rm -Rf / as nonroot will make you give a sigh of relief
I once demonstrated this to someone. 'Relief' is not quite what I felt on realizing I'd just deleted my home directory.
Re:really a superconductor?
on
Quantum Wires
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· Score: 1
I was under the impression that type-II superconductors consisted of small domains of Type-I that become additive macroscopically
I'm not really sure. In the BCS theory, Cooper pairs can only form at temperatures below about 40K. (The animations on this page are really cool.) Beyond that the lattice is just vibrating too much.
The current Tc record is 138K, so if cooper-pairs are forming there must be some other mechanism. Not that I'm a condensed matter physicist or anything.
High-Tc inorganic superconductors are all Type-II
Yes.
Re:really a superconductor?
on
Quantum Wires
·
· Score: 1
doubt the existence of a superconducting loop (at least using materials discovered so far) that can run for years "without decreasing"
The resistence of a superconductor is zero. That is the definition of a superconductor. You can go do the experiment yourself if you like. Order yourself a superconducting ring, stick it in a glass of liquid nitrogen, and measure the current with a compass.
The current will take about a millenium to decay to half its original value, but that's due to magnetic fields, not electrical resistence.
Re:really a superconductor?
on
Quantum Wires
·
· Score: 1
Superconductors must be able to form so-called Cooper Pairs in order for electrons to move in the coherent manner in which no energy is lost.
This describes type-I superconductors very well, but not type-II. I don't think anyone really understands type-II superconductivity.
Faith, as the original poster puts it, is the belief in something without evidence.
I think it's important to distinguish faith from dogma. 'Real' faith is based on personal experience - practically everybody has sporadic experiences that suggest there is a lot more to the universe than our senses and rational minds perceive or infer. The purpose of religion is to provide a structure within which these experiences can be supported, and used to develop an understanding of the universe different (but oftern complementary) to that provided by science. Developing such an understanding and faith stimulates further experiences which further strengthen faith and so on. You wouldn't say faith is based on evidence, but there is still discernment.
'Faith' that someone will fo to heaven if you run them over is not a personal faith, it is a misuse of dogma that is intended to support personal faith.
Moreover, there is no reason to believe that operation should not extend all the way down to absolute zero.
Except that, by definition, a device at absolute zero wouldn't be doing anything.
Re:Man who mistook his wife for a hat
on
Mapping the Mind
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· Score: 1
The twins had IQs of 60, couldn't reliably perform addition or subtraction, and couldn't even grasp the concept of multiplication or division.
Re:Man who mistook his wife for a hat
on
Mapping the Mind
·
· Score: 1
Now if they were able to distinguish prime numbers from a random list of very lengthy primes and non-primes, then that would be something.
There is an efficient algorithm for primality testing already.
And, seriously, being able to come up with twenty digit prime numbers off the top of your head like the twins did *is* something. And it poses quite a challenge to the reductionist approach to the mind , which is basically to map cognitive impairments with damage to specific parts to the brain. The two twins had serious brain defects, yet possesed abilities not found in people with undamaged brains.
Others just realize that we are the movie and enjoy the show.
We call them 'couch potatoes.'
The reductionist approach to the brain.
on
Mapping the Mind
·
· Score: 1
The simplest way to understand the function of some part of the brain is to find a person in whom it is damaged. Here you have it all: A man who believed that copulating with the pavement was normal; the famous man who mistook his wife for a hat;
I understood Oliver Sacks book to be a presentation of case studies where the reductionist approach to the brain was inadequate. At the end of "the man who mistook his wife for a hat" he says "Of course, the brain is a machine and a computer - everything in classical neurology is correct. But our mental processes, which constitute our being and our life, are not just abstract and mechanical, but personal as well - and, as such, involve not just classifying and categorising but judging and feeling also."
He describes this case as "a radical challenge to one of the most entrenched axions or assumptions of classical neurology - the notion that brain damage, any brain damage, reduces or removes the abstract and categorical attitude."
