Well, I was wondering about the real age of our universe, I found that it's estimated to be $13.8\times 10^9$ years.  Is it an approximation, or laws behind this age?
Many times I have read statements like, "the age of the universe is 14 billion years" . For example this wikipedia page .   Now, my question is, which observers' are these time intervals? According to whom 14 billion years?
Is there a limit as to how fast a black hole can grow? Screen Resolution Problem with Ubuntu 14.04 and VirtualBox Environment: Lenovo T530 running Windows 7.  Have installed Ubuntu 14.04 on a virtual machine using VM Virtual Box.  Have installed all the updates from both Virtual Box and Ubuntu.  Problem: While in Ubuntu's desktop and other Ubuntu initiated programs, the window is reduced to about 3x4 inches showing in the middle of the rest of my regular Virtual Box window.  I am seeing only the upper right hand of the screen output of what I would normally see.  Please help.   I've seen    But, none of these answers works in 14.04. Is it possible to extend a tourist Schengen visa (12 more days)? How to change color for a block of texts? DMed for the first time yesterday and one of the things I feel I need to sort out, among other comments, improvements, and similar, is how combat itself is actually initiated. The main example I want to use involves  attempting to generate surprise conditions by players. Here the characters have entered a ruined city and generally been noisy about the whole thing - using a spell to make their voice louder and literally ask if there is anyone about. Any enemies around probably know what something is about to kick off but arguably don't know precisely what. After resting the PCs head up a long flight of steps to a temple on the edge of the city. At the top only one crests and finds 3 bandits lounging around, chatting, and doing whatever bandits do in their spare time. After a brief exchange of pleasantries a combat starts:  DM &quot;The bandit spits in your direction 'we're not done looting the temple, so you can clear off', and starts raising his crossbow as his mates emerge from their cover behind the pillars... PC &quot;I cast Firebolt at Bandit Keith&quot; DM &quot;Hang on, I hadn't finished, everyone rolls for initiative...  Which sparked a debate about whether or not the PC could preemptively cast/attack before the combat starts by &quot;instant actioning&quot; (as above) as I was describing the start of the combat. As far as the bandits are concerned a lone half-elf who is pretty heavily armed has popped up in front of them, not even tried to be diplomatic, and ended up saying something rather suggestive about their mothers. The PC then asked about it being &quot;surprise&quot; because the bandits wouldn't necessarily expect an attack, but my view of &quot;surprise&quot; is closer to an ambush where one party is unaware of the other's existence. (This precise example is close to how  works, however this specific PC was always the first of the party to go into rooms (only one with darkvision) and consistently felt they should get free rounds at the start of combat based on declaring attacks before I could &quot;start&quot; the combat.) The second example the party came to more bandits, who were not alert immediately, in an underground room. They used magic to yell something obscene at the bandits and shut off all the torches so the bandits were effectively blinded. At this point they wanted to burst into the room casting spells, swinging maces, and playing some &quot;meaty chords&quot; (the bard's words, not mine). Again they wanted surprise arguing that, despite the fact that the bandits were yelling and cursing in confusion, they couldn't be sure they were actually being attacked as such. In the end a character with darkvision wanted to sneak in to a corner and again wanted surprise based on passing stealth rolls, so they would start the &quot;combat&quot; by firing a crossbow. At that point I think I relented because it was clear that they would do anything to try and win combats in a single round. In a nutshell, my question is: &quot;how liberally can the concept of surprise be applied to combat - is it only when one party is literally unaware of a threat (as I read the rules), or just when they are caught slightly off guard by the exact situation?&quot; NB I already plan to address the attempts at interrupting descriptions with actions next session, because it happened at other times and actually threw me off quite a bit. Do flight attendants prefer I press the button or walk to the back? (Long-haul flights) Deny access to a webpage using web.config I'm a European citizen living in the US on a work visa. Due to some unfortunate circumstances, I need to urgently visit my home country. However I would like to get back to the US after my visit is complete. Flying from the US to Europe is not a problem as there are still daily flights between some city pairs. However going back could be tricky, as  anyone who has been in the Schengen area in the past 14 days from re-entering the country.   