Deriving the Coulomb force equation from the idea of photon exchange?

Since Newton's law of gravitation can be gotten out of Einstein's field equatons as an approximation, I was wondering whether the same applies for the electromagnetic force being the exchange of photons. Is there an equation governing the force from the exchange of photons? Are there any links which would show how the Coulomb force comes out of the equations for photon exchange? I know that my question is somewhat similar to the one posted here , but it doesn't really have an answer to my question specifically.


What word means "the feeling of discomfort caused by watching people's ineptitude"?

I am watching a UK TV programme called "The Apprentice".  The candidates have to sell guided tours.  Some candidates are terrible at giving these tours.  They fluff their lines, or they haven't researched, or they make up "facts".  Watching their ineptitude cause a feeling of discomfort.  What is the best word for this discomfort?  The German word schadenfreude means roughly "the pleasure derived from the misfortunes of others".  The word I want would be almost an antonym of schadenfreude - "the discomfort derived from the mosfortunes of others".  Except not the misfortunes but the uselessness of others.


Why don't shell builtins have proper man pages?

All shell builtins share the same manual page:  BUILTIN(1)                BSD General Commands Manual               BUILTIN(1)  NAME      builtin, !   etc.   Then there is a little text describing what shell builtins are, and then a list that  looks something like this:    Command       External    csh(1)    sh(1)        !             No          No        Yes        %             No          Yes       No   But if we do man grep we get sections such as   Bugs History See also Standards Description   etc.  Don't shell builtins have their own history, description and arguments like -A or -r? Why isn't that provided in the manual pages and how would I learn to use them correctly and efficiently?


A Christmas puzzle: $n$ children in a row identifying the colors of their hats

$n$ children are placed in a row from north to south such that all of them look at north; i.e., every child does only see the children before him. After being placed in the row, they aren't allow to move or communicate in any form possible. Every child will have a random bobble hat marked with a color in $0, \dots, k$, with $k \leq n - 1$ on his head. Noone knows which color its hat has, and noone is allowed to look after. After all children have their hats, they shall say which color his hat has. They are only allowed to say "color $i$". If more than one child will say the wrong color, no one gets a present. What is the winning strategy for the children?  I think it could have something to do with the . Otherwise, I can only imagine to speak rhythmically to encode the number of combination, but that seems not to be intended.


Why does | bitwise OR operator evaluate both sides when 1 is found in first side?

definition is      returns a zero in each bit position for which the corresponding bits of both operands are zero   So it returns a one otherwise. Basically this means that 1 | 0 is 1.  Behaves much like ||, which returns true if one side is true.  However, we know that ||, in case left side expression is true, stops at that and won't evaluate right side expression, because no matter what, the result will be true.  This means that   var a = 0, b = 0; function incrementAAndReturnTrue(){   a++;   return true; }  function incrementBAndReturnFalse(){   b++;   return false; }  incrementAAndReturnTrue() || incrementBAndReturnFalse(); console.log(a); // 1 console.log(b); // 0   However, for bitwise OR operator, both sides are evaluated, no matter what.  var a = 0, b = 0; function incrementAAndReturnOne(){   a++;   return 1; }  function incrementBAndReturnTwo(){   b++;   return 0; }  incrementAAndReturnOne() | incrementBAndReturnTwo(); console.log(a); // 1 console.log(b); // I expected 0, but it's 1   Why is that the case?


what form of grammar is the word "why" used as a pause?

In this sentence:     If you're going to take that pie I just baked, why, you've got a lot of nerve.   what role does the word "why" take? I know I've heard it in conversational speech enough to know it's legitimate, but it looks really odd in print.


I am using the above function to add paragraphs(it works fine). I want to use this event to remove something onclick, but it doesn't run at all. Thank you!  function add() {   text = $('.textfield').val();   $('.list').append('
' + text + '
');   $('.textfield').val(''); }  $('.target').click(function(){         $(this).remove(); });


I have two tables .  1-> SM_Employee       (1) employeeid     (2) roleid  (3) storeid    2-> SM_SalesRepWorkflow    (1) workflowid  (2) Salesrepid   foreign key to employeeid  (3) QuantityAssigned  (4) QuantityLeft  (5) month   (6) year    By these tables I need to select first row of every SalesRep Details from   SM_SalesRepWorkflow order by SalesRepId for CurrentMonth and CurrentYear.  Example  Workflowid   SalesRepId  QuantityAssigned  QuantityLeft  Month  Year     WF_101   :   EMP_101  :      100        :     90      :   May :   2013   WF_101   :   EMP_102  :      100        :     100     :   May :   2013   WF_101   :   EMP_103  :      100        :     80      :   May :   2013   WF_102   :   EMP_101  :      100        :     70      :   May :   2013     So result i want is      WF_101   :   EMP_101  :      100        :     90      :   May :   2013   WF_101   :   EMP_102  :      100        :     100     :   May :   2013   WF_101   :   EMP_103  :      100        :     80      :   May :   2013     So There can be many Workflow for a SalesRep.  But i want the first one for every SalesRep for current month and year.


How to prove this condition if three vectors are colinear?

So I was given this problem:     Let $\vec{a} = \begin{pmatrix}x_a\\y_a\\z_a\end{pmatrix}$, $\vec{b} = \begin{pmatrix}x_b\\y_b\\z_b\end{pmatrix}$, and $\vec{c} = \begin{pmatrix}x_c\\y_c\\z_c\end{pmatrix}$.   Show that $(x_a,y_a,z_a)$, $(x_b,y_b,z_b)$, and $(x_c,y_c,z_c)$ are collinear if and only if   $$\vec{a} \times \vec{b} + \vec{b} \times \vec{c} + \vec{c} \times \vec{a} = \mathbf{0}.$$   I tried plugging it in and it looks like it is true:     Let $\vec{a} = \begin{pmatrix}2\\4\\6\end{pmatrix}$, $\vec{b} = \begin{pmatrix}4\\8\\12\end{pmatrix}$, and $\vec{c} = \begin{pmatrix}8\\16\\24\end{pmatrix}$.   $$\vec{a} \times \vec{b} + \vec{b} \times \vec{c} + \vec{c} \times \vec{a} =\begin{pmatrix}0\\0\\0\end{pmatrix}  +\begin{pmatrix}0\\0\\0\end{pmatrix}  +\begin{pmatrix}0\\0\\0\end{pmatrix}\\ = \begin{pmatrix}0\\0\\0\end{pmatrix}\\ $$   How could I prove this to be true? I am not entirely sure where to begin.


finding all numbers $a,b$ that divide $c$ but product of $a$ and $b$ does not divide $c$

Let $a,b,c\in \mathbb{Z}$, such that $a$ and $b$ are relatively prime, and both $a$ and $b$ divide $c$. Prove that in this case $ab$ divides $c$. Find all numbers such that $a$ and $b$ divide $c$ but $ab$ does not.  I proved the first part easily. For the second part, is the answer that any two $a,b\in \mathbb{Z}$ which are not relatively prime, their product will not divide $c$?


Someone at my company created a regex string that is working as intended but I want to do similar things in the future and don't understand the mechanics of it.   import re  config = """ interface Ethernet1/2  description Management  ip address 192.168.1.190 255.255.255.0  ip pim sparse-dense-mode ! interface Ethernet1/3  description to-IntDMVPN  ip address 10.0.0.93 255.255.255.252  ip pim sparse-dense-mode ! router eigrp 1  network 172.16.0.0 0.0.0.255  redistribute ospf 1 metric 1 1 1 1 1 ! """  intf_obj_list = re.compile(r'^interface\s*(\S+)(.+?)(?:^\S+|\Z)', re.S|re.M).findall(config)  print(str(intf_obj_list))   I understand up to ^interface\s*(\S+) which matches the router interfaces but adding the (.+?) also matches the /n on the first line of each interface config even though the dot is supposed to match any character but the newline.  Now (?:^\S+|\Z) adds matching of the body of the configuration under the interface and I don't understand that section at all.  From what I could find ?: is another way to configure backreferencing which after a fair amount of googling, I'm still not clear on and I'm not sure what the ^\S+|\Z within it are accomplishing.  Finally, the re.S I think allows it to continue to run through the body while encountering newlines and re.M allows it to run through multiple lines. If anyone can help me to break down what's happening here I would greatly appreciate it.  Thanks


How to change hostname on a ubuntu server 18.04

I have a problem with a new server with Ubuntu 18.04.  I try to change the host name more times, with different method, like editing /etc/hostname or hostnamectl --set-hostname ecc ecc. But when I reboot the machine the host name return to old setting. Can you help me?  I've a host with incorrect name like:     root@viper:~# cat /etc/hostname     viper    I tried to change hostname:    root@viper:~# hostnamectl set-hostname titan --static    But when I reboot the host the hostname return back to viper.   I also try to edit, with vi/nano the file /etc/hostname and /etc/hosts changing viper to titan.   It'works for current session, but when I reboot the hostname return viper :(   Maybe I'was not clear. The problem is not how to change the hostname, but how to make it persistent. The filesystem is not readonly I'm sure:    /dev/sda2 on / type ext4 (rw,relatime,data=ordered)


Can creatures use the Attack action without attacking?

Suppose a creature gets some benefits when they take the Attack action. For example, the Horizon Walker ranger's Distant Strike lets them teleport at will, but only when they take the Attack action.  Could a creature take the Attack action and gain those benefits, without making attack rolls or otherwise targeting a creature (e.g. grappling and shoving)?  Could they "attack" an empty space, as though trying to hit an unseen enemy (even if they don't suspect an enemy is there)?  Note that I am asking about the general case, whether any and/or all creatures can do this, regardless of class or special features.    Inspired by this question:


How does one find any polynomials common roots

I was wondering if there was a way to find the common roots of 2 polynomials.  For example let $P_1(x) = x^5+x^3+2x^4-5x^2-7$ and $P_2(x) = 2x^7 +3x^3+4x^6+6x^2-14x^4-21$  Is there an algorithm or a method to find $P_1$ and $P_2$'s common roots?


How to change the behavior of OS X to when working with multiple applications?

The biggest problem with OS X that bothers me a lot is that when you are working with multiple applications and trying to switch between applications with mouse: first you have to click on the application and then start using it.  As an example, let's say we have two text editors that we are typing in each of them separately. Now lets say we want to copy a piece of text from first window to the second one. Based on OS X's behavioral semantics, you have to select the first window with a mouse click and then again press the mouse click to select a piece of text. This sometimes brings down my productivity by a lot in different applications.  In Microsoft Windows applications, there is no such concept. For the same scenario, if you click on some text on the a un-selected window, it will instantly start selecting the text without the need for selecting the application first. This is only one simple example.  The question is, is there anyway to enable a feature like this in OS X?


