The book was a fantasy book about a group of people working together and at the end you discover that they are all crew mates on a spaceship and the life they were living out was really a virtual reality the ship put them in while they were traveling (cryosleep) or something like that.  Does anyone remember that book?

I'm looking for a novel, of which I'm remembering mostly the end. It might be important that I've read the story in German.  Most of the story takes part in a strange, surreal world. Towards the end it is revealed that the protagonists are on a spaceship and the story took place in a  virtual reality generated by an artificial intelligence to entertain them during a long term travel. It was so real that they do not realize most of the time that they are in a virtual reality. Over time, errors accumulate and the simulations stop when people encounter too many of them.  There is a mythical figure mentioned several times (I guess it was something like "Der Wanderer", which roughly translates to traveler or wanderer).  It turns out that the whole crew is already addicted to the virtual reality, only one of them resists. All but this one get back into virtual reality.   The final scene: The one who resisted the virtual reality has a appearance of the mythical figure, which asks him what he wants to be. He answers he wants to be a plant in the desert, just feeling the sunlight and the live flowing through his body. The mythical figure tells him "that's how it plants feel", and he opens an airlock.


I've gotten into the habit of writing the following sort of code:  $q = mysqli_query($mysqli,"SELECT * FROM table WHERE a='$a', b=$b;"); while ($row = mysqli_fetch_array($q)) {     // do something     }   Where $a is a string entered by the user (gotten through $_GET) and $b is a user-entered integer.  Obviously the code I have above is vulnerable to SQL injection attacks, so my habit is to rewrite it like this:  $q = mysqli_query($mysqli,"SELECT * FROM table WHERE a='".str_replace("'","",$a)."', b=".($b+0).";");   But this of course has problems if $a needs to have apostrophes (or quotation marks when quotation marks are used to mark the string).  Recently I learned about prepared statements in mysqli and started playing around with them. I wrote the following function to make it easier to make calls without having to change much of my code:  function safequery($a,$b,$c) {     global $mysqli;     $q = mysqli_prepare($mysqli,$a);     $e = "mysqli_stmt_bind_param(\$q,\$b";     $i = 0;     while ($i < count($c)) {         $e.=",";         $e.="\$c[$i]";         $i++;         }     $e.=");";     eval($e);     mysqli_stmt_execute($q);     return $q;     }  safequery("SELECT * FROM table WHERE a=? AND b=?;","si",array("unsafestring",37));   But what is returned from this function turns out not to be a mysqli_result and thus doesn't work with the first bit of code above. After some more research, I found an alternative, but it would require a complete rethink of how I write my code. Is this necessary or is it possible to protect against MySQL injection attacks with only small changes to the first bit of code (no new lines, same output style, etc.)?  I have looked around on StackOverflow and the rest of the web but I can't find a good simple solution; all of them require the edition of at least three more lines for every call and a different way of reading each row. I'd prefer to do this procedural-y...

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I'm looking for an $n \in \Bbb N$ for which $\phi(n) = 40$ where $\phi$ is a Euler-Totient Function    I already found one, namely, $n=41$  How the calculate the $n's$?

Let $\phi(n) $ is the numbers of number that are relatively prime to n.   Then, how could we solve the equation $\phi(n) = k, k > 0?$   For example:    $\phi(n) = 8 $  I can use computer program to check all numbers that are relatively prime to $n$, but I think there must be an easier way to approach this problem.    Base on this formula: $$\prod_{i=0}^{k} p_{i}a^{a_i} $$ The only thing I can see is n must not have a prime factor > 9, otherwise $\phi(n) > 8 $. I really don't know where to start :( ? A hint would be greatly appreciated.


I was catching a Caterpie, but my game crashed after 'Gotcha!' appeared (little pokéball spinning at the top left), so I killed the app and launched it again.  Now despite the 'Gotcha!' message, I cannot see the Caterpie in the list of Pokémon I've caught recently (the last one was a Weepinbell). I'm level 12 and this is the second time that this has happened.  I was using WiFi with my Sony C4 (Android). As far as I know, my WiFi is working fine and I don't have any GPS problems.

Sometimes when attempting to capture a Pokémon, the mon will be wiggling in the ball and the app will disconnect from servers (for mobile connection reasons or whatever), and I'll be left staring at a ball containing Schrodinger's Pokémon. I'll sigh at the loss (or in the case of a 500CP Pinsir, scream in agony), and reload the game.  I thought maybe encounters in general couldn't handle disconnecting well, but sometimes immediately after a Pokémon broke free of a ball, the little icon in the upper left would appear, the game would stall for a bit, but it would recover.   Is there anything I can do to avoid this? Should I be waiting it out, instead of reloading?  (and before anyone says it, yes I have filed a bug report)


Would there be a difference in performance when i use index to get data vs column name and I am talking about doing this operation a millions of times a day in the server.  rs.getString(1) vs rs.getString("columnname");  EDIT:  JDBC version Oracle JDBC driver 10.2.0.4.0

When using JDBC, I often come across constructs like    ResultSet rs = ps.executeQuery(); while (rs.next()) {     int id = rs.getInt(1);     // Some other actions }   I asked myself (and authors of code too) why not to use labels for retrieving column values:    int id = rs.getInt("CUSTOMER_ID");   The best explanation I've heard is something concerning performance. But actually, does it make processing extremely fast? I don't believe so, though I have never performed measurements. Even if retrieving by label would be a bit slower, nevertheless, it provide better readability and flexibility, in my opinion. So could someone give me good explanation of avoiding to retrieve column values by column index instead of column label? What are pros and cons of both approaches (maybe, concerning certain DBMS)?


I've downloaded the data from Natural Earth (coastline at a scale 50 million), I've cut the coastline into my study area, I wanted to clip other vector datasets as well, for this I wanted to convert my coastline to a polygon. I've tried 2 methods: 1) Polygonize and 2) Line to Polygon (both are in processing tool), but as you can see from both of the results of this method, it gave me weird polygon shape.   Are there any other tools to create my coastline to a polygon and how?  This is my study area, which is with 2 polygon    This is the result of "Polygonize" (coordinates: user-defined coordinates)    This is the result of "Line to polygon" (WGS84, 4326)

How to eliminate seam on meridian 168W. Seam is on Russia and Antarctica?    I have done my projection in this way:


I was moving all data to another folder and made 1 mistake and run this commmand  mv * /*   all files have disappeared now. How can I find them? Or are they deleted?

It's hard to search for special characters on google, which is why I'm posting this here.  I recently ran (as root) a mv /tmp/folder/* /* when I meant to run mv /tmp/folder/* ./ Big mistake!  Things broke! A lot of files got mixed up and placed into strange places, none of the normal unix commands worked (ls, dir, cat, etc) and once you logged off, you couldn't ssh back in -- it would give you a prompt, but not accept the old passwords.  Running ls /* shows me that it performs ls on every directory in /. If I tried to draw a parallel, then mv should have simply moved (or copied?) the files to every directory in /. Instead, really weird things happened, and I was just curious what exactly was going on.  More info: The files in /tmp/folder had been transferred from a windows machine, and had been named file (#).txt, where (#) is a number up to two digits, with a space between file and the parenthesis. There were ~40 of these text files.


Is it true that $\left\{  \frac{1}{n}: n \in \mathbb{N} \right\}  \cup \left\{ 0\right\}$ is closed set? I suppose that yes, but I have no idea how can I prove it.

Prove that $ S=\{0\}\cup\left(\bigcup_{n=0}^{\infty} \{\frac{1}{n}\}\right)$ is a compact set in $\mathbb{R}$, but $\bigcup_{n=0}^{\infty} \{\frac{1}{n}\}$ is not a compact set.   (Can we use definition of compact set for this problem? )


So here it goes once again:  I am currently using this template   What I want to do is to have different linespacing and fontsize settings for the title page and the main document  The title page should be 11pt and singlelinespacing and the main document should be 12pt and onehalfspacing.   What i have tried is to use \setlinespace{1.5} for each chapter, but this doesn't work.  ------Edit------  I should also add the document class is BOOK, so in theory fontsize and linespacing for the titlepage should be 11pt and singlelinespacing  And additionally the chapters should be 12pt and onehalfspacing it that makes it clearer.

The standard titlepage is quite simple. I am looking for a very  and need help customizing my title page.  It should match the  classicthesis doctoral thesis template  Below a minimal working example:   \documentclass[12pt,a4paper,footinclude=true,twoside,headinclude=true]{scrbook} \XeTeXinputencoding iso-8859-1 \usepackage[marginparsep=8pt,left=3.5cm,right=3.5cm,top=3cm,bottom=3cm]{geometry}  \usepackage[parts,pdfspacing,dottedtoc]{classicthesis}    \frontmatter  \begin{document}     \pagestyle{scrheadings}        %this is the place to set up my cover sheet.       %*******************************************************      % Abstract     %*******************************************************    %\renewcommand{\abstractname}{Abstract}    \pdfbookmark[1]{Résumé}{Résumé}   \begingroup    \let\clearpage\relax    \let\cleardoublepage\relax    \let\cleardoublepage\relax       \chapter{Résumé}     Résumé de la thèse en français\dots      \vfill      \chapter*{Summary}   Résumé de la thèse en anglais\dots    \endgroup             \vfill     \end{document}


Let a sequence of functions $(f_n)_{n\in \mathbb{N}^*}$ such that  $f_n(x)=\left(\cos\dfrac{x}{\sqrt{n}}\right)^n$ defined on $\mathbb{R}$         Show the pointwise convergence on $\mathbb{R}$   Show that the sequence converges uniformly on $[-A,A]$ with $A>0$        Pointwise convergence  I fund that $f_n(x)\longrightarrow e^{-x^2/2}$  Uniform convergence  I must show that $||f_n(x)-e^{-x^2/2}||_{\infty}\underset{n\to +\infty}{\longrightarrow }0$  My first idea  (*to be honest I've got no overview) is to write :  $\bigg|f_n(x)-e^{-x^2/2}\bigg|$, and I tried to find a bound.  As $1-\dfrac{u^2}{2}\le\cos u\le 1-\dfrac{u^2}{2}+\dfrac{u^4}{24}\iff 1-\dfrac{x^2}{2n}\le \cos\dfrac{x}{\sqrt{n}}\le 1-\dfrac{x^2}{2n}+\dfrac{x^4}{24n^2}$  Let $g_1(x)=1-\dfrac{x^2}{2n}$ and $g_2(x)=1-\dfrac{x^2}{2n}+\dfrac{x^4}{24n^2}$ and $M_1, M_2$ such that :  For $M_1$ that is but for $M_2$ I can find a finite bound  $$|g_1(x)|<M_1\quad \text{and}\quad |g_2(x)|<M_2$$   I repeat again I haven't got any overview about how to attack this problem

Determine if $f_n(x)= \big(\cos (\frac x {\sqrt n} )\big )^n \qquad \quad$ converges pointwise or/and uniformly?   For pointwise convergence,$\forall x\in \mathbb R ,\forall \epsilon \gt0\qquad$ I should pick an $N \in \mathbb N \qquad$ such that $n\geq N \qquad$ implies $ |f_n(x)-f(x)|\lt \epsilon $  When I tried to compute $f(x)=lim_{n\to\infty}\big(\cos (\frac x {\sqrt n} )\big )^n\qquad \qquad$ ,I see(intiutively) it converges but couldn't write it properly. How should I evaluate $f(x)$ here ?


