Summary: "If JVMs were smart, garbage collection would be fast."
Reality: "JVMs are mostly very stupid, and you can never be sure what JVM your users are going to use, so in the real world of deployed applications garbage collection performance--and Java performance generally--is a nightmare."
I am so tired of GC advocates talking smugly about theoretical scenarios. Who cares?. When I can run a Java app on an arbitrary JVM and not have it come to a grinding halt every once in a while as the garbage collector runs--or worse yet bring the machine to a grinding halt because the garbage collector never runs--only then will GC will be useful.
The weasel-words in the article are worthy of a PHB: "the garbage collection approach tends to deal with memory management in large batches" Translation: "I wish GC dealt with memory management in large chunks, but it doesn't, so I can't in all honesty say it does, but I can imagine a theoretical scenario where it does, so I'll talk about that theoretical scenario that I wish was real instead of what is actually real."
This is not to say that there aren't one or two decent JVMs out there that have decent GC performance. But having managed a large team that deployed a very powerful Java data analysis and visualization application, and having done work in the code myself, and having had to deal with user's real-world performance issues and having seen the incredible hoops my team had to go through to get decent performance, I can honestly say that up until last year, at least, Java was Not There with regard to GC and performance.
The most telling proof: my team did such a good job and our app was so fast that many users didn't believe it was written in Java. It was users making that judgement, not developers. Users whose only exposure to Java was as users, and whose empirical observation of the language was that it resulted in extremely slow apps. They didn't observe that it was theoretically possible to write slow apps. They observed that it was really, really easy to write slow apps, in the same way it's really easy to write apps that fall over in C++, despite the fact that theoretically you can write C++ apps that never leak or crash due to developers screwing up memory.
Every language has its strengths. Java is a good, robust language that is safe to put into the hands of junior developers to do things that would take a senior developer to do in C++. But its poor performance isn't a myth, nor is its tendency to hog system resources due to poor GC. Those are emprical facts, and this article introduces no actual data to demonstrate otherwise.
As I've pointed out before on/., Oliver Heaviside was the first person to write down E = mc^2, in 1892 or thereabouts. He did so based on an electro-mechanical model of the electron, where the mass of the electron was due to the resistance of the electric field to motion as the electron travelled through the aether. The same approach is what let Lorentz and Poincare' write down the full expression of what would eventually be known as Special Relativity several years before Einstein.
Einstein's contribution was to show that what these others derived from a dynamical theory could be understood in kinematic terms. Dynamics is the study of the causes of motion, and kinematics is the description of motion. In the pre-Einstein theory the resistance of the electron to motion--and the contraction of moving electrons in the direction of motion--was understood as due to electro-magnetic forces acting on it due to the aether. What Einstein showed was that the same phenomena could be understood in purely kinematic terms, as a consequence of the way motion must be described if the laws of physics are to be the same for all observers.
To get a sense of how profound this is, imagine that at one time the inverse-square law for light had been understood in terms of an absorbing medium. That is, the fact that lights appeared dimmer as the square of the distance to the observer was explained by empty space being filled with a substance that absorbed light. There would be many difficulties with such a theory, but I'm sure with sufficient mathematical prowess one could make it work. Then someone like Einstein comes along and points out that one can explain the phenomenon in purely geometric terms, as a consequence of the way the light is spreading out over the surface of a larger sphere as it gets further from the source. What previously required a complex, difficult mathematical description now becomes so trivial that even a philosopher can understand it.
That was Einstein's contribution, but it shouldn't completely eclipse the work of those who came before.
The UN would "force" them the same way they forced Saddam to disarm. Many years of weakly worded resolutions and loud bellyaching.
Your post implies that Saddam was armed, and armed with WMDs, as those were the primary target of UN resolutions.
That is false. Iraq had no WMDs, nor any plans to build them, nor any facilities capable of building them.
So it would appear that all those weakly worded resolutions might have had an affect after all, although in many respects the whole sanctions regime, oil-for-food, etc., was a disaster.
i found out that happiness is just a balance of the right drugs.
And satiation is "just" a matter of good food in appropriate amounts.
This, and a number of other posts, suggest that the experience of happiness is not "real" somehow, because it is subjective, or subject to chemical intervention, or something.
But we are real. What we experience is real. What we experience is causally connected to the material world that we are inseparably part of. This does not make the experience unreal. It means that happiness, like life, is a property of matter.
No one says, "I used to think that birds could fly, but then I found out it was just their wing structure." Flight is a capacity of matter, no less than happiness. Put matter in the right configuration (a seagull, say) and it'll take off every time. This does not make flight unreal.
So why does anyone think that happiness is any less real than mass or pH?
Other parts of the Bible say what can and can not be done with women taken in war, and forcing them to have sex with you was forbidden.
False. Forcing them to have sex with you was explicitly permitted, and there were rules governing it:
Deuteronomy 21:11-14 When thou goest forth to war against thine enemies, and the LORD thy God hath delivered them into thine hands, and thou hast taken them captive, And seest among the captives a beautiful woman, and hast a desire unto her, that thou wouldest have her to thy wife; Then thou shalt bring her home to thine house, and she shall shave her head, and pare her nails; And she shall put the raiment of her captivity from off her, and shall remain in thine house, and bewail her father and her mother a full month: and after that thou shalt go in unto her, and be her husband, and she shall be thy wife. And it shall be, if thou have no delight in her, then thou shalt let her go whither she will; but thou shalt not sell her at all for money, thou shalt not make merchandise of her, because thou hast humbled her.
You will note that there is no mention anywhere of the woman's consent. Ergo, this is nothing but a permit to rape, so long as you let your rape victim mourn her dead family for a month. And if you didn't enjoy raping her it says you can kick her out of your house, but not sell her into slavery.
