That the author of the book gives far too much credance/respect to the values and wishes of parents. State controlled education is not bad because it ignores the hopes/beliefs/and desires of the childs family rather it is good precisely *because* it ignores these. Government education is good precisely because it provides a partial antidote to parents inflicting their views, religion or beliefs onto their children. The institution of public educations roll in developing children's independence should not be underestimated.
Moreover, speaking as someone who does and teaches math for a living, many very important skills for modern life simply *are* boring for most people. I'm entierly behind any plan that stops school from crushing the spirit, especially of those who would otherwise turly want to learn but I simply don't see how these things can be taught without a similarly regimented system. Some kids will pay attention if you explain in a creative, interactive way but what do you do with the majority who aren't interested?
Perhaps I misunderstood, let me be sure I understand what is going on now.
So I was wrong when I thought the composting manager handed the composted image back to the program who owns the window. Instead the composting manager takes images from the applications and directly renders them to the screen.
So, for instance, if windows are merely being shifted around or moved theoretically only the composting manager needs to be called to redraw all the appropriate transparency.
Also, would it be possible for the composting manager to take advantage of graphics card acceleration. I may be wrong in this as well but i understand OS X does this for transparency (I think it translates windows into textures for the video card which can be used with the 3d acceleration features).
Now I do agree that there is some worry that media might have wildly incorrect beliefs about what is important. This has the danger of giving people a incorrectly skewed view of what is going on.
If you think this is occuring your option is to start a competing media format. This is particularly easy these days with the web. Accusing some of censorship just because you disagree with them is not appropriate. Project Censored doesn't seem to bother to collect evidence of inappropriate attention or influence and is thus simply disagreeing with mainstream media's notion of importance. This 'cry of wolf' is quite disturbing because it lessens the resistance when *real* censorship occurs. (This project censored sounds like a bunch of librarians who want to get worked up about the censorship that is happening today!)
People choose their media sources based on their estimation of how often they pick the important stories. If the mainstream media consistantly pick stories that don't turn out to be the most important ones for most people they will change their media preferences. If you don't like the fact that Nuclear subsidies don't get attention go start your own web media. I just object to project censored using the word 'censored'. Underreported is really what they mean.
Well I agree that some of these stories probably went unreported for inappropriate reasons (the media can lie) others seem to quite reasonably not be relevant to report. Basically, it seems this 'project censored' group is reading their own political views into this list and blasting the mainstream media when they ignore things this group thinks are important.
As a prime example look at story #10 about the new nuclear power plants. Essentially this is nothing but a US government program to encourage investment in an alternative non-polluting (any pollution is not released into the atmosphere) energy source. I find it hard to believe project censored would be crying crow if congress had implemented tax incentives to individuals using solar power, or buisnesses located in poor areas employing minorities or even a similar credit for wind turbines (I think california already has one and no one has made one peep).
I think this is quite unfortunate. Instead of focusing on instances of true media abuse (government pressure not to report...like the secret arguments it is now trying to make in their case the the EFF) they simply pick out stories they think are important but not reported frequently. This, however, is always a political value judgement. If you aren't ignorantly frightened of nuclear things this bill is no more exceptional to you than tax credits for alternative power or fuel efficent cars (which exist and haven't gotten much coverage).
Even if you object that the populous at large would be quite concerned about this issue you still don't establish your point. The roll of the media is to raise issues of *actuall* concern not of *popular* concern. I have no doubt that project censored would castigate the media for ignoring an important issue just because the public isn't particularly interested (don't understand the true import for instance). The media must use it's judgement and expertise to seperate *truly* important or worrisome events from emotionally grabbing trash. In other words if you retreat to saying the news media has an obligation to report anything which would particular concern the public then you are forced by consistancy to prefer wild emotionally manipulative but content minimal presentations to a balanced reasoned viewpoint. If it is what would *actually* concern the people that is important to report our papers should be filled with scaretactic articles like "1000 items in your house which will give your children cancer."
In other words any reasonable view of the media will attest that it is NOT their job to present viewers/readers with misleading scare tactic articles. It is a common effect that people overestimate very small probabilities, so an article detailing the horrid things that can happen to you going out to the city (being raped and tortured etc..) would grab a lot of unwarranted concern and interest. Instead, as people prefer, upstanding media endeavors to select only *actually* concerning material to present to their readers instead of rilling them up using every misconception and misunderstanding their readers likely share. People's attitudes on nuclear power are similarly irrational as their tendency to overestimate small probabilities. Media therefore arguable has a *responsibility* not to overplay this article.
So I'm not that familiar with what is going on with the X.org so I'm hoping that someone who knows what is going on can tell me if this is really a good long term solution or just a poor hack to extend an architecture not extendable to the needs of a modern interface.
In particular I am concerned that things like transparency seem to be accomplished at the application level rather than the rendering level. In other words, at least on a quick read, it seemed that transparency was handled by the application wishing to display a transparent window asking that window to be rendered off screen, having that composited window returned and then rendering this to the X screen. It would seem a more robust solution would be to allow simple rendering of windows with an alpha component.
I know this might provoke a war over the sufficency of X but I'm hoping to get a few serious responses with technical knowledge about how reasonable it is to do these things without re-enginering X.
Alright, everyone is missing the point. Yes, you can enforce these rules and clearly a buisness should have this right and ability. However, it simply isn't a good idea.
As an employer, like it or not, employee satisfaction and enjoyment make a big difference to your bottom line. Whether or not it is reasonable people naturally chaf and restrictions they find arbitrary or stupid. This is just a base psychological fact about how people work. Locking down the systems completly and not even letting people change transparancy settings or adjust the mouse speed might make things *slightly* easier to administrate but in the long run will cause you more problems in employee moral.
Also, especially if you are running an insecure OS like windows, you need to worry about employees circumventing your security measures. The more you unreasonably restrict them the more likely they are to get around the security measures. Even worse since they are often aware they could get in trouble for circumventing the security measures they will take other actions to hide their changes costing the organization even more money (they screw up the computer which they have modified....if they just ask for help they get in trouble....or they could wipe the harddrive and claim ignorance).
