However, p + B11 -> 3He is not the only reaction to occur, but I don't know what consequences to expect from that.
Neutrons, like the poor and nutjob enviros, will always be with us. Depending on contaminants (10B is a problem, I believe) and wall materials, the neutron production rate can be made significantly lower than the fusion rate in pB fusion.
Typically a ratio of less than 1% is considered "aneutronic", although I still wouldn't want to stand too close to such a reactor. However, production of radioactive waste, which is expected to be much lower in fusion plants due to the preponderance of low-Z materials, scales linearly with nuetron production, so the waste levels from 1% ratio reactors will be 100 times lower than from conventional D/T fusion.
My dealings with Vonage were not dissimilar. They've still never paid me what they owe me, although my credit card company successfully challenged the "cancelation fee" they charged me when I found that they didn't have local numbers in my area (despite the fact that I checked on that specifically when signing up.)
So I kinda do hope they go public--it'll be an opportunity to make more than the amount they owe me, as this has all the makings of a great short-term investment: a rapidly-growing company that's the leader in the "next big thing", where no one wants to get left behind even though no one knows how to make money at it.
Yes, do. Farnsworth had clear priority on filing date. RCA engineers read his patents, visited his lab and discussed his patents with him--which he felt free to do because he had patent protection--and then mined old notebooks for things that they could claim were sufficiently similar to Farnsworth's work to give them priority. Having tied him up in legal challenges, they then proceeded to steal his ideas, keeping him stalled until after his patents had expired.
Under first-to-file they would have had a much larger legal incentive to license Farnsworth's patents. The whole legal smoke-screen that RCA used was dependent on first-to-invent.
The book, "The Last Lone Inventor" is a very good history of Farnsworth's tragedy.
I wonder if the tunneling you describe is just one more example of phase speed vs group speed, or if it's actually negative impedance (whatever that means).
I can't provide references off the top of my head, but tunneling occurs in such a way that no information is transmitted at velocities greater than c. One of the early quantum papers--from Phys. Rev. in 1929 or thereabouts--addresses this topic by doing a numerical solution to the time-dependent Schrodinger Equation for a wave-packet incident on a rectangular barrier. It's all 1D, but the bottom line is that no usable information is available prior to when it would be available if the barrier were not in place.
The thing to realize is that the time-development of the wave-packet is perfectly ordinary under the barrier: the wave packet propogates toward the barrier, interacts with it, and propogates past it. The basics of the time-evolution are the same regardless of whether or not the particle the wave-packet describes has negative energy under the barrier. The only thing that is different is that the solution to the wave equation under the barrier is a real exponentential rather than a complex exponentional.
So yeah, if you like, the group velocity is always c or less, regardless of what the phase velocity needs to be to match the boundary conditions on the far side of the barrier.
The original poster was making a well-known critique of evolutionary just-so stories. I've made it myself, and never felt required to give attribution (as he has done in a follow-up post.) His point stands on its own, and does not require any authority to back it up.
Replacing "stories" with "theories" won't do, because a story is not a theory, and a theory is not a story. If that replacement were made the post would be about something different.
Non-predictive just-so stories are the bane of evolutionary biology, and especially evolutionary psychology, which is viewed by some serious researchers (myself included) as hardly more than a collection of such unjustified yet somehow plausible hand-wavings:
Rockets cost ~$1000/kg to get to LEO (the space shuttle costs ten times that). A space elevator will lift the same to GEO for a fraction of the cost. The energy required (estimated conservatively) is about 150 MJ/kg, or about 50 kWh/kg. Energy prices currently run 5 to 10 cents per kWh, so we're talking an energy cost of about $5/kg. Let's say the total cost per kg for the space elevator is five times that, in keeping with other modes of transportation, for a total cost of $25/kg. It could easily be lower than that.
So if a space elevator cost a trillion dollars (enough capital for 4000 shuttle flights) it would take about a billion kg lifted to make the difference, although again, this is lift to GEO, not LEO, so I'm being very unfair to the space elevator. This is equivalent to 35,000 shuttle flights with full payload (to LEO).
Bottom line: the space elevator won't be built until the cost is well under a hundred billion dollars, but this is quite reasonable. There is no reason to believe that a trillion dollars is required. Most of the cost is in the rockets to carry the first assemblers up to GEO with sufficient material to run the first strand down to Earth. After that, assembly can be done from the ground.
