Yes I have. (I'm an avid Emacs user too) You're right, the command line in Acad is great, but it's the combination of the command line (and its scriptability using AutoLisp) with the UI that makes it truly useful (e.g., as you say, the fact that each time a point is required, it may be entered numerically as well as interactively using e.g. snapping). Acad was written by judicious and wise people. If it had been written by pure click'n'drool advocates, it would only have a GUI. If it had been written by die-hard "GUIs are for losers" Unix freaks, it would only have a command line.
A better non-GUI image manipulation example: pictures that are diagrams, plots, graphical statistics and things like that. Here, non-GUI interfaces are often superior (pic, grap, gnuplot, graphviz...). You create a text file which describes the image.
Even there you could use a GUI for choosing graphical parameters. Have you ever twiddled with Gnuplot's numerous parameters like font size, axis labelling or, let alone, 3D viewpoint selection? In most cases, only the raw data points are written automatically, the commands that set graphical parameter are more or less discovered by trial and error. If there was a text template file format for holding these parameters (could be a gnuplot script in the simplest case), and a way to read that in from a gnuplot script, and an interactive GUI tool for editing such a parameter file, with instant visual feedback, I think many regular Gnuplot users would use it.
"Command line for experts, GUIs for casual users" is a false dilemma anyway. Which is why people don't generally use command lines to draw images, compose music or construct cars and airplanes on a computer, no matter what their skill level is. Even the most skilled "Engineering graduates" use, among other software, CAD programs (which have GUIs).
I can make some shell script both easier and simpler than just about
any GUI application and tailor it to my own needs so that it most
closely meets my needs (and thus meets my own personal notion of
"intuitive").
I don't think you can easily draw or modify a picture using shell programming (and I'm talking about interactive, creative image manipulation here, not about things like "increase the brightness by 50 percent in these 5,000 images").
I challenge you to find any user who thinks that a GUI that can only be operated with a mouse is more usable than one that can be operated using both mouse and keyboard. I also challenge you to find any user who thinks that a GUI with arbitrary tab order in dialog boxes is better than one with visually predictable tab order (except users who've already gotten used to the arbitrary order -- they would've gotten used to the visually predictable one just as well, but the latter is more convenient to new users without being less convenient to experiences users).
You can burn chemical toxins like arsenic, cyanide, or nerve agents because their toxicity stems from their electron shell configurations, which can be influenced by chemical reactions like burning (when in doubt, just expose the stuff to temperatures above 5000 K or something to crack all molecule bounds).
You can't burn nuclear waste this way because radioactivity originates in the atomic nuclei, which won't be changed by anything except natural decay, direct neutron bombardment, or temperatures above 100,000,000 K.
What he's saying is that ultimately, all of your experimental error has to be accounted for by your model. It would be nice to define 1kg as X atoms of X material, but as of the present, we have no way of measuring X atoms to any precision of any material.
Wouldn't it be possible to derive, using the known structure of a C atom, a mathematical expression for the mass of a C(12) atom, and if so, what irreducible constants would be present in that expression?
The theoretical model would include physical things -- namely, silicon atoms. Just like the theoretical model for the definition of the second includes the speed of light. If silicon atoms are too difficult to handle theoretically, why not use, say, electrons, as in 1kg=weight of 1.1xxxe30 electrons (at rest)?
That is what they are doing. They are defining the kilogram as X silocon atoms.
And why do they have to actually create a silicon sphere for that? Couldn't they just define some reasonable X and then derive the actual weight of the kilogram from theoretical models?
I admit I didn't understand your derivation either:-P. Which is why I tried my own (Stefan-Boltzmann law for blackbody radiation) and then saw that your result matches mine for a spherical shield (which is the commonly known special case because it's also used for estimating the surface temperature of planets and such).
Thanks for the link, that shape makes much more sense for the shield.
That's only true if the cross-section of the heat shield when seen from the sun is exactly half the surface area of the shield. I meant a quarter, not half.