This is why I have been advocating a publication system for wikipedia for some time. To be fair many other people also are behind a publication system but many of them don't see the need for a complex peer-review process.
Wikipedia is an *extremely* valuable resource, in my opinion much better than any commercial encyclopedia (wikipedia has informative articles even in *very* obscure areas of mathematics), however, this puts the project at risk. Regardless of it's accuracy and review problems wikipedia will become a standard resource the same way a google search has become authoritative despite the many things it misses. This unfortunatly presents a huge risk to wikipedia.
So long as it is a small project frequented by a bunch of like minded people simple community checking is enough to deter vandals. At this level the only real vandalism is people trying to up their google rank, or posting insane creeds, and maybe one or two people making weird slashdot experiments. However, as it becomes a general resource very large interest groups (political parties, companies etc..) have a great deal to gain just by slanting the articles a certain way or cleverly removing small tidbits.
The only reasonable way to deal with this is to create a several tiered system, unvalidated pages, validated pages, and published pages. This would be supported by a user reputation system like karma on slashdot but more sophisticated. I realize that a system like this offends many wikipedian's notions that everything should be editable by anyone but I'm afraid that model simply DOESN'T WORK to bring wikipedia up to the next level. This solution tries to deviate the least from the normal paradigm and those who want can always browse the unvalidated pages.
So how would this work? Every time an anonymous user or a user with insufficent reputation submits an edit or article it enters a validation queue. Similar to the slashdot meta-moderation system any logged in user with sufficent reputation (or maybe selected randomly if we have a short queue and many users) is presented with a link on their screens asking them to validate the contribution. Contributions would NOT be fact checked on validation this is just a quick measure to defend against vandalism and other obvious screw ups. Since pages could be validated quite quickly there should *very rarely* be an difference between the validated and unvalidated pages so individuals could freely browse the validated version and edit these pages easily.
Any disagreements over validation could be sent up for more votes on the issue. Users gain reputation by having their edits validated (this can't increase your reputation over a small number to prevent spell-checking scripts). Users also gain reputation if they validate other pages correctly (their validation is supported by other votes on the matter). Long or significant components could also be rated by users if this was needed to further work the reputation system. Everyone sees where this is going of course. Now when the validated page gets to the point where it should replace the current published version a reputable user submits it for publication. This submission of course needs to be voted on by some number of sufficently reputable users to be published.
I know many people will object to such a heavy-handed system and accuse me of wanting to undo all that is good about a wiki. However, I think it is simply an unpleasent fact of life that we can't govern a large extensive community the way you can a small close community. It isn't an accident that small villages can get by on tacit consent and agreement but a nation needs a legal system. Wikipedia is making the transition from village to nation and if they want to maintain the quality of their product they need to transition themselves.
While many people on this board seem skeptical of fast interpreted langauages it really can be accomplished. The problem is that most modern interpreted languages don't bother with these optimizations.
I heard of one interpreter designed to emulate another processor architecture which could sometimes run code for the emulated architecture faster. That is sometimes you would get a speed improvement by compiling the software for the secondary architecture and then running it through the interpreter rather than just compiling it and running natively.
How can something like this work you might ask? Well in the following way. At first the instructions would be entierly interpreted (and thus much slower) but during program execution frequently executed chunks of code would be identified and converted to snippets of native code. Henceforth when this code section was encountered rather than emulating it again control was simply transfered to the pre-compiled piece of code.
This might seem like no better than a JIT compiler but the important difference is that these code snippets and various profiling and branching information would be saved between program executions. Thus after a program had been used frequently it would end up being quite fast, sometimes even faster than native code.
How can this code be faster? A couple reasons. First of all since this 'extra information' was just a local cache it could be optimized to the specific architecture/chip without any fear of compatibility issues (if you find your architecture has changed just whip this cache and go back to interpreting). This means that the code snippets it generates can be evaluated on the machine they run on to see what generates the fastest results (so a program might end up running differntly on a system with a fast memory bus than a slow memory bus).
Secondly real profiling information can make a big difference. Not only does this allow the interpreter to make good branch predictions it allows for a whole new kind of optimization. For instance one might have dynamic loop unrolling where the interpreter has saved code fragments corresponding to 10 itterations of the loop and one corresponding to 5 iterations and one corresponding to 1 iteration. When it realizes it is about to enter a loop with 66 iterations it runs the 10 iteration segment 6 times the 5 iteration segment once and the 1 iteration segment once.
As far as I understand it compared to schemes like this Java interpreters/JIT systems are pretty bad. So long as you don't save a cache of compiled program segments and profiling data you are usually going to be slower than compiling.
Personally, I think this would be a wonderfull concept to design an OS around. The operating system would have a standard virtual machine most programs would coded in...or perhaps several VMs one for java another for mono etc.. Each executeable would have two forks, the first would be the actual code in whatever virtual machine the second would contain a cache of code snippets and profiling information on the current machine. It would also have the wonderfull property that new OS updates could actually make your old programs run faster (better optimization algorithms).
Can someone tell me why this sophisticated sort of technology isn't being used for java? Or is it and I am just missing something?
Very nice explanation, however, I don't think it is that applicable to Java. In particular the interpreted language can benefit three ways, either explicit runtime hints to the interpreter (which java doesn't seem to have), passive learning by the interpreter (branch prediction etc.. etc..), and tuning to the particular processor/machine.
While the last really is a benefit java posesses the other two aren't that relevant. In particular Java is going to be slow because most JIT or interpreters I know of don't seem to remember things from one instance to the next. Probably if the interpreter/JIT saved branch prediction information, profiling and even small compiled native segments it would be much faster but to my knowledge no java implementation does this.
What you can do is to *save* your interpreted code fragments. I know of at least one project that used this method essentially identifying small program segments and compiling these segments into native code.
