Steam does not start after install in 13.10

I have installed steam on my Laptop running 13.10, When I click on steam icon, it wont launch,So I have given "steam" command in terminal.Following is the output   Running Steam on ubuntu 13.10 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(0_client) Uploading dump (out-of-process) [proxy ''] /tmp/dumps/crash_20140402034337_1.dmp /home/saikiran/.local/share/Steam/steam.sh: line 755:  6814 Segmentation fault      (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$PLATFORM/$STEAMEXE" "$@" mv: cannot stat ‘/home/saikiran/.steam/registry.vdf’: No such file or directory Installing bootstrap /home/saikiran/.local/share/Steam/bootstrap.tar.xz Reset complete! Restarting Steam by request... Finished uploading minidump (out-of-process): success = yes response: CrashID=bp-1e1a9170-2ae6-46c1-bc74-3c0db2140401 Running Steam on ubuntu 13.10 64-bit STEAM_RUNTIME has been set by the user to: /home/saikiran/.local/share/Steam/ubuntu12_32/steam-runtime Installing breakpad exception handler for appid(steam)/version(0_client) Uploading dump (out-of-process) [proxy ''] /tmp/dumps/crash_20140402034339_1.dmp /home/saikiran/.local/share/Steam/steam.sh: line 755:  6943 Segmentation fault      (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$PLATFORM/$STEAMEXE" "$@" Finished uploading minidump (out-of-process): success = yes response: CrashID=bp-06b25061-5bb4-42c2-b835-bc2e92140401   I have tried removing ~/.steam/steam/appcache as indicated in other threads  I have installed Steam on Xubuntu 14.04 beta, still same thing happens.


How do I prepare patched drywall to be painted over?

I am in the process of painting my room. I have some big patches on the drywall. I am yet to begin painting that wall. Before i start i wanted to take advice. Is there anything i need to do with those patches so that after paint they are not visible?  Do i need to take special care of it?


1960s-70s short story: Shapechanging alien invasion scouts on Earth

I am looking to identify a story I read in the 1960s or 70s. It was about a scoutship that landed on Earth, prelude to an invasion force. Previous scouts had disappeared without a trace.  The crew members' names were descriptive of their function. I think the protagonist was called Pilot. They are shape-changers. One by one, the crew members defect, taking on forms of Earth creatures that fit their function and personality. Pilot tries desperately to complete the mission. One scene I remember is he assumes human form and walks into a building -- but is unable to blend in, I think because he forgets to form facial features.  He struggles to complete his crew's mission, barricading himself in a room? (perhaps to destroy the planet?) when he sees birds out the window. The people breaking in to stop him see only a large (white?) bird flying out the window, a bit awkward, but quickly gaining control of its wings and soaring away.  Help, please?


Well is adverb and known is adjective. As far as I know, it should not be hyphenated. For example: clearly impossible task, extremely powerful processor.


Can an object have 0 acceleration because its instantaneous velocity is 0?

If  an object has an instantaneous velocity of zero, does this mean that its acceleration is zero?


Random Ants Question from Interview Book: How to Compute Expectation of Maximum of Random Varibales

I know the following question has been asked by the following link:   But my question is more about computing the final result: expected value of the maximum of 500 IID random variables, and I highlighted my doubt in bold in the following:  Question:  500 ants are randomly put on a 1-foot string(independent uniform distribution for each ant between 0 and 1). Each ant randomly moves toward one end of the string (equal probability to the left and right) at constant speed of 1 foot/minute until it falls off at one end of the string. Also assume that the size of the ant is infinitely small. When two ants collide head-on, they both immediately change directions and keep on moving at 1 foot/min. What is the expected time for all ants to fall off the string?  Solution:   When two ants collide head-on, both immediately change directions. What does it mean? When an ant A collides with another ant B, both switch direction. But if we exchange the ants' labels, it's like that the collision never happens. A continues to move to the right and B moves to the left. Since the labels are randomly assigned anyway, collisions make no difference to the result. So we can assume that the two ants meet, each just keeps on going in its original direction. What about the random direction that each ant chooses? Once the collision is removed, we can use symmetry to argue that it makes no difference which direction that an ant goes either. That means if an ant is put a the $x$th foot, the expected value for it to fall is just x min. If it goes in the other direction, simply set $x$ to $1-x$. So, the original problem just becomes what is the expected value of the maximum of 500 IID random variables with a Uniform Distribution between 0 and 1. Clearly the answer is $499/500$. So my question is: how do we know the answer is $499/500$? What is the theorem or formula to get this number?


Can I upgrade from 12.04.5 (Precise Pangolin) to 14.04.5 (Trusty Tahr) and use Gnome (3.x or 2.x) as my main desktop environment?

(Important for readers and AskUbuntu editors: I know my 12.04 has reached its EOL, but I'm asking for an upgrade, so please do not set my question as off-topic.)  I'm using Ubuntu 12.04.5 LTS Precise Pangolin as dual-boot with Windows 7. I know that my installation has reached its End Of Life and I was wondering if I could upgrade from 12.04.5 LTS to 14.04.5 LTS, but with some modifications. My graphics card is not fully supported for the Unity 3D Interface, so I was wondering if I could upgrade to Trusty Tahr, remove Unity somehow and add GNOME (3.x or 2.x, whatever it installs) and use it as my main desktop environment. I have also tried GNOME 3 (using a Debian 8 live DVD) and my PC can handle that. With GNOME 2 (Classic/Fallback Session), no problems at all.  So, can I do so? Can I upgrade to 14.04 and use GNOME as my main desktop environment?  My computer specifications:  Dell Optiplex GX270 SFF (Small-Form-Factor)   Operating Systems: Windows 7 & Ubutnu 12.04.5 LTS Precise Pangolin Partitioning: Windows 7 (/dev/sda2, NTFS, 5.80/40.80 GB free)              dev/sda3 -> Extended Partition (Ubuntu + Swap)              Ubuntu (/dev/sda5, ext4, 5.02/14.00 GB free)              Swap Partition (/dev/sda6, linux-swap, 1020.00 MB) Motherboard: Dell Corp. 0YF936 RAM: 1024 MB (1GB) CPU: Intel Corporation Pentium 4 @ 2.40 GHz Graphics Card: Intel HD Graphics 82865G, 1280x1024 Hard Disk: Western Digital WD600BB-00CA   Thanks in advance,  Bajiru


Cannot open GUI editors in superuser mode

I was trying to edit my sources.list in order to add local mirror information. I am not comfortable with command line editors, so I tried using sudo mousepad /etc/apt/sources.list.  I got the following error report.  No protocol specified  (mousepad:4942): Mousepad-ERROR **: Cannot open display:    I tried several other editors such as gedit, kwrite etc. but I get similar error reports.  No protocol specified  ** (gedit:4957): WARNING **: Could not open X display No protocol specified Unable to init server: Could not connect: Connection refused  (gedit:4957): Gtk-WARNING **: cannot open display: :0   I am on a local 64 bit system running Debian Jessie.


Difference Between Linear Regression in Machine Learning and Statistical Model

I had the understanding that the major difference between machine learning and statistical model is, the later "assumes" certain type of distribution of data & based on that different model paradigm as well as statistical results we obtain (e.g. p-values, F-statistics, t-stat, etc.). But in case of machine learning, we don't bother about distribution of data and more interested in prediction.  When I was going through Mllib doc, I found for linear regression we are specifying a distribution. But Mllib is a machine learning package. So, I've the following questions:  1) Is my understanding between ML & statistical method is wrong?  2) Is spark is using statistical modeling for linear regression and GLMs?  Thanks!  Note: There are lot of wonderful post regarding the difference between machine learning and statistical method. But this more related to spark MLLIB.


I've got:   a CPU E5-2407 (quadcore Xeon 2.2GHz) 16GB of memory DDR3 RAID1 Intel520 SSD 240GB   My homemade applications are using a permanent PG connection on 7 pages (one called by customers as API, others called by a CURL bash loop with 10s timer) + website. The volume will go up to 1 million call per day on the API page (now it's around 1000 per day). The API page role is only to insert data in a table, handle by loop process afterwards.  I'll change the bash loop by a C program in maybe one month so the API page will be the only called using nginx (except website but it'll be a very very small volume compared to API).  What would you recommend as settings for processes/child processes/cache/buffer of nginx/PG/FPM ?  Thanks :)


Which of these is correct, “She doesn't has” or “She doesn't have”? And why?

She doesn't has a book. She doesn't have a book.  Why is the first sentence wrong? We use 'has' with singular, and 'she' is singular.


How to prove that the cardinality of the set of Borel sets is continuum?

Let $\mathscr{B}$ be the set of Borel sets on $R$, how to prove that $\overline{\overline{\mathscr{B}}}=\aleph$? That is ,  the cardinality of it is continuum?


Redirecting depends of Variables in Header

Issue  I've difficulties to understand if it is possible to do redirects depends of variable in Header using Domino server (R9).  AIM  Redirect all requests (for 1 particular website) to: https://www.domain  EXAMPLE incoming requests:   http://example.com http://www.example.com https://example.com   All 3 examples should be redirected to   https://www.example.com   Here is my setup   All requests come to "Load Balancer" and then it redirect requests to Domino Server. Load Balancer always (!) convert requests from HTTPS to HTTP, so Domino always receives HTTP requests. Load Balancer adds flag/variable to requests which have been converted from HTTPS to HTTP. Domino must redirect HTTP to HTTPS. My issue - I need to figure out how to verify variable in request and depends of it - do redirect to HTTPS or NOT. So far if I set redirect for all request - I receive a loop and I understand why.   Does anybody have an idea how to solve that only with Domino Server?  Possible solutions I know about   Setup one more server between Load Balancer and Domino, so it does redirect instead of Domino. Go with DSAPI. I really would like to avoid it, it requires development + maintenance.


how to prove an element is non-zero in a tensor-product

I was studying the following example from Atiyah & MacDonald's Introduction to Commutative Algebra:   Let $x$ be the non-zero element in $N := \mathbf{Z}/ 2\mathbf{Z}$, $M := \mathbf{Z}$, and $M' := 2 \mathbf{Z}$. The element $2 \otimes x$ is zero in $M \otimes N$, but non-zero in $M' \otimes N$. I suppose this can be seen by the fact that $2 \otimes x$ generates $M' \otimes N$, and the tensor-product $M' \otimes N$ is non-zero.   However, I was wondering, what one would do if that element weren't a generator of $M' \otimes N$. So my question is:   What are the methods to prove that an element is non-zero in a tensor-product of modules?   Thanks a lot!


Is there an idiom/phrase/word that means snubbing /ending contact with someone after you've used them as much as you can to your benefit?

