How to draw 3 vectors using Graphics3D?
Draw a vector with mathematica
Is there any "official" guidance to upgrading from Lubuntu 18.04 LTS (LXDE) to Lubuntu 18.10 (LXQt) Hubble's constant $a(t)$ appears to be changing over time. The fine stucture constant $\alpha$, like many others in QFT, is a running constant that varies, proportional to energy being used to measure it. Therefore, it could be agued that all running constants have 'evolved' over time as the Universe has expanded and cooled. Both the local and global curvature of the Universe changes over time implying that so too does the numerical value of $\pi$. All these things are however constants (well, let's say parameters since they are not really 'constant'.)   In  with astronomer Sir Fred Hoyle, Feynman said "what today, do we not consider to be part of physics, that may ultimately become part of physics?" He then goes on to say "..it's interesting that in many other sciences there's a historical question, like in geology - the question how did the Earth evolve into the present condition? In biology - how did the various species evolve to get to be the way they are? But the one field that hasn't admitted any evolutionary question - is physics."  So have the laws of physics remained form-invariant over the liftetime of the Universe? Does the recent understanding of the aforementioned not-so-constant constants somehow filter into the actual form of the equations being used? Has advances in astronomical observations, enabling us to peer back in time as far back as the CMB, given us any evidence to suggest that the laws of nature have evolved? If Feynman thinks that "It might turn out that they're not the same all the time and that there is a historical, evolutionary question." then this is surely a question worth asking.  NB/ To be clear: this is a question concerning purely physics, whether the equations therein change as the Universe ages, and whether there is any observational evidence for this. It is not intended as an oportunity for a philosophical discussion. Why say "of x's" instead of "of x"? I have often heard people say "x of his" or "x of mine". But since his and mine point out ownership, isn't using "of" here doubles that ownership? Wouldn't it be more appropriate to say "x of him" or "x of them" etc.?  Example:     I was a good friend of your dad's. He told me all about you` HDMI over cat extender video Why is the range of inverse trigonometric functions defined in this way? My question is really simple, why is the range of the $\sin^{-1}(x)$, $\cos^{-1}(x)$ and $\tan^{-1}(x)$ defined as $[-\pi/2,\pi/2]$, $[0,\pi]$ and $[-\pi/2,\pi/2]$ respectively? Is there some particular reason? We could choose another range for each inverse trigonometric function. For example, we can pick $[0,\pi]$ to be the range of $\sin^{-1}x$.  EDIT  I've understood why the range of the sine and cosine has to be $[-\pi/2,\pi/2]$ and $[0,\pi]$ respectively. I'm still wondering why can't we define the range of the tangent as $[0,\pi]$ Modify a class definition's annotation string parameter at runtime How much money do you need to have on hand when entering USA? My friend, a Chilean citizen, is entering the US via waiver program to spend 3 weeks in USA in a couple of weeks. She already got her ESTA approval, the plane ticket, all hotels are already booked (but paid by me, not her).  How much money would she need to bring with her when entering US? Do they still check this? She would of course have credit cards with her. How to hyperlink only the year part when using natbib and hyperref I am using the natbib and hyperref packages:  \usepackage{natbib}  \usepackage[pagebackref=true, plainpages=false, bookmarks, bookmarksnumbered, colorlinks, linktocpage=true, linkcolor=blue, citecolor=blue, filecolor=black, urlcolor=blue]{hyperref}   With my current settings (above) both the name and the year are hyperlinked.  My question is, whether there is a way to hyperlink (or color) only the year-not the author(s).   I have the impression reading this post  that biblatex does it by default. However changing to biblatex is not an option for me at this point.  Any helpful comments will be greatly appreciated. I have a ton of MP3s, but their ID tags are not filled in.  Going in manually to populate them is simply too much work.    I was wondering if there is a way to populate them automatically.  Perhaps by feeding the MP3s to Shazam or Midori or something like.  I am not above writing some code to make it happen, if someone can suggest a way. minitoc package adds extra page when used with float and lastpage packages The minitoc package adds extra page when used with float and lastpage packages. I figured out that this problem can be resolved by loading minitoc package before float and lastpage packages. In LyX the float package is loaded automatically and could not figure out how to force LyX  use minitoc package before loading float and lastpage packages. Thanks in advance for your help.  \documentclass[a4paper,12pt]{book} \usepackage[english]{babel} \usepackage{blindtext} \usepackage{lastpage} \usepackage{fancyhdr} \usepackage{float} \usepackage{minitoc} \begin{document} \dominitoc \tableofcontents \mainmatter \chapter{First Chapter} \minitoc \section{Introduction} \blindtext[1] \section{Material \&amp; Method} \blindmathpaper \chapter{Second Chapter} \minitoc \section{Introduction} \blindtext[1] \section{Material \&amp; Method} \blindmathpaper \end{document}   Edited  It is also working in LyX 2.1.1 if I remove \includepdf[pages={1},scale=1]{Back.pdf} at the end of the document. However if I include \includepdf[pages={1},scale=1]{Back.pdf} at the end of the document it adds extra page. Any thoughts.   Updated  I've narrow downed the problem. My following MWE in .Rnw format adds extra page at the end of document when using minitoc package. Thanks again for your help.  \documentclass[a4paper,12pt]{book} \usepackage{minitoc} \usepackage[english]{babel} \usepackage{blindtext} \usepackage{lastpage} \usepackage{fancyhdr} \usepackage{float} \usepackage{pdfpages} \begin{document} \dominitoc \tableofcontents \mainmatter  \chapter{First Chapter} \minitoc \section{Introduction} &lt;&lt; Test &gt;&gt;= 1:50 @  \blindtext[1] \section{Material \&amp; Method} \blindmathpaper \includepdf[pages={1},scale=1]{Back.pdf} \end{document} Finding the limit of $(1-\cos x)/x^2$ I use ubuntu to deal with daily job. Now I buy a new laptop, and I want to migrate my whole system(programs, packages, data, settings, etc) to the new machine.  I know I can copy my home folder to new machine and I will get (almost) all data and settings. But is there a safe way to copy the whole system? Or it's a bad idea? What is the difference between linear regression on y with x and x with y? Seeking open raw LiDAR or laser scanner data? Execute vs Read bit. How do directory permissions in Linux work? In my CMS, I noticed that directories need the executable bit (+x) set for the user to open them. Why is the execute permission required to read a directory, and how do directory permissions in Linux work? Is there a new auto-login feature? Gnome keyring daemon not starting up properly I know there are some command-line applications like pdflatex that can help me to compile a LaTex document from C#.Net (using the System.Diagnostics.Process class) .   I wanna know that what's the best command-line tool for compiling a TeX document ? How do you plot time on the X axis in excel? I need to plot the decay of my phone's battery against time over night. My starting time is 23:17:47 and my ending one is 07:05:49. I don't have any issue in changing the time format in the current one, selecting an XY chart and plotting time on the X axis.   The problem arises because Excel doesn't start the X axis at 23:17:47, but instead at 00:00:00, so my first value is drawn from the end of the graph and the goes back at the beginning when time values are over 00:00:00.   In other words, how do I set up the min time value to 23:17:47 and the max to 07:05:49 in excel? How can one prove the Bohr-Sommerfeld quantization condition $$ \oint p~dq ~=~2\pi n \hbar $$ from the WKB ansatz solution $$\Psi(x)~=~e^{iS(x)/ \hbar}$$ for the Schroedinger equation? With $S$ the action of the particle defined by Hamilton-Jacobi equation $$ \frac{\partial S}{\partial t}+ \frac{(\nabla S)^{2} }{2m}+V(x)~=~0 .$$