I already know how been and gone can be used with present perfect simple and what difference they make, but with a certain verb phrase like go camping would it be grammatically correct to say I've never gone camping when we are talking about not having experienced a specific activity up to the present moment in life or it should be I've never been camping?
Accourding to ,   We often use "been to" when we refer to completed visits to a place:  Have you ever been to Budapest?  Not: Have you ever gone to Budapest?  If the visit is not complete, we use "gone to".  Joan’s just gone to the shop. She’ll be back in about ten minutes. (Joan has not yet returned from the shop.)  Joan’s just been to the shop. She bought some cakes. Would you like one? (Joan has returned from the shop.)  Now, does that rule apply to the  "Have been on a trip" &amp; "Have gone on a trip"?  So, "I have been on a trip" (I completed the trip &amp; currently I am staying at home)  "I have gone on a trip" (I haven't completed the trip &amp; currently I am on the trip)  And what about "gone crazy" &amp; "been crazy".  Does "He has gone crazy" mean now he is still crazy?  Does "He has been crazy" mean now he is not crazy any more?  Are there any differences between "Have been on a trip" vs "Have gone on a trip" and "Have been crazy" vs "Have gone crazy"?  Note: I am not asking about "been to" or "gone to". I am asking about "been on a trip" &amp; "gone on a trip". Do we apply the same rule of "been to" or "gone to" to "been on a trip" &amp; "gone on a trip"?  Note2:  seems to prove that my thinking is right.
How to add a new kernel to grub2 How can we add a kernel to grub2? i knew the stuff we could do with the former versions, but it seems to have changed. What files should we edit? Reference for statistical mechanics from information theoretic view I am interested in knowing if some one here knows book/notes for statistical mechanics from the information theoretic viewpoint.  Additional Request from user83014  "Jaynes wrote a paper called Information theory and statistical mechanics (1957). I tried to read this but found it somewhat hard to follow, and I suspect it's because it's one of the earlier works, and that a modern text might be more refined since we've had time to work it out. On the other hand, what I've read from physics textbooks don't explicitly talk about information theoretic concepts like shannon entropy.  "Is there a good modern introduction to the information theoretic view of entropy?" Short harvard citation? I need to cite the following way:  The first 3 Letters of the author + the year.  Example:     Kemper 2009 --> [Kem09]   But I don't have any clue how to do that! I know that one can use "they" / "them" / "their" in place of "he" / "him" / "his" or "she" / "her" / "hers" when the subject's / direct object's gender is not known; for instance, just looking at the default user's about me section on Stack Exchange sites:     Apparently, this user prefers to keep an air of mystery about them   My question is what happens when someone wants to reference the subject using a pronoun instead.  Should the verb be conjugated accordingly to the pronoun? E.g.:     Apparently, they prefer to keep an air of mystery about them   Or should the conjugation be retained? E.g.:     Apparently, they prefers to keep an air of mystery about them   The former looks unclear because it wouldn't allow the reader / listener to understand if the writer / speaker is talking about a single person or about a group of people, however the latter sounds very weird, at least just to the non-native speaker which I am. Extended Rigid Bodies in Special Relativity I was reading Landau &amp; Lifshitz's Classical Theory of Fields and I noticed that they mention that an extended rigid body isn't "relativistically correct".   For example, if you consider a rigid rod and apply a torque at one end, by definition of being rigid, the whole body must start rotating at the same instant. But the information about the force being applied cannot travel faster than the speed of light.   The book hasn't mentioned how to resolve this paradox, and after thinking about it for a while, I'm wondering if one can even define a rigid body in a relativistically correct manner.  