Specifically in the case of the FTL laser pulses, there are two points to keep track of. One is the location of the peak in amplitude, and the other is the location of the leading edge of the pulse.
As the pulse propagates, it changes shape. It is passing through a dispersive medium. The result of the shape change is that the peak in amplitude moves faster than c while the leading edge does not.
If allowed to propagate far enough, the peak would catch up to the leading edge. This might be equivalent to a shock front in a fluid. In any case, the dynamics of the propagation would change, and the peak would stop propagating faster than c.
Code written before the job was owned by whatsisname. The copyright to this code can only be transferred by a written document. (SCO v. Novell, folks.) The company needs to find a document that specifically says that Daimaou is transferring copyright of that code to them. It sounds like the agreement could create an obligation to transfer rights to the code, but the agreement does not itself make the transfer. So Daimaou owns the copyrights to his old code.
It is debatable what rights he gave to his company by bringing the code "in the door", but automatic transfer of copyrights is not one of them. Though establishing his ownership could be hard if he doesn't have a very good record of what he produced before being hired.
Code written for work after the start of the job probably never belonged to him in the first place, so there is no issue of transfer.
Did you do any research into the relative amounts of energy used in constructing different washers? Think of a $1k front loader vs. a $400 top loader. That extra $600 either (1) is pure profit margin, or (2) pays for more complicated construction. (1) is unlikely in a competative market. (2) means it is likely more energy is used constructing the fancy washer.
"it's a great index of stuff to have a look at on public websites."
I for one would like to know why the robots.txt at www.whitehouse.gov is blocking access to directories like/kids/teeball/iraq. Is there some national security implication that I am missing? Or/national-anthem/text. Can't allow people to get the words to the national anthem! Who knows what fool ideas they'll come up with.
"A few clicks later, i realized i was actually on an internet site. putting my personal banking information that close to the internet without me being clearly aware of any delineation made me nervous."
Is it any wonder people are jittery about using MS software? I have two computers that double boot into Linux and MS Windows. I will boot into MS Windows when I really need to, for example someone sent me a MS Word file that OpenOffice can't understand or I am watching a DVD with features that ogle can't deal with. But I never dial up to an ISP or connect to a local network under MS Windows. I don't want to let them try to "phone home" to Redmond. I don't know what they might try to send, but whatever it is, it is none of MS's business.
Posted from a machine that dual boots Redhat Linux 9 and Microsoft Windows 95.
"Nah, only ideal blocks, ideal balls, and ideal disks can do that. Real ones are never perfectly symmetric...sooner or later, everything macroscopic and rigid will precess and/or tumble."
Nah. A three-dimensional rigid object with no exact symmetry has three axes around which it can rotate forever without precessing. The reason that any physical object will precess is that the rotation will never be exactly about one of the axes. The axes nevertheless still exist.
Rotation is not "stable" around any of the three axes. "Stable" would mean that any perturbation to the angular momentum would eventually damp out and the object would return to rotation about the axis. This does not happen for rigid bodies.
Furthermore, the object doesn't "eventually" precess. The rate of precession is constant after the spin is imparted to the object.
Now things will be different if you want to put your object in an atmosphere that damps the rotation or imparts a net force, let it vibrate or otherwise absorb energy or not move as a rigid body (flywheel seizes up), or have the gravitational field or some other force change with time. But this has nothing to do with the moments of inertia and axis of rotation.
If we put up a cylindrical satellite spinning around a principal axis (e.g. the one which is almost the theoretical axis of the cylinder), it will not stay that way forever. This is not due to any asymmetries or imperfections. It is because the interaction with the wisps of atmosphere and the various change gravitational fields will exert torques on it which change the axis of rotation.
"Those are the only two axes around which you can spin the object and have it stay stable."
Not quite. An object like a rectangular block of wood can be spun around any of three axes (the obvious one). A ball can be spun around any axis. A disk can be spun around the axis normal to the surface or any axis parallel to the surface.
I have moment-of-inertia tensors spinning in my head...
"But now you have to show the teapot and how and where you obtained it."
If the poster has a small teapot and the poster is on or near the surface of the planet Earth, then that is a tiny teapot orbiting the sun. I myself have seen smallish teapots that were orbiting our sun. I possess a medium size kettle which is currently on my stove, which is orbiting the sun along with the kettle.