Let $R$ be a ring (not necessarily commutative). Let $u\in R^\times$, (so $u$ is a unit), and let $a\in R$ be a nilpotent element. Show that if $ua=au$ then $u+a\in R^\times$.  I have that if $a$ is nilpotent, then $1-a$ is a unit. Then, I know that this means $\exists b\in R$ such that $ (1-a)b=1$. Additionally I have that $\exists c\in R$ such that $uc=1$. Then I was thinking maybe I could do some kind of algebraic manipulation like $uc=(1-a)b$ but that seems to only lead to dead ends.  Any hints or pointers in the right direction appreciated.

If $ua = au$, where $u$ is a unit and $a$ is a nilpotent, show that $u+a$ is a unit.   I've been working on this problem for an hour that I tried to construct an element $x \in R$ such that $x(u+a) = 1 = (u+a)x$. After tried several elements and manipulated $ua = au$, I still couldn't find any clue. Can anybody give me a hint?


Am trying to deploy my application online. Every sql statements where written with PDO. I know how to do all sorts of validations and sanitization.  with the sample codes below. Am I protected against sql injection attack  connect.db  $db = new PDO ('mysql:host=localhost;dbname=mydbinfo;charset=utf8', 'root', 'ROOT123');   data.db  // select $query = $db->prepare('SELECT * FROM users where username = :username'); $query->execute( array(':username' => $_POST['username']) );   //insert  $ins = $db->prepare('insert into users(username)values(:username)'); $ins->execute( array(':username' => $_POST['username']) );

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I know there is an option to add an hdri environment texture in the shader/node editor, but is this the only option in blender 2.9? only asking because I have not found an option to add one in the "world" tab.

I have an object with an hdr for the background. What do I do in Cycles to render the background with my object?  How is this different from an ordinary render in Cycles?  The hdr is a big one, 350MB.


I want to find a number, such that the result of its SHA-256 hash is all 0. I don't know if this number exists.

Is it possible to have an output consisting purely of one character and does this change the entropy of that output? (If that's even possible to ascertain.)  As an example, the Bitcoin cryptocurrency is slowly and inadvertently compiling a list of inputs which produce outputs with successively larger numbers of trailing zeros in its blockchain. Will these ever be used to study the SHA-256 algorithm?


I have a question like this, $X \sim N(\mu,\sigma^2)$ with unknown parameters. Now, a sample of size $m$ generated from X, but filter by X < T, i.e., any number larger than T will be ignored and continue until we have $m$ samples.   How to estimate $\mu$ and $\sigma$?   I suppose we could use E-M algorithm? Since this is similar to the case of missing data.   This is what I've come up so far:   $L(\mu,\sigma^2;x_1,..,x_m,x_{m+1},..x_n) = \prod_i^m f(x_i) \prod_{m+1}^n (1-\Phi(T))$ $Log L(\mu,\sigma^2;x_1,..x_m,x_{m+1},..x_n) = \sum_i^m log(f(x_i)) + \sum_{m+1}^n log(1-\Phi(T))$  Then how to take derivative of the Log likelihood with respect to $\mu$ and $\sigma^2$, also $n$ is unknown, need to be estimated here?

My dependent variable shown below doesn't fit any stock distribution that I know of.  Linear regression produces somewhat non-normal, right-skewed residuals that relate to predicted Y in an odd way (2nd plot).  Any suggestions for transformations or other ways to obtain most valid results and best predictive accuracy?  If possible I'd like to avoid clumsy categorizing into, say, 5 values (e.g., 0, lo%, med%, hi%, 1).


I'm sure about the 1st sentence, since I always see it at the opening credits of almost every film (a somebody's film).  But I'm not sure about the 2nd one, just it doesn't even look correct if I write it "A John's brother".  So, my question is as follows:  Is there any rule regulating usage of article before names like in my examples?  Thank you in advance!

I can’t for the life of me figure out where to use a and where to use the — and where there is no article at all. Is there a simple rule of thumb to memorize?   The standard rule you always hear:     “If a person knows which item you are talking about then use "the"   . . . doesn’t clear things up for me, as I have no idea whether or not they know.


I did a sudo apt-get remove ruby* and then I saw that some grub packages were being removed too so I went to installed back those packages which log showed to have removed  I set grub to work on my /sda (in general, not any number) when was installing back.  Should all be ok or should I fear for my system and plan installing/reconfiguring more of grub.  And, why did this happpen?

Last night I was trying to burn CDs. Being annoyed with k3b and choosing to use brasero instead, I went to remove k3b.  I typed in:  sudo apt-get remove k3b   I hit tab twice and saw that I had both k3b and k3b-data on my system. Assuming that I wouldn't need k3b-data on my system without k3b, I wanted to remove it as well so I typed in:  sudo apt-get remove k3b*   Unfortunately I hit Y to confirm without looking. It uninstalled a whole lot more than k3b and k3b-data. It uninstalled packages which did not fit my k3b* regex. For example: transmission and network-manager.  I'm fairly certain that I didn't have a space between k3b and * but I don't know why else it would remove all that it did. Is there something about apt-get that I'm misunderstanding?


My minecraft always crashes when I hit the play it loads but then it comes back with a crash report and I can't even see the minecraft home screen. How can I fix this? My parents think someone has hacked into my minecraft.  Crash Report  ---- Minecraft Crash Report ---- // Don't be sad, have a hug! <3              <<<< Whats this mean?  Time: 12/19/16 4:32 PM Description: Initializing game  org.lwjgl.LWJGLException: Pixel format not accelerated     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at beq.ap(SourceFile:597)     at beq.an(SourceFile:433)     at beq.a(SourceFile:380)     at net.minecraft.client.main.Main.main(SourceFile:124)   A detailed walkthrough of the error, its code path and all known details is as follows: ---------------------------------------------------------------------------------------  -- Head -- Thread: Client thread Stacktrace:     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at beq.ap(SourceFile:597)     at beq.an(SourceFile:433)  -- Initialization -- Details: Stacktrace:     at beq.a(SourceFile:380)     at net.minecraft.client.main.Main.main(SourceFile:124)  -- System Details -- Details:     Minecraft Version: 1.11     Operating System: Windows 7 (x86) version 6.1     Java Version: 1.8.0_25, Oracle Corporation     Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation     Memory: 75557872 bytes (72 MB) / 148910080 bytes (142 MB) up to 523501568 bytes (499 MB)     JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M     IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0     Launched Version: 1.11     LWJGL: 2.9.4     OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.     GL Caps:      Using VBOs: Yes     Is Modded: Probably not. Jar signature remains and client brand is untouched.     Type: Client (map_client.txt)     Resource Packs:      Current Language: ~~ERROR~~ NullPointerException: null     Profiler Position: N/A (disabled)     CPU: <unknown>

Similar to  on the bugs in Minecraft, I would like a complete list of what error codes exist in Minecraft and how they occur, as well as how they can be resolved.


I'm designing my first drupal theme and I'm not very well experienced in this kind of stuffs. I tried to add some jQuery to my design so I saved this code into a .js file and add it to my theme.info file:  $(document).ready( function() {     $("button").click(function() {         $("button").hide();     }; };   It should work properly but it didn't. After some searching, find out for avoiding conflicts I should use drupal's function instead of $(document).ready so I did:  (function ($) {             $("button").click(function(){                 $("button").hide();     }); })(jQuery);   but it doesn't work out. And again, by googling I find out something named behaviors. Actually I can't understand what is it but after using examples as a pattern an overwriting my code into it, my issue fixed:  (function ($) {     Drupal.behaviors.exampleModule = {         attach: function (context, settings) {             $("button").click(function(){                 $("#navigation").hide();     });         }     } })(jQuery);   So my question is: What is drupal behaviors?  I read some articles about it but couldn't understand it well.  Also some examples will appreciated.

I read about Drupal behaviors today, and I tried writing the following code.  (function ($) {    Drupal.behaviors.mymodule = {     attach: function (context, settings) {       $('#mymodule_id', context).change(function () {         alert('Handler for .change() called.');       });     }   };  }(jQuery));    Is Drupal.behaviors.mymodule the namespace? What are the context and settings parameters passed to the Drupal behavior? Is this the equivalent of document.ready()?   Can I attach any number of functions?  Can I define JavaScript functions which will be called somewhere?


I am making a hide & seek scoreboard countdown for a friend of mine's hide and seek game. I want to ask how do you use /execute to test if an entity’s scoreboard is equal to 0?  I have an armour stand with a score that goes down by 1 every second, so I wanted to make it so that it runs a command when the score equals 0.

I was trying to use the command /scoreboard players test @p Objective 1 in 1.14.2, but it seems like 1.14 has changed every command in Minecraft. I need help finding a replacement for this command.  I want to explain why this question is unique. For the first, the example of a possible duplicate of my question is not the same because I asked about scoreboard commands and not to check blocks, and I want to quote this comment:     MBraedley: Same answer does not make for the same question, so I would   not close this question as dupe (at least to the proposed target).   Even though I don't think its the exact same answer, because the only same thing about the answer was /execute if and the continued answer was score player objective matches 1, and my point with this answer was that you can't use /scoreboard players test objective 1\ anymore, and if you want to test a score, you have to use the answer I provided, or at least if you want an exact replacement for the command I mentioned in my question.  Since Minecraft 1.13 & 1.14 they have reworked many or maybe nearly all the commands in Minecraft, and for me, and for a lot of people, this has been very confusing, and I have had to learn much of the commands over again, or adjusting my commands.


Seems this should be simple, but I'm unable to find the combination of GPO options to default the home page so that the user can't change it, but to let them add any of their own home pages to the list of tabs?  Thanks.

