Because you might be using web applications that make use of ActiveX controls...
Same here. Well, not for a company (er, I'm just a student?), but there's one website that doesn't load properly in my web browser, and only found out why when I was visiting it at my sister's place.
Normally, I wouldn't care and just move on (why bother with those non-standard compliant ****'s?), but it's a sort of online-community thing both my sister and my cousins are on, so I just go to that website when I'm at a school computing center. Hopefully, when IE goes out of style, so will such non-standard compliant ****, and they will code their page properly.
Apparently, you've never seen an actual papyrus (where we get most of our classical literature) before.
It's difficult enough for a trained professional (papyrologist) to decypher that, let alone for a machine. So, most of the stuffs we read has to be transcribed by such a professional, and then it's a trivial effort to digitize it properly (i.e. no OCR stuff).
The problem most people have with classical studies is that they don't realize this: "All translations are bad." If you really want to study something in Greek or Latin seriously, you have to learn the language--there is so much lost in translation (regardless of the ability of the translator), and the only way to realize how much is really lost is by your being able to read the "original" (well, as original as possible anyway...since the claim I hear is that we never have the original manuscript) text yourself.
Let's not trade quality for accessibility.
PS. Oh, even word-to-word translation is not proper. For one, "xenos" (in standard Latin transliteration) has no single-word translation in English that has all of its denotations and connotations, not to mention that some words (er... mostly particles) are simply "untranslatable" (i.e. those are "sign posts" that denote certain "senses..." Try explaining that to a Classical Civ major who doesn't understand a thing in Greek).
In fact, I've two sets of handwriting - all my equations and math stuff is written straight up, and the rest of the stuff goes cursive. Makes it a lot easier for me (and those reading it) to decipher what I've written.
I have multiple handwriting styles (er, normal, cursive, and block-lettering ("small caps")), too, but I haven't tried exploiting that distinction.
Now, if I can practice writing a good cursive on blackboards, I can use that technique in my classes....
Reading cursive takes much longer, not only taking longer but it turns reading into a guessing game. Is that an a or an e?
I for one enjoy the "guessing game." I find it rewarding to be able to read something without having to recognize everything letter-by-letter (the context should tell you what letter it had to be, unless it's a proper name).
Apparently, you haven't done one of those exercises they give in, er, high school publication classes.... Well, it has to do with how one shouldn't write everything in capitals because most people do not read (i.e. understand) a writing/sentence by recognizing everything letter-by-letter. People learn to recognize blocks of letter, based on relative size/positions (and using that it is possible to guess what the sentence/word was even if someone were to color all letter-blocks black... of course, this doesn't work with Courier).
BTW, I guess this does lead to some sloppiness--I use cursive when I'm not sure how to spell a word exactly, because I know that most people able to read cursive do not rely on getting the exact spelling.;)
Does anybody else who is under 30 still write in cursive, other than when they made you do it in elementary school?
Ask me in 10 years and I'll say, "Well, I still write in cursive, but I'm over 30...."
Cursive have various uses, with proper training. Among various uses:
i) Letter/Card-writing. A well-written cursive looks so much better than awkward handwriting that breaks between every letter (instead of blocking off words nicely). And, a hand-written letter/card is more personal than a typed one.
ii) Note taking. With training, writing in cursive is definitely faster than any other writing. Sure, dotting the i's and crossing the t's might take some time... but, if you are really in hurry, you can forget about those and go back to it later.
iii) Note-to-self's. I have a few handwriting styles. Although I normally count my cursive handwriting as one style, there's a distinction between the handwriting I use on things I intend for other people to read and the handwriting I use for myself. The upside: the handwriting for myself is virtually incomprehensible to anyone but someone who's seen it for at least a year and knows the vocabularies I use frequently (I live by the principle, "If you can recognize the first four letters, you should know which word it is."). So, if it's something personal and it gets lost, I don't have to worry about other people reading it.:)
I'm a student, and I'd LOVE to be able to quickly type equations. For note-taking alone, it would be a huge boon.
Ah, now, but would you want to be deriving the equations on computer?
I couldn't ever derive anything on computer. When I have to come up with an equation for my lab report, I first write it on a piece of paper, even if I have to retype it (using equation editor) on computer.
