Stretching out arms in prayer?

Question: There was a deleted question earlier this week asking about the parameters of spreading out one's hands in prayer, something which was very common in Tanach as part of prayer (e.g., Shemos 9:33). When is this permitted/recommended, if ever? What would be the rationale for limiting it?
Comment: R. Aqiva Eiger on SA OH 89:1

מה שאין אנו מתפללים בפרישת כפים כמו שמצינו במקרא כמה פעמים ובזוה"ק ובפרקי דר"א היינו כיון דעכשיו האומות עושים כן. וכמו שאמרו חז"ל על פסוק לא תקים לך מצבה באר שבע סי' ע"ד
Comment: @Deuteronomy shkoyach! Does that apply specifically to shemoneh esrei, or any circumstances?
Comment: No problem. I assume that according to his position this would be universally applicable. I also came across the introduction to R. Yaaqov Emden's siddur, section 3 subsection 5 (it is on the bottom left of page 12b of the 1904 Lemberg edition). He has a much more involved discussion of the matter beyond what I could report with any justice here. Definitely worth a look inside if you are researching this topic.
Comment: Separately it is worth noting that in certain Sepharadi communities, many open/outstretch their hands while reciting the line פותח את ידך. The propriety of the custom is discussed here: http://halachayomit.co.il/he/Default.aspx?HalachaID=1134 and interestingly it reports that R. Eliezer Y. Waldenberg adopted this custom despite not receiving it ancestrally.
Comment: This may or may not be what you want, but see the mishna berura (105:5) who says that A) people who look up towards the ceiling during tefillah are made fun of by the angels (i'm bringing this because it's lechorah common practice among people who spread their hands out, but maybe not, do whatever you want with this information), and also B) that it's not right to shuckle in an unusual way, maybe this would be included, maybe not, you be the judge. I would also add that the mechaber says outright in sif 3 that a person should ideally daven with his hand over his heart.
Answer: I haven't learned through it yet, but just today I came across a פחד יצחק פורים סימן לה who discusses this Rav Akiva Eiger, presumably from a השקפה angle. It is not available on HebrewBooks but at the moment it can be read for free at https://beta.otzar.org/#/b/147108/p/81/t/16440.4141604144245259/fs/0/start/0/end/0/c/1646162172337
Answer: See Shlomo Hamelech's prayer, that Hashem should answer non-Jews who spread their hands and come all the way to the Beis Hamikdash.
Implying that Jews don't need neither this nor that, we don't need to raise our hands (perhaps in a sort of desperate despair) nor even wait till we get to a holy site - G-d will answer us everywhere we are.
I have seen people raise their hands in prayer and I have never heard that it is wrong, but it is the quiet confidence of Shevach - Bakasha - Hoda'ah that is the usual signature of Jewish prayer.

Stretching out arms in prayer?


When a Shopify store customer has logged in to his account on the store I want also make him log into my Shopify app

Question: I have developed a Shopify app, I wonder if we can perform the following functionality :
when a customer has logged in to his account on the store I want to also log him into my app, in another word I want to make a customer account is the same as his account on my app.
Answer: One thing you know. A customer logged into a Shopify store has a visible ID to Javascript. You could thus use an App Proxy to securely pass back their ID to your App. Using that ID, you can offer functionality to that customer, in your App. As long as you restrict access to the Proxy, you'd be A-Ok security wise.
If you wanted to allow access to the App without Proxy calls, you'll have to put into place your own security, which as we know from experience, will likely be weak and or a calamity. Most people should never roll their own security patterns. If they login to the App, without Shopify Plus Multipass, you cannot log them into Shopify. So you have no other options AFAIK.


Are quran verses interpreted apologetically or objectively

Question: I had apostated a while ago because I was ignorant on matters of islam in terms of actual proof that is comes from Allah, so I searched the internet a lot to find proof, and after a long time I cam across hamza tzortis videos and relearned about something called Isnad, and then saw it as strong proof to believe, so now I want to convert back to islam and become muslim, but there are some problems that prevented me form believing even through these proofs. An ignorant female,meanings not qualified to talk about islam the way she does, said that the quran has errors and contradictions, so I told them a very simple thing which is you cant use a seemingly contradictory verse as evidence against islam if you realize that there is a need to interpret verses, very simple. But she just said "or admit its flawed" and I said fro what, if interpretation is necessary then why immediately call the quran flawed and then insult it due to your opinion, she even admitted herself that 'you don't need a scholar to understand islam, you can form your own opinion" why are you insulting islam based off of opinion instead of a verifiable fact? But my problem is in wondering how scholars interpret verses,do they interpret it apologetically, to make sure that it is interpreted in a way that makes it seem free of error or contradiction, o is there an objective way, to interpret the verses, this is what caused me doubt. The quran shows that verses aren't to be interpreted based off of your desires, meaning that there is an objective way to interpret it, but does that apply to all verses , as the quran says some verses meanings are known only to Allah. For example, the female brought up the food of hell as a contradiction, first it said they only eat foul pus, and then it says they only eat dhari and then only zaqqum. Dhari is part of zaqqum, so does that mean that foul pus comes from dhari? SO the question is this: is the quran cleared of contradictions with biased or unbiased interpretations? Now I understand that there will of course be some apologetic interpreters, but the question I have is is purposefully apologetically interpreting verses common amongst most interpreters? Interpreting apologetically can mean things like making sure it aligns with science as well.
Answer: Great Question, Insha'Allah in the permission of Allah the almighty, I shall try to answer your question.
Most of the time they interpret it objectively. The scholars do not make the evidence up in their head.
They use sources such as:
Quran - Sunnah - Narrations from the Sahabah [Not raised to the prophet] - Narrations of the Students of the sahabah - Narrations of the students of the students of the sahabah.
They do not make the answers up in their own head. They mastered the arabic grammar, and can connect verses to the hadiths that we have. The fact that we interpret the Quran does not make it flawed because we use those who have relations to our beloved prophet muhammed (Peace and blessings be upon him and his family). A great example/evidence that the scholars do not make stuff in their minds is to literally read their interpretations. If you can only read english then read Ibn Katheer's interpretations. Though, a verse in which makes it evident for us that the scholars of knowledge do not make stuff up is Surat Al-Baqarah Verse 1, "Alif Lam Meem". The scholars do not know what it means, and why you might ask? Because there is no evidence backing up anything they could state. So, scholars decided that Allah the almighty and all merciful is showing that he is higher above us. No matter how hard you look you will never find the true meaning without their lord the Almighty. This is what they concluded. Of course, there are many theories, but if anyone were to state something about it that has no evidence they will always state that it is a theory unless they are a layman with no knowledge stating it.
Now allow me to state the ways they can gain  the interpretation of a verse. Though, before doing so, remember the sources we stated earlier? I'll give you an example on how.
For instance, let us say there is a verse in the Quran which states. "Those who disbelieved and will disbelief Allah blinds in the day of judgement". Now, the sentence is not as beautiful as a single verse in the Holy Quran. Though, lets continue. Now lets also say there is a hadith that reaches the prophet which talks about this.
Narrated Me Narrated Ibn Taymiyyah Narrated Ibn Abbas Narrated ibn AbdulWahab Narrated Al-Razi He said: "I heard the prophet (Peace and blessings be upon him and his family) saying: Allah the almighty knows who will disbelief and who has disbelieved, and when or if they have they will be put a blindfold of lava on them in the day of judgement"
Grading: Saheeh (Its not if you know the scholars I put [May Allah be pleased with them])
So, the scholars would connect this hadith to the verse (which is made up), because it is quite similar to the statement.
What about the words of the Sahabah?
Narrated V Narrated W, he said, X informed me, from Y, He said, "The meaning of the verse (we made up) it is connected to the statement of our beloved prophet Muhammed [Peace and blessings be upon him and his family), that lava will be put on the eyes of those who will disbelief and those who will in the day of judgement".
Grade: Saheeh [Graded by Z]
Now, this is a narration (we made up) from a well known companion of the prophet. We would also connect this in the hadith. Also, another example.
Not a narration:
"According to At-Tabari, the verse is speaking of those who will and have disbelieved in Allah, and they will be put lava on their eyes in the day of judgment [At-Tabari 4/200]"
This is an example of quoting from other books of the scholars of interpretation. One of the well known ones for example At-Tabari and is one of my person favorite. May Allah have mercy on his soul and bless him and be pleased with him.
Of course, they also use their arabic grammar skills to understand the verse, but I cannot explain this to you because it is hard to do so.
Insha'Allah, In the permission of Allah you will either understand the statements I've said and understand how reliable the interpretations are. The scholars do not make stuff up, and alhamdullilah for islam. This is a very powerful way of interpreting the Quran. May Allah guide you, and those around you.


Plot NaNs as a category seaborn countplot

Question: I have a column in my dataframe which has 'True' as a value and all other values are NaNs (so there are no 'false' values). I want to plot a countplot for the said data in seaborn but want to include the NaNs as well. Basically, I want to convert the NaNs to 'false' values and plot a graph then but I dont want to make any changes to my original column. Is there a way I can create a separate category for NaNs as False category and plot it alongside the True category?
Comment: You would like to replace nan values with False value as boolean in one column, but this update will be on a new dataframe, not the original one, is that your question?
Answer: Yes, you can make a copy of  your dataframe to a new dataframe and then apply the conversion from NaN to false as follows:
df2 = df.copy()
df2['column']  = df2['column'].fillna(False)


Disable Growl Notification When a Certain App is Running

Question: Is there a way to disable Growl notifications automatically when a certain app is running, Quick Time for example. I don't want to get the notifications while watching a movie.
Comment: It looks like this has already been answered over at Super User: http://superuser.com/questions/143703/is-it-possible-to-somehow-hide-growl-and-herald-when-vlc-runs-fullscreen
Answer: Full credit to @ghoppe over at Super User for this excellent answer.  I'm only duplicating it here because a moderator on Meta suggested that it would be appropriate to do so.
Please note that this solution will suppress Growl when VLC (media player) is running.  To make it work for another application (e.g. QuickTime), you'll have to modify the Applescript.  If you've tried yourself but still need help, I would suggest posting a question about it over at Stack Overflow.
Original answer follows:

Enter in Applescript Editor, save as application, when saving check the box "Stay Open". Use this new applescript application to launch the VLC application.
Description: It will launch VLC, turn off growl notifications, check every 2s to see if VLC has quit, if so it will turn growl notifications back on and then quit. As a bonus, it will use growl notifications to notify you when growl notifications will be turned on or off.