I simply don't understand why Java programs don't do this and take advantage of the information they gather each time they run. In this manner you can actually make a *faster* app in an interpreted language sometimes because the interprater/compiler can benefit from the run-time performance of the program (i.e. better branch prediction etc..).
However, as a matter of fact I don't think java interprators save all this usefull state data. Why, I can't figure out.
So I'm simply not convinced that this is really going to use the internet. I think the relevant quote from the article is
These applications allow for the creation and transmission of payment messages, account balance monitoring, and other functions performed via encrypted dial-up sessions with the Federal Reserve Bank's host computer.
I think someone misread 'web' as internet. I believe all this means is that it can be accessed using http
Thanks for the more detailed response. I appreciate it. I am however still confused.
As I understand it one can still do frequency modulation on something simple like sound waves. Is this wrong?
My understanding is that sound waves can be frequency modulated using something like the equation I gave before. Namely, P(t) is the air pressure as a function of time so to frequency modulate this we just set
P(t)=sin ( (w+FM(t))*t)
However, if we can do this we can do the same thing with the pressure of green light recieved. Or as you prefer let me give a physical description.
We set up a laser (or perhaps even a system of lasers) transmitting only green photons. Let G(t) be the numder of green photons emited per second. What prevents us from having
G(t)=A(t)*sin ( (w+FM(t))*t)
While this certainly is ridiculous classically, as there is no notion of photons so the frequency of modulation is going to be the same as the frequency of the underlying transmission, I see no problem doing this in QM. It would seem that if I set up a filter allowing through only green photons I could still record the photon pressure (or number of photons per unit time) as a function of time the same way as I do with sound.
Thus I don't see why we couldn't send a light signal with G(t)=A1(t)*sin ( (w+FM1(t))*t) R(t)=A2(t)*sin ( (w+FM2(t))*t)
where G(t) represents the green photons recieved every second and R(t) represents the red. After splitting the incoming signal by the color of the photon it seems we could retrive both the frequency and amplitude modulation of both signals.
I imagine something goes physically wrong when you try and do this but I'm trying to figure out what.
So anyway I may be describing fiber optic communications incorrectly but I know what I'm talking about in terms of modulation. I was under the impression that in fiber optics each frequency of light was itself still modulated at many differnt frequencies. Perhaps I am wrong about this but I would appreciate an answer.
The question is basically the following. Why can't we take a laser that produces pure green light and then modulate it's intensity as a function of time. That is why must the frequency of the signal be the same as the frequency of the underlying photons used *in* the signal.
If you can't understand what I'm saying just say so but don't tell me I don't know what I'm talking about when you are confused. I have started asking various physics grad students about this question and the idea is certainly sound. Perhaps however there is something which is being overlooked, like some reason one couldn't modulate a green laser at a frequency approaching the frequency of the light itself.
So I have a long post about putting more information in radio waves but I realized there is a simpler way to put my question.
Why don't we multiplex radio broadcasts the way we can multiplex fiber optics.
As I understand fiber optics multiplexing the idea is to split the light by the underlying frequency of the light. In a really simple example we might split the red and green light. Now each of these red and green channels gives us a function I(t) or intensity as a function of time which can be both frequency and amplitude modulated.
So by dividing the signal by the frequency of the underlying photons we can send twice (or actually many times more) data. I imagine modern radio antennas are incapable of doing this but I don't see any in principle problem. Of course we would probably have to replace normal recievers with CCDs or something equally complex.
Is there something unworkable about this idea? Perhaps traveling through the air modifies the underlying photon frequency or something.
Okay, apparenly my original post wasn't clear enough. Also, I apoligize if some of my posts were a little harsh. I don't want to give the impression I arrogantly know what I am talking about but I *would* like someone to give me an explanation of exactly what I am getting wrong. Also, I'm looking at this situation from a QM point of view and I'm not sure if it would apply in a classical situation.
For those of you who don't want to read farther I believe what I am proposing is essentially using multiplexing (as in fiber optics) for radio waves.
As an example let us consider soundwaves. Sound is simply pressure changing as a function of time. Now I believe I am correct when I say that you can do both frequency and amplitude modulation on sound. So to produce a sound signal which has amplitude modulation A(t) and frequency modulation F(t) you would produce a pressure wave as a function of time with the following charachteristics.
P(t)=A(t)*sin( (w+F(t))*t) where w is the base frequency.
Now imagine a specially designed radio which only registers photons of a particular frequency UF. Now I can encode a signal in terms of I_UF (the intensity of incoming photons each of frequency UF). So I can make
I_UF=A(t)*sin( (w+F(t))*t)
However, I should now be able to do the same thing at another underlying frequency UF2 without any interference. I think this is the same thing as frequency multiplexing in fiber optics. Of course in order to take advantage of this idea one would need to replace normal radios with CCDs and use differnt transmitters. Hell, if we want to take this really far we might also be able to use the phase of the incoming photons as well to carry information..but I'm not so sure about this one.
If you still think I am getting something wrong could someone please explain why light, where we have two variables the power of the incoming photons and the wavelength of the incoming photons, doesn't allow us to do more than sound where we can only control one variable the pressure. Also, be aware that I am claiming there are really two differnt frequencies at play here. Feel free to explain why I am mistaken but don't just insist that since we can do frequency modulation in FM this is the same kind of frequency modulation I am talking about.
Some of my posts came across a bit harsh. I mean to say I think I know how QAM works and I don't mean to say the original poster got QAM wrong so much as didn't understand what I am saying.
The important point to understand here is that there are really two frequencies in question here. There is frequency_photon and frequency_signal.
To put things another way you could use QAM modulation on a signal composed of pure green (single frequency light). We can encode the intensity of recieved green light by the function I(t)=A(t)*sin( (w+deltaF(t))*t). The term A(t) modulates the amplitude of the signal, deltaF modulates the frequency of the signal but the underlying frequency of the photons is constant.
Another way to put this is to think of fiber optics. In a fiber you will be able to encode information using things like QAM in many differnt channells given by the color of light in question. Since radio signals are no differnt than light why can't we do the same.
