I think this has happen by some natural disasters like storms, droughts, fires, encroaching, and the seas taking over our land.
So the stories of the Hunger Games are set in , a post-apocalyptic society situated in North America. Is there anything to explain what caused the Apocalypse? Whether from the main books, any extra material or interviews? (No fanfic please.)  As well as the cause, is there any indication of when the apocalypse happened? And how long after the apocalypse are the events of the Hunger Games?
Place each foot on a scale: can you add the two to find your weight? I frequent a blog from a British psychologist, and every Friday he likes to pose an interesting puzzle or riddle. The Monday after that he posts the answer. They're good fun, and IANAP but  made my it-might-not-be-quite-as-simple-as-that detector go off.  My question boils down to this: let's say I have two identical scales, and I stand on the scales with one foot on each scale. The scales read W1 and W2. Does my weight equal W1 + W2? How to generate a random alpha-numeric string How do I exactly find the zero divisors and units of a ring in the form of $\mathbb{Z}_n \times \mathbb{Z}_m$? For instance, how does one calculate zero divisors and units of $\mathbb{Z}_6 \times \mathbb{Z}_2$? I understand that a zero divisor is a non-zero element of $R$ such that $rs = 0$ for some other non-zero element $s$ in $R$. But I don't really quite understand how to apply that to a ring of the form $\mathbb{Z}_n \times \mathbb{Z}_m$. Also, the units of $\mathbb{Z}_6 \times \mathbb{Z}_2$ would be elements that send some element $s$ in $\mathbb{Z}_n \times \mathbb{Z}_m$ to the multiplicative identity, right? (which would be 1)? How do I apply these concepts to "product" rings? Thank you. How can I find a mentor to critique my work? Why exactly do sometimes universal covers, and sometimes central extensions feature in the application of a symmetry group to quantum physics? There seem to be two different things one must consider when representing a symmetry group in quantum mechanics:   The universal cover: For instance, when representing the rotation group $\mathrm{SO}(3)$, it turns out that one must allow also $\mathrm{SU}(2)$ representations, since the negative sign a "$2\pi$ rotation" induces in $\mathrm{SU}(2)$ is an overall phase that doesn't change the physics. Equivalently, all representations of the Lie algebra are what we seek. ($\mathfrak{so}(3) = \mathfrak{su}(2)$, but although every representation of the algebra is one of the universal cover, not every representation of the algebra is one of $\mathrm{SO}(3)$.) Central extensions: In conformal field theory, one has classically the  of infinitesimal conformal transformations. From the universal cover treatment one is used to in most other cases, one would expect nothing changes in the quantum case, since we are already seeking only representation of an algebra. Nevertheless, in the quantization process, a  appears, which is often interpreted to arise as an "ordering constant" for the now no longer commuting fields, and we have to consider the  instead.   The question is: What is going on here? Is there a way to explain both the appearence of universal covers and central extensions in a unified way? Using RegEX To Prefix And Append In Notepad++ I have quite a large list of words in a txt file and I'm trying to do a regex find and replace in Notepad++. I need to add a string before each line and after each line.. So that:   wordone wordtwo wordthree   become   able:"wordone" able:"wordtwo" able:"wordthree"   How can I do this? Can we divide two vector quantities? For eg., Pressure( a scalar) equals force (a vector) divided by area (a vector). Regarding the recalc in question rep increase what happens due to the cap? When the recalc runs what happens regarding rep capping on particular days? Say I earned 200 solely from questions on one day, will I earn a further 200 when the recalc runs or will I earn zero?  On a similar note if I got no rep from a question upvote on a day will the recalc give me 10, 5 or 0 rep? Write a number with two decimal places SQL Server apt-get build-dep is unable to find a source package On per-site metas, users are given a rank based on meta participation, and this ranking is seen on the default tab of the users page on each per-site meta. How is this participation numerically calculated to give a ranking? Is it by votes? Something else? Are community wiki posts included in this? ‘[...][Harry'll] be famous – a legend – I wouldn’t be surprised if today was known as Harry Potter Day in future – there will be books written about Harry – every child in our world will know his name!’   ‘Exactly,’ said Dumbledore, looking very seriously over the top of his half-moon glasses. ‘It would be enough to turn any boy’s head. Famous before he can walk and talk! Famous for something he won’t even remember! Can’t you see how much better off he’ll be, growing up away from all that until he’s ready to take it?’   Philosopher's Stone - pages 15 - 16 - chapter one, The Boy Who Lived   Did Dumbledore choose correctly?  