That USED to be the beauty of the place, a long time ago. Fry's has taken what little electronic hobbist store business there is, and the rest is all by catalog, sadly. I don't think there are enough electronic hobbists in the U.S. today to support a nationwide chain of stores catering to that. Someone or ones in Radio Shack management came to that conclusion back in the 80's after the PC market consolidated (remember the Trash-80?), and the chain has tried to remake itself into a mass market cheap electronic gadget distributor ala Best-Buy and P.C. Richard, replacing employees who knew how to fix and build things with the "You want fries with that?" crowd. It has to date failed rather miserably at this task, which relys on massive stores with room for both inventory and selection of "consumer electronics" and doesn't give a rat's ass about hobbists any more.
At least, that's my perception of them here in New England and in my frequent visits to Texas...
The Administration's Public Relations philosophy:
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NASA Science Under Attack
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· Score: 1, Flamebait
"Think of the press as a great keyboard on which the government can play. "
It's nice to see someone else who gets the idea that science is FUN because we really don't know until we look! While it's great we've figured out quite a bunch, the interesting, fun, fascinating part is the stuff we haven't tested quite yet - that's where the excitement is, and that we can't know a priori what is a good theory and what is not until we do.
Well, science has also postulated the existence of the anti-electron (Dirac), electromagnetic waves (Hertz), and missing elements like Eka-aluminum aka Gallium (Mendeleev), all without actual "evidence" for their existence at the time the theories were proposed. Then, once the theories were put out there, people tried experiments to see if the theories' predicitions were true. If they were, great theory! If not? Oh well, that's how it goes. Aether was one of the "that's how it goes" ones, but it wasn't invented because the theories were "inadequate", it was invented because it explained all the evidence accumulated up to that point in a theoretical framework pretty well. One of it's predictions (that the speed of electromagnetic waves would vary depending on the motion of the earth through the aether) turned out to be wrong, (as demonstrated my Michelson and Morley), but until the experiment was done, nobody could have known that! And the implications of that were so shocking and anti-intutitive, that it took an Einstein to boldly speculate that there was no aethereal medium for light waves, but instead our conceptions of time and space were off. There was no actual evidence for mass increases with motion nor length contraction either when Einstein came up with Special Relativity - that came later, after his theory suggested people look for those phenomenia. If experimentalists DIDN'T FIND THEM WHEN THEY LOOKED, then relativity too would have gone into the dustbin. But you can't know that ahead of time.
That's how science works, if it just "explains" (condenses into a few formulae/models) that which has already been observed, it's a bit useless. It HAS to make hypotheses beyond the actual evidence if it is to have any value as a predictive tool - this is why faslfyability is so important. If you can't falsify it, you haven't predicted anything, and therefore it's kinda useless.
BTW, I tend to agree with you about dark matter - it does seem to be awfully omnipresent yet remarkably undetectable. But then again, so is the neutrino! That's the exciting part, we don't know yet. It could still go either way. Wouldn't it be boring otherwise?
That's the amusing part; as far as I understand it, no. The whole dark matter thing is rather touchy because of this - it describes something that only interacts via gravity. Remember that our sense of "interaction" (touching, burning, etc.) are all based on electromagnetic forces, so this dark matter could be passing through us right now and we would not notice it (much like neutrinos, which pass through us by the billions per second). Of course, at least neutrinos have the decency to OCCASIONALLY interact with normal matter, or we would have never detected them at all, only hypothesized their existence to make various important laws (like conservation of momentum and particle spin) work.
It's an intriguing idea, though. The reason ordinary matter piles up into big chunks like planets and stars is not just gravity, but the OTHER forces that keep it "stuck" together. Without that, matter would just be cruising along, looping around due to gravity, perhaps even "colliding", but without a method of storing or dissipating their kinetic energy (chemical bonds, which allow "heat" or vibrational motion energy), they will never stop moving or agglomerate or anything like that, making them more like a perfect gas without a container but with gravity. Neat stuff.
I just hope there is some way of directly detecting this dark matter (have it interact with something in a particle chamber in such a way that dark matter is required to explain the observation), or at least have it fall naturally out of the Standard Model or a successor, or it is going to have an aethereal feel (pun intended) about it.
Actually, Godel did no such thing - he demonstrated that in any formal system of logic sufficiently complex to encapsulate basic arithmetic, there will be unprovable statements which are nonetheless true. Note that the reason we can say these unprovable statements are true is because that if they were false, there would exist a provable counterexample to the statement (i.e. an example of the falseness), and thus the statement would not be unprovable - but this knowledge comes from outside the logical system. In other words, he demonstrated that there will be true statements in a logical system that can never be proven within that system to be true; a hypothetical example might be Goldbach's conjecture, that any even number > 4 is the sum of two (not necessarily distinct) primes. If this was, in fact, true, but was somehow "unprovable", we would be left in the uncomfortable position of seeing billions of examples where it is true, not a single example where it was false, but of course there would always be an infinity of cases we didn't check yet. This is, in fact, the present state of our knowledge - and thus why I used it as an example. Of course, some clever egg might stumble upon a proof of Goldbach's conjecture tomorrow - people used to use Fermat's Last Theorem as a potential example of something that might be true but unprovable, until Wiles proved it. This is the problem, that we have no way of knowing what is unprovable in mathematics, because if we did have such a way of "knowing" (i.e. proving that a proposition is unprovable) for a specific proposition, we would have just proven it true, and thus it would not be unprovable! So we will never know what is not provable - we will only suspect that one of Godel's unprovable but true phantasms is staring us in the face.