If $|f|+|g|$ is constant on $D,$ prove that holomorphic functions $f,~g$ are constant on $D$.

Let $D\subseteq \mathbb{C}$ be open and connected and    $f,~g:D \rightarrow \mathbb{C}$ holomorphic functions such that    $|f|+|g|$ is constant on $D.$ Prove that $f,~g$ are constant on $D.$   Attempt. I noticed first that this problem is already set before, and is considered  to be duplicate () and we are sent directly to problem . However, the last reference deals with the sum $|f|^2+|g|^2$, which I do not see how is connected to the sum $|f|+|g|$, as stated in our title (for example, the equality $|f|^2+|g|^2=(|f|+|g|)^2-2|f||g|$ is not helpful here).  Thanks in advance!


$\det\left[ \begin{matrix} A & B \\ B & A \end{matrix} \right] \ = \ \det\left( A + B \right) \det( A - B )$ for $AB \neq BA$

For two square matrices $A$ and $B$ of the same size, we have the identity $$ \det\left[ \begin{matrix} A & B \\ B & A \end{matrix} \right] \ = \ \det\left( A + B \right) \det( A - B ) \ . $$ This is supposed to hold even when the matrices are non-commuting ie. $A B \neq BA$. In the case that $AB=BA$, I can see how the above follows from the identity $$ \det\left[ \begin{matrix} A & B \\ C & D \end{matrix} \right] \ = \ \det(D) \det\left( A - B D^{-1} C \right) $$ by taking $(C,D) \to (B,A)$ and mutiplying the argument of the determinants together, leads to $$ \det\left[ \begin{matrix} A & B \\ C & D \end{matrix} \right] \ \to \ \det(A) \det\left( A - B A^{-1} B \right) = \det\left( A^2 - B A^{-1} B A \right) = \det\left( A^2 - B^2 \right) =  \det\left( A - B \right)\det\left( A + B \right) $$ but the above proof relies heavily on $AB=BA$. How do you see this identity is true in the case that $AB\neq BA$?


There has been very strange bug in every version on of Windows from 7 to 10 (Windows 7/8/8.1/10). I have been trying to google it for seven years without success because I don't know how to explain it shortly. So now I will try my best to explain it. The problem is about taskbar icons (from this point I will call this bug "the problem"). It happens once or twice a month and it is resolved after restarting Windows but it is still very annoying. Normally taskbar icons are highlighted when you hover mouse pointer above them. But when this problem happens the last icon you hover stays highlighted until you hover mouse above another icon. There is also another problem. Normally when you hover mouse above the taskbar icon which belongs to currently opened application, after some time application window preview shows up and disappears shortly after you move away mouse from it. But when the problem happens the preview appears instantly and stays even after you move away pointer from application taskbar icon. The preview stays until you move mouse above another icon and the problem continues till restarting Windows. So that's it. I'm not very good at explaining things so that's was the best I could do. Feel free to ask anything in comments to clarify things. To be clear I have never used any third party theme app or anything like it. Because this bug was in all versions of Windows I have used and also I have never seen it on other computera or even heard of it, one might think that problem is with my hardware, so here are some of my laptops specs:  Current Operating System: Windows 10 Pro 64-bit  CPU: AMD E-450, Zacate 40nm Technology  RAM: 4.00GB DDR3 @ 665MHz (9-9-9-24)  Motherboard: ASUSTeK Computer Inc. K53BR (CPU 1)  Graphics:  Generic PnP Monitor (1366x768@60Hz)  384MB ATI AMD Radeon HD 6320 Graphics (ASUStek Computer Inc)  1024MB ATI AMD Radeon HD 7400M Series (ASUStek Computer Inc)  CrossFire Disabled   Storage: 298GB Western Digital WDC WD3200BPVT-80JJ5T0 (SATA)  Optical Drives: HL-DT-ST DVDRAM GT51N  So my questions are:  1) Is anybody there who has the same problem or has even heard of it?  2) Is it possible to fix it?


How To Debug Override finalize() Method In Java?

As we know about this like...     The java.lang.Object.finalize() is called by the garbage collector on   an object when garbage collection determines that there are no more   references to the object. A subclass overrides the finalize method to   dispose of system resources or to perform other cleanup. Also The finailze()    method should be overridden for an object to include the clean up code   or to dispose of the system resources that should to be done before   the object is garbage collected.   So I created a class and override finalize() method in it with some of mine code as shown below as my main concept is to write all the data that my class contain in the end like before closing the form in a text file to save it...  public class MainClass {     public static void main(String[] args) {         NewDEMOClass obj = new NewDEMOClass();         obj.AddValueToMap("A",1);         obj.AddValueToMap("B",2);         obj.AddValueToMap("C",3);         // Many Value Added Here...              }     }   Then my custom class is...  public class NewDEMOClass {     private Map<String, Integer> customDictionary = new HashMap<String, Integer>();      public NewDEMOClass()     {         }      public AddValueToMap(String Key, Integer Value)     {            customDictionary.put(Key, Value);     }                 @Override     protected void finalize()     {         String totalWord = "";         for ( Map.Entry<String, Integer> entry : customDictionary.entrySet() ) {             totalWord += entry.getKey() + "-" + entry.getValue() + System.lineSeparator();         }         while (true)         {             try(                 PrintWriter out = new PrintWriter("customDictionary.txt", "UTF-8")  ){                 out.println( totalWord );                 break;             } catch (FileNotFoundException ex) {                 Logger.getLogger(AutoUrduPredictorAndSuggester.class.getName()).log(Level.SEVERE, null, ex);             } catch (UnsupportedEncodingException ex) {                 Logger.getLogger(AutoUrduPredictorAndSuggester.class.getName()).log(Level.SEVERE, null, ex);             }         }     } }   So my main problem and question is that I want to debug finalize() method inner codes line by line to see the errors and etc But I am not able to add breakpoint as I am using NetBeans IDE. So What to do now and How...???


Explicit bijection $f:\Bbb R\times\Bbb R\to\Bbb R$

I am right now preparing for a set theory exam and found one exercise in an old exam which I was not really able to solve in the intended way. The task was the following:     Define an explicit bijection $f:\Bbb R\times\Bbb R\to\Bbb R$    I know that     $\vert\Bbb R\times\Bbb R\vert = \vert 2^{\Bbb N}\times 2^{\Bbb N}\vert = \vert 2^{A\cup B} \vert = \vert 2^{\Bbb N}\vert = \vert\Bbb R\vert$ with A, B disjoint countable sets   and you can probably get a bijective function by going over these steps and link the functions afterwards but I would be very glad for a help with a more direct approach.


From its definition a combination $\binom{n}{k}$, is the number of distinct subsets of size $k$ from a set of $n$ elements.  This is clearly an integer, however I was curious as to why the expression  $$\frac{n!}{k!(n-k)!}$$ always evaluates to an integer.  So far I figured:  $n!$, is clearly divisible by $k!$, and $(n-k)!$, individually, but I could not seem to make the jump to proof that that $n!$ is divisible by their product.


Integrate $\frac{dx}{x^{2n}+1}$ for $n \in \mathbb{N}$ from $-\infty$ to $\infty$

How can one calculate   $$ \int_{- \infty}^{\infty} \frac{dx}{x^{2n} + 1}, \;n \in \mathbb{N} $$  without using complex plane and Residue theorem?


E149: Sorry, no help for XXX (no help in vim)

Running ubuntu 20.10 and vim: version 8.2.716  that comes default with installation. Seems the help function in Vim does not work/exists: :help cp-default                                                                    E149: Sorry, no help for cp-default  or: :help cp E149: Sorry, no help for cp  Do I need to install some additional help files to enable it?


Can I do anything if I don't agree with migration to another site?

Yesterday I asked this question on SO,  and soon after it was closed as off-topic and migrated to Programmers (the history is here, ).  I don't see anything wrong with that question and I sincerely believe this tag and migration was just plain wrong. The explanation - "Without a language tag or some example code, it's not going to get much attention here." is meaningless, since most of design-related questions on SO is without language tag and/or example code. Also number of DDD-related questions on SO is way higher than on Programmers (there are only 191 questions tagged with DDD on Programmers). If I believe that it wasn't fair, can I do something about that?  And in general - if I believe that someone did something wrong, can I challenge it?  P.S. I'm new to meta, I'm not sure if my nagging belongs here, but I'd like to know what's wrong; I did search first and I couldn't find anything that answered my question.


Short story I read online about woman who lives in a society where no one ages and eventually she leaves her body to explore the universe

This was a short story I read in the early 2000's.  The main character is a woman and it starts off talking about her life and her husband/boyfriend who ends up passing away.  She ends up taking a new pill that stops people's aging completely.  The entire world no longer ages and as centuries go by, they no longer need their physical bodies and can choose to leave their bodies behind and explore the universe as a type of energy.  The woman chooses that path and the story is really about the experience of living "forever" and transcending into a purely mental/energy state.  If anyone has any leads I would very much appreciate it.  I read this story over ten years ago and have never forgotten it.


C++ public/private static variable not seen by linker

I am away from home using my notebook. I have installed Microsoft VS Community 2015 and Microsoft VS 2013 Express. I get the same error on both IDEs. I have tried both qualifying "++GlobalLineCount::glCount" and unqualifying "++glCount". I have retyped the text in case of some unseen character. I am not using precompiled headers. I have tried glCount both as pubic and private. This is pure C++. This code fails as is. It is an extraction of a larger program that also fails with the same error. The larger program does compile and link on my home PC using Microsoft VS Community 2015. Because the larger program behaves correctly on my home PC but not on this notebook I am suspicious of the IDE installed or configuration. Currently, I am 1500 miles from my home PC so doing anything with it is not possible. Thanks in advance.  My error:  TestGlobalLineCount.obj : error LNK2001: unresolved external symbol "public: static unsigned __int64 GlobalLineCount::glCount" (?glCount@GlobalLineCount@@2_KA)  My code:  #include <stdint.h> #include <stdio.h> #define MODULE_WHO_AM_I "TGLC" class GlobalLineCount { public:     static uint64_t getNextGLC(void)         { return ++GlobalLineCount::glCount; }      static uint64_t glCount; }; int main() {     printf("%-5s %4d %6llu - Test Start\n",         MODULE_WHO_AM_I, __LINE__, GlobalLineCount::getNextGLC());     return 0; }


Why doesn't UX Stack Exchange have a mobile app for iOS and Android to broaden audience

This may be marked down at an astronomical rate - but here goes...  I find myself viewing UX stack exchange quite regularly on my iOS device, when on the go and thinking a downloadable app would be of benefit for 'widening the net' of users who want to access the forum ad-hoc from anywhere, thus increasing the chances of askers getting the very best answers in return, Transparent benefits would include faster access and a broader audience.  This is not opinion based, but more can see potential benefits fomr this being developed, thoughts welcome!