Something close I have considered, but is not correct, is "Bite the hand that feeds you". The reason this is not correct is because this simply means someone (actively) treats their helper poorly, whereas the situation I want to cover is the person completely ignores or snubs them. I am looking for an idiom if possible that means completely snubbing someone that once helped you, especially someone the perpetrator depended on, or had a lot of frequent contact with before, but only because the perpetrator wanted to use the helper for their own benefit and advantage, then abandoning them / disowning them after they are no longer of any help to the perpetrator. Not looking for an idiom or word that describes the person (which would be an adjective), rather, I'd like a word or phrase that is a verb. Thanks


I need to prepare presentation about calculus, paying special attention for examination of function of one variable. I am not very advances in the topic, but I'm looking for book which contains interesting, not fundamental, examples from fields like continuity of functions, limits, differentiability.   Unfortunately, I didn't learn from english book (english isn't my national language), so books, from which I learned, contained examples for beginners, which could show just problem. According to differentiability there was just mention that, for example, function y=|x| is not differentiable in x=0, and I'm looking for examples not so obvious. For example Weierstrass function is interesting example in that field.  I didn't find book more complicated, different than basics for students.  This could be student's book or notebook. I ask for help because I have no experience with foreign books for analysis, calcus.  I will be grateful, if someone decides to help me and to recommend a book


Appropriate forum for software critique?

I understand and respect why StackOverflow will close or even remove some questions that are too subjective or not answerable with concrete facts and citations. This is a good thing, as it improves the richness of actual knowledge here and discourages flame wars and trolling.  My question is, is there a StackXXX variant focused on software critique? That is, entirely subjective discussions on the relative merits of this language or that tech stack, but with a bias towards informed debate as opposed to religious/flame war stuff?  As I explore new (to me) technology, I will sometimes hit Google to dig up a lot of opinions/discussions about that technology, in part to sanity check my naive reactions (e.g. maybe the initial learning curve is bumpy but it truly is worth the effort to grok it), and in part to discover the reasons a technology is the way it is. E.g. there was a conscious philosophy to trade off DRY for explicit; it follows the widely familiar pattern of the older Foo platform; it's like that "for historical reasons"... This can really matter to a developer as sometimes that smell your smelling is something your gut should trust, whereas sometimes the more knowledgeable perspective can underscore why tech X is worth a deeper look. Case in point, way back, it took me 3 subsequent attempts of rainy Sunday afternoons to get past the whitespace-as-semantics aspect of Python and realize it was not (SO NOT) as it appeared, a silly little toy language for doing silly little scripty things (though Python also excels at this :)  I haven't used it a lot and it may be new enough to not know how it may be used, but Quora.com is interesting for broader topics than just software and technology. I wonder if there is something more like StackOverflow for the philosophical and critical stuff.


Is there a way to create attribute subdomains in ArcGIS with clauses?  For example, if I'm editing a line feature class of pipes, I create a domain for the pipe type to be either plastic or metal. I want to setup another domain field "Rusted" with a yes/no value. When editing the data in ArcMap, if the pipe is metal, I should get a yes/no coded value option on the "Rusted" field. If it is plastic, I want the "Rusted" field to calculate N/A or perhaps give me other options.


True / false question about a Cauchy sequence in Real Analysis

I am solving assignments in Real analysis but I am unable to think about how I can solve this question.  Let $f: ( 0, \infty ) \to \mathbb{R}$  be a continuous function. Does $f$ maps any Cauchy sequence to a Cauchy sequence.  I tried by taking $ {x_n} $ and using |$x_n $ - $x_m$| <$\epsilon$ for all  $n, m > N$ ( $N$ is a natural number) . But how can I formulate the Cauchy sequence property of $x_n$  into $f(x_n$) ? I am unable to think about it. Any hints please?


Maximum social distancing of $n\geq2$ aliens on a planet of radius $R$

A spherical planet of radius $R$ is inhabited by $n\ge 2$ aliens. Due to the emergence of a novel deadly virus, the aliens must  practice social distancing, staying away as far as possible of each other. What is the maximum distance that can be achieved in terms of $R$ and $n$? If Euclidean distance is used (not Geodesic), the answer for $n=2,3,4$ the answer should be $2R$, $\frac{R}{\sqrt{3}}$, and $\frac{R\sqrt{6}}{4}$ respectively. Note: this problem is about maximum distance to the nearest neighbor, not about total distance, as wrongly marked as a duplicate.


I have the following page which I am trying to get the first line to be centered without affecting the other text. However, using \centerline{} seems to ignore the page margin and does not wrap text to fit the original margin.    \documentclass[12pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{graphicx} \usepackage{hyperref} \begin{document} \centerline{\textbf{\large{Appendix \hypertarget{Appendix}{F}: Construction of the Managerial Performance Indicator (MSI)}}}  \vspace{0.5 cm}  This text is just for the example \end{document}


This might seem like an odd question but I am really wondering. Up to now I used my trekking bike to commute to work and I never had any issues to leave it in the bicycle floor parking rack due to its factory default kick stand.  However I just bought a new mountain bike (XC) and I found out today that its tires barely fit into the bike stand. I had to apply brute force to get them in and out. In addition, it wobbled around and I had to use a tension belt to keep everything in place and from falling over.    Questions:   Could this have any negative effects on the tires? (I am taking the bike every single day to commute and I leave it for 9+ hours. I would like to use the MTB at least half the time.) Is there any more elegant solution to this problem rather than using brute force / tension belts apart from adding a kickstand and than putting the bike next to the rack?   I would like to avoid a kickstand for the reasons mentioned in other threads such as . Right now I am considering adding a kickstand and removing it after work if I decide to take a detour through rougher terrain.  P.S. Please note that I have seen plenty of mountain bikes lying on the ground after work in the past. (Due to wind or people bumping into them etc..) However I would like to avoid this if possible.


How do I use find when the filename contains spaces?

I want to pipe file names to other programs, but they all choke when the names contain spaces.  Let's say I have a file called.  foo bar   How can I get find to return the correct name?  Obviously I want:  foo\ bar   or:  "foo bar"   EDIT: I don't want to go through xargs, I want to get a correctly formatted string out of find so that I can pipe the string of file names directly to another program.


I was just wondering whether it makes a difference if I mysql_real_escape data more than once?  So if I escaped data in one part of my website, and then again in another part of code. Would this be a problem? Or make a difference?


How to check for existence of an INDEX on a column independent of used SQL database

Is there are unified way of how to check for the existance of an INDEX for a given column irregardless of the actual SQL database system used?  For MySQL one could for instance check for the existance using SHOW CREATE TABLE mytable. In the result there would be something like this if column mycolumn has an index: KEY 'Index_1' ('mycolumn').  Is this indicator KEY unified among all SQL database systems?  Are there better ways to check for an index?


What's a good back-up strategy for 1 desktop PC?

No, this is not a , nor is it a solicitation on  to backup or  and only a little bit about Where to backup and When to do it.  This is basically a strategy question: what, where and when all together. "How" is not really relevant: there are tons of back-up programs out there and they all do the same basic thing: make copies of data.  But the real question is: are these back-up programs making copies of the data important to you?  How should you install&run Ubuntu while safeguarding your data?  There is no "one size fits all" when it comes to computers, Ubuntu versions or a backup strategy, therefore I've split this up into 5 basic user types with each their own answer:       (or you're running in UEFI mode!)   And as the above does not fit everyone, one for the impatient:   !    So click one of the above links and go to your user type!  P.S. If you're running a server farm and you've read this question so far, I'm sorry: this is about a single PC, not a network, nor a server farm.


Selecting a range of hex tiles within radius of main tile

What I'm doing is pretty new to me, or at least I think it is, so I'm not really sure of what I'm looking for. Hopefully someone here knows =-)  Using a grid of hexes I generate, I can hover over any tile and it will highlight just fine. Now what I'm trying to figure out is how to allow for a radial selection of tiles around that hovered tile (brush size, basically), eventually allowing for a somewhat radial soft-selection gradient to allow falloff.  Each hex already knows about their neighbors, so currently I am hard-coding logic to handle a radius of 1, 2 or 3. I could duplicate that logic over and over to handle bigger radii but this is definitely not going to work for much longer, so I am trying to figure out a more efficient and cleaner way using loops/recursion/whatever.  Can anyone offer any pseudo-code or possibly a link that explains how to do this? Below is a (probably bad) attempt at what I think it would look like.  OnMouseOver(){     // This would select a radius of x hex tiles including center tile     this.SelectTile(3);  }  SelectTile(selectionRadius){     if(!this.alreadySelected){         this.Select();     }     for(int i = 0; i <= selectionRadius; ++i){         if(i < selectionRadius){             foreach(HexTile tile in thisTile.neighbors){                 tile.SelectTile(selectionRadius - i);             }         }     } }   Edit: I'm using this fantastic resource to help with hexes -  - so might there be a section on this page that may explain what I need and I'm just missing?


From my own personal experience, I don't like CAPTCHA when filling a form, especially encountering unrecognizable picture or calculation-required one.   When I submit some advises to the website, it's really annoying to fill a CAPTCHA at last. Always, I will give up my pulse to say something to the administrator or do some enquiries.  So here's the question. Does CAPTCHA really affect UX? And will a CAPTCHA-enabled contact form  be disliked by users?


what is the difference of append() and direct '=' assign value in python for reference initialized array

I met a problem when I use python to process my data, I want a three dimensional array, the first dimension is fixed at 5, the elements in second dimension are added dynamically, it`s type is array, the third dimension is how many number in the array, it is fixed at 4. code snippet is as follows:  three_d_array = [[]] * 5 # [[], [], [], [], []] three_d_array[0] = [1,2,3,4] # [[1,2,3,4],[],[],[],[]] three_d_array = [[]] * 5 # [[], [], [], [], []] three_d_array[0].append([1,2,3,4]) # [[[1, 2, 3, 4]], [[1, 2, 3, 4]], [[1, 2, 3, 4]], [[1, 2, 3, 4]], [[1, 2, 3, 4]]]   I know *5 will generate one copy but five references, but why '=' can break this relationship? '=' must assign new memory address for this array, I wonder it assign five copies for three_d_array[1:5] or just one for three_d_array[0]?


OSX and DHCP, forcing the local system to release a DHCP address

We have a heterogenous network that has many Apple products within it.   Recently, we had an issue with a duplicate IP that appeared to be interfering with someone's work.  Simple enough, right?  Not on OS X, apparently.  After digging around the Internet and a phone call with Apple Support, who suggested it was our routers (!!), I'm hoping someone here may have a deeper understanding of what's going on here.  I released the address from our internal Linux/ISC DHCPD server manually (it was deleted, server restarted).  I found and XML file generated at /var/db/dhcpclient/leases/en2-1,18:af:61:b7:7d:0 (for whichever device/MAC). Removing this file had no effect. OS X still insists on renewing the address it has had. Our default lease is 24 hours.  Rebooting the Mac after the above had no effect.  ipconfig, unplump/plumb the interface had no effect.  This leads me to believe that OS X is storing this information in some obscure database that I'm unaware of.   As for the documentation, well it basically sucks and didn't tell me much of anything.  Does anyone know how to force the Mac to forget about it's DHCP acquired IP address, completely, and request a new address from the server?   Thanks in advance.