My point (longwindedly) is that this has little or nothing to do with the physical, mathematically modeled, problems at hand here; if you want a better idea of the type of barrier we are facing in this case, you would be better served by complexity and information theory; look up Shannon and Chaitin for more info - that is the type of problem involved in turbulence simulation, not logical issues of provability and incompleteness.
In a sense, you are right, but It's worse than that. In all the other cases, we have models of the phenomenon that (in many cases) are partially derived from second principles (the gas laws, Navier-Stokes equations, etc.). Unfortunately, turbulence in a fluid flow is apparently unamenable to modeling with those laws - they pretend that a fluid is grainless and infinitely divisible (no atoms/molecules), and wrap up the more complex intermolecular forces under the viscosity term. Turbulence (apparently) is fundamentally related to the way individual molecules interact, and we simply don't have models that can handle this in the quantites ( > 10^10 molecules being simulated) required. In other words, we can not predict turbulence in a fluid flow from first principles (intermolecular forces - i.e. quantum interactions); we have an empirical understanding of them only.
As for the turbulence in airplanes, there is some limited prediction done, but it is based on some common sense ideas, such as when the wind direction/speed changes rapidly with a change in either vertical or lateral position, there will tend to be turbulence (such as going from the core of a jet stream to the outside of one).
I remember it because I thought it was so bizzare, and because I had no idea there was a black market in young boys who were good camel jockeys. Weird.
...when directly interested parties are involved. This is the problem with Wikipedia. In a jury trial, great pains are taken to assure that the juries consist only of people without any personal interest or attachment to the outcome; this seems to be an inherently time-consuming and expensive process.
Up until recently, Wikipedia has relied on the fact that it was relatively unknown outside the geek population, and so the odds were that highly agendized individuals were not drawn to it as a priority. This, unfortunately, has changed with Wikipedia's popularity.
This is what makes/., Wiki, and all the other attempts at what ruleset allows a productive, participatory, democratic system that results in the best knowledge interesting - nobody has hit upon the right answer yet, but we are learning and getting better by watching what does and doesn't work. If only we could apply this to something like voting! Unfortunately, WAY too many overinterested parties are already assuring that almost any change to the voting system that gets implemented will make it worse from the voter's point of view.
One: As to your resigning, cheers. It's one thing to bitch about a problem, it's quite another to put one's job on the line (or in your case, take it off line). There appear to be many/.ers who casually say how the engineers in question should have walked off the job, not allowed the launch, etc., when in fact, it is never quite so easy. I hope you have the good fortune to soon work for a firm that appreciates and respects your integrity, and I hope you sleep easier at night.
Two: As for the specs, the boosters were OUT of the original spec, which said that there should be NO burn-off of the O-rings, as they were supposedly completely sealed from the combustion chamber by a ring of putty. Unfortunately, for reasons unknown, the putty would develop holes which would allow hot gas to escape and start to erode away the O-rings, as revealed by post flight inspections. Did they track down the cause? Not really, but then they came up with a nice empirically derived curve of the O-ring burn depth that was fitted to the data points, and concluded since the average burn depth was 1/3 of the amount needed to cause O-ring failure, they had a safety factor of 3. I kid you not. Here is the link, on NASA's web site, of the appendix to the Rodgers report by Richard Feynman, who gives the most lucid explanation of what safety oriented engineering should be, and how NASA disregarded it.
It seems the main thing that distinguishes Jobs, according to the slideshow, is that he knows his companies' products to the point where he is unafraid to get involved with them at any level from suppliers of suppliers to design to marketing. In other words, he thoroughly knows his business.
A CEO who thoroughly knows his business redefines what a CEO is? This merely highlights the disease that has infected much of corporate America, namely that you don't have to know shit about your business or product, all you have to know is how to manage people, whatever that means.
This is about as effective as the idea that you don't have to know jack about math, or physics, or history in order to teach them; all you have to be is a good teacher, whatever the hell that means.
News Flash: Intelligence, experience, knowledge and motivation are far more important in running a company than an MBA. Steve Jobs illustrates this. News at 11.
I think to some extent Apple and Microsoft are reflections of Jobs and Gates.
Microsoft has done much in the computer world, but I don't think many would accuse them of being innovative, and I think that is a reflection of Gates - he sees practical opportunities to sell product, or take an idea and make it profitable. He just never seemed that creative.
Perhaps he is bored now. Love them or hate them, Microsoft is the dominant player in the computer industry by far. That's a boring place to be, after a while. Microsoft is unfocused today, much like Bill is. A mid-life crisis, you might say. And Gates is trying to use the insane amounts of money he has aquired for something other than aquiring more insane amounts of money or implementing more of other people's ideas. He wants to get meaning in his life, and helping others gives a sense of meaning that he probably doesn't get from computers any more.
Jobs, on the other hand, still loves computers, and loves Apple. After his near death experience with pancreatic cancer, I think he gets a charge out of leading the pack with new ideas and trying new things. Plus, Apple has a lot further up to go than Microsoft does.
Rich people usually don't get generous until they start Wondering About the Meaning of It All. Bill's wondering, and Jobs has already figured it out. In Jobs' case, it involves Apple rather than other people.
