Allow users to download when authorised
Allow a user to download a file after submitting their email address
We all know that speed of gravitational waves (GW) and that of light in space are exactly the same (= $c$).  We also know that space is medium for GW.   Does that mean space is also the medium for light?  Because both of them are waves, and speed of a wave is property of the medium.   Is there any other way to justify the identical speed of the two? How can I copy location info from geotagged phone images to images taken with my other camera around the same time? So i did quite a big trip recently, and took lots of pictures with my DSLR and occasionally Android phone. Only after coming back did i read about the whole GPX file, tracklog options in Lightroom. meaning i don't have such a tracklog file.  The android phone did geotag most photos it took. (at least, when it got a gps fix i guess)  So my question is, is there some software or way that will automatically copy the geotag from the android's photos to photos taken on the same time with my DSLR?  Or alternatively, generate a tracklog from the geotagged data in the android pictures? Are you less likely to down-vote someone whose gravatar is a photograph of them? I know this is hard to answer since, to the extent that anyone does this, they likely don't do it consciously. In the spirit of Richard Wiseman and  I just wondered what were people's thoughts on it.  Please bear in mind that that's me in the picture, and if you down-vote this, that'll be a real person hurtin', not some abstract symbol. I was looking at the task manager in Windows 10 and for the first time noticed a secondary dashed line below the solid? What does this line indicate? Can I take clear night sky photographs with my smartphone? is it possible to take clear night sky shots with stars/ planets visible from Redmi Note 4? what settings do I use? when I try to take it just comes black, unless on full moon day with HDR, though stars like Orion's belt won't get captured. Would using a telescope make celestial objects much clear to capture? Chi-squared test when two vectors have different lengths I want to compare two groups (vectors) having different lengths to see if their distributions differ considerably. However, when I use chisq.test, I get an error due to inequalities of lengths:  &gt; chisq.test(factor(Group1), factor(Group2))   results in:  Error in chisq.test(factor(Group1[, col]), factor(Group2[, col])) :  'x' and 'y' must have the same length   Could someone help me with this? Thanks. How to determine the point of intersection of two lines? I have two lines say P1( 0, -1, 0, -1 ) and P2( -1, 0, 0, -1 ). Since I'm working in 2D, there is no Z component. The x,y,z components are normals and the w component is the distance from origin. I am not given the origin or any points on the line.  What method should I use to programmatically determine the point of intersection for these two lines? Predicting the number of decimal digits needed to express a rational number The security guard problem There was a security guard in a bank. In front of him were 100 lockers in rows of 10. He thought of something as he saw all the lockers were closed. He started opening all the lockers whose lock numbers were multiples of 1, then closed all lockers whose number was a multiple of 2,and did the same for 3 and so on. If the locker was open, he closed it, if closed, opened it. He went to open multiples of 1 (all),then 2,4,6,8...and then 3,6,9.. And then finally reached 100.  After all the opening and closing,in the end, how many lockers are open and how many closed? Due to my reputation on Stack Overflow, I have access to different review queues. I want to know if it will change my score/reputation or if it will only provide me some badges?  Maybe this part seems a bit odd, but I want to know why some users spend so much time in the review queues? Is it something about their passion about Stack Overflow or their passion to help others inside the community or does it have some other reasons which I've missed?  P.S. I have read some information like  and  but I will be grateful to have your answer about this. Reprojecting vector layer in QGIS? I have a series of layers of lines (shapefiles) in My Project. The CRS of some are different and to merge them they all must have same CRS.  When I use Processing/Toolbox/Qgis_algorithims/Reproject_layer the reprojection only works if it is allowed to save to temporary file somewhere (it will not change the CRS when I reproject if I try to save and replace it in My Project directory);   I must remove the original from the layer list and reproject the temp file (without changing the CRS) to get it into my project and name it appropriately.  