I was also wondering where this idea that a qubit has four states was coming from. It would be like saying there are four directions on a plane (north west south east) while of course there are an infinite number of them.
Actually I think the confusion comes from the fact that quantum cryptography (key exchange) is only using those four different states mentionned by L0phtpDK (btw that looks more like a password than a username are you sure you didn't swap them?:-)
What happens if an ant crawls into the box for example? Because it's not 'really' an observer the cat is still half alive??
Yes the cat is still half alive, and the ant is half seeing a dead cat and half seeing a cat alive. What happens when the ant walks in the box is that its state gets correlated to that of the cat.
Note that the either state of the ant is unaware of the other.
When you open the box you will either see a dead cat and an ant that has been seeing a dead cat all along, or a living cat and an ant that has been seeing a cat alive all along
Oh, and finally, there are many indirect but observable consequences of these superposition states, and they are precisely what quantum computing takes advantage of.
by the way, sorry I know this is off topic, but is anyone else having problems logging in in slashdot.org subdomains? That problem started for me a couple of weeks ago : I'm logged in slashdot.org but not in science.slashdot.org or it.slashdot.org etc so I can't mod in these domains unless I comment first
x-windows permits this - to have a process request to be the exclusive recipient of all keystrokes (no matter what window is selected). I don't know about os x.
But to my knowledge there are few programs that actually do it. I am aware of three: xterm - when you ctrl-click on the window you can ask for "secure keyboard" which does that. gpg-agent's passphrase request window can also activate that feature. And xscreensaver, when asking for your password to unlock the screen (other screensavers probably too)
One reason why you don't want to keep your xterm on "secure keyboard" all the time is that your screensaver can't detect keyboard activity anymore (and of course you can't type to other windows)
Sorry for nitpicking but it is not linear, but polynomial. Like the wikipedia page says it has the order O((log n)^3).
Secondly, saying it is "millions of times faster" does not really make sense. We don't measure the efficiency of an algorithm by the actual time it takes but by its complexity. It is likely that the first few quantum computer prototypes will be quite slow and may take longer than classical computers to factor small numbers (I don't know, like 20 digits). However it has a better complexity so: no matter how slow your quantum computer is, it will be faster than all the classical computers in the world once you feed them big enough numbers
You're right actually that should be seen as a bug of my browser (konqueror) - I checked the box "underline links only when mouse is over". It does force links not to be underlined when not hovered on but should also force links to be underlined when hovered on - I guess I should file that as a bug...
I maintain my complaint about the colours - one indicator of link (different colour/face/whatever) is enough for me - slashdot is the only site I know that only relies on the underline for distinguishing (visited) links from the text so it is the only one I know that causes problems with this setting. (There is no way for konq. to set exceptions for specific sites:-( ) Anyway that is not the end of the world I guess
I've one comment about that by the way - I configured my browser to hide the link underlining by default and show it again when I hover on the link (I think it looks nicer - for all websites except/.) so:
most websites give me this visual feedback you talk about. But I have no feedback at all on/.
Worse is that when a link is in already visited state its colour is black so I can't see at all that there is a link! I guess I should write my own css to override this but I've other things to do
if anybody responsible for this reads me please change the #visited colour to something other than black
A while ago xul-based pages was supposed to be the Next-Big-Thing. What happened to that? Is it being left behind because too few browsers are supporting it?
How does xul compare to ajax?
(Anyway neither is supported in konqueror so it's not like I care so much:-)
What about archiving along with the data the software that's able to read it? (i.e. the source code - looks like C is a format that's going to last for a while)
Downloading from any mirror, official or not is fine as long as you check the archive using md5 or sha1 (or ideally, gpg) from the main site, which provides signatures for every archive.
Though what I don't know is why mozilla doesn't insist more on that (you have to go on the ftp site clicking on "other systems" to find the checksums and signatures : ftp thunderbird)
Emacs shell mixes up too much command input and output to my taste... Then most shells (and every program using the readline library) support the Ctrl-R function to search through command history, just like emacs. For searching through command outputs there are terminal emulators like konsole that provide such functions... Check man readline you'll be surprised how much of emacs functionality you have in your daily shell!
They will "support" those open formats in a broken way and keep their own proprietary format. That will discourage users to choose those formats yet fulfill the requirement to support open formats. Alternatively they will interpret it in subtly different ways that make the saved document only usable in Word. (Think HTML and IE...)
It's amusing how "does it run Linux" for an article about windows would get modded +5 Funny and "does it run Windows" for an article about linux get modded -1 Troll:-)
I don't agree. What if you need to print a file on a printer that's on another workstation? What if you need to send a file to someone else? (E-mail? eek.)
Like everybody has already said, solutions to wireless security problems already exist. As for worm propagation, as long as one box can connect to the internet none of this is going to block it.
Slashdot Mirror
I was also wondering where this idea that a qubit has four states was coming from. It would be like saying there are four directions on a plane (north west south east) while of course there are an infinite number of them.
:-)
Actually I think the confusion comes from the fact that quantum cryptography (key exchange) is only using those four different states mentionned by L0phtpDK (btw that looks more like a password than a username are you sure you didn't swap them?
What happens if an ant crawls into the box for example? Because it's not 'really' an observer the cat is still half alive??
Yes the cat is still half alive, and the ant is half seeing a dead cat and half seeing a cat alive. What happens when the ant walks in the box is that its state gets correlated to that of the cat.
Note that the either state of the ant is unaware of the other.
