Isn't that like using a deadbolt lock AND the little clasp on the screen door? Yes, the clasp is a "lock" just like the fingerprint scanner, but it isn't really the "secure" part of the solution.
This is completely unlike that. This is more like replacing a physical key with a keycard. Still same lock technology, just different way to open the lock. If the data is stored on the USB stick in the clear, with the fingerprint only used through an authentication mechanism, then reading the memory directly can get the data (say by physically taking the memory chips out of the stick and putting them in another stick). You don't need to know the fingerprint. On the other hand, if you use the fingerprint as an encryption key for the data, it does help. It means that an attacker has to know the fingerprint. The fingerprint reader saves you the bother of memorizing the encryption key.
In reality, Wikipedia is too large to have cohesive policy of this type. Rather, it is very fragmented with a large number of groups and projects, each with its own standards of quality, reliability and notability. In Mathematics, Wikipedia has become the de-facto first reference for definitions. I wouldn't use it for research results, but if you need to know what a contravariant functor is, or the basic construction of Hausdorff measure then starting at Wikipedia works. The same holds for some fields of theoretical physics. And this is perfectly compatible with there being large swathes of the encyclopedia devoted to debating the special power sof minor characters in little-known Japanese manga, written using in-universe language. The point is that most users can easily tell the difference between the two kinds of pages.
Even though they acknowledge that others have criticized the design on the amount of weight required to make the lamp work, the news release goes on to correct itself only in the matter of "future developments of LED technology."
Did you read my comment? you seem to have missed the point entirely. It's true that with current LED technology, the lamp would weight tons. However, current technology is already pretty good: it converts about 10% of the incoming energy to light. A 100% efficient LED from the future will only require one-tenth the energy, but one-tenth of many tons is still about a ton. It's true that a future LED that outputs about a thousand times more light than the energy put into it would work well, but I think we can agree that writing about technology which egeegiously violates the law of conservation of energy should be thought of as science fiction, not science journalism.
The people who have the qualifications to understand scientific papers (the ones with science education) can usually get better-paying jobs in science, rather than science journalism.
Worse, our society as a whole is anti-intellectual and specifically anti-scientific. This does not only apply to the readers: many people who study journalism have a weak science background. As long as society can accept someone as "educated" who cannot explain how a refrigerator works, or accept some definitions and follow a mathematical proof based on them, it is hardly surprising that science writers and readers can't understand a scientific argument.
Today's readers are trying to be entertained, not be informed. A piece that reinforces the reader's prejudices will make the reader feel good, and hence buy more copies of the publication.
For an example for the second point, remember the "gravity-powered lamp" concept that was advertized last month? I saw several independent write-ups in newspapers all repeating the canard of "this will work if only we have better LED technology" when an elementary calculation shows that even with 100% efficient lighting elements the lamp will need to weigh about a ton.
Does it really feel like there is too much math on Slashdot?
No, it feels like there is the wrong math on Slashdot. What is needed are stories explaning accessible mathematics to a general audience. Not needed are stories about technical advances in mathematics. Two years ago there was a big hoopla about the calculation of the unitary dual of the split real form of $E_8$, which was a more important result and still completely irrelevant to the general public and impossible to explain even in the vaguest terms. There exists blogs by mathematicians where new math results are discussed. Slashdot should find stories which explain ideas of math, and report the occasional genuine breakthrough.
For CS, which is closer to the readership than Math, the bar should be lower. Deterministic poly-time primality testing was reported; a faster matrix multiplication algorithm, or even a faster factorization algorithm should be reported even if the details of the algorithm will not be reportable.
Read the paper. This is not the first S-C formula for multiply connected regions. The claimed "key result" is a formula for a case where a formula is already known. More work will be needed to a adapt the MATLAB technology from singly- and doubly-connected regions to multiply connected regions.
This paper seems to be part of ongoing work by a small community and is probably useful, but it's not a major mathematical breakthrough -- more of an incremental step. Small technical improvements in one field of mathematics shouldn't make up a slashdot story. Just because someone put "140 year old" in the press release doesn't mean it's really important. A math story belongs on/. when a big result is announced -- on the level of Poincare's Conjecture, or the Modularity Theorem.
