A lot of people have been saying that light only goes at c in a vacuum. This isn't quite right.
Light goes always at c, period. When it goes through a solid, a better metaphor is that it has to slalom around the atoms in the solid. Of course due to QM it's really more like that Charles Addams cartoon with a ski track leading up to a tree, splitting around, and continuing on. At this point, classical approximations stop making sense, and you have to start talking about amplitudes. You can get the Feynman New Zealand videotapes here. It's an excellent but basic and easily understandable introduction to quantum electrodynamics.
In any event, this doesn't seem to be the same mechanism (unless the amplitudes get stuck as if the photon were going in a loop). It appears to be a similar mechanism, as pointed out elsewhere, to glow-in-the-dark paint. Terribly exciting, but not foundation-shattering, unfortunately. It would be a lot of fun if it were.
Another minor wrinkle is that c is very slightly faster than the speed of light in a vacuum, because a vacuum isn't quite empty. Particles come into the vacuum and immediately annihilated each other all the time. You can theoretically get rid of these by putting a vacuum between two plates so close together that these virtual particles can't form.
I'm not sure why you got voted funny, but basically, you're right. From the article:
A light pulse that is brought to a standstill is not destroyed.
The atoms 'remember' it, so the pulse can be regenerated
by changing the intensity of the coupling laser to allow the
atoms to re-emit photons - the particles of which light is
composed.
That's pretty clear, if you understand that "light pulse" isn't quite the same as "light" or "photon." This is, of course, a tremendous scientific and technological accomplishment. In terms of basic physics, though, it's roughly similar to glow-in-the-dark paint, or the behavior of a neon or fluorescent bulb, for that matter. The photon is destroyed, but I presume the amplitudes of the atom get stuck in a state where they are exactly the same as if they were entangled with a photon just like it. So, when you fire a laser into it, you get a result that is exactly the same as if you fired a laser at the atom when the original photon was coming at it, and the interference between the amplitude of the laser and that of the atom therefore produces an amplitude just like the one of the original photon, so you see it. Really, really cool trick, but the trickiness is getting the amplitudes stuck in such a way that they keep so much information, not really in stopping light.
Repetitive stress injuries can be cured or prevented by stretching. I've had problems with these in the past, with the tingling wrists and the numb palms and sometimes actual pain, and that goes away easily.
Carpal Tunnel Syndrome, on the other hand, can't. Some people get it and some people don't. I haven't ever heard of a study that shows that repetitive stress injuries lead to CTS, and I've seen at least one (don't have a ref) that doesn't show any significant correlation of CTS between occupations you'd expect and occupations you wouldn't. Although stress can make CTS hurt more, it doesn't seem to make it be there. This is true of a lot of diseases. Hot peppers don't cause ulcers; in fact, they might help ulcers by promoting mucus production. However, they make stuff hurt more, including ulcers, and might make people think they have ulcers when they really don't.
The trouble is that people confuse CTS and repetitive stress injuries. I assume that this woman has real, diagnosed CTS. In that case, it's just a condition, which responds well to surgery but not much else, and it was probably not caused by her job, but may have been made to hurt more.
In any event, it sounds as if Toyota made reasonable accommodation by switching her to another job. I also don't think it was heartless to put her back; if it really did get better, then it was a repetitive stress injury and not CTS, and that's perfectly appropriate, just like putting someone back on the basketball team after their knee heals. If, on the other hand, she had a diagnosis for CTS at the time, then it may have been heartless or may have been ignorant. However the fact that it took a while for the symptoms to come back is suspicious. With real CTS the pain would start right away, bang! unless there was some other inflammation in the same place that just added to the pain. In any event, the fact that whatever did get better seems to be pretty good evidence that it isn't permanent or long-term and so would not constitute grounds for a lawsuit under the ADA.
The classical example of someone actually standing up to the record companies is Frank Zappa. He discovered that Warner Brothers was pulling one of the standard record company tricks to avoid paying royalties, which involves pressing more copies than they record in the books, typically twice as many. I believe this was with Freak Out, his first album, circa 1965. He sued Warner Brothers and won. Part of the settlement was for him to get his own sublabel Bizarre under Warner/Reprise. Even then, he didn't get completely out from under Warner Brothers' thumb until the mid-to-late 1970's, with the Lather fiasco. After that, he sold records under his own separate Barking Pumpkin label and CD's, at first, under Rykodisc.
I think there are two lessons from this:
The record companies historically have been the largest producers of illegal copies of an artist's work. The practice began with Edison, and if you think it has magically vanished, there is a nice bridge in New York I'd like to sell you. Whenever the RIAA gets all huffy and moralistic, take it with the contents of every salt mine in the state of Utah.
If one of the top ten iconoclasts of the 20th century takes more than a decade to become free of record companies, what hope Mariah Carey?
Perhaps I can help. A few years ago, I ran a team to write a large scientific visualization program called SciAn, which was all object-oriented. We did stuff like this. Although most of the time the calculation was saved in a file that we read, we also did calculations within it, sometimes using distributed objects.
One problem you may have been having is that nearly all O-O books are crappy and ignore the real power of objects. Here's a heuristic: when a book talks more about "classes" than it does about "objects," throw it away. Vigorously. Anyway, here's how we did it, and you can maybe decide how you could do it.
Take the case of a grid. (Please!) Just to be simple, first let's take 2-D. The points may be connected with edges to form either a non-structured grid or a structured grid. A non-structured grid may be triangular, such a grid may also be a Delauney triangulation. Or it may be a structured grid, in which case it might be a rectilinear grid. You might want to have the grid denser near the boundaries, I called these "separable" grids because I couldn't think of a better word. Or the grid might be curvilinear, wrapped around, say, an airfoil.
Immediately, an object structure emerges, fairly cleanly, like this:
This probably isn't the hierarchy that I used, exactly, because we had a lot more different kinds. We had multiple grids linked together, data in separate objects linked to the grids, N-dimensional grids with M-dimensional data, time-dependence, etc. But you get the idea.
Would you want to use a bunch of little objects to implement your Navier-Stokes calculations or whatever? No, of course not. Put them as methods within the object.
