I know the difference between "made of" and "made from", but could you help me choose which one I should use in the following sentence?      This house is made of (or) from mud bricks
An English book tells me that the following sentence is correct:     This publication is made from paper from sustainable forests.   Shouldn't it be of paper instead?
Help me understand Bayesian prior and posterior distributions In a group of students, there are 2 out of 18 that are left-handed. Find the posterior distribution of left-handed students in the population assuming uninformative prior. Summarize the results. According to the literature 5-20% of people are left-handed. Take this information into account in your prior and calculate new posterior.    I know the beta distribution should be used here. First, with $\alpha$ and $\beta$ values as 1? The equation I found in the material for posterior is   $$\pi(r \vert Y ) \propto r^{(Y +−1)} \times (1 − r)^{(N−Y +−1)} \\ $$  $Y=2$, $N=18$  Why is that $r$ in the equation? ($r$ denoting the proportion of left-handed people). It is unknown, so how can it be in this equation? To me it seems ridiculous to calculate $r$ given $Y$ and use that $r$ in the equation giving $r$. Well, with the sample $r=2/18$ the result was $0,0019$. The $f$ should I deduce from that?  The equation giving an expected value of $R$ given known $Y$ and $N$ worked better and gave me $0,15$ which sounds about right. The equation being $E(r | X, N, α, β) = (α + X)/(α + β + N)$ with value $1$ assigned to $α$ and $β$. What values should I give $α$ and $β$ to take into account prior information?  Some tips would be much appreciated. A general lecture on prior and posterior distributions wouldn't hurt either (I have vague understanding what they are but only vague) Also bear in mind I'm not very advanced statistician (actually I'm a political scientist by my main trade) so advanced mathematics will probably fly over my head. How do I change text on the submission button in the node form? In computer science we discuss an abstract machine called a "deterministic finite automaton". The standard initialism for this term is "DFA". This makes sense in the singular usage of the initialism.  However, the pluralization of the word "automaton" is "automata". One speaks of "an automaton" or "many automata". Consequently, it seems intuitive to form an initialism of the phrase "deterministic finite automata" as "DFA".   This does not seem correct, as "DFA" could be either plural or singular. On the other hand, "DFAs" also does not seem correct because it would seem to expand to "deterministic finite automatons", a phrase which no self-respecting computer scientist would ever utter.   This appears to be a duplicate of the question here   But that question was never clearly resolved. What to do? What is the distance between the centers? Two unit circles overlap in such a way that exactly half the area of each circle is within the overlap. How far apart are the centers of the two circles? How do airlines determine ticket prices? How is electricity wasted? All i know is electric current travels in a loop. So how / where in its way does electricity (electric energy) get wasted?  And what do we do on switching electric appliances off? If it's not electric current that is wasted then what is it? Do cell carries have access to FaceTime information? On the newest iPhone, do cell phone carriers have access to FaceTime call data (such as which caller initiated and ended a FaceTime call)? How does the radius of a pipe affect the rate of flow of fluid? Poiseuille's law states that the rate of flow of water is proportionate to $r^4$ where $r$ is the radius of the pipe. I don't see why.  Intuitively I would expect rate of flow of fluid to vary with $r^2$ as the volume of a cylinder varies with $r^2$ for a constant length. The volume that flows past a point is equal to rate of flow fluid, and thus it should vary with $r^2$.  I cannot understand the mathematical proof completely. Is there an intuitive explanation for this? Why do Unix man pages use double backticks in place of double quotes? I've noticed that man pages and other documents formatted by Unix utilities often use double backticks `` followed by double single quotes '' to wrap quoted phrases instead of the double quote character ". Single quotes are similarly replaced. Why is this?  Here are a couple examples, from the man page for grep:   To find all occurrences of the pattern `.Pp' at the beginning of a line:         $ grep '^\.Pp' myfile   The apostrophes ensure the entire expression is evaluated by grep instead  of by the user's shell.  The caret `^' matches the null string at the  beginning of a line, and the `\' escapes the `.', which would otherwise match  any character.   The grep utility is compliant with the IEEE Std 1003.1-2008 (``POSIX.1'')  specification. The Next tag badge block overlaps the badge score block. A simple pendulum suspended from the ceiling of a stationary lift has period $T_0$. When the lift descends at steady speed, the period is $T_1$. When the lift descends with constant downward acceleration, the period is $T_2$. Explain why $T_0 = T_1 &lt; T_2$.  I know that for small angles of oscillations, $T \approx 2\pi\sqrt\frac{l}{g}$ where $l$ is the length of the pendulum. For the first two cases, since $\sum F = 0$, the value of $g$ is apparently the same. However, I am unable to explain why the period is largest for $T_2$. If $g$ is the same for all cases, shouldn't their periods be the same? Single word which means "keep moving forward" I need a single word which means "keep moving forward". What are my options?  