POTUS' power over television networks

Question: Does the President of the United States have the power to cancel a television show he deems critical of him?
Comment: @notstoreboughtdirt The FCC can't cancel shows: https://www.fcc.gov/consumers/guides/cancellation-rescheduling-or-refusal-radio-and-tv-programs
Comment: @motoDrizzt - Please see the [Guidelines for Reviewing](https://meta.stackexchange.com/questions/155538/what-are-the-guidelines-for-reviewing). A question should be closed as a duplicate when the linked answer(s) resolve the question. Despite the name, it isn't really about whether the questions are identical.
Comment: I'm not sure it's precisely a duplicate question. Although the answer is still no because of the first Amendment.
Comment: "How independent is the FCC really?" seems legitimate. Perhaps an edit can take this in that direction to differentiate it from the constitution and fairness based answers in the other one.
Comment: @indigochild: yeah, my mistake, in other site where I spend more time it's the opposite. Sorry!
Answer: No.
It'd pretty much be in direct opposition to the concept of free speech in this country which specifically allows for public criticism of the government without retaliation.
From Wikipedia:

Freedom of speech is the right to articulate one's opinions and ideas without fear of government retaliation or censorship, or societal sanction

user4012's answer does point out ways that a show could potentially be cancelled indirectly but if a president were to demand it directly, then no, they would likely be unable to do so.
Answer: That depends entirely on context. There are some narrow circumstances where the answer is "yes", but in vast majority of situations, thanks to 1st Amendment proections, the answer would be "no"

Is the TV show produced by the executive branch of the federal government?
If so, likely yes (extremely unlikely situation - to the best of my knowledge the government doesn't produce any TV shows in current pratice).
Is the TV show in violation of actual laws?
If so, he can get federal law enforcement to take actions which would cause the show to get canceled (via judicial decree, if found in violation; or simply by the producers wishing to avoid such outcome). To succeed, he would depend on said judicial decree to be positive, which is out of his hands.
Is the show in violation of FCC rules AND on a broadcast network?
If so, he can get the show fined. Presumably, he can change the makeup of FCC and have the friendly FCC make the fine too big, so the show's broadcast network would choose to cancel it.
Note that this isn't a comprehensive solution or a likely one:

FCC fines only pertain to broadcast networks. All the show needs to do is to move to cable and off broadcast, if it was on broadcast in the first place.
Or, the show/network can raise enough money from people opposing such a move (or the President) to cover the fine.
Or, Congress gets upset at this and passes the law limiting how much FCC fines can be or some other limitation to prevent this.

Does he have a big enough political influence with the right audience that he can use the bully pulpit to convince the show financers (advertisers, or companies financing it on cable) to pull the backing from the show?
If so, purely theoretically he can cause the show to be canceled without directly acting on the show itself, merely by convincing other people.
(I'm a bit leery about legality of this, but that's a question of law.se).
That's it. There's no other circumstances or methods that would allow the President to have a show canceled.

Additionally, I'm pretty sure that, if the President goes far enough to do this; they run a high chance of impeachment on 1st Amendment grounds. The support for freedom of speech - as a theoretical concept - has pretty broad bipartisan support, even if in practice both sides are quite happy to do things that are in clear violation of the 1st Amendment spirit ("Fairness doctrine", for example).

POTUS' power over television networks


Can I charge fees for teaching songs I do not own?

Question: I want to teach songs (the songs are around 1 - 25 years old) I do not own to private students online. My concern is that if I charge a fee for these classes, would it fall into an illegal activity?
Answer: You can charge fees for such a service, unless there is a local business regulation preventing it. Depending on your location, it might be required that you receive a government license to engage in any business, so you would need such a license. I've never heard of music teaching being a regulated business, but it might happen. The more important question is whether you can perform the service, with or without fees.
Songs of that vintage are protected by copyright, meaning that you need the permission of the rights holder to make any copy of the work, or to perform it publicly. You might legally borrow a book of songs from a library and perform them for yourself or your family, which is legal. If you have an online student and they likewise borrow a copy of such a song book from the library, then the two of you would have legal copies of the songs, without owning them. It is not legal for you to just copy the book and send it to the student. It might be found legal for you to do limited copying, under the fair use doctrine, but then it would matter substantially whether you charge for this instruction (for-profit use disfavors "fair use").
One of the essential rights of the copyright holder is the exclusive right to authorize

in the case of literary, musical, dramatic, and choreographic works,
  pantomimes, and motion pictures and other audiovisual works, to
  perform the copyrighted work publicly

Perform means perform, i.e. singing the song, and to perform or display a work "publicly" means—

(1) to perform or display it at a place open to the public or at any
  place where a substantial number of persons outside of a normal circle
  of a family and its social acquaintances is gathered; or
(2) to transmit or otherwise communicate a performance or display of
  the work to a place specified by clause (1) or to the public, by means
  of any device or process, whether the members of the public capable of
  receiving the performance or display receive it in the same place or
  in separate places and at the same time or at different times.

The question is whether a one-on-one private instruction session (e.g. via Skype) is a public performance.
An internet instruction session is not a situation where "a normal circle of a family and its social acquaintances is gathered", so yo are not excused by that part of the law. The internet is "open to the public" in the same way that a concert is open to the public – you may have to pay to get in, but it is open to the public. However, in a 1-on-1 Skype session, there may not be a substantial number of persons gathered: the law does not say what a substantial number is. The second clause accommodates internet applications, and says basically that "substantial" can be cumulative, thus if you have 10 students, that probably is "substantial", but if you only have 1 student, that might not be substantial.
There are explicit legal permissions for instructors to perform in certain educational circumstances, whereby an instructor can have a class with a number of students. The rules for that permission are not simple. It allows performance

by instructors or pupils in the course of face-to-face teaching
  activities of a nonprofit educational institution

which this is not. The remaining paragraphs, especially 2 and 4, are very complicated (that's code for "nearly incomprehensible"), but do not seem to provide an exception for for-profit instructional performances: I would say that you really need to hire an attorney with expertise in music performance licensing law to get a definitive assessment. It is more likely than not that such a scheme, without a properly licensed copy of the songs, violates copyright law.


SD card suddenly damaged

Question: I'm using Xperia C. My SD card works perfectly fine but after I power down my phone and turn it back on, suddenly it says that my SD is damaged and I have to format it. I can't even mount it on my phone cuz when I do, it just unmount it again. This is not the first time it happen. Last time, it was with my first SD card and now, my second. What should I do?
Comment: Both were 8GB Sandisk sd card. So now, i changed to Toshiba 8GB. It works fine now but let see how it goes. Thanks.
Comment: Are both cards (old and new) from the same brand, and maybe even the same size? There are incompatibilities reported here and there, so you might want to try a different brand. You could check with some Xperia specialized forums to see what combinations others used successfully, and if maybe somebody else experienced the same trouble with your combination.
Comment: So my guess was right at this point (so far). Don't forget to report back when you think you can tell the difference; might prove helpful to other Xperia C users :)
Answer: I just had this problem less than an hour ago on my Acer Iconia a500. I've had it happen with multiple SD cards on different devices. This is how I overcome this problem everytime. The only way that this wont work is if the card is fried
To the problem of your "damaged SD card", what's most likely going is corruption of the file system. Something on the phone made an invalid entry.

Plug your SD card in the reader
Run Mini Tool Partition Wizard (MTPW)
Select Partition Wizard, other is Data Recovery
Pick the SD card in the list
Right click for drop down menu
Scroll down and click on Check File System
Let it finish, then exit MTPW
Unplug and re-plug SD card into reader
When "Do you want to scan and fix" pops up, check both
When finished, unplug from reader
Mount in your phone and enjoy.

I know it's a late answer,  but knowledge is power.

SD card suddenly damaged


lighttpd url rewrite to subdomain

Question: How does the lighttpd rewrite work for folowing?
http://example.com/file_46634643.jpg to http://sub.domain.com/46634643.jpg
If it's possible...
Answer: Yes, it is possible. Use mod_rewrite, here is an example:
url.rewrite-once = ("^/file_([0-9]+\.jpg)$" => "/$1")

Check Lighttpd's mod_rewrite documentation for more details.
Answer: I don't think mod_rewrite allows you to "rewrite" to another (sub)domain. You could use mod_redirect (but it's a redirect, not a rewrite). Here is a slightly modified version of Bartosz's answer:
$HTTP["host"] == "example.com" {
  url.redirect = ( "^/file_([0-9]+\.jpg)$" => "http://sub.domain.com/$1" )
}

Check http://redmine.lighttpd.net/wiki/lighttpd/Docs:ModRedirect

lighttpd url rewrite to subdomain


What's the difference between 'just' and 'fair'?

