My cpu overheats when rendering
How to configure blender so that it uses only 50% of total CPU when rendering?
Why is Facebook PHP SDK getUser always returning 0? I run sudo apt-get install git-all in Ubuntu 16.04 and see the following in the end  Setting up runit (2.1.2-3ubuntu1) ... start: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                       Errors were encountered while processing:  runit  git-daemon-run E: Sub-process /usr/bin/dpkg returned an error code (1)   I get the error after rebooting my system also. It really blocks my whole system.  I run killall update-notifier. I run sudo apt-get install git-all but  I get the same error message. I run pgrep -a apt but get nothing as output. I run pgrep -a update but get nothing as output.  A bug report about the case .    In Grub, Choose Advanced options > Ubuntu (Upstart) Linux kernel 4.22. Doing the same only in terminal without systemd causes the same error.      Why is this error here with runit? Your Mileage May Vary In the United States we have a saying, "your mileage may vary", which means "your experience may be different".  In English-speaking countries that don't use Imperial miles, is there an equivalent expression? Is it possible to simulate key press events programmatically in JavaScript? What is taking up so much space on my disk, beside the filesystem? I have only one disk in my computer, a 80 GB SSD. It is formatted as a single ext4 partition (no swap), and all the usual folders are installed on it (I keep lots of data on external media, but /home and all the rest is on the SSD).   Today I booted it and I got a message that the drive is full. I opened Disk Usage Analyzer to look at what takes up space. It insists that 67.8 GB of the disk are used, and that / is taking up 36.4 GB. Which leads to the question, where are the missing 30 GB, if not on the file system?!    Just to have a comparison, I added up all the sizes of all readable folders listed in Nautilus as subfolders of / (including the hidden ones). I got 20.9 GB. Trash was unreadable, but I know it has 16.2 GB, so the sum is 36.1 GB, around the same as what Disk Usage Analyzer is reporting. There were some system folders which were unreadable, like proc, but I doubt that they add up to 30 GB - else it wouldn't be possible to install Ubuntu on small disks, and I've seen it run on 2.5 GB. I think they must be the 0.3 GB difference between my calculation and the Disk Usage Analyzer's report.   So I'd like to know, what is eating up these 30 GB and how do I get it to free them?     Edit with answers to CYREX's questions   Booted from Ubuntu 10.10 64-bit live CD (same as my system).  fsck result:   root@ubuntu:~# fsck /dev/sda1 fsck from util-linux-ng 2.17.2 e2fsck 1.41.12 (17-May-2010) /dev/sda1: clean, 265956/4890624 files, 18073343/19537408 blocks  Booted from the SSD. Emptied the trash, and the 16 GB from there are now free. The 30 GB are still missing.    I'm not experienced enough to know what counts as weird in a log. Here are my messages log and my syslog since last boot. Maybe you can find something in them:       Here it got really strange. I plugged in an external 500 GB HDD. Disk Usage Analyzer overreported the available space, then showed space missing (76 GB used, but only 24 in folders).      Booted again from the LiveCD, started the Disk Usage Analyzer from it and got the same results as from the installed Ubuntu, within 1-2 GB.   Edit with answer to CodeMonk:  That would have been a nice solution, but the partition is really 80 GB - I mean 74 GB + marketing "error", anyway the whole disk is formatted. It also shows that over 50 GB are used, so where are the 30 GB if not in files and folders?    GParted also reports the correct size of the external HDD. Proving that the general linear group is a differentiable manifold We know that the the general linear group is defined as the set $\{A\in M_n(R): \det A \neq 0\}$. I have a homework on how to prove that it is a smooth manifold. So far my only idea is that we can think of each matrix, say $A$, in that group as an $n^2-$dimensional vector. So i guess that every neighborhood of $A$ is homeomorphic to an open ball in $\mathbb{R}^{n^2}$ (However, i don't know how to prove this.)  Now, I'm asking for help if anyone could give me a hint on how to prove that the general linear group is a smooth manifold since I really don't have an idea on how to do this. (By the way, honestly, I don't really understand what a $C^{\infty}-$smooth structure means which is essential to the definition of a smooth manifold.) Your help will be greatly appreciated. :) Community user id interpreted by absolute value in search How to completely disable the Windows taskbar? I've installed Taskbar eliminator, while it works most of the time, alerts being the taskbar back.  I've also installed object dock which can disable the taskbar, object dock appears during window changes.   Has anyone had any luck permanently removing, hiding the taskbar in Windows 7?  Update  I found an application that seems to be working here:    Second update  I took the leap and installed a shell replacement (). So far so good. Is centripetal acceleration mandatory for circular motion? I came across this problem when I was at a book store inside of a book made to prepare Berkeley graduates to pass a mandatory exam. I wanted to buy the book, but, alas, I didn't have the money (forty bucks is a lot of money when you don't have a job). So I took my phone out and started taking as many pictures as I could. Unfortunately, I didn't take any pictures of the solutions!  Enough backstory. Time for math. The problem is as follows:  Prove that $\cos^p( \theta) \le \cos(p \theta)$ if $0\le\theta\le\frac\pi2$ and $0\le p\le 1$.  I tried using the series expansion for cosine, but that seemed to be a dead end. Then I tried using Euler's theorem, but I got stuck. Then I got distracted and started to think about other cosine identities. For example, $$\cos\left(\frac\theta2\right)=\pm\sqrt{\frac{1+\cos(\theta)}{2}}.$$ Then what is $\cos(\frac\theta3)$ equal to? I tried to figure it out then I realized that I needed to find the root of a cubic polynomial. Then I realized that I'm better at staying focused than finding the roots of cubic polynomials.  