I am using dual monitors (equal) and have recently switched to 11.10.  When I used 10.04, the top panel with indicators, etc. was showing only on my left monitor, leaving the entire space of the right monitor available for app windows.  In 11.10, the top panel is duplicated on the second monitor. IMO, it makes no good, just wastes precious desktop space.  Is there any way to make the top panel to show only on one monitor?  Thanks in advance!
How do I remove top bar on secondary monitor??
Windows vs Linux Local Time? Ever since I started using Linux in dualboot with Windows I noticed that when I rebooted the machine, the time on the other OS was wrong, e.g. it was 12:00 on Linux, then I rebooted and on Windows it was 18:00, and when I checked the BIOS, the RTC was set to 18:00. Since my timezone is -06:00 CST I assume Linux just sets the RTC’s time to UTC and re-calculates the time based on the timezone, whereas Windows just sets the RTC to the local time. Both use the same NTP server to sync the time.  The question is, which one is doing the right thing? On which one should I set the timezone setting to UTC in order to have the right time on both? Covariant derivative ambiguity I'm studying general relativity and am running into an ambiguity with the covariant derivative. The covariant derivative acting on a scalar is, in a co-ordinate basis, simply $$\nabla_X f = X^a \nabla_a f = X^a \partial_a f $$ whilst when acting on vectors or tensors, the covariant derivative includes extra terms involving the connection coefficients $\Gamma$. My problem is that I'm not sure what happens when the covariant derivative acts on the components of a vector. So the $X^a$ in the above expression are each scalar functions, and so when we write $\nabla_Y X^a$, do we assume the covariant derivative acts on $X^a$ as scalars, or do we include connection coefficient terms?  To clarify, consider $$ \nabla_X Y = X^a \nabla_a(Y^b e_b) = X^a (\nabla_a Y^b) e_b + X^a Y^b (\nabla_a e_b) = X^a (\partial_a Y^b) e_b + X^a Y^b \Gamma^c{}_{ba} e_c $$ As you can see, when the covariant derivative acts on the $Y^b$, it acts as a simple partial derivative, since the $Y^b$ are here considered functions premultiplying the vectors $e_b$.   However, in this equation from  page: $$(\nabla_X \nabla_Y Z)^a = X^c \nabla_c Y^b \nabla_b Z^a = X^c Y^b \nabla_c \nabla_b Z^a + (X^c \nabla_c Y^b) \nabla_b Z^a = (\nabla^2_{X,Y} Z)^a + (\nabla_{\nabla_X Y} Z)^a$$ When the covariant derivative acts on the $Y^b$ term it treats it like a vector.  What's going on here? Thanks. Is it posible to add iframe directly in lightning components? Is it possible to add iframe directly in a lightning component as below to visible in community sites ?  &lt;aura:component implements="forceCommunity:availableForAllPageTypes" access="global" &gt;     &lt;iframe width="800" height="600" style="border: 1px solid" src="---" /&gt; &lt;/aura:component&gt; in my earlier question you can find at:   i describe my error:     I'm using an Asus Zenbook UX562F with an integrated GTX 1050 Max-Q.   After the installation, I installed Nvidia-390 and updated the kernel   with ukuu to 4.20.17 to fix no sound issue.      After the reboot, everything went well and I did:      apt-get update apt-get upgrade + J      All was done well, so I restarted and on the next boot after selecting   Ubuntu in GRUB it gave me a long black screen (violet screen) where   nothing changes after so much time.      I tried to add nomodeset and noveau.modeset=0 single and together but   didn't help so I don't know what to do.   After investigating deeper by installing packages and try to boot i found out that the package which is causing the error is:  intel-microcode   when i purge and block this package with:  sudo apt-get purge intel-microcode sudo apt-mark hold intel-microcode   before upgrading wuth  sudo apt-get upgrade   my system is able to boot normal.  The problem i see is that as i understand it the package protects my intel cpu  Intel® Core™ i7 8565U 1.8 GHz   is vulnearable to meltdown attacks which get fixed by the package.  What can i do to fix the vulnearbility and also get my system to a bootable state?  Thanks for your help Vimu  Edit: I used the manual update technique mentioned at (in german):    and i used the files from the intel github repo:    with the following code mentioned in the tutorial to update the firmware microcode files  sudo cp intel-ucode/06-8e-09 /lib/firmware/intel-ucode/ echo 1 | sudo tee /sys/devices/system/cpu/microcode/reload   i overwrote the old microcode firmware with the newest available on the intel repo  it leada to a bootable system  will this be the best possible fix without upgrading the intel-microcode package provided by apt? I am trying to list all the files from dir1, dir2, dir3 and dir4 which might be anywhere in as a sub directory of my cwd using the find command. I tried the following with no success:  find . -type f -regextype posix-egrep -regex 'dir1/.+|dir2/.+|dir3/.+|dir4/.