camccann

The number of witnesses may be exaggerated, how much of the attack any given witness saw is probably exaggerated, and the extent to which any of those witnesses could have plausibly realized the severity of the attack is likely exaggerated.

(...) no witness saw the entire sequence of events. Most only heard portions of the incident without realizing its seriousness, a few saw only small portions of the initial assault, and no witnesses directly saw the final attack and rape in an exterior hallway (...) Additionally, after the initial attack punctured her lungs (...) it is unlikely that she was able to scream at any volume."

Not exactly a happy story either way, but nowhere near as bad as "a group of people watching a woman be raped and killed and choosing not to do anything", just your ordinary, garden-variety, this-is-clearly-someone-else's-problem bystander effect.

Does this negatively impact the incident's use as an example? Not really.

More importantly, it doesn't change the fact that the correct reaction to the incident is clearly to don a mysterious mask and become a costumed, crime-fighting vigilante.

Not that they don't have standards--I'm sure they're very careful not to release anything that would reveal private information about specific, identifiable users.

Other than that, yeah. Those guys pretty much do statistics for the lulz. I would not be surprised at all if wzdd turns out to have been correct...

The author argues that males have a wider intelligence distribution, and so though they are equally as intelligent as females on average, there are more of them at the far right end of the scale.

At both ends, actually, but that's largely irrelevant to the argument. Actually, I think the idea is that males have higher variance on a variety of attributes, due to higher expected utility, in an evolutionary sense, from trying high-risk, high-reward strategies (standard disclaimer: do not anthropomorphize evolution, do not equate evolutionary goals with conscious goals).

But there's a link here he never established, unless I missed it. Is it really true that the brightest of the bright go into STEM?

That's not necessary--only that success in STEM fields is more strongly correlated with intelligence than with unspecified other attributes. It doesn't matter what very smart people in general do; only that higher intelligence confers an advantage. Intra-field competition will take it from there.

It is not, I think, controversial that intelligence correlates with success in STEM fields, seeing as it correlates with success (to some degree) in almost every area of life, but as always, the details are complicated.

What if we established that the intelligence of people who go into STEM is on the right side of the distribution, but not the far right? Then there would be as many females as males at that intelligence level.

Not necessarily--that depends on the shape of all three intelligence distributions (both sexes, and STEM fields).

That said, though, the whole article was basically fluff--lots of raising questions, not much in the way of relevant research, and virtually nothing in the way of concrete predictions or testable hypotheses. Now, as far as I know, there is some established research behind the "wider variance" idea... but to be honest the article raises all kinds of red flags; it feels like something written by picking a conclusion, then looking for science-y-sounding things to support it.

While it would be nice to imagine something like this catching on, somehow I suspect that any language whose reference manual gives a specification of semantics using sequent calculus before discussing the standard libraries is unlikely to gain much use.

Fast, expressive, flexible, with static analysis that can prevent entire classes of common bugs? That sounds great! Oh wait, no, it uses words that sound like math, obviously that makes it unsuitable for the real world. Sigh.

You don't get infinite acceleration from one velocity difference. End of story.

Given a steady source of energy, you can accelerate as much as you like, up to the limit of losses due to friction. What do you think is going to prevent that? More energy, more acceleration.

And again, remember that the ability to extract energy from the velocity difference is independent of the vehicle's speed. The acceleration isn't infinite of course, because the energy has to come from somewhere--but so long as the velocity difference between the media persists, energy can be extracted. In this case, that means "as long as the wind is blowing", since the energy to move a lightweight vehicle around isn't going to make much of a difference compared to the total energy in the atmosphere.

Funny; demands to make a bet seem pretty common around this whole matter.

Demands? More like an offer of free money, wouldn't you say? I mean, you'd just have to prove that their clearly impossible machine indeed doesn't work, right?

