how to create a light streak(trail) in Blender 2.8?
How can I create Light Streaks in Cycles?
mysql database no space available Is it possible to make my laptop's screen act as a second monitor for my desktop computer? The age of the universe Many times I have read statements like, "the age of the universe is 14 billion years" . For example this wikipedia page .   Now, my question is, which observers' are these time intervals? According to whom 14 billion years? Does a car use friction to move? Beamer: change header background color I have decided to switch from Powerpoint to Beamer, and for my first presentation I'd like to use the , and the same colors as in this goggle slide template:  .  I tried to do some research about it, the closest answers I found are the question  and the . I tried this code:  \documentclass{beamer} \usepackage[frenchb]{babel} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc}  \usetheme{metropolis}  \definecolor{bluegreen}{rgb}{3, 166, 155} \definecolor{pitchblack}{rgb}{0, 0, 0} \definecolor{lightbeige}{rgb}{255, 251, 241} \definecolor{mediumgray}{rgb}{183, 183, 183}  \setbeamercolor{background canvas}{bg=pitchblack} \setbeamercolor{normal text}{fg=lightbeige} \setbeamercolor{headline}{bg=bluegreen, fg=mediumgray}  \begin{document} \begin{frame}     \frametitle{The title}     Lorem ipsum... \end{frame} \end{document}   I does everything I want, except that the title bar's background color is lightbeige:    What did I do wrong? Or what argument should I pass to \setbeamercolor to get it right? Thanks in advance :-). I'm missing all the usual processing tools in the Vector menu in QGIS 2.16 (eg vector overlay, analysis, etc). They do appear in the processing toolbox but there's no sign of them in the Vector menu. Has anyone come across this issue? Registering a domain name with a trademark in it Deleted object would be re-saved by cascade (remove deleted object from associations) Is there any "superlogarithm" or something to solve $x^x$? Is there any "superlogarithm" or something to solve an equation like this:  $$x^x = 10?$$ In classical statistics, there is a definition that a statistic $T$ of a set of data $y_1, \ldots, y_n$ is defined to be complete for a parameter $\theta$ it is impossible to form an unbiased estimator of $0$ from it nontrivially. That is, the only way to have $E h(T (y )) = 0$ for all $\theta$ is to have $h$ be $0$ almost surely.   Is there a intuition behind this? Is seems like a rather mechanical way of defining this, I am aware this has been asked before, but was wondering if there was a very easy to understand intuition that would make introductory students have an easier time digesting the material. Flagged emails keep returning and won't synchronize between Apple Mail and Gmail I've had this problem before and can't recall how I managed to fix it last time. I use Apple Mail to access my Gmail and normally flagged emails show up correctly. Starred emails in Gmail equate to flagged emails in Apple Mail and I can unflag an email in either Gmail or Apple Mail and it works.  But now I've got four emails that I can't unflag. They're not flagged in Gmail at all (although they used to be). When I see them in the Flagged folder in Apple Mail, they don't even have flag icons next to them but they're still counted in the number showing next to "Flagged". If I manually re-flag them and then unflag them, they disappear from the Flagged box. But then if I click into Inbox and then back into Flagged they show up again.  Any ideas about how to make these guys disappear for good?! Is there a *simple* example showing that uncorrelated random variables need not be independent? Can we move "Start a bounty" to a more intuitive location? Combined flair not updating with badges I've got 28 bronze badges on Stack Overflow, 10 on Astronomy and 15 on Software Recommendations, making it a total of 53. Yet, my combined flair doesn't show that. It just shows the combined badges from my SO and Astronomy SE sites. The reputation has no problem. I can see the correct combined rep. Why is it happening? Is it because Software Recommendations is in private beta?  Here are the flairs (Combined and that from Software Recommendations):     The rep on my combined flair is the sum total of my rep from all three sites. But the badges aren't. UnboundLocalError on local variable when reassigned after first use The following code works as expected in both Python 2.5 and 3.0:  a, b, c = (1, 2, 3)  print(a, b, c)  def test():     print(a)     print(b)     print(c)    # (A)     #c+=1       # (B) test()   However, when I uncomment line (B), I get an UnboundLocalError: 'c' not assigned at line (A). The values of a and b are printed correctly. This has me completely baffled for two reasons:   Why is there a runtime error thrown at line (A) because of a later statement on line (B)? Why are variables a and b printed as expected, while c raises an error?   The only explanation I can come up with is that a local variable c is created by the assignment c+=1, which takes precedent over the "global" variable c even before the local variable is created. Of course, it doesn't make sense for a variable to "steal" scope before it exists.  Could someone please explain this behavior? "need to do" vs "need do" Consider:  I need to do this. I need do this.  My English grammar knowledge tells me that &quot;need&quot; doesn't have the same status as the modal verbs &quot;may&quot;, &quot;can&quot;, &quot;should&quot; and what not. Hence the second usage where two verbs appear consecutively is incorrect. But yesterday, my native English speaking friends (Americans) told me that &quot;I need compute this.&quot; is a perfectly grammatical sentence, and one is simply omitting the &quot;to&quot;. How can this be? Is it a colloquial usage but grammatically incorrect, or is it grammatically correct? If it is grammatically correct, is it because &quot;need&quot; is a semi-modal verb? EDIT: in particular, is it okay to use &quot;need compute&quot; in a scientific paper? EDIT2: the exact phrase that raised the question was &quot;The advantage of this representation is that we need only compute sums and products&quot; I keep hearing a lot about functors in C++. Can someone give me an overview as to what they are and in what cases they would be useful? Prove that all cyclic groups of the same order are isomorphic I want to prove that 2 cyclic groups of the same order are always isomorph. So, let $G,H$ be cyclic groups with $|G| = |H|$. Then: I suspect the isomorphism would be the one that maps a generator g to a generator h. Thus, consider this function:  $f: G \rightarrow H$ defined by $f(g^k) = h^k$. I already showed that this mapping is surjective and a homomorphism, but I get stuck at the injectivity part. Can someone give a hint (my attempts: I tried to deduce whether the kernel is $e_G$ and I also used the definition of injectivity but I got stuck in both approaches)? Gamma Distribution out of sum of exponential random variables Checking via ArcPy if ArcMap is in edit session?