According to :     Edits made by the same editor in a short period of time are collapsed: no matter how many times a post is edited within a 5-minute window, only one revision is stored ...   In this , revisions 2 and 3 (by me) for the question are less than 2 minutes apart, and yet they weren't rolled into one revision.  I posted an answer between the edits, but it's not the first time I've done that. Shouldn't the timer be post-specific?
When answers are posted within a question's initial grace period, it is possible that further edits could completely change the question (see ""), and render those first few answers incorrect.   Worse yet, nobody is notified that there was a change to the question, except those that are sitting on the page and notice the edit bar pop in. And of those, only those bothered enough to open it in a new window to compare the differences, will see how much was changed.   After the grace period is up, nobody will be able to consolidate why the first few answers actually answered a different question. And the answerers won't know unless someone comments or down-votes (and in the latter case, without context, they still might have trouble understanding, unless they memorized the question's initial state).  Jon Skeet stated it pretty well in  on :     I'd like this to apply to the question, as well as answers. Sometimes I (or others) have added perfectly good answers, but then the question has been changed within the grace period, making answers look foolish without any indication of what's happened.   So this time, my proposal is quite simple:     Once an answer is posted to a question within the initial grace period, a new grace period should start, and the current state of the question should be saved as the first revision. Further edits within the next 5 minutes will be aggregated into a new, second revision.   This will only noticeably affect questions where answers are posted within the grace period and the author of the question makes edits within 5 minutes of the first answer. (Effectively, it would treat it as if a different user made an edit within the author's grace period.) All other scenarios will continue to behave as they do today.  This feature request comes close:    However, the answer suggests a simple change to the wording or a pencil icon (like we see with edited comments), without adding a revision that can be viewed and compared. I don't think this is enough - in some cases it's going to be important to know what changed, not just when.
A friend sent a long a file (a .rar) he wanted me to check out for him before he installed it.  I downloaded it and unrared it with no problems, but it was full of .exe's instead of the intended contents (fonts) so I advised him to delete it immediately and not use.  I then proceeded to do the same, but the folder simply will not delete. Oddly the files went fine, and I never ran anything, but this is what I'm seeing:   Could not find this item  This is no longer located in C:\Users\This_User\Desktop. verify the item's location and try again.   I've tried the following things with no help:   Using "Unlocker" to Unlock and delete Using move on reboot and rebooting Using PendMoves (from sysinternals) and rebooting Elevating a cmd line, doing a dir /x to get the short name of the folder, and then del 'shortna~1' Moving the folder to a new folder and then trying to delete the parent folder   I'm on Windows 7 RTM, very fresh install. Any thoughts?  Update: Just to confirm, I've run Hijack this and half a dozen other malware detectors, and everything came back clean (no extra processes, no other obvious badness). Rebooting in safe mode didn't help either. How to download Bootcamp drivers without Bootcamp assistant? I'm setting up my MacBook Air for a Windows-only boot setup. This was easy enough. It already had rEFIt on it, I just connected a Windows 7 boot thumb drive, and away I went.  However, it seems Apple does not let you download Bootcamp drivers outside of their assistant tool. Reinstalling OS X just for the drivers is ridiculous.  This laptop no longer has OS X on it at all. How do I get the required drivers? I cannot find them anywhere on Apple's support pages.  Every other manufacturer has their drivers available for download.   How do I download the Windows drivers for my 2010 MacBook Air without the BootCamp Assistant? This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, navigate to the  tag.  This question and answer is owned by the community! If you can improve it and make it more useful, you're welcome to edit it.  