Unless you're talking about the big bang, which is what this computation is all about trying to understand.
Actually, this computation has nothing to do with the big bang. This a computation is about trying to see whether we can make sufficiently accurate (computer) calculations within QCD (our theory of quarks and elementary particles made from them) to understand particles at ordinary energy scales. This is actually quite hard (for reasons that would be hard to explain here). Making sure QCD correctly predicts the mass of the proton should come before worrying about the big bang (where physics beyond QCD will play a role anyway, and where we don't have any experimental data to compare our calculations with).
For a different perpsective, before worrying about incorporating gravity, you might want to note that this calculation only involved the 3 lightest quarks (up, down and strange), completely neglecting contributions from processes involving the other 3 quarks.
Gravity -- certainly the weakest force -- is completely irrelevant as far as the physics of elementary particles is concerned. In real life there is no way to observe any kind of gravitational interactions on the scales where the other forces are relevant. In particular, if there is physics just beyond the standard model it need not have any connection to gravity. It's true that gravity is relevant on extremely large scales, but for these scales we have perfectly good theories (GR; in fact Newtonian gravity is quite sufficient in almost all cases). You'd have to go to Planck scale before there'll be any guarantee of gravitational effects playing a role.
This is not to say that a quantum theory including gravity is not an important goal of theoretical physics, it's just to say that so far we have not found any real-life situations where such a theory would be needed, that is when corrections due to quantum gravity would play any role whatsoever. Hopefully the LHC will probe the physics beyond the standard model. The number of orders of magnitude between the energy scales we can actually observe and the quantum gravity energy scale make it extremely unlikely, however, that gravity will be relevant to experimental fundamental physics for many millenia.
I think the new offering, while cheaper, is rather inferior to the product you bought. Thoses iPhones where the same phones before and after the price reduction.
Microsoft has been using the same tactic for the OOXML meetings (remember the incident in Sweden?) I guess manipulating public meetings is the next form of business competition.
Look at it this way, if someone offers to buy a house for you, does accepting the offer mean that you don't have the money yourself?
If someone offered to buy a house for me, on condition that all my friends will have to pay him rent to visit, I would be quite concerned, and might decline the offer.
Don't forget that LoC is not a private company -- it is actually charged with providing a public service. Once this spiffy public service becomes accessible only to those members of the public who first purchased a product from a specific private company (coincidentally, the one that made the "donation"), you are in serious trouble. The alternative is between having a ``free'' extra-spiffy website only accessible to Microsoft's clients, or a less-spiffy website accessible to everyone, but paid for by the LoC. It's true that the taxpayers would save money upfront were MS to build the website, but they would then have to pay the "microsoft tax" to use the website later. That is quite unfair, especially to those of us who are more comfortable with other operating systems.
The ruling says that removing a "digital watermark" triggers some DMCA sanctions: the guy embedded a digital watermark saying the image was copyrighted by him, using a particular watermarking tool. The posted images lacked the watermark. The court ruled that this meant they "removed copyright control information". I'm all for punishing copyright infringers, but note that in general there is no way to tell if a watermark has been embedded in an image or not. So, this metes out extra punishment for copyright infringement based on the rights holder embedding an undetectable booby-trap in the copyrighted work. I'm not sure I'm comfortable with that.
There's a difference between being poor and having to meet a budget.
In case this wasn't obvious, my point is the following: given the choice of spending $3M of its budget and getting a system which works for everyone, or getting the project funded by Microsoft and getting a system which is only usable by people who first pay a Microsoft tax, LoC prefers to get the funding from MS. To me this means that they are so short of cash that the alternative to getting the "donation" from Microsoft is no website at all.
The donations of the kiosks don't lock up anything. But making the website depend on a media format that is not a common web standard and is furthermore specific to Microsoft risks a situation where the only way to get the full functionality of the LoC website would be to install Internet Explorer.
Remaking myloc.gov in silverlight doesn't bother me as long as they don't lock out non-silverlight enabled browsers. If I suddenly can't browse a government website
that is at least partially funded with my tax dollars then I'm taking my money elsewhere! err wait... nevermind...