At no point does Dr Sacks pretend to identify what part of the guys brain has been damaged. And it is not entirely clear what 'functions' are missing from his brain. He can see perfectly, recognize and identify abstract shapes such as the platonic solids, and recognize people by their 'body music' - the way they move. Yet he describes a glove as 'a continuous surface, infolded on itself. It appears to have five outpouchings' and, of course, mistakes his wife's head for a hat. What has changed in neuroscience since that book was written?
I don't believe that understanding the brain is synonymous with understanding yourself.
Finally, our most unique and advanced feature -- consciousness -- is explained.
That's great. But I'd be happier if someone could define it for me first.
Re:I just want C++ programs to COMPILE faster
on
GCC 4.0 Preview
·
· Score: 1
Namespaces in the STL are what drove me from C++ in the first place
What namespaces? All STL classes are included in a single one called 'std'. And you can just write 'using namespace std' in the appropriate scope and be done with it.
Java is ever more elegant, perhaps one reason it eclipses C++ in the general business environment
I'm not sure the business environment has ever based its choices on elegance.
$|=1 is shorthand for $OUTPUT_AUTOFLUSH = 1, which is about as clear and intuitive you can get when specifying that the output buffer should be flushed after every print or write. If you want to be clear and intuitive, then you shouldn't be using shorthand.
And, on a personal note, PHP has got to be one of the most boring languages ever invented.
There's lots of explanations of the original double slit experiment, like this and this (the second one is a java applet demonstration)
This experiment was originally performed with light and proved that it behaved like a wave. Essentially when two waves combine you can get constructive interference when they pile up on top of each other, or destructive interference when they cancel each other out. This can be observed as an alternating pattern of light and dark on a screen or photographic film.
Since 1905, however, we also know that light behaves like a particle. If we reduce the intensity of the light being shone at the slits to the point where only one photon is being emitted at a time, then you'd think that it would either go through one slit or the other. Since there's only one photon then there should be no interference effects. That's what I'd expect to happen anyway, but it turns out this isn't what happens - an interference pattern is still produced. This means that the photon must have passed through both slits, but it can't have passed through both slits because it's an indivisible photon and this is an example of quantum mechanics not making any sense. It doesn't make any sense to anybody, but somehow it's still a useful theory.
Later last century physicists performed the same experiment with 'real' particles like electrons, atoms, bucky-balls etc and got the same results. The particle went through both slits, but can't have gone through both slits because it's just a single particle..
This 'interference' in time experiment is very similar, but instead of an electron passing through different slits it is emitted from an atom at different times. This produce an interference pattern because, for example, the 'crest' of the later one will arrive at the detector at the same time as the 'trough' of the earlier one. But it can't have been emitted at both times because it's just a single electron... you get the idea.
Warning: Too many connections in/var/www/pnadodb/drivers/adodb-mysql.inc.php on line 108
Once again someone decides to use mysql_pconnect without really understanding what it does. That function should have red flashing warning light all over it in the PHP docs.
The vast majority of computer users aren't admins, and don't have an admin who comes to their house to secure their system. These people need 'admins' built into their software.
I can't believe this got modded insightful. The vast majority of computer users aren't admins, and don't have an admin coming round to their house to 'secure' their system, or stand over their shoulder to tell them they shouldn't open that email attachment.
The 'admins' need to be built into the software you tard.
It's an ugly language full of redundancy, bugs and inconsistent style
You can't say it's uglier than Perl. Although at least Perl doesn't gives you error messages like "unexpected T_PAAMAYIM_NEKUDOTAYIM" which is only funny to anyone who speaks Hebrew.
Slashdot Mirror
-rw-r--r-- 1 root root 808295 Mar 24 2004
-rw-r--r-- 1 root root 1458226 Mar 28 15:19
I suppose it is a little bigger. I did compile scsi support into the second one for a usb keydrive though.
rm -Rf / as nonroot will make you give a sigh of relief
I once demonstrated this to someone. 'Relief' is not quite what I felt on realizing I'd just deleted my home directory.