How to use Rolle's Theorem to show that $f$ has at most one fixed point? NOT DUPLICATE

Let $a,b \in \mathbb{R}$ be such that $a\lt b $. Suppose that $f:[a,b]→\mathbb{R}$ is a continuous function on $[a,b]$ and is differentiable on $(a,b)$ and that   $f'(x) \gt 1$ , for all $x\in(a,b)$.  Use Rolle's Theorem to show that $f$ has at most one fixed point in (a,b), that is a point $x_o\in(a,b)$ such that $f(x_0)=x_0$.  Hint: You may find it helpful to argue using proof by contradiction.  My solution so far:   Rolle's Theorem states that if $f$ is a continuous function on $[a,b]$ and is differentiable on $(a,b)$ and that $f(a)=f(b)$, then there is a point $c\in(a,b)$ such that $f'(c)=0$.  Assume for a contradiction, there are two fixed points in $(a,b)$, that is, $x_0,x_1\in(a,b)$ such that $f(x_0)=x_0$ and $f(x_1)=x_1$.   Now, I don't know how to proceed from this because $f(x_0)\ne f(x_1)$, so surely you can't apply Rolle's Theorem here.  Note: This is not a duplicate question as this question explicitly asks to use Rolle's Theorem.


Why is the sizeof a class with no non-static members always 1?

Normally, if a class has other non-static members, the size of static variables do not count towards the size of the class (or struct). For example,  struct A {    float f1;    float f2;    double d1; };   This struct would be 4 + 4 + 8 = 16 bytes (on an x86 PC).   struct A {    float f1;    float f2;    static double d1; };   Making the double d1 static would reduce it to 8 bytes.   However if I make all three members static, the size comes out to be 1. Why is that? In fact, removing all the variables has the same effect.  Someone told me it was because the object needs to keep track of its address, but an address is 4 bytes long isn't it? What's more, why isn't this 1 byte added to the size when I have non-static member variables? What is the purpose of this one byte if there are no non-static member variables or virtual functions?


One of my cites shows with first name initial for some reason?

My cites are showing Surname, year as expected.. Except this one:  @article{wang2013genome,    title={Genome-wide transcript analysis of early maize leaf development reveals gene cohorts associated with the differentiation of C4 Kranz anatomy},    author={Wang, Peng and Kelly, Steven and Fouracre, Jim P. and Langdale, Jane A.},    journal={The Plant Journal},    volume={75},    number={4},    pages={656--670},    year={2013},    publisher={Wiley Online Library} }   That shows as "(P. Wang et al. 2013)" instead of "(Wang et al. 2013)".  I have noticed that if I change the name from Wang to Aang it correctly prints "(Aang et al. 2013)". But that's obviously not the correct name. What is happening and how can I fix it?  This is what I am using:  \usepackage[backend=biber,style=authoryear,bibstyle=authoryear,maxbibnames=99,maxcitenames=2,firstinits=true,uniquename=init,uniquelist=minyear]{biblatex}


Silver Bracelet Photography with 100% pure white Background

i am selling Bracelet in Amazon and i am facing hard time taking white back photography for silver bracelets. The following image is from another seller. This is the quality i needed.    But all i getting is these...    This too after editing with photoshop (I crease brightness which compromises the bracelet quality).   I have DSLR camera. I tried using different backgrounds like paper, boards, cloth, etc., But nothing seems to work for me.   Can anyone please help me how to achieve 100% pure white background without compromising quality?


Is work done on a system always the negative of the work done by the system?

Consider the following situation. A block slides on a rough surface. We have already given it an initial velocity. I consider my system to include only the block. Due to friction, the table performs work on the block, thereby reducing its kinetic energy. On the other hand, the block performs no work on the table, since the table surface does not get displaced at all. So, isn't it incorrect to say that work done on the system is the negative of the work done by the system?  If the work done by a system is not always the negative of the work done by the system, then how can both versions of the first law of thermodynamics hold true? The first law of thermodynamics in the physics point of view is: $\Delta U=Q-W,$ and in the chemistry perspective is: $\Delta U=Q+W.$  Both of these seem to be correct, as in the first case we are considering the work done by the system on the surroundings, and in the second case we are considering the work done on the system by external forces. But, if the work done by a system is not equal to the negative of the work done on it, then I have a feeling that the chemistry definition might be a better one. Please clarify.  Kindly note that I am already aware of the different conventions  used in physics and chemistry, and I completely understand their intended meanings. My question is not really related to thermodynamics, but something more fundamental. I have just taken the first law of thermodynamics as an example.


Not able to install nodejs in ubuntu command line

I have tried this: sudo apt install nodejs  Getting Error this:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  nodejs : Depends: python-minimal but it is not going to be installed E: Unable to correct problems, you have held broken packages.


Limit of a sequence involving root of a factorial: $\lim_{n \to \infty} \frac{n}{ \sqrt [n]{n!}}$

I need to check if $$\lim_{n \to \infty} \frac{n}{ \sqrt [n]{n!}}$$ converges or not. Additionally, I wanted to show that the sequence is monotonically increasing in n and so limit exists. Any help is appreciated. I had tried taking log and manipulating the sequence but I could not prove monotonicity this way.


Cannot mount NTFS partition in Ubuntu 13.04

After I installed Ubuntu 13.04, I can't mount my NTFS partition.  Error mounting /dev/sda5 at /media/mrxfly/xFLyDiskData: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda5" "/media/mrxfly/xFLyDiskData"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda5': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.


I have to setup logs in sftp, I found out some link online and i made the following changes in sshd.conf  Subsystem   sftp    internal-sftp -l info   and after that i restarted sshd services.   still there is no detailed entry for file upload and delete, only opne connections and close connection   Feb 13 14:12:31 ip-172-31-51-97 systemd[1]: Created slice User Slice of ubuntu. Feb 13 14:12:31 ip-172-31-51-97 systemd[1]: Starting User Manager for UID 1000... Feb 13 14:12:31 ip-172-31-51-97 systemd[1]: Started Session 736 of user ubuntu.   Machine is an ubuntu 16 instance in Amazon


Here are my constructions:        Only minimal signs of corrosion on the vehicle body surface which have been removed.   Only minimal signs of corrosion on the vehicle's body surface which have been removed.      So my question is, should I use 'vehicle body' or 'vehicle's body'?


Element created out of a jquery each wont ''acept'' click event

im creating a list of links out of an AJAX call that will do a $.each and append elements to a div. In terms of design everything is fine but as you can see im creating a favorite script with that . When i click that  nothign happens, i tried to put a z-index:100 and still nothing it wont trigger the click(). I did it in HTML and it worked but when i switched it to the $.each it stopped working. $.ajax({             method: 'post',             url: myurl,             data: {obj},             dataType: 'json',             complete: function (data) {                 if (data.responseJSON != 'fail' && data.responseJSON) {                      $.each(data.responseJSON, function (index, value) {                         $('#'+id).append('' +                             '
\n' +                             '       '+value[4]+'\n' +                             '       \n' +                             '
'                         );                     });             }         });


Find $n$ such that polynomial is divisible

Find $n \in N$, such that: $$(x^2+x+1)^2 | x^n+(x+1)^n+1 = P(x)$$  If I let $Q(x) = x^2 + x + 1$, I have that $x^3 \equiv 1$ mod$Q(x)$, so I can work out the cases for remainder of $n$ when divided by $3$ .. But what to do next, because I need $Q^2(x)$ dividing $P(x)$ ? I suppose this could be done with complex zeroes, but is there a faster way ?


In a line up of 10 soldiers, what is the maximum number of soldiers that can be picked in order of either ascending or descending heights? Assume that no two soldiers have the same height. Soldiers can be picked from anywhere in the line, but their order of standing cannot be changed.  In other words, we want to find the maximum number k such that, for any permutation of 10 elements, we can always either find an increasing subsequence of length k, or a decreasing subsequence of length k.


I don't even know where to begin... [Installing Node]

I saw this video here    And I wanted to follow it to create my own HourBoost bot. So I purchased a £3 Ubuntu VPS from OVH and tried to follow his video directly and it doesn't work. I am beyond confused as he is using the full OS and mine is just the terminal. I am extremely new to this so I don't even know where I have gone wrong.  So far I'm here    Could anyone take the time to help me?  I don't think its that complicated considering the video is only 5 minutes.


In any finite group $G$, the number of elements not equal to their own inverse is an even number. I'm not sure how to go about this. I was considering assuming the number of elements not equal to their own inverse is an odd number (contradiction), but I'm not sure how to get a contradiction. I was considering thinking about when $|G|$ has even order and odd order, and then finding a way to do it directly, but I'm not sure. I think that in a finite group the number of elements equal to their own inverse should be even since they come in pairs. Any hints or solutions are greatly appreciated.


Make an element minus the height of another element in css without display flex. Because flex is a new thing, it is not supported in some browsers which is worrying. So I have two elements:
 hello there
some text

 hi there
this is some more text
to make this thing more lengthy
  So, because of the text inside #example2, if #example2 is for example: 100px in height, I want to make the div #example1: 100% of page height minus the height of #example2, 100% - height@#example2 Edit: If there is no way without flex, let me know.


When I make long copy operations (which usually is to USB-flash memories), the progress window often disappears completely if I put it out of focus. I have tried some hints using alt/tab and wmctrl, but I can't get the progress window back.  I can see a very small grey bar on top of the corresponding launcher icon. But there is no way to terminate the copy operation or to see details.  Can I bring the copy progress window back somehow?  I use v 16.04 default setup. (I hope it is correct to use the Nautilus tag.)