So the relatively low cost of rockets is actually going to make the space elevator more likely in the long run, not less.
Oliver Heaviside is one of the forgotten men of science, much like Philo T. Farnsworth (inventor of the electronic television) is one of the forgotten men of engineering.
As well as casting Maxwell's equations in their modern (vector) form, he contributed to work in relativity, and if memory serves first wrote down E=mc^2 in 1892. David Bohm's book on special relativity covers this in considerable detail.
This is not to diminish the contribution of Einstein, who worked mostly independently of previously known results, but to make it clear that there were others who set the stage for Einstein's great performance.
The fundamental contribution of Einstein was his ability to show that results that had previously been derived by people like Heaviside and Lorentz with great difficulty from an electro-mechanical dynamical model of the electron could be generalized and proven very simply as a result of a purely kinematic invariance.
Outside of a very restricted park environment I can see a serious potential for tragedy here.
What are the odds of the non-native species staying inside a "very restricted park environment" forever?
So why not release them into the wild now, and get the inevitable over with? Regardless of whether the effects of release into the wild will be good or bad, importation of breeding pairs of environmentally-compatible species into North America is equivalent to the release of those species into the wild, because we can be certain that they will be released into the wild ("by accident") at some time in the future.
The specific nature of the "accident" is unpredictable, but the fact that there will be an unintended release is certain.
Why bother with a fence? The animals are certain to get loose. Given sufficient time, the outcome is a foregone conclusion.
So the question for anyone proposing anything like this is: "Given that you are committed to releasing these animals free and uncontrolled into the wild, why are you not doing so immediately? What purpose is the fence supposed to serve?"
Any time any environmentally compatible non-native species is imported to any area for any reason it will always eventually get loose, breed in the wild, diplace local species and disrupt the local ecology.
Now, the disruption of the native ecosystem may or may not be a "good thing" from a human/economic point of view. Nature introduces new species all the time, and sometimes they turn out to benefit (some) humans. But for humans to play at introducing new species as if they had any control of the process once the critters get loose is simply irresponsible.
I believe that CPAN is one of the major (if not the only) things keeping Perl alive and well.
My own experience suggests this is absolutely true. I learned a bit of Perl in 2000, then had a look at Python, and realized that 90% of what I wanted to do, no matter what I wanted to do, was already implemented in Perl modules. Python, in contrast, had a a much, much smaller collection of stuff available. Despite certain nice features in Python, the abundance of pre-existing native functionality in Perl won the day for me.
One could argue that Perl functionality can always be called by other languages, but I have extensive experience in mixed-language programming (C/FORTRAN, C++/Java and Perl/C++) and don't really want to deal with the debugging nightmare that it often entails. So given that I could do everything I wanted to in Perl and still live by Booch's Rule 122 ("Never write code unless you absolutely positively must"), Perl was the clear choice.
The only likely replacement for Perl is Perl, as Perl6 will be able to draw on the huge community of Perl developers who have a vested interest in keeping the language alive and flourishing, and it is very likely that debugging from Perl6 into Perl5 will be relatively seamless.
When I took galactic astronomy in grad school fifteen years ago we were taught that the Milky Way may be a barred spiral--it was considered an open question with ambiguous evidence. I specifically recall this as it was a source of jokes along the lines of, "Of course there's a bar in the Milky Way! Now let's go to the pub."
This work looks like it continues to push the bulk of the evidence in the same direction, but you have to understand that the number of firm conclusions you can draw from a single experiment is, on average, far less than one.
It's worth pointing out that the history of medical research can be summarized as: almost everything works well in glass, almost nothing works well in life. There was, for example, a brief fad for hyperbaric oxygen in radiotherapy, which was driven by the observation that cancer cells in a Petri dish become much more radio-sensitive when exposed to pure O2 at high pressure. In the body, unfortunately, oxygen abundance is so heavily regulated that the effect is nil.
Toxicity, as other posters have pointed out, is also a major issue.
However, the only way to find the small percentage of things that work well in vivo is to do the empirical research. This requires long-term dedication and a willingness to follow up a lot of blind alleys, hopefully adding something to the sum of human knowledge along the way.
I helped judge the Canada-Wide Science Fair a few years ago, and the person my judging team ranked the highest had set himself precisely this problem: how do you really calculate the trajectory of a spacecraft from Earth to Mars? His solution was a wonderful exploration of the gory details of the problem--he had parts of the orbit that could be approximated reasonably in closed form (basically when the spacecraft was far away from everything, especially Jupiter) and other bits where there were three-body and more calculations.