One feature that equation-typing seems to lack (disclaimer: I haven't used TeX) is cancellation notation... Sure, I can just delete the corresponding quantities, but, what if I made a mistake and want to look through the steps again? I haven't seen a nontrivial way of denoting that...
...no amount of "education" is really going to block them or persuade them from accessing it.
So, are you saying that whole "education" thing is ill-conceived and doomed to begin with?
It is the whole point of education program to dissuade them from accessing illegal porns (well, any porn is illegal for kids, if it's like in U.S.). If you are saying that this goal is unreacheable from the start, well, I would like to see some supporting arguments.
BTW, I would rather argue that no amount of "blocking" is really going to stop them or persuade them from accessing it [illegal porns], if they really wanted to. Every firewall/security has a weakness, and for those who really wanted to get it, it's almost trivial effort to find a way to get around it. The solution is in curbing the demand, not the supply.
While storage is definitely a big issue that has to be addressed, that's not the first problem. Question is, where do we hydrogen to get started?
"From water (i.e. H2O)" someone might say, but H2O has less energy than H2. So, where do we get that energy to make hydrogen out of water? So far, the only way we have perhaps to mass-produce hydrogen is by electrolysis--using electricity, majority of which comes from fossil fuels.
So, as the situation is now, using hydrogen fuel isn't any more environment-friendly than burning coal to run your car.
Of course, there's the whole alternative energy view, like using photovoltaic cells or wind to generate electricity, but I'm not sure if they are any more cost effective, considering the installation cost (we don't have an infrastructure big enough to support mass-consumption), maintainance, and reliability (or lack thereof).
From the article:
The newly-developed technology uses a water-based solution of sodium borohydride, made from sodium borate, to produce hydrogen gas.
The downside is that there are only about 300 million tons of sodium borate worldwide, located mostly in Tibet, and that annual global production of sodium borohydride stands at 10,000 tons, it added.
So, other than the fact that it produces less pollution (I would hesitate to say less "green gas", though since vapor is a green gas) it has no advantage over gasoline powered scooter.
In fact, have we yet seen any viable hydrogen-powered vehicle? I thought most models/prototypes we have so far were less energy efficient than gasoline powered cars (even with infrastructure to provide hydrogen nation-,world-wide, we have to have a way of generating them, and electrolysis is simply not the most efficient way (and certainly less so than internal combustion) way to get hydrogen).
I think you got some things, er, mixed up. Gravity is a law. Why do you think they call it, "The Law of Universal Gravitation"?
In context of physics, laws are experimental findings that cannot be explained or derived from other more fundamental equations. Examples are: Coulomb Force Law (Gauss's law is an...almost equivalent law--considered to be more fundamental in electromagnetism); Ampere's law; Biot-Savart Law; Lorentz-Force law (heh... mostly EM examples, since that's what I'm studying now).
Of course, names are sometimes just plain deceptive. A non-example: Ohm's law--which is not a fundamental law but something that can be derived from other force laws and a few more assumptions about the property of the material.
Anyway. A good example of theory is, say, theory of special relativity. The whole theory starts out with two postulates, i) fundamental laws of physics are the same in all inertial frames, and ii) speed of light in vacuum is a constant.
Egh. But what's the point of arguing on semantics. The public may call different things whatever they want, and we physicists will go by our own definitions (public be damned....).
Besides, I don't think the so-called "theory of evolution" really measures up to the standards and definitions used in physics: it may have some quasi-postulates and principles (such as the survival of the fittest), but what quantitative predictions has it made that can be verified experimentally?
Er, excuse me for butting in, but how can this be mercantilism?
From Wikipedia: Mercantilism is the economic theory that a nation's prosperity depended upon its supply of gold and silver, that the total volume of trade is unchangeable.
And naturally, from there comes the whole family of crazy ideas about tariffs and "protecting the domestic industry." But, in this case, I don't see anything related to international trade (the only thing vaguely "international" seems to be, er, something about USA forcing other countries to have similar patent laws...)
So, how is this mercantilism, or were you just using a buzz word without knowing what it meant?
it might be a bit easier to read if the images were thrown into a pdf...
IDK, but I actually find PDF files that are built from JPEG files more detestable. I mean, those files are huge or pixelated and my antiquated computer (not quite antiquated as the ones in the book, though : ) has to struggle to read the whole file (a few megabytes to 20 megabytes, depending on number of pages and how pixelated the pages are) just so that I can read one page.
