While doing science homework, I came across something I found strange. The term "eukaryotic" had a as the article instead of an. I was looking at:     A eukaryotic cell...   I learned that if a word started with a vowel, it should be an instead of a. My bio textbook says otherwise.   Why is this?
Which indefinite article should precede hour — a or an?        an hour     a hour      Does the usage of an vs a depend on the pronunciation — a history, a hobby, but an hour, an honor?
Is it time to be rid of automatic down votes on certain closed questions? How can I get the current working directory? I want to have a script that takes the current working directory to a variable. The section that needs the directory is like this dir = pwd. It just prints pwd how do I get the current working directory into a variable? How old is too old for a PhD? Are there any age limits (formal, informal, or guidelines) that schools use when deciding to accept someone into a PhD program? I'm most curious about the upper age limits. For example, will most schools accept someone in their 40's? How about their 50's? How do I install drivers for Realtek RTL8812BU? So I've been experimenting with Ubuntu on and off for a while, but I honestly have no idea what the hell I'm doing. So I have a realtek RTL8812bu WiFi dongle that I'm hoping to get working. I did some research, and came across  that a couple people across two threads said worked for them:  At the bottom it said there is a new version . So somewhere it said it was confirmed to work on kernels up to 4.16, so I checked and I'm on 4.15.0. But the problem I'm having, is what am I supposed to do? There is some installation guide at the bottom that is about as clear as mud to me since I don't know much. Too much space between links in post menu Show uncountable set of real numbers has a point of accumulation Show that every uncountable set of real numbers has a point of accumulation. Tachyons and Photons Is there a particle called a "tachyon" that can travel faster than light?  If so, would Einstein's relativity be wrong?  According to Einstein no particle can travel faster than light. Why can two (or more) electric field lines never cross? Does slowing light violate relativity? how to left justify comments to indent same as other text in Algorithmic How do I left justify my comments in the algorithm.  I am using algorithmicx package.  What I want is: to pull the comment to left as shown in the attached snapshot.  The code for my algorithm is       \documentclass[a4paper]{article}     \pagestyle{empty}     \usepackage{algorithm}     \usepackage{algpseudocode}     \usepackage[caption=false,font=footnotesize]{subfig}     \begin{document}     \begin{algorithm} \label{algoQ}     \caption{Algorithm to check quality of methods}     \begin{algorithmic}     \For{\textbf{each} $msd$ in$msdList$}  \Comment { \% for each MSD \%}     \Statex   \Comment { \% get MSDs referenced method service \%}     \EndFor \textbf{endFor}     \end{algorithmic}     \end{algorithm}     \end{document} Man/Tree Symbiosis It was an old book... I'm pretty sure it was a book, and pre-1990's I think. The basic plot was this man somehow interacted with this tree, and as a result he became a carrier of the tree's 'seed'. They were in a symbiotic relationship: the man got a much longer life, more strength, etc.; but when he did die the tree would grow up from his body. is a wonderful freeware Windows swiss-army-knife for image viewing &amp; editing.  For me, the key features are fast viewing, simple editing (crop, contrast, brigthness, rotation, resampling), file operations (delete, copy to folder) and extended image information access (exif data) combined in the same interface. Versatile batch jobs are a very nice bonus.  But unfortunately IrfanView is for Windows only, and isn't . What would be the nearest equivalent for linux? Determinant of an $n\times n$ complex matrix as an $2n\times 2n$ real determinant If $A$ is an $n\times n$ complex matrix. Is it possible to write $\vert \det A\vert^2$ as a $2n\times 2n$ matrix with blocks containing the real and imaginary parts of $A$?  I remember seeing such a formula, but can not remember where. Any details, (and possibly references) for such a result would be greatly appreciated. Antecedent Precedence? Evaluating $\int_{0}^{\infty}\frac{\sin^{2n+1}x}{x}\mathrm{d}x$ What are the regulations for transporting medication abroad? This is in reference to medications, both prescription and non-prescription, not illicit drugs. Since the legality may vary on country, let's say a round trip from the US to Singapore, as an example.  When travelling with prescription medication, I am aware that you are supposed to bring your prescription with you. What about over-the-counter medication, such as Tylenol/aspirin? How about medication which is restricted or prescription-only in one country, yet available OTC in another (think Viagra)? Yesterday, I was browsing the mobile Stack Overflow site. I noticed one thing: the textareas where you write your comments/answers are very buggy. I'm using a Samsung Galaxy S2, with the standard Android browser (Android version 4.1.2). There are a number of things that aren't working when typing your comment/answer.   Automatic spacing with Swype is disabled (however this might be because of Swype, not the site). Text navigation buttons (step left, step right, select text, copy text etc.) doesn't work with the on-screen keyboard, and selecting text by holding your finger over text is extremely difficult. When you paste something it always seems to be pasted at the top of your text, no matter where you try to paste it. Replying to another comment ("@Example User") does not show suggested people to reply to, like the full site does.   Is there anything I can do to solve these issues/bugs, or is it in the hands of Stack Overflow itself, and if so, should it be looked into?  Edit: I was using the mobile version of the site when noticing these bugs. I get      every few minutes on Kubuntu (KDE), and the panels disappear.  It restarts itself automatically, so it's not a real problem, just an annoyance, but it is a big annoyance.  I've tried sudo apt install --reinstall plasmashell plasma-desktop, but that made no difference.  When I try a backtrace from the error message, it says it's unable to produce a useful backtrace. In "Tasksel" how do I select a package? I found a video on YouTube that shows someone using the command tasksel from the server's boot menu after a fresh install of Ubuntu Server. Simple enough it looked like, but when I go to the options I want to choose for installation it has no information on how to select them, and when I click Enter on one of them it takes me back to the command prompt.  So how do I make a selection of the items listed under tasksel?  I have tried Shift++ to add, but no luck. Anyone know?  I want to install Ubuntu Desktop, as Ubuntu GNOME GUI is not an option in the listing for Ubuntu 17.10 Server. Some questions are getting closed as duplicates - good, the system is working. Unfortunately, some are getting closed as duplicates of other questions which are already deleted. This leaves all 1-9,999 reputation users left scratching their heads when they try to view the duplicate. Even worse, imagine being the author of the question and having your question closed as a duplicate when the original question isn't accessible.  I think something is wrong. Today I undeleted a question (left it closed) since it was referenced in the close-reason for another question. Comments indicated that people were clearly irritated that they could not access the duplicate     [Comment] Ok, who thought it was a good idea to close this as duplicate of a deleted question, which most people cannot even see? For the record, I'm reopening - clearly there's enough interest in this question. – Kobi 14 hours ago   ---   [Comment] The PosibleDuplicate link is broken. Voting to reopen. – Rahul G 7 hours ago   ---   [Flag] Closed as duplicate of a deleted question, fail. Thanks for moderating. – {username removed} 14 hours ago   My undelete-action was short-lived, as a few users returned to delete the post again.  It certainly cannot be desirable to reference posts that the vast majority of users cannot even see, especially when the author of the redundant question cannot see (at the time of writing this, the author has a reputation of 18).  I'm not sure what the solution is to this, but I'd like to hear some ideas.  Questions  Question:  Duplicate of: