Why do you think ebook prices are artificially high? Amazon's pricing is perniciously low: they intentionally undercut other retailers, accepting real losses in the short-term to gain market advantage. This convinces consumers that the market value of an ebook is lower than the real production costs. All the services that go into making a book are still required: editing, design, PR, etc. These things cost money. Except now, with Amazon forcing prices (ebook and otherwise) to artificial lows, the publishers can't afford to pay the employees that used to be responsible for those aspects of producing a book. Your "artificially high" prices have put lots of people out of a job. (I mean that literally. Publishers farm out their copyediting to freelancers now, instead of doing it in-house. And most books receive a fraction of the editing they used to get.)
A common argument goes like this: "It's an ebook! It costs so much less to make! None of the costs are there! No warehouses! You don't have to pay for paper!" You could call that specious, but it'd be more honest to call it stupid. (I am not accusing any particular person in this thread of making that argument.) Does an ebook need to cost as much as a hardcover? No. But while $25 is too high, the $8-$10 range is definitely too low. Unless, that is, you favor a market with one or two distributors and one or two large publishers. And hundreds of thousands of self-published authors, of course, all fighting for spots on Amazon's Kindle charts. Have you read many self-published authors? Think of how hard it is to slog through the comments for a typical Slashdot article. How many do you read before you find one that seems worthwhile? Can you imagine doing that -- times a hundred -- just to find a book to read?
P.S. I'm sure that Amazon will keep their prices this low once they have all the market share. You can totally trust them.
Web server meltdown in 3....2.....1..... It's working fine here. Then again, I'm sitting in an office at the Perimeter Institute, so that may explain some of it.
I'll admit to keeping a Win partition on my machine, so that from time to time I could boot into XP and play with apps like iTunes. I was pretty taken with iTunes at first, but the only thing it seems to offer over any collection of similar Linux apps is convenience. Why not use apps like rhythmbox (for gnome) or juk (for kde)? While neither app is as mature as iTunes (yet), they both do a great job. And both have better.ogg support than iTunes.
I would argue that ITMS, while convenient, isn't that great a value. Why not opt for one of the other services that lets you download files encoded at a higher bitrate? Or in multiple formats? Or from Linux? This is exactly the kind of application where Linux users should be looking to innovate, in the interest of offering more choices, and not just waiting for the CrossOver port. There are plenty of great projects out there doing just that, and they could all use the attention that CrossOver's iTunes work seems to be getting.
Yes. You're missing 200 years of Black Hole history.
The notion of a body whose gravitational force is so strong that not even light can escape was put forward in the late 1700s, first by a British geologist and later by Pierre Laplace. The solution of General Relativity that would come to be recognized as a Black Hole was put forward by Karl Schwarzschild in 1915, only a short time after Einstein had presented his theory of General Relativity. Schwarzschild developed his solution while serving with the German army, on the Russian front. Chandrasekhar's work was initiated in the 1920s. The idea of "Frozen Stars" remained known to physicists, but wasn't the focus of as much attention as it is nowadays. It wasn't until the late 60s and early 70s that they began to attract more attention, and around that time the phrase "Black Hole" appeared.
A great deal of Hawking's work has been devoted to Black Holes, and he is responsible for a number of significant developments in our understanding of them. In fact, "significant development" doesn't quite do it credit, as some of his ideas were so counter-intuitive (the notion of Black Holes radiating, for one!) as to be totally unexpected. But he definitely did not invent the concept of a Black Hole!
The folks at Los Alamos (Mottola et al.) who dreamt this up were trying to devise a scheme in which gravitational collapse led to an object similar to, but without what some perceive to be the inconsistencies of, a Black Hole. While they get points for trying, there are a lot of problems with their proposed model.
First, it requires that under extreme situations gravity undergoes a "phase change", which for all intents and purposes means that the region inside the gravastar posseses a positive cosmological constant, effectively a non-zero energy density inherent to space itself. The notion of a cosmological constant has been troubling relativists and particle theorists for over 70 years and we still don't understand whether there is such a thing and where it might come from. Current astronomical observations suggest that there may in fact be a very small CC, but no one knows a mechanism for how this might be "produced" inside a gravastar. The earlier work of the Los Alamos crew makes some suggestions for how this might come about, but is itself based on a field theoretic treatment of gravity, a pretty shaky proposal whose predictions are hard to identify and must be taken with a grain of salt.
Second, they propose an interface layer between their "gravitational BEC" and the world outside the gravastar, made up of "ultra-stiff fluid". In GR we often resort to desribing distributions of gravitating energy and matter as a perfect fluid with an equation of state that relates how much energy density there is to how hard it pushes out, or its pressure. There is a "stiffest possible" equation of state consistent with causality (the speed of sound of disturbances in the fluid is equal to the speed of light). This is what they use to make their interface. Such a fluid has fascinating properties and is the subject of a lot of attention right now, but no one really knows of any such substance or what its microscopic physics might be. Therefore a lot of guesswork goes into any numerical estimates they might suggest.