Arbitrary magic acceleration

...in other words, either you didn't actually read the explanations or you didn't understand them. The energy is being extracted from a velocity difference between two media. And no, tacking works on exactly the same principles in order to sail upwind. Some manner of mechanical linkage decelerates one or both media with respect to the other, extracting usable energy. In the case of a boat it's the combination of the keel and sail; for this vehicle, it's clever fixed gearing between the fan and wheels. In either case, the velocity of the vehicle relative to either medium is nearly irrelevant.

Check back on this story in months and years and see whether it pans out.

The idea behind this vehicle has been floating around the internet for at least three years, by the way.

If you're really so confident that you're correct, I'm sure one of the "shills" would be happy to make a wager with you, mediated by a neutral third party. What kind of odds would you accept for a wager that the vehicle doesn't work?

"...this is a vehicle that, in still air, would go uphill under its own lack of power..."

No, it wouldn't. The vehicle extracts energy from the velocity difference between the air and the ground, which it converts into forward motion. This is essentially the same mechanism used by sailboats tacking against the wind, and despite being counterintuitive at first is well-established. The speed is limited only by gearing and mechanical efficiency--an idealized device could accelerate arbitrarily.

While the Wired link doesn't explain how the device works, the same idea has made the rounds on the internet many times before; links to detailed descriptions were already posted in the comments here, which I assume you didn't bother to read before implying that this is a scam?

"Trying to put skeptics on the defensive"

Sticking with a knee-jerk reaction against something while ignoring further information that supports it gives "skeptics" a bad name.

Hmm. A solid idea, but it's important to contrast it with a less desirable, but superficially similar methodology, namely "Development Driven Development":

1. First, develop some code

2. Think about whether it solved the problem

3. If not, repeat until it does

...which I fear is a rather more common variant.

Glorifying "hard work" as more important than intelligence is a common mistake made by intelligent people when they finally realize that sitting around being intelligent is not, in fact, sufficient to make things happen (this is often surprisingly contrary to expectations formed during schooling).

In my experience, writing simple code often requires more cleverness from the programmer than does writing clever code.

I disagree--we should instead continue what appears to be the current trend, namely, putting 4chan in charge of the national political discourse. This seems likely to substantially increase the amount of honesty, intelligence, and common sense involved in the whole process.

This message paid for by Friends of Longcat.

Hey, environmental destruction isn't something to take lightly. Spewing huge amounts of corrosive chemical pollution into the air as a byproduct of energy generation, irrevocably altering the environment, causing mass extinctions world-wide, all because of--eh? What? Humans? Oh, I thought we were talking about cyanobacteria.

(For details, see: http://en.wikipedia.org/wiki/Oxygen_catastrophe )

Gotta love a page that has a tutorial on "realistic shading" for drawings of 4-D objects.

Well, there's not much to the basic idea--the λ-calculus just is the structure of a cartesian closed category. Exponential objects represent morphisms by objects, a.k.a. first-class and higher-order functions, the equivalence Hom(X * Y -> Z) ~ Hom(X -> Z^Y) is currying, a morphism ((Y^X) * X) -> Y is function application, and so on.

A basic cartesian closed category alone only gets you the simply-typed λ-calculus, though, which isn't much fun. The untyped λ-calculus is of course incoherent from the C-H perspective, since unrestricted recursion[0] gives you Turing-equivalence, which corresponds to an inconsistent logic; a categorical description would probably be easy but I don't think I've seen one.

More expressive typed λ-calculi such as System F are more interesting from a computer science perspective, but I've not been able to find much material discussing them from a logical or categorical perspective. Instead, most mathematicians would jump straight to something like Coquand's Calculus of Constructions[1], which is (if memory serves me) the internal logic of a topos.

Category theory also sees some use in computer science beyond just C-H stuff--for instance, describing recursive data types as fixed points of endofunctors on the category of types. This permits an elegant categorical description of operations on those types--e.g., the "fold" or "reduce" function on lists is represented by an initial F-algebra. The categorical habit of dualizing everything in reach also pays off: the dual of well-founded recursion collapsing structures using an initial F-algebra is productive corecursion building structures using a terminal F-coalgebra, which turns out to be a useful description of non-terminating programs that compute only on demand and then return to an idle state.