Problem with understanding Cantor's diagonal argument

As shown in , we make an assumption that the list of infinite sequences of binary digits is countable. After writing an enumeration, we complemented the diagonal elements to produce an element which isn't in the enumerated list. If the number $s$ is made up from complementing the digits of $s_i$ for $i=1,2,...,n$, then it is guaranteed that it is not one of the $s_i$s by construction. My problem is how do we know that it isn't one of the $s_j$s for $i=n+1,n+2,...$. The enumeration doesn't afterall stop at n---It goes like---${s_1,s_2,s_3,...,s_n,s_{n+1},s_{n+2},...}$. So our specially constructed $s$ can(infact must) fall in the list though it doesn't fall in the first $n \hspace{0.1cm}s_i$s. Contrastingly consider the proof that the rationals are countable, we construct a similar table(by dividing the row and column number of that table), at any step we can construct a rational which is not in that table by choosing a bigger row and or or a bigger column number, so we made a number which wasn't in the list but we don't say then that the set of rationals is uncountable. (Instead it is said we can make any rational number $c/r$ in finite number of steps.) Note that I have no problem in accepting the fact that the set of reals is uncountable (By Cantor's first argument), it is the diagonal argument which I don't understand. Also I think, this shouldn't be considered an off-topic question although it seems that multiple questions have been asked altogether but these questions are too much related and useful in drawing the (wrong)contradiction to Cantor's argument, so they have been asked. I have seen similar understanding problems with Cantor's diagonal argument in MSE but none match mine(probably) so this isn't a duplicate as well. If you think I missed some, please kindly comment down the link and I will have a look.


How Do I Plot a Nonlinear Decision Boundary?

I finished training my Sci-Kit Learn Logistic Regression model and it is performing at 100% accuracy. However, when I went to plot the decision boundary, I got a bit confused. I am not running the typical Logistic Regression model. Instead, I have transformed the elements of the input feature matrix into nonlinear 2nd degree polynomial terms before training with the help of Sci-Kit Learn's sklearn.preprocessing.PolynomialFeatures(degree = 2) function. According to the documentation, this function transforms two features $[x,y]$ to six features $[1,x,y,x^2,xy,y^2]$. With this in mind, I wrote the general equation of the decision boundary like this: $\theta _0x^0+\theta _1x^1+\theta_2y^1+\theta_3x^2+\theta_4x^1y^1+\theta_5y^2+b=0$, while obtaining all the $\theta$ parameters from model.coef_[0][0] for $\theta_0$, model.coef_[0][1] for $\theta_1$, model.coef_[0][2] for $\theta_2$ (and so on), and the $b$ parameter from model.intercept_[0]. When I plotted this on Desmos, it came up with a weird plot nothing close to a rational decision boundary. My question: does the method model.coef_ return the parameters $\theta_0$ to $\theta_5$, IN THAT ORDER? For example, if it returns [a, b, c, d, e, f], does that mean $\theta_0$ is equal to a, $\theta_1$ is equal to b, $\theta_2$ is equal to c and so on?


Can no longer boot into ubuntu after updating

I have had my machine dual booting windows 10 and ubuntu 16.04 for many years using grub2. I havent been using ubuntu in awhile and have just logged back in. I had quite a lot of updates to do. Once I updated it told me I needed to restart to use the new version, I think it was a kernel update. I tried to reboot but I just get a black screen with a single line of green pixels going across the top of my monitor, no grub boot loader. I can go into the bios and boot directly to windows 10 fine. But when I try ubuntu I just get the same black screen with the green line. I decided to install ubuntu 18.04 from a live usb which was my original plan. On installation I told it to erase 16.04 and use that partition. It installed fine but I get the same problem with the black screen and green pixel line.  Windows an Ubuntu are on the same disk just different partitions. I have uefi  Any suggessions?


Can you re-equip equipment to the same creature?

has an equip cost: discard a card, and since madness runs off discarding, this can be rather useful. Can an equipment card be re-equipped to the same creature that already has it equipped?


Search for existing questions asked by someone else

Please add the search feature for the existing questions asked by someone else, which the current user is going to ask. How to see the answers to my questions if the same is asked and answered previously by someone else?


When does the item count reset for the Puzzle Ring?

I have the Puzzle Ring in Diablo 3 which means that I have a cute little treasure goblin that runs around with me. He picks up and eats all the white items that I find and after a certain number (for me, it's 12 but I believe it varies) he poops out a rare or legendary item.   Depending on what I'm doing in the game, it seems like the item count resets differently. So what causes the item count to reset on the puzzle ring? Is it different depending on what you're doing - like regular game versus Rift?


Create a method call in .NET based on a string value

Right now, I have code that looks something like this:  Private Sub ShowReport(ByVal reportName As String)     Select Case reportName         Case "Security"             Me.ShowSecurityReport()         Case "Configuration"             Me.ShowConfigurationReport()         Case "RoleUsers"             Me.ShowRoleUsersReport()         Case Else             pnlMessage.Visible = True             litMessage.Text = "The report name """ + reportName + """ is invalid."     End Select End Sub   Is there any way to create code that would use my method naming conventions to simplify things?  Here's some pseudocode that describes what I'm looking for:  Private Sub ShowReport(ByVal reportName As String)     Try         Call("Show" + reportName + "Report")     Catch ex As Exception         'method not found     End Try End Sub


What justifications have been given for using particular systems of logical calculus?

I think that using any particular system of logical calculus should be properly justified.   This justification should be seen as particularly important and pressing in science and technology, and possibly elsewhere, such as in strategic and geopolitical studies. Since mathematics is fundamental at least to science and to technology, such a justification should be produced in mathematics as well.   I also think that this justication can only be achieved on the basis, somehow, of the way we think, i.e. what I would call our sense of logic. What do you think are the most effective justifications produced so far, if any, and why do you see them as effective?


Encoding problem with accents and special chars

I'm experiencing serious problems with accents (é, í, ú...) & special chars (like "ñ" or "¿") replaced by strange characters in content and menus.   The site is in spanish. I use Wordpress. Never migrated. The problem appears using PHP 7.1, 7.2 and 7.3. If I back to PHP 7.0 everything is perfect. I did many tests in staging environment with no plugins and default WP theme, but no results.     FYI these are my data:  Wp-config: define('DB_CHARSET', 'utf8mb4');  define('DB_COLLATE', '');  All the tables in PHPMyAdmin are utf8mb4_unicode_ci except Yoast tables that are in utf8_general_ci…   character_set_client: utf8mb4 character_set_connection: utf8mb4 character_set_database: utf8 character_set_filesystem: binary character_set_results: utf8mb4 character_set_server: utf8 character_set_system: utf8 collation_connection: utf8mb4_unicode_ci  collation_database: utf8_general_ci collation_server: utf8_general_ci     Is it a problem with 'DB-CHARSET'? (content stored in wp_posts or wp_comments shows many wrong accents) or PHP? (mbstring, maybe?) or Apache? (htaccess looks good, adding AddDefaultCharset utf-8 doesn't solve anything).    What can I do or test and how? (I'm not a developer but I can manage some basics).  Thanks in advance for your help!


combinatorial proof of Vandermonde's Identity

So I can not figure out the combinatorial proof for Vandermonde's Identity for the example  $\sum_{i=0}^k \binom {k} {i}^2 = \binom {2k} {k}$ Any help would be appreciated.  Figured it out, thanks :)


Stackoverflow error when trying to implement a quick sort

I am implementing a quicksort and i am getting stackoverflow error.I have tried muliple times and getting frustrated by seeing this error.Can anyone please help me guys  import java.util.Arrays;  public class QuickSort {  public static void main(String[] args) {     int[] arr = { 5, 7, 6, 1, 3, 2, 4 };     int lowerIndex = 0;     int higherIndex = arr.length - 1;      quickSort(arr, lowerIndex, higherIndex);      System.out.println(" FiNaLly " + Arrays.toString(arr));  }  private static void quickSort(int[] arr, int lowerIndex, int higherIndex) {      int pivot = arr[arr.length - 1];     int i = 0;     int temp = 0;     int middle = arr.length / 2;     for (int j = 0; j < arr.length - 1; j++) {         if (arr[j] < pivot) {             temp = arr[i];             arr[i] = arr[j];             arr[j] = temp;             i++;         }         if (i == middle) {             int swap = arr[middle];             arr[middle] = arr[arr.length - 1];             arr[arr.length - 1] = swap;         }      }     int q = Arrays.binarySearch(arr, pivot);       if (higherIndex > lowerIndex) {         quickSort(arr, 0, q - 1);     }       if(q<arr.length-1){           quickSort(arr, q+1, arr.length-1);       }  }   }


I'm in the need of an inverse public-key encryption method where you encrypt with the private key and decrypt with the public key. In other words an asymetric encryption where you can't generate the encryption key from the decryption key. Does such encryption exist? If yes which, and which would be the fastest?  If nothing like that exists I would be glad if you helped me out with my situation:    I need to authenticate users logging in from my Java application in the way that the response from the server cannot be falsified and thus giving the user full access to the application. Using public key encryption was an obvious method, I would decrypt data received from the client to confirm the credentials. This won't work because if someone manages to decompile and get the private key from the code, they would be able to generate the public key, which would make them able to crack my application again. So any ideas how I can get this secure?


How to remove unwanted system applications in Andriod on Samsung Tab 4 T231?

Several apps come preloaded on the tablet and I want to trash them. What's the way out?


Which of the following subsets of $ \mathbb{R^2}$ are compact?  $\displaystyle \{(x, y) : xy = 1\}$  $\displaystyle \{(x, y) : x^{\large\frac{2}{3}} + y^{\large\frac{2}{3}} = 1\}$  $\displaystyle \{(x, y) : x^2 + y^2 < 1\}$ I am stuck on this problem. Can anyone help me please?


