alex-g

My heart bleeds.

This is misleading. With a one-way function, we are interested in making it hard to find any preimage, not just the one you originally thought of. There are lots of functions whose range is small, but where it's easy to find a preimage (eg: take the first 160 bits of input; XOR all 160-bit chunks together; always return 0).

The avalanche effect (referred to in the last sentence) is important as a heuristic. Among other things, it makes it harder to go from an "approximate" preimage to an exact one. If we had f(x) = y, where y is similar to our target y', we shouldn't be able to find x' with f(x') = y' just by looking at the neighborhood of x. But this doesn't rule out more "clever" ways of tweaking x, and it doesn't obviously stop an attacker from deducing some property of x'. So for one-way functions, what we really want to assert is the nonexistence of an algorithm for finding (properties of) preimages, that is any better than just trying lots of new values of x.

Arch has moved on to systemd these days, if that changes anything for you.

See here for example: http://cryptome.org/cia-decrypt.htm

There was a released-but-redacted CIA memo saying, "An Egyptian Islamic Jihad (EIJ) operative told an XXXXXXXX service at the same time..." From analysis of the size and shape of the blob, the missing text could only be "Egyptian".

In fact, a monospace font turns out to be harder for this; with a proportional font, as here, there is more variability in total word length due to the different letter widths, and so a greater ability to reduce the number of possible matches.

At what sort of age do you think people are ready for proof by contradiction? I remember being taught it explicitly at secondary school (in the UK) but we may have seen implicit uses of it earlier. I would imagine that some very young children might find it difficult to remember the train of thought.

It comes down to whether the stuff is perceived as lots of little indistinguishable bits, or a few big chunks. The former category (mass or non-count nouns) includes water, grain (in the sense of a quantity of grain, not lots of kinds of grains), sand, snow, etc. They are not inflected for the plural and do not take numbers - we say "three grains of sand" not "three sands". It's plausible for Lego to work the same way - so "ten pieces of lego", not "ten legos".

Perhaps in these oft-cited days of lego sets that are more like a few big pieces than lots of little pieces, people will start to think differently.

There's a story about a student (in group theory) being asked "Are G and H isomorphic?" and replying "G is isomorphic, but H isn't".

The combination of Latin and Comic Sans is really weird.

I think it was not clear, for a long time, just how divergent Perl 6 would turn out to be. If you look back (way back) at the original RFC process, most people were proposing fairly minor changes to the language; and it was billed as an opportunity to clean up a lot of cruft at a one-time compatibility cost. Rather like Python 3, in fact. But then it bit off more than it could chew, and as you say it is now envisaged as a new language sharing some Perl heritage.

NPR is not run by the government, though it is partially supported by government grants. It's not Voice of America.

This blog article (http://korystamper.wordpress.com/2012/08/07/seeing-cerise-de...) by lexicographer Kory Stamper raises some similar issues about color names in English - how does one define "cerise" or "taupe" in the dictionary, when nobody can agree on what precisely they mean (where to draw the boundary).

There is also the issue of how best to write the definition so that people can actually understand it. Webster's Second and Third New International Dictionaries included color plates (which seems reasonable!) but also gave HSB values in the Second and complex color comparisons in the Third (cerise is "a moderate red slightly darker than claret, slightly lighter than Harvard crimson, very slightly bluer and duller than average strawberry, and bluer and slightly lighter than Turkish red"). For the Learner's Dictionary, though, they used definitions like "green is the color of grass", less precise but probably still having some psychological truth - the color of grass is surely an anchor point for our concept of green.

Many countries, including the USA, do have such programs. The American version is food stamps, paid for out of general taxation and distributed to millions of people in low-income households. It's not as all-encompassing as your suggestion, but then neither is government involvement in healthcare.

It has apparently crossed several minds, because you're certainly not the first one to suggest it. But as someone who's organized more than one conference, I can say that "the best" is not nearly as easy to define as many people think. Of course there are various kinds of technical quality that we can estimate, and trade off against one another, but one also has to consider the overall balance of the event - for example, we don't want too many talks on the same topics, which may result in otherwise-worthy proposals getting bumped.

