"The shuttle did not explode in the common definition of that word... Challenger itself was torn apart as it was flung free of the other rocket components and turned broadside into the Mach 2 airstream. Individual propellant tanks were seen exploding -- but by then, the spacecraft was already in pieces."
Explosion...(2)... "a large-scale, rapid, or spectacular expansion or bursting out or forth" (www.m-w.com)
Coming to peices in a matter of a second or so, after being mysteriously "flung free" of the other rocket components, would ordinarily be called an explosion. Otherwise, we would be left wondering how something really large could come to pieces in a second without exploding, in the ordinary phenomenological sense of the term.
The guy who wrote the article doesn't even follow his own pedantic rules when he describes the orbiter being "flung free". If we are to be pedantic literalists we must acknowledge that it wasn't "flung free", which implies an impulsive force between the external tank, the SRBs and the orbiter. Rather, structural integrity between the various components was lost due to purely areodynamic forces, as the article itself relates.
So let me be the first to debunk the eighth myth regarding what will heretofore be known as "the Challenger aerodynamically-driven rapid disassembly": despite popular belief to the contraray, the orbiter was not "flung free" from the other rocket components, but rather merely followed an independent trajectory governed by purely areodynamic forces.
I have an epistemological question for everyone who supports any form of wiretapping without a warrant: How do you know that the wiretapping is being done for purposes of "anti-terrorism" or to "people the government is suspicious of"?
The purpose of requiring a warrant is that a warrant can only be issued by a court, and the purpose of the court is to examine the truth, or at least the plausibility, of the claims being made to justify the need for a warrant. Without a warrant, without a court, the only answer to my question is, "We know because George Bush or one of his designates says so."
Given the record of the Bush administration on matters of truth, such as the claims regarding WMDs in Iraq and Iraq's support of al Qaeda, it seems to me a bad idea to make the administration's say-so a major plank in your epistemological platform. This is just common sense. No one would recommend trusting one's money blindly to a financial advisor who had lost everything in a major blunder that later turned out to be based on transparently false claims.
What's more, volcanos are one of the processes that set the natural equilibrium, while human emissions are a new component.
What makes volcanic emissions, which intermitently create global catastrophy, part of the "natural equilibrium"? What on Earth is the "natural equilibrium" anyway?
Of all the stupid red herrings in the global warming debate, the idea that there is any distinction between human and non-human sources of greenhouse gasses is the reddest. Terrestrial homeostatis does not care where the gasses are coming from. It only cares how much and on what timescale, and when it happens relative to various other semi-periodic phenomena. The claim that the current human emissions of greenhouses gasses are somehow out of range compared to past non-human greenhouse events is nothing but a transparent attempt to introduce an element of hysteria into a debate that already has far too much of it on both sides.
This claim about human emissions being somehow different from non-human ones seems to me to be an attempt to pre-empt all of the wacko arguments from the other side that deal with non-human greenhouse emmissions. I think a far better approach is to acknowledge all of those sources as important, and agree firmly with our opponents that such sources have been very important in the Earth's history. Then when we are all in agreement we can remind them that such non-human emissions are very strong candidates for a variety of extinction events and large climate swings
We know perfectly well that non-human greenhouse gas and other emissions have had dramatic effects on the Earth's climate. We know perfectly well that such events have had terrible economic consquences at times. Only a fool or a Republican--but I repeat myself--would deny these facts, and if we practice a little argumentative judo we can perhaps move past these red herrings and get to the meat of the debate, which is what we should do in the next few years and decades to respond to the current situation.
First off, dark matter, even if it ultimately turns out to be wrong, is not a stupid idea;
I agree--dark matter is not even an idea. It is a family of ideas. They are all reasonable ideas. But having watched the growth of dark matter theories in the past twenty years--hot dark matter, cold dark matter, warm dark matter, MACHOs, WIMPs, etc ad nauseum--I think there is some justification for a degree of skepticism regarding any dark matter theory.
All I ask of proponents of any dark matter theory is that they specify:
1) Type: baronic or not? 2) Interaction: parameter space dimensions and constraints (that is, is it weak, gravitational only, exotic, and if so what are the model parameters and how are they constrained)? 3) Scale: stellar, galactic, local group, large scale galaxy distribution or CMB?
When people talk about dark matter as if it was a single theory rather than a family of hypotheses, like this guy does in the article:
"The dark matter model is not perfect, but it made a very specific prediction for the microwave background that seems to be coming true, and it fits galaxies and clusters and large-scale structure and gravitational lensing"
it is reasonable to point out that this is marketing, not science, and that there is nothing like a consensus with regard to the answers to my questions above. This does not mean that dark matter is a stupid idea. It means that a family of theories with a very large number of free parameters does not make a very satisfying explanation for anything.
However, we're still left with the age old question: If gravity is manifest as a particle, why can't we shield against it?
Because gravitons are spin 2. There's no nice "intuitive" way of explaining it, but within the mathematical framework of modern quantum field theory spin 2 particles always produce an attractive force between things that those particles interact with. This means that there is no possibility of "anti-gravity", which is what is required to shield against gravity. Electromagentic shielding is possible because photons, being spin 1, can produce either attractive or repulsive forces. This is how it comes to be that there are two electrical charges of opposite sign, whose differential displacements in matter allow us to create electromagentic sheilding. The spin-2 nature of gravitons means there is only one "gravitational" charge, called "mass".
The most one would be able to do with gravity is cancel out gravity waves in a small region by generating out-of-phase waves. The static field cannot be cancelled in this manner, so there is no way of shielding it.
All of this, of course, depends on the imperfect mathematics of quantum field theory, which may or may not be an accurate description of the universe.
If a researcher manipulates only part of an image then the researcher is implicitly admitting that there was something in the image that they chose to ignore. On the other hand, if a researcher changes the contrast of the whole image to make it easier to see the patterns they are drawing their conclusions from, then they can always claim they really didn't notice the other stuff. Essentially, researchers have to avoid doing things that prove that they were deliberately dishonest.
