Why don't we have a place for opinion based programming questions
Where to ask "subjective and argumentative" questions on programming?
Let $\displaystyle f$ be differentiable, $\displaystyle f(x)=0$ for $|x| \geq 10 $ and $g(x)=\sum_{k \in \mathbb Z}f(x+k).$ Cleaning PCBs... using water? I found  where a technician with a lot of experience seems to clean his PCBs using water, and then he just puts it in the sun so it can dry. I was just amazed to see the circuit keeps working as intended, he says he keeps doing this all the time and several times, however I doubt this is normal.  Which leave me some questions:   What are the recommended methods to clean huge PCBs like the one in the video? What happens to charged capacitors when water shorts them out? Solder joints do not get any kind of corrosion? Is the antisolder mask waterproof? Solve the equation $x^3 + 117y^3 = 5$ over the integers. Equivalent of typedef in C# Is there a typedef equivalent in C#, or someway to get some sort of similar behaviour? I've done some googling, but everywhere I look seems to be negative. Currently I have a situation similar to the following:  class GenericClass&lt;T&gt;  {     public event EventHandler&lt;EventData&gt; MyEvent;     public class EventData : EventArgs { /* snip */ }     // ... snip }   Now, it doesn't take a rocket scientist to figure out that this can very quickly lead to a lot of typing (apologies for the horrible pun) when trying to implement a handler for that event. It'd end up being something like this:  GenericClass&lt;int&gt; gcInt = new GenericClass&lt;int&gt;; gcInt.MyEvent += new EventHandler&lt;GenericClass&lt;int&gt;.EventData&gt;(gcInt_MyEvent); // ...  private void gcInt_MyEvent(object sender, GenericClass&lt;int&gt;.EventData e) {     throw new NotImplementedException(); }   Except, in my case, I was already using a complex type, not just an int. It'd be nice if it were possible to simplify this a little...  Edit: ie. perhaps typedefing the EventHandler instead of needing to redefine it to get similar behaviour. List View Visibility Get three highest values from the array How do you prevent web pages from appearing in the Google search index? How can one derive Schrödinger equation? The  is the basis to understanding quantum mechanics, but how can one derive it? I asked my instructor but he told me that it came from the experience of Schrödinger and his experiments. My question is, can one derive the Schrödinger equation mathematically? Why is my StackOverflow with an indent and doesn't have reputation Stack Exchange iOS app nearing beta We're getting very close to releasing our iOS app on the App Store.  Since the , we have taken on hundreds of users, fixed a lot of bugs, and we have approached feature completion for v1.0.  We're still working on finishing touches and fixing crashes - but there aren't too many of those these days.  We believe we'll have this out in .    Current Alpha Testers:  We want to extend to you a huge thank you for using our app and giving us feedback.  We've made a ton of improvements that filtered through  here on meta.  We're pretty greedy, though, and we want more of your feedback as we get close to beta.  If you've been using the app, please leave an answer to tell us how you think we've done so far.  Don't go easy on us - we want to get this as right as we can before hitting the App Store.  You might even consider telling us how many stars you would give us if we were in the store.  Also, we created a room called  for more casual discussion about the app.  Everyone Else:  The alpha will continue in the interim, and we still .  The invitations are sent out once a week (usually), so if you don't get an invite right away, don't panic.  We'll get to you.  Bugs or feature requests should be reported here on meta and tagged .  Update, 5/1/2014    As of today, the app is submitted for review.  A great big thanks to all our alpha testers!  Your feedback has been invaluable and has truly helped us make the app much better than it would have been without you.  So what now?  Well, we intend to keep the alpha test group around, except now we're considering it the "beta channel".  It's still important to us, particularly since the update cycle through the AppStore is slow.  We'll still roll out updates in the same way that we have been.  We will also from time ask for targeted feedback on specific features.  And, lastly, if you're just now getting here and wished you had signed up for the alpha, feel free to sign up now anyway.  The form is still there, and we may still let in additional users to the beta channel depending on what our "active users" count looks like. This is a  about  the use of a *AMPP's stack.    I recently had a talk with some experienced people and they suggested to me not to use a WAMP stack, and instead install apache, mysql and php separately.  I don't understand why they have suggested this, though, so can anyone tell me?  Is there a particular disadvantage of WAMP, or a particular advantage to installing all of them separately?  Since a WAMP stack itself is composed of apache, mysql and php, then what's the difference between using the WAMP stack and installing them all separately? Whenever I play a PC game with the directional keys, I can only press two buttons at a time.  For instance if I am playing a shooter like R-Type, I cannot hold down the fire button while moving diagonally at the same time.  The computer simply ignores the extra button press.  