Get ping time in python
Ping a site in Python?
Can a free particle absorb/emit photons? Are Ubuntu packages security audited? I am running an HP pavilion dv6000 dual boot win7 and Ubuntu 12.04. (well, up until today).  After a reboot, the boot process drops to the BusyBox shell and I end up at the prompt:  BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs)   I've been researching others who have had this same problem, but haven't been able to find any of those solutions to work for me.  I tried the method described , and after the final command   mount -t ntfs-3g /dev/sda1 /root -o force   it does nothing and gives me another (initramfs) prompt.  I can boot to a live CD (USB) and get to a terminal, but it doesn't seem to do much good, as I can see the /dev/sda1 in the ls command, but it doesn't recognize it when I try to cd to it.  One more question: using the command fdisk -l how can I tell which mount point (sda1/sda2) is my windows partition and which one is Ubuntu? How can I define a mathematical function as a LaTeX macro? fontenc changes sans serif bold font in KOMA-script Consider the following MWE:  \documentclass{article} %\usepackage[T1]{fontenc}  \begin{document}  \textbf{\textsf{Some text}}  \end{document}   The output of the above code is     and doesn't change if I uncomment the line  %\usepackage[T1]{fontenc}   Consider now the following MWE with scrartcl class instead of article:  \documentclass{scrartcl} %\usepackage[T1]{fontenc}  \begin{document}  \section{A section} \textsf{Some text} \end{document}      Uncommenting the line  %\usepackage[T1]{fontenc}   you get    As you can see, the sans serif font of the title is less  bold than without fontenc, while the normal text is not changed.  Does fontenc, combined with a KOMA-script class, load a different sans serif font, but only for bold face? Is it worth encrypting email addresses in the database? If a company is bought by another company, does my stock rollover to the new company when it is combined with the new parent company? When transiting Moscow (SVO), citizens of which countries need a transit visa? What "allocation unit size" should I use for a drive with a single NTFS partition? I'm formatting a 1TB external hard drive as a single NTFS partition.  This drive is mainly meant for storing media.  Should I choose something other than the default allocation unit size?  The options range from 512 bytes to 64K.  Are there any guidelines that I should use with partitions storing other data?  Should I stop poking around and just leave it at "default"? I have found the command to delete files older than 5 days in a folder  find /path/to/files* -mtime +5 -exec rm {} \;   But how do I also do this for subdirectories in that folder? Creating Workflow -> Error How to prove a matrix is nilpotent? Given an $n\times n$ upper triangular matrix $A$ with zero on main diagonal, show that $A^n = 0$.   I did some matrix operation and noticed that the diagonal moves up, ultimately all entries will be zero. Is there a nicer way to do it? Is FFmpeg missing from the official repositories in 14.04? Line breaking with hyperref href with an underline in itemize I have a simple itemized list like the following MWE:  \documentclass[10pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{graphicx} \usepackage{hyperref} \usepackage{lmodern} \usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry} \usepackage{lipsum} \begin{document} \begin{itemize} \item \href{http://google.com}{[ID1]: \underline{\lipsum[1]}} \end{itemize} \end{document}   This unfortunately doesn't break the block of text as expected, as shown below:    How can I fix this item so it will line break properly? I noticed that there is a definition of the pvalue in my textbook is defined says the following:    I have no idea why it is written with a supremum. I've spent hours pondering this, does anyone have enough of a background to help me with this? Thank you! I am given this problem: Suppose you have a complete graph with $n$ edges. How many vertices does your graph have?  I have this math figured out so far: We know that a complete graph has $m$ vertices, with $m-1$ edges connected to each. This makes the sum of the total number of degrees $m(m-1)$. Then, since this sum is twice the number of edges, the number of edges is $\frac{m(m-1)}{2}$.  But I don't think that is the answer. I think I am missing a piece of the math, but I can't figure out what else I need to do. Can anyone help me with what I'm missing or doing wrong? How can I prove the Carmichael theorem I am trying to prove that these two definitions of Carmichael function are equivalent.  I am using this definition of Carmichael function:     $\lambda(n)$ is the smallest integer  such that $k^{\lambda(n)}\equiv1 \pmod n\,$ $\forall  k$ such that $\gcd(k,n)=1$.   to prove this one:     $\lambda(n) = \begin{cases}\phi(p^a) &amp; (p=2\text{ and }a\le 2)\text{ or }(p\ge 3)\\\dfrac 1 2 \phi{(2^a)}  &amp; a\ge 3\\ \text{lcm}\left((\lambda(p_1^{a_1}),\cdots,\lambda(p_k^{a_k})\right)&amp; \text{for }n=\prod_{i=1}^k p_i^{a_i} \end{cases}$   Since $a^{\lambda(n)}\equiv 1 \pmod n$,  and $a^{\lambda(m)}\equiv1 \pmod m$ with $\gcd(m,n)=1 \implies a^{\text{lcm}({\lambda(n)},\lambda(m)}\equiv1 \pmod {nm} $   Hence $\lambda (mn)=\text{lcm}(\lambda(n), \lambda(n))$ for $m$ and $n$ coprime to each other.  How can I prove the other relations? If I create a custom environment based on the equation environment, I get a spacing issue: the next line of text after my environment closes doesn't start on the left margin.  Example code:  \documentclass{article} \begin{document} \newenvironment{myenv}{\begin{equation}}{\end{equation}} \noindent $| \leftarrow$ this is the left margin. \begin{myenv} e ^{i \pi} + 1 = 0 \end{myenv} $| \leftarrow$ this isn't the left margin. \end{document}   Output:    Removing the newline after \end{myenv} solves the spacing problem, but the resulting code is not readable.  Of course, in this example I could just use the equation environment itself. My real issue involves a more complex custom environment that suffers from the same problem, and which also includes an equation environment within it. Possible to use draws from two distributions to get draw from distribution with density their product? 19MB/s Net Speed but Only 2MB/s Usable Hi so i just got internet a about a month ago and my net speed is 19MB/s, I have tested it on loads of sites they all say the same thing(19MB/s), but it wont use more than around 2MB/s i have tried downloading different ways, and with more than 1 download at a time and I still get capped at about 2MB/s. It affects everything like loading websites and playing games as well. So if I'm downloading (max 2MB/s) and I load up a web page, every thing slows down, the download speed slows and web sites take for ever to load up, what can it be that makes it thus, and speed test say's 19MB/s