Having worked in a field where adaptive algorithms, particularly adaptive contrast enhancement, was absolutely necessary to get value from images, this seems to me to be an overly restrictive approach.
Adapative algorithms are valuable whenever images contain more low-frequency power than high-frequency signal ("frequency" == spatial frequency). For images with severe shading, which is common in certain types of radiotherapy imaging due to the underlying physics of radiation transport, adaptive constrast enhancment can make the difference between a useful image and a useless one.
So a blanket ban on adaptive algorithms is a solution that only applies to some fields. A more sensible policy would be to require authors to submit archival copies of the original images along with detailed instructions as to how they were manipulated for publication. That would ensure transparancy without actually requiring anyone to do any checking--the archives would build up over time until some bored post-doc got the idea to study them, resulting in a publication showing that half of all scientists are dishonest or incompetent (never discount incompetence--I once worked with a guy who published a paper where figure 2 was identical to figure 3 through a simple mistake that got past him, his co-authors, the editors and the reviewers.)
It is also worth noting that printing itself can be considered a form of gamma-correction, which may affect different parts of the image differently.
Several others have already pointed out that roughly 90% of lung cancers are known to be caused by smoking. It is true that 10% are not, just as 50% car accidents are not caused by drunk driving. But that doesn't make drunk driving ok, sensible or sane.
Back in the day when I worked in radiotherapy physics I came to a simple conclusion: if you took all the money being spent on the kind of research I was doing and put it into an modestly effective anti-smoking campaign, you would extend more lives much longer. This was based on the rates of lung and other cancers that were known at the time to be caused by smoking.
For greater context: a single treatment that eliminated 90% of cases of a major cancer with negligable side-effects would be considered a medical break-through of staggering proportions. Most headline-making genetic causes affect a few percent of a specific type of cancer. Even the major tumour-suppressor genes found so far only get into the 10-50% range.
Nothing in the current pipeline of medical miracles comes close to the effect of stopping smoking on lung cancer. And that's ignoring all the other health effects of smoking, from pulmonary emphasema to oral and other cancers.
Smokers do not "deserve" to get cancer. But they are addicted to a substance that is known to cause cancer, and which will almost certainly damage their health and shorten their lives. If it were possible to elimiate that substance it would be equivalent to a huge medical breakthrough. It is not possible to eliminate tabbacco, but it is certainly possible to call it what it is: a deadly, addictive drug being sold to often-willing victims by evil people.
Semantics are actions. "Associations between symbols" is mathematics, and pure mathematics at that: a closed universe of symbols that can be manipulated according to rules. Semantics, on the other hand, is what the symbols impel us to do. Speech is, of course, action, so semantics can impel us to argue, as well as running away, juggling, seducing (well, not anyone on/.) or whatever.
What something means is what we do, how we act, when we grasp the meaning.
This is not an argument against AI. In fact, it is an argument for it: when we give our machines a range of behaviour that extends beyond pure symbol manipulation (robots) we open the door to true intelligence that is indistinguishable from carbon-based intelligence. AI work that deals purely with symbol manipulation is useful but focussing on only a tiny fraction of the problem: most of our intelligence, like most of our communication capacity, is non-verbal.
People always forget and try to deal with large companies as if they are individuals with morals, feeling and so on.
Actually, I used to frequently make this mistake with people, too.
Companies are just like the individuals who run them, and most individuals are exactly the kind of people you would expect, looking at the state of the world: petty, stupid, grasping, small-minded and nasty.
You can do anything for individuals: protect them from being laid off, defend them to the board of directors, defend their work to clients who complain that it is shoddy and late, and they will still turn on you at the first opportunity, showing an absolute lack of generousity or flexibility and trying to solve every problem with threats rather than discussion or reason.
There really isn't a whole lot you can't use some mathematical model to explain. So given your reasoning, there ought to be no patents.
An explanation or a description of a thing is not the thing. There is nothing that can't be explained or described in English, either, but that does not make books patentable. You are confusing the use of math as a language used to describe and invention with the treatment of the math as an invention.
Re:Doomsday can come only from governments
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Forecasting Doomsday
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· Score: 2, Interesting
Communism offered them shortened lives with no reason to want to live
Shortened compared to what? The average lifespan in China rocketed upward in China after 1949. That's why they have a population problem. What's funny is that now that communism has lifted the nation out of the medeval mess it was in, we can see that Marx's Iron Law of History had it backwards: communism doesn't come after capitalism, but rather the other way around (no surpise to anyone who has studied the evolution of agrarian societies into mercantile ones.)
With regard to the larger picture, it is simply wrong to suggest that only goverments can create disasters. I think the whole libertarian/socialist debate is metaphorically similar to black and white supremicists arguing. Neither side can see that its favoured race/institution is in fact not very much different in capability than the other. There may be historical differences in how and where each side has done its good and evil, but both are capable of either, and both have done a good deal of each.
The current concept of "copyright" dates to the printing press.
But the idea that copyright is a property right and that copyright violation is theft is relatively recent.
Economists talk about the positive and negative externalities of economic behaviour. An "externality" is a consequence of an action that is not borne by the person taking the action. Positive externalities are good things that acrue to others through my actions that I do not get paid for. Negative externalities are bad things that happen to others because of my actions that they do not get compensated for.
Property rights are a human invention to minimize negative externalities. If I own property I can prevent others from using it to dump their waste, or from farming it and leaving me with the cost of maintaining it, etc. My property right protects my exclusive use of my property from the negative externalities that others may put upon it. At the same time, they prevent me from putting negative externalities on others.
Copyright is a human invention to protect positive externalities. As someone else has pointed out in a quote from Einstein, if I give you a new idea, you have the idea and I still have it. I have created a benefit for you without significant cost to myself. Copyright is a way of trying to protect in law the benefit I have given you, so that I may capture that positive externality in the form of some kind of payment.
