Do gravitational waves lose energy through interaction with i.e. matter or magnetic fields? Gravitational waves dilute while traversing space like any other radiation, and their amplitudes are proportional to r-2, that's a basic. But do they lose energy while traversing through matter or something else (i.e. space with magnetic fields, or whatever), too, by interaction with it ?  (The question "Where does gravitational waves' energy go?" doesn't focus on traversing matter of fields)
Where does gravitational waves' energy go? Following the measurement of gravitational waves, many sources described them and explained they carry energy away. What I don't get is how this energy will get transfered back to anything else.  If the fabric of space-time itself is vibrating, it would seem to be in impossible for any physical object to gain this energy.    What am I missing?  How would one hypothetically get energy out of gravitational waves?  If impossible, does the universe end up with nothing but GW?
Sum of odd Fibonacci Numbers Trying to prove that the sum of odd-index consecutive Fibonacci numbers is the next even-index Fibonacci number. I have a gap in my proof that I cannot figure out. I know that induction would be easier and I have already done it that way, I am looking to use alpha and beta. $$\sum_{i=1}^n F_{2i-1} = F_{2n}$$  $$\begin{align*} \sum_{i=1}^n F_{2i-1}&amp;=\sum_{i=1}^1  \frac{1}{\sqrt{5}}(\alpha^{2i-1}-\beta^{2i-1})\\ &amp;=\frac{1}{\sqrt{5}}\left(\sum_{i=1}^1\alpha^{2i-1}-\sum_{i=1}^1\beta^{2i-1}\right)\\ &amp;\;\;\vdots\\ &amp;=\frac{1}{\sqrt{5}}[(\alpha^n-\beta^n)(\alpha^n+\beta^n)]\\ &amp;=\frac{1}{\sqrt{5}}(\alpha^{2n}-\beta^{2n})\\ &amp;=F_{2n} \end{align*}$$ Full List of inventory items After beating the game, I still have several empty inventory spots.  I most likely missed several items in my addicted frenzy to finish the game.  What are all the items that can be found in the game? And where can they found? Basically the question is how to get from this:   foo_id   foo_name 1        A 1        B 2        C   to this:   foo_id   foo_name 1        A B 2        C "be accorded someone" or "be accorded to someone"? When the verb accord means "give or grant", should the passive voice be accorded someone or accorded to someone?  I came across several sentences in a book:     The attention accorded husband-wife relations in Muslim teachings thus confirmed the indigenous view of matrimony as a desirable state, with the birth of children considered essential for the full attainment of adulthood.      Similar processes occurred in Daoism, which percolated into Vietnam from southern China but never received the official patronage accorded Confucianism.   Shouldn't it be "accorded to husband-wife relations", as "given to husband-wife relations"? Does Professor X have any responsibility for the state of the world? Throughout the course of Logan, it's obvious that Professor Xavier is having issues controlling his powers, and at the end of the movie, just before      X-24 kills him   he claims to "remember" what he did and expresses regret. We also hear about an incident in Westchester that killed several mutants, that sounds like Xavier may have been involved. Is Xaiver the reason there are no more mutants? Is that why he's sorry, because he knows he killed them all? I've got a generic dictionary Dictionary&lt;string, T&gt; that I would like to essentially make a Clone() of ..any suggestions. What are the differences between "=" and "<-" assignment operators in R? Custom Button on Lightning Experience I created a custom button Send Email in Lightning Experience. The problem is that button in visible in feed section layout, but I want to put it in the upper right corner of page layouts near Edit, Clone, Delete ecc....  How Can I do that? Thanks  I add an image that explain the situation.    EDIT: I would like to explain you better my problem.  I have created three custom quick action:   I have added them to the case page Layout as you can see    I would like to understand the reason why I don’t see these three custom action in the Page Layout in the section in the top right How do I remove directories that begin with a dot after my server was infected? My server had been infected and the attacker spread a bunch of .5randomletters folders around my file system, with malicious code inside of them. I want to search for all the folders that begin with a dot, review them and then remove them.  How can I do that? Word for a person being used I'm looking for a word to describe someone who is being used. I want a noun to describe this person, not a verb or or adjective.  Maybe like a pushover. Is there an (easy) way to create or personalize .bst files? When you prepare an article for a journal (in my case, Quantum Information and Computation, Rinton Press), often they ask you to use some format for your references; in my case, the following:     [1] R. Calderbank and P. Shor (1996), Good quantum error          correcting codes exist,  Phys. Rev. A, 54, pp. 1098-1106.      [2] M.A. Nielsen and J. Kempe (2001), Separable states   are  more disordered globally than locally, quant-ph/0105090.      [3] A.W. Marshall and I. Olkin (1979), Inequalities:   theory of majorization and its applications, Academic Press (New   York).   The issue is, sometimes (and this is the case) they do not provide a .bst style file for bibtex users. I (and I guess many other people) prefer not to copy all the references of a bibtex file one by one into a tex document. So here is the question I am trying to answer:     What is the easiest way to create a .bst file? (for Rinton or any other publisher)   At first sight, I thought this would be very easy to do: after all, a .bst file is just a mere script to give format to a list. Strangely to me, after a long search I have been unable to find a simple clean solution to this problem. These are the the options I have been looking at:   I have tried to adapt a previous .bst file: concretely, apsrev4-1.bst, which has a similar format. Other people have tried this solution before , . However, it is an ugly option. First, it requires going through the script of the .bst and understanding it. Second, the script format used in different .bst files differs (quite annoyingly), so it is not easy to modify them unless you do understand what's written. The above solution is quite hideous and you really lose time on it, so I was wondering: isn't there any software tool (hopefully with a GUI) that does this job? It should, after all, pretty easy to program for a .bst script expert some sort of program to generate .bst files. There are some related questions in this site asking for something similar , ; there I have seen a couple of proposed apps, but going through their manuals they seem not so easy to use. Isn't there some software tool available to generate a .bst in less than 1 hour of work?   Remarks: ideally I would like to use/personalize/create .bst styles that support eprint fields (e.g. aps4-1.bst). Why does inductor current lag the applied voltage at its terminal by 90 degrees? I studied electromagnetism and I am currently working with Inductors.  I could not figure out the physical reason based on electromagnetics on why inductor current lags the applied voltage by 90 degrees?  Everywhere I find the Formula as the starting point of explanation which is partially satisfying.    Induced EMF =L di(t)/dt    From the above equation, I understood that when there is a change in current there will EMF induced in the coil terminals. But How this induced EMF makes the current to lag the supply voltage V(t) = Vm*sin(wt)? (Please don't just differentiate and say there is a lag, I am looking for a physical sense on why this happens)  Lets us consider the AC voltage is applied across the terminal at time t=0; At this time there is almost no current. From this transient state how the steady-state is reached where the current is delayed with respect to the voltage?  Can someone help me to figure out why the current lags the Supplied voltage by using electromagnetism, the motion of Charges or any other basic concepts? Cancel misclicked flags How to create a grain / noise effect in Adobe Illustrator I want to create a noise effect using Adobe Illustrator.  Inside the hexagonal shape there is some kind of texture effect, I don't know what the name of this effect is:    How can I create such an effect in Adobe Illustrator? or is it created using Photoshop? Winter 18  does not get values from a parent record I am testing the new  &lt;lightning:datatable&gt;, it is really good, and is a good replacement for most of my use cases which today I use a custom list component that I have developed.  I am getting data from my server through apex method, to populate it into the &lt;lightning:datatable&gt; component. I can bind the returned list directly to the data attribute and if the column names are same as the field names, all data is bound correctly.  The problem occurs when I get data from a parent record. For example - I want the Account name of my contact.  This example can show the problem:  Component Markup    &lt;aura:handler name="init" value="{!this}" action="{!c.doInit}"/&gt;  &lt;aura:attribute name="mydata" type="Object"/&gt; &lt;aura:attribute name="mycolumns" type="List"/&gt; &lt;aura:attribute name="sortedBy" type="String"/&gt; &lt;aura:attribute name="sortedDirection" type="String"/&gt;  &lt;lightning:datatable data="{! v.mydata }"                      columns="{! v.mycolumns }"                      keyField="Id"                      onrowselection="{! c.getSelectedName }"                      onsort="{!c.updateColumnSorting}"                      sortedBy="{!v.sortedBy}"                      sortedDirection="{!v.sortedDirection}"                      hideCheckboxColumn="{!false}" /&gt;        Component Controller  ({     doInit: function (component, event, helper) {         component.set('v.mycolumns', [                     {label: 'Id', fieldName: 'Id', type: 'id', sortable:"true"},                     {label: 'First Name', fieldName: 'FirstName', type: 'text', sortable:"true"},                     {label: 'Last Name', fieldName: 