Knowing what we do about Harry and his canon character attributes (And faults, too!), was Harry really better off enduring eleven years of physical and emotional abuse at the hands of the Dursleys than eleven years of celebrity and fame in the wizarding world? I'm sure we've all read about child celebrities who have done well handling fame, and some who have not fared so gracefully.   Would Harry have endured celebrity as stoically as he did the Dursleys' abuse? Did Dumbledore make the right choice in leaving Harry with the Dursleys instead of letting him grow up in the wizarding world?  Was Harry really better off?  ETA: I'm looking for an answer grounded in Harry Potter canon and written in the spirit of canon. Please do not pair Harry with Elle Fanning or opine that he's secretly an American ;) Thanks! Mcrypt extension is missing in 14.04 server for mysql The php mcrypt extension on ubuntu 14.04 shows that it is installed properly, but phpmyadmin says:   The mcrypt extension is missing. Please check your PHP configuration.   My current php config is . If you need anymore information, please contact me through the comments.  $ sudo apt-get install php5-mcrypt     Reading package lists... Done     Building dependency tree            Reading state information... Done     php5-mcrypt is already the newest version.     0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. How should I deal with becoming discouraged as a graduate student? I am a third year (starting fourth year in the fall) PhD student in mathematics. I've passed all qualifying exams and am currently doing research. As far as I can tell, I am not doing poorly. I have the good fortune of having a great advisor, being in a very supportive department, and having friends and family who genuinely care about my success.   The fact is research is hard. It appears to consist primarily of staring at a problem for days and days and days without getting anywhere. Sometimes, rarely, I do figure something out and that feels wonderful, but the overwhelming majority of my time appears to be spent banging my head against a mostly figurative wall. I am not complaining about the material being hard, and I am not averse to putting in hard work, but I get frequently discouraged when I realize the vast volumes of mathematics that I yet know nothing about (and probably never will). It's very hard to quantify progress - in particular, there are too few tangible returns after too many hours worked. I find myself thinking along the lines of "Oh, if only someone actually smart were thinking about this problem they would have solved it in moments" and so on.   I've talked about this to some number of people; here is some advice I have received:   Take a day off. Putting in hours upon hours of trying things doesn't magically lead to a solution, particularly if the brain is tired and just wants to sleep. Have a hobby. Since math research doesn't exactly provide instant gratification, a hobby might provide some instead.  Talk to other graduate students. Realize that many graduate students go through this.   I'm interested to know how other folks have dealt with being discouraged as a graduate student. Does it get better with time and experience? Is this a sign that research is not for me and that I should seriously consider a life outside academia? I'm using post thumbnails to link to a page.  Is it possible to add a class name to the post thumbnail image.  &lt;li&gt;&lt;a href="&lt;?php the_permalink(); ?&gt;" &gt;&lt;?php the_post_thumbnail(); ?&gt;&lt;/a&gt;&lt;/li&gt; Bread and butter is/are my breakfast? Bread and butter (is or are) my breakfast?  And what's the difference between the above sentence and saying "My breakfast is bread and butter"?  Thanks. How can the Xenomorph see? If you just look at a picture of one there are no eyes readily apparent but they clearly know where they are going. Could their screeching be some form of echo-location? Childrens fantasy, blind monk leading boy who can control the elements Evaluating $\int_0^{2 \pi} e^{\cos x} \cos (nx - \sin x) \,dx$ using complex analysis I'm taking a complex analysis course and doing some practice computing residues &amp; evaluating integrals. I pulled out an old book called     On page 196-197, there are some interesting integrals to evaluate. I'm at 5.4.3.10.: I was able to do question 1, but was stumped at how to even begin with question 2:     Evaluate the integral   $$\int_0^{2 \pi} e^{\cos x} \cos (nx - \sin x) \,dx ,$$   where $n$ is an natural number.   The answer is simply $\frac{2 \pi}{n}$. Any hints? Can I use my familiar to cast Warding Bond on myself? Find Familiar lets you cast touch spells through your familiar. Warding Bond is a Touch spell, that creates a connection between "you and the target". I can't find anything against it, but would it be possible to have my Wizard make his familiar cast Warding Bond on the Wizard himself, so that the Wizard gets the +1 to AC and saving throws and resistance to damage?  I realized after I wrote this much that Wizards don't get Warding Bond, but I think the question is still valid for multiclassers.