Mortarboard Day Period At the risk of sounding like a complainer:  I just got (over) 200 rep.  It's 5:23PM here in Colorado, yet the rep I received just an hour ago is listed in "yesterday", and the most recent 30 in "today".  Am I missing a time zone setting, or is this something I have to remember when considering pursuing a badge?
What is an SE "day"? When does each day start? When does a day start on the Stack Exchange network? Some badges (Enthusiast, , ) and voting limits are bound by and relate heavily to the concept of a day. Do days correspond to calendar days? What time zone is used?  Related
Assigning point IDs to respective start and end attributes of polyline? Is $R^2$ useful or dangerous? "error: XDG_RUNTIME_DIR not set in the environment." when attempting to run nautilus as root I am attempting to run nautilus as root but when I run "sudo nautilus" from the terminal, I get the following error:     error: XDG_RUNTIME_DIR not set in the environment.      (nautilus:9341): Gtk-WARNING **: cannot open display:   The issue does not occur when I attempt to run nautilus as non-root. I am using ubuntu 14.04. Does anyone know how I can fix this? change thickness median line geom_boxplot() Properly discontinuous actions and discrete groups in complete Riemannian manifolds. I was reading the article "The Geometries of 3-manifolds" by Peter Scott and in the end of page 406 he states the following:     If $G$ acts properly discontinuously on a space $X$, then $G$ is a   discrete subset of the space of all continuous functions $X \to X$   with the compact-open topology. The converse is false, in general, but   is true if $X$ is a complete Riemannian manifold and $G$ is a group of   isometries of $X$.   How do I prove the last statement?     If $X$ is a complete Riemannian manifold and   $G$ is a group of isometries of $X$ acting properly discontinuously on $X$, then $G$ is discrete.    Observation: We say a group $G$ of homeomorphisms of $X$ acts properly discontinuously on $X$ if for every compact $K \subset X$ the set $$\{g \in G: gK \cap K \neq \emptyset\}$$ is finite. X and Y are not correlated, but X is significant predictor of Y in multiple regression. What does it mean? X and Y are not correlated (-.01); however, when I place X in a multiple regression predicting Y, alongside three (A, B, C) other (related) variables, X and two other variables (A, B) are significant predictors of Y. Note that the two other (A, B) variables are significantly correlated with Y outside of the regression.   How should I interpret these findings? X predicts unique variance in Y, but since these are not correlated (Pearson), it is somehow difficult to interpret.  I know of opposite cases (i.e., two variables are correlated but regression is not significant) and those are relatively simpler to understand from a theoretical and statistical perspective. Note that some of the predictors are quite correlated (e.g., .70) but not to the extent that I would expect substantial multicollinearity. Maybe I am mistaken, though.    NOTE: I asked this question previously and it was closed. The rational was that this question is redundant with the question "". Perhaps I do not understand the other question, but I believe these are entirely separate questions, both mathematically and theoretically. My question is entirely independent from if "a regression is significant". Furthermore, several predictors are significant, while the other question entails variables not being significant, so I don't see the overlap. If these questions are redundant for reasons I do not understand, please insert a comment prior to closing this question. Also, I was hoping to message the moderator who closed the other question to avoid identical questions, but I couldn't find an option to do so. How can one prove the statement $$\lim_{x\to 0}\frac{\sin x}x=1$$ without using the Taylor series of $\sin$, $\cos$ and $\tan$? Best would be a geometrical solution.  This is homework. In my math class, we are about to prove that $\sin$ is continuous. We found out, that proving the above statement is enough for proving the continuity of $\sin$, but I can't find out how. Any help is appreciated. Vertical Text in Wpf TextBlock Is it possible to display the text in a TextBlock vertically so that all letters are stacked upon each other (not rotated with LayoutTransform)? Track next Socratic badge progress Just got the  on StackOverflow and, since it can be awarded multiple times, wanted to start tracking progress to the next one, but, the badge is not shown in Available badges to track anymore:    Is it possible to track already awarded badges that can be awarded multiple times? How to remove duplicate values from an array in PHP How can I remove duplicate values from an array in PHP? Creating centerline from lines using QGIS How do I create a centerline (vector data) from two parallel polylines (vector data) in QGIS? For example, if the distances between two parallel lines are 14m, then I want to create a centerline at 7m from both lines. When is double-quoting necessary? The old advice used to be to double-quote any expression involving a $VARIABLE, at least if one wanted it to be interpreted by the shell as one single item, otherwise, any spaces in the content of $VARIABLE would throw off the shell.  