Once you do this, the objects make sense. You might have a method to initialize the data and a method to calculate one step in the calculation. Another method might be used to switch between, say, a simple projection integration and second-order Runge-Kutta. Call setReynoldsNumber(double x) and see what happens. You might have a method to construct another grid that contains the gradients. You might have a method that resamples any grid as a regular grid. You might have a method that constructs a Delauney triangulation of a point cloud. You might construct an M-1-dimensional slice from an M-dimensional grid, or return a snapshot of a time-dependent data set. Different implementations of these methods may live at different points in the hierarchy.
At our height, we supported about 20 different file formats for the most diverse kinds of data you can imagine: HDF files, protein structure files, EEG recordings, particle traces, for meteorology, chemistry, quantum chemistry, economics, high-energy physics, QCD, you name it, and internally, all the datasets were in the same kind of object and behaved largely the same. As a joke, I deformed an EEG brain by a mountain terrain field. It took about five minutes.
Alas, the research institute went defunct, and now I have to spend my time writing financial and HR reports. On the other hand, I make a lot more money.
Beyond this, you can think in terms of having multiple objects interact. Nearly all of the big stuff that we did involved interactions between grid, dataset, and visualization objects, but there were many others. Want to run your simulation with an isothermal top instead of an adiabatic one? Don't rewrite the equation solver. Slap an isothermal cap on one face of your grid; it knows to clamp the temperatures at each time step. Or whatever: invent your own. Once you start thinking of these things in terms of objects, there's a lot that can be done.
The guy who said that your problems are too small and specialized to benefit from O-O actually had a point. I'm not saying that they are, of course. But if your mindset is that once you have an array of values then you're totally done and eveything's known and you just throw it at a postprocessing package called Graduate Student 3.0, collect your Nobel prize and retire, then there won't be much use for O-O programming. Alas, I've worked with a lot of scientists who thought this way. However, if you work on several problems that are both similar and different, a carefully designed (and redesigned when it doesn't work--don't laugh; it happens) object framework can help you put together something synchronistic that builds up over time and really does save work.
Well, me too. I started building logic circuits when I was 9 using neon bulbs, and then at 10 with DTL and RTL, which was all I could afford. I built my first microcomputer when I was 14 ("built" in the sense of Vector boards and wires and solder and components, not putting a motherboard into a box). At 15 I was writing lessons on PLATO for the Florida functional literacy program. At 16, I wrote a payroll program for a string of hotels. At 17 I wrote my first interpreter in assembly language.
All of this is fine and good and means I was very bright and impressed potential employers, but it would have been ludicrous to consider it the experience of a grizzled veteran. Of course, that was before the unrealistic expectations caused by the dot com fiasco.
The hard part of this or any job is not how to do the technical stuff. I wish it were; life would be a lot easier. Unless you are actually in the armed services, if you're under 22 or so, whether you believe it or not, people have been busting their humps to protect you from the social problems of work, which are the primary thing that "experience" says you can handle. By all means, use your history to impress future employers, but it's a bit early to start claiming discrimination.
In 1953, the National Television System Committee was given the task of implementing a 3:1 compression scheme that could be decoded with a couple of extra vacuum tubes. All the frequencies had been assigned to work with simple black and white televisions. Furthermore, the new color signals had to work with unmodified black and white television sets, a large existing installed base.
The engineering that they did for this was completely brilliant and used the same kind of reasoning about the perceptual properties of the human eye that this product does. It got the job done. And we've been suffering the consequences for fifty years. Anyone who has ever done serious animation for video knows about chroma crawl, notch and comb filters, antialiasing along several different color axes at once, yada yada yada.
With LCD's and decent CRT's, we've been able to get away from most of that, unless you really need to put your signal on a television set. And so now, to save a few bucks on something that is going quickly down in price anyway, we're going to be hobbled for another fifty years because of some "clever" idea? This is progress?
Coins do not cost more to mint than they are worth. When this happens, the government changes the composition of the coins. U.S. cents used to be made of bronze; now they are made of plated zinc. Any leftover bronze cents are worth a little more than a cent in metal content but probably not enough to melt your collection and try to find a buyer. During World War II, cents were made of steel, because copper was in short supply. Nickles used to be mostly nickel; now they contain quite a lot of copper. Quarters and dimes have been sandwiched for some time; they used to be solid.
One of the reasons that none of the proposals to eliminate the U.S. cent has made it is that the U.S. mint makes a 26 million dollar profit every year off of them.
Just drive the 15 kv transformer with an open collector circuit and generate the frequency with software, unless one kick will do it (it might). Put a diode between the emitter and ground if you need some bias.
We need to relearn this lesson - in general, and in the context of the Internet. You guys
could help teach that lesson. Indeed, only technologists have the credibility to speak reason
to this idiot power. But that will require something more than a life of quibbling on
Slashdot. And so far, you've not shown you're up to very much more.
I'm surprised and pleased that more people haven't taken umbrage at this and other comments, because they deserve some clear discussion. I don't take umbrage at all, but I do think that the comment is inaccurate. We may be cynical, but I don't know of another group of people that, pound for pound, does more real politics than geeks. I'm sure that we could do more, and I understand Dr. Lessig's frustration, but the real problem is that there aren't enough of us. Slashdot is the only community of geeks that is big enough even to cause a blip on media radar, and even then they think it's slashdot.com. On a good day, maybe 15% of the articles and responses are substantive and articulate. If all of those people got together and marched on Washington, the throng would be the size of a church tour group. There just aren't enough to make a substantial impact.
It also seems to me that as Dr. Lessig has chosen a career in law and has achieved a position of importance, he will tend to see that culture as the hammer to use on all nails, just as we may naively see a technical solution as the one to follow. He may be certain that the Supreme Court would do the right thing, but I'm not. I think they do a pretty good job, but we must occasionally set the waback machine to 1947, when all of the civil liberties lawyers were certain the Hollywood Ten would prevail. They didn't. They went to jail and their careers were essentially destroyed until some made a partial comeback in the 1970's.
In any event, especially if everything about politics and democracy be true and worthwhile, we need more people. Martin Luther King's speeches were nice, but as the TV commercials show, they wouldn't have meant much without the audience.
What we need is an amplifier. Arguing with other people fills the desire for an amplifier, but it has poor efficiency. There is another kind of amplifier, a way in which a small number of people or one can sway millions: it's called "art."
