This article takes a very interesting report on a reference implementation of some innovative ideas in OS design and reduces it to a couple of entirely peripheral, seat-of-the-pants benchmarks that support the "OSS rulez!" thesis.
Even people like me, who have only a basic knowledge of OS architecture, can tell you that processes are lightweight in Unix and heavyweight in Windows. The lightweight objects in Windows are threads, which is why Windows makes so much use of threads, while Unix spawns processes left and right.
I do have the background to judge the believability of this claim (Ph. D. in theortetical elementary particle physics) and I'll tell you: this is fucking embarassing.
Here's a simple way to judge these sorts of claims that doesn't require any scientific training: major breakthroughs in fundamental physics are not made by people developing a secret product that will solve the world's energy problems.
No, because science is not about injesting the facts as described by official scientists. It's about learning how to ask interesting, well-defined, and testable questions, how to look for holes theories -- including your own, and how to analyze data.
Hear, hear! I am a scientist, am convinced that evolution happens, and yet I am repulsed by the emotionalist, dogmatic response of many in the "scientific" camp to those who want to challenge evolution. Let the intelligent design folks have their say -- perhaps the debate will peak students' interest and hone their critical thinking skills.
Since I am a physicist, when I make this suggestion I am often get the response: "you wouldn't want a Ptolemaic astronomy taught in your physics class, would you?" My answer is: hell, yes. If I could get a someone to come in front of my class and argue that the sun goes around the earth, I think that would be a great opportunity for my students.
Deriving an equilibrium wage using supply and demand curves has nothing to do with Keynesian economic theory. Economists (and mere mortals) understood the effects of supply and demand on wages long before the mid-20th century.
Sigh... Microsoft bears some blame for their "IE is part of the OS" legal rhetoric, but for technicially competent people to still think that meant that IE ran in kernel space is really inexcusable.
IE never ran in kernel space. Nowdays many parts of it don't even run with user privleges, but are hieved off to a process that runs with even fewer privleges than the user. When Microsoft said "IE is part of the OS", what they meant, in technical terms, is: it's important that we ship the HTML processing library on which IE is based in the Windows box, so that application writers can be sure of always having a consistant HTML processing library available on the machine.
Obviously, E=mc^2 is better-known, and you are welcome to view it as the p=0 special case, a formula for the energy content of a mass at rest. (And useful for computing the energy released in a nuclear or particle reaction that changes the mass of the reagents by m.)
But Einstein himself viewed E=mc^2 as the correct formula even for non-zero p. The reason is that he preferred to define mass via Newton's Law F=ma, which requires m to be velocity-dependent (thus the title of his paper "Does the inertia of a body depend on its energy-content?"). Modern physicists tend to prefer to use m to represent rest-mass, which gives the formula you quote relating energy, momentum, and rest-mass.
I never cease to be amazed at people's bizarre ideas about the labor market.
It is not a blow to employment when a new technology eliminates some job, because those people go off and do other stuff. Think about it: after RFID, we can do all the same stuff we did with the cashiers, plus we can use all that freed up labor do even more stuff that we couldn't do before, because we used to need those people to be cashiers.
200 years ago 90% of us were farmers. Today 2% are. If your theory were true, we would now have 88% unemployment.
Re:...the same features we delivered seven years a
on
Windows 95 Turns 10
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· Score: 1
Monad isn't vaporware; I'm running it on the machine I'm typing this on.
And Mondad does have some really cool features that have never been available from the standard *nix shells.
I'm not talking about wizards and paper-clips. I'm a command-line junkie who has always installed the cygwin tools on any Windows box I work on, and I'm telling you Monad is way cool.
Monad commands (which are, like *nix shell commads, little programs) pipe in and out objects, not just text. These objects have text representations and you are welcome to parse them that way, but using their object-ness often makes life much easier.
Here is a trivial example: Suppose you want the day of the week corresponding to the timestamp of the file test. In unix, you could invoke ls -l or some other command than can extract the timestamp, then parse the text output to extract the day number part, then invoke some other logic to convert that to a day of the week. In Monday, you just do
(get-item test).LastWriteTime.DayOfWeek. (get-item test) returned a file object and you extracted its LastWriteTime property, which was a date-time object, then extracted the DayOfWeek property of that date-time object. These same file and date-time objects, with the same properties, are returned and accepted by all the Monad commands.
Anyone who has ever tried to write a shell script that processes the output of unix's ps command with cry with joy at Monad. (By the way, get-process is the Monad equivilent of ps.)