He understood error estimation and the importance of computing the same quantity several different ways so that they act as a check on each other. He also had modeled aspects of the spacecraft itself, the rotational moments, effects of changing fuel mass, etc, etc, etc. In short, he understood that science is more of an art than a science. It was really nice work.
This is pretty much my reaction, and I have a similar background.
It has been known for a long time that quantum information can be negative. But no one has known how to interpret it. These guys are giving one possible interpretation out of the infinitely many possible ones. It is a good interpretation as it has some operational significance, but I've always found interpretive papers to be less than satisfying as science (which is why I've never published one, despite having some interesting ones.)
They are also almost certainly catering to popular misunderstanding in the same way the quantum "teleportation" people do. Use of common terms in a way that you know is going to be misinterpreted is bad science, does the public a disservice, and violates the scientist's obligation to spread truth and understanding rather than obscurity and confusion.
The leisurely pace of the book is one of its many delights, as is her precise grammar. It's like drifting down a peaceful river on a sunny afternoon. Not what you'd want if you're in the mood to shoot the rapids, but a very pleasant experience if you're in the right mood.
The fabulous thing about the nominations is the sheer diversity of talent--you'd be hard-pressed to get further from JS&MN than "The Algebrist" (or anything else by Iain M. Banks.) I'm not a big Banks fans--his language is beautiful but his stories are contrived and stupid. Still, some people like that, and it's good to see nominee list that covers such a huge span.
In fact, this would be equivalent to admitting effects without a cause. says the late Pope.
But any rational observer of the world admits effects without cause. Not only are effects without cause central to the quantum mechanical view of the world, they are also implicit in the Newtonian view.
Take, for example, the configuration that John Norton discusses in his paper "Causation as Folk Science". He considers a point mass resting atop a domed surface of section h=(2/3g)r^(3/2), where h is the distance from the central peak of the dome and r is the radial co-ordinate. g is a numerical constant equal to the acceleration of gravity but with dimension set to make the units work out.
At t=0 set r=0, and wait. The motion has two classes of solution. In one, the mass sits still forever. In the other, the mass begins a spontaneous (uncaused) motion down the slope in an arbitrary (uncaused) direction at an arbitrary time T.
While the details of Norton's analysis are incorrect, he is correct in pointing out a class of Newtonian systems that are in "convergently unstable equilibrium". These are systems in which the time-reversed motion contains solutions wherein a mass comes to absolute rest at the end of its motion.
In the case of the dome described above, a point mass sent up the dome with the correct velocity will come to a stop at the top (this is not the case for a spherical dome, where the time-reversed situation does not converge on zero velocity). But in those cases where it does, then obviously the forward motion is also valid, and that is precisely that case where the point mass spontaneously starts moving at an arbitrary time.
Ergo, the late Pope is simply wrong to suggest that we should not admit effects without causes, and his argument falls to bits on this basis, as do all arguments for the necessity of an intelligent designer. The existence of motion does not imply a mover. The existence of order does not imply an orderer. The late Pope implied the existence of these based on an argument from falacious premises: that to have an effect there must be a cause. It is not a matter for philosophical debate but a matter of empirical fact that this premise is false.
Cheap and fully functional = means it will take a long, long, long, long time for the average and inexpensive programmers to build it
Unfortunately, cheap and fully functional just isn't an option--as your own example suggests, it'll take average programmers a long time to get to fully functional, which will not only require you to pay their salaries for a long time, it'll get you to market long after the competition has released their product.
Nothing is cheaper than senior developers. A good senior developer can produce much more code (covering more function points or whatever measure of external utility you care to name) that will be lower maintenance in much less time than a junior developer. But even the best senior developers only cost a few times what a junior developer costs.
Economically, it makes sense to hire as many senior people as possible, because they'll be ten times more productive at twice the price.
The units and dimensions in this thread are killing me.
Thrust in kg?
Isp in seconds? Especially when appearing in the same sentence as fuel density (correctly) stated in kg/m^3... No wonder people think rocket science is hard.
I know these are the common conventions of the field, but they're a confusing mix of imperial, metric, and just plain wrong.
It's extremely sad that 14 people had to die to for NASA to learn a lesson that was obvious to some in the 80's: HLLVs should be used for cargo, smaller winged vehicles for crew. People like Jerry Pournelle and IIRC David Brin were pointing this out at least as early as '85, probably earlier, and they were not alone in making this point.
