Living close to Hamburg, I am considering driving there and buying such a thing.
But I think the *really* big obstacle in adoption are people with these problems:
- Why do we need it, we have already DSL/analog modem/ISDN? - But if the network doesn't work, which number should I dial? - Isn't RF dangerous? - Where are the hidden costs? It must cost something! - My provider gives 'my internet with many colors and sound and multimedia'. I doubt you bunch of geeks can provide such a thing!
And so forth. *SIGH*
Oh yeah, and there is the liability issue, as providers are considered an arm of law enforcement nowadays...
Re:The silver lining in the falling sky...
on
P2P Bits
·
· Score: 1
Interesting concept, but I think there are several problems: 1. Because of 1/(r^2) decay of power density, the distance power equations are nonlinear and you'd need a higher dynamical range A/D converter. With sound measurement, you'd use the delay which is directly proportional to distance.
2. You have interference patterns, reflections etc. which seriously alter the power you measure. With ultrasonic measurement, you'd have them too, but you could easily mask the reflection out because it is feasible to do time measurements and modulate the sound signal.
Maybe it would be possible to do it with RF if you 'learn' the interference pattern and correct your position measurements with it. But what would be the advantage? I don't think that RF is simpler to implement/use than sound transmitters/receivers. If you do some signal processing, you can maybe even use some ordinary speakers and microphones.
1. A _safe_ mowing method as you describe 2. The position measurement could be done with (ultra)sonic sensors and a transmitter on the mower. Doesn't work if you have to change garden often. 3. A power and communication cable. Can be cheap because of low power requirements because of 1. 4. A tower from where the cable goes to the mower and a mechanism to ensure that the cable doesn't get in the way.
Of course there is no obstacle avoidance etc., but I would start such a project in a modest size, not with all the 1000 features which _could_ be implemented!
As I'm doing such things also (Homemade microcontroller applications are everywhere in my home), I would say that it is far better to have a little thing working than big plans for a big thing but get nothing implemented.
Opensourcing them would be a problem, since it'll allow people to find weaknesses more easily and forge results, so they get a better rating
Interesting. As we all know, in the context of security, OSS is considered better because it is viewed by many eyes and holes are noticed easily.
In this context, it could be the same if the number of people who care about correct scores look at the source. Maybe it is possible to design it in a way where it can be tested if a user just sends "I'm ready" back.
IMHO, they're already doing it by comparing the results of different users who get equal workunits.
No, why? Because it (the application) uses networking and is 'distributed'? It is not p2p. It is 1-N, i.e. the workunit server to all the clients. That's a bigg difference. Although you can argue that there is a single point of failure because the workload server could be hacked and transfer malicous data to the clients, it is a scenario IMHO not very likely because: a) the workload server has to be hacked, b) it has to stay so for a longer time to have any effect and c) the client software must have a buffer-overflow-like flaw.
Set it in relation: If you do apt-get in debian without *really* checking the author's reputation and getting his *certified* PGP/GPG keys, you're essentially doing much worse things in terms of security. Probably 95% of all debian users do this (me included).
And it is similar to websites which install worms by exploiting flaws in IE. This is a way of infection which has to be blocked, of course, but the main way of infection is still either by unpatched services running on well-known ports or eMail...
This is, of course, one of the reasons why I won't use SETI@Home until it is GPL or similar [Would it be GPL with BOINC?]
Once there was a proposal for binary XML in the context of cellphone WAP, but it disappeared quickly...
I only hope that that implement/define it in a way which supports mmap()ing, then there are really no obstacles in using it, maybe even on for a systemwide filesystem:)
Sure, XML is nice to represent hierarchical structures ("filesystem in a file" - like the old IFF for Amiga). A good idea for the web, for office documents etc.
But XML does not provide information about how to interpret a document (only how to parse/validate it formally or render it in certain, rather special circumstances). The logic to work with and interpret the data still has to be implemented somewhere... interoperability goes only so far as to the representation of the document's structure.
