Trying to recall series of novels set in palaeolithic Europe with time travel from near present
Book series about time travel from future to distant past, psychic powers?
Can FFMPEG extract images from a video with timestamps? Redirect a portion of a bash script to a file to capture set -x output Should questions include "tags" in their titles? I've seen questions edited to remove the language name from the title. Won't search engines - and folks using search engines - have an easier time finding them if these "tags" are kept as part of the title? How to create immutable objects in Java? Bash is not finding a program even though it's on my path How do I handle collision detection so fast objects are not allowed to pass through walls? I'm creating a 2d sidescrolling shooter, and I'm having a little trouble with collision detection for the bullets. Everything including the bullets are objects with their own polygons / update methods.  The trouble is that bullets go fast, and at 60 frames per second (what the game runs at) a bullet will often skip right through a wall -- since it moves more than the width of the wall during in the update interval -- and continue happily on its way since the polygons will never actually overlap.  What can I do about this? The only thing I've been able to come up with is to draw a line from the old position to the new position and do collision detection on that, but line drawing for collision detection is recommended against by the slick2d documentation. How can I solve this? Prove that there exist two integers such that i - j is divisible by n. Here's the full question:  Prove that, for any $n + 1$ integers, $\{x_0, x_1, x_2, . . . , x_n\}$, there exist two integers $x_i$ and $x_j$ with $i \neq j$ such that $x_i − x_j$ is divisible by $n$.  Now, the integers aren't necessarily consecutive, positive, or without repeats. I've tried breaking this into cases, such as "$x_i = x_j, \dfrac{0}{n} = 0$" etc. But I don't think it's possible to exhaust the cases.  I feel like there should be an easy way to contradict this one, by saying that $x_i - x_j$ isn't divisible by $n$. But I just wasn't getting anywhere with that one.  I thought about using induction, but I would have just as hard a time proving this for $n$ integers before $n+1$ integers, so I don't think it would be possible for me to do it that way.  If anyone could help out, that would be wonderful. I'm pretty stuck here. Slit screen and wave-particle duality In a double-slit experiment, interference patterns are shown when light passes through the slits and illuminate the screen. So the question is, if one shoots a single photon, does the screen show interference pattern? Or does the screen show only one location that the single photon particle is at? Benefit of date in URL segments I was curious about the date in URL segments, is there any SEO point of benefit? For example the following URLs:  http://techcrunch.com/2013/06/18/netflix-will-launch-in-the-netherlands-later-this-year-as-its-international-expansion-slows/ http://tips-for-new-bloggers.blogspot.in/2007/02/adding-favicon-icon-to-blogger-url.html  https://community.jivesoftware.com/blogs/jivespace/2013/05/15/eol-of-the-html5-ipad-web-app   In all the above URLs there is date segment. The information of those blogs can be fetched via blog stub like "netflix-will-launch-in-the-netherlands-later-this-year-as-its-international-expansion-slows" so why to use that date part? C99 stdint.h header and MS Visual Studio Every planar graph has a vertex of degree at most 5. I am trying to prove the following statement, any help!?     Prove that every planar graph has a vertex of degree at most 5. Is there a HTML opposite to ? Is there a tag in HTML that will only display its content if JavaScript is enabled? I know &lt;noscript&gt; works the opposite way around, displaying its HTML content when JavaScript is turned off. But I would like to only display a form on a site if JavaScript is available, telling them why they can't use the form if they don't have it.  The only way I know how to do this is with the document.write(); method in a script tag, and it seems a bit messy for large amounts of HTML. If $p\in\Bbb Z[X]$ show that: $ \max\limits_{x\in [0,1]}\left|p(x) \right| > \frac{1}{e^{n}}. $ This is problem 10 from the International Mathematical Competition for University Students of 2015, from day 2, in Bulgaria. I think it is an interesting problem!     