Ubuntu 18.04 opening system settings logs me out When opening system settings on a clean installation of Ubuntu 18.04 I get logged out. It happens if I open it from the launcher, from the menu or from the terminal with gnome-control-center (even with sudo). This is funny as I installed 18.04 on two "identical" machines, and one has the issue while the other one does not... any idea what might be going wrong here? Thanks!
Ubuntu 18.04 opening system setting logs me out I've recently installed Ubuntu 18.04 in a dual-boot configuration with Windows 10. I noticed today that, when trying to open system settings, Ubuntu seems to log me out to the lock screen. When I log back in, all previously-running applications are now closed. Very unsure what to do from here, any help much appreciated.
Do we use the SD of whole population or SD of just one sample to calculate SE of samples means in central limit theorem? I'm learning applications on Central Limit Theorem and got really confused with a few points. According to this , the procedure to apply CLT usually goes like this:   So if SD is the population standard deviation, how are we gonna get it?? Isn't the whole population standard deviation what we eventually calculate by applying CLT and analyzing a sample of the whole population? How come the population standard deviation become a prerequisite??   Please tell me this tutorial is wrong.   I think the SD actually refers to the standard deviation of a sample (of some size n), which we can actually get easily. For example:    sample the whole population with a sample size of n (e.g. randomly select 10000 users from the whole population of 10 billions) calculate the mean of the 10000 measurements. calculate SE = SD / sqrt(10000), where SD is the standard deviation of the 10000 measurements, instead of the standard deviation of the whole population of 10 billions.    This explanation would make much more sense.   Any thoughts? Custom blocks created as a plugin in a module not showing for Block::load() I have a couple of blocks that have been created using the ... extends BlockBase syntax in my module. They work perfectly fine, and I can add them on the blocks layout page, can add them into DS as a field, etc. They definitely exist fine.  However, when I try and render them using Block::load(), they won't show up, unlike other blocks that work fine.  For example, if I have the following docblock:  /**  * Provides a 'Cute Cats' Block.  *  * @Block(  *   id = "cute_cats",  *   admin_label = @Translation("Cute cats yo"),  * )  */  class CuteCats extends BlockBase { ... }   ... and then try and call it like this:  $block = \Drupal\block\Entity\Block::load('cute_cats'); return render(\Drupal::entityTypeManager()   -&gt;getViewBuilder('block')   -&gt;view($block));   Any idea why? Thanks in advance. "Whom" or "who" where the referent is both subject and object? I understand there has been so much on this topic but I am still confused. I get that if the person is the subject it is who and anything else is whom. However, I'm really struggling to work out this rule for the following sentence:     The scope of which his account of morality applies to is therefore restricted to those whom/who the ‘notion of justification to a being of that kind makes sense.’   Should it be who or whom? I can't work out the subject and object. I frequently login to a server, then cd into a specific directory. Is it possible to simplify these two commands into one?   ssh bob@foo   cd /home/guest   I'd like to avoid changing anything on 'foo' if possible, as I'll have to clear it with the server administrator. I use bash, but I am open to answers in other shells. An "urgent" tag for questions that need answers within minutes Reclassifying raster layer with certain colors for value ranges in QGIS? I'm using QGIS. I want a raster layer with 6 different colors each color representing a certain value range (e.g. -1 to 0 red, 0 to 0.2 orange).  In the layer style menu I can only approximate colors. How to secure my laptop so that hacking by physical access is not possible? Do we have $\lim_{h\to 0^+}\int_0^\infty|f(t+h)-f(t)|dt=0$? Let $f:\mathbb{R^+}\to\mathbb{R}$ be an integrable function ($f\in L^1(\mathbb{R}^+,\mathbb{R})$). Do we have $$\lim_{h\to 0^+}\int_0^\infty|f(t+h)-f(t)|dt=0$$ ? How can we prove it ? I'm trying to change the numbers in problems I write for examples I use in my class as well as assignments. However the problems are still inspired by the textbook. Are the problems sufficiently different from the textbook problems to not have copyright issues? There is also an issue of theorems and definitions. Authors of the calculus textbook certainly did not come up with these things. Is it OK to just copy them down in my lecture notes?  By the way I do share my lecture notes on Piazza and the course I'm teaching is multivariable calculus. Photons have no mass but they can push things, as evidenced by .   Can photons push the source which is emitting them? If yes, will a more intense flashlight accelerate me more? Does the wavelength of the light matter? Is this practical for space propulsion? Doesn't it defy the law of momentum conservation?  Note: As John Rennie mentioned, all in all the wavelength doesn't matter, but for a more accurate answer regarding that, see the comments in  .  Related Wikipedia articles: , I'm reading a lot of documentation on sed, and am still stumped on my particular use case.  I want to replace this line in a conf file with my own line:  Replace this line: #maxmemory &lt;bytes&gt; with: maxmemory 26gb  This is what I tried:  sed s/maxmemory.