In many schematics, we have two capacitors connected in parallel to a crystal? Why do we have capacitors parallel to crystal? Whats the purpose? How are the capacitor values determined ?

I'm having hard time understanding the principles of piezoelectric crystal oscillators.  I've found this picture:   I understand that "load capacitance" is something you have to connect to a crystal. I understand that this basically means having to connect an external capacitor in parallel to the crystal. I also realize the basic principle of piezoelectricity; voltage/electric field across the crystal will physically deform the crystal, and the deformation also creates an electric field. So why is load capacitance needed? And if it's always needed and it's fixed, why is it not included in the crystal package? Is it because we need to sometimes operate it in series mode instead? In the equivalent circuit diagram, there is already a capacitance, Cp, parallel to the series resonant arm. Why do we need even more capacitance in parallel to that?  In the picture I provided, there is a curve showing impedance of the crystal with respect to frequency. Why isn't the load capacitance showing in the formulae for the resonant frequencies?


I upgraded to 12.04 right after it was released, and once it installed, I was eager to try the new features. After fiddling around with most of them, I forgot to try the brand new HUD. I tapped the alt key... and nothing happened. I searched around to see if I disabled it, but I didn't. Also, holding alt still showed the appmenu at the top. Is there a reason that it isn't working on my computer?

My HUD is not working after I upgraded from 11.04 (and or 11.10).  It prompts for command and it tries loading for 4 seconds then gives up.


Does the following limit exist? $$\lim_{x \to 0} \frac{1}{x}\sin\left(\frac{1}{x}\right)$$  If yes, then I have to find it; if no, then I need to give reason why. I couldn’t figure out how to prove this formally, can someone please help me out. Edit: please note that sin is multiplied by 1/x here and not x.

Does the following limit exist? $$\lim_{x \to 0} x\sin\left(\frac{1}{x}\right)$$  If yes, then I have to find it; if no, then I need to give reason why. I couldn’t figure out how to prove this formally, can someone please help me out.


My problem: I have 2 objects and want to use an overloaded .equals() to compare the name and color attribute of the two objects being compared and if they are the same, it will return true.  I have two objects. car1 and car2  GameCar car1 = new GameCar ("MyBuddy", "Red", 19); GameCar car2 = new GameCar();   The GameCar class has 3 private member variables:  private String name; private String color; private int position;   Here are the two constructors for GameCar -  GameCar() {     name = null;     color = null;     position = 0; }  GameCar(String n, String c, int p) {     name = n;     color = c;     position = p; }   In order for car2 to get its information, I have this:  car2.getCarInfo();   Definition of getCarInfo() -  public void getCarInfo() {     Scanner keyboard = new Scanner(System.in);     System.out.print("Enter the car name: ");     name = keyboard.next();     System.out.print("Enter the color: ");     color = keyboard.next();     System.out.print("Enter the starting position: ");     position =  keyboard.nextInt(); }   And now here's the equals() overloaded function -  public boolean equals(GameCar car) {     if (name == car.name) return true;     return false; }   Here is where I'm using the equals() -  System.out.println("Same cars? " + car1.equals(car2));   For some reason, the equals() function, even if I set the car2.name and car1.name to be exactly the same prior to going into the equals(), it still returns false.  However--- If I set name="something" and car.name="something" in the overloaded equals(), then it will work.

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


I have a background job, say jobid 1, in a tab of gnome terminal. Can I move it to a another tab of genome terminal?  I understand that the shell process in the first gnome terminal tab is the parent of the background process. So am I to change the parent/owner of the background process?  I guess that it is the same regardless of a process to be moved is running background or foreground?  Do I need some identifiers of the tabs of gnome terminal, tty things?  I don't really know how to do the above. Just some guessing.

I have a running program on a SSH shell. I want to pause it and be able to unpause its execution when I come back.  One way I thought of doing that was to transfer its ownership to a screen shell, thus keeping it running in there.  Is there a different way to proceed?


I've always used "gender" when I want to talk about whether a person is male or female. But I came across  on a  here:     Correct usage is "sex" for humans and other animals. "Gender" is for things like connectors and pipe fittings. People are just squeamish about the word "sex."   So which one is more correct and more importantly which one should I use? It would be great if you can base your answers on facts, references, or specific expertise rather than just personal opinions.  Note: I've already seen the question   but it does not answer my question.

What is the difference between gender and sex?  says that gender is The mental analog of sex but that's too high English for me.  Basically, I'm developing a web-application that stores people's profile along with a field for gender/sex. Which name would be more appropriate?  __  [UPDATE]  After getting these good answers, I can figure out that,   Sex - Biological characteristics  Gender - Social characteristics   And, well, for my web-application, I went with the term sex, as it sounds more scientific and less political. P.S. Values for sex are clearly defined and can be easily validated (only two values * + an optional blank value).  * plus some anomalies.


It is the first time I have encountered such a use of "a" combined with an -ing form.Maybe you will be a-basking in the sun this afternoon. Is there any reasonable explanation?

For example,   If this van's a-rockin', don't come a-knockin'  (song title)   (song title)   I have a few related questions:   What is the "a-" or "-a" called? Is there a function beyond a rhythmic one? Why is "a-" attached to a word at all -- and why attach to a word at all?


I go over some code and I saw the following code     var failedExtPlugins = PluginR.$getFailPlug();   It seems that this time the $ is not refer to jquery object (yes I know that when you use Jquery you start with $) I guess,so what does it mean? it look like regular method...but way the use $

I quite often see JavaScript with variables that start with a dollar sign. When/why would you choose to prefix a variable in this way?  (I'm not asking about $('p.foo') syntax that you see in jQuery and others, but normal variables like $name and $order)


When editing you can enter a one-line comment "Edit Summary".  It would be nice if a comment could be left when rolling back.  Can this be added at some time?

I just had an occasion where someone reformatted the code in my question, not because it was ill-formatted, but to match his preferred style. I would have liked to be able to type a reason for rolling back the edits when I did so - could the ability to do that be added?


Compute the complexity of the following Algorithm?  I have the following code snippet:  i = 1; while (i < n + 1) {     j = 1;     while (j < n + 1) {         j = j * 2;     }     i = i + 1; }    plz explain it in detail   I want to know the the steps to solve the problem so I can solve such problems

Most people with a degree in CS will certainly know what . It helps us to measure how well an algorithm scales.   But I'm curious, how do you calculate or approximate the complexity of your algorithms?


I am looking for the title of a fantasy series I once started reading at a friend’s house a long time ago, and never got the chance to get the name of the author/series.   It involves the main characters going to multiple worlds; I believe the story opens up on a world ruled by elves and the humans are commoners, slaves, or working class. Also, this world has a series of floating islands that can only be accessed by floating ships, which only the elves have access to.   Another thing I remember is that the series had a unique take on magic, which was done by chanting mysterious words, while using/moving the body in complex movements, almost like a dance. There were two "races" of magic users: one race had mostly-white hair with dark tips, while the other race had mostly-dark hair with white tips.  One of the main characters is one of these races (I can't recall the names of the races, but I know one started with an "A" and the other with a "P"), and I believe (if memory serves right) he is the last of his race, and his name was something like Alfred, Albert, or Alabert. One of his character traits was that he was very clumsy, which made it hard for him to cast spells, but when he did pull one off they were immensely powerful spells.  I also remember there being many worlds that the group of main characters travel to, one being a sort of jungle world with ancient ruins, and a race of huge golems, created by "Alfred's" race long ago by using magic. Another world had huge winged beasts that end up attacking the group of main protagonist, and Alfred ends up casting a very powerful spell, turning himself into a huge dragon, and saving the day.   I know it isn't a lot to go on, but I hope that someone can help me, because I have been searching a long time for this series. I really do want to finish it, I remember it being one of those series that gets you all excited and you can't stop reading. Sorry for the long description. Please, any help is better than none. Thank you all for your time.

I'm trying to identify fantasy book series I encountered some time ago. Here are things I remember:   it was a fantasy setting but with some s-f elements; with many worlds and possibility to travel between them; resembling  setting a little, the two main races were non-human and probably hostile to each other,  a labyrinth (?), which somehow played an important role in the plot, a protagonist was some kind of emissary and was sent on a mission to another worlds  time period: 80s - 90s    Does anyone know what it is the name of the series?


I'm trying to find some canonical support for a jedi, dark jedi or Sith who wield a periwinkle lightsaber. Periwinkle is a different color than Ochre, incidentally. Periwinkle= sRGBB-204, 204, 255. Ochre= sRGBB-204, 119, 34. For anyone with enough time on their hands to identify (non) duplicate questions on a science fiction and fantasy website, I'd think that research would have been done. At any rate, Comic-Book-Guys' concerns aside, does anyone know if there is evidence for such a thing?

I just saw the fan film  and the Force-sensitive bounty-hunter, Korbain Thor, wielded an ochre lightsaber (or at least that's what  described it as).   I'm just wondering if ochre is a canon color for a lightsaber?


Firstly I would like to know if this is valid for every kind of wave, or are there any conditions/exceptions where this is not valid.  But the main question is, is it possible to prove this fact for a general wave intuitively, rather than taking specific waves and deriving equations and showing it?

I'm a mathematics student trying to grasp some basics about wave propagation. A sentence I find very often in introductive physics textbooks is the following:      In a wave, energy is proportional to amplitude squared.   This is something I would like to understand better in the case of mechanical (linear) waves.  The simplest model is the vibrating string of mass density $\mu$ and tension $T$: here an element of string of rest length $dx$ and vertical displacement $y(x, t)$ possesses a kinetic energy $\frac{1}{2}\mu dx \left( \frac{\partial y}{\partial t}\right)^2$ and a potential elastic energy $\frac{1}{2}T dx \left( \frac{\partial y}{\partial x}\right)^2$. So we have the total energy   $$dE=\frac{1}{2}\mu dx \left( \frac{\partial y}{\partial t}\right)^2+\frac{1}{2}T dx \left( \frac{\partial y}{\partial x}\right)^2,$$  which completely explains the sentence. Can we obtain a similar formula for higher-dimensional waves? How should I modify the above formula for a (simplified model of an) elastic membrane, for example? I would expect something like   $$dE=\text{some constant}\left(\frac{\partial z}{\partial t}\right)^2+\text{some other constant}\left\lvert\nabla z\right\rvert^2,$$  where $z=z(x, y, t)$ is the vertical displacement. Am I right?


