I was recently sold an iPad by someone on the net. We met to do the exchange. When I tried to set up, she couldn't remember the ID or the password. Now I can't get hold of her and am stuck with an iPad that doesn't function. What can I do?
I bought a used iPhone 4.  The previous owner re-set the phone, but did not remove the device from their iCloud.  It is asking me for their iCloud information when I try to set-up the phone.  I don't have contact with the previous owner anymore.  Is there a way to remove the device from their iCloud so I can use a new one?
I'm in the following situation: In 3 months, I'll finish my PhD in theoretical physics, and I'm certain that I want to pursue an academic career. However, I'm just as certain that my PhD research is a dead end. (My advisor doesn't think so, but I disagree with him.) Thus, I seek to change the direction of my research, but I need a few months to obtain the necessary skills. Anyway, I missed the main application period for post-doc positions (in the US).  Given the following options (feel free to expand this list), which do you think provides the best perspective of leading me to a interesting post-doc position?   Finish my PhD. Get any post-doc position. Do the work I'm required to do there. Work hard in my spare time to teach myself the stuff I want to. After 1-2 years, find a post-doc position I'm really interested in. Finish my PhD. Get a well-paying job in the software industry. Do the work I'm required to do there. Work hard in my spare time to teach myself the stuff I want to. Work harder to keep publishing papers. After one year, find a post-doc position I'm really interested in. Abort my current work. Find a new subject and a new PhD advisor. Live on unemployment money as long as possible. Work hard in my spare time to teach myself the stuff I want to. Work harder to keep publishing papers. After one year, find a post-doc position I'm really interested in.   Pros:   Get the PhD title sooner. Stay in the scientific community. Get the PhD title sooner. Earn lots of money (6 figure). In a 9-to-5 job, have more spare time for private research than on a post-doc position, where work is never finished. Go to a foreign country. It's what I should've done 2 years ago. I'll have the education I want when I finish my PhD, not later (but be older anyway). No immediate advantages over the other options.   Cons:   If a logical continuation of my PhD work, I'll suffer from demotivation. My next advisor will not want me to work on other topics that I'm not paid for. Might have to stay for 2 years. I'll move out of the scientific community for some time. I know it's hard to get back in. I'll be even older when I finally get my PhD. Not sure if I would find another advisor. Open fight with my current advisor. I don't want to live on unemployment money for long.   A particular question concerning the options above: Does being out of academia for a year kill your prospects of obtaining a postdoc position later?  I do have some collaborators who will help me to keep publishing, provided that I put enough work into my research. Also, I'm willing to familiarize myself with other topics on my own (a prerequisite for an academic career anyway).  The next application period will be from October to December 2013, which isn't far away. I'm sure I'll have most of the skills I want by then (and a paper published proving that), but still would have to work until summer 2014 wherever I am applying now.  Please give me honest answers, even if they hurt. I'll provide more information as soon as possible, if anyone has questions. Removing all fraction symbols like “¼” and “½” from a string Am I being scammed by a sugar daddy? Gparted: move extended partition on the left Maximum and minimum distance of two points Consider six distinct points in a plane. Let $m$ and $M$ denote respectively the minimum and the maximum distance between any pair of points.  Show that $M/m \geqslant \sqrt{3}$. Sign of determinant when using $det A^\top A$ We have been given matrix: $$A =          \begin{pmatrix}         a&amp; b&amp; c &amp;d \\         b &amp;−a&amp; d&amp; −c\\         c&amp; −d &amp;−a&amp; b \\         d &amp;c&amp; −b&amp; −a\\         \end{pmatrix}     $$ ...and have been asked to calculate $\det(A)$ using $AA^T$.  We see that:  $$AA^T=\begin{pmatrix}         a^2+ b^2+ c^2+ d^2&amp; 0&amp; 0&amp;0\\         0 &amp;a^2+ b^2+ c^2+ d^2&amp; 0&amp; 0\\         0&amp; 0 &amp;a^2+ b^2+ c^2+ d^2&amp; b \\        0 &amp;0&amp; 0&amp; a^2+ b^2+ c^2+ d^2\\         \end{pmatrix}     $$   So, $\det(AA^T)= (a^2+ b^2+ c^2+ d^2)^4$  Now which should I choose: $(a^2+ b^2+ c^2+ d^2)^2 $ or $ -(a^2+ b^2+ c^2+ d^2)^2$ ?  Please explain me which one and why. How to evaluate $\int_{0}^{\pi }\theta \ln\tan\frac{\theta }{2} \, \mathrm{d}\theta$ Why more (and varying number of) logical reads with read ahead (prefetch)? After creating tpch database in my SQL Server, I tried below query:      set statistics io on     DBCC DROPCLEANBUFFERS;             select top 100 * from dbo.lineitem order by l_partkey;   The table lineitem has a non-clustered index on l_partkey. I issued the above queries for several times and found out that the logical reads vary each time:      Table 'lineitem'. Scan count 1, logical reads 1019, physical reads 4, read-ahead reads 1760, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.     Table 'lineitem'. Scan count 1, logical reads 1007, physical reads 4, read-ahead reads 1720, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.     Table 'lineitem'. Scan count 1, logical reads 1030, physical reads 4, read-ahead reads 1792, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.   From the post here: , I know it could be caused by read ahead behavior.  BUT exactly why read ahead could cause more logical reads? How does it change the SQL Server behavior? Like SQL Server may read more index page since it's in cache anyway?  