How long can I keep espresso in the fridge?
How long is it safe to drink coffee after brewed?
Feynman diagram for attractive forces Should questions where a problem arose from a typo be closed? Should questions where a problem arose from a typo be closed?  Here is a recent example:    The problem was a misspelled _gaq (written as _gat).   Should these be closed? Surely they're of no use to anyone once the OP recognizes the mistake. If so, what justification should be given? Not a real question? Too localized?     Just to be clear, the question linked above actually was not broken due to a typo. This was my mistake, and raises some other interesting questions. See the discussion below.  If anyone feels like editing this question with examples of actual typo questions, go for it. I've been working on some animations recently, and I've noticed that I'm having poor luck with certain things, namely the fact that I don't really use Blender's graph editor very well.  One of the major issues that I have is pretty widespread among 3D graphics programs; when I create an animated object, it defaults to using a curved graph instead of a linear graph, which means that the most movement is at the middle of the animation, and stuff just practically stops near the beginning or the end. While this helps with organic camera movements or such, it's also not what I usually want. Can I set animation curves to default to linear? What are all the correct answers to the Squirrel's questions, and what is the reward when I get them all correct? I encountered The Squirrel at "A tree."              |   |                                                                         |   |                     "   Hello, I'm The                        |             |                        Squirrel. I can                        |             |                      provide you candies,                     |             |                      and lots of things.                                    |                      I know how much you                                    |        _.-'''-,      love candies. But I                                    |      .'        `\     feel alone in this                                    |     /           /          forest.       "                         |        |    /      .--^_^                                                   |        |    |     /  C ,,\                                                           |    |    |   \  _.)                           ___                            |     \   |   /  \                   ____.----'.-'                            |      '-, \./ \)\)               .-' --  __.-'                   |            \        `-/   );/           ___/  - _.-'                        |             \_________''--'-'________.-' --    /                            |              -   --        -  -     -     __.-'                                              -    --    -     --   --  /                                                 _________________________.-'                                 He asks you some questions. What are the correct answers, and what is the reward for getting them correct? How does DC work with natural 20? How do I write this matrix as a product of elementary row matrices. \begin{pmatrix}3&amp;-1&amp;3\\ -2&amp;3&amp;2\\ 1&amp;-3&amp;1\end{pmatrix}  Any help would be greatly appreciated!  I have done this before with other matrices, yet this one is bringing me trouble. I have spent too long on this as I believe it should be easy and yet my answers are always wrong. What Do you do after you get the identity matrix?  What I am doing: So I first row reduce it to the identity matrix:   I first switch $R_1$ and $R_3$ Then $R_3-3R_1$ then $R_2+2R_1$ then $-1/3R_2$ then $R_3-8R_2$ then $R_2-2R_1$ then $3/32R_3$ then $R_1+3R_3$ and finally $R_2+4/3R_3$   I know there is many possible ways to get this too the identity matrix but this worked for me. I then apply all of the above steps to identity matrices and multiply them together to check my work but it never works out to be the original matrix so I am forced to believe something is wrong. 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 $(-)$. Compute the moment generating function of $Y = X_1X_2 + X_1X_3 + X_2X_3$ We roll a six-sided die ten times. What is the probability that the total of all ten rolls is divisible by 6? So the question is really hard I think. I tried using a simple way by calculating the probability of each combination that makes a sum divisible by six, but it would take forever. Does anyone have any ideas?  Suppose that we roll a six-sided die ten times. What is the probability that the total of all ten rolls is divisible by six? I always stumble when using abbreviations in a sentence, as they inherently contain a period in them. How do I use a comma or a semicolon after an abbreviation? How about a period?  E.g. (This is an example of my quandary) I'm trying to get:  document.createElement('div')  //=&gt; true {tagName: 'foobar something'}  //=&gt; false   In my own scripts, I used to just use this since I never needed tagName as a property:  if (!object.tagName) throw ...;   So for the second object, I came up with the following as a quick solution -- which mostly works. ;)  The problem is, it depends on browsers enforcing read-only properties, which not all do.  function isDOM(obj) {   var tag = obj.tagName;   try {     obj.tagName = '';  // Read-only for DOM, should throw exception     obj.tagName = tag; // Restore for normal objects     return false;   } catch (e) {     return true;   } }   Is there a good substitute? Are you less likely to down-vote someone whose gravatar is a photograph of them? I know this is hard to answer since, to the extent that anyone does this, they likely don't do it consciously. In the spirit of Richard Wiseman and  I just wondered what were people's thoughts on it.  Please bear in mind that that's me in the picture, and if you down-vote this, that'll be a real person hurtin', not some abstract symbol. Derivation of the formula for Ordinary Least Squares Linear Regression How was the formula for Ordinary Least Squares Linear Regression arrived at?  Note I am not only looking for the proof, but also the derivation. Where did the formula come from? `time echo` got no output Double orthogonal complement is equal to topological closure Can a person residing in Singapore on a 5-month Employment Pass apply for a Schengen visa? How do I block unwanted callers without jailbreaking? How to cancel a credit card and verify it was closed Taxonomy terms view sorting results numerically I have a taxonomy that's comprised entirely of numeric term names, 1 through 1200 (with a few numbers missing in between). I created a new "Taxonomy terms" view to show all terms in this vocabulary. When I look at the view results, I'd like to see the terms sorted numerically, however the view is displaying the terms alphabetically. I understand the reason for this is because term names are strings, but I'm hoping someone has an answer of how to make the query treat the term names as integers.  Here's an example of the view results as they are displayed now:   1 10 100 1000 1001 1005 101 1014 1015 1016 1019 102 1020 1024 103 1034 104   Normally in MySQL, you could write SELECT name FROM {taxonomy_term_data} ORDER BY CAST(name AS UNSIGNED). Is there a way to get this same type of CAST() happening in views? I ran into an interesting behavior recently.  It seems that if I override .equals() to take a parameter other than Object, it doesn't get called.  Can anyone explain to me why this is happening?  It seems to violate my understanding of polymorphism in OOP, but maybe I'm missing something.  Here's much simpler code that shows what I'm seeing:  public class MyClass {   private int x;   public MyClass(int n) { x = n; }   public boolean equals(Object o) { return false; }   public boolean equals(MyClass mc) { return x == mc.x; }   public static void main(String[] args) {     List&lt;MyClass&gt; list = new ArrayList&lt;MyClass&gt;();     list.add(new MyClass(3));     System.out.println("Contains 3? " + list.contains(new MyClass(3)));   } }   When this is run, it prints "Contains 3? false".  It looks like the equals(Object) function is called, even though there is another that would work.  By contrast, if I write equals like this the code works as expected:  public boolean equals(Object o) {   if(!(o instanceof MyClass))     return false;   MyClass mc = (MyClass)o;   return x == mc.x; }   Why isn't it figuring out which version of the function to call based on the type of the parameter?