When using a very large, genetically diverse population it doesn't matter very much how hilly the search space is. When you are using a small population of 5, it matters a lot more. The technique described in the article is akin to taking a bunch of random steps in the seach space and following the one that turned out the best. If the terrain is too hilly, this isn't any better than randomly guessing a bunch of parameters and picking the set that worked best.
People don't write code for free operating systems "for the good of the community". They do it because it's what they want to do. That is the truly great thing about the open source community; everyone does exactly what they want to do. Who am I to say that Joe Blow shouldn't write yet another window manager if that's what he wants to do? If people wanted to be told what to code, they would get a job programming and get paid for it.
If you open up the case, most of the time it is pretty easy to find the wires that go to the LEDs. If the wires connect to the motherboard with a plastic connector, just pop it out. If they are hardwired, clip the wires. No more lights.
If I get one, that's the first project! Most people might not write their own GUI, but through the wonders of open source, if one person gets a good GUI working, everyone can benefit.
Linux is actually a kernel. The command line you are talking about is really bash or csh or whatever. The ability to run Linux on a handheld is cool because you can write your own programs to control it. That's why I would want to run Linux on it, so that I could make my own clean, tight graphical interface. Installing Linux on it right now might not be terribly useful, but it gives you power and flexibility. You aren't locked in to WinCE or some other fixed, non-customisable OS.
If you follow the previously posted links, you will see that the Apple II did in fact have subpixel rendering. The basic idea was that RB were on one side of the pixel and G was on the other side. So by drawing purple and green dots in the right places you could make lines anti-aliased. This is exactly the same fundamental idea as ClearType.
I seem to remember some C64 demos that programmed the video hardware to get subpixel accuracy, but I think that was more of a hack of the hardware.
My first take on the license was that the GPL covers the entire thing. To download Plan 9, you have to agree to be bound by all the terms of the agreement. In the definitions section, the agreement is defined to include the GPL. So my understanding is that you are agreeing to be bound by the GPL in addition to all the terms in the Plan 9 license. (Before someone flames saying that the GPL doesn't let you add conditions, remember that the copyright owner can do anything they want to with their license).
Upon a second reading, I think they meant for just the ghostscript fonts to be GPL. But it hardly matters, because the Plan 9 license is basically the GPL anyway.
I actually have fast permanent connection to the Internet (reliability is another story...) What I mean by not thinking about "connecting to the internet" is more than just having a permanent connection. I mean that you shouldn't have to think about where things are located if you don't want to. When I come home from work, I still have to copy files back and forth from my work computer and my home computer to keep working. That should all be handled by the operating system. There should be an easy way to tell the OS which files you want to keep around wherever you go, and which files you want to stay local. I'm sure there's some way to do this with Unix, but it's not natural to the system.
Rob Pike is right. Systems research is waning, in amount of research done and influence. New operating systems are hard to find (there are lots of experimental kernels, but not too many complete systems). This is sad, because I think operating systems have a long way to go before they are finished evolving. The Unix model has stood the test of time. Other systems have come and gone, but the Unix model remains. It is like an old cathedral. Many cathedrals fall, so new builders base their designs on the ones that kept standing.
Here are some random features I want to see in an operating system.
You turn on the computer and it works instantly.
Whenever you feel like stopping you turn off the computer.
You never have to save your files, you always work with up-to-date information
You never have to drag or resize a window
My mom can store her weaving project ideas on it without any help
You never have to remember obscure names, everything is built out of a small set of simple blocks
You never think about "connecting to the internet", you just work with data that happens to be located somewhere else
The kernel continually decides how to configure itself for maximum efficiency for the task at hand
There are never any library problems -- library specifications are written in a formal mathematical language, which can be verified against the library code
Even if they do count as system libraries (which they should), then the same part that keeps Microsoft from shipping GPL Windows programs with Windows keeps Debian from shipping KDE programs with their distribution.
I think a lot of people are forgetting that StarOffice is available for Windows as well as Linux. Choosing to use StarOffice as an office standard does NOT mean that everyone has to learn Linux. It simply means that everyone has to learn StarOffice. I think it is very reasonable to standardize on StarOffice in the workplace, especially if many workers use Unix. It is low-cost, rich in functionality, and supports the de-facto MS-Office file standards. If your work involves sending out lots of complex MS-Word format files, you might not want to standardize on StarOffice. Otherwise, I think it is a good choice.
Why is it helpful to have the recipe for the soda printed on the can? Maybe I just don't get it, but it's not like you'll take a sip and say, "A little too sweet", send in a bug-fix, and then next time you pick up a case it will be less sweet. I'd rather have an open-source TV than a softdrink.