Third, their gravastars are extremely cold and don't seem as if they would be useful for the types of processes that astrophysicists typically invoke Black Holes to explain. Black Holes are conjectured to be responsible for a wide array of highly energetic processes that we see in the Universe, and these gravastars just don't seem as if they would even be stable in such situations.
Last, if you go to http://arXiv.org and search for this paper, you will see that it has been revised five times since it was originally submitted. It isn't unusual for papers to be revised, even that many times, but I know that some of the revisions are due to calculational errors.
The paper is entertaining and has some neat ideas, but is in all likelihood not the way things are. There is a movement among some condensed matter physicists who claim that the principles of CM physics are actually fundamental and should form the basis for any consistent model of gravity and particle physics. This paper is a nod in that direction. While some ideas from CM might find fruitful application in high energy physics, it doesn't seem likely that phenomena at the Planck scale (where quantum gravitational effects become important) will benefit from them.
Just to clarify, what's being talked about here is not what physicists usually refer to as 'quantum gravity'. Quantum gravitational effects are relevant at *extremely* large energies, much larger than the energy scales that characterize the processes that we associate with typical particle physics phenomena. It is very unlikely that we will learn much of anything about quantum gravity by looking at such low energy processes as the ones described in this story. There are some scenarios that bring down the scale that characterize quantum gravity to something on the order of TeV, but those are speculative.
Furthermore, learning about quantum gravity *does not* mean that we toss General Relativity. Regardless of what kind of physics goes on at the Planck scale, GR is absurdly accurate over a tremendous range of energies, much more so than we have any right to expect. For instance, even if we develop a consistent theory of Quantum Gravity you'd never use it to explain how the orbit of Mercury differs from the predictions of Newtonian
celestial mechanics, GR does this with as much precision as we'll ever be able to measure.
The results of the experiment in this story, while they may have to do with quantum mechanics in an external gravitational potential, are not the result of quantum gravity effects.
There's a comment in the main post about the Higgs "coupling with mass". The Higgs Boson doesn't couple to mass, rather, it gives a mass to fermions through a coupling of the form HYY, where H is the Higgs and Y are fermions. When the Higgs has a non-zero expectation value this effectively looks like the fermions have a mass term.
Also, it's not quite right to say that the measurements of the muon anomalous magnetic moment are out of line with Standard Model predictions. I'd love it if these experiments are in fact showing us indicators of physics beyond the Standard Model, but there are a lot of factors that go into calculating g-2, any one of which might explain the recently observed value.
Slashdot Mirror
Why do you think ebook prices are artificially high? Amazon's pricing is perniciously low: they intentionally undercut other retailers, accepting real losses in the short-term to gain market advantage. This convinces consumers that the market value of an ebook is lower than the real production costs. All the services that go into making a book are still required: editing, design, PR, etc. These things cost money. Except now, with Amazon forcing prices (ebook and otherwise) to artificial lows, the publishers can't afford to pay the employees that used to be responsible for those aspects of producing a book. Your "artificially high" prices have put lots of people out of a job. (I mean that literally. Publishers farm out their copyediting to freelancers now, instead of doing it in-house. And most books receive a fraction of the editing they used to get.)
A common argument goes like this: "It's an ebook! It costs so much less to make! None of the costs are there! No warehouses! You don't have to pay for paper!" You could call that specious, but it'd be more honest to call it stupid. (I am not accusing any particular person in this thread of making that argument.) Does an ebook need to cost as much as a hardcover? No. But while $25 is too high, the $8-$10 range is definitely too low. Unless, that is, you favor a market with one or two distributors and one or two large publishers. And hundreds of thousands of self-published authors, of course, all fighting for spots on Amazon's Kindle charts. Have you read many self-published authors? Think of how hard it is to slog through the comments for a typical Slashdot article. How many do you read before you find one that seems worthwhile? Can you imagine doing that -- times a hundred -- just to find a book to read?
P.S. I'm sure that Amazon will keep their prices this low once they have all the market share. You can totally trust them.
I'll admit to keeping a Win partition on my machine, so that from time to time I could boot into XP and play with apps like iTunes. I was pretty taken with iTunes at first, but the only thing it seems to offer over any collection of similar Linux apps is convenience. Why not use apps like rhythmbox (for gnome) or juk (for kde)? While neither app is as mature as iTunes (yet), they both do a great job. And both have better .ogg support than iTunes.
I would argue that ITMS, while convenient, isn't that great a value. Why not opt for one of the other services that lets you download files encoded at a higher bitrate? Or in multiple formats? Or from Linux? This is exactly the kind of application where Linux users should be looking to innovate, in the interest of offering more choices, and not just waiting for the CrossOver port. There are plenty of great projects out there doing just that, and they could all use the attention that CrossOver's iTunes work seems to be getting.
Yes. You're missing 200 years of Black Hole history.