My feature request (or anti-feature-request perhaps) is the following: Let's stop displaying a user's accept rate.  For those of you who know "Fawlty Towers", the whole issue of a visible accept rate and our behavior towards it starts to feel like .   We generally seem to agree that harassing a user about it is not appropriate and that our decision to answer a question should not depend on it, yet we display it in varying terrorist-threat-levels of color. Yes dear users, please don't pay any attention to the brightly orange colored percentage you see there. And whatever you do, don't bring it up.  But as long as you're displaying the accept rate, people will comment on it, criticize users for it and possibly reconsider answering because of it. And while I'm of the opinion that a low accept rate should not stop you from answering (we're here to make the internet better after all) and that the possible reputation gain (or lack thereof) should not factor in either, I can't blame users for considering it. It's in their face after all. And we're only people.   So let's take the issue off the table. Or at least partially. Information about a user's acceptance behavior can still always be gathered from the profile. But at least that would be less in-your-face.   "But it helps me to see if a user is a help vampire!" I'm still wondering if those are of the sparkly variety as well, but I digress. So what? If the question is bad, downvote it. Evaluate a question on its individual value. There is no need to take a user's history into account. There might be a correlation between the quality of a question and a user's accept rate, but there doesn't have to be. And if there is, the bigger problem is the question's quality.  "Exactly! A user with a low accept rate might indicate there's a problem!" I'm not arguing we should get rid of the accept-rate value within SO/SE. After all, this Q&A works based on up and downvotes, as well as the acceptance of an answer. But why not use it behind the scenes to (very occasionally) nudge the user with a statement like:      "You have received several answers to your questions, yet have not accepted an answer as correct or helpful in a while. You might want to evaluate them and where possible ".    After all, in the various questions with regards to comments on low accept rates, if any comments are encouraged at all, then they are of this soft variety. So why not let the system take care of that?  I feel this would take the whole issue of accept rate off the table, while still providing the user with the information he might have missed or needs. (As a bonus, it would reduce the frequency with which the topic is brought up here on Meta) And those users who would ignore this information are most likely not convinced by a displayed percentage either.


Proof-verification about prime and maximal ideals.

Suppose that $A$ is a commutative ring with $1$ and suppose that $\forall x \in A   \exists n >1 \in \mathbb{N}$ dependent from x such that $x^n=x$. Prove that if $I$ is a prime ideal then $I$ is maximal.  Proof: Suppose that $I$ is prime. Then $A/I$ is an integral domain. Let $a \in A/I$. Then we have that exists $n$ such that $a^n=a \implies a(a^{n-1}-1)=0 \implies a=0 \vee a^{n-1}=1$ because $A/I$ is a domain. Now, if $a \neq 0$ then $a \times a^{n-2}=a^{n-1}=1$ so each $a \in A \setminus \{0\}$ is invertible and then $A/I$ is a field, so $I$ is maximal.  Does this proof seem legit? Thanks in advance. Can you suggest other ways to solve this?


What is the effect an average person feels when he/she meets a celebrity like Justin Beber or JFK in person?

What is the effect an average person feels when, for example, that person meets a Justin Beber or JFK in person?   I saw a documentary on JFK (I don't remember which one) once and they mentioned this syndrome where doctors in the hospital were tense and jittery ("don't know what to do, don't know what to say") during the time they were trying to bring  him back after he was shot since they were operating on a celebrity of that stature.   The phrase used was some kind of social syndrome.  Like one could say cold feet syndrome....but cold feet is a medical symptom too so it cannot be used.


Automatic award of bounty after it expired, for pre-existing answer, when the reason for bounty was to award exceptional answer

Imagine a situation where you want to reward an exceptionally good answer to a question, with an additional bonus bounty. Why don't we have the ability to specify which answer it is in the first place, so it'll get the bonus automatically at the expiration of the bounty?   says   If you do not award your bounty within 7 days (plus the grace period), the highest voted answer created after the bounty started with at least 2 upvotes will be awarded half the bounty amount. If there's no answer meeting that criteria, the bounty is not awarded to anyone.   Question: Does that mean that if no new answers were created after the bounty was started, the bounty won't be automatically awarded to any of the pre-existing answers, and will go completely to waste?   I can see the reason for such behaviour for bounties which solicit new answers, but the whole reason for this bounty in the first place was to reward a pre-existing answer?!


I'm little confused about the following real conditional sentence. The purpose of the sentence is to tell that Freedom cannot be achieved by merely chanting or dancing on the streets. Do you think any of the following are correct?  Had freedom been achieved by howling, dancing or running around the streets, then animals in the zoo would have been out of the cages long ago.  OR  If freedom were to be achieved by howling, dancing or running around the streets, then no animals would have been kept in cages.


Let $\mathbb{Z}[\frac{{1+\sqrt{-3}}}{2}]$ be the ring of integers where $\alpha=\frac{{1+\sqrt{-3}}}{2}$. I wish to show that $1-\alpha$ is a prime and check whether 3 is a prime or not.  To show that $1-\alpha$ is prime, suppose $1-\alpha$ divides $(a+b\alpha)(c+d\alpha)$. Then I wish to show that it divides one of them. I wrote down the division algorithm for $1-\alpha$ divides $(a+b\alpha)(c+d\alpha)$ but it's a big mess that I can't seem to make sense of. Any help is appreciated.


If Avatar Wan lived 10,00 years prior to Korra's lifetime, then how many Avatars have there been?


Linear Regression makes impossible predictions

I have created a multiple linear regression model to predict prices and about 17% of the predicted prices have come out to be negative.  Is there a way to correct for this error, or does it mean that the independent variables are not good predictors?  The R^2 coefficient is 0.865.


Shrinking Databases in a maintenance plan

Everything I've heard (including from Microsoft) says you should never shrink a database. Yet a software vendor (Symantec) is telling us to do DBCC SHRINKFILE on the SQL 2012 databases and logs related to a product of theirs called Enterprise Vault.    Should I follow the recommendation of Symantec and shrink or the recommendation of Microsoft and everyone else to not shrink?


Suddenly all the system windows have this weird font. I can't read nor understand what the system is asking me. How can I change it to normal fonts?    I'm using OS X Yosemite 10.10.3


Finding E[Y] and V(Y) for Continuous Random Variable

I've been at this one for a while:   A random variable $X$ follows the distribution $$f_X(x) = \begin{cases} Cx^2&,\quad -2\leq x \leq 1\\0&,\quad \text{Otherwise}\end{cases}$$and  $Y\triangleq X^2$.  Find E[Y] and Var[Y].  I calculated C = 1/3.   I've tried $\int_b^a yf(y) dy$ for E[Y] and a similar formula using $y^2$ instead of $y$. The integrals were executed piecewise.   I could use some help, as all of my attempts (variations on the above two strategies) have been dead wrong.  The similar question on the board does not appear to address the calculation of these variables.


If my data is stationary, can I also write that it is homoscedastic? Does stationarity imply homoscedasticity of the data?


Show that for any $k$-cycle $(a_1 a_2...a_k) \in S_n$, and for any permutation $\pi \in S_n$, $\pi(a_1...a_k)\pi^{-1}=(\pi(a_1)..\pi(a_k))$

Show that for any $k$-cycle $(a_1 a_2...a_k) \in S_n$ where $S_n$ is the set of all permutations of n elements and $(a_1...a_k)$ represents a cycle, like $a_1$ goes to $a_2$ and ... and $a_k$ goes to $a_1$, and for any permutation $\pi \in S_n$, $\pi(a_1...a_k)\pi^{-1}=(\pi(a_1)..\pi(a_k))$.  I thought about this logically, like if an element is not moved in the cycle, then the permutation $\pi$ and $\pi^{-1}$ will just move it back to its original location.  But I'm not really sure why the final elements from these permutations are in the form $\pi(a_i)$ instead of having a $\pi^{-1}$ in it somewhere.


Listen to the PropertyChanged event of any item in an ObservableCollection

I've created a wrapper collection for ObservableCollection that subscribes to each items PropertyChanged event and rethrows it as its own event ItemPropertyChanged.  I did this using a similar method to what I described .  Is there a better way?  Am I missing another .NET collection that already has this type of behavior?


How to move all data and metadata from Sandbox to Developer Edition?

How to move all org data (Objects, records, Apex classes, VF pages, Triggers, Validation Rules) from Sandbox to Developer Edition?


How to install Adobe Acrobat Reader DC in Ubuntu?

How to install the latest version (Acrobat DC) in Ubuntu?


Can somebody explain me clear the mathematical logic that would link two statements (a) and (b) together? Let us have a set of values (some distribution). Now,  a) Median does not depend on every value [it just depends on one or two middle values]; b) Median is the locus of minimal sum-of-absolute-deviations from it.  And likewise, and in contrast,  a) (Arithmetic) mean depends on every value; b) Mean is the locus of minimal sum-of-squared-deviations from it.  My grasp of it is intuitive so far.


Get or set file details programmatically

Try going to any file, right clicking on it, and clicking on the "Details" tab. Like this photo   I want to change this values. Also Can I add custom properties the file details. Especially I want to do this changes for tif,jpeg,png,pdf files. Can I see my custom properties in "Details" window?  I found this page but it can change only office files.


What am I looking for in a Monitoring Solution?

This is a  about Monitoring Software. Also Related:   I need to monitor my servers; what do I need to consider when deciding on a monitoring solution?


What is the correct form for an ad banner

What is the correct form: "Stop mumbling, start speaking!" or "Stop mumbling, start to speak!" ? This is for an advertisement of foreign language learning appl=. Thanks


Help with second digit in bases/NT problem

Bernardo chooses a three-digit positive integer $N$ and writes both its base-5 and base-6 representations on a blackboard. Later LeRoy sees the two numbers Bernardo has written. Treating the two numbers as base-10 integers, he adds them to obtain an integer $S$. For example, if $N=749$, Bernardo writes the numbers 10,444 and 3,245, and LeRoy obtains the sum $S=13,689$. For how many choices of $N$ are the two rightmost digits of $S$, in order, the same as those of $2N$?  The first observation is that for the units digit to be the same between $S$ and $N$, we need $(N\bmod 5)+(N\bmod 6)\equiv 2N\pmod{10},$ so $N\equiv 0,1,2,3,4\pmod{30}.$ We can get this by parity or because $2N\bmod 10 = 2(N\bmod 5)$ and go from there. But now I'm not sure how to get the second digit, and I've been stuck for a while. How can I go on from here? I think something that can help is that we can write $N=30n+a$ and take mods, but I've made no real progress.


Keep track of where I have upvoted/downvoted

I'd like to see the list of questions and answers where I have left a upvote/downvote. I also would like to see a list of comments that I have upvoted.  Today I only have the count of upvotes/downvotes but no tracking available.  Right know I'm trying to remember where I left a upvote for a really interesting comment. I'd like to copy/mention a phrase of that comment to a blog post I'm writing.  For example: if I click one of my tags, I'm presented with a list of questions I've answered that were tagged with that specific tag. This is the kind of functionality that would help me track my upvotes/downvotes.  I tried Google but couldn't get to the question that contain that specific comment I'm looking for.    Edit: I just found the phrase using Google. This is the query I used:    This is the phrase:     There's a saying: When you finish your   bachelor's, you think you know   everything; When you finish your   master's, you realize you know   nothing; When you finish your   doctorate, you realize nobody knows   anything, including whether or not you   needed to finish a doctorate to   realize that.   Note: I didn't find the comment I upvoted but just found an answer that has the same phrase.