We need the equivalent of 1984, Uncle Tom's Cabin, Dr. Strangelove, or even M*A*S*H. Vehicles like that are one practical way for one person or a small group of people to present a vision. The only question is how to do it.
Neil Stephenson could do it, I think, as he is an established author with enough crossover appeal who understands the problem. Other authors with the ability seem to be either confined to the SF garrett or are not established. These days, it is harder than ever to become established as an author of fiction, and I'm no Neil Stephenson.
Plays don't seem fertile. In the past, I've seen two technically-oriented plays. Alan Turing, The Enigma was quite good but of course focused on the human drama (as everything ultimately must). Y2K focused on the Evil of those Bad Hackers, but this is not the reason it was bloody awful.
Fine art and sculpture have a limited use. I might imagine an installation that could make participants feel the problems, if there were a sufficiently talented artist. SIGGRAPH has had some pieces that have been promising. However, only a handful of people will ever experience it. Besides, the culture of this kind of art, to paraphrase Fred Brooks, has been given over to art as personal exorcism with little concern for the audience. The first thing most artists put in multimedia is their baby pictures.
Film could do it, but for obvious reasons this will not come out of Hollywood. Dark-horse independent films are not out of the question. Probably like many slashdotters, I carry a complete video studio in a knapsack, but I'm no Stanley Kubrick, either.
Computer games are interesting. I think there's a chance they will develop into an art form as important for the 21st century as movies were for the 20th. Of course the irony of using the computer to deliver a message about freedom through computers is a double-edged sword. However, there are a number of technological and storytelling issues to be addressed; I'm trying to address some of the technological ones with a project to become open source. Even then, some people will want a mindless shooter and that's it, but there at least will be some audience.
It's quite difficult to produce political art that does not come across as vapid polemic, but it may be a worthwhile effort. Supporting auxiliary infrastructure, such as independent press, might be worthwhile as well.
People called it X Windows because X isn't namey enough.
Microsoft's practice of trademarking common words (Windows, Word, Office) was a stroke of genius, because it made people include the Microsoft when speaking about the product. "Hey, Bob, I got Office last week" is a bit misleading.
Perhaps they should rename their company to Lindows and call their produce Operating System.
It's been a few decades since I only had 46 chromosomes. Now I have trillions of them.
When talking about the number of chromosomes to map, the correct number is 24. Once you've mapped one of an autosome pair, you have the map for the other one, too.
The artist formerly known as "the artist formerly known as 'Prince'" doesn't seem to do too many benefits, or any for that matter. He didn't do "We Are the World." For those under the age of fifteen, that was a benefit for starving Ethiopia back when they were at war and Somalia had plenty of food. After Somalia went to war and then didn't have any food, people figured out that there wasn't much point in having this kind of benefit.
There's a difference. Of course, Catholicism is a form of the religion called Christianity. However, when one says "a devout Christian," at least in the U.S. and increasingly in the U.K., it carries a connotation of a certain type of person, one who feels compelled to consider Halloween "of Satan" (even though it's one of the earliest Christian holidays), to state that when the Bible mentions "wine" it's really unfermented grape juice, and above all to make every creative work a footnote to the Bible.
In contrast, Catholicism was truly catholic, because it engulfed and incorporated all of the myths of the cultures it touched. Tolkien saw no conflict at all between being a devout Catholic and being fascinated by the mythology of various places in Europe. He referred to the world in LOTR and The Silmarilion as "sub-creation" and didn't think it conflicted with his religion at all. He asserted more than once that Middle-Earth was the Mediterranean, only very long ago.
Tolkien attempted to convert C.S. Lewis to Catholicism and was by all accounts really ticked off when it didn't work, and Lewis instead adopted something much more in line with the connotations with "devout Christian." Hence The Lion, the Witch, and the Wardrobe, which is the sort of blatant Christian allegory that such people like. Tolkien himself said he detested allegory, although he wrote a little allegory in his youth. He would certainly have considered the assertion that Gandalf was somehow "really" an angel to be absurd and simplistic, especially as the name, borrowing from a pastiche of Northern European languages, means "wizard-elf."
Do many of Tolkien's ideas parallel stories that some call "Christian?" Of course they do, just as they parallel similar stories in just about every culture on the planet. What Tolkien wrote made use of what might be called "archtypes." These stories are basic stories that human beings tell because they are human beings. To say that Gollum was really Coyote is just as accurate and just as silly as to say that Gandalf was really an angel. The value of an archetypal story is in the telling, not the plot, and Tolkien told it very well.
When modern apologists make these assertions, they're dealing with their own internal conflicts, not Tolkien's.
I'm not sure why your posting was rated as "funny," because it's right on the money.
Take my mother. (Please! No, not really, but I couldn't resist.) A few years back, she wanted a computer. I, being the evil scum that I am, concluded that she would do better on the Mac than on Windows 95. I was right. She's had a couple of PowerBooks. She does a lot. She uses email (not through AOL), can get to the web, does finances on Quicken, writes up test papers and letters, manages addresses, and uses the spreadsheet. She is, if anything, above average as a home user. Every time I visit her, she has questions for me, usually trivial matters, and she's very afraid of making changes. (I bought her a Palm, and she was afraid to synchronize it, because she didn't want to "break anything.")
So, a few months ago she calls to say that some of her games aren't working. A conversation like the following ensues:
I: What changed?
She: I had to upgrade Quicken.
I: Just Quicken? Was there anything else?
She: Yeah, I had to get another number.
I: Another number?
She: Yeah, wait a minute. Here it is. 9.1.
I: You installed a major operating system upgrade without calling me first? That can cause a lot of stuff to break!
She: That's what I'm finding out.
People who are not geeks or computer scientists simply do not know what an operating system is. A minority of them know the phrase "operating system," but it has no more intrinsic meaning to them than "geegaw" or "rang deedio." If they know at all about it, they just know that it has to be there and has to work.
Nor should they, in an ideal world. The whole role of an operating system is to facilitate use of the computer and not get in the way. In the user model the operating system is the computer is the genie behind the screen. When they buy a computer, they buy a computer, and everything they get in the box that says "computer" is the computer. They may understand keyboard, monitor, and mouse as parts, but they don't understand, at all, that the OS is a fungible part of the system. There may be a disc, but they ignore it until something breaks.
