How to get the Gnome Activities overview to only open when clicked on
Disable automatic activation of Gnome Shell activities on mouse over
How could it possible to factorise $x^8-1$ in product of irreducibles in the rings $(\mathbb{Z}/2\mathbb{Z})[x]$ and $(\mathbb{Z}/3\mathbb{Z})[x]$? How could it possible to factorize $x^8-1$ in product of irreducibles in the rings $(\mathbb{Z}/2\mathbb{Z})[x]$ and $(\mathbb{Z}/3\mathbb{Z})[x]$?  I'm having a hard time starting the problem. Could anyone help me at this point? Avoiding jumping frames in beamer Sometimes I want an element on a frame to change in steps. I do this by  \only&lt;2&gt;{   ...   }   \only&lt;3&gt;{   ...   }     etc.  But this causes the frame to jump due to different sizes of the included content. How can this be avoided? How to view recently opened media files? In windows we have an option to view recently opened media files as my recent documents, I was  wondering does there exists something like that in Ubuntu?  via terminal or via GUI? MySQL strip non-numeric characters to compare I'm looking to find records in a table that match a specific number that the user enters.  So, the user may enter 12345, but this could be 123zz4-5 in the database. I imagine something like this would work, if PHP functions worked in MySQL. SELECT * FROM foo WHERE preg_replace(&quot;/[^0-9]/&quot;,&quot;&quot;,bar) = '12345'  What's the equivalent function or way to do this with just MySQL? Speed is not important. How to enable or disable services? Good reasons to prohibit inheritance in Java? What are good reasons to prohibit inheritance in Java, for example by using final classes or classes using a single, private parameterless constructor? What are good reasons of making a method final? What is the difference between # and . when declaring a set of styles for an element and what are the semantics that come into play when deciding which one to use? Proof that the One-Dimensional Simple Harmonic Oscillator is Non-Degenerate? The standard treatment of the one-dimensional  (SHO) using the raising and lowering operators arrives at the countable basis of eigenstates $\{\vert n \rangle\}_{n = 0}^{\infty}$ each with corresponding eigenvalue $E_n = \omega \left(n + \frac{1}{2}\right)$. Refer to this construction as the abstract solution.  How does the abstract solution also prove uniqueness? Why is there only one unique sequence of countable eigenstates? In particular, can one prove the state $\vert 0\rangle$ is the unique ground state without resorting to coordinate representation? (It would then follow that the set $\{\vert n \rangle\}_{n = 0}^{\infty}$ is also unique.)  The uniqueness condition is obvious if one solves the problem in coordinate representation since then one works in the realm of differential equations where uniqueness theorems abound. Most textbooks ignore this detail (especially since they often solve the problem both in coordinate representation and abstractly), however I have found two exceptions:   Shankar appeals to a theorem which proves one-dimensional systems are non-degenerate, however this is unsatisfactory for two reasons:   Not every one-dimensional system is non-degenerate, however a general result can be proven for a large class of potentials (the SHO potential is in such a class). The proof requires a departure from the abstract solution since it classifies the potentials according to their functional properties.  Griffiths addresses this concern in a footnote stating that the equation $a \vert 0\rangle = 0$ uniquely determines the state $\vert 0\rangle$. Perhaps this follows from the abstract solution, however I do not see how. Do Arcane Ward's starting hit points include the INT modifier once or twice? An abjuration wizard's Arcane Ward states:     [...] The ward has hit points equal to twice your wizard level + your Intelligence modifier.   So how many hit points is this supposed to be?  \$ (2 \times WizardLevel) + INT_{mod}\$  or  \$2 \times (WizardLevel + INT_{mod})\$ ?  I feel like the phrasing hints toward the first calculation, but it's still somewhat ambiguous. Better explanation of the common general relativity illustration (stretched sheet of fabric) I've seen many science popularisation documentaries and read few books (obviously not being scientist myself). I am able to process and understand basic ideas behind most of these. However for general relativity there is this one illustration, which is being used over and over (image from Wikipedia):    I always thought that general relativity gives another way how you can describe gravity. However for this illustration to work, there needs to be another force, pulling the object down (referring to a direction in the attached image). If I put two non-moving objects in the image, what force will pull them together?  