Is there a better way to reproject a layer in Qgis? Installing Cygwin packages from the command-line Possible Duplicate:        I'm looking for a "yum"-link method to install additional Cygwin packages from the command-line. Let's say I want to add the package "Math/bc", then ideally I'd like to be able to do it  using one command as in:  yum install bc   Currently the only way I've found to install new packages is to locate and run the installation file SETUP.EXE file and then scroll to the relevant package, add it, etc. This is  quite cumbersome so I'm sure there is a smarter command-line way to add an additional package. I have a rather long footnote which breaks a listing in two parts, unnecessarily.  Since the listing is more important then the footnote I'd rather lake to have the footnote split.   Can I customize (one or all) footnotes to have a maximal length before they are continued on the next page? Or can I manually split a footnote in two to get the effect? Show that the set of all finite subsets of $\mathbb{N}$ is countable.   I'm not sure how to do this problem. I keep trying to think of an explicit formula for 1-1 correspondence like adding all the elements in each subset and sending that sum to itself in the natural numbers, but that wouldn't be 1-1 because, for example, the set {1,2,3} would send to 6 and so would the set {2,4}.  Multiplying all the elements in each subset and sending that product to itself in the natural numbers wouldn't work either since, for example, {2,3} would send to 5 and so would the set {1,5}. Any ideas? Javascript variables keep track to their copies? Read Post Data submitted to ASP.Net Form I have a working login form in an asp.net application.  Standard stuff with a username and password text box and a button to process the login.  Works fine.  I have a new requirement to allow the user to input the username and password from a separate plain html page that is not a part of my asp.net application.  I plan on achieving this using standard html - form, input, submit button etc.  The form action will be the URL of my asp.net login page and its method will be POST.    What I want to do in the C# code behind page of the asp.net login form, presumably in the Page_Load event, is to check if the request for the page contains a username and password value being passed in.  If it does then I need to read those values and process the login as if someone had clicked the login button on the asp.net page.  If not then I will display the login form as usual.    How do I check for the existence of, and read, the username and password values in the request for my page. Pagination returns 404 after page 20 I got a paged loop that pulls in 4 posts per page from custom post type. It works great, with the only downside that the pagination wont go over the page/20 everything after that is 404, and the posts_nav_link won't show the next arrow at all. Like the pages just aren't there.  In total there are 119 published posts in the custom post type. If I change posts_per_page to, say 6, then I get access to more of the posts from the end, but it also stops at the page/20.  On the production site the pagination stops at 21, I guess because the live database has more entries.  I got the "Blog pages show at most" setting set to 6.  Here's the loop I'm using:  &lt;?php $paged = get_query_var('paged') ? get_query_var('paged') : 1; $args  = array(     'posts_per_page' =&gt; 4,     'orderby'        =&gt; 'modified',     'post_type'      =&gt; "projekte",     'paged'          =&gt; $paged ); $custom_query = new WP_Query($args); $c = 0; while($custom_query-&gt;have_posts()) :     $custom_query-&gt;the_post();     ?&gt;     &lt;article&gt;...&lt;/article&gt;     &lt;?php endwhile; wp_reset_postdata(); // reset the query ?&gt;   I've gone through the functions.php a million times looking for a some limiting get_pre_posts filter but there's nothing I can see.  I also got an error log setup and nothing is returned there, I've tested it that it works.  Any suggestions? How do you construct a std::string with an embedded null? If I want to construct a std::string with a line like:  std::string my_string("a\0b");   Where i want to have three characters in the resulting string (a, null, b), I only get one.  What is the proper syntax? What are best practices for choosing and pairing fonts? I've always found font selection to be a little bit of a mystery. What factors should be considered when choosing a font? How does one successfully incorporate two fonts into a design?  I realize that some factors will include things like:   Legibility Scalability Appropriateness/Mood/Emotion   However, how does one objectively judge legibility or appropriateness? Are there objective principles that can be applied for font selection? If possible, please list resources or examples in your answers. Studies focused on the effectiveness of different fonts would also be extremely useful. This might seem a stupid question but why do Ethernet cables have 8 wires? Cat5 cables were just using 4 of the 8 wires, so only 4 are actualy 'needed'. Why not 12 or 16 wires?