The same thing is true of user interfaces. Well-meaning people like Jef Raskin and Donald Norman, as well as not-so-well-meaning people like Alan Cooper have been advocating for clean user interfaces that are invisible to the user for years. They're right, from a technical standpoint. They're all of them totally wrong when they try to explain why user interfaces are bad or how to make them better. The reason that user interfaces are not as good as they are is that the more invisible a component is, the less people are even aware of it when making purchase decisions. As a result, while really terrible user interfaces may result in some bad word-of-mouth, really good interfaces also suffer, because by definition, most people don't perceive them as elements. Beyond a certain level of frustration, market forces don't work on user interfaces and may even work against good ones, because mediocre interfaces have more visible features.
Many people confuse the Heisenberg Uncertainty Principle with quantum entanglement. They're both part of QM, but they aren't the same view of the universe. You could be picky and say that the Uncertainty Principle is an obvious result of basic quantum principles, but it's also the result of some numbers that describe the way our universe is scaled. Anyway, it doesn't say the same thing in the same way.
Right, and approximation is almost always good enough.
Consider the kind of optimizations that are usually tackled by the simplex method, such as how much of each size shoe or model of computer to make so that you optimize your profits. The simplex method, worst case, is NP. Back in the 1980's, someone in the Soviet Union came up with a guaranteed P solution to those problems which I only vaguely remember (it involved ellipsoids, but that's all I can recall). Did everyone immediately switch? No, because
Cases that aren't P for the simplex method don't seem to come up in the real world anyway.
The simplex method is much easier to write and test
The inputs to the simplex method are usually just guesses anyway, and you can get rid of the excruciatingly rare NP cases by perturbing the inputs
If it's a little off, and you wind up with two pairs of size 12 shoes out of a thousand, who really cares?
The stupidity of the CEO is more of a factor in making profit anyway
So, basically, the simplex method is plenty good enough, so people use it. The same is true of others. There are node-visiting problems that are NP, but you can get very close to optimal with simuated annealing or genetic algorithms, which are simple and converge quickly. Is it really worth saving a teacup of fuel by finding an exact solution, which will be way less than how much variation you get from delays on the taxiway?
It is really nice to have an exact, provable solution to a problem from an aesthetic standpoint. However, a solution that works in practice is usually all that is necessary.
As others have pointed out, factoring large numbers isn't even NP in the first place; it's
just way harder than constructing two large primes. Even that is due to an approximation, an
algorithm that tells you if a number is probably prime.
So, what would happen? We hard-core CS types would be ecstatic, but the rest of the world would mostly just shrug.
Gasoline prices have been remarkably stable for the past quarter of a century. A decent car costs around $15,000, and a gallon of gas is a buck to a buck and a half. When a decent car cost $5000, a gallon of gas cost a buck to a buck and a half. People will drive all around town to save a dime to a quarter on a fill-up. Whatever the source of this odd behavior, reasonable perception of the actual costs of gasoline is not a part of it.
Gasoline is by no means the biggest cost of a car, unless it's a really cheap car that gets really good mileage, like my Neon, and that's gravy. Yet people have, historically, gone out and bought more fuel-efficient cars even when there is no way they could pay for it by increased efficiency.
Nowadays, everybody knows deep down in their brains that gas is dirt-cheap, even if they don't admit it. That's the reason for the lemming-like move to urban assault vehicles.
If U.S. oil is such an octopoid monster with infinite power, how come there's so much paranoia about OPEC and so many oil fields in the U.S. have been shut down? Microsoft may buy products, but they do have some people working on producing new versions. I'm sure that U.S. oil would have loved to keep Texas a major oil-producing state, but they couldn't.
U.S. oil makes money off of reselling, but you'd think that such a supposed conspiratorial monster would have done better than having U.S. gasoline prices be a quarter of what they are in Europe and much of the rest of the world.
Gasoline really is a good fuel. You get a lot of energy from burning it, and it stays where it's put. It doesn't diffuse through containers or require expensive metal hydrides that you have to run hot. It blows up, but there are a lot of things that blow up worse. The power characteristics of internal combustion engines are good, maybe not as good as steam which provides maximum torque when the engine is stalled, but easier to control. If the U.S. auto manufacturers had really wanted to support Big Oil to the exclusion of all else, they wouldn't be wasting their time at all with these basically electric vehicles and would be spending all the money on research into ceramic engines.
All-electric systems are hard to get right.
There are a few all-electric model airplanes, but there has hardly been a massive switch to them. Is the vast, world-crusing model airplane industry part of the conspiracy, or is it possible that chemical systems do have an advantage over electric system if you have to carry your own power source?
You are corect. Pointing out the technical similarities misses the point. A PC is in a completely different cultural category from an entertainment device.
For one thing, the expectation of reliability is much higher for an entertainment device. Companies that put software in televisions are therefore held to a higher standard that those who write software for PC's. Needing to reboot a television set ever is unacceptable. The PC has a culture so accepting of unreliability that any report of any bug or security problem on Slashdot generates a number of replies to the effect of "So what? All software has bugs. Get with the times, luser."
Culturally, building an entertainment center around the PC rather than embedding computers in devices will probably either
Frighten consumers who would correctly believe the system would be less stable, or
Force consumers to accept a lower standard of stability
It's kind of sad that Slashdot linked to the first part of this series rather than waiting for it to finish.
If they did that, there would be bunches of messages chastizing the linker for linking to old news.
Many who have studied Turing's life believe that this book [turing.org.uk] by Hodges is the definitive work of a man
who was arguably a casualty of his lifestyle.
I haven't seen any mention of the fact that there was a play based on this book. I know it ran in London because I saw it there. I think it also ran on Broadway.
the mac api did have a c binding but you had to specify a pascal binding to all your functions
To the extent that this is sort of true, it is still true. Pascal has a different stack convention from the one in C. The convention that Pascal uses was shared by most other languages at the time, but C originated as a system language. C is organized such that functions like printf could take a variable number of parameters using a kludge involving pointing directly to the stack.
However, C and C++ compilers for the Mac all accept the "pascal" keyword, which is included in all the header files for the API. Besides that, you can ignore it, except in the special case where you need to pass a pointer to the API for a callback function. Then you need to declare your function as pascal, too. You have never had to declare all your functions pascal.
Also, the majority of the API calls are not bindings in the strict sense of the word. They use compiler extensions to produce inline traps in the code.
The reason you might be concerned is weather. Large generating plants operate at much higher effeciency but can still affect the local weather significantly. This would affect the local weather several times as much per kilowatt-hour.
It may be that this plant would be too small or Australia is too big to worry about the weather right now. However, one should remember that no method of generating power is without its environmental effects.
I am also skeptical about this greenhouse. It seems to me that you would need an awfully big greenhouse to provide substantial benefit while you're using it to heat air constantly, and it's going to take energy to maintain it. Ever make a greenhouse in high school? It warms up slowly, even when it is sealed.
Sun Microsystems buys one of the three licenses for Office. They put out a version of Office for Linux. However, they also use the expertise that they get from being able legally to examine the source to improve their Star Office compatibility to 100%.
Impossible, you say? There are three licences. I can't think of too many companies that would be interested and have the cash to put up. Sun, IBM, and somebody else. Microsoft is already producting Office for the Macintosh, and it's good. (The Mac development group at Microsoft has a strong maverick culture.)
I think that Sun might just do this out of spite and to shake up Microsoft.
The major advantage to this, however, would be that Microsoft wouldn't be able to rely on its decade-old catch-up techniques for its most popular products. They wouldn't be able to keep the better API calls secret any more.
Slashdot Mirror
A lot of people have been saying that light only goes at c in a vacuum. This isn't quite right.
Light goes always at c, period. When it goes through a solid, a better metaphor is that it has to slalom around the atoms in the solid. Of course due to QM it's really more like that Charles Addams cartoon with a ski track leading up to a tree, splitting around, and continuing on. At this point, classical approximations stop making sense, and you have to start talking about amplitudes. You can get the Feynman New Zealand videotapes here. It's an excellent but basic and easily understandable introduction to quantum electrodynamics.
In any event, this doesn't seem to be the same mechanism (unless the amplitudes get stuck as if the photon were going in a loop). It appears to be a similar mechanism, as pointed out elsewhere, to glow-in-the-dark paint. Terribly exciting, but not foundation-shattering, unfortunately. It would be a lot of fun if it were.
Another minor wrinkle is that c is very slightly faster than the speed of light in a vacuum, because a vacuum isn't quite empty. Particles come into the vacuum and immediately annihilated each other all the time. You can theoretically get rid of these by putting a vacuum between two plates so close together that these virtual particles can't form.
I'm not sure why you got voted funny, but basically, you're right. From the article:
A light pulse that is brought to a standstill is not destroyed. The atoms 'remember' it, so the pulse can be regenerated by changing the intensity of the coupling laser to allow the atoms to re-emit photons - the particles of which light is composed.
That's pretty clear, if you understand that "light pulse" isn't quite the same as "light" or "photon." This is, of course, a tremendous scientific and technological accomplishment. In terms of basic physics, though, it's roughly similar to glow-in-the-dark paint, or the behavior of a neon or fluorescent bulb, for that matter. The photon is destroyed, but I presume the amplitudes of the atom get stuck in a state where they are exactly the same as if they were entangled with a photon just like it. So, when you fire a laser into it, you get a result that is exactly the same as if you fired a laser at the atom when the original photon was coming at it, and the interference between the amplitude of the laser and that of the atom therefore produces an amplitude just like the one of the original photon, so you see it. Really, really cool trick, but the trickiness is getting the amplitudes stuck in such a way that they keep so much information, not really in stopping light.
Repetitive stress injuries can be cured or prevented by stretching. I've had problems with these in the past, with the tingling wrists and the numb palms and sometimes actual pain, and that goes away easily.
Carpal Tunnel Syndrome, on the other hand, can't. Some people get it and some people don't. I haven't ever heard of a study that shows that repetitive stress injuries lead to CTS, and I've seen at least one (don't have a ref) that doesn't show any significant correlation of CTS between occupations you'd expect and occupations you wouldn't. Although stress can make CTS hurt more, it doesn't seem to make it be there. This is true of a lot of diseases. Hot peppers don't cause ulcers; in fact, they might help ulcers by promoting mucus production. However, they make stuff hurt more, including ulcers, and might make people think they have ulcers when they really don't.
The trouble is that people confuse CTS and repetitive stress injuries. I assume that this woman has real, diagnosed CTS. In that case, it's just a condition, which responds well to surgery but not much else, and it was probably not caused by her job, but may have been made to hurt more.
In any event, it sounds as if Toyota made reasonable accommodation by switching her to another job. I also don't think it was heartless to put her back; if it really did get better, then it was a repetitive stress injury and not CTS, and that's perfectly appropriate, just like putting someone back on the basketball team after their knee heals. If, on the other hand, she had a diagnosis for CTS at the time, then it may have been heartless or may have been ignorant. However the fact that it took a while for the symptoms to come back is suspicious. With real CTS the pain would start right away, bang! unless there was some other inflammation in the same place that just added to the pain. In any event, the fact that whatever did get better seems to be pretty good evidence that it isn't permanent or long-term and so would not constitute grounds for a lawsuit under the ADA.
The classical example of someone actually standing up to the record companies is Frank Zappa. He discovered that Warner Brothers was pulling one of the standard record company tricks to avoid paying royalties, which involves pressing more copies than they record in the books, typically twice as many. I believe this was with Freak Out, his first album, circa 1965. He sued Warner Brothers and won. Part of the settlement was for him to get his own sublabel Bizarre under Warner/Reprise. Even then, he didn't get completely out from under Warner Brothers' thumb until the mid-to-late 1970's, with the Lather fiasco. After that, he sold records under his own separate Barking Pumpkin label and CD's, at first, under Rykodisc.
I think there are two lessons from this:
Perhaps I can help. A few years ago, I ran a team to write a large scientific visualization program called SciAn, which was all object-oriented. We did stuff like this. Although most of the time the calculation was saved in a file that we read, we also did calculations within it, sometimes using distributed objects.
One problem you may have been having is that nearly all O-O books are crappy and ignore the real power of objects. Here's a heuristic: when a book talks more about "classes" than it does about "objects," throw it away. Vigorously. Anyway, here's how we did it, and you can maybe decide how you could do it.
