got closed as duplicate of .  The later question is both better worded (also has more votes) and better answers (more votes, and a workaround that's not in the original.)  Shouldn't there be an option to close an older question as an inferior duplicate of a newer question?  Or does the long-tail answer always have to be the older inferior question?
What's everyone's opinion on closing an older question as a duplicate of a newer one, if the newer one is clearly the better resource? I'm looking at a special case right now, where the two were posted by the same person; the  was migrated to SU before a commenter pointed out it was a . Is it considered good practice to close the older as a duplicate of the newer?  More generally, is it ok to do that for separate questions posted by different people, if the older question went unanswered but the newer has a good answer?  (I should probably mention I saw , but I think this is separate)
Saving image from PHP URL I need to save an image from a PHP URL to my PC. Let's say I have a page, http://example.com/image.php, holding a single "flower" image, nothing else. How can I save this image from the URL with a new name (using PHP)? How to check if jQuery.ajax() request header Status is "304 Not Modified"? How do I give myself an item that can only be placed on a block with a certain damage value? I'm currently in the process of making a custom map and I want to add blocks that can only be placed on a certain colour clay.  This is the command I tried using.  /give @p cobblestone 1 0 {CanPlaceOn:["hardened_stained_clay"],Damage:3}   However, even with this command the cobblestone can be placed on any colour of stained clay. What command can I use for placing only on a certain block? Why do we have wrinkly fingers after swimming? I found an explanation for my question here , which suggests that water washes out sebum (special oil, which covers our skin) and water gets into outer layer of now unprotected skin by osmosis. This article also suggests that fingers are not really shriveled - they are water-logged. But is this right? I think I observed many times my wrinkly fingers after swimming, but I never felt that they are water-logged. Any thought on this matter would be highly appreciated. I'm having a really, really hard time figuring out how to install mods on Minecraft. I've looked everywhere I can think of for help but the information is almost always outdated or unhelpful.  I've seen on several sites about the use of something called Forge. The Mod I want to use requires 1.6.4 Forge and I have both Forge and the Mod folders sitting in my downloads folder.  I haven't installed any kind of mods for any game prior to this and I have little clue to the technical side of Minecraft, so please keep this in mind when you give me an answer please!  Things that might help you figure out how to help me:   I want to play this mod  and am using the 1.6.4 Forge given on a link that website gives Now, that Adobe has stopped issuing new releases for Linux desktops, the only option for users is to use Google Chrome, for those who want to use the latest Flash updates. I use Chromium. Is there any way to get Chromium use the Flash from Google Chrome? The reason I as this question is that I have noticed both these browsers run in the background, so technically, the browsers' plugins are available to use. Top Down RPG Movement w/ Correction? I would hope that we have all played Zelda: A Link to the Past, please correct me if I'm wrong, but I want to emulate that kind of 2D, top-down character movement with a touch of correction. It has been done in other games, but I feel this reference would be the easiest to relate to.  More specifically the kind of movement and correction I'm talking about is:   Floating movement not restricted to tile based movement like Pokemon and other games where one tap of the movement pad moves you one square in that cardinal direction. This floating movement should be able to achieve diagonal motion. If you're walking West and you come to a wall that is diagonal in a North East/South West fashion, you are corrected into a South West movement even if you continue holding left (West) on the controller. This should work for both diagonals correcting in both directions. If you're a few pixels off from walking squarely into a door or hallway, you are corrected into walking through the hall or down the hallway, i.e. bumping into the corner causes you to be pushed into the hall/door.   I've hunted for efficient ways to achieve this and have had no luck. To be clear I'm talking about the human character's movement, not an NPC's movement. Are their resources available on this kind of movement? Equations or algorithms explained on a wiki or something?  