I do like the idea of Perl scripts on the can. Though I would put actual working scripts that do something useful rather than "cute" scripts.
Superluminal speeds are pretty cool. There is a great descriptive article in Scientific American, August 1993 about superluminal tunnelling effects that I found very helpful in intuitively understanding these types of things.
In the SciAm article the experiment is set up so that two pulses get shot and detected by separate photodiodes. One pulse goes through vacuum the whole way, and the other one has to tunnel through a thin barrier. The one that tunnels through the barrier gets to the detector first! Does that mean the pulse went faster than light inside the barrier? Well, sort of.
What's really going on is a quantum mechanical effect. A pulse isn't really a sharp spike. It exists in the real world, so it has width and really looks like a hump. When it hits the barrier, most of the hump gets reflected back. Only part of the hump tunnels through. The part that tunnels through is the front edge of the hump. When the two pulses get detected, the center of the tunnelling hump is ahead of the center of the non-tunnelling hump.
This explanation is less crazy than the faster-than-light explanation, and it explains why this type of thing can't send information faster than light. If you think about it, the height of the small hump is the same as the height of the leading edge of the untunnelled hump. So for a given detector, you can sense the presence of a pulse at the same time whether it tunnelled or not.
I don't really know exactly what is going on in this case, but I imagine that looking at it in the right way makes it less sensationalistic and more intuitive.
Summing multiple random sources usually gives you a normal distribution, i.e. bell-shaped probability curve. The bell curve is generated by e^(-x^2), so scaling this curve and shifting it, then rounding to the nearest integer should solve this problem. As you add more and more dice, the probability of the sums looks more and more like a bell curve. (I remember doing some stuff with this when I was into D&D).
I don't personally use IDEs. Make is 10 times more powerful than any IDE I've tried. But IDEs are really important for new programmers. When you're learning your first language, you don't want to be simultaneously learning the make language.
There needs to be a cool, easy to use IDE for Python (and similar languages) that lets novice programmers do interesting things and learn how to program. We had BASIC. You typed stuff, it did it. You could make games, and do graphics. There needs to be an environment like that for budding programmers. This project looks like it might deliver.
In your algorithm you say to "count from 1 to 2^n" where n is the size of the list. That is the problem right there, looping 2^n times is exponential (2^n is an exponential, not a polynomial). Polynomial time algorithms are allowed to loop n times, or n^2 times, even n^100 times. But you're not allowed to loop 2^n times in a polynomial time algorithm.
Given the background of most readers of Slashdot, if you are thinking of trying to solve one of these problems the best one might be the P=NP problem. Most of the others require some high-level knowledge of mathematics or physics. The high powered theoretic scientists have all taken a look at P=NP. I think real progress will come from a non-specialist who has really original ideas about new algorithms.
What you have to do: find an algorithm to solve any of the following problems in polynomial time.
Given a graph, find a cycle (loop) that visits every vertex exactly once (Hamiltonian cycle problem)
Given a weighted graph, find the least-weight path that visits every vertex (Travelling salesman)
Given a phrase of boolean variables, determine if any combination of values for variables makes the phrase true (Satisfiability)
Given a set of numbers, and a target sum, determine if any combination of the numbers add up to the target sum (Subset-sum problem)
Most CS people think that P is not equal to NP. They might be right, but I think we have vastly underestimated the power of polynomial time algorithms.
Problems that are in P can be solved for sure in polynomial time. Problems in NP have solutions that can be verified in polynomial time. For example, in the subset-sum problem it is easy to verify that the sum of a certain combination of numbers adds up to the target. It is harder to come up with the right combination. But is it so much harder that it cannot be done in polynomial time? Maybe not.
You could do real wordprocessing on an old PowerMac. I agree. But my experience with PowerMac's is that every once in a while the system hangs for no reason. That is why Linux is so cool. It does what it's supposed to do.
When I use something, I expect it to live up to its promises. If a part says that its temperature range is -20 to 200 degrees fahrenheit, it damn well better work when it gets up to 190 degrees. If you buy a fridge, you expect it to keep your food cold. Is it acceptable if every once in a while the fridge gets warm and all your food is ruined? So why do we complacently let Windows crash and lose our work? I expect my operating system to work.
When you're doing real work (like spreadsheets, word processing, data entry, etc.) you want the operating system to do its job. I've lost too much data to Windows to trust it with anything more than my high scores.
Math is not about being able to perform long division. Memorizing arbitrary rules for dividing numbers is not math. Punching numbers into a calculator is not math. Math is a way of thinking about problems. It is a formal system of abstraction. What are numbers? Abstractions of groups of everyday things. Three apples, three houses, three people, etc. What are variables? An abstraction of numbers.
