In Star Wars, I find it weird that droids are not speaking the common language, but instead do beep-boops. And what is weird of that is that even then everybody seems to understand perfectly what they are saying. (or at least the protagonists) Is it ever explained why even if droids talk in beep boops the common man seems to be capable of understanding the droid language? Like if the 'droid language' is a language just like spanish or french in our world?
In all the Star Wars movies, R2D2 just boops and beeps his way around. And everyone understands him perfectly, though he is obviously not speaking Basic.  How do people understand him - is there like an astromech language? If so, then would one have to learn it, or is it comprised of feelings and emotions (expressed in beeps), essentially making a tonal language?  If I may be permitted to use an example from the prequels without too many lynch mobs forming, Anakin Skywalker converses frequently with Artoo while in the Naboo fighter, but he couldn't have had much schooling at the age of eleven, especially because he was a slave.  So how would people, Anakin especially, be able to understand astromechs?
Are there any massless (zero invariant mass) particles carrying electric charge?  If not, why not? Do we expect to see any or are they a theoretical impossibility? My wife, two kids and I will be traveling in Ireland and the UK Nov. 1st through 21st. We're flying into and out of Dublin. Our plan is to do a clockwise tour: Fly into Dublin -> Belfast -> Scotland -> England/London -> Back to Dublin to fly home.  We've been planning to rent a car when we land in Dublin (doing just things outside Dublin at the start of the trip) and have a car all the way until London, then turn in the car and take a train/ferry to get back to Dublin before flying home.  However, reading through the car rental section of Rick Steve's 2012 Ireland book is causing us to question if this is the right plan.  He says (p. 480):     If your trip covers both Ireland and Great Britain, you're better off   with two separate car rentals, rather than paying for your car to ride   the ferry between the two islands. On an all-Ireland trip, you can   drive your rental car from the Republic of Ireland into Northern   Ireland, but be aware of drop-off charges ($75-150) if you return it   in the North.   So it seems like he recommends against doing one car rental for both islands, but he also recommends against renting in the Republic of Ireland and returning it in Northern Ireland (our other option for our current itinerary).  So we're not sure which is best here.  A few questions about this:   If we do one car rental all the way from Dublin to London, will there be a similar $75-$150 fee? Is there an easy place to return a car on the Northern Ireland side of one of the Northern Ireland -> Scotland ferries, and an easy place on the Scotland side to rent a car?  We'd like to minimize the number of buses/whatever we need to take between car rentals since we'll be lugging around car seats for both of our children (on top of carrying them and our luggage). Will one way be significantly cheaper than the other?  Besides the basic cost of taking the car on the ferry and the drop-off charges, our credit card will cover insurance in Scotland/England but not in Ireland, so we could potentially get a better rental rate by renting a second vehicle once we're on Great Britain. Although, I know you often get a better rate when keeping a car rental for longer, so that may negate any benefit from the credit card covering the insurance. Restricing domains for universal and existential quantifiers I am currently using Rosen's "Discrete Mathematics and Its Applications" (7th ed.) for my discrete mathematics course. We recently talked about quantifiers, more specifically the universal and existential quantifier. What confuses me is when we started talking about restricting the domain (i.e. instead of all real numbers, only all real positive numbers), where does the conditional statement come from when restricting the domain of a universal quantifier and where does the conjunction come from when restricting the domain of a existential quantifier?  This link did help:   However, the part that confuses here is how are the domains restricted in the answer given in the link above? When signing in with Google (OAuth), it shows a list of accounts it already knows about. How can I remove some accounts from this list?    I know I can nuke all of them by deleting all cookies, but I'd prefer to remove one account that I don't want there, rather than all of them.  There used to be an ability to edit this list in the older version of this screen, but in 2018 redesign Google has removed [×] buttons next to the accounts. Get last n lines of a file, similar to tail I'm writing a log file viewer for a web application and for that I want to paginate through the lines of the log file.  The items in the file are line based with the newest item at the bottom. So I need a tail() method that can read n lines from the bottom and support an offset.  This is hat I came up with: def tail(f, n, offset=0):     &quot;&quot;&quot;Reads a n lines from f with an offset of offset lines.&quot;&quot;&quot;     avg_line_length = 74     to_read = n + offset     while 1:         try:             f.seek(-(avg_line_length * to_read), 2)         except IOError:             # woops.  