Anytime quantum mechanics is brought up among a non-science crowd (sorry, desipte the geekyness of slashdot, the moderation and general comments I see indicate it's a non-science crowd) you wind up getting half-truth mystical garbage.
There are broad philosophical questions that are beyond the scope of science, yet are tied intimately with it, as science encapsulates the current knowlege we have about the physical universe. If one seeks to use logic (as in philosophy) to make arguments about the universe, even those beyond the scope of strict naturalism, it is often useful to look at philosophical interpretations of scientific theories - it can lead to complex notions of chance, fate, and even purpose. Just because something is not merely the result of applying the scientific method, does not mean it has no philosophical value - a common error made by many posters on slashdot.
Many of Einsteins scientific breakthroughs (his work on Bose-Einstein Condensates, and EPR paradox) were made precisely because of "unscientific" philosophical interpretations of quantum theory - "God does not play dice," etc. Conversely,
his work, along with further experimental observation, has shown that there is an apparently unreconcilable conflict between the intuitive philosophy we have of the universe on our scale, and the underlying "reality" (or non-reality) of the physical universe.
Science is not the end-all and be all of logical knowlege - it is only the beginning. There are more questions in life than "how can I predict the result of a given experiment" - the only question that science can attempt to answer on its own.
In any case, the application domain doesn't really matter much; the UI itself is a rip-off of numerous NeXT and Smalltalk interfaces... But there is something wrong about it when Apple complains about it, given that their entire company is based on taking the best ideas out of other UIs and then modifying them.
Still, any image from the Commons should be OK, as should any image from en.wikipedia.org that has a free license tag.
That's the problem, there's a ton of mis-tagged images on Wikipedia, and even the commons. There's a bunch of idiots out there who think that all material produced by government contractors (like the Jet Propulsion Lab) are magically public domain just because they have a.gov domain name, despite the fact that there exists explaination of the proper procedures for copyright checking on the Wikipedia FAQs. A lot of stuff on government websites is from a secondary source and likely copyrighted as well - the FAQs mention this too but this doesn't stop folks who are too lazy to check.
My former officemate was a lawyer dealing with Cornell/JPL relations, and if my experience with that has taught me anything, it's that Caltech does not treat abridgement of its rights lightly.
This is just speculation of course, but maybe Google is waiting to see where Wikipedia is going first? Wikipedia's doing just fine for google (through answers.com) as is - why spend extra money on something you can get for free?
Also, Wikipedia contains a massive amount of copyrighted content (mostly "fair use" images that have not been legally tested)... and some folks are trying to bring a class action suit against Wikipedia - does Google really want to open themselves up to more legal action?
I think it'd be smarter for Google to make some hefty donations and then reap secondary benefits, but with some nice legal isolation.
In all seriousness - yes/. has inevitably declined, but are there better tech news web sites out there that offer both articles *and* good comments? I read some of the articles on slashdot, but I'm really here for the discussion. Yes a lot of it is noise but with a bit of help from the moderation system, it's not too hard to weed out the absolute morons. Do you reccomend any replacement web sites for either articles or discussion?
On another note - I think that sometime in the near future "elitist" discussoni web sites (web sites with some minimal entry critereon to weed out people who don't know what they are talking about) will probably take off... I'm looking forward to this, because I'm an elitist bastard:)
At least the department store removes the tag after you buy it.
Not always, a J.C. Penny's forgot to remove a tag from a suede shirt I bought, and I didn't notice till I had gone back to my apartment in a different state. Luckily a few sheets of paper stuck carefully between the tag and the clothing can prevent contamination.
The decoding functions provided in LAME use the mpglib decoding engine which is under the GPL. They may not be used by any program not released under the GPL unless you obtain such permission from the MPG123 project (www.mpg123.de).
This, my friends, is why I can't stand libraries for "standards" or "formats" that are licensed under the GPL. The LGPL seems to be the appropriate thing here - if someone improves your code, there's nothing wrong with expecting those improvements to be released. But why, oh why should I have to release some giant piece of software's source code, just because I used an open-source codec? Chances are much, if not all of the software has little or nothing to do with the codec. I'm all for giving back to the community - I would love to see more technological innovation flowing back into the public realm via LGPL - we live in an age where we desperately need broad support from industry for open standards, and FOSS is an excellent way to go about this - if we use non-crippling licenses.
