skysight-inc/HackerNews huggingface dataset:
I don't think Voevodksky himself has any constructivist leanings. The univalent foundations developments make use of various axioms that have no known constructive meaning (e.g. the law of the excluded middle, and the famous univalence axiom itself), and which are motivated because there are known models in which they hold.

On the other hand, many of his collaborators are interested in the project precisely because it uses Coq and they like constructive mathematics. So the HoTT book only uses exluded middle when necessary (and carefully tracks where), and developing a computational interpretation of univalence is considered to be an important task.

Edit to add: So why would someone who doesn't care about constructivism want to use Coq? Because it's based around typed objects. Apparently, homotopy theorists had for a long time been aware that instead of basing mathematics on sets, and then constructing equivalence classes on top of those, you could take homotopy types as primitive.. something like basing mathematics on blobs rather than points. This was all considered theoretical and impractical--until someone noticed that the logic provided by Intensional Type Theory (as implemented in e.g. Coq) can be considered to do exactly this!
In principle, yes. In actuality, you can always introduce new axioms and work with them.

http://en.wikipedia.org/wiki/Homotopy_type_theory#Univalence...
They're not outliers. Go to almost any large American city and there is a poor area where most of the black people live, and a better off area where most of the white people live. That's America.
Thanks! (I run Now I Know)
Part of the experiment is to test the traction surface. They had a problem with a bicyclist slipping, so they switched from stick-on surface to spray-on surface.

The article says they use an angled surface and natural precipitation to keep the glass clean. I can only imagine how much dirt builds up on a highway over a day. A similar complication would be dirt or sand being blown onto the roadway by wind, or washed there by rainfall.
Why does the additional wealth come into fruition by the toil of poor people? If I have a lot of money and invest it, I don't see how poor people are affected by my investment at all, unless the fact that the money is not being injected back into the economy has some kind of very negative effect on the poor.
Can confirm, in the Netherlands on bike lanes black ice is a much bigger problem than snow. Heating should work fine against black ice while shoving isn't very effective.
This is not a huge problem as if you are outputting the floating point number, you would probably want to round it anyways. The biggest 'gotcha' is when doing equality comparisons between these numbers.

Consider the following:

.1 + .2 == .3 // false

The way to 'get around' this is to have a value (usually called an epsilon) that is relative in magnitude to the numbers being compared. In this example, a value like .00001 as epsilon should work fine.

Anyways, all you have to do is check if the absolute difference of the numbers is less than the epsilon:

var a = .1 + .2, b = .3, epsilon = .00001;
console.log(Math.abs(a-b)<epsilon); // true

In short, try to not put yourself in a situation where you have to compare equality with doubles.
I really wish the "immediacy" aspect were more visibly discussed. It's a great core to the notion of intuition---it also helps separate intuition of a concept from intuition guiding a search for meaning.
I'm amazed that they allowed video recording of the surgery. When I tried to photograph the birth of my nephew, the doctors didn't allow it citing lawsuit concerns.
The article list reads like what Hacker News would have been in 1977.

Why so many computer languages?

The hobbyists operating system

The 8080 you may have missed

...
> I'm actually generating nice Verilog specifications. Can I apply it somehow if I'm not working in Intel or something? What can I do with it?

Throw it into an FPGA
right, but I think he first needs some insight on how IEEE 754 floating point arithmetic works.
Blame Wozniak.

According to his autobiography, he was unaware the numbers even meant anything, he just liked them.
Advice to employers: Interview both and pick the one that seems smarter. (or a better "cultural fit" or whatever other stupid metric you use)

Advice to students: Pick the area that interests you more. If you plan on pursuing a software career, pick at least a minor in CS.
This is probably obvious but why is the existence of singletons what destroys "isomorphism"?
This way I oppose illegal immigration and amnesty for adults. It hurts working class people without that don't have higher education. A disproportionate number who are black. It depress wages at the lower end. It is only one issue in a complicated situation but it is a another thing that is piling on those on the bottom rung economically. It disappointing to see Obama, Bush, Clinton, and some elite people pushing it.
Never have I ever read something about Larry Ellison and thought anything nicer than "what an unbelievably selfish asshole."
One of the reasons is because of the sheer size of roads. It's kind of a strange facet of our economy, one which may shift this century [0], but as it stands roads tend to outweigh buildings in terms of surface area in most countries.

This is interesting because contrary to popular science which says that we can power the whole world with a tiny fraction of land use dedicated to solar panels, surface area is actually one of the biggest challenges we have in a 99% sustainable energy world that we have to get to.

Check out without the hot air, free book by physicist McKay at Cambridge. He's done a 1h presentation at Harvard which tells you the gist of it, and a 15 minutes TED talk which I'd skip unless you really only have 15 minutes. He covers the surface area challenges of solar and other sustainable energies quite well.