I'm using the XNA Framework, is there anything in it to help with this? Set root domain record to be a CNAME I need to create an NS record for a domain that is a CNAME, for the purpose of having two domains pointed at one IP, and not having to maintain the current IP address in two different places.  The DNS provider for this domain is DynDNS, but they block this operation:     CNAME cannot be created with label   that is equal to zone name   I can do this with another domain whose DNS is served by 1and1:  root@srv-ubuntu:~# dig myseconddomain.co.uk  ; &lt;&lt;&gt;&gt; DiG 9.4.2-P1 &lt;&lt;&gt;&gt; myseconddomain.co.uk ;; global options:  printcmd ;; Got answer: ;; -&gt;&gt;HEADER&lt;&lt;- opcode: QUERY, status: NOERROR, id: 61795 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0  ;; QUESTION SECTION: ;myseconddomain.co.uk.             IN      A  ;; ANSWER SECTION: myseconddomain.co.uk.      71605   IN      CNAME   myfirstdomain.co.uk. myfirstdomain.co.uk.     59      IN      A       www.xxx.yyy.zzz  ;; Query time: 298 msec ;; SERVER: 10.0.0.10#53(10.0.0.10) ;; WHEN: Tue Aug 18 14:17:26 2009 ;; MSG SIZE  rcvd: 78   Is this a breach of the RFCs or does DynDNS have a legitimate reason for blocking this action?  Followup Thanks to the two answers already posted I now know that 1and1 IS breaching RFCs to do this. However it does work and they seem to support it. For a company that hosts so many domains it seems very odd that they get away with doing this on such a massive scale without objection.  More followup  The output of "dig myseconddomain.co.uk ns" as requested.  root@srv-ubuntu:~# dig myseconddomain.co.uk ns  ; &lt;&lt;&gt;&gt; DiG 9.4.2-P1 &lt;&lt;&gt;&gt; myseconddomain.co.uk ns ;; global options:  printcmd ;; Got answer: ;; -&gt;&gt;HEADER&lt;&lt;- opcode: QUERY, status: NOERROR, id: 18085 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2  ;; QUESTION SECTION: ; myseconddomain.co.uk.             IN      NS  ;; ANSWER SECTION: myseconddomain.co.uk.      4798    IN      NS      ns67.1and1.co.uk. myseconddomain.co.uk.      4798    IN      NS      ns68.1and1.co.uk.  ;; ADDITIONAL SECTION: ns67.1and1.co.uk.       78798   IN      A       195.20.224.201 ns68.1and1.co.uk.       86400   IN      A       212.227.123.89  ;; Query time: 59 msec ;; SERVER: 10.0.0.10#53(10.0.0.10) ;; WHEN: Wed Aug 19 12:54:58 2009 ;; MSG SIZE  rcvd: 111 Verb form of "must needs" Then touching the shoulder of a townsman who stood near to him, he addressed him in a formal and courteous manner:      "I pray you, good Sir," said he, "who is this woman? -- and wherefore is she here set up to public shame?"      "You must needs be a stranger in this region, friend," answered the townsman, looking curiously at the questioner and his savage companion, "else you would surely have heard of Mistress Hester Prynne and her evil doings. She hath raised a great scandal, I promise you, in godly Master Dimmesdale's church. "   As far as I know we always use first form of the verb after "must". For instance: "You must go". We never say "You must goes". Also, we never use -s/es with a verb that comes with "You". What are the circumstances in which writer has used "needs" after "You must" in "You must needs to be a stranger in this region."? How to tell what method was used to log in (Password vs. Keyfile) from the bashrc Is there a way how you can check what auth method the user which just logged in to an account were using?  I like to print out a warning after login if someone is using a password instead of a keyfile.  Sure one solution is to check the ssh-logs. But is there a nicer way to do this? Since looking up logs could impact performance depending on the log size and method you use to gather this information.  We are using SUSE and Ubuntu. Bypass BIOS password set by faulty Toshiba firmware on Satellite A55-S1065 laptop? What is the relationship between the focal length and field of view for an equal-area ("equisolid") projection fisheye lens?  Alternatively, what is the relationship between the 180-degree image circle size and the focal length for such a lens?  Ultimately I want to find the field of view of a Tokina 10-17 mm fisheye zoom at focal lengths other than 10 mm on APS-C (). Defining the Complex numbers I posted this question nearly 10 days ago, but am still really not satisfied with the answers I got, I have no prior education in abstract algebra, group theory, or other abstractions, and most of the answers I got involved defining sets, groups and other things I am unfamiliar with, my question was,  How does one know the notion of real numbers is compatible with the axioms defined for complex numbers, ie how does one know that by defining an operator '$i$' with the property that $i^2=-1$, we will not in some way contradict some statement that is an outcome of the real numbers.  