Copyright and property rights are therefore different in kind. Copyright is licenseable (and sub-licensable if the license is written that way) but should not be salable as property. The GPL, for example, treats copyright this way.
Every absurd move in "intellectual property" law in the past couple of decades is fundamentally linked to the notion of ideas of any kind as "property". Once you have granted that notion, any number of insane things follow, including the notion that facts can be property.
The fundamental intellectual fight is to get rid of the idea of "intellectual property", and to explain when it comes up why it is an absurd idea with no historical basis, and an abuse of the term "property" as a false metaphor for what should be a licensing/sub-licensing relationship dealing with a temporary monopoly right that is artificially created to reward the creators of certain types of work to the general benefit of society.
Dark matter is just the best model we have right now. It also amazes me how much Slashdot is against the dark matter model. Why is that?
Lack of faith.
Dark matter is an unproven hypothesis (actually, multiple unproven hypotheses) that can be fine-tuned to account for any particular set of observations. However, there is as yet (to my knowledge) no generally accepted, closed set of parameters for dark matter models that will consistently explain all observed phenomena.
The "Dark Matter Problem" is at least two different problems. Galactic dark matter is (probably) baryonic matter that may explain the rotation curves of spiral galaxies. It unfortunately makes things like star formation and/or galaxy formation difficult, IIRC. But there are also dark matter problems on larger scales, and on the largest scales the invocation of dark matter requires non-baryonic particles of unknown type with peculiar interaction properties. Despite more than a decade of searching by some very good physicists, there are as yet no more than a few candidate events in various detectors that might be dark matter signatures.
So even though the dark matter model may be the best thing we have, but it simply isn't very good. By the standards of ordinary science it just isn't good enough. Too many parameters, too much complexity, too much handwaving.
One of the things that distinguishes science from faith is that scientists don't claim to have all the answers. We are willing to say, "I dunno" when faced with the hard questions. The faithful lack the courage to do this. This is why at the end of the day science teaches us new things, while faith leaves us festering in the mud.
to it's just plain silly to claim that our energy problems can be solved with solar and wind energy. They simply take up an enormous amount of land when compared with how much power they actually produce.
Starting your argument with a complete non sequitur is never a good debating tactic. What does the amount of land taken up by solar or wind farms have to do with their ability to solve our energy problems? Does the U.S. have a shortage of waste land? Not the last time I looked. Is there anything inherently wrong with a power plant that occupies an area ten miles on a side and produces zero emissions as opposed to one that occupies an area of one mile on a side (typicaly coal/nuclear plant property boundaries) and produces oodles of emissions/waste?
Lower power density per unit area doesn't seem to me to be an interesting constraint. It's even less interesting for solar than for wind, because a lot of building surface area can also be used for solar, making it a very effective dual-use system.
The only real problem with both solar and wind is that energy storage technolgy (batteries and fuel cells and hydrogen etc) still has a long way to go before it is cost effective, reliable and easy to use when compared to gas, oil and coal.
Sure is, and we're building a big wind farm on Wolfe Island, which is barely a biscuit-toss from New York State. So if any women in Watertown or Rochester start giving birth to two-headed babies, or cows stop giving milk, y'all know who to blame. It's the witches... err... Canadians.
The locals on Wolfe Island are pretty keen on the wind farm. The people working to develop it have done a lot of work over the past five years to keep them in the loop. And besides, as well as being smarter and better looking than Americans, Canadians are also braver--we have to be, given what the weather is like up here.
When I tell a potential employer I know Galois theory, he stares at me for a few seconds, and then asks me "Do you know how to use Excel?". To which I reply that I prefer Mathemathica and rarely touch Microsoft products. Then the interview is over.
This is absolutely accurate. Most people working in technology are a) not very smart and b) have incredibly fragile egos. Not so different from most people in general, in fact. This makes life hard for anyone with actual skills.
I know not a few "data analysts" with Ph.D.s who use Excel, and get all touchy if you suggest there are more appropriate tools for the job. Octave/Matlab is considered "advanced" and no one touches Mathematica, still less things like Perl (which is surprisingly fast--I once used an R-K solver in Perl that ran almost as fast as my first naive C++ implementation.)
The fact is that math is way too powerful to make much of a living at. Most technology problems require a tiny amount of math and a lot of engineering. Most people are either too stupid to see the value of the math or are threatened by the power of something they don't understand, so they adopt various heuristics that lower their productivity, as we've seen discussed in the thread on construction workers.
Re:Dynamic Demand
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Smart Power
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· Score: 2, Interesting
I think this is a great idea, but wonder about some of the implementation details. In particular, this implicitly couples all the homes using the load-leveling technology. That creates the possibility for feedback.
A simple scenario goes like this: demand on a given sub-grid is high due to a particular industrial load, say. All the homes in the area dutifully stop running their fridges and moderate their air-conditioning (by far the two biggest cyclic loads). The industrial user goes off-line, and all the homes turn back up to full power at once, causing wires to vapourize, milk to curdle and frogs to rain from the sky. Or something like that.
I'm sure the real failure mode will be far more complex than this--the people doing this kind of thing will obviously think of all the obvious things that could happen. But even weakly coupled complex systems can exhibit remarkably complex behaviour, and I fully expect that if we go this route in a big way we will necessarily discover some of the less likely failure modes over the first few decades of use.
The bubbles are seriously far from thermodynamic equilibrium, so assigning a single "temperature" is misleading. If this is fusion there are clusters are particles with average energy quite a bit higher than that implied by 15,000 K.
To answer another question in this thread: the reason to be skeptical about this means of inducing hot fusion ever reaching breakeven is twofold. For one, there are getting on for a dozen different ways of inducing hot fusion that have failed to get close to breakeven in the past fifty years. Fusion is the technology of the future and always will be. For two, hot fusion in a small volume of high density matter is pretty much a worst-case in terms of loss processes.