Why is the direction of cross products of two vectors perpendicular to the plane? How is that possible?


I have questions about delta update:   Is delta updates world wide? What version of Android work with delta updates? Are all apps supported for delta updates? Is there any work to do to activate this feature?   I ask this question because I can't use this feature and still have to download whole size of app for updates


How to include a linear and quadratic term when also including interaction with those variables?

When adding a numeric predictor with categorical predictors and their interactions, it is usually considered necessary to center the variables at 0 beforehand. The reasoning is that the main effects are otherwise hard to interpret as they are evaluated with the numeric predictor at 0.  My question now is how to center if one not only includes the original numeric variable (as a linear term) but also the quadratic term of this variable? Here, two different approaches are necessary:   Centering both variables at their individual mean. This has the unfortunate downside that the 0 now is at a different position for both variables considering the original variable. Centering both variables at the mean of the original variable (i.e., subtracting the mean from the original variable for the linear term and subtracting the square of the mean of the original variable from the quadratic term). With this approach the 0 would represent the same value of the original variable, but the quadratic variable would not be centered at 0 (i.e., the mean of the variable wouldn't be 0).   I think that approach 2 seems reasonable given the reason for centering after all.  However, I cannot find anything about it (also not in the related questions:  and ).  Or is it generally a bad idea to include linear and quadratic terms and their interactions with other variables in a model?


Can't sudo unless I su as another user and then su back to my account?

user@greeneyes:~$ sudo apt-get install xdotool user is not in the sudoers file.  This incident will be reported. user@greeneyes:~$ su verelse Password:  verelse@greeneyes:/home/user$ su user Password:  user@greeneyes:~$ sudo apt-get install xdotool Reading package lists... Done Building dependency tree        Reading state information... Done The following additional packages will be installed:   libxdo3 The following NEW packages will be installed:   libxdo3 xdotool 0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 61.5 kB of archives. After this operation, 204 kB of additional disk space will be used. Do you want to continue? [Y/n]  Get:1 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 libxdo3 amd64 1:3.20160805.1-3 [20.5 kB] Get:2 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 xdotool amd64 1:3.20160805.1-3 [41.0 kB] Fetched 61.5 kB in 0s (136 kB/s)   Selecting previously unselected package libxdo3:amd64. (Reading database ... 168281 files and directories currently installed.) Preparing to unpack .../libxdo3_1%3a3.20160805.1-3_amd64.deb ... Unpacking libxdo3:amd64 (1:3.20160805.1-3) ... Selecting previously unselected package xdotool. Preparing to unpack .../xdotool_1%3a3.20160805.1-3_amd64.deb ... Unpacking xdotool (1:3.20160805.1-3) ... Processing triggers for libc-bin (2.27-3ubuntu1) ... Processing triggers for man-db (2.8.3-2) ... Setting up libxdo3:amd64 (1:3.20160805.1-3) ... Setting up xdotool (1:3.20160805.1-3) ... Processing triggers for libc-bin (2.27-3ubuntu1) ...   this is odd  user@greeneyes:~$ whoami user user@greeneyes:~$ sudo su user is not in the sudoers file.  This incident will be reported. user@greeneyes:~$ su user Password:  user@greeneyes:~$ whoami user user@greeneyes:~$ sudo su root@greeneyes:/home/user#


I was looking for a possibility to adjust the anchor of the text of a pin. Tikz does not allow this out of the box.   This question was already asked on the mailing list , Sept. 2009 without any reply till today or feature addition to pgf/tikz:  \documentclass[tikz]{standalone}  \begin{document}      \begin{tikzpicture}[          every pin/.style={anchor=west},          every pin edge/.style={anchor=west}]          \node [pin=60:test] at (0,1) {};          \node [pin={[anchor=west]60:test}] at (0,0) {};      \end{tikzpicture}  \end{document}   There is also a question with a suggested workaround here on  by defining an aligned pin style consisting of another node positioned at the end of the pin using \tikzlastnode:  \tikzset{     aligned pin/.style args={[#1,#2]#3:#4}{         pin={[inner sep=0pt,%               pin distance=#2,% new option, default = 3ex               label={[append after command={%                     node[inner sep=0pt,%                         xshift=-0.1cm,% modified, default = 0                         at=(\tikzlastnode.#3),%                         anchor=#1,%                     ]{#4}%                 }%             ]center:{}}%         ]#3:{}}%     } }   In this code, I have added a second unnamed option for pin distance within the square brackets.  MWE using the workaround showing the desired result:  \documentclass[tikz]{standalone}  \tikzset{     aligned pin/.style args={[#1,#2]#3:#4}{         pin={[inner sep=0pt,%             pin distance=#2,% new option, default = 3ex             label={[append after command={%                     node[%                         inner sep=0pt,%                         xshift=-0.1cm,% modified, default = 0                         at=(\tikzlastnode.#3),%                         anchor=#1,%                     ]{#4}%                 }%             ]center:{}}%         ]#3:{}}%     } } \begin{document} \tikz[pin distance=15mm, every pin/.style={fill=blue,text=white}] \node [circle,draw,     aligned pin={[west,3ex]0:X-Value},%     aligned pin={[west,3ex]45:Y-Value},%     aligned pin={[west,3ex]90:Z-Value}] {my circle}; \end{document}     I would like to add further options such as pin edge to adjust the style of the edge. Another addition would be xshift to finetune the position of the text (and yshift).  Is it possible to change the workaround to allow named options with default values if not specified?  Usage could look like this (without using necessarily all options):  node[aligned pin={[pin anchor=west,pin distance=1cm,pin edge={thick}]90:{txt}}]{};   If someone is interested in the implementation of the pin feature in tikz see  and do a textsearch for pin.  Update after answer by Qrrbrbirlbel:  To achieve almost the same result as my MWE use following code  % use preamble from Qrrbrbirlbel answer \begin{document}  \begin{tikzpicture}[every pin/.append style=draw, every pin edge/.style={thick}] \node[c] [ pin={[pin anchor=south west,pin edge pin anchor=south west,pin distance=6ex]90:Z-Value}, pin={[pin anchor=west,pin edge pin anchor=west,pin distance=6ex]45:Y-Value}, pin={[pin anchor=west,pin edge pin anchor=west,pin distance=6ex]0:X-Value} ] at (0,0) {}; \end{tikzpicture}  \end{document}     However, I would like to finetune the text positioning using inner sep=0 and a slight shift:  \newlength{\xshiftlength} \setlength{\xshiftlength}{0.5\widthof{Z}}   Following works:  \tikzset{   pin inner xsep/.style={tikz@pin@post/.append style={inner xsep=#1}} }   Apparently xshift cannot be added in the same way. It shifts more than only the text. How could a pin text xshift be added?


How can I explain to people that the phrase “off of ” is grammatically incorrect?

How can I explain to people that the phrase off of is grammatically incorrect?  I‘ve heard this phrase used a lot, especially by Americans (though they aren't the only ones).    In my understanding, off of should usually be replaced by off, as in,     I took the book off the shelf   as opposed to     I took the book off of the shelf   Am I wrong?  Or is there perhaps some simple way I can explain this to most people?


How can the total amount of energy in the universe be zero?

First of all, it is important to note that I'm not very savvy in neither general relativity nor any other area of expertise that answering this question may require. Therefore, I mean for the question to be answered in layman's terms.  Okay, now to the question itself: as far as I understand, for a given energy total in a system, its contents can theoretically be put into any other configuration of energies with the same total sum (if that makes sense). Therefore, if that sum is zero, the contents can be configured into, basically, 'nothing', which also has an energy total of zero.  However, with the universe, the only sources of negative energy are the fundamental forces. I think it may be reasonable to put all forces other than gravity aside, as only gravity is generated (sorry for funky wording) by something which itself is another source of energy (mass), and all the other forces eventually cancel out. If we also ignore the dark energy, we are left with a collection of masses that will eventually crunch together. Here is the problem I have with this: where will the mass go? Even if the potential energy of every point in the universe is zero (i.e. all the mass in the universe has now been smushed into a point), there is still mass to deal with, right?   I know I am probably wrong in many, many places in this question, but can you explain the general, underlying flaw behind my reasoning?


I have a jigsaw puzzle with 4 pieces.  Each piece is a different object in the scene.  I have an image that I want to span across the top face of each jigsaw piece.  How do you texture multiple objects with a single image?     Looking for a technique that will scale across 1000+ piece puzzles.


How can I prove that $2+\sqrt{-5}$ is irreducible in $\mathbb{Z}[\sqrt{-5}]$? I tried to show by $2+\sqrt{-5}=(a+b\sqrt{-5})(c+d\sqrt{-5})$ but I could not get a contradiction.


Newton's second law  $$\mathbf{F} = m\mathbf{a}$$  where $\mathbf{F}$ is the force, $m$ the mass, and $\mathbf{a}$ the acceleration, seems at first blush to be a simple tautology, since $\mathbf{F}$ and $m$ are not defined anywhere else in the formalism. Of course we can use the more general formulation  $$\frac{d\mathbf{p}}{dt} = \frac{d(m\mathbf{v})}{dt}$$  with $\mathbf{p}$ the linear momentum and $\mathbf{v}$ the velocity, but given the usual elementary definition of linear momentum $$\mathbf{p} \equiv m\mathbf{v}$$  this seems hardly an improvement.   Have I missed something? Perhaps in the Lagrangian or Hamiltonian formulation one can use Noether's theorem etc. to give a less trivial definition of $\mathbf{p}$? Or is there something even more elementary than that which I've missed?  Now, the law is clearly not tautologous in concert with some kind of force law, such as Coulomb's law or the law of universal gravitation. In that case we know what force means independently of mechanics. I'm just wondering if mechanics can be viewed as logically self-contained without recourse to such an addition.