Anyways, a proof would be nice here. I really appreciate any hints or answers. I apologize for my digressions! How can one securely generate an asymmetric key pair from a short passphrase? Background info: I am planning on making a filehost with which one can encrypt and upload files. To protect the data against any form of hacking, I'd like not to know the encryption key ($K$) used for a file, so the user will have to asymmetrically encrypt $K$ and send it as well. The reason for this double encryption is that you can still share (individual!) files with other accounts by encrypting $K$ with the public keys of those users, too.  My problem is: How can a user can get a public and private key without the server saving/knowing the private key and without the user having to remember a passphrase of 250 hex characters?  Question: Is there a way to derive a key pair from a password, like PBKDF-2 does for symmetric encryption? Suggestions on rearranging the cryptographic steps in an easier way are welcome, too.  Alternatively: It is also possible to encrypt the private key with a PBKDF-applied password and store it on the server, but I'd like to keep things 'simple'. ;)  Note: At this point I don't care if it requires RSA, ECC or an obscure cryptography scheme. How do I add a border around windows but keep the current theme? I seem to live my life in the terminal - many terminals in-fact.  I also love the Ambiance theme - but the new borderless windows does not provide the visual differentiation I'm used to (the same black windows appear to blend into each other).    Thus to my question - how do I add back the single pixel border for windows that is found in earlier Ubuntu versions?  I want to keep the Ambiance overall theme since this looks good and I dont want to swap to another theme.      Now I know that I can modify the Ubuntu Ambiance theme as follows:  mkdir ~/.themes cp -r /usr/share/themes/Ambiance .themes   Then flipping between the theme options in the Settings - Appearance picks up changes in the theme in now in the .themes folder.  I presume I need to alter one of the .css files but I dont know which one.  I was also looking at  but the solutions there doesnt work for 14.04.  I also looked at the  but got rather lost trying to figure out which one applies to my situation. Interchanging the order of differentiation and summation The story is basically told from an alien's point of view. Essentially they observed us from far off, deemed us as violent and a danger to the universe, and set course (asteroid or something) to kill us. They kept observing and saw all the art and beauty we created and realized we were actually not so bad, but by then they couldn't stop it. So it was sort of also an apology letter to Earth in the end.  First read it like a year ago online and I can't find any trace of it anymore, nor can I recall the site it was on. Anyone know what short story this is? A question about a primitive root mod $p=2^{2^k}+1$, where $p$ is prime. Local SEO Strategies What are your strategies for local SEO? For example, if you had a web design company in Lincoln, Nebraska, what would you do for your website from an SEO perspective? The spells that we know about in the Harry Potter world all seem to be either in Latin, derived from Latin, or resembling Latin.  This makes sense for the European World, but there were likely witches and wizards in Africa, Asia, and the Americas.  These cultures would have developed independently, and the magical people in them would likely have still found ways to cast their spells.  Do cultures with languages that did not derive from Latin use the same words and phrases that are related to Latin for their spells?  Or did they have other phrases based on the languages in their cultures? How do I add a directory to the $PATH in Ubuntu and make the changes permanent? Please have a look at this sentence:     We haven't gotten a lot of Finnish groups that we liked here at Bananas but I'm pretty happy with this four tracker from Helsinki, apparently recorded in the same place where the Ramones played in the 70's.     The first verb is in present perfect (up to now) and the second is in simple past tense. I don't understand the simple past for the second verb.  Why "like" is not in its present perfect form as the first verb is? This time when I used certbot it created a certificate for "www.$website" instead of $website. This is not what I need.  Here it is:    $ website="my_website123.com"   $ sudo certbot certonly --standalone -d $website -d www.$website --email admin@$website              Saving debug log to /var/log/letsencrypt/letsencrypt.log   Plugins selected: Authenticator standalone, Installer None   Starting new HTTPS connection (1): acme-v01.api.letsencrypt.org   Cert not yet due for renewal    You have an existing certificate that has exactly the same domains or certificate name you requested and isn't close to expiry.   (ref: /etc/letsencrypt/renewal/www.my_website123.com.conf)    What would you like to do?   -------------------------------------------------------------------------------   1: Keep the existing certificate for now   2: Renew &amp; replace the cert (limit ~5 per 7 days)   -------------------------------------------------------------------------------   Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2   Renewing an existing certificate   Performing the following challenges:   http-01 challenge for my_website123.com   http-01 challenge for www.my_website123.com   Waiting for verification...   Cleaning up challenges    IMPORTANT NOTES:    - Congratulations! Your certificate and chain have been saved at:      /etc/letsencrypt/live/www.my_website123.com/fullchain.pem      Your key file has been saved at:      /etc/letsencrypt/live/www.my_website123.com/privkey.pem      Your cert will expire on 2018-10-18. To obtain a new or tweaked      version of this certificate in the future, simply run certbot      again. To non-interactively renew *all* of your certificates, run      "certbot renew"    - If you like Certbot, please consider supporting our work by:       Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate      Donating to EFF:                    https://eff.org/donate-le   Why did it create one for "www" instead of the bare domain?   On all my own servers this exactly command has always created a cert. without "www" - this is what I need. I even tried yesterday on a different server -- without "wwww".  How can I make it create a cert. without "www"?