I was hoping to get some technical answers to this question, and was really asking because I thought it'd be a fun question. Have at it folks.
I read somewhere that according to relativity, it is possible - involving black holes and other stuff - to jump into the past. Is it possible for anything to go back in time either continuously or by jumping?
How to show $\lim_{n \to \infty} \sqrt[n]{a^n+b^n}=\max \{a,b\}$? GPS PPS signal corresponds to data time? I currently have an Adafruit Ultimate GPS connected to an Arduino that outputing GPS data (nmea sentences) once per second.  There is also a pin on the GPS outputting 1 PPS signal.    My question is whether the pulse of the PPS suppose to match the time that the GPS data is coming in i.e are they are coming in at the same time?    Also does PPS pulse come in at the beginning of a UTC second or is it random and simply once a second? Map matrix element to string Can Yoda pilot a starfighter? In a trailer for Kinect Star Wars, I saw Yoda driving a Jungle Speeder and that got me wondering. Can and has Yoda ever piloted a starfighter?  During the Clone Wars, it seems plausible that they could commission a small-sized green Jedi starfighter. Is their any indication that he has piloting experience? Whenever I open a .sh file, it opens it in gedit instead of the terminal. I can't find any option similar to Right Click → Open With → Other Application... → Terminal.  How do I open this file in the terminal? What Is the Real Name of the #? Category of Grp is not a subcategory of Set I use Ubuntu 18 and have little experience with Linux commands. I have two files:  file 1:  a,txt1,v1 b,txt2,v2 c,txt3,v1 d,txt4,v2   file2:  a,txt5,v2 b,txt6,v1 c,txt7,v1 d,txt8,v2   I want to print the 1st and 3rd column values where the the 1st column value is identical and the 3rd column value has changed from v1 to v2. So my expected output should be:  a   The second query is for the 3rd column values that has changed from v2 to v1. So my expected outcome:  b IOS 5.1.1 Safemode problem I jailbroke my old iPod Touch 3rd Generation, with IOS 5.1.1, using the latest version of absynthe. It worked for several months, but then it randomly stopped. It went into safe mode, but the touch screen wouldn't work. It showed the lockscreen, but nothing worked at all, except for the physical buttons. The only way to reboot is to follow the same steps as DFU mode (Hold power button 3 sec, then home button AND power for 10, then just home for 8)... However, it always boots right back into Safe mode.  I had to restore, and once rejailbroken, it worked fine, until I installed SBsettings. Then it did the EXACT same thing, and I had to restore and re-jailbreak AGAIN! The other day, I finished installing ALL of my extensive list of tweaks, and got it to about where I wanted it, when lo and behold, it booted to safe mode again. I have spent so much time on this, and I do not want to do it again. Does anybody here have any knowledge on the topic? Is there a program I can run from my computer to manually control the device or kick it out of safe mode? Is there some other method of doing this? I am looking for any solution OTHER than restoring. I have done that several times.  Also, I know the problem isn't with my jailbreak. It worked for several months before, then one day stopped. Now, it has the problem within a day of rejailbreaking, OR instantly if I install SBsettings. I re-installed the jailbreak, and applied the new one as well, and that didn't work. I have given up, and don't want to go through the painful process of restoring, rejailbreaking, and re-installing all of those tweaks again.  Also, because I can't get into my iPod, I can't provide a list of tweaks. I would if I could, but it just can't happen unless I can get in there. Why does strcmp() return 0 when its inputs are equal? When I make a call to the C string compare function like this:  strcmp("time","time")  It returns 0, which implies that the strings are not equal.  Can anyone tell me why C implementations seem to do this? I would think it would return a non-zero value if equal. I am curious to the reasons I am seeing this behavior. Hi all im a noob on Ubuntu/Linux World,  So i need some that give a full tutorial to How to install  from apachefriends.org correctly on Ubuntu 11.10 + all beyond Ubuntu for 32 bit and also 64 bit Desktop Version.. and also i need this:   Make a Folder on Your Home Folder and Linked to htdocs from Apache Web Server Make a GUI interface for Xmapp Start Xampp when Ubuntu Boot Up or Start Ubuntu   (Note: i ask it for both X86 and X64 so people in the further can see the tutorials)    New Data:  What i did was i download from  for now and i also what to say that I'm currently running Ubuntu 11.10 X64 bit for Dell Studio 1558 processor intel i3  i will let you know guys which solution was the best, and it is for a Desktop Version of Ubuntu 11.10 (Laptop 15 inch screen ^_^ ) not Server Ubuntu If $a \cdot a = 1$ then $a = 1$ or $a = -1$ Let $F$ be a field.   And let $a \in F$ such that $a \cdot a = 1$.  Claim: $a = 1$ or $ a = -1$  Before, I begin with the proof I cannot understand what $ a = -1$ represents...  Is $a = -1$ representing the inverse of $a$?   I am capable of getting to $a = 1$ with no trouble, but how do you get the $-$ sign to show up in your proof?   Proof: This is my attempt at getting to $a=-1$.  If $a = 0$ then we have $0 \cdot 0 = 0 \neq 1$. Then this implies that $a \neq 0$ which implies that $ \exists b \in F,$ s.t. $a \cdot b = 1$, i.e. $b$ is the multiplicative inverse of $a$.  Knowing this fact prove as follows...:  $a \cdot a = 1 \implies$ $ (a \cdot a) \cdot b = 1 \cdot b \implies$ $a \cdot (a \cdot b) = 1 \cdot b \implies$ $a \cdot 1 = 1 \cdot b \implies$ $ 1 \cdot a =1 \cdot b \implies$ $a = b$.   But since $b$ is the multiplicative inverse of $a$ is this enough to say that $a = -1$? Does anybody know how to make a 'always-on-bottom'-windows, or a window pinned to the desktop? It should receive focus and mouseclicks, but should stay at the bottom of the Z-order. It would also be great if it could stay on the desktop even when user do a minimize all or show desktop operation.  Both delphi and c# solutions (or partial solutions/hints) would be great. Does Qt have a C interface? Can Button[] generate output without using Print[]? How to put a unique material on duplicated objects separately? I've a sphere and then duplicated it. In object tree they are displayed as three siblings. I selected on of them and created a green glass material through node editor however this material was assigned to all three spheres. I confirmed that my selection is only on one sphere. What am I missing? Is Ubuntu based on Debian unstable or Debian testing? which of the two it is? Creating Logo with Fancy Font I am trying to creating a logo that resembles this one shown below, but I do not know the best way of going about it. I know of a fonts package that may be useful, but not sure how to overlay the letters on top of each as so. Would anyone know a neat way of accomplishing this?  Picture of Logo: How to create a file system as a non root user? I'd like to create a filesystem image as a non-root user, the problem I'm facing is that the way I'm currently doing it, it needs a mount and as a non-root can't do a mount.  This is what I'm now doing:  #!/bin/sh  IMG="app.ext4" LBL="PIHU_APP" MNT="/mnt/PIHU_APP" APP="/home/buildroot/board/arctura/PIHU_APP/application"  #64MB: dd if=/dev/zero of=$IMG bs=4096 count=16384  mkfs.ext4 $IMG e2label $IMG $LBL  mkdir -p $MNT mount -o loop $IMG $MNT cp -r $APP $MNT sync umount $MNT   I have full root access, so I can setup/prepare anything, but the script will be executed from a non-root account.  However, I have a feeling there may be a better way that might not even need mounting, but I'm not sure.. Facing an error "*** glibc detected *** free(): invalid next size (fast)"