Backing up data
What's a good back-up strategy for 1 desktop PC?
What are the complexity guarantees of the standard containers? There's another question on physics.SE whose , if I have understood it correctly, explains that the farther the points are in space the faster they are moving away from each other.     Actually, the apparent speed with which two of the points on the   circle in a distance $D$ of each other would move relative to each   other will be $v = H_0 D$ where $H_0$ is the speed the balloon itself   is expanding.   This means that even the ruler sitting on my desk is expanding, just that the expansion is very very slow owing to the ruler's small size relative to the cosmic scales. However, if everything is scaling then everything should apparently be of the same size to an observer in such an expanding space. The  quote from the show "The Big Bang Theory" comes to mind.   To be able to counter that, there're some phenomena that we can observe which are scale invariant. Red-shift would be one such phenomenon. But is red-shift the only way we can tell that the space is expanding? Is there a logical flaw in my thinking? I know that red-shift is a result of the Doppler effect - there's bound to be a decrease in the frequency of a signal, as perceived by an observer, emitted by a source which is moving away relative to the observer. I'm not very knowledgeable about physics generally, but know that nothing can escape a black hole's gravitational pull, not even light (making them nearly invisible?).   My question is: What has been obtained from direct observation of a black hole to prove their existence? Please note that I'm not questioning the existence of black holes, but am just curious as to how we have come to realize it. How to install Skype 4.3? Note: The legacy Skype for Linux application (v4.*) is now discontinued and was removed from Canonical’s partner repositories, so this question and its answers are obsolete. Please refer to  of our .  Skype 4.3 is just released with considerable improvements. As a regular Skype user I want to use the latest Skype on my Ubuntu 14.04, but there is no updates from Update Manager. Even in Skype website only Skype 4.3 is available only for Ubuntu 12.04. Is there anyway to use this latest Skype on Ubuntu 14.04 or how much we have to wait for the update? How do I prove that $S^n$ is homeomorphic to $S^m \Rightarrow m=n$? This is what I have so far:  Assume $S^n$ is homeomorphic to $S^m$. Also, assume $m≠n$. So, let $m&gt;n$.  From here I am not sure what is implied. Of course in this problem $S^k$ is defined as:  $S^k=\lbrace (x_0,x_1,⋯,x_{k+1}):x_0^2+x_1^2+⋯+x_{k+1}^2=1 \rbrace$ with subspace topology. How do I install transition molding between my new hardwood and existing tile floors? I have ripped out some old carpet and am preparing to install a new solid hardwood floor myself.  In several places, the floor transitions to an existing tile floor.  The hardwood floor guys told me the best transition between the two is a T molding.  You simply leave a gap between the two floors, and then place down the T molding between the two floors, so it sits on both surfaces.  Sounds simple enough.  However, the height difference of the two floors is considerable, and the T molding does not sit flush.  What are my options?  Here is a diagram showing the dimensions.      NOTE:  Using the T molding is not a requirement, I could go some other route if there is a better option. WI-FI Nic showing 3 different transport id {Device id} There was a problem with my network controller so i opened up cmd and started to check for interfaces. I noticed a strange thing that my Wifi network controller had 3 different Device ID (Transport id's) When i tried to disable the wifi card the different id's went away. On my other computer i tested the same thing and it only shows 1 id? Device\NPF_{4A45A363-6346-48DA-8D28-13DD9C9C1E6A} Device\NPF_{E6994972-C66C-4ABF-BE27-17BAC7C1C971} Device\NPF_{B6394772-H66C-4ABF-HRE27-17JLC0H9C971} I am using snort to check for available interfaces. Can anybody explain why i am seeing this? WLC model: intel dual band wireless-ac 8265 running default settings on the adapter however i have hyper-v open Modern Linux commands that parallel uuencode/uudecode functionality I need to get binary files into text format.  Years ago, I used uuencode/uudecode, and it was easy:  uuencode file.xls &gt; file.txt # Delete file.xls # Do whatever with file.txt # Now I need file.xls back uudecode file.txt &gt; file.xls   But uuencode/uudecode is not on my system, and as I look around, the yum/rpm process is ugly--this gives me the clue that maybe no one uses it any more and instead there is something more modern to do this.  I looked at xxd and hexdump but couldn't get them to do it.  Could just be dumb user issues.  What can I use on Linux to do this?  Would like it to be something that tends to be in the native install so I don't need to yum/rpm it if possible.  Just for your own understanding, what I'm specifically trying to do now is source control an *.xls file but the corporate tool doesn't allow *.xls in.  I respect that constraint normally, but in my context, an *.xls is a configuration table for my code so It is logically like source code, but the corporate SVN trigger is physical--if it's *.xls, it gets rejected, so I'll encode it and source control the *.txt file.  