Bash script not adding variables to session

I have a bash script that I have added as a startup application. It does a bunch of exports and alias assignment.  #! /bin/bash  alias devhm='cd ${DEV_HOME}; ll'; alias wlhm='cd ${WL_HOME}; ll'; alias dirch='watch --interval=1 "ls -la"'; alias vols='watch --interval=1 "df -h"'; alias svn-update='svn update --depth infinity ./*'; alias mci="~/mci.sh"; alias vncserver="vncserver -geometry 1680x1050"; alias ..="cd .."; alias hist="history | grep ";  export PROXY_HOST=proxy.my.setup; export PROXY_PORT=3128;  export LD_LIBRARY_PATH=$LD_LIBRARY_PATH/usr/lib/oracle/12.1/client64/lib; export ORACLE_HOME=/usr/lib/oracle/12.1/client64; export TNS_ADMIN=${ORACLE_HOME}/network/admin;  echo "DONE!";   But none of these values are available in my terminal sessions anymore. Even when I run the script straight into the terminal like so:  ./setup.sh   I see the "DONE!" prompt printed but no aliases or env variables are set.  If I copy and paste the contents of the file into the terminal the aliases and env variables are set.  I have tried adding a line to execute the script from .bashrc also but still no aliases or env variables set.  Any ideas what might be going on here? Also could anyone suggest a better way to have these env variables/aliases added to every terminal session?


Can Australians travel in certain Schengen countries for 90 days each?

I was recently informed by the Dutch immigration department that Australian and New Zealand citizens can travel to a large number of countries within Europe for 90 days each, essentially bypassing the 90 day Shengen limit. They said that the bilateral visa waiver agreements () allowed for this in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Italy, Luxembourg, The Netherlands, Norway, Portugal, Spain, Sweden and Switzerland.   Is this information correct? I am skeptical because I can't find any other information about this online, however they were adamant that this was the case and sent me an email with these details to give me proof.    Should I trust this information?  Edit: This is a different question to the "duplicate" linked as that question does not concern Australia, which obviously has different visa agreements to other countries.   Edit 2: I also found this website which seems to essentially confirm the information from the Dutch immigration department


If temperature is just the average kinetic energy of particles, why would moving air feel colder rather than warmer?


My Account disappeared yesterday from math and chem stack exchange.  I am very confused what happened was that I was told something strange happened to my account and I logged in and sure enough I have 1 reputation point on chem stack exchange and my math stack exchange got deleted.   Can someone explain what is happening?


Why doesn't a bird on an electric line get electrocuted? KVPY 2017

A bird sitting on a single high tension wire does not get electrocuted because       A) the circuit is not complete      B) the bird feet has an insulating covering.      C) capacitance of the bird is too small and the line frequency is too small.       D) resistance of the bird is too high.   This question is from kvpy exam that was held on 5th November, the official answer key says its (c) but thats tentative. Could someone please explain this?   I know this kinda questions dont go too well on stackexchange but this question has us intrigued as everyone expected the answer would be (a) or (d)


I have seen a proof involving technique beyond my course, I wanted to see anyone knows of any "elementary way" of proving this with just definitions of a set being closed, bounded and path-connected.


Dimensional Modeling of a Loan Approval Process and Fact Grain(s)

Context:  I'm modeling for a lending company and I'm modeling our loan approval process. I have some basic dimensions relative to our business figured out:   Time(day)    Account    Opportunity    Channel   And I and getting to the modeling of fact table(s) around the loan approval and credit decisioning process. An opportunity will get one or more "Credit Reviews" which have a series of steps they go through before arriving at a "Credit Decision". My instinct is to model the fact grain at the credit review step level or maybe the credit review level (or have one fact for each grain).  I'm working with some analysts who are used to using a “canned report”, one flattened table extracted from the source system that is at the opportunity level, and finds a "best credit review", and do a lot of their reporting from that.   I'm trying to explain my credit approval fact and how it would work and they think it's "overly complicated" and seem to want a fact table that is one-to-one with the opportunity, which is a dimension. And contains information on only the "best" credit review. In my mind that seems odd. I haven't run across a fact table that is at the same granularity (one-to-one) with a dimension. Have you ever heard of this? It feels like they are just trying to reproduce what they are used to, a non-dimensionally modeled data mart table at the opportunity level.   I'm trying to explain the utility of having a fact table that is at a higher granularity than they are used to in order to support many questions about the data rather than one, but I seem to be running into a wall getting this concept across. I’m not sure who is right here.  My question is this: Is it every appropriate, say in this situation, to model a fact that has the same cardinality as a dimension (one-to-one) with a core dimension? What would you recommend for this situation?


Collective term for a group of naive people

For cynical people, the word "cynics" is commonly used. For example, , one of the definitions is      cynical: (adjective) of or relating to the Cynics or their doctrines.   Is there a similar term for naive that can be used in a similar fashion? For example, something like     of or relating to the Naives or their doctorines.


Transit via South Africa for an undesirable person

I have a scheduled flight from Zimbabwe to the USA, but my flight will connect in South Africa. I am not sure whether I will be allowed to transit or whether I'm also banned from transiting. I overstayed and got an undesirable person ban.


Does getting live/neutral the right way round actually matter?

I was replacing an electrical socket in my (UK) house, and I noticed that the previous occupant had wired live and neutral backwards.  However, I've used a variety of appliances and devices on that socket in the past without any issue.  So - does it actually matter which way around they are connected?  As long as you obviously don't connect live from one part of the ring with neutral from the other, what difference does it make?


Shortcode outputs at the top of the_content

The shortcode produced by this function - a list of all sites in a multisite - outputs above the content in the loop, no matter where it is placed in the editor.  I've looked at the other related questions and answers on WPSE and realize that it has to do with the function using echo instead of return, but it's not as easy as replacing the instances of echo with return in the function below. Or adding echo=0 with a WP function like wp_list_pages()  Any ideas? Where is the function that needs to be returned instead of echoed?  // Output a single menu item function projects_menu_entry($id, $title, $link_self) {     global $blog_id;     if ($link_self || $id != $blog_id) {         echo '
';         if ($id == $blog_id) {             echo '';         }         $url = get_home_url($id);         if (substr($url, -1) != '/') {             // Note: I added a "/" to the end of the URL because WordPress             // wasn't doing that automatically in v3.0.4             $url .= '/';         }         echo '' . $title . '';         if ($id == $blog_id) {             echo '';         }         echo '
';     } }  // Output the whole menu // If $link_self is false, skip the current site - used to display the menu on the homepage function projects_menu($link_self = true) {     global $wpdb;      echo '
';      projects_menu_entry(1, 'Home', $link_self);      $blogs = $wpdb->get_results("         SELECT blog_id         FROM {$wpdb->blogs}         WHERE site_id = '{$wpdb->siteid}'         AND spam = '0'         AND deleted = '0'         AND archived = '0'         AND blog_id != 1     ");      $sites = array();     foreach ($blogs as $blog) {         $sites[$blog->blog_id] = get_blog_option($blog->blog_id, 'blogname');     }      natsort($sites);     foreach ($sites as $blog_id => $blog_title) {         projects_menu_entry($blog_id, $blog_title, $link_self);     }     echo '
'; }  // Adds a [bloglist] shortcode  function bloglist_shortcode($atts) {     projects_menu(false); }  add_shortcode('bloglist', 'bloglist_shortcode');


I have noticed in that in cases when listing certain things, the following convention is used     a, b, c, d and e   But I have also seen some cases where a comma is used before the and:     a, b, c, d, and e   Is there a specific usage case where such a convention comes to play?


I know that you can manage snapshots with the CLI with the command "tmutil". Unfortunately I don't know where exactly these snapshots are stored in the operating system? Edit: Suppose I don't have a backup hard drive at hand at the moment. Therefore I create a snapshot of the currently running hard disk with the command tmutil under the terminal. I can view these snapshots later with the command "tmutil listlocalsnapshots /" The only question is, where exactly are these snapshots on my hard drive? There must be a path where these files are saved? And I would like to know this


I came across this question in my math workbook, but wasn't able to solve it. Prove that the sequence $a_n = \frac{x^n}{n!}$ is bounded. This is my definition of bounded: $\exists M>0 \hspace{-1mm}: \hspace{5mm} |a_n|<M \hspace{5mm} \forall n\in\mathbb{N} $. UPDATE: I am aware I could prove convergence and then prove all convergent sequences are bounded, but I assumed there exists a direct method to prove boundedness using the definition (Hence this question was not meant as a duplicate).


Make "Loading the question failed" error more descriptive?

When a question fails to load, for network issues, phone issues, app issues, the question was deleted (for moderation or the user did), or the question really doesn't exist, we get this generic "Loading the question failed" dialog with a retry button. If the question has been deleted or doesn't exist, retrying to load the question will never work.   Is it possible to make this experience a little nicer, maybe providing why the app can't load the requested question? And if it retrying will never load the question, hide the retry button?


How many toys do I need to buy to get the whole set?

I'm collecting toys, they come in blind packs and there are 9 of them. Therefore for the first toy I have a 1.0 probability of getting a toy I haven't had before, then a 8/9, then a 7/9 and so on. On average, how many toys will I need to buy before I get the whole set?


Is there a difference between Bayesian and Classical sufficiency?

The title pretty much says it all. I wonder whether there is any difference in the way Bayesians understand sufficiency vs. the way orthodox statistics understands sufficiency, or are they equivalent?  If there is a difference, what is it?


I am given an old Ubuntu working system and the previous user had everything on his name so started turning it to my name as typing his name everywhere was bugging me. I tried:   $ usermod -l hussain darhamid   This turned the darhamid@darhamid:$ into hussain@darhamid:$  But I want hussain@darhamid:$ also changed to hussain@hussain. What should I do?   I am using ubuntu 12.04


Prove that for $n \geqslant 1,$ the integer $n(n+1)(2 n+1)$ is divisible by 6

Prove that for $n \geqslant 1,$ the integer $n(n+1)(2 n+1)$ is divisible by $6.$   My attempt. We enough to show that $2|n(n+1)(2 n+1)$ and $3|n(n+1)(2 n+1)$. Note that any integer $n$ is of the form: $2k$ or $2k+1.$  So $n(n+1)(2n+1)=2k(2k+2)(4k+1)$. Hence $2|2k(2k+2)$, that is $2|n(n+1)$.   How can I continue this proof? Can you help?


I've got a dataset of buildings roof segments in shapefiles. I need to sequentially number the roof segments from 1 to n of each building. Is there a way to do it with the QGIS field calculator? Actual:  Expected:  It's pretty similar to that question on arcpy:


"Where have I parked my car" or "where did I park my car"

I'm sometimes confused about the difference between present perfect and simple past sentences such as the ones in the title. In what kind of situation  do you guys say "Where have I parked my car" or " Where did I park my car?"   Thanks in advance.


How can you combine all lines that end with a backslash character?

Using a common command line tool like sed or awk, is it possible to join all lines that end with a given character, like a backslash?  For example, given the file:  foo bar \ bash \ baz dude \ happy   I would like to get this output:  foo bar bash baz dude happy


Why is the product map $GL_1(k)\times GL_1(k)\rightarrow GL_1(k)$ not continuous?

