WiFi is unable to turn on and connect to network. I have tried many options available on the Internet and nothing is working to allow my MacBook Pro to connect to a WiFi network.   When in System Report under the WiFi tab it states Airport Utility: Not Installed (as shown in attached picture).  When I try to delete the network and reinstall it the WiFi option is not available in interface/service name (as shown in pic.)  I attempted to reset NVRAM &amp; SMC - this turned WiFi on for a few seconds allowed me to connect then it dropped again and I was not able to turn WiFi back on; so back to square one.   Any help fixing this would be greatly appreciated.  Running macOS Catalina - model A1278
I have a MacBook Pro 2009 running MacOS El Capitan. Recently the Wi-Fi has stopped working.   When I click on the Wi-Fi icon it displays the message "No hardware installed", but Ethernet still works.   Is there any way of fixing this by using a Wi-Fi dongle or something of the sort, if so do I need a specific dongle and how do I install it?
Media keys not working for iTunes (pause/play, skip buttons) In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public, protected and private, while making class and interface and dealing with inheritance? Equation of a line maintaining equal ratio distance between two points. Say I have two points. One at $A = (0, 0)$ and another at $B = (0, 10)$. I wish to derive an equation for a line that, for any point $P$ on the line, would equal a set ratio for the distance $P$ to $A$ and $P$ to $B$.  This is easy if the predetermined ratio for $A:B$ is $1:1$. I would create a line from $A$ to $B$, find its midpoint, then create an orthogonal line at the midpoint. Then at any $P$ on the line I know that the ratio distances from $P$ to $A$ and $B$ will be $1:1$.  But what if the ratio for $A:B$ is something like $11:18$?  This is for a positioning algorithm I am implementing - not for homework :)  EDIT: Note - If an exact formula is not possible, an approximation of the line out to $\pm 200$ from $A$ or $B$ is acceptable as values further from $A$ and $B$ will not be utilized anyway. A linear equation for the final result/approximation is ideal for speed in running multiple computations. Subsurf Modifier artifacts So I was messing with Subsurf modifier to create a certain sword and then some weird artifacts began to appear (cape-like). I've tried adjusting the Crease, but couldn't achive what I wanted. Basicly, what I whant is the as on the screens, but wo any artifacts :)   Also, here's the .blend file, cause I assume I didn't make myselt 100% clear. What can primes, except 2, 3, and 5, be congruent to $\pmod {30}$? After some trials, I found out that a prime $p \gt 5$ is congruent to $q\pmod{30}$, where $q$ is also a prime, and $1 \le q \lt 30 \;$ (i.e.  $p \equiv q\pmod{30}.$  Is there a way to write a formal proof to show this?  Is that an acceptable answer. Difference between Ethernet splitter and switch I have one Ethernet port that is wired directly to the router on another level.  However, I want to run a desktop and a server both off this one Ethernet port.  Can anyone tell me the difference between an Ethernet splitter and a switch?    Also, will either the splitter or switch slow down the connection as opposed to just one connection? Let's say a 10N cube (in air, on Earth) rests flat on a scale at the bottom of a tank of water, and the scale reads 8N, so there is 2N of buoyant force on the cube.  How does the buoyant force manifest itself on the cube?  I assume the force is normal to the surface of the scale, but if there isn't any water under the cube, how does the water push up on the cube? Favorite Tag Buttons partly sticking off page I appear to have found a bug, when adding Favorite tags, I find that the buttons are half off the page (this is of the  site):    Although on other sites it looks more like this:    I am running Ubuntu GNOME 15.04 with Firefox 41.0.1+build2-0ubuntu0.15.04.2. Missing files (basic sty files) when TEXINPUTS is set Below is my files tree:  .../Doc/Tex/book.tex .../Doc/Tex/images/im.jpg .../Doc/TexBase/myTemplate.sty .../Doc/TexBase/baseImages/logo.jpg   On Windows it was enough to set TEXINPUTS evironment variable with some paths and then I was able to compile with:  pdflatex Tex/book.tex   my document book.tex which uses package myTemplate.sty And now im trying to do teh same on Ubuntu 18.04. When i move all things to one folder (book.tex and myTemplate.sty and folder with images) then compilation is succesfull. But i would like to keep my foder structure as it is more clearly. So i tried to export TEXINPUTS:  export TEXTINPUTS=.:./TexBase/   but my compilation fail because of unfound many sty-files wchich are part of texlive-latex-extra that i already installed. When i UNSET this variable - it compiles ok. So my question is: Am i correctly set TEXINPUTS variable? Maybe i should add some other paths? What is the path to those "latex basic STY files"? Opening Ubuntu 20.04 Desktop on WSL2 I installed Ubuntu 20.04 (server/terminal) from the Windows 10 app store, and then after launching the Ubuntu Terminal via WSL2 (Windows Subsystems for Linux) , I installed Ubuntu Desktop and did several steps to try and get a desktop instance of Ubuntu 20.04 launched.  In short, the steps involved editing the .bashrc file, installing Xming, and then attempting to open the Ubuntu desktop in Xming with the &quot;startxfce4&quot; command.  However, &quot;startxfce4&quot; just doesn't open the desktop for me.  