It would have been very nice if they could put up a properly prepared PDF file, say, exported from the page-setting application they used to make this book...who am I kidding?
Anyway, IMHO, separate JPEG images are easier to read (at least for the computer) and in this case, how would you be able to do a page-by-page comparison between the two editions in PDF?
As is the simple matter of bothering to read about what any old internet site wants to install on your computer (or just any adware in general, whether installed from a website or via a "free" software).
Imagine a scenario where someone owns an, er, expensive car, that should be filled with only highest-octane gas available. If that someone, when filling his tank, doesn't read the labels and puts whatever petroleum product (diesel, basic unleaded, natural gas...) in his car, is he dumb or not?
Most computer users--i.e. most of my friends, who, on the computer user spectrum, are on the brighter side than the national average--are in this way. (And, thus incorrigibly dumb.)
BTW, I wouldn't call "clicking on an icon labeled Internet" "stearing." It's more like "putting key in the key hole." And, now, when you go to a site like Google, then, that's "turning the key once," and when you enter search command, that's now finally "starting the car."
Such advanced skills in driving as steering should be likened to, well, such skills in using computer as steering away from sucky programs like Internet Explorer.
One of the major problems with these designs are the lasers would have to be prohibitively large to prevent the beams diverging at great distances.
Not to mention very massive (compared to the craft), so that the laser itself doesn't get accelerated to maybe 3,000 km/sec in the process due to conservation of momentum.
Are these real "plans" or are they just made up (er, on the spot)? Lasers, maybe, but microwave transmitters? Microwave has frequency (and thus, momentum per photon) much lower than visible light (in fact, it's right between radio frequency and infrared), and, although I don't know too much details about microwave, simple knowledge (which, I fancy, I possess) of basic physics should say that something with that long a wavelength cannot be focused very well.
In any case, energy conservation (in case of elastic collisions, and for inelastic collisions, well, it's even worse) demands that as much energy as would be needed for a conventional rocket be used to propel those rockets--so, how is that any more effective than what we have now? At least for solar sail, the idea is to harness the energy of the sun, much of which goes wasted, but unless the laser system, on top of being prohibitively large and cost-ineffectively massive, utilizes photovoltaic cells to "continuously recharge themselves" (er... in Data's words in 'Insurrection'), I don't see what the benefit of even considering those plans.
So far, the only human-powered (i.e. non-solar-sail) next generation space rocket idea I heard that makes sense is the one that uses, er, fission explosion at the rear to propel itself.
I don't know much about physics, but could something like this be used as a heat shield of some kind? Like, where the shield is basically considered turned off when it is in the liquid state. Then when it hits a certain overload temperature, it turns to a solid and thus blocks (some of) the heat exchange?
That would probably depend on the property of the solid that forms when the solution is heated (is it a good insulator? what are its structural properties?), but I can think of one related application: temperature-controlled switch.
The solution is transparent to visible light, whereas the solid that forms is not. Since this process depends on the temperature and is reversible, it's very simple to design a circuit (using a LED and phototransistor or some sort of photo-detector) that works as temperature-dependent switch. From what the article says,
The temperature at which it becomes a solid falls as the concentration of CD increases.
it should be possible to tweak the turn-on temperature to a degree.
But then, this is not anything new--as far as dependence on temperature goes, there are many other materials that are probably more reliable (the only thing novel about this would be that its dependence is backward.)
Back to the topic, yeah, it can probably be used as heat shield in a limited capacity: i.e. if it turns out that the liquid is transparent to infrared radiation while the solid isn't, this can be used as natural temperature-controlled infrared radiation shield (but of course, it will still be subject to heating due to other methods, like...conduction via the solid itself, unless the resulting solid turns out to be similar to styroform).
Pumping the energy up into this range gets to the point where you can't ignore the nuclear motion, so you get into areas where the usual equations don't work.
I see... come to think of it, energy corresponding to 70+ eV is almost half-an-order-of-magnitude larger than the ionization energy of hydrogen. But, in case of H_2, is it really that much of a many-body problem? (I mean, I do understand that it is a four-body problem, but that's not nearly as complicated as solar system...)
