Simplifying a ratio of powers

Question: This might sound like a stupid question but when it comes to simplifying when using the ratio test I get confused. Can someone please explain why $$\frac{2^{n+1}}{2^n}=\frac{2}{1}?$$ I think I might be thinking too hard because this confuses me.
Answer: It's the rule for dividing exponents. $\frac{x^a}{x^b}=x^{a-b}$.
You can also think of it this way:
$$\frac{2^{n+1}}{2^n}=\frac{2\cdot \cdots \cdot 2 \cdot 2}{2\cdot \cdots \cdot 2}$$
where the number $2$ occurs $n+1$ times in the numerator and $n$ times in the denominator. Exactly $n$ of those cancel, leaving a single $2$ on top, and nothing but $1$ on the bottom.
Answer: Here, we have
\begin{align}
\frac{2^{n+1}}{2^n}&=2^{(n+1)-n} & \text{using exponent law $x^{a-b}=\frac{x^a}{x^b}$}\\
&=2^1 & \\
&=\frac{2}{1} & \text{because } 2^1=2=\frac{2}{1}
\end{align}
Answer: Think about it this way. When you write $2^{n+1}$ you are multiplying a bunch of $2$s in sequence. Same for $2^n$. So if we write that as a bunch of $2$s:
(for $n=5$)
$\frac{2 * 2 * 2 * 2 * 2 * 2}{2 * 2 * 2 * 2 * 2}$
We can cancel out all of the 2s on the bottom and leave a single $2$ on top. And that single $2$ is the same as $2/1$.

Simplifying a ratio of powers


Python "app transport security" error under El Capitan

Question: Some of my Python shell scripts are newly throwing security errors under Apple OSX 10.11, El Capitan. It seems the new App Transport Security doesn't like how the scripts are calling HTTP resources in plain text, rather than using HTTPS.
Fetching http://blahblah.com
Python[5553:5648168] App Transport Security has blocked a cleartext HTTP (http://)
resource load since it is insecure. Temporary exceptions can be configured
via your app's Info.plist file.

How might I go about fixing this? There is no HTTPS resource I can call, so I'm stuck with HTTP. The advice from Apple is to make an exception in the app's info.plist file, but this is a Python script invoked from a shell script, so there is no info.plist file to be edited.
Ideas? The root problem seems to be with webkit2png, which is in Python. Its non-HTTPS requests are being blocked by ATS, and there is no info.plist to modify.
Answer: I found a solution here that worked for me: https://apple.stackexchange.com/questions/210588/how-does-one-configure-a-temporary-exception-to-ats-on-el-capitan-and-fix-webkit
First make sure you have a version of webkit2png that is new enough to have the --ignore-ssl-check option. Version 0.5 does NOT have this option.
Second, you need to edit the source file and add a couple lines of code as shown here: https://github.com/bendalton/webkit2png/commit/9a96ac8977c386a84edb674ca1518e90452cee88
Finally use option as indicated in the solution linked above (copied here for convenience):
webkit2png --ignore-ssl-check [options] [http://example/]

Answer: Thanks for Arthur Hebert
At first I'm confused for the code then I figure it out
so I summarise the steps as follows for reference

import AppKit
Add the following code in your py script
AppKit.NSBundle.mainBundle().infoDictionary()['NSAppTransportSecurity'] = dict(NSAllowsArbitraryLoads = True)

Assume you are sure to use no HTTPS resource in MAC OSX higher than 10.11
The installation of webkit2png is not necessary in my case


Disable User Account Remotely

Question: I work for a highly distributed IT based consulting firm with approximately 150 users in the field at different client sites at any given time.  As we have grown we have needed to ability to disable a user access to a company laptop remotely.  Is there something out there that will prevent that user from logging into his laptop once his account has been disabled in Active Directory.  As it has been explained to me the answer is basically "Not until communication with the AD has been established." either via VPN or them coming to one of our main branches.  Is this correct?  Are there any third party applications that can facilitate this?  I personally can't work out a situation where it's possible to do this without the minimum requirement of an active network connection.
Comment: FYI I will most certainly willing to be told this is impossible as I personally believe that it is.  But management wants to option and I feel it necessary to check all options.
Answer: We have ran into this same problem with our remote, work at home staff when someone quits or is let go.
Our solution is to basically assume that since they have physical access to the laptop, there is no point in trying to disable their account remotely (a simple boot CD can give access to the hard drive again).  Instead, we just remove all remote access to our network (VPN, AD accounts) so they can no longer access protected resources.
Answer: We have had similar situations within our company.
You have basically two options:

wait for the local cache to expire,
then the login will stop working.
Takes a few days. There might even
be a setting somewhere in the
registry, but we have so far not
bothered looking for it. Once that
has happened, and there are no local
user accounts (of which the user
knows the password), the
laptop/desktop effectively becomes
useless to that person.
configure your VPN to start up as a service.
   In that case the VPN connection is
    established before the login screen
    comes up and the disabled account
    immediately results in a login
    failure. Once that has happened, the
    local cache is also in that status
    and you can then disable the VPN
    credentials.

Obviously, the second option does require a bit of preparation and your question sounds like you don't have that option.
Comment: Even forcing a VPN connection does not help as the person can disconnect their laptop from the network completely.
Comment: I'm not sure what the timeframe on the local password cache expiring is, but it's definitely longer than a few days.
Answer: You turn off password caching in windows completely, however this would require that they be able to access the network prior to logging in.
Turning off password caching..
Answer: Install everything on an encrypted partition that must access a key over the network in an authenticated fashion which makes the partition readable.  This of course would be complicated to do after the fact.
You can then revoke the authentication to this ey whenever, or just block that request.
Answer: I'm guessing that the remote person needs to be denied access to company and/or client files as quickly as possible, which suggests something in the trust system has broken down. As these are IT consultants I would expect them to be aware of at least some of the many ways that they can get full access to the computer. If they cannot be trusted with the information on the computers I would suggest they also cannot be trusted to be good little boys and girls and not simply crack the system, which makes the entire exercise just a little pointless.
The Golden Rule of computer access: The person who has physical access to a computer potentially has access to what's on said computer. Encrypted drives are your only hope in such a circumstance.
Comment: And even encrypted drives can be beat, especially if the system had been successfully logged into.
Answer: The short answer is, "No." The reason is that without communication with some sort of interface on your side to tell the computer that there has been a change to the user's status, the computer doesn't know to perform the action. Even with that said, as John Gardeniers pointed out, if they have physical access, they can still potentially access the computer's contents. One of the rules of security from Microsoft's list is appropiate... (paraphrased) "If I have physical access to your computer, it's not your computer anymore."
One common technique, if the user has administrative rights, is simply to create a local user account. If they don't have admin rights, there are still some techniques to privilege escalate to an administrative level user and then the subsequent user account creation. Then all the other techniques of stopping access are bypassed. This illustrates that security principle.

Disable User Account Remotely


Do magnesium and tin have the same volume?

Question: Having the same atomic radii of 145 pm, should one mole of tin and one mole of magnesium take up the same volume? Since tin is much heavier, that means tin is much denser than magnesium. Is this true, or is there an error in my thought process.
Comment: I do not think this is a homework question. In fact it offers an opportunity to clarify some interesting issues.
Comment: You have to specify conditions, and if we are speaking of crystalline matter, what polymorphs you are interested in. It's very unlikely that both are going to have the exact same [molar volume](https://periodictable.com/Properties/A/MolarVolume.an.html).
Comment: I think this is a superb question! The measure of atomic sizes is done by many methods, all of which have value. So when you see a number like atomic radius = 145 pm, is that definitive? No, because the packing of atoms is not always the same, as noted below. But the contrast between densities and molar volumes is instructive. Tin is denser ("heavier") (7.31 g/cc) than Mg (1.731), but the molar volumes are fairly close (Sn: 16.29 cc) vs Mg (14.00 cc). So the numbers of atoms in a given volume are similar, but tin weighs 118.7, while Mg weighs a paltry 24.3.
Answer: No, that is not how it works.
Atomic radius means the radius of an atom. A single atom. It does not in and by itself mean that a solid chunk of a material has a particular density. A solid chunk of material has many atoms, and they are arranged in certain ways and sometimes more than one way of this arrangement is possible.
Tin and Magnesium are very different. Magnesium is arranged in a hexagonal close packed structure, basically just repeating units of skewed (rombohedric) prisms. This can be hard to imagine, but imagine just stacking perfect spheres so they rest on each other and likely you will end up at a close packing arrangement. (there are only two*, try to find them. Hint: one has three layers before it repeats the bottom, the other has only two layers then it repeats)
*: There are actually 4, but you'll need a lot of layers and a lot of spheres to find those.
Tin has two different ones, so already here your question has to be no'ed without further investigation, but lets anyway. The first one, grey tin (${\alpha}$) has a diamond like structure. I am finding it hard to describe them in a meaningful way, but they have examples over at the excellent Wikipedia. The other one, tin (${\beta}$) which is white has a body centered tetragonal - which is basically stack 4 - put 1 in the middle and then stack 4 on top of that again (yes, the spheres will roll off, but there are so many of them per layer that hardly any of them do.) The white one is amusing, if you bend it it screams like you are hurting it. Sounds absolutely disgusting, like nails on a chalkboard. This is related to it's structure.
Summary:
When you put a whole mole (ha... ha...) of atoms together, they organize in structures, and it is the number of atoms per volume that you have to multiply with the atomic weight to get the density of the chunk. Fortunately for most kinds of structures, you don't have to do this, someone already has done the work, by actually measuring the densities of crystals and made tables. Just look it up.
Comment: One should note that there are more than 2 close packed structures (see https://en.wikipedia.org/wiki/Periodic_table_(crystal_structure)). The main one, DHCP, found in several Lanthanides/Actinides, is ABACABAC. Samarium is particularly weird. In theory, any periodic arrangement of (A,B,C) would be close packing. In reality, the longer the period the less likely it will be found in nature.
Comment: @JonCuster Right you are. I was drawing from memory, didn't remember those weird ones. I am still leaning towards keeping it simple for the OP though. Should I edit what you suggest in or... ?
Comment: Up to you. A parenthetical comment added would be more than enough.