I can get programs to open with &quot;grun&quot; and the file explorer to open with &quot;gopen&quot; though, so it is working partially. Does anyone have any alternative suggestions to how I might get the terminal to open up the full Ubuntu Desktop?  Obviously, this wasn't what Windows had in mind with WSL2 so this is kind of a reach, but any input would be helpful.  Could I somehow do this from the file explorer or with a program that could opened from &quot;grun&quot; or &quot;gopen&quot;? Sometimes I create Material Groups to be used as appendable reusable assets. Unfortunately sometimes parameters I want to control using a Group Node's slider are not available for routing to a Group Node's input socket. Some examples of these are the Color Ramp and the Mapping Node.  So here's what I want to do:    Can this be done? If so, how?  Thanks! Creating point features with exact coordinates in QGIS? Can we have discussions? Guys, I just wonder if people are allowed to have civilized discussion (on any IT topic) on this forum without actually being accused of starting a row. I'm asking this question for a reason that few days I've asked few questions referring to VM, JIT etc. and compared them to C++ way and despite the fact that I've explained myself that I'm not starting any agro with anyone, that I'm really just genuinely curious, my post was first closed and then removed. I'm asking: What's wrong with asking nonstandard questions which sometimes my be quite difficult to answer? Thanks Bypass GPG signature checks only for a single repository Are film capacitors affected by DC bias? After looking around, I have found quite a few things about how DC bias reduces effective capacitance for a ceramic, or electrolytic capacitor, however nothing seems to talk about the effect on film capacitors. I've found a couple of papers about film caps (such as: ), and they mention frequency and temperature, but I can't find anything about DC bias reducing capacitance.  I have obviously checked the data sheet of the component I plan on using (), but there isn't anything about DC bias in that (unless I've just failed at spotting it).  This suggests to me that they aren't affected by DC bias, but that seems a bit of a bold claim, and I can't see that stated anywhere.  Are film capacitor values affected by DC bias? If so, can anyone point me to some data about what the roll off is?  I am planning to use some film capacitors in an application with 48-60V DC across the capacitors and a ripple current around 30 amps. Below is an example from I.N. Herstein:       Let  $R=\Bigg\{\left( \begin{array}{ccc} a &amp; b \\ -b &amp; a \end{array} \right)\Bigg|a,b\in \mathbb R\Bigg\}$ and let $\mathbb C$ be the field of complex numbers. Define $\psi :R\to \mathbb C$ by $\psi\left( \begin{array}{ccc} a &amp; b \\ -b &amp; a \end{array} \right)=a+bi.$       It is asked to prove that $\psi$ is a ring isomorphism of $R$ onto $\mathbb C$ .    can anyone help me with some hint how to prove the ring isomorphism. Why does $\lim_{n\to\infty}(1+\frac{1}{n})^n = e$ instead of $1$? On Wikipedia, it says that $\lim_{n\to\infty}(1+\frac{1}{n})^n = e$ :     It [e] is approximately equal to 2.71828,[1] and is the limit of (1 + 1/n)n as n approaches infinity, ... ()   When I evaluate $(1+\frac{1}{n})^n$ for $n = 10^8$, I get approximately $2.718281798347$ which indeed is pretty close to $e$.  But when I try to "solve" the limit using the laws of limits, I get  $$\lim_{n\to\infty}\left(1+\frac{1}{n}\right)^n = \left(\lim_{n\to\infty}\left(1+\frac{1}{n}\right)\right)^n$$  because of the power law  $$ = \left(\lim_{n\to\infty}(1)+\lim_{n\to\infty}\left(\frac{1}{n}\right)\right)^n$$  because of the addition law  $$=\left(1+0\right)^n = 1$$  but that would mean that $e=1$, which is obviously not true.  What am I missing / doing wrong?  Thanks in advance. Not for any specific program, just in general if I wanted to install something via APT how do I know what packages I need to "apt-get install" for that program Probability of Various Combinations of Weather There's a 10% chance it will rain today. There's a 15% chance it will snow today.   What percentage chance is it that it will:   Both rain and snow (it can both rain and snow at the same time)? Neither rain nor snow? -   Raining and snowing are independent of each other.  EDIT: (ADDED)   Rain or snow but not both? MSO Review Queue Privileges are Misleading When I visit Stack Overflow, I see the review option in the bar at the top of the screen.    However when on MSO, I don't see it. I assumed this was because I didn't have enough reputation to access the queue. I was curious what the requirement was on meta, so I moseyed on over to the privileges page. To my surprise, I saw that the privilege is listed as only requiring 500 rep and informs me I already have it:    Confused, I manually typed in meta.stackoverflow.com/review to see what would happen. The page did in fact load, but as you can see meta has no "First Posts" or "Late Answers" queue.    Seeing on that page that a minimum of 2k reputation is required to access any queues on MSO, I report the following bug:  1) On the privileges list on MSO, the 500 rep privilege of "Access first posts and late answers review queues" should not appear.  I also have the following feature request:  2) On the privileges list on MSO, it would be useful if instead there was a 2k privilege that informed you that you have access to the "Suggested Edits" and "Low Quality Posts" queues.