I think it is a modern developement: in ancient times people actually believed that one could write everything about a subject without leaving anything, probably also because in most disciplines people knew much less than we do today (and as a matter of fact many people succeded in gaining an almost complete knowdlege of disparate disciplines, without our need to specialize).
Another possible reason is that we consider books to be a way to communicate ideas between contemporary people, so that knowdlege can be shared and used; in ancient times I believe that books were meant more for posterity than for their contemporaries, as most people who studied some subject tended to live in the same place (Alexandria, in a certain period), so they probably foud easier to share their knowdlege between themselves orally.
The article isn't much clear about the actual speed: it is 3 megabytes per second (usually written MBps) or 3 megabit per second (Mbps, as they wrote)? I believe that usually connection speed is measured in Mbps (bits, not bytes), but they may have different habits...
I seem to remember that all of the math books we have from the "Greeks" (actually, people from the east costs of the Mediterranean who happended to use some greek dialect for commercial and cultural exchanges) were meant to show results, not problems: most of them are some sorts of summae where somebody expose everything that is known about some subject, with more or less comments and precisations. Some of them actually include what probably were original results of the authors, but always as facts, not problems.
So, if we look back to greek times we can't have documented problems, but only problems that could have been asked with their knowdlege, expecially if it's similar to some problem they actually solved. If we accept this kind of problems, I believe that the existance of infinite perfect numbers could be a good candidate, as the Greek knew about them, and actually worried about the existence of infinite numbers of other kinds (prime, etc.).
If, on the other side, you want actual written documentation about the problem, I'm afraid that either we find some fragment of a letter written by some greek or arabian mathematician (quite unlikely) or we have to focus on renaissance.
Anyway, I'm not sure that problems with fibonacci numbers actually date to Fibonacci's era, as i seem to remember that they were only a small part of his work, and that they were extensively studied only later (by some 1800 French matematician?)
As far as I know pi is just a number: it exists and it has his own value, like 666, sqrt(2), e, i, etc.
I suppose that the main reason why it has a name is that lots of geometrical constant happen to belong to Q(pi) (i.e. the minimal subfield of the complex field that contains all rational numbers and pi); since Q(pi) is also an (infinite dimensional) vector space on Q, and most of the useful constant belongs to the subspace generated by 1 and pi, we can just write them as a*1+b*pi and we're able to work with them in an easier way.
The "definition of pi" is just like the definition of any other real number, as a Dedekin section (not sure it's the name you use in english), and it happens not to say much about its value. Then when you have real numbers you can say whether two of them are the same or not, so you can demostrate that, e.g. the ratio between circonference and diameter of a circle is the same number as the limit of a few series, but calculating an aproximation of the first or some term of the second won't help much in this demonstration.
If the attacker knows that the plaintext is ASCII-encoded English, but the key is as long as the text you're going to have all of the possible ASCII-encoded English texts as possible original messages.
If, on the other side, you know that the plaintext is ASCII-encoded English in a valid compressed file, some possible English text are no longer possible as original message.
The perfect secrecy of OTP is based on the facts that you quoted, but also on the fact that you have the greatest (useful) keyspace.
I think that's because IE uses a default stylesheet for xml documents, while Mozilla strictly complies to the standard and just shows the contents of the tags, without any style.
It may tell something about the entropy of the original message, and anyway it will tell you that among all of the possible messages with the given lenght (the one encrypted message) not all of them are valid "possible original messages", but only a subset. It may be little information, but mathematically enought to say it's no longer unbreakable.
If it gives you any sort of information on the original message, other than its lenght, the system is no longer mathematically secure. Still reasonabily secure, but then there are lots of reasonabily secure encryption systems that are easier to use (expecially for key transmission).
It would be no longer mathematically unbreakable. Of course, if the message is a few TB long your method won't compromise much, but it won't help you transmitting the key, either; on the other side if your message is 8 bit long a 7 bit keys will compromise almost everything.
even a simple variant (compressing the plaintext then using OTP) requires less key data
Yes, but then you have some information on what the original text could have been, as it should be a valid [insert compression program] file. The reason why OTP is unbreakable is that if you try to attack it by brute force you'll have all of the possible messages of the same lenght, and you'll have no clue about which one is the real one. On the other side, if you compress the text and then apply brute force, you'll have all of the possible files of that lenght, but only a small part of them will be valid compressed files and this may help finding the real message.