The environmental doom-and-gloom crowd love to talk about rising sea levels, but they usually neglect to mention that it the predictions range from a few inches to a few feet. There aren't that many places where this would cause serious trouble, and most of them tend to be inhabited by poor people.
Here's hoping that the two parties have agreed on which data will decide the bet.
While it's safe to say that the preponderance of the data favor warming over the last 50 years, it's also safe to say that individual measurements have been all over the place. Sea, air, and troposphere measurements aren't consistent, and the year-to-year noise is larger than the signal.
Troll?! Jeez, okay, that does it. Here are step-by-step instructions.
The sun and all the planets are, to a good approximation, all in the same plane, so we only need to do the simulation in 2D. To track positions, define a vector structure with properties X and Y. For convenience, give it a constructor that can take angular coordinates.
Define a function R(p1,p2) that takes two positions and computes the distance between them. That's just Sqrt((p1.X-p2.X)^2 + (p1.Y+p2.Y)^2).
Define a function that, given the position p of a satelite of unit mass and the position P of a massive body M, computes the force of the body on the satelite. That's just a vector of magnitude G M / R(p,P)^2 and a direction proportional to (p.X-P.X,p.Y-P.Y).
Now define a function that, given the position of a satelite p, and the positions of earth and mars p_E and p_M, adds the forces due to earth, mars, and the sun. (Assume that the sun is fixed at the origin.) This just involves calling your function three times and doing vector addition.
There is no need to compute the motion of the earth and mars, just look up their distance from the sun and their orbital period, and create functions that return their position as a function of time. The eccentricities of their orbits are so small that you can assume their orbits are circular.
Combining your work so far, you have a function that, given the time t and the satelite position p, returns the force on the satelite. Now all you have to do is integrate F=a (remember m=1). If you have experience with numerical methods, you could use a canned predictor-corrector algorithm, but for our quick-and-dirty purposes, just use a fixed time-step. 10-hour time-steps are probably fine, but you may need to experiment.
Insert a line in your integrator that prints out the time and position after each step. You're done.
To get this approximately right, you need to consider just 3 contributions to the gravitational potential that determines the ship's motion: the sun, the earth, and mars.
If you are a programmer, and your physics/math isn't sufficiently good for you to write a simple simulation of motion in this potential in your favorite programming language, then you are out of your depth. I'm an ex-physicist, and it would take me about 30 minutes to write such a simulation in any programming language I know.
I'd tell your businessman friend that I really like free wifi, so I would come to his shop. I probably wouldn't buy his coffee or food, but I'd bring lots of friends and we'd play first-person-shooter games and yell taunts across the cafe at each other.
Really, I think the goverment should implement free, universal wifi because... Well, because I want it. Then I could check my email when my car is stopped at a traffic light.
The argument you give is the best one can make for anti-payola laws. The reason I think it's still a lame justification is that can always be used to justify any government intervention.
Governemnt: Here, have free food. You: Thanks! Government: Since we are giving you food, we will now regulate your caloric consumption and dietary balance. You: WTF?!
Government: Here, have a book. You: Thanks! Government: Since books are a public resource, we will now regulate what books get published and how many you may consume. You: WTF!?
The proper response to a market distortion is to eliminate the distortion, not to try to introduce more countervailing distortions.
what if all the stations in your area all play the same music?
What if the vast majority of people are happy with Sechuan Chineese food, but you want Cantonese? Should the governemnt step in are make sure your tastes are represented, despite the lack of demand?
If there is enough demand for alternative music, there is profit to be made in buying a radio station license and playing alternative music. If there isn't, it's not the government's job to ensure the market caters to your personal preferences.
If a DJ accepts a direct payment when his employment contract forbids it, that's breach of contract.
If a radio station advertises that they don't accept payola, but they do, that's fraud.
But if a radio station wants to make a strait-up pay-for-play deal with a record producer, why should the government care? If it really bothers listeners, a competitor can lure those listeners away by promising not to.
There is the really lame argument that the airwaves are a public trust, but that just means the government was dumb enough not to auction them to the highest bidder.
There is the only slightly less lame argument that music should compete on quality alone. But if the listeners don't care, and somebody has to be the popular band, why not the one that pays the most money?
Uh, isn't it actually a violation of the worker's rights to tell him that he cannot enter into such a contract?
Employer: We want a 1-year non-compete clause. Employee: Okay, if you up the salary by 15%. Employer: 10%. Employee: Done. (They shake hands. Poof! Uncle Sam appears.) Uncle Sam: Sorry, even though you have come to a mutual agreement, I can't let you sign that contract. It would violate your rights!