'LastName', type: 'text', sortable:"true"},                     {label: 'First Name Hebrew', fieldName: 'First_name_Hebrew__c', type: 'text', sortable:"true"},                     {label: 'Last Name Hebrew', fieldName: 'Last_name_Hebrew__c', type: 'text', sortable:"true"},                     {label: 'Account', fieldName: 'Account.Name', type: 'text', sortable:"true"},                     {label: 'Email', fieldName: 'Email', type: 'email', sortable:"true"},                     {label: 'Phone', fieldName: 'Phone', type: 'phone', sortable:"true"}                 ]);          var action = component.get("c.getRecordsFromDb");         action.setParams({             sObjectName: "Contact",             commaDelimitedFieldNames: "Id,FirstName,LastName,First_name_Hebrew__c,Last_name_Hebrew__c,Account.Name,Email,Phone",             filter: ""         });         action.setCallback(this, function(response){             var state = response.getState();             if (component.isValid() &amp;&amp; state === "SUCCESS") {                 var data = response.getReturnValue();                  component.set("v.mydata", data);             }         });         $A.enqueueAction(action);     } })   APEX Aura Enabled Method  @AuraEnabled public static List&lt;sObject&gt; getRecordsFromDb(String sObjectName,         String commaDelimitedFieldNames,         String filter) {      system.debug('\n\n\n\ngetRecordsFromDb sObjectName: ' + sObjectName + ', commaDelimitedFieldNames: ' + commaDelimitedFieldNames + ', filter: ' + filter + '\n\n\n\n');      // create a dynamic soql to get the value of the field     String sql = 'SELECT ' + commaDelimitedFieldNames + ' FROM ' + sObjectName;      if (!String.isBlank(filter))         sql += ' WHERE ' + filter;      system.debug('\n\n\n\ngetRecordsFromDb sql: ' + sql + '\n\n\n\n');     List&lt;sObject&gt; records = Database.query(sql);     system.debug('\n\n\n\ngetRecordsFromDb: ' + records + '\n\n\n\n');      return records; }   The problem is with the Account.Name field - the &lt;lightning:datatable&gt; component does not display the column data.   I know that the data is returned ok, and I know that in the object that is returned, the Account is contained like an object (probably this is the problem):    Is there a good way to show parent record data with this component? Is there a way to block a list of specific apps on macOS?  I have looked up solutions such as Cisdem, but there are some holes in the way it works that I don't like.   Unless you also block Activity Monitor, Terminal, and System Preferences, you can simply quit the Cisdem process or create a new user to get around it. You have to block Activity Monitor, Terminal, and System Preferences to make it work well.   I want to block an app from running or even being installed on my Mac. The app can be installed via the App Store and the web. Not sure how to go about this. Enabling Parental Controls won't work as Administrator privileges are needed.   The specific app I want to block is Apple Configurator.  Any ideas? Why does triply periodic univariate function not exist? A univariate function $f$ is periodic with period $p_1,\ldots,p_k$ if   $$f(z) = f(z + \sum_{i=1}^k n_i \cdot p_i)$$   for all complex $z$ and integers $n_i$. Elliptic function is an example of doubly periodic function.  that a triply periodic univariate function cannot exist, but why? Can't we follow the construction of elliptic functions that uses Schwarz-Christoffel formula to map upper-plane onto a triangle, and use the reflection principle to create a lattice which corresponds to three periods?     Which step fails to hold when we mimic the construction of an elliptic function to create a triply period meromorphic univariate function?   Sorry if the question is stupid. I do not have an access to the original proof that a triply periodic function cannot exist, either. So references are welcome! C# Interfaces. Implicit implementation versus Explicit implementation What are the differences in implementing interfaces implicitly and explicitly in C#?  When should you use implicit and when should you use explicit?  Are there any pros and/or cons to one or the other?    Microsoft's official guidelines (from first edition ) states that using explicit implementations are not recommended, since it gives the code unexpected behaviour.  I think this guideline is very valid in a pre-IoC-time, when you don't pass things around as interfaces.  Could anyone touch on that aspect as well? How do I animate time? "By" vs "Per". Which one should I use on expressions like "P&L/Geography" or "VaR/Asset"? In the finance field, it is quite common to express some measures in relation to some grouping criteria. Some groupings can be temporal (year, month, etc.) and others like greography, asset class (e.g. a financial product), strategy (used in trading), and others.   Which one is the most appropriate preposition to apply in this kind of expression ?    "VaR per asset" or "VaR by asset" "P&amp;L per strategy" or "P&amp;L by strategy".   Is there any well defined rule behind the most appropriate use ?