apparently file is smaller than what we want             # to step back, go to the beginning instead             f.seek(0)         pos = f.tell()         lines = f.read().splitlines()         if len(lines) &gt;= to_read or pos == 0:             return lines[-to_read:offset and -offset or None]         avg_line_length *= 1.3  Is this a reasonable approach?  What is the recommended way to tail log files with offsets? Product of binomial coefficient as a basis Android Debugging, how? error: Unable to find vcvarsall.bat python: restarting a loop Ideals in ring of continuous functions $\mathcal{C}[0,1]$ ... NBHM- Algebra I would like to compile all questions I have encountered with Ideals in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions and ask if there are any gaps.  Question is to see if :     the ideal $\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=0\}$ is maximal ideal in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions.   What I have done so far is :  consider $\eta :\mathcal{C}[0,1]\rightarrow \mathbb{R}$ where $f\rightarrow f(0)$   $Ker (\eta) = \{ f\in \mathcal{C}[0,1] : f(0)=0\}$  I could see that for each $r\in \mathbb{R}$, I would set $f$ such that $f(x)=x+r$  So, $\eta$ is surjective.  So, I would get $\mathcal{C}[0,1]/\mathcal{I}\cong \mathbb{R}$  As $\mathbb{R}$ is a field so ia the quotient $\mathcal{C}[0,1]/\mathcal{I}$ which means that $\mathcal{I}$ is an ideal in $\mathcal{C}[0,1]$.    Now Another Question on same idea :  Question is to see if :     the ideal $\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=f(1)=0\}$ is maximal ideal in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions.   I thought of using same ideas as above but i am unable to choose perfect $\eta$  I believe that this is not even a prime ideal..  I set  $f(x)=x$ and $g(x)=x-1$ and consider $f(x)g(x)=(x)(x-1)$ then,   $(fg)(0)=f(0)g(0)=0.(-1)=0$   $(fg)(1)=f(1)g(1)=1.0=0$  So, $fg\in \mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=f(1)=0\}$ but the neither $f$ nor $g$ is in $\mathcal{I}$.    I have two questions:   I see that $0$ does not play any role in the question $\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=0\}$ I mean I would have same case if i replace $0$ by any real number.  So, I would like to say that $$\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(r)=0\}$$  is a maximal ideal in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions.  And one more thing I would claim is that      If the collection $\mathcal{I}$ is such that all elements of $\mathcal{I}$ has more than $1$ common zero then $\mathcal{I}$ is not a maximal ideal and not even a prime ideal..   I would like to learn more about this kind of ideals in $\mathcal{C}[0,1]$.  I would be thankful if some one can assure that what  have done is sufficient to conlcude what i have concluded and I would be thankful if some one can suggest some material to read regarding this.  Thank you Is the solution to a question regarding four smaller masses on a rotating hollow sphere accurate? I was doing the question :     A uniform 8.40-kg spherical shell, 50.0 cm in diameter has four small   2.00-kg masses attached to its outer surface and equally spaced around it. This combination is spinning about an axis running through the   center of the sphere and two of the small masses (see ). What friction torque is needed to reduce its angular speed   from 75.0 rpm to 50.0 rpm in 30.0 s?   I understand how to get $\alpha$, and how to get $\tau$ from $I$ and $\alpha$. What I do not understand is their computation of the moment of inertia. The question did not provide any information regarding the shapes of the masses, but the solution (which writes $I=\frac{2}{3}MR^2+2mR^2$) seems to assume that the masses are point particles. Thus, the two masses along the rotational axis have a moment of inertia of 0 ($r=0$), and each of the other two masses has a moment of inertia of $I=mr^2 =mR^2$, where $R$ is the radius of the sphere and $r$ is the distance from the axis.  But why are the masses considered to be point particles? I wanted to use the parallel-axis theorem to determine the moment of inertia about the rotational axis; not knowing the shape of the masses made this impossible, since I couldn’t find the moment of inertia about the CM. If I knew $I_{CM}$, then couldn’t I use $I_{axis}=I_{CM}+mR^2$ for the two masses not on the rotational axis and $I_{CM}$ for the two that are? That would make $I_{total}=\frac{2}{3}MR^2+4I_{CM,\:mass}+2mR^2$ Would that not be a better way of solving this problem? If $f \in \operatorname{Hol}(D)$, $f(\frac{1}{2}) + f(-\frac{1}{2}) = 0$, prove that $|f(0)| \leq \frac{1}{4}$ 8 AWG solid EGC in raceway for 100 amp subpanel I'm adding a 100 amp subpanel to my detached garage and have a question about the EGC I've already pulled through the underground LFNC-B raceway. Taking the advice from a similar post on this forum, I decided to use a 8 AWG bare solid copper conductor for my EGC in the underground raceway back to the main house. The other 3 conductors are 3 AWG THWN-2 stranded copper. I did double check the NEC tables to ensure these were appropriately sized for the underground feed portion of my run and ensured the conduit fill was less than 40%. What I failed to realize though (until after I won the good battle of pulling this set though the raceway) was that there is a section in the NEC that prohibits the use of solid conductors 8 AWG or larger in raceways: &quot;310.3 Stranded Conductors. Where installed in raceways, conductors of size 8 AWG and larger shall be stranded.