I understand we can't get beyond any shannon limit. My point is that because of the physical inadequacies of our radio equitment we aren't really applying shannon's mathematics to the full range of possibilities. Having looked up some information about radio it becomes clear that normal radios convert all incoming data to a simple function of voltage as a function of time. While you might be applying shannons laws correctly in terms of V(t) if you are losing information in this conversion there are more things you can transmit.
You are simply wrong about how QAM works. I looked this up on wikipedia this is a communications technology which works on a simple one variable system. In particular you can use it over phone lines and I think even in sound waves.
Perhaps my initial post didn't explain things well enough. For contrast think of a sound wave which can be completly described given pressure as a function of time. As I understand it QAM works by setting P(t)=s_1(t)*sin((w+s_2(t))*t) or similar. Where s_1(t) and s_2(t) are the channels you wish to send.
As I understand it current radio works similarly. All indications I saw said that radio simply converts the radio waves into voltage so the entire signal can be broken down into a function of voltage as a function of time. However, it would appear that theoretically you could generate a radio signal by specifying a unique intensity at each time and photon frequency.
My point is that in radio waves there are really two frequencies. There is the underlying frequency of the photons used and the frequency of the signal. In other words for each photon frequency we can send a wave by using intensity as a function of time. In fact we should be able to do QAM modulation on the same frequency of intensity simultaneously on each frequency of photons.
Well that is why I asked if I was missing something. However, in the not so much experience I had looking at how AM radio worked it seemed that only one variable was being manipulated.
In other words it has always been described to me as a signal of 'fixed frequency' the amplitude of that frequency is adjusted. I always had taken this to mean that it was a fixed frequency only in approximation. So for instance you could send an AM signal through power lines just using voltage (and not sending radio waves). Just because one thing is frequency modulation and another is amplitude modulation doesn't mean anything, I can do both of these in a system with only one variable.
It's quite possible I'm wrong but I posted in a request for some elucidation not just to be told I'm wrong. Could you explain to me how exactly this works and how you know all of this? In particular how is it that simple radio recievers (which I understand select a frequency by using a simple tuned LRC circut) actually pull out both intensity and frequency of the radiation instead of just intensisty as a function of time (which would also have a frequency).
My point about CDMA and UWB is not specifically advocating these technologies but rather to point out that division into frequencies is only one orthogonal basis for the space, and not necesserily the best one. I agree such a system is more complex and some thought still needs to be put into frequency (some frequencies are good for one things others another) but it is far from clear to me that *assisgning* spectrum based on frequency and not based on something like frequency plus code space might not be better.
In particular it would be advantegous to have dynamic spectrum usage. The way spectrum is allocated now large sections sit aside reserved but rarely used. I see no reason if we moved to a more complex frequency distribution system that they couldn't be given a guaranteed bandwidth but while they aren't using it others could take advantage.
So I have long suspected that one of the big problems is dividing up the spectrum in this frequency model. The way the frequencies are used now is clearly very inefficent, the fact that things like UWB can exist broadcasting into many differnt frequencies without interference problems proves that the system is being inefficent. We have other options like using CDMA technology on the entire spectrum and selling spectrum by codes instead of frequency.
I would propose that spectrum should be viewed as a network and use all the collision avoiding, real-time broadcasting etc.. solutions developed for networks (without routers). Of course things are a little more complicated as some wavelengths have greater penetrating power, broadcast farther etc..
This last sort of consideration has left me very confused about radio. From my physics background I am aware that radio quanta really do possess a property of wavelength that can be measured. Thus in principle I can send two independent variables in a radio signal. I can control the wavelength of the particles emited and the strength of that signal which can both be measured at the reciever (this doesn't contradict the wavelength energy relation for a photon..I can broadcast a signal with Energy E either with 1 photon of wavelenth=W or 10 photons of wavelength 10*W while each individual photon obeys the relationship). So it would seem that at best our current radio uses only one of these variables. Of course it would take better equitment to generate and recieve these signals but the bandwidth benefit would be tremendous.
Is there something I'm missing?
As a side thought if I was a military this is exactly how I would circumvent radio jamming. By looking not only at intensity of recieved radiation (as I think normal radios do) but also the frequency of that radiation it would be simple to distingush the true signal from the jamming one. Of course now that the bad guys read this slashdot post they will know how to jam this signal as well.
Are people here *really* trying to figure out the source of a joke? No doubt someone (if not multiple independent people) came up with it while stoned at some rave. The comedian probably just borrowed it (and perhaps improved it) from one of his friends.
Why don't we try and figure out where the chicken joke came from.
I am also amazed that not only have many people here not heard the joke but took it literally. Then again I am replying to these people so I don't have much of a leg to stand on.
So as the other poster says you don't really move across the room. If you did this then the technology wouldn't be any better than the floor. The best way to think about it is like a 360 degree treadmill that is always travelling at exactly the opposite speed and direction as you are walking.
While this does mean you get the physical motion of moving and everything should be fine so long as you are moving at a constant speed. Acceleration might be very screwed up however and I worry walking on this platform will feel like slipping on a skateboard. If the platforms move backward to compensate for your movements it will feel like what your stepping on is sliding back instead of you being pushed forward.
Perhaps with enough tiles though they can make the backward acceleration of the tiles small enough not to be noticeable.
Yes, it keeps accelerating over long distances....but I can make a rocket do the same thing by asymptotically slowing down the rate of fuel burn. A solar sail is doing nothing differnt, while the sail will keep accelerating the accelaration will fall off with the radiation pressure (about 1/r^2).
Personally, I tend to believe things like ion drive are actually much more efficent and likely to work well with stare exploration (ion drive is just a fancy way of saying you shoot very small amounts of mass out the back going very fast. This is important because it means you can get more thrust from the same amount of fuel weight if you have something like a nuclear power source to accelerate the ions).