...to come up with justifications for a course of action that would vastly enrich you. All you have to mutter are the magic words, "maximize shareholder profit". IBM made the similar arguments working for Nazi Germany, and pointed out they made plenty of contributions to the Allies as well. Scientists throughout both world wars on all sides justified their work on war weaponry (poison gas, atomic weapons, incendiary bombs, etc.) in terms of, "if it shortens the war, less people will die, so this is good."
Of course, these justifications usually have a nugget of truth in them, or they wouldn't salve the consciences of the people coming up with them.
I don't know if Google is doing evil, but they sure aren't doing good here.
I generally don't respond to AC's, but I'll make an exception in your case because you completely missed most of the subtleties of the situation. The calculation was not, "Wow, look, there is a 0.92375% chance of the shuttle going "Boom!"; it was more like an order of magnitude estimate based on guesswork and engineering experience, which is much harder to justify. Safety engineering, piloting, and other "veto for safety" situations based on operational experience rather than a fill-in-the-blanks-out-spits-probability situations, are inherently difficult ones. This is because the odds are, 99% of the time, things will be okay, and if you are the "bad guy" and hold things up, and they work out fine for your replacement (as they will, 99% of the time), in a manager's mind (unless he is really good), YOU are the problem, not the situation you said was unsafe. It's the 100th time that catches you. Or the 101st. Or the 1000th. That's the problem - safety is not a device or a simple calculation, and it is not proven to have existed because of a successful outcome - it is an attitude towards limits and the unexpected, and what is a reasonable risk vs. the return and what is not.
As for your comment regarding war and acceptable losses, that's fine. But the point was that the shuttle could have been MUCH safer (by three orders of magnitude) if the engineers' advice was sacrosanct, with little loss of productivity. Is getting a 30% increase in flights per year worth an increase of x1000 times risk of hull loss?
I'm glad some other/.ers know about Feynman's crucial role in the Challenger investigation. Feynman also goes into great depth about his feelings writing the report, and other insights about the whole process in his book, "What do you care what other people think? More adventures of a curious character" - highly recommended. Feynman was substiantially more critical of NASA than the other people writing the report, and almost decided to have his name removed until he was allowed to put his conclusions, unedited, into an addendum to the offical report.
You know that famous line of his, "Nature cannot be fooled?" - it's from the coda to that report.
Thank you for the kind comment - it is nice to know that I am not the only one for whom a library at home was an essential part of growing up. I too have about 60 boxes of books waiting to be put into my new apartment when I am done moving! I didn't realize how much of an "instinct" my book collection habits were until I was packing to move and realized that my books took up more boxes than all the rest of my possessions put together. That, and a mover remarked about my "book hobby" - I never thought of it as a hobby before...
I recently had to go through my father's old library (my father died many years ago, and my mother just sold the family house and "downsized" into a nice, cozy apartment, with little room for "extra" books), and of course I decided to keep most of his old books, even though I may never read them. Many of them I was very familiar with; books on sailing (he was a sailor for many years), history (WWII specifically - he immigrated to the US in '39 as a direct result of Hitler), and many art books. But then there were all these quirky fiction books by (I forget the exact name) Gabriel Marquez? Apparently he was known as a master of a "fantasy" fiction style popular in South America; I had never even heard of him until I came upon these old books. One day I'm going to read them, and a part of my father's world I never knew about will be part of mine as well.
Perhaps that's the appeal, that a book is a small world, and there is something to be treasured about them even if any particular one is not your cup of tea. But that makes an awful lot of small worlds you can have in one small room.
My complements to you as well. I hope you have kids someday - I think the world needs more kids lucky enough to have a wise parent or two.
You would be surprised. Remember, your typical American ruler is broken into binary fractions of an inch (1/2, 1/4, 1/8, and usually 1/16 is the smallest). In order to measure something to less than a whole inch, you have to be familiar with those fractions, how they convert, how to count them, and so forth. I can personally attest to the fact that many kids have no idea what exactly all the submarkings below an inch mean. They have a hard time memorizing the powers of two, which you probably take for granted, so they have to count how many marks there are to know the denominator of the fraction, remember that, then recount how many marks they move over to the edge of the thing they are measuring.
Sounds complicated when you describe it like this, doesn't it? You probably learned it at such a young age that you don't remember a time when it didn't make sense or you had to think about it.
Another sign of this is a somewhat new breakdown in the clothing and fashion industry. It used to be that there were just Fashion Designers, who controlled the making of a garment from mental conception all the way to the fractions of an inch, stitches per inch, seam width, etc., that were given to the manufacturers of garments. Nowadays, there are Fashion Designers, and Tech Designers. The Fashion Designer has the "creative" part, and the Tech designer is the one who translates that into inches, stitches, fabrics and so forth! In other words, the ability to handle numbers, fractions, and measurements is now considered difficult enough to render a new job position. I know this because my mother has been in the garmento industry for 40+ years. She is now a tech designer, because nobody wants to do that icky math stuff; all the FIT graduates want to be "creative" designers. Not suprisingly, tech designers typically get paid about 2 to 3 times more than fashion designers.