I need to set the default home page for the entire domain via GPO. Where is the IE Home Page Policy located?


I have rewritten this question to be more straightforward. I have a SQL query:  SELECT CAST(CASE WHEN DTH.DoubleBookedFlag = 1 THEN DTH.ActivityDate END AS VARCHAR(MAX)) AS DoubleBookedHours FROM DailyTaskHours DTH WHERE DTH.DoubleBookedFlag = 1   Here is the result:    Instead of returning as multiple rows, I would like whatever is returned to be one long concatenated string in a single VARCHAR field seperate by a character like |.  How can I achieve this?

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


When validating forms with javascript and php, why do we need to include the same validation rules (ie correct format, checking fields are filled in, values within bounds) on both the server and browser? I understand that javascript can be turned off, so why not just have everything on the server and save checking it twice?

Which is better to do client side or server side validation?  In our situation we are using    jQuery and MVC.   JSON data to pass between our View and Controller.     A lot of the validation I do is validating data as users enter it. For example I use the the keypress event to prevent letters in a text box, set a max number of characters and that a number is with in a range.   I guess the better question would be, Are there any benefits to doing server side validation over client side?    Awesome answers everyone. The website that we have is password protected and for a small user base(<50). If they are not running JavaScript we will send ninjas. But if we were designing a site for everyone one I'd agree to do validation on both sides.


Find all $p,q$ primes such that $pq\mid 2^p+2^q$.   $Case 1(p=q=2)$ Then it satisfies condition of problem.  $Case 2(p=2,q\neq2)$. Then by Fermat's little theorem, $q\mid6\implies q=3$. It means $6\mid 12$ which satisfies condition of problem.  $Case 3(p,q\neq2)$. By Fermat's little theorem, $2^{p-1}\equiv -1(mod q)$ and $2^{q-1}\equiv -1(mod p)$. It means $2^{p+q-2}\equiv -1(mod pq)$. Now I don't know how to continue. Anyone can continue this?

Find all pairs of primes $p,q$ such that $pq \mid 2^p +2^q$.  My attempt  : When either one of them is $2$ then easy case checking gives me set of solutions. But what happens when neither of them is $2$?


A process called "System" on my windows10 laptop is using all the memory. I can't play any games because of this. Chrome too freezes. It's almost impossible to use any program.  I've 8GB Ram. The "system" process is using 70-80% of it.

A few days ago I updated my PC to Windows 10. However, after some use my PC started to slow down until it was impossible to use – it was due to high memory usage. After a restart, everything came back to normal (total usage around 25% of 8GB of RAM). However, during a few hours of usage the memory builds up again to 70%, and if not restarted it further goes to 100%, and later on even freezes. Task manager does not help very much as it does not show all the processes (added screenshots below). Also tried RAMMap but it gives an error: "error refreshing database". I tried Googling this question, yet without much success.  I do not know much about PCs, but maybe some of you know this issue, or could help to find out what is using my RAM.


Bernoulli's principle states that air molecules moving with high velocity create an area of low pressure which in turn causes an object to fly, but how does high velocity cause low pressure?

So, if we have a large pipe which is constricted in the middle, the fluid in the middle section  will move faster. Why is it so? What dictates that liquid that an X amount of it must pass on the other side regardless of the size of the encasement?  The only reason I could think about is because that the initial pressure which causes the movement somehow is being transferred to a smaller area, but that makes no sense.


it is possible to move some partition(entire) before another?  I need to resize my root partition, but the free space is too far away.(I want to move the free space near the root part.)  Can this be done somehow, or have I to backup the data and start from begining?

I am in a frustrating situation - no matter how I try, gparted won't let me assign the empty space to the first partition:    The middle partition is blocking me from expanding /dev/sda1. I need to move partition /dev/sda2 to the end of the drive, like so (fabricated image):    Then I will be able to expand first partition:    How to do that? I assume data from /dev/sda2 must be physically copied to end of the drive.


Can you have a look to the following questions? They have exactly the same title.          Of course I can edit the title of each question to differentiate and make it better clarificative; but maybe it would be more useful to implement a feature suggesting people to write a better title in case of exactly identical title with other questions.  What's your opinion on that?

I recently saw a question titled "" (10k+ users only). I thought, "surely someone has asked this question before", and began looking for a duplicate.  is a question with the exact same title, just with a little different punctuation and casing. It was "Jquery vs Javascript" and "jQuery vs. Javascript?". The only difference being the ., ?, and the casing.  Since we now , I propose that when checking for questions with duplicate names, certain punctuation be striped out to prevent the duplicate from occurring in the first place.  As pointed out in the comments, if isn't already, white-space and non-printable characters may want to be removed for duplicate detection as well.


Does the bi prefix mean that it is every second month or twice a month?

What do lengths of time with the "bi" prefix mean"? I have understood bicentennial as once every two hundred years, but biannual as meaning twice a year. Do biweekly and bimonthly mean twice a week or month, or once every two weeks or months?  If this prefix is not used consistently, is there any rationale as to why it isn't?


If someone were to add another, anonymous membership, they could ask an obscure question (in the guise of the anonymous member) to which they had already researched a brilliant answer, thus enhancing the reputation of their prime account.  And they could vote up their own questions, comments and answers.  I have noticed some rather questionable situations and wondered if SE is policed sufficiently that this kind of thing would be noticed and prevented.

A high-reputation, highly-active user has already been dinged once for a sockpuppet, and I just dinged him again. He probably has another sockpuppet as well.   What are the guidelines for handling users who game the system in this fashion? Specifically,   How can I be sure I'm looking at a sockpuppet? When should sockpuppets be considered a problem? How should moderators handle problematic sockpuppets once they've been identified? I was suspended for sockpuppetting and feel this is unfair


sudo apt-get update is not working, what should I do?

I have unistalled and reinstalled the Ubuntu Software Center as per info I found in a similar thread and I got the same response about line 91 or something like that.  I just tried to upload a screen shot but since I'm new it won't allow me to.  I also can not figure out how to cut and paste anything so I have to hand type what the error screen says, both when I attempt to open the software center and nothing happens, when I try to enter commands into the terminal to uninstall, reinstall, whatever I get the same following:  COULD NOT INTITIALIZE THE PACKAGE INFORMATION An unresolvable problem occured while initializing the package information Please report t:his bug against the 'update-manager' package and include the following error message: 'E: Malformed line 91 in source list/etc/apt/sources.list (dist parse)  E: The list of sources could not be read.,  E: The package list of status file could not be parsed or opened.   How do I report bugs?  What can be done about this.  I have searched and everything everyone says to do leads me back to the same line error message.  So, I don't know how to get to line 91 in the source list; to tell you what it says. Sorry, I'm really new to this. That is what I need is to find out how to get there and fix what it says. I would really like to NOT have to re partition my hard drive and start from scratch, so I'm really looking forward to getting this problem solved. I need to be able to install new software.


I have a very very slow computer, but would like to animate 3D. I'm aware we can render via the command line. but I don't know how. I want to render the entire animation of my Tutorial.blend file in the background.

It seems that Cycles is mainly built in the form of Python scripts (as far as I can tell). Is it still possible to use Cycles to render a .blend file from the command line?


So I was on my pc last night with no issues and I woke up this morning to this screen:    I’ve never had this happen before but apparently my SSD has been corrupted/will be soon? I had windows on it so I literally cannot start my computer. It just loops me to the bios and then back to the error screen. I tried booting my pc through a flash drive with windows but even then I get looped, so I have to completely remove the SSD from my computer. After I did that, it takes me to the windows installation but I cannot upgrade the windows, so I have to go with custom installation but when I try installing windows on my HDD I get this error message:    All the solutions online tell me to completely wipe my HDD, which is definitely not an option. It feels like my only choice is to buy a new SSD and load windows on it and hope that I can somehow recover my old SSD files somehow right? Or am I missing something?

What steps can I take to try to recover lost or inaccessible data from any storage device?  Answers:   This applies to any computer storage device, e.g. internal/external hard drives, USB sticks, flash memory. The most important thing is to STOP using it, any type of I/O can ruin your chances of a recovery.     We have separate questions covering common problems with USB flash drives in greater detail:


I want to show excerpt and cap it at 20 words

Possible Duplicate:          I have a question after reading this post (). I like this function(Search Term Without Plugin) very much but the character length is too long. What php code should i add to make the excerpt shorter? Would appreciate if someone can suggest it. Thank you!


I'm quite out of my element trying to do some matrix calculus.  I would like to know what the derivative of $z^{T}y$ w.r.t $z$ is, where z, y are n length vectors.  Can anyone suggest good resources as well?  Thank you!

In Andrew Ng's machine learning course, he uses this formula:  $\nabla_A tr(ABA^TC) = CAB + C^TAB^T$  and he does a quick proof which is shown below:  $\nabla_A tr(ABA^TC) \\ = \nabla_A tr(f(A)A^TC) \\ = \nabla_{\circ} tr(f(\circ)A^TC) + \nabla_{\circ}tr(f(A)\circ^T C)\\ =(A^TC)^Tf'(\circ) + (\nabla_{\circ^T}tr(f(A)\circ^T C)^T \\  = C^TAB^T + (\nabla_{\circ^T}tr(\circ^T)Cf(A))^T \\ =C^TAB^T + ((Cf(A))^T)^T \\ = C^TAB^T + CAB$  The proof seems very dense without any comments and I'm having trouble understanding it. What exactly happened from second to third equality?


