Slashdot stories can be listened to in audio form via an RSS feed, as read by our own robotic overlord.

 



Forgot your password?
typodupeerror

Comment: Re:Wildly premature question (Score 1) 81

by Bruce Perens (#48620117) Attached to: SpaceX To Attempt Falcon 9 Landing On Autonomous Spaceport Drone Ship

If we look at jet aircraft, wear depends on the airframe and the engines, and the airframe seems to be the number of pressurize/depressurize cycles as well as the running hours. Engines get swapped out routinely but when the airframe has enough stress it's time to retire the aircraft lest it suffer catastrophic failure. Rockets are different in scale (much greater stresses) but we can expect the failure points due to age to be those two, with the addition of one main rocket-specific failure point: cryogenic tanks.

How long each will be reliable can be established using ground-based environmental testing. Nobody has the numbers for Falcon 9R yet.

Weight vs. reusable life will become a design decision in rocket design.

Comment: Re:It's required (Score 5, Insightful) 170

by jc42 (#48613591) Attached to: Verizon "End-to-End" Encrypted Calling Includes Law Enforcement Backdoor

Your indignation should not be directed at Verizon - it should be directed at Washington, DC.

A fun part of this is that the government employees at ARPA back in the 1960s explained it all to us. They firmly rejected building any sort of encryption into the network itself, on the grounds that such software would always be controlled by the "middlemen" who supplied the physical connectivity, and they would always build what we now call backdoors into the encryption. They concluded that secure communication between two parties could only be done via encryption that they alone controlled. Any encryption at a lower level was a pure waste of computer time, and shouldn't even be attempted, because it will always be compromised.

This doesn't seem to have gotten through to many people today, though. We hear a lot about how "the Internet" should supply secure, encrypted connections. Sorry; that's never feasible, unless you own and control access to every piece of hardware along the data's route. And the ARPA guys didn't consider that, because that first 'A' stands for "Army", and they wanted a maximally-redundant, "mesh" type network that would be usable in battle conditions. They went with the approach that you use any kind of data equipment that's available, including the enemy's, and you build in sufficient error detection to ensure that the bits get through undamaged,. Then you use encryption that your team knows how to install on their machines and use. And you probably change the encryption software at irregular intervals.

Anyway, the real people to direct your anger at are the PR folks in both industry and government, who keep trying to convince you that they can supply encryption that's secure. Yeah, maybe they can do that, but they never have and they never will. And the odd chance that they've actually done so in some specific case doesn't change this. The next (silent, automatic;-) upgrade will introduce the backdoor.

Unless you have all the code, compile it yourself, and have people who can understand its inner workings, you don't have secure encryption; you have encryption that delivers your text to some unknown third parties. It's the US government's own security folks who explained this to us nearly half a century ago.

Comment: Re:undocumented immigrant (Score 1) 440

by jc42 (#48610663) Attached to: Federal Court Nixes Weeks of Warrantless Video Surveillance

Why does the fourth amendment apply? If he is not a citizen of the US, our laws shouldn't protect him.

So you think tourists shouldn't be protected by US law?

There are a lot of people and companies in the tourism industry who would strongly disagree with you. Not to mention the shipping industry, whose employees often make short visits to places where they aren't citizens, as part of their jobs.

If your suggestion were put into effect, it would be a disaster for a lot of valuable businesses. For that reason, it's not how the law works in the US or in any other country.

Comment: Re:Si. (Score 2) 641

by jc42 (#48569083) Attached to: How Relevant is C in 2014?

"ch" is not a digraph. It is a diphthong.

Well, I'd disagree. It certainly is a digraph, since all that means is that it's two letters that together represent a sound or sounds different from the usual sounds represented by each letter. Since 'c' rarely represents /t/ in English, and 'h' rarely represents what we usually write as 'sh', the sequence 'ch' represents a sound different from "tsh", and thus satisfies the definition of "digraph".

As for diphthong, I can see how one might stretch the term to cover it, but it's a real stretch. The term "diphthong" normally means a sequence of two sounds, typically a sequence that acts like a phoneme in the language. "ch" sorta does this, but the stretchiness comes from the fact that neither of those two sounds are usually represented by 'c' or 'h'. We accept "i" as a diphthong in words like "I" or "time", but it's partly because the phoneme /i/ is one of its two sounds; the initial /a/ is simply not written. Similarly, a "long O" in English typically means an /ou/ or /ow/ sequence, and again the main use of 'o' is included (but the second sound isn't written). The spelling "tsh" would qualify as a trigraph for the main "ch" sound in English, and with that spelling, it would represent a diphthong. But for "ch", it doesn't quite work. It's really an example of the other use of the letter 'h', meaning "a sound sorta like the previous letter's sound, but somewhat different. But this doesn't work, either, because what's the normal sound of 'c'? It's usual either /s/ or /k/, not /t/.

But my main objection is that, in a sense, we're both wrong. English spelling is insane and perverse, and no attempts to apply precise meanings to any written sequence can really be correct. If English had had spelling reforms like all the other European languages have had over the past couple of centuries, we could make meaningful statements about spelling. But this never happened, and any attempt to tie spelling to pronunciation in English is bound to merely make one look foolish. We're not only OT in this thread, but we're arguing about something that can never be analyzed sensibly in English.

My favorite suggestion re this situation (and I've forgotten who first suggested it) is that, since English has become much of the world's de facto international language, the roughly 95% who aren't native speakers should gang up on the English-speaking minority. An international conference for revising English spelling should be formed, or perhaps now it should be an organization built around a web site. That organization should work out a reasonable phonetic writing system for English. The supporting nations should declare that writing system to be their standard for English, with software to transliterate between it and the various "standard" English spellings used by native speakers in different countries. With time, they could overpower the insanity of current English spelling.

But it's clear that this ain't gonna happen any time soon.

(As a native speaker of English, I'd support such an effort. So if some victims of their English-as-a-second-language class want to organize it, I'd be willing to lend at least my moral support. But as a native speaker of English, I'm probably not qualified to organize it. ;-)

Comment: Re:Not even close (Score 2) 772

by jc42 (#48563983) Attached to: CIA Lied Over Brutal Interrogations

The waterboarding done by the Japanese involved putting a hose down peoples throats, filling their stomachs to the bursting point and then hitting the victims stomach with sticks until it actually did burst.

Not even close to the same thing.

But still cruel, ineffective at actually getting reliable information and likely used on people that didn't have the information they sought and we (US citizens) should be fucking ashamed of our government and ourselves by proxy.

Yeah, some of us are. But it's not clear how a mere citizen can do anything effective about it without becoming one of the victims ourselves.

Comment: Re:Si. (Score 3, Funny) 641

by jc42 (#48558195) Attached to: How Relevant is C in 2014?

I have gone out of my way to never use that letter. Notise that at first it kan be a bit diffikult but you get used to it.

In English, pretty much the only "real" use of 'c' rather than 's' or 'k' is in the digraph "ch", which represents a phoneme that has no other standard spelling. However, you kan replase it with "tsh", which produses the same phoneme bekause phonetikally "ch" really is just 't' + 'sh'. So with this tshoise of letters, you kan further approatsh the kommendable goal of replasing an utterly unnesessary English letter with a more phonetikally-korrekt ekwivalent. At the same time, we kan make kwik work of replasing that idiotik 'q' with a sensible replasement.

(Kyue the Mark Twain kwotes on the topik. ;-)

"The identical is equal to itself, since it is different." -- Franco Spisani

Working...