Nanotubes' 20 K critical temperature (T_c) does not come close to a high temperature superconductor.
High T_c is usually defined as above the boiling point of liquid nitrogen, a good, cheap, plentiful, environmentally-friendly coolant, which is 77 K. This implies that liquid nitrogen can be used to keep the material superconducting, a property which drops costs and engineering challenges dramatically.
Nanotubes' more popular and practical properties are its tensile strength (i.e. space elevator), and its *thermal* superconductivity (i.e. badass heatsink).
Furthermore, it's ideal for high-power electrical transformer applications because it conducts electricity with low resistance in only one dimension, eliminating pesky, dissipative eddy currents. A friend of mine patented this application.
It's because none of those "high-budget science projects" consider themselves highly budgeted. Those that win grants with a lot of money have a lot to accomplish with that money.
For each programmer they hire to work on modernizing Fortran, how many grad students and postdocs do they not hire due to funding constraints? Who is willing to lose that much science for their group? Not many.
It doesn't mean they *shouldn't* put money into Fortran, just that I'd be very surprised if they did. I'm sure I myself will be guilty of exactly that when I reach the ranks of the professoriate.
While there is a certain, tiny fraction of the population who is bright enough and self-motivated enough to pore over all the coursework that is equivalent to a degree, they are certainly very far from the norm. That is to say, Joe Blow will never know as much as an MIT grad. Only the most elite of the motivated might ever hope to, and I assert they would still get more out of actually attending a good university. Working alongside the best, brightest, and most hardworking is absolutely invaluable.
If the degrees of MIT ever lose value, it will not be from OCW.
Also note that a significant percentage of the CMU population, at least undergrad, is comprised of MIT rejects. Then again, CMU is good enough that those who still want MIT/Stanford/Berkeley can often go for grad school.
No, just that fusion is NOT the key to (nearly) free energy and that (nearly) free energy wouldn't necessarily enable the great wondners of space travel that everyone envisions. The humble power transformer has not changed substantially in the past 50-100 years. Heat management is a huge issue nowadays, as all overclockers have noted.
Also brought up is that propulsion systems don't really know what to do with that much power. I'm not entirely sure ion drives would scale up that well, although I could be surprised.
Fusion won't solve all the world's problems, certainly, but I think it would help.
Assuming you have a legal license and key to Windows XP ($10 at a university bookstore), along with a working internet connection, Activation is a one- or two-click process. Perhaps because my connection is so fast, the lag between that menu and the next was not perceptably different than the lag between any other two menus.
Total time stolen from me by the Evil Empire: 2 seconds. I'm sure raging now.
It's certainly a lot less time than is required to, say, recompile my kernel to support the new hardware I've bought.
This is a legitimate point, which is incredible for a first post.
Anyhow, it seemed that free dialup failed because it was a) too slow, and b) had way too many ads. I suspect this will be more successful, as these aren't such a problem.
Re: poor people not having computers. Often there are families who recognize that they should hop onto the technology bandwagon, for themselves or for the sake of their children. What prevents many of them from investing in technology is the monthly fee of a net connection, not so much the initial cost of the computer.
Unfortunately, these poor people will probably pay the windows tax since they don't have the kind of computer experience and education to use linux, which would ironically be much more enabling to them.
Of course, we will always have to balance between supporting legacy apps and the increased productivity of innovation. If you want to see changes put into effect, though, put your money where your mouth is when you next see a keyboard layout that really cries out to you. Then post a review to slashdot..;-) Geeks have a lot of buying power collectively.
----
That which does not kill me makes me stronger;
That which does kill me I'll deal with when I respawn.
I never implied that the evolution was not impressive, but it was evolution nonetheless. The original atomic bomb harnessed a new physics, pioneered by the most brilliant minds on the planet. That is what I mean by revolution.
I say the human species was threatened with the original a-bomb. Improvement upon the concept took only lesser minds to accomplish.
I must voice my disagreement. I don't feel that Rhodes captured the same excitement of fundamentally world-changing events. The first atomic bomb was revolution. Subsequent advances in power constituted evolution.
As to the German program, it was certainly fascinating, but got coverage in both The Making of the Atomic Bomb and in Copenhagen. Essential reading for people interested in the atomic bomb or physics. Oh, and Surely You're Joking, Mr. Feynman was indeed most excellent. It is a genuinely entertaining look into the mind of a great modern genius.
----
So a bar walks into a physicist -- oops! wrong reference frame.