<code>global Growl_was_Loaded
global VLC_is_Loaded

on run
    set Growl_was_Loaded to isAppLoaded("GrowlHelperApp")
    set VLC_is_Loaded to isAppLoaded("VLC")
    launchVLC()
    idle
end run

on idle
    set x to isAppLoaded("VLC")
    if x and not VLC_is_Loaded then
        launchVLC()
    else if VLC_is_Loaded and not x then
        set VLC_is_Loaded to false
        if Growl_was_Loaded then
            tell application "GrowlHelperApp" to launch
            growl_notify("Growl notifications have been turned ON")
        end if
        tell me to quit
    end if
    return 2 -- wait 2 seconds
end idle

on launchVLC()
    tell application "VLC" to launch
    if Growl_was_Loaded then
        growl_notify("Launching VLC… Growl notifications have been turned OFF")
        delay 1
        tell application "GrowlHelperApp" to quit
    end if
    set VLC_is_Loaded to true
end launchVLC

on isAppLoaded(app_name)
    tell application "System Events"
        set app_list to every application process whose name is app_name
        if the (count of app_list) > 0 then
            set x to true
        else
            set x to false
        end if
    end tell
    return x
end isAppLoaded

on growl_notify(msg)
    tell application "GrowlHelperApp"
        set the allNotificationsList to {"Growl Toggler"}
        register as application "Growl Toggler" all notifications allNotificationsList default notifications allNotificationsList
        notify with name "Growl Toggler" title msg description "" application name "Growl Toggler" icon of application "Automator"
    end tell
end growl_notify
</code>
Comment: Made it a community wiki so I don't get credit for someone else's answer.  If you like it, please also vote up the original question over at Super User (linked in the answer above).
Comment: Thanks! I'll try to edit the script to work with other apps. I'll post the result.


Automatic tranny, reverse died during cold snap

Question: The vehicle is a 2005 Chevy Classic 2.2L four cylinder. It starts and runs, or ran and drove, fine down to -15-20° F up until recently. With a few days of -30 and -40 temps, the car, even after 30-45 minute warm ups, tended to shift balkily at times, for a couple of days skipping 2nd and shifting only after the car was moving close to 40 mph. So I drove it quite carefully. Then suddenly, after running and driving for over an hour on a sub -40 day, I lost reverse. I thought it might come back when it warmed up, but now, even at 0° F, there is no reverse. The engine will rev in either Park or Neutral, but the engine has a load when in reverse. The car just doesn't move. Thoughts?
Comment: Welcome to Motor Vehicle Maintenance & Repair! Sounds like your transmission has given up the ghost. Usually if you put it in reverse, the engine gets a load, and the vehicle goes nowhere, I'd think both reverse and drive are engaged, which means the gears would be cancelling themselves out. If it were a racing transmission, it would be like a transbrake. Anyway, in your situation I'd think you're going to need some serious medical attention for your vehicle ... This is just a gut check and not an answer, so leaving it as a comment.
Comment: Also, is this a Malibu Classic?
Comment: Have you tried changing transmission fluid?  Can't hurt, might help. Look for discolors, bad smells, particles.
Comment: It is a Classic. It seems like a Malibu Classic though that nomenclature seems to confuse some of the parts chasers so I just use Classic along with the VIN when seeking help.. But it is a sedan, not a truck.
Comment: I know it probably needs to be seen by the Mayo version of transmission help, but I was wondering if perhaps these symptoms were consistent with a simple external issue I could try before hand.
Answer: i can't commenting for gut answer,
but here is my guts answering:

your disc is break / damaged.
your solenoid jammed

solution for 1:
try to drain your transmission fluid, if dropping some dirt like brittle and like small hard piece than it might be true, your reverse disc broken, it maybe you need to change whole disc since some dealer only selling a whole pack and avoiding future break.
solution for 2:
check voltage across your trans shift, it should have voltage going to reverse solenoid. dit could be just the shift knob is broken (cheaper)
if the voltage is good, than you should check the solenoid in your transmission, check whole solenoid try to jumper with 12V directly (this should be only be done by professional mechanic) if it still works than it could be your worst nightmare on whole transmission.


Rolling back a file

Question: I have a situation, a colleage of mine overwrote PHP files that I've made changes to , is it possible to roll back a file to a previous working version using the command line. No svn repositories are available and also not any backups.
Answer: I'm sorry to say that if you didn't make any backups, you're almost certainly SOL here, especially from the command line.
Unlinking (deleting) a file can sometimes leave the data recoverable as long as nothing else grabs that particular inode; editing a file overwrites the data.
If your colleague still has the editor he was working in open and its undo buffer is long enough, that might be a way to recover the original, but beyond that I'm afraid you're sunk. Sorry.
Comment: Thanx for the response, busy setting up a SVN repository, just thought maybe maybe there's a chance of getting it back
Comment: I usually just tarball my work and delete that tarball every once in a while. But I'd seriously consider `git`, `hg`, of `svn` to backup your code. You can even schedule it to commit every few hours with `cron` if you have to.
Comment: @Roland Consider using `git`, after some learning it's so easy to use and so fast, so you'll never think about not versioning anything (and you'll not understand how you ever could use `svn`). I need less than one minute to create a repo for a new project, to commit, and to clone to a server. Just my opinion, not gonna start a flame war.
Answer: Assuming you're using ext3, it might be possible to recover it if the replacement file was created as another inode (instead of overwriting the existing file), by using debugfs on the unmounted filesystem, and to find the inode of the original file.  Unfortunately, if your colleage overwrite the file, rather than moving it aside and then deleting it, it's gone.  I would suggest using debugfs with extreme caution, because you can seriously mess up a filesystem.  It's use is only really for a last-ditch effort.
Comment: @thanks, no unfortunately it wasn't created as a inode, thanks for the response.
Answer: Usually you would have a tmp file created which begin with ~filename.extension. You can recover from that.

Rolling back a file


How to remove Nikon strap rings with plastic covers?

Question: I want to remove the strap rings on my Nikon D7000. They look to be pretty standard triangular split rings, but they also have a little plastic cover on them. How do I safely remove the cover in such a way that I can put the ring and the cover back on later if so desired? After some examination, it looks like I could just pry it off, but it would be nice to know if anybody's has experience with this before, so I don't screw it up.
Comment: Here are some interesting on how other have done it. http://www.fredmiranda.com/forum/topic/933078/0&year=2010#8810526
Answer: I have done this on my D800, I assume they are exactly the same.
So first remove the plastic clips, just push them HARD towards the on-camera mounting post, they should just pop off.
Then remove the triangular rings, they are VERY stuff so you may need a flat-head screwdriver to pry the end open, just rotate them around like a key-ring and off they come.
I NEVER use a strap, and these are very annoying jiggling about all the time...
Comment: I ended up going with a strap that uses the split rings, so I'm no longer trying to wrestle them off, but thanks for the info!
Comment: I didn't like the OpTech strap I got, so I switched to a BlackRapid. Once again, I didn't need the strap rings, so I pushed down on the plastic clip and it came right off. Thank you!
Answer: If "push them HARD towards the on-camera mounting post" reads like alien language to you, here's a Youtube video showing how to remove the rings.
https://www.youtube.com/watch?v=5lRqfZU7Gzg


How can I know the intervals of increase and decrease of a function?

Question: I mean, how can I know the intervals of increase and decrease of a composite function without seeing the graphic and just having the functions that form the composite function? Because I have some problems when both of the functions are piecewise functions.
Answer: Functions are increasing when the first derivative is positive and decreasing when their first derivative is negative.


Are atoms getting weaker?

Question: If the universe is expanding, it would make sense that the spaces between particles are getting bigger. If this is so, then the particles which make up atoms are also affected. Does that imply the spaces between the components of an atom will become large for the subatomic forces to hold? Are atoms getting weaker?
Answer: Any effect of the expansion of the universe on atoms is beyond all experimental hope. While spacetime should affect the movement of atoms (the metric is right there in all the equations), due to the constants involved, the effect is around the Planck scale, and the expansion itself is already pretty low in intensity. Hence any effect would require a long time before being observable. Just by being in the same room, you affect atoms around you more than the expansion of the universe.
Though that does not means this was always the case or always will be. The very early universe had a very strong gravitational field, and the Big Rip is a scenario where the expansion grows at such a rate that it will eventually affects all scales.
Comment: The argument that any effect would be of the order of the Planck scale seems flawed, since for the expansion of the universe the relevant quantity is the Hubble time, which isn't equal to one in natural units.
Comment: True, but the important quantity here is the metric tensor (or tetrad for the Dirac equation), where the scale factor is, if I recall, a function of G among other things. Plugged in the Dirac equation, you will get something which I think will depend on the Planck length for the perturbative term (can't check now as I am in the bus)
Comment: For sure the Planck length will turn up in your calculation; my point is that any correction coming from from the expansion of the universe should actually depend on the rate of expansion (and maybe some other cosmological data).
Answer: To understand the numbers, here are the four forces we know affecting all matter:

Look at the strenght of each interaction.
The quantum mechanical equations that define the nucleons/atoms/molecules/solid/liquid/gas phases incorporate in their potentials the strength shown in the column above. The strength of the gravitational force is so small that it will not affect the solutions within the possibility of measurement. The binding forces are very much stronger .Any diminution of the gravitational strength due to the expansion of the underlying fabric is unmeasurable because  the expansion is even weaker than gravity, even galaxies retain their form:
When we go within galaxies they do not measurably expand, one has to compare the expansion rate with the strength of the gravitational interaction. Again expansion looses because in these huge masses gravitational attraction, even though very weak at the atomic scale, is much stronger than the expansion of the underlying space, within our possibilities of measurement. Expansion is seen in the motions of clusters of galaxies.
Answer: The expansion of the universe is about galaxies moving away from each other. There is no general increase of distance between stars within any one galaxy.  There is nothing at all going on at even smaller scales, so far as cosmic expansion.  That is the standard way of thinking in physics.
If atoms did change over time in a way related to cosmic expansion, we'd have trouble with defining units of time and distance.  For the last couple decades, the second is defined certain vibrations of pure Cesium 133, and the fundamental space-time constant, speed of light, is a stated fixed number. If atoms did something odd like slow down slightly over millions of years - how would we know?  So any effort to uncover novel new phenomena normally concentrate on pure numbers (without units) such as electron/proton mass ratio and the fine structure constant.
This gradual change is pure theoretical speculation.  So far, unless I missed something, there's very little published experimental work on observing any such phenomena. (I didn't say 'none', but 'very little'...)
Answer: Everything in the universe tend to be more stable. Stability can either be attained by having maximum randomness or having less energy. Both the factors are independent in nature, the one with more influence predominates. In case of atoms, electrons in the atoms have less energy at lower orbits, the electrons in higher shell have more energy. Thus, electrons will be stable with it, without getting more randomness (entropy). Thus, you might not find increase in distance between the atomic components. So, atoms will not get weaker.