That being said, I hope Sony, and our computer-crippling corporate overlords, whom I, for one, do not welcome, learn a valuable lesson here.
While wandering around at Cal Tech (which does much of the research involving LIGO), I happened upon an astronomy lounge, where I found a small device that looked like a car battery charger, but on top of it were two metal balls connected by another piece of metal, such that they could be spun around. It was imply labeled "gravitational wave generator." At first I thought it was some kind of ridiculous joke, but now that I think of it, at very close distances that may in fact actually help them calibrate it.
The wavelength of an electron is extremely tiny compared to the wavelength of light. This means that feature sizes for light based chips are necessarily much larger than those for electron based chips.
However, the momenta of photons is *MUCH* smaller than electrons, and as they are bosons, (barring nonlinear effects) one can have photons flowing through each other without causing interference (whereas electrons flowing even in wires nearby can cause interference). This means faster accelleration times, and theoretically *MUCH* less energy consumption.
Also the speed of light in a dielectric is often faster than the speed of signal propagation in conductive traces used in modern processors.
Add to that the fact that these chips could be immune to EMP, EMF, etc...
" The toaster will try to distract you with light, morning conversation and offer you a variety of toasted bread products."
Didn't they alreay do this on Red Dwarf:
The TOASTER lights up and speaks. Its bread-lowering lever moves up and down as it speaks with its mid-Atlantic accent in an impossibly cheerful tone:
TOASTER: Howdy doodly do! How's it going? I'm Talkie -- Talkie Toaster, your chirpy breakfast companion. Talkie's the name, toasting's the game. Anyone like any toast?
LISTER: Look, I don't want any toast, and he (indicating KRYTEN) doesn't want any toast. In fact, no one around here wants any toast. Not now, not ever. NO TOAST.
TOASTER: How 'bout a muffin?
LISTER: OR muffins! OR muffins! We don't LIKE muffins 'round here! We want no muffins, no toast, no teacakes, no buns, baps, baguettes or bagels, no croissants, no crumpets, no pancakes, no potato cakes and no hot-cross buns! And DEFINITELY. NO. SMEGGIN'. FLAPJACKS!
TOASTER: Aah, so you're a waffle man!
Or worse yet, "Something that can be removed from your body with a saw;" in the case of biometrics. This is why biometrics don't appeal to me...
You said it, man.
P.S. It's this kind of thing that makes me want to vote libertarian, as maybe companies won't be as stupid as the government about such biometric identity...
As with all other so-called "security" schemes, it comes down to trusting the luser. Unfortunately in today's climate, this seems to be a losing proposition.
"Something you have, and something you know" becomes "Something you can lose, and something you can forget."
Seriously. Why? There's no room for debate on the point that you do, as you are trying to censor rather than debate, so the only question is, why do you hate Free Speech?
Alright... I'm not going to defend the grandparent, but seriously I get *MY* panties all in a knot when I see people talk about moderation as "censorship." (despite the fact that constituional limits on censorship only applies to government action!) The moderation system on slashdot is a lot like a spam filter - it suggests to you what posts are worth reading, and what are not. It's nothing but a suggestion, even if it is one with a lot of sway.
The right to speak is not the same as the right to be heard (I'm allowed to ignore people online etc), and there's the system is designed to allow moderators to use their judgement about how worthwhile a post is. Granted the mods are often on crack, and this type of "majority is always right" nonsense ends up heavily promoting groupthink (Microsoft 100% evil, Linux 100% good, etc), but even still I find it a useful service as 90% of the posts out there are simply not worth reading IMHO. I dislike reading unmoderated forums for this reason.
Whether or not the grandparent's plea to have great-grandparent modded down is acted upon is entire up to the mods. If you feel that moderation is censorship, then maybe it is best for you to post on unmoderated messageboards, or to encourage people to browse at -1 to reduce the influence of/. moderators. If you feel someone's rights are being violated I think you should take action rather than simply complain about what someone else is saying (indeed, that would be the ultimate hypocrisy, saying that free speech is important except for those who disagree with your notions about free speech).
As for me, I'm doing my best to solve the/. moderation problem by constructing a moderation algorithm using clustering etc that should be much more effective and relatively immune to the homogenizing effects of single-rating, nonadaptive moderation... but until I get that figured out, I would ask that all the 1st amendment buffs out there remember the difference between labeling and censorship.