Wordpress Hack on linux apache server - no detectable changes in files

I have a weird hacking case with one of my wordpress sites. It's a small site, basically shows 5 blog posts on whether or not the office will be open/closed. It's not too complicated or anything, but it was hacked and now redirects to some spam/malware sites.  Basically the site loads the pages, and after about 3 seconds it redirects. I've checked the header.php, index, footer, and don't see anything obvious, plus they weren't listed as being changed. The other thing that is weird is I ran a linux command to search for files that have been changed in the last 10 days, and the only ones that came back were ones I touched while checking for these redirects and doing :wq with vi. It doesn't seem like anything on the php/backend side is doing this redirect.  It is hosted on a apache linux server. Would there be somewhere else I can check to see if this redirect is being made? If there was something that was causing it in the php files, wouldn't it redirect immediately instead of letting the site load? There isn't an .htaccess and I don't see anything obivous in the apache.conf file.   After doing some digging I found that there is some script injects in all pages. The script redirects to a page where there is some malicious content. However, the wordpress version control does not say that these pages were edited. It doesn't have anything historical that looks like this had happened. Is it possible that something was changed in the wp-admin to inject these scripts in the editor? Or if you make changes to the wordpress database for a page does it not create a new version? Where would I check that? What permissions should my wordpress site have?  Thanks for the help!


Can I login to any Ubuntu OS as root user with no password?

I mean can I login using Advanced options -> Recovery Menu as root user without any restriction (except for a Full Disk Encrypted system)? Can someone explain how to fix this security hole?  Visual explanation:


How come light in the Violet spectrum looks like a mixture of Red and Blue, even though they are of different wavelength?

How come pure monocromatic light in the violet spectrum is perceived by us as light that is a superposition of 2 other, different wavelength light. is there some scattering process in the eye that causes a both an filtration of one photon (lets say Red) and a shift in the wavelength of the Blue (like Compton/Raman scattering)? Edit: I'm looking for at least a electrodynamical\quantum mechanical explanation. how come purple is "measured" when the wavefunction consists of 2 particles of different wavelength


Ubuntu print output of "find" and "exec" to file

I have a command which list outs events of "Magento 2", which is working fine in the terminal.  I want it's output to be printed into a file but none of the below code works:  find . -type f -exec grep -n -H -A 2 -T "eventManager->dispatch(" {} \ | tee ~/MAGE2EVENTS.txt   Neither this one:  find . -type f -exec grep -n -H -A 2 -T "eventManager->dispatch(" {} \ >> ~/MAGE2EVENTS.txt   I see 'exec' has been used in this code which shows error:  find: missing argument to `-exec'   So how to print the terminal output of this command to file ?


Who introduced the term torsion first and why

In algebra, an element of finite order is called a torsion, and a subgroup consisting of all torsions of a group is call a torsion subgroup. And I just got curioused about the term 'torsion'; who named it and why; because that term appears a bit randomly in math - like Euler's torsion function. As a non-native English speaker myself, I don't see the relationship between the term and the concepts; if I'm not mistaken, torsion means twisting.


I am new to C++, coming from C#. Here is the code :   void function(int n) {     double* array = new double[n];     //some work that can return or throw an exception    //...     delete[] array;    return; }   I know there is no C# using equivalent in C++.   Is there a simple and elegant way to ensure that memory will be released what ever happens ?


Proper response to user abusing "flag as duplicate"

My  was flagged as a duplicate of this  by the same user who posted that question. My question has more upvotes on both the question and the answer, and is (obviously) significantly older. I also happen to think they aren't even the same question--the other question is a much more specific case that most users wouldn't need. It seems to me like a silly attempt by that user to drive more traffic to their own question.  I can't flag the flag itself for review, so what's the proper response to these sorts of cases? Just flag for reopening? Try to get a moderator involved?


How to key in Asian names when making a flight reservation?

Let's assume my name is "A B C" for the argument's sake.  It's an Asian name, and it is written that way in the passport (more or less. Actually in the passport it is written with full phonetic marks and symbols - but is not unrecognisable from the non-phonetic one). The passport doesn't make it clear which part is the family, middle, and first name, it is understood that "A" is the family name, "B" is the middle name, and "B" is the first name.  I've booked an international flight, and the website requires to input names in order of first-middle-last. No problem here, I simply input them as they are. The problem is, when the ticket is issue, the name on the ticket will be "A/C B", unmatched with the one written in my passport. The name on the itinerary is "C B A", also not a match.  The reservation is already booked, and name change is impossible.  My gravest concern is with the given names. The whole given name as written in passport is "B C", while that on the ticket is "C B". Do you think it can be a problem?


Why does Chrome has so many processes running, when I have just opened the application?

I recently noticed Chrome is running multiple processes, immediately after launch, before I even open a new tab or start browsing. Why is this happening? And obviously it is consuming lot of resources, any way to limit this?  OS: Windows 7 (32-bit)  Chrome version: 58.0.3029.81


I want to escape all characters possible and not just the ones predefined in mysqli_real_escape_string

I'm currently using mysqli_real_escape_string. It is working fine but I want to know whether there is a function more broader, which will escape more characters than the predefined ones like ',",\r etc.


Is MYSQLi only for making it safe for people to insert information into your database?

I understand that MYSQLi is so people can't mess up your databases by putting say and ' or something along those lines that can mess up the inserting process, but is that's all its good for? If I made a login and registry system for a webpage, could I have just the registry page insert in mysqli and then have the login just read from the rows as normal MYSQL or does the login need to be mysqli too? If that is the case, would someone mind explain why and what the risk would be if you weren't to login them in with mysqli. Any and all help is appreciated. Thanks.


I can't seem to find a good guide to what the range is on how much nuyen the players should get paid per run.  Is it in a book somewhere, or does someone have some experience in this regard?


I have a dynamic Soql in which I want to pass a set.  I get an error:     System.QueryException: expecting a colon, found '{'   Anonymous window  Set<Id> idSet = new Set<Id> (); idSet.add('xxxxx00000xxxxAAAR'); RS.GetOrder('xxxxx00000xxxxAAAR', idSet);   Class   public class RS {     ..       public static LIST<Order__c> GetOrder(string idField, Set<Id> idSet) {     ..             String where_clause = '';             if (idField != null && idSet == null) { where_clause = ' WHERE Id =\'' + idField + '\'';     }               String where_in_clause = '';             if (idField != null && idSet != null) { where_in_clause = ' WHERE ' + idField + ' IN ' + idSet;           }              String soqlSo = 'SELECT' + cFieldsSo ' FROM order__c' + where_clause + where_in_clause;             system.debug('soqlSo: ' + soqlSo);             List<sObject> sobjSoList = Database.query(soqlSo);     }   Debug  ...FROM Staging_order__c WHERE xxxxx00000xxxxAAAR IN {a1x2o00000xxxxAAAR}   When I add a colon  where_in_clause = ' WHERE ' + idField + ' IN :' + idSet;   I get the error      System.QueryException: unexpected token: '{'


Moment generating funtion of gamma random variable

how would I find the mgf of a gamma rv with parameter k > 0 and λ > 0 ?


Purpose of heat engine is to transfer heat into the useful work, basically. Working object either gas or liquid takes heat from a thermal energy reservoir as a result of which their internal energy increases and this energy is somehow used to do work.  Why would we need a cold body then?


Somewhat similar to:    There's no menu for  in a 16.04 install literally days old.  In this case, unity is working, and pan has always worked sufficiently that I expect this is somewhat new.  If this is a duplicate, pardon, a search for "no menu" shows many, many results.  The menu was there yesterday.  I restarted the application, but haven't yet rebooted.


Why is the electric current is a scalar quantity?

Please help me because I didn't know why. If you know please help me!!


In the case of the same SD, the difference between One sample t-test and Two sample t-test

In the case of the following program, I can think simply it has two times probability between One sample t-test(0.002111) and Two sample t-test(0.001053) to the p-value? x1<-c(1,2,3,4,5) x2<-c(6,7,8,9,10) (m1<-mean(x1)) (m2<-mean(x2)) (var1<-var(x1)) (var2<-var(x2))  t.test(x1,mu=8,alternative="two.sided") #        One Sample t-test #data:  x1 #t = -7.0711, df = 4, p-value = 0.002111 #alternative hypothesis: true mean is not equal to 8  t.test(x1,x2,alternative="two.sided") #        Welch Two Sample t-test #data:  x1 and x2 #t = -5, df = 8, p-value = 0.001053 #alternative hypothesis: true difference in means is not equal to 0


Why did I lose 6 reputation without any record of it?

This all started from the day before yesterday. I logged into my account and found out 2 reputation was gone. I checked my reputation changes, but didn't find any record. The same thing occurred yesterday and today.  What is wrong?


How can I make my file so that I can double click on it, and it runs. It is a .sh script, but I also have files that say:  executable (application/x-executable)  in the description of what they are.  I can't run any of these from terminal, or by double clicking.  If possible, I would like a way using either the GUI or a Terminal, but not a combination of the two.  Here is a screenshot of what I see when I right click then go on properties. The file first:    And the shell script here:    NB: I accept that this is a duplicate (I was looking for it, and couldn't find it, so asked + answered it, hoping that I would find it) however, I don't think the question about .desktop files is a duplicate.


My touchscreen is cracked, so the pointer continuously clicks on the cracked area. That prevents me from using the computer normally.    I have tried the xinput disable 'ELAN Touchscreen' command, and even the one specific to the input number (though it should make no difference), yet whenever I do this, touch is re-enabled after only a few seconds.   Is there some way to disable the screen permanently until I decide to turn it on again (when I finally go to fix it)?


Events not reacting after jquery html injection

I am injecting some html strings to create buttons, however they jquery events don't fire after they have been created. I was told they needed to be "initialized" but cannot find an example. $('#parent_div).html(
click me here
);  will create:

click me here

  And my usual jquery doesn't fire when clicked. $('.clickable-button').on('click', function (){ console.log('clicked'); }  I got it to work by using a parent that existed before the injection with on() $('#parent_div').on('click', '.clickable-button', function(){ console.log('clicked'); }  But it seems like there should be a better way to handle this because I don't always know what the parent is and I don't want to hard code new jquery every time I inject something. How do people usually handle this problem?


