is there any difference b/w `  $(this).parent().children(".name")    and  $(this).parent().find(".name")   ? Both these function return the same object. When I do   console.log($(this).parent().children(".name"));   and   console.log($(this).parent().children(".name"));   both these function print object of div name on console..
To select a child node in jQuery one can use children() but also find().   For example:  $(this).children('.foo');  gives the same result as:  $(this).find('.foo');  Now, which option is fastest or preferred and why?
I was laying on my bed, reading a book when the sun shone through the windows on my left. I happened to look at the wall on my right and noticed this very strange effect. The shadow of my elbow, when near the pages of the book, joined up with the shadow of the book even though I wasn't physically touching it.   I have posted :The video seems to be the wrong way up, but you still get the idea of what is happening.  What is causing this? Some sort of optical illusion where the light gets bent?  Coincidentally, I have been wondering about a similar effect recently where if you focus your eye on a nearby object, say, your finger, objects behind it in the distance seem to get curved/distorted around the edge of your finger. It seems awfully related...  EDIT: I could see the bulge with my bare eyes to the same extent as in the video! The room was well light and the wall was indeed quite bright. Is time dilation an illusion? It is said that we can verify time dilation by flying a very accurate clock on a fast jet or spaceship and prove that it registers less time than the clocks on earth. However, the clocks on earth would be moving relative to the clock on the spaceship, and since time always dilates and never goes faster regardless of the direction of relative motion,  the clocks on earth should register less time than the clock on the spaceship.  Is this true? Whenever there is a fast-moving object such as a rocket do all clocks on earth really become slow?  If the rocket with the clock landed after moving at relativistic speed, would its clock and the earth's clock again show the same time since during its travel both appeared slow to each other?  Or is all this just an illusion, ie. the clocks just appear to be slow to each other but in actually run at normal speed, and neither is behind when the rocket actually lands? How do you reopen a closed question? What's the simplest way to do a find and replace for a given input string, say abc, and replace with another string, say XYZ in file /tmp/file.txt?  I am writting an app and using IronPython to execute commands through SSH &mdash; but I don't know Unix that well and don't know what to look for.  I have heard that Bash, apart from being a command line interface, can be a very powerful scripting language. So, if this is true, I assume you can perform actions like these.  Can I do it with bash, and what's the simplest (one line) script to achieve my goal? Why is sample standard deviation a biased estimator of $\sigma$? Can generated OpenVPN keys be used on multiple clients? We are experimenting with running an OpenVPN server for our business. One question I can't seem to find the answer to is this:  When we generate keys for one of our users for them to use at home, can their use the same keys on their home laptop as well as their home desktop? Or do we need to generate separate keys for each user's client machine? youtube-dl failed to extract signature I can't seem to access instance members of the surrounding class from inside an enum, as I could from inside an inner class. Does that mean enums are static? Is there any access to the scope of the surrounding class's instance, or do I have to pass the instance into the enum's method where I need it?  public class Universe {     public final int theAnswer;      public enum Planet {         // ...         EARTH(...);         // ...          // ... constructor etc.          public int deepThought() {             // -&gt; "No enclosing instance of type 'Universe' is accessible in this scope"             return Universe.this.theAnswer;         }     }      public Universe(int locallyUniversalAnswer) {         this.theAnswer = locallyUniversalAnswer;     } } Why is radian so common in maths? I have learned about the correspondence of radians and degrees so 360° degrees equals $2\pi$ radians. Now we mostly use radians (integrals and so on)  My question: Is it just mathematical convention that radians are much more used in higher maths than degrees or do radians have some intrinsic advantage over degrees?  