I have searched the C: drive exhaustively for any/all image files and I do find a few screensaver images, but not the ones that appear most often (or the ones I am interested in saving). I am guessing these missing screensaver images get downloaded over the internet and never get stored on the C: drive. Where do these Windows 2010 screensaver images come from? Are they stored on my machine anywhere?
Where are the images from  coming from?  Where are they being saved on my system?  Is there any way for me to point this at my own source of images?
I am pretty sure $(B_{t}^{2})$ not Markov because the squared random walk is not.    I guess I can repeat the method since to be Markov it must satisfy the discrete.  Thanks A commutative ring is a field iff the only ideals are $(0)$ and $(1)$ Let $R$ be a commutative ring with identity. Show that $R$ is a field if and only if the only ideals of $R$ are $R$ itself and the zero ideal $(0)$.  I can't figure out where to start other that I need to prove some biconditional statement. Any help? Should a retrieval method return 'null' or throw an exception when it can't produce the return value? I am getting this error:     SObject row was retrieved via SOQL without querying the requested   field: Contact.Account   Controller:  public class WrapperAccountCtrl {      public List&lt;Account&gt; acclist{get;set;}     public List&lt;Contact&gt; conlist{get;set;}      public List&lt;MyWrapper&gt; wap{get;set;}      public WrapperAccountCtrl()      {         acclist=[Select id,name from Account];          conlist=[Select id,name,AccountID  from contact where AccountID IN:acclist];          system.debug('Size----'+conlist.size());           wap=new List&lt;MyWrapper&gt;();           for(integer i=0;i&lt;acclist.size();i++)          {              wap.add(new MyWrapper(conlist,acclist[i]));          }     }      public class MyWrapper     {          public Account accn{get;set;}          public List&lt;Contact&gt;conrec{get;set;}          public MyWrapper(List&lt;Contact&gt; con,Account acc)         {             accn=acc;             conrec=con;             }     } }   VF Page:  &lt;apex:page controller="WrapperAccountCtrl" sidebar="false"&gt;       &lt;apex:form &gt;          &lt;apex:pageBlock &gt;              &lt;apex:pageBlockTable value="{!conlist}" var="c"&gt;                  &lt;apex:column value="{!c.account.Name}"/&gt;              &lt;/apex:pageBlockTable&gt;          &lt;/apex:pageBlock&gt;      &lt;/apex:form&gt;  &lt;/apex:page&gt; Baby Rudin claim: $1+\frac{1}{3}-\frac{1}{2}+\frac{1}{5}+\frac{1}{7}-\frac{1}{4}+\frac{1}{9}+\frac{1}{11}-\frac{1}{6}...$ converges This sequence is a rearrangement of the series $1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}...$. Note that at this point in the text we do not have any theorem about the convergence of rearrangements.  Let $\{s_n\}$ be the sequence of partials sums of the series then for $n \ge 0$  $s_{3(n+1)} = \sum ^n _ {k=0} \frac{1}{4k+1} + \frac{1}{4k+3} - \frac{2}{4k+4}$  We can view it as the sequence(on $n$) of partials sums of  $\sum_0 a_n = \sum_0 \frac{1}{4n+1} + \frac{1}{4n+3} - \frac{2}{4n+4}$  Where $|a_n| = a_n = \frac{1}{4n+4}\{\frac{3}{4n+1}+\frac{1}{4n+3}\} \le \frac{1}{4n^2}$.  By the comparison test $s_{3(n+1)}$ converges to some real $\alpha$.  But $s_{3(n+1)+1} = s_{3(n+1)}+ \frac{1}{4n+5}$ and $s_{3(n+1)+2} = s_{3(n+1)}+ \frac{1}{4n+5}+\frac{1}{4n+7} $hence we have a partition of $\{s_n\}$ into subsequences which tend to $\alpha$ and this implies $s_n \rightarrow \alpha$.  Is my proof correct? Any alternative solutions are appreciated. Please add TeX rendering on the Android app MathJax isn't currently working on the Android app, which makes it totally useless for the 'technical' sites like  or .  For example, in the Android app:    Same post in a (mobile) browser:     Please add this functionality! I would like to put an address in my document as follows:  |                             | |                     Name    | |                     Street #| |                     City    | |                     ZIP     | |                             |   where the | mark the left and right page borders. I would like the items of the address (Name, Street etc.) to be left-flushed, but the box right-flushed so that the longest item touches the right page border.  