Anyway, I disabled read ahead and issue the above query again. Now it reports the same amount of logical reads each time. BUT the logical reads is much smaller!!      Table 'lineitem'. Scan count 1, logical reads 404, physical reads 160, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.   So my question is, why the read ahead feature could cause many more and various logical reads count?  Out of curiosity, I tried another query without the "order by":      select top 100 * from dbo.lineitem   Here's the result without read ahead:      Table 'lineitem'. Scan count 1, logical reads 5, physical reads 3, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.   Here's the result with read ahead:      Table 'lineitem'. Scan count 1, logical reads 15, physical reads 2, read-ahead reads 3416, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.   The one with read ahead still has more logical reads. So, why? Getting absolute path of a file I cannot update my Kali Linux, when trying to execute apt-get update I get this error message:  # apt-get update  Get:1 http://kali.mirror.garr.it/mirrors/kali kali-rolling InRelease [30.5 kB] Err:1 http://kali.mirror.garr.it/mirrors/kali kali-rolling InRelease   The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository &lt;devel@kali.org&gt; Reading package lists... Done W: GPG error: http://kali.mirror.garr.it/mirrors/kali kali-rolling InRelease: The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository &lt;devel@kali.org&gt; E: The repository 'http://kali.mirror.garr.it/mirrors/kali kali-rolling InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   If you need my kernel version:  # uname -a 4.13.0-kali1-amd64 #1 SMP Debian 4.13.10-1kali2 (2017-11-08) x86_64 GNU/Linux   How can I fix this? Why do we need virtual functions in C++? How can I change the language of the QGIS Interface? I want the QGIS interface in English, in order to share information with the GIS community. Using another language, when chatting with the GIS community, makes things more difficult. When I installed QGIS, it automatically set the language to French. It's very frustrating not having the opportunity to select my preferred language.   I am using Windows XP in French, but I want QGIS in English. Your Mileage May Vary In the United States we have a saying, "your mileage may vary", which means "your experience may be different".  In English-speaking countries that don't use Imperial miles, is there an equivalent expression? I want to fill a part of a picture with more or less evenly and randomly distributed circles which should not overlap. It would be okay if circles are only partly inside the shape.  The density should be like what you see on this page  with values 80-100. (But I do not need so many circles, 30 should be enough, I could repeat the pattern).   I cannot use a grid and "wobble" the circles a bit: The circles are too large and it simply does not look randomly.   Currently I am thinking about a random attempt: Get some random point, measure its distance to existing circles, either paint or throw the point away. Try 100 times and hope that you get the right number of circles (and that it does not take too long). But perhaps someone has a better idea.   The example draws the circles simply manually:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{backgrounds} \begin{document}   \begin{tikzpicture}[framed,gridded,radius=0.5cm]  \draw[red](0,0) rectangle (5,5);   \draw (1,1) circle;   \draw (2.3,1.1) circle ;   \draw (4.5,0.8) circle ;   \draw (5.1,1.8) circle ;   \draw (0.4,3.3) circle ;   \draw (2.1,2.8) circle ;   \draw (3.8,3.5) circle ;   \draw (4.8,4.2) circle ;   \draw (0.8,4.9) circle ;   \draw (2.1,4.1) circle ;   \draw (3.8,2.0) circle ;   \draw (3.5,0.6) circle ;   \draw (3.0,5.0) circle ;      \draw (4.1,5.1) circle ;             \draw (0.9,2.1) circle ;  \end{tikzpicture}  \end{document} Post Problem Analysis - Rod in a cylindrical time varying magnetic field? A metal rod of length $l$ is placed (as shown in figure) in a cylindrical time varying magnetic field. Find the potential difference across it.   My answer:  As electric fields as forming circles around the centre with magnitude $$\frac12r\frac{dB}{dt}$$ whose magnitude is same along any chord at a fix distance from centre: $$\Delta V=E.l=\frac12r\frac32at^{\frac12}.l$$ $$\Delta V=\frac34arlt^{\frac12}$$  My question: Is $\Delta V =V_M-V_N$ or $\Delta V=V_N-V_M$ $\bf OR$ equivalently which side is at high potential?  Possible    $(i)$ As Field lines are circular from $M$ to $N$, $M$ must be high potential. $(ii)$ As this field line apply a force on electrons- in the rod- towards left, then $M$ must have excess $e^-$ and $N$ must have deficiency; so $N$ would be high potential as $M$ is $(+)$ and $N$ is $(-)$. Deriving Newton's Third Law from homogeneity of Space How do I change the plymouth bootscreen? How can I serialize an object to JSON in JavaScript? How to calculate bounce angle? I played around with it for a while, but I simply can't figure it out.  I made a tank that fires missiles, and when the missiles hit the walls, I want them to bounce off, but I want them to bounce off to the right angle.  Right now I haven't got any obstacles, the missiles just bounce off when they get outside the viewportRectangle I made.  Is the solution I'm looking for quite advanced?  Is there a relativly simple way to do it? Last activity on question shows modified by user who did not ask or answer .       The  has no sign of the user sharth The  also does not have any sign of related activity   I would like to know why the user's name is associated with the question. At least why their display name shows up as having modified the question timeline activity.  Possible reason that I can think of is that, .  Is this the reason?  Is there a way (for normal users), to look for such details, other than looking at the user activity and the question's revision history.