The notion of a body whose gravitational force is so strong that not even light can escape was put forward in the late 1700s, first by a British geologist and later by Pierre Laplace. The solution of General Relativity that would come to be recognized as a Black Hole was put forward by Karl Schwarzschild in 1915, only a short time after Einstein had presented his theory of General Relativity. Schwarzschild developed his solution while serving with the German army, on the Russian front. Chandrasekhar's work was initiated in the 1920s. The idea of "Frozen Stars" remained known to physicists, but wasn't the focus of as much attention as it is nowadays. It wasn't until the late 60s and early 70s that they began to attract more attention, and around that time the phrase "Black Hole" appeared.
A great deal of Hawking's work has been devoted to Black Holes, and he is responsible for a number of significant developments in our understanding of them. In fact, "significant development" doesn't quite do it credit, as some of his ideas were so counter-intuitive (the notion of Black Holes radiating, for one!) as to be totally unexpected. But he definitely did not invent the concept of a Black Hole!
m5brane
The folks at Los Alamos (Mottola et al.) who dreamt this up were trying to devise a scheme in which gravitational collapse led to an object similar to, but without what some perceive to be the inconsistencies of, a Black Hole. While they get points for trying, there are a lot of problems with their proposed model.
First, it requires that under extreme situations gravity undergoes a "phase change", which for all intents and purposes means that the region inside the gravastar posseses a positive cosmological constant, effectively a non-zero energy density inherent to space itself. The notion of a cosmological constant has been troubling relativists and particle theorists for over 70 years and we still don't understand whether there is such a thing and where it might come from. Current astronomical observations suggest that there may in fact be a very small CC, but no one knows a mechanism for how this might be "produced" inside a gravastar. The earlier work of the Los Alamos crew makes some suggestions for how this might come about, but is itself based on a field theoretic treatment of gravity, a pretty shaky proposal whose predictions are hard to identify and must be taken with a grain of salt.
Second, they propose an interface layer between their "gravitational BEC" and the world outside the gravastar, made up of "ultra-stiff fluid". In GR we often resort to desribing distributions of gravitating energy and matter as a perfect fluid with an equation of state that relates how much energy density there is to how hard it pushes out, or its pressure. There is a "stiffest possible" equation of state consistent with causality (the speed of sound of disturbances in the fluid is equal to the speed of light). This is what they use to make their interface. Such a fluid has fascinating properties and is the subject of a lot of attention right now, but no one really knows of any such substance or what its microscopic physics might be. Therefore a lot of guesswork goes into any numerical estimates they might suggest.
Third, their gravastars are extremely cold and don't seem as if they would be useful for the types of processes that astrophysicists typically invoke Black Holes to explain. Black Holes are conjectured to be responsible for a wide array of highly energetic processes that we see in the Universe, and these gravastars just don't seem as if they would even be stable in such situations.
Last, if you go to http://arXiv.org and search for this paper, you will see that it has been revised five times since it was originally submitted. It isn't unusual for papers to be revised, even that many times, but I know that some of the revisions are due to calculational errors.
The paper is entertaining and has some neat ideas, but is in all likelihood not the way things are. There is a movement among some condensed matter physicists who claim that the principles of CM physics are actually fundamental and should form the basis for any consistent model of gravity and particle physics. This paper is a nod in that direction. While some ideas from CM might find fruitful application in high energy physics, it doesn't seem likely that phenomena at the Planck scale (where quantum gravitational effects become important) will benefit from them.
Just to clarify, what's being talked about here is not what physicists usually refer to as 'quantum gravity'. Quantum gravitational effects are relevant at *extremely* large energies, much larger than the energy scales that characterize the processes that we associate with typical particle physics phenomena. It is very unlikely that we will learn much of anything about quantum gravity by looking at such low energy processes as the ones described in this story. There are some scenarios that bring down the scale that characterize quantum gravity to something on the order of TeV, but those are speculative.
Furthermore, learning about quantum gravity *does not* mean that we toss General Relativity. Regardless of what kind of physics goes on at the Planck scale, GR is absurdly accurate over a tremendous range of energies, much more so than we have any right to expect. For instance, even if we develop a consistent theory of Quantum Gravity you'd never use it to explain how the orbit of Mercury differs from the predictions of Newtonian
celestial mechanics, GR does this with as much precision as we'll ever be able to measure.
The results of the experiment in this story, while they may have to do with quantum mechanics in an external gravitational potential, are not the result of quantum gravity effects.
There's a comment in the main post about the Higgs "coupling with mass". The Higgs Boson doesn't couple to mass, rather, it gives a mass to fermions through a coupling of the form HYY, where H is the Higgs and Y are fermions. When the Higgs has a non-zero expectation value this effectively looks like the fermions have a mass term. Also, it's not quite right to say that the measurements of the muon anomalous magnetic moment are out of line with Standard Model predictions. I'd love it if these experiments are in fact showing us indicators of physics beyond the Standard Model, but there are a lot of factors that go into calculating g-2, any one of which might explain the recently observed value.