It always defaults to 32bit. I'm totally new to ubuntu, but willing to learn this OS. Should have used it many years ago.....
What is the difference between standard i386 download and the amd64 download of Ubuntu 11.04? I am currently running the i386 on an amd machine, would my system work better with the amd64 download instead? (my machine was running Windows 7 64bit, but I neglected to look at that prior to installing Ubuntu).
Why is it bad to log in as root? I've often come across posts on forums or other websites where you see people joking in such a manner about running/logging in as root as if it's something awful and everyone ought to know about it. However, there isn't much that a search reveals on the matter.   It may be widely known to Linux experts, but I really don't know why. I remember always running as root when I first tried Linux years ago (Redhat and Mandrake) and don't remember running into any problems because of that.   There are actually some distros that have a bright red background with alert signs all over it as wallpaper for the root user (SuSe?). I still use the "Administrator" account for regular use on my Windows installation and haven't ever run into any problems there either. Why are my render times 30+ minutes, but other people's are ~3 minutes? I am currently using Sheep It! to render my blend (built on v2.68c) on multiple computers, and I noticed something rather strange. According to the log on-site, the frames rendered from other people's blends were completing in 3 to 4 minutes. This was on an 4 core i5. My main rig (with an 8 core i7) was completing frames in no less than half an hour. How is this possible?  To clarify, these people's frames are very complex, often with very detailed textures. I have 2 objects in my blend. Below are the options I changed for my blend:   Aspect Ratio: 1000px x 1000px Output: PNG Clamp Indirect: 0.98 Render Sampling: 128 Min Light Bounces: 0 Max Light Bounces: 4 Cycles Render   Is there something in there that I should change to make it go faster? I can't really comprehend how it's going to quickly.  EDIT: To answer what @Duarte asked...   System Specs: i7-920, 3GB DDR3, GT 630, Windows 10 I have two circles, extended to form a sort of coin with a star on it. It is not complex at all. I have Firefox and Steam running in the background, but not actively. I've been away from the computer for 8 hours and noticed this behavior. (I am running Blender from Steam.) I made sure when I began rendering that the blend was set for CPU rendering.          And to answer what @pycoder asked, yes, I am using Cycles Render. How to represent it with UNIQUE indexes and foreign keys? How come the year doesn't show here? I know that if we solve the Maxwell equation, we will end up with the phase velocity of light being related to the permeability and the permittivity of the material. But this is not what I'm interested in - I want to go deeper than that. We know that the real speed of light is actually not changing, the decrease in speed is just apparent. Material is mostly empty, the light will still travel with $c$ in the spacing. The rare atoms will disturb the light in some way. So I am interested in how the atoms affect the light. Photon absorption-emission theory Some textbooks that I read explain it in a way kind of like this: In a material the photons are absorbed by atom and then re-emitted a short time later, then they travel a short distance to the next atom and get absorbed&amp;emitted again and so on. How quickly the atoms in a material can absorb and re-emit the photon and how dense the atoms decides the apparent speed of light in that material. So the light appears slower because it has a smaller “drift speed”. Interference theory But recently I realize an alternative explanation: Atoms respond to the light by radiating electromagnetic wave. This “new light” interferes with the “old light” in some way that results in delayed light (advanced in phase), this can easily be shown by using simple phasor diagram. Consequently effectively the light covers a smaller phase each second, which gives the impression of a lower phase velocity. However the group velocity is changing in a complicated way. I think that the first explanation does not explain the change in phase velocity of light. if we consider light travelling into a slab of negative refractive index non-dispersive material, let’s say the light is directed perpendicular to the slab. The phase velocity’s direction will be flipped, but group velocity’s direction in the material will not change. Only the second explanation can explain the flipped phase velocity direction. I guess that the velocity that we get in the first explanation is actually belongs to the group velocity. It makes sense to me that the front most of the photon stream determines the first information that the light delivers. So the question is What really cause the phase velocity of light to be decreased?  &quot;drift velocity&quot; of photons (they aren't the same photons, they are re-emitted all the time) phase difference between absorbed and emitted light something else  And also, I still don't really understand detailed explanation of the absorption-emission process for small light's wavelength (for large lambda compare to the atoms spacing, the photons will be absorbed by the phonons). The dispersion relation that we know is continuous and also some material is non-dispersive, therefore the absorption process must occur in all frequency for a certain range. So definitely it doesn't involve the atomic transition, otherwise it will be quantized. My guess is that the relevant absorption process gets smooth out by the dipole moment. What makes the spectrum continuous? EDIT: link for dispersion relation: I have a directory with ~1M files and need to search for particular patterns. I know how to do it for all the files:  find /path/ -exec grep -H -m 1 'pattern' \{\} \;   The full output is not desired (too slow). Several first hits are OK, so I tried to limit number of the lines:  find /path/ -exec grep -H -m 1 'pattern' \{\} \; | head -n 5   This results in 5 lines followed by  find: `grep' terminated by signal 13   and find continues to work. This is well explained . I tried quit action:  find /path/ -exec grep -H -m 1 'pattern' \{\} \; -quit   This outputs only the first match.  