Well, on the second thought, I don't remember any treatment of covalent bonding in my QM courses. I probably should ask my GSI when I have a chance.
Not to play down the importance of experiments in physics (gosh, I'm a physicist. I should know), but how is this experiment important at all?
Hydrogen atom (thus, I think, molecules...) is very well-studied theoretically. Gosh, they don't just stop at calculating different energy levels due to Coulomb force. At third-year level of undergraduate physics classes, they already calculate fine-structure splitting, hyperfine splitting, and even Zeeman splitting, in presense of a magnetic field. At that level, the theory is getting so accurate, and the energy level splitting becomes so small that if you want to fit a photon of right energy between the energy levels, you have to go down to the frequency of radio waves. It's not like we need experimental results (as in the case of more complicated atoms) because you can't solve (or approximate very closely) for the energy levels of the atom.
Since deuterium is practically identical to hydrogen, unless you want to study the nucleus itself (I mean... it's two fermions, so something must be different, even though they are not identical particles), what's the point of publishing results of an experiment like this? This sounds not much more sophisticated (or important) than the experiments done in advanced physics lab (er... optical pumping, Rutherford scattering, NMR, etc. etc.).
It would be a totally different matter if they found something that contradicted predictions of an established theory...but, did they?
75 eV isn't nearly enough to split the nucleus apart anyways.
But that's not what they want to do. As someone must have (I mean, am I the only person who remembers high school chemistry?) mentioned it already, they are splitting an H_2 molecule into two atoms of H. (At the end, H- ions, presumably.) The fact that they are using deuterium doesn't change anything except that the H- ion is twice as heavy and that the target area (er, "cross-section," is probably the correct term).
BTW, where did you get this quote?
Deuterium has somewhat different chemical properties than hydrogen due to the different nuclear mass (classically, it's a two body problem, look up `reduced mass' if you want more details.) With a larger nucleus mass, the electrons would have a lower average kinetic energy, and by the virial theorem the average potential energy would therefore be higher (KE = - 1/2 PE) (a smaller absolute value, but it's negative, so it's higher) and therefore less tightly bound.
You should tell them to fix their entry--I know what virial theorem is, and I know how to calculate the ionization energy of hydrogen atom. Unless you want to go into fine-structure splitting, most people assume that the nucleus has infinite mass (it's more than 1000 times as heavy as electron, so the error related to the approximation is less than 1 part in 1000). The only thing that's different with deuterium is that now your error is less than 1 part in 2000, if you used the infinitely-massive-nucleus approximation.
Lock them up in their own house, cut their phone/cable? (In that case, are they sure that the withdrawal symptom is due to withdrawal from Internet or from fresh air...who am I kidding?)
Or were they just relying on the subjects' integrity and sense of honor to hold up against the overwhelming withdrawal symptoms? And did they really expect the subjects to be honest about it, if they slipped up?
IDK, but something smells fishy here. This sounds just like the M$ report that says total cost of ownership for linux is higher than M$ servers.
Or this is just a big joke and/. editors are a part of it.
Am I just some weird exception to the rule or am I doing something out of the ordinary? Is it that they're constantly on?
Not at all!:) In fact, the parts I replaced all worked, and the RAM I added were, well, added, as in there were open RAM slots where I just stuck in a couple more sticks. The only computer part that broke down was the hard drive that originally came with my computer...I probably formatted it one too many times. (And well... I probably would have kept using it, but my parents, not wanting to deal with a slightly faulty drive, threw it away.)
I just find it very irresistible when I see someone throwing away a Pentium III 450MHz motherboard and CPU when I'm running a 400MHz.:)
PS. Hmm, BTW, as far as my computing habit goes, my computer is always on, too--to the consternation of my parents...(er, bill anyone?)
The computer I'm using to write this article was bought in 1998. I've done so many upgrade (er, usually throw-out HD's, RAM, and, once, a motherboard), so I'm not quite sure what it is now... but it's one of the oldest computers I've seen around (heck, even the library has newer computers with shinier screens). But running on linux (an LFS system, so it's at the lower end of resource usage, even among linux boxes--it has barely enough for X and some other basic applications I absolutely need and use very often), it's doing O.K., and I would even say it's much faster than my roommates' 1,2-year-old laptops running Windows XP and lots of Adwares, when it comes to loading webpages and checking e-mail.