Well, if LoC had a website, and then MS paid them to reproduce all the functionality in Silverlight, that would be mostly fine (though it would complicate managing the website for no good reason). But the idea here seems to be to add new functionality that will only work for Microsoft's customers.
This kind of behaviour is not without precedent. For example. in some states building codes were drafted by industry associations, which were then awarded copyright in the regulations -- so you had to pay a private company in order to read mandatory state law. At least here MS isn't interfering with the content of the LoC. The real concern would start when they will announce the partnership to "digitize all of the LoC collection", of course into digital formats only readable by MS-written software.
Imagine that in order to drink these Pepsi bottles from your school, one needs a special bottle-opener which is only sold by Pepsi for $100, and that it's illegal (for good reasons) to share your bottle opener with your friends, so each of you needs to buy your own. Assume also that Coca-Cola bottles can be opened by any old bottle-opener, including bottle-openers you make yourself, and that it's perfectly legal to share bottle openers for Coca-Cola bottles. Would you still be OK with Pepsi buying off the retailer to only stock Pepsi?
Greanted, $3M is not petty cash, but surely that's the "sticker price" of the software to be installed (e.g. on the Vista kiosks), not the cost to Microsoft or the true cost after negotiations. So is LOC so cash-strapped that they can't afford to create their website without this ``donation'' ?
Just to show I'm not always cranky, here's a sedate reply. Warning: it's long. The short answer is that you can't be pulled without pulling.
Photons are affected by gravity (they follow the curvature of space caused by massive objects). But, they don't "cause" gravity, because they do not attract other objects. My understanding is that gravity is relational, which is to say, objects exert a "pull" on each other proportional to their mass. So... how can photons be pulled without also pulling? (I'm going on the assumption their pull is exactly zero, and not just infitessimally small.)
Let's start with your followup question: the curvature of space is no more a "mental model" than other objects more modern science, such as photons, DNA, or other galaxies. It is a fact in the following sense: the world around us behaves (to a great accuracy) as if it is "really" curved, there "really are" electrons and photons,
"there is" a big molecule called DNA with a double-helix structure etc. If you want, a pattern of dots on a photographic plate is a "fact". The double helix is a mental model that explains this fact. But the distinction is not useful when you're doing physics. If you accept that the goal of physics is to predict the behaviour of the world to a given accuracy, you should also accept that it is not useful to make the distinction between what the world "really is" and what it "appears to be" (for our purposes here -- not as a metaphysical question).
Next, you are confused because you are trying to use two different mental pictures of gravity at the same time, and probably don't have a good mental picture of photons. So I will analyze the situation from the points of view of both Newtonian mechanics+Special relativity and General Relativity. In Newtonian gravity, particles are affected by gravity which is an interaction between all pairs of particles. If A attracts B then B attracts A, in fact with the same magnitude of force. The interaction is proportional to the mass, so an object of "zero mass" won't interact with anything, but such an object doesn't make sense anyway (what happens to F=ma in this case?).
Now what about electromagnetic radiation? You can treat it either as a electric and magnetic fields filling space, or as composed of photons. In either case, it has momentum (do you know about light sails?) and also energy (you can be heated by sunlight!). Special relativity says (E=mc^2) that if you have energy you also have mass. You can now make a naive model in which the elecromagnetic field generates gravity according to its energy density (every small piece of space contains some elecromagentic field, this has energy and hence mass; it is a source of gravity), or you can make a model in which each photon generates gravity according to its mass. In the second case you can even calculate the effect of other masses on the photon -- the deflection you will see for a photon passing near the sum is about half what is observed in practice.
The picture above is not self-consistent. The reason is that Newtonian mechanics allows for action-at-a-distance (gravitational fields propagate at infinite speeds) which cotnradicts relativity. A better picture is that of General Relativity: the space itself is now allowed to change with time. Now there are two separate effects: first, bodies moves along the analogue of "straight lines" in a curved space; second, the curvature of space changes with time -- both under its own effect (gravitational radiation, if you want) and under the effect of the "contents" of space. The "contents" including everything in space. That includes elecromagnetic radiation -- it has mass, momentum, and can act as a source for gravity, by changing the curvature of spacetime.
