Conservation of quantum information Bosons occupy the same quantum states, even if fermions obey Pauli's Exclusion Principle. Heisenberg's Uncertainty Principle rules out determining the quantum states occupied by two close fermions, etc....  I mean to say is it impossible in Quantum Mechanics to trace the history, or follow it, of a boson or fermion? There are inevitable errors. Why are we concerned about the loss of information in a black hole, where degeneracy breaks down? I mean, how are two mysteries different, with respect to conservation of information? We have laws of black hole thermodynamics, which prohibit the loss of energy...
Why is information indestructible? I really can't understand what Leonard Susskind means when he says in the video  that information is indestructible.  Is that information that is lost, through the increase of entropy really recoverable?   He himself said that entropy is hidden information. Then, although the information hidden has measurable effects, I think information lost in an irreversible process cannot be retrieved. However, Susskind's claim is quite the opposite. How does one understand the loss of information by an entropy increasing process, and its connection to the statement “information is indestructible”.  Black hole physics can be used in answers, but, as he proposes a general law of physics, I would prefer an answer not involving black holes.
How can you combine all lines that end with a backslash character? Using a common command line tool like sed or awk, is it possible to join all lines that end with a given character, like a backslash?  For example, given the file:  foo bar \ bash \ baz dude \ happy   I would like to get this output:  foo bar bash baz dude happy How do i enter my numeric password in iPhone 4 in VoiceOver mode? My iPhone 4 is in VoiceOver mode. It`s currently locked and not accepting my passcode which is absolutely correct. And now it's saying iPhone is disabled.  Any solution? Tilde (~) File in Macintosh Directory Last night I discovered what looks like an unusual file named "~" (tilde) in the root of my "Macintosh HD" directory on my MacBook.    Finder reports the file is 2.2MB in size, of kind "TextEdit.app Document", and was created on 22nd January 2014 (so about a month ago).  I haven't noticed any operational issues with OS X or it's applications.   I haven't yet touched the file but would obviously like to remove it.  I am very conscious that '~' is a special alias to the user home directory and thus I would appreciate any recommendations in removing the file in a safe manner that isn't likely to nuke my home directory or screw up the operation of applications or OS X. I don't know whether to delete or rename and whether to use Finder or the command line.   It's entirely possible that I created the file by accident since I've recently been drafting and running various shell scripts that use the ~, user home alias.  MacBook Pro 15" (Retina, Mid 2012) Yosemite What is Chromatic Aberration? Is it a physical part of the lens, or just an optical illusion? Accessing inherited variable from templated parent class Consider the following code:  template&lt;class T&gt; class Foo { public:   Foo() { a = 1; }  protected:   int a; };  template&lt;class T&gt; class Bar : public Foo&lt;T&gt; { public:   Bar() { b = 4; };    int Perna(int u);  protected:   int b;  };  template&lt;class T&gt; int Bar&lt;T&gt;::Perna(int u)  {    int c = Foo&lt;T&gt;::a * 4; // This works   return (a + b) * u;    // This doesn't }   g++ 3.4.6, 4.3.2 and 4.1.2 give error   test.cpp: In member function `int Bar&lt;T&gt;::Perna(int)': test.cpp:25: error: `a' was not declared in this scope   g++ 2.96 and MSVC 6, 7, 7.1, 8 and 9 accept it, as do (at least) older Intel and SGI c++ compilers.   Do the new Gnu C++ compiler obey the standard or not? If they do, what is the rationale behind that inheriting class is not able to see a protected inherited member variable?  Also, if there's  int A() { return a; }    in Foo, I get error  test.cpp:25: error: there are no arguments to A that depend on a template parameter, so a declaration of A must be available test.cpp:25: error: (if you use -fpermissiveâ, G++ will accept your code, but allowing the use of an undeclared name is deprecated)   when I try to use it in a member function of Bar. I find that curious as well: Bar inherits Foo, so I think it's obvious that A() in scope of Bar is Foo::A(). How does editing work? Inherited values between polygons in QGIS In this project, I have three polygons, see the image below  'Polygons_From', includes input attributes, i.g. &quot;Value_1&quot;, &quot;Value_2&quot;, &quot;Value_3&quot;, and $area for each quadrate (on the image there are two types of them). 'Polygons_To' polygons for which new values &quot;Value_1_new&quot;, &quot;Value_2_new&quot;, &quot;Value_3_new&quot; need to be defined 'Border' defines an area where the calculation should be done.   My task is to transfer values from 'Polygons_From' into 'Polygons_To' based on a certain aspect/ratio. Of course, I can simply achieve it with the 'Union' function as was suggested in . It uses $area-factor, but perhaps there are better approaches that will lead me to a much more efficient output? So, I am asking for a recommendation regarding the technique/workflow that can be applied in QGIS 2.18. Shall I consider only $area or there are some other criteria? Moreover, I looking forward to finding some papers that may improve my general understanding of the methodology.  