Upper bound on the number of vertex transitive graphs

Question: Is there a known upper bound on the number of vertex transitive graphs on $n$ vertices?
Comment: There are $2^{n-1}$ ways to choose the neighbours of the first vertex.  Then the group action gives all the other edges.
Comment: $2^{n-1}$ times the number of minimal transitive groups would be a fair bound, but I don't know a bound on the number of minimal transitive groups.  For this reason, adding a group category to your question might be a good idea.
Comment: What is the reason for the $2^{n-1}$ factor?
Answer: I think only very rough bounds are known.
In http://arxiv.org/abs/1210.5736, it is conjectured that the answer for fixed valency d is roughly of the form $n^{d\log n}$.
This is proved for Cayley graphs and for $d=3$.
As Brendan mentions, obtaining upper bounds on the number of minimal transitive groups of a given degree would yield upper bounds. The best results in this direction are due to Pyber, I believe, but are not tight. I think this may be in :
Pyber, László
Asymptotic results for permutation groups. (English summary) Groups and computation (New Brunswick, NJ, 1991), 197–219,
DIMACS Ser. Discrete Math. Theoret. Comput. Sci., 11, Amer. Math. Soc., Providence, RI, 1993.


Data view web part joined subview fails due to extra characters in ID field

Question: I created a joined subview in a data view web part however it is failing to find any matching items because one of my join columns IdeaID. is bringing in additional characters (see image below).  Unfortunately I can't add another column to my list that contains only the IdeaID value because it will interfere with an SSIS ETL I have in place.  I suspect I need to add some XSLT like xsl:value-of select="format-number(substring-before(@IdeaID.,';#'),',##0;-,##0')"/>to trim the IdeaID but I can't seem to hit on the correct line of code in SharePoint Designer.  Anyone know what XSLT needs to be modifed so that my IdeaID will render correctly and successfully find a match?  Thanks in advance!
Answer: Unless I misunderstand, you should be able to create a variable at the template level and pass that down as a parameter to your join filter. Here's a rough example:
<xsl:template name="dvt_1.rowview">
 <xsl:variable name="ItemID" select="substring-after(@IdeaID., ';#')" />

Personally, I much prefer using the "Related Items" subview than the joined subview, but there are definitely times when joined is better.
If you're calling the page from a link you have control over, you could also set up a query string parameter in the DVWP and pass the ID that way via your link.


How to create an .etl file with a Data Collector Set

Question: Was wondering how do you go about logging a Data Collector Set(Specifically a Trace Session) using PerfMon on Windows 11. I understand there's a shortcut to create a dump on a crash, but how do i generate a etl file on call.
Answer: I Figured out how to do this; So thought i'd leave the steps I used for anyone searching in the future.
1. Open PerfMon
2. Select the 'Data Collector Sets' folder option in the left hand pane
->Following, Select the 'User Defined' Folder
3.In the Action Pane above there will be an icon, furthest on the right resembling a window with a golden asterisk.-> Click it to activate the wizard
4.Follow the Wizard instructions


Following the new WhatsApp data privacy update, why does WhatsApp ask from users, even if they didn't, who is going to check their source code?

Question: New WhatsApp data privacy update, that it will share our data with Facebook, we all know Facebook owns WhatsApp and this is obvious Facebook can always access users of WhatsApp as well. So why to ask from us even if they can do it and we won't even complaint against it?
And what if Facebook access WhatsApp users data, who is responsible to check source code of these apps?
Comment: "Why don't they just access data?" Privacy regulations. "But we won't complain!" Irrelevant to regulations. And I'm not sure how source code review factors into anything. Can you explain or rephrase that part of the question?
Answer: As Schroeder stated, it is not a matter of them just "accessing the data". Sure, Facebook owns WhatsApp but that doesn't mean they can outright skirt the law. Even though there is nothing technically stopping them. The law & the impending huge fine is a deterrent of this behaviour, as it is designed to be.
If Facebook were to access WhatsApp data without informing users in their privacy policy that this takes place, that is a huge infringement of privacy regulations.


Limit memory used for mongoDb

Question: Is there any way to limit using RAM for mongodb on Debian? I'm looking for a solution fo about 8 hours, but have no results.
Comment: You could use ulimit but it could effect performance if your working set exceeds the amount you allocate
Answer: I have heard that some folks have had success using lxc to isolate MongoDB on Linux. There are other container technologies out there, but that seems to be the most mainstream option.
Answer: It is possible using cgroups.
Some tutorials are available as well as shell script for Ubuntu 14.04.
See also Is there any option to limit mongodb memory usage? on Stack Overflow.

Limit memory used for mongoDb


Will Realm still be able to save the data while user has locked iPhone?

Question: I am trying to save some data to Ream database while users have locked their iPhone. Thie data may be the location coordinate which produced by background location updates. If realm can't do it. Could Core Data do it?
This is how I do it in code:
<code>- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray<CLLocation *> *)locations {
    NSLog(@"didUpdateLocations: %@", locations);

    if (locations.count > 0) {
        CLLocation *location = locations.firstObject;

        if (location.horizontalAccuracy < 0) {
            return;
        }

        JBLocation *locationObject = [[JBLocation alloc] init];
        locationObject.lat = location.coordinate.latitude;
        locationObject.lon = location.coordinate.longitude;
        locationObject.date = [NSDate new];
        locationObject.speed = location.speed;

        RLMRealm *realm = [RLMRealm defaultRealm];
        [realm beginWriteTransaction];
        [realm addObject:locationObject];
        [realm commitWriteTransaction];
    }
}
</code>
Answer: Doing something while the phone is locked is an example of a background task. Though I'm not sure if you will be successful in doing a task in the background even for once, but it is certain that when the OS kills your app, it can't do what you want to do any longer.
I'm doing in a project that is similar to yours (background location fetching, saving to local database the data, posting to the server while the screen is locked.) It is already complete but waiting for release signal. It was also submitted (approved) to the Apple as Beta.
I used this sample project as a library and ported to Swift:
https://github.com/voyage11/Location


How to create text file from collections and save it in SD in Android mobiles using meteorjs

Question: How to create text file by reading data from collections and save it to Internal memory in Android mobiles using meteorjs.
When I click generate button, a text file should create and save to sd card or internal memory with my specific folder. This is an offline android app, so there is no server connection and file creation should be done in client side only.
Please help me
Answer: There is a Cordova plugin:
cordova-plugin-file
This plugin implements a File API allowing read/write access to files residing on the device.


Is it possible to post pictures in comments?

Question: I was wondering if it is possible to post pictures in comments? It might be useful for clarification of difficult questions. If not then could it be a feature?
Comment: Why the down votes? It's a meta question!
Answer: I'd argue a picture, posted in a comment, should really be made as a clarifying edit to the answer or to the question -- wherever the comment was going to be made.
Answer: It's not possible currently, but we can leave it here tagged as feature request. The site developers monitor questions tagged as feature-request so they will see both this and the votes that people have left for the feature to be implemented.
(Don't be alarmed if people down vote it - votes here work differently than on the main sites)
Answer: If there really is a need for adding a picture to a comment (which I doubt due to the nature of comments here), there is always the possibility to add a link to the picture uploaded somewhere.


My red eared slider turtle won't grow

Question: I have a red eared slider turtle, who won't grow. I've had my turtle for 10 months. It's about 2 inches. Also, the bottom shell is soft and squishy. Please help. I want to help my turtle.
Comment: For a soft shell please first check your light set up. The turtle needs the right kind of light rays so it can process vitamin D from it's food. This vitamin makes bones and shell more solid and if missed will cause soft and deforming shell.
Comment: Have a look to this question for more information: https://pets.stackexchange.com/questions/26456/shell-of-the-turtle-is-progressively-darkening/26465#26465
Answer: Here is what I've been able to find about this turtle:

A male red-eared slider reaches sexual maturity when his shell is approximately 4 inches long. Depending on nutrition, that's between the ages of 2 and 5 years. A female's upper shell must reach 6 to 7 inches in length before she's sexually mature, which occurs between the ages of 5 and 7 years.

(Source)
Based off that finding, it sounds like your turtle is growing at a normal rate.  From your question, I don't know the age or sex of your turtle, but if its within its first year, I think its growing just fine.  Make sure that it gets proper nutrition to help ensure that it grows at the expected rate.
I've found a video that discusses turtle shell health.  One of the things mentioned that could make a shell soft on the top and bottom is shell rot.  This could be indicated by pink/white spots on the shell.  There is too much information to list here in that link, but check it out.  Typically, poor conditions cause shell rot for turtles in captivity.  They provide a home remedy for mild shell rot, but its not guaranteed.  The video above also shows what a healthy turtles shell should look like.  If it looks similar, there could be something else going on.

My red eared slider turtle won't grow


SHA1 fingerprint already used by another OAuth2 client

Question: Some time ago I created a project in Google Developers Console with Oauth2 client id for android app with package name and SHA1 fingerprint. Somehow the project got created without project id, which prevented me from deploying it to App Engine. I deleted the project, recreated it and now trying to add a new client id with the same package name and SHA1 fingerprint. A month after deleting the original project I'm getting "The signing fingerprint you specified is already used by another Android OAuth2 client".
Is there a way to reuse package name and SHA1 fingerprint with the new project?
Comment: See answer this https://stackoverflow.com/a/60204749/4997704
Answer: This doesn't sound like a SO resolvable issue.
It seems like your SHA1 fingerprint is still associated with a deleted project (which is probably in limbo). Google Support is the only one who can help you.


When to use threadlocker?