Is it possible to limit find output with specific number of results (like providing an argument to quit similar to head -n)? Evaluate trigonometric function Maybe the concept, why it's used, and an example. Selecting through one-to-many relationship I'm trying to make a species distribution project where I can select a species from a non-spatial list of species and the selection would highlight (select) all the counties to which the species has been attributed.  Simplified example data: species, a non-spatial table of species (CSV with header): "species" "Mus borealis" "Mus australis"  species_distributions, a non-spatial relation table (csv with header): "species","county" "Mus borealis","North" "Mus borealis","Central" "Mus australis","South" "Mus australis","Central"  counties, a spatial feature class representing county boundaries (first row = field name): "county" "North" "South" "Central" "West"  So if I select "Mus borealis" from the species table, the "North" and "Central" counties would be highlighted in the map. Seems like a simple scenario, but I have been unable to uncover a solution on my own. The closest I've found is a plugin "Select by relationship" but it doesn't appear to be available for QGIS 3 (I'm using QGIS 3.4.3). I have a PostGIS server available. How do I install the latest stable version of LibreOffice? LibreOffice is seeing some dramatic improvements each version and subversion that goes out.   I would like to have always the latest version of LibreOffice on my machine(s). I know of the PPA that exists but is it recommended to use it with 12.04 for daily use? What are the pro and cons of using the PPA? Will it break my system/Libreoffice installation?  Does libreoffice get eventually also upgraded in the Ubuntu repositories or does this upgrade happen only with new releases? Who manages the upgrades of libreoffice in Ubuntu and in the PPA? I would like to convert a Mp4 file in HD into a Mp4 file of lower resolution. Is there any software that can be used for this? I was going to make a filter for the &quot;&quot; by excluding some sites from it.  I noticed  which talks about &quot;negative filtering&quot; but does not explain how one can do it or if it is possible.  There does not seem to be a way to do this, though.  On the filter page, my only options are:  So how can I do &quot;All sites except [list]&quot;? It would also be nice if this could include similar functionality with the meta checkbox.  Something like &quot;All main &amp; meta sites except...&quot; Determinant of a special $n\times n$ matrix Reputation for graph is off by a day So when we view reputation, there is graph view. However, it seems to be off by a day. Here's what I mean:   I'm sure 70 + 20 + 15 is not 15. Its 105, which is what we see below:   And 40 + 10 is NOT 105, unless you did  :)     Anyways 40 + 10 is 50:   So yeah. Did you do what that post on codegolf says? Devs better fix that :) How to install HPLIP on my Ubuntu to support my HP printer and/or scanner? Let's assume that one has some HP printer and/or scanner and checked its support status on the corresponding page of HPLIP site - .  So one have the following information: the device Model name, Min. HPLIP Version and Driver Plug-in need.   What should one install to make Ubuntu fully support the HP printer and/or scanner? How to safely remove proprietary Intel driver I recently installed the proprietary Intel drivers for my Toshiba Satellite A105 s4284 running Ubuntu 14.10. Nouveau was working just fine, I was just attempting to make it so that I was able to run CS:S (no need for explanation on that.)  Long story short, I went and downloaded the Intel Graphic Drivers for Linux* from . After downloading and installing the .deb, I ran intel-linux-graphics-installer which opened up a window that downloaded &amp; installed the open Intel drivers. I then rebooted, and it's slow. Very slow, especially on 3D effects and when I hit Alt+Tab.  Now, I don't know if the previously installed Nouveau drivers are conflicting with these new Intel drivers (if that's the issue, what should I do about fixing it?) What I do know is that my system isn't behaving right and I want it to (obviously.) If removing the Nouveau drivers isn't the solution, how can I safely remove the just-installed Intel drivers?  Does anyone have any suggestions? What is the cardinality of the set of all topologies on $\mathbb{R}$? This was  on Quora. I thought about it a little bit but didn't make much progress beyond some obvious upper and lower bounds. The answer probably depends on AC and perhaps also GCH or other axioms. A quick search also failed to provide answers. How to find windows 10 activation Key Where can it be find?  At activation panel i can only find option to change the activation key. The current key is not presented on this screen. Can I store the .git folder outside the files I want tracked? I have an unusual idea to use git as a backup system. So let's say I have a directory ./backup/myfiles and I want to back that up using git. To keep things clean I don't want to have a .git directory in the myfiles folder, so I thought I could create ./backup/git_repos/myfiles. From looking at the git docs, I've tried doing this:  $ cd backup/myfiles $ mkdir ../git_repos/myfiles $ git --git-dir=../git_repos/myfiles init Initialized empty Git repository in backup/git_repos/myfiles/ $ git --git-dir="../git_repos/myfiles/" add foo fatal: pathspec 'foo' did not match any files   You can see the error message I get there. What am I doing wrong? When I press Ctrl+Alt+T the Terminal opens after around 30 seconds. That's pretty annoying. If I open it with Alt+F2 and enter gnome-terminal the window appears instantly as usual.  I'm using Ubuntu 16.04 with gnome3.  Thank you for your help in advance!