Anyhow, my only reply is that science doesn't presume to have any knowledge of what happens outside the universe as we know it. Before the Big Bang is generally considered off-limits. Science doesn't not necessarily preclude the existence of God.
What logic has proved is that God, in the Christian sense, can neither be proved nor disproved. Anyone who's taken a basic course in philosophy should know that. It was established a very long time ago that metaphysics is beyond the conditions for the possibility of knowing.
I would like to recall to your attention that it only counts as science if it matches the available data, verifications are repeatable, and it has some predictive value. Models such as the Big Bang count as good science because they explain so much of what we observe when we look through our telescopes. It explains why we have the chemical compositions we do. It's accounted for everything just fine, even before we thought to include those details in the model. It doesn't (yet) deign to give meaning to existence or to posit what existed before. If science ever ventured a suggestion as to what came before, there would have to be predictive value and a way of verifying the facts before anyone would take it seriously. If I claim the universe came from a bubble in a carbonated beverage, no one can present evidence to the contrary, but nor can I point to anything that lends me credence. Furthermore, I predict nothing. This is somewhat the same state as metaphysics; lots of claims are made that could work, but truly provide no reason to believe one way over the other than simple aesthetic value. Sometimes a belief just appeals to you. Read philosophy for more on that.
So there is controversy with the concept of singularity exactly because of the quantization of spacetime. While you could have infinitesimal volume in classical space, in our modern understanding, you can't really talk about anything before around 10^-43 seconds, the Planck time. At this time, the universe was on the order of Planck length, which means that it's very hard to define any meaningful parameters. Probing back to these initial conditions is something that's being studied now. We're pretty sure about some stuff, and are just speculating about other stuff.
We don't actually need mass in this universe; photons have energy, but no mass. If all the anti-matter and matter had annihilated symmetrically, the universe would be filled with pure energy and no matter, but somewhere, symmetry was broken (which is yet another topic). My point is that you stop talking about mass or energy after a point, and talk about mass-energy or stress-energy. In general relativity, you learn that pretty much everything in the universe is determined by geometry, and this geometry is determined by the distribution of stress-energy, that is, the mass of particles, their associated energies, and the energy of fields such as electromagnetic and gravitational.
Re: Heat and information. As far as I know, there is no information in a singularity, including a characterization of heat. I've not studied any cosmology past what's fallen into the rest my physics curriculum and the stray popular-science book.
As to why the big bang took place, your guess is as good as mine. In exploring the why/how, we run into theories like the Infinite Universe theories (there are quite a few interesting variations) and more classical ideas such as Creationism. Science doesn't have an answer for that one yet, though I note that philosophy has proven that you can neither prove nor disprove the existence of the Christian God.
Ignoring that we don't know why/how the universe started, we do have lots of good, testable theories about how it subsequently evolved into its present state. Inflationary theory is a good place to start reading, as is the anisotropy of the cosmic microwave radiation. My research currently is on the early universe's phase transition between quark-gluon plasma and hadron gas. The superstructure and formation of galaxies is an active area right now with lots of excitement as things fall into place.
The current universe doesn't have an infinite amount of anything, but when you compress everything to a single point, you have what we call a "singularity". A finite quantity of energy in an infinitesimal volume is infinite density. Note that there is no mention of "infinite energy" or "infinite mass", which as we all know is the same thing anyway.
Temperature is difficult to define at a such a scale, but you better believe it was nice and toasty.
Also, the idea of a singularity did not come from our "Einstein brothers", but has been around since Hubble's time, I believe, when he discovered unambiguously that the universe was expanding more or less uniformly. Logical extrapolation backwards indicates that at one point, everything was on top of each other -- our singularity.
Now there's the idea of Inflation (well-accepted theory by Alan Guth, of MIT) to deal with, but that's a story for another post.
Perhaps it is because I belong to the Physics Establishment, but it seems like early hype. I do not have a subscription to Nature, but I'm sure the results are preliminary and have error bars larger than the effect itself.
While such an fundamental upset is certainly possible, I will hold my reservations until the data has been pored over by these physicists' peers and their experiment repeated with greater precision.
The ramifications of varying speed of light theories are quite significant, and most of them tend to break physics. Take everything with a grain of salt.
--- This sig was generated by a Barrel of Attack Ninjas for WallsRSolid (591098).
Slashdot Mirror
Nanotubes' 20 K critical temperature (T_c) does not come close to a high temperature superconductor.