One of the things that makes him great is he brings it every night.   I'm pretty sure it should be that make him in the plural, because one of the things is referring to a lot of things and a lot of things should take a plural verb. But I always hear native speakers in America say it in the singular, so with an s.  Another example:     This is one of the responsibilities that comes with greatness and he understands that.   Native speakers always use the verb in the singular (here, comes) even though [I believe] it is grammatically incorrect to use the singular form of the verb there.

If I am talking to somebody about a certain group of people in the third person, and then want to refer to the person I am talking with as one of those people, which do I say?     One of them were you      One of them was you.


In Star Wars: The Last Jedi     It's a major plot point that the Resistance must find some way to escape the First Order before their ships run out of fuel.    In space, there is very little resistance to motion, so once something starts moving, it tends to stay moving. This is why real life spacecraft barely need to burn fuel once in orbit of something. When      the rebel ships are being chased by the First Order, they appear to stay the same distance from the ships after initially moving out of effective range.    The only way this makes sense with both distance and fuel burning is if they are accelerating at the same rate. At some point I believe someone says the Resistance ships are faster (I am assuming this refers to acceleration, because neither fleet should have a terminal velocity other than the speed of light), so I suppose they were only accelerating as fast as the First Order to save fuel, and had determined they were not sufficiently fast to totally outrun the First Order.   However, I find it hard to believe that two fleets could accelerate, near the maximum capacity of one of them, for at least 18 hours and not go into hyperspace. These are ships that can traverse systems in minutes if they choose, and I find it equally hard to believe that the First Order would only use a fraction of their available power in pursuing the rebels. How then were the rebels able to run out of fuel without changing their velocity significantly?

In the universe of Star Wars, many ships (excluding the X-Wing - the large circles on the front are retro thrust nozzles) appear to lack forward-facing thrusters or retro thrusters.    The TIE  fighter has 2 engines, . So, what slows it down?  I read on Wookieepedia that they turn using etheric rudders, and read on a chat forum (I do not remember which) that they can use etheric friction to slow down, but I couldn't find any references to this. Do they perhaps use special repulsors to slow down? In  many people answered that they use special repulsors to control their flight and direction, so perhaps could the same technology be used to slow them down?  So, how do Star Wars ships slow down?  To clarify, I want answers based on the Star Wars universe, not real-life physics. I am also willing to accept answers based on the Star Wars Extended Universe (now named Star Wars: Legends).


In writing Principia Mathematica, was one Russell's purposes to formally describe all the possible variations of logical concepts and reasoning that can be used in mathematics? For example, suppose that a mathematician of the future manages to prove theorems about natural numbers by reasoning on the properties of a subset of the complex numbers that has not yet been defined.  My question is, was one of Russell's purposes to be able to formally capture in advance all abstract concepts upon which the mathematician's conception of the subset will be based,  and also his reasoning over its properties,  before this subset is conceived by the mathematician's creative power?

In philosophical contexts, the Principia Mathematica is sometimes held in high regard as a demonstration of a logical system.  But what did Whitehead and Russell's Principia Mathematica achieve for mathematics?


I found the following equation in a Blog (), which could help me a lot solve a certain problem:  $\min(f(x), g(x))=\frac{f(x)+g(x)–|f(x)–g(x)|}{2}$  The problem is I don't know, how the author came up with that and I never saw it in a textbook or someone else using. Does somebody may have an idea where it comes from or how to verify it.   cheers

I came across the following problem in my self-study of real analysis:     For any real numbers $a$ and $b$, show that $$\max \{a,b \} = \frac{1}{2}(a+b+|a-b|)$$ and $$\min\{a,b \} = \frac{1}{2}(a+b-|a-b|)$$   So $a \geq b$ iff $a-b \ge0$ and $b \ge a$ iff $b-a \ge 0$. At first glance, it seems like an average of distances. For the first case, go to the point $a+b$, add $|a-b|$ and divide by $2$. Similarly with the second case.   Would you just break it up in cases and verify the formulas? Or do you actually need to come up with the formulas?


So it looks like there was a recent change or regression that isn't showing the score/answer counts for the tag tracking.  What happened to the counts?  Please add it back, or at least explain why it needed to be removed.  The counts are shown for regular non-tag badges...    This makes the tag selection page mostly useless now, especially with the different scaling for the different badge levels.

Something changed recently, and since a picture is worth a thousand words:    Until not very long ago, the "score" and "answers" labels were followed by numbers indicating the values of the progress bars underneath. So "score" might have "90/100" in this example. I'm not seeing that now for any of the badge progress indicators, so it looks like a recently introduced bug.


The following solution to the mutual exclusion problem, discussed earlier, published in 1966 by H. Hyman in the Communications of the ACM. It was listed, in pseudo Algol, as follows.    1 Boolean array b(0;1) integer k, i,   2 comment process i, with i either 0 or 1, and k = 1-i;   3 C0: b(i) := false;   4 C1: if k != i then begin;   5 C2: if not b(1-i) then go to C2;   6     else k := i; go to C1 end;   7     else critical section;   8     b(i) := true;   9     remainder of program;  10     go to C0;  11     end   why does it fails?, and is not a complete answer, I see the problem firstly because it only treats two processes, so it is not scalable...

Please take a look on the following pseudo-code:  boolean blocked[2]; int turn; void P(int id) {       while(true) {              blocked[id] = true;              while(turn != id) {                     while(blocked[1-id])                     /* do nothing */;                     turn = id;              }              /* critical section */              blocked[id] = false;              /* remainder */       } } void main() {       blocked[0] = false;       blocked[1] = false;       turn = 0;       parbegin(P(0), P(1)); //RUN P0 and P1 parallel }   I thought that a could implement a simple Mutual - Exclution solution using the code above. But it's not working. Has anyone got an idea why?  Any help would really be appreciated!


Yeah.... Ubuntu 18.04, it was fully updated earlier today.   So, heres how it went, everything was fine, I shut down my PC as normal, a couple hours later, I turned my PC back on and for some reason it booted into a terminal.  I tried rebooting, running ¨startx¨ and ¨init 3¨ and ¨init 5¨ but nothing worked. I tried running ¨sudo apt install ubuntu-desktop¨ and ¨sudo apt install --reintall ubuntu-desktop¨ but no help.  So, after doing a bit of research, I had decided that it was potentially a display manager issue, so I ran ¨sudo apt install lightdm¨ and selected that as the default display manager in the window that popped up. I rebooted after that, but I was stuck on the dots scrolling to the side screen. (managed to fix this later)  Next, I rebooted (went into terminal again), and ran ¨sudo dpkg-reconfigure gdm3¨ I don´t quite remember around here, but I think what happened was I ended up reinstalling gdm3 and running sudo dpkg-reconfigure gdm3¨ again, then rebooting.  But- Once I had rebooted, into a GUI I might add, it was.. different. I am sure that I was using GDM3 before, but everything was all blue and old looking, there was no favourites bar and on the desktop there was applications labled ¨file system¨ and stuff like that. However, I did notice that all my files were still there, they even had their custom icons.  So, this got me very confused, what had happened to my desktop?   I then went into a terminal window (ctrl + alt + f3 I think) and tried reinstalling gdm3, tried using lighdm, but no help. After trying to get it to work one last time, I rebooted and tried reconfigurng gdm3 one more time. It threw up an error saying that action ¨reload¨ was required or something like that.  After rebooting and reinstalling gdm3 I could reconfigure it (set it to default)  OK GREAT.  now I rebooted and was greeted with a login screen that looked familiar.. no background, but I dont remember if I had set one.  BUT LOGIN LOOP  I changed the ownership of .Xauthority and .ICEauthority to myself, this fixed that issue.  But now, I am left with a bizzare desktop environment, all my files are still there, and even my desktop files have their custom icons! yayy! but what hapened to my - stock ubuntu I might add - desktop environment and how do I get it back?  Picture of the weird environment:

In general what is the approach to switch the desktop environment or window manager on Ubuntu? The main difference between stock Ubuntu, Kubuntu and Lubuntu is supposedly the use of Unity vs. KDE vs. LXDE.  However, in order to try various desktop environments and window managers I don't want to have to reinstall the respective flavor from scratch just to get a particular desktop environments or window manager. There probably is an easier method than that.  The question: How can I easily test different desktop environments and respective compatible window managers (say KDE, LXDE, Unity, GNOME, XFCE and StumpWM)?


I want to implement a python function to execute a bash command. for example:  def run_command(): # run 'python test --a' command

How do you call an external command (as if I'd typed it at the Unix shell or Windows command prompt) from within a Python script?


I am using aura:iteration for the checkboxes as below--

Quote Id

View

                             <aura:iteration indexVar="index" items="{!v.listQuotes}" var="quote">
                                                                              <lightning:input aura:id="chkbox" id="{!quote.Id}" type="checkbox" onchange="{!c.checkboxSelect}"/>
{!quote.Name}
                                     	                                          <lightning:button name="{!quote.Id}" variant="base" label="View" title="View" onclick="{!c.viewQuote}" />
                             </aura:iteration>

   Now when I check the checkbox, I need to uncheck other checkboxes, so that at any given time I have just one Id with me.  I am not able to find a way to do that-- Here is what I tried--  checkboxSelect : function(component, event, helper) {     var quoteRecId = event.getSource().get("v.id");     var checkValue = event.getSource().get("v.value");      console.log('Inside checkbox Select-->'+quoteRecId);      console.log('Inside checkbox Select checkValue-->'+checkValue);      var quotes = component.get("v.listQuotes");     var resetChecks= [];     for(var i=0; i<quotes.length; i++){         if (quotes[i].Id !== quoteRecId) {             component.find(quotes[i].Id).set("v.value", false);        }     }  }   Console Logs--  Inside checkbox Select-->a0222000001ssxGAAQ EmployerViewQuotes.js:28 Inside checkbox Select checkValue-->

