Parallel, disorganized effort scales like O(n); organized effort scales like O(n^2). That's the fundamental benefit (ESR explores it in one of his endless addenda to "The Cathedral and the Bazaar"; Google if you haven't read it).
That's just another way of saying that the duplicated effort you're complaining about turns out not to be as much as the effort you'd spend organizing that many people to prevent duplicated effort. For really huge projects (like a whole OS) it turns out to be better to just throw more people at the problem and let them work randomly. That's the big surprise with open source development.
I'm sad to hear that Christopher Lee's character doesn't appear in either the wasted-of-Isengard sequence or in the Shire-cleanup sequence, but strictly speaking he's not needed in either place.
At Isengard (in the books) we only hear his voice yelling at Wormtongue from within the tower -- his presence is implied but not explicit.
The business with Saruman as Sharkey at the end has always felt a bit ham-handed to me in the books. While it's nice to see that Frodo has some compassion, the main point of the sequence is that the forces of evil have overrun the Shire while the halflings have been away. The hackneyed inclusion of Saruman as petty mastermind is both belittling to him and a jarring shift in his characterization. (I've been told that sequence was actually not JRR's work, but Christopher's -- I'm sure someone will step in and comment!)
In short, despite my emjoyment of Christopher Lee's portrayal, I'm prepared to give Peter the benefit of the doubt. I believe it's possible to cut him out in a way that improves the flow and closure of the main storylines.
The Toyota Prius is NOT designed to get the maximum efficiency. It's designed to get TDI-like efficiency with "all the trimmings" -- it's a quiet, moderately zippy family car with a lot of goodies that would have been factory options a decade ago. The Toyota engineers chose not to go for maximum efficiency (like the Honda Insight), but rather for the efficiency of a jellybean car (like the Geo Metro) in a quiet, comfortable, safe four-door.
There is no "problem" with electric car deployment. The real issue is that everyone underestimates the cost of starting-up a new technology. There will indeed be a "knee" in the development curve, as there has just been with flat-panel screens. Remember, it took from about the mid 1970s until after 2000 before LCDs developed from a curiosity to a significant contender against CRT monitors. That's 25 years of vigorous incremental development to overcome a technology that was only invented 30 years earlier (google Philo Farnsworth). Year after year, Popular Science promised us our flat-panel TVs, and they weren't available. But now, suddenly, everyone's looking a LCDs and you can get huge wall-hanging plasma screens at Costco for essentially the same cost as a back-projection TV.
All of the technologies that are needed for powerful electric cars are relatively new, but they are all present. IGBT transistors, digital controllers, and simple-yet-powerful induction motors are all relatively new but are deployed in production hybrid cars. The big hole (still) is the actual cost of the batteries, as you point out.
The efficiency argument you make is a canard, for reasons that others have hashed out elsewhere in the thread.
But... the energy density is not "maxed out". Lead-acid cells suck, yes. But lithium does much better than lead-acid (while, unlike Nickel-MH cells, being made of cheap ingredients), and fuel cells with hydrated metallic storage will do much better than that. Metal hydrates can have hydrogen energy densities comparable to gasoline, and significantly better if you factor in the higher efficiency of a fuel cell system compared to a combustion engine.
Like flat-panel screens, electric cars will have their day, and we won't go back.
(I used to operate a nuclear reactor, so I have some idea what I'm talking about here).
I'm a bit skeptical about the reflector mechanism: certainly, it makes sense to use a neutron reflector to modulate reactor output. But the business about "if the sleeve moves too fast, then the reactor's lifespan is simply shorted" doesn't make any sense to me.
The lifetime of most reactors is determined by the buildup of "poisons" (neutron-absorbing waste products) in the fuel, which is why reprocessing plants work so well: unlike a coal plant, a nuclear plant generally doesn't get more than a small fraction of the available energy out of its fuel, so you can chemically repair the fuel and use it again.
But the buildup of poisons in the fuel is dependent on the total amount of energy released so far. So moving the reflector too fast should either (A) produce more heat or (B) not affect the lifetime of the core very much. Toshiba seems to be claiming (not-A) and (not-B), which doesn't jive (prima facie) with reactor physics.
