i am fully aware of the difference between the two, but in some sense, they are interchangeable. if it is possible for a machine to pass the turing test, then a turing machine can pass it. if there exists a turing machine that can pass a turing test, then the turing test must be computable (this can be shown with a simple reduction). and the argument works fine from there. sorry for the confusion
this entire problem is equivalent to asking whether or not the human mind is entirely physical, or if the mind and brain are separate (and thus the mind is separate from the body), otherwise known as the mind/body problem. if the mind is not separate, then theoretically, there should be no trouble simulating a human mind with a computer. so, in order for the point to hold the mind needs to be separate. a few years back, i had discussion with one of my philosophy profs, and what emerged was an interesting argument which sought to prove that the mind/body problem is undecidable. it ran (AFAIK) something like this...
1. only a mind-bearing being (MBB) can distinguish a being with a mind from one without 2. you can only know if Y is an MBB if you can distinguish him from a non-MBB. 3. by 1 & 2, no turing machine (clearly not a mind) can decide whether a being is an MBB. 4. by 3, it is undecidable whether or not a being is an MBB
comments: 1 is essentially assuming that (if minds exist), no machine will ever pass the turing test. i think this is a fairly good assumption since otherwise, this whole argument feels terribly moot to me. more specifically, suppose 1 is false, then it is possible to create an turing machine that will pass the turing test trivially (enumerate all possibilities, and test itself for each possibility). stupid... but it works (in theory). so, this whole argument makes sense only if a machine has no way of checking its own actions to know whether it's a machine or not.
2 is a crucial assumption, because it basically does away with the possibility of just "knowing" a being is an MBB a-priori of any test an MBB gives him/her. without this assumption, things start to fall apart *really* fast, since a machine can programmed, then, to "know" that it is an MBB. there will be no way of proving it right or wrong, since 2 is false.
note on conclusion: the conclusion basically puts the knowledge of MBB-ness outside the realm of deducable knowledge. i guess, as in my previous comment, you could assume that you just "know" that something is an MBB, but this would just beg the question
I think you're completely right, but I also think that the whole point of an article like this is to point out how silly articles that rag on Linux after only having used it for a short period of time are. Irony is your friend.
I didn't realize there was more than one Caribou Coffee in D.C. i was thinking of the other one, which is closer to logan circle. obviously nowhere in D.C. is really "the middle of nowhere." the one i'm thinking of is just a bit off the path, although i'm sure it gets plenty of customers, too. point taken, though
is it just me, but that cafe is sorta in the middle of nowhere, isn't it? it seems to me that attracting any sort of customer would be good for them. my point is that it all depends on how much space you have and whether you care about the kind of customer you get. no offense, but most places don't want leechers like yourself.
hate responding to what looks like a troll, but presentation of a school to prospective students is very important. all you get when you look online is that they are #1 of lots of lists, not that they provide a good undergraduate education. my girlfriend transferred from notre dame to an ivy league, thinking it would be better, so she *can* tell, and she always says that notre dame was a much better undergraduate experience, where, as grandparent said, they care a lot about students.
although you may be right, hollywood has systematically killed the french film industry. from having studied the history of french cinema, my gut reaction is call bullshit on this one, but i don't know the statistics... french films basically don't leave france anymore, and fewer and fewer of the younger generation are viewing french film.
i completely agree. i was merely playing devil's advocate, and trying not to fall for the flamebait. it's not a contest, but morally, i agree much more with what the linux community is doing than with what bill gates is doing. he did not create microsoft with the intention of giving part of its profits to needy children: that is merely a byproduct of his success. clearly, few if none in the linux community can afford to give that much money to charity, so each of them do what they can. the difference is that the goal of the linux community is charity and "giving back", which is much more noble.
this is all well and good, but as has been mentioned previously in other threads, linux will have a greater long term effect on developing 3rd world countries than $750m right now. free software reduces the countries' dependence on larger nations, helps develops critical technological infrastructure, and allows people to learn the skills they need to get jobs in later generations.
one of the authors of the book for that class, dexter kozen, showed me that CS theory, while not always terribly useful in the field, can be very exciting and really makes you think about things differently. i took his graduate Design and Analysis of Algorithms course and really fell in love with it, even though i don't want to pursue a career in theoretical CS.
i think you are right on target-- he is reimplementing old ideas and while i am sure he enjoys what he does, there are plenty of opportunities to make new and interesting stuff in CS.