Slashdot Mirror
That the author of the book gives far too much credance/respect to the values and wishes of parents. State controlled education is not bad because it ignores the hopes/beliefs/and desires of the childs family rather it is good precisely *because* it ignores these. Government education is good precisely because it provides a partial antidote to parents inflicting their views, religion or beliefs onto their children. The institution of public educations roll in developing children's independence should not be underestimated.
Moreover, speaking as someone who does and teaches math for a living, many very important skills for modern life simply *are* boring for most people. I'm entierly behind any plan that stops school from crushing the spirit, especially of those who would otherwise turly want to learn but I simply don't see how these things can be taught without a similarly regimented system. Some kids will pay attention if you explain in a creative, interactive way but what do you do with the majority who aren't interested?
Perhaps I misunderstood, let me be sure I understand what is going on now.
So I was wrong when I thought the composting manager handed the composted image back to the program who owns the window. Instead the composting manager takes images from the applications and directly renders them to the screen.
So, for instance, if windows are merely being shifted around or moved theoretically only the composting manager needs to be called to redraw all the appropriate transparency.
Also, would it be possible for the composting manager to take advantage of graphics card acceleration. I may be wrong in this as well but i understand OS X does this for transparency (I think it translates windows into textures for the video card which can be used with the 3d acceleration features).
Now I do agree that there is some worry that media might have wildly incorrect beliefs about what is important. This has the danger of giving people a incorrectly skewed view of what is going on.
If you think this is occuring your option is to start a competing media format. This is particularly easy these days with the web. Accusing some of censorship just because you disagree with them is not appropriate. Project Censored doesn't seem to bother to collect evidence of inappropriate attention or influence and is thus simply disagreeing with mainstream media's notion of importance. This 'cry of wolf' is quite disturbing because it lessens the resistance when *real* censorship occurs. (This project censored sounds like a bunch of librarians who want to get worked up about the censorship that is happening today!)
People choose their media sources based on their estimation of how often they pick the important stories. If the mainstream media consistantly pick stories that don't turn out to be the most important ones for most people they will change their media preferences. If you don't like the fact that Nuclear subsidies don't get attention go start your own web media. I just object to project censored using the word 'censored'. Underreported is really what they mean.
Well I agree that some of these stories probably went unreported for inappropriate reasons (the media can lie) others seem to quite reasonably not be relevant to report. Basically, it seems this 'project censored' group is reading their own political views into this list and blasting the mainstream media when they ignore things this group thinks are important.
As a prime example look at story #10 about the new nuclear power plants. Essentially this is nothing but a US government program to encourage investment in an alternative non-polluting (any pollution is not released into the atmosphere) energy source. I find it hard to believe project censored would be crying crow if congress had implemented tax incentives to individuals using solar power, or buisnesses located in poor areas employing minorities or even a similar credit for wind turbines (I think california already has one and no one has made one peep).
I think this is quite unfortunate. Instead of focusing on instances of true media abuse (government pressure not to report...like the secret arguments it is now trying to make in their case the the EFF) they simply pick out stories they think are important but not reported frequently. This, however, is always a political value judgement. If you aren't ignorantly frightened of nuclear things this bill is no more exceptional to you than tax credits for alternative power or fuel efficent cars (which exist and haven't gotten much coverage).
Even if you object that the populous at large would be quite concerned about this issue you still don't establish your point. The roll of the media is to raise issues of *actuall* concern not of *popular* concern. I have no doubt that project censored would castigate the media for ignoring an important issue just because the public isn't particularly interested (don't understand the true import for instance). The media must use it's judgement and expertise to seperate *truly* important or worrisome events from emotionally grabbing trash. In other words if you retreat to saying the news media has an obligation to report anything which would particular concern the public then you are forced by consistancy to prefer wild emotionally manipulative but content minimal presentations to a balanced reasoned viewpoint. If it is what would *actually* concern the people that is important to report our papers should be filled with scaretactic articles like "1000 items in your house which will give your children cancer."
In other words any reasonable view of the media will attest that it is NOT their job to present viewers/readers with misleading scare tactic articles. It is a common effect that people overestimate very small probabilities, so an article detailing the horrid things that can happen to you going out to the city (being raped and tortured etc..) would grab a lot of unwarranted concern and interest. Instead, as people prefer, upstanding media endeavors to select only *actually* concerning material to present to their readers instead of rilling them up using every misconception and misunderstanding their readers likely share. People's attitudes on nuclear power are similarly irrational as their tendency to overestimate small probabilities. Media therefore arguable has a *responsibility* not to overplay this article.
So I'm not that familiar with what is going on with the X.org so I'm hoping that someone who knows what is going on can tell me if this is really a good long term solution or just a poor hack to extend an architecture not extendable to the needs of a modern interface.
In particular I am concerned that things like transparency seem to be accomplished at the application level rather than the rendering level. In other words, at least on a quick read, it seemed that transparency was handled by the application wishing to display a transparent window asking that window to be rendered off screen, having that composited window returned and then rendering this to the X screen. It would seem a more robust solution would be to allow simple rendering of windows with an alpha component.
I know this might provoke a war over the sufficency of X but I'm hoping to get a few serious responses with technical knowledge about how reasonable it is to do these things without re-enginering X.
Alright, everyone is missing the point. Yes, you can enforce these rules and clearly a buisness should have this right and ability. However, it simply isn't a good idea.
As an employer, like it or not, employee satisfaction and enjoyment make a big difference to your bottom line. Whether or not it is reasonable people naturally chaf and restrictions they find arbitrary or stupid. This is just a base psychological fact about how people work. Locking down the systems completly and not even letting people change transparancy settings or adjust the mouse speed might make things *slightly* easier to administrate but in the long run will cause you more problems in employee moral.
Also, especially if you are running an insecure OS like windows, you need to worry about employees circumventing your security measures. The more you unreasonably restrict them the more likely they are to get around the security measures. Even worse since they are often aware they could get in trouble for circumventing the security measures they will take other actions to hide their changes costing the organization even more money (they screw up the computer which they have modified....if they just ask for help they get in trouble....or they could wipe the harddrive and claim ignorance).
