Does the electron have size?
Do electrons have shape?
Accepted answer appearing below top voted Using 3rd party Python modules I'm currently developing a script for Blender to handle Mesh Frequency Decomposition.  The script is nearly complete, but i need one more thing: The SciPy library to compute eigenvalues and eigenvectors.  Following the installation instructions on , I'm able to install it as well as Numpy. Numpy works fine, but I can't even import SciPy:  Traceback (most recent call last): File "/CAF_FD.py", line 4, in &lt;module&gt; ImportError: No module named 'scipy' Error: Python script fail, look in the console for now...   By the way, I'm working on Linux 64 bit and I've installed SciPy and Numpy with my package manager.  Edit: When I try to use SciPy with a terminal prompt, it works. An "urgent" tag for questions that need answers within minutes Indecomposable limit ordinals Why Multiplication of zero by any number is zero? If I multiply $a$ by $0$, it means $a$ is added $0$ times, but I am not able to visualize $0$ times! Should edits with only minor code improvements be accepted. As an example, I'm reviewing an edit that changes all double quotes to single quotes and renames a variable in some javascript. With the exception of the variable rename (which is not entirely necessary), the edit is frivolous. Should I accept on the merits of a debatable variable name change? How do "and" and "or" act with non-boolean values? Is sudo required for installing VMware Tools? I'm trying to install VMware Tools in Ubuntu 16.04. Should I do this by using sudo? Why? What's wrong with var x = new Array(); Please tell me which choice below (or rather a better choice that I need to know) works better in my sentences in informal English:     I got myself out on a limb. I need to clear my check by tomorrow. No matter how, I must ............ 2 million bucks by tomorrow.   a) line up [to prepare, organize, or arrange something]  b) hook up [hook somebody up with something to help someone get something that they need or want]  c) fix up [to arrange for someone to have something that they need]  For me, all three options work in this sense with the same meaning and informality degree. Present-perfect-tense vs. Simple-past-tense Sort Order on Close Vote Queue The Close-Vote queue is large and growing. I searched for definitive information on how that queue is sorted for reviewers, and the nearest I could find is that it is randomized - but that post was some years old.  Would it be possible to sort on order of votes already received? That is, all questions with 4 votes to close are surfaced first (in random order) to reviewers? Questions with 3 votes would come up before ones with 2, etc. In that manner a given question gets out of 'will it close?' limbo faster.   This feature request would, in my opinion, be supportable if the majority of reviewer votes were going to single-vote questions. I cannot (I think) actually find these numbers. If this is the case, the majority of the work is going to an ever-increasing queue, and proportionally fewer votes are being resolved.  Note there are other distributions that could help get in this direction without being a strict ordering, like weighting the chance a given question is surfaced to a reviewer by the number of votes. However, for discussion purposes I thought I'd keep it simple.  Usual apology if this has actually been addressed. Search is sad-making. What is the relationship between regression and linear discriminant analysis (LDA)? Is there a relationship between regression and linear discriminant analysis (LDA)? What are their similarities and differences? Does it make any difference if there are two classes or more than two classes? How can I get to Iceland on a cargo ship? Planning a low budget and environment friendly trip to Iceland from Helsinki, Finland next summer for me and my friend. Haven't been able to find relevant information on possibility for cargo travel (from where - eg. Norway, Denmark? - timetables, prices etc). Expected departure from Helsinki around June 18th, return at latest on July 7th 2015. I'm very thankful for any related advice (and first time on stackexchange, so apologies if I didn't formulate my question in a best possible way) Undefined control sequence \documentclass First of all I would like to thank you because you helped me out a lot with all your answers to the already online questions.  Now, here is my problem. I am trying to do a bibliography file with TeXworks but I get this error when I try to compile (pdfLaTeX+MakeIndex+bibTeX):      This is pdfTeX, Version 3.1415926-2.4-1.40.13 (MiKTeX 2.9 64-bit)     entering extended mode     ****PATH here******     ! Undefined control sequence.     l.1 \documentclass         [a4paper,11pt]{report}   I've been reading some similar questions but I don't find the way to fix it (maybe I am missing something). I found one that says that I am trying to compile a LaTeX file using TeX compiler but I don't know how to change the configuration.  This is the .bib fiel content:      \documentclass[a4paper,11pt]{report}     \usepackage[english]{babel}     % faire de l'anglais     \usepackage[latin1]{inputenc}   % accents dans le source     \usepackage[T1]{fontenc}        % accents dans le DVI     \usepackage{url}     \begin{document}      @Article{ref11, author={Danihelka, Jiri and Kencl, Lukas}, journal={Cloud Futures Workshop 2012 }, title={Colaborative 3D Environments over Windows Azure}, year={2012}, month={May}, pages={}, note={}     }      @book{ref12, author = {Lee, Henry and Chuvyrov, Eugene},     title = {Beginning Windows Phone 7 Development},     publisher = {Apress},     volume = {},     number = {},     series = {},     address = {},     edition = {Second edition},     year = {2011},     month = {July},     note = {}     }      @Article{ref13, author={}, journal={}, title={Cloud computing}, year={}, month={}, pages={}, url={\url{http://en.wikipedia.org/wiki/Cloud_computing}}     }      \end{document} How to get a vertical bar which is longer than \mid ? sometimes when writing mathematical expression with partial derivatives, one needs to write a vertical bar afterwards and write the value at the which the partial derivatives are being computed as subscripts. See for example the bottom post here:    However, the \mid symbol doesn't produce a tall bar that corresponds to the size of the partial derivatives term. Is there a way to have a taller bar?   PS: Some other posts here mention \middle| but this doesn't compile on my computer.  Thanks in advance.... Hide page numbering but retain header/footer I would like to remove page numbering on a specific page. However, the header and footer should remain intact. If I try:  \thispagestyle{empty}   The header and footer disappear. What is the recommended way of removing just the page number? Are submodules of finitely generated free modules always free? I don't believe it's true that all submodules of a finitely generated free module are free just based on results from google. Is there a canonical simple example of a finitely generated free module with a submodule that is not free? I'm using the built in Screen Sharing tool in El Capitan to control an iMac from a Macbook Pro in full screen mode. Everything works beautifully except that many special keys and gestures are intercepted by the local Mac and not sent to the shared Mac. Specifically:   Ctrl-Arrow (Desktops and Mission Control) F3 (Mission Control) F4 (LaunchPad) Three finger swipe (Switch between Desktops, Mission Control, Exposé) Two finger swipe from left side (Notification Center) Pinch with four fingers (Launchpad)   I can't find any way to switch between desktops on the remote machine other than manually opening the Mission Control app from the Finder or Dock. Disabling the gestures on the local machine doesn't help; they still don't get sent to the remote machine.  Is there any way to get special keys and gestures passed to the shared machine? Is there a picture showing all the lengths used in lists?