High T_c is usually defined as above the boiling point of liquid nitrogen, a good, cheap, plentiful, environmentally-friendly coolant, which is 77 K. This implies that liquid nitrogen can be used to keep the material superconducting, a property which drops costs and engineering challenges dramatically. Nanotubes' more popular and practical properties are its tensile strength (i.e. space elevator), and its *thermal* superconductivity (i.e. badass heatsink).
Furthermore, it's ideal for high-power electrical transformer applications because it conducts electricity with low resistance in only one dimension, eliminating pesky, dissipative eddy currents. A friend of mine patented this application.
----
e+ ---> <--- e-
Fatal Attraction
It's because none of those "high-budget science projects" consider themselves highly budgeted. Those that win grants with a lot of money have a lot to accomplish with that money.
For each programmer they hire to work on modernizing Fortran, how many grad students and postdocs do they not hire due to funding constraints? Who is willing to lose that much science for their group? Not many.
It doesn't mean they *shouldn't* put money into Fortran, just that I'd be very surprised if they did. I'm sure I myself will be guilty of exactly that when I reach the ranks of the professoriate.
I cannot disagree with your main thrust more.
While there is a certain, tiny fraction of the population who is bright enough and self-motivated enough to pore over all the coursework that is equivalent to a degree, they are certainly very far from the norm. That is to say, Joe Blow will never know as much as an MIT grad. Only the most elite of the motivated might ever hope to, and I assert they would still get more out of actually attending a good university. Working alongside the best, brightest, and most hardworking is absolutely invaluable.
If the degrees of MIT ever lose value, it will not be from OCW.
CMU Classic Quotes:
"Sex kills. Come to CMU and live forever."
"Work, sleep, food, friends - pick any three."
Also note that a significant percentage of the CMU population, at least undergrad, is comprised of MIT rejects. Then again, CMU is good enough that those who still want MIT/Stanford/Berkeley can often go for grad school.
e+ ---> <--- e-
Fatal Attraction
No, just that fusion is NOT the key to (nearly) free energy and that (nearly) free energy wouldn't necessarily enable the great wondners of space travel that everyone envisions. The humble power transformer has not changed substantially in the past 50-100 years. Heat management is a huge issue nowadays, as all overclockers have noted.
Also brought up is that propulsion systems don't really know what to do with that much power. I'm not entirely sure ion drives would scale up that well, although I could be surprised.
Fusion won't solve all the world's problems, certainly, but I think it would help.
e+ ---> <--- e-
Fatal Attraction
Assuming you have a legal license and key to Windows XP ($10 at a university bookstore), along with a working internet connection, Activation is a one- or two-click process. Perhaps because my connection is so fast, the lag between that menu and the next was not perceptably different than the lag between any other two menus.
Total time stolen from me by the Evil Empire: 2 seconds. I'm sure raging now.
It's certainly a lot less time than is required to, say, recompile my kernel to support the new hardware I've bought.
e+----> <----e-
Fatal Attraction
This is a legitimate point, which is incredible for a first post.
Anyhow, it seemed that free dialup failed because it was a) too slow, and b) had way too many ads. I suspect this will be more successful, as these aren't such a problem.
Re: poor people not having computers. Often there are families who recognize that they should hop onto the technology bandwagon, for themselves or for the sake of their children. What prevents many of them from investing in technology is the monthly fee of a net connection, not so much the initial cost of the computer.
Unfortunately, these poor people will probably pay the windows tax since they don't have the kind of computer experience and education to use linux, which would ironically be much more enabling to them.
----
e+ ----><---- e-
Fatal Attraction
Of course, we will always have to balance between supporting legacy apps and the increased productivity of innovation. If you want to see changes put into effect, though, put your money where your mouth is when you next see a keyboard layout that really cries out to you. Then post a review to slashdot.. ;-) Geeks have a lot of buying power collectively.
----
That which does not kill me makes me stronger;
That which does kill me I'll deal with when I respawn.
I never implied that the evolution was not impressive, but it was evolution nonetheless. The original atomic bomb harnessed a new physics, pioneered by the most brilliant minds on the planet. That is what I mean by revolution.
I say the human species was threatened with the original a-bomb. Improvement upon the concept took only lesser minds to accomplish.
----
e+ ----><---- e-
Fatal Attraction
I must voice my disagreement. I don't feel that Rhodes captured the same excitement of fundamentally world-changing events. The first atomic bomb was revolution. Subsequent advances in power constituted evolution.
As to the German program, it was certainly fascinating, but got coverage in both The Making of the Atomic Bomb and in Copenhagen. Essential reading for people interested in the atomic bomb or physics. Oh, and Surely You're Joking, Mr. Feynman was indeed most excellent. It is a genuinely entertaining look into the mind of a great modern genius.