Learning mathematics is learning how to think abstractly. There is some advantage to knowing how to do arithmetic, for example when you are shopping and need to figure out how much something will cost when it is on sale for 30% off. But arithmetic should not be the focus of math courses. Calculators take the focus away from arithmetic and put it at a higher conceptual level.
Does learning every command of x86 assembly make you a better programmer? Well, sometimes it's useful. But nowadays we have things called compilers that do all that for you. Tools don't make you dumber; they let you tackle more complicated problems. Of course calculators can be misused in the classroom, but used correctly they force the student to spend more time actually thinking.
This is a really good point. For free software to remain a thriving, expanding enterprise, free software development tools must keep pace. Imagine how many people that use free software now would be using it if they had to pay $500 to buy a compiler first. Not as many. Imagine how many teenagers would be developing software if they had to shell out $500. Not many. The previous poster is right, GCC will always be around. But things evolve. New languages come out, new paradigms for writing software. Free software simply has to keep up.
Luckily, most new languages today are free. The only glaring exception is Java, and there are projects underway to fix that. Also, programmers involved in free software also tend to be heavily interested in new tools, compilers, etc. This is good.
Change the standard so that if an implementation is compliant, it really does interoperate with other standards-compliant implementations. This is the correct solution. I sincerely hope this change to the standard works out. Microsoft then has two choices: keep its version and admit to the world that it cares more about extending its monopoly than providing solutions to its customers, or change its implementation to play nice with Unix. Either way is a win for the community.
According to the article, Microsoft said, "It's not about free speech. We're not asking for people's comments to be pulled down." EXCUSE ME??? That's exactly what they were asking in their letter to Slashdot. Fuck Microsoft.
Slashdot Mirror
When using a very large, genetically diverse population it doesn't matter very much how hilly the search space is. When you are using a small population of 5, it matters a lot more. The technique described in the article is akin to taking a bunch of random steps in the seach space and following the one that turned out the best. If the terrain is too hilly, this isn't any better than randomly guessing a bunch of parameters and picking the set that worked best.
People don't write code for free operating systems "for the good of the community". They do it because it's what they want to do. That is the truly great thing about the open source community; everyone does exactly what they want to do. Who am I to say that Joe Blow shouldn't write yet another window manager if that's what he wants to do? If people wanted to be told what to code, they would get a job programming and get paid for it.
If you open up the case, most of the time it is pretty easy to find the wires that go to the LEDs. If the wires connect to the motherboard with a plastic connector, just pop it out. If they are hardwired, clip the wires. No more lights.
nojw
nojw
THE WITNESS: The answer is, any time that you circumvent an encryption for whatever reason you are breaking the law.
Q Is regional coding encryption?
Confidential
I seem to remember some C64 demos that programmed the video hardware to get subpixel accuracy, but I think that was more of a hack of the hardware.
nojw
charachter doesn't have any character
Upon a second reading, I think they meant for just the ghostscript fonts to be GPL. But it hardly matters, because the Plan 9 license is basically the GPL anyway.
nojw
I actually have fast permanent connection to the Internet (reliability is another story...) What I mean by not thinking about "connecting to the internet" is more than just having a permanent connection. I mean that you shouldn't have to think about where things are located if you don't want to. When I come home from work, I still have to copy files back and forth from my work computer and my home computer to keep working. That should all be handled by the operating system. There should be an easy way to tell the OS which files you want to keep around wherever you go, and which files you want to stay local. I'm sure there's some way to do this with Unix, but it's not natural to the system.
This is what every recipient of spam wishes they could do! All I can say is wow.
Here are some random features I want to see in an operating system.
- You turn on the computer and it works instantly.
- Whenever you feel like stopping you turn off the computer.
- You never have to save your files, you always work with up-to-date information
- You never have to drag or resize a window
- My mom can store her weaving project ideas on it without any help
- You never have to remember obscure names, everything is built out of a small set of simple blocks
- You never think about "connecting to the internet", you just work with data that happens to be located somewhere else
- The kernel continually decides how to configure itself for maximum efficiency for the task at hand
- There are never any library problems -- library specifications are written in a formal mathematical language, which can be verified against the library code
nojwnojw
nojw
I do like the idea of Perl scripts on the can. Though I would put actual working scripts that do something useful rather than "cute" scripts.
nojw
In the SciAm article the experiment is set up so that two pulses get shot and detected by separate photodiodes. One pulse goes through vacuum the whole way, and the other one has to tunnel through a thin barrier. The one that tunnels through the barrier gets to the detector first! Does that mean the pulse went faster than light inside the barrier? Well, sort of.