When I was younger, I was raised in a household with a library. It wasn't a very big house, but the library room was important; this is where my dad would sit and read, and I could do so as well. It never had to be said directly to me (at least, not that I remember), I just understood that the books were important, they were there to be read, and that was an important way to learn about the world. The books were knowledge, and that knowledge was respected. Whenever we visited someone else's house, I would always look at their library, because my father said you can learn a lot about a person by seeing what kind of books they read. A house without books was not a home to me.
Now, I visit people living in McMansions in various parts of the US, and I find many of them have no library, even though there is far more room for one if they so chose. Not surprisingly, their kids have little interest in reading, because their parents don't read, yet are "successful" - i.e. they have the McMansion and stuff to fill it. What conclusion do you think most kids today will come to?
"Success" and education APPEAR more uncoupled in today's world than they used to be - and that is awfully hard for even the best teachers to overcome. The people who are drawn to knowledge for its own beauty have always been a very small minority; for the rest, education is interesting to the extent it is rewarding. If the rewards appear less, the education is less interesting and devolves into seeking the form (degrees) rather than the substance.
Btw, I used to tutor kids in their homes for many years, so I have some experience/bias when it comes to how kids are educated....
I'm not quite sure what you mean by calculus when you say you "[found] shortcuts for algebraic equations in the 7th grade." - I presume you mean shortcuts for solving them. Calculus has nothing to do with solving ordinary equations; it devises new functions, new operations you can do on functions, and thus new kinds of equations that were unexpressible without it (ODE's, PDE's, fxns defined by integrals, etc.).
When you say you "aggressive"ly tried to find the most effecient geometry, and that you prefer geometrical balance over "Feng shui, symmetrical balance and all that garbage", it comes across as arrogant and uninformed, since symmetry is a concept at the heart of geometry, both ancient and modern, and Feng shui (not the modern, new-agey version) is a concept that has been used in the chinese culture for at least 3000 years as a set of guidelines for how to lay out cities, towns, and buildings, involving a fair bit of geometrical reasoning.
If you are interested, some of the most interesting "geometrical" art ever developed is in primarily muslim countries. Since it was forbidden to depict human images (including that of Muhammad the prophet) in early Islamic times (afriad of falling into the whole worshipping graven images thing), most of their art derived from geometrical patterns and symmetries. The artists were forced to develop all their art without recourse to that most common of things in art, the human form. The results are astonishing - Turkey and Morocco have some of the most incredible mosaics and tilework art in the world. You would probably enjoy looking at some of it.
"I'm not worried about it -- if there truly was an industry-affecting shortage, oil wouldn't be US$66, it would be US$1000."
Or perhaps they all share the rather optimistic beliefs that you have regarding extraction technologies and about oil generation, and consequently are undervaluing their assets. Proper pricing can only come about when information about supply is both accurate and widespread, as you well know.
If the temperature is right, this implies this kind of event is happening constantly, on a massive scale, somewhere deep in our sun, and every other second generation star with a supply of heavy elements in it; seeing as our sun is still around, I don't think we have much to worry about from ravenous mini-black holes... Or do heavy elements (i.e. higher than Fe) get fissioned into smaller elements so quickly that none of them exist in quantity inside of stars?
Re:For the rocket scientists out there....
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Pluto Probe Delayed
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· Score: 1
Thanks for the back-of-the-envelope calculation... I suspected it was something like that. I presume the reason it is "easier" to orbit a probe around, say, Jupiter, is that a) It doesn't require quite the same velocity to get there in a reasonable amount of time, and b) Jupiter's stronger gravitational field means an orbit can be maintained at a higher velocity, so less speed needs to be burned off....
Is there some fairly simple metric of "efficiency" of a rocket? I know with jet engines we like to get maximum mass flow per unit energy (since the most efficient way of transforming energy to momentum is maximum mass flow with minimum velocity change), but since the rocket carries it's own mass flow, so to speak, the options are far more limited... Any sources you can recommend for a curious amateur?
For the rocket scientists out there....
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Pluto Probe Delayed
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· Score: 3, Interesting
...If I read the mission description correctly, this probe is scheduled to be in the vicinity of Pluto and Charon only for a day - in other words, it is doing a fly-by. Why not try something more ambitious, like enter orbit around Pluto? I understand the heat/technical problems with actually landing on Pluto or Charon; but is the energy requirement to enter orbit rather than just flyby that large? I know the probe is getting a gravitational boost from Jupiter, so it shaves a few years off of the flight time, but if it didn't get that boost, wouldn't it arrive in Pluto's vicinity with less energy and thus be easier to put into orbit? Or is the extended time in space that much more likely to lead to failure? I don't have to explain the obvious payoff in terms of scientific benefits of a long-term orbit versus a one day fly-by...
As you say, perpendicular forces do not affect each other. This mean the force of the rocket being lofted vertically will not affect the strong LATERAL force being exerted by the wind, including when the rocket is right by the launching gantry for the first few seconds. When the rocket is resting on the launch pad, the friction of the base on the pad exerts the requisite lateral forces necessary to keep it from sliding sideways - but the moment it lifts off, that goes away. Being pushed into the gantry at liftoff (when it has virtually no maneuver capabilities to prevent it) would be disastrous for obvious reasons. Yes, there is a certain amount of clearance between the two... just enough to tolerate winds up to the stated maximum.
