.youtube.com/watch?v=Ki_Af_o9Q9s)

It's the human spaceflight program that has had the, um, difficulties. There are signs of hope, though.

</comment></comment></comment><comment><USER36> Venus and Titan have in common that probes landing there tend to only operate a few minutes before failing due to the extreme conditions.

A helicopter sounds great, but perhaps it would make sense to try to simply make a probe that can stay alive there long enough to do anything other than send a couple pictures back.

<comment><USER14> This is not true. The only reason the previous probe (Huygens) only lasted a few hours is because it was battery powered (and the battery wasn't particularly large). This probe will carry a power source powered by the radioactive decay of Plutonium 238 (virtually all the radiation being alpha particles, which are easily blocked by the casing of the power supply and thus will not hurt the electronics or ground crew) that can provide 50-100 Watts of power for years or even decades.

<comment><USER24> As I mentioned elsewhere in this thread, before Huygens we expected that the surface might well be entirely liquid, giving us at best only a few minutes to run the experiments and return the data before it sank. There was no point carrying too much battery capacity in that case.

<comment><USER14> No. Huygens was designed to float and last hours. The battery capacity is why it lasted so short.

</comment></comment></comment></comment><comment><USER37> I'll be 43 when this craft arrives there. Damn.

<comment><USER38> I'll be 43 in March. Damn.

</comment></comment><comment><USER39> What. How are they going to detect life on titan? They can't even detect life on mars. I mean to say, even when we know the kind of life we are looking for we get confused about how to confirm or deny its existence. So they want to design a small flying drone that works in extremely hostile conditions, that also has the kinds of sophisticated instruments needed to look for life? And not just life, life of potentially a completely unknown form, given the widely different surface conditions. This just seems like a weird mission. Finish up the Viking labelled release experiments on mars first, then go take a look in the mid Venusian atmosphere. Then take a gander at europa.... Weird mission

<comment><USER40> > Finish up the Viking labelled release experiments on mars first, then go > take a look in the mid Venusian atmosphere. Then take a gander at europa

This is exactly why I like HN. Here, you have the true experts contributing valuable science with their credentials laid bare, as opposed to the pencil pushers at NASA who probably only approved this mission because it sounded cool.</comment></comment>


Show HN: Rotate-To-Snap - <AUTHOR> http://www.maximiliankiener.com/digitalprojects/rotate/

<comment><USER2> This is a neat concept. It could potentially solve the vertical videos problem we have lately with smartphone cameras in everyone's pockets. My only nitpick is the "tap to take a picture/hold to record a video" control scheme. A viable alternative would be: tap to focus, tap and hold for a menu (think Galaxy Note 4 Air Command) where you can toggle flash, choose photo or video, etc.

<comment><AUTHOR> I'm borrowing from snapchat here which uses a similar concept (tap for pics, hold for video) and tried to cut/avoid additional steps. As for focussing: why must focus and trigger be two distinct actions?

<comment><USER2> I sometimes play with the focus when I'm taking videos. Sometimes I'd want the focus to be very up close at first and then focus more on the background while recording. Also, it's not always easy to tell if the object is too close/far to focus on, so the picture might not come out too well.

If you're thinking Snapchat and the video lasts until you release, the focus could perhaps be controlled by dragging over the area rather than tapping.

Overall, the focus isn't that big of a deal, but, to make as many people as possible happy, I would find a way to include as many features as possible. Flash is also a very important feature that wasn't accounted for. On top of that, how would the user go about toggling between the front and back facing cameras?

<comment><AUTHOR> Good Points. Maybe something like a Lytro-Focus-slider could be implemented.

Front/back and Flash can be adjusted on the panel I the left.

</comment></comment></comment></comment><comment><USER3> > Tap to snap / hold for video

How do I focus?

I've been working on an app that utilizes this user interaction, and what I've come up with is double tap to take a picture. Don't focus until you're sure there's no second tap (a few hundred ms). Or you could always just add a simple camera button, which solves this problem.

<comment><USER4> > How do I focus?

I've assumed that "Tap to snap..." works on the (right) button area only and tapping the photo triggers focus. This isn't clear though.

<comment><AUTHOR> Thank you for the feedback. I hadn't thought that it could be interpreted that way. The idea is that it tapping and holding for photo/video works anywhere on the screen. I also would like it to focus on tap (shooting = focussing)

</comment></comment></comment><comment><USER5> > With the advent of bigger screens on our mobile phones, typing in portrait- > mode with two hands becomes easier

True.

> and landscape mode for keyboards less of a necessity.

Also true, but neither means I would forgo my landscape mode, especially when I can hold down the camera icon on my iPhone for the same effect.

Nice idea, it's just that more elegant solutions exist :)

<comment><USER6> Yeah, the regular camera on the iPhone is perfect. This explores how to trigger it differently in apps though (like Instagram or whatsapp). I wanted to find out if it's easier to learn a gesture than to learn tap sequences. What to you think?

<comment><AUTHOR> Gestures replacing taps/clicks (desktop metaphors) was one of the things I wanted to explore with this.

</comment></comment></comment><comment><USER7> This look like a very handy feature/app.

How to actually use it?

<comment><AUTHOR> It's an idea for communication/social networking apps, that have a camera feature built in. It is not available in any app so far, but I'd love to see someone pick it up.

Basically turn the phone sideways and the camera turns on. Turn it back to portrait and you are back in your app.

<comment><USER7> Yes, this is a super idea. i am in love with feature already!! hopefully someone develop this feature soon.

Cheers, and thanks for sharing.</comment></comment></comment>


Is Zerigo (DNS provider) shutting down? - <AUTHOR> I've received an email (purportedly) from Zerigo, saying:

  Dear Zerigo Customer,

  Effective April 30, 2017, Zerigo DNS will shut down permanently. We thank you for your
  business and apologize for this inconvenience.

  If you are managing a public Web site or other Internet domain using Zerigo DNS, you must
  migrate to an alternative DNS provider prior to April 30th, 2017 in order to prevent a DNS
  error message from displaying when a user visits your website.

 They go on to suggest migrating to Route 53. However, I can't find anything on their website, only a Reddit thread (https://www.reddit.com/r/sysadmin/comments/5nt8dh/zerigo_shutting_down_dns_service/). Does anyone have more information on this?
Edit to add: the email looks legitimate at first glance, and unlike the one on the Reddit thread does not come from "Rexx.com". It hasn't fallen into Gmail's spam box either. <comment><USER2> Bummer. We (easyDNS) were pursuing the idea of acquiring Zerigo, I guess that isn't going to happen now....

[https://www.easydns.com/blog/2017/03/14/our-efforts-to- acqui...](https://www.easydns.com/blog/2017/03/14/our-efforts-to-acquire- zerigo-have-fallen-through/)

</comment><comment><USER3> There is a link in the email to "view this email as a web page" which redirects to a page on 8x8.com (the parent company of Zerigo), so I assume it's legit.

</comment><comment><USER4> Yes, we had the same email today. Their support email address bounces right back. One to Sales didn't but I have v low expectations of getting a reply. Can't find anything on their site or 8x8...

</comment><comment><USER5> I just called Zerigo's support hotline, they confirmed that Zerigo is EOL with April 30th. 8x8 (Their parent company) wants to go into a different direction.

</comment><comment><USER4> Ah, hang on. The link to Amazon Route 53 is bogus...