Another fun one: Representing data structures algebraically using sum and product types, it turns out there's a meaningful semantics for taking the derivative of the type--you get the original type with any one value missing, plus enough information to specify the location of the hole.

There's also something involving a relationship between Kan extensions and the continuation-passing transform but that's really getting beyond my knowledge.

I've also seen stuff about running C-H the other way, and using categorical models of linear logic as a semantics for expressing resource awareness and side effects in a programming language.

If you want to see some of the above in action, the ML family of programming languages are based on typed λ-calculi, and acknowledge mathematical connections a bit more that most other languages. Haskell [2] is a more distant cousin in that family, and of the not-completely-obscure languages it tends to most cheerfully play with concepts from category theory. For instance, take a look at some of the material on this blog: http://comonad.com/reader/category/category-theory/ If nothing else, you can probably dig around from Haskell-related material to find more general stuff.

[0] The best-known implementation for recursion is Y, Curry's fixed-point combinator, written in lambda terms as (λf. (λx. f (x x)) (λx. f (x x))). In a typed setting, if it can be expressed at all, it ends up being equivalent via C-H to a proposition (A -> A) -> A, which permits a proof of any proposition. This makes it easy to see how the Halting problem is closely related to Godel's incompleteness theorem, as any language with a coherent interpretation via C-H will reject some perfectly sensible programs (i.e., is incomplete).

[1] The CoC is also the basis for the proof assistant/programming language Coq. See also the "Lambda Cube" for a taxonomy of orthogonal type system enhancements.

[2] Named for Prof. H. Curry, of course.

I'm not sure if what you're looking for exists--it depends on what angle you're looking to approach it from, for one thing. TAOCP is a classic for certain kinds of rigorous, formal reasoning about algorithms, but it can be a bit intimidating. One of Knuth's famous quotes is "Beware of bugs in the above code; I have only proved it correct, not tried it", if that gives you some idea of his style...

On the other hand, if you want to reconstruct computer science via symbolic logic and very abstract math, variations on Church's lambda calculus (from which most functional programming languages derive) correspond closely to intuitionistic logic/the internal logic of some cartesian closed category. That stuff is liable to give even some mathematicians a headache, though, and it's easy to lose sight of more practical corners of CS that way.

It's a well known principle that, given a brief problem description, the less a software engineer knows about the problem domain, the easier they will judge the solution to be.

Actually, mkramlich specifically said the Republican party's message, which I think most people would agree in regards to. What the Republican party actually does in office, never mind what other parties do, is another matter, and not necessarily related in any meaningful way to aforementioned "message".

Computer Science--as opposed to software engineering, or day-to-day programming in general--is nothing but an odd flavor of applied abstract math. Chances are, you know more CS than most people with CS degrees, since most undergraduate "computer science" programs are actually a mish-mash of software engineering and dumbed-down bits of CS.

C's "types" are just interchangeable methods of interpreting a pile of bits. That's not a strong type system, that's types on the honor system.

Apologies, don't have time to do a proper job of it right now, so here's a quick summary: Complex addition is basic Cartesian vector addition in the complex plane; complex multiplication is combined polar-coordinate rotation/scaling, by adding the two angles and multiplying the magnitudes. The Mandelbrot iteration formula is Z*Z+C, so there are only three transformations: double the angle, apply the scaling factor, and move the point by a fixed offset.

For each point in the graph, fix the distance between it and the origin: that's C. Center a wheel of some sort at the origin, find the angular distance from the point to the positive real line, then rotate the wheel by that amount. The magnitude scaling is the trickiest part, since you're moving it either toward or away from the origin depending on whether it's greater or less than one, and the scaling factor is proportional to the magnitude itself; but I'm pretty sure there's some sort of multiplicative transformation that could be done with an appropriately-placed lever.