Slashdot Mirror
That USED to be the beauty of the place, a long time ago. Fry's has taken what little electronic hobbist store business there is, and the rest is all by catalog, sadly. I don't think there are enough electronic hobbists in the U.S. today to support a nationwide chain of stores catering to that. Someone or ones in Radio Shack management came to that conclusion back in the 80's after the PC market consolidated (remember the Trash-80?), and the chain has tried to remake itself into a mass market cheap electronic gadget distributor ala Best-Buy and P.C. Richard, replacing employees who knew how to fix and build things with the "You want fries with that?" crowd. It has to date failed rather miserably at this task, which relys on massive stores with room for both inventory and selection of "consumer electronics" and doesn't give a rat's ass about hobbists any more.
At least, that's my perception of them here in New England and in my frequent visits to Texas...
"Think of the press as a great keyboard on which the government can play. "
They didn't say it, but they sure act that way.
It's nice to see someone else who gets the idea that science is FUN because we really don't know until we look! While it's great we've figured out quite a bunch, the interesting, fun, fascinating part is the stuff we haven't tested quite yet - that's where the excitement is, and that we can't know a priori what is a good theory and what is not until we do.
Well, science has also postulated the existence of the anti-electron (Dirac), electromagnetic waves (Hertz), and missing elements like Eka-aluminum aka Gallium (Mendeleev), all without actual "evidence" for their existence at the time the theories were proposed. Then, once the theories were put out there, people tried experiments to see if the theories' predicitions were true. If they were, great theory! If not? Oh well, that's how it goes. Aether was one of the "that's how it goes" ones, but it wasn't invented because the theories were "inadequate", it was invented because it explained all the evidence accumulated up to that point in a theoretical framework pretty well. One of it's predictions (that the speed of electromagnetic waves would vary depending on the motion of the earth through the aether) turned out to be wrong, (as demonstrated my Michelson and Morley), but until the experiment was done, nobody could have known that! And the implications of that were so shocking and anti-intutitive, that it took an Einstein to boldly speculate that there was no aethereal medium for light waves, but instead our conceptions of time and space were off. There was no actual evidence for mass increases with motion nor length contraction either when Einstein came up with Special Relativity - that came later, after his theory suggested people look for those phenomenia. If experimentalists DIDN'T FIND THEM WHEN THEY LOOKED, then relativity too would have gone into the dustbin. But you can't know that ahead of time.
That's how science works, if it just "explains" (condenses into a few formulae/models) that which has already been observed, it's a bit useless. It HAS to make hypotheses beyond the actual evidence if it is to have any value as a predictive tool - this is why faslfyability is so important. If you can't falsify it, you haven't predicted anything, and therefore it's kinda useless.
BTW, I tend to agree with you about dark matter - it does seem to be awfully omnipresent yet remarkably undetectable. But then again, so is the neutrino! That's the exciting part, we don't know yet. It could still go either way. Wouldn't it be boring otherwise?
That's the amusing part; as far as I understand it, no. The whole dark matter thing is rather touchy because of this - it describes something that only interacts via gravity. Remember that our sense of "interaction" (touching, burning, etc.) are all based on electromagnetic forces, so this dark matter could be passing through us right now and we would not notice it (much like neutrinos, which pass through us by the billions per second). Of course, at least neutrinos have the decency to OCCASIONALLY interact with normal matter, or we would have never detected them at all, only hypothesized their existence to make various important laws (like conservation of momentum and particle spin) work.
It's an intriguing idea, though. The reason ordinary matter piles up into big chunks like planets and stars is not just gravity, but the OTHER forces that keep it "stuck" together. Without that, matter would just be cruising along, looping around due to gravity, perhaps even "colliding", but without a method of storing or dissipating their kinetic energy (chemical bonds, which allow "heat" or vibrational motion energy), they will never stop moving or agglomerate or anything like that, making them more like a perfect gas without a container but with gravity. Neat stuff.
I just hope there is some way of directly detecting this dark matter (have it interact with something in a particle chamber in such a way that dark matter is required to explain the observation), or at least have it fall naturally out of the Standard Model or a successor, or it is going to have an aethereal feel (pun intended) about it.
Actually, Godel did no such thing - he demonstrated that in any formal system of logic sufficiently complex to encapsulate basic arithmetic, there will be unprovable statements which are nonetheless true. Note that the reason we can say these unprovable statements are true is because that if they were false, there would exist a provable counterexample to the statement (i.e. an example of the falseness), and thus the statement would not be unprovable - but this knowledge comes from outside the logical system. In other words, he demonstrated that there will be true statements in a logical system that can never be proven within that system to be true; a hypothetical example might be Goldbach's conjecture, that any even number > 4 is the sum of two (not necessarily distinct) primes. If this was, in fact, true, but was somehow "unprovable", we would be left in the uncomfortable position of seeing billions of examples where it is true, not a single example where it was false, but of course there would always be an infinity of cases we didn't check yet. This is, in fact, the present state of our knowledge - and thus why I used it as an example. Of course, some clever egg might stumble upon a proof of Goldbach's conjecture tomorrow - people used to use Fermat's Last Theorem as a potential example of something that might be true but unprovable, until Wiles proved it. This is the problem, that we have no way of knowing what is unprovable in mathematics, because if we did have such a way of "knowing" (i.e. proving that a proposition is unprovable) for a specific proposition, we would have just proven it true, and thus it would not be unprovable! So we will never know what is not provable - we will only suspect that one of Godel's unprovable but true phantasms is staring us in the face.