A dollar a watt isn't bad -- even if you factor in the extra two dollars you need for decommissioning. Solar in bulk costs three or four US dollars a watt...
I don't particularly like that style either, but I think it's a patch to the pervasive problem that people would register one machine for support and then use the support on a cluster of many machines. "What a coincidence -- the one that failed just happens to be the one we're paying to support... again!"
No, I'm only saying that the publicity photos were pretty obviously retouched. I haven't been to the Mojave Desert since 2001. I just visited the Scaled Composites site, and the pictures in question are no longer there (of course).
It's not an important enough issue to me to dig up the originals -- but, er, "the truth is out there" or something like that.
Actually, no, I was the one who pointed out the photoshopping jobs. I'm too lazy to look up the previous Slashdot article, but the publicity photos on their website were heavily retouched with photoshop. In one case, the SS1 was parked under WK1 (on its own landing gear), and someone had "added" engine cowlings (on WK1) and a mating section between the two. The landing gear supporting SS1 had been clumsily photoshopped out. "Clumsily" because its shadow remained in the picture. Several of the other images had rocket nozzles edited in using a soft-edged gradient fill.
Rutan's team has certainly been making good progress and of course they have been flying and such. But they've demonstrated that they're willing to stretch the truth when it comes to media relations.
I'm pretty impressed with Carmack's project. Rutan is certainly making good progress, but Carmack is focusing on the low-budget essentials: what works, what doesn't. It's the ultimate tinkerer's machine, and he's allowing everyone to see every step. It's fabulous.
When Scaled Composites released their first publicity shots of their two hulls, they were just that -- hulls. No rocket engine, no mating assembly, no jet engines even. But they carefully photoshopped the images (see previous Slashdot coverage) to make it appear that they were farther along than they were at the time.
Carmack doesn't do that. You hear the gritty details of every setback and every afternoon spent monkeying around with the engine. That's a totally new way of communicating with the public (at least for an aerospace development program) and it's exciting and powerful: as with open source programming, it opens up all of their techniques to anyone who cares to listen. Sure the product may be funny-looking and awkward, especially at first, but then so did our favorite open-source operating system.
Oddly enough, aerodynamic stability is pretty easy to assess. It's all about location of the CG and location of the center of aerodynamic force. Because both of those things are (approximately) scale independent, you can test stability with a small model and scale up.
Active control systems were built in the 1930s by the Germans, and successfully used (on V-2's) to direct missiles from Germany to the capital of England.
Rocket science just isn't, er, rocket science these days. Building robust, real-time control systems isn't easy but neither is it especially hard: a $1k laptop running Perl has plenty of power to do the job, and there are oodles of textbooks and expositions on control theory. Sub-millisecond updating is a canard, too -- more like 50-500 milliseconds is all that's needed. (Hint: you can't adjust your pointing faster than the fundamental note that your rocket makes when struck with a hammer -- at higher frequencies it acts like it's made of rubber).
Over the past year, my wife and I complained ever more vociferously about sprint PCS service -- I've had it for six years now, ever since they phased out Sprint Spectrum, and while it has been pretty good up until recently, we found that the service has degraded slowly but surely in our area. At one point we averaged less than four minutes of airtime between dropped calls at our house.
We must've spent a total of about 10 hours on the phone with Sprint service over the months. About the only thing that's been keeping us with Sprint is the lack of number portability -- we've been waiting eagerly for the FCC deadline to pass so we could switch to something more useful in our area (like AT&T).
But then, in an unrelated incident, my trusty old phone died (reversed polarity on the charging line, it's a long story). More or less on a whim, I went to the local sprint store and bought a newer Qualcomm phone (my old one was a Qualcomm too), figuring that I could return it when we cancelled the service in a few weeks. But the new phone works much better than the older one!
I'm not sure what the difference between the phones is: either the tech has gotten better or Sprint (and others) are changing the protocol somehow -- but I'm very happy with the service with the newer phone.
That's especially odd, since my wife, my brother-in-law, and I all had different brands of Sprint phone and experienced similar problems -- so it's not just that I had a bum phone, or that a particular brand was affected.
