SL Snoke looks like he has been around for a while, I am wondering where he was when the Empire ruled the Galaxy?   Did Darth Sidious and Darth Vader not sense his presence in the force?
In , DVK says:     Snoke ... we still have no idea who he is but he predates Galactic Empire...   Having seen the film twice, I can't remember how we would know that, I don't recall references to Snoke's age or past history. But  is knowledgeable about Star Wars in general, is there something that tells us this? In the film, or the novelisation, or...?
Does $x^2 - y^2 = 12345678$ (x,y are integers) have any solutions? Clipboard for copying and pasting files in command line? In Bash, suppose I visit a directory, and then another directory. I would like to copy a file from the first directory to the second directory, but without specifying the long pathnames of them. Is it possible?   My temporary solution is to use /tmp as a temporary place to store a copy of the file. cp myfile /tmp when I am in the first directory, and then cp /tmp/myfile . when I am in the second directory. But I may check if the file will overwrite anything in /tmp.  Is there something similar to a clipboard for copying and pasting a file? How to show that $f'(x)<2f(x)$ This is question B4 in 1999 Putnam Exam. I would appreciate if somebody could help me with this.      Let $f(x),f'(x),f''(x),f'''(x)&gt;0$ , $f'''(x)$ is a continuous function and $f'''(x)&lt;f(x)$ on $\mathbb{R}$. Then show that   $$f'(x)&lt;2f(x),~ \forall x\in \mathbb{R}.$$ Stack Overflow is getting a Meta of its own What is a referee in the manuscript submission process? Please submit, with the manuscript, the names, addresses (including   countries), and e-mail addresses of five potential referees who are   outside the authors' institutions and must not have conflict of   interest with the authors.   Do you think I should name 5 researchers from a similar area that are not affiliated with my university and co-authors? Is this what referees are? Let's say we have this code for a LWC:  &lt;!-- helloExpressions.html --&gt; &lt;template&gt;     &lt;div class="slds-m-around_medium"&gt;         &lt;lightning-input name='firstName' label="First Name" onchange={handleChange}&gt;&lt;/lightning-input&gt;         &lt;lightning-input name='lastName' label="Last Name" onchange={handleChange}&gt;&lt;/lightning-input&gt;         &lt;p class="slds-m-top_medium"&gt;Uppercased Full Name: {uppercasedFullName}&lt;/p&gt;     &lt;/div&gt; &lt;/template&gt;   and this is the JS file:  // helloExpressions.js import { LightningElement, track } from 'lwc';  export default class HelloExpressions extends LightningElement {     @track firstName = '';     @track lastName = '';      handleChange(event) {         const field = event.target.name;         if (field === 'firstName') {             this.firstName = event.target.value;         } else if (field === 'lastName') {             this.lastName = event.target.value;         }     }      get uppercasedFullName() {         return `${this.firstName} ${this.lastName}`.toUpperCase();     } }   firstName and lastName have been decorated with @track. Now as per the documentation, decorating a property with @track makes it private and reactive, while to mark a property public and reactive, use @api.  So if I just change the decorator to @api for both these variables, it should work. I am referring these from the same component only. But it's not working.  UPDATE: 27th Feb -------------------- Somehow it's working today. I just changed the decorator of the variables to api.  import { LightningElement, api } from 'lwc';  export default class HelloExpressions extends LightningElement {     @api firstName = '';     @api lastName = '';      handleChange(event) {         const field = event.target.name;         if (field === 'firstName') {             this.firstName = event.target.value;         } else if (field === 'lastName') {             this.lastName = event.target.value;         }     }      get uppercasedFullName() {         return `${this.firstName} ${this.lastName}`.toUpperCase();     } }   So it's working. I'm trying to make airsoft chronograph/chronometer (a device that measures airsoft bullet speed). The idea is to measure time in which bullet is traveling from point A to point B, and then I can calculate bullet speed. Bullet is shot into plastic pipe with diameter of 32mm. I've tried to put on one side IR LED and on the other side phototransistor (BPW 40), both at the start and end of the tube. Something like this:  Blue circles are phototransistors, red circles are IR LEDs and white circles are airsoft bullets. When bullet passes through area where bullet 2  is drawn (just in between IR LED and phototransistor), everyting works perfectly. But when the bullet passes where bullets 1 and 3 are drawn, it isn't detected. That is expected, but unwanted behavior. So my question is: how can I detect bullets regardlessly of it's position ? I've thought about putting IR LEDs and phototransistors around the pipe (not only in one place), like this:  but this solution isn't cheapest: 5 IR LEDs + 5 BPW 40 = cca $12 times 2 (because I need it on both sides of the pipe) = $24. Is there any cheaper solution ? Is BPW 40 good choice for phototransistor ? I don't know which IR LEDs I'm using (and salesman in the store also doesn't know - he told me these are generic ones for remote controllers, like TV or DVD controller). Diameter of the pipe is 32mm and it will be long about 14cm (sensors will be 10cm apart). Diameter of airsoft bullet is 6mm. EDIT: I'll go for my second idea. I just have one more question: is it better to arrange IR emitters and photo transistors this way:  or this way:  Thanks !! I'm starting to write a book on . Since I've been contributing on this tag for a long time, I had the opportunity to read &amp; answer several interesting threads on Stackoverflow related to this technology.  