The only time I felt the need for more computing power was when I was actually building the system--so much compiling, so much time.
if someone discovered a flaw in a piece of popular software that runs on most linux machines...
And if I got a dime every time I heard an implausible hypothetical situation...
FYI, my linux box didn't run openssh (or any kind of ssh at all) until the server hosting my website (er... it's a student organization at my school) decided that it will discontinue all "insecure" telnet and ftp services.
In any case, the point is, in order to get rid of that kind of virus, all an admin has to do (at the most extreme case) is "userdel IdiotJoe -r" (and hopefully IdiotJoe didn't have any permission to write anything outside his own home directory and/tmp.)
Slashdot Mirror
Same here. Well, not for a company (er, I'm just a student?), but there's one website that doesn't load properly in my web browser, and only found out why when I was visiting it at my sister's place.
Normally, I wouldn't care and just move on (why bother with those non-standard compliant ****'s?), but it's a sort of online-community thing both my sister and my cousins are on, so I just go to that website when I'm at a school computing center. Hopefully, when IE goes out of style, so will such non-standard compliant ****, and they will code their page properly.
It's difficult enough for a trained professional (papyrologist) to decypher that, let alone for a machine. So, most of the stuffs we read has to be transcribed by such a professional, and then it's a trivial effort to digitize it properly (i.e. no OCR stuff).
The problem most people have with classical studies is that they don't realize this: "All translations are bad." If you really want to study something in Greek or Latin seriously, you have to learn the language--there is so much lost in translation (regardless of the ability of the translator), and the only way to realize how much is really lost is by your being able to read the "original" (well, as original as possible anyway...since the claim I hear is that we never have the original manuscript) text yourself.
Let's not trade quality for accessibility.
PS. Oh, even word-to-word translation is not proper. For one, "xenos" (in standard Latin transliteration) has no single-word translation in English that has all of its denotations and connotations, not to mention that some words (er... mostly particles) are simply "untranslatable" (i.e. those are "sign posts" that denote certain "senses..." Try explaining that to a Classical Civ major who doesn't understand a thing in Greek).
I have multiple handwriting styles (er, normal, cursive, and block-lettering ("small caps")), too, but I haven't tried exploiting that distinction.
Now, if I can practice writing a good cursive on blackboards, I can use that technique in my classes....
I for one enjoy the "guessing game." I find it rewarding to be able to read something without having to recognize everything letter-by-letter (the context should tell you what letter it had to be, unless it's a proper name).
Apparently, you haven't done one of those exercises they give in, er, high school publication classes.... Well, it has to do with how one shouldn't write everything in capitals because most people do not read (i.e. understand) a writing/sentence by recognizing everything letter-by-letter. People learn to recognize blocks of letter, based on relative size/positions (and using that it is possible to guess what the sentence/word was even if someone were to color all letter-blocks black... of course, this doesn't work with Courier).
BTW, I guess this does lead to some sloppiness--I use cursive when I'm not sure how to spell a word exactly, because I know that most people able to read cursive do not rely on getting the exact spelling. ;)
Ask me in 10 years and I'll say, "Well, I still write in cursive, but I'm over 30...."
Cursive have various uses, with proper training. Among various uses:
i) Letter/Card-writing. A well-written cursive looks so much better than awkward handwriting that breaks between every letter (instead of blocking off words nicely). And, a hand-written letter/card is more personal than a typed one.
ii) Note taking. With training, writing in cursive is definitely faster than any other writing. Sure, dotting the i's and crossing the t's might take some time... but, if you are really in hurry, you can forget about those and go back to it later.
iii) Note-to-self's. I have a few handwriting styles. Although I normally count my cursive handwriting as one style, there's a distinction between the handwriting I use on things I intend for other people to read and the handwriting I use for myself. The upside: the handwriting for myself is virtually incomprehensible to anyone but someone who's seen it for at least a year and knows the vocabularies I use frequently (I live by the principle, "If you can recognize the first four letters, you should know which word it is."). So, if it's something personal and it gets lost, I don't have to worry about other people reading it. :)
Ah, now, but would you want to be deriving the equations on computer?
