Close voting and comments that challenge consistency
How many questions on meta have asked, "Why can't I ask this question when that question is open"?
What lubricants can be safely added to a laptop fan? I've got a fan in a laptop that occasionally makes some loud airplane-like noises.  It mostly happens about 10 seconds after booting up and lasts for 10-20 seconds.  It also occasionally happens when the computer is running, but very rarely.  Interestingly, it does not seem to happen when the processor is being used heavily.  The laptop does not have a discrete graphics card.  The fan is clean.  I'm not sure if the laptop is under warranty, but I trust my own skills much more than I trust the manufacturer (or the shipper).  Before I search for a matching fan and replace it, I thought I would see if it is safe to try any lubricants.  Are there any lubricants that are safe to use inside a laptop?  I don't want a fire or anything that will splatter and cause conductivity issues within the circuitry. What makes a chewy brownie? I've tried many different brownie recipes and most of mine bake to a cake-like consistency. The brownie holy grail for me is crusty top chewy brownies. What can I add/remove/do that will make my brownies chewier? Let's assume you have a table groups and a table item. Each item belongs to exactly one group. It is an inherent part of that group. An item cannot exist outside of a group and it cannot be moved to another group.  When trying to decide on a primary key for the item table, what should I use?  Should I make up an artificial global serial key like this:  CREATE TABLE items (     item serial PRIMARY KEY,     group integer NOT NULL REFERENCES groups(group), );   ... or should I rather use a composite key and per-group item serial like this:  CREATE TABLE items (     group integer NOT NULL REFERENCES groups(group),     item integer NOT NULL,      PRIMARY KEY(group, item) );   The reason why I'm leaning more towards the second solution is that the post URL will always show the group and item, so it makes sense to have both of them as the composite primary key. In case of the first solution, the URL contains superfluous information because the group ID can already be deduced from the item ID alone. The URL structure is given, however, and cannot be changed.  The disadvantage of the second solution is that you have to manage a per-group serial (i.e. each item integer should start from 0 for each group).  What's better in terms of best practices, normalization and performance? Or is it simply a matter of taste? How to implement "select all" check box in HTML? Can someone please give me a tip how to show that for distinct prime $p,q$ that $\mathbb{Q}(\sqrt{p},\sqrt[3]{q})=\mathbb{Q}(\sqrt{p}\sqrt[3]{q})$ and how to find the minimal polynomial of $\sqrt{p}\sqrt[3]{q}$ over $\mathbb{Q}$ ? Which is correct: "one or more is" or "one or more are"? Should the phrase be "one or more is...", or "one or more are..."? Is the ArcGIS Server JavaScript API free to use? The 2008  announcing the ArcGIS Server JS API says:     Everyone can use the ArcGIS JavaScript API. There is no fee for using the ArcGIS JavaScript API or deploying an application built with it.   But Esri's  page says "Contact us for pricing".  Which is correct? Writing function definition in header files in C++ I have a class which has many small functions. By small functions, I mean functions that doesn't do any processing but just return a literal value. Something like:  string Foo::method() const{     return "A"; }   I have created a header file "Foo.h" and source file "Foo.cpp". But since the function is very small, I am thinking about putting it in the header file itself. I have the following questions:   Is there any performance or other issues if I put these function definition in header file? I will have many functions like this. My understanding is when the compilation is done, compiler will expand the header file and place it where it is included. Is that correct? A 256GB SSD has Windows-10 and 16.04 installed.  BIOS not UEFI.  A charity I work with requires me to use Quickbooks Desktop on Windows.  The plan is to ghost the existing system to a 512GB or larger SSD and create a third bootable Windows 7  partition for performing charity activities.   Is this possible to have a third partition? Is there a good example you have used as a guide? Is triple booting with two Windows partitions different from 2 Linux partitions?   