Centrino ain't so bad. I have a Centrino laptop (the VAIO Z1A, too bad it appears to have been discontinued after a lackluster run this spring/summer), and the 2.6.0 kernel supports it well for most things. There are three things not supported: (1) the built-in wireless [which can be replaced -- it's a miniPCI card], (2) actual ACPI sleep modes, (3) shutdown leaves the machine powered up (kernel crashes instead of powering down). Everything else -- screen brightness, all the gizmoes including the losemodem, CPU throttling, wireless over PCMCIA -- seems to work just fine.
Oh, and you can indeed leave it running with the screen closed (though the hardware seems to switch off the screen illumination in that case).
Unless he can prove that he was discriminated against then he is pretty much out of luck.
Uh... if he was fired, and nobody else was, then he was pretty clearly discriminated against. Why the heck doesn't anybody understand what "discrimination" is? (separation according to characteristics of each individual).
Only some forms of discrimination are illegal. The law says words to the effect of "You may not discriminate on the basis of , , or ". That's it.
You're perfectly allowed to discriminate on the basis of how smart people are, or how bad they smell, or whether they understand the language they are trying to use. Just not by race or religion, usually, and even then only in matters of real estate and employment.
Devphaeton, you hit the nail on the head about 2.6.0. Its main advantage over 2.4.x (for this luser anyway) is the smoother multitasking even on a uniprocessor system. I'm running a tweaked 2.6.0-test5 on my laptop, and jobs that would make 2.4.x unusable are barely detectable (from the standpoint of moving the mouse around, typing up slashdot articles, and the like).
Of course, the ACPI support and swsusp doesn't hurt either:-)
Weather prediction is a good example of weakly predictive system: the meteorologist can't tell you 100% precisely whether there will be rain or not; he can only give you predictions.
But, aside from the statistics of how effective they are, meteorology passes two tests that astrology does not: there is a plausible explanation given for why it should work; and the results are falsifiable.
By "Plausible explanation" I don't mean that, er, it sounds OK to me. I mean something very specific. All of the theory of weather prediction is reducible to particular experiments that you can do in the laboratory, to particular pieces of mathematics that you can teach to a non-believer, and/or to particular types of correlated observation you can make and teach readily. The product (a weather prediction) rests on a collection of simpler components that give a clear line of causality between the observations (wind speed in various places, satellite photos, etc.) and the predictions. Astrology does not have this. In fact, individual astrologers are in general not well versed in the theory of planetary motion. For example, few astrologers can tell you the phases of Jupiter's moons or even which constellation contains the Sun at the moment (hint: it's not the corresponding astrological sign). As a result, their product (predictions and explanations) is not plausible, because there is no line of causality linking their observations (presumably, observations of the sky -- though astrologers are not noted for owning telescopes or other observing equipment) and their product.
Finally, weathermen's results are falsifiable. Meteorologists go out of their way to make statements that actually mean something, in the sense that they exclude whole classes of phenomena. When the weather channel predicts sun and instead it's cloudy, you know immediately that the meteorologists screwed up: their predictions didn't apply to the actual weather. The point of the demo I ran in class is that most astrologers go out of their way to make statements that are not falsifiable and hence mean little. If the horoscope that I gave my students were specific and falsifiable, one would expect about 10% of the class to reply that it applied to them. In fact, over 80% of the class felt that it applied well to them, and only 10% of the class felt that it didn't apply to them. That is to say, the astrologer who wrote the horoscope did a piss-poor job of writing predictions or even life summaries that are useful (in the sense of actually meaning something).
Well, Randi may be a showman and out to sell books, but his science is still good. False positives are poorly understood by most folks, but they are just as valid a way of testing predictions as false negatives.
Specificity to a star-sign is a big deal in astrology -- most astrologers will tell you that horoscopes are valid for a particular sign and no other. The demonstration shows that in fact that claim is false.
Randi's genius is in conceiving very simple tests that expose muddied thinking -- and then using those expositions to teach people about critical thinking in general.
