You hadn't made any case beyond vague, unsupported assertions. And you still haven't.
And it appears I won't, 'cause I was not only glib, I was wrong.
Specifically, the dead tree source I got the factoid from seems to have misrepresented (or misunderstood) the sources it cited. The actual facts of the case (all percentages approximate) seem to be:
New fuel rods are 97% U238 (inert) and 3% U235 (active)
Spent rods are 96% U238, 1% U235, 1% Pu (239 & 240), and 3% other
According to their source, the energy obtainable from the Pu is about twice that from U235, and thus the total energy available from the fuel rod is over 99% of the original.
Thus spent fuel is 98% U and contains about the same amount of energy as the new fuel.
However, the tract I got the stat I quoted from got this wrong (saying that less than 1% of the U235 had been used, instead of the correct ~70% figure), and I haven't been able to track down any of the underlying numbers in anything wikipedia grade or higher, I'm considering the whole thing suspect at this point.
Yes, reprocessing makes sense in some contexts (cf France, Japan). However, the detailed figures I cited in support of this position were badly sourced and I retract them.
No "Evil Conspiracy," at least not one deserving the capitalization. The information is widely known, if not widely recognized.
But rereading my post I can see how you might get that idea. The key is I'm counting the plutonium as a source of power and only the high cross-section products as waste.
If the other technologies involved nuclear fission, they'd have the same regulatory hurdles.
Some of the nuclear regulatory practices are unnecessary, sure, but most of it is there for a reason. When dealing with a potentially very dangerous nuclear reaction, it pays off to be extra careful.
What's so special about nuclear fission? Is it somehow better to be killed by (for example) pollution from a coal fired power plant than it would be to be killed by a nuclear plant? Why is it exactly that no one cares that coal fired plants routinely dump radioactive waste into the atmosphere at a rate that would have a nuclear plant shut down in a heartbeat?
If you are worried about safety, all power generating facilities should be held to exactly the same standards. If you are trying to kill one technology in the market place, it should have special rules that only apply to it, while the favored technologies get a pass. Which best describes the present situation?
I'm fairly confident that there won't be a photovoltaic Chernobyl, though.
Nuclear power plants need tremendous oversight in planning, construction, and operation, to make sure public safety doesn't lose out to corporate cost-cutting. Holding a nuclear reactor design "to the same paperwork standards" as a wind turbine would be a disaster.
But a wind turbine isn't the same thing as a nuclear reactor, not by about three orders of magnitude or so. And solar cells are even worse.
If you look at industrial accident statistics, and scale by the necessary factors (e.g. proportional to generated power) the actual loss of life we should expect from wind / solar higher than that from nuclear, even taking into account Chernobyl, Three Mile Island, etc.
It's like the difference between travel by car and by air; air travel is measurably safer than car travel, but occasional air disasters get a lot of media play while the steady stream of traffic fatalities gets quietly ignored.
Likewise, "corporate cost cutting" and "safe wind turbines" don't mix well either.
"Waste" disposal is only a problem because we refuse to reprocess it like any sane and sensible country would.
Huh? You mean somebody (and I mean somebody in the real world) has found a use for the byproduct of nuclear fission? Last I heard, just finding a place to store it was a major problem. And by "storing it" I mean keeping it secure for centuries.
This is not a new discovery. These "byproducts" are just the unused fuel (>99%) and the accumulated actual byproducts (<1%). By reprocessing them (a technology available for decades, but presently outlawed) the unused fuel could be used and the byproducts (many of which have commercial uses) could be used or stored.
The storing it for centuries canard is equally bogus. The dangerous, highly radioactive stuff breaks down quickly, while the long lived residual is far more stable (that's why it's long lived) and thus much less dangerous. Conflating the two is disingenuous at best.
Carter decided to avoid breeder reactors in part because they can blow up and new fuel is cheep enough that reprocessing is not that big a deal.
I'll agree that Carter knew a lot about nuclear power, and for that reason I doubt that he thought that breeder reactors can blow up. 'cause it isn't true.