I have two checkboxes in a lightning component, when we click on the first checkbox it marks true to the other checkbox, it works well only with the UI tags but doesn't work when I convert it to lightning tag  <ui:inputCheckbox aura:id="box3" change="{!c.selectAll}"/>  <ui:inputCheckbox aura:id="boxPack" value=""                                                          change="{!c.checkboxSelect}"/>   below are the lightning tags  <lightning:input type="checkbox" aura:id="box3" onclick="{!c.selectAll}"/>  <lightning:input type="checkbox" aura:id="boxPack" value=""                                                          onclick="{!c.checkboxSelect}"/>   controller  checkboxSelect: function(component, event, helper) {         // get the selected checkbox value           var selectedRec = event.getSource().get("v.value");         // get the selectedCount attrbute value(default is 0) for add/less numbers.          var getSelectedNumber = component.get("v.selectedCount");         // check, if selected checkbox value is true then increment getSelectedNumber with 1          // else Decrement the getSelectedNumber with 1              if (selectedRec == true) {             getSelectedNumber++;         } else {             getSelectedNumber--;         }         // set the actual value on selectedCount attribute to show on header part.          component.set("v.selectedCount", getSelectedNumber);     },      selectAll: function(component, event, helper) {         //get the header checkbox value           var selectedHeaderCheck = event.getSource().get("v.value");         // get all checkbox on table with "boxPack" aura id (all iterate value have same Id)         // return the List of all checkboxs element          var getAllId = component.find("boxPack");         // If the local ID is unique[in single record case], find() returns the component. not array            if(! Array.isArray(getAllId)){             if(selectedHeaderCheck == true){                  console.log('true');                 component.find("boxPack").set("v.value", true);                 component.set("v.selectedCount", 1);             }else{                 component.find("boxPack").set("v.value", false);                 component.set("v.selectedCount", 0);             }         }else{             // check if select all (header checkbox) is true then true all checkboxes on table in a for loop               // and set the all selected checkbox length in selectedCount attribute.             // if value is false then make all checkboxes false in else part with play for loop              // and select count as 0              if (selectedHeaderCheck == true) {                 for (var i = 0; i < getAllId.length; i++) {                     component.find("boxPack")[i].set("v.value", true);                     component.set("v.selectedCount", getAllId.length);                 }             } else {                 for (var i = 0; i < getAllId.length; i++) {                     component.find("boxPack")[i].set("v.value", false);                     component.set("v.selectedCount", 0);                 }             }          }        },


We know that p, q - odd primes such that $$(q - 1) | (p - 1)$$ and a is an integer such that $$ (a, pq) = 1 $$ How do we prove that $$ a^{p-1} \equiv 1 \mod pq $$

Assume that $p$ and $q$ are distinct add primes such that $p-1\mid q-1$. If $\gcd(a,pq)=1$ ,show that: $$a^{q-1} \equiv 1 \pmod{pq}$$   I have tried as follows: $$a^{q-1} \equiv 1 \pmod{q} \quad \text{and} \quad a^{p-1} \equiv 1 \pmod{p}$$ $$\implies a^{(q-1)(p-1)} \equiv 1 \pmod{q} \quad \text{and} \quad a^{(q-1)(p-1)} \equiv 1 \pmod{p}$$ $$\implies a^{(q-1)(p-1)} \equiv 1 \pmod{pq}$$ But then I am stuck - please help.


By default, latex beautifully places all display-math at the center of a line in the pdf file. I am preparing a document where I should start all display-math after one tab distance from the margin. The page will contain some nonmathematical text also. How can I do so?  The following example may clarify this question. Consider the following pdf-latex code:  \documenclass{article}  \usepackage{amsmath}  \begin{document}  There was a text like : aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  $$(a + b)^2 = a^2 + 2ab + b^2$$  There is another text : bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb  \end{document}   Now in the pdf file we get $$(a + b)^2 = a^2 + 2ab + b^2$$ in the middle of a line. But I need it in the after one tab distance from the margin.

I want all math blocks \begin{math} in my document to be intended automatically, like it's the case with \begin{itemize}.   Can anyone please give me a hint on how to do this? Thanks :-)


I finished the mesh but went i try to smooth it i got a rare black shadow :  3D viewport - no smooth    3D viewport -  smooth    Render - smooth    Render - no smooth

I've got a problem with my rendering! I'm trying to render some objects:    But, this is how it renders:    Can somebody help me out?


I have a card that basically says any creature with power or toughness = one is Unblockable, is it possible to buff them after declaring blockers? Thanks ahead of time for the info

I declare my attack with a 3/3 creature & then my opponent assigns a 1/1 creature to block.  Am I allowed to use the ability of an  (1 Green Mana - Target creature gains trample until end of turn) on my original 3/3 creature to make sure that, in addition to his creature dying, he receives 2 damage to himself as well?  Or would that give my opponent the chance to go back and assign a secondary blocker?


How can we find, if it exists, a closed form of $$A(x)=\sum_{n=0}^\infty x^{n^3}$$ I can't find any recursive relation for the coefficients ($a_m=1$ if $m$ is a cube $a_n=0$ otherwise). There is not much more to try (that I know of) so I'm completely lost here. Maybe there is no closed form expression. If we truncate the series $$\sum_{n=0}^mx^{n^3}$$ what can we do? Thanks!

I'm searching for the sum-formula (if exists) of the following power series: $$ \sum_{n=0}^{\infty}a^{n^l} $$ where $l=2,3,....$, and $|a|<1$.


I am using HP15 074tu laptop. Processor is Core i3 4005U 1.70 GHz *4. I am using UBUNTU 18.04.3 LTS and it is working fine.  I want to know if any other laptop with intel Pentium 1.10 GHz processor support UBUNTU 18.04.3 LTS  in same way as my present laptop.

I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the "official  requirements", the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.


I want the prompt strings to be one color, and the user input to show in another color. Date=input ("Date: ") Market=input ("Market: ") Price=input ("Price: ")

How can I output colored text to the terminal in Python?


I'd like to have the ability to bookmark questions I'm interested in.

I haven't been able to find my favorite questions in the official Stack Exchange Android app.  Looking at my accounts page gives nothing on them.


Let $t∈\Bbb N$ and let $x=6t+1, \:y=12t+1$ and $z=18t+1$. $x, y$ and $z$ are all primes and let $n=xyz$. Prove that  $a ^{n-1} \equiv 1 \pmod  n\;$ whenever $ a∈\Bbb Z$ and $\gcd(a,n) = 1$.  I have started using the Euler-Fermat Theorem since $\gcd(a,n)=1$. Giving $\phi (n)=(1296t^3) $ But unsure how to proceed?

Suppose k is an integer such that $6k + 1$, $12k + 1$, $18k + 1$ are primes. Show that $n = (6k + 1)(12k + 1)(18k + 1)$ is a Carmichael number.  This is a question on a past exam that I find difficulty to answer. Can anyone help?


I would like to use m23 to maintain a cluster of other Ubuntu machines, but unfortunately I can't find any documentation how to install m23 server on an Ubuntu machine. Neither are there any packages for Ubuntu.  Does anybody know how to install m23 on an Ubuntu machine?  UPDATE: The Debian source does not work for Ubuntu  The following packages have unmet dependencies:  m23 : Depends: apache-common ist aber nicht but is not going to be installed                       apache2.2-common ist but is not going to be installed   That is strange, because of the fact that apache is installed. What ever, trying to install the package leads to an error:  Package 'apache-common' has no installation candidate   I think, the problem is, that the packages in Ubuntu have a different name. Is that possible?

Occasionally, when I'm installing stuff, I get an error like the following:  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:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


I have been trying to install a font called Frutiger that I have in a zip file myfonts.zip using this . By the way, I'm on a Mac with MacTeX. The zip file has this tree structure:  myfonts/dvips/psfonts/frutiger.map myfonts/fonts/amf/frutiger/*.amf files myfonts/fonts/tmf/frutiger/*.tmf files myfonts/fonts/type1/frutiger/*.pfb files myfonts/fonts/vf/frutiger/*.vf files myfonts/tex/latex/psnfss/*.fd files   I have put the above files into /usr/local/texlive/texmf-local/. For example myfont.map is in /usr/local/texlive/texmf-local/dvips/psfonts/frutiger.map and so on.  Then I did these steps:  1. Run 'sudo -H mktexlsr' in the console. 2. Run 'sudo -H updmap-sys --enable Map=myfont.map' 3. Run 'sudo -H mktexlsr' again.   In my .tex file I added \usepackage{frutiger}. When I run my .tex file with PDFLaTeX I get this error:  ! LaTeX Error: File `frutiger.sty' not found.   I have tried to download and put frutiger.sty in the same folder as my .tex file but the new font is not showing up. I have tried the above steps several times but it does not seem like the font is being installed correctly. Last time I got this output in the console.  1. sudo -H mktexlsr mktexlsr: Updating /usr/local/texlive/2012/../texmf-local/ls-R...  mktexlsr: Updating /usr/local/texlive/2012/texmf/ls-R...  mktexlsr: Updating /usr/local/texlive/2012/texmf-config/ls-R...  mktexlsr: Updating /usr/local/texlive/2012/texmf-dist/ls-R...  mktexlsr: Updating /usr/local/texlive/2012/texmf-var/ls-R...  mktexlsr: Done.  2. sudo -H updmap-sys --enable Map=frutiger.map updmap is using the following updmap.cfg files (in precedence order): /usr/local/texlive/2012/texmf-config/web2c/updmap.cfg /usr/local/texlive/2012/texmf/web2c/updmap.cfg /usr/local/texlive/2012/texmf-dist/web2c/updmap.cfg updmap is using the following updmap.cfg file for writing changes: /usr/local/texlive/2012/texmf-config/web2c/updmap.cfg /usr/local/texlive/2012/texmf-config/web2c/updmap.cfg unchanged.  Map files not recreated.  3. sudo -H mktexlsr mktexlsr: ... Same as in step 1 ....   Do you have any clue on what could be wrong?  EDIT: Here is the content of frutiger.sty:  \NeedsTeXFormat{LaTeX2e} \ProvidesPackage{frutiger}     [2005/08/08 v1.2 Style file for Linotype Frutiger] \RequirePackage[T1]{fontenc} \RequirePackage{textcomp} \DeclareOption{lining}{\renewcommand*{\rmdefault}{lfrx}} \DeclareOption{oldstyle}{\renewcommand*{\rmdefault}{lfrj}} \ExecuteOptions{oldstyle} \ProcessOptions\relax %% %% End of file 'frutiger.sty'   Here is a minimal example of what I'm trying to do.  \documentclass{article} \usepackage{lipsum} \usepackage[T1]{fontenc} \usepackage{frutiger} \title{\textbf{Lorem ipsum dolor sit amet consectetur adipiscing elit}} \begin{document} \maketitle \section{Section I} \lipsum \end{document}   Adding \usepackage{frutiger} doesn't change the font more than that bold text becomes normal. I have checked the zip file and it seems to be okay as I can read the files with an editor. Also, I tried to force the map to be recreated using sudo -H updmap-sys --force --enable Map=frutiger.map. AFAIK there is no difference. Adding \fontfamily{pfr}\fontseries{m}\selectfont before any text makes the text look like Frutiger, I don't know if it actually is real Frutiger though. How do I find out?

