How can I fix these errors I get when running APT?    Running ppa-purge gives error below  Updating packages lists W: The repository 'http://ppa.launchpad.net/chris-lea/libsodium/ubuntu xenial Release' does not have a Release file. W: The repository 'http://ppa.launchpad.net/fossfreedom/packagefixes/ubuntu xenial Release' does not have a Release file. W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file. E: Failed to fetch http://ppa.launchpad.net/chris-lea/libsodium/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found E: Failed to fetch http://ppa.launchpad.net/fossfreedom/packagefixes/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found E: Failed to fetch http://ppa.launchpad.net/mc3man/trusty-media/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found E: Some index files failed to download. They have been ignored, or old ones used instead. Warning:  apt-get update failed for some reason
When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?
Conjugate Variables, Noether's Theorem and QM What is the world's biggest Schrodinger cat? How do electromagnetic waves wave? Electromagnetic waves have a physical crest and trough as observed in microwaves and radio waves. I understand that is electromagnetic field vectors that wave, not the photon. But how do they wave? What does causes them to change direction? In The Winter Soldier, who did Peggy Carter say she married? When Steve Rogers visits Peggy Carter, she has a family photo on her nightstand and says that she married someone after Cap disappeared. Who did she marry? What happens to a Devil when its alignment is forcibly changed? According to PHB 122, in the section entitled Alignment in the Multiverse, for most creatures, "alignment is a moral choice." Myth says good-aligned gods created the races that are free to choose to be evil (they have free will), while evil-aligned gods created the races that are very inclined towards evil, since they were born to serve the evil god in the first place.  However, there are some types of creatures -- like devils -- which embody an alignment in its essence:     Alignment in the Multiverse, PHB 122      A devil does not choose to be lawful evil, and it doesn't tend toward lawful evil, but rather it is lawful evil in its essence. If it somehow ceased to be lawful evil, it would cease to be a devil.   My first thought was to not take this reading literally. The text could have meant that a neutral evil devil "isn't really a devil," but really, it's still a devil. It's a bit like imagining a guitarist who loses both hands. The loss of some part of a person's essence makes them not the same person anymore.  However, keeping my attention on it, I'm finding this text more and more difficult to interpret. If a devil "is lawful evil in its essence" then what does it mean when "it would cease to be a devil"? What happens to a devil when its alignment is forcibly changed?  There are , and a devil can be subject to some of them. I have a simple shutdown script which i want to run as root  shutdown -h +30; echo "succesfull";   I have followed these answer, to make my script root.  first I run this command  sudo chown root.root $HOME/test/test.sh sudo chmod 4755 $HOME/test/test.sh   and then made changes in sudoers  sudo visudo   added this command after this line %sudo   ALL=(ALL:ALL) ALL  eka ALL=(ALL) NOPASSWD: $HOME/test/test.sh   But when i executed my script its showing this error  shutdown: Need to be root succesfull Make mod_wsgi use python2.7.2 instead of python2.6? i am running Ubuntu 10.04.1 LTS  and it came pre-packed with python2.6 but i need to replace it with python2.7.2.   (The reason is simple, 2.7 has a lot of features backported from 3 )  i had installed python2.7.2 using  ./configure make make altinstall   the altinstall option installed it, without touching the system default version, to /usr/local/lib/python2.7 and placed the interpreter in /usr/local/bin/python2.7  Then to help mod_wsgi find python2.7 i added the following to /etc/apache2/sites-available/wsgisite  WSGIPythonHome /usr/local   i start apache and run a test wsgi app BUT i am greeted by python 2.6.5  and not Python2.7  Later i replaced the default python simlink to point to python 2.7  ln -f /usr/local/bin/python2.7 /usr/bin/python   Now typing 'python' on the console opens python2.7 but somehow mod_wsgi still picks up python2.6  Next i tried,  PATH=/usr/local/bin:$PATH export PATH   then do a quick restart apache, but yet again its python2.6 !!    