Look at it from her point of view: you've over-run her city, killed her family, taken her captive, left her alone for a month and then forced her to have sex with you. Forcing someone to have sex without their consent is rape. Rape by elaborate rules is still rape, and the Bible clearly and unequivocally condones it.
Timecards reflect essential truth, if not literal truth of when work is done.
Timecards measure inputs, not outputs. Measuring inputs and assuming they serve as adequate surrogates for outputs is bad engineering and bad management.
Case in point: at Three Mile Island the control room systems reported that a given valve was closed when in fact it was locked solidly open. The problem was that the system was designed to measure current running to the motor that controlled the valve, which has an extremely weak relationship to the movement of the valve. Both mechanical and electrical failures could decouple the input and the output, and did.
So one of the most important things about dealing with suits is to make sure you measure outputs, and make sure the suits know that your team has good outputs for the inputs (ie. high productivity.)
If you're challenged on your team not having low enough productivity (ie. not working long enough hours) it is important to have the latest output measures at hand, and to point out that maximum productivity is achieved at around 35 hours per week. It is also important to be able to cite the extensive studies across many industries that back up that uncontroversial fact. If anyone ever talks in a meeting about the number of hours they work, or their team works, as if that was a good thing, cut them off immediately with "On my team we focus on outputs, not inputs..." NEVER let anyone get away with pretending that long hours are anything other than low productivity.
I am an extremely quantitative manager, and the people who have worked for me love it, and the people who I have worked for hate it. It shorts out all their monkey heirarchy circuits by actually focussing on what the business is supposed to be doing (being productive) rather than on what it is actually doing (stroking the monkey egos of managers and execs.)
Lest anyone think this is an anti-business rant, I should point out that I think these problems are universal human problems. They can be found in political parties, labour unions, charitable organizations, you-name-it.
Having loyalty to your employer is laudible but generally misplaced.
Nothing misplaced is laudible.
No one would ever say, "Ignoring the force of gravity is laudible but generally misplaced."
Why? Because ignoring the force of gravity can get you hurt. Likewise, having loyalty to your employer can get you hurt. This is not to say that you shouldn't do good work for what you are paid, but it is morally wrong to give loyalty that is not reciprocated.
From the article: "You party and blow off homework now, but in ten years, you'll be making merely wonderful money as investment bankers and consultants, while I'll be getting laid off from a great job at General Electric."
This is the key to the article. PHB's aren't engineers, don't understand engineeers, and don't like engineers. But they make the hiring and pay decisions that affect engineers. Furthermore, while an engineer is expected to actually build stuff that works or suffer for it, PHB's are often rewarded rather than punished for their failures.
I have no objection to my kids becoming engineers, but I strongly advise them to study business as well, so they're well-prepared to become their own boss, as I am. It's the only way to ensure that as an engineer you aren't beholden to some bozo with an arts degree and a big ego and no actual skills. Of course, you're still beholden to clients, but they come in all shapes and sizes, and after a while you can start to be a bit selective about who you're willing to work for.
rocket-fuel could do it, with amounts of fuel similar to those consumed by a rocket, but then you hadn't really won much, had you ?
Err...no.
Most of the energy in rocket fuel goes in to accelerating rocket fuel. Very little of it goes into the actual payload.
For concreteness, to make 1 kg move at 8000 m/s (LEO), you need 65 MJ. Or to get 1 kg to 36,000 km altitude (GEO)you need about 250 MJ (based on constant g, which is hopelessly conservative). There's over 1 GJ in a gallon of gas, and it takes quite a lot more than 1 GJ of rocket fuel to get 1 kg to orbit.
So for a space elevator you're getting vastly more efficient use of energy than you are for a rocket.
When borderline cases arise, concepts proliferate.
Apart from the Platonists in the audience, intelligent people realize that concepts are made things, artefacts created by humans to facilitate certain types of interaction with the world. Now, the world is a particular way, and that puts constraints on the sorts of concepts that are useful to us, but it doesn't determine a single set of concepts that will do the job. Therefore, concepts vary from person to person, and one person's pornography is another person's erotica, and so on.
Concepts, like all tools, are judged to be better or worse according to use. Some of the uses of "planet" are political--every astronomer monkey wants to be the discoverer of a "plant", because that will attract and impress other monkeys of the complementary sexual orientation. This is just part of our hertiage as monkey's, and we may as well admit it. Other uses are scientific--planetologists already divide planets into sub-categories like "gas giant" and "terrestrial planet", because quite different physical processes dominate these bodies, and distinguishing them allows us to focus our attention more fully on one set of processes or the other. For beings of definitely limited brain power, this is extremely useful.
Historically the term "planet" mixed several completely unrelated things: size, distance from Earth, and being in orbit around the Sun. Planets were "wandering stars", and it just happens that the only things that fell into that category were large bodies far from Earth that orbited the Sun. Things like the Moon, which is close, wasn't a planet because it had a visible disk, which stars do not. But this is entirely accidental--if one of the inner planets had had a moon visible from Earth with the naked eye it is likely that the concept of planet would already be more various than it already is.
I think it better to create a bunch of new terms that acknowledge the rich division of bodies we can now see, rather than get hung up on the historical term "planet". The things we care about include at least three axes: size, composition and orbit. Trying to assign a single word to a particular region of a three-dimensional space (which probably isn't even simply connected!) is a silly waste of time, driven purely by monkey psychology, and has no scientific value. In fact, it may even have negative consequences for science, because getting hung up on historical terms may also help keep people hung up on historical concepts.
So my vote would be to expunge the term "planet" from the astronomical lexicon entirely. It's the only way to be sure.
The satellite in question is clearly a weapon: it is designed to disrupt enemy communications, which are a vital aspect of war-making. But those communications systems are not themselves weapons. Not everything used in war is a weapon, but not all legitimate targets are weapons, either.