~: ls/proc/sys/vm/swappiness
ls:/proc/sys/vm/swappiness: No such file or directory
What kernels support this?
Re:This reminds me of an old convo I had ...
on
Tuning Linux VM swapping
·
· Score: 2, Interesting
"And remember when you could run a "fast" linux box on a P100 with 64MB of RAM and 128MB of swap?"
Yes, that would be the day before I "upgraded" from Red Hat Linux 6.2 to RHL 9. (P200 64MB, swap partition on a separate HD) I use fvwm and I don't expect mozilla to be fast, but it really sucks when it takes several seconds to get the menu to pop up on an xterm. I have a pathetic fantasy that I will upgrade to a 2.6 kernel and my system will work as well as it did 5 years ago (and that I will get an X server that supports my video card as well as xfree86 3.3 did).
Are there any current distros that use the 2.2 kernel?
Assuming the facts are accurate as represented--that is, that the images were used without permission--it's a pretty clear-cut case to me.
Of course it is. You missed the post I was originally replying to, which said (I paraphrase) that looking at a web page is illegal unless you have an explicit license "until a court rules otherwise", which is nonsense. I think I agree with everything you say, but that isn't what this little side discussion was about.
How should the law look at, for example, downloading a jpeg to view it in a browser?
One possibility is that this is equivalent to copying code into memory to run it, and therefore legal without an explicit license under copyright law as you described it. (I should have remembered that this was in the law, not a result of a court ruling. Thanks.)
Another possibility is that putting material on a public web server inherently implies permission to download and view it, with no explicit permission required. This could be construed as part of fair use or perhaps some sort of implicit license.
"It also means you have no right to download it seeing as downloading a file technically copies it (and yes, that technicality matters until a court rules otherwise)."
So, the web is inherently illegal except for public domain material. Fascinating theory.
Courts have ruled in other cases that incidental copies made as part of the normal use of a program do not violate copyright laws. It is hard to see that this is any different. You also ignore fair use. It is not illegal to tape a TV program so I can watch it at a different time, but it is illegal to make copies of the tape and sell them.
I have read a few court rulings (simply as an interested citizen), and judges do not seem to make hyper-technical interpretations of the law (such as claiming it is illegal to browse a copyrighted web page without an explicit license) when they defy common sense.
I have to say that the article does not improve my already low opinion of Tech Review (it used to be so much better).
But building a fusion reactor that can convert that tremendous heat into useful energy has posed an immense challenge. After decades of research, the conditions needed for fusion still can be attained only briefly, and these experimental fusion reactions produce less energy than is needed to ignite them.
The conditions needed for "hot" fusion can be easily attained. They are just expensive. No facility in the world currently exists that can handle the radiation that would be generated by a device like a tokamak running above break-even (where generated fusion power exceeds input power plus change in energy stored in the plasma). This was nearly achieved on the JET tokamak. Why don't they keep trying this? Because the facility cannot handle the radiation. Human beings have to be able to work on the experiment to do maintenance, so the equipment cannot be allowed to become too radioactive. In fact, no similar experiment consistently uses the mixture of deuterium and tritium most likely to be used in fusion reactors. No large hot fusion experiments achieve break-even because none of them are trying to achieve break-even.
"precise calorimetry at that level is actually pretty hard...the setup is far more sensitive to uncontrolled variables...than P-F were aware."
Along with this, measurements of reaction products like alphas, neutrons, and tritium can be very difficult to perform reliably at low levels.
I heard a talk by someone who did some recent work, and he talked about one gap in how physicists see the problem. He said that a lot of what is done to prepare containers and catalysts for some reactions in normal chemistry is practically voodoo. Some samples just do not work, for no known reason. Things have to be baked under vacuum ten times longer than what should be required to clean them. The truth is that some things are not as reproducible as they are expected to be, and the absence of easy reproducibility does not mean the original results were erroneous. Chemists understand this, but most physicists do not. If this applies to normal chemistry, it may apply equally to cold fusion experiments.
"There have been a lot of interesting results with various setups reported over the years"
Unfortunately, there has also been a lot of garbage touted as interesting results. I once read through a few reports suggested by CF advocates as some of the best evidence, and they did not meet the standards of a high school science project. Most scientists will not take CF seriously until the CF community polices itself. When lousy scientific work recieves acclaim because it shows the desired result, credibility is demolished. (I would never claim the CF is the only place this happens, but that is not an excuse.) When the CF community separates the serious work from the chaff itself, offering only solid experimental results to the world, then other scientists can start to pay attention.