To the clever fellow who modded this a troll: post-9/11, Canada actually briefly had a "Committee for Public Safety", which was hastily renamed (much to the disappointment of those of us who found it a bloody amusing name for an anti-terrorist organization) when some clever dick pointed out the historical connotations.
For those who are ignorant of history: France's revolutionary Committee for Public Safety was itself what would today be characterized as a terrorist organization--their rule is even called "the Terror" in French history books. And they did, if memory serves, revise the calendar, so for example the month around mid-summer became "Thermidor".
On an unrelated note, despite what some others in this thread have suggested, I think any humour in comments is a Bad Thing. Some poor maintenance coder, whose first language may not be English and who may not have the cultural background to appreciate the humour, could have a very hard time sorting out the humour from the important stuff.
This can also be an issue with slang, which changes over time. The slang that a crusty old bastard like me is likely to use will be incomprehensible to a 20-something new hire, and her slang would be equally incomprehensible to me.
So dull, characterless, direct, literal, professional comments are the only way to go.
Re:And this benefits us how?
on
19 million Amps
·
· Score: 1
The "tuna can" is more likely to be vapourized. One of the goals of tests like this is to determine the properties (particularly radiative opacities) of extremely hot, dense plasmas. A spin-off benefit would be a better understanding of the physics of the solar core, if/when the numbers are declassified.
Funnily enough, R is an excellent example of a bogus constant. Not because it's derived, but because it's obscurantist. The ideal gas law is a hell of a lot clearer if you write it:
P = n*kb*T = N*kb*T/V
where kb is Boltzmann's constant. R is something like kb/Ao, and Avagadro's number (12 g upon the mass of the proton in grams) is an empirical hack that should have been dropped from the cannon a hundred years ago.
Slashdot Mirror
However, p + B11 -> 3He is not the only reaction to occur, but I don't know what consequences to expect from that.
Neutrons, like the poor and nutjob enviros, will always be with us. Depending on contaminants (10B is a problem, I believe) and wall materials, the neutron production rate can be made significantly lower than the fusion rate in pB fusion.
Typically a ratio of less than 1% is considered "aneutronic", although I still wouldn't want to stand too close to such a reactor. However, production of radioactive waste, which is expected to be much lower in fusion plants due to the preponderance of low-Z materials, scales linearly with nuetron production, so the waste levels from 1% ratio reactors will be 100 times lower than from conventional D/T fusion.
My dealings with Vonage were not dissimilar. They've still never paid me what they owe me, although my credit card company successfully challenged the "cancelation fee" they charged me when I found that they didn't have local numbers in my area (despite the fact that I checked on that specifically when signing up.)
So I kinda do hope they go public--it'll be an opportunity to make more than the amount they owe me, as this has all the makings of a great short-term investment: a rapidly-growing company that's the leader in the "next big thing", where no one wants to get left behind even though no one knows how to make money at it.
Look at Philo T. Farnsworth and RCA
Yes, do. Farnsworth had clear priority on filing date. RCA engineers read his patents, visited his lab and discussed his patents with him--which he felt free to do because he had patent protection--and then mined old notebooks for things that they could claim were sufficiently similar to Farnsworth's work to give them priority. Having tied him up in legal challenges, they then proceeded to steal his ideas, keeping him stalled until after his patents had expired.
Under first-to-file they would have had a much larger legal incentive to license Farnsworth's patents. The whole legal smoke-screen that RCA used was dependent on first-to-invent.
The book, "The Last Lone Inventor" is a very good history of Farnsworth's tragedy.
I wonder if the tunneling you describe is just one more example of phase speed vs group speed, or if it's actually negative impedance (whatever that means).
I can't provide references off the top of my head, but tunneling occurs in such a way that no information is transmitted at velocities greater than c. One of the early quantum papers--from Phys. Rev. in 1929 or thereabouts--addresses this topic by doing a numerical solution to the time-dependent Schrodinger Equation for a wave-packet incident on a rectangular barrier. It's all 1D, but the bottom line is that no usable information is available prior to when it would be available if the barrier were not in place.
The thing to realize is that the time-development of the wave-packet is perfectly ordinary under the barrier: the wave packet propogates toward the barrier, interacts with it, and propogates past it. The basics of the time-evolution are the same regardless of whether or not the particle the wave-packet describes has negative energy under the barrier. The only thing that is different is that the solution to the wave equation under the barrier is a real exponentential rather than a complex exponentional.