Are there still browsers in use that don't recognize the script tag? I haven't run across one in at least five years. Even browseres that don't support JavaScript at least know to ignore the contents of this tag.
You've missed the point: the script and style tags are PCDATA in XHTML, not CDATA. That means comments are not ignored, so your HTMLish scripts and styles, hidden in comment tags, will be invisible to an XHTML user agent. If they aren't, it isn't an XHTML user agent.
Probably technically true, but I've never seen this "SHORTTAG minimisation" discussed anywhere else, and I can't recall ever having dealt with a UA that treats self closing tags in such a manner.
Changing the definition of NET from what is specified in the concrete reference syntax is one of the key tricks that makes XML different from (standard) SGML, and it was known from the very first announcement of XML at SGML96 that this meant that HTML as it then existed was not an XML language.
The big difference between XHTML and HTML is that XHTML is expected to validate, whereas despite the DTDs, HTML is just a bunch of tags strung together by document authors who may well have no knowledge of the existence of those DTDs, much less of their contents. This is why HTML is successful and XHTML probably won't be--users are not going to ever be able to routinely and easily create valid XHTML documents.
We see this in other standards-based information-sharing systems such as DICOM and SQL: what any given implementor specifies as "DICOM compliant" or "SQL compliant" is subject to very signficant variation. That HTML works at all is a triumph of ingenuity, but it works in part because tool vendors have been realistic in their acceptance that humans have a hell of a hard time conforming to standards, and created sloppy, forgiving implementations of their tools to reflects that.
These are blue giants from the sound of it, which means that they are very short-lived (millions of years short-lived.) That means that any scenario in which they stars formed elsewhere and migrated to this region needs to make the migration happen very quickly. Furthermore, unless this is an anomalous situation, this has been going on continuously for the past few billion years.
So which is less probable? Stars forming in a region where we don't expect stars to form, or stars forming in another region and then for some reason being dropped into fast orbits around the central black hole? As near as I can tell, there isn't a whole lot to choose from between these options--both of them involve things that seem implausible given our current understanding of the physics involved.
The density of stars (~400 within a one light-year radius, apparently) is suggestive of star-burst formation. On the other hand, if we posit that there's some kind of attractor dropping stars into these orbits, that might account for the density as well.
The really fun thing is that the very notion of giant black holes in galactic centres was a pretty way-out idea only a dozen years ago. Now, it's almost as if scientists looked at the evidence and changed their minds.
One of the worst products I ever worked on was one that was "designed" by a "designer" who wouldn't have known "third normal form" if it came up and bit her on the ass and said "Hello, I'm third normal form".
This is an example of what I think of as "reach-through": the underlying model will always reach through to the layers over top of it. The degree of reach-through can be minimized, but never eliminated. The "register" keywork in C/C++ is an example of reach-through. No matter how high-level the language is, sometimes the bones of the machine will poke out.
The goal of higher-level tools is to reduce (if sane) or eliminate (if insane) reach-through. Sane higher-level tool designs acknowledge that reach-through will always be with us, and incorporate graceful ways of minimizing it and localizing it. Insane tools try to abstract away the bones of the application entirely, leaving the designer to work with unstructured mush. Not pretty.
The goal of "turning designers into developers" can be achieved only by giving designers some understanding of the underlying layers. Fancy tools can reduce the degree of understanding required, but I'm willing to bet that a designer with a grasp of the underlying model will always be able to use these tools more effectively than one without, and that a designer with no understanding of the underlying model will be able to use the fancy tools to create even more hideous designs faster.
...nothing in history even approaches what we're experiencing right now.
There is nothing unique about the scale of anthropogenic climate forcing.
For example, the Mount Pinatubo erruption resulted in a drop of global temperatures on the range of 0.3 degrees per year over a three year period, for a total drop of over 1 C. This is an enormous impulse forcing, yet global temperatures did not undergo any run-away cooling despite the know proclivity of Earth's current climate for such events.
There is nothing unique in time-scale or magnitude about the current anthropogenic climate forcing. Over the Earth's history we can be sure that both positive and negative forcing events have occured that far outstrip anything humans are currently doing. Recent regional climate fluctuations, such as the little climatic optimum in the North Atlantic region around 1000 CE, and the little ice age that affected the same region half a millenum later, make it clear that climate variation occurs on all sorts of scales in time, space and temperature, for all sorts of reasons.
Ice core and other data, such as paleolimnology-- suggest that interglacial global temperature has a tendency toward bi-modality, with the "hot" state about 5 C warmer than the temperate state we are now in, and lasting about 1000 years on average. Most interglacials show one or more hot transitions of this type. We may be entering one now, and anthropogenic forcing may very well be tipping us in that direction.
But to suggest that there is anything unusual about this is simply mistaken.
It's pretty clear that there is a lot more to the story of biological regulation and inheritance than "DNA encodes proteins".
Two facts:
1) Far more proteins than genes
2) Conserved "non-coding" DNA
Biologists have known the first fact for a long time now--getting on for a decade. When the human genome was sequenced it was obvious that the 32,000 genes weren't sufficient account for the hundreds of thousands of proteins we know exist (I'm personally betting it's into the millions, depending on precisely how you count minor structural variants.)
Why then do we still fixate on the "It's all DNA, one-gene, one-protein" model? Because it's easy, and we don't have anything to replace it with. But it's a blind alley, it's known to be a blind alley, and the next generation of biologists is going to have some fun getting us out of it, if they don't waste all their time trying to find the next miracle drug based on a model that is known to be false.
Some form of RNA-based regulation is entirely plausible as a means of increasing the expressive power of the limited coding regions. Who knows--maybe non-coding regions actually contain encrypted codons, and the RNA is doing decryption during transcription. That could plausibly have evolved as a defense against some kinds of viral attack.
