Why does a rigid body rotates about it's centre of mass?
Why does an unhinged body rotate about its centre of mass?
Is there a quick way to reset a .blend files windows and settings to default Whenever I download a .blend from someone all of the windows and settings are the way they have left them as it is saved in the file. It takes way to long to rearrange every window and toolbar to the way it is by default. Is there any tool or shortcut that can reset the UI to blenders default and just leave the actual contents of the file? The only way I could do this is by creating a new file and using link/append but this is not the best option. Problem working fontspec, babel and datetime with cyrillic I have discovered that fontspec with russian babel settings doesn't work with datetime package. I tried to compile such code:  \documentclass[a4paper,11pt]{article} \usepackage[T2A]{fontenc} \usepackage[utf8]{inputenc} \usepackage[main=russian,english]{babel} \usepackage{datetime} \usepackage[cm-default]{fontspec}  \begin{document} \today \end{document}   with a xelatex and got an error: Command \cyri unavailable in encoding EU1.  Is there any way to handle it?  UPDATE: I really bungle with charset in XeLateX. Thanks to egreg. I have removed fontenc and inputenc and used some cyrillic font, so my MWE now looks this way:  \documentclass[a4paper,11pt]{article} \usepackage[main=russian,english]{babel} \usepackage{fontspec} \setromanfont{PT Sans} \usepackage{datetime}  \begin{document} \today \end{document}   and I've got another error, if I used russian as a main language in babel: Undefined control sequence. \\monthnamerussian ...cyrm \cyra \cyrya \or \cyri  \cyryu \cyrn \cyrya \or \c...  Is it still because of XeLaTeX? In an extract I am dealing with, I have 2 datetime columns. One column stores the dates and another the times as shown.  How can I query the table to combine these two fields into 1 column of type datetime?  Dates  2009-03-12 00:00:00.000 2009-03-26 00:00:00.000 2009-03-26 00:00:00.000   Times  1899-12-30 12:30:00.000 1899-12-30 10:00:00.000 1899-12-30 10:00:00.000 Well, luckily I got this error on my test environment. I'm so scared about this error that I disabled all logon triggers I was using on production environment.   I created the famous logon trigger, and I put a database in offline mode just to mess with something else. Then I discover that because the trigger can't find the table, I can't access the instance anymore. There are plenty of questions related to this, but even doing everything I could find, I still can't acces the instance, not even with SQLCMD.  I'm doing this:  sqlcmd -S server\instance -U sa -P &lt;pass&gt;  -A   If I don't use -A I receive the famous error:  logon failed for sa due trigger execution.   If I use -A:     Sqlcmd: Error: Microsoft ODBC Driver 11 for SQL Server : SQL Server   Network Interfaces: An error occurred while obtaining the dedicated   administrator connection (DAC) port. Make sure that SQL Browser is   running, or check the error log for the port number [xFFFFFFFF]. .   Sqlcmd: Error: Microsoft ODBC Driver 11 for SQL Server : Login timeout   expired. Sqlcmd: Error: Microsoft ODBC Driver 11 for SQL Server : A   network-related or instance-specific error has occurred while   establishing a connection to SQL Server. Server is not found or not   accessible. Check if instance name is correct and if SQL Server is   configured to allow remote connections. For more information see SQL   Server Books Online..   Why i'm not able to connect to the sql server    sql server express here.  I could enable SQL Browser, but I still can't access it.  I don't think this question is duplicated because is not about the trigger, is about Why I can't access the server with SQLCMD. I pretty much know how to fix this. I just don't know how can I acces sql server without triggering the trigger. I am playing a bit around with Qgis 2.14.6 to understand how it deals with distance measurement.  I took a line-shapefile that I saved in 3 different coordinate systems (4326, 32642 and a national one that doesn't exist in Qgis yet).  Using 32642 and the national one, the length is quite similar (6442m vs. 6428m)  But using 4326 (unprojected WGS84), I get 8057m  In all cases, I just used the Field Calculator and introduced $length.  I was already positively surprised that the result using 4326 was in meters and not in degrees.  To calculate the distance on the dataset in 4326, I assume that Qgis does some kind of re-projection in the background. Does anyone know which one?   