Why is there a link to some crackpots theory of physics at the bottom of this article? Is this not a reputable source?
This is why I have been advocating a publication system for wikipedia for some time. To be fair many other people also are behind a publication system but many of them don't see the need for a complex peer-review process.
Wikipedia is an *extremely* valuable resource, in my opinion much better than any commercial encyclopedia (wikipedia has informative articles even in *very* obscure areas of mathematics), however, this puts the project at risk. Regardless of it's accuracy and review problems wikipedia will become a standard resource the same way a google search has become authoritative despite the many things it misses. This unfortunatly presents a huge risk to wikipedia.
So long as it is a small project frequented by a bunch of like minded people simple community checking is enough to deter vandals. At this level the only real vandalism is people trying to up their google rank, or posting insane creeds, and maybe one or two people making weird slashdot experiments. However, as it becomes a general resource very large interest groups (political parties, companies etc..) have a great deal to gain just by slanting the articles a certain way or cleverly removing small tidbits.
The only reasonable way to deal with this is to create a several tiered system, unvalidated pages, validated pages, and published pages. This would be supported by a user reputation system like karma on slashdot but more sophisticated. I realize that a system like this offends many wikipedian's notions that everything should be editable by anyone but I'm afraid that model simply DOESN'T WORK to bring wikipedia up to the next level. This solution tries to deviate the least from the normal paradigm and those who want can always browse the unvalidated pages.
So how would this work? Every time an anonymous user or a user with insufficent reputation submits an edit or article it enters a validation queue. Similar to the slashdot meta-moderation system any logged in user with sufficent reputation (or maybe selected randomly if we have a short queue and many users) is presented with a link on their screens asking them to validate the contribution. Contributions would NOT be fact checked on validation this is just a quick measure to defend against vandalism and other obvious screw ups. Since pages could be validated quite quickly there should *very rarely* be an difference between the validated and unvalidated pages so individuals could freely browse the validated version and edit these pages easily.
Any disagreements over validation could be sent up for more votes on the issue. Users gain reputation by having their edits validated (this can't increase your reputation over a small number to prevent spell-checking scripts). Users also gain reputation if they validate other pages correctly (their validation is supported by other votes on the matter). Long or significant components could also be rated by users if this was needed to further work the reputation system. Everyone sees where this is going of course. Now when the validated page gets to the point where it should replace the current published version a reputable user submits it for publication. This submission of course needs to be voted on by some number of sufficently reputable users to be published.
I know many people will object to such a heavy-handed system and accuse me of wanting to undo all that is good about a wiki. However, I think it is simply an unpleasent fact of life that we can't govern a large extensive community the way you can a small close community. It isn't an accident that small villages can get by on tacit consent and agreement but a nation needs a legal system. Wikipedia is making the transition from village to nation and if they want to maintain the quality of their product they need to transition themselves.
While many people on this board seem skeptical of fast interpreted langauages it really can be accomplished. The problem is that most modern interpreted languages don't bother with these optimizations.
I heard of one interpreter designed to emulate another processor architecture which could sometimes run code for the emulated architecture faster. That is sometimes you would get a speed improvement by compiling the software for the secondary architecture and then running it through the interpreter rather than just compiling it and running natively.
How can something like this work you might ask? Well in the following way. At first the instructions would be entierly interpreted (and thus much slower) but during program execution frequently executed chunks of code would be identified and converted to snippets of native code. Henceforth when this code section was encountered rather than emulating it again control was simply transfered to the pre-compiled piece of code.
This might seem like no better than a JIT compiler but the important difference is that these code snippets and various profiling and branching information would be saved between program executions. Thus after a program had been used frequently it would end up being quite fast, sometimes even faster than native code.
How can this code be faster? A couple reasons. First of all since this 'extra information' was just a local cache it could be optimized to the specific architecture/chip without any fear of compatibility issues (if you find your architecture has changed just whip this cache and go back to interpreting). This means that the code snippets it generates can be evaluated on the machine they run on to see what generates the fastest results (so a program might end up running differntly on a system with a fast memory bus than a slow memory bus).
Secondly real profiling information can make a big difference. Not only does this allow the interpreter to make good branch predictions it allows for a whole new kind of optimization. For instance one might have dynamic loop unrolling where the interpreter has saved code fragments corresponding to 10 itterations of the loop and one corresponding to 5 iterations and one corresponding to 1 iteration. When it realizes it is about to enter a loop with 66 iterations it runs the 10 iteration segment 6 times the 5 iteration segment once and the 1 iteration segment once.
As far as I understand it compared to schemes like this Java interpreters/JIT systems are pretty bad. So long as you don't save a cache of compiled program segments and profiling data you are usually going to be slower than compiling.
Personally, I think this would be a wonderfull concept to design an OS around. The operating system would have a standard virtual machine most programs would coded in...or perhaps several VMs one for java another for mono etc.. Each executeable would have two forks, the first would be the actual code in whatever virtual machine the second would contain a cache of code snippets and profiling information on the current machine. It would also have the wonderfull property that new OS updates could actually make your old programs run faster (better optimization algorithms).
Can someone tell me why this sophisticated sort of technology isn't being used for java? Or is it and I am just missing something?
Very nice explanation, however, I don't think it is that applicable to Java. In particular the interpreted language can benefit three ways, either explicit runtime hints to the interpreter (which java doesn't seem to have), passive learning by the interpreter (branch prediction etc.. etc..), and tuning to the particular processor/machine.
While the last really is a benefit java posesses the other two aren't that relevant. In particular Java is going to be slow because most JIT or interpreters I know of don't seem to remember things from one instance to the next. Probably if the interpreter/JIT saved branch prediction information, profiling and even small compiled native segments it would be much faster but to my knowledge no java implementation does this.
What you can do is to *save* your interpreted code fragments. I know of at least one project that used this method essentially identifying small program segments and compiling these segments into native code.
