Why is Maxwell's theory so hard to understand? (2007) [pdf] - <AUTHOR> http://www.damtp.cam.ac.uk/user/tong/em/dyson.pdf <comment><USER3> It is unfortunate that Dyson neglects the role of Oliver Heaviside, again. This is in a long tradition of English neglect, ultimately traceable to Heaviside's status as a commoner. Heaviside invented the mathematical tools we still use to understand and teach Maxwell, and most of the important consequences of the theory, but Pupin, Hertz, Marconi, and deForest used his methods and <del>took</del> got the credit.

Today Heaviside's method is taught as Laplace transforms, with Heaviside's name scrubbed off. We only hear of him as an alternative name for the step function, the integral of the Dirac impulse function, and of the "Heaviside layer", the ionosphere that makes transcontinental radio actually possible, but we would have waited decades longer without him.

An excellent reference for the importance of Heaviside in the ultimate success of application if Maxwell's theory is Paul J. Nahin, "Oliver Heaviside: The Life, Work, and Times of an Electrical Genius of the Victorian Age", [https://www.amazon.com/Oliver-Heaviside-Electrical-Genius- Vi...](https://www.amazon.com/Oliver-Heaviside-Electrical-Genius- Victorian/dp/0801869099/ref=mp_s_a_1_1?ie=UTF8&qid=1546801611&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=nahin+heaviside)

<comment><USER4> Exactly, one of the main reasons why maxwell is so hard to understand is that everything is expressed using quarternions unlike Heaviside who expressed the equations using the vector notation we see them expressed in today. In reality 'Maxwell's' equations are in fact Heaviside's.

<comment><USER5> Arguably the reason that generations of STEM students have been horribly confused about 3-dimensional vectors and rotations (including electric/magnetic fields), etc. is that they were reframed in the confused and non-generalizable Gibbs/Heaviside language, instead of in Grassmann/Clifford's formalism in which vectors and bivectors can be properly described as separate types of objects.

It can be so much nicer. [http://geocalc.clas.asu.edu/pdf/OerstedMedalLecture.pdf](http://geocalc.clas.asu.edu/pdf/OerstedMedalLecture.pdf)

<comment><USER6> Reminds me, I've been meaning to read this [0] blog post for a while now. (See also the HN discussion [1].) My clueless intuition tells me its points may be analogous to your linked document. (It mentions Heaviside, at least.)

[0] [https://www.gamedev.net/articles/programming/math-and- physic...](https://www.gamedev.net/articles/programming/math-and-physics/do- we-really-need-quaternions-r1199/)

[1] [https://news.ycombinator.com/item?id=18365433](https://news.ycombinator.com/item?id=18365433)

<comment><USER5> Perhaps start with [https://www.shapeoperator.com/2016/12/12/sunset- geometry/](https://www.shapeoperator.com/2016/12/12/sunset-geometry/) for a concrete example.

<comment><USER6> Looks good, thanks.

</comment></comment></comment></comment></comment></comment><comment><USER7> E&M is far from "simple". It contains special relativity, for starters. Also it is incompatible with thermodynamics: solving this problem is why Planck invented quantum mechanics. Also point charges have infinite energy: this problem leads to renormalization theory. Also it introduces gauge invariance, an essential but complex part of all modern theories. And lastly, the mathematics of E&M is a big step up from Newtonian theory.

<comment><USER8> >"E&M is far from "simple". It contains special relativity, for starters."

A theory (which is just a set of assumed first principles and rules of logic) can be simple but allow you to deduce vast complexity from it. In fact, it is ideal for a theory to be as simple as possible.

The "game of life" is not really a theory, but it demonstrates that simple rules can lead to surprising complexity: [https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life](https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life)

EDIT:

I can't begin to imagine why this would trigger a downvote. Are there people out there who prefer complex theories that make things more difficult to understand than necessary? Perhaps because it makes them feel smart or something, I don't know.

But that is basically saying you dislike science, because the point of science is to synthesize information into a small set of simple "laws" that allow us to deduce accurate and precise predictions.

<comment><USER9> I reflexively downvote the game of life. I have never heard of a single useful application or analogy of "finite automata." Yes, there are speculations about extremely small Planck lengths, by no new physics has panned out. Finally I am sad that one of the greatest computer scientists and polymaths, Ed Fredkin, got sucked into this. We all have weaknesses.

<comment><USER10> Surely you mean cellular automata, not finite automata.

<comment><USER9> Yes, you are right. My ignorance shows, but I am still hanging on to my opinion of cellular automata.

</comment></comment></comment></comment></comment><comment><USER11> I am struck by the clarity and simplicity of Dyson's writing.

As to the substance: yes, hiding your work under a bushel does nobody any favor, but it's understandable when it feels like the alternative is the strident trumpeting of trivial "advancements".

But also cautionary is the constraints due to the wrong metaphors. We often see this today in linear predictions as to the impact of some new idea. It's easy to mock Ballmer when he laughed at the iphone back in 2007 (back when this essay was written). But his comment made sense _for his customer base_. He (and nor could Apple) couldn't really see that the game was changing.

Dyson points out that Maxwell himself had the same problem.

<comment><USER12> Why would you say Apple, whose main business was an extensive traxk record in creating, promoting, and selling next generation technology, that their major investment in a new field was blind speculation?

In contrast to Microsoft whose business was providing stable solutions and extracting monopoly rents.

<comment><USER11> Not sure I understand your point. Mine was that in science or business we are often held back from understanding by the limitations of our models, even when we ourselves are the inventors.

I thought I used an example well known to HN to make the point. Apple's stated hope was to eventually have 1% of the market (and they didn't originally plan for an App Store). Like Maxwell, _they_ didn't know they had a blockbuster.

Microsoft listened very closely to their customers, who were and are mainly corporate I/T and something like the iphone wasn't something they said they wanted. In fact it honestly had no affordances that IT wanted.

Maxwell understood the math but his own mechanical metaphor distracted him, and other physicists too, so that they couldn't really see the larger implications.

<comment><USER13> _an example well known to HN_

I think the issue is that example doesn't seem to be true.. Jobs said at the time of launch that it was a revolutionary and magical product which was five years ahead of everyone else and would change everything. And the hope wasn't to have 1% eventually, but by the end of 2008.

</comment></comment></comment></comment><comment><USER14> Interesting. And makes me wonder what else we are missing and misunderstanding, as we waste so much time trying to express the complexity of the world in spoken language rather than math. Not just physics but in sociology, psychology, economics etc.

Faraday purely from experiments 30-40 years before Maxwell, intuitively understood electromagnetism. Nobody serious believed it because he didn't have the training to express it mathematically. Dyson is saying it took Physicists another 20-30 years post Maxwell to get it. So basically ~70 years wasted.

<comment><USER15> Spoken language has a lot going for it. I note the featured article and it's discussion are all words not maths.

By the way looking at Maxwell's paper it seems awful complicated [https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1865...](https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1865.0008)

compared to the modern form of the equations [https://ethw.org/w/images/d/d6/Maxwell_image_02.jpg](https://ethw.org/w/images/d/d6/Maxwell_image_02.jpg)

<comment><USER3> The modern form of the equations was worked out by commoners, so had to be filtered through the work of others before it could be taught.

<comment><USER16> You're really caught up on this commoner/non-commoner dynamic (from your other comments). Was it really that important? - many of the well known scientists of that time were 'commoners'.

<comment><USER3> I'm not, but they were. But it was not discussed openly in print at the time, and so must be inferred.

<comment><USER15> I just read his Wikipedia and he was sponsored by his uncle Sir Charles Wheatstone of Wheatstone bridge fame and ended up a Fellow of the Royal Society so was not so badly situated.

</comment></comment></comment></comment></comment></comment><comment><USER17> It's not until now, over 20 years later, that I realize what a magician my E&M prof was. After months of careful development of basic E&M, Maxwell's equations simply fell out. As I recall, it was capacitance that was the impetus. It was as though we had struggled in a dark tunnel for months and suddenly came around a turn and there was light. Not a little, but sheets of daylight and all the equations just fell together, one from the next. All the equations revealed themselves from the middle of one lecture to the middle of the next lecture.

And then, in E&M 2, with a different professor, I spent the entire semester coming to grips with the fact that the implications of these formulas would challenge my grasp on reality for the rest of my life.

<comment><USER18> In what ways were they that important later in life?

<comment><USER17> Because my undergrad is in physics and I'm still in science, E&M opportunities are evident to me, but I know I would struggle to really go after them myself. So I get help, but I sure wish I could do it on my own.

</comment></comment></comment><comment><USER19> Some people hold the view that a better way of teaching electromagnetism is through geometric algebra. See: [https://arxiv.org/abs/1010.4947](https://arxiv.org/abs/1010.4947)

<comment><USER20> Also, the approach based on differential forms is very appealing; for a list of various formulations of electromagnetism, see [https://en.m.wikipedia.org/wiki/Mathematical_descriptions_of...](https://en.m.wikipedia.org/wiki/Mathematical_descriptions_of_the_electromagnetic_field)

<comment><USER21> Aren't the two very closely related, if not equivalent? Differential forms and Geometric Algebra I mean.

<comment><USER22> Yes, they operate on the same objects. The main operations on differential forms are the exterior derivative d and the wedge product f /\ g. These are independent of the metric. If you add a metric you get one extra operation called the Hodge star ⋆, which is a prefix operator, so it operates as ⋆f.

Alternatively, if you have a metric on your space you can define the geometric algebra derivative D and the geometric product. These are closely related to the differential forms operations, e.g. Df = df + ⋆d⋆f. Using it, Maxwell's equations become one equation, namely DF = J where F is the electromagnetic field tensor and J is the four current.

So in my opinion it's indeed best to not put this as differential forms vs geometric algebra, but rather as a single theory in which some operations don't depend on the metric (d, /\\) and some do (⋆, D, geometric product).

Unfortunately, geometric algebra has been overhyped by its proponents, and the papers they write are less than rigorous, so some people are under the impression that it's crackpottery, so it's safer to call it Clifford algebra :)

<comment><USER23> Is it possible to work with geometric algebra effectively without a metric using some more complicated construction?

<comment><USER5> Sure. What model to use depends on you are trying to model.

[http://geocalc.clas.asu.edu/pdf- preAdobe8/PGwithCA.pdf](http://geocalc.clas.asu.edu/pdf- preAdobe8/PGwithCA.pdf)

[http://geocalc.clas.asu.edu/pdf- preAdobe8/DLAandG.pdf](http://geocalc.clas.asu.edu/pdf-preAdobe8/DLAandG.pdf)

etc.

</comment></comment></comment></comment></comment></comment><comment><USER24> People didn't really get Maxwell because Maxwell's equations don't need a medium aka "aether".

