What is the classical explanation for why the microwaves won't pass through the microwave door? I know the microwaves behave like particles and dont pass through the microwave door but I am asking why they do so.
If I look through the microwave window I can see through, which means visible radiation can get out. We know also that there is a mesh on the microwave window which prevents microwave from coming out.  My question is how does this work? how come making stripes or mesh of metals can attenuate microwave radiation yet allow visible radiation?  Looks like an electrodynamics problem to me with periodic boundary conditions (because of the partitions on the microwave oven window). Is it discussed in any textbook?
How to disable Ctrl+Shift+U? Ctrl+Shift+U is a combined shortcut in Eclipse. But when I press it, it shows up a u, just like input with an underline. I guess this shortcut has been declared by Ubuntu, so I can't use it. I used to solve this problem by typing Caps Lock first. Is there any better method? Could someone with experience in using these exercise typesetting packages please offer a quick compare and contrast of these packages to help me choose?  Packages under consideration are:         Having read briefly the documentation, they all seem to do the same thing generally, so could you please focus on the differences?  Some differences will not be obvious until I've learnt and used all the different packages but I want to better appreciate the differences now, a priori. MiKTeX and Perl scripts (and one Python script) Why do employers require you to spread your 401(k) contributions throughout the year to get the maximum match? I think the title says it all. I can't see any reason employers have to incentivize employees to contribute to their 401(k) evenly throughout the year. Instead couldn't they use a relatively simple formula that is based on how much of their income the employee has contributed to their 401(k) thus far for the year? If that or their current contribution is over the threshold, they get the match this pay period, even if they didn't contribute anything.  EDIT: To clarify, my employer matches 100% of the first 3% of my contribution and 50% of the next 2%. The match is added every pay period along with my contribution. I am pretty sure there is no "true-up" feature, so if I were to hit the $17.5K limit early, and not be able to contribute at least 5% of my salary, I would not get the full match. So I have to be careful to make my contributions evenly throughout the year to get the maximum match. Just trying to figure out my employer's motivation for requiring this. User is suspended network-wide, except not really A user has been active on one of the sites recently, even though they're concurrent suspended network-wide on the rest of the network. How is this possible, and is it possible to evade a network suspension on only one site? If $U_1$, $U_2,\ldots,U_n$ are proper subspaces of a vector space $V$ over a field $F$, and $|F|\gt n-1$, why is $V$ not equal to the union of the subspaces $U_1$, $U_2,\ldots,U_n$? Since the Denoise feature was added to Blender I only use the default setting with it and it really does the work. But sometimes the denoise is noticable on some of my renders. How can I overcome the blurred effect? Denoising for me is a big help because my system is quite aged. "She need not worry" or "she needs to not worry"? I just came across this weird use of &quot;need not&quot; on :  Madam/sir, My daughter is stuck in Uk . She has lost her  . She is difficult to return back India home [sic]. Please help  In response,  says:  She need not worry. She should stay where she is. Just tell her to keep herself safe. Please delete your tweet.  Shouldn't it be &quot;she doesn't need to worry&quot; or &quot;she needs to not worry&quot; given that the subject is &quot;she&quot; (singular)? Or is this some kind of grammatical construction I don't know? I believe who wrote it was a native speaker of English and they might be correct. Can someone explain this please? I was trying to fix my audio problems using suggestions from . One of the comments suggested I execute this and only this:     killall pulseaudio   So I did, and I restarted my computer just in case, but all it did was remove my soundcard and I still couldn't hear anything. Now I don't know how to get my soundcard back.  Please note that I am extremely inexperienced when it comes to Ubuntu. Evaluate forecasting ability of GARCH models with RMSE and MAE When I was using ubuntu 14.04, it's easy to set title. Just press F2 or move mouse to top menu. But there is no menu on ubuntu 16.04 and press F2 can't change the title. What should I do? If Obi-Wan and Yoda were trying to keep Luke safe from Vader, why would they let him keep the Skywalker name? Commandline shortcut for current directory similar to ~ for home directory? When i use the cp or move command in a terminal window, i'm currently with bash in a certain folder like this.  NES@server:~/Desktop/dir1$   And now i wanna copy a file from here ~/anotherdir/dir2 into the current chosen folder in bash (dir1) i would use the command  cp ~/anotherdir/dir2/file ~/Desktop/dir1   does a shortcut string exist to refer to the current chosen directory? So that in this example i don't have to provide the full path to the target dir, but the command knows it should use the current chosen directory in bash? i.e. as ~ stands for the home directory? Mount error: "unknown filesystem type 'exfat'" When trying to mount an exfat filesystem, I get the following error:  Error mounting /dev/sda6 at /media/gkp/Backup: Command-line  `mount -t "exfat" -o "uhelper=udisks2,nodev,nosuid" "/dev/sda6" "/media/gkp/Backup"'  exited with non-zero exit status 32: mount: unknown filesystem type 'exfat'   Exfat is used on some USB sticks and camera sd cards. What can I do to mount this type of filesystem? How to get text under mouse in any open window What are the criteria for posts to be included in "Top network posts" on new profile page? From the name of it, certainly it looks for posts with the highest scores. However, recently I found that some of the posts are not listed. Example: My  (not sure if it's that good, just because hot network question) was included in some point, but then it's not listed on . I guess it's because the question was closed, e.g as a dupe? (I don't have any hidden communities on the settings)    However, it's listed normally on .    Also, what other criteria that makes the posts to be included/excluded in &quot;Top network posts&quot;? How to show that $\mathbb{Q}$ is not $G_\delta$ Do computer viruses affect all user accounts on a computer? Do computer viruses affect all user accounts on a computer?  IF a virus affects a local user will that effect administrator account and vise-versa? Can the Universe be deterministic and still allow free will? How can I download an older version of Xcode? I am trying to download Xcode from the App Store, but it says that I have to have a newer version of macOS. But I don't have enough space on my computer to upgrade. Its like 8 gigs or something like that and if I only could download Xcode that was compatible with macOS Sierra that would be nice.