Shapefiles here if anyone wants to play around:   EDIT - adding more info after more tests  As you can see, now both my shapefile and the project are in EPSG:4326, so unprojected:    Here the rough measurement of my shapefile, with the Qgis measure tool:   When I use the field calculator, the preview gives me a value in degrees, while the result seems to be in meters:      This would mean that the function $length, like the measurement tool, always gives a result in meters, but using a very coarse approximation of the degrees => meters transformation:    Is this a bug? or should it really behave like this? I find it at best counter-intuitive (but maybe it's just me) and, at worse, completely misleading (it makes very little sense to use, everywhere on earth, the length of 1 degree at the Equator). Any input or opinion here? Should I open a bug report (at least for the inconsistency between the preview and the actual result)? Modules over commutative rings I'm trying to get my head around modules, and there's a problem that's bothering me regarding scalar multiplication from the left vs from the right.  In many books/articles I've read, the author may refer to a left $R$-module $M$, and then continue to talk of terms such as $xr$, where $x\in M$, $r\in R$. What is right scalar multiplication in a left module? Does it even make sense to talk about it?  I've been trying to show that over a commutative ring, right scalar multiplication and left scalar multiplication are the same thing, but I've not managed it so far. I've googled it to no avail, and I can't see why the distinction between left and right modules disappears when the base ring is commutative.  Thanks for any replies! Countability of disjoint intervals According this problem/solution set from an MIT class (http://ocw.mit.edu/courses/mathematics/18-100c-analysis-i-spring-2006/exams/exam1_sol.pdf), the assertion:  "Every collection of disjoint intervals in R is countable."  is True, because "every interval contains a rational number", and the rationals are countable.  It seems to me this should be False, with possible counterexample:  { [x,x] | x is an element of R}  ie the set of all singelton intervals on R. Why isn't this a valid counterexample? I develop a windows application and am curious whether it works via Wine. The application runs fine with Wine but I get no sound. In fact, I'm not sure whether my ubuntu installation has MIDI capabilities. The sound output settings shows "LFE on Separate Mono Output" one with "no amplifier" and another with "amplifier". They both function. I am using Ubuntu 12.04 as a client on virtualbox that runs on windows 7.  Thanks for any suggestion!  EDIT: virtual box hosted by windows 7, ubuntu running as a client in virtualbox. accessing loop variable within a loop How to set identity_insert to on in SQL Server Should I load an entire html page with AJAX? Do known-plaintext attacks exist for public key encryption? Proof of A ⊆ C and B ⊆ C ⇔ A ∪ B ⊆ C I know that this is valid because by thinking about it, you can see it's true, but I'm just not sure how I would go about actually proving it mathematically. I've kind of tried proof by contradiction, since that's what I use most of the time, but it doesn't seem to work.    In my mind, A ∪ B ⊆ C kind of just implies that A ⊆ C and B ⊆ C. Disable white background of pasted text in PowerPoint When I paste text from another source with "Keep source formatting option" into PowerPoint 2010 I receive a white background, that I don't want.    How can I make this text background transparent, so there would be just red text on purple? Performance differences between equal (=) and IN with one literal value Why is the observable universe so big? After Windows 10 Fall Creators Update, a svchost.exe instance is constantly using CPU time Since installing the Windows 10 Fall Creators Update, I have a svchost.exe process that is constantly using about 14​ % of CPU time:    This svchost.exe instance is responsible for hosting three services:    The CPU time is consumed by a thread inside that process that  cannot attribute to any of these three services:    Given that these three services are considered critical system services, it's hard to do anything about them. These services cannot be stopped or disabled by services.msc, and terminating the process triggers a bugcheck (CRITICAL_PROCESS_DIED). Disabling the Windows Defender Firewall through the settings UI does not reduce CPU usage.  I'm out of ideas. What could be causing this? How can I debug this further? Is there a workaround to stop these services?    Update: After some debugging with , we've isolated this to the Windows Defender Firewall service. Process Monitor shows that it's constantly accessing the registry:    A CSV export of a Process Monitor capture, filtered to that process, is available .  I’m still looking for a way to stop that behavior.    Update 2: Analysis with the Windows Performance Analyzer shows that most CPU time is consumed by code from rpcrt4.dll: Does going outside of range or line of sight after casting a spell have any effect? No room for a new \dimen I have this error message:  ! No room for a new \dimen . \ch@ck ...\else \errmessage {No room for a new #3}                                                 \fi   which I can not find a cure for. Export Windows 7 search results to a text file