However, given that no one would ever have predicted this phenomenon to occur at all, it is certainly not impossible that it will someday reach breakeven. My personal bias is that would be a very good thing, but I'm not hopeful that it will ever happen. Still, sometimes moonshine turns out to be stronger than anyone expected.
Cepheid variable stars are one of the most basic "standard candles" on which our measurement of interstellar distances depends. Polaris is one of the closest Cepheids.
Cepheid periods depend on luminosity, but the period-luminosity relation is still semi-empirical. Knowing the mass of Polaris (which you can get from measuring the orbital elements of the companion star) pins down one of the important variables in the theoretical model of Cepheids, and so helps firm up one of the basic measuring instruments we use to determine the scale of the universe.
In the past, there have been significant changes in our beliefs about the scale of the universe due to problems with interpretation of variable star data--the discovery that some presumed Cepheids were actually RR Lyrae variables changed things by about a factor of two, IIRC.
Things are a lot better than that now, but it is still good to see that people are working to ensure our view of the universe is as consistent and accurate as possible.
Brian Stableford used this idea in the novel Wildeblood's Empire in the '70's, which was part of the Daedalus series. These books are worth reading if you can find them--some of the best scientific puzzle stories ever produced, with extremely interesting speculations regarding alternative ecosystems.
Right now a patent is just another gun in the armory of larger corps. As a small time inventor you will probably not have the stamina and the funds it will take to defend your patent, and as a larger corp you can use the patent system to beat up competitors smaller than you.
This is absolutely accurate. A patent is nothing more than a license to sue, and if you don't have a phalanx of lawyers on staff to enforce them they are not particularly useful.
I've been involved in a number of small corporations and startups that have spent a significant fraction of their budgets pursuing patent protection, but they have in the end had to face the reality that while a patent costs ~$25,000 to get (no small expense for a startup) patent disputes typically cost in the range of $2-5 MILLION if they go to court.
Ergo, if Big Corp is violating Small Corp's patent, they can do so with impunity so long as Small Corp does not have a war chest of a few million waiting to be deployed to fight a court action.
Of the many proposals for patent reform, denying trivial patents and patents on copyrighted work are the most important, but putting in place a non-adversarial, low-cost dispute-resolution mechanism would also be extremely valuable. Such a system would not be perfectly just, which would be a big improvement over the current system, which is perfectly unjust.
I don't know anyone specializing in Aero so verifying your assertion regarding airplane wings would take more work than I'm willing to exert.
I'm a physicist with a undergraduate degree in mechanical/aeronautical engineering. Pre-war aeronautical engineering was very heavily empirical, although there was some use of exact solutions (the elipical wing of the Spitfire was the result of the mathematical simplicity of treating that particular shape, IIRC). Heavy investment in the physics of flight was a post-war phenomena.
He asked the questions no one else thought to ask, and produced the answers through nothing more than logical deduction.
These claims are both false and do a profound disservice to Einstein.
He asked the same questions as everyone else, but he sought answers in places no one else thought to look. In particular, with regard to special relativity, while everyone else was looking at dynamics and positing undetectable entities, he lifted the carpet of kinematics and found amongst the loose change lying there a diamond: clear and hard and perfect. Nor was this a random search on his part--it was precisely his genius that let him ignore the clutter and noise of the dynamical theorists and see the tiny lump that diamond made in the carpet while everyone else was standing on it and not noticing.
Nor did he use "nothing more than logical deduction". His work was profoundly creative. In the case of general relativity he realized that the solution to the problem of gravity was that of general invariance--the equations that describe the motion of objects should not change their algebraic form when the co-ordinate system they are described relative to undergoes any second-order smooth symmetrical transformation. But recognizing that this condition must be fulfilled--which is a again the insight of genius--is far from sufficient to determine what the form of the equations actually are. But Einstein was able, using a combination of creativity, imagination, guess-work and intuition, to find the general algebraic form that satisfied this constraint.
Einstein is second only to Newton in the history of physics because of a combination of good fortune, personality, character and intelligence. The good fortune comes in being born in the right place and time, when great problems were facing great minds, which provided a rich landscape for their deeds. Every hero needs a dragon to slay. Their personalities made them comfortable playing a large role in world events--Newton's arrogance and Einstein's humanity drove them to have an influence on the world when others might have been willing to retire into the shadows. They both were obsessive in character, which is pretty much required to be great. And they were both supremely intelligent, whatever that combination of discipline, logic, imagination, playfulness, ruthlessness and persistence actually means.
Will there ever be another Einstein? No. No more than there will be another Isaac Newton. There will be a completely new figure who will have such an incredible way of looking at the Universe that it will put everyone else to shame.
In this at least we are in full agreement, although I would say, "leave everyone else in awe." There is no shame in finding enlightenment in the genius of others.
two, concurrent and independent sonofusion breakthroughs
The big-news sonofusion results in 2005 were about neutron, not power, generation. There was some evidence that acoustically-driven cavitation could produce temperatures high enough to result in fusion-generated neutrons. This is quite exciting in terms of understanding the basic processes involved. However, in terms of the driving physics, this is hot fusion: a very small volume of material may be heated to extremely high temperatures for a very short time, resulting in a tiny amount of fusion occuring.
Due to fundamental physical constraints it is very unlikely that such a process is scalable in a way that will produce more power than is required to generate it. The bottom line for hot fusion is that the cross-sections for loss processes are orders of magnitude larger than those for the fusion process itself, and the losses scale as the surface area of the hot volume while power production scales with the volume. This means that the cube-square law strongly favours really big hot-fusion reactors (something the size of a star seems about optimal).
So while it is not impossible that one day we'll all drive cars powered by sonofusion, I don't think anyone working in the field is suggesting that.