Question: What's the difference between 'just' and 'fair'? OED gives slightly different definitions, but they are not distinct enough as to be clear (to me). Is the difference simply idiomatic, or is there a semantic difference that I am not aware of?
Comment: *just* and *fair* each have other non-overlapping meanings.  When the intended meaning is the same, either may be used.
Comment: Start by reading philosopher [John Rawls](http://plato.stanford.edu/entries/rawls/), a "liberal egalitarian" who espoused "Justice as fairness". I was reading about his ideas just last night in Michael Sandel's _Justice: What's the Right Thing to Do?_ Made me sick to my stomach. I don't think they overlap often enough to honestly be considered interchangeable: What is fair is not always just, and what is just is not always fair. Both ideas must be considered & evaluated. **Fair** = both sides are equal; **Just** = the morally good side wins. Too Disneyesque for me. "Life is not fair" (JFK)
Comment: Perhaps this question is worth cross-posting here?

http://philosophy.stackexchange.com/
Answer: Because there's a lot of overlap between the two words, in many contexts they're interchangeable. But in some specific idiomatic forms (i.e. - "It's a fair cop", "We fight a just war") only one is used.
To the extent that there's a semantic difference, I would say that a fair settlement, for example, is one where the parties directly involved feel a satisfactory compromise has been reached. But to me at least, a just settlement is one that meets external criteria of correctitude (opinions of outsiders, formal moral/legal codes, etc.).
Comment: This is a great answer. Others say similar things, but this summarises the gist of the difference into a couple of simple and clear phrases. Thanks!
Comment: @CesarGon: It's worth noting that more people have written [**fairness** is in the eye of the beholder](https://www.google.co.uk/search?q=%22fairness+is+in+the+eye+of+the+beholder%22&btnG=Search+Books&tbm=bks&tbo=1) than have used the same cliche with [justice](https://www.google.co.uk/search?q=%22justice+is+in+the+eye+of+the+beholder%22&btnG=Search+Books&tbm=bks&tbo=1). I know that's partly because *fair* can also mean *beautiful*, so it's a better wordplay, but I think there's more truth in it too.
Answer: As a teenager, I attended an "Institute in Basic Youth Conflicts" seminar, where — among other things — I read a pamphlet entitled "Fairness: the Unexpected Enemy of Justice".  The upshot was that justice comes from God, but fairness is a human construct.  I thought that was a bunch of hooey then, and I still do — but the concept has some merit.
A useful distinction is that justice is objective, while fairness is subjective.  A judge's sentence may be just, because it is based on a law that is the same for all, and yet not seem fair because it fails to take circumstances into account.
Even this is a bit slippery, because standards of justice vary widely throughout and between societies — e.g. cutting off a thief's hand would be considered justice in Saudi Arabia but a heinous crime in the United States — but I think it generally holds true.
Comment: The principle of this is fine, but I think you have transposed *fairness* and *justice*. Human courts can provide a fair trial (e.g. giving both sides the same chance to persuade the jury and applying the same law to everybody), but can never provide absolute (divine/abstract) justice; nobody is more aware of that than the judges themselves.
Comment: @TimLymington - Not transposed so much as expressed myself clumsily - you and I are making the same point, that *justice* is absolute but what humans are capable of, at their best, is *fairness*.  I still utterly reject the IBYC concept that the two are in opposition.
Answer: I agree with Jim's comment; however, The American Heritage Dictionary, 4th edition, had this interesting note under the entry for fair:

Synonyms fair, just, equitable, impartial, unprejudiced, unbiased, objective, dispassionate These adjectives mean free from favoritism, self-interest, or preference in judgment. Fair is the most general: a fair referee; a fair deal. Just stresses conformity with what is legally or ethically right or proper: "a just and lasting peace" (Abraham Lincoln)...
Answer: "Just" refers to an action justified under the circumstances. "Fair" refers to an action that treats people as they deserve to be treated. Many times, actions that are just are not fair. In hard cases, an action may be justified because there aren't superior options, even if it's results are unfair to at least some people.
If a madman holding a single hostage is going to blow up a school full of children, shooting him through the hostage may be just, but it isn't fair to the hostage.
In addition, outcomes that aren't the results of human action are neither just nor unjust. For example, a hurricane is neither just nor unjust. Yet a hurricane can be very unfair. One lazy person wins the lottery, another more deserving person does not. There's nothing unjust about that, but it's not fair.
Answer: I agree with the distinction drawn by author Holly Lisle in this essay, where (to summarize) she states:

Justice holds that all men are equal in the eyes of the law.
Fairness states not that all men are equal under the eyes of the law.
  . . but that all men are equal.
And all men aren't.
Justice is the desire of the honest individual, who takes action with
  integrity and accepts the consequences as his earned due.
Fairness is the desire of the unthinking herd, that envies what it has
  not earned and demands a piece of it just because it's breathing.

Read the entire piece to get the full flavor of the distinction between justice and fairness that Lisle is making.
I should point out that the Pledge of Allegiance of the U.S.A. desires "liberty and justice for all," not "liberty and fairness for all."
Comment: I believe that the above is a skewed notion of fairness. A fair coin is one with no intrinsic bias. What 'the unthinking herd' may perceive / desire / claim as fairness may well be far from true fairness. But I wonder who gets to distinguish between 'the honest individual' and 'the unthinking herd'. Some may wonder whether it is fair that some are born with no apparent need to do any earning. I'll just add that I'm disagreeing with Lisle's terminology, not her sentiments. See Wiley C's reply in that thread.
Answer: "fair" is just a normal judgement balancing both sides, considering all the pros and cons
"just" is done without any bias to any one
"fair" is being equal to both
"just" (adj) means giving correct judgement

Ex: the king was "fair" to both the minister and the subject. Jahangir
  was a "just" ruler
Answer: A fair dad makes sure that each of his kids gets the same number of scoops of ice cream. A  just dad makes sure that each of his kids gets the ice cream that s/he needs. A fair ref makes sure that all players that commit fouls (that the ref sees) get penalized equally for similar violations. A just ref limits his penalty calls reasonably so as to not slow down the progress of the game. A fair man distributes equally among everyone and does not take individual cases or needs into consideration. A just man considers carefully the ultimate good of all those who are affected by his decision.


Measuring ADC sample rate - Arduino DUE

Question: I want to measure the conversion rate of an arduino DUE. I know I could just take it from the datasheet but I need to measure it because I am running the ADC in free running mode. Hints are welcome, I really don't know where to start.
Comment: What do you mean by "conversion rate"? Time to perform an acquisition? The easiest way is to save the millis value, perform 1000 acquisitions, then save again the millis value and make a subtraction. If the value is small, increase the number of acquisitions to have a reasonable time (1-10 s). Then make the division. For instance, 10000 acquisitions -> 7.92s means that each acquisition is 0.792ms, so 1262 samples/s
Comment: ... Or make it toggle a pin each time the acquisition is done, then measure with an oscilloscope... Or tell us what you want to achieve, so hints can arrive...
Comment: Hi! Thanks for your answer! What I need is to measure the sample rate of the ADC because I need to do an Antialiasing Filter.
My expectative is to achieve a sample rate of 400kHz. If this value is fixed, it would be a lot more easy to do the processing that I want to do (FFT, Correlation)
Comment: If you plan on doing a real analysis on it a freerunning adc is not the way to go... You need precise timings for this. If you want to know what is the maximum speed you can achieve, go with the pin toggle or the multiple adc conversions techniques, but even if you manage to achieve a 400kHz sample rate then you have to actually process each sample and present results in less than 2.5 us...
Comment: No answer, but I'd be interested in this as well.
Answer: Measure how many times per second was main loop called:
<code>bool secondPassed()
{
  static long lastTick = 0;
  long now = millis();

  if (now <= lastTick + 1000)
    return false;

  lastTick = now;
  return true;
}

int counter = 0;
void loop()
{
  analogRead(A0);
  counter++;
  if (secondPassed())
  {
    Serial.println(counter);
    counter = 0;
  }
}
</code>

Measuring ADC sample rate - Arduino DUE


Meshmixer size of model

Question: I've created a model in Sketchup and exported the file as a .stl
Since the model is 80cm x 24 cm i need to cut it in meshmixer. But when i open it in meshmixer it appears tiny. Why doesn't it open as the real size?
Comment: it might automagically scale to the size of the chosen printbed, or it might be that the model actually is such tiny. It would help to have access to the model.
Comment: Perhaps you modeled it in cm, but most programs import in mm. The stl file does not include a scale, just a number of units.
Answer: You mention your dimensions in cm. Any chance that the STL export is also in cm where Meshmixer might expect mm?
Assuming your Sketchup template was set to cm:
To validate this guess you could measure/eyeball a known dimension and if that comes out to be 10 times too small you could scale your model by 10 times.
Alternatively you could adjust the template in Sketchup.
Additional information on STL files:
By it's very nature, the STL file format is just a bunch of unitless numbers in a well defined structure. This structure represents a set of points (vertices), lines (edges) and and triangular surfaces (facet). A few simple rules apply to exactly how all this should be defined. (See here)
But the key thing here is that an STL file is not aware of units, the program used to generate the STL file (e.g. CAD software) needs to be told what units to use, and accordingly the reading program (e.g. slicer) needs to use the same settings. Generally in mechanics applications we default to mm, at least in metric land. All this is explained a bit more verbose here.
Comment: Can you split the model in subparts and import those into Cura? From there Cura should put the pieces in the center and on the buildplate.
Comment: Genius!! It worked perfect when changing to milimeters. But now the model appears outside and far away from box printer box (yes i am new to this)
Comment: Any chance you made your drawing offset  from the world zero? As in: where did you draw you part in Sketchup, at the origin or just somewhere else?
(Although you can change that in Meshmixer as well by using the align tool.)
Comment: The align worked. But the printerbed is not centered to the screen. It uses the center of the model (original zero)  so it becomes weird when I rotate the model
Comment: At this point I am a bit unclear on the specifics. What exacty do you need to accomplish in which software? I understand you design with Sketchup, and want to cut it up in Meshmixer. What slicer are you using. (Some slicer allow you to do the cutting part in the slicer as well.)
Comment: Sorry. I use Cura for the printer, it's a Ultimaker S5

Meshmixer size of model


use of gnome-keyring-daemon without X

Question: I'm wondering if it is possible to use gnome-keyring-daemon without X.  Normally it will present a graphical prompt in order to acquire a password for the keyring; is there a way around this?  I'd like to be able to use ubuntu one without having to start a graphical session and type in my password.
Answer: You can use pam_gnome_keyring.so to start and unlock the daemon. GDM already does this; for login, you must configure it manually.
Add these lines to /etc/pam.d/login:

auth     optional  pam_gnome_keyring.so
session  optional  pam_gnome_keyring.so auto_start

If you log in without a password (SSH with Kerberos or public keys), this may work: (I haven't tested it)
echo -n "mypassword" | gnome-keyring-daemon --login
(You still need the daemon to be running - either started via PAM or with --daemonize.)
Comment: @intuited: Well, then do something like this: `read -rsp "Password: " pass; echo -n "$pass" | gnome-keyring-daemon --login` in a script.
Comment: err.. nevermind, it's documented by `gnome-keyring-daemon --help`.  I just checked the manpage and /usr/share/doc.
Comment: Actually yeah, that would work; I was forgetting that echo was a builtin.
Comment: In reply to old comment from @intuited: `gnome-keyring-daemon --help` gives me a good overview, but `man gnome-keyring-daemon` just contains a short description on the program itself but to no arguments.
Comment: Second case is the case in my case.   That (undocumented?) `--login` option is pretty useful, though I sure wouldn't want to keep my unhashed password in a script or put it on a command line.  reading in unechoed mode from within a (non-shell-language) script that then passes that input to the spawned daemon would probably be a good way to do this.  I should only have to start this process once per boot, so it makes sense to type in the password; I just need to be able to do it at the command line instead of via the GTK dialog.
Comment: I added the lines to the pam.d/login file. But I still have the same error. I also started the gnome-keyring-daemon. But how doe I start it via PAM?
Answer: Synopsis
The requisite jobs of installing svn with keyring support and installing the
Collabnet keyring_tool application are already performed for our Linux servers.
1) Configure SVN client to use keyring:
1.1) Edit ~/.subversion/config
[auth]
password-stores = gnome-keyring