My point (longwindedly) is that this has little or nothing to do with the physical, mathematically modeled, problems at hand here; if you want a better idea of the type of barrier we are facing in this case, you would be better served by complexity and information theory; look up Shannon and Chaitin for more info - that is the type of problem involved in turbulence simulation, not logical issues of provability and incompleteness.
In a sense, you are right, but It's worse than that. In all the other cases, we have models of the phenomenon that (in many cases) are partially derived from second principles (the gas laws, Navier-Stokes equations, etc.). Unfortunately, turbulence in a fluid flow is apparently unamenable to modeling with those laws - they pretend that a fluid is grainless and infinitely divisible (no atoms/molecules), and wrap up the more complex intermolecular forces under the viscosity term. Turbulence (apparently) is fundamentally related to the way individual molecules interact, and we simply don't have models that can handle this in the quantites ( > 10^10 molecules being simulated) required. In other words, we can not predict turbulence in a fluid flow from first principles (intermolecular forces - i.e. quantum interactions); we have an empirical understanding of them only.
As for the turbulence in airplanes, there is some limited prediction done, but it is based on some common sense ideas, such as when the wind direction/speed changes rapidly with a change in either vertical or lateral position, there will tend to be turbulence (such as going from the core of a jet stream to the outside of one).
...although it's almost a year old. Nonetheless, it goes into the details a lot more.
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http://www.usatoday.com/tech/news/robotics/2005-0
I remember it because I thought it was so bizzare, and because I had no idea there was a black market in young boys who were good camel jockeys. Weird.
...when directly interested parties are involved. This is the problem with Wikipedia. In a jury trial, great pains are taken to assure that the juries consist only of people without any personal interest or attachment to the outcome; this seems to be an inherently time-consuming and expensive process.
/., Wiki, and all the other attempts at what ruleset allows a productive, participatory, democratic system that results in the best knowledge interesting - nobody has hit upon the right answer yet, but we are learning and getting better by watching what does and doesn't work. If only we could apply this to something like voting! Unfortunately, WAY too many overinterested parties are already assuring that almost any change to the voting system that gets implemented will make it worse from the voter's point of view.
Up until recently, Wikipedia has relied on the fact that it was relatively unknown outside the geek population, and so the odds were that highly agendized individuals were not drawn to it as a priority. This, unfortunately, has changed with Wikipedia's popularity.
This is what makes
One: As to your resigning, cheers. It's one thing to bitch about a problem, it's quite another to put one's job on the line (or in your case, take it off line). There appear to be many /.ers who casually say how the engineers in question should have walked off the job, not allowed the launch, etc., when in fact, it is never quite so easy. I hope you have the good fortune to soon work for a firm that appreciates and respects your integrity, and I hope you sleep easier at night.
/ docs/rogers-commission/Appendix-F.txt
Two: As for the specs, the boosters were OUT of the original spec, which said that there should be NO burn-off of the O-rings, as they were supposedly completely sealed from the combustion chamber by a ring of putty. Unfortunately, for reasons unknown, the putty would develop holes which would allow hot gas to escape and start to erode away the O-rings, as revealed by post flight inspections. Did they track down the cause? Not really, but then they came up with a nice empirically derived curve of the O-ring burn depth that was fitted to the data points, and concluded since the average burn depth was 1/3 of the amount needed to cause O-ring failure, they had a safety factor of 3. I kid you not. Here is the link, on NASA's web site, of the appendix to the Rodgers report by Richard Feynman, who gives the most lucid explanation of what safety oriented engineering should be, and how NASA disregarded it.
http://science.ksc.nasa.gov/shuttle/missions/51-l
It seems the main thing that distinguishes Jobs, according to the slideshow, is that he knows his companies' products to the point where he is unafraid to get involved with them at any level from suppliers of suppliers to design to marketing. In other words, he thoroughly knows his business.
A CEO who thoroughly knows his business redefines what a CEO is? This merely highlights the disease that has infected much of corporate America, namely that you don't have to know shit about your business or product, all you have to know is how to manage people, whatever that means.
This is about as effective as the idea that you don't have to know jack about math, or physics, or history in order to teach them; all you have to be is a good teacher, whatever the hell that means.
News Flash: Intelligence, experience, knowledge and motivation are far more important in running a company than an MBA. Steve Jobs illustrates this. News at 11.
...that is a rather interesting demo. Try it with "9-11" as well.
I think to some extent Apple and Microsoft are reflections of Jobs and Gates.
Microsoft has done much in the computer world, but I don't think many would accuse them of being innovative, and I think that is a reflection of Gates - he sees practical opportunities to sell product, or take an idea and make it profitable. He just never seemed that creative.
Perhaps he is bored now. Love them or hate them, Microsoft is the dominant player in the computer industry by far. That's a boring place to be, after a while. Microsoft is unfocused today, much like Bill is. A mid-life crisis, you might say. And Gates is trying to use the insane amounts of money he has aquired for something other than aquiring more insane amounts of money or implementing more of other people's ideas. He wants to get meaning in his life, and helping others gives a sense of meaning that he probably doesn't get from computers any more.
Jobs, on the other hand, still loves computers, and loves Apple. After his near death experience with pancreatic cancer, I think he gets a charge out of leading the pack with new ideas and trying new things. Plus, Apple has a lot further up to go than Microsoft does.