So yeah, if you like, the group velocity is always c or less, regardless of what the phase velocity needs to be to match the boundary conditions on the far side of the barrier.
The original poster was making a well-known critique of evolutionary just-so stories. I've made it myself, and never felt required to give attribution (as he has done in a follow-up post.) His point stands on its own, and does not require any authority to back it up.
Replacing "stories" with "theories" won't do, because a story is not a theory, and a theory is not a story. If that replacement were made the post would be about something different.
Non-predictive just-so stories are the bane of evolutionary biology, and especially evolutionary psychology, which is viewed by some serious researchers (myself included) as hardly more than a collection of such unjustified yet somehow plausible hand-wavings:
http://www.obgyn.net/newsheadlines/headline_medic
Rockets cost ~$1000/kg to get to LEO (the space shuttle costs ten times that). A space elevator will lift the same to GEO for a fraction of the cost. The energy required (estimated conservatively) is about 150 MJ/kg, or about 50 kWh/kg. Energy prices currently run 5 to 10 cents per kWh, so we're talking an energy cost of about $5/kg. Let's say the total cost per kg for the space elevator is five times that, in keeping with other modes of transportation, for a total cost of $25/kg. It could easily be lower than that.
So if a space elevator cost a trillion dollars (enough capital for 4000 shuttle flights) it would take about a billion kg lifted to make the difference, although again, this is lift to GEO, not LEO, so I'm being very unfair to the space elevator. This is equivalent to 35,000 shuttle flights with full payload (to LEO).
Bottom line: the space elevator won't be built until the cost is well under a hundred billion dollars, but this is quite reasonable. There is no reason to believe that a trillion dollars is required. Most of the cost is in the rockets to carry the first assemblers up to GEO with sufficient material to run the first strand down to Earth. After that, assembly can be done from the ground.
So the relatively low cost of rockets is actually going to make the space elevator more likely in the long run, not less.
http://en.wikipedia.org/wiki/Oliver_Heaviside
Oliver Heaviside is one of the forgotten men of science, much like Philo T. Farnsworth (inventor of the electronic television) is one of the forgotten men of engineering.
As well as casting Maxwell's equations in their modern (vector) form, he contributed to work in relativity, and if memory serves first wrote down E=mc^2 in 1892. David Bohm's book on special relativity covers this in considerable detail.
This is not to diminish the contribution of Einstein, who worked mostly independently of previously known results, but to make it clear that there were others who set the stage for Einstein's great performance.
The fundamental contribution of Einstein was his ability to show that results that had previously been derived by people like Heaviside and Lorentz with great difficulty from an electro-mechanical dynamical model of the electron could be generalized and proven very simply as a result of a purely kinematic invariance.
Outside of a very restricted park environment I can see a serious potential for tragedy here.
What are the odds of the non-native species staying inside a "very restricted park environment" forever?
So why not release them into the wild now, and get the inevitable over with? Regardless of whether the effects of release into the wild will be good or bad, importation of breeding pairs of environmentally-compatible species into North America is equivalent to the release of those species into the wild, because we can be certain that they will be released into the wild ("by accident") at some time in the future.
The specific nature of the "accident" is unpredictable, but the fact that there will be an unintended release is certain.
The reserve will be protected by a 50 foot fence
Why bother with a fence? The animals are certain to get loose. Given sufficient time, the outcome is a foregone conclusion.
So the question for anyone proposing anything like this is: "Given that you are committed to releasing these animals free and uncontrolled into the wild, why are you not doing so immediately? What purpose is the fence supposed to serve?"
Any time any environmentally compatible non-native species is imported to any area for any reason it will always eventually get loose, breed in the wild, diplace local species and disrupt the local ecology.
Now, the disruption of the native ecosystem may or may not be a "good thing" from a human/economic point of view. Nature introduces new species all the time, and sometimes they turn out to benefit (some) humans. But for humans to play at introducing new species as if they had any control of the process once the critters get loose is simply irresponsible.
I believe that CPAN is one of the major (if not the only) things keeping Perl alive and well.
My own experience suggests this is absolutely true. I learned a bit of Perl in 2000, then had a look at Python, and realized that 90% of what I wanted to do, no matter what I wanted to do, was already implemented in Perl modules. Python, in contrast, had a a much, much smaller collection of stuff available. Despite certain nice features in Python, the abundance of pre-existing native functionality in Perl won the day for me.