1.2) Edit ~/.subversion/servers
[global]
store-passwords = yes
store-plaintext-passwords = no

2) Create a keyring for your password. You will be prompted to create a new password to unlock the keyring; this may be anything you wish:
keyring_tool --create=svn

3) Set the new keyring as the default:
keyring_tool --setdef=svn

4) In .bash_profile or .bash_login (assuming you are using bash as your terminal)
    if [ -e /usr/bin/gnome-keyring-daemon ]; then
      if [ ! -z "`kill -0 $GNOME_KEYRING_PID 2>&1`" ]; then
        # Create dbus transport link for SVN to talk to the keyring.
        eval `dbus-launch --sh-syntax`

        # Start the keyring daemon.
        # The use of export here captures the GNOME_KEYRING_PID, GNOME_KEYRING_SOCK
        # env values echoed out at startup.
        export `/usr/bin/gnome-keyring-daemon`
      fi
    fi

5) In .bash_logout
    # Kill the message bus established for SVN / Keyring communication
    if [ ! -z "`kill -0 $DBUS_SESSION_BUS_PID 2>&1`" ]; then
      kill $DBUS_SESSION_BUS_PID > /dev/null 2>&1
    fi

    # Kill the Gnome Keyring Daemon prior to logout.
    if [ ! -z "`kill -0 $GNOME_KEYRING_PID 2>&1`" ]; then
      kill $GNOME_KEYRING_PID > /dev/null 2>&1
    fi

Background
I ran into a similar problem while trying to establish a hassle free way to ensure authorized user access to certain SVN repos at work.  Basically we had to force credential checking every time a user accesses the server so even the svn update command would require authentication.  Clearly plain text password storage was out so with a little research I came upon using the gnome-keyring as a way around harassing our user base with constant authentication requests while still keeping unauthorized users out of repositories they should not have access to view.
Much of our day to day work is done via ssh tunnels into a RedHat server w/o X support so I had to find a way around the X11 support.  After some searching I managed to find the way around it here:
Source Material
http://support.wandisco.com/index.php?/Knowledgebase/Article/View/362/17/how-to-setup-encrypted-svn-password-storage-using-gnome-keyring-in-an-ssh-session
They key here is using the Collabnet keyring_tool to create a keyring without the gnome-keyring-manager client and establishing the dbus-launch yourself rather than letting SVN handle the setup.  SVN uses DBUS to connect to the gnome-keyring-daemon and affect the overall authentication.  By manually starting and tearing down the dbus session with -sh-syntax you avoid trying to connect to an X client on dbus startup.  If you just start the gnome-keyring-daemon and attempt to use SVN it will still prompt you for your keyring password but then will prompt you for your SVN credentials as well.  The dbus will fail when SVN tries to start it because of the lack of an X client; apparently SVN does not use any special flags when starting the dbus.
Comment: Thank you so much for this, have been pulling my hair out trying to get rid of a "CRITICAL **: Error communicating with gnome-keyring-daemon" error on git pull. Your changes to ~/.profile and ~/.bash_logout fixed that... Still not saving passwords but I'm one step closer! (Ubuntu 16.04.1 LTS)
Answer: I had some success with getting mysql-workbench to work with gnome-keyring in an x-forwarded SSH session. This was an account that used publickey authentication (no password).
I used dbus-run-session to achieve this once connected to the ssh session:
dbus-run-session bash -c 'GNOME_KEYRING_CONTROL=1 mysql-workbench --verbose'

hopefully this information is useful to someone!
Comment: This helped one step closer to having mysql-workbench run inside a docker container and export the display to my mac host. When I try to add a password to a new connection, it shows me the prompt, but after typing the pwd, I get: "Failed to execute program org.freedesktop.secrets: Operation not permitted". Any clues?
Answer: First, what you really want to be doing is running Ubuntu One strictly from command-line.  Take a look through the Ubuntu One FAQ.  The FAQ says it's not presently possible, but there are some CLI tools like u1sdtool and u1sync.  There's also a set of FAQs on Ubuntu One at Launchpad; the content may be the same as the earlier wiki.ubuntu.com link.
Regarding your actual question about gnome-keyring-daemon, the FAQ suggests (1) setting auto-login and (2) synchronizing your keyring password with your login password.  This would (in theory) avoid the password prompt, but it would require at least a basic X-session to be running.
There's an Ubuntu One bug/wishlist on Launchpad that requests making it easier to handle headless systems.  Apparently building from source is recommended for a lightweight install (to avoid the need for all the GUI libraries and such).  This comment is old, but particularly interesting:

The problem is that we use python-gnomekeyring. For us to support headless, we'll have to switch to python-keyring, and handle storing tokens somewhere other than gnome-keyring on headless displays. However, none of this is going to happen for the Karmic packaging as it is frozen, and this change wouldn't be acceptable in an SRU.
For Lucid, we should have a more robust authenticaton service, which should allow us to support headless displays better.

I can't tell if this "more robust authentication service" was actually put in place for Lucid; based on the package dependencies, it seems the Ubuntu One client is still dependent on python-gnomekeyring.

use of gnome-keyring-daemon without X


jQuery Mobile on Android - textbox and numeric keyboard issues

Question: I am developing an app with PhoneGap and jQuery Mobile for iOS and Android. My code works just fine in iOS 5, but I am having a lot of trouble with Android 2.3.*.

First - Android does not support input type="date", as iOS does. Is there a way to use some kind of simple plugin to show a date picker?
This "bug" (or feature) is only present when debugging on a device, not in the emulator. Look at this screenshot of my login page in the app:

When I select the Username textbox the keyboard and a white box shows. The white box contains the text Password. Really strange. The code for the Username text box:
Username:
<input type="text" value="" name="username" id="username" data-form="ui-body-a" />

Is there a way to get rid of that white, ugly textbox and write the text directly into the Username textbox as it should be?
3 This is one of many settings pages in the app, the user should input numbers in a couple of fields. I use input type="tel" to display a numeric keyboard. Works just fine on iOS, and the numeric keyboard shows up in Android as well, but it's impossible to close it (no close button and not possible to close by tapping somewhere else) and hence not possible to leave the page as the footer menu isn't visible. A white box appears in upper left corner, and the header (with back button) disappears:

Html for this:

            Per day:

            <input type="tel" name="ordersdaygoal" id="ordersdaygoal" value="0" mini="true" style="width: 150px;" maxlength="9" />

...

Any suggestions to solve these Android mysteries?
Comment: On question 2: I have identified it to be the iScroll-plugin that are messing up the text input boxes. Still have to find a way to make it work. And yes - the problem is only present on a device, not the emulator...
Answer: I can only help you with your first question, we used this jquery plugin for date, it's highly configurable:
https://github.com/jtsage/jquery-mobile-datebox


Finding the Uncertainty in a Spectral Line

Question: Currently, I am doing a lab in school on atomic spectroscopy. After taking readings of strong emission lines of various elements, I have fit the data using a Voigt Profile function from lmfit. The function minimizes the reduced chi-squared  and returns the best fit along with fitting parameter values (center, amplitude, sigma, gamma). I am mainly interested in the center of the line profile. But, what is the uncertainty in this reported center? Or how would I report the measurement and its uncertainty.
Comment: This is really a question about statistics and not astronomy or even physics.
Comment: I'm voting to close this question as off-topic because it's a statistics question
Comment: @CarlWitthoft we can vote to close a question here if it is *off-topic in this site*, but "because it's an X question" or "is better asked elsewhere" are not good close reason. OP decides where they would like to ask it. However I'm sure that the OP would get an excellent answer in [Cross Validated SE](https://stats.stackexchange.com/) though they might be tougher on the question as written.
Comment: @ahayes24 have you looked at the `out.fit_report()` method shown in your linked documentation?  Search for "+/-" I think that's what you are looking for. However, I am not sure that's the whole story because when strong correlations are present (those are also included in the fit_report) then a poor fit may have worse uncertainties than the +/- might suggest. Now *that's a question for Cross Validated SE!*
Comment: @CarlWitthoft  Apologies for writing this question here. I assumed Astronomy had a lot of experience in spectral line fitting so I thought I would try it here. I can move it to the Cross Validated SE section and make my question clearer.
Answer: If you are doing chi-squared fitting, then a value for the uncertainty (or an estimate) should have been returned by the software. If not, you could perhaps manually estimate by fixing the line centre at various values, allowing the other parameters to be fitted, and seeing where the minimum chi-squared increases by 1 over the global minimum.
Failing that, output your spectrum as an ASCII file and fit it with something that does provide uncertainties like gnuplot.
Failing that, here's a rule of thumb. The line centre is determined with a precision given by the FWHM divided by the signal to noise ratio per pixel.
Note that none of the above take any account of uncertainties in the wavelength calibration.
EDIT: It appears that lmfit does estimate uncertainties. https://lmfit.github.io/lmfit-py/confidence.html
Comment: I would add that the OP should take the time to learn **in detail** what the particular python tool he's using does, how it does it, and why.  I might start by telling him to use *scipy* because it's a more reliable (vetted, reviewed) package than some random GitHub tool.
Comment: I left [this comment](https://astronomy.stackexchange.com/questions/34136/finding-the-uncertainty-in-a-spectral-line#comment65200_34136) in review before seeing your answer. I know that strong correlations are "bad" and can cause problems especially when the quality of the fit is poor, but I don't know how to articulate that accurately.


Is it proper to daven for someone who has "no hope"?