I would like to the fastest way to find $\dim(V \cap W^\bot)$ where $V$ and $W$ are two subspaces of $\Re^4$. $V$ is defined as the span of three vectors and $W$ the span of one vector.For example as in here - $$ V = \left\langle\begin{pmatrix}2\\2\\2\\1\end{pmatrix}, \begin{pmatrix}5\\4\\1\\1\end{pmatrix}, \begin{pmatrix}2\\1\\1\\0\end{pmatrix}\right\rangle,\quad W = \left\langle\begin{pmatrix}1\\-3\\2\\1\end{pmatrix}\right\rangle $$

We're given: $$ V = Span\left\{ \begin{bmatrix} 2 \\ 2 \\ 2 \\ 1 \end{bmatrix}, \ \begin{bmatrix} 2 \\ 1 \\ 1 \\ 0 \end{bmatrix}, \ \begin{bmatrix} 5 \\ 4 \\ 1 \\ 1 \end{bmatrix}  \right\} \ \ \   \mathrm{and} \ \ \ W = Span \left\{\begin{bmatrix}1\\-3\\2\\1 \end{bmatrix} \right\} $$  and we're asked to find $\mathrm{dim}(V\cap W^{\bot})$  Here's my approach. First, by inspecting the basis of $W$, I managed to construct a basis for $W^{\bot}$, which is the following: $$W^{\bot} = Span \left\{\begin{bmatrix} 3 \\ 1 \\ 0 \\ 0 \end{bmatrix}, \begin{bmatrix} -2 \\ 0 \\ 1 \\ 0 \end{bmatrix} \begin{bmatrix} -1 \\ 0 \\ 0 \\ 1 \end{bmatrix}\right\}$$ Then, for each vector $\textbf{w}$ in the basis of $W^{\bot}$, I tried to see if the system $A\textbf{x}=\textbf{w}$ was compatible or not. In this case, I found out that the system was only compatible with two of the vectors in $W^{\bot}$, thus indicating me that $\mathrm{dim}(V \cap W^{\bot} ) = 2$ (which is correct).  What I do not get, however, is  that since the dimension of the intersection is $2$, why aren't two of the vectors in the basis of $V$ orthogonal to the vector which spans $W$ (that was my initial approach, i.e try to see which vectors of the basis of $V$ are orthogonal to the vector that spans $W$).  Also, I was wondering if there was a simpler/quicker way of doing this.


In text studio, when you start typing \( it automatically fills in to \(\) with the cursor in the middle. As I try to type let's say a greek letter such as "\gamma", the editor automatically uses the backslash from \), meaning that I end with \(\gamma) instead of \(\gamma\) of course.   Is there a way for the editor to stop trying to auto-complete that aspect as it is always doing it wrong?

I want to disable auto-complete for braces in TeXstudio. In its simplest form, when I type {  I do not want it to automatically add a }.  When it does this, many times I end up deleting the brace, which is a hassle.  Also, when I hit Ctrl+I to get into italics mode I don't want it to auto-complete the ending brace either.  I have gone to Options -> Configure TeXstudio... -> Completion -> Show Advanced Options and disabled everything.  But it still auto-completes them.  In case it matters the version I have is TeXstudio 2.8.4.


Is that explanation actually correct? Can we take sign conventions according to our preference which satisfies equation and also predict direction?

If we write out Maxwell's equations with magnetic charges, we get $$ \begin{align} \nabla \cdot \mathbf{E} &= 4 \pi \rho_e \tag{1}\\ \nabla \cdot \mathbf{B} &= 4 \pi \rho_m \tag{2}\\ -\nabla \times \mathbf{E} &= \frac{\partial \mathbf{B}}{\partial t} + 4 \pi \mathbf{J}_m \tag{3}\label{Eq:Faraday}\\ \nabla \times \mathbf{B} &= \frac{\partial \mathbf{E}}{\partial t} + 4 \pi \mathbf{J}_e \tag{4}\label{Eq:Ampere} \end{align} $$ In particular, Faraday's law \eqref{Eq:Faraday} contains a minus sign that Ampere's law \eqref{Eq:Ampere} does not. This always struck me as odd because it's often said the fields are dual to each other (i.e. you can replace E with B and "get the same result"), but that requires a bit of mental recalibration to accommodate that minus. So I'm curious what the origin of that negative is and what it means. Are there any intuitive explanations for how to think about it?


I right click and into properties I allow the permision to run as a programe. But still cannot run it. It is still opening in text document file

Whenever I open a .sh file, it opens it in gedit instead of the terminal. I can't find any option similar to Right Click → Open With → Other Application... → Terminal.  How do I open this file in the terminal?


I am working on a dictionary that maps names to votes received. I need associate the name with the most votes, assigning it to the variable win.   So far:  vote = {}  for key in vote:     vote(max(key)) = win   How do I associate win to the name, because I believe my error now is that I am associating it to the highest number.  Thank you for your help.

I have a dictionary: keys are strings, values are integers.  Example:   stats = {'a':1000, 'b':3000, 'c': 100}   I'd like to get 'b' as an answer, since it's the key with a higher value.  I did the following, using an intermediate list with reversed key-value tuples:  inverse = [(value, key) for key, value in stats.items()] print max(inverse)[1]   Is that one the better (or even more elegant) approach?


Let $y=x^2$ and $y=t^4$ $$\frac{\mathrm{d}y}{\mathrm{d}x}=2x$$ $$\frac{\mathrm{d}y}{\mathrm{d}t}=4t^3$$ Now, $\frac{\mathrm{d}}{\mathrm{d}t}\left(\frac{\mathrm{d}y}{\mathrm{d}x}\right)=\frac{\mathrm{d}}{\mathrm{d}t}\left(2x\right)=\frac{\mathrm{d}}{\mathrm{d}t}\left(2t^2\right)=4t$ $\frac{\mathrm{d}}{\mathrm{d}x}\left(\frac{\mathrm{d}y}{\mathrm{d}t}\right)=\frac{\mathrm{d}}{\mathrm{d}x}\left(4t^3\right)=\frac{\mathrm{d}}{\mathrm{d}x}\left(4x^{\frac{3}{2}}\right)=6t$ Why am I getting $\frac{\mathrm{d}}{\mathrm{d}t}\left(\frac{\mathrm{d}y}{\mathrm{d}x}\right)$ is not equal to $\frac{\mathrm{d}}{\mathrm{d}x}\left(\frac{\mathrm{d}y}{\mathrm{d}t}\right)$? Isn't it a law of calculus?

I understand that for the parametric equations  $$\begin{align*}x&=f(t)\\   y&=g(t)\end{align*}$$  If $F(x)$ is the function with parameter removed then $\displaystyle F'(x) = \frac{\text{d}y}{\text{d}t}\big/\frac{\text{d}x}{\text{d}t}$  But the procedure for taking the second derivative is just described as " replace $y$ with dy/dx " to get   $$\frac{\text{d}^2y}{\text{d}x^2}=\frac{\text{d}}{\text{d}x}\left(\frac{\text{d}y}{\text{d}x}\right)=\frac{\left[\frac{\text{d}}{\text{d}t}\left(\frac{\text{d}y}{\text{d}t}\right)\right]}{\left(\frac{\text{d}x}{\text{d}t}\right)}$$  I don't understand the justification for this step. Not at all.   But that's all my book says on the matter then it launches in to plugging things in to this formula, and it seems to work well enough, but I don't know why.  I often find answers about question on differentials are beyond my level, I'd really like to get this, it'd mean a lot to me if someone could break it down.


I want to make a subtitle for a chapter, having \Large as the chapter's title font size; so I'd write it as  \documentclass{book} \begin{document} \tableofcontents \chapter{Title \\ {\large Subtitle}} \end{document}   This would make the subtitle's font size look good where the title is, but look horrific in the toc. So I'm asking, is there any kind of command or workaround so that will decrease subtitle's font size by one size, in both occasions? From \Large to \large in the chapter and from \normalsize to \small in the toc.   Thanks in advance

I'd like to do this for some of my sections but not all. I'd also like to maintain the current spacing; for example, if the vspacing is 1cm from section title to body text (at 100% zoom), then I'd like it to be 1cm from the subtitle to body text.  Thanks.


When is the appropriate time to use "a" vs "an"?  For example, "I have a array of..." vs "I have an array of..."  I may be mistaken but I would typically use an in this case.   Firstly, am I correct to use an in this case? Secondly, is there a rule of thumb or grammatical rule that defines the appropriate usage? Lastly, If there is a grammatical rule, what is a recognized resource to its definition?

In the following example, is it appropriate to use a or an as the indefinite article, and why?     He ate __ green apple.   I know that in the case of just "apple", it would be "an apple," but I've heard conflicting answers for "green apple," where the noun is separated from the article by an adjective.  Also, which is more appropriate in this case:     He ate  __ enormous Pop-Tart.


I have the following code that dynamically creates an environment over a page. The ultimate goal is to create a "walk-through wizard" for users.   This code adds an overlay over my page, and then a container with a next and previous button in it.  Then, using Ajax, I populate the container for each step (triggered by the Next/Prev buttons).  In order to achieve some unique styles and apply unique functions to each step, I add a class to the container and to the buttons for each step. For example, The first step, the container has the class step1, as do the buttons, second step has the class step2 applied to the container and buttons and so on.  What I'm finding is that I can't apply functions to buttons based on the class that changes using jQuery.  For example, here is my code that creates the environment, calls the files for each step and adds all the classes:  jQuery(function ($) {   $('body').attr('onboarding_step', 'step1');   $('body.wp-customizer').addClass('skizzar_onboarding');   $('

').insertBefore('body.wp-customizer');  // first step   $('#so_overlay').html('

');   $('#onboarding_steps_container').html('

<button id="prev" class="step1"> PREV</button><button id="next" class="step1">NEXT </button>
');  // here's the steps var steps = [   "wp-content/plugins/skizzar-onboarding/ajax/step1.php",   "wp-content/plugins/skizzar-onboarding/ajax/step2.php",   "wp-content/plugins/skizzar-onboarding/ajax/step3.php",   "wp-content/plugins/skizzar-onboarding/ajax/step4.php",   "wp-content/plugins/skizzar-onboarding/ajax/step5.php", ]; counter = 0; $('.onboarding_steps').load(steps[counter]);  $('#next').click(function () {   counter = (counter + 1) % steps.length;    $('.onboarding_steps').load(steps[counter]);    $('#onboarding_steps_container, .button_holder button, #so_overlay').attr('class', 'step' + (counter + 1));    $('body').attr('onboarding_step', 'step' + (counter + 1));  });  $('#prev').click(function () {   counter = (counter - 1) % steps.length;    $('.onboarding_steps').load(steps[counter]);    $('#onboarding_steps_container, .button_holder button, #so_overlay').attr('class', 'step' + (counter + 1));    $('body').attr('onboarding_step', 'step' + (counter + 1));  });  });   Now if I were to add the follownig code to send a message to the console when the button with class .step2 is pressed:  $('.step2 #next').click(function () {     console.log('step 2 pressed'); });   Nothing happens. I think this is because I am changing the class via jQuery, however, I have no idea how to get around this problem.  Here is a jsfiddle showing my issue:   (Obviously I can't load the files using jsfiddle, but if you inspect the elements, you will see that second time you press NEXT (which has the class step2 it should send an alert, but it does nothing)

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Lately, I am holding a lot of vconfs on Google Hangouts. I'm using a headphone set but the internal mic is capturing the input sound. Apparently, if I move a bit away from my iMac or if I speak softer, the system increases (adjusts) that volume automatically. That is all very nice except that then, I start hearing my own echo on the other end! (I mean, transmitted back to me from my vconf partner amplified and delayed).  Does anybody know of a way to prevent that (automatic) behaviour? For instance, to limit the volume instead of just setting it up.