XML is text (Which is IMHO very sad - I'm longing for a binary XML, that would be cool:) and therefore: 1. binary data has to be encoded/decoded, at least extracted, what really is missing is fast mmap()ed access to the data. 2. text is inefficiently transmitted/stored, unless you compress it, then you have CPU inefficiency.
So what really is the advantage that let the researchers choose this over a binary format like HDF? I'm curious, not trolling.
I also use SpamAssassin and I think it got a bit overtrained on commercial advertisements and scams, i.e. viagra, nigeria, xanax & Co.
Has anyone besides me noticed that shortly before the european elections took place, very nasty POLITICAL spam got through? No, I don't mean "vote for me and not for him"-type of spam. I mean very right-wing, I'd say nazi spam.
The only spam I'm getting at the moment is this nazi spam (It seems not to be closely related to the elections because it is still send) and I have a hard time to convice SpamAssassin that it is indeed spam...
I recently heard that the power required to generate the earth's magnetic field (i.e. run the "core" dynamo) is only about 1 terawatt (not 100, as it was previously estimated).
1 terawatt is not too much. A decent nuclear plant produces 1.5GW, i.e. 0.0015TW. So it should be possible to power a mars magnetic field with 100 scaled up reactors? Ok, that's _expensive_. But not completely unimaginable!
First of all: You can't win (or have already won) an argumenst over VMs. This would be not C++Java but C++VM. Silly comparison, take a C++->JVM compiler! Now, a bit more detailed:
[Bubblesort/Quicksort-Comparison] Do you think, that, in C++, a quicksort() is impossible or needs serious brain-twisting? It's as easy as in Java... As we all know, BS is O(n^2) and QS is O(n log n) in the average case... but this is simply no argument.
[Efficiency and the big picture] Here you're somehow assuming that you have to stay on a lower level with C++ than with Java. Know what? Want to get really high-level? Do not choose C++/Java, use Lisp(Scheme) or Haskell.
[Other JVM specific anti C++-rants] See above. That's the JVM, not the language. Although all your arguments for JVMs are (theoretically) true, I have yet to see a JVM implementation that outperforms C++. One of the reason why C++ still gets compiled to native code, I think. Please don't get me into an argument here why the JVM is IMHO not very well designed for perfomance.
[Memory management] Garbage collection is available by using external libraries in C++. A VM implementation would certainly contain such a garbage collection library.
And no, if you do write C++ and _NOT C_, you'd hide all of the memory management stuff in proper classes. (The idea of "resource initization == resource allocation")
[Design level of Java] Sorry, but if you think of C++ only as a 'better C', you really don't know C++. C++ plays easily on the same level as Java.
Uh, no. Java != JVM. That's the point. A C++ compiler with a JVM backend and your argument is moot. AND with C++ you have the advantage of using it for lower level things.
Simple solution. Use a VM (maybe the JVM) for C++. Whoosh, the problem goes away. As another poster stated: "Were' comparing compilers/VMs, *not* languages.".
And, because you can go to lower levels with C++, I'll assure you that'll beat java every time you give it equal conditions.
Why, oh, why is C++ ALWAYS COMPARED TO ASSEMBLER?!
C++ is at least as poweful and expressive as java. Java is C++ dumbed down and with a nice and fairly complete class library. And no, (I hear this often), Java is not preceding C++ historically, the C++ _standard_ came later than the first versions of Java.
But C++ is not assembler. C++ has a high dynamical range. Use it for assembly-like tasks, e.g. kernel programming, use it for writing your traffic control, expert system, whatever.
It is a general purpose language.
I do both, C++ and Java, and although Java has adavantages (mainly, the platform to run the programs is readily on nearly every computer - But with C++ one does 'write once, compile everywhere' nowadays with boost and similar libraries), the programming language forces the programmer to do various things considered "better for him/her".
Heh, it's funny, just yesterday, Bjarne Stroustrup himself gave a lecture at our university!
