Exception @ org.apache.myfaces.view.facelets.compiler.SAXCompiler$ViewMetadataHandler.createLocation() When JSF project is converted from Ant to Maven
What is a NullPointerException, and how do I fix it?
Compare 1st column of the 1st file and 2nd column of the 2nd file and matching I'm applying for B1/B2 visa. In DS-160, it asks for      Monthly Salary in Local Currency (if employed)   However it doesn't mention anywhere if this should be gross (before tax deductions) or net (after tax deductions, whatever is credited into my account every month).  What should I fill here? I declared random list using TikZ package and can get items randomly. But at same time I need to get all items in sequential order. How can I do it? Is it possible print \mylist items declared in noncomma variat?  \documentclass[a4paper,14pt]{extreport} \usepackage{tikz}   \def\mylist{{one}{two}{three}{four}{five}}   \pgfmathdeclarerandomlist{mynum}{\mylist} %Define the list   \begin{document} \pgfmathrandomitem{\mynum}{mynum} \pgfmathresult~\mynum\\  \pgfmathrandomitem{\mynum}{mynum} \pgfmathresult~\mynum\\  \pgfmathrandomitem{\mynum}{mynum} \pgfmathresult~\mynum\\  \pgfmathrandomitem{\mynum}{mynum} \pgfmathresult~\mynum\\  \pgfmathrandomitem{\mynum}{mynum} \pgfmathresult~\mynum\\ \end{document} How can a singularity in a black hole rotate if it's just a point? I guess nobody really knows the true nature of black holes, however, based on everything I know about black holes, there is a "singularity" at their center, which has finite mass but is infinitely small and thus infinitely dense.  So a black hole is really just a point mass that dramatically warps the space-time around it so that an event horizon is achieved.  What doesn't make sense to me is how a true mathematical "point" can rotate, or at least how it is even possible to determine if a point is rotating (or if it should even make a difference about whether or not it is rotating, for the same reason it would be impossible to tell if a perfect, featureless sphere were rotating (I know it would have higher rotational energy but lets assume you can't measure that because a true "point" can't attain rotational energy since it has no radius)).  The only conceptual solution I have to describe a rotating black hole would be to compare it to a rotating whirlpool, where the surface of the water is the fabric of space-time... but this is different because there is no "singularity" in a whirlpool that causes the water around it to rotate, whirlpools form from flow of water around a point (put into motion perhaps by some kid swirling water in a 2-liter bottle... it's due to an external cause), but the only thing that could cause rotation around a black hole would be the singularity itself, which doesn't make sense because, once again, how can we know if a true point is actually rotating?  Aside from everything I've said, here is what I am actually asking:  Why/how do some black holes rotate... what is the mechanism of their rotation (is analogous to a spinning point or a 3-d whirlpool, or something different)? From Awodey: In any category $\mathsf{C}$,  an object $0$ is initial if for any object $C$ there is a unique morphism $0 \to C$,  an object $1$ is terminal if for any object $C$ there is a unique morphism $C \to 1$.  First I was puzzled by the fact that we can do mappings from a zero set to any other set in a category $\mathsf{Sets}$. But then after I accepted it conceptually, I do not understand why there is no unique morphism to an empty set from every object in a category $\mathsf{Sets}$. Is this because we cannot map a non-empty set to an empty set (since our mapping is total) although we can map an empty set to a non-empty set?  Please, note, I am familiar with the proposition saying: Initial (terminal) objects are unique up to isomorphism. What is the proper way not to scare civilians? I know several questions were asked about the difference between "going to" and "will". Based on several answers (see, for instance, ,  and ), I understood that "will" is more spontaneous and "going to" is used with more planned actions.  So, it seems that everything is pretty fine. However, in , Kosmonaut has an answer in which he states: "Let's say that tomorrow you will walk your dog from 7 - 8 AM".  On the one hand, you probably planned to walk your dog long before and thus I should use "Let's say that tomorrow you're going to walk your dog from 7 - 8 am".   On the other hand, since I'm saying "let's say...", I'm deciding right now (thus, unplanned) that you will walk your dog. So, even though in this hypothetical situation you made a plan, I'm in a more spontaneous mood deciding right now that that's what you will do tomorrow, and, thus, I should use "will".  Which one (if any) of the above explanations is right? DataGridTextColumn.IsReadOnly seems to be faulty How do I "decompile" Java class files? What program can I use to decompile a class file? Will I actually get Java code, or is it just JVM assembly code?  On Java performance questions on this site I often see responses from people who have "decompiled" the Java class file to see how the compiler optimizes certain things. Expected prediction error - derivation Is it possible to only allow specific packages updates from a PPA Strangely low reputation How is this possible that the user with  question only has that little reputation? I've checked his site and he doesn't have a lot of downvotes or bounties. Do you capitalize both parts of a hyphenated word in a title?  "My Ex-Wife Hates Me"  or  "My Ex-wife Hates Me" What is the best way to convert seconds into (Hour:Minutes:Seconds:Milliseconds) time? I've seen sign in methods using  as an authentication provider, for example : (AWS Cloud9)        Is it possible to authenticate into Stack Exchange using this method? At the moment there's other methods such as OpenID, Google, Yahoo and Facebook, but it would be interesting to also have the GitHub authentication. Motivation behind standard deviation? How do I time a method's execution in Java? How do I get a method's execution time?   Is there a Timer utility class for things like timing how long a task takes, etc?     Most of the searches on Google return results for timers that schedule threads and tasks, which is not what I want. How to change permission external hard drive in ubuntu 12.04 I want to copy any file to my external hard drive. But always when I tried to do this I have next output:  cp: cannot create regular file /media/NameOfCard/[file]' : Read only file system  I also tried:  sudo chmod -R 775 /media/NameOfCard sudo chmod -R 777 /media/NameOfCard   But the same effect - ... Read only file system  Update:   After mount I have next output:  nazar_art@nazar-desctop:~$ mount /dev/sda1 on / type ext4 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) udev on /dev type devtmpfs (rw,mode=0755) devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755) none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880) none on /run/shm type tmpfs (rw,nosuid,nodev) /dev/sdb1 on /media/sdb1 type vfat (rw) binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev) gvfs-fuse-daemon on /home/nazar_art/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=nazar_art)   Any suggestions?   How to solve this trouble and let permission to copy and delete files to hard drive? How to randomize (shuffle) a JavaScript array? How diodes protect H-bridge DC motor driver? I don't really understand how these diodes in this circuit and similar circuits (like driving a relay circuit) protects the controller circuit from the energy stored by the inductance of the coil. I really appreciate if someone could graphically explain it. ( I mean how the the diodes block the current and etc)  the second question about this circuit is the capacitor. what happens if it isn't there?