Slashdot Mirror
From the article:
"The shuttle did not explode in the common definition of that word... Challenger itself was torn apart as it was flung free of the other rocket components and turned broadside into the Mach 2 airstream. Individual propellant tanks were seen exploding -- but by then, the spacecraft was already in pieces."
Explosion...(2)... "a large-scale, rapid, or spectacular expansion or bursting out or forth" (www.m-w.com)
Coming to peices in a matter of a second or so, after being mysteriously "flung free" of the other rocket components, would ordinarily be called an explosion. Otherwise, we would be left wondering how something really large could come to pieces in a second without exploding, in the ordinary phenomenological sense of the term.
The guy who wrote the article doesn't even follow his own pedantic rules when he describes the orbiter being "flung free". If we are to be pedantic literalists we must acknowledge that it wasn't "flung free", which implies an impulsive force between the external tank, the SRBs and the orbiter. Rather, structural integrity between the various components was lost due to purely areodynamic forces, as the article itself relates.
So let me be the first to debunk the eighth myth regarding what will heretofore be known as "the Challenger aerodynamically-driven rapid disassembly": despite popular belief to the contraray, the orbiter was not "flung free" from the other rocket components, but rather merely followed an independent trajectory governed by purely areodynamic forces.
I have an epistemological question for everyone who supports any form of wiretapping without a warrant: How do you know that the wiretapping is being done for purposes of "anti-terrorism" or to "people the government is suspicious of"?
The purpose of requiring a warrant is that a warrant can only be issued by a court, and the purpose of the court is to examine the truth, or at least the plausibility, of the claims being made to justify the need for a warrant. Without a warrant, without a court, the only answer to my question is, "We know because George Bush or one of his designates says so."
Given the record of the Bush administration on matters of truth, such as the claims regarding WMDs in Iraq and Iraq's support of al Qaeda, it seems to me a bad idea to make the administration's say-so a major plank in your epistemological platform. This is just common sense. No one would recommend trusting one's money blindly to a financial advisor who had lost everything in a major blunder that later turned out to be based on transparently false claims.
What's more, volcanos are one of the processes that set the natural equilibrium, while human emissions are a new component.
What makes volcanic emissions, which intermitently create global catastrophy, part of the "natural equilibrium"? What on Earth is the "natural equilibrium" anyway?
Of all the stupid red herrings in the global warming debate, the idea that there is any distinction between human and non-human sources of greenhouse gasses is the reddest. Terrestrial homeostatis does not care where the gasses are coming from. It only cares how much and on what timescale, and when it happens relative to various other semi-periodic phenomena. The claim that the current human emissions of greenhouses gasses are somehow out of range compared to past non-human greenhouse events is nothing but a transparent attempt to introduce an element of hysteria into a debate that already has far too much of it on both sides.
This claim about human emissions being somehow different from non-human ones seems to me to be an attempt to pre-empt all of the wacko arguments from the other side that deal with non-human greenhouse emmissions. I think a far better approach is to acknowledge all of those sources as important, and agree firmly with our opponents that such sources have been very important in the Earth's history. Then when we are all in agreement we can remind them that such non-human emissions are very strong candidates for a variety of extinction events and large climate swings
We know perfectly well that non-human greenhouse gas and other emissions have had dramatic effects on the Earth's climate. We know perfectly well that such events have had terrible economic consquences at times. Only a fool or a Republican--but I repeat myself--would deny these facts, and if we practice a little argumentative judo we can perhaps move past these red herrings and get to the meat of the debate, which is what we should do in the next few years and decades to respond to the current situation.
First off, dark matter, even if it ultimately turns out to be wrong, is not a stupid idea;
I agree--dark matter is not even an idea. It is a family of ideas. They are all reasonable ideas. But having watched the growth of dark matter theories in the past twenty years--hot dark matter, cold dark matter, warm dark matter, MACHOs, WIMPs, etc ad nauseum--I think there is some justification for a degree of skepticism regarding any dark matter theory.
All I ask of proponents of any dark matter theory is that they specify:
1) Type: baronic or not?
2) Interaction: parameter space dimensions and constraints (that is, is it weak, gravitational only, exotic, and if so what are the model parameters and how are they constrained)?
3) Scale: stellar, galactic, local group, large scale galaxy distribution or CMB?
When people talk about dark matter as if it was a single theory rather than a family of hypotheses, like this guy does in the article:
"The dark matter model is not perfect, but it made a very specific prediction for the microwave background that seems to be coming true, and it fits galaxies and clusters and large-scale structure and gravitational lensing"
it is reasonable to point out that this is marketing, not science, and that there is nothing like a consensus with regard to the answers to my questions above. This does not mean that dark matter is a stupid idea. It means that a family of theories with a very large number of free parameters does not make a very satisfying explanation for anything.
I guess they figured "everything-but-axial-vector gravity" would sound awkward.
However, we're still left with the age old question: If gravity is manifest as a particle, why can't we shield against it?
Because gravitons are spin 2. There's no nice "intuitive" way of explaining it, but within the mathematical framework of modern quantum field theory spin 2 particles always produce an attractive force between things that those particles interact with. This means that there is no possibility of "anti-gravity", which is what is required to shield against gravity. Electromagentic shielding is possible because photons, being spin 1, can produce either attractive or repulsive forces. This is how it comes to be that there are two electrical charges of opposite sign, whose differential displacements in matter allow us to create electromagentic sheilding. The spin-2 nature of gravitons means there is only one "gravitational" charge, called "mass".
The most one would be able to do with gravity is cancel out gravity waves in a small region by generating out-of-phase waves. The static field cannot be cancelled in this manner, so there is no way of shielding it.
All of this, of course, depends on the imperfect mathematics of quantum field theory, which may or may not be an accurate description of the universe.
