How to convert “ Sun May 31 23:59:00 EDT 2015” to 31/05/2015?
Where can I find documentation on formatting a date in JavaScript?
Good reading on the Keldysh formalism I'd like some suggestions for good reading materials on the Keldysh formalism in the condensed matter physics community. I'm familiar with the imaginary time, coherent state, and path integral formalisms, but lately, I've been seeing Keldysh more and more in papers. My understanding is that it is superior to the imaginary time formalism at least in that one can evaluate non-equilibrium expectations. Deployed web parts don't show up in Web Part Gallery Navigation to section/subsection from Beamer headline titles Beamer infolines themes, like CambridgeUS, insert the titles of the current section and subsection in the headline. These titles appear to be clickable (the screen pointer changes as if they were so) but nothing happens when one clicks them.   Is there a way to link the headline titles to the first frame of the corresponding section or subsection? Something like this already works on the theme footline: clicking on the presentation title takes you to the title page.   Edit: MWE  \documentclass{beamer} \usetheme{CambridgeUS}  \setbeamertemplate{navigation symbols}{} \title{Click on Headline} \author{A.~U.~Thor} \institute{X-University} \date{2015} \begin{document} \begin{frame}   \titlepage \end{frame} \begin{frame}[t]{Contents}   \tableofcontents[subsectionstyle=hide]  \end{frame} \section{Section 1} \begin{frame}{Section 1}   \centering \Large Section 1 \end{frame} \begin{frame}[t]{Section 1: Contents}   \tableofcontents[currentsection,hideothersubsections] \end{frame} \subsection{Subsection 1.1} \begin{frame}{Frame 1.1.1}   A frame of subsection 1.1 \end{frame} \begin{frame}{Frame 1.1.2}   Another frame of subsection 1.1 \end{frame}   \subsection{Subsection 1.2} \begin{frame}{Frame 1.2.1}   A frame of subsection 1.2 \end{frame} \begin{frame}{Frame 1.2.2}   Another of subsection 1.2 \end{frame} \section{Section 2} \begin{frame}{Section 2}   \centering \Large Section 2 \end{frame} \begin{frame}[t]{Section 2: Contents}   \tableofcontents[currentsection,hideothersubsections] \end{frame} \subsection{Subsection 2.1} \begin{frame}{Frame 2.1.1}   A frame of subsection 2.1 \end{frame} \end{document} When we define the S-matrix, what are "in" and "out" states? I have seen the scattering matrix defined using initial ("in") and final ("out") eigenstates of the free hamiltonian, with  $$\left| \vec{p}_1 \cdots \vec{p}_n \; \text{out} \right\rangle = S^{-1} \left| \vec{p}_1 \cdots \vec{p}_n \; \text{in} \right\rangle$$  so that  $$\left\langle \vec{p}_1 \cdots \vec{p}_n \; \text{out} \mid \vec{q}_1 \cdots \vec{q}_m \; \text{in} \right\rangle = \left\langle \vec{p}_1 \cdots \vec{p}_n \; \text{in} \mid S \mid \vec{q}_1 \cdots \vec{q}_m \; \text{in} \right\rangle.$$  1) What are "in" and "out" states?   2) Are they Fock states?   3) In Schrödinger or Heisenberg or interaction representation?   4) How are they related? (I believe that I see what they handwavily represent physically, but not formally.)  My main issue is that, if "in" and "out" states are one-particle eigenstates of the free hamiltonian, i.e. if $\left| \vec{p}_1 \text{out} \right\rangle$ describes a free particle with momentum $\vec{p}_1$, and $\left| \vec{p}_1 \text{in} \right\rangle$ also describes a free particle with momentum $\vec{p}_1$, then $\left| \vec{p}_1 \text{out} \right\rangle = \left| \vec{p}_1 \text{in} \right\rangle$ ... which is false. Still, books (some at least) describe these "in" and "out" states like that.  Moreover, I have seen (e.g. in Wikipedia, but also ) that the scattering matrix is a map between two different Fock states, and I don't understand that.   5) Do states of the interacting system live in the same Fock space that asymptotic free states?   6) And if not, where do they live?  