After all, don't I have a right to say "Mod this sucker down?"
But it's never a good idea to take these announcements at face value. It's far from clear the thing has anything to do with a supernova, or that it's a neutron star at all -- presuming any of them exist at all. What we do know is that its light (radio, x-rays, etc.) pulses at a rate too fast for them to understand unless it's a tiny thing spinning.
The reason they insist it has to be something spinning is that they have studied almost no plasma fluid dynamics, so they can't understand something blasting out radio, light, and x-rays that doesn't have a star in the middle of it.
Once long ago, pulsars were discovered. The majority view at the time was that this type of oscillation must be caused by a star expanding and contracting - becoming dimmer and brighter over time. This theory was widely held until it was shattered by Professor Thomas Gold, of Cornell University, with whom I worked until his death. He showed statistically that the pulses had regular patterns which would only arise from a process where a driving momentum was continuously stabilizing the signal - preventing a phase drift in a way which was extremely unlikely in any process lacking a dominating momentum term. At first his theory that pulsars were neutron stars was considered so outrageous that he was not allowed to defend it at a conference - until the discovery of a pulsar in the Crab Nebula gave irrefutable evidence. After this it has been rarely questioned that pulsars are neutron stars - the theory fits the facts far too precisely, as no alternative "non-crackpot" theory has been able to do so since. The existance of neutron stars is heavily supported by relativity, the Standard Model for particle physics, and simulation of supernova explosions, among other things.
They don't understand fluid instabilities and current oscillations, so they're at a complete loss to understand the (quite common) sudden, often temporary changes in oscillation rate in pulsars.
Claiming to know something the entire astrophysics community does not? Why am I not surprised to find this nonsense on slashdot? After checking out another post you wrote, I can see you have some kind of agenda against the astrophysics community as a whole. Apparently any kind of explaination that doesn't meet with your intuition could not possibly be correct (you consider gravitational lensing to be an iffy phenomena, despite the fact that it's been observed happening in our very own solar system, in accordance to general relativity, since 1919! I do not understand how you can ignore such experimental observation and still take yourself seriously. I know Dark Matter is a bit difficult to swallow - something out there exists but it's difficult to observe directly - but "magnetic reconnection" is not entirely difficult to understand - you just have to realize that the term only makes sense when describing the nature of magnetic fields *inside* a moving plasma conductor, and in fact the actual B-field does not reconnect, but the H-field, which is a conceptual stand-in for the reaction of the B field and the plasma (much in the same way as the magnetic field itself is unnecessary to explain the universe - electrodynamics and special relativity alone handle that, but the notion of a B-field is convenient mathematical/theoretical abstraction) does "reconnect" - another process we can observe happening in our own galaxy during solar flares.
What little they have studied, typically, is a trivial approximation to plasma fluid dynamics known as "magneto- hydro-dynamics" (MHD) which assumes space is superconducting and magnetic fields can't change distribution or strength.
I work with the parallelization of second order three dimensional magnetohydrodynamics code at Cornell University. Space is *IN NO WAY* assumed to be superconducting - rather areas
No, It's not just some ordinary fluid. You try to apply the basic hydrodynamic equations to these systems and you will get nonsense. The term is magneto-hydrodynamics (MHD), it's a electrically conductive plasma, not just an ordinary fluid.
Yes I am aware of this, if you like you can see results from a paper that I collaborated on (parallelization of 3D MHD code with full equations, Gudenov method)
here. I must admit that during my degree process I did not take astrophysics classes, only working as a research assistant. I do think, however, that some levels of detail are inappropriate for this audience) as when discussing linear wave propagation in a fluid, it is not customary to require full navier-stokes equations, but rather the more familiar wave equation (which, for linear wave propagation, even magnetohydrodynamic fluids can be reduced to by some approximation). I suppose it could be argued that for discussion of supersonic shocks one would need a better approximation but... I stand by my assertion that ISM can be characterized as a fluid (at least I know this is what is taught in university classes as you can see in course notes on the web). for exotic phenomena and long-range interactions, or regions with large electromagnetic fields, perhaps full MHD equations are necessary, but I fail to see what thez have to do with the discussion of this article.
Good luck finding naturally occuring hard vacuum anywhere inside our galaxy, as it's permiated by the Interstellar Medium (ISM).
The ISM is a fluid much like any other (albeit extremely rarified), and is capable of transmiting sound waves, shock waves, etc, on very large scales.