I simply don't understand why Java programs don't do this and take advantage of the information they gather each time they run. In this manner you can actually make a *faster* app in an interpreted language sometimes because the interprater/compiler can benefit from the run-time performance of the program (i.e. better branch prediction etc..).
However, as a matter of fact I don't think java interprators save all this usefull state data. Why, I can't figure out.
Check out the security procedures section. It states quite clearly the two options are dedicated lines or using a telephone (by hand).
Unless someone can't point out where it really says they are going online I'm going to assume this is just a confusion of web interface with internet.
I think someone misread 'web' as internet. I believe all this means is that it can be accessed using http
Thanks for the more detailed response. I appreciate it. I am however still confused.
As I understand it one can still do frequency modulation on something simple like sound waves. Is this wrong?
My understanding is that sound waves can be frequency modulated using something like the equation I gave before. Namely, P(t) is the air pressure as a function of time so to frequency modulate this we just set
P(t)=sin ( (w+FM(t))*t)
However, if we can do this we can do the same thing with the pressure of green light recieved. Or as you prefer let me give a physical description.
We set up a laser (or perhaps even a system of lasers) transmitting only green photons. Let G(t) be the numder of green photons emited per second. What prevents us from having
G(t)=A(t)*sin ( (w+FM(t))*t)
While this certainly is ridiculous classically, as there is no notion of photons so the frequency of modulation is going to be the same as the frequency of the underlying transmission, I see no problem doing this in QM. It would seem that if I set up a filter allowing through only green photons I could still record the photon pressure (or number of photons per unit time) as a function of time the same way as I do with sound.
Thus I don't see why we couldn't send a light signal with
G(t)=A1(t)*sin ( (w+FM1(t))*t)
R(t)=A2(t)*sin ( (w+FM2(t))*t)
where G(t) represents the green photons recieved every second and R(t) represents the red. After splitting the incoming signal by the color of the photon it seems we could retrive both the frequency and amplitude modulation of both signals.
I imagine something goes physically wrong when you try and do this but I'm trying to figure out what.
So anyway I may be describing fiber optic communications incorrectly but I know what I'm talking about in terms of modulation. I was under the impression that in fiber optics each frequency of light was itself still modulated at many differnt frequencies. Perhaps I am wrong about this but I would appreciate an answer.
The question is basically the following. Why can't we take a laser that produces pure green light and then modulate it's intensity as a function of time. That is why must the frequency of the signal be the same as the frequency of the underlying photons used *in* the signal.
If you can't understand what I'm saying just say so but don't tell me I don't know what I'm talking about when you are confused. I have started asking various physics grad students about this question and the idea is certainly sound. Perhaps however there is something which is being overlooked, like some reason one couldn't modulate a green laser at a frequency approaching the frequency of the light itself.
So I have a long post about putting more information in radio waves but I realized there is a simpler way to put my question.
Why don't we multiplex radio broadcasts the way we can multiplex fiber optics.
As I understand fiber optics multiplexing the idea is to split the light by the underlying frequency of the light. In a really simple example we might split the red and green light. Now each of these red and green channels gives us a function I(t) or intensity as a function of time which can be both frequency and amplitude modulated.
So by dividing the signal by the frequency of the underlying photons we can send twice (or actually many times more) data. I imagine modern radio antennas are incapable of doing this but I don't see any in principle problem. Of course we would probably have to replace normal recievers with CCDs or something equally complex.
Is there something unworkable about this idea? Perhaps traveling through the air modifies the underlying photon frequency or something.
Okay, apparenly my original post wasn't clear enough. Also, I apoligize if some of my posts were a little harsh. I don't want to give the impression I arrogantly know what I am talking about but I *would* like someone to give me an explanation of exactly what I am getting wrong. Also, I'm looking at this situation from a QM point of view and I'm not sure if it would apply in a classical situation.
For those of you who don't want to read farther I believe what I am proposing is essentially using multiplexing (as in fiber optics) for radio waves.
As an example let us consider soundwaves. Sound is simply pressure changing as a function of time. Now I believe I am correct when I say that you can do both frequency and amplitude modulation on sound. So to produce a sound signal which has amplitude modulation A(t) and frequency modulation F(t) you would produce a pressure wave as a function of time with the following charachteristics.
P(t)=A(t)*sin( (w+F(t))*t) where w is the base frequency.
Now imagine a specially designed radio which only registers photons of a particular frequency UF. Now I can encode a signal in terms of I_UF (the intensity of incoming photons each of frequency UF). So I can make
I_UF=A(t)*sin( (w+F(t))*t)
However, I should now be able to do the same thing at another underlying frequency UF2 without any interference. I think this is the same thing as frequency multiplexing in fiber optics. Of course in order to take advantage of this idea one would need to replace normal radios with CCDs and use differnt transmitters. Hell, if we want to take this really far we might also be able to use the phase of the incoming photons as well to carry information..but I'm not so sure about this one.
If you still think I am getting something wrong could someone please explain why light, where we have two variables the power of the incoming photons and the wavelength of the incoming photons, doesn't allow us to do more than sound where we can only control one variable the pressure. Also, be aware that I am claiming there are really two differnt frequencies at play here. Feel free to explain why I am mistaken but don't just insist that since we can do frequency modulation in FM this is the same kind of frequency modulation I am talking about.
Some of my posts came across a bit harsh. I mean to say I think I know how QAM works and I don't mean to say the original poster got QAM wrong so much as didn't understand what I am saying.
No, I'm not. I understand how QAM works.
The important point to understand here is that there are really two frequencies in question here. There is frequency_photon and frequency_signal.
To put things another way you could use QAM modulation on a signal composed of pure green (single frequency light). We can encode the intensity of recieved green light by the function I(t)=A(t)*sin( (w+deltaF(t))*t). The term A(t) modulates the amplitude of the signal, deltaF modulates the frequency of the signal but the underlying frequency of the photons is constant.