"Good science fiction isn't fiction at all-- it's philosophy and prediction."
Not always. One aspect of science fiction is that the author has complete control over the universe in which it is set. The author can use this control to create an environment specially tuned for the exploration of a theme of traditional
literature. As an example, consider the themes of love and loneliness in Asimov's "The Naked Sun". Examining the hypothetical role of robots in society can also relate to the role of individual humans in today's society.
Certainly there are examples of what some might call pure or hard-core science fiction that match your description, like many of Asimov's robot short stories or Heinlein's early short stories. This mode is difficult to translate well into full-length novels, with exceptions. Compare for example Foundation and Empire, which addresses human emotions and identity, to Foundation, which is more technical and holds itself at a distance from human emotion. Not many science fiction writers can (or have) put together a decent novel which is primarily "philosophy and prediction."
I think that a lot of what is currently published as science fiction is much better as fiction than a lot of what is being published in the style of traditional fiction. Hard-core sf and non-hard-core sf play somewhat different roles in literature, and I am glad that we have both.
"forcing people to choose hard-to-remember passwords typically leads to writing the passwords down--often in obvious places--which makes the problem worse instead of better."
The infamous Bruce Schneier suggested an interesting solution to this. Use a long password that is composed of two parts. The first part should be easy to remember (and therefore probably easier to guess). The second part is a random character string including numbers and punctuation. Expect that users will write the second part down on their desk, in their wallets, or somewhere.
The random part of the password immunizes it against cracking. Adding the memorized part means that even someone who finds the written piece will have a difficult time getting into the account.
Obviously, a long, unguessable password that is never written down is best, but this idea recognizes that the ideal does not happen.
"I think it's been proven that scientific literature is hard to sell or maintain rights over. It's a prime example of the 'information wants to be free' principle."
I never violate copyright by putting journal articles on the web. On the other hand, I am elated when I find that some article I need has been put up on the web illegally by someone else, thereby saving mea trip to a library with a bag of quarters for the copier.
"So are you saying the previous distributions of linux weren't general purpose operating systems or that they weren't completely from open source software.
Many Linux distros include non open source software. SuSE's installer was not open source. I have an old Red Hat distro that includes a proprietary X server (and xfree86 as well, I believe). My memory and rpmfind sugest that Netscape 4 was included in some distros, and it certainly isn't open source.
Then you go and mention "it's great from a programming point of view," which illustrates my point all the more--you're again speaking as a *programmer* and not a user.
As a user, I like being able to indent text and create small tables in ASCII files using the tab key and the space bar rather than having to invoke the overhead of using a markup language for trivial formatting.
"Time to dust off the 40 year old NERVA boosters. Twice as efficient as the most powerful chemical rockets, longer burn time, energy to spare, and fueled by whatever gas you can find."
Thank you for the link.
Again, it seems you are not describing this correctly. They are not fueled by any gas. They are fueled by uranium. They use gas as reaction mass.
The NERVA boosters as described on wikipedia achieved only achieved 1% of the thrust that the space shuttle has. (75k pounds vs. 7M pounds.) The escape velocity of Mars is 45% the escape velocity of Earth, so a vehicle taking off from Mars would have to be similar in thrust to one taking off from Earth. This requires something much more powerful than the moon lander.
Also, the wikipedia article claims that the engines had serious problems that were never resolved. I would not want to fly to Mars using an engine that "eroded quite heavily" on the test stand. Getting a robust propulsion system on this principle would clearly require significant development.
Slashdot Mirror
As the pulse propagates, it changes shape. It is passing through a dispersive medium. The result of the shape change is that the peak in amplitude moves faster than c while the leading edge does not.
If allowed to propagate far enough, the peak would catch up to the leading edge. This might be equivalent to a shock front in a fluid. In any case, the dynamics of the propagation would change, and the peak would stop propagating faster than c.
It is debatable what rights he gave to his company by bringing the code "in the door", but automatic transfer of copyrights is not one of them. Though establishing his ownership could be hard if he doesn't have a very good record of what he produced before being hired.
Code written for work after the start of the job probably never belonged to him in the first place, so there is no issue of transfer.
