I confess, I didn't jump on the Stackoverflow bandwagon when everyone else did. I've recently signed up and I have a reputation of 176 on stackoverflow.com. To my surprise, I now find that I need 20 to be able to participate in Chat. Is this 20 regarding meta.stackoverflow.com? I find it odd that when signing up it detects my Stackoverflow account and associated me yet ignores reputation.   What happens if I have absolutely zero interest in meta? I understood the chat is irrelevant of meta itself or was I wrong?
I get the point of having a minimum reputation to use the new chat feature. However, I was hoping my 2K reputation from Stack Overflow would be enough - but it looks like I need to acquire 20 rep here on Meta Stack Exchange.  So my question is - should this restriction be moved?
How do you compute the earth's radius at a given geodetic latitude? Generating random numbers without repetitions Migrate from a virtual machine (VM) to a physical system Changing top, bottom, left & right margins on the fly I’m trying to find a way of being able to modify all of the margins of a page whenever I want to and as many times as I want to on a single page in order to be able to put text very easily where I want on a page.   I have thought of using the geometry package and using   \newgeometry{left=6.75cm, right=1cm, top=1cm, bottom=1cm}  %…  \restoregeometry   but unfortunately this only works for whole pages, so I can only change the margins once per page (and then they are valid for the whole page without having the possibility of changing them again).   I found the following script on the internet which enables users to change margins on the fly, just as I want to. The code below works fine and enables me to change the left and right margins of my page as many times as I want to, but unfortunately, it doesn’t give me the option of changing the top and bottom margins.  % placed before \begin{document}  \newenvironment{changemargin}[2]{% \begin{list}{}{% \setlength{\leftmargin}{#1}% \setlength{\rightmargin}{#2}% }% \item[]} {\end{list}}  % And then inside the document, whenever I want to use % the command to change the margins on the current page  \begin{changemargin}{1.9875cm}{-3.7625cm} % this means the left margin increases by 1.9875cm compared % to the default left margin (4.7625cm) (so left margin=6.75cm here) % and the right margin decreases by 3.7625cm (so right margin=1cm)  % ... (text or pictures in new environment)  \end{changemargin}   For this reason, I tried to adapt the code above and came up with the code below:  % placed before \begin{document} \newenvironment{changemargin}[3]{% \begin{list}{}{% \setlength{\leftmargin}{#1}% \setlength{\rightmargin}{#2}% \setlength{\topmargin}{#3}% }% \item[]} {\end{list}}  % And then to use the command: \begin{changemargin}{1.9875cm}{-3.7625cm}{1cm} % ... \end{changemargin}   It compiles and still changes the left and right margins but the top margin remains unchanged. (I haven’t yet tried to change the bottom margin).  Can anyone help me get this code to work completely, and enable me to modify the left, right, top and bottom margins of a page? Thanks. I have the following pieces of hardware I would like to network mostly for file sharing (media primarily): 1 gaming laptop, 1 i7 (2.3Tb storage) desktop, 1 P4 desktop (500g storage), and 1 250gig PS3.  I am looking to setup a linux host (with a PS3 media server) with the i7 desktop but am concerned about leaving it on all the time. What stripped down, low energy usage distro can I couple with which windows &amp; PS3 friendly software?  Also, how should i reformat my i7 (in terms of partitions, RAID options, whatever)? It has 2 1Tb drives (likely adding a third), and 1 320 gig. scheduled event My MATLAB launcher doesn't work I've installed MATLAB R2011a on Ubuntu 11.10 today following . I've also followed the steps to create the launcher. It appeared, but when I click on it nothing happens. Does anyone knows what can I do to fix it? Additional info I can run it perfectly through terminal. My only problem is getting the launcher to work. To create the launcher I used :   Get an icon:  sudo wget http://upload.wikimedia.org/wikipedia/commons/2/21/Matlab_Logo.png -O /usr/share/icons/matlab.png   Get the launcher file:  sudo wget 'https://help.ubuntu.com/community/MATLAB?action=AttachFile&amp;do=get&amp;target=matlab-r2011a.desktop' -O /usr/share/applications/matlab.desktop Norm $N$ on $\Bbb Z[\sqrt d]$ is multiplicative, $N(x)$ prime $\Rightarrow x$ irreducible Outlook: scheduling recurring out-of-office? In Outlook, is there a way (or an add-on that can do it) to schedule a recurring out-of-office message?  