Question: Despite the use of threadlocker being somewhat widespread (e.g. repair videos), I have yet to see a single recommendation to use it in any service manual. Perhaps this is my relative inexperience, but I thought I'd ask the community out of curiosity - do you use threadlocker? If so, what is your criteria for deciding which bolts receive threadlocker and which ones do not?
Answer: It depends on the vehicle but it's not uncommon to see threadlocker specified for assembly.
Use threadlocker when it's called for.  Today many modern vehicles use one-time-only fasteners instead of threadlocker so it may be less common now than it was in the past.
I use threadlocker when the service manual says to, I replace fasteners when called for, and I just torque to spec when that is all that is specified.
Comment: I've known of some people who will reuse one-time fasteners and assume that if then just put threadlocker on them it will be ok.  That's NOT the case.  But some folks just do what they want.
Comment: I'm not quite sure where you're coming up with a correlation between using threadlocker and one-time-only fasteners?
Comment: One-time-fasteners are usually torque-to-yield, which don't use threadlocker.
Comment: @jwh20 Ahh ok. I guess it's just the cars I've worked on in which I've seen no mention of threadlocker in a manual.
Comment: @Paulster2 - Only other one-time fasteners I can think of are exhaust bolts/studs, but I also haven't seen threadlocker prescribed for those.
Answer: The main places I have seen the required use of Threadlocker or Retaining Compound (e.g. Loctite 638) specified in a car repair manual is on the splines of driveshafts.
I have also seen a band of threadlocker already in place on new bolts that are used to hold brake callipers on.
Comment: Damn, well that makes it easy.

When to use threadlocker?


Does the remove --purge command completely removes the installed package?

Question: If I use the remove --purge command does that completely erase the package and the configuration files from my system?
Answer: From the apt man page:

Removing a package removes all packaged data, but leaves usually small (modified) user configuration files behind, in case the remove was an accident. Just issuing an installation request for the accidentally removed package will restore its function as before in that case. On the other hand you can get rid of these leftovers by calling purge even on already removed packages. Note that this does not affect any data or configuration stored in your home directory.

So to answer your question, yes.
Comment: Note that ***this does not affect any data or configuration stored in home directories.***


Should we actively recruit in discussions on Area51?

Question: Over on Area51's discuss section, I just encountered this thread, which is actively recruiting on its prop page. However, due to the new system the question spills over. Is recruiting on-topic or should it be discouraged? If on topic, should we tag as recruitment, or would this be a meta-tag?
Answer: Since we have rid ourselves of the comments, I have used discussions to get the followers of proposals moving, especially on proposals that are reasonably close to going into the commitment stage.
If we allow such messages, though, then the questions become cluttered on https://area51.meta.stackexchange.com/ which is not good.
What can we do on the proposal to contact and reach followers, as a call to action, that won't clutter up the general discussion area?
Answer: The Area 51 discussions weren't really created for users to recruit followers or promote someone's proposal to the participants. The forum was provided to discuss specific problems with proposals. Nobody wants to wade through pages and pages of "hey, come vote on my stuff" posts to see if there are any  real issues needing attention.
You can imagine what a mess this site (meta.stackoverflow) would be if Stack Overflow users came in here to recruit users to answer their questions and vote-up their posts. The same general analogy applies to the Area 51 discussions.
The basic commenting feature will soon be restored to Area 51 proposals, but even that is going to be somewhat limited in its usage. To extend the Stack Overflow analogy, you expect "Please vote up my answer" comments to be somewhat frowned upon. The same ideas of appropriate use apply to Area 51.
Comment: @mfg: They should just be close. Tagging off topic content just encourages more of that type of post.
Comment: I have no real opinion on it, but would tagging those questions, thus making it so they can be filtered out, be a workable situation?  Or should they just be closed?


moving changed files to another branch for check-in

Question: This often happens to me: I write some code, go to check in my changes, and then realize I'm not in the proper branch to check in those changes. However I can't switch to another branch without my changes reverting. Is there a way to move changes to another branch to be checked in there?
Answer: Updated Answer
No need to use stash command. uncommitted changes do not belong to any branch so just use git checkout -b <new-branch>

Orginal Answer
git stash is your friend.
If you have not made the commit yet, just run git stash. This will save away all of your changes.
Switch to the branch you want the changes on and run git stash pop.
There are lots of uses for git stash. This is certainly one of the more useful reasons.
An example:
# work on some code
git stash
git checkout correct-branch
git stash pop

Comment: No need to stash uncommitted changed, they go with you when you check out a branch.  Stash is more for longer term storage of temporary things (stuff you want to finish and commit later, but you need to do something else right now).
Comment: @Tekkub That is only true if the branch you are switching to is up to date with the branch you are on. If for example you are accidentally working on prod branch and need to switch to stage branch but stage has changed in the mean-time stash is the only way to make the switch.
Comment: @Tekkub "longer term storage of temporary things" that saying feels very awkward, another point to use stash is it pushes it in a stack so if you don't want it to carry over and work on something else it is useful in that way. Yes you don't have to but just feels cleaner and more in control.
Comment: I get this. So I have to stash, switch branch and then pop

`C:\kf [develop +0 ~4 -0]> git checkout feature/customers
    error: Your local changes to the following files would be overwritten by checkout:
            AspWebApp.vNext/global.asa
            RestApi/Web.config
    Please, commit your changes or stash them before you can switch branches.
    Aborting`
Comment: bravo baby! should append what you should do if you made the commits
Comment: Using stash has one big disadvantage. If you must merge after the stash pop, then the diffs are a mess: LOCAL and REMOTE are mixed up; at least with Git Extensions and Perforce P4Merge. REMOTE or Theirs is your stash and LOCAL or Ours is someone elses code from the branch. Do you still get it? So I prefer Amber's approach.
Comment: @bill You are awesome.  This worked like a charm.  Of course I didn't have very many edits before I discovered that I was on wrong branch.  Life-saver.
Comment: @Tekkub the real answer's in the comments ;)
Comment: Instead of using `git stash pop`, it's safer to use `git stash apply` and when all the changes are applied to your desired branch, then you could run `git stash drop` to drop stash. This helps you to not lose changes when there are merge conflicts. If you use `git stash pop`, you might end up losing some changes in case of conflicts.
Comment: _"...you might end up losing some changes in case of conflicts"_
**No comments on this??!** @Atherion, I agree `stash` seems like a good command workflow.
Comment: Your last comment is not correct. If I want my changes to depend on my main branch, I need to first be able to switch to that branch. Otherwise it causes all sorts of other issues and changing the branch a branch depends on has not worked for me. The stash-ing works, though. Great!
Answer: If you haven't already committed your changes, just use git checkout to move to the new branch and then commit them normally - changes to files are not tied to a particular branch until you commit them.
If you have already committed your changes:

Type git log and remember the SHA of the commit you want to move.
Check out the branch you want to move the commit to.
Type git cherry-pick SHA substituting the SHA from above.
Switch back to your original branch.
Use git reset HEAD~1 to reset back before your wrong-branch commit.

cherry-pick takes a given commit and applies it to the currently checked-out head, thus allowing you to copy the commit over to a new branch.
Comment: **changes to files are not tied to a particular branch until you commit them.** <-- this. This solved a mystery for me. Thanks.
Comment: You shouldn't even need to cherry-pick here.  `git reset HEAD~N --soft` and then `git checkout -b` to move all the _now_ uncommitted code to a new branch.
Comment: I get the following error when trying to switch branches: "local changes to the following files would be overwritten by checkout". So, it doesn't seem like I can move to a different branch and commit normally.
Comment: @Mischa it does not work if you are switching between two branches that have different histories
Comment: @Aaron that's much nicer (for the post-commit scenario)! Please make a separate answer.
Comment: But in my case I can't change the branch it aborts, ask to do something about changed files
"error: Your local changes to the following files would be overwritten by checkout:"
Answer: Sadly this happens to me quite regularly as well and I use git stash if I realized my mistake before git commit and use git cherry-pick otherwise, both commands are explained pretty well in other answers
I want to add a clarification for git checkout targetBranch: this command will only preserve your working directory and staged snapshot if targetBranch has the same history as your current branch

If you haven't already committed your changes, just use git checkout
  to move to the new branch and then commit them normally

@Amber's statement is not false, when you move to a newBranch,git checkout -b newBranch, a new pointer is created and it is pointing to the exact same commit as your current branch.
In fact, if you happened to have an another branch that shares history with your current branch (both point at the same commit) you can "move your changes" by git checkout targetBranch
However, usually different branches means different history, and Git will not allow you to switch between these branches with a dirty working directory or staging area. in which case you can either do git checkout -f targetBranch (clean and throwaway changes) or git stage + git checkout targetBranch (clean and save changes), simply running git checkout targetBranch will give an error:

error: Your local changes to the following files would be overwritten
  by checkout:
          ...
  Please commit your changes or stash them before you switch branches. Aborting
Answer: A soft git reset will put committed changes back into your index. Next, checkout the branch you had intended to commit on. Then git commit with a new commit message.

git reset --soft <commit>
git checkout <branch>
git commit -m "Commit message goes here"

From git docs:

git reset [<mode>] [<commit>] This form resets the current branch head
  to  and possibly updates the index (resetting it to the tree
  of ) and the working tree depending on . If  is
  omitted, defaults to --mixed. The  must be one of the following:
--soft Does not touch the index file or the working tree at all (but resets the head to , just like all modes do). This leaves all
  your changed files "Changes to be committed", as git status would put
  it.
Comment: As others pointed out before, this will only work if the two branches you're switching from/to have identical history.
Answer: If you created new files you can do this:
git checkout main
git checkout -b branch-b
git checkout branch-a :rel/path/to/yourchangedfiles
git commit -m "w"
git checkout branch-a

git checkout main :rel/path/to/yourchangedfiles

# if this happens:
error: pathspec ':rel/path/to/yourchangedfiles' did not match any file(s) known to git

# then just rm the folder
trash-put rel/path/to/yourchangedfiles


When is a practice said to be Haraam

Question: Asalamu Alaikum
Please On whose authority is something/practice forbiden considered Haraam;Allah SWT, the prohet Alaihim Salam or from both.
Answer: God alone is the one who can decree anything as haram.  But given that God's forbiddances are done through the words and actions of the prophet — the messenger of God — what the prophet declares haram is considered so done under and with God's full authority.
The Hanafi school makes a distinction between Haram (forbidden) and Makruh Tahrim (prohibitively disliked).  Only those acts which are indisputably forbidden (e.g. via Qur'an or mutawattir ahadith) are classified as haram.
Acts which are (apparently) prohibited by the prophet, but which fail to reach the criteria of mutawattir, are classified as makruh tahrim.  Such acts are still effectively forbidden and considered sinful, but if one refuses to accept the ruling it would not be considered as rejecting Islam as such rulings are based on speculative (rather than definitive) evidence.
To the best of my knowledge, this is unique to the Hanafis; other schools make no such distinction and treat all such as mutually haram.