Thanks! Combining multirow and multicolumn When combining multirow and multicolumn in the same cell of a table I am getting extra vertical lines:  \documentclass[plain]{article} \usepackage{multirow} \pagestyle{empty}  \begin{document}  \begin{tabular}{|l|l|l|l|}\hline   \multirow{10}{*}{numeric literals} &amp; \multirow{5}{*}{integers} &amp; in decimal &amp; \verb|8743| \\ \cline{3-4}   &amp; &amp; \multirow{2}{*}{in octal} &amp; \verb|0o7464| \\ \cline{4-4}   &amp; &amp; &amp; \verb|0O103| \\ \cline{3-4}   &amp; &amp; \multirow{2}{*}{in hexadecimal} &amp; \verb|0x5A0FF| \\ \cline{4-4}   &amp; &amp; &amp; \verb|0xE0F2| \\ \cline{2-4}   &amp; \multirow{5}{*}{fractionals} &amp; \multirow{5}{*}{in decimal} &amp; \verb|140.58| \\ \cline{4-4}   &amp; &amp; &amp; \verb|8.04e7| \\ \cline{4-4}   &amp; &amp; &amp; \verb|0.347E+12| \\ \cline{4-4}   &amp; &amp; &amp; \verb|5.47E-12| \\ \cline{4-4}   &amp; &amp; &amp; \verb|47e22| \\ \cline{1-4}   \multicolumn{3}{|l|}{\multirow{3}{*}{char literals}} &amp; \verb|'H'| \\ \cline{4-4}   &amp; &amp; &amp; \verb|'\n'| \\ \cline{4-4}   &amp; &amp; &amp; \verb|'\x65'| \\ \cline{1-4}   \multicolumn{3}{|l|}{\multirow{2}{*}{string literals}} &amp; \verb|"bom dia"| \\ \cline{4-4}   &amp; &amp; &amp; \verb|"ouro preto\nmg"| \\ \cline{1-4} \end{tabular}  \end{document}     Notice the vertical lines in the char literals and string literals cells (which should span three columns). How can they be avoided? In summer, should I close curtains during the day? apt-get autoremove wants to remove linux headers How do i show that $w=z^2$ maps $|z-1|\leq 1$ onto the cardioid $R=2(1+\cos \theta)$? Questions like  dealing with Ancalagon in particular, and Middle-earth's dragons in general, clearly show that Ancalagon was ridiculously, absurdly, unimaginably enormous.      The non-canonical image above shows one person's impression of how the different dragons of Middle-earth stacked up, with Smaug looking absolutely tiny at the far left, and Ancalagon on the right, too big to even fit in the picture.    Below, a presumably canonical picture, painted by Tolkien himself, shows Smaug in relation to Bilbo.  The rough measurements I took from this image suggest that Smaug is about 11 times longer than Bilbo is tall.  Depending on how tall Bilbo is - almost certainly somewhere between 3'6" and 4' tall - Smaug is approximately 38-44 feet long.      If the first picture is even vaguely accurate, Ancalagon would appear to be a minimum of something like 720 feet long from the tip of his nose to the end of his tail:  the visible portions of his head and body are at least 6 times longer than Smaug is from end to end, and we have to assume that the portion of his body that is out of frame is at least 3 times longer still, perhaps even 4 times or more (so the upper range of his length might exceed 1,000 feet).  Does Tolkien give us any way to estimate how big Ancalagon was?  It isn't his normal practice to describe things in great detail, I realize, but he often gives a few hints that allow for some rough approximation to be made.  Does anything he says suggest that the first image is anything like what he had in mind?  Note:  I haven't read anything about Ancalagon from Tolkien's own pen, except a few quotes on this site;  the most important bit of information I've gleaned is that he smashed 3 volcanoes to pieces when he died (or something like that).  How accurate is this, and what else did Tolkien say?    This question is not a duplicate of "", because none of the answers to that question address Ancalagon's size in any detail - except my own, which is based on what little information I was able to glean from the two pictures I included in this question.  All the other answers address how Ancalagon was killed, not how big he was.  I have no interest in how he died, only how big he was, or rather, what hints we can find that might give some indication of how big he was.  I wouldn't ask this question, linking that question in my own, if it contained the information I am interested in.    Note 2:  Regarding the relative sizes and impressiveness of Smaug and Ancalagon:  Imagine a meeting between Smaug and Ancalagon in Dragon Heaven: Smaug: "How'd you die?" Ancalagon: "A flying boat full of fire made by the Angels and driven by a Magic Elf smashed into me, so I fell onto a mountain and broke it, and I died. The Magic Elf lives in outer space now, and the boat turned into a star. How'd you die?" Smaug: "Um... Some dude shot me with an arrow." Compute the limit $\lim_{n \to \infty} \frac{n!}{n^n}$ What's the opposite word for "sin"? I would like to know if there is an opposite word for sin in English.  I mean, how could I say the opposite of     I committed a sin   other than using a negation? How do I tell Maven to use the latest version of a dependency? In Maven, dependencies are usually set up like this:  &lt;dependency&gt;   &lt;groupId&gt;wonderful-inc&lt;/groupId&gt;   &lt;artifactId&gt;dream-library&lt;/artifactId&gt;   &lt;version&gt;1.2.3&lt;/version&gt; &lt;/dependency&gt;   Now, if you are working with libraries that have frequent releases, constantly updating the &lt;version&gt; tag can be somewhat annoying. Is there any way to tell Maven to always use the latest available version (from the repository)? Origin of the meaning of joe How to find $ f(x)$ if $f(1-f(x))=x$ for all $x$ $\in \mathbb{R}$ How can I determine $ f(x)$ if $f(1-f(x))=x$ for all real $x$?  I have already recognized one problem caused from this: it  follows that $ f(f(x))=1-x $, which is discontinuous. So how can I construct a function $f(x)$?  Best regards and thanks, John I learned thermodynamics and the basics of statistical mechanics but I'd like to sit through a good advanced book/books. Mainly I just want it to be thorough and to include all the math. And of course, it's always good to give as much intuition about the material.  Some things I'd be happy if it includes (but again, it mostly just needs to be a clear book even if it doesn't contain these) are:   As much justifications for the postulates if possible, I'm very interested in reading more about how Liouville's theorem connects to the postulates. Have examples of calculating partition functions, hopefully not just the partition function for the ideal gas. Metropolis is not working I tried to use the metropolis beamer theme, but I got the following error  ! Package beamerfontthememetropolis Error: Patching section title failed. See the beamerfontthememetropolis package documentation for explanation. Type H &lt;return&gt; for immediate help.... \patchcmd