Waves propagating without a medium is a shocking message in this time frame.

Maxwell published his equations in 1861/1862 in first form.

In 1887, the Michelson–Morley experiment gave the first experimental disproof of the "aether".

It also doesn't help that you have things like "displacement current" and have to find strange integration surfaces to make Maxwell's equations work out for things like capacitors or motors. (The Heaviside-Hertz pedagogy that everybody is _STILL_ taught is particularly problematic to use for motors.)

<comment><USER25> > In 1887, the Michelson–Morley experiment gave the first experimental > disproof of the "aether".

In what way is LIGO not a bigger, and successful, version of the Michelson- Morley experiment?

I'm honestly asking, because from my limited understanding, it seems to be.

From Wiki:

> This result is generally considered to be the first strong evidence against > the then-prevalent aether theory, and initiated a line of research that > eventually led to special relativity, which rules out a stationary aether.

It seems that LIGO merely confirmed properties of an existent aether, not that we no longer believe in one:

> Aether theories (also known as ether theories) in physics propose the > existence of a medium, the aether (also spelled ether, from the Greek word > (αἰθήρ), meaning "upper air" or "pure, fresh air"[1]), a space-filling > substance or field, thought to be necessary as a transmission medium for the > propagation of electromagnetic or gravitational forces.

Naively, spacetime and quantum fields are both forms of aether theories.

<comment><USER24> If LIGO confirmed "aether", then the measurements in the perpendicular arms would vary depending upon time (orientation of Earth in rotation, orientation of Earth around Sun, etc.).

As far as I know, they very much do _NOT_ vary--to an absolutely _amazing_ precision.

As far as I can tell, if the "aether" existed and we could detect it, we basically would have no hope of detecting gravitational waves.

> Naively, spacetime and quantum fields are both forms of aether theories.

Not ... really.

The existence of "aether" implies a preferential frame of reference. And every experiment we have done to attempt to establish such has failed.

<comment><USER25> But the arms are predicted to vary in those cases by the same theory that LIGO is confirming: our rotation causes frame dragging, and there's some weird Sun- Earth orbital relativistic effects as well, right?

I know the Sun-Jupiter orbit produces a large portion of the estimated 5,000 watts of gravitational emissions given off by our solar system. My mental model of this is that it perturbs the aether ("spacetime") through which it travels, radiating waves which carry energy out of the system. Is there a different one?

It's just the power output in those waves is incredibly, incredibly low -- LIGO can only hear much larger events, such as large astral bodies colliding.

So I'm not sure I understand -- there seems to be at least a gravitational aether.

<comment><USER26> By aether, do you mean an underlying medium that allows forces to be propagated? I guess that using that definition, there is an 'aether'.

The difference with the rejected concept of aether is that this "aether" is deformable by gravity, whereas the rejected one is not.

<comment><USER27> > underlying medium that allows forces to be propagated

General Relativity is a local theory concerned with the mechanisms that generate the metric, the geodesics implied by the metric, and the coupling of objects to those geodesics.

The relevant forces are those which accelerate objects into non-geodesic motion (or boost them from one geodesic to another). Those are local[1] as well: electromagnetism and the nuclear interactions. There's nothing like a luminiferous aether or underlying medium in the Standard Model, even if you look funnily at the gauge bosons -- they obey Lorentz covariance.

I made a couple of sibling comments to yours, one of which deals directly with your comment's parent's idea of a gravitational aether.

\- --

[1] RM Wald, _Quantum Field Theory on Curved Spacetime and Black Hole Thermodynamics_ (University of Chicago Press, 1994). Cf. the top of page 6 of Hollands & Wald 2014, [https://arxiv.org/abs/1401.2026](https://arxiv.org/abs/1401.2026)

<comment><USER25> Isn't every "field" in QFT basically an aether?

<comment><USER27> Please tell me what you mean by aether, as rigorously as you can, and then I can give you an answer to the question which seems to be bedevilling you.

Meanwhile I can guess at what you're asking:

The Standard Model ( _a_ QFT) has interacting quantum fields obeying purely local dynamics. The behaviour "here-and-now" depends on the field-values "here". It does not depend on field-values "now" but far from "here". Moreover, the Standard Model is Lorentz-invariant, meaning its laws hold in any inertial frame of reference, thus the scare quotes in the previous sentence.

The luminiferous aether that Michelson & Morley were looking to measure was motivated by finding a single special (and universal, or at least covering the whole solar system) inertial frame of reference in which Maxwell's equations hold exactly. No such frame exists; there is a huge democracy of inertial frames in which relativistic electrodynamics is exact in the classical limit. ( [https://en.wikipedia.org/wiki/Preferred_frame](https://en.wikipedia.org/wiki/Preferred_frame) )

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER28> Maxwell did not use vector calculus, which actually makes it pisser to understand because it bypasses having to convert the vectors to coordinates. I find short hand notion more confusing than writing it all out even if the latter takes more room. I did not understand general relativity at all until I saw an example where everything was written out and then it made much more sense

<comment><USER23> This is something of a myth. Maxwell actually uses _both_ to ease the mathematical pain for his readers - he writes the equations out coordinate by coordinate, and he also compresses them using Hamilton's (quaternion) model of vectors. In fact Maxwell was the one who introduced the gradient, curl, and divergence (actually he used convergence) operators, and he addressed precisely your concern in his book by giving both formulations!

<comment><USER29> Quaternions are not a "model of vectors."

Maxwell used per coordinate equations and quaternion equations, but never wrote out what are now known as "Maxwell's equations," which were first formulated by heaviside using Gibbs-Heaviside vector calculus.

Gibbs-Heaviside vector calculus formulations proved far more valuable to engineers and scientists than the equivalent quaternion formulations - <USER2> the criticisms from Hamilton and Tait.

<comment><USER30> > Quaternions are not a "model of vectors.

I dont think I agree. Yes they are not the Gibbsian vector but they are a pretty damn good model of what we want to model as vectors. Its already a little closer to geometric algebra / calculus than Gibbsian vectors. Its a pity that Grassman and Clifford's work gained attention much later.

Once javascript is out of the bag one cant do much about it. Thats how I feel about Gibbsian vector calculus and geometric algebra. Not that javascript or Gibbsian vectors are bad, quite the contrary, they are astonishing in their own right and scope, but one still feels they could have been so much better.

<comment><USER29> I think geometric algebra is a very cool and elegant approach as well, but it has not yet proved useful or valuable to working engineers.

If we want to compare to programming languages, perhaps Haskell vs. C. One is beautiful and elegant, the other is down to earth and conceptually simple for "normal" people. One is primarily used by academics and researchers, the other is used to build the world. Both are admirable.

<comment><USER30> > has not yet proved useful or valuable

They would have, had they been the "first mover". Hence my Javascript analogy

Had a better language been released at that time it would have been just as useful and valuable. In fact much more so. But as is usual, a "worse_is_better" first mover accrues so much head start in the mind share and in the tooling / literature that it becomes impractical to switch, especially when both can express the same set of things (just that one does it more concisely than the other). Another shallower example: imperial vs metric units.

I dont think its like Haskel::C at all. Haskell is way more mathy and has a steeper learning curve than C. One who can master curl divergence and vector stoke's theorem can master geometric algebra with less effort

</comment></comment></comment></comment></comment></comment><comment><USER31> I have a copy of Maxwell's two volumes on electromagnetism and what makes it difficult to read for me is that his "equations" are actually a long list of disparate equations that describe a unified theory. It's not a simple "answer" such as E=mc^2, it is a series of such descriptor answers.

Mathematically, it is easier for me to focus on one aspect and study that aspect's equations (at a time).

</comment><comment><USER32> "The phrase "Another theory of electricity which I prefer" seems deliberately intended to obscure the fact that this was his own theory."

To me, this just sounds like typical British understatement, which I'm sure the audience at the time would have understood.

</comment><comment><USER33> >We still have passionate arguments between believers in various interpretations of quantum mechanics, the Copenhagen interpretation, the many- worlds interpretation, the decoherence interpretation, the hidden-variables interpretation, and many others.

lukcily there has been slight progress since 2007 [https://www.quantamagazine.org/frauchiger-renner-paradox- cla...](https://www.quantamagazine.org/frauchiger-renner-paradox-clarifies- where-our-views-of-reality-go-wrong-20181203/)

<comment><USER34> It seems that this arguably new paradox has some issues: [https://www.scottaaronson.com/blog/?p=3975](https://www.scottaaronson.com/blog/?p=3975)

</comment></comment><comment><USER35> The theory is very easy to understand. Its the differential notation and manipulation of said notation that is challenging for people who dont math often

</comment><comment><USER9> Say what? Start with the integral representations of the equations a la Halliday and Resnick. You can do tons of useful problems. Once you understand vector calculus, you will understand the equations as written in differential form. Then, pick up a copy of Purcell to see how magnetism comes out of the Lorentz transformation of electrostatics. If you are mainly interested in applied problems, go through Corson and Lorraine. Finally: 1. Realize that the treatment of ferromagnetism is much too limited in most E&M texts. 2. Optics is also worthless in those books. It is a field unto itself, with theoretical, applied, and quantum parts all handled by different books. 3. You don't use Feynman's Lectures to learn anything the first time. You use them to see if you understand physics as well as Feynman (you don't.). All the problems have to have been done BEFORE this step.

<comment><USER36> You seem to be responding to the title, not the essay.

Dyson describes the theory as "simple and intelligible" once you accept the concept of fields, which was very much foreign in Maxwell's time.

<comment><USER9> You're right. I'm fairly embarrassed.</comment></comment></comment>


Kurt Vonnegut explains drama (2009) - <AUTHOR> https://sivers.org/drama <comment> andrey-p I read an article form of Kurt Vonnegut's original talk. My favourite part was the happiness/misery graph of The Metamorphosis: [http://austinkleon.com/wp- content/uploads/2005/vonnegut6.gif](http://austinkleon.com/wp- content/uploads/2005/vonnegut6.gif)

(Found here: [http://austinkleon.com/2005/12/17/graph-a-story-with-mr- vonn...](http://austinkleon.com/2005/12/17/graph-a-story-with-mr-vonnegut/))

</comment><comment><USER2> Here's a video of the man himself explaining it:

[https://www.youtube.com/watch?v=oP3c1h8v2ZQ](https://www.youtube.com/watch?v=oP3c1h8v2ZQ)

<comment><USER3> Thanks for the link. Interesting that the audience in this video found this all to be quite amusing; however he was talking serious stuff here; So was the laughter because of a misunderstanding because audience and speaker?

So maybe it doesn't quite sound so funny to me because in our age we are used to this kind of reasoning, and them back in the seventies weren't?