mod me to hell if you must, but what exactly are these glorious advantages??
the only "advantage" i can think of is that the kernel is more secure than the windows core. the rest is all software. if you put firefox, openoffice, gaim, cygwin on a windows system the only thing you are now missing that might possibly make linux better is the desktop (kde, gnome) and package management (ala apt). you can say that X's network transparency or the multi-user abilities of linux are better, but the average Joe doesn't need network transparency (and get a good X server from cygwin anyway) and doesn't give a crap about multi-user abilities. neither kde nor gnome has any advantages over windows. and package management is not something the average really cares about either.
it's so typically slashdot to equate firefox with linux. i use linux because the first computer i ever used was a unix machine. i prefer to type commands most of the time as opposed to using the mouse. also, being a fully functional unix operating system, i prefer it for development. however, there is seriously nothing that linux has to offer the average joe. nothing! it's not a superior kernel or operating system (feature wise) by any stretch of the imagination (with a rather backwards design), so everyone, please stop saying "use firefox, switch to linux!!"
while these types of devices currently seem to require a lot of training to get the user to figure out what is necessary to move the cursor, in the future, the sensitivity of these devices will likely be such that configuring it will be like configuring controls for a game. "click here and think 'right'", etc.
You have to define what you mean by being disenfranchised. Taking this to an extreme, how is your vote "counted" any more if you voted for the candidate that lost? it's still a majority vote, just among a different group of people. one way to look at it is to see that with the current system, there is a greater "voter power," where power is defined as the probability of overturning an entire election. your vote *is* counted, it just happens to be in the minority, so the outcome is unchanged.
what you are saying doesn't really make sense. how are you picking the content with google any more than a9? doing an image search on google gives the same results (not suprisingly) as a9 images do.
this a C library, not a virtual machine/language like jvm/java. the idea is not to have code run without recompile on all platforms, but rather that *all* you need is a recompile. more specifically, you don't need to have platform specific cases in your code. code becomes pretty unmaintainable when it is littered with #ifdefs
go look at enumeration machines. they never terminate either; all they do is spit out stuff once in a while. you can think of an enumeration machine emulating a lambda calculus if you prefer functional programming. the looping of the server says little about its mathematical value.
for example, it is possible to construct an enumeration machine that will output all multiples of 2 (provably). similarly, it may be possible to prove that the output of your program respects some rigorous properties. in fact, there is a whole field of computer science/mathematics that deals with reasoning about programs
this is all well and good, assuming ofcourse that you don't use the hash table as the *only* access to the data structure at hand and that there is no reference to the key. personal insults aside, perhaps you should read the links you post and think how its uses might not be appropriate for all cases.
from the site: This class is intended primarily for use with key objects whose equals methods test for object identity using the == operator. Once such a key is discarded it can never be recreated, so it is impossible to do a lookup of that key in a WeakHashMap at some later time and be surprised that its entry has been removed.
another note: Thus care should be taken to ensure that value objects do not strongly refer to their own keys, either directly or indirectly, since that will prevent the keys from being discarded.
in the cases where i have used them, this was indeed the cases, so WeakHashMaps would have been useless. i have indeed used WeakHashMaps; they tend to be OK for things like hashing an index into some "collection" like data structure which has very expensive access, but can be indexed otherwise.
Huh? What are these mysterious "persistent collections" you speak of? Yeah, if you hold a reference to a collection and leave an object in it, it won't get garbage collected. Duh. Don't hold onto the reference. And if you actually manage to create circular references, well, that's your own fault... the JVM can only do so much.
"don't hold on to the reference" is equivalent to saying "free it." i have often used hash tables of one form or another to speed up lookup times into various data structures (indeed that's what they are for). they are especially useful when a system manages a dynamic set of objects, and there is no direct way to map from one representation of the object to another. anywho, these hash tables are kept around forever, so all objects need to be "freed" from the hash table. this isn't such an uncommon occurrence, so saying "don't hold on to it" is silly.
you are actually incorrect about circular references with respect to garbage collection (it handles them just fine), as if the GC didn't resolve them correctly, delegation would not work.
you imply that the problems in C are "scaling" problems. i have managed plenty of C projects, and, at least as i managed them, they were about as easy to manage as java (portability not-withstanding).
java introduces speed problems. by itself, it isn't slow, as many benchmarks will attest, but when you have lots of objects to garbage collect, the real-time guarantee is lost, since a full/tenured GC pass will take up a significant amount of time, so a lot of time is spent introducing caches and reusable objects, since setting an object to null will still require it to be garbage colelcted-- memory management problems just the same.