Let $n$ be a positive integer, and $p(x)$ be a polynomial of degree $n$ with integer coefficients. Prove that   $$ \max_{x\in [0,1]}\left|p(x) \right| &gt; \frac{1}{e^{n}}. $$   Proposed by Géza Kós, Eötvös University, Budapest. I had one batch class in which i am passing some data required for creating object record.But when i call that batch class from parent class variables are initialized but start method are not called as there is no record to query i also tried with iterable object but not able to do that.My code is as below  global class testBatchClass implements Database.Batchable&lt;SObject&gt;,Database.Stateful{     public List&lt;sObject&gt; sObjectList;     public string objectName;     public String dataList;      public testBatchClass(String objectName,String inputdata){          String listType = 'List&lt;'+objectName+'&gt;';         system.debug('list type value is'+listType);         List&lt;SObject&gt; castRecords = (List&lt;SObject&gt;)Type.forName(listType).newInstance();         this.sObjectList = castRecords;         this.objectName = objectName;         this.dataList = inputdata;      }     global Iterable&lt;SObject&gt; start(Database.BatchableContext batchableContext) {         return new sObjectList{};     }     global void execute(Database.BatchableContext batchableContext, List&lt;sobject&gt; scope){          List&lt;OpportunityRenewal__mdt&gt; mdtList = new List&lt;OpportunityRenewal__mdt&gt;([Select id,Api_Name_of_Fields__c,Sobject_Name__c from TestFileUploadCustomSetting1__mdt where Sobject_Name__c=:objectName]);         List&lt;String&gt; fieldName = new List&lt;String&gt;();         for(OpportunityRenewal__mdt md : mdtList){             if(md.Sobject_Name__c == objectName){                 fieldName = md.Api_Name_of_Fields__c.Split(',');                 break;             }         }         List&lt;String&gt; dataRowsSplit= dataList.split(',');         dataRowsSplit.remove(0);         for(String eachRow: dataRowsSplit){             List&lt;String&gt; splitString = eachRow.Split(',');             sObject sobj = Schema.getGlobalDescribe().get(objectName).newSObject();             for(Integer i=0; i &lt;= splitString.Size(); i++){                 sobj.put(fieldName[i],splitString[i]);             }             scope.add(sobj);         }         if(scope != Null &amp;&amp; scope.Size() &gt; 0){             upsert scope;         }     }      global void finish(Database.BatchableContext batchableContext) {} }   Thanks Is there a way to increase space between bibliography without using biblatex? Problems installing xpatch I need to install the xpatch package to make changes to my biblatex setup. The readme file in the install package simply says to run “latex xpatch.ins.” I've moved the xpatch folder (including xpatch.ins and xpatch.dtx files) to the /usr/local/texlive/2011/../texmf-local/ folder. When I run the command above, I get the output Generating file(s) ./xpatch.sty  ! Cannot find file xpatch.dtx. \readsource ...ot find file \uptospace #1 \qStop }                                                   \else \processedLines \z@ ... l.34 ...xpatch.sty} {\from{xpatch.dtx} {package}}}   I've checked, and the .dtx file is in the folder. Any ideas what the problem is? using System; using System.Security.Permissions; using Microsoft.SharePoint; using Microsoft.SharePoint.Security; using Microsoft.SharePoint.Utilities; using Microsoft.SharePoint.Workflow;  namespace Change_Title_Event.Change_Title {     /// &lt;summary&gt;     /// List Item Events     /// &lt;/summary&gt;     public class Change_Title : SPItemEventReceiver     {        /// &lt;summary&gt;        /// An item is being added.        /// &lt;/summary&gt;        public override void ItemAdding(SPItemEventProperties properties)        {            properties.AfterProperties["Title"] = "Kevin: Changed by event receiver at" + DateTime.Now.TimeOfDay.ToString();            base.ItemAdding(properties);        }       } }   Where simple example, which works perfect on my local Sharepoint 2010. It is sandboxed.  But when I package this solution, it do not work on Sharepoint Online. I does not give any Errors either.  I think I am doing something wrong, something simple, but I can't simply find anything on Google about it.  Here is another who asks on the MSDN forum, but gets a very wierd reply, that I do not understand. What communication can be intercepted by network I'm connected over VPN to? I have to connect to client's network over VPN, and I was wondering if the client can intercept (and read) my Google Talk messages (or any other IM communication) while I'm VPN-ing.  My main concern is them having access to our internal conversations.  Suggest workarounds if you have any. Proving $\sum\limits_{i=1}^k | \langle x,v_i \rangle \langle y,v_i\rangle| \leq \|x\|\cdot \|y\|$ Let $V$ be a real inner product space, and let $v_1,v_2, \dots ,v_k$ be an orthonormal set of vectors. How do you prove that  $$\sum_{i=1}^k | \langle x,v_i \rangle \langle y,v_i\rangle| \leq \|x\|\cdot\|y\|?$$  When does the equality hold?  I've been trying to do this with the Bessel and Cauchy-Schwarz inequalities, but I can't make it work yet. Any help would be greatly appreciated. Understanding Python super() with __init__() methods I'm trying to understand the use of super(). From the looks of it, both child classes can be created, just fine.   I'm curious to know about the actual difference between the following 2 child classes.  class Base(object):     def __init__(self):         print "Base created"  class ChildA(Base):     def __init__(self):         Base.__init__(self)  class ChildB(Base):     def __init__(self):         super(ChildB, self).__init__()  ChildA()  ChildB()