Frequently there are questions about, how to manually install a font, what very often means “Type1 font”. So I thought, we should write a general answer about the several aspects to regard.  Beside the usual approach for  it seems, that for fonts further steps are necessary. What are these steps? Or better:  How to manually install fonts and their associated support files in TeX distributions?


I used to fit hurdle models with pscl::hurdle, I now use glmmTMB. The coefficients of the zero component of pscl::hurdle have the opposite sign of the coefficients of the zero-inflation component of glmmTMB. I understand that pscl::hurdle describes the probability of observing a positive count whereas glmmTMB describes the probability of observing a zero count. My question is the following: when presenting the results of a hurdle model, is one of these two methods the indicated one? If you use glmmTMB, should you multiply the coefficients by -1? Or you just need to specify which one is the described probability? Thanks

I wonder if there is a clear-cut difference between the so-called zero-inflated distributions (models) and so-called hurdle-at-zero distributions (models)? The terms occur quite often in the literature and I suspect they are not the same, but would you please explain me the difference in simple terms?


When I boot Ubuntu 18.04 it's not getting to the GUI interface. It's booting to a black screen with this error message.  /dev/sda5 contains a file system with errors, check forced. /dev/sda5: Inodes that were part of a corrupted orphan linked list found.  /dev/sda5: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.         (i.e., without -a or -p options) fsck exited with status code 4 The root filesystem on /dev/sda5 requires a manual fsck  Busybox v1.27.2 (Ubuntu 1:1.27.2-2ubuntu3.2) built in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs) _

I am running an HP pavilion dv6000 dual boot win7 and Ubuntu 12.04. (well, up until today).  After a reboot, the boot process drops to the BusyBox shell and I end up at the prompt:  BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs)   I've been researching others who have had this same problem, but haven't been able to find any of those solutions to work for me.  I tried the method described , and after the final command   mount -t ntfs-3g /dev/sda1 /root -o force   it does nothing and gives me another (initramfs) prompt.  I can boot to a live CD (USB) and get to a terminal, but it doesn't seem to do much good, as I can see the /dev/sda1 in the ls command, but it doesn't recognize it when I try to cd to it.  One more question: using the command fdisk -l how can I tell which mount point (sda1/sda2) is my windows partition and which one is Ubuntu?


If $y=x^{n-1}\ln (x)$, then prove that $xy_{n}=(n-1)!$  My Attempt: $$y=x^{n-1}\ln (x)$$ Differentiating both sides with respect to $x$, $$y_{1}= x^{n-1} \dfrac {1}{x} + \ln (x)\cdot (n-1)x^{n-2}$$  P.S $y_{n}$ denotes the $n^{th}$ derivative of $y$.


I wrote an extension method for strings which I'm using for logging the name, the value and the "source" of the string which calls the method. Source meens from which class or methods comes the string. For example Program.Main() or ClasXY.ToString() ... It looks like this  public static void LogMe(this string str, string memberName, string methodName) {     WriteToLog(DateTime.Now, memberName, methodName, str); }   Is it possible to get the name and the source of the string directly from the string object in my extension method? Something like this  public static void LogMe(this string str) {     string memberName = str.myName;     string methodName = str. mySource;     WriteToLog(DateTime.Now, memberName, methodName, str); }

Let me use the following example to explain my question: public string ExampleFunction(string Variable) {     return something; }  string WhatIsMyName = "Hello World"; string Hello = ExampleFunction(WhatIsMyName);  When I pass the variable WhatIsMyName to the ExampleFunction, I want to be able to get a string of the original variable's name. Perhaps something like: Variable.OriginalName.ToString()  Is there any way to do this?


I would be thankful for some advise on this issue:  I want to test whether the skewness for two distributions is significantly different from each other. (I know that skewness is often not the best parameter to compare distributions but it is necessary in this case to go with skewness. The choice of another parameter is not possible.)  I have a large dataset on two different groups of individuals. Group 1 contains about 1 million observation for a certain continuous variable. Group 2 only about 6000. Also, the variance of the observations of group 1 is only about 1/3 of that of group 2.  I would like to test whether the difference in skewness of the two population distributions is significant. However, I face the problem of huge sample size differences and also the differences in variances. Initially, I though about some  non-parametric permutation test but I wonder whether this is a good choice in my setting. I guess not...  I would appreciate any comments on how to appropriately design a test.  Thanks, Frank  Edit:  does not solve my problem. The author assumes a certain distribution and does not face an issue with different sample sizes.

How do you test for significant differences in skewness across two distributions of citation data, using R? I'm trying to compare the two power-law distributed histograms below (I'm just using histograms to visualize it, the data is not actually reduced to histograms). The sample sizes are 121 and 85 respectively. The skewness is very different (roughly 3 and 6 respectively), but how do I test if this difference is significant?


In X-Men: Days of the Future Past movie, there's a scene in Pentagon kitchen in which guards shoot bullet and Quicksilver puts his headphones ON to listen "Time in a Bottle" before playing as speed god.  Definitely, Sony Walkman of 70s can't play songs at 5000x. Can Quicksilver make other things faster? Or, it's a plot hole?

In Days Of Future Past, Quicksilver spends a lot of time playing with electronics.  In his famous tour de force scene in the Pentagon, he specifically puts his headphones on before running around the kitchen.  But why?  Does the music on his Walkman speed up with him as he uses it, or is it still operating at "normal" speed? Or indeed, does any electronic device that he touches speed up?


Consider a uniformly charged ring having   $$\frac{Q}{L} = \lambda$$  Now consider a pipe of radius $r$ surrounding the ring. Now I want to find out the field on a point on this pipe. Considering this pipe to be Gaussian surface. Using Gauss' Law we have  $$\frac{Q_{in}}{\epsilon_0} = \int \vec{E} \cdot d\vec{s}$$  Now considering the field over this pipe like Gaussian surface to be uniform (?) we have  $$\frac{Q_{in}}{\epsilon_0} =  \vec{E} \int d\vec{s}$$  $$  \vec{E} =\frac{Q_{in}}{\epsilon_0 \cdot \Delta {S}} $$  now substituting $\Delta S = 4 \pi^2 R_{ring} \cdot r_{pipe}$  $$  \vec{E} =\frac{Q_{in}}{\epsilon_0 \cdot 4 \pi^2 R_{ring} \cdot r_{pipe}} $$  Now coming to my question(s) regarding this answer:   Is this derivation and the answer correct If it is not where does this go wrong   What I have in mind is something along the lines of the following picture. Where I intend to calculate the field on the periphery of the blue torus which contains inside it a charged ring not a point on the axis.

I know we can find out the electric field using the electric field $$E=\frac{KQ}{R^2}$$ taking small element $dq$ and finding the electric field by integrating the value of $dE$ over the circumference which will be $$E=\frac{kxQ}{\sqrt {(a^2+x^2)^3}}$$ where $a$ is radius of ring and $x$ is distance of point $p$ on the axis of the ring. Can we find the same using the Gauss law?


Amateur question incoming so please bear with me.  Assumptions  If a black hole is born from a star going supernova, intuitively it should have the same or less mass compared to the star.  Black holes visually appear black because light cannot escape them due to their mass.  Questions   Wouldn't that imply that the light should not be able to escape the original star? Creating a black star that is visually indistinguishable from a black hole? If so, would it also mean that all stars capable of becoming black holes are themselves black stars before going supernova?

In the cases of black holes that form from supernova and collapse of a massive star, I understand that in most of these cases, the star loses significant amounts of mass from the explosion. Presumably, after this point as the remaining mass becomes more dense as it further collapses unto itself, it eventually becomes a black hole with gravitational force greater than that of its parent star. But, if gravity is based on mass, how can the black hole have greater gravitational force than the star from which it is formed?


This is a restart manga which i read few years back. The girl has a harsh life and a terrible fiancée because of this, she dies and wakes up again as her younger self. Determined to avoid the inevitable future, she starts to learn swordsmanship and becomes very good at it, sort of like a genius. Then in order to avoid the future she already experienced, she decides to join the army which a prince leads. She very quickly becomes acquainted with the top brass and fights with the prince. The setting is medieval with dukes and counts. The girl is a noble's daughter.

It’s a story of a female protagonist who has a harsh life. Just as she is about to die, she time travels back into her young self. To avoid the future she already lived, she decides to gets strong by learning swordsmanship. After a while, she joins the army under the command of a prince who wears an eye patch. She is quite OP, and helps the prince. It was kind of a medieval setting manga, with dukes and earls and count types. Time is when the use of sword and magic is prominent.


I have 9 W2K3 RDS (Terminal Services) CALs, if I upgrade to Windows server 2012 R2, Can I transfer/migrate the CALs to the new server?  Thank you,

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


I am a US citizen travelling to the UK for tourism. What kinds of documentation do I need to make sure that I have have with me when I get to passport control to make sure I get a visa on arrival?

Everything I've seen points to no (and I would love that to be true since applying for a visa online costs money) but I'm worried about getting refused due to the length of time I wish to stay, which is 6 months.  I went to university in the UK on a Tier 4 visa, but have never just been a tourist which is what I would like to do now. Since graduating, I have started working but am underwhelmed and would love to travel again. My original plan was Australia but now I would like to see the rest of the UK as well beforehand.  If I arrived with the following, would I be refused entry simply for not applying online?: an approved Australian work & holiday visa, a mini itinerary, bank statements for the last 6 months.