I think that the actual proof works more or less in the same way: if the key is random, and exactly the same size of the text you get every possible message, even with bruteforce, if the key is shorter there are more chances that you'll be able to find some pattern in the cryptogram that will help you to decifrate it, and anyway with bruteforce you'll get only a subset of the possible messages, so that you may have a clue on what the real message was.
Of course this is required to have a really unbreakable system, mathematically proof: ohter systems may be statistically unbreakable, either because you need lots of time to decipher the messages, or because with brute force you may not get all of the messages of the same lenght, but you'll get enough to have really small chanches to find out the real one. Those will work just fine for most needs, like Amazon etc.
Valhalla is from norse mythology, I can't remember whether Limbo originated as a christian or an ebraic concept, but it is the upper part of hell in Dante's Divina Commedia. The place you call Limbo was called Hel in norse mythology.
Either the connection lies in the fact that they're both afterlives, or it lies in some modern work of literature.
Anyway I don't think that Limbo is a good name for a release, as I wouldn't feel like using something named after the most boring place of the whole afterlife: maybe somebody in the commercial department asked for a new release earlier than the developers felt it would be needed, so they just named that way.
what exactly is the anti-bacterial agent in these products? [...] bleach?
Is it possible that some bacteria gets resistant even to bleach and similar? I suppose they're harder to resist than antibiotic, as the latter should be safe enough to be used inside a living being without much damage, but I seem to remember that there are some bacteria able to resist unfriendly environments like boiling water for a while.
If this is the case, even anti-bacterial stuff may become "dangerous", given enough time.
With current technology it is extremely unlikely, although possible, that a mathematician would refute the hypothesis, but it is impossible for a computer to prove it.
While a mathematician can't try some random still untested number and hope to get the "right" one (all of the "small" numbers have been tried), he could always try and build some "special" class of numbers that could refuse the hypothesis and test those, or he could find some logical contradiction etc.
On the other side, with current technology computers can only try more and more cases, so that if the hypothesis is false they eventually find an example, but they just can't try every number (not in a finite time:) ), nor actually prove a theorem by logical means.
I know that somebody is researching some theorem-proving capable AI, but it seems that they didn't succeed yet in proving whether it can exist or not, so it will be quite some time before those could be available, if ever.
The problem is that in some parts of the world the term "Sellotape" has already been diluted, and is commonly used to talk about "Scotch Tape", even in some work of literature (by Douglas Adams for sure, probably others).
Had they done this way since the beginning it would have been their right, but now it seems to be too late. It seems that they enjoied the spreading of the word in common use when it gave them good publicity, and now that they're well known they begin protecting their name. Looks like what some software house did with the so called piracy.
In Italy we use scotch, and I think that most of the people don't know whether it is a generic name or a trademark.
Given the law, I'm afraid that they can't do anything but try to persecute anyone who uses that name or loose the rights to it: more a problem of bad law that single companies.
I know that the 4cd sale version of Slackware Linux comes with a "Bootable live disc, the Ultimate Linux rescue and demo disc!" (as they describe it on the website). I've never actually tried it, but I've never had problems with slackware products.
When you use something that belongs to someone else you have either to accept the conditions of the owner or stop using it. When you write software you have the right to keep your own work for yourself, or choose how it can be distributed and or used, at least to a certain degree.
If someone choose to support open source/free software by writing some piece of software he has the right to decide that it has to remain open/free, and this is what the GPL is about.
Apart from the philosophical reasons, on which not everybody may agree, there are still the pratical advantages of open source over closed source: not only faster innovation from reducing the need to duplicate the work, but also improved security because of the check on the sources by many people. Maybe in this case the first part does not apply (as long as they only changed something here and there to let it work on their hardware), but the second does, as without source code you can't be sure that they didn't include some backdoor or undocumented feature to their own advantage.
Of course they wouldn't have to give the sources with every DishPVR, also because I don't think that the average buyer will ever need them, but have to give the full sources they've actually used to anybody who asks them, for moral, practical, and legal reasons.