Are atoms getting weaker?


What is CLR hosting?

Question: What is CLR hosting? What is the use case for that?
Answer: See here for information about CLR hosting that was relevant for CLR v2 (.NET 2.0, 3.0 and 3.5). For information about the newer CLR Hosting API in .NET 4.0, see here.
Basically, the CLR acts as a library that can be loaded and "hosted" by a process. You can develop an app that loads and hosts the CLR if you wish; that would allow your app to contain a whole CLR virtual machine, load assemblies and run .NET managed code all within it.
SQL Server 2008, for example, can do this. You can write .NET code that is stored in a SQL Server database and run from within the SQL Server database engine. SQL Server is hosting the CLR to achieve that.
A CLR host other than the Windows shell (the usual user interface) can provide a specific context for your code to run. This can be useful for specialised applications or very particular scenarios. MSDN (link above) has some guidelines on these matters.
Comment: +1 Thanks for the answer.  Also: when a .NET executable is double-clicked and launched, who hosts the CLR? Is it hosted by Windows Explorer?
Comment: Well, "Windows shell" is a well known phrase to refer to the user interface components of the Windows OS from the development perspective. Please see here: http://msdn.microsoft.com/en-us/library/windows/desktop/bb773177(v=vs.85).aspx It is also the phrase used by .NET CLR documentation to discuss hosting alternatives.
Comment: @Sabuncu: Yes. That is the Windows shell I was mentioning in my answer.
Comment: Thanks.  I saw your "Windows shell" reference, but wasn't sure. In this case, I think you are using "shell" in the generic sense, not a shell program such as the DOS cmd.exe or the PowerShell console.
Answer: CLR Hosting is Hosting the .NET Common Language Runtime in a process of your choice.
The use case would be situations where existing environments don't suit your requirements. Some of the existing environments are ASP.NET, WinForms, Windows Workflow Foundation, etc. If these don't suit your requirements, you can host it yourself.
Answer: CLR Hosting is Hosting uses .NEt application.When you start the .NET runtime inside a native process, that native application becomes a host for the runtime. This lets you add .NET capabilities to your native applications.
If  the runtime is running, but it hasn't got any loaded user code yet. Some internal thread scheduler and garbage collector are surely running, because they are part of the CLR runtime
It is very complicated than other hosting services.

What is CLR hosting?


How can I search for bolded text?

Question: My reasons for doing so are exactly like https://unix.stackexchange.com/questions/271550/how-can-i-search-for-bolded-or-underlined-text , but the accepted solution there is to use vim. I don't fancy that, especially when we can use man directly in emacs.
Answer: You can filter the interesting isearch-matches by the function registered at the variable isearch-filter-predicate.
I demonstrate this below in a simplified way.

I only check the first letter of the match. I accept the match if that letter is bold.
Apparently face-attribute interferes with isearch in Emacs 26.2. For that reason I introduced the variable isearch-face-bold-p-fun and set it to the more general predicate function isearch-face-p which just checks whether there is any face at the beginning of the match. Searching man-pages with that default works quite well.

(defun isearch-face-p (start end)
  "Return faces at START, preferring those named in buffer text there."
  (save-excursion
    (goto-char start)
    (face-at-point nil t)))

(defun isearch-face-bold-p (start end)
  "Return a bold face at START."
  (save-excursion
    (goto-char start)
    (cl-some (lambda (face) (and (facep face) (face-bold-p face nil t))) (face-at-point nil t))))

(defvar isearch-face-bold-p-fun #'isearch-face-p
  "Isearch filter for bold text.
The value should be a function suitable for `isearch-filter-predicate'.")

(defun isearch-bold-forward-end-fun ()
  "Uninstall isearch filter `isearch-face-bold-p-fun'."
  (remove-function (local 'isearch-filter-predicate) isearch-face-bold-p-fun)
  (remove-hook 'isearch-mode-end-hook #'isearch-bold-forward-end-fun))

(defun isearch-bold-forward ()
  "Like `isearch-forward' only accepting bold matches."
  (interactive)
  (add-function :after-while (local 'isearch-filter-predicate) isearch-face-bold-p-fun)
  (add-hook 'isearch-mode-end-hook #'isearch-bold-forward-end-fun)
  (call-interactively #'isearch-forward))

Tested with emacs -Q Emacs version GNU Emacs 26.2 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.30) of 2019-04-12.
EDIT: Adapt Drew's proposal to use INHERIT arg t for face-bold-p.
Comment: See my answer at https://emacs.stackexchange.com/q/51651/2370, for why your `isearch-face-bold-p` fails on a `man` page.
Answer: Another answer: Using @Tobias's isearch-face-bold-p, but corrected per this answer to this:
(defun isearch-face-bold-p (start end)
  "Return non-nil if face at START is bold."
  (save-excursion
    (goto-char start)
    (cl-some (lambda (face) (and face (face-bold-p face nil t))) (face-at-point nil t))))

You can do what you want using just C-z & isearch-face-bold-p while searching.  That is, you can add predicate isearch-face-bold-p on the fly. All you need is the filter predicate.  You can also save the resulting behavior, by using C-z n followed by the search-command name you want, e.g. isearch-bold-forward.
IOW, you can get the same behavior, including defining the search command, just by doing C-z isearch-face-bold-p C-z n isearch-bold-forward.  (From then on you can just use that new command.)
For this on-the-fly Isearch filtering you need Isearch+. See Dynamic Isearch Filtering.
Comment: Hi Drew. Ha ha ha. That `THING` arg of `face-at-point` is really funny! Generate a `*test*` buffer with `C-x b`, put the word `bold` in, place point in front of `b` and debug `M-:` `(face-at-point 'THING)`. I have already replaced `(face-at-point t t)` with `(face-at-point nil t)` in my answer.
Comment: Thanks for the tip with `INHERIT` for `face-bold-p`!
Comment: @Tobias: I thought that's what you wanted: to preferentially pick up a face name from the buffer text. But since you don't, I've changed my answer to use the same thing, nil.

How can I search for bolded text?


Cannot open RAW NEF files taken with my Nikon 5100 in Photoshop Elements 5

Question: I get a message saying that it is the wrong type of file.  Any bit of advice?
Answer: The Nikon D5100 did not exist when Elements 5 was released in 2006. Your D5100 was  introduced five years later in 2011.
To open RAW files from your D5100 you will have to update to a more current version of Photoshop Elements. The earliest version of Adobe camera RAW (what PSE uses to process RAW files) that supports the D5100 is ACR ver. 6.4.1. The first version of Adobe Photoshop Elements that supports ACR 6.4.1 is Elements 9.
You could also open the RAW .nef files from your Nikon D5100 in the software that came with your camera, ViewNX 2, make basic adjustments such as exposure and white balance, and then export them in a format such as JPEG that PS Elements 5 can open.
Comment: Adobe DNG converter would be another alternative. As long as elements works with DNG which I haven't verified.
Comment: The DNG converter uses ACR to read RAW files. When a file is converted to .dng, the RAW data within the DNG is still in the same format it came off the sensor, it is just in a different container. You still need the demosaicing algorithms for each specific sensor to open a DNG file from a camera with that specific sensor. The earliest version of ACR that can read a DNG file produced from a D5100 .nef is ACR 6.4.1. The earliest version of PSE that can use ACR 6.4.1 is PSE 9.


Allow DHCP clients to use public DNS server when domain server is down

Question: I have a small network with a Win SBS 2k3 (SP1) domain... how do I set it up so that the workstations (they're all DHCP clients) can still resolve domain names if the domain server is down (without messing up any Windows domain stuff)?
Comment: The short answer: You shouldn't.
Comment: Add a backup domain controller.
Answer: You can supply multiple DNS entries in DHCP.  You could provide the public DNS in that list.
BUT, i don't think this will work as well as you might think.  The correct way to do this is to have a backup DNS server for your LAN.
The reason it may not work properly is that even when your SBS DNS is running, clients may get a errors resolving hostnames for local machines because they queried an external DNS.
I found this trouble at my ex workplace.  Why it didn't work for me is because the local DNS name was the same as the external DNS domain name.  So, sometimes we get results and sometimes not.  I originally didn't set this up but discovered it.  Once I removed the extra entry and put in a backup DNS, I had things working better.  The other problem I had, although not entirely sure it was related was queries seemed to take a long time.
I'm not really sure if MS windows issues DNS queries in parallel or in sequence to each server.  If it's in sequence and the primary DNS is down you might get a long timeout.
So I think it could work, but it's far better to use a backup DNS. (EDIT: That is, a Microsoft Backup DNS server, not just any server!. This doesn't need to be a powerful machine.  It can be dedicated to just backing up DNS).
I'm not saying, don't try it, just don't expect smooth sailing with this method.
Comment: An AD member should NEVER have a non-AD DNS server configured.
Comment: @GraemeDonaldson That might need to be phrased better - they shouldn't have a DNS server configured that doesn't have the AD information, but serving AD DNS info from a non-Microsoft DNS server works just fine.
Comment: LDAP, Kerberos, DNS, and locating things through ordinary `SRV` resource records is not what most people who know their apples would call "their own way of doing things".
Comment: Ya, that's what I meant.
Comment: I **am** saying don't try it.  It's wrong.
Comment: @Graeme - that's true, because Microsoft have invented their own way of doing things.  He really should configured a Microsoft backup DNS.
Answer: You cannot.
I'll do the short answer, then, joeqwerty.  ☺
If the domain controller is down, and the domain controller is also acting as the DNS server for the LAN, then there's no other way to do DNS lookups without "messing up the Windows domain stuff".  The "Windows domain stuff" is heavily reliant upon the DNS.  Have multiple domain controllers, all with the DNS server rôle and AD-integrated zones, if the server going down is a major concern.
Don't use the proxy DNS servers that your ISP provides as "backups".  It's both wrong in principle and broken in practice.  For starters, the list of DNS servers that a workstation is configured with is not a priority ordered list.  Workstations can choose to query proxy DNS servers in various orders, subject to whim and a range of DNS client library bugs.
Further reading