The ability then to one day put extremely cheap solar (e.g. at least 1 order of magnitude cheaper than today) in every new road (whose lifespan is a few decades, so we could on paper replace them all halfway through the century), is very interesting.

Of course there are huge, huge drawbacks. But that's not necessarily because it's impossible, but because we have path dependency. That's why you need prototypes and R&D to see how we can build roads sustainably using new materials, and whether solar panels fit into that picture.

[0] Roads are there for a reason: transport. We're now seeing for the first time ever tools on a scale that can cut down transport on a global scale. Still immature, but it's getting there. The combination of internet, 3d printing and virtual/augmented reality, means we can live global lives locally without having to physically transfer ourselves, information or products. It means we can work & study remotely better and experience entertainment and tourism more locally. And when we do move stuff, there's the option of doing it through new channels (air, with drones), or more efficient channels (self-driving vehicles that can attain higher speeds with smaller gaps safely, calculate more efficient routes and turn transport into a commodity: smaller vehicles transporting people, as opposed to cars being branded products, all of which lead to far fewer roads being necessary). It's a very bold claim but I wouldn't be surprised if roads kept explosively increasing until 2025, and then stagnating and at some point sharply reducing after a shift in human culture, manufacturing and transportation.
I'm curious why you consider Matlab not an option to distribute software widely? They have the Matlab Compiler that allows you produce executables that work with the freely downloadable Matlab Compiler Runtime.

I know of at least one software product, Imatest, that is produced and distributed this way.

http://www.mathworks.com/products/compiler/

http://www.imatest.com
its pretty simple, there is obviously a very ingrained faith in the standard organizational structure w/ management, staff. its so obvious that is how things should be (its "fundamental"), that its difficult to consider that belief is possibly also a matter of faith, even if that standard structure was itself emergent in some respects.

its possible the commenter i was responding to was referring more to the "rah rah" aspect of zappos as a whole, rather than religious zeal re: this new organizational concept. those are different things in my mind, also both are exhibited by the directive "to all employees: read this book and indicate you have done so".

anyway it isnt a comment on whether or not the zappos idea itself is useful and/or just another fad coated with new terminology (i have no idea). just that when you can identify someone else as engaging in religious zealotry, its fun to consider what that zealotry is being compared to, which probably turns out to be something like "everybody knows its supposed to be this way", aka. some sorta implicit religion.
Well, it's an article written by a German newspaper correspondent for a German audience... So it's understandable that the author doesn't try to offer solutions.
The Maharishi Mahesh Yogi, trained as a physicist, welcomed, encouraged Western science to validate Transcendental Meditation, a mechanical mantra repetition technique, with the stress on lack of effort which is opposed to mindfulness, concentration, self-observation, and other effortful techniques.

Electro-encephalographs of TM meditators, after just a few weeks of initiation into TM technique, show the various brain waves frequencies spreading from back to front, plus left-right hemispheric synchrony, and increasing in amplitude. This behaviour was seen a few decades ago, and is even more verified lately as detectors and signal processing advanced.

Was do the data mean? That's less "scientific", but clearly something is happening, and subjective reports are that it's a very positive experience with benefits that last outside of meditation.

Why does this behavior persist, is repeatable across many TM meditators, even neophyte meditators? It suggests, verifies even, that the TM technique recognizes inherent properties, abilities, behavior of the human brain.

Again, the benefits, if any, meditative sessions causing whole-brain wave synchrony, coherence, and increased wave amplitude? You'll have to ask TM meditators.
Off topic but how would you have done your Hadoop buildout differently?
When to Use “==”, Equals() and HashCode() on Strings in Java
More accurately you might say that the people who understand the math are somewhat segregated from the people who make the decisions.
And it would be significantly faster than if I would concentrate on optimizing the code for, say, executing it on GPU?
There probably won't be a win on a purely mathematical/financial level at first. 3000 kWh in 6 months is only about $300 worth of electricity at 10 cents/kWh. I don't care how low the cost of paving gets, it's not going to compete with the cheapest form of energy in human history (burning stuff - traditionally wood, then peat, then coal as the availability of fuel inevitably dwindled, and now to deep sea exploration, fracking and tar sands that are only economical if externalities aren’t considered).

The real win (as I see it) is in converting economies from continuous financial outlays going up in smoke to one-time investments with exponential returns spread over similar time frames. Automation and amortization are the future. Each time a drag on the economy like inefficiency, unsustainability or rent seekers are innovated around, the truth that sustainability is cheaper eventually proves itself in their absence.

Even if some of these clever experiments cost 10 times more than the market rate at first, it will click for people that maybe they can lower their own energy usage by half through minor lifestyle changes (whose side effects include greater health and happiness), and drop that by half again with more efficient devices. So most people can get down to 1/4 of their current usage for next to nothing essentially, and now we're only talking a factor of 2.5 times more expensive to go from an unsustainable to a sustainable society. Then if we live with that liberated mindset long enough, the Moore’s law of alternative energy takes care of the discrepancy in a matter of decades. This is already happening and probably unstoppable at this point except through excessive lobbying and fast tracking, which we are seeing as well.
If your employer no longer has a reasonable schedule and workload and expectations, it's time to consider moving on.
Future (present?) of the wearables??
(a) I live just off the corner of Chicago and Austin, on a block with section 8 housing, minority-white, middle-upper-middle class. Any race, income, or crime map of Chicago should clarify what's interesting about those cross-streets. Tell me more about race and class relationships in big American cities?

(b) Your second sentence rebuts an argument I didn't make, and in fact overtly rejected. Nobody who pays any attention to the US would argue that race and class aren't tied together in the US. I certainly didn't.

(c) Ferguson and Park Slope are outliers in exactly the way I spelled out in my post. If you'd like to debate the point, I'm happy to debate it with you, but you're going to have to be more specific. As it stands, your current argument is essentially "Ferguson and Park Slope aren't outliers because the sky is blue and people have ten fingers and ten toes in both locations".

(d) I'd guess we have about 10 minutes to discuss this post before it's (thankfully) flagged off the site.
This is very interesting. I have always felt that having a language that has immutable constructs translates very well into a hardware description language. This is because most of the hardware modules are immutable, except for state machines, which can be modelled using state monads(or something similar).

Considering the hardware tooling right now, I would love to see a language with more abstractions than verilog or vhdl. I would love to see programming languages, that just don't compile to system verilog / VHDL, but can directly move to synthesizing step. I have worked with Bluespec and I don't see that as the successor.

I would say, a language like haskell(or a derivative) can map to a hardware really well, and this is a very good attempt.
Please pursue it / turn it into a product, so that hacking on hardware(a FPGA) is much more easier and beautiful.
Very good point. Plus even if the marginal cost is lower than a dedicated solar facility, we don't necessarily have that luxury. We do if we want just 5% sustainable energy, not a problem. But if we want 99% sustainable energy, surface area is a very tricky challenge [0] and so it'd be a matter of the one and the other, instead of the one or the other.

[0] https://www.youtube.com/watch?v=GFosQtEqzSE
Bitwise operations don't produce Numbers (f64), but signed integers (i32).
Actually, what you get when referencing x.test in Python is a bound method:

>>> foo.test
<unbound method foo.test>
>>> x.test
<bound method foo.test of <__main__.foo instance at 0xf74d68ac>>
>>> z = x.test
>>> z(123)
<__main__.foo instance at 0xf74d68ac> 123

I really like this behavior in Python. Unfortunately, JavaScript does not behave the same way, as you see in the last couple of lines in your example. You can however get the same result by manually binding the method to the object:

z = x.test.bind(x)
// z is: function () { [native code] }
z(123)
// foo {test: function} 123
People are lazy and we took legacy complexity as granted. Time evolves and rarely any problem looks the same. If for no other values, having a second (and third and beyond) look at legacy complexity will worth all the attention.
The enthalpy of fusion for water is 335 J/g. The specific heat capacity of ice at -10C is 2.1 J/(gK). So the major part in melting the water isn't heating it until it melts - it is the melting itself that is expensive.

That said, I do see some value in solar ways in the space savings.
"As always, on the day Obama gave his speech in the Bronx, there were ten black service personnel in black "Just Salad" t-shirts. This time, however, I was surprised to see a white woman in a striped shirt standing among them. Her presence surprised me until I heard what she shouted at the people who were chopping the salad: "Chop, chop, chop, our goal is 45 seconds per customer!" As she spoke, she clapped a rhythm, as if commanding the crew of a Roman galley to row faster."

Indeed, situations in which a majority ethnicity are ordering around a minority happen a lot of the time but bringing it up as an anecdote to end the article makes me wonder if there is a deeper meaning to it. Why was this anecdote chosen out of other conclusions? Does it mean to imply that racism is the reason why people are poor? Or is it making a commentary on how ingrained the social injustices are to our institutions?

Given the context of the rest of the essay, it would seem, to me, it's just a simplistic way of wrapping up a not incredibly enlightening bit of writing.
I haven’t been anyone’s employee for a long time, but that had relatively little to do with technical skill and much more to do with wanting a broader role in the whole “build something useful” process as my experience developed and I became more aware of the non-programming aspects of that process.
"I don't think it's ever a good idea to tell someone they are divorced by reality :)"

My statement was about the claim and about me - I meant to express (colorfully) the distance between the claim and my experience. I did not intend to cast aspersions on the claimant; I certainly apologize if I caused offense, though you seem to have taken it in good spirits regardless :)

Back to the topic at hand:

It sounds like you probably do consider a substantially narrower class of things "type errors" than I do. It is quite rare that I mix up arguments to a function. More commonly I see bad assumptions about the contents of a map, which is often a type error. The most common form of exception I see in Sentry seems to be "NoneType object has no attribute...", which is always a type error.
I'm surprised they didn't mention Leslie Lamport. He apparently started writing "structured proofs" decades ago, and then developed a system TLA+ to do the same thing in a computer.