And while new fuel may be cheap the real question is how much does storing the fuel after extracting less than 1% of the energy cost?
This is particularly true for advocates of nuclear power (waste disposal, weapons proliferation, high costs, high NIMBY factor)
*Sigh*
"Waste" disposal is only a problem because we refuse to reprocess it like any sane and sensible country would. If our government weren't being run by the fossil fuel industry we'd call them "fuel reserves" instead of "waste."
Just because they "nuclear power" and "nuclear weapons" both have the word "nuclear" in them doesn't mean that having one gives you the other. They are radically different technologies. Compared to the other hurdles, having access to a nuclear power plant wouldn't give you much of a leg up on developing a nuclear weapon.
The high costs are largely due to the regulatory environment designed to favor fossil fuels.
Ditto the NIMBY effect. Having studied the effects, I'd much rather live near a nuclear power plant that a coal fired plant. Not only would I have less CO2, mercury, etc. to worry about, the nuclear plant poses a much lower risk of radiation exposure.
The real reason is that they grew up in the 50's and have therefore formed a hard connection in their heads that anything with "nuclear" in it means the destruction of all mankind.
Apparently, if you were making a movie in the 1950s & 60s you could get supplementary funding from the fossil fuel industry for including an anti-nuclear subtext. While it may seem crude by today's product placement and mass media manipulation standards, it seems to have been an effective use of their money.
He only doesn't like nuclear power because of them there terr'ists.
I believe these statements are also relevant:
* "nuclear emits about 25-times more carbon and air pollution than wind energy"
* "coal and nuclear energy plants take much longer to plan, permit and construct than do most of the other new energy sources"
Well given that he computes the carbon footprint of nuclear by dragging things like "terrorists could steal the fuel to make a bomb which could be used in a city which would burn and release lots of CO2," and that one of the reasons nuclear plants take so long to license is the regulatory hurdles designed in part to prevent terrorists from doing just that, I'd say the GP's summary, while glib, was accurate.
It mostly takes so long because of all the regulatory hurdles. If the other technologies were held to the same paperwork standards, they'd take as long (or longer) to get online.
Storing that nuclear waste for the next million years is the problem. Who wants that stored in their backyard?
The only reason most of it "needs" to be stored is regulatory. 99% of the so-called primary wastes are perfectly usable as fuel for future cycles. If reprocessing were permitted (like in France, etc.) most of our "nuclear wastes" would become "nuclear fuel reserves."
Almost all of what's left is either commercially valuable / recyclable or harmless.
The nuclear waste "problem" is a creation of our fossil fuel industry driven political system.
I love how it's dismissed out of hand because of the bogeyman argument.
TERRORISM!!!!!! Oh crap.
We better rule out anything that is efficient and can be used RIGHT NOW.
It's worse than that. They estimated the carbon footprint for nuclear based on assuming that 1) nuclear power == nuclear weapons, and 2) terrorists will get these and 3) they will use them in a city which will then 4) catch fire, 5) releasing lots of C02. So therefore nuclear isn't an ecologically sound solution.
Blech.
Why don't these people just admit that the real reasoning is of all the listed options 1) nuclear power could actually replace fossil fuels, which would 2) hurt profits, so it is 3) evil and must be stopped?
Despite the common slashdot groupthink on this subject, there are indeed quite a few very intelligent people that also hold religious beliefs and don't let those religious beliefs muddy up the science.
Let's check that argument. First off, the embedded claim "there are indeed quite a few very...etc." is undoubtedly true. Undoubtedly to the point that even the slashdot groupthink is unlikely to challenge it. So using the "despite" construction is a little disingenuous. You might as well have said:
Despite the fact that it is raining, seven is prime.
Sounds silly, no? So why did you use that construct? Because you were wanting to misrepresent the groupthink position, and then take down the straw man. And thus imply that the groupthink position was wrong.
The problem is, this is logically equivalent to claims like the following:
Despite the common slashdot groupthink on this subject, quite a few brilliant scientists believed in astrology without it diminishing the quality of their work.