Rich people usually don't get generous until they start Wondering About the Meaning of It All. Bill's wondering, and Jobs has already figured it out. In Jobs' case, it involves Apple rather than other people.
Pop psyc rant over.
...to come up with justifications for a course of action that would vastly enrich you. All you have to mutter are the magic words, "maximize shareholder profit". IBM made the similar arguments working for Nazi Germany, and pointed out they made plenty of contributions to the Allies as well. Scientists throughout both world wars on all sides justified their work on war weaponry (poison gas, atomic weapons, incendiary bombs, etc.) in terms of, "if it shortens the war, less people will die, so this is good."
Of course, these justifications usually have a nugget of truth in them, or they wouldn't salve the consciences of the people coming up with them.
I don't know if Google is doing evil, but they sure aren't doing good here.
I generally don't respond to AC's, but I'll make an exception in your case because you completely missed most of the subtleties of the situation. The calculation was not, "Wow, look, there is a 0.92375% chance of the shuttle going "Boom!"; it was more like an order of magnitude estimate based on guesswork and engineering experience, which is much harder to justify. Safety engineering, piloting, and other "veto for safety" situations based on operational experience rather than a fill-in-the-blanks-out-spits-probability situations, are inherently difficult ones. This is because the odds are, 99% of the time, things will be okay, and if you are the "bad guy" and hold things up, and they work out fine for your replacement (as they will, 99% of the time), in a manager's mind (unless he is really good), YOU are the problem, not the situation you said was unsafe. It's the 100th time that catches you. Or the 101st. Or the 1000th. That's the problem - safety is not a device or a simple calculation, and it is not proven to have existed because of a successful outcome - it is an attitude towards limits and the unexpected, and what is a reasonable risk vs. the return and what is not.
As for your comment regarding war and acceptable losses, that's fine. But the point was that the shuttle could have been MUCH safer (by three orders of magnitude) if the engineers' advice was sacrosanct, with little loss of productivity. Is getting a 30% increase in flights per year worth an increase of x1000 times risk of hull loss?
I'm glad some other /.ers know about Feynman's crucial role in the Challenger investigation. Feynman also goes into great depth about his feelings writing the report, and other insights about the whole process in his book, "What do you care what other people think? More adventures of a curious character" - highly recommended. Feynman was substiantially more critical of NASA than the other people writing the report, and almost decided to have his name removed until he was allowed to put his conclusions, unedited, into an addendum to the offical report.
7 /qid=1138363884/ref=sr_1_7/103-7798844-8308625?_en coding=UTF8
You know that famous line of his, "Nature cannot be fooled?" - it's from the coda to that report.
http://www.amazon.com/gp/product/0393320928/sr=1-
Thank you for the kind comment - it is nice to know that I am not the only one for whom a library at home was an essential part of growing up. I too have about 60 boxes of books waiting to be put into my new apartment when I am done moving! I didn't realize how much of an "instinct" my book collection habits were until I was packing to move and realized that my books took up more boxes than all the rest of my possessions put together. That, and a mover remarked about my "book hobby" - I never thought of it as a hobby before...
I recently had to go through my father's old library (my father died many years ago, and my mother just sold the family house and "downsized" into a nice, cozy apartment, with little room for "extra" books), and of course I decided to keep most of his old books, even though I may never read them. Many of them I was very familiar with; books on sailing (he was a sailor for many years), history (WWII specifically - he immigrated to the US in '39 as a direct result of Hitler), and many art books. But then there were all these quirky fiction books by (I forget the exact name) Gabriel Marquez? Apparently he was known as a master of a "fantasy" fiction style popular in South America; I had never even heard of him until I came upon these old books. One day I'm going to read them, and a part of my father's world I never knew about will be part of mine as well.
Perhaps that's the appeal, that a book is a small world, and there is something to be treasured about them even if any particular one is not your cup of tea. But that makes an awful lot of small worlds you can have in one small room.
My complements to you as well. I hope you have kids someday - I think the world needs more kids lucky enough to have a wise parent or two.
You would be surprised. Remember, your typical American ruler is broken into binary fractions of an inch (1/2, 1/4, 1/8, and usually 1/16 is the smallest). In order to measure something to less than a whole inch, you have to be familiar with those fractions, how they convert, how to count them, and so forth. I can personally attest to the fact that many kids have no idea what exactly all the submarkings below an inch mean. They have a hard time memorizing the powers of two, which you probably take for granted, so they have to count how many marks there are to know the denominator of the fraction, remember that, then recount how many marks they move over to the edge of the thing they are measuring.
Sounds complicated when you describe it like this, doesn't it? You probably learned it at such a young age that you don't remember a time when it didn't make sense or you had to think about it.
Another sign of this is a somewhat new breakdown in the clothing and fashion industry. It used to be that there were just Fashion Designers, who controlled the making of a garment from mental conception all the way to the fractions of an inch, stitches per inch, seam width, etc., that were given to the manufacturers of garments. Nowadays, there are Fashion Designers, and Tech Designers. The Fashion Designer has the "creative" part, and the Tech designer is the one who translates that into inches, stitches, fabrics and so forth! In other words, the ability to handle numbers, fractions, and measurements is now considered difficult enough to render a new job position. I know this because my mother has been in the garmento industry for 40+ years. She is now a tech designer, because nobody wants to do that icky math stuff; all the FIT graduates want to be "creative" designers. Not suprisingly, tech designers typically get paid about 2 to 3 times more than fashion designers.