I am reading . I already have some experience with linear algebraic groups and invariant theory, yet one of the first exercises of the book has already confused me. In the first chapter, the book defines a linear algebraic group as a closed subgroup of some $GL(V)$, for some vector space $V$. Here, $V$ is a finite dimensional vector space over an algebraically closed field, $k$. Moreover, the topology on $V$ is the Zariski topology, so closed subgroup means Zariski closed. Immediately after this definition, the book says the maps $g\mapsto g^{-1}$ and (for fixed $h\in G$) $g\mapsto hg$ or $g\mapsto gh$ are homeomorphisms and warns that:  But the product map $G\times G\rightarrow G$ need not be continuous.  which follows by the exercise  Prove that the product map $GL_1(k)\times GL_1(k)\rightarrow GL_1(k)$ is not continuous.  However, this product map is clearly continuous! $GL_1(k)=k\setminus\{0\}$ as a variety; thus, every proper closed subset is finite. For a point $x\in k\setminus\{0\}$, the inverse image of $x$ equals $\{ (\lambda,\mu)\in GL_1(k)\times GL_1(k)\mid \lambda\mu=x\}$ which is a closed set in $GL_1(k)\times GL_1(k)$. Therefore, the inverse image of every closed subset is also closed. What am I missing?


Do you have any idea what is causing these artifacts on my cycles render?  I'm using a sun light source to illuminate the scene.  128 samples.  I've pasted a screenshot of the material that the artifacts are happening on


Overstayed my US visa for over 9 years, never got deported, can I return as a tourist?

I have a particular situation here, In March of 1997 I travelled to the US as a tourist and lived there illegally for almost 9 years. I was never arrested, or had any trouble with the law, I was never deported. I paid my taxed (had a TFN) had a job, bank account bought a house, etc. About 9 years ago I decided to leave as I was tired of living like that, not able to be legal, in fear of deportation and loosing everything. I also got married (to a person in the exact situation as me) we were able to legally migrate to Australia and now we are Australian citizens. We never returned our I-94s and in 2005 left through Mexico (walked through the border) so there are no records of us ever leaving. We have lived here in Australia for over 9 years.  OK so my question is... We have been thinking we would like to visit our friends and family back in the US now that we have a little girl. Is there any chance they won't let us in because they know we overstayed? We would be travelling with our Australian passports.


How to use a template specialization inside a non template class?

I've been searching for a few days already and can't seem to find a proper answer to my question.  In my program, I need to have a first class (D) that reads a file and instanciate some basic objects, that will be used to create some others. Once they're created, I call a parsing function with a collection of objects PC, which are NECESSARILY of class or child of class P.  To do so, I've implemented a collection of PC, that is merely an encapsulation of a vector storing PC objects.    In D.h  class D {     /*...*/     template<typename PC>     parse(vector<string> cmdline, V<PC> vpcs); }     In D.cpp  template<typename PC> parse(vector<string> cmdline, V<PC> vpcs) {      /* parse options */      /* check with a functor if PC is really of class (child of) P */      vpcs.push_back( PC(args) ); }     In V.h  template<typename PC> class V {     /*...*/     vector<PC> vpcs; }       In main.cpp  {     D des;     vector<string> cmdline;     V<P*> vps;     des.parse(cmdline, vps); }     Why do I want to do this? Because I'm writing a library and we have to let the future developers create their own child of P for specialized programs so I want to do something really generic (therefore : templated :)). I've already implemented and tested my function with class P, fully working, now I want to improve this. But I don't manage to compile my code or neither understand what I've been doing wrong.  (Also, for the record : first time using templates so I've read a lot of documentation but application is always a bit difficult!)  Thanks for your future answers and let me know if I can add more details!  EDIT : Okay, so the post given as "duplicate" (which I never read during my research, maybe not the correct keywords I typed in?) helped me for one thing but in fact it was not this problem at all. I had another one that I manage to resolve. In fact, I intended to have a collection of pointers, so instead of passing as PC the class*, I decided to pass only the class and just create the smart pointer inside a method of my templated "vector" class. Now it works, thank you all :)


Searching through ODT documents without opening them?

Let's say I have 2000 .ODT files. Their names are random numbers. How do I go about searching for, let's say, "pricing list"? How do I find the document I need without opening all of them one by one and checking to see if it's the right one?  Is there some program to search through the words in the documents without opening them?


How to check if alias is not replacing an actual command?

How can I know if an alias I make (in .bash_aliases) is not replacing an actual command by same name? I don't want to do such things by accident.  (I looked in "Questions that may already have your answer" and "Similar Questions" but did not see matches)  I'm asking because I feel there is no warning given by the system (Ubuntu 13.10).


What is the meaning of "meaning of life" and why do people seek it?

One of the oldest questions is "What is the meaning of life?". But what does the concept of "meaning of life" actually mean? What does it mean for something to be the "meaning of life"?  And why is it so important for many people to have it?  The "meaning of life" is often equated with the "purpose". But then again, purpose of what and for what? If one assumes that it is the purpose of life, the purpose of one's (earthbound or otherwise) existence, then the second part of the question still remains - who benefits from having this purpose? There are two possibilities:   One benefits from one's own existence. Somebody or something else benefits from one's existence.   One benefiting from one's own existence is related to "creating your own meaning of life", but most of the time when "What is the meaning of life?" is asked, the second type of this answer is implicitly assumed (and also, "creating your own meaning of life" might be ).  However, insisting on the second type of the answer leads to question: What is the purpose of having a purpose? Why do so many people seek and need the "greater" purpose such that they themselves aren't the ones who primarily benefit from such a purpose? I fail to understand the urge to have the reason to exist other than for self.  So, what does the concept of the "meaning of life" actually mean?  Just to be clear: I'm not asking here "What is the meaning of life?", but what does that question mean, what do people have in mind when they ask that question.


I left some ground meat in the refrigerator on a plate uncovered for 2 days, would it still be good to use it doesn't look like there is anything wrong with it? Answer asap please.


Working with texturing/shading a spaceship in Cycles when I noticed that the transparent shader isn't being transparent.  Ship with plain diffuse:   And then ship with transparent shader applied:   Different angles shows more/less of the spaceship being in that weird blackness.


How do I use the tooltip to create keybinds?

The specific command I'm trying to set is bpy.ops.object.origin_set() which sets the origin of an object which is bound to default to Ctrl +Shift+Alt +C  This doesn't work:


I updated the image in my Gravatar but my old picture still shows up.  Is this a cache issue?  Do I need to log out and then log back in?


When I launch Steam through Wine, no text is shown, just buttons. I am running Wine version 1.6. How do I fix this?


Is a finite, surjective and generically one to one morphism birational?

Let $X \rightarrow Y$ be a finite surjective and generically one to one morphism between algebraic variety of characteristics $0$. Is it biraitonal? This question is from the answer of Jason Starr , where he asserted the answer of my question is yes. While he said that this is false in positive characteristics case. How will the counter example be like?


How connection helps us to identify two different vector spaces?

I know that section of $TM$ is a vector field on manifold. And I understand that we need a connection to differentiate vectors that live in two different spaces. But still couldn’t grasp the idea how defining the connection that way will allow us to somehow compare or connect those spaces. Like in affine connection: It’s  a bilinear map that sends two vector fields to another one. But how this connection help us to compare the vector space at point $p$ to vector space of point $q$?


Wouldn't gravitons themselves theoretically be affected by gravity?

(I wrote this using the assumption that the graviton exists, which I know is not necessarily true; this is asked from a theoretical standpoint)  It is my understanding that General Relativity states all massive and/or energetic particles must be affected by the curvature of spacetime; this stipulation aligns with all known elementary particles. I understand that the graviton, being a particle that reliably interacts with photons, is going to be virtually impossible to detect experimentally. It is almost certainly massless and of a remarkably low energy, but it must possess energy nonetheless. As such, shouldn't gravitons themselves be affected by gravity, creating a paradox in which (increasingly virtual ?) gravitons must interact with other gravitons? Also, assuming that our conception that massless particles always travel at the speed of light holds true for gravitons, wouldn't gravitons themselves not be able to escape from a black hole, annulling the gravitational force of the black hole in the process?


What is the difference between "Build and view" and "Compile"?

In TeXstudio, what exactly is the difference between Build and view (F5) and Compile (F6)?


Meaning of 2.04 standard errors? Significantly different means when confidence intervals widely overlap?

The image below is from  in Psychological Science. A colleague pointed out two unusual things about it:    According to the caption, the error bars show "±2.04 standard errors, the 95% confidence interval." I've only ever seen ±1.96 SE used for the 95% CI, and I can't find anything about 2.04 SE being used for any purpose. Does 2.04 SE have some accepted meaning?  The text states that planned pairwise comparisons found significant differences for mean startle magnitude in error vs. correct predictable trials (t(30)=2.51, p<.01) and error vs. correct unpredictable trials (t(30)=2.61, p<.01) (the omnibus F test was also significant at p<.05). However, the graph shows the error bars for all three conditions overlapping substantially. If the ±2.04 SE intervals overlap, how can the values be significantly different at p<.05? The overlap is large enough that I'm assuming that the ±1.96 SE intervals also overlap.


How to check if file exists after serialization - C#?

I use this function to save my game state into file with serialization:  public void SaveForX86 () {     UpdateGameState();     try     {         BinaryFormatter bf = new BinaryFormatter();         FileStream fs = File.Create(Application.persistentDataPath + Helper.GAME_DATA_FILE_NAME);          GameData data = new GameData();         data.experience = experience;         data.score = score;         data.winPercent = winPercent;         data.tasksSolved = tasksSolved;         data.correct = correct;         data.additions = additions;         data.subtractions = subtractions;         data.multiplications = multiplications;         data.divisions = divisions;         data.useAddition = useAddition;         data.useSubtraction = useSubtraction;         data.useMultiplication = useMultiplication;         data.useDivision = useDivision;         data.minRange = minRange;         data.maxRange = maxRange;         data.longestChain = longestChain;         data.useIncrementalRange = useIncrementalRange;         data.gameStateDirty = gameStateDirty;         data.longestTaskInSeconds = longestTaskInSeconds;         data.overallTimeInSeconds = overallTimeInSeconds;         data.operandsSign = operandsSign;         data.difficulty = difficulty;          bf.Serialize(fs, data);         fs.Close();     }     catch (Exception ex)     {         Debug.Log(ex.Message);     } }   I would like to check whether the file was created. How can I do that in this case?


How does a wheel balance itself during circular motion?

A wheel (or any ring of considerable mass) hardly balances itself when it is placed vertically on ground, but when we roll it along the ground it balances itself. What causes this effect? I guess its because of the centrifugal force generated by the circular motion of the wheel that makes the outer surface of the wheel rim to stick to the ground, but I am unsure whether this is the correct explanation.


I posted a comment on an answer yesterday (here:  ) And today I got notification that my reputation had dropped by 1 because of that comment.... I'm just curious what happened that caused this haha, can you downvote comments? Thanks!