You say "Babies and bathwater and all that", as if to say that throwing out the all the predictions of astrology is a bad idea because it throws out the good predictions as well as the bad. The problem with that idea is that there's no way to tell in advance which predictions are which! Even the astrologers don't know. It's like the old saw about advertising budgets: "I know that half my advertising dollars are wasted -- I just don't know which half!".
The problem there is that the ``underlying (presumably cosmic) forces'' that control both the planets and your environment are well understood. They are the familiar, simple forces that you can learn about in physics class.
Trying to understand something as complex as people using a force as simple as gravity is, well, laughable -- it's like trying to debug the Linux kernel using the theory of humours ("It panicked because of an excess of blood! But this patch contains extra phlegm, which should counteract the black bile from browsing slashdot...")
Not long ago I was teaching introductory astronomy to 180 college freshmen, and we did the "James Randi" demonstration. It was almost surprising how well it worked. I browsed to a horoscope site and downloaded horoscopes for everyone. Printed them up in little folding booklets, 12 types, about 4/3 as many as there were students. Asked the students to come get their horoscope and read it secretly.
Then they voted on how well-tailored their horoscopes were. About 80% of the class said that the horoscopes were "perfect" or "very good", with about 10% "good" and only 10% saying "fair" or "poor".
Of course, the kicker is that they all received exactly the same horoscope, I believe an Aquarius reading for early spring 2002.
Even more of course, the site I got them from advertised that "we don't produce generic horoscopes -- we tailor them specifically to your date of birth!"
Probably not "space weather" this time...
on
Telstar 4 is Down
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· Score: 1
It's probably not space weather (unlike the last famous Telstar dropout, T401, which was probably caused by a rather large shock front in the solar wind). The current space weather plots from NOAA don't show any big disturbances (just a minor blip in solar X-ray flux yesterday evening; but nothing in the geomagnetic or ionizing radiation indices).
Also, the
current LASCO movie of the solar corona doesn't show any solar "storms" coming our way in the last few days (they show up as expanding halos all the way around the Sun), although there were several that went off to the side in that period.
The accepted inventor here is Farnsworth. He came up with the electron-tube concept in high school, in 1921. The first working model was six years later -- 1927. He had a nasty patent battle with (sp?) Zworykin, a Russian immigrant who worked for RCA. He won in court but lost in the real world: the U.S. government suspended commercial production of televisions during World War 2, to conserve resources (I believe for making radar units), and by the time the war was over Farnsworth's patent had expired.
Farnsworth, like Tesla, died virtually penniless and unknown.
Slashdot Mirror
That's just another way of saying that the duplicated effort you're complaining about turns out not to be as much as the effort you'd spend organizing that many people to prevent duplicated effort. For really huge projects (like a whole OS) it turns out to be better to just throw more people at the problem and let them work randomly. That's the big surprise with open source development.
...need I say more?
At Isengard (in the books) we only hear his voice yelling at Wormtongue from within the tower -- his presence is implied but not explicit.
The business with Saruman as Sharkey at the end has always felt a bit ham-handed to me in the books. While it's nice to see that Frodo has some compassion, the main point of the sequence is that the forces of evil have overrun the Shire while the halflings have been away. The hackneyed inclusion of Saruman as petty mastermind is both belittling to him and a jarring shift in his characterization. (I've been told that sequence was actually not JRR's work, but Christopher's -- I'm sure someone will step in and comment!)
In short, despite my emjoyment of Christopher Lee's portrayal, I'm prepared to give Peter the benefit of the doubt. I believe it's possible to cut him out in a way that improves the flow and closure of the main storylines.
The Toyota Prius is NOT designed to get the maximum efficiency. It's designed to get TDI-like efficiency with "all the trimmings" -- it's a quiet, moderately zippy family car with a lot of goodies that would have been factory options a decade ago. The Toyota engineers chose not to go for maximum efficiency (like the Honda Insight), but rather for the efficiency of a jellybean car (like the Geo Metro) in a quiet, comfortable, safe four-door.
All of the technologies that are needed for powerful electric cars are relatively new, but they are all present. IGBT transistors, digital controllers, and simple-yet-powerful induction motors are all relatively new but are deployed in production hybrid cars. The big hole (still) is the actual cost of the batteries, as you point out.
