How to convert text within a textarea into a URL like Facebook does?
How to replace plain URLs with links?
Spivak Chapter 2, problems 27 (and 28) To be honest, I have no idea how to even start this problem. I'm sorry I don't have any work to show, but I'm just at a blank. Help?  Chapter 2: Problem 27:  University B, once boasted $17$ tenured professors of mathematics. Tradition prescribed that at their weekly luncheon meeting, faithfully attended by all $17$, any members who had discovered an error in their published work should make an announcement of this fact, and promptly resign. Such an announcement had never actually been made, because no professor was aware of any errors in her or his work. This is not to say that no errors existed, however. In fact, over the years, in the work of every member of the department at least one error had been found, by some other member of the department. This error had been mentioned to all other members of the department, but the actual author of the error had been kept ignorant of the fact, to forestall any resignations. One fateful year, the department was augmented by a visitor from another university, one Prof. X, who had come with hopes of being offered a permanent position at the end of the academic year. Naturally, he was apprised, by various members of the department, of the published errors which had been discovered. When the hoped-for appointment failed to materialize, Prof. X obtained his revenge at the last luncheon of the year. &quot;I have enjoyed my visit here very much&quot;, he said, &quot;but I feel that there is one thing that I have to tell you. At least one of you has published an incorrect result, which has been discovered by others in the department.&quot; What happened the next year?&quot;   Chapter 2: Problem 28:  After figuring out, or looking up, the answer to Problem 27, consider the following: Each member of the department already knew that Prof.X asserted, so how could his saying it change anything? If I put my phone on my notebook's left corner, it shuts down. Can anybody give me reliable explanation as to why this is happening?? Looking at the questions and answer to these two questions.  &amp;  and neither mentions the longevity of magic. I recall several instances of magic failing to last; the money that was spread at the  and the broken  on.  If I recall correctly when Voldemort died, the curses on several people were lifted.  I don't recall if any other spells fell apart with his death.  Is there any canon evidence on the the length of time a spell will live? Effectively creating this effect in Illustrator? Been lurking awhile but this is my first post.   I've always wondered what this effect is called and I'm almost certain there's an easier way to doing it than how I do it. I'm talking about the "empty" stroke around overlapping parts of icons.   In this case I would put a stroke that's the color of the background around the first character. I know this is bad practice for many reasons, but I haven't found a way to use the pathfinder to do this.  I'm looking for a way to do it that would effectively cut away the shapes smoothly in a X amount of pixels around a certain shape instead of covering it up so I can save the icon and use it over whatever colored background I want to.  I'm guessing I'm not the first person to ask this but I have no earthly clue how this effect is called so my research has returned nothing relevant. Change this behavior to allow for spelling corrections and the like: "Edits must be at least 6 characters" Are there irreducible polynomials that are partially solvable by radicals? In general, polynomials of degree 5 or higher, with rational coefficients, are not solvable by radicals. There are some exceptions and trivial cases, for example $x^5-5x+12$ and $x^{100}+x^{25}+3$, respectively.  All irreducible polynomials with rational coefficients, that I am aware of, have either none or all roots that can be expressed by radicals.  Do partially-solvable irreducible polynomials exist? If they do, are there any examples known?  I mean, for example, an irreducible polynomial of $n$th degree that can be split over $Q(\sqrt{2})$ into two polynomials of 3rd and $(n-3)$th degrees, where the polynomial of $(n-3)$th is not solvable by radicals.    At  Alexander Gruber wrote:     Polynomials which are not solvable by radicals have (at least one) root that cannot be written by any combination of the operations of addition, multiplication, and the taking of nth roots.   I am not sure if he meant only reducible polynomials, and/or with non-rational coefficients, as polynomials that have "at least one" root that cannot be expressed by radicals. I'm looking for a site, similar to StackOverflow, but with possibility to ask opinion based questions Since opinion based questions are not allowed neither here nor on stackoverflow, I would like to ask if any of you, know some other web page (outside Stack* ecosystem), where we can ask questions like:  "Which Java Web framework would you recommend to learn"   or any other, which by nature are opinion based.  