I'm not sure what your point is, here (especially the reference to interfaces). In C/C++, you need a source file as well as a header file, and need to track both. The advantage of Java is that the two concepts are merged, so you don't have these nasty dependencies to deal with.
if you have circular references between modules of a project (e.g. classes in different jars refer and call methods of objects in each other), then an interface is needed for them to compile separately. this is the *exact* same purposes of a header file. if everything was in one file in a C/C++ project, you wouldn't need header files either. these interfaces, unless managed well (like well managed header files) tend to grow just the same.
i am no claiming that java has all the problems of C/C++, as it definitely solves many pointer problems. some memory issues, and some cross-platform issues, it is not the end-all, be-all of languages, and as such, still has many (often ideosyncratic) issues.
frankly, this is a somewhat naive point of view. java can leak memory just like any other language. sure, you wan't forget to free something, but java might if you leave it lying around in some persistent collection. sure, you might not have header files, instead you have interfaces which allow different classes to depend on each other. java does alleviate the problem of pointers, but it has plenty of other problems it introduces. the stuff you mention isn't "crap," it's just that java masquerades most of those things to make it easier for simple projects. as the size of the project grows, java has as many problems as other programming languages.
is it just me being paranoid, or is not having any windows and having cameras send external images to the cockpit a "bad thing." obviously, without computer systems, the planes are almost useless, but if anything happens to the camera, the pilot can't even *see* outside the plane.
both xine and mplayer already play DVDs (althought mplayer doesn't support dvd menus yet). i think the inclusion of powerDVD was to counter the claim by some linux using DeCSS defenders that "well, we don't have a single legal way to play DVDs..."
Slashdot Mirror
i am fully aware of the difference between the two, but in some sense, they are interchangeable. if it is possible for a machine to pass the turing test, then a turing machine can pass it. if there exists a turing machine that can pass a turing test, then the turing test must be computable (this can be shown with a simple reduction). and the argument works fine from there. sorry for the confusion
this entire problem is equivalent to asking whether or not the human mind is entirely physical, or if the mind and brain are separate (and thus the mind is separate from the body), otherwise known as the mind/body problem. if the mind is not separate, then theoretically, there should be no trouble simulating a human mind with a computer. so, in order for the point to hold the mind needs to be separate. a few years back, i had discussion with one of my philosophy profs, and what emerged was an interesting argument which sought to prove that the mind/body problem is undecidable. it ran (AFAIK) something like this...
1. only a mind-bearing being (MBB) can distinguish a being with a mind from one without
2. you can only know if Y is an MBB if you can distinguish him from a non-MBB.
3. by 1 & 2, no turing machine (clearly not a mind) can decide whether a being is an MBB.
4. by 3, it is undecidable whether or not a being is an MBB
comments:
1 is essentially assuming that (if minds exist), no machine will ever pass the turing test. i think this is a fairly good assumption since otherwise, this whole argument feels terribly moot to me. more specifically, suppose 1 is false, then it is possible to create an turing machine that will pass the turing test trivially (enumerate all possibilities, and test itself for each possibility). stupid... but it works (in theory). so, this whole argument makes sense only if a machine has no way of checking its own actions to know whether it's a machine or not.
2 is a crucial assumption, because it basically does away with the possibility of just "knowing" a being is an MBB a-priori of any test an MBB gives him/her. without this assumption, things start to fall apart *really* fast, since a machine can programmed, then, to "know" that it is an MBB. there will be no way of proving it right or wrong, since 2 is false.
note on conclusion: the conclusion basically puts the knowledge of MBB-ness outside the realm of deducable knowledge. i guess, as in my previous comment, you could assume that you just "know" that something is an MBB, but this would just beg the question
I think you're completely right, but I also think that the whole point of an article like this is to point out how silly articles that rag on Linux after only having used it for a short period of time are. Irony is your friend.