What's really going on is a quantum mechanical effect. A pulse isn't really a sharp spike. It exists in the real world, so it has width and really looks like a hump. When it hits the barrier, most of the hump gets reflected back. Only part of the hump tunnels through. The part that tunnels through is the front edge of the hump. When the two pulses get detected, the center of the tunnelling hump is ahead of the center of the non-tunnelling hump.
This explanation is less crazy than the faster-than-light explanation, and it explains why this type of thing can't send information faster than light. If you think about it, the height of the small hump is the same as the height of the leading edge of the untunnelled hump. So for a given detector, you can sense the presence of a pulse at the same time whether it tunnelled or not.
I don't really know exactly what is going on in this case, but I imagine that looking at it in the right way makes it less sensationalistic and more intuitive.
-Nathan Whitehead
I believe the computer system in Jurassic Park is Unix. (I'm sure it's Unix in the book).
Summing multiple random sources usually gives you a normal distribution, i.e. bell-shaped probability curve. The bell curve is generated by e^(-x^2), so scaling this curve and shifting it, then rounding to the nearest integer should solve this problem. As you add more and more dice, the probability of the sums looks more and more like a bell curve. (I remember doing some stuff with this when I was into D&D).
There needs to be a cool, easy to use IDE for Python (and similar languages) that lets novice programmers do interesting things and learn how to program. We had BASIC. You typed stuff, it did it. You could make games, and do graphics. There needs to be an environment like that for budding programmers. This project looks like it might deliver.
In your algorithm you say to "count from 1 to 2^n" where n is the size of the list. That is the problem right there, looping 2^n times is exponential (2^n is an exponential, not a polynomial). Polynomial time algorithms are allowed to loop n times, or n^2 times, even n^100 times. But you're not allowed to loop 2^n times in a polynomial time algorithm.
What you have to do: find an algorithm to solve any of the following problems in polynomial time.
- Given a graph, find a cycle (loop) that visits every vertex exactly once (Hamiltonian cycle problem)
- Given a weighted graph, find the least-weight path that visits every vertex (Travelling salesman)
- Given a phrase of boolean variables, determine if any combination of values for variables makes the phrase true (Satisfiability)
- Given a set of numbers, and a target sum, determine if any combination of the numbers add up to the target sum (Subset-sum problem)
Most CS people think that P is not equal to NP. They might be right, but I think we have vastly underestimated the power of polynomial time algorithms.Problems that are in P can be solved for sure in polynomial time. Problems in NP have solutions that can be verified in polynomial time. For example, in the subset-sum problem it is easy to verify that the sum of a certain combination of numbers adds up to the target. It is harder to come up with the right combination. But is it so much harder that it cannot be done in polynomial time? Maybe not.
-Nathan Whitehead
When I use something, I expect it to live up to its promises. If a part says that its temperature range is -20 to 200 degrees fahrenheit, it damn well better work when it gets up to 190 degrees. If you buy a fridge, you expect it to keep your food cold. Is it acceptable if every once in a while the fridge gets warm and all your food is ruined? So why do we complacently let Windows crash and lose our work? I expect my operating system to work.
When you're doing real work (like spreadsheets, word processing, data entry, etc.) you want the operating system to do its job. I've lost too much data to Windows to trust it with anything more than my high scores.
This is a common sentiment. It is also wrong.
Math is not about being able to perform long division. Memorizing arbitrary rules for dividing numbers is not math. Punching numbers into a calculator is not math. Math is a way of thinking about problems. It is a formal system of abstraction. What are numbers? Abstractions of groups of everyday things. Three apples, three houses, three people, etc. What are variables? An abstraction of numbers.
Learning mathematics is learning how to think abstractly. There is some advantage to knowing how to do arithmetic, for example when you are shopping and need to figure out how much something will cost when it is on sale for 30% off. But arithmetic should not be the focus of math courses. Calculators take the focus away from arithmetic and put it at a higher conceptual level.
Does learning every command of x86 assembly make you a better programmer? Well, sometimes it's useful. But nowadays we have things called compilers that do all that for you. Tools don't make you dumber; they let you tackle more complicated problems. Of course calculators can be misused in the classroom, but used correctly they force the student to spend more time actually thinking.
-Nathan Whitehead
Luckily, most new languages today are free. The only glaring exception is Java, and there are projects underway to fix that. Also, programmers involved in free software also tend to be heavily interested in new tools, compilers, etc. This is good.
-Nathan Whitehead
According to the article, Microsoft said, "It's not about free speech. We're not asking for people's comments to be pulled down." EXCUSE ME??? That's exactly what they were asking in their letter to Slashdot. Fuck Microsoft.
-Nathan Whitehead