I've found this issue and various discussions online about this, but no obvious "just do this", so I'm wandering over here from ServerFault to ask this.  Is there a way to disable or hard-set the input level on a mic?  In the Sound preferences on the Input tab if I click on the device and set a level and then start talking it picks up the sound and then start to auto-adjust the mic input level.  This causes issues when talking with someone on Lync/Skype/etc because one minute the sound is fine and then if you raise your voice for a second and then lower it back down (or shift around in your chair) the auto-adjust causes the other party to think your whispering or yelling.  I'd like to be able to disable the auto-adjust if possible.  Yes/No?   NOTE: The issue is similar this one:  but rather on the input side and not the output side for me.


I am watching a video of one of the Apostles of the Mormon Church, Elder Holland, which is entitled:     "An High Priest of Good Things to Come"   The video contains this line:     "Speaking of Jesus’ “more excellent ministry” and why He is “the mediator of a better covenant” filled with “better promises,” this author—presumably the Apostle Paul—tells us that through His mediation and Atonement, Christ became “an high priest of good things to come.”"   Can anyone tell me why he is using the phrase "an high priest" instead of the more conventional "a high priest"? Although the text is a translation from the original language, the address was a mass address intended for members of the general laity, rather than purely biblical scholars. Thus it seems that the a is likely to have been deliberately left in, in order to evoke some sense of the word an to an English speaking audience which is not present in the word a, and therefore retain more of the intentionality of the original text...  Could anyone offer an explanation as to what an is doing in this text, in an English Language sense, which a would not have been appropriate for, or would in some way have been detrimental to the message of (or could be considered to be detrimental to the message of)?  Statement of Non-Duplicate Status  I'm after a specific answer for this passage, not just general rules for an and a. I would also like something a little more than "it sounds nicer", which isn't really an answer; preferably something which broaches any subtle differences in meaning between the two words, and the manner in which the sense of passage would be different if it were to utilise a instead of an.  (Link to video for reference: )

A basic grammar rule is to use an instead of a before a vowel sound. Given that historic is not pronounced with a silent h, I use “a historic”. Is this correct? What about heroic? Should be “It was a heroic act” or “It was an heroic act”?  I remember reading somewhere that the h is sometimes silent, in which case it’s an, and when the h is pronounced, it’s a. But then I also remember reading that it depends on which syllable is stressed. And I also think I read somewhere that it might differ between British and American English.  Personally, I pronounce the h, and believe that a is correct. I find that it sounds incorrect to use an and pronounce heroic without the h.  So how do I know when to use a and when to use an with a word beginning with the letter h? Are both acceptable or is there one that is correct?


I have been using Stack Overflow for a month now. There are "yes" and "no" options for positive and negative response, respectively. I was wondering, how does this feedback affect my reputation?

Anonymous and unregistered users with < 15 reputation (the amount required to earn the upvote privilege) will now see       feedback   on every post in the area that a logged in user would see "add comment":    When the post area is moused over, the area expands to:     Was this post useful to you? [Yes] [No]     once clicked it will say     sending feedback...   and eventually     Thank you for your feedback.   The goal is to offer the 90% of our traffic that is anonymous users a way to provide more meaningful feedback on posts rather than passively incrementing a view counter.  This click data is currently being evaluated to see what we can do with it. Ideas welcome!


For example, I'd like a 3D image of screenshots, similar to this one:  (from WojoMarket's website) Are there any ready made software in order to do

How do I create this type of effect with an image? I'm wondering how to get the thick edges and the tilted look. Is there an online tool that will convert a flat image to look like this?


find all $z$ in polar form satisfying the following  $z^4 = -1 +i\sqrt{3}$  What I did was the following.  Let $z = r(\cos\phi\ +\ i\sin\phi)$  Therefore $z^4 = 2(\cos\frac{\pi}{3} + i\sin(\frac{\pi}{3}))= r^4(\cos4\phi\ +\ i\sin4\phi)$  Therefore by comparism, $r = 2^{1/4}, \ \phi = \frac{\pi}{12} + \frac{n\pi}{2}$ where $n \in \{0,1,-1,2\}$  But my answer seemed to be wrong and I was hoping if you guys can point out my mistake.  Any help or insight is deeply appreciated.

How do you get the roots of the equation in algebraic form? I have no idea after changing to a trigonometric form. The angle was not simple.  $z^4- \sqrt3 i+1=0$


If time is the 4th dimension, I can think of 2 ways to describe the flow of time. Either matter is moving forwards along the t axis, or space is. In the former, each particle has its own time and "exists" only once, while in the latter, everything Big Bang to Heat Death already exists, and space is just going through it, like frames in a movie. Are  any of the 2 correct? Do we even know? And, if neither are, how does it actually work?

This is an attempt to gather together the various questions about time that have been asked on this site and provide a single set of hopefully authoritative answers. Specifically we attempt to address issues such as:   What do physicists mean by time? How does time flow? Why is there an arrow of time?


before I begin I would like to say that I am new to blender so please be patient with my lack of knowledge.  I want to make a donut to learn the basics of Blender,so far is good,but when it comes to parenting I don't know if either my model is so badly made or maybe there are some values that are not the right.  One object moves faster then the other and.I would apreciate any advice. Thank you for your time

I go into edit mode for an object, select vertex mode, select one of the squares, then pull the arrow it moves just the square like it is suppose to. If I resize it then go into edit mode it no longer does this.  When I select vertex select a square, then go to move that square everything moves now, not just the vertex. Why?   I have already reset everything back to default settings and it is still doing this. It wasn't doing this yesterday, but today it is.


What could be the reason for this error :  sed couldn't flush stdout no space left on device   This is come of the stuff that i am doing at last in my code  sed -n '/.*needs to be executed manually.*/{n;p}' "$ERR_LOG"*  sed -n '/.*have.*latest.*/{n;p}' "$ERR_LOG"* >> "$ERR_LOG"final.log   sed -n '/.*Phone type not recognised.*/p' "$ERR_LOG"* >> "$ERR_LOG"final.log   sed '/.*#/!{H;d;} x;/\n.*Error/!d' "$ERR_LOG"* >> "$ERR_LOG"final.log   sed '/.*#/!{H;d;} x;/\n%/!d' "$ERR_LOG"* >> "$ERR_LOG"final.log   sed is seraching through around 10 - 15 files of size=50-69 kb (approx)  EDIT 1 : This is the exact error :  sed: couldn't write 166 items to stdout: No space left on device sed: couldn't write 201 items to stdout: No space left on device All the hostnames processed sed: couldn't flush /home/gocs1/LOG//sed6hkHBu: No space left on device sed: couldn't flush /home/gocs1/LOG//sedM2dr4u: No space left on device sed: couldn't flush /home/gocs1/LOG//sed6A8NWu: No space left on device sed: couldn't flush /home/gocs1/LOG//sedbmkv3x: No space left on device sed: couldn't flush /home/gocs1/LOG//sed42pjSx: No space left on device sed: couldn't flush /home/gocs1/LOG//sedMKxrHy: No space left on device Time Taken : 0 hour(s) 58 minute(s) 33 second(s)   what does this mean.    /home/gocs1/LOG//sed6hkHBu   i have created the directory upto /home/gocs1/LOG/ but the rest(/sed6hkHBu) is not created by me.  EDIT 2 : does sed or sed -i option creates files in tmp directory i had many files  created in /tmp/LOG directory with one file of huge size(800 MB) also while the script was running.

Due to an application bug as yet undiagnosed, I have several hundred servers with a full disk.  There is one file that has been filled up with duplicate lines—not a log file, but a user environment file with variable definitions (so I can't just delete the file).  I wrote a simple sed command to check for the erroneously added lines and delete them, and tested it on a local copy of the file.  It worked as intended.  However, when I tried it on the server with the full disk, I got approximately the following error (it's from memory, not copy and paste):  sed: couldn't flush /path/to/file/sed8923ABC: No space left on deviceServerHostname   Of course, I know there's no space left.  That's why I'm trying to delete stuff!  (The sed command I'm using will reduce a 4000+ line file to about 90 lines.)  My sed command is just sed -i '/myregex/d' /path/to/file/filename  Is there a way I can apply this command despite the full disk?  (It must be automated, since I need to apply it to several hundred servers as a quick-fix.)  (Obviously the application bug needs to be diagnosed, but in the meantime the servers aren't working correctly....)    Update: The situation I faced was resolved by deleting something else that I found out I could delete, but I'd still like the answer to this question, which would be helpful in the future and for other people.  /tmp is a no-go; it's on the same filesystem.  Before I freed up disk space, I did test and find out that I could delete the lines in vi by opening the file and running :g/myregex/d and then successfully save the changes with :wq.  It seems it should be possible to automate this, without resorting to a separate filesystem to hold a temp file....  (?)


I am working on some stuff for a paper.  I have recently seen an advert for a conference calling for papers and I feel like I currently have enough stuff that I could submit it to this conference and get it published.  However, it looks as if the paper would be published in the 'conference proceedings' as part of a series by Springer.  Does this mean that the publication would only be classed as a 'conference paper' and do conference papers really carry the same weight as journal publications?   (It's worth mentioning that the paper would be peer-reviwed if I sent it for the proceedings of this conference). If not, my idea would be to wait until I have added more to what I am working on and then send it to a journal.  Edit: I am aware that there are other questions asking if a conference paper should be compared to a journal article.  I am asking if in this case the publication can be listed as a journal article as it will be peer-reviewed by experts and published in Communications in Computer and Information Science, so I am wondering if this allows a work-around for me to class it as one of my journal articles.  The link below provides more information: I would like to know if I can list it as a peer-reviewed journal paper or if I will have to call it a conference paper, as these are not the same to me.    Second edit: To make it clear the paper would be a physics paper on the subject of quantum mechanics and would only be published in CCIS as it represents a surprising application of a particular piece of computer software.  My issue is that I don't want to see the paper as a novelty item when I have been thinking about and working on the physics going into it for years.  The use of software in it is really just a matter of convenience as there is a bit where it it easier to use software to generate a numerical example illustrating the general theory I have been talking about in a concrete case.  Third edit: Turns out the publication could only be classed as a conference paper so I will add to what I have got and send it to a journal, as I don't regard a conference paper as being equivalent to a journal publication (or at least, not in physics).

Many times I heard about papers published in conference. But still I am not able to find the major difference between papers published in a conference and those published in a journal. What is the difference?