When is a practice said to be Haraam


Game Data Files security in unity

Question: I have some game data files in PDF, excel, and video format. Is there any way to make it secure? Through encryption? I have almost encrypted my all files in .aes encryption format but there is a huge problem i have to decrypt it each time when i have to show it to the user ! Therefore I have to place it inside file explorer and anyone can access it. How do I prevent it?
Comment: If the data is in the hand of the user, he can access it. You can only make it harder for him but not prevent it totally.
Comment: You may be interested in [Is it worth it to encrypt data?](https://gamedev.stackexchange.com/q/88458/39518)
Comment: yes, exactly I want to make it harder for him to decrypt at least.
Comment: For 99% of the users, it is probably enough if you just encode/ save your data as a byte stream. It is not a true encryption but makes it not possible to read/ write the file by a normal file browser. But what are you in the end trying to prevent? That the user is changing data (for different gameplay/ cheat), that he can access it at all or something else?
Comment: There is one excel file where he create users/roles. While there are some other excel files contains some data open in excel, or some pdf and video files.
Comment: Actually if i have to open excel file or pdf i am using Application.OpenURL that required file on harddrive.
Answer: First things first: if the data is in the user's hands (stored on their device or even just displayed), they have access to it and it should be treated as such. That means regardless of what kind of encryption you employ, if they spent enough time, they can / will always be able to get it. All you can do is make it harder for them.
Now you noticed it yourself already that encrypting is already a performance issue for you. But is that really needed? Since we know that if they really want that they can get the data, we actually just need to prevent first 99% of the users to casually read the data. Storing it in a format that is easy to read (for your application) but hard for the user (file manager) is rather trivial. Instead of saving it as a common type (like .xsl, .xml, .pdf) just store it as a byte stream.
Now the harder part: what are you trying to prevent? In case you want to prevent manipulation of fixed assets (like values for stats, scores, saves), in addition to storing the file you can store a hash. On load you compare the hash of it to the file (you would rehash the file) to make sure they are equal. This does not prevent manipulation totally since if the hash is local, it can be manipulated as well. Just another layer of making it harder.
If you want to prevent theft of assets, this is even harder. The easiest way would be probably to not use any common format but have a custom developed one. If you are the only one that uses the format, it reduces the chance that others are willing to spent the effort trying to find out how to use them. Again just making it harder.
If you want to prevent the loss of sensitive data, do not store it locally at all. Keep it on your own server to make a data mining of it harder.
Comment: A couple of notes here: deterring casual users from reverse engineering your data themselves doesn't deter that single dedicated hacker from doing it and releasing a one-click cracking application that automates it. So now even your most casual users can access and modify any data the most dedicated hacker can. The only way to fully protect game data from being modified to cheat is with an authoritative server. Also, a common way to rip visual assets from a game is to intercept rendering calls at the driver level, so no amount of obfuscation of the stored data on disc will deter that.
Comment: if i store it in byte stream then how to show it within excel or pdf viewer? I definitely need to convert it and then need to store on the hard drive of the user?

Game Data Files security in unity


If the Wealth-By-Level is an indication of the value of Magic Items for Player Characters, does the WBL for NPCs have the same purpose?

Question: If the Wealth-By-Level is an indication of the value of Magic Items for Player Characters to use in combat, does the WBL for NPCs have the same purpose, or is it there for some other purpose (to provide treasure for PCs, say).
Answer: WBL for NPCs
The WBL for NPCs is largely to give NPCs the kind of adventuring gear expected (or required) by adventurers to present a challenge (either to PCs, or as allies when fighting other NPCs).  A Wizard without a spellbook, or a Fighter without arms and armour are easy meat and do not correctly reflect their Challenge Rating.
The WBL for NPCs is not intended to override the normal treasure guidelines in the WBL entry in terms of loot for encounters/expected WBL, and NPCs receive less WBL than PCs partially due to this concern.
Comment: @jack_lesnie does this mean that a tricked out NPC defeated by players would present a larger treasure reward because it contains the normal treasure from the encounter + the NPC gear?

Should this be mitigated by a few treasure less fights to make up for the NPC horde?
Comment: There is no +. The NPC has its WBL, and the PCs find the loot they are entitled to. You can use some of the NPC's WBL on temporary effects like potions, and "burn" it ahead of time, or simply give less wealth in further encounters. If the NPC uses items the PCs can't use, they have to sell them for half price, and so get less value as well.
Comment: To make it absolutely clear: The NPC's WBL *is* the treasure that PCs get for defeating them. If part of an NPC's wealth is something players can't claim (perhaps because it's a large, fixed structure in a collapsing demiplane), that part doesn't count as part of the NPC's wealth - but anything the players can shove into their bag of holding before running to the exit portal does.


How to interpret importance of random forest model, Mean Decrease Accuracy and Mean Decrease Gini?

Question:
A random forest model outputs the following importance values. How do I interpert them for feature selection? If it's the mean decreased accuracy does that mean that by removing them from the model the accuracy should increase?
Answer: I'm not sure which software you're using so I don't know the details, but generally it's simple: the highest values indicate the features which contribute the most to the target.
In particular, the mean decrease in accuracy shows how much the accuracy decreases when removing this feature. Thus again a high value (e.g. emotionality in your example) indicates an important feature for predicting the target.
Answer: Good afternoon @FOH, making a quick summary of the selection of resources would be to remove the resources that are not useful for anything. It does not improve model accuracy. It has no relationship with other attributes are in the set without need.
Best way to interpret it would be to plot a graph for
every type you got. Facilitating your analysis of the resources you are using to improve the model. Many of these features are noise, they can also be a burden for processing when we train the model taking more time. An interesting way to make a comparison is to put the whole set to train to capture time and measure its accuracy and then select the features with the best performance, pass the model again, perform the same captures and compare whether there is an improvement or not. Carrying out these observations you could see which will be the best to select.
Searching I found a very good explanation for selection using SelectFromModel from SK-Learn, where you can perform the selection and analyze.
Feature Selection Using Random forest
SelectFromModel SK-Learn
Another very good tool that can help you is yellowbrick this tool helps a lot. I'll put a link below has a very good example with Gradient Boosting Classifier
YellowBrick Model Selection


Are sins of the future forgiven? John 20:23

Question: Does John 20:23 use a past-tense verb, i.e. "forgiven"? I was wondering what information there is on the verb "forgiven" here.
Comment: Welcome to Biblical Hermeneutics Stack Exchange! Be sure to take our [site tour](http://hermeneutics.stackexchange.com/tour) to learn more about us. [We're a little different from other sites.](http://meta.hermeneutics.stackexchange.com/a/803/423)
Comment: We don't do 'Bible study' - we study the Bible. That means we stop short of application when answering questions about the Bible (which means we don't fully exegete the text in the religious sense of the practice). [Questions should be focused solely on the text](http://meta.hermeneutics.stackexchange.com/q/207/423) and not primarily on those things to which the text applies.
Comment: This question boils down to what tense the verb was in in this verse, which is a relatively simple linguistic question and a simple yes or no won't really help you with your original question, which is focused on application. I've gone ahead and transferred this to C.SE for you where you will receive a better answer to what you are looking for.
Comment: I've also reworded the question to focus it exclusively on this text and not on those things to which it applies, and also to keep it from searching for other texts (questions must be focused on a specified text). That way you can now get answers to the language question here and the theological question on C.SE. For more information on why we do this, check out [Why can't I ask my 'big question'?](http://meta.hermeneutics.stackexchange.com/q/955/423)
Comment: @Daи I would have suggested a broader meaning of what "forgiveness" means, in context with the scripture. It still is a step away from application, but goes beyond a technical 'verb tense', which is is less than what the OP asked for. Thank you for allowing it to stay, as the answer addresses the OP's concern(w/o the 'church' element).
Answer: The tricky aspect of interpreting verses 21-23 involves the time (or timing) element. There are several things to keep in mind, particularly from the evangelical tradition:

Jesus, in one of His post-resurrection appearances to His disciples, intended by His enduement of the Holy Spirit to them to tide them over, as it were, until the Holy Spirit appeared at a plenary session of all the believers gathered in Jerusalem on the Day of Pentecost. Call it a temporary enduement which portended the baptism and the filling of the Holy Spirit some days hence.
The forgiveness of sins which Jesus spoke of in verse 23 was delegated to them in--again--the interim between the days following His resurrection and the Day of Pentecost. If anything, that forgiveness was in the future tense, not the past tense. This particular enduement enabled the disciples to share (and possibly teach and preach) the good news of Christ's resurrection with the people to whom they were closest at that time, whether relatives, friends, neighbors, or anyone in their circles of influence. In other words, the disciples' audiences had an opportunity to believe in the risen Messiah. If they did, their sins could be forgiven. If they refused to believe, their sins would be retained (though they would almost invariably be given a second chance later on to repent and believe).
The Pharisees and the experts in the Law were quite correct:

<code>               "'Who can forgive sins but God alone?'" (Mark 2:7 and Luke 5:21).
</code>

Since the forgiveness of sins is an authority which only God possesses, and then extends to whomever He will, the disciples' authority to forgive or retain sins was indeed delegated to them. A delegated authority carries a similar weight to the authority of the one who delegates, but that authority is derived from the delegator! It passes with the delegator's permission to the delegatees.
The disciples could, for example, legitimately say to a person who believed in the resurrected Christ:

<code>               "On the basis of the authority of the risen Christ
               given to us, your sins are forgiven." Or conversely,
               "On the basis of the authority of the risen Christ
               given to us, your sins are retained."
</code>

Even today, Christ's followers can say to a person whom they lead to the Lord,

<code>              "On the authority of Jesus and His word,
              as recorded in the Scripture, if you truly
              believed in Jesus for the forgiveness of your
              sins, those sins are forgiven."
</code>
The forgiveness proffered by the disciples prior to the "birth of the Church on Pentecost" was therefore to a special category of believers (or unbelievers). Believers today are assured of the forgiveness of

every sin they committed in the past
every sin they commit in the present, and
every sin they ever will commit in the future

Christ

"died for our sins according to the Scriptures . . ." (1 Corinthians 15:3b NIV).