Jonathan de Boyne Pollard (2003). Your fallback proxy DNS servers must provide the same view of the DNS namespace as your principal one.. Frequently Given Answers.
Answer: This has caused issues for the network I support -- using a public DNS. I didn't have direct control over those DNS servers and occasionally the domain clients wouldn't resolve the domain name right. As a result, I would get group policy errors (because it would randomly use the public DNS).
It sounds better to set up the AD DNS to do forwarding to the public DNS and have domain clients only use AD DNS servers (or servers properly configured for it)


Maxwell's Theory Of Wave Propagation

Question: What is Maxwell's theory of Wave propagation and what is its physical interpretation?
Comment: Have you tried using the Internet?
Comment: More specifically, as well as my answer, try searching for "displacement current". There is also a good section on the Wiki page for ["Ampère's Circuital Law"](http://en.wikipedia.org/wiki/Amp%C3%A8re%27s_circuital_law). To the close voters: in all fairness, it sure helps to know a little history to know exactly what to search here and to find out what it was exactly that Maxwell did: the four Maxwell equations are a far cry from his work alone.
Comment: I answered a similar question here http://physics.stackexchange.com/q/95912/
Answer: Before Maxwell, the known laws of electromagnetism were thought to be:
$$\begin{array}{ll}
\nabla \cdot \vec{D} = \rho& \text{Gauss's Law for Electricty}\\
\nabla \cdot \vec{B} = 0& \text{Gauss's Law for Magnetism}\\
\nabla \wedge \vec{E} = -\partial_t \vec{B}& \text{Faraday's Law}\\
\nabla \wedge \vec{H} = \vec{J}& \text{Amp}\grave{\text{e}}\text{re's Law}\\
\end{array}\tag{1}$$
where $\vec{E},\,\vec{H},\,\vec{D},\,\vec{B}$ are the electric and magnetic field, electric displacement and magnetic induction, respectively and $\rho,\,\vec{J}$ the electric charge and current density vectors, respectively.
The great problem was that Ampère's law as it stood was inconsistent with the principle of conservation of charge. If you take the vector divergence of both sides of the before-Maxwell Ampère law, you get $\nabla\cdot\vec{J} = 0$, whereas the general statement of charge conservation is $\nabla\cdot\vec{J} = -\partial_t \rho$. The latter form expresses the fact, for example, that charges can build up on capacitor plates as long as the nett charge of the system doesn't change, whereas $\nabla\cdot\vec{J} = 0$ means that current flow lines cannot end anywhere (as they do on capacitor plates in time-varying circuits). I say more about the intuitive physical interpretation of this discrepancy in my answer here. To cut a long story short, one way (not the only one) to get rid of these inconsistencies is to postulate that the RHS of Ampère's law should instead be $J+\partial_t \vec{D}$; then if you take the divergence of both sides of Ampère's law you get the continuity equation $\nabla\cdot\vec{J} = -\partial_t \rho$. This is exactly what Maxwell did.
Once this is done, it can be shown that all the six Cartesian components of the electric and magnetic field vectors in freespace fulfill the D'Alembert wave equation:
$$c^2 \nabla^2 \psi = \partial_t^2 \psi$$
which is the equation for a dispersionless wave. To see this, in one spatial dimension the equation is:
$$c^2 \partial_x^2 \psi = \partial_t^2 \psi$$
and its general solution is:
$$\psi = f(x-c\,t) + g(x + c\,t)$$
where $f$ and $g$ are arbitrary, continuously twice differentiable ($C^2$) functions. They are equations for pulses with invariant shape (defined by $f$ and $g$) running at speed $c$.
Comment: Two reasons: reason 1: Check my age on my user page! When I was doing my PhD, my supervisor used this notation and Born and Wolf was a heavily read text in the field. Reason 2: as a bivector, the outer product is indeed the antisymmetrised geometric product. However, whilst I do like the presentation of geometric algebra a great deal, I don't believe it's quite worth evangelising as vigorously as some do. It's simply an excellent way to present already living and well understood ideas in Clifford algebras and general tensor analysis. So I'd call something like Doran and Lasenby ....
Comment: ....a great piece of technical writing, but not new science.
Comment: I noticed you use the $\wedge$ notation from geometric algebra; do you find geometric algebra useful or was that just a notation convention you use? GA seems to have some rather vocal proponents, but I hardly ever see it used anywhere and I don't really know much about it.
Comment: Okay, makes sense. I started learning about it, but I kept noticing that most GA texts seemed to spend roughly 1/3 of the text preaching about how revolutionary GA was, how it will replace vector algebra in a couple years, how it's superior to vector algebra, how "Dirac and Heisenberg would have used it if they had known about it", and other such grandiose claims. I came away from the reading with a distinct impression that it had been written by a used car salesman, but figured a second opinion might be helpful.
Comment: @DumpsterDoofus LOL! Yes, there is certainly the used car salesman quality to it. But I believe *if you don't already know about tensors and clifford algebras in particular* that this kind of thinking is a good way to learn *known concepts*. It is certainly true that the "standard" vector calculus notation (essentially Heaviside's /Gibbs's notation) is quite restricted in the geometric concepts that it can describe and it did displace alternative notations. The "evangelism" reminds me very much of proponents of different computer languages, and the debate underlying it is very like that in ...
Comment: ...character, but the truth is there is no one tool that fits everything. You might find this interesting: http://worrydream.com/refs/Crowe-HistoryOfVectorAnalysis.pdf

Maxwell's Theory Of Wave Propagation


If $\sqrt{28x}$ is an integer is $\sqrt{7x}$ always an integer?

Question: If $\sqrt{28x}$ is an integer is $\sqrt{7x}$ an integer? I have a book that says no, but I cannot think of an example of the contrary... Not looking for a full proof here just wanting to see a counterexample or logic showing that the book is wrong...
Comment: If $2A$ is an integer, is $A$ an integer?
Comment: Just a comment:  You say you want to "check your logic".  But you haven't actually told us what your logic is, other than "I can't think of a counterexample."  In general, "I can't think of a counterexample" is *not* good logic at all.
Comment: Notice that $\sqrt{28}=2\sqrt{7}$
Comment: mweiss, great point. Sorry for the poor word choice. I've changed the question to better reflect what I mean.
Answer:
I cannot think of an example of the contrary $\dots$ just wanting to see a counterexample

Would $~x=\dfrac1{28}~$ satisfy your curiosity ?
Comment: It is outright mind-boggling how my most basic answers are also the ones gathering the most upvotes.
Answer: Consider the first part $\sqrt{28 \, x} = \pm n$, $n$ being an integer. Then one finds
$$x = \frac{n^{2}}{28}.$$
Now consider the second part
$$\sqrt{7 \, x} = \sqrt{ \frac{7 \, n^{2}}{28} } = \sqrt{\frac{n^{2}}{4}} = \pm \frac{n}{2}.$$
This shows that if $n$ is not an even value then the value of $\sqrt{7 \, x}$ is not an integer.
Comment: Presumably you meant to write "an even integer" rather than "an even function", correct?
Comment: Why is it that the positive root of $7x$ can yield a negative number? Wouldn't it just be $\sqrt{7x}=\frac{n}{2}$?
Answer: Note that $\sqrt{28x}=\sqrt{4\times 7x}=2\sqrt{7x}$. Can you see what might happen so that $\sqrt{28x}$ is an integer while $\sqrt{7x}$ is not?
Answer: Suppose x is an integer.
Then 28 * x is always even, since 28 * x = 2 * 14x.
The square root of an even number, is never an odd number.
(Check that odd * odd = odd)
So if you take examples where x is an integer, sqrt(28x) is never odd, and therefore there exists no counterexample.
So x must be a fraction to find a counterexample, (like 1/28 or 9/28).


Docker + SSH + Git Clone Issue

Question: I have read so many issues about the same exact thing tonight, but I'll be damned if any of the solutions actually worked for.
Simply put, I need to clone a private Git repo hosted on GitHub to my docker image.
This is what I have thus far in the Dockerfile:
FROM debian:wheezy
ENV DEBIAN_FRONTEND noninteractive

# Update aptitude with new repo
RUN apt-get update

# Install software
RUN apt-get install -y \
    # All of my packages here...

# Make ssh dir
RUN mkdir /root/.ssh/

# Copy over private key, and set permissions
ADD ssh/id_rsa /root/.ssh/id_rsa
RUN chmod 700 /root/.ssh/id_rsa
RUN touch /root/.ssh/known_hosts

# Add GithHubs key
RUN ssh-keyscan -T 60 github.com >> /root/.ssh/known_hosts

# Create the Development directory and then move into the directory.
RUN mkdir -p /var/www/dev
WORKDIR /var/www/dev

# Start-up Git and pull in the Dev branch.
RUN ssh -v email@example.com
#RUN git init
#RUN git remote add origin firstname.lastname@example.com:<my_git_repo>
#RUN git fetch
#RUN git checkout -t origin/dev
#RUN git clone email@example.com:<my_git_repo>

ssh -v gives me the following debug log:
OpenSSH_6.0p1 Debian-4+deb7u4, OpenSSL 1.0.1e 11 Feb 2013
Pseudo-terminal will not be allocated because stdin is not a terminal.
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to github.com [18.104.22.168] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version libssh-0.7.0
debug1: no match: libssh-0.7.0
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.0p1 Debian-4+deb7u4
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-sha1 none
debug1: kex: client->server aes128-ctr hmac-sha1 none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: RSA 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48
debug1: Host 'github.com' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:1
Warning: Permanently added the RSA host key for IP address '18.104.22.168' to the list of known hosts.
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/id_rsa
debug1: key_parse_private_pem: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Trying private key: /root/.ssh/id_ecdsa
debug1: No more authentication methods to try.
Permission denied (publickey).