Take the case of a grid. (Please!) Just to be simple, first let's take 2-D. The points may be connected with edges to form either a non-structured grid or a structured grid. A non-structured grid may be triangular, such a grid may also be a Delauney triangulation. Or it may be a structured grid, in which case it might be a rectilinear grid. You might want to have the grid denser near the boundaries, I called these "separable" grids because I couldn't think of a better word. Or the grid might be curvilinear, wrapped around, say, an airfoil.
Immediately, an object structure emerges, fairly cleanly, like this:
Grid
Structured Grid
Curvilinear Grid
Rectilinear Grid
Separable Grid
Regular Grid
Non-Structured Grid
Triangular Grid
Delauney Triangulation
This probably isn't the hierarchy that I used, exactly, because we had a lot more different kinds. We had multiple grids linked together, data in separate objects linked to the grids, N-dimensional grids with M-dimensional data, time-dependence, etc. But you get the idea.
Would you want to use a bunch of little objects to implement your Navier-Stokes calculations or whatever? No, of course not. Put them as methods within the object.
Once you do this, the objects make sense. You might have a method to initialize the data and a method to calculate one step in the calculation. Another method might be used to switch between, say, a simple projection integration and second-order Runge-Kutta. Call setReynoldsNumber(double x) and see what happens. You might have a method to construct another grid that contains the gradients. You might have a method that resamples any grid as a regular grid. You might have a method that constructs a Delauney triangulation of a point cloud. You might construct an M-1-dimensional slice from an M-dimensional grid, or return a snapshot of a time-dependent data set. Different implementations of these methods may live at different points in the hierarchy.
At our height, we supported about 20 different file formats for the most diverse kinds of data you can imagine: HDF files, protein structure files, EEG recordings, particle traces, for meteorology, chemistry, quantum chemistry, economics, high-energy physics, QCD, you name it, and internally, all the datasets were in the same kind of object and behaved largely the same. As a joke, I deformed an EEG brain by a mountain terrain field. It took about five minutes.
Alas, the research institute went defunct, and now I have to spend my time writing financial and HR reports. On the other hand, I make a lot more money.
Beyond this, you can think in terms of having multiple objects interact. Nearly all of the big stuff that we did involved interactions between grid, dataset, and visualization objects, but there were many others. Want to run your simulation with an isothermal top instead of an adiabatic one? Don't rewrite the equation solver. Slap an isothermal cap on one face of your grid; it knows to clamp the temperatures at each time step. Or whatever: invent your own. Once you start thinking of these things in terms of objects, there's a lot that can be done.
The guy who said that your problems are too small and specialized to benefit from O-O actually had a point. I'm not saying that they are, of course. But if your mindset is that once you have an array of values then you're totally done and eveything's known and you just throw it at a postprocessing package called Graduate Student 3.0, collect your Nobel prize and retire, then there won't be much use for O-O programming. Alas, I've worked with a lot of scientists who thought this way. However, if you work on several problems that are both similar and different, a carefully designed (and redesigned when it doesn't work--don't laugh; it happens) object framework can help you put together something synchronistic that builds up over time and really does save work.
Is is business, but it isn't quite as you put it. It's more like this:
Well, me too. I started building logic circuits when I was 9 using neon bulbs, and then at 10 with DTL and RTL, which was all I could afford. I built my first microcomputer when I was 14 ("built" in the sense of Vector boards and wires and solder and components, not putting a motherboard into a box). At 15 I was writing lessons on PLATO for the Florida functional literacy program. At 16, I wrote a payroll program for a string of hotels. At 17 I wrote my first interpreter in assembly language.
All of this is fine and good and means I was very bright and impressed potential employers, but it would have been ludicrous to consider it the experience of a grizzled veteran. Of course, that was before the unrealistic expectations caused by the dot com fiasco.
The hard part of this or any job is not how to do the technical stuff. I wish it were; life would be a lot easier. Unless you are actually in the armed services, if you're under 22 or so, whether you believe it or not, people have been busting their humps to protect you from the social problems of work, which are the primary thing that "experience" says you can handle. By all means, use your history to impress future employers, but it's a bit early to start claiming discrimination.
In 1953, the National Television System Committee was given the task of implementing a 3:1 compression scheme that could be decoded with a couple of extra vacuum tubes. All the frequencies had been assigned to work with simple black and white televisions. Furthermore, the new color signals had to work with unmodified black and white television sets, a large existing installed base.
The engineering that they did for this was completely brilliant and used the same kind of reasoning about the perceptual properties of the human eye that this product does. It got the job done. And we've been suffering the consequences for fifty years. Anyone who has ever done serious animation for video knows about chroma crawl, notch and comb filters, antialiasing along several different color axes at once, yada yada yada.
With LCD's and decent CRT's, we've been able to get away from most of that, unless you really need to put your signal on a television set. And so now, to save a few bucks on something that is going quickly down in price anyway, we're going to be hobbled for another fifty years because of some "clever" idea? This is progress?
Coins do not cost more to mint than they are worth. When this happens, the government changes the composition of the coins. U.S. cents used to be made of bronze; now they are made of plated zinc. Any leftover bronze cents are worth a little more than a cent in metal content but probably not enough to melt your collection and try to find a buyer. During World War II, cents were made of steel, because copper was in short supply. Nickles used to be mostly nickel; now they contain quite a lot of copper. Quarters and dimes have been sandwiched for some time; they used to be solid.
One of the reasons that none of the proposals to eliminate the U.S. cent has made it is that the U.S. mint makes a 26 million dollar profit every year off of them.
Just drive the 15 kv transformer with an open collector circuit and generate the frequency with software, unless one kick will do it (it might). Put a diode between the emitter and ground if you need some bias.
We need to relearn this lesson - in general, and in the context of the Internet. You guys could help teach that lesson. Indeed, only technologists have the credibility to speak reason to this idiot power. But that will require something more than a life of quibbling on Slashdot. And so far, you've not shown you're up to very much more.
I'm surprised and pleased that more people haven't taken umbrage at this and other comments, because they deserve some clear discussion. I don't take umbrage at all, but I do think that the comment is inaccurate. We may be cynical, but I don't know of another group of people that, pound for pound, does more real politics than geeks. I'm sure that we could do more, and I understand Dr. Lessig's frustration, but the real problem is that there aren't enough of us. Slashdot is the only community of geeks that is big enough even to cause a blip on media radar, and even then they think it's slashdot.com. On a good day, maybe 15% of the articles and responses are substantive and articulate. If all of those people got together and marched on Washington, the throng would be the size of a church tour group. There just aren't enough to make a substantial impact.