Despite the common slashdot groupthink on this subject, many productive mathematicians drink heavily and still get published.
Despite the common slashdot groupthink on this subject, popular file systems can be designed by cold blooded murderers.
You see the problem here. It is possible for someone to do something significant despite voluntarily taking an enormous handicap, but no one would suggest doing such things as a step towards achieving greatness. That's were the "despite" really belongs. The succeeded despite the handicaps, not because of them.
If you want to write a successful file system, killing your wife is not the best place to start. If you want to become the next Newton, taking up astrology isn't the best place to start. And if you want to be a scientist, religion isn't the best place to start. Yes, you can do it. But you'd make things a whole lot easier on your self if you ditched the handicaps at the outset.
That is the slashdot groupthink position, and your argument didn't touch it.
I'll look past your abusive tone and know it all attitude and just address your main point.
You claim that it is not possible to bound stack usage in recursive algorithms. This is not true. By requiring tail recursion it can be limited to exactly zero bytes over that used by a non-recursive algorithm. By proper use of accumulators, the vast majority of useful algorithms can be converted to a tail recursive form.
Even without this, recursion depth is generally bounded by some property of the data structure, and can be limited to the same extent as any other property with a similar dependency. Def Stan explicitly acknowledges this: "recursion should not be used in the implementation. unless strict bounds on the depth of recursion can be defined and hence it can be shown that the permitted memory usage will not be exceeded."
Note that this isn't any harder (or more stringent) a limitation as the similar requirements on buffer size, queue length, loop termination, etc. all of which can vary in exactly the same way.
Finally, non-deterministic has a specific meaning, and it isn't the one you seem to be using. Something is non-deterministic if (and only if) it can't be determined in principle, by any one, no matter how clever. You seem to be using it to describe something which is hard to determine by people with your mindset, regardless of how tractable it may be in general.
There's a big difference between "I can't figure it out" and "it's non-deterministic." Recognizing the former doesn't in and of itself justify asserting the latter.
"Actually, I can see a whole lot of potential parallelism in compiling C. (Think parallelism)."
That's about what you said.
*laugh* Not quite, but I can see how you could take it that way.
What I was thinking was that you wanted to go massively parallel you could split the source up into lots of chunks and do various transformations on them, then combine the results. Repeat with the AST.
Preprocessing, I think, hasn't been easy to parallelize -- I don't think distcc does it.
It should be possible to do a whole lot with speculative parallelism.
Suppose lines are categorized like so: (A) passed unchanged through the preprocessor, (B) entirely consumed by the preprocessor as part of a definition, (C) internally modified as part of a macro expansion, (D) something more complicated. It's my contention that most lines wouldn't fall in class (D). In fact, I'd say that if you assumed (A) and then (in parallel) tested for (B), (C), or (D) with minimally disruptive ways of handling (B) and (C) you'd gain enough to pay for the rare, more expensive cases of (D) and still come out ahead.
I can't find a reading of this claim that isn't utter nonsense. Are you saying that it is inherently impossible to determine the results of any recursive calculation? Or that it is inherently impossible to prove a recursive calculation terminates? Or set a bound on its execution time? 'cause all of these are clearly wrong. Are you claiming that recursive calculations necessarily involve some sort of quantum weirdness? That seems hard to believe.
You seem to have some serious misunderstandings here.
Pure functional programming removes all side effects.
Yes, at the expense of a copy-everything in sight, use zillions of message channels,
Uh, no. By removing side effects functional programming removes the need to copy anything. If I'm trying to evaluate f(X) + g(X) for some complicated X, f, and g by evaluating f(X) and g(X) in parallel and adding the results, I don't need two copies of X because I know that neither f nor g will modify it. That's the whole point.
FP is not just counterintuitive and hard to learn but it is also non-deterministic, meaning that it is not well-suited to mission critical systems.
It only seems counter intuitive if you've swallowed the procedural programming paradigm and adopted it as your own to the point where you've forgotten how counter intuitive "X = X + 1" seemed at first.