I have tried the option of setting StrictHostChecking to no.  I have tried a separate config file under the SSH directory to specify host, port, identityfile (being the private key, not the public one).
What am I missing here?  The key on the VM that is created is precisely the same as what I have on my local machine.
Comment: "read_passphrase: can't open /dev/tty: No such device or address": is your private key pass-phrase protected?
Comment: Don't use root account
Answer: It might be better to use a GitHub personal access token instead of your ssh key.
https://help.github.com/articles/creating-an-access-token-for-command-line-use/
This removes the need for you to bake your ssh key into the image, which is more secure, and it allows clones over https, which should simplify your dockerfile. If you need to revoke the token, it is easy to do from their website, and you don't need to replace your personal ssh key everywhere.
If you looked at this, and can't use this option, let me know and I can help you figure out the ssh key issue.
Answer: One of the problems could be that the .ssh/config file needs to have specific permissions. Trying using permissions 600 i.e. rw- --- --- instead of 700 i.e. rwx --- ---.
Tip for debugging
You can try to execute the following inside the container to make sure that the setup works:
ssh -T firstname.lastname@example.com

If everything is setup properly,  you should see:
Hi username! You've successfully authenticated, but GitHub does not provide shell
access.

Alternate Strategy for Cloning Private Repositories
When it comes cloning private repositories inside docker, I use the ssh agent session on the local host inside the container, by mounting the relevant socket. Details can be found here: https://ahmadnazir.github.io/posts/2016-06-24-accessing-private-repos-in-docker.html

Docker + SSH + Git Clone Issue


Parity signer new-token unable to parity on the CLI

Question: I had issues during the install and re installed the account.
It is asking for parity signer new-token that clearly needs to be entered o the command line.
This is installed on OSX, I can see the .parity folder but nothing of note in there. If I run a command such as parity -h (help) or any variation it is clearly not installed. Where is the CLI command run from?
Comment: Would you mind posting the commands put and errors received?
Answer: If you installed Parity via Mac-Installer, the executable is not in your default $PATH of your terminal emulator. You can, however, access it directly by executing:
/Applications/Parity\ Ethereum.app/Contents/MacOS/parity --help

To generate a new signer token, type:
/Applications/Parity\ Ethereum.app/Contents/MacOS/parity signer new-token

Disclosure, I work for Parity.
Comment: Thanks for the reply. I have located the folder and the only file present is the go.sh file. That only points to the local server at port :8080. If I run the app from the link on launchpad it takes me to the web portal where I can see accounts details in the background greyed out with the splash screen for new signer key. I have had look in specific users but is is not in there either? Any other thoughts? Where are the keys kept? Is it worth a complete reinstall? Thanks
Answer: How did you install parity?  From source or some sort of binary installer?

Where are the keys kept?

The keys may be in ~/.local/share/io.parity.ethereum/keys
They may also be in ~/.parity/keys
The difference is annoying but seems to be the result of building from source vs. installing from binary.
The binary is very likely in ~/parity/target/release/parity if you complied from source.  If you install from a .deb file it's in /usr/bin/parity.  Of course on OSX you don't install from deb file so I don't know.
Have you tried typing
$ which parity

Or how about:
$ find / -name 'parity'

Answer: If you used the one-line installer to install Parity on Mac OS, your terminal won't know the path to where Parity is installed. Simple way to solve this is by appending an alias under your ~/.bash_profile file by running the following command:
echo "alias parity='/Applications/Parity\ Ethereum.app/Contents/MacOS/parity'" >> ~/.bash_profile && source ~/.bash_profile

You can now run parity from your CLI:
parity ui


Does The Entire Orthodox World Hold Rashi In The Same Regard?

Question: I know how integral Rashi's Torah Commentary is in the Askenaz community (in their Yeshivot they begin teaching it pretty much as soon as kids can read). I was wondering if this was also true in the Sephardi & Mizrachi world?
Comment: Ive always heard Rashi being taken very seriously in the Sepharadi world. But I would describe it kind of like the reverence toward the Rambam. Most Sepharadim don't follow the Rambam directly but he is given the respect as if he is correct in all matters. So in that vein no one disregards Rashi, the respect is given, but when push comes to shove another commentators opinion can override Rashi without much of a fuss
Comment: Whereas I feel like Ashkenazim are much more hesitant to deviate from Rashi's or accept an opinion that runs counter to Rashi.
Comment: @Aaron "Whereas I feel like Ashkenazim are much more hesitant to deviate from Rashi's or accept an opinion that runs counter to Rashi." That just isn't true. There are many mefarshim on the Torah, and Rashi is perhaps the best and easiest to use. But the other mefarshim constantly disagree with him and no one has any problem with it, Ashkenazi or Sefard or whatever.
Comment: @Aaron That isn't true at all. There are even other Ashkenazi meforshim who disagree with Rashi.
Comment: I am not trying to say that Ashkenazi commentators do not disagree with Rashi. Even Rashis grandson disagrees with Rashi. But in a very orthodox setting most lay Ashkenazim that I've seen do not feel so comfortable straying away from Rashi.
Answer: It is true in the Sephardi world too. So for example, the Ramban writes in the  introduction to his commentary on Chumash

I will place as an illumination before me The lights of the pure candelabrum,  The commentaries of our Rabbi Shlomo [Rashi], A crown of glory, and a diadem of beauty, Adorned in his ways, In Scripture, Mishnah and Gemara. The right of the first-born is his.

The primary commentary on Rashi was written by Rabbi Eliyahu Mizrachi, who was of Sephardic heritage.
In addition, the Shulchan Aruch rules that one can use Rashi instead of Targum Onkelos to review the weekly parsha. No other commentary has that status.
Comment: No other commentary has the status of being mentioned for that purpose in Shulchan Aruch, but surely most straight semi-pshat running commentaries are equally valid halachically. That's just the example commentary of the Tur (who was born in Ashkenaz) which the Spanish born Shulchan Aruch hedges against actually following, so not such a great proof.
Comment: This list many "classical" Spanish names, but the question seemed more interested in the contemporary practice.
Comment: I will look for the source but the Rambam says that he wanted to write a commentary on the Gemara but "the Frenchie beat me"
Comment: I've seen the supposed quote. He said הצרפתי, which has no negative connotations. I doubt he actually said that though.
Answer: I'm pretty sure Rashi is respected equally by both Sephardim and Ashkenazim. I can't imagine anyone Orthodox learning Torah without Rashi.
Comment: Were there no Orthodox Jews prior to the eleventh century?
Comment: Rashi's commentary is certainly the most popular/widespread. But it seems like quite a leap to being unable to imagine anyone Orthodox learning Torah without Rashi.
Comment: Note also that most of what Rashi said is from the Talmud and the midrashim.
Answer: Rashi's commentary on the Torah and also on the Talmud is pretty much universally studied by all Jewish communities; even Yemenite communities printed Rashi in their Chumashim as you can see in this example here. Most of what Rashi says isn't his own idea anyway but rather quotations from various Midrashim familiar by all Jewish people regardless of location. By the way, before the age of enlightenment and the rise of the Reform Movement in Germany there was no such thing as the label "Orthodox". If you were a Jew, you were a Jew, and you either observed more or observed less.


Hang a heavy mirror without hooks

Question: Desperately need to hang my tall leaning mirror because of a crawling toddler at home. The mirror has no hooks and no place to attach hooks. There is a slight gap between the frame and the back of the mirror so cant mount it using wall adhesives. Any suggestions?
Comment: How thick is it overall? You may be able to get mirror brackets/clips thick enough.
Comment: what is the frame material? ... what is the backing material?
Comment: Weight of mirror?   The frame looks very thin and may not support the weight of the mirror if hung.   If the bottom seams are tack welded, they could easily come apart if the weight of the mirror is meant to be supported by being on a solid surface.
Comment: Is that the back of the mirror we're looking at?  Or is it some kind of MDFish sheet?  Gotta pic of the front of the mirror?
Comment: The frame is metal and the back of the mirror is a thin mdf sheet. The mirror seems to be around 15-20 lbs. This picture is the back of the mirror, the front is plain mirror with a slightly thicker frame width. The frame at the bottom would be about 1.5" thick
Answer: Glue a cleat to the back and hang on second cleat fastened to wall. You can cut your own cleat or buy metal hanging cleats.

Ref: https://en.wikipedia.org/wiki/French_cleat
Or glue vertical 1/2 or 3/4 strips (plywood, 1x lumber) near outer vertical edges (left and right), run a frame wire, and hang it over a hook (or multiple hooks) fastened into the wall.

Ref: amazon.com
Comment: is the brown wooden backing part of the mirror suitable to carry the load of the whole mirror? do you know that? On some furniture, this part is very thin and mainly serves to block light.
Answer: I'd suggest using standard mirror hanging clips. These happen to be plastic:
Source: Home Depot. No recommendation implied or intended
This happens to come in an 8-pack (other sizes and brands are available). You note that the mirror is "heavy", but don't indicate exactly what that means. I'd suggest that 5 of these clips spaced along the bottom (to support the weight), then one on each side and one at the top (to keep it from tipping away from the wall), would likely do the trick. You would want to ensure that at least a few go into studs in the wall to ensure you're supporting the "heavy" weight adequately, otherwise, these screws will just pull right out of drywall. You should, of course, adjust that as you see fit and to meet your safety requirements. Purchasing more clips would allow you to put more along the top/sides if you felt that was necessary.
If you don't like the look of plastic ones, you could make something similar out of wood. If you have a table saw and router, these would be pretty easy to make. If you don't, maybe a friend or neighbor has one, or you could find a local woodworker/cabinet maker - I'm sure they'd bang out as many as you'd like for a small fee.
Answer: There are self-adhesive Velcro-ish tapes and pads designed to carry a reasonable amount of shear force, and you can of course use more of them to make the connection more secure and distribute the force better. They can tolerate a slightly irregular surface. I've used that approach to hang a large (3'x5') 1/4" plywood panel and it has held for a decade. Only downside I can think of is that there will be a small gap between mirror and the surface it is mounted to.