I didn't realize there was more than one Caribou Coffee in D.C. i was thinking of the other one, which is closer to logan circle. obviously nowhere in D.C. is really "the middle of nowhere." the one i'm thinking of is just a bit off the path, although i'm sure it gets plenty of customers, too. point taken, though
is it just me, but that cafe is sorta in the middle of nowhere, isn't it? it seems to me that attracting any sort of customer would be good for them. my point is that it all depends on how much space you have and whether you care about the kind of customer you get. no offense, but most places don't want leechers like yourself.
hate responding to what looks like a troll, but presentation of a school to prospective students is very important. all you get when you look online is that they are #1 of lots of lists, not that they provide a good undergraduate education. my girlfriend transferred from notre dame to an ivy league, thinking it would be better, so she *can* tell, and she always says that notre dame was a much better undergraduate experience, where, as grandparent said, they care a lot about students.
although you may be right, hollywood has systematically killed the french film industry. from having studied the history of french cinema, my gut reaction is call bullshit on this one, but i don't know the statistics... french films basically don't leave france anymore, and fewer and fewer of the younger generation are viewing french film.
i completely agree. i was merely playing devil's advocate, and trying not to fall for the flamebait. it's not a contest, but morally, i agree much more with what the linux community is doing than with what bill gates is doing. he did not create microsoft with the intention of giving part of its profits to needy children: that is merely a byproduct of his success. clearly, few if none in the linux community can afford to give that much money to charity, so each of them do what they can. the difference is that the goal of the linux community is charity and "giving back", which is much more noble.
this is all well and good, but as has been mentioned previously in other threads, linux will have a greater long term effect on developing 3rd world countries than $750m right now. free software reduces the countries' dependence on larger nations, helps develops critical technological infrastructure, and allows people to learn the skills they need to get jobs in later generations.
one of the authors of the book for that class, dexter kozen, showed me that CS theory, while not always terribly useful in the field, can be very exciting and really makes you think about things differently. i took his graduate Design and Analysis of Algorithms course and really fell in love with it, even though i don't want to pursue a career in theoretical CS.
i think you are right on target-- he is reimplementing old ideas and while i am sure he enjoys what he does, there are plenty of opportunities to make new and interesting stuff in CS.
woooah!! is it just me, or did someone finally get the smart idea to submit a reg-free link to a nytimes story??
</sarcasm>
mod me to hell if you must, but what exactly are these glorious advantages??
the only "advantage" i can think of is that the kernel is more secure than the windows core. the rest is all software. if you put firefox, openoffice, gaim, cygwin on a windows system the only thing you are now missing that might possibly make linux better is the desktop (kde, gnome) and package management (ala apt). you can say that X's network transparency or the multi-user abilities of linux are better, but the average Joe doesn't need network transparency (and get a good X server from cygwin anyway) and doesn't give a crap about multi-user abilities. neither kde nor gnome has any advantages over windows. and package management is not something the average really cares about either.
it's so typically slashdot to equate firefox with linux. i use linux because the first computer i ever used was a unix machine. i prefer to type commands most of the time as opposed to using the mouse. also, being a fully functional unix operating system, i prefer it for development. however, there is seriously nothing that linux has to offer the average joe. nothing! it's not a superior kernel or operating system (feature wise) by any stretch of the imagination (with a rather backwards design), so everyone, please stop saying "use firefox, switch to linux!!"
while these types of devices currently seem to require a lot of training to get the user to figure out what is necessary to move the cursor, in the future, the sensitivity of these devices will likely be such that configuring it will be like configuring controls for a game. "click here and think 'right'", etc.
You have to define what you mean by being disenfranchised. Taking this to an extreme, how is your vote "counted" any more if you voted for the candidate that lost? it's still a majority vote, just among a different group of people. one way to look at it is to see that with the current system, there is a greater "voter power," where power is defined as the probability of overturning an entire election. your vote *is* counted, it just happens to be in the minority, so the outcome is unchanged.
what you are saying doesn't really make sense. how are you picking the content with google any more than a9? doing an image search on google gives the same results (not suprisingly) as a9 images do.
or does anyone else find it funny that a slashdot comment is linked to in a JSR?
this a C library, not a virtual machine/language like jvm/java. the idea is not to have code run without recompile on all platforms, but rather that *all* you need is a recompile. more specifically, you don't need to have platform specific cases in your code. code becomes pretty unmaintainable when it is littered with #ifdefs
go look at enumeration machines. they never terminate either; all they do is spit out stuff once in a while. you can think of an enumeration machine emulating a lambda calculus if you prefer functional programming. the looping of the server says little about its mathematical value.