In my project, i read the text in NFC Tag, and i save it to String value. And if string value == given string , do something.  here is my code :   btn.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {              try {                 if(nfcTag==null){                     Toast.makeText(context, "Lütfen NFC Etiketini Okutunuz", Toast.LENGTH_SHORT).show();                 }else{                     nfcString = read(nfcTag);  // this is the part i get the text with read function. i already define nfcString as String.                 }             } catch (IOException e) {                 e.printStackTrace();             }              textViewName.setText(nfcString); // it is working fine !              String salak = textViewName.getText().toString();             // i created new String because, i tried to get textViewName.getText().toString() , i tought it should be work, but it didn't               try {                 // this is the if statement which doesn't work..                 if ( salak == getName(position) ) {                     // i also tried                      // nfcString  == getName(position)                     // nfcString.toString()  == getName(position).toString()                     // position thing is about spinner. i use spinner, it works fine also..                      btn.setText("Girdin!");                     yoklamaSend(getDersid(position));                  } else                     Toast.makeText(context, "DERS GİRDİSİ BAŞARISIZ", Toast.LENGTH_LONG).show();             }             catch (Exception ee) {                 ee.printStackTrace();              }         }     });   I can't understand why it is not working. NFC Tag is working fine, but whatever i do, i couldn't run if statement.  I get the NFC Tag Read code from sample of different app (which is working fine), here it is :      private String read(Tag tag) throws UnsupportedEncodingException {      Ndef ndef = Ndef.get(tag);     NdefMessage ndefMessage = ndef.getCachedNdefMessage();     NdefRecord[] records = ndefMessage.getRecords();     for (NdefRecord ndefRecord : records) {         if (ndefRecord.getTnf() == NdefRecord.TNF_WELL_KNOWN && Arrays.equals(ndefRecord.getType(), NdefRecord.RTD_TEXT)) {             try {                 byte[] payload = ndefRecord.getPayload();                 String textEncoding = ((payload[0] & 128) == 0) ? "UTF-8" : "UTF-16";                 int languageCodeLength = payload[0] & 0063;                 return new String(payload, languageCodeLength + 1, payload.length - languageCodeLength - 1, textEncoding);             } catch (UnsupportedEncodingException e) {                 Log.e("TAG", "Unsupported Encoding", e);             }         }     }     return null; }

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


I am trying to detect the device model and trying to do some operations based on that.   I do the code to detect the device model and manufacturer but for some reason its giving me a negative result.   Here's the code to detect the device model and manufacturer:  private Boolean isHTCone(){                  //For model and manufacturer both             String HTC_MODEL_MANUFACTURER = android.os.Build.MODEL+""+android.os.Build.MANUFACTURER;                 //If true then do something             Boolean isHTC = true;                 //My model name             String HTCModel = "HTC6500LVW";                 //For device model             String MyBuildModel = android.os.Build.MODEL;                 //For manufacturer                 String MyBuildManufacturer = android.os.Build.MANUFACTURER;             //Check for the condition             if(MyBuildModel==HTCModel){                  Log.i("Device Model is: ", android.os.Build.MODEL);                 return true;              }             else{                 Log.i("Device is not HTC One");                     return false;             }           }   Its always giving me a wrong value. Even when my device model is "HTC6500LVW", it's not accepting the if loop and is going to the else.  Can anyone tell me if I am doing something wrong here. I will really appreciate it.  Thanks in advance..:)


I know that if you type in "Pew Pew" lasers will fire; But are there anymore?

The recent update iMessage on iOS causes certain words to trigger screen effects.  Also, , and bring up an interface for adding these effects.   I've found the following associations between screen effects, and the messgaes that trigger them:   confetti: "congratulations", "happy birthday" fireworks: "happy new year"   What is the list of these?


How can I list the X clients which registered for a specific keyboard event (i.e. a key press; a shortcut thing). Those things are called passive key(board) grabs.  And the list should contain what that application is registered for what keysyms (with what modifiers).

Is there an application to know which key is bound by which process and therefore not usable in another application?


I would like to select multiple files non sequentially as in the illustration below...    On  I could simply hold down the Ctrl Key, navigate with Up and Down keys and hit the Space key to select or deselect a file.  But on mac if I hold down the Command key and hit Down arrow, it opens up the file (tested on images). and ctrl + down arrow does something weird with the windows..  Is there any way to select such thing without mouse (which is way slower of course..)?

I want to select non-consecutive items on a list, without using a mouse/trackpad - there should be no clicks involved.  In Windows and Linux (at least Ubuntu) an item can be selected using Space/ button, which, in combination with arrows and Ctrl key allows me to select multiple items in any environment (file manager, IDE etc.) - e.g.  Enter a directory -> hold Ctrl -> down arrow twice -> press Space -> down arrow twice -> press Space.  Now I should have items 1, 3 and 5 selected. Is there a way to do the same thing in OS X?  PS. Sorry for such a verbose description, but so far every answer I encountered advices using Command + Click, and this is something I don't want to do.


Photon is the quantum of light, i.e., energy comes in discrete level.  But EM energy is a function of frequency ($E=hf$).  And if frequency has a continuous spectrum, then energy level is continuous, instead of discrete. Doppler Effect tends to prove the argument of continuous frequencies.  Space is continuous, even though any length less than Planck's length has no meaning.  As stars and galaxies move in a continuous space, then Doppler continuously shifts (blue and red) the frequency of their radiated EM wave infinitesimally. The logical question would therefore be: is frequency continuous? Meaning, do we have frequencies like 1.012345 Hz, 100.098765 Hz, etc?

I'm just starting to learn physics and I have a question (that is probably stupid.)  I learned that energy levels that the bound electron can have are discrete. I also learned that when an electron transitions from one level to another, a photon with a specific wavelength (energy) is created and released into the wild.  My question is this: are there holes in the electromagnetic spectrum, values of frequency that the created photon can't possibly have?


How does Netflix's Daredevil fit into this Marvel movie order?   Captain America: The First Avenger Marvel One-Shot: Agent Carter (short; Iron Man 3 release) Iron Man The Incredible Hulk (campus rampage; overlaps w/ Iron Man 2) Iron Man 2 Marvel One-Shot: A Funny Thing Happened on the Way to Thor's Hammer (short; Captain America release) Thor (reference to Hulks experiment; overlaps w/ Iron Man 2) Marvel One-Shot: The Consultant (short; Thor release) Captain America: The First Avenger (end of movie; post credits) The Avengers (aka "Avengers Assemble") Marvel One-Shot: Item 47 (short; Avengers release) Iron Man Three Marvel One-Shot: All Hail The King (short; Thor: The Dark World release) Marvel's Agents of S.H.I.E.L.D Season 1, Pilot (ep. 1) to The Hub (ep. 7) Thor: The Dark World Marvel's Agents of S.H.I.E.L.D Season 1, The Well (ep. 8) to End of the Beginning (ep. 16) Captain America: The Winter Soldier (runs simultaneously with S.H.I.E.L.D, ep. 16) Marvel's Agents of S.H.I.E.L.D Season 1, Turn Turn Turn (ep. 17) to Beginning of the End (ep. 22) Guardians of the Galaxy Marvel's Agents of S.H.I.E.L.D Season 2, Shadows (ep. 1) to Making Friends and Influencing People (ep. 3)

I'm planning on re-watching the currently-released 5 Marvel films prior to seeing The Avengers.  Have Marvel released any sort of official viewing order?  Captain America: The First Avenger seems like the hardest one for me to place in order with the rest.  It takes place prior to the other films, but has the greatest number of references to the other films.  So should it be watched first, or last?  The rest of them are relatively clear, as they're chronological in the order they're released, with the possible exception of The Incredible Hulk and Iron Man 2 happening at the same time.


I had a couple of bouts of depression during my masters degree which resulted in very bad grades. Is it a good or bad idea to mention this in PhD applications to explain my grades?

This question is inspired by answers and comments to the question  on this website.  Suppose that an applicant to a graduate program suffered from some mental health issues during the completion of his previous degrees, and that this situation had a noticeable impact on his academic performance (for example, significantly lower grades or part-time status for one or several semesters).  Most graduate school applications have sections dedicated to providing explanations for such special circumstances, and it is of course strongly recommended that any applicant with unusual drops in academic performance should mention something about this in the special circumstances section. Otherwise, the admission committee will be left to guess what might have happened, which is likely to decrease the odds of being admitted (indeed, it seems a consensus that the more tangible information an admission committee has about an applicant, the more confident they can be about the fact that admitting him will be a sound investment).  Many answers/comments to the question  seem to recommend being very careful about revealing details on one's mental health conditions, given that there is still a lot of stigma attached to mental health conditions. However, in the case of PhD applications, not mentioning anything is not an option.  This then leads to the following question: If not making any mention of health issues is not an option (such as in PhD applications), how much details should one go into? To avoid stereotyping associated to any particular disease (such as depression=unreliable, learning disability=not smart) one could limit the description to "health problem", but could this lack of details be seen as suspicious and/or still a situation where the admissions committee will have to do guesswork?


My Java program isn't working!  Here is my code:   import javax.swing.JOptionPane; public class practice { public static void main(String[] args) {     String userName = "Eddie"; //username is Eddie     String passWord = "hI";    // passsword is hI     String name;    name = JOptionPane.showInputDialog("Whats your username? ");      if (name == userName)    JOptionPane.showMessageDialog(null, "Exepted!");    System.exit(0);   } }   Its supposed to ask for my username, and if I type "Eddie" it has to show message dialog "Accepted".But after I type "Eddie" the program closes instead!  Any suggestions?


This is a problem from Lee 17.12:     Suppose $M$ and $N$ are compact, oriented, smooth n-manifolds, and $F:M\rightarrow N$ is a smooth map. Prove that if $\int_M F^*\eta \neq 0$ for some $\eta \in \Omega^n(N)$, then $F$ is surjective.   I want to show the contrapositive, that non-surjective map implies $\int_M F^*\eta = 0$, and we know $\int_M F^*\eta = \text{deg}(F)\int_N\eta$. But I am not sure why non-surjectivity implies that $\text{deg}(F)=0$. Please help!   PS: I prefer to use techniques from Lee, as this is a problem there.

I am wondering how to prove that a non-zero degree map from $A \to A$ is surjective. For example, identifying $S^1 \subset \mathbb{C}$, we can take $f:S^1 \to S^1$ via $f(z) = z^k$ with $k\neq 0$. This is a map of degree $k$. How can I show that it is surjective?  Note that I am interested in general topological spaces, not the circle example in specific.


I have absolutely no intention of being sent to Azkaban. I could break out, of course - but what a waste of time, and frankly, I can think of a whole host of things I would rather be doing.   Dumbledore in the Order of the Phoenix   This, and many more instances, show us that Dumbledore was an immensely powerful wizard and was the only person Voldemort was afraid of.  However, Dumbledore chose to die at Snape's hand rather than suffering through the curse of Gaunt's ring. This would leave the impression that this immensely powerful wizard could not defend himself against Snape and a couple of other Death Eaters.  Since the truth didn't come out until the end, this would leave those who admired him with the belief that Voldemort's forces are far more powerful than they thought, disheartening them and making them less inclined to fight back (if Dumbledore couldn't fight them and win, how could I possibly do so?)  Why would he choose to do this?

