Why does the electric dipole moment of the electron tell us about its sphericity?
What is the mass density distribution of an electron?
put (a) and (b) to one in subfigures Why is my Wi-Fi process using 3GB of memory? How would you make a comma-separated string from a list of strings? Recommendations on a free library to be used for zipping files I need to zip and password-protect a file. Is there a good (free) library for this?  This needs to be opened by a third party, so the password protection needs to work with standard tools. Was Louis stalked days in advance too? Since Naruto failed the Genin exam so many times, doesn't that mean he's older than Sasuke and Sakura? Completeness and Incompleteness Through browsing questions asked in the past about Godel's completeness and imcompleteness theorems, I've come to see that the sense of completeness in both of the theorems are different. However, I can't see how they are different!   Does this distinction boil down to that of truth and proof? Is it the case that the completeness theorem talks about the relationship between truth and proof, while the incompleteness theorems only relate to provability?  Could someone please elaborate on the sense in which both notions of completeness are different? Using property() on classmethods I have a class with two class methods (using the classmethod() function) for getting and setting what is essentially a static variable.  I tried to use the property() function with these, but it results in an error.  I was able to reproduce the error with the following in the interpreter: class Foo(object):     _var = 5     @classmethod     def getvar(cls):         return cls._var     @classmethod     def setvar(cls, value):         cls._var = value     var = property(getvar, setvar)  I can demonstrate the class methods, but they don't work as properties: &gt;&gt;&gt; f = Foo() &gt;&gt;&gt; f.getvar() 5 &gt;&gt;&gt; f.setvar(4) &gt;&gt;&gt; f.getvar() 4 &gt;&gt;&gt; f.var Traceback (most recent call last):   File &quot;&lt;stdin&gt;&quot;, line 1, in ? TypeError: 'classmethod' object is not callable &gt;&gt;&gt; f.var=5 Traceback (most recent call last):   File &quot;&lt;stdin&gt;&quot;, line 1, in ? TypeError: 'classmethod' object is not callable  Is it possible to use the property() function with @classmethod decorated functions? Privacy/Security concers for setting up business email using Gmail app on Nexus devices I need to set up my business email*(non gmail email)* on the mobile devices (Nexus 5 and Nexus7). The business has its own private mail server. The way I can do it is by using Gmail app on these devices. The question I have is does Gmail app on the mobile devices store the IMAP emails(non gmail emails) on the gmail servers? Or Gmail app is just a client and does not bother storing the IMAP emails(non gmail emails) on its servers that are not gmail emails? Thanks for the insight... Suppose $x&gt;0$ and we have function $f(x)=\frac{\sin x}{x}$ how can we show $$\forall n \in \mathbb{N} :|f^{(n)}(x)|\leq \frac{1}{n+1}$$ I need a hint to show this property .Thanks in advance . I tried for $n=1 ,2$  by finding maximum of $|f'| ,|f''|$ but I get stuck to show for $n$ Can you reuse marinade used with raw chicken? Implicit newline at the end of each paragraph? Chance of selecting the last k pages in correct order from a set of n pages The system L0 is defined as follows:  Axioms: A1 (α → (β → α))  A2 2. (α → (β → γ) → ((α → β) → (α → γ))  A3 ((¬β → ¬α) → ((¬β → α) → β))  In one of my problem sheets, I am told that I am allowed to use the following theorem: if   ⊢ (α → α)    ⊢ (α → α) → (α → α)  My attempt to solve/prove the second one  ⊢ (α → α) → (α → α) choose 2 axioms which match.  α →α   β→α  γ→α  (α → (α → α) → ((α → α) → (α → α))  I'm struggling to see an obvious way of proving the theorem.  Is it provable? And if so, can you point me in the right direction?  Thanks a lot! I'm having a problem rendering the environment map. I downloaded a sample project that has the same settings as my project but it renders without a problem. I tried using both a .hdr and .png image. Attached are screenshots with node settings. First is the incorrect render and 2nd image is the project the renders correctly. How do I go about fixing this? When selecting components, is there a way to control the "selection distance/area"? I don't want to select a component, even if I click ~20 pixels away from it.    Thanks in advance! How do I make Subversion (SVN) send email on checkins? I've always found checkin (commit) mails to be very useful for keeping track of what work other people are doing in the codebase / repository. How do I set up SVN to email a distribution list on each commit?  I'm running clients on Windows and the Apache Subversion server on Linux. The answers below for various platforms will likely be useful to other people though. Lets say an object is tied to a string and it is being swung in a circle:    In this case, the tension of the string acts as a centrifugal force that keeps the object moving in a circle. However, if centrifugal force is the only force acting on the object, why doesn't it collapse into the center? I am pretty sure this has to do with the object's inertia (or the centrifugal pseudo-force), where it moves slightly forward in a tangent before falling, restoring the orbit.  Also, what keeps the string taut during the swinging? There has to be some force countering the centripetal force that keeps the string tight. I think this might again have to do with the intertia/centrifugal pseudo-force but can a pseudo-force balance a real force? Also, if centripetal were to be balanced by the pseudo-force, wouldn't the object not move at all (since the net force would be 0)? Search for ,        ,                        and you will see that "results found containing __" is just a little too close to the header. It's not like there isn't  to have it be a little lower, closer to "Search":          The UI has been updated since I took the above screenshots, and the text you search for is  (which fixes another design issue but not the one in this question): How to find location using MapKit in Xcode?