I may have been very direct, but GP literally says: "To those who have 100% good physical intuition: you're wrong", and proceeds to give a technical-sounding reason. The moderators seemed to approve, since on slashdot what counts is to sound like you know what you're talking about. For me, to persume to teach others in this way (as opposed to saying "I'm not an expert, but I've heard that...") requires some degree of expertise, which this guy obviously doesn't have. That really ticked me off. And yes, while not a professional physicist I do consider myself sufficiently knowledgeable to write my reply.
I happen to be interested in legal issues, but when posting I am careful to clarify that I am not an expert when making claims about what the law is. or even what it sould be. I usually also don't claim to be so authoritative outside of mathematics, but I made a knowing exception in this case because the example was so egregious. Of course, I also failed to close an HTML tag along the way.
To those who would then say "Aha! So clearly photons do interact with gravity!", it's important to note that photons may be affected by the curvature of spactime, but they don't have mass and thus don't interact gravitationally. For instance, photons cannot attract each other gravitationally (whereas matter does), and a photon won't attract matter gravitationally.
To those don't understand physics: please stay off physics-related discussions
In fact, everything interacts gravitationally, and has a mass (more properly, contributes to the Stress-Energy tensor). Indeed, photons don't have a rest mass; however, by the famous formula $E = mc^2$, they do have mass-energy -- and this mass does interact gravitationally. It is true that, in general, the stress-energy of a single photon is small enough that it will have negligible back-reaction to the curvature of spacetime, but this is not the same as saying that the photon will have no back-reaction at all.
"color-coding" the atoms is a better description for what's going on here. Since we are pretty good at absorboing visual information, it's a good way to present it, but one should be careful not to confuse the colors in the picture with the physical process used to get the information (which has nothing to do with visible light).
Slashdot Mirror
In reality, Wikipedia is too large to have cohesive policy of this type. Rather, it is very fragmented with a large number of groups and projects, each with its own standards of quality, reliability and notability. In Mathematics, Wikipedia has become the de-facto first reference for definitions. I wouldn't use it for research results, but if you need to know what a contravariant functor is, or the basic construction of Hausdorff measure then starting at Wikipedia works. The same holds for some fields of theoretical physics. And this is perfectly compatible with there being large swathes of the encyclopedia devoted to debating the special power sof minor characters in little-known Japanese manga, written using in-universe language. The point is that most users can easily tell the difference between the two kinds of pages.
Did you read my comment? you seem to have missed the point entirely. It's true that with current LED technology, the lamp would weight tons. However, current technology is already pretty good: it converts about 10% of the incoming energy to light. A 100% efficient LED from the future will only require one-tenth the energy, but one-tenth of many tons is still about a ton. It's true that a future LED that outputs about a thousand times more light than the energy put into it would work well, but I think we can agree that writing about technology which egeegiously violates the law of conservation of energy should be thought of as science fiction, not science journalism.
For an example for the second point, remember the "gravity-powered lamp" concept that was advertized last month? I saw several independent write-ups in newspapers all repeating the canard of "this will work if only we have better LED technology" when an elementary calculation shows that even with 100% efficient lighting elements the lamp will need to weigh about a ton.
Isn't it sad that 50 years into the space program our resupply plan for the ISS is based on single-use ships?
No, it feels like there is the wrong math on Slashdot. What is needed are stories explaning accessible mathematics to a general audience. Not needed are stories about technical advances in mathematics. Two years ago there was a big hoopla about the calculation of the unitary dual of the split real form of $E_8$, which was a more important result and still completely irrelevant to the general public and impossible to explain even in the vaguest terms. There exists blogs by mathematicians where new math results are discussed. Slashdot should find stories which explain ideas of math, and report the occasional genuine breakthrough.
For CS, which is closer to the readership than Math, the bar should be lower. Deterministic poly-time primality testing was reported; a faster matrix multiplication algorithm, or even a faster factorization algorithm should be reported even if the details of the algorithm will not be reportable.