A short little presentation mentioning supersonic shocks ("sonic booms") caused by objects propagating through the ISM can be found
here. Another site with some great pictures is my advisor's site here.
Sorry to get technical but I get really annoyed by ignorant individuals "correcting" other people's technical errors with sarcastic comments that are just as ridiculolous. (And yes, I know that the use of "supersonic" in this case was probably not taking into account the heliospheric medium's properties, but rather making a comparison to the terrestrial atmosphere at STP... I think it's pretty clear that the individuals responsible here have a poor understanding of physics.)
This article exposes some of the issues involving FairTax. I was rather surprises that there could be so many problems with it (after all, seems simple enough, right?) Between black market increase, unfairness to those with pre-taxed savings (Baby Boomers), and troubles with the housing market... I'm not sure I'm convinced this is the right thing.
I also believe it is likely that we will end up with both a National Sales Tax *AND* an Income Tax. Yuck.
Check out MIT's OpenCourseWare. Many of MIT's classes materials all available freely online. If you are looking to learn computer science, it's hard to find a better curriculum.
Is the MER science operations mailing list (mentioned in the slashdot story) open to the public? Anyone know how I can sign up to it? I could find a Mars Missions list on the JPL site, but couldn't see a MER specific one.
No, the list is closed to mission personelle. I do know that several high profile journalists get regular forwards from the list, however. If you're not a journalist, though, you're probably out of luck.
(if we get to sol 1000, just about every piece of ground software will be inoperable)
Hm, why is that? Will their system clock roll over?
Well, most of the software developed at JPL for the mission uses three digits to encode the sol number. Once we are past 999, this software, as written, will cease to function properly. This is something that can be fixed, but I believe it would take a lot of effort. It will be a miracle if we need to do that, but it's possible one of the rovers will still be marginally operational at that point.
Slashdot Mirror
Anytime quantum mechanics is brought up among a non-science crowd (sorry, desipte the geekyness of slashdot, the moderation and general comments I see indicate it's a non-science crowd) you wind up getting half-truth mystical garbage.
There are broad philosophical questions that are beyond the scope of science, yet are tied intimately with it, as science encapsulates the current knowlege we have about the physical universe. If one seeks to use logic (as in philosophy) to make arguments about the universe, even those beyond the scope of strict naturalism, it is often useful to look at philosophical interpretations of scientific theories - it can lead to complex notions of chance, fate, and even purpose. Just because something is not merely the result of applying the scientific method, does not mean it has no philosophical value - a common error made by many posters on slashdot.
Many of Einsteins scientific breakthroughs (his work on Bose-Einstein Condensates, and EPR paradox) were made precisely because of "unscientific" philosophical interpretations of quantum theory - "God does not play dice," etc. Conversely, his work, along with further experimental observation, has shown that there is an apparently unreconcilable conflict between the intuitive philosophy we have of the universe on our scale, and the underlying "reality" (or non-reality) of the physical universe.
Science is not the end-all and be all of logical knowlege - it is only the beginning. There are more questions in life than "how can I predict the result of a given experiment" - the only question that science can attempt to answer on its own.
In any case, the application domain doesn't really matter much; the UI itself is a rip-off of numerous NeXT and Smalltalk interfaces... But there is something wrong about it when Apple complains about it, given that their entire company is based on taking the best ideas out of other UIs and then modifying them.
You do know that Apple bought NeXT, don't you?
Still, any image from the Commons should be OK, as should any image from en.wikipedia.org that has a free license tag.
.gov domain name, despite the fact that there exists explaination of the proper procedures for copyright checking on the Wikipedia FAQs. A lot of stuff on government websites is from a secondary source and likely copyrighted as well - the FAQs mention this too but this doesn't stop folks who are too lazy to check.
That's the problem, there's a ton of mis-tagged images on Wikipedia, and even the commons. There's a bunch of idiots out there who think that all material produced by government contractors (like the Jet Propulsion Lab) are magically public domain just because they have a
My former officemate was a lawyer dealing with Cornell/JPL relations, and if my experience with that has taught me anything, it's that Caltech does not treat abridgement of its rights lightly.
C'mon, buy Wikipedia already.
This is just speculation of course, but maybe Google is waiting to see where Wikipedia is going first? Wikipedia's doing just fine for google (through answers.com) as is - why spend extra money on something you can get for free?