*bytes.*/maxmemory 26gb/ /etc/redis/redis.conf  I get the error: sed: -e expression #1, char 30: unterminated `s' command  Which stumps me because I don't know what that means. So my question is:  How can I accomplish what I want? What does that error mean? (so I can learn from it) How can I tell if sheet a exists in a workbook? I have the following code that's not working as expected:  If Sheets("a") &lt;&gt; "" Then MsgBox ("sheet a exists")   How can I tell if sheet a exists in the workbook? Product of elements of a finite abelian group Suppose $G=\{a_1,...,a_n\}$ is a finite abelian group, and let $x=a_1a_2\dotsm a_n$.   Prove that if there is more than one element of order $2$ then $x=e$.   What I've done so far: (#1 is just for illustration, There should be at least $3$ such elements)   $G$ has an even number of elements with order $&gt;2$ (They are paired so: $(a,a^{-1})$ ). And then there are $e$ and $\{b|o(b)=2\}$. Also, if $G$ has at least one element of order 2 then $|G|$ is even (Lagrange). Thus $|\{b|o(b)=2\}|$ must be odd. If there is exactly one element $b$ of order $2$ then $x=b$. That's because $G$ is abelian, and we can write: $x=e\cdot b\cdot(a_1 a_{1}^{-1}\dotsm a_n a_{n}^{-1})=b\cdot(e\dotsm e)=b$. If there are exactly $3$ such elements $a,b,c\in G$, then, as shown above, $x=abc$ and thus $x=e$ (That's because $(abc)^2=a^2b^2c^2=e$ which means $abc\in \{a,b,c,e\}$. If $abc=a$ then $b=c^{-1}=c$ which is false, same goes for $abc=b,abc=c$.)   I haven't managed to find a reason why the claim must hold for $5, 7, ...$ (i.e. All other odd integers). Does anyone have an idea?  Thanks in advance. Please excuse my English.  edit: Not a canonical answer but a simple one (if such even exists). In this  of Harvard, it is proved that Mandelbrot set is connected, a result due to Douady and Hubbard. However, I lack necessary knowledge to comprehend it. Then in the same note it is said that the simply connectedness of Mandelbrot set is easier to prove.  However, I cannot find a proof through google. Can anyone provide me a reference or a proof of the simply connected of Mandelbrot set? Compute the integral $\int\frac{dx}{(x^2-x+1)\sqrt{x^2+x+1}}$ What is a feminine version of 'guys'? I commonly use the word 'guys' to refer to a group of males colloquially. It's colloquial but not rude, off putting, condescending, patronizing (though I wouldn't use it with a group of men at a board meeting (hypothetically of course), unless I knew them). So, some that I would not consider as replacements would be    buddies: too old-fashioned dudes: too informal boys: too patronizing men, gentlemen: too formal or false respect   I realized that I had also been using it for any group of people, males and females, even just females. It worked for me and I didn't think of the gender implications, that women might not care for it. No one ever complained, directly or indirectly (rule of life: sometimes people don't complain about things they should).   But it occurred to me (maybe by reading something that sparked realization) that the intended hearers might not all care for it.  What might be a female gendered or non-gendered version of 'guys'?  Some that I've considered don't feel right about (though these may be reasonable answers) are:   dolls: too old-fashioned babes: too informal  ladies: too formal or I've heard from women, too creepy women: too factual girls: too patronizing (as much as 'boys') everyone, you all: too bland y'all: perfectly non-sexist but too regional (might work, but not everywhere)   Hopefully I haven't eliminated all the possibilities -- any suggestions? (This question is meant to be a resource to direct others to given that this is a common question.)  Given the task of creating an image that will be printed at a certain size, what pixel dimensions and resolution should I be setting my file at? For the recently reported production (January 2017) of metallic hydrogen in the laboratory - what is the evidence exactly? My google news page has burst forth the news that metallic hydrogen has been produced in a laboratory using a diamond anvil cell. Only  mentions (at this particular moment) that it has been called into question at - at least - premature. That can be read about in Nature:   Here I only want to ask about the evidence. Is it only the sudden change in visual appearance change as recorded in a camera on top of the microscope, at a specific temperature and pressure? That it "looks shiny?" Or is there actually more direct data than that?  note: I am not asking if the data is sufficient or not, nor if it is convincing, or metallic or not. Just a narrowly defined question about the extent of the observations that have lead to the proposal that a metallic state was achieved.     above: potentially three states of hydrogen as viewed in a diamond anvil cell, from . \hfill \break does not work Currently look after 3 websites. I changed one of them to be HTTPS as it's ecommerce, however have seen a huge drop in organic traffic since this was implemented. Went from around 800 impressions to 400.   Any ideas as to why?   Very concerning as I expected it to improve if anything!  I set up 301 redirects to carry through to old pages to http://www.example.com/product1 would go to https://www.example.com/product1  I also set up a separate webmaster account for the HTTPs version as our integration wasn't working well with Google Merchant Centre, and data is flowing correctly but unsure why/if this would cause conflict.  Very confused!