The way they choose to give them is less important, as long as it's reasonable: the GPL requires them to be willing to send them via mail with no additional charge (except P&P etc.), but they're free to offer other ways (like their own ftp or similar) in the hope that none of their customers will ever need the mail alternative.
I think that GPUs (at least, nowadays) are too focused on the tasks they have to perform (working with relatively little polygons, applying a few "small" textures etc., all of this in a very short time) to be useful in a totally different task like animation, where you have to work with huge amount of polygons, with complex textures etc., even with special software.
You also have to add the fact that many GPUs have specialyzed "special effects" built in, like light effects and similar stuff that may look great in a game, but are totaly useless in a movie, as they would be too standard and not-so-effective, so you will only be able to use the standard features of your GPU and still use the CPU for most of the work on special effects etc.
Even worse, video cards are more and more focused on speed rather than quality, and this is not going to help when making a movie.
Of course they could have some board specifically designed for the tasks they need, and this would surely improve the time needed to render a movie, but I'm not so sure whether it would be worth the cost.
With lindows they're trying to convince people to migrate from win to linux by changing the os first, and then your apps: I believe that this is the wrong way to do so, at least in most cases.
In my opinion it would be way better to begin with apps, substituting the ones you use most with alternatives available under various OS, so that you also get conscious of the difference between OS and applications, then when you're used to write your letters with, say, OpenOffice instead of MS Office and browsing with Mozilla instead of IE, switching to a different OS can be really painless, be it Linux, MacOSX, or anything else with some decent GUI.
The only problems you can have are with some specific apps for which there aren't linux (MacOSX, etc.) equivalents (but you can use a dual boot machine for those, or have someone install something like wine or vmware on your box) or even worse those legacy dos programs that you absolutely need for your work, but that won't work under any emulator because they use some tricky direct hardware access (but then you're going to have them rewritten anyway, as they won't work on recent version of windows either).
The only problem with Debian is that it is a little too hard to install and configure, even for some more-than-average users.
Lindow's target is quite different from Debian's one.
Anyway, there are lots of distros who are easyer than Debian, like Mandrake, that can be used by any user, and I'm afraid that they work way better than lindows.
I've been able to know about the next windows BUI (Body User Interface), directly from their ultra secret research labs!
First of all, the next windows version will not recognise keyboards, mice, touchpads etc., as they're obsolete devices, that the new generation of win-users should gladly forget.
Of course, a virtual keyboard will be included for compatibility issues, only it will be hidden, so that the average user will never be able to find it.
The hardware device used in this interface will be a full set of position sensor that the user should put on his body, each of them connected to the computer via his own wire; user will have to stand in front of a huge monitor and move all of his body to send commands.
The software interface will be an unlimited 3d space, of course, with an avatar of each user connected to the system ad well as small 3d "icons" of each program available: users will have to grab the icon to launch the program, or to kick them to see an alternate menu (right click-like) or to hit them with the head to select them for other reasons.
Common windows commands will have their shortcuts, with a triple somersault being "shutdown", scratching your armpit being "close" and of course what on some unices is called three fingers salute will be achieved with one (the) finger only, and will allow you to log in, to log out, to check for unstable programs, to shutdown, etc. etc.
You should add exactly what you mean with "source code": i think that this is a (slight) modification of the GPL.
Of course you won't change the spirit of the license, but only some detail, expecially if you choose the definition of "transparent copy" from the FDL as a definition of "source" for the images.
In my opinion you should consider this: your software can be used without the images or with different images?
If this is the case I believe that different licensing (software is GPL, artwork is XYZ) is just fine, on the contrary, if the actual images are an important part in the project, and it would be impossible (or very hard) to make a modified version of the program whithout manipulating the images you shoud have them under some GPL compatible licenze, either an adapded GPL or a FDL.
To copy a CD in an iso image under Linux it is enough to use dd(1) (dd if=/dev/cdrom of=filename.iso) or readcd(1) (should come with cdrecord) (and then mount them loopback): this is going to work also with some copy protected CDs, but not all of them.