</comment></comment><comment><USER4> Alternative viewpoint: [https://www.youtube.com/watch?v=JHVqxD8PNq8](https://www.youtube.com/watch?v=JHVqxD8PNq8)

But, don't take the speech purely at face value -- Adaptation (the movie) leaves it ambiguous about whether this is wisdom, puffery, or accidentally true for the wrong reasons.

Also, it should be pointed out that Kurt Vonnegut had the kind of childhood that would probably leave anybody numb to the ups and downs of life, and also lived through the firebombing of a German city. Everything in his oeuvre is about how impotent human stories are, to prepare people for 20th-century scale horror. So take that as you will.

</comment><comment><USER5> The idea of a the significance of the sequential change in mood in a story reminds me of the "qualitative tempo trajectory" that underlies DJ sets (section 3.2):

[http://www.hpl.hp.com/techreports/2000/HPL-2000-104.pdf](http://www.hpl.hp.com/techreports/2000/HPL-2000-104.pdf)

</comment><comment><USER6> This hits home. You could basically sum up the problems with my college worldview with this talk.</comment>


Pelosi Sends Letter to FCC Chairman Urging Protections for Net Neutrality - <AUTHOR> http://www.democraticleader.gov/newsroom/pelosi-sends-letter-fcc-net-neutrality/

<comment><USER2> Key point is that it doesn't just call for "Protections for Net Neutrality", but that it specifically calls for Title II classification.

</comment><comment><AUTHOR> (Title changed a tiny bit to meet length requirements)</comment>


A Mansion, a Shell Company and Resentment in Bel Air - <AUTHOR> http://www.nytimes.com/2015/12/15/us/shell-company-bel-air-mansion.html <comment><AUTHOR> Already posted twice, without discussion, which is a bit odd as real estate investment by corrupt foreigner messing up with the market and excluding locals have been a hot topic here, albeit more about the bay area.

In any case it shows how a good corporate veil, for all purpose buys you immunity in the US.</comment>


Akon, AKoin, and the real-life Wakanda - <AUTHOR> https://www.iafrikan.com/2018/06/20/akon-is-looking-to-build-a-real-life-wakanda-powered-by-his-newly-announced-cryptocurrency/ <comment><USER2> 2,000 square meters would fit in a square 45 meters by 45 meters.

The actual gift appears to be 2000 sq Acres gifted from Senegalise President Macky Sall.</comment>


Patent on the NFC Mechanics of Apple Pay Details Its Inner Workings - <AUTHOR> http://techcrunch.com/2014/10/09/apple-patent-on-the-nfc-mechanics-of-apple-pay-details-its-inner-workings

<comment><USER2> It's worth noting that tokenization isn't an Apple thing - it's something the card networks came up with a year ago: [http://about.americanexpress.com/news/pr/2013/mc-visa- amex-p...](http://about.americanexpress.com/news/pr/2013/mc-visa-amex-propose- new-global-standard.aspx)

</comment><comment><USER3> What I don't get is how something like this could be patented. Isn't it all obvious? I think we had every single non-trivial component (single-use tokens passed over secure channels, initialize-send-retry_if_failed loops and other stuff) for years. If the "innovation" is that those are now used for payments over NFC — I don't get it. Or I've missed something novel on a quick glance.

<comment><USER4> You need to read the claims of the patent - it isn't patenting payments over NFC, it is on ways of recovering on NFC communications failures.

That still doesn't seem novel, but that is a different topic to argue than payment over NFC...

</comment></comment><comment><USER5> "That could be ideal for the forthcoming iPad, which is rumored to offer Touch ID and Apple Pay"

Can't wait to be in line behind the person fumbling to get our their iPad to pay for a pack of gum. Phone and watch should be smooth though.

<comment><USER6> From the way the rumor mill is churning it looks like the iPad won't have NFC, and so the Apple Pay functionality would be limited to In App purchases through Instacart, Groupon and such, rather than In Store purchases at Walgreens.

</comment></comment><comment><USER7> Here's a link to the patent: [http://1.usa.gov/1nelibZ](http://1.usa.gov/1nelibZ)

<comment><USER4> Claim 1, 8, and 15, on which the other claims are based, indicates the patent applies to how the system recovers from NFC failures, not the NFC payment mechanism itself. The other claims cover ways of diddling (mostly hardware) parameters to recover.

1\. A method of operating a portable electronic device, comprising: using the electronic device to conduct a mobile payment transaction at a merchant terminal; and _in response to detecting that the mobile payment transaction has failed,_ updating at least one operating setting on the electronic device prior to performing a subsequent payment attempt at the merchant terminal.

<comment><USER8> Did Apple just try to patent updating a variable and re-trying a request?

</comment></comment></comment><comment><USER9> original post: [http://appleinsider.com/articles/14/10/09/apple-outlines- app...](http://appleinsider.com/articles/14/10/09/apple-outlines-apple-pay- nfc-operation-in-comprehensive-patent-filing)

</comment><comment><USER10> Does this mean Apple Pay won't work with existing NFC payment terminals?

<comment><USER11> Nope. It will.

</comment></comment><comment><USER12> Patents need have little to nothing to do with products, and any article which claims that a patent disclosure reveals something unannounced about a product can be ignored without reading.

<comment><USER12> Yay, downvote!

What for? I continue to assert that articles that claim that patents reveal things about products are unfounded.

I have a number of patents myself: companies file them all the time with little to no concern for whether they'll use them in a product. Thus, the existence of a patent is little to no evidence regarding products.

<comment><AUTHOR> What you said about the relationship between products and patents is true and worth adding to the discussion, fwiw.

I think making it an absolute - ie, there is never anything to learn along these lines - is going too far, but there are certainly a lot of patents that never see further development.

<comment><USER12> It's a little bit of hyperbole, sure, but I don't recall ever seeing a press article that used a patent disclosure to offer any real insight about unreleased products. I'd be happy to see a counterexample.</comment></comment></comment></comment>


RiP A Remix Manifesto - Great documentary about remix culture and copyright.  - <AUTHOR> http://www.hulu.com/watch/88782/rip-a-remix-manifesto

<comment><USER2> "Remix culture" is really nothing new. A lot of traditional music worked this way: Someone would hear several melodies, then they'd use fragments of them to make a new one. Someone would take a melody from one song and write their own set of lyrics.

"Remix culture" is just how things have always worked. It's just that now, we have all this digital technology to leverage for it.

</comment><comment><USER3> This has been on Hulu for a while now, it's a great film to educate yourself on copyright law, particularly if you're a Girl Talk fan.</comment>


Tell HN: I've put together Startup Wiki - <AUTHOR>

Evening HN,
A while ago someone here reminded me about HNStartups.com - which is sadly full of spam.
As I had some spare time, was casting for a new project and have always wanted to turn my hand to building a wiki type site it seemed like a prime opportunity.
So here it is: http://www.startupwiki.co.uk
== Some Details ==
I took a slightly different approach to HNStartups. The first difference is it is not Ycombinator centric. I designed it so you could enter any name (be it a fund or individual), indeed a number of different names to detail where the funding has come from. That information is collated so you can click a link and see who else X is financing :)
The second difference is it is a wiki: this is so we don't lose any content to spam etc. If your logged in (please do create an account!) you can mark revisions or whole articles as "spam". If enough people mark it then options for deletion appear to certain people.
I also implemented a karma system; this was just a side effect of the fact I wanted to attempt to build something with a community moderation system. You get or lose Karma for site actions - and at certain levels some mod tools open up for you. Right now those limits are set extremely high. I'll tweak them down once the site gets active (if it proves popular).
It might only need some TLC to keep spam out; which I will happily give. But at least the fallback is reasonably well in place :)
The main aim is to do the same as HNStartups. Track startups and try to build up a reasonable amount of information about them that may be useful for future entrepreneurs.
== Now for the CAVEAT ==
Im launching it now because it has been semi-complete for a few months. There are lots of other bits I want to add but Im not sure I will get chance till around Xmas time :( as it's mostly bug free (for the main site) I thought I should launch it :)
The code is 100% open source. It is built on the Kohana PHP framework and you can laugh at it here:
http://hg.errant.me.uk/startupwiki
(seriously; it is a serious mess. That is a product of working on it in fits and spurts)
If anyone wants to contribute fixes, ideas and other code please do so!
So... enjoy :) go add your Startups! You dont need to be registered to edit / add to the site - but if you want to sign up then you get a teeny bit more value (like no captcha's once you have 5 Karma!)
(oh, btw I love the name startupwiki but all the domains except .co.uk were taken. if anyone can suggest a better idea I will happily consider it). <comment><USER2> It does not seem to be working. Is your page down ?

www.startupwiki.org (and www.startupwiki.net) works though -> and that seems to be in German

<comment><AUTHOR> this is the day I am having..

I meant .co.uk ;) just had .com on the mind.

Sorry (& thanks)

</comment></comment><comment><AUTHOR> Clickable links: <http://www.startupwiki.co.uk>

<http://hg.errant.me.uk/startupwiki></comment>


'Low End' Means Good Enough - <AUTHOR> http://lowendmac.com/2017/low-end-means-good-enough/ <comment><USER2> It's pretty hard to take this article seriously.

The author writes

"I don't consider Windows good enough. Historically there have been to many ways to compromise a Windows-based computer, and new techniques keep showing up with alarming regularity."

And then later

"I am writing this on my newest computer, a Late 2008 Aluminum MacBook running OS X 10.11 El Capitan"

If you're going to knock Windows on a lack of security, at the very least do as much as you can do to protect yourself on a Mac. Note the long list of security fixes in the latest version of MacOS [https://support.apple.com/en- us/HT201222](https://support.apple.com/en-us/HT201222)

<comment><USER3> Yeah, the security track record of post-Vista Windows is far better than OS X.

<comment><USER4> Anecdotally, I have never had a virus on Mac (that I detected) and neither did any friends, but Windows got infected all the time. This was true going back to Windows 95.

<comment><USER5> Anecdotally, I've never had a virus on Windows dating back to Win98. But my extended family have had multiple on OSX.

My point is that both are very vulnerable, precautions are what keeps you safe.

<comment><USER6> > _Anecdotally, I 've never had a virus on Windows dating back to Win98. But > my extended family have had multiple on OSX._

Did they really have viruses (of which for OS X there are very few and far between, to the point of lore) or trojans?

</comment></comment></comment></comment></comment><comment><USER7> One of the interesting developments over the past decade is that computers remain usable for much longer than they used to, unless you are a gamer or need to do heavy programming work.

My 2011 Macbook Pro is still perfectly usable for everything a normal person would want to do with a computer. So is my parents' 2012(?) Mac Mini. I just bumped the RAM up to 8GB on both of those computers and they are just fine for web browsing, word processing, and HD video playback.