He spoke *a lot* about 'efficiency', and IMHO, he did have a valid point. He compared C++ to C and FORTRAN and made good arguments why C/Fortran is slower than highly optimized C++ code nowadays (Because of the amount of information a C++ compiler can collect about the program's structure... in C everything is flattened to a low level by the programmer already and information is lost for the compiler).
Asked after his lecture if there are plans for a virtual machine for C++ (as an *alternative* to native code), Mr. Stroustrup strongly denied that. I think this is one of the more important reasons why Java is considered 'better' by many people. Because it *seems* that, with the VM, it's more portable. There is clearly not engineering reason for a C++ VM, but politically, it would give C++ the opportunity to gain ground against Java.
You have to, of course, use appropiate C++ paradigms, like templates emulating lazy evaluation etc. A "naive" matrix class in C++ is nice to write, but not very efficient to use.
Even if you cry out loud that efficiency doesn't matter any more, it's, at least somewhat, wrong. It's an arrogance of the programmers against the users of their programs. If one programmer saves 10 hours of time but for each user, using the program takes 10min longer (be it startup times or whatever), it's time-inefficient if only 100 people are using the program. And you have to take into account that the time of the users adds up more easily than that of the programmers. They're probably not running the program once, but multiple times...
Of course, java has it's uses, e.g. client-side interfaces running in the browser.
But the argument, stated over and over again, that Java is/can be faster because of runtime optimizations, is *really* flawed and just ignoring facts. There are compilers which can do optimizations on profiling data from the actual running program. Beat that java. A compiler tailored to the machine *and* the beloved runtime optimizations.
...while the computing power of a few hundred real qbits might be impressive, the computing power required to simulate those few hundred qbits would be extremely impressive.
Well, if you count quantum computing as computing, you can easily simulate a few hundred qbits by the identity map onto the quantum computer itself;)
Maybe you think "it's easy to say that now", but I already know at the time of posting this that moore s law covers processor density.
I did a talk about the physics of field effect transistors, esp. MOSFETs just yesterday. So, I probably know what I'm talking about, at least more than the avg./. crowd, but why bother...:)
Hey, that's amazing! Here in germany, all people are either simply opponents of technology, or, at the best, computers are for writing texts, internet is for looking up train connections and selling/buying at ebay. Every other usage is probably 'hackerish' and therefore bad.
I never went to australia, but I have this prejudice that you're all living on ranches with several kilometers in between:)
But I think, in densely populated areas, there is also nothing that prevents mesh networks from taking off other than computer/networking illiteracy/ignorance. I'm dreaming of free space optical (FSO) from roof to roof since I know of the structure of the internet. But if only 1% of the population shares the enthusiasm to build and run such networks (Knowledge of the protocols wouldn't even be needed with modified, plug'n'play linksys routers or similar, just enthusiasm), there is no chance that such a thing will be built in the near future...
Is this the end of moores law, at least in the form of CPU speeds doubling every 18 months? There are essentially two CPUs, I doubt each of them will get 2x faster the next 1.5 years:)
You're confusing two things. First, you have disk (or let's rather say, mass media) cache which is managed by your linux kernel. It uses your computers RAM which sits on the mainboard (usually). Second, you have cache memory (also RAM), which is *in the disk drive* itself. More of that can never hurt because it won't use up your main memory.
Sorry for stating that so explicitely, but your comment really force me to write it down that way.
Slashdot Mirror
Living close to Hamburg, I am considering driving there and buying such a thing.
But I think the *really* big obstacle in adoption are people with these problems:
- Why do we need it, we have already DSL/analog modem/ISDN?
- But if the network doesn't work, which number should I dial?
- Isn't RF dangerous?
- Where are the hidden costs? It must cost something!
- My provider gives 'my internet with many colors and sound and multimedia'. I doubt you bunch of geeks can provide such a thing!
And so forth. *SIGH*
Oh yeah, and there is the liability issue, as providers are considered an arm of law enforcement nowadays...
The genie's out, ...
Funny that you describe it this way.