Privatizing unemployment insurance would have a lot of positive benefits.
First off, you should realize that government-run unemployment insurance schemes are not attempting to do anything actually progressive. The rate you pay increases with your chance of unemployment, and your benefit increases with your salary. A private insurance firm would operate in just this way.
That said, there is a lot of political interference in the system that makes it hard to pin down just what the terms of the contract you have with the government are. Politicians often extend unemployment benefits during a recession, meaning that those people get a better deal than people who became unemployment earlier. Politicans also respond to industry pressures; for example the building industry in my state pays proportionally much less into the system than they should, given unemployment claims they generate. Competition in a private market would force benefits, rates, and risks into alignment.
Also, a private system could allow people to taylor their unemployment insurance to their risk tollerance. A young, single person who is making real money for the first time would likely have little unemployment insurance, since he could easily scale back his lifestyle. A guy nearing retirement with a mortgage whose salary feeds 3 kids would likely want to load up on unemployment insurance, and would be willing to pay proportionally more.
A lot of people on slashdot seemt to think "fair use rights" are some legal prohibitions against copy protection. As in: "This DRM system violates my fair use rights." They are talking out of their asses.
Fair use rights merely say that, having copied some copyrighted material, you won't get sued, providing certain (rather subjective) criteria are met. They don't guarantee that you can, or can easily, make the copy in the first place.
Furthermore, fair use rights are not constitutional rights, they are merely rights recognized by common law precedent. So if the government writes a law that narrows the scope of your fair use rights (e.g. DMCA), you can argue that the law is unwise, but you can't argue that the law is unconsitiutional. (Or if you do, you can't expect any court to pay attention to your argument.)
It's true that, if you can pay an open source outfit to produce your software less than a propriatary solution costs, you're ahread.
Of course, if someone else pays the open source outfit to produce the software, and you get it for free, you're even further ahead.
You have just understood one of the economic disincentives for open source development.
Slashdot Mirror
This article takes a very interesting report on a reference implementation of some innovative ideas in OS design and reduces it to a couple of entirely peripheral, seat-of-the-pants benchmarks that support the "OSS rulez!" thesis.
Even people like me, who have only a basic knowledge of OS architecture, can tell you that processes are lightweight in Unix and heavyweight in Windows. The lightweight objects in Windows are threads, which is why Windows makes so much use of threads, while Unix spawns processes left and right.
I do have the background to judge the believability of this claim (Ph. D. in theortetical elementary particle physics) and I'll tell you: this is fucking embarassing.
Here's a simple way to judge these sorts of claims that doesn't require any scientific training: major breakthroughs in fundamental physics are not made by people developing a secret product that will solve the world's energy problems.
No, because science is not about injesting the facts as described by official scientists. It's about learning how to ask interesting, well-defined, and testable questions, how to look for holes theories -- including your own, and how to analyze data.
Hear, hear! I am a scientist, am convinced that evolution happens, and yet I am repulsed by the emotionalist, dogmatic response of many in the "scientific" camp to those who want to challenge evolution. Let the intelligent design folks have their say -- perhaps the debate will peak students' interest and hone their critical thinking skills.
Since I am a physicist, when I make this suggestion I am often get the response: "you wouldn't want a Ptolemaic astronomy taught in your physics class, would you?" My answer is: hell, yes. If I could get a someone to come in front of my class and argue that the sun goes around the earth, I think that would be a great opportunity for my students.
Deriving an equilibrium wage using supply and demand curves has nothing to do with Keynesian economic theory. Economists (and mere mortals) understood the effects of supply and demand on wages long before the mid-20th century.
Yeah, that's what I thought when I was in college and living on $11k a year. Now I make $95k a year and I agree with the parent post.
Sigh... Microsoft bears some blame for their "IE is part of the OS" legal rhetoric, but for technicially competent people to still think that meant that IE ran in kernel space is really inexcusable.
IE never ran in kernel space. Nowdays many parts of it don't even run with user privleges, but are hieved off to a process that runs with even fewer privleges than the user. When Microsoft said "IE is part of the OS", what they meant, in technical terms, is: it's important that we ship the HTML processing library on which IE is based in the Windows box, so that application writers can be sure of always having a consistant HTML processing library available on the machine.
Obviously, E=mc^2 is better-known, and you are welcome to view it as the p=0 special case, a formula for the energy content of a mass at rest. (And useful for computing the energy released in a nuclear or particle reaction that changes the mass of the reagents by m.)