The efficiency argument you make is a canard, for reasons that others have hashed out elsewhere in the thread.
But
Like flat-panel screens, electric cars will have their day, and we won't go back.
(I used to operate a nuclear reactor, so I have some idea what I'm talking about here).
I'm a bit skeptical about the reflector mechanism: certainly, it makes sense to use a neutron reflector to modulate reactor output. But the business about "if the sleeve moves too fast, then the reactor's lifespan is simply shorted" doesn't make any sense to me.
The lifetime of most reactors is determined by the buildup of "poisons" (neutron-absorbing waste products) in the fuel, which is why reprocessing plants work so well: unlike a coal plant, a nuclear plant generally doesn't get more than a small fraction of the available energy out of its fuel, so you can chemically repair the fuel and use it again.
But the buildup of poisons in the fuel is dependent on the total amount of energy released so far. So moving the reflector too fast should either (A) produce more heat or (B) not affect the lifetime of the core very much. Toshiba seems to be claiming (not-A) and (not-B), which doesn't jive (prima facie) with reactor physics.
A dollar a watt isn't bad -- even if you factor in the extra two dollars you need for decommissioning. Solar in bulk costs three or four US dollars a watt...
I don't particularly like that style either, but I think it's a patch to the pervasive problem that people would register one machine for support and then use the support on a cluster of many machines. "What a coincidence -- the one that failed just happens to be the one we're paying to support ... again!"
It's not an important enough issue to me to dig up the originals -- but, er, "the truth is out there" or something like that.
Rutan's team has certainly been making good progress and of course they have been flying and such. But they've demonstrated that they're willing to stretch the truth when it comes to media relations.
Don't lose that letter of marque, Johnny! Arrrrrr....
When Scaled Composites released their first publicity shots of their two hulls, they were just that -- hulls. No rocket engine, no mating assembly, no jet engines even. But they carefully photoshopped the images (see previous Slashdot coverage) to make it appear that they were farther along than they were at the time.
Carmack doesn't do that. You hear the gritty details of every setback and every afternoon spent monkeying around with the engine. That's a totally new way of communicating with the public (at least for an aerospace development program) and it's exciting and powerful: as with open source programming, it opens up all of their techniques to anyone who cares to listen. Sure the product may be funny-looking and awkward, especially at first, but then so did our favorite open-source operating system.
Active control systems were built in the 1930s by the Germans, and successfully used (on V-2's) to direct missiles from Germany to the capital of England.
Rocket science just isn't, er, rocket science these days. Building robust, real-time control systems isn't easy but neither is it especially hard: a $1k laptop running Perl has plenty of power to do the job, and there are oodles of textbooks and expositions on control theory. Sub-millisecond updating is a canard, too -- more like 50-500 milliseconds is all that's needed. (Hint: you can't adjust your pointing faster than the fundamental note that your rocket makes when struck with a hammer -- at higher frequencies it acts like it's made of rubber).
User friendly configuration has been done.
I'd settle for power management working right.
We must've spent a total of about 10 hours on the phone with Sprint service over the months. About the only thing that's been keeping us with Sprint is the lack of number portability -- we've been waiting eagerly for the FCC deadline to pass so we could switch to something more useful in our area (like AT&T).
But then, in an unrelated incident, my trusty old phone died (reversed polarity on the charging line, it's a long story). More or less on a whim, I went to the local sprint store and bought a newer Qualcomm phone (my old one was a Qualcomm too), figuring that I could return it when we cancelled the service in a few weeks. But the new phone works much better than the older one!
I'm not sure what the difference between the phones is: either the tech has gotten better or Sprint (and others) are changing the protocol somehow -- but I'm very happy with the service with the newer phone.
That's especially odd, since my wife, my brother-in-law, and I all had different brands of Sprint phone and experienced similar problems -- so it's not just that I had a bum phone, or that a particular brand was affected.
(We live in Boulder, Colorado)
Oh, and you can indeed leave it running with the screen closed (though the hardware seems to switch off the screen illumination in that case).
Uh... if he was fired, and nobody else was, then he was pretty clearly discriminated against. Why the heck doesn't anybody understand what "discrimination" is? (separation according to characteristics of each individual).