One could argue that Perl functionality can always be called by other languages, but I have extensive experience in mixed-language programming (C/FORTRAN, C++/Java and Perl/C++) and don't really want to deal with the debugging nightmare that it often entails. So given that I could do everything I wanted to in Perl and still live by Booch's Rule 122 ("Never write code unless you absolutely positively must"), Perl was the clear choice.
The only likely replacement for Perl is Perl, as Perl6 will be able to draw on the huge community of Perl developers who have a vested interest in keeping the language alive and flourishing, and it is very likely that debugging from Perl6 into Perl5 will be relatively seamless.
When I took galactic astronomy in grad school fifteen years ago we were taught that the Milky Way may be a barred spiral--it was considered an open question with ambiguous evidence. I specifically recall this as it was a source of jokes along the lines of, "Of course there's a bar in the Milky Way! Now let's go to the pub."
This work looks like it continues to push the bulk of the evidence in the same direction, but you have to understand that the number of firm conclusions you can draw from a single experiment is, on average, far less than one.
It's worth pointing out that the history of medical research can be summarized as: almost everything works well in glass, almost nothing works well in life. There was, for example, a brief fad for hyperbaric oxygen in radiotherapy, which was driven by the observation that cancer cells in a Petri dish become much more radio-sensitive when exposed to pure O2 at high pressure. In the body, unfortunately, oxygen abundance is so heavily regulated that the effect is nil.
Toxicity, as other posters have pointed out, is also a major issue.
However, the only way to find the small percentage of things that work well in vivo is to do the empirical research. This requires long-term dedication and a willingness to follow up a lot of blind alleys, hopefully adding something to the sum of human knowledge along the way.
--Tom
I helped judge the Canada-Wide Science Fair a few years ago, and the person my judging team ranked the highest had set himself precisely this problem: how do you really calculate the trajectory of a spacecraft from Earth to Mars? His solution was a wonderful exploration of the gory details of the problem--he had parts of the orbit that could be approximated reasonably in closed form (basically when the spacecraft was far away from everything, especially Jupiter) and other bits where there were three-body and more calculations.
He understood error estimation and the importance of computing the same quantity several different ways so that they act as a check on each other. He also had modeled aspects of the spacecraft itself, the rotational moments, effects of changing fuel mass, etc, etc, etc. In short, he understood that science is more of an art than a science. It was really nice work.
This is pretty much my reaction, and I have a similar background.
It has been known for a long time that quantum information can be negative. But no one has known how to interpret it. These guys are giving one possible interpretation out of the infinitely many possible ones. It is a good interpretation as it has some operational significance, but I've always found interpretive papers to be less than satisfying as science (which is why I've never published one, despite having some interesting ones.)
They are also almost certainly catering to popular misunderstanding in the same way the quantum "teleportation" people do. Use of common terms in a way that you know is going to be misinterpreted is bad science, does the public a disservice, and violates the scientist's obligation to spread truth and understanding rather than obscurity and confusion.
The leisurely pace of the book is one of its many delights, as is her precise grammar. It's like drifting down a peaceful river on a sunny afternoon. Not what you'd want if you're in the mood to shoot the rapids, but a very pleasant experience if you're in the right mood.
The fabulous thing about the nominations is the sheer diversity of talent--you'd be hard-pressed to get further from JS&MN than "The Algebrist" (or anything else by Iain M. Banks.) I'm not a big Banks fans--his language is beautiful but his stories are contrived and stupid. Still, some people like that, and it's good to see nominee list that covers such a huge span.
In fact, this would be equivalent to admitting effects without a cause. says the late Pope.
But any rational observer of the world admits effects without cause. Not only are effects without cause central to the quantum mechanical view of the world, they are also implicit in the Newtonian view.
Take, for example, the configuration that John Norton discusses in his paper "Causation as Folk Science". He considers a point mass resting atop a domed surface of section h=(2/3g)r^(3/2), where h is the distance from the central peak of the dome and r is the radial co-ordinate. g is a numerical constant equal to the acceleration of gravity but with dimension set to make the units work out.
At t=0 set r=0, and wait. The motion has two classes of solution. In one, the mass sits still forever. In the other, the mass begins a spontaneous (uncaused) motion down the slope in an arbitrary (uncaused) direction at an arbitrary time T.