I have a specific JSON structure in mind. I need to either deserialize this structure that's coming in from a web service, or I need to serialize data into this structure to transmit it to another system. How should I get started on this project in Apex? What is the difference between equation and formula? Sometimes equation and formula are used interchangeably, but I was wondering if there is a difference.  For example, suppose we can calculate a car's fuel efficiency as:  mpg = distance traveled in miles / the fuel used in a gallon   Is that an equation or formula? Shape gets distorted when adding stroke in Illustrator CS6 I very recently started learning how to use Adobe Illustrator (CS6), and just now I noticed something strange. When I add a 1pt stroke to my shape, it gets slightly distorted. This distortion does not disappear if I remove the stroke. (But only if I remove the stroke by setting its weight to 0. Using CTRL+Z does return the shape to its former state.)  After adding and removing the stroke a few times, the difference becomes quite noticable:   Am I doing something wrong? Is it a bug? I can't imagine this being the expected behaviour.  EDIT: I think I figured it out. Appearantly, turning 'Align to pixel grid' off doesn't affect previous shapes. If I turn it off and then recreate my shape from scratch, the problem is fixed.   However, I was wondering if their is a way to disable the effect for existing shapes. In other words, can I 'fix' the shapes I created while 'Align to pixel grid' was still on? Here's a module with castellated pads attached to an eval board:  (source: ) Looking closely at the wires interfacing with the castellated pads, they're clearly soldered to the eval board. However, they don't look like they're soldered to the module, but rather they're being pressed against the pads with the tension in the wire. It also looks like the free end of the loops are protruding down into a channel cut in the PCB. Do these kind of connectors/metal loops have a name? Why $9$ & $11$ are special in divisibility tests using decimal digit sums? (casting out nines & elevens) I don't know if this is a well-known fact, but I have observed that every number, no matter how large, that is equally divided by $9$, will equal $9$ if you add all the numbers it is made from until there is $1$ digit. A quick example of what I mean:  $9*99 = 891$ $8+9+1 = 18$ $1+8 = 9$  This works even with really long numbers like $4376331$ Why is that? This doesn't work with any other number. Similarly for $11$ and alternating digits sums. Ubuntu 17.10 windows' menu in panel I installed the latest version of Ubuntu (17.10) , but the problem is, I can't find the menu bars of applications in the GNOME panel. For instance, the Chrome menu bar doesn't appear on the panel like in Ubuntu 17.04 and earlier versions. I often see $I(t)\propto |E(t)|^2$. What is the exact form ? Which constants are missing to make this an equality and why are they so often omitted ? Is there a known well ordering of the reals? So, from what I understand, the axiom of choice is equivalent to the claim that every set can be . A set is well ordered by a relation, $R$ , if every subset has a least element. My question is: Has anyone constructed a well ordering on the reals?  First, I was going to ask this question about the rationals, but then I realised that if you pick your favourite bijection between rationals and the integers, this determines a well ordering on the rationals through the natural well order on $\mathbb{Z}$ . So it's not the denseness of the reals that makes it hard to well order them. So is it just the size of $\mathbb{R}$ that makes it difficult to find a well order for it? Why should that be?  To reiterate:   Is there a known well order on the Reals? If there is, does a similar construction work for larger cardinalities? Is there a largest cardinality for which the construction works? Can an observed event in fact be of zero probability? Can an observed event in fact be of zero probability?  Of course, I know that there exist non-empty events of zero probability. Mu question is the reverse: given that we have observed an event (and we have no other information about it, just the fact that it has been observed), is it possible that the event has in fact zero probability? Or does an observation necessarily mean that the probability is strictly positive?    