But Einstein himself viewed E=mc^2 as the correct formula even for non-zero p. The reason is that he preferred to define mass via Newton's Law F=ma, which requires m to be velocity-dependent (thus the title of his paper "Does the inertia of a body depend on its energy-content?"). Modern physicists tend to prefer to use m to represent rest-mass, which gives the formula you quote relating energy, momentum, and rest-mass.
I never cease to be amazed at people's bizarre ideas about the labor market.
It is not a blow to employment when a new technology eliminates some job, because those people go off and do other stuff. Think about it: after RFID, we can do all the same stuff we did with the cashiers, plus we can use all that freed up labor do even more stuff that we couldn't do before, because we used to need those people to be cashiers.
200 years ago 90% of us were farmers. Today 2% are. If your theory were true, we would now have 88% unemployment.
Monad isn't vaporware; I'm running it on the machine I'm typing this on.
And Mondad does have some really cool features that have never been available from the standard *nix shells.
I'm not talking about wizards and paper-clips. I'm a command-line junkie who has always installed the cygwin tools on any Windows box I work on, and I'm telling you Monad is way cool.
Monad commands (which are, like *nix shell commads, little programs) pipe in and out objects, not just text. These objects have text representations and you are welcome to parse them that way, but using their object-ness often makes life much easier.
Here is a trivial example: Suppose you want the day of the week corresponding to the timestamp of the file test. In unix, you could invoke ls -l or some other command than can extract the timestamp, then parse the text output to extract the day number part, then invoke some other logic to convert that to a day of the week. In Monday, you just do (get-item test).LastWriteTime.DayOfWeek. (get-item test) returned a file object and you extracted its LastWriteTime property, which was a date-time object, then extracted the DayOfWeek property of that date-time object. These same file and date-time objects, with the same properties, are returned and accepted by all the Monad commands.
Anyone who has ever tried to write a shell script that processes the output of unix's ps command with cry with joy at Monad. (By the way, get-process is the Monad equivilent of ps.)
The environmental doom-and-gloom crowd love to talk about rising sea levels, but they usually neglect to mention that it the predictions range from a few inches to a few feet. There aren't that many places where this would cause serious trouble, and most of them tend to be inhabited by poor people.
Here's hoping that the two parties have agreed on which data will decide the bet.
While it's safe to say that the preponderance of the data favor warming over the last 50 years, it's also safe to say that individual measurements have been all over the place. Sea, air, and troposphere measurements aren't consistent, and the year-to-year noise is larger than the signal.
Troll?! Jeez, okay, that does it. Here are step-by-step instructions.
The sun and all the planets are, to a good approximation, all in the same plane, so we only need to do the simulation in 2D. To track positions, define a vector structure with properties X and Y. For convenience, give it a constructor that can take angular coordinates.
Define a function R(p1,p2) that takes two positions and computes the distance between them. That's just Sqrt((p1.X-p2.X)^2 + (p1.Y+p2.Y)^2).
Define a function that, given the position p of a satelite of unit mass and the position P of a massive body M, computes the force of the body on the satelite. That's just a vector of magnitude G M / R(p,P)^2 and a direction proportional to (p.X-P.X,p.Y-P.Y).
Now define a function that, given the position of a satelite p, and the positions of earth and mars p_E and p_M, adds the forces due to earth, mars, and the sun. (Assume that the sun is fixed at the origin.) This just involves calling your function three times and doing vector addition.
There is no need to compute the motion of the earth and mars, just look up their distance from the sun and their orbital period, and create functions that return their position as a function of time. The eccentricities of their orbits are so small that you can assume their orbits are circular.
Combining your work so far, you have a function that, given the time t and the satelite position p, returns the force on the satelite. Now all you have to do is integrate F=a (remember m=1). If you have experience with numerical methods, you could use a canned predictor-corrector algorithm, but for our quick-and-dirty purposes, just use a fixed time-step. 10-hour time-steps are probably fine, but you may need to experiment.
Insert a line in your integrator that prints out the time and position after each step. You're done.
I asked a rocket scientist what he said to indicate that something isn't so difficult. He said: I say, "this isn't nuclear physics."
I asked a nuclear physicist what he said to incicate that something isn't so difficult. He said: I say, "this isn't brain surgery."
I asked a brain surgeon what he said to indicate that something isn't so difficult. He said: I say, "this isn't rocket science."