I was under the impression that type-II superconductors consisted of small domains of Type-I that become additive macroscopically
I'm not really sure. In the BCS theory, Cooper pairs can only form at temperatures below about 40K. (The animations on this page are really cool.) Beyond that the lattice is just vibrating too much.
The current Tc record is 138K, so if cooper-pairs are forming there must be some other mechanism. Not that I'm a condensed matter physicist or anything.
High-Tc inorganic superconductors are all Type-II
Yes.
doubt the existence of a superconducting loop (at least using materials discovered so far) that can run for years "without decreasing"
The resistence of a superconductor is zero. That is the definition of a superconductor. You can go do the experiment yourself if you like. Order yourself a superconducting ring, stick it in a glass of liquid nitrogen, and measure the current with a compass.
The current will take about a millenium to decay to half its original value, but that's due to magnetic fields, not electrical resistence.
Superconductors must be able to form so-called Cooper Pairs in order for electrons to move in the coherent manner in which no energy is lost.
This describes type-I superconductors very well, but not type-II.
I don't think anyone really understands type-II superconductivity.
Faith, as the original poster puts it, is the belief in something without evidence.
I think it's important to distinguish faith from dogma. 'Real' faith is based on personal experience - practically everybody has sporadic experiences that suggest there is a lot more to the universe than our senses and rational minds perceive or infer. The purpose of religion is to provide a structure within which these experiences can be supported, and used to develop an understanding of the universe different (but oftern complementary) to that provided by science. Developing such an understanding and faith stimulates further experiences which further strengthen faith and so on. You wouldn't say faith is based on evidence, but there is still discernment.
'Faith' that someone will fo to heaven if you run them over is not a personal faith, it is a misuse of dogma that is intended to support personal faith.
Now, granted, when the electrons start moving, you can talk about them having a temperature.
Well, that was my point.
These two I imagine could be proved or disproved relatively easily.
Faith can be used to justify appaling acts and discrimination or can limit development of society, and is not something to be respected.
That's ridiculous. It's like saying 'physics can be used to destroy entire cities
Moreover, there is no reason to believe that operation should not extend all the way down to absolute zero.
Except that, by definition, a device at absolute zero wouldn't be doing anything.
The twins had IQs of 60, couldn't reliably perform addition or subtraction, and couldn't even grasp the concept of multiplication or division.
Now if they were able to distinguish prime numbers from a random list of very lengthy primes and non-primes, then that would be something.
There is an efficient algorithm for primality testing already.
And, seriously, being able to come up with twenty digit prime numbers off the top of your head like the twins did *is* something. And it poses quite a challenge to the reductionist approach to the mind , which is basically to map cognitive impairments with damage to specific parts to the brain. The two twins had serious brain defects, yet possesed abilities not found in people with undamaged brains.
Others just realize that we are the movie and enjoy the show.
We call them 'couch potatoes.'
The simplest way to understand the function of some part of the brain is to find a person in whom it is damaged. Here you have it all: A man who believed that copulating with the pavement was normal; the famous man who mistook his wife for a hat;
I understood Oliver Sacks book to be a presentation of case studies where the reductionist approach to the brain was inadequate. At the end of "the man who mistook his wife for a hat" he says "Of course, the brain is a machine and a computer - everything in classical neurology is correct. But our mental processes, which constitute our being and our life, are not just abstract and mechanical, but personal as well - and, as such, involve not just classifying and categorising but judging and feeling also."
He describes this case as "a radical challenge to one of the most entrenched axions or assumptions of classical neurology - the notion that brain damage, any brain damage, reduces or removes the abstract and categorical attitude."