And saying it's non-deterministic is just nuts. Sure, you could add non-deterministic semantics to any language, but there's nothing inherently non-deterministic about functional programming. In fact, I think you'd typically have to work a lot harder to make a functional language non-deterministic.
FP is a continuation of the same process/thread mentality that has gotten the industry into this mess in the first place.
FP has nothing to do with threads, apart from the fact that functional programs could be executed by a large number of threads in parallel (or independent cores, or...?) without changing the outcome. And what exactly is the mess we're in? I can't think of another industry that has succeeded so spectacularly in such a short time.
"enfatuated" isn't a word.
The blog you link to proposes a solution that is arguably worse on every issue you raise.
It isn't a broken business model. It isn't a business model.
Saying the open source business model is broken is like saying open source doesn't work as a cheese sauce. It also isn't a very effective screw driver. On the other hand, I have yet to hear a business model you can dance to.
Yes, but there is (or at least was) more to it than that.
The model is/was supposed to house all of the details about how things interact, without regard to how you want to look at them (views) or mess with them (controllers).
Nowadays, models are more times than not just a sort of glorified persistence layer, describing the data in static terms and lacking the juicy details of how the data dances.
I'm glad I'm not the only one. When I first came across the web-based use of MVC I kept scratching my head and alternating between "WTF?" and "You keep using that word; I do not think it means what you think it does." After a while I realized that the web framework community had just latched onto MVC in a sort of cargo-cult fashion, without regard for it's prior meaning.
Not that it's the first time such a thing has happened. Think "structured" and "object oriented" or even "secure." For that matter, consider the fact that "Real" with the little swirly (as applied to cheese) is a trademark, not an adjective--the American Dairy Association could market tofu as "Real(tm) Cheese" if they wanted to.
The problem comes in when you start assuming that things that were true of the original use of the word are still true under the new use. Web-frameworks are MVC in exactly the sense that partially hydrogenated vegetable oil is cheese.
no, it's not like that. nuclear isn't cost effective. It requires more money to make it than it produces. If one equates money to fossil fuel - as is the basis of much of our economy - it isn't fuel efficient. Nuclear requires massive public subsidy.
Bullocks. The fossil fuels industry gets a massive public subsidy (everything from dedicated infrastructure to wars on demand), while the nuclear industry is hampered by massive roadblocks erected at the public expense. It isn't surprising, given who has the money to buy legislation. Claiming (as you do) that the situation is reversed is getting into The Big Lie territory.
Level the playing field and then look at which is cost effective. Require that fossil fuel plants safely store (and track) all of their waste products forever. Make them remove the coal (or oil) after 1% has been burned and call the whole lot waste. Make it a federal crime to try to reprocess the "wastes" to use the remaining 99%.
See how good fossil fuels looked then.
--MarkusQ
P.S.
now we have a generation raised on hollywood movies who don't know where 3 mile island is.
Again with the getting things backwards. Hollywood routinely portrays nuclear power as much more dangerous than it really is. Three mile island is in Pennsylvania. The power plant is still operating (minus one reactor). There was no measurable increase in cancer, and no one died )or even got seriously injured) as a direct result (excluding people who may have been injured in the panic whipped up by the media). It is perfectly safe to go there, and even at the time of the accident the increase in exposure was far less than the natural background.
And why exactly are you comparing two, outdated technologies when you really should be comparing them to solar thermal, photovoltaic, wind, hydro, tidal and geothermal?
Because if you do the numbers you realize that, to replace fossil fuels with solar, wind, or hydro you'd have to devote so much land it'd be an ecological nightmare. Geothermal and tidal might be feasible but the cost of getting to them (building out beyond the coastal ecosystem or drilling down to where it's hot enough to be worthwhile) are far too expensive.
Space-based solar might work, if you could automate production and deployment with lunar materials, but that's still a lot further off than nuclear.
The volume (and mass) of waste per kilowatt hour of power is orders of magnitude lower for nuclear than for fossil fuels.