Also, Wikipedia contains a massive amount of copyrighted content (mostly "fair use" images that have not been legally tested)... and some folks are trying to bring a class action suit against Wikipedia - does Google really want to open themselves up to more legal action?
I think it'd be smarter for Google to make some hefty donations and then reap secondary benefits, but with some nice legal isolation.
In all seriousness - yes /. has inevitably declined, but are there better tech news web sites out there that offer both articles *and* good comments? I read some of the articles on slashdot, but I'm really here for the discussion. Yes a lot of it is noise but with a bit of help from the moderation system, it's not too hard to weed out the absolute morons. Do you reccomend any replacement web sites for either articles or discussion?
:)
On another note - I think that sometime in the near future "elitist" discussoni web sites (web sites with some minimal entry critereon to weed out people who don't know what they are talking about) will probably take off... I'm looking forward to this, because I'm an elitist bastard
Sorry I couldn't resist
/..
Few people have that capacity.
The story just induces bad jokes, doesn't it?
This thread shows there is little impedance to such humor on
At least the department store removes the tag after you buy it.
Not always, a J.C. Penny's forgot to remove a tag from a suede shirt I bought, and I didn't notice till I had gone back to my apartment in a different state. Luckily a few sheets of paper stuck carefully between the tag and the clothing can prevent contamination.
The decoding functions provided in LAME use the mpglib decoding engine which is under the GPL. They may not be used by any program not released under the GPL unless you obtain such permission from the MPG123 project (www.mpg123.de).
This, my friends, is why I can't stand libraries for "standards" or "formats" that are licensed under the GPL. The LGPL seems to be the appropriate thing here - if someone improves your code, there's nothing wrong with expecting those improvements to be released. But why, oh why should I have to release some giant piece of software's source code, just because I used an open-source codec? Chances are much, if not all of the software has little or nothing to do with the codec. I'm all for giving back to the community - I would love to see more technological innovation flowing back into the public realm via LGPL - we live in an age where we desperately need broad support from industry for open standards, and FOSS is an excellent way to go about this - if we use non-crippling licenses.
That being said, I hope Sony, and our computer-crippling corporate overlords, whom I, for one, do not welcome, learn a valuable lesson here.
Is there some form of callibration.
While wandering around at Cal Tech (which does much of the research involving LIGO), I happened upon an astronomy lounge, where I found a small device that looked like a car battery charger, but on top of it were two metal balls connected by another piece of metal, such that they could be spun around. It was imply labeled "gravitational wave generator." At first I thought it was some kind of ridiculous joke, but now that I think of it, at very close distances that may in fact actually help them calibrate it.
The wavelength of an electron is extremely tiny compared to the wavelength of light. This means that feature sizes for light based chips are necessarily much larger than those for electron based chips.
However, the momenta of photons is *MUCH* smaller than electrons, and as they are bosons, (barring nonlinear effects) one can have photons flowing through each other without causing interference (whereas electrons flowing even in wires nearby can cause interference). This means faster accelleration times, and theoretically *MUCH* less energy consumption.
Also the speed of light in a dielectric is often faster than the speed of signal propagation in conductive traces used in modern processors.
Add to that the fact that these chips could be immune to EMP, EMF, etc...
" The toaster will try to distract you with light, morning conversation and offer you a variety of toasted bread products." Didn't they alreay do this on Red Dwarf: The TOASTER lights up and speaks. Its bread-lowering lever moves up and down as it speaks with its mid-Atlantic accent in an impossibly cheerful tone: TOASTER: Howdy doodly do! How's it going? I'm Talkie -- Talkie Toaster, your chirpy breakfast companion. Talkie's the name, toasting's the game. Anyone like any toast? LISTER: Look, I don't want any toast, and he (indicating KRYTEN) doesn't want any toast. In fact, no one around here wants any toast. Not now, not ever. NO TOAST. TOASTER: How 'bout a muffin? LISTER: OR muffins! OR muffins! We don't LIKE muffins 'round here! We want no muffins, no toast, no teacakes, no buns, baps, baguettes or bagels, no croissants, no crumpets, no pancakes, no potato cakes and no hot-cross buns! And DEFINITELY. NO. SMEGGIN'. FLAPJACKS! TOASTER: Aah, so you're a waffle man!
Or worse yet, "Something that can be removed from your body with a saw;" in the case of biometrics. This is why biometrics don't appeal to me...
