Documentation for Stack Exchange Data Explorer Schema?
Database schema documentation for the public data dump and SEDE
What kind of matter are black holes made of? Imagine a black hole originally formed from, for example, Rubidium atoms. On the other hand, one made from, for example, Helium atoms. Will it be there any difference between the two? Or perhaps once formed it all turns into the same type of matter?  Can the "composition" of the matter-energy in the black hole be inferred somehow?  Could one say that "black hole substance" is a distinct form or state of matter different from other forms or states of matter? What if table columns cannot fit on webpage? If I've 12 - 14 columns in a table to show on a page but there's not enough space to show all columns (let's say, there's only enough space to show 7 columns of the table), what is the solution for this?  I can make the page scroll horizontally but it's ugly and the last resort. Shrinking the font size of the table data only has rooms for 1  - 2 more columns at best. Find all $n \in \mathbb{N}$ such that $\phi(n) = 4294967296=2^{32}$.  I managed to find that $16106127360$, $8589934592$, $10737418240$ and $12884901888$ are solutions for the equation, but I do not know how to find all of them. If two ends were a certain "length" apart were they therefore at rest (or at least rigid) to each other? What is the icon next to Spotlight in menu bar, and how to remove it? What is this icon   in OS X menu bar and how do you remove it? Set spawn point for a specific player I made a server and me and one of my friends want to do a prank on another friend, because he stole all my enchanted diamond armor.  The Prank  I want to set a player's spawn point in a pit of lava, how would I do this without affecting anyone else's spawn point? How do I merge 2 VMware disks in to a single one? I have installed an Ubuntu server on a VMWare workstation with a space of 20GB storage as seen below:    After the installation I've attached another 40GB worth storage to the existing Ubuntu server installation (seen below):    Now I want to add this 40GB to my / (root) directory it mean's  I want that my / directory became to 60G , like it will be resize from 20G to 60G (20G + 40G), i don't know what should i do, can any body help me ?  , my df -h result shows;  root@Userver:~# df -h Filesystem      Size  Used Avail Use% Mounted on /dev/sda1        18G  900M   16G   6% / udev            990M  4.0K  990M   1% /dev tmpfs           400M  308K  399M   1% /run none            5.0M     0  5.0M   0% /run/lock none            999M     0  999M   0% /run/shm none            100M     0  100M   0% /run/user root@Userver:~#   it must be 60G !  i have no graphic mode, then i can't use Gparted tools, i'm just have ssh access ! Will Stack Overflow's engine be (someday, or ever) open sourced? I need to save/compile a few times and a bunch of weird files (like foo.tex.Ak6664) appear in my Dropbox folder each time I need to compile between two and four times before I see changes I make in the editor (TeXstudio) and each time I compile, a new .tex file is created with random letters and numbers at the end.   For example, If I create the file hello.tex and compile two to four times I'll get the file,   hello.tex.QU6664      then I make some small changes in the editor and compile two to four times I'll get the additional file,   hello.tex.Ak6664   After continuing to do this (each time compiling between two to four times before I see the changes I made), I now have many files that look like  hello.tex.QU6664, hello.tex.Ak6664, hello.tex.YX6664, hello.tex.sN6664, hello.tex.Ss6664, ...   A little bit of additional information (in case it's relevant): Everything was working fine up until a few days ago, i.e. only needed to compile once and only the file hello.tex was created. I still only get one .aux,  .synctex and .pdf files. I use TeXstudio to write and compile. I don't think it has anything to do with the bibliography (I tried removing bibliography altogether and still having the same problem).  How do I prevent these additional files from appearing and only compiling once like I used to? Has anyone had a similar problem? Book ID: Astronauts and Lab Students can create portals through space Desperate to locate and re-read exceptional book/series, but cannot remember the title. The high concept: The U.S. has just sent the first successful expedition to Mars, and it has just landed. As the astronauts make their initial exploration outside their ship, a tear in the fabric of space opens up right in front of them, and they look through to the insides of a laboratory (at a California university?) and two students who just figured out how to create arbitrary portals between two points in the Universe. The rest of the novel/series is a consequence of this breakthrough. But I can't remember the author and title(s). Surely someone reading this forum will remember it well! TIA.  (Reposted .) What does "in spades" mean? switch a theme different per user role I plan to use the member plugin by Justin Tadlock  I wish to know if how could I, on the front side, auto switch to a theme according to a role status.. for example authors would have the site presented using theme 1 while editor would have the site presenter using theme 2  I would rather have 2 different theme rather than conditionals within one theme structure  Thank you in advance How can I determine if someone's SSH key contains an empty passphrase? Some of my Linux &amp; FreeBSD systems have dozens of users. Staff will use these "ssh gateway" nodes to SSH into other internal servers.  We're concerned that some of these people use an unencrypted private SSH key (A key without a . , because if a cracker ever gained access to their account on this machine, they could steal the private key and now have access to any machine which uses this same key. For security reasons, we require all users to encrypt their private SSH keys with a passphrase.  How can I tell if a private key is not-encrypted (e.g. Does not contain a passphrase)? Is there a different method to do this on an ASCII-armored key vs. a non-ASCII-armored key?  Update:  To clarify, assume I have superuser access on the machine and I can read everybody's private keys. How often is $1+\prod_{k=1}^n p_k$ not prime? How do AD/AP boosts apply to abilities with long cast times, channels or animations? For example: I'm playing Janna in bot lane with Caitlyn. Caitlyn begins channeling Ace in the Hole to finish off an enemy. Will the AD buff from my Eye of the Storm apply extra damage to Caitlyn's ultimate if I cast at after she begins channeling? Similarly, if I see Caitlyn rev up to shoot Piltover Peacemaker, can I boost her AD after the animation begins? (If I remember correctly, Piltover Peacemaker has a quick cast time, but the spell animation is rather long, so it may be a different circumstance from the first example.)  Basically, I want to know if the AD is calculated at the start of a cast, at the end of a cast, or when the ability actually creates and object on the battlefield. How to show that the nth power of a $n \times n$ nilpotent matrix equals to zero $A^n=0$ 4 cards are drawn from a pack without replacement. What is the probability of getting all 4 from different suits?  Here's how I tried to solve:  For the first draw, we have 52 cards, and we have to pick one suit. So, probability for this is $\frac{13}{52}$.  For the second draw, only 51 cards are left. The second suit has to be selected, so there are 13 cards from that suit. The probability is $\frac{13}{51}$.  Similarly, the third and fourth draw have probabilities $\frac{13}{50}$ and $\frac{13}{49}$ respectively.  Since the draws are independent, the total probability becomes $$\frac{13}{52} \times \frac{13}{51} \times \frac{13}{50} \times \frac{13}{49}$$  But my book says the answer is $\frac{{13\choose 1} \times {13 \choose 1} \times {13\choose1} \times {13\choose1}}{52 \choose 4}$.  My answer differs by a factor of $4!$. What did I do wrong? Let $A =  \mathbb{Z}[\sqrt{-2}]= \{a+b\sqrt{-2} \ : a, b \in \mathbb{Z}\}$. Show that the only natural number $x$ for which $x+\sqrt{-2}$ is a cube in $A$ is $x=5$.   So I have to show that there exists $c,d \in \mathbb{Z}$ such that $(x+\sqrt{-2})^3= c + d \sqrt{-2}$. From the last equation, I obtain $x(x^2-6) = c \in \mathbb{Z}$ and $3x^2-2= b \in \mathbb{Z}$, and here I blocked. Could I conclude from both equations? If not, is there exists another way to proceed (hint)?  Thanks! Is it possible to open a remote terminal session on a Windows XP machine? Remote desktop is... useable, but I'd like to get a proper remote terminal window open on the Windows XP machine, like I'm able to with Linux. A quick Google points at , but it looks like it's only for Vista/Server. Passing multiple commands to gnome-terminal from a script My bash-script is not run in a terminal, but opens a terminal at runtime to ask for user input (sudo password). I would like to tell the user in this terminal what the script is trying to do. First, here is my script:  #!/bin/bash #This should install: Qt Linguist, lrelease  #for Qt Linguist dpkg-query -l qt4-dev-tools if echo $? == 0; then  check1=1 fi  #for lrelease dpkg-query -l qt4-default if echo $? == 0; then  check2=1 fi  echo $check1 echo $check2  if [ $check1 = 1 ] &amp;&amp; [ $check2 = 1 ];then  gnome-terminal -x sudo apt-get install qt4-dev-tools qt4-default fi $SHELL   This opens a terminal with this:  [sudo] password for "username":    But I would like to have:  qt4-dev-tools and qt4-default are missing. Now trying to install. [sudo] password for "username":    How do I get this when starting the terminal with gnome-terminal -x?