Elaboration on the encoding during transcription is also a virtual certainty--where else are we getting those other 200,000 proteins from? And if it isn't RNA regulating the elaborative process, what is?
"A marshal nobility and a stubborn commons, possessed of arms, tenacious of property, are the only defense of a free constitution against the ambitions of princes."
Gibbon, Decline and Fall of the Roman Empire. Quoted from memory so maybe not precisely accurate.
But the sentiment holds: individual human beings in power always, always, always seek more power. No matter what they call themselves: socialist, conservative, whatever...they will always claim "exceptional circumtances".
But the circumstances are never exceptional. Are western democracies more at risk from external threats today than they were in 1953? I don't think so. So why should we grant powers that weren't available at the height of the Red Scare?
You are absolutely right...smart people are not breeding enough in the first world. Birthrates are now below replacement levels in every advanced country...
Sorry, you've dropped a few sentences or something in editing. Your first sentence is about intelligent individuals. Your second is about nations with the rule of law, stable governments, and effective markets and high standards of living due to technology and history.
These have nothing to do with each other, except that the people living in rich countries, being richer, have better access to education and so may appear "smarter" to the stupid.
If anything, however, people in poor countries are "smarter" than people in rich countries. A person living in poor country is likely to have to actually know how to do something useful to survive, whereas a person in a rich country can just get a job in retail, or sell insurance, or become a lawyer.
Hmm... condescending attitude ("I am not going to spell out all of the theories of Gravity to you")...check.
Gratuitous use of Capitals...check.
Irrelevent invocation of Einstein...check.
Cititation of of "widely thought" theory that no one has ever given significant credence to...check.
Complete absence of calculation to back up any vague claims about what can or cannot be explained by known physics...check.
Really, the quality of Trolls these days just ain't what it used to be.
For what it's worth, there are two forces at work: gravity and some form of van der Waals attraction between adjacent particles, which are 1 - 100 microns in diameter. That gives them quite a lot of surface area in contact, so the forces of adhesion acting between them may be quite signficant. There's something called "vacuum cementing" that is due to significant adhesion in the absence of any gases to muck up surfaces in contact. That may or may not be important here.
It's early days yet, but in the fullness of time I'm sure we'll get a pretty complete picture of cometary structure from missions like this. Science at its best.
Now the only thing keeping Office popular is the lack of interoperability with anything else.
And MS knows this. Gates famous internet memo from '95 highlighted the fact that in a few hours of surfing he didn't find any Microsoft document formats out there, except a few PPT files. That really upset him, because he knows that closed file formats are the drug that MS is pushing.
MS is fighting a rear-guard action on this, and in the end they will lose, because if OOo doesn't win, some other open format will. Closed document formats are increasingly unacceptable to large organizations for very good reasons. As soon as a viable alternative exists there will be a major shift away from MS formats to open formats.
But MS makes its money selling a tool (Office) whose value is fundamentally tied to proprietary file formats. As soon as people start using open formats, they'll have a choice of tools. MS can either make its tool compatible with the open format, or not. Either way, it loses the monopoly pricing ability that it gets now from the fact that MS Office files are the de facto standard of document exchange amongst many businesses.
Because the design of D-T fusion reactors is such that light metals are used almost everywhere the waste produced has a much shorter lifetime than that produced in fission reactors. So even though there are lots of neutrons bouncing around they don't activate as much long-lived waste as they would in a fission pile, which is full of stuff like nickle, iron and uranium.
By the way, the political opposite of communism, is naziism.
Political abstractions, like most abstractions, cannot be defined on a single axis.
Communism has many opposites, the least of which, in every respect, is naziism. Islamic republics are notably anti-communist. Many absolute monarchies would find themselves quite opposed to communist principles. Neither the Crown nor Parliament found themselves very much in favour with the Levelers or Diggers (who were early communists) during the English Civil war.
Likewise, libertarians of various stripes are generally opposed to communism, although put an anarcho-capitalist and a republican minarchist in the same room and you'll soon realize that they are even more opposed to each other.
For that matter, communism is the opposite of communism: the Bolshevics opposed the Menshevics; the Trotskies opposed the Stalinists; the Maoists opposed everybody...
Political abstractions are just like any other abstraction: the subsume concrete instances that are diametrically opposed to other things they also subsume.
One of the remarkable things about the Open Source community, in fact, is how cohesive it it. Despite the free/open/Free arguments, we're all pretty much on the same page, and not just because we are the opposite of Microsoft.
It would obviously be a huge evolutionary advantage -- unless there are some pretty grim side effects.
There is some evidence (work done at the University of Ottawa, in Canada, if memory serves) that scaring and regeneration are complimentary processes: animals that scar don't regenerate, animals that regenerate don't scar. This would make sense if the genes controlling the two processes were the same, and could only be used for one purpose.
If that is the case (walking out on a speculative limb) it makes sense that warm-blooded animals would tend to scar, and cold-blooded animals would tend to regenerate, because scaring is a much faster healing process and warm-blooded animals can't afford much down-time waiting for limbs to regrow because they need to be constantly on the move to get food. Cold-blooded animals just lie around most of the time anyway, so they may as well regrow any missing bits while they're at it.
Is there some nasty side effect that makes it better to NOT have this ability and put up with loss of limbs, and other damage?
There is another mechanism for dealing with major injuries: development of scar tissue. Scaring happens much faster and takes fewer resources than regeneration. There appears to be an anti-correlation between scaring and regeneration: animals that scar don't regenerate and vice-versa, so there may be some overloading of the genes that control both processes, making them mutually incompatible.
Given that survivable loss of limbs and survivable loss of internal organs is a relatively rare occurence for most mammals, it is likely that scaring has been favoured over regeneration in our evolutionary history as it is the mechanism that gives injured organisms the greatest chance of survival.