I work 4 10's, so I'm out of the office every Monday, and it's a bit of a pain to have to reset my out-of-office message every single week. Evaluate $\lim\limits_{n\to\infty}\frac{\sum_{k=1}^n k^m}{n^{m+1}}$ By considering:  $$\lim_{n\to\infty}\frac{\sum_{k=1}^n k^1}{n^{2}} = \frac 1 2$$ $$\lim_{n\to\infty}\frac{\sum_{k=1}^n k^2}{n^{3}} = \frac 1 3$$ $$\lim_{n\to\infty}\frac{\sum_{k=1}^n k^3}{n^{4}} = \frac 1 4$$  Determine if this is true: $$\lim_{n\to\infty}\frac{\sum_{k=1}^n k^m}{n^{m+1}} = \frac 1 {{m+1}}$$  If it is, prove it.  If it is not, evaluate $\lim\limits_{n\to\infty}\frac{\sum_{k=1}^n k^m}{{m+1}}$. Trying to remember the name of a grade-school book about an alien in a cereal box When I was a kid (Grade school, Elementary, can't remember the exact grade, but it was between 1992 and 1999) I read a book about a kid who found an alien in his cereal.  This alien informed him that he was there to defeat an evil threat to Earth, that took the form of the school's most popular student.  The alien came with a gun that did nothing, and the alien in the popular kid disguise had the power to make the kid's fingernails bleed by damaging his nerve endings.  In the end, it was revealed that the evil alien had a huge craving for, and vulnerability towards, pizza flakes, and was defeated by gorging himself on them and then exploding. I have connected speakers to the back panel of my computer at work and I would like to have them always enabled (I can switch them off on the speaker casing). However when I connect headphones on the front panel system automatically says that the rear output is unplugged.  I found a solution to disable auto detection with Alsamixer and it works almost ok except the fact that after system restart I need to reconfigure the settings again... How can I set this once and forget about it? Does the new guidance on duplicate questions suggest closing a question as duplicate, if the original answers the OP's question? In other words, should we now look at the content of the answers when we are evaluating questions for possible duplication?  Is it sufficient to say "Your answer can be found in this question over here, therefore your question is a duplicate?"  The new guidance is here:    Among other things, it describes the new close banner:     This question already has an answer here:   Link to the Duplicate Question   ... which seems to suggest that, if some other question in the system answers the OP's question, then the OP's question can be closed as a duplicate on that basis (even if the question itself is not necessarily duplicated).  Example Here:    Note the comments below the question, where I dispute the assertion made there that it is a duplicate question.  The original question doesn't mention unit testing. (I was requested to edit the question to explain why it is different that a proposed duplicate question. This seems counterproductive to do here, inside the question it self, but that is what I have been asked by the site and moderators. There is no way for me to vote against their votes. So, here I go: Please stop voting this as a duplicate so quickly, which will eventually lead to this question being closed off. Yes, the other question linked to asks the same math, but any newcomer to the problem who was exposed to it via physics, as I was, will prefer this question instead of the one that is purely mathematically. I beg the moderators to not be pedantic on this one. This question spills into physics, which is why I did the cross post to the physics forum as well.)  How does the sum of the series “1 + 2 + 3 + 4 + 5 + 6…” to infinity = “-1/12”, in the context of physics?  