I have a program in JAVA that I am working on. It uses recursion to count up based on the number entered. I'm using a while loop that loops if an error is thrown. I'm trying to code a feature that allows the user to continuously enter numbers until n/N is entered with a do/while loop. Here is my code so far:  public static void main(String[] args){     Scanner keyboard = new Scanner(System.in);      System.out.print("Enter a number: ");     String input;     input = keyboard.nextLine();             String again;     do{         while(true){             try{                 int number = Integer.parseInt(input);                 int base = 1;                 /*                   The countUp function is called from                   from my parent class SimpleRecursion.java                   which is where the recursion happens                 */                 countUp(base, number);                  break;                             }              catch(NumberFormatException e){                 System.out.print("Error invalid entry." + "\n" + "Enter a number: ");                 input = keyboard.nextLine();                 continue;             }         }          System.out.print("Again? y or n? ");         again = keyboard.nextLine();         if(again.equals("n") || again.equals("N"))             System.exit(0);     }while(again.equals("y") || again.equals("Y")); }   However, when the try block breaks out of the while loop it seems to end the program. I've tried labeling my do loop A and the while loop B and using "break B", to break out of the while loop but that did not work either. Also: my Scanner import is at the top of the parent class. I can post the entire file, the code would work fine for a single correct input and the program loops correctly if the NumberFormatException is thrown. Thanks.  EDIT: I changed again=="string" to again.equals("string") and the results were the same.  The problem was in my countUp function which looked like this:  public static void countUp(int x, int end){     if(x > end)         System.exit(0); // When the number reaches the number entered. The                          // program ended.      else{         System.out.print(x + "\n");         countUp((x+1), end);     } }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Let $f: \mathbb{R}^n \rightarrow \mathbb{R}$ be a convex function on $\mathbb{R}^n$. How to prove that $f$ is continuous?

I'm trying to solve the following problem:  Let $f:K\rightarrow \mathbb{R} $, $f$ convex and $K \subseteq \mathbb{R}^n$ convex. Then $f$ is continuous on $K$.   I have proved the only case $n=1$, but for an arbitrary $n$??


I'm trying to install google earth pro in ubuntu from command line to implement Liquid Galaxy, following the HOWTO ()  sudo apt install gdebi-core wget wget https://dl.google.com/dl/earth/client/current/google-earth-pro-stable_current_amd64.deb sudo gdebi google-earth-pro-stable_current_amd64.deb   and it returns errors:  Error: could not find xdg-icon-resource when installing google-earth-pro-stable dpkg: error processing package google-earth-pro-stable (--install)  installed        google-earth-pro-stable package post-installation script subprocess returned error exit status 1 Errors were encountered while processing: google-earth-pro-stable   Can anybody help me to understand how to install Google earth for LiquidGalaxy?

I am new to Ubuntu.   I need Java 8 & NetBeans but cannot install. I tried by downloading something, but it did not get installed.  I tried same way for Google Earth, but it is also not installed.  First I tried Ubuntu 13.x (32 bit), but had same issue after I installed Ubuntu 14.04 LTS (64-bit).    Where can I got to get good advice on installation of software, and for using Ubuntu effectively?


I'm creating a space opera video game and I was wondering if to be considered a Space Opera it had to feature some supernatural abilities like Star Wars has with the Force. Or can I completely forgo that entire idea altogether and keep the rest of what the Wikipedia page says about Space Operas?

A while back a guy came into the place where I was working. He had a book (I don't remember the name). The book was, according to him, scifi. I told him, "Great! My favorite scifi is the Skylark Series by EE Doc Smith!" He sort of tsked this, saying, "Oh, that's only space opera." I really didn't know what to think of what he said. The funny thing was, I remembering looking at his book thinking, what makes his book scifi any more than mine.  I started thinking about this incident the other day and am once again curious:  What is the difference between space opera and science fiction? What identifies each genre specifically?    NOTE: I had originally asked this on meta due to the closed question:  which is very similar to my question. It was subsequently moved to the main site.


Consider $n > 1$ consecutive integers $a, a+ 1, . . . , a+ (n−1)$. Prove that the product thereof is always a multiple of $n!. (Think about a number of the form C y x .)

How can we prove that the product of $n$ consecutive integers is divisible by $n$ factorial?     Note: In this  and the comments here the OP has clarified that he seeks a proof that "does not use the properties of binomial coefficients". Please post answers in said newer thread so that this incorrectly-posed question may be closed as a duplicate.


When inserting a figure or table, you can add a caption. It has some default styling that you can edit in the Quick Styles pane. By default in Word 2013 this is a 9pt italic font. Unfortunately, this makes the caption and the text itself italic, e.g.      Table 1 Income breakdown   . My academic guidelines, however, indicate that captions should not be in italics, with exception of the enumeration of the figure or table. Some punctuation is necessary as well, e.g.      Table 1. Income breakdown.   Is there any way this can be achieved in an automated manner?

This should be a common problem for anyone involved in technical writing.  When you insert an image (or table etc.) caption in Word, you get  dialog. You enter your caption,  "A happy bicycle" (in yellow).  This might be fine for a happy bicycle, but I want to have captions that have one style for the "enumeration" (label and number) and one style for the description (caption text, as called by Word), as such:    I have tried searching for this but I haven't found anything yet...


I want to print all the characters in a string as a list but for each character to be printed once even if recurring. So far I have:  symbolsx = [] for line in ''.join(word_lines):    for i in line:        symbolsx.append(i)   This prints every character, even if the character is repeated.

Is there a built-in that removes duplicates from list in Python, whilst preserving order? I know that I can use a set to remove duplicates, but that destroys the original order. I also know that I can roll my own like this:  def uniq(input):   output = []   for x in input:     if x not in output:       output.append(x)   return output   (Thanks to  for that .)  But I'd like to avail myself of a built-in or a more Pythonic idiom if possible.  Related question:


After a command is entered in a terminal I am then asked for a password but the terminal freezes and won't let me enter the password. How do I fix this.

When I'm about to install a program in the terminal it wants the password:  [sudo] password for xxx:   But when I start to type my password nothing happens. What should I do?


When a sequence of sets has a limit ? I want to know the definition

I am starting to learn about the liminf and limsup of a sequence of sets. However, I do not understand the very basics, such as why $\lim\sup A_n=\bigcap_{n\in N}\bigcup_{k>n} A_k,$ and why $\lim\sup A_n=\bigcup_{n\in N}\bigcap_{k>n}A_k.$ Can someone break these definitions down for me?  Also, why is $\lim\inf\subseteq\lim\sup$?


am trying to find the best way/approach for performance of using different block usage. i am running the below palindrome program with 3 different way measuring the executing time for each. but i always get '0' as output. what is wrong in my code. please help me.  main      long startTime, endTime, duration;      startTime = Instant.now().toEpochMilli();     System.out.println(palindromeUsingStringBuilderReverse(str));     endTime = Instant.now().toEpochMilli();     duration = (endTime - startTime);     System.out.println("Duration for using string builder : " + duration);      startTime = Instant.now().toEpochMilli();     System.out.println(palindromeUsingForLoop(str));     endTime = Instant.now().toEpochMilli();     duration = (endTime - startTime);     System.out.println("Duration for using for loop : " + duration);       startTime = Instant.now().toEpochMilli();     System.out.println(palindromeUsingWhile(str));     endTime = Instant.now().toEpochMilli();     duration = (endTime - startTime);     System.out.println("Duration for using while loop : " + duration);   palindromeUsingStringBuilderReverse  StringBuilder bdr = new StringBuilder(str);         if (str.equalsIgnoreCase(bdr.reverse().toString())) {             return "The given string is a Palindrome.";         } else {             return "This is not a Palindrome string.";         }   palindromeUsingForLoop  String revStr = ""; for (int i=str.length()-1; i>=0; i--) {                 revStr = revStr + str.charAt(i);                 }      if (str.equalsIgnoreCase(revStr)) {                 return "The given string is a Palindrome.";             } else {                 return "This is not a Palindrome string.";             }   palindromeUsingWhile      int i = 0, j = str.length() - 1;     while (i < str.length()) {         if (str.charAt(i) != str.charAt(j)) {             return "This is not a Palindrome string.";         } else {             i++;             j--;         }     }     return "The given string is a Palindrome.";   output on execution  Enter a word to check its a palindrome or not : madammadammadammadammadammadammadammadammadammadam The given string is a Palindrome. Duration for using string builder : 0 The given string is a Palindrome. Duration for using for loop : 0 The given string is a Palindrome. Duration for using while loop : 0  Process finished with exit code 0

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


For some reason powershell is displaying operators and parameters as invisible. Using this question I can fix this:   $colors = @{Operator="Green";Parameter="Green"} Set-PSReadLineOption -Colors $colors   This is good, but then if I close Powershell and bring it up again it has reverted back to the original settings.  A comment on  says "Add the settings to your profile".  How do I do this? How do I add these settings to my profile?

With PowerShell 5.0, there are lot of customization options. Presently I have created my own color scheme. But I couldn't figure it out how to set these color options permanently.  Set-PSReadlineOption -TokenKind Operator -ForegroundColor "Magenta" Set-PSReadlineOption -TokenKind Command -ForegroundColor "DarkYellow" Set-PSReadlineOption -TokenKind Parameter -ForegroundColor "Magenta"   Now I kept these commands in Profile script, so that they will be loaded automatically, however it doesn't work in all cases when the shell is reset and if I want to load another Profile. Irrespective of profiles, the background color and other options which are available in PowerShell UI remain consistent. I want the same thing.  How do I permanently set these color options for PowerShell Console.


Once an Area 51 proposal has entered the commitment phase, is there a deadline by which it needs to achieve critical mass?  I found a couple questions lamenting about how long it takes to get enough commitments (e.g., ), so presumably it's a long time.   But does that mean a site could reach beta a year after entering the commitment phase? 6 months? Or are proposals intended (either manually or automatically) to be quashed after a month or two due to lack of critical mass?

Is there any kind of time frame in which new proposals are expected to attain the requisite number of followers to move to the next phase?  I can see where if it takes a year to gather enough followers to take the proposal to beta then maybe the proposal can come into question, but I can also see where others might take longer.  Or is the thought to go ahead and let it take as long as it takes and then it'll all get sorted out during the beta period?