Only some forms of discrimination are illegal. The law says words to the effect of "You may not discriminate on the basis of , , or ". That's it.
You're perfectly allowed to discriminate on the basis of how smart people are, or how bad they smell, or whether they understand the language they are trying to use. Just not by race or religion, usually, and even then only in matters of real estate and employment.
Devphaeton, you hit the nail on the head about 2.6.0. Its main advantage over 2.4.x (for this luser anyway) is the smoother multitasking even on a uniprocessor system. I'm running a tweaked 2.6.0-test5 on my laptop, and jobs that would make 2.4.x unusable are barely detectable (from the standpoint of moving the mouse around, typing up slashdot articles, and the like).
:-)
Of course, the ACPI support and swsusp doesn't hurt either
But, aside from the statistics of how effective they are, meteorology passes two tests that astrology does not: there is a plausible explanation given for why it should work; and the results are falsifiable.
By "Plausible explanation" I don't mean that, er, it sounds OK to me. I mean something very specific. All of the theory of weather prediction is reducible to particular experiments that you can do in the laboratory, to particular pieces of mathematics that you can teach to a non-believer, and/or to particular types of correlated observation you can make and teach readily. The product (a weather prediction) rests on a collection of simpler components that give a clear line of causality between the observations (wind speed in various places, satellite photos, etc.) and the predictions. Astrology does not have this. In fact, individual astrologers are in general not well versed in the theory of planetary motion. For example, few astrologers can tell you the phases of Jupiter's moons or even which constellation contains the Sun at the moment (hint: it's not the corresponding astrological sign). As a result, their product (predictions and explanations) is not plausible, because there is no line of causality linking their observations (presumably, observations of the sky -- though astrologers are not noted for owning telescopes or other observing equipment) and their product.
Finally, weathermen's results are falsifiable. Meteorologists go out of their way to make statements that actually mean something, in the sense that they exclude whole classes of phenomena. When the weather channel predicts sun and instead it's cloudy, you know immediately that the meteorologists screwed up: their predictions didn't apply to the actual weather. The point of the demo I ran in class is that most astrologers go out of their way to make statements that are not falsifiable and hence mean little. If the horoscope that I gave my students were specific and falsifiable, one would expect about 10% of the class to reply that it applied to them. In fact, over 80% of the class felt that it applied well to them, and only 10% of the class felt that it didn't apply to them. That is to say, the astrologer who wrote the horoscope did a piss-poor job of writing predictions or even life summaries that are useful (in the sense of actually meaning something).
Specificity to a star-sign is a big deal in astrology -- most astrologers will tell you that horoscopes are valid for a particular sign and no other. The demonstration shows that in fact that claim is false.
Randi's genius is in conceiving very simple tests that expose muddied thinking -- and then using those expositions to teach people about critical thinking in general.
You say "Babies and bathwater and all that", as if to say that throwing out the all the predictions of astrology is a bad idea because it throws out the good predictions as well as the bad. The problem with that idea is that there's no way to tell in advance which predictions are which! Even the astrologers don't know. It's like the old saw about advertising budgets: "I know that half my advertising dollars are wasted -- I just don't know which half!".
Trying to understand something as complex as people using a force as simple as gravity is, well, laughable -- it's like trying to debug the Linux kernel using the theory of humours ("It panicked because of an excess of blood! But this patch contains extra phlegm, which should counteract the black bile from browsing slashdot...")
Then they voted on how well-tailored their horoscopes were. About 80% of the class said that the horoscopes were "perfect" or "very good", with about 10% "good" and only 10% saying "fair" or "poor".
Of course, the kicker is that they all received exactly the same horoscope, I believe an Aquarius reading for early spring 2002.
Even more of course, the site I got them from advertised that "we don't produce generic horoscopes -- we tailor them specifically to your date of birth!"
I would, but I already posted to this thread.
Also, the current LASCO movie of the solar corona doesn't show any solar "storms" coming our way in the last few days (they show up as expanding halos all the way around the Sun), although there were several that went off to the side in that period.
Farnsworth, like Tesla, died virtually penniless and unknown.