I suspect that Apple's problem selling iPads is related to this -- my iPad Air 2 is never noticeably slow doing any task, and I know people with pre-Air iPads who are perfectly happy with them. These are people who have plenty of money to buy a new iPad and would do so if theirs felt slow; they just don't notice any drawbacks to using an older one.

<comment><USER8> What? iPad Air 2 is slow as hell in many websites and always when using more than one application. I recently had to buy a laptop just because doing any kind of work was really slow on the Air 2.

<comment><USER9> I don't know, I'm perfectly happy with my iPad Air 1. It's not as fast as my fancy laptop, but it doesn't have to be. It's a very pleasant web-browsing device.

</comment></comment></comment><comment><USER10> >> From a practicality standpoint, the top choice would be that last generation 2011 17″ MacBook Pro

This is actually a bad idea - the 2011 15/17" MacBook Pros have dying graphics chips, that Apple stoppped repairing at the end of last year.

<comment><USER11> My wife still uses my 2011 17" MBP. The graphics has been replaced once for free. If it were not for the failing graphics chips, it's definitely 'good enough'.

<comment><USER12> if you buy one used, they won't replace the graphics for free.

my employer still have "late 2012" MBP with the nvidia-of-death cards as I call them, and apple haven't replaced any of them. Even in 2013.

This whole article is a disservice. You do not need a second machine to write. And even if I needed, i'd use a machine that runs the latest linux with all the security considerations of a modern system, and then I would just install my text editor and nothing else.

This is nothing but a gateway drug for people to join the mac cult. Meh. Not even an expensive mac is any good. let alone a free one. As mac fans always reminds us: you get what you pay for. And free+mac tax = lousy machine.

</comment></comment></comment><comment><USER13> I use a 1998 "Wallstreet" PowerBook G3 running OS 9.2 and MS Office 98 for word processing, some email, and spreadsheets. No Wi-Fi, so I tether it to another laptop via Ethernet.

<comment><USER14> Why not just use the other laptop?

<comment><USER15> Probably widescreen with a flimsy keyboard, while older laptops are more likely to be 4:3 with a nicer keyboard.

Or maybe to avoid getting distracted by all the stuff available on newer computers (going to guess much of the internet is not easily accessible from Mac OS 9.2).

Or maybe just cuz it's cool.

</comment></comment></comment><comment><USER16> My SO is still using a 13" early-2011 MBP, recently upgraded with an SSD and 16GB of RAM, and running the latest OSX release. With only it's original 4GB of ram it was constantly swapping on more recent releases of OSX, which was pretty painful, but it operates just fine now. A brand new 13" MBP would have longer battery life, weigh less, and have a High-DPI display, but wouldn't really be any faster in day-to-day use (and it wouldn't even support more RAM!). I was pretty surprised by how little computers had improved in the last six years.

<comment><USER17> I just picked up a 2011-era Air for a client. Honestly, after installing a new battery, it barely felt any different than what is available today.

<comment><USER18> That's my daily driver. It's amazing. I looked at About This Mac recently and was shocked that it's 6 years old! I could've sworn I had bought something newer. Time flies on a good machine.

<comment><USER17> I'm more of a PC guy, but I have to admit, I really liked it. Good screen, great keyboard and touchpad. Good battery life once I swapping in a new pack.

(Significant minus for those stupid non-standard screws, though.)

I could easily see using one as my daily use machine if I was in a more mac- centric environment without feeling like I was missing anything at all.

</comment></comment></comment></comment><comment><USER19> I thought the nostalgia of the cult of mac from the early 00's was long and dead... but I guess old habits die hard. I wonder what it will be like when the next generation talks about browser versions because to me that's basically the future. Most of the applications I use vary a tiny bit from mac to windows. Gmail, Sublime, Adobe Illustrator, Dropbox... the applications seem to match closer in parity whilst the OS's that host them get more different.

Also his mention of Windows security is a little tired.

<comment><USER20> For young people today, their computers are their phones.

</comment></comment><comment><USER21> So I recently switched from a brand new top of the line Ideapad Yoga to an older Thinkpad from 2012. Sure, it's kind of thick. 1.2" thick actually. But it has a 3.8GHz processor that can actually sit at 3.8GHz for a very long time because of the giant fans and fat copper heat pipes, and it has 8GB of ram upgradeable to 16, and a decent solid state drive. It looks like a giant hunking black thing, and I love it. Doesn't look expensive, so it won't get stolen, and it cost me $250, so even if it does it won't be the end of the world.

I think there'll be a minor trend of people keeping the same laptops they have, or buying older laptops to save money, now that improvements have stagnated. Processors are literally getting slower - I challenge you to find a laptop today that is faster than my X230T. Sure, manufacturers might claim a higher clock speed, but with modern horrible thermal management they can only sit there for brief amounts of time. The X230T can literally sit all day at 3.8GHz, and fairly quietly too.

Sure you can go 0.6GHz faster, with the Alienware 18 with a 4.4GHz processor, but that costs six thousand dollars, is as thick as six laptops stacked on top of each other, and is twenty two inches measured diagonally. Oh yeah, and people found that because of heat problems the processor wasn't able to reach the clock speeds claimed. This review [0] shows that it only got to 3.2GHz, which is substantially slower than my $250 laptop. Oh yeah, and that laptop easily goes over 100F on the outside of the case in normal use, so not only will your legs be crushed by the 12 pound 22" monstrosity they'll also be burned if you dare put it on your lap.

[0] [https://www.notebookcheck.net/Review- Alienware-18-Notebook.1...](https://www.notebookcheck.net/Review- Alienware-18-Notebook.102566.0.html)

<comment><USER22> I got an equivalent Haswell processor on my 13inch and have never ever experienced CPU throttling even while gaming.

It's very very rare for non-ultrabooks to throttle and usually when it happens is because some manufacturers intend it for whatever marketing reasons and not due to heat really building up.

You likely wouldn't benefit from a 7700 in a laptop in real life tasks but to suggest that all new laptops with high end processors throttle enough that your old one ends up performing better is an outlandish exaggeration.

Not to mention that the GHz race has been over for some time now and clockspeed isn't all that matters.

<comment><USER21> Post-Ivy Bridge mobile Intel processors can't maintain the same maximum all- core clock speed as their predecessors. If you're looking for proof, take a look at Intel's marketing materials for the processors: they start marketing the Turbo Boost clock speed as the "Turbo Boost (single core)". That's because the processor won't let you Turbo Boost the entire processor to the maximum clock speed, only one core.

For even more proof, to dissipate power you need a lot of copper and some giant fans. The X230T has a substantial amount of its very thick (1.2") body dedicated to heat pipes, fans, and copper fins. A handful of things I work with are very closely related to heat (Peltier elements, batteries, and motors) so I often look at things with a thermal camera to see how heat is dissipated throughout the laptop. In the X230T I was very impressed: Lenovo's engineers did a fantastic job. The laptop is capable of a substantial amount of heat dissipation. Meanwhile in my previous, fancy, new Yoga Pro laptop with the fanciest processor you can put in it, the thermal management is crap. There's a tiny little fan maybe 5mm thick that sits in a strange place and doesn't seem too effective at anything except making noise. The same goes for every other recent laptop I've seen: most of them seem deadly afraid of making the laptop too heavy or too thick, so they sacrifice heat management.

For the equivalent Haswell processor, maximum TDP is 55 watts vs approximately 40 watts for mine. So your laptop, which is almost undoubtedly thinner and with worse thermal management, has to dissipate almost 50% more heat. And don't go thinking there might be some revolution in heat management that lets yours dissipate more heat in a similar space, because "copper plus fans" has been the formula for the past 30 years. (With the exception of water cooling and peltier elements, which are most certainly not in your laptop.)

Furthermore, if your processor is putting out 55 watts of heat, _more than_ 55 watts have to go in somewhere. So that's also draining your battery. Standard batteries are around 45ish watt hours in recent laptops, so assuming the rest of your laptop (screen, RAM, motherboard, Wifi, hard drive, etc etc) literally drains zero power you'd have less than 45 minutes of battery power at maximum load. Does that sound like something that would freak out a consumer? Yep. So even if the laptop was thermally capable, this maximum power mode is always limited so the consumer doesn't freak out about getting a battery life measured in minutes.

Meanwhile, my Thinkpad, which has a 55 watt hour battery, lasts about an hour and change at maximum power. Did this freak out some people? Maybe. But 2012 Lenovo said "yep, we want to give our consumers maximum power, and if they drain their battery that's their problem." Personally I love it. If I want to limit performance I can just put it in energy saving mode. But most of the time I keep it at maximum, because I like it and in a world with good RAM and a nice SSD the CPU starts to become a bottleneck reasonably often.

</comment></comment></comment><comment><USER23> I wonder what would have been if Apple kept pushing the AppleII line in a much more gradual tech road map.

[https://www.youtube.com/watch?v=7h4tepFbMso](https://www.youtube.com/watch?v=7h4tepFbMso)

In my opinion - computers should still have a boot to basic with a simple interface to vga graphics and passable sound. Something like pico-8 but a better editor with VI bindings. :-)

It's a good thing we have the raspberry pi.

<comment><USER24> Well, we had the awesome IIGS (and the horrible Apple III :^P)

<comment><USER25> Too bad it was intentionally crippled so as not to create competition for the more expensive (and technically inferior in many ways) Macs of the time.

<comment><USER26> Can you elaborate? I hadn't heard this before.

I remember the IIgs being a pretty sweet machine.

<comment><USER25> The main thing I remember being crippled on the IIGS was the CPU clock speed.

The 8-bit guy did a video about this a while ago: [https://www.youtube.com/watch?v=7h4tepFbMso](https://www.youtube.com/watch?v=7h4tepFbMso)

</comment></comment></comment></comment></comment><comment><USER27> Question. There are several mentions of $gigantic_resolution either providing the same or less display area than $smaller_resolution.

Are there any hacks that can convince macOS (or the older versions of OS X described in this article) _not_ to treat the display as HiDPI? Yeah, I realize the machine will abruptly feel like it needs a magnifying glass to use, but in a pinch (laptop on lap <2ft from eyes) it might work for some (insert standard disclaimers here about eyes being non-replaceable and needing to last the distance).

Also.

The late-2015 21″ iMac is ~$1.5k+, and "has a multi-core Geekbench score of 5623."

Then the late-2011 17″ MacBook Pro which is ~$1.3k checks in with a "9240 Geekbench score".

Is there some datapoint I'm missing here?

