When a proton attracts an electron in the electromagnetic field is the proton "bending" the field?
Can all fundamental forces be fictitious forces?
How can momentum but not energy be conserved in an inelastic collision? Google Chrome Address Bar Font has gone too large, how can we reduce it Running Unity on my desktop (2*20" LCD displays), I initiated a standard daily update on my Ubuntu 14.04 LTS today and Google Chrome updated itself to Version 35.0.1916.114.  The URL address bar input now shows IMO a too larger font size which then proceeds to auto show in green. I prefer the smaller font size and have no need for 'gooey slime green' auto complete font colours. Any advice on how to revert back to smaller, generic Address font styling.  I use both FF and Chrome for numerous tasks, Chrome being my primary browser and I've checked my system Unity 'default' theme (Ambiance! LOL.. yes I'm tired of that also).  Thanks for sharing. Why are there non-visible objects in my final render? Have Blender on about 4 machines rendering animations. Just spotted on one of the machines its rendering something different from the actual scene that I have setup.    Top window shows a different set of layers objects to whats actually being rendered in the rendering window below.  In my scene contents, layers objects 1-5 are not visible, but these are the ones that look like they are being rendered.  The only thing I can assume is that perhaps it might be because I did not save the document before clicking render, but I would not have expected that behaviour (you dont need to save your word document before printing it).  Can anyone confirm why this is happening? What is the safest way to clean up /boot partition? I have 200 MB assigned for the /boot partition.  Whenever I try to update the kernel, I receive an error message that basically states /boot is full.  What can I do to cleanup /boot and remove/backup the older kernels? How can I strike through an expression (e.g. "2x") obliquely, e.g. from bottom left to top right, so as to indicate cancellation? With the \sout command from the ulem package, I can only strike horizontally. How to evaluate environment variables into a string in Python? I have a string representing a path.  Because this application is used on Windows, OSX and Linux, we've defined environment variables to properly map volumes from the different file systems.  The result is:  "$C/test/testing"   What I want to do is evaluate the environment variables in the string so that they're replaced by their respective volume names.  Is there a specific command I'm missing, or do I have to take os.environ.keys() and manually replace the strings? I'm writing a shell script for Linux, using Bash, to translate any video-file into a MP4. For that, I'm using avconv with libvorbis for audio.   Inside my script, I have a question for the user :   read -p "- Audio Quality [scale from -2 to 10] ? "     if [ -n "$REPLY" ] ; then     ABITRATE="-aq $REPLY"     fi   My "ABITRATE" string goes into the final avconv command-line.  But I would like to give the user the opportunity to answer that question with a value in Kb (Kilobit), and translate it into the scale that libvorbis uses. The "scale from -2 to 10" is this :   Quality Kbit/s  Normalization -----------------------------  -2      ~32        y  -1      ~48        y   0      ~64        y   1      ~80        y   2      ~96        y   3     ~112        y   4     ~128        n   5     ~160        n   6     ~192        n   7     ~224        n   8     ~256        n   9     ~320        n  10     ~500        n   I would like to know how to check if my $REPLY is in a range of number. For example, I would like my script to do something like this :   if [ $REPLY is a number between 1 and 32 ] ; then   REPLY="-2" elif [ $REPLY is a number between 33 and 48 ] ; then   REPLY="-1" fi   Is this possible (I'm willing to say 'yes of course, shouldn't be hard' but I don't know the syntax to use) ? Given an instance of System.Reflection.Assembly. Invalid Topology [Topoengine error] from ArcGIS for Desktop? Using ArcGIS 10.1 for Desktop, I'm trying to run the Identity function on two large data sets but it fails every time. I don't think it is a lack of hardware as I can run other processes on the same data sets.   I've already updated software, and added the 64 bit geoprocessing add-in, checked and repaired geometry, and done the fix in  (set ARCTMPDIR env variable to a writable local folder).   Executing: Identity DudleyStamp OA2011 "D:\Case Studies\National2\National.gdb\DudleyStampOA11" ALL "1 Meters" NO_RELATIONSHIPS  Start Time: Wed May 08 21:11:43 2013 Reading Features... Processing Tiles... Assembling Tile Features... ERROR 999999: Error executing function. The table was not found. The table was not found. [DudleyStampOA11] The table was not found.   The table was not found. [DudleyStampOA11]   Invalid Topology [Topoengine error.] Failed to execute (Identity). Failed at Wed May 08 21:45:41 2013 (Elapsed Time: 33 minutes 58 seconds)   Based on comments so far I tried copying data to new file geodatabase, and running the tool from ArcCatalog still get exactly the same error.  I have ordered 16GB of the fastest RAM my computer can take (I current have 4GB). I also have a 6 Core AMD Phenom II X6 1090T, SSD, and AMD Radeon HD 6970 Graphics Card. So I'm not sure what more hardware I can add.  