Moreover, there is a hugely important signalling role in the selection: it is advertising, "here is our community, here's who we are, here are the problems we work on and the cool techniques we use". So the selection also takes into account things like: "people doing X should get to meet people doing Y", "we think more people should work on Z", and so on. Diversity among the speakers is part of this! Just as surely as you wouldn't want a program of people all from the same company - like it or not, the makeup of the speakers does send a message, and part of the responsibility of organizing an event is deciding what that message will be. It's also communicated by all sorts of other things, including the process for soliciting and choosing submissions, details of language and graphic design, etc. All of these things contribute to a general impression of what the community is like.

The claim of "coincidence" in this instance would be a lot more convincing if the procedures and language were there to back it up. I'm not even talking about affirmative action. I only mean that if you want to claim to be meritocratic, you have to do the work, not just cross your fingers.

Oh, absolutely, I just think it's a shame.

This seems to me to be far more useful than user-defined literals (the conflicting feature). At least, I can think of many programs where digit separators would be nice - but for user-defined literals, I don't see them as providing much. We could already make invocations like "pixels(200)" and being able to say "200_pixels" doesn't add much to that, except complicating the parser.

This is a decent start: http://rationalwiki.org/wiki/Freeman

It's a necessary motto.

The alternative would be to wait until you weren't doing anything important, and had nothing important on the horizon - which is when your employer will be thinking of you as a dead weight. If you're a valuable employee, then you'll always be working on something that your employer values. It's far better to move on when you're the star performer and they're sorry to see you go, than when you're the slacker that they can't wait to boot out.

Things look a bit different from the other side of the table, anyway; the original questioner's project is a tricky one but it doesn't sound like it's absolutely critical to the company. If he's not around then they can probably make do with somebody else (maybe a new hire), or just live with the old system. People come and go for all sorts of reasons, and it's the responsibility of management to cope with that. As long as he gives reasonable notice and cooperates with the process then there should be no grounds for hard feelings.

FWIW in ack 2.0 (currently in alpha) this behaviour will be different: it will search all text files by default.

You might like "To Mock a Mockingbird" by Raymond Smullyan. It's a book of logic puzzles with a focus on combinatory logic (a model of computation related to the lambda calculus). Aside from the logic/math/CS nature of the content, the progression of the exercises should help with mathematical-style reasoning in general.

It's not a high overhead. Your string method would have to do basically the same thing as the ipaddress initialization and method call. As a benefit, with ipaddress you don't have to re-parse the string every time you want to manipulate it as an address; and you get a bit of typechecking and documentation from using a specialized class.

> More conservative distributions tread very carefully.

Well, yes, that's what conservative means. You're using stable distros, with older versions of Python, and it sounds from your original post like you're not interested in using newer versions right now. So... what's the problem exactly?

This is a great point, and this isn't just about Twitter but also about many other sites and services that seem to depend on it. It looks like a lot of people have created a distributed system version of dependency hell for themselves, where they rely on a multitude of third parties not to change behaviour or go down. Additionally, in many cases and perhaps perfectly legitimately from a cost-benefit perspective, the envisaged way to recover from this kind of problem is to assume that people can quickly and frantically hack their way out of it at short notice.

Vint Cerf usually wears a three piece suit as well. It's a bit of personal branding, plus he just likes wearing them. More importantly, perhaps, the look helped him in the past when dealing with (D)ARPA, military and congressional types, etc., allowing him to propose radical things. He wouldn't have been able to get away with that unless he looked sober, conservative, and respectful.

Maybe not 'stylish' in the sense of glamorous high fashion, but certainly 'stylish' in the sense of having put effort into ones own personal style, and consistently dressing that way. So 'stylish' as opposed to slobbish, slovenly, careless, not as opposed to simple, everyday, cheap, downmarket.

I'm sure MPs will be happy to let us know whether they themselves have obtained a porn license.

The police (etc.) are likely to assume, though, that it does serve explosions - like in Boston in 2007. All the more so if the devices are placed on bridges, transmission towers, large buildings, public transport vehicles, etc.

If you are refused entry to the US, they take a statement and give you a copy. It looks like this is that statement.

The author, Virginia Vassilevska Williams, is married to Ryan Williams, who last year proved a major result in circuit complexity lower bounds (NEXP is not contained in ACC0). It's interesting to see that both of them are making important discoveries, in different areas of computational complexity.

Are you also going to fix the assertion that matrices form a group under multiplication? (They don't: not all matrices have inverses. The general linear group is what you are probably looking for.) It's a bit embarrassing that of your three examples of groups, only one is actually a group...