Hang a heavy mirror without hooks


how to clear phone number and user from about device status - galaxy S5

Question: Getting my Sprint Galaxy S5 ready to sell.  I've tried factory reset.  Even went into android recovery menu and wiped cache and factory wipe reset.  Yet when I go into settings -> about device -> status:  I see my user names (something like firstname.lastname@example.com) and my phone number!   How do I wipe this?  I think I found the answer once before online when I was selling another phone a few months ago, but can't remember what it was.  I think I had to type some special ## into the dial pad to get it to wipe.  I think the info is store on the sim card.  Please help.
Answer: I found the answer.  Dial ##72786#   This restores all phone setup information to the original factory settings.  It is NOT the same a factory reset.  It removes completely the old phone number and old user name from the phone.
I found the answer here, near the bottom of the page; post #13 on the page:
http://forums.androidcentral.com/sprint-galaxy-s-ii-epic-4g-touch/254641-how-do-i-remove-my-user-name-phone-etc-settings.html
Answering my own question to hopefully help someone else ;-)


What is the "Category" argument in user_save for?

Question: I'm working on a custom module that edits the user's details. I'm using
user_save($user_entity,$new_field_values);

But I see there is a third argument in user_save called "category". What exactly is it for?
Answer: As you see in user_save function it tells that

category: (optional) The category for storing profile information in.

It basically used in below lines of code inside user_save function
user_module_invoke('presave', $edit, $account, $category);
user_module_invoke('update', $edit, $account, $category);
user_module_invoke('insert', $edit, $account, $category);

So, the information is just passed to all presave, update, insert hooks so that they can take contextual actions.
In user_module_invoke function $category is defined as

$category: The category of user information being acted upon.

So, from above it clarifies that is used as a value to tell all hooks that we are saving user details and on which part of user information we are acting upon. Something like if we change the user organic groups that he belongs to then we can specify that $category as "organic_group" .
For Example if you see hook_user_presave in user module
/**
 * Implements hook_user_presave().
 */
function user_user_presave(&$edit, $account, $category) {
  if ($category == 'account' || $category == 'register') {
    if (!empty($edit['picture_upload'])) {
      $edit['picture'] = $edit['picture_upload'];
    }
    // Delete picture if requested, and if no replacement picture was given.
    elseif (!empty($edit['picture_delete'])) {
      $edit['picture'] = NULL;
    }
    // Prepare user roles.
    if (isset($edit['roles'])) {
      $edit['roles'] = array_filter($edit['roles']);
    }
  }

  // Move account cancellation information into $user->data.
  foreach (array('user_cancel_method', 'user_cancel_notify') as $key) {
    if (isset($edit[$key])) {
      $edit['data'][$key] = $edit[$key];
    }
  }
}

You can see the use case of $category above where they check for account or register !
In your case just make it as an optional and don't assign any value :-)
Answer: $category is one of the strings returned from any implementations of hook_user_categories(). Think of them as a different tab that is visible in the form for editing a user profile.
By default, the User module defines just the "account" category, which contains all the data about the user account.
function user_user_categories() {
  return array(array(
      'name' => 'account',
      'title' => t('Account settings'),
      'weight' => 1,
    ));
}

Other modules can define new categories. In Drupal 6, the Profile module was one of those modules, which implemented hook_user_categories() with profile_user_categories().
function profile_user_categories() {
  $result = db_query("SELECT DISTINCT(category) FROM {profile_field}");
  $data = array();
  foreach ($result as $category) {
    $data[] = array(
      'name' => $category->category,
      'title' => $category->category,
      'weight' => 3,
      'access callback' => 'profile_category_access',
      'access arguments' => array(1, $category->category),
    );
  }
  return $data;
}


How do you judge the potential of a newer journal?

Question: I'm in a fairly niche field that is still in the process of organizing itself. As such, there are a number of existing professional societies that are spinning off journals along with newer societies that are getting into journal publication. Since some of the usual metrics for judging a predatory journal may not apply, how do you judge the potential of a newer journal so that the publication does not end up being a wasted effort?
Answer: To expand upon part of Dave Everitt's answer,

look at the founders of the journal - did they start it primarily as a platform for their own publications, and do these authors and their associates make up the bulk of the authors?

I would also look at who is publishing and editing the journal.
Is the publisher affiliated with a scientific society? Sometimes scientific society will launch new journals (e.g., the Ecological Society of America launched Ecoshpere to be their open source journal).
Or another is a new journal from an established publisher? Established commercial publishing companies are launching new journals. Although people argue about the ethics of publishing with them (cf What are some examples of negative effects on a career for boycotting Elsevier journals?), my own experience has been that their products are usually scientifically sound (presumably because they are afraid of hurting their brand image). Additionally, journals such as Nature now have spinoffs (and spinoffs of spinoffs, e.g., Nature to Nature Methods to Scientific Reports) to catch paper that do not fit into their flagship journals.
Also, who is the editor-in-chief and other editors? Do you know them in your sub-field? For example, when the journal Theoretical Ecology launched, the they had Alan Hastings as the EIC, a highly respected Ecologist.
Comment: Then again, established publishers like Elsevier sometimes publish things like *Chaos, Solitons and Fractals*...
Comment: @RichardErickson: the editor-in-chief, Mohamed El Naschie, published a *large* number of his own articles in that journal, some of which were, ahem, not judged as of high quality by peers. [The section in the Elsevier Wikipedia article](https://en.wikipedia.org/wiki/Elsevier#Chaos.2C_Solitons_.26_Fractals) hints at this. There was much more at various academic blogs. Frankly, I'm a bit amazed Elsevier didn't discontinue the journal after that, like [airlines retire flight numbers after crashes](http://aviation.stackexchange.com/q/33766).
Comment: @StephanKolassa - but I don't think they set out for it to be quite what it is - once launched it may just not catch on with the intended audience, leaving it to fend for itself...
Comment: @StephanKolassa I'm not familiar with that journal or the story behind. Would you care to elaborate? (or if you don't, I completely understand as well).
Comment: **"...presumably because they are afraid of hurting their brand image"** —this is a double-edged sword at best; from my viewpoint it is wholly a negative trait for a scientific journal.  Accurate scientific observations can and *should* challenge common assumptions.  "Worry about reputation" has no place in a search for truth; accuracy, not politics, should be all that matters.
Comment: @StephanKolassa Thank you for sharing that story. I had never heard of that occurring before. (I believe it,  I've just never had never saw it before).
Answer: Is your niche field organizing it?
If you are in a fairly niche field, then you should know most of the significant people in that field - and preferably actually know them, not just their names.
I strongly believe that a new niche effort (no matter if it's a journal, conference or association) can be successful and worthwhile only if it's done by those people (or a significant part of them) in order to fill their own niche needs. No matter if they come from different organizations (of course they do) or they haven't a single specific association (which most new fields don't have), there is a "virtual community" of people interested in that field and working on it.
Are the key people you know involved in that journal?
Regardless of that, maybe ask them directly about that journal? In the end, it's their opinion that will determine whether that journal will be successful, not any arbitrary metrics.
Answer: A suggestion checklist for new journals

check who has been published in the journals - are they notable contributors to the field, or all from one research group?
circulation - try to find out how many copies they print (if printed) or readership numbers
look at the founders of the journal - did they start it primarily as a platform for their own publications, and do these authors and their associates make up the bulk of the authors?

Having said that, although most fields have their primary journals, and new ones have to start somewhere, you can still use the above to litmus-test a new journal (as well as the vanity journal tests e.g. would they accept your paper without any peer review?).
Finally, beware of the new swathe of bogus journals, promoted by well-disguised spam targeted at academics via their university email addresses, for example, see: Journal accepts bogus paper requesting removal from mailing list(!) and Murky world of 'science' journals a new frontier for climate deniers


Shouldn't MSDS data on products be publicly disclosed?

Question: I am wondering whether companies are required to disclose MSDS data on their products: toxicity, $\mathrm{LD_{50}}$, etc. Not only that, but I am wondering whether they are required to disclose the methodology that they used. I know that this isn't a legal forum, but some companies that I asked are unwilling to give details on how the toxicity was tested. What are some laws that are in place (regardless of country)? I thought that all MSDS data should be public.
Comment: Companies are required to have SDS (don't know why they changed from MSDS to SDS recently, but...) sheets for chemical products they sell. What you see conforms to US federal regulations. It is highly unusual for a company to do their own toxicology (if it is even done). That is done to standards established and controlled by national or international industrial hygiene associations. I have seen (and used) many specialty chemicals where such testing had not been done, so no data was listed since there was none. There is no requirement to perform it for a new chemical.
Comment: Yes, it is legal. Perhaps not ideal, but legal. If you still have concerns, discuss with your nearest IH person (industrial hygiene).
Comment: @JonCuster The thing is that some companies have nearly 30 entries missing. I am looking at some cleaning products...They have No data available on environmental hazard part. Data missing on inhalation. There is no acute exposure limit. Irritation data is missing. Is this even legal..? It says it got approved by the nation's msds lab..
Answer: There is a bit of a misconception here.
Of course, the material safety data sheet (MSDS) is publicly available. Just go to your favourite chemicals supplier, type in your substance and download the corresponding MSDS in your language for your jurisdiction. At least in Europe that is mandatory for all chemicals a company sells; I would be very surprised if there is any developped country where making MSDS publicly available be not mandatory.
On the other hand there is the question of how a value was determined. That is not necessarily public information. Of course, there is a set of standardised tests that companies would perform, but they don't have to exactly mention whether they used method A or method G. They also have a reason to be nondisclosive about this: imagine an animal rights activist calling you pretending to just be an interested scientist and then using the information they get on the phone to start a name-ruining anti-ChemicalCompany campaign. You don't want that, do you? And then, of course, there is the general secrecy issue. If you just invented a compound you want to put on the market as a drug, you don't want anybody knowing anything about it until you've started selling it.
Of course, government bodies have a certain reason to know how the tests were perfomed and what the raw results were (otherwise the company could just print a number on their MSDS which the responsible person invented on the toilet). But you're not government. You'll have to somewhat trust the government to properly monitor the companies in question.
Of course, the chemist who works safely doesn't need to know how dangerous something is. They will work with it in a way that they are not affected.