If a researcher manipulates only part of an image then the researcher is implicitly admitting that there was something in the image that they chose to ignore. On the other hand, if a researcher changes the contrast of the whole image to make it easier to see the patterns they are drawing their conclusions from, then they can always claim they really didn't notice the other stuff. Essentially, researchers have to avoid doing things that prove that they were deliberately dishonest.
Having worked in a field where adaptive algorithms, particularly adaptive contrast enhancement, was absolutely necessary to get value from images, this seems to me to be an overly restrictive approach.
Adapative algorithms are valuable whenever images contain more low-frequency power than high-frequency signal ("frequency" == spatial frequency). For images with severe shading, which is common in certain types of radiotherapy imaging due to the underlying physics of radiation transport, adaptive constrast enhancment can make the difference between a useful image and a useless one.
So a blanket ban on adaptive algorithms is a solution that only applies to some fields. A more sensible policy would be to require authors to submit archival copies of the original images along with detailed instructions as to how they were manipulated for publication. That would ensure transparancy without actually requiring anyone to do any checking--the archives would build up over time until some bored post-doc got the idea to study them, resulting in a publication showing that half of all scientists are dishonest or incompetent (never discount incompetence--I once worked with a guy who published a paper where figure 2 was identical to figure 3 through a simple mistake that got past him, his co-authors, the editors and the reviewers.)
It is also worth noting that printing itself can be considered a form of gamma-correction, which may affect different parts of the image differently.
Several others have already pointed out that roughly 90% of lung cancers are known to be caused by smoking. It is true that 10% are not, just as 50% car accidents are not caused by drunk driving. But that doesn't make drunk driving ok, sensible or sane.
Back in the day when I worked in radiotherapy physics I came to a simple conclusion: if you took all the money being spent on the kind of research I was doing and put it into an modestly effective anti-smoking campaign, you would extend more lives much longer. This was based on the rates of lung and other cancers that were known at the time to be caused by smoking.
For greater context: a single treatment that eliminated 90% of cases of a major cancer with negligable side-effects would be considered a medical break-through of staggering proportions. Most headline-making genetic causes affect a few percent of a specific type of cancer. Even the major tumour-suppressor genes found so far only get into the 10-50% range.
Nothing in the current pipeline of medical miracles comes close to the effect of stopping smoking on lung cancer. And that's ignoring all the other health effects of smoking, from pulmonary emphasema to oral and other cancers.
Smokers do not "deserve" to get cancer. But they are addicted to a substance that is known to cause cancer, and which will almost certainly damage their health and shorten their lives. If it were possible to elimiate that substance it would be equivalent to a huge medical breakthrough. It is not possible to eliminate tabbacco, but it is certainly possible to call it what it is: a deadly, addictive drug being sold to often-willing victims by evil people.
Semantics are associations between symbols.
/.) or whatever.
Semantics are actions. "Associations between symbols" is mathematics, and pure mathematics at that: a closed universe of symbols that can be manipulated according to rules. Semantics, on the other hand, is what the symbols impel us to do. Speech is, of course, action, so semantics can impel us to argue, as well as running away, juggling, seducing (well, not anyone on
What something means is what we do, how we act, when we grasp the meaning.
This is not an argument against AI. In fact, it is an argument for it: when we give our machines a range of behaviour that extends beyond pure symbol manipulation (robots) we open the door to true intelligence that is indistinguishable from carbon-based intelligence. AI work that deals purely with symbol manipulation is useful but focussing on only a tiny fraction of the problem: most of our intelligence, like most of our communication capacity, is non-verbal.
People always forget and try to deal with large companies as if they are individuals with morals, feeling and so on.
Actually, I used to frequently make this mistake with people, too.
Companies are just like the individuals who run them, and most individuals are exactly the kind of people you would expect, looking at the state of the world: petty, stupid, grasping, small-minded and nasty.
You can do anything for individuals: protect them from being laid off, defend them to the board of directors, defend their work to clients who complain that it is shoddy and late, and they will still turn on you at the first opportunity, showing an absolute lack of generousity or flexibility and trying to solve every problem with threats rather than discussion or reason.
There really isn't a whole lot you can't use some mathematical model to explain. So given your reasoning, there ought to be no patents.
An explanation or a description of a thing is not the thing. There is nothing that can't be explained or described in English, either, but that does not make books patentable. You are confusing the use of math as a language used to describe and invention with the treatment of the math as an invention.
Communism offered them shortened lives with no reason to want to live
Shortened compared to what? The average lifespan in China rocketed upward in China after 1949. That's why they have a population problem. What's funny is that now that communism has lifted the nation out of the medeval mess it was in, we can see that Marx's Iron Law of History had it backwards: communism doesn't come after capitalism, but rather the other way around (no surpise to anyone who has studied the evolution of agrarian societies into mercantile ones.)
With regard to the larger picture, it is simply wrong to suggest that only goverments can create disasters. I think the whole libertarian/socialist debate is metaphorically similar to black and white supremicists arguing. Neither side can see that its favoured race/institution is in fact not very much different in capability than the other. There may be historical differences in how and where each side has done its good and evil, but both are capable of either, and both have done a good deal of each.
In fact, I believe war requires democracy.
Ah, I see. I hadn't realized you were insane.
The current concept of "copyright" dates to the printing press.
But the idea that copyright is a property right and that copyright violation is theft is relatively recent.
Economists talk about the positive and negative externalities of economic behaviour. An "externality" is a consequence of an action that is not borne by the person taking the action. Positive externalities are good things that acrue to others through my actions that I do not get paid for. Negative externalities are bad things that happen to others because of my actions that they do not get compensated for.
Property rights are a human invention to minimize negative externalities. If I own property I can prevent others from using it to dump their waste, or from farming it and leaving me with the cost of maintaining it, etc. My property right protects my exclusive use of my property from the negative externalities that others may put upon it. At the same time, they prevent me from putting negative externalities on others.