You said it, man.
P.S. It's this kind of thing that makes me want to vote libertarian, as maybe companies won't be as stupid as the government about such biometric identity...
As with all other so-called "security" schemes, it comes down to trusting the luser. Unfortunately in today's climate, this seems to be a losing proposition. "Something you have, and something you know" becomes "Something you can lose, and something you can forget."
Why do you hate Free Speech?
/. moderators. If you feel someone's rights are being violated I think you should take action rather than simply complain about what someone else is saying (indeed, that would be the ultimate hypocrisy, saying that free speech is important except for those who disagree with your notions about free speech).
/. moderation problem by constructing a moderation algorithm using clustering etc that should be much more effective and relatively immune to the homogenizing effects of single-rating, nonadaptive moderation... but until I get that figured out, I would ask that all the 1st amendment buffs out there remember the difference between labeling and censorship.
Seriously. Why? There's no room for debate on the point that you do, as you are trying to censor rather than debate, so the only question is, why do you hate Free Speech?
Alright... I'm not going to defend the grandparent, but seriously I get *MY* panties all in a knot when I see people talk about moderation as "censorship." (despite the fact that constituional limits on censorship only applies to government action!) The moderation system on slashdot is a lot like a spam filter - it suggests to you what posts are worth reading, and what are not. It's nothing but a suggestion, even if it is one with a lot of sway.
The right to speak is not the same as the right to be heard (I'm allowed to ignore people online etc), and there's the system is designed to allow moderators to use their judgement about how worthwhile a post is. Granted the mods are often on crack, and this type of "majority is always right" nonsense ends up heavily promoting groupthink (Microsoft 100% evil, Linux 100% good, etc), but even still I find it a useful service as 90% of the posts out there are simply not worth reading IMHO. I dislike reading unmoderated forums for this reason.
Whether or not the grandparent's plea to have great-grandparent modded down is acted upon is entire up to the mods. If you feel that moderation is censorship, then maybe it is best for you to post on unmoderated messageboards, or to encourage people to browse at -1 to reduce the influence of
As for me, I'm doing my best to solve the
After all, don't I have a right to say "Mod this sucker down?"
But it's never a good idea to take these announcements at face value. It's far from clear the thing has anything to do with a supernova, or that it's a neutron star at all -- presuming any of them exist at all. What we do know is that its light (radio, x-rays, etc.) pulses at a rate too fast for them to understand unless it's a tiny thing spinning.
The reason they insist it has to be something spinning is that they have studied almost no plasma fluid dynamics, so they can't understand something blasting out radio, light, and x-rays that doesn't have a star in the middle of it.
Once long ago, pulsars were discovered. The majority view at the time was that this type of oscillation must be caused by a star expanding and contracting - becoming dimmer and brighter over time. This theory was widely held until it was shattered by Professor Thomas Gold, of Cornell University, with whom I worked until his death. He showed statistically that the pulses had regular patterns which would only arise from a process where a driving momentum was continuously stabilizing the signal - preventing a phase drift in a way which was extremely unlikely in any process lacking a dominating momentum term. At first his theory that pulsars were neutron stars was considered so outrageous that he was not allowed to defend it at a conference - until the discovery of a pulsar in the Crab Nebula gave irrefutable evidence. After this it has been rarely questioned that pulsars are neutron stars - the theory fits the facts far too precisely, as no alternative "non-crackpot" theory has been able to do so since. The existance of neutron stars is heavily supported by relativity, the Standard Model for particle physics, and simulation of supernova explosions, among other things.
They don't understand fluid instabilities and current oscillations, so they're at a complete loss to understand the (quite common) sudden, often temporary changes in oscillation rate in pulsars.
Claiming to know something the entire astrophysics community does not? Why am I not surprised to find this nonsense on slashdot? After checking out another post you wrote, I can see you have some kind of agenda against the astrophysics community as a whole. Apparently any kind of explaination that doesn't meet with your intuition could not possibly be correct (you consider gravitational lensing to be an iffy phenomena, despite the fact that it's been observed happening in our very own solar system, in accordance to general relativity, since 1919! I do not understand how you can ignore such experimental observation and still take yourself seriously. I know Dark Matter is a bit difficult to swallow - something out there exists but it's difficult to observe directly - but "magnetic reconnection" is not entirely difficult to understand - you just have to realize that the term only makes sense when describing the nature of magnetic fields *inside* a moving plasma conductor, and in fact the actual B-field does not reconnect, but the H-field, which is a conceptual stand-in for the reaction of the B field and the plasma (much in the same way as the magnetic field itself is unnecessary to explain the universe - electrodynamics and special relativity alone handle that, but the notion of a B-field is convenient mathematical/theoretical abstraction) does "reconnect" - another process we can observe happening in our own galaxy during solar flares.