Have you read the paper
The Digital Imprimatur - How big brother and big media can put the Internet genie back in the bottle
?
Of course, I also hope that there will be a backslash. But I'm not too optimistic.
Interesting concept, but I think there are several problems:
1. Because of 1/(r^2) decay of power density, the distance power equations are nonlinear and you'd need a higher dynamical range A/D converter. With sound measurement, you'd use the delay which is directly proportional to distance.
2. You have interference patterns, reflections etc. which seriously alter the power you measure.
With ultrasonic measurement, you'd have them too, but you could easily mask the reflection out because it is feasible to do time measurements and modulate the sound signal.
Maybe it would be possible to do it with RF if you 'learn' the interference pattern and correct your position measurements with it.
But what would be the advantage? I don't think that RF is simpler to implement/use than sound transmitters/receivers. If you do some signal processing, you can maybe even use some ordinary speakers and microphones.
Be honest and advertise the original Astroturf product :)
Yes, I would implement the following:
1. A _safe_ mowing method as you describe
2. The position measurement could be done with (ultra)sonic sensors and a transmitter on the mower. Doesn't work if you have to change garden often.
3. A power and communication cable. Can be cheap because of low power requirements because of 1.
4. A tower from where the cable goes to the mower and a mechanism to ensure that the cable doesn't get in the way.
Of course there is no obstacle avoidance etc., but I would start such a project in a modest size, not with all the 1000 features which _could_ be implemented!
As I'm doing such things also (Homemade microcontroller applications are everywhere in my home), I would say that it is far better to have a little thing working than big plans for a big thing but get nothing implemented.
Opensourcing them would be a problem, since it'll allow people to find weaknesses more easily and forge results, so they get a better rating
Interesting. As we all know, in the context of security, OSS is considered better because it is viewed by many eyes and holes are noticed easily.
In this context, it could be the same if the number of people who care about correct scores look at the source. Maybe it is possible to design it in a way where it can be tested if a user just sends "I'm ready" back.
IMHO, they're already doing it by comparing the results of different users who get equal workunits.
No, why?
Because it (the application) uses networking and is 'distributed'? It is not p2p. It is 1-N, i.e. the workunit server to all the clients. That's a bigg difference. Although you can argue that there is a single point of failure because the workload server could be hacked and transfer malicous data to the clients, it is a scenario IMHO not very likely because: a) the workload server has to be hacked, b) it has to stay so for a longer time to have any effect and c) the client software must have a buffer-overflow-like flaw.
Set it in relation:
If you do apt-get in debian without *really* checking the author's reputation and getting his *certified* PGP/GPG keys, you're essentially doing much worse things in terms of security. Probably 95% of all debian users do this (me included).
And it is similar to websites which install worms by exploiting flaws in IE. This is a way of infection which has to be blocked, of course, but the main way of infection is still either by unpatched services running on well-known ports or eMail...
This is, of course, one of the reasons why I won't use SETI@Home until it is GPL or similar [Would it be GPL with BOINC?]
Yes. Thank you! That's indeed interesting. Nice.
:)
Once there was a proposal for binary XML in the context of cellphone WAP, but it disappeared quickly...
I only hope that that implement/define it in a way which supports mmap()ing, then there are really no obstacles in using it, maybe even on for a systemwide filesystem
What I don't understand are the advantages here.
:) and therefore:
Sure, XML is nice to represent hierarchical structures ("filesystem in a file" - like the old IFF for Amiga). A good idea for the web, for office documents etc.
But XML does not provide information about how to interpret a document (only how to parse/validate it formally or render it in certain, rather special circumstances). The logic to work with and interpret the data still has to be implemented somewhere... interoperability goes only so far as to the representation of the document's structure.
XML is text (Which is IMHO very sad - I'm longing for a binary XML, that would be cool
1. binary data has to be encoded/decoded, at least extracted, what really is missing is fast mmap()ed access to the data.
2. text is inefficiently transmitted/stored, unless you compress it, then you have CPU inefficiency.