Can an object precede its verb?

Question: The structure of "have one's heart set on something" idiom is strange for me. Isn't "heart" the object? So why it is not as "have set one's heart on something"?
Answer: "Have"
Understand "have one's heart set on something" by analogy with these:

(1) John has his car in the garage.
(2) John has his car safely stored in the garage.
(3) John will make his heart invincible.

or even:

(4) John will have his car repaired on Thursday.

You can't re-order these sentences without altering the meaning. In (1), there's no additional verb, analogous to "set" in your example, to move around. In (2), you could say "John has safely stored his car in the garage", but that would be a different sense of "have": that would be "have" as an auxiliary verb combining with "stored" to make the present perfect tense. In "have one's heart set on something" and the examples above, "have" is not an auxiliary verb. It's the main verb, and it indicates causing or directing something to happen on your (the subject's) authority or decision or simply by your nature.
There is no single, official way to analyze these sentences into grammatical terminology. Here's how I understand them: this sense of "have" takes two complements: first an object, then a predicate. The predicate is something that the subject "has" (or "makes") true of the object. I'll enclose them in parentheses:

(1) John has (his car)object (in the garage)predicate.
(2) John has (his car)object (safely stored in the garage)predicate.
(3) John will make (his heart)object (invincible)predicate.
(4) John will have (his car)object (repaired on Thursday)predicate.
John has (his heart)object (set on a Ferrari)predicate.

The construction where a verb takes two complements, first an object and then a predicate, also occurs with the verb "let", which is used very commonly and for many purposes:

Let (me)object (out of John's car!)predicate

The predicate is often called an "object-complement".
"Set"
In your example, "heart" is not the object of "set". The relevant sense of "set" also occurs in these sentences:

The television is set on channel 2.
The Enterprise is set on a collision course with Alpha Centauri.

and perhaps even:

John's decision might as well be set in stone.

You could re-word these sentences to make "set" the main verb. But in these sentences, "set on/in sth" is a predicate, attached to the subject (television/Enterprise/John) by the verb "be", following the same pattern as "The cat is black." A predicate is an abstract quality that in principle could be attached to anything. Sometimes people say that "set" in these sentences is passive, but that's an error. "Set" in these sentences describes a state, not an action.
Comment: @Ben Kovitz - Hi Ben, in what sense do you use the term predicate? I know predicate only as used in Latin grammar, but your use of the term is new to me.
Comment: @rogermue I mean "predicate" in its sense from traditional logic, which overlaps a lot with its use in traditional grammar. In a categorical proposition, there is something you're talking about, and something you're saying about it. What you're talking about is called the subject; what you're affirming or denying of the subject is called the predicate. E.g. in "the cat is black", the cat is the subject and blackness is the predicate. Predicates are always abstract. Logic usually regards "be" and "not" as something other than the predicate; grammar usually includes them.
Comment: Thank you, Ben. There is no end of learning with grammar terms. As a student I bought a dictionary about linguistic terms by Mario Pei. I really think I have to buy a new one.
Comment: @rogermue Or buy an old one! :) The old stuff surely has serious flaws when applied to English, but it makes the fundamentals clear. The modern stuff often seems to me to drown out the main insights in a vast sea of technicalities. BTW, [this page](https://en.wikipedia.org/wiki/Predicate_(grammar)) might shed some light.
Comment: Ben, Mario Pei,  A Dictionary of Linguistics, 1954, Peter Owens, London is excellent.
Answer: "To have" has a lot of constructions that are different from to have (meaning to possess) + object.
One of these special constructions is to have + noun + past participle. This construction can have several meanings.

John had his nose broken in a brawl.
Later John had his nose operated on in hospital.
The gangster had a car parked near the bank and escaped.

In 1 the construction is a variant for passive. You could also say: His/John's nose was broken. Or: John got his nose broken.
In 2 the construction has the sense that John arranged that his nose was operated on.
3 Here "had" has the normal sense of to have. He had a car available. It was parked near the bank.
You have this construction also in a lot of fixed verbal expressions as to have one's heart set on something.

She had her heart set on a little house with a garden.

Meaning it was her desire. Her heart was in a special state, it was set on a house with a garden.
Hornby had this verb construction in pattern 9. A pity that there are no explanations.
Answer: Both are possible and there's no difference between them. It's the same structure as "look a word up" and "look up a word".
Comment: Thanks, But isn't "heart" the object of "set"? So, can it precede its verb?
Comment: "set", the pastvparticple, here has adjective character. "She has her heart set on a little house" is similar to "Her heart is set on a little house".  "heart" is object of "has".

Can an object precede its verb?


Anyone can recommend a free and easy-to-use UML diagramming tool for beginners?

Question: I'm trying to find a tool for creating UML diagrams for my work. Usability is a major criteria for me. I'm just starting out,many things to learn. Free would be great, but I would be glad to pay if the tool's worth it. Anyone have a good recommendation?
Answer: I use Papyrus, an Eclipse extension. Usability is good enough if you are not up to complex stuff like profiles. But you get all the benefits of Eclipse integration, easy versioning, etc.
If you are up to code generation then Papyrus + Acceleo is the pretty much the only option around.


IP whitelisting across Service and Marketing Clouds

Question: If I whitelist my IP addresses to access Service Cloud instance for my business do I need to re-do the same for Marketing Cloud? I assume so as Marketing Cloud is hosted elsewhere to service cloud but want to check.
Answer: Correct - you need to whitelist two different sets of IP addresses for Sales Cloud and Marketing Cloud. You can find the relevant IP addresses here:
Core (Sales Cloud, Service Cloud, Community Cloud)
Marketing Cloud


Why does the Linux Mint 19.1 boot menu show before the Windows boot menu?

Question: I have an SSD and an HDD. I've created separate partitions for Linux on the HDD (SWAP,boot and the storage), but I installed it on the the SSD on "Device for boot loader installation". I want to know what happened and skip the Linux Mint boot menu if it's not mandatory. Have I done something wrong in the installation?
Answer: You did it right. GRUB2, the aforementioned Linux Boot Loader, has Mint set to appear first, above Windows Boot Manager. It's the design of the program.
GRUB2 has many features, and you can edit GRUB2 to make Windows Boot Manager appear first.  That editing is a non-trivial process, as you will see when you read the last previous web link.
First, in the current GRUB2 menu, note the items which apear, and the line they are on.
In a terminal window, execute (you can substitute any text editor for nano, FYI)
sudo nano /etc/default/grub

and find the line with

GRUB_DEFAULT=0

GRUB2 starts counting from 0. you see. In the editor, replace 0 with the number of the line Windows Boot Manager is on (starting with 0 at the top) and save the file, then exit. Execute
sudo update-grub

which tells GRUB2 to accept the changes. The next time you reboot, Windows Boot Manager will be at the top of the GRUB2 list.
This does not alter the installation nor which drive you installed Linux to.
Comment: So is Linux installed on my SSD or HDD partition now?
Comment: Added to answer


Meaning of "X need not apply"?

Question: I've seen this a bunch of times before, largely in TV/movies, where someone will be looking at a job posting and it will say "X need not apply". Does this mean as in "there is no reason for X to apply", or does it instead mean "X MAY NOT apply"?
Comment: Using ***need*** rather than ***may, must*** is just a "euphemistic, softening" device in such contexts. The *"X need not apply"* usage is a set phrase, which would never be rendered as *"There is no need for X to apply"* (that version might in some contexts mean X's don't need to apply because they'll be automatically *included* without even needing to go through the application process).
Answer: "X Need Not Apply" is a discriminatory message that essentially means "If you're X, don't bother applying because we won't hire you." For example, "No Irish Need Apply" signs were part of a wave of discrimination against Irish-American immigrants. That's probably the most well-known instance of it, and most "X Need Not Apply" signs in fiction are probably a reference to it. For example, a short about how automation is replacing human work was titled "Humans Need Not Apply."
Answer: It means the former.  Need here is being used as an auxiliary, adding a sense of obligation, requirement or benefit/reward to the main verb (apply, in this case).  Since it is paired with not, the meaning is that there is no reward.
If the writer of the job posting had wished to specify which skills are important for the job, they could have written

Only Y need apply

where Y indicates a suitably qualified applicant.
The lack of reward or requirement does not imply a total prohibition.  The unqualified may apply; it will simply do them no good.
It is worth noting that while you may have seen this often in fiction, it is much less likely to be used in real life as the author would risk accusations of discrimination (and possible legal action).  It is much safer to present a firm description of the positive attributes sought than to rule out qualities seen as a disadvantage.
Answer: Certainly it usually means "X will not even be considered, so need not waste our time by applying". However, in some cases it means "X will automatically pass, so need not waste their time by applying." The canonical case is a job advertisement saying 'Previous applicants need not apply'; does that mean "We already have your details on file; we will contact you if you are one of the people we need" or does it mean "You failed last time, don't bother us again"? The correct answer is that it doesn't matter: either way there is no point worrying about this job.
The literal answer to the question asked is "The first of your options, though the reason why you need not apply may not be what you expect. Need not in this case means literally that there is no point in applying; whether you take that as equivalent to may not apply is up to you."

Meaning of "X need not apply"?