Is it possible to write the Lagrangian density for the EM field and charges $$L=-\frac{1}{4\mu_0}F^{\mu \nu}F_{\mu \nu}+j^{\mu}A_{\mu}$$ only in terms of the Electromagnetic Tensor and current vector? Can you also solve the Euler-Lagrange equation without reference to the potential? For example, witht the Lagrangian density for empty space: $$L=-\frac{1}{4\mu_0}F^{\mu \nu}F_{\mu \nu}$$ There are no derivatives of $F^{\mu \nu}$, so I don't see how you could derive the field equations from it.

Is it possible to formulate classical electrodynamics (in the sense of deriving Maxwell's equations) from a least-action principle, without the use of potentials? That is, is there a lagrangian which depends only on the electric and magnetic fields and which will have Maxwell's equations as its Euler-Lagrange equations?


I'm trying to write something that stores an API access token in a bash variable, so I'm modelling it on ssh-agent, where you use eval.  ssh-agent  If you run ssh-agent by itself, it outputs something like the following:  SSH_AUTH_SOCK=/tmp/ssh-XXXXXXXXXXXX/agent.NNNNN; export SSH_AUTH_SOCK; SSH_AGENT_PID=NNNNN; export SSH_AGENT_PID; echo Agent pid NNNNN;   And if you run it with eval $(ssh-agent), it outputs:  Agent pid NNNNN   ...and the eval results in the environment variables being set in your current shell.  my script  The end of my script looks like this ($JSON came from some earlier curl command):  cat <<EOF API_ACCESS_TOKEN=$(echo $JSON | jq '.access_token') API_EXPIRES_AT=$(echo $JSON | jq '.expires_at') export API_ACCESS_TOKEN API_EXPIRES_AT echo OK EOF   When I run it with eval $(./auth), it's correctly setting $API_ACCESS_TOKEN and $API_EXPIRES_AT (so the eval works), but it's not printing "OK".  What am I doing wrong?

Or, an introductory guide to robust filename handling and other string passing in shell scripts.  I wrote a shell script which works well most of the time. But it chokes on some inputs (e.g. on some file names).  I encountered a problem such as the following:   I have a file name containing a space hello world, and it was treated as two separate files hello and world. I have an input line with two consecutive spaces and they shrank to one in the input. Leading and trailing whitespace disappears from input lines. Sometimes, when the input contains one of the characters \[*?, they are replaced by some text which is is actually the name of files. There is an apostrophe ' (or a double quote ") in the input and things got weird after that point. There is a backslash in the input (or: I am using Cygwin and some of my file names have Windows-style \ separators).   What is going on and how do I fix it?


I need to symbolize a vector layer in Arcmap based on RGB (or HSB - can do either) values found in fields in the attribute table. I'm working with up to 10 different datasets, each with over 100 features. As a result, I can't manually adjust each feature's fill attribute, nor can I use a template .lyr file and then apply its symbology.  Is there a method via Arcpy that I can use to perform this?   Looking at the documentation it appears that symbology isn't exposed to Arcpy but I'm not familiar enough to know for sure.   Otherwise, are there any third-party scripts or tools that can accomplish this?

I have an excel file with 2 attribute columns, 1-feature info 2-Number of color (RGB) that the current feature should be symbolize. This file file can be joined with the layer using the "feature info" field which is unique (join by attribute table). So i have as attribute the color number attribute for every polygon feature.  How can  i use this this information to symbolize every feature with their attributed color already imported from the excel sheet?


Looking for a clever title for a short paper on Oscar Wilde's humor, where the reader can never quite figure out if he stands for something or nothing at all.  Any ideas are appreciated.

Is there any other phrase that conveys the same meaning as  the phrase "a chicken and egg situation" especially if one has to use this phrase in an official/corporate set up?


I have installed Ubuntu in my Dell-Inspiron-N5010 laptop today and it was looking like a complicated one, without knowing about the partition thing, So the result of that is, I can't access to a part of storage (means hidden) if there is any chance where i can repair that through the live CD or by other means?

So I noticed this question has not been asked directly;  What is this "Swap Area" people keep referring to when it comes to installing Ubuntu?


Sun the sun and many other stars shine their light outwardly, and light travels very long distances, why is space dark? Why isn't it all lit up due to the stars?

The question is the well-known      If there are so many/infinite stars, in every direction, why is it dark at night? Where goes all the light we don't see?    Discussing with a friend we found different answers.   The first (my friend's answer) is that given the fact that in a finite amount of time (in this case, the age of the universe), light can travel only a certain, finite, distance, we cannot see, if they actually exist, stars farther than such distance (about 13 billions of years, I guess). Then he states (or better, I got him notice he implicitly does this)  that within this radius there aren't enough stars to fill the night sky, and that's why we have darkness without sun's light.   The second answer (mine, or anyway the one I heard from a minutephysics YouTube video) is that despite of the big size of the observable universe, cosmological expansion red shifts most of the light out of the visible radiation range, so that the majority of light can't be seen by our eyes at night, while if we use, for example, an infrared camera, we should see a brighter sky, and lenghtening more and more the wavelength at which we observe the sky, we come to the uniform background radiation.  So my question is, what is the right answer? Is it one of the above-mentioned or even a third one?  EDIT: I've seen both answer may be acceptable, but what is the main contributing phenomenon?


Let $K$ be a field, $f\in K[t]$ separable over $K$, $L$ the splitting field of $f$ over $K$, and $G=\Gamma(L:K)$. I need to prove that $f$ is irreducible if and only if $G$ acts transitively on the roots of $f$.   I was able to show one direction, that $f$ irreducible implies $G$ acts transitively on the roots. I'm stuck on the other direction of implication; supposing $G$ acts transitively on the roots of $f$. Any guidance or a point in the right direction would be much appreciated!

Let $F$ be a field and $f\in F[X]$ a separable polynomial. Let $K_f$ be the splitting field of $f$ and $G_f=\text{Gal}(K_f/F)$ its Galois group. Show that $f$ is irreducible $\iff$ $G_f$ acts transitively on the roots on $f$. My work $\implies :$ Let $f\in F[x]$ irreducible, $\alpha \in K_f$ a root and $\alpha _1,...,\alpha _n$ the other roots of $f$ (so $K_f=F(\alpha ,\alpha _1,...,\alpha _n)$). What I have to show (I think) is that for all $i$ there is a $\sigma \in G_f$ s.t. $\sigma \alpha =\alpha _i.$ Q1) Is it right ? Q2) Is $f$ the minimal polynomial of $\alpha $ ? (To me it is, but my teacher said that it can be not the case, but I don't understand why). Since $\alpha $ and $\alpha _1$ have the same minimal polynomial, there is an isomorphism $\sigma :\alpha \longmapsto \alpha _1$. We can observe that $\sigma : F(\alpha )\longrightarrow K_f$. Now $F(\alpha ,\alpha _1)/F(\alpha )$ is algebraic, then we can extend $\sigma $ to a morphism $F(\alpha ,\alpha _1)\longrightarrow K_f$. Now, we can continue like that and extend $\sigma $ as $\psi: K_f\longrightarrow K_f$ s.t. $\psi(\alpha )=\alpha _1$. Q3) The fact that $\psi(\alpha )=\alpha _1$ comes from the fact that $\psi|_{F(\alpha )}=\sigma $, right ? The bijectivity is obvious since it's a field homomorphism and that $\sigma (K_f)=K_f$. Q4) How to conclude that $G_f$ act transitively on the roots ? I don't have particular problem for the converse.


In modern experiments,  With the classical setup of photons or electrons passing through double slit, the intensity is kept extremely low, such that one can detect a single particle passing through the double slit at a time.   Why this fact is so important?  Here I am asking for why there is need to keep Intensity to extremely low to detect a single particle ?

In a double-slit experiment, interference patterns are shown when light passes through the slits and illuminate the screen. So the question is, if one shoots a single photon, does the screen show interference pattern? Or does the screen show only one location that the single photon particle is at?


I want to output number of lines in text file.So I am using echo command but I am getting filename along with number of lines when I run the following code:  echo "$page" > t total="$(wc -l t)" echo "$total"   Output:     162 t  Note: Number of lines in file "t" are 162 only.

I have been trying to create a file called ~/dictwords.txt, which contains the number of words found in the file /usr/share/dict/words.  I already created the file then I removed it because I did it wrong I originally did the echo command. Then I tried this command and was so excited because I thought I was correct.  wc -w /usr/share/dict/words > ~/dictwords.txt   It's still wrong, I am supposed to have just the number, without a file name.


Consider a new SO user with insufficient reputation to make an edit with no approval.  When such users suggest an edit, they can hardly guess that it is possible to keep track of their edit, discover if it is either approved or rejected, and that there may be a comment that describes a reason of the rejection that can help avoid the same situation in future.  The issue is that this tracking information is hidden deep inside a user profile. You need to follow User Page → All Actions → Suggestions (possibly). There is a little chance that an average newcomer even knows what “suggestions” is for, even if they are curious enough to dig into every tab of their own profile.  So I propose to add a notification in the Recent inbox messages area when a suggested edit is either accepted or declined. The notification entry must lead to a review page of a corresponding edit.

Currently, when someone suggests an edit, they are unable to keep track of it without watching reputation levels or constantly refreshing the page. What I would like is a notification, that shows up like the notification where someone has edited your question, that shows whether a suggested edit has been approved or rejected after the last vote is cast. This way, the community can be notified when their edit has been rejected/approved, while focusing their efforts on another question/answer.


What does the Soul stone do? Why is it so important? Are the Mind and Soul Stone the same thing?  In Avengers: Infinity War, Thanos has to sacrifice his own daughter to get the Soul Stone when the Soul Stone seems useless.

Prior to Avengers: Infinity War, we are introduced to and acquainted with five of the six Infinity Stones, and their powers are demonstrated in action and observed by the audience.   However, the soul stone was hidden, and was introduced in this movie, but I don't remember it being used in the movie.  So, what does the Soul Stone actually do?


I have a laptop with an ssd for the main drive. I'm curious if anyone knows how ubuntu 18.04 stores data when you suspend/sleep a laptop. Is it writing each time to my ssd or does it keep the data stored in RAM in a lower power state? Given the limited nature of writes for ssd's I would like to avoid data being written every time I suspend the laptop because I do it a lot. Also, is suspend different for each release or is it a standard for all versions and distros? Thank you in advance.

Logout, Restart and Shutdown are all self explanatory to me.   What are the differences between Suspend and Hibernate on the shutdown menu?


I need to get current time in UTC to store in in datetime field(2019-08-17 00:00:00) type in MySQL.  How to get it in PHP?  I tried: now(); it gives me milliseconds

Which PHP function can return the current date/time?