When I was younger, I was raised in a household with a library. It wasn't a very big house, but the library room was important; this is where my dad would sit and read, and I could do so as well. It never had to be said directly to me (at least, not that I remember), I just understood that the books were important, they were there to be read, and that was an important way to learn about the world. The books were knowledge, and that knowledge was respected. Whenever we visited someone else's house, I would always look at their library, because my father said you can learn a lot about a person by seeing what kind of books they read. A house without books was not a home to me.
Now, I visit people living in McMansions in various parts of the US, and I find many of them have no library, even though there is far more room for one if they so chose. Not surprisingly, their kids have little interest in reading, because their parents don't read, yet are "successful" - i.e. they have the McMansion and stuff to fill it. What conclusion do you think most kids today will come to?
"Success" and education APPEAR more uncoupled in today's world than they used to be - and that is awfully hard for even the best teachers to overcome. The people who are drawn to knowledge for its own beauty have always been a very small minority; for the rest, education is interesting to the extent it is rewarding. If the rewards appear less, the education is less interesting and devolves into seeking the form (degrees) rather than the substance.
Btw, I used to tutor kids in their homes for many years, so I have some experience/bias when it comes to how kids are educated....
I'm not quite sure what you mean by calculus when you say you "[found] shortcuts for algebraic equations in the 7th grade." - I presume you mean shortcuts for solving them. Calculus has nothing to do with solving ordinary equations; it devises new functions, new operations you can do on functions, and thus new kinds of equations that were unexpressible without it (ODE's, PDE's, fxns defined by integrals, etc.).
When you say you "aggressive"ly tried to find the most effecient geometry, and that you prefer geometrical balance over "Feng shui, symmetrical balance and all that garbage", it comes across as arrogant and uninformed, since symmetry is a concept at the heart of geometry, both ancient and modern, and Feng shui (not the modern, new-agey version) is a concept that has been used in the chinese culture for at least 3000 years as a set of guidelines for how to lay out cities, towns, and buildings, involving a fair bit of geometrical reasoning.
If you are interested, some of the most interesting "geometrical" art ever developed is in primarily muslim countries. Since it was forbidden to depict human images (including that of Muhammad the prophet) in early Islamic times (afriad of falling into the whole worshipping graven images thing), most of their art derived from geometrical patterns and symmetries. The artists were forced to develop all their art without recourse to that most common of things in art, the human form. The results are astonishing - Turkey and Morocco have some of the most incredible mosaics and tilework art in the world. You would probably enjoy looking at some of it.
"I'm not worried about it -- if there truly was an industry-affecting shortage, oil wouldn't be US$66, it would be US$1000."
Or perhaps they all share the rather optimistic beliefs that you have regarding extraction technologies and about oil generation, and consequently are undervaluing their assets. Proper pricing can only come about when information about supply is both accurate and widespread, as you well know.
If the temperature is right, this implies this kind of event is happening constantly, on a massive scale, somewhere deep in our sun, and every other second generation star with a supply of heavy elements in it; seeing as our sun is still around, I don't think we have much to worry about from ravenous mini-black holes... Or do heavy elements (i.e. higher than Fe) get fissioned into smaller elements so quickly that none of them exist in quantity inside of stars?
Thanks for the back-of-the-envelope calculation... I suspected it was something like that. I presume the reason it is "easier" to orbit a probe around, say, Jupiter, is that a) It doesn't require quite the same velocity to get there in a reasonable amount of time, and b) Jupiter's stronger gravitational field means an orbit can be maintained at a higher velocity, so less speed needs to be burned off....
Is there some fairly simple metric of "efficiency" of a rocket? I know with jet engines we like to get maximum mass flow per unit energy (since the most efficient way of transforming energy to momentum is maximum mass flow with minimum velocity change), but since the rocket carries it's own mass flow, so to speak, the options are far more limited... Any sources you can recommend for a curious amateur?
...If I read the mission description correctly, this probe is scheduled to be in the vicinity of Pluto and Charon only for a day - in other words, it is doing a fly-by. Why not try something more ambitious, like enter orbit around Pluto? I understand the heat/technical problems with actually landing on Pluto or Charon; but is the energy requirement to enter orbit rather than just flyby that large? I know the probe is getting a gravitational boost from Jupiter, so it shaves a few years off of the flight time, but if it didn't get that boost, wouldn't it arrive in Pluto's vicinity with less energy and thus be easier to put into orbit? Or is the extended time in space that much more likely to lead to failure? I don't have to explain the obvious payoff in terms of scientific benefits of a long-term orbit versus a one day fly-by...
As you say, perpendicular forces do not affect each other. This mean the force of the rocket being lofted vertically will not affect the strong LATERAL force being exerted by the wind, including when the rocket is right by the launching gantry for the first few seconds. When the rocket is resting on the launch pad, the friction of the base on the pad exerts the requisite lateral forces necessary to keep it from sliding sideways - but the moment it lifts off, that goes away. Being pushed into the gantry at liftoff (when it has virtually no maneuver capabilities to prevent it) would be disastrous for obvious reasons. Yes, there is a certain amount of clearance between the two... just enough to tolerate winds up to the stated maximum.
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