EDIT1:  Allow me to explain a bit more - I know there are webgroups, forums and mailing lists BUT most of those are for single programming language or framework and I'm looking for something more generic. Stackoverflow is great because there are experts from all sort of programming languages and frameworks, so if it would be allowed to ask:   "Best web frameworks similar to ASP.NET MVC4"  I would get a lot of opinions, from different languages and frameworks, and that exactly what I'm looking for. R version 3.1.1 (2014-07-10) -- "Sock it to Me" &gt; bl &lt;- c(140, 138, 150, 148, 135) &gt; fu &lt;- c(138, 136, 148, 146, 133) &gt; t.test(fu, bl, alternative = "two.sided", paired = TRUE) Error in t.test.default(fu, bl, alternative = "two.sided", paired = TRUE) :  data are essentially constant   Then I change just a single character in my fu dataset:  &gt; fu &lt;- c(138, 136, 148, 146, 132)   and it runs...  &gt; t.test(fu, bl, alternative = "two.sided", paired = TRUE)      Paired t-test   What am I missing here? Let $G$ be a finite group of order $n\ge2$. Which of the following statements are true? a. There always exists an injective homomorphism from $G$ into $S_n$. b. There always exists an injective homomorphism from $G$ into $S_m$ for some $m\lt n$. c. There always exists an injective homomorphism from $G$ into $GL_n(R)$.  I think b. is right (don't know how to prove though). I also think that c. is false. But not sure. QGIS area calculation differs when on the fly CRS transformation enabled When I open QGIS, add the layer, and calculate the areas of the shapefile via field calculator I get a different area than when I open QGIS and check "Enable on the fly CRS transformation" and calculate the area. This is despite making sure that the project and the layer have the same Coordinate system (same EPSG number). What am I doing wrong?   I have a shapefile with area calculations made with ArcGIS (not be me, the data was handed to me and I have no clue for which CRS the area was calculated with ArcGIS). The shapefile layer CRS is EPSG: 21781 (Switzerland). In QGIS, if I do not change the OTF settings and leave the project CRS as EPSG:4326 (WGS84) I get the same value as the ArcGIS area value. However, if I change the OTF before adding the layer to EPSG: 21781 I get different area values. As I understand this suggests that ArcGIS Area was calculated with the CRS EPSG: 4326.  First workflow:   open QGIS  project CRS: EPSG 4326  add layer  project CRS adapts automatically and is EPSG 21781 now  calculate $area with field calculator    Second workflow:   open QGIS  project CRS: EPSG 4326  Turn on OTF, set project CRS to EPSG 21781  add layer  calculate $area with field calculator    Step 5 of the first and second workflow DO NOT produce the same area. Errors in matrix equation? I'm getting errors in a matrix equation. When I compile it looks fine, but I'd like to fix them so I don't have to press return for every error at compile time. The code for the equation is:  \begin{equation*}  \begin{bmatrix} U(1,t)  &amp; \cdots &amp; U(n,t) \\  \vdots &amp; \ddots &amp; \vdots \\ O_{n1} &amp; \cdots &amp; O_{nn}  \end{bmatrix} \times \begin{bmatrix} W(1,1)  &amp; \cdots &amp; W(1,n) \\  \vdots &amp; \ddots &amp; \vdots \\  W(n,1) &amp; \cdots &amp; W(n,n)  \end{bmatrix} = \begin{bmatrix}  D(1,t)  &amp; \cdots &amp; D(n,t) \\ \vdots &amp; \ddots &amp; \vdots \\ I_{n1} &amp; \cdots &amp; I_{nn} \end{bmatrix}  \end{equation*}   The errors I'm getting are related to missing $'s inserted. Are +1/+1 counters different from +1/+1 effects? Is a +1/+1 counter I get from, say Unleash or Undying different than +1/+1 from something like  or ? Why is my "Committed" memory so much higher than my actual RAM space? I have run two virus scans and neither of them have found anything so far (Malware Bytes and Avira Rescue). During gaming I will get Windows popups saying that my system is low of memory and recommends closing the game. This can also happen while browsing. My computer seems to become sluggish a lot and will hang up often, such as when clicking a link from a messenger program to open in my browser.   I am unsure what is causing this. My memory usage on the processes tab doesn't add up to such a high percentage of my actual memory.    As a side note, is my Disk Usage supposed to spike up to 100% sometimes? Research seems to say so. Compute $\lim_{x\to\infty}x\;\left[\left(1+\frac{1}{x}\right)^x-e\right]$ How can I compute the following limit, and is there a general method to resolve problems of this type?  $$\lim_{x\to\infty}x\left[\left(1+\frac{1}{x}\right)^x-e\right]$$ Which are safe and unsafe regions in Iran? Now there's a lot of propaganda in the west that leads us to believe Iran is dangerous and travellers shouldn't go there.  Obviously there are major political disagreements between several governments and the Iranian government and this should be taken into account.  But at a human level I have met many Iranians travelling elsewhere in the world and have found them to be friendly, charming, and hospitable. I have also met several western travellers who spent time in Iran, including hitchhiking around the country, who only have wonderful things to say about the country and its people.  As a traveller I've learned to trust the most what I hear from other travellers about a destination, especially ones which prefer similar ways of travel to myself. I've also learned to trust the opinions of inhabitants of countries bordering on the destination country the least.  Yet some people still insist that Iran is not safe for a traveller, or that .  I can look up for myself the general travel advisories issued by governments and disclaimers in WikiVoyage. So please don't regurgitate those an answers.  