Question: If someone has a sickness that by current medical knowledge is terminal and has no chance of being cured, is it proper to daven for that person to get better? Might this be considered a tefilas shav or davening for a miracle?
Comment: At the very least, you can daven that the person doesn't suffer.  (And, while we don't count on them, Hashem can make miracles.)
Comment: Possible duplicate https://judaism.stackexchange.com/questions/48492/ "Reb Shlomo Zalman said not to pray publicly for people who the doctors have given up hope to have a natural recovery, even for a great Rabbi"
Comment: They would presumably still have a soul, what could be wrong with praying for that?
Comment: @JoshK the soul presumably doesn't need to be cured.
Answer: To quote the Gemara in Berachos 10a:
For background: King Chizkiya was ill. Yeshaya gave him a Nevuah that he would die from this illness, and after telling Chizkiya that there was nothing that could be done at this point, as the decree had already been handed down, Chizkiya had this to say:

בן אמוץ כלה נבואתך וצא כך מקובלני מבית אבי אבא אפי' חרב חדה מונחת על צוארו של אדם אל ימנע עצמו מן הרחמים
Son of Amotz, cease your prophecy and leave! Thus have I accepted from the house of my forefather: even if a sharp sword is placed on a person's neck, he should not withhold himself from mercy.

As the verses in Yeshaya 38 continue, Chizkiya davened that he recover, and indeed he did, gaining for himself another 15 years on the throne.
According to Rashi, the tradition to which Chizkiya refers is the fact that, as described at the very end of Sefer Shmuel, his forefather David saw the malach prepared to smite Yerushalayim but still prayed.
What we see from here is that even if all seems lost, the doors of prayer are never closed. One is always able to pray.
In fact, this is actually codified in Halacha. One who is on his deathbed should say Vidui, whose basic text, as recorded by the Shulchan Aruch (YD 338:2), reads as follows:

מוֹדֶה אֲנִי לְפָנֶיךָ ה' אֱלֹהַי וֵאלֹהֵי אֲבוֹתַי שֶׁרְפוּאָתִי וּמִיתָתִי בְּיָדְךָ, יְהִי רָצוֹן מִלְּפָנֶיךָ שֶׁתְּרַפְּאֵנִי רְפוּאָה שְׁלֵמָה, וְאִם אָמוּת, תְּהֵא מִיתָתִי כַּפָּרָה עַל כָּל חֲטָאִים וַעֲוֹנוֹת וּפְשָׁעִים, שֶׁחָטָאתִי וְשֶׁעָוִיתִי וְשֶׁפָּשַׁעְתִּי לְפָנֶיךָ, וְתֵן חֶלְקִי בְּגַן עֵדֶן, וְזַכֵּנִי לָעוֹלָם הַבָּא הַצָּפוֹן לַצַּדִּיקִים.
I admit to You, Hashem, my G-d and the G-d of my forefathers, that my healing and my death are in Your hands. May it be Your will before You that You heal me with a complete healing, but if I die, may my death be an atonement for all of my sins which I have sinned before You, and give my portion in Gan Eden, and may I merit the World to Come which is hidden in waiting for the righteous.

While a large portion of this prayer describes the imminent death which the one praying will seemingly be subjected to, what it is really saying is that Hashem should spare him and let him live, but that if he should die anyway, at least let it be an atonement for his sins. Like by Chizkiya and David, the one praying should never despair, even if there is a sharp sword on his throat.
Perhaps you may argue that the OP's case is different, though, as it's someone else davening for him, rather than the patient davening for himself. To that I point to an earlier Gemara in Berachos, on 5b:

אין חבוש מתיר עצמו מבית האסורים
A prisoner cannot free himself from prison.

In context, this means that while a sick person cannot pray to be saved from his own ailment, someone else can. Certainly in our case, where a sick person can save himself, someone else can!
Answer: National Medical Halacha Society:
Praying for a Miracle

Rav Hershel Schachter writes regarding the prohibition of asking G-d for a miracle: "The Shaarei Teshuvah quotes the three exceptions
  to the rule as stated by the Acharonim, as to when one is permitted to
  ask for a nes: 1) One may ask for a nes nistar. For this is what
  hashgacha is all about- God controls the world from behind the scenes,
  without openly violating any of the rules of nature. 2)Since we
  believe that, "ein mazal le-yisrael," that the Jewish people are,
  "lemala min hateva," there is nothing at all improper about requesting
  a nes nigleh on their behalf. 3) Even if the nes is not for Klal
  Yisrael, but only on behalf of an unusual tzadik, this too is allowed,
  as is evidenced from the various stories related in the Gemara Taanit
  regarding several tzadikim who prayed for miracles. The great tzadik
  is also "lemala min hateva."
In Parshat Korach we find Moshe Rabbeinu requesting of God that even
  if the opening of Gehenom not be here, that He make a nes and "yivra
  Hashem" - let it move to here. Because the miracle was needed- either
  for klal yisrael or the unusual tzadik- Moshe was allowed to pray for
  it. A similar situation appears in the Haftorah. Shmuel Ha-navi calls
  upon God to bring about a miracle on Shmuel's personal behalf, to
  indicate his righteousness. This appears to be the thematic similarity
  between the sedra and the Haftorah: the exceptions to the rule i.e.
  when one is permitted to pray for a miracle.
To illustrate this point, I remember many years ago, when I visited
  the Ponovez Yeshina in Benai Brak, the tzibbur was reciting tehillim
  on behalf of a cancer patient on whom the doctors had given up hope.
  The Mashgiach, Rav Yecheskel Levenstein - refused to participate in
  the prayers because in effect they were praying for a miracle."
There is much discussion in the medical halacha literature regarding
  the permissibility of praying for the DEATH of a terminally-ill
  patient. However, it appears from Rav Shachter's analysis above that
  the reverse question must also be addressed. Is one allowed to pray
  for the continued LIFE of a terminal patient? The answer, I suspect,
  is not absolute. In many cases praying for the cure of a terminal
  patient may only require a nes nistar, which is permissible.
  Apparently, Rav Levenstein ZT"L felt that an even more open miracle
  would have been required in the case of the cancer patient.
Avi Oppenheimer
Answer: This appears to be addressed by R. Yehuda HaChossid.
Sefer Chassidim # 794

אל יתפלל אדם תפלה שאי אפשר לעשות בקשתו אע"פ שהיכולת ביד הקב"ה אין לבקש
  דבר שאין נעשה (כפי הטבע) כגון אם אשתו הפילה לשמונה חדשים ברור הוא שאין
  הולד של קיימא אין מתפללים עליו שיחיה אסור לבקש דבר שאינו ראוי לומר
  כגון יהי רצון שתלד אשתי לח' חדשים ויחיה הולד ואסור להתפלל שיעשה לו
  הקב"ה נס בשינוי העולם שאם יש לו אילן שיוציא פירות קודם זמנו כמעשה דר'
  יוסי בן אבין וכר' יוסי דמן יוקרת בתענית
A man should not pray a prayer that is impossible to be fulfilled.
  Even though God has the ability to do it, one cannot request something
  that cannot be done (within nature). For example if his wife
  discharged the fetus at eight months it is certain that the fetus is
  not viable [and therefore] we do not pray for it to live. It is
  forbidden to request something that is not fitting to say, such as
  "may it be [God's] will that my wife give birth at eight months and
  the fetus survive". It is forbidden to pray that God perform a miracle
  that deviates from [the natural order of] the world, [such as] if
  he has a tree that it should give forth fruit before its time like the
  incident with R. Yosi Ben Avin and like R. Yosi of Yokeres in
  [Maseches] Ta'anis.
Answer: There's a different angle to this question:
Practically any Mitzvah has two "applications" - חפצא and גברא, first the object on which the M. is performed and the second is the subject that performs the M.
This is learned from B"B 10a:

" שאל טורנוסרופוס הרשע את ר"ע אם אלהיכם אוהב עניים הוא מפני מה אינו מפרנסם א"ל כדי שניצול אנו בהן מדינה של גיהנם"
"And this is the question that Turnus Rufus the wicked asked Rabbi Akiva: If your God loves the poor, for what reason does He not support them Himself? Rabbi Akiva said to him: He commands us to sustain the poor, so that through them and the charity we give them we will be saved from the judgment of Gehenna."

R"A's answer was that [even in such a clear case of giving out] the giver profits from the good deed.
Same with Teffilah - it helps not only the receiver but the person that davens - it develops good qualities, such as devotion, altruism, caring, belief, togetherness etc. So with no relation to the results for the object of the Teffilah, it surely helps the person - and it is worth doing it!

Another angle:
There are two sorts of "good"s - subjective (what we think is good) and objective (what Hashem knows is good). It is more preferable (let me say it mildly) to daven in general terms, like Moses when he said "א-ל נא רפא נא לה", i.g. asking Hashem to have His mercy and do general good to a person, than asking for something specific, that looks good in our eyes, e.g. asking for a person to complete recovery.
As we don't know the G-d's plan for that patient and what is objectively good for him, we better pray in general terms, as I outlined.

Yet another angle:
As medicine is a science, any recovery is subject to statistical deviation - it always falls between 0% and a 100%, and it is never EITHER. So be it 1 in a billion, there's always a chance.
A miracle, in this case, would be something that contradicts the [G-d's] laws of nature, as the Gemmorah in Berochos says "turning a female fetus into male" or for example pumping milk thru his veins instead of blood.
Comment: This addresses prayer in general, but does it address whether there might be a problem with praying for something that "can't happen"?
Comment: It says that in doubt, it's better pray, as it surely helps the healthy person.
Comment: But how do you know that? The question mentions the possibility of a false prayer/praying for a miracle. Are you denying such a category?
Comment: I added that in my answer right now. Yes the last part explains that scientifically.


How do you initialise the current contents of a directory as the state of a git branch?

Question: I have a branch A and want to make a list of quite significant changes to it.  The end result of these changes already exists in directory B, which I would also like to become the new working copy.  In essense, I just want to "Make this directory the latest working copy of my branch."
There are 2 possibilities I am currently aware of to achieve this:

Checkout A into a temporary directory C, delete everything except ".git", copy the contents of directory B into C and then add/commit/push from directory C. Finally, move the entire contents of C back into B.
Clone the repository without checkout into temporary directory C, move the ".git" directory from C into B.  Add/commit/push from within B.