Read the paper. This is not the first S-C formula for multiply connected regions. The claimed "key result" is a formula for a case where a formula is already known. More work will be needed to a adapt the MATLAB technology from singly- and doubly-connected regions to multiply connected regions.
This paper seems to be part of ongoing work by a small community and is probably useful, but it's not a major mathematical breakthrough -- more of an incremental step. Small technical improvements in one field of mathematics shouldn't make up a slashdot story. Just because someone put "140 year old" in the press release doesn't mean it's really important. A math story belongs on /. when a big result is announced -- on the level of Poincare's Conjecture, or the Modularity Theorem.
Actually, this computation has nothing to do with the big bang. This a computation is about trying to see whether we can make sufficiently accurate (computer) calculations within QCD (our theory of quarks and elementary particles made from them) to understand particles at ordinary energy scales. This is actually quite hard (for reasons that would be hard to explain here). Making sure QCD correctly predicts the mass of the proton should come before worrying about the big bang (where physics beyond QCD will play a role anyway, and where we don't have any experimental data to compare our calculations with).
For a different perpsective, before worrying about incorporating gravity, you might want to note that this calculation only involved the 3 lightest quarks (up, down and strange), completely neglecting contributions from processes involving the other 3 quarks.
Gravity -- certainly the weakest force -- is completely irrelevant as far as the physics of elementary particles is concerned. In real life there is no way to observe any kind of gravitational interactions on the scales where the other forces are relevant. In particular, if there is physics just beyond the standard model it need not have any connection to gravity. It's true that gravity is relevant on extremely large scales, but for these scales we have perfectly good theories (GR; in fact Newtonian gravity is quite sufficient in almost all cases). You'd have to go to Planck scale before there'll be any guarantee of gravitational effects playing a role.
This is not to say that a quantum theory including gravity is not an important goal of theoretical physics, it's just to say that so far we have not found any real-life situations where such a theory would be needed, that is when corrections due to quantum gravity would play any role whatsoever. Hopefully the LHC will probe the physics beyond the standard model. The number of orders of magnitude between the energy scales we can actually observe and the quantum gravity energy scale make it extremely unlikely, however, that gravity will be relevant to experimental fundamental physics for many millenia.
I think the new offering, while cheaper, is rather inferior to the product you bought. Thoses iPhones where the same phones before and after the price reduction.
Microsoft has been using the same tactic for the OOXML meetings (remember the incident in Sweden?) I guess manipulating public meetings is the next form of business competition.
If someone offered to buy a house for me, on condition that all my friends will have to pay him rent to visit, I would be quite concerned, and might decline the offer.
Don't forget that LoC is not a private company -- it is actually charged with providing a public service. Once this spiffy public service becomes accessible only to those members of the public who first purchased a product from a specific private company (coincidentally, the one that made the "donation"), you are in serious trouble. The alternative is between having a ``free'' extra-spiffy website only accessible to Microsoft's clients, or a less-spiffy website accessible to everyone, but paid for by the LoC. It's true that the taxpayers would save money upfront were MS to build the website, but they would then have to pay the "microsoft tax" to use the website later. That is quite unfair, especially to those of us who are more comfortable with other operating systems.
The ruling says that removing a "digital watermark" triggers some DMCA sanctions: the guy embedded a digital watermark saying the image was copyrighted by him, using a particular watermarking tool. The posted images lacked the watermark. The court ruled that this meant they "removed copyright control information". I'm all for punishing copyright infringers, but note that in general there is no way to tell if a watermark has been embedded in an image or not. So, this metes out extra punishment for copyright infringement based on the rights holder embedding an undetectable booby-trap in the copyrighted work. I'm not sure I'm comfortable with that.
The donations of the kiosks don't lock up anything. But making the website depend on a media format that is not a common web standard and is furthermore specific to Microsoft risks a situation where the only way to get the full functionality of the LoC website would be to install Internet Explorer.