If you have done this before ( with GRUB) please indicate this in your response: lessons-learned are appreciated.  Thank you Prove that 1/2 + 1/4 + 1/8 ....... = 1 I've often heard that instead of adding up to a little less than one, 1/2 + 1/4 + 1/8... = 1. Is there any way to prove this using equations without using Sigma, or is it just an accepted fact? I need it without Sigma so I can explain it to my little sister.  It is not a duplicate because this one does not use Sigma, and the one marked as duplicate does. I want it to use variables and equations. Non-empty intersection. Let $A_1,A_2,...,A_{2019}$ be sets s.t. $|A_i|$=45 for each $i=\overline{1,2019}$ and $|A_i\cap A_j|=1$ for every $i\neq j$. Is it true that $$\Big|\bigcap _{i=1}^{2019} A_i\Big|=1?$$ What I thought of doing is proving by induction by i, the base is obvious. However I'm stuck on the next step. How can I pass arguments to a batch file? How can I kill a thread? without using stop(); X, along with Y, "were" or "was"? I was interested in the following sentence which appeared in a   in The Washington Post, Politics, (WHO RUNS GOV).     She, along with Mark Childress, were set to be Daschle's deputies at   the White House before he stepped down.   Can someone clarify if the fragment "She, along with Mark Childress, were set to" is ungrammatical, as I think it is?  I would reword were with was because I think that the subject of the sentence - obviously, in grammatical terms - is "She", not "She" and "Mark Childress", but I'm not sure on this correction.  More precisely, I'm not so sure that "She, along with Mark Childress" is equivalent to She and Mark Childress with regard to the effects on the grammatical numbers. In which ways did scanning Nero's ship enhance/change Starfleet technology? I've heard the explanation that the Enterprise from 2009's Star Trek looked so much more advanced was because data gathered from the Kelvin initially scanning Nero's ship when it first appeared enabled them to upgrade their tech. I'm wondering if they've ever detailed exactly what technologies were advanced or enhanced or discovered. Evaluate the line segment intergal Evaluate the line integral  $$\int_C xe^{y}\, {\rm d}s,$$  where $C$ is the line segment from $(-1,2)$ to $(1,1)$.  I do not get this part of calculus at all please show me how this is solved and if you give me hints is ok too. Please help me. Thanks In chapter 2, the section on bitwise operators (section 2.9), I'm having trouble understanding how one of the sample methods works.  Here's the method provided:  unsigned int getbits(unsigned int x, int p, int n) {     return (x &gt;&gt; (p + 1 - n)) &amp; ~(~0 &lt;&lt; n); }   The idea is that, for the given number x, it will return the n bits starting at position p, counting from the right (with the farthest right bit being position 0). Given the following main() method:  int main(void) {     int x = 0xF994, p = 4, n = 3;     int z = getbits(x, p, n);     printf("getbits(%u (%x), %d, %d) = %u (%X)\n", x, x, p, n, z, z);      return 0; }   The output is:     getbits(63892 (f994), 4, 3) = 5 (5)   I get portions of this, but am having trouble with the "big picture," mostly because of the bits (no pun intended) that I don't understand.  The part I'm specifically having issues with is the complements piece: ~(~0 &lt;&lt; n). I think I get the first part, dealing with x; it's this part (and then the mask) that I'm struggling with -- and how it all comes together to actually retrieve those bits. (Which I've verified it is doing, both with code and checking my results using calc.exe -- thank God it has a binary view!)  Any help? Scheduling a Round Robin tournament - 4-way games I'm looking to schedule 16 players to play a round robin tournament with each other such that there are 4 players at each table.  I'd like for each player to play with each other player exactly once over the course of 5 rounds.  I just took a look at this post:  , and I was wondering if anyone knows if the case n=m=4 has been solved, and if so what that solution is. After my lie down, I posted  on SO. As I suspected would happen, it got moved to programmers. Unfortunately, the kind of people I'm interested in getting answers from (litb,skeet et al - the top SO programmers in their respective disciplines) don't frequent Programmers much. So my question is, where to ask somewhat non-specific questions of high-powered users? How should I unit test multithreaded code?