Example context for the question:  Suppose $x_i$ (countably many) are i.i.d on $[0,1]$, but we do not know the distribution they come from. It may be uniform on $[0,1]$, may be discrete, may be any legitimate distribution (discrete or continuous). Just imagine we have some sort of a machine that shows us one by one a list of randomly drawn numbers between $0$ and $1$. We are comparing the observed numbers one by one to some special number chosen beforehand, for example $\frac12$. Now, given that at some iteration we have observed that special number at least once, does that mean that $\frac12$ has some positive probability under that (unknown) distribution? And if the probability can be zero, can we nevertheless say that we will necessarily observe $\frac12$ again later, if we continue the experiment ad infimum?  Also, disregard the "real world limitations" such as an inability to produce truly uniformly distibuted numbers, or rounding errors or any such thing. My Y axis is inverted! How do I fix that? When I play Black Ops 2, it seems that my xbox controller is inverted. Example: if I press up, my character looks down and vice versa. It was not like this before. Does anyone know how to reset the controller back to its original settings? One form of Jensen's inequality is     If $X$ is a random variable and $g$ is a convex function, then   $\mathbb{E}(g(X))\geq g(\mathbb{E}(X))$.   Just out of curiosity, when do we have equality? If and only if $g$ is constant? Dimension of Dirac $\gamma$ matrices While studying the Dirac equation, I came across this enigmatic passage on p. 551 in From Classical to Quantum Mechanics by G. Esposito, G. Marmo, G. Sudarshan regarding the $\gamma$ matrices:     $$\tag{16.1.2} (\gamma^0)^2 = I , (\gamma^j)^2 = -I \ (j=1,2,3) $$    $$\tag{16.1.3}  \gamma^0\gamma^j + \gamma^j \gamma^0 = 0 $$   $$\tag{16.1.4}  \gamma^j \gamma^k + \gamma^k \gamma^j = 0, \ j\neq k$$    In looking for solutions of these equations in terms of matrices, one finds that they must have as order a multiple of 4, and that there exists a solution of order 4.   Obviously the word order here means dimension. In my QM classes the lecturer referenced chapter 5 from Advanced Quantum Mechanics by F. Schwabl, especially as regards the dimension of Dirac $\gamma$ matrices. However there it is stated only that, since the number of positive and negative eigenvalues of $\alpha$ and $\beta^k$ must be equal, $n$ is even. Moreover, $n=2$ is not sufficient, so $n=4$ is the smallest possible dimension in which it is possible to realize the desired algebraic structure.  While I got that the smallest dimension is 4, I fail to find any argument to reject the possibility that $n=6$ could be a solution. I also checked  Phys.SE post, but I didn't find it helpful at all.  Can anyone help me? Google street view URL Hi I have the address of a property and my application can launch a browser to go to . If a good match is found it will take it directly there. Is there any thing I can append to the url to make it switch to streetview without having the exact coordinates? I dont't want to code any javascript or flash. Creating files in C++ Find and extract a number from a string What is a predicate in c#? Combine 4 cells in a table Here is a simple table.  I want to merge 4 cells. I want to combine the three "this" cells area in this table. I thought I have to use multirow and multicolum at same time. However, I could not find how to use it.  If possible, could you post the modified LaTeX source code?     My LaTeX code:  \documentclass{article} \usepackage{multirow}% http://ctan.org/pkg/multirow \usepackage{hhline}% http://ctan.org/pkg/hhline \begin{document}  \begin{table}[ph] \begin{center} \begin{tabular}{c|c|c|c|c} \hline \multirow{2}{*}{Raaa (k)} &amp; \multicolumn{4}{c}{C ()} \\ \hhline{~----}  &amp; 3.3 &amp; 2.5 &amp; 1 &amp; 0.5 \\ \hline \multirow{2}{*}{Raaa (k)} &amp; \multirow{2}{*}{this} &amp; this &amp; 0.5 &amp; 0.6\\ \hhline{~~~--}            &amp;                       &amp; this &amp; 0.7 &amp; 1.2 \\ \hline \end{tabular} \caption{R, C ripple size} \label{T:peak} \end{center} \end{table} \end{document} The indefinite article "an" is used when the following word starts with a vowel sound. For example one write "an adjective" but "a noun".   However, when an abbreviation is used, should this be based on the expanded meaning, or on the letters of the abbreviation.  Specifically, one writes "a noun phrase". However, here on ell.se, the abbreviation "NP" for 'noun phrase" is commonly used. If this were pronounced by sounding out its letters, as "En-Pee" it would call for "an". If it were read as "noun phrase"  it would call for "a". Should one write "a NP" or "an NP" here on ELL?  I incline to "a NP" and i used that in  just a few minutes ago, but I am not at all sure.