Here is my $PATH  /usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games   contents of /etc/apache2/sites-available/wsgisite  WSGIPythonHome /usr/local   &lt;VirtualHost *:80&gt;      ServerName wsgitest.local     DocumentRoot /home/wwwhost/pydocs/wsgi     &lt;Directory /home/wwwhost/pydocs/wsgi&gt;         Order allow,deny         Allow from all     &lt;/Directory&gt;      WSGIScriptAlias / /home/wwwhost/pydocs/wsgi/app.wsgi  &lt;/VirtualHost&gt;   app.wsgi  import sys  def application(environ, start_response):     status = '200 OK'     output = sys.version      response_headers = [('Content-type', 'text/plain'),                         ('Content-Length', str(len(output)))]     start_response(status, response_headers)      return [output]   Apache error.log  'import site' failed; use -v for traceback [Sun Jun 19 00:27:21 2011] [info] mod_wsgi (pid=23235): Initializing Python. [Sun Jun 19 00:27:21 2011] [notice] Apache/2.2.14 (Ubuntu) mod_wsgi/2.8 Python/2.6.5 configured -- resuming normal operations [Sun Jun 19 00:27:21 2011] [info] Server built: Nov 18 2010 21:20:56 [Sun Jun 19 00:27:21 2011] [info] mod_wsgi (pid=23238): Attach interpreter ''. [Sun Jun 19 00:27:21 2011] [info] mod_wsgi (pid=23239): Attach interpreter ''. [Sun Jun 19 00:27:31 2011] [info] mod_wsgi (pid=23238): Create interpreter 'wsgitest.local|'. [Sun Jun 19 00:27:31 2011] [info] [client 192.168.1.205] mod_wsgi (pid=23238, process='', application='wsgitest.local|'): Loading WSGI script '/home/wwwhost/pydocs/$ [Sun Jun 19 00:27:50 2011] [info] mod_wsgi (pid=23239): Create interpreter 'wsgitest.local|'.   Has anybody ever managed to make mod_wsgi run on a non-system default version of python ? Inverse metric in linearised gravity combinatorics: sum of product of integer compositions When is a MOSFET more appropriate as a switch than a BJT? Manually installing a program on Debian I have installed Debian on my pc, but the problem is that at the moment I have no Internet connection to this pc. So, to install a program I have to manually downloaded from a pc with internet and then install it to the linux-debian computer.  The question is this: Is there a standard way to make the installation manually? Note that when I connect a usb flash with the program I want to install(that is:   cdparanoia_3.10.2+debian-10.1_i386.deb) and I try opening it I get the message:     Failed to execute child process “ar” no file or directory. Is it appropriate to buy a "thank you" gift for a PhD supervisor? The Crumple-Horned Snorkack is one of various weird and wacky things which Luna Lovegood believes in and most people (especially the ever-rational Hermione) don't. Now we know that Luna is a bit ... odd, and believes in a lot of nonsense; but on the other hand, Hermione's pooh-poohing isn't always to be believed either - Divination, for instance, is a real thing in the Potterverse.  Is it ever established for sure, in canon, in-universe, whether or not Crumple-Horned Snorkacks exist? I want to create posters for my poster presentation on a conference. What tools or LaTeX classes are available for preparing posters ? Castellation metal loop connector Here's a module with castellated pads attached to an eval board:  (source: ) Looking closely at the wires interfacing with the castellated pads, they're clearly soldered to the eval board. However, they don't look like they're soldered to the module, but rather they're being pressed against the pads with the tension in the wire. It also looks like the free end of the loops are protruding down into a channel cut in the PCB. Do these kind of connectors/metal loops have a name? Looking for a simple proof that groups of order $2p$ are up to isomorphism $\mathbb{Z}_{2p}$ and $D_{p}$ . I'm looking for a simple proof that up to isomorphism every group of order 2p (p prime) is either $\mathbb{Z}_{2p}$ or $D_{p}$ (The Dihedral group of order 2p).  I should note that by simple I mean short and elegant and not necessarily elementary. So feel free to use tools like Sylow Theorems, Cauchy Theorem and similar stuff.  Thanks a lot! Order of products of elements in a finite Abelian group We want to show that if $a,b\in G$ where $G$ is a finite Abelian group, we have  $\operatorname{LCM}(|a|,|b|) = |ab|$ given that $ab \neq e$.   How I approached this question was by saying let $\operatorname{LCM}(|a|,|b|) = L$. Then if we show that $L$ divides $|ab|$ and $|ab|$ divides $L$ then $|ab| = L$. Showing that $|ab|$ divides $L$ was fine. But then I am having trouble with the second part that is showing $L$ divides $|ab|$. For this, so far I have:  Consider $(ab)^{|ab|} = e = a^{|ab|}b^{|ab|} $  since we know $a \neq b^{-1}$ by assumption then we can conclude that $|a|$ divides $|ab|$ and $|b|$ divides $|ab|$. We know that $L = \frac{|a||b|}{\operatorname{gcd}(|a|,|b|)}$ from here can we conclude that $L$ divides $|ab|$? Why won't my taskbar display on my secondary monitor? On my secondary monitor (currently using Windows 10), my taskbar will barely show up. I've tried adjusting the resolution to lower ones (it recommends 1920x1080) and it doesn't do much. Is there a way to adjust the taskbar so I can see it?  That is about what I see. I could make it bigger via Snipping Tool and see my entire desktop on the picture but not normally. old Designjet 430 with Windows 10 Lack of Articles in Headlines Are there any rules as to an article before a noun in the singular in headlines please, i.e. lack of an article?       Description of Type of Investment