I couldn't ever derive anything on computer. When I have to come up with an equation for my lab report, I first write it on a piece of paper, even if I have to retype it (using equation editor) on computer.
One feature that equation-typing seems to lack (disclaimer: I haven't used TeX) is cancellation notation... Sure, I can just delete the corresponding quantities, but, what if I made a mistake and want to look through the steps again? I haven't seen a nontrivial way of denoting that...
So, are you saying that whole "education" thing is ill-conceived and doomed to begin with?
It is the whole point of education program to dissuade them from accessing illegal porns (well, any porn is illegal for kids, if it's like in U.S.). If you are saying that this goal is unreacheable from the start, well, I would like to see some supporting arguments.
BTW, I would rather argue that no amount of "blocking" is really going to stop them or persuade them from accessing it [illegal porns], if they really wanted to. Every firewall/security has a weakness, and for those who really wanted to get it, it's almost trivial effort to find a way to get around it. The solution is in curbing the demand, not the supply.
And I quote:
"If we knew what we were doing it wouldn't be research."
- Albert Einstein
'Got a nice yacht, perchance?
While storage is definitely a big issue that has to be addressed, that's not the first problem. Question is, where do we hydrogen to get started?
"From water (i.e. H2O)" someone might say, but H2O has less energy than H2. So, where do we get that energy to make hydrogen out of water? So far, the only way we have perhaps to mass-produce hydrogen is by electrolysis--using electricity, majority of which comes from fossil fuels.
So, as the situation is now, using hydrogen fuel isn't any more environment-friendly than burning coal to run your car.
Of course, there's the whole alternative energy view, like using photovoltaic cells or wind to generate electricity, but I'm not sure if they are any more cost effective, considering the installation cost (we don't have an infrastructure big enough to support mass-consumption), maintainance, and reliability (or lack thereof).
And somehow, he still managed to get modded down, Troll, -1, rather than up, Funny, +1. :)
From the article: The newly-developed technology uses a water-based solution of sodium borohydride, made from sodium borate, to produce hydrogen gas.
The downside is that there are only about 300 million tons of sodium borate worldwide, located mostly in Tibet, and that annual global production of sodium borohydride stands at 10,000 tons, it added.
So, other than the fact that it produces less pollution (I would hesitate to say less "green gas", though since vapor is a green gas) it has no advantage over gasoline powered scooter.
In fact, have we yet seen any viable hydrogen-powered vehicle? I thought most models/prototypes we have so far were less energy efficient than gasoline powered cars (even with infrastructure to provide hydrogen nation-,world-wide, we have to have a way of generating them, and electrolysis is simply not the most efficient way (and certainly less so than internal combustion) way to get hydrogen).
In context of physics, laws are experimental findings that cannot be explained or derived from other more fundamental equations. Examples are: Coulomb Force Law (Gauss's law is an...almost equivalent law--considered to be more fundamental in electromagnetism); Ampere's law; Biot-Savart Law; Lorentz-Force law (heh... mostly EM examples, since that's what I'm studying now).
Of course, names are sometimes just plain deceptive. A non-example: Ohm's law--which is not a fundamental law but something that can be derived from other force laws and a few more assumptions about the property of the material.
Anyway. A good example of theory is, say, theory of special relativity. The whole theory starts out with two postulates, i) fundamental laws of physics are the same in all inertial frames, and ii) speed of light in vacuum is a constant.
Egh. But what's the point of arguing on semantics. The public may call different things whatever they want, and we physicists will go by our own definitions (public be damned....).
Besides, I don't think the so-called "theory of evolution" really measures up to the standards and definitions used in physics: it may have some quasi-postulates and principles (such as the survival of the fittest), but what quantitative predictions has it made that can be verified experimentally?
From Wikipedia: Mercantilism is the economic theory that a nation's prosperity depended upon its supply of gold and silver, that the total volume of trade is unchangeable.
And naturally, from there comes the whole family of crazy ideas about tariffs and "protecting the domestic industry." But, in this case, I don't see anything related to international trade (the only thing vaguely "international" seems to be, er, something about USA forcing other countries to have similar patent laws...)
So, how is this mercantilism, or were you just using a buzz word without knowing what it meant?