In particular, mammals lead active lives because we are warm blooded, and therefore need to hunt/scavange/forage regularly for food to keep our body temperature stable. This means that rapid healing is a big advantage, so scaring is favoured. Modern reptile are cold-blooded, and therefore can sustain much longer periods without food, making them more able to take the time out of their busy schedule to regenerate.
Slashdot Mirror
Summary: "If JVMs were smart, garbage collection would be fast."
Reality: "JVMs are mostly very stupid, and you can never be sure what JVM your users are going to use, so in the real world of deployed applications garbage collection performance--and Java performance generally--is a nightmare."
I am so tired of GC advocates talking smugly about theoretical scenarios. Who cares?. When I can run a Java app on an arbitrary JVM and not have it come to a grinding halt every once in a while as the garbage collector runs--or worse yet bring the machine to a grinding halt because the garbage collector never runs--only then will GC will be useful.
The weasel-words in the article are worthy of a PHB: "the garbage collection approach tends to deal with memory management in large batches" Translation: "I wish GC dealt with memory management in large chunks, but it doesn't, so I can't in all honesty say it does, but I can imagine a theoretical scenario where it does, so I'll talk about that theoretical scenario that I wish was real instead of what is actually real."
This is not to say that there aren't one or two decent JVMs out there that have decent GC performance. But having managed a large team that deployed a very powerful Java data analysis and visualization application, and having done work in the code myself, and having had to deal with user's real-world performance issues and having seen the incredible hoops my team had to go through to get decent performance, I can honestly say that up until last year, at least, Java was Not There with regard to GC and performance.
The most telling proof: my team did such a good job and our app was so fast that many users didn't believe it was written in Java. It was users making that judgement, not developers. Users whose only exposure to Java was as users, and whose empirical observation of the language was that it resulted in extremely slow apps. They didn't observe that it was theoretically possible to write slow apps. They observed that it was really, really easy to write slow apps, in the same way it's really easy to write apps that fall over in C++, despite the fact that theoretically you can write C++ apps that never leak or crash due to developers screwing up memory.
Every language has its strengths. Java is a good, robust language that is safe to put into the hands of junior developers to do things that would take a senior developer to do in C++. But its poor performance isn't a myth, nor is its tendency to hog system resources due to poor GC. Those are emprical facts, and this article introduces no actual data to demonstrate otherwise.
As I've pointed out before on
Einstein's contribution was to show that what these others derived from a dynamical theory could be understood in kinematic terms. Dynamics is the study of the causes of motion, and kinematics is the description of motion. In the pre-Einstein theory the resistance of the electron to motion--and the contraction of moving electrons in the direction of motion--was understood as due to electro-magnetic forces acting on it due to the aether. What Einstein showed was that the same phenomena could be understood in purely kinematic terms, as a consequence of the way motion must be described if the laws of physics are to be the same for all observers.
To get a sense of how profound this is, imagine that at one time the inverse-square law for light had been understood in terms of an absorbing medium. That is, the fact that lights appeared dimmer as the square of the distance to the observer was explained by empty space being filled with a substance that absorbed light. There would be many difficulties with such a theory, but I'm sure with sufficient mathematical prowess one could make it work. Then someone like Einstein comes along and points out that one can explain the phenomenon in purely geometric terms, as a consequence of the way the light is spreading out over the surface of a larger sphere as it gets further from the source. What previously required a complex, difficult mathematical description now becomes so trivial that even a philosopher can understand it.
That was Einstein's contribution, but it shouldn't completely eclipse the work of those who came before.
The UN would "force" them the same way they forced Saddam to disarm. Many years of weakly worded resolutions and loud bellyaching.
Your post implies that Saddam was armed, and armed with WMDs, as those were the primary target of UN resolutions.
That is false. Iraq had no WMDs, nor any plans to build them, nor any facilities capable of building them.
So it would appear that all those weakly worded resolutions might have had an affect after all, although in many respects the whole sanctions regime, oil-for-food, etc., was a disaster.
Please tell me I'm not the only one who read that as "Pointy-Haired-tits".
You're not alone, although I skipped the "haired" and read it as "pointy tits" and thought, "whoa, that's a workplace distraction I could use!"
i found out that happiness is just a balance of the right drugs.
And satiation is "just" a matter of good food in appropriate amounts.
This, and a number of other posts, suggest that the experience of happiness is not "real" somehow, because it is subjective, or subject to chemical intervention, or something.
But we are real. What we experience is real. What we experience is causally connected to the material world that we are inseparably part of. This does not make the experience unreal. It means that happiness, like life, is a property of matter.
No one says, "I used to think that birds could fly, but then I found out it was just their wing structure." Flight is a capacity of matter, no less than happiness. Put matter in the right configuration (a seagull, say) and it'll take off every time. This does not make flight unreal.
So why does anyone think that happiness is any less real than mass or pH?
False. Forcing them to have sex with you was explicitly permitted, and there were rules governing it:
You will note that there is no mention anywhere of the woman's consent. Ergo, this is nothing but a permit to rape, so long as you let your rape victim mourn her dead family for a month. And if you didn't enjoy raping her it says you can kick her out of your house, but not sell her into slavery.
Look at it from her point of view: you've over-run her city, killed her family, taken her captive, left her alone for a month and then forced her to have sex with you. Forcing someone to have sex without their consent is rape. Rape by elaborate rules is still rape, and the Bible clearly and unequivocally condones it.
Timecards reflect essential truth, if not literal truth of when work is done.
Timecards measure inputs, not outputs. Measuring inputs and assuming they serve as adequate surrogates for outputs is bad engineering and bad management.
Case in point: at Three Mile Island the control room systems reported that a given valve was closed when in fact it was locked solidly open. The problem was that the system was designed to measure current running to the motor that controlled the valve, which has an extremely weak relationship to the movement of the valve. Both mechanical and electrical failures could decouple the input and the output, and did.