So I was wondering and going back to Harry Potter recently and I was trying to figure out why Dumbledore put Marvolo Gaunt's Ring. The ring that Dumbledore had expertly deduced was an Horcrux was already heavily guarded by Voldemort in Little Hangleton and the only possible solution would be destroy it which Dumbledore eventually did with the Sword of Gryffindor.  It seems extremely careless and stupid of him to do such a thing. Why would the headmaster try a ring that would eventually kill him, as pointed out by Severus Snape?


How to uninstall ubuntu,i can't boot into ubuntu because i forgot my password.I don't have any window live cd,but have window vista and  xp,and have ubuntu server live cd.I have tried with grub loader,but still can't uninstall.Please someone help me.

I'm working on a Ubuntu system, and my client has completely forgotten his administrative password. He doesn't even remember entering one; however it is there.  I've tried the suggestions on the website, and I have been unsuccessful in deleting the password so that I can download applets required for running some files. Is there a solution?


Why is the link not working if the link is created with javascript? It only works if I make the link without the html() output  Not working  $(".link").on('click', function(){     alert('Hello'); });  $("#link").html('Link');

   Working  $(".link").on('click', function(){     alert('Hello'); });  Link

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


I cannot figure out the meaning of the logical OR ( || )  in this context. Rin = R1 +R2||R4  in this circuit  This was taken from this video  *at around 6:00 of the video

I'm reading some texts (single supply circuits collection) about circuits and I encounter the symbol ||.  What is the meaning of it?   For an example in a circuit about an op-amp circuit that provides gain i see in the "inverting" description:  Gain = -R2/R1  R3 = R1||R2  (I can't insert a schematic, circuit editor never starts)


I came across this problem when trying to stop a single quote (') being matched in a string.   Here is a snippet from a console session in Chrome. Params is the regex I'm trying to match (no single or double quotes should be allowed?). I would have expected the first two execs to find a match and the second two to fail due to the single quote in the text.  Suppose this raises two questions:   Why does the literal behave differently to the variable? Why does the third exec find a match when there should be no match on the single quote?   thanks  > params >  >> "^[a-zA-Z0-9 -_/&,()\[\];:+~.!\\]*$" >  >  > new RegExp(params).exec("some string") >> ["some string"] >  > new RegExp("^[a-zA-Z0-9 -_/&,()\[\];:+~.!\\]*$").exec("some string") >> null >  >  > new RegExp(params).exec("some string's") >> ["some string's"] >  > new RegExp("^[a-zA-Z0-9 -_/&,()\[\];:+~.!\\]*$").exec("some string's") >> null

I would like to create a String.replaceAll() method in JavaScript and I'm thinking that using a regex would be most terse way to do it.  However, I can't figure out how to pass a variable in to a regex.  I can do this already which will replace all the instances of "B" with "A".  "ABABAB".replace(/B/g, "A");   But I want to do something like this:  String.prototype.replaceAll = function(replaceThis, withThis) {     this.replace(/replaceThis/g, withThis); };   But obviously this will only replace the text "replaceThis"...so how do I pass this variable in to my regex string?


Consider the Banach space $C[a,b]$ with sup norm. For any fixed $x\in C[a,b]$ define $f_x(y)$ for any $y \in C[a,b]$ as follows: $$f_x(y)=\int_a^b x(t)y(t) \; dt$$ Show that $f_x$ is a bounded linear functional and compute $\|f_x\|$. I know that $f_x$ is a bounded linear functional and I am trying to show that $\|f_x\| = \|x\|_1$. How to make this? I know that $\|f_x\| \leq \|x\|_1.$ Thanks in advance.

Let $a$, $b$ be two arbitrary but fixed real numbers such that $a < b$, let $C[a,b]$ denote the normed space of all continuous real (or complex) valued functions defined on $[a,b]$ with the maximum norm, and let $f$ be the functional defined on $C[a,b]$ as $$f(x):= \int_{a}^{b} x(t) x_0(t) dt $$ for all $x$ in $C[a,b]$, where $x_0$ is a fixed element of $C[a,b]$.   Now $f$ is evidently linear and bounded. How to compute the norm of $f$? What is this norm?   And what is the norm of the bounded linear functional $g$ defined as follows: $$g(x):= \int_{a}^{(a+b)/2} x(t) \cdot dt - \int_{(a+b)/2}^{b} x(t) \cdot dt$$ for all $x$ in $C[a,b]$?


For around 1 week so far I've noticed screen tears and other graphical glitches.  I have only noticed them while browsing (in Chrome and Firefox), either while watching streams in flash or html5 format (Netflix, YouTube, twitch, even gifs) or scrolling through a big screen of text or images.  Here are some examples of the glitches I see:                This is really annoying, since it is constant and is very distracting.  The issue started on Ubuntu 16.04, and I did a fresh reinstall of Ubuntu 17.04 thinking this would solve it, but it didn't.  Currently I am running Ubuntu 17.04 64-bit version on an old Dell Studio 17. This is the gpu info:  lspci | grep VGA 02:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV730/M96 [Mobility Radeon HD 4650/5165]   I have tried 4 different kernel versions and the issue persists:    4.6.3   4.10.0   4.11.12   4.12.3     I don't know what to do to fix this, can you guys help me figure this out?

Scrolling through pages with lots of images cause a distortion about 2/3 down the screen. I've tried enabling/disabling smooth scroll and in chrome. I've also tried toggling compositor settings on device. I'm not really sure what the best bet solution here is. I'm at a loss, any help would be appreciated!  Here's a device info dump:   -Computer-   Processor        : 4x Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz Memory       : 8075MB (3935MB used) Operating System     : Ubuntu 16.04.1 LTS User Name        : nick-bbytes (Nick-BBytes) Date/Time        : Mon 06 Feb 2017 01:03:12 PM EST   -Display-   Resolution       : 3840x1080 pixels OpenGL Renderer      : Mesa DRI Intel(R) HD Graphics 5500 (Broadwell GT2) X11 Vendor       : The X.Org Foundation   -Multimedia-   Audio Adapter        : HDA-Intel - HDA Intel HDMI Audio Adapter        : HDA-Intel - HDA Intel PCH   -Input Devices-   Lid Switch Sleep Button Power Button AT Translated Set 2 keyboard Video Bus USB Optical Mouse USB-HID Keyboard USB-HID Keyboard ETPS/2 Elantech Touchpad HDA Intel PCH Mic HDA Intel PCH Headphone HDA Intel HDMI HDMI/DP,pcm       : 3= HDA Intel HDMI HDMI/DP,pcm       : 7= HDA Intel HDMI HDMI/DP,pcm       : 8= Asus WMI hotkeys USB2.0 HD UVC WebCam   -SCSI Disks-   ATA Micron_M600_MTFD


I'm new to jQuery and I've written this code in which I develop a form with some input buttons inside. There's a "cancel" button, which when clicked, I want the form to be removed.  Here's my code:  $(document).ready(function(){ $(".newIdea_Button").click(function(){      if (!new_idea_clicked)     {     $(document.body).append("<form>...some buttons here, one with the id cancel_idea_input</form>")     }  });  $("#cancel_idea_input").click(function(){     $('#new_idea_form').remove();  });   });   The thing is everything seems right to me but when I open the code in my browser (google chrome or firefox) nothing happens when I click the "cancel" button. but when I copy and paste the second function in the console part of google chrome, then the "cancel" button works! Can somebody please help me figure out what is wrong with my code?


We have a Buffalo AirStation WHR-HP-G300N as the main router. We also have an Asus RT-N53 router located one floor higher. I've set the Asus router to act as a repeater for the Buffalo. There is a problem with it though. My table isn't taking any benefit due to the repeater router. My phone gets a great signal though. Well, it gets it notwithstanding the extra router.   The Buffalo router is running DD-WRT and Asus is running on stock firmware.   The Asus router doesn't seem to be able to act only as a repeater device since it has to broadcast it's own SSID for both 2.4 GHz and 5 GHz frequencies. By the way, the tablet gets an excellent signal when connected to the SSID broadcasted by the Asus router.

If I use  two different router in the same network while both are running in the default router mode then we can access the setup page or setup interface from browser just by IP address of corresponding router. But when I use one of the router as repeater then I can only enter the setup page of the router which is running in router mode. Why router's setup page cannot be accessed when using the router as repeater? Now how can I change the settings of the router in repeater mode? The only way is to reset router with the hardware key then setup again.


I am grepping into /etc/os-release and then I want to store the output in a variable. I had made a conditional script where I was not needing a variable but now I need one. [[ ${$(grep ID_LIKE /etc/os-release)#*=} == 'arch' ]] && echo this || echo something   The output of grep ID_LIKE /etc/os-release   Looks like this ID_LIKE=arch   I want to get the thing after equal to sign, what is the most efficient way to do that? Thank you in advance.

I have a script that I am running inside a ubuntu container: #!/bin/sh  name=$(cat < /etc/os-release | grep "^NAME" | cut -d "=" -f 2)  if [ $name = "Ubuntu" ]  then    echo "This should return" else     echo "This is wrong" fi  I started the container by running: docker run -it -v $(pwd):/scripts ubuntu:latest /bin/sh /scripts/test.sh  The output I am receiving is "This is wrong" which is not right because I know that the output of $name is "Ubuntu" because my laptop is Ubuntu but I can't find a reason as to why this is going down the else route in the script? It does the same thing on my laptop outside the container.


Is there a multi-threaded cp command on Linux?  I know how to do this on Windows, but I don't know how this is approached in a Linux environment.

I'm currently having trouble with dd invoked with a sparse file as input (if) and a file as output (of) with conv=sparse. dd seems to be using one core of the CPU (Intel(R) Core(TM) i7-3632QM CPU @ 2.20GHz 4 cores + 4 Intel Hyperthreads) only (100 % of 1 core), so I've been wondering whether it's possible to parallelize dd. I've been    looking into info dd and man dd and there seems to built-in function in the version of corutils 8.23 checking sgp_dd from sg3-utils package (without understanding whether it suits my needs), but it doesn't seem to be able to handle sparse files dcfldd doesn't seems to have parallelization capabilities   AFAIK   an enhanced version/fork with internal handling of program parts in multiple threads (avoid context changes killing I/O performance) is preferred over a solution with GNU parallel running locally is preferred over a custom (possibly untested) code sniplet   How to avoid CPU being the bottleneck of an I/O intensive operation? I'd like to run the command on Ubuntu 14.04 with Linux 3.13 and handle sparse file disk images with it on any filesystem supporting sparse file (at least the solution shouldn't be bound to one specific file system).  Background: I'm trying to create a copy of 11TB sparse file (containing about 2TB data) on a zfs (zfsonlinux 0.6.4 unstable version, possibly buggy and the cause for the CPU bottleneck (eventually slow hole search)). That shouldn't change anything for the question of how to parallelize dd (in a very generic way).