So, take the aforementioned contraption, rotate the wheel, adjust the distance, then shift the point by the original offset. Repeat 70 times, or until the distance exceeds the machine's maximum. Mark the point appropriately, and pick a new one. The accuracy would be dubious near the boundary, of course, but it beats doing arithmetic...

Maybe one of these days I'll draw up usable schematics for how it would work. Mechanical computation has a certain charm to it.

There's a well-known quote that says "computer science is no more about computers than astronomy is about telescopes". Often attributed to Dijkstra, but I don't know if there's a reliable source.

Perhaps it is bad form to pick nits in an amusing bit of April Foolery, but as an interesting aside, with a better technique it would take nowhere near nine years to produce manually a 70 iteration 120x120 rendering of the M-set--by avoiding explicit calculation entirely! A geometric interpretation of the path taken by each point gives a simple, easily mechanized transformation, that could be implemented with a system of gears, levers, and other basic mechanisms, plausibly reducing the time necessary to a few seconds per iteration.

It's such a shame that people think that way, after all, it couldn't possibly be the case that a straight man thought that treating a gay man badly was the wrong thing to do.

Or even that someone might just think that a man who did great things for the world being treated so badly that he was driven to suicide was a gross injustice of staggering proportion no matter what stupid reason there was for the mistreatment. It's somewhat depressing that even today who Turing slept with is apparently more significant than anything else about him. Sigh.

Also significant is that cicadas, while numerous, aren't very large. Predator body size tends to be roughly proportional to their prey's body size, and larger animals tend to live longer.

The net result is that the cicada cycle is a bit longer than the expected lifespan of a hypothetical predator, making it even harder for such to evolve.

I don't think anyone would disagree that, in theory, the ideal government is a wise, benevolent dictator. The primary problem, in practice, is finding such a dictator (the secondary problem, of course, being how to get rid of him when he turns out to be insufficiently wise and/or benevolent after all).

Democracy is actually a pretty terrible way to run things; as Churchill said, it is the worst form of government, except for all the others that have been tried so far.

I'm surprised the article didn't say more about the phenomenon of businesses using gargantuan Excel spreadsheets held together with a Escher-like tangle of macros and formulas. As much as the idea makes "real" programmers shudder, it's one of the best examples of otherwise not-particularly-technical people doing some manner of programming to automate their day-to-day tasks.

I question the assumption that there is, in fact, any depth involved in arguments over the merits of socialism-in-general. Or most discussions of economic systems, for that matter.

I was going to say this is one of the saddest things I've ever read.

Approximately 150,000 people died yesterday.

In fact, another dozen or so probably died while you were reading that sentence. If you were in a room with all the people dying at any given moment, you wouldn't even have time to meet their gaze to say "goodbye" fast enough to keep up.

That's a dozen thinking, breathing people, each with their own hopes and fears, memories and regrets. Many with friends and family who loved them deeply; children who'll never again see their mother's smile, wives who'll never again embrace their husband. Scores of people now grieving, and all kinds of friendships ended as each life fades into the night.

But, yeah. Shame about that tree, eh?

I don't mean this as a criticism of you personally; I had the same reaction to the destruction of the tree. It's just an interesting testament to the irrationality of the human emotional response that we feel sad for an unusual tree, but feel little for the immense magnitude of human loss that occurs constantly.

Let me ask, seriously - I've done a lot of looking into it, and I'm at this point firmly convinced that socialism is a bad thing.

Really. Have you defined what is and is not socialism in a rigorous, non-subjective manner? Have you conducted empirical studies? Run computer simulations based on behavioral models? Published detailed quantitative predictions based on your understanding of economics? What objective means would you use to test the proposition "socialism is a bad thing"? What scenarios might someone who disagrees with you consider very likely that you would consider very unlikely?

This idea of being "firmly convinced" regarding a question of economics is quite novel, so I'm curious how you've come to it.

Okay, you missed my point completely, but never mind.

Arguments about terms with lots of emotional content but very ambiguous meanings tend to look more like people cheering for their local sports team more than like a meaningful discussion.