Understandable references would be appreciated. Is it possible to use `find -exec sh -c` safely? I'm trying to use find to echo 0 into some files, but apparently this only works with sh -c:  find /proc/sys/net/ipv6 -name accept_ra -exec sh -c 'echo 0 &gt; {}' \;   But using sh -c with find -exec makes me feel very uneasy because I suspect quoting problems. I fiddled a bit with it and apparently my suspicions were justified:   My test setup:  martin@dogmeat ~ % cd findtest  martin@dogmeat ~/findtest % echo one &gt; file\ with\ spaces martin@dogmeat ~/findtest % echo two &gt; file\ with\ \'single\ quotes\' martin@dogmeat ~/findtest % echo three &gt; file\ with\ \"double\ quotes\" martin@dogmeat ~/findtest % ll insgesamt 12K -rw-rw-r-- 1 martin martin 6 Sep 17 12:01 file with "double quotes" -rw-rw-r-- 1 martin martin 4 Sep 17 12:01 file with 'single quotes' -rw-rw-r-- 1 martin martin 4 Sep 17 12:01 file with spaces  Using find -exec without sh -c seems to work without problems - no quoting necessary here:  martin@dogmeat ~ % find findtest -type f -exec cat {} \; one two three  But when I'm using sh -c {} seems to require some kind of quoting:  martin@dogmeat ~ % LANG=C find findtest -type f -exec sh -c 'cat {}' \; cat: findtest/file: No such file or directory cat: with: No such file or directory cat: spaces: No such file or directory cat: findtest/file: No such file or directory cat: with: No such file or directory cat: single quotes: No such file or directory cat: findtest/file: No such file or directory cat: with: No such file or directory cat: double quotes: No such file or directory  Double quotes work as long as no file name contains double quotes:  martin@dogmeat ~ % LANG=C find findtest -type f -exec sh -c 'cat "{}"' \; one two cat: findtest/file with double: No such file or directory cat: quotes: No such file or directory  Single quotes work as long as no file name contains single quotes:  martin@dogmeat ~ % LANG=C find findtest -type f -exec sh -c "cat '{}'" \; one cat: findtest/file with single: No such file or directory cat: quotes: No such file or directory three    I haven't found a solution that works in all cases. Is there something I'm overlooking, or is using sh -c in find -exec inherently unsafe? Reference to a figure uses the section's number Dominoes and induction, or how does induction work? I've never really understood why math induction is supposed to work.  You have these 3 steps:   Prove true for base case (n=0 or 1 or whatever) Assume true for n=k.  Call this the induction hypothesis. Prove true for n=k+1, somewhere using the induction hypothesis in your proof.   In my experience the proof is usually algebraic, and you just manipulate the problem until you get the induction hypothesis to appear.  If you can do that and it works out, then you say the proof holds.  Here's one I just worked out,  Show $\displaystyle\lim_{x\to\infty} \frac{(\ln x)^n}{x} = 0$  So you go:   Use L'Hospital's rule. $\displaystyle\lim_{x\to\infty} \frac{\ln x}{x} = 0$. Since that's $\displaystyle\lim_{x\to\infty} \frac{1}{x} = 0$. Assume true for $n=k$. $\displaystyle\lim_{x\to\infty} \frac{(\ln x)^k}{x} = 0$. Prove true for $n=k+1$.  You get $\displaystyle\lim_{x\to\infty} \frac{(\ln x)^{k+1}}{x} = 0.$   Use L'Hospital again: $\displaystyle\lim_{x\to\infty} \frac{(k+1)(\ln x)^{k}}{x} = 0$.  Then you see the induction hypothesis appear, and you can say this is equal to $0$.  What I'm not comfortable with is this idea that you can just assume something to be true ($n=k$), then based on that assumption, form a proof for $n=k+1$ case.  I don't see how you can use something you've assumed to be true to prove something else to be true. When I run sudo the terminal is stuck for a few seconds and then outputs an error message. My terminal looks like this:  ubuntu@(none):~$ sudo true sudo: unable to resolve host (none)   What can I do to solve it? Cancel a vote so that the tally goes back to zero and not minus How to stop Tkinter Frame from shrinking to fit its contents? This is the code that's giving me trouble.   f = Frame(root, width=1000, bg="blue") f.pack(fill=X, expand=True)  l = Label(f, text="hi", width=10, bg="red", fg="white") l.pack()   If I comment out the lines with the Label, the Frame displays with the right width.  However, adding the Label seems to shrink the Frame down to the Label's size.  Is there a way to prevent that from happening? If $\lambda$ is an eigenvalue of $A^2$, then either $\sqrt{\lambda}$ or $-\sqrt{\lambda}$ is an eigenvalue of $A$ $A$ is an $n\times n$ matrix of complex numbers. Prove that if $\lambda$ is an eigenvalue of $A^2,$ then $\sqrt{\lambda}$ or $-\sqrt{\lambda}$ is an eigenvalue of $A.