Centering input field
Best way to center a  on a page vertically and horizontally?
INSERT takes over 5 hours, when inserting more than specific number of rows When inserting less then about 1,350,000 rows to the table it all takes about 2 minutes, however when number of inserted rows is bigger, then the time needed to insert data grows to about 5 hours.  The problem is not connected with query or indexes, because everything has been working fine for a long time and nothing has changed in the structure of query, tables or indexes.   Problem appeared for the first time about 2 weeks ago and it appears repeatedly on days, when number of inserted rows is bigger than +-1,350,000. For example on one day number of inserted rows is 1,200,000 and the process takes 2 minutes, on the other day number of rows is 1,450,000 and it takes 5-6 hours to insert data.  I tried to rebuild indexes, but it has not helped. How to view/erase images from both CF and SD cards on Canon EOS 5D mk3? I've been trying to setup my Canon EOS 5D mk3 to shoot in "backup mode". I have two cards:    32GB CF  8GB SD   I've set it like the following:  SET UP1 menu ------------ Record func.:       Rec. separately Playback:           1 [CF]  SHOOT1 menu ------------ Image type/size CF: RAW 22M Image type/size SD: JPEG 9,8M   It works ok, except I have one problem. Since I have only these two cards, on some large shoots I need to erase some in order to free some space to make the card last till the end of shoot.  When viewing images and deleting the ones I want to delete, it seems that I can only see the contents of the CF card, and when I delete an image I delete only the RAW file saved on the CF.  Is there a way to delete the JPEG from the SD card along with it's RAW "parent" on the CF card? How do I prevent widow/orphan lines? How can I set mouse sensitivity, not just mouse acceleration? A question about eigenvalues of $5\times5$ matrix $A\in M_5({R})$  and $A^2-4A-I=0$ If $a_1,a_2,a_3,a_4,a_5$ are eigenvalues of $A$ what is value of $$\left(a_1-\dfrac{1}{a_1}\right)+\left(a_2-\dfrac{1}{a_2}\right)+\cdots+\left(a_5-\dfrac{1}{a_5}\right)$$ I tried to work with $A^2-4A-I=0$ but get nothing because $A_{5\times5}$ characteristic polynomial is something like $A^5+k_1A^4+...$ Any hint will be appreciated . $n^2 + 3n +5$ is not divisible by $121$ Question:  Show that $n^2 + 3n + 5$ is not divisible by $121$, where $n$ is an integer. How do I make environment variable changes stick in Python? From what I've read, any changes to the environment variables in a Python instance are only available within that instance, and disappear once the instance is closed.  Is there any way to make them stick by committing them to the system?  The reason I need to do this is because at the studio where I work, tools like Maya rely heavily on environment variables to configure paths across multiple platforms.  My test code is  import os os.environ['FAKE'] = 'C:\\'   Opening another instance of Python and requesting os.environ['FAKE'] yields a KeyError.  NOTE: Portability will be an issue, but the small API I'm writing will be able to check OS version and trigger different commands if necessary.  That said, I've gone the route of using the Windows registry technique and will simply write alternative methods that will call shell scripts on other platforms as they become requirements. Clearing all cookies with JavaScript Website with a collection of sci fi stories set in the same universe; powerful AIs being regarded as Gods, one named Gaia, and a "technopocalypse" There is a site with lots of stories all set in a future with super powerful AIs regarded as Gods, the most powerful being matrioshka brains. They have a specific terminology but I can't remember their names. Earth has been converted into a similiar godlike computer called "Gaia" and has expelled all humans creating a dystopian exodus across the solar system. And something about rogue Von Neumann machines causing a huge crisis dubbed the "technopocalypse". Unintentional mouse movements, am I paranoid? Searching through ODT documents without opening them? Let's say I have 2000 .ODT files. Their names are random numbers. How do I go about searching for, let's say, "pricing list"? How do I find the document I need without opening all of them one by one and checking to see if it's the right one?  Is there some program to search through the words in the documents without opening them? Paperback novel about a man who kills a birdlike alien on his balcony with a watering can I am trying to prove this binomial identity $\sum_{r=0}^n {r {n \choose r}} = n2^{n-1}$ but am not able to think something except induction,which is of-course not necessary (I think) here, so I am inquisitive to prove this in a more general way.  The left side of an identity occurs while solving another problem (concerning binomial theorem) so I am more interested in deriving the right side from the left side, else I have to remember it now onward.  