To summarize: How does one define a rigid body in special relativity? I'm new to linux and the terminal. As I learn how to use the terminal to navigate through directories, I like to use the gui file explorer to mirror my terminal navigation. The icons and file extension info in the gui file explorer help me figure out what everything is. However, I can't access the root folder via the gui, I can only access it via the terminal. Is there a way to enable access to the root folder outside of the terminal? Can I fetch the value of a non-standard CSS property via Javascript? Remove pseudo nodes in QGIS Is it possible to apply modifiers to multiple objects at once? Run a GUI program at startup I am using Ubuntu 14.04. I wrote a small script named trial. The contents of the script are as follows:   #!/bin/sh SHELL=/bin/sh PATH=/bin:/sbin:/usr/bin:/usr/sbin      sh -c firefox   I copied the script to /etc/init.d, modified permission using chmod +x trial and used update-rc.d trial defaults. The file made link but when I rebooted the machine. It did not run firefox. I tried cron @reboot but with no success. I tried rc.local too again failure. Environment variables when run with 'sudo' Installing to SDCard by default I would like to know whether there is a way to tell Android to install applications on the micro SD card by default instead of having to download applications to internal memory first and then having to move them to the SD card manually.  Thanks JavaScript: getting ImageData without canvas I've seen the phrase "sh compatible" used usually in reference to shells. I'm not sure if it also applies to the programs that might be run from within shells.  What does it mean for a shell or other program to be "sh compatible"? What would it mean to be "sh incompatible"?  Edit: This question asking the difference between bash and sh is very relevant:   I'd still like a direct answer to what it means to be "sh compatible". A reasonable expectation might be that "sh compatible" means "implements the Shell Command Language" but then why are there so many "sh compatible" shells and why are they different? If $x,y,z\in\mathbb R\setminus \{1\}$ and $xyz=1$, prove that $\frac{x^2}{(x-1)^2}+\frac{y^2}{(y-1)^2}+\frac{z^2}{(z-1)^2}\ge 1$. If $x,y,z\in\mathbb R\setminus \{1\}$ and $xyz=1$, prove that $$\frac{x^2}{(x-1)^2}+\frac{y^2}{(y-1)^2}+\frac{z^2}{(z-1)^2}\ge 1$$  Without using calculus. There are a few ways I've tried solving this:  $1)$ We could try using the Cauchy-Schwarz inequality: $$\frac{x^2}{(x-1)^2}+\frac{y^2}{(y-1)^2}+\frac{z^2}{(z-1)^2}\ge \frac{(x+y+z)^2}{(x-1)^2+(y-1)^2+(z-1)^2}$$  But it's apparent that nothing's useful here.  $2)$ We could use AM-GM as well: $$\frac{x^2}{(x-1)^2}+\frac{y^2}{(y-1)^2}+\frac{z^2}{(z-1)^2}\ge 3\sqrt[3]{\frac{x^2y^2z^2}{(x-1)^2(y-1)^2(z-1)^2}}=\frac{3}{\sqrt[3]{(x-1)^2(y-1)^2(z-1)^2}}$$  So we only have to prove that: $$\sqrt[3]{(x-1)^2(y-1)^2(z-1)^2}\le 3$$  We could raise both sides to the power of 3: $$(x-1)^2(y-1)^2(z-1)^2\le 27$$  But this inequality doesn't hold.   $3)$ We could try cleaning the denominators by multiplying both sides by $(x-1)^2(y-1)^2(z-1)^2$. After a bunch of expanding and simplifying we get that: $$x^2y^2+y^2z^2+x^2z^2-6(xy+yz+xz)+2(x+y+z)+9\ge 0$$  I can't tell so easily whether the inequality is true or not. You could help me out on this one. Just don't forget that $x,y,z\in\mathbb R\setminus\{1\}$ and so we can't just simply use AM-GM, unless we're using it for squares that have to be non-negative. No "Login using Google" option in Android app Can Mjolnir "stick" to anything? Is it possible to find all classes or interfaces in a given package? (Quickly looking at e.g. , it would seem like no.) Let $$ f(x) =    \begin{cases}\begin{align}     1\quad&amp;\text{ if }\; 0\leq x \leq 1 \\     2 \quad&amp;\text{ if }\; 1&lt;x \leq 2 \\   \end{align}\end{cases}$$  Then $\int^2_0 f(x)dx=3$ and an anti derivative of f(x) is $$F(x)=\begin{cases}\begin{align}     x\quad&amp;\text{ if }\; 0\leq x \leq 1 \\     2x \quad&amp;\text{ if }\; 1&lt;x \leq 2 \\   \end{align}\end{cases}$$ But, $F(2)-F(0)=4-0=4 \neq 3.$ Why has this happened?  Find an anti-derivative $G(x)$ of $f(x)$ such that $G(2)-G(0)=3$, the correct answer.  My attempt: $F(2)-F(0)=4 \neq 3$ because we need to break it up into two parts like this: $\int^2_1 2x dx + \int^1_0 x dx = x^2|^2_0 + \frac{1}{2} x^2|^1_0 =4-1+\frac{1}{2}-0=3.5$ but this is not right either. :(  For the "Find an anti-derivative $G(x)$..."I'm completely lost but perhaps if we solve the first part then I'll understand what it's asking for there.  Any help would be appreciated. VirtualBox Toolbar is hidden! How to show it?