While the details of Norton's analysis are incorrect, he is correct in pointing out a class of Newtonian systems that are in "convergently unstable equilibrium". These are systems in which the time-reversed motion contains solutions wherein a mass comes to absolute rest at the end of its motion.
In the case of the dome described above, a point mass sent up the dome with the correct velocity will come to a stop at the top (this is not the case for a spherical dome, where the time-reversed situation does not converge on zero velocity). But in those cases where it does, then obviously the forward motion is also valid, and that is precisely that case where the point mass spontaneously starts moving at an arbitrary time.
Ergo, the late Pope is simply wrong to suggest that we should not admit effects without causes, and his argument falls to bits on this basis, as do all arguments for the necessity of an intelligent designer. The existence of motion does not imply a mover. The existence of order does not imply an orderer. The late Pope implied the existence of these based on an argument from falacious premises: that to have an effect there must be a cause. It is not a matter for philosophical debate but a matter of empirical fact that this premise is false.
Cheap and fully functional = means it will take a long, long, long, long time for the average and inexpensive programmers to build it
Unfortunately, cheap and fully functional just isn't an option--as your own example suggests, it'll take average programmers a long time to get to fully functional, which will not only require you to pay their salaries for a long time, it'll get you to market long after the competition has released their product.
Nothing is cheaper than senior developers. A good senior developer can produce much more code (covering more function points or whatever measure of external utility you care to name) that will be lower maintenance in much less time than a junior developer. But even the best senior developers only cost a few times what a junior developer costs.
Economically, it makes sense to hire as many senior people as possible, because they'll be ten times more productive at twice the price.
The units and dimensions in this thread are killing me.
Thrust in kg?
Isp in seconds? Especially when appearing in the same sentence as fuel density (correctly) stated in kg/m^3... No wonder people think rocket science is hard.
I know these are the common conventions of the field, but they're a confusing mix of imperial, metric, and just plain wrong.
It's extremely sad that 14 people had to die to for NASA to learn a lesson that was obvious to some in the 80's: HLLVs should be used for cargo, smaller winged vehicles for crew. People like Jerry Pournelle and IIRC David Brin were pointing this out at least as early as '85, probably earlier, and they were not alone in making this point.
To the clever fellow who modded this a troll: post-9/11, Canada actually briefly had a "Committee for Public Safety", which was hastily renamed (much to the disappointment of those of us who found it a bloody amusing name for an anti-terrorist organization) when some clever dick pointed out the historical connotations.
For those who are ignorant of history: France's revolutionary Committee for Public Safety was itself what would today be characterized as a terrorist organization--their rule is even called "the Terror" in French history books. And they did, if memory serves, revise the calendar, so for example the month around mid-summer became "Thermidor".
My favourite is:
x = 5;
On an unrelated note, despite what some others in this thread have suggested, I think any humour in comments is a Bad Thing. Some poor maintenance coder, whose first language may not be English and who may not have the cultural background to appreciate the humour, could have a very hard time sorting out the humour from the important stuff.
This can also be an issue with slang, which changes over time. The slang that a crusty old bastard like me is likely to use will be incomprehensible to a 20-something new hire, and her slang would be equally incomprehensible to me.
So dull, characterless, direct, literal, professional comments are the only way to go.
The "tuna can" is more likely to be vapourized. One of the goals of tests like this is to determine the properties (particularly radiative opacities) of extremely hot, dense plasmas. A spin-off benefit would be a better understanding of the physics of the solar core, if/when the numbers are declassified.
Funnily enough, R is an excellent example of a bogus constant. Not because it's derived, but because it's obscurantist. The ideal gas law is a hell of a lot clearer if you write it:
P = n*kb*T = N*kb*T/V
where kb is Boltzmann's constant. R is something like kb/Ao, and Avagadro's number (12 g upon the mass of the proton in grams) is an empirical hack that should have been dropped from the cannon a hundred years ago.
Hey, anyone remember the last bunch of people to mess with the calendar?
Withouth bothering to follow the link, I'd guess that'd be the Committee for Public Safety, yes?
What a nice, anti-terrorist sound that name has.
Is it reasonable for an ISP to censor webpages they don't agree with during contract negotiations?
An ISP is an Internet Service Provider. Telus no longer provides service to the Internet. They provide limited subnet access via Internet protocols.
If I were a Telus customer I'd call 'em up and demand that they give me access to the Internet or give me my money back.