The problems with both of these solutions, besides being horribly clunky, is that they require disk space for both directories B and C.  Option 1 also involves a little more file shuffling.  So currently my best solution to this is option 2, detailed steps given below.
I imagine there's a better way to do this using "reset" or "symbolic-ref".  I have tried various options without success.
mkdir /tmp/git_output
cd /tmp/git_output
git init
git remote add origin /path_or_url_to/git/repo.git
git fetch
git checkout name_of_branch
mv .git /path/to/new/src/
cd /path/to/new/src/
git commit -a
git push
rm -rf /tmp/git_output

Thanks for any help.
Answer: I think it should be possible to delete everything from your working copy (make triple sure to NOT delete your .git folder – make backups!). Then, copy over the contents of your directory B, git add -u (depending on your versoin of Git) to remove missing files from the index and add new files to the index. Commit. Be happy.

Another way I can think of is to initialize a fresh Git repository in your directory B, commit all files, then push to A: cd B; git init; git add .; git commit -m 'complete rewrite'; git push /path/to/A HEAD:rewrite.
Now, in A, create a graft, telling Git that the tip of branch rewrite has the tip of branch master of A as its parent. Then run git filter-branch to make that graft permanent.
Comment: Thanks knittl.  The "-u" bit did catch me out and I found another way to do the same thing.  +1 just for that tidbit.  However the general strategy you mention here matches my option 1.  I had just forgotten to mention in my question the need to delete the original working copy files.  Corrected now.
Comment: @Pyro: Although you don't need a third directory to do the "merging" (if you want to call it that). Unless you do not want to work on the original repository and have sort of a backup that way.
Answer: git checkout A
GIT_WORK_TREE=path/to/B git add -An .   # take out the `n` to actually do it
git commit
git checkout as-you-were

(edit: If you're already on branch A you'll need to do a git reset --hard after to refresh your real worktree. )
You can do this without the checkout if you want to get a bit more lowlevel about it:
(
  export GIT_INDEX_FILE=.git/sideband-index
  export GIT_WORK_TREE=path/to/B
  cp .git/HEAD{,~}
  git symbolic-ref HEAD refs/heads/A
  git add -A .
  git commit
  mv .git/HEAD{~,}
)

Or even
(
  export GIT_INDEX_FILE=`mktemp -u`
  export GIT_WORK_TREE=path/to/B
  git add -A .
  git update-ref A $(git commit-tree -m 'hi there!' -p A $(git write-tree))
)


Can the Runner prevent resources trashing via the "The All-Seeing I" if there is no bad publicity?

Question: The corp does not have any bad publicity tokens and plays the "The All-Seeing I". Can the runner prevent resources from being trashed?
Answer: Yes. Spending the bad publicity is a way to prevent the total effect of All-Seeing I, but it does not state that the trashing cannot be prevented by other means. Cards like Fall Guy and Dummy Box are still able to prevent some of the resources from being trashed, even though they are themselves resources; this ruling can be applied to this situation.
It's also worth noting that if you have a Jarogniew Mercs in play among other resources, it would be left standing after All-Seeing I resolves.
Answer: All-Seeing I just gives an extra option for how to stop the trashing, it doesn't in any way stop the runner from using it's own prevention effects. If your question is can the runner chose to use the remove 1 bad pub when there is no bad pub to remove, the answer there however is definitely not.


Generating passPhrase

Question: Does anyone has idea how metamask generates the passPhrase. I was looking in github for related files but unable to figure out how exactly the things are done.
Answer: The mnemonic key phrase? How is that generated?
I'm not sure how MetaMask generates it. But I can guess that it uses a similar approach to the other standards our there. E.g. BIP 39
For a detailed "how is this done".
Read here:
TL;DR:

You need random data, aka, entropy.
You get enough of that and do fancy computes on said data.
That data is then separate out in a "table" of numbers
These numbers are indexed to a word list (dictionary)
You print out words that corresponde to the indexed numbers

Note: You can further protect, or secure, one's mnemonic by pairing it with a user's passphrase.

[mnemonic] + [passphrase] = [private keys].

This is cool, because, if someone got ahold of your mnemonic, they still could NOT generate your private keys without your unique passphrase.
Comment: Yes I know all the things you wrote above. I was just wondering how I can use metamask like login system, where users only need to enter password to login or may recover account with seed phrase. I guess exodus wallet does the same.
Comment: the password is used to encrypt/decrypt their account on their device.

The seed phrase, aka mnemonic, is generated through entropy at the creation time of the new account.

If you already knew the things above, I'm not clear on what your exact question is. More or less, all the knowledge is there, you just need to implement it.
Comment: yeah man, I got it. I was just confusing with the encryption of account on the device. I thought I can use password to generate mnemonic. thanks a lot

Generating passPhrase


Water in my central vacuuming system?

Question: We have a central vacuum system that was installed in our 4 year old new build. It works perfectly but about 6 months ago we found water in the canister. We assumed our cleaners had accidentally dropped the end of the hose into the pool. We hired an industrial vacuum to suck out all the water (several gallons). All fixed and working well. Then yesterday found water again? Definitely not an accident this time. My husband thinks there is a leak and somehow water is getting into the system but surely we would lose suction? Any other suggestions?
Comment: Do you live in an area of high humidity? Is the canister located in an area where it is in a cool air conditioned space? It is feasible that the vac system may be sucking in hot humid air and that over time the cool canister causes the moisture to condense out of what ever air is left in there when you shut it off. Over a period of time this could build up in a collection of water a few drops at a time.
Comment: Hi Michael, no the opposite; our canister is located in a basement pool plant room which is humid. The rest of the house is not air conditioned and is not humid as we live in the UK.
Answer: We have a problem like this. Our central vacuum unit is located in our detached garage with a pipe going from the garage to the house underground (it's about 20 feet from the house to the garage). We found that the roots of some trees cracked the pipe and water was seeping into the pipe and getting sucked into the canister. Is any of your pipe underground?

Water in my central vacuuming system?


WiFi on my Nexus S no longer works after update to ICS - How can I troubleshoot or fix this?

Question: I just updated My Nexus S to ICS today and everything is working properly except for WiFi. It shows the network's SSID but says it is "Out of range". How can I fix this?
Comment: Are you using the official ICS update for the nexus s? if not official, what ROM are you using? Are you sure there isn't known WiFi issues?
Comment: it doesn't depend on whether you updated manually or via official OTA (look below)
Answer: That's right, this is known issue and you are not alone. Unfortunately there is no official way to fix this. The only way to get your WiFi working properly is to remove your SIM card or use American (USA) sim card.
BTW it doesn't depend on whether you updated manually or via official OTA.
I suppose, the problem is with latest kernel which doesn't support other country codes despite US and EU. The new kernel is getting the country code from SIM card and after finding that it's neither EU nor US it's dropping wifi support. Unfortunately I don't know exactly why.
There are some workarounds however, they require Rooted device. You can install custom ROM's (unsigned!) or use some scripts (from here: http://forum.xda-developers.com/showthread.php?t=1372074&page=7)
You can "star" the issue here: http://code.google.com/p/android/issues/detail?id=23262 so as many people would "star" it as more attention it could get.
People also saying that there are some missing features after upgrading
like:

No Face Unlock.
No Camera Zoom.
No Zero Shutter lag
No Android Beam for Images.

P.S: As far as I know Google stopped providing ICS OTA for Nexus S. I hope they are aware of that issue and working on it.


Does the speed of the air molecules matter in aircraft performance?

Question: Does the fact that air molecules move slower in cold weather and faster in hot weather also affect the aircraft's performance or no? So if its cold there is a higher chance or air molecules hitting the wing and engines because the air molecules are compacted and slow moving and in hot weather they are spread out and faster moving, so less of a chance of air molecules hitting the wings and going into the engine. So in cold weather the molecules move slow and in hot weather they move faster, does this also effect aircraft performance. I know that the fact that in cold air the air is more compacted and that increases aircraft performance but does the fact that it moves slow also have an effect on aircraft performance? Same with hot air, the air is more spread out which reduces aircraft performance but does the fact that the air molecules are moving fast have an effect on aircraft performance?
Answer: In some sense, yes it does.  But we usually don't think about it in those terms.  You usually only need to think about individual air molecules when the object you are talking about is very small.  For example, if you are trying determine the aerodynamics of an airplane whose length is 1/100th diameter of a human hair, then you might start caring about individual air molecules. For realistic sized planes, the planes are so big relative to the air molecules that we can just pretend that air is continuous. So instead of thinking about the motion of individual air molecules, we think about continuous variables such as density and temperature.  i.e. when your air molecules "spread out and faster moving" we say that is a higher temperature with a corresponding lower density, and when they are "compacted and slow moving" we say that is lower temperature and a higher density.  By doing that, we've taken the motion of a quadrillion individual air molecules and reduced it down to one single number. And that one single number, density, does have an affect on aircraft performance.
For completeness, you also sometimes need to consider individual air molecules at very low pressures.  e.g. if your air pressure is a millionth of an atmosphere, then there are not many air molecules to go around and so each individual molecule's motion becomes more significant.  But airplanes generally do not fly at such low pressures.  Even at 40,000 ft, there's a lot more air pressure than that.
Answer: Nice, thick cold air is great for engine performance. Especially for small single engine airplanes.
Hot, less dense air means less performance, making takeoff more of a problem, with longer takeoff rolls needed to get sufficient airspeed to liftoff.
Answer: Yes, of course, but not because of the average speed of the molecules.
Temperature affects density altitude.
Aircraft performance is dependent on density altitude, which considers not only the pressure altitude, (displayed on your altimeter), but air temperature as well. Almost every performance metric for an aircraft is a function of density altitude, which increases as temperature increases, and decreases when it is colder. Lift, drag, engine performance, all are affected by density altitude.
The fact that the air molecules are moving faster when it is hotter is irrelevant, because this speed is the average speed of the molecules. they are moving in all directions, both towards the airfoil, and away from it. So any performance increase from additional relative speed of those air molecules moving towards the wing will be counterbalanced by the performance decrease from those air molecules moving in the same direction as the aircraft, which will be hitting the wing at an equivalently slower speed.