To get this approximately right, you need to consider just 3 contributions to the gravitational potential that determines the ship's motion: the sun, the earth, and mars. If you are a programmer, and your physics/math isn't sufficiently good for you to write a simple simulation of motion in this potential in your favorite programming language, then you are out of your depth. I'm an ex-physicist, and it would take me about 30 minutes to write such a simulation in any programming language I know.
I'd tell your businessman friend that I really like free wifi, so I would come to his shop. I probably wouldn't buy his coffee or food, but I'd bring lots of friends and we'd play first-person-shooter games and yell taunts across the cafe at each other. Really, I think the goverment should implement free, universal wifi because... Well, because I want it. Then I could check my email when my car is stopped at a traffic light.
The argument you give is the best one can make for anti-payola laws. The reason I think it's still a lame justification is that can always be used to justify any government intervention.
Governemnt: Here, have free food. You: Thanks! Government: Since we are giving you food, we will now regulate your caloric consumption and dietary balance. You: WTF?!
Government: Here, have a book. You: Thanks! Government: Since books are a public resource, we will now regulate what books get published and how many you may consume. You: WTF!?
The proper response to a market distortion is to eliminate the distortion, not to try to introduce more countervailing distortions.
What if the vast majority of people are happy with Sechuan Chineese food, but you want Cantonese? Should the governemnt step in are make sure your tastes are represented, despite the lack of demand?
If there is enough demand for alternative music, there is profit to be made in buying a radio station license and playing alternative music. If there isn't, it's not the government's job to ensure the market caters to your personal preferences.
Why exactly should this be illegal?
If a DJ accepts a direct payment when his employment contract forbids it, that's breach of contract.
If a radio station advertises that they don't accept payola, but they do, that's fraud.
But if a radio station wants to make a strait-up pay-for-play deal with a record producer, why should the government care? If it really bothers listeners, a competitor can lure those listeners away by promising not to.
There is the really lame argument that the airwaves are a public trust, but that just means the government was dumb enough not to auction them to the highest bidder.
There is the only slightly less lame argument that music should compete on quality alone. But if the listeners don't care, and somebody has to be the popular band, why not the one that pays the most money?
Uh, isn't it actually a violation of the worker's rights to tell him that he cannot enter into such a contract?
Employer: We want a 1-year non-compete clause. Employee: Okay, if you up the salary by 15%. Employer: 10%. Employee: Done. (They shake hands. Poof! Uncle Sam appears.) Uncle Sam: Sorry, even though you have come to a mutual agreement, I can't let you sign that contract. It would violate your rights!
Privatizing unemployment insurance would have a lot of positive benefits.
First off, you should realize that government-run unemployment insurance schemes are not attempting to do anything actually progressive. The rate you pay increases with your chance of unemployment, and your benefit increases with your salary. A private insurance firm would operate in just this way.
That said, there is a lot of political interference in the system that makes it hard to pin down just what the terms of the contract you have with the government are. Politicians often extend unemployment benefits during a recession, meaning that those people get a better deal than people who became unemployment earlier. Politicans also respond to industry pressures; for example the building industry in my state pays proportionally much less into the system than they should, given unemployment claims they generate. Competition in a private market would force benefits, rates, and risks into alignment.
Also, a private system could allow people to taylor their unemployment insurance to their risk tollerance. A young, single person who is making real money for the first time would likely have little unemployment insurance, since he could easily scale back his lifestyle. A guy nearing retirement with a mortgage whose salary feeds 3 kids would likely want to load up on unemployment insurance, and would be willing to pay proportionally more.
Actually, that theory works fine for most businesses. Financial services businesses are subject to a special law requiring that they retain all email.
It's often called the prosecutor's fallacy. Just google for it.
It involves confusing the odds of A, given B, with the odds of B, given A.
A lot of people on slashdot seemt to think "fair use rights" are some legal prohibitions against copy protection. As in: "This DRM system violates my fair use rights." They are talking out of their asses. Fair use rights merely say that, having copied some copyrighted material, you won't get sued, providing certain (rather subjective) criteria are met. They don't guarantee that you can, or can easily, make the copy in the first place. Furthermore, fair use rights are not constitutional rights, they are merely rights recognized by common law precedent. So if the government writes a law that narrows the scope of your fair use rights (e.g. DMCA), you can argue that the law is unwise, but you can't argue that the law is unconsitiutional. (Or if you do, you can't expect any court to pay attention to your argument.)
It's true that, if you can pay an open source outfit to produce your software less than a propriatary solution costs, you're ahread. Of course, if someone else pays the open source outfit to produce the software, and you get it for free, you're even further ahead. You have just understood one of the economic disincentives for open source development.