&quot; Dangit! Now I'm questioning why I didn't just use insulated green THWN-2 - it would have made my pull much easier! Rookie mistake. So how bad have I goofed up here? Let's say the inspector fails to call this out. Is this a safety issue? What's the rationale for the rule anyways? To prevent numskulls like myself from trying to pull larger gauge solid wire through a raceway and possibly damaging the other conductors? Or is there more to it? Interestingly, there seem to be several exceptions in the NEC that do allow for using 8 AWG solid EGC in raceways (690.46 for Array Equipment Grounding Conductors for example). I'm just trying to get a feel for the severity of this goof-up and if it's worth fixing if not required by the inspector. Any feedback from the experts would be much appreciated! At the end of the scene in the cemetery in GoF, the spirits who emerged from Voldemort's wand tell Harry to go grab the trophy (which, of course, was a portkey that took Harry and Cedric from the maze to the cemetery), and that the trophy portkey would take Harry back to Hogwarts.  Why would the portkey do that?  Are all the portkeys 2-way?  If possible, I would prefer as much of the answer based on canon (or JKR) as feasible My case here is that I was writing something for school, and my teacher explained an error which I really can't see. She referred to articles about &quot;dangling participles&quot;, which was previously unknown to me. I find it hard to relate the examples I've found about it to my situation. So this is a text I've written and the bold part is where the problem arises: (You could read only the bold part if you please)  Wandering, and lost in his thoughts, there is a deep despair occupying the mind of this man. He is barely aware of his surroundings, except for those few moments when the loud blissful voices break through the protective barriers, developed by his immense sadness and grave frustration, into his mind. ”How can they all possibly be so happy?” he thinks to himself. Staring blindly, with his head low, as he walks in a slow pace, whispering ”Mary, Mary, my Mary,” over and over again. Yesterday was her funeral. She had passed away from a severe type of cancer, at a relatively young age. It was his wife. They had been together since high school and were greatly attached to each other. Having spent nearly half his life by her side, we cannot but imagine his grief. Indeed, he could hardly picture a life without her. So, alone he roams in the midst of all the seemingly incessant cheering and noises, drowned by his sorrow.  Her comments on that part was:  we is slightly out of place here – see my comment below These few sentences are about him and his emotions, so ‘we’ seems out of place. If the sentence starts: ‘Having spent nearly half his life by her side’, the reader expects it to continue: ‘he’. After all we have not spent half our lives by her side.  Is she right? If so, could anyone try to explain why? Use of "would" for subjunctive phrases This has been bugging me for some time; I tried to look for previous questions here but my language tools may not be sharp enough to phrase my query correctly so please forgive me if this has already been posted here.  Speakers of English as a foreign language tend to incorrectly use the word "would" when using some particular subjunctive constructs. Here is  (this time presumably by a native English speaker):     If that would happen, you won’t be alone.     (One correct version being "If that happens, you won't be alone".) I have detected this in speakers of a number of languages so I feel this is more likely to be a feature of the English language itself than a carry-over from their native language.  I have a faint intuition that this is because , and it certainly doesn't help that , but I can neither make that precise nor even really phrase a concrete question. Can someone shed some light on this?    Edit: just to provide some real-world examples of what I mean, here is one example taken from :     Publish or Perish is designed to empower individual academics to present their case for research impact to its best advantage. We would be concerned if it would be used for academic staff evaluation purposes in a mechanistic way.   This is obviously ungrammatical (to me), but I'm not sure how to characterize the mistake, or what the likely causes are (e.g. whether it follows from analogous constructions in other languages). I know that I have to use some tweaking tool and then a extension for this. But all extensions that are suggested for this(Workspace grid, Workspace matrix), aren't available in the software center. Should I vary input field lengths in a single page checkout form? How to give an image or video a TV screen effect? I have a question about inheritance in Java.  I have two classes A and B , and class B, inherits from A:  public class A {      public A() {          System.out.println("Hi!");      } }   public class B extends A {      public B() {          System.out.println("Bye!");      }       public static void main(String[] args) {          B b = new B();      } }   When I run program B, the output is:  Hi! Bye!      Question : why the constructor of class A is invoked, when I create and object of class B ?    I know that B inherits everything from A - all instance or class variables, and all methods, and in this sense an object of B has all characteristics of A plus some other characteristics defined in B. However, I didn't know and didn't imagine that when I create an object of type B, the constructor of A is also invoked. So, writing this:  B b = new B();   creates Two objects - one of type B, and one of type A.  This is getting interesting,   can somebody explain why exactly this happens?