Does Beast Strike Add Strength to damage twice?

Question: The feat Beast Strike allows you to add claw or slam damage to your unarmed strikes. since your strength mod is added to claw or slam damage as well as to unarmed strike does it get added twice?
Answer: No one knows
It was written in a Dragon magazine, definitely never saw anything like errata, and is ambiguous on this point. Basically, it's anyone's guess what they meant. I feel like they probably would have explicitly mentioned something like doubling Strength if they intended that to happen, but there's no real way for me to back that up.
Personally, I could go either way on balance; kind of depends on how the feat was being used. On a Shifter Monk (the case the feat was written for)? Absolutely, go for it, you're a Shifter Monk, you need all the help you can get.
On an eldritch claws Warlock sporting levels in Fist of the Forest, Enlightened Fist, and Shou Disciple, Powerful Build and a size increase, Superior Unarmed Strike, Improved Natural Attack, and Snap Kick? Probably would not be nearly so willing.
In short, ask your DM; a good DM should probably answer your question with another: what are you planning to do with it?
Comment: Well im just a "harmless" Warforged "Monk".
and by harmless i mean Well Built, and by Monk I mean Chaos monk with levels of barbarian added in. really it wasnt much of an "Optimization" Attempt as how can I fit together Monk and Barbarian. Upping the Unarmed Damage came later on in the process.
Comment: @Novian Take that up with your DM.
Answer: Would you say that the damage of a longsword is 1d8 or 1d8+str?
I'd say "claw or slam damage" is the damage die you can find in the description of those attacks, choosen according to your size and modified according to feats that change the dice size (Improved Natural Weapon comes to my mind).
While I have no RAW to support my answer, I think this was the RAI.
Comment: I'd be extremely leery of trying to treat the wording in Beast Strike as definitively anything; I'd houserule Beast Strike itself but would try very hard to avoid any precedent on which that phrasing may mean.
Answer: In other instances of adding entire attack's worth of damage, via such things as Scorpion's Grasp or Imp. Trip + Knockdown, et al, the Str bonus is added twice.  In the ones that don't (Palm Throw, others), this is specifically called out.  Unfortunately, there's very little/almost nothing else that directly adds the damage from one attack to another, without requiring another attack/attack roll, and it's all obscure.  There are instances where Str bonus to damage is replaced (Targeteer Fighter, Control Body) and spells or abilities that add natural attacks seem to assume that the added Str is part of your 'claw damage' or whatever.
Interestingly, the only direct comparison I can think of is Manyshot, which conflates multiple arrow attacks into a single attack roll with multiple sets of damage.  The only thing it mentions in terms of str or damage (composite bows, hank's power bow, that elven bow that adjusts to str), is that you calculate DR and damage separately for each arrow.  Which would seem to indicate that the status quo (bow damage + str if composite + any other modifiers (weapon specialization etc) for determining damage remains.
But really, like always, it depends on your party optimization.  If they are t3+ and know how to swing it, then your t5/4 ass needs the help.  If they're rolling single classed fighters and healbot clerics, just add the die from the slam.
Comment: It's kind of hard to upvote an answer where you admit that you haven't actually read the material. I suggest that you review the text itself to determine whether or not you recall correctly. I *strongly* agree with your second paragraph, and want to upvote, but...
Comment: I have read Beast Strike.  I think it's a cool feat, given that unless you're optimizing it Unarmed Strike is pretty lacklustre compared to the Greatsword crowd, and typically Unarmed Strikers get a raw deal coming and going (with the notable exception of the Unarmed Swordsage, who is a cool guy).

I just didn't have the energy to dredge up examples, which did detract from the quality of the answer in terms of RAW, but I think my last paragraph is all the question really needs.


Why do metals have free electrons?

Question: Throughout my highschool classes, I have been made to learn that metals have free electrons that's why they are able to conduct electricity.. But I never understood why. Is that related to metallic bonding... Correct me if I am wrong but even if that's the case.... I am just not able to understand the concept of free electrons
Comment: Isn't it *mobile* electrons (electrons bound to the metal as a whole) rather than *free* (unbound)?
Comment: @garyp give indistinguishability, degeneracies and a whole lot of electrons crammed in a "small" space to quantum mechanics. Out comes conductivity. I think the effectiveness of free electron models comes from the periodic nature of crystals. Effectively a period boundary condition mimicking an infinite lattice.
Comment: This question is one of the great mysteries of physics.  Why do electrons in metals behave as if they are free when they are swimming a matrix of positive charges?  Others have pointed out that the electrons are *mobile* not *free*.  True, but many of the properties of metals can be explained by a model in which the electrons are really truly free.  It's called *the free electron model*. Others have pointed out that in metals the outermost electrons are loosely bound.  That's part of it, but the reason the free electron model is so good can only be explained by quantum mechanics.(+1 to @Lost)
Comment: I don't think this is even remotely answered until you get to electron orbitals in university.
Comment: There's a "by definition" answer possible: Elements which have free electrons in their usual solid state are called "metals". This is not an unreasonable definition, but there are others. The other definitions typically focus on the properties of metals, which are a result of those free electrons.
Answer: Without getting into the quantum mechanical details, here's a cartoon depiction of what's going on. The vertical axis represents energy.

Like other answers have already pointed out, metals don't have actual free electrons. In the cartoon this is given by the grey region. If electrons have enough energy to be in the grey region, they're free.
In individual independent atoms (gaseous state), the energy levels below a certain energy are discrete. This is depicted by the lines in the cartoon. This means the energy is fixed, rigid. The electrons in this state can't conduct electricity.
In solids however, the discrete states of multiple neighbouring atoms "merge" into a continuum and create what is called as bands. For further details you may look at my answers here.
With this, there exist a continuum of states called the conduction band where the electrons are not bound to any single atom of the solid. They are mobile. The fascinating property of these states is that it is possible for electrons to respond to an external electric field. These states are called Bloch waves.
In insulators there is a big energy gap between the filled states (valence) and the empty states (conduction). So without sufficient external field, they are unable to conduct electricity.
In metals however, the energy gap is absent and thus electrons can easily go into the conduction band and respond to external electric field.

Some details
The reason why mobile electrons seem like free electrons has to do with crystal symmetries. Specifically translational symmetry. In a crystal the atoms are arranged in a regular periodic manner. In the bulk (non boundary) of the metal if you go from one atom to another, the neighbourhood looks identical. This is known as translational symmetry. And a consequence of this is that the electrons have well defined momentum, just as a free electron does. This is encapsulated in the band structure.
Comment: This is a phenomenal explanation — could you perchance add a little bit about semiconductors too?
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/112375/discussion-on-answer-by-superfast-jellyfish-why-do-metals-have-free-electrons).
Answer: In high school classes , free electrons is used interchangeably with mobile electrons even though they are not exactly same. Free electron is an electron is essentially out of the electron -positive site bound system. While mobile electrons are those which are loosely bound to the positive site so even though they are not free from the positive site's influence they can essentially hover above other positive sites among the sea of electrons in such a way that as a whole the conductor has no charge.
For example consider the electron of a Bohr hydrogen atom. If its given energy exactly equal to its ground state energy it becomes free in the sense that it is not bound to the nucleus any longer , if given any more energy whole of it will appear as KE.
On the other hand conductors have many orbits and the electrons in the last orbits are loosely bound to the nucleus due to screening and also because they are far from the nucleus. These are mobile electrons. But your book is calling them free electrons. Since these are loosely bound they can easily constitute a current.
Comment: You, of course, are right to point out the ambiguity in the term "free electron". I like "mobile electron" as a more rigorous alternative, although I'll admit that I have written "free electron" to refer to the mobile charges in a metal in reputable physics journals. So, it is a common usage in the professional community, not merely a euphemism in high-school texts.
Answer: I am afraid that the answer is not high-school level at all, let me try to explain anyway.
First of all, we talk about free electrons when they can move freely in space without external forces acting on them. Also we assume that they do not interact with one another (this is really tricky because they are charged particles, but I won't discuss this assumption).
Clearly in a metal there is a crystal made of ions that acts with external forces on the electrons. However it turns out that the electrons with higher energy act as if they were free electrons, and since only the electrons with higher energy are responsible for conduction, we can treat metals as free electrons systems.
Technical details
Free electrons have energy levels described by the dispersion relation $\varepsilon_k = \hbar^2k^2/2m$, where $m$ is the mass and $k$ is the momentum. At zero temperature the particles occupy all the available electronic states from $k=0$ up to $k=k_F$, known as Fermi momentum, corresponding to an energy $\varepsilon_F=\hbar^2k_F^2/2m$ and when $k\sim k_F$ the dispersion relation is approximately linear in momentum $\varepsilon_k \sim \varepsilon_F + \hbar^2k_F(k-k_F)/m$.
When electrons are bounded by a periodic potential as in metals, the dispersion relation changes completely, in particular one can prove that for a one dimensional lattice with step $a$ the dispersion relation reads $\varepsilon_k = \mp 2t \cos{(ka)}$, where $k$ lies in the first (reduced) Brillouin zone $k \in ]-\pi/2a,+\pi/2a]$ and $t$ is called hopping and it's given by $t = \hbar^2 \eta /2ma^2$, $\eta$ being a dimensionless parameter which depends on the specific ions. You can plot the dispersion relation as an exercise. At zero temperature the electrons occupy all the energy states described by $-2t \cos{(ka)}$ and thus the Fermi momentum is $k_F = \pi/2a$ and the Fermi energy $\varepsilon_F=0$. Now you can expand the dispersion relation close to the Fermi momentum and you get $\varepsilon_k \sim 2t (k - k_F)a = \hbar^2 \eta (k-k_F)/m a$. You can easily rewrite the latter formula as $\varepsilon_k = \varepsilon_F + \hbar^2 k_F(k-k_F)/m^*$, where $m^* = (\pi/2\eta)m$.
As you can see, close to the Fermi level the dispersion relation of bounded electrons is formally equivalent to that of Free electrons with an effective mass $m^*$. Now since only electrons close to the Fermi level are affected by excitations, scattering process etc. due to Pauli exclusion principle, you can see that the "important" electrons can be treated as if they were free electrons with some effective mass. This is precisely the reason why the free electron model describes quite well the properties of metals. Finally notice that insulators and semiconductors have completely different dispersion relations, so this similarity is no longer true.
Comment: is this the same k as in crystallography, the wave vector?
Comment: Yes, to be very precise it is often called quasi-momentum and it represents the quantum number associated to the translational symmetry of the system
Answer: Without getting too far away from the high school level: the electrons in metals are not really free. But they are free to move in the sense that there are energy states where they can jump, if an electric field is applied.
If you are comfortable with the concept of a hole as a unfilled chemical bond between ions (as it is explained in high school physics) than a metal can be thought of as a semiconductor with lots of holes, so that thinking of them as particles doesn't make sense.
Update
To expand the second paragraph above:

Let us first think of a covalent bond in a hydrogen atom: two electrons (one from each atom) are shared by the two atoms.
Carbon can form four such bonds, which is why it can form complex
chained and branched molecules. In a diamond each carbon atom is
bound to four other atoms - we say that its bonds are saturated in
the sense that all the electrons a participating in bonds in order to  hold the crystal together, i.e. none of the electrons a "free".
One way to think of a metal is as of a material were some of the electrons are not participating in bonding.
Let us consider semiconductors, such as silicon or Germanium - they are in the same group as carbon in the periodic table and form diamond-like crystals with saturated bonds. If one bond is broken, an electron (or even two) is liberated and start wondering around crystal - this is a "free" electron. We also have left an empty space - a hole. An electron from another bond can jump into the empty space, which can be though of as the hole moving.
If we replace some of the Si/Ge atoms by atoms with more or less than four valence electrons, we will have a material with inherently more electrons or more holes than a pristine semiconductor. We refer to it as n-type or p-type semiconductors, depending on whether electrons or wholes are in excess.
A metal than can be thought of as a n-type semiconductor with lots of excess electrons. (One rarely speaks of excess holes, since the concept of a hole doesn't really make sense in this case).
Comment: High school carricula may differ, especially in different countries. However, logically I would expect pn-junction (conducting electricity in one direction) come after holes (p-type semiconductors). Anyhow, I tried to give an explanation without discussing the band structure, which is certainly beyond high school level.
Comment: I went to high school a long time ago, but I'm pretty sure I didn't get taught *"the concept of a hole as a unfilled chemical bond between ions"*.  I don't think semi-conductors were explained as anything other than "conductors that can only conduct electricity in one direction"
Comment: @Flydog57 I'm surprised you were taught anything about semiconductors at ll in high school
Comment: Ok, it may have been "junior college" (in Quebec, Canada you go through a two year college program before university)
Comment: @Flydog57 I expanded the "high-school explanation" in terms of holes in my answer.
Answer: Let us put it like this: the lattice structure typical of a piece of metal causes the outer orbital electrons of the metal atoms to behave as if they were owned by all the atoms of the metallic lattice structure in common, rather than by each individual atom. The consequence is the "loosening" and de-individualization of each electron from its place in what would have been its original electron cloud.
I think this is the simplest answer which can be given.
Comment: This lattice structure (aka crystal) is not proper to metals. And furthermore, is not even required to have band structures, a Fermi surface, and more importantly, free electrons.
Answer: You are asking for an explanation, and as we can see from the other answers, there are no understandable explanations.
Here is a description at a simple level.
Take a flat piece of glass and a flat piece of gold. Touch them together, and then pull them apart. The glass will have a positive charge, because the gold atoms hold onto electrons better than some kind of atoms in the glass. That's true for any two materials, though some are almost equal in their ability to hold on.
Ranking materials
Suppose you used polyurethane instead of gold. It is even better at grabbing electrons. But there is a difference. The electrons the polyurethane grabs are stuck where they are. Other atoms in the polyurethane have a hard time taking them from the ones that first got them from the glass. It takes a long time for the electrons to leak away. But the gold passes electrons from one gold atom to another very readily.
Different materials do that at different speeds, and resist electron movement to different degrees. Manganese has around 80 times the resistance of silver. Amorphous sulfur resists $10^{23}$ times as much.
Resistance of elements
It's more complicated than just elements -- carbon has different resistance in diamond form than as graphene, etc.
And alloys or chemical compounds resist in ways that can be unintuitive.
What causes the difference? I couldn't begin to say. Superfast Jellyfish provided a description with a picture. You can see the bands overlapping. That is another description of what happens. It doesn't say anything about what makes the bands overlap.
It's possible that someone with a godlike understanding of quantum mechanics could work out the equations for each element and chemical compound from first principles, and understand how the QM gives rise to those bands, and understand what parts of the math result in conductivity.
But I strongly suspect that such a person could not explain it to mortals. And it's hard to understand even what "understanding" means at that level.

Why do metals have free electrons?


To add: which should I use 新增, 添加or增添?

Question: I mostly hear 增添 in most contexts, but lately have come across 新增 and 添加. What are the differences in tone and register?
Comment: iciba:新增:newly increased 、添加:add; append; adjunction; superinduce、增添:add; increase; lend; superinduce, this would indicate that 新增 functions as adjective, whereas the other two function as verb or noun, suggesting not to use the 1st  for "add"
Answer: These words are very similar in meaning. There are some more variants like 添加,加添,添增……
新增 is generally used in the sense of "add a new feature", often in the context of software. However, it can also substitute for other variants of "add". It puts more emphasis on the fact that something has changed, rather than what has been added.
新增 is often used as an adjective.
增加 tends to be used with things that can be expressed in numbers, like money, weight and so on. 增添 is more commonly used for more abstract things like content or effort. However, it's not wrong to switch them around.
添加 seems a bit more formal, more likely to appear in written language. It's often used for sentences like
<code>牙膏中添加少量的氟化物
some fluoride is added to toothpaste
</code>
... and other food-related expressions.

To add: which should I use 新增, 添加or增添?


Can't add intermediate cert to ca-certificates.crt via /usr/local/share/ca-certificates

Question: On Ubuntu 14.04.2 LTS, I'm attempting to add an intermediate cert to the system's store of trusted CA certs. I installed the .crt file in /usr/local/share/ca-certificates, then ran update-ca-certificates. The symlink was created from /etc/ssl/certs to the .crt. However, the cert was not included into /etc/ssl/certs/ca-certificates.crt.
Man page for update-ca-certificates says:

update-ca-certificates  is  a  program  that  updates   the   directory
  /etc/ssl/certs to hold SSL certificates and generates certificates.crt,
  a concatenated single-file list of certificates.
It reads the file /etc/ca-certificates.conf. Each line gives a pathname
  of  a  CA  certificate  under /usr/share/ca-certificates that should be
  trusted.  Lines that begin with "#" are comment lines and thus ignored.
  Lines  that  begin with "!" are deselected, causing the deactivation of
  the CA certificate in question.
Furthermore   all   certificates   found   below   /usr/local/share/ca-
  certificates are also included as implicitly trusted.

I was able to get the cert into ca-certificates.crt by editing the /etc/ca-certificates.conf file and giving the path to the cert, then running update-ca-certificates.  So my question is: is the man page wrong and does the /usr/local/share/ca-certificates method not work?  Or did I miss a trick?
Thanks!
Answer: Works for me. Did you install the certificate in /usr/local/share/ca-certificates with suffix .crt? This is the part in the update-ca-certificates script, which adds certs from LOCALCERTSDIR:
if [ -d "$LOCALCERTSDIR" ]
then
  find -L "$LOCALCERTSDIR" -type f -name '*.crt' | sort | while read crt
  do
    add "$crt"
  done
fi

You might want to check if LOCALCERTSDIR is set to the /usr/local/share/ca-certificates directory. After running update-ca-certificates I got a link from /etc/ssl/certs/xyz.pem to $LOCALCERTSDIR/xyz.crt and its content has been added to the /etc/ssl/certs/ca-certificates.crt. Hope this helps!


What was done with animals WITH defects?

Question: A quick search reveals that the phrase "without defect" appears at least 46 times in the Old Testament. What happened to the animals that had defects? What is a defect, and were they fit for consumption by people?
Comment: In the 46 examples, were any in a context of other than offerings for sacrifice?
Answer: I think Malachi offers a little more insight into this:

When you offer blind animals in sacrifice, is that not evil? And when you offer those that are lame or sick, is that not evil? Present that to your governor; will he accept you or show you favor? says the LORD of hosts. - Malachi 1:8 ESV

These are animals that would not be eaten or bred due to illness or other problems.  The idea is that it's not really a sacrifice if it has little value to begin with.
Comment: That passage seems to me to be talking about particularly egregious defects.  What about those with minor defects, as presumably most would have had?
Comment: Good question.  That passage in Malachi is the only biblical source I know of that begins to eloaborate on  the idea at all.  Deuteronomy 17:1 hits on the idea of simple blemishes, but is fairly silent on the why aspect.
Answer: What is an animal with a defect?
According to Deuteronomy 15:21 (NIV) lameness or blindness would be considered a defect. In my personal experience around cattle not having both testicles is a defect. So to protect the quality of your herd you wouldn't want to breed that animal back into the herd. It would however be o.k. for consumption. Even though I don't have anything to reference this too an illness and a defect would be two different things. Obviously you wouldn't want to eat a sick or ill animal.
What would they do with these animals with defects, and could they eat them?
According to Deuteronomy 15:22-23 (NIV) You are to eat it (the animals with the defect) in your own towns. Both the ceremonially unclean and the clean may eat it, as if it were a gazelle or a deer. 23 But you must not eat the blood; pour it on the ground like water.
So just because it wasn't acceptable for sacrifice doesn't mean the animals with defects were wasted or destroyed. Waste not want not!
Comment: Good find in Deut 15:22!


Can the program determine the frequency of the CPU or is it impossible?