Validity of LTL formulas in a given transition system

Say I have the following transition system:    I've understood how I can tell if □a and ⟡b are valid (□a is invalid because a is not true is S2 and ⟡b is valid there is a state (i.e. S1) in which b is true. Please correct me if I'm wrong). But how do I reason the validity of the following formulas:  □(a -> b)  □⟡(a ^ b)   ?


What is a natural response to "Good to see you. How you doing?"? Will a natural response include "doing" as in "I'm doing okay" or will "I'm okay" be more natural?


An ideal which is not finitely generated

Let $K$ be a field and $A=K[x_1,x_2,x_3,...]$. Prove that the ideal $I:=\langle x_i: i \in \mathbb N\rangle$ is not finitely generated as $A$-module.   I have no idea what can I do here, I mean, suppose $I$ is finitely generated, then there is a subset $S \subset I$ with $S=\{x_{i_1},...,x_{i_n}\}$ such that $\langle\{x_{i_1},...,x_{i_n}\}\rangle=I$. How can I arrive to a contradiction? Any suggestions would be appreciated.


I use spaces with 10.9. I run a few applications in full screen mode. While focused on an application in full screen mode every minute or so I switched back to the first space. This happens with no input on my behalf.   I suspected it was an application in the background taking focus. I shut down all applications that do this and have also disabled space switching on application focus. After a reset the issue persists.   I noticed that the tool bar glitches out after the switch happens. It feels like a bug because when the application is not in full screen mode the icons on my desktop will disappear for a split second and then reappear. This seems to be happening with the same frequency as the space switching issue. Has anyone en-counted this? Is there a fix? It's driving me nuts!


How old is Wolverine? Wasn't he in the civil war or something? It seems like movies keep showing flashbacks of earlier and earlier events.


I have previous experience using GIT in other development environment and I never had much troubles using it.   We where using SVN for salesforce, however we want to migrate to GIT for the uncountable number of advantages compared to SVN.   I could configure the remote and local repo without any problem and also I could commit and push the changes to my remote repo.   However, I can't figure out how can we use GIT when more than one developer is doing changes on the repo. I always get conflict after refresh from server.  Sample where bought dev's are working on the same repo/branch  Dev 1:    Refresh from Server  Change code Save to Salesforce Commit  Push to remote   After Dev 1 pushing   Dev 2 (Steps A):   Refresh from Server  Change code Save to Salesforce Commit  Push to remote (Error: out of date)  If dev 2 try pull (or fetch + merge) then Conflict    Other steps we tried  Dev 2 (Steps B):   Refresh from Server  Pull (or fetch + merge) then Conflict   I was thinking in the possibility to use two branches: one for dev, just to be able to push commits to remote repo and the merged code will come always from Salesforce.  But this practice will kill some of the GIT benefices as diff and blame.   I've tried searching on Google unsuccessfully.


More Flight Routes from India to Grand Cayman

Need some more routes from India to Grand Cayman. How can I book air ticket from India to Georgetown, Cayman Islands without any Transit visa that is required by UK/USA, or which are the countries where I can take connecting flight of same airways or different airways without any further transit visa that is required in USA/UK.


Beamer: how to keep an image at its location while using only to uncover text

This question is essentially the same as one of my , except the only difference is that I am using "only" to change the text at the same location (i.e., ). In other words, I am destroying my earlier text as I go, and not adding new ones underneath the previous ones.   Since the text for the first "only" is shorter than the second "only", therefore the image will shift location. I would like for the image to remain at its location.   Here is an example     it may not be obvious but the second image is higher up than the first.  The code is here, can someone find a solution?  \documentclass{beamer}  \usepackage{graphicx}  \title[Title]{Presentation} \author{Sandro Botticelli} \institute{Italy} \date{1484}  \begin{document}   \begin{frame} \begin{figure} \includegraphics[scale = 0.8]{Venus}     \caption{Nascita di Venere} \end{figure}  \only<1>{In the centre the newly-born goddess Venus stands nude in a giant scallop shell. Its size is purely imaginary, and is also found in classical depictions of the subject. }    \only<2>{Alternative identifications for the two secondary female figures involve those also found in the Primavera; the nymph held by Zephyr may be Chloris, a flower nymph he married in some versions of her story, and the figure on land may be Flora. Flora is generally the Roman equivalent of the Greek Chloris; in the Primavera Chloris is transformed into the figure of Flora next to her, following Ovid's Fasti, but it is hard to see that such a transformation is envisaged here.} \end{frame}   \end{document}


I dropped my Nikon 18-55 lens — can I fix it?

The camera fell on the floor and now I can't turn it to 18mm, its stuck on 55mm and only moves 1/2 inch when I try to turn it. Anyway I can fix it?


Octave display error, Really small fonts

I've installed Octave 4.2.0 on Ubuntu 16.04:  wget ftp://ftp.gnu.org/gnu/octave/octave-4.2.0.tar.gz tar xf octave-4.2.0.tar.gz rm octave-4.2.0.tar.gz cd octave-4.2.0/ ./configure make -j8 sudo make install   However there is a graphical bug in my Octave terminal:    The rows in terminal are stupidly small to see the present code.  How can I get rid of this bug?


Given a picture of a piece of paper, how can the picture be transformed to make the paper appear as if looking from above?

I am currently working on a project that requires me to be able to take a picture of a document (say sheet music, for example) and transform that image so it looks like the picture was taken from directly above. This functionality is similar to the app "Office Lens". Most likely, this is a problem in Linear Algebra, but I have never taken it and my friends who have taken it have no clue.  The problem is, given a picture of a document and given the four coordinates of the corners of the document and the ratio of its sides, how can I transform the picture to make the document look like it was taken from above?  My first idea was to consider a coordinate (x,y) in the picture and then define the new coordinates (x', y') to be angles from a point of intersection made by the sides of the document, but this makes no sense. If I did this, the image would appear distorted. How can I do this?


I've been struggling to find a solution to this problem that I found in the archive of my country's Olympiad questions.   I'm particularly interested in a solution that doesn't involve the use of calculus since I know that Olympiad questions do not require the knowledge of calculus to solve but I will also like to see one that uses it.  Here's the problem:  Find the minimum value of $\frac{18}{a+b} + \frac{12}{ab} + 8a + 5b$  when $a$ and $b$ are positive real numbers.


Large Application - should I be concerned about running on VM Ware?

We're going to implement what I consider to be a fairly large and processor intense application in a few months and our Windows team is recommending that we deploy it on VM Ware.  The application will have 5000 users, most of which will be running this application all day as the primary application they need to do their job.  They will be scanning images which will be sent up to this application for processing.    The application has 4 parts: A web server, an extract server, an application server and a database server.  The application server will be bearing the burden of doing optical character recognition against the 2 to 3 million images per day.   The application software vendor has not certified on VM and they don't have any experience with VM, although they seem to be open to supporting us on it.    I am not too concerned about the web servers or extract servers.  But the application server part of the application states that it requires 3 Windows servers with 20 CPU cores and 32GB of RAM each.  The SQL Server database also requires 20 CPU cores and 32GB.     I am not concerned about the network.  We have a fast network and these images are not going to be very large.  I am mostly concerned with CPU (for OCR) and I/O since all of these images need to be written to the database.    We do have a large VMWare platform (using the latest VMWare software) running hundreds of small applications, but our new application will be the largest by far.  The current largest application that we currently have on VM only has about 200 users.  So, we are concerend that we're going to push our VMWare environment much harder than it has ever been driven before.  And I want to make sure that our end users are not impacted in any way by growing pains (e.g. slowness, outages) as we learn how to support this large application on VMWare.    My questions now are as follows.   Would we be better off running this on dedicated Windows machines rather than in a shared VMWare environment, at least at first? Alternatively, should we insist on having our own dedicated VMWare platform at first so that we're not sharing with other applications during the roll-out period.  And then once we see how it performs and how many resources it really needs, then we can start considering sharing. If we do decide to run on VMWare, what are the likely downsides?  For example, is it likely that the end users will experience slower performance?  I've read that VMWare can introduce latency.   Should we bring in a consultant from VMWare to analyze our environment to make sure that it's properly sized and tuned?   Any recommendations on how best to proceed or other things to consider would be greatly appreciated.


Is there any default function/utility to prompt the user for yes/no in a Bash script?

Sometimes I need to ask the user for yes/no to confirm something.  Usually I use something like this:  # Yes/no dialog. The first argument is the message that the user will see. # If the user enters n/N, send exit 1. check_yes_no(){     while true; do         read -p "$1" yn         if [ "$yn" = "" ]; then             yn='Y'         fi         case "$yn" in             [Yy] )                 break;;             [Nn] )                 echo "Aborting..."                 exit 1;;             * )                 echo "Please answer y or n for yes or no.";;         esac     done; }   Is there a better way to do it? Is this utility maybe already in my /bin folder?


Ubuntu 17.10 how to disable favorites hotkey

Or possibly change it, my settings for switching workspaces ( I have static number set ) is Super+(1..N). Since upgrading to 17.10 whenever I use that combination it binds to the favorites on the side bar (aka Ubuntu Dock). Or in the case of Chrome where it has focus it shows thumbnails of the current windows.  This is really odd behavior which I'm assuming is a bug since there seems to be no place to override it and my mappings are clearly set still for switching workspaces which should have precedence over anything else.


Suppose $R$ is a ring with identity and $x^n = x, \,\, \forall x\in R$ for some fixed integer $n \geq 2$. Prove that $x^{n-1}$ commute with any elements of $R$.  In the case $n = 2$, I can show that $x+x = 0$ and $x+y = (x+y)^2 = x + xy +yx + y,$ hence $xy + yx = 0,$ hence $xy = yx.$


Does this quote in Deathly Hallows imply that Dumbledore had used the Killing Curse before?