Copyright is a human invention to protect positive externalities. As someone else has pointed out in a quote from Einstein, if I give you a new idea, you have the idea and I still have it. I have created a benefit for you without significant cost to myself. Copyright is a way of trying to protect in law the benefit I have given you, so that I may capture that positive externality in the form of some kind of payment.
Copyright and property rights are therefore different in kind. Copyright is licenseable (and sub-licensable if the license is written that way) but should not be salable as property. The GPL, for example, treats copyright this way.
Every absurd move in "intellectual property" law in the past couple of decades is fundamentally linked to the notion of ideas of any kind as "property". Once you have granted that notion, any number of insane things follow, including the notion that facts can be property.
The fundamental intellectual fight is to get rid of the idea of "intellectual property", and to explain when it comes up why it is an absurd idea with no historical basis, and an abuse of the term "property" as a false metaphor for what should be a licensing/sub-licensing relationship dealing with a temporary monopoly right that is artificially created to reward the creators of certain types of work to the general benefit of society.
Dark matter is just the best model we have right now. It also amazes me how much Slashdot is against the dark matter model. Why is that?
Lack of faith.
Dark matter is an unproven hypothesis (actually, multiple unproven hypotheses) that can be fine-tuned to account for any particular set of observations. However, there is as yet (to my knowledge) no generally accepted, closed set of parameters for dark matter models that will consistently explain all observed phenomena.
The "Dark Matter Problem" is at least two different problems. Galactic dark matter is (probably) baryonic matter that may explain the rotation curves of spiral galaxies. It unfortunately makes things like star formation and/or galaxy formation difficult, IIRC. But there are also dark matter problems on larger scales, and on the largest scales the invocation of dark matter requires non-baryonic particles of unknown type with peculiar interaction properties. Despite more than a decade of searching by some very good physicists, there are as yet no more than a few candidate events in various detectors that might be dark matter signatures.
So even though the dark matter model may be the best thing we have, but it simply isn't very good. By the standards of ordinary science it just isn't good enough. Too many parameters, too much complexity, too much handwaving.
One of the things that distinguishes science from faith is that scientists don't claim to have all the answers. We are willing to say, "I dunno" when faced with the hard questions. The faithful lack the courage to do this. This is why at the end of the day science teaches us new things, while faith leaves us festering in the mud.
to it's just plain silly to claim that our energy problems can be solved with solar and wind energy. They simply take up an enormous amount of land when compared with how much power they actually produce.
Starting your argument with a complete non sequitur is never a good debating tactic. What does the amount of land taken up by solar or wind farms have to do with their ability to solve our energy problems? Does the U.S. have a shortage of waste land? Not the last time I looked. Is there anything inherently wrong with a power plant that occupies an area ten miles on a side and produces zero emissions as opposed to one that occupies an area of one mile on a side (typicaly coal/nuclear plant property boundaries) and produces oodles of emissions/waste?
Lower power density per unit area doesn't seem to me to be an interesting constraint. It's even less interesting for solar than for wind, because a lot of building surface area can also be used for solar, making it a very effective dual-use system.
The only real problem with both solar and wind is that energy storage technolgy (batteries and fuel cells and hydrogen etc) still has a long way to go before it is cost effective, reliable and easy to use when compared to gas, oil and coal.
So, uh, any space up in Canada?
Sure is, and we're building a big wind farm on Wolfe Island, which is barely a biscuit-toss from New York State. So if any women in Watertown or Rochester start giving birth to two-headed babies, or cows stop giving milk, y'all know who to blame. It's the witches... err... Canadians.
The locals on Wolfe Island are pretty keen on the wind farm. The people working to develop it have done a lot of work over the past five years to keep them in the loop. And besides, as well as being smarter and better looking than Americans, Canadians are also braver--we have to be, given what the weather is like up here.
When I tell a potential employer I know Galois theory, he stares at me for a few seconds, and then asks me "Do you know how to use Excel?". To which I reply that I prefer Mathemathica and rarely touch Microsoft products. Then the interview is over.
This is absolutely accurate. Most people working in technology are a) not very smart and b) have incredibly fragile egos. Not so different from most people in general, in fact. This makes life hard for anyone with actual skills.
I know not a few "data analysts" with Ph.D.s who use Excel, and get all touchy if you suggest there are more appropriate tools for the job. Octave/Matlab is considered "advanced" and no one touches Mathematica, still less things like Perl (which is surprisingly fast--I once used an R-K solver in Perl that ran almost as fast as my first naive C++ implementation.)
The fact is that math is way too powerful to make much of a living at. Most technology problems require a tiny amount of math and a lot of engineering. Most people are either too stupid to see the value of the math or are threatened by the power of something they don't understand, so they adopt various heuristics that lower their productivity, as we've seen discussed in the thread on construction workers.
I think this is a great idea, but wonder about some of the implementation details. In particular, this implicitly couples all the homes using the load-leveling technology. That creates the possibility for feedback.
A simple scenario goes like this: demand on a given sub-grid is high due to a particular industrial load, say. All the homes in the area dutifully stop running their fridges and moderate their air-conditioning (by far the two biggest cyclic loads). The industrial user goes off-line, and all the homes turn back up to full power at once, causing wires to vapourize, milk to curdle and frogs to rain from the sky. Or something like that.
I'm sure the real failure mode will be far more complex than this--the people doing this kind of thing will obviously think of all the obvious things that could happen. But even weakly coupled complex systems can exhibit remarkably complex behaviour, and I fully expect that if we go this route in a big way we will necessarily discover some of the less likely failure modes over the first few decades of use.
The bubbles are seriously far from thermodynamic equilibrium, so assigning a single "temperature" is misleading. If this is fusion there are clusters are particles with average energy quite a bit higher than that implied by 15,000 K.
To answer another question in this thread: the reason to be skeptical about this means of inducing hot fusion ever reaching breakeven is twofold. For one, there are getting on for a dozen different ways of inducing hot fusion that have failed to get close to breakeven in the past fifty years. Fusion is the technology of the future and always will be. For two, hot fusion in a small volume of high density matter is pretty much a worst-case in terms of loss processes.