Slashdot Mirror
So, you've just demonstrated that it's not only cars, but also computers that work better without windows :)
Sorry, I couldn't resist the temptation
I think it is a modern developement: in ancient times people actually believed that one could write everything about a subject without leaving anything, probably also because in most disciplines people knew much less than we do today (and as a matter of fact many people succeded in gaining an almost complete knowdlege of disparate disciplines, without our need to specialize).
Another possible reason is that we consider books to be a way to communicate ideas between contemporary people, so that knowdlege can be shared and used; in ancient times I believe that books were meant more for posterity than for their contemporaries, as most people who studied some subject tended to live in the same place (Alexandria, in a certain period), so they probably foud easier to share their knowdlege between themselves orally.
The article isn't much clear about the actual speed: it is 3 megabytes per second (usually written MBps) or 3 megabit per second (Mbps, as they wrote)? I believe that usually connection speed is measured in Mbps (bits, not bytes), but they may have different habits...
I seem to remember that all of the math books we have from the "Greeks" (actually, people from the east costs of the Mediterranean who happended to use some greek dialect for commercial and cultural exchanges) were meant to show results, not problems: most of them are some sorts of summae where somebody expose everything that is known about some subject, with more or less comments and precisations. Some of them actually include what probably were original results of the authors, but always as facts, not problems.
So, if we look back to greek times we can't have documented problems, but only problems that could have been asked with their knowdlege, expecially if it's similar to some problem they actually solved. If we accept this kind of problems, I believe that the existance of infinite perfect numbers could be a good candidate, as the Greek knew about them, and actually worried about the existence of infinite numbers of other kinds (prime, etc.).
If, on the other side, you want actual written documentation about the problem, I'm afraid that either we find some fragment of a letter written by some greek or arabian mathematician (quite unlikely) or we have to focus on renaissance.
Anyway, I'm not sure that problems with fibonacci numbers actually date to Fibonacci's era, as i seem to remember that they were only a small part of his work, and that they were extensively studied only later (by some 1800 French matematician?)
As far as I know pi is just a number: it exists and it has his own value, like 666, sqrt(2), e, i, etc.
I suppose that the main reason why it has a name is that lots of geometrical constant happen to belong to Q(pi) (i.e. the minimal subfield of the complex field that contains all rational numbers and pi); since Q(pi) is also an (infinite dimensional) vector space on Q, and most of the useful constant belongs to the subspace generated by 1 and pi, we can just write them as a*1+b*pi and we're able to work with them in an easier way.
The "definition of pi" is just like the definition of any other real number, as a Dedekin section (not sure it's the name you use in english), and it happens not to say much about its value. Then when you have real numbers you can say whether two of them are the same or not, so you can demostrate that, e.g. the ratio between circonference and diameter of a circle is the same number as the limit of a few series, but calculating an aproximation of the first or some term of the second won't help much in this demonstration.
If the attacker knows that the plaintext is ASCII-encoded English, but the key is as long as the text you're going to have all of the possible ASCII-encoded English texts as possible original messages.
If, on the other side, you know that the plaintext is ASCII-encoded English in a valid compressed file, some possible English text are no longer possible as original message.
The perfect secrecy of OTP is based on the facts that you quoted, but also on the fact that you have the greatest (useful) keyspace.
I think that's because IE uses a default stylesheet for xml documents, while Mozilla strictly complies to the standard and just shows the contents of the tags, without any style.
It may tell something about the entropy of the original message, and anyway it will tell you that among all of the possible messages with the given lenght (the one encrypted message) not all of them are valid "possible original messages", but only a subset. It may be little information, but mathematically enought to say it's no longer unbreakable.
If it gives you any sort of information on the original message, other than its lenght, the system is no longer mathematically secure. Still reasonabily secure, but then there are lots of reasonabily secure encryption systems that are easier to use (expecially for key transmission).
It would be no longer mathematically unbreakable. Of course, if the message is a few TB long your method won't compromise much, but it won't help you transmitting the key, either; on the other side if your message is 8 bit long a 7 bit keys will compromise almost everything.