For me personally it doesn't matter if I write $\cos(360°)$ or $\cos(2\pi)$. Both equals 1, so why bother with two conventions? Specific vocabulary for making someone laugh by rubbing their underarm with finger I'm trying to connect to a sandbox using the sfdx cli and the JWT flow through force:auth:jwt:grant. According to , we can use the same connected app information from Production to connect to our Scratch Org.  Is it something that should work for sandbox too ? I'm getting a "Failed: Not approved" error.  Connected app in sandbox comes from the refresh but has a different consumer key. The Permission set is set correctly on my user.  Is there a way to connect to a recently refreshed sandbox using the JWT flow (without manually changing something like the consumer key) ? right now when I connect to my VPN, my internet is served from my home router, but any requests for xxx.xxx.xxx.xxx i.e. my works ip range are served via the vpn connection I believe.  How can I force all traffic to the vpn? Action to crop a photo with user input. The batch processing I'm stumped.  All I need to do is open my photo, have the action stop to wait for me to decide where the crop should be (to center the important part of the photo), then close that photo so the batch processing can go get the next photo.  I see the "inset stop" is the key, but it never allows me to crop, it just moves on to the next photo. Why can't light escape from a classical black hole? Indian passport threading coming off My Indian passport threading is coming off i.e. the cover of the passport is coming off, there are only 2 threads remaining.   Will it be a problem at the airport when going abroad ? Also anyone who has experience of getting a replacement passport fairly quick ? Because I need to get a passport in like 15 days. How to specify font size less than 10pt (or more than 12pt)? I'm trying to make a document that has a very small font throughout, I tried this:  \documentclass[0.5mm, a4paper]{article} \documentclass[7pt, a4paper]{article}   But it doesn't seem that they allow me to go anything below 10pt.  This hack make it work, but not for the section headers:  \fontsize{4mm}{5mm}\selectfont   Does anyone know any better ways to do this? Distorted Cabin & Oily Sheen: What is going on in this paragraph? I have been reading a book, and I have a question about the following excerpt:  &quot;We're here,&quot; The Tortoise in the Lake said, cutting across Dong Huong's gloomy thoughts. &quot;I can see nothing.&quot; There came a low rumble, which distorted the cabin around her, and cast an oily sheen on the walls. &quot;Watch.&quot; Outside, everything was dark. There was only the shadow of The Two Sisters in Exile, the dead ship that they'd been pulling since Longevity Station. – The Two Sisters in Exile, a fantasy novel by Aliette de Bodard  Are these changes happening in the “real” life of the novel?, or are they an illusion that exists merely in the mind of the narrator? If they are only an illusion, why does the author not say so? Has the author omitted something, or are these changes are really happening as the author says? I'm trying to install a Matlab R2011a launcher for Unity in Ubuntu 12.04. I've tried  (although I know it's for 11.10 and mentions that even 11.10 is an unsupported OS for Matlab R2011a) but without any satisfactory solution.  This is my launcher file, /usr/share/applications/matlab.desktop:  #!/usr/bin/env xdg-open [Desktop Entry] Type=Application Icon=/usr/share/icons/matlab.png Name=MATLAB R2011a Comment=Start MATLAB - The Language of Technical Computing Exec=matlab -desktop Categories=Development;   I open the dash panel and search for "matlab". This launcher is found among applications. I click it, and Matlab's splash screen shows up, but when it disappears the program doesn't start. (I've verified with htop that no matlab-processes are running in the background either.)  If I add  Terminal=true   to the launcher file, the program starts OK, and opens a terminal as well as Matlab. However, both the terminal and Matlab itself show up in the Launcher area, with the Matlab icon, so it looks like I have two Matlab instances running when really it's only one. (Actually, they show up as two different programs, and not just two instances of the same - the icons are independent, not grouped together.)  