If 3 integers are divisible by 67 prove that determinant of matrix of their digits is also devisible without direct calculation

So we got three numbers: \begin{align} 737 \\ 871 \\ 938 \\ \end{align} are divisible by 67. Easy to check. Our numbers consist of: \begin{align} N=\mathrm{X}\!\cdot\!\mathrm{10}+\mathrm{Y}\\ 737=\mathrm{73}\!\cdot\!\mathrm{10}+\mathrm{Y} \end{align} So signature of divisibility is: \begin{align} if \ \ \mathrm{X}-20\!\cdot\!\mathrm{Y}\ is \ divisible \ by \ 67 \ then \ N \ is \ also \ divisible \\ 73-\mathrm{20}\!\cdot\!\mathrm{7}=-67 \ is \ divisible  \ by \ 67 \end{align} The same with other two integers. And in this case we need to prove that determinant: \begin{vmatrix}7&3&7\\8&7&1\\9&3&8  \end{vmatrix} is also divisible by 67 without calculating determinant itself! So what is the main idea here? I see, that all digits here are co-factors of integers itselves, so maybe we now should use properties of Laplace formula...but I can't catch how...


Cross-referencing problem if counter of theorem-like environments is shared

The problem is when i share numbering the \cref can't show name, even by \crefname and \autoref show all name Equation.  Here is an MWE:  %&latex \documentclass{amsart}  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % If you want to insert other packages. Insert them here \usepackage{amsthm} \usepackage{hyperref} \usepackage[nameinlink]{cleveref} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  \begin{document}  \numberwithin{equation}{section}  \newtheorem{The}[equation]{Theorem} \crefname{The}{Theorem}{Theorems}  \newtheorem{Dfn}[equation]{Definition} \newtheorem{Lem}[equation]{Lemma} \newtheorem{Prs}[equation]{Proposition} \newtheorem{Crl}[equation]{Corollary} \newtheorem{Rmk}[equation]{Remark}  \begin{The}\label{T1}    Assume ... \end{The}  ... \begin{Dfn}\label{D1}    Assume ... \end{Dfn}  ... \begin{Lem}\label{L1}    Assume ... \end{Lem}  ... \begin{Prs}\label{P1}    Assume ... \end{Prs}  ... \begin{Crl}\label{C1}    Assume ... \end{Crl}  ... \begin{Rmk}\label{R1}    Assume ... \end{Rmk}  \begin{equation}\label{E1}    Assume ... \bigskip \end{equation}  \noindent \cref{T1} \\ \cref{D1} \\ \cref{L1} \\ \cref{P1} \\ \cref{C1} \\ \cref{R1} \\ \cref{E1} \\  \noindent \autoref{T1} \\ \autoref{D1} \\ \autoref{L1} \\ \autoref{P1} \\ \autoref{C1} \\ \autoref{R1} \\ \autoref{E1} \\  \end{document}     How can I solve it?


This integral is driving me nuts for quite some time: $$\int_0^1\frac{x^7-1}{\ln x}dx$$ Mathematica spits out the result in a second ($\ln 8)$. My attempts revolved around substitution: if you introduce $u=\ln x$ you get something like: $$\int_{-\infty}^0\frac{(e^{7u}-1)e^u}{u}du$$ ...which looks equally hopeless as the starting integral. The other attempt was to try some kind of recurrence relation between $I_n(x)$ defined as: $$I_n(x)=\int\frac{x^n}{\ln x}dx$$ ...or to find a recurrence relation between $I_n$ defined as: $$I_n=\int_0^1\frac{x^n-1}{\ln x}dx$$, but the things have spiraled out of controll pretty fast. Also attempts to use Taylor explansion proved to be a dead end. Any hints?


U(N) and SO(N) are quite important groups in physics. I thought I would find this with an easy google search. Apparently NOT! What is the Lie algebra and Lie bracket of the two groups?


Similar questions have been asked before, but not quite the same, and no suitable answer found. I rendered a scene on one computer.  Some texture images were on a USB memory stick plugged into "G:" on that computer.  They didn't get packed with the .blend file unfortunately. Now I'm rendering that .blend file on another PC.  I have the memory stick, with those images.  I just want to put those images into the .blend file, and save it all packed together.  So can render that .blend file on any PC.  If someone could explain how please, in simple noob steps, I'd be very grateful. The .blend file is not reading those images on the USB stick, because on this PC the USB port is H: instead of G: Maybe could trick it into being a G: somehow, but that's not really the aim.  Thanks Edit:  I can go to the Material Node for the missing texture, click the folder icon, and re-locate the texture image, and can render the scene properly.  But still, when saving the .blend file, it will not pack that image into the .blend file, even with "Automatically pack into .blend" selected.  So rendering on another PC will run into same problem.


"As has been seen/shown/etc": What kind of grammatical category does it belong to?

It is evident that expressions like "as has been seen" make reference to something already mentioned before. However, why is there no pronoun? why not, for instance, "as IT has been seen"? On the other hand, what kind of grammatical category does it belong to?


Can the DM force player vs. player social checks?

Last session, my DM made me roll a Deception check against another player. I failed the roll, and as a result I was forced to reply a specific way and reveal information I otherwise wouldn't have revealed to the other player.  Now I know player-vs-player social dice checks aren't a thing and players aren't supposed to roll against each other because that takes away the players' choice and autonomy. I rolled it once because I am of the view that you roll with the punches during the game and air out any issues that you have after the session.   I confronted the DM about this, saying I was under no obligation to obey any social checks that he demanded I make against other players. As even :     There are three skills in the game that pertain to social interaction, especially when you're dealing with non-player characters. There's the persuasion skill, the deception skill, and the intimidation skill. I often get asked, are these skills meant to be used against player characters? And honestly they're not, because so much of how a player character talks and feels is really just up to the player's decision. We don't want dice to override the characterization that a player is bringing to their character. So these skills are mostly intended to be used on non-player characters, whether by player characters or by other NPCs   (Emphasis mine.)  So I told him that in the future, I will not obey any social checks of this nature that he wants me to make against player characters, as that’s going against the core principles of D&D.   He then said that I do not have to do so, but then I will just auto-fail the check. He didn't expand on what would happen if I "auto-fail".   Is a DM allowed to force a player to make social checks against other player characters? If the player fails, are they mandated to respond how the DM says they must?


Does somebody know how to register punch with commands? I want to execute a function when player punch other player or mob


Url in reference clickable but with link truncated

I have a problem with a references using BibTeX and IEEEbib. In my bibliography file (in the subfolder bib) there is this a reference with howpublished that produce this output:  @misc{allison2012simulation,   author = {Allison, James T.},   title = {Simulation and Animation of a Quarter--Car Automotive Suspension Model},   howpublished = {\url{http://www.mathworks.com/matlabcentral/fileexchange/35478/}},   year = {2012},    note = {[Online; accessed 25--March--2015]} }     Note that in the figure that the URL is clickable, but wrong because truncated at the end of line. The second part of URL is not clickable.  This is the references results that I obtain. All is right, but the link in PDF is not http://www.mathworks.com/matlabcentral/fileexchange/35478/, but only http://www.mathworks.com/matlabcentral/ truncated to the end of line.  The essential document is:  % !TeX spellcheck = en_US \documentclass[a4paper]{article} \usepackage{amsmath,graphicx,cite} \usepackage{epstopdf,epsfig,tikz,mathtools,caption,subcaption,amsfonts} \usepackage{url} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \input{ushyphex}  \begin{document} My citation~\cite{allison2012simulation}.  \bibliographystyle{bib/IEEEbib} \bibliography{bib/suspension}  \end{document}   What is the way to fix it?


How can I configure X11 so I can independently set the DPI for each monitor?

I am not just asking how to change the DPI of X11 as a whole, but instead how to make each monitor run on a separate DPI. I am trying to use two 900p monitors (19 inch) and one 720p TV (30 inch).


So I am making a program that takes in polynomial functions and does different things with it.   Right now, I am trying to make a method that checks the Polynomial that is input, which is stored as an ArrayList, and condensing it so everything with the same exponent gets added together.  I keep receiving a NullPointer Exception whenever I run the program, and I am not sure why I am receiving this. I know what the error means, but I have looked through my code and cannot see why the Polynomial is being seen as null.  This is my constructor  public ArrayList<PolyTerm> terms;  public Poly(ArrayList<PolyTerm> terms) {     sort(terms);     condenseExponents();     this.terms = terms; }   And in my main class I have my Poly objects created like this:  PolyTerm poly1 = new PolyTerm(4, 3); PolyTerm poly2 = new PolyTerm(-3, 1); PolyTerm poly3 = new PolyTerm(15, 3); PolyTerm poly4 = new PolyTerm(7, 2);  PolyTerm poly5 = new PolyTerm(14, 12); PolyTerm poly6 = new PolyTerm(2, 0); PolyTerm poly7 = new PolyTerm(19, 2);  ArrayList<PolyTerm> terms = new ArrayList<>();     terms.add(poly1);     terms.add(poly2);     terms.add(poly3);     terms.add(poly4);  ArrayList<PolyTerm> terms1 = new ArrayList<>();     terms1.add(poly5);     terms1.add(poly6);     terms1.add(poly7);    Poly test = new Poly(terms); Poly test2 = new Poly(terms1);   Where the first thing being taken in by the PolyTerm is the coefficient, and the second thing being taken in is the exponent.  So back to the Poly class.  In my constructor, I call condenseExponents() which is meant to condense to ArrayList and combine the coefficients of all similar exponents. Here is that method  private void condenseExponents() {     for(int i = 0; i < terms.size() - 1; i++)     {         for(int j = i + 1; j < terms.size(); j++)         {             if(terms.get(i).getExponent() == terms.get(j).getExponent())                 terms.set(i, new PolyTerm(terms.get(i).getCoef() + terms.get(j).getCoef(), terms.get(i).getExponent()));                 terms.remove(j);         }     } }   The NullPointer Exception keeps being thrown on the first line of the for loop in that method.  Does anybody know why?


Extracting points from polygonz geometry in PostGIS using Python

I have a 1282 buildings as 14684 polygonz surfaces in Postgis. I want to create grid on these surfaces. So, for this purpose I need to extract vertex points for every polygonz geometry in database. To access database I am using pyscopg2 adapter of postgresql.   How can I extract vertex coordinates from polygons? Because I will use these points to create new ones on these surfaces


Question regarding matrices with same image

Let $A$ and $B$ be $m\times n$ matrices over $\mathbb{Z}$ such that image($A$) = image($B$), where $A$ and $B$ are considered as maps $\mathbb{Z}^n \rightarrow \mathbb{Z}^m$. Does there exist an invertible $n\times n$ matrix $P$ such that $A=BP$? what happens if we consider the matrices to be over $\mathbb{Q}$ instead of $\mathbb{Z}$?  I would prefer some hints instead of full answer.  Thanks in advance.