<comment><USER6> Just got this email forwarded to me, and I also got the one from Rexx a while back. This one looks legit but those URL's in this email are a huge red flag.</comment></comment>


Almost entire EU now violating Brussels cookie privacy law - <AUTHOR> http://www.theregister.co.uk/2011/05/26/european_cookies_law_ignored/

<comment><USER2> There is no 'EU law', there are various levels of different EU policy documents. Directives should be implemented (somehow) in the member states legislatures, but it's not that unusual that they are not met within the deadline (or even in a way that was intended). It's an obligation for the governments, who are bound by the EU treaties, not the citizens and businesses (though in theory, you can sue your government for not complying, if it hurts you somehow, but the european court is still just an international treaty). Law is something that directly binds everyone in the given country, EU directive is not a law as such.

It'd be nice if at least someone could tell the difference here. (Especially when he is writing an article about it.)

<comment><USER3> _There is no 'EU law'_

Pedantically, The EU has 'Regulations' that become law immediatly in all member states. (cf. <http://en.wikipedia.org/wiki/Regulation_(European_Union)> ). However EU Directives (which this 'cookie law' is), are much more common.

<comment><USER4> I find this Wikipedia article misleading and insufficiently nuanced. Regulations are still subject to the Van Gend en Loos criteria for direct effect. I think it's fair to say that EU 'law' is sufficiently different in nature from national 'law', even if EU regulations will usually derogate national law, to (in common usage, e.g. in the media) not talk about 'EU law' exaactly because of the risk of conflating it with the common conception of 'a law'.

</comment></comment></comment><comment><USER3> This article basically says "Nearly all EU Countries have not implemented a EU Directive on cookies"

This is not new. Many countries commonly are late with implementing EU Directives.

</comment><comment><USER5> I hope sites will be allowed to write a cookie saying "this user has declined cookies". Otherwise, users will be prompted over and over, and will eventually give in.</comment>


Chrome Extension That Adds Favicons Next To Links - <AUTHOR> https://chrome.google.com/webstore/detail/oejcldhmenjoefcgdjpfodllfciipbda

<comment><AUTHOR> Based off <http://news.ycombinator.com/item?id=4028603></comment>


Recordtype for Python: mutable namedtuple with default values - <AUTHOR> http://pypi.python.org/pypi/recordtype/

<comment><USER2> What about performance? One of the reasons to use namedtuple is performance, esp. memory-wise (afaiu nametuple stores field names in class definition, which can save a lot of space compared to lists of dicts). I would expect recordtype to be better than dict but not as good as namedtuple. It would be nice if author posted some benchmarks…</comment>


Unprecedentedly wide and sharp dark matter map - <AUTHOR> https://phys.org/news/2018-03-unprecedentedly-wide-sharp-dark.html <comment><USER2> I'm confused. This article says it's about a dark matter map, but it spends most of its time talking about accelerated expansion, the cause of which is labeled dark _energy_ , not dark matter. Dark matter (I am given to understand -- IANACosmologist) acts on a much smaller scale to hold galaxies together which would come apart under the gravitational influence of visible matter alone. What am I missing?

<comment><USER3> Dark matter and dark energy are both fudge factors to explain gravitational observations that don't make sense. Dark matter corrects for the speed distribution of stars around galaxies and dark energy for cosmological expansion. The observations here collect indirect observations of dark matter via a different method and postulate that the discrepancies from what was predicted may obviate the need for dark energy. (Disclaimer: I am not an astrophysicist)

<comment><USER4> Fudge factors - lovely. As one physicist put in a public lecture, if scientists use the term "dark" then they are discussing something that they have no clue about.

<comment><USER5> I don't see why there is such an agitated response to the term "fudge factor" (I see downvoted comments, several knee-jerk defensive replies, etc)

It's important to embrace one's ignorance -- especially when we're at the absolute frontier of human knowledge. If you've seen some of the calculations involving dark matter's effects, calling it a "fudge factor" is a fair characterization, and one that is acceptable among physicists. We postulate a component with certain properties that fudges our calculations in just the right way to match some indirect observations (circumstantial evidence).

We still don't know what is the thing which produces the behavior we expect, and what its properties might be. We're still seeking evidence that would seal the deal, so to speak. It's true that several such fudges historically turned out to be profound stepping stones, but till we get there, "fudge factor" is absolutely honest.

I'll leave some Richard Feynman quotes here:

* "The first principle is that you must not fool yourself — and you are the easiest person to fool."

* "I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong. If we will only allow that, as we progress, we remain unsure, we will leave opportunities for alternatives. We will not become enthusiastic for the fact, the knowledge, the absolute truth of the day, but remain always uncertain … In order to make progress, one must leave the door to the unknown ajar."

<comment><USER6> > We postulate a component with certain properties

versus

> We still don't know ... what its properties might be.

Which is it?

> stepping stones

Observation of missing momentum-energy in Lithium-6 decays (Pauli, 1930 [1]) until direct detection of the (electron anti-)neutrino (Reines and Cowan, 1956) took 26 years and a number of false starts including failures to detect neutrinos in detectors at nuclear weapon tests and nuclear reactors, where the production of neutrinos was expected. Observation of solar neutrinos took a further thirteen years (Davis, HOMESTAKE, 1969).

Neutrinos are in the strictest sense dark matter: they do not feel or participate in electromagnetism. However, they also have a tiny rest mass, so it is hard to keep them from carrying their momentum-energy away at relativistic speeds. Their fast motion makes them too "hot" to avoid smearing out visible matter during structure formation, so they are not a candidate for the momentum-energy missing in galaxy cluster interactions. On the other hand their fast motion makes it relatively easy to spot atomic recoils (or really the latter's ionization energy) when neutrinos interact with the matter in a detector. That's why detectors were placed at extremely violent neutrino- producing events: the hotter the neutrino, the easier to detect it.

The standard cosmology predicts a relic neutrino field comparable to the relic photon field called the Cosmic Microwave Background. These relic neutrinos were relativistic ("hot") in the early universe, but have cooled down adiabatically to about 2 kelvins, just as the hot photons in the CMB have cooled down to a bit under 3 kelvins. The Cosmic Neutrino Background is vital at high redshift (z > 3000) and there is good indirect evidence for it (BBN element abundance, suppressed early small-scale structure formation, damped acoustic oscillations of the CMB). However, it is extremely difficult to detect relic neutrinos with our current level of technology (although experiments like KATRIN will try: [https://www.katrin.kit.edu/](https://www.katrin.kit.edu/) and [https://arxiv.org/abs/1304.5632](https://arxiv.org/abs/1304.5632) ), because the recoils from slow-moving neutrinos will be smaller than those from relativistic neutrinos. These relic neutrinos are _literally_ Cold Dark Matter.

So there have been stepping stones on the road towards direct detection of a form of cold dark matter. It is not the cold dark matter working cosmologists or galaxy astrophysicists are looking for to explain galaxy-and-higher-scale momentum-energy anomalies (notably because its rest mass is too low), but it's suggestive of something more than "fudge".

There are options other than a heavy neutrino-like particle or even particle dark matter for galaxy-scale and even cluster-scale problems; indeed, a relativistic "left hand side" term in the Einstein Field Equations is plausible -- one would tend to treat that as a modification of gravity. However cold dark matter is needed to explain several fine features in the cosmic microwave background, and those features are ever sharper in the results of each generation of CMB observatory since BOOMERanG.

Finally, returning to the ~ 40 years between observation of anomalous results to direct detection for neutrinos: Vera Rubin et al.'s galaxy rotation curve paper was published in The Astrophysical Journal in 1980. So the long gap between the apparent need for dark matter and today does not seem so long compared to the long gap between the apparent need for a light spin-1/2 particle [1] and direct detection.