Is there a simple way to accomplish this? Powers of infinite cardinals in the generic extension Log and natural log Why can't I move a window to the top left corner with wmctrl in Unity? I've been playing around with wmctrl to take more control of my windows. I've encountered a weird behaviour where Unity reserves double the space. See this screen shot:    I opened the terminal and moved the window using the top command. It should be at the top left corner (X=0 Y=0). But for some reason there is some margin between the terminal and the Unity bars.  If I understand the man pages correctly it might have something to do with the WA: 65,24.  Can anybody help me to fix this? Under what conditions is the exponential map on a Lie algebra injective? Let $G$ be a Lie group with Lie algebra $\mathfrak{g}$ and let $\exp :\mathfrak{g}\rightarrow G$ be the exponential map.  In his blog,  that if a Lie group is not simply-connected, then $\exp$ will not be injective.  Conversely, is it true that if a Lie group is simply-connected, then $\exp$ is injective?  If not, what is a counter-example? Interpretation of interaction term Anyone ever seen a "wok adapter" for induction cooktops? In theory a cheap pressed steel wok would work on an , but the "contact patch" for a traditional round bottomed wok would be so small it would be ineffective.  Has anyone seen a steel or cast-iron "wok adapter" with a flat bottom and a concave "bowl" on top to sit the wok in, serving dual purposes of supporting the wok on the stovetop and transferring the induction heat to the wok?  Could anyone speculate if this would this even work? Or wouldn't you be able to get the wok hot enough? I'm taking an electronic circuit analysis class, and I was asked to give the color of the 3rd band of a 1MΩ resistor. My answer was blue, thinking it could be black-brown-blue (01 * 1MΩ), but the automated quiz said the correct answer was green (brown-black-green).  So I did some research, thinking there were just multiple correct answers, and I read in a few places that the first band on a resistor is never black (0). Why is this? Does a black first band have some other meaning? It would really help me remember it if I knew the history or reasoning behind it.  This question has been answered. For further reading on zero-ohm resistors mentioned in the answers and comments here, I found these questions and answers helpful: Normalizing constant in Bayes theorem I read that in Bayes rule, the denominator $\Pr(\textrm{data})$ of   $$\Pr(\text{parameters} \mid \text{data}) = \frac{\Pr(\textrm{data} \mid \textrm{parameters}) \Pr(\text{parameters})}{\Pr(\text{data})}$$   is called a normalizing constant. What exactly is it? What is its purpose? Why does it look like $\Pr(data)$? Why doesn't it depend on the parameters? How to have separated but vinculated multiple Ubuntu One accounts? Does existence of magnetic monopole break covariant form of Maxwell’s equations for potentials? Absence of magnetic charges is reflected in one of Maxwell's fundamental equations: $$\operatorname{div} \vec B = 0. \tag1$$ This equation allows us to introducte concept of vector potential: $$\vec B = \operatorname{rot} \vec A.$$ Using this concept, it is possible to express Maxwell's equations in a graceful symmetric form: $$\nabla^2 \vec A - \frac{1}{c^2}\frac{\partial^2 \vec A}{\partial t^2} = - \frac{\vec j}{\epsilon_0 c^2}, \tag2$$ $$ \nabla^2 \phi -\frac{1}{c^2}\frac{\partial^2 \phi}{\partial t^2} = - \frac{\rho}{\epsilon_0}. \tag3 $$  Noticing, that vector $\vec A$ and scalar $\phi$ potentials, as well as electric current density $\vec j$ and charge density $\rho$, form a 4-vector in Minkovsky space-time. Therefore, Maxwell's equations can be expressed in a covariant form, using d'Alembertian: $$\nabla_{\mu}\nabla^{\mu} A_{\nu} = \frac{j_{\nu}}{\epsilon_0}. \tag4$$  If magnetic monopols exist, Maxwell's equation $(1)$ will look as: $$\operatorname{div} \vec B = \mu_0 c \rho_{\mathrm{magnet}}.$$  As the divergence of $\vec{B}$ isn't equal to zero, it impossible to introduce concept of vector potential. Thus, the equation in the form of $(4)$ will not be possible to express. What is the typical post processing work flow for amateur photographers? I love photography; I hate postprocessing.  Seeing that I am an amateur, not just by virtue of not getting paid for it, but also being rather new to the whole affair, I already am used to most of my shots just not being that great. While reading blogs and websites I get the impression that condensing ~100 frames in maybe a handful of shareworthy photos is not rare.  But even so, after a vacation quite a few photos have accrued. What is a common workflow to sort, post-process and share photographs for a beginner? What are common postprocessing steps? What kind of automations do people use?    