Question: In order to understand the question, imagine a simple situation. Alice tells Bob that her CPU's frequency is X Hz. Bob does not take her word for it. Bob can not meet with Alice and check what frequency her processor really has. Can Bob send her a soft program that accurately determines the frequency of Alice's CPU? Is such a program possible or not in principle?
Answer: In these days of superscalar, multicore, virtualisation, power scaling, managed operating systems, and so on, what does "CPU frequency" even mean?
Note that it may be possible for Alice to convince Bob that she has compute power capable of performing X operations of a known type in a given time, as you find in a proof-of-work system. If it is a problem for which parallel algorithms are believed not to be feasible, he may be convinced that it happened on a single compute device, and not (say) a cloud or cluster.
But for all Bob knows, Alice may have an asynchronous device which doesn't even have a clock speed.
Answer: In certain very specific situations, you might be able to use software-based attestation.  See, e.g., the following seminal paper:

Pioneer: Verifying Code Integrity and Enforcing Untampered Code Execution on Legacy Systems.  Arvind Seshadri, Mark Luk, Adrian Perrig, Leendert van Doorn, and Pradeep Khosla.  Originally in SOSP 2005.

Roughly speaking, it tries to prove that Alice's processor is at least as fast as claimed (but the actual guarantees are more interesting and the properties and assumptions are more complex).  Read the paper for details to see if it is what you are looking for.


Can Scrum be used in non-development activities?

Question: Our company has recently implemented Scrum in the development process, and it seems to be somewhat successful. They are now suggesting that we carry it over to other activities within the company such as software implementation where many of the activities are totally outside of our control, i.e. the customer does not provide information on the schedule you set. Is Scrum really applicable here?
Answer: In order to accomplish Scrum, the following conditions must be met:

There must be buy-in from upper management (based on your question, you already have this)
There must be buy-in from the Team
There must be a Scrummaster who understands Scrum and is empowered to be its evangelist
There must be a Product Owner who is authorized and empowered to make decisions on behalf of the customer (it sounds like this may be your sticking point)
The work must be such that a potentially shippable product can be produced with each iteration
The work must be estimable (difficult-to-estimate work is fine, but if the nature of the work is such that it cannot be estimated, then you cannot do Scrum)
The team must be cross-functional (note that this is not a team where every member can do everything. Rather, it is a team that is capable of doing everything)

While most commonly used for software development, there's nothing inherent to Scrum that makes it bound solely to software development. If you can fulfill the above requirements, then you should be able to implement Scrum successfully. If you cannot fulfill the above requirements, then it's time to re-assess.
Answer: Non-Software Scrum Exists, But...
Scrum can be used for projects (as opposed to ongoing activities) outside of software development. However, in my experience adapting Scrum to administrative or other non-software projects requires a great deal more maturity and adaptability than your organization probably has if your current Scrum implementation is only "somewhat successful."
Aside from the fact that you don't consider your current implementation to be fully successful, another red flag is that you talk about the customer not providing information (of whatever sort) on a set schedule. This seems like legacy, top-down command-and-control rather than either agile collaboration or Scrum time-boxing.
Some Simple Considerations for Success
Here are five additional points you should keep in mind in order to implement customer-facing Scrum well:

Decide whether you have a project or an ongoing business activity.
Make sure you have the organizational experience with Scrum to make it successful where it's already been applied before attempting to extend it into other domains.
Plan how you will interact with customers in iterative delivery cycles.
Modify your processes to integrate ongoing customer collaboration rather than tail-end feedback.
Define communications plans for broken feedback loops, or feedback loops that that exceed your iteration time-boxes.

This isn't dramatically different from Scrum for software development, or Scrum implementations where the "customer" is internal to the business. In any Scrum implementation, communication, transparency, and continuous collaboration are always essential elements. These elements just take on a little more urgency when you are dealing directly with customer-facing delivery.


Can't Install Python 2.7.3 on CentOS 6

Question: I have a CentOS 6 (minimum install or netinstall, I can't remember which) on a virtual machine. I'm trying to install Plone 4.2.4 on it for testing purposes. I have installed all the required dependencies, or at leat I think so.
I run the Plone Unified Installer (I use the --static-lxml option because Plone requires a libxml2 version not present on CentOS)

./install.sh --static-lxml standalone

I get the following error:
Stand-Alone Zope Instance selected

Detailed installation log being written to /root/plone/Plone-4.2.4-UnifiedInstaller/install.log

Root install method chosen. Will install for use by system user plone

Installing Plone 4.2.4 at /usr/local/Plone

User 'plone' already exists. No need to create it.
Skipping libjpeg build
Skipping readline build
Installing Python-2.7.3. This takes a while...
Install of Python-2.7.3 has failed.

Installation has failed.
See the detailed installation log at /root/plone/Plone-4.2.4-UnifiedInstaller/install.log
to determine the cause.

Here's the Plone install log.
I installed Pythonbrew to try to install Python 2.73 using it. I can sucessfuly install Pythonbrew, but when I run pythonbrew install 2.7.3 I get the following error:
[test@plonemachine root]$ pythonbrew install 2.7.3
Use the previously fetched /home/test/.pythonbrew/dists/Python-2.7.3.tgz
Extracting Python-2.7.3.tgz into /home/test/.pythonbrew/build/Python-2.7.3

This could take a while. You can run the following command on another shell to track the status:
  tail -f "/home/test/.pythonbrew/log/build.log"

Patching Python-2.7.3
Installing Python-2.7.3 into /home/test/.pythonbrew/pythons/Python-2.7.3
ERROR: Failed to install Python-2.7.3. See /home/test/.pythonbrew/log/build.log to see why.

Here's the Pythonbrew build log. It's almost identical to the Plone install log(!), leading me to believe the problem lies somewhere else.
Answer: It looks like the configure script exited correctly and the Makefiles were created. My guess is that you are missing some of the basic development tools, perhaps autoconf. Try installing them with this command as root (source):
 yum groupinstall 'Development Tools'

Can't Install Python 2.7.3 on CentOS 6


Is there any way to show that authors are equal in arxiv names?

Question: I have a paper which the first two authors are contributed equally, is there any way to show in arxiv page (or scholar page) that authors are equal? Maybe a star on names in submit names or something.
thanks.
Comment: What field are you in? Some fields don't pay attention to authorship priority. For example, mathematics generally doesn't do authorship priority. If you want to put in some sort of priority notice it is probably best to do so somehow inside the file itself, such as a footnote simply stating that neither author should be considered a second author.
Comment: Yes, there is a way on google scholar - you can add a * next to the name of all first-authors by manually editing the entry! Citations will be kept
Answer: There does not appear to be any facility presently in these archives of papers to indicate that contribution of both authors was equal.  (I suspect that this is mostly because it is not actually specified in most papers, so it would rarely be able to be known from reading the papers.)  In the absence of this, the best fall-back position is to specify this explicitly in the paper with a statement of contributions.  Some journals are starting to require this anyway, particularly for research papers submitted by teams of people.  There is no reason that you could not add it into your paper if you wish to specify the contributions of the authors.
In regard to this issue, it is worth noting that, except in a relatively small number of cases, the ordering of authors is generally weak information about the magnitude of their contributions to a paper.  Conventions and interpretation of the significance of authorship order differs by field.  In some fields it would be assumed that earlier authors did the majority of the work, and in other fields there is no such assumption.  The main time when you would infer higher contribution from earlier listing is when you have a paper where the first author is a PhD student at a university, and the later authors are academics in the same department, in which case this is usually a paper where the student has done most of the substantive work and the latter are supervisors who have contributed advice, reviews, etc.  In most other cases it is difficult to infer contributions solely from the ordering of the authors.
Answer: No, there are not any options for indicating equal authorship in e.g., Google Scholar or arXiv, yet. Perhaps this is something to pitch to Google and others.
Comment: Pitch to Google? I doubt they would ever make a reliable service for adding metadata like this to papers. Google Scholar works mostly because it is doing what they're already good at (search engine, heuristics, profile pages), so it likely comes fairly cheap to Google. They've been asked many times to let authors enhance it with metadata (e.g. because heuristics often get things wrong), and they have never responded to such requests. Academia hasn't been google's priority customer base for ages.
Comment: Notice there is the phrase, "and others".
Answer: There is no specific mechanism for doing this, but arxiv submissions do allow you to add comments, which can be seen by anyone who looks at your abstract. You could write "X and Y contributed equally to this work" there if you like. This is not an especially common thing to do in my experience, but people do do it, as you can see here:link to arxiv search
Answer: If authors are listed alphabetically and you are in pure math or similar fields, people will assume the contributions are equal.  If you are in another field where alphabetical ordering is not the standard, a common practice is to include a footnote stating that authors are listed alphabetically.


Install imagemagick on windows with xampp

Question: I really need to get imagemagick working on my windows xampp installation, I havent been able to find any good tutorials on how to do it though, can anyone help?
Answer: Assuming you have this part done:
1)  Download and install XAMPP
2)  Download and install ImageMagick.

Confirm its working:
1)  Start XAMPP
2)  Run this code in your browser to prove ImageMagick is installed (and working).

<?php
header("Content-Type: text/plain");
system("convert -version");
?>

3)  If the above works then you should be able to run code like this (in your browser):

<?php
exec("convert infile.jpg -thumbnail 100x100 outfile.jpg");
?>

Answer: Does XAMPP come with ActiveState Perl or Strawberry Perl or some other??
XAMPP may not come with ImageMagick installed by default, which is highly likely, I would just run the Perl updater tool for XAMPP to get the ImageMagick package and compile it into your environment.  I don't know much about XAMPP and so this advice only gives you a little milage on your answer.
Answer: Normally your web script needs to know wher to find the ImageMagick executables. You can try just adding that path to the PATH environment variable for the user running Apache. Better yet, and this is more common, the web app will normally have some form of config file which needs to have the path to the executables entered in.
Answer: ImageMagick 6.9.2-3 Q16 x86 Install on
xampp win32 5.6.12-0-VC11 on a
64-bit Windows 7 Ultimate System
32-bit xampp was installed at c:/xampp--its install warning NOT to install it in a Program Files directory was a bit cryptic, as if written by a non-native English speaker.
xampp expects imagemagick to be installed at its root, which is at c:/xampp/htdocs/xampp, not at Window's root, /.
I installed the 32-bit ImageMagick directory at that location, then ran the two tests suggested by KPWINC. Use them.
I installed both 32-bit packages of xampp and ImageMagick on my 64-bit Windows 7 Ultimate system, hearing too many problems brought on by the 64-bit versions.
Dr D0UG