Yes, but nobody's going to die from inhaling an equivalent mass of CO2 versus, say, a radioactive isotope of cesium. And if somebody releases a thousand pounds of CO2 over a populated city, I doubt anyone would notice... A thousand pounds of any radioactive compound and you're talking major ecological disaster. (and yes, everything is radioactive, for those in the peanut gallery... you know what we're talking about here though)
Nice dodge, but factually and structurally unsound. 1) we aren't talking about "equivalent masses" here by a couple orders of magnitude, that's the whole point; 2) cesium boils at 1240F, so if you're breathing cesium vapor you've got more urgent things to worry about than the radioactivity; 3) more people actually die each year from CO2 inhalation than radiation poisoning; 4) thousands of pounds of radioactive carbon (in carbon dioxide) are regularly dumped into the air by the burning of fossil fuels...there's more, but you get my point.
The bulk of nuclear wastes can be cost effectively reprocessed to make more fuel,
The bulk of nuclear fuel can only be reprocessed if and only if the plant was designed with that in mind. Most currently in production aren't breeder plants because they can be used for weapons programs. To say it in laymans terms... They've been neutered. They break the uranium down into isotopes that don't necessarily lend themselves to reprocessing in several common configurations. As well, breeder reactors are more expensive to operate.
Wrong. Just flat wrong. 99% of the fuel is reusable, once the remaining 1% has been removed. They do it in France.
Much of the remaining nuclear waste material has a short half-life
Much of it does, but enough of it doesn't and the stuff that doesn't lasts millions of years.
"Lasts millions of years" meaning it sits there and does nothing at all interesting, acting exactly like it would if it weren't radioactive. That's what a long half life means.
The remainder of the nuclear waste material is long-half life solids which, due to the very nature of half lives, aren't very radioactive
...and when you pack enough of it into a confined area, which is what we're doing when we store it... It's still lethal. The Chernobyl disaster area is covered in these "not very" radioactive isotopes. Do you want to live there?
I'd have no problem with it, nor should you if you fly on airplanes. In the "hottest" areas the dosage is down to 250 micro rem / hour, less than half what you get anytime you ride a jet. The vast majority of the area is down to levels on a par with many places (Denver, Cornwall, much of New Mexico, Grand Central Station,etc.) that aren't considered "uninhabitable" by reasonable people.
Slashdot Mirror
And it appears I won't, 'cause I was not only glib, I was wrong.
Specifically, the dead tree source I got the factoid from seems to have misrepresented (or misunderstood) the sources it cited. The actual facts of the case (all percentages approximate) seem to be:
However, the tract I got the stat I quoted from got this wrong (saying that less than 1% of the U235 had been used, instead of the correct ~70% figure), and I haven't been able to track down any of the underlying numbers in anything wikipedia grade or higher, I'm considering the whole thing suspect at this point.
Yes, reprocessing makes sense in some contexts (cf France, Japan). However, the detailed figures I cited in support of this position were badly sourced and I retract them.
--MarkusQ
I'd say of the two, secrecy is the less important requirement and if one of them has to be dropped, it should.
It comes down to a choice between:
Which do you suppose would be harder to rig?
--MarkusQ
No "Evil Conspiracy," at least not one deserving the capitalization. The information is widely known, if not widely recognized.
But rereading my post I can see how you might get that idea. The key is I'm counting the plutonium as a source of power and only the high cross-section products as waste.
--MarkusQ
What's so special about nuclear fission? Is it somehow better to be killed by (for example) pollution from a coal fired power plant than it would be to be killed by a nuclear plant? Why is it exactly that no one cares that coal fired plants routinely dump radioactive waste into the atmosphere at a rate that would have a nuclear plant shut down in a heartbeat?
If you are worried about safety, all power generating facilities should be held to exactly the same standards. If you are trying to kill one technology in the market place, it should have special rules that only apply to it, while the favored technologies get a pass. Which best describes the present situation?
--MarkusQ
But a wind turbine isn't the same thing as a nuclear reactor, not by about three orders of magnitude or so. And solar cells are even worse.
If you look at industrial accident statistics, and scale by the necessary factors (e.g. proportional to generated power) the actual loss of life we should expect from wind / solar higher than that from nuclear, even taking into account Chernobyl, Three Mile Island, etc.