I'm wondering if anyone could show me where my logic in this selection sort (yes it's for educational use, I realize that there's an Arrays.sort() method) is flawed.   public static void selectionSortByName() throws IOException {     String temp;     for (int i = 0; i <= nameArraySize; i++){          String smallest = name[i];           for (int j = 0; j <= nameArraySize; j++){             if (name[j].compareTo(name[i]) < 0){                 temp = smallest;                 name[j] = temp;                 name[i] = smallest;             }         }      }   }   I'm getting a NullPointerException on my line with the compareTo method, so I would expect that I just have a logic error in one of my conditionals.  Any help would be great, thanks!

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


$\sum _{k = 0}^ n \binom ka \binom {n-k}b = \binom {n+1}{a+b+1} $ Can anyone please give me a hint to prove it using combinatorics ? I know that $n \geq a+b$ and $k$ will run from $a$ to $n-b$ . But I think it should be $\binom {n}{a+b} $. Can anyone please help me?

Given two positive integers $a$ and $b$, prove that  $\sum_{k=0}^{n} {k \choose a} {n-k \choose b} = {n+1\choose a+b+1}$  I think there should be a good combinatorial proof for this, given the simplicity of the right-hand side... my hunch is to form all possible subsets of size $a+b+1$ by dividing the set into $k$ and $n-k$ elements, then choosing $a$ from the first, $b$ from the second, iterating over all values of $k$.  I can't quite make this work, so I've also been trying to rewrite ${n+1 \choose a+b+1}$ to make it clear.  Open to any proof method, all help appreciated.


I am trying to do a find replace in a string of text. I am using Regex like this:  Regex regexText = new Regex("Test.Value");  strText = regexText.Replace(strText, value);   In this example I am trying to find the string "Test.Value" in a text string. However if this value appears in the string the replace does not happen.  If I remove the dots eg:  Regex regexText = new Regex("TEST");  strText = regexText.Replace(strText, value);   If I put the word "TEST" in the string, it replaces it just fine.  Is there a way to get this to work with strings with "."'s in?

I am tired of always trying to guess, if I should escape special characters like '()[]{}|' etc. when using many implementations of regexps.  It is different with, for example, Python, sed, grep, awk, Perl, rename, Apache, find and so on. Is there any rule set which tells when I should, and when I should not, escape special characters? Does it depend on the regexp type, like PCRE, POSIX or extended regexps?


I am trying to understand how to create and use a library in C#. In a similar way of understanding it in C using GCC.   I want to only use the command line, and not use Visual Studio IDE.   How can I    Create a library, including   Writing the source file, where do I have to use namespace and if yes, do I have to choose the namespace representing the directories where the library file is in? Compiling it into a dll file?  Use the library's dll file in another C# program?

How do you compile and execute a .cs file from a command-prompt window?


I have a script to verify the positional parameters it receives  $ cat myscript #! /bin/bash echo $0 echo $1 echo $2   When I run it via different ways  $  ./myscript    ./myscript  $ bash ./myscript  ./myscript  $ source myscript /bin/bash   Suppose I have to write another script which needs to get the pathname to the parent directory of the script:  #! /bin/bash  echo $(dirname "$(readlink -f "$0")")   and I have to run it by source it. Then it won't work, because $0 is /bin/bash. I wonder how I can get the pathname to the parent directory of the script within itself, when source it? Thanks.

Is there a way for a sourced shell script to find out the path to itself? I'm mainly concerned with bash, though I have some coworkers who use tcsh.  I'm guessing I may not have a ton of luck here, since sourcing causes commands to be executed in the current shell, so $0 is still the current shell's invocation, not the sourced script. My best thought currently is to do source $script $script, so that the first positional parameter contains the necessary information. Anyone have a better way?  To be clear, I am sourcing the script, not running it:  source foo.bash


Sentence that needs correction:     "Angela was curious about the unopened letter on the table and wondered for whom  it was meant."   I think the whom should be replaced with who because the sentence can be rewritten as      Angela was curious about the unopened letter on the table and wondered "who was it meant for?"   Correct answer: the sentence contains no error.   why am I wrong?

Many times, I've been asked the difference between "who" and "whom". I myself know the difference, but it is hard to explain to others. What is the easiest way to explain it to those with a basic understanding of English? A mnemonic (if possible) would help.


What is the most efficient way to check a certain condition on every element of an array and return false if one or more elements do not meet the condition, for example, I have this array for example  arr = ["foo","azeaze", "wazeazerar"]     for(var ar in arr){       if(ar.length > 5){         console.log(false)       }else{         console.log(true)       }      }   as you can see it return true even if the element "foo" length is not greater than 5

I've been told not to use for...in with arrays in JavaScript. Why not?


Is there any sensible reason to use layered .tifs as work files instead of .psd? I recieved a layered .tif file from other agency designer and was baffled as why would someone use it as a format for handing over to someone else. Is this a compatibility issue? Both author and I are working on Adobe CC package, latest versions.  Same goes for embedding files in Illustrator or InDesign. Is there any advantage to convert .psd file to .tif and then link it? In my opinion it impedes workflow - it adds unnecessary steps between editing .psd file and seeing it in other compatibile program.

I was reading a few articles about how people saved their working files and it got me thinking about my own method. I used to save everything as a PSD, but recently I have started saving my working files as TIFF's. I use Windows, so I don't know if it's different for Apple users but with a PSD, all I can see is that "PSD" icon. But a TIFF file shows up as a normal image (that I can edit), so I found it really great when I have a lot of working files for one project and could just quickly preview it without opening the program.  That being said, I am no expert in which method is better. And I know a lot of people here are pretty seasoned users in all things Adobe, so I was wondering what your two cent on the whole topic is?   Is there really any difference to saving it as a PSD or TIFF? Is there something I should specifically know about saving my files as a TIFF rather than a PSD?


Exercise 47 in Section 2.7 of Royden&Fitzpatrick's Real Analysis Book says that "a continuous strictly increasing function that is defined on an interval maps Borel sets to Borel sets".  But here do we need the continuity condition really? Because it seems that, without any continuity condition, the result follows directly from two preceding exercises, one of which says that "a strictly increasing function that is defined on an interval has a continuous inverse", and the other asserts that "if $f$ is a continuous function and $B$ is a Borel set, then $f^{-1}(B)$ is a Borel set".  I think that the continuity condition is superfluous. Am I right? Or, is there a detail which I cannot see? Thanks in advance for any comment.  EDIT: Here I just wanted to know that if the aforementioned exercise in Royden&Fitzpatrick's Real Analysis Book can be stated as "a strictly increasing function that is defined on an interval maps Borel sets to Borel sets". And I see that the answer is "yes". Thanks for the link.

I'm studying measure theory and two question came to my mind:        If $f:\mathbb{R}\to\mathbb{R}$ is monotone and $B\subseteq\mathbb{R}$ is borel, is the image $f(B)$ borel?   If $f:\mathbb{R}\to\mathbb{R}$ is a monotone function (say, non-decreasing), does there exist a sequence of continuous functions $f_n:\mathbb{R}\to\mathbb{R}$ converging pointwise to $f$?      Here's the motivation for those questions: Let $(X,M)$ and $(Y,N)$ be measure spaces.   It's known that if $\mu$ is a measure on $(X,M)$ and $f:X\to Y$ is measure, then we have the pushforward measure $f_*\mu(A)=\mu(f^{-1}(A))$ on $(Y,N)$. What if we were to define a "pullback measure"? Given a function $f:X\to Y$ such that $f(M)\subseteq N$ (i.e. $f$ maps measurable sets to measurable sets) and a measure $\nu$ on $N$, the natural formula would be $f^*\nu(A)=\nu(f(A))$. So we ask if is there a good amount of functions which map measurable sets to measurable sets in $\mathbb{R}$, and monotone functions seem like good candidates (for strictly monotone, continuous functions, the result is valid and there are several answers on the web). If this were true, maybe we could use some convergence argument to solve the problem above.


The "self-learner" badge description states "Answered your own question with score of 3 or more", but does that mean the question should have a score of 3 or more, or is it the answer that should have 3 or more?  If it's the answer, perhaps the description should make it clearer. For example:     Answered your own question, and got a score of 3 or more on the answer

Stemming from  the text for "Self-Learner" badge is pretty easy to get confused by.  Current Text     Answered your own question with score of 3 or more    Issue  The person in the above question was confused as they thought they needed to answer their own question, and that the question had to have a score of 3 or more. What it actually means is that they have to answer their own question, and the answer needs to have a score of three or more. The way it is phrased is ambiguous, so why not make it clear?  Suggestion  Edit the text as follows:     Provide an answer with a score of 3 or more to your own question   No more confusion.


Our calendar is based on Julius Caesar's calendar.      Our calendar was based on Julius Caesar's calendar.   Which is correct "is" or "was"?

Which is correct:     Florence is built on both sides of the Arno River.   or     Florence was built on both sides of the Arno River.    Source:


I have a question concerning the characterization of open sets in a metric space.  Per definition a set O in a metric space (X,d) is open, if it is a neighborhood of each of its points.  In the book "Introduction to Topology" by Mendelson () there  is the following characterization:  Theorem (5.2):  A subset O of a metric space (X,d) is an open set if and only if it is the union of open balls.  The proof of one direction is as follows: Suppose O is open. Then for each $a \in O$, there is an open ball $B(a;\delta_a) \subset O$. Therefore $O = \bigcup_{a \in O} B(a;\delta_a)$ is a union of open balls.  Now I wonder: Does this argument require the axiom of choice?   You need a 'choice function' which assigns to each $a \in O$, an element $\delta_a$ from the (non empty) set of all $\delta$'s where $B(a;\delta) \subset O$.

I am reading "A Course in Analysis vol.3" by Kazuo Matsuzaka.    There is the following proposition in this book.    Does the author use the axiom of choice in the proof?    Proposition 4:       A subset $A$ of a metric space $X$ is open in $X$ if and only if $A$ is a union of open balls in $X$.     Proof:       An open ball is open, so a union of open balls is open. Conversely, if $A$ is open and $a \in A$, then there exists a positive real number $r(a)$ such that $B(a ; r(a)) \subset A$. Obviously $$A = \bigcup_{a \in A} B(a ; r(a))$$ holds.     I think the author's proof uses the axiom of choice as follows:    Let $S_a := \{x \in \mathbb{R} | x > 0, B(a ; x) \subset A\}$. Since $A$ is open, for any $a \in A$, $S_a \ne \emptyset$. So, by the axiom of choice, there exists a mapping $r$ from $A$ to $\bigcup_{a \in A} S_a$ such that $r(a) \in S_a$.