<comment><USER6> > _Are there any hacks that can convince macOS (or the older versions of OS X > described in this article) not to treat the display as HiDPI? Yeah, I > realize the machine will abruptly feel like it needs a magnifying glass to > use, but in a pinch (laptop on lap <2ft from eyes) it might work for some > (insert standard disclaimers here about eyes being non-replaceable and > needing to last the distance)._

macOs already supports several resolutions higher than the standard 1/2 _native which is what Retina uses (half the native pixels at each dimension for twice the resolution).

IIRC, already the "default" resolution on newer MBPr with the touch strip is higher than the 1/2_native (that used to be the default on retina laptops).

There are also apps like: [https://www.thnkdev.com/QuickRes/](https://www.thnkdev.com/QuickRes/) and [http://www.madrau.com/](http://www.madrau.com/) for more flexibility and full-native resolution even.

That said, the full native retina resolution on something like a 15" screen doesn't make any sense to me except for some special circumstances (maybe 4k movie viewing, but doesn't that already use the full resolution?).

> _The late-2015 21″ iMac is ~$1.5k+, and "has a multi-core Geekbench score of > 5623." Then the late-2011 17″ MacBook Pro which is ~$1.3k checks in with a > "9240 Geekbench score". Is there some datapoint I'm missing here?_

Yes, one is a GeekBench 3 score, the other is a GeekBench 4 score. Scores of 3 and 4 editions of the GeekBench suite are not comparable.

<comment><USER27> > _Yes, one is a GeekBench 3 score, the other is a GeekBench 4 score. Scores > of 3 and 4 editions of the GeekBench suite are not comparable._

Ah, _that 's_ what I was missing. Thanks.

</comment></comment></comment><comment><USER28> Still running my late 2006 aluminum Core 2 Duo Macbook pro, upgraded, with 10.6.8 snow leopard. Unfortunately it occupies an awkward space between homebrew and the "tigerbrew" fork... Everything tries to compile and often fails because of out of date compilers.

I think I'm trying to run too much locally, so these days I am still getting a lot done using cloud VM's.

A computer like that really helps you write efficient javascript.

</comment><comment><USER29> >> I can't get too excited about the 2016 13″ MacBook Pro with 2 Thunderbolt ports. It has a Retina Display, but its 2560 x 1600 pixel display shows no more than my current MacBook's 1280 x 800 display.

Huh? Out of the box resolution is 1440x900 and maxes out at 1680x1050 (without using a 3rd party application like SwitchResX). Apple used to set the default to 1280x800 but this is no longer the case.

<comment><USER30> The author doesn't know what he's talking about. Credibility of the website goes down a lot, even though the main idea is good.

<comment><USER21> It's one mistake for crying out loud. If you're at all interested in a brand new Macbook you aren't going to be considering a laptop from a decade ago, so it also is completely immaterial.

</comment></comment></comment><comment><USER31> To add to the critiques: the usable space on a 13" retina MacBook pro can be increased in the software to support up to 1680x1050 if I'm not mistaken. Further, there are apps that can extend that up to the native resolution.

<comment><USER32> Correct. I'm on a 13" mid-2014 mbp scaled to 1680 x 1050.

</comment></comment><comment><USER33> A IIcx with the full page display, 6.0.8 and Word 5.1 was a great writing environment. In some ways I'd still prefer it to my current Word 2016.

</comment><comment><USER34> for text anything with a terminal is fine...

If it can do vim and owncloud I'd be golden for text.

I do however work with media, so no, low end is not good at all.

</comment><comment><USER8> 42/60 GB available, so no. It's just a slow POS.

<comment><USER35> We've banned this account for breaking the HN guidelines repeatedly. This comment was merely unsubstantive, but others you've posted have been much worse. If you don't want to be banned on HN, you're welcome to email email@example.com and promise to follow the site rules in the future. But please don't create accounts to break the rules with.

We detached this comment from [https://news.ycombinator.com/item?id=14535697](https://news.ycombinator.com/item?id=14535697) and marked it off-topic.</comment></comment>


Startups can do email marketing for free, from CakeMail - <AUTHOR> http://www.cakemail.com/startupoffer.html CakeMail offers free email marketing accounts to startups, up to 25,000 emails per month. <comment><USER2> I guess sending large volumes of mail must be difficult...somehow. There are several services like this (and sure it's cool that it's free and all), but I've never been able to understand what's so hard about sending a few thousands emails. I've built bulk mail senders on a whim on several occasions...when we re-launched our website, and the passwords had to change because of different encryption, I sent out 5000 messages by writing a 25-ish line perl script to pull addresses from the database and queue up the messages. Put a 1 second sleep after each message, and things never get out of hand, as far as server load or bandwidth usage--in fact, it was completely unnoticeable and the system was in service the whole time as both our web server and email server. I've done the same with as many as 20000 recipients and multiple sending SMTP servers. It's just such a simple task that it wasn't even worth looking on the web for an off-the-shelf solution.

What is it about sending out a large volume of mail in one burst that frightens people so much? I'm sincerely curious...I see it brought up quite frequently among startup founders as a serious problem worth spending money on. If your list isn't a spam list--e.g. 90% bounces and errors--sending out mail is trivial, right? I guess if we're talking about a million recipients...but, I can only think of a few companies that could possibly send to a million recipients without it being unsolicited (and those folks are dropping it into mailboxes on their own systems in a large percentage of cases...Google to gmail, Yahoo to @yahoo.com, MS to hotmail.com, etc.). Heck, many of our non-technical users use off-the-shelf stuff, like PHPList, to send out newsletters to a few hundred or thousand users, without giving it a second thought.

What am I missing?

<comment><AUTHOR> Sending emails is not rocket science. But it begins to be more complicated when you want to serious about it:

First, you'll want to automate bounce processing. There is typically a 2.5% churn rate per month on average on a list. You'll start to be blocked at 10% at many ISP.

Second, you'll want to be authenticated if you don't want to be tagged as a spam. Think of configuring SPF, SenderID, DomainKey and DKIM.

You'll also want to remove recipients that will tag your email as spam, and that will happen, no matter what. For that you'll need to have your feedback loops configured at major ISP, and unsubscribe the plaintiffs as you get the reports.

And we're still not talking about calculating open-rates, click-rates and reporting them in a way that is efficient and gives you insights about your marketing operations.

It all depends on how your value your time. We think you have better to do than tweak yourself an email marketing solution.

<comment><USER2> "First, you'll want to automate bounce processing."

Good reason, and something I've never had to deal with. Every mass-mailing I've ever done has been a one-off.

"Think of configuring SPF, SenderID, DomainKey and DKIM."

You have to have (most of) this stuff, anyway, if you send ANY amount of email. It's not limited to mass senders--if you're sending mail as part of your business, you have to deal with spam prevention schemes of many types. SPF being the most widely implemented at this time.

I guess it comes down to regular mass emailing, which is something I've never done. So, I can see value in handling those problems.

Consider question answered, and point conceded. (I don't foresee needing this kind of service, since we don't do mass mailings on any regular basis, but I can imagine folks who would.)

</comment></comment></comment><comment><USER3> Does this have something to do with this thing they call "spam" that is supposedly a problem for a lot of people on those intertubes?

<comment><AUTHOR> Of course not. It's called newsletters, like to one you can subscribe to here: <http://www.37signals.com/>

<comment><USER3> Aaah I see. I have to learn about those newsletter things sometime. Maybe that's why I get so much mail everyday.</comment></comment></comment>


Demystifying Amazon Prime - <AUTHOR> http://www.businessweek.com/magazine/content/10_49/b4206039292096.htm <comment><USER2> I can certainly see how Prime has gotten Amazon to get people shopping in newer product lines.

Before Prime, Amazon was just for books. Now, I've bought books, a few computers, DVDs, a whole set of golf clubs, a 22-foot stepladder, a lawnmower, and I have a standing order for shampoo every three months.

Even the stuff like the ladder and lawnmower were cheaper on Amazon than at Home Depot, I didn't pay sales tax, and it was delivered right to my front door.

It's lowered the barrier to purchase quite a bit -- friends will often recommend books to me during casual conversation, and I'll just pop out my phone and buy it on the spot knowing I can have it in a day or two to read.

</comment><comment><USER3> I love it. I hate going to the store and standing in line, so now I'll end up buying something on Amazon and just wait the 2 days to get it instead of driving to the store. It doesn't hurt that it's usually cheaper, either... And you never have to worry about it being out of stock when you get there. You can always see right on the site for sure.

I wish they'd do groceries and then I would have to deal with that, either.

<comment><USER4> They have gotten in the grocery business (<http://fresh.amazon.com/-> limited to Seattle for now). It's a bit pricier than going to a physical store, but there are some very real advantages: 1. recall emails, 2. filtering based on allergies, 3. not having to rush once you've added a frozen item to your cart, 4. past purchases, 5. reviews.

</comment></comment><comment><USER5> Way more interesting is this (still in trial): <https://tote.amazon.com/AmazonToteLearnMore>

Add in a feature it doesn't have: picking up stuff you want to sell on Amazon's marketplace, and you've got something fairly big. Want new stuff? Amazon. Want to sell stuff? Amazon.

It'd kill ebay.

<comment><USER6> If I remember correctly, they did try to take on eBay, but that project was eventually turned into Amazon Marketplace.

<comment><USER5> Yes and the integration with Tote would make it easier for existing Amazon customers (pretty much most people) to use Marketplace rather than ebay.

</comment></comment></comment><comment><USER7> I got in on the free for a year student promotion just before I graduated, and it definitely changes the way you buy things, or even think about buying things. Almost anything you want is 2 business days away. Combined with free returns, it turns even $500 HDTVs into an easy impulse buy.

<comment><USER8> Free shipping on the returns is great! It really does change the way you think about shopping.

<comment><USER9> There was free shipping on the returns?!

I didn't get that.

<comment><USER7> It's been there for at least several months. They don't advertise it as much because it doesn't earn them money to do that.

</comment></comment></comment></comment><comment><USER10> The article seems to downplay the 2-day shipping aspect of Prime. I think they're missing the point -- yes, free shipping is nice, but for many people, getting what you ordered in two days in _very_ nice.

</comment><comment><USER11> I used this a bit when I was a student living in dorms, and getting stuff in two days was very convenient. But now the UPS/FedEx aspect is just too much of a hassle to deal with, so I prefer using USPS shipping. How do people get around the problems with having to be home to receive shipments, if you don't live somewhere like a dorm that has a mailroom handling that for you, and don't work at home? After the first time I had to drive to some UPS shipping center to pick up a package, I stopped considering this a viable shipping option.

<comment><USER12> I use it all the time and just ship to my work.

</comment></comment><comment><USER13> "Really what people are paying for is immediate gratification."