At no point does Dr Sacks pretend to identify what part of the guys brain has been damaged. And it is not entirely clear what 'functions' are missing from his brain. He can see perfectly, recognize and identify abstract shapes such as the platonic solids, and recognize people by their 'body music' - the way they move. Yet he describes a glove as 'a continuous surface, infolded on itself. It appears to have five outpouchings' and, of course, mistakes his wife's head for a hat. What has changed in neuroscience since that book was written?
I don't believe that understanding the brain is synonymous with understanding yourself.
Finally, our most unique and advanced feature -- consciousness -- is explained.
That's great. But I'd be happier if someone could define it for me first.
Namespaces in the STL are what drove me from C++ in the first place
What namespaces? All STL classes are included in a single one called 'std'. And you can just write 'using namespace std' in the appropriate scope and be done with it.
Java is ever more elegant, perhaps one reason it eclipses C++ in the general business environment
I'm not sure the business environment has ever based its choices on elegance.
$|=1 is shorthand for $OUTPUT_AUTOFLUSH = 1, which is about as clear and intuitive you can get when specifying that the output buffer should be flushed after every print or write. If you want to be clear and intuitive, then you shouldn't be using shorthand.
And, on a personal note, PHP has got to be one of the most boring languages ever invented.
You can check this out if you're really interested.
There's lots of explanations of the original double slit experiment, like this and this (the second one is a java applet demonstration)
... you get the idea.
This experiment was originally performed with light and proved that it behaved like a wave. Essentially when two waves combine you can get constructive interference when they pile up on top of each other, or destructive interference when they cancel each other out. This can be observed as an alternating pattern of light and dark on a screen or photographic film.
Since 1905, however, we also know that light behaves like a particle. If we reduce the intensity of the light being shone at the slits to the point where only one photon is being emitted at a time, then you'd think that it would either go through one slit or the other. Since there's only one photon then there should be no interference effects. That's what I'd expect to happen anyway, but it turns out this isn't what happens - an interference pattern is still produced. This means that the photon must have passed through both slits, but it can't have passed through both slits because it's an indivisible photon and this is an example of quantum mechanics not making any sense. It doesn't make any sense to anybody, but somehow it's still a useful theory.
Later last century physicists performed the same experiment with 'real' particles like electrons, atoms, bucky-balls etc and got the same results. The particle went through both slits, but can't have gone through both slits because it's just a single particle..
This 'interference' in time experiment is very similar, but instead of an electron passing through different slits it is emitted from an atom at different times. This produce an interference pattern because, for example, the 'crest' of the later one will arrive at the detector at the same time as the 'trough' of the earlier one. But it can't have been emitted at both times because it's just a single electron
Warning: Too many connections in /var/www/pnadodb/drivers/adodb-mysql.inc.php on line 108
Once again someone decides to use mysql_pconnect without really understanding what it does. That function should have red flashing warning light all over it in the PHP docs.
Fact: any box is as secure at the admin makes it.
The vast majority of computer users aren't admins, and don't have an admin who comes to their house to secure their system. These people need 'admins' built into their software.
Fact: any box is as secure at the admin makes it
I can't believe this got modded insightful. The vast majority of computer users aren't admins, and don't have an admin coming round to their house to 'secure' their system, or stand over their shoulder to tell them they shouldn't open that email attachment.
The 'admins' need to be built into the software you tard.
I don't supposed Supernova 1987a don't count?
No. Must have a magnitude of at least -5. Or is that at most -5? Something like Supernova 1006 would be good.
Is that at least one giant goes supernova in my lifetime. I don't think that's too much to ask
It's an ugly language full of redundancy, bugs and inconsistent style
You can't say it's uglier than Perl. Although at least Perl doesn't gives you error messages like "unexpected T_PAAMAYIM_NEKUDOTAYIM" which is only funny to anyone who speaks Hebrew.
The biggest complaint that I have is he does indeed change his mind on things
Most people, when they realize that they're wrong or havent't completely understood something, change their minds. What do you do?