Chapter 35 King's Cross Pg. 605     “And then . . . you know what happened. Reality returned in the form of my rough, unlettered, and infinitely more admirable brother. I did not want to hear the truths he shouted at me. I did not want to hear that I could not set forth to seek Hallows with a fragile and unstable sister in tow.   “The argument became a fight. Grindelwald lost control. That which I had always sensed in him, though I had pretended not to, now sprang into terrible being. And Ariana . . . after all my mother’s care and caution . . . lay dead upon the floor.”   The "Ariana lay dead upon the floor" really stands out because if it was the Killing Curse that was used, then it explains why Dumbledore felt so much guilt. Not only did Grindelwald escape and make his dreams of dominating the muggle world and breaking the International Statute of Secrecy a reality, but he was also powerless against stopping Ariana from dying.   This might also be the reason why Dumbledore postponed his duel with Grindelwald until the very end, because if Grindelwald knew and revealed who had really killed Ariana, he might have stated that Dumbledore killed Ariana to scare Dumbledore and scar him emotionally for the rest of his life. This might have caused Dumbledore the duel between him and Grindelwald.


What space do the pieces of the gate iris go into?   There is nothing to be seen when the iris is in the open position.   Was this ever explained or depicted?   Or it is just out-of-universe limitations of CGI early in the series that they just gloss over forever?


I deleted my own question, but it's still in search results!

I have deleted a question because of being on hold and also my own misunderstanding of the question type which might be considered as "proofreading". here I want to know:      "How can I delete it completely?"!    Actually I've deleted it but it's still in search results after searching it and also apparently I still get down-vote while the question didn't have answer yet!  Shall I flag it?


How to resolve high priority issue at the time of delivery

What will you do if you find a high priority bug and your client wants to deploy the software after knowing that critical bug and you don't have your Developer to fix that bug he is on vacation?


Trying to push the value I get from the onlick to a empty array and I cant seem to get it right.  var result = [];  $('#submitButton').click(function(){  var textField = $('#textField').val();  $('#result').append(textField, '<br/>');   $('#textField').val('');  result($(this).val());   });


Inconsistent argv declarations in main()

I'm new in c programming. I'm quite confused with the difference between:      int main (int argc, char **argv)   and   int main (int argc, char *argv[])   are they the same in C programming?


I am writing in LaTeX some theorems in which the symbols of Lie Algebras are used. What is the command in LaTeX for the symbol of a Lie algebra g of a Lie group G?


Running OS image from Dell Laptop (set to RAID mode) in VirtualBox

I have two SSD images from two different modern Dell laptops that use the new BIOS that allows you to set your boot mode to "legacy" and then set your SATA mode to AHCI or "Raid mode" (Intel Rapid Storage Technology). These laptops were set to legacy boot and RAID mode to allow Windows 7 to run on them.  Now, these SSD images cannot run when restored to computers that only have AHCI mode. Windows 7 appears to boot correctly and it spends a few seconds on the logo-loading screen and then it goes straight to a blue screen with a STOP 0x0000007b error. The same thing happens in the original laptops if the SATA mode is changed from RAID to AHCI.  I need to run these images in VirtualBox but I get the same BSOD. My question is: Is there something I can change on either VirtualBox or the restored image itself that may allow Windows to succesfully complete the startup process?  I've tried setting VirtualBox to use all different controller options (IDE with its different chipsets, SATA, SCSI and SaS) with no success.  Thanks in advance for any suggestions or comments.


Does 866 cM shared suggest half aunt rather than aunt?

There is a joke in my family that my father's father is not his biological father. He only has sisters and his father is dead, so there's no possibility of a true test. But I'm his daughter and I did a DNA test, and here's what I got.  I got DNA results back and here's what it says about one of my aunts that tested too. Great aunt or cousin is the link they gave us.   12,2% (866,2 cM) DNA shared 19 Segments shared 106,2 cM Segment longest   Does that actually mean the joke is true and my aunt is my half aunt?


Why two objects with the same hashcode are not necessarily equals?

Currently I drilled into the JSE source code for fun. From some tutorials I found a principle two equals objects (i.e. as to object a and b a.equals(b) returns true) must have the same hashcode, on the other hand, two objects with the same hashcode are not necessarily equals. According to the HashTable source code of Java API (), e.g. refer to line 254, we can almost derive equals => same hashcode, but I still can not fully understand why two objects with the same hashcode are not necessarily equals. Anyone can give more reasoning on this? Thanks in advance    Note! This question is more interested in why two objects with the same hash code are not necessarily equals


Is it possible to create a .exe file from a Qt Gui Application

Is there a way to get this application as a ".exe" file. For example let's say I have a login application designed. Can I have it as a "Login.exe" file so that when I have it on my computer and double click on it, it would open up? I have the login.ui file and the login.py file. What would I need to create a .exe file of this application?  Thanks in advance


proving $|\mathbb{N}|\leq|A|$ for any infinite set A

The instruction I received is to build a set $B\subseteq A$, $|B|=\aleph_{0}$. And use induction to prove. I don't really know how to use induction here to prove. Thanks for any help.


Expected minimum distance for $n$ points on a circle

Consider $n$ points chosen uniformly and independently on a circle of circumference $1$. What is the expected minimum (arc) distance between any pair of points? Clearly this is at most $1/n$.   This problem comes under the heading .  We could therefore  answer the question exactly if we were looking for the minimum of $n$ samples from $[0,1]$ but I don't know how to answer my question above.


Which of the "Which" or "That" should I use?

Which one would be better to use in the following sentence? How can I know in the future which of these I should use?  The study deals with the principles of a probabilistic decision support system which-that handles the problem of warning before users are trapped with the attackers’ first move.


Can/should I use baking soda when cooking beans?

My recipe for hummus says to cook the garbanzo beans with a little baking soda to soften them. Does this work with other legumes?   I've often seen the advice against salting the cooking water for beans, as it supposedly toughens them. Will a different sodium compound, bicarbonate, have the opposite effect?   Would love to know the science of this issue.


Reprojecting LiDAR data with libLAS, error: "latitude or longitude exceeded limits"?

I have a lidar file (file.las) with the following spatial reference:  Spatial Reference:            PROJCS["NAD83 / UTM zone 11N",     GEOGCS["NAD83",         DATUM["North_American_Datum_1983",             SPHEROID["GRS 1980",6378137,298.2572221010002,                 AUTHORITY["EPSG","7019"]],             AUTHORITY["EPSG","6269"]],         PRIMEM["Greenwich",0],         UNIT["degree",0.0174532925199433],         AUTHORITY["EPSG","4269"]],     PROJECTION["Transverse_Mercator"],     PARAMETER["latitude_of_origin",0],     PARAMETER["central_meridian",-117],     PARAMETER["scale_factor",0.9996],     PARAMETER["false_easting",500000],     PARAMETER["false_northing",0],     UNIT["metre",1,         AUTHORITY["EPSG","9001"]],     AUTHORITY["EPSG","26911"]]   Then I reproject it to WGS84 with las2las:  las2las --a_srs EPSG:26911 --t_srs EPSG:4326 -i file1.las -o output.las   And I get:   Spatial Reference:                GEOGCS["WGS 84",         DATUM["WGS_1984",             SPHEROID["WGS 84",6378137,298.257223563,                 AUTHORITY["EPSG","7030"]],             AUTHORITY["EPSG","6326"]],         PRIMEM["Greenwich",0],         UNIT["degree",0.0174532925199433],         AUTHORITY["EPSG","4326"]]   But when I try to revert the transformation: from WGS84 to NAD83/UTM 11N, I get an error:  las2las --a_srs EPSG:4326 --t_srs EPSG:26911 -i output.las -o wgs2utm.las ERROR 1: latitude or longitude exceeded limits error: Could not project point for ReprojectionTransform::latitude or longitude exceeded limits0.   Why I got this error, if I am just reversing the transformation (originally from NAD83 to WGS84, and then from WGS84 to NAD83)?.


I thought I'd post this as it illustrates a problem often encountered on ELU.     In structures such as 'football manager', is 'football' a modifier or   a complement of the head noun?   I've seen both terms used as if there were only one possible correct answer. However, I've come across widely differing definitions of both 'modify' and 'complement' as used in grammar. I believe that people stating baldly that this is either one or the other are assuming a grammar that they prefer, rather than giving a balanced overview.  Notice that I intend this question to explore the usage/s of the term 'modify' and of the term 'complement' in this context. There may be overlap with the question of which word-class 'football' fits into, but that decision hardly answers the question.


How to export Blender file so it can be opened with the textures on another machine?

Basically, my client wants to open the Blender file I'm working on but every time I send him the blender file he manually has to connect the textures with the objects.   Is there any way he can just simply open the .blender file with everything ready to go?


Splitting polygon into equal area polygons in QGIS 3

There is a Plugin in QGIS 2.18 called "Polygon Divider" which divides an irregular polygon into smaller equal-area polygons of a specified/custom-sized but in QGIS 3.x version there is no "Polygon Divider" Plugin or tool to perform that task. So, how to divide/split the irregular polygon into equal area/parts polygons in QGIS 3.6? Is there any Python script to split such type of polygon? As shown in the below picture:


With my understanding and from an absolute knowledge of the subject, that according to JK Rowling, wizards and witches are born with their magic and it's a part of their DNA. Magical people are genetically somewhat different from Muggles, and this difference is the reason for their magical abilities. (Extracted from posts of this page)  The answers for these questions  are related, but none suitably answer whether a wizard can permanently lose their powers: ,  and .  And other information source:    Can a wizard lose his magic and become a squib or somthing like this? If this is possible, can you explain how it would work?     EDIT 1: Why  doesn't answer my question   All of the examples of the answer are affected or produced by emotional trauma or psychological state, and would presumably be reversible if the wizard gets to a better mental state. However I'm looking for a way to entirely "delete" a wizard's ability to use magic or otherwise render their magical powers unusable.  In the examples given in the answers, the characters never lose their magical ability to the point where it would be impossible for them to regain their powers. They are only in a temporary state where they are unable to use their magic - they don't permanently lose their powers. I'm asking about a situation where this is actually a permanent state, or if there's a way to make the temporary state permanent. The answer may possibly be outdated in some things, for example the Ariana Dumbledore case. In "Fantastic Beasts and Where to Find Them" the existence of the Obscurus gives an explanation for what happens in these cases... It's not confirmed yet as canonical to say this is what happened to Ariana, but her symptoms as described are very similar to those of one of the characters in "Fantastic Beasts and Where to Find Them".


I have a new arch install with Gnome Window Manager and Cinnamon. I created ~/.xinitrc with the command start cinnamon, and restarted the computer.   Now the system boots into the login screen for Gnome and Cinnamon, but there is no command line shell available in the GUIs, and I'm unable to boot the computer into command line mode either.