Did you do any research into the relative amounts of energy used in constructing different washers? Think of a $1k front loader vs. a $400 top loader. That extra $600 either (1) is pure profit margin, or (2) pays for more complicated construction. (1) is unlikely in a competative market. (2) means it is likely more energy is used constructing the fancy washer.
I for one would like to know why the robots.txt at www.whitehouse.gov is blocking access to directories like /kids/teeball/iraq. Is there some national security implication that I am missing? Or /national-anthem/text. Can't allow people to get the words to the national anthem! Who knows what fool ideas they'll come up with.
Is it any wonder people are jittery about using MS software? I have two computers that double boot into Linux and MS Windows. I will boot into MS Windows when I really need to, for example someone sent me a MS Word file that OpenOffice can't understand or I am watching a DVD with features that ogle can't deal with. But I never dial up to an ISP or connect to a local network under MS Windows. I don't want to let them try to "phone home" to Redmond. I don't know what they might try to send, but whatever it is, it is none of MS's business.
Posted from a machine that dual boots Redhat Linux 9 and Microsoft Windows 95.
Nah. A three-dimensional rigid object with no exact symmetry has three axes around which it can rotate forever without precessing. The reason that any physical object will precess is that the rotation will never be exactly about one of the axes. The axes nevertheless still exist.
Rotation is not "stable" around any of the three axes. "Stable" would mean that any perturbation to the angular momentum would eventually damp out and the object would return to rotation about the axis. This does not happen for rigid bodies.
Furthermore, the object doesn't "eventually" precess. The rate of precession is constant after the spin is imparted to the object.
Now things will be different if you want to put your object in an atmosphere that damps the rotation or imparts a net force, let it vibrate or otherwise absorb energy or not move as a rigid body (flywheel seizes up), or have the gravitational field or some other force change with time. But this has nothing to do with the moments of inertia and axis of rotation.
If we put up a cylindrical satellite spinning around a principal axis (e.g. the one which is almost the theoretical axis of the cylinder), it will not stay that way forever. This is not due to any asymmetries or imperfections. It is because the interaction with the wisps of atmosphere and the various change gravitational fields will exert torques on it which change the axis of rotation.
Not quite. An object like a rectangular block of wood can be spun around any of three axes (the obvious one). A ball can be spun around any axis. A disk can be spun around the axis normal to the surface or any axis parallel to the surface.
I have moment-of-inertia tensors spinning in my head...
And the specific lines of UNIX SysV code illegally placed in the Linux kernel.
If the poster has a small teapot and the poster is on or near the surface of the planet Earth, then that is a tiny teapot orbiting the sun. I myself have seen smallish teapots that were orbiting our sun. I possess a medium size kettle which is currently on my stove, which is orbiting the sun along with the kettle.
~: ls /proc/sys/vm/swappiness /proc/sys/vm/swappiness: No such file or directory
ls:
What kernels support this?
Yes, that would be the day before I "upgraded" from Red Hat Linux 6.2 to RHL 9. (P200 64MB, swap partition on a separate HD) I use fvwm and I don't expect mozilla to be fast, but it really sucks when it takes several seconds to get the menu to pop up on an xterm. I have a pathetic fantasy that I will upgrade to a 2.6 kernel and my system will work as well as it did 5 years ago (and that I will get an X server that supports my video card as well as xfree86 3.3 did).
Are there any current distros that use the 2.2 kernel?
Endless print loops were not as much fun as POKEing random numbers into low-numbered memory addresses.
Of course it is. You missed the post I was originally replying to, which said (I paraphrase) that looking at a web page is illegal unless you have an explicit license "until a court rules otherwise", which is nonsense. I think I agree with everything you say, but that isn't what this little side discussion was about.
One possibility is that this is equivalent to copying code into memory to run it, and therefore legal without an explicit license under copyright law as you described it. (I should have remembered that this was in the law, not a result of a court ruling. Thanks.)
Another possibility is that putting material on a public web server inherently implies permission to download and view it, with no explicit permission required. This could be construed as part of fair use or perhaps some sort of implicit license.
So, the web is inherently illegal except for public domain material. Fascinating theory.
Courts have ruled in other cases that incidental copies made as part of the normal use of a program do not violate copyright laws. It is hard to see that this is any different. You also ignore fair use. It is not illegal to tape a TV program so I can watch it at a different time, but it is illegal to make copies of the tape and sell them.