IDK, but I actually find PDF files that are built from JPEG files more detestable. I mean, those files are huge or pixelated and my antiquated computer (not quite antiquated as the ones in the book, though : ) has to struggle to read the whole file (a few megabytes to 20 megabytes, depending on number of pages and how pixelated the pages are) just so that I can read one page.
It would have been very nice if they could put up a properly prepared PDF file, say, exported from the page-setting application they used to make this book...who am I kidding?
Anyway, IMHO, separate JPEG images are easier to read (at least for the computer) and in this case, how would you be able to do a page-by-page comparison between the two editions in PDF?
As is the simple matter of bothering to read about what any old internet site wants to install on your computer (or just any adware in general, whether installed from a website or via a "free" software).
Imagine a scenario where someone owns an, er, expensive car, that should be filled with only highest-octane gas available. If that someone, when filling his tank, doesn't read the labels and puts whatever petroleum product (diesel, basic unleaded, natural gas...) in his car, is he dumb or not?
Most computer users--i.e. most of my friends, who, on the computer user spectrum, are on the brighter side than the national average--are in this way. (And, thus incorrigibly dumb.)
BTW, I wouldn't call "clicking on an icon labeled Internet" "stearing." It's more like "putting key in the key hole." And, now, when you go to a site like Google, then, that's "turning the key once," and when you enter search command, that's now finally "starting the car."
Such advanced skills in driving as steering should be likened to, well, such skills in using computer as steering away from sucky programs like Internet Explorer.
Not to mention very massive (compared to the craft), so that the laser itself doesn't get accelerated to maybe 3,000 km/sec in the process due to conservation of momentum.
Are these real "plans" or are they just made up (er, on the spot)? Lasers, maybe, but microwave transmitters? Microwave has frequency (and thus, momentum per photon) much lower than visible light (in fact, it's right between radio frequency and infrared), and, although I don't know too much details about microwave, simple knowledge (which, I fancy, I possess) of basic physics should say that something with that long a wavelength cannot be focused very well.
In any case, energy conservation (in case of elastic collisions, and for inelastic collisions, well, it's even worse) demands that as much energy as would be needed for a conventional rocket be used to propel those rockets--so, how is that any more effective than what we have now? At least for solar sail, the idea is to harness the energy of the sun, much of which goes wasted, but unless the laser system, on top of being prohibitively large and cost-ineffectively massive, utilizes photovoltaic cells to "continuously recharge themselves" (er... in Data's words in 'Insurrection'), I don't see what the benefit of even considering those plans.
So far, the only human-powered (i.e. non-solar-sail) next generation space rocket idea I heard that makes sense is the one that uses, er, fission explosion at the rear to propel itself.
That would probably depend on the property of the solid that forms when the solution is heated (is it a good insulator? what are its structural properties?), but I can think of one related application: temperature-controlled switch.
The solution is transparent to visible light, whereas the solid that forms is not. Since this process depends on the temperature and is reversible, it's very simple to design a circuit (using a LED and phototransistor or some sort of photo-detector) that works as temperature-dependent switch. From what the article says,
The temperature at which it becomes a solid falls as the concentration of CD increases.
it should be possible to tweak the turn-on temperature to a degree.
But then, this is not anything new--as far as dependence on temperature goes, there are many other materials that are probably more reliable (the only thing novel about this would be that its dependence is backward.)
Back to the topic, yeah, it can probably be used as heat shield in a limited capacity: i.e. if it turns out that the liquid is transparent to infrared radiation while the solid isn't, this can be used as natural temperature-controlled infrared radiation shield (but of course, it will still be subject to heating due to other methods, like...conduction via the solid itself, unless the resulting solid turns out to be similar to styroform).
I see... come to think of it, energy corresponding to 70+ eV is almost half-an-order-of-magnitude larger than the ionization energy of hydrogen. But, in case of H_2, is it really that much of a many-body problem? (I mean, I do understand that it is a four-body problem, but that's not nearly as complicated as solar system...)
Well, on the second thought, I don't remember any treatment of covalent bonding in my QM courses. I probably should ask my GSI when I have a chance.