> "fudge factor" is absolutely honest

How exactly does this honesty scale work?

Apropos honesty and fudging things, who exactly is in each of the six instances of "we" (excluding the ones in the Feynman quotes) in your comment?

\- --

[1] I think Pauli's letter is interesting in itself. An English translation follows on the second page: [http://microboone-docdb.fnal.gov/cgi- bin/RetrieveFile?docid=...](http://microboone-docdb.fnal.gov/cgi- bin/RetrieveFile?docid=953;filename=pauli%20letter1930.pdf)

<comment><USER5> IMHO, we seek models explaining certain observed cosmological behavior. As long as plausible models for dark matter range from WIMPs to primordial black holes or axions and what not, I consider it unreasonable to claim that we know what dark matter is, and all it's properties.

Eg: if all dark matter experiments (direct and indirect detection) returned null results over the next several decades, then dark matter would still be an open puzzle.

With regards to "we", I think it applies equally well to any group as small as physicists working on DM, to all scientists, or everyone discussing the subject. I expect most particle/astro physicists I've interacted with to find those statements very reasonable.

</comment></comment></comment></comment></comment></comment><comment><USER7> Suppose the gravitational attraction of particles, like spin, was signed, such that like attracts like, and unlike repels unlike? Because of the weakness of gravity, every other force would dominate at the local scale. But the prevalence of one or the other sign in a region (at the galactic scale) would vary - as there would have been a (very gentle, as gravity is weak) "sorting" in the early universe, as like signs attracted and unlike signs repelled. "Dark matter" would be variation in the prevalence of one sign or the other.

How would one test such a model?

<comment><USER8> On the galactic scale, my hunch is that the sorting dynamic would be very strong, and you would basically have g+ and g- galaxies. Which would be very interesting, but doesn't solve the dark matter issue.

I think that this would also create a lot of other complex behavior that we don't see. For example, I think we would expect to see many cases of two galaxies or even two galaxy clusters pushing away from each other, because one is g+ and the other g-.

<comment><USER7> Expansion does have the appearance of "pushing away". But, as noted, to explain "dark matter", one would observe "anti-gravitational" separations in inert gases at local scale, which has never been reported.

<comment><USER8> Ah yeah nice idea. However, the expansion we see is stronger when things are farther away. Gravity gets weaker at a quadratic rate as distance increases, so I don't think opposite gravity signs could be contributing significantly to the observed expansion.</comment></comment></comment></comment>


Why I Defaulted on My Student Loans - <AUTHOR> http://www.nytimes.com/2015/06/07/opinion/sunday/why-i-defaulted-on-my-student-loans.html?_r=0 <comment><USER2> Why do people like this absolve themselves of all responsibility. You made the choice to take out all those loans and attend a liberal arts college, good for you and now it is time for you to pay up.

While you got to party in College on someone else's dime, I worked 80 hours per week and built my career. I'm sorry your choice didn't pan out the way you thought it would but I'm really getting tired of the idea that people should just be able to walk away from student loan debt because they believe it is "unfair."

<comment><USER3> The truth is these kids aren't really adults, and no one along the way is incentivized to stop them and say "hey, you may be making a really terrible decision here." Instead, everyone encourages them. English major? Great! No major? Even better! You have time to decide! $100k in debt? A degree is worth it!

Thankfully I had programming skills to fall back on, but when you're 18 years old and you're surrounded by people giving you awful advice that could ruin your life, you may not be able to recognize it.

<comment><USER4> "when you're 18 years old and you're surrounded by people giving you awful advice that could ruin your life, you may not be able to recognize it"

I remember being 18 and I was terrified of loans, or of any kind of arrangements that could limit the options of my future! Advices, even ones that come from well-intended people, weren't worth much for me if they weren't supported by detailed plans in which I would end up OK. Receiving such insurance plans proved to be next to impossible, because and as you may presume, those who seriously suggest you mortgaging your life aren't the most forward-looking people!

...so no, I don't sympathize with that naive kid not thinking straight about his own future. I actually feel that this kind of practice represents one of our time's laws of natural selection.

</comment></comment></comment><comment><USER5> I think tuition trends are appalling and it's a real problem that so many students leave college saddled with debt that will drag them down for a decade or more. (It's also a little insane that even bankruptcy can't shed student loan debt.) However, it's really hard to sympathize with someone who went to Columbia to get not just one but three degrees rather than attend a state university because he "deserved better". Ten years of loans to attend a school that costs over $50K/year (today) and then playing the victim?

This seems a lot like buying a Ferrari because you need a car, instead of doing the sensible thing and getting a Civic. Sure, you've got crippling debt. But it seems entirely self-inflicted.

</comment><comment><USER6> These kinds of op ed pieces are always shocking in the way they drip with entitlement. He quit his job as a shoe salesman, where he would be a district manager if he stayed he'll have you know, because he was just too good for that kind of job.

Why does he think that? Why does he think himself somehow above the other people selling shoes, and indeed the district managers of shoe-selling operations? Does he really think other people selling shoes couldn't have gotten a liberal arts degree from Columbia if they were willing to take on foolish amounts of debt?

</comment><comment><USER7> These entitled assholes and their liberal arts degrees. Why does this guy think that the State has to pay him to enjoy 4 years of reading whatever works of literature he found amusing. If he doesn't get any skills that make him employable ... then we the citizens of America have to subsidize his 4-year party?

Maybe this sir should have thought about what he was learning in school. And if he was too young to think about that at the time he went to school, maybe we shouldn't be giving him the power to make those spending decisions at that age--or maybe we should be withholding loans from students pursuing such worthless degree programs.

This idea that the world must mold itself to the interests of liberal arts students or the hysterical theories of liberal arts professors--oh reading the classics will expand your mind!--is a bunch of bullshit.

Of course the liberal arts faculty want you to keep buying into the failed state that is their department. That's the only way they keep chugging along. But employers have long ago figured out that they want to hire smart kids. And smart kids were smart before they entered these programs.

<comment><USER8> "Of course the liberal arts faculty want you to keep buying into the failed state that is their department"

I think you hit the nail on the head here. I distinctly remember almost every intro class I took the professor would try to sell me on the fact that it would be the greatest degree ever. Unfortunately, while some areas of study may be interesting, they are not always a good ROI and I think that is what alot of college kids don't understand.

<comment><USER6> To be fair to the professors, they wouldn't be teaching intro to whatever if they weren't genuinely enthusiastic about the subject.

Also, while the ROI on some majors is terribly negative over a large population, that choice has likely worked out very well for the professors teaching the class. A tenured position at a major university is the closest you're ever going to get in life to a sure thing.

</comment></comment></comment><comment> a-dub It all went to hell in 2005 because of this little gem:

[http://en.wikipedia.org/wiki/Bankruptcy_Abuse_Prevention_and...](http://en.wikipedia.org/wiki/Bankruptcy_Abuse_Prevention_and_Consumer_Protection_Act)

See, there are two primary forms of financing for higher education: The heavily regulated federal market, where the federal government guarantees the loans, but also maintains rules that ensure that repayment is affordable by way of myriad flexibility in repayment (including a very reasonable $50k total cap in principal lended), and the private market which is very much similar to other forms of consumer financing.

The BAPCPA changed the rules and handed out protection to private lenders outside of the federal system that made private student loans special in that they became nondischargable in bankruptcy.

Now take a room, throw in some profit hungry lenders drunk on an elixir or reduced risk prepared by the federal government, a bunch of kids that aren't old enough to drink, some old school notions about the value of expensive college degrees, more old school notions about the value of liberal arts degrees and a pile of overzealous university administrators looking to expand by pushing overpriced preparation for vaporcareers and guess what you get, this mess.

<comment><USER9> Finally an actual factual and interesting comment instead of moralizing. Apparently 16 year olds cannot drink or have consensual sex (in most states) but are capable of taking out loans for hundred of thousands of dollars and make accurate predictions of the viability of various careers.

</comment></comment><comment><USER10> I don't understand how people can be so sure that they've made the right choice: If society isn't willing to give you anything for it, how are you sure it's your 'usefulness in life'? Usefulness to whom?

How is this person supposed to be a sympathetic character, when he paid none of the investment towards higher education, reaped a number of the benefits, and then lumps people who played by the rules/lived within their means as sad?

The sheer level of entitlement and narcissism displayed by acknowledging "I could give up what had become my vocation (in my case, being a writer) and take a job that I didn't want in order to repay the huge debt I had accumulated in college and graduate school" but then going on to shirk the debt for your own personal benefit is disgusting.

<comment><USER11> "If society isn't willing to give you anything for it, how are you sure it's your 'usefulness in life'?"

Because usefulness isn't measured only in money.

(Think of the children! No, really. They cost a ton, no guarantee they'll live to support you in your dotage even, but people still have them.)

<comment><USER10> Society gives you a ton of validation, support, and encouragement to pursue having/raising children well. I'm not saying usefulness is only measured in money, but money is definitely one of many barometers to gauge if you're doing something useful. Seeing as this article specifically discussed his career, I think that money is a pertinent measure of what society would like you to do/you should do to fulfill your obligations.

</comment></comment></comment><comment><USER12> Sociopath Explains Why He's Above Paying Off His Debts: [http://freebeacon.com/blog/sociopath-explains-why-hes- above-...](http://freebeacon.com/blog/sociopath-explains-why-hes-above-paying- off-his-debts/)

</comment><comment><USER13> I'm sorry, but if you want to go to college, it's all a business. The experience you get, the paper you receive guarantees you nothing. You make college what you will. Banks and loan companies offer to lend you money with the intentions of running their own business. I graduated with $40,000 of debt. I got a job making $12 an hour as a programmer, way underpaid, and knew there was no way I was going to be debt-free ever, or so I thought. For a year, I did my best, got one raise, but I couldn't take it anymore, and decided to apply for new jobs, considering I had a college education, I had an advantage above many others. I applied and got 2 jobs. I worked about 18 hours a day for almost a year, and after all was said and done, it took me about 2 1/2 years to pay it back. After that, the IRS decided to come after me with a slap in the face asking for $6,000. I eventually paid off my student loans AND the IRS, and the next year after that, I ended up owing the IRS $3,000 more, but that is life and reality. I paid it off, changed my w4 so they take everything from me up front in hopes that I owe nothing anymore, and I am comfortably working in a job I love debt-free. Welcome to life. Defaulting does make you delinquent in the eyes of the law, or the loan companies, as well you should be. If I lent you $10,000 and told you I was charging you 6% interest, I'd expect to be paid back the original $10,000 I lent you and all the interest you accrued for each year you couldn't afford to pay me back. Welcome to the real world, my friend. Welcome to owning up to your responsibilities. Oh wait... you didn't do that.

I do agree with you that education is overpriced and the value for your buck is insane, but people are paying it, and those who do, especially those who are studying the right fields of science, mathematics, medical, engineering, and computer science are coming out on top and making great money. With the exception of several degrees in which a further education is necessary, those who study anything else tend to find it harder and rougher to get jobs. Truth about the workforce is: YOU NEED SKILLS. YOU NEED TO FIND SOMETHING THAT MAKES YOU IN DEMAND! Unfortunately, the college degree helps you get into the door, but it's what you truly have to offer that brings you much further in life. In my case, I am extremely good at picking up new computer languages, from computer programming to web design. Add value to yourself by acquiring new skills and selling them to companies.

</comment><comment><USER14> My first reaction was the same as many comments below. "He made a poor choice and now doesn't want to take responsibility."

But...

I was talking to my sister the other day, who just graduated from an Ivy League school. All her life she's been in accelerated programs with other well-to-do kids. I realized that she has always interacted with people with above average intelligence, above average connections, above average wealth. I'm betting that many HNers have at least one of those privileges. The overwhelming majority of people do not.

Over time I see a recurring theme: that people who are uneducated and poor are so easily taken advantage of. I've seen single moms lease $30000 SUVs for 600 a month. People who, after work, sit in front of the television and spend -all their money on the weekends.

The world makes it so easy to fuck up. I always have to remind myself, a person with the single privilege of above average intelligence: what is obvious to me is not obvious to others. Yes, books are ubiquitous and cheap. Yes, people should know what they are signing up for. Yes, debts should be paid. But perhaps these things some of us take for granted as simple realities are not so obvious for an overwhelming majority. It is not their fault.

<comment><USER15> >I've seen single moms lease $30000 SUVs for 600 a month.

The alternative is to tell them they aren't educated enough to take out a lease.

Imagine how this would be applied to other scenarios. Say... telling someone they aren't educated/financially secure enough to have children.

</comment></comment><comment><USER16> It's interesting that what we consider to be barbaric and primitive was a poor lower class of people who were uneducated while their lives were indentured. Now we have educated people who's lives are indentured.

<comment><USER17> Do you think the writer of this article actually got educated? I would argue they have not been educated, nor have they matured.

And that right there is an indictment of the college system.

</comment></comment><comment><USER18> Hey why not? The system is, in a word, fucked. Something huge is needed to shake it up, and a massive wave of irresponsible defaults would certainly focus efforts.

</comment><comment><USER19> For a variety of opinions about this, don't overlook the 697 comments at the article itself.

</comment><comment><USER20> tldr; too bad that the majority of student loans are issued by the US government and filing bankruptcy doesn't clear them from your credit history...</comment>


Timeline of the ChainCoin Scam – Massive Cryptocurrency Pump and Dump Scheme - <AUTHOR> https://storeofvalue.github.io/posts/timeline-of-the-chaincoin-scam/ <comment><USER2> What country is this guy from? This is exactly the type of thing that the SEC would go after. Replace ChainCoin with any penny stock and this story has been told countless times. Only new angle is YouTube videos and Slack channels instead of boiler room call centers.

<comment><AUTHOR> Daly City, San Francisco, Cali

</comment></comment><comment><USER3> ChainCoin has no value proposition, nothing to differentiate it, and the dev team abandoned it a long time ago, so why would anyone purchase this crypto? It's the same with stocks; you have to be able to understand the financials, product, roadmap, etc. of the company you're investing in.

I've purchased a few altcoins with differentiation and solid dev teams behind them. And it's still a gamble; I expect most to die off.

<comment><USER4> My current picks are siacoin (devs seems smart, but had a few missteps, storage could be a real market in the cryptocurrency space), monero (seems like they're doing anonymity right), litecoin (potential for LN first mover advantage) and bitcoin (pure network effect). Care to share any of yours?

<comment><USER5> From what I understand, SiaCoin has almost no customers.

<comment><USER6> Yes. To put it in startup terms, SiaCoin has an MVP and is post Series-A but is still building out the product.

Storj, which is in the same space, is a couple year ahead and is just starting to try and get traction (but had a management shake up)

The most serious alt coins are very much like startups.