Another way to put this is to think of fiber optics. In a fiber you will be able to encode information using things like QAM in many differnt channells given by the color of light in question. Since radio signals are no differnt than light why can't we do the same.
I understand we can't get beyond any shannon limit. My point is that because of the physical inadequacies of our radio equitment we aren't really applying shannon's mathematics to the full range of possibilities. Having looked up some information about radio it becomes clear that normal radios convert all incoming data to a simple function of voltage as a function of time. While you might be applying shannons laws correctly in terms of V(t) if you are losing information in this conversion there are more things you can transmit.
You are simply wrong about how QAM works. I looked this up on wikipedia this is a communications technology which works on a simple one variable system. In particular you can use it over phone lines and I think even in sound waves.
Perhaps my initial post didn't explain things well enough. For contrast think of a sound wave which can be completly described given pressure as a function of time. As I understand it QAM works by setting P(t)=s_1(t)*sin((w+s_2(t))*t) or similar. Where s_1(t) and s_2(t) are the channels you wish to send.
As I understand it current radio works similarly. All indications I saw said that radio simply converts the radio waves into voltage so the entire signal can be broken down into a function of voltage as a function of time. However, it would appear that theoretically you could generate a radio signal by specifying a unique intensity at each time and photon frequency.
My point is that in radio waves there are really two frequencies. There is the underlying frequency of the photons used and the frequency of the signal. In other words for each photon frequency we can send a wave by using intensity as a function of time. In fact we should be able to do QAM modulation on the same frequency of intensity simultaneously on each frequency of photons.
Well that is why I asked if I was missing something. However, in the not so much experience I had looking at how AM radio worked it seemed that only one variable was being manipulated.
In other words it has always been described to me as a signal of 'fixed frequency' the amplitude of that frequency is adjusted. I always had taken this to mean that it was a fixed frequency only in approximation. So for instance you could send an AM signal through power lines just using voltage (and not sending radio waves). Just because one thing is frequency modulation and another is amplitude modulation doesn't mean anything, I can do both of these in a system with only one variable.
It's quite possible I'm wrong but I posted in a request for some elucidation not just to be told I'm wrong. Could you explain to me how exactly this works and how you know all of this? In particular how is it that simple radio recievers (which I understand select a frequency by using a simple tuned LRC circut) actually pull out both intensity and frequency of the radiation instead of just intensisty as a function of time (which would also have a frequency).
My point about CDMA and UWB is not specifically advocating these technologies but rather to point out that division into frequencies is only one orthogonal basis for the space, and not necesserily the best one. I agree such a system is more complex and some thought still needs to be put into frequency (some frequencies are good for one things others another) but it is far from clear to me that *assisgning* spectrum based on frequency and not based on something like frequency plus code space might not be better.
In particular it would be advantegous to have dynamic spectrum usage. The way spectrum is allocated now large sections sit aside reserved but rarely used. I see no reason if we moved to a more complex frequency distribution system that they couldn't be given a guaranteed bandwidth but while they aren't using it others could take advantage.
So I have long suspected that one of the big problems is dividing up the spectrum in this frequency model. The way the frequencies are used now is clearly very inefficent, the fact that things like UWB can exist broadcasting into many differnt frequencies without interference problems proves that the system is being inefficent. We have other options like using CDMA technology on the entire spectrum and selling spectrum by codes instead of frequency.
I would propose that spectrum should be viewed as a network and use all the collision avoiding, real-time broadcasting etc.. solutions developed for networks (without routers). Of course things are a little more complicated as some wavelengths have greater penetrating power, broadcast farther etc..
This last sort of consideration has left me very confused about radio. From my physics background I am aware that radio quanta really do possess a property of wavelength that can be measured. Thus in principle I can send two independent variables in a radio signal. I can control the wavelength of the particles emited and the strength of that signal which can both be measured at the reciever (this doesn't contradict the wavelength energy relation for a photon..I can broadcast a signal with Energy E either with 1 photon of wavelenth=W or 10 photons of wavelength 10*W while each individual photon obeys the relationship). So it would seem that at best our current radio uses only one of these variables. Of course it would take better equitment to generate and recieve these signals but the bandwidth benefit would be tremendous.
Is there something I'm missing?
As a side thought if I was a military this is exactly how I would circumvent radio jamming. By looking not only at intensity of recieved radiation (as I think normal radios do) but also the frequency of that radiation it would be simple to distingush the true signal from the jamming one. Of course now that the bad guys read this slashdot post they will know how to jam this signal as well.
Are people here *really* trying to figure out the source of a joke? No doubt someone (if not multiple independent people) came up with it while stoned at some rave. The comedian probably just borrowed it (and perhaps improved it) from one of his friends.
Why don't we try and figure out where the chicken joke came from.
I am also amazed that not only have many people here not heard the joke but took it literally. Then again I am replying to these people so I don't have much of a leg to stand on.
So as the other poster says you don't really move across the room. If you did this then the technology wouldn't be any better than the floor. The best way to think about it is like a 360 degree treadmill that is always travelling at exactly the opposite speed and direction as you are walking.
While this does mean you get the physical motion of moving and everything should be fine so long as you are moving at a constant speed. Acceleration might be very screwed up however and I worry walking on this platform will feel like slipping on a skateboard. If the platforms move backward to compensate for your movements it will feel like what your stepping on is sliding back instead of you being pushed forward.
Perhaps with enough tiles though they can make the backward acceleration of the tiles small enough not to be noticeable.
Yes, it keeps accelerating over long distances....but I can make a rocket do the same thing by asymptotically slowing down the rate of fuel burn. A solar sail is doing nothing differnt, while the sail will keep accelerating the accelaration will fall off with the radiation pressure (about 1/r^2).
Personally, I tend to believe things like ion drive are actually much more efficent and likely to work well with stare exploration (ion drive is just a fancy way of saying you shoot very small amounts of mass out the back going very fast. This is important because it means you can get more thrust from the same amount of fuel weight if you have something like a nuclear power source to accelerate the ions).