I've also tried increasing the size of the page file which was a suggestion I found on Google with no effect. Adding x and y values while creating a label QGIS I'm trying to create a label on a map in QGIS.  I can open the setting where there are an X and Y button and a few other properties, like opacity and distance.  I'm pretty sure the problem is that I need to enter the proper X and Y coordinate here, but I don't know how to get to where it lets you enter the coordinates. I want to turn a photo in a engraving style picture, like  using GIMP and, if possible, then make an SVG out of it with Inkscape.  Can you recommend any filters/tools/plugins/tutorials for this? Find the set of $n\in\Bbb Z^+$ with $M=\{n,n+1,n+2,n+3,n+4,n+5\}$ partitionable into two sets Find the set of all positive integers $n$ with the property that the set $M=\{n, n + 1,n + 2,n + 3,n + 4,n + 5\}$ can be partitioned into two sets such that the product of the numbers in one set equals the product of the numbers in the other set.   If $n=1$ them $M=\{1,2,3,4,5,6\}$ and there is no such partition, so $n \ge 2$.  If the prime $p|n$ then either $p|2$ or $p|3$ or $p|5$ which means either $p=2$ or $p=3$ or $p=5$.  Suppose $n=2k$. Then $M=\{2k, 2k + 1,2k + 2,2k + 3,2k + 4,2k + 5\}$. I have no idea how to proceed. chpasswd apply changes in the chroot directory Let $R$ be a ring, where $a^{3} = a$ for all $a\in R$. Prove that $R$ must be a commutative ring. I can't seem to find an answer to this simple question, which I need for some compliance documentation.    On a default install of CentOS 6.5 (OpenSSH 5.3p1-94.el6), after how long of being idle will a user's SSH session be terminated?  I believe the following can be set to increase the idle timeout, but they are commented out by default.  $ grep -i alive /etc/ssh/sshd_config #TCPKeepAlive yes #ClientAliveInterval 0 #ClientAliveCountMax 3   Also, is there a command to dump a list of the current sshd settings?  I don't see anything in man sshd. What is the proper way to change the DNS IP? I suspect that the name server provided by my ADSL modem/router is buggy. Whenever I browse to a website for the first time in ubuntu, resolving the domain name takes at least 15 seconds.  To work around that problem, I changed the nameserver configuration in /etc/resolv.conf from 192.168.1.1 (my ADSL modem) to 8.8.8.8 (google's primary DNS). This seems to fix the problem, but unfortunately my changes to /etc/resolv.conf are overwritten by "NetworkManager" at each startup.  What is the proper way to configure the name server IP in ubuntu 10.4? Why is the Yang–Mills existence and mass gap problem so fundamental? Ref:   Can anyone please explain why the Yang–Mills Existence and Mass Gap problem is so important / fundamental to contemporary mathematics (and, presumably, theoretical / mathematical physics)?  If possible, please include the following in your answer / response:  (1) Why the problem is so fundamental / important - for both mathematics and theoretical / mathematical physics; (2) How the solution to the problem would impact research in the above two fields; (3) (If applicable) What progress has been made so far in resolving it; (references to papers, books, other resources would be helpful).  I'm an upper-level undergraduate in theoretical physics, and so am seeking an answer / response at such level. 'Sorry' as a replacement for 'Excuse me'? Is it ok to say 'sorry' where you otherwise would use 'excuse me'?  Example: "Sorry, but could you show me the way to the next train station?" What is the use of percent signs (%) at the end of lines? (Why is my macro creating extra space?) I see that the code in many packages and examples contains percent signs % at the end of (many) lines. What are they used for? Do they affect the parsing of those lines? if $f^{(n)}(x_0),g^{(n)}(x_0)$ exist and $\lim_{x\to x_0} \dfrac{f(x)-g(x)}{(x-x_0)^n}=0$ then $f^{(r)}(x_0)=g^{(r)}(x_0 )$ for all $0\leq r\leq n.$ Show:   if $f^{(n)}(x_0),g^{(n)}(x_0)$ exist and   $$\lim_{x\to x_0} \dfrac{f(x)-g(x)}{(x-x_0)^n}=0$$   then $f^{(r)}(x_0)=g^{(r)}(x_0 )$ for all $0\leq r\leq n.$   My attempt:  let n = 1,  since $f'(x_0),g'(x_0)$ exists then The taylor polynomial exists: $$T_{f,1}(x)=f(x_0)+f'(x_0)(x-x_0), \lim_{x\to x_0} \dfrac{f(x)-T_{f,1}(x)}{(x-x_0)}=0$$  $$T_{g,1}(x)=g(x_0)+g'(x_0)(x-x_0), \lim_{x\to x_0} \dfrac{g(x)-T_{g,1}(x)}{(x-x_0)}=0$$  Then, \begin{align} \lim_{x\to x_0} \dfrac{f(x)-g(x)}{(x-x_0)^n} &amp; =\lim_{x\to x_0} \dfrac{f(x)-g(x)+T_{f,1}(x)-T_{f,1}(x)+T_{g,1}(x)-T_{g,1}(x)}{(x-x_0)^n}\\ &amp;=\lim_{x\to x_0} \dfrac{f(x)-g(x)+T_{f,1}(x)-T_{f,1}(x)+T_{g,1}(x)-T_{g,1}(x)}{(x-x_0)^n}\\ &amp;=\lim_{x\to x_0} \dfrac{f(x)-T_{f,1}(x)}{x-x_0}-\lim_{x\to x_0} \dfrac{g(x)-T_{g,1}(x)}{x-x_0}+\lim_{x\to x_0} \dfrac{T_{f,1}(x)-T_{g,1}(x)}{x-x_0}\\ &amp;=\lim_{x\to x_0}\dfrac{T_{f,1}(x)-T_{g,1}(x)}{x-x_0}\\ &amp;=0 \end{align}  Then, \begin{align} \lim_{x\to x_0}\dfrac{T_{f,1}(x)-T_{g,1}(x)}{x-x_0} &amp;=\lim_{x\to x_0}\dfrac{f(x_0)+f'(x_0)(x-x_0)-g(x_0)-g'(x_0)(x-x_0)}{x-x_0}\\ &amp;=\left(f(x_0)-g(x_0)\right)\lim_{x\to x_0}\dfrac{1}{x-x_0}+f'(x_0)-g'(x_0) \\&amp;=0 \end{align} I am confused because  $\lim_{x\to x_0}\dfrac{1}{x-x_0}$ does not exist.