So one of the most important things about dealing with suits is to make sure you measure outputs, and make sure the suits know that your team has good outputs for the inputs (ie. high productivity.)
If you're challenged on your team not having low enough productivity (ie. not working long enough hours) it is important to have the latest output measures at hand, and to point out that maximum productivity is achieved at around 35 hours per week. It is also important to be able to cite the extensive studies across many industries that back up that uncontroversial fact. If anyone ever talks in a meeting about the number of hours they work, or their team works, as if that was a good thing, cut them off immediately with "On my team we focus on outputs, not inputs..." NEVER let anyone get away with pretending that long hours are anything other than low productivity.
I am an extremely quantitative manager, and the people who have worked for me love it, and the people who I have worked for hate it. It shorts out all their monkey heirarchy circuits by actually focussing on what the business is supposed to be doing (being productive) rather than on what it is actually doing (stroking the monkey egos of managers and execs.)
Lest anyone think this is an anti-business rant, I should point out that I think these problems are universal human problems. They can be found in political parties, labour unions, charitable organizations, you-name-it.
Having loyalty to your employer is laudible but generally misplaced.
Nothing misplaced is laudible.
No one would ever say, "Ignoring the force of gravity is laudible but generally misplaced."
Why? Because ignoring the force of gravity can get you hurt. Likewise, having loyalty to your employer can get you hurt. This is not to say that you shouldn't do good work for what you are paid, but it is morally wrong to give loyalty that is not reciprocated.
From the article: "You party and blow off homework now, but in ten years, you'll be making merely wonderful money as investment bankers and consultants, while I'll be getting laid off from a great job at General Electric."
This is the key to the article. PHB's aren't engineers, don't understand engineeers, and don't like engineers. But they make the hiring and pay decisions that affect engineers. Furthermore, while an engineer is expected to actually build stuff that works or suffer for it, PHB's are often rewarded rather than punished for their failures.
I have no objection to my kids becoming engineers, but I strongly advise them to study business as well, so they're well-prepared to become their own boss, as I am. It's the only way to ensure that as an engineer you aren't beholden to some bozo with an arts degree and a big ego and no actual skills. Of course, you're still beholden to clients, but they come in all shapes and sizes, and after a while you can start to be a bit selective about who you're willing to work for.
rocket-fuel could do it, with amounts of fuel similar to those consumed by a rocket, but then you hadn't really won much, had you ?
Err...no.
Most of the energy in rocket fuel goes in to accelerating rocket fuel. Very little of it goes into the actual payload.
For concreteness, to make 1 kg move at 8000 m/s (LEO), you need 65 MJ. Or to get 1 kg to 36,000 km altitude (GEO)you need about 250 MJ (based on constant g, which is hopelessly conservative). There's over 1 GJ in a gallon of gas, and it takes quite a lot more than 1 GJ of rocket fuel to get 1 kg to orbit.
So for a space elevator you're getting vastly more efficient use of energy than you are for a rocket.
When borderline cases arise, concepts proliferate.
Apart from the Platonists in the audience, intelligent people realize that concepts are made things, artefacts created by humans to facilitate certain types of interaction with the world. Now, the world is a particular way, and that puts constraints on the sorts of concepts that are useful to us, but it doesn't determine a single set of concepts that will do the job. Therefore, concepts vary from person to person, and one person's pornography is another person's erotica, and so on.
Concepts, like all tools, are judged to be better or worse according to use. Some of the uses of "planet" are political--every astronomer monkey wants to be the discoverer of a "plant", because that will attract and impress other monkeys of the complementary sexual orientation. This is just part of our hertiage as monkey's, and we may as well admit it. Other uses are scientific--planetologists already divide planets into sub-categories like "gas giant" and "terrestrial planet", because quite different physical processes dominate these bodies, and distinguishing them allows us to focus our attention more fully on one set of processes or the other. For beings of definitely limited brain power, this is extremely useful.
Historically the term "planet" mixed several completely unrelated things: size, distance from Earth, and being in orbit around the Sun. Planets were "wandering stars", and it just happens that the only things that fell into that category were large bodies far from Earth that orbited the Sun. Things like the Moon, which is close, wasn't a planet because it had a visible disk, which stars do not. But this is entirely accidental--if one of the inner planets had had a moon visible from Earth with the naked eye it is likely that the concept of planet would already be more various than it already is.
I think it better to create a bunch of new terms that acknowledge the rich division of bodies we can now see, rather than get hung up on the historical term "planet". The things we care about include at least three axes: size, composition and orbit. Trying to assign a single word to a particular region of a three-dimensional space (which probably isn't even simply connected!) is a silly waste of time, driven purely by monkey psychology, and has no scientific value. In fact, it may even have negative consequences for science, because getting hung up on historical terms may also help keep people hung up on historical concepts.
So my vote would be to expunge the term "planet" from the astronomical lexicon entirely. It's the only way to be sure.
Or the map that a contractor carries that could possibly find its way into the hands of a soldier, is a weapon.
Or a government-issue visitor's map that finds it's way into the hands (or rather shared-use truck) of a driver who once served with mujahedeen militia in Afghanistan in the 1990s, is a weapon.
The satellite in question is clearly a weapon: it is designed to disrupt enemy communications, which are a vital aspect of war-making. But those communications systems are not themselves weapons. Not everything used in war is a weapon, but not all legitimate targets are weapons, either.
Are there still browsers in use that don't recognize the script tag? I haven't run across one in at least five years. Even browseres that don't support JavaScript at least know to ignore the contents of this tag.
You've missed the point: the script and style tags are PCDATA in XHTML, not CDATA. That means comments are not ignored, so your HTMLish scripts and styles, hidden in comment tags, will be invisible to an XHTML user agent. If they aren't, it isn't an XHTML user agent.