So what really is the advantage that let the researchers choose this over a binary format like HDF? I'm curious, not trolling.
I also use SpamAssassin and I think it got a bit overtrained on commercial advertisements and scams, i.e. viagra, nigeria, xanax & Co.
Has anyone besides me noticed that shortly before the european elections took place, very nasty POLITICAL spam got through?
No, I don't mean "vote for me and not for him"-type of spam. I mean very right-wing, I'd say nazi spam.
The only spam I'm getting at the moment is this nazi spam (It seems not to be closely related to the elections because it is still send) and I have a hard time to convice SpamAssassin that it is indeed spam...
I recently heard that the power required to generate the earth's magnetic field (i.e. run the "core" dynamo) is only about 1 terawatt (not 100, as it was previously estimated).
1 terawatt is not too much. A decent nuclear plant produces 1.5GW, i.e. 0.0015TW.
So it should be possible to power a mars magnetic field with 100 scaled up reactors?
Ok, that's _expensive_. But not completely unimaginable!
Improbable. Tastes are different.
See, FORTRAN is still around. And new/updated compilers are released every year...
That's how you win, you take Microsoft's strongest weapon away - the masses of developers.
:)
I already hear ballmer screaming: "Developers, developers, developers. Developers, developers, developers..."
Or is yet another case where the city is more progressive that the (rural) areas arround?
Yes.
Bavaria itself is CSU governed and will, IMHO, stay so for some years to come...
The bavarian city munich is traditionally SPD governed.
First of all: You can't win (or have already won) an argumenst over VMs. This would be not C++Java but C++VM. Silly comparison, take a C++->JVM compiler!
Now, a bit more detailed:
[Bubblesort/Quicksort-Comparison]
Do you think, that, in C++, a quicksort() is impossible or needs serious brain-twisting? It's as easy as in Java...
As we all know, BS is O(n^2) and QS is O(n log n) in the average case... but this is simply no argument.
[Efficiency and the big picture]
Here you're somehow assuming that you have to stay on a lower level with C++ than with Java. Know what? Want to get really high-level? Do not choose C++/Java, use Lisp(Scheme) or Haskell.
[Other JVM specific anti C++-rants]
See above. That's the JVM, not the language. Although all your arguments for JVMs are (theoretically) true, I have yet to see a JVM implementation that outperforms C++. One of the reason why C++ still gets compiled to native code, I think.
Please don't get me into an argument here why the JVM is IMHO not very well designed for perfomance.
[Memory management]
Garbage collection is available by using external libraries in C++. A VM implementation would certainly contain such a garbage collection library.
And no, if you do write C++ and _NOT C_, you'd hide all of the memory management stuff in proper classes. (The idea of "resource initization == resource allocation")
[Design level of Java]
Sorry, but if you think of C++ only as a 'better C', you really don't know C++. C++ plays easily on the same level as Java.
Theoretically *AND* practically, you're wrong.
1. Theoretically, the JVM is equivalent to a finite turing machine and thus able to run C++ code.
2. There exists such a beast already (but is sadly not up to date and only a small prototype!).
See here:
Java backend for EGCS.
3. There is mips2java which converts GCC mips backend code to the java virtual machine. Google yourself. But this is a kludge, albeit a nice one.
Uh, no. Java != JVM.
That's the point. A C++ compiler with a JVM backend and your argument is moot. AND with C++ you have the advantage of using it for lower level things.
Simple solution. Use a VM (maybe the JVM) for C++. Whoosh, the problem goes away. As another poster stated: "Were' comparing compilers/VMs, *not* languages.".
And, because you can go to lower levels with C++, I'll assure you that'll beat java every time you give it equal conditions.
Why, oh, why is C++ ALWAYS COMPARED TO ASSEMBLER?!
C++ is at least as poweful and expressive as java. Java is C++ dumbed down and with a nice and fairly complete class library. And no, (I hear this often), Java is not preceding C++ historically, the C++ _standard_ came later than the first versions of Java.