I want to know from travellers who've been there, from Iranians, or from references to specific incidents targeting foreigners/westers about which parts of Iran are no problem, and which parts should be avoided, even by experienced intrepid travellers.  (I realize any advice won't apply to Israeli citizens unfortunately. I'm Australian.) How do you find out which program is using too much memory? Ubuntu has been crashing on me recently. I think its because it runs out of memory so I ran the free -m command and found that my memory usage was really high. So then, i ran top to find the culprit, but the displayed processes were using less than 1.5% of memory. How do I know which program is making ubuntu crash/run out of memory? Below is the output:  shafee@shafee-pc:~$ free -m              total       used       free     shared    buffers     cached Mem:          3824       3714        110          0        978       1954 -/+ buffers/cache:        780       3044 Swap:           99          0         99  shafee@shafee-pc:~$ top top - 02:12:14 up  1:24,  2 users,  load average: 0.16, 0.42, 1.49 Tasks: 182 total,   1 running, 181 sleeping,   0 stopped,   0 zombie Cpu(s):  2.9%us,  1.9%sy,  0.3%ni, 79.3%id, 15.5%wa,  0.0%hi,  0.2%si,  0.0%st Mem:   3916708k total,  3803848k used,   112860k free,  1002308k buffers Swap:   102396k total,        0k used,   102396k free,  2001852k cached    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND              4200 root      20   0  289m  53m  38m S    2  1.4   1:06.45 Xorg                 5590 shafee    20   0 19348 1368  956 R    2  0.0   0:00.01 top                     1 root      20   0 24124 2136 1264 S    0  0.1   0:02.05 init                    2 root      20   0     0    0    0 S    0  0.0   0:00.00 kthreadd                3 root      20   0     0    0    0 S    0  0.0   0:24.23 ksoftirqd/0             6 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/0             7 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/1             9 root      20   0     0    0    0 S    0  0.0   0:00.11 ksoftirqd/1            11 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/2            13 root      20   0     0    0    0 S    0  0.0   0:03.89 ksoftirqd/2            14 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/3            16 root      20   0     0    0    0 S    0  0.0   0:00.16 ksoftirqd/3            17 root       0 -20     0    0    0 S    0  0.0   0:00.00 cpuset                 18 root       0 -20     0    0    0 S    0  0.0   0:00.00 khelper                19 root       0 -20     0    0    0 S    0  0.0   0:00.00 netns                  21 root      20   0     0    0    0 S    0  0.0   0:00.01 sync_supers         shafee@shafee-pc:~$   Or is it normal to have 110mb of free memory and is my issue related to something else? Crookshanks is Hermione's familiar in PoA, GoF, and OOTP. I cannot recall mention of Crookshanks following OOTP, though. What happened to Crookshanks? Does canon refer to Crookshanks in either HBP or DH? What is proper way to update D8 DEV? What's the deepest reason why QCD bound states have integer charge? What's the deepest reason why QCD bound states have integer electric charge, i.e. equal to an integer times the electron charge?  Given that the quarks have the fractional electric charges they do, this is a consequence of color confinement. The charges of the quarks are constrained in the context of the standard model by anomaly cancellation, and can be explained by grand unification. The GUT explanation for the charges doesn't care about the bound state spectrum of the QCD sector, so it just seems to be a coincidence that hadrons (which are composite) have integer charge, and that leptons (which are elementary) also have integer charge.   Now maybe there's some anthropic argument for why such a coincidence is useful (in the case of proton and electron, it gives us atoms as we know them). Or maybe you can argue that GUTs naturally produce fractionally charged particles and strongly coupled sectors, and it's just not much of a coincidence.   But I remain curious as to whether Seiberg duality, anyons, some UV/IR relationship... could really produce something like the lepton-hadron charge coincidence, for deeper reasons. I suppose one is looking for a theory in which properties of bound states in one sector have a direct and nontrivial relationship to properties of elementary states in another sector. Is there anything like this out there?   (This question was prompted by muster-mark's many recent questions about fractional charge, and by a  that the hadron-lepton charge coincidence is a "semi-coincidence", which assured me that I wasn't overlooking some obvious explanation.) Do you get Hex Warrior's Cha bonus with a two-handed Pact Weapon? Hex Warrior says:     you can touch one weapon with which you are proficient and that lacks the two-handed quality. When you attack with that weapon you can use your Charisma for attack and damage rolls.   later the ability says:     This benefit extends to every weapon conjured with the Pact of Blades feature, no matter the type.   (emphasis mine)  Does this allow me to use my charisma with 2 handed weapons(provided it is my Pact Weapon and my Hex Warrior Blade)?  This question is not the same as . That one is asking how many weapons, I'm asking if type means 2 handed or something else(Slashing or Ranged for examples).