Paul made it crystal clear in another place, however, that because all our sins--past, present, and future--are forgiven, we are not, therefore, free to commit sins to our heart's content. In his letter to the Roman Christians, Paul asked the question,

"What shall we say then? Shall we continue in sin, that grace may abound ? God forbid  . How shall we, that are dead to sin, live any longer therein ? Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life (6:1-4 KJV).

The forgiveness proffered to every living creature who believes in and receives Christ is not a free pass to continue living in sin. On the contrary, out of gratitude for our sins being forgiven, we are to live in "newness of life."
While today we can never truly know who has been forgiven and who has not been forgiven (though a lack of spiritual fruit in a person's life could be an indication of his or her spiritual standing before God, as Christ indicated in Matthew chapter 7, verses 16 and 20), we are given both an assurance and a warning in 2 Timothy 2:19 NAS:

"Nevertheless, the firm foundation of God stands, having this seal, "The Lord knows those who are His," and, "Everyone who names the name of the Lord is to abstain from wickedness."

In other words, we need to spend less time trying to determine who is the true believer and who is not, and more time abstaining from wickedness! As Jesus said, we are to let the wheat and the weeds grow up together and not go around removing the weeds from our respective churches. That is Jesus' job! Since we can't absolutely know--nor do we need to know--who the "weeds" are, we are to take care to grow as healthy stalks of wheat and produce to God's glory many grains of wheat. As Peter encouraged us in his first letter,

"Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall" (2 Peter 1:10 KJV).
Comment: I believe you are missing a "not" in this sentence: "Paul made it crystal clear in another place, however, that because all our sins--past, present, and future--are forgiven, we are [not?] therefore free to commit sins to our heart's content." Correct?
Comment: @ScottS: It was SURELY an error! (I imagine, however, that more than a few people wish they were free to sin with impunity. The pleasures of sin, however, are for a very short season, but at God's right hand are pleasures forever more. See Psalm 16:11 KJV, and Hebrews 11:25.)
Comment: @rhetorician Good answer, Don. I agree w/ScottS, an "Are" needs to be included before "...we are therefore...". It's too small of an edit(less than 7 characters) so you will have to do it. Otherwise-+1.
Comment: I could tell by your follow up paragraph after the scripture quote that it had to be a "error" in the statement. But I did not want to _assume_ that, which is why I did not just make the edit myself.
Comment: @rhetorician, "more than a few people wish they were free to sin with impunity." I met a man who practiced that. He stated that because grace abounded when he sinned, his sins made more grace in his life. Some interpretations are so wrong you just can't fix them.
Comment: @ScottS: Wow! What a blunder! Rest assured I'm not an antinomianist. Thanks for the correction. Don
Comment: @user2479: See my comment to ScottS. Thanks for your correction and for your encouragement. Don
Answer: The verse in Greek is as follows:

John 20:23 (GNT)
23 ἄν τινων ἀφῆτε τὰς ἁμαρτίας ἀφέωνται αὐτοῖς, ἄν τινων κρατῆτε κεκράτηνται.

First, whenever looking at "tough" passages in the Greek New Testament, one important step is to check the most recent research regarding the texts. That is, there is apparent confusion on the exact verb tense of the second iteration of ἀφίημι which is highlighted in bold, above. In other words, the variant readings of the variant texts concerning this verb will confuse our understanding of the interpretation (and therefore any application), unless we consult primary sources.
According to The Greek New Testament (4th Edition), edited by Aland, Metzger, et al. (2012), this verse in Greek has variant readings from various primary sources (papyri, manuscripts, etc.). In order to save ourselves the tedious task of comparing and contrasting the pros and cons of the variant readings, the late Bruce Metzger has also published the companion volume, which is A Textual Commentary on the Greek New Testament (2nd Edition, 2012). On page 219 he writes the following:

20.23 ἀφέωνται {B}
  Although the perfect tense ἀφέωνται could be regarded as a secondary assimilation to κεκράτηνται at the end of the sentence, a majority of the Committee interpreted the present tense ἀφίεωνται and the future ἀφεθήσεται as scribal simplifications which weaken the sense. To the external evidence supporting (אc , A D (L) X 050 f1 f13 33vid 565 al) should perhaps be added B*, which reads (ιο being written for ω).

What he is saying, is that the "Editorial Committee" (comprised of the four editors of The Greek New Testament) had ascribed {B} to the reading for ἀφέωνται, which means that they are "almost certain" that the perfect tense was the original word in the autograph. In other words, the present tense (ἀφίεωνται) and future tense of the verb (ἀφεθήσεται), which are the variant readings, were later scribal editions or emendations to "correct" what they (copyists over the centuries) had inferred what should be the appropriate reading based on theological biases. Thanks to the research of Metzger, et al., we now can be "almost certain" that the NASB translation, below, is the most accurate rendering of this verse from the best Greek texts available for the New Testament.

John 20:23 (NASB)
  ". . . Receive the Holy Spirit. 23 If you forgive the sins of any, their sins have been forgiven them; if you retain the sins of any, they have been retained."

So now what does the verse mean?
The verse does not appear to refer to the authority of believers on earth to forgive the sins of others, because the verb form is in the perfect tense (ἀφέωνται), for which Metzger, et al., are "almost certain" is the correct reading.
So what is the meaning of the verse if sins have been forgiven (absolute sense), but they can still be retained (temporal sense)?
The interpretation appears to refer to the authority of believers on earth to accept or reject believers in community fellowship (temporal sense) even though the sins of those believers have been forgiven (absolute sense).
To start, whenever believers sin in the eyes of other believers, the admonition is for the spiritually mature believers to "restore" them.

Gal 6:1-2 (NASB)
1 Brethren, even if anyone is caught in any trespass, you who are spiritual, restore such a one in a spirit of gentleness; each one looking to yourself, so that you too will not be tempted. 2 Bear one another's burdens, and thereby fulfill the law of Christ.

You pray for other believers, and ask the Lord to "restore" them from their sins, for which they were already forgiven (perfect tense of ἀφέωνται in John 20:23). The obvious implication is complete forgiveness. But there are sins, which other believers commit, that should cause grief to others.

1 Cor 5:1-3 (NASB)
1 It is actually reported that there is immorality among you, and immorality of such a kind as does not exist even among the Gentiles, that someone has his father's wife. 2 You have become arrogant and have not mourned instead, so that the one who had done this deed would be removed from your midst. 3 For I, on my part, though absent in body but present in spirit, have already judged him who has so committed this, as though I were present.

Jesus also mentions the tolerance of gross sexual immorality among Christian fellowship.

Rev 6:18-21 (NASB)
18 "And to the angel of the church in Thyatira write: The Son of God, who has eyes like a flame of fire, and His feet are like burnished bronze, says this: 19 'I know your deeds, and your love and faith and service and perseverance, and that your deeds of late are greater than at first. 20 But I have this against you, that you tolerate the woman Jezebel, who calls herself a prophetess, and she teaches and leads My bond-servants astray so that they commit acts of immorality and eat things sacrificed to idols. 21 I gave her time to repent, and she does not want to repent of her immorality.

In other words, believers should "retain the sins of others" when matters pertain to the tolerance of gross sexual immorality (and its handmaiden, idolatry) within the fellowship of Christians.  (Please click here for amplification of gross sexual immorality and idolatry.) It is not that these Christians are not saved, and therefore forgiven, but that their sins are not tolerated, and in this temporal sense, are retained.
For example -

1 Jn 5:16-17 (NASB)
16 If anyone sees his brother committing a sin not leading to death, he shall ask and God will for him give life to those who commit sin not leading to death. There is a sin leading to death; I do not say that he should make request for this. 17 All unrighteousness is sin, and there is a sin not leading to death.

John is making allusion to the same distinction between the "restoration" of the believer and the "retaining the sins" of the believer. Like the believers in Corinth or the believers in Thyatira, gross sexual immorality (and its handmaiden of idolatry) should not be tolerated among the community of believers. These sins should be "retained" and therefore fellowship broken in the temporal sense, even though in an absolute sense sins were forgiven at the cross (that is, per the perfect tense of ἀφέωνται in John 20:23).
ADDENDUM
The following two passages reinforce the discussion in the previous paragraphs, above.

Matt 18:15-18 (NASB)
15 "If your brother sins, go and show him his fault in private; if he listens to you, you have won your brother. 16 But if he does not listen to you, take one or two more with you, so that by the mouth of two or three witnesses every fact may be confirmed. 17 If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector. 18 Truly I say to you, whatever you bind on earth shall have been bound in heaven; and whatever you loose on earth shall have been loosed in heaven.

The context is broken fellowship among believers because of sin, which is of such a degree that temporal cessation of fellowship occurs. The context is not about forgiving people (or not forgiving them) so that they can enter heaven (or not enter heaven).
And then there is this passage -

Matt 16:15-19 (NASB)
15 He said to them, "But who do you say that I am?" 16 Simon Peter answered, "You are the Christ, the Son of the living God." 17 And Jesus said to him, "Blessed are you, Simon Barjona, because flesh and blood did not reveal this to you, but My Father who is in heaven. 18 I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it. 19 I will give you the keys of the kingdom of heaven; and whatever you bind on earth shall have been bound in heaven, and whatever you loose on earth shall have been loosed in heaven."