They make it sound like its a bad thing. I think that last quote misses the point, I order single items from Amazon using Prime because I know I'll get it in 2 days. As a parent with a young child '2 days' is quicker than I'll be able to get to Target to pick up whatever it is I wanted.

I've ordered toilet paper using Prime...you know it's going to run out in 3 days, but you'll get it in 2!

<comment><USER14> Agreed, I view it as more a low friction sort of thing and also thought that quote was off.

</comment></comment><comment><USER15> _A few weeks later she signed up for Amazon.com's free shipping service, Amazon Prime, which guarantees delivery of products within two days for an annual fee of $79._

A free service that costs $79?

<comment><USER3> Once you pay the $79, you get free 2-day shipping for a year for any products that shipped by Amazon.

Yeah, saying it's 'free' is confusing, since you're already paid for it. 'Unlimited' would probably be better.

<comment><USER16> Unlimited free shipping? :)

</comment></comment></comment><comment><USER17> The only program that I think beats Amazon Prime is Zappos VIP, which gives you free next day shipping. Zappos seems to hand out VIP memberships right and left to keep customers happy.

Of course, now Zappos is owned by Amazon.

Edit: I have both Zappos VIP and free student Amazon Prime, so I'm pretty happy sending my cash to Amazon (not to mention AWS).</comment>


Show HN: Autopilot written in Keras for Self Driving Cars - <AUTHOR> https://littlemountainman.github.io/2019/11/27/selfdrivingfun/ <comment><USER2> > At the current state of my model the model basically just clones the human > driver as good as possible. That means the the amount of brake is higher in > curves

I read in another comment that you are still in high school, so maybe the above is because you do not have actual driving experience. But this is not how human drivers drive.

Human drivers brake _before_ the curves, while usually accelerate during curves. This improves stability.

This is something you may want to consider for your next iterations. In any case, congratulations for your impressive work!

<comment><AUTHOR> Thank you. I have a list of things and I want to add. And it is really long

<comment><USER3> Driving dynamics sounds like it should be lower on the list. This is seriously good work. Looking forward to teaching it to drive stick!

</comment></comment></comment><comment><USER4> good start op. a good next step is add in temporal context (previous frame information) so model may resolve ambiguous cases. see e.g. breakdown of comma.ai openpilot model here (from their twitter, [0]), or the karpathy talk as well.

also, when presenting results, prefer to include a longer demo or sub-demos that show strengths and failure cases, and move to the top of the post rather than bottom imo. for a given reader, implementation details are either confusing and uninteresting (if not subject-matter expert) or predictable and uninteresting (if an expert, you've seen many similar before); audience for implementation details is very small number of people who want to sit down and replicate or check your work. but demos / analysis is always novel and interesting to anyone, so lead with that :)

[0] [https://firstname.lastname@example.com/decoding-comma-ai- openpilo...](https://firstname.lastname@example.com/decoding-comma-ai-openpilot- the-driving-model-a1ad3b4a3612)

<comment><USER5> That medium link is awesome. I've been trying to find more links that dive into the innerworks of comma ai's openpilot. Do you have any more similar articles that you can recommend?

<comment><USER4> for specifics, would recommend to simply read the code. for overall context, geohot has done interviews ([0], [1]) and that give overview of comma/openpilot at high level.

[0] [http://www.autonocast.com/blog/2018/7/13/91-hotz-takes- with-...](http://www.autonocast.com/blog/2018/7/13/91-hotz-takes-with-commaai) [1] [https://youtu.be/iwcYp-XT7UI?t=1605](https://youtu.be/iwcYp-XT7UI?t=1605)

</comment></comment></comment><comment><USER6> Seems really scary to exclusively use a neural network for safety-critical tasks like this, without having an explicit method guaranteeing safety.

You can't prove that a trained neural network is always correct, and thus this is likely going to kill someone at some point.

I think you definitely need a LIDAR (or in general something that can give an accurate 3D map of all surroundings) and some explicitly written code that can be proven to result in never hitting a car going the opposite direction in the opposite lane (provided they stay in their lane), as well as never hitting stationary obstacles and never going off the side of a mountainside road.

<comment><USER7> My cat's collision avoidance can be both outstanding and abysmal. Context: she's running a _purely vision based_ system at the moment (supported by elastic proximity sensors at the snout and excellent remote sensing for both chemical and acoustic stimuli) and she _still_ bumps against my leg several times a day. And not just once but repeatedly. Something might be bugged here as she's not having issues with any other static and most dynamic objects either. I'm not sure about the details but since she's not getting any explicit upgrades to her high resolution 3D map, so she might using an advanced SLAM system. The latter is supported by observations that she has no troubles moving in previously unseen environments like while being at the vet. Acceleration is good, agility as well, still sure-footed too, so her movement predictions and the execution seem to match well. So the only complaint is the frequent bumps against my leg. Maybe her system is misclassifying something as she's not having problems otherwise. Does not need to have a LIDAR upgrade, I think.

Edit: thinking of it more she _does_ show this exact problem with other objects as well. Might need to debug her or get a decision-explaining version of her net installed.

<comment><USER8> Just in case you're not trolling: Cats do this _intentionally_ to show affection, scratch themselves and mark things.

<comment><USER9> "It's not a bug, it's a feature."

</comment></comment></comment></comment><comment><USER10> Great job! This is amazing. Love how I'm you used off-the-shelf components. Congrats and keep going!!

<comment><AUTHOR> Thank you

</comment></comment><comment><USER5> You do something similar in Udacity's SDC nanodegree but you use their simulator rather than a new car. Interestingly through trial and error on my project, ELU activation functions was the only thing that prevent vanishing gradient problems. You use the same activation function and I'm curious why you selected that one. I always wonder why it was the only function that worked for me.

<comment><AUTHOR> Because you can still find the best gradient with ELU. Say you use sigmoid and you have big weights then your gradient can get stuck

<comment><USER5> Thanks for the answer! I also used Relu with no luck either. I figured Relu would work better than ELU but it didn't work for this application. Would you happen to know why ELU is superior to ReLU?

<comment><AUTHOR> RELU is really good for mostly positive weights. ELU is good for both

</comment></comment></comment></comment><comment><USER3> Holy crap.

First: you're awesome. Keep it up. Second: anyone else think this is a great example of how autonomous driving is a last-mile problem?

<comment><AUTHOR> Thanks

</comment></comment><comment><USER11> How big of a risk is overfitting for these kinds of models? I think common practice is to hold back some of the data for testing.

<comment><AUTHOR> The risk is extremely high.

</comment></comment><comment><USER12> Just out of curiosity how old are you? Keep up the good work!

<comment><AUTHOR> I am 14.

<comment><USER12> Keep it up! You have a big/good/fun future ahead of you!

</comment></comment></comment><comment><USER13> >A few days ago @karpathy presented their workflow with PyTorch and also said some numbers, to train the Autopilot system with all it neural networks you would have to spend 70,000 hours with a decent gpu - that is around 8 years (depending on which GPU you are using). In total the Autopilot is a system of 48 Neural Networks. When we compare this to what I will show you, you are gonna see that this is insane.

I'm very confident that it is not insane, for reasons that you have yet to discover, and the arrogance of calling insane inspires a fear in me considering what you appear to be doing on roads with other people.

Your project is very cool, but also very irresponsible. Are you using this on the road with other drivers? For the love of all things good, what are you thinking? Please clarify this. It's one thing to trust your own life to your creations, it's another thing to endanger everyone else's.

<comment><USER14> Whoa, before we start pulling out the pitchforks, I think this may be terribly distorting OP's words and intent.

\- My reading of it was that OP was in awe at the immense scale of engineering that went into Autopilot to make it production-ready in contrast to his own project which gives a perspective into what it takes for a HelloWorld in this space (he comments on its limitations: "That is just lane keeping so far but it does quite a good job at doing it. It is still a bit weak when wanting to predict the angle when there is an intersection and it doesn't see the next road and say there is an highway exit.")

\- The github project looks to be using an existing recording of a car driving from the comma2k19 dataset and predicting the expected vehicular response. No pedestrians endangered.

\- Not that this should matter in an ideal world, but it appears the author is a talented young programmer who's still in school. It feels a bit much to admonish a newcomer to the space for perceived arrogance and irresponsibility; and even if there were at all real critiques to be made here, I'm sure there's a less rude way to make that argument that wouldn't discourage students from their learning journey.

<comment><USER13> >The github project looks to be using an existing recording of a car driving from the comma2k19 dataset and predicting the expected vehicular response. No pedestrians endangered.

You sure? Yes, he's using a dataset for training, but nothing about his post indicates he's not running it the trained model on real roads. He claims to be _testing_ the trained models:

>I did a few tests where pedestrians where suddenly crossing the road and the model gave it's best job to not hit the human crossing the road.

How is he running these feedback tests? If the angle of the steering wheel changes the video input that is produced, how can he test that the AI would avoid hitting the human, unless he's testing in real life?

>My reading of it was that OP was in awe at the immense scale of engineering that went into Autopilot

He said how impossibly-long Autopilot's models take to train, and then goes on to say "When we compare this to what I will show you, you are gonna see that this is insane." It sounds like we're reading this differently, but to me, that sounds like "what they're doing is so over the top, you can achieve pretty good results in this space at a fraction of that, and I can prove it."

>It feels a bit much to admonish a newcomer to the space for perceived arrogance and irresponsibility

I don't care about what he's pursuing, and if you took it that way, then understand it is not my intention. I care that he is essentially putting a drunk AI driver behind the wheel of a car on roads shared by everyone, and endangering their lives. Apparently that's an unpopular opinion, given some of the responses ("big tech companies do it and bribe politicians to get away with killing people"). But I think it's the responsible opinion.

<comment><AUTHOR> Again I am not testing on real roads. The sentence When we compare this to what" I will show you, you are gonna see that this is insane" should mean that those numbers from Tesla are insane. And my project is not insane. That's what it should mean

<comment><USER15> I think the word 'insane' is difficult to interpret in this context, and this is why people are struggling to understand your meaning.

It could mean "they're idiots for training for so long", or could mean "it's amazing how advanced/computationally intense their model/training is".

</comment></comment></comment></comment></comment><comment><USER16> Neat project, at a minimum this should get you hired somewhere fancy. I'd love for all the self-driving car vendors to take a leaf out of your book and keep their software in-house until it agrees with what the real drivers do > 99.99% of the time and the other 0.01% led to an accident of sorts.