Yes, but then you have some information on what the original text could have been, as it should be a valid [insert compression program] file. The reason why OTP is unbreakable is that if you try to attack it by brute force you'll have all of the possible messages of the same lenght, and you'll have no clue about which one is the real one. On the other side, if you compress the text and then apply brute force, you'll have all of the possible files of that lenght, but only a small part of them will be valid compressed files and this may help finding the real message.
I think that the actual proof works more or less in the same way: if the key is random, and exactly the same size of the text you get every possible message, even with bruteforce, if the key is shorter there are more chances that you'll be able to find some pattern in the cryptogram that will help you to decifrate it, and anyway with bruteforce you'll get only a subset of the possible messages, so that you may have a clue on what the real message was.
Of course this is required to have a really unbreakable system, mathematically proof: ohter systems may be statistically unbreakable, either because you need lots of time to decipher the messages, or because with brute force you may not get all of the messages of the same lenght, but you'll get enough to have really small chanches to find out the real one. Those will work just fine for most needs, like Amazon etc.
Valhalla is from norse mythology, I can't remember whether Limbo originated as a christian or an ebraic concept, but it is the upper part of hell in Dante's Divina Commedia. The place you call Limbo was called Hel in norse mythology.
Either the connection lies in the fact that they're both afterlives, or it lies in some modern work of literature.
Anyway I don't think that Limbo is a good name for a release, as I wouldn't feel like using something named after the most boring place of the whole afterlife: maybe somebody in the commercial department asked for a new release earlier than the developers felt it would be needed, so they just named that way.
Is it possible that some bacteria gets resistant even to bleach and similar? I suppose they're harder to resist than antibiotic, as the latter should be safe enough to be used inside a living being without much damage, but I seem to remember that there are some bacteria able to resist unfriendly environments like boiling water for a while.
If this is the case, even anti-bacterial stuff may become "dangerous", given enough time.
With current technology it is extremely unlikely, although possible, that a mathematician would refute the hypothesis, but it is impossible for a computer to prove it.
While a mathematician can't try some random still untested number and hope to get the "right" one (all of the "small" numbers have been tried), he could always try and build some "special" class of numbers that could refuse the hypothesis and test those, or he could find some logical contradiction etc.
On the other side, with current technology computers can only try more and more cases, so that if the hypothesis is false they eventually find an example, but they just can't try every number (not in a finite time :) ), nor actually prove a theorem by logical means.
I know that somebody is researching some theorem-proving capable AI, but it seems that they didn't succeed yet in proving whether it can exist or not, so it will be quite some time before those could be available, if ever.
The problem is that in some parts of the world the term "Sellotape" has already been diluted, and is commonly used to talk about "Scotch Tape", even in some work of literature (by Douglas Adams for sure, probably others).
Had they done this way since the beginning it would have been their right, but now it seems to be too late. It seems that they enjoied the spreading of the word in common use when it gave them good publicity, and now that they're well known they begin protecting their name. Looks like what some software house did with the so called piracy.
In Italy we use scotch, and I think that most of the people don't know whether it is a generic name or a trademark.
Given the law, I'm afraid that they can't do anything but try to persecute anyone who uses that name or loose the rights to it: more a problem of bad law that single companies.
I know that the 4cd sale version of Slackware Linux comes with a "Bootable live disc, the Ultimate Linux rescue and demo disc!" (as they describe it on the website). I've never actually tried it, but I've never had problems with slackware products.
When you use something that belongs to someone else you have either to accept the conditions of the owner or stop using it. When you write software you have the right to keep your own work for yourself, or choose how it can be distributed and or used, at least to a certain degree.
If someone choose to support open source/free software by writing some piece of software he has the right to decide that it has to remain open/free, and this is what the GPL is about.
Apart from the philosophical reasons, on which not everybody may agree, there are still the pratical advantages of open source over closed source: not only faster innovation from reducing the need to duplicate the work, but also improved security because of the check on the sources by many people. Maybe in this case the first part does not apply (as long as they only changed something here and there to let it work on their hardware), but the second does, as without source code you can't be sure that they didn't include some backdoor or undocumented feature to their own advantage.
Of course they wouldn't have to give the sources with every DishPVR, also because I don't think that the average buyer will ever need them, but have to give the full sources they've actually used to anybody who asks them, for moral, practical, and legal reasons.
