My Bars on top and at left disappeared. I can now only right click and choose - change desktop background - Pressing Ctrl+Alt+T bring terminal out. Problem is I know nothing about it. There is now only my wall paper on the screen.
When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.
Do singularities have a "real" as opposed to mathematical or idealized existence? I was thinking of, for example a Schwarzchild metric at r=0, i.e. the gravitational singularity, a point of infinite density. I realise that there are different types of singularities--timelike, spacelike, co-ordinate singularities etc. In a short discussion with Lubos, I was a bit surprised when I assumed they are idealized and I believe he feels they exist. I am not a string theorist, so am not familiar with how singularities are dealt with in it.  In GR, I know the Penrose-Hawking singularity theorems, but I also know that Hawking has introduced his no-boundary, imaginary time model for the Big Bang, eliminating the need for that singularity. Are cosmic strings and other topological defects singularities or approximations of them (if they exist).  In what sense does a singularity exist in our universe? --as a real entity, as a mathematical or asymptotic idealization, as a pathology in equations to be renormalized or otherwise ignored, as not real as in LQG, or as real in Max Tegmark's over-the-top "all mathematical structures are real"? Can I change a user's keyboard input? How does quantum trapping with diamagnets work? I just saw  demonstration by someone from a Tel Aviv University lab.  What they achieved there is mind blowing. I myself own a levitron that uses the Hall effect to levitate a magnet, the problem with that is the magnet must always be flat facing the Hall effect base, any unbalance will wreck the levitation. But in the case of the video you can see that he isn't constrained by such things, the disk can levitate and stay still at whatever angle and orientation. Instead of being levitated, the disk is simply being held still.   How does this happen? He referred to this as quantum trapping, but I've little idea about what that is....  Also, what material is the base in these demos? Is the circular track in the demonstration magnetic? I assume this is so. Is there any conceivable way for this technology to make objects levitate on any surface? Easy way to switch default sound output device Why is it that logistic regression becomes unstable when classes are well-separated? What does well-separated classes mean? I would really appreciate if someone can explain with an example. Character Limit in HTML How do you impose a character limit on a text input in HTML? Adobe Illustrator: strange behavior while aligning objects I am creating icons with Adobe Illustrator during which process I use the Align tool quite frequently.  All of a sudden, the align tool started behaving quite strangely.  When I select two objects and specify that I want to align to a key object, when I press align it seems to only align halfway to where it should be.  When I press align again it aligns halfway again - after I press it several more times, it finally gets to where it needs to be.  Also, when I try to align to artboard, it pushes the object out to a seemingly random place.  Here is a video showing exactly what I mean:   What setting did I accidentally set to make align behave like this? How can I prove these statements? Compact space and Hausdorff space A continuous map from a compact space to a Hausdorff space is closed. Why this is true?  Help me please I want to learn why this is correct. I was reasonably certain I've seen this before, but I was wondering how to solve the Diophantine equation  $$a^2+b^2=c^2+d^2$$  I tried a web search and found nothing on this one.  I'm trying to avoid another library trip to a less than local library (maybe I should have taken better notes on that chapter...).  I'm not quite sure how to handle this one.  The only thing I can figure out with this equation, if I remember correctly, is that the sum on either side may only contain prime factors of 2 or odd primes congruent to 1 mod 4.  And if I don't want a and b equal to c and d, the sum can't be prime as I believe a prime congruent to 1 mod 4 can be represented as the sum of 2 squares in exactly one way.  But that doesn't give me any insight into actually solving this problem. Let $f: B(0,1) \rightarrow \mathbb{C}$ be holomorphic and suppose $\exists\ r \in (0,1)$ such that $f$ is injective in $A = \{z \in \mathbb{C} : r &lt; |z| &lt; 1\}$. Prove that $f$ is injective.  I tried using Rouché theorem, or the identity theorem, but I don't know what to do. Any hints? :) Allowing users to compile / run PLSQL and SQL As a DBA - assuming my users are knowledgeable with PLSQL and SQL - why would I not grant my users privileges to compile and run their own PLSQL code. We have an MI database environment where the data has undergone ETL. The tables contain a large numbers of rows but not necessarily large rows in size. The analysis - will be - I assume of calculus in nature. The users are wanting to run their own code on the data for the purposes of ad-hoc analysis - within their own schemas. They come from a SAS background which from my understanding has allowed them to write and run their own analysis of data. Albeit, SAS runs on its own dataset - extracted from Oracle or elsewhere.  In my opinion this is a dangerous set-up - but without answering my own question - what are the pitfalls? A friend of mine has some very old photos where the deterioration process seems to have increased in the past few years, and the owner is worried about the preservation of these old memories.  They have been stored inside an album within plastic sleeves. The owner is not aware of the display method prior to that.   I have been informed by the owner that since being in their possession, they seem to be looking worse than when first viewed and seem to be falling apart.   He is looking for the best way to preserve these photos inside an album, but not really sure what would be the best method. I have suggested for the albums as a whole to be stored in vacuum sealed bags for now, but I'm not even sure if that is good!  I am looking for any suggestions or personal experiences from anyone who has had to deal with such photos and what they did to preserve their memories. I'm trying to install bang and olufsen drivers, or HP hd audio driver, as only 2 of the 4 speakers work and the 2 amps don't work in ubuntu  lspci -v | grep -i audio 00:03.0 Audio device: Intel Corporation Broadwell-U Audio Controller (rev 09)     Subsystem: Hewlett-Packard Company Broadwell-U Audio Controller 00:1b.0 Audio device: Intel Corporation Wildcat Point-LP High Definition Audio Controller (rev 03)     Subsystem: Hewlett-Packard Company Wildcat Point-LP High Definition Audio Controller   The volume is terrible. Is there any way to fix this?  The speakers work perfectly on the pre-installed Windows 8. How to keep VLC player in minimized mode? I'm using VLC media player which can play almost all kinds of audio and video formats. While listening to audio, I keep VLC in minimized mode and can work on other windows. But when I select to listen video songs mixing with audio songs, VLC is maximizing itself to play every video song in the playing list, which is really annoying in the middle of work.  So how can I keep always VLC player in minimized mode while playing a list of songs mixed with audio and video songs? How to compute prediction bands for non-linear regression? Total number of solutions of an equation What is the total number of solutions of an equation of the form $x_1 + x_2 + \cdots + x_r = m$ such that $1 \le x_1 &lt; x_2 &lt; \cdots &lt; x_r &lt; N$ where $N$ is some natural number and $x_1, x_2, \cdots, x_r, m$ are integers?  Also, what would be the solution in the relaxed case where $x_1, x_2, x_3, \dots, x_r$ could be equal? Word for "things which exist" I have an empty file (only zeroes are in it) of size 9,0KB and I need to write another file (with size 1,1KB) to it, but the first file must not lose its size or the rest of its contents. So if the whole file is 00000000000000... now, I need to write second file in it and leave the zeroes as they are. I have tried to use dd, but I haven't succeed - file resizes.  dd if=out/one.img of=out/go.img   Does anybody know how can I do it? AppleScript to choose item on web page Is it possible with AppleScript to choose a clickable element in a web page and click it and if so, can you give me an example?