<comment><AUTHOR> I hope this gets me hired somewhere although I dont even have a high school degree yet

<comment><USER16> That is nothing short of amazing. I sincerely wish you best of luck, do get that high school degree though, and more if you can, it will put you in touch with other smart people. When I had a company in Canada there were two people working for me that were still in high school - and later in University. The one went on to become a multi-millionaire by the ripe old age of 30, the other ended up doing lots of great stuff at Google. You are on the right track :)</comment></comment></comment>


Show HN: We made an app for managing your Twitter favorites - <AUTHOR> http://faavorite.com <comment><USER2> Oh boy, finally! I've been looking for a Twitter Favorites-manager for a long, long time. Glad finally someone is addressing the problem.

The overall usability is a bit weird (but based on your poll I wasn't the only one - 85% also said the same :)) but hey, it's already 10x better than any other alternative.

Hope you guys continue to develop the product and find creative ways to make a business out of it.

<comment><AUTHOR> Thanks for the great comment! We're really excited about faavorite and we're thrilled to have you on board :D

H

</comment></comment><comment><AUTHOR> Also guys—anyone reading this who's signed up—if you have any non-tech Twitter friends you might want to invite that'd be awesome! A quick glance over the site should tell you that the majority of users so far are web-dev types and we'd really like to diversify sooner rather than later!

Cheers, Harry

</comment><comment><USER3> Great App! I favorite tweets for reading them later, but with the tagging, seems like I can expand on that.

Suggestion -- I can now only see 3 tweets on the screen (1920x1080), because of all extra buttons/text/tags. Is there a way to collapse ?

<comment><AUTHOR> Thanks! That's a great question, we need to ponder that because faavorites _do_ take up a lot of space because of all the other data they carry. Perhaps a toggle between all open and all closed…?

<comment><USER4> I'd like an "Express View" like that too, to get more on the screen. Maybe smaller text in each too.

</comment></comment></comment><comment><USER4> Your site is claiming I have 792 Favorites (Twitter won't enumerate). Will all those be able to import?

<comment><AUTHOR> Sure thing, we can grab all of those (unless any were authored by a protected user).

EDIT: If you have a particularly large amount of favorites, faavorite will put you on a drip-feed import where we just grab them 200 at a time. This means you can still look around the app (or go make a coffee, or go to bed, or anything) and we'll just grab them for you until we get all of them.

</comment></comment><comment><USER5> Possibly of additional interest is a writeup of the tech stack powering faavorite.com which somebody submitted a couple of weeks ago: <http://news.ycombinator.com/item?id=3802872> :)

</comment><comment><USER6> I have to give the faavoriteapp crew a big thumbs up vote. Excellent for those of us who use Twitter to track things & people we want to bookmark for later reference. Great design, use it often.

</comment><comment><USER7> I am quite a regular user of faavorite, it gives me a reason to favourite tweets which beforehand was pretty useless!

</comment><comment><USER8> not to be a jerk, but organize is spelt incorrectly in your title tag. should be 'organize' not 'organise'

<comment><USER9> -ize or -ise are often style matters and not spelling errors.

(<http://oxforddictionaries.com/words/ize-ise-or-yse>)

(<http://blog.oxforddictionaries.com/2011/03/ize-or-ise/>)

</comment></comment><comment><USER10> Really Cool! . a little Marketing brushup and you'll go a long way.!

<comment><AUTHOR> Thank you!

> a little Marketing brushup and you'll go a long way

This is where we're struggling at the moment; we're just a couple of devs on a hobbyist app right now. The next 'sprint' we're hoping to dedicate to marketing and ideas and the like :)</comment></comment>


It was Bill Joy's password, not Ken Thompson's, that had a control character - <AUTHOR> https://minnie.tuhs.org/pipermail/tuhs/2019-October/019125.html <comment><USER2> The current title ("It was Bill Joy's password, not Ken Thompson") I assume is in reference to Ken's password being cracked two weeks ago. The title is not correct. Ken's password was cracked. Bill Joy's password has now also been cracked, but not disclosed w/o getting permission from Joy to do so first.

Discussion from two weeks ago - [https://news.ycombinator.com/item?id=21202905](https://news.ycombinator.com/item?id=21202905)

Message posting /etc/password entries - [https://minnie.tuhs.org/pipermail/tuhs/2019-October/018854.h...](https://minnie.tuhs.org/pipermail/tuhs/2019-October/018854.html)

Message showing Ken's cracked password - [https://minnie.tuhs.org/pipermail/tuhs/2019-October/018917.h...](https://minnie.tuhs.org/pipermail/tuhs/2019-October/018917.html)

Message showing Bill Joy's hashed password - [https://minnie.tuhs.org/pipermail/tuhs/2019-October/018955.h...](https://minnie.tuhs.org/pipermail/tuhs/2019-October/018955.html)

A correct title would be "Bill Joy's password has now also been cracked."

<comment><USER3> The title is in reference to which password contained a control character. It is truncated, but not incorrect.

<comment><USER4> Ok, we've put a control character in the title above.

(Submitted title was "It was Bill Joy's password, not Ken Thompson"... also a category error to compare a password to Ken.)

<comment><USER5> Could be simplified to "Bill Joy's password had a control character", since no one had announced a thought that Ken's password had one, so the misdirection is pointless distraction.

<comment><USER3> [https://twitter.com/TychoTithonus/status/1185211446537273344](https://twitter.com/TychoTithonus/status/1185211446537273344)

<comment><USER2> Ah, a link to that tweet in the first place would've made a lot more sense.

</comment></comment></comment></comment></comment></comment><comment><USER6> For everyone who finds this story confusing, I'll try a recap:

The password file on UNIX systems from 1969 right up till the 1990s were readable by everyone on the system. However, the passwords were one-way encrypted or "hashed". For the password a user typed such as "p/q2-q4!", the password file contained a hash such as "ZghOT0eRm4U9s". It used to be a rite of passage of every aspiring UNIX systems programmer to write a cracking program to discover some of the passwords on their system -- typically by encrypting a dictionary of words to see if any matched up with the hashed values in password file. If everyone picked good passwords, this was futile. But on any large UNIX system, many users selected dictionary words so this attack was often successful.

Recently someone unearthed the password file from one of the original systems on which UNIX and C were developed. Naturally it's great fun to discover the original passwords of all the UNIX luminaries such as Ken Thompson (his strong password being a chess move "p/q2-q4!"), Dennis Ritchie (password "dmac" \-- anyone know what that might mean?), Brian Kernighan (an easy to type keyboard pattern "/.,/.,"), Steve Bourne, inventor of the Bourne shell, didn't seem to care and chose obvious password "bourne", and more here [https://news.ycombinator.com/item?id=21209594](https://news.ycombinator.com/item?id=21209594).

One lone password from the original list, Bill Joy's password, was still uncracked. Bill Joy is the co-founder of Sun Microsystems, author of vi, and a key developer of BSD UNIX. He apparently picked the best password. This latest news says that Bill Joy's password has now been cracked, that it uses a control character in place of a letter, it is otherwise all lowercase letters, and is a chess related term (as Ken Thompson's was also chess related). An an example, his password could be chess-related word "c^Astlng", where the ^A is control-A (but it isn't -- I checked). But the actual password has not been revealed "because of the outpouring of negativity about these disclosures, [the discoverer is] reluctant to post the actual password without [Bill Joy's] consent".

<comment><USER7> Pretty interesting that those guys took what are essentially joke passwords. Seems like they probably didn't expect anyone to bother trying to crack them.

</comment></comment><comment><USER8> If you read on in the thread there's this fun story[1]:

> John P. Linderman jpl.jpl at gmail.com

> Sat Oct 19 23:11:10 AEST 2019

> Related story. A user came to us with a problem while we were in our > computer room. We asked him to log in at the VAX console, so we could look > into the problem. Moments later, dozens of users flooded in, asking what had > happened. Seems the first user had a CTRL-P in his password, which, when > entered at the console, triggered the VAX to pause.

[1] - [https://minnie.tuhs.org/pipermail/tuhs/2019-October/019137.h...](https://minnie.tuhs.org/pipermail/tuhs/2019-October/019137.html)

<comment><USER9> I do this all the time with bash. I run a python script, and try to ctrl+c the output of it while it's still running. My brain refuses to learn right click.

<comment><USER10> ctrl+shift+c will copy it. :)

</comment></comment></comment><comment><USER11> Bill Joy used a control character:

        Second attempt was lower-case with control characters, and succeeded in
        around 40 minutes.

        There's a control character in it ;)

        Because of the outpouring of negativity about these disclosures, I am
        reluctant to post the actual password without the user's consent, since
        he's still alive. If anyone knows Bill, and can contact him, please ask
        for permission.

[https://minnie.tuhs.org/pipermail/tuhs/2019-October/019124.h...](https://minnie.tuhs.org/pipermail/tuhs/2019-October/019124.html)

</comment><comment><USER12> Plato terminals had a custom keyboard* which included buttons for super and subscripts. The administrator for our school district's account had special privileges including the ability to create new users, give others the right to create lessons, more disk space and was highly coveted. It didn't take too long for someone to figure out Mrs. Kennedy's password was <SUPER>man. Of course my password instantly became yellow<SUB>marine.

* [http://xahlee.info/kbd/plato_iv_keyboard.html](http://xahlee.info/kbd/plato_iv_keyboard.html)

<comment><USER13> > Plato terminals had a custom keyboard

Every terminal and personal computer had a custom keyboard back then.

</comment></comment><comment><USER14> I inadvertently had this on a Sun. I was entering a new password from a remote terminal and accidentally hit a lower case letter where I wanted an upper case one. Reflexively I hit backspace, and the Sun used DEL, so it stored a ^H in the password. I was then unable to change it because while getty or login could handle it, passwd wouldn't accept it as my existing password.

<comment><USER12> Anecdotally pressing ^v triggers quoting so the next character is taken verbatim. So ^v^h should have worked.

<comment><USER14> There was a ton of wizardry I didn't know at the time

<comment><USER12> I hear you. The very first system Unix system I had root to ended up with two etc directories. It took a really long time to figure out I hadn't corrupted the filesystem but instead had created one directory named /etc<DEL> which was an unprintable character.

<comment><USER15> `mkdir -- "$(echo "-rf \u2215")"` is a fun one for someone else to anxiously rm later ;)

<comment><USER12> Lol. The lessons I learned about ls -lq, ls -li and find -inum have stuck with me since then, though.

</comment></comment></comment></comment></comment></comment><comment><USER16> I knew someone who started with DEC minicomputers. His original password included a backspace.

That is, the password might have looked like

1234

but it was actually

12^H34

because at that point, the backspace character was still a terminal command.