That's only true if the cross-section of the heat shield when seen from the sun is exactly half the surface area of the shield. The larger the surface area gets relative to the cross-section, the lower the equilibrium temperature will be because more heat can be radiated away. In the general case it should be
Which makes you wonder why they're apparently designing the heat shield as a flat surface instead of, say, a hollow half-ellipsoid that bulges out in the front.
For the last couple of months I couldn't install updates for my FF add-ons, neither on FF2 nor 3. The download would always hang indefinitely. I never cared enough to investigate this -- until today. It turns out that releases.mozilla.org (the server where the updates are hosted) has an IPv6 address (2001:4f8:0:2::1f), and since my box has one too, FF tries to download the updates via IPv6. Unfortunately, the webserver at 2001:4f8:0:2::1f, when asked to get the update's.xpi file, only sends the header and then hangs indefinitely without closing the connection.
If you ask me, this is inexcusable. Shouldn't many more people have this problem? Doesn't Vista by default try very aggressively to set up a v6 connection automatically?
From the same script:
Note that the blacklist by dowkd may be incomplete; it is only intended as a quick check. With a statement as vague as that, there could be several orders of magnitude more potential keys. I have an affected system here, and when I use its ssh-keygen to generate a few hundred keys, the script reports them all as "weak"[1], i.e. they are all in that set of 262,000. Looks like the script is at least quite good at what it does, and/or if there are more potential keys, they are rarely generated? When I do the same on a Fedora box here, none of them are reported, as expected.
260,000 would be bad though. At one test per second, that's just over 3 days. Of course, if you blacklist hosts after a certain number of failed authorization attempts, you can greatly increase the difficulty of exhausting the keyspace for a potential cracker.
...unless the attacker can obtain the public key directly, which he should be able to do frequently (it's called "public key" for a reason). For example, you can query a host for its public host (SSH) key without a problem. So, unless I'm missing something, you could just obtain that key and match it locally against those 262,000 keys (takes a minute at most, if you have all those keys) in order to find out the private key.
[1]
$ for i in `seq 1 500`; do ssh-keygen -N '' -t rsa -f key$i; done
$./dowkd.pl file key*.pub | grep 'weak key' | wc -l
500
$
If I read the published "weak key detector" script correctly, Debian OpenSSHs will always generate one out of a fixed set of 262148 possible keypairs. Do the math yourself. If you know those keys, this is a 5-minute brute force attack.
...it looks like the affected Debian OpenSSHs can generate only 262148 (or something) distinct keypairs. Can this be true? If it is, this is fucking serious.
I mean, look at this. Are they purposefully trying to waste as much screen real estate as possible? It looks like they deliberately put 50 pixels of even more no-quite-brushed-metal-looking empty space around each little button there.
It might get really nasty if some less-than-stellar programmer who writes such a "function" introduces "creative" means like global variables to pass information from the loop to the function and back; so what was previously a local variable that was visible only to the loop body is now a global variable that, in addition to confusing the reader, may encourage other happy programmers to set them to funny values and wreak all kinds of havoc.
Slashdot Mirror
Have you actually used AutoCAD, say?
Yes I have. (I'm an avid Emacs user too) You're right, the command line in Acad is great, but it's the combination of the command line (and its scriptability using AutoLisp) with the UI that makes it truly useful (e.g., as you say, the fact that each time a point is required, it may be entered numerically as well as interactively using e.g. snapping). Acad was written by judicious and wise people. If it had been written by pure click'n'drool advocates, it would only have a GUI. If it had been written by die-hard "GUIs are for losers" Unix freaks, it would only have a command line.
A better non-GUI image manipulation example: pictures that are diagrams, plots, graphical statistics and things like that. Here, non-GUI interfaces are often superior (pic, grap, gnuplot, graphviz ...). You create a text file which describes the image.
Even there you could use a GUI for choosing graphical parameters. Have you ever twiddled with Gnuplot's numerous parameters like font size, axis labelling or, let alone, 3D viewpoint selection? In most cases, only the raw data points are written automatically, the commands that set graphical parameter are more or less discovered by trial and error. If there was a text template file format for holding these parameters (could be a gnuplot script in the simplest case), and a way to read that in from a gnuplot script, and an interactive GUI tool for editing such a parameter file, with instant visual feedback, I think many regular Gnuplot users would use it.