I need word as   persevere Be persistent, refuse to stop  cognizant (sometimes followed by 'of') having or showing knowledge or understanding or realization or perception  [] keep moving forward  I want to make meaningful name for firm  please help me What's the keyboard shortcut for keyboard layout switch in Mojave? Shift + Control + Space doesn't seem to work anymore. Can black holes form in a finite amount of time? One thing I know about black holes is that an object gets closer to the event horizon, gravitation time dilation make it move more slower from an outside perspective, so that it looks like it take an infinite amount of time for the object to reach the event horizon. It seems like a similar process should slow the formation of the black hole itself: As the star collapses, its gravitational time dilation make itself collapse more slowly. This make me wonder, are what astronomers claim to be black holes really black holes, or are they stars that progressively make themselves more similar to one without actually reaching the stage of having an event horizon?  EDIT: Contemplating one answer, I realize the question is ambiguous. What does finite time mean in general relativity. Here is a less ambiguous question: Is there a connected solution of 3+1 dimensional general relativity with one space-like slice not have a singularity, and another space-like slice having one. What "time travel" story required the traveller to mentally reconstruct his world in order to return to it? Here's what I remember about it:   The protagonist is sent a relatively short distance into the future (maybe a year? I've forgotten). When he arrives in this "future" he finds himself in a completely different world, with non-human inhabitants. The inhabitants use a machine to teach him their torturous language. He tries to return home, and (eventually) finds himself in a realm of chaos/nothingness. He laboriously reconstructs in his mind everything he can remember about his home and finds himself back there somehow. The twist is      that in his "home" reality everyone speaks the language he was taught by the non-human inhabitants at his first stop. Broken URL for data.stackexchange.com help page Possibility of recovering files from a dd zero-filled hard disk I have "zero filled" (complete wiped) an external hard disk using dd, and from what I have heard: people said you should at least "zero fill" 3 times to be sure that the data are really wiped and no one can recover anything.  So I decided to scan the disk once again after I've zero filled the disk. I was expecting the disk to still have some random binary left. It turned out that it has only a few sequential bytes in the very beginning. This is probably the file structure type and other headers stuff. Other than that, it's all zeros and nothing else.  So if we have to recover any file from a zero filled disk, ...how? From what I've heard, even you zero fill the disk, you should still have some data left. ...or could dd really completely annihilate all data? Charging lead-acid batteries? Error installing virtualbox-dkms on Ubuntu 20 Ubuntu 20.04. I installed virtualbox using package; it worked, I created and ran a RM. But then stopped to work after software update. I cannot run the VMs, message says : Kernel driver not installed (rc=-1908)  The VirtualBox Linux kernel driver is either not loaded or not set up correctly.  Please reinstall virtualbox-dkms package and load the kernel module by executing  'modprobe vboxdrv'  as root.  I managed to disable secure boot, so this is not related to this. Now I try to reinstall virtualbox-dkms package as requested : sudo apt remove virtualbox-dkms sudo apt install virtualbox-dkms  But then I get the following error : Préparation du dépaquetage de .../virtualbox-dkms_6.1.10-dfsg-1~ubuntu1.20.04.1_amd64.deb ... Dépaquetage de virtualbox-dkms (6.1.10-dfsg-1~ubuntu1.20.04.1) ... Paramétrage de virtualbox-dkms (6.1.10-dfsg-1~ubuntu1.20.04.1) ... Loading new virtualbox-6.1.10 DKMS files... Building for 5.8.0-34-generic Building initial module for 5.8.0-34-generic Error! Bad return status for module build on kernel: 5.8.0-34-generic (x86_64) Consult /var/lib/dkms/virtualbox/6.1.10/build/make.log for more information. dpkg: erreur de traitement du paquet virtualbox-dkms (--configure) :  installed virtualbox-dkms package post-installation script subprocess returned error exit status 10 Des erreurs ont été rencontrées pendant l'exécution :  virtualbox-dkms E: Sub-process /usr/bin/dpkg returned an error code (1)  If I look at /var/lib/dkms/virtualbox/6.1.10/build/make.log I see : /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:38: error: ‘cpu_tlbstate’ undeclared (first use in this function); did you mean ‘cpuhp_state’?   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                                      ^~~~~~~~~~~~ ./include/linux/percpu-defs.h:318:9: note: in definition of macro ‘__pcpu_size_call_return’   318 |  typeof(variable) pscr_ret__;     \       |         ^~~~~~~~ /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:24: note: in expansion of macro ‘this_cpu_read’   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                        ^~~~~~~~~~~~~ /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:38: note: each undeclared identifier is reported only once for each function it appears in   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                                      ^~~~~~~~~~~~ ./include/linux/percpu-defs.h:318:9: note: in definition of macro ‘__pcpu_size_call_return’   318 |  typeof(variable) pscr_ret__;     \       |         ^~~~~~~~ /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:24: note: in expansion of macro ‘this_cpu_read’   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                        ^~~~~~~~~~~~~ make[2]: *** [scripts/Makefile.build:290 : /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.o] Erreur 1 make[2]: *** Attente des tâches non terminées.... make[1]: *** [scripts/Makefile.build:519 : /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv] Erreur 2  What I am missing ? 1970s: Student creates complex program, forgets about it, and it becomes intelligent and finds him years later