For example if I defined an operator x with the property that $x^{2n}=-1$, and $x^{2n+1}=1$, for all integers n, this operator is not consistent when used compatibly with properties of the real numbers, since I would have $x^2=-1$, $x^3=1$,thus $x^5=-1$, but I defined $x^5$ to be equal to 1.  How do I know I wont encounter such a contradiction based upon the axioms of the complex numbers.  I reiterate here again, Please don't use terminology, or abstract math, that hasn't been taught in say a thorough collage level calculus 1 course.  Here's a link to the same question I asked 8 or so days ago: Can Cycles renders be done from the command line? It seems that Cycles is mainly built in the form of Python scripts (as far as I can tell). Is it still possible to use Cycles to render a .blend file from the command line? How to calculate the correct focal length needed for a subject of a given size and distance? I need to purchase my first ever lens. So far I've only used lenses that were built into a camera. This specific lens is for the BlackMagic Deign Pocket Cinema Camera (a video only camera, but one that uses photography lenses). I would prefer this to be a prime lens.  I have tried to find the exact way to calculate the focal length of the lens I need but I have not been able to find a good resource to make this simple enough for my limited optics knowledge. Can you please explain a simple way to calculate the focal length of a lens given the following inputs as an example:    I would prefer a simplified mathematical explanation so that I may use it to make similar determinations in the future using a "" method.  I have . Using that method, I came up with:  Required lens focal length = 7.02mm sensor height x (77in / 36in) = 15mm   Is that correct? How to use more than 10 tab stops in bmatrix or other amsmath matrix environments? I'm using bmatrix environment from the amsmath package, and I'm trying to do something like this:  \documentclass{article} \usepackage{amsmath}   \begin{document}      \begin{equation}          \begin{bmatrix}              1 &amp; 2 &amp; 3 &amp; 4 &amp; 5 &amp; 6 &amp; 7 &amp; 8 &amp; 9 &amp; 10 &amp; 11\\          \end{bmatrix}     \end{equation}  \end{document}   However, pdfLaTeX returns an error: "Extra alignment tab has been changed to \cr", and in the output the extra element is moved to the next row. (If I remove one element, then it works perfectly fine). I guess this means that I've hit some hard limit on the number of tab stops in a matrix. Is there a way to change this?  The elements in the matrix are short and could fit perfectly on a single row. Is the Ratio of Associative Binary Operations to All Binary Operations on a Set of $n$ Elements Generally Small? I started thinking about the number of associative (binary) operations on a set with $n$ elements today.  Looking online I found  which indicates only $113$ of the possible $19,683$ operations on a three-element set satisfy association.  So, $50\%$ of binary operations on a two-element set satisfy association, and less than $0.6\%$ of all binary operations on a three element set satisfy association.  For an $n$-element set, where $n$ denotes a natural number, is the ratio $R_{n}=A_{n}/B_{n}$, of the number of associative binary operations $A_{n}$ to the number of all binary operations $B_{n}$, in general small?  I don't mean the following questions as equivalent, but since they seem more concretely answerable in principle, does   $$ \lim_{n \to +\infty} \frac{A_{n}}{B_{n}} = 0 ? $$       Also, is $F : n \to R_{n}$ a monotonically decreasing function?  Some Background of the Question: In his Linear Algebra Problem Book 1995 on p. 6 Paul Halmos writes "The commonly accepted attitudes toward the commutative law and the associative law are different.  Many real life operations fail to commute; the mathematical community has learned to live with that fact and even to enjoy it.  Violations of the associative law, on the other hand, are usually considered by specialists only."  For all I know, Halmos might only have written that to motivate the study of Linear Algebra and doesn't quite literally mean what he appears to say.  But, if he means what he appears to say, and if $F : n \to R_{n}$ is monotonically decreasing, or $R_{n}$ is generally small, I think there's something amiss with what Halmos says, since non-associative operations seem so common that one may as well enjoy them. Height/Radius ratio for maximum volume cylinder of given surface area C programming: How to program for Unicode? How would you prove the following limit?  $$\lim_{(x,y) \to (0,0)} \frac{x^3y}{x^4+y^2} = 0$$  I think the best way is using the squeeze theorem but I can't find left expression.  $$0 \le \frac{x^3y}{x^4 + y^2} \le \frac{x^3y}{x^4} \le \frac{x^3y}{x^3} \le y = 0.$$  But I'm not sure I'm right (especially at $\frac{x^3y}{x^4} \le \frac{x^3y}{x^3}).$  If I'm right - I'd glad if you can accept it.  If I'm wrong - can you please correct me?  Thanks in advance!