However, given that no one would ever have predicted this phenomenon to occur at all, it is certainly not impossible that it will someday reach breakeven. My personal bias is that would be a very good thing, but I'm not hopeful that it will ever happen. Still, sometimes moonshine turns out to be stronger than anyone expected.
Cepheid variable stars are one of the most basic "standard candles" on which our measurement of interstellar distances depends. Polaris is one of the closest Cepheids.
Cepheid periods depend on luminosity, but the period-luminosity relation is still semi-empirical. Knowing the mass of Polaris (which you can get from measuring the orbital elements of the companion star) pins down one of the important variables in the theoretical model of Cepheids, and so helps firm up one of the basic measuring instruments we use to determine the scale of the universe.
In the past, there have been significant changes in our beliefs about the scale of the universe due to problems with interpretation of variable star data--the discovery that some presumed Cepheids were actually RR Lyrae variables changed things by about a factor of two, IIRC.
Things are a lot better than that now, but it is still good to see that people are working to ensure our view of the universe is as consistent and accurate as possible.
Brian Stableford used this idea in the novel Wildeblood's Empire in the '70's, which was part of the Daedalus series. These books are worth reading if you can find them--some of the best scientific puzzle stories ever produced, with extremely interesting speculations regarding alternative ecosystems.
Right now a patent is just another gun in the armory of larger corps. As a small time inventor you will probably not have the stamina and the funds it will take to defend your patent, and as a larger corp you can use the patent system to beat up competitors smaller than you.
This is absolutely accurate. A patent is nothing more than a license to sue, and if you don't have a phalanx of lawyers on staff to enforce them they are not particularly useful.
I've been involved in a number of small corporations and startups that have spent a significant fraction of their budgets pursuing patent protection, but they have in the end had to face the reality that while a patent costs ~$25,000 to get (no small expense for a startup) patent disputes typically cost in the range of $2-5 MILLION if they go to court.
Ergo, if Big Corp is violating Small Corp's patent, they can do so with impunity so long as Small Corp does not have a war chest of a few million waiting to be deployed to fight a court action.
Of the many proposals for patent reform, denying trivial patents and patents on copyrighted work are the most important, but putting in place a non-adversarial, low-cost dispute-resolution mechanism would also be extremely valuable. Such a system would not be perfectly just, which would be a big improvement over the current system, which is perfectly unjust.
I don't know anyone specializing in Aero so verifying your assertion regarding airplane wings would take more work than I'm willing to exert.
I'm a physicist with a undergraduate degree in mechanical/aeronautical engineering. Pre-war aeronautical engineering was very heavily empirical, although there was some use of exact solutions (the elipical wing of the Spitfire was the result of the mathematical simplicity of treating that particular shape, IIRC). Heavy investment in the physics of flight was a post-war phenomena.
He asked the questions no one else thought to ask, and produced the answers through nothing more than logical deduction.
These claims are both false and do a profound disservice to Einstein.
He asked the same questions as everyone else, but he sought answers in places no one else thought to look. In particular, with regard to special relativity, while everyone else was looking at dynamics and positing undetectable entities, he lifted the carpet of kinematics and found amongst the loose change lying there a diamond: clear and hard and perfect. Nor was this a random search on his part--it was precisely his genius that let him ignore the clutter and noise of the dynamical theorists and see the tiny lump that diamond made in the carpet while everyone else was standing on it and not noticing.
Nor did he use "nothing more than logical deduction". His work was profoundly creative. In the case of general relativity he realized that the solution to the problem of gravity was that of general invariance--the equations that describe the motion of objects should not change their algebraic form when the co-ordinate system they are described relative to undergoes any second-order smooth symmetrical transformation. But recognizing that this condition must be fulfilled--which is a again the insight of genius--is far from sufficient to determine what the form of the equations actually are. But Einstein was able, using a combination of creativity, imagination, guess-work and intuition, to find the general algebraic form that satisfied this constraint.
Einstein is second only to Newton in the history of physics because of a combination of good fortune, personality, character and intelligence. The good fortune comes in being born in the right place and time, when great problems were facing great minds, which provided a rich landscape for their deeds. Every hero needs a dragon to slay. Their personalities made them comfortable playing a large role in world events--Newton's arrogance and Einstein's humanity drove them to have an influence on the world when others might have been willing to retire into the shadows. They both were obsessive in character, which is pretty much required to be great. And they were both supremely intelligent, whatever that combination of discipline, logic, imagination, playfulness, ruthlessness and persistence actually means.
Will there ever be another Einstein? No. No more than there will be another Isaac Newton. There will be a completely new figure who will have such an incredible way of looking at the Universe that it will put everyone else to shame.
In this at least we are in full agreement, although I would say, "leave everyone else in awe." There is no shame in finding enlightenment in the genius of others.
two, concurrent and independent sonofusion breakthroughs
The big-news sonofusion results in 2005 were about neutron, not power, generation. There was some evidence that acoustically-driven cavitation could produce temperatures high enough to result in fusion-generated neutrons. This is quite exciting in terms of understanding the basic processes involved. However, in terms of the driving physics, this is hot fusion: a very small volume of material may be heated to extremely high temperatures for a very short time, resulting in a tiny amount of fusion occuring.
Due to fundamental physical constraints it is very unlikely that such a process is scalable in a way that will produce more power than is required to generate it. The bottom line for hot fusion is that the cross-sections for loss processes are orders of magnitude larger than those for the fusion process itself, and the losses scale as the surface area of the hot volume while power production scales with the volume. This means that the cube-square law strongly favours really big hot-fusion reactors (something the size of a star seems about optimal).
So while it is not impossible that one day we'll all drive cars powered by sonofusion, I don't think anyone working in the field is suggesting that.