Imagine that in order to drink these Pepsi bottles from your school, one needs a special bottle-opener which is only sold by Pepsi for $100, and that it's illegal (for good reasons) to share your bottle opener with your friends, so each of you needs to buy your own. Assume also that Coca-Cola bottles can be opened by any old bottle-opener, including bottle-openers you make yourself, and that it's perfectly legal to share bottle openers for Coca-Cola bottles. Would you still be OK with Pepsi buying off the retailer to only stock Pepsi?
Greanted, $3M is not petty cash, but surely that's the "sticker price" of the software to be installed (e.g. on the Vista kiosks), not the cost to Microsoft or the true cost after negotiations. So is LOC so cash-strapped that they can't afford to create their website without this ``donation'' ?
Bad phrasing on my part: I should have said "to those who don't understand physics: don't presume to teach it".
Let's start with your followup question: the curvature of space is no more a "mental model" than other objects more modern science, such as photons, DNA, or other galaxies. It is a fact in the following sense: the world around us behaves (to a great accuracy) as if it is "really" curved, there "really are" electrons and photons, "there is" a big molecule called DNA with a double-helix structure etc. If you want, a pattern of dots on a photographic plate is a "fact". The double helix is a mental model that explains this fact. But the distinction is not useful when you're doing physics. If you accept that the goal of physics is to predict the behaviour of the world to a given accuracy, you should also accept that it is not useful to make the distinction between what the world "really is" and what it "appears to be" (for our purposes here -- not as a metaphysical question).
Next, you are confused because you are trying to use two different mental pictures of gravity at the same time, and probably don't have a good mental picture of photons. So I will analyze the situation from the points of view of both Newtonian mechanics+Special relativity and General Relativity. In Newtonian gravity, particles are affected by gravity which is an interaction between all pairs of particles. If A attracts B then B attracts A, in fact with the same magnitude of force. The interaction is proportional to the mass, so an object of "zero mass" won't interact with anything, but such an object doesn't make sense anyway (what happens to F=ma in this case?).
Now what about electromagnetic radiation? You can treat it either as a electric and magnetic fields filling space, or as composed of photons. In either case, it has momentum (do you know about light sails?) and also energy (you can be heated by sunlight!). Special relativity says (E=mc^2) that if you have energy you also have mass. You can now make a naive model in which the elecromagnetic field generates gravity according to its energy density (every small piece of space contains some elecromagentic field, this has energy and hence mass; it is a source of gravity), or you can make a model in which each photon generates gravity according to its mass. In the second case you can even calculate the effect of other masses on the photon -- the deflection you will see for a photon passing near the sum is about half what is observed in practice.
The picture above is not self-consistent. The reason is that Newtonian mechanics allows for action-at-a-distance (gravitational fields propagate at infinite speeds) which cotnradicts relativity. A better picture is that of General Relativity: the space itself is now allowed to change with time. Now there are two separate effects: first, bodies moves along the analogue of "straight lines" in a curved space; second, the curvature of space changes with time -- both under its own effect (gravitational radiation, if you want) and under the effect of the "contents" of space. The "contents" including everything in space. That includes elecromagnetic radiation -- it has mass, momentum, and can act as a source for gravity, by changing the curvature of spacetime.
Part o
I may have been very direct, but GP literally says: "To those who have 100% good physical intuition: you're wrong", and proceeds to give a technical-sounding reason. The moderators seemed to approve, since on slashdot what counts is to sound like you know what you're talking about. For me, to persume to teach others in this way (as opposed to saying "I'm not an expert, but I've heard that ...") requires some degree of expertise, which this guy obviously doesn't have. That really ticked me off. And yes, while not a professional physicist I do consider myself sufficiently knowledgeable to write my reply.
I happen to be interested in legal issues, but when posting I am careful to clarify that I am not an expert when making claims about what the law is. or even what it sould be. I usually also don't claim to be so authoritative outside of mathematics, but I made a knowing exception in this case because the example was so egregious. Of course, I also failed to close an HTML tag along the way.
Are you under the impression I was referring to the photographic process? If so, follow the link.
Perhaps you were thinking of Technicolor ?
"color-coding" the atoms is a better description for what's going on here. Since we are pretty good at absorboing visual information, it's a good way to present it, but one should be careful not to confuse the colors in the picture with the physical process used to get the information (which has nothing to do with visible light).