How do I remove this limit so I can shoot while moving diagonally?  This limitation seems to apply for every game.  I am running Windows 7 if it makes any difference.  I noticed the same problem back when I used Windows XP. I know that the emergency services can be called FREE in the UK by dialing 999 and in the US by dialing 911.   What I don't know is the number to call in other countries and if there is a cost involved. This is something I think most people should find out before travelling but many don't (including me). Hopefully this will help me and other people. E: Malformed entry 54 in list file /etc/apt/sources.list (Component) Seeking SF Short Story from late 1970s/early 1980s about dystopian future with an old man playing a piano I read this in the late 1970s or early 1980s, possibly as part of a juvenile fiction anthology/collection. From what I remember in this story a post-apocalyptic society requires each member to go out before their 18th birthday and kill an "oldster" adult (i.e. I think over 30 similar to the time in Logan's Run) to make room for themselves.  Otherwise they will be killed.   The kids actually cut off the hand of the victim which has a tattoo on it with the birthdate/age. In this case, the world has gotten to the point the person who kills the oldest person gets a "prize" of one more year of life beyond 30. Note, this is NOT Logan's run nor the novel upon which it is based.   The hero in this case finds an old man, the oldest he had ever seen (something like 45-50 I think) making wonderful sounds with a strange device. It was a piano.   He then confronts the old man  SPOILER ALERT     ... but cannot bear to kill him. The old man takes pity on the boy and offers him his hand to take back so he can live. The boy asks if the old man will still be able to play the piano with just one hand. The old man smiles and says "Yes, but not as well. " Then, the boy decides to stay with the old man and risk becoming an outlaw so he can learn to play the piano. What is the command to open the shutdown dialog? How many possible electromagnetic wavelengths are possible? Disclaimer: Please keep in mind that I am a young highschool student with no background in physics, this research was done in the course of an hour, and my reasoning could very well be wrong.  After a short conversation about color, I did some thinking, and read  The answer claims that there are $\infty^{\infty}$ colors   My first problem is the definition of colors, I'm going to simplify this (although it's not the same thing) as electromagnetic frequencies. This is what I mean when I refer to color in the rest of this question  The problem with $\infty^{\infty}$ colors is that the plank length exists. This causes two problems to arise with $\infty^{\infty}$. If $l_p$ is assumed to exist (as it is), this means the smallest distance in the universe is $l_p$. So, all wavelengths of light can be divided into a set, of the wavelengths produced by objects at $0^{\circ}$ Kelvin to $\infty^{\circ}$ Kelvin. According to this logic, there are simply $\infty$ colors.  Things are complicated further, when you introduce the Plank Temperature ($P_t$). $P_t$ is the theoretical limit temperature of the universe (at least for the purposes of light and color) Because an object hotter than $P_t$ will produce light with wavelengths shorter than $l_p$. This would introduce an upper limit on colors too.  Wouldn't this mean that the total number of possible colors is equal to however many plank lengths difference there is between an electromagnetic wave produced by a 0 degree object and a $l_p$ object? And therefor far less than $\infty$? Does this reasoning make sense at all? How can I find out which app is putting ads in my notification bar? Possible Duplicate:          Recently advertisements have started appearing as notifications in my phone's notification bar. The icon on the ad are either a green plus sign or a white star with a red circle inside it. There is no indication in the notification as to which app it came from.  I haven't installed any new applications, so I assume that some application updated to include this intrusive new ad system. Ads only show up at irregular intervals once every few hours, so removing all my apps one by one until the ads stop is not really a viable option, since I would have to wait several hours in between each uninstall to see if another ad appears. (I'm sure this is by design.)  So is there any way to figure out the source application of these notification ads?  My phone is a rooted/unlocked/whatever HTC Droid Incredible running MIUI. How do I backup ssh keys? I am planning to do a fresh install of ubuntu 11.10 in my system. Before that i have setuped key based ssh authentication in this machine. Is it possible to take backup of those ssh keys, so that i  can use that in my new installation. Or else i must setup keybased ssh authentication again? If i can take backup, what are the files i need to copy? Can someone explain it in detail pls. Thanks in advance. How to make /sbin/shutdown, /sbin/reboot etc. require sudo again in 16.04? For whatever reason, we do no longer need to be root (or using sudo) to run /sbin/shutdown, /sbin/reboot etc.  This seems to be because those executables are now symlinks to /bin/systemctl which handles everything as normal user.  However, what if I want shutdown and reboot to require root authentication again? How can I achieve this?