I would like to discuss some of the interesting cases published on Stackoverflow in my book, and I wonder if I could use the images and code shared on those threads in it.  I'm hoping somebody from StackExchange could clarify about the copyright status of the material shared on Stackoverflow questions/answers. I have had the last Ubuntu distro (10.something) installed for a year and love it.  But I have run in to an issue when I tried to upgrade it to the latest one it did not work and there has come some serious issues now with almost everything and I want to remove Ubuntu completely and install the new one.  How can I remove the operating system (I don’t mind formatting the whole thing if that’s what’s needed). Let $f:\mathbb{C} \rightarrow \mathbb{C}$ be a entire function. Suppose that there are $M$, $r&gt;0$ and $n\in \mathbb{N}$ such that $\left|f(z)\right|&lt;M\left|z\right|^n$ for all $z \in \mathbb{C}$ with $\left|z\right|\geq r$.  Show that $f$  polynomial of degree at most $n$.  Remark: I tried to follow the proof of Liuville's Theorem but I have complications with the condition  $\left|z\right|\geq r$.. If I want to use objects as the keys for a Dictionary, what methods will I need to override to make them compare in a specific way?  Say I have a a class which has properties:  class Foo {     public string Name { get; set; }     public int FooID { get; set; }      // elided }    And I want to create a:  Dictionary&lt;Foo, List&lt;Stuff&gt;&gt;   I want Foo objects with the same FooID to be considered the same group.  Which methods will I need to override in the Foo class?  To summarize: I want to categorize Stuff objects into lists, grouped by Foo objects. Stuff objects will have a FooID to link them to their category. How to merge partitions? I have two partitions, one of them has a file system and the other is unallocated.  How to merge two partitions? Degree of Field Extensions and $F(\alpha)$ Suppose that $[F(\alpha):F]$ is odd. Show that $F(\alpha)=F(\alpha^{2})$. Generalize this statement if possible.    Clearly, we always have that $F(\alpha^{2}) \subset F(\alpha)$ by definition of the field generated by $F$ and $\alpha$ (assuming that we have a field extension $K/F$ where $\alpha \in K$). However, how can we show the other inclusion? If the degree is odd, then it follows that $\alpha$ will solve a polynomial of odd degree in $K[x]$ (for the coefficients in $F$). What would be a way to proceed from here? (and as well to generalize the statement?)  I was thinking of using the formula: $[F(\alpha):F]=[F(\alpha):F(\alpha^{2})][F(\alpha^{2}):F]$ and maybe proceed from there.   Thanks for the help. SemanticImport vs Import differ on same CSV file? The Riemann zeta function $ζ(s)$ is defined for all complex numbers $s ≠ 1$ with a simple pole at $s = 1$. It has zeros at the negative even integers, i.e., at $s = −2, −4, −6, ...$.   My question: How one can obtain these roots. The system of equations Let $a,b,c\in \mathbb{R}$ that $a^{2}+b^{2}+c^{2}=1$. We want to find $x,y,z,w$ in the following equations:  $$\begin{align} x^{2}+y^{2}+z^{2}+w^{2}&amp;=1 \tag{1}\\ x^{2}+y^{2}-z^{2}-w^{2}&amp;=a \tag{2}\\ xw+yz&amp;=2b \tag{3}\\ yw-xz&amp;=2c.\tag{4} \end{align}$$ Why does $\sum_{k=1}^{\infty}\frac{{\sin(k)}}{k}={\frac{\pi-1}{2}}$? Inspired by  (and far more straightforward, I am guessing), Mathematica tells us that $$\sum_{k=1}^{\infty}\dfrac{{\sin(k)}}{k}$$ converges to $\dfrac{\pi-1}{2}$.   Presumably, this can be derived from the similarity of the Leibniz expansion of $\pi$ $$4\sum_{k=1}^{\infty}\dfrac{(-1)^{k+1}}{2k-1}$$to the expansion of $\sin(x)$ as $$\sum_{k=0}^{\infty}\dfrac{(-1)^k}{(2k+1)!}x^{2k+1},$$ but I can't see how...  Could someone please explain how $\dfrac{\pi-1}{2}$ is arrived at? Direct proof that nilpotent matrix has zero trace how to left justify comments to indent same as other text in Algorithmic How do I left justify my comments in the algorithm.  I am using algorithmicx package.  What I want is: to pull the comment to left as shown in the attached snapshot.  The code for my algorithm is       \documentclass[a4paper]{article}     \pagestyle{empty}     \usepackage{algorithm}     \usepackage{algpseudocode}     \usepackage[caption=false,font=footnotesize]{subfig}     \begin{document}     \begin{algorithm} \label{algoQ}     \caption{Algorithm to check quality of methods}     \begin{algorithmic}     \For{\textbf{each} $msd$ in$msdList$}  \Comment { \% for each MSD \%}     \Statex   \Comment { \% get MSDs referenced method service \%}     \EndFor \textbf{endFor}     \end{algorithmic}     \end{algorithm}     \end{document} How to prove this limit exists: $a_{n+2}=\sqrt{a_{n+1}}+\sqrt{a_{n}}$ Question: Consider a sequence $\{a_{n}\}$ such that $a_{1},a_{2}&gt;0$, and for all $n \in \mathbb{N}$ we have:  $$a_{n+2}=\sqrt{a_{n+1}}+\sqrt{a_{n}}$$  Prove that :  $\displaystyle\lim_{n\to\infty}a_{n}$ exists and find this limit.  My work: If this limit exists, let $\displaystyle\lim_{n\to\infty}a_{n}=x&gt;0$; then we have $$x=\sqrt{x}+\sqrt{x}\Longrightarrow x=4$$ But I can't see how to prove the limit of $\{a_{n}\}$ exists. Thank you for you help!