Factom, which is sort of a digital notary service, seems to have been working for several years on their platform and only just recently picked a market- Mortgages- Claiming they want to prevent the problems that happened in 2009 by making auditing and verifying mortgage documents better. They closed their Series A last year, but did their ICO a couple years before that.

</comment></comment></comment></comment><comment><USER7> I noticed the huge price swings of this orphaned coin over the last month ... looked very suspicious for a coordinated pump and dump. What I didn't know was that this was being done by a youtuber who basically stole money from his own followers through this scam. What a scumbag.

<comment><USER8> There was a not-dissimilar scam orchestrated by some popular Youtube channels last year, also mostly targeted at their own followers and fans: [https://www.youtube.com/watch?v=_8fU2QG- lV0](https://www.youtube.com/watch?v=_8fU2QG-lV0)

They created a Counter-Strike "lottery" website and uploaded a lot of videos of themselves winning big, while never disclosing that they were the secret owners of the site. Of course, their supposed recorded lottery winnings were staged as a way to drive traffic and money to the site.

</comment></comment><comment><USER9> Cryptocurrencies are best described as being like penny stocks - they don't represent any underlying value or investment, meaning that prices are low and large gains can be realised through a small change in price - making them vulnerable to people manipulating investors as part of a pump and dump scheme.

From the Willy bot through to the latest ICO craze, the whole cryptocurrency scene is riddled with people engaging in pumping prices - which means that any reverses in price hit sentiment hard and cause price shocks, something I think we're going to be seeing a lot more of over the next year or so...

<comment><USER10> "they don't represent any underlying value or investment" \- You should try sending money to a friend or relative in a foreign country. You'll love the cost of what should be nothing more than a basic electronic transaction.

<comment><USER11> People who say there is no use case for bitcoin or they have no value tend to be in places where there is a somewhat reliable banking system and they do not use that banking system to transfer money internationally, because even a good banking system has a very high charge for international transfers, and as this is usually a flat fee it makes it very expensive for small transfers. However I have seen some places that charge a flat fee plus a %age of the total, which means large transfers are also relatively expensive.

<comment><USER12> Bitcoin is volatile and transactions are slow. This means it's not really fungible for general purpose money.

You bring up a good niche that it can fill, though.

<comment><USER13> I wouldn't call the whole of China a niche. International transfers from there aren't expensive but they're mostly impossible by official means. Banks don't allow citizens to send money overseas except for a few specific and verified reasons, which importantly don't include gifts to family members or buying things (eg real estate).</comment></comment></comment></comment></comment>


Services, Microservices, Nanoservices – oh my - <AUTHOR> http://arnon.me/2014/03/services-microservices-nanoservices/

<comment><USER2> I don't like the implication that this is a fad or that certain serialization formats are "hot".

If you're dealing with large data volumes, serialization can be the difference between a job that costs $500 to run vs. one that costs $200. If you're concerned about the user experience (i.e you are github, not Altassian) then you know that latency matters, and microserver architecture, properly done, can get latency way down.

The key thing about a microserver isn't a low line count it is the use of specialized data structures and algorithms that handle workloads with high efficiency.

For instance I have a system that uses MySQL. I found the latency of typeahead and fulltext search was way too high so I set up a Cleo server for typeahead and an ElasticSearch server for fulltext. These are so efficient that the hardware requirements are tiny.

Now I can live with the latency, but the running costs are more than I like. What can I do? There's one particular query that runs really slow, and if I replicate that data into a special database (even a MySQL with the bloat taken out of it) I can use a cheap machine to run the hard query and then use a cheap machine to host the rest of the MySQL.</comment>


Why Doesn't the World Care About Pakistanis? Because they live in Pakistan. - <AUTHOR> http://www.foreignpolicy.com/articles/2010/08/19/why_doesnt_the_world_care_about_pakistanis

<comment><USER2> The articles says this is a bigger disaster than the 2004 tsunami, the 2005 Pakistan earthquake, and the 2010 Haiti earthquake combined.

Maybe in area or property damage it is bigger, but in deaths the floods are around 2000. The earthquakes were each in the 80-100 range, and the tsunami 230k. I would guess that has a lot to do with it.

<comment><USER3> Indeed. I found the premise of the article to be wanting for the same reason. I mean, what's the more complex explanation: We don't treat the Pakistani floods on an equal measure with other disasters because we (the international community) dislike Pakistan? Or is it that the Pakistani disaster just hasn't had as much reporting and coverage?

I was in India as of a week ago. Even there, where Pakistan is both mentally and physically closer, the floods were barely getting any coverage at all. The news was dominated by a corruption scandal in the Organizing Committee for the Commonwealth Games. If the floods can't get coverage in India, what makes you think that they'd get anything other a single paragraph buried deep in the newspaper here?</comment></comment>


How Do You Hire People Smarter Than You? - <AUTHOR> http://founderdating.com/hiresmarterthanyou/

<comment><USER2> My dad taught me that delegation is about trusting that the work will be done better than if I had done it myself. Not always because of the lack of skill, but sometimes because of the lack of time. Hiring out of frustration due to pack of time can lead to poor choices, and a difficultly in working with the new hire

</comment><comment><USER3> It's great to see this topic being discussed. I've often wondered what it really meant to hire people smarter then you and then how to manage them - great insights here.</comment>


How Comcast became a toll-collecting, nuke-wielding hydra - <AUTHOR> http://arstechnica.com/tech-policy/news/2010/11/how-comcast-became-a-toll-collecting-hydra-with-a-nuke.ars <comment><USER2> Terrific analysis. This bit summarizes much of the article:

> Level 3 thought it was entirely fair—in part because this is not traffic > that is transiting _through_ Comcast's network, but traffic that is headed > for Comcast subscribers and was _requested_ by them. Under this view, > Comcast is trying to charge a content provider for the very access to > content that it is selling to its own customers. _</comment>


Show HN:Last year I asked HN to do it, now I am doing it myself-JournalClub iPad - <AUTHOR>

Almost one year ago I asked HN if anybody is interested to make a Web app to make reading and finding scientific papers smarter [http://news.ycombinator.com/item?id=1664648].
No one did, at least no one did what "I" think is the best way to approach this problem. A a few month ago I decided to do it myself.<p>Meet JournalClub iPad app (absolutely free), http://itunes.apple.com/us/app/journalclub/id443819334?
I have a recommendation engine in the pipeline that I would introduce in the next update (hopefully in a month or so).
I really appreciate any comments, feedbacks. <comment><USER2> I used to manage mobile products for a large STM publisher. This app is nice - well done getting it off the ground! FWIW I'd stay focused on the core concept (scanning many papers quickly), this is genuinely useful. Nail that first before moving on to other features. I wouldn't worry too much about recommendations: they're very hard to get right in this context, you'd be doing very well if more than one in twenty recommended papers were something useful that the user hasn't already seen.

</comment><comment><AUTHOR> Link to Apple app store:

<http://itunes.apple.com/us/app/journalclub/id443819334>?

</comment><comment><AUTHOR> Link to last year post:

<http://news.ycombinator.com/item?id=1664648>

</comment><comment><USER3> Isn't this what Mendeley does?

