A radar system has a transmitter that emits radio waves called a radar signal, consisting of electromagnetic radiation. What happens when it meets with a strong superconductor, considering the fact that a superconductor expels magnetic fields. Will there be any reflection back to the radar receiver, or will the signal be refracted?
A type-I superconductor can expel almost all magnetic flux (below some critical value $H_c$) from its interior when superconducting. Light as we know is an electromagnetic wave. So what would happen if we shine a light deep into a type-I superconductor? Suppose the magnetic field of the light is significantly lower than $H_c$.  And what about type-II superconductors?
What is the population of the Star Wars Galaxy? What does the red background on an item mean? With the latest update, you can now use gyms like stops and get items. So far, every time I have done so there has always been one item that has a red background and number.    Is this a bonus item since I am part of red team? Is there any special meaning to it at all? It's known that when you're connecting to a wrong server via ssh and send your password  to it, your password comes in a plain text and a server saves it by default. Probably. I wonder, where I can retrieve it? I don't see it in /var/log/auth.log, although I do see all the attempts to authenticate. -I'm not a religious person so this is not a denial. I'm just trying to understand the most fundamental topic about Universe.  -I know the Big Bang cosmological model is not a law but it's a theory.  -I'm a non-Native English speaker so please let me know if the question is not clear for you.  -This question came to my mind after watching Gravitational waves as dark energy? How to reduce the thickness of letters Lightning - dynamically creating force:inputField How to add a custom icon or symbol to a flag link? I'm working on a 'sample request' implementation for a commerce site using , , sessions and a little custom code.  I'd like to add an icon or a symbol to let people know that an item they are viewing has been flagged.  I'm not sure exactly how to approach this, I can imagine perhaps adding a conditional field that displays an image or check box that is then changed by  or ajax, or perhaps something more complicated in JavaScript?  It could really be as simple as adding a checkbox that is checked or unchecked as the flag link is clicked or maybe even changing the css/html on click to be identified as marked.   Anyway, grateful for any advice here. Conditional expectation on more than one sigma-algebra How to combine two QUERY results into one column I have the following QUERY  =query(XX!A2:A;" select A where A&gt;'50' ")   and  =query(YY!A2:A;" select A where A&gt;'50' ")   how do I combine these two data sources so I don't have to have two separate columns they process data to?   best would be if the 1st row from XX is followed by the 1st row of YY, 2nd row followed by 2nd row... and so on If the above option is not easily possible, it is OK for one query to be followed by the second one (if I expect correctly that the start of the second will be moved with newly added data into the first one) Wanted: question mark instead of bibtex key for missing citations (biblatex) Instead of having the citation key showing up in the document for missing references, I want to only have [?], as it is the case when using the default bibtex without biblatex. This behavior is driving me crazy, as it messes up all the formatting (especially in tables). I want to focus on writing and only later on deal with the erroneous citations.  This question is related to    and its MWE can be used. However, as pointed out beforehand, I want the question mark in the text instead of the citation key to not mess up the formatting (for missing citations). Can I install a ROM made for a different device? I own a MicroMax A100. I want to install the latest version of a different ROM (Samsung or Nexus).  Is it possible? If so, can you tell me how?  If not, can I install a ROM made for a different device, but from the same manufacturer? For example, could I install a ROM for the MicroMax A110, which is the successor of A100? How can I unload Oracle database tables into a csv files? I need to retrieve certain data from an Oracle 11g release 1 database and provide it as one or more CSV files. The data resides in multiple tables and/or views. All this should work via the command line. What would be the best approach to this? Sadly, yesterday I've spilled some water on my MacBook Pro (El Capitan). Before you yell at me - it was closed, turned off and it wasn't a lot of water, the laptop was wet only on the top and under - not inside.  Today I've turned him on. At first battery wasn't recharging for some reason, but SMC reset fixed the problem.  At the first booting speaker was like talking to me, hard to explain but it was weird. Also only right speaker was "talking", despite the fact that only left side of the laptop was watered. Then there was no sound at all, not from the speakers, nor from the headphones. Also microphone's not working. USB ports are okay. The water was spilled from the left side of the laptop. I know this is hardware issue, and something's broken, but I want to be 100% sure. No it's not muted. I've also tried NVRAM reset a few times, but it doesn't fix the problem :(  There might be one factor, before spilling, my laptop "died" for the first time (battery energy ran off), but I doubt it's the case. (but hey, every info matters, right?)  It wouldn't be weird for me, if only left speaker wouldn't work, but built-in microphone not working is kinda weird in this case, isn't it?  I just want to ask you guys, what else can I check, before I'll be 100% sure it's dead inside?  I've plugged in external microphone - it's not working too. Does assigning objects to null in Java impact garbage collection? Conditionally Rendering Visualforce element based on user profile I have a controller extension and want to use the Tabbed view to get rid of the Chatter caused endless scrolling.      public class UserProfileGetter {     public UserProfileGetter(ApexPages.StandardController controller) {      String userProfileName = [select u.Profile.Name, id, UserType from User u where u.id = :Userinfo.getUserId()].Profile.Name;      system.debug('Profile===================='+userProfileName);      }    }   When I run the debug it shows my Profile as 'System Administrator' correctly.  My VF page code:  &lt;apex:page standardController="Account" extensions="UserProfileGetter" showHeader="true" tabStyle="account" &gt;   &lt;apex:tab label="Opportunities" name="Opportunities" id="tabOpp" rendered="{userProfileName!='Chatter Content'}"&gt;          &lt;apex:relatedList subject="{!account}" list="opportunities" /&gt;       &lt;/apex:tab&gt;        &lt;/apex:tabPanel&gt; &lt;/apex:page&gt;   So the logic for render I want is - if the user profile name isn't Chatter Content, render. But if I have this logic in the page it won't render for anyone, including me. Ideas? Thanks  Amending - to query other variable on the user, a checkbox called "Admin Team" to display the tab for Account Teams related list, I query for both like this:  public class UserProfileGetter {     public String userProfileName {         get {             return [                     select Profile.Name                     from User                     where Id = :Userinfo.getUserId()                     ].Profile.Name;         }     }     public boolean userAdminTeam {         get {             return [                     select Admin_Team__c                     from User                     where Id = :Userinfo.getUserId()                     ].Admin_Team__c;         }     }      public UserProfileGetter(ApexPages.StandardController unused) {     }   }   And then I use like this:   &lt;apex:tab label="Account Team" name="Account Team" id="Act" rendered="{!userAdminTeam}"&gt;   Thanks all. Show that $a(-1) = (-1)a = -a $. While learning about Random variables I came across the mean of random variable X.  The definition says that the expected value of random variable E(X) = Mean of Random variable X  I am not able to understand why is that so. Can any one please help me with it Install ffmpeg in Ubuntu 12.04 LTS Background :  I used ffmpeg to merge two videos side by side. First I install ffmpeg by following command as it suggest by Ubuntu itself.  sudo apt-get install libav-tools   or   sudo apt-get install ffmpeg   But then I realize it is not the correct version since it doesn't support for -filter_complex and few other functions.   After a few hours researcher I found  and I succeed with video conversion as well. As per that article, it is suggesting we need to build it our own.        Question :  What is easiest way to install that ffmpeg version (which is support for -filter_complex ) without following all those steps ? How do I fix a "Failed to download package files" error?