How can black holes have charge and gravitate?
How does gravity escape a black hole?
How to disable the "Get Windows 10" icon shown in the notification area (tray)? This icon showed up in my taskbar notification area today and I cannot seem to get rid of it:    Clicking on it displays the following screen:    So how do I disable or remove the "Get Windows 10" icon? How to find windows 10 activation Key Where can it be find?  At activation panel i can only find option to change the activation key. The current key is not presented on this screen. If I play a spell with {X} in the mana cost, and I have a card out that reduces the casting cost by 2 generic mana, what happens to the X? Does it start at -2?  For example: I have  in play. If I play  for just 1 blue mana, do we draw 2 cards? SQL-Like Inner Join on IDs in Two Layers in QGIS Using QGIS v2.6.0-Brighton.  This question is not about editing layers geographically in anyway. It is merely trying to find data from two layers as you would in an SQL Query and append an extra ID to the second layer.  I have one polyline layer each identified with two different IDs. There is a point layer also with one of these IDs, I wish to find this corresponding ID and append them as a column to the point layer.  How do I do this without finding each row individually and typing it in manually (i.e. larger scale)? I would prefer to use SQL like syntax but if there is a GUI as well that would be ideal. Happy to install official plugins. In Trailhead we have the query to get the Contacts for the Account named "SFDC Computing", with an inner query.   SELECT Name, (SELECT LastName FROM Contacts) FROM Account WHERE Name = 'SFDC Computing'   It works fine for my purposes.  "Contacts" is the name of the relationship, per Trailhead. So, I went to Object Manager and examined the Account object's "Fields and Relationships". There is nothing named "Contacts"!   In general, how do I get the name of the relationship, for use in similar SOQL queries? How can I write % into a file? How can I write % into an auxiliary file? % will not work, because LaTeX thinks that I start a comment with it (in the main file, not in the auxiliary file!), and \% will write \% into the file. How can it be accomplished?   \documentclass{article} \begin{document} \newwrite\outfile \immediate\openout\outfile=example.dat \immediate\write\outfile{%}% will not work, of course, but neither \% \immediate\closeout\outfile \end{document} How do I prevent the blank screensaver when using keyboard shortcut to lock the computer? Probability of flipping coin What is the probability of obtaining THT before HHH when a toss is tossed sequentially? Could someone solve using state diagram and law of total probability? InDesign: How to restore text-frame position/size to be managed by the master page instead of the actual page? I have some designer that moved slightly a text-frame and in order to be managed again by the master page we need to remove the page and create a new one inserting the content in it.  Is there any different way to do it?  I would like to be able to restore the "power" of positioning/size to the master page because now we need to change the master-page to position the text-frame a little bit to the right and in the case above mentioned will not be updated.  Thanks Do you say IN one of the computers or ON one of the computers? Which is right? How does ServerName and ServerAlias work? How to adopt SD card as internal storage on Samsung devices? I'm using the package braket for my physics notes, and this speeds things up a great deal but I'm constantly writing \ket{\psi} or \bra{\psi}, and because this specific pair of bra and ket appears so often, this gets repetitive and I would like a macro to speed this up.  However since the braket package works only in math mode, my attempt \newcommand{\ketp}{$\ket{\psi}}$ work when I'm writing in text mode, but when I'm writing in mathmode it breaks (unsurprisingly).  Is there any way I can get this command to work in both mathmode and textmode without having to define two different macros, one for each?    Thanks in advance for any help.  P.S. I'm certain this is a very simple question but I could find little to no explanation of this feature. Let $(X,d)$ be a metric space, and say $(x_n)$ is a Cauchy sequence such that it has a convergent subsequence $(x_{n_k})$ that converges to $x$. We show $x_n \to x$. Let $\epsilon &gt; 0$. Take $N &gt;0$ such that for all $n,m &gt; N$, we have   $$d(x_n,x_m) &lt; \frac{\epsilon}{2}.$$  By hypothesis, we can take also $K &gt;0$ such that for all $n_k &gt; K$, we have  $$ d(x_{n_k},x) &lt; \frac{\epsilon}{2}.$$  Put $M = \max \{N,K\}$. Therefore, for all $n,m,n_k &gt; M$, we have  $$ d(x_n,x) \leq d(x_n, x_{n_k}) + d( x_{n_k},x) &lt; \frac{\epsilon}{2} + \frac{\epsilon}{2} = \epsilon.$$  Hence, $x_n \to x$ as desired.  Is this a correct approach? Thank you very much in advance. Where, how and when I can acquire HM's? For the Fibonacci numbers, show for all $n$: $F_1^2+F_2^2+\dots+F_n^2=F_nF_{n+1}$ The definition of a Fibonacci number is as follows:  $$F_0=0\\F_1=1\\F_n=F_{n-1}+F_{n-2}\text{ for } n\geq 2$$   Prove the given property of the Fibonacci numbers for all n greater than or equal to 1. $$F_1^2+F_2^2+\dots+F_n^2=F_nF_{n+1}$$  I am pretty sure I should use weak induction to solve this. My professor got me used to solving it in the following format, which I would like to use because it help me map everything out...  This is what I have so far:  Base Case: Solve for $F_0$ and $F_1$ for the following function: $F_nF_{n+1}$.  Inductive Hypothesis:  What I need to show: I need to show $F_{n+1}F_{n+1+1}$ will satisfy the given property. Proof Proper:  (didn't get to it yet)  Any intro. tips and pointers? Show tabs in Chrome full screen mode? Firefox can do it, can Chrome?   Here's what I'm looking for: "This question has been asked at Stack Overflow" vs. "on Stack Overflow" How should I phrase it:     This question has been asked at Stack&nbsp;Overflow.   Or,     This question has been asked on Stack&nbsp;Overflow. Ubuntu installation is slow, why? Add source to figure caption How can I add a source to a figure? I need to add \ref, \cite or just free text. Something like that: \begin{figure} [ht]   \centering   \includegraphics[width=0.95\textwidth]{res/figure.pdf}     \caption{Caption}     \source{\ref{},\cite{} or free Text}   \label{fig:gliederung} \end{figure}  Should give me:  The source shouldn't appear in \listoffigures.