But C++ is not assembler. C++ has a high dynamical range. Use it for assembly-like tasks, e.g. kernel programming, use it for writing your traffic control, expert system, whatever.
It is a general purpose language.
I do both, C++ and Java, and although Java has adavantages (mainly, the platform to run the programs is readily on nearly every computer - But with C++ one does 'write once, compile everywhere' nowadays with boost and similar libraries), the programming language forces the programmer to do various things considered "better for him/her".
Heh, it's funny, just yesterday, Bjarne Stroustrup himself gave a lecture at our university!
He spoke *a lot* about 'efficiency', and IMHO, he did have a valid point. He compared C++ to C and FORTRAN and made good arguments why C/Fortran is slower than highly optimized C++ code nowadays (Because of the amount of information a C++ compiler can collect about the program's structure... in C everything is flattened to a low level by the programmer already and information is lost for the compiler).
Asked after his lecture if there are plans for a virtual machine for C++ (as an *alternative* to native code), Mr. Stroustrup strongly denied that. I think this is one of the more important reasons why Java is considered 'better' by many people. Because it *seems* that, with the VM, it's more portable. There is clearly not engineering reason for a C++ VM, but politically, it would give C++ the opportunity to gain ground against Java.
You have to, of course, use appropiate C++ paradigms, like templates emulating lazy evaluation etc. A "naive" matrix class in C++ is nice to write, but not very efficient to use.
Even if you cry out loud that efficiency doesn't matter any more, it's, at least somewhat, wrong. It's an arrogance of the programmers against the users of their programs. If one programmer saves 10 hours of time but for each user, using the program takes 10min longer (be it startup times or whatever), it's time-inefficient if only 100 people are using the program. And you have to take into account that the time of the users adds up more easily than that of the programmers. They're probably not running the program once, but multiple times...
Of course, java has it's uses, e.g. client-side interfaces running in the browser.
But the argument, stated over and over again, that Java is/can be faster because of runtime optimizations, is *really* flawed and just ignoring facts. There are compilers which can do optimizations on profiling data from the actual running program. Beat that java. A compiler tailored to the machine *and* the beloved runtime optimizations.
...while the computing power of a few hundred real qbits might be impressive, the computing power required to simulate those few hundred qbits would be extremely impressive.
;)
Well, if you count quantum computing as computing, you can easily simulate a few hundred qbits by the identity map onto the quantum computer itself
Maybe you think "it's easy to say that now", but I already know at the time of posting this that moore s law covers processor density.
/. crowd, but why bother... :)
I did a talk about the physics of field effect transistors, esp. MOSFETs just yesterday. So, I probably know what I'm talking about, at least more than the avg.
Hey, that's amazing!
:)
Here in germany, all people are either simply opponents of technology, or, at the best, computers are for writing texts, internet is for looking up train connections and selling/buying at ebay. Every other usage is probably 'hackerish' and therefore bad.
I never went to australia, but I have this prejudice that you're all living on ranches with several kilometers in between
But I think, in densely populated areas, there is also nothing that prevents mesh networks from taking off other than computer/networking illiteracy/ignorance. I'm dreaming of free space optical (FSO) from roof to roof since I know of the structure of the internet. But if only 1% of the population shares the enthusiasm to build and run such networks (Knowledge of the protocols wouldn't even be needed with modified, plug'n'play linksys routers or similar, just enthusiasm), there is no chance that such a thing will be built in the near future...
Is this the end of moores law, at least in the form of CPU speeds doubling every 18 months? :)
There are essentially two CPUs, I doubt each of them will get 2x faster the next 1.5 years
You're confusing two things.
First, you have disk (or let's rather say, mass media) cache which is managed by your linux kernel. It uses your computers RAM which sits on the mainboard (usually).
Second, you have cache memory (also RAM), which is *in the disk drive* itself. More of that can never hurt because it won't use up your main memory.
Sorry for stating that so explicitely, but your comment really force me to write it down that way.