Peter was the "stand-in" for Jesus at Pentecost, when the New Covenant was announced to Israel. (The dates of the announcement of the Old Covenant and the New Covenant were the 6th of Sivan, which was 50 days after the 16th of Nisan - please click here.) So while Moses announced the Old Covenant, Peter announced the New Covenant. The New Covenant is the key to heaven. Please note that the key to death and Hades is not possessed by Peter, but by Jesus (Rev 1:18).
In other words, the New Covenant is about the keys to heaven (forgiveness of sins in the absolute sense). Gross sexual immorality and/or its handmaiden of idolatry are not tolerated and therefore believers hold one another accountable (binding) in order to preserve the fellowship of saints.
It is Jesus who unlocks the power of death and Hades to save sinners (with the key of death and Hades). The key of heaven is the New Covenant, for which there is absolute forgiveness, but with gross sin (within the fellowship of saints) will come accountability, and therefore the binding of those sins on earth. The story of Ananias and Sapphira provide an extreme example of such accountability (Acts 5:1-11), which had idolatry in view.
Answer: The literal Greek is:

ἄν - If  τινων - of any ἀφῆτε - you may forgive τὰς -
the ἁμαρτίας - sins ἀφέωνται - they are forgiven αὐτοῖς -
to them ἄν - If τινων - of any κρατῆτε - you may
retain κεκράτηνται - they have been retained

ἀφέωνται - they are forgiven - is not in the past tense.  It is the present tense, passive voice:

ἀφίεται (aphietai) - he/she/it is forgiven ἀφίεσθε (aphiesthe) -
you (plural) are forgiven ἀφίενται (aphientai) - they are
forgiven


Routing one wireless router to another wireless router with internet access on both

Question: I have an Asus wireless router wired to ADSL that provide Internet access, this router have also a print server (USB printer) and a 1 Terabyte DLINK NAS wired to this router. I have also a wireless Zalip 3G router with a 3G Internet key connected. The computers and tablets around the house (4 notebooks, 3 tablets and 1 desktop computer) are wireless networked,  according to the strength of the wireless signal from one or other router, but when one computer is served by one router it can not connect to computers served by the other router. How can I resolve this? How to route one router to the other one?
Comment: What models are these routers?
Comment: Please post model and revision of your ASUS router (is it with ADSL modem integrated or there is something more?) Since it has USB port odds are high that with extra USB hub and aftermarket firmware you can attach 3G USB stick for "multiwan" and eventually an USB hard disk for SAN.
Answer: It's not likely that the routers' stock firmware supports this sort of network configuration.  Custom firmwares such as DD-WRT may have this capability, though.  See the following links for more info:
http://www.dd-wrt.com/wiki/index.php/Client_Bridged
http://www.dd-wrt.com/wiki/index.php/Wireless_Bridge  (OLD VERSION)


How Can I Help AOMEI Partition Assistant Standard Edition Find My Drive I Want To Migrate My OS To?

Question: I'm trying to replace my failing SSD with a Seagate 2TB BarraCuda SATA 6 Gb/s 7200 RPM 64MB Cache 3.5 Inch Desktop Hard Drive (ST2000DM006).
I've made sure that my motherboard is compatible and it is. My motherboard is a MSI           B85M-G43 (MS-7823) which after looking it up is SATA 6 Gb/s (3.0) compatible.
I'm using a StarTech USB 3.0 to SATA adapter (USB3S2SAT3CB).
Right now AOMEI Partition Assistant can't seem to see the new HDD when I connect it with the adapter.

You can see the C drive as well as my external drive but it's not seeing the one I've hooked up with the adapter. It would show as unallocated if it did.
I'm not really sure where the failure is. My system beeps to register that I've connected something and AOMEI Partition Assistant will prompt a reload when I do, so it is connecting.
If it's the software I'm not sure where to check it. I'll be contacting their support after I post this. I'll update this post when I do so hopefully others who might have the same issue can learn from it.
After that I'll try to contact StarTech in case it's the adapter.
If anyone has some ideas I could try I would love to hear them.
Answer:
I'm not really sure where the failure is.

Your using a 2.5" adapter with a 3.5" Drive. That's never going to work.  You are not supplying enough power to the drive.
This isn't a software issue.  You should be connecting the drive over SATA.


How to Conduct a performance test for more than 100K users

Question: Currently we want to conduct a performance test for more than 100k users. I am comparing some tools like Jmeter/Gatling/Tsung/nGrinder, which one will be suitable for us?
Comment: what performance? a web application ?
Answer: This kind of test is impossible to do locally or using only one machine.
You can use JMeter Distributed features to achieve this scale.
It is not an easy task, but it is doable.
An introduction to this feature can be found here:
http://jmeter.apache.org/usermanual/remote-test.html
Answer: All of them can be run in clustered mode so theoretically any will fit.
Looking into Open Source Load Testing Tools: Which One Should You Use? article:

JMeter and Tsung seem to perform better given the same hardware so you can stick to one of them. Be aware that Tsung can be installed on limited number of operating systems, as per documentation theoretically you can run Tsung on Windows

This package has been tested on Linux, FreeBSD and Solaris. A port is available on Mac OS X. It should work on Erlang supported platforms (Linux, Solaris, *BSD, Win32 and Mac OS X).
On Mac OS X you can install Tsung via Homebrew (http://brew.sh/): brew install tsung.

However as per Installing TSUNG on Windows message

Tsung has to my knowledge never been run on Windows.
  You have to deploy an SSH server so that Tsung can launch other nodes
  if you want to run it in cluster. You have to rewrite the various
  scripts (they might run under cygwin) and possibly change a few things
  in the code.
Note also that platform is also less scalable (Erlang does not support
  kernel polling on windows) that's probably the reason why no one
  really cared running it on MS system.

So most probably you should stick to Apache JMeter, check out Remote Testing user manual chapter and JMeter Distributed Testing Step-by-step guide for more information.
Comment: JMeter use thread to simulate on vuser. We can conduct over 2K for one cluster. Tsung use coroutine to simulate request while gatling use AKKA Actor model to do it request sampling. I am not sure these two method will conduct more requests in one cluster than Jmeter does?


I'm very late to applying for postdocs because I was aiming for industry jobs and didn't think I needed one - how much trouble am I in?

Question: I'm about a month away from my PhD defense, and my goal is to work in industry (I'm in medicinal chemistry and I've been doing high-throughput screen and in vitro inhibition assays of a particular enzyme). I started job searching in industry about a month ago, thinking that I shouldn't have problems finding suitable positions. However, as I've started searching and applying, I've noticed that a lot of the jobs in biopharma that are posted require things like mammalian cell culture work, transfection, genomics, immunology etc., which I don't have experience in. Therefore, I'm thinking that I may need to do a postdoc after all to gain experience in those areas - there's some very important skills that I'm apparently missing! Of course, if I get an industry offer, I'll go ahead and take it, but it seems like I may not be qualified for PhD-level positions (I'm open to taking a MS-level position but most employers would consider me "overqualified"). But it's a month before my defense and it's rather late in the game when it comes to postdoc apps. My advisor can only fund me for another 2.5 months (end of June). How much trouble am I in in terms of getting a postdoc that is rather significantly different from my PhD? How long of a gap is acceptable to potential postdoc PIs?
Comment: Job descriptions are often "wish lists" -apply anyway!
Comment: Why do you need to do a postdoc to learn those skills? Can't you learn them in an industry job for 3x the salary?
Comment: @astronat I'm planning on applying to both industry jobs and postdocs at this point. I would very happy if industry were to train me, but I'm not sure if they'd be willing to when they have many other candidates who already know those things. I've also heard that not all postdoc jobs pay the NIH minimum - some pay higher than that (usually ones not at academic institutions) and I'd be interested in those.
Comment: @8263xiao On some occasions, professors can redirect their funds from supporting a Research Assistant graduate student to supporting a postdoc. So if you see an announcement of graduate studentship in the area of your research -- give it a try: talk to the professor and enquire if (s)he can spend those dollars on a postdoc. This may work out.
Answer:
I started job searching in industry about a month ago

I am not familiar with your individual situation, but for any job search I would recommend allowing a minimum of three months.  If you expected to find a job within one month then you would be in very bad trouble.  Keep in mind that a job application often waits a month to be read and a job offer often takes a month to be approved by an employer.
The content of a job ad is not an accurate predictor of the qualifications of the person who is hired.
Look up the profiles of people who have the job you want.  That will get you data, as opposed to opinions.
Answer: How much trouble are you in: that really depends on what country you are looking for postdocs in. Positions open up at different times in different regions. For me, the academic year starts in September, so there are lots of postdoc positions being posted now.
However, if you want to work an industry job, then you are far better off just applying for them. Your skills are transferable, and what you don't know you will learn on the job. Your ability to learn quickly is more important than what you have already learned, especially when you are going to be applying for more junior positions anyway.
Don't be intimidated. Just go for it and most importantly, be open to change.
Comment: Not my field, but I suspect that the big industrial players (e.g. the Pfizers) will have structured training schemes available to fill in any skills gaps, whereas startups (and indeed postdocs) tend to talk about "hitting the ground running" and be stricter about looking for people matching their exact requirements.
Comment: I'm in the US. I get tons of conflicting advice over what to do. I'm currently applying to industrial positions but will be sending out postdoc apps in the coming week. I'm especially interested in postdocs in which I work with potential therapeutics in cells and/or ex vivo, which will provide a good bridge towards more biology-oriented industry positions (who tend to prefer those with postdocs anyways, or so I hear). So yes, I'm trying apply to both since my end goal is industry; it's just what I can get with the current market and what skills I need training for.


A program to make my computer do a certain thing on a website every 30 minutes for two days

Question: So I want to make my computer do a certain thing on a website every 30 minutes, for 2 days straight. I want my computer to post something on a site and the title have to show the time. Does anyone know a program that can do this?
I use Windows.
Comment: Developers would use [Selenium](http://www.seleniumhq.org/). Can you give a bit more of background regarding the knowledge of the user (i.e. you if I understand that right). Is programming ok or do you need a simple UI?
Answer: Here are the options I can suggest (in no particular order):

Selenium. This is an automation tool for web browsers. It is typically used by developers for running web site testing scripts, but can be used for any purpose that requires a repeatable action on a website. you would write a script telling it to "click on this, enter that, etc", and could run it repeatedly. It works with all the major browsers. You'd still need a separate tool to set it to run on a regular basis.
Sahi. Similar to Selenium. Arguably easier to use, but not as widely supported. It does still work in all the major browsers though. As with Selenium, you would still need a separate tool for scheduling it to run.
PhantomJS. This is a bit different to the others. Phantom is a "headless web browser"; that is, it's a fully functional web browser, but without a user interface. You can use it to navigate pages, but all interaction with it is done through scripting it, both for telling it what to do and for inspecting the resulting web pages. As with the other two tools above, it is frequently used for writing test scripts for web sites. It is considerably quicker at running its scripts than Selenium or Sahi due to not having the overhead of having to load a separate browser and not having to render the browser window on screen. The learning curve is steeper considerably though, so it will take you more effort to get it up and running. As with the others, you'll need a separate tool for automating it to run regularly.
WGet. Depending on your needs, you might not need anything of the complexity of the tools listed above. WGet is a very simple tool that does nothing else but to make a web request. If your automation need is a simple one -- eg just load a given page to activate an event on your site once a day -- then you may be able to achieve it just be loading the page; you don't necessarily need to have a browser doing anything with the page once it's loaded. In this case, WGet may be a better option than any of the others, just because it's so simple. Again, you'll need something else to tell it to run on a regular basis.