Edit: I phrased the question generically so that it can be of use to as many people as possible. But I understand that without anything to go by, it might be a bit hard to answer. Therefore, while I own no paid-for software, this is what I use:   I have an EOS 500D crop camera as picture source and I use  for development,  for any touching up I need to do. (Which is not much, so far.)  (in a VM) is my photo catalog. My destination is my Flickr stream for the most part, sometimes I send photos directly to family and friends.   On the input side, I mostly am in practice mode; shooting whatever I can place in front of my lens. I have not yet picked a specialty. I would like to minimize time spent fine-tuning photos in software. These sort of "batch processes" are a part I realize is important, but not much fun to me.  I am quite computer-literate, so I am not afraid of piecing together tools that can be of use, but the more "" this can be, the more people who don't spend their life in front of a PC can benefit too. :) If spending money on something will make my life easier, I am quite willing to consider it. However as photography does not bring any income, something as large as Photoshop (for example) is somewhat hard to justify as an investment. Deleting (Erasing) all Data from Failed SanDisk MicroSD Card I've had two 32GB SanDisk MicroSD cards go bad recently.  One I was able to temporarily revive using the kind advice offered in this thread:   When I insert the other into a reader, it registers as 30.6MB (that's MB, not GB).  I've tried all sorts of software and other techniques to revive this card and retrieve the important data off of it (including FindAndMount and TestDisk).  Nothing has worked.  So I'm thinking of returning the card for a refund.  But first, I would like to make it unreadable by someone more skilled than myself.  Is there any way to do this, given that I cannot even format the card or get it to be recognized as more than 30.6MB?  I am looking for a method that does not entail the kind of obvious physical destruction that would jeopardize obtaining a refund from the retailer.  If Costco (where the card was purchased) accepts physically destroyed cards for return, then physical destruction is acceptable (but please have knowledge that they do).  Given two failures, I don't really want to send the card to SanDisk for replacement, because I no longer trust the reliability of their products. How can I make sure texts from friends with iPhones don't go to iMessage instead of my Android phone? I have always used an Android phone, but text messages from certain friends get hijacked by iMessage. How do I prevent iPhones and MacOS Messages from sending me iMessages? I need all messages to be SMS or MMS. Some friends with iPhones will text me, but I don't receive the message. Today I noticed the Message app on my Mac had notifications. I never open this app since I don't use iMessage, but I looked today, and found multiple &quot;lost&quot; messages from several weeks ago. Please note that this is NOT the same question as . My Android phone is not, and has never been, registered with iMessage, and I have already followed those instructions. Another poster () had the same question as me----but it was closed, being deemed as the same as the Removing phone number question. It's actually fairly different. I have tried:  Leaving my Messages app closed on my Mac. But somehow messages from these people get hijacked. Deregistering my mobile number using Apple's online Deregister iMessage tool. When I attempted this, I got the message &quot;Your phone number is not registered with iMessage.&quot; Finding a setting on my Android phone that addresses this. The problem is apparently (and logically seems to be) on the Apple end.  Things  says he tried:   Closing Messages.app. I still get macOS notifications of messages. In Messages &gt; Preferences… &gt; Accounts &gt; [my email address], untick &quot;Enable this account&quot;. Then my friends messages disappear and I never see them at all, at least until I reenable in Messages.app. Looking in System Preferences and on icloud.com and appleid.apple.com    to see if there is some setting I can disable—but I've not found    anything relevant. Using Apple's Deregister iMessage tool to unregister my mobile    number. When I attempted this it gave me the message &quot;Your phone number is not registered with iMessage.&quot;