It also seems to me that as Dr. Lessig has chosen a career in law and has achieved a position of importance, he will tend to see that culture as the hammer to use on all nails, just as we may naively see a technical solution as the one to follow. He may be certain that the Supreme Court would do the right thing, but I'm not. I think they do a pretty good job, but we must occasionally set the waback machine to 1947, when all of the civil liberties lawyers were certain the Hollywood Ten would prevail. They didn't. They went to jail and their careers were essentially destroyed until some made a partial comeback in the 1970's.
In any event, especially if everything about politics and democracy be true and worthwhile, we need more people. Martin Luther King's speeches were nice, but as the TV commercials show, they wouldn't have meant much without the audience.
What we need is an amplifier. Arguing with other people fills the desire for an amplifier, but it has poor efficiency. There is another kind of amplifier, a way in which a small number of people or one can sway millions: it's called "art."
We need the equivalent of 1984, Uncle Tom's Cabin, Dr. Strangelove, or even M*A*S*H. Vehicles like that are one practical way for one person or a small group of people to present a vision. The only question is how to do it.
Neil Stephenson could do it, I think, as he is an established author with enough crossover appeal who understands the problem. Other authors with the ability seem to be either confined to the SF garrett or are not established. These days, it is harder than ever to become established as an author of fiction, and I'm no Neil Stephenson.
Plays don't seem fertile. In the past, I've seen two technically-oriented plays. Alan Turing, The Enigma was quite good but of course focused on the human drama (as everything ultimately must). Y2K focused on the Evil of those Bad Hackers, but this is not the reason it was bloody awful.
Fine art and sculpture have a limited use. I might imagine an installation that could make participants feel the problems, if there were a sufficiently talented artist. SIGGRAPH has had some pieces that have been promising. However, only a handful of people will ever experience it. Besides, the culture of this kind of art, to paraphrase Fred Brooks, has been given over to art as personal exorcism with little concern for the audience. The first thing most artists put in multimedia is their baby pictures.
Film could do it, but for obvious reasons this will not come out of Hollywood. Dark-horse independent films are not out of the question. Probably like many slashdotters, I carry a complete video studio in a knapsack, but I'm no Stanley Kubrick, either.
Computer games are interesting. I think there's a chance they will develop into an art form as important for the 21st century as movies were for the 20th. Of course the irony of using the computer to deliver a message about freedom through computers is a double-edged sword. However, there are a number of technological and storytelling issues to be addressed; I'm trying to address some of the technological ones with a project to become open source. Even then, some people will want a mindless shooter and that's it, but there at least will be some audience.
It's quite difficult to produce political art that does not come across as vapid polemic, but it may be a worthwhile effort. Supporting auxiliary infrastructure, such as independent press, might be worthwhile as well.
The last two answers seem exactly the same. There's also a stray right angle bracket in the second which suggests an HTML goof.
People called it X Windows because X isn't namey enough.
Microsoft's practice of trademarking common words (Windows, Word, Office) was a stroke of genius, because it made people include the Microsoft when speaking about the product. "Hey, Bob, I got Office last week" is a bit misleading.
Perhaps they should rename their company to Lindows and call their produce Operating System.
It's been a few decades since I only had 46 chromosomes. Now I have trillions of them.
When talking about the number of chromosomes to map, the correct number is 24. Once you've mapped one of an autosome pair, you have the map for the other one, too.
The artist formerly known as "the artist formerly known as 'Prince'" doesn't seem to do too many benefits, or any for that matter. He didn't do "We Are the World." For those under the age of fifteen, that was a benefit for starving Ethiopia back when they were at war and Somalia had plenty of food. After Somalia went to war and then didn't have any food, people figured out that there wasn't much point in having this kind of benefit.
There's a difference. Of course, Catholicism is a form of the religion called Christianity. However, when one says "a devout Christian," at least in the U.S. and increasingly in the U.K., it carries a connotation of a certain type of person, one who feels compelled to consider Halloween "of Satan" (even though it's one of the earliest Christian holidays), to state that when the Bible mentions "wine" it's really unfermented grape juice, and above all to make every creative work a footnote to the Bible.
In contrast, Catholicism was truly catholic, because it engulfed and incorporated all of the myths of the cultures it touched. Tolkien saw no conflict at all between being a devout Catholic and being fascinated by the mythology of various places in Europe. He referred to the world in LOTR and The Silmarilion as "sub-creation" and didn't think it conflicted with his religion at all. He asserted more than once that Middle-Earth was the Mediterranean, only very long ago.
Tolkien attempted to convert C.S. Lewis to Catholicism and was by all accounts really ticked off when it didn't work, and Lewis instead adopted something much more in line with the connotations with "devout Christian." Hence The Lion, the Witch, and the Wardrobe, which is the sort of blatant Christian allegory that such people like. Tolkien himself said he detested allegory, although he wrote a little allegory in his youth. He would certainly have considered the assertion that Gandalf was somehow "really" an angel to be absurd and simplistic, especially as the name, borrowing from a pastiche of Northern European languages, means "wizard-elf."
Do many of Tolkien's ideas parallel stories that some call "Christian?" Of course they do, just as they parallel similar stories in just about every culture on the planet. What Tolkien wrote made use of what might be called "archtypes." These stories are basic stories that human beings tell because they are human beings. To say that Gollum was really Coyote is just as accurate and just as silly as to say that Gandalf was really an angel. The value of an archetypal story is in the telling, not the plot, and Tolkien told it very well.
When modern apologists make these assertions, they're dealing with their own internal conflicts, not Tolkien's.
I'm not sure why your posting was rated as "funny," because it's right on the money.
Take my mother. (Please! No, not really, but I couldn't resist.) A few years back, she wanted a computer. I, being the evil scum that I am, concluded that she would do better on the Mac than on Windows 95. I was right. She's had a couple of PowerBooks. She does a lot. She uses email (not through AOL), can get to the web, does finances on Quicken, writes up test papers and letters, manages addresses, and uses the spreadsheet. She is, if anything, above average as a home user. Every time I visit her, she has questions for me, usually trivial matters, and she's very afraid of making changes. (I bought her a Palm, and she was afraid to synchronize it, because she didn't want to "break anything.")