----
So a bar walks into a physicist -- oops! wrong reference frame.
Wonder if anyone is still reading this thread...
Anyhow, my only reply is that science doesn't presume to have any knowledge of what happens outside the universe as we know it. Before the Big Bang is generally considered off-limits. Science doesn't not necessarily preclude the existence of God.
What logic has proved is that God, in the Christian sense, can neither be proved nor disproved. Anyone who's taken a basic course in philosophy should know that. It was established a very long time ago that metaphysics is beyond the conditions for the possibility of knowing.
I would like to recall to your attention that it only counts as science if it matches the available data, verifications are repeatable, and it has some predictive value. Models such as the Big Bang count as good science because they explain so much of what we observe when we look through our telescopes. It explains why we have the chemical compositions we do. It's accounted for everything just fine, even before we thought to include those details in the model. It doesn't (yet) deign to give meaning to existence or to posit what existed before. If science ever ventured a suggestion as to what came before, there would have to be predictive value and a way of verifying the facts before anyone would take it seriously. If I claim the universe came from a bubble in a carbonated beverage, no one can present evidence to the contrary, but nor can I point to anything that lends me credence. Furthermore, I predict nothing. This is somewhat the same state as metaphysics; lots of claims are made that could work, but truly provide no reason to believe one way over the other than simple aesthetic value. Sometimes a belief just appeals to you. Read philosophy for more on that.
So there is controversy with the concept of singularity exactly because of the quantization of spacetime. While you could have infinitesimal volume in classical space, in our modern understanding, you can't really talk about anything before around 10^-43 seconds, the Planck time. At this time, the universe was on the order of Planck length, which means that it's very hard to define any meaningful parameters. Probing back to these initial conditions is something that's being studied now. We're pretty sure about some stuff, and are just speculating about other stuff.
We don't actually need mass in this universe; photons have energy, but no mass. If all the anti-matter and matter had annihilated symmetrically, the universe would be filled with pure energy and no matter, but somewhere, symmetry was broken (which is yet another topic). My point is that you stop talking about mass or energy after a point, and talk about mass-energy or stress-energy. In general relativity, you learn that pretty much everything in the universe is determined by geometry, and this geometry is determined by the distribution of stress-energy, that is, the mass of particles, their associated energies, and the energy of fields such as electromagnetic and gravitational.
Re: Heat and information. As far as I know, there is no information in a singularity, including a characterization of heat. I've not studied any cosmology past what's fallen into the rest my physics curriculum and the stray popular-science book.
As to why the big bang took place, your guess is as good as mine. In exploring the why/how, we run into theories like the Infinite Universe theories (there are quite a few interesting variations) and more classical ideas such as Creationism. Science doesn't have an answer for that one yet, though I note that philosophy has proven that you can neither prove nor disprove the existence of the Christian God.
Ignoring that we don't know why/how the universe started, we do have lots of good, testable theories about how it subsequently evolved into its present state. Inflationary theory is a good place to start reading, as is the anisotropy of the cosmic microwave radiation. My research currently is on the early universe's phase transition between quark-gluon plasma and hadron gas. The superstructure and formation of galaxies is an active area right now with lots of excitement as things fall into place.
The current universe doesn't have an infinite amount of anything, but when you compress everything to a single point, you have what we call a "singularity". A finite quantity of energy in an infinitesimal volume is infinite density. Note that there is no mention of "infinite energy" or "infinite mass", which as we all know is the same thing anyway.
Temperature is difficult to define at a such a scale, but you better believe it was nice and toasty.
Also, the idea of a singularity did not come from our "Einstein brothers", but has been around since Hubble's time, I believe, when he discovered unambiguously that the universe was expanding more or less uniformly. Logical extrapolation backwards indicates that at one point, everything was on top of each other -- our singularity.
Now there's the idea of Inflation (well-accepted theory by Alan Guth, of MIT) to deal with, but that's a story for another post.
Hope that helps.
e+ ------> <------ e-
Fatal Attraction
Perhaps it is because I belong to the Physics Establishment, but it seems like early hype. I do not have a subscription to Nature, but I'm sure the results are preliminary and have error bars larger than the effect itself.
While such an fundamental upset is certainly possible, I will hold my reservations until the data has been pored over by these physicists' peers and their experiment repeated with greater precision.
The ramifications of varying speed of light theories are quite significant, and most of them tend to break physics. Take everything with a grain of salt.
---
This sig was generated by a Barrel of Attack Ninjas for WallsRSolid (591098).