LIGO have detected gravitational waves, why we are still far away from detecting gravitations?  how to understand the statement below?     A classical wave may be considered to be a coherent   superposition of a large number of gravitons.
With the announcement of the detection of gravitational waves, questions about the implications proliferate.  Some relate to the possible existence of gravitons.  The analogous relationship between gravitons/gravitational waves and photons/electromagnetic waves is frequently mentioned.  The detection of individual photons required experiments of very low intensity light, yet their existence was inferred (prior to their actual detection) by Planck and Einstein (among others) using the properties of experimental black body radiation and the photo-electric effect.  If the prospects for detection of gravitons requires similar study of very low intensity gravitational waves, then those prospects are very dim indeed. My question: are there similar indirect "experimental" methods for inferring the existence of gravitons?
Ever since I upgraded to 15.10, fdisk -l reports 16 ram disks (/dev/ram0 ... /dev/ram15). I'm a bit unsure what those are needed for. Is it safe to delete them? If not, how can I get rid of that fdisk output? Do not delete good duplicates! How to send variable to an inline shell-script? Java Interface Usage Guidelines -- Are getters and setters in an interface bad? Winforms issue - Error creating window handle We are seeing this error in a Winform application.  Can anyone help on why you would see this error, and more importantly how to fix it or avoid it from happening.   System.ComponentModel.Win32Exception: Error creating window handle.    at System.Windows.Forms.NativeWindow.CreateHandle(CreateParams cp)    at System.Windows.Forms.Control.CreateHandle()    at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)    at System.Windows.Forms.Control.CreateControl()    at System.Windows.Forms.Control.OnVisibleChanged(EventArgs e)    at System.Windows.Forms.ButtonBase.OnVisibleChanged(EventArgs e) X forwarding from Ubuntu Server Ed to Windows 7 The Goal: I would like to open a program from my ubuntu server in my windows 7 desktop.  Steps Taken: Putty > SSH > X11 check 'enable port forwarding' I have started VNC Viewer in listening mode started putty ssh session apt get install xinit startx &amp; geany (it's a c language ide; it uses the GUI so I"m using it to test x forwarding)    Error Messages: geany returns "cannot open display" startx returns "setversion 1.4 failed"    I'm working on Windows 7 and headless Ubuntu Server 12.04 LTS  Obviously I forgot something, but I'm having difficulty figuring out what. The goal is to not use sudo apt get install desktop, since I only want to use one program at a time, and anyway my server isn't hooked up to a monitor.   Any ideas? Questions? Thanks for your help! Curios My coach said that for all positive integers $n$, $n^4+4^n$ is never a prime number.  So we memorized this for future use in math competition.  But I don't understand why is it? "One of them was/were you" If I am talking to somebody about a certain group of people in the third person, and then want to refer to the person I am talking with as one of those people, which do I say?     One of them were you      One of them was you. I have an excel spreadsheet with header and survey drill data. Header data contains hole ID, and location coordinates, and the survey data contains related downhole survey with Distance, Azimuth and Dip values.   Since I know the hole location and surface elevation, I would like to be able to convert the survey table to XYZ coordinates as well.  Does anyone has a function / procedure / example?  (VB &amp; ArcObjects)  Header Data:    Survey Data: Check if file is already open Tracking disk I/O by application in Windows? How do we compare the size of numbers that are around the size of Graham's number or larger? When numbers get as large as Graham's number, or somewhere around the point where we can't write them as numerical values, how do we compare them?  For example:  $$G&gt;S^{S^{S^{\dots}}}$$  Where $G$ is Graham's number and $S^{S^{S^{\dots}}}$ is $S$ raised to itself $S$ times and $S$ is Skewes number.  It appears obvious (I think) that Graham's number is indeed larger, but how does one go about proving that if both numbers are "so large" that they become hard to compare?  More generally, how do we compare numbers of this general size?  As a much harder problem than the above, imagine a function $G(x,y)$ where $G(64,3)=$ Graham's number.  The function $G(x,y)$ is as follows:  $$G(x,y)=y\uparrow^{(G(x-1,y))}y$$  Where $G(0,y)$ is given.  I ask to compare $G(60,S)$ and $G(64,3)$ Explanation for "emails"? Azure Same Storage on VM What is the expected value of the number of die rolls necessary to get a specific number? Given a discrete random number generator, such as a six-sided die, what is the expected value of the number of rolls necessary to roll a specific number (e.g. a six)?   I think the result should be given by E$\langle$rolls$\rangle$ = $\frac{1}{6}\sum_{n=0}^\infty{(\frac{5}{6})^n(n+1)}$, but I don't know how to calculate the convergence of that sum.  Also, how do I calculate the variance? I was wanting to initialize some strings at the top of my script with variables that have no yet been set, such as:  str1='I went to ${PLACE} and saw ${EVENT}' str2='If you do ${ACTION} you will ${RESULT}'   and then later on PLACE, EVENT, ACTION, and RESULT will be set. I want to then be able to print my strings out with the variables expanded. Is my only option eval? This seems to work:  eval "echo ${str1}"   is this standard? is there a better way to do this? It would be nice to not run eval considering the variables could be anything. Lock your computer after 5 minutes of inactivity What is the most preferred and easiest way to do pagination in ASP.NET MVC?  I.e. what is the easiest way to break up a list into several browsable pages.  As an example lets say I get a list of elements from a database/gateway/repository like this:  public ActionResult ListMyItems() {     List&lt;Item&gt; list = ItemDB.GetListOfItems();     ViewData["ItemList"] = list;      return View(); }   For simplicity's sake I'd like to specify just a page number for my action as parameter. Like this:  public ActionResult ListMyItems(int page) {    //... } I'm looking at creating a basic ORM (purely for fun), and was wondering, is there a way to return the list of tables in a database and also the fields for every table?  Using this, I want to be able to loop through the result set (in C#) and then say for each table in the result set, do this (e.g. use reflection to make a class that will do or contain xyz).  Further to this, what are some good online blogs for SQL Server? I know this question is really about using system SPs and databases in Sql Server, and I am ok with general queries, so I'm interested in some blogs which cover this sort of functionality.  Thanks Account "last activity time" is not always updated It would appear that the account's "Last activity time" is not updated for every hit.  I've been active on SO all morning, and in the last five minutes have voted on some posts as well as posted an answer.  However,  says:     "Last activity: 2 hours ago from &lt;IP address&gt;"   Is there a certain amount of time that needs to elapse between hits before the activity time is updated again?  This issue could result in Enthusiast badges not being awarded when they should.