I have read a few court rulings (simply as an interested citizen), and judges do not seem to make hyper-technical interpretations of the law (such as claiming it is illegal to browse a copyrighted web page without an explicit license) when they defy common sense.
Along with this, measurements of reaction products like alphas, neutrons, and tritium can be very difficult to perform reliably at low levels.
I heard a talk by someone who did some recent work, and he talked about one gap in how physicists see the problem. He said that a lot of what is done to prepare containers and catalysts for some reactions in normal chemistry is practically voodoo. Some samples just do not work, for no known reason. Things have to be baked under vacuum ten times longer than what should be required to clean them. The truth is that some things are not as reproducible as they are expected to be, and the absence of easy reproducibility does not mean the original results were erroneous. Chemists understand this, but most physicists do not. If this applies to normal chemistry, it may apply equally to cold fusion experiments.
"There have been a lot of interesting results with various setups reported over the years"
Unfortunately, there has also been a lot of garbage touted as interesting results. I once read through a few reports suggested by CF advocates as some of the best evidence, and they did not meet the standards of a high school science project. Most scientists will not take CF seriously until the CF community polices itself. When lousy scientific work recieves acclaim because it shows the desired result, credibility is demolished. (I would never claim the CF is the only place this happens, but that is not an excuse.) When the CF community separates the serious work from the chaff itself, offering only solid experimental results to the world, then other scientists can start to pay attention.
Not always. One aspect of science fiction is that the author has complete control over the universe in which it is set. The author can use this control to create an environment specially tuned for the exploration of a theme of traditional literature. As an example, consider the themes of love and loneliness in Asimov's "The Naked Sun". Examining the hypothetical role of robots in society can also relate to the role of individual humans in today's society.
Certainly there are examples of what some might call pure or hard-core science fiction that match your description, like many of Asimov's robot short stories or Heinlein's early short stories. This mode is difficult to translate well into full-length novels, with exceptions. Compare for example Foundation and Empire, which addresses human emotions and identity, to Foundation, which is more technical and holds itself at a distance from human emotion. Not many science fiction writers can (or have) put together a decent novel which is primarily "philosophy and prediction."
I think that a lot of what is currently published as science fiction is much better as fiction than a lot of what is being published in the style of traditional fiction. Hard-core sf and non-hard-core sf play somewhat different roles in literature, and I am glad that we have both.
The infamous Bruce Schneier suggested an interesting solution to this. Use a long password that is composed of two parts. The first part should be easy to remember (and therefore probably easier to guess). The second part is a random character string including numbers and punctuation. Expect that users will write the second part down on their desk, in their wallets, or somewhere.
The random part of the password immunizes it against cracking. Adding the memorized part means that even someone who finds the written piece will have a difficult time getting into the account.
Obviously, a long, unguessable password that is never written down is best, but this idea recognizes that the ideal does not happen.
I never violate copyright by putting journal articles on the web. On the other hand, I am elated when I find that some article I need has been put up on the web illegally by someone else, thereby saving mea trip to a library with a bag of quarters for the copier.
(Emphasis added.) I can't think of a single comment about this statement which isn't egregious raging flamebait.
To be fair, I am sure this reads differently from what the poster intended.
Many Linux distros include non open source software. SuSE's installer was not open source. I have an old Red Hat distro that includes a proprietary X server (and xfree86 as well, I believe). My memory and rpmfind sugest that Netscape 4 was included in some distros, and it certainly isn't open source.
Wow. Are variable names that start with the letters "i" through "n" automatically integers, too?
As a user, I like being able to indent text and create small tables in ASCII files using the tab key and the space bar rather than having to invoke the overhead of using a markup language for trivial formatting.
Thank you for the link.
Again, it seems you are not describing this correctly. They are not fueled by any gas. They are fueled by uranium. They use gas as reaction mass.
The NERVA boosters as described on wikipedia achieved only achieved 1% of the thrust that the space shuttle has. (75k pounds vs. 7M pounds.) The escape velocity of Mars is 45% the escape velocity of Earth, so a vehicle taking off from Mars would have to be similar in thrust to one taking off from Earth. This requires something much more powerful than the moon lander.
Also, the wikipedia article claims that the engines had serious problems that were never resolved. I would not want to fly to Mars using an engine that "eroded quite heavily" on the test stand. Getting a robust propulsion system on this principle would clearly require significant development.