<comment><AUTHOR> Yep, they are also tackling the same problem. An to be honest I haven't used Mandeley in a while but their approach was not what I think is most suitable for me. To me, the main problem is not document management or reference management or ways of finding fulltext papers (these are all important but not the major problem). The major problem in my mind is exploration, which means keeping up to date with the literature, when despite using all the tools I still need to go through hundreds af papers a week to make sure I am not missing something relevant to me, I say my tools are not effective.</comment></comment>


How Camus and Sartre split up over the question of how to be free - <AUTHOR> https://aeon.co/ideas/how-camus-and-sartre-split-up-over-the-question-of-how-to-be-free <comment><USER2> I always thought the real intellectual differences related to Marxism were between Merleau-Ponty and Sartre, the former having introduced Sartre to Marxism and later publicly breaking with him for his "ultra-bolshevism." Camus and Sartre seemed to have more personal differences, viz., Sartre generally being an asshole. Among other things, he considered Camus a notch beneath him intellectually, and Ive always personally believed that a big reason Sartre turned down the Nobel prize was because Camus already had one.

Ive always struggled to understand Sartre's popularity even among other philosophers I respect.

<comment><USER3> > Ive always struggled to understand Sartre's popularity even among other > philosophers I respect.

I agree completely.

It is completely rankling when considering how he is compared to Simone de Beauvoir. Her "Second Sex" is considered a feminist work—and for good reason—but it surpasses any of what Sarte wrote as a philosophical work. While he did build on the backs of others, his ideas remain small compared to his contemporaries.

</comment></comment><comment><USER4> > _Sartre remained unpredictable, however, and was engaged in a long, bizarre > dalliance with hardline Maoism when he died in 1980._

Bizarre in what way exactly? At the time (late-60s to late-70s) in France maoism was as popular between students and scholars as Marvel movies are in the US today...

</comment><comment><USER5> It's worth noting Sartre spent 9 months as a POW, that influenced his outlook on freedom a fair bit.

</comment><comment><USER6> what are the public academic debates that we are having today? creationism vs evolution? populism vs neo-liberalism?

I hate to reminisce but having two existentialist philosophers debating about socialism vs communism makes me jelly.

<comment><USER7> You have to remember that these were two French intellectuals, debating in a country, culture, and time period where Socialism vs Communism was very much a live issue.

That's not really true in the United States today, where even Socialism is generally held in contempt, and Communism is considered to be a demonstratably failed ideology which doesn't even deserve to be taken seriously.

On top of this, intellectualism itself is viewed with great suspicion by many Americans, who much prefer to hear celebrity gossip, or watch sports and reality shows. As a result, the "public" intellectual debates of the era are dumbed down and infotainmentized by a media mostly concerned with ratings and pandering to the lowest common denominator.

There still are plenty of debates in academia in the United States today, but they're not very public, and mostly take place in academic journals which most of the public would rather die before reading.

I've heard that France is still a culture that greatly respects their intellectuals, so I would expect they still have many public intellectual debates these days. Maybe someone who keeps current with them could comment.

<comment><USER8> I agree with everything you said. But I'd suggest that not only are the debates in academia alive, they're actually too vigorous and too radical.

I think one of the contributors to the current political situation is the increasing influence of academia on politics and the law. Instead of having a few big ideas that we wrestle with, every politician and lawyer is a little Leninist bent on burning everything down in favor of their ever-changing pet political philosophies. And the notion of moderation has somehow become radicalized, I think; a dirty word for some people and a rallying cry for others.

The vigorous creativity of scholarship provides an endless supply of fodder in terms of new ideas, new reasoning, new justifications, and most recently new "facts". If we were a nation of philosophers it'd be some kind of paradise. But we're not, and it's ripping apart our core social institutions.

I'm not dissing the scholarship, or trying to suggest it's all bunk. I mean, even bunk can be valuable by challenging assumptions or by making conspicuous assumptions itself. But too much of that debate is bleeding out into the culture. A whole new layer of public policy institutions and media outlets feeds off and disseminates the half-baked ideas. There's never any time or energy to winnow the chaff. And so it's effectively poisoning the social and political culture.

<comment><USER9> >"A whole new layer of public policy institutions and media outlets feeds off and disseminates the half-baked ideas. There's never any time or energy to winnow the chaff. And so it's effectively poisoning the social and political culture."

Can you name one cultural meme that's emerged from academia in the last 10 years? I certainly can't. I simply don't think academic debates have that great a cultural impact in our modern society, regardless of this increased vigor you're referring to.

On the other hand, I can think of recent cultural memes that have emerged from the political sphere, pushed by a diverse range of people (from corporate interests to grass roots activists). Very few politically active people seem to be waiting around for answers from academia, they've got their own agendas to push.

<comment><USER10> Cultural memes aren't really the measure of progress, or worth, of academia. And "academia" itself is a pretty broad term: are you referring to Philosophy, or the Social Sciences or what?

<comment><USER9> >"Cultural memes aren't really the measure of progress, or worth, of academia."

I didn't say they were a measure of the worth of academia. However, they are a way to track the evolution of public debate. For example, the '1%' meme (about the top 1% owning more than the remaining 99%) has shaped public debate around wealth inequality. If academia has been a big influence on public debate, my argument is that we should see this play out in cultural memes. Cultural memes are just ideas which are commonly known in our shared culture. The GP indicated that the restlessness of academia was damaging public debate, my argument was that the general public was largely indifferent to this activity.

</comment></comment></comment></comment></comment></comment><comment><USER11> I think Camus knew that there were things that he didn't know about political economy while Sartre was more certain that the vast oversimplification of reality that is marxist economics could somehow be hammered somehow into the mold of reality. The problem of economic calculation is deceptively easy to hand-wave away.

<comment><USER4> The problem with the communists wasn't the "oversimplification of marxist economics", after all capitalist policies are based on similar oversimplifications. It was the power struggles, and the controlling party elites.

<comment><USER12> Other than human nature, it had everything going for it.

<comment><USER11> The subtler arguments against socialism are not amenable to sound bites. The one that was initially penned in the 1920s and has stood the test of time the best is "Economic Calculation in the Socialist Commonwealth"[1]. This kicked off the Socialist calculation debate[2] which was on-going during the 20th century. It was largely settled in favor of the anti-central planners with the collapse of communism and Deng Xiaoping's economic reforms in China.

[1][https://mises.org/library/economic-calculation-socialist- com...](https://mises.org/library/economic-calculation-socialist- commonwealth/html)

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

<comment><USER8> It really all comes down to pricing theory, right? Marxism says that labor has intrinsic economic value. That's fundamental to Marxist communist thought, from economics to social theory to theories of history.

Liberal economic theory says that there's no such thing as intrinsic economic value. See Diamond Fallacy. Optimal price signaling through a free market would be a necessary corollary. (And I think the Halting Problem could be used to prove that.)

Neither seem right to me, but Marxism definitely seems far more wrong. Nonetheless, concepts like dignity and justice wouldn't exist if labor and other activities didn't have some kind of intrinsic value, however indefinite or indeterminable. The vast majority of people in capitalist societies, especially those in ultra capitalist societies, and particularly Americans, believe in an intrinsic worth to labor. And human concepts such as dignity, justice, and "the value of human life" exist precisely to define what we perceive as intrinsic value. And perhaps that's what democracy is about--a hack bolted onto free market capitalism to aggregate (in a very poor manner) our normative assessments of different kinds of intrinsic values, and to pay those costs more optimally than capitalism alone could manage.

<comment><USER11> The truth is is that all labor is of equal COST, that being one hour of a person's time, but all labor is not of equal VALUE. Someone building a machine to do something is more valuable then the equivalent time spent doing the task by hand for example. The calculation of whether the machine should be built and then what it should be used for, especially if its function is very non- specific, such as a lathe, is where socialism gets messy and capitalism does better.

<comment><USER12> Touch of ableism here.