For all of the above, once you've written the script, getting it to run regularly can be achieved using the Windows Task Scheduler, which is built into Windows.
One final thing I would say: If the action you're performing regularly is an action on your own website, you might be better off having it done by the web server itself. In this case, assuming your server is running Linux, you'd need to use a cron job to perform the automation, but you wouldn't need any of the tools above, as your cron job could simply run the code on your site directly.
Answer: Since you said "website", you can use your browser to get the job done. Although Selenium can be used as well.
I'll be using browser.
Disclaimer: Intermediate Javascript knowledge is required to accomplish this.
Here these are your best friends, exploit them: setInterval, iframes, MouseEvents, KeyboardEvents
You go to target website, open browser's console and enter the script (more on that later).
Browser's main window/tab will keep your script running, iframes will act as a second layer sandbox for your script, because triggering clicks on main page might redirect to some other page thus stopping your script further.
And then use normal selectors and MouseEvents/KeyboardEvents to accomplish what you want.
Example:
This example script will upvote first reply posted on most recent thread on reddit.com/r/webdev
Warning: You must be logged into reddit
1. Open your browser (Tested on Chrome)
2. Go to reddit.com/r/webdev
3. Open console by CTRL + SHIFT + J
4. Paste the following code and hit enter (explained later)
You can leave now, just make sure browser is kept running.
What's happening??
The main helpers here are setInterval and iframes. Former keeps it looping and latter is used to execute scripts and the window itself is used to maintain environment.
Set the end time for the script
var endLoopAt = new Date('July 08, 2016 08:24:00');

Create a sandboxed environment, main window will be used to keep script running
var sandBoxedIframe = document.createElement("iframe");
sandBoxedIframe.onload = checkAndUpvote;
document.body.appendChild(sandBoxedIframe);

Used to check if the new most recent link is same as one checked during last run
var lastUpdatedFirstPostLink = "";

Rest of the script uses element selectors (You can use "inspect element" to find yours) and dispatches Events on them.


How do people with overwhelming financial difficulties convert?

Question: I have a sincere desire to convert Orthodox with my family and don't have the financial means to do so. My main question is how do people in these circumstances handle all the extra duties that are required, especially if the distance to a Shul is too great and moving is impossible. Are there steps they can take to begin the conversion or is that basically not an option?
Comment: Re: conversion, contact a competent  Orthodox Rabbi. Re: expenses, it is possible to practise Judaism without for example a silver kiddush cup and without embellishment which would keep the cost down. The title of your question uses the phrase "overwhelming financial difficulties". If your difficulties are really that great, IMHO sort them out first so that you can give your full attention to conversion. Mesila (http://www.mesila.org) empowers men, women and children across the Jewish community to seek, achieve and maintain economic self-sufficiency and stability. Maybe they can help.
Comment: Welcome to Mi Yodeya, Tami! It's always best to ask personal questions like this to a competent Rabbi, rather than relying on random Internet strangers. For that reason, the site policy is not to accept personalized questions. I wish you much luck in finding the answers you seek, but if you're looking for accurate ones you know you can rely on, this isn't the place to find them.
Comment: Is your last sentence asking if there is anything in Jewish Law that allows one to convert partway, or convert in multiple steps, as opposed to one full conversion?
Answer: You have asked a useful, practical question. My thoughts on this - much based from experience being a religious Jew as well as some experience of conversing with a close friend of eventually converted.
There is a general rule that we try to discourage people from converting. Religious Jewish life poses many challenges for Jews, and these challenges can seem even greater for a Gentile. I don't want to detail much how things are more expensive. However, I recommend that you consider the expense factor carefully before you decide to convert. The decision is not reversible. Ask a rabbi or a practicing religious Jew to detail the expenses among the other time commitments involved, if you want a better idea.
You mentioned - distance to shul, etc. Technically, of course, you can be Jewish without attending shul, ever. There are numerous Jews throughout the world who never attend shul or observe Shabbat. They are Jews "in name", in my opinion. Statistics show that their children have a high likelihood of intermarriage, and as a result of that, if it's a man marrying a Gentile woman, the Jewish continuity stops.
My point is, that continuous ritual is extremely important. It need not be everything, but it should, at least involve Shabbat / holiday observance and having a kosher home. Those two tend to be the "essentials" and insure continuity. Yes - they are expensive. Perhaps, you can get some assistance to manage these expenses. But, I strongly recommend that if you decide to convert, be prepared to fund and deal with these expenses for the remainder of your life and make them priority. If you have no means to do this - either yourself or via assistance / funding from someone, then I think conversion may not be the right route for you.
My friend converted about 30 years ago, when she was single. She didn't completely calculate how difficult it would be when she married about 10 years after she converted. She struggled but managed for many years. The community pitched in, frequently. She occasionally told me, "I wish I had known how expensive this was." In her case, I don't think it would have affected her decision. But the fact that she has said this several times, is some indication that knowing this beforehand would have helped her make a better educated decision.


If a flag turns out to be be useful, can the "disputed" status be updated?

Question: I flagged a post on Stack Overflow, but as it wasn't accepted,  I got a "disputed" in my flag stats. But to my surprise, the question was actually put on hold an hour later. No edits or anything different, just a different person checking the flags. My question is, can I get rid of that 'disputed' in my flag stats? As it was actually correct? And how?
Comment: This has happened much more times since I asked this question :/ We should have an automatic system that when a question is closed any previous flags change status.
Comment: for the "but the question was put on hold" part, see http://meta.stackexchange.com/questions/105391/why-does-flag-marking-as-helpful-declined-not-always-correlate-with-moderator-ac
Comment: A disputed flag will never change status. It means that someone disagreed with you. If I disagree with your flag, mine is born "disputed". Think of disputed as +0, with helpful +1 and declined -1. Do not get upset about disputed flags. As for declined, the work to automatically change them to helpful when questions get closed would be horrendous - and for what? Anyway, if you want that to happen, post a new question tagged feature-request - but be prepared to back it up and justify the programming effort.
Answer: tl;dr: no, other than spam and rude/abusive flags, a flag's status will never change once it is no longer "active".
Flag status types
There are six different flag statuses:

Active
Helpful
Declined
Disputed
Retracted
Aged away

Active
The flag has been raised, but not yet handled by a moderator, the community, or the system.
Helpful
Helpful means a mod specifically marked the flag as helpful, or the general action implied by the flag was taken by a mod, the community, or automatically by the system.
Declined
Declined, generally, means that a mod specifically declined the flag. In some cases, a flag can also be declined by actions by the community in the review queues.
Disputed
Disputed basically means neither happened.  Other than spam or rude/abusive flags, a mod never took specific action on the flag and likely never looked at the flag, but the action you suggested wasn't taken in response to the flag either.  This can happen in any number of cases; certain flags are marked disputed when the post is edited; non-moderator users can choose not to act on a flag (either through the 10k tools page (which has since been removed) or through certain review queues) which disputes a flag, etc.
For spam and rude/abusive flags, "disputed" means that a moderator specifically "cleared" all spam and rude/abusive flags on the post. When a moderator does this, the state of all spam and rude/abusive flags on the post is set to "disputed", regardless of the flag's prior status.
Retracted
The user who raised the flag has retracted it.
Aged away
The flag has expired due to the passage of time. This is most commonly seen for close or reopen flags. Some other types of flags used to be able to age away, but the system has been changed such that other types of flags no longer age away.
General information
Note that any flag as "In need of moderator intervention" will be seen by a moderator, and no actions taken by any user will ever automatically resolve the flag, as such "In need of moderator intervention" flags cannot be marked as "disputed".
While having declined flags is bad, having disputed flags is...less so.  They're certainly not something to be as concerned about, because it usually means someone wasn't specifically evaluating your flag, but rather performing some related action that rendered your flag "moot" in some way.
Declined flags will "count against you", but disputed flags won't; it's more like you never submitted them in the first place.
In generally I'd say don't be too too concerned.  By all means look through your flags periodically; if you see declined flags then a trusted site moderator specifically felt that your flag was wrong, so you should consider reforming something.  While a disputed flag might mean that you're not suggesting the proper action, it also might not.  By all means look into it, but if you can see that you did the right thing (i.e. the post was later closed/deleted) then you know you're fine and move on.
Flag statuses are primarily just a form of feedback to you.  So long as you know how to properly respond to similar instances in the future, everything is fine.  If you have a particularly huge percentage of declined flags then you may enter the field of "flag abuse", resulting in some sort of consequences, but you'll almost never unintentionally get there.  Beyond this feedback, the number isn't really used anywhere.
Comment: +1 for actually explaining what a "disputed" flag means; this is the first actually clear explanation I've seen of it.
Comment: @RichardTingle Ah, yes edited.
Comment: Note that the system only really looks at declined flags over the past 7 days (unless you flag < 10 times per week, at which point all you'll ever get is a warning for your most recent declined flag). See [Allow recovery from flag hellban](https://meta.stackexchange.com/q/173878)
Comment: @RichardTingle In the very last paragraph I really did mean declined, not disputed.  Mods tend to be a lot more concerned about flags that waste their time than on flags that get automatically resolved by the community.
Comment: This is happening to me a lot lately. In triage I flag a (low quality) question as unsalvageable, the other reviewers vote "should be improved", and my flag is disputed. A short time later the question is closed. I don't care about the status of the flag, but the review process is surely broken - those voting "should be improved" need to be hit with a review audit.
Comment: As it turned out in https://meta.stackoverflow.com/questions/361549/declined-too-broad-flag the sentence *"Declined means that a mod specifically declined the flag."* is not true and is confusing. Suffiecient number of reviewers will also cause the flag to be declined.


Does ZFS check integrity by swap too?

