Why is neutron slightly heavier than the proton?
What's with the very slightly larger mass of the neutron compared to the proton?
How to automatically fetch missing dependencies when installing software from .deb? Why are images formed? How do rays of light getting focused at a point create an image?  How are the information of object's shape and dimensions expressed as an image when light rays converge?  Is it understandable by solving wave equation for light? How do I detach a process from Terminal, entirely? I use Tilda (drop-down terminal) on Ubuntu as my "command central" - pretty much the way others might use GNOME Do, Quicksilver or Launchy.  However, I'm struggling with how to completely detach a process (e.g. Firefox) from the terminal it's been launched from - i.e. prevent that such a (non-)child process   is terminated when closing the originating terminal  "pollutes" the originating terminal via STDOUT/STDERR   For example, in order to start Vim in a "proper" terminal window, I have tried a simple script like the following:  exec gnome-terminal -e "vim $@" &amp;&gt; /dev/null &amp;   However, that still causes pollution (also, passing a file name doesn't seem to work). Is there a closed form expression for $1 + x + x^{4} + x^{9}+x^{16}+x^{25} +..+x^{k^2}$? We all know what the sum of a geometric series is  $1 + x + x^2 + x^3 + ... + x^k = \frac{x^{k+1} - 1}{x - 1}$ .  I was wondering if similar formulas exist in case the exponents  form some other sequence, for example are squares or cubes of positive integers? Simulating group_concat MySQL function in Microsoft SQL Server 2005? I have two JSON objects with the same structure and I want to concat them together using Javascript. Is there an easy way to do this? Navigating lookup relationships with dot notations, to retrieve field values I need to access the value from a roll-up field on my Opportunities, from it's related Opportunity Product.  When I use oli.Opportunity.Software_Line_Item__c the value retrieved is always null.  So I've also tried oli.OpportunityId.Software_Line_Item__c which causes an error in the compiler     Invalid foreign key relationship: OpportunityLineItem.OpportunityId   &amp; just to make sure that it's not the roll-up field calculation that's not working as expected, I've tested oli.Opportunity.Name which is also returning null.  I know this is basic but I don't have Eclipse installed so I can't check the correct reference to use. Could someone please let me know how I can navigate this relationship, to retrieve the value from the Software_Line_Item__c field? How to prove wave nature of large object? How to solve "permission denied" when using sudo with redirection in Bash? This looks a little bit like a variation on  but specific to the tags view.  Reproduction (app version 1.0.71):   Select any site (say Meta) from the sidebar Switch to the tags view using the top bar Choose a tag, any tag ( is nice)   optionaly refine your search with more terms  Go to any question found, go back   you end on the unfiltered tags view  Go back again   lucky you, your search is here Two icons on Unity Launcher on non-standard application launch I have an application which doesn't come from any Ubuntu repo (neither official, nor PPA) but available as tgz and supposed to be unpacked and ready to use. To be precise it is .   The problem is the  application when launched shows its own icon in Unity Launcher. After making a custom .desktop file and placing shortcut onto Unity Launcher (by dragging from the dash) and launching it I see two icons - one placed by me and another one with real application.  This is the .desktop contents:  [Desktop Entry] Version=1.0 Type=Application Terminal=false Exec=/opt/LightTable/LightTable Name=Light Table Icon=/opt/LightTable/core/img/lticon.png   One more thing. The /opt/LightTable/LightTable is bash script file and eventually /opt/LightTable/ltbin is being launched. I think this is the problem but have no idea how to fix the problem. sudo credential caching on by default Just installed a minimal ubuntu 12.04, then installed xfce4 and xinit from the command line after first boot.  Totally vanilla installation afaik.  I'm noticing that sudo caches the password until I issue sudo -k to clear it.  This is unexpected behavior in my mind.  I've run xfce4 before and don't recall credential caching being on, nor have I experienced it in the many previous ubuntu installs I've had over the years.  Is this a new feature of Ubuntu?  Is this something that's the result of the minimal install?  Is this an xfce default that's been added recently? How do I remap certain keys or devices? I'm searching for a way to remap certain keys in ubuntu.  i.e.   I'd like to change PgUp to Home or PgDown to End.  Does a built-in command or a tool exist reassign keys in Ubuntu/GNOME? I was editing a curve for hair, and pressed W to bring the specials menu and Subdivide it, but instead everything but the curve I had active dissapeared, and my cursor turned into a circle like the one from the circle select mode.  I'm guessing they changed the specials menu and I'm inside some unknown to me function, but I'm not sure how to turn everything back to normal. Compute the Riemann integral  $$\int_0^{\frac\pi2}\frac{\mathrm d \theta}{\sqrt{\sin \theta}}$$  It seems very difficult, I don't know how to go ahead.  Thank you very much for your help! Do "twice as high xxxxx as" , "twice as high" and "twice higher" mean the same thing? Total space of a finite rank locally free sheaf, Vakil's 17.1.4 & 17.1.G Can one executable be both a console and GUI application? I want to make a  program that can be run as a CLI or GUI application depending on what flags are passed into it. Can this be done?  I have found these related questions, but they don't exactly cover my situation: How FluentWait is different from WebDriverWait? How is the FluentWait is different from WebDriverWait? I am using WebDriverWait having the polling interval set to : 500 miliseconds. Still, WebDriverWait returns after some delay (i.e. 2 - 3 seconds after the element load is completed)? Any opinion here? I'm curious how USB device recognition works in Windows. I imagine it's something like this:   When you plug in a device, it tells Windows "here's my device ID to tell you what I am" Windows looks to see if any drivers have been installed that match that device ID. The driver probably tells Windows what the device should be called - like "BlackBerry Curve" or "Canon Printer" If so, it somehow associates that device with that driver Otherwise, it looks for a matching driver online (if you let it)   Am I right? If so, that still leaves some questions.   When you install drivers, where do they go? Are they files in a folder, or do they get added to the registry? What is Windows doing when it first recognizes the device, thinks, and finally says "your new device is installed and ready to use?" Where does Windows look for missing drivers? Is it in their own database? Do device manufacturers submit drivers to Microsoft for inclusion there?   Can anybody explain how this process really works? Also, do other OSes do this differently?