Is there a flight route that would let me from Europe to some country, stay there for 14 days and then fly to the US? Canada is out, as they've banned international visitors. Mexico seems to keep their border open, but I  any direct European flights from their airports. Almost every other country either suspended flights or doesn't allow foreign nationals to enter. Why are the two versions of Chromium and VLC available in Ubuntu software of different sizes? Is Morocco currently safe to visit despite the Ebola outbreak? I'm travelling to Morocco over the Easter period, and while I am aware that the current Ebola outbreak is mainly in Guinea, Liberia and Mali, and would have to cross the Sahara to get to Morocco, is it wise for me to go to Morocco at this time?  What are some basic precautions I can take in the case that the Ebola virus travels to Morocco? I would like to set up memoir so that when I use \footnote{foo}, foo is displayed in the margin with the proper label and preferably break over pages.  There is an option \footnotesinmargin which gives almost exactly what I need, only justified. I want it to use ragged2e and change alignment based on even/odd page so that the margin note is always flushed towards the main text area and allows hyphenation on the side of the edge.  \documentclass[12pt, draft]{memoir} \footnotesinmargin \usepackage{polyglossia} \setmainlanguage{english} \usepackage{fontspec} \defaultfontfeatures{Ligatures=TeX} \setmainfont[Ligatures=TeX,Numbers=OldStyle]{Minion Pro} \usepackage{kantlipsum}  \begin{document} \kant[1]\footnote{\kant[1]} \kant[2]\footnote{\kant[2]} \kant[3-5] \end{document}   Possible partial work-around  I have remembered a nice thesis based upon the Classic thesis template and found the  which indeed contains a possible solution:  \usepackage{marginnote} \usepackage{ragged2e} \newcommand{\sidemark}[1]{#1.{\:}}  \newcommand{\marginelement}[2][0]{%   \marginnote{%     \strictpagechecktrue     \checkoddpage     \ifoddpage%       \RaggedRight\footnotesize%     \else%       \RaggedLeft\footnotesize%     \fi%     #2%   }[#1\onelineskip]% }%  \newcommand{\sidenote}[2][0]{%   \footnotemark%   \ignorespaces%   \marginelement[#1]{%     \sidemark{\thefootnote}%     \ignorespaces#2%   }%   \unskip% }%   Nevertheless, I would still prefer a memoir-specific solution with the re-definition of footnotes when used with the option \footnotesinmargin mainly for the sake of portability. This work-around also does not work with hyperref (there is no hypertext connection) and does not break over pages automatically. What is the name of the depiction of concentration with raised eyebrow called? Why are most of the main characters White/English in Game Of Thrones? With no good reason I had a look at my computer's storage going on the apple and About this Mac. Here is the display:    The pink bar doesn't make much sense. It obviously does not represent the 80.67GB of free storage. Two sections correspond to pink; "Photos" and "Backups". I obviously don't have 140.76TB of backups. And probably not on this computer that has only 320GB of storage.  What is going on here? How do I recover lost/inaccessible data from my storage device? What steps can I take to try to recover lost or inaccessible data from any storage device?  Answers:   This applies to any computer storage device, e.g. internal/external hard drives, USB sticks, flash memory. The most important thing is to STOP using it, any type of I/O can ruin your chances of a recovery.     We have separate questions covering common problems with USB flash drives in greater detail: Is Stack Overflow merging two different accounts by email without the user's consent? I had one account through Google with email X and another account through myopenid.com. I happened to add the same email X to this myopenid.com account. My intention was to stop using the Google account in favor of the new myopenid.com account.   After some time asking and answering questions with my openid.com account I am astonished to find out that it is now merged into my Google account. That creates all kinds of privacy issues. I thought the email on my Stack Overflow account was private. Did I miss anything here?  To be clear, I wanted to preserve my privacy in the second account, but now since all my recent questions were transferred to the old account, my privacy is completely lost.  And it looks like there is no verification for the email field in my profile, so if Stack Overflow is using that info to merge, there is a very serious security bug. If it is merging based on something else, that's even worse. I think your account belongs to that user here. Let me merge it. Terrible! Is there a way to delete all stack exchange accounts at the same time?  I also want to remove all traces of my posts on the site. Is that possible?   Will I have to delete all of my posts manually?  Can I use the stack exchange API for this? How can I work around this TikZ bug: (\x)^2 and \x^2 produce different results in TikZ plot? PSTricks will not compile \documentclass[12pt]{article} \usepackage[paperheight=9in,paperwidth=13.24in,margin=0in]{geometry} \usepackage{pstricks} \usepackage{graphicx} \begin{document} \thispagestyle{empty} \psset{unit=1in} \begin{pspicture}(13.24in,9in) \psframe[fillstyle=solid,fillcolor=Maroon](0,0)(13.24,9)  \end{pspicture}  \end{document}   I am following a tutorial outlined here:   I am following the Robbers book.  Everything seems fine until I paste the \psframe[fillstyle=solid,fillcolor=Maroon](0,0)(13.24,9)  What could be the problem? Showing $F[x,y]/(ax^2+by^2-1)$ is a Dedekind domain