</comment></comment></comment></comment></comment></comment></comment><comment><USER13> Oh, not this again. Moderation improves only wrong ideas. Yes, experiments with social order are costly, but it absolutely doesn't mean that "even the most venerable and worthy ideas need to be balanced against one another".

</comment><comment><USER14> Freedom is an awful word (to use in rigorous discourse) because it simultaneously means two very different, if not in some way opposite things. Freedom can be used in the sense of having many options to execute your will, or it can be used in the sense of having nothing to lose by executing your will[0].

[0] - [http://www.azlyrics.com/lyrics/kriskristofferson/meandbobbym...](http://www.azlyrics.com/lyrics/kriskristofferson/meandbobbymcgee.html)

<comment><USER15> That's easily remedied by defining what's meant by freedom, which was a major part of the existentialist project.

</comment></comment><comment><USER16> So Camus against violence and Sartre for.

Makes sense; the philosopher or revolutionary most in favour of violence comes from the middle or upper classes, not the lower.

<comment><USER16> Rereading my comment I see it can be interpreted different ways.

So to clarify I was thinking of middle-class advocates of radical left wing causes - such as Che Guevera.

</comment></comment><comment><USER17> Those guys were writers, not philosophers in the first place.

Unlimited, pure freedom does not exist and hence the absolute Free Will. It is an empty concept. Freedom is bound by the mind, the mind is bound by biology. Biology is bound by physics and other constraints of the environment. The Universe of Ideas is mere a hallucination. Suicide as an ultimate act of freedom, which is the canonical illustration - the only freedom man have. Not much freedom, after all.

<comment><USER5> Camus said the only freedom is suicide. (The Myth of Sisyphus)

<comment><USER8> I agree with the others. The way I like to put it is that the only true freedom is in the _choice_ of suicide. The corollary is that to find any meaning in life you have to first come to terms with that grim reality. If and how you come to terms with that reality shapes the meaning of your life.

You can, of course, choose suicide. But then it's lights-out and so there's not much to discuss in that case. I don't think either Sartre or Camus saw suicide as cowardly, but maybe I'm wrong about that. As far as I see it, perceiving suicide as cowardly is sort of at odds with existentialist claim. If suicide is cowardly then suicide isn't much of a choice at all and then there really isn't any freedom at all.

(Of course, being animals with an intrinsic evolutionary predisposition to avoid death, suicide isn't much of a choice at all. Unless you're mentally ill, it's _really_ difficult to convince yourself to die. The lack of freedom in this world is actually much more grim than even existentialists wish to admit. But I'm happy to adopt the existentialist conceit as I think existentialism says something profound and profoundly concise about how to find meaning in life.)

<comment><USER9> >"If suicide is cowardly then suicide isn't much of a choice at all and then there really isn't any freedom at all."

A cowardly choice is still a choice, it's still a possibility. Freedom is freedom to choose, it imposes no limits on what motivates you.

Aside from this, cowardly doesn't seem to fit suicide, if we're going for negative connotations then self-absorbed seems more appropriate IMO.

>"The lack of freedom in this world is actually much more grim than even existentialists wish to admit."

What do you mean by this? What freedom do you feel you lack?

<comment><USER8> One freedom I lack is the freedom from the limitations of my brain, limitations which I can barely even fathom.

But the limitation I was specifically referring too was that suicide isn't like other personal choices because your body and mind act in concert against self-agency. And thank goodness that they do, but the point is that like infants we're trapped in an environment that is constitutionally hostile to any capacity for killing ourselves.

I do agree that a cowardly choice is still a choice, and that existentialism doesn't preclude seeing suicide as cowardly. But what does cowardly mean? Why might it be relevant to questions of freedom? And if relevant, how? Those are big question that hint at 1) another aspect to our rationality and self- agency, namely how they're culturally informed and intertwined with considerations of others' opinions, desires, and needs; and more generally 2) that a definition of freedom implicates other questions about the source and function of morality wrt rationality and agency.

I don't think existentialism is particularly concerned with those questions. They're not really within it's ambit. Camus and Sartre had different, even contradictory, moral philosophies even though both were authentically existentialist.

<comment><USER9> >"One freedom I lack is the freedom from the limitations of my brain, limitations which I can barely even fathom."

Okay, let's play along with this. If you feel your brain is holding you back, you must have an idea of what it's holding you back from, otherwise you wouldn't see it as limiting. In other words, it's only limiting in comparison with another way of being.

With this in mind, if your consciousness could expand beyond your brain, what would you hope to experience? What knowledge or experience would you hope to gain?

<comment><USER8> I don't know. Perhaps it's not a relevant limitation, or perhaps it's not a limitation relevant to the notion or my experience of freedom. Or perhaps it's a limitation that channels choice and thus enhances or even defines freedom.

What I do know is that I'm tired and stressed this afternoon and can't even _think_ about that question... ;)</comment></comment></comment></comment></comment></comment></comment>


How I became one of the three "best optimizers in the world" - <AUTHOR> http://iangent.blogspot.co.uk/2013/09/how-i-became-one-of-three-best.html <comment><AUTHOR> Interesting plot of the rank of this item:

[http://hnrankings.info/6429640/](http://hnrankings.info/6429640/)

It seems clear it's been flagged, but I have no idea why, and would appreciate it if someone could enlighten me. I'd've thought this was of interest to programmers, but clearly some people think otherwise, and I'd love the opportunity to learn why some people think it's inappropriate for HN.

Thanks in advance!

</comment><comment><USER2> What is constraint model programming?

<comment><USER3> [https://en.wikipedia.org/wiki/Constraint_programming](https://en.wikipedia.org/wiki/Constraint_programming)

Basically instead of specifying an algorithm you specify the constraints on the variables of the problem and then a generic solving algorithm finds solutions that match your constraints. It's a common solution for some types of problems where it's natural to think in terms of the constraints of the problem. For example to do the schedules for a school with 6 disciplines taught to 7 classes you might think in terms of constraints like:

1) There are 5 classrooms and no room can have 2 classes at once

2) The same discipline can't be taught at the same time to two classes (we only have one professor for each)

3) All classes must have 2h of each discipline

4) Classes must start after 9am and end before 6pm

Instead of designing a data structure and an algorithm to try permutations until you have a working schedule you would define your output variables and then specify these constraints as functions of those variables. In this case the variables would probably be 6*7 tuples of start time and classroom. Then you'd specify the 4 restrictions on those variables. You'd also probably have some kind of optimization function to try and not just get "a" solution but get a good solution (e.g., reduce the number of gaps in the schedule of each class).

Once you've specified both the constraints and the optimization function the generic solving algorithm does the heavy lifting and spits out solutions, sometimes even optimal solutions.

<comment><USER2> Interesting! Guess I should have checked Wikipedia. Would a logic grid puzzle be solved via constraint programming?

<comment><USER3> Sure, sudoku would be a good textbook example for the technique. The scheduling problem is just less artificial and one I know gets real world usage.</comment></comment></comment></comment>


Navy wants to post trucks with electromagnetic radiation equipment on West End - o0-0o http://www.peninsuladailynews.com/article/20140927/news/309279992/for-war-games-next-year-navy-wants-to-post-trucks-with

<comment><AUTHOR> This is an unbelievably incoherent newspaper story. It doesn't say what the "electromagnetic radiation" is, what frequencies, power levels, beam patterns, or purpose. It reads like a press release by someone who hasn't visited Earth yet.

Quote: "Extended close exposure to electromagnetic radiation could be a health hazard."

Yes, and (1) sitting outside too long can get you sunburned (sunlight is electromagnetic radiation), and (2) defeating the safety interlocks on a microwave oven is a very bad idea. Which degree of threat is the reporter telling us about?

<comment><USER2> It's not the reporter's fault. I don't think any of the official documents discuss what kind of radiation is involved. [http://data.ecosystem- management.org/nepaweb/nepa_project_ex...](http://data.ecosystem- management.org/nepaweb/nepa_project_exp.php?project=42759) The only information I could find is "(3) the beam pattern emitted is directional, which minimizes the area exposed to radiation". [http://a123.g.akamai.net/7/123/11558/abc123/forestservic.dow...](http://a123.g.akamai.net/7/123/11558/abc123/forestservic.download.akamai.com/11558/www/nepa/97011_FSPLT3_2242043.pdf)

<comment><AUTHOR> > It's not the reporter's fault.

Of course it is. Reporters aren't supposed to simply reprint the content of press releases as in this case, they're supposed to dig up some facts, something not covered by self-serving public relations documents.

> The only information I could find is "(3) the beam pattern emitted is > directional, which minimizes the area exposed to radiation".

Yes, and that's true for sunlight also. It's just not at all informative. If anyone cared to, they could visit the Navy public relations office and ask a few pointed questions. Most likely, the Navy would say it's a relatively high- powered microwave transmitter, with a beam directed upwards to the intended target (fighter jets overhead), with about the power of a microwave oven with the door open.

I'm not saying they would give that exact reply, but it would be likely to resemble it. But for that to happen, a real journalist would have to be on the job.</comment></comment></comment>


A Real Gatekeeper - <AUTHOR> https://bitsplitting.org/2019/07/22/a-real-gatekeeper/ <comment><USER2> > _Finally, in 2019, Apple announced that software signed with Developer ID > certificates, that is to say all non-Mac App Store software, must also be > notarized. The Catalina 10.15 public beta identifies software that has not > been notarized as potentially risky because it "cannot be scanned for > malware."_

> _In effect: developers who ship software directly to end-users are now > required to notarize their apps._

People keep spreading this rumor, and it's just not true. You can distribute unsigned apps to users; most open-source Mac apps do it this way.

When users try to open an unsigned app, macOS pops up a "denied" message. People who know how to run unsigned apps can right-click and Open the app to run it, or go to the Security panel in System Preferences.

Getting out of "warning mode" previously required Developer ID, and now it requires notarization, too. But warning mode still works, so it's not required, nor is it "effectively required."

</comment><comment><USER3> Is it fair to say the reasoning Apple would present in favour of having an "App Store" is that Apple can act as an _exclusive_ gatekeeper for quality control and "security". Are there other reasons?

Through the App Store, Apple attempts to exert control over the software that an Apple hardware purchaser can run. Are the business advantages to Apple of this arrangement incidental or coincidental?

<comment><USER4> It's for quality control and security _and_ it's good business. When they decided to do this in 2008 they couldn't have known how big the App Store (and the iPhone) was going to get. You can listen to an interview a WSJ reporter did with Steve Jobs about it. No one at Apple actually knew, including Jobs.

[https://www.wsj.com/articles/the-mobile-industrys-never- seen...](https://www.wsj.com/articles/the-mobile-industrys-never-seen- anything-like-this-an-interview-with-steve-jobs-at-the-app-stores- launch-1532527201)

> MR. WINGFIELD: What does that number say to you?

MR. JOBS: It says the App Store is much larger than we ever imagined, iTunes has been out for over five years. In 30 days, users downloaded 30% as many apps as everybody in the world downloaded songs from iTunes.

MR. WINGFIELD: What did you expect? What was your internal...

[crosstalk]

MR. JOBS: We didn't expect it to be this big. The mobile industry's never seen anything like this. To be honest, neither has the computer industry. [laughs] 60 million downloaded applications in the first 30 days. 30% as big as iTunes song downloads during the last 30 days, this is off the charts.

MR. WINGFIELD: OK. The 70-30 split, are the economics of this working out the way that you had said when we last spoke, which is that you might make some money, but you don't expect it to be a big source of profits?

MR. JOBS: Yeah. It's just like iTunes.

MR. WINGFIELD: Even with the huge popularity of this, you don't...

MR. JOBS: No. It costs money to run it. Those free apps cost money to store and to deliver wirelessly. The paid apps cost money, too. They have to pay for some of the free apps. We don't expect this to be a big profit generator. We expect it to add value to the iPhone. We'll sell more iPhones because of it.

MR. WINGFIELD: Every time I write about the amount of developer support that you have on iPhone, I hear from a bunch of other people who have been doing BREW applications for years. People say, "No, this is nothing new. There is a whole ecosystem around Windows Mobile, around Java, BREW, for other types of phones." How do you think these apps compare to those?

MR. JOBS: Two or three things. No. 1, if you talk to developers that are developing for the iPhone, what you'll hear from them unanimously is two things. There's never been a mobile platform that's been this powerful before.

As an example, when we were working with some of the first developers under the radar before we launched, they first sent their mobile teams here. When they realized how powerful the platform was, they sent their desktop teams here or their console teams here.

They realized that the quality of the graphics, the animation, the processing and the memory really made this much more capable as a platform than any other mobile platforms. We're hearing that from every developer. You heard [videogame designer John] Carmack's comments, right?

MR. WINGFIELD: Mm hmm.

MR. JOBS: The second thing we're hearing is that the development environment is far more advanced than they had ever seen on a mobile platform before. The APIs are in another league, the whole development cycle, the debug tools, etc. That's just to develop the app.

Once your app is developed, to be able to submit it to Apple and have us take care of all of the marketing, wireless distribution, billing and all the transactional stuff for you, and deliver it right on the handset, that doesn't exist today. There are some websites that will do some of that for you. They don't deliver it to the phone.

MR. WINGFIELD: They go and...

[crosstalk]

MR. JOBS: Yeah, they'll deliver it to your PC. You can sideload it, this and that. They charge a lot more than we do for doing a fraction of what we do.

MR. WINGFIELD: Do you know what the revenue split is on these other sites?

MR. JOBS: The minimum is 50-50. Generally, it can go into the 70% or more.

MR .WINGFIELD: On the other side of the equation, 70 to the distributor and 30 to the developer?

MR. JOBS: Yes. It's at least 50. We've heard it goes up to 70. They do a lot less than we do. They don't get it in front of every user. You have to go to a website. You have to buy it on your PC, blah blah blah.</comment></comment>


Tale of the trench: what if your subdivision laid its own fiber? - <AUTHOR> http://arstechnica.com/tech-policy/news/2011/01/what-if-your-subdivision-laid-its-own-fiber-network.ars <comment><USER2> I think this is exactly the situation that would have evolved if government did not support monopolies.

There are economies of scale for utilities and there are economies of corruption and waste for government. Without coercion, we'd have neighborhood ownership of the last mile and multiple entities competing to connect them.</comment>


How Urban Anonymity Disappears When All Data Is Tracked - <AUTHOR> http://bits.blogs.nytimes.com/2014/04/19/how-urban-anonymity-disappears-when-all-data-is-tracked/?_php=true&_type=blogs&hpw&rref=technology&_r=0

<comment><USER2> _"We can have so much fun with this," the co-founder of LocoMobi, Barney Pell, who is also its chairman, said. "Imagine knowing that people who park here also park there – you've found the nearby stores, their affinities. You could advertise to them, offer personalized services, provide 'passive loyalty' points that welcome them back to an area."_

Even if you're 100% ethically OK with this for a business to do, that's a really fucked up definition of fun.</comment>