It's like the difference between travel by car and by air; air travel is measurably safer than car travel, but occasional air disasters get a lot of media play while the steady stream of traffic fatalities gets quietly ignored.
Likewise, "corporate cost cutting" and "safe wind turbines" don't mix well either.
--MarkusQ
This is not a new discovery. These "byproducts" are just the unused fuel (>99%) and the accumulated actual byproducts (<1%). By reprocessing them (a technology available for decades, but presently outlawed) the unused fuel could be used and the byproducts (many of which have commercial uses) could be used or stored.
The storing it for centuries canard is equally bogus. The dangerous, highly radioactive stuff breaks down quickly, while the long lived residual is far more stable (that's why it's long lived) and thus much less dangerous. Conflating the two is disingenuous at best.
--MarkusQ
I'll agree that Carter knew a lot about nuclear power, and for that reason I doubt that he thought that breeder reactors can blow up. 'cause it isn't true.
And while new fuel may be cheap the real question is how much does storing the fuel after extracting less than 1% of the energy cost?
--MarkusQ
*Sigh*
"Waste" disposal is only a problem because we refuse to reprocess it like any sane and sensible country would. If our government weren't being run by the fossil fuel industry we'd call them "fuel reserves" instead of "waste."
Just because they "nuclear power" and "nuclear weapons" both have the word "nuclear" in them doesn't mean that having one gives you the other. They are radically different technologies. Compared to the other hurdles, having access to a nuclear power plant wouldn't give you much of a leg up on developing a nuclear weapon.
The high costs are largely due to the regulatory environment designed to favor fossil fuels.
Ditto the NIMBY effect. Having studied the effects, I'd much rather live near a nuclear power plant that a coal fired plant. Not only would I have less CO2, mercury, etc. to worry about, the nuclear plant poses a much lower risk of radiation exposure.
--MarkusQ
Apparently, if you were making a movie in the 1950s & 60s you could get supplementary funding from the fossil fuel industry for including an anti-nuclear subtext. While it may seem crude by today's product placement and mass media manipulation standards, it seems to have been an effective use of their money.
--MarkusQ
Well given that he computes the carbon footprint of nuclear by dragging things like "terrorists could steal the fuel to make a bomb which could be used in a city which would burn and release lots of CO2," and that one of the reasons nuclear plants take so long to license is the regulatory hurdles designed in part to prevent terrorists from doing just that, I'd say the GP's summary, while glib, was accurate.
--MarkusQ
It mostly takes so long because of all the regulatory hurdles. If the other technologies were held to the same paperwork standards, they'd take as long (or longer) to get online.
--MarkusQ
The only reason most of it "needs" to be stored is regulatory. 99% of the so-called primary wastes are perfectly usable as fuel for future cycles. If reprocessing were permitted (like in France, etc.) most of our "nuclear wastes" would become "nuclear fuel reserves."
Almost all of what's left is either commercially valuable / recyclable or harmless.
The nuclear waste "problem" is a creation of our fossil fuel industry driven political system.
--MarkusQ
It's worse than that. They estimated the carbon footprint for nuclear based on assuming that 1) nuclear power == nuclear weapons, and 2) terrorists will get these and 3) they will use them in a city which will then 4) catch fire, 5) releasing lots of C02. So therefore nuclear isn't an ecologically sound solution.
Blech.
Why don't these people just admit that the real reasoning is of all the listed options 1) nuclear power could actually replace fossil fuels, which would 2) hurt profits, so it is 3) evil and must be stopped?
--MarkusQ
Let's check that argument. First off, the embedded claim "there are indeed quite a few very...etc." is undoubtedly true. Undoubtedly to the point that even the slashdot groupthink is unlikely to challenge it. So using the "despite" construction is a little disingenuous. You might as well have said:
Sounds silly, no? So why did you use that construct? Because you were wanting to misrepresent the groupthink position, and then take down the straw man. And thus imply that the groupthink position was wrong.