Hydrogen atom (thus, I think, molecules...) is very well-studied theoretically. Gosh, they don't just stop at calculating different energy levels due to Coulomb force. At third-year level of undergraduate physics classes, they already calculate fine-structure splitting, hyperfine splitting, and even Zeeman splitting, in presense of a magnetic field. At that level, the theory is getting so accurate, and the energy level splitting becomes so small that if you want to fit a photon of right energy between the energy levels, you have to go down to the frequency of radio waves. It's not like we need experimental results (as in the case of more complicated atoms) because you can't solve (or approximate very closely) for the energy levels of the atom.
Since deuterium is practically identical to hydrogen, unless you want to study the nucleus itself (I mean... it's two fermions, so something must be different, even though they are not identical particles), what's the point of publishing results of an experiment like this? This sounds not much more sophisticated (or important) than the experiments done in advanced physics lab (er... optical pumping, Rutherford scattering, NMR, etc. etc.).
It would be a totally different matter if they found something that contradicted predictions of an established theory...but, did they?
But that's not what they want to do. As someone must have (I mean, am I the only person who remembers high school chemistry?) mentioned it already, they are splitting an H_2 molecule into two atoms of H. (At the end, H- ions, presumably.) The fact that they are using deuterium doesn't change anything except that the H- ion is twice as heavy and that the target area (er, "cross-section," is probably the correct term).
BTW, where did you get this quote?
Deuterium has somewhat different chemical properties than hydrogen due to the different nuclear mass (classically, it's a two body problem, look up `reduced mass' if you want more details.) With a larger nucleus mass, the electrons would have a lower average kinetic energy, and by the virial theorem the average potential energy would therefore be higher (KE = - 1/2 PE) (a smaller absolute value, but it's negative, so it's higher) and therefore less tightly bound.
You should tell them to fix their entry--I know what virial theorem is, and I know how to calculate the ionization energy of hydrogen atom. Unless you want to go into fine-structure splitting, most people assume that the nucleus has infinite mass (it's more than 1000 times as heavy as electron, so the error related to the approximation is less than 1 part in 1000). The only thing that's different with deuterium is that now your error is less than 1 part in 2000, if you used the infinitely-massive-nucleus approximation.
Lock them up in their own house, cut their phone/cable? (In that case, are they sure that the withdrawal symptom is due to withdrawal from Internet or from fresh air...who am I kidding?)
Or were they just relying on the subjects' integrity and sense of honor to hold up against the overwhelming withdrawal symptoms? And did they really expect the subjects to be honest about it, if they slipped up?
IDK, but something smells fishy here. This sounds just like the M$ report that says total cost of ownership for linux is higher than M$ servers.
Or this is just a big joke and /. editors are a part of it.
Not at all! :) In fact, the parts I replaced all worked, and the RAM I added were, well, added, as in there were open RAM slots where I just stuck in a couple more sticks. The only computer part that broke down was the hard drive that originally came with my computer...I probably formatted it one too many times. (And well... I probably would have kept using it, but my parents, not wanting to deal with a slightly faulty drive, threw it away.)
I just find it very irresistible when I see someone throwing away a Pentium III 450MHz motherboard and CPU when I'm running a 400MHz. :)
PS. Hmm, BTW, as far as my computing habit goes, my computer is always on, too--to the consternation of my parents...(er, bill anyone?)
The computer I'm using to write this article was bought in 1998. I've done so many upgrade (er, usually throw-out HD's, RAM, and, once, a motherboard), so I'm not quite sure what it is now... but it's one of the oldest computers I've seen around (heck, even the library has newer computers with shinier screens). But running on linux (an LFS system, so it's at the lower end of resource usage, even among linux boxes--it has barely enough for X and some other basic applications I absolutely need and use very often), it's doing O.K., and I would even say it's much faster than my roommates' 1,2-year-old laptops running Windows XP and lots of Adwares, when it comes to loading webpages and checking e-mail.
The only time I felt the need for more computing power was when I was actually building the system--so much compiling, so much time.
And if I got a dime every time I heard an implausible hypothetical situation...
FYI, my linux box didn't run openssh (or any kind of ssh at all) until the server hosting my website (er... it's a student organization at my school) decided that it will discontinue all "insecure" telnet and ftp services.
In any case, the point is, in order to get rid of that kind of virus, all an admin has to do (at the most extreme case) is "userdel IdiotJoe -r" (and hopefully IdiotJoe didn't have any permission to write anything outside his own home directory and /tmp.)