It's my first question there so please don't be so cruel .   I've got problem with my program , it means i don't know why i have got NullpointerException , anybody knows why ?   My code : `package ex2;  public class Screen extends JPanel {      private BufferedImage image ;      private Timer tm ;      private Graphics g ;     private static int index = 0 ;      private ArrayList<String> paths = new Test().getArrayList();     public Screen(){         System.out.println(paths);         String interval  ;          interval = JOptionPane.showInputDialog("Please write time interval "                 + "between images in miliseconds");         tm = new Timer(Integer.parseInt(interval), new ActionListener() {              @Override             public void actionPerformed(ActionEvent e) {                 try {                     paint(index);                     index += 1 ;                     if (index >= paths.size())                         System.exit(index);                      } catch (IOException e1) {                                       e1.printStackTrace();                 }                                                            }         });         tm.start();     }     public void paint(int i) throws IOException{         image = ImageIO.read(new File(paths.get(i)));         g.drawImage(image, 40, 30, image.getWidth() , image.getHeight() , null);     } }


Using a 360 rotation to drive another object so that it rotates 0-180 and then again 0-180

I've got a bit of a remapping problem with my driver setup. Driver disk rotates 360 degrees (or more) Driven disk should match the driver for 0-180 degrees. Driven disk should then rotate again from 0-180 degrees for the 180-360 degrees of the driver object. Its basicly a question of mapping the rotation from one object to another with the rule that the driven object is always rotating 0-180 degrees, never 180-360. It would be especially great if this works for driver values beyond 360 as well. Could this be done? Im guessing it would need a scripted expression, but perhhaps there is a simpler way.


How to improve boolean modifier on SVG logo

Rookie asking again. I imported .SVG logo into blender to make it 3D. My idea was extrude different components and then drill the hole by boolean modifier. Obviously I must be missing something as the boolean draw only edges into other object, but did not make holes. Let see if you could see the issue from the following picture:  The edges I have selected are from bottom. Inside of those selection you can see the edges coming from boolean modifier. The same is on roof (not selected edges). Total different question is, why there were few vertexes outside of the object. There were not many <10. The edges to the vertexes are those few going down. Is there something I could change on this? At first I though this was because I forgot to fill all caps, but that (alt + f) did not solved the issue. ...or is there total different and better way of doing this.


Practical non-image based CAPTCHA approaches?

It looks like we'll be adding  support to Stack Overflow. This is necessary to prevent bots, spammers, and other malicious scripted activity. We only want human beings to post or edit things here!  We'll be using a JavaScript (jQuery) CAPTCHA as a first line of defense:    The advantage of this approach is that, for most people, the CAPTCHA won't ever be visible!  However, for people with JavaScript disabled, we still need a fallback and this is where it gets tricky.  I have written a  which we can re-use.    However, I'd prefer to go with something textual to avoid the overhead of creating all these images on the server with each request.  I've seen things like..   ASCII text captcha: \/\/(_)\/\/ math puzzles: what is 7 minus 3 times 2? trivia questions: what tastes better, a toad or a popsicle?   Maybe I'm just tilting at windmills here, but I'd like to have a less resource intensive, non-image based <noscript> compatible CAPTCHA if possible.  Ideas?


Indexes precision in large JavaScript arrays

I'm currently working on an algorithmic task with (relatively) big arrays and values in them. To be more specific, arrays have 100000 elements where all elements are integers and each element can be as high as 1000000000. So, the question is can JavaScript return wrong element on a given index or vice versa? I suppose so because as it revealed, it looses precision with integers multiplication and other operations after they grow higher than 10 to the power 18.


Does work done by a force change when initial velocity is different?

My understanding of work is that it is the product of a force and the displacement of the object in the direction of the force. So if an object is already moving at 1m/s and we apply a force of 1N in the same direction of motion, is the work done 1J after the object has moved 1m?  This seems wrong to me as it feels like the work done should be less than the case where the object starts with 0 velocity.


Can someone on xbox 360 play gta 5 online with someone on xbox one? They said its not possible for any game but thats a lie i played with a friend he has xbox one and i have 360.


"X times as many as" or "X times more than"

Suppose John has 5 sweets. Is there any difference between the following two sentences?     Jack has 3 times as many sweets as John.      Jack has 3 times more sweets than John.   I prefer the first construction and would know unambiguously that Jack has 15 sweets in this case. However in the second construction I would be inclined to think that Jack has 20 sweets, since it seems to suggest 15 sweets in addition to the original 5.


I have Ubuntu 12.04 LTS 64bit and from the beginning Skype is not working.  When I press the Video Call button starts a call and shows me a warning that has problem with Audio Playback.  I recently deleted Windows 7 and putted Ubuntu 12. 04 but I don't have Drivers for Ubuntu   .  When I press Call button nothing happened so I think that my problem is microphone recording problem. I have Compaq Presario CQ58 Series 100 and I cannot find drivers except the .exe for Windows


I have referred many links including the following:      -    I tried several ways to POST a new node to a Drupal site, but I have failed. I have created a sample CCK for storing students data with name, age, gender, DOB, and added some list.  I have installed and configured the Services module (D7), and created a service end point at services. As expected, GET is the easiest way to get details of a node in JSON. http://localhost/drupal/services/node simply listed all nodes.  I still can't figure out how to use the POST method.   I would like to search for the students whose name contains john. I tried localhost/drupal/services/node&node[name]=john. I used  POST Man plugin for Chrome without success. I also tried some other ways. I tried adding a new student to the site without success.   Can anyone guide me to make the above work fine?  UPDATE :  I tried adding new nodes of type article . It worked fine. but when i am trying to add nodes of type Department CCK It is showing "s:22:"CSRF validation failed";"  Here are the screen shots  I have gone through the link   I followed session = session_name=session_id but i still get an error.


modular arithmetic, solving $ax + b \equiv c \pmod d$?

For example $151x - 294\equiv 44\pmod 7 $. How would I go about solving that?  The answer says to simplify it into the $ax\equiv b\pmod c $ form first, but I have no clue on how to get rid of the $294$... help?


Uninstall Ubuntu 12.04 and reinstall windows 8

I bought an Hp computer a few weeks ago second hand and it has ubuntu 12.04 installed onto it. The guy i bought it off gave me the installation cd he used to put it on the computer but i really dont like it, i want to get windows back on the computer but have no idea how an earth to do that, i have a product key for windows 8 but no installation disk for it. HOW DO I REINSTALL WINDOWS AND UNINSTALL UBUNTU?????


I have a lot of difficulty understanding this proof we went over in class about classification of groups of order 12.  Let $G$ be a finite group of order $n=p^rm$ where $m \nshortmid p$.  Denote $Syl_p(G)$ as the set of all sylow p-subgroups, and $n_p(G)$ as the cardinality of $Syl_p(G)$.  (1) G has subgroups of order $p^r$. (How do we know this??)  (2) We know all sylow p-groups are conjugate and their number $n_p(G) | m$, by the 2nd and 3rd Sylow Theorems.  (3) We have that $n_p(G) \equiv 1(p). $  Then $n=12=2^2*3^1$ so $n_2(G)|3$ gives $n_2(G) \in \{1,3\}$ and $n_3(G)|4$ so $n_3(G) \in \{1,4\}$ since $2 \not\equiv 1(3)$.  Case 1: $n_3(G) = 4.$ Then the action of G by conjugation on $Syl_3(G)$ gives a homomorphism $f: G \rightarrow S_{Syl_3(G)} \simeq S_4$. $Ker(f)$ consists of $g \in G$ that normalizes all 3-Sylow subgroups. (Why?). Let $P_3$ be a 3-Sylow subgroup. Then the order of $P_3$ is 3. (I don't get that either), and $[G:N_G(P_3)] = 4.$ Thus $P_3 \subset N_G(P_3)$ gives $P_3 = N_G(P_3)$. (I'm lost here...) So $Ker(f) = \cap Syl_3(G) = \{e\}$ (the intersection of the sylow 3-subgroups is trivial. (How did we arrive here...) Thus we conclude that $G$ is isomorphic to a subgroup of $S_4$ of order 12.  To show $G$ is isomorphic to $A_4$, we have that $G$ has 8 elements of order 3: 4 3-sylow subgroups each has 3-1=2 elements of order 3. And $S_4$ has 8 3-cycles meaning f(G) contains all 3-cycles and hence the group they generate, which is $A_4$, so $A_4 \subset f(G)$. But since $|A_4| = 12 = |f(G)$ then $f(G) = A_4$ and $G \simeq A_4$. (Not understanding the first half of the proof, I do not get this part either).  Case 2: $n_3(G) = 1.$ The scope of the question is too large, I will need to post separately to understand the second half, unless the organizational rules of math.stackexchange would require that I post here. In that case, I'll edit the question.  I basically cannot follow the proof because it seems to skip too many steps; it would be helpful if anyone could elaborate case 1 with more reasoning so that I can follow it. Any help would be appreciated; I've spent hours trying to look up and decipher the proof but without any success.


Mail merge from Google Sheets to a Google Docs

I want to print out tests for a class I teach, but I want each to be identical except for the name of the student at the top. I want this to be drawn from a Google spreadsheet that I've created that has the first names listed in one column and surnames in the next.   How do I do this?


Can the speed of light in vacuum depend on the acceleration of the frame of reference?

In the general theory of relativity, the speed of light  in vacuum is $c$. In the special theory of relativity, a postulate is made that the speed of light is the same (called $c$) in all inertial frames. Consider the following statement: "The speed of light is $c$ in all inertial frames but it can vary in accelerating frames." My question is: Does this statement violate the principle of equivalence or the special theory of relativity or any fundamental law of physics?


If a car collides with an immovable, unbreakable wall, does energy lost or force determine damage?

$KE = \frac{1}{2}mv^2$ meaning the KE lost on impact would increase quadratically with speed, but f = ma would mean that force the wall applies to the car increases linearly with speed. So which really determines the damage to the car itself?


Story about two lovers who can stop time when they're touching - maybe in Omni

I think I read this story in Omni magazine in the '80s.  It's about two lovers who discover that whenever they're touching each other, time stops for everyone and everything else. Time just stands still outside of their bedroom - like hitting pause on a VCR.  I do remember one small detail: these two people tried to experiment with this ability, and they discovered that they could prepare meals, and that they would stay hot while time was paused. They experimented in other ways, too, though I cannot recall how.  Sometimes my searches turn up a story about two lovers who are time travelers - there is jealousy and some paradoxes - but the story I am thinking of is not a story about time travel, at least not directly.  I've tried googling for it, but the search terms (e.g. "lovers touch time stops") are so non-specific that all I get are false hits. I've tried looking here both using Search and Similar Questions. No joy.