I heard Lawrence Krauss say this once during a debate with Hamza Tzortzis (). I found a transcript of another debate between Krauss and William Lane Craig which has the same sum. Here is the paragraph in full:     Let’s go to some of the things Dr. Craig talked about. In fact, the   existence of infinity, which he talked about which is   self-contradictory, is not self-contradictory at all. Mathematicians   know precisely how to deal with infinity; so do physicists. We rely on   infinities. In fact, there’s a field of mathematics called “Complex   Variables” which is the basis of much of modern physics, from   electro-magnetism to quantum mechanics and beyond, where in fact we   learn to deal with infinity; without the infinities we couldn’t do the   physics. We know how to sum infinite series because we can do complex   analysis. Mathematicians have taught us how. It’s strange and very   unappetizing, and in fact you can sum things that look ridiculous. For   example, if you sum the series, “1 + 2 + 3 + 4 + 5 + 6…” to infinity,   what’s the answer? “-1/12.” You don’t like it? Too bad! The   mathematics is consistent if we assign that. The world is the way it   is whether we like it or not.   -- Lawrence Krauss, debating William Lane Craig, March 30, 2011  Source:   CROSS POST: I'm not sure if I should post this in mathematics or physics, so I posted it in both. Cross post:   EDIT: I did not mean to begin a debate on why Krauss said this. I only wished to understand this interesting math. He was likely trying to showcase Craig's lack of understanding of mathematics or logic or physics or something. Whatever his purpose can be determined from the context of the full script that I linked to above. Anyone who is interested, please do. Please do not judge him out of context. Since I have watched one of these debates, I understand the context and do not hold the lack of a full breakdown as being ignorant. Keep in mind the debate I heard this in was different from the debate above. The cube of any number not a multiple of $7$, will equal one more or one less than a multiple of $7$ Yeah so I'm kind of stuck on this problem, and I have two questions.   Is there a way to define a number mathematically so that it cannot be a multiple of $7$? I know $7k+1,\ 7k+2,\ 7k+3,\ \cdots$, but that will take ages to prove for each case.  Is this a proof? $$(7k + a)^3 \equiv (0\cdot k + a)^3 \equiv a^3 \bmod 7$$    Thank you. I can always find that in some articles the production of higgs decay written as &quot;$\rm H\to {ZZ}^*\to 4l$&quot;, &quot;$\rm H\to ZZ\to 4l$&quot;, &quot;$\rm H\to Z\gamma^*\to\ldots$” What dose it mean when some particles with a superscript *? Such as “$\rm Z^*, W^*, \gamma^*, \ldots$&quot;. What’s the difference between them and &quot;$\rm Z, W, \gamma$&quot;? Any reason to have a strong user password? I recently decided to change my (very) strong user password to something trivial.  This was mostly to eliminate frustration with typing a long password each time I sudo or whatever.  My question is, is there any reason to have a strong user password? considering that most services which I run on my box do not use PAM for auth:   apache2 - uses .htpasswd for access   sshd - only private keys allowed   transmissiond - uses its own http auth   mpd - uses its own auth   samba - limited to LAN   Physical access to the box is out of the question. How do major and minor grooves arise in the DNA helix? I understand that they arise due to the pairing of bases of two opposite stands and are sites through which important proteins needed for replication and transcription of DNA interact. But I don't get how the arrangement of bases really generate the grooves. I have the following configuration, but I have not able to find any documentation on how to set a maximum backup files on date rolling style.  I know that you can do this with size rolling style by using the maxSizeRollBackups.  &lt;appender name="AppLogFileAppender" type="log4net.Appender.RollingFileAppender"&gt;     &lt;file value="mylog.log" /&gt;     &lt;appendToFile value="true" /&gt;     &lt;lockingModel type="log4net.Appender.FileAppender+MinimalLock" /&gt;     &lt;rollingStyle value="Date" /&gt;     &lt;datePattern value=".yyMMdd.'log'" /&gt;     &lt;layout type="log4net.Layout.PatternLayout"&gt;       &lt;conversionPattern value="%d %-5p %c - %m%n"  /&gt;     &lt;/layout&gt; &lt;/appender&gt; How can top principal components retain the predictive power on a dependent variable (or even lead to better predictions)?