"Command line for experts, GUIs for casual users" is a false dilemma anyway. Which is why people don't generally use command lines to draw images, compose music or construct cars and airplanes on a computer, no matter what their skill level is. Even the most skilled "Engineering graduates" use, among other software, CAD programs (which have GUIs).
I can make some shell script both easier and simpler than just about any GUI application and tailor it to my own needs so that it most closely meets my needs (and thus meets my own personal notion of "intuitive").
I don't think you can easily draw or modify a picture using shell programming (and I'm talking about interactive, creative image manipulation here, not about things like "increase the brightness by 50 percent in these 5,000 images").
(1) "Usability" is in the mind of the user.
I challenge you to find any user who thinks that a GUI that can only be operated with a mouse is more usable than one that can be operated using both mouse and keyboard. I also challenge you to find any user who thinks that a GUI with arbitrary tab order in dialog boxes is better than one with visually predictable tab order (except users who've already gotten used to the arbitrary order -- they would've gotten used to the visually predictable one just as well, but the latter is more convenient to new users without being less convenient to experiences users).
You can't burn nuclear waste this way because radioactivity originates in the atomic nuclei, which won't be changed by anything except natural decay, direct neutron bombardment, or temperatures above 100,000,000 K.
Google is the (traditional) Microsoft of the web
It's not. The lock-in effect is missing, plain and simple.
What he's saying is that ultimately, all of your experimental error has to be accounted for by your model. It would be nice to define 1kg as X atoms of X material, but as of the present, we have no way of measuring X atoms to any precision of any material.
Wouldn't it be possible to derive, using the known structure of a C atom, a mathematical expression for the mass of a C(12) atom, and if so, what irreducible constants would be present in that expression?
They could measure a smaller number of electrons (maybe just one?) and then multiply, or not?
The theoretical model would include physical things -- namely, silicon atoms. Just like the theoretical model for the definition of the second includes the speed of light. If silicon atoms are too difficult to handle theoretically, why not use, say, electrons, as in 1kg=weight of 1.1xxxe30 electrons (at rest)?
That is what they are doing. They are defining the kilogram as X silocon atoms.
And why do they have to actually create a silicon sphere for that? Couldn't they just define some reasonable X and then derive the actual weight of the kilogram from theoretical models?
I'm on Debian, and my Flash 9 was too old. Updating flashplugin-nonfree remedied this.
All I get is a "to watch this video, you need Flash 9" message -- displayed in a flash object that runs in Flash 9.
Thanks for the link, that shape makes much more sense for the shield.
T_heatshield = T_sun*sqrt(1/9)*(cross_section/surface_area)^(1/4)
Which makes you wonder why they're apparently designing the heat shield as a flat surface instead of, say, a hollow half-ellipsoid that bulges out in the front.
If you ask me, this is inexcusable. Shouldn't many more people have this problem? Doesn't Vista by default try very aggressively to set up a v6 connection automatically?
[1] ./dowkd.pl file key*.pub | grep 'weak key' | wc -l
$ for i in `seq 1 500`; do ssh-keygen -N '' -t rsa -f key$i; done
$
500
$
If I read the published "weak key detector" script correctly, Debian OpenSSHs will always generate one out of a fixed set of 262148 possible keypairs. Do the math yourself. If you know those keys, this is a 5-minute brute force attack.
(you're hearing my head repeatedly hitting the tabletop)
I mean, look at this. Are they purposefully trying to waste as much screen real estate as possible? It looks like they deliberately put 50 pixels of even more no-quite-brushed-metal-looking empty space around each little button there.
Did they *calculate* the half-life or did they *measure* it?
#define Begin {
...
#define End }
#define While
#define For
It might get really nasty if some less-than-stellar programmer who writes such a "function" introduces "creative" means like global variables to pass information from the loop to the function and back; so what was previously a local variable that was visible only to the loop body is now a global variable that, in addition to confusing the reader, may encourage other happy programmers to set them to funny values and wreak all kinds of havoc.