So where is my understanding incorrect? Or is general relativity not about explaining gravity and just describes how heavy objects bends spacetime (in that case the analogy is being used not correctly in my opinion)?    UPDATE Thank you for the answers and comments. Namely the XKCD comics is a spot on. I understand that the analogy with bent sheet of fabric pretty bad, but it seems that it can be fixed if you don't bent the fabric, but just distort the drawn grid.   Would you be so kind and answer the second part of the question as well - whether general relativity is explaining gravitational force. To me it seems that it is not (bending of spacetime simply can not affect two non-moving objects). However most of the time it is being presented that it does. A regular function can contain a call to itself in its definition, no problem.  I can't figure out how to do it with a lambda function though for the simple reason that the lambda function has no name to refer back to.  Is there a way to do it?  How? How can I make a bluish "white" LED less blue? Do fontsize environments exist? Without any doubt there are fontsize switches in the form of control sequences (described  for instance.) But, from time to time I ran into code examples where environment versions of those were used, e.g. \begin{small}...\end{small}. After testing those successfully I began to incorporate them into my TeX vocabulary.  A few days ago @GonzaloMedina commented on one of my answers that those environments do not exists and constructions relying on them work by pure coincidence. Then I tried to find out more about those ominous environments. Ominous because they don't seem to be somehow documentated. (The only thing I found that tried to explain them in a somehow systematical manner was some Wikibooks resource.)  Are these environments real or not? There's more gravitational force in our galaxy (and others) than can be explained by counting stars made of ordinary matter. So why not lots of dark planetary systems (i.e., without stars) made of ordinary matter? Why must we assume some undiscovered and unexplained form of matter? How to get the current directory in a C program? I'm making a C program where I need to get the directory that the program is started from.  This program is written for UNIX computers. I've been looking at opendir() and telldir(), but telldir() returns a off_t (long int), so it really doesn't help me.   How can I get the current path in a string (char array)? Drawing arrows on an HTML page to visualize semantic links between textual spans I have an HTML page with some textual spans marked up something like this:  ... &lt;span id="T2" class="Protein"&gt;p50&lt;/span&gt; ... &lt;span id="T3" class="Protein"&gt;p65&lt;/span&gt; ... &lt;span id="T34" ids="T2 T3" class="Positive_regulation"&gt;recruitment&lt;/span&gt; ...   I.e. each span has an ID and refers to zero or more spans via their IDs.  I would like to visualize these references as arrows.  Two questions:   How can I map an ID of a span to the screen coordinates of the rendering of the span? How do I draw arrows going from one rendering to another?   The solution should work in Firefox, working in other browsers is a plus but not really necessary. The solution could use jQuery, or some other lightweight JavaScript library. Simple combination/probability question based on string-length and possible-characters Assuming "complete randomness" and given a string with a length of 20 characters where each character may be one of 62 possible characters:    What are the total number of combinations possible? (Guessing 20 to the power of 62.)  Also, if new strings are randomly selected one after another and added to a list of strings selected so far, how many strings must be selected before the chance of selecting a string that has already been selected is below 1-in-100000 ($10^{-5}$)?   Note: 62 comes from: numeric digits (0-9), uppercase letters (A-Z), and lowercase letters (a-z). Stopping a Thread in Java? I'm in the process of writing a piece of code that connects to a server spawns a bunch of threads using that connection and does a bunch of "stuff".  There are certain instances where the connection fails and I need to stop everything and start from scratch with a new object.  I wanted to clean up after the object but calling thread.stop on the threads, but this method is seemingly deprecated.  What is the recommended alternative to doing this? Should I write my own cleanup and exit method for each of the threads? Set the thread to null? or something else? Casting of objects to dynamic types at runtime Find Orthogonal complement