+'   I tried posix-extended as well. How can I list these files? save as a video as .mp4 So I made an intro using animation and it saves it as a .blend and I want it so save as a video like .mp4 or something like that. I've tried changing the codec because I tried opening the intro with windows media instead of blend. I didn't try all the codec's but I tried some of them. How SELECT column does not list in GROUP BY clause The query:  select year,sum(mark),sum(maxmark)  from table1  group by parameterno   yields an error message:     Column 'table1.year' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. Parse DateTime with time zone of form PST/CEST/UTC/etc "Open in Terminal" in Ubuntu 18.04 This option seems to have gone away after upgrading from Ubuntu 16.04. I tried installing nautilus-open-terminal but it is unable to locate the package for 18.04. Also trying to install nautilus-actions gives:  Package nautilus-actions is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source     How to fix this? Update from 14.04 to 16.04 failed with GPG error How can I create an Excel spreadsheet with C# without requiring Excel to be installed on the machine that's running the code? Sci-fi book, blue critters than only some people can see, kids fight the critters as they feed off energy and are a threat Prove that if $a^2 = a$ for all elements of the ring $R$, then $R$ has characteristic 2. Is the converse of the statement true?  Attempt:  by the definition of characteristic of a ring, the first statement implies that characteristic of the ring is $\leq 2$. If the ring is assumed to be non trivial ring then, characteristic is 2.  About the last statement can we construct a field of say 8 elements and show that there exists a an element of order $\neq 2$?  Is there a simpler example ? UV Maps not showing in render I can not add all the images because the account is new and I don't have enough reputation.  I have an object (a tube of a cream) with three diferent materials, the base "plastic" material and I have created two separated materials to add the front and black labels to the tube.  The front and back label materials is the same as the "base material" but I'm trying to overlay the PNG image on top of it.  For doing that I have unwraped the parts of the object where the labels should go and placed the islands on top of the image.  I have created separated UV Maps for that purpose.     On the viewport view everything seems ok: As you can see the texture is correctly placed.   Render / Rendered view unexpected output: When rendering or in the rendered mode of the viewport the material with the UV Map appears as black.   Material nodes: For further info in case it's needed here are the screencaps of the material of the front label:        How can I solve this? Thank you! Obviously, this suggested edit should never have been approved. Because it's very, very minor.  Is it acceptable for me to "rollback" this edit? Does the suggested editor lose the +2 rep when I roll it back? Should I comment on one of his questions, explaining not to make too minor edits like this?  Is there anything I should do to notify the reviewers that approved  too minor suggested edit? I've updated my Ubuntu to 19.10 couple of weeks ago and on installation system suggests to change or add shortcut for input source selection despite one was already defined previously. I've added ctrl+shift shortcut and just realized that it somehow overlapped any other ctrl+shift+something shortcuts globally, i.e. when I want to open new window in vscode, it opens new tab and it looks like system doesn't see the shift button press.   I tried to search this combination in shortcuts settings, but it's just not there. How to make traditional output for derivatives Show that every monotonic increasing and bounded sequence is Cauchy. I have installed Ubuntu Server on an old desktop, and I'm new to this.  I had set it up and was trying to connect through Putty but that was not working.  When I tried ifconfig there was no eth0 IP address, and logging onto the router showed the only device connected by ethernet is the printer.  However, the ethernet cable is plugged into the server and is showing the green light by it.  I tried opening /etc/networking/interfaces but this shows the following:  source /etc/network/interfaces.d/*  # The loopback network interface auto lo iface lo inet loopback   I tried adding 'auto eth0' after this and saving but made no difference, and have tried sudo ifconfig eth0 up which didn't do anything either.  sudo lshw -C network says that the network is DISABLED.  Any ideas to help get this up and running?  EDIT: Running command lspci -knn | grep Eth -A3 results in the following:  02:05.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL-8110SC/8169SC Gigabit Ethernet [10ec:8167] (rev 10)          Subsytem: Gigabyte Technology Co., Ltd GA-MA69G-S3H Motherboard [1458:e000]          Kernel driver in use: r8169          Kernel modules: r8169 JavaScript editor within Eclipse