The problem is, this is logically equivalent to claims like the following:
You see the problem here. It is possible for someone to do something significant despite voluntarily taking an enormous handicap, but no one would suggest doing such things as a step towards achieving greatness. That's were the "despite" really belongs. The succeeded despite the handicaps, not because of them.
If you want to write a successful file system, killing your wife is not the best place to start. If you want to become the next Newton, taking up astrology isn't the best place to start. And if you want to be a scientist, religion isn't the best place to start. Yes, you can do it. But you'd make things a whole lot easier on your self if you ditched the handicaps at the outset.
That is the slashdot groupthink position, and your argument didn't touch it.
--MarkusQ
I'll look past your abusive tone and know it all attitude and just address your main point.
You claim that it is not possible to bound stack usage in recursive algorithms. This is not true. By requiring tail recursion it can be limited to exactly zero bytes over that used by a non-recursive algorithm. By proper use of accumulators, the vast majority of useful algorithms can be converted to a tail recursive form.
Even without this, recursion depth is generally bounded by some property of the data structure, and can be limited to the same extent as any other property with a similar dependency. Def Stan explicitly acknowledges this: "recursion should not be used in the implementation. unless strict bounds on the depth of recursion can be defined and hence it can be shown that the permitted memory usage will not be exceeded."
Note that this isn't any harder (or more stringent) a limitation as the similar requirements on buffer size, queue length, loop termination, etc. all of which can vary in exactly the same way.
Finally, non-deterministic has a specific meaning, and it isn't the one you seem to be using. Something is non-deterministic if (and only if) it can't be determined in principle, by any one, no matter how clever. You seem to be using it to describe something which is hard to determine by people with your mindset, regardless of how tractable it may be in general.
There's a big difference between "I can't figure it out" and "it's non-deterministic." Recognizing the former doesn't in and of itself justify asserting the latter.
--MarkusQ
*laugh* Not quite, but I can see how you could take it that way.
What I was thinking was that you wanted to go massively parallel you could split the source up into lots of chunks and do various transformations on them, then combine the results. Repeat with the AST.
It should be possible to do a whole lot with speculative parallelism.
Suppose lines are categorized like so: (A) passed unchanged through the preprocessor, (B) entirely consumed by the preprocessor as part of a definition, (C) internally modified as part of a macro expansion, (D) something more complicated. It's my contention that most lines wouldn't fall in class (D). In fact, I'd say that if you assumed (A) and then (in parallel) tested for (B), (C), or (D) with minimally disruptive ways of handling (B) and (C) you'd gain enough to pay for the rare, more expensive cases of (D) and still come out ahead.
--MarkusQ
I can't find a reading of this claim that isn't utter nonsense. Are you saying that it is inherently impossible to determine the results of any recursive calculation? Or that it is inherently impossible to prove a recursive calculation terminates? Or set a bound on its execution time? 'cause all of these are clearly wrong. Are you claiming that recursive calculations necessarily involve some sort of quantum weirdness? That seems hard to believe.
So what do you mean?
--MarkusQ
Actually, I can see a whole lot of potential parallelism in compiling C. (Think map-reduce).
--MarkusQ
You seem to have some serious misunderstandings here.
Uh, no. By removing side effects functional programming removes the need to copy anything. If I'm trying to evaluate f(X) + g(X) for some complicated X, f, and g by evaluating f(X) and g(X) in parallel and adding the results, I don't need two copies of X because I know that neither f nor g will modify it. That's the whole point.
It only seems counter intuitive if you've swallowed the procedural programming paradigm and adopted it as your own to the point where you've forgotten how counter intuitive "X = X + 1" seemed at first.
And saying it's non-deterministic is just nuts. Sure, you could add non-deterministic semantics to any language, but there's nothing inherently non-deterministic about functional programming. In fact, I think you'd typically have to work a lot harder to make a functional language non-deterministic.
FP has nothing to do with threads, apart from the fact that functional programs could be executed by a large number of threads in parallel (or independent cores, or...?) without changing the outcome. And what exactly is the mess we're in? I can't think of another industry that has succeeded so spectacularly in such a short time.