Probably technically true, but I've never seen this "SHORTTAG minimisation" discussed anywhere else, and I can't recall ever having dealt with a UA that treats self closing tags in such a manner.
Changing the definition of NET from what is specified in the concrete reference syntax is one of the key tricks that makes XML different from (standard) SGML, and it was known from the very first announcement of XML at SGML96 that this meant that HTML as it then existed was not an XML language.
The big difference between XHTML and HTML is that XHTML is expected to validate, whereas despite the DTDs, HTML is just a bunch of tags strung together by document authors who may well have no knowledge of the existence of those DTDs, much less of their contents. This is why HTML is successful and XHTML probably won't be--users are not going to ever be able to routinely and easily create valid XHTML documents.
We see this in other standards-based information-sharing systems such as DICOM and SQL: what any given implementor specifies as "DICOM compliant" or "SQL compliant" is subject to very signficant variation. That HTML works at all is a triumph of ingenuity, but it works in part because tool vendors have been realistic in their acceptance that humans have a hell of a hard time conforming to standards, and created sloppy, forgiving implementations of their tools to reflects that.
These are blue giants from the sound of it, which means that they are very short-lived (millions of years short-lived.) That means that any scenario in which they stars formed elsewhere and migrated to this region needs to make the migration happen very quickly. Furthermore, unless this is an anomalous situation, this has been going on continuously for the past few billion years.
So which is less probable? Stars forming in a region where we don't expect stars to form, or stars forming in another region and then for some reason being dropped into fast orbits around the central black hole? As near as I can tell, there isn't a whole lot to choose from between these options--both of them involve things that seem implausible given our current understanding of the physics involved.
The density of stars (~400 within a one light-year radius, apparently) is suggestive of star-burst formation. On the other hand, if we posit that there's some kind of attractor dropping stars into these orbits, that might account for the density as well.
The really fun thing is that the very notion of giant black holes in galactic centres was a pretty way-out idea only a dozen years ago. Now, it's almost as if scientists looked at the evidence and changed their minds.
One of the worst products I ever worked on was one that was "designed" by a "designer" who wouldn't have known "third normal form" if it came up and bit her on the ass and said "Hello, I'm third normal form".
This is an example of what I think of as "reach-through": the underlying model will always reach through to the layers over top of it. The degree of reach-through can be minimized, but never eliminated. The "register" keywork in C/C++ is an example of reach-through. No matter how high-level the language is, sometimes the bones of the machine will poke out.
The goal of higher-level tools is to reduce (if sane) or eliminate (if insane) reach-through. Sane higher-level tool designs acknowledge that reach-through will always be with us, and incorporate graceful ways of minimizing it and localizing it. Insane tools try to abstract away the bones of the application entirely, leaving the designer to work with unstructured mush. Not pretty.
The goal of "turning designers into developers" can be achieved only by giving designers some understanding of the underlying layers. Fancy tools can reduce the degree of understanding required, but I'm willing to bet that a designer with a grasp of the underlying model will always be able to use these tools more effectively than one without, and that a designer with no understanding of the underlying model will be able to use the fancy tools to create even more hideous designs faster.
...nothing in history even approaches what we're experiencing right now.
There is nothing unique about the scale of anthropogenic climate forcing.
For example, the Mount Pinatubo erruption resulted in a drop of global temperatures on the range of 0.3 degrees per year over a three year period, for a total drop of over 1 C. This is an enormous impulse forcing, yet global temperatures did not undergo any run-away cooling despite the know proclivity of Earth's current climate for such events.
There is nothing unique in time-scale or magnitude about the current anthropogenic climate forcing. Over the Earth's history we can be sure that both positive and negative forcing events have occured that far outstrip anything humans are currently doing. Recent regional climate fluctuations, such as the little climatic optimum in the North Atlantic region around 1000 CE, and the little ice age that affected the same region half a millenum later, make it clear that climate variation occurs on all sorts of scales in time, space and temperature, for all sorts of reasons.
Ice core and other data, such as paleolimnology-- suggest that interglacial global temperature has a tendency toward bi-modality, with the "hot" state about 5 C warmer than the temperate state we are now in, and lasting about 1000 years on average. Most interglacials show one or more hot transitions of this type. We may be entering one now, and anthropogenic forcing may very well be tipping us in that direction.
But to suggest that there is anything unusual about this is simply mistaken.
Yes.
It's pretty clear that there is a lot more to the story of biological regulation and inheritance than "DNA encodes proteins".
Two facts:
1) Far more proteins than genes
2) Conserved "non-coding" DNA
Biologists have known the first fact for a long time now--getting on for a decade. When the human genome was sequenced it was obvious that the 32,000 genes weren't sufficient account for the hundreds of thousands of proteins we know exist (I'm personally betting it's into the millions, depending on precisely how you count minor structural variants.)
Why then do we still fixate on the "It's all DNA, one-gene, one-protein" model? Because it's easy, and we don't have anything to replace it with. But it's a blind alley, it's known to be a blind alley, and the next generation of biologists is going to have some fun getting us out of it, if they don't waste all their time trying to find the next miracle drug based on a model that is known to be false.
Some form of RNA-based regulation is entirely plausible as a means of increasing the expressive power of the limited coding regions. Who knows--maybe non-coding regions actually contain encrypted codons, and the RNA is doing decryption during transcription. That could plausibly have evolved as a defense against some kinds of viral attack.
Elaboration on the encoding during transcription is also a virtual certainty--where else are we getting those other 200,000 proteins from? And if it isn't RNA regulating the elaborative process, what is?
"A marshal nobility and a stubborn commons, possessed of arms, tenacious of property, are the only defense of a free constitution against the ambitions of princes."