I am hazy on the details, but I think TLA+ proofs are just checked by brute force, and not with an actual theorem prover? It's for distributed algorithms with a large but finite number of states.

So it's not exactly the same as what's discussed in the article, but it's definitely related. I would appreciate if anyone has any clarification on this point.

https://scholar.google.com/scholar?cluster=14553320809011812...

"A method of writing proofs is described that makes it harder to prove things that are not true. The method, based on hierarchical structuring, is simple and practical. The author's twenty years of experience writing such proofs is discussed."

http://research.microsoft.com/en-us/um/people/lamport/pubs/p...
As a reminder, the 6502 doesn't even have integer multiply or divide.
Julia is an extremely ambitious project -- more so than most other languages being developed now, due to the number of things they're trying to do, and the novelty of Julia relative to previous projects.
I used Julia for a couple of toy projects, but I then started running into various odd bugs in the language and libraries, so I stopped using it.

It's great news for me that they're starting a company, and the core developers will have the opportunity to step up development as part of their livelihood. I hope they hire some full-time developers to iron out all of the kinks.
Actually, custom getters and setters exist in ES5:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guid...

AmpersandJS, for example, implements its observable pattern in this way:

http://ampersandjs.com/learn/state

That said, I don't think the pubsub/rx/observables pattern is the most optimal for UI development, since it still allows for cascading event chains. Modeling all application state as a large data structure that allows for efficient diffing — which nicely mirrors the diffing react does with both it's internal component tree and diffing with the DOM — is a much more straightforward approach. Just re-render your application 60 times a second, like a game engine, and make that process as efficient as possible.
Stupid certificate tricks
I am given to understand that some functionality is not compilable or redistributable. I work in a fairly specialized field (fixed income term structure optimization) and this page is not encouraging (see "cannot be compiled" column):

http://uk.mathworks.com/products/compiler/supported/compiler...

Also, finance is a field ripe for disruption, and if you're going to disrupt, you probably don't want to be doing it by relying on an expensive piece of highly proprietary technology, is my view.
Ellison may be an asshole but

“I was told it stalled in committee and the reason why, we found out a few weeks ago, is because Oracle uses it to go after their competitors”

Is not the slightest bit specific about what, if anything, he actually did. Some actual journalism would be helpful here.
Nope.

Pure math people are significantly worse devs in their first jobs. Significantly. Why? They just don't have the language or training so you can't really give direction that assumes anything. And interns are raw enough anyway, this lack of shared language hurts.

My experience is based off of interns though. I'm sure given 2-5 years, it will depend on the person/continuous learning, blah blah rather than what courses they took in college.

Now, another aspect of the question seems to be: are pure math grads smarter than cs grads?

Nope again. Put a pure math and CS guy in the room together and I'm sure either could flummox the other with arcane jargon/an exercise. We choose what to do in college based on our interests at that time rather than only basic ability. I have CS, Stats, and Math degrees from college and I didn't notice any difference in raw mental horse power or work ethic or work load amongst those 3 majors.

Aside: there was a marked difference in work load when comparing my engineering/math/stat classes and my econ minor classes though: weekly assignments for econ took 30 mins before class whereas cs/math assignments easily took a whole day or two of the week each.

Aside2: And no, you can't generally say philosophy or physics grads make better software devs too.
> - It requires a central registry of all the sockets you need, for all your services. Like a Microsoft Windows registry. It's a database of everything that's running on your system; this defeats the essence of modularity.

So central repositories are now a tool of the devil, no matter what? If anything, this seems like a great win for modularity: from the outside you can interact with it as if it was all part of one whole, while the actual implementation can be replaced piecemeal without shattering the illusion.

> - systemd claims this makes the boot time faster: since all the sockets are already created, every service can connect to every other one and start at the same time. But this is not true, or true to a very little extent: if service A depends on service B and they start in parallel, A will only be able to run as long as it writes to B (and the buffer is not full); as soon as it needs to read from B, it will hang until B is up and capable of writing to A. Parallel start-up of services via pre-opened sockets is only able to perform the first writes in parallel; contrary to what Lennart says, this is not where you gain the most booting time. You gain a little time, for a major decrease in reliability.

Looks like he's misunderstood the point of parallel boot. The aim isn't to make A+B, where B depends on A, boot quicker. The big win is that you can now safely also start C at the same time, which is from a different dependency tree.
Laws named after people are notorious for being abused to a political end that said person may not have been totally for.

May I ask what HN's opinion on Aaron's Law is?