Please start tracking views for all questions once per day.  This could be done database-economical, if only when a question is viewed at, there is a check, if today already is an entry in the views statistic, and only if not, then the actual viewcount is stored in that statistic. This way there will be maximal one entry for each question each day and only if there was at least one view today.  Once this is tracked, there could be made a statistic of how the views per day varies over time, which is relevant, if you want to see, in what era the question got most of its views (in the beginning, recently or due to a certain event...)

I'm not sure if this is possible architecturally, but when judging whether to set a bounty and how much it should be, it would be nice to see the impact based on our previous questions. If you're not visiting the site throughout the day, there is no way to tell how effective that bounty might be--particularly for increasing traffic. There is a similar question with adding and removing tags that increase the visibility in the right places, and the effect on views that may have.


I'm trying to format a number as brazilian currency, but I'm not sure what's going wrong.  function format2(n, currency) {     return currency + " " + n.toFixed(2).replace(^\s*(?:[1-9]\d{0,2}(?:\.\d{3})*|0)(?:,\d{1,2})?$/g, "$1,"); }

I would like to format a price in JavaScript. I'd like a function which takes a float as an argument and returns a string formatted like this: "$ 2,500.00"  What's the best way to do this?


While watching a collection of  I was wondering if there is an effective way of calculating the effect that a marinade might have on the nutritional value of meat being marinaded? While I am principally interested in 'calories' I would also like to, for instance, be able to calculate differences in fats and/or carbs. I am not so interested (at the moment) about vitamins or minerals.  The tools I have seen simply aggregate the total of ingredients, but in a marinade many of those ingredients are left behind (and therefore should not count as calories for the dish) but I have to believe (and other articles suggest as much) that there is 'an effect' but I am yet to find a manner for calculating that effect.  Several answers to  dance around the question, and as @Bikerboy389 suggests, maybe I'm "sweating the small stuff" here...still I would like to know. Especially where oils are concerned I'm thinking the effect might be more than just 'a little'

I'm planning on marinating my chicken legs with Tabasco sauce. I have read that a marinade should be one part lemon juice and 3 parts olive oil.  I'm going to be using two skinned chicken legs, lemon juice, extra virgin olive oil and Tabasco sauce  The reason I want to marinate the chicken legs is because I will be eating them on the go and wont have time to add the Tabasco sauce to them yet I still want them spicy.  So basically I'm wondering how many extra calories could I be talking for each chicken leg.  Thank you.


Currently, I am working on a latex document but unfortunately, black cells appear on the head of the table while using table generator.  \begin{table}[] \centering \caption{} \label{tab:my-table} \begin{tabular}{|c|c|c|c|c|c|} \hline \rowcolor[HTML]{B6DBF4}  \textbf{\begin{tabular}[c]{@{}c@{}}Time Shift\\ (hour)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}1.5 Rev V\\ (m/s)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}2.5 Rev V\\ (m/s)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}Time Shift\\ (hour)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}1.5 Rev V\\ (m/s)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}2.5 Rev V\\ (m/s)\end{tabular}} \\ \hline 2                                                                    & 15.1                                                               & 4.2                                                                & -2                                                                   & 14.6                                                               & 3.9                                                                \\ \hline 4                                                                    & 31.1                                                               & 8.7                                                                & -4                                                                   & 27.2                                                               & 7.9                                                                \\ \hline 6                                                                    & 47.7                                                               & 14.1                                                               & -6                                                                   & 39.3                                                               & 12.6                                                               \\ \hline 8                                                                    & 66.9                                                               & 19.3                                                               & -8                                                                   & 53.9                                                               & 17.8                                                               \\ \hline 10                                                                   & 85.9                                                               & 24.9                                                               & -10                                                                  & 67.1                                                               & 22.3                                                               \\ \hline 18                                                                   & 224.4                                                              & 59.8                                                               & -18                                                                  & 113.1                                                              & 55.9                                                               \\ \hline \end{tabular} \end{table}   Any idea?  UPDATE1: table code is added

Currently, I am working on a latex document but unfortunately, black cells appear on the head of the table while using table generator. Any idea?


My PS4 is on the initial startup screen (when you first buy the system) and the controller doesn't connect to the system. I've tried resetting the controller and using different wires, but still nothing. The controller only connects to the system on safe mode (with any wire), but after I choose an option, it goes back to the initial startup screen and the controller doesn't work anymore. Does anyone know how to fix this?

I was playing my PS4 two days ago and then packed it up with two controllers that were both connected to this PS4.   I got to where I was going, set everything up and now the controllers won't connect. They show pulsing orange when they plug in, but when I hit the PS Button to connect, it blinks white 1-2 times and goes back to orange.   I have tried resetting them both.  Can anyone help?


Trying to get a post to show up at  but am getting 404 instead. An example of what the page should look like is: . When I do a search, it shows up as an excerpt in the results. Just can't get the template single-supporter.php to trigger for some reason. I have set up the post type (And corresponding taxonomy) exactly like every other post type and taxonomy.  I have flushed the cache and CDN.  I don't have a live server testing environment for this but the same exact code works on localhost. Because it is live with heavy traffic, I am reluctant to turn on debugging features that would show on front end.  Register post type code in functions.php    $labels = array(     'name' => _x('Supporters', 'post type general name'),     'singular_name' => _x('Supporter', 'post type singular name'),     'add_new' => _x('Add New', 'supporter'),     'add_new_item' => __('Add New Supporter'),     'edit_item' => __('Edit Supporter'),     'new_item' => __('New Supporter'),     'all_items' => __('All Supporters'),     'view_item' => __('View Supporter'),     'search_items' => __('Search Supporters'),     'not_found' =>  __('No supporters found'),     'not_found_in_trash' => __('No supporters found in Trash'),      'parent_item_colon' => '',     'menu_name' => 'Supporters'    );   $args = array(     'labels' => $labels,     'public' => true,     'publicly_queryable' => true,     'show_ui' => true,      'show_in_menu' => true,      'query_var' => true,     'rewrite' => true,     'capability_type' => 'post',     'has_archive' => true,      'hierarchical' => true,     'menu_position' => null,     'taxonomies' => array ('beer','category'),     'supports' => array('title','editor','author','thumbnail','excerpt','trackbacks','custom-fields','page-attributes','revisions','comments','post-formats')   );    register_post_type('supporter',$args);   Register taxonomy code in functions.php     // Add new taxonomy, make it hierarchical (like categories)   $labels = array(     'name' => _x( 'Supporters', 'taxonomy general name' ),     'singular_name' => _x( 'Supporter', 'taxonomy singular name' ),     'search_items' =>  __( 'Search Supporters' ),     'all_items' => __( 'All Supporters' ),     'parent_item' => __( 'Parent Supporter' ),     'parent_item_colon' => __( 'Parent Supporter:' ),     'edit_item' => __( 'Edit Supporter' ),      'update_item' => __( 'Update Supporter' ),     'add_new_item' => __( 'Add New Supporter' ),     'new_item_name' => __( 'New Supporter Name' )   );    register_taxonomy('supporter',array('beer','post'),     array(     'hierarchical' => true,     'labels' => $labels,     'show_ui' => true,     'query_var' => true,     'rewrite' => array( 'slug' => 'supporters-bp' )   ));

I'm developing a Custom Post Type plugin, which works fine in dev. Now that I've moved it to production, I'm getting a 404 when I try to display the template for the CPT.   So, two questions:  1- Is there some mechanism to determine the path WP took to get through the hierarchy?  2- Why wouldn't it just give me the single or index page?  I've dumped $wp_query and a stacktrace at the end of the 404. Here's part of what I found:  [query] => Array     (         [page] =>          [pagename] => refletters/proximity     )  [request] => SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND (wp_posts.ID = '0') AND wp_posts.post_type = 'page'  ORDER BY wp_posts.post_date DESC  [posts] => Array     (     )  [queried_object] =>  [queried_object_id] => 0   And the stack trace:  2013-04-27 22:16:41 - 24.52.197.40 - TRACE - index.php - 404.php[39] -      wordpress/wp-content/themes/notoriousconsultant/404.php[39] - aaLog->logtrace     wordpress/wp-includes/template-loader.php[50] - include     wordpress/wp-blog-header.php[16] - require_once     wordpress/index.php[17] - require   Thanks for your help.


In Einstein's Photon Theory of Light, he proposed that light consists of distinct chunks or distinct packets of energy called photon and the energy of a photon is given by : $E=hν$ where $ν$ is the frequency of light. I have a question. Einstein said that light is made up of particles called photons. But at the same time he is also saying that $E=hν$. In this equation, there is frequency which is clearly a characteristic of a wave. How is he associating property of a wave to a particle? How can a photon have frequency? It is a particle, right? It doesn't make sense. It is like he is combining wave and particle to create hybrid between the two. Can someone please explain this?

Consider the question, .  The answers say, "an elementary particle" and not much else. They don't actually answer the question. Moreover, the question is flagged as a duplicate of,  – the answers there don't tell me what a photon is either. Nor do any of the answers to  mentioned in the comments. When I search on , I can't find anything useful. Questions such as,  look promising, but bear no fruit.  say things like, "the photon is an excitation of the photon field." That tells me  nothing. Nor does the , which says:     The photon is the quantum of the electromagnetic four-potential, and therefore the massless bosonic particle associated with the electromagnetic force, commonly also called the 'particle of light'...   I'd say that's less than helpful because it gives the impression that photons are forever popping into existence and flying back and forth exerting force. This same concept is in the  too - but it isn't true. As , "Virtual particles only exist in the mathematics of the model." So, who can tell me what a real photon is, or refer me to some kind of authoritative informative definition that is accepted and trusted by particle physicists? I say all this because I think it's of paramount importance. If we have no clear idea of what a photon actually is, we lack foundation. It's like what :     Photons seem to be one of the foundation ideas of quantum mechanics, so I am concerned that without a clear definition or set of concrete examples, the basis for understanding quantum experiments is a little fuzzy.   I second that, only more so. How can we understand pair production if we don't understand what the photon is? Or the electron? Or the electromagnetic field? Or everything else? It all starts with the photon.   I will give a 400-point bounty to the least-worst answer to the question. One answer will get the bounty, even if I don't like it. And the question is this:    What exactly is a photon?