References: Are there any references to Eru or the Valar in the Lord of the Rings movies? The closest references to Eru or the Valar in Peter Jackson's Lord of the Rings and The Hobbit movies I can think of are Gandalf's vague description of his resurrection ("I've been sent back... until my task is done.") and his later description of Aman to Pippin ("White shores and beyond, a far green country under a swift sunrise." -- as an aside, he's taunting Pippin here, since Hobbits suffer from the Gift Of Men) and the equally vague information viewers are given about where the elves are going when they leave Middle Earth.  Are there any more direct references I'm missing? Maybe a mention of Aule by a dwarf? MySQL autoincrement column jumps by 10- why? I have a couple tables in which I created an object ID as either an Int or Bigint, and in both cases, they seem to autoincrement by 10 (ie, the first insert is object ID 1, the second is object ID 11, the third is object ID 21, etc).  Two questions:   Why does it do that? Is that a problem? Is it possible to make an EXACT ISO of my system to put on other computers? Here is an interesting piece of code that my fellow team members were just having a slightly heated discussion about...    Dim fred As Integer    If True Then fred = 5 : fred = 3 : fred = 6 Else fred = 4 : fred = 2 : fred = 1   After executing the above code snippet, what is the value of fred?  Try not to cheat and debug the code.  This is a highly contrived code example that started out as an example of using the colon with an If statement, but then someone decided to take it upon themselves to proffer a result for fred.  UPDATE: I would not normally write code like this and this snippet only serves as an example. As it so happens, this question originated from a discussion involving the creation of a coding standards document for our team. TeXShop and Mac preview crashing when opening latex/beamer built pdfs After updating to Sierra 10.12.4 last week, TeXShop crashes:   when opening an existing .tex document that has a pdf associated to it immediately after compiling a new document, i.e. as soon as a pdf is created.   Furthermore, preview crashes opening almost any pdf that has been created with TeXShop. There is virtually nothing on the internet about it, and the only solution seems to be a complete reinstall of MacOSX (so as to reinstall the supposedly broken preview), which I'd like to avoid if at all possible.  Someone else has described a similar issue, but has not received any responses ().  I would be very grateful for some help, as I can neither produce work, nor look at any at the moment. Many thanks! Is the electromagnetic spectrum discrete? Is it possible to highlight text inside of a textarea using javascript? Either changing the background of just a portion of the text area or making a portion of the text selected? how many conditional sentence types are possible? I wonder how many conditional sentence types are possible. Basically, there are four main and two mixed types. By mixing tenses, it could be up to nine of them. Are the rest viable?  I came across the following examples in Full Spate Pre-Profficiency Primer:   After you have just sold alcohol to a young guy. If he is if under eighteen, you should not have sold him the alcohol. If he promised to bring the drinks, he will. If you will take a seat, the doctor will see you shortly. (Likely, the former will demonstrates politeness only.) I would be grateful if you would tell me a little about your friends. (The same politeness, but would instead.) If he will keep eating all those biscuits, he can not expect to stay as slim as he used to be.   I would be grateful if someone could shed more light on the topic. How to make a different font and color of text in labels? Is it possible to make a bold or italic, and change the color of individual words Label?  Example: the first line is bold in red text, font 12, second row 10 green italic font Complement property of DES I'm supposed to show the complement property of DES ($c=DES(p,k) =&gt; \bar c = DES(\bar p, \bar k)$).  My idea was to just start the algorithm with $\bar p$ and see what happens (ignoring the initial permutation for now). I looked at it step by step and got the the point where $R1 = \bar L1 \oplus f(\bar k1, \bar R0)$. So I figured I had to show that $f(\bar k1, \bar R0) = \bar f(k1,R0)$. Is that even right so far? Because I got stuck at the point where the S-Boxes are used. Why would $S(\bar x) = \bar S(x)$?  Somewhere else I read something about a formal prove using induction, but I don't know how I would do that either... How to open a PDF file from terminal? I used to work on the Mac terminal before and I used:   open file2open.pdf   and the PDF file would be opened on preview or whatever my default viewer was. When I use it in the terminal in Ubuntu I get this error message:   Couldn't get a file descriptor referring to the console How to print every Nth character of a string? This line of code does exactly this except I want it to start at the first character not the 7th. $ echo 1234567890abcdefghijklmnopqrstuvwxy | sed 's/.\{1,7\}\(.\{0,1\}\)/\1/g'  What I'm looking for is 19gow Is it possible to hide curves' guides in edit mode?