Question: I have ECC memory and I'd like to put swap on a filesystem, which does integrity checks. Will ZFS check integrity by reading the swap?
Answer: If the swap space is a ZVOL or a swapfile on a ZFS dataset then it will benefit from all of ZFS' features, just as any other file or ZVOL would.
If the swap space is a bare partition or a swapfile on another filesystem, then it won't.
Comment: dunno about "something special", but zfs devs wrote their code to make sure that swap works on zfs (BTW, early versions of zfsonlinux were prone to crashing if used for swap. works perfectly now).  btrfs devs didn't.
Comment: I read in the btrfs faq that btrfs does not support swap files and swap partitions. Is there something special about them which zfs managed to solve, but btrfs didn't?

Does ZFS check integrity by swap too?


What is the difference between aurorae and electroglow?

Question: One of the discoveries of Voyager 2 at Uranus was a phenomenon called "electroglow", which as I understand it is related to charged particles interacting with the atmosphere that cause the emission of ultraviolet radiation. What I am not clear on is how this process is different to the production of aurorae. Is there some clear difference between the two processes that allows them to be distinguished?
Answer: Aurorae are caused by charged particles (usually electrons) being drawn into the polar atmosphere by the planet's magnetic field.
Airglow is caused by just photons interacting with the atmosphere.
Electroglow requires both electrons and photons.
Source: The Free Library  (article is under express copyright, see the paragraph that starts "Voyager 2")
Comment: I understand that the copyright dissuade one from even a brief quote, that still makes this a link-only answer. Without going offsite, I still do not know what electroglow is nor why it requires both electrons and photons. You can certainly *paraphrase* what your source says without violating any copyright.


Moving a circuit from one panel too another

Question: I have 4 sub panels in my home and I want to move two 20amp breakers from one into another. I want to run #12 Romex from the one panel too the other and use the original panel and just splice each circuit. My question if the neutral stays in the original box can I just move the hot leg
Comment: So will 1 neutral for the two hot circuits (3 wire Romex) be ok... Or do I need to run two 12-2 Romex
Answer: You MUST move both the hot and neutral together!
The underlying principle is currents must be equal in each cable or conduit.  You can't have a situation where current flows on the hot wire from panel 4 to panel 2, but neutral just ends at panel 2 and takes a different route back to the panel (creating an imbalance in that cable too).
If currents are equal, each wire kicks a large electro-magnetic field (EMF), but the various wires are equal and opposite, so the magnetic fields cancel each other out.
Since currents are not equal, large electro-magnetic fields are kicked up. This will cause eddy current heating, and vibration -> fatigue failure on wires.
Further, neutrals do not have circuit breakers.  This is safe, because neutral only handles current for its partner hot wire(s), so they handle the same current and the "hot" breaker protects the neutral.  If you return current from a different path, you break that protection, and now the oversubscribed neutral can overload - and no breaker will care.
Answer: No you cannot just move the hot. You must move the hot with the neutral. The ground needs to come from the same panel if there is one. You can splice in the panel and jump to the original panel that would be ok.
Comment: I was going to use two wire Romex with the ground but the but if the nuetrsl is in both sub panels why would it matter
Comment: These are both sub panels .... When I say original I meant the panel it was originally in just to splice
Comment: This is a code requirement , additional connections can create problems.
Answer: NEC 303.3(B) Conductors of the Same Circuit All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors...shall be contained within the same raceway...cable..
The grounded circuit conductor is the neutral.
Comment: Ok thanks... So I should be able to use a three wire and would be good to go...


Perfect square or cube

Question: There is series like $N = 3! + 4! +\cdots+ 64!$. It is asked whether it is perfect square or cube .  How to identify Whether $N$ is perfect square or cube for any big factorial or for sum of factorial ?
Comment: It's not divisible by $4$.
Comment: @LordSharktheUnknown ...but it is divisible by $2$. Slick.
Answer: Let us define $a_n$ as
$$a_n=3!+4!+...+n!$$
Rearrange this sum as
$$a_n=3!(1+4+4\cdot 5+4\cdot 5\cdot 6+...+4\cdot5\cdot ...\cdot n)$$
Since $3!=6$ is not a perfect square or divisible by a perfect square, in order for $a_n$ to be a perfect square, the sum $1+4+4\cdot 5+...+4\cdot5\cdot ...\cdot n$ must be divisible by $6$. Note that all terms including and after the $4\cdot 5\cdot 6$ term are divisible by $6$, so the whole sum is divisible by $6$ if and only if $1+4+4\cdot 5$ is divisible by $6$. It is not divisible by $6$, so $a_n$ cannot be a perfect square.
Of course, this makes the assumption that $n\ge 6$, but you can check the cases $n=3,4,5$ for yourself since they are only finitely many.
Answer: the number is of form 8k+6. a perfect square cant be of this form.
Comment: This looks like a perfectly OK answer to me. It does not give all the details; so what? It is a very strong hint, like many other answers on this site.

Perfect square or cube


How to configure PUMA for SSL on JRUBY

Question: I have a jruby rails app that is working fine with Puma without SSL. According to Puma's wiki, I have to provide a certificate file and a key file. I got my cert file from GoDaddy and since I am on osx, I extracted the private key from the cert using the Keychain app. I am starting Puma using the following command:
<code>bundle exec puma -b 'ssl://0.0.0.0:3000?key=file://Users/me/key.p12&cert=file://Users/me/server.x.ca.crt' -t 3:8
</code>
After that I get a bunch of warnings about redefined SSL constants like this one
<code>/Users/me/.rvm/gems/jruby-1.7.1/gems/jruby-openssl-0.8.2/lib/shared/jruby-openssl.rb:16 warning: already initialized constant OPENSSL_VERSION_NUMBER
</code>
Then this message:

Puma 1.6.3 starting...
  * Min threads: 3, max threads: 8
  * Environment: development
  IOError: sun.net.ftp.FtpProtocolException: Welcome message:
      initialize at org/jruby/RubyFile.java:333
        open at org/jruby/RubyIO.java:1179
                open at org/jruby/RubyKernel.java:333
                read at org/jruby/RubyIO.java:3611
                read at org/jruby/RubyIO.java:3708
                 run at /Users/me/.rvm/gems/jruby-1.7.1/gems/puma-1.6.3-java/lib/puma/cli.rb:359
                each at org/jruby/RubyArray.java:1612
                 run at /Users/me/.rvm/gems/jruby-1.7.1/gems/puma-1.6.3-java/lib/puma/cli.rb:314
              (root) at /Users/me/.rvm/gems/jruby-1.7.1/gems/puma-1.6.3-java/bin/puma:10
                load at org/jruby/RubyKernel.java:1046
              (root) at /Users/me/.rvm/gems/jruby-1.7.1/bin/puma:1
                eval at org/jruby/RubyKernel.java:1066
              (root) at /Users/me/.rvm/gems/jruby-1.7.1/bin/ruby_noexec_wrapper:14

And Puma exits. The app runs on my dev machine. I am not using any FTP so I am puzzled by this error message. Any help would be greatly appreciated.
Answer: It seems that Puma 1.6.x on Jruby do not work with SSL (see the last Evan Phoenix's comment at the bottom of the page). I now use Apache as a reverse proxy to handle SSL in front of Puma.

How to configure PUMA for SSL on JRUBY


Why does my pictures becomes darker while using external flash ?

Question: Camera is Canon EOS 250d
Flash is YN565EXIII
Whenever i use this external flash with my camera the image becomes darker
I am newbie in this photography world so all the thing is set in default
Just incase if required ( mistakenly i rolled the slider unknowingly which is near the eye lens or eye view )
I dont know how to fix it or we need to change some setting for that pleaee help me
Comment: The slider near the eyepiece is probably the diopter slider. Adjust it for your eyesight.
Comment: What exposure mode (M, Av, Tv, P) are you using? What shutter speed, aperture and ISO are you using? Can you post an example picture? I would recommend going for M if using flash photography to determine the exposure for background manually, and then either using E-TTL II automatic flash or adjusting even the flash manually, too. Please note the flash can only light up a foreground, not the background, if the background is far away.
Comment: Does the flash fire at all?
Answer: The Canon EOS Rebel SL3/250D does not have an ISO compliant hot shoe. It's missing the center pin needed to trigger "manual only" flashes. Canon recently started doing this with their lower end entry level cameras.
The Yongnuo YN565EX III is Canon E-TTL capable. But it may not be able to cope with a Canon camera that has the center pin missing on the hot shoe. Many third party E-TTL capable flashes and triggers require a firmware update to work with the Rebel SL3/250D, Rebel T7/1500D/2000D, and Rebel T100/300D/4000D.
Comment: Oh, I didn't realize the likely problem was that the flash was not firing at all! I thought if the flash didn't fire, it should have been explicitly mentioned.
Comment: @juhist Maybe not. The YN565EX III is supposed to be E-TTL compatible, assuming he's got the Canon version. Updating answer.
Answer: The YN-565EX III requires a firmware update to be compatible with the hotshoe of the 250D/SL3, and to fire when the camera tells it to.  Newer entry-level Canon dSLR bodies have had the sync contact removed from the hotshoe, which can create incompatibility issues with non-Canon speedlights.


Site.com: Prevent Sub-Menu navigation disappearing after selection

Question: Just noticed that when selecting a sub-menu item from main navigation and you are directed to that page, the current page you are on is no longer visible in the main menu navigation.  Don't know if this is by design or not and I can't find anything that would prevent this from happening and the users are not wanting this menu item to disappear, so thought I would put the question out here to determine if it is something that is configurable or not.
Answer: When you navigate to a page that is a sub-menu item in the menu control, that page could disappear from the menu if the menu is configured that way.   There are different types of menus that you can create as documented in the help.

By default, when you create a menu, it's generated from the pages and site map links in the Site Map folder in the Site Pages view. However, you can also create a menu that's generated from the pages in the Landing Pages folder or from the child or sibling pages of a site page.

So, if the menu source is set to Child Pages, the menu only shows pages that are children of the current page.  When you navigate to a page it will no longer show up in the menu.
Also, if the menu source is set to Landing Pages, the menu only shows pages in the Landing Pages folder, so if the current page is not in the Landing Pages folder it would not show up.