I understand, however, that in more recent versions of shells, double-quoting is no longer always needed (at least for the purpose described above).  For instance, in bash:  % FOO='bar baz' % [ $FOO = 'bar baz' ] &amp;&amp; echo OK bash: [: too many arguments % [[ $FOO = 'bar baz' ]] &amp;&amp; echo OK OK % touch 'bar baz' % ls $FOO ls: cannot access bar: No such file or directory ls: cannot access baz: No such file or directory   In zsh, on the other hand, the same three commands succeed.  Therefore, based on this experiment, it seems that, in bash, one can omit the double quotes inside [[ ... ]], but not inside [ ... ] nor in command-line arguments, whereas, in zsh, the double quotes may be omitted in all these cases.  But inferring general rules from anecdotal examples like the above is a chancy proposition.  It would be nice to see a summary of when double-quoting is necessary.  I'm primarily interested in zsh, bash, and /bin/sh. If $f:[a,b]\to \mathbb{R}$ is continuous and nonnegative and $\int_a^b{f}=0$, then $f(x)=0$ for all $x\in [a,b]$ $SU(3)$ irreducible representations with tensor method I am dealing with the tensor product representation of $SU(3)$ and I have some problems in understanding some decomposition.  1) Let's find the irreducible representation of $3\otimes\bar{3}$  we have that this representation trasforms like   $${T^\prime}^i_j=U^i_k {U^{\dagger}}^l_j T^k_l $$  hence I observe that  $$Tr(T)=\delta^j_iT^i_j$$ is an invariant and so  $$T^i_j=\left(T^i_j-\frac{1}{3}\delta^j_iT^i_j\right)+\frac{1}{3}\delta^j_iT^i_j$$  allows me to write $$3\otimes\bar{3}=8\oplus1$$ Here comes my questions: I have heard that this $8$ representation is an "$8_{MA}$" where MA is for "mixed-antisymmetric". The meaning of "mixed-antisymmetric" shold be: "the tensor $\left(T^i_j-\frac{1}{3}\delta^j_iT^i_j\right)$ should be antisymmetric for an exchange of 2 particular indexes but not for a general exchange of 3 indexes". What does this mean? I see only 2 index in that tensor.  2) Consider this representation: $$3\otimes3\otimes3=3\otimes(6\oplus\bar{3})=3\otimes6_S\oplus3\otimes\bar{3}=3\otimes 6_S\oplus8_{MA}\oplus1$$  and now on my notes I have $$3\otimes6_S=10_S\oplus8_{MS}$$  Where "MS" is for "mixed symmetric": symmetric for an exchange of 2 particular indexes but not for a general exchange of 3 indexes.  I could not demonstrate this last decomposition using tensor method. I started noticeing that: $$3\otimes6_S=q^iS^{k,l}$$ where $S^{k,l}$ is a symmetric tensor But then I am not able to proceed in demonstrating the above decomposition (note: I would like to demonstrate this decomposition using only tensor properties, not Young tableaux). I tried to look on Georgi, Hamermesh, Zee and somewhere online but I have not found any good reference which explains well this representatin decomposition...  EDIT: the demonstration should not include the use of Young diagrams...my professor started the demonstration by writing $\epsilon_{\rho,i,k}q^i S^{k,l}=T'^l_\rho=8_{MS}$ and then stopped the demonstration. How do I remove extra Skype icon or ghost icons for removed apps from GNOME shell? Lock your computer after 5 minutes of inactivity How to make a modification take affect without restarting nginx? Apache has a graceful option which can scan for modification in http.conf without restarting Apache. What about nginx? Gravitational wave solutions to the Einstein field equations It is well known that general relativity predicts gravitational waves, but I would like to know how. What solution(s) to the Einstein field equations yield something which can be interpreted as a wave(-like) phenomenon? linear transformation $T$ such that $TS = ST$ Let $V$ be a finite-dimensional vector space over $F$. Let $T:V \rightarrow V$ be a linear transformation such that $ST=TS$ for all linear transformations $S:V \rightarrow V$. Show that $T = cI_v$ for some $c \in F$. Why is Facebook missing from the list of ways to share a page in Safari?  That option used to exist before the latest update.  When I'm directed to the extensions box Facebook is not there.