When you open the box you will either see a dead cat and an ant that has been seeing a dead cat all along, or a living cat and an ant that has been seeing a cat alive all along
Oh, and finally, there are many indirect but observable consequences of these superposition states, and they are precisely what quantum computing takes advantage of.
by the way, sorry I know this is off topic, but is anyone else having problems logging in in slashdot.org subdomains? That problem started for me a couple of weeks ago : I'm logged in slashdot.org but not in science.slashdot.org or it.slashdot.org etc so I can't mod in these domains unless I comment first
I suspect your version of dc is too old (I have dc 1.3 and that code works fine for me)
141 is unimplemented: 141 is the 'a' command that converts a number into a character.
multiplication using a switch statement (switch (i){ case 1: n = 2; case 2: n = 4;...})
I think you got it wrong, your code always stores 4 into n. A proper way to do multiplication is as follows:
n=0;switch(i){case 4:n+=2; case 3:n+=2; case 2:n+=2; case 1:n+=2;} // this assumes i is positive and smaller than five of course.
Behold my shell script for generating random passwords.
:-)
How's that for clean readable code?
It does look like it contains a hardcoded password but it really is a dc script
k=
while [ "$k" != '********' ] ; do
echo $RANDOM '[48+aPq]sa[55+aPq]sb62%d10>ad36>b61+aP' | dc
k=*$k
done
So that gives "Moon Is a Harsh Mistressin a Strange Land", right? :-)
(Either you are a geek or you are not)
(Sorry couldn't help being a sed-nazi
x-windows permits this - to have a process request to be the exclusive recipient of all keystrokes (no matter what window is selected). I don't know about os x.
But to my knowledge there are few programs that actually do it. I am aware of three: xterm - when you ctrl-click on the window you can ask for "secure keyboard" which does that. gpg-agent's passphrase request window can also activate that feature.
And xscreensaver, when asking for your password to unlock the screen (other screensavers probably too)
One reason why you don't want to keep your xterm on "secure keyboard" all the time is that your screensaver can't detect keyboard activity anymore (and of course you can't type to other windows)
There is btw an application that lets do precisely that, to proxy TCP over ICMP : ptunnel
Sorry for nitpicking but it is not linear, but polynomial. Like the wikipedia page says it has the order O((log n)^3).
Secondly, saying it is "millions of times faster" does not really make sense. We don't measure the efficiency of an algorithm by the actual time it takes but by its complexity. It is likely that the first few quantum computer prototypes will be quite slow and may take longer than classical computers to factor small numbers (I don't know, like 20 digits). However it has a better complexity so: no matter how slow your quantum computer is, it will be faster than all the classical computers in the world once you feed them big enough numbers
[MS will] have to produce a better web browser for their OS users.
... Yes, and I would also like a poney
Actually the op got it wrong. The contest is open for canada excluding Quebec.
You're right actually that should be seen as a bug of my browser (konqueror) - I checked the box "underline links only when mouse is over".
:-( )
It does force links not to be underlined when not hovered on but should also force links to be underlined when hovered on - I guess I should file that as a bug...
I maintain my complaint about the colours - one indicator of link (different colour/face/whatever) is enough for me - slashdot is the only site I know that only relies on the underline for distinguishing (visited) links from the text so it is the only one I know that causes problems with this setting. (There is no way for konq. to set exceptions for specific sites
Anyway that is not the end of the world I guess
- most websites give me this visual feedback you talk about. But I have no feedback at all on
/.
- Worse is that when a link is in already visited state its colour is black so I can't see at all that there is a link!
if anybody responsible for this reads me please change the #visited colour to something other than blackI guess I should write my own css to override this but I've other things to do
It at least works fine on nc. Of course you have to interpret the javascript yourself but I guess that's ok. ("... I don't even see the codes ...")
A while ago xul-based pages was supposed to be the Next-Big-Thing. What happened to that? Is it being left behind because too few browsers are supporting it?
:-)
How does xul compare to ajax?
(Anyway neither is supported in konqueror so it's not like I care so much
Well, just rtfb (read the f*ing binary!) :-)
What about archiving along with the data the software that's able to read it? (i.e. the source code - looks like C is a format that's going to last for a while)
Downloading from any mirror, official or not is fine as long as you check the archive using md5 or sha1 (or ideally, gpg) from the main site, which provides signatures for every archive.
Though what I don't know is why mozilla doesn't insist more on that (you have to go on the ftp site clicking on "other systems" to find the checksums and signatures : ftp thunderbird)
Yep I had seen that; my comment actually was an attempt at humour, but anyway :-)
Emacs shell mixes up too much command input and output to my taste...
Then most shells (and every program using the readline library) support the Ctrl-R function to search through command history, just like emacs.
For searching through command outputs there are terminal emulators like konsole that provide such functions...
Check man readline you'll be surprised how much of emacs functionality you have in your daily shell!
So much for the paperless office !
Maybe they noticed the screenshots looked bad, they are gone from that page (but you can still see them e.g. through mirrordot)
They will "support" those open formats in a broken way and keep their own proprietary format.
That will discourage users to choose those formats yet fulfill the requirement to support open formats.
Alternatively they will interpret it in subtly different ways that make the saved document only usable in Word. (Think HTML and IE...)
It's amusing how "does it run Linux" for an article about windows would get modded +5 Funny and "does it run Windows" for an article about linux get modded -1 Troll :-)
I don't agree. What if you need to print a file on a printer that's on another workstation? What if you need to send a file to someone else? (E-mail? eek.)
Like everybody has already said, solutions to wireless security problems already exist. As for worm propagation, as long as one box can connect to the internet none of this is going to block it.