Plausibility of black hole in center of galaxy (apparent paradox?)
Is there a black hole in the centre of the Milky Way?
I have a Lubuntu (now 14.04) installation. Recently, I logged in to find that the Wi-Fi icon had disappeared, and there was some sort of a keyboard icon in it's place. I have restarted multiple times, but it doesn't fix it. I can't find the same applet in the panel settings, and resetting the panel didn't help. When I try to manually start nm-applet, it starts, but prints a bunch of warnings to the console:  nm-applet-Message: using fallback from indicator to GtkStatusIcon   It then starts, using ugly icons for the Wi-Fi connectivity symbol.  What do I need to do to make it start correctly? Once it starts, why isn't it using the right icons? How to factory reset without data loss and undue pain? Is the Nintendo Switch region locked? Many Nintendo devices often come with , which means if you purchase a device in one country, you won't be able to play games from another (generally).  Is the Nintendo Switch also region locked like many of its predecessors such as the Wii U and Wii? What are the differences between "to talk" and "to speak"? How can a network with only ReLU nodes output negative values? I'm trying to use an api with a feedforward neural network for time series forecasting.  For dense aggregate data it works fine, but for sparse data it sometimes forecasts negative values, even though my historical data has only positive values.   The source code is very dense, and I might be missing a line or two, but as far as I can tell, the input layers and the hidden layers are all ReLU nodes.   Assuming I am correct, how can a network with only ReLU layers lead to negative values, especially if none of the training data has negative values? Is there any way to get the number of pending chat request on omni channel? I have a requirement to get the number of pending chat request in the omni channel.  I have set the presence configuration capacity to 5 so that an agent can have only 5 chat requests. if a case is solved agent will get one of the pending chat request. But right now i can't see the number of pending request.     Lets say i have 10 pending request in the queue, but i don't have any numbers to see how many are pending in the queue.   Is there any way that can show the pending chat requests in the queue? String.Join vs. StringBuilder: which is faster? In any Pythagorean triplet at least one of them is divisible by $2$, $3$ and $5$. Show that if $x$, $y$, $z$ are integers such that $x^2 + y^2 = z^2$, then at least one of them is divisible by $2$, at least one is divisible by $3$, and at least one is divisible by $5$.  I know that $x,y,z$ are sides of a right-angled triangles. If I start putting values, then I can show, but have no clue about mathematical approach.  How do I solve it mathematically, using modular arithmetic? Separate labels in cases As much as I have tried, it doesn't seem possible to use separate labels when using a casesconstruction (from the amsmath package).  Ideally, I would like to be able to write something like  \documentclass{article} \usepackage{amsmath} \begin{document} \begin{equation} f(x)=\begin{cases}   1&amp;x\geq0\label{positive}\\   0&amp;x&lt;0\label{negative} \end{cases} \end{equation} \end{document}   and later refer to both cases at different places. What would be the best way to achieve this result? SUID-bit not working for executables within /tmp directory Printing the value of getuid() and geteuid() from an executable with SUID-bit (chmod +s) turned-on, seems to result with the original caller ID instead of the owner id if the executable is located within the /tmp directory.  When compiling the exact same code to home directory (and executing chmod +s), this seems to work as expected.  I've searched a lot and could not find any reference to such behavior.  Does anybody know why is this happening?  this source is simple as that:  #include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;sys/types.h&gt; #include &lt;unistd.h&gt;  int main(){     printf("%d\n%d\n", getuid(), geteuid());     return 0; } Following an online tutorial that uses an object named "icosahedron" from Add > Mesh > Regular Solids > Archimedean > Icosahedron. This object is not available in my version of Blender (2.74). Presenter asks me to include an add-on named "Add Mesh: Regular Solids", which again is not listed in my User Preferences dialog. What can I do about it? Why am I still getting a password prompt with ssh with public key authentication? Why does .NET use banker's rounding as default? According to the documentation, the  method uses a round-to-even algorithm which is not common for most applications. So I always end up writing a custom function to do the more natural round-half-up algorithm:  public static decimal RoundHalfUp(this decimal d, int decimals) {     if (decimals &lt; 0)     {         throw new ArgumentException("The decimals must be non-negative",              "decimals");     }      decimal multiplier = (decimal)Math.Pow(10, decimals);     decimal number = d * multiplier;      if (decimal.Truncate(number) &lt; number)     {         number += 0.5m;     }     return decimal.Round(number) / multiplier; }   Does anybody know the reason behind this framework design decision?  Is there any built-in implementation of the round-half-up algorithm into the framework? Or maybe some unmanaged Windows API?  It could be misleading for beginners that simply write decimal.Round(2.5m, 0) expecting 3 as a result but getting 2 instead. Expand the username auto-completion to everyone who can be notified UnboundLocalError on local variable when reassigned after first use The following code works as expected in both Python 2.5 and 3.0:  a, b, c = (1, 2, 3)  print(a, b, c)  def test():     print(a)     print(b)     print(c)    # (A)     #c+=1       # (B) test()   However, when I uncomment line (B), I get an UnboundLocalError: 'c' not assigned at line (A). The values of a and b are printed correctly. This has me completely baffled for two reasons:   Why is there a runtime error thrown at line (A) because of a later statement on line (B)? Why are variables a and b printed as expected, while c raises an error?   The only explanation I can come up with is that a local variable c is created by the assignment c+=1, which takes precedent over the "global" variable c even before the local variable is created. Of course, it doesn't make sense for a variable to "steal" scope before it exists.  Could someone please explain this behavior? How can I create documents in LaTeX using a calligraphic first letter for chapters? Books often have a special letter (often spanning two lines) at the beginning of chapters. How can I create this in LaTeX? Which equals operator (== vs ===) should be used in JavaScript comparisons? I'm using  to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement.  Is there a performance benefit to replacing == with ===?   Any performance improvement would be welcomed as many comparison operators exist.  If no type conversion takes place, would there be a performance gain over ==? When and where was “portfolio career“ first used? The expression  meaning:  the fact of having several part-time jobs at once, rather than one full-time job:    A portfolio career is suitable for people who want to have a variety in their work life.   (Cambridge Dictionary) Etymonline has no information about the origin of the above expression, can anyone tell me when and where it was first used? An unclear sentence in the book "Griffiths, Harris-Principles of algebraic geometry" Why can't I chown a VirtualBox shared folder?