The way they choose to give them is less important, as long as it's reasonable: the GPL requires them to be willing to send them via mail with no additional charge (except P&P etc.), but they're free to offer other ways (like their own ftp or similar) in the hope that none of their customers will ever need the mail alternative.
I think that GPUs (at least, nowadays) are too focused on the tasks they have to perform (working with relatively little polygons, applying a few "small" textures etc., all of this in a very short time) to be useful in a totally different task like animation, where you have to work with huge amount of polygons, with complex textures etc., even with special software.
You also have to add the fact that many GPUs have specialyzed "special effects" built in, like light effects and similar stuff that may look great in a game, but are totaly useless in a movie, as they would be too standard and not-so-effective, so you will only be able to use the standard features of your GPU and still use the CPU for most of the work on special effects etc.
Even worse, video cards are more and more focused on speed rather than quality, and this is not going to help when making a movie.
Of course they could have some board specifically designed for the tasks they need, and this would surely improve the time needed to render a movie, but I'm not so sure whether it would be worth the cost.
With lindows they're trying to convince people to migrate from win to linux by changing the os first, and then your apps: I believe that this is the wrong way to do so, at least in most cases.
In my opinion it would be way better to begin with apps, substituting the ones you use most with alternatives available under various OS, so that you also get conscious of the difference between OS and applications, then when you're used to write your letters with, say, OpenOffice instead of MS Office and browsing with Mozilla instead of IE, switching to a different OS can be really painless, be it Linux, MacOSX, or anything else with some decent GUI.
The only problems you can have are with some specific apps for which there aren't linux (MacOSX, etc.) equivalents (but you can use a dual boot machine for those, or have someone install something like wine or vmware on your box) or even worse those legacy dos programs that you absolutely need for your work, but that won't work under any emulator because they use some tricky direct hardware access (but then you're going to have them rewritten anyway, as they won't work on recent version of windows either).
The only problem with Debian is that it is a little too hard to install and configure, even for some more-than-average users.
Lindow's target is quite different from Debian's one.
Anyway, there are lots of distros who are easyer than Debian, like Mandrake, that can be used by any user, and I'm afraid that they work way better than lindows.
I've been able to know about the next windows BUI (Body User Interface), directly from their ultra secret research labs!
First of all, the next windows version will not recognise keyboards, mice, touchpads etc., as they're obsolete devices, that the new generation of win-users should gladly forget.
Of course, a virtual keyboard will be included for compatibility issues, only it will be hidden, so that the average user will never be able to find it.
The hardware device used in this interface will be a full set of position sensor that the user should put on his body, each of them connected to the computer via his own wire; user will have to stand in front of a huge monitor and move all of his body to send commands.
The software interface will be an unlimited 3d space, of course, with an avatar of each user connected to the system ad well as small 3d "icons" of each program available: users will have to grab the icon to launch the program, or to kick them to see an alternate menu (right click-like) or to hit them with the head to select them for other reasons.
Common windows commands will have their shortcuts, with a triple somersault being "shutdown", scratching your armpit being "close" and of course what on some unices is called three fingers salute will be achieved with one (the) finger only, and will allow you to log in, to log out, to check for unstable programs, to shutdown, etc. etc.
Resistance is futile. :)
You should add exactly what you mean with "source code": i think that this is a (slight) modification of the GPL.
Of course you won't change the spirit of the license, but only some detail, expecially if you choose the definition of "transparent copy" from the FDL as a definition of "source" for the images.
In my opinion you should consider this: your software can be used without the images or with different images?
If this is the case I believe that different licensing (software is GPL, artwork is XYZ) is just fine, on the contrary, if the actual images are an important part in the project, and it would be impossible (or very hard) to make a modified version of the program whithout manipulating the images you shoud have them under some GPL compatible licenze, either an adapded GPL or a FDL.
To copy a CD in an iso image under Linux it is enough to use dd(1) (dd if=/dev/cdrom of=filename.iso) or readcd(1) (should come with cdrecord) (and then mount them loopback): this is going to work also with some copy protected CDs, but not all of them.