Trying to install Ubuntu Server 20.04.01 - the Ethernet driver is not detected. The motherboard does not have onboard Wi-Fi. I have a USB Wi-Fi dongle available but not sure how to mount etc. and if its possible to use. Is there a way to get this machine going, either via the Wi-Fi dongle or potentially installing the onboard Ethernet driver via a USB drive after downloading from another machine? (Realtek RTL8125)


I just recently got into C++, and I wanted to make something simple to start off with. I made a console program that asks the user for a file path and then deletes the file. However, I've encountered a problem I cannot seem to resolve or find a solution for. The statement DeleteFile(filePath.c_str()); is giving me 2 errors:     argument of type "const char*" is incompatible with parameter of type "LPCWSTR"      'BOOL DeleteFileW(LPCWSTR)': cannot convert argument 1 from 'const_Elem*' to 'LPCWSTR'   First of all, I need to convert std::string to LPCWSTR, so I added c_str() in the end which gave me those 2 errors.  I'm still a noob in C++ so go easy on me.   #include <iostream> #include <string> #include <Windows.h> #include <fstream>  int main()  {     loop:     HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE);     std::string filePath;     SetConsoleTextAttribute(h,15);     std::cout << "\nEnter the path of the file you'd like to remove: ";      if (!std::getline(std::cin, filePath)) { std::cout << "I/O error!"; }      while (true)     {         if (!filePath.empty())         {             SetConsoleTextAttribute(h,15);             std::cout << "[+] Checking if file exists";             std::ifstream ifile(filePath);             if (ifile)              {                 std::cout << "\n[!] File exists!";                 std::cout << "\n[#] Deleting file";                 DeleteFile(filePath);                 std::ifstream ifile(filePath);                 if (!ifile)                  {                     std::cout << "\n[!] File deleted successfully!";                 }                 else                  {                     SetConsoleTextAttribute(h, FOREGROUND_RED | FOREGROUND_INTENSITY);                     std::cout << "\n[!] Failed to delete file";                 }                 goto loop;             }             else              {                 SetConsoleTextAttribute(h, FOREGROUND_RED | FOREGROUND_INTENSITY);                 std::cout << "\nPlease enter a valid file path!";                 goto loop;             }              break;         }         else         {             SetConsoleTextAttribute(h, FOREGROUND_RED | FOREGROUND_INTENSITY);             std::cout << "Please enter a valid file path!";             goto loop;         }     }     std::cout << "\nFile deleted!"; }


Problem: I can format it. But after formatting it will come back to it's previous condition. If I wanna access the SD card the PC and smartphone get slower. Sd card 8gb Used 1.96 gb.


I writing ASP.NET MVC web app.  I have webpage here is design of it    Here is DropdownListFor   Also I have model , here is code:   public class Companies {     [Key]     public int CompanyID { get; set; }        [Display (Name = "Компания")]     public string CompanyName { get; set; }   }   I need to display CompanyName in DropDownList CompanyName 's is in table (over 10)  I try to do it like this  @Html.DropDownListFor(m => m.Company,                  new SelectList(Enum.GetValues(typeof(Companie_s))),                  "Select Company")   But this right when I have enum and static values. Like this  public class Companies {     [Key]     public int CompanyID { get; set; }        [Display (Name = "Компания")]     public Companie_s CompanyName { get; set; }     public enum Companie_s     {         Ciklum,         Luxoft     }  }   How I need to write code in my case?  Thank's for help.


Looking to find the recommended resource specifications, CPU, RAM, Disk, for running internal DNS and Apple Remote Desktop Task Server within a Mac OS only environment on Mac OSX Server.  As we currently we do not have any "server" level hardware, i.e. Apple MacPro or Dell PowerEdge, my thought is to beef up a couple of older MacBook Pro 2012 models until Apple releases new hardware.  To run an OSX DNS server, for internal/split DNS, on a network with approximately 2,000 clients, what would be necessary amount of RAM? Is 8GB sufficient or do we need more like 16GB? (MBP supports up to 32GB)  Right now all DNS points to an external provider (OpenDNS or Google) and all external traffic would continue to be forwarded.  Same question for the ARD (Apple Remote Desktop Task Server). Is there a sweet spot for the amount of RAM required? We do not plan to do major deployments of packages at this time, but use it in conjunction with the DNS server to manage lists of internal devices for remote connection.


Suppose that the second fundamental form of a surface patch $\sigma$ is zero everywhere.   How can we prove that $\sigma$ is an open subset of a plane?   The second fundamental form of a surface patch $\sigma$ is $$Ldu^2+2Mdudv+Ndv^2$$ where $L=\sigma_{uu}\cdot \textbf{N}, \ M=\sigma_{uv}\cdot \textbf{N}, \ N=\sigma_{vv}\cdot \textbf{N}$.   What does it mean that the second fundamental form of a surface patch $\sigma$ is zero everywhere? That $L=M=N=0$ ?   $$$$   EDIT:   We have that $\sigma_u\times\sigma_v$ is perpendicular to both $\sigma_u$ and $\sigma_v$.  So $N=\frac{\sigma_u\times \sigma_v}{\|\sigma_u\times\sigma_v\|}$ is perpendicular to both $\sigma_u$ and $\sigma_v$.  Therefore, $ \sigma_u \cdot N=0$ and $\sigma_v\cdot N=0$.   We also have that $$\sigma_{uu}\cdot N=0, \sigma_{uv}\cdot N=0, \sigma_{vv}\cdot N=0$$   So, $$( \sigma_u\cdot N)_u=0 \Rightarrow \sigma_{uu}\cdot N+\sigma_u \cdot N_u=0 \Rightarrow \sigma_u \cdot N_u=0$$  $$( \sigma_u\cdot N)_v=0 \Rightarrow \sigma_{uv}\cdot N+\sigma_u \cdot N_v=0 \Rightarrow \sigma_u \cdot N_v=0$$  $$( \sigma_v\cdot N)_u=0 \Rightarrow \sigma_{vu}\cdot N+\sigma_v \cdot N_u=0 \Rightarrow \sigma_v \cdot N_u=0$$  $$( \sigma_v\cdot N)_v=0 \Rightarrow \sigma_{vv}\cdot N+\sigma_v \cdot N_v=0 \Rightarrow \sigma_v \cdot N_v=0$$   So, $N_u$ and $N_v$ are perpendicular to $\sigma_u$ and $\sigma_v$.  We have that $N_u$ and $N_v$ are perpendicular to $N$. $N$ is perpendicular to the tangent plane. So, this implies that $N_u$ and $N_v$ lie in the tangent plane of the surface, which is spanned by $\sigma_u$ and $\sigma_v$.   We have that $N_u$ lies in the tangent plane that is spanned by $\sigma_u$ and $\sigma_v$, and that $\sigma_u\cdot N_u=0$ and $ \sigma_v\cdot N_u=0$, which means that $N_u$ is perpendicular to $\sigma_u$ and $\sigma_v$.  This can only hold when $N_u=0$.  Respectively, we get $N_v=0$.  Is this correct?   Since $N_u=N_v=0$, we conclude that $N$ is constant.   Since $N$ is perpendicular to the tangent plane, we have that $\sigma_u \cdot N=\sigma_v\cdot N=0$. So,   $(\sigma\cdot N)_u =\sigma_u\cdot N=0$   $(\sigma\cdot N)_v =\sigma_v\cdot N=0$   So, we have that $\sigma\cdot N=c$, where $c$ is a constant.   How co we conclude from here that $\sigma$ is an open subset of a plane?


I just had nothing to do and started messing around with for loops in Java, so I wrote the following function  static int getCurrentTime() {     return (int)System.currentTimeMillis(); }   which simply gets the time for me.  Now I have my main function:  public static void main(String[] args) {     int s = 0;     int beginTime = getCurrentTime();     for (int j = 0; j < 2000000000; ++j)         for (int i = 0; i < ####; ++i)             s++;      System.out.println("done in " + (getCurrentTime() - beginTime)+                        " milliseconds!"); }   Now when I put 1 in the place of ####, I get the following output  done in 4118 milliseconds!   But when I put 3 in the place of ####, I get the following output  done in 11 milliseconds!   How is this possible? How did more iterations take less time? I'm really confused about what's happening here.


When soliciting donations on a website, should you start by providing a box for the donation amount?

A coworker forwarded me some feedback she had come across during an annual giving network discussion regarding website design for online giving websites:     I'm jealous of this  even better is their main page  which features not a click to give button, but rather, a box to start writing in the amount of your gift!    On our own website, we have a prominent "Donate" button that brings users to a form, which starts with an introduction about what the donation will be used for.  Additional fields on the form make it clear to the donor the level of control they have over what the donations would be earmarked for.  I'm concerned that if we implemented a system where the dollar amount was the first thing entered, before any context would be given, that no matter how convenient it seemed, it might discourage potential donors.  It would also seem to eliminate the possibility of upselling to a larger donation amount, if the first step is to put the amount of the donation.  Is it better to start with a dollar amount, or provide more context for the donation before asking for a specific amount?  Will one strategy yield a higher conversion rate, or potentially a higher donation amount?   If it is relevant, our donor demographic is generally affluent senior citizens, with very few of our donors being under the age of 50.


Show the existence of a complex differentiable function defined outside $|z|=4$ with derivative $\frac{z}{(z-1)(z-2)(z-3)}$

My attempt  I wrote the given function as a sum of rational functions (via partial fraction decomposition), namely  $$ \frac{z}{(z-1)(z-2)(z-3)} = \frac{1/2}{z-1} + \frac{-2}{z-2} + \frac{3/2}{z-3}. $$  This then allows me to formally integrate the function. In particular,  I find that  $$ F(z) = 1/2 \log(z-1) - 2 \log(z-2) + 3/2 \log(z-3) $$ is a complex differentiable function on the set $\Omega = \{z \in \mathbb{C}: |z| > 4\}$ with the derivative we want.  So this seems  to answer the question, as far as I can tell.   The question then asks if there is a complex differentiable function on $\Omega$ whose derivative is  $$ \frac{z^2}{(z-1)(z-2)(z-3)}. $$ Again, I can write this as a sum of rational functions and formally integrate to obtain the desired function on $\Omega$ with this particular derivative. Woo hoo.  My question  Is there more to this question that I'm not seeing? I was also able to write the first given derivative as a geometric series and show that this series converged for all $|z| > 3$, but I don't believe this helps me to say anything about the complex integral of this function.  In the case that it does, perhaps this is  an alternative avenue to head down?  Any insight/confirmation that I'm not overlooking something significant would be much appreciated.  Note that this an old question  that often appears on study guides for complex analysis comps (one being my own), so that's in part why I'm thinking (hoping?) there may be something deeper here. For possible historical context, the question seems to date back to 1978 (see number 7 here):   Thanks for your time.