What little they have studied, typically, is a trivial approximation to plasma fluid dynamics known as "magneto- hydro-dynamics" (MHD) which assumes space is superconducting and magnetic fields can't change distribution or strength.
I work with the parallelization of second order three dimensional magnetohydrodynamics code at Cornell University. Space is *IN NO WAY* assumed to be superconducting - rather areas
That is the single most horrifying thing I've read in a long time.
Please do not do that again!
No, It's not just some ordinary fluid. You try to apply the basic hydrodynamic equations to these systems and you will get nonsense. The term is magneto-hydrodynamics (MHD), it's a electrically conductive plasma, not just an ordinary fluid.
Yes I am aware of this, if you like you can see results from a paper that I collaborated on (parallelization of 3D MHD code with full equations, Gudenov method) here. I must admit that during my degree process I did not take astrophysics classes, only working as a research assistant. I do think, however, that some levels of detail are inappropriate for this audience) as when discussing linear wave propagation in a fluid, it is not customary to require full navier-stokes equations, but rather the more familiar wave equation (which, for linear wave propagation, even magnetohydrodynamic fluids can be reduced to by some approximation). I suppose it could be argued that for discussion of supersonic shocks one would need a better approximation but... I stand by my assertion that ISM can be characterized as a fluid (at least I know this is what is taught in university classes as you can see in course notes on the web). for exotic phenomena and long-range interactions, or regions with large electromagnetic fields, perhaps full MHD equations are necessary, but I fail to see what thez have to do with the discussion of this article.
Supersonic speed in hard vaccuum? interesting...
Good luck finding naturally occuring hard vacuum anywhere inside our galaxy, as it's permiated by the Interstellar Medium (ISM).
The ISM is a fluid much like any other (albeit extremely rarified), and is capable of transmiting sound waves, shock waves, etc, on very large scales. A short little presentation mentioning supersonic shocks ("sonic booms") caused by objects propagating through the ISM can be found here. Another site with some great pictures is my advisor's site here.
Sorry to get technical but I get really annoyed by ignorant individuals "correcting" other people's technical errors with sarcastic comments that are just as ridiculolous. (And yes, I know that the use of "supersonic" in this case was probably not taking into account the heliospheric medium's properties, but rather making a comparison to the terrestrial atmosphere at STP... I think it's pretty clear that the individuals responsible here have a poor understanding of physics.)
This article exposes some of the issues involving FairTax. I was rather surprises that there could be so many problems with it (after all, seems simple enough, right?) Between black market increase, unfairness to those with pre-taxed savings (Baby Boomers), and troubles with the housing market... I'm not sure I'm convinced this is the right thing.
I also believe it is likely that we will end up with both a National Sales Tax *AND* an Income Tax. Yuck.
Yum!
7 hour power outage at work last night... 34 CPUs to reboot, have to pick up all the pieces - but you just made my day sir. Thanks!
Check out MIT's OpenCourseWare. Many of MIT's classes materials all available freely online. If you are looking to learn computer science, it's hard to find a better curriculum.
When the space elevator is built, just what kind of elevator music will it have?
It's a Small World After All?
*cringe*
Is the MER science operations mailing list (mentioned in the slashdot story) open to the public? Anyone know how I can sign up to it? I could find a Mars Missions list on the JPL site, but couldn't see a MER specific one.
No, the list is closed to mission personelle. I do know that several high profile journalists get regular forwards from the list, however. If you're not a journalist, though, you're probably out of luck.
(if we get to sol 1000, just about every piece of ground software will be inoperable)
Hm, why is that? Will their system clock roll over?
Well, most of the software developed at JPL for the mission uses three digits to encode the sol number. Once we are past 999, this software, as written, will cease to function properly. This is something that can be fixed, but I believe it would take a lot of effort. It will be a miracle if we need to do that, but it's possible one of the rovers will still be marginally operational at that point.