Why is this code:  #include <iostream> struct S {     unsigned char a:6, b:6, c:6, d:6; };     int main(int argc, char *argv[]) {     std::cout << sizeof(S);     return 0; }   returning 4? Shouldn't it have a size of 4 x 6 = 24b = 3B? In contrast, this code:  struct S { unsigned char a:4, b:4, c:4, d:4; };   returns a 2, while this one:  struct S { unsigned char a:4, b:4, c:4, d:4, e:4, f:4; };   returns a 3...

Why does the sizeof operator return a size larger for a structure than the total sizes of the structure's members?


I tried to install sudo with apt install sudo but it won't work. I got these errors: E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied)   E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?  I am always required to give root access whenever i want to open some files in the terminal but i can't do that without sudo

This seems to be a chicken-egg problem. The most common task using sudo is installing and removing software.  sudo apt-get purge <appname>   But sudo itself can be removed.  sudo apt-get purge sudo # Do not run this command on production computers!   This is where the fun comes  ubuntu@ubuntu:~$ sudo bash: /usr/bin/sudo: No such file or directory   Although it's obvious that no person in his right mind will purge sudo (other than me), someone can be fooled to run this command (not directly, in its hex mode, or whatever it's called) or a person could SSH in disguised as tech guru and do the mess.  So is there a way of reinstalling sudo?


Stack Overflow is a Q&A tool imposing a certain structure in the way the dialog is handled between OP and the rest of the community.  But let's say a bunch of site users are following a  or  class and they want to talk about course homework or other matters. What's the best way to open discussion about class topics?

I would like to ask a question about Java that doesn't have a specific answer. It's a question to see what people think and to share their opinion.    Will Stack Overflow tolerate this, or is there another Stack Exchange resource where I may ask a question like this?


I'm looking at buying a new 18-55mm lens as the one that came with my 4000D doesn't have image stabilisation, which I really need. It seems like canon have made many EF-S lenses over time that all seem to have the same features.  I won't be recording video on this camera so having silent auto-focus isn't important to me.

I am planning to buy a new Canon camera body, and am wondering whether to just get the body, or to get the standard 18-55mm lens as well.  I already have such a lens, which I think came with the EOS 600D camera that I bought about 5 years ago, but it might actually be older than that.  (It is marked "CANON ZOOM LENS EF-S 18-55mm 1:3.5-5.6 IS II".) Have these lenses improved significantly over that timescale?


I just install ubuntu 13.10, I hope I can make my laptop, which is connected to internet by a cable, as a WiFi router.  I just googled for some ideas, I find a huge access to this topic , I read several articles and I tried several ways , but non of them succeed .   What i need is just some steps to do either by terminal or by creating a new wifi network.   I usually use my phone , android Samsung ACE to check if my new network works properly .  Thanks very much , any suggestion would be highly appreciated .

My desktop has a fast wired connection and I would like to set up a sort of "wifi hotspot" that allows mobile devices to connect to my pc and share this fast connection. How would I go about doing this?


I am trying to mount a raw image in my ubuntu VM but it returns a mismatch type error:  root@ubuntu:~$ sudo kpartx -a -f -v xenial-server-cloudimg-amd64-disk1.img root@ubuntu:~$ cd /dev/mapper/ root@ubuntu:/dev/mapper$ ls control  ubuntu--vg-root  ubuntu--vg-swap_1 root@ubuntu:/dev/mapper$ losetup NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE /dev/loop0         0      0         0  0 /home/usera/xenial-server-cloudimg-amd64-disk1.img root@ubuntu:/dev/mapper$ sudo mkdir /tmp/foo root@ubuntu:/dev/mapper$ mount /dev/loop loop0         loop2         loop4         loop6         loop-control loop1         loop3         loop5         loop7 root@ubuntu:/dev/mapper$ sudo mount /dev/loop0 /tmp/foo/ mount: wrong fs type, bad option, bad superblock on /dev/loop0,        missing codepage or helper program, or other error        In some cases useful info is found in syslog - try        dmesg | tail or so.   I read up online and follow the instruction but the instruction said I should have a loop0s1 under /dev/mapper folder instead. But I don't see anything under /dev/mapper. Is there anything I did wrong?  Thanks  Edit:  root@ubuntu:~$ file xenial-server-cloudimg-amd64-disk1.img xenial-server-cloudimg-amd64-disk1.img: QEMU QCOW Image (v2), 2361393152 bytes  root@ubuntu:~$ sudo fdisk -l xenial-server-cloudimg-amd64-disk1.img Disk xenial-server-cloudimg-amd64-disk1.img: 276.3 MiB, 289734656 bytes, 565888 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes

I have a QEMU virtual machine that uses a qcow2 disk image.  How can I mount its filesystem without powering on the virtual machine?


For a CV I want my bib-items to be sorted with respect to the year with the most recent item appearing first. In addition I have to use a certain style sheet, the Unified Style Sheet for Linguistics. The sorting option seems to do what I want but it does not do so when combined with the style. The order of output should be:  [1] Müller, 2018 [2] Müller & Ørsnes, 2015 [3] Müller, 2013   Is it possible to generate numbered output, e.g. as above with [1], [2], [3]?  The style files are here:   \documentclass{article}  \usepackage{filecontents}   \usepackage[ natbib=true, style=biblatex-sp-unified,     %citestyle=numeric,     citestyle=sp-authoryear-comp,     sorting=ydnt, ]{biblatex}   \begin{filecontents}{bibliography.bib}  @book{MOeDanish, Address = {Berlin}, Author = {Stefan Müller and Bjarne Ørsnes}, Publisher = {Language Science Press}, Series = {Empirically Oriented Theoretical Morphology and Syntax}, Title = {{Danish in Head-Driven Phrase Structure Grammar}}, Year = {2015}}  @book{MuellerHPSG3, Address = {Tübingen}, Author = {Stefan Müller}, Edition = {3}, Number = {17}, Publisher = {Stauffenburg Verlag}, Series = {Stauffenburg Einführungen}, Title = {{Head-Driven Phrase Structure Grammar: Eine Einführung}}, Year = {2013}}  @book{MuellerLFGphrasal, Address = {Berlin}, Author = {Stefan Müller}, Booktitle = {Phrasal Constructions, Derivational Morphology, Constituent Structure and (Cross-Linguistic) Generalizations: {A} Discussion of Template-Based Phrasal {LFG} Approaches}, Publisher = {Language Science Press}, Series = {Conceptual Foundations of Language Science}, Title = {Phrasal Constructions, Derivational Morphology, Constituent Structure and (Cross-Linguistic) Generalizations: {A} Discussion of Template-Based Phrasal {LFG} Approaches}, Year = {2018}}    \end{filecontents}   \bibliography{bibliography}  \begin{document}   \begin{refsection}  \nocite{MOeDanish,MuellerHPSG3,MuellerLFGphrasal}  \printbibliography[heading=none,notkeyword=this]  \end{refsection}    \end{document}

I haven't had a lot of experience with biblatex so far and I decided to use the numeric style for citations in the text. However, the authoryear style for the bibliography is much nicer. I know, I can't actually combine numeric citestyle with authoryear bibstyle.  That brings me to my question: How can I achieve using the numeric citestyle and the formatting of authoryear in the bibliography?


I run the following command:-  get-spdeletedsite   which showed me a list of deleted site collections, now i run the following to remove the deleted sites as follow:-  remove-spdeletedsite 032**********   but i got the following error :-     unable to find the specified path     now i try  to run the following script :-  Add-PSSnapin Microsoft.SharePoint.PowerShell $CorruptSites = "http://***/sites/***"  Function DeleteCorruptSite { param($CorruptSite) Write-Host $CorruptSite : -foreground red $site = Get-SPSite $CorruptSite $siteId = $site.Id $siteDatabase = $site.ContentDatabase  $siteDatabase.ForceDeleteSite($siteId, $false, $false) Write-Host --Deleted from Content DB -foreground green } foreach ($CorruptSite in $CorruptSites) {  DeleteCorruptSite $CorruptSite }   but i got the following exception also:-  http://***/sites/*** : Get-SPSite : Cannot find an SPSite object with Id or Url: http://***/sites/***. At C:\Users\***\Desktop\1.ps1:10 char:9 + $site = Get-SPSite $CorruptSite +         ~~~~~~~~~~~~~~~~~~~~~~~     + CategoryInfo          : InvalidData: (Microsoft.Share...SPCmdletGetSite:SPCmdletGetSite) [Get-SPSite], SPCmdletPipeBindException     + FullyQualifiedErrorId : Microsoft.SharePoint.PowerShell.SPCmdletGetSite   so can anyone adivce on this please ?i remember that i tried to remove this site collection using the central administration UI. but it raised an exception and the site content database and site collection administrator became empty,, so is there a way to remove corrupted deleted site collection ?

Im trying to rename a site collection by changing the url by using this PowerShell   $site = get-spsite -identity http://xxx:9000/sites/SCOne $site.Rename("http://xxx:9000/sites/SCOneNew")   I got this message     Exception calling "Rename" with "1" argument(s): "Cannot rename a site collection     with recycled items. Empty the site recycle bin of site collectio   The recycle bin is empty now but I still can't rename and I get the same message.   I have tried this PowerShell to get count of items in recycle bin    $site = get-spsite http://xxx:9000/sites/SCOne Write-Host $site.RecycleBin.Count.ToString();   but it says     you cannot call a method on a null-valued expression


I found apostrophe use differs among association titles—"American Translators Association" has no apostrophe, whereas  "Iraqi Translators' Association" does.  Therefore, I need to make sure which one of the following is correct:  "Iraqi Translators Association" or  "Iraqi Translators' Association"?  .

In a recent thread, it was recommended that Academies' Trust be written as I just have done:      Academies' Trust. Normal possessive apostrophe rules apply.   If I accept this traditional style, I might well end up writing something like:     Academies' Trusts include the Academies Enterprise Trust, the Leigh   Academies Trust, the Aspirations Academies Trust, and The Kemnal   Academies Trust.   Should consistency of style override traditional apostrophe rules in this case?