So, a few months ago she calls to say that some of her games aren't working. A conversation like the following ensues:
I: What changed?
She: I had to upgrade Quicken.
I: Just Quicken? Was there anything else?
She: Yeah, I had to get another number.
I: Another number?
She: Yeah, wait a minute. Here it is. 9.1.
I: You installed a major operating system upgrade without calling me first? That can cause a lot of stuff to break!
She: That's what I'm finding out.
People who are not geeks or computer scientists simply do not know what an operating system is. A minority of them know the phrase "operating system," but it has no more intrinsic meaning to them than "geegaw" or "rang deedio." If they know at all about it, they just know that it has to be there and has to work.
Nor should they, in an ideal world. The whole role of an operating system is to facilitate use of the computer and not get in the way. In the user model the operating system is the computer is the genie behind the screen. When they buy a computer, they buy a computer, and everything they get in the box that says "computer" is the computer. They may understand keyboard, monitor, and mouse as parts, but they don't understand, at all, that the OS is a fungible part of the system. There may be a disc, but they ignore it until something breaks.
The same thing is true of user interfaces. Well-meaning people like Jef Raskin and Donald Norman, as well as not-so-well-meaning people like Alan Cooper have been advocating for clean user interfaces that are invisible to the user for years. They're right, from a technical standpoint. They're all of them totally wrong when they try to explain why user interfaces are bad or how to make them better. The reason that user interfaces are not as good as they are is that the more invisible a component is, the less people are even aware of it when making purchase decisions. As a result, while really terrible user interfaces may result in some bad word-of-mouth, really good interfaces also suffer, because by definition, most people don't perceive them as elements. Beyond a certain level of frustration, market forces don't work on user interfaces and may even work against good ones, because mediocre interfaces have more visible features.
Many people confuse the Heisenberg Uncertainty Principle with quantum entanglement. They're both part of QM, but they aren't the same view of the universe. You could be picky and say that the Uncertainty Principle is an obvious result of basic quantum principles, but it's also the result of some numbers that describe the way our universe is scaled. Anyway, it doesn't say the same thing in the same way.
The usual workaround is approximation.
Right, and approximation is almost always good enough.
Consider the kind of optimizations that are usually tackled by the simplex method, such as how much of each size shoe or model of computer to make so that you optimize your profits. The simplex method, worst case, is NP. Back in the 1980's, someone in the Soviet Union came up with a guaranteed P solution to those problems which I only vaguely remember (it involved ellipsoids, but that's all I can recall). Did everyone immediately switch? No, because
So, basically, the simplex method is plenty good enough, so people use it. The same is true of others. There are node-visiting problems that are NP, but you can get very close to optimal with simuated annealing or genetic algorithms, which are simple and converge quickly. Is it really worth saving a teacup of fuel by finding an exact solution, which will be way less than how much variation you get from delays on the taxiway?
It is really nice to have an exact, provable solution to a problem from an aesthetic standpoint. However, a solution that works in practice is usually all that is necessary.
As others have pointed out, factoring large numbers isn't even NP in the first place; it's just way harder than constructing two large primes. Even that is due to an approximation, an algorithm that tells you if a number is probably prime.
So, what would happen? We hard-core CS types would be ecstatic, but the rest of the world would mostly just shrug.
You are corect. Pointing out the technical similarities misses the point. A PC is in a completely different cultural category from an entertainment device.
For one thing, the expectation of reliability is much higher for an entertainment device. Companies that put software in televisions are therefore held to a higher standard that those who write software for PC's. Needing to reboot a television set ever is unacceptable. The PC has a culture so accepting of unreliability that any report of any bug or security problem on Slashdot generates a number of replies to the effect of "So what? All software has bugs. Get with the times, luser."
Culturally, building an entertainment center around the PC rather than embedding computers in devices will probably either
It's kind of sad that Slashdot linked to the first part of this series rather than waiting for it to finish.
If they did that, there would be bunches of messages chastizing the linker for linking to old news.
Many who have studied Turing's life believe that this book [turing.org.uk] by Hodges is the definitive work of a man who was arguably a casualty of his lifestyle.
I haven't seen any mention of the fact that there was a play based on this book. I know it ran in London because I saw it there. I think it also ran on Broadway.
the mac api did have a c binding but you had to specify a pascal binding to all your functions
To the extent that this is sort of true, it is still true. Pascal has a different stack convention from the one in C. The convention that Pascal uses was shared by most other languages at the time, but C originated as a system language. C is organized such that functions like printf could take a variable number of parameters using a kludge involving pointing directly to the stack.
However, C and C++ compilers for the Mac all accept the "pascal" keyword, which is included in all the header files for the API. Besides that, you can ignore it, except in the special case where you need to pass a pointer to the API for a callback function. Then you need to declare your function as pascal, too. You have never had to declare all your functions pascal.
Also, the majority of the API calls are not bindings in the strict sense of the word. They use compiler extensions to produce inline traps in the code.
The reason you might be concerned is weather. Large generating plants operate at much higher effeciency but can still affect the local weather significantly. This would affect the local weather several times as much per kilowatt-hour.
It may be that this plant would be too small or Australia is too big to worry about the weather right now. However, one should remember that no method of generating power is without its environmental effects.
I am also skeptical about this greenhouse. It seems to me that you would need an awfully big greenhouse to provide substantial benefit while you're using it to heat air constantly, and it's going to take energy to maintain it. Ever make a greenhouse in high school? It warms up slowly, even when it is sealed.
Sun Microsystems buys one of the three licenses for Office. They put out a version of Office for Linux. However, they also use the expertise that they get from being able legally to examine the source to improve their Star Office compatibility to 100%.
Impossible, you say? There are three licences. I can't think of too many companies that would be interested and have the cash to put up. Sun, IBM, and somebody else. Microsoft is already producting Office for the Macintosh, and it's good. (The Mac development group at Microsoft has a strong maverick culture.)
I think that Sun might just do this out of spite and to shake up Microsoft.
The major advantage to this, however, would be that Microsoft wouldn't be able to rely on its decade-old catch-up techniques for its most popular products. They wouldn't be able to keep the better API calls secret any more.