$    If $\lambda$ is an eigenvalue of $A^2,$ we have $\lambda\alpha=A^2\alpha$ for some $\alpha.$ Then how can we find a $\beta$ s.t. $\sqrt{\lambda}\beta=A\beta?$ Writing to NTFS drive in Linux I've got an external USB drive that is formatted with NTFS mounted on ~/tmp.  I can read it just fine, but cannot write to it, even as root (temp is a folder on the USB drive):  [root@Plugbox temp]# touch test touch: cannot touch `test': Permission denied [root@Plugbox temp]#   However, if I do a cat /proc/mounts, it looks like I do have NTFS read/write support:  [root@Plugbox temp]# grep /dev/sdb1 /proc/mounts /dev/sdb1 /root/tmp ntfs rw,relatime,uid=0,gid=100,umask=02,nls=utf8,errors=continue,mft_zone_multiplier=1 0 0 [root@Plugbox temp]#   Finally, if I go to the folder above temp, it looks like I should have plenty of permissions to write to the folder:  [root@Plugbox tmp]# ls -al total 61500764 ... drwxrwxr-x 1 root users           0 Apr 19  2010 temp ... [root@Plugbox tmp]#   What am I missing? $\mathcal N (A):=\mathcal P(A)\setminus\{\varnothing\}$ notation How to change the date format? Presently the date is showing as mmm dd hh:mm:ss. Is there any way that I can change it to as per my liking. For example : dd mmm, hh:mm:ss. Why is Lightroom not rendering what I see in every other JPG viewer? Should the eigenkets be weighted in $|P\rangle = \sum\limits_{r}|\xi^r\rangle$? Page 37 of Dirac's book The Principles of Quantum Mechanics, states  The condition for the eigenstates of $\xi$ to form a complete set must thus be formulated, that any ket $|P\rangle$ can be expressed as an integral plus a sum of eigenkets of $\xi$, i.e. $$|P\rangle = \int |\xi'c\rangle\; d\xi' + \sum\limits_{r}|\xi^rd\rangle$$ where the $|\xi'c\rangle$, $|\xi^rd\rangle$ are all eigenkets of $\xi$, the labels c and d being inserted to distinguish them when the eigenvalues $\xi'$ and $\xi^r$ are equal, and where the integral is taken over the whole range of eigenvalues and the sum is taken over any selection of them.  I find it inconsistent that the eigenkets under the integral are weighted by what appears to be a differential eigenvalue $d\xi'$, yet all the eigenkets under the summation are weighted by the value 1. Is this correct? Lightning Components Basics: Attributes and Expressions Trail The error :      The Packed field is either not using the lightning input component,   the checked value of the item's Packed__c attribute or the correct   type of input.   My Code:  &lt;aura:component &gt;     &lt;aura:attribute name="item" type="Camping_Item__c"                      required="true"                     default="{Name:'Tent', Price__c:100, Quantity__c:1, Packed__c:true}"                     /&gt;         &lt;p&gt; The Item is &lt;ui:outputText value ="{!v.item}"&gt;&lt;/ui:outputText&gt;&lt;/p&gt;          &lt;ui:outputText value="{!v.item.Name}"/&gt;     &lt;lightning:input type="toggle" label="Packed" name="togglevalue" value="{!v.item.Packed__c}" /&gt;     &lt;lightning:formattedNumber value="{!v.item.Price__c}" style="currency" currencyCode="USD" currencyDisplayAs="symbol"/&gt;      &lt;lightning:formattedNumber  value="{!v.item.Quantity__c}"/&gt; &lt;/aura:component&gt; "He walks as if he is drunk." Grammatically correct ? Any difference in meaning from "...as if he were drunk."? Is it grammatically correct to use an indicative verb after "as if", or "as though" for that matter?        I've heard someone say: "He walks as if he is drunk."  Would there have been any difference if he had said "He walks as if he were drunk."?   A second example might be:        It looks as if it is going to rain.   It looks as if it were going to rain. Browse for Servers does not display local instance I just installed SQL Server and SQL Server Management Studio but it doesn't show anything in servers list and I don't know how to connect to it.  This shows that I have installed SQL Server:        But in this image you can see that my Browse for Servers dialog is empty:        Network servers is empty too. change terminal title I want to make a shell alias that starts a certain program and also changes the title of the terminal to the name of the program.  How can I do that?  In case it matters, I am running the terminal on Ubuntu and connecting to a Debian server via ssh.