And so on...did I just feed a troll?
--MarkusQ
It isn't a broken business model. It isn't a business model.
Saying the open source business model is broken is like saying open source doesn't work as a cheese sauce. It also isn't a very effective screw driver. On the other hand, I have yet to hear a business model you can dance to.
--MarkusQ
Yes, but there is (or at least was) more to it than that.
The model is/was supposed to house all of the details about how things interact, without regard to how you want to look at them (views) or mess with them (controllers).
Nowadays, models are more times than not just a sort of glorified persistence layer, describing the data in static terms and lacking the juicy details of how the data dances.
--MarkusQ
I'm glad I'm not the only one. When I first came across the web-based use of MVC I kept scratching my head and alternating between "WTF?" and "You keep using that word; I do not think it means what you think it does." After a while I realized that the web framework community had just latched onto MVC in a sort of cargo-cult fashion, without regard for it's prior meaning.
Not that it's the first time such a thing has happened. Think "structured" and "object oriented" or even "secure." For that matter, consider the fact that "Real" with the little swirly (as applied to cheese) is a trademark, not an adjective--the American Dairy Association could market tofu as "Real(tm) Cheese" if they wanted to.
The problem comes in when you start assuming that things that were true of the original use of the word are still true under the new use. Web-frameworks are MVC in exactly the sense that partially hydrogenated vegetable oil is cheese.
--MarkusQ
Bullocks. The fossil fuels industry gets a massive public subsidy (everything from dedicated infrastructure to wars on demand), while the nuclear industry is hampered by massive roadblocks erected at the public expense. It isn't surprising, given who has the money to buy legislation. Claiming (as you do) that the situation is reversed is getting into The Big Lie territory.
Level the playing field and then look at which is cost effective. Require that fossil fuel plants safely store (and track) all of their waste products forever. Make them remove the coal (or oil) after 1% has been burned and call the whole lot waste. Make it a federal crime to try to reprocess the "wastes" to use the remaining 99%.
See how good fossil fuels looked then.
--MarkusQ P.S.
Again with the getting things backwards. Hollywood routinely portrays nuclear power as much more dangerous than it really is. Three mile island is in Pennsylvania. The power plant is still operating (minus one reactor). There was no measurable increase in cancer, and no one died )or even got seriously injured) as a direct result (excluding people who may have been injured in the panic whipped up by the media). It is perfectly safe to go there, and even at the time of the accident the increase in exposure was far less than the natural background.
Because if you do the numbers you realize that, to replace fossil fuels with solar, wind, or hydro you'd have to devote so much land it'd be an ecological nightmare. Geothermal and tidal might be feasible but the cost of getting to them (building out beyond the coastal ecosystem or drilling down to where it's hot enough to be worthwhile) are far too expensive.
Space-based solar might work, if you could automate production and deployment with lunar materials, but that's still a lot further off than nuclear.
--MarkusQ
Nice dodge, but factually and structurally unsound. 1) we aren't talking about "equivalent masses" here by a couple orders of magnitude, that's the whole point; 2) cesium boils at 1240F, so if you're breathing cesium vapor you've got more urgent things to worry about than the radioactivity; 3) more people actually die each year from CO2 inhalation than radiation poisoning; 4) thousands of pounds of radioactive carbon (in carbon dioxide) are regularly dumped into the air by the burning of fossil fuels...there's more, but you get my point.
Wrong. Just flat wrong. 99% of the fuel is reusable, once the remaining 1% has been removed. They do it in France.
"Lasts millions of years" meaning it sits there and does nothing at all interesting, acting exactly like it would if it weren't radioactive. That's what a long half life means.
I'd have no problem with it, nor should you if you fly on airplanes. In the "hottest" areas the dosage is down to 250 micro rem / hour, less than half what you get anytime you ride a jet. The vast majority of the area is down to levels on a par with many places (Denver, Cornwall, much of New Mexico, Grand Central Station,etc.) that aren't considered "uninhabitable" by reasonable people.
--MarkusQ