EDIT: I am more interested in an algebraic proof rather than combinatorial argument or something involving calculus (however I liked  and  solution), hence I am removing the combinatorics tag. change caption in list of tables I would like to change the caption in the List of Tables in a way it is different from the caption in the corresponding table. How can I do that? Does there exist a command to do that? There has been some recent behavior change on SE (around July 2015).  I have two accounts I use, one Google openId based for one set of sites (call it Account-A) and another SE login based for a different set of sites (Account-B).  Used to be that I could be logged into one set of sites with the first user and a different set with the other users.    But now I am logged in with the Account-A on Site-1.  When I go to one of the sites I use the other account for and click "log in" under the SE menu, I go to a page where I only have an option to confirm creation of an account based on my Google login.  It does not present a way to log in with an SE account.    How can I log in with my other account here?  (and before you flag this as a duplicate, please ensure the other question is recent enough and that the answer is relevant.  This behavior has definitely morphed over the years... and I am having trouble finding something that is relevant.  For instance this question  simply points out how to merge the accounts which is NOT what I want  .  This question  talks about presenting different user info on each site but that's not what I want -- I want totally separate accounts). Are "if" and "iff" interchangeable in definitions? In some books the word "if" is used in definitions and it is not clear if they actually mean "iff" (i.e "if and only if"). I'd like to know if in mathematical literature in general "if" in definitions means "iff".  For example I am reading "Essential topology" and the following definition is written:     In a topological space $T$, a collection $B$ of open subsets of $T$ is said   to form a basis for the topology on $T$ if every open subset of $T$ can be written as a union of sets in $B$.   Should I assume the converse in such a case? Should I assume that given a basis $B$ for a topological space, every open set can be written as a union of sets in $B$?  This is just an example, I am not asking specifically about this sentence. If I calculate the median of a sufficiently large number of observations drawn from the same distribution, does the central limit theorem state that the distribution of medians will approximate a normal distribution? My understanding is that this is true with the means of a large number of samples, but is it also true with medians?  If not, what is the underlying distribution of sample medians? Why is the sky dark at night? The question is the well-known      If there are so many/infinite stars, in every direction, why is it dark at night? Where goes all the light we don't see?    Discussing with a friend we found different answers.   The first (my friend's answer) is that given the fact that in a finite amount of time (in this case, the age of the universe), light can travel only a certain, finite, distance, we cannot see, if they actually exist, stars farther than such distance (about 13 billions of years, I guess). Then he states (or better, I got him notice he implicitly does this)  that within this radius there aren't enough stars to fill the night sky, and that's why we have darkness without sun's light.   The second answer (mine, or anyway the one I heard from a minutephysics YouTube video) is that despite of the big size of the observable universe, cosmological expansion red shifts most of the light out of the visible radiation range, so that the majority of light can't be seen by our eyes at night, while if we use, for example, an infrared camera, we should see a brighter sky, and lenghtening more and more the wavelength at which we observe the sky, we come to the uniform background radiation.  So my question is, what is the right answer? Is it one of the above-mentioned or even a third one?  EDIT: I've seen both answer may be acceptable, but what is the main contributing phenomenon? What is a "hat"? What exactly is a hat?  I have seen a lot of people arguing the significance of hats and the limited edition hats. I know the hats are sort of linked to the Winterbash stuff, but what exactly is a hat, what does it do, how do I get one?  Is there a full list of hats? Is past simple ever justified with 'by'? Can anyone shed some light on the following aspect?  By 5 PM I gave him the book.  By 5 PM I had given him the book.  In both the sentences the book was given before 5 PM and no later than 5 PM. But I can't understand then what the difference between them is. a Also is it right to use simple past with 'by' at all? If yes, then why and if not, then why is it incorrect to use simple past with 'by'?