Gibbon, Decline and Fall of the Roman Empire. Quoted from memory so maybe not precisely accurate.
But the sentiment holds: individual human beings in power always, always, always seek more power. No matter what they call themselves: socialist, conservative, whatever...they will always claim "exceptional circumtances".
But the circumstances are never exceptional. Are western democracies more at risk from external threats today than they were in 1953? I don't think so. So why should we grant powers that weren't available at the height of the Red Scare?
You are absolutely right...smart people are not breeding enough in the first world. Birthrates are now below replacement levels in every advanced country...
Sorry, you've dropped a few sentences or something in editing. Your first sentence is about intelligent individuals. Your second is about nations with the rule of law, stable governments, and effective markets and high standards of living due to technology and history.
These have nothing to do with each other, except that the people living in rich countries, being richer, have better access to education and so may appear "smarter" to the stupid.
If anything, however, people in poor countries are "smarter" than people in rich countries. A person living in poor country is likely to have to actually know how to do something useful to survive, whereas a person in a rich country can just get a job in retail, or sell insurance, or become a lawyer.
Hmm... condescending attitude ("I am not going to spell out all of the theories of Gravity to you")...check.
Gratuitous use of Capitals...check.
Irrelevent invocation of Einstein...check.
Cititation of of "widely thought" theory that no one has ever given significant credence to...check.
Complete absence of calculation to back up any vague claims about what can or cannot be explained by known physics...check.
Really, the quality of Trolls these days just ain't what it used to be.
For what it's worth, there are two forces at work: gravity and some form of van der Waals attraction between adjacent particles, which are 1 - 100 microns in diameter. That gives them quite a lot of surface area in contact, so the forces of adhesion acting between them may be quite signficant. There's something called "vacuum cementing" that is due to significant adhesion in the absence of any gases to muck up surfaces in contact. That may or may not be important here.
It's early days yet, but in the fullness of time I'm sure we'll get a pretty complete picture of cometary structure from missions like this. Science at its best.
Now the only thing keeping Office popular is the lack of interoperability with anything else.
And MS knows this. Gates famous internet memo from '95 highlighted the fact that in a few hours of surfing he didn't find any Microsoft document formats out there, except a few PPT files. That really upset him, because he knows that closed file formats are the drug that MS is pushing.
MS is fighting a rear-guard action on this, and in the end they will lose, because if OOo doesn't win, some other open format will. Closed document formats are increasingly unacceptable to large organizations for very good reasons. As soon as a viable alternative exists there will be a major shift away from MS formats to open formats.
But MS makes its money selling a tool (Office) whose value is fundamentally tied to proprietary file formats. As soon as people start using open formats, they'll have a choice of tools. MS can either make its tool compatible with the open format, or not. Either way, it loses the monopoly pricing ability that it gets now from the fact that MS Office files are the de facto standard of document exchange amongst many businesses.
Because the design of D-T fusion reactors is such that light metals are used almost everywhere the waste produced has a much shorter lifetime than that produced in fission reactors. So even though there are lots of neutrons bouncing around they don't activate as much long-lived waste as they would in a fission pile, which is full of stuff like nickle, iron and uranium.
By the way, the political opposite of communism, is naziism.
Political abstractions, like most abstractions, cannot be defined on a single axis.
Communism has many opposites, the least of which, in every respect, is naziism. Islamic republics are notably anti-communist. Many absolute monarchies would find themselves quite opposed to communist principles. Neither the Crown nor Parliament found themselves very much in favour with the Levelers or Diggers (who were early communists) during the English Civil war.
Likewise, libertarians of various stripes are generally opposed to communism, although put an anarcho-capitalist and a republican minarchist in the same room and you'll soon realize that they are even more opposed to each other.
For that matter, communism is the opposite of communism: the Bolshevics opposed the Menshevics; the Trotskies opposed the Stalinists; the Maoists opposed everybody...
Political abstractions are just like any other abstraction: the subsume concrete instances that are diametrically opposed to other things they also subsume.
One of the remarkable things about the Open Source community, in fact, is how cohesive it it. Despite the free/open/Free arguments, we're all pretty much on the same page, and not just because we are the opposite of Microsoft.
It would obviously be a huge evolutionary advantage -- unless there are some pretty grim side effects.
There is some evidence (work done at the University of Ottawa, in Canada, if memory serves) that scaring and regeneration are complimentary processes: animals that scar don't regenerate, animals that regenerate don't scar. This would make sense if the genes controlling the two processes were the same, and could only be used for one purpose.
If that is the case (walking out on a speculative limb) it makes sense that warm-blooded animals would tend to scar, and cold-blooded animals would tend to regenerate, because scaring is a much faster healing process and warm-blooded animals can't afford much down-time waiting for limbs to regrow because they need to be constantly on the move to get food. Cold-blooded animals just lie around most of the time anyway, so they may as well regrow any missing bits while they're at it.
Is there some nasty side effect that makes it better to NOT have this ability and put up with loss of limbs, and other damage?
There is another mechanism for dealing with major injuries: development of scar tissue. Scaring happens much faster and takes fewer resources than regeneration. There appears to be an anti-correlation between scaring and regeneration: animals that scar don't regenerate and vice-versa, so there may be some overloading of the genes that control both processes, making them mutually incompatible.
Given that survivable loss of limbs and survivable loss of internal organs is a relatively rare occurence for most mammals, it is likely that scaring has been favoured over regeneration in our evolutionary history as it is the mechanism that gives injured organisms the greatest chance of survival.
In particular, mammals lead active lives because we are warm blooded, and therefore need to hunt/scavange/forage regularly for food to keep our body temperature stable. This means that rapid healing is a big advantage, so scaring is favoured. Modern reptile are cold-blooded, and therefore can sustain much longer periods without food, making them more able to take the time out of their busy schedule to regenerate.