Minecraft Voltz Server Slow when linked with Domain

Question: I have Voltz Server on my Ubuntu Server that can be accessed using both a domain name that is linked to my Public IP address and my actual IP Address. For some odd reason, when I want to connect to my server using the domain, the reception of the server is 1 bar, but when I log in, there is no ping spikes or nothing. When I connect using a local IP address it is fine, full bars. Anybody have an idea of a possible solution?
Comment: Sounds like there's something between you and the server when using the name. On your Ubuntu box, if you run `host (domainname)`, do you get the exact IP of the machine, or something else?
Comment: Do I just go to /etc/hosts? @MikeyT.K.
Comment: The file only holds things you've forced to resolve to one name or another. the `host` command actually resolves the domain and shows you what the result is. `nslookup` will do the same.
Comment: Flagging as off-topic because it is asking more about the internet than anything game-specific.
Answer: It takes longer because the packets are travelling a longer distance
If you're using the domain name, it doesn't know where that is. So it asks, and gets an answer: your public IP address.
It then looks up how to contact that IP address. It doesn't know that IP address goes to itself. So it asks your router, which also doesn't know, which then asks your Internet Service Provider's routers, which may know, or may pass the request further out, until it finds a server that knows how to contact that public IP address.
Finally, it reaches a server that can see that public IP address and then it creates a connection between your computer and that computer — which is your computer but it still doesn't know that — and passes messages back and forth along that whole chain. So when you use your public IP address, your Minecraft client and server are talking to each other over a long loop that goes way out into the public Internet and then back through your ISP to your computer.
That's a lot of extra time for your Minecraft client to finally get to talk to your Minecraft server about each tick! By comparison, using your actual IP address makes only 1 hop (or, if your network is configured cleverly, none), which is much faster.
To draw an analogy, connecting to your public IP address via domain name is like sending your roommate a note that it's their turn to clean the kitchen by putting it in an envelope with their name and address and sending it through the national mail system, when it would be much faster to just slide it under their bedroom door.
To illustrate this with numbers, I sent a set of tiny messages (pings) to my public IP address. The average ping time for that long round trip was 2.335ms. Sending the same thing to my actual IP address was 0.105ms — a 22× speed improvement. It was slightly faster even when I used the shortcut IP address that means "this computer" (127.0.0.1, also available as the DNS name localhost), at only 0.094ms — a 25× speed improvement.
So the moral of the story is, when connecting to a Minecraft server on the same machine as your Minecraft client, always use the domain name localhost instead of your public domain name or IP address.


Capacitor problem: What's wrong with this?

Question: The capacitor shown contains 3 different dielectric material $\epsilon_1,\epsilon_2,\epsilon_3$ between the top and bottom metallic plates on which lie teh points $A$ and $B$ as shown. The electric field is oriented along the vertical direction (neglecting fringe effects). Because of the continuity of the electric field $D$ across the interface $CD$ we have $\epsilon_1E_1=\epsilon_2E_2$ and therefore $E_1\ne E_2$ for different dielectrics. But continuity of the tangential field across $AB$ (at different points) demands that $E_1=E_3=E_2$. What's wrong with it?
My intuition is that the field cannot change abruptly on interfaces like $AB$ since it is basically generated by the contributions from surfaces charge area elements carrying charge density $\sigma$ and modified to take into account the polarization due to the dielectric - so they are actually $\sigma/\epsilon_i$. Each elements adds up a continuous field so the result of all the charges must be a field that varies continuously across $AB$ in some transition region. Since the only spatial dimension in the problem is the plate separation my guess is that this would also be the characteristic scale of the variation of the field. I would appreciate if anyone can confirm this.
Comment: Is it legitimate to ignore fringe effects along ACB?
Comment: Probably not. I meant along the outside edges of the capacitor
Comment: Yes I can understand that for edge D, but it would seem you can't ignore it at A-C-B because that would definitely seem to  be applicable to the transition to $e_3$.
Answer: As a commenter points out, it is not correct to ignore the fringe field along the line AB.


My Moyu Aolong V2 speed cube feels wrong after lubricating

Question: I just used some off-brand, hardware store silicone aerosol and let it sit for 15-20 minutes. Now, it turns very quickly, but the force needed to turn exceeds the force needed to turn it 45 degrees, meaning the absolute minimum i can turn it is 50 degrees or so. When doing a fast solve, I often end up overturing, leading to seconds off my time. I am new to cubing, and open to suggestion.
Answer: After applying the silicone spray, you'll want to keep rotating the layers while pressing the cube together slightly.
You should notice two things: firstly, some excess silicone will probably leak out from between the layers. Keep some paper ready to wipe it off, it can eat the stickers pretty bad if your cube has those. Secondly, after a couple of minutes, the stickiness should start to fade, and you get a smoothly moving layer.
Repeat for every layer in every direction.
Answer: I think your muscle memory will adjust to the looseness of the cube, so I don't think you have anything to worry about. With more solves, you should find yourself overturning less. For U and D turns, if you aren't already, you can hold the cube so that the same finger (index or ring) on the hand opposite of the finger making the turn rests slightly on the turning face. This way the resting finger tends to  stop the turn, aligning it to the cube sides.
Also, if you haven't already, you can try loosening/tightening your cube tensions for a better feel. If all else fails, you can always clean away some lube if that's the feeling you prefer. Since you're starting out, it's more important that you feel comfortable.


Is it possible to store audit trail information on reports ?if it is possible how can i enable the option allow reports/snapshnot on audit trail

Question: Is it possible to store audit trail information on reports ?if it is possible how can i enable the option allow reports/snapshnot on audit trail and then from reports to custom objects.i know that by using analaytical snapshot we can store reports into custom object
Answer: SetupAuditTrail is now a first class sObject. However its reportability is minimal. To me, the most interesting bits to filter on are the Display field (the actual audit message) and the Section field, broadly the type of audit.
Given the history of the Setup Audit Trail object and how it is used traditionally, the decision was taken to not make those fields filterable in SOQL. The object is also not reportable. More on that in a minute.
As part of some explorations around Salesforce Shield, and learning of this new object, I built a little POC component for Dreamforce 15. I wanted to know everything to do with "Encryption" and see all events.
I wound up having to do query of all events in the setup audit trail, then use regex to filter in Apex as follows:
public static List<SetupAuditTrail> getEncryptionAudits(){
    List<SetupAuditTrail> filteredAuditRecords = new List<SetupAuditTrail>();

    Pattern ptn = Pattern.compile('.*[E,e]ncryption.*');

    for (List<SetupAuditTrail> batch : [SELECT Action, Id, Section, CreatedDate, CreatedBy.Name, Display, DelegateUser FROM SetupAuditTrail ORDER BY CreatedDate DESC]){
        for (SetupAuditTrail item : batch) {

            //find if this audit row matches in the Section and Display fields

            Matcher matchSection = ptn.matcher(item.Section != null ? item.Section : '');
            Matcher matchDisplay = ptn.matcher(item.Display != null ? item.Display : '');

            if (matchSection.matches() || matchDisplay.matches()){
                filteredAuditRecords.add(item);
            }
        }
        // I was using this to make sure I wasn't banging up against heap limits
        System.debug(Limits.getHeapSize());
        System.debug(Limits.getLimitHeapSize());
    }

    return filteredAuditRecords;

}

I then piped this into a lightning design system based lightning component:

Ostensibly, this is the poor man's version of the paid-for feature of Event Monitoring that is offered either as its own line-item, or as part of the "Salesforce Shield" bundle.
To extrapolate, you could do something similar with reporting. Look for audit events around the creation and modification of reports, export them on a regular basis, etc. But the setup audit is for setup actions. Running reports will never be tracked here.
Alternatively, you could sign up for the Salesforce event monitoring system, which should track anything that is a potentially suspicious looking use of reporting. One of the profiled behaviors, I think, has to do with how reports are run.
Comment: hey how can display thes audit trial information in my visualforce page
Comment: Getting data from apex or an sobject into Visualforce is the most basic of Visualforce custom controller functionality. Check the VF docs and maybe take a look at the trailhead for VF. If you still have problems, post a new question. Here is the docs link: https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/pages_controller.htm
Comment: Here is trailhead for Visualforce Basics: https://developer.salesforce.com/trailhead/module/visualforce_fundamentals


nginx redirection/proxying, one domain(url) with two IP's

Question: We want to setup failover mechanism for one of java applications, application have 3 instances on one server and each instance must be accessed via different url, those url's are already registered and accessible via dns.
On secondary server we do replication (important part is that instances can be started and run only on one physical machine) therefore we established secondary server in case primary goes down, we wanted to register multiple IP's for one domain but it caused troubles since app's are designed to have only one IP registered to instance url. Another problem with multiple ip setup is round robin nature of dns. Is it possible to have registered two IP's for one domain and to proxy it via nginx or HAproxy to point to only master server? Or some other idea ? My idea is if primary goes down, turn on application on secondary server and change config on nginx side if possible to avoid dns registration and propagation time?
Answer: What I would do, is accept incoming traffic on the domain's actual name, and manually do the routing/failover yourself.
i.e.
example.com > nginx server > server1. (if failed) > server2.
 http {

    upstream java-app {
        server $primary-server;
        server $secondary-server  backup;
    }

    server {
        location / {
            proxy_pass http://java-app;
            proxy_set_header Host "example.com";
            proxy_next_upstream error http_502;
        }
    }
}

By using this method, your backend servers don't need to worry about the DNS. Only Nginx will have the DNS records pointed to it. Your backend servers will just have to worry about dealing with the incoming traffic, and if primary-server dies... secondary will take over!
By adding the host header in there, your backend servers can still match on the "host" header in their code too. :)
Comment: thnx for help i managed to create it, but now nginx is my single point of failure, i know it is easily possible to create master/slave with e.g keepalive, but how nginx backup will know about domains since all of them are registered on master, any suggestion ? thnx a lot!
Comment: @vladeli If you are using a cloud set up, one of the built in load balancers will work fine. alternatively Keepalived is a good idea. Just bear in mind that with Keepalived, you'll need to have both servers reside in the same subnet.
Comment: real problem is when i switch to backup nginx it will not work since all domains are registered for master nginx instance and i am afraid that this setup is not possible..
Comment: @vladeli - what do you mean 'the domains are registered for master' ? domains should just be pointing to an IP address, and that IP address can move. Like you said, keepalived is a good idea. You can 1-1 NAT an external ip to say, 10.0.0.1, and then float that IP between two Nginx instances using keepalived.
Comment: yes all domains point to one IP, is there possibility to automate this IP change with NAT 1-1 with floating or i must do it manually ?