for example, it is possible to construct an enumeration machine that will output all multiples of 2 (provably). similarly, it may be possible to prove that the output of your program respects some rigorous properties. in fact, there is a whole field of computer science/mathematics that deals with reasoning about programs
this is all well and good, assuming ofcourse that you don't use the hash table as the *only* access to the data structure at hand and that there is no reference to the key. personal insults aside, perhaps you should read the links you post and think how its uses might not be appropriate for all cases.
from the site: This class is intended primarily for use with key objects whose equals methods test for object identity using the == operator. Once such a key is discarded it can never be recreated, so it is impossible to do a lookup of that key in a WeakHashMap at some later time and be surprised that its entry has been removed.
another note: Thus care should be taken to ensure that value objects do not strongly refer to their own keys, either directly or indirectly, since that will prevent the keys from being discarded.
in the cases where i have used them, this was indeed the cases, so WeakHashMaps would have been useless. i have indeed used WeakHashMaps; they tend to be OK for things like hashing an index into some "collection" like data structure which has very expensive access, but can be indexed otherwise.
Huh? What are these mysterious "persistent collections" you speak of? Yeah, if you hold a reference to a collection and leave an object in it, it won't get garbage collected. Duh. Don't hold onto the reference. And if you actually manage to create circular references, well, that's your own fault... the JVM can only do so much.
"don't hold on to the reference" is equivalent to saying "free it." i have often used hash tables of one form or another to speed up lookup times into various data structures (indeed that's what they are for). they are especially useful when a system manages a dynamic set of objects, and there is no direct way to map from one representation of the object to another. anywho, these hash tables are kept around forever, so all objects need to be "freed" from the hash table. this isn't such an uncommon occurrence, so saying "don't hold on to it" is silly.
you are actually incorrect about circular references with respect to garbage collection (it handles them just fine), as if the GC didn't resolve them correctly, delegation would not work.
you imply that the problems in C are "scaling" problems. i have managed plenty of C projects, and, at least as i managed them, they were about as easy to manage as java (portability not-withstanding).
java introduces speed problems. by itself, it isn't slow, as many benchmarks will attest, but when you have lots of objects to garbage collect, the real-time guarantee is lost, since a full/tenured GC pass will take up a significant amount of time, so a lot of time is spent introducing caches and reusable objects, since setting an object to null will still require it to be garbage colelcted-- memory management problems just the same.
I'm not sure what your point is, here (especially the reference to interfaces). In C/C++, you need a source file as well as a header file, and need to track both. The advantage of Java is that the two concepts are merged, so you don't have these nasty dependencies to deal with.
if you have circular references between modules of a project (e.g. classes in different jars refer and call methods of objects in each other), then an interface is needed for them to compile separately. this is the *exact* same purposes of a header file. if everything was in one file in a C/C++ project, you wouldn't need header files either. these interfaces, unless managed well (like well managed header files) tend to grow just the same.
i am no claiming that java has all the problems of C/C++, as it definitely solves many pointer problems. some memory issues, and some cross-platform issues, it is not the end-all, be-all of languages, and as such, still has many (often ideosyncratic) issues.
frankly, this is a somewhat naive point of view. java can leak memory just like any other language. sure, you wan't forget to free something, but java might if you leave it lying around in some persistent collection. sure, you might not have header files, instead you have interfaces which allow different classes to depend on each other. java does alleviate the problem of pointers, but it has plenty of other problems it introduces. the stuff you mention isn't "crap," it's just that java masquerades most of those things to make it easier for simple projects. as the size of the project grows, java has as many problems as other programming languages.
ski, ba bop, ba dopp bop;
ba bop, ba dopp bop;
sk, ba bop, ba dopp bop.
ba bop, bah dah bah dah bah dah bah dah
works surprisingly well with some of the voices
is it just me being paranoid, or is not having any windows and having cameras send external images to the cockpit a "bad thing." obviously, without computer systems, the planes are almost useless, but if anything happens to the camera, the pilot can't even *see* outside the plane.
both xine and mplayer already play DVDs (althought mplayer doesn't support dvd menus yet). i think the inclusion of powerDVD was to counter the claim by some linux using DeCSS defenders that "well, we don't have a single legal way to play DVDs..."
for once my sig is appropriate to your comment and the article :)