This is definitely not optimal. I had hoped to create a launcher I can lock to the launcher area, and then that same icon will be the icon for the active Matlab instance when the program is running.  How do I create a launcher for Matlab that works as expected?  Update: I was apparently a bit unclear on my symptoms, I'll try to clarify a little. I've also tried some suggestions from the answers, and further investigated what happens. My current setup (a launcher file with Terminal=true and Exec=matlab -desktop -nosplash &amp;) renders the following behavior:   I open Dash by pressing the Windows key on my laptop, and search for "matlab". It finds the launcher named "MATLAB R2011a". I click it. A terminal window opens, using the icon I referred to in the launcher file. Almost immediately, MATLAB's splash screen also opens, using the same icon (and thus being grouped with the terminal window in the launcher). The splash screen disappears and, so does one of the icons in the launcher. The MATLAB desktop environment opens, using a different version of the icon which is displayed next to the icon for the terminal window (not grouped with it).   I can lock the terminal window's icon to the launcher and successfully start MATLAB by clicking it, but it doesn't feel optimal that I start the program with one icon, and switch to it with another. I've also tried the following:   Exec without the ampersand &amp; in the launcher command, but it didn't make a difference. Executing matlab -nosplash manually from a terminal still shows the splash screen. (What, then, does the nosplash option really do?) UEFI machine doesn't boot Ubuntu through NVRAM bootcatalog. How to fix? The line numbers for the text of a paragraph with an equation defined by \begin{align} command do not show as expected. How to fix this?    The LaTeX codes are attached here.   \documentclass[a4paper, 12pt]{article} \usepackage[utf8]{inputenc}    % Use the UTF-8 encoding \usepackage{amsmath}           % For the use of math \usepackage{amsfonts} \usepackage{amssymb}           % For the use of AMS symbols \usepackage{indentfirst}       % For indentation \usepackage[top=2cm, bottom=2cm, left=2cm, right=2cm]{geometry}  \usepackage{lineno} \linenumbers  \usepackage{titlesec} \titleformat*{\section}{\large\bfseries} \titleformat*{\subsection}{\normalsize\bfseries} \titleformat*{\subsubsection}{\normalsize}   \renewcommand{\baselinestretch}{1.5}    \usepackage{authblk}           % Use author package \renewcommand*{\Authfont}{\large} \renewcommand*{\Affilfont}{\normalsize\normalfont}  \makeatletter \g@addto@macro\normalsize{%   \setlength\abovedisplayskip{0pt}   \setlength\belowdisplayskip{0pt}   \setlength\abovedisplayshortskip{0pt}   \setlength\belowdisplayshortskip{0pt} } \makeatother  \title{\textbf{Globally cumstomize the spacing between the text and equation}}    \date{}  \begin{document}  \maketitle  \section{Air filter} The air filter is simulated by the Control Valve module (AFT in Fig. 2(a)). The pressure drop through the air filter ($ \Delta P_{af} $) is given by the following equation [11,16]. \begin{align} \Delta P = \Delta P_{d} \left( \frac{m}{m_{d}}\right)^{1.84}  \left( \frac{T}{T_{d}}\right)  \left( \frac{P}{P_{d}}\right)^{-1}  \end{align} where, $ \Delta P_{af} $ is the pressure drop, $ m $ is the mass flow rate, $ T $ is the temperature, and $ P $ is the pressure, and subscript $ d $ denotes the design condition.  \newpage \section{Air compressor (AC)} The AC operating characteristics can be described by its performance map, which relates the following dimensionless operational variables. The AC operating characteristics can be described by its performance map, which relates the following dimensionless operational variables. \begin{align} &amp; \text{Relative pressure ratio:} &amp;&amp; PR_{r} = \frac{PR-1}{PR_{d}-1}\\ &amp; \text{Relative isentropic efficiency:} &amp;&amp; \eta_{r} = \frac{\eta}{\eta_{d}} \\ &amp; \text{Relative corrected mass flow:} &amp;&amp; m_{cor,r} = \frac{\left(\frac{m_{in}}{P_{in}}\sqrt{T_{in}}\right)}{\left(\frac{m_{in,d}}{P_{in,d}}\sqrt{T_{in,d}}\right)} \\ &amp; \text{Relative corrected speed:} &amp;&amp; N_{cor,r} = \frac{\left(\frac{N}{\sqrt{T_{in}}}\right)}{\left(\frac{N_{d}}{\sqrt{T_{in,d}}}\right)} \end{align} where, $ \eta $ is the efficiency, $ N $ is the shaft speed, and $ PR = P_{in}/P_{out} $. Subscript $ cor $ denotes the corrected value, $ r $ denotes the relative value, $ in $ denotes the inlet, and $ out $ denotes the outlet.  \end{document}