</comment><comment><USER6> If anyone would like to try their own hand at discovering Bill Joy's 1970s-era password, here's how to get started with the hashcat tool. First check if everything is working by trying a known result, e.g., Dennis Ritchie's password which we know was "dmac":

      apt-get install hashcat
      echo "dmac" > guesses
      hashcat --force -m 1500 -a 0 gfVwhuAMF0Trw guesses

If see you a message that says, "gfVwhuAMF0Trw:dmac" and "Status: Cracked", it's working. Now put in Bill Joy's hash ".2xvLVqGHJm8M" in place of "gfVwhuAMF0Trw" and a list of guesses, one per line, in the guesses file, and run hashcat again.

We've been told that the password is a chess-related word, all lowercase letters except that one letter is a matching control character, such as in "b^Ishop" where the "i" is actually a control-I.

</comment><comment><AUTHOR> Sorry, the title and I were wrong. now, I read the full story and a better correct title is: "Bill Joy's Unix password had a control character". @dang, please edit the title.

</comment><comment><USER17> A guy I worked with did this once, but on an esxi machine through the web interface. Took a very long time of figuring out what characters to press on an ssh connection from a mac to get the same, then to translate that to windows keyboard. Password changes often warn (or flat-out deny) if your password is too short, similar to username, etc.; maybe they should do so for control characters.

</comment><comment><USER18> So much interesting content is locked in these oldschool mailing lists, how does a modern-day web user get into them?

<comment><USER19> Like the rest of us, get browsing! [https://minnie.tuhs.org/pipermail/tuhs/](https://minnie.tuhs.org/pipermail/tuhs/)

Might as well add a disclaimer: back in the days, in order to find the gold nuggets on the web, you had to shift through shit. A lot of shit. But then once in a while, you find those little nuggets that made the whole shit- shifting worthwhile. Useful exercise in patience for beginner webbers maybe.

<comment><USER20> > _back in the days, in order to find the gold nuggets on the web, you had to > shift through shit._

"back in the day"?

Edit: no, I meant, it hasn't changed since then. Sturgeon's Law still applies today.

<comment><USER19> I did not know that it's "day" not "days". Not a native English speaker and have always been saying it "days". Thank you for correcting me!

<comment><USER21> Both could be correct. Here I think "day" could make more sense. An example of the other case: "Back in the days of Fortran programming..."

If you leave out anything after "days" by just saying "back in the days" then it is like you are pausing. As in when you reminisce, "Oh, back in the days!" Maybe that is what the intention was.

In any case, the commentor was actually just saying that he thinks nothing has changed.

</comment></comment></comment></comment></comment><comment><USER22> They all had their uid set to 0?

<comment><USER23> From memory setting a UID to 0 was a way to effectively have multiple root accounts on a system. sudo is a much better solution to the same problem so using uid 0 in this manner is not something I expect to see on any modern unix/linux system.

<comment><USER24> "shutdown" or "reboot" as a UID=0 user with shell set to "/sbin/shutdown" or "/sbin/reboot" and a specific password is still occasionally found. Log in as that to shut down or reboot system.</comment></comment></comment>


Invitation codes for Writer.is - ivars-indriks

I have invitation code for http://writer.is Code: HCKNW <comment><AUTHOR> is that invite for one registration?

<comment> ivars-indriks Limited time

</comment></comment><comment><USER2> thank you !</comment>


Doomsday rule: calculate the day for any date - <AUTHOR> https://en.wikipedia.org/wiki/Doomsday_rule <comment><USER2> Freshman year of uni I memorized some variant of this, and after some practice I got to where I could do the math in 3-5 seconds.

Protip: Some parts of the algorithm can be subject to a CPU/Memory trade off. In the variant presented in the wiki article, steps 1 and 2 can be combined. Memorize the doomsdays for all of the years of people you're likely to want to calculate their date of birth. For me, this meant memorizing the doomsdays between say, 1980 and 1995.

You can also memorize a modulo 7 table for all numbers you're likely to encounter.

You can get fast enough in the amount of time it takes you to say some canned response "Hmm, I think the date X YYth of ZZZZ would fall on..." you can figure out the answer.

\-----

Though it turns out this is a significantly less impressive party trick as I initially imagined it'd be.

<comment><AUTHOR> People aren't impressed by it?

<comment><USER2> Only a certain kind of people really appreciate it.

Generally, the same kind of people who are impressed by rubik's cube speedsolving (which I _also_ thought would be amazingly cool) are impressed by this. But for a lot of people, they just assume there is some simple trick to it, say "cool" and move on.

And then other people assume you must be some sort of autistic savant.

<comment><USER3> I found the same for the ability to divide numbers by 17 in my head... it really didn't get me a lot of action.

</comment></comment></comment></comment><comment><USER4> Not sure how the doomsday works, but there's a quick way to calculate the day of week just memorizing single digit codes for months. Might be easier to grok from a small script. This is for current century (2000s) in coffeescript:

calculateDay = (year,month,day) ->

      y = (year-2000)%28
      m = [6,2,2,5,0,3,5,1,4,6,2,4][month]
      if month < 2 and y%4==0
          m-= 1
      y += y/4|0
      days = ['Sun','Mon','Tue','Wed','Thu','Fri','Sat']
      return days[(y+m+day)%7]

\--- For years 1600s through current century here's a jsfiddle with a slightly longer method with verification: [http://jsfiddle.net/9zp0zkxz/](http://jsfiddle.net/9zp0zkxz/)

Edit: no idea how to work spacing on comments here

<comment><USER5>
      > no idea how to work spacing on comments here

* Blank lines create new paragraphs,

      Blank line followed by lines with
      leading spaces create pre-formatted
      text - intended for inserting code.

Under most circumstances, asterisks around text creates _italics,_ the exception is when the asterisk is surrounded by space.

\-- [https://news.ycombinator.com/formatdoc](https://news.ycombinator.com/formatdoc)

<comment><USER4> ah, thank you

</comment></comment></comment><comment><USER6> The 'Big Calendar' industry is going down.

<comment><USER7> Big Calendar is already on its way down. How many of us even have calendars?

</comment></comment><comment><USER8> When I wrote my time and date library (luatz: [https://github.com/daurnimator/luatz](https://github.com/daurnimator/luatz) ) I originally wrote an implementation of the Doomsday rule to figure out the day of the week.

Turns out that sakamoto's algorithm (see [https://en.wikipedia.org/wiki/Calculating_the_day_of_the_wee...](https://en.wikipedia.org/wiki/Calculating_the_day_of_the_week#Implementation- dependent_methods_of_Sakamoto.2C_Lachman.2C_Keith_and_Craver) ) was much faster to calculate and made for cleaner code. [https://github.com/daurnimator/luatz/blob/master/luatz/timet...](https://github.com/daurnimator/luatz/blob/master/luatz/timetable.lua#L45)

<comment><USER9> IIRC tzdata just acquired a new version (3) not too long ago and luatz would need to be updated to handle it. You'll only get the new files if they were compiled with a newish zic. This bit me because code I work with is also parsing them :)

<comment><USER8> Thanks for mentioning this, I had no idea... and documentation on this fact is sparse. It's not even mentioned on [https://www.iana.org/time- zones/repository/tz-link.html](https://www.iana.org/time-zones/repository/tz- link.html)

Created an issue at [https://github.com/daurnimator/luatz/issues/2](https://github.com/daurnimator/luatz/issues/2)

</comment></comment></comment><comment><USER10> Why are those days called 'doomsdays'? Anybody knows? (The origin articles don't seem to be online.)

<comment><USER11> Maybe because its inventor is John Conway?

You know, "Conway's Game of Life", "Doomsday rule"... He's not into small names for the things he invented.

</comment></comment><comment><USER12> As I explained to a friend recently, I'm not the type of person who can readily do the calc in my head, but rather the type who would enjoy the tedious work of laying out all the possibilities on paper, as I did with the Periodic Calendar: [http://periodiccalendar.com/](http://periodiccalendar.com/)

</comment><comment><USER13> "Pick a date, any date."

"June 12, 2145."

"A Saturday. In Vancouver, sunrise will be at 5:12am and sunset will be at 9:24pm. There will be a third quarter moon."

"Wow."

[http://www.wolframalpha.com/input/?i=June+12%2C+2145](http://www.wolframalpha.com/input/?i=June+12%2C+2145)

<comment><USER14> [http://www.wolframalpha.com/input/?i=January+2%2C+218129](http://www.wolframalpha.com/input/?i=January+2%2C+218129)

sunrise: not reached :|

</comment></comment><comment><USER15> The First Sunday Doomsday Algorithm is the easiest to learn and also fastest, in my opinion. [http://firstsundaydoomsday.blogspot.com/](http://firstsundaydoomsday.blogspot.com/)

</comment><comment><USER16> This script will test your skills on logon: [https://code.google.com/p/doomsday-sh/](https://code.google.com/p/doomsday- sh/)

</comment><comment><USER17> The periodic calendar provides a map to this math: [http://periodiccalendar.com/learn/](http://periodiccalendar.com/learn/)

<comment><USER12> Thanks, Jeff! The key to the Periodic Calendar is identifying that there are seven types of years, depending on the day of the week that starts it off. At first I thought I needed to make 7 calendars to cover the possibilities, but my aha moment came with the idea of the Gregorian Isotopes, which flip our focus from the day of the month to elements based in days of the week that exist on an array of days of the month.

The core idea is that August 10th is a semi-meaningless count of the days, whereas the real information lies in today being Sunday.

</comment></comment><comment><USER18> This rule is great for convincing people that you are autistic.</comment>


Show HN: Pmdr is a neat Pomodoro time tracker - <AUTHOR> http://pmdr.io/

<comment><AUTHOR> Hi HN users,

Since I'm a big fan of the Pomododoro technique, but never found a satisfying web app, I decided to build my own as a quick pet project.

Since you always have great advices and interesting opinions to share, I'd be glad if you could give it a quick look and share your opinions (criticisms are welcome).

Did I mention it's open-source?</comment>


Erlang: Scalaris Released - <AUTHOR> http://21ccw.blogspot.com/2008/07/scalaris-released.html <comment><USER2> Does anyone have a link to more information on this? Does it compare favorably with CouchDB?

<comment><USER3> Follow the link mentioned on the page. [http://armstrongonsoftware.blogspot.com/2008/06/itching- my-p...](http://armstrongonsoftware.blogspot.com/2008/06/itching-my- programming-nerve.html)</comment></comment>


New Golang Branding - <AUTHOR> https://golang.org/ <comment><USER2> It seems like all modern languages try to capture their goals in a tagline.

The following sites all have similar brands:

[https://golang.org/](https://golang.org/)

[https://nim-lang.org/](https://nim-lang.org/)

[https://www.